src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2012 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(uschar *, BOOL, uschar **, BOOL, BOOL);
  17
  18 #ifdef STAND_ALONE
  19 #ifndef SUPPORT_CRYPTEQ
  20 #define SUPPORT_CRYPTEQ
  21 #endif
  22 #endif
  23
  24 #ifdef LOOKUP_LDAP
  25 #include "lookups/ldap.h"
  26 #endif
  27
  28 #ifdef SUPPORT_CRYPTEQ
  29 #ifdef CRYPT_H
  30 #include <crypt.h>
  31 #endif
  32 #ifndef HAVE_CRYPT16
  33 extern char* crypt16(char*, char*);
  34 #endif
  35 #endif
  36
  37 /* The handling of crypt16() is a mess. I will record below the analysis of the
  38 mess that was sent to me. We decided, however, to make changing this very low
  39 priority, because in practice people are moving away from the crypt()
  40 algorithms nowadays, so it doesn't seem worth it.
  41
  42 <quote>
  43 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  44 the first 8 characters of the password using a 20-round version of crypt
  45 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  46 or an empty block if the password is less than 9 characters, using a
  47 20-round version of crypt and the same salt as was used for the first
  48 block.  Charaters after the first 16 are ignored.  It always generates
  49 a 16-byte hash, which is expressed together with the salt as a string
  50 of 24 base 64 digits.  Here are some links to peruse:
  51
  52         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  53         http://seclists.org/bugtraq/1999/Mar/0076.html
  54
  55 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  56 and OSF/1.  This is the same as the standard crypt if given a password
  57 of 8 characters or less.  If given more, it first does the same as crypt
  58 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  59 using as salt the first two base 64 digits from the first hash block.
  60 If the password is more than 16 characters then it crypts the 17th to 24th
  61 characters using as salt the first two base 64 digits from the second hash
  62 block.  And so on: I've seen references to it cutting off the password at
  63 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  64
  65         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  66         http://seclists.org/bugtraq/1999/Mar/0109.html
  67         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  68              TET1_html/sec.c222.html#no_id_208
  69
  70 Exim has something it calls "crypt16".  It will either use a native
  71 crypt16 or its own implementation.  A native crypt16 will presumably
  72 be the one that I called "crypt16" above.  The internal "crypt16"
  73 function, however, is a two-block-maximum implementation of what I called
  74 "bigcrypt".  The documentation matches the internal code.
  75
  76 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  77 that crypt16 and bigcrypt were different things.
  78
  79 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  80 to whatever it is using under that name.  This unfortunately sets a
  81 precedent for using "{crypt16}" to identify two incompatible algorithms
  82 whose output can't be distinguished.  With "{crypt16}" thus rendered
  83 ambiguous, I suggest you deprecate it and invent two new identifiers
  84 for the two algorithms.
  85
  86 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  87 of the password separately means they can be cracked separately, so
  88 the double-length hash only doubles the cracking effort instead of
  89 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  90 bcrypt ({CRYPT}$2a$).
  91 </quote>
  92 */
  93
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"dlfunc",
 107   US"extract",
 108   US"filter",
 109   US"hash",
 110   US"hmac",
 111   US"if",
 112   US"length",
 113   US"lookup",
 114   US"map",
 115   US"nhash",
 116   US"perl",
 117   US"prvs",
 118   US"prvscheck",
 119   US"readfile",
 120   US"readsocket",
 121   US"reduce",
 122   US"run",
 123   US"sg",
 124   US"substr",
 125   US"tr" };
 126
 127 enum {
 128   EITEM_ACL,
 129   EITEM_DLFUNC,
 130   EITEM_EXTRACT,
 131   EITEM_FILTER,
 132   EITEM_HASH,
 133   EITEM_HMAC,
 134   EITEM_IF,
 135   EITEM_LENGTH,
 136   EITEM_LOOKUP,
 137   EITEM_MAP,
 138   EITEM_NHASH,
 139   EITEM_PERL,
 140   EITEM_PRVS,
 141   EITEM_PRVSCHECK,
 142   EITEM_READFILE,
 143   EITEM_READSOCK,
 144   EITEM_REDUCE,
 145   EITEM_RUN,
 146   EITEM_SG,
 147   EITEM_SUBSTR,
 148   EITEM_TR };
 149
 150 /* Tables of operator names, and corresponding switch numbers. The names must be
 151 in alphabetical order. There are two tables, because underscore is used in some
 152 cases to introduce arguments, whereas for other it is part of the name. This is
 153 an historical mis-design. */
 154
 155 static uschar *op_table_underscore[] = {
 156   US"from_utf8",
 157   US"local_part",
 158   US"quote_local_part",
 159   US"reverse_ip",
 160   US"time_eval",
 161   US"time_interval"};
 162
 163 enum {
 164   EOP_FROM_UTF8,
 165   EOP_LOCAL_PART,
 166   EOP_QUOTE_LOCAL_PART,
 167   EOP_REVERSE_IP,
 168   EOP_TIME_EVAL,
 169   EOP_TIME_INTERVAL };
 170
 171 static uschar *op_table_main[] = {
 172   US"address",
 173   US"addresses",
 174   US"base62",
 175   US"base62d",
 176   US"domain",
 177   US"escape",
 178   US"eval",
 179   US"eval10",
 180   US"expand",
 181   US"h",
 182   US"hash",
 183   US"hex2b64",
 184   US"l",
 185   US"lc",
 186   US"length",
 187   US"listcount",
 188   US"listnamed",
 189   US"mask",
 190   US"md5",
 191   US"nh",
 192   US"nhash",
 193   US"quote",
 194   US"randint",
 195   US"rfc2047",
 196   US"rfc2047d",
 197   US"rxquote",
 198   US"s",
 199   US"sha1",
 200   US"stat",
 201   US"str2b64",
 202   US"strlen",
 203   US"substr",
 204   US"uc" };
 205
 206 enum {
 207   EOP_ADDRESS =  sizeof(op_table_underscore)/sizeof(uschar *),
 208   EOP_ADDRESSES,
 209   EOP_BASE62,
 210   EOP_BASE62D,
 211   EOP_DOMAIN,
 212   EOP_ESCAPE,
 213   EOP_EVAL,
 214   EOP_EVAL10,
 215   EOP_EXPAND,
 216   EOP_H,
 217   EOP_HASH,
 218   EOP_HEX2B64,
 219   EOP_L,
 220   EOP_LC,
 221   EOP_LENGTH,
 222   EOP_LISTCOUNT,
 223   EOP_LISTNAMED,
 224   EOP_MASK,
 225   EOP_MD5,
 226   EOP_NH,
 227   EOP_NHASH,
 228   EOP_QUOTE,
 229   EOP_RANDINT,
 230   EOP_RFC2047,
 231   EOP_RFC2047D,
 232   EOP_RXQUOTE,
 233   EOP_S,
 234   EOP_SHA1,
 235   EOP_STAT,
 236   EOP_STR2B64,
 237   EOP_STRLEN,
 238   EOP_SUBSTR,
 239   EOP_UC };
 240
 241
 242 /* Table of condition names, and corresponding switch numbers. The names must
 243 be in alphabetical order. */
 244
 245 static uschar *cond_table[] = {
 246   US"<",
 247   US"<=",
 248   US"=",
 249   US"==",     /* Backward compatibility */
 250   US">",
 251   US">=",
 252   US"and",
 253   US"bool",
 254   US"bool_lax",
 255   US"crypteq",
 256   US"def",
 257   US"eq",
 258   US"eqi",
 259   US"exists",
 260   US"first_delivery",
 261   US"forall",
 262   US"forany",
 263   US"ge",
 264   US"gei",
 265   US"gt",
 266   US"gti",
 267   US"inlist",
 268   US"inlisti",
 269   US"isip",
 270   US"isip4",
 271   US"isip6",
 272   US"ldapauth",
 273   US"le",
 274   US"lei",
 275   US"lt",
 276   US"lti",
 277   US"match",
 278   US"match_address",
 279   US"match_domain",
 280   US"match_ip",
 281   US"match_local_part",
 282   US"or",
 283   US"pam",
 284   US"pwcheck",
 285   US"queue_running",
 286   US"radius",
 287   US"saslauthd"
 288 };
 289
 290 enum {
 291   ECOND_NUM_L,
 292   ECOND_NUM_LE,
 293   ECOND_NUM_E,
 294   ECOND_NUM_EE,
 295   ECOND_NUM_G,
 296   ECOND_NUM_GE,
 297   ECOND_AND,
 298   ECOND_BOOL,
 299   ECOND_BOOL_LAX,
 300   ECOND_CRYPTEQ,
 301   ECOND_DEF,
 302   ECOND_STR_EQ,
 303   ECOND_STR_EQI,
 304   ECOND_EXISTS,
 305   ECOND_FIRST_DELIVERY,
 306   ECOND_FORALL,
 307   ECOND_FORANY,
 308   ECOND_STR_GE,
 309   ECOND_STR_GEI,
 310   ECOND_STR_GT,
 311   ECOND_STR_GTI,
 312   ECOND_INLIST,
 313   ECOND_INLISTI,
 314   ECOND_ISIP,
 315   ECOND_ISIP4,
 316   ECOND_ISIP6,
 317   ECOND_LDAPAUTH,
 318   ECOND_STR_LE,
 319   ECOND_STR_LEI,
 320   ECOND_STR_LT,
 321   ECOND_STR_LTI,
 322   ECOND_MATCH,
 323   ECOND_MATCH_ADDRESS,
 324   ECOND_MATCH_DOMAIN,
 325   ECOND_MATCH_IP,
 326   ECOND_MATCH_LOCAL_PART,
 327   ECOND_OR,
 328   ECOND_PAM,
 329   ECOND_PWCHECK,
 330   ECOND_QUEUE_RUNNING,
 331   ECOND_RADIUS,
 332   ECOND_SASLAUTHD
 333 };
 334
 335
 336 /* Type for main variable table */
 337
 338 typedef struct {
 339   const char *name;
 340   int         type;
 341   void       *value;
 342 } var_entry;
 343
 344 /* Type for entries pointing to address/length pairs. Not currently
 345 in use. */
 346
 347 typedef struct {
 348   uschar **address;
 349   int  *length;
 350 } alblock;
 351
 352 /* Types of table entry */
 353
 354 enum {
 355   vtype_int,            /* value is address of int */
 356   vtype_filter_int,     /* ditto, but recognized only when filtering */
 357   vtype_ino,            /* value is address of ino_t (not always an int) */
 358   vtype_uid,            /* value is address of uid_t (not always an int) */
 359   vtype_gid,            /* value is address of gid_t (not always an int) */
 360   vtype_bool,           /* value is address of bool */
 361   vtype_stringptr,      /* value is address of pointer to string */
 362   vtype_msgbody,        /* as stringptr, but read when first required */
 363   vtype_msgbody_end,    /* ditto, the end of the message */
 364   vtype_msgheaders,     /* the message's headers, processed */
 365   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 366   vtype_localpart,      /* extract local part from string */
 367   vtype_domain,         /* extract domain from string */
 368   vtype_recipients,     /* extract recipients from recipients list */
 369                         /* (available only in system filters, ACLs, and */
 370                         /* local_scan()) */
 371   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 372   vtype_tode,           /* value not used; generate tod in epoch format */
 373   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 374   vtype_todf,           /* value not used; generate full tod */
 375   vtype_todl,           /* value not used; generate log tod */
 376   vtype_todlf,          /* value not used; generate log file datestamp tod */
 377   vtype_todzone,        /* value not used; generate time zone only */
 378   vtype_todzulu,        /* value not used; generate zulu tod */
 379   vtype_reply,          /* value not used; get reply from headers */
 380   vtype_pid,            /* value not used; result is pid */
 381   vtype_host_lookup,    /* value not used; get host name */
 382   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 383   vtype_pspace,         /* partition space; value is T/F for spool/log */
 384   vtype_pinodes         /* partition inodes; value is T/F for spool/log */
 385   #ifndef DISABLE_DKIM
 386   ,vtype_dkim           /* Lookup of value in DKIM signature */
 387   #endif
 388   };
 389
 390 /* This table must be kept in alphabetical order. */
 391
 392 static var_entry var_table[] = {
 393   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 394      they will be confused with user-creatable ACL variables. */
 395   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 396   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 397   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 398   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 399   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 400   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 401   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 402   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 403   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 404   { "acl_narg",            vtype_int,         &acl_narg },
 405   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 406   { "address_data",        vtype_stringptr,   &deliver_address_data },
 407   { "address_file",        vtype_stringptr,   &address_file },
 408   { "address_pipe",        vtype_stringptr,   &address_pipe },
 409   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 410   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 411   { "authentication_failed",vtype_int,        &authentication_failed },
 412 #ifdef WITH_CONTENT_SCAN
 413   { "av_failed",           vtype_int,         &av_failed },
 414 #endif
 415 #ifdef EXPERIMENTAL_BRIGHTMAIL
 416   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 417   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 418   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 419   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 420 #endif
 421   { "body_linecount",      vtype_int,         &body_linecount },
 422   { "body_zerocount",      vtype_int,         &body_zerocount },
 423   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 424   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 425   { "caller_gid",          vtype_gid,         &real_gid },
 426   { "caller_uid",          vtype_uid,         &real_uid },
 427   { "compile_date",        vtype_stringptr,   &version_date },
 428   { "compile_number",      vtype_stringptr,   &version_cnumber },
 429   { "csa_status",          vtype_stringptr,   &csa_status },
 430 #ifdef EXPERIMENTAL_DCC
 431   { "dcc_header",          vtype_stringptr,   &dcc_header },
 432   { "dcc_result",          vtype_stringptr,   &dcc_result },
 433 #endif
 434 #ifdef WITH_OLD_DEMIME
 435   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 436   { "demime_reason",       vtype_stringptr,   &demime_reason },
 437 #endif
 438 #ifndef DISABLE_DKIM
 439   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 440   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 441   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 442   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 443   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 444   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 445   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 446   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 447   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 448   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 449   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 450   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 451   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 452   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 453   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 454   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 455   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 456   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 457   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 458   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 459 #endif
 460   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 461   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 462   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 463   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 464   { "domain",              vtype_stringptr,   &deliver_domain },
 465   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 466   { "exim_gid",            vtype_gid,         &exim_gid },
 467   { "exim_path",           vtype_stringptr,   &exim_path },
 468   { "exim_uid",            vtype_uid,         &exim_uid },
 469 #ifdef WITH_OLD_DEMIME
 470   { "found_extension",     vtype_stringptr,   &found_extension },
 471 #endif
 472   { "home",                vtype_stringptr,   &deliver_home },
 473   { "host",                vtype_stringptr,   &deliver_host },
 474   { "host_address",        vtype_stringptr,   &deliver_host_address },
 475   { "host_data",           vtype_stringptr,   &host_data },
 476   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 477   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 478   { "inode",               vtype_ino,         &deliver_inode },
 479   { "interface_address",   vtype_stringptr,   &interface_address },
 480   { "interface_port",      vtype_int,         &interface_port },
 481   { "item",                vtype_stringptr,   &iterate_item },
 482   #ifdef LOOKUP_LDAP
 483   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 484   #endif
 485   { "load_average",        vtype_load_avg,    NULL },
 486   { "local_part",          vtype_stringptr,   &deliver_localpart },
 487   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 488   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 489   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 490   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 491   { "local_user_gid",      vtype_gid,         &local_user_gid },
 492   { "local_user_uid",      vtype_uid,         &local_user_uid },
 493   { "localhost_number",    vtype_int,         &host_number },
 494   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 495   { "log_space",           vtype_pspace,      (void *)FALSE },
 496   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 497 #ifdef WITH_CONTENT_SCAN
 498   { "malware_name",        vtype_stringptr,   &malware_name },
 499 #endif
 500   { "max_received_linelength", vtype_int,     &max_received_linelength },
 501   { "message_age",         vtype_int,         &message_age },
 502   { "message_body",        vtype_msgbody,     &message_body },
 503   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 504   { "message_body_size",   vtype_int,         &message_body_size },
 505   { "message_exim_id",     vtype_stringptr,   &message_id },
 506   { "message_headers",     vtype_msgheaders,  NULL },
 507   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 508   { "message_id",          vtype_stringptr,   &message_id },
 509   { "message_linecount",   vtype_int,         &message_linecount },
 510   { "message_size",        vtype_int,         &message_size },
 511 #ifdef WITH_CONTENT_SCAN
 512   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 513   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 514   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 515   { "mime_charset",        vtype_stringptr,   &mime_charset },
 516   { "mime_content_description", vtype_stringptr, &mime_content_description },
 517   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 518   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 519   { "mime_content_size",   vtype_int,         &mime_content_size },
 520   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 521   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 522   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 523   { "mime_filename",       vtype_stringptr,   &mime_filename },
 524   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 525   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 526   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 527   { "mime_part_count",     vtype_int,         &mime_part_count },
 528 #endif
 529   { "n0",                  vtype_filter_int,  &filter_n[0] },
 530   { "n1",                  vtype_filter_int,  &filter_n[1] },
 531   { "n2",                  vtype_filter_int,  &filter_n[2] },
 532   { "n3",                  vtype_filter_int,  &filter_n[3] },
 533   { "n4",                  vtype_filter_int,  &filter_n[4] },
 534   { "n5",                  vtype_filter_int,  &filter_n[5] },
 535   { "n6",                  vtype_filter_int,  &filter_n[6] },
 536   { "n7",                  vtype_filter_int,  &filter_n[7] },
 537   { "n8",                  vtype_filter_int,  &filter_n[8] },
 538   { "n9",                  vtype_filter_int,  &filter_n[9] },
 539   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 540   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 541   { "originator_gid",      vtype_gid,         &originator_gid },
 542   { "originator_uid",      vtype_uid,         &originator_uid },
 543   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 544   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 545   { "pid",                 vtype_pid,         NULL },
 546   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 547   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 548   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 549   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 550   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 551   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 552   { "rcpt_count",          vtype_int,         &rcpt_count },
 553   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 554   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 555   { "received_count",      vtype_int,         &received_count },
 556   { "received_for",        vtype_stringptr,   &received_for },
 557   { "received_ip_address", vtype_stringptr,   &interface_address },
 558   { "received_port",       vtype_int,         &interface_port },
 559   { "received_protocol",   vtype_stringptr,   &received_protocol },
 560   { "received_time",       vtype_int,         &received_time },
 561   { "recipient_data",      vtype_stringptr,   &recipient_data },
 562   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 563   { "recipients",          vtype_recipients,  NULL },
 564   { "recipients_count",    vtype_int,         &recipients_count },
 565 #ifdef WITH_CONTENT_SCAN
 566   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 567 #endif
 568   { "reply_address",       vtype_reply,       NULL },
 569   { "return_path",         vtype_stringptr,   &return_path },
 570   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 571   { "runrc",               vtype_int,         &runrc },
 572   { "self_hostname",       vtype_stringptr,   &self_hostname },
 573   { "sender_address",      vtype_stringptr,   &sender_address },
 574   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 575   { "sender_address_domain", vtype_domain,    &sender_address },
 576   { "sender_address_local_part", vtype_localpart, &sender_address },
 577   { "sender_data",         vtype_stringptr,   &sender_data },
 578   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 579   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 580   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 581   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 582   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 583   { "sender_host_name",    vtype_host_lookup, NULL },
 584   { "sender_host_port",    vtype_int,         &sender_host_port },
 585   { "sender_ident",        vtype_stringptr,   &sender_ident },
 586   { "sender_rate",         vtype_stringptr,   &sender_rate },
 587   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 588   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 589   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 590   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 591   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 592   { "sending_port",        vtype_int,         &sending_port },
 593   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 594   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 595   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 596   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 597   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 598   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 599   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 600   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 601   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 602   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 603   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 604   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 605   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 606   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 607   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 608 #ifdef WITH_CONTENT_SCAN
 609   { "spam_bar",            vtype_stringptr,   &spam_bar },
 610   { "spam_report",         vtype_stringptr,   &spam_report },
 611   { "spam_score",          vtype_stringptr,   &spam_score },
 612   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 613 #endif
 614 #ifdef EXPERIMENTAL_SPF
 615   { "spf_guess",           vtype_stringptr,   &spf_guess },
 616   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 617   { "spf_received",        vtype_stringptr,   &spf_received },
 618   { "spf_result",          vtype_stringptr,   &spf_result },
 619   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 620 #endif
 621   { "spool_directory",     vtype_stringptr,   &spool_directory },
 622   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 623   { "spool_space",         vtype_pspace,      (void *)TRUE },
 624 #ifdef EXPERIMENTAL_SRS
 625   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 626   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 627   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 628   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 629   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 630   { "srs_status",          vtype_stringptr,   &srs_status },
 631 #endif
 632   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 633
 634   /* The non-(in,out) variables are now deprecated */
 635   { "tls_bits",            vtype_int,         &tls_in.bits },
 636   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 637   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 638
 639   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 640   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 641   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 642   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 643 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 644   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 645 #endif
 646   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 647   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 648   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 649   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 650 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 651   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 652 #endif
 653
 654   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 655 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 656   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 657 #endif
 658
 659   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 660   { "tod_epoch",           vtype_tode,        NULL },
 661   { "tod_epoch_l",         vtype_todel,       NULL },
 662   { "tod_full",            vtype_todf,        NULL },
 663   { "tod_log",             vtype_todl,        NULL },
 664   { "tod_logfile",         vtype_todlf,       NULL },
 665   { "tod_zone",            vtype_todzone,     NULL },
 666   { "tod_zulu",            vtype_todzulu,     NULL },
 667   { "value",               vtype_stringptr,   &lookup_value },
 668   { "version_number",      vtype_stringptr,   &version_string },
 669   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 670   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 671   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 672   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 673   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 674   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 675 };
 676
 677 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
 678 static uschar var_buffer[256];
 679 static BOOL malformed_header;
 680
 681 /* For textual hashes */
 682
 683 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 684                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 685                                "0123456789";
 686
 687 enum { HMAC_MD5, HMAC_SHA1 };
 688
 689 /* For numeric hashes */
 690
 691 static unsigned int prime[] = {
 692   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 693  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 694  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 695
 696 /* For printing modes in symbolic form */
 697
 698 static uschar *mtable_normal[] =
 699   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 700
 701 static uschar *mtable_setid[] =
 702   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 703
 704 static uschar *mtable_sticky[] =
 705   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 706
 707
 708
 709 /*************************************************
 710 *           Tables for UTF-8 support             *
 711 *************************************************/
 712
 713 /* Table of the number of extra characters, indexed by the first character
 714 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 715 0x3d. */
 716
 717 static uschar utf8_table1[] = {
 718   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 719   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 720   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 721   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 722
 723 /* These are the masks for the data bits in the first byte of a character,
 724 indexed by the number of additional bytes. */
 725
 726 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 727
 728 /* Get the next UTF-8 character, advancing the pointer. */
 729
 730 #define GETUTF8INC(c, ptr) \
 731   c = *ptr++; \
 732   if ((c & 0xc0) == 0xc0) \
 733     { \
 734     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 735     int s = 6*a; \
 736     c = (c & utf8_table2[a]) << s; \
 737     while (a-- > 0) \
 738       { \
 739       s -= 6; \
 740       c |= (*ptr++ & 0x3f) << s; \
 741       } \
 742     }
 743
 744
 745 /*************************************************
 746 *           Binary chop search on a table        *
 747 *************************************************/
 748
 749 /* This is used for matching expansion items and operators.
 750
 751 Arguments:
 752   name        the name that is being sought
 753   table       the table to search
 754   table_size  the number of items in the table
 755
 756 Returns:      the offset in the table, or -1
 757 */
 758
 759 static int
 760 chop_match(uschar *name, uschar **table, int table_size)
 761 {
 762 uschar **bot = table;
 763 uschar **top = table + table_size;
 764
 765 while (top > bot)
 766   {
 767   uschar **mid = bot + (top - bot)/2;
 768   int c = Ustrcmp(name, *mid);
 769   if (c == 0) return mid - table;
 770   if (c > 0) bot = mid + 1; else top = mid;
 771   }
 772
 773 return -1;
 774 }
 775
 776
 777
 778 /*************************************************
 779 *          Check a condition string              *
 780 *************************************************/
 781
 782 /* This function is called to expand a string, and test the result for a "true"
 783 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 784 forced fail or lookup defer. All store used by the function can be released on
 785 exit.
 786
 787 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 788
 789 Arguments:
 790   condition     the condition string
 791   m1            text to be incorporated in panic error
 792   m2            ditto
 793
 794 Returns:        TRUE if condition is met, FALSE if not
 795 */
 796
 797 BOOL
 798 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 799 {
 800 int rc;
 801 void *reset_point = store_get(0);
 802 uschar *ss = expand_string(condition);
 803 if (ss == NULL)
 804   {
 805   if (!expand_string_forcedfail && !search_find_defer)
 806     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 807       "for %s %s: %s", condition, m1, m2, expand_string_message);
 808   return FALSE;
 809   }
 810 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 811   strcmpic(ss, US"false") != 0;
 812 store_reset(reset_point);
 813 return rc;
 814 }
 815
 816
 817
 818
 819 /*************************************************
 820 *        Pseudo-random number generation         *
 821 *************************************************/
 822
 823 /* Pseudo-random number generation.  The result is not "expected" to be
 824 cryptographically strong but not so weak that someone will shoot themselves
 825 in the foot using it as a nonce in some email header scheme or whatever
 826 weirdness they'll twist this into.  The result should ideally handle fork().
 827
 828 However, if we're stuck unable to provide this, then we'll fall back to
 829 appallingly bad randomness.
 830
 831 If SUPPORT_TLS is defined then this will not be used except as an emergency
 832 fallback.
 833
 834 Arguments:
 835   max       range maximum
 836 Returns     a random number in range [0, max-1]
 837 */
 838
 839 #ifdef SUPPORT_TLS
 840 # define vaguely_random_number vaguely_random_number_fallback
 841 #endif
 842 int
 843 vaguely_random_number(int max)
 844 {
 845 #ifdef SUPPORT_TLS
 846 # undef vaguely_random_number
 847 #endif
 848   static pid_t pid = 0;
 849   pid_t p2;
 850 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 851   struct timeval tv;
 852 #endif
 853
 854   p2 = getpid();
 855   if (p2 != pid)
 856     {
 857     if (pid != 0)
 858       {
 859
 860 #ifdef HAVE_ARC4RANDOM
 861       /* cryptographically strong randomness, common on *BSD platforms, not
 862       so much elsewhere.  Alas. */
 863       arc4random_stir();
 864 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 865 #ifdef HAVE_SRANDOMDEV
 866       /* uses random(4) for seeding */
 867       srandomdev();
 868 #else
 869       gettimeofday(&tv, NULL);
 870       srandom(tv.tv_sec | tv.tv_usec | getpid());
 871 #endif
 872 #else
 873       /* Poor randomness and no seeding here */
 874 #endif
 875
 876       }
 877     pid = p2;
 878     }
 879
 880 #ifdef HAVE_ARC4RANDOM
 881   return arc4random() % max;
 882 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 883   return random() % max;
 884 #else
 885   /* This one returns a 16-bit number, definitely not crypto-strong */
 886   return random_number(max);
 887 #endif
 888 }
 889
 890
 891
 892
 893 /*************************************************
 894 *             Pick out a name from a string      *
 895 *************************************************/
 896
 897 /* If the name is too long, it is silently truncated.
 898
 899 Arguments:
 900   name      points to a buffer into which to put the name
 901   max       is the length of the buffer
 902   s         points to the first alphabetic character of the name
 903   extras    chars other than alphanumerics to permit
 904
 905 Returns:    pointer to the first character after the name
 906
 907 Note: The test for *s != 0 in the while loop is necessary because
 908 Ustrchr() yields non-NULL if the character is zero (which is not something
 909 I expected). */
 910
 911 static uschar *
 912 read_name(uschar *name, int max, uschar *s, uschar *extras)
 913 {
 914 int ptr = 0;
 915 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 916   {
 917   if (ptr < max-1) name[ptr++] = *s;
 918   s++;
 919   }
 920 name[ptr] = 0;
 921 return s;
 922 }
 923
 924
 925
 926 /*************************************************
 927 *     Pick out the rest of a header name         *
 928 *************************************************/
 929
 930 /* A variable name starting $header_ (or just $h_ for those who like
 931 abbreviations) might not be the complete header name because headers can
 932 contain any printing characters in their names, except ':'. This function is
 933 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 934 on the end, if the name was terminated by white space.
 935
 936 Arguments:
 937   name      points to a buffer in which the name read so far exists
 938   max       is the length of the buffer
 939   s         points to the first character after the name so far, i.e. the
 940             first non-alphameric character after $header_xxxxx
 941
 942 Returns:    a pointer to the first character after the header name
 943 */
 944
 945 static uschar *
 946 read_header_name(uschar *name, int max, uschar *s)
 947 {
 948 int prelen = Ustrchr(name, '_') - name + 1;
 949 int ptr = Ustrlen(name) - prelen;
 950 if (ptr > 0) memmove(name, name+prelen, ptr);
 951 while (mac_isgraph(*s) && *s != ':')
 952   {
 953   if (ptr < max-1) name[ptr++] = *s;
 954   s++;
 955   }
 956 if (*s == ':') s++;
 957 name[ptr++] = ':';
 958 name[ptr] = 0;
 959 return s;
 960 }
 961
 962
 963
 964 /*************************************************
 965 *           Pick out a number from a string      *
 966 *************************************************/
 967
 968 /* Arguments:
 969   n     points to an integer into which to put the number
 970   s     points to the first digit of the number
 971
 972 Returns:  a pointer to the character after the last digit
 973 */
 974
 975 static uschar *
 976 read_number(int *n, uschar *s)
 977 {
 978 *n = 0;
 979 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
 980 return s;
 981 }
 982
 983
 984
 985 /*************************************************
 986 *        Extract keyed subfield from a string    *
 987 *************************************************/
 988
 989 /* The yield is in dynamic store; NULL means that the key was not found.
 990
 991 Arguments:
 992   key       points to the name of the key
 993   s         points to the string from which to extract the subfield
 994
 995 Returns:    NULL if the subfield was not found, or
 996             a pointer to the subfield's data
 997 */
 998
 999 static uschar *
1000 expand_getkeyed(uschar *key, uschar *s)
1001 {
1002 int length = Ustrlen(key);
1003 while (isspace(*s)) s++;
1004
1005 /* Loop to search for the key */
1006
1007 while (*s != 0)
1008   {
1009   int dkeylength;
1010   uschar *data;
1011   uschar *dkey = s;
1012
1013   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1014   dkeylength = s - dkey;
1015   while (isspace(*s)) s++;
1016   if (*s == '=') while (isspace((*(++s))));
1017
1018   data = string_dequote(&s);
1019   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1020     return data;
1021
1022   while (isspace(*s)) s++;
1023   }
1024
1025 return NULL;
1026 }
1027
1028
1029
1030
1031 /*************************************************
1032 *   Extract numbered subfield from string        *
1033 *************************************************/
1034
1035 /* Extracts a numbered field from a string that is divided by tokens - for
1036 example a line from /etc/passwd is divided by colon characters.  First field is
1037 numbered one.  Negative arguments count from the right. Zero returns the whole
1038 string. Returns NULL if there are insufficient tokens in the string
1039
1040 ***WARNING***
1041 Modifies final argument - this is a dynamically generated string, so that's OK.
1042
1043 Arguments:
1044   field       number of field to be extracted,
1045                 first field = 1, whole string = 0, last field = -1
1046   separators  characters that are used to break string into tokens
1047   s           points to the string from which to extract the subfield
1048
1049 Returns:      NULL if the field was not found,
1050               a pointer to the field's data inside s (modified to add 0)
1051 */
1052
1053 static uschar *
1054 expand_gettokened (int field, uschar *separators, uschar *s)
1055 {
1056 int sep = 1;
1057 int count;
1058 uschar *ss = s;
1059 uschar *fieldtext = NULL;
1060
1061 if (field == 0) return s;
1062
1063 /* Break the line up into fields in place; for field > 0 we stop when we have
1064 done the number of fields we want. For field < 0 we continue till the end of
1065 the string, counting the number of fields. */
1066
1067 count = (field > 0)? field : INT_MAX;
1068
1069 while (count-- > 0)
1070   {
1071   size_t len;
1072
1073   /* Previous field was the last one in the string. For a positive field
1074   number, this means there are not enough fields. For a negative field number,
1075   check that there are enough, and scan back to find the one that is wanted. */
1076
1077   if (sep == 0)
1078     {
1079     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1080     if ((-field) == (INT_MAX - count - 1)) return s;
1081     while (field++ < 0)
1082       {
1083       ss--;
1084       while (ss[-1] != 0) ss--;
1085       }
1086     fieldtext = ss;
1087     break;
1088     }
1089
1090   /* Previous field was not last in the string; save its start and put a
1091   zero at its end. */
1092
1093   fieldtext = ss;
1094   len = Ustrcspn(ss, separators);
1095   sep = ss[len];
1096   ss[len] = 0;
1097   ss += len + 1;
1098   }
1099
1100 return fieldtext;
1101 }
1102
1103
1104
1105 /*************************************************
1106 *        Extract a substring from a string       *
1107 *************************************************/
1108
1109 /* Perform the ${substr or ${length expansion operations.
1110
1111 Arguments:
1112   subject     the input string
1113   value1      the offset from the start of the input string to the start of
1114                 the output string; if negative, count from the right.
1115   value2      the length of the output string, or negative (-1) for unset
1116                 if value1 is positive, unset means "all after"
1117                 if value1 is negative, unset means "all before"
1118   len         set to the length of the returned string
1119
1120 Returns:      pointer to the output string, or NULL if there is an error
1121 */
1122
1123 static uschar *
1124 extract_substr(uschar *subject, int value1, int value2, int *len)
1125 {
1126 int sublen = Ustrlen(subject);
1127
1128 if (value1 < 0)    /* count from right */
1129   {
1130   value1 += sublen;
1131
1132   /* If the position is before the start, skip to the start, and adjust the
1133   length. If the length ends up negative, the substring is null because nothing
1134   can precede. This falls out naturally when the length is unset, meaning "all
1135   to the left". */
1136
1137   if (value1 < 0)
1138     {
1139     value2 += value1;
1140     if (value2 < 0) value2 = 0;
1141     value1 = 0;
1142     }
1143
1144   /* Otherwise an unset length => characters before value1 */
1145
1146   else if (value2 < 0)
1147     {
1148     value2 = value1;
1149     value1 = 0;
1150     }
1151   }
1152
1153 /* For a non-negative offset, if the starting position is past the end of the
1154 string, the result will be the null string. Otherwise, an unset length means
1155 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1156
1157 else
1158   {
1159   if (value1 > sublen)
1160     {
1161     value1 = sublen;
1162     value2 = 0;
1163     }
1164   else if (value2 < 0) value2 = sublen;
1165   }
1166
1167 /* Cut the length down to the maximum possible for the offset value, and get
1168 the required characters. */
1169
1170 if (value1 + value2 > sublen) value2 = sublen - value1;
1171 *len = value2;
1172 return subject + value1;
1173 }
1174
1175
1176
1177
1178 /*************************************************
1179 *            Old-style hash of a string          *
1180 *************************************************/
1181
1182 /* Perform the ${hash expansion operation.
1183
1184 Arguments:
1185   subject     the input string (an expanded substring)
1186   value1      the length of the output string; if greater or equal to the
1187                 length of the input string, the input string is returned
1188   value2      the number of hash characters to use, or 26 if negative
1189   len         set to the length of the returned string
1190
1191 Returns:      pointer to the output string, or NULL if there is an error
1192 */
1193
1194 static uschar *
1195 compute_hash(uschar *subject, int value1, int value2, int *len)
1196 {
1197 int sublen = Ustrlen(subject);
1198
1199 if (value2 < 0) value2 = 26;
1200 else if (value2 > Ustrlen(hashcodes))
1201   {
1202   expand_string_message =
1203     string_sprintf("hash count \"%d\" too big", value2);
1204   return NULL;
1205   }
1206
1207 /* Calculate the hash text. We know it is shorter than the original string, so
1208 can safely place it in subject[] (we know that subject is always itself an
1209 expanded substring). */
1210
1211 if (value1 < sublen)
1212   {
1213   int c;
1214   int i = 0;
1215   int j = value1;
1216   while ((c = (subject[j])) != 0)
1217     {
1218     int shift = (c + j++) & 7;
1219     subject[i] ^= (c << shift) | (c >> (8-shift));
1220     if (++i >= value1) i = 0;
1221     }
1222   for (i = 0; i < value1; i++)
1223     subject[i] = hashcodes[(subject[i]) % value2];
1224   }
1225 else value1 = sublen;
1226
1227 *len = value1;
1228 return subject;
1229 }
1230
1231
1232
1233
1234 /*************************************************
1235 *             Numeric hash of a string           *
1236 *************************************************/
1237
1238 /* Perform the ${nhash expansion operation. The first characters of the
1239 string are treated as most important, and get the highest prime numbers.
1240
1241 Arguments:
1242   subject     the input string
1243   value1      the maximum value of the first part of the result
1244   value2      the maximum value of the second part of the result,
1245                 or negative to produce only a one-part result
1246   len         set to the length of the returned string
1247
1248 Returns:  pointer to the output string, or NULL if there is an error.
1249 */
1250
1251 static uschar *
1252 compute_nhash (uschar *subject, int value1, int value2, int *len)
1253 {
1254 uschar *s = subject;
1255 int i = 0;
1256 unsigned long int total = 0; /* no overflow */
1257
1258 while (*s != 0)
1259   {
1260   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1261   total += prime[i--] * (unsigned int)(*s++);
1262   }
1263
1264 /* If value2 is unset, just compute one number */
1265
1266 if (value2 < 0)
1267   {
1268   s = string_sprintf("%d", total % value1);
1269   }
1270
1271 /* Otherwise do a div/mod hash */
1272
1273 else
1274   {
1275   total = total % (value1 * value2);
1276   s = string_sprintf("%d/%d", total/value2, total % value2);
1277   }
1278
1279 *len = Ustrlen(s);
1280 return s;
1281 }
1282
1283
1284
1285
1286
1287 /*************************************************
1288 *     Find the value of a header or headers      *
1289 *************************************************/
1290
1291 /* Multiple instances of the same header get concatenated, and this function
1292 can also return a concatenation of all the header lines. When concatenating
1293 specific headers that contain lists of addresses, a comma is inserted between
1294 them. Otherwise we use a straight concatenation. Because some messages can have
1295 pathologically large number of lines, there is a limit on the length that is
1296 returned. Also, to avoid massive store use which would result from using
1297 string_cat() as it copies and extends strings, we do a preliminary pass to find
1298 out exactly how much store will be needed. On "normal" messages this will be
1299 pretty trivial.
1300
1301 Arguments:
1302   name          the name of the header, without the leading $header_ or $h_,
1303                 or NULL if a concatenation of all headers is required
1304   exists_only   TRUE if called from a def: test; don't need to build a string;
1305                 just return a string that is not "" and not "0" if the header
1306                 exists
1307   newsize       return the size of memory block that was obtained; may be NULL
1308                 if exists_only is TRUE
1309   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1310                 other than concatenating, will be done on the header. Also used
1311                 for $message_headers_raw.
1312   charset       name of charset to translate MIME words to; used only if
1313                 want_raw is false; if NULL, no translation is done (this is
1314                 used for $bh_ and $bheader_)
1315
1316 Returns:        NULL if the header does not exist, else a pointer to a new
1317                 store block
1318 */
1319
1320 static uschar *
1321 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1322   uschar *charset)
1323 {
1324 BOOL found = name == NULL;
1325 int comma = 0;
1326 int len = found? 0 : Ustrlen(name);
1327 int i;
1328 uschar *yield = NULL;
1329 uschar *ptr = NULL;
1330
1331 /* Loop for two passes - saves code repetition */
1332
1333 for (i = 0; i < 2; i++)
1334   {
1335   int size = 0;
1336   header_line *h;
1337
1338   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1339     {
1340     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1341       {
1342       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1343         {
1344         int ilen;
1345         uschar *t;
1346
1347         if (exists_only) return US"1";      /* don't need actual string */
1348         found = TRUE;
1349         t = h->text + len;                  /* text to insert */
1350         if (!want_raw)                      /* unless wanted raw, */
1351           while (isspace(*t)) t++;          /* remove leading white space */
1352         ilen = h->slen - (t - h->text);     /* length to insert */
1353
1354         /* Unless wanted raw, remove trailing whitespace, including the
1355         newline. */
1356
1357         if (!want_raw)
1358           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1359
1360         /* Set comma = 1 if handling a single header and it's one of those
1361         that contains an address list, except when asked for raw headers. Only
1362         need to do this once. */
1363
1364         if (!want_raw && name != NULL && comma == 0 &&
1365             Ustrchr("BCFRST", h->type) != NULL)
1366           comma = 1;
1367
1368         /* First pass - compute total store needed; second pass - compute
1369         total store used, including this header. */
1370
1371         size += ilen + comma + 1;  /* +1 for the newline */
1372
1373         /* Second pass - concatentate the data, up to a maximum. Note that
1374         the loop stops when size hits the limit. */
1375
1376         if (i != 0)
1377           {
1378           if (size > header_insert_maxlen)
1379             {
1380             ilen -= size - header_insert_maxlen - 1;
1381             comma = 0;
1382             }
1383           Ustrncpy(ptr, t, ilen);
1384           ptr += ilen;
1385
1386           /* For a non-raw header, put in the comma if needed, then add
1387           back the newline we removed above, provided there was some text in
1388           the header. */
1389
1390           if (!want_raw && ilen > 0)
1391             {
1392             if (comma != 0) *ptr++ = ',';
1393             *ptr++ = '\n';
1394             }
1395           }
1396         }
1397       }
1398     }
1399
1400   /* At end of first pass, return NULL if no header found. Then truncate size
1401   if necessary, and get the buffer to hold the data, returning the buffer size.
1402   */
1403
1404   if (i == 0)
1405     {
1406     if (!found) return NULL;
1407     if (size > header_insert_maxlen) size = header_insert_maxlen;
1408     *newsize = size + 1;
1409     ptr = yield = store_get(*newsize);
1410     }
1411   }
1412
1413 /* That's all we do for raw header expansion. */
1414
1415 if (want_raw)
1416   {
1417   *ptr = 0;
1418   }
1419
1420 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1421 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1422 function can return an error with decoded data if the charset translation
1423 fails. If decoding fails, it returns NULL. */
1424
1425 else
1426   {
1427   uschar *decoded, *error;
1428   if (ptr > yield && ptr[-1] == '\n') ptr--;
1429   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1430   *ptr = 0;
1431   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1432     newsize, &error);
1433   if (error != NULL)
1434     {
1435     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1436       "    input was: %s\n", error, yield);
1437     }
1438   if (decoded != NULL) yield = decoded;
1439   }
1440
1441 return yield;
1442 }
1443
1444
1445
1446
1447 /*************************************************
1448 *               Find value of a variable         *
1449 *************************************************/
1450
1451 /* The table of variables is kept in alphabetic order, so we can search it
1452 using a binary chop. The "choplen" variable is nothing to do with the binary
1453 chop.
1454
1455 Arguments:
1456   name          the name of the variable being sought
1457   exists_only   TRUE if this is a def: test; passed on to find_header()
1458   skipping      TRUE => skip any processing evaluation; this is not the same as
1459                   exists_only because def: may test for values that are first
1460                   evaluated here
1461   newsize       pointer to an int which is initially zero; if the answer is in
1462                 a new memory buffer, *newsize is set to its size
1463
1464 Returns:        NULL if the variable does not exist, or
1465                 a pointer to the variable's contents, or
1466                 something non-NULL if exists_only is TRUE
1467 */
1468
1469 static uschar *
1470 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1471 {
1472 int first = 0;
1473 int last = var_table_size;
1474
1475 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1476 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1477 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1478 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1479 (this gave backwards compatibility at the changeover). There may be built-in
1480 variables whose names start acl_ but they should never start in this way. This
1481 slightly messy specification is a consequence of the history, needless to say.
1482
1483 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1484 set, in which case give an error. */
1485
1486 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1487      !isalpha(name[5]))
1488   {
1489   tree_node *node =
1490     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1491   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1492   }
1493
1494 /* Handle $auth<n> variables. */
1495
1496 if (Ustrncmp(name, "auth", 4) == 0)
1497   {
1498   uschar *endptr;
1499   int n = Ustrtoul(name + 4, &endptr, 10);
1500   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1501     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1502   }
1503
1504 /* For all other variables, search the table */
1505
1506 while (last > first)
1507   {
1508   uschar *s, *domain;
1509   uschar **ss;
1510   int middle = (first + last)/2;
1511   int c = Ustrcmp(name, var_table[middle].name);
1512
1513   if (c > 0) { first = middle + 1; continue; }
1514   if (c < 0) { last = middle; continue; }
1515
1516   /* Found an existing variable. If in skipping state, the value isn't needed,
1517   and we want to avoid processing (such as looking up the host name). */
1518
1519   if (skipping) return US"";
1520
1521   switch (var_table[middle].type)
1522     {
1523     case vtype_filter_int:
1524     if (!filter_running) return NULL;
1525     /* Fall through */
1526     /* VVVVVVVVVVVV */
1527     case vtype_int:
1528     sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1529     return var_buffer;
1530
1531     case vtype_ino:
1532     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1533     return var_buffer;
1534
1535     case vtype_gid:
1536     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1537     return var_buffer;
1538
1539     case vtype_uid:
1540     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1541     return var_buffer;
1542
1543     case vtype_bool:
1544     sprintf(CS var_buffer, "%s", *(BOOL *)(var_table[middle].value) ? "yes" : "no"); /* bool */
1545     return var_buffer;
1546
1547     case vtype_stringptr:                      /* Pointer to string */
1548     s = *((uschar **)(var_table[middle].value));
1549     return (s == NULL)? US"" : s;
1550
1551     case vtype_pid:
1552     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1553     return var_buffer;
1554
1555     case vtype_load_avg:
1556     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1557     return var_buffer;
1558
1559     case vtype_host_lookup:                    /* Lookup if not done so */
1560     if (sender_host_name == NULL && sender_host_address != NULL &&
1561         !host_lookup_failed && host_name_lookup() == OK)
1562       host_build_sender_fullhost();
1563     return (sender_host_name == NULL)? US"" : sender_host_name;
1564
1565     case vtype_localpart:                      /* Get local part from address */
1566     s = *((uschar **)(var_table[middle].value));
1567     if (s == NULL) return US"";
1568     domain = Ustrrchr(s, '@');
1569     if (domain == NULL) return s;
1570     if (domain - s > sizeof(var_buffer) - 1)
1571       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1572           " in string expansion", sizeof(var_buffer));
1573     Ustrncpy(var_buffer, s, domain - s);
1574     var_buffer[domain - s] = 0;
1575     return var_buffer;
1576
1577     case vtype_domain:                         /* Get domain from address */
1578     s = *((uschar **)(var_table[middle].value));
1579     if (s == NULL) return US"";
1580     domain = Ustrrchr(s, '@');
1581     return (domain == NULL)? US"" : domain + 1;
1582
1583     case vtype_msgheaders:
1584     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1585
1586     case vtype_msgheaders_raw:
1587     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1588
1589     case vtype_msgbody:                        /* Pointer to msgbody string */
1590     case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1591     ss = (uschar **)(var_table[middle].value);
1592     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1593       {
1594       uschar *body;
1595       off_t start_offset = SPOOL_DATA_START_OFFSET;
1596       int len = message_body_visible;
1597       if (len > message_size) len = message_size;
1598       *ss = body = store_malloc(len+1);
1599       body[0] = 0;
1600       if (var_table[middle].type == vtype_msgbody_end)
1601         {
1602         struct stat statbuf;
1603         if (fstat(deliver_datafile, &statbuf) == 0)
1604           {
1605           start_offset = statbuf.st_size - len;
1606           if (start_offset < SPOOL_DATA_START_OFFSET)
1607             start_offset = SPOOL_DATA_START_OFFSET;
1608           }
1609         }
1610       lseek(deliver_datafile, start_offset, SEEK_SET);
1611       len = read(deliver_datafile, body, len);
1612       if (len > 0)
1613         {
1614         body[len] = 0;
1615         if (message_body_newlines)   /* Separate loops for efficiency */
1616           {
1617           while (len > 0)
1618             { if (body[--len] == 0) body[len] = ' '; }
1619           }
1620         else
1621           {
1622           while (len > 0)
1623             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1624           }
1625         }
1626       }
1627     return (*ss == NULL)? US"" : *ss;
1628
1629     case vtype_todbsdin:                       /* BSD inbox time of day */
1630     return tod_stamp(tod_bsdin);
1631
1632     case vtype_tode:                           /* Unix epoch time of day */
1633     return tod_stamp(tod_epoch);
1634
1635     case vtype_todel:                          /* Unix epoch/usec time of day */
1636     return tod_stamp(tod_epoch_l);
1637
1638     case vtype_todf:                           /* Full time of day */
1639     return tod_stamp(tod_full);
1640
1641     case vtype_todl:                           /* Log format time of day */
1642     return tod_stamp(tod_log_bare);            /* (without timezone) */
1643
1644     case vtype_todzone:                        /* Time zone offset only */
1645     return tod_stamp(tod_zone);
1646
1647     case vtype_todzulu:                        /* Zulu time */
1648     return tod_stamp(tod_zulu);
1649
1650     case vtype_todlf:                          /* Log file datestamp tod */
1651     return tod_stamp(tod_log_datestamp_daily);
1652
1653     case vtype_reply:                          /* Get reply address */
1654     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1655       headers_charset);
1656     if (s != NULL) while (isspace(*s)) s++;
1657     if (s == NULL || *s == 0)
1658       {
1659       *newsize = 0;                            /* For the *s==0 case */
1660       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1661       }
1662     if (s != NULL)
1663       {
1664       uschar *t;
1665       while (isspace(*s)) s++;
1666       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1667       while (t > s && isspace(t[-1])) t--;
1668       *t = 0;
1669       }
1670     return (s == NULL)? US"" : s;
1671
1672     /* A recipients list is available only during system message filtering,
1673     during ACL processing after DATA, and while expanding pipe commands
1674     generated from a system filter, but not elsewhere. */
1675
1676     case vtype_recipients:
1677     if (!enable_dollar_recipients) return NULL; else
1678       {
1679       int size = 128;
1680       int ptr = 0;
1681       int i;
1682       s = store_get(size);
1683       for (i = 0; i < recipients_count; i++)
1684         {
1685         if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1686         s = string_cat(s, &size, &ptr, recipients_list[i].address,
1687           Ustrlen(recipients_list[i].address));
1688         }
1689       s[ptr] = 0;     /* string_cat() leaves room */
1690       }
1691     return s;
1692
1693     case vtype_pspace:
1694       {
1695       int inodes;
1696       sprintf(CS var_buffer, "%d",
1697         receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes));
1698       }
1699     return var_buffer;
1700
1701     case vtype_pinodes:
1702       {
1703       int inodes;
1704       (void) receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes);
1705       sprintf(CS var_buffer, "%d", inodes);
1706       }
1707     return var_buffer;
1708
1709     #ifndef DISABLE_DKIM
1710     case vtype_dkim:
1711     return dkim_exim_expand_query((int)(long)var_table[middle].value);
1712     #endif
1713
1714     }
1715   }
1716
1717 return NULL;          /* Unknown variable name */
1718 }
1719
1720
1721
1722
1723 void
1724 modify_variable(uschar *name, void * value)
1725 {
1726 int first = 0;
1727 int last = var_table_size;
1728
1729 while (last > first)
1730   {
1731   int middle = (first + last)/2;
1732   int c = Ustrcmp(name, var_table[middle].name);
1733
1734   if (c > 0) { first = middle + 1; continue; }
1735   if (c < 0) { last = middle; continue; }
1736
1737   /* Found an existing variable; change the item it refers to */
1738   var_table[middle].value = value;
1739   return;
1740   }
1741 return;          /* Unknown variable name, fail silently */
1742 }
1743
1744
1745
1746
1747
1748 /*************************************************
1749 *           Read and expand substrings           *
1750 *************************************************/
1751
1752 /* This function is called to read and expand argument substrings for various
1753 expansion items. Some have a minimum requirement that is less than the maximum;
1754 in these cases, the first non-present one is set to NULL.
1755
1756 Arguments:
1757   sub        points to vector of pointers to set
1758   n          maximum number of substrings
1759   m          minimum required
1760   sptr       points to current string pointer
1761   skipping   the skipping flag
1762   check_end  if TRUE, check for final '}'
1763   name       name of item, for error message
1764
1765 Returns:     0 OK; string pointer updated
1766              1 curly bracketing error (too few arguments)
1767              2 too many arguments (only if check_end is set); message set
1768              3 other error (expansion failure)
1769 */
1770
1771 static int
1772 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1773   BOOL check_end, uschar *name)
1774 {
1775 int i;
1776 uschar *s = *sptr;
1777
1778 while (isspace(*s)) s++;
1779 for (i = 0; i < n; i++)
1780   {
1781   if (*s != '{')
1782     {
1783     if (i < m) return 1;
1784     sub[i] = NULL;
1785     break;
1786     }
1787   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
1788   if (sub[i] == NULL) return 3;
1789   if (*s++ != '}') return 1;
1790   while (isspace(*s)) s++;
1791   }
1792 if (check_end && *s++ != '}')
1793   {
1794   if (s[-1] == '{')
1795     {
1796     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1797       "(max is %d)", name, n);
1798     return 2;
1799     }
1800   return 1;
1801   }
1802
1803 *sptr = s;
1804 return 0;
1805 }
1806
1807
1808
1809
1810 /*************************************************
1811 *     Elaborate message for bad variable         *
1812 *************************************************/
1813
1814 /* For the "unknown variable" message, take a look at the variable's name, and
1815 give additional information about possible ACL variables. The extra information
1816 is added on to expand_string_message.
1817
1818 Argument:   the name of the variable
1819 Returns:    nothing
1820 */
1821
1822 static void
1823 check_variable_error_message(uschar *name)
1824 {
1825 if (Ustrncmp(name, "acl_", 4) == 0)
1826   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1827     (name[4] == 'c' || name[4] == 'm')?
1828       (isalpha(name[5])?
1829         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1830         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1831       ) :
1832       US"user-defined ACL variables must start acl_c or acl_m");
1833 }
1834
1835
1836
1837 /*************************************************
1838 *        Read and evaluate a condition           *
1839 *************************************************/
1840
1841 /*
1842 Arguments:
1843   s        points to the start of the condition text
1844   yield    points to a BOOL to hold the result of the condition test;
1845            if NULL, we are just reading through a condition that is
1846            part of an "or" combination to check syntax, or in a state
1847            where the answer isn't required
1848
1849 Returns:   a pointer to the first character after the condition, or
1850            NULL after an error
1851 */
1852
1853 static uschar *
1854 eval_condition(uschar *s, BOOL *yield)
1855 {
1856 BOOL testfor = TRUE;
1857 BOOL tempcond, combined_cond;
1858 BOOL *subcondptr;
1859 BOOL sub2_honour_dollar = TRUE;
1860 int i, rc, cond_type, roffset;
1861 int_eximarith_t num[2];
1862 struct stat statbuf;
1863 uschar name[256];
1864 uschar *sub[4];
1865
1866 const pcre *re;
1867 const uschar *rerror;
1868
1869 for (;;)
1870   {
1871   while (isspace(*s)) s++;
1872   if (*s == '!') { testfor = !testfor; s++; } else break;
1873   }
1874
1875 /* Numeric comparisons are symbolic */
1876
1877 if (*s == '=' || *s == '>' || *s == '<')
1878   {
1879   int p = 0;
1880   name[p++] = *s++;
1881   if (*s == '=')
1882     {
1883     name[p++] = '=';
1884     s++;
1885     }
1886   name[p] = 0;
1887   }
1888
1889 /* All other conditions are named */
1890
1891 else s = read_name(name, 256, s, US"_");
1892
1893 /* If we haven't read a name, it means some non-alpha character is first. */
1894
1895 if (name[0] == 0)
1896   {
1897   expand_string_message = string_sprintf("condition name expected, "
1898     "but found \"%.16s\"", s);
1899   return NULL;
1900   }
1901
1902 /* Find which condition we are dealing with, and switch on it */
1903
1904 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1905 switch(cond_type)
1906   {
1907   /* def: tests for a non-empty variable, or for the existence of a header. If
1908   yield == NULL we are in a skipping state, and don't care about the answer. */
1909
1910   case ECOND_DEF:
1911   if (*s != ':')
1912     {
1913     expand_string_message = US"\":\" expected after \"def\"";
1914     return NULL;
1915     }
1916
1917   s = read_name(name, 256, s+1, US"_");
1918
1919   /* Test for a header's existence. If the name contains a closing brace
1920   character, this may be a user error where the terminating colon has been
1921   omitted. Set a flag to adjust a subsequent error message in this case. */
1922
1923   if (Ustrncmp(name, "h_", 2) == 0 ||
1924       Ustrncmp(name, "rh_", 3) == 0 ||
1925       Ustrncmp(name, "bh_", 3) == 0 ||
1926       Ustrncmp(name, "header_", 7) == 0 ||
1927       Ustrncmp(name, "rheader_", 8) == 0 ||
1928       Ustrncmp(name, "bheader_", 8) == 0)
1929     {
1930     s = read_header_name(name, 256, s);
1931     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
1932     if (yield != NULL) *yield =
1933       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1934     }
1935
1936   /* Test for a variable's having a non-empty value. A non-existent variable
1937   causes an expansion failure. */
1938
1939   else
1940     {
1941     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1942     if (value == NULL)
1943       {
1944       expand_string_message = (name[0] == 0)?
1945         string_sprintf("variable name omitted after \"def:\"") :
1946         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1947       check_variable_error_message(name);
1948       return NULL;
1949       }
1950     if (yield != NULL) *yield = (value[0] != 0) == testfor;
1951     }
1952
1953   return s;
1954
1955
1956   /* first_delivery tests for first delivery attempt */
1957
1958   case ECOND_FIRST_DELIVERY:
1959   if (yield != NULL) *yield = deliver_firsttime == testfor;
1960   return s;
1961
1962
1963   /* queue_running tests for any process started by a queue runner */
1964
1965   case ECOND_QUEUE_RUNNING:
1966   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
1967   return s;
1968
1969
1970   /* exists:  tests for file existence
1971        isip:  tests for any IP address
1972       isip4:  tests for an IPv4 address
1973       isip6:  tests for an IPv6 address
1974         pam:  does PAM authentication
1975      radius:  does RADIUS authentication
1976    ldapauth:  does LDAP authentication
1977     pwcheck:  does Cyrus SASL pwcheck authentication
1978   */
1979
1980   case ECOND_EXISTS:
1981   case ECOND_ISIP:
1982   case ECOND_ISIP4:
1983   case ECOND_ISIP6:
1984   case ECOND_PAM:
1985   case ECOND_RADIUS:
1986   case ECOND_LDAPAUTH:
1987   case ECOND_PWCHECK:
1988
1989   while (isspace(*s)) s++;
1990   if (*s != '{') goto COND_FAILED_CURLY_START;
1991
1992   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE);
1993   if (sub[0] == NULL) return NULL;
1994   if (*s++ != '}') goto COND_FAILED_CURLY_END;
1995
1996   if (yield == NULL) return s;   /* No need to run the test if skipping */
1997
1998   switch(cond_type)
1999     {
2000     case ECOND_EXISTS:
2001     if ((expand_forbid & RDO_EXISTS) != 0)
2002       {
2003       expand_string_message = US"File existence tests are not permitted";
2004       return NULL;
2005       }
2006     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2007     break;
2008
2009     case ECOND_ISIP:
2010     case ECOND_ISIP4:
2011     case ECOND_ISIP6:
2012     rc = string_is_ip_address(sub[0], NULL);
2013     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2014              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2015     break;
2016
2017     /* Various authentication tests - all optionally compiled */
2018
2019     case ECOND_PAM:
2020     #ifdef SUPPORT_PAM
2021     rc = auth_call_pam(sub[0], &expand_string_message);
2022     goto END_AUTH;
2023     #else
2024     goto COND_FAILED_NOT_COMPILED;
2025     #endif  /* SUPPORT_PAM */
2026
2027     case ECOND_RADIUS:
2028     #ifdef RADIUS_CONFIG_FILE
2029     rc = auth_call_radius(sub[0], &expand_string_message);
2030     goto END_AUTH;
2031     #else
2032     goto COND_FAILED_NOT_COMPILED;
2033     #endif  /* RADIUS_CONFIG_FILE */
2034
2035     case ECOND_LDAPAUTH:
2036     #ifdef LOOKUP_LDAP
2037       {
2038       /* Just to keep the interface the same */
2039       BOOL do_cache;
2040       int old_pool = store_pool;
2041       store_pool = POOL_SEARCH;
2042       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2043         &expand_string_message, &do_cache);
2044       store_pool = old_pool;
2045       }
2046     goto END_AUTH;
2047     #else
2048     goto COND_FAILED_NOT_COMPILED;
2049     #endif  /* LOOKUP_LDAP */
2050
2051     case ECOND_PWCHECK:
2052     #ifdef CYRUS_PWCHECK_SOCKET
2053     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2054     goto END_AUTH;
2055     #else
2056     goto COND_FAILED_NOT_COMPILED;
2057     #endif  /* CYRUS_PWCHECK_SOCKET */
2058
2059     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2060         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2061     END_AUTH:
2062     if (rc == ERROR || rc == DEFER) return NULL;
2063     *yield = (rc == OK) == testfor;
2064     #endif
2065     }
2066   return s;
2067
2068
2069   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2070
2071      ${if saslauthd {{username}{password}{service}{realm}}  {yes}[no}}
2072
2073   However, the last two are optional. That is why the whole set is enclosed
2074   in their own set or braces. */
2075
2076   case ECOND_SASLAUTHD:
2077   #ifndef CYRUS_SASLAUTHD_SOCKET
2078   goto COND_FAILED_NOT_COMPILED;
2079   #else
2080   while (isspace(*s)) s++;
2081   if (*s++ != '{') goto COND_FAILED_CURLY_START;
2082   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
2083     {
2084     case 1: expand_string_message = US"too few arguments or bracketing "
2085       "error for saslauthd";
2086     case 2:
2087     case 3: return NULL;
2088     }
2089   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2090   if (yield != NULL)
2091     {
2092     int rc;
2093     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2094       &expand_string_message);
2095     if (rc == ERROR || rc == DEFER) return NULL;
2096     *yield = (rc == OK) == testfor;
2097     }
2098   return s;
2099   #endif /* CYRUS_SASLAUTHD_SOCKET */
2100
2101
2102   /* symbolic operators for numeric and string comparison, and a number of
2103   other operators, all requiring two arguments.
2104
2105   crypteq:           encrypts plaintext and compares against an encrypted text,
2106                        using crypt(), crypt16(), MD5 or SHA-1
2107   inlist/inlisti:    checks if first argument is in the list of the second
2108   match:             does a regular expression match and sets up the numerical
2109                        variables if it succeeds
2110   match_address:     matches in an address list
2111   match_domain:      matches in a domain list
2112   match_ip:          matches a host list that is restricted to IP addresses
2113   match_local_part:  matches in a local part list
2114   */
2115
2116   case ECOND_MATCH_ADDRESS:
2117   case ECOND_MATCH_DOMAIN:
2118   case ECOND_MATCH_IP:
2119   case ECOND_MATCH_LOCAL_PART:
2120 #ifndef EXPAND_LISTMATCH_RHS
2121     sub2_honour_dollar = FALSE;
2122 #endif
2123     /* FALLTHROUGH */
2124
2125   case ECOND_CRYPTEQ:
2126   case ECOND_INLIST:
2127   case ECOND_INLISTI:
2128   case ECOND_MATCH:
2129
2130   case ECOND_NUM_L:     /* Numerical comparisons */
2131   case ECOND_NUM_LE:
2132   case ECOND_NUM_E:
2133   case ECOND_NUM_EE:
2134   case ECOND_NUM_G:
2135   case ECOND_NUM_GE:
2136
2137   case ECOND_STR_LT:    /* String comparisons */
2138   case ECOND_STR_LTI:
2139   case ECOND_STR_LE:
2140   case ECOND_STR_LEI:
2141   case ECOND_STR_EQ:
2142   case ECOND_STR_EQI:
2143   case ECOND_STR_GT:
2144   case ECOND_STR_GTI:
2145   case ECOND_STR_GE:
2146   case ECOND_STR_GEI:
2147
2148   for (i = 0; i < 2; i++)
2149     {
2150     /* Sometimes, we don't expand substrings; too many insecure configurations
2151     created using match_address{}{} and friends, where the second param
2152     includes information from untrustworthy sources. */
2153     BOOL honour_dollar = TRUE;
2154     if ((i > 0) && !sub2_honour_dollar)
2155       honour_dollar = FALSE;
2156
2157     while (isspace(*s)) s++;
2158     if (*s != '{')
2159       {
2160       if (i == 0) goto COND_FAILED_CURLY_START;
2161       expand_string_message = string_sprintf("missing 2nd string in {} "
2162         "after \"%s\"", name);
2163       return NULL;
2164       }
2165     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2166         honour_dollar);
2167     if (sub[i] == NULL) return NULL;
2168     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2169
2170     /* Convert to numerical if required; we know that the names of all the
2171     conditions that compare numbers do not start with a letter. This just saves
2172     checking for them individually. */
2173
2174     if (!isalpha(name[0]) && yield != NULL)
2175       {
2176       if (sub[i][0] == 0)
2177         {
2178         num[i] = 0;
2179         DEBUG(D_expand)
2180           debug_printf("empty string cast to zero for numerical comparison\n");
2181         }
2182       else
2183         {
2184         num[i] = expand_string_integer(sub[i], FALSE);
2185         if (expand_string_message != NULL) return NULL;
2186         }
2187       }
2188     }
2189
2190   /* Result not required */
2191
2192   if (yield == NULL) return s;
2193
2194   /* Do an appropriate comparison */
2195
2196   switch(cond_type)
2197     {
2198     case ECOND_NUM_E:
2199     case ECOND_NUM_EE:
2200     *yield = (num[0] == num[1]) == testfor;
2201     break;
2202
2203     case ECOND_NUM_G:
2204     *yield = (num[0] > num[1]) == testfor;
2205     break;
2206
2207     case ECOND_NUM_GE:
2208     *yield = (num[0] >= num[1]) == testfor;
2209     break;
2210
2211     case ECOND_NUM_L:
2212     *yield = (num[0] < num[1]) == testfor;
2213     break;
2214
2215     case ECOND_NUM_LE:
2216     *yield = (num[0] <= num[1]) == testfor;
2217     break;
2218
2219     case ECOND_STR_LT:
2220     *yield = (Ustrcmp(sub[0], sub[1]) < 0) == testfor;
2221     break;
2222
2223     case ECOND_STR_LTI:
2224     *yield = (strcmpic(sub[0], sub[1]) < 0) == testfor;
2225     break;
2226
2227     case ECOND_STR_LE:
2228     *yield = (Ustrcmp(sub[0], sub[1]) <= 0) == testfor;
2229     break;
2230
2231     case ECOND_STR_LEI:
2232     *yield = (strcmpic(sub[0], sub[1]) <= 0) == testfor;
2233     break;
2234
2235     case ECOND_STR_EQ:
2236     *yield = (Ustrcmp(sub[0], sub[1]) == 0) == testfor;
2237     break;
2238
2239     case ECOND_STR_EQI:
2240     *yield = (strcmpic(sub[0], sub[1]) == 0) == testfor;
2241     break;
2242
2243     case ECOND_STR_GT:
2244     *yield = (Ustrcmp(sub[0], sub[1]) > 0) == testfor;
2245     break;
2246
2247     case ECOND_STR_GTI:
2248     *yield = (strcmpic(sub[0], sub[1]) > 0) == testfor;
2249     break;
2250
2251     case ECOND_STR_GE:
2252     *yield = (Ustrcmp(sub[0], sub[1]) >= 0) == testfor;
2253     break;
2254
2255     case ECOND_STR_GEI:
2256     *yield = (strcmpic(sub[0], sub[1]) >= 0) == testfor;
2257     break;
2258
2259     case ECOND_MATCH:   /* Regular expression match */
2260     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2261       NULL);
2262     if (re == NULL)
2263       {
2264       expand_string_message = string_sprintf("regular expression error in "
2265         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2266       return NULL;
2267       }
2268     *yield = regex_match_and_setup(re, sub[0], 0, -1) == testfor;
2269     break;
2270
2271     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2272     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2273     goto MATCHED_SOMETHING;
2274
2275     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2276     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2277       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2278     goto MATCHED_SOMETHING;
2279
2280     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2281     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2282       {
2283       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2284         sub[0]);
2285       return NULL;
2286       }
2287     else
2288       {
2289       unsigned int *nullcache = NULL;
2290       check_host_block cb;
2291
2292       cb.host_name = US"";
2293       cb.host_address = sub[0];
2294
2295       /* If the host address starts off ::ffff: it is an IPv6 address in
2296       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2297       addresses. */
2298
2299       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2300         cb.host_address + 7 : cb.host_address;
2301
2302       rc = match_check_list(
2303              &sub[1],                   /* the list */
2304              0,                         /* separator character */
2305              &hostlist_anchor,          /* anchor pointer */
2306              &nullcache,                /* cache pointer */
2307              check_host,                /* function for testing */
2308              &cb,                       /* argument for function */
2309              MCL_HOST,                  /* type of check */
2310              sub[0],                    /* text for debugging */
2311              NULL);                     /* where to pass back data */
2312       }
2313     goto MATCHED_SOMETHING;
2314
2315     case ECOND_MATCH_LOCAL_PART:
2316     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2317       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2318     /* Fall through */
2319     /* VVVVVVVVVVVV */
2320     MATCHED_SOMETHING:
2321     switch(rc)
2322       {
2323       case OK:
2324       *yield = testfor;
2325       break;
2326
2327       case FAIL:
2328       *yield = !testfor;
2329       break;
2330
2331       case DEFER:
2332       expand_string_message = string_sprintf("unable to complete match "
2333         "against \"%s\": %s", sub[1], search_error_message);
2334       return NULL;
2335       }
2336
2337     break;
2338
2339     /* Various "encrypted" comparisons. If the second string starts with
2340     "{" then an encryption type is given. Default to crypt() or crypt16()
2341     (build-time choice). */
2342
2343     case ECOND_CRYPTEQ:
2344     #ifndef SUPPORT_CRYPTEQ
2345     goto COND_FAILED_NOT_COMPILED;
2346     #else
2347     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2348       {
2349       int sublen = Ustrlen(sub[1]+5);
2350       md5 base;
2351       uschar digest[16];
2352
2353       md5_start(&base);
2354       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2355
2356       /* If the length that we are comparing against is 24, the MD5 digest
2357       is expressed as a base64 string. This is the way LDAP does it. However,
2358       some other software uses a straightforward hex representation. We assume
2359       this if the length is 32. Other lengths fail. */
2360
2361       if (sublen == 24)
2362         {
2363         uschar *coded = auth_b64encode((uschar *)digest, 16);
2364         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2365           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2366         *yield = (Ustrcmp(coded, sub[1]+5) == 0) == testfor;
2367         }
2368       else if (sublen == 32)
2369         {
2370         int i;
2371         uschar coded[36];
2372         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2373         coded[32] = 0;
2374         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2375           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2376         *yield = (strcmpic(coded, sub[1]+5) == 0) == testfor;
2377         }
2378       else
2379         {
2380         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2381           "fail\n  crypted=%s\n", sub[1]+5);
2382         *yield = !testfor;
2383         }
2384       }
2385
2386     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2387       {
2388       int sublen = Ustrlen(sub[1]+6);
2389       sha1 base;
2390       uschar digest[20];
2391
2392       sha1_start(&base);
2393       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2394
2395       /* If the length that we are comparing against is 28, assume the SHA1
2396       digest is expressed as a base64 string. If the length is 40, assume a
2397       straightforward hex representation. Other lengths fail. */
2398
2399       if (sublen == 28)
2400         {
2401         uschar *coded = auth_b64encode((uschar *)digest, 20);
2402         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2403           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2404         *yield = (Ustrcmp(coded, sub[1]+6) == 0) == testfor;
2405         }
2406       else if (sublen == 40)
2407         {
2408         int i;
2409         uschar coded[44];
2410         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2411         coded[40] = 0;
2412         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2413           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2414         *yield = (strcmpic(coded, sub[1]+6) == 0) == testfor;
2415         }
2416       else
2417         {
2418         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2419           "fail\n  crypted=%s\n", sub[1]+6);
2420         *yield = !testfor;
2421         }
2422       }
2423
2424     else   /* {crypt} or {crypt16} and non-{ at start */
2425            /* }-for-text-editors */
2426       {
2427       int which = 0;
2428       uschar *coded;
2429
2430       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2431         {
2432         sub[1] += 7;
2433         which = 1;
2434         }
2435       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2436         {
2437         sub[1] += 9;
2438         which = 2;
2439         }
2440       else if (sub[1][0] == '{')
2441         {
2442         expand_string_message = string_sprintf("unknown encryption mechanism "
2443           "in \"%s\"", sub[1]);
2444         return NULL;
2445         }
2446
2447       switch(which)
2448         {
2449         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2450         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2451         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2452         }
2453
2454       #define STR(s) # s
2455       #define XSTR(s) STR(s)
2456       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2457         "  subject=%s\n  crypted=%s\n",
2458         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2459         coded, sub[1]);
2460       #undef STR
2461       #undef XSTR
2462
2463       /* If the encrypted string contains fewer than two characters (for the
2464       salt), force failure. Otherwise we get false positives: with an empty
2465       string the yield of crypt() is an empty string! */
2466
2467       *yield = (Ustrlen(sub[1]) < 2)? !testfor :
2468         (Ustrcmp(coded, sub[1]) == 0) == testfor;
2469       }
2470     break;
2471     #endif  /* SUPPORT_CRYPTEQ */
2472
2473     case ECOND_INLIST:
2474     case ECOND_INLISTI:
2475       {
2476       int sep = 0;
2477       BOOL found = FALSE;
2478       uschar *save_iterate_item = iterate_item;
2479       int (*compare)(const uschar *, const uschar *);
2480
2481       if (cond_type == ECOND_INLISTI)
2482         compare = strcmpic;
2483       else
2484         compare = (int (*)(const uschar *, const uschar *)) strcmp;
2485
2486       while ((iterate_item = string_nextinlist(&sub[1], &sep, NULL, 0)) != NULL)
2487         if (compare(sub[0], iterate_item) == 0)
2488           {
2489           found = TRUE;
2490           break;
2491           }
2492       iterate_item = save_iterate_item;
2493       *yield = found;
2494       }
2495
2496     }   /* Switch for comparison conditions */
2497
2498   return s;    /* End of comparison conditions */
2499
2500
2501   /* and/or: computes logical and/or of several conditions */
2502
2503   case ECOND_AND:
2504   case ECOND_OR:
2505   subcondptr = (yield == NULL)? NULL : &tempcond;
2506   combined_cond = (cond_type == ECOND_AND);
2507
2508   while (isspace(*s)) s++;
2509   if (*s++ != '{') goto COND_FAILED_CURLY_START;
2510
2511   for (;;)
2512     {
2513     while (isspace(*s)) s++;
2514     if (*s == '}') break;
2515     if (*s != '{')
2516       {
2517       expand_string_message = string_sprintf("each subcondition "
2518         "inside an \"%s{...}\" condition must be in its own {}", name);
2519       return NULL;
2520       }
2521
2522     s = eval_condition(s+1, subcondptr);
2523     if (s == NULL)
2524       {
2525       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2526         expand_string_message, name);
2527       return NULL;
2528       }
2529     while (isspace(*s)) s++;
2530
2531     if (*s++ != '}')
2532       {
2533       expand_string_message = string_sprintf("missing } at end of condition "
2534         "inside \"%s\" group", name);
2535       return NULL;
2536       }
2537
2538     if (yield != NULL)
2539       {
2540       if (cond_type == ECOND_AND)
2541         {
2542         combined_cond &= tempcond;
2543         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2544         }                                       /* evaluate any more */
2545       else
2546         {
2547         combined_cond |= tempcond;
2548         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2549         }                                       /* evaluate any more */
2550       }
2551     }
2552
2553   if (yield != NULL) *yield = (combined_cond == testfor);
2554   return ++s;
2555
2556
2557   /* forall/forany: iterates a condition with different values */
2558
2559   case ECOND_FORALL:
2560   case ECOND_FORANY:
2561     {
2562     int sep = 0;
2563     uschar *save_iterate_item = iterate_item;
2564
2565     while (isspace(*s)) s++;
2566     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2567     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE);
2568     if (sub[0] == NULL) return NULL;
2569     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2570
2571     while (isspace(*s)) s++;
2572     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2573
2574     sub[1] = s;
2575
2576     /* Call eval_condition once, with result discarded (as if scanning a
2577     "false" part). This allows us to find the end of the condition, because if
2578     the list it empty, we won't actually evaluate the condition for real. */
2579
2580     s = eval_condition(sub[1], NULL);
2581     if (s == NULL)
2582       {
2583       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2584         expand_string_message, name);
2585       return NULL;
2586       }
2587     while (isspace(*s)) s++;
2588
2589     if (*s++ != '}')
2590       {
2591       expand_string_message = string_sprintf("missing } at end of condition "
2592         "inside \"%s\"", name);
2593       return NULL;
2594       }
2595
2596     if (yield != NULL) *yield = !testfor;
2597     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2598       {
2599       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2600       if (eval_condition(sub[1], &tempcond) == NULL)
2601         {
2602         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2603           expand_string_message, name);
2604         iterate_item = save_iterate_item;
2605         return NULL;
2606         }
2607       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2608         tempcond? "true":"false");
2609
2610       if (yield != NULL) *yield = (tempcond == testfor);
2611       if (tempcond == (cond_type == ECOND_FORANY)) break;
2612       }
2613
2614     iterate_item = save_iterate_item;
2615     return s;
2616     }
2617
2618
2619   /* The bool{} expansion condition maps a string to boolean.
2620   The values supported should match those supported by the ACL condition
2621   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2622   of true/false.  Note that Router "condition" rules have a different
2623   interpretation, where general data can be used and only a few values
2624   map to FALSE.
2625   Note that readconf.c boolean matching, for boolean configuration options,
2626   only matches true/yes/false/no.
2627   The bool_lax{} condition matches the Router logic, which is much more
2628   liberal. */
2629   case ECOND_BOOL:
2630   case ECOND_BOOL_LAX:
2631     {
2632     uschar *sub_arg[1];
2633     uschar *t, *t2;
2634     uschar *ourname;
2635     size_t len;
2636     BOOL boolvalue = FALSE;
2637     while (isspace(*s)) s++;
2638     if (*s != '{') goto COND_FAILED_CURLY_START;
2639     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2640     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname))
2641       {
2642       case 1: expand_string_message = string_sprintf(
2643                   "too few arguments or bracketing error for %s",
2644                   ourname);
2645       /*FALLTHROUGH*/
2646       case 2:
2647       case 3: return NULL;
2648       }
2649     t = sub_arg[0];
2650     while (isspace(*t)) t++;
2651     len = Ustrlen(t);
2652     if (len)
2653       {
2654       /* trailing whitespace: seems like a good idea to ignore it too */
2655       t2 = t + len - 1;
2656       while (isspace(*t2)) t2--;
2657       if (t2 != (t + len))
2658         {
2659         *++t2 = '\0';
2660         len = t2 - t;
2661         }
2662       }
2663     DEBUG(D_expand)
2664       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
2665     /* logic for the lax case from expand_check_condition(), which also does
2666     expands, and the logic is both short and stable enough that there should
2667     be no maintenance burden from replicating it. */
2668     if (len == 0)
2669       boolvalue = FALSE;
2670     else if (Ustrspn(t, "0123456789") == len)
2671       {
2672       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
2673       /* expand_check_condition only does a literal string "0" check */
2674       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
2675         boolvalue = TRUE;
2676       }
2677     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
2678       boolvalue = TRUE;
2679     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
2680       boolvalue = FALSE;
2681     else if (cond_type == ECOND_BOOL_LAX)
2682       boolvalue = TRUE;
2683     else
2684       {
2685       expand_string_message = string_sprintf("unrecognised boolean "
2686        "value \"%s\"", t);
2687       return NULL;
2688       }
2689     if (yield != NULL) *yield = (boolvalue == testfor);
2690     return s;
2691     }
2692
2693   /* Unknown condition */
2694
2695   default:
2696   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2697   return NULL;
2698   }   /* End switch on condition type */
2699
2700 /* Missing braces at start and end of data */
2701
2702 COND_FAILED_CURLY_START:
2703 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2704 return NULL;
2705
2706 COND_FAILED_CURLY_END:
2707 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2708   name);
2709 return NULL;
2710
2711 /* A condition requires code that is not compiled */
2712
2713 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2714     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2715     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2716 COND_FAILED_NOT_COMPILED:
2717 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2718   name);
2719 return NULL;
2720 #endif
2721 }
2722
2723
2724
2725
2726 /*************************************************
2727 *          Save numerical variables              *
2728 *************************************************/
2729
2730 /* This function is called from items such as "if" that want to preserve and
2731 restore the numbered variables.
2732
2733 Arguments:
2734   save_expand_string    points to an array of pointers to set
2735   save_expand_nlength   points to an array of ints for the lengths
2736
2737 Returns:                the value of expand max to save
2738 */
2739
2740 static int
2741 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2742 {
2743 int i;
2744 for (i = 0; i <= expand_nmax; i++)
2745   {
2746   save_expand_nstring[i] = expand_nstring[i];
2747   save_expand_nlength[i] = expand_nlength[i];
2748   }
2749 return expand_nmax;
2750 }
2751
2752
2753
2754 /*************************************************
2755 *           Restore numerical variables          *
2756 *************************************************/
2757
2758 /* This function restored saved values of numerical strings.
2759
2760 Arguments:
2761   save_expand_nmax      the number of strings to restore
2762   save_expand_string    points to an array of pointers
2763   save_expand_nlength   points to an array of ints
2764
2765 Returns:                nothing
2766 */
2767
2768 static void
2769 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2770   int *save_expand_nlength)
2771 {
2772 int i;
2773 expand_nmax = save_expand_nmax;
2774 for (i = 0; i <= expand_nmax; i++)
2775   {
2776   expand_nstring[i] = save_expand_nstring[i];
2777   expand_nlength[i] = save_expand_nlength[i];
2778   }
2779 }
2780
2781
2782
2783
2784
2785 /*************************************************
2786 *            Handle yes/no substrings            *
2787 *************************************************/
2788
2789 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2790 alternative substrings that depend on whether or not the condition was true,
2791 or the lookup or extraction succeeded. The substrings always have to be
2792 expanded, to check their syntax, but "skipping" is set when the result is not
2793 needed - this avoids unnecessary nested lookups.
2794
2795 Arguments:
2796   skipping       TRUE if we were skipping when this item was reached
2797   yes            TRUE if the first string is to be used, else use the second
2798   save_lookup    a value to put back into lookup_value before the 2nd expansion
2799   sptr           points to the input string pointer
2800   yieldptr       points to the output string pointer
2801   sizeptr        points to the output string size
2802   ptrptr         points to the output string pointer
2803   type           "lookup" or "if" or "extract" or "run", for error message
2804
2805 Returns:         0 OK; lookup_value has been reset to save_lookup
2806                  1 expansion failed
2807                  2 expansion failed because of bracketing error
2808 */
2809
2810 static int
2811 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2812   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2813 {
2814 int rc = 0;
2815 uschar *s = *sptr;    /* Local value */
2816 uschar *sub1, *sub2;
2817
2818 /* If there are no following strings, we substitute the contents of $value for
2819 lookups and for extractions in the success case. For the ${if item, the string
2820 "true" is substituted. In the fail case, nothing is substituted for all three
2821 items. */
2822
2823 while (isspace(*s)) s++;
2824 if (*s == '}')
2825   {
2826   if (type[0] == 'i')
2827     {
2828     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2829     }
2830   else
2831     {
2832     if (yes && lookup_value != NULL)
2833       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2834         Ustrlen(lookup_value));
2835     lookup_value = save_lookup;
2836     }
2837   s++;
2838   goto RETURN;
2839   }
2840
2841 /* The first following string must be braced. */
2842
2843 if (*s++ != '{') goto FAILED_CURLY;
2844
2845 /* Expand the first substring. Forced failures are noticed only if we actually
2846 want this string. Set skipping in the call in the fail case (this will always
2847 be the case if we were already skipping). */
2848
2849 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE);
2850 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2851 expand_string_forcedfail = FALSE;
2852 if (*s++ != '}') goto FAILED_CURLY;
2853
2854 /* If we want the first string, add it to the output */
2855
2856 if (yes)
2857   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2858
2859 /* If this is called from a lookup or an extract, we want to restore $value to
2860 what it was at the start of the item, so that it has this value during the
2861 second string expansion. For the call from "if" or "run" to this function,
2862 save_lookup is set to lookup_value, so that this statement does nothing. */
2863
2864 lookup_value = save_lookup;
2865
2866 /* There now follows either another substring, or "fail", or nothing. This
2867 time, forced failures are noticed only if we want the second string. We must
2868 set skipping in the nested call if we don't want this string, or if we were
2869 already skipping. */
2870
2871 while (isspace(*s)) s++;
2872 if (*s == '{')
2873   {
2874   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE);
2875   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2876   expand_string_forcedfail = FALSE;
2877   if (*s++ != '}') goto FAILED_CURLY;
2878
2879   /* If we want the second string, add it to the output */
2880
2881   if (!yes)
2882     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2883   }
2884
2885 /* If there is no second string, but the word "fail" is present when the use of
2886 the second string is wanted, set a flag indicating it was a forced failure
2887 rather than a syntactic error. Swallow the terminating } in case this is nested
2888 inside another lookup or if or extract. */
2889
2890 else if (*s != '}')
2891   {
2892   uschar name[256];
2893   s = read_name(name, sizeof(name), s, US"_");
2894   if (Ustrcmp(name, "fail") == 0)
2895     {
2896     if (!yes && !skipping)
2897       {
2898       while (isspace(*s)) s++;
2899       if (*s++ != '}') goto FAILED_CURLY;
2900       expand_string_message =
2901         string_sprintf("\"%s\" failed and \"fail\" requested", type);
2902       expand_string_forcedfail = TRUE;
2903       goto FAILED;
2904       }
2905     }
2906   else
2907     {
2908     expand_string_message =
2909       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
2910     goto FAILED;
2911     }
2912   }
2913
2914 /* All we have to do now is to check on the final closing brace. */
2915
2916 while (isspace(*s)) s++;
2917 if (*s++ == '}') goto RETURN;
2918
2919 /* Get here if there is a bracketing failure */
2920
2921 FAILED_CURLY:
2922 rc++;
2923
2924 /* Get here for other failures */
2925
2926 FAILED:
2927 rc++;
2928
2929 /* Update the input pointer value before returning */
2930
2931 RETURN:
2932 *sptr = s;
2933 return rc;
2934 }
2935
2936
2937
2938
2939 /*************************************************
2940 *    Handle MD5 or SHA-1 computation for HMAC    *
2941 *************************************************/
2942
2943 /* These are some wrapping functions that enable the HMAC code to be a bit
2944 cleaner. A good compiler will spot the tail recursion.
2945
2946 Arguments:
2947   type         HMAC_MD5 or HMAC_SHA1
2948   remaining    are as for the cryptographic hash functions
2949
2950 Returns:       nothing
2951 */
2952
2953 static void
2954 chash_start(int type, void *base)
2955 {
2956 if (type == HMAC_MD5)
2957   md5_start((md5 *)base);
2958 else
2959   sha1_start((sha1 *)base);
2960 }
2961
2962 static void
2963 chash_mid(int type, void *base, uschar *string)
2964 {
2965 if (type == HMAC_MD5)
2966   md5_mid((md5 *)base, string);
2967 else
2968   sha1_mid((sha1 *)base, string);
2969 }
2970
2971 static void
2972 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
2973 {
2974 if (type == HMAC_MD5)
2975   md5_end((md5 *)base, string, length, digest);
2976 else
2977   sha1_end((sha1 *)base, string, length, digest);
2978 }
2979
2980
2981
2982
2983
2984 /********************************************************
2985 * prvs: Get last three digits of days since Jan 1, 1970 *
2986 ********************************************************/
2987
2988 /* This is needed to implement the "prvs" BATV reverse
2989    path signing scheme
2990
2991 Argument: integer "days" offset to add or substract to
2992           or from the current number of days.
2993
2994 Returns:  pointer to string containing the last three
2995           digits of the number of days since Jan 1, 1970,
2996           modified by the offset argument, NULL if there
2997           was an error in the conversion.
2998
2999 */
3000
3001 static uschar *
3002 prvs_daystamp(int day_offset)
3003 {
3004 uschar *days = store_get(32);                /* Need at least 24 for cases */
3005 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3006   (time(NULL) + day_offset*86400)/86400);
3007 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3008 }
3009
3010
3011
3012 /********************************************************
3013 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3014 ********************************************************/
3015
3016 /* This is needed to implement the "prvs" BATV reverse
3017    path signing scheme
3018
3019 Arguments:
3020   address RFC2821 Address to use
3021       key The key to use (must be less than 64 characters
3022           in size)
3023   key_num Single-digit key number to use. Defaults to
3024           '0' when NULL.
3025
3026 Returns:  pointer to string containing the first three
3027           bytes of the final hash in hex format, NULL if
3028           there was an error in the process.
3029 */
3030
3031 static uschar *
3032 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3033 {
3034 uschar *hash_source, *p;
3035 int size = 0,offset = 0,i;
3036 sha1 sha1_base;
3037 void *use_base = &sha1_base;
3038 uschar innerhash[20];
3039 uschar finalhash[20];
3040 uschar innerkey[64];
3041 uschar outerkey[64];
3042 uschar *finalhash_hex = store_get(40);
3043
3044 if (key_num == NULL)
3045   key_num = US"0";
3046
3047 if (Ustrlen(key) > 64)
3048   return NULL;
3049
3050 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3051 string_cat(hash_source,&size,&offset,daystamp,3);
3052 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3053 hash_source[offset] = '\0';
3054
3055 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3056
3057 memset(innerkey, 0x36, 64);
3058 memset(outerkey, 0x5c, 64);
3059
3060 for (i = 0; i < Ustrlen(key); i++)
3061   {
3062   innerkey[i] ^= key[i];
3063   outerkey[i] ^= key[i];
3064   }
3065
3066 chash_start(HMAC_SHA1, use_base);
3067 chash_mid(HMAC_SHA1, use_base, innerkey);
3068 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3069
3070 chash_start(HMAC_SHA1, use_base);
3071 chash_mid(HMAC_SHA1, use_base, outerkey);
3072 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3073
3074 p = finalhash_hex;
3075 for (i = 0; i < 3; i++)
3076   {
3077   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3078   *p++ = hex_digits[finalhash[i] & 0x0f];
3079   }
3080 *p = '\0';
3081
3082 return finalhash_hex;
3083 }
3084
3085
3086
3087
3088 /*************************************************
3089 *        Join a file onto the output string      *
3090 *************************************************/
3091
3092 /* This is used for readfile and after a run expansion. It joins the contents
3093 of a file onto the output string, globally replacing newlines with a given
3094 string (optionally). The file is closed at the end.
3095
3096 Arguments:
3097   f            the FILE
3098   yield        pointer to the expandable string
3099   sizep        pointer to the current size
3100   ptrp         pointer to the current position
3101   eol          newline replacement string, or NULL
3102
3103 Returns:       new value of string pointer
3104 */
3105
3106 static uschar *
3107 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3108 {
3109 int eollen;
3110 uschar buffer[1024];
3111
3112 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3113
3114 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3115   {
3116   int len = Ustrlen(buffer);
3117   if (eol != NULL && buffer[len-1] == '\n') len--;
3118   yield = string_cat(yield, sizep, ptrp, buffer, len);
3119   if (buffer[len] != 0)
3120     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3121   }
3122
3123 if (yield != NULL) yield[*ptrp] = 0;
3124
3125 return yield;
3126 }
3127
3128
3129
3130
3131 /*************************************************
3132 *          Evaluate numeric expression           *
3133 *************************************************/
3134
3135 /* This is a set of mutually recursive functions that evaluate an arithmetic
3136 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3137 these functions that is called from elsewhere is eval_expr, whose interface is:
3138
3139 Arguments:
3140   sptr        pointer to the pointer to the string - gets updated
3141   decimal     TRUE if numbers are to be assumed decimal
3142   error       pointer to where to put an error message - must be NULL on input
3143   endket      TRUE if ')' must terminate - FALSE for external call
3144
3145 Returns:      on success: the value of the expression, with *error still NULL
3146               on failure: an undefined value, with *error = a message
3147 */
3148
3149 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3150
3151
3152 static int_eximarith_t
3153 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3154 {
3155 uschar *s = *sptr;
3156 int_eximarith_t x = eval_op_or(&s, decimal, error);
3157 if (*error == NULL)
3158   {
3159   if (endket)
3160     {
3161     if (*s != ')')
3162       *error = US"expecting closing parenthesis";
3163     else
3164       while (isspace(*(++s)));
3165     }
3166   else if (*s != 0) *error = US"expecting operator";
3167   }
3168 *sptr = s;
3169 return x;
3170 }
3171
3172
3173 static int_eximarith_t
3174 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3175 {
3176 register int c;
3177 int_eximarith_t n;
3178 uschar *s = *sptr;
3179 while (isspace(*s)) s++;
3180 c = *s;
3181 if (isdigit(c))
3182   {
3183   int count;
3184   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3185   s += count;
3186   switch (tolower(*s))
3187     {
3188     default: break;
3189     case 'k': n *= 1024; s++; break;
3190     case 'm': n *= 1024*1024; s++; break;
3191     case 'g': n *= 1024*1024*1024; s++; break;
3192     }
3193   while (isspace (*s)) s++;
3194   }
3195 else if (c == '(')
3196   {
3197   s++;
3198   n = eval_expr(&s, decimal, error, 1);
3199   }
3200 else
3201   {
3202   *error = US"expecting number or opening parenthesis";
3203   n = 0;
3204   }
3205 *sptr = s;
3206 return n;
3207 }
3208
3209
3210 static int_eximarith_t
3211 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3212 {
3213 uschar *s = *sptr;
3214 int_eximarith_t x;
3215 while (isspace(*s)) s++;
3216 if (*s == '+' || *s == '-' || *s == '~')
3217   {
3218   int op = *s++;
3219   x = eval_op_unary(&s, decimal, error);
3220   if (op == '-') x = -x;
3221     else if (op == '~') x = ~x;
3222   }
3223 else
3224   {
3225   x = eval_number(&s, decimal, error);
3226   }
3227 *sptr = s;
3228 return x;
3229 }
3230
3231
3232 static int_eximarith_t
3233 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3234 {
3235 uschar *s = *sptr;
3236 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3237 if (*error == NULL)
3238   {
3239   while (*s == '*' || *s == '/' || *s == '%')
3240     {
3241     int op = *s++;
3242     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3243     if (*error != NULL) break;
3244     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3245      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3246      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3247      * -N*M is INT_MIN will yielf INT_MIN.
3248      * Since we don't support floating point, this is somewhat simpler.
3249      * Ideally, we'd return an error, but since we overflow for all other
3250      * arithmetic, consistency suggests otherwise, but what's the correct value
3251      * to use?  There is none.
3252      * The C standard guarantees overflow for unsigned arithmetic but signed
3253      * overflow invokes undefined behaviour; in practice, this is overflow
3254      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3255      * that long/longlong larger than int are available, or we could just work
3256      * with larger types.  We should consider whether to guarantee 32bit eval
3257      * and 64-bit working variables, with errors returned.  For now ...
3258      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3259      * can just let the other invalid results occur otherwise, as they have
3260      * until now.  For this one case, we can coerce.
3261      */
3262     if (y == -1 && x == LLONG_MIN && op != '*')
3263       {
3264       DEBUG(D_expand)
3265         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3266             LLONG_MIN, op, LLONG_MAX);
3267       x = LLONG_MAX;
3268       continue;
3269       }
3270     if (op == '*')
3271       x *= y;
3272     else
3273       {
3274       if (y == 0)
3275         {
3276         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3277         x = 0;
3278         break;
3279         }
3280       if (op == '/')
3281         x /= y;
3282       else
3283         x %= y;
3284       }
3285     }
3286   }
3287 *sptr = s;
3288 return x;
3289 }
3290
3291
3292 static int_eximarith_t
3293 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3294 {
3295 uschar *s = *sptr;
3296 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3297 if (*error == NULL)
3298   {
3299   while (*s == '+' || *s == '-')
3300     {
3301     int op = *s++;
3302     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3303     if (*error != NULL) break;
3304     if (op == '+') x += y; else x -= y;
3305     }
3306   }
3307 *sptr = s;
3308 return x;
3309 }
3310
3311
3312 static int_eximarith_t
3313 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3314 {
3315 uschar *s = *sptr;
3316 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3317 if (*error == NULL)
3318   {
3319   while ((*s == '<' || *s == '>') && s[1] == s[0])
3320     {
3321     int_eximarith_t y;
3322     int op = *s++;
3323     s++;
3324     y = eval_op_sum(&s, decimal, error);
3325     if (*error != NULL) break;
3326     if (op == '<') x <<= y; else x >>= y;
3327     }
3328   }
3329 *sptr = s;
3330 return x;
3331 }
3332
3333
3334 static int_eximarith_t
3335 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3336 {
3337 uschar *s = *sptr;
3338 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3339 if (*error == NULL)
3340   {
3341   while (*s == '&')
3342     {
3343     int_eximarith_t y;
3344     s++;
3345     y = eval_op_shift(&s, decimal, error);
3346     if (*error != NULL) break;
3347     x &= y;
3348     }
3349   }
3350 *sptr = s;
3351 return x;
3352 }
3353
3354
3355 static int_eximarith_t
3356 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3357 {
3358 uschar *s = *sptr;
3359 int_eximarith_t x = eval_op_and(&s, decimal, error);
3360 if (*error == NULL)
3361   {
3362   while (*s == '^')
3363     {
3364     int_eximarith_t y;
3365     s++;
3366     y = eval_op_and(&s, decimal, error);
3367     if (*error != NULL) break;
3368     x ^= y;
3369     }
3370   }
3371 *sptr = s;
3372 return x;
3373 }
3374
3375
3376 static int_eximarith_t
3377 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3378 {
3379 uschar *s = *sptr;
3380 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3381 if (*error == NULL)
3382   {
3383   while (*s == '|')
3384     {
3385     int_eximarith_t y;
3386     s++;
3387     y = eval_op_xor(&s, decimal, error);
3388     if (*error != NULL) break;
3389     x |= y;
3390     }
3391   }
3392 *sptr = s;
3393 return x;
3394 }
3395
3396
3397
3398 /*************************************************
3399 *                 Expand string                  *
3400 *************************************************/
3401
3402 /* Returns either an unchanged string, or the expanded string in stacking pool
3403 store. Interpreted sequences are:
3404
3405    \...                    normal escaping rules
3406    $name                   substitutes the variable
3407    ${name}                 ditto
3408    ${op:string}            operates on the expanded string value
3409    ${item{arg1}{arg2}...}  expands the args and then does the business
3410                              some literal args are not enclosed in {}
3411
3412 There are now far too many operators and item types to make it worth listing
3413 them here in detail any more.
3414
3415 We use an internal routine recursively to handle embedded substrings. The
3416 external function follows. The yield is NULL if the expansion failed, and there
3417 are two cases: if something collapsed syntactically, or if "fail" was given
3418 as the action on a lookup failure. These can be distinguised by looking at the
3419 variable expand_string_forcedfail, which is TRUE in the latter case.
3420
3421 The skipping flag is set true when expanding a substring that isn't actually
3422 going to be used (after "if" or "lookup") and it prevents lookups from
3423 happening lower down.
3424
3425 Store usage: At start, a store block of the length of the input plus 64
3426 is obtained. This is expanded as necessary by string_cat(), which might have to
3427 get a new block, or might be able to expand the original. At the end of the
3428 function we can release any store above that portion of the yield block that
3429 was actually used. In many cases this will be optimal.
3430
3431 However: if the first item in the expansion is a variable name or header name,
3432 we reset the store before processing it; if the result is in fresh store, we
3433 use that without copying. This is helpful for expanding strings like
3434 $message_headers which can get very long.
3435
3436 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3437 since resetting the store at the end of the expansion will free store that was
3438 allocated by the plugin code as well as the slop after the expanded string. So
3439 we skip any resets if ${dlfunc has been used. This is an unfortunate
3440 consequence of string expansion becoming too powerful.
3441
3442 Arguments:
3443   string         the string to be expanded
3444   ket_ends       true if expansion is to stop at }
3445   left           if not NULL, a pointer to the first character after the
3446                  expansion is placed here (typically used with ket_ends)
3447   skipping       TRUE for recursive calls when the value isn't actually going
3448                  to be used (to allow for optimisation)
3449   honour_dollar  TRUE if $ is to be expanded,
3450                  FALSE if it's just another character
3451
3452 Returns:         NULL if expansion fails:
3453                    expand_string_forcedfail is set TRUE if failure was forced
3454                    expand_string_message contains a textual error message
3455                  a pointer to the expanded string on success
3456 */
3457
3458 static uschar *
3459 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3460   BOOL skipping, BOOL honour_dollar)
3461 {
3462 int ptr = 0;
3463 int size = Ustrlen(string)+ 64;
3464 int item_type;
3465 uschar *yield = store_get(size);
3466 uschar *s = string;
3467 uschar *save_expand_nstring[EXPAND_MAXN+1];
3468 int save_expand_nlength[EXPAND_MAXN+1];
3469 BOOL resetok = TRUE;
3470
3471 expand_string_forcedfail = FALSE;
3472 expand_string_message = US"";
3473
3474 while (*s != 0)
3475   {
3476   uschar *value;
3477   uschar name[256];
3478
3479   /* \ escapes the next character, which must exist, or else
3480   the expansion fails. There's a special escape, \N, which causes
3481   copying of the subject verbatim up to the next \N. Otherwise,
3482   the escapes are the standard set. */
3483
3484   if (*s == '\\')
3485     {
3486     if (s[1] == 0)
3487       {
3488       expand_string_message = US"\\ at end of string";
3489       goto EXPAND_FAILED;
3490       }
3491
3492     if (s[1] == 'N')
3493       {
3494       uschar *t = s + 2;
3495       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3496       yield = string_cat(yield, &size, &ptr, t, s - t);
3497       if (*s != 0) s += 2;
3498       }
3499
3500     else
3501       {
3502       uschar ch[1];
3503       ch[0] = string_interpret_escape(&s);
3504       s++;
3505       yield = string_cat(yield, &size, &ptr, ch, 1);
3506       }
3507
3508     continue;
3509     }
3510
3511   /* Anything other than $ is just copied verbatim, unless we are
3512   looking for a terminating } character. */
3513
3514   if (ket_ends && *s == '}') break;
3515
3516   if (*s != '$' || !honour_dollar)
3517     {
3518     yield = string_cat(yield, &size, &ptr, s++, 1);
3519     continue;
3520     }
3521
3522   /* No { after the $ - must be a plain name or a number for string
3523   match variable. There has to be a fudge for variables that are the
3524   names of header fields preceded by "$header_" because header field
3525   names can contain any printing characters except space and colon.
3526   For those that don't like typing this much, "$h_" is a synonym for
3527   "$header_". A non-existent header yields a NULL value; nothing is
3528   inserted. */
3529
3530   if (isalpha((*(++s))))
3531     {
3532     int len;
3533     int newsize = 0;
3534
3535     s = read_name(name, sizeof(name), s, US"_");
3536
3537     /* If this is the first thing to be expanded, release the pre-allocated
3538     buffer. */
3539
3540     if (ptr == 0 && yield != NULL)
3541       {
3542       if (resetok) store_reset(yield);
3543       yield = NULL;
3544       size = 0;
3545       }
3546
3547     /* Header */
3548
3549     if (Ustrncmp(name, "h_", 2) == 0 ||
3550         Ustrncmp(name, "rh_", 3) == 0 ||
3551         Ustrncmp(name, "bh_", 3) == 0 ||
3552         Ustrncmp(name, "header_", 7) == 0 ||
3553         Ustrncmp(name, "rheader_", 8) == 0 ||
3554         Ustrncmp(name, "bheader_", 8) == 0)
3555       {
3556       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3557       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3558       s = read_header_name(name, sizeof(name), s);
3559       value = find_header(name, FALSE, &newsize, want_raw, charset);
3560
3561       /* If we didn't find the header, and the header contains a closing brace
3562       character, this may be a user error where the terminating colon
3563       has been omitted. Set a flag to adjust the error message in this case.
3564       But there is no error here - nothing gets inserted. */
3565
3566       if (value == NULL)
3567         {
3568         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3569         continue;
3570         }
3571       }
3572
3573     /* Variable */
3574
3575     else
3576       {
3577       value = find_variable(name, FALSE, skipping, &newsize);
3578       if (value == NULL)
3579         {
3580         expand_string_message =
3581           string_sprintf("unknown variable name \"%s\"", name);
3582           check_variable_error_message(name);
3583         goto EXPAND_FAILED;
3584         }
3585       }
3586
3587     /* If the data is known to be in a new buffer, newsize will be set to the
3588     size of that buffer. If this is the first thing in an expansion string,
3589     yield will be NULL; just point it at the new store instead of copying. Many
3590     expansion strings contain just one reference, so this is a useful
3591     optimization, especially for humungous headers. */
3592
3593     len = Ustrlen(value);
3594     if (yield == NULL && newsize != 0)
3595       {
3596       yield = value;
3597       size = newsize;
3598       ptr = len;
3599       }
3600     else yield = string_cat(yield, &size, &ptr, value, len);
3601
3602     continue;
3603     }
3604
3605   if (isdigit(*s))
3606     {
3607     int n;
3608     s = read_number(&n, s);
3609     if (n >= 0 && n <= expand_nmax)
3610       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3611         expand_nlength[n]);
3612     continue;
3613     }
3614
3615   /* Otherwise, if there's no '{' after $ it's an error. */
3616
3617   if (*s != '{')
3618     {
3619     expand_string_message = US"$ not followed by letter, digit, or {";
3620     goto EXPAND_FAILED;
3621     }
3622
3623   /* After { there can be various things, but they all start with
3624   an initial word, except for a number for a string match variable. */
3625
3626   if (isdigit((*(++s))))
3627     {
3628     int n;
3629     s = read_number(&n, s);
3630     if (*s++ != '}')
3631       {
3632       expand_string_message = US"} expected after number";
3633       goto EXPAND_FAILED;
3634       }
3635     if (n >= 0 && n <= expand_nmax)
3636       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3637         expand_nlength[n]);
3638     continue;
3639     }
3640
3641   if (!isalpha(*s))
3642     {
3643     expand_string_message = US"letter or digit expected after ${";
3644     goto EXPAND_FAILED;
3645     }
3646
3647   /* Allow "-" in names to cater for substrings with negative
3648   arguments. Since we are checking for known names after { this is
3649   OK. */
3650
3651   s = read_name(name, sizeof(name), s, US"_-");
3652   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3653
3654   switch(item_type)
3655     {
3656     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
3657     If the ACL returns acceptance we return content set by "message ="
3658     There is currently no limit on recursion; this would have us call
3659     acl_check_internal() directly and get a current level from somewhere.
3660     */
3661
3662     case EITEM_ACL:
3663       {
3664       int rc;
3665       uschar *sub[10];  /* name + arg1-arg9, must match number of acl_arg[] */
3666       uschar *new_yield;
3667       uschar *user_msg;
3668       uschar *log_msg;
3669       switch(read_subs(sub, 10, 1, &s, skipping, TRUE, US"acl"))
3670         {
3671         case 1: goto EXPAND_FAILED_CURLY;
3672         case 2:
3673         case 3: goto EXPAND_FAILED;
3674         }
3675       if (skipping) continue;
3676
3677       for (rc = 1; rc < sizeof(sub)/sizeof(*sub) && sub[rc]; rc++)
3678         acl_arg[rc-1] = sub[rc];
3679       acl_narg = rc-1;
3680       while (rc < sizeof(sub)/sizeof(*sub))
3681         acl_arg[rc++ - 1] = NULL;
3682
3683       DEBUG(D_expand)
3684         debug_printf("expanding: acl: %s  arg: %s%s\n",
3685           sub[0],
3686           acl_narg>0 ? sub[1]   : US"<none>",
3687           acl_narg>1 ? " +more" : "");
3688
3689       switch(rc = acl_check(ACL_WHERE_EXPANSION, NULL, sub[0], &user_msg, &log_msg))
3690         {
3691         case OK:
3692           if (user_msg)
3693             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
3694           continue;
3695         case DEFER:
3696           continue;
3697         default:
3698           expand_string_message = string_sprintf("acl \"%s\" did not accept", sub[0]);
3699           goto EXPAND_FAILED;
3700         }
3701       }
3702
3703     /* Handle conditionals - preserve the values of the numerical expansion
3704     variables in case they get changed by a regular expression match in the
3705     condition. If not, they retain their external settings. At the end
3706     of this "if" section, they get restored to their previous values. */
3707
3708     case EITEM_IF:
3709       {
3710       BOOL cond = FALSE;
3711       uschar *next_s;
3712       int save_expand_nmax =
3713         save_expand_strings(save_expand_nstring, save_expand_nlength);
3714
3715       while (isspace(*s)) s++;
3716       next_s = eval_condition(s, skipping? NULL : &cond);
3717       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3718
3719       DEBUG(D_expand)
3720         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3721           cond? "true" : "false");
3722
3723       s = next_s;
3724
3725       /* The handling of "yes" and "no" result strings is now in a separate
3726       function that is also used by ${lookup} and ${extract} and ${run}. */
3727
3728       switch(process_yesno(
3729                skipping,                     /* were previously skipping */
3730                cond,                         /* success/failure indicator */
3731                lookup_value,                 /* value to reset for string2 */
3732                &s,                           /* input pointer */
3733                &yield,                       /* output pointer */
3734                &size,                        /* output size */
3735                &ptr,                         /* output current point */
3736                US"if"))                      /* condition type */
3737         {
3738         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3739         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3740         }
3741
3742       /* Restore external setting of expansion variables for continuation
3743       at this level. */
3744
3745       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3746         save_expand_nlength);
3747       continue;
3748       }
3749
3750     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
3751     expanding an internal string that isn't actually going to be used. All we
3752     need to do is check the syntax, so don't do a lookup at all. Preserve the
3753     values of the numerical expansion variables in case they get changed by a
3754     partial lookup. If not, they retain their external settings. At the end
3755     of this "lookup" section, they get restored to their previous values. */
3756
3757     case EITEM_LOOKUP:
3758       {
3759       int stype, partial, affixlen, starflags;
3760       int expand_setup = 0;
3761       int nameptr = 0;
3762       uschar *key, *filename, *affix;
3763       uschar *save_lookup_value = lookup_value;
3764       int save_expand_nmax =
3765         save_expand_strings(save_expand_nstring, save_expand_nlength);
3766
3767       if ((expand_forbid & RDO_LOOKUP) != 0)
3768         {
3769         expand_string_message = US"lookup expansions are not permitted";
3770         goto EXPAND_FAILED;
3771         }
3772
3773       /* Get the key we are to look up for single-key+file style lookups.
3774       Otherwise set the key NULL pro-tem. */
3775
3776       while (isspace(*s)) s++;
3777       if (*s == '{')
3778         {
3779         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3780         if (key == NULL) goto EXPAND_FAILED;
3781         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3782         while (isspace(*s)) s++;
3783         }
3784       else key = NULL;
3785
3786       /* Find out the type of database */
3787
3788       if (!isalpha(*s))
3789         {
3790         expand_string_message = US"missing lookup type";
3791         goto EXPAND_FAILED;
3792         }
3793
3794       /* The type is a string that may contain special characters of various
3795       kinds. Allow everything except space or { to appear; the actual content
3796       is checked by search_findtype_partial. */
3797
3798       while (*s != 0 && *s != '{' && !isspace(*s))
3799         {
3800         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
3801         s++;
3802         }
3803       name[nameptr] = 0;
3804       while (isspace(*s)) s++;
3805
3806       /* Now check for the individual search type and any partial or default
3807       options. Only those types that are actually in the binary are valid. */
3808
3809       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
3810         &starflags);
3811       if (stype < 0)
3812         {
3813         expand_string_message = search_error_message;
3814         goto EXPAND_FAILED;
3815         }
3816
3817       /* Check that a key was provided for those lookup types that need it,
3818       and was not supplied for those that use the query style. */
3819
3820       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
3821         {
3822         if (key == NULL)
3823           {
3824           expand_string_message = string_sprintf("missing {key} for single-"
3825             "key \"%s\" lookup", name);
3826           goto EXPAND_FAILED;
3827           }
3828         }
3829       else
3830         {
3831         if (key != NULL)
3832           {
3833           expand_string_message = string_sprintf("a single key was given for "
3834             "lookup type \"%s\", which is not a single-key lookup type", name);
3835           goto EXPAND_FAILED;
3836           }
3837         }
3838
3839       /* Get the next string in brackets and expand it. It is the file name for
3840       single-key+file lookups, and the whole query otherwise. In the case of
3841       queries that also require a file name (e.g. sqlite), the file name comes
3842       first. */
3843
3844       if (*s != '{') goto EXPAND_FAILED_CURLY;
3845       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3846       if (filename == NULL) goto EXPAND_FAILED;
3847       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3848       while (isspace(*s)) s++;
3849
3850       /* If this isn't a single-key+file lookup, re-arrange the variables
3851       to be appropriate for the search_ functions. For query-style lookups,
3852       there is just a "key", and no file name. For the special query-style +
3853       file types, the query (i.e. "key") starts with a file name. */
3854
3855       if (key == NULL)
3856         {
3857         while (isspace(*filename)) filename++;
3858         key = filename;
3859
3860         if (mac_islookup(stype, lookup_querystyle))
3861           {
3862           filename = NULL;
3863           }
3864         else
3865           {
3866           if (*filename != '/')
3867             {
3868             expand_string_message = string_sprintf(
3869               "absolute file name expected for \"%s\" lookup", name);
3870             goto EXPAND_FAILED;
3871             }
3872           while (*key != 0 && !isspace(*key)) key++;
3873           if (*key != 0) *key++ = 0;
3874           }
3875         }
3876
3877       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
3878       the entry was not found. Note that there is no search_close() function.
3879       Files are left open in case of re-use. At suitable places in higher logic,
3880       search_tidyup() is called to tidy all open files. This can save opening
3881       the same file several times. However, files may also get closed when
3882       others are opened, if too many are open at once. The rule is that a
3883       handle should not be used after a second search_open().
3884
3885       Request that a partial search sets up $1 and maybe $2 by passing
3886       expand_setup containing zero. If its value changes, reset expand_nmax,
3887       since new variables will have been set. Note that at the end of this
3888       "lookup" section, the old numeric variables are restored. */
3889
3890       if (skipping)
3891         lookup_value = NULL;
3892       else
3893         {
3894         void *handle = search_open(filename, stype, 0, NULL, NULL);
3895         if (handle == NULL)
3896           {
3897           expand_string_message = search_error_message;
3898           goto EXPAND_FAILED;
3899           }
3900         lookup_value = search_find(handle, filename, key, partial, affix,
3901           affixlen, starflags, &expand_setup);
3902         if (search_find_defer)
3903           {
3904           expand_string_message =
3905             string_sprintf("lookup of \"%s\" gave DEFER: %s",
3906               string_printing2(key, FALSE), search_error_message);
3907           goto EXPAND_FAILED;
3908           }
3909         if (expand_setup > 0) expand_nmax = expand_setup;
3910         }
3911
3912       /* The handling of "yes" and "no" result strings is now in a separate
3913       function that is also used by ${if} and ${extract}. */
3914
3915       switch(process_yesno(
3916                skipping,                     /* were previously skipping */
3917                lookup_value != NULL,         /* success/failure indicator */
3918                save_lookup_value,            /* value to reset for string2 */
3919                &s,                           /* input pointer */
3920                &yield,                       /* output pointer */
3921                &size,                        /* output size */
3922                &ptr,                         /* output current point */
3923                US"lookup"))                  /* condition type */
3924         {
3925         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3926         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3927         }
3928
3929       /* Restore external setting of expansion variables for carrying on
3930       at this level, and continue. */
3931
3932       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3933         save_expand_nlength);
3934       continue;
3935       }
3936
3937     /* If Perl support is configured, handle calling embedded perl subroutines,
3938     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
3939     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
3940     arguments (defined below). */
3941
3942     #define EXIM_PERL_MAX_ARGS 8
3943
3944     case EITEM_PERL:
3945     #ifndef EXIM_PERL
3946     expand_string_message = US"\"${perl\" encountered, but this facility "
3947       "is not included in this binary";
3948     goto EXPAND_FAILED;
3949
3950     #else   /* EXIM_PERL */
3951       {
3952       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
3953       uschar *new_yield;
3954
3955       if ((expand_forbid & RDO_PERL) != 0)
3956         {
3957         expand_string_message = US"Perl calls are not permitted";
3958         goto EXPAND_FAILED;
3959         }
3960
3961       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
3962            US"perl"))
3963         {
3964         case 1: goto EXPAND_FAILED_CURLY;
3965         case 2:
3966         case 3: goto EXPAND_FAILED;
3967         }
3968
3969       /* If skipping, we don't actually do anything */
3970
3971       if (skipping) continue;
3972
3973       /* Start the interpreter if necessary */
3974
3975       if (!opt_perl_started)
3976         {
3977         uschar *initerror;
3978         if (opt_perl_startup == NULL)
3979           {
3980           expand_string_message = US"A setting of perl_startup is needed when "
3981             "using the Perl interpreter";
3982           goto EXPAND_FAILED;
3983           }
3984         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
3985         initerror = init_perl(opt_perl_startup);
3986         if (initerror != NULL)
3987           {
3988           expand_string_message =
3989             string_sprintf("error in perl_startup code: %s\n", initerror);
3990           goto EXPAND_FAILED;
3991           }
3992         opt_perl_started = TRUE;
3993         }
3994
3995       /* Call the function */
3996
3997       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
3998       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
3999         sub_arg[0], sub_arg + 1);
4000
4001       /* NULL yield indicates failure; if the message pointer has been set to
4002       NULL, the yield was undef, indicating a forced failure. Otherwise the
4003       message will indicate some kind of Perl error. */
4004
4005       if (new_yield == NULL)
4006         {
4007         if (expand_string_message == NULL)
4008           {
4009           expand_string_message =
4010             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4011               "failure", sub_arg[0]);
4012           expand_string_forcedfail = TRUE;
4013           }
4014         goto EXPAND_FAILED;
4015         }
4016
4017       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4018       set during a callback from Perl. */
4019
4020       expand_string_forcedfail = FALSE;
4021       yield = new_yield;
4022       continue;
4023       }
4024     #endif /* EXIM_PERL */
4025
4026     /* Transform email address to "prvs" scheme to use
4027        as BATV-signed return path */
4028
4029     case EITEM_PRVS:
4030       {
4031       uschar *sub_arg[3];
4032       uschar *p,*domain;
4033
4034       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs"))
4035         {
4036         case 1: goto EXPAND_FAILED_CURLY;
4037         case 2:
4038         case 3: goto EXPAND_FAILED;
4039         }
4040
4041       /* If skipping, we don't actually do anything */
4042       if (skipping) continue;
4043
4044       /* sub_arg[0] is the address */
4045       domain = Ustrrchr(sub_arg[0],'@');
4046       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4047         {
4048         expand_string_message = US"prvs first argument must be a qualified email address";
4049         goto EXPAND_FAILED;
4050         }
4051
4052       /* Calculate the hash. The second argument must be a single-digit
4053       key number, or unset. */
4054
4055       if (sub_arg[2] != NULL &&
4056           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4057         {
4058         expand_string_message = US"prvs second argument must be a single digit";
4059         goto EXPAND_FAILED;
4060         }
4061
4062       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4063       if (p == NULL)
4064         {
4065         expand_string_message = US"prvs hmac-sha1 conversion failed";
4066         goto EXPAND_FAILED;
4067         }
4068
4069       /* Now separate the domain from the local part */
4070       *domain++ = '\0';
4071
4072       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4073       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4074       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4075       string_cat(yield,&size,&ptr,p,6);
4076       string_cat(yield,&size,&ptr,US"=",1);
4077       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4078       string_cat(yield,&size,&ptr,US"@",1);
4079       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4080
4081       continue;
4082       }
4083
4084     /* Check a prvs-encoded address for validity */
4085
4086     case EITEM_PRVSCHECK:
4087       {
4088       uschar *sub_arg[3];
4089       int mysize = 0, myptr = 0;
4090       const pcre *re;
4091       uschar *p;
4092
4093       /* TF: Ugliness: We want to expand parameter 1 first, then set
4094          up expansion variables that are used in the expansion of
4095          parameter 2. So we clone the string for the first
4096          expansion, where we only expand parameter 1.
4097
4098          PH: Actually, that isn't necessary. The read_subs() function is
4099          designed to work this way for the ${if and ${lookup expansions. I've
4100          tidied the code.
4101       */
4102
4103       /* Reset expansion variables */
4104       prvscheck_result = NULL;
4105       prvscheck_address = NULL;
4106       prvscheck_keynum = NULL;
4107
4108       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4109         {
4110         case 1: goto EXPAND_FAILED_CURLY;
4111         case 2:
4112         case 3: goto EXPAND_FAILED;
4113         }
4114
4115       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4116                               TRUE,FALSE);
4117
4118       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4119         {
4120         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4121         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4122         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4123         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4124         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4125
4126         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4127         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4128         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4129         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4130         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4131
4132         /* Set up expansion variables */
4133         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4134         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4135         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4136         prvscheck_address[myptr] = '\0';
4137         prvscheck_keynum = string_copy(key_num);
4138
4139         /* Now expand the second argument */
4140         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4141           {
4142           case 1: goto EXPAND_FAILED_CURLY;
4143           case 2:
4144           case 3: goto EXPAND_FAILED;
4145           }
4146
4147         /* Now we have the key and can check the address. */
4148
4149         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4150           daystamp);
4151
4152         if (p == NULL)
4153           {
4154           expand_string_message = US"hmac-sha1 conversion failed";
4155           goto EXPAND_FAILED;
4156           }
4157
4158         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4159         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4160
4161         if (Ustrcmp(p,hash) == 0)
4162           {
4163           /* Success, valid BATV address. Now check the expiry date. */
4164           uschar *now = prvs_daystamp(0);
4165           unsigned int inow = 0,iexpire = 1;
4166
4167           (void)sscanf(CS now,"%u",&inow);
4168           (void)sscanf(CS daystamp,"%u",&iexpire);
4169
4170           /* When "iexpire" is < 7, a "flip" has occured.
4171              Adjust "inow" accordingly. */
4172           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4173
4174           if (iexpire >= inow)
4175             {
4176             prvscheck_result = US"1";
4177             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4178             }
4179             else
4180             {
4181             prvscheck_result = NULL;
4182             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4183             }
4184           }
4185         else
4186           {
4187           prvscheck_result = NULL;
4188           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4189           }
4190
4191         /* Now expand the final argument. We leave this till now so that
4192         it can include $prvscheck_result. */
4193
4194         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs"))
4195           {
4196           case 1: goto EXPAND_FAILED_CURLY;
4197           case 2:
4198           case 3: goto EXPAND_FAILED;
4199           }
4200
4201         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4202           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4203         else
4204           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4205
4206         /* Reset the "internal" variables afterwards, because they are in
4207         dynamic store that will be reclaimed if the expansion succeeded. */
4208
4209         prvscheck_address = NULL;
4210         prvscheck_keynum = NULL;
4211         }
4212       else
4213         {
4214         /* Does not look like a prvs encoded address, return the empty string.
4215            We need to make sure all subs are expanded first, so as to skip over
4216            the entire item. */
4217
4218         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs"))
4219           {
4220           case 1: goto EXPAND_FAILED_CURLY;
4221           case 2:
4222           case 3: goto EXPAND_FAILED;
4223           }
4224         }
4225
4226       continue;
4227       }
4228
4229     /* Handle "readfile" to insert an entire file */
4230
4231     case EITEM_READFILE:
4232       {
4233       FILE *f;
4234       uschar *sub_arg[2];
4235
4236       if ((expand_forbid & RDO_READFILE) != 0)
4237         {
4238         expand_string_message = US"file insertions are not permitted";
4239         goto EXPAND_FAILED;
4240         }
4241
4242       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
4243         {
4244         case 1: goto EXPAND_FAILED_CURLY;
4245         case 2:
4246         case 3: goto EXPAND_FAILED;
4247         }
4248
4249       /* If skipping, we don't actually do anything */
4250
4251       if (skipping) continue;
4252
4253       /* Open the file and read it */
4254
4255       f = Ufopen(sub_arg[0], "rb");
4256       if (f == NULL)
4257         {
4258         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4259         goto EXPAND_FAILED;
4260         }
4261
4262       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4263       (void)fclose(f);
4264       continue;
4265       }
4266
4267     /* Handle "readsocket" to insert data from a Unix domain socket */
4268
4269     case EITEM_READSOCK:
4270       {
4271       int fd;
4272       int timeout = 5;
4273       int save_ptr = ptr;
4274       FILE *f;
4275       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4276       uschar *arg;
4277       uschar *sub_arg[4];
4278
4279       if ((expand_forbid & RDO_READSOCK) != 0)
4280         {
4281         expand_string_message = US"socket insertions are not permitted";
4282         goto EXPAND_FAILED;
4283         }
4284
4285       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4286       because there may be a string for expansion on failure. */
4287
4288       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
4289         {
4290         case 1: goto EXPAND_FAILED_CURLY;
4291         case 2:                             /* Won't occur: no end check */
4292         case 3: goto EXPAND_FAILED;
4293         }
4294
4295       /* Sort out timeout, if given */
4296
4297       if (sub_arg[2] != NULL)
4298         {
4299         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4300         if (timeout < 0)
4301           {
4302           expand_string_message = string_sprintf("bad time value %s",
4303             sub_arg[2]);
4304           goto EXPAND_FAILED;
4305           }
4306         }
4307       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4308
4309       /* If skipping, we don't actually do anything. Otherwise, arrange to
4310       connect to either an IP or a Unix socket. */
4311
4312       if (!skipping)
4313         {
4314         /* Handle an IP (internet) domain */
4315
4316         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4317           {
4318           BOOL connected = FALSE;
4319           int namelen, port;
4320           host_item shost;
4321           host_item *h;
4322           uschar *server_name = sub_arg[0] + 5;
4323           uschar *port_name = Ustrrchr(server_name, ':');
4324
4325           /* Sort out the port */
4326
4327           if (port_name == NULL)
4328             {
4329             expand_string_message =
4330               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4331             goto EXPAND_FAILED;
4332             }
4333           *port_name++ = 0;           /* Terminate server name */
4334
4335           if (isdigit(*port_name))
4336             {
4337             uschar *end;
4338             port = Ustrtol(port_name, &end, 0);
4339             if (end != port_name + Ustrlen(port_name))
4340               {
4341               expand_string_message =
4342                 string_sprintf("invalid port number %s", port_name);
4343               goto EXPAND_FAILED;
4344               }
4345             }
4346           else
4347             {
4348             struct servent *service_info = getservbyname(CS port_name, "tcp");
4349             if (service_info == NULL)
4350               {
4351               expand_string_message = string_sprintf("unknown port \"%s\"",
4352                 port_name);
4353               goto EXPAND_FAILED;
4354               }
4355             port = ntohs(service_info->s_port);
4356             }
4357
4358           /* Sort out the server. */
4359
4360           shost.next = NULL;
4361           shost.address = NULL;
4362           shost.port = port;
4363           shost.mx = -1;
4364
4365           namelen = Ustrlen(server_name);
4366
4367           /* Anything enclosed in [] must be an IP address. */
4368
4369           if (server_name[0] == '[' &&
4370               server_name[namelen - 1] == ']')
4371             {
4372             server_name[namelen - 1] = 0;
4373             server_name++;
4374             if (string_is_ip_address(server_name, NULL) == 0)
4375               {
4376               expand_string_message =
4377                 string_sprintf("malformed IP address \"%s\"", server_name);
4378               goto EXPAND_FAILED;
4379               }
4380             shost.name = shost.address = server_name;
4381             }
4382
4383           /* Otherwise check for an unadorned IP address */
4384
4385           else if (string_is_ip_address(server_name, NULL) != 0)
4386             shost.name = shost.address = server_name;
4387
4388           /* Otherwise lookup IP address(es) from the name */
4389
4390           else
4391             {
4392             shost.name = server_name;
4393             if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
4394                 FALSE) != HOST_FOUND)
4395               {
4396               expand_string_message =
4397                 string_sprintf("no IP address found for host %s", shost.name);
4398               goto EXPAND_FAILED;
4399               }
4400             }
4401
4402           /* Try to connect to the server - test each IP till one works */
4403
4404           for (h = &shost; h != NULL; h = h->next)
4405             {
4406             int af = (Ustrchr(h->address, ':') != 0)? AF_INET6 : AF_INET;
4407             if ((fd = ip_socket(SOCK_STREAM, af)) == -1)
4408               {
4409               expand_string_message = string_sprintf("failed to create socket: "
4410                 "%s", strerror(errno));
4411               goto SOCK_FAIL;
4412               }
4413
4414             if (ip_connect(fd, af, h->address, port, timeout) == 0)
4415               {
4416               connected = TRUE;
4417               break;
4418               }
4419             }
4420
4421           if (!connected)
4422             {
4423             expand_string_message = string_sprintf("failed to connect to "
4424               "socket %s: couldn't connect to any host", sub_arg[0],
4425               strerror(errno));
4426             goto SOCK_FAIL;
4427             }
4428           }
4429
4430         /* Handle a Unix domain socket */
4431
4432         else
4433           {
4434           int rc;
4435           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4436             {
4437             expand_string_message = string_sprintf("failed to create socket: %s",
4438               strerror(errno));
4439             goto SOCK_FAIL;
4440             }
4441
4442           sockun.sun_family = AF_UNIX;
4443           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4444             sub_arg[0]);
4445
4446           sigalrm_seen = FALSE;
4447           alarm(timeout);
4448           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4449           alarm(0);
4450           if (sigalrm_seen)
4451             {
4452             expand_string_message = US "socket connect timed out";
4453             goto SOCK_FAIL;
4454             }
4455           if (rc < 0)
4456             {
4457             expand_string_message = string_sprintf("failed to connect to socket "
4458               "%s: %s", sub_arg[0], strerror(errno));
4459             goto SOCK_FAIL;
4460             }
4461           }
4462
4463         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4464
4465         /* Write the request string, if not empty */
4466
4467         if (sub_arg[1][0] != 0)
4468           {
4469           int len = Ustrlen(sub_arg[1]);
4470           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4471             sub_arg[1]);
4472           if (write(fd, sub_arg[1], len) != len)
4473             {
4474             expand_string_message = string_sprintf("request write to socket "
4475               "failed: %s", strerror(errno));
4476             goto SOCK_FAIL;
4477             }
4478           }
4479
4480         /* Shut down the sending side of the socket. This helps some servers to
4481         recognise that it is their turn to do some work. Just in case some
4482         system doesn't have this function, make it conditional. */
4483
4484         #ifdef SHUT_WR
4485         shutdown(fd, SHUT_WR);
4486         #endif
4487
4488         /* Now we need to read from the socket, under a timeout. The function
4489         that reads a file can be used. */
4490
4491         f = fdopen(fd, "rb");
4492         sigalrm_seen = FALSE;
4493         alarm(timeout);
4494         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4495         alarm(0);
4496         (void)fclose(f);
4497
4498         /* After a timeout, we restore the pointer in the result, that is,
4499         make sure we add nothing from the socket. */
4500
4501         if (sigalrm_seen)
4502           {
4503           ptr = save_ptr;
4504           expand_string_message = US "socket read timed out";
4505           goto SOCK_FAIL;
4506           }
4507         }
4508
4509       /* The whole thing has worked (or we were skipping). If there is a
4510       failure string following, we need to skip it. */
4511
4512       if (*s == '{')
4513         {
4514         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE) == NULL)
4515           goto EXPAND_FAILED;
4516         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4517         while (isspace(*s)) s++;
4518         }
4519       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4520       continue;
4521
4522       /* Come here on failure to create socket, connect socket, write to the
4523       socket, or timeout on reading. If another substring follows, expand and
4524       use it. Otherwise, those conditions give expand errors. */
4525
4526       SOCK_FAIL:
4527       if (*s != '{') goto EXPAND_FAILED;
4528       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4529       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE);
4530       if (arg == NULL) goto EXPAND_FAILED;
4531       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4532       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4533       while (isspace(*s)) s++;
4534       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4535       continue;
4536       }
4537
4538     /* Handle "run" to execute a program. */
4539
4540     case EITEM_RUN:
4541       {
4542       FILE *f;
4543       uschar *arg;
4544       uschar **argv;
4545       pid_t pid;
4546       int fd_in, fd_out;
4547       int lsize = 0;
4548       int lptr = 0;
4549
4550       if ((expand_forbid & RDO_RUN) != 0)
4551         {
4552         expand_string_message = US"running a command is not permitted";
4553         goto EXPAND_FAILED;
4554         }
4555
4556       while (isspace(*s)) s++;
4557       if (*s != '{') goto EXPAND_FAILED_CURLY;
4558       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
4559       if (arg == NULL) goto EXPAND_FAILED;
4560       while (isspace(*s)) s++;
4561       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4562
4563       if (skipping)   /* Just pretend it worked when we're skipping */
4564         {
4565         runrc = 0;
4566         }
4567       else
4568         {
4569         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4570             arg,                                /* raw command */
4571             FALSE,                              /* don't expand the arguments */
4572             0,                                  /* not relevant when... */
4573             NULL,                               /* no transporting address */
4574             US"${run} expansion",               /* for error messages */
4575             &expand_string_message))            /* where to put error message */
4576           {
4577           goto EXPAND_FAILED;
4578           }
4579
4580         /* Create the child process, making it a group leader. */
4581
4582         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4583
4584         if (pid < 0)
4585           {
4586           expand_string_message =
4587             string_sprintf("couldn't create child process: %s", strerror(errno));
4588           goto EXPAND_FAILED;
4589           }
4590
4591         /* Nothing is written to the standard input. */
4592
4593         (void)close(fd_in);
4594
4595         /* Read the pipe to get the command's output into $value (which is kept
4596         in lookup_value). Read during execution, so that if the output exceeds
4597         the OS pipe buffer limit, we don't block forever. */
4598
4599         f = fdopen(fd_out, "rb");
4600         sigalrm_seen = FALSE;
4601         alarm(60);
4602         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4603         alarm(0);
4604         (void)fclose(f);
4605
4606         /* Wait for the process to finish, applying the timeout, and inspect its
4607         return code for serious disasters. Simple non-zero returns are passed on.
4608         */
4609
4610         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4611           {
4612           if (sigalrm_seen == TRUE || runrc == -256)
4613             {
4614             expand_string_message = string_sprintf("command timed out");
4615             killpg(pid, SIGKILL);       /* Kill the whole process group */
4616             }
4617
4618           else if (runrc == -257)
4619             expand_string_message = string_sprintf("wait() failed: %s",
4620               strerror(errno));
4621
4622           else
4623             expand_string_message = string_sprintf("command killed by signal %d",
4624               -runrc);
4625
4626           goto EXPAND_FAILED;
4627           }
4628         }
4629
4630       /* Process the yes/no strings; $value may be useful in both cases */
4631
4632       switch(process_yesno(
4633                skipping,                     /* were previously skipping */
4634                runrc == 0,                   /* success/failure indicator */
4635                lookup_value,                 /* value to reset for string2 */
4636                &s,                           /* input pointer */
4637                &yield,                       /* output pointer */
4638                &size,                        /* output size */
4639                &ptr,                         /* output current point */
4640                US"run"))                     /* condition type */
4641         {
4642         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4643         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4644         }
4645
4646       continue;
4647       }
4648
4649     /* Handle character translation for "tr" */
4650
4651     case EITEM_TR:
4652       {
4653       int oldptr = ptr;
4654       int o2m;
4655       uschar *sub[3];
4656
4657       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
4658         {
4659         case 1: goto EXPAND_FAILED_CURLY;
4660         case 2:
4661         case 3: goto EXPAND_FAILED;
4662         }
4663
4664       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4665       o2m = Ustrlen(sub[2]) - 1;
4666
4667       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4668         {
4669         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4670         if (m != NULL)
4671           {
4672           int o = m - sub[1];
4673           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4674           }
4675         }
4676
4677       continue;
4678       }
4679
4680     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4681     expanded arguments. */
4682
4683     case EITEM_HASH:
4684     case EITEM_LENGTH:
4685     case EITEM_NHASH:
4686     case EITEM_SUBSTR:
4687       {
4688       int i;
4689       int len;
4690       uschar *ret;
4691       int val[2] = { 0, -1 };
4692       uschar *sub[3];
4693
4694       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4695       Ensure that sub[2] is set in the ${length case. */
4696
4697       sub[2] = NULL;
4698       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4699              TRUE, name))
4700         {
4701         case 1: goto EXPAND_FAILED_CURLY;
4702         case 2:
4703         case 3: goto EXPAND_FAILED;
4704         }
4705
4706       /* Juggle the arguments if there are only two of them: always move the
4707       string to the last position and make ${length{n}{str}} equivalent to
4708       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4709
4710       if (sub[2] == NULL)
4711         {
4712         sub[2] = sub[1];
4713         sub[1] = NULL;
4714         if (item_type == EITEM_LENGTH)
4715           {
4716           sub[1] = sub[0];
4717           sub[0] = NULL;
4718           }
4719         }
4720
4721       for (i = 0; i < 2; i++)
4722         {
4723         if (sub[i] == NULL) continue;
4724         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4725         if (*ret != 0 || (i != 0 && val[i] < 0))
4726           {
4727           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4728             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4729           goto EXPAND_FAILED;
4730           }
4731         }
4732
4733       ret =
4734         (item_type == EITEM_HASH)?
4735           compute_hash(sub[2], val[0], val[1], &len) :
4736         (item_type == EITEM_NHASH)?
4737           compute_nhash(sub[2], val[0], val[1], &len) :
4738           extract_substr(sub[2], val[0], val[1], &len);
4739
4740       if (ret == NULL) goto EXPAND_FAILED;
4741       yield = string_cat(yield, &size, &ptr, ret, len);
4742       continue;
4743       }
4744
4745     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4746     This code originally contributed by Steve Haslam. It currently supports
4747     the use of MD5 and SHA-1 hashes.
4748
4749     We need some workspace that is large enough to handle all the supported
4750     hash types. Use macros to set the sizes rather than be too elaborate. */
4751
4752     #define MAX_HASHLEN      20
4753     #define MAX_HASHBLOCKLEN 64
4754
4755     case EITEM_HMAC:
4756       {
4757       uschar *sub[3];
4758       md5 md5_base;
4759       sha1 sha1_base;
4760       void *use_base;
4761       int type, i;
4762       int hashlen;      /* Number of octets for the hash algorithm's output */
4763       int hashblocklen; /* Number of octets the hash algorithm processes */
4764       uschar *keyptr, *p;
4765       unsigned int keylen;
4766
4767       uschar keyhash[MAX_HASHLEN];
4768       uschar innerhash[MAX_HASHLEN];
4769       uschar finalhash[MAX_HASHLEN];
4770       uschar finalhash_hex[2*MAX_HASHLEN];
4771       uschar innerkey[MAX_HASHBLOCKLEN];
4772       uschar outerkey[MAX_HASHBLOCKLEN];
4773
4774       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
4775         {
4776         case 1: goto EXPAND_FAILED_CURLY;
4777         case 2:
4778         case 3: goto EXPAND_FAILED;
4779         }
4780
4781       if (Ustrcmp(sub[0], "md5") == 0)
4782         {
4783         type = HMAC_MD5;
4784         use_base = &md5_base;
4785         hashlen = 16;
4786         hashblocklen = 64;
4787         }
4788       else if (Ustrcmp(sub[0], "sha1") == 0)
4789         {
4790         type = HMAC_SHA1;
4791         use_base = &sha1_base;
4792         hashlen = 20;
4793         hashblocklen = 64;
4794         }
4795       else
4796         {
4797         expand_string_message =
4798           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
4799         goto EXPAND_FAILED;
4800         }
4801
4802       keyptr = sub[1];
4803       keylen = Ustrlen(keyptr);
4804
4805       /* If the key is longer than the hash block length, then hash the key
4806       first */
4807
4808       if (keylen > hashblocklen)
4809         {
4810         chash_start(type, use_base);
4811         chash_end(type, use_base, keyptr, keylen, keyhash);
4812         keyptr = keyhash;
4813         keylen = hashlen;
4814         }
4815
4816       /* Now make the inner and outer key values */
4817
4818       memset(innerkey, 0x36, hashblocklen);
4819       memset(outerkey, 0x5c, hashblocklen);
4820
4821       for (i = 0; i < keylen; i++)
4822         {
4823         innerkey[i] ^= keyptr[i];
4824         outerkey[i] ^= keyptr[i];
4825         }
4826
4827       /* Now do the hashes */
4828
4829       chash_start(type, use_base);
4830       chash_mid(type, use_base, innerkey);
4831       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
4832
4833       chash_start(type, use_base);
4834       chash_mid(type, use_base, outerkey);
4835       chash_end(type, use_base, innerhash, hashlen, finalhash);
4836
4837       /* Encode the final hash as a hex string */
4838
4839       p = finalhash_hex;
4840       for (i = 0; i < hashlen; i++)
4841         {
4842         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
4843         *p++ = hex_digits[finalhash[i] & 0x0f];
4844         }
4845
4846       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
4847         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
4848
4849       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
4850       }
4851
4852     continue;
4853
4854     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
4855     We have to save the numerical variables and restore them afterwards. */
4856
4857     case EITEM_SG:
4858       {
4859       const pcre *re;
4860       int moffset, moffsetextra, slen;
4861       int roffset;
4862       int emptyopt;
4863       const uschar *rerror;
4864       uschar *subject;
4865       uschar *sub[3];
4866       int save_expand_nmax =
4867         save_expand_strings(save_expand_nstring, save_expand_nlength);
4868
4869       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
4870         {
4871         case 1: goto EXPAND_FAILED_CURLY;
4872         case 2:
4873         case 3: goto EXPAND_FAILED;
4874         }
4875
4876       /* Compile the regular expression */
4877
4878       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
4879         NULL);
4880
4881       if (re == NULL)
4882         {
4883         expand_string_message = string_sprintf("regular expression error in "
4884           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
4885         goto EXPAND_FAILED;
4886         }
4887
4888       /* Now run a loop to do the substitutions as often as necessary. It ends
4889       when there are no more matches. Take care over matches of the null string;
4890       do the same thing as Perl does. */
4891
4892       subject = sub[0];
4893       slen = Ustrlen(sub[0]);
4894       moffset = moffsetextra = 0;
4895       emptyopt = 0;
4896
4897       for (;;)
4898         {
4899         int ovector[3*(EXPAND_MAXN+1)];
4900         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
4901           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
4902         int nn;
4903         uschar *insert;
4904
4905         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
4906         is not necessarily the end. We want to repeat the match from one
4907         character further along, but leaving the basic offset the same (for
4908         copying below). We can't be at the end of the string - that was checked
4909         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
4910         finished; copy the remaining string and end the loop. */
4911
4912         if (n < 0)
4913           {
4914           if (emptyopt != 0)
4915             {
4916             moffsetextra = 1;
4917             emptyopt = 0;
4918             continue;
4919             }
4920           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
4921           break;
4922           }
4923
4924         /* Match - set up for expanding the replacement. */
4925
4926         if (n == 0) n = EXPAND_MAXN + 1;
4927         expand_nmax = 0;
4928         for (nn = 0; nn < n*2; nn += 2)
4929           {
4930           expand_nstring[expand_nmax] = subject + ovector[nn];
4931           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
4932           }
4933         expand_nmax--;
4934
4935         /* Copy the characters before the match, plus the expanded insertion. */
4936
4937         yield = string_cat(yield, &size, &ptr, subject + moffset,
4938           ovector[0] - moffset);
4939         insert = expand_string(sub[2]);
4940         if (insert == NULL) goto EXPAND_FAILED;
4941         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
4942
4943         moffset = ovector[1];
4944         moffsetextra = 0;
4945         emptyopt = 0;
4946
4947         /* If we have matched an empty string, first check to see if we are at
4948         the end of the subject. If so, the loop is over. Otherwise, mimic
4949         what Perl's /g options does. This turns out to be rather cunning. First
4950         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
4951         string at the same point. If this fails (picked up above) we advance to
4952         the next character. */
4953
4954         if (ovector[0] == ovector[1])
4955           {
4956           if (ovector[0] == slen) break;
4957           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
4958           }
4959         }
4960
4961       /* All done - restore numerical variables. */
4962
4963       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4964         save_expand_nlength);
4965       continue;
4966       }
4967
4968     /* Handle keyed and numbered substring extraction. If the first argument
4969     consists entirely of digits, then a numerical extraction is assumed. */
4970
4971     case EITEM_EXTRACT:
4972       {
4973       int i;
4974       int j = 2;
4975       int field_number = 1;
4976       BOOL field_number_set = FALSE;
4977       uschar *save_lookup_value = lookup_value;
4978       uschar *sub[3];
4979       int save_expand_nmax =
4980         save_expand_strings(save_expand_nstring, save_expand_nlength);
4981
4982       /* Read the arguments */
4983
4984       for (i = 0; i < j; i++)
4985         {
4986         while (isspace(*s)) s++;
4987         if (*s == '{')
4988           {
4989           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
4990           if (sub[i] == NULL) goto EXPAND_FAILED;
4991           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4992
4993           /* After removal of leading and trailing white space, the first
4994           argument must not be empty; if it consists entirely of digits
4995           (optionally preceded by a minus sign), this is a numerical
4996           extraction, and we expect 3 arguments. */
4997
4998           if (i == 0)
4999             {
5000             int len;
5001             int x = 0;
5002             uschar *p = sub[0];
5003
5004             while (isspace(*p)) p++;
5005             sub[0] = p;
5006
5007             len = Ustrlen(p);
5008             while (len > 0 && isspace(p[len-1])) len--;
5009             p[len] = 0;
5010
5011             if (*p == 0 && !skipping)
5012               {
5013               expand_string_message = US"first argument of \"extract\" must "
5014                 "not be empty";
5015               goto EXPAND_FAILED;
5016               }
5017
5018             if (*p == '-')
5019               {
5020               field_number = -1;
5021               p++;
5022               }
5023             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5024             if (*p == 0)
5025               {
5026               field_number *= x;
5027               j = 3;               /* Need 3 args */
5028               field_number_set = TRUE;
5029               }
5030             }
5031           }
5032         else goto EXPAND_FAILED_CURLY;
5033         }
5034
5035       /* Extract either the numbered or the keyed substring into $value. If
5036       skipping, just pretend the extraction failed. */
5037
5038       lookup_value = skipping? NULL : field_number_set?
5039         expand_gettokened(field_number, sub[1], sub[2]) :
5040         expand_getkeyed(sub[0], sub[1]);
5041
5042       /* If no string follows, $value gets substituted; otherwise there can
5043       be yes/no strings, as for lookup or if. */
5044
5045       switch(process_yesno(
5046                skipping,                     /* were previously skipping */
5047                lookup_value != NULL,         /* success/failure indicator */
5048                save_lookup_value,            /* value to reset for string2 */
5049                &s,                           /* input pointer */
5050                &yield,                       /* output pointer */
5051                &size,                        /* output size */
5052                &ptr,                         /* output current point */
5053                US"extract"))                 /* condition type */
5054         {
5055         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5056         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5057         }
5058
5059       /* All done - restore numerical variables. */
5060
5061       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5062         save_expand_nlength);
5063
5064       continue;
5065       }
5066
5067
5068     /* Handle list operations */
5069
5070     case EITEM_FILTER:
5071     case EITEM_MAP:
5072     case EITEM_REDUCE:
5073       {
5074       int sep = 0;
5075       int save_ptr = ptr;
5076       uschar outsep[2] = { '\0', '\0' };
5077       uschar *list, *expr, *temp;
5078       uschar *save_iterate_item = iterate_item;
5079       uschar *save_lookup_value = lookup_value;
5080
5081       while (isspace(*s)) s++;
5082       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5083
5084       list = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5085       if (list == NULL) goto EXPAND_FAILED;
5086       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5087
5088       if (item_type == EITEM_REDUCE)
5089         {
5090         while (isspace(*s)) s++;
5091         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5092         temp = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5093         if (temp == NULL) goto EXPAND_FAILED;
5094         lookup_value = temp;
5095         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5096         }
5097
5098       while (isspace(*s)) s++;
5099       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5100
5101       expr = s;
5102
5103       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5104       if scanning a "false" part). This allows us to find the end of the
5105       condition, because if the list is empty, we won't actually evaluate the
5106       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5107       the normal internal expansion function. */
5108
5109       if (item_type == EITEM_FILTER)
5110         {
5111         temp = eval_condition(expr, NULL);
5112         if (temp != NULL) s = temp;
5113         }
5114       else
5115         {
5116         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE);
5117         }
5118
5119       if (temp == NULL)
5120         {
5121         expand_string_message = string_sprintf("%s inside \"%s\" item",
5122           expand_string_message, name);
5123         goto EXPAND_FAILED;
5124         }
5125
5126       while (isspace(*s)) s++;
5127       if (*s++ != '}')
5128         {
5129         expand_string_message = string_sprintf("missing } at end of condition "
5130           "or expression inside \"%s\"", name);
5131         goto EXPAND_FAILED;
5132         }
5133
5134       while (isspace(*s)) s++;
5135       if (*s++ != '}')
5136         {
5137         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5138           name);
5139         goto EXPAND_FAILED;
5140         }
5141
5142       /* If we are skipping, we can now just move on to the next item. When
5143       processing for real, we perform the iteration. */
5144
5145       if (skipping) continue;
5146       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5147         {
5148         *outsep = (uschar)sep;      /* Separator as a string */
5149
5150         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5151
5152         if (item_type == EITEM_FILTER)
5153           {
5154           BOOL condresult;
5155           if (eval_condition(expr, &condresult) == NULL)
5156             {
5157             iterate_item = save_iterate_item;
5158             lookup_value = save_lookup_value;
5159             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5160               expand_string_message, name);
5161             goto EXPAND_FAILED;
5162             }
5163           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5164             condresult? "true":"false");
5165           if (condresult)
5166             temp = iterate_item;    /* TRUE => include this item */
5167           else
5168             continue;               /* FALSE => skip this item */
5169           }
5170
5171         /* EITEM_MAP and EITEM_REDUCE */
5172
5173         else
5174           {
5175           temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE);
5176           if (temp == NULL)
5177             {
5178             iterate_item = save_iterate_item;
5179             expand_string_message = string_sprintf("%s inside \"%s\" item",
5180               expand_string_message, name);
5181             goto EXPAND_FAILED;
5182             }
5183           if (item_type == EITEM_REDUCE)
5184             {
5185             lookup_value = temp;      /* Update the value of $value */
5186             continue;                 /* and continue the iteration */
5187             }
5188           }
5189
5190         /* We reach here for FILTER if the condition is true, always for MAP,
5191         and never for REDUCE. The value in "temp" is to be added to the output
5192         list that is being created, ensuring that any occurrences of the
5193         separator character are doubled. Unless we are dealing with the first
5194         item of the output list, add in a space if the new item begins with the
5195         separator character, or is an empty string. */
5196
5197         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5198           yield = string_cat(yield, &size, &ptr, US" ", 1);
5199
5200         /* Add the string in "temp" to the output list that we are building,
5201         This is done in chunks by searching for the separator character. */
5202
5203         for (;;)
5204           {
5205           size_t seglen = Ustrcspn(temp, outsep);
5206             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5207
5208           /* If we got to the end of the string we output one character
5209           too many; backup and end the loop. Otherwise arrange to double the
5210           separator. */
5211
5212           if (temp[seglen] == '\0') { ptr--; break; }
5213           yield = string_cat(yield, &size, &ptr, outsep, 1);
5214           temp += seglen + 1;
5215           }
5216
5217         /* Output a separator after the string: we will remove the redundant
5218         final one at the end. */
5219
5220         yield = string_cat(yield, &size, &ptr, outsep, 1);
5221         }   /* End of iteration over the list loop */
5222
5223       /* REDUCE has generated no output above: output the final value of
5224       $value. */
5225
5226       if (item_type == EITEM_REDUCE)
5227         {
5228         yield = string_cat(yield, &size, &ptr, lookup_value,
5229           Ustrlen(lookup_value));
5230         lookup_value = save_lookup_value;  /* Restore $value */
5231         }
5232
5233       /* FILTER and MAP generate lists: if they have generated anything, remove
5234       the redundant final separator. Even though an empty item at the end of a
5235       list does not count, this is tidier. */
5236
5237       else if (ptr != save_ptr) ptr--;
5238
5239       /* Restore preserved $item */
5240
5241       iterate_item = save_iterate_item;
5242       continue;
5243       }
5244
5245
5246     /* If ${dlfunc support is configured, handle calling dynamically-loaded
5247     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5248     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5249     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5250
5251     #define EXPAND_DLFUNC_MAX_ARGS 8
5252
5253     case EITEM_DLFUNC:
5254     #ifndef EXPAND_DLFUNC
5255     expand_string_message = US"\"${dlfunc\" encountered, but this facility "
5256       "is not included in this binary";
5257     goto EXPAND_FAILED;
5258
5259     #else   /* EXPAND_DLFUNC */
5260       {
5261       tree_node *t;
5262       exim_dlfunc_t *func;
5263       uschar *result;
5264       int status, argc;
5265       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5266
5267       if ((expand_forbid & RDO_DLFUNC) != 0)
5268         {
5269         expand_string_message =
5270           US"dynamically-loaded functions are not permitted";
5271         goto EXPAND_FAILED;
5272         }
5273
5274       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5275            TRUE, US"dlfunc"))
5276         {
5277         case 1: goto EXPAND_FAILED_CURLY;
5278         case 2:
5279         case 3: goto EXPAND_FAILED;
5280         }
5281
5282       /* If skipping, we don't actually do anything */
5283
5284       if (skipping) continue;
5285
5286       /* Look up the dynamically loaded object handle in the tree. If it isn't
5287       found, dlopen() the file and put the handle in the tree for next time. */
5288
5289       t = tree_search(dlobj_anchor, argv[0]);
5290       if (t == NULL)
5291         {
5292         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5293         if (handle == NULL)
5294           {
5295           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5296             argv[0], dlerror());
5297           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5298           goto EXPAND_FAILED;
5299           }
5300         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5301         Ustrcpy(t->name, argv[0]);
5302         t->data.ptr = handle;
5303         (void)tree_insertnode(&dlobj_anchor, t);
5304         }
5305
5306       /* Having obtained the dynamically loaded object handle, look up the
5307       function pointer. */
5308
5309       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5310       if (func == NULL)
5311         {
5312         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5313           "%s", argv[1], argv[0], dlerror());
5314         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5315         goto EXPAND_FAILED;
5316         }
5317
5318       /* Call the function and work out what to do with the result. If it
5319       returns OK, we have a replacement string; if it returns DEFER then
5320       expansion has failed in a non-forced manner; if it returns FAIL then
5321       failure was forced; if it returns ERROR or any other value there's a
5322       problem, so panic slightly. In any case, assume that the function has
5323       side-effects on the store that must be preserved. */
5324
5325       resetok = FALSE;
5326       result = NULL;
5327       for (argc = 0; argv[argc] != NULL; argc++);
5328       status = func(&result, argc - 2, &argv[2]);
5329       if(status == OK)
5330         {
5331         if (result == NULL) result = US"";
5332         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5333         continue;
5334         }
5335       else
5336         {
5337         expand_string_message = result == NULL ? US"(no message)" : result;
5338         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5339           else if(status != FAIL)
5340             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5341               argv[0], argv[1], status, expand_string_message);
5342         goto EXPAND_FAILED;
5343         }
5344       }
5345     #endif /* EXPAND_DLFUNC */
5346     }
5347
5348   /* Control reaches here if the name is not recognized as one of the more
5349   complicated expansion items. Check for the "operator" syntax (name terminated
5350   by a colon). Some of the operators have arguments, separated by _ from the
5351   name. */
5352
5353   if (*s == ':')
5354     {
5355     int c;
5356     uschar *arg = NULL;
5357     uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5358     if (sub == NULL) goto EXPAND_FAILED;
5359     s++;
5360
5361     /* Owing to an historical mis-design, an underscore may be part of the
5362     operator name, or it may introduce arguments.  We therefore first scan the
5363     table of names that contain underscores. If there is no match, we cut off
5364     the arguments and then scan the main table. */
5365
5366     c = chop_match(name, op_table_underscore,
5367       sizeof(op_table_underscore)/sizeof(uschar *));
5368
5369     if (c < 0)
5370       {
5371       arg = Ustrchr(name, '_');
5372       if (arg != NULL) *arg = 0;
5373       c = chop_match(name, op_table_main,
5374         sizeof(op_table_main)/sizeof(uschar *));
5375       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
5376       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
5377       }
5378
5379     /* If we are skipping, we don't need to perform the operation at all.
5380     This matters for operations like "mask", because the data may not be
5381     in the correct format when skipping. For example, the expression may test
5382     for the existence of $sender_host_address before trying to mask it. For
5383     other operations, doing them may not fail, but it is a waste of time. */
5384
5385     if (skipping && c >= 0) continue;
5386
5387     /* Otherwise, switch on the operator type */
5388
5389     switch(c)
5390       {
5391       case EOP_BASE62:
5392         {
5393         uschar *t;
5394         unsigned long int n = Ustrtoul(sub, &t, 10);
5395         if (*t != 0)
5396           {
5397           expand_string_message = string_sprintf("argument for base62 "
5398             "operator is \"%s\", which is not a decimal number", sub);
5399           goto EXPAND_FAILED;
5400           }
5401         t = string_base62(n);
5402         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5403         continue;
5404         }
5405
5406       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
5407
5408       case EOP_BASE62D:
5409         {
5410         uschar buf[16];
5411         uschar *tt = sub;
5412         unsigned long int n = 0;
5413         while (*tt != 0)
5414           {
5415           uschar *t = Ustrchr(base62_chars, *tt++);
5416           if (t == NULL)
5417             {
5418             expand_string_message = string_sprintf("argument for base62d "
5419               "operator is \"%s\", which is not a base %d number", sub,
5420               BASE_62);
5421             goto EXPAND_FAILED;
5422             }
5423           n = n * BASE_62 + (t - base62_chars);
5424           }
5425         (void)sprintf(CS buf, "%ld", n);
5426         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
5427         continue;
5428         }
5429
5430       case EOP_EXPAND:
5431         {
5432         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE);
5433         if (expanded == NULL)
5434           {
5435           expand_string_message =
5436             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
5437               expand_string_message);
5438           goto EXPAND_FAILED;
5439           }
5440         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
5441         continue;
5442         }
5443
5444       case EOP_LC:
5445         {
5446         int count = 0;
5447         uschar *t = sub - 1;
5448         while (*(++t) != 0) { *t = tolower(*t); count++; }
5449         yield = string_cat(yield, &size, &ptr, sub, count);
5450         continue;
5451         }
5452
5453       case EOP_UC:
5454         {
5455         int count = 0;
5456         uschar *t = sub - 1;
5457         while (*(++t) != 0) { *t = toupper(*t); count++; }
5458         yield = string_cat(yield, &size, &ptr, sub, count);
5459         continue;
5460         }
5461
5462       case EOP_MD5:
5463         {
5464         md5 base;
5465         uschar digest[16];
5466         int j;
5467         char st[33];
5468         md5_start(&base);
5469         md5_end(&base, sub, Ustrlen(sub), digest);
5470         for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
5471         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5472         continue;
5473         }
5474
5475       case EOP_SHA1:
5476         {
5477         sha1 base;
5478         uschar digest[20];
5479         int j;
5480         char st[41];
5481         sha1_start(&base);
5482         sha1_end(&base, sub, Ustrlen(sub), digest);
5483         for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
5484         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5485         continue;
5486         }
5487
5488       /* Convert hex encoding to base64 encoding */
5489
5490       case EOP_HEX2B64:
5491         {
5492         int c = 0;
5493         int b = -1;
5494         uschar *in = sub;
5495         uschar *out = sub;
5496         uschar *enc;
5497
5498         for (enc = sub; *enc != 0; enc++)
5499           {
5500           if (!isxdigit(*enc))
5501             {
5502             expand_string_message = string_sprintf("\"%s\" is not a hex "
5503               "string", sub);
5504             goto EXPAND_FAILED;
5505             }
5506           c++;
5507           }
5508
5509         if ((c & 1) != 0)
5510           {
5511           expand_string_message = string_sprintf("\"%s\" contains an odd "
5512             "number of characters", sub);
5513           goto EXPAND_FAILED;
5514           }
5515
5516         while ((c = *in++) != 0)
5517           {
5518           if (isdigit(c)) c -= '0';
5519           else c = toupper(c) - 'A' + 10;
5520           if (b == -1)
5521             {
5522             b = c << 4;
5523             }
5524           else
5525             {
5526             *out++ = b | c;
5527             b = -1;
5528             }
5529           }
5530
5531         enc = auth_b64encode(sub, out - sub);
5532         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
5533         continue;
5534         }
5535
5536       /* count the number of list elements */
5537
5538       case EOP_LISTCOUNT:
5539         {
5540         int cnt = 0;
5541         int sep = 0;
5542         uschar * cp;
5543         uschar buffer[256];
5544
5545         while (string_nextinlist(&sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
5546         cp = string_sprintf("%d", cnt);
5547         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5548         continue;
5549         }
5550
5551       /* expand a named list given the name */
5552       /* handles nested named lists; requotes as colon-sep list */
5553
5554       case EOP_LISTNAMED:
5555         {
5556         tree_node *t = NULL;
5557         uschar * list;
5558         int sep = 0;
5559         uschar * item;
5560         uschar * suffix = "";
5561         BOOL needsep = FALSE;
5562         uschar buffer[256];
5563
5564         if (*sub == '+') sub++;
5565         if (arg == NULL)        /* no-argument version */
5566           {
5567           if (!(t = tree_search(addresslist_anchor, sub)) &&
5568               !(t = tree_search(domainlist_anchor,  sub)) &&
5569               !(t = tree_search(hostlist_anchor,    sub)))
5570             t = tree_search(localpartlist_anchor, sub);
5571           }
5572         else switch(*arg)       /* specific list-type version */
5573           {
5574           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = "_a"; break;
5575           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = "_d"; break;
5576           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = "_h"; break;
5577           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = "_l"; break;
5578           default:
5579             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
5580             goto EXPAND_FAILED;
5581           }
5582
5583         if(!t)
5584           {
5585           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
5586             sub, !arg?""
5587               : *arg=='a'?"address "
5588               : *arg=='d'?"domain "
5589               : *arg=='h'?"host "
5590               : *arg=='l'?"localpart "
5591               : 0);
5592           goto EXPAND_FAILED;
5593           }
5594
5595         list = ((namedlist_block *)(t->data.ptr))->string;
5596
5597         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
5598           {
5599           uschar * buf = US" : ";
5600           if (needsep)
5601             yield = string_cat(yield, &size, &ptr, buf, 3);
5602           else
5603             needsep = TRUE;
5604
5605           if (*item == '+')     /* list item is itself a named list */
5606             {
5607             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
5608             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE);
5609             }
5610           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
5611             {
5612             char * cp;
5613             char tok[3];
5614             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
5615             while ((cp= strpbrk((const char *)item, tok)))
5616               {
5617               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
5618               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
5619                 {
5620                 yield = string_cat(yield, &size, &ptr, US"::", 2);
5621                 item = cp;
5622                 }
5623               else              /* sep in item; should already be doubled; emit once */
5624                 {
5625                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
5626                 if (*cp == sep) cp++;
5627                 item = cp;
5628                 }
5629               }
5630             }
5631           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
5632           }
5633         continue;
5634         }
5635
5636       /* mask applies a mask to an IP address; for example the result of
5637       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
5638
5639       case EOP_MASK:
5640         {
5641         int count;
5642         uschar *endptr;
5643         int binary[4];
5644         int mask, maskoffset;
5645         int type = string_is_ip_address(sub, &maskoffset);
5646         uschar buffer[64];
5647
5648         if (type == 0)
5649           {
5650           expand_string_message = string_sprintf("\"%s\" is not an IP address",
5651            sub);
5652           goto EXPAND_FAILED;
5653           }
5654
5655         if (maskoffset == 0)
5656           {
5657           expand_string_message = string_sprintf("missing mask value in \"%s\"",
5658             sub);
5659           goto EXPAND_FAILED;
5660           }
5661
5662         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
5663
5664         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
5665           {
5666           expand_string_message = string_sprintf("mask value too big in \"%s\"",
5667             sub);
5668           goto EXPAND_FAILED;
5669           }
5670
5671         /* Convert the address to binary integer(s) and apply the mask */
5672
5673         sub[maskoffset] = 0;
5674         count = host_aton(sub, binary);
5675         host_mask(count, binary, mask);
5676
5677         /* Convert to masked textual format and add to output. */
5678
5679         yield = string_cat(yield, &size, &ptr, buffer,
5680           host_nmtoa(count, binary, mask, buffer, '.'));
5681         continue;
5682         }
5683
5684       case EOP_ADDRESS:
5685       case EOP_LOCAL_PART:
5686       case EOP_DOMAIN:
5687         {
5688         uschar *error;
5689         int start, end, domain;
5690         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
5691           FALSE);
5692         if (t != NULL)
5693           {
5694           if (c != EOP_DOMAIN)
5695             {
5696             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
5697             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
5698             }
5699           else if (domain != 0)
5700             {
5701             domain += start;
5702             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
5703             }
5704           }
5705         continue;
5706         }
5707
5708       case EOP_ADDRESSES:
5709         {
5710         uschar outsep[2] = { ':', '\0' };
5711         uschar *address, *error;
5712         int save_ptr = ptr;
5713         int start, end, domain;  /* Not really used */
5714
5715         while (isspace(*sub)) sub++;
5716         if (*sub == '>') { *outsep = *++sub; ++sub; }
5717         parse_allow_group = TRUE;
5718
5719         for (;;)
5720           {
5721           uschar *p = parse_find_address_end(sub, FALSE);
5722           uschar saveend = *p;
5723           *p = '\0';
5724           address = parse_extract_address(sub, &error, &start, &end, &domain,
5725             FALSE);
5726           *p = saveend;
5727
5728           /* Add the address to the output list that we are building. This is
5729           done in chunks by searching for the separator character. At the
5730           start, unless we are dealing with the first address of the output
5731           list, add in a space if the new address begins with the separator
5732           character, or is an empty string. */
5733
5734           if (address != NULL)
5735             {
5736             if (ptr != save_ptr && address[0] == *outsep)
5737               yield = string_cat(yield, &size, &ptr, US" ", 1);
5738
5739             for (;;)
5740               {
5741               size_t seglen = Ustrcspn(address, outsep);
5742               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
5743
5744               /* If we got to the end of the string we output one character
5745               too many. */
5746
5747               if (address[seglen] == '\0') { ptr--; break; }
5748               yield = string_cat(yield, &size, &ptr, outsep, 1);
5749               address += seglen + 1;
5750               }
5751
5752             /* Output a separator after the string: we will remove the
5753             redundant final one at the end. */
5754
5755             yield = string_cat(yield, &size, &ptr, outsep, 1);
5756             }
5757
5758           if (saveend == '\0') break;
5759           sub = p + 1;
5760           }
5761
5762         /* If we have generated anything, remove the redundant final
5763         separator. */
5764
5765         if (ptr != save_ptr) ptr--;
5766         parse_allow_group = FALSE;
5767         continue;
5768         }
5769
5770
5771       /* quote puts a string in quotes if it is empty or contains anything
5772       other than alphamerics, underscore, dot, or hyphen.
5773
5774       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
5775       be quoted in order to be a valid local part.
5776
5777       In both cases, newlines and carriage returns are converted into \n and \r
5778       respectively */
5779
5780       case EOP_QUOTE:
5781       case EOP_QUOTE_LOCAL_PART:
5782       if (arg == NULL)
5783         {
5784         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
5785         uschar *t = sub - 1;
5786
5787         if (c == EOP_QUOTE)
5788           {
5789           while (!needs_quote && *(++t) != 0)
5790             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
5791           }
5792         else  /* EOP_QUOTE_LOCAL_PART */
5793           {
5794           while (!needs_quote && *(++t) != 0)
5795             needs_quote = !isalnum(*t) &&
5796               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
5797               (*t != '.' || t == sub || t[1] == 0);
5798           }
5799
5800         if (needs_quote)
5801           {
5802           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5803           t = sub - 1;
5804           while (*(++t) != 0)
5805             {
5806             if (*t == '\n')
5807               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
5808             else if (*t == '\r')
5809               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
5810             else
5811               {
5812               if (*t == '\\' || *t == '"')
5813                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
5814               yield = string_cat(yield, &size, &ptr, t, 1);
5815               }
5816             }
5817           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5818           }
5819         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5820         continue;
5821         }
5822
5823       /* quote_lookuptype does lookup-specific quoting */
5824
5825       else
5826         {
5827         int n;
5828         uschar *opt = Ustrchr(arg, '_');
5829
5830         if (opt != NULL) *opt++ = 0;
5831
5832         n = search_findtype(arg, Ustrlen(arg));
5833         if (n < 0)
5834           {
5835           expand_string_message = search_error_message;
5836           goto EXPAND_FAILED;
5837           }
5838
5839         if (lookup_list[n]->quote != NULL)
5840           sub = (lookup_list[n]->quote)(sub, opt);
5841         else if (opt != NULL) sub = NULL;
5842
5843         if (sub == NULL)
5844           {
5845           expand_string_message = string_sprintf(
5846             "\"%s\" unrecognized after \"${quote_%s\"",
5847             opt, arg);
5848           goto EXPAND_FAILED;
5849           }
5850
5851         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5852         continue;
5853         }
5854
5855       /* rx quote sticks in \ before any non-alphameric character so that
5856       the insertion works in a regular expression. */
5857
5858       case EOP_RXQUOTE:
5859         {
5860         uschar *t = sub - 1;
5861         while (*(++t) != 0)
5862           {
5863           if (!isalnum(*t))
5864             yield = string_cat(yield, &size, &ptr, US"\\", 1);
5865           yield = string_cat(yield, &size, &ptr, t, 1);
5866           }
5867         continue;
5868         }
5869
5870       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
5871       prescribed by the RFC, if there are characters that need to be encoded */
5872
5873       case EOP_RFC2047:
5874         {
5875         uschar buffer[2048];
5876         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
5877           buffer, sizeof(buffer), FALSE);
5878         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
5879         continue;
5880         }
5881
5882       /* RFC 2047 decode */
5883
5884       case EOP_RFC2047D:
5885         {
5886         int len;
5887         uschar *error;
5888         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
5889           headers_charset, '?', &len, &error);
5890         if (error != NULL)
5891           {
5892           expand_string_message = error;
5893           goto EXPAND_FAILED;
5894           }
5895         yield = string_cat(yield, &size, &ptr, decoded, len);
5896         continue;
5897         }
5898
5899       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
5900       underscores */
5901
5902       case EOP_FROM_UTF8:
5903         {
5904         while (*sub != 0)
5905           {
5906           int c;
5907           uschar buff[4];
5908           GETUTF8INC(c, sub);
5909           if (c > 255) c = '_';
5910           buff[0] = c;
5911           yield = string_cat(yield, &size, &ptr, buff, 1);
5912           }
5913         continue;
5914         }
5915
5916       /* escape turns all non-printing characters into escape sequences. */
5917
5918       case EOP_ESCAPE:
5919         {
5920         uschar *t = string_printing(sub);
5921         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5922         continue;
5923         }
5924
5925       /* Handle numeric expression evaluation */
5926
5927       case EOP_EVAL:
5928       case EOP_EVAL10:
5929         {
5930         uschar *save_sub = sub;
5931         uschar *error = NULL;
5932         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
5933         if (error != NULL)
5934           {
5935           expand_string_message = string_sprintf("error in expression "
5936             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
5937               save_sub);
5938           goto EXPAND_FAILED;
5939           }
5940         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
5941         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
5942         continue;
5943         }
5944
5945       /* Handle time period formating */
5946
5947       case EOP_TIME_EVAL:
5948         {
5949         int n = readconf_readtime(sub, 0, FALSE);
5950         if (n < 0)
5951           {
5952           expand_string_message = string_sprintf("string \"%s\" is not an "
5953             "Exim time interval in \"%s\" operator", sub, name);
5954           goto EXPAND_FAILED;
5955           }
5956         sprintf(CS var_buffer, "%d", n);
5957         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
5958         continue;
5959         }
5960
5961       case EOP_TIME_INTERVAL:
5962         {
5963         int n;
5964         uschar *t = read_number(&n, sub);
5965         if (*t != 0) /* Not A Number*/
5966           {
5967           expand_string_message = string_sprintf("string \"%s\" is not a "
5968             "positive number in \"%s\" operator", sub, name);
5969           goto EXPAND_FAILED;
5970           }
5971         t = readconf_printtime(n);
5972         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5973         continue;
5974         }
5975
5976       /* Convert string to base64 encoding */
5977
5978       case EOP_STR2B64:
5979         {
5980         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
5981         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
5982         continue;
5983         }
5984
5985       /* strlen returns the length of the string */
5986
5987       case EOP_STRLEN:
5988         {
5989         uschar buff[24];
5990         (void)sprintf(CS buff, "%d", Ustrlen(sub));
5991         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
5992         continue;
5993         }
5994
5995       /* length_n or l_n takes just the first n characters or the whole string,
5996       whichever is the shorter;
5997
5998       substr_m_n, and s_m_n take n characters from offset m; negative m take
5999       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6000       takes the rest, either to the right or to the left.
6001
6002       hash_n or h_n makes a hash of length n from the string, yielding n
6003       characters from the set a-z; hash_n_m makes a hash of length n, but
6004       uses m characters from the set a-zA-Z0-9.
6005
6006       nhash_n returns a single number between 0 and n-1 (in text form), while
6007       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6008       between 0 and n-1 and the second between 0 and m-1. */
6009
6010       case EOP_LENGTH:
6011       case EOP_L:
6012       case EOP_SUBSTR:
6013       case EOP_S:
6014       case EOP_HASH:
6015       case EOP_H:
6016       case EOP_NHASH:
6017       case EOP_NH:
6018         {
6019         int sign = 1;
6020         int value1 = 0;
6021         int value2 = -1;
6022         int *pn;
6023         int len;
6024         uschar *ret;
6025
6026         if (arg == NULL)
6027           {
6028           expand_string_message = string_sprintf("missing values after %s",
6029             name);
6030           goto EXPAND_FAILED;
6031           }
6032
6033         /* "length" has only one argument, effectively being synonymous with
6034         substr_0_n. */
6035
6036         if (c == EOP_LENGTH || c == EOP_L)
6037           {
6038           pn = &value2;
6039           value2 = 0;
6040           }
6041
6042         /* The others have one or two arguments; for "substr" the first may be
6043         negative. The second being negative means "not supplied". */
6044
6045         else
6046           {
6047           pn = &value1;
6048           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6049           }
6050
6051         /* Read up to two numbers, separated by underscores */
6052
6053         ret = arg;
6054         while (*arg != 0)
6055           {
6056           if (arg != ret && *arg == '_' && pn == &value1)
6057             {
6058             pn = &value2;
6059             value2 = 0;
6060             if (arg[1] != 0) arg++;
6061             }
6062           else if (!isdigit(*arg))
6063             {
6064             expand_string_message =
6065               string_sprintf("non-digit after underscore in \"%s\"", name);
6066             goto EXPAND_FAILED;
6067             }
6068           else *pn = (*pn)*10 + *arg++ - '0';
6069           }
6070         value1 *= sign;
6071
6072         /* Perform the required operation */
6073
6074         ret =
6075           (c == EOP_HASH || c == EOP_H)?
6076              compute_hash(sub, value1, value2, &len) :
6077           (c == EOP_NHASH || c == EOP_NH)?
6078              compute_nhash(sub, value1, value2, &len) :
6079              extract_substr(sub, value1, value2, &len);
6080
6081         if (ret == NULL) goto EXPAND_FAILED;
6082         yield = string_cat(yield, &size, &ptr, ret, len);
6083         continue;
6084         }
6085
6086       /* Stat a path */
6087
6088       case EOP_STAT:
6089         {
6090         uschar *s;
6091         uschar smode[12];
6092         uschar **modetable[3];
6093         int i;
6094         mode_t mode;
6095         struct stat st;
6096
6097         if ((expand_forbid & RDO_EXISTS) != 0)
6098           {
6099           expand_string_message = US"Use of the stat() expansion is not permitted";
6100           goto EXPAND_FAILED;
6101           }
6102
6103         if (stat(CS sub, &st) < 0)
6104           {
6105           expand_string_message = string_sprintf("stat(%s) failed: %s",
6106             sub, strerror(errno));
6107           goto EXPAND_FAILED;
6108           }
6109         mode = st.st_mode;
6110         switch (mode & S_IFMT)
6111           {
6112           case S_IFIFO: smode[0] = 'p'; break;
6113           case S_IFCHR: smode[0] = 'c'; break;
6114           case S_IFDIR: smode[0] = 'd'; break;
6115           case S_IFBLK: smode[0] = 'b'; break;
6116           case S_IFREG: smode[0] = '-'; break;
6117           default: smode[0] = '?'; break;
6118           }
6119
6120         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
6121         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
6122         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
6123
6124         for (i = 0; i < 3; i++)
6125           {
6126           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
6127           mode >>= 3;
6128           }
6129
6130         smode[10] = 0;
6131         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
6132           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
6133           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
6134           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
6135           (long)st.st_gid, st.st_size, (long)st.st_atime,
6136           (long)st.st_mtime, (long)st.st_ctime);
6137         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6138         continue;
6139         }
6140
6141       /* vaguely random number less than N */
6142
6143       case EOP_RANDINT:
6144         {
6145         int_eximarith_t max;
6146         uschar *s;
6147
6148         max = expand_string_integer(sub, TRUE);
6149         if (expand_string_message != NULL)
6150           goto EXPAND_FAILED;
6151         s = string_sprintf("%d", vaguely_random_number((int)max));
6152         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6153         continue;
6154         }
6155
6156       /* Reverse IP, including IPv6 to dotted-nibble */
6157
6158       case EOP_REVERSE_IP:
6159         {
6160         int family, maskptr;
6161         uschar reversed[128];
6162
6163         family = string_is_ip_address(sub, &maskptr);
6164         if (family == 0)
6165           {
6166           expand_string_message = string_sprintf(
6167               "reverse_ip() not given an IP address [%s]", sub);
6168           goto EXPAND_FAILED;
6169           }
6170         invert_address(reversed, sub);
6171         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
6172         continue;
6173         }
6174
6175       /* Unknown operator */
6176
6177       default:
6178       expand_string_message =
6179         string_sprintf("unknown expansion operator \"%s\"", name);
6180       goto EXPAND_FAILED;
6181       }
6182     }
6183
6184   /* Handle a plain name. If this is the first thing in the expansion, release
6185   the pre-allocated buffer. If the result data is known to be in a new buffer,
6186   newsize will be set to the size of that buffer, and we can just point at that
6187   store instead of copying. Many expansion strings contain just one reference,
6188   so this is a useful optimization, especially for humungous headers
6189   ($message_headers). */
6190
6191   if (*s++ == '}')
6192     {
6193     int len;
6194     int newsize = 0;
6195     if (ptr == 0)
6196       {
6197       if (resetok) store_reset(yield);
6198       yield = NULL;
6199       size = 0;
6200       }
6201     value = find_variable(name, FALSE, skipping, &newsize);
6202     if (value == NULL)
6203       {
6204       expand_string_message =
6205         string_sprintf("unknown variable in \"${%s}\"", name);
6206       check_variable_error_message(name);
6207       goto EXPAND_FAILED;
6208       }
6209     len = Ustrlen(value);
6210     if (yield == NULL && newsize != 0)
6211       {
6212       yield = value;
6213       size = newsize;
6214       ptr = len;
6215       }
6216     else yield = string_cat(yield, &size, &ptr, value, len);
6217     continue;
6218     }
6219
6220   /* Else there's something wrong */
6221
6222   expand_string_message =
6223     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
6224     "in a variable reference)", name);
6225   goto EXPAND_FAILED;
6226   }
6227
6228 /* If we hit the end of the string when ket_ends is set, there is a missing
6229 terminating brace. */
6230
6231 if (ket_ends && *s == 0)
6232   {
6233   expand_string_message = malformed_header?
6234     US"missing } at end of string - could be header name not terminated by colon"
6235     :
6236     US"missing } at end of string";
6237   goto EXPAND_FAILED;
6238   }
6239
6240 /* Expansion succeeded; yield may still be NULL here if nothing was actually
6241 added to the string. If so, set up an empty string. Add a terminating zero. If
6242 left != NULL, return a pointer to the terminator. */
6243
6244 if (yield == NULL) yield = store_get(1);
6245 yield[ptr] = 0;
6246 if (left != NULL) *left = s;
6247
6248 /* Any stacking store that was used above the final string is no longer needed.
6249 In many cases the final string will be the first one that was got and so there
6250 will be optimal store usage. */
6251
6252 if (resetok) store_reset(yield + ptr + 1);
6253 DEBUG(D_expand)
6254   {
6255   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
6256     yield);
6257   if (skipping) debug_printf("skipping: result is not used\n");
6258   }
6259 return yield;
6260
6261 /* This is the failure exit: easiest to program with a goto. We still need
6262 to update the pointer to the terminator, for cases of nested calls with "fail".
6263 */
6264
6265 EXPAND_FAILED_CURLY:
6266 expand_string_message = malformed_header?
6267   US"missing or misplaced { or } - could be header name not terminated by colon"
6268   :
6269   US"missing or misplaced { or }";
6270
6271 /* At one point, Exim reset the store to yield (if yield was not NULL), but
6272 that is a bad idea, because expand_string_message is in dynamic store. */
6273
6274 EXPAND_FAILED:
6275 if (left != NULL) *left = s;
6276 DEBUG(D_expand)
6277   {
6278   debug_printf("failed to expand: %s\n", string);
6279   debug_printf("   error message: %s\n", expand_string_message);
6280   if (expand_string_forcedfail) debug_printf("failure was forced\n");
6281   }
6282 return NULL;
6283 }
6284
6285
6286 /* This is the external function call. Do a quick check for any expansion
6287 metacharacters, and if there are none, just return the input string.
6288
6289 Argument: the string to be expanded
6290 Returns:  the expanded string, or NULL if expansion failed; if failure was
6291           due to a lookup deferring, search_find_defer will be TRUE
6292 */
6293
6294 uschar *
6295 expand_string(uschar *string)
6296 {
6297 search_find_defer = FALSE;
6298 malformed_header = FALSE;
6299 return (Ustrpbrk(string, "$\\") == NULL)? string :
6300   expand_string_internal(string, FALSE, NULL, FALSE, TRUE);
6301 }
6302
6303
6304
6305 /*************************************************
6306 *              Expand and copy                   *
6307 *************************************************/
6308
6309 /* Now and again we want to expand a string and be sure that the result is in a
6310 new bit of store. This function does that.
6311
6312 Argument: the string to be expanded
6313 Returns:  the expanded string, always in a new bit of store, or NULL
6314 */
6315
6316 uschar *
6317 expand_string_copy(uschar *string)
6318 {
6319 uschar *yield = expand_string(string);
6320 if (yield == string) yield = string_copy(string);
6321 return yield;
6322 }
6323
6324
6325
6326 /*************************************************
6327 *        Expand and interpret as an integer      *
6328 *************************************************/
6329
6330 /* Expand a string, and convert the result into an integer.
6331
6332 Arguments:
6333   string  the string to be expanded
6334   isplus  TRUE if a non-negative number is expected
6335
6336 Returns:  the integer value, or
6337           -1 for an expansion error               ) in both cases, message in
6338           -2 for an integer interpretation error  ) expand_string_message
6339           expand_string_message is set NULL for an OK integer
6340 */
6341
6342 int_eximarith_t
6343 expand_string_integer(uschar *string, BOOL isplus)
6344 {
6345 int_eximarith_t value;
6346 uschar *s = expand_string(string);
6347 uschar *msg = US"invalid integer \"%s\"";
6348 uschar *endptr;
6349
6350 /* If expansion failed, expand_string_message will be set. */
6351
6352 if (s == NULL) return -1;
6353
6354 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
6355 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
6356 systems, so we set it zero ourselves. */
6357
6358 errno = 0;
6359 expand_string_message = NULL;               /* Indicates no error */
6360
6361 /* Before Exim 4.64, strings consisting entirely of whitespace compared
6362 equal to 0.  Unfortunately, people actually relied upon that, so preserve
6363 the behaviour explicitly.  Stripping leading whitespace is a harmless
6364 noop change since strtol skips it anyway (provided that there is a number
6365 to find at all). */
6366 if (isspace(*s))
6367   {
6368   while (isspace(*s)) ++s;
6369   if (*s == '\0')
6370     {
6371       DEBUG(D_expand)
6372        debug_printf("treating blank string as number 0\n");
6373       return 0;
6374     }
6375   }
6376
6377 value = strtoll(CS s, CSS &endptr, 10);
6378
6379 if (endptr == s)
6380   {
6381   msg = US"integer expected but \"%s\" found";
6382   }
6383 else if (value < 0 && isplus)
6384   {
6385   msg = US"non-negative integer expected but \"%s\" found";
6386   }
6387 else
6388   {
6389   switch (tolower(*endptr))
6390     {
6391     default:
6392       break;
6393     case 'k':
6394       if (value > LLONG_MAX/1024 || value < LLONG_MIN/1024) errno = ERANGE;
6395       else value *= 1024;
6396       endptr++;
6397       break;
6398     case 'm':
6399       if (value > LLONG_MAX/(1024*1024) || value < LLONG_MIN/(1024*1024)) errno = ERANGE;
6400       else value *= 1024*1024;
6401       endptr++;
6402       break;
6403     case 'g':
6404       if (value > LLONG_MAX/(1024*1024*1024) || value < LLONG_MIN/(1024*1024*1024)) errno = ERANGE;
6405       else value *= 1024*1024*1024;
6406       endptr++;
6407       break;
6408     }
6409   if (errno == ERANGE)
6410     msg = US"absolute value of integer \"%s\" is too large (overflow)";
6411   else
6412     {
6413     while (isspace(*endptr)) endptr++;
6414     if (*endptr == 0) return (int)value;
6415     }
6416   }
6417
6418 expand_string_message = string_sprintf(CS msg, s);
6419 return -2;
6420 }
6421
6422
6423 /*************************************************
6424 **************************************************
6425 *             Stand-alone test program           *
6426 **************************************************
6427 *************************************************/
6428
6429 #ifdef STAND_ALONE
6430
6431
6432 BOOL
6433 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
6434 {
6435 int ovector[3*(EXPAND_MAXN+1)];
6436 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
6437   ovector, sizeof(ovector)/sizeof(int));
6438 BOOL yield = n >= 0;
6439 if (n == 0) n = EXPAND_MAXN + 1;
6440 if (yield)
6441   {
6442   int nn;
6443   expand_nmax = (setup < 0)? 0 : setup + 1;
6444   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
6445     {
6446     expand_nstring[expand_nmax] = subject + ovector[nn];
6447     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
6448     }
6449   expand_nmax--;
6450   }
6451 return yield;
6452 }
6453
6454
6455 int main(int argc, uschar **argv)
6456 {
6457 int i;
6458 uschar buffer[1024];
6459
6460 debug_selector = D_v;
6461 debug_file = stderr;
6462 debug_fd = fileno(debug_file);
6463 big_buffer = malloc(big_buffer_size);
6464
6465 for (i = 1; i < argc; i++)
6466   {
6467   if (argv[i][0] == '+')
6468     {
6469     debug_trace_memory = 2;
6470     argv[i]++;
6471     }
6472   if (isdigit(argv[i][0]))
6473     debug_selector = Ustrtol(argv[i], NULL, 0);
6474   else
6475     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
6476         Ustrlen(argv[i]))
6477       {
6478       #ifdef LOOKUP_LDAP
6479       eldap_default_servers = argv[i];
6480       #endif
6481       #ifdef LOOKUP_MYSQL
6482       mysql_servers = argv[i];
6483       #endif
6484       #ifdef LOOKUP_PGSQL
6485       pgsql_servers = argv[i];
6486       #endif
6487       }
6488   #ifdef EXIM_PERL
6489   else opt_perl_startup = argv[i];
6490   #endif
6491   }
6492
6493 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
6494
6495 expand_nstring[1] = US"string 1....";
6496 expand_nlength[1] = 8;
6497 expand_nmax = 1;
6498
6499 #ifdef EXIM_PERL
6500 if (opt_perl_startup != NULL)
6501   {
6502   uschar *errstr;
6503   printf("Starting Perl interpreter\n");
6504   errstr = init_perl(opt_perl_startup);
6505   if (errstr != NULL)
6506     {
6507     printf("** error in perl_startup code: %s\n", errstr);
6508     return EXIT_FAILURE;
6509     }
6510   }
6511 #endif /* EXIM_PERL */
6512
6513 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
6514   {
6515   void *reset_point = store_get(0);
6516   uschar *yield = expand_string(buffer);
6517   if (yield != NULL)
6518     {
6519     printf("%s\n", yield);
6520     store_reset(reset_point);
6521     }
6522   else
6523     {
6524     if (search_find_defer) printf("search_find deferred\n");
6525     printf("Failed: %s\n", expand_string_message);
6526     if (expand_string_forcedfail) printf("Forced failure\n");
6527     printf("\n");
6528     }
6529   }
6530
6531 search_tidyup();
6532
6533 return 0;
6534 }
6535
6536 #endif
6537
6538 /* End of expand.c */