src/src/expand.c

   1 /* $Cambridge: exim/src/src/expand.c,v 1.81 2007/02/10 23:51:11 magnus Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2007 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10
  11 /* Functions for handling string expansion. */
  12
  13
  14 #include "exim.h"
  15
  16 /* Recursively called function */
  17
  18 static uschar *expand_string_internal(uschar *, BOOL, uschar **, BOOL);
  19
  20 #ifdef STAND_ALONE
  21 #ifndef SUPPORT_CRYPTEQ
  22 #define SUPPORT_CRYPTEQ
  23 #endif
  24 #endif
  25
  26 #ifdef LOOKUP_LDAP
  27 #include "lookups/ldap.h"
  28 #endif
  29
  30 #ifdef SUPPORT_CRYPTEQ
  31 #ifdef CRYPT_H
  32 #include <crypt.h>
  33 #endif
  34 #ifndef HAVE_CRYPT16
  35 extern char* crypt16(char*, char*);
  36 #endif
  37 #endif
  38
  39 /* The handling of crypt16() is a mess. I will record below the analysis of the
  40 mess that was sent to me. We decided, however, to make changing this very low
  41 priority, because in practice people are moving away from the crypt()
  42 algorithms nowadays, so it doesn't seem worth it.
  43
  44 <quote>
  45 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  46 the first 8 characters of the password using a 20-round version of crypt
  47 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  48 or an empty block if the password is less than 9 characters, using a
  49 20-round version of crypt and the same salt as was used for the first
  50 block.  Charaters after the first 16 are ignored.  It always generates
  51 a 16-byte hash, which is expressed together with the salt as a string
  52 of 24 base 64 digits.  Here are some links to peruse:
  53
  54         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  55         http://seclists.org/bugtraq/1999/Mar/0076.html
  56
  57 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  58 and OSF/1.  This is the same as the standard crypt if given a password
  59 of 8 characters or less.  If given more, it first does the same as crypt
  60 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  61 using as salt the first two base 64 digits from the first hash block.
  62 If the password is more than 16 characters then it crypts the 17th to 24th
  63 characters using as salt the first two base 64 digits from the second hash
  64 block.  And so on: I've seen references to it cutting off the password at
  65 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  66
  67         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  68         http://seclists.org/bugtraq/1999/Mar/0109.html
  69         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  70              TET1_html/sec.c222.html#no_id_208
  71
  72 Exim has something it calls "crypt16".  It will either use a native
  73 crypt16 or its own implementation.  A native crypt16 will presumably
  74 be the one that I called "crypt16" above.  The internal "crypt16"
  75 function, however, is a two-block-maximum implementation of what I called
  76 "bigcrypt".  The documentation matches the internal code.
  77
  78 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  79 that crypt16 and bigcrypt were different things.
  80
  81 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  82 to whatever it is using under that name.  This unfortunately sets a
  83 precedent for using "{crypt16}" to identify two incompatible algorithms
  84 whose output can't be distinguished.  With "{crypt16}" thus rendered
  85 ambiguous, I suggest you deprecate it and invent two new identifiers
  86 for the two algorithms.
  87
  88 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  89 of the password separately means they can be cracked separately, so
  90 the double-length hash only doubles the cracking effort instead of
  91 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  92 bcrypt ({CRYPT}$2a$).
  93 </quote>
  94 */
  95
  96
  97
  98
  99 /*************************************************
 100 *            Local statics and tables            *
 101 *************************************************/
 102
 103 /* Table of item names, and corresponding switch numbers. The names must be in
 104 alphabetical order. */
 105
 106 static uschar *item_table[] = {
 107   US"dlfunc",
 108   US"extract",
 109   US"hash",
 110   US"hmac",
 111   US"if",
 112   US"length",
 113   US"lookup",
 114   US"nhash",
 115   US"perl",
 116   US"prvs",
 117   US"prvscheck",
 118   US"readfile",
 119   US"readsocket",
 120   US"run",
 121   US"sg",
 122   US"substr",
 123   US"tr" };
 124
 125 enum {
 126   EITEM_DLFUNC,
 127   EITEM_EXTRACT,
 128   EITEM_HASH,
 129   EITEM_HMAC,
 130   EITEM_IF,
 131   EITEM_LENGTH,
 132   EITEM_LOOKUP,
 133   EITEM_NHASH,
 134   EITEM_PERL,
 135   EITEM_PRVS,
 136   EITEM_PRVSCHECK,
 137   EITEM_READFILE,
 138   EITEM_READSOCK,
 139   EITEM_RUN,
 140   EITEM_SG,
 141   EITEM_SUBSTR,
 142   EITEM_TR };
 143
 144 /* Tables of operator names, and corresponding switch numbers. The names must be
 145 in alphabetical order. There are two tables, because underscore is used in some
 146 cases to introduce arguments, whereas for other it is part of the name. This is
 147 an historical mis-design. */
 148
 149 static uschar *op_table_underscore[] = {
 150   US"from_utf8",
 151   US"local_part",
 152   US"quote_local_part",
 153   US"time_eval",
 154   US"time_interval"};
 155
 156 enum {
 157   EOP_FROM_UTF8,
 158   EOP_LOCAL_PART,
 159   EOP_QUOTE_LOCAL_PART,
 160   EOP_TIME_EVAL,
 161   EOP_TIME_INTERVAL };
 162
 163 static uschar *op_table_main[] = {
 164   US"address",
 165   US"base62",
 166   US"base62d",
 167   US"domain",
 168   US"escape",
 169   US"eval",
 170   US"eval10",
 171   US"expand",
 172   US"h",
 173   US"hash",
 174   US"hex2b64",
 175   US"l",
 176   US"lc",
 177   US"length",
 178   US"mask",
 179   US"md5",
 180   US"nh",
 181   US"nhash",
 182   US"quote",
 183   US"rfc2047",
 184   US"rfc2047d",
 185   US"rxquote",
 186   US"s",
 187   US"sha1",
 188   US"stat",
 189   US"str2b64",
 190   US"strlen",
 191   US"substr",
 192   US"uc" };
 193
 194 enum {
 195   EOP_ADDRESS =  sizeof(op_table_underscore)/sizeof(uschar *),
 196   EOP_BASE62,
 197   EOP_BASE62D,
 198   EOP_DOMAIN,
 199   EOP_ESCAPE,
 200   EOP_EVAL,
 201   EOP_EVAL10,
 202   EOP_EXPAND,
 203   EOP_H,
 204   EOP_HASH,
 205   EOP_HEX2B64,
 206   EOP_L,
 207   EOP_LC,
 208   EOP_LENGTH,
 209   EOP_MASK,
 210   EOP_MD5,
 211   EOP_NH,
 212   EOP_NHASH,
 213   EOP_QUOTE,
 214   EOP_RFC2047,
 215   EOP_RFC2047D,
 216   EOP_RXQUOTE,
 217   EOP_S,
 218   EOP_SHA1,
 219   EOP_STAT,
 220   EOP_STR2B64,
 221   EOP_STRLEN,
 222   EOP_SUBSTR,
 223   EOP_UC };
 224
 225
 226 /* Table of condition names, and corresponding switch numbers. The names must
 227 be in alphabetical order. */
 228
 229 static uschar *cond_table[] = {
 230   US"<",
 231   US"<=",
 232   US"=",
 233   US"==",     /* Backward compatibility */
 234   US">",
 235   US">=",
 236   US"and",
 237   US"crypteq",
 238   US"def",
 239   US"eq",
 240   US"eqi",
 241   US"exists",
 242   US"first_delivery",
 243   US"forall",
 244   US"forany",
 245   US"ge",
 246   US"gei",
 247   US"gt",
 248   US"gti",
 249   US"isip",
 250   US"isip4",
 251   US"isip6",
 252   US"ldapauth",
 253   US"le",
 254   US"lei",
 255   US"lt",
 256   US"lti",
 257   US"match",
 258   US"match_address",
 259   US"match_domain",
 260   US"match_ip",
 261   US"match_local_part",
 262   US"or",
 263   US"pam",
 264   US"pwcheck",
 265   US"queue_running",
 266   US"radius",
 267   US"saslauthd"
 268 };
 269
 270 enum {
 271   ECOND_NUM_L,
 272   ECOND_NUM_LE,
 273   ECOND_NUM_E,
 274   ECOND_NUM_EE,
 275   ECOND_NUM_G,
 276   ECOND_NUM_GE,
 277   ECOND_AND,
 278   ECOND_CRYPTEQ,
 279   ECOND_DEF,
 280   ECOND_STR_EQ,
 281   ECOND_STR_EQI,
 282   ECOND_EXISTS,
 283   ECOND_FIRST_DELIVERY,
 284   ECOND_FORALL,
 285   ECOND_FORANY,
 286   ECOND_STR_GE,
 287   ECOND_STR_GEI,
 288   ECOND_STR_GT,
 289   ECOND_STR_GTI,
 290   ECOND_ISIP,
 291   ECOND_ISIP4,
 292   ECOND_ISIP6,
 293   ECOND_LDAPAUTH,
 294   ECOND_STR_LE,
 295   ECOND_STR_LEI,
 296   ECOND_STR_LT,
 297   ECOND_STR_LTI,
 298   ECOND_MATCH,
 299   ECOND_MATCH_ADDRESS,
 300   ECOND_MATCH_DOMAIN,
 301   ECOND_MATCH_IP,
 302   ECOND_MATCH_LOCAL_PART,
 303   ECOND_OR,
 304   ECOND_PAM,
 305   ECOND_PWCHECK,
 306   ECOND_QUEUE_RUNNING,
 307   ECOND_RADIUS,
 308   ECOND_SASLAUTHD
 309 };
 310
 311
 312 /* Type for main variable table */
 313
 314 typedef struct {
 315   char *name;
 316   int   type;
 317   void *value;
 318 } var_entry;
 319
 320 /* Type for entries pointing to address/length pairs. Not currently
 321 in use. */
 322
 323 typedef struct {
 324   uschar **address;
 325   int  *length;
 326 } alblock;
 327
 328 /* Types of table entry */
 329
 330 enum {
 331   vtype_int,            /* value is address of int */
 332   vtype_filter_int,     /* ditto, but recognized only when filtering */
 333   vtype_ino,            /* value is address of ino_t (not always an int) */
 334   vtype_uid,            /* value is address of uid_t (not always an int) */
 335   vtype_gid,            /* value is address of gid_t (not always an int) */
 336   vtype_stringptr,      /* value is address of pointer to string */
 337   vtype_msgbody,        /* as stringptr, but read when first required */
 338   vtype_msgbody_end,    /* ditto, the end of the message */
 339   vtype_msgheaders,     /* the message's headers, processed */
 340   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 341   vtype_localpart,      /* extract local part from string */
 342   vtype_domain,         /* extract domain from string */
 343   vtype_recipients,     /* extract recipients from recipients list */
 344                         /* (enabled only during system filtering */
 345   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 346   vtype_tode,           /* value not used; generate tod in epoch format */
 347   vtype_todf,           /* value not used; generate full tod */
 348   vtype_todl,           /* value not used; generate log tod */
 349   vtype_todlf,          /* value not used; generate log file datestamp tod */
 350   vtype_todzone,        /* value not used; generate time zone only */
 351   vtype_todzulu,        /* value not used; generate zulu tod */
 352   vtype_reply,          /* value not used; get reply from headers */
 353   vtype_pid,            /* value not used; result is pid */
 354   vtype_host_lookup,    /* value not used; get host name */
 355   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 356   vtype_pspace,         /* partition space; value is T/F for spool/log */
 357   vtype_pinodes         /* partition inodes; value is T/F for spool/log */
 358 #ifdef EXPERIMENTAL_DOMAINKEYS
 359  ,vtype_dk_verify       /* Serve request out of DomainKeys verification structure */
 360 #endif
 361   };
 362
 363 /* This table must be kept in alphabetical order. */
 364
 365 static var_entry var_table[] = {
 366   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 367      they will be confused with user-creatable ACL variables. */
 368   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 369   { "address_data",        vtype_stringptr,   &deliver_address_data },
 370   { "address_file",        vtype_stringptr,   &address_file },
 371   { "address_pipe",        vtype_stringptr,   &address_pipe },
 372   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 373   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 374   { "authentication_failed",vtype_int,        &authentication_failed },
 375 #ifdef EXPERIMENTAL_BRIGHTMAIL
 376   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 377   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 378   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 379   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 380 #endif
 381   { "body_linecount",      vtype_int,         &body_linecount },
 382   { "body_zerocount",      vtype_int,         &body_zerocount },
 383   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 384   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 385   { "caller_gid",          vtype_gid,         &real_gid },
 386   { "caller_uid",          vtype_uid,         &real_uid },
 387   { "compile_date",        vtype_stringptr,   &version_date },
 388   { "compile_number",      vtype_stringptr,   &version_cnumber },
 389   { "csa_status",          vtype_stringptr,   &csa_status },
 390 #ifdef WITH_OLD_DEMIME
 391   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 392   { "demime_reason",       vtype_stringptr,   &demime_reason },
 393 #endif
 394 #ifdef EXPERIMENTAL_DOMAINKEYS
 395   { "dk_domain",           vtype_stringptr,   &dk_signing_domain },
 396   { "dk_is_signed",        vtype_dk_verify,   NULL },
 397   { "dk_result",           vtype_dk_verify,   NULL },
 398   { "dk_selector",         vtype_stringptr,   &dk_signing_selector },
 399   { "dk_sender",           vtype_dk_verify,   NULL },
 400   { "dk_sender_domain",    vtype_dk_verify,   NULL },
 401   { "dk_sender_local_part",vtype_dk_verify,   NULL },
 402   { "dk_sender_source",    vtype_dk_verify,   NULL },
 403   { "dk_signsall",         vtype_dk_verify,   NULL },
 404   { "dk_status",           vtype_dk_verify,   NULL },
 405   { "dk_testing",          vtype_dk_verify,   NULL },
 406 #endif
 407   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 408   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 409   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 410   { "domain",              vtype_stringptr,   &deliver_domain },
 411   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 412   { "exim_gid",            vtype_gid,         &exim_gid },
 413   { "exim_path",           vtype_stringptr,   &exim_path },
 414   { "exim_uid",            vtype_uid,         &exim_uid },
 415 #ifdef WITH_OLD_DEMIME
 416   { "found_extension",     vtype_stringptr,   &found_extension },
 417 #endif
 418   { "home",                vtype_stringptr,   &deliver_home },
 419   { "host",                vtype_stringptr,   &deliver_host },
 420   { "host_address",        vtype_stringptr,   &deliver_host_address },
 421   { "host_data",           vtype_stringptr,   &host_data },
 422   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 423   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 424   { "inode",               vtype_ino,         &deliver_inode },
 425   { "interface_address",   vtype_stringptr,   &interface_address },
 426   { "interface_port",      vtype_int,         &interface_port },
 427   { "item",                vtype_stringptr,   &iterate_item },
 428   #ifdef LOOKUP_LDAP
 429   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 430   #endif
 431   { "load_average",        vtype_load_avg,    NULL },
 432   { "local_part",          vtype_stringptr,   &deliver_localpart },
 433   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 434   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 435   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 436   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 437   { "local_user_gid",      vtype_gid,         &local_user_gid },
 438   { "local_user_uid",      vtype_uid,         &local_user_uid },
 439   { "localhost_number",    vtype_int,         &host_number },
 440   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 441   { "log_space",           vtype_pspace,      (void *)FALSE },
 442   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 443 #ifdef WITH_CONTENT_SCAN
 444   { "malware_name",        vtype_stringptr,   &malware_name },
 445 #endif
 446   { "message_age",         vtype_int,         &message_age },
 447   { "message_body",        vtype_msgbody,     &message_body },
 448   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 449   { "message_body_size",   vtype_int,         &message_body_size },
 450   { "message_exim_id",     vtype_stringptr,   &message_id },
 451   { "message_headers",     vtype_msgheaders,  NULL },
 452   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 453   { "message_id",          vtype_stringptr,   &message_id },
 454   { "message_linecount",   vtype_int,         &message_linecount },
 455   { "message_size",        vtype_int,         &message_size },
 456 #ifdef WITH_CONTENT_SCAN
 457   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 458   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 459   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 460   { "mime_charset",        vtype_stringptr,   &mime_charset },
 461   { "mime_content_description", vtype_stringptr, &mime_content_description },
 462   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 463   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 464   { "mime_content_size",   vtype_int,         &mime_content_size },
 465   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 466   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 467   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 468   { "mime_filename",       vtype_stringptr,   &mime_filename },
 469   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 470   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 471   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 472   { "mime_part_count",     vtype_int,         &mime_part_count },
 473 #endif
 474   { "n0",                  vtype_filter_int,  &filter_n[0] },
 475   { "n1",                  vtype_filter_int,  &filter_n[1] },
 476   { "n2",                  vtype_filter_int,  &filter_n[2] },
 477   { "n3",                  vtype_filter_int,  &filter_n[3] },
 478   { "n4",                  vtype_filter_int,  &filter_n[4] },
 479   { "n5",                  vtype_filter_int,  &filter_n[5] },
 480   { "n6",                  vtype_filter_int,  &filter_n[6] },
 481   { "n7",                  vtype_filter_int,  &filter_n[7] },
 482   { "n8",                  vtype_filter_int,  &filter_n[8] },
 483   { "n9",                  vtype_filter_int,  &filter_n[9] },
 484   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 485   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 486   { "originator_gid",      vtype_gid,         &originator_gid },
 487   { "originator_uid",      vtype_uid,         &originator_uid },
 488   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 489   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 490   { "pid",                 vtype_pid,         NULL },
 491   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 492   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 493   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 494   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 495   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 496   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 497   { "rcpt_count",          vtype_int,         &rcpt_count },
 498   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 499   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 500   { "received_count",      vtype_int,         &received_count },
 501   { "received_for",        vtype_stringptr,   &received_for },
 502   { "received_ip_address", vtype_stringptr,   &interface_address },
 503   { "received_port",       vtype_int,         &interface_port },
 504   { "received_protocol",   vtype_stringptr,   &received_protocol },
 505   { "received_time",       vtype_int,         &received_time },
 506   { "recipient_data",      vtype_stringptr,   &recipient_data },
 507   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 508   { "recipients",          vtype_recipients,  NULL },
 509   { "recipients_count",    vtype_int,         &recipients_count },
 510 #ifdef WITH_CONTENT_SCAN
 511   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 512 #endif
 513   { "reply_address",       vtype_reply,       NULL },
 514   { "return_path",         vtype_stringptr,   &return_path },
 515   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 516   { "runrc",               vtype_int,         &runrc },
 517   { "self_hostname",       vtype_stringptr,   &self_hostname },
 518   { "sender_address",      vtype_stringptr,   &sender_address },
 519   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 520   { "sender_address_domain", vtype_domain,    &sender_address },
 521   { "sender_address_local_part", vtype_localpart, &sender_address },
 522   { "sender_data",         vtype_stringptr,   &sender_data },
 523   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 524   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 525   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 526   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 527   { "sender_host_name",    vtype_host_lookup, NULL },
 528   { "sender_host_port",    vtype_int,         &sender_host_port },
 529   { "sender_ident",        vtype_stringptr,   &sender_ident },
 530   { "sender_rate",         vtype_stringptr,   &sender_rate },
 531   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 532   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 533   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 534   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 535   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 536   { "sending_port",        vtype_int,         &sending_port },
 537   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 538   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 539   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 540   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 541   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 542   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 543   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 544   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 545   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 546   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 547   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 548   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 549   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 550   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 551 #ifdef WITH_CONTENT_SCAN
 552   { "spam_bar",            vtype_stringptr,   &spam_bar },
 553   { "spam_report",         vtype_stringptr,   &spam_report },
 554   { "spam_score",          vtype_stringptr,   &spam_score },
 555   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 556 #endif
 557 #ifdef EXPERIMENTAL_SPF
 558   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 559   { "spf_received",        vtype_stringptr,   &spf_received },
 560   { "spf_result",          vtype_stringptr,   &spf_result },
 561   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 562 #endif
 563   { "spool_directory",     vtype_stringptr,   &spool_directory },
 564   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 565   { "spool_space",         vtype_pspace,      (void *)TRUE },
 566 #ifdef EXPERIMENTAL_SRS
 567   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 568   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 569   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 570   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 571   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 572   { "srs_status",          vtype_stringptr,   &srs_status },
 573 #endif
 574   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 575   { "tls_certificate_verified", vtype_int,    &tls_certificate_verified },
 576   { "tls_cipher",          vtype_stringptr,   &tls_cipher },
 577   { "tls_peerdn",          vtype_stringptr,   &tls_peerdn },
 578   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 579   { "tod_epoch",           vtype_tode,        NULL },
 580   { "tod_full",            vtype_todf,        NULL },
 581   { "tod_log",             vtype_todl,        NULL },
 582   { "tod_logfile",         vtype_todlf,       NULL },
 583   { "tod_zone",            vtype_todzone,     NULL },
 584   { "tod_zulu",            vtype_todzulu,     NULL },
 585   { "value",               vtype_stringptr,   &lookup_value },
 586   { "version_number",      vtype_stringptr,   &version_string },
 587   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 588   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 589   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 590   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 591   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 592   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 593 };
 594
 595 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
 596 static uschar var_buffer[256];
 597 static BOOL malformed_header;
 598
 599 /* For textual hashes */
 600
 601 static char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 602                          "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 603                          "0123456789";
 604
 605 enum { HMAC_MD5, HMAC_SHA1 };
 606
 607 /* For numeric hashes */
 608
 609 static unsigned int prime[] = {
 610   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 611  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 612  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 613
 614 /* For printing modes in symbolic form */
 615
 616 static uschar *mtable_normal[] =
 617   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 618
 619 static uschar *mtable_setid[] =
 620   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 621
 622 static uschar *mtable_sticky[] =
 623   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 624
 625
 626
 627 /*************************************************
 628 *           Tables for UTF-8 support             *
 629 *************************************************/
 630
 631 /* Table of the number of extra characters, indexed by the first character
 632 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 633 0x3d. */
 634
 635 static uschar utf8_table1[] = {
 636   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 637   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 638   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 639   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 640
 641 /* These are the masks for the data bits in the first byte of a character,
 642 indexed by the number of additional bytes. */
 643
 644 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 645
 646 /* Get the next UTF-8 character, advancing the pointer. */
 647
 648 #define GETUTF8INC(c, ptr) \
 649   c = *ptr++; \
 650   if ((c & 0xc0) == 0xc0) \
 651     { \
 652     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 653     int s = 6*a; \
 654     c = (c & utf8_table2[a]) << s; \
 655     while (a-- > 0) \
 656       { \
 657       s -= 6; \
 658       c |= (*ptr++ & 0x3f) << s; \
 659       } \
 660     }
 661
 662
 663 /*************************************************
 664 *           Binary chop search on a table        *
 665 *************************************************/
 666
 667 /* This is used for matching expansion items and operators.
 668
 669 Arguments:
 670   name        the name that is being sought
 671   table       the table to search
 672   table_size  the number of items in the table
 673
 674 Returns:      the offset in the table, or -1
 675 */
 676
 677 static int
 678 chop_match(uschar *name, uschar **table, int table_size)
 679 {
 680 uschar **bot = table;
 681 uschar **top = table + table_size;
 682
 683 while (top > bot)
 684   {
 685   uschar **mid = bot + (top - bot)/2;
 686   int c = Ustrcmp(name, *mid);
 687   if (c == 0) return mid - table;
 688   if (c > 0) bot = mid + 1; else top = mid;
 689   }
 690
 691 return -1;
 692 }
 693
 694
 695
 696 /*************************************************
 697 *          Check a condition string              *
 698 *************************************************/
 699
 700 /* This function is called to expand a string, and test the result for a "true"
 701 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 702 forced fail or lookup defer. All store used by the function can be released on
 703 exit.
 704
 705 Arguments:
 706   condition     the condition string
 707   m1            text to be incorporated in panic error
 708   m2            ditto
 709
 710 Returns:        TRUE if condition is met, FALSE if not
 711 */
 712
 713 BOOL
 714 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 715 {
 716 int rc;
 717 void *reset_point = store_get(0);
 718 uschar *ss = expand_string(condition);
 719 if (ss == NULL)
 720   {
 721   if (!expand_string_forcedfail && !search_find_defer)
 722     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 723       "for %s %s: %s", condition, m1, m2, expand_string_message);
 724   return FALSE;
 725   }
 726 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 727   strcmpic(ss, US"false") != 0;
 728 store_reset(reset_point);
 729 return rc;
 730 }
 731
 732
 733
 734 /*************************************************
 735 *             Pick out a name from a string      *
 736 *************************************************/
 737
 738 /* If the name is too long, it is silently truncated.
 739
 740 Arguments:
 741   name      points to a buffer into which to put the name
 742   max       is the length of the buffer
 743   s         points to the first alphabetic character of the name
 744   extras    chars other than alphanumerics to permit
 745
 746 Returns:    pointer to the first character after the name
 747
 748 Note: The test for *s != 0 in the while loop is necessary because
 749 Ustrchr() yields non-NULL if the character is zero (which is not something
 750 I expected). */
 751
 752 static uschar *
 753 read_name(uschar *name, int max, uschar *s, uschar *extras)
 754 {
 755 int ptr = 0;
 756 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 757   {
 758   if (ptr < max-1) name[ptr++] = *s;
 759   s++;
 760   }
 761 name[ptr] = 0;
 762 return s;
 763 }
 764
 765
 766
 767 /*************************************************
 768 *     Pick out the rest of a header name         *
 769 *************************************************/
 770
 771 /* A variable name starting $header_ (or just $h_ for those who like
 772 abbreviations) might not be the complete header name because headers can
 773 contain any printing characters in their names, except ':'. This function is
 774 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 775 on the end, if the name was terminated by white space.
 776
 777 Arguments:
 778   name      points to a buffer in which the name read so far exists
 779   max       is the length of the buffer
 780   s         points to the first character after the name so far, i.e. the
 781             first non-alphameric character after $header_xxxxx
 782
 783 Returns:    a pointer to the first character after the header name
 784 */
 785
 786 static uschar *
 787 read_header_name(uschar *name, int max, uschar *s)
 788 {
 789 int prelen = Ustrchr(name, '_') - name + 1;
 790 int ptr = Ustrlen(name) - prelen;
 791 if (ptr > 0) memmove(name, name+prelen, ptr);
 792 while (mac_isgraph(*s) && *s != ':')
 793   {
 794   if (ptr < max-1) name[ptr++] = *s;
 795   s++;
 796   }
 797 if (*s == ':') s++;
 798 name[ptr++] = ':';
 799 name[ptr] = 0;
 800 return s;
 801 }
 802
 803
 804
 805 /*************************************************
 806 *           Pick out a number from a string      *
 807 *************************************************/
 808
 809 /* Arguments:
 810   n     points to an integer into which to put the number
 811   s     points to the first digit of the number
 812
 813 Returns:  a pointer to the character after the last digit
 814 */
 815
 816 static uschar *
 817 read_number(int *n, uschar *s)
 818 {
 819 *n = 0;
 820 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
 821 return s;
 822 }
 823
 824
 825
 826 /*************************************************
 827 *        Extract keyed subfield from a string    *
 828 *************************************************/
 829
 830 /* The yield is in dynamic store; NULL means that the key was not found.
 831
 832 Arguments:
 833   key       points to the name of the key
 834   s         points to the string from which to extract the subfield
 835
 836 Returns:    NULL if the subfield was not found, or
 837             a pointer to the subfield's data
 838 */
 839
 840 static uschar *
 841 expand_getkeyed(uschar *key, uschar *s)
 842 {
 843 int length = Ustrlen(key);
 844 while (isspace(*s)) s++;
 845
 846 /* Loop to search for the key */
 847
 848 while (*s != 0)
 849   {
 850   int dkeylength;
 851   uschar *data;
 852   uschar *dkey = s;
 853
 854   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
 855   dkeylength = s - dkey;
 856   while (isspace(*s)) s++;
 857   if (*s == '=') while (isspace((*(++s))));
 858
 859   data = string_dequote(&s);
 860   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
 861     return data;
 862
 863   while (isspace(*s)) s++;
 864   }
 865
 866 return NULL;
 867 }
 868
 869
 870
 871
 872 /*************************************************
 873 *   Extract numbered subfield from string        *
 874 *************************************************/
 875
 876 /* Extracts a numbered field from a string that is divided by tokens - for
 877 example a line from /etc/passwd is divided by colon characters.  First field is
 878 numbered one.  Negative arguments count from the right. Zero returns the whole
 879 string. Returns NULL if there are insufficient tokens in the string
 880
 881 ***WARNING***
 882 Modifies final argument - this is a dynamically generated string, so that's OK.
 883
 884 Arguments:
 885   field       number of field to be extracted,
 886                 first field = 1, whole string = 0, last field = -1
 887   separators  characters that are used to break string into tokens
 888   s           points to the string from which to extract the subfield
 889
 890 Returns:      NULL if the field was not found,
 891               a pointer to the field's data inside s (modified to add 0)
 892 */
 893
 894 static uschar *
 895 expand_gettokened (int field, uschar *separators, uschar *s)
 896 {
 897 int sep = 1;
 898 int count;
 899 uschar *ss = s;
 900 uschar *fieldtext = NULL;
 901
 902 if (field == 0) return s;
 903
 904 /* Break the line up into fields in place; for field > 0 we stop when we have
 905 done the number of fields we want. For field < 0 we continue till the end of
 906 the string, counting the number of fields. */
 907
 908 count = (field > 0)? field : INT_MAX;
 909
 910 while (count-- > 0)
 911   {
 912   size_t len;
 913
 914   /* Previous field was the last one in the string. For a positive field
 915   number, this means there are not enough fields. For a negative field number,
 916   check that there are enough, and scan back to find the one that is wanted. */
 917
 918   if (sep == 0)
 919     {
 920     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
 921     if ((-field) == (INT_MAX - count - 1)) return s;
 922     while (field++ < 0)
 923       {
 924       ss--;
 925       while (ss[-1] != 0) ss--;
 926       }
 927     fieldtext = ss;
 928     break;
 929     }
 930
 931   /* Previous field was not last in the string; save its start and put a
 932   zero at its end. */
 933
 934   fieldtext = ss;
 935   len = Ustrcspn(ss, separators);
 936   sep = ss[len];
 937   ss[len] = 0;
 938   ss += len + 1;
 939   }
 940
 941 return fieldtext;
 942 }
 943
 944
 945
 946 /*************************************************
 947 *        Extract a substring from a string       *
 948 *************************************************/
 949
 950 /* Perform the ${substr or ${length expansion operations.
 951
 952 Arguments:
 953   subject     the input string
 954   value1      the offset from the start of the input string to the start of
 955                 the output string; if negative, count from the right.
 956   value2      the length of the output string, or negative (-1) for unset
 957                 if value1 is positive, unset means "all after"
 958                 if value1 is negative, unset means "all before"
 959   len         set to the length of the returned string
 960
 961 Returns:      pointer to the output string, or NULL if there is an error
 962 */
 963
 964 static uschar *
 965 extract_substr(uschar *subject, int value1, int value2, int *len)
 966 {
 967 int sublen = Ustrlen(subject);
 968
 969 if (value1 < 0)    /* count from right */
 970   {
 971   value1 += sublen;
 972
 973   /* If the position is before the start, skip to the start, and adjust the
 974   length. If the length ends up negative, the substring is null because nothing
 975   can precede. This falls out naturally when the length is unset, meaning "all
 976   to the left". */
 977
 978   if (value1 < 0)
 979     {
 980     value2 += value1;
 981     if (value2 < 0) value2 = 0;
 982     value1 = 0;
 983     }
 984
 985   /* Otherwise an unset length => characters before value1 */
 986
 987   else if (value2 < 0)
 988     {
 989     value2 = value1;
 990     value1 = 0;
 991     }
 992   }
 993
 994 /* For a non-negative offset, if the starting position is past the end of the
 995 string, the result will be the null string. Otherwise, an unset length means
 996 "rest"; just set it to the maximum - it will be cut down below if necessary. */
 997
 998 else
 999   {
1000   if (value1 > sublen)
1001     {
1002     value1 = sublen;
1003     value2 = 0;
1004     }
1005   else if (value2 < 0) value2 = sublen;
1006   }
1007
1008 /* Cut the length down to the maximum possible for the offset value, and get
1009 the required characters. */
1010
1011 if (value1 + value2 > sublen) value2 = sublen - value1;
1012 *len = value2;
1013 return subject + value1;
1014 }
1015
1016
1017
1018
1019 /*************************************************
1020 *            Old-style hash of a string          *
1021 *************************************************/
1022
1023 /* Perform the ${hash expansion operation.
1024
1025 Arguments:
1026   subject     the input string (an expanded substring)
1027   value1      the length of the output string; if greater or equal to the
1028                 length of the input string, the input string is returned
1029   value2      the number of hash characters to use, or 26 if negative
1030   len         set to the length of the returned string
1031
1032 Returns:      pointer to the output string, or NULL if there is an error
1033 */
1034
1035 static uschar *
1036 compute_hash(uschar *subject, int value1, int value2, int *len)
1037 {
1038 int sublen = Ustrlen(subject);
1039
1040 if (value2 < 0) value2 = 26;
1041 else if (value2 > Ustrlen(hashcodes))
1042   {
1043   expand_string_message =
1044     string_sprintf("hash count \"%d\" too big", value2);
1045   return NULL;
1046   }
1047
1048 /* Calculate the hash text. We know it is shorter than the original string, so
1049 can safely place it in subject[] (we know that subject is always itself an
1050 expanded substring). */
1051
1052 if (value1 < sublen)
1053   {
1054   int c;
1055   int i = 0;
1056   int j = value1;
1057   while ((c = (subject[j])) != 0)
1058     {
1059     int shift = (c + j++) & 7;
1060     subject[i] ^= (c << shift) | (c >> (8-shift));
1061     if (++i >= value1) i = 0;
1062     }
1063   for (i = 0; i < value1; i++)
1064     subject[i] = hashcodes[(subject[i]) % value2];
1065   }
1066 else value1 = sublen;
1067
1068 *len = value1;
1069 return subject;
1070 }
1071
1072
1073
1074
1075 /*************************************************
1076 *             Numeric hash of a string           *
1077 *************************************************/
1078
1079 /* Perform the ${nhash expansion operation. The first characters of the
1080 string are treated as most important, and get the highest prime numbers.
1081
1082 Arguments:
1083   subject     the input string
1084   value1      the maximum value of the first part of the result
1085   value2      the maximum value of the second part of the result,
1086                 or negative to produce only a one-part result
1087   len         set to the length of the returned string
1088
1089 Returns:  pointer to the output string, or NULL if there is an error.
1090 */
1091
1092 static uschar *
1093 compute_nhash (uschar *subject, int value1, int value2, int *len)
1094 {
1095 uschar *s = subject;
1096 int i = 0;
1097 unsigned long int total = 0; /* no overflow */
1098
1099 while (*s != 0)
1100   {
1101   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1102   total += prime[i--] * (unsigned int)(*s++);
1103   }
1104
1105 /* If value2 is unset, just compute one number */
1106
1107 if (value2 < 0)
1108   {
1109   s = string_sprintf("%d", total % value1);
1110   }
1111
1112 /* Otherwise do a div/mod hash */
1113
1114 else
1115   {
1116   total = total % (value1 * value2);
1117   s = string_sprintf("%d/%d", total/value2, total % value2);
1118   }
1119
1120 *len = Ustrlen(s);
1121 return s;
1122 }
1123
1124
1125
1126
1127
1128 /*************************************************
1129 *     Find the value of a header or headers      *
1130 *************************************************/
1131
1132 /* Multiple instances of the same header get concatenated, and this function
1133 can also return a concatenation of all the header lines. When concatenating
1134 specific headers that contain lists of addresses, a comma is inserted between
1135 them. Otherwise we use a straight concatenation. Because some messages can have
1136 pathologically large number of lines, there is a limit on the length that is
1137 returned. Also, to avoid massive store use which would result from using
1138 string_cat() as it copies and extends strings, we do a preliminary pass to find
1139 out exactly how much store will be needed. On "normal" messages this will be
1140 pretty trivial.
1141
1142 Arguments:
1143   name          the name of the header, without the leading $header_ or $h_,
1144                 or NULL if a concatenation of all headers is required
1145   exists_only   TRUE if called from a def: test; don't need to build a string;
1146                 just return a string that is not "" and not "0" if the header
1147                 exists
1148   newsize       return the size of memory block that was obtained; may be NULL
1149                 if exists_only is TRUE
1150   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1151                 other than concatenating, will be done on the header. Also used
1152                 for $message_headers_raw.
1153   charset       name of charset to translate MIME words to; used only if
1154                 want_raw is false; if NULL, no translation is done (this is
1155                 used for $bh_ and $bheader_)
1156
1157 Returns:        NULL if the header does not exist, else a pointer to a new
1158                 store block
1159 */
1160
1161 static uschar *
1162 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1163   uschar *charset)
1164 {
1165 BOOL found = name == NULL;
1166 int comma = 0;
1167 int len = found? 0 : Ustrlen(name);
1168 int i;
1169 uschar *yield = NULL;
1170 uschar *ptr = NULL;
1171
1172 /* Loop for two passes - saves code repetition */
1173
1174 for (i = 0; i < 2; i++)
1175   {
1176   int size = 0;
1177   header_line *h;
1178
1179   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1180     {
1181     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1182       {
1183       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1184         {
1185         int ilen;
1186         uschar *t;
1187
1188         if (exists_only) return US"1";      /* don't need actual string */
1189         found = TRUE;
1190         t = h->text + len;                  /* text to insert */
1191         if (!want_raw)                      /* unless wanted raw, */
1192           while (isspace(*t)) t++;          /* remove leading white space */
1193         ilen = h->slen - (t - h->text);     /* length to insert */
1194
1195         /* Unless wanted raw, remove trailing whitespace, including the
1196         newline. */
1197
1198         if (!want_raw)
1199           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1200
1201         /* Set comma = 1 if handling a single header and it's one of those
1202         that contains an address list, except when asked for raw headers. Only
1203         need to do this once. */
1204
1205         if (!want_raw && name != NULL && comma == 0 &&
1206             Ustrchr("BCFRST", h->type) != NULL)
1207           comma = 1;
1208
1209         /* First pass - compute total store needed; second pass - compute
1210         total store used, including this header. */
1211
1212         size += ilen + comma + 1;  /* +1 for the newline */
1213
1214         /* Second pass - concatentate the data, up to a maximum. Note that
1215         the loop stops when size hits the limit. */
1216
1217         if (i != 0)
1218           {
1219           if (size > header_insert_maxlen)
1220             {
1221             ilen -= size - header_insert_maxlen - 1;
1222             comma = 0;
1223             }
1224           Ustrncpy(ptr, t, ilen);
1225           ptr += ilen;
1226
1227           /* For a non-raw header, put in the comma if needed, then add
1228           back the newline we removed above, provided there was some text in
1229           the header. */
1230
1231           if (!want_raw && ilen > 0)
1232             {
1233             if (comma != 0) *ptr++ = ',';
1234             *ptr++ = '\n';
1235             }
1236           }
1237         }
1238       }
1239     }
1240
1241   /* At end of first pass, return NULL if no header found. Then truncate size
1242   if necessary, and get the buffer to hold the data, returning the buffer size.
1243   */
1244
1245   if (i == 0)
1246     {
1247     if (!found) return NULL;
1248     if (size > header_insert_maxlen) size = header_insert_maxlen;
1249     *newsize = size + 1;
1250     ptr = yield = store_get(*newsize);
1251     }
1252   }
1253
1254 /* That's all we do for raw header expansion. */
1255
1256 if (want_raw)
1257   {
1258   *ptr = 0;
1259   }
1260
1261 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1262 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1263 function can return an error with decoded data if the charset translation
1264 fails. If decoding fails, it returns NULL. */
1265
1266 else
1267   {
1268   uschar *decoded, *error;
1269   if (ptr > yield && ptr[-1] == '\n') ptr--;
1270   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1271   *ptr = 0;
1272   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1273     newsize, &error);
1274   if (error != NULL)
1275     {
1276     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1277       "    input was: %s\n", error, yield);
1278     }
1279   if (decoded != NULL) yield = decoded;
1280   }
1281
1282 return yield;
1283 }
1284
1285
1286
1287
1288 /*************************************************
1289 *               Find value of a variable         *
1290 *************************************************/
1291
1292 /* The table of variables is kept in alphabetic order, so we can search it
1293 using a binary chop. The "choplen" variable is nothing to do with the binary
1294 chop.
1295
1296 Arguments:
1297   name          the name of the variable being sought
1298   exists_only   TRUE if this is a def: test; passed on to find_header()
1299   skipping      TRUE => skip any processing evaluation; this is not the same as
1300                   exists_only because def: may test for values that are first
1301                   evaluated here
1302   newsize       pointer to an int which is initially zero; if the answer is in
1303                 a new memory buffer, *newsize is set to its size
1304
1305 Returns:        NULL if the variable does not exist, or
1306                 a pointer to the variable's contents, or
1307                 something non-NULL if exists_only is TRUE
1308 */
1309
1310 static uschar *
1311 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1312 {
1313 int first = 0;
1314 int last = var_table_size;
1315
1316 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1317 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1318 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1319 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1320 (this gave backwards compatibility at the changeover). There may be built-in
1321 variables whose names start acl_ but they should never start in this way. This
1322 slightly messy specification is a consequence of the history, needless to say.
1323
1324 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1325 set, in which case give an error. */
1326
1327 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1328      !isalpha(name[5]))
1329   {
1330   tree_node *node =
1331     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1332   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1333   }
1334
1335 /* Handle $auth<n> variables. */
1336
1337 if (Ustrncmp(name, "auth", 4) == 0)
1338   {
1339   uschar *endptr;
1340   int n = Ustrtoul(name + 4, &endptr, 10);
1341   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1342     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1343   }
1344
1345 /* For all other variables, search the table */
1346
1347 while (last > first)
1348   {
1349   uschar *s, *domain;
1350   uschar **ss;
1351   int middle = (first + last)/2;
1352   int c = Ustrcmp(name, var_table[middle].name);
1353
1354   if (c > 0) { first = middle + 1; continue; }
1355   if (c < 0) { last = middle; continue; }
1356
1357   /* Found an existing variable. If in skipping state, the value isn't needed,
1358   and we want to avoid processing (such as looking up the host name). */
1359
1360   if (skipping) return US"";
1361
1362   switch (var_table[middle].type)
1363     {
1364 #ifdef EXPERIMENTAL_DOMAINKEYS
1365
1366     case vtype_dk_verify:
1367     if (dk_verify_block == NULL) return US"";
1368     s = NULL;
1369     if (Ustrcmp(var_table[middle].name, "dk_result") == 0)
1370       s = dk_verify_block->result_string;
1371     if (Ustrcmp(var_table[middle].name, "dk_sender") == 0)
1372       s = dk_verify_block->address;
1373     if (Ustrcmp(var_table[middle].name, "dk_sender_domain") == 0)
1374       s = dk_verify_block->domain;
1375     if (Ustrcmp(var_table[middle].name, "dk_sender_local_part") == 0)
1376       s = dk_verify_block->local_part;
1377
1378     if (Ustrcmp(var_table[middle].name, "dk_sender_source") == 0)
1379       switch(dk_verify_block->address_source) {
1380         case DK_EXIM_ADDRESS_NONE: s = US"0"; break;
1381         case DK_EXIM_ADDRESS_FROM_FROM: s = US"from"; break;
1382         case DK_EXIM_ADDRESS_FROM_SENDER: s = US"sender"; break;
1383       }
1384
1385     if (Ustrcmp(var_table[middle].name, "dk_status") == 0)
1386       switch(dk_verify_block->result) {
1387         case DK_EXIM_RESULT_ERR: s = US"error"; break;
1388         case DK_EXIM_RESULT_BAD_FORMAT: s = US"bad format"; break;
1389         case DK_EXIM_RESULT_NO_KEY: s = US"no key"; break;
1390         case DK_EXIM_RESULT_NO_SIGNATURE: s = US"no signature"; break;
1391         case DK_EXIM_RESULT_REVOKED: s = US"revoked"; break;
1392         case DK_EXIM_RESULT_NON_PARTICIPANT: s = US"non-participant"; break;
1393         case DK_EXIM_RESULT_GOOD: s = US"good"; break;
1394         case DK_EXIM_RESULT_BAD: s = US"bad"; break;
1395       }
1396
1397     if (Ustrcmp(var_table[middle].name, "dk_signsall") == 0)
1398       s = (dk_verify_block->signsall)? US"1" : US"0";
1399
1400     if (Ustrcmp(var_table[middle].name, "dk_testing") == 0)
1401       s = (dk_verify_block->testing)? US"1" : US"0";
1402
1403     if (Ustrcmp(var_table[middle].name, "dk_is_signed") == 0)
1404       s = (dk_verify_block->is_signed)? US"1" : US"0";
1405
1406     return (s == NULL)? US"" : s;
1407 #endif
1408
1409     case vtype_filter_int:
1410     if (!filter_running) return NULL;
1411     /* Fall through */
1412     /* VVVVVVVVVVVV */
1413     case vtype_int:
1414     sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1415     return var_buffer;
1416
1417     case vtype_ino:
1418     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1419     return var_buffer;
1420
1421     case vtype_gid:
1422     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1423     return var_buffer;
1424
1425     case vtype_uid:
1426     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1427     return var_buffer;
1428
1429     case vtype_stringptr:                      /* Pointer to string */
1430     s = *((uschar **)(var_table[middle].value));
1431     return (s == NULL)? US"" : s;
1432
1433     case vtype_pid:
1434     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1435     return var_buffer;
1436
1437     case vtype_load_avg:
1438     sprintf(CS var_buffer, "%d", os_getloadavg()); /* load_average */
1439     return var_buffer;
1440
1441     case vtype_host_lookup:                    /* Lookup if not done so */
1442     if (sender_host_name == NULL && sender_host_address != NULL &&
1443         !host_lookup_failed && host_name_lookup() == OK)
1444       host_build_sender_fullhost();
1445     return (sender_host_name == NULL)? US"" : sender_host_name;
1446
1447     case vtype_localpart:                      /* Get local part from address */
1448     s = *((uschar **)(var_table[middle].value));
1449     if (s == NULL) return US"";
1450     domain = Ustrrchr(s, '@');
1451     if (domain == NULL) return s;
1452     if (domain - s > sizeof(var_buffer) - 1)
1453       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than %d in "
1454         "string expansion", sizeof(var_buffer));
1455     Ustrncpy(var_buffer, s, domain - s);
1456     var_buffer[domain - s] = 0;
1457     return var_buffer;
1458
1459     case vtype_domain:                         /* Get domain from address */
1460     s = *((uschar **)(var_table[middle].value));
1461     if (s == NULL) return US"";
1462     domain = Ustrrchr(s, '@');
1463     return (domain == NULL)? US"" : domain + 1;
1464
1465     case vtype_msgheaders:
1466     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1467
1468     case vtype_msgheaders_raw:
1469     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1470
1471     case vtype_msgbody:                        /* Pointer to msgbody string */
1472     case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1473     ss = (uschar **)(var_table[middle].value);
1474     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1475       {
1476       uschar *body;
1477       off_t start_offset = SPOOL_DATA_START_OFFSET;
1478       int len = message_body_visible;
1479       if (len > message_size) len = message_size;
1480       *ss = body = store_malloc(len+1);
1481       body[0] = 0;
1482       if (var_table[middle].type == vtype_msgbody_end)
1483         {
1484         struct stat statbuf;
1485         if (fstat(deliver_datafile, &statbuf) == 0)
1486           {
1487           start_offset = statbuf.st_size - len;
1488           if (start_offset < SPOOL_DATA_START_OFFSET)
1489             start_offset = SPOOL_DATA_START_OFFSET;
1490           }
1491         }
1492       lseek(deliver_datafile, start_offset, SEEK_SET);
1493       len = read(deliver_datafile, body, len);
1494       if (len > 0)
1495         {
1496         body[len] = 0;
1497         while (len > 0)
1498           {
1499           if (body[--len] == '\n' || body[len] == 0) body[len] = ' ';
1500           }
1501         }
1502       }
1503     return (*ss == NULL)? US"" : *ss;
1504
1505     case vtype_todbsdin:                       /* BSD inbox time of day */
1506     return tod_stamp(tod_bsdin);
1507
1508     case vtype_tode:                           /* Unix epoch time of day */
1509     return tod_stamp(tod_epoch);
1510
1511     case vtype_todf:                           /* Full time of day */
1512     return tod_stamp(tod_full);
1513
1514     case vtype_todl:                           /* Log format time of day */
1515     return tod_stamp(tod_log_bare);            /* (without timezone) */
1516
1517     case vtype_todzone:                        /* Time zone offset only */
1518     return tod_stamp(tod_zone);
1519
1520     case vtype_todzulu:                        /* Zulu time */
1521     return tod_stamp(tod_zulu);
1522
1523     case vtype_todlf:                          /* Log file datestamp tod */
1524     return tod_stamp(tod_log_datestamp);
1525
1526     case vtype_reply:                          /* Get reply address */
1527     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1528       headers_charset);
1529     if (s != NULL) while (isspace(*s)) s++;
1530     if (s == NULL || *s == 0)
1531       {
1532       *newsize = 0;                            /* For the *s==0 case */
1533       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1534       }
1535     if (s != NULL)
1536       {
1537       uschar *t;
1538       while (isspace(*s)) s++;
1539       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1540       while (t > s && isspace(t[-1])) t--;
1541       *t = 0;
1542       }
1543     return (s == NULL)? US"" : s;
1544
1545     /* A recipients list is available only during system message filtering,
1546     during ACL processing after DATA, and while expanding pipe commands
1547     generated from a system filter, but not elsewhere. */
1548
1549     case vtype_recipients:
1550     if (!enable_dollar_recipients) return NULL; else
1551       {
1552       int size = 128;
1553       int ptr = 0;
1554       int i;
1555       s = store_get(size);
1556       for (i = 0; i < recipients_count; i++)
1557         {
1558         if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1559         s = string_cat(s, &size, &ptr, recipients_list[i].address,
1560           Ustrlen(recipients_list[i].address));
1561         }
1562       s[ptr] = 0;     /* string_cat() leaves room */
1563       }
1564     return s;
1565
1566     case vtype_pspace:
1567       {
1568       int inodes;
1569       sprintf(CS var_buffer, "%d",
1570         receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes));
1571       }
1572     return var_buffer;
1573
1574     case vtype_pinodes:
1575       {
1576       int inodes;
1577       (void) receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes);
1578       sprintf(CS var_buffer, "%d", inodes);
1579       }
1580     return var_buffer;
1581     }
1582   }
1583
1584 return NULL;          /* Unknown variable name */
1585 }
1586
1587
1588
1589
1590 /*************************************************
1591 *           Read and expand substrings           *
1592 *************************************************/
1593
1594 /* This function is called to read and expand argument substrings for various
1595 expansion items. Some have a minimum requirement that is less than the maximum;
1596 in these cases, the first non-present one is set to NULL.
1597
1598 Arguments:
1599   sub        points to vector of pointers to set
1600   n          maximum number of substrings
1601   m          minimum required
1602   sptr       points to current string pointer
1603   skipping   the skipping flag
1604   check_end  if TRUE, check for final '}'
1605   name       name of item, for error message
1606
1607 Returns:     0 OK; string pointer updated
1608              1 curly bracketing error (too few arguments)
1609              2 too many arguments (only if check_end is set); message set
1610              3 other error (expansion failure)
1611 */
1612
1613 static int
1614 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1615   BOOL check_end, uschar *name)
1616 {
1617 int i;
1618 uschar *s = *sptr;
1619
1620 while (isspace(*s)) s++;
1621 for (i = 0; i < n; i++)
1622   {
1623   if (*s != '{')
1624     {
1625     if (i < m) return 1;
1626     sub[i] = NULL;
1627     break;
1628     }
1629   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping);
1630   if (sub[i] == NULL) return 3;
1631   if (*s++ != '}') return 1;
1632   while (isspace(*s)) s++;
1633   }
1634 if (check_end && *s++ != '}')
1635   {
1636   if (s[-1] == '{')
1637     {
1638     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1639       "(max is %d)", name, n);
1640     return 2;
1641     }
1642   return 1;
1643   }
1644
1645 *sptr = s;
1646 return 0;
1647 }
1648
1649
1650
1651
1652 /*************************************************
1653 *     Elaborate message for bad variable         *
1654 *************************************************/
1655
1656 /* For the "unknown variable" message, take a look at the variable's name, and
1657 give additional information about possible ACL variables. The extra information
1658 is added on to expand_string_message.
1659
1660 Argument:   the name of the variable
1661 Returns:    nothing
1662 */
1663
1664 static void
1665 check_variable_error_message(uschar *name)
1666 {
1667 if (Ustrncmp(name, "acl_", 4) == 0)
1668   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1669     (name[4] == 'c' || name[4] == 'm')?
1670       (isalpha(name[5])?
1671         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1672         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1673       ) :
1674       US"user-defined ACL variables must start acl_c or acl_m");
1675 }
1676
1677
1678
1679 /*************************************************
1680 *        Read and evaluate a condition           *
1681 *************************************************/
1682
1683 /*
1684 Arguments:
1685   s        points to the start of the condition text
1686   yield    points to a BOOL to hold the result of the condition test;
1687            if NULL, we are just reading through a condition that is
1688            part of an "or" combination to check syntax, or in a state
1689            where the answer isn't required
1690
1691 Returns:   a pointer to the first character after the condition, or
1692            NULL after an error
1693 */
1694
1695 static uschar *
1696 eval_condition(uschar *s, BOOL *yield)
1697 {
1698 BOOL testfor = TRUE;
1699 BOOL tempcond, combined_cond;
1700 BOOL *subcondptr;
1701 int i, rc, cond_type, roffset;
1702 int num[2];
1703 struct stat statbuf;
1704 uschar name[256];
1705 uschar *sub[4];
1706
1707 const pcre *re;
1708 const uschar *rerror;
1709
1710 for (;;)
1711   {
1712   while (isspace(*s)) s++;
1713   if (*s == '!') { testfor = !testfor; s++; } else break;
1714   }
1715
1716 /* Numeric comparisons are symbolic */
1717
1718 if (*s == '=' || *s == '>' || *s == '<')
1719   {
1720   int p = 0;
1721   name[p++] = *s++;
1722   if (*s == '=')
1723     {
1724     name[p++] = '=';
1725     s++;
1726     }
1727   name[p] = 0;
1728   }
1729
1730 /* All other conditions are named */
1731
1732 else s = read_name(name, 256, s, US"_");
1733
1734 /* If we haven't read a name, it means some non-alpha character is first. */
1735
1736 if (name[0] == 0)
1737   {
1738   expand_string_message = string_sprintf("condition name expected, "
1739     "but found \"%.16s\"", s);
1740   return NULL;
1741   }
1742
1743 /* Find which condition we are dealing with, and switch on it */
1744
1745 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1746 switch(cond_type)
1747   {
1748   /* def: tests for a non-empty variable, or for the existence of a header. If
1749   yield == NULL we are in a skipping state, and don't care about the answer. */
1750
1751   case ECOND_DEF:
1752   if (*s != ':')
1753     {
1754     expand_string_message = US"\":\" expected after \"def\"";
1755     return NULL;
1756     }
1757
1758   s = read_name(name, 256, s+1, US"_");
1759
1760   /* Test for a header's existence. If the name contains a closing brace
1761   character, this may be a user error where the terminating colon has been
1762   omitted. Set a flag to adjust a subsequent error message in this case. */
1763
1764   if (Ustrncmp(name, "h_", 2) == 0 ||
1765       Ustrncmp(name, "rh_", 3) == 0 ||
1766       Ustrncmp(name, "bh_", 3) == 0 ||
1767       Ustrncmp(name, "header_", 7) == 0 ||
1768       Ustrncmp(name, "rheader_", 8) == 0 ||
1769       Ustrncmp(name, "bheader_", 8) == 0)
1770     {
1771     s = read_header_name(name, 256, s);
1772     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
1773     if (yield != NULL) *yield =
1774       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1775     }
1776
1777   /* Test for a variable's having a non-empty value. A non-existent variable
1778   causes an expansion failure. */
1779
1780   else
1781     {
1782     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1783     if (value == NULL)
1784       {
1785       expand_string_message = (name[0] == 0)?
1786         string_sprintf("variable name omitted after \"def:\"") :
1787         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1788       check_variable_error_message(name);
1789       return NULL;
1790       }
1791     if (yield != NULL) *yield = (value[0] != 0) == testfor;
1792     }
1793
1794   return s;
1795
1796
1797   /* first_delivery tests for first delivery attempt */
1798
1799   case ECOND_FIRST_DELIVERY:
1800   if (yield != NULL) *yield = deliver_firsttime == testfor;
1801   return s;
1802
1803
1804   /* queue_running tests for any process started by a queue runner */
1805
1806   case ECOND_QUEUE_RUNNING:
1807   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
1808   return s;
1809
1810
1811   /* exists:  tests for file existence
1812        isip:  tests for any IP address
1813       isip4:  tests for an IPv4 address
1814       isip6:  tests for an IPv6 address
1815         pam:  does PAM authentication
1816      radius:  does RADIUS authentication
1817    ldapauth:  does LDAP authentication
1818     pwcheck:  does Cyrus SASL pwcheck authentication
1819   */
1820
1821   case ECOND_EXISTS:
1822   case ECOND_ISIP:
1823   case ECOND_ISIP4:
1824   case ECOND_ISIP6:
1825   case ECOND_PAM:
1826   case ECOND_RADIUS:
1827   case ECOND_LDAPAUTH:
1828   case ECOND_PWCHECK:
1829
1830   while (isspace(*s)) s++;
1831   if (*s != '{') goto COND_FAILED_CURLY_START;
1832
1833   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1834   if (sub[0] == NULL) return NULL;
1835   if (*s++ != '}') goto COND_FAILED_CURLY_END;
1836
1837   if (yield == NULL) return s;   /* No need to run the test if skipping */
1838
1839   switch(cond_type)
1840     {
1841     case ECOND_EXISTS:
1842     if ((expand_forbid & RDO_EXISTS) != 0)
1843       {
1844       expand_string_message = US"File existence tests are not permitted";
1845       return NULL;
1846       }
1847     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
1848     break;
1849
1850     case ECOND_ISIP:
1851     case ECOND_ISIP4:
1852     case ECOND_ISIP6:
1853     rc = string_is_ip_address(sub[0], NULL);
1854     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
1855              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
1856     break;
1857
1858     /* Various authentication tests - all optionally compiled */
1859
1860     case ECOND_PAM:
1861     #ifdef SUPPORT_PAM
1862     rc = auth_call_pam(sub[0], &expand_string_message);
1863     goto END_AUTH;
1864     #else
1865     goto COND_FAILED_NOT_COMPILED;
1866     #endif  /* SUPPORT_PAM */
1867
1868     case ECOND_RADIUS:
1869     #ifdef RADIUS_CONFIG_FILE
1870     rc = auth_call_radius(sub[0], &expand_string_message);
1871     goto END_AUTH;
1872     #else
1873     goto COND_FAILED_NOT_COMPILED;
1874     #endif  /* RADIUS_CONFIG_FILE */
1875
1876     case ECOND_LDAPAUTH:
1877     #ifdef LOOKUP_LDAP
1878       {
1879       /* Just to keep the interface the same */
1880       BOOL do_cache;
1881       int old_pool = store_pool;
1882       store_pool = POOL_SEARCH;
1883       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
1884         &expand_string_message, &do_cache);
1885       store_pool = old_pool;
1886       }
1887     goto END_AUTH;
1888     #else
1889     goto COND_FAILED_NOT_COMPILED;
1890     #endif  /* LOOKUP_LDAP */
1891
1892     case ECOND_PWCHECK:
1893     #ifdef CYRUS_PWCHECK_SOCKET
1894     rc = auth_call_pwcheck(sub[0], &expand_string_message);
1895     goto END_AUTH;
1896     #else
1897     goto COND_FAILED_NOT_COMPILED;
1898     #endif  /* CYRUS_PWCHECK_SOCKET */
1899
1900     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
1901         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
1902     END_AUTH:
1903     if (rc == ERROR || rc == DEFER) return NULL;
1904     *yield = (rc == OK) == testfor;
1905     #endif
1906     }
1907   return s;
1908
1909
1910   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
1911
1912      ${if saslauthd {{username}{password}{service}{realm}}  {yes}[no}}
1913
1914   However, the last two are optional. That is why the whole set is enclosed
1915   in their own set or braces. */
1916
1917   case ECOND_SASLAUTHD:
1918   #ifndef CYRUS_SASLAUTHD_SOCKET
1919   goto COND_FAILED_NOT_COMPILED;
1920   #else
1921   while (isspace(*s)) s++;
1922   if (*s++ != '{') goto COND_FAILED_CURLY_START;
1923   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
1924     {
1925     case 1: expand_string_message = US"too few arguments or bracketing "
1926       "error for saslauthd";
1927     case 2:
1928     case 3: return NULL;
1929     }
1930   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
1931   if (yield != NULL)
1932     {
1933     int rc;
1934     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
1935       &expand_string_message);
1936     if (rc == ERROR || rc == DEFER) return NULL;
1937     *yield = (rc == OK) == testfor;
1938     }
1939   return s;
1940   #endif /* CYRUS_SASLAUTHD_SOCKET */
1941
1942
1943   /* symbolic operators for numeric and string comparison, and a number of
1944   other operators, all requiring two arguments.
1945
1946   match:             does a regular expression match and sets up the numerical
1947                        variables if it succeeds
1948   match_address:     matches in an address list
1949   match_domain:      matches in a domain list
1950   match_ip:          matches a host list that is restricted to IP addresses
1951   match_local_part:  matches in a local part list
1952   crypteq:           encrypts plaintext and compares against an encrypted text,
1953                        using crypt(), crypt16(), MD5 or SHA-1
1954   */
1955
1956   case ECOND_MATCH:
1957   case ECOND_MATCH_ADDRESS:
1958   case ECOND_MATCH_DOMAIN:
1959   case ECOND_MATCH_IP:
1960   case ECOND_MATCH_LOCAL_PART:
1961   case ECOND_CRYPTEQ:
1962
1963   case ECOND_NUM_L:     /* Numerical comparisons */
1964   case ECOND_NUM_LE:
1965   case ECOND_NUM_E:
1966   case ECOND_NUM_EE:
1967   case ECOND_NUM_G:
1968   case ECOND_NUM_GE:
1969
1970   case ECOND_STR_LT:    /* String comparisons */
1971   case ECOND_STR_LTI:
1972   case ECOND_STR_LE:
1973   case ECOND_STR_LEI:
1974   case ECOND_STR_EQ:
1975   case ECOND_STR_EQI:
1976   case ECOND_STR_GT:
1977   case ECOND_STR_GTI:
1978   case ECOND_STR_GE:
1979   case ECOND_STR_GEI:
1980
1981   for (i = 0; i < 2; i++)
1982     {
1983     while (isspace(*s)) s++;
1984     if (*s != '{')
1985       {
1986       if (i == 0) goto COND_FAILED_CURLY_START;
1987       expand_string_message = string_sprintf("missing 2nd string in {} "
1988         "after \"%s\"", name);
1989       return NULL;
1990       }
1991     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1992     if (sub[i] == NULL) return NULL;
1993     if (*s++ != '}') goto COND_FAILED_CURLY_END;
1994
1995     /* Convert to numerical if required; we know that the names of all the
1996     conditions that compare numbers do not start with a letter. This just saves
1997     checking for them individually. */
1998
1999     if (!isalpha(name[0]) && yield != NULL)
2000       {
2001       if (sub[i][0] == 0)
2002         {
2003         num[i] = 0;
2004         DEBUG(D_expand)
2005           debug_printf("empty string cast to zero for numerical comparison\n");
2006         }
2007       else
2008         {
2009         num[i] = expand_string_integer(sub[i], FALSE);
2010         if (expand_string_message != NULL) return NULL;
2011         }
2012       }
2013     }
2014
2015   /* Result not required */
2016
2017   if (yield == NULL) return s;
2018
2019   /* Do an appropriate comparison */
2020
2021   switch(cond_type)
2022     {
2023     case ECOND_NUM_E:
2024     case ECOND_NUM_EE:
2025     *yield = (num[0] == num[1]) == testfor;
2026     break;
2027
2028     case ECOND_NUM_G:
2029     *yield = (num[0] > num[1]) == testfor;
2030     break;
2031
2032     case ECOND_NUM_GE:
2033     *yield = (num[0] >= num[1]) == testfor;
2034     break;
2035
2036     case ECOND_NUM_L:
2037     *yield = (num[0] < num[1]) == testfor;
2038     break;
2039
2040     case ECOND_NUM_LE:
2041     *yield = (num[0] <= num[1]) == testfor;
2042     break;
2043
2044     case ECOND_STR_LT:
2045     *yield = (Ustrcmp(sub[0], sub[1]) < 0) == testfor;
2046     break;
2047
2048     case ECOND_STR_LTI:
2049     *yield = (strcmpic(sub[0], sub[1]) < 0) == testfor;
2050     break;
2051
2052     case ECOND_STR_LE:
2053     *yield = (Ustrcmp(sub[0], sub[1]) <= 0) == testfor;
2054     break;
2055
2056     case ECOND_STR_LEI:
2057     *yield = (strcmpic(sub[0], sub[1]) <= 0) == testfor;
2058     break;
2059
2060     case ECOND_STR_EQ:
2061     *yield = (Ustrcmp(sub[0], sub[1]) == 0) == testfor;
2062     break;
2063
2064     case ECOND_STR_EQI:
2065     *yield = (strcmpic(sub[0], sub[1]) == 0) == testfor;
2066     break;
2067
2068     case ECOND_STR_GT:
2069     *yield = (Ustrcmp(sub[0], sub[1]) > 0) == testfor;
2070     break;
2071
2072     case ECOND_STR_GTI:
2073     *yield = (strcmpic(sub[0], sub[1]) > 0) == testfor;
2074     break;
2075
2076     case ECOND_STR_GE:
2077     *yield = (Ustrcmp(sub[0], sub[1]) >= 0) == testfor;
2078     break;
2079
2080     case ECOND_STR_GEI:
2081     *yield = (strcmpic(sub[0], sub[1]) >= 0) == testfor;
2082     break;
2083
2084     case ECOND_MATCH:   /* Regular expression match */
2085     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2086       NULL);
2087     if (re == NULL)
2088       {
2089       expand_string_message = string_sprintf("regular expression error in "
2090         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2091       return NULL;
2092       }
2093     *yield = regex_match_and_setup(re, sub[0], 0, -1) == testfor;
2094     break;
2095
2096     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2097     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2098     goto MATCHED_SOMETHING;
2099
2100     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2101     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2102       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2103     goto MATCHED_SOMETHING;
2104
2105     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2106     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2107       {
2108       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2109         sub[0]);
2110       return NULL;
2111       }
2112     else
2113       {
2114       unsigned int *nullcache = NULL;
2115       check_host_block cb;
2116
2117       cb.host_name = US"";
2118       cb.host_address = sub[0];
2119
2120       /* If the host address starts off ::ffff: it is an IPv6 address in
2121       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2122       addresses. */
2123
2124       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2125         cb.host_address + 7 : cb.host_address;
2126
2127       rc = match_check_list(
2128              &sub[1],                   /* the list */
2129              0,                         /* separator character */
2130              &hostlist_anchor,          /* anchor pointer */
2131              &nullcache,                /* cache pointer */
2132              check_host,                /* function for testing */
2133              &cb,                       /* argument for function */
2134              MCL_HOST,                  /* type of check */
2135              sub[0],                    /* text for debugging */
2136              NULL);                     /* where to pass back data */
2137       }
2138     goto MATCHED_SOMETHING;
2139
2140     case ECOND_MATCH_LOCAL_PART:
2141     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2142       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2143     /* Fall through */
2144     /* VVVVVVVVVVVV */
2145     MATCHED_SOMETHING:
2146     switch(rc)
2147       {
2148       case OK:
2149       *yield = testfor;
2150       break;
2151
2152       case FAIL:
2153       *yield = !testfor;
2154       break;
2155
2156       case DEFER:
2157       expand_string_message = string_sprintf("unable to complete match "
2158         "against \"%s\": %s", sub[1], search_error_message);
2159       return NULL;
2160       }
2161
2162     break;
2163
2164     /* Various "encrypted" comparisons. If the second string starts with
2165     "{" then an encryption type is given. Default to crypt() or crypt16()
2166     (build-time choice). */
2167
2168     case ECOND_CRYPTEQ:
2169     #ifndef SUPPORT_CRYPTEQ
2170     goto COND_FAILED_NOT_COMPILED;
2171     #else
2172     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2173       {
2174       int sublen = Ustrlen(sub[1]+5);
2175       md5 base;
2176       uschar digest[16];
2177
2178       md5_start(&base);
2179       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2180
2181       /* If the length that we are comparing against is 24, the MD5 digest
2182       is expressed as a base64 string. This is the way LDAP does it. However,
2183       some other software uses a straightforward hex representation. We assume
2184       this if the length is 32. Other lengths fail. */
2185
2186       if (sublen == 24)
2187         {
2188         uschar *coded = auth_b64encode((uschar *)digest, 16);
2189         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2190           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2191         *yield = (Ustrcmp(coded, sub[1]+5) == 0) == testfor;
2192         }
2193       else if (sublen == 32)
2194         {
2195         int i;
2196         uschar coded[36];
2197         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2198         coded[32] = 0;
2199         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2200           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2201         *yield = (strcmpic(coded, sub[1]+5) == 0) == testfor;
2202         }
2203       else
2204         {
2205         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2206           "fail\n  crypted=%s\n", sub[1]+5);
2207         *yield = !testfor;
2208         }
2209       }
2210
2211     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2212       {
2213       int sublen = Ustrlen(sub[1]+6);
2214       sha1 base;
2215       uschar digest[20];
2216
2217       sha1_start(&base);
2218       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2219
2220       /* If the length that we are comparing against is 28, assume the SHA1
2221       digest is expressed as a base64 string. If the length is 40, assume a
2222       straightforward hex representation. Other lengths fail. */
2223
2224       if (sublen == 28)
2225         {
2226         uschar *coded = auth_b64encode((uschar *)digest, 20);
2227         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2228           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2229         *yield = (Ustrcmp(coded, sub[1]+6) == 0) == testfor;
2230         }
2231       else if (sublen == 40)
2232         {
2233         int i;
2234         uschar coded[44];
2235         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2236         coded[40] = 0;
2237         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2238           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2239         *yield = (strcmpic(coded, sub[1]+6) == 0) == testfor;
2240         }
2241       else
2242         {
2243         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2244           "fail\n  crypted=%s\n", sub[1]+6);
2245         *yield = !testfor;
2246         }
2247       }
2248
2249     else   /* {crypt} or {crypt16} and non-{ at start */
2250       {
2251       int which = 0;
2252       uschar *coded;
2253
2254       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2255         {
2256         sub[1] += 7;
2257         which = 1;
2258         }
2259       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2260         {
2261         sub[1] += 9;
2262         which = 2;
2263         }
2264       else if (sub[1][0] == '{')
2265         {
2266         expand_string_message = string_sprintf("unknown encryption mechanism "
2267           "in \"%s\"", sub[1]);
2268         return NULL;
2269         }
2270
2271       switch(which)
2272         {
2273         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2274         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2275         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2276         }
2277
2278       #define STR(s) # s
2279       #define XSTR(s) STR(s)
2280       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2281         "  subject=%s\n  crypted=%s\n",
2282         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2283         coded, sub[1]);
2284       #undef STR
2285       #undef XSTR
2286
2287       /* If the encrypted string contains fewer than two characters (for the
2288       salt), force failure. Otherwise we get false positives: with an empty
2289       string the yield of crypt() is an empty string! */
2290
2291       *yield = (Ustrlen(sub[1]) < 2)? !testfor :
2292         (Ustrcmp(coded, sub[1]) == 0) == testfor;
2293       }
2294     break;
2295     #endif  /* SUPPORT_CRYPTEQ */
2296     }   /* Switch for comparison conditions */
2297
2298   return s;    /* End of comparison conditions */
2299
2300
2301   /* and/or: computes logical and/or of several conditions */
2302
2303   case ECOND_AND:
2304   case ECOND_OR:
2305   subcondptr = (yield == NULL)? NULL : &tempcond;
2306   combined_cond = (cond_type == ECOND_AND);
2307
2308   while (isspace(*s)) s++;
2309   if (*s++ != '{') goto COND_FAILED_CURLY_START;
2310
2311   for (;;)
2312     {
2313     while (isspace(*s)) s++;
2314     if (*s == '}') break;
2315     if (*s != '{')
2316       {
2317       expand_string_message = string_sprintf("each subcondition "
2318         "inside an \"%s{...}\" condition must be in its own {}", name);
2319       return NULL;
2320       }
2321
2322     s = eval_condition(s+1, subcondptr);
2323     if (s == NULL)
2324       {
2325       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2326         expand_string_message, name);
2327       return NULL;
2328       }
2329     while (isspace(*s)) s++;
2330
2331     if (*s++ != '}')
2332       {
2333       expand_string_message = string_sprintf("missing } at end of condition "
2334         "inside \"%s\" group", name);
2335       return NULL;
2336       }
2337
2338     if (yield != NULL)
2339       {
2340       if (cond_type == ECOND_AND)
2341         {
2342         combined_cond &= tempcond;
2343         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2344         }                                       /* evaluate any more */
2345       else
2346         {
2347         combined_cond |= tempcond;
2348         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2349         }                                       /* evaluate any more */
2350       }
2351     }
2352
2353   if (yield != NULL) *yield = (combined_cond == testfor);
2354   return ++s;
2355
2356
2357   /* forall/forany: iterates a condition with different values */
2358
2359   case ECOND_FORALL:
2360   case ECOND_FORANY:
2361     {
2362     int sep = 0;
2363     uschar *save_iterate_item = iterate_item;
2364
2365     while (isspace(*s)) s++;
2366     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2367
2368     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL));
2369     if (sub[0] == NULL) return NULL;
2370     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2371
2372     while (isspace(*s)) s++;
2373     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2374
2375     sub[1] = s;
2376
2377     /* Call eval_condition once, with result discarded (as if scanning a
2378     "false" part). This allows us to find the end of the condition, because if
2379     the list it empty, we won't actually evaluate the condition for real. */
2380
2381     s = eval_condition(sub[1], NULL);
2382     if (s == NULL)
2383       {
2384       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2385         expand_string_message, name);
2386       return NULL;
2387       }
2388     while (isspace(*s)) s++;
2389
2390     if (*s++ != '}')
2391       {
2392       expand_string_message = string_sprintf("missing } at end of condition "
2393         "inside \"%s\"", name);
2394       return NULL;
2395       }
2396
2397     if (yield != NULL) *yield = !testfor;
2398     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2399       {
2400       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2401       if (eval_condition(sub[1], &tempcond) == NULL)
2402         {
2403         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2404           expand_string_message, name);
2405         return NULL;
2406         }
2407       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2408         tempcond? "true":"false");
2409
2410       if (yield != NULL) *yield = (tempcond == testfor);
2411       if (tempcond == (cond_type == ECOND_FORANY)) break;
2412       }
2413
2414     iterate_item = save_iterate_item;
2415     return s;
2416     }
2417
2418
2419   /* Unknown condition */
2420
2421   default:
2422   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2423   return NULL;
2424   }   /* End switch on condition type */
2425
2426 /* Missing braces at start and end of data */
2427
2428 COND_FAILED_CURLY_START:
2429 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2430 return NULL;
2431
2432 COND_FAILED_CURLY_END:
2433 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2434   name);
2435 return NULL;
2436
2437 /* A condition requires code that is not compiled */
2438
2439 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2440     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2441     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2442 COND_FAILED_NOT_COMPILED:
2443 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2444   name);
2445 return NULL;
2446 #endif
2447 }
2448
2449
2450
2451
2452 /*************************************************
2453 *          Save numerical variables              *
2454 *************************************************/
2455
2456 /* This function is called from items such as "if" that want to preserve and
2457 restore the numbered variables.
2458
2459 Arguments:
2460   save_expand_string    points to an array of pointers to set
2461   save_expand_nlength   points to an array of ints for the lengths
2462
2463 Returns:                the value of expand max to save
2464 */
2465
2466 static int
2467 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2468 {
2469 int i;
2470 for (i = 0; i <= expand_nmax; i++)
2471   {
2472   save_expand_nstring[i] = expand_nstring[i];
2473   save_expand_nlength[i] = expand_nlength[i];
2474   }
2475 return expand_nmax;
2476 }
2477
2478
2479
2480 /*************************************************
2481 *           Restore numerical variables          *
2482 *************************************************/
2483
2484 /* This function restored saved values of numerical strings.
2485
2486 Arguments:
2487   save_expand_nmax      the number of strings to restore
2488   save_expand_string    points to an array of pointers
2489   save_expand_nlength   points to an array of ints
2490
2491 Returns:                nothing
2492 */
2493
2494 static void
2495 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2496   int *save_expand_nlength)
2497 {
2498 int i;
2499 expand_nmax = save_expand_nmax;
2500 for (i = 0; i <= expand_nmax; i++)
2501   {
2502   expand_nstring[i] = save_expand_nstring[i];
2503   expand_nlength[i] = save_expand_nlength[i];
2504   }
2505 }
2506
2507
2508
2509
2510
2511 /*************************************************
2512 *            Handle yes/no substrings            *
2513 *************************************************/
2514
2515 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2516 alternative substrings that depend on whether or not the condition was true,
2517 or the lookup or extraction succeeded. The substrings always have to be
2518 expanded, to check their syntax, but "skipping" is set when the result is not
2519 needed - this avoids unnecessary nested lookups.
2520
2521 Arguments:
2522   skipping       TRUE if we were skipping when this item was reached
2523   yes            TRUE if the first string is to be used, else use the second
2524   save_lookup    a value to put back into lookup_value before the 2nd expansion
2525   sptr           points to the input string pointer
2526   yieldptr       points to the output string pointer
2527   sizeptr        points to the output string size
2528   ptrptr         points to the output string pointer
2529   type           "lookup" or "if" or "extract" or "run", for error message
2530
2531 Returns:         0 OK; lookup_value has been reset to save_lookup
2532                  1 expansion failed
2533                  2 expansion failed because of bracketing error
2534 */
2535
2536 static int
2537 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2538   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2539 {
2540 int rc = 0;
2541 uschar *s = *sptr;    /* Local value */
2542 uschar *sub1, *sub2;
2543
2544 /* If there are no following strings, we substitute the contents of $value for
2545 lookups and for extractions in the success case. For the ${if item, the string
2546 "true" is substituted. In the fail case, nothing is substituted for all three
2547 items. */
2548
2549 while (isspace(*s)) s++;
2550 if (*s == '}')
2551   {
2552   if (type[0] == 'i')
2553     {
2554     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2555     }
2556   else
2557     {
2558     if (yes && lookup_value != NULL)
2559       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2560         Ustrlen(lookup_value));
2561     lookup_value = save_lookup;
2562     }
2563   s++;
2564   goto RETURN;
2565   }
2566
2567 /* The first following string must be braced. */
2568
2569 if (*s++ != '{') goto FAILED_CURLY;
2570
2571 /* Expand the first substring. Forced failures are noticed only if we actually
2572 want this string. Set skipping in the call in the fail case (this will always
2573 be the case if we were already skipping). */
2574
2575 sub1 = expand_string_internal(s, TRUE, &s, !yes);
2576 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2577 expand_string_forcedfail = FALSE;
2578 if (*s++ != '}') goto FAILED_CURLY;
2579
2580 /* If we want the first string, add it to the output */
2581
2582 if (yes)
2583   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2584
2585 /* If this is called from a lookup or an extract, we want to restore $value to
2586 what it was at the start of the item, so that it has this value during the
2587 second string expansion. For the call from "if" or "run" to this function,
2588 save_lookup is set to lookup_value, so that this statement does nothing. */
2589
2590 lookup_value = save_lookup;
2591
2592 /* There now follows either another substring, or "fail", or nothing. This
2593 time, forced failures are noticed only if we want the second string. We must
2594 set skipping in the nested call if we don't want this string, or if we were
2595 already skipping. */
2596
2597 while (isspace(*s)) s++;
2598 if (*s == '{')
2599   {
2600   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping);
2601   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2602   expand_string_forcedfail = FALSE;
2603   if (*s++ != '}') goto FAILED_CURLY;
2604
2605   /* If we want the second string, add it to the output */
2606
2607   if (!yes)
2608     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2609   }
2610
2611 /* If there is no second string, but the word "fail" is present when the use of
2612 the second string is wanted, set a flag indicating it was a forced failure
2613 rather than a syntactic error. Swallow the terminating } in case this is nested
2614 inside another lookup or if or extract. */
2615
2616 else if (*s != '}')
2617   {
2618   uschar name[256];
2619   s = read_name(name, sizeof(name), s, US"_");
2620   if (Ustrcmp(name, "fail") == 0)
2621     {
2622     if (!yes && !skipping)
2623       {
2624       while (isspace(*s)) s++;
2625       if (*s++ != '}') goto FAILED_CURLY;
2626       expand_string_message =
2627         string_sprintf("\"%s\" failed and \"fail\" requested", type);
2628       expand_string_forcedfail = TRUE;
2629       goto FAILED;
2630       }
2631     }
2632   else
2633     {
2634     expand_string_message =
2635       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
2636     goto FAILED;
2637     }
2638   }
2639
2640 /* All we have to do now is to check on the final closing brace. */
2641
2642 while (isspace(*s)) s++;
2643 if (*s++ == '}') goto RETURN;
2644
2645 /* Get here if there is a bracketing failure */
2646
2647 FAILED_CURLY:
2648 rc++;
2649
2650 /* Get here for other failures */
2651
2652 FAILED:
2653 rc++;
2654
2655 /* Update the input pointer value before returning */
2656
2657 RETURN:
2658 *sptr = s;
2659 return rc;
2660 }
2661
2662
2663
2664
2665 /*************************************************
2666 *    Handle MD5 or SHA-1 computation for HMAC    *
2667 *************************************************/
2668
2669 /* These are some wrapping functions that enable the HMAC code to be a bit
2670 cleaner. A good compiler will spot the tail recursion.
2671
2672 Arguments:
2673   type         HMAC_MD5 or HMAC_SHA1
2674   remaining    are as for the cryptographic hash functions
2675
2676 Returns:       nothing
2677 */
2678
2679 static void
2680 chash_start(int type, void *base)
2681 {
2682 if (type == HMAC_MD5)
2683   md5_start((md5 *)base);
2684 else
2685   sha1_start((sha1 *)base);
2686 }
2687
2688 static void
2689 chash_mid(int type, void *base, uschar *string)
2690 {
2691 if (type == HMAC_MD5)
2692   md5_mid((md5 *)base, string);
2693 else
2694   sha1_mid((sha1 *)base, string);
2695 }
2696
2697 static void
2698 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
2699 {
2700 if (type == HMAC_MD5)
2701   md5_end((md5 *)base, string, length, digest);
2702 else
2703   sha1_end((sha1 *)base, string, length, digest);
2704 }
2705
2706
2707
2708
2709
2710 /********************************************************
2711 * prvs: Get last three digits of days since Jan 1, 1970 *
2712 ********************************************************/
2713
2714 /* This is needed to implement the "prvs" BATV reverse
2715    path signing scheme
2716
2717 Argument: integer "days" offset to add or substract to
2718           or from the current number of days.
2719
2720 Returns:  pointer to string containing the last three
2721           digits of the number of days since Jan 1, 1970,
2722           modified by the offset argument, NULL if there
2723           was an error in the conversion.
2724
2725 */
2726
2727 static uschar *
2728 prvs_daystamp(int day_offset)
2729 {
2730 uschar *days = store_get(32);                /* Need at least 24 for cases */
2731 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
2732   (time(NULL) + day_offset*86400)/86400);
2733 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
2734 }
2735
2736
2737
2738 /********************************************************
2739 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
2740 ********************************************************/
2741
2742 /* This is needed to implement the "prvs" BATV reverse
2743    path signing scheme
2744
2745 Arguments:
2746   address RFC2821 Address to use
2747       key The key to use (must be less than 64 characters
2748           in size)
2749   key_num Single-digit key number to use. Defaults to
2750           '0' when NULL.
2751
2752 Returns:  pointer to string containing the first three
2753           bytes of the final hash in hex format, NULL if
2754           there was an error in the process.
2755 */
2756
2757 static uschar *
2758 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
2759 {
2760 uschar *hash_source, *p;
2761 int size = 0,offset = 0,i;
2762 sha1 sha1_base;
2763 void *use_base = &sha1_base;
2764 uschar innerhash[20];
2765 uschar finalhash[20];
2766 uschar innerkey[64];
2767 uschar outerkey[64];
2768 uschar *finalhash_hex = store_get(40);
2769
2770 if (key_num == NULL)
2771   key_num = US"0";
2772
2773 if (Ustrlen(key) > 64)
2774   return NULL;
2775
2776 hash_source = string_cat(NULL,&size,&offset,key_num,1);
2777 string_cat(hash_source,&size,&offset,daystamp,3);
2778 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
2779 hash_source[offset] = '\0';
2780
2781 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
2782
2783 memset(innerkey, 0x36, 64);
2784 memset(outerkey, 0x5c, 64);
2785
2786 for (i = 0; i < Ustrlen(key); i++)
2787   {
2788   innerkey[i] ^= key[i];
2789   outerkey[i] ^= key[i];
2790   }
2791
2792 chash_start(HMAC_SHA1, use_base);
2793 chash_mid(HMAC_SHA1, use_base, innerkey);
2794 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
2795
2796 chash_start(HMAC_SHA1, use_base);
2797 chash_mid(HMAC_SHA1, use_base, outerkey);
2798 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
2799
2800 p = finalhash_hex;
2801 for (i = 0; i < 3; i++)
2802   {
2803   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
2804   *p++ = hex_digits[finalhash[i] & 0x0f];
2805   }
2806 *p = '\0';
2807
2808 return finalhash_hex;
2809 }
2810
2811
2812
2813
2814 /*************************************************
2815 *        Join a file onto the output string      *
2816 *************************************************/
2817
2818 /* This is used for readfile and after a run expansion. It joins the contents
2819 of a file onto the output string, globally replacing newlines with a given
2820 string (optionally). The file is closed at the end.
2821
2822 Arguments:
2823   f            the FILE
2824   yield        pointer to the expandable string
2825   sizep        pointer to the current size
2826   ptrp         pointer to the current position
2827   eol          newline replacement string, or NULL
2828
2829 Returns:       new value of string pointer
2830 */
2831
2832 static uschar *
2833 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
2834 {
2835 int eollen;
2836 uschar buffer[1024];
2837
2838 eollen = (eol == NULL)? 0 : Ustrlen(eol);
2839
2840 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
2841   {
2842   int len = Ustrlen(buffer);
2843   if (eol != NULL && buffer[len-1] == '\n') len--;
2844   yield = string_cat(yield, sizep, ptrp, buffer, len);
2845   if (buffer[len] != 0)
2846     yield = string_cat(yield, sizep, ptrp, eol, eollen);
2847   }
2848
2849 if (yield != NULL) yield[*ptrp] = 0;
2850
2851 return yield;
2852 }
2853
2854
2855
2856
2857 /*************************************************
2858 *          Evaluate numeric expression           *
2859 *************************************************/
2860
2861 /* This is a set of mutually recursive functions that evaluate an arithmetic
2862 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
2863 these functions that is called from elsewhere is eval_expr, whose interface is:
2864
2865 Arguments:
2866   sptr        pointer to the pointer to the string - gets updated
2867   decimal     TRUE if numbers are to be assumed decimal
2868   error       pointer to where to put an error message - must be NULL on input
2869   endket      TRUE if ')' must terminate - FALSE for external call
2870
2871 Returns:      on success: the value of the expression, with *error still NULL
2872               on failure: an undefined value, with *error = a message
2873 */
2874
2875 static int eval_op_or(uschar **, BOOL, uschar **);
2876
2877
2878 static int
2879 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
2880 {
2881 uschar *s = *sptr;
2882 int x = eval_op_or(&s, decimal, error);
2883 if (*error == NULL)
2884   {
2885   if (endket)
2886     {
2887     if (*s != ')')
2888       *error = US"expecting closing parenthesis";
2889     else
2890       while (isspace(*(++s)));
2891     }
2892   else if (*s != 0) *error = US"expecting operator";
2893   }
2894 *sptr = s;
2895 return x;
2896 }
2897
2898
2899 static int
2900 eval_number(uschar **sptr, BOOL decimal, uschar **error)
2901 {
2902 register int c;
2903 int n;
2904 uschar *s = *sptr;
2905 while (isspace(*s)) s++;
2906 c = *s;
2907 if (isdigit(c))
2908   {
2909   int count;
2910   (void)sscanf(CS s, (decimal? "%d%n" : "%i%n"), &n, &count);
2911   s += count;
2912   if (tolower(*s) == 'k') { n *= 1024; s++; }
2913     else if (tolower(*s) == 'm') { n *= 1024*1024; s++; }
2914   while (isspace (*s)) s++;
2915   }
2916 else if (c == '(')
2917   {
2918   s++;
2919   n = eval_expr(&s, decimal, error, 1);
2920   }
2921 else
2922   {
2923   *error = US"expecting number or opening parenthesis";
2924   n = 0;
2925   }
2926 *sptr = s;
2927 return n;
2928 }
2929
2930
2931 static int eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
2932 {
2933 uschar *s = *sptr;
2934 int x;
2935 while (isspace(*s)) s++;
2936 if (*s == '+' || *s == '-' || *s == '~')
2937   {
2938   int op = *s++;
2939   x = eval_op_unary(&s, decimal, error);
2940   if (op == '-') x = -x;
2941     else if (op == '~') x = ~x;
2942   }
2943 else
2944   {
2945   x = eval_number(&s, decimal, error);
2946   }
2947 *sptr = s;
2948 return x;
2949 }
2950
2951
2952 static int eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
2953 {
2954 uschar *s = *sptr;
2955 int x = eval_op_unary(&s, decimal, error);
2956 if (*error == NULL)
2957   {
2958   while (*s == '*' || *s == '/' || *s == '%')
2959     {
2960     int op = *s++;
2961     int y = eval_op_unary(&s, decimal, error);
2962     if (*error != NULL) break;
2963     if (op == '*') x *= y;
2964       else if (op == '/') x /= y;
2965       else x %= y;
2966     }
2967   }
2968 *sptr = s;
2969 return x;
2970 }
2971
2972
2973 static int eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
2974 {
2975 uschar *s = *sptr;
2976 int x = eval_op_mult(&s, decimal, error);
2977 if (*error == NULL)
2978   {
2979   while (*s == '+' || *s == '-')
2980     {
2981     int op = *s++;
2982     int y = eval_op_mult(&s, decimal, error);
2983     if (*error != NULL) break;
2984     if (op == '+') x += y; else x -= y;
2985     }
2986   }
2987 *sptr = s;
2988 return x;
2989 }
2990
2991
2992 static int eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
2993 {
2994 uschar *s = *sptr;
2995 int x = eval_op_sum(&s, decimal, error);
2996 if (*error == NULL)
2997   {
2998   while ((*s == '<' || *s == '>') && s[1] == s[0])
2999     {
3000     int y;
3001     int op = *s++;
3002     s++;
3003     y = eval_op_sum(&s, decimal, error);
3004     if (*error != NULL) break;
3005     if (op == '<') x <<= y; else x >>= y;
3006     }
3007   }
3008 *sptr = s;
3009 return x;
3010 }
3011
3012
3013 static int eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3014 {
3015 uschar *s = *sptr;
3016 int x = eval_op_shift(&s, decimal, error);
3017 if (*error == NULL)
3018   {
3019   while (*s == '&')
3020     {
3021     int y;
3022     s++;
3023     y = eval_op_shift(&s, decimal, error);
3024     if (*error != NULL) break;
3025     x &= y;
3026     }
3027   }
3028 *sptr = s;
3029 return x;
3030 }
3031
3032
3033 static int eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3034 {
3035 uschar *s = *sptr;
3036 int x = eval_op_and(&s, decimal, error);
3037 if (*error == NULL)
3038   {
3039   while (*s == '^')
3040     {
3041     int y;
3042     s++;
3043     y = eval_op_and(&s, decimal, error);
3044     if (*error != NULL) break;
3045     x ^= y;
3046     }
3047   }
3048 *sptr = s;
3049 return x;
3050 }
3051
3052
3053 static int eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3054 {
3055 uschar *s = *sptr;
3056 int x = eval_op_xor(&s, decimal, error);
3057 if (*error == NULL)
3058   {
3059   while (*s == '|')
3060     {
3061     int y;
3062     s++;
3063     y = eval_op_xor(&s, decimal, error);
3064     if (*error != NULL) break;
3065     x |= y;
3066     }
3067   }
3068 *sptr = s;
3069 return x;
3070 }
3071
3072
3073
3074 /*************************************************
3075 *                 Expand string                  *
3076 *************************************************/
3077
3078 /* Returns either an unchanged string, or the expanded string in stacking pool
3079 store. Interpreted sequences are:
3080
3081    \...                    normal escaping rules
3082    $name                   substitutes the variable
3083    ${name}                 ditto
3084    ${op:string}            operates on the expanded string value
3085    ${item{arg1}{arg2}...}  expands the args and then does the business
3086                              some literal args are not enclosed in {}
3087
3088 There are now far too many operators and item types to make it worth listing
3089 them here in detail any more.
3090
3091 We use an internal routine recursively to handle embedded substrings. The
3092 external function follows. The yield is NULL if the expansion failed, and there
3093 are two cases: if something collapsed syntactically, or if "fail" was given
3094 as the action on a lookup failure. These can be distinguised by looking at the
3095 variable expand_string_forcedfail, which is TRUE in the latter case.
3096
3097 The skipping flag is set true when expanding a substring that isn't actually
3098 going to be used (after "if" or "lookup") and it prevents lookups from
3099 happening lower down.
3100
3101 Store usage: At start, a store block of the length of the input plus 64
3102 is obtained. This is expanded as necessary by string_cat(), which might have to
3103 get a new block, or might be able to expand the original. At the end of the
3104 function we can release any store above that portion of the yield block that
3105 was actually used. In many cases this will be optimal.
3106
3107 However: if the first item in the expansion is a variable name or header name,
3108 we reset the store before processing it; if the result is in fresh store, we
3109 use that without copying. This is helpful for expanding strings like
3110 $message_headers which can get very long.
3111
3112 Arguments:
3113   string         the string to be expanded
3114   ket_ends       true if expansion is to stop at }
3115   left           if not NULL, a pointer to the first character after the
3116                  expansion is placed here (typically used with ket_ends)
3117   skipping       TRUE for recursive calls when the value isn't actually going
3118                  to be used (to allow for optimisation)
3119
3120 Returns:         NULL if expansion fails:
3121                    expand_string_forcedfail is set TRUE if failure was forced
3122                    expand_string_message contains a textual error message
3123                  a pointer to the expanded string on success
3124 */
3125
3126 static uschar *
3127 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3128   BOOL skipping)
3129 {
3130 int ptr = 0;
3131 int size = Ustrlen(string)+ 64;
3132 int item_type;
3133 uschar *yield = store_get(size);
3134 uschar *s = string;
3135 uschar *save_expand_nstring[EXPAND_MAXN+1];
3136 int save_expand_nlength[EXPAND_MAXN+1];
3137
3138 expand_string_forcedfail = FALSE;
3139 expand_string_message = US"";
3140
3141 while (*s != 0)
3142   {
3143   uschar *value;
3144   uschar name[256];
3145
3146   /* \ escapes the next character, which must exist, or else
3147   the expansion fails. There's a special escape, \N, which causes
3148   copying of the subject verbatim up to the next \N. Otherwise,
3149   the escapes are the standard set. */
3150
3151   if (*s == '\\')
3152     {
3153     if (s[1] == 0)
3154       {
3155       expand_string_message = US"\\ at end of string";
3156       goto EXPAND_FAILED;
3157       }
3158
3159     if (s[1] == 'N')
3160       {
3161       uschar *t = s + 2;
3162       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3163       yield = string_cat(yield, &size, &ptr, t, s - t);
3164       if (*s != 0) s += 2;
3165       }
3166
3167     else
3168       {
3169       uschar ch[1];
3170       ch[0] = string_interpret_escape(&s);
3171       s++;
3172       yield = string_cat(yield, &size, &ptr, ch, 1);
3173       }
3174
3175     continue;
3176     }
3177
3178   /* Anything other than $ is just copied verbatim, unless we are
3179   looking for a terminating } character. */
3180
3181   if (ket_ends && *s == '}') break;
3182
3183   if (*s != '$')
3184     {
3185     yield = string_cat(yield, &size, &ptr, s++, 1);
3186     continue;
3187     }
3188
3189   /* No { after the $ - must be a plain name or a number for string
3190   match variable. There has to be a fudge for variables that are the
3191   names of header fields preceded by "$header_" because header field
3192   names can contain any printing characters except space and colon.
3193   For those that don't like typing this much, "$h_" is a synonym for
3194   "$header_". A non-existent header yields a NULL value; nothing is
3195   inserted. */
3196
3197   if (isalpha((*(++s))))
3198     {
3199     int len;
3200     int newsize = 0;
3201
3202     s = read_name(name, sizeof(name), s, US"_");
3203
3204     /* If this is the first thing to be expanded, release the pre-allocated
3205     buffer. */
3206
3207     if (ptr == 0 && yield != NULL)
3208       {
3209       store_reset(yield);
3210       yield = NULL;
3211       size = 0;
3212       }
3213
3214     /* Header */
3215
3216     if (Ustrncmp(name, "h_", 2) == 0 ||
3217         Ustrncmp(name, "rh_", 3) == 0 ||
3218         Ustrncmp(name, "bh_", 3) == 0 ||
3219         Ustrncmp(name, "header_", 7) == 0 ||
3220         Ustrncmp(name, "rheader_", 8) == 0 ||
3221         Ustrncmp(name, "bheader_", 8) == 0)
3222       {
3223       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3224       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3225       s = read_header_name(name, sizeof(name), s);
3226       value = find_header(name, FALSE, &newsize, want_raw, charset);
3227
3228       /* If we didn't find the header, and the header contains a closing brace
3229       character, this may be a user error where the terminating colon
3230       has been omitted. Set a flag to adjust the error message in this case.
3231       But there is no error here - nothing gets inserted. */
3232
3233       if (value == NULL)
3234         {
3235         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3236         continue;
3237         }
3238       }
3239
3240     /* Variable */
3241
3242     else
3243       {
3244       value = find_variable(name, FALSE, skipping, &newsize);
3245       if (value == NULL)
3246         {
3247         expand_string_message =
3248           string_sprintf("unknown variable name \"%s\"", name);
3249           check_variable_error_message(name);
3250         goto EXPAND_FAILED;
3251         }
3252       }
3253
3254     /* If the data is known to be in a new buffer, newsize will be set to the
3255     size of that buffer. If this is the first thing in an expansion string,
3256     yield will be NULL; just point it at the new store instead of copying. Many
3257     expansion strings contain just one reference, so this is a useful
3258     optimization, especially for humungous headers. */
3259
3260     len = Ustrlen(value);
3261     if (yield == NULL && newsize != 0)
3262       {
3263       yield = value;
3264       size = newsize;
3265       ptr = len;
3266       }
3267     else yield = string_cat(yield, &size, &ptr, value, len);
3268
3269     continue;
3270     }
3271
3272   if (isdigit(*s))
3273     {
3274     int n;
3275     s = read_number(&n, s);
3276     if (n >= 0 && n <= expand_nmax)
3277       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3278         expand_nlength[n]);
3279     continue;
3280     }
3281
3282   /* Otherwise, if there's no '{' after $ it's an error. */
3283
3284   if (*s != '{')
3285     {
3286     expand_string_message = US"$ not followed by letter, digit, or {";
3287     goto EXPAND_FAILED;
3288     }
3289
3290   /* After { there can be various things, but they all start with
3291   an initial word, except for a number for a string match variable. */
3292
3293   if (isdigit((*(++s))))
3294     {
3295     int n;
3296     s = read_number(&n, s);
3297     if (*s++ != '}')
3298       {
3299       expand_string_message = US"} expected after number";
3300       goto EXPAND_FAILED;
3301       }
3302     if (n >= 0 && n <= expand_nmax)
3303       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3304         expand_nlength[n]);
3305     continue;
3306     }
3307
3308   if (!isalpha(*s))
3309     {
3310     expand_string_message = US"letter or digit expected after ${";
3311     goto EXPAND_FAILED;
3312     }
3313
3314   /* Allow "-" in names to cater for substrings with negative
3315   arguments. Since we are checking for known names after { this is
3316   OK. */
3317
3318   s = read_name(name, sizeof(name), s, US"_-");
3319   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3320
3321   switch(item_type)
3322     {
3323     /* Handle conditionals - preserve the values of the numerical expansion
3324     variables in case they get changed by a regular expression match in the
3325     condition. If not, they retain their external settings. At the end
3326     of this "if" section, they get restored to their previous values. */
3327
3328     case EITEM_IF:
3329       {
3330       BOOL cond = FALSE;
3331       uschar *next_s;
3332       int save_expand_nmax =
3333         save_expand_strings(save_expand_nstring, save_expand_nlength);
3334
3335       while (isspace(*s)) s++;
3336       next_s = eval_condition(s, skipping? NULL : &cond);
3337       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3338
3339       DEBUG(D_expand)
3340         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3341           cond? "true" : "false");
3342
3343       s = next_s;
3344
3345       /* The handling of "yes" and "no" result strings is now in a separate
3346       function that is also used by ${lookup} and ${extract} and ${run}. */
3347
3348       switch(process_yesno(
3349                skipping,                     /* were previously skipping */
3350                cond,                         /* success/failure indicator */
3351                lookup_value,                 /* value to reset for string2 */
3352                &s,                           /* input pointer */
3353                &yield,                       /* output pointer */
3354                &size,                        /* output size */
3355                &ptr,                         /* output current point */
3356                US"if"))                      /* condition type */
3357         {
3358         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3359         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3360         }
3361
3362       /* Restore external setting of expansion variables for continuation
3363       at this level. */
3364
3365       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3366         save_expand_nlength);
3367       continue;
3368       }
3369
3370     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
3371     expanding an internal string that isn't actually going to be used. All we
3372     need to do is check the syntax, so don't do a lookup at all. Preserve the
3373     values of the numerical expansion variables in case they get changed by a
3374     partial lookup. If not, they retain their external settings. At the end
3375     of this "lookup" section, they get restored to their previous values. */
3376
3377     case EITEM_LOOKUP:
3378       {
3379       int stype, partial, affixlen, starflags;
3380       int expand_setup = 0;
3381       int nameptr = 0;
3382       uschar *key, *filename, *affix;
3383       uschar *save_lookup_value = lookup_value;
3384       int save_expand_nmax =
3385         save_expand_strings(save_expand_nstring, save_expand_nlength);
3386
3387       if ((expand_forbid & RDO_LOOKUP) != 0)
3388         {
3389         expand_string_message = US"lookup expansions are not permitted";
3390         goto EXPAND_FAILED;
3391         }
3392
3393       /* Get the key we are to look up for single-key+file style lookups.
3394       Otherwise set the key NULL pro-tem. */
3395
3396       while (isspace(*s)) s++;
3397       if (*s == '{')
3398         {
3399         key = expand_string_internal(s+1, TRUE, &s, skipping);
3400         if (key == NULL) goto EXPAND_FAILED;
3401         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3402         while (isspace(*s)) s++;
3403         }
3404       else key = NULL;
3405
3406       /* Find out the type of database */
3407
3408       if (!isalpha(*s))
3409         {
3410         expand_string_message = US"missing lookup type";
3411         goto EXPAND_FAILED;
3412         }
3413
3414       /* The type is a string that may contain special characters of various
3415       kinds. Allow everything except space or { to appear; the actual content
3416       is checked by search_findtype_partial. */
3417
3418       while (*s != 0 && *s != '{' && !isspace(*s))
3419         {
3420         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
3421         s++;
3422         }
3423       name[nameptr] = 0;
3424       while (isspace(*s)) s++;
3425
3426       /* Now check for the individual search type and any partial or default
3427       options. Only those types that are actually in the binary are valid. */
3428
3429       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
3430         &starflags);
3431       if (stype < 0)
3432         {
3433         expand_string_message = search_error_message;
3434         goto EXPAND_FAILED;
3435         }
3436
3437       /* Check that a key was provided for those lookup types that need it,
3438       and was not supplied for those that use the query style. */
3439
3440       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
3441         {
3442         if (key == NULL)
3443           {
3444           expand_string_message = string_sprintf("missing {key} for single-"
3445             "key \"%s\" lookup", name);
3446           goto EXPAND_FAILED;
3447           }
3448         }
3449       else
3450         {
3451         if (key != NULL)
3452           {
3453           expand_string_message = string_sprintf("a single key was given for "
3454             "lookup type \"%s\", which is not a single-key lookup type", name);
3455           goto EXPAND_FAILED;
3456           }
3457         }
3458
3459       /* Get the next string in brackets and expand it. It is the file name for
3460       single-key+file lookups, and the whole query otherwise. In the case of
3461       queries that also require a file name (e.g. sqlite), the file name comes
3462       first. */
3463
3464       if (*s != '{') goto EXPAND_FAILED_CURLY;
3465       filename = expand_string_internal(s+1, TRUE, &s, skipping);
3466       if (filename == NULL) goto EXPAND_FAILED;
3467       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3468       while (isspace(*s)) s++;
3469
3470       /* If this isn't a single-key+file lookup, re-arrange the variables
3471       to be appropriate for the search_ functions. For query-style lookups,
3472       there is just a "key", and no file name. For the special query-style +
3473       file types, the query (i.e. "key") starts with a file name. */
3474
3475       if (key == NULL)
3476         {
3477         while (isspace(*filename)) filename++;
3478         key = filename;
3479
3480         if (mac_islookup(stype, lookup_querystyle))
3481           {
3482           filename = NULL;
3483           }
3484         else
3485           {
3486           if (*filename != '/')
3487             {
3488             expand_string_message = string_sprintf(
3489               "absolute file name expected for \"%s\" lookup", name);
3490             goto EXPAND_FAILED;
3491             }
3492           while (*key != 0 && !isspace(*key)) key++;
3493           if (*key != 0) *key++ = 0;
3494           }
3495         }
3496
3497       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
3498       the entry was not found. Note that there is no search_close() function.
3499       Files are left open in case of re-use. At suitable places in higher logic,
3500       search_tidyup() is called to tidy all open files. This can save opening
3501       the same file several times. However, files may also get closed when
3502       others are opened, if too many are open at once. The rule is that a
3503       handle should not be used after a second search_open().
3504
3505       Request that a partial search sets up $1 and maybe $2 by passing
3506       expand_setup containing zero. If its value changes, reset expand_nmax,
3507       since new variables will have been set. Note that at the end of this
3508       "lookup" section, the old numeric variables are restored. */
3509
3510       if (skipping)
3511         lookup_value = NULL;
3512       else
3513         {
3514         void *handle = search_open(filename, stype, 0, NULL, NULL);
3515         if (handle == NULL)
3516           {
3517           expand_string_message = search_error_message;
3518           goto EXPAND_FAILED;
3519           }
3520         lookup_value = search_find(handle, filename, key, partial, affix,
3521           affixlen, starflags, &expand_setup);
3522         if (search_find_defer)
3523           {
3524           expand_string_message =
3525             string_sprintf("lookup of \"%s\" gave DEFER: %s", key,
3526               search_error_message);
3527           goto EXPAND_FAILED;
3528           }
3529         if (expand_setup > 0) expand_nmax = expand_setup;
3530         }
3531
3532       /* The handling of "yes" and "no" result strings is now in a separate
3533       function that is also used by ${if} and ${extract}. */
3534
3535       switch(process_yesno(
3536                skipping,                     /* were previously skipping */
3537                lookup_value != NULL,         /* success/failure indicator */
3538                save_lookup_value,            /* value to reset for string2 */
3539                &s,                           /* input pointer */
3540                &yield,                       /* output pointer */
3541                &size,                        /* output size */
3542                &ptr,                         /* output current point */
3543                US"lookup"))                  /* condition type */
3544         {
3545         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3546         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3547         }
3548
3549       /* Restore external setting of expansion variables for carrying on
3550       at this level, and continue. */
3551
3552       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3553         save_expand_nlength);
3554       continue;
3555       }
3556
3557     /* If Perl support is configured, handle calling embedded perl subroutines,
3558     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
3559     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
3560     arguments (defined below). */
3561
3562     #define EXIM_PERL_MAX_ARGS 8
3563
3564     case EITEM_PERL:
3565     #ifndef EXIM_PERL
3566     expand_string_message = US"\"${perl\" encountered, but this facility "
3567       "is not included in this binary";
3568     goto EXPAND_FAILED;
3569
3570     #else   /* EXIM_PERL */
3571       {
3572       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
3573       uschar *new_yield;
3574
3575       if ((expand_forbid & RDO_PERL) != 0)
3576         {
3577         expand_string_message = US"Perl calls are not permitted";
3578         goto EXPAND_FAILED;
3579         }
3580
3581       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
3582            US"perl"))
3583         {
3584         case 1: goto EXPAND_FAILED_CURLY;
3585         case 2:
3586         case 3: goto EXPAND_FAILED;
3587         }
3588
3589       /* If skipping, we don't actually do anything */
3590
3591       if (skipping) continue;
3592
3593       /* Start the interpreter if necessary */
3594
3595       if (!opt_perl_started)
3596         {
3597         uschar *initerror;
3598         if (opt_perl_startup == NULL)
3599           {
3600           expand_string_message = US"A setting of perl_startup is needed when "
3601             "using the Perl interpreter";
3602           goto EXPAND_FAILED;
3603           }
3604         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
3605         initerror = init_perl(opt_perl_startup);
3606         if (initerror != NULL)
3607           {
3608           expand_string_message =
3609             string_sprintf("error in perl_startup code: %s\n", initerror);
3610           goto EXPAND_FAILED;
3611           }
3612         opt_perl_started = TRUE;
3613         }
3614
3615       /* Call the function */
3616
3617       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
3618       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
3619         sub_arg[0], sub_arg + 1);
3620
3621       /* NULL yield indicates failure; if the message pointer has been set to
3622       NULL, the yield was undef, indicating a forced failure. Otherwise the
3623       message will indicate some kind of Perl error. */
3624
3625       if (new_yield == NULL)
3626         {
3627         if (expand_string_message == NULL)
3628           {
3629           expand_string_message =
3630             string_sprintf("Perl subroutine \"%s\" returned undef to force "
3631               "failure", sub_arg[0]);
3632           expand_string_forcedfail = TRUE;
3633           }
3634         goto EXPAND_FAILED;
3635         }
3636
3637       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
3638       set during a callback from Perl. */
3639
3640       expand_string_forcedfail = FALSE;
3641       yield = new_yield;
3642       continue;
3643       }
3644     #endif /* EXIM_PERL */
3645
3646     /* Transform email address to "prvs" scheme to use
3647        as BATV-signed return path */
3648
3649     case EITEM_PRVS:
3650       {
3651       uschar *sub_arg[3];
3652       uschar *p,*domain;
3653
3654       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs"))
3655         {
3656         case 1: goto EXPAND_FAILED_CURLY;
3657         case 2:
3658         case 3: goto EXPAND_FAILED;
3659         }
3660
3661       /* If skipping, we don't actually do anything */
3662       if (skipping) continue;
3663
3664       /* sub_arg[0] is the address */
3665       domain = Ustrrchr(sub_arg[0],'@');
3666       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
3667         {
3668         expand_string_message = US"prvs first argument must be a qualified email address";
3669         goto EXPAND_FAILED;
3670         }
3671
3672       /* Calculate the hash. The second argument must be a single-digit
3673       key number, or unset. */
3674
3675       if (sub_arg[2] != NULL &&
3676           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
3677         {
3678         expand_string_message = US"prvs second argument must be a single digit";
3679         goto EXPAND_FAILED;
3680         }
3681
3682       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
3683       if (p == NULL)
3684         {
3685         expand_string_message = US"prvs hmac-sha1 conversion failed";
3686         goto EXPAND_FAILED;
3687         }
3688
3689       /* Now separate the domain from the local part */
3690       *domain++ = '\0';
3691
3692       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
3693       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
3694       string_cat(yield,&size,&ptr,US"/",1);
3695       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
3696       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
3697       string_cat(yield,&size,&ptr,p,6);
3698       string_cat(yield,&size,&ptr,US"@",1);
3699       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
3700
3701       continue;
3702       }
3703
3704     /* Check a prvs-encoded address for validity */
3705
3706     case EITEM_PRVSCHECK:
3707       {
3708       uschar *sub_arg[3];
3709       int mysize = 0, myptr = 0;
3710       const pcre *re;
3711       uschar *p;
3712
3713       /* TF: Ugliness: We want to expand parameter 1 first, then set
3714          up expansion variables that are used in the expansion of
3715          parameter 2. So we clone the string for the first
3716          expansion, where we only expand parameter 1.
3717
3718          PH: Actually, that isn't necessary. The read_subs() function is
3719          designed to work this way for the ${if and ${lookup expansions. I've
3720          tidied the code.
3721       */
3722
3723       /* Reset expansion variables */
3724       prvscheck_result = NULL;
3725       prvscheck_address = NULL;
3726       prvscheck_keynum = NULL;
3727
3728       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
3729         {
3730         case 1: goto EXPAND_FAILED_CURLY;
3731         case 2:
3732         case 3: goto EXPAND_FAILED;
3733         }
3734
3735       re = regex_must_compile(US"^prvs\\=(.+)\\/([0-9])([0-9]{3})([A-F0-9]{6})\\@(.+)$",
3736                               TRUE,FALSE);
3737
3738       if (regex_match_and_setup(re,sub_arg[0],0,-1))
3739         {
3740         uschar *local_part = string_copyn(expand_nstring[1],expand_nlength[1]);
3741         uschar *key_num = string_copyn(expand_nstring[2],expand_nlength[2]);
3742         uschar *daystamp = string_copyn(expand_nstring[3],expand_nlength[3]);
3743         uschar *hash = string_copyn(expand_nstring[4],expand_nlength[4]);
3744         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
3745
3746         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
3747         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
3748         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
3749         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
3750         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
3751
3752         /* Set up expansion variables */
3753         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
3754         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
3755         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
3756         prvscheck_address[myptr] = '\0';
3757         prvscheck_keynum = string_copy(key_num);
3758
3759         /* Now expand the second argument */
3760         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
3761           {
3762           case 1: goto EXPAND_FAILED_CURLY;
3763           case 2:
3764           case 3: goto EXPAND_FAILED;
3765           }
3766
3767         /* Now we have the key and can check the address. */
3768
3769         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
3770           daystamp);
3771
3772         if (p == NULL)
3773           {
3774           expand_string_message = US"hmac-sha1 conversion failed";
3775           goto EXPAND_FAILED;
3776           }
3777
3778         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
3779         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
3780
3781         if (Ustrcmp(p,hash) == 0)
3782           {
3783           /* Success, valid BATV address. Now check the expiry date. */
3784           uschar *now = prvs_daystamp(0);
3785           unsigned int inow = 0,iexpire = 1;
3786
3787           (void)sscanf(CS now,"%u",&inow);
3788           (void)sscanf(CS daystamp,"%u",&iexpire);
3789
3790           /* When "iexpire" is < 7, a "flip" has occured.
3791              Adjust "inow" accordingly. */
3792           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
3793
3794           if (iexpire > inow)
3795             {
3796             prvscheck_result = US"1";
3797             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
3798             }
3799             else
3800             {
3801             prvscheck_result = NULL;
3802             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
3803             }
3804           }
3805         else
3806           {
3807           prvscheck_result = NULL;
3808           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
3809           }
3810
3811         /* Now expand the final argument. We leave this till now so that
3812         it can include $prvscheck_result. */
3813
3814         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs"))
3815           {
3816           case 1: goto EXPAND_FAILED_CURLY;
3817           case 2:
3818           case 3: goto EXPAND_FAILED;
3819           }
3820
3821         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
3822           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
3823         else
3824           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
3825
3826         /* Reset the "internal" variables afterwards, because they are in
3827         dynamic store that will be reclaimed if the expansion succeeded. */
3828
3829         prvscheck_address = NULL;
3830         prvscheck_keynum = NULL;
3831         }
3832       else
3833         {
3834         /* Does not look like a prvs encoded address, return the empty string.
3835            We need to make sure all subs are expanded first, so as to skip over
3836            the entire item. */
3837
3838         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs"))
3839           {
3840           case 1: goto EXPAND_FAILED_CURLY;
3841           case 2:
3842           case 3: goto EXPAND_FAILED;
3843           }
3844         }
3845
3846       continue;
3847       }
3848
3849     /* Handle "readfile" to insert an entire file */
3850
3851     case EITEM_READFILE:
3852       {
3853       FILE *f;
3854       uschar *sub_arg[2];
3855
3856       if ((expand_forbid & RDO_READFILE) != 0)
3857         {
3858         expand_string_message = US"file insertions are not permitted";
3859         goto EXPAND_FAILED;
3860         }
3861
3862       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
3863         {
3864         case 1: goto EXPAND_FAILED_CURLY;
3865         case 2:
3866         case 3: goto EXPAND_FAILED;
3867         }
3868
3869       /* If skipping, we don't actually do anything */
3870
3871       if (skipping) continue;
3872
3873       /* Open the file and read it */
3874
3875       f = Ufopen(sub_arg[0], "rb");
3876       if (f == NULL)
3877         {
3878         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
3879         goto EXPAND_FAILED;
3880         }
3881
3882       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
3883       (void)fclose(f);
3884       continue;
3885       }
3886
3887     /* Handle "readsocket" to insert data from a Unix domain socket */
3888
3889     case EITEM_READSOCK:
3890       {
3891       int fd;
3892       int timeout = 5;
3893       int save_ptr = ptr;
3894       FILE *f;
3895       struct sockaddr_un sockun;         /* don't call this "sun" ! */
3896       uschar *arg;
3897       uschar *sub_arg[4];
3898
3899       if ((expand_forbid & RDO_READSOCK) != 0)
3900         {
3901         expand_string_message = US"socket insertions are not permitted";
3902         goto EXPAND_FAILED;
3903         }
3904
3905       /* Read up to 4 arguments, but don't do the end of item check afterwards,
3906       because there may be a string for expansion on failure. */
3907
3908       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
3909         {
3910         case 1: goto EXPAND_FAILED_CURLY;
3911         case 2:                             /* Won't occur: no end check */
3912         case 3: goto EXPAND_FAILED;
3913         }
3914
3915       /* Sort out timeout, if given */
3916
3917       if (sub_arg[2] != NULL)
3918         {
3919         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
3920         if (timeout < 0)
3921           {
3922           expand_string_message = string_sprintf("bad time value %s",
3923             sub_arg[2]);
3924           goto EXPAND_FAILED;
3925           }
3926         }
3927       else sub_arg[3] = NULL;                     /* No eol if no timeout */
3928
3929       /* If skipping, we don't actually do anything. Otherwise, arrange to
3930       connect to either an IP or a Unix socket. */
3931
3932       if (!skipping)
3933         {
3934         /* Handle an IP (internet) domain */
3935
3936         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
3937           {
3938           BOOL connected = FALSE;
3939           int namelen, port;
3940           host_item shost;
3941           host_item *h;
3942           uschar *server_name = sub_arg[0] + 5;
3943           uschar *port_name = Ustrrchr(server_name, ':');
3944
3945           /* Sort out the port */
3946
3947           if (port_name == NULL)
3948             {
3949             expand_string_message =
3950               string_sprintf("missing port for readsocket %s", sub_arg[0]);
3951             goto EXPAND_FAILED;
3952             }
3953           *port_name++ = 0;           /* Terminate server name */
3954
3955           if (isdigit(*port_name))
3956             {
3957             uschar *end;
3958             port = Ustrtol(port_name, &end, 0);
3959             if (end != port_name + Ustrlen(port_name))
3960               {
3961               expand_string_message =
3962                 string_sprintf("invalid port number %s", port_name);
3963               goto EXPAND_FAILED;
3964               }
3965             }
3966           else
3967             {
3968             struct servent *service_info = getservbyname(CS port_name, "tcp");
3969             if (service_info == NULL)
3970               {
3971               expand_string_message = string_sprintf("unknown port \"%s\"",
3972                 port_name);
3973               goto EXPAND_FAILED;
3974               }
3975             port = ntohs(service_info->s_port);
3976             }
3977
3978           /* Sort out the server. */
3979
3980           shost.next = NULL;
3981           shost.address = NULL;
3982           shost.port = port;
3983           shost.mx = -1;
3984
3985           namelen = Ustrlen(server_name);
3986
3987           /* Anything enclosed in [] must be an IP address. */
3988
3989           if (server_name[0] == '[' &&
3990               server_name[namelen - 1] == ']')
3991             {
3992             server_name[namelen - 1] = 0;
3993             server_name++;
3994             if (string_is_ip_address(server_name, NULL) == 0)
3995               {
3996               expand_string_message =
3997                 string_sprintf("malformed IP address \"%s\"", server_name);
3998               goto EXPAND_FAILED;
3999               }
4000             shost.name = shost.address = server_name;
4001             }
4002
4003           /* Otherwise check for an unadorned IP address */
4004
4005           else if (string_is_ip_address(server_name, NULL) != 0)
4006             shost.name = shost.address = server_name;
4007
4008           /* Otherwise lookup IP address(es) from the name */
4009
4010           else
4011             {
4012             shost.name = server_name;
4013             if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
4014                 FALSE) != HOST_FOUND)
4015               {
4016               expand_string_message =
4017                 string_sprintf("no IP address found for host %s", shost.name);
4018               goto EXPAND_FAILED;
4019               }
4020             }
4021
4022           /* Try to connect to the server - test each IP till one works */
4023
4024           for (h = &shost; h != NULL; h = h->next)
4025             {
4026             int af = (Ustrchr(h->address, ':') != 0)? AF_INET6 : AF_INET;
4027             if ((fd = ip_socket(SOCK_STREAM, af)) == -1)
4028               {
4029               expand_string_message = string_sprintf("failed to create socket: "
4030                 "%s", strerror(errno));
4031               goto SOCK_FAIL;
4032               }
4033
4034             if (ip_connect(fd, af, h->address, port, timeout) == 0)
4035               {
4036               connected = TRUE;
4037               break;
4038               }
4039             }
4040
4041           if (!connected)
4042             {
4043             expand_string_message = string_sprintf("failed to connect to "
4044               "socket %s: couldn't connect to any host", sub_arg[0],
4045               strerror(errno));
4046             goto SOCK_FAIL;
4047             }
4048           }
4049
4050         /* Handle a Unix domain socket */
4051
4052         else
4053           {
4054           int rc;
4055           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4056             {
4057             expand_string_message = string_sprintf("failed to create socket: %s",
4058               strerror(errno));
4059             goto SOCK_FAIL;
4060             }
4061
4062           sockun.sun_family = AF_UNIX;
4063           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4064             sub_arg[0]);
4065
4066           sigalrm_seen = FALSE;
4067           alarm(timeout);
4068           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4069           alarm(0);
4070           if (sigalrm_seen)
4071             {
4072             expand_string_message = US "socket connect timed out";
4073             goto SOCK_FAIL;
4074             }
4075           if (rc < 0)
4076             {
4077             expand_string_message = string_sprintf("failed to connect to socket "
4078               "%s: %s", sub_arg[0], strerror(errno));
4079             goto SOCK_FAIL;
4080             }
4081           }
4082
4083         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4084
4085         /* Write the request string, if not empty */
4086
4087         if (sub_arg[1][0] != 0)
4088           {
4089           int len = Ustrlen(sub_arg[1]);
4090           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4091             sub_arg[1]);
4092           if (write(fd, sub_arg[1], len) != len)
4093             {
4094             expand_string_message = string_sprintf("request write to socket "
4095               "failed: %s", strerror(errno));
4096             goto SOCK_FAIL;
4097             }
4098           }
4099
4100         /* Shut down the sending side of the socket. This helps some servers to
4101         recognise that it is their turn to do some work. Just in case some
4102         system doesn't have this function, make it conditional. */
4103
4104         #ifdef SHUT_WR
4105         shutdown(fd, SHUT_WR);
4106         #endif
4107
4108         /* Now we need to read from the socket, under a timeout. The function
4109         that reads a file can be used. */
4110
4111         f = fdopen(fd, "rb");
4112         sigalrm_seen = FALSE;
4113         alarm(timeout);
4114         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4115         alarm(0);
4116         (void)fclose(f);
4117
4118         /* After a timeout, we restore the pointer in the result, that is,
4119         make sure we add nothing from the socket. */
4120
4121         if (sigalrm_seen)
4122           {
4123           ptr = save_ptr;
4124           expand_string_message = US "socket read timed out";
4125           goto SOCK_FAIL;
4126           }
4127         }
4128
4129       /* The whole thing has worked (or we were skipping). If there is a
4130       failure string following, we need to skip it. */
4131
4132       if (*s == '{')
4133         {
4134         if (expand_string_internal(s+1, TRUE, &s, TRUE) == NULL)
4135           goto EXPAND_FAILED;
4136         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4137         while (isspace(*s)) s++;
4138         }
4139       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4140       continue;
4141
4142       /* Come here on failure to create socket, connect socket, write to the
4143       socket, or timeout on reading. If another substring follows, expand and
4144       use it. Otherwise, those conditions give expand errors. */
4145
4146       SOCK_FAIL:
4147       if (*s != '{') goto EXPAND_FAILED;
4148       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4149       arg = expand_string_internal(s+1, TRUE, &s, FALSE);
4150       if (arg == NULL) goto EXPAND_FAILED;
4151       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4152       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4153       while (isspace(*s)) s++;
4154       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4155       continue;
4156       }
4157
4158     /* Handle "run" to execute a program. */
4159
4160     case EITEM_RUN:
4161       {
4162       FILE *f;
4163       uschar *arg;
4164       uschar **argv;
4165       pid_t pid;
4166       int fd_in, fd_out;
4167       int lsize = 0;
4168       int lptr = 0;
4169
4170       if ((expand_forbid & RDO_RUN) != 0)
4171         {
4172         expand_string_message = US"running a command is not permitted";
4173         goto EXPAND_FAILED;
4174         }
4175
4176       while (isspace(*s)) s++;
4177       if (*s != '{') goto EXPAND_FAILED_CURLY;
4178       arg = expand_string_internal(s+1, TRUE, &s, skipping);
4179       if (arg == NULL) goto EXPAND_FAILED;
4180       while (isspace(*s)) s++;
4181       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4182
4183       if (skipping)   /* Just pretend it worked when we're skipping */
4184         {
4185         runrc = 0;
4186         }
4187       else
4188         {
4189         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4190             arg,                                /* raw command */
4191             FALSE,                              /* don't expand the arguments */
4192             0,                                  /* not relevant when... */
4193             NULL,                               /* no transporting address */
4194             US"${run} expansion",               /* for error messages */
4195             &expand_string_message))            /* where to put error message */
4196           {
4197           goto EXPAND_FAILED;
4198           }
4199
4200         /* Create the child process, making it a group leader. */
4201
4202         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4203
4204         if (pid < 0)
4205           {
4206           expand_string_message =
4207             string_sprintf("couldn't create child process: %s", strerror(errno));
4208           goto EXPAND_FAILED;
4209           }
4210
4211         /* Nothing is written to the standard input. */
4212
4213         (void)close(fd_in);
4214
4215         /* Wait for the process to finish, applying the timeout, and inspect its
4216         return code for serious disasters. Simple non-zero returns are passed on.
4217         */
4218
4219         if ((runrc = child_close(pid, 60)) < 0)
4220           {
4221           if (runrc == -256)
4222             {
4223             expand_string_message = string_sprintf("command timed out");
4224             killpg(pid, SIGKILL);       /* Kill the whole process group */
4225             }
4226
4227           else if (runrc == -257)
4228             expand_string_message = string_sprintf("wait() failed: %s",
4229               strerror(errno));
4230
4231           else
4232             expand_string_message = string_sprintf("command killed by signal %d",
4233               -runrc);
4234
4235           goto EXPAND_FAILED;
4236           }
4237
4238         /* Read the pipe to get the command's output into $value (which is kept
4239         in lookup_value). */
4240
4241         f = fdopen(fd_out, "rb");
4242         lookup_value = NULL;
4243         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4244         (void)fclose(f);
4245         }
4246
4247       /* Process the yes/no strings; $value may be useful in both cases */
4248
4249       switch(process_yesno(
4250                skipping,                     /* were previously skipping */
4251                runrc == 0,                   /* success/failure indicator */
4252                lookup_value,                 /* value to reset for string2 */
4253                &s,                           /* input pointer */
4254                &yield,                       /* output pointer */
4255                &size,                        /* output size */
4256                &ptr,                         /* output current point */
4257                US"run"))                     /* condition type */
4258         {
4259         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4260         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4261         }
4262
4263       continue;
4264       }
4265
4266     /* Handle character translation for "tr" */
4267
4268     case EITEM_TR:
4269       {
4270       int oldptr = ptr;
4271       int o2m;
4272       uschar *sub[3];
4273
4274       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
4275         {
4276         case 1: goto EXPAND_FAILED_CURLY;
4277         case 2:
4278         case 3: goto EXPAND_FAILED;
4279         }
4280
4281       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4282       o2m = Ustrlen(sub[2]) - 1;
4283
4284       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4285         {
4286         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4287         if (m != NULL)
4288           {
4289           int o = m - sub[1];
4290           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4291           }
4292         }
4293
4294       continue;
4295       }
4296
4297     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4298     expanded arguments. */
4299
4300     case EITEM_HASH:
4301     case EITEM_LENGTH:
4302     case EITEM_NHASH:
4303     case EITEM_SUBSTR:
4304       {
4305       int i;
4306       int len;
4307       uschar *ret;
4308       int val[2] = { 0, -1 };
4309       uschar *sub[3];
4310
4311       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4312       Ensure that sub[2] is set in the ${length case. */
4313
4314       sub[2] = NULL;
4315       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4316              TRUE, name))
4317         {
4318         case 1: goto EXPAND_FAILED_CURLY;
4319         case 2:
4320         case 3: goto EXPAND_FAILED;
4321         }
4322
4323       /* Juggle the arguments if there are only two of them: always move the
4324       string to the last position and make ${length{n}{str}} equivalent to
4325       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4326
4327       if (sub[2] == NULL)
4328         {
4329         sub[2] = sub[1];
4330         sub[1] = NULL;
4331         if (item_type == EITEM_LENGTH)
4332           {
4333           sub[1] = sub[0];
4334           sub[0] = NULL;
4335           }
4336         }
4337
4338       for (i = 0; i < 2; i++)
4339         {
4340         if (sub[i] == NULL) continue;
4341         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4342         if (*ret != 0 || (i != 0 && val[i] < 0))
4343           {
4344           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4345             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4346           goto EXPAND_FAILED;
4347           }
4348         }
4349
4350       ret =
4351         (item_type == EITEM_HASH)?
4352           compute_hash(sub[2], val[0], val[1], &len) :
4353         (item_type == EITEM_NHASH)?
4354           compute_nhash(sub[2], val[0], val[1], &len) :
4355           extract_substr(sub[2], val[0], val[1], &len);
4356
4357       if (ret == NULL) goto EXPAND_FAILED;
4358       yield = string_cat(yield, &size, &ptr, ret, len);
4359       continue;
4360       }
4361
4362     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4363     This code originally contributed by Steve Haslam. It currently supports
4364     the use of MD5 and SHA-1 hashes.
4365
4366     We need some workspace that is large enough to handle all the supported
4367     hash types. Use macros to set the sizes rather than be too elaborate. */
4368
4369     #define MAX_HASHLEN      20
4370     #define MAX_HASHBLOCKLEN 64
4371
4372     case EITEM_HMAC:
4373       {
4374       uschar *sub[3];
4375       md5 md5_base;
4376       sha1 sha1_base;
4377       void *use_base;
4378       int type, i;
4379       int hashlen;      /* Number of octets for the hash algorithm's output */
4380       int hashblocklen; /* Number of octets the hash algorithm processes */
4381       uschar *keyptr, *p;
4382       unsigned int keylen;
4383
4384       uschar keyhash[MAX_HASHLEN];
4385       uschar innerhash[MAX_HASHLEN];
4386       uschar finalhash[MAX_HASHLEN];
4387       uschar finalhash_hex[2*MAX_HASHLEN];
4388       uschar innerkey[MAX_HASHBLOCKLEN];
4389       uschar outerkey[MAX_HASHBLOCKLEN];
4390
4391       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
4392         {
4393         case 1: goto EXPAND_FAILED_CURLY;
4394         case 2:
4395         case 3: goto EXPAND_FAILED;
4396         }
4397
4398       if (Ustrcmp(sub[0], "md5") == 0)
4399         {
4400         type = HMAC_MD5;
4401         use_base = &md5_base;
4402         hashlen = 16;
4403         hashblocklen = 64;
4404         }
4405       else if (Ustrcmp(sub[0], "sha1") == 0)
4406         {
4407         type = HMAC_SHA1;
4408         use_base = &sha1_base;
4409         hashlen = 20;
4410         hashblocklen = 64;
4411         }
4412       else
4413         {
4414         expand_string_message =
4415           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
4416         goto EXPAND_FAILED;
4417         }
4418
4419       keyptr = sub[1];
4420       keylen = Ustrlen(keyptr);
4421
4422       /* If the key is longer than the hash block length, then hash the key
4423       first */
4424
4425       if (keylen > hashblocklen)
4426         {
4427         chash_start(type, use_base);
4428         chash_end(type, use_base, keyptr, keylen, keyhash);
4429         keyptr = keyhash;
4430         keylen = hashlen;
4431         }
4432
4433       /* Now make the inner and outer key values */
4434
4435       memset(innerkey, 0x36, hashblocklen);
4436       memset(outerkey, 0x5c, hashblocklen);
4437
4438       for (i = 0; i < keylen; i++)
4439         {
4440         innerkey[i] ^= keyptr[i];
4441         outerkey[i] ^= keyptr[i];
4442         }
4443
4444       /* Now do the hashes */
4445
4446       chash_start(type, use_base);
4447       chash_mid(type, use_base, innerkey);
4448       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
4449
4450       chash_start(type, use_base);
4451       chash_mid(type, use_base, outerkey);
4452       chash_end(type, use_base, innerhash, hashlen, finalhash);
4453
4454       /* Encode the final hash as a hex string */
4455
4456       p = finalhash_hex;
4457       for (i = 0; i < hashlen; i++)
4458         {
4459         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
4460         *p++ = hex_digits[finalhash[i] & 0x0f];
4461         }
4462
4463       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
4464         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
4465
4466       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
4467       }
4468
4469     continue;
4470
4471     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
4472     We have to save the numerical variables and restore them afterwards. */
4473
4474     case EITEM_SG:
4475       {
4476       const pcre *re;
4477       int moffset, moffsetextra, slen;
4478       int roffset;
4479       int emptyopt;
4480       const uschar *rerror;
4481       uschar *subject;
4482       uschar *sub[3];
4483       int save_expand_nmax =
4484         save_expand_strings(save_expand_nstring, save_expand_nlength);
4485
4486       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
4487         {
4488         case 1: goto EXPAND_FAILED_CURLY;
4489         case 2:
4490         case 3: goto EXPAND_FAILED;
4491         }
4492
4493       /* Compile the regular expression */
4494
4495       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
4496         NULL);
4497
4498       if (re == NULL)
4499         {
4500         expand_string_message = string_sprintf("regular expression error in "
4501           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
4502         goto EXPAND_FAILED;
4503         }
4504
4505       /* Now run a loop to do the substitutions as often as necessary. It ends
4506       when there are no more matches. Take care over matches of the null string;
4507       do the same thing as Perl does. */
4508
4509       subject = sub[0];
4510       slen = Ustrlen(sub[0]);
4511       moffset = moffsetextra = 0;
4512       emptyopt = 0;
4513
4514       for (;;)
4515         {
4516         int ovector[3*(EXPAND_MAXN+1)];
4517         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
4518           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
4519         int nn;
4520         uschar *insert;
4521
4522         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
4523         is not necessarily the end. We want to repeat the match from one
4524         character further along, but leaving the basic offset the same (for
4525         copying below). We can't be at the end of the string - that was checked
4526         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
4527         finished; copy the remaining string and end the loop. */
4528
4529         if (n < 0)
4530           {
4531           if (emptyopt != 0)
4532             {
4533             moffsetextra = 1;
4534             emptyopt = 0;
4535             continue;
4536             }
4537           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
4538           break;
4539           }
4540
4541         /* Match - set up for expanding the replacement. */
4542
4543         if (n == 0) n = EXPAND_MAXN + 1;
4544         expand_nmax = 0;
4545         for (nn = 0; nn < n*2; nn += 2)
4546           {
4547           expand_nstring[expand_nmax] = subject + ovector[nn];
4548           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
4549           }
4550         expand_nmax--;
4551
4552         /* Copy the characters before the match, plus the expanded insertion. */
4553
4554         yield = string_cat(yield, &size, &ptr, subject + moffset,
4555           ovector[0] - moffset);
4556         insert = expand_string(sub[2]);
4557         if (insert == NULL) goto EXPAND_FAILED;
4558         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
4559
4560         moffset = ovector[1];
4561         moffsetextra = 0;
4562         emptyopt = 0;
4563
4564         /* If we have matched an empty string, first check to see if we are at
4565         the end of the subject. If so, the loop is over. Otherwise, mimic
4566         what Perl's /g options does. This turns out to be rather cunning. First
4567         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
4568         string at the same point. If this fails (picked up above) we advance to
4569         the next character. */
4570
4571         if (ovector[0] == ovector[1])
4572           {
4573           if (ovector[0] == slen) break;
4574           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
4575           }
4576         }
4577
4578       /* All done - restore numerical variables. */
4579
4580       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4581         save_expand_nlength);
4582       continue;
4583       }
4584
4585     /* Handle keyed and numbered substring extraction. If the first argument
4586     consists entirely of digits, then a numerical extraction is assumed. */
4587
4588     case EITEM_EXTRACT:
4589       {
4590       int i;
4591       int j = 2;
4592       int field_number = 1;
4593       BOOL field_number_set = FALSE;
4594       uschar *save_lookup_value = lookup_value;
4595       uschar *sub[3];
4596       int save_expand_nmax =
4597         save_expand_strings(save_expand_nstring, save_expand_nlength);
4598
4599       /* Read the arguments */
4600
4601       for (i = 0; i < j; i++)
4602         {
4603         while (isspace(*s)) s++;
4604         if (*s == '{')
4605           {
4606           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping);
4607           if (sub[i] == NULL) goto EXPAND_FAILED;
4608           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4609
4610           /* After removal of leading and trailing white space, the first
4611           argument must not be empty; if it consists entirely of digits
4612           (optionally preceded by a minus sign), this is a numerical
4613           extraction, and we expect 3 arguments. */
4614
4615           if (i == 0)
4616             {
4617             int len;
4618             int x = 0;
4619             uschar *p = sub[0];
4620
4621             while (isspace(*p)) p++;
4622             sub[0] = p;
4623
4624             len = Ustrlen(p);
4625             while (len > 0 && isspace(p[len-1])) len--;
4626             p[len] = 0;
4627
4628             if (*p == 0)
4629               {
4630               expand_string_message = US"first argument of \"extract\" must "
4631                 "not be empty";
4632               goto EXPAND_FAILED;
4633               }
4634
4635             if (*p == '-')
4636               {
4637               field_number = -1;
4638               p++;
4639               }
4640             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
4641             if (*p == 0)
4642               {
4643               field_number *= x;
4644               j = 3;               /* Need 3 args */
4645               field_number_set = TRUE;
4646               }
4647             }
4648           }
4649         else goto EXPAND_FAILED_CURLY;
4650         }
4651
4652       /* Extract either the numbered or the keyed substring into $value. If
4653       skipping, just pretend the extraction failed. */
4654
4655       lookup_value = skipping? NULL : field_number_set?
4656         expand_gettokened(field_number, sub[1], sub[2]) :
4657         expand_getkeyed(sub[0], sub[1]);
4658
4659       /* If no string follows, $value gets substituted; otherwise there can
4660       be yes/no strings, as for lookup or if. */
4661
4662       switch(process_yesno(
4663                skipping,                     /* were previously skipping */
4664                lookup_value != NULL,         /* success/failure indicator */
4665                save_lookup_value,            /* value to reset for string2 */
4666                &s,                           /* input pointer */
4667                &yield,                       /* output pointer */
4668                &size,                        /* output size */
4669                &ptr,                         /* output current point */
4670                US"extract"))                 /* condition type */
4671         {
4672         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4673         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4674         }
4675
4676       /* All done - restore numerical variables. */
4677
4678       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4679         save_expand_nlength);
4680
4681       continue;
4682       }
4683
4684
4685     /* If ${dlfunc support is configured, handle calling dynamically-loaded
4686     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
4687     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
4688     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
4689
4690     #define EXPAND_DLFUNC_MAX_ARGS 8
4691
4692     case EITEM_DLFUNC:
4693     #ifndef EXPAND_DLFUNC
4694     expand_string_message = US"\"${dlfunc\" encountered, but this facility "
4695       "is not included in this binary";
4696     goto EXPAND_FAILED;
4697
4698     #else   /* EXPAND_DLFUNC */
4699       {
4700       tree_node *t;
4701       exim_dlfunc_t *func;
4702       uschar *result;
4703       int status, argc;
4704       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
4705
4706       if ((expand_forbid & RDO_DLFUNC) != 0)
4707         {
4708         expand_string_message =
4709           US"dynamically-loaded functions are not permitted";
4710         goto EXPAND_FAILED;
4711         }
4712
4713       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
4714            TRUE, US"dlfunc"))
4715         {
4716         case 1: goto EXPAND_FAILED_CURLY;
4717         case 2:
4718         case 3: goto EXPAND_FAILED;
4719         }
4720
4721       /* If skipping, we don't actually do anything */
4722
4723       if (skipping) continue;
4724
4725       /* Look up the dynamically loaded object handle in the tree. If it isn't
4726       found, dlopen() the file and put the handle in the tree for next time. */
4727
4728       t = tree_search(dlobj_anchor, argv[0]);
4729       if (t == NULL)
4730         {
4731         void *handle = dlopen(CS argv[0], RTLD_LAZY);
4732         if (handle == NULL)
4733           {
4734           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
4735             argv[0], dlerror());
4736           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
4737           goto EXPAND_FAILED;
4738           }
4739         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
4740         Ustrcpy(t->name, argv[0]);
4741         t->data.ptr = handle;
4742         (void)tree_insertnode(&dlobj_anchor, t);
4743         }
4744
4745       /* Having obtained the dynamically loaded object handle, look up the
4746       function pointer. */
4747
4748       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
4749       if (func == NULL)
4750         {
4751         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
4752           "%s", argv[1], argv[0], dlerror());
4753         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
4754         goto EXPAND_FAILED;
4755         }
4756
4757       /* Call the function and work out what to do with the result. If it
4758       returns OK, we have a replacement string; if it returns DEFER then
4759       expansion has failed in a non-forced manner; if it returns FAIL then
4760       failure was forced; if it returns ERROR or any other value there's a
4761       problem, so panic slightly. */
4762
4763       result = NULL;
4764       for (argc = 0; argv[argc] != NULL; argc++);
4765       status = func(&result, argc - 2, &argv[2]);
4766       if(status == OK)
4767         {
4768         if (result == NULL) result = US"";
4769         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
4770         continue;
4771         }
4772       else
4773         {
4774         expand_string_message = result == NULL ? US"(no message)" : result;
4775         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
4776           else if(status != FAIL)
4777             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
4778               argv[0], argv[1], status, expand_string_message);
4779         goto EXPAND_FAILED;
4780         }
4781       }
4782     #endif /* EXPAND_DLFUNC */
4783     }
4784
4785   /* Control reaches here if the name is not recognized as one of the more
4786   complicated expansion items. Check for the "operator" syntax (name terminated
4787   by a colon). Some of the operators have arguments, separated by _ from the
4788   name. */
4789
4790   if (*s == ':')
4791     {
4792     int c;
4793     uschar *arg = NULL;
4794     uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping);
4795     if (sub == NULL) goto EXPAND_FAILED;
4796     s++;
4797
4798     /* Owing to an historical mis-design, an underscore may be part of the
4799     operator name, or it may introduce arguments.  We therefore first scan the
4800     table of names that contain underscores. If there is no match, we cut off
4801     the arguments and then scan the main table. */
4802
4803     c = chop_match(name, op_table_underscore,
4804       sizeof(op_table_underscore)/sizeof(uschar *));
4805
4806     if (c < 0)
4807       {
4808       arg = Ustrchr(name, '_');
4809       if (arg != NULL) *arg = 0;
4810       c = chop_match(name, op_table_main,
4811         sizeof(op_table_main)/sizeof(uschar *));
4812       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
4813       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
4814       }
4815
4816     /* If we are skipping, we don't need to perform the operation at all.
4817     This matters for operations like "mask", because the data may not be
4818     in the correct format when skipping. For example, the expression may test
4819     for the existence of $sender_host_address before trying to mask it. For
4820     other operations, doing them may not fail, but it is a waste of time. */
4821
4822     if (skipping && c >= 0) continue;
4823
4824     /* Otherwise, switch on the operator type */
4825
4826     switch(c)
4827       {
4828       case EOP_BASE62:
4829         {
4830         uschar *t;
4831         unsigned long int n = Ustrtoul(sub, &t, 10);
4832         if (*t != 0)
4833           {
4834           expand_string_message = string_sprintf("argument for base62 "
4835             "operator is \"%s\", which is not a decimal number", sub);
4836           goto EXPAND_FAILED;
4837           }
4838         t = string_base62(n);
4839         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
4840         continue;
4841         }
4842
4843       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
4844
4845       case EOP_BASE62D:
4846         {
4847         uschar buf[16];
4848         uschar *tt = sub;
4849         unsigned long int n = 0;
4850         while (*tt != 0)
4851           {
4852           uschar *t = Ustrchr(base62_chars, *tt++);
4853           if (t == NULL)
4854             {
4855             expand_string_message = string_sprintf("argument for base62d "
4856               "operator is \"%s\", which is not a base %d number", sub,
4857               BASE_62);
4858             goto EXPAND_FAILED;
4859             }
4860           n = n * BASE_62 + (t - base62_chars);
4861           }
4862         (void)sprintf(CS buf, "%ld", n);
4863         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
4864         continue;
4865         }
4866
4867       case EOP_EXPAND:
4868         {
4869         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping);
4870         if (expanded == NULL)
4871           {
4872           expand_string_message =
4873             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
4874               expand_string_message);
4875           goto EXPAND_FAILED;
4876           }
4877         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
4878         continue;
4879         }
4880
4881       case EOP_LC:
4882         {
4883         int count = 0;
4884         uschar *t = sub - 1;
4885         while (*(++t) != 0) { *t = tolower(*t); count++; }
4886         yield = string_cat(yield, &size, &ptr, sub, count);
4887         continue;
4888         }
4889
4890       case EOP_UC:
4891         {
4892         int count = 0;
4893         uschar *t = sub - 1;
4894         while (*(++t) != 0) { *t = toupper(*t); count++; }
4895         yield = string_cat(yield, &size, &ptr, sub, count);
4896         continue;
4897         }
4898
4899       case EOP_MD5:
4900         {
4901         md5 base;
4902         uschar digest[16];
4903         int j;
4904         char st[33];
4905         md5_start(&base);
4906         md5_end(&base, sub, Ustrlen(sub), digest);
4907         for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
4908         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
4909         continue;
4910         }
4911
4912       case EOP_SHA1:
4913         {
4914         sha1 base;
4915         uschar digest[20];
4916         int j;
4917         char st[41];
4918         sha1_start(&base);
4919         sha1_end(&base, sub, Ustrlen(sub), digest);
4920         for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
4921         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
4922         continue;
4923         }
4924
4925       /* Convert hex encoding to base64 encoding */
4926
4927       case EOP_HEX2B64:
4928         {
4929         int c = 0;
4930         int b = -1;
4931         uschar *in = sub;
4932         uschar *out = sub;
4933         uschar *enc;
4934
4935         for (enc = sub; *enc != 0; enc++)
4936           {
4937           if (!isxdigit(*enc))
4938             {
4939             expand_string_message = string_sprintf("\"%s\" is not a hex "
4940               "string", sub);
4941             goto EXPAND_FAILED;
4942             }
4943           c++;
4944           }
4945
4946         if ((c & 1) != 0)
4947           {
4948           expand_string_message = string_sprintf("\"%s\" contains an odd "
4949             "number of characters", sub);
4950           goto EXPAND_FAILED;
4951           }
4952
4953         while ((c = *in++) != 0)
4954           {
4955           if (isdigit(c)) c -= '0';
4956           else c = toupper(c) - 'A' + 10;
4957           if (b == -1)
4958             {
4959             b = c << 4;
4960             }
4961           else
4962             {
4963             *out++ = b | c;
4964             b = -1;
4965             }
4966           }
4967
4968         enc = auth_b64encode(sub, out - sub);
4969         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
4970         continue;
4971         }
4972
4973       /* mask applies a mask to an IP address; for example the result of
4974       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
4975
4976       case EOP_MASK:
4977         {
4978         int count;
4979         uschar *endptr;
4980         int binary[4];
4981         int mask, maskoffset;
4982         int type = string_is_ip_address(sub, &maskoffset);
4983         uschar buffer[64];
4984
4985         if (type == 0)
4986           {
4987           expand_string_message = string_sprintf("\"%s\" is not an IP address",
4988            sub);
4989           goto EXPAND_FAILED;
4990           }
4991
4992         if (maskoffset == 0)
4993           {
4994           expand_string_message = string_sprintf("missing mask value in \"%s\"",
4995             sub);
4996           goto EXPAND_FAILED;
4997           }
4998
4999         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
5000
5001         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
5002           {
5003           expand_string_message = string_sprintf("mask value too big in \"%s\"",
5004             sub);
5005           goto EXPAND_FAILED;
5006           }
5007
5008         /* Convert the address to binary integer(s) and apply the mask */
5009
5010         sub[maskoffset] = 0;
5011         count = host_aton(sub, binary);
5012         host_mask(count, binary, mask);
5013
5014         /* Convert to masked textual format and add to output. */
5015
5016         yield = string_cat(yield, &size, &ptr, buffer,
5017           host_nmtoa(count, binary, mask, buffer, '.'));
5018         continue;
5019         }
5020
5021       case EOP_ADDRESS:
5022       case EOP_LOCAL_PART:
5023       case EOP_DOMAIN:
5024         {
5025         uschar *error;
5026         int start, end, domain;
5027         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
5028           FALSE);
5029         if (t != NULL)
5030           {
5031           if (c != EOP_DOMAIN)
5032             {
5033             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
5034             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
5035             }
5036           else if (domain != 0)
5037             {
5038             domain += start;
5039             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
5040             }
5041           }
5042         continue;
5043         }
5044
5045       /* quote puts a string in quotes if it is empty or contains anything
5046       other than alphamerics, underscore, dot, or hyphen.
5047
5048       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
5049       be quoted in order to be a valid local part.
5050
5051       In both cases, newlines and carriage returns are converted into \n and \r
5052       respectively */
5053
5054       case EOP_QUOTE:
5055       case EOP_QUOTE_LOCAL_PART:
5056       if (arg == NULL)
5057         {
5058         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
5059         uschar *t = sub - 1;
5060
5061         if (c == EOP_QUOTE)
5062           {
5063           while (!needs_quote && *(++t) != 0)
5064             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
5065           }
5066         else  /* EOP_QUOTE_LOCAL_PART */
5067           {
5068           while (!needs_quote && *(++t) != 0)
5069             needs_quote = !isalnum(*t) &&
5070               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
5071               (*t != '.' || t == sub || t[1] == 0);
5072           }
5073
5074         if (needs_quote)
5075           {
5076           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5077           t = sub - 1;
5078           while (*(++t) != 0)
5079             {
5080             if (*t == '\n')
5081               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
5082             else if (*t == '\r')
5083               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
5084             else
5085               {
5086               if (*t == '\\' || *t == '"')
5087                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
5088               yield = string_cat(yield, &size, &ptr, t, 1);
5089               }
5090             }
5091           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5092           }
5093         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5094         continue;
5095         }
5096
5097       /* quote_lookuptype does lookup-specific quoting */
5098
5099       else
5100         {
5101         int n;
5102         uschar *opt = Ustrchr(arg, '_');
5103
5104         if (opt != NULL) *opt++ = 0;
5105
5106         n = search_findtype(arg, Ustrlen(arg));
5107         if (n < 0)
5108           {
5109           expand_string_message = search_error_message;
5110           goto EXPAND_FAILED;
5111           }
5112
5113         if (lookup_list[n].quote != NULL)
5114           sub = (lookup_list[n].quote)(sub, opt);
5115         else if (opt != NULL) sub = NULL;
5116
5117         if (sub == NULL)
5118           {
5119           expand_string_message = string_sprintf(
5120             "\"%s\" unrecognized after \"${quote_%s\"",
5121             opt, arg);
5122           goto EXPAND_FAILED;
5123           }
5124
5125         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5126         continue;
5127         }
5128
5129       /* rx quote sticks in \ before any non-alphameric character so that
5130       the insertion works in a regular expression. */
5131
5132       case EOP_RXQUOTE:
5133         {
5134         uschar *t = sub - 1;
5135         while (*(++t) != 0)
5136           {
5137           if (!isalnum(*t))
5138             yield = string_cat(yield, &size, &ptr, US"\\", 1);
5139           yield = string_cat(yield, &size, &ptr, t, 1);
5140           }
5141         continue;
5142         }
5143
5144       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
5145       prescribed by the RFC, if there are characters that need to be encoded */
5146
5147       case EOP_RFC2047:
5148         {
5149         uschar buffer[2048];
5150         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
5151           buffer, sizeof(buffer), FALSE);
5152         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
5153         continue;
5154         }
5155
5156       /* RFC 2047 decode */
5157
5158       case EOP_RFC2047D:
5159         {
5160         int len;
5161         uschar *error;
5162         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
5163           headers_charset, '?', &len, &error);
5164         if (error != NULL)
5165           {
5166           expand_string_message = error;
5167           goto EXPAND_FAILED;
5168           }
5169         yield = string_cat(yield, &size, &ptr, decoded, len);
5170         continue;
5171         }
5172
5173       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
5174       underscores */
5175
5176       case EOP_FROM_UTF8:
5177         {
5178         while (*sub != 0)
5179           {
5180           int c;
5181           uschar buff[4];
5182           GETUTF8INC(c, sub);
5183           if (c > 255) c = '_';
5184           buff[0] = c;
5185           yield = string_cat(yield, &size, &ptr, buff, 1);
5186           }
5187         continue;
5188         }
5189
5190       /* escape turns all non-printing characters into escape sequences. */
5191
5192       case EOP_ESCAPE:
5193         {
5194         uschar *t = string_printing(sub);
5195         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5196         continue;
5197         }
5198
5199       /* Handle numeric expression evaluation */
5200
5201       case EOP_EVAL:
5202       case EOP_EVAL10:
5203         {
5204         uschar *save_sub = sub;
5205         uschar *error = NULL;
5206         int n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
5207         if (error != NULL)
5208           {
5209           expand_string_message = string_sprintf("error in expression "
5210             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
5211               save_sub);
5212           goto EXPAND_FAILED;
5213           }
5214         sprintf(CS var_buffer, "%d", n);
5215         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
5216         continue;
5217         }
5218
5219       /* Handle time period formating */
5220
5221       case EOP_TIME_EVAL:
5222         {
5223         int n = readconf_readtime(sub, 0, FALSE);
5224         if (n < 0)
5225           {
5226           expand_string_message = string_sprintf("string \"%s\" is not an "
5227             "Exim time interval in \"%s\" operator", sub, name);
5228           goto EXPAND_FAILED;
5229           }
5230         sprintf(CS var_buffer, "%d", n);
5231         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
5232         continue;
5233         }
5234
5235       case EOP_TIME_INTERVAL:
5236         {
5237         int n;
5238         uschar *t = read_number(&n, sub);
5239         if (*t != 0) /* Not A Number*/
5240           {
5241           expand_string_message = string_sprintf("string \"%s\" is not a "
5242             "positive number in \"%s\" operator", sub, name);
5243           goto EXPAND_FAILED;
5244           }
5245         t = readconf_printtime(n);
5246         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5247         continue;
5248         }
5249
5250       /* Convert string to base64 encoding */
5251
5252       case EOP_STR2B64:
5253         {
5254         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
5255         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
5256         continue;
5257         }
5258
5259       /* strlen returns the length of the string */
5260
5261       case EOP_STRLEN:
5262         {
5263         uschar buff[24];
5264         (void)sprintf(CS buff, "%d", Ustrlen(sub));
5265         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
5266         continue;
5267         }
5268
5269       /* length_n or l_n takes just the first n characters or the whole string,
5270       whichever is the shorter;
5271
5272       substr_m_n, and s_m_n take n characters from offset m; negative m take
5273       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
5274       takes the rest, either to the right or to the left.
5275
5276       hash_n or h_n makes a hash of length n from the string, yielding n
5277       characters from the set a-z; hash_n_m makes a hash of length n, but
5278       uses m characters from the set a-zA-Z0-9.
5279
5280       nhash_n returns a single number between 0 and n-1 (in text form), while
5281       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
5282       between 0 and n-1 and the second between 0 and m-1. */
5283
5284       case EOP_LENGTH:
5285       case EOP_L:
5286       case EOP_SUBSTR:
5287       case EOP_S:
5288       case EOP_HASH:
5289       case EOP_H:
5290       case EOP_NHASH:
5291       case EOP_NH:
5292         {
5293         int sign = 1;
5294         int value1 = 0;
5295         int value2 = -1;
5296         int *pn;
5297         int len;
5298         uschar *ret;
5299
5300         if (arg == NULL)
5301           {
5302           expand_string_message = string_sprintf("missing values after %s",
5303             name);
5304           goto EXPAND_FAILED;
5305           }
5306
5307         /* "length" has only one argument, effectively being synonymous with
5308         substr_0_n. */
5309
5310         if (c == EOP_LENGTH || c == EOP_L)
5311           {
5312           pn = &value2;
5313           value2 = 0;
5314           }
5315
5316         /* The others have one or two arguments; for "substr" the first may be
5317         negative. The second being negative means "not supplied". */
5318
5319         else
5320           {
5321           pn = &value1;
5322           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
5323           }
5324
5325         /* Read up to two numbers, separated by underscores */
5326
5327         ret = arg;
5328         while (*arg != 0)
5329           {
5330           if (arg != ret && *arg == '_' && pn == &value1)
5331             {
5332             pn = &value2;
5333             value2 = 0;
5334             if (arg[1] != 0) arg++;
5335             }
5336           else if (!isdigit(*arg))
5337             {
5338             expand_string_message =
5339               string_sprintf("non-digit after underscore in \"%s\"", name);
5340             goto EXPAND_FAILED;
5341             }
5342           else *pn = (*pn)*10 + *arg++ - '0';
5343           }
5344         value1 *= sign;
5345
5346         /* Perform the required operation */
5347
5348         ret =
5349           (c == EOP_HASH || c == EOP_H)?
5350              compute_hash(sub, value1, value2, &len) :
5351           (c == EOP_NHASH || c == EOP_NH)?
5352              compute_nhash(sub, value1, value2, &len) :
5353              extract_substr(sub, value1, value2, &len);
5354
5355         if (ret == NULL) goto EXPAND_FAILED;
5356         yield = string_cat(yield, &size, &ptr, ret, len);
5357         continue;
5358         }
5359
5360       /* Stat a path */
5361
5362       case EOP_STAT:
5363         {
5364         uschar *s;
5365         uschar smode[12];
5366         uschar **modetable[3];
5367         int i;
5368         mode_t mode;
5369         struct stat st;
5370
5371         if ((expand_forbid & RDO_EXISTS) != 0)
5372           {
5373           expand_string_message = US"Use of the stat() expansion is not permitted";
5374           goto EXPAND_FAILED;
5375           }
5376
5377         if (stat(CS sub, &st) < 0)
5378           {
5379           expand_string_message = string_sprintf("stat(%s) failed: %s",
5380             sub, strerror(errno));
5381           goto EXPAND_FAILED;
5382           }
5383         mode = st.st_mode;
5384         switch (mode & S_IFMT)
5385           {
5386           case S_IFIFO: smode[0] = 'p'; break;
5387           case S_IFCHR: smode[0] = 'c'; break;
5388           case S_IFDIR: smode[0] = 'd'; break;
5389           case S_IFBLK: smode[0] = 'b'; break;
5390           case S_IFREG: smode[0] = '-'; break;
5391           default: smode[0] = '?'; break;
5392           }
5393
5394         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
5395         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
5396         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
5397
5398         for (i = 0; i < 3; i++)
5399           {
5400           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
5401           mode >>= 3;
5402           }
5403
5404         smode[10] = 0;
5405         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
5406           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
5407           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
5408           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
5409           (long)st.st_gid, st.st_size, (long)st.st_atime,
5410           (long)st.st_mtime, (long)st.st_ctime);
5411         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
5412         continue;
5413         }
5414
5415       /* Unknown operator */
5416
5417       default:
5418       expand_string_message =
5419         string_sprintf("unknown expansion operator \"%s\"", name);
5420       goto EXPAND_FAILED;
5421       }
5422     }
5423
5424   /* Handle a plain name. If this is the first thing in the expansion, release
5425   the pre-allocated buffer. If the result data is known to be in a new buffer,
5426   newsize will be set to the size of that buffer, and we can just point at that
5427   store instead of copying. Many expansion strings contain just one reference,
5428   so this is a useful optimization, especially for humungous headers
5429   ($message_headers). */
5430
5431   if (*s++ == '}')
5432     {
5433     int len;
5434     int newsize = 0;
5435     if (ptr == 0)
5436       {
5437       store_reset(yield);
5438       yield = NULL;
5439       size = 0;
5440       }
5441     value = find_variable(name, FALSE, skipping, &newsize);
5442     if (value == NULL)
5443       {
5444       expand_string_message =
5445         string_sprintf("unknown variable in \"${%s}\"", name);
5446       check_variable_error_message(name);
5447       goto EXPAND_FAILED;
5448       }
5449     len = Ustrlen(value);
5450     if (yield == NULL && newsize != 0)
5451       {
5452       yield = value;
5453       size = newsize;
5454       ptr = len;
5455       }
5456     else yield = string_cat(yield, &size, &ptr, value, len);
5457     continue;
5458     }
5459
5460   /* Else there's something wrong */
5461
5462   expand_string_message =
5463     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
5464     "in a variable reference)", name);
5465   goto EXPAND_FAILED;
5466   }
5467
5468 /* If we hit the end of the string when ket_ends is set, there is a missing
5469 terminating brace. */
5470
5471 if (ket_ends && *s == 0)
5472   {
5473   expand_string_message = malformed_header?
5474     US"missing } at end of string - could be header name not terminated by colon"
5475     :
5476     US"missing } at end of string";
5477   goto EXPAND_FAILED;
5478   }
5479
5480 /* Expansion succeeded; yield may still be NULL here if nothing was actually
5481 added to the string. If so, set up an empty string. Add a terminating zero. If
5482 left != NULL, return a pointer to the terminator. */
5483
5484 if (yield == NULL) yield = store_get(1);
5485 yield[ptr] = 0;
5486 if (left != NULL) *left = s;
5487
5488 /* Any stacking store that was used above the final string is no longer needed.
5489 In many cases the final string will be the first one that was got and so there
5490 will be optimal store usage. */
5491
5492 store_reset(yield + ptr + 1);
5493 DEBUG(D_expand)
5494   {
5495   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
5496     yield);
5497   if (skipping) debug_printf("skipping: result is not used\n");
5498   }
5499 return yield;
5500
5501 /* This is the failure exit: easiest to program with a goto. We still need
5502 to update the pointer to the terminator, for cases of nested calls with "fail".
5503 */
5504
5505 EXPAND_FAILED_CURLY:
5506 expand_string_message = malformed_header?
5507   US"missing or misplaced { or } - could be header name not terminated by colon"
5508   :
5509   US"missing or misplaced { or }";
5510
5511 /* At one point, Exim reset the store to yield (if yield was not NULL), but
5512 that is a bad idea, because expand_string_message is in dynamic store. */
5513
5514 EXPAND_FAILED:
5515 if (left != NULL) *left = s;
5516 DEBUG(D_expand)
5517   {
5518   debug_printf("failed to expand: %s\n", string);
5519   debug_printf("   error message: %s\n", expand_string_message);
5520   if (expand_string_forcedfail) debug_printf("failure was forced\n");
5521   }
5522 return NULL;
5523 }
5524
5525
5526 /* This is the external function call. Do a quick check for any expansion
5527 metacharacters, and if there are none, just return the input string.
5528
5529 Argument: the string to be expanded
5530 Returns:  the expanded string, or NULL if expansion failed; if failure was
5531           due to a lookup deferring, search_find_defer will be TRUE
5532 */
5533
5534 uschar *
5535 expand_string(uschar *string)
5536 {
5537 search_find_defer = FALSE;
5538 malformed_header = FALSE;
5539 return (Ustrpbrk(string, "$\\") == NULL)? string :
5540   expand_string_internal(string, FALSE, NULL, FALSE);
5541 }
5542
5543
5544
5545 /*************************************************
5546 *              Expand and copy                   *
5547 *************************************************/
5548
5549 /* Now and again we want to expand a string and be sure that the result is in a
5550 new bit of store. This function does that.
5551
5552 Argument: the string to be expanded
5553 Returns:  the expanded string, always in a new bit of store, or NULL
5554 */
5555
5556 uschar *
5557 expand_string_copy(uschar *string)
5558 {
5559 uschar *yield = expand_string(string);
5560 if (yield == string) yield = string_copy(string);
5561 return yield;
5562 }
5563
5564
5565
5566 /*************************************************
5567 *        Expand and interpret as an integer      *
5568 *************************************************/
5569
5570 /* Expand a string, and convert the result into an integer.
5571
5572 Arguments:
5573   string  the string to be expanded
5574   isplus  TRUE if a non-negative number is expected
5575
5576 Returns:  the integer value, or
5577           -1 for an expansion error               ) in both cases, message in
5578           -2 for an integer interpretation error  ) expand_string_message
5579           expand_string_message is set NULL for an OK integer
5580 */
5581
5582 int
5583 expand_string_integer(uschar *string, BOOL isplus)
5584 {
5585 long int value;
5586 uschar *s = expand_string(string);
5587 uschar *msg = US"invalid integer \"%s\"";
5588 uschar *endptr;
5589
5590 /* If expansion failed, expand_string_message will be set. */
5591
5592 if (s == NULL) return -1;
5593
5594 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
5595 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
5596 systems, so we set it zero ourselves. */
5597
5598 errno = 0;
5599 expand_string_message = NULL;               /* Indicates no error */
5600 value = strtol(CS s, CSS &endptr, 10);
5601
5602 if (endptr == s)
5603   {
5604   msg = US"integer expected but \"%s\" found";
5605   }
5606 else if (value < 0 && isplus)
5607   {
5608   msg = US"non-negative integer expected but \"%s\" found";
5609   }
5610 else
5611   {
5612   /* Ensure we can cast this down to an int */
5613   if (value > INT_MAX  || value < INT_MIN) errno = ERANGE;
5614
5615   if (errno != ERANGE)
5616     {
5617     if (tolower(*endptr) == 'k')
5618       {
5619       if (value > INT_MAX/1024 || value < INT_MIN/1024) errno = ERANGE;
5620         else value *= 1024;
5621       endptr++;
5622       }
5623     else if (tolower(*endptr) == 'm')
5624       {
5625       if (value > INT_MAX/(1024*1024) || value < INT_MIN/(1024*1024))
5626         errno = ERANGE;
5627       else value *= 1024*1024;
5628       endptr++;
5629       }
5630     }
5631   if (errno == ERANGE)
5632     msg = US"absolute value of integer \"%s\" is too large (overflow)";
5633   else
5634     {
5635     while (isspace(*endptr)) endptr++;
5636     if (*endptr == 0) return (int)value;
5637     }
5638   }
5639
5640 expand_string_message = string_sprintf(CS msg, s);
5641 return -2;
5642 }
5643
5644
5645 /*************************************************
5646 **************************************************
5647 *             Stand-alone test program           *
5648 **************************************************
5649 *************************************************/
5650
5651 #ifdef STAND_ALONE
5652
5653
5654 BOOL
5655 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
5656 {
5657 int ovector[3*(EXPAND_MAXN+1)];
5658 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
5659   ovector, sizeof(ovector)/sizeof(int));
5660 BOOL yield = n >= 0;
5661 if (n == 0) n = EXPAND_MAXN + 1;
5662 if (yield)
5663   {
5664   int nn;
5665   expand_nmax = (setup < 0)? 0 : setup + 1;
5666   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
5667     {
5668     expand_nstring[expand_nmax] = subject + ovector[nn];
5669     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5670     }
5671   expand_nmax--;
5672   }
5673 return yield;
5674 }
5675
5676
5677 int main(int argc, uschar **argv)
5678 {
5679 int i;
5680 uschar buffer[1024];
5681
5682 debug_selector = D_v;
5683 debug_file = stderr;
5684 debug_fd = fileno(debug_file);
5685 big_buffer = malloc(big_buffer_size);
5686
5687 for (i = 1; i < argc; i++)
5688   {
5689   if (argv[i][0] == '+')
5690     {
5691     debug_trace_memory = 2;
5692     argv[i]++;
5693     }
5694   if (isdigit(argv[i][0]))
5695     debug_selector = Ustrtol(argv[i], NULL, 0);
5696   else
5697     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
5698         Ustrlen(argv[i]))
5699       {
5700       #ifdef LOOKUP_LDAP
5701       eldap_default_servers = argv[i];
5702       #endif
5703       #ifdef LOOKUP_MYSQL
5704       mysql_servers = argv[i];
5705       #endif
5706       #ifdef LOOKUP_PGSQL
5707       pgsql_servers = argv[i];
5708       #endif
5709       }
5710   #ifdef EXIM_PERL
5711   else opt_perl_startup = argv[i];
5712   #endif
5713   }
5714
5715 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
5716
5717 expand_nstring[1] = US"string 1....";
5718 expand_nlength[1] = 8;
5719 expand_nmax = 1;
5720
5721 #ifdef EXIM_PERL
5722 if (opt_perl_startup != NULL)
5723   {
5724   uschar *errstr;
5725   printf("Starting Perl interpreter\n");
5726   errstr = init_perl(opt_perl_startup);
5727   if (errstr != NULL)
5728     {
5729     printf("** error in perl_startup code: %s\n", errstr);
5730     return EXIT_FAILURE;
5731     }
5732   }
5733 #endif /* EXIM_PERL */
5734
5735 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
5736   {
5737   void *reset_point = store_get(0);
5738   uschar *yield = expand_string(buffer);
5739   if (yield != NULL)
5740     {
5741     printf("%s\n", yield);
5742     store_reset(reset_point);
5743     }
5744   else
5745     {
5746     if (search_find_defer) printf("search_find deferred\n");
5747     printf("Failed: %s\n", expand_string_message);
5748     if (expand_string_forcedfail) printf("Forced failure\n");
5749     printf("\n");
5750     }
5751   }
5752
5753 search_tidyup();
5754
5755 return 0;
5756 }
5757
5758 #endif
5759
5760 /* End of expand.c */