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[exim.git] / src / src / expand.c
1 /* $Cambridge: exim/src/src/expand.c,v 1.2 2004/10/19 13:40:39 ph10 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2004 */
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 #ifdef STAND_ALONE
17 #ifndef SUPPORT_CRYPTEQ
18 #define SUPPORT_CRYPTEQ
19 #endif
20 #endif
21
22 #ifdef SUPPORT_CRYPTEQ
23 #ifdef CRYPT_H
24 #include <crypt.h>
25 #endif
26 #ifndef HAVE_CRYPT16
27 extern char* crypt16(char*, char*);
28 #endif
29 #endif
30
31 #ifdef LOOKUP_LDAP
32 #include "lookups/ldap.h"
33 #endif
34
35
36
37 /* Recursively called function */
38
39 static uschar *expand_string_internal(uschar *, BOOL, uschar **, BOOL);
40
41
42
43 /*************************************************
44 * Local statics and tables *
45 *************************************************/
46
47 /* Table of item names, and corresponding switch numbers. The names must be in
48 alphabetical order. */
49
50 static uschar *item_table[] = {
51 US"extract",
52 US"hash",
53 US"hmac",
54 US"if",
55 US"length",
56 US"lookup",
57 US"nhash",
58 #ifdef EXIM_PERL
59 US"perl",
60 #endif
61 US"readfile",
62 US"readsocket",
63 US"run",
64 US"sg",
65 US"substr",
66 US"tr" };
67
68 enum {
69 EITEM_EXTRACT,
70 EITEM_HASH,
71 EITEM_HMAC,
72 EITEM_IF,
73 EITEM_LENGTH,
74 EITEM_LOOKUP,
75 EITEM_NHASH,
76 #ifdef EXIM_PERL
77 EITEM_PERL,
78 #endif
79 EITEM_READFILE,
80 EITEM_READSOCK,
81 EITEM_RUN,
82 EITEM_SG,
83 EITEM_SUBSTR,
84 EITEM_TR };
85
86 /* Tables of operator names, and corresponding switch numbers. The names must be
87 in alphabetical order. There are two tables, because underscore is used in some
88 cases to introduce arguments, whereas for other it is part of the name. This is
89 an historical mis-design. */
90
91 static uschar *op_table_underscore[] = {
92 US"from_utf8",
93 US"local_part",
94 US"quote_local_part",
95 US"time_interval"};
96
97 enum {
98 EOP_FROM_UTF8,
99 EOP_LOCAL_PART,
100 EOP_QUOTE_LOCAL_PART,
101 EOP_TIME_INTERVAL };
102
103 static uschar *op_table_main[] = {
104 US"address",
105 US"base62",
106 US"base62d",
107 US"domain",
108 US"escape",
109 US"eval",
110 US"eval10",
111 US"expand",
112 US"h",
113 US"hash",
114 US"hex2b64",
115 US"l",
116 US"lc",
117 US"length",
118 US"mask",
119 US"md5",
120 US"nh",
121 US"nhash",
122 US"quote",
123 US"rfc2047",
124 US"rxquote",
125 US"s",
126 US"sha1",
127 US"stat",
128 US"str2b64",
129 US"strlen",
130 US"substr",
131 US"uc" };
132
133 enum {
134 EOP_ADDRESS = sizeof(op_table_underscore)/sizeof(uschar *),
135 EOP_BASE62,
136 EOP_BASE62D,
137 EOP_DOMAIN,
138 EOP_ESCAPE,
139 EOP_EVAL,
140 EOP_EVAL10,
141 EOP_EXPAND,
142 EOP_H,
143 EOP_HASH,
144 EOP_HEX2B64,
145 EOP_L,
146 EOP_LC,
147 EOP_LENGTH,
148 EOP_MASK,
149 EOP_MD5,
150 EOP_NH,
151 EOP_NHASH,
152 EOP_QUOTE,
153 EOP_RFC2047,
154 EOP_RXQUOTE,
155 EOP_S,
156 EOP_SHA1,
157 EOP_STAT,
158 EOP_STR2B64,
159 EOP_STRLEN,
160 EOP_SUBSTR,
161 EOP_UC };
162
163
164 /* Table of condition names, and corresponding switch numbers. The names must
165 be in alphabetical order. */
166
167 static uschar *cond_table[] = {
168 US"<",
169 US"<=",
170 US"=",
171 US"==", /* Backward compatibility */
172 US">",
173 US">=",
174 US"and",
175 US"crypteq",
176 US"def",
177 US"eq",
178 US"eqi",
179 US"exists",
180 US"first_delivery",
181 US"ge",
182 US"gei",
183 US"gt",
184 US"gti",
185 US"isip",
186 US"isip4",
187 US"isip6",
188 US"ldapauth",
189 US"le",
190 US"lei",
191 US"lt",
192 US"lti",
193 US"match",
194 US"match_address",
195 US"match_domain",
196 US"match_local_part",
197 US"or",
198 US"pam",
199 US"pwcheck",
200 US"queue_running",
201 US"radius",
202 US"saslauthd"
203 };
204
205 enum {
206 ECOND_NUM_L,
207 ECOND_NUM_LE,
208 ECOND_NUM_E,
209 ECOND_NUM_EE,
210 ECOND_NUM_G,
211 ECOND_NUM_GE,
212 ECOND_AND,
213 ECOND_CRYPTEQ,
214 ECOND_DEF,
215 ECOND_STR_EQ,
216 ECOND_STR_EQI,
217 ECOND_EXISTS,
218 ECOND_FIRST_DELIVERY,
219 ECOND_STR_GE,
220 ECOND_STR_GEI,
221 ECOND_STR_GT,
222 ECOND_STR_GTI,
223 ECOND_ISIP,
224 ECOND_ISIP4,
225 ECOND_ISIP6,
226 ECOND_LDAPAUTH,
227 ECOND_STR_LE,
228 ECOND_STR_LEI,
229 ECOND_STR_LT,
230 ECOND_STR_LTI,
231 ECOND_MATCH,
232 ECOND_MATCH_ADDRESS,
233 ECOND_MATCH_DOMAIN,
234 ECOND_MATCH_LOCAL_PART,
235 ECOND_OR,
236 ECOND_PAM,
237 ECOND_PWCHECK,
238 ECOND_QUEUE_RUNNING,
239 ECOND_RADIUS,
240 ECOND_SASLAUTHD
241 };
242
243
244 /* Type for main variable table */
245
246 typedef struct {
247 char *name;
248 int type;
249 void *value;
250 } var_entry;
251
252 /* Type for entries pointing to address/length pairs. Not currently
253 in use. */
254
255 typedef struct {
256 uschar **address;
257 int *length;
258 } alblock;
259
260 /* Types of table entry */
261
262 enum {
263 vtype_int, /* value is address of int */
264 vtype_filter_int, /* ditto, but recognized only when filtering */
265 vtype_ino, /* value is address of ino_t (not always an int) */
266 vtype_uid, /* value is address of uid_t (not always an int) */
267 vtype_gid, /* value is address of gid_t (not always an int) */
268 vtype_stringptr, /* value is address of pointer to string */
269 vtype_msgbody, /* as stringptr, but read when first required */
270 vtype_msgbody_end, /* ditto, the end of the message */
271 vtype_msgheaders, /* the message's headers */
272 vtype_localpart, /* extract local part from string */
273 vtype_domain, /* extract domain from string */
274 vtype_recipients, /* extract recipients from recipients list */
275 /* (enabled only during system filtering */
276 vtype_todbsdin, /* value not used; generate BSD inbox tod */
277 vtype_tode, /* value not used; generate tod in epoch format */
278 vtype_todf, /* value not used; generate full tod */
279 vtype_todl, /* value not used; generate log tod */
280 vtype_todlf, /* value not used; generate log file datestamp tod */
281 vtype_todzone, /* value not used; generate time zone only */
282 vtype_todzulu, /* value not used; generate zulu tod */
283 vtype_reply, /* value not used; get reply from headers */
284 vtype_pid, /* value not used; result is pid */
285 vtype_host_lookup, /* value not used; get host name */
286 vtype_load_avg /* value not used; result is int from os_getloadavg */
287 };
288
289 /* This table must be kept in alphabetical order. */
290
291 static var_entry var_table[] = {
292 { "acl_c0", vtype_stringptr, &acl_var[0] },
293 { "acl_c1", vtype_stringptr, &acl_var[1] },
294 { "acl_c2", vtype_stringptr, &acl_var[2] },
295 { "acl_c3", vtype_stringptr, &acl_var[3] },
296 { "acl_c4", vtype_stringptr, &acl_var[4] },
297 { "acl_c5", vtype_stringptr, &acl_var[5] },
298 { "acl_c6", vtype_stringptr, &acl_var[6] },
299 { "acl_c7", vtype_stringptr, &acl_var[7] },
300 { "acl_c8", vtype_stringptr, &acl_var[8] },
301 { "acl_c9", vtype_stringptr, &acl_var[9] },
302 { "acl_m0", vtype_stringptr, &acl_var[10] },
303 { "acl_m1", vtype_stringptr, &acl_var[11] },
304 { "acl_m2", vtype_stringptr, &acl_var[12] },
305 { "acl_m3", vtype_stringptr, &acl_var[13] },
306 { "acl_m4", vtype_stringptr, &acl_var[14] },
307 { "acl_m5", vtype_stringptr, &acl_var[15] },
308 { "acl_m6", vtype_stringptr, &acl_var[16] },
309 { "acl_m7", vtype_stringptr, &acl_var[17] },
310 { "acl_m8", vtype_stringptr, &acl_var[18] },
311 { "acl_m9", vtype_stringptr, &acl_var[19] },
312 { "acl_verify_message", vtype_stringptr, &acl_verify_message },
313 { "address_data", vtype_stringptr, &deliver_address_data },
314 { "address_file", vtype_stringptr, &address_file },
315 { "address_pipe", vtype_stringptr, &address_pipe },
316 { "authenticated_id", vtype_stringptr, &authenticated_id },
317 { "authenticated_sender",vtype_stringptr, &authenticated_sender },
318 { "authentication_failed",vtype_int, &authentication_failed },
319 { "body_linecount", vtype_int, &body_linecount },
320 { "body_zerocount", vtype_int, &body_zerocount },
321 { "bounce_recipient", vtype_stringptr, &bounce_recipient },
322 { "bounce_return_size_limit", vtype_int, &bounce_return_size_limit },
323 { "caller_gid", vtype_gid, &real_gid },
324 { "caller_uid", vtype_uid, &real_uid },
325 { "compile_date", vtype_stringptr, &version_date },
326 { "compile_number", vtype_stringptr, &version_cnumber },
327 { "dnslist_domain", vtype_stringptr, &dnslist_domain },
328 { "dnslist_text", vtype_stringptr, &dnslist_text },
329 { "dnslist_value", vtype_stringptr, &dnslist_value },
330 { "domain", vtype_stringptr, &deliver_domain },
331 { "domain_data", vtype_stringptr, &deliver_domain_data },
332 { "exim_gid", vtype_gid, &exim_gid },
333 { "exim_path", vtype_stringptr, &exim_path },
334 { "exim_uid", vtype_uid, &exim_uid },
335 { "home", vtype_stringptr, &deliver_home },
336 { "host", vtype_stringptr, &deliver_host },
337 { "host_address", vtype_stringptr, &deliver_host_address },
338 { "host_data", vtype_stringptr, &host_data },
339 { "host_lookup_failed", vtype_int, &host_lookup_failed },
340 { "inode", vtype_ino, &deliver_inode },
341 { "interface_address", vtype_stringptr, &interface_address },
342 { "interface_port", vtype_int, &interface_port },
343 #ifdef LOOKUP_LDAP
344 { "ldap_dn", vtype_stringptr, &eldap_dn },
345 #endif
346 { "load_average", vtype_load_avg, NULL },
347 { "local_part", vtype_stringptr, &deliver_localpart },
348 { "local_part_data", vtype_stringptr, &deliver_localpart_data },
349 { "local_part_prefix", vtype_stringptr, &deliver_localpart_prefix },
350 { "local_part_suffix", vtype_stringptr, &deliver_localpart_suffix },
351 { "local_scan_data", vtype_stringptr, &local_scan_data },
352 { "local_user_gid", vtype_gid, &local_user_gid },
353 { "local_user_uid", vtype_uid, &local_user_uid },
354 { "localhost_number", vtype_int, &host_number },
355 { "mailstore_basename", vtype_stringptr, &mailstore_basename },
356 { "message_age", vtype_int, &message_age },
357 { "message_body", vtype_msgbody, &message_body },
358 { "message_body_end", vtype_msgbody_end, &message_body_end },
359 { "message_body_size", vtype_int, &message_body_size },
360 { "message_headers", vtype_msgheaders, NULL },
361 { "message_id", vtype_stringptr, &message_id },
362 { "message_size", vtype_int, &message_size },
363 { "n0", vtype_filter_int, &filter_n[0] },
364 { "n1", vtype_filter_int, &filter_n[1] },
365 { "n2", vtype_filter_int, &filter_n[2] },
366 { "n3", vtype_filter_int, &filter_n[3] },
367 { "n4", vtype_filter_int, &filter_n[4] },
368 { "n5", vtype_filter_int, &filter_n[5] },
369 { "n6", vtype_filter_int, &filter_n[6] },
370 { "n7", vtype_filter_int, &filter_n[7] },
371 { "n8", vtype_filter_int, &filter_n[8] },
372 { "n9", vtype_filter_int, &filter_n[9] },
373 { "original_domain", vtype_stringptr, &deliver_domain_orig },
374 { "original_local_part", vtype_stringptr, &deliver_localpart_orig },
375 { "originator_gid", vtype_gid, &originator_gid },
376 { "originator_uid", vtype_uid, &originator_uid },
377 { "parent_domain", vtype_stringptr, &deliver_domain_parent },
378 { "parent_local_part", vtype_stringptr, &deliver_localpart_parent },
379 { "pid", vtype_pid, NULL },
380 { "primary_hostname", vtype_stringptr, &primary_hostname },
381 { "qualify_domain", vtype_stringptr, &qualify_domain_sender },
382 { "qualify_recipient", vtype_stringptr, &qualify_domain_recipient },
383 { "rcpt_count", vtype_int, &rcpt_count },
384 { "rcpt_defer_count", vtype_int, &rcpt_defer_count },
385 { "rcpt_fail_count", vtype_int, &rcpt_fail_count },
386 { "received_count", vtype_int, &received_count },
387 { "received_for", vtype_stringptr, &received_for },
388 { "received_protocol", vtype_stringptr, &received_protocol },
389 { "recipient_data", vtype_stringptr, &recipient_data },
390 { "recipients", vtype_recipients, NULL },
391 { "recipients_count", vtype_int, &recipients_count },
392 { "reply_address", vtype_reply, NULL },
393 { "return_path", vtype_stringptr, &return_path },
394 { "return_size_limit", vtype_int, &bounce_return_size_limit },
395 { "runrc", vtype_int, &runrc },
396 { "self_hostname", vtype_stringptr, &self_hostname },
397 { "sender_address", vtype_stringptr, &sender_address },
398 { "sender_address_data", vtype_stringptr, &sender_address_data },
399 { "sender_address_domain", vtype_domain, &sender_address },
400 { "sender_address_local_part", vtype_localpart, &sender_address },
401 { "sender_data", vtype_stringptr, &sender_data },
402 { "sender_fullhost", vtype_stringptr, &sender_fullhost },
403 { "sender_helo_name", vtype_stringptr, &sender_helo_name },
404 { "sender_host_address", vtype_stringptr, &sender_host_address },
405 { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
406 { "sender_host_name", vtype_host_lookup, NULL },
407 { "sender_host_port", vtype_int, &sender_host_port },
408 { "sender_ident", vtype_stringptr, &sender_ident },
409 { "sender_rcvhost", vtype_stringptr, &sender_rcvhost },
410 { "smtp_command_argument", vtype_stringptr, &smtp_command_argument },
411 { "sn0", vtype_filter_int, &filter_sn[0] },
412 { "sn1", vtype_filter_int, &filter_sn[1] },
413 { "sn2", vtype_filter_int, &filter_sn[2] },
414 { "sn3", vtype_filter_int, &filter_sn[3] },
415 { "sn4", vtype_filter_int, &filter_sn[4] },
416 { "sn5", vtype_filter_int, &filter_sn[5] },
417 { "sn6", vtype_filter_int, &filter_sn[6] },
418 { "sn7", vtype_filter_int, &filter_sn[7] },
419 { "sn8", vtype_filter_int, &filter_sn[8] },
420 { "sn9", vtype_filter_int, &filter_sn[9] },
421 { "spool_directory", vtype_stringptr, &spool_directory },
422 { "thisaddress", vtype_stringptr, &filter_thisaddress },
423 { "tls_certificate_verified", vtype_int, &tls_certificate_verified },
424 { "tls_cipher", vtype_stringptr, &tls_cipher },
425 { "tls_peerdn", vtype_stringptr, &tls_peerdn },
426 { "tod_bsdinbox", vtype_todbsdin, NULL },
427 { "tod_epoch", vtype_tode, NULL },
428 { "tod_full", vtype_todf, NULL },
429 { "tod_log", vtype_todl, NULL },
430 { "tod_logfile", vtype_todlf, NULL },
431 { "tod_zone", vtype_todzone, NULL },
432 { "tod_zulu", vtype_todzulu, NULL },
433 { "value", vtype_stringptr, &lookup_value },
434 { "version_number", vtype_stringptr, &version_string },
435 { "warn_message_delay", vtype_stringptr, &warnmsg_delay },
436 { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
437 { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
438 { "warnmsg_delay", vtype_stringptr, &warnmsg_delay },
439 { "warnmsg_recipient", vtype_stringptr, &warnmsg_recipients },
440 { "warnmsg_recipients", vtype_stringptr, &warnmsg_recipients }
441 };
442
443 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
444 static uschar var_buffer[256];
445 static BOOL malformed_header;
446
447 /* For textual hashes */
448
449 static char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
450 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
451 "0123456789";
452
453 enum { HMAC_MD5, HMAC_SHA1 };
454
455 /* For numeric hashes */
456
457 static unsigned int prime[] = {
458 2, 3, 5, 7, 11, 13, 17, 19, 23, 29,
459 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
460 73, 79, 83, 89, 97, 101, 103, 107, 109, 113};
461
462 /* For printing modes in symbolic form */
463
464 static uschar *mtable_normal[] =
465 { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
466
467 static uschar *mtable_setid[] =
468 { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
469
470 static uschar *mtable_sticky[] =
471 { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
472
473
474
475 /*************************************************
476 * Tables for UTF-8 support *
477 *************************************************/
478
479 /* Table of the number of extra characters, indexed by the first character
480 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
481 0x3d. */
482
483 static uschar utf8_table1[] = {
484 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
485 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
486 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
487 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
488
489 /* These are the masks for the data bits in the first byte of a character,
490 indexed by the number of additional bytes. */
491
492 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
493
494 /* Get the next UTF-8 character, advancing the pointer. */
495
496 #define GETUTF8INC(c, ptr) \
497 c = *ptr++; \
498 if ((c & 0xc0) == 0xc0) \
499 { \
500 int a = utf8_table1[c & 0x3f]; /* Number of additional bytes */ \
501 int s = 6*a; \
502 c = (c & utf8_table2[a]) << s; \
503 while (a-- > 0) \
504 { \
505 s -= 6; \
506 c |= (*ptr++ & 0x3f) << s; \
507 } \
508 }
509
510
511 /*************************************************
512 * Binary chop search on a table *
513 *************************************************/
514
515 /* This is used for matching expansion items and operators.
516
517 Arguments:
518 name the name that is being sought
519 table the table to search
520 table_size the number of items in the table
521
522 Returns: the offset in the table, or -1
523 */
524
525 static int
526 chop_match(uschar *name, uschar **table, int table_size)
527 {
528 uschar **bot = table;
529 uschar **top = table + table_size;
530
531 while (top > bot)
532 {
533 uschar **mid = bot + (top - bot)/2;
534 int c = Ustrcmp(name, *mid);
535 if (c == 0) return mid - table;
536 if (c > 0) bot = mid + 1; else top = mid;
537 }
538
539 return -1;
540 }
541
542
543
544 /*************************************************
545 * Check a condition string *
546 *************************************************/
547
548 /* This function is called to expand a string, and test the result for a "true"
549 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
550 forced fail or lookup defer. All store used by the function can be released on
551 exit.
552
553 Arguments:
554 condition the condition string
555 m1 text to be incorporated in panic error
556 m2 ditto
557
558 Returns: TRUE if condition is met, FALSE if not
559 */
560
561 BOOL
562 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
563 {
564 int rc;
565 void *reset_point = store_get(0);
566 uschar *ss = expand_string(condition);
567 if (ss == NULL)
568 {
569 if (!expand_string_forcedfail && !search_find_defer)
570 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
571 "for %s %s: %s", condition, m1, m2, expand_string_message);
572 return FALSE;
573 }
574 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
575 strcmpic(ss, US"false") != 0;
576 store_reset(reset_point);
577 return rc;
578 }
579
580
581
582 /*************************************************
583 * Pick out a name from a string *
584 *************************************************/
585
586 /* If the name is too long, it is silently truncated.
587
588 Arguments:
589 name points to a buffer into which to put the name
590 max is the length of the buffer
591 s points to the first alphabetic character of the name
592 extras chars other than alphanumerics to permit
593
594 Returns: pointer to the first character after the name
595
596 Note: The test for *s != 0 in the while loop is necessary because
597 Ustrchr() yields non-NULL if the character is zero (which is not something
598 I expected). */
599
600 static uschar *
601 read_name(uschar *name, int max, uschar *s, uschar *extras)
602 {
603 int ptr = 0;
604 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
605 {
606 if (ptr < max-1) name[ptr++] = *s;
607 s++;
608 }
609 name[ptr] = 0;
610 return s;
611 }
612
613
614
615 /*************************************************
616 * Pick out the rest of a header name *
617 *************************************************/
618
619 /* A variable name starting $header_ (or just $h_ for those who like
620 abbreviations) might not be the complete header name because headers can
621 contain any printing characters in their names, except ':'. This function is
622 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
623 on the end, if the name was terminated by white space.
624
625 Arguments:
626 name points to a buffer in which the name read so far exists
627 max is the length of the buffer
628 s points to the first character after the name so far, i.e. the
629 first non-alphameric character after $header_xxxxx
630
631 Returns: a pointer to the first character after the header name
632 */
633
634 static uschar *
635 read_header_name(uschar *name, int max, uschar *s)
636 {
637 int prelen = Ustrchr(name, '_') - name + 1;
638 int ptr = Ustrlen(name) - prelen;
639 if (ptr > 0) memmove(name, name+prelen, ptr);
640 while (mac_isgraph(*s) && *s != ':')
641 {
642 if (ptr < max-1) name[ptr++] = *s;
643 s++;
644 }
645 if (*s == ':') s++;
646 name[ptr++] = ':';
647 name[ptr] = 0;
648 return s;
649 }
650
651
652
653 /*************************************************
654 * Pick out a number from a string *
655 *************************************************/
656
657 /* Arguments:
658 n points to an integer into which to put the number
659 s points to the first digit of the number
660
661 Returns: a pointer to the character after the last digit
662 */
663
664 static uschar *
665 read_number(int *n, uschar *s)
666 {
667 *n = 0;
668 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
669 return s;
670 }
671
672
673
674 /*************************************************
675 * Extract keyed subfield from a string *
676 *************************************************/
677
678 /* The yield is in dynamic store; NULL means that the key was not found.
679
680 Arguments:
681 key points to the name of the key
682 s points to the string from which to extract the subfield
683
684 Returns: NULL if the subfield was not found, or
685 a pointer to the subfield's data
686 */
687
688 static uschar *
689 expand_getkeyed(uschar *key, uschar *s)
690 {
691 int length = Ustrlen(key);
692 while (isspace(*s)) s++;
693
694 /* Loop to search for the key */
695
696 while (*s != 0)
697 {
698 int dkeylength;
699 uschar *data;
700 uschar *dkey = s;
701
702 while (*s != 0 && *s != '=' && !isspace(*s)) s++;
703 dkeylength = s - dkey;
704 while (isspace(*s)) s++;
705 if (*s == '=') while (isspace((*(++s))));
706
707 data = string_dequote(&s);
708 if (length == dkeylength && strncmpic(key, dkey, length) == 0)
709 return data;
710
711 while (isspace(*s)) s++;
712 }
713
714 return NULL;
715 }
716
717
718
719
720 /*************************************************
721 * Extract numbered subfield from string *
722 *************************************************/
723
724 /* Extracts a numbered field from a string that is divided by tokens - for
725 example a line from /etc/passwd is divided by colon characters. First field is
726 numbered one. Negative arguments count from the right. Zero returns the whole
727 string. Returns NULL if there are insufficient tokens in the string
728
729 ***WARNING***
730 Modifies final argument - this is a dynamically generated string, so that's OK.
731
732 Arguments:
733 field number of field to be extracted,
734 first field = 1, whole string = 0, last field = -1
735 separators characters that are used to break string into tokens
736 s points to the string from which to extract the subfield
737
738 Returns: NULL if the field was not found,
739 a pointer to the field's data inside s (modified to add 0)
740 */
741
742 static uschar *
743 expand_gettokened (int field, uschar *separators, uschar *s)
744 {
745 int sep = 1;
746 int count;
747 uschar *ss = s;
748 uschar *fieldtext = NULL;
749
750 if (field == 0) return s;
751
752 /* Break the line up into fields in place; for field > 0 we stop when we have
753 done the number of fields we want. For field < 0 we continue till the end of
754 the string, counting the number of fields. */
755
756 count = (field > 0)? field : INT_MAX;
757
758 while (count-- > 0)
759 {
760 size_t len;
761
762 /* Previous field was the last one in the string. For a positive field
763 number, this means there are not enough fields. For a negative field number,
764 check that there are enough, and scan back to find the one that is wanted. */
765
766 if (sep == 0)
767 {
768 if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
769 if ((-field) == (INT_MAX - count - 1)) return s;
770 while (field++ < 0)
771 {
772 ss--;
773 while (ss[-1] != 0) ss--;
774 }
775 fieldtext = ss;
776 break;
777 }
778
779 /* Previous field was not last in the string; save its start and put a
780 zero at its end. */
781
782 fieldtext = ss;
783 len = Ustrcspn(ss, separators);
784 sep = ss[len];
785 ss[len] = 0;
786 ss += len + 1;
787 }
788
789 return fieldtext;
790 }
791
792
793
794 /*************************************************
795 * Extract a substring from a string *
796 *************************************************/
797
798 /* Perform the ${substr or ${length expansion operations.
799
800 Arguments:
801 subject the input string
802 value1 the offset from the start of the input string to the start of
803 the output string; if negative, count from the right.
804 value2 the length of the output string, or negative (-1) for unset
805 if value1 is positive, unset means "all after"
806 if value1 is negative, unset means "all before"
807 len set to the length of the returned string
808
809 Returns: pointer to the output string, or NULL if there is an error
810 */
811
812 static uschar *
813 extract_substr(uschar *subject, int value1, int value2, int *len)
814 {
815 int sublen = Ustrlen(subject);
816
817 if (value1 < 0) /* count from right */
818 {
819 value1 += sublen;
820
821 /* If the position is before the start, skip to the start, and adjust the
822 length. If the length ends up negative, the substring is null because nothing
823 can precede. This falls out naturally when the length is unset, meaning "all
824 to the left". */
825
826 if (value1 < 0)
827 {
828 value2 += value1;
829 if (value2 < 0) value2 = 0;
830 value1 = 0;
831 }
832
833 /* Otherwise an unset length => characters before value1 */
834
835 else if (value2 < 0)
836 {
837 value2 = value1;
838 value1 = 0;
839 }
840 }
841
842 /* For a non-negative offset, if the starting position is past the end of the
843 string, the result will be the null string. Otherwise, an unset length means
844 "rest"; just set it to the maximum - it will be cut down below if necessary. */
845
846 else
847 {
848 if (value1 > sublen)
849 {
850 value1 = sublen;
851 value2 = 0;
852 }
853 else if (value2 < 0) value2 = sublen;
854 }
855
856 /* Cut the length down to the maximum possible for the offset value, and get
857 the required characters. */
858
859 if (value1 + value2 > sublen) value2 = sublen - value1;
860 *len = value2;
861 return subject + value1;
862 }
863
864
865
866
867 /*************************************************
868 * Old-style hash of a string *
869 *************************************************/
870
871 /* Perform the ${hash expansion operation.
872
873 Arguments:
874 subject the input string (an expanded substring)
875 value1 the length of the output string; if greater or equal to the
876 length of the input string, the input string is returned
877 value2 the number of hash characters to use, or 26 if negative
878 len set to the length of the returned string
879
880 Returns: pointer to the output string, or NULL if there is an error
881 */
882
883 static uschar *
884 compute_hash(uschar *subject, int value1, int value2, int *len)
885 {
886 int sublen = Ustrlen(subject);
887
888 if (value2 < 0) value2 = 26;
889 else if (value2 > Ustrlen(hashcodes))
890 {
891 expand_string_message =
892 string_sprintf("hash count \"%d\" too big", value2);
893 return NULL;
894 }
895
896 /* Calculate the hash text. We know it is shorter than the original string, so
897 can safely place it in subject[] (we know that subject is always itself an
898 expanded substring). */
899
900 if (value1 < sublen)
901 {
902 int c;
903 int i = 0;
904 int j = value1;
905 while ((c = (subject[j])) != 0)
906 {
907 int shift = (c + j++) & 7;
908 subject[i] ^= (c << shift) | (c >> (8-shift));
909 if (++i >= value1) i = 0;
910 }
911 for (i = 0; i < value1; i++)
912 subject[i] = hashcodes[(subject[i]) % value2];
913 }
914 else value1 = sublen;
915
916 *len = value1;
917 return subject;
918 }
919
920
921
922
923 /*************************************************
924 * Numeric hash of a string *
925 *************************************************/
926
927 /* Perform the ${nhash expansion operation. The first characters of the
928 string are treated as most important, and get the highest prime numbers.
929
930 Arguments:
931 subject the input string
932 value1 the maximum value of the first part of the result
933 value2 the maximum value of the second part of the result,
934 or negative to produce only a one-part result
935 len set to the length of the returned string
936
937 Returns: pointer to the output string, or NULL if there is an error.
938 */
939
940 static uschar *
941 compute_nhash (uschar *subject, int value1, int value2, int *len)
942 {
943 uschar *s = subject;
944 int i = 0;
945 unsigned long int total = 0; /* no overflow */
946
947 while (*s != 0)
948 {
949 if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
950 total += prime[i--] * (unsigned int)(*s++);
951 }
952
953 /* If value2 is unset, just compute one number */
954
955 if (value2 < 0)
956 {
957 s = string_sprintf("%d", total % value1);
958 }
959
960 /* Otherwise do a div/mod hash */
961
962 else
963 {
964 total = total % (value1 * value2);
965 s = string_sprintf("%d/%d", total/value2, total % value2);
966 }
967
968 *len = Ustrlen(s);
969 return s;
970 }
971
972
973
974
975
976 /*************************************************
977 * Find the value of a header or headers *
978 *************************************************/
979
980 /* Multiple instances of the same header get concatenated, and this function
981 can also return a concatenation of all the header lines. When concatenating
982 specific headers that contain lists of addresses, a comma is inserted between
983 them. Otherwise we use a straight concatenation. Because some messages can have
984 pathologically large number of lines, there is a limit on the length that is
985 returned. Also, to avoid massive store use which would result from using
986 string_cat() as it copies and extends strings, we do a preliminary pass to find
987 out exactly how much store will be needed. On "normal" messages this will be
988 pretty trivial.
989
990 Arguments:
991 name the name of the header, without the leading $header_ or $h_,
992 or NULL if a concatenation of all headers is required
993 exists_only TRUE if called from a def: test; don't need to build a string;
994 just return a string that is not "" and not "0" if the header
995 exists
996 newsize return the size of memory block that was obtained; may be NULL
997 if exists_only is TRUE
998 want_raw TRUE if called for $rh_ or $rheader_ variables; no processing,
999 other than concatenating, will be done on the header
1000 charset name of charset to translate MIME words to; used only if
1001 want_raw is false; if NULL, no translation is done (this is
1002 used for $bh_ and $bheader_)
1003
1004 Returns: NULL if the header does not exist, else a pointer to a new
1005 store block
1006 */
1007
1008 static uschar *
1009 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1010 uschar *charset)
1011 {
1012 BOOL found = name == NULL;
1013 int comma = 0;
1014 int len = found? 0 : Ustrlen(name);
1015 int i;
1016 uschar *yield = NULL;
1017 uschar *ptr = NULL;
1018
1019 /* Loop for two passes - saves code repetition */
1020
1021 for (i = 0; i < 2; i++)
1022 {
1023 int size = 0;
1024 header_line *h;
1025
1026 for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1027 {
1028 if (h->type != htype_old && h->text != NULL) /* NULL => Received: placeholder */
1029 {
1030 if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1031 {
1032 int ilen;
1033 uschar *t;
1034
1035 if (exists_only) return US"1"; /* don't need actual string */
1036 found = TRUE;
1037 t = h->text + len; /* text to insert */
1038 if (!want_raw) /* unless wanted raw, */
1039 while (isspace(*t)) t++; /* remove leading white space */
1040 ilen = h->slen - (t - h->text); /* length to insert */
1041
1042 /* Set comma = 1 if handling a single header and it's one of those
1043 that contains an address list, except when asked for raw headers. Only
1044 need to do this once. */
1045
1046 if (!want_raw && name != NULL && comma == 0 &&
1047 Ustrchr("BCFRST", h->type) != NULL)
1048 comma = 1;
1049
1050 /* First pass - compute total store needed; second pass - compute
1051 total store used, including this header. */
1052
1053 size += ilen + comma;
1054
1055 /* Second pass - concatentate the data, up to a maximum. Note that
1056 the loop stops when size hits the limit. */
1057
1058 if (i != 0)
1059 {
1060 if (size > header_insert_maxlen)
1061 {
1062 ilen -= size - header_insert_maxlen;
1063 comma = 0;
1064 }
1065 Ustrncpy(ptr, t, ilen);
1066 ptr += ilen;
1067 if (comma != 0 && ilen > 0)
1068 {
1069 ptr[-1] = ',';
1070 *ptr++ = '\n';
1071 }
1072 }
1073 }
1074 }
1075 }
1076
1077 /* At end of first pass, truncate size if necessary, and get the buffer
1078 to hold the data, returning the buffer size. */
1079
1080 if (i == 0)
1081 {
1082 if (!found) return NULL;
1083 if (size > header_insert_maxlen) size = header_insert_maxlen;
1084 *newsize = size + 1;
1085 ptr = yield = store_get(*newsize);
1086 }
1087 }
1088
1089 /* Remove a redundant added comma if present */
1090
1091 if (comma != 0 && ptr > yield) ptr -= 2;
1092
1093 /* That's all we do for raw header expansion. */
1094
1095 if (want_raw)
1096 {
1097 *ptr = 0;
1098 }
1099
1100 /* Otherwise, we remove trailing whitespace, including newlines. Then we do RFC
1101 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1102 function can return an error with decoded data if the charset translation
1103 fails. If decoding fails, it returns NULL. */
1104
1105 else
1106 {
1107 uschar *decoded, *error;
1108 while (ptr > yield && isspace(ptr[-1])) ptr--;
1109 *ptr = 0;
1110 decoded = rfc2047_decode2(yield, TRUE, charset, '?', NULL, newsize, &error);
1111 if (error != NULL)
1112 {
1113 DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1114 " input was: %s\n", error, yield);
1115 }
1116 if (decoded != NULL) yield = decoded;
1117 }
1118
1119 return yield;
1120 }
1121
1122
1123
1124
1125 /*************************************************
1126 * Find value of a variable *
1127 *************************************************/
1128
1129 /* The table of variables is kept in alphabetic order, so we can search it
1130 using a binary chop. The "choplen" variable is nothing to do with the binary
1131 chop.
1132
1133 Arguments:
1134 name the name of the variable being sought
1135 exists_only TRUE if this is a def: test; passed on to find_header()
1136 skipping TRUE => skip any processing evaluation; this is not the same as
1137 exists_only because def: may test for values that are first
1138 evaluated here
1139 newsize pointer to an int which is initially zero; if the answer is in
1140 a new memory buffer, *newsize is set to its size
1141
1142 Returns: NULL if the variable does not exist, or
1143 a pointer to the variable's contents, or
1144 something non-NULL if exists_only is TRUE
1145 */
1146
1147 static uschar *
1148 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1149 {
1150 int first = 0;
1151 int last = var_table_size;
1152
1153 while (last > first)
1154 {
1155 uschar *s, *domain;
1156 uschar **ss;
1157 int middle = (first + last)/2;
1158 int c = Ustrcmp(name, var_table[middle].name);
1159
1160 if (c > 0) { first = middle + 1; continue; }
1161 if (c < 0) { last = middle; continue; }
1162
1163 /* Found an existing variable. If in skipping state, the value isn't needed,
1164 and we want to avoid processing (such as looking up up the host name). */
1165
1166 if (skipping) return US"";
1167
1168 switch (var_table[middle].type)
1169 {
1170 case vtype_filter_int:
1171 if (!filter_running) return NULL;
1172 /* Fall through */
1173
1174 case vtype_int:
1175 sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1176 return var_buffer;
1177
1178 case vtype_ino:
1179 sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1180 return var_buffer;
1181
1182 case vtype_gid:
1183 sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1184 return var_buffer;
1185
1186 case vtype_uid:
1187 sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1188 return var_buffer;
1189
1190 case vtype_stringptr: /* Pointer to string */
1191 s = *((uschar **)(var_table[middle].value));
1192 return (s == NULL)? US"" : s;
1193
1194 case vtype_pid:
1195 sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1196 return var_buffer;
1197
1198 case vtype_load_avg:
1199 sprintf(CS var_buffer, "%d", os_getloadavg()); /* load_average */
1200 return var_buffer;
1201
1202 case vtype_host_lookup: /* Lookup if not done so */
1203 if (sender_host_name == NULL && sender_host_address != NULL &&
1204 !host_lookup_failed && host_name_lookup() == OK)
1205 host_build_sender_fullhost();
1206 return (sender_host_name == NULL)? US"" : sender_host_name;
1207
1208 case vtype_localpart: /* Get local part from address */
1209 s = *((uschar **)(var_table[middle].value));
1210 if (s == NULL) return US"";
1211 domain = Ustrrchr(s, '@');
1212 if (domain == NULL) return s;
1213 if (domain - s > sizeof(var_buffer) - 1)
1214 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than %d in "
1215 "string expansion", sizeof(var_buffer));
1216 Ustrncpy(var_buffer, s, domain - s);
1217 var_buffer[domain - s] = 0;
1218 return var_buffer;
1219
1220 case vtype_domain: /* Get domain from address */
1221 s = *((uschar **)(var_table[middle].value));
1222 if (s == NULL) return US"";
1223 domain = Ustrrchr(s, '@');
1224 return (domain == NULL)? US"" : domain + 1;
1225
1226 case vtype_msgheaders:
1227 return find_header(NULL, exists_only, newsize, FALSE, NULL);
1228
1229 case vtype_msgbody: /* Pointer to msgbody string */
1230 case vtype_msgbody_end: /* Ditto, the end of the msg */
1231 ss = (uschar **)(var_table[middle].value);
1232 if (*ss == NULL && deliver_datafile >= 0) /* Read body when needed */
1233 {
1234 uschar *body;
1235 int start_offset = SPOOL_DATA_START_OFFSET;
1236 int len = message_body_visible;
1237 if (len > message_size) len = message_size;
1238 *ss = body = store_malloc(len+1);
1239 body[0] = 0;
1240 if (var_table[middle].type == vtype_msgbody_end)
1241 {
1242 struct stat statbuf;
1243 if (fstat(deliver_datafile, &statbuf) == 0)
1244 {
1245 start_offset = statbuf.st_size - len;
1246 if (start_offset < SPOOL_DATA_START_OFFSET)
1247 start_offset = SPOOL_DATA_START_OFFSET;
1248 }
1249 }
1250 lseek(deliver_datafile, start_offset, SEEK_SET);
1251 len = read(deliver_datafile, body, len);
1252 if (len > 0)
1253 {
1254 body[len] = 0;
1255 while (len > 0)
1256 {
1257 if (body[--len] == '\n' || body[len] == 0) body[len] = ' ';
1258 }
1259 }
1260 }
1261 return (*ss == NULL)? US"" : *ss;
1262
1263 case vtype_todbsdin: /* BSD inbox time of day */
1264 return tod_stamp(tod_bsdin);
1265
1266 case vtype_tode: /* Unix epoch time of day */
1267 return tod_stamp(tod_epoch);
1268
1269 case vtype_todf: /* Full time of day */
1270 return tod_stamp(tod_full);
1271
1272 case vtype_todl: /* Log format time of day */
1273 return tod_stamp(tod_log_bare); /* (without timezone) */
1274
1275 case vtype_todzone: /* Time zone offset only */
1276 return tod_stamp(tod_zone);
1277
1278 case vtype_todzulu: /* Zulu time */
1279 return tod_stamp(tod_zulu);
1280
1281 case vtype_todlf: /* Log file datestamp tod */
1282 return tod_stamp(tod_log_datestamp);
1283
1284 case vtype_reply: /* Get reply address */
1285 s = find_header(US"reply-to:", exists_only, newsize, FALSE,
1286 headers_charset);
1287 if (s == NULL || *s == 0)
1288 s = find_header(US"from:", exists_only, newsize, FALSE, headers_charset);
1289 return (s == NULL)? US"" : s;
1290
1291 /* A recipients list is available only during system message filtering,
1292 during ACL processing after DATA, and while expanding pipe commands
1293 generated from a system filter, but not elsewhere. */
1294
1295 case vtype_recipients:
1296 if (!enable_dollar_recipients) return NULL; else
1297 {
1298 int size = 128;
1299 int ptr = 0;
1300 int i;
1301 s = store_get(size);
1302 for (i = 0; i < recipients_count; i++)
1303 {
1304 if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1305 s = string_cat(s, &size, &ptr, recipients_list[i].address,
1306 Ustrlen(recipients_list[i].address));
1307 }
1308 s[ptr] = 0; /* string_cat() leaves room */
1309 }
1310 return s;
1311 }
1312 }
1313
1314 return NULL; /* Unknown variable name */
1315 }
1316
1317
1318
1319
1320 /*************************************************
1321 * Read and expand substrings *
1322 *************************************************/
1323
1324 /* This function is called to read and expand argument substrings for various
1325 expansion items. Some have a minimum requirement that is less than the maximum;
1326 in these cases, the first non-present one is set to NULL.
1327
1328 Arguments:
1329 sub points to vector of pointers to set
1330 n maximum number of substrings
1331 m minimum required
1332 sptr points to current string pointer
1333 skipping the skipping flag
1334 check_end if TRUE, check for final '}'
1335 name name of item, for error message
1336
1337 Returns: 0 OK; string pointer updated
1338 1 curly bracketing error (too few arguments)
1339 2 too many arguments (only if check_end is set); message set
1340 3 other error (expansion failure)
1341 */
1342
1343 static int
1344 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1345 BOOL check_end, uschar *name)
1346 {
1347 int i;
1348 uschar *s = *sptr;
1349
1350 while (isspace(*s)) s++;
1351 for (i = 0; i < n; i++)
1352 {
1353 if (*s != '{')
1354 {
1355 if (i < m) return 1;
1356 sub[i] = NULL;
1357 break;
1358 }
1359 sub[i] = expand_string_internal(s+1, TRUE, &s, skipping);
1360 if (sub[i] == NULL) return 3;
1361 if (*s++ != '}') return 1;
1362 while (isspace(*s)) s++;
1363 }
1364 if (check_end && *s++ != '}')
1365 {
1366 if (s[-1] == '{')
1367 {
1368 expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1369 "(max is %d)", name, n);
1370 return 2;
1371 }
1372 return 1;
1373 }
1374
1375 *sptr = s;
1376 return 0;
1377 }
1378
1379
1380
1381
1382 /*************************************************
1383 * Read and evaluate a condition *
1384 *************************************************/
1385
1386 /*
1387 Arguments:
1388 s points to the start of the condition text
1389 yield points to a BOOL to hold the result of the condition test;
1390 if NULL, we are just reading through a condition that is
1391 part of an "or" combination to check syntax, or in a state
1392 where the answer isn't required
1393
1394 Returns: a pointer to the first character after the condition, or
1395 NULL after an error
1396 */
1397
1398 static uschar *
1399 eval_condition(uschar *s, BOOL *yield)
1400 {
1401 BOOL testfor = TRUE;
1402 BOOL tempcond, combined_cond;
1403 BOOL *subcondptr;
1404 int i, rc, cond_type, roffset;
1405 int num[2];
1406 struct stat statbuf;
1407 uschar name[256];
1408 uschar *sub[4];
1409
1410 const pcre *re;
1411 const uschar *rerror;
1412
1413 for (;;)
1414 {
1415 while (isspace(*s)) s++;
1416 if (*s == '!') { testfor = !testfor; s++; } else break;
1417 }
1418
1419 /* Numeric comparisons are symbolic */
1420
1421 if (*s == '=' || *s == '>' || *s == '<')
1422 {
1423 int p = 0;
1424 name[p++] = *s++;
1425 if (*s == '=')
1426 {
1427 name[p++] = '=';
1428 s++;
1429 }
1430 name[p] = 0;
1431 }
1432
1433 /* All other conditions are named */
1434
1435 else s = read_name(name, 256, s, US"_");
1436
1437 /* If we haven't read a name, it means some non-alpha character is first. */
1438
1439 if (name[0] == 0)
1440 {
1441 expand_string_message = string_sprintf("condition name expected, "
1442 "but found \"%.16s\"", s);
1443 return NULL;
1444 }
1445
1446 /* Find which condition we are dealing with, and switch on it */
1447
1448 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1449 switch(cond_type)
1450 {
1451 /* def: tests for a non-zero or non-NULL variable, or for an existing
1452 header */
1453
1454 case ECOND_DEF:
1455 if (*s != ':')
1456 {
1457 expand_string_message = US"\":\" expected after \"def\"";
1458 return NULL;
1459 }
1460
1461 s = read_name(name, 256, s+1, US"_");
1462
1463 /* Test for a header's existence */
1464
1465 if (Ustrncmp(name, "h_", 2) == 0 ||
1466 Ustrncmp(name, "rh_", 3) == 0 ||
1467 Ustrncmp(name, "bh_", 3) == 0 ||
1468 Ustrncmp(name, "header_", 7) == 0 ||
1469 Ustrncmp(name, "rheader_", 8) == 0 ||
1470 Ustrncmp(name, "bheader_", 8) == 0)
1471 {
1472 s = read_header_name(name, 256, s);
1473 if (yield != NULL) *yield =
1474 (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1475 }
1476
1477 /* Test for a variable's having a non-empty value. If yield == NULL we
1478 are in a skipping state, and don't care about the answer. */
1479
1480 else
1481 {
1482 uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1483 if (value == NULL)
1484 {
1485 expand_string_message = (name[0] == 0)?
1486 string_sprintf("variable name omitted after \"def:\"") :
1487 string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1488 return NULL;
1489 }
1490 if (yield != NULL)
1491 *yield = (value[0] != 0 && Ustrcmp(value, "0") != 0) == testfor;
1492 }
1493
1494 return s;
1495
1496
1497 /* first_delivery tests for first delivery attempt */
1498
1499 case ECOND_FIRST_DELIVERY:
1500 if (yield != NULL) *yield = deliver_firsttime == testfor;
1501 return s;
1502
1503
1504 /* queue_running tests for any process started by a queue runner */
1505
1506 case ECOND_QUEUE_RUNNING:
1507 if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
1508 return s;
1509
1510
1511 /* exists: tests for file existence
1512 isip: tests for any IP address
1513 isip4: tests for an IPv4 address
1514 isip6: tests for an IPv6 address
1515 pam: does PAM authentication
1516 radius: does RADIUS authentication
1517 ldapauth: does LDAP authentication
1518 pwcheck: does Cyrus SASL pwcheck authentication
1519 */
1520
1521 case ECOND_EXISTS:
1522 case ECOND_ISIP:
1523 case ECOND_ISIP4:
1524 case ECOND_ISIP6:
1525 case ECOND_PAM:
1526 case ECOND_RADIUS:
1527 case ECOND_LDAPAUTH:
1528 case ECOND_PWCHECK:
1529
1530 while (isspace(*s)) s++;
1531 if (*s != '{') goto COND_FAILED_CURLY_START;
1532
1533 sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1534 if (sub[0] == NULL) return NULL;
1535 if (*s++ != '}') goto COND_FAILED_CURLY_END;
1536
1537 if (yield == NULL) return s; /* No need to run the test if skipping */
1538
1539 switch(cond_type)
1540 {
1541 case ECOND_EXISTS:
1542 if ((expand_forbid & RDO_EXISTS) != 0)
1543 {
1544 expand_string_message = US"File existence tests are not permitted";
1545 return NULL;
1546 }
1547 *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
1548 break;
1549
1550 case ECOND_ISIP:
1551 case ECOND_ISIP4:
1552 case ECOND_ISIP6:
1553 rc = string_is_ip_address(sub[0], NULL);
1554 *yield = ((cond_type == ECOND_ISIP)? (rc > 0) :
1555 (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
1556 break;
1557
1558 /* Various authentication tests - all optionally compiled */
1559
1560 case ECOND_PAM:
1561 #ifdef SUPPORT_PAM
1562 rc = auth_call_pam(sub[0], &expand_string_message);
1563 goto END_AUTH;
1564 #else
1565 goto COND_FAILED_NOT_COMPILED;
1566 #endif /* SUPPORT_PAM */
1567
1568 case ECOND_RADIUS:
1569 #ifdef RADIUS_CONFIG_FILE
1570 rc = auth_call_radius(sub[0], &expand_string_message);
1571 goto END_AUTH;
1572 #else
1573 goto COND_FAILED_NOT_COMPILED;
1574 #endif /* RADIUS_CONFIG_FILE */
1575
1576 case ECOND_LDAPAUTH:
1577 #ifdef LOOKUP_LDAP
1578 {
1579 /* Just to keep the interface the same */
1580 BOOL do_cache;
1581 int old_pool = store_pool;
1582 store_pool = POOL_SEARCH;
1583 rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
1584 &expand_string_message, &do_cache);
1585 store_pool = old_pool;
1586 }
1587 goto END_AUTH;
1588 #else
1589 goto COND_FAILED_NOT_COMPILED;
1590 #endif /* LOOKUP_LDAP */
1591
1592 case ECOND_PWCHECK:
1593 #ifdef CYRUS_PWCHECK_SOCKET
1594 rc = auth_call_pwcheck(sub[0], &expand_string_message);
1595 goto END_AUTH;
1596 #else
1597 goto COND_FAILED_NOT_COMPILED;
1598 #endif /* CYRUS_PWCHECK_SOCKET */
1599
1600 #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
1601 defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
1602 END_AUTH:
1603 if (rc == ERROR || rc == DEFER) return NULL;
1604 *yield = (rc == OK) == testfor;
1605 #endif
1606 }
1607 return s;
1608
1609
1610 /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
1611
1612 ${if saslauthd {{username}{password}{service}{realm}} {yes}[no}}
1613
1614 However, the last two are optional. That is why the whole set is enclosed
1615 in their own set or braces. */
1616
1617 case ECOND_SASLAUTHD:
1618 #ifndef CYRUS_SASLAUTHD_SOCKET
1619 goto COND_FAILED_NOT_COMPILED;
1620 #else
1621 while (isspace(*s)) s++;
1622 if (*s++ != '{') goto COND_FAILED_CURLY_START;
1623 switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
1624 {
1625 case 1: expand_string_message = US"too few arguments or bracketing "
1626 "error for saslauthd";
1627 case 2:
1628 case 3: return NULL;
1629 }
1630 if (sub[2] == NULL) sub[3] = NULL; /* realm if no service */
1631 if (yield != NULL)
1632 {
1633 int rc;
1634 rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
1635 &expand_string_message);
1636 if (rc == ERROR || rc == DEFER) return NULL;
1637 *yield = (rc == OK) == testfor;
1638 }
1639 return s;
1640 #endif /* CYRUS_SASLAUTHD_SOCKET */
1641
1642
1643 /* symbolic operators for numeric and string comparison, and a number of
1644 other operators, all requiring two arguments.
1645
1646 match: does a regular expression match and sets up the numerical
1647 variables if it succeeds
1648 match_address: matches in an address list
1649 match_domain: matches in a domain list
1650 match_local_part: matches in a local part list
1651 crypteq: encrypts plaintext and compares against an encrypted text,
1652 using crypt(), crypt16(), MD5 or SHA-1
1653 */
1654
1655 case ECOND_MATCH:
1656 case ECOND_MATCH_ADDRESS:
1657 case ECOND_MATCH_DOMAIN:
1658 case ECOND_MATCH_LOCAL_PART:
1659 case ECOND_CRYPTEQ:
1660
1661 case ECOND_NUM_L: /* Numerical comparisons */
1662 case ECOND_NUM_LE:
1663 case ECOND_NUM_E:
1664 case ECOND_NUM_EE:
1665 case ECOND_NUM_G:
1666 case ECOND_NUM_GE:
1667
1668 case ECOND_STR_LT: /* String comparisons */
1669 case ECOND_STR_LTI:
1670 case ECOND_STR_LE:
1671 case ECOND_STR_LEI:
1672 case ECOND_STR_EQ:
1673 case ECOND_STR_EQI:
1674 case ECOND_STR_GT:
1675 case ECOND_STR_GTI:
1676 case ECOND_STR_GE:
1677 case ECOND_STR_GEI:
1678
1679 for (i = 0; i < 2; i++)
1680 {
1681 while (isspace(*s)) s++;
1682 if (*s != '{')
1683 {
1684 if (i == 0) goto COND_FAILED_CURLY_START;
1685 expand_string_message = string_sprintf("missing 2nd string in {} "
1686 "after \"%s\"", name);
1687 return NULL;
1688 }
1689 sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1690 if (sub[i] == NULL) return NULL;
1691 if (*s++ != '}') goto COND_FAILED_CURLY_END;
1692
1693 /* Convert to numerical if required; we know that the names of all the
1694 conditions that compare numbers do not start with a letter. This just saves
1695 checking for them individually. */
1696
1697 if (!isalpha(name[0]))
1698 {
1699 uschar *endptr;
1700 num[i] = (int)Ustrtol((const uschar *)sub[i], &endptr, 10);
1701 if (tolower(*endptr) == 'k')
1702 {
1703 num[i] *= 1024;
1704 endptr++;
1705 }
1706 else if (tolower(*endptr) == 'm')
1707 {
1708 num[i] *= 1024*1024;
1709 endptr++;
1710 }
1711 while (isspace(*endptr)) endptr++;
1712 if (*endptr != 0)
1713 {
1714 expand_string_message = string_sprintf("\"%s\" is not a number",
1715 sub[i]);
1716 return NULL;
1717 }
1718 }
1719 }
1720
1721 /* Result not required */
1722
1723 if (yield == NULL) return s;
1724
1725 /* Do an appropriate comparison */
1726
1727 switch(cond_type)
1728 {
1729 case ECOND_NUM_E:
1730 case ECOND_NUM_EE:
1731 *yield = (num[0] == num[1]) == testfor;
1732 break;
1733
1734 case ECOND_NUM_G:
1735 *yield = (num[0] > num[1]) == testfor;
1736 break;
1737
1738 case ECOND_NUM_GE:
1739 *yield = (num[0] >= num[1]) == testfor;
1740 break;
1741
1742 case ECOND_NUM_L:
1743 *yield = (num[0] < num[1]) == testfor;
1744 break;
1745
1746 case ECOND_NUM_LE:
1747 *yield = (num[0] <= num[1]) == testfor;
1748 break;
1749
1750 case ECOND_STR_LT:
1751 *yield = (Ustrcmp(sub[0], sub[1]) < 0) == testfor;
1752 break;
1753
1754 case ECOND_STR_LTI:
1755 *yield = (strcmpic(sub[0], sub[1]) < 0) == testfor;
1756 break;
1757
1758 case ECOND_STR_LE:
1759 *yield = (Ustrcmp(sub[0], sub[1]) <= 0) == testfor;
1760 break;
1761
1762 case ECOND_STR_LEI:
1763 *yield = (strcmpic(sub[0], sub[1]) <= 0) == testfor;
1764 break;
1765
1766 case ECOND_STR_EQ:
1767 *yield = (Ustrcmp(sub[0], sub[1]) == 0) == testfor;
1768 break;
1769
1770 case ECOND_STR_EQI:
1771 *yield = (strcmpic(sub[0], sub[1]) == 0) == testfor;
1772 break;
1773
1774 case ECOND_STR_GT:
1775 *yield = (Ustrcmp(sub[0], sub[1]) > 0) == testfor;
1776 break;
1777
1778 case ECOND_STR_GTI:
1779 *yield = (strcmpic(sub[0], sub[1]) > 0) == testfor;
1780 break;
1781
1782 case ECOND_STR_GE:
1783 *yield = (Ustrcmp(sub[0], sub[1]) >= 0) == testfor;
1784 break;
1785
1786 case ECOND_STR_GEI:
1787 *yield = (strcmpic(sub[0], sub[1]) >= 0) == testfor;
1788 break;
1789
1790 case ECOND_MATCH: /* Regular expression match */
1791 re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
1792 NULL);
1793 if (re == NULL)
1794 {
1795 expand_string_message = string_sprintf("regular expression error in "
1796 "\"%s\": %s at offset %d", sub[1], rerror, roffset);
1797 return NULL;
1798 }
1799 *yield = regex_match_and_setup(re, sub[0], 0, -1) == testfor;
1800 break;
1801
1802 case ECOND_MATCH_ADDRESS: /* Match in an address list */
1803 rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
1804 goto MATCHED_SOMETHING;
1805
1806 case ECOND_MATCH_DOMAIN: /* Match in a domain list */
1807 rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
1808 MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
1809 goto MATCHED_SOMETHING;
1810
1811 case ECOND_MATCH_LOCAL_PART:
1812 rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
1813 MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
1814 /* Fall through */
1815
1816 MATCHED_SOMETHING:
1817 switch(rc)
1818 {
1819 case OK:
1820 *yield = testfor;
1821 break;
1822
1823 case FAIL:
1824 *yield = !testfor;
1825 break;
1826
1827 case DEFER:
1828 expand_string_message = string_sprintf("unable to complete match "
1829 "against \"%s\": %s", sub[1], search_error_message);
1830 return NULL;
1831 }
1832
1833 break;
1834
1835 /* Various "encrypted" comparisons. If the second string starts with
1836 "{" then an encryption type is given. Default to crypt() or crypt16()
1837 (build-time choice). */
1838
1839 case ECOND_CRYPTEQ:
1840 #ifndef SUPPORT_CRYPTEQ
1841 goto COND_FAILED_NOT_COMPILED;
1842 #else
1843 if (strncmpic(sub[1], US"{md5}", 5) == 0)
1844 {
1845 int sublen = Ustrlen(sub[1]+5);
1846 md5 base;
1847 uschar digest[16];
1848
1849 md5_start(&base);
1850 md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
1851
1852 /* If the length that we are comparing against is 24, the MD5 digest
1853 is expressed as a base64 string. This is the way LDAP does it. However,
1854 some other software uses a straightforward hex representation. We assume
1855 this if the length is 32. Other lengths fail. */
1856
1857 if (sublen == 24)
1858 {
1859 uschar *coded = auth_b64encode((uschar *)digest, 16);
1860 DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
1861 " subject=%s\n crypted=%s\n", coded, sub[1]+5);
1862 *yield = (Ustrcmp(coded, sub[1]+5) == 0) == testfor;
1863 }
1864 else if (sublen == 32)
1865 {
1866 int i;
1867 uschar coded[36];
1868 for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
1869 coded[32] = 0;
1870 DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
1871 " subject=%s\n crypted=%s\n", coded, sub[1]+5);
1872 *yield = (strcmpic(coded, sub[1]+5) == 0) == testfor;
1873 }
1874 else
1875 {
1876 DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
1877 "fail\n crypted=%s\n", sub[1]+5);
1878 *yield = !testfor;
1879 }
1880 }
1881
1882 else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
1883 {
1884 int sublen = Ustrlen(sub[1]+6);
1885 sha1 base;
1886 uschar digest[20];
1887
1888 sha1_start(&base);
1889 sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
1890
1891 /* If the length that we are comparing against is 28, assume the SHA1
1892 digest is expressed as a base64 string. If the length is 40, assume a
1893 straightforward hex representation. Other lengths fail. */
1894
1895 if (sublen == 28)
1896 {
1897 uschar *coded = auth_b64encode((uschar *)digest, 20);
1898 DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
1899 " subject=%s\n crypted=%s\n", coded, sub[1]+6);
1900 *yield = (Ustrcmp(coded, sub[1]+6) == 0) == testfor;
1901 }
1902 else if (sublen == 40)
1903 {
1904 int i;
1905 uschar coded[44];
1906 for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
1907 coded[40] = 0;
1908 DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
1909 " subject=%s\n crypted=%s\n", coded, sub[1]+6);
1910 *yield = (strcmpic(coded, sub[1]+6) == 0) == testfor;
1911 }
1912 else
1913 {
1914 DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
1915 "fail\n crypted=%s\n", sub[1]+6);
1916 *yield = !testfor;
1917 }
1918 }
1919
1920 else /* {crypt} or {crypt16} and non-{ at start */
1921 {
1922 int which = 0;
1923 uschar *coded;
1924
1925 if (strncmpic(sub[1], US"{crypt}", 7) == 0)
1926 {
1927 sub[1] += 7;
1928 which = 1;
1929 }
1930 else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
1931 {
1932 sub[1] += 9;
1933 which = 2;
1934 }
1935 else if (sub[1][0] == '{')
1936 {
1937 expand_string_message = string_sprintf("unknown encryption mechanism "
1938 "in \"%s\"", sub[1]);
1939 return NULL;
1940 }
1941
1942 switch(which)
1943 {
1944 case 0: coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
1945 case 1: coded = US crypt(CS sub[0], CS sub[1]); break;
1946 default: coded = US crypt16(CS sub[0], CS sub[1]); break;
1947 }
1948
1949 #define STR(s) # s
1950 #define XSTR(s) STR(s)
1951 DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
1952 " subject=%s\n crypted=%s\n",
1953 (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
1954 coded, sub[1]);
1955 #undef STR
1956 #undef XSTR
1957
1958 /* If the encrypted string contains fewer than two characters (for the
1959 salt), force failure. Otherwise we get false positives: with an empty
1960 string the yield of crypt() is an empty string! */
1961
1962 *yield = (Ustrlen(sub[1]) < 2)? !testfor :
1963 (Ustrcmp(coded, sub[1]) == 0) == testfor;
1964 }
1965 break;
1966 #endif /* SUPPORT_CRYPTEQ */
1967 } /* Switch for comparison conditions */
1968
1969 return s; /* End of comparison conditions */
1970
1971
1972 /* and/or: computes logical and/or of several conditions */
1973
1974 case ECOND_AND:
1975 case ECOND_OR:
1976 subcondptr = (yield == NULL)? NULL : &tempcond;
1977 combined_cond = (cond_type == ECOND_AND);
1978
1979 while (isspace(*s)) s++;
1980 if (*s++ != '{') goto COND_FAILED_CURLY_START;
1981
1982 for (;;)
1983 {
1984 while (isspace(*s)) s++;
1985 if (*s == '}') break;
1986 if (*s != '{')
1987 {
1988 expand_string_message = string_sprintf("each subcondition "
1989 "inside an \"%s{...}\" condition must be in its own {}", name);
1990 return NULL;
1991 }
1992
1993 s = eval_condition(s+1, subcondptr);
1994 if (s == NULL)
1995 {
1996 expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
1997 expand_string_message, name);
1998 return NULL;
1999 }
2000 while (isspace(*s)) s++;
2001
2002 if (*s++ != '}')
2003 {
2004 expand_string_message = string_sprintf("missing } at end of condition "
2005 "inside \"%s\" group", name);
2006 return NULL;
2007 }
2008
2009 if (yield != NULL)
2010 {
2011 if (cond_type == ECOND_AND)
2012 {
2013 combined_cond &= tempcond;
2014 if (!combined_cond) subcondptr = NULL; /* once false, don't */
2015 } /* evaluate any more */
2016 else
2017 {
2018 combined_cond |= tempcond;
2019 if (combined_cond) subcondptr = NULL; /* once true, don't */
2020 } /* evaluate any more */
2021 }
2022 }
2023
2024 if (yield != NULL) *yield = (combined_cond == testfor);
2025 return ++s;
2026
2027
2028 /* Unknown condition */
2029
2030 default:
2031 expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2032 return NULL;
2033 } /* End switch on condition type */
2034
2035 /* Missing braces at start and end of data */
2036
2037 COND_FAILED_CURLY_START:
2038 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2039 return NULL;
2040
2041 COND_FAILED_CURLY_END:
2042 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2043 name);
2044 return NULL;
2045
2046 /* A condition requires code that is not compiled */
2047
2048 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2049 !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2050 !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2051 COND_FAILED_NOT_COMPILED:
2052 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2053 name);
2054 return NULL;
2055 #endif
2056 }
2057
2058
2059
2060
2061 /*************************************************
2062 * Save numerical variables *
2063 *************************************************/
2064
2065 /* This function is called from items such as "if" that want to preserve and
2066 restore the numbered variables.
2067
2068 Arguments:
2069 save_expand_string points to an array of pointers to set
2070 save_expand_nlength points to an array of ints for the lengths
2071
2072 Returns: the value of expand max to save
2073 */
2074
2075 static int
2076 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2077 {
2078 int i;
2079 for (i = 0; i <= expand_nmax; i++)
2080 {
2081 save_expand_nstring[i] = expand_nstring[i];
2082 save_expand_nlength[i] = expand_nlength[i];
2083 }
2084 return expand_nmax;
2085 }
2086
2087
2088
2089 /*************************************************
2090 * Restore numerical variables *
2091 *************************************************/
2092
2093 /* This function restored saved values of numerical strings.
2094
2095 Arguments:
2096 save_expand_nmax the number of strings to restore
2097 save_expand_string points to an array of pointers
2098 save_expand_nlength points to an array of ints
2099
2100 Returns: nothing
2101 */
2102
2103 static void
2104 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2105 int *save_expand_nlength)
2106 {
2107 int i;
2108 expand_nmax = save_expand_nmax;
2109 for (i = 0; i <= expand_nmax; i++)
2110 {
2111 expand_nstring[i] = save_expand_nstring[i];
2112 expand_nlength[i] = save_expand_nlength[i];
2113 }
2114 }
2115
2116
2117
2118
2119
2120 /*************************************************
2121 * Handle yes/no substrings *
2122 *************************************************/
2123
2124 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2125 alternative substrings that depend on whether or not the condition was true,
2126 or the lookup or extraction succeeded. The substrings always have to be
2127 expanded, to check their syntax, but "skipping" is set when the result is not
2128 needed - this avoids unnecessary nested lookups.
2129
2130 Arguments:
2131 skipping TRUE if we were skipping when this item was reached
2132 yes TRUE if the first string is to be used, else use the second
2133 save_lookup a value to put back into lookup_value before the 2nd expansion
2134 sptr points to the input string pointer
2135 yieldptr points to the output string pointer
2136 sizeptr points to the output string size
2137 ptrptr points to the output string pointer
2138 type "lookup" or "if" or "extract" or "run", for error message
2139
2140 Returns: 0 OK; lookup_value has been reset to save_lookup
2141 1 expansion failed
2142 2 expansion failed because of bracketing error
2143 */
2144
2145 static int
2146 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2147 uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2148 {
2149 int rc = 0;
2150 uschar *s = *sptr; /* Local value */
2151 uschar *sub1, *sub2;
2152
2153 /* If there are no following strings, we substitute the contents of $value for
2154 lookups and for extractions in the success case. In the fail case, nothing is
2155 substituted. In the case of "if", lack of following strings is an error. */
2156
2157 while (isspace(*s)) s++;
2158 if (*s == '}')
2159 {
2160 if (type[0] == 'i') goto FAILED_CURLY;
2161 if (yes && lookup_value != NULL)
2162 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2163 Ustrlen(lookup_value));
2164 lookup_value = save_lookup;
2165 s++;
2166 goto RETURN;
2167 }
2168
2169 /* Expand the first substring. Forced failures are noticed only if we actually
2170 want this string. Set skipping in the call in the fail case (this will always
2171 be the case if we were already skipping). */
2172
2173 sub1 = expand_string_internal(s+1, TRUE, &s, !yes);
2174 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2175 expand_string_forcedfail = FALSE;
2176 if (*s++ != '}') goto FAILED_CURLY;
2177
2178 /* If we want the first string, add it to the output */
2179
2180 if (yes)
2181 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2182
2183 /* If this is called from a lookup or an extract, we want to restore $value to
2184 what it was at the start of the item, so that it has this value during the
2185 second string expansion. For the call from "if" to this function, save_lookup
2186 is set to lookup_value, so that this statement does nothing. */
2187
2188 lookup_value = save_lookup;
2189
2190 /* There now follows either another substring, or "fail", or nothing. This
2191 time, forced failures are noticed only if we want the second string. We must
2192 set skipping in the nested call if we don't want this string, or if we were
2193 already skipping. */
2194
2195 while (isspace(*s)) s++;
2196 if (*s == '{')
2197 {
2198 sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping);
2199 if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2200 expand_string_forcedfail = FALSE;
2201 if (*s++ != '}') goto FAILED_CURLY;
2202
2203 /* If we want the second string, add it to the output */
2204
2205 if (!yes)
2206 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2207 }
2208
2209 /* If there is no second string, but the word "fail" is present when the use of
2210 the second string is wanted, set a flag indicating it was a forced failure
2211 rather than a syntactic error. Swallow the terminating } in case this is nested
2212 inside another lookup or if or extract. */
2213
2214 else if (*s != '}')
2215 {
2216 uschar name[256];
2217 s = read_name(name, sizeof(name), s, US"_");
2218 if (Ustrcmp(name, "fail") == 0)
2219 {
2220 if (!yes && !skipping)
2221 {
2222 while (isspace(*s)) s++;
2223 if (*s++ != '}') goto FAILED_CURLY;
2224 expand_string_message =
2225 string_sprintf("\"%s\" failed and \"fail\" requested", type);
2226 expand_string_forcedfail = TRUE;
2227 goto FAILED;
2228 }
2229 }
2230 else
2231 {
2232 expand_string_message =
2233 string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
2234 goto FAILED;
2235 }
2236 }
2237
2238 /* All we have to do now is to check on the final closing brace. */
2239
2240 while (isspace(*s)) s++;
2241 if (*s++ == '}') goto RETURN;
2242
2243 /* Get here if there is a bracketing failure */
2244
2245 FAILED_CURLY:
2246 rc++;
2247
2248 /* Get here for other failures */
2249
2250 FAILED:
2251 rc++;
2252
2253 /* Update the input pointer value before returning */
2254
2255 RETURN:
2256 *sptr = s;
2257 return rc;
2258 }
2259
2260
2261
2262
2263
2264
2265 /*************************************************
2266 * Handle MD5 or SHA-1 computation for HMAC *
2267 *************************************************/
2268
2269 /* These are some wrapping functions that enable the HMAC code to be a bit
2270 cleaner. A good compiler will spot the tail recursion.
2271
2272 Arguments:
2273 type HMAC_MD5 or HMAC_SHA1
2274 remaining are as for the cryptographic hash functions
2275
2276 Returns: nothing
2277 */
2278
2279 static void
2280 chash_start(int type, void *base)
2281 {
2282 if (type == HMAC_MD5)
2283 md5_start((md5 *)base);
2284 else
2285 sha1_start((sha1 *)base);
2286 }
2287
2288 static void
2289 chash_mid(int type, void *base, uschar *string)
2290 {
2291 if (type == HMAC_MD5)
2292 md5_mid((md5 *)base, string);
2293 else
2294 sha1_mid((sha1 *)base, string);
2295 }
2296
2297 static void
2298 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
2299 {
2300 if (type == HMAC_MD5)
2301 md5_end((md5 *)base, string, length, digest);
2302 else
2303 sha1_end((sha1 *)base, string, length, digest);
2304 }
2305
2306
2307
2308
2309
2310 /*************************************************
2311 * Join a file onto the output string *
2312 *************************************************/
2313
2314 /* This is used for readfile and after a run expansion. It joins the contents
2315 of a file onto the output string, globally replacing newlines with a given
2316 string (optionally). The file is closed at the end.
2317
2318 Arguments:
2319 f the FILE
2320 yield pointer to the expandable string
2321 sizep pointer to the current size
2322 ptrp pointer to the current position
2323 eol newline replacement string, or NULL
2324
2325 Returns: new value of string pointer
2326 */
2327
2328 static uschar *
2329 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
2330 {
2331 int eollen;
2332 uschar buffer[1024];
2333
2334 eollen = (eol == NULL)? 0 : Ustrlen(eol);
2335
2336 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
2337 {
2338 int len = Ustrlen(buffer);
2339 if (eol != NULL && buffer[len-1] == '\n') len--;
2340 yield = string_cat(yield, sizep, ptrp, buffer, len);
2341 if (buffer[len] != 0)
2342 yield = string_cat(yield, sizep, ptrp, eol, eollen);
2343 }
2344
2345 if (yield != NULL) yield[*ptrp] = 0;
2346
2347 return yield;
2348 }
2349
2350
2351
2352
2353 /*************************************************
2354 * Evaluate numeric expression *
2355 *************************************************/
2356
2357 /* This is a set of mutually recursive functions that evaluate a simple
2358 arithmetic expression involving only + - * / and parentheses. The only one that
2359 is called from elsewhere is eval_expr, whose interface is:
2360
2361 Arguments:
2362 sptr pointer to the pointer to the string - gets updated
2363 decimal TRUE if numbers are to be assumed decimal
2364 error pointer to where to put an error message - must be NULL on input
2365 endket TRUE if ')' must terminate - FALSE for external call
2366
2367
2368 Returns: on success: the value of the expression, with *error still NULL
2369 on failure: an undefined value, with *error = a message
2370 */
2371
2372 static int eval_sumterm(uschar **, BOOL, uschar **);
2373
2374 static int
2375 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
2376 {
2377 uschar *s = *sptr;
2378 int x = eval_sumterm(&s, decimal, error);
2379 if (*error == NULL)
2380 {
2381 while (*s == '+' || *s == '-')
2382 {
2383 int op = *s++;
2384 int y = eval_sumterm(&s, decimal, error);
2385 if (*error != NULL) break;
2386 if (op == '+') x += y; else x -= y;
2387 }
2388 if (*error == NULL)
2389 {
2390 if (endket)
2391 {
2392 if (*s != ')')
2393 *error = US"expecting closing parenthesis";
2394 else
2395 while (isspace(*(++s)));
2396 }
2397 else if (*s != 0) *error = US"expecting + or -";
2398 }
2399 }
2400
2401 *sptr = s;
2402 return x;
2403 }
2404
2405 static int
2406 eval_term(uschar **sptr, BOOL decimal, uschar **error)
2407 {
2408 register int c;
2409 int n;
2410 uschar *s = *sptr;
2411 while (isspace(*s)) s++;
2412 c = *s;
2413 if (isdigit(c) || ((c == '-' || c == '+') && isdigit(s[1])))
2414 {
2415 int count;
2416 (void)sscanf(CS s, (decimal? "%d%n" : "%i%n"), &n, &count);
2417 s += count;
2418 if (tolower(*s) == 'k') { n *= 1024; s++; }
2419 else if (tolower(*s) == 'm') { n *= 1024*1024; s++; }
2420 while (isspace (*s)) s++;
2421 }
2422 else if (c == '(')
2423 {
2424 s++;
2425 n = eval_expr(&s, decimal, error, 1);
2426 }
2427 else
2428 {
2429 *error = US"expecting number or opening parenthesis";
2430 n = 0;
2431 }
2432 *sptr = s;
2433 return n;
2434 }
2435
2436 static int eval_sumterm(uschar **sptr, BOOL decimal, uschar **error)
2437 {
2438 uschar *s = *sptr;
2439 int x = eval_term(&s, decimal, error);
2440 if (*error == NULL)
2441 {
2442 while (*s == '*' || *s == '/')
2443 {
2444 int op = *s++;
2445 int y = eval_term(&s, decimal, error);
2446 if (*error != NULL) break;
2447 if (op == '*') x *= y; else x /= y;
2448 }
2449 }
2450 *sptr = s;
2451 return x;
2452 }
2453
2454
2455
2456
2457 /*************************************************
2458 * Expand string *
2459 *************************************************/
2460
2461 /* Returns either an unchanged string, or the expanded string in stacking pool
2462 store. Interpreted sequences are:
2463
2464 \... normal escaping rules
2465 $name substitutes the variable
2466 ${name} ditto
2467 ${op:string} operates on the expanded string value
2468 ${item{arg1}{arg2}...} expands the args and then does the business
2469 some literal args are not enclosed in {}
2470
2471 There are now far too many operators and item types to make it worth listing
2472 them here in detail any more.
2473
2474 We use an internal routine recursively to handle embedded substrings. The
2475 external function follows. The yield is NULL if the expansion failed, and there
2476 are two cases: if something collapsed syntactically, or if "fail" was given
2477 as the action on a lookup failure. These can be distinguised by looking at the
2478 variable expand_string_forcedfail, which is TRUE in the latter case.
2479
2480 The skipping flag is set true when expanding a substring that isn't actually
2481 going to be used (after "if" or "lookup") and it prevents lookups from
2482 happening lower down.
2483
2484 Store usage: At start, a store block of the length of the input plus 64
2485 is obtained. This is expanded as necessary by string_cat(), which might have to
2486 get a new block, or might be able to expand the original. At the end of the
2487 function we can release any store above that portion of the yield block that
2488 was actually used. In many cases this will be optimal.
2489
2490 However: if the first item in the expansion is a variable name or header name,
2491 we reset the store before processing it; if the result is in fresh store, we
2492 use that without copying. This is helpful for expanding strings like
2493 $message_headers which can get very long.
2494
2495 Arguments:
2496 string the string to be expanded
2497 ket_ends true if expansion is to stop at }
2498 left if not NULL, a pointer to the first character after the
2499 expansion is placed here (typically used with ket_ends)
2500 skipping TRUE for recursive calls when the value isn't actually going
2501 to be used (to allow for optimisation)
2502
2503 Returns: NULL if expansion fails:
2504 expand_string_forcedfail is set TRUE if failure was forced
2505 expand_string_message contains a textual error message
2506 a pointer to the expanded string on success
2507 */
2508
2509 static uschar *
2510 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
2511 BOOL skipping)
2512 {
2513 int ptr = 0;
2514 int size = Ustrlen(string)+ 64;
2515 int item_type;
2516 uschar *yield = store_get(size);
2517 uschar *s = string;
2518 uschar *save_expand_nstring[EXPAND_MAXN+1];
2519 int save_expand_nlength[EXPAND_MAXN+1];
2520
2521 expand_string_forcedfail = FALSE;
2522 expand_string_message = US"";
2523
2524 while (*s != 0)
2525 {
2526 uschar *value;
2527 uschar name[256];
2528
2529 /* \ escapes the next character, which must exist, or else
2530 the expansion fails. There's a special escape, \N, which causes
2531 copying of the subject verbatim up to the next \N. Otherwise,
2532 the escapes are the standard set. */
2533
2534 if (*s == '\\')
2535 {
2536 if (s[1] == 0)
2537 {
2538 expand_string_message = US"\\ at end of string";
2539 goto EXPAND_FAILED;
2540 }
2541
2542 if (s[1] == 'N')
2543 {
2544 uschar *t = s + 2;
2545 for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
2546 yield = string_cat(yield, &size, &ptr, t, s - t);
2547 if (*s != 0) s += 2;
2548 }
2549
2550 else
2551 {
2552 uschar ch[1];
2553 ch[0] = string_interpret_escape(&s);
2554 s++;
2555 yield = string_cat(yield, &size, &ptr, ch, 1);
2556 }
2557
2558 continue;
2559 }
2560
2561 /* Anything other than $ is just copied verbatim, unless we are
2562 looking for a terminating } character. */
2563
2564 if (ket_ends && *s == '}') break;
2565
2566 if (*s != '$')
2567 {
2568 yield = string_cat(yield, &size, &ptr, s++, 1);
2569 continue;
2570 }
2571
2572 /* No { after the $ - must be a plain name or a number for string
2573 match variable. There has to be a fudge for variables that are the
2574 names of header fields preceded by "$header_" because header field
2575 names can contain any printing characters except space and colon.
2576 For those that don't like typing this much, "$h_" is a synonym for
2577 "$header_". A non-existent header yields a NULL value; nothing is
2578 inserted. */
2579
2580 if (isalpha((*(++s))))
2581 {
2582 int len;
2583 int newsize = 0;
2584
2585 s = read_name(name, sizeof(name), s, US"_");
2586
2587 /* If this is the first thing to be expanded, release the pre-allocated
2588 buffer. */
2589
2590 if (ptr == 0 && yield != NULL)
2591 {
2592 store_reset(yield);
2593 yield = NULL;
2594 size = 0;
2595 }
2596
2597 /* Header */
2598
2599 if (Ustrncmp(name, "h_", 2) == 0 ||
2600 Ustrncmp(name, "rh_", 3) == 0 ||
2601 Ustrncmp(name, "bh_", 3) == 0 ||
2602 Ustrncmp(name, "header_", 7) == 0 ||
2603 Ustrncmp(name, "rheader_", 8) == 0 ||
2604 Ustrncmp(name, "bheader_", 8) == 0)
2605 {
2606 BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
2607 uschar *charset = (name[0] == 'b')? NULL : headers_charset;
2608 s = read_header_name(name, sizeof(name), s);
2609 value = find_header(name, FALSE, &newsize, want_raw, charset);
2610
2611 /* If we didn't find the header, and the header contains a closing brace
2612 characters, this may be a user error where the terminating colon
2613 has been omitted. Set a flag to adjust the error message in this case.
2614 But there is no error here - nothing gets inserted. */
2615
2616 if (value == NULL)
2617 {
2618 if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2619 continue;
2620 }
2621 }
2622
2623 /* Variable */
2624
2625 else
2626 {
2627 value = find_variable(name, FALSE, skipping, &newsize);
2628 if (value == NULL)
2629 {
2630 expand_string_message =
2631 string_sprintf("unknown variable name \"%s\"", name);
2632 goto EXPAND_FAILED;
2633 }
2634 }
2635
2636 /* If the data is known to be in a new buffer, newsize will be set to the
2637 size of that buffer. If this is the first thing in an expansion string,
2638 yield will be NULL; just point it at the new store instead of copying. Many
2639 expansion strings contain just one reference, so this is a useful
2640 optimization, especially for humungous headers. */
2641
2642 len = Ustrlen(value);
2643 if (yield == NULL && newsize != 0)
2644 {
2645 yield = value;
2646 size = newsize;
2647 ptr = len;
2648 }
2649 else yield = string_cat(yield, &size, &ptr, value, len);
2650
2651 continue;
2652 }
2653
2654 if (isdigit(*s))
2655 {
2656 int n;
2657 s = read_number(&n, s);
2658 if (n >= 0 && n <= expand_nmax)
2659 yield = string_cat(yield, &size, &ptr, expand_nstring[n],
2660 expand_nlength[n]);
2661 continue;
2662 }
2663
2664 /* Otherwise, if there's no '{' after $ it's an error. */
2665
2666 if (*s != '{')
2667 {
2668 expand_string_message = US"$ not followed by letter, digit, or {";
2669 goto EXPAND_FAILED;
2670 }
2671
2672 /* After { there can be various things, but they all start with
2673 an initial word, except for a number for a string match variable. */
2674
2675 if (isdigit((*(++s))))
2676 {
2677 int n;
2678 s = read_number(&n, s);
2679 if (*s++ != '}')
2680 {
2681 expand_string_message = US"} expected after number";
2682 goto EXPAND_FAILED;
2683 }
2684 if (n >= 0 && n <= expand_nmax)
2685 yield = string_cat(yield, &size, &ptr, expand_nstring[n],
2686 expand_nlength[n]);
2687 continue;
2688 }
2689
2690 if (!isalpha(*s))
2691 {
2692 expand_string_message = US"letter or digit expected after ${";
2693 goto EXPAND_FAILED;
2694 }
2695
2696 /* Allow "-" in names to cater for substrings with negative
2697 arguments. Since we are checking for known names after { this is
2698 OK. */
2699
2700 s = read_name(name, sizeof(name), s, US"_-");
2701 item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
2702
2703 switch(item_type)
2704 {
2705 /* Handle conditionals - preserve the values of the numerical expansion
2706 variables in case they get changed by a regular expression match in the
2707 condition. If not, they retain their external settings. At the end
2708 of this "if" section, they get restored to their previous values. */
2709
2710 case EITEM_IF:
2711 {
2712 BOOL cond = FALSE;
2713 uschar *next_s;
2714 int save_expand_nmax =
2715 save_expand_strings(save_expand_nstring, save_expand_nlength);
2716
2717 while (isspace(*s)) s++;
2718 next_s = eval_condition(s, skipping? NULL : &cond);
2719 if (next_s == NULL) goto EXPAND_FAILED; /* message already set */
2720
2721 DEBUG(D_expand)
2722 debug_printf("condition: %.*s\n result: %s\n", (int)(next_s - s), s,
2723 cond? "true" : "false");
2724
2725 s = next_s;
2726
2727 /* The handling of "yes" and "no" result strings is now in a separate
2728 function that is also used by ${lookup} and ${extract} and ${run}. */
2729
2730 switch(process_yesno(
2731 skipping, /* were previously skipping */
2732 cond, /* success/failure indicator */
2733 lookup_value, /* value to reset for string2 */
2734 &s, /* input pointer */
2735 &yield, /* output pointer */
2736 &size, /* output size */
2737 &ptr, /* output current point */
2738 US"if")) /* condition type */
2739 {
2740 case 1: goto EXPAND_FAILED; /* when all is well, the */
2741 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
2742 }
2743
2744 /* Restore external setting of expansion variables for continuation
2745 at this level. */
2746
2747 restore_expand_strings(save_expand_nmax, save_expand_nstring,
2748 save_expand_nlength);
2749 continue;
2750 }
2751
2752 /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
2753 expanding an internal string that isn't actually going to be used. All we
2754 need to do is check the syntax, so don't do a lookup at all. Preserve the
2755 values of the numerical expansion variables in case they get changed by a
2756 partial lookup. If not, they retain their external settings. At the end
2757 of this "lookup" section, they get restored to their previous values. */
2758
2759 case EITEM_LOOKUP:
2760 {
2761 int stype, partial, affixlen, starflags;
2762 int expand_setup = 0;
2763 int nameptr = 0;
2764 uschar *key, *filename, *affix;
2765 uschar *save_lookup_value = lookup_value;
2766 int save_expand_nmax =
2767 save_expand_strings(save_expand_nstring, save_expand_nlength);
2768
2769 if ((expand_forbid & RDO_LOOKUP) != 0)
2770 {
2771 expand_string_message = US"lookup expansions are not permitted";
2772 goto EXPAND_FAILED;
2773 }
2774
2775 /* Get the key we are to look up for single-key+file style lookups.
2776 Otherwise set the key NULL pro-tem. */
2777
2778 while (isspace(*s)) s++;
2779 if (*s == '{')
2780 {
2781 key = expand_string_internal(s+1, TRUE, &s, skipping);
2782 if (key == NULL) goto EXPAND_FAILED;
2783 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
2784 while (isspace(*s)) s++;
2785 }
2786 else key = NULL;
2787
2788 /* Find out the type of database */
2789
2790 if (!isalpha(*s))
2791 {
2792 expand_string_message = US"missing lookup type";
2793 goto EXPAND_FAILED;
2794 }
2795
2796 /* The type is a string that may contain special characters of various
2797 kinds. Allow everything except space or { to appear; the actual content
2798 is checked by search_findtype_partial. */
2799
2800 while (*s != 0 && *s != '{' && !isspace(*s))
2801 {
2802 if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
2803 s++;
2804 }
2805 name[nameptr] = 0;
2806 while (isspace(*s)) s++;
2807
2808 /* Now check for the individual search type and any partial or default
2809 options. Only those types that are actually in the binary are valid. */
2810
2811 stype = search_findtype_partial(name, &partial, &affix, &affixlen,
2812 &starflags);
2813 if (stype < 0)
2814 {
2815 expand_string_message = search_error_message;
2816 goto EXPAND_FAILED;
2817 }
2818
2819 /* Check that a key was provided for those lookup types that need it,
2820 and was not supplied for those that use the query style. */
2821
2822 if (!mac_islookup(stype, lookup_querystyle))
2823 {
2824 if (key == NULL)
2825 {
2826 expand_string_message = string_sprintf("missing {key} for single-"
2827 "key \"%s\" lookup", name);
2828 goto EXPAND_FAILED;
2829 }
2830 }
2831 else
2832 {
2833 if (key != NULL)
2834 {
2835 expand_string_message = string_sprintf("a single key was given for "
2836 "lookup type \"%s\", which is not a single-key lookup type", name);
2837 goto EXPAND_FAILED;
2838 }
2839 }
2840
2841 /* Get the next string in brackets and expand it. It is the file name for
2842 single-key+file lookups, and the whole query otherwise. */
2843
2844 if (*s != '{') goto EXPAND_FAILED_CURLY;
2845 filename = expand_string_internal(s+1, TRUE, &s, skipping);
2846 if (filename == NULL) goto EXPAND_FAILED;
2847 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
2848 while (isspace(*s)) s++;
2849
2850 /* If this isn't a single-key+file lookup, re-arrange the variables
2851 to be appropriate for the search_ functions. */
2852
2853 if (key == NULL)
2854 {
2855 key = filename;
2856 filename = NULL;
2857 }
2858
2859 /* If skipping, don't do the next bit - just lookup_value == NULL, as if
2860 the entry was not found. Note that there is no search_close() function.
2861 Files are left open in case of re-use. At suitable places in higher logic,
2862 search_tidyup() is called to tidy all open files. This can save opening
2863 the same file several times. However, files may also get closed when
2864 others are opened, if too many are open at once. The rule is that a
2865 handle should not be used after a second search_open().
2866
2867 Request that a partial search sets up $1 and maybe $2 by passing
2868 expand_setup containing zero. If its value changes, reset expand_nmax,
2869 since new variables will have been set. Note that at the end of this
2870 "lookup" section, the old numeric variables are restored. */
2871
2872 if (skipping)
2873 lookup_value = NULL;
2874 else
2875 {
2876 void *handle = search_open(filename, stype, 0, NULL, NULL);
2877 if (handle == NULL)
2878 {
2879 expand_string_message = search_error_message;
2880 goto EXPAND_FAILED;
2881 }
2882 lookup_value = search_find(handle, filename, key, partial, affix,
2883 affixlen, starflags, &expand_setup);
2884 if (search_find_defer)
2885 {
2886 expand_string_message =
2887 string_sprintf("lookup of \"%s\" gave DEFER: %s", key,
2888 search_error_message);
2889 goto EXPAND_FAILED;
2890 }
2891 if (expand_setup > 0) expand_nmax = expand_setup;
2892 }
2893
2894 /* The handling of "yes" and "no" result strings is now in a separate
2895 function that is also used by ${if} and ${extract}. */
2896
2897 switch(process_yesno(
2898 skipping, /* were previously skipping */
2899 lookup_value != NULL, /* success/failure indicator */
2900 save_lookup_value, /* value to reset for string2 */
2901 &s, /* input pointer */
2902 &yield, /* output pointer */
2903 &size, /* output size */
2904 &ptr, /* output current point */
2905 US"lookup")) /* condition type */
2906 {
2907 case 1: goto EXPAND_FAILED; /* when all is well, the */
2908 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
2909 }
2910
2911 /* Restore external setting of expansion variables for carrying on
2912 at this level, and continue. */
2913
2914 restore_expand_strings(save_expand_nmax, save_expand_nstring,
2915 save_expand_nlength);
2916 continue;
2917 }
2918
2919 /* If Perl support is configured, handle calling embedded perl subroutines,
2920 unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
2921 or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
2922 arguments (defined below). */
2923
2924 #ifdef EXIM_PERL
2925 #define EXIM_PERL_MAX_ARGS 8
2926
2927 case EITEM_PERL:
2928 {
2929 uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
2930 uschar *new_yield;
2931
2932 if ((expand_forbid & RDO_PERL) != 0)
2933 {
2934 expand_string_message = US"Perl calls are not permitted";
2935 goto EXPAND_FAILED;
2936 }
2937
2938 switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
2939 US"perl"))
2940 {
2941 case 1: goto EXPAND_FAILED_CURLY;
2942 case 2:
2943 case 3: goto EXPAND_FAILED;
2944 }
2945
2946 /* If skipping, we don't actually do anything */
2947
2948 if (skipping) continue;
2949
2950 /* Start the interpreter if necessary */
2951
2952 if (!opt_perl_started)
2953 {
2954 uschar *initerror;
2955 if (opt_perl_startup == NULL)
2956 {
2957 expand_string_message = US"A setting of perl_startup is needed when "
2958 "using the Perl interpreter";
2959 goto EXPAND_FAILED;
2960 }
2961 DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
2962 initerror = init_perl(opt_perl_startup);
2963 if (initerror != NULL)
2964 {
2965 expand_string_message =
2966 string_sprintf("error in perl_startup code: %s\n", initerror);
2967 goto EXPAND_FAILED;
2968 }
2969 opt_perl_started = TRUE;
2970 }
2971
2972 /* Call the function */
2973
2974 sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
2975 new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
2976 sub_arg[0], sub_arg + 1);
2977
2978 /* NULL yield indicates failure; if the message pointer has been set to
2979 NULL, the yield was undef, indicating a forced failure. Otherwise the
2980 message will indicate some kind of Perl error. */
2981
2982 if (new_yield == NULL)
2983 {
2984 if (expand_string_message == NULL)
2985 {
2986 expand_string_message =
2987 string_sprintf("Perl subroutine \"%s\" returned undef to force "
2988 "failure", sub_arg[0]);
2989 expand_string_forcedfail = TRUE;
2990 }
2991 goto EXPAND_FAILED;
2992 }
2993
2994 /* Yield succeeded. Ensure forcedfail is unset, just in case it got
2995 set during a callback from Perl. */
2996
2997 expand_string_forcedfail = FALSE;
2998 yield = new_yield;
2999 continue;
3000 }
3001 #endif /* EXIM_PERL */
3002
3003 /* Handle "readfile" to insert an entire file */
3004
3005 case EITEM_READFILE:
3006 {
3007 FILE *f;
3008 uschar *sub_arg[2];
3009
3010 if ((expand_forbid & RDO_READFILE) != 0)
3011 {
3012 expand_string_message = US"file insertions are not permitted";
3013 goto EXPAND_FAILED;
3014 }
3015
3016 switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
3017 {
3018 case 1: goto EXPAND_FAILED_CURLY;
3019 case 2:
3020 case 3: goto EXPAND_FAILED;
3021 }
3022
3023 /* If skipping, we don't actually do anything */
3024
3025 if (skipping) continue;
3026
3027 /* Open the file and read it */
3028
3029 f = Ufopen(sub_arg[0], "rb");
3030 if (f == NULL)
3031 {
3032 expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
3033 goto EXPAND_FAILED;
3034 }
3035
3036 yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
3037 fclose(f);
3038 continue;
3039 }
3040
3041 /* Handle "readsocket" to insert data from a Unix domain socket */
3042
3043 case EITEM_READSOCK:
3044 {
3045 int fd;
3046 int timeout = 5;
3047 int save_ptr = ptr;
3048 FILE *f;
3049 struct sockaddr_un sockun; /* don't call this "sun" ! */
3050 uschar *arg;
3051 uschar *sub_arg[4];
3052
3053 if ((expand_forbid & RDO_READSOCK) != 0)
3054 {
3055 expand_string_message = US"socket insertions are not permitted";
3056 goto EXPAND_FAILED;
3057 }
3058
3059 /* Read up to 4 arguments, but don't do the end of item check afterwards,
3060 because there may be a string for expansion on failure. */
3061
3062 switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
3063 {
3064 case 1: goto EXPAND_FAILED_CURLY;
3065 case 2: /* Won't occur: no end check */
3066 case 3: goto EXPAND_FAILED;
3067 }
3068
3069 /* Sort out timeout, if given */
3070
3071 if (sub_arg[2] != NULL)
3072 {
3073 timeout = readconf_readtime(sub_arg[2], 0, FALSE);
3074 if (timeout < 0)
3075 {
3076 expand_string_message = string_sprintf("bad time value %s",
3077 sub_arg[2]);
3078 goto EXPAND_FAILED;
3079 }
3080 }
3081 else sub_arg[3] = NULL; /* No eol if no timeout */
3082
3083 /* If skipping, we don't actually do anything */
3084
3085 if (!skipping)
3086 {
3087 /* Make a connection to the socket */
3088
3089 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
3090 {
3091 expand_string_message = string_sprintf("failed to create socket: %s",
3092 strerror(errno));
3093 goto SOCK_FAIL;
3094 }
3095
3096 sockun.sun_family = AF_UNIX;
3097 sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
3098 sub_arg[0]);
3099 if(connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun)) == -1)
3100 {
3101 expand_string_message = string_sprintf("failed to connect to socket "
3102 "%s: %s", sub_arg[0], strerror(errno));
3103 goto SOCK_FAIL;
3104 }
3105 DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
3106
3107 /* Write the request string, if not empty */
3108
3109 if (sub_arg[1][0] != 0)
3110 {
3111 int len = Ustrlen(sub_arg[1]);
3112 DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
3113 sub_arg[1]);
3114 if (write(fd, sub_arg[1], len) != len)
3115 {
3116 expand_string_message = string_sprintf("request write to socket "
3117 "failed: %s", strerror(errno));
3118 goto SOCK_FAIL;
3119 }
3120 }
3121
3122 /* Now we need to read from the socket, under a timeout. The function
3123 that reads a file can be used. */
3124
3125 f = fdopen(fd, "rb");
3126 sigalrm_seen = FALSE;
3127 alarm(timeout);
3128 yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
3129 alarm(0);
3130 fclose(f);
3131
3132 /* After a timeout, we restore the pointer in the result, that is,
3133 make sure we add nothing from the socket. */
3134
3135 if (sigalrm_seen)
3136 {
3137 ptr = save_ptr;
3138 expand_string_message = US"socket read timed out";
3139 goto SOCK_FAIL;
3140 }
3141 }
3142
3143 /* The whole thing has worked (or we were skipping). If there is a
3144 failure string following, we need to skip it. */
3145
3146 if (*s == '{')
3147 {
3148 if (expand_string_internal(s+1, TRUE, &s, TRUE) == NULL)
3149 goto EXPAND_FAILED;
3150 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3151 while (isspace(*s)) s++;
3152 }
3153 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3154 continue;
3155
3156 /* Come here on failure to create socket, connect socket, write to the
3157 socket, or timeout on reading. If another substring follows, expand and
3158 use it. Otherwise, those conditions give expand errors. */
3159
3160 SOCK_FAIL:
3161 if (*s != '{') goto EXPAND_FAILED;
3162 DEBUG(D_any) debug_printf("%s\n", expand_string_message);
3163 arg = expand_string_internal(s+1, TRUE, &s, FALSE);
3164 if (arg == NULL) goto EXPAND_FAILED;
3165 yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
3166 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3167 while (isspace(*s)) s++;
3168 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3169 continue;
3170 }
3171
3172 /* Handle "run" to execute a program. */
3173
3174 case EITEM_RUN:
3175 {
3176 FILE *f;
3177 uschar *old_lookup_value = NULL;
3178 uschar *arg;
3179 uschar **argv;
3180 pid_t pid;
3181 int fd_in, fd_out;
3182 int lsize = 0;
3183 int lptr = 0;
3184
3185 if ((expand_forbid & RDO_RUN) != 0)
3186 {
3187 expand_string_message = US"running a command is not permitted";
3188 goto EXPAND_FAILED;
3189 }
3190
3191 while (isspace(*s)) s++;
3192 if (*s != '{') goto EXPAND_FAILED_CURLY;
3193 arg = expand_string_internal(s+1, TRUE, &s, skipping);
3194 if (arg == NULL) goto EXPAND_FAILED;
3195 while (isspace(*s)) s++;
3196 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3197
3198 if (skipping) /* Just pretend it worked when we're skipping */
3199 {
3200 runrc = 0;
3201 }
3202 else
3203 {
3204 if (!transport_set_up_command(&argv, /* anchor for arg list */
3205 arg, /* raw command */
3206 FALSE, /* don't expand the arguments */
3207 0, /* not relevant when... */
3208 NULL, /* no transporting address */
3209 US"${run} expansion", /* for error messages */
3210 &expand_string_message)) /* where to put error message */
3211 {
3212 goto EXPAND_FAILED;
3213 }
3214
3215 /* Create the child process, making it a group leader. */
3216
3217 pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
3218
3219 if (pid < 0)
3220 {
3221 expand_string_message =
3222 string_sprintf("couldn't create child process: %s", strerror(errno));
3223 goto EXPAND_FAILED;
3224 }
3225
3226 /* Nothing is written to the standard input. */
3227
3228 close(fd_in);
3229
3230 /* Wait for the process to finish, applying the timeout, and inspect its
3231 return code for serious disasters. Simple non-zero returns are passed on.
3232 */
3233
3234 if ((runrc = child_close(pid, 60)) < 0)
3235 {
3236 if (runrc == -256)
3237 {
3238 expand_string_message = string_sprintf("command timed out");
3239 killpg(pid, SIGKILL); /* Kill the whole process group */
3240 }
3241
3242 else if (runrc == -257)
3243 expand_string_message = string_sprintf("wait() failed: %s",
3244 strerror(errno));
3245
3246 else
3247 expand_string_message = string_sprintf("command killed by signal %d",
3248 -runrc);
3249
3250 goto EXPAND_FAILED;
3251 }
3252
3253 /* Read the pipe to get the command's output into $value (which is kept
3254 in lookup_value). */
3255
3256 f = fdopen(fd_out, "rb");
3257 old_lookup_value = lookup_value;
3258 lookup_value = NULL;
3259 lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
3260 fclose(f);
3261 }
3262
3263 /* Process the yes/no strings */
3264
3265 switch(process_yesno(
3266 skipping, /* were previously skipping */
3267 runrc == 0, /* success/failure indicator */
3268 old_lookup_value, /* value to reset for string2 */
3269 &s, /* input pointer */
3270 &yield, /* output pointer */
3271 &size, /* output size */
3272 &ptr, /* output current point */
3273 US"run")) /* condition type */
3274 {
3275 case 1: goto EXPAND_FAILED; /* when all is well, the */
3276 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
3277 }
3278
3279 continue;
3280 }
3281
3282 /* Handle character translation for "tr" */
3283
3284 case EITEM_TR:
3285 {
3286 int oldptr = ptr;
3287 int o2m;
3288 uschar *sub[3];
3289
3290 switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
3291 {
3292 case 1: goto EXPAND_FAILED_CURLY;
3293 case 2:
3294 case 3: goto EXPAND_FAILED;
3295 }
3296
3297 yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
3298 o2m = Ustrlen(sub[2]) - 1;
3299
3300 if (o2m >= 0) for (; oldptr < ptr; oldptr++)
3301 {
3302 uschar *m = Ustrrchr(sub[1], yield[oldptr]);
3303 if (m != NULL)
3304 {
3305 int o = m - sub[1];
3306 yield[oldptr] = sub[2][(o < o2m)? o : o2m];
3307 }
3308 }
3309
3310 continue;
3311 }
3312
3313 /* Handle "hash", "length", "nhash", and "substr" when they are given with
3314 expanded arguments. */
3315
3316 case EITEM_HASH:
3317 case EITEM_LENGTH:
3318 case EITEM_NHASH:
3319 case EITEM_SUBSTR:
3320 {
3321 int i;
3322 int len;
3323 uschar *ret;
3324 int val[2] = { 0, -1 };
3325 uschar *sub[3];
3326
3327 /* "length" takes only 2 arguments whereas the others take 2 or 3.
3328 Ensure that sub[2] is set in the ${length case. */
3329
3330 sub[2] = NULL;
3331 switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
3332 TRUE, name))
3333 {
3334 case 1: goto EXPAND_FAILED_CURLY;
3335 case 2:
3336 case 3: goto EXPAND_FAILED;
3337 }
3338
3339 /* Juggle the arguments if there are only two of them: always move the
3340 string to the last position and make ${length{n}{str}} equivalent to
3341 ${substr{0}{n}{str}}. See the defaults for val[] above. */
3342
3343 if (sub[2] == NULL)
3344 {
3345 sub[2] = sub[1];
3346 sub[1] = NULL;
3347 if (item_type == EITEM_LENGTH)
3348 {
3349 sub[1] = sub[0];
3350 sub[0] = NULL;
3351 }
3352 }
3353
3354 for (i = 0; i < 2; i++)
3355 {
3356 if (sub[i] == NULL) continue;
3357 val[i] = (int)Ustrtol(sub[i], &ret, 10);
3358 if (*ret != 0 || (i != 0 && val[i] < 0))
3359 {
3360 expand_string_message = string_sprintf("\"%s\" is not a%s number "
3361 "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
3362 goto EXPAND_FAILED;
3363 }
3364 }
3365
3366 ret =
3367 (item_type == EITEM_HASH)?
3368 compute_hash(sub[2], val[0], val[1], &len) :
3369 (item_type == EITEM_NHASH)?
3370 compute_nhash(sub[2], val[0], val[1], &len) :
3371 extract_substr(sub[2], val[0], val[1], &len);
3372
3373 if (ret == NULL) goto EXPAND_FAILED;
3374 yield = string_cat(yield, &size, &ptr, ret, len);
3375 continue;
3376 }
3377
3378 /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
3379 This code originally contributed by Steve Haslam. It currently supports
3380 the use of MD5 and SHA-1 hashes.
3381
3382 We need some workspace that is large enough to handle all the supported
3383 hash types. Use macros to set the sizes rather than be too elaborate. */
3384
3385 #define MAX_HASHLEN 20
3386 #define MAX_HASHBLOCKLEN 64
3387
3388 case EITEM_HMAC:
3389 {
3390 uschar *sub[3];
3391 md5 md5_base;
3392 sha1 sha1_base;
3393 void *use_base;
3394 int type, i;
3395 int hashlen; /* Number of octets for the hash algorithm's output */
3396 int hashblocklen; /* Number of octets the hash algorithm processes */
3397 uschar *keyptr, *p;