1bdcd3760c0d061055d258985232d1ef53a4337c
[exim.git] / src / src / expand.c
1 /* $Cambridge: exim/src/src/expand.c,v 1.7 2004/11/18 11:17:33 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 vtype_pspace, /* partition space; value is T/F for spool/log */
288 vtype_pinodes /* partition inodes; value is T/F for spool/log */
289 };
290
291 /* This table must be kept in alphabetical order. */
292
293 static var_entry var_table[] = {
294 { "acl_c0", vtype_stringptr, &acl_var[0] },
295 { "acl_c1", vtype_stringptr, &acl_var[1] },
296 { "acl_c2", vtype_stringptr, &acl_var[2] },
297 { "acl_c3", vtype_stringptr, &acl_var[3] },
298 { "acl_c4", vtype_stringptr, &acl_var[4] },
299 { "acl_c5", vtype_stringptr, &acl_var[5] },
300 { "acl_c6", vtype_stringptr, &acl_var[6] },
301 { "acl_c7", vtype_stringptr, &acl_var[7] },
302 { "acl_c8", vtype_stringptr, &acl_var[8] },
303 { "acl_c9", vtype_stringptr, &acl_var[9] },
304 { "acl_m0", vtype_stringptr, &acl_var[10] },
305 { "acl_m1", vtype_stringptr, &acl_var[11] },
306 { "acl_m2", vtype_stringptr, &acl_var[12] },
307 { "acl_m3", vtype_stringptr, &acl_var[13] },
308 { "acl_m4", vtype_stringptr, &acl_var[14] },
309 { "acl_m5", vtype_stringptr, &acl_var[15] },
310 { "acl_m6", vtype_stringptr, &acl_var[16] },
311 { "acl_m7", vtype_stringptr, &acl_var[17] },
312 { "acl_m8", vtype_stringptr, &acl_var[18] },
313 { "acl_m9", vtype_stringptr, &acl_var[19] },
314 { "acl_verify_message", vtype_stringptr, &acl_verify_message },
315 { "address_data", vtype_stringptr, &deliver_address_data },
316 { "address_file", vtype_stringptr, &address_file },
317 { "address_pipe", vtype_stringptr, &address_pipe },
318 { "authenticated_id", vtype_stringptr, &authenticated_id },
319 { "authenticated_sender",vtype_stringptr, &authenticated_sender },
320 { "authentication_failed",vtype_int, &authentication_failed },
321 { "body_linecount", vtype_int, &body_linecount },
322 { "body_zerocount", vtype_int, &body_zerocount },
323 { "bounce_recipient", vtype_stringptr, &bounce_recipient },
324 { "bounce_return_size_limit", vtype_int, &bounce_return_size_limit },
325 { "caller_gid", vtype_gid, &real_gid },
326 { "caller_uid", vtype_uid, &real_uid },
327 { "compile_date", vtype_stringptr, &version_date },
328 { "compile_number", vtype_stringptr, &version_cnumber },
329 { "dnslist_domain", vtype_stringptr, &dnslist_domain },
330 { "dnslist_text", vtype_stringptr, &dnslist_text },
331 { "dnslist_value", vtype_stringptr, &dnslist_value },
332 { "domain", vtype_stringptr, &deliver_domain },
333 { "domain_data", vtype_stringptr, &deliver_domain_data },
334 { "exim_gid", vtype_gid, &exim_gid },
335 { "exim_path", vtype_stringptr, &exim_path },
336 { "exim_uid", vtype_uid, &exim_uid },
337 { "home", vtype_stringptr, &deliver_home },
338 { "host", vtype_stringptr, &deliver_host },
339 { "host_address", vtype_stringptr, &deliver_host_address },
340 { "host_data", vtype_stringptr, &host_data },
341 { "host_lookup_failed", vtype_int, &host_lookup_failed },
342 { "inode", vtype_ino, &deliver_inode },
343 { "interface_address", vtype_stringptr, &interface_address },
344 { "interface_port", vtype_int, &interface_port },
345 #ifdef LOOKUP_LDAP
346 { "ldap_dn", vtype_stringptr, &eldap_dn },
347 #endif
348 { "load_average", vtype_load_avg, NULL },
349 { "local_part", vtype_stringptr, &deliver_localpart },
350 { "local_part_data", vtype_stringptr, &deliver_localpart_data },
351 { "local_part_prefix", vtype_stringptr, &deliver_localpart_prefix },
352 { "local_part_suffix", vtype_stringptr, &deliver_localpart_suffix },
353 { "local_scan_data", vtype_stringptr, &local_scan_data },
354 { "local_user_gid", vtype_gid, &local_user_gid },
355 { "local_user_uid", vtype_uid, &local_user_uid },
356 { "localhost_number", vtype_int, &host_number },
357 { "log_inodes", vtype_pinodes, (void *)FALSE },
358 { "log_space", vtype_pspace, (void *)FALSE },
359 { "mailstore_basename", vtype_stringptr, &mailstore_basename },
360 { "message_age", vtype_int, &message_age },
361 { "message_body", vtype_msgbody, &message_body },
362 { "message_body_end", vtype_msgbody_end, &message_body_end },
363 { "message_body_size", vtype_int, &message_body_size },
364 { "message_headers", vtype_msgheaders, NULL },
365 { "message_id", vtype_stringptr, &message_id },
366 { "message_size", vtype_int, &message_size },
367 { "n0", vtype_filter_int, &filter_n[0] },
368 { "n1", vtype_filter_int, &filter_n[1] },
369 { "n2", vtype_filter_int, &filter_n[2] },
370 { "n3", vtype_filter_int, &filter_n[3] },
371 { "n4", vtype_filter_int, &filter_n[4] },
372 { "n5", vtype_filter_int, &filter_n[5] },
373 { "n6", vtype_filter_int, &filter_n[6] },
374 { "n7", vtype_filter_int, &filter_n[7] },
375 { "n8", vtype_filter_int, &filter_n[8] },
376 { "n9", vtype_filter_int, &filter_n[9] },
377 { "original_domain", vtype_stringptr, &deliver_domain_orig },
378 { "original_local_part", vtype_stringptr, &deliver_localpart_orig },
379 { "originator_gid", vtype_gid, &originator_gid },
380 { "originator_uid", vtype_uid, &originator_uid },
381 { "parent_domain", vtype_stringptr, &deliver_domain_parent },
382 { "parent_local_part", vtype_stringptr, &deliver_localpart_parent },
383 { "pid", vtype_pid, NULL },
384 { "primary_hostname", vtype_stringptr, &primary_hostname },
385 { "qualify_domain", vtype_stringptr, &qualify_domain_sender },
386 { "qualify_recipient", vtype_stringptr, &qualify_domain_recipient },
387 { "rcpt_count", vtype_int, &rcpt_count },
388 { "rcpt_defer_count", vtype_int, &rcpt_defer_count },
389 { "rcpt_fail_count", vtype_int, &rcpt_fail_count },
390 { "received_count", vtype_int, &received_count },
391 { "received_for", vtype_stringptr, &received_for },
392 { "received_protocol", vtype_stringptr, &received_protocol },
393 { "recipient_data", vtype_stringptr, &recipient_data },
394 { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
395 { "recipients", vtype_recipients, NULL },
396 { "recipients_count", vtype_int, &recipients_count },
397 { "reply_address", vtype_reply, NULL },
398 { "return_path", vtype_stringptr, &return_path },
399 { "return_size_limit", vtype_int, &bounce_return_size_limit },
400 { "runrc", vtype_int, &runrc },
401 { "self_hostname", vtype_stringptr, &self_hostname },
402 { "sender_address", vtype_stringptr, &sender_address },
403 { "sender_address_data", vtype_stringptr, &sender_address_data },
404 { "sender_address_domain", vtype_domain, &sender_address },
405 { "sender_address_local_part", vtype_localpart, &sender_address },
406 { "sender_data", vtype_stringptr, &sender_data },
407 { "sender_fullhost", vtype_stringptr, &sender_fullhost },
408 { "sender_helo_name", vtype_stringptr, &sender_helo_name },
409 { "sender_host_address", vtype_stringptr, &sender_host_address },
410 { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
411 { "sender_host_name", vtype_host_lookup, NULL },
412 { "sender_host_port", vtype_int, &sender_host_port },
413 { "sender_ident", vtype_stringptr, &sender_ident },
414 { "sender_rcvhost", vtype_stringptr, &sender_rcvhost },
415 { "sender_verify_failure",vtype_stringptr, &sender_verify_failure },
416 { "smtp_command_argument", vtype_stringptr, &smtp_command_argument },
417 { "sn0", vtype_filter_int, &filter_sn[0] },
418 { "sn1", vtype_filter_int, &filter_sn[1] },
419 { "sn2", vtype_filter_int, &filter_sn[2] },
420 { "sn3", vtype_filter_int, &filter_sn[3] },
421 { "sn4", vtype_filter_int, &filter_sn[4] },
422 { "sn5", vtype_filter_int, &filter_sn[5] },
423 { "sn6", vtype_filter_int, &filter_sn[6] },
424 { "sn7", vtype_filter_int, &filter_sn[7] },
425 { "sn8", vtype_filter_int, &filter_sn[8] },
426 { "sn9", vtype_filter_int, &filter_sn[9] },
427 { "spool_directory", vtype_stringptr, &spool_directory },
428 { "spool_inodes", vtype_pinodes, (void *)TRUE },
429 { "spool_space", vtype_pspace, (void *)TRUE },
430 { "thisaddress", vtype_stringptr, &filter_thisaddress },
431 { "tls_certificate_verified", vtype_int, &tls_certificate_verified },
432 { "tls_cipher", vtype_stringptr, &tls_cipher },
433 { "tls_peerdn", vtype_stringptr, &tls_peerdn },
434 { "tod_bsdinbox", vtype_todbsdin, NULL },
435 { "tod_epoch", vtype_tode, NULL },
436 { "tod_full", vtype_todf, NULL },
437 { "tod_log", vtype_todl, NULL },
438 { "tod_logfile", vtype_todlf, NULL },
439 { "tod_zone", vtype_todzone, NULL },
440 { "tod_zulu", vtype_todzulu, NULL },
441 { "value", vtype_stringptr, &lookup_value },
442 { "version_number", vtype_stringptr, &version_string },
443 { "warn_message_delay", vtype_stringptr, &warnmsg_delay },
444 { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
445 { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
446 { "warnmsg_delay", vtype_stringptr, &warnmsg_delay },
447 { "warnmsg_recipient", vtype_stringptr, &warnmsg_recipients },
448 { "warnmsg_recipients", vtype_stringptr, &warnmsg_recipients }
449 };
450
451 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
452 static uschar var_buffer[256];
453 static BOOL malformed_header;
454
455 /* For textual hashes */
456
457 static char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
458 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
459 "0123456789";
460
461 enum { HMAC_MD5, HMAC_SHA1 };
462
463 /* For numeric hashes */
464
465 static unsigned int prime[] = {
466 2, 3, 5, 7, 11, 13, 17, 19, 23, 29,
467 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
468 73, 79, 83, 89, 97, 101, 103, 107, 109, 113};
469
470 /* For printing modes in symbolic form */
471
472 static uschar *mtable_normal[] =
473 { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
474
475 static uschar *mtable_setid[] =
476 { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
477
478 static uschar *mtable_sticky[] =
479 { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
480
481
482
483 /*************************************************
484 * Tables for UTF-8 support *
485 *************************************************/
486
487 /* Table of the number of extra characters, indexed by the first character
488 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
489 0x3d. */
490
491 static uschar utf8_table1[] = {
492 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
493 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
494 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
495 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
496
497 /* These are the masks for the data bits in the first byte of a character,
498 indexed by the number of additional bytes. */
499
500 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
501
502 /* Get the next UTF-8 character, advancing the pointer. */
503
504 #define GETUTF8INC(c, ptr) \
505 c = *ptr++; \
506 if ((c & 0xc0) == 0xc0) \
507 { \
508 int a = utf8_table1[c & 0x3f]; /* Number of additional bytes */ \
509 int s = 6*a; \
510 c = (c & utf8_table2[a]) << s; \
511 while (a-- > 0) \
512 { \
513 s -= 6; \
514 c |= (*ptr++ & 0x3f) << s; \
515 } \
516 }
517
518
519 /*************************************************
520 * Binary chop search on a table *
521 *************************************************/
522
523 /* This is used for matching expansion items and operators.
524
525 Arguments:
526 name the name that is being sought
527 table the table to search
528 table_size the number of items in the table
529
530 Returns: the offset in the table, or -1
531 */
532
533 static int
534 chop_match(uschar *name, uschar **table, int table_size)
535 {
536 uschar **bot = table;
537 uschar **top = table + table_size;
538
539 while (top > bot)
540 {
541 uschar **mid = bot + (top - bot)/2;
542 int c = Ustrcmp(name, *mid);
543 if (c == 0) return mid - table;
544 if (c > 0) bot = mid + 1; else top = mid;
545 }
546
547 return -1;
548 }
549
550
551
552 /*************************************************
553 * Check a condition string *
554 *************************************************/
555
556 /* This function is called to expand a string, and test the result for a "true"
557 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
558 forced fail or lookup defer. All store used by the function can be released on
559 exit.
560
561 Arguments:
562 condition the condition string
563 m1 text to be incorporated in panic error
564 m2 ditto
565
566 Returns: TRUE if condition is met, FALSE if not
567 */
568
569 BOOL
570 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
571 {
572 int rc;
573 void *reset_point = store_get(0);
574 uschar *ss = expand_string(condition);
575 if (ss == NULL)
576 {
577 if (!expand_string_forcedfail && !search_find_defer)
578 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
579 "for %s %s: %s", condition, m1, m2, expand_string_message);
580 return FALSE;
581 }
582 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
583 strcmpic(ss, US"false") != 0;
584 store_reset(reset_point);
585 return rc;
586 }
587
588
589
590 /*************************************************
591 * Pick out a name from a string *
592 *************************************************/
593
594 /* If the name is too long, it is silently truncated.
595
596 Arguments:
597 name points to a buffer into which to put the name
598 max is the length of the buffer
599 s points to the first alphabetic character of the name
600 extras chars other than alphanumerics to permit
601
602 Returns: pointer to the first character after the name
603
604 Note: The test for *s != 0 in the while loop is necessary because
605 Ustrchr() yields non-NULL if the character is zero (which is not something
606 I expected). */
607
608 static uschar *
609 read_name(uschar *name, int max, uschar *s, uschar *extras)
610 {
611 int ptr = 0;
612 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
613 {
614 if (ptr < max-1) name[ptr++] = *s;
615 s++;
616 }
617 name[ptr] = 0;
618 return s;
619 }
620
621
622
623 /*************************************************
624 * Pick out the rest of a header name *
625 *************************************************/
626
627 /* A variable name starting $header_ (or just $h_ for those who like
628 abbreviations) might not be the complete header name because headers can
629 contain any printing characters in their names, except ':'. This function is
630 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
631 on the end, if the name was terminated by white space.
632
633 Arguments:
634 name points to a buffer in which the name read so far exists
635 max is the length of the buffer
636 s points to the first character after the name so far, i.e. the
637 first non-alphameric character after $header_xxxxx
638
639 Returns: a pointer to the first character after the header name
640 */
641
642 static uschar *
643 read_header_name(uschar *name, int max, uschar *s)
644 {
645 int prelen = Ustrchr(name, '_') - name + 1;
646 int ptr = Ustrlen(name) - prelen;
647 if (ptr > 0) memmove(name, name+prelen, ptr);
648 while (mac_isgraph(*s) && *s != ':')
649 {
650 if (ptr < max-1) name[ptr++] = *s;
651 s++;
652 }
653 if (*s == ':') s++;
654 name[ptr++] = ':';
655 name[ptr] = 0;
656 return s;
657 }
658
659
660
661 /*************************************************
662 * Pick out a number from a string *
663 *************************************************/
664
665 /* Arguments:
666 n points to an integer into which to put the number
667 s points to the first digit of the number
668
669 Returns: a pointer to the character after the last digit
670 */
671
672 static uschar *
673 read_number(int *n, uschar *s)
674 {
675 *n = 0;
676 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
677 return s;
678 }
679
680
681
682 /*************************************************
683 * Extract keyed subfield from a string *
684 *************************************************/
685
686 /* The yield is in dynamic store; NULL means that the key was not found.
687
688 Arguments:
689 key points to the name of the key
690 s points to the string from which to extract the subfield
691
692 Returns: NULL if the subfield was not found, or
693 a pointer to the subfield's data
694 */
695
696 static uschar *
697 expand_getkeyed(uschar *key, uschar *s)
698 {
699 int length = Ustrlen(key);
700 while (isspace(*s)) s++;
701
702 /* Loop to search for the key */
703
704 while (*s != 0)
705 {
706 int dkeylength;
707 uschar *data;
708 uschar *dkey = s;
709
710 while (*s != 0 && *s != '=' && !isspace(*s)) s++;
711 dkeylength = s - dkey;
712 while (isspace(*s)) s++;
713 if (*s == '=') while (isspace((*(++s))));
714
715 data = string_dequote(&s);
716 if (length == dkeylength && strncmpic(key, dkey, length) == 0)
717 return data;
718
719 while (isspace(*s)) s++;
720 }
721
722 return NULL;
723 }
724
725
726
727
728 /*************************************************
729 * Extract numbered subfield from string *
730 *************************************************/
731
732 /* Extracts a numbered field from a string that is divided by tokens - for
733 example a line from /etc/passwd is divided by colon characters. First field is
734 numbered one. Negative arguments count from the right. Zero returns the whole
735 string. Returns NULL if there are insufficient tokens in the string
736
737 ***WARNING***
738 Modifies final argument - this is a dynamically generated string, so that's OK.
739
740 Arguments:
741 field number of field to be extracted,
742 first field = 1, whole string = 0, last field = -1
743 separators characters that are used to break string into tokens
744 s points to the string from which to extract the subfield
745
746 Returns: NULL if the field was not found,
747 a pointer to the field's data inside s (modified to add 0)
748 */
749
750 static uschar *
751 expand_gettokened (int field, uschar *separators, uschar *s)
752 {
753 int sep = 1;
754 int count;
755 uschar *ss = s;
756 uschar *fieldtext = NULL;
757
758 if (field == 0) return s;
759
760 /* Break the line up into fields in place; for field > 0 we stop when we have
761 done the number of fields we want. For field < 0 we continue till the end of
762 the string, counting the number of fields. */
763
764 count = (field > 0)? field : INT_MAX;
765
766 while (count-- > 0)
767 {
768 size_t len;
769
770 /* Previous field was the last one in the string. For a positive field
771 number, this means there are not enough fields. For a negative field number,
772 check that there are enough, and scan back to find the one that is wanted. */
773
774 if (sep == 0)
775 {
776 if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
777 if ((-field) == (INT_MAX - count - 1)) return s;
778 while (field++ < 0)
779 {
780 ss--;
781 while (ss[-1] != 0) ss--;
782 }
783 fieldtext = ss;
784 break;
785 }
786
787 /* Previous field was not last in the string; save its start and put a
788 zero at its end. */
789
790 fieldtext = ss;
791 len = Ustrcspn(ss, separators);
792 sep = ss[len];
793 ss[len] = 0;
794 ss += len + 1;
795 }
796
797 return fieldtext;
798 }
799
800
801
802 /*************************************************
803 * Extract a substring from a string *
804 *************************************************/
805
806 /* Perform the ${substr or ${length expansion operations.
807
808 Arguments:
809 subject the input string
810 value1 the offset from the start of the input string to the start of
811 the output string; if negative, count from the right.
812 value2 the length of the output string, or negative (-1) for unset
813 if value1 is positive, unset means "all after"
814 if value1 is negative, unset means "all before"
815 len set to the length of the returned string
816
817 Returns: pointer to the output string, or NULL if there is an error
818 */
819
820 static uschar *
821 extract_substr(uschar *subject, int value1, int value2, int *len)
822 {
823 int sublen = Ustrlen(subject);
824
825 if (value1 < 0) /* count from right */
826 {
827 value1 += sublen;
828
829 /* If the position is before the start, skip to the start, and adjust the
830 length. If the length ends up negative, the substring is null because nothing
831 can precede. This falls out naturally when the length is unset, meaning "all
832 to the left". */
833
834 if (value1 < 0)
835 {
836 value2 += value1;
837 if (value2 < 0) value2 = 0;
838 value1 = 0;
839 }
840
841 /* Otherwise an unset length => characters before value1 */
842
843 else if (value2 < 0)
844 {
845 value2 = value1;
846 value1 = 0;
847 }
848 }
849
850 /* For a non-negative offset, if the starting position is past the end of the
851 string, the result will be the null string. Otherwise, an unset length means
852 "rest"; just set it to the maximum - it will be cut down below if necessary. */
853
854 else
855 {
856 if (value1 > sublen)
857 {
858 value1 = sublen;
859 value2 = 0;
860 }
861 else if (value2 < 0) value2 = sublen;
862 }
863
864 /* Cut the length down to the maximum possible for the offset value, and get
865 the required characters. */
866
867 if (value1 + value2 > sublen) value2 = sublen - value1;
868 *len = value2;
869 return subject + value1;
870 }
871
872
873
874
875 /*************************************************
876 * Old-style hash of a string *
877 *************************************************/
878
879 /* Perform the ${hash expansion operation.
880
881 Arguments:
882 subject the input string (an expanded substring)
883 value1 the length of the output string; if greater or equal to the
884 length of the input string, the input string is returned
885 value2 the number of hash characters to use, or 26 if negative
886 len set to the length of the returned string
887
888 Returns: pointer to the output string, or NULL if there is an error
889 */
890
891 static uschar *
892 compute_hash(uschar *subject, int value1, int value2, int *len)
893 {
894 int sublen = Ustrlen(subject);
895
896 if (value2 < 0) value2 = 26;
897 else if (value2 > Ustrlen(hashcodes))
898 {
899 expand_string_message =
900 string_sprintf("hash count \"%d\" too big", value2);
901 return NULL;
902 }
903
904 /* Calculate the hash text. We know it is shorter than the original string, so
905 can safely place it in subject[] (we know that subject is always itself an
906 expanded substring). */
907
908 if (value1 < sublen)
909 {
910 int c;
911 int i = 0;
912 int j = value1;
913 while ((c = (subject[j])) != 0)
914 {
915 int shift = (c + j++) & 7;
916 subject[i] ^= (c << shift) | (c >> (8-shift));
917 if (++i >= value1) i = 0;
918 }
919 for (i = 0; i < value1; i++)
920 subject[i] = hashcodes[(subject[i]) % value2];
921 }
922 else value1 = sublen;
923
924 *len = value1;
925 return subject;
926 }
927
928
929
930
931 /*************************************************
932 * Numeric hash of a string *
933 *************************************************/
934
935 /* Perform the ${nhash expansion operation. The first characters of the
936 string are treated as most important, and get the highest prime numbers.
937
938 Arguments:
939 subject the input string
940 value1 the maximum value of the first part of the result
941 value2 the maximum value of the second part of the result,
942 or negative to produce only a one-part result
943 len set to the length of the returned string
944
945 Returns: pointer to the output string, or NULL if there is an error.
946 */
947
948 static uschar *
949 compute_nhash (uschar *subject, int value1, int value2, int *len)
950 {
951 uschar *s = subject;
952 int i = 0;
953 unsigned long int total = 0; /* no overflow */
954
955 while (*s != 0)
956 {
957 if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
958 total += prime[i--] * (unsigned int)(*s++);
959 }
960
961 /* If value2 is unset, just compute one number */
962
963 if (value2 < 0)
964 {
965 s = string_sprintf("%d", total % value1);
966 }
967
968 /* Otherwise do a div/mod hash */
969
970 else
971 {
972 total = total % (value1 * value2);
973 s = string_sprintf("%d/%d", total/value2, total % value2);
974 }
975
976 *len = Ustrlen(s);
977 return s;
978 }
979
980
981
982
983
984 /*************************************************
985 * Find the value of a header or headers *
986 *************************************************/
987
988 /* Multiple instances of the same header get concatenated, and this function
989 can also return a concatenation of all the header lines. When concatenating
990 specific headers that contain lists of addresses, a comma is inserted between
991 them. Otherwise we use a straight concatenation. Because some messages can have
992 pathologically large number of lines, there is a limit on the length that is
993 returned. Also, to avoid massive store use which would result from using
994 string_cat() as it copies and extends strings, we do a preliminary pass to find
995 out exactly how much store will be needed. On "normal" messages this will be
996 pretty trivial.
997
998 Arguments:
999 name the name of the header, without the leading $header_ or $h_,
1000 or NULL if a concatenation of all headers is required
1001 exists_only TRUE if called from a def: test; don't need to build a string;
1002 just return a string that is not "" and not "0" if the header
1003 exists
1004 newsize return the size of memory block that was obtained; may be NULL
1005 if exists_only is TRUE
1006 want_raw TRUE if called for $rh_ or $rheader_ variables; no processing,
1007 other than concatenating, will be done on the header
1008 charset name of charset to translate MIME words to; used only if
1009 want_raw is false; if NULL, no translation is done (this is
1010 used for $bh_ and $bheader_)
1011
1012 Returns: NULL if the header does not exist, else a pointer to a new
1013 store block
1014 */
1015
1016 static uschar *
1017 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1018 uschar *charset)
1019 {
1020 BOOL found = name == NULL;
1021 int comma = 0;
1022 int len = found? 0 : Ustrlen(name);
1023 int i;
1024 uschar *yield = NULL;
1025 uschar *ptr = NULL;
1026
1027 /* Loop for two passes - saves code repetition */
1028
1029 for (i = 0; i < 2; i++)
1030 {
1031 int size = 0;
1032 header_line *h;
1033
1034 for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1035 {
1036 if (h->type != htype_old && h->text != NULL) /* NULL => Received: placeholder */
1037 {
1038 if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1039 {
1040 int ilen;
1041 uschar *t;
1042
1043 if (exists_only) return US"1"; /* don't need actual string */
1044 found = TRUE;
1045 t = h->text + len; /* text to insert */
1046 if (!want_raw) /* unless wanted raw, */
1047 while (isspace(*t)) t++; /* remove leading white space */
1048 ilen = h->slen - (t - h->text); /* length to insert */
1049
1050 /* Set comma = 1 if handling a single header and it's one of those
1051 that contains an address list, except when asked for raw headers. Only
1052 need to do this once. */
1053
1054 if (!want_raw && name != NULL && comma == 0 &&
1055 Ustrchr("BCFRST", h->type) != NULL)
1056 comma = 1;
1057
1058 /* First pass - compute total store needed; second pass - compute
1059 total store used, including this header. */
1060
1061 size += ilen + comma;
1062
1063 /* Second pass - concatentate the data, up to a maximum. Note that
1064 the loop stops when size hits the limit. */
1065
1066 if (i != 0)
1067 {
1068 if (size > header_insert_maxlen)
1069 {
1070 ilen -= size - header_insert_maxlen;
1071 comma = 0;
1072 }
1073 Ustrncpy(ptr, t, ilen);
1074 ptr += ilen;
1075 if (comma != 0 && ilen > 0)
1076 {
1077 ptr[-1] = ',';
1078 *ptr++ = '\n';
1079 }
1080 }
1081 }
1082 }
1083 }
1084
1085 /* At end of first pass, truncate size if necessary, and get the buffer
1086 to hold the data, returning the buffer size. */
1087
1088 if (i == 0)
1089 {
1090 if (!found) return NULL;
1091 if (size > header_insert_maxlen) size = header_insert_maxlen;
1092 *newsize = size + 1;
1093 ptr = yield = store_get(*newsize);
1094 }
1095 }
1096
1097 /* Remove a redundant added comma if present */
1098
1099 if (comma != 0 && ptr > yield) ptr -= 2;
1100
1101 /* That's all we do for raw header expansion. */
1102
1103 if (want_raw)
1104 {
1105 *ptr = 0;
1106 }
1107
1108 /* Otherwise, we remove trailing whitespace, including newlines. Then we do RFC
1109 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1110 function can return an error with decoded data if the charset translation
1111 fails. If decoding fails, it returns NULL. */
1112
1113 else
1114 {
1115 uschar *decoded, *error;
1116 while (ptr > yield && isspace(ptr[-1])) ptr--;
1117 *ptr = 0;
1118 decoded = rfc2047_decode2(yield, TRUE, charset, '?', NULL, newsize, &error);
1119 if (error != NULL)
1120 {
1121 DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1122 " input was: %s\n", error, yield);
1123 }
1124 if (decoded != NULL) yield = decoded;
1125 }
1126
1127 return yield;
1128 }
1129
1130
1131
1132
1133 /*************************************************
1134 * Find value of a variable *
1135 *************************************************/
1136
1137 /* The table of variables is kept in alphabetic order, so we can search it
1138 using a binary chop. The "choplen" variable is nothing to do with the binary
1139 chop.
1140
1141 Arguments:
1142 name the name of the variable being sought
1143 exists_only TRUE if this is a def: test; passed on to find_header()
1144 skipping TRUE => skip any processing evaluation; this is not the same as
1145 exists_only because def: may test for values that are first
1146 evaluated here
1147 newsize pointer to an int which is initially zero; if the answer is in
1148 a new memory buffer, *newsize is set to its size
1149
1150 Returns: NULL if the variable does not exist, or
1151 a pointer to the variable's contents, or
1152 something non-NULL if exists_only is TRUE
1153 */
1154
1155 static uschar *
1156 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1157 {
1158 int first = 0;
1159 int last = var_table_size;
1160
1161 while (last > first)
1162 {
1163 uschar *s, *domain;
1164 uschar **ss;
1165 int middle = (first + last)/2;
1166 int c = Ustrcmp(name, var_table[middle].name);
1167
1168 if (c > 0) { first = middle + 1; continue; }
1169 if (c < 0) { last = middle; continue; }
1170
1171 /* Found an existing variable. If in skipping state, the value isn't needed,
1172 and we want to avoid processing (such as looking up up the host name). */
1173
1174 if (skipping) return US"";
1175
1176 switch (var_table[middle].type)
1177 {
1178 case vtype_filter_int:
1179 if (!filter_running) return NULL;
1180 /* Fall through */
1181
1182 case vtype_int:
1183 sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1184 return var_buffer;
1185
1186 case vtype_ino:
1187 sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1188 return var_buffer;
1189
1190 case vtype_gid:
1191 sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1192 return var_buffer;
1193
1194 case vtype_uid:
1195 sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1196 return var_buffer;
1197
1198 case vtype_stringptr: /* Pointer to string */
1199 s = *((uschar **)(var_table[middle].value));
1200 return (s == NULL)? US"" : s;
1201
1202 case vtype_pid:
1203 sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1204 return var_buffer;
1205
1206 case vtype_load_avg:
1207 sprintf(CS var_buffer, "%d", os_getloadavg()); /* load_average */
1208 return var_buffer;
1209
1210 case vtype_host_lookup: /* Lookup if not done so */
1211 if (sender_host_name == NULL && sender_host_address != NULL &&
1212 !host_lookup_failed && host_name_lookup() == OK)
1213 host_build_sender_fullhost();
1214 return (sender_host_name == NULL)? US"" : sender_host_name;
1215
1216 case vtype_localpart: /* Get local part from address */
1217 s = *((uschar **)(var_table[middle].value));
1218 if (s == NULL) return US"";
1219 domain = Ustrrchr(s, '@');
1220 if (domain == NULL) return s;
1221 if (domain - s > sizeof(var_buffer) - 1)
1222 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than %d in "
1223 "string expansion", sizeof(var_buffer));
1224 Ustrncpy(var_buffer, s, domain - s);
1225 var_buffer[domain - s] = 0;
1226 return var_buffer;
1227
1228 case vtype_domain: /* Get domain from address */
1229 s = *((uschar **)(var_table[middle].value));
1230 if (s == NULL) return US"";
1231 domain = Ustrrchr(s, '@');
1232 return (domain == NULL)? US"" : domain + 1;
1233
1234 case vtype_msgheaders:
1235 return find_header(NULL, exists_only, newsize, FALSE, NULL);
1236
1237 case vtype_msgbody: /* Pointer to msgbody string */
1238 case vtype_msgbody_end: /* Ditto, the end of the msg */
1239 ss = (uschar **)(var_table[middle].value);
1240 if (*ss == NULL && deliver_datafile >= 0) /* Read body when needed */
1241 {
1242 uschar *body;
1243 int start_offset = SPOOL_DATA_START_OFFSET;
1244 int len = message_body_visible;
1245 if (len > message_size) len = message_size;
1246 *ss = body = store_malloc(len+1);
1247 body[0] = 0;
1248 if (var_table[middle].type == vtype_msgbody_end)
1249 {
1250 struct stat statbuf;
1251 if (fstat(deliver_datafile, &statbuf) == 0)
1252 {
1253 start_offset = statbuf.st_size - len;
1254 if (start_offset < SPOOL_DATA_START_OFFSET)
1255 start_offset = SPOOL_DATA_START_OFFSET;
1256 }
1257 }
1258 lseek(deliver_datafile, start_offset, SEEK_SET);
1259 len = read(deliver_datafile, body, len);
1260 if (len > 0)
1261 {
1262 body[len] = 0;
1263 while (len > 0)
1264 {
1265 if (body[--len] == '\n' || body[len] == 0) body[len] = ' ';
1266 }
1267 }
1268 }
1269 return (*ss == NULL)? US"" : *ss;
1270
1271 case vtype_todbsdin: /* BSD inbox time of day */
1272 return tod_stamp(tod_bsdin);
1273
1274 case vtype_tode: /* Unix epoch time of day */
1275 return tod_stamp(tod_epoch);
1276
1277 case vtype_todf: /* Full time of day */
1278 return tod_stamp(tod_full);
1279
1280 case vtype_todl: /* Log format time of day */
1281 return tod_stamp(tod_log_bare); /* (without timezone) */
1282
1283 case vtype_todzone: /* Time zone offset only */
1284 return tod_stamp(tod_zone);
1285
1286 case vtype_todzulu: /* Zulu time */
1287 return tod_stamp(tod_zulu);
1288
1289 case vtype_todlf: /* Log file datestamp tod */
1290 return tod_stamp(tod_log_datestamp);
1291
1292 case vtype_reply: /* Get reply address */
1293 s = find_header(US"reply-to:", exists_only, newsize, FALSE,
1294 headers_charset);
1295 if (s == NULL || *s == 0)
1296 s = find_header(US"from:", exists_only, newsize, FALSE, headers_charset);
1297 return (s == NULL)? US"" : s;
1298
1299 /* A recipients list is available only during system message filtering,
1300 during ACL processing after DATA, and while expanding pipe commands
1301 generated from a system filter, but not elsewhere. */
1302
1303 case vtype_recipients:
1304 if (!enable_dollar_recipients) return NULL; else
1305 {
1306 int size = 128;
1307 int ptr = 0;
1308 int i;
1309 s = store_get(size);
1310 for (i = 0; i < recipients_count; i++)
1311 {
1312 if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1313 s = string_cat(s, &size, &ptr, recipients_list[i].address,
1314 Ustrlen(recipients_list[i].address));
1315 }
1316 s[ptr] = 0; /* string_cat() leaves room */
1317 }
1318 return s;
1319
1320 case vtype_pspace:
1321 {
1322 int inodes;
1323 sprintf(CS var_buffer, "%d",
1324 receive_statvfs((BOOL)(var_table[middle].value), &inodes));
1325 }
1326 return var_buffer;
1327
1328 case vtype_pinodes:
1329 {
1330 int inodes;
1331 (void) receive_statvfs((BOOL)(var_table[middle].value), &inodes);
1332 sprintf(CS var_buffer, "%d", inodes);
1333 }
1334 return var_buffer;
1335 }
1336 }
1337
1338 return NULL; /* Unknown variable name */
1339 }
1340
1341
1342
1343
1344 /*************************************************
1345 * Read and expand substrings *
1346 *************************************************/
1347
1348 /* This function is called to read and expand argument substrings for various
1349 expansion items. Some have a minimum requirement that is less than the maximum;
1350 in these cases, the first non-present one is set to NULL.
1351
1352 Arguments:
1353 sub points to vector of pointers to set
1354 n maximum number of substrings
1355 m minimum required
1356 sptr points to current string pointer
1357 skipping the skipping flag
1358 check_end if TRUE, check for final '}'
1359 name name of item, for error message
1360
1361 Returns: 0 OK; string pointer updated
1362 1 curly bracketing error (too few arguments)
1363 2 too many arguments (only if check_end is set); message set
1364 3 other error (expansion failure)
1365 */
1366
1367 static int
1368 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1369 BOOL check_end, uschar *name)
1370 {
1371 int i;
1372 uschar *s = *sptr;
1373
1374 while (isspace(*s)) s++;
1375 for (i = 0; i < n; i++)
1376 {
1377 if (*s != '{')
1378 {
1379 if (i < m) return 1;
1380 sub[i] = NULL;
1381 break;
1382 }
1383 sub[i] = expand_string_internal(s+1, TRUE, &s, skipping);
1384 if (sub[i] == NULL) return 3;
1385 if (*s++ != '}') return 1;
1386 while (isspace(*s)) s++;
1387 }
1388 if (check_end && *s++ != '}')
1389 {
1390 if (s[-1] == '{')
1391 {
1392 expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1393 "(max is %d)", name, n);
1394 return 2;
1395 }
1396 return 1;
1397 }
1398
1399 *sptr = s;
1400 return 0;
1401 }
1402
1403
1404
1405
1406 /*************************************************
1407 * Read and evaluate a condition *
1408 *************************************************/
1409
1410 /*
1411 Arguments:
1412 s points to the start of the condition text
1413 yield points to a BOOL to hold the result of the condition test;
1414 if NULL, we are just reading through a condition that is
1415 part of an "or" combination to check syntax, or in a state
1416 where the answer isn't required
1417
1418 Returns: a pointer to the first character after the condition, or
1419 NULL after an error
1420 */
1421
1422 static uschar *
1423 eval_condition(uschar *s, BOOL *yield)
1424 {
1425 BOOL testfor = TRUE;
1426 BOOL tempcond, combined_cond;
1427 BOOL *subcondptr;
1428 int i, rc, cond_type, roffset;
1429 int num[2];
1430 struct stat statbuf;
1431 uschar name[256];
1432 uschar *sub[4];
1433
1434 const pcre *re;
1435 const uschar *rerror;
1436
1437 for (;;)
1438 {
1439 while (isspace(*s)) s++;
1440 if (*s == '!') { testfor = !testfor; s++; } else break;
1441 }
1442
1443 /* Numeric comparisons are symbolic */
1444
1445 if (*s == '=' || *s == '>' || *s == '<')
1446 {
1447 int p = 0;
1448 name[p++] = *s++;
1449 if (*s == '=')
1450 {
1451 name[p++] = '=';
1452 s++;
1453 }
1454 name[p] = 0;
1455 }
1456
1457 /* All other conditions are named */
1458
1459 else s = read_name(name, 256, s, US"_");
1460
1461 /* If we haven't read a name, it means some non-alpha character is first. */
1462
1463 if (name[0] == 0)
1464 {
1465 expand_string_message = string_sprintf("condition name expected, "
1466 "but found \"%.16s\"", s);
1467 return NULL;
1468 }
1469
1470 /* Find which condition we are dealing with, and switch on it */
1471
1472 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1473 switch(cond_type)
1474 {
1475 /* def: tests for a non-zero or non-NULL variable, or for an existing
1476 header */
1477
1478 case ECOND_DEF:
1479 if (*s != ':')
1480 {
1481 expand_string_message = US"\":\" expected after \"def\"";
1482 return NULL;
1483 }
1484
1485 s = read_name(name, 256, s+1, US"_");
1486
1487 /* Test for a header's existence */
1488
1489 if (Ustrncmp(name, "h_", 2) == 0 ||
1490 Ustrncmp(name, "rh_", 3) == 0 ||
1491 Ustrncmp(name, "bh_", 3) == 0 ||
1492 Ustrncmp(name, "header_", 7) == 0 ||
1493 Ustrncmp(name, "rheader_", 8) == 0 ||
1494 Ustrncmp(name, "bheader_", 8) == 0)
1495 {
1496 s = read_header_name(name, 256, s);
1497 if (yield != NULL) *yield =
1498 (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1499 }
1500
1501 /* Test for a variable's having a non-empty value. If yield == NULL we
1502 are in a skipping state, and don't care about the answer. */
1503
1504 else
1505 {
1506 uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1507 if (value == NULL)
1508 {
1509 expand_string_message = (name[0] == 0)?
1510 string_sprintf("variable name omitted after \"def:\"") :
1511 string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1512 return NULL;
1513 }
1514 if (yield != NULL)
1515 *yield = (value[0] != 0 && Ustrcmp(value, "0") != 0) == testfor;
1516 }
1517
1518 return s;
1519
1520
1521 /* first_delivery tests for first delivery attempt */
1522
1523 case ECOND_FIRST_DELIVERY:
1524 if (yield != NULL) *yield = deliver_firsttime == testfor;
1525 return s;
1526
1527
1528 /* queue_running tests for any process started by a queue runner */
1529
1530 case ECOND_QUEUE_RUNNING:
1531 if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
1532 return s;
1533
1534
1535 /* exists: tests for file existence
1536 isip: tests for any IP address
1537 isip4: tests for an IPv4 address
1538 isip6: tests for an IPv6 address
1539 pam: does PAM authentication
1540 radius: does RADIUS authentication
1541 ldapauth: does LDAP authentication
1542 pwcheck: does Cyrus SASL pwcheck authentication
1543 */
1544
1545 case ECOND_EXISTS:
1546 case ECOND_ISIP:
1547 case ECOND_ISIP4:
1548 case ECOND_ISIP6:
1549 case ECOND_PAM:
1550 case ECOND_RADIUS:
1551 case ECOND_LDAPAUTH:
1552 case ECOND_PWCHECK:
1553
1554 while (isspace(*s)) s++;
1555 if (*s != '{') goto COND_FAILED_CURLY_START;
1556
1557 sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1558 if (sub[0] == NULL) return NULL;
1559 if (*s++ != '}') goto COND_FAILED_CURLY_END;
1560
1561 if (yield == NULL) return s; /* No need to run the test if skipping */
1562
1563 switch(cond_type)
1564 {
1565 case ECOND_EXISTS:
1566 if ((expand_forbid & RDO_EXISTS) != 0)
1567 {
1568 expand_string_message = US"File existence tests are not permitted";
1569 return NULL;
1570 }
1571 *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
1572 break;
1573
1574 case ECOND_ISIP:
1575 case ECOND_ISIP4:
1576 case ECOND_ISIP6:
1577 rc = string_is_ip_address(sub[0], NULL);
1578 *yield = ((cond_type == ECOND_ISIP)? (rc > 0) :
1579 (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
1580 break;
1581
1582 /* Various authentication tests - all optionally compiled */
1583
1584 case ECOND_PAM:
1585 #ifdef SUPPORT_PAM
1586 rc = auth_call_pam(sub[0], &expand_string_message);
1587 goto END_AUTH;
1588 #else
1589 goto COND_FAILED_NOT_COMPILED;
1590 #endif /* SUPPORT_PAM */
1591
1592 case ECOND_RADIUS:
1593 #ifdef RADIUS_CONFIG_FILE
1594 rc = auth_call_radius(sub[0], &expand_string_message);
1595 goto END_AUTH;
1596 #else
1597 goto COND_FAILED_NOT_COMPILED;
1598 #endif /* RADIUS_CONFIG_FILE */
1599
1600 case ECOND_LDAPAUTH:
1601 #ifdef LOOKUP_LDAP
1602 {
1603 /* Just to keep the interface the same */
1604 BOOL do_cache;
1605 int old_pool = store_pool;
1606 store_pool = POOL_SEARCH;
1607 rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
1608 &expand_string_message, &do_cache);
1609 store_pool = old_pool;
1610 }
1611 goto END_AUTH;
1612 #else
1613 goto COND_FAILED_NOT_COMPILED;
1614 #endif /* LOOKUP_LDAP */
1615
1616 case ECOND_PWCHECK:
1617 #ifdef CYRUS_PWCHECK_SOCKET
1618 rc = auth_call_pwcheck(sub[0], &expand_string_message);
1619 goto END_AUTH;
1620 #else
1621 goto COND_FAILED_NOT_COMPILED;
1622 #endif /* CYRUS_PWCHECK_SOCKET */
1623
1624 #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
1625 defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
1626 END_AUTH:
1627 if (rc == ERROR || rc == DEFER) return NULL;
1628 *yield = (rc == OK) == testfor;
1629 #endif
1630 }
1631 return s;
1632
1633
1634 /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
1635
1636 ${if saslauthd {{username}{password}{service}{realm}} {yes}[no}}
1637
1638 However, the last two are optional. That is why the whole set is enclosed
1639 in their own set or braces. */
1640
1641 case ECOND_SASLAUTHD:
1642 #ifndef CYRUS_SASLAUTHD_SOCKET
1643 goto COND_FAILED_NOT_COMPILED;
1644 #else
1645 while (isspace(*s)) s++;
1646 if (*s++ != '{') goto COND_FAILED_CURLY_START;
1647 switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
1648 {
1649 case 1: expand_string_message = US"too few arguments or bracketing "
1650 "error for saslauthd";
1651 case 2:
1652 case 3: return NULL;
1653 }
1654 if (sub[2] == NULL) sub[3] = NULL; /* realm if no service */
1655 if (yield != NULL)
1656 {
1657 int rc;
1658 rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
1659 &expand_string_message);
1660 if (rc == ERROR || rc == DEFER) return NULL;
1661 *yield = (rc == OK) == testfor;
1662 }
1663 return s;
1664 #endif /* CYRUS_SASLAUTHD_SOCKET */
1665
1666
1667 /* symbolic operators for numeric and string comparison, and a number of
1668 other operators, all requiring two arguments.
1669
1670 match: does a regular expression match and sets up the numerical
1671 variables if it succeeds
1672 match_address: matches in an address list
1673 match_domain: matches in a domain list
1674 match_local_part: matches in a local part list
1675 crypteq: encrypts plaintext and compares against an encrypted text,
1676 using crypt(), crypt16(), MD5 or SHA-1
1677 */
1678
1679 case ECOND_MATCH:
1680 case ECOND_MATCH_ADDRESS:
1681 case ECOND_MATCH_DOMAIN:
1682 case ECOND_MATCH_LOCAL_PART:
1683 case ECOND_CRYPTEQ:
1684
1685 case ECOND_NUM_L: /* Numerical comparisons */
1686 case ECOND_NUM_LE:
1687 case ECOND_NUM_E:
1688 case ECOND_NUM_EE:
1689 case ECOND_NUM_G:
1690 case ECOND_NUM_GE:
1691
1692 case ECOND_STR_LT: /* String comparisons */
1693 case ECOND_STR_LTI:
1694 case ECOND_STR_LE:
1695 case ECOND_STR_LEI:
1696 case ECOND_STR_EQ:
1697 case ECOND_STR_EQI:
1698 case ECOND_STR_GT:
1699 case ECOND_STR_GTI:
1700 case ECOND_STR_GE:
1701 case ECOND_STR_GEI:
1702
1703 for (i = 0; i < 2; i++)
1704 {
1705 while (isspace(*s)) s++;
1706 if (*s != '{')
1707 {
1708 if (i == 0) goto COND_FAILED_CURLY_START;
1709 expand_string_message = string_sprintf("missing 2nd string in {} "
1710 "after \"%s\"", name);
1711 return NULL;
1712 }
1713 sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL);
1714 if (sub[i] == NULL) return NULL;
1715 if (*s++ != '}') goto COND_FAILED_CURLY_END;
1716
1717 /* Convert to numerical if required; we know that the names of all the
1718 conditions that compare numbers do not start with a letter. This just saves
1719 checking for them individually. */
1720
1721 if (!isalpha(name[0]))
1722 {
1723 uschar *endptr;
1724 num[i] = (int)Ustrtol((const uschar *)sub[i], &endptr, 10);
1725 if (tolower(*endptr) == 'k')
1726 {
1727 num[i] *= 1024;
1728 endptr++;
1729 }
1730 else if (tolower(*endptr) == 'm')
1731 {
1732 num[i] *= 1024*1024;
1733 endptr++;
1734 }
1735 while (isspace(*endptr)) endptr++;
1736 if (*endptr != 0)
1737 {
1738 expand_string_message = string_sprintf("\"%s\" is not a number",
1739 sub[i]);
1740 return NULL;
1741 }
1742 }
1743 }
1744
1745 /* Result not required */
1746
1747 if (yield == NULL) return s;
1748
1749 /* Do an appropriate comparison */
1750
1751 switch(cond_type)
1752 {
1753 case ECOND_NUM_E:
1754 case ECOND_NUM_EE:
1755 *yield = (num[0] == num[1]) == testfor;
1756 break;
1757
1758 case ECOND_NUM_G:
1759 *yield = (num[0] > num[1]) == testfor;
1760 break;
1761
1762 case ECOND_NUM_GE:
1763 *yield = (num[0] >= num[1]) == testfor;
1764 break;
1765
1766 case ECOND_NUM_L:
1767 *yield = (num[0] < num[1]) == testfor;
1768 break;
1769
1770 case ECOND_NUM_LE:
1771 *yield = (num[0] <= num[1]) == testfor;
1772 break;
1773
1774 case ECOND_STR_LT:
1775 *yield = (Ustrcmp(sub[0], sub[1]) < 0) == testfor;
1776 break;
1777
1778 case ECOND_STR_LTI:
1779 *yield = (strcmpic(sub[0], sub[1]) < 0) == testfor;
1780 break;
1781
1782 case ECOND_STR_LE:
1783 *yield = (Ustrcmp(sub[0], sub[1]) <= 0) == testfor;
1784 break;
1785
1786 case ECOND_STR_LEI:
1787 *yield = (strcmpic(sub[0], sub[1]) <= 0) == testfor;
1788 break;
1789
1790 case ECOND_STR_EQ:
1791 *yield = (Ustrcmp(sub[0], sub[1]) == 0) == testfor;
1792 break;
1793
1794 case ECOND_STR_EQI:
1795 *yield = (strcmpic(sub[0], sub[1]) == 0) == testfor;
1796 break;
1797
1798 case ECOND_STR_GT:
1799 *yield = (Ustrcmp(sub[0], sub[1]) > 0) == testfor;
1800 break;
1801
1802 case ECOND_STR_GTI:
1803 *yield = (strcmpic(sub[0], sub[1]) > 0) == testfor;
1804 break;
1805
1806 case ECOND_STR_GE:
1807 *yield = (Ustrcmp(sub[0], sub[1]) >= 0) == testfor;
1808 break;
1809
1810 case ECOND_STR_GEI:
1811 *yield = (strcmpic(sub[0], sub[1]) >= 0) == testfor;
1812 break;
1813
1814 case ECOND_MATCH: /* Regular expression match */
1815 re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
1816 NULL);
1817 if (re == NULL)
1818 {
1819 expand_string_message = string_sprintf("regular expression error in "
1820 "\"%s\": %s at offset %d", sub[1], rerror, roffset);
1821 return NULL;
1822 }
1823 *yield = regex_match_and_setup(re, sub[0], 0, -1) == testfor;
1824 break;
1825
1826 case ECOND_MATCH_ADDRESS: /* Match in an address list */
1827 rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
1828 goto MATCHED_SOMETHING;
1829
1830 case ECOND_MATCH_DOMAIN: /* Match in a domain list */
1831 rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
1832 MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
1833 goto MATCHED_SOMETHING;
1834
1835 case ECOND_MATCH_LOCAL_PART:
1836 rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
1837 MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
1838 /* Fall through */
1839
1840 MATCHED_SOMETHING:
1841 switch(rc)
1842 {
1843 case OK:
1844 *yield = testfor;
1845 break;
1846
1847 case FAIL:
1848 *yield = !testfor;
1849 break;
1850
1851 case DEFER:
1852 expand_string_message = string_sprintf("unable to complete match "
1853 "against \"%s\": %s", sub[1], search_error_message);
1854 return NULL;
1855 }
1856
1857 break;
1858
1859 /* Various "encrypted" comparisons. If the second string starts with
1860 "{" then an encryption type is given. Default to crypt() or crypt16()
1861 (build-time choice). */
1862
1863 case ECOND_CRYPTEQ:
1864 #ifndef SUPPORT_CRYPTEQ
1865 goto COND_FAILED_NOT_COMPILED;
1866 #else
1867 if (strncmpic(sub[1], US"{md5}", 5) == 0)
1868 {
1869 int sublen = Ustrlen(sub[1]+5);
1870 md5 base;
1871 uschar digest[16];
1872
1873 md5_start(&base);
1874 md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
1875
1876 /* If the length that we are comparing against is 24, the MD5 digest
1877 is expressed as a base64 string. This is the way LDAP does it. However,
1878 some other software uses a straightforward hex representation. We assume
1879 this if the length is 32. Other lengths fail. */
1880
1881 if (sublen == 24)
1882 {
1883 uschar *coded = auth_b64encode((uschar *)digest, 16);
1884 DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
1885 " subject=%s\n crypted=%s\n", coded, sub[1]+5);
1886 *yield = (Ustrcmp(coded, sub[1]+5) == 0) == testfor;
1887 }
1888 else if (sublen == 32)
1889 {
1890 int i;
1891 uschar coded[36];
1892 for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
1893 coded[32] = 0;
1894 DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
1895 " subject=%s\n crypted=%s\n", coded, sub[1]+5);
1896 *yield = (strcmpic(coded, sub[1]+5) == 0) == testfor;
1897 }
1898 else
1899 {
1900 DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
1901 "fail\n crypted=%s\n", sub[1]+5);
1902 *yield = !testfor;
1903 }
1904 }
1905
1906 else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
1907 {
1908 int sublen = Ustrlen(sub[1]+6);
1909 sha1 base;
1910 uschar digest[20];
1911
1912 sha1_start(&base);
1913 sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
1914
1915 /* If the length that we are comparing against is 28, assume the SHA1
1916 digest is expressed as a base64 string. If the length is 40, assume a
1917 straightforward hex representation. Other lengths fail. */
1918
1919 if (sublen == 28)
1920 {
1921 uschar *coded = auth_b64encode((uschar *)digest, 20);
1922 DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
1923 " subject=%s\n crypted=%s\n", coded, sub[1]+6);
1924 *yield = (Ustrcmp(coded, sub[1]+6) == 0) == testfor;
1925 }
1926 else if (sublen == 40)
1927 {
1928 int i;
1929 uschar coded[44];
1930 for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
1931 coded[40] = 0;
1932 DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
1933 " subject=%s\n crypted=%s\n", coded, sub[1]+6);
1934 *yield = (strcmpic(coded, sub[1]+6) == 0) == testfor;
1935 }
1936 else
1937 {
1938 DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
1939 "fail\n crypted=%s\n", sub[1]+6);
1940 *yield = !testfor;
1941 }
1942 }
1943
1944 else /* {crypt} or {crypt16} and non-{ at start */
1945 {
1946 int which = 0;
1947 uschar *coded;
1948
1949 if (strncmpic(sub[1], US"{crypt}", 7) == 0)
1950 {
1951 sub[1] += 7;
1952 which = 1;
1953 }
1954 else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
1955 {
1956 sub[1] += 9;
1957 which = 2;
1958 }
1959 else if (sub[1][0] == '{')
1960 {
1961 expand_string_message = string_sprintf("unknown encryption mechanism "
1962 "in \"%s\"", sub[1]);
1963 return NULL;
1964 }
1965
1966 switch(which)
1967 {
1968 case 0: coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
1969 case 1: coded = US crypt(CS sub[0], CS sub[1]); break;
1970 default: coded = US crypt16(CS sub[0], CS sub[1]); break;
1971 }
1972
1973 #define STR(s) # s
1974 #define XSTR(s) STR(s)
1975 DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
1976 " subject=%s\n crypted=%s\n",
1977 (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
1978 coded, sub[1]);
1979 #undef STR
1980 #undef XSTR
1981
1982 /* If the encrypted string contains fewer than two characters (for the
1983 salt), force failure. Otherwise we get false positives: with an empty
1984 string the yield of crypt() is an empty string! */
1985
1986 *yield = (Ustrlen(sub[1]) < 2)? !testfor :
1987 (Ustrcmp(coded, sub[1]) == 0) == testfor;
1988 }
1989 break;
1990 #endif /* SUPPORT_CRYPTEQ */
1991 } /* Switch for comparison conditions */
1992
1993 return s; /* End of comparison conditions */
1994
1995
1996 /* and/or: computes logical and/or of several conditions */
1997
1998 case ECOND_AND:
1999 case ECOND_OR:
2000 subcondptr = (yield == NULL)? NULL : &tempcond;
2001 combined_cond = (cond_type == ECOND_AND);
2002
2003 while (isspace(*s)) s++;
2004 if (*s++ != '{') goto COND_FAILED_CURLY_START;
2005
2006 for (;;)
2007 {
2008 while (isspace(*s)) s++;
2009 if (*s == '}') break;
2010 if (*s != '{')
2011 {
2012 expand_string_message = string_sprintf("each subcondition "
2013 "inside an \"%s{...}\" condition must be in its own {}", name);
2014 return NULL;
2015 }
2016
2017 s = eval_condition(s+1, subcondptr);
2018 if (s == NULL)
2019 {
2020 expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2021 expand_string_message, name);
2022 return NULL;
2023 }
2024 while (isspace(*s)) s++;
2025
2026 if (*s++ != '}')
2027 {
2028 expand_string_message = string_sprintf("missing } at end of condition "
2029 "inside \"%s\" group", name);
2030 return NULL;
2031 }
2032
2033 if (yield != NULL)
2034 {
2035 if (cond_type == ECOND_AND)
2036 {
2037 combined_cond &= tempcond;
2038 if (!combined_cond) subcondptr = NULL; /* once false, don't */
2039 } /* evaluate any more */
2040 else
2041 {
2042 combined_cond |= tempcond;
2043 if (combined_cond) subcondptr = NULL; /* once true, don't */
2044 } /* evaluate any more */
2045 }
2046 }
2047
2048 if (yield != NULL) *yield = (combined_cond == testfor);
2049 return ++s;
2050
2051
2052 /* Unknown condition */
2053
2054 default:
2055 expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2056 return NULL;
2057 } /* End switch on condition type */
2058
2059 /* Missing braces at start and end of data */
2060
2061 COND_FAILED_CURLY_START:
2062 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2063 return NULL;
2064
2065 COND_FAILED_CURLY_END:
2066 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2067 name);
2068 return NULL;
2069
2070 /* A condition requires code that is not compiled */
2071
2072 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2073 !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2074 !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2075 COND_FAILED_NOT_COMPILED:
2076 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2077 name);
2078 return NULL;
2079 #endif
2080 }
2081
2082
2083
2084
2085 /*************************************************
2086 * Save numerical variables *
2087 *************************************************/
2088
2089 /* This function is called from items such as "if" that want to preserve and
2090 restore the numbered variables.
2091
2092 Arguments:
2093 save_expand_string points to an array of pointers to set
2094 save_expand_nlength points to an array of ints for the lengths
2095
2096 Returns: the value of expand max to save
2097 */
2098
2099 static int
2100 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2101 {
2102 int i;
2103 for (i = 0; i <= expand_nmax; i++)
2104 {
2105 save_expand_nstring[i] = expand_nstring[i];
2106 save_expand_nlength[i] = expand_nlength[i];
2107 }
2108 return expand_nmax;
2109 }
2110
2111
2112
2113 /*************************************************
2114 * Restore numerical variables *
2115 *************************************************/
2116
2117 /* This function restored saved values of numerical strings.
2118
2119 Arguments:
2120 save_expand_nmax the number of strings to restore
2121 save_expand_string points to an array of pointers
2122 save_expand_nlength points to an array of ints
2123
2124 Returns: nothing
2125 */
2126
2127 static void
2128 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2129 int *save_expand_nlength)
2130 {
2131 int i;
2132 expand_nmax = save_expand_nmax;
2133 for (i = 0; i <= expand_nmax; i++)
2134 {
2135 expand_nstring[i] = save_expand_nstring[i];
2136 expand_nlength[i] = save_expand_nlength[i];
2137 }
2138 }
2139
2140
2141
2142
2143
2144 /*************************************************
2145 * Handle yes/no substrings *
2146 *************************************************/
2147
2148 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2149 alternative substrings that depend on whether or not the condition was true,
2150 or the lookup or extraction succeeded. The substrings always have to be
2151 expanded, to check their syntax, but "skipping" is set when the result is not
2152 needed - this avoids unnecessary nested lookups.
2153
2154 Arguments:
2155 skipping TRUE if we were skipping when this item was reached
2156 yes TRUE if the first string is to be used, else use the second
2157 save_lookup a value to put back into lookup_value before the 2nd expansion
2158 sptr points to the input string pointer
2159 yieldptr points to the output string pointer
2160 sizeptr points to the output string size
2161 ptrptr points to the output string pointer
2162 type "lookup" or "if" or "extract" or "run", for error message
2163
2164 Returns: 0 OK; lookup_value has been reset to save_lookup
2165 1 expansion failed
2166 2 expansion failed because of bracketing error
2167 */
2168
2169 static int
2170 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2171 uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2172 {
2173 int rc = 0;
2174 uschar *s = *sptr; /* Local value */
2175 uschar *sub1, *sub2;
2176
2177 /* If there are no following strings, we substitute the contents of $value for
2178 lookups and for extractions in the success case. For the ${if item, the string
2179 "true" is substituted. In the fail case, nothing is substituted for all three
2180 items. */
2181
2182 while (isspace(*s)) s++;
2183 if (*s == '}')
2184 {
2185 if (type[0] == 'i')
2186 {
2187 if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2188 }
2189 else
2190 {
2191 if (yes && lookup_value != NULL)
2192 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2193 Ustrlen(lookup_value));
2194 lookup_value = save_lookup;
2195 }
2196 s++;
2197 goto RETURN;
2198 }
2199
2200 /* Expand the first substring. Forced failures are noticed only if we actually
2201 want this string. Set skipping in the call in the fail case (this will always
2202 be the case if we were already skipping). */
2203
2204 sub1 = expand_string_internal(s+1, TRUE, &s, !yes);
2205 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2206 expand_string_forcedfail = FALSE;
2207 if (*s++ != '}') goto FAILED_CURLY;
2208
2209 /* If we want the first string, add it to the output */
2210
2211 if (yes)
2212 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2213
2214 /* If this is called from a lookup or an extract, we want to restore $value to
2215 what it was at the start of the item, so that it has this value during the
2216 second string expansion. For the call from "if" to this function, save_lookup
2217 is set to lookup_value, so that this statement does nothing. */
2218
2219 lookup_value = save_lookup;
2220
2221 /* There now follows either another substring, or "fail", or nothing. This
2222 time, forced failures are noticed only if we want the second string. We must
2223 set skipping in the nested call if we don't want this string, or if we were
2224 already skipping. */
2225
2226 while (isspace(*s)) s++;
2227 if (*s == '{')
2228 {
2229 sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping);
2230 if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2231 expand_string_forcedfail = FALSE;
2232 if (*s++ != '}') goto FAILED_CURLY;
2233
2234 /* If we want the second string, add it to the output */
2235
2236 if (!yes)
2237 *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2238 }
2239
2240 /* If there is no second string, but the word "fail" is present when the use of
2241 the second string is wanted, set a flag indicating it was a forced failure
2242 rather than a syntactic error. Swallow the terminating } in case this is nested
2243 inside another lookup or if or extract. */
2244
2245 else if (*s != '}')
2246 {
2247 uschar name[256];
2248 s = read_name(name, sizeof(name), s, US"_");
2249 if (Ustrcmp(name, "fail") == 0)
2250 {
2251 if (!yes && !skipping)
2252 {
2253 while (isspace(*s)) s++;
2254 if (*s++ != '}') goto FAILED_CURLY;
2255 expand_string_message =
2256 string_sprintf("\"%s\" failed and \"fail\" requested", type);
2257 expand_string_forcedfail = TRUE;
2258 goto FAILED;
2259 }
2260 }
2261 else
2262 {
2263 expand_string_message =
2264 string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
2265 goto FAILED;
2266 }
2267 }
2268
2269 /* All we have to do now is to check on the final closing brace. */
2270
2271 while (isspace(*s)) s++;
2272 if (*s++ == '}') goto RETURN;
2273
2274 /* Get here if there is a bracketing failure */
2275
2276 FAILED_CURLY:
2277 rc++;
2278
2279 /* Get here for other failures */
2280
2281 FAILED:
2282 rc++;
2283
2284 /* Update the input pointer value before returning */
2285
2286 RETURN:
2287 *sptr = s;
2288 return rc;
2289 }
2290
2291
2292
2293
2294
2295
2296 /*************************************************
2297 * Handle MD5 or SHA-1 computation for HMAC *
2298 *************************************************/
2299
2300 /* These are some wrapping functions that enable the HMAC code to be a bit
2301 cleaner. A good compiler will spot the tail recursion.
2302
2303 Arguments:
2304 type HMAC_MD5 or HMAC_SHA1
2305 remaining are as for the cryptographic hash functions
2306
2307 Returns: nothing
2308 */
2309
2310 static void
2311 chash_start(int type, void *base)
2312 {
2313 if (type == HMAC_MD5)
2314 md5_start((md5 *)base);
2315 else
2316 sha1_start((sha1 *)base);
2317 }
2318
2319 static void
2320 chash_mid(int type, void *base, uschar *string)
2321 {
2322 if (type == HMAC_MD5)
2323 md5_mid((md5 *)base, string);
2324 else
2325 sha1_mid((sha1 *)base, string);
2326 }
2327
2328 static void
2329 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
2330 {
2331 if (type == HMAC_MD5)
2332 md5_end((md5 *)base, string, length, digest);
2333 else
2334 sha1_end((sha1 *)base, string, length, digest);
2335 }
2336
2337
2338
2339
2340
2341 /*************************************************
2342 * Join a file onto the output string *
2343 *************************************************/
2344
2345 /* This is used for readfile and after a run expansion. It joins the contents
2346 of a file onto the output string, globally replacing newlines with a given
2347 string (optionally). The file is closed at the end.
2348
2349 Arguments:
2350 f the FILE
2351 yield pointer to the expandable string
2352 sizep pointer to the current size
2353 ptrp pointer to the current position
2354 eol newline replacement string, or NULL
2355
2356 Returns: new value of string pointer
2357 */
2358
2359 static uschar *
2360 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
2361 {
2362 int eollen;
2363 uschar buffer[1024];
2364
2365 eollen = (eol == NULL)? 0 : Ustrlen(eol);
2366
2367 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
2368 {
2369 int len = Ustrlen(buffer);
2370 if (eol != NULL && buffer[len-1] == '\n') len--;
2371 yield = string_cat(yield, sizep, ptrp, buffer, len);
2372 if (buffer[len] != 0)
2373 yield = string_cat(yield, sizep, ptrp, eol, eollen);
2374 }
2375
2376 if (yield != NULL) yield[*ptrp] = 0;
2377
2378 return yield;
2379 }
2380
2381
2382
2383
2384 /*************************************************
2385 * Evaluate numeric expression *
2386 *************************************************/
2387
2388 /* This is a set of mutually recursive functions that evaluate a simple
2389 arithmetic expression involving only + - * / and parentheses. The only one that
2390 is called from elsewhere is eval_expr, whose interface is:
2391
2392 Arguments:
2393 sptr pointer to the pointer to the string - gets updated
2394 decimal TRUE if numbers are to be assumed decimal
2395 error pointer to where to put an error message - must be NULL on input
2396 endket TRUE if ')' must terminate - FALSE for external call
2397
2398
2399 Returns: on success: the value of the expression, with *error still NULL
2400 on failure: an undefined value, with *error = a message
2401 */
2402
2403 static int eval_sumterm(uschar **, BOOL, uschar **);
2404
2405 static int
2406 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
2407 {
2408 uschar *s = *sptr;
2409 int x = eval_sumterm(&s, decimal, error);
2410 if (*error == NULL)
2411 {
2412 while (*s == '+' || *s == '-')
2413 {
2414 int op = *s++;
2415 int y = eval_sumterm(&s, decimal, error);
2416 if (*error != NULL) break;
2417 if (op == '+') x += y; else x -= y;
2418 }
2419 if (*error == NULL)
2420 {
2421 if (endket)
2422 {
2423 if (*s != ')')
2424 *error = US"expecting closing parenthesis";
2425 else
2426 while (isspace(*(++s)));
2427 }
2428 else if (*s != 0) *error = US"expecting + or -";
2429 }
2430 }
2431
2432 *sptr = s;
2433 return x;
2434 }
2435
2436 static int
2437 eval_term(uschar **sptr, BOOL decimal, uschar **error)
2438 {
2439 register int c;
2440 int n;
2441 uschar *s = *sptr;
2442 while (isspace(*s)) s++;
2443 c = *s;
2444 if (isdigit(c) || ((c == '-' || c == '+') && isdigit(s[1])))
2445 {
2446 int count;
2447 (void)sscanf(CS s, (decimal? "%d%n" : "%i%n"), &n, &count);
2448 s += count;
2449 if (tolower(*s) == 'k') { n *= 1024; s++; }
2450 else if (tolower(*s) == 'm') { n *= 1024*1024; s++; }
2451 while (isspace (*s)) s++;
2452 }
2453 else if (c == '(')
2454 {
2455 s++;
2456 n = eval_expr(&s, decimal, error, 1);
2457 }
2458 else
2459 {
2460 *error = US"expecting number or opening parenthesis";
2461 n = 0;
2462 }
2463 *sptr = s;
2464 return n;
2465 }
2466
2467 static int eval_sumterm(uschar **sptr, BOOL decimal, uschar **error)
2468 {
2469 uschar *s = *sptr;
2470 int x = eval_term(&s, decimal, error);
2471 if (*error == NULL)
2472 {
2473 while (*s == '*' || *s == '/')
2474 {
2475 int op = *s++;
2476 int y = eval_term(&s, decimal, error);
2477 if (*error != NULL) break;
2478 if (op == '*') x *= y; else x /= y;
2479 }
2480 }
2481 *sptr = s;
2482 return x;
2483 }
2484
2485
2486
2487
2488 /*************************************************
2489 * Expand string *
2490 *************************************************/
2491
2492 /* Returns either an unchanged string, or the expanded string in stacking pool
2493 store. Interpreted sequences are:
2494
2495 \... normal escaping rules
2496 $name substitutes the variable
2497 ${name} ditto
2498 ${op:string} operates on the expanded string value
2499 ${item{arg1}{arg2}...} expands the args and then does the business
2500 some literal args are not enclosed in {}
2501
2502 There are now far too many operators and item types to make it worth listing
2503 them here in detail any more.
2504
2505 We use an internal routine recursively to handle embedded substrings. The
2506 external function follows. The yield is NULL if the expansion failed, and there
2507 are two cases: if something collapsed syntactically, or if "fail" was given
2508 as the action on a lookup failure. These can be distinguised by looking at the
2509 variable expand_string_forcedfail, which is TRUE in the latter case.
2510
2511 The skipping flag is set true when expanding a substring that isn't actually
2512 going to be used (after "if" or "lookup") and it prevents lookups from
2513 happening lower down.
2514
2515 Store usage: At start, a store block of the length of the input plus 64
2516 is obtained. This is expanded as necessary by string_cat(), which might have to
2517 get a new block, or might be able to expand the original. At the end of the
2518 function we can release any store above that portion of the yield block that
2519 was actually used. In many cases this will be optimal.
2520
2521 However: if the first item in the expansion is a variable name or header name,
2522 we reset the store before processing it; if the result is in fresh store, we
2523 use that without copying. This is helpful for expanding strings like
2524 $message_headers which can get very long.
2525
2526 Arguments:
2527 string the string to be expanded
2528 ket_ends true if expansion is to stop at }
2529 left if not NULL, a pointer to the first character after the
2530 expansion is placed here (typically used with ket_ends)
2531 skipping TRUE for recursive calls when the value isn't actually going
2532 to be used (to allow for optimisation)
2533
2534 Returns: NULL if expansion fails:
2535 expand_string_forcedfail is set TRUE if failure was forced
2536 expand_string_message contains a textual error message
2537 a pointer to the expanded string on success
2538 */
2539
2540 static uschar *
2541 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
2542 BOOL skipping)
2543 {
2544 int ptr = 0;
2545 int size = Ustrlen(string)+ 64;
2546 int item_type;
2547 uschar *yield = store_get(size);
2548 uschar *s = string;
2549 uschar *save_expand_nstring[EXPAND_MAXN+1];
2550 int save_expand_nlength[EXPAND_MAXN+1];
2551
2552 expand_string_forcedfail = FALSE;
2553 expand_string_message = US"";
2554
2555 while (*s != 0)
2556 {
2557 uschar *value;
2558 uschar name[256];
2559
2560 /* \ escapes the next character, which must exist, or else
2561 the expansion fails. There's a special escape, \N, which causes
2562 copying of the subject verbatim up to the next \N. Otherwise,
2563 the escapes are the standard set. */
2564
2565 if (*s == '\\')
2566 {
2567 if (s[1] == 0)
2568 {
2569 expand_string_message = US"\\ at end of string";
2570 goto EXPAND_FAILED;
2571 }
2572
2573 if (s[1] == 'N')
2574 {
2575 uschar *t = s + 2;
2576 for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
2577 yield = string_cat(yield, &size, &ptr, t, s - t);
2578 if (*s != 0) s += 2;
2579 }
2580
2581 else
2582 {
2583 uschar ch[1];
2584 ch[0] = string_interpret_escape(&s);
2585 s++;
2586 yield = string_cat(yield, &size, &ptr, ch, 1);
2587 }
2588
2589 continue;
2590 }
2591
2592 /* Anything other than $ is just copied verbatim, unless we are
2593 looking for a terminating } character. */
2594
2595 if (ket_ends && *s == '}') break;
2596
2597 if (*s != '$')
2598 {
2599 yield = string_cat(yield, &size, &ptr, s++, 1);
2600 continue;
2601 }
2602
2603 /* No { after the $ - must be a plain name or a number for string
2604 match variable. There has to be a fudge for variables that are the
2605 names of header fields preceded by "$header_" because header field
2606 names can contain any printing characters except space and colon.
2607 For those that don't like typing this much, "$h_" is a synonym for
2608 "$header_". A non-existent header yields a NULL value; nothing is
2609 inserted. */
2610
2611 if (isalpha((*(++s))))
2612 {
2613 int len;
2614 int newsize = 0;
2615
2616 s = read_name(name, sizeof(name), s, US"_");
2617
2618 /* If this is the first thing to be expanded, release the pre-allocated
2619 buffer. */
2620
2621 if (ptr == 0 && yield != NULL)
2622 {
2623 store_reset(yield);
2624 yield = NULL;
2625 size = 0;
2626 }
2627
2628 /* Header */
2629
2630 if (Ustrncmp(name, "h_", 2) == 0 ||
2631 Ustrncmp(name, "rh_", 3) == 0 ||
2632 Ustrncmp(name, "bh_", 3) == 0 ||
2633 Ustrncmp(name, "header_", 7) == 0 ||
2634 Ustrncmp(name, "rheader_", 8) == 0 ||
2635 Ustrncmp(name, "bheader_", 8) == 0)
2636 {
2637 BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
2638 uschar *charset = (name[0] == 'b')? NULL : headers_charset;
2639 s = read_header_name(name, sizeof(name), s);
2640 value = find_header(name, FALSE, &newsize, want_raw, charset);
2641
2642 /* If we didn't find the header, and the header contains a closing brace
2643 characters, this may be a user error where the terminating colon
2644 has been omitted. Set a flag to adjust the error message in this case.
2645 But there is no error here - nothing gets inserted. */
2646
2647 if (value == NULL)
2648 {
2649 if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2650 continue;
2651 }
2652 }
2653
2654 /* Variable */
2655
2656 else
2657 {
2658 value = find_variable(name, FALSE, skipping, &newsize);
2659 if (value == NULL)
2660 {
2661 expand_string_message =
2662 string_sprintf("unknown variable name \"%s\"", name);
2663 goto EXPAND_FAILED;
2664 }
2665 }
2666
2667 /* If the data is known to be in a new buffer, newsize will be set to the
2668 size of that buffer. If this is the first thing in an expansion string,
2669 yield will be NULL; just point it at the new store instead of copying. Many
2670 expansion strings contain just one reference, so this is a useful
2671 optimization, especially for humungous headers. */
2672
2673 len = Ustrlen(value);
2674 if (yield == NULL && newsize != 0)
2675 {
2676 yield = value;
2677 size = newsize;
2678 ptr = len;
2679 }
2680 else yield = string_cat(yield, &size, &ptr, value, len);
2681
2682 continue;
2683 }
2684
2685 if (isdigit(*s))
2686 {
2687 int n;
2688 s = read_number(&n, s);
2689 if (n >= 0 && n <= expand_nmax)
2690 yield = string_cat(yield, &size, &ptr, expand_nstring[n],
2691 expand_nlength[n]);
2692 continue;
2693 }
2694
2695 /* Otherwise, if there's no '{' after $ it's an error. */
2696
2697 if (*s != '{')
2698 {
2699 expand_string_message = US"$ not followed by letter, digit, or {";
2700 goto EXPAND_FAILED;
2701 }
2702
2703 /* After { there can be various things, but they all start with
2704 an initial word, except for a number for a string match variable. */
2705
2706 if (isdigit((*(++s))))
2707 {
2708 int n;
2709 s = read_number(&n, s);
2710 if (*s++ != '}')
2711 {
2712 expand_string_message = US"} expected after number";
2713 goto EXPAND_FAILED;
2714 }
2715 if (n >= 0 && n <= expand_nmax)
2716 yield = string_cat(yield, &size, &ptr, expand_nstring[n],
2717 expand_nlength[n]);
2718 continue;
2719 }
2720
2721 if (!isalpha(*s))
2722 {
2723 expand_string_message = US"letter or digit expected after ${";
2724 goto EXPAND_FAILED;
2725 }
2726
2727 /* Allow "-" in names to cater for substrings with negative
2728 arguments. Since we are checking for known names after { this is
2729 OK. */
2730
2731 s = read_name(name, sizeof(name), s, US"_-");
2732 item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
2733
2734 switch(item_type)
2735 {
2736 /* Handle conditionals - preserve the values of the numerical expansion
2737 variables in case they get changed by a regular expression match in the
2738 condition. If not, they retain their external settings. At the end
2739 of this "if" section, they get restored to their previous values. */
2740
2741 case EITEM_IF:
2742 {
2743 BOOL cond = FALSE;
2744 uschar *next_s;
2745 int save_expand_nmax =
2746 save_expand_strings(save_expand_nstring, save_expand_nlength);
2747
2748 while (isspace(*s)) s++;
2749 next_s = eval_condition(s, skipping? NULL : &cond);
2750 if (next_s == NULL) goto EXPAND_FAILED; /* message already set */
2751
2752 DEBUG(D_expand)
2753 debug_printf("condition: %.*s\n result: %s\n", (int)(next_s - s), s,
2754 cond? "true" : "false");
2755
2756 s = next_s;
2757
2758 /* The handling of "yes" and "no" result strings is now in a separate
2759 function that is also used by ${lookup} and ${extract} and ${run}. */
2760
2761 switch(process_yesno(
2762 skipping, /* were previously skipping */
2763 cond, /* success/failure indicator */
2764 lookup_value, /* value to reset for string2 */
2765 &s, /* input pointer */
2766 &yield, /* output pointer */
2767 &size, /* output size */
2768 &ptr, /* output current point */
2769 US"if")) /* condition type */
2770 {
2771 case 1: goto EXPAND_FAILED; /* when all is well, the */
2772 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
2773 }
2774
2775 /* Restore external setting of expansion variables for continuation
2776 at this level. */
2777
2778 restore_expand_strings(save_expand_nmax, save_expand_nstring,
2779 save_expand_nlength);
2780 continue;
2781 }
2782
2783 /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
2784 expanding an internal string that isn't actually going to be used. All we
2785 need to do is check the syntax, so don't do a lookup at all. Preserve the
2786 values of the numerical expansion variables in case they get changed by a
2787 partial lookup. If not, they retain their external settings. At the end
2788 of this "lookup" section, they get restored to their previous values. */
2789
2790 case EITEM_LOOKUP:
2791 {
2792 int stype, partial, affixlen, starflags;
2793 int expand_setup = 0;
2794 int nameptr = 0;
2795 uschar *key, *filename, *affix;
2796 uschar *save_lookup_value = lookup_value;
2797 int save_expand_nmax =
2798 save_expand_strings(save_expand_nstring, save_expand_nlength);
2799
2800 if ((expand_forbid & RDO_LOOKUP) != 0)
2801 {
2802 expand_string_message = US"lookup expansions are not permitted";
2803 goto EXPAND_FAILED;
2804 }
2805
2806 /* Get the key we are to look up for single-key+file style lookups.
2807 Otherwise set the key NULL pro-tem. */
2808
2809 while (isspace(*s)) s++;
2810 if (*s == '{')
2811 {
2812 key = expand_string_internal(s+1, TRUE, &s, skipping);
2813 if (key == NULL) goto EXPAND_FAILED;
2814 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
2815 while (isspace(*s)) s++;
2816 }
2817 else key = NULL;
2818
2819 /* Find out the type of database */
2820
2821 if (!isalpha(*s))
2822 {
2823 expand_string_message = US"missing lookup type";
2824 goto EXPAND_FAILED;
2825 }
2826
2827 /* The type is a string that may contain special characters of various
2828 kinds. Allow everything except space or { to appear; the actual content
2829 is checked by search_findtype_partial. */
2830
2831 while (*s != 0 && *s != '{' && !isspace(*s))
2832 {
2833 if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
2834 s++;
2835 }
2836 name[nameptr] = 0;
2837 while (isspace(*s)) s++;
2838
2839 /* Now check for the individual search type and any partial or default
2840 options. Only those types that are actually in the binary are valid. */
2841
2842 stype = search_findtype_partial(name, &partial, &affix, &affixlen,
2843 &starflags);
2844 if (stype < 0)
2845 {
2846 expand_string_message = search_error_message;
2847 goto EXPAND_FAILED;
2848 }
2849
2850 /* Check that a key was provided for those lookup types that need it,
2851 and was not supplied for those that use the query style. */
2852
2853 if (!mac_islookup(stype, lookup_querystyle))
2854 {
2855 if (key == NULL)
2856 {
2857 expand_string_message = string_sprintf("missing {key} for single-"
2858 "key \"%s\" lookup", name);
2859 goto EXPAND_FAILED;
2860 }
2861 }
2862 else
2863 {
2864 if (key != NULL)
2865 {
2866 expand_string_message = string_sprintf("a single key was given for "
2867 "lookup type \"%s\", which is not a single-key lookup type", name);
2868 goto EXPAND_FAILED;
2869 }
2870 }
2871
2872 /* Get the next string in brackets and expand it. It is the file name for
2873 single-key+file lookups, and the whole query otherwise. */
2874
2875 if (*s != '{') goto EXPAND_FAILED_CURLY;
2876 filename = expand_string_internal(s+1, TRUE, &s, skipping);
2877 if (filename == NULL) goto EXPAND_FAILED;
2878 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
2879 while (isspace(*s)) s++;
2880
2881 /* If this isn't a single-key+file lookup, re-arrange the variables
2882 to be appropriate for the search_ functions. */
2883
2884 if (key == NULL)
2885 {
2886 key = filename;
2887 filename = NULL;
2888 }
2889
2890 /* If skipping, don't do the next bit - just lookup_value == NULL, as if
2891 the entry was not found. Note that there is no search_close() function.
2892 Files are left open in case of re-use. At suitable places in higher logic,
2893 search_tidyup() is called to tidy all open files. This can save opening
2894 the same file several times. However, files may also get closed when
2895 others are opened, if too many are open at once. The rule is that a
2896 handle should not be used after a second search_open().
2897
2898 Request that a partial search sets up $1 and maybe $2 by passing
2899 expand_setup containing zero. If its value changes, reset expand_nmax,
2900 since new variables will have been set. Note that at the end of this
2901 "lookup" section, the old numeric variables are restored. */
2902
2903 if (skipping)
2904 lookup_value = NULL;
2905 else
2906 {
2907 void *handle = search_open(filename, stype, 0, NULL, NULL);
2908 if (handle == NULL)
2909 {
2910 expand_string_message = search_error_message;
2911 goto EXPAND_FAILED;
2912 }
2913 lookup_value = search_find(handle, filename, key, partial, affix,
2914 affixlen, starflags, &expand_setup);
2915 if (search_find_defer)
2916 {
2917 expand_string_message =
2918 string_sprintf("lookup of \"%s\" gave DEFER: %s", key,
2919 search_error_message);
2920 goto EXPAND_FAILED;
2921 }
2922 if (expand_setup > 0) expand_nmax = expand_setup;
2923 }
2924
2925 /* The handling of "yes" and "no" result strings is now in a separate
2926 function that is also used by ${if} and ${extract}. */
2927
2928 switch(process_yesno(
2929 skipping, /* were previously skipping */
2930 lookup_value != NULL, /* success/failure indicator */
2931 save_lookup_value, /* value to reset for string2 */
2932 &s, /* input pointer */
2933 &yield, /* output pointer */
2934 &size, /* output size */
2935 &ptr, /* output current point */
2936 US"lookup")) /* condition type */
2937 {
2938 case 1: goto EXPAND_FAILED; /* when all is well, the */
2939 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
2940 }
2941
2942 /* Restore external setting of expansion variables for carrying on
2943 at this level, and continue. */
2944
2945 restore_expand_strings(save_expand_nmax, save_expand_nstring,
2946 save_expand_nlength);
2947 continue;
2948 }
2949
2950 /* If Perl support is configured, handle calling embedded perl subroutines,
2951 unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
2952 or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
2953 arguments (defined below). */
2954
2955 #ifdef EXIM_PERL
2956 #define EXIM_PERL_MAX_ARGS 8
2957
2958 case EITEM_PERL:
2959 {
2960 uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
2961 uschar *new_yield;
2962
2963 if ((expand_forbid & RDO_PERL) != 0)
2964 {
2965 expand_string_message = US"Perl calls are not permitted";
2966 goto EXPAND_FAILED;
2967 }
2968
2969 switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
2970 US"perl"))
2971 {
2972 case 1: goto EXPAND_FAILED_CURLY;
2973 case 2:
2974 case 3: goto EXPAND_FAILED;
2975 }
2976
2977 /* If skipping, we don't actually do anything */
2978
2979 if (skipping) continue;
2980
2981 /* Start the interpreter if necessary */
2982
2983 if (!opt_perl_started)
2984 {
2985 uschar *initerror;
2986 if (opt_perl_startup == NULL)
2987 {
2988 expand_string_message = US"A setting of perl_startup is needed when "
2989 "using the Perl interpreter";
2990 goto EXPAND_FAILED;
2991 }
2992 DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
2993 initerror = init_perl(opt_perl_startup);
2994 if (initerror != NULL)
2995 {
2996 expand_string_message =
2997 string_sprintf("error in perl_startup code: %s\n", initerror);
2998 goto EXPAND_FAILED;
2999 }
3000 opt_perl_started = TRUE;
3001 }
3002
3003 /* Call the function */
3004
3005 sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
3006 new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
3007 sub_arg[0], sub_arg + 1);
3008
3009 /* NULL yield indicates failure; if the message pointer has been set to
3010 NULL, the yield was undef, indicating a forced failure. Otherwise the
3011 message will indicate some kind of Perl error. */
3012
3013 if (new_yield == NULL)
3014 {
3015 if (expand_string_message == NULL)
3016 {
3017 expand_string_message =
3018 string_sprintf("Perl subroutine \"%s\" returned undef to force "
3019 "failure", sub_arg[0]);
3020 expand_string_forcedfail = TRUE;
3021 }
3022 goto EXPAND_FAILED;
3023 }
3024
3025 /* Yield succeeded. Ensure forcedfail is unset, just in case it got
3026 set during a callback from Perl. */
3027
3028 expand_string_forcedfail = FALSE;
3029 yield = new_yield;
3030 continue;
3031 }
3032 #endif /* EXIM_PERL */
3033
3034 /* Handle "readfile" to insert an entire file */
3035
3036 case EITEM_READFILE:
3037 {
3038 FILE *f;
3039 uschar *sub_arg[2];
3040
3041 if ((expand_forbid & RDO_READFILE) != 0)
3042 {
3043 expand_string_message = US"file insertions are not permitted";
3044 goto EXPAND_FAILED;
3045 }
3046
3047 switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
3048 {
3049 case 1: goto EXPAND_FAILED_CURLY;
3050 case 2:
3051 case 3: goto EXPAND_FAILED;
3052 }
3053
3054 /* If skipping, we don't actually do anything */
3055
3056 if (skipping) continue;
3057
3058 /* Open the file and read it */
3059
3060 f = Ufopen(sub_arg[0], "rb");
3061 if (f == NULL)
3062 {
3063 expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
3064 goto EXPAND_FAILED;
3065 }
3066
3067 yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
3068 fclose(f);
3069 continue;
3070 }
3071
3072 /* Handle "readsocket" to insert data from a Unix domain socket */
3073
3074 case EITEM_READSOCK:
3075 {
3076 int fd;
3077 int timeout = 5;
3078 int save_ptr = ptr;
3079 FILE *f;
3080 struct sockaddr_un sockun; /* don't call this "sun" ! */
3081 uschar *arg;
3082 uschar *sub_arg[4];
3083
3084 if ((expand_forbid & RDO_READSOCK) != 0)
3085 {
3086 expand_string_message = US"socket insertions are not permitted";
3087 goto EXPAND_FAILED;
3088 }
3089
3090 /* Read up to 4 arguments, but don't do the end of item check afterwards,
3091 because there may be a string for expansion on failure. */
3092
3093 switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
3094 {
3095 case 1: goto EXPAND_FAILED_CURLY;
3096 case 2: /* Won't occur: no end check */
3097 case 3: goto EXPAND_FAILED;
3098 }
3099
3100 /* Sort out timeout, if given */
3101
3102 if (sub_arg[2] != NULL)
3103 {
3104 timeout = readconf_readtime(sub_arg[2], 0, FALSE);
3105 if (timeout < 0)
3106 {
3107 expand_string_message = string_sprintf("bad time value %s",
3108 sub_arg[2]);
3109 goto EXPAND_FAILED;
3110 }
3111 }
3112 else sub_arg[3] = NULL; /* No eol if no timeout */
3113
3114 /* If skipping, we don't actually do anything */
3115
3116 if (!skipping)
3117 {
3118 /* Make a connection to the socket */
3119
3120 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
3121 {
3122 expand_string_message = string_sprintf("failed to create socket: %s",
3123 strerror(errno));
3124 goto SOCK_FAIL;
3125 }
3126
3127 sockun.sun_family = AF_UNIX;
3128 sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
3129 sub_arg[0]);
3130 if(connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun)) == -1)
3131 {
3132 expand_string_message = string_sprintf("failed to connect to socket "
3133 "%s: %s", sub_arg[0], strerror(errno));
3134 goto SOCK_FAIL;
3135 }
3136 DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
3137
3138 /* Write the request string, if not empty */
3139
3140 if (sub_arg[1][0] != 0)
3141 {
3142 int len = Ustrlen(sub_arg[1]);
3143 DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
3144 sub_arg[1]);
3145 if (write(fd, sub_arg[1], len) != len)
3146 {
3147 expand_string_message = string_sprintf("request write to socket "
3148 "failed: %s", strerror(errno));
3149 goto SOCK_FAIL;
3150 }
3151 }
3152
3153 /* Now we need to read from the socket, under a timeout. The function
3154 that reads a file can be used. */
3155
3156 f = fdopen(fd, "rb");
3157 sigalrm_seen = FALSE;
3158 alarm(timeout);
3159 yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
3160 alarm(0);
3161 fclose(f);
3162
3163 /* After a timeout, we restore the pointer in the result, that is,
3164 make sure we add nothing from the socket. */
3165
3166 if (sigalrm_seen)
3167 {
3168 ptr = save_ptr;
3169 expand_string_message = US"socket read timed out";
3170 goto SOCK_FAIL;
3171 }
3172 }
3173
3174 /* The whole thing has worked (or we were skipping). If there is a
3175 failure string following, we need to skip it. */
3176
3177 if (*s == '{')
3178 {
3179 if (expand_string_internal(s+1, TRUE, &s, TRUE) == NULL)
3180 goto EXPAND_FAILED;
3181 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3182 while (isspace(*s)) s++;
3183 }
3184 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3185 continue;
3186
3187 /* Come here on failure to create socket, connect socket, write to the
3188 socket, or timeout on reading. If another substring follows, expand and
3189 use it. Otherwise, those conditions give expand errors. */
3190
3191 SOCK_FAIL:
3192 if (*s != '{') goto EXPAND_FAILED;
3193 DEBUG(D_any) debug_printf("%s\n", expand_string_message);
3194 arg = expand_string_internal(s+1, TRUE, &s, FALSE);
3195 if (arg == NULL) goto EXPAND_FAILED;
3196 yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
3197 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3198 while (isspace(*s)) s++;
3199 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3200 continue;
3201 }
3202
3203 /* Handle "run" to execute a program. */
3204
3205 case EITEM_RUN:
3206 {
3207 FILE *f;
3208 uschar *old_lookup_value = NULL;
3209 uschar *arg;
3210 uschar **argv;
3211 pid_t pid;
3212 int fd_in, fd_out;
3213 int lsize = 0;
3214 int lptr = 0;
3215
3216 if ((expand_forbid & RDO_RUN) != 0)
3217 {
3218 expand_string_message = US"running a command is not permitted";
3219 goto EXPAND_FAILED;
3220 }
3221
3222 while (isspace(*s)) s++;
3223 if (*s != '{') goto EXPAND_FAILED_CURLY;
3224 arg = expand_string_internal(s+1, TRUE, &s, skipping);
3225 if (arg == NULL) goto EXPAND_FAILED;
3226 while (isspace(*s)) s++;
3227 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3228
3229 if (skipping) /* Just pretend it worked when we're skipping */
3230 {
3231 runrc = 0;
3232 }
3233 else
3234 {
3235 if (!transport_set_up_command(&argv, /* anchor for arg list */
3236 arg, /* raw command */
3237 FALSE, /* don't expand the arguments */
3238 0, /* not relevant when... */
3239 NULL, /* no transporting address */
3240 US"${run} expansion", /* for error messages */
3241 &expand_string_message)) /* where to put error message */
3242 {
3243 goto EXPAND_FAILED;
3244 }
3245
3246 /* Create the child process, making it a group leader. */
3247
3248 pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
3249
3250 if (pid < 0)
3251 {
3252 expand_string_message =
3253 string_sprintf("couldn't create child process: %s", strerror(errno));
3254 goto EXPAND_FAILED;
3255 }
3256
3257 /* Nothing is written to the standard input. */
3258
3259 close(fd_in);
3260
3261 /* Wait for the process to finish, applying the timeout, and inspect its
3262 return code for serious disasters. Simple non-zero returns are passed on.
3263 */
3264
3265 if ((runrc = child_close(pid, 60)) < 0)
3266 {
3267 if (runrc == -256)
3268 {
3269 expand_string_message = string_sprintf("command timed out");
3270 killpg(pid, SIGKILL); /* Kill the whole process group */
3271 }
3272
3273 else if (runrc == -257)
3274 expand_string_message = string_sprintf("wait() failed: %s",
3275 strerror(errno));
3276
3277 else
3278 expand_string_message = string_sprintf("command killed by signal %d",
3279 -runrc);
3280
3281 goto EXPAND_FAILED;
3282 }
3283
3284 /* Read the pipe to get the command's output into $value (which is kept
3285 in lookup_value). */
3286
3287 f = fdopen(fd_out, "rb");
3288 old_lookup_value = lookup_value;
3289 lookup_value = NULL;
3290 lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
3291 fclose(f);
3292 }
3293
3294 /* Process the yes/no strings */
3295
3296 switch(process_yesno(
3297 skipping, /* were previously skipping */
3298 runrc == 0, /* success/failure indicator */
3299 old_lookup_value, /* value to reset for string2 */
3300 &s, /* input pointer */
3301 &yield, /* output pointer */
3302 &size, /* output size */
3303 &ptr, /* output current point */
3304 US"run")) /* condition type */
3305 {
3306 case 1: goto EXPAND_FAILED; /* when all is well, the */
3307 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
3308 }
3309
3310 continue;
3311 }
3312
3313 /* Handle character translation for "tr" */
3314
3315 case EITEM_TR:
3316 {
3317 int oldptr = ptr;
3318 int o2m;
3319 uschar *sub[3];
3320
3321 switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
3322 {
3323 case 1: goto EXPAND_FAILED_CURLY;
3324 case 2:
3325 case 3: goto EXPAND_FAILED;
3326 }
3327
3328 yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
3329 o2m = Ustrlen(sub[2]) - 1;
3330
3331 if (o2m >= 0) for (; oldptr < ptr; oldptr++)
3332 {
3333 uschar *m = Ustrrchr(sub[1], yield[oldptr]);
3334 if (m != NULL)
3335 {
3336 int o = m - sub[1];
3337 yield[oldptr] = sub[2][(o < o2m)? o : o2m];
3338 }
3339 }
3340
3341 continue;
3342 }
3343
3344 /* Handle "hash", "length", "nhash", and "substr" when they are given with
3345 expanded arguments. */
3346
3347 case EITEM_HASH:
3348 case EITEM_LENGTH:
3349 case EITEM_NHASH:
3350 case EITEM_SUBSTR:
3351 {
3352 int i;
3353 int len;
3354 uschar *ret;
3355 int val[2] = { 0, -1 };
3356 uschar *sub[3];
3357
3358 /* "length" takes only 2 arguments whereas the others take 2 or 3.
3359 Ensure that sub[2] is set in the ${length case. */
3360
3361 sub[2] = NULL;
3362 switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
3363 TRUE, name))
3364 {
3365 case 1: goto EXPAND_FAILED_CURLY;
3366 case 2:
3367 case 3: goto EXPAND_FAILED;
3368 }
3369
3370 /* Juggle the arguments if there are only two of them: always move the
3371 string to the last position and make ${length{n}{str}} equivalent to
3372 ${substr{0}{n}{str}}. See the defaults for val[] above. */
3373
3374 if (sub[2] == NULL)
3375 {
3376 sub[2] = sub[1];
3377 sub[1] = NULL;
3378 if (item_type == EITEM_LENGTH)
3379 {
3380 sub[1] = sub[0];
3381 sub[0] = NULL;
3382 }
3383 }
3384
3385 for (i = 0; i < 2; i++)
3386 {
3387 if (sub[i] == NULL) continue;
3388 val[i] = (int)Ustrtol(sub[i], &ret, 10);
3389 if (*ret != 0 || (i != 0 && val[i] < 0))
3390 {
3391 expand_string_message = string_sprintf("\"%s\" is not a%s number "
3392 "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
3393 goto EXPAND_FAILED;
3394 }
3395 }
3396
3397 ret =
3398 (item_type == EITEM_HASH)?
3399 compute_hash(sub[2], val[0], val[1], &len) :
3400 (item_type == EITEM_NHASH)?
3401 compute_nhash(sub[2], val[0], val[1], &len) :
3402 extract_substr(sub[2], val[0], val[1], &len);
3403
3404 if (ret == NULL) goto EXPAND_FAILED;
3405 yield = string_cat(yield, &size, &ptr, ret, len);
3406 continue;
3407 }
3408
3409 /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
3410 This code originally contributed by Steve Haslam. It currently supports
3411 the use of MD5 and SHA-1 hashes.
3412
3413 We need some workspace that is large enough to handle all the supported
3414 hash types. Use macros to set the sizes rather than be too elaborate. */
3415
3416 #define MAX_HASHLEN 20
3417 #define MAX_HASHBLOCKLEN 64
3418
3419 case EITEM_HMAC:
3420 {
3421 uschar *sub[3];
3422 md5 md5_base;
3423 sha1 sha1_base;
3424 void *use_base;
3425 int type, i;
3426 int hashlen; /* Number of octets for the hash algorithm's output */
3427 int hashblocklen; /* Number of octets the hash algorithm processes */
3428 uschar *keyptr, *p;
3429 unsigned int keylen;
3430
3431 uschar keyhash[MAX_HASHLEN];
3432 uschar innerhash[MAX_HASHLEN];
3433 uschar finalhash[MAX_HASHLEN];
3434 uschar finalhash_hex[2*MAX_HASHLEN];
3435 uschar innerkey[MAX_HASHBLOCKLEN];
3436 uschar outerkey[MAX_HASHBLOCKLEN];
3437
3438 switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
3439 {
3440 case 1: goto EXPAND_FAILED_CURLY;
3441 case 2:
3442 case 3: goto EXPAND_FAILED;
3443 }
3444
3445 if (Ustrcmp(sub[0], "md5") == 0)
3446 {
3447 type = HMAC_MD5;
3448 use_base = &md5_base;
3449 hashlen = 16;
3450 hashblocklen = 64;
3451 }
3452 else if (Ustrcmp(sub[0], "sha1") == 0)
3453 {
3454 type = HMAC_SHA1;
3455 use_base = &sha1_base;
3456 hashlen = 20;
3457 hashblocklen = 64;
3458 }
3459 else
3460 {
3461 expand_string_message =
3462 string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
3463 goto EXPAND_FAILED;
3464 }
3465
3466 keyptr = sub[1];
3467 keylen = Ustrlen(keyptr);
3468
3469 /* If the key is longer than the hash block length, then hash the key
3470 first */
3471
3472 if (keylen > hashblocklen)
3473 {
3474 chash_start(type, use_base);
3475 chash_end(type, use_base, keyptr, keylen, keyhash);
3476 keyptr = keyhash;
3477 keylen = hashlen;
3478 }
3479
3480 /* Now make the inner and outer key values */
3481
3482 memset(innerkey, 0x36, hashblocklen);
3483 memset(outerkey, 0x5c, hashblocklen);
3484
3485 for (i = 0; i < keylen; i++)
3486 {
3487 innerkey[i] ^= keyptr[i];
3488 outerkey[i] ^= keyptr[i];
3489 }
3490
3491 /* Now do the hashes */
3492
3493 chash_start(type, use_base);
3494 chash_mid(type, use_base, innerkey);
3495 chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
3496
3497 chash_start(type, use_base);
3498 chash_mid(type, use_base, outerkey);
3499 chash_end(type, use_base, innerhash, hashlen, finalhash);
3500
3501 /* Encode the final hash as a hex string */
3502
3503 p = finalhash_hex;
3504 for (i = 0; i < hashlen; i++)
3505 {
3506 *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3507 *p++ = hex_digits[finalhash[i] & 0x0f];
3508 }
3509
3510 DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
3511 (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
3512
3513 yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
3514 }
3515
3516 continue;
3517
3518 /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
3519 We have to save the numerical variables and restore them afterwards. */
3520
3521 case EITEM_SG:
3522 {
3523 const pcre *re;
3524 int moffset, moffsetextra, slen;
3525 int roffset;
3526 int emptyopt;
3527 const uschar *rerror;
3528 uschar *subject;
3529 uschar *sub[3];
3530 int save_expand_nmax =
3531 save_expand_strings(save_expand_nstring, save_expand_nlength);
3532
3533 switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
3534 {
3535 case 1: goto EXPAND_FAILED_CURLY;
3536 case 2:
3537 case 3: goto EXPAND_FAILED;
3538 }
3539
3540 /* Compile the regular expression */
3541
3542 re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
3543 NULL);
3544
3545 if (re == NULL)
3546 {
3547 expand_string_message = string_sprintf("regular expression error in "
3548 "\"%s\": %s at offset %d", sub[1], rerror, roffset);
3549 goto EXPAND_FAILED;
3550 }
3551
3552 /* Now run a loop to do the substitutions as often as necessary. It ends
3553 when there are no more matches. Take care over matches of the null string;
3554 do the same thing as Perl does. */
3555
3556 subject = sub[0];
3557 slen = Ustrlen(sub[0]);
3558 moffset = moffsetextra = 0;
3559 emptyopt = 0;
3560
3561 for (;;)
3562 {
3563 int ovector[3*(EXPAND_MAXN+1)];
3564 int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
3565 PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
3566 int nn;
3567 uschar *insert;
3568
3569 /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
3570 is not necessarily the end. We want to repeat the match from one
3571 character further along, but leaving the basic offset the same (for
3572 copying below). We can't be at the end of the string - that was checked
3573 before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
3574 finished; copy the remaining string and end the loop. */
3575
3576 if (n < 0)
3577 {
3578 if (emptyopt != 0)
3579 {
3580 moffsetextra = 1;
3581 emptyopt = 0;
3582 continue;
3583 }
3584 yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
3585 break;
3586 }
3587
3588 /* Match - set up for expanding the replacement. */
3589
3590 if (n == 0) n = EXPAND_MAXN + 1;
3591 expand_nmax = 0;
3592 for (nn = 0; nn < n*2; nn += 2)
3593 {
3594 expand_nstring[expand_nmax] = subject + ovector[nn];
3595 expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
3596 }
3597 expand_nmax--;
3598
3599 /* Copy the characters before the match, plus the expanded insertion. */
3600
3601 yield = string_cat(yield, &size, &ptr, subject + moffset,
3602 ovector[0] - moffset);
3603 insert = expand_string(sub[2]);
3604 if (insert == NULL) goto EXPAND_FAILED;
3605 yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
3606
3607 moffset = ovector[1];
3608 moffsetextra = 0;
3609 emptyopt = 0;
3610
3611 /* If we have matched an empty string, first check to see if we are at
3612 the end of the subject. If so, the loop is over. Otherwise, mimic
3613 what Perl's /g options does. This turns out to be rather cunning. First
3614 we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
3615 string at the same point. If this fails (picked up above) we advance to
3616 the next character. */
3617
3618 if (ovector[0] == ovector[1])
3619 {
3620 if (ovector[0] == slen) break;
3621 emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
3622 }
3623 }
3624
3625 /* All done - restore numerical variables. */
3626
3627 restore_expand_strings(save_expand_nmax, save_expand_nstring,
3628 save_expand_nlength);
3629 continue;
3630 }
3631
3632 /* Handle keyed and numbered substring extraction. If the first argument
3633 consists entirely of digits, then a numerical extraction is assumed. */
3634
3635 case EITEM_EXTRACT:
3636 {
3637 int i;
3638 int j = 2;
3639 int field_number = 1;
3640 BOOL field_number_set = FALSE;
3641 uschar *save_lookup_value = lookup_value;
3642 uschar *sub[3];
3643 int save_expand_nmax =
3644 save_expand_strings(save_expand_nstring, save_expand_nlength);
3645
3646 /* Read the arguments */
3647
3648 for (i = 0; i < j; i++)
3649 {
3650 while (isspace(*s)) s++;
3651 if (*s == '{')
3652 {
3653 sub[i] = expand_string_internal(s+1, TRUE, &s, skipping);
3654 if (sub[i] == NULL) goto EXPAND_FAILED;
3655 if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3656
3657 /* After removal of leading and trailing white space, the first
3658 argument must not be empty; if it consists entirely of digits
3659 (optionally preceded by a minus sign), this is a numerical
3660 extraction, and we expect 3 arguments. */
3661
3662 if (i == 0)
3663 {
3664 int len;
3665 int x = 0;
3666 uschar *p = sub[0];
3667
3668 while (isspace(*p)) p++;
3669 sub[0] = p;
3670
3671 len = Ustrlen(p);
3672 while (len > 0 && isspace(p[len-1])) len--;
3673 p[len] = 0;
3674
3675 if (*p == 0)
3676 {
3677 expand_string_message = US"first argument of \"expand\" must not "
3678 "be empty";
3679 goto EXPAND_FAILED;
3680 }
3681
3682 if (*p == '-')
3683 {
3684 field_number = -1;
3685 p++;
3686 }
3687 while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
3688 if (*p == 0)
3689 {
3690 field_number *= x;
3691 j = 3; /* Need 3 args */
3692 field_number_set = TRUE;
3693 }
3694 }
3695 }
3696 else goto EXPAND_FAILED_CURLY;
3697 }
3698
3699 /* Extract either the numbered or the keyed substring into $value. If
3700 skipping, just pretend the extraction failed. */
3701
3702 lookup_value = skipping? NULL : field_number_set?
3703 expand_gettokened(field_number, sub[1], sub[2]) :
3704 expand_getkeyed(sub[0], sub[1]);
3705
3706 /* If no string follows, $value gets substituted; otherwise there can
3707 be yes/no strings, as for lookup or if. */
3708
3709 switch(process_yesno(
3710 skipping, /* were previously skipping */
3711 lookup_value != NULL, /* success/failure indicator */
3712 save_lookup_value, /* value to reset for string2 */
3713 &s, /* input pointer */
3714 &yield, /* output pointer */
3715 &size, /* output size */
3716 &ptr, /* output current point */
3717 US"extract")) /* condition type */
3718 {
3719 case 1: goto EXPAND_FAILED; /* when all is well, the */
3720 case 2: goto EXPAND_FAILED_CURLY; /* returned value is 0 */
3721 }
3722
3723 /* All done - restore numerical variables. */
3724
3725 restore_expand_strings(save_expand_nmax, save_expand_nstring,
3726 save_expand_nlength);
3727
3728 continue;
3729 }
3730 }
3731
3732 /* Control reaches here if the name is not recognized as one of the more
3733 complicated expansion items. Check for the "operator" syntax (name terminated
3734 by a colon). Some of the operators have arguments, separated by _ from the
3735 name. */
3736
3737 if (*s == ':')
3738 {
3739 int c;
3740 uschar *arg = NULL;
3741 uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping);
3742 if (sub == NULL) goto EXPAND_FAILED;
3743 s++;
3744
3745 /* Owing to an historical mis-design, an underscore may be part of the
3746 operator name, or it may introduce arguments. We therefore first scan the
3747 table of names that contain underscores. If there is no match, we cut off
3748 the arguments and then scan the main table. */
3749
3750 c = chop_match(name, op_table_underscore,
3751 sizeof(op_table_underscore)/sizeof(uschar *));
3752
3753 if (c < 0)
3754 {
3755 arg = Ustrchr(name, '_');
3756 if (arg != NULL) *arg = 0;
3757 c = chop_match(name, op_table_main,
3758 sizeof(op_table_main)/sizeof(uschar *));
3759 if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
3760 if (arg != NULL) *arg++ = '_'; /* Put back for error messages */
3761 }
3762
3763 /* If we are skipping, we don't need to perform the operation at all.
3764 This matters for operations like "mask", because the data may not be
3765 in the correct format when skipping. For example, the expression may test
3766 for the existence of $sender_host_address before trying to mask it. For
3767 other operations, doing them may not fail, but it is a waste of time. */
3768
3769 if (skipping && c >= 0) continue;
3770
3771 /* Otherwise, switch on the operator type */
3772
3773 switch(c)
3774 {
3775 case EOP_BASE62:
3776 {
3777 uschar *t;
3778 unsigned long int n = Ustrtoul(sub, &t, 10);
3779 if (*t != 0)
3780 {
3781 expand_string_message = string_sprintf("argument for base62 "
3782 "operator is \"%s\", which is not a decimal number", sub);
3783 goto EXPAND_FAILED;
3784 }
3785 t = string_base62(n);
3786 yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
3787 continue;
3788 }
3789
3790 case EOP_BASE62D:
3791 {
3792 uschar buf[16];
3793 uschar *tt = sub;
3794 unsigned long int n = 0;
3795 while (*tt != 0)
3796 {
3797 uschar *t = Ustrchr(base62_chars, *tt++);
3798 if (t == NULL)
3799 {
3800 expand_string_message = string_sprintf("argument for base62d "
3801 "operator is \"%s\", which is not a base 62 number", sub);
3802 goto EXPAND_FAILED;
3803 }
3804 n = n * 62 + (t - base62_chars);
3805 }
3806 (void)sprintf(CS buf, "%ld", n);
3807 yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
3808 continue;
3809 }
3810
3811 case EOP_EXPAND:
3812 {
3813 uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping);
3814 if (expanded == NULL)
3815 {
3816 expand_string_message =
3817 string_sprintf("internal expansion of \"%s\" failed: %s", sub,
3818 expand_string_message);
3819 goto EXPAND_FAILED;
3820 }
3821 yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
3822 continue;
3823 }
3824
3825 case EOP_LC:
3826 {
3827 int count = 0;
3828 uschar *t = sub - 1;
3829 while (*(++t) != 0) { *t = tolower(*t); count++; }
3830 yield = string_cat(yield, &size, &ptr, sub, count);
3831 continue;
3832 }
3833
3834 case EOP_UC:
3835 {
3836 int count = 0;
3837 uschar *t = sub - 1;
3838 while (*(++t) != 0) { *t = toupper(*t); count++; }
3839 yield = string_cat(yield, &size, &ptr, sub, count);
3840 continue;
3841 }
3842
3843 case EOP_MD5:
3844 {
3845 md5 base;
3846 uschar digest[16];
3847 int j;
3848 char st[33];
3849 md5_start(&base);
3850 md5_end(&base, sub, Ustrlen(sub), digest);
3851 for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
3852 yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
3853 continue;
3854 }
3855
3856 case EOP_SHA1:
3857 {
3858 sha1 base;
3859 uschar digest[20];
3860 int j;
3861 char st[41];
3862 sha1_start(&base);
3863 sha1_end(&base, sub, Ustrlen(sub), digest);
3864 for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
3865 yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
3866 continue;
3867 }
3868
3869 /* Convert hex encoding to base64 encoding */
3870
3871 case EOP_HEX2B64:
3872 {
3873 int c = 0;
3874 int b = -1;
3875 uschar *in = sub;
3876 uschar *out = sub;
3877 uschar *enc;
3878
3879 for (enc = sub; *enc != 0; enc++)
3880 {
3881 if (!isxdigit(*enc))
3882 {
3883 expand_string_message = string_sprintf("\"%s\" is not a hex "
3884 "string", sub);
3885 goto EXPAND_FAILED;
3886 }
3887 c++;
3888 }
3889
3890 if ((c & 1) != 0)
3891 {
3892 expand_string_message = string_sprintf("\"%s\" contains an odd "
3893 "number of characters", sub);
3894 goto EXPAND_FAILED;
3895 }
3896
3897 while ((c = *in++) != 0)
3898 {
3899 if (isdigit(c)) c -= '0';
3900 else c = toupper(c) - 'A' + 10;
3901 if (b == -1)
3902 {
3903 b = c << 4;
3904 }
3905 else
3906 {
3907 *out++ = b | c;
3908 b = -1;
3909 }
3910 }
3911
3912 enc = auth_b64encode(sub, out - sub);
3913 yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
3914 continue;
3915 }
3916
3917 /* mask applies a mask to an IP address; for example the result of
3918 ${mask:131.111.10.206/28} is 131.111.10.192/28. */
3919
3920 case EOP_MASK:
3921 {
3922 int count;
3923 uschar *endptr;
3924 int binary[4];
3925 int mask, maskoffset;
3926 int type = string_is_ip_address(sub, &maskoffset);
3927 uschar buffer[64];
3928
3929 if (type == 0)
3930 {
3931 expand_string_message = string_sprintf("\"%s\" is not an IP address",
3932 sub);
3933 goto EXPAND_FAILED;
3934 }
3935
3936 if (maskoffset == 0)
3937 {
3938 expand_string_message = string_sprintf("missing mask value in \"%s\"",
3939 sub);
3940 goto EXPAND_FAILED;
3941 }
3942
3943 mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
3944
3945 if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
3946 {
3947 expand_string_message = string_sprintf("mask value too big in \"%s\"",
3948 sub);
3949 goto EXPAND_FAILED;
3950 }
3951