ratelimit fix: omit the limit parameter from the database lookup
[exim.git] / src / src / acl.c
1 /* $Cambridge: exim/src/src/acl.c,v 1.37 2005/05/31 17:07:39 fanf2 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2005 */
8 /* See the file NOTICE for conditions of use and distribution. */
9
10 /* Code for handling Access Control Lists (ACLs) */
11
12 #include "exim.h"
13
14
15 /* Default callout timeout */
16
17 #define CALLOUT_TIMEOUT_DEFAULT 30
18
19 /* ACL verb codes - keep in step with the table of verbs that follows */
20
21 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
22 ACL_WARN };
23
24 /* ACL verbs */
25
26 static uschar *verbs[] =
27 { US"accept", US"defer", US"deny", US"discard", US"drop", US"require",
28 US"warn" };
29
30 /* For each verb, the condition for which "message" is used */
31
32 static int msgcond[] = { FAIL, OK, OK, FAIL, OK, FAIL, OK };
33
34 /* ACL condition and modifier codes - keep in step with the table that
35 follows. */
36
37 enum { ACLC_ACL, ACLC_AUTHENTICATED,
38 #ifdef EXPERIMENTAL_BRIGHTMAIL
39 ACLC_BMI_OPTIN,
40 #endif
41 ACLC_CONDITION, ACLC_CONTROL,
42 #ifdef WITH_CONTENT_SCAN
43 ACLC_DECODE,
44 #endif
45 ACLC_DELAY,
46 #ifdef WITH_OLD_DEMIME
47 ACLC_DEMIME,
48 #endif
49 #ifdef EXPERIMENTAL_DOMAINKEYS
50 ACLC_DK_DOMAIN_SOURCE,
51 ACLC_DK_POLICY,
52 ACLC_DK_SENDER_DOMAINS,
53 ACLC_DK_SENDER_LOCAL_PARTS,
54 ACLC_DK_SENDERS,
55 ACLC_DK_STATUS,
56 #endif
57 ACLC_DNSLISTS, ACLC_DOMAINS, ACLC_ENCRYPTED, ACLC_ENDPASS,
58 ACLC_HOSTS, ACLC_LOCAL_PARTS, ACLC_LOG_MESSAGE, ACLC_LOGWRITE,
59 #ifdef WITH_CONTENT_SCAN
60 ACLC_MALWARE,
61 #endif
62 ACLC_MESSAGE,
63 #ifdef WITH_CONTENT_SCAN
64 ACLC_MIME_REGEX,
65 #endif
66 ACLC_RATELIMIT,
67 ACLC_RECIPIENTS,
68 #ifdef WITH_CONTENT_SCAN
69 ACLC_REGEX,
70 #endif
71 ACLC_SENDER_DOMAINS, ACLC_SENDERS, ACLC_SET,
72 #ifdef WITH_CONTENT_SCAN
73 ACLC_SPAM,
74 #endif
75 #ifdef EXPERIMENTAL_SPF
76 ACLC_SPF,
77 #endif
78 ACLC_VERIFY };
79
80 /* ACL conditions/modifiers: "delay", "control", "endpass", "message",
81 "log_message", "logwrite", and "set" are modifiers that look like conditions
82 but always return TRUE. They are used for their side effects. */
83
84 static uschar *conditions[] = { US"acl", US"authenticated",
85 #ifdef EXPERIMENTAL_BRIGHTMAIL
86 US"bmi_optin",
87 #endif
88 US"condition",
89 US"control",
90 #ifdef WITH_CONTENT_SCAN
91 US"decode",
92 #endif
93 US"delay",
94 #ifdef WITH_OLD_DEMIME
95 US"demime",
96 #endif
97 #ifdef EXPERIMENTAL_DOMAINKEYS
98 US"dk_domain_source",
99 US"dk_policy",
100 US"dk_sender_domains",
101 US"dk_sender_local_parts",
102 US"dk_senders",
103 US"dk_status",
104 #endif
105 US"dnslists", US"domains", US"encrypted",
106 US"endpass", US"hosts", US"local_parts", US"log_message", US"logwrite",
107 #ifdef WITH_CONTENT_SCAN
108 US"malware",
109 #endif
110 US"message",
111 #ifdef WITH_CONTENT_SCAN
112 US"mime_regex",
113 #endif
114 US"ratelimit",
115 US"recipients",
116 #ifdef WITH_CONTENT_SCAN
117 US"regex",
118 #endif
119 US"sender_domains", US"senders", US"set",
120 #ifdef WITH_CONTENT_SCAN
121 US"spam",
122 #endif
123 #ifdef EXPERIMENTAL_SPF
124 US"spf",
125 #endif
126 US"verify" };
127
128 /* ACL control names */
129
130 static uschar *controls[] = { US"error", US"caseful_local_part",
131 US"caselower_local_part", US"enforce_sync", US"no_enforce_sync", US"freeze",
132 US"queue_only", US"submission", US"no_multiline"};
133
134 /* Flags to indicate for which conditions /modifiers a string expansion is done
135 at the outer level. In the other cases, expansion already occurs in the
136 checking functions. */
137
138 static uschar cond_expand_at_top[] = {
139 TRUE, /* acl */
140 FALSE, /* authenticated */
141 #ifdef EXPERIMENTAL_BRIGHTMAIL
142 TRUE, /* bmi_optin */
143 #endif
144 TRUE, /* condition */
145 TRUE, /* control */
146 #ifdef WITH_CONTENT_SCAN
147 TRUE, /* decode */
148 #endif
149 TRUE, /* delay */
150 #ifdef WITH_OLD_DEMIME
151 TRUE, /* demime */
152 #endif
153 #ifdef EXPERIMENTAL_DOMAINKEYS
154 TRUE, /* dk_domain_source */
155 TRUE, /* dk_policy */
156 TRUE, /* dk_sender_domains */
157 TRUE, /* dk_sender_local_parts */
158 TRUE, /* dk_senders */
159 TRUE, /* dk_status */
160 #endif
161 TRUE, /* dnslists */
162 FALSE, /* domains */
163 FALSE, /* encrypted */
164 TRUE, /* endpass */
165 FALSE, /* hosts */
166 FALSE, /* local_parts */
167 TRUE, /* log_message */
168 TRUE, /* logwrite */
169 #ifdef WITH_CONTENT_SCAN
170 TRUE, /* malware */
171 #endif
172 TRUE, /* message */
173 #ifdef WITH_CONTENT_SCAN
174 TRUE, /* mime_regex */
175 #endif
176 TRUE, /* ratelimit */
177 FALSE, /* recipients */
178 #ifdef WITH_CONTENT_SCAN
179 TRUE, /* regex */
180 #endif
181 FALSE, /* sender_domains */
182 FALSE, /* senders */
183 TRUE, /* set */
184 #ifdef WITH_CONTENT_SCAN
185 TRUE, /* spam */
186 #endif
187 #ifdef EXPERIMENTAL_SPF
188 TRUE, /* spf */
189 #endif
190 TRUE /* verify */
191 };
192
193 /* Flags to identify the modifiers */
194
195 static uschar cond_modifiers[] = {
196 FALSE, /* acl */
197 FALSE, /* authenticated */
198 #ifdef EXPERIMENTAL_BRIGHTMAIL
199 TRUE, /* bmi_optin */
200 #endif
201 FALSE, /* condition */
202 TRUE, /* control */
203 #ifdef WITH_CONTENT_SCAN
204 FALSE, /* decode */
205 #endif
206 TRUE, /* delay */
207 #ifdef WITH_OLD_DEMIME
208 FALSE, /* demime */
209 #endif
210 #ifdef EXPERIMENTAL_DOMAINKEYS
211 FALSE, /* dk_domain_source */
212 FALSE, /* dk_policy */
213 FALSE, /* dk_sender_domains */
214 FALSE, /* dk_sender_local_parts */
215 FALSE, /* dk_senders */
216 FALSE, /* dk_status */
217 #endif
218 FALSE, /* dnslists */
219 FALSE, /* domains */
220 FALSE, /* encrypted */
221 TRUE, /* endpass */
222 FALSE, /* hosts */
223 FALSE, /* local_parts */
224 TRUE, /* log_message */
225 TRUE, /* logwrite */
226 #ifdef WITH_CONTENT_SCAN
227 FALSE, /* malware */
228 #endif
229 TRUE, /* message */
230 #ifdef WITH_CONTENT_SCAN
231 FALSE, /* mime_regex */
232 #endif
233 FALSE, /* ratelimit */
234 FALSE, /* recipients */
235 #ifdef WITH_CONTENT_SCAN
236 FALSE, /* regex */
237 #endif
238 FALSE, /* sender_domains */
239 FALSE, /* senders */
240 TRUE, /* set */
241 #ifdef WITH_CONTENT_SCAN
242 FALSE, /* spam */
243 #endif
244 #ifdef EXPERIMENTAL_SPF
245 FALSE, /* spf */
246 #endif
247 FALSE /* verify */
248 };
249
250 /* Bit map vector of which conditions are not allowed at certain times. For
251 each condition, there's a bitmap of dis-allowed times. For some, it is easier
252 to specify the negation of a small number of allowed times. */
253
254 static unsigned int cond_forbids[] = {
255 0, /* acl */
256
257 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_CONNECT)| /* authenticated */
258 (1<<ACL_WHERE_HELO),
259
260 #ifdef EXPERIMENTAL_BRIGHTMAIL
261 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
262 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
263 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
264 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
265 (1<<ACL_WHERE_MAILAUTH)|
266 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
267 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA),
268 #endif
269
270 0, /* condition */
271
272 /* Certain types of control are always allowed, so we let it through
273 always and check in the control processing itself. */
274
275 0, /* control */
276
277 #ifdef WITH_CONTENT_SCAN
278 (unsigned int)
279 ~(1<<ACL_WHERE_MIME), /* decode */
280 #endif
281
282 0, /* delay */
283
284 #ifdef WITH_OLD_DEMIME
285 (unsigned int)
286 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
287 #endif
288
289 #ifdef EXPERIMENTAL_DOMAINKEYS
290 (1<<ACL_WHERE_AUTH)| /* dk_domain_source */
291 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
292 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
293 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
294 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
295 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
296 (1<<ACL_WHERE_VRFY),
297
298 (1<<ACL_WHERE_AUTH)| /* dk_policy */
299 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
300 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
301 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
302 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
303 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
304 (1<<ACL_WHERE_VRFY),
305
306 (1<<ACL_WHERE_AUTH)| /* dk_sender_domains */
307 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
308 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
309 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
310 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
311 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
312 (1<<ACL_WHERE_VRFY),
313
314 (1<<ACL_WHERE_AUTH)| /* dk_sender_local_parts */
315 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
316 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
317 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
318 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
319 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
320 (1<<ACL_WHERE_VRFY),
321
322 (1<<ACL_WHERE_AUTH)| /* dk_senders */
323 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
324 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
325 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
326 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
327 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
328 (1<<ACL_WHERE_VRFY),
329
330 (1<<ACL_WHERE_AUTH)| /* dk_status */
331 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
332 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
333 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
334 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
335 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
336 (1<<ACL_WHERE_VRFY),
337 #endif
338
339 (1<<ACL_WHERE_NOTSMTP), /* dnslists */
340
341 (unsigned int)
342 ~(1<<ACL_WHERE_RCPT), /* domains */
343
344 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_CONNECT)| /* encrypted */
345 (1<<ACL_WHERE_HELO),
346
347 0, /* endpass */
348
349 (1<<ACL_WHERE_NOTSMTP), /* hosts */
350
351 (unsigned int)
352 ~(1<<ACL_WHERE_RCPT), /* local_parts */
353
354 0, /* log_message */
355
356 0, /* logwrite */
357
358 #ifdef WITH_CONTENT_SCAN
359 (unsigned int)
360 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
361 #endif
362
363 0, /* message */
364
365 #ifdef WITH_CONTENT_SCAN
366 (unsigned int)
367 ~(1<<ACL_WHERE_MIME), /* mime_regex */
368 #endif
369
370 0, /* ratelimit */
371
372 (unsigned int)
373 ~(1<<ACL_WHERE_RCPT), /* recipients */
374
375 #ifdef WITH_CONTENT_SCAN
376 (unsigned int)
377 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
378 (1<<ACL_WHERE_MIME)),
379 #endif
380
381 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
382 (1<<ACL_WHERE_HELO)|
383 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
384 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
385 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
386
387 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
388 (1<<ACL_WHERE_HELO)|
389 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
390 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
391 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
392
393 0, /* set */
394
395 #ifdef WITH_CONTENT_SCAN
396 (unsigned int)
397 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
398 #endif
399
400 #ifdef EXPERIMENTAL_SPF
401 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
402 (1<<ACL_WHERE_HELO)|
403 (1<<ACL_WHERE_MAILAUTH)|
404 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
405 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
406 #endif
407
408 /* Certain types of verify are always allowed, so we let it through
409 always and check in the verify function itself */
410
411 0 /* verify */
412 };
413
414
415 /* Return values from decode_control() */
416
417 enum {
418 #ifdef EXPERIMENTAL_BRIGHTMAIL
419 CONTROL_BMI_RUN,
420 #endif
421 #ifdef EXPERIMENTAL_DOMAINKEYS
422 CONTROL_DK_VERIFY,
423 #endif
424 CONTROL_ERROR, CONTROL_CASEFUL_LOCAL_PART, CONTROL_CASELOWER_LOCAL_PART,
425 CONTROL_ENFORCE_SYNC, CONTROL_NO_ENFORCE_SYNC, CONTROL_FREEZE,
426 CONTROL_QUEUE_ONLY, CONTROL_SUBMISSION,
427 #ifdef WITH_CONTENT_SCAN
428 CONTROL_NO_MBOX_UNSPOOL,
429 #endif
430 CONTROL_FAKEDEFER, CONTROL_FAKEREJECT, CONTROL_NO_MULTILINE };
431
432 /* Bit map vector of which controls are not allowed at certain times. For
433 each control, there's a bitmap of dis-allowed times. For some, it is easier to
434 specify the negation of a small number of allowed times. */
435
436 static unsigned int control_forbids[] = {
437 #ifdef EXPERIMENTAL_BRIGHTMAIL
438 0, /* bmi_run */
439 #endif
440 #ifdef EXPERIMENTAL_DOMAINKEYS
441 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), /* dk_verify */
442 #endif
443
444 0, /* error */
445
446 (unsigned int)
447 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
448
449 (unsigned int)
450 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
451
452 (1<<ACL_WHERE_NOTSMTP), /* enforce_sync */
453
454 (1<<ACL_WHERE_NOTSMTP), /* no_enforce_sync */
455
456 (unsigned int)
457 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
458 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
459 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
460
461 (unsigned int)
462 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
463 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
464 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
465
466 (unsigned int)
467 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
468 (1<<ACL_WHERE_PREDATA)),
469
470 #ifdef WITH_CONTENT_SCAN
471 (unsigned int)
472 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
473 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
474 (1<<ACL_WHERE_MIME)),
475 #endif
476
477 (unsigned int)
478 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
479 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
480 (1<<ACL_WHERE_MIME)),
481
482 (unsigned int)
483 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
484 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
485 (1<<ACL_WHERE_MIME)),
486
487 (1<<ACL_WHERE_NOTSMTP) /* no_multiline */
488 };
489
490 /* Structure listing various control arguments, with their characteristics. */
491
492 typedef struct control_def {
493 uschar *name;
494 int value; /* CONTROL_xxx value */
495 BOOL has_option; /* Has /option(s) following */
496 } control_def;
497
498 static control_def controls_list[] = {
499 #ifdef EXPERIMENTAL_BRIGHTMAIL
500 { US"bmi_run", CONTROL_BMI_RUN, FALSE},
501 #endif
502 #ifdef EXPERIMENTAL_DOMAINKEYS
503 { US"dk_verify", CONTROL_DK_VERIFY, FALSE},
504 #endif
505 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE},
506 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE},
507 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE},
508 { US"freeze", CONTROL_FREEZE, FALSE},
509 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE},
510 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE},
511 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE},
512 #ifdef WITH_CONTENT_SCAN
513 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE},
514 #endif
515 { US"fakedefer", CONTROL_FAKEDEFER, TRUE},
516 { US"fakereject", CONTROL_FAKEREJECT, TRUE},
517 { US"submission", CONTROL_SUBMISSION, TRUE}
518 };
519
520 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
521 caches its result in a tree to avoid repeated DNS queries. The result is an
522 integer code which is used as an index into the following tables of
523 explanatory strings and verification return codes. */
524
525 static tree_node *csa_cache = NULL;
526
527 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
528 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
529
530 /* The acl_verify_csa() return code is translated into an acl_verify() return
531 code using the following table. It is OK unless the client is definitely not
532 authorized. This is because CSA is supposed to be optional for sending sites,
533 so recipients should not be too strict about checking it - especially because
534 DNS problems are quite likely to occur. It's possible to use $csa_status in
535 further ACL conditions to distinguish ok, unknown, and defer if required, but
536 the aim is to make the usual configuration simple. */
537
538 static int csa_return_code[] = {
539 OK, OK, OK, OK,
540 FAIL, FAIL, FAIL, FAIL
541 };
542
543 static uschar *csa_status_string[] = {
544 US"unknown", US"ok", US"defer", US"defer",
545 US"fail", US"fail", US"fail", US"fail"
546 };
547
548 static uschar *csa_reason_string[] = {
549 US"unknown",
550 US"ok",
551 US"deferred (SRV lookup failed)",
552 US"deferred (target address lookup failed)",
553 US"failed (explicit authorization required)",
554 US"failed (host name not authorized)",
555 US"failed (no authorized addresses)",
556 US"failed (client address mismatch)"
557 };
558
559 /* Enable recursion between acl_check_internal() and acl_check_condition() */
560
561 static int acl_check_internal(int, address_item *, uschar *, int, uschar **,
562 uschar **);
563
564
565 /*************************************************
566 * Pick out name from list *
567 *************************************************/
568
569 /* Use a binary chop method
570
571 Arguments:
572 name name to find
573 list list of names
574 end size of list
575
576 Returns: offset in list, or -1 if not found
577 */
578
579 static int
580 acl_checkname(uschar *name, uschar **list, int end)
581 {
582 int start = 0;
583
584 while (start < end)
585 {
586 int mid = (start + end)/2;
587 int c = Ustrcmp(name, list[mid]);
588 if (c == 0) return mid;
589 if (c < 0) end = mid; else start = mid + 1;
590 }
591
592 return -1;
593 }
594
595
596 /*************************************************
597 * Read and parse one ACL *
598 *************************************************/
599
600 /* This function is called both from readconf in order to parse the ACLs in the
601 configuration file, and also when an ACL is encountered dynamically (e.g. as
602 the result of an expansion). It is given a function to call in order to
603 retrieve the lines of the ACL. This function handles skipping comments and
604 blank lines (where relevant).
605
606 Arguments:
607 func function to get next line of ACL
608 error where to put an error message
609
610 Returns: pointer to ACL, or NULL
611 NULL can be legal (empty ACL); in this case error will be NULL
612 */
613
614 acl_block *
615 acl_read(uschar *(*func)(void), uschar **error)
616 {
617 acl_block *yield = NULL;
618 acl_block **lastp = &yield;
619 acl_block *this = NULL;
620 acl_condition_block *cond;
621 acl_condition_block **condp = NULL;
622 uschar *s;
623
624 *error = NULL;
625
626 while ((s = (*func)()) != NULL)
627 {
628 int v, c;
629 BOOL negated = FALSE;
630 uschar *saveline = s;
631 uschar name[64];
632
633 /* Conditions (but not verbs) are allowed to be negated by an initial
634 exclamation mark. */
635
636 while (isspace(*s)) s++;
637 if (*s == '!')
638 {
639 negated = TRUE;
640 s++;
641 }
642
643 /* Read the name of a verb or a condition, or the start of a new ACL, which
644 can be started by a name, or by a macro definition. */
645
646 s = readconf_readname(name, sizeof(name), s);
647 if (*s == ':' || isupper(name[0] && *s == '=')) return yield;
648
649 /* If a verb is unrecognized, it may be another condition or modifier that
650 continues the previous verb. */
651
652 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
653 if (v < 0)
654 {
655 if (this == NULL)
656 {
657 *error = string_sprintf("unknown ACL verb in \"%s\"", saveline);
658 return NULL;
659 }
660 }
661
662 /* New verb */
663
664 else
665 {
666 if (negated)
667 {
668 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
669 return NULL;
670 }
671 this = store_get(sizeof(acl_block));
672 *lastp = this;
673 lastp = &(this->next);
674 this->next = NULL;
675 this->verb = v;
676 this->condition = NULL;
677 condp = &(this->condition);
678 if (*s == 0) continue; /* No condition on this line */
679 if (*s == '!')
680 {
681 negated = TRUE;
682 s++;
683 }
684 s = readconf_readname(name, sizeof(name), s); /* Condition name */
685 }
686
687 /* Handle a condition or modifier. */
688
689 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
690 if (c < 0)
691 {
692 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
693 saveline);
694 return NULL;
695 }
696
697 /* The modifiers may not be negated */
698
699 if (negated && cond_modifiers[c])
700 {
701 *error = string_sprintf("ACL error: negation is not allowed with "
702 "\"%s\"", conditions[c]);
703 return NULL;
704 }
705
706 /* ENDPASS may occur only with ACCEPT or DISCARD. */
707
708 if (c == ACLC_ENDPASS &&
709 this->verb != ACL_ACCEPT &&
710 this->verb != ACL_DISCARD)
711 {
712 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
713 conditions[c], verbs[this->verb]);
714 return NULL;
715 }
716
717 cond = store_get(sizeof(acl_condition_block));
718 cond->next = NULL;
719 cond->type = c;
720 cond->u.negated = negated;
721
722 *condp = cond;
723 condp = &(cond->next);
724
725 /* The "set" modifier is different in that its argument is "name=value"
726 rather than just a value, and we can check the validity of the name, which
727 gives us a variable number to insert into the data block. */
728
729 if (c == ACLC_SET)
730 {
731 if (Ustrncmp(s, "acl_", 4) != 0 || (s[4] != 'c' && s[4] != 'm') ||
732 !isdigit(s[5]) || (!isspace(s[6]) && s[6] != '='))
733 {
734 *error = string_sprintf("unrecognized name after \"set\" in ACL "
735 "modifier \"set %s\"", s);
736 return NULL;
737 }
738
739 cond->u.varnumber = s[5] - '0';
740 if (s[4] == 'm') cond->u.varnumber += ACL_C_MAX;
741 s += 6;
742 while (isspace(*s)) s++;
743 }
744
745 /* For "set", we are now positioned for the data. For the others, only
746 "endpass" has no data */
747
748 if (c != ACLC_ENDPASS)
749 {
750 if (*s++ != '=')
751 {
752 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
753 cond_modifiers[c]? US"modifier" : US"condition");
754 return NULL;
755 }
756 while (isspace(*s)) s++;
757 cond->arg = string_copy(s);
758 }
759 }
760
761 return yield;
762 }
763
764
765
766 /*************************************************
767 * Handle warnings *
768 *************************************************/
769
770 /* This function is called when a WARN verb's conditions are true. It adds to
771 the message's headers, and/or writes information to the log. In each case, this
772 only happens once (per message for headers, per connection for log).
773
774 Arguments:
775 where ACL_WHERE_xxxx indicating which ACL this is
776 user_message message for adding to headers
777 log_message message for logging, if different
778
779 Returns: nothing
780 */
781
782 static void
783 acl_warn(int where, uschar *user_message, uschar *log_message)
784 {
785 int hlen;
786
787 if (log_message != NULL && log_message != user_message)
788 {
789 uschar *text;
790 string_item *logged;
791
792 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
793 string_printing(log_message));
794
795 /* If a sender verification has failed, and the log message is "sender verify
796 failed", add the failure message. */
797
798 if (sender_verified_failed != NULL &&
799 sender_verified_failed->message != NULL &&
800 strcmpic(log_message, US"sender verify failed") == 0)
801 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
802
803 /* Search previously logged warnings. They are kept in malloc
804 store so they can be freed at the start of a new message. */
805
806 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
807 if (Ustrcmp(logged->text, text) == 0) break;
808
809 if (logged == NULL)
810 {
811 int length = Ustrlen(text) + 1;
812 log_write(0, LOG_MAIN, "%s", text);
813 logged = store_malloc(sizeof(string_item) + length);
814 logged->text = (uschar *)logged + sizeof(string_item);
815 memcpy(logged->text, text, length);
816 logged->next = acl_warn_logged;
817 acl_warn_logged = logged;
818 }
819 }
820
821 /* If there's no user message, we are done. */
822
823 if (user_message == NULL) return;
824
825 /* If this isn't a message ACL, we can't do anything with a user message.
826 Log an error. */
827
828 if (where > ACL_WHERE_NOTSMTP)
829 {
830 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
831 "found in a non-message (%s) ACL: cannot specify header lines here: "
832 "message ignored", acl_wherenames[where]);
833 return;
834 }
835
836 /* Treat the user message as a sequence of one or more header lines. */
837
838 hlen = Ustrlen(user_message);
839 if (hlen > 0)
840 {
841 uschar *text, *p, *q;
842
843 /* Add a final newline if not present */
844
845 text = ((user_message)[hlen-1] == '\n')? user_message :
846 string_sprintf("%s\n", user_message);
847
848 /* Loop for multiple header lines, taking care about continuations */
849
850 for (p = q = text; *p != 0; )
851 {
852 uschar *s;
853 int newtype = htype_add_bot;
854 header_line **hptr = &acl_warn_headers;
855
856 /* Find next header line within the string */
857
858 for (;;)
859 {
860 q = Ustrchr(q, '\n');
861 if (*(++q) != ' ' && *q != '\t') break;
862 }
863
864 /* If the line starts with a colon, interpret the instruction for where to
865 add it. This temporarily sets up a new type. */
866
867 if (*p == ':')
868 {
869 if (strncmpic(p, US":after_received:", 16) == 0)
870 {
871 newtype = htype_add_rec;
872 p += 16;
873 }
874 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
875 {
876 newtype = htype_add_rfc;
877 p += 14;
878 }
879 else if (strncmpic(p, US":at_start:", 10) == 0)
880 {
881 newtype = htype_add_top;
882 p += 10;
883 }
884 else if (strncmpic(p, US":at_end:", 8) == 0)
885 {
886 newtype = htype_add_bot;
887 p += 8;
888 }
889 while (*p == ' ' || *p == '\t') p++;
890 }
891
892 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
893 to the front of it. */
894
895 for (s = p; s < q - 1; s++)
896 {
897 if (*s == ':' || !isgraph(*s)) break;
898 }
899
900 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p);
901 hlen = Ustrlen(s);
902
903 /* See if this line has already been added */
904
905 while (*hptr != NULL)
906 {
907 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
908 hptr = &((*hptr)->next);
909 }
910
911 /* Add if not previously present */
912
913 if (*hptr == NULL)
914 {
915 header_line *h = store_get(sizeof(header_line));
916 h->text = s;
917 h->next = NULL;
918 h->type = newtype;
919 h->slen = hlen;
920 *hptr = h;
921 hptr = &(h->next);
922 }
923
924 /* Advance for next header line within the string */
925
926 p = q;
927 }
928 }
929 }
930
931
932
933 /*************************************************
934 * Verify and check reverse DNS *
935 *************************************************/
936
937 /* Called from acl_verify() below. We look up the host name(s) of the client IP
938 address if this has not yet been done. The host_name_lookup() function checks
939 that one of these names resolves to an address list that contains the client IP
940 address, so we don't actually have to do the check here.
941
942 Arguments:
943 user_msgptr pointer for user message
944 log_msgptr pointer for log message
945
946 Returns: OK verification condition succeeded
947 FAIL verification failed
948 DEFER there was a problem verifying
949 */
950
951 static int
952 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
953 {
954 int rc;
955
956 user_msgptr = user_msgptr; /* stop compiler warning */
957
958 /* Previous success */
959
960 if (sender_host_name != NULL) return OK;
961
962 /* Previous failure */
963
964 if (host_lookup_failed)
965 {
966 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
967 return FAIL;
968 }
969
970 /* Need to do a lookup */
971
972 HDEBUG(D_acl)
973 debug_printf("looking up host name to force name/address consistency check\n");
974
975 if ((rc = host_name_lookup()) != OK)
976 {
977 *log_msgptr = (rc == DEFER)?
978 US"host lookup deferred for reverse lookup check"
979 :
980 string_sprintf("host lookup failed for reverse lookup check%s",
981 host_lookup_msg);
982 return rc; /* DEFER or FAIL */
983 }
984
985 host_build_sender_fullhost();
986 return OK;
987 }
988
989
990
991 /*************************************************
992 * Check client IP address matches CSA target *
993 *************************************************/
994
995 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
996 response for address records belonging to the CSA target hostname. The section
997 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
998 If one of the addresses matches the client's IP address, then the client is
999 authorized by CSA. If there are target IP addresses but none of them match
1000 then the client is using an unauthorized IP address. If there are no target IP
1001 addresses then the client cannot be using an authorized IP address. (This is
1002 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1003
1004 Arguments:
1005 dnsa the DNS answer block
1006 dnss a DNS scan block for us to use
1007 reset option specifing what portion to scan, as described above
1008 target the target hostname to use for matching RR names
1009
1010 Returns: CSA_OK successfully authorized
1011 CSA_FAIL_MISMATCH addresses found but none matched
1012 CSA_FAIL_NOADDR no target addresses found
1013 */
1014
1015 static int
1016 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1017 uschar *target)
1018 {
1019 dns_record *rr;
1020 dns_address *da;
1021
1022 BOOL target_found = FALSE;
1023
1024 for (rr = dns_next_rr(dnsa, dnss, reset);
1025 rr != NULL;
1026 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1027 {
1028 /* Check this is an address RR for the target hostname. */
1029
1030 if (rr->type != T_A
1031 #if HAVE_IPV6
1032 && rr->type != T_AAAA
1033 #ifdef SUPPORT_A6
1034 && rr->type != T_A6
1035 #endif
1036 #endif
1037 ) continue;
1038
1039 if (strcmpic(target, rr->name) != 0) continue;
1040
1041 target_found = TRUE;
1042
1043 /* Turn the target address RR into a list of textual IP addresses and scan
1044 the list. There may be more than one if it is an A6 RR. */
1045
1046 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1047 {
1048 /* If the client IP address matches the target IP address, it's good! */
1049
1050 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1051
1052 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1053 }
1054 }
1055
1056 /* If we found some target addresses but none of them matched, the client is
1057 using an unauthorized IP address, otherwise the target has no authorized IP
1058 addresses. */
1059
1060 if (target_found) return CSA_FAIL_MISMATCH;
1061 else return CSA_FAIL_NOADDR;
1062 }
1063
1064
1065
1066 /*************************************************
1067 * Verify Client SMTP Authorization *
1068 *************************************************/
1069
1070 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1071 to find the CSA SRV record corresponding to the domain argument, or
1072 $sender_helo_name if no argument is provided. It then checks that the
1073 client is authorized, and that its IP address corresponds to the SRV
1074 target's address by calling acl_verify_csa_address() above. The address
1075 should have been returned in the DNS response's ADDITIONAL section, but if
1076 not we perform another DNS lookup to get it.
1077
1078 Arguments:
1079 domain pointer to optional parameter following verify = csa
1080
1081 Returns: CSA_UNKNOWN no valid CSA record found
1082 CSA_OK successfully authorized
1083 CSA_FAIL_* client is definitely not authorized
1084 CSA_DEFER_* there was a DNS problem
1085 */
1086
1087 static int
1088 acl_verify_csa(uschar *domain)
1089 {
1090 tree_node *t;
1091 uschar *found, *p;
1092 int priority, weight, port;
1093 dns_answer dnsa;
1094 dns_scan dnss;
1095 dns_record *rr;
1096 int rc, type;
1097 uschar target[256];
1098
1099 /* Work out the domain we are using for the CSA lookup. The default is the
1100 client's HELO domain. If the client has not said HELO, use its IP address
1101 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1102
1103 while (isspace(*domain) && *domain != '\0') ++domain;
1104 if (*domain == '\0') domain = sender_helo_name;
1105 if (domain == NULL) domain = sender_host_address;
1106 if (sender_host_address == NULL) return CSA_UNKNOWN;
1107
1108 /* If we have an address literal, strip off the framing ready for turning it
1109 into a domain. The framing consists of matched square brackets possibly
1110 containing a keyword and a colon before the actual IP address. */
1111
1112 if (domain[0] == '[')
1113 {
1114 uschar *start = Ustrchr(domain, ':');
1115 if (start == NULL) start = domain;
1116 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1117 }
1118
1119 /* Turn domains that look like bare IP addresses into domains in the reverse
1120 DNS. This code also deals with address literals and $sender_host_address. It's
1121 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1122 address literals, but it's probably the most friendly thing to do. This is an
1123 extension to CSA, so we allow it to be turned off for proper conformance. */
1124
1125 if (string_is_ip_address(domain, NULL))
1126 {
1127 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1128 dns_build_reverse(domain, target);
1129 domain = target;
1130 }
1131
1132 /* Find out if we've already done the CSA check for this domain. If we have,
1133 return the same result again. Otherwise build a new cached result structure
1134 for this domain. The name is filled in now, and the value is filled in when
1135 we return from this function. */
1136
1137 t = tree_search(csa_cache, domain);
1138 if (t != NULL) return t->data.val;
1139
1140 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1141 Ustrcpy(t->name, domain);
1142 (void)tree_insertnode(&csa_cache, t);
1143
1144 /* Now we are ready to do the actual DNS lookup(s). */
1145
1146 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1147 {
1148 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1149
1150 default:
1151 return t->data.val = CSA_DEFER_SRV;
1152
1153 /* If we found nothing, the client's authorization is unknown. */
1154
1155 case DNS_NOMATCH:
1156 case DNS_NODATA:
1157 return t->data.val = CSA_UNKNOWN;
1158
1159 /* We got something! Go on to look at the reply in more detail. */
1160
1161 case DNS_SUCCEED:
1162 break;
1163 }
1164
1165 /* Scan the reply for well-formed CSA SRV records. */
1166
1167 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1168 rr != NULL;
1169 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1170 {
1171 if (rr->type != T_SRV) continue;
1172
1173 /* Extract the numerical SRV fields (p is incremented) */
1174
1175 p = rr->data;
1176 GETSHORT(priority, p);
1177 GETSHORT(weight, p);
1178 GETSHORT(port, p);
1179
1180 DEBUG(D_acl)
1181 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1182
1183 /* Check the CSA version number */
1184
1185 if (priority != 1) continue;
1186
1187 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1188 found by dns_special_lookup() is a parent of the one we asked for), we check
1189 the subdomain assertions in the port field. At the moment there's only one
1190 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1191 SRV records of their own. */
1192
1193 if (found != domain)
1194 {
1195 if (port & 1)
1196 return t->data.val = CSA_FAIL_EXPLICIT;
1197 else
1198 return t->data.val = CSA_UNKNOWN;
1199 }
1200
1201 /* This CSA SRV record refers directly to our domain, so we check the value
1202 in the weight field to work out the domain's authorization. 0 and 1 are
1203 unauthorized; 3 means the client is authorized but we can't check the IP
1204 address in order to authenticate it, so we treat it as unknown; values
1205 greater than 3 are undefined. */
1206
1207 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1208
1209 if (weight > 2) continue;
1210
1211 /* Weight == 2, which means the domain is authorized. We must check that the
1212 client's IP address is listed as one of the SRV target addresses. Save the
1213 target hostname then break to scan the additional data for its addresses. */
1214
1215 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1216 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1217
1218 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1219
1220 break;
1221 }
1222
1223 /* If we didn't break the loop then no appropriate records were found. */
1224
1225 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1226
1227 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1228 A target of "." indicates there are no valid addresses, so the client cannot
1229 be authorized. (This is an odd configuration because weight=2 target=. is
1230 equivalent to weight=1, but we check for it in order to keep load off the
1231 root name servers.) Note that dn_expand() turns "." into "". */
1232
1233 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1234
1235 /* Scan the additional section of the CSA SRV reply for addresses belonging
1236 to the target. If the name server didn't return any additional data (e.g.
1237 because it does not fully support SRV records), we need to do another lookup
1238 to obtain the target addresses; otherwise we have a definitive result. */
1239
1240 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1241 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1242
1243 /* The DNS lookup type corresponds to the IP version used by the client. */
1244
1245 #if HAVE_IPV6
1246 if (Ustrchr(sender_host_address, ':') != NULL)
1247 type = T_AAAA;
1248 else
1249 #endif /* HAVE_IPV6 */
1250 type = T_A;
1251
1252
1253 #if HAVE_IPV6 && defined(SUPPORT_A6)
1254 DNS_LOOKUP_AGAIN:
1255 #endif
1256
1257 switch (dns_lookup(&dnsa, target, type, NULL))
1258 {
1259 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1260
1261 default:
1262 return t->data.val = CSA_DEFER_ADDR;
1263
1264 /* If the query succeeded, scan the addresses and return the result. */
1265
1266 case DNS_SUCCEED:
1267 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1268 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1269 /* else fall through */
1270
1271 /* If the target has no IP addresses, the client cannot have an authorized
1272 IP address. However, if the target site uses A6 records (not AAAA records)
1273 we have to do yet another lookup in order to check them. */
1274
1275 case DNS_NOMATCH:
1276 case DNS_NODATA:
1277
1278 #if HAVE_IPV6 && defined(SUPPORT_A6)
1279 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1280 #endif
1281
1282 return t->data.val = CSA_FAIL_NOADDR;
1283 }
1284 }
1285
1286
1287
1288 /*************************************************
1289 * Handle verification (address & other) *
1290 *************************************************/
1291
1292 /* This function implements the "verify" condition. It is called when
1293 encountered in any ACL, because some tests are almost always permitted. Some
1294 just don't make sense, and always fail (for example, an attempt to test a host
1295 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1296
1297 Arguments:
1298 where where called from
1299 addr the recipient address that the ACL is handling, or NULL
1300 arg the argument of "verify"
1301 user_msgptr pointer for user message
1302 log_msgptr pointer for log message
1303 basic_errno where to put verify errno
1304
1305 Returns: OK verification condition succeeded
1306 FAIL verification failed
1307 DEFER there was a problem verifying
1308 ERROR syntax error
1309 */
1310
1311 static int
1312 acl_verify(int where, address_item *addr, uschar *arg,
1313 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1314 {
1315 int sep = '/';
1316 int callout = -1;
1317 int callout_overall = -1;
1318 int callout_connect = -1;
1319 int verify_options = 0;
1320 int rc;
1321 BOOL verify_header_sender = FALSE;
1322 BOOL defer_ok = FALSE;
1323 BOOL callout_defer_ok = FALSE;
1324 BOOL no_details = FALSE;
1325 address_item *sender_vaddr = NULL;
1326 uschar *verify_sender_address = NULL;
1327 uschar *pm_mailfrom = NULL;
1328 uschar *se_mailfrom = NULL;
1329
1330 /* Some of the verify items have slash-separated options; some do not. Diagnose
1331 an error if options are given for items that don't expect them. This code has
1332 now got very message. Refactoring to use a table would be a good idea one day.
1333 */
1334
1335 uschar *slash = Ustrchr(arg, '/');
1336 uschar *list = arg;
1337 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1338
1339 if (ss == NULL) goto BAD_VERIFY;
1340
1341 /* Handle name/address consistency verification in a separate function. */
1342
1343 if (strcmpic(ss, US"reverse_host_lookup") == 0)
1344 {
1345 if (slash != NULL) goto NO_OPTIONS;
1346 if (sender_host_address == NULL) return OK;
1347 return acl_verify_reverse(user_msgptr, log_msgptr);
1348 }
1349
1350 /* TLS certificate verification is done at STARTTLS time; here we just
1351 test whether it was successful or not. (This is for optional verification; for
1352 mandatory verification, the connection doesn't last this long.) */
1353
1354 if (strcmpic(ss, US"certificate") == 0)
1355 {
1356 if (slash != NULL) goto NO_OPTIONS;
1357 if (tls_certificate_verified) return OK;
1358 *user_msgptr = US"no verified certificate";
1359 return FAIL;
1360 }
1361
1362 /* We can test the result of optional HELO verification */
1363
1364 if (strcmpic(ss, US"helo") == 0)
1365 {
1366 if (slash != NULL) goto NO_OPTIONS;
1367 return helo_verified? OK : FAIL;
1368 }
1369
1370 /* Do Client SMTP Authorization checks in a separate function, and turn the
1371 result code into user-friendly strings. */
1372
1373 if (strcmpic(ss, US"csa") == 0)
1374 {
1375 rc = acl_verify_csa(list);
1376 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1377 csa_reason_string[rc]);
1378 csa_status = csa_status_string[rc];
1379 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1380 return csa_return_code[rc];
1381 }
1382
1383 /* Check that all relevant header lines have the correct syntax. If there is
1384 a syntax error, we return details of the error to the sender if configured to
1385 send out full details. (But a "message" setting on the ACL can override, as
1386 always). */
1387
1388 if (strcmpic(ss, US"header_syntax") == 0)
1389 {
1390 if (slash != NULL) goto NO_OPTIONS;
1391 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP)
1392 {
1393 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1394 "(only possible in ACL for DATA)", acl_wherenames[where]);
1395 return ERROR;
1396 }
1397 rc = verify_check_headers(log_msgptr);
1398 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1399 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1400 return rc;
1401 }
1402
1403
1404 /* The remaining verification tests check recipient and sender addresses,
1405 either from the envelope or from the header. There are a number of
1406 slash-separated options that are common to all of them. */
1407
1408
1409 /* Check that there is at least one verifiable sender address in the relevant
1410 header lines. This can be followed by callout and defer options, just like
1411 sender and recipient. */
1412
1413 if (strcmpic(ss, US"header_sender") == 0)
1414 {
1415 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP)
1416 {
1417 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1418 "(only possible in ACL for DATA)", acl_wherenames[where]);
1419 return ERROR;
1420 }
1421 verify_header_sender = TRUE;
1422 }
1423
1424 /* Otherwise, first item in verify argument must be "sender" or "recipient".
1425 In the case of a sender, this can optionally be followed by an address to use
1426 in place of the actual sender (rare special-case requirement). */
1427
1428 else if (strncmpic(ss, US"sender", 6) == 0)
1429 {
1430 uschar *s = ss + 6;
1431 if (where > ACL_WHERE_NOTSMTP)
1432 {
1433 *log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
1434 "(only possible for MAIL, RCPT, PREDATA, or DATA)",
1435 acl_wherenames[where]);
1436 return ERROR;
1437 }
1438 if (*s == 0)
1439 verify_sender_address = sender_address;
1440 else
1441 {
1442 while (isspace(*s)) s++;
1443 if (*s++ != '=') goto BAD_VERIFY;
1444 while (isspace(*s)) s++;
1445 verify_sender_address = string_copy(s);
1446 }
1447 }
1448 else
1449 {
1450 if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
1451 if (addr == NULL)
1452 {
1453 *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
1454 "(only possible for RCPT)", acl_wherenames[where]);
1455 return ERROR;
1456 }
1457 }
1458
1459 /* Remaining items are optional; they apply to sender and recipient
1460 verification, including "header sender" verification. */
1461
1462 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1463 != NULL)
1464 {
1465 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1466 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1467
1468 /* These two old options are left for backwards compatibility */
1469
1470 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1471 {
1472 callout_defer_ok = TRUE;
1473 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1474 }
1475
1476 else if (strcmpic(ss, US"check_postmaster") == 0)
1477 {
1478 pm_mailfrom = US"";
1479 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1480 }
1481
1482 /* The callout option has a number of sub-options, comma separated */
1483
1484 else if (strncmpic(ss, US"callout", 7) == 0)
1485 {
1486 callout = CALLOUT_TIMEOUT_DEFAULT;
1487 ss += 7;
1488 if (*ss != 0)
1489 {
1490 while (isspace(*ss)) ss++;
1491 if (*ss++ == '=')
1492 {
1493 int optsep = ',';
1494 uschar *opt;
1495 uschar buffer[256];
1496 while (isspace(*ss)) ss++;
1497
1498 /* This callout option handling code has become a mess as new options
1499 have been added in an ad hoc manner. It should be tidied up into some
1500 kind of table-driven thing. */
1501
1502 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1503 != NULL)
1504 {
1505 if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
1506 else if (strcmpic(opt, US"no_cache") == 0)
1507 verify_options |= vopt_callout_no_cache;
1508 else if (strcmpic(opt, US"random") == 0)
1509 verify_options |= vopt_callout_random;
1510 else if (strcmpic(opt, US"use_sender") == 0)
1511 verify_options |= vopt_callout_recipsender;
1512 else if (strcmpic(opt, US"use_postmaster") == 0)
1513 verify_options |= vopt_callout_recippmaster;
1514 else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
1515 else if (strcmpic(opt, US"fullpostmaster") == 0)
1516 {
1517 pm_mailfrom = US"";
1518 verify_options |= vopt_callout_fullpm;
1519 }
1520
1521 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1522 {
1523 if (!verify_header_sender)
1524 {
1525 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1526 "callout option only for verify=header_sender (detected in ACL "
1527 "condition \"%s\")", arg);
1528 return ERROR;
1529 }
1530 opt += 8;
1531 while (isspace(*opt)) opt++;
1532 if (*opt++ != '=')
1533 {
1534 *log_msgptr = string_sprintf("'=' expected after "
1535 "\"mailfrom\" in ACL condition \"%s\"", arg);
1536 return ERROR;
1537 }
1538 while (isspace(*opt)) opt++;
1539 se_mailfrom = string_copy(opt);
1540 }
1541
1542 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1543 {
1544 opt += 19;
1545 while (isspace(*opt)) opt++;
1546 if (*opt++ != '=')
1547 {
1548 *log_msgptr = string_sprintf("'=' expected after "
1549 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1550 return ERROR;
1551 }
1552 while (isspace(*opt)) opt++;
1553 pm_mailfrom = string_copy(opt);
1554 }
1555
1556 else if (strncmpic(opt, US"maxwait", 7) == 0)
1557 {
1558 opt += 7;
1559 while (isspace(*opt)) opt++;
1560 if (*opt++ != '=')
1561 {
1562 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1563 "ACL condition \"%s\"", arg);
1564 return ERROR;
1565 }
1566 while (isspace(*opt)) opt++;
1567 callout_overall = readconf_readtime(opt, 0, FALSE);
1568 if (callout_overall < 0)
1569 {
1570 *log_msgptr = string_sprintf("bad time value in ACL condition "
1571 "\"verify %s\"", arg);
1572 return ERROR;
1573 }
1574 }
1575 else if (strncmpic(opt, US"connect", 7) == 0)
1576 {
1577 opt += 7;
1578 while (isspace(*opt)) opt++;
1579 if (*opt++ != '=')
1580 {
1581 *log_msgptr = string_sprintf("'=' expected after "
1582 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1583 return ERROR;
1584 }
1585 while (isspace(*opt)) opt++;
1586 callout_connect = readconf_readtime(opt, 0, FALSE);
1587 if (callout_connect < 0)
1588 {
1589 *log_msgptr = string_sprintf("bad time value in ACL condition "
1590 "\"verify %s\"", arg);
1591 return ERROR;
1592 }
1593 }
1594 else /* Plain time is callout connect/command timeout */
1595 {
1596 callout = readconf_readtime(opt, 0, FALSE);
1597 if (callout < 0)
1598 {
1599 *log_msgptr = string_sprintf("bad time value in ACL condition "
1600 "\"verify %s\"", arg);
1601 return ERROR;
1602 }
1603 }
1604 }
1605 }
1606 else
1607 {
1608 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1609 "ACL condition \"%s\"", arg);
1610 return ERROR;
1611 }
1612 }
1613 }
1614
1615 /* Option not recognized */
1616
1617 else
1618 {
1619 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1620 "condition \"verify %s\"", ss, arg);
1621 return ERROR;
1622 }
1623 }
1624
1625 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1626 (vopt_callout_recipsender|vopt_callout_recippmaster))
1627 {
1628 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1629 "for a recipient callout";
1630 return ERROR;
1631 }
1632
1633 /* Handle sender-in-header verification. Default the user message to the log
1634 message if giving out verification details. */
1635
1636 if (verify_header_sender)
1637 {
1638 int verrno;
1639 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1640 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1641 &verrno);
1642 if (rc != OK)
1643 {
1644 *basic_errno = verrno;
1645 if (smtp_return_error_details)
1646 {
1647 if (*user_msgptr == NULL && *log_msgptr != NULL)
1648 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1649 if (rc == DEFER) acl_temp_details = TRUE;
1650 }
1651 }
1652 }
1653
1654 /* Handle a sender address. The default is to verify *the* sender address, but
1655 optionally a different address can be given, for special requirements. If the
1656 address is empty, we are dealing with a bounce message that has no sender, so
1657 we cannot do any checking. If the real sender address gets rewritten during
1658 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1659 during message reception.
1660
1661 A list of verified "sender" addresses is kept to try to avoid doing to much
1662 work repetitively when there are multiple recipients in a message and they all
1663 require sender verification. However, when callouts are involved, it gets too
1664 complicated because different recipients may require different callout options.
1665 Therefore, we always do a full sender verify when any kind of callout is
1666 specified. Caching elsewhere, for instance in the DNS resolver and in the
1667 callout handling, should ensure that this is not terribly inefficient. */
1668
1669 else if (verify_sender_address != NULL)
1670 {
1671 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1672 != 0)
1673 {
1674 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1675 "sender verify callout";
1676 return ERROR;
1677 }
1678
1679 sender_vaddr = verify_checked_sender(verify_sender_address);
1680 if (sender_vaddr != NULL && /* Previously checked */
1681 callout <= 0) /* No callout needed this time */
1682 {
1683 /* If the "routed" flag is set, it means that routing worked before, so
1684 this check can give OK (the saved return code value, if set, belongs to a
1685 callout that was done previously). If the "routed" flag is not set, routing
1686 must have failed, so we use the saved return code. */
1687
1688 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1689 {
1690 rc = sender_vaddr->special_action;
1691 *basic_errno = sender_vaddr->basic_errno;
1692 }
1693 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1694 }
1695
1696 /* Do a new verification, and cache the result. The cache is used to avoid
1697 verifying the sender multiple times for multiple RCPTs when callouts are not
1698 specified (see comments above).
1699
1700 The cache is also used on failure to give details in response to the first
1701 RCPT that gets bounced for this reason. However, this can be suppressed by
1702 the no_details option, which sets the flag that says "this detail has already
1703 been sent". The cache normally contains just one address, but there may be
1704 more in esoteric circumstances. */
1705
1706 else
1707 {
1708 BOOL routed = TRUE;
1709 uschar *save_address_data = deliver_address_data;
1710
1711 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1712 if (no_details) setflag(sender_vaddr, af_sverify_told);
1713 if (verify_sender_address[0] != 0)
1714 {
1715 /* If this is the real sender address, save the unrewritten version
1716 for use later in receive. Otherwise, set a flag so that rewriting the
1717 sender in verify_address() does not update sender_address. */
1718
1719 if (verify_sender_address == sender_address)
1720 sender_address_unrewritten = sender_address;
1721 else
1722 verify_options |= vopt_fake_sender;
1723
1724 /* The recipient, qualify, and expn options are never set in
1725 verify_options. */
1726
1727 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1728 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1729
1730 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1731
1732 if (rc == OK)
1733 {
1734 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1735 {
1736 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1737 verify_sender_address, sender_vaddr->address);
1738 }
1739 else
1740 {
1741 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1742 verify_sender_address);
1743 }
1744 }
1745 else *basic_errno = sender_vaddr->basic_errno;
1746 }
1747 else rc = OK; /* Null sender */
1748
1749 /* Cache the result code */
1750
1751 if (routed) setflag(sender_vaddr, af_verify_routed);
1752 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1753 sender_vaddr->special_action = rc;
1754 sender_vaddr->next = sender_verified_list;
1755 sender_verified_list = sender_vaddr;
1756
1757 /* Restore the recipient address data, which might have been clobbered by
1758 the sender verification. */
1759
1760 deliver_address_data = save_address_data;
1761 }
1762
1763 /* Put the sender address_data value into $sender_address_data */
1764
1765 sender_address_data = sender_vaddr->p.address_data;
1766 }
1767
1768 /* A recipient address just gets a straightforward verify; again we must handle
1769 the DEFER overrides. */
1770
1771 else
1772 {
1773 address_item addr2;
1774
1775 /* We must use a copy of the address for verification, because it might
1776 get rewritten. */
1777
1778 addr2 = *addr;
1779 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1780 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1781 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1782
1783 *log_msgptr = addr2.message;
1784 *user_msgptr = (addr2.user_message != NULL)?
1785 addr2.user_message : addr2.message;
1786 *basic_errno = addr2.basic_errno;
1787
1788 /* Make $address_data visible */
1789 deliver_address_data = addr2.p.address_data;
1790 }
1791
1792 /* We have a result from the relevant test. Handle defer overrides first. */
1793
1794 if (rc == DEFER && (defer_ok ||
1795 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1796 {
1797 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1798 defer_ok? "defer_ok" : "callout_defer_ok");
1799 rc = OK;
1800 }
1801
1802 /* If we've failed a sender, set up a recipient message, and point
1803 sender_verified_failed to the address item that actually failed. */
1804
1805 if (rc != OK && verify_sender_address != NULL)
1806 {
1807 if (rc != DEFER)
1808 {
1809 *log_msgptr = *user_msgptr = US"Sender verify failed";
1810 }
1811 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1812 {
1813 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1814 }
1815 else
1816 {
1817 *log_msgptr = US"Could not complete sender verify callout";
1818 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
1819 *log_msgptr;
1820 }
1821
1822 sender_verified_failed = sender_vaddr;
1823 }
1824
1825 /* Verifying an address messes up the values of $domain and $local_part,
1826 so reset them before returning if this is a RCPT ACL. */
1827
1828 if (addr != NULL)
1829 {
1830 deliver_domain = addr->domain;
1831 deliver_localpart = addr->local_part;
1832 }
1833 return rc;
1834
1835 /* Syntax errors in the verify argument come here. */
1836
1837 BAD_VERIFY:
1838 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
1839 "\"helo\", \"header_syntax\", \"header_sender\" or "
1840 "\"reverse_host_lookup\" at start of ACL condition "
1841 "\"verify %s\"", arg);
1842 return ERROR;
1843
1844 /* Options supplied when not allowed come here */
1845
1846 NO_OPTIONS:
1847 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1848 "(this verify item has no options)", arg);
1849 return ERROR;
1850 }
1851
1852
1853
1854
1855 /*************************************************
1856 * Check argument for control= modifier *
1857 *************************************************/
1858
1859 /* Called from acl_check_condition() below
1860
1861 Arguments:
1862 arg the argument string for control=
1863 pptr set to point to the terminating character
1864 where which ACL we are in
1865 log_msgptr for error messages
1866
1867 Returns: CONTROL_xxx value
1868 */
1869
1870 static int
1871 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
1872 {
1873 int len;
1874 control_def *d;
1875
1876 for (d = controls_list;
1877 d < controls_list + sizeof(controls_list)/sizeof(control_def);
1878 d++)
1879 {
1880 len = Ustrlen(d->name);
1881 if (Ustrncmp(d->name, arg, len) == 0) break;
1882 }
1883
1884 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
1885 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
1886 {
1887 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
1888 return CONTROL_ERROR;
1889 }
1890
1891 *pptr = arg + len;
1892 return d->value;
1893 }
1894
1895
1896
1897 /*************************************************
1898 * Handle rate limiting *
1899 *************************************************/
1900
1901 /* Called by acl_check_condition() below to calculate the result
1902 of the ACL ratelimit condition.
1903
1904 Note that the return value might be slightly unexpected: if the
1905 sender's rate is above the limit then the result is OK. This is
1906 similar to the dnslists condition, and is so that you can write
1907 ACL clauses like: defer ratelimit = 15 / 1h
1908
1909 Arguments:
1910 arg the option string for ratelimit=
1911 log_msgptr for error messages
1912
1913 Returns: OK - Sender's rate is above limit
1914 FAIL - Sender's rate is below limit
1915 DEFER - Problem opening ratelimit database
1916 ERROR - Syntax error in options.
1917 */
1918
1919 static int
1920 acl_ratelimit(uschar *arg, uschar **log_msgptr)
1921 {
1922 double limit, period;
1923 uschar *ss, *key;
1924 int sep = '/';
1925 BOOL have_key = FALSE, leaky = FALSE, strict = FALSE;
1926 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
1927 int old_pool, rc;
1928 tree_node **anchor, *t;
1929 open_db dbblock, *dbm;
1930 dbdata_ratelimit *dbd;
1931 struct timeval tv;
1932
1933 /* Parse the first two options and record their values in expansion
1934 variables. These variables allow the configuration to have informative
1935 error messages based on rate limits obtained from a table lookup. */
1936
1937 /* First is the maximum number of messages per period and maximum burst
1938 size, which must be greater than or equal to zero. Zero is useful for
1939 rate measurement as opposed to rate limiting. */
1940
1941 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
1942 if (sender_rate_limit == NULL)
1943 limit = -1.0;
1944 else
1945 {
1946 limit = Ustrtod(sender_rate_limit, &ss);
1947 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
1948 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
1949 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
1950 }
1951 if (limit < 0.0 || *ss != 0)
1952 {
1953 *log_msgptr = string_sprintf("syntax error in argument for "
1954 "\"ratelimit\" condition: \"%s\" is not a positive number",
1955 sender_rate_limit);
1956 return ERROR;
1957 }
1958
1959 /* We use the rest of the argument list following the limit as the
1960 lookup key, because it doesn't make sense to use the same stored data
1961 if the period or options are different. */
1962
1963 key = arg;
1964
1965 /* Second is the rate measurement period and exponential smoothing time
1966 constant. This must be strictly greater than zero, because zero leads to
1967 run-time division errors. */
1968
1969 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
1970 if (sender_rate_period == NULL) period = -1.0;
1971 else period = readconf_readtime(sender_rate_period, 0, FALSE);
1972 if (period <= 0.0)
1973 {
1974 *log_msgptr = string_sprintf("syntax error in argument for "
1975 "\"ratelimit\" condition: \"%s\" is not a time value",
1976 sender_rate_period);
1977 return ERROR;
1978 }
1979
1980 /* Parse the other options. Should we check if the per_* options are being
1981 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
1982
1983 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
1984 != NULL)
1985 {
1986 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
1987 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
1988 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
1989 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
1990 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
1991 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
1992 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
1993 else have_key = TRUE;
1994 }
1995 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
1996 {
1997 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
1998 return ERROR;
1999 }
2000
2001 /* Default option values */
2002 if (!strict) leaky = TRUE;
2003 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
2004
2005 /* If there is no explicit key, use the sender_host_address. If there is no
2006 sender_host_address (e.g. -bs or acl_not_smtp) then we simply omit it. */
2007
2008 if (!have_key && sender_host_address != NULL)
2009 key = string_sprintf("%s / %s", key, sender_host_address);
2010
2011 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2012 limit, period, key);
2013
2014 /* If we are dealing with rate limits per connection, per message, or per byte,
2015 see if we have already computed the rate by looking in the relevant tree. For
2016 per-connection rate limiting, store tree nodes and dbdata in the permanent pool
2017 so that they survive across resets. */
2018
2019 anchor = NULL;
2020 old_pool = store_pool;
2021
2022 if (per_conn)
2023 {
2024 anchor = &ratelimiters_conn;
2025 store_pool = POOL_PERM;
2026 }
2027 if (per_mail || per_byte)
2028 anchor = &ratelimiters_mail;
2029
2030 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2031 {
2032 dbd = t->data.ptr;
2033 /* The following few lines duplicate some of the code below. */
2034 if (dbd->rate < limit) rc = FAIL;
2035 else rc = OK;
2036 store_pool = old_pool;
2037 sender_rate = string_sprintf("%.1f", dbd->rate);
2038 HDEBUG(D_acl)
2039 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2040 return rc;
2041 }
2042
2043 /* We aren't using a pre-computed rate, so get a previously recorded
2044 rate from the database, update it, and write it back. If there's no
2045 previous rate for this key, create one. */
2046
2047 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2048 if (dbm == NULL)
2049 {
2050 store_pool = old_pool;
2051 sender_rate = NULL;
2052 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2053 *log_msgptr = US"ratelimit database not available";
2054 return DEFER;
2055 }
2056 dbd = dbfn_read(dbm, key);
2057
2058 gettimeofday(&tv, NULL);
2059
2060 if (dbd == NULL)
2061 {
2062 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2063 dbd = store_get(sizeof(dbdata_ratelimit));
2064 dbd->time_stamp = tv.tv_sec;
2065 dbd->time_usec = tv.tv_usec;
2066 dbd->rate = 0.0;
2067 }
2068 else
2069 {
2070 /* The smoothed rate is computed using an exponentially weighted moving
2071 average adjusted for variable sampling intervals. The standard EWMA for
2072 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2073 where f() is the measured value and f'() is the smoothed value.
2074
2075 Old data decays out of the smoothed value exponentially, such that data n
2076 samples old is multiplied by a^n. The exponential decay time constant p
2077 is defined such that data p samples old is multiplied by 1/e, which means
2078 that a = exp(-1/p). We can maintain the same time constant for a variable
2079 sampling interval i by using a = exp(-i/p).
2080
2081 The rate we are measuring is messages per period, suitable for directly
2082 comparing with the limit. The average rate between now and the previous
2083 message is period / interval, which we feed into the EWMA as the sample.
2084
2085 It turns out that the number of messages required for the smoothed rate
2086 to reach the limit when they are sent in a burst is equal to the limit.
2087 This can be seen by analysing the value of the smoothed rate after N
2088 messages sent at even intervals. Let k = (1 - a) * p/i
2089
2090 rate_1 = (1 - a) * p/i + a * rate_0
2091 = k + a * rate_0
2092 rate_2 = k + a * rate_1
2093 = k + a * k + a^2 * rate_0
2094 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2095 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2096 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2097 = rate_0 * a^N + p/i * (1 - a^N)
2098
2099 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2100
2101 rate_N = p/i + (rate_0 - p/i) * a^N
2102 a^N = (rate_N - p/i) / (rate_0 - p/i)
2103 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2104 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2105
2106 Numerical analysis of the above equation, setting the computed rate to
2107 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2108 rates, p/i, the number of messages N = limit. So limit serves as both the
2109 maximum rate measured in messages per period, and the maximum number of
2110 messages that can be sent in a fast burst. */
2111
2112 double this_time = (double)tv.tv_sec
2113 + (double)tv.tv_usec / 1000000.0;
2114 double prev_time = (double)dbd->time_stamp
2115 + (double)dbd->time_usec / 1000000.0;
2116 double interval = this_time - prev_time;
2117
2118 double i_over_p = interval / period;
2119 double a = exp(-i_over_p);
2120
2121 /* We must avoid division by zero, and deal gracefully with the clock going
2122 backwards. If we blunder ahead when time is in reverse then the computed
2123 rate will become bogusly huge. Clamp i/p to a very small number instead. */
2124
2125 if (i_over_p <= 0.0) i_over_p = 1e-9;
2126
2127 dbd->time_stamp = tv.tv_sec;
2128 dbd->time_usec = tv.tv_usec;
2129
2130 /* If we are measuring the rate in bytes per period, multiply the
2131 measured rate by the message size. If we don't know the message size
2132 then it's safe to just use a value of zero and let the recorded rate
2133 decay as if nothing happened. */
2134
2135 if (per_byte)
2136 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2137 * (1 - a) / i_over_p + a * dbd->rate;
2138 else
2139 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2140 }
2141
2142 /* Clients sending at the limit are considered to be over the limit. This
2143 matters for edge cases such the first message sent by a client (which gets
2144 the initial rate of 0.0) when the rate limit is zero (i.e. the client should
2145 be completely blocked). */
2146
2147 if (dbd->rate < limit) rc = FAIL;
2148 else rc = OK;
2149
2150 /* Update the state if the rate is low or if we are being strict. If we
2151 are in leaky mode and the sender's rate is too high, we do not update
2152 the recorded rate in order to avoid an over-aggressive sender's retry
2153 rate preventing them from getting any email through. */
2154
2155 if (rc == FAIL || !leaky)
2156 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2157 dbfn_close(dbm);
2158
2159 /* Store the result in the tree for future reference, if necessary. */
2160
2161 if (anchor != NULL)
2162 {
2163 t = store_get(sizeof(tree_node) + Ustrlen(key));
2164 t->data.ptr = dbd;
2165 Ustrcpy(t->name, key);
2166 (void)tree_insertnode(anchor, t);
2167 }
2168
2169 /* We create the formatted version of the sender's rate very late in
2170 order to ensure that it is done using the correct storage pool. */
2171
2172 store_pool = old_pool;
2173 sender_rate = string_sprintf("%.1f", dbd->rate);
2174
2175 HDEBUG(D_acl)
2176 debug_printf("ratelimit computed rate %s\n", sender_rate);
2177
2178 return rc;
2179 }
2180
2181
2182
2183 /*************************************************
2184 * Handle conditions/modifiers on an ACL item *
2185 *************************************************/
2186
2187 /* Called from acl_check() below.
2188
2189 Arguments:
2190 verb ACL verb
2191 cb ACL condition block - if NULL, result is OK
2192 where where called from
2193 addr the address being checked for RCPT, or NULL
2194 level the nesting level
2195 epp pointer to pass back TRUE if "endpass" encountered
2196 (applies only to "accept" and "discard")
2197 user_msgptr user message pointer
2198 log_msgptr log message pointer
2199 basic_errno pointer to where to put verify error
2200
2201 Returns: OK - all conditions are met
2202 DISCARD - an "acl" condition returned DISCARD - only allowed
2203 for "accept" or "discard" verbs
2204 FAIL - at least one condition fails
2205 FAIL_DROP - an "acl" condition returned FAIL_DROP
2206 DEFER - can't tell at the moment (typically, lookup defer,
2207 but can be temporary callout problem)
2208 ERROR - ERROR from nested ACL or expansion failure or other
2209 error
2210 */
2211
2212 static int
2213 acl_check_condition(int verb, acl_condition_block *cb, int where,
2214 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2215 uschar **log_msgptr, int *basic_errno)
2216 {
2217 uschar *user_message = NULL;
2218 uschar *log_message = NULL;
2219 uschar *p;
2220 int rc = OK;
2221 #ifdef WITH_CONTENT_SCAN
2222 int sep = '/';
2223 #endif
2224
2225 for (; cb != NULL; cb = cb->next)
2226 {
2227 uschar *arg;
2228 int control_type;
2229
2230 /* The message and log_message items set up messages to be used in
2231 case of rejection. They are expanded later. */
2232
2233 if (cb->type == ACLC_MESSAGE)
2234 {
2235 user_message = cb->arg;
2236 continue;
2237 }
2238
2239 if (cb->type == ACLC_LOG_MESSAGE)
2240 {
2241 log_message = cb->arg;
2242 continue;
2243 }
2244
2245 /* The endpass "condition" just sets a flag to show it occurred. This is
2246 checked at compile time to be on an "accept" or "discard" item. */
2247
2248 if (cb->type == ACLC_ENDPASS)
2249 {
2250 *epp = TRUE;
2251 continue;
2252 }
2253
2254 /* For other conditions and modifiers, the argument is expanded now for some
2255 of them, but not for all, because expansion happens down in some lower level
2256 checking functions in some cases. */
2257
2258 if (cond_expand_at_top[cb->type])
2259 {
2260 arg = expand_string(cb->arg);
2261 if (arg == NULL)
2262 {
2263 if (expand_string_forcedfail) continue;
2264 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2265 cb->arg, expand_string_message);
2266 return search_find_defer? DEFER : ERROR;
2267 }
2268 }
2269 else arg = cb->arg;
2270
2271 /* Show condition, and expanded condition if it's different */
2272
2273 HDEBUG(D_acl)
2274 {
2275 int lhswidth = 0;
2276 debug_printf("check %s%s %n",
2277 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2278 conditions[cb->type], &lhswidth);
2279
2280 if (cb->type == ACLC_SET)
2281 {
2282 int n = cb->u.varnumber;
2283 int t = (n < ACL_C_MAX)? 'c' : 'm';
2284 if (n >= ACL_C_MAX) n -= ACL_C_MAX;
2285 debug_printf("acl_%c%d ", t, n);
2286 lhswidth += 7;
2287 }
2288
2289 debug_printf("= %s\n", cb->arg);
2290
2291 if (arg != cb->arg)
2292 debug_printf("%.*s= %s\n", lhswidth,
2293 US" ", CS arg);
2294 }
2295
2296 /* Check that this condition makes sense at this time */
2297
2298 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2299 {
2300 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2301 cond_modifiers[cb->type]? "use" : "test",
2302 conditions[cb->type], acl_wherenames[where]);
2303 return ERROR;
2304 }
2305
2306 /* Run the appropriate test for each condition, or take the appropriate
2307 action for the remaining modifiers. */
2308
2309 switch(cb->type)
2310 {
2311 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2312 "discard" verb. */
2313
2314 case ACLC_ACL:
2315 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2316 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2317 {
2318 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2319 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2320 verbs[verb]);
2321 return ERROR;
2322 }
2323 break;
2324
2325 case ACLC_AUTHENTICATED:
2326 rc = (sender_host_authenticated == NULL)? FAIL :
2327 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2328 TRUE, NULL);
2329 break;
2330
2331 #ifdef EXPERIMENTAL_BRIGHTMAIL
2332 case ACLC_BMI_OPTIN:
2333 {
2334 int old_pool = store_pool;
2335 store_pool = POOL_PERM;
2336 bmi_current_optin = string_copy(arg);
2337 store_pool = old_pool;
2338 }
2339 break;
2340 #endif
2341
2342 case ACLC_CONDITION:
2343 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2344 rc = (Uatoi(arg) == 0)? FAIL : OK;
2345 else
2346 rc = (strcmpic(arg, US"no") == 0 ||
2347 strcmpic(arg, US"false") == 0)? FAIL :
2348 (strcmpic(arg, US"yes") == 0 ||
2349 strcmpic(arg, US"true") == 0)? OK : DEFER;
2350 if (rc == DEFER)
2351 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2352 break;
2353
2354 case ACLC_CONTROL:
2355 control_type = decode_control(arg, &p, where, log_msgptr);
2356
2357 /* Check if this control makes sense at this time */
2358
2359 if ((control_forbids[control_type] & (1 << where)) != 0)
2360 {
2361 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2362 controls[control_type], acl_wherenames[where]);
2363 return ERROR;
2364 }
2365
2366 switch(control_type)
2367 {
2368 #ifdef EXPERIMENTAL_BRIGHTMAIL
2369 case CONTROL_BMI_RUN:
2370 bmi_run = 1;
2371 break;
2372 #endif
2373 #ifdef EXPERIMENTAL_DOMAINKEYS
2374 case CONTROL_DK_VERIFY:
2375 dk_do_verify = 1;
2376 break;
2377 #endif
2378 case CONTROL_ERROR:
2379 return ERROR;
2380
2381 case CONTROL_CASEFUL_LOCAL_PART:
2382 deliver_localpart = addr->cc_local_part;
2383 break;
2384
2385 case CONTROL_CASELOWER_LOCAL_PART:
2386 deliver_localpart = addr->lc_local_part;
2387 break;
2388
2389 case CONTROL_ENFORCE_SYNC:
2390 smtp_enforce_sync = TRUE;
2391 break;
2392
2393 case CONTROL_NO_ENFORCE_SYNC:
2394 smtp_enforce_sync = FALSE;
2395 break;
2396
2397 #ifdef WITH_CONTENT_SCAN
2398 case CONTROL_NO_MBOX_UNSPOOL:
2399 no_mbox_unspool = TRUE;
2400 break;
2401 #endif
2402
2403 case CONTROL_NO_MULTILINE:
2404 no_multiline_responses = TRUE;
2405 break;
2406
2407 case CONTROL_FAKEDEFER:
2408 case CONTROL_FAKEREJECT:
2409 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2410 if (*p == '/')
2411 {
2412 uschar *pp = p + 1;
2413 while (*pp != 0) pp++;
2414 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2415 p = pp;
2416 }
2417 else
2418 {
2419 /* Explicitly reset to default string */
2420 fake_response_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legitimate message, it may still be delivered to the target recipient(s).";
2421 }
2422 break;
2423
2424 case CONTROL_FREEZE:
2425 deliver_freeze = TRUE;
2426 deliver_frozen_at = time(NULL);
2427 break;
2428
2429 case CONTROL_QUEUE_ONLY:
2430 queue_only_policy = TRUE;
2431 break;
2432
2433 case CONTROL_SUBMISSION:
2434 originator_name = US"";
2435 submission_mode = TRUE;
2436 while (*p == '/')
2437 {
2438 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2439 {
2440 p += 14;
2441 active_local_sender_retain = TRUE;
2442 active_local_from_check = FALSE;
2443 }
2444 else if (Ustrncmp(p, "/domain=", 8) == 0)
2445 {
2446 uschar *pp = p + 8;
2447 while (*pp != 0 && *pp != '/') pp++;
2448 submission_domain = string_copyn(p+8, pp-p-8);
2449 p = pp;
2450 }
2451 else if (Ustrncmp(p, "/name=", 6) == 0)
2452 {
2453 uschar *pp = p + 6;
2454 while (*pp != 0 && *pp != '/') pp++;
2455 originator_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2456 big_buffer, big_buffer_size));
2457 p = pp;
2458 }
2459 else break;
2460 }
2461 if (*p != 0)
2462 {
2463 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2464 return ERROR;
2465 }
2466 break;
2467 }
2468 break;
2469
2470 #ifdef WITH_CONTENT_SCAN
2471 case ACLC_DECODE:
2472 rc = mime_decode(&arg);
2473 break;
2474 #endif
2475
2476 case ACLC_DELAY:
2477 {
2478 int delay = readconf_readtime(arg, 0, FALSE);
2479 if (delay < 0)
2480 {
2481 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2482 "modifier: \"%s\" is not a time value", arg);
2483 return ERROR;
2484 }
2485 else
2486 {
2487 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2488 delay);
2489 if (host_checking)
2490 {
2491 HDEBUG(D_acl)
2492 debug_printf("delay skipped in -bh checking mode\n");
2493 }
2494
2495 /* It appears to be impossible to detect that a TCP/IP connection has
2496 gone away without reading from it. This means that we cannot shorten
2497 the delay below if the client goes away, because we cannot discover
2498 that the client has closed its end of the connection. (The connection
2499 is actually in a half-closed state, waiting for the server to close its
2500 end.) It would be nice to be able to detect this state, so that the
2501 Exim process is not held up unnecessarily. However, it seems that we
2502 can't. The poll() function does not do the right thing, and in any case
2503 it is not always available.
2504
2505 NOTE: If ever this state of affairs changes, remember that we may be
2506 dealing with stdin/stdout here, in addition to TCP/IP connections.
2507 Whatever is done must work in both cases. To detected the stdin/stdout
2508 case, check for smtp_in or smtp_out being NULL. */
2509
2510 else
2511 {
2512 while (delay > 0) delay = sleep(delay);
2513 }
2514 }
2515 }
2516 break;
2517
2518 #ifdef WITH_OLD_DEMIME
2519 case ACLC_DEMIME:
2520 rc = demime(&arg);
2521 break;
2522 #endif
2523
2524 #ifdef EXPERIMENTAL_DOMAINKEYS
2525 case ACLC_DK_DOMAIN_SOURCE:
2526 if (dk_verify_block == NULL) { rc = FAIL; break; };
2527 /* check header source of domain against given string */
2528 switch (dk_verify_block->address_source) {
2529 case DK_EXIM_ADDRESS_FROM_FROM:
2530 rc = match_isinlist(US"from", &arg, 0, NULL,
2531 NULL, MCL_STRING, TRUE, NULL);
2532 break;
2533 case DK_EXIM_ADDRESS_FROM_SENDER:
2534 rc = match_isinlist(US"sender", &arg, 0, NULL,
2535 NULL, MCL_STRING, TRUE, NULL);
2536 break;
2537 case DK_EXIM_ADDRESS_NONE:
2538 rc = match_isinlist(US"none", &arg, 0, NULL,
2539 NULL, MCL_STRING, TRUE, NULL);
2540 break;
2541 }
2542 break;
2543 case ACLC_DK_POLICY:
2544 if (dk_verify_block == NULL) { rc = FAIL; break; };
2545 /* check policy against given string, default FAIL */
2546 rc = FAIL;
2547 if (dk_verify_block->signsall)
2548 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2549 NULL, MCL_STRING, TRUE, NULL);
2550 if (dk_verify_block->testing)
2551 rc = match_isinlist(US"testing", &arg, 0, NULL,
2552 NULL, MCL_STRING, TRUE, NULL);
2553 break;
2554 case ACLC_DK_SENDER_DOMAINS:
2555 if (dk_verify_block == NULL) { rc = FAIL; break; };
2556 if (dk_verify_block->domain != NULL)
2557 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2558 NULL, MCL_DOMAIN, TRUE, NULL);
2559 else rc = FAIL;
2560 break;
2561 case ACLC_DK_SENDER_LOCAL_PARTS:
2562 if (dk_verify_block == NULL) { rc = FAIL; break; };
2563 if (dk_verify_block->local_part != NULL)
2564 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2565 NULL, MCL_LOCALPART, TRUE, NULL);
2566 else rc = FAIL;
2567 break;
2568 case ACLC_DK_SENDERS:
2569 if (dk_verify_block == NULL) { rc = FAIL; break; };
2570 if (dk_verify_block->address != NULL)
2571 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2572 else rc = FAIL;
2573 break;
2574 case ACLC_DK_STATUS:
2575 if (dk_verify_block == NULL) { rc = FAIL; break; };
2576 if (dk_verify_block->result > 0) {
2577 switch(dk_verify_block->result) {
2578 case DK_EXIM_RESULT_BAD_FORMAT:
2579 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2580 NULL, MCL_STRING, TRUE, NULL);
2581 break;
2582 case DK_EXIM_RESULT_NO_KEY:
2583 rc = match_isinlist(US"no key", &arg, 0, NULL,
2584 NULL, MCL_STRING, TRUE, NULL);
2585 break;
2586 case DK_EXIM_RESULT_NO_SIGNATURE:
2587 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2588 NULL, MCL_STRING, TRUE, NULL);
2589 break;
2590 case DK_EXIM_RESULT_REVOKED:
2591 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2592 NULL, MCL_STRING, TRUE, NULL);
2593 break;
2594 case DK_EXIM_RESULT_NON_PARTICIPANT:
2595 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2596 NULL, MCL_STRING, TRUE, NULL);
2597 break;
2598 case DK_EXIM_RESULT_GOOD:
2599 rc = match_isinlist(US"good", &arg, 0, NULL,
2600 NULL, MCL_STRING, TRUE, NULL);
2601 break;
2602 case DK_EXIM_RESULT_BAD:
2603 rc = match_isinlist(US"bad", &arg, 0, NULL,
2604 NULL, MCL_STRING, TRUE, NULL);
2605 break;
2606 }
2607 }
2608 break;
2609 #endif
2610
2611 case ACLC_DNSLISTS:
2612 rc = verify_check_dnsbl(&arg);
2613 break;
2614
2615 case ACLC_DOMAINS:
2616 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2617 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2618 break;
2619
2620 /* The value in tls_cipher is the full cipher name, for example,
2621 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2622 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2623 what may in practice come out of the SSL library - which at the time of
2624 writing is poorly documented. */
2625
2626 case ACLC_ENCRYPTED:
2627 if (tls_cipher == NULL) rc = FAIL; else
2628 {
2629 uschar *endcipher = NULL;
2630 uschar *cipher = Ustrchr(tls_cipher, ':');
2631 if (cipher == NULL) cipher = tls_cipher; else
2632 {
2633 endcipher = Ustrchr(++cipher, ':');
2634 if (endcipher != NULL) *endcipher = 0;
2635 }
2636 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2637 if (endcipher != NULL) *endcipher = ':';
2638 }
2639 break;
2640
2641 /* Use verify_check_this_host() instead of verify_check_host() so that
2642 we can pass over &host_data to catch any looked up data. Once it has been
2643 set, it retains its value so that it's still there if another ACL verb
2644 comes through here and uses the cache. However, we must put it into
2645 permanent store in case it is also expected to be used in a subsequent
2646 message in the same SMTP connection. */
2647
2648 case ACLC_HOSTS:
2649 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2650 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2651 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2652 break;
2653
2654 case ACLC_LOCAL_PARTS:
2655 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2656 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2657 &deliver_localpart_data);
2658 break;
2659
2660 case ACLC_LOGWRITE:
2661 {
2662 int logbits = 0;
2663 uschar *s = arg;
2664 if (*s == ':')
2665 {
2666 s++;
2667 while (*s != ':')
2668 {
2669 if (Ustrncmp(s, "main", 4) == 0)
2670 { logbits |= LOG_MAIN; s += 4; }
2671 else if (Ustrncmp(s, "panic", 5) == 0)
2672 { logbits |= LOG_PANIC; s += 5; }
2673 else if (Ustrncmp(s, "reject", 6) == 0)
2674 { logbits |= LOG_REJECT; s += 6; }
2675 else
2676 {
2677 logbits = LOG_MAIN|LOG_PANIC;
2678 s = string_sprintf(":unknown log name in \"%s\" in "
2679 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2680 }
2681 if (*s == ',') s++;
2682 }
2683 s++;
2684 }
2685 while (isspace(*s)) s++;
2686 if (logbits == 0) logbits = LOG_MAIN;
2687 log_write(0, logbits, "%s", string_printing(s));
2688 }
2689 break;
2690
2691 #ifdef WITH_CONTENT_SCAN
2692 case ACLC_MALWARE:
2693 {
2694 /* Seperate the regular expression and any optional parameters. */
2695 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2696 /* Run the malware backend. */
2697 rc = malware(&ss);
2698 /* Modify return code based upon the existance of options. */
2699 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2700 != NULL) {
2701 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2702 {
2703 /* FAIL so that the message is passed to the next ACL */
2704 rc = FAIL;
2705 }
2706 }
2707 }
2708 break;
2709
2710 case ACLC_MIME_REGEX:
2711 rc = mime_regex(&arg);
2712 break;
2713 #endif
2714
2715 case ACLC_RATELIMIT:
2716 rc = acl_ratelimit(arg, log_msgptr);
2717 break;
2718
2719 case ACLC_RECIPIENTS:
2720 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
2721 &recipient_data);
2722 break;
2723
2724 #ifdef WITH_CONTENT_SCAN
2725 case ACLC_REGEX:
2726 rc = regex(&arg);
2727 break;
2728 #endif
2729
2730 case ACLC_SENDER_DOMAINS:
2731 {
2732 uschar *sdomain;
2733 sdomain = Ustrrchr(sender_address, '@');
2734 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
2735 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
2736 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
2737 }
2738 break;
2739
2740 case ACLC_SENDERS:
2741 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
2742 sender_address_cache, -1, 0, &sender_data);
2743 break;
2744
2745 /* Connection variables must persist forever */
2746
2747 case ACLC_SET:
2748 {
2749 int old_pool = store_pool;
2750 if (cb->u.varnumber < ACL_C_MAX) store_pool = POOL_PERM;
2751 acl_var[cb->u.varnumber] = string_copy(arg);
2752 store_pool = old_pool;
2753 }
2754 break;
2755
2756 #ifdef WITH_CONTENT_SCAN
2757 case ACLC_SPAM:
2758 {
2759 /* Seperate the regular expression and any optional parameters. */
2760 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2761 /* Run the spam backend. */
2762 rc = spam(&ss);
2763 /* Modify return code based upon the existance of options. */
2764 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2765 != NULL) {
2766 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2767 {
2768 /* FAIL so that the message is passed to the next ACL */
2769 rc = FAIL;
2770 }
2771 }
2772 }
2773 break;
2774 #endif
2775
2776 #ifdef EXPERIMENTAL_SPF
2777 case ACLC_SPF:
2778 rc = spf_process(&arg, sender_address);
2779 break;
2780 #endif
2781
2782 /* If the verb is WARN, discard any user message from verification, because
2783 such messages are SMTP responses, not header additions. The latter come
2784 only from explicit "message" modifiers. However, put the user message into
2785 $acl_verify_message so it can be used in subsequent conditions or modifiers
2786 (until something changes it). */
2787
2788 case ACLC_VERIFY:
2789 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
2790 acl_verify_message = *user_msgptr;
2791 if (verb == ACL_WARN) *user_msgptr = NULL;
2792 break;
2793
2794 default:
2795 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
2796 "condition %d", cb->type);
2797 break;
2798 }
2799
2800 /* If a condition was negated, invert OK/FAIL. */
2801
2802 if (!cond_modifiers[cb->type] && cb->u.negated)
2803 {
2804 if (rc == OK) rc = FAIL;
2805 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
2806 }
2807
2808 if (rc != OK) break; /* Conditions loop */
2809 }
2810
2811
2812 /* If the result is the one for which "message" and/or "log_message" are used,
2813 handle the values of these options. Most verbs have but a single return for
2814 which the messages are relevant, but for "discard", it's useful to have the log
2815 message both when it succeeds and when it fails. Also, for an "accept" that
2816 appears in a QUIT ACL, we want to handle the user message. Since only "accept"
2817 and "warn" are permitted in that ACL, we don't need to test the verb.
2818
2819 These modifiers act in different ways:
2820
2821 "message" is a user message that will be included in an SMTP response. Unless
2822 it is empty, it overrides any previously set user message.
2823
2824 "log_message" is a non-user message, and it adds to any existing non-user
2825 message that is already set.
2826
2827 If there isn't a log message set, we make it the same as the user message. */
2828
2829 if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] ||
2830 (verb == ACL_DISCARD && rc == OK) ||
2831 (where == ACL_WHERE_QUIT))
2832 {
2833 uschar *expmessage;
2834
2835 /* If the verb is "warn", messages generated by conditions (verification or
2836 nested ACLs) are discarded. Only messages specified at this level are used.
2837 However, the value of an existing message is available in $acl_verify_message
2838 during expansions. */
2839
2840 uschar *old_user_msgptr = *user_msgptr;
2841 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
2842
2843 if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL;
2844
2845 if (user_message != NULL)
2846 {
2847 acl_verify_message = old_user_msgptr;
2848 expmessage = expand_string(user_message);
2849 if (expmessage == NULL)
2850 {
2851 if (!expand_string_forcedfail)
2852 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2853 user_message, expand_string_message);
2854 }
2855 else if (expmessage[0] != 0) *user_msgptr = expmessage;
2856 }
2857
2858 if (log_message != NULL)
2859 {
2860 acl_verify_message = old_log_msgptr;
2861 expmessage = expand_string(log_message);
2862 if (expmessage == NULL)
2863 {
2864 if (!expand_string_forcedfail)
2865 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2866 log_message, expand_string_message);
2867 }
2868 else if (expmessage[0] != 0)
2869 {
2870 *log_msgptr = (*log_msgptr == NULL)? expmessage :
2871 string_sprintf("%s: %s", expmessage, *log_msgptr);
2872 }
2873 }
2874
2875 /* If no log message, default it to the user message */
2876
2877 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
2878 }
2879
2880 acl_verify_message = NULL;
2881 return rc;
2882 }
2883
2884
2885
2886
2887
2888 /*************************************************
2889 * Get line from a literal ACL *
2890 *************************************************/
2891
2892 /* This function is passed to acl_read() in order to extract individual lines
2893 of a literal ACL, which we access via static pointers. We can destroy the
2894 contents because this is called only once (the compiled ACL is remembered).
2895
2896 This code is intended to treat the data in the same way as lines in the main
2897 Exim configuration file. That is:
2898
2899 . Leading spaces are ignored.
2900
2901 . A \ at the end of a line is a continuation - trailing spaces after the \
2902 are permitted (this is because I don't believe in making invisible things
2903 significant). Leading spaces on the continued part of a line are ignored.
2904
2905 . Physical lines starting (significantly) with # are totally ignored, and
2906 may appear within a sequence of backslash-continued lines.
2907
2908 . Blank lines are ignored, but will end a sequence of continuations.
2909
2910 Arguments: none
2911 Returns: a pointer to the next line
2912 */
2913
2914
2915 static uschar *acl_text; /* Current pointer in the text */
2916 static uschar *acl_text_end; /* Points one past the terminating '0' */
2917
2918
2919 static uschar *
2920 acl_getline(void)
2921 {
2922 uschar *yield;
2923
2924 /* This loop handles leading blank lines and comments. */
2925
2926 for(;;)
2927 {
2928 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
2929 if (*acl_text == 0) return NULL; /* No more data */
2930 yield = acl_text; /* Potential data line */
2931
2932 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2933
2934 /* If we hit the end before a newline, we have the whole logical line. If
2935 it's a comment, there's no more data to be given. Otherwise, yield it. */
2936
2937 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
2938
2939 /* After reaching a newline, end this loop if the physical line does not
2940 start with '#'. If it does, it's a comment, and the loop continues. */
2941
2942 if (*yield != '#') break;
2943 }
2944
2945 /* This loop handles continuations. We know we have some real data, ending in
2946 newline. See if there is a continuation marker at the end (ignoring trailing
2947 white space). We know that *yield is not white space, so no need to test for
2948 cont > yield in the backwards scanning loop. */
2949
2950 for(;;)
2951 {
2952 uschar *cont;
2953 for (cont = acl_text - 1; isspace(*cont); cont--);
2954
2955 /* If no continuation follows, we are done. Mark the end of the line and
2956 return it. */
2957
2958 if (*cont != '\\')
2959 {
2960 *acl_text++ = 0;
2961 return yield;
2962 }
2963
2964 /* We have encountered a continuation. Skip over whitespace at the start of
2965 the next line, and indeed the whole of the next line or lines if they are
2966 comment lines. */
2967
2968 for (;;)
2969 {
2970 while (*(++acl_text) == ' ' || *acl_text == '\t');
2971 if (*acl_text != '#') break;
2972 while (*(++acl_text) != 0 && *acl_text != '\n');
2973 }
2974
2975 /* We have the start of a continuation line. Move all the rest of the data
2976 to join onto the previous line, and then find its end. If the end is not a
2977 newline, we are done. Otherwise loop to look for another continuation. */
2978
2979 memmove(cont, acl_text, acl_text_end - acl_text);
2980 acl_text_end -= acl_text - cont;
2981 acl_text = cont;
2982 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2983 if (*acl_text == 0) return yield;
2984 }
2985
2986 /* Control does not reach here */
2987 }
2988
2989
2990
2991
2992
2993 /*************************************************
2994 * Check access using an ACL *
2995 *************************************************/
2996
2997 /* This function is called from address_check. It may recurse via
2998 acl_check_condition() - hence the use of a level to stop looping. The ACL is
2999 passed as a string which is expanded. A forced failure implies no access check
3000 is required. If the result is a single word, it is taken as the name of an ACL
3001 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3002 text, complete with newlines, and parsed as such. In both cases, the ACL check
3003 is then run. This function uses an auxiliary function for acl_read() to call
3004 for reading individual lines of a literal ACL. This is acl_getline(), which
3005 appears immediately above.
3006
3007 Arguments:
3008 where where called from
3009 addr address item when called from RCPT; otherwise NULL
3010 s the input string; NULL is the same as an empty ACL => DENY
3011 level the nesting level
3012 user_msgptr where to put a user error (for SMTP response)
3013 log_msgptr where to put a logging message (not for SMTP response)
3014
3015 Returns: OK access is granted
3016 DISCARD access is apparently granted...
3017 FAIL access is denied
3018 FAIL_DROP access is denied; drop the connection
3019 DEFER can't tell at the moment
3020 ERROR disaster
3021 */
3022
3023 static int
3024 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3025 uschar **user_msgptr, uschar **log_msgptr)
3026 {
3027 int fd = -1;
3028 acl_block *acl = NULL;
3029 uschar *acl_name = US"inline ACL";
3030 uschar *ss;
3031
3032 /* Catch configuration loops */
3033
3034 if (level > 20)
3035 {
3036 *log_msgptr = US"ACL nested too deep: possible loop";
3037 return ERROR;
3038 }
3039
3040 if (s == NULL)
3041 {
3042 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3043 return FAIL;
3044 }
3045
3046 /* At top level, we expand the incoming string. At lower levels, it has already
3047 been expanded as part of condition processing. */
3048
3049 if (level == 0)
3050 {
3051 ss = expand_string(s);
3052 if (ss == NULL)
3053 {
3054 if (expand_string_forcedfail) return OK;
3055 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3056 expand_string_message);
3057 return ERROR;
3058 }
3059 }
3060 else ss = s;
3061
3062 while (isspace(*ss))ss++;
3063
3064 /* If we can't find a named ACL, the default is to parse it as an inline one.
3065 (Unless it begins with a slash; non-existent files give rise to an error.) */
3066
3067 acl_text = ss;
3068
3069 /* Handle the case of a string that does not contain any spaces. Look for a
3070 named ACL among those read from the configuration, or a previously read file.
3071 It is possible that the pointer to the ACL is NULL if the configuration
3072 contains a name with no data. If not found, and the text begins with '/',
3073 read an ACL from a file, and save it so it can be re-used. */
3074
3075 if (Ustrchr(ss, ' ') == NULL)
3076 {
3077 tree_node *t = tree_search(acl_anchor, ss);
3078 if (t != NULL)
3079 {
3080 acl = (acl_block *)(t->data.ptr);
3081 if (acl == NULL)
3082 {
3083 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3084 return FAIL;
3085 }
3086 acl_name = string_sprintf("ACL \"%s\"", ss);
3087 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3088 }
3089
3090 else if (*ss == '/')
3091 {
3092 struct stat statbuf;
3093 fd = Uopen(ss, O_RDONLY, 0);
3094 if (fd < 0)
3095 {
3096 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3097 strerror(errno));
3098 return ERROR;
3099 }
3100
3101 if (fstat(fd, &statbuf) != 0)
3102 {
3103 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3104 strerror(errno));
3105 return ERROR;
3106 }
3107
3108 acl_text = store_get(statbuf.st_size + 1);
3109 acl_text_end = acl_text + statbuf.st_size + 1;
3110
3111 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3112 {
3113 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3114 ss, strerror(errno));
3115 return ERROR;
3116 }
3117 acl_text[statbuf.st_size] = 0;
3118 close(fd);
3119
3120 acl_name = string_sprintf("ACL \"%s\"", ss);
3121 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3122 }
3123 }
3124
3125 /* Parse an ACL that is still in text form. If it came from a file, remember it
3126 in the ACL tree, having read it into the POOL_PERM store pool so that it
3127 persists between multiple messages. */
3128
3129 if (acl == NULL)
3130 {
3131 int old_pool = store_pool;
3132 if (fd >= 0) store_pool = POOL_PERM;
3133 acl = acl_read(acl_getline, log_msgptr);
3134 store_pool = old_pool;
3135 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3136 if (fd >= 0)
3137 {
3138 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3139 Ustrcpy(t->name, ss);
3140 t->data.ptr = acl;
3141 (void)tree_insertnode(&acl_anchor, t);
3142 }
3143 }
3144
3145 /* Now we have an ACL to use. It's possible it may be NULL. */
3146
3147 while (acl != NULL)
3148 {
3149 int cond;
3150 int basic_errno = 0;
3151 BOOL endpass_seen = FALSE;
3152
3153 *log_msgptr = *user_msgptr = NULL;
3154 acl_temp_details = FALSE;
3155
3156 if (where == ACL_WHERE_QUIT &&
3157 acl->verb != ACL_ACCEPT &&
3158 acl->verb != ACL_WARN)
3159 {
3160 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3161 verbs[acl->verb]);
3162 return ERROR;
3163 }
3164
3165 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3166
3167 /* Clear out any search error message from a previous check before testing
3168 this condition. */
3169
3170 search_error_message = NULL;
3171 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3172 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3173
3174 /* Handle special returns: DEFER causes a return except on a WARN verb;
3175 ERROR always causes a return. */
3176
3177 switch (cond)
3178 {
3179 case DEFER:
3180 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3181 if (basic_errno != ERRNO_CALLOUTDEFER)
3182 {
3183 if (search_error_message != NULL && *search_error_message != 0)
3184 *log_msgptr = search_error_message;
3185 if (smtp_return_error_details) acl_temp_details = TRUE;
3186 }
3187 else
3188 {
3189 acl_temp_details = TRUE;
3190 }
3191 if (acl->verb != ACL_WARN) return DEFER;
3192 break;
3193
3194 default: /* Paranoia */
3195 case ERROR:
3196 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3197 return ERROR;
3198
3199 case OK:
3200 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3201 verbs[acl->verb]);
3202 break;
3203
3204 case FAIL:
3205 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3206 break;
3207
3208 /* DISCARD and DROP can happen only from a nested ACL condition, and
3209 DISCARD can happen only for an "accept" or "discard" verb. */
3210
3211 case DISCARD:
3212 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3213 verbs[acl->verb]);
3214 break;
3215
3216 case FAIL_DROP:
3217 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3218 verbs[acl->verb]);
3219 break;
3220 }
3221
3222 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3223 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3224 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3225
3226 switch(acl->verb)
3227 {
3228 case ACL_ACCEPT:
3229 if (cond == OK || cond == DISCARD) return cond;
3230 if (endpass_seen)
3231 {
3232 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3233 return cond;
3234 }
3235 break;
3236
3237 case ACL_DEFER:
3238 if (cond == OK)
3239 {
3240 acl_temp_details = TRUE;
3241 return DEFER;
3242 }
3243 break;
3244
3245 case ACL_DENY:
3246 if (cond == OK) return FAIL;
3247 break;
3248
3249 case ACL_DISCARD:
3250 if (cond == OK || cond == DISCARD) return DISCARD;
3251 if (endpass_seen)
3252 {
3253 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3254 return cond;
3255 }
3256 break;
3257
3258 case ACL_DROP:
3259 if (cond == OK) return FAIL_DROP;
3260 break;
3261
3262 case ACL_REQUIRE:
3263 if (cond != OK) return cond;
3264 break;
3265
3266 case ACL_WARN:
3267 if (cond == OK)
3268 acl_warn(where, *user_msgptr, *log_msgptr);
3269 else if (cond == DEFER)
3270 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3271 "condition test deferred%s%s", host_and_ident(TRUE),
3272 (*log_msgptr == NULL)? US"" : US": ",
3273 (*log_msgptr == NULL)? US"" : *log_msgptr);
3274 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3275 break;
3276
3277 default:
3278 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3279 acl->verb);
3280 break;
3281 }
3282
3283 /* Pass to the next ACL item */
3284
3285 acl = acl->next;
3286 }
3287
3288 /* We have reached the end of the ACL. This is an implicit DENY. */
3289
3290 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3291 return FAIL;
3292 }
3293
3294
3295 /*************************************************
3296 * Check access using an ACL *
3297 *************************************************/
3298
3299 /* This is the external interface for ACL checks. It sets up an address and the
3300 expansions for $domain and $local_part when called after RCPT, then calls
3301 acl_check_internal() to do the actual work.
3302
3303 Arguments:
3304 where ACL_WHERE_xxxx indicating where called from
3305 data_string RCPT address, or SMTP command argument, or NULL
3306 s the input string; NULL is the same as an empty ACL => DENY
3307 user_msgptr where to put a user error (for SMTP response)
3308 log_msgptr where to put a logging message (not for SMTP response)
3309
3310 Returns: OK access is granted by an ACCEPT verb
3311 DISCARD access is granted by a DISCARD verb
3312 FAIL access is denied
3313 FAIL_DROP access is denied; drop the connection
3314 DEFER can't tell at the moment
3315 ERROR disaster
3316 */
3317
3318 int
3319 acl_check(int where, uschar *data_string, uschar *s, uschar **user_msgptr,
3320 uschar **log_msgptr)
3321 {
3322 int rc;
3323 address_item adb;
3324 address_item *addr;
3325
3326 *user_msgptr = *log_msgptr = NULL;
3327 sender_verified_failed = NULL;
3328
3329 if (where == ACL_WHERE_RCPT)
3330 {
3331 adb = address_defaults;
3332 addr = &adb;
3333 addr->address = data_string;
3334 if (deliver_split_address(addr) == DEFER)
3335 {
3336 *log_msgptr = US"defer in percent_hack_domains check";
3337 return DEFER;
3338 }
3339 deliver_domain = addr->domain;
3340 deliver_localpart = addr->local_part;
3341 }
3342 else
3343 {
3344 addr = NULL;
3345 smtp_command_argument = data_string;
3346 }
3347
3348 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3349
3350 smtp_command_argument = deliver_domain =
3351 deliver_localpart = deliver_address_data = sender_address_data = NULL;
3352
3353 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3354 ACL, which is really in the middle of an SMTP command. */
3355
3356 if (rc == DISCARD)
3357 {
3358 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3359 {
3360 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3361 "ACL", acl_wherenames[where]);
3362 return ERROR;
3363 }
3364 return DISCARD;
3365 }
3366
3367 /* A DROP response is not permitted from MAILAUTH */
3368
3369 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3370 {
3371 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3372 "ACL", acl_wherenames[where]);
3373 return ERROR;
3374 }
3375
3376 /* Before giving an error response, take a look at the length of any user
3377 message, and split it up into multiple lines if possible. */
3378
3379 if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75)
3380 {
3381 uschar *s = *user_msgptr = string_copy(*user_msgptr);
3382 uschar *ss = s;
3383
3384 for (;;)
3385 {
3386 int i = 0;
3387 while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++;
3388 if (*ss == 0) break;
3389 if (*ss == '\n')
3390 s = ++ss;
3391 else
3392 {
3393 uschar *t = ss + 1;
3394 uschar *tt = NULL;
3395 while (--t > s + 35)
3396 {
3397 if (*t == ' ')
3398 {
3399 if (t[-1] == ':') { tt = t; break; }
3400 if (tt == NULL) tt = t;
3401 }
3402 }
3403
3404 if (tt == NULL) /* Can't split behind - try ahead */
3405 {
3406 t = ss + 1;
3407 while (*t != 0)
3408 {
3409 if (*t == ' ' || *t == '\n')
3410 { tt = t; break; }
3411 t++;
3412 }
3413 }
3414
3415 if (tt == NULL) break; /* Can't find anywhere to split */
3416 *tt = '\n';
3417 s = ss = tt+1;
3418 }
3419 }
3420 }
3421
3422 return rc;
3423 }
3424
3425 /* End of acl.c */