Add the ratelimit ACL condition. This is mostly reasonably self-contained
[exim.git] / src / src / acl.c
1 /* $Cambridge: exim/src/src/acl.c,v 1.34 2005/05/23 16:58:56 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
1516 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1517 {
1518 if (!verify_header_sender)
1519 {
1520 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1521 "callout option only for verify=header_sender (detected in ACL "
1522 "condition \"%s\")", arg);
1523 return ERROR;
1524 }
1525 opt += 8;
1526 while (isspace(*opt)) opt++;
1527 if (*opt++ != '=')
1528 {
1529 *log_msgptr = string_sprintf("'=' expected after "
1530 "\"mailfrom\" in ACL condition \"%s\"", arg);
1531 return ERROR;
1532 }
1533 while (isspace(*opt)) opt++;
1534 se_mailfrom = string_copy(opt);
1535 }
1536
1537 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1538 {
1539 opt += 19;
1540 while (isspace(*opt)) opt++;
1541 if (*opt++ != '=')
1542 {
1543 *log_msgptr = string_sprintf("'=' expected after "
1544 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1545 return ERROR;
1546 }
1547 while (isspace(*opt)) opt++;
1548 pm_mailfrom = string_copy(opt);
1549 }
1550
1551 else if (strncmpic(opt, US"maxwait", 7) == 0)
1552 {
1553 opt += 7;
1554 while (isspace(*opt)) opt++;
1555 if (*opt++ != '=')
1556 {
1557 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1558 "ACL condition \"%s\"", arg);
1559 return ERROR;
1560 }
1561 while (isspace(*opt)) opt++;
1562 callout_overall = readconf_readtime(opt, 0, FALSE);
1563 if (callout_overall < 0)
1564 {
1565 *log_msgptr = string_sprintf("bad time value in ACL condition "
1566 "\"verify %s\"", arg);
1567 return ERROR;
1568 }
1569 }
1570 else if (strncmpic(opt, US"connect", 7) == 0)
1571 {
1572 opt += 7;
1573 while (isspace(*opt)) opt++;
1574 if (*opt++ != '=')
1575 {
1576 *log_msgptr = string_sprintf("'=' expected after "
1577 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1578 return ERROR;
1579 }
1580 while (isspace(*opt)) opt++;
1581 callout_connect = readconf_readtime(opt, 0, FALSE);
1582 if (callout_connect < 0)
1583 {
1584 *log_msgptr = string_sprintf("bad time value in ACL condition "
1585 "\"verify %s\"", arg);
1586 return ERROR;
1587 }
1588 }
1589 else /* Plain time is callout connect/command timeout */
1590 {
1591 callout = readconf_readtime(opt, 0, FALSE);
1592 if (callout < 0)
1593 {
1594 *log_msgptr = string_sprintf("bad time value in ACL condition "
1595 "\"verify %s\"", arg);
1596 return ERROR;
1597 }
1598 }
1599 }
1600 }
1601 else
1602 {
1603 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1604 "ACL condition \"%s\"", arg);
1605 return ERROR;
1606 }
1607 }
1608 }
1609
1610 /* Option not recognized */
1611
1612 else
1613 {
1614 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1615 "condition \"verify %s\"", ss, arg);
1616 return ERROR;
1617 }
1618 }
1619
1620 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1621 (vopt_callout_recipsender|vopt_callout_recippmaster))
1622 {
1623 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1624 "for a recipient callout";
1625 return ERROR;
1626 }
1627
1628 /* Handle sender-in-header verification. Default the user message to the log
1629 message if giving out verification details. */
1630
1631 if (verify_header_sender)
1632 {
1633 int verrno;
1634 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1635 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1636 &verrno);
1637 if (rc != OK)
1638 {
1639 *basic_errno = verrno;
1640 if (smtp_return_error_details)
1641 {
1642 if (*user_msgptr == NULL && *log_msgptr != NULL)
1643 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1644 if (rc == DEFER) acl_temp_details = TRUE;
1645 }
1646 }
1647 }
1648
1649 /* Handle a sender address. The default is to verify *the* sender address, but
1650 optionally a different address can be given, for special requirements. If the
1651 address is empty, we are dealing with a bounce message that has no sender, so
1652 we cannot do any checking. If the real sender address gets rewritten during
1653 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1654 during message reception.
1655
1656 A list of verified "sender" addresses is kept to try to avoid doing to much
1657 work repetitively when there are multiple recipients in a message and they all
1658 require sender verification. However, when callouts are involved, it gets too
1659 complicated because different recipients may require different callout options.
1660 Therefore, we always do a full sender verify when any kind of callout is
1661 specified. Caching elsewhere, for instance in the DNS resolver and in the
1662 callout handling, should ensure that this is not terribly inefficient. */
1663
1664 else if (verify_sender_address != NULL)
1665 {
1666 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1667 != 0)
1668 {
1669 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1670 "sender verify callout";
1671 return ERROR;
1672 }
1673
1674 sender_vaddr = verify_checked_sender(verify_sender_address);
1675 if (sender_vaddr != NULL && /* Previously checked */
1676 callout <= 0) /* No callout needed this time */
1677 {
1678 /* If the "routed" flag is set, it means that routing worked before, so
1679 this check can give OK (the saved return code value, if set, belongs to a
1680 callout that was done previously). If the "routed" flag is not set, routing
1681 must have failed, so we use the saved return code. */
1682
1683 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1684 {
1685 rc = sender_vaddr->special_action;
1686 *basic_errno = sender_vaddr->basic_errno;
1687 }
1688 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1689 }
1690
1691 /* Do a new verification, and cache the result. The cache is used to avoid
1692 verifying the sender multiple times for multiple RCPTs when callouts are not
1693 specified (see comments above).
1694
1695 The cache is also used on failure to give details in response to the first
1696 RCPT that gets bounced for this reason. However, this can be suppressed by
1697 the no_details option, which sets the flag that says "this detail has already
1698 been sent". The cache normally contains just one address, but there may be
1699 more in esoteric circumstances. */
1700
1701 else
1702 {
1703 BOOL routed = TRUE;
1704 uschar *save_address_data = deliver_address_data;
1705
1706 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1707 if (no_details) setflag(sender_vaddr, af_sverify_told);
1708 if (verify_sender_address[0] != 0)
1709 {
1710 /* If this is the real sender address, save the unrewritten version
1711 for use later in receive. Otherwise, set a flag so that rewriting the
1712 sender in verify_address() does not update sender_address. */
1713
1714 if (verify_sender_address == sender_address)
1715 sender_address_unrewritten = sender_address;
1716 else
1717 verify_options |= vopt_fake_sender;
1718
1719 /* The recipient, qualify, and expn options are never set in
1720 verify_options. */
1721
1722 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1723 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1724
1725 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1726
1727 if (rc == OK)
1728 {
1729 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1730 {
1731 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1732 verify_sender_address, sender_vaddr->address);
1733 }
1734 else
1735 {
1736 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1737 verify_sender_address);
1738 }
1739 }
1740 else *basic_errno = sender_vaddr->basic_errno;
1741 }
1742 else rc = OK; /* Null sender */
1743
1744 /* Cache the result code */
1745
1746 if (routed) setflag(sender_vaddr, af_verify_routed);
1747 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1748 sender_vaddr->special_action = rc;
1749 sender_vaddr->next = sender_verified_list;
1750 sender_verified_list = sender_vaddr;
1751
1752 /* Restore the recipient address data, which might have been clobbered by
1753 the sender verification. */
1754
1755 deliver_address_data = save_address_data;
1756 }
1757
1758 /* Put the sender address_data value into $sender_address_data */
1759
1760 sender_address_data = sender_vaddr->p.address_data;
1761 }
1762
1763 /* A recipient address just gets a straightforward verify; again we must handle
1764 the DEFER overrides. */
1765
1766 else
1767 {
1768 address_item addr2;
1769
1770 /* We must use a copy of the address for verification, because it might
1771 get rewritten. */
1772
1773 addr2 = *addr;
1774 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1775 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1776 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1777
1778 *log_msgptr = addr2.message;
1779 *user_msgptr = (addr2.user_message != NULL)?
1780 addr2.user_message : addr2.message;
1781 *basic_errno = addr2.basic_errno;
1782
1783 /* Make $address_data visible */
1784 deliver_address_data = addr2.p.address_data;
1785 }
1786
1787 /* We have a result from the relevant test. Handle defer overrides first. */
1788
1789 if (rc == DEFER && (defer_ok ||
1790 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1791 {
1792 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1793 defer_ok? "defer_ok" : "callout_defer_ok");
1794 rc = OK;
1795 }
1796
1797 /* If we've failed a sender, set up a recipient message, and point
1798 sender_verified_failed to the address item that actually failed. */
1799
1800 if (rc != OK && verify_sender_address != NULL)
1801 {
1802 if (rc != DEFER)
1803 {
1804 *log_msgptr = *user_msgptr = US"Sender verify failed";
1805 }
1806 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1807 {
1808 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1809 }
1810 else
1811 {
1812 *log_msgptr = US"Could not complete sender verify callout";
1813 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
1814 *log_msgptr;
1815 }
1816
1817 sender_verified_failed = sender_vaddr;
1818 }
1819
1820 /* Verifying an address messes up the values of $domain and $local_part,
1821 so reset them before returning if this is a RCPT ACL. */
1822
1823 if (addr != NULL)
1824 {
1825 deliver_domain = addr->domain;
1826 deliver_localpart = addr->local_part;
1827 }
1828 return rc;
1829
1830 /* Syntax errors in the verify argument come here. */
1831
1832 BAD_VERIFY:
1833 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
1834 "\"helo\", \"header_syntax\", \"header_sender\" or "
1835 "\"reverse_host_lookup\" at start of ACL condition "
1836 "\"verify %s\"", arg);
1837 return ERROR;
1838
1839 /* Options supplied when not allowed come here */
1840
1841 NO_OPTIONS:
1842 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1843 "(this verify item has no options)", arg);
1844 return ERROR;
1845 }
1846
1847
1848
1849
1850 /*************************************************
1851 * Check argument for control= modifier *
1852 *************************************************/
1853
1854 /* Called from acl_check_condition() below
1855
1856 Arguments:
1857 arg the argument string for control=
1858 pptr set to point to the terminating character
1859 where which ACL we are in
1860 log_msgptr for error messages
1861
1862 Returns: CONTROL_xxx value
1863 */
1864
1865 static int
1866 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
1867 {
1868 int len;
1869 control_def *d;
1870
1871 for (d = controls_list;
1872 d < controls_list + sizeof(controls_list)/sizeof(control_def);
1873 d++)
1874 {
1875 len = Ustrlen(d->name);
1876 if (Ustrncmp(d->name, arg, len) == 0) break;
1877 }
1878
1879 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
1880 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
1881 {
1882 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
1883 return CONTROL_ERROR;
1884 }
1885
1886 *pptr = arg + len;
1887 return d->value;
1888 }
1889
1890
1891
1892 /*************************************************
1893 * Handle rate limiting *
1894 *************************************************/
1895
1896 /* Called by acl_check_condition() below to calculate the result
1897 of the ACL ratelimit condition.
1898
1899 Note that the return value might be slightly unexpected: if the
1900 sender's rate is above the limit then the result is OK. This is
1901 similar to the dnslists condition, and is so that you can write
1902 ACL clauses like: defer ratelimit = 15 / 1h
1903
1904 Arguments:
1905 arg the option string for ratelimit=
1906 log_msgptr for error messages
1907
1908 Returns: OK - Sender's rate is above limit
1909 FAIL - Sender's rate is below limit
1910 DEFER - Problem opening ratelimit database
1911 ERROR - Syntax error in options.
1912 */
1913
1914 static int
1915 acl_ratelimit(uschar *arg, uschar **log_msgptr)
1916 {
1917 double limit, period;
1918 uschar *ss, *key = arg;
1919 int sep = '/';
1920 BOOL have_key = FALSE, leaky = FALSE, strict = FALSE;
1921 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
1922 int old_pool, rc;
1923 tree_node **anchor, *t;
1924 open_db dbblock, *dbm;
1925 dbdata_ratelimit *dbd;
1926 struct timeval tv;
1927
1928 /* Parse the first two options and record their values in expansion
1929 variables. These variables allow the configuration to have informative
1930 error messages based on rate limits obtained from a table lookup. */
1931
1932 /* First is the maximum number of messages per period and maximum burst
1933 size, which must be greater than or equal to zero. Zero is useful for
1934 rate measurement as opposed to rate limiting. */
1935
1936 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
1937 if (sender_rate_limit == NULL)
1938 limit = -1.0;
1939 else
1940 {
1941 limit = Ustrtod(sender_rate_limit, &ss);
1942 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
1943 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
1944 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
1945 }
1946 if (limit < 0.0 || *ss != 0)
1947 {
1948 *log_msgptr = string_sprintf("syntax error in argument for "
1949 "\"ratelimit\" condition: \"%s\" is not a positive number",
1950 sender_rate_limit);
1951 return ERROR;
1952 }
1953
1954 /* Second is the rate measurement period and exponential smoothing time
1955 constant. This must be strictly greater than zero, because zero leads to
1956 run-time division errors. */
1957
1958 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
1959 if (sender_rate_period == NULL) period = -1.0;
1960 else period = readconf_readtime(sender_rate_period, 0, FALSE);
1961 if (period <= 0.0)
1962 {
1963 *log_msgptr = string_sprintf("syntax error in argument for "
1964 "\"ratelimit\" condition: \"%s\" is not a time value",
1965 sender_rate_period);
1966 return ERROR;
1967 }
1968
1969 /* Parse the other options. Should we check if the per_* options are being
1970 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
1971
1972 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
1973 != NULL)
1974 {
1975 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
1976 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
1977 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
1978 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
1979 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
1980 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
1981 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
1982 else have_key = TRUE;
1983 }
1984 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
1985 {
1986 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
1987 return ERROR;
1988 }
1989
1990 /* Default option values */
1991 if (!strict) leaky = TRUE;
1992 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
1993
1994 /* We use the whole of the argument list as the lookup key, because it doesn't
1995 make sense to use the same stored data if any of the arguments are different.
1996 If there is no explicit key, use the sender_host_address. If there is no
1997 sender_host_address (e.g. -bs or acl_not_smtp) then we simply omit it. */
1998
1999 if (!have_key && sender_host_address != NULL)
2000 key = string_sprintf("%s / %s", key, sender_host_address);
2001
2002 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2003 limit, period, key);
2004
2005 /* If we are dealing with rate limits per connection, per message, or per byte,
2006 see if we have already computed the rate by looking in the relevant tree. For
2007 per-connection rate limiting, store tree nodes and dbdata in the permanent pool
2008 so that they survive across resets. */
2009
2010 anchor = NULL;
2011 old_pool = store_pool;
2012
2013 if (per_conn)
2014 {
2015 anchor = &ratelimiters_conn;
2016 store_pool = POOL_PERM;
2017 }
2018 if (per_mail || per_byte)
2019 anchor = &ratelimiters_mail;
2020
2021 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2022 {
2023 dbd = t->data.ptr;
2024 /* The following few lines duplicate some of the code below. */
2025 if (dbd->rate > limit) rc = OK;
2026 else rc = FAIL;
2027 store_pool = old_pool;
2028 sender_rate = string_sprintf("%.1f", dbd->rate);
2029 HDEBUG(D_acl)
2030 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2031 return rc;
2032 }
2033
2034 /* We aren't using a pre-computed rate, so get a previously recorded
2035 rate from the database, update it, and write it back. If there's no
2036 previous rate for this key, create one. */
2037
2038 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2039 if (dbm == NULL)
2040 {
2041 store_pool = old_pool;
2042 sender_rate = NULL;
2043 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2044 *log_msgptr = US"ratelimit database not available";
2045 return DEFER;
2046 }
2047 dbd = dbfn_read(dbm, key);
2048
2049 gettimeofday(&tv, NULL);
2050
2051 if (dbd == NULL)
2052 {
2053 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2054 dbd = store_get(sizeof(dbdata_ratelimit));
2055 dbd->time_stamp = tv.tv_sec;
2056 dbd->time_usec = tv.tv_usec;
2057 dbd->rate = 0.0;
2058 }
2059 else
2060 {
2061 /* The smoothed rate is computed using an exponentially weighted moving
2062 average adjusted for variable sampling intervals. The standard EWMA for
2063 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2064 where f() is the measured value and f'() is the smoothed value.
2065
2066 Old data decays out of the smoothed value exponentially, such that data n
2067 samples old is multiplied by a^n. The exponential decay time constant p
2068 is defined such that data p samples old is multiplied by 1/e, which means
2069 that a = exp(-1/p). We can maintain the same time constant for a variable
2070 sampling interval i by using a = exp(-i/p).
2071
2072 The rate we are measuring is messages per period, suitable for directly
2073 comparing with the limit. The average rate between now and the previous
2074 message is period / interval, which we feed into the EWMA as the sample.
2075
2076 It turns out that the number of messages required for the smoothed rate
2077 to reach the limit when they are sent in a burst is equal to the limit.
2078 This can be seen by analysing the value of the smoothed rate after N
2079 messages sent at even intervals. Let k = (1 - a) * p/i
2080
2081 rate_1 = (1 - a) * p/i + a * rate_0
2082 = k + a * rate_0
2083 rate_2 = k + a * rate_1
2084 = k + a * k + a^2 * rate_0
2085 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2086 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2087 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2088 = rate_0 * a^N + p/i * (1 - a^N)
2089
2090 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2091
2092 rate_N = p/i + (rate_0 - p/i) * a^N
2093 a^N = (rate_N - p/i) / (rate_0 - p/i)
2094 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2095 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2096
2097 Numerical analysis of the above equation, setting the computed rate to
2098 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2099 rates, p/i, the number of messages N = limit. So limit serves as both the
2100 maximum rate measured in messages per period, and the maximum number of
2101 messages that can be sent in a fast burst. */
2102
2103 double this_time = (double)tv.tv_sec
2104 + (double)tv.tv_usec / 1000000.0;
2105 double prev_time = (double)dbd->time_stamp
2106 + (double)dbd->time_usec / 1000000.0;
2107 double interval = this_time - prev_time;
2108
2109 double i_over_p = interval / period;
2110 double a = exp(-i_over_p);
2111
2112 /* We must avoid division by zero, and deal gracefully with the clock going
2113 backwards. If we blunder ahead when time is in reverse then the computed
2114 rate will become bogusly huge. Clamp i/p to a very small number instead. */
2115
2116 if (i_over_p <= 0.0) i_over_p = 1e-9;
2117
2118 dbd->time_stamp = tv.tv_sec;
2119 dbd->time_usec = tv.tv_usec;
2120
2121 /* If we are measuring the rate in bytes per period, multiply the
2122 measured rate by the message size. If we don't know the message size
2123 then it's safe to just use a value of zero and let the recorded rate
2124 decay as if nothing happened. */
2125
2126 if (per_byte)
2127 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2128 * (1 - a) / i_over_p + a * dbd->rate;
2129 else
2130 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2131 }
2132
2133 if (dbd->rate > limit) rc = OK;
2134 else rc = FAIL;
2135
2136 /* Update the state if the rate is low or if we are being strict. If we
2137 are in leaky mode and the sender's rate is too high, we do not update
2138 the recorded rate in order to avoid an over-aggressive sender's retry
2139 rate preventing them from getting any email through. */
2140
2141 if (rc == FAIL || !leaky)
2142 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2143 dbfn_close(dbm);
2144
2145 /* Store the result in the tree for future reference, if necessary. */
2146
2147 if (anchor != NULL)
2148 {
2149 t = store_get(sizeof(tree_node) + Ustrlen(key));
2150 t->data.ptr = dbd;
2151 Ustrcpy(t->name, key);
2152 (void)tree_insertnode(anchor, t);
2153 }
2154
2155 /* We create the formatted version of the sender's rate very late in
2156 order to ensure that it is done using the correct storage pool. */
2157
2158 store_pool = old_pool;
2159 sender_rate = string_sprintf("%.1f", dbd->rate);
2160
2161 HDEBUG(D_acl)
2162 debug_printf("ratelimit computed rate %s\n", sender_rate);
2163
2164 return rc;
2165 }
2166
2167
2168
2169 /*************************************************
2170 * Handle conditions/modifiers on an ACL item *
2171 *************************************************/
2172
2173 /* Called from acl_check() below.
2174
2175 Arguments:
2176 verb ACL verb
2177 cb ACL condition block - if NULL, result is OK
2178 where where called from
2179 addr the address being checked for RCPT, or NULL
2180 level the nesting level
2181 epp pointer to pass back TRUE if "endpass" encountered
2182 (applies only to "accept" and "discard")
2183 user_msgptr user message pointer
2184 log_msgptr log message pointer
2185 basic_errno pointer to where to put verify error
2186
2187 Returns: OK - all conditions are met
2188 DISCARD - an "acl" condition returned DISCARD - only allowed
2189 for "accept" or "discard" verbs
2190 FAIL - at least one condition fails
2191 FAIL_DROP - an "acl" condition returned FAIL_DROP
2192 DEFER - can't tell at the moment (typically, lookup defer,
2193 but can be temporary callout problem)
2194 ERROR - ERROR from nested ACL or expansion failure or other
2195 error
2196 */
2197
2198 static int
2199 acl_check_condition(int verb, acl_condition_block *cb, int where,
2200 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2201 uschar **log_msgptr, int *basic_errno)
2202 {
2203 uschar *user_message = NULL;
2204 uschar *log_message = NULL;
2205 uschar *p;
2206 int rc = OK;
2207 #ifdef WITH_CONTENT_SCAN
2208 int sep = '/';
2209 #endif
2210
2211 for (; cb != NULL; cb = cb->next)
2212 {
2213 uschar *arg;
2214 int control_type;
2215
2216 /* The message and log_message items set up messages to be used in
2217 case of rejection. They are expanded later. */
2218
2219 if (cb->type == ACLC_MESSAGE)
2220 {
2221 user_message = cb->arg;
2222 continue;
2223 }
2224
2225 if (cb->type == ACLC_LOG_MESSAGE)
2226 {
2227 log_message = cb->arg;
2228 continue;
2229 }
2230
2231 /* The endpass "condition" just sets a flag to show it occurred. This is
2232 checked at compile time to be on an "accept" or "discard" item. */
2233
2234 if (cb->type == ACLC_ENDPASS)
2235 {
2236 *epp = TRUE;
2237 continue;
2238 }
2239
2240 /* For other conditions and modifiers, the argument is expanded now for some
2241 of them, but not for all, because expansion happens down in some lower level
2242 checking functions in some cases. */
2243
2244 if (cond_expand_at_top[cb->type])
2245 {
2246 arg = expand_string(cb->arg);
2247 if (arg == NULL)
2248 {
2249 if (expand_string_forcedfail) continue;
2250 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2251 cb->arg, expand_string_message);
2252 return search_find_defer? DEFER : ERROR;
2253 }
2254 }
2255 else arg = cb->arg;
2256
2257 /* Show condition, and expanded condition if it's different */
2258
2259 HDEBUG(D_acl)
2260 {
2261 int lhswidth = 0;
2262 debug_printf("check %s%s %n",
2263 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2264 conditions[cb->type], &lhswidth);
2265
2266 if (cb->type == ACLC_SET)
2267 {
2268 int n = cb->u.varnumber;
2269 int t = (n < ACL_C_MAX)? 'c' : 'm';
2270 if (n >= ACL_C_MAX) n -= ACL_C_MAX;
2271 debug_printf("acl_%c%d ", t, n);
2272 lhswidth += 7;
2273 }
2274
2275 debug_printf("= %s\n", cb->arg);
2276
2277 if (arg != cb->arg)
2278 debug_printf("%.*s= %s\n", lhswidth,
2279 US" ", CS arg);
2280 }
2281
2282 /* Check that this condition makes sense at this time */
2283
2284 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2285 {
2286 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2287 cond_modifiers[cb->type]? "use" : "test",
2288 conditions[cb->type], acl_wherenames[where]);
2289 return ERROR;
2290 }
2291
2292 /* Run the appropriate test for each condition, or take the appropriate
2293 action for the remaining modifiers. */
2294
2295 switch(cb->type)
2296 {
2297 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2298 "discard" verb. */
2299
2300 case ACLC_ACL:
2301 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2302 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2303 {
2304 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2305 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2306 verbs[verb]);
2307 return ERROR;
2308 }
2309 break;
2310
2311 case ACLC_AUTHENTICATED:
2312 rc = (sender_host_authenticated == NULL)? FAIL :
2313 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2314 TRUE, NULL);
2315 break;
2316
2317 #ifdef EXPERIMENTAL_BRIGHTMAIL
2318 case ACLC_BMI_OPTIN:
2319 {
2320 int old_pool = store_pool;
2321 store_pool = POOL_PERM;
2322 bmi_current_optin = string_copy(arg);
2323 store_pool = old_pool;
2324 }
2325 break;
2326 #endif
2327
2328 case ACLC_CONDITION:
2329 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2330 rc = (Uatoi(arg) == 0)? FAIL : OK;
2331 else
2332 rc = (strcmpic(arg, US"no") == 0 ||
2333 strcmpic(arg, US"false") == 0)? FAIL :
2334 (strcmpic(arg, US"yes") == 0 ||
2335 strcmpic(arg, US"true") == 0)? OK : DEFER;
2336 if (rc == DEFER)
2337 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2338 break;
2339
2340 case ACLC_CONTROL:
2341 control_type = decode_control(arg, &p, where, log_msgptr);
2342
2343 /* Check if this control makes sense at this time */
2344
2345 if ((control_forbids[control_type] & (1 << where)) != 0)
2346 {
2347 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2348 controls[control_type], acl_wherenames[where]);
2349 return ERROR;
2350 }
2351
2352 switch(control_type)
2353 {
2354 #ifdef EXPERIMENTAL_BRIGHTMAIL
2355 case CONTROL_BMI_RUN:
2356 bmi_run = 1;
2357 break;
2358 #endif
2359 #ifdef EXPERIMENTAL_DOMAINKEYS
2360 case CONTROL_DK_VERIFY:
2361 dk_do_verify = 1;
2362 break;
2363 #endif
2364 case CONTROL_ERROR:
2365 return ERROR;
2366
2367 case CONTROL_CASEFUL_LOCAL_PART:
2368 deliver_localpart = addr->cc_local_part;
2369 break;
2370
2371 case CONTROL_CASELOWER_LOCAL_PART:
2372 deliver_localpart = addr->lc_local_part;
2373 break;
2374
2375 case CONTROL_ENFORCE_SYNC:
2376 smtp_enforce_sync = TRUE;
2377 break;
2378
2379 case CONTROL_NO_ENFORCE_SYNC:
2380 smtp_enforce_sync = FALSE;
2381 break;
2382
2383 #ifdef WITH_CONTENT_SCAN
2384 case CONTROL_NO_MBOX_UNSPOOL:
2385 no_mbox_unspool = TRUE;
2386 break;
2387 #endif
2388
2389 case CONTROL_NO_MULTILINE:
2390 no_multiline_responses = TRUE;
2391 break;
2392
2393 case CONTROL_FAKEDEFER:
2394 case CONTROL_FAKEREJECT:
2395 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2396 if (*p == '/')
2397 {
2398 uschar *pp = p + 1;
2399 while (*pp != 0) pp++;
2400 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2401 p = pp;
2402 }
2403 else
2404 {
2405 /* Explicitly reset to default string */
2406 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).";
2407 }
2408 break;
2409
2410 case CONTROL_FREEZE:
2411 deliver_freeze = TRUE;
2412 deliver_frozen_at = time(NULL);
2413 break;
2414
2415 case CONTROL_QUEUE_ONLY:
2416 queue_only_policy = TRUE;
2417 break;
2418
2419 case CONTROL_SUBMISSION:
2420 originator_name = US"";
2421 submission_mode = TRUE;
2422 while (*p == '/')
2423 {
2424 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2425 {
2426 p += 14;
2427 active_local_sender_retain = TRUE;
2428 active_local_from_check = FALSE;
2429 }
2430 else if (Ustrncmp(p, "/domain=", 8) == 0)
2431 {
2432 uschar *pp = p + 8;
2433 while (*pp != 0 && *pp != '/') pp++;
2434 submission_domain = string_copyn(p+8, pp-p-8);
2435 p = pp;
2436 }
2437 else if (Ustrncmp(p, "/name=", 6) == 0)
2438 {
2439 uschar *pp = p + 6;
2440 while (*pp != 0 && *pp != '/') pp++;
2441 originator_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2442 big_buffer, big_buffer_size));
2443 p = pp;
2444 }
2445 else break;
2446 }
2447 if (*p != 0)
2448 {
2449 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2450 return ERROR;
2451 }
2452 break;
2453 }
2454 break;
2455
2456 #ifdef WITH_CONTENT_SCAN
2457 case ACLC_DECODE:
2458 rc = mime_decode(&arg);
2459 break;
2460 #endif
2461
2462 case ACLC_DELAY:
2463 {
2464 int delay = readconf_readtime(arg, 0, FALSE);
2465 if (delay < 0)
2466 {
2467 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2468 "modifier: \"%s\" is not a time value", arg);
2469 return ERROR;
2470 }
2471 else
2472 {
2473 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2474 delay);
2475 if (host_checking)
2476 {
2477 HDEBUG(D_acl)
2478 debug_printf("delay skipped in -bh checking mode\n");
2479 }
2480
2481 /* It appears to be impossible to detect that a TCP/IP connection has
2482 gone away without reading from it. This means that we cannot shorten
2483 the delay below if the client goes away, because we cannot discover
2484 that the client has closed its end of the connection. (The connection
2485 is actually in a half-closed state, waiting for the server to close its
2486 end.) It would be nice to be able to detect this state, so that the
2487 Exim process is not held up unnecessarily. However, it seems that we
2488 can't. The poll() function does not do the right thing, and in any case
2489 it is not always available.
2490
2491 NOTE: If ever this state of affairs changes, remember that we may be
2492 dealing with stdin/stdout here, in addition to TCP/IP connections.
2493 Whatever is done must work in both cases. To detected the stdin/stdout
2494 case, check for smtp_in or smtp_out being NULL. */
2495
2496 else
2497 {
2498 while (delay > 0) delay = sleep(delay);
2499 }
2500 }
2501 }
2502 break;
2503
2504 #ifdef WITH_OLD_DEMIME
2505 case ACLC_DEMIME:
2506 rc = demime(&arg);
2507 break;
2508 #endif
2509
2510 #ifdef EXPERIMENTAL_DOMAINKEYS
2511 case ACLC_DK_DOMAIN_SOURCE:
2512 if (dk_verify_block == NULL) { rc = FAIL; break; };
2513 /* check header source of domain against given string */
2514 switch (dk_verify_block->address_source) {
2515 case DK_EXIM_ADDRESS_FROM_FROM:
2516 rc = match_isinlist(US"from", &arg, 0, NULL,
2517 NULL, MCL_STRING, TRUE, NULL);
2518 break;
2519 case DK_EXIM_ADDRESS_FROM_SENDER:
2520 rc = match_isinlist(US"sender", &arg, 0, NULL,
2521 NULL, MCL_STRING, TRUE, NULL);
2522 break;
2523 case DK_EXIM_ADDRESS_NONE:
2524 rc = match_isinlist(US"none", &arg, 0, NULL,
2525 NULL, MCL_STRING, TRUE, NULL);
2526 break;
2527 }
2528 break;
2529 case ACLC_DK_POLICY:
2530 if (dk_verify_block == NULL) { rc = FAIL; break; };
2531 /* check policy against given string, default FAIL */
2532 rc = FAIL;
2533 if (dk_verify_block->signsall)
2534 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2535 NULL, MCL_STRING, TRUE, NULL);
2536 if (dk_verify_block->testing)
2537 rc = match_isinlist(US"testing", &arg, 0, NULL,
2538 NULL, MCL_STRING, TRUE, NULL);
2539 break;
2540 case ACLC_DK_SENDER_DOMAINS:
2541 if (dk_verify_block == NULL) { rc = FAIL; break; };
2542 if (dk_verify_block->domain != NULL)
2543 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2544 NULL, MCL_DOMAIN, TRUE, NULL);
2545 else rc = FAIL;
2546 break;
2547 case ACLC_DK_SENDER_LOCAL_PARTS:
2548 if (dk_verify_block == NULL) { rc = FAIL; break; };
2549 if (dk_verify_block->local_part != NULL)
2550 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2551 NULL, MCL_LOCALPART, TRUE, NULL);
2552 else rc = FAIL;
2553 break;
2554 case ACLC_DK_SENDERS:
2555 if (dk_verify_block == NULL) { rc = FAIL; break; };
2556 if (dk_verify_block->address != NULL)
2557 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2558 else rc = FAIL;
2559 break;
2560 case ACLC_DK_STATUS:
2561 if (dk_verify_block == NULL) { rc = FAIL; break; };
2562 if (dk_verify_block->result > 0) {
2563 switch(dk_verify_block->result) {
2564 case DK_EXIM_RESULT_BAD_FORMAT:
2565 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2566 NULL, MCL_STRING, TRUE, NULL);
2567 break;
2568 case DK_EXIM_RESULT_NO_KEY:
2569 rc = match_isinlist(US"no key", &arg, 0, NULL,
2570 NULL, MCL_STRING, TRUE, NULL);
2571 break;
2572 case DK_EXIM_RESULT_NO_SIGNATURE:
2573 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2574 NULL, MCL_STRING, TRUE, NULL);
2575 break;
2576 case DK_EXIM_RESULT_REVOKED:
2577 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2578 NULL, MCL_STRING, TRUE, NULL);
2579 break;
2580 case DK_EXIM_RESULT_NON_PARTICIPANT:
2581 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2582 NULL, MCL_STRING, TRUE, NULL);
2583 break;
2584 case DK_EXIM_RESULT_GOOD:
2585 rc = match_isinlist(US"good", &arg, 0, NULL,
2586 NULL, MCL_STRING, TRUE, NULL);
2587 break;
2588 case DK_EXIM_RESULT_BAD:
2589 rc = match_isinlist(US"bad", &arg, 0, NULL,
2590 NULL, MCL_STRING, TRUE, NULL);
2591 break;
2592 }
2593 }
2594 break;
2595 #endif
2596
2597 case ACLC_DNSLISTS:
2598 rc = verify_check_dnsbl(&arg);
2599 break;
2600
2601 case ACLC_DOMAINS:
2602 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2603 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2604 break;
2605
2606 /* The value in tls_cipher is the full cipher name, for example,
2607 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2608 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2609 what may in practice come out of the SSL library - which at the time of
2610 writing is poorly documented. */
2611
2612 case ACLC_ENCRYPTED:
2613 if (tls_cipher == NULL) rc = FAIL; else
2614 {
2615 uschar *endcipher = NULL;
2616 uschar *cipher = Ustrchr(tls_cipher, ':');
2617 if (cipher == NULL) cipher = tls_cipher; else
2618 {
2619 endcipher = Ustrchr(++cipher, ':');
2620 if (endcipher != NULL) *endcipher = 0;
2621 }
2622 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2623 if (endcipher != NULL) *endcipher = ':';
2624 }
2625 break;
2626
2627 /* Use verify_check_this_host() instead of verify_check_host() so that
2628 we can pass over &host_data to catch any looked up data. Once it has been
2629 set, it retains its value so that it's still there if another ACL verb
2630 comes through here and uses the cache. However, we must put it into
2631 permanent store in case it is also expected to be used in a subsequent
2632 message in the same SMTP connection. */
2633
2634 case ACLC_HOSTS:
2635 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2636 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2637 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2638 break;
2639
2640 case ACLC_LOCAL_PARTS:
2641 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2642 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2643 &deliver_localpart_data);
2644 break;
2645
2646 case ACLC_LOGWRITE:
2647 {
2648 int logbits = 0;
2649 uschar *s = arg;
2650 if (*s == ':')
2651 {
2652 s++;
2653 while (*s != ':')
2654 {
2655 if (Ustrncmp(s, "main", 4) == 0)
2656 { logbits |= LOG_MAIN; s += 4; }
2657 else if (Ustrncmp(s, "panic", 5) == 0)
2658 { logbits |= LOG_PANIC; s += 5; }
2659 else if (Ustrncmp(s, "reject", 6) == 0)
2660 { logbits |= LOG_REJECT; s += 6; }
2661 else
2662 {
2663 logbits = LOG_MAIN|LOG_PANIC;
2664 s = string_sprintf(":unknown log name in \"%s\" in "
2665 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2666 }
2667 if (*s == ',') s++;
2668 }
2669 s++;
2670 }
2671 while (isspace(*s)) s++;
2672 if (logbits == 0) logbits = LOG_MAIN;
2673 log_write(0, logbits, "%s", string_printing(s));
2674 }
2675 break;
2676
2677 #ifdef WITH_CONTENT_SCAN
2678 case ACLC_MALWARE:
2679 {
2680 /* Seperate the regular expression and any optional parameters. */
2681 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2682 /* Run the malware backend. */
2683 rc = malware(&ss);
2684 /* Modify return code based upon the existance of options. */
2685 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2686 != NULL) {
2687 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2688 {
2689 /* FAIL so that the message is passed to the next ACL */
2690 rc = FAIL;
2691 }
2692 }
2693 }
2694 break;
2695
2696 case ACLC_MIME_REGEX:
2697 rc = mime_regex(&arg);
2698 break;
2699 #endif
2700
2701 case ACLC_RATELIMIT:
2702 rc = acl_ratelimit(arg, log_msgptr);
2703 break;
2704
2705 case ACLC_RECIPIENTS:
2706 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
2707 &recipient_data);
2708 break;
2709
2710 #ifdef WITH_CONTENT_SCAN
2711 case ACLC_REGEX:
2712 rc = regex(&arg);
2713 break;
2714 #endif
2715
2716 case ACLC_SENDER_DOMAINS:
2717 {
2718 uschar *sdomain;
2719 sdomain = Ustrrchr(sender_address, '@');
2720 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
2721 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
2722 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
2723 }
2724 break;
2725
2726 case ACLC_SENDERS:
2727 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
2728 sender_address_cache, -1, 0, &sender_data);
2729 break;
2730
2731 /* Connection variables must persist forever */
2732
2733 case ACLC_SET:
2734 {
2735 int old_pool = store_pool;
2736 if (cb->u.varnumber < ACL_C_MAX) store_pool = POOL_PERM;
2737 acl_var[cb->u.varnumber] = string_copy(arg);
2738 store_pool = old_pool;
2739 }
2740 break;
2741
2742 #ifdef WITH_CONTENT_SCAN
2743 case ACLC_SPAM:
2744 {
2745 /* Seperate the regular expression and any optional parameters. */
2746 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2747 /* Run the spam backend. */
2748 rc = spam(&ss);
2749 /* Modify return code based upon the existance of options. */
2750 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2751 != NULL) {
2752 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2753 {
2754 /* FAIL so that the message is passed to the next ACL */
2755 rc = FAIL;
2756 }
2757 }
2758 }
2759 break;
2760 #endif
2761
2762 #ifdef EXPERIMENTAL_SPF
2763 case ACLC_SPF:
2764 rc = spf_process(&arg, sender_address);
2765 break;
2766 #endif
2767
2768 /* If the verb is WARN, discard any user message from verification, because
2769 such messages are SMTP responses, not header additions. The latter come
2770 only from explicit "message" modifiers. However, put the user message into
2771 $acl_verify_message so it can be used in subsequent conditions or modifiers
2772 (until something changes it). */
2773
2774 case ACLC_VERIFY:
2775 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
2776 acl_verify_message = *user_msgptr;
2777 if (verb == ACL_WARN) *user_msgptr = NULL;
2778 break;
2779
2780 default:
2781 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
2782 "condition %d", cb->type);
2783 break;
2784 }
2785
2786 /* If a condition was negated, invert OK/FAIL. */
2787
2788 if (!cond_modifiers[cb->type] && cb->u.negated)
2789 {
2790 if (rc == OK) rc = FAIL;
2791 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
2792 }
2793
2794 if (rc != OK) break; /* Conditions loop */
2795 }
2796
2797
2798 /* If the result is the one for which "message" and/or "log_message" are used,
2799 handle the values of these options. Most verbs have but a single return for
2800 which the messages are relevant, but for "discard", it's useful to have the log
2801 message both when it succeeds and when it fails. Also, for an "accept" that
2802 appears in a QUIT ACL, we want to handle the user message. Since only "accept"
2803 and "warn" are permitted in that ACL, we don't need to test the verb.
2804
2805 These modifiers act in different ways:
2806
2807 "message" is a user message that will be included in an SMTP response. Unless
2808 it is empty, it overrides any previously set user message.
2809
2810 "log_message" is a non-user message, and it adds to any existing non-user
2811 message that is already set.
2812
2813 If there isn't a log message set, we make it the same as the user message. */
2814
2815 if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] ||
2816 (verb == ACL_DISCARD && rc == OK) ||
2817 (where == ACL_WHERE_QUIT))
2818 {
2819 uschar *expmessage;
2820
2821 /* If the verb is "warn", messages generated by conditions (verification or
2822 nested ACLs) are discarded. Only messages specified at this level are used.
2823 However, the value of an existing message is available in $acl_verify_message
2824 during expansions. */
2825
2826 uschar *old_user_msgptr = *user_msgptr;
2827 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
2828
2829 if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL;
2830
2831 if (user_message != NULL)
2832 {
2833 acl_verify_message = old_user_msgptr;
2834 expmessage = expand_string(user_message);
2835 if (expmessage == NULL)
2836 {
2837 if (!expand_string_forcedfail)
2838 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2839 user_message, expand_string_message);
2840 }
2841 else if (expmessage[0] != 0) *user_msgptr = expmessage;
2842 }
2843
2844 if (log_message != NULL)
2845 {
2846 acl_verify_message = old_log_msgptr;
2847 expmessage = expand_string(log_message);
2848 if (expmessage == NULL)
2849 {
2850 if (!expand_string_forcedfail)
2851 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2852 log_message, expand_string_message);
2853 }
2854 else if (expmessage[0] != 0)
2855 {
2856 *log_msgptr = (*log_msgptr == NULL)? expmessage :
2857 string_sprintf("%s: %s", expmessage, *log_msgptr);
2858 }
2859 }
2860
2861 /* If no log message, default it to the user message */
2862
2863 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
2864 }
2865
2866 acl_verify_message = NULL;
2867 return rc;
2868 }
2869
2870
2871
2872
2873
2874 /*************************************************
2875 * Get line from a literal ACL *
2876 *************************************************/
2877
2878 /* This function is passed to acl_read() in order to extract individual lines
2879 of a literal ACL, which we access via static pointers. We can destroy the
2880 contents because this is called only once (the compiled ACL is remembered).
2881
2882 This code is intended to treat the data in the same way as lines in the main
2883 Exim configuration file. That is:
2884
2885 . Leading spaces are ignored.
2886
2887 . A \ at the end of a line is a continuation - trailing spaces after the \
2888 are permitted (this is because I don't believe in making invisible things
2889 significant). Leading spaces on the continued part of a line are ignored.
2890
2891 . Physical lines starting (significantly) with # are totally ignored, and
2892 may appear within a sequence of backslash-continued lines.
2893
2894 . Blank lines are ignored, but will end a sequence of continuations.
2895
2896 Arguments: none
2897 Returns: a pointer to the next line
2898 */
2899
2900
2901 static uschar *acl_text; /* Current pointer in the text */
2902 static uschar *acl_text_end; /* Points one past the terminating '0' */
2903
2904
2905 static uschar *
2906 acl_getline(void)
2907 {
2908 uschar *yield;
2909
2910 /* This loop handles leading blank lines and comments. */
2911
2912 for(;;)
2913 {
2914 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
2915 if (*acl_text == 0) return NULL; /* No more data */
2916 yield = acl_text; /* Potential data line */
2917
2918 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2919
2920 /* If we hit the end before a newline, we have the whole logical line. If
2921 it's a comment, there's no more data to be given. Otherwise, yield it. */
2922
2923 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
2924
2925 /* After reaching a newline, end this loop if the physical line does not
2926 start with '#'. If it does, it's a comment, and the loop continues. */
2927
2928 if (*yield != '#') break;
2929 }
2930
2931 /* This loop handles continuations. We know we have some real data, ending in
2932 newline. See if there is a continuation marker at the end (ignoring trailing
2933 white space). We know that *yield is not white space, so no need to test for
2934 cont > yield in the backwards scanning loop. */
2935
2936 for(;;)
2937 {
2938 uschar *cont;
2939 for (cont = acl_text - 1; isspace(*cont); cont--);
2940
2941 /* If no continuation follows, we are done. Mark the end of the line and
2942 return it. */
2943
2944 if (*cont != '\\')
2945 {
2946 *acl_text++ = 0;
2947 return yield;
2948 }
2949
2950 /* We have encountered a continuation. Skip over whitespace at the start of
2951 the next line, and indeed the whole of the next line or lines if they are
2952 comment lines. */
2953
2954 for (;;)
2955 {
2956 while (*(++acl_text) == ' ' || *acl_text == '\t');
2957 if (*acl_text != '#') break;
2958 while (*(++acl_text) != 0 && *acl_text != '\n');
2959 }
2960
2961 /* We have the start of a continuation line. Move all the rest of the data
2962 to join onto the previous line, and then find its end. If the end is not a
2963 newline, we are done. Otherwise loop to look for another continuation. */
2964
2965 memmove(cont, acl_text, acl_text_end - acl_text);
2966 acl_text_end -= acl_text - cont;
2967 acl_text = cont;
2968 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2969 if (*acl_text == 0) return yield;
2970 }
2971
2972 /* Control does not reach here */
2973 }
2974
2975
2976
2977
2978
2979 /*************************************************
2980 * Check access using an ACL *
2981 *************************************************/
2982
2983 /* This function is called from address_check. It may recurse via
2984 acl_check_condition() - hence the use of a level to stop looping. The ACL is
2985 passed as a string which is expanded. A forced failure implies no access check
2986 is required. If the result is a single word, it is taken as the name of an ACL
2987 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
2988 text, complete with newlines, and parsed as such. In both cases, the ACL check
2989 is then run. This function uses an auxiliary function for acl_read() to call
2990 for reading individual lines of a literal ACL. This is acl_getline(), which
2991 appears immediately above.
2992
2993 Arguments:
2994 where where called from
2995 addr address item when called from RCPT; otherwise NULL
2996 s the input string; NULL is the same as an empty ACL => DENY
2997 level the nesting level
2998 user_msgptr where to put a user error (for SMTP response)
2999 log_msgptr where to put a logging message (not for SMTP response)
3000
3001 Returns: OK access is granted
3002 DISCARD access is apparently granted...
3003 FAIL access is denied
3004 FAIL_DROP access is denied; drop the connection
3005 DEFER can't tell at the moment
3006 ERROR disaster
3007 */
3008
3009 static int
3010 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3011 uschar **user_msgptr, uschar **log_msgptr)
3012 {
3013 int fd = -1;
3014 acl_block *acl = NULL;
3015 uschar *acl_name = US"inline ACL";
3016 uschar *ss;
3017
3018 /* Catch configuration loops */
3019
3020 if (level > 20)
3021 {
3022 *log_msgptr = US"ACL nested too deep: possible loop";
3023 return ERROR;
3024 }
3025
3026 if (s == NULL)
3027 {
3028 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3029 return FAIL;
3030 }
3031
3032 /* At top level, we expand the incoming string. At lower levels, it has already
3033 been expanded as part of condition processing. */
3034
3035 if (level == 0)
3036 {
3037 ss = expand_string(s);
3038 if (ss == NULL)
3039 {
3040 if (expand_string_forcedfail) return OK;
3041 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3042 expand_string_message);
3043 return ERROR;
3044 }
3045 }
3046 else ss = s;
3047
3048 while (isspace(*ss))ss++;
3049
3050 /* If we can't find a named ACL, the default is to parse it as an inline one.
3051 (Unless it begins with a slash; non-existent files give rise to an error.) */
3052
3053 acl_text = ss;
3054
3055 /* Handle the case of a string that does not contain any spaces. Look for a
3056 named ACL among those read from the configuration, or a previously read file.
3057 It is possible that the pointer to the ACL is NULL if the configuration
3058 contains a name with no data. If not found, and the text begins with '/',
3059 read an ACL from a file, and save it so it can be re-used. */
3060
3061 if (Ustrchr(ss, ' ') == NULL)
3062 {
3063 tree_node *t = tree_search(acl_anchor, ss);
3064 if (t != NULL)
3065 {
3066 acl = (acl_block *)(t->data.ptr);
3067 if (acl == NULL)
3068 {
3069 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3070 return FAIL;
3071 }
3072 acl_name = string_sprintf("ACL \"%s\"", ss);
3073 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3074 }
3075
3076 else if (*ss == '/')
3077 {
3078 struct stat statbuf;
3079 fd = Uopen(ss, O_RDONLY, 0);
3080 if (fd < 0)
3081 {
3082 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3083 strerror(errno));
3084 return ERROR;
3085 }
3086
3087 if (fstat(fd, &statbuf) != 0)
3088 {
3089 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3090 strerror(errno));
3091 return ERROR;
3092 }
3093
3094 acl_text = store_get(statbuf.st_size + 1);
3095 acl_text_end = acl_text + statbuf.st_size + 1;
3096
3097 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3098 {
3099 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3100 ss, strerror(errno));
3101 return ERROR;
3102 }
3103 acl_text[statbuf.st_size] = 0;
3104 close(fd);
3105
3106 acl_name = string_sprintf("ACL \"%s\"", ss);
3107 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3108 }
3109 }
3110
3111 /* Parse an ACL that is still in text form. If it came from a file, remember it
3112 in the ACL tree, having read it into the POOL_PERM store pool so that it
3113 persists between multiple messages. */
3114
3115 if (acl == NULL)
3116 {
3117 int old_pool = store_pool;
3118 if (fd >= 0) store_pool = POOL_PERM;
3119 acl = acl_read(acl_getline, log_msgptr);
3120 store_pool = old_pool;
3121 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3122 if (fd >= 0)
3123 {
3124 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3125 Ustrcpy(t->name, ss);
3126 t->data.ptr = acl;
3127 (void)tree_insertnode(&acl_anchor, t);
3128 }
3129 }
3130
3131 /* Now we have an ACL to use. It's possible it may be NULL. */
3132
3133 while (acl != NULL)
3134 {
3135 int cond;
3136 int basic_errno = 0;
3137 BOOL endpass_seen = FALSE;
3138
3139 *log_msgptr = *user_msgptr = NULL;
3140 acl_temp_details = FALSE;
3141
3142 if (where == ACL_WHERE_QUIT &&
3143 acl->verb != ACL_ACCEPT &&
3144 acl->verb != ACL_WARN)
3145 {
3146 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3147 verbs[acl->verb]);
3148 return ERROR;
3149 }
3150
3151 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3152
3153 /* Clear out any search error message from a previous check before testing
3154 this condition. */
3155
3156 search_error_message = NULL;
3157 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3158 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3159
3160 /* Handle special returns: DEFER causes a return except on a WARN verb;
3161 ERROR always causes a return. */
3162
3163 switch (cond)
3164 {
3165 case DEFER:
3166 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3167 if (basic_errno != ERRNO_CALLOUTDEFER)
3168 {
3169 if (search_error_message != NULL && *search_error_message != 0)
3170 *log_msgptr = search_error_message;
3171 if (smtp_return_error_details) acl_temp_details = TRUE;
3172 }
3173 else
3174 {
3175 acl_temp_details = TRUE;
3176 }
3177 if (acl->verb != ACL_WARN) return DEFER;
3178 break;
3179
3180 default: /* Paranoia */
3181 case ERROR:
3182 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3183 return ERROR;
3184
3185 case OK:
3186 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3187 verbs[acl->verb]);
3188 break;
3189
3190 case FAIL:
3191 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3192 break;
3193
3194 /* DISCARD and DROP can happen only from a nested ACL condition, and
3195 DISCARD can happen only for an "accept" or "discard" verb. */
3196
3197 case DISCARD:
3198 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3199 verbs[acl->verb]);
3200 break;
3201
3202 case FAIL_DROP:
3203 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3204 verbs[acl->verb]);
3205 break;
3206 }
3207
3208 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3209 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3210 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3211
3212 switch(acl->verb)
3213 {
3214 case ACL_ACCEPT:
3215 if (cond == OK || cond == DISCARD) return cond;
3216 if (endpass_seen)
3217 {
3218 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3219 return cond;
3220 }
3221 break;
3222
3223 case ACL_DEFER:
3224 if (cond == OK)
3225 {
3226 acl_temp_details = TRUE;
3227 return DEFER;
3228 }
3229 break;
3230
3231 case ACL_DENY:
3232 if (cond == OK) return FAIL;
3233 break;
3234
3235 case ACL_DISCARD:
3236 if (cond == OK || cond == DISCARD) return DISCARD;
3237 if (endpass_seen)
3238 {
3239 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3240 return cond;
3241 }
3242 break;
3243
3244 case ACL_DROP:
3245 if (cond == OK) return FAIL_DROP;
3246 break;
3247
3248 case ACL_REQUIRE:
3249 if (cond != OK) return cond;
3250 break;
3251
3252 case ACL_WARN:
3253 if (cond == OK)
3254 acl_warn(where, *user_msgptr, *log_msgptr);
3255 else if (cond == DEFER)
3256 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3257 "condition test deferred%s%s", host_and_ident(TRUE),
3258 (*log_msgptr == NULL)? US"" : US": ",
3259 (*log_msgptr == NULL)? US"" : *log_msgptr);
3260 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3261 break;
3262
3263 default:
3264 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3265 acl->verb);
3266 break;
3267 }
3268
3269 /* Pass to the next ACL item */
3270
3271 acl = acl->next;
3272 }
3273
3274 /* We have reached the end of the ACL. This is an implicit DENY. */
3275
3276 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3277 return FAIL;
3278 }
3279
3280
3281 /*************************************************
3282 * Check access using an ACL *
3283 *************************************************/
3284
3285 /* This is the external interface for ACL checks. It sets up an address and the
3286 expansions for $domain and $local_part when called after RCPT, then calls
3287 acl_check_internal() to do the actual work.
3288
3289 Arguments:
3290 where ACL_WHERE_xxxx indicating where called from
3291 data_string RCPT address, or SMTP command argument, or NULL
3292 s the input string; NULL is the same as an empty ACL => DENY
3293 user_msgptr where to put a user error (for SMTP response)
3294 log_msgptr where to put a logging message (not for SMTP response)
3295
3296 Returns: OK access is granted by an ACCEPT verb
3297 DISCARD access is granted by a DISCARD verb
3298 FAIL access is denied
3299 FAIL_DROP access is denied; drop the connection
3300 DEFER can't tell at the moment
3301 ERROR disaster
3302 */
3303
3304 int
3305 acl_check(int where, uschar *data_string, uschar *s, uschar **user_msgptr,
3306 uschar **log_msgptr)
3307 {
3308 int rc;
3309 address_item adb;
3310 address_item *addr;
3311
3312 *user_msgptr = *log_msgptr = NULL;
3313 sender_verified_failed = NULL;
3314
3315 if (where == ACL_WHERE_RCPT)
3316 {
3317 adb = address_defaults;
3318 addr = &adb;
3319 addr->address = data_string;
3320 if (deliver_split_address(addr) == DEFER)
3321 {
3322 *log_msgptr = US"defer in percent_hack_domains check";
3323 return DEFER;
3324 }
3325 deliver_domain = addr->domain;
3326 deliver_localpart = addr->local_part;
3327 }
3328 else
3329 {
3330 addr = NULL;
3331 smtp_command_argument = data_string;
3332 }
3333
3334 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3335
3336 smtp_command_argument = deliver_domain =
3337 deliver_localpart = deliver_address_data = sender_address_data = NULL;
3338
3339 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3340 ACL, which is really in the middle of an SMTP command. */
3341
3342 if (rc == DISCARD)
3343 {
3344 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3345 {
3346 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3347 "ACL", acl_wherenames[where]);
3348 return ERROR;
3349 }
3350 return DISCARD;
3351 }
3352
3353 /* A DROP response is not permitted from MAILAUTH */
3354
3355 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3356 {
3357 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3358 "ACL", acl_wherenames[where]);
3359 return ERROR;
3360 }
3361
3362 /* Before giving an error response, take a look at the length of any user
3363 message, and split it up into multiple lines if possible. */
3364
3365 if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75)
3366 {
3367 uschar *s = *user_msgptr = string_copy(*user_msgptr);
3368 uschar *ss = s;
3369
3370 for (;;)
3371 {
3372 int i = 0;
3373 while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++;
3374 if (*ss == 0) break;
3375 if (*ss == '\n')
3376 s = ++ss;
3377 else
3378 {
3379 uschar *t = ss + 1;
3380 uschar *tt = NULL;
3381 while (--t > s + 35)
3382 {
3383 if (*t == ' ')
3384 {
3385 if (t[-1] == ':') { tt = t; break; }
3386 if (tt == NULL) tt = t;
3387 }
3388 }
3389
3390 if (tt == NULL) /* Can't split behind - try ahead */
3391 {
3392 t = ss + 1;
3393 while (*t != 0)
3394 {
3395 if (*t == ' ' || *t == '\n')
3396 { tt = t; break; }
3397 t++;
3398 }
3399 }
3400
3401 if (tt == NULL) break; /* Can't find anywhere to split */
3402 *tt = '\n';
3403 s = ss = tt+1;
3404 }
3405 }
3406 }
3407
3408 return rc;
3409 }
3410
3411 /* End of acl.c */