A minor code clean-up and a comment fix for the CSA patch arising
[exim.git] / src / src / acl.c
1 /* $Cambridge: exim/src/src/acl.c,v 1.38 2005/06/10 18:59:34 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 found = domain;
1147 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1148 {
1149 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1150
1151 default:
1152 return t->data.val = CSA_DEFER_SRV;
1153
1154 /* If we found nothing, the client's authorization is unknown. */
1155
1156 case DNS_NOMATCH:
1157 case DNS_NODATA:
1158 return t->data.val = CSA_UNKNOWN;
1159
1160 /* We got something! Go on to look at the reply in more detail. */
1161
1162 case DNS_SUCCEED:
1163 break;
1164 }
1165
1166 /* Scan the reply for well-formed CSA SRV records. */
1167
1168 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1169 rr != NULL;
1170 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1171 {
1172 if (rr->type != T_SRV) continue;
1173
1174 /* Extract the numerical SRV fields (p is incremented) */
1175
1176 p = rr->data;
1177 GETSHORT(priority, p);
1178 GETSHORT(weight, p);
1179 GETSHORT(port, p);
1180
1181 DEBUG(D_acl)
1182 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1183
1184 /* Check the CSA version number */
1185
1186 if (priority != 1) continue;
1187
1188 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1189 found by dns_special_lookup() is a parent of the one we asked for), we check
1190 the subdomain assertions in the port field. At the moment there's only one
1191 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1192 SRV records of their own. */
1193
1194 if (found != domain)
1195 {
1196 if (port & 1)
1197 return t->data.val = CSA_FAIL_EXPLICIT;
1198 else
1199 return t->data.val = CSA_UNKNOWN;
1200 }
1201
1202 /* This CSA SRV record refers directly to our domain, so we check the value
1203 in the weight field to work out the domain's authorization. 0 and 1 are
1204 unauthorized; 3 means the client is authorized but we can't check the IP
1205 address in order to authenticate it, so we treat it as unknown; values
1206 greater than 3 are undefined. */
1207
1208 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1209
1210 if (weight > 2) continue;
1211
1212 /* Weight == 2, which means the domain is authorized. We must check that the
1213 client's IP address is listed as one of the SRV target addresses. Save the
1214 target hostname then break to scan the additional data for its addresses. */
1215
1216 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1217 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1218
1219 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1220
1221 break;
1222 }
1223
1224 /* If we didn't break the loop then no appropriate records were found. */
1225
1226 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1227
1228 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1229 A target of "." indicates there are no valid addresses, so the client cannot
1230 be authorized. (This is an odd configuration because weight=2 target=. is
1231 equivalent to weight=1, but we check for it in order to keep load off the
1232 root name servers.) Note that dn_expand() turns "." into "". */
1233
1234 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1235
1236 /* Scan the additional section of the CSA SRV reply for addresses belonging
1237 to the target. If the name server didn't return any additional data (e.g.
1238 because it does not fully support SRV records), we need to do another lookup
1239 to obtain the target addresses; otherwise we have a definitive result. */
1240
1241 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1242 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1243
1244 /* The DNS lookup type corresponds to the IP version used by the client. */
1245
1246 #if HAVE_IPV6
1247 if (Ustrchr(sender_host_address, ':') != NULL)
1248 type = T_AAAA;
1249 else
1250 #endif /* HAVE_IPV6 */
1251 type = T_A;
1252
1253
1254 #if HAVE_IPV6 && defined(SUPPORT_A6)
1255 DNS_LOOKUP_AGAIN:
1256 #endif
1257
1258 switch (dns_lookup(&dnsa, target, type, NULL))
1259 {
1260 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1261
1262 default:
1263 return t->data.val = CSA_DEFER_ADDR;
1264
1265 /* If the query succeeded, scan the addresses and return the result. */
1266
1267 case DNS_SUCCEED:
1268 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1269 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1270 /* else fall through */
1271
1272 /* If the target has no IP addresses, the client cannot have an authorized
1273 IP address. However, if the target site uses A6 records (not AAAA records)
1274 we have to do yet another lookup in order to check them. */
1275
1276 case DNS_NOMATCH:
1277 case DNS_NODATA:
1278
1279 #if HAVE_IPV6 && defined(SUPPORT_A6)
1280 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1281 #endif
1282
1283 return t->data.val = CSA_FAIL_NOADDR;
1284 }
1285 }
1286
1287
1288
1289 /*************************************************
1290 * Handle verification (address & other) *
1291 *************************************************/
1292
1293 /* This function implements the "verify" condition. It is called when
1294 encountered in any ACL, because some tests are almost always permitted. Some
1295 just don't make sense, and always fail (for example, an attempt to test a host
1296 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1297
1298 Arguments:
1299 where where called from
1300 addr the recipient address that the ACL is handling, or NULL
1301 arg the argument of "verify"
1302 user_msgptr pointer for user message
1303 log_msgptr pointer for log message
1304 basic_errno where to put verify errno
1305
1306 Returns: OK verification condition succeeded
1307 FAIL verification failed
1308 DEFER there was a problem verifying
1309 ERROR syntax error
1310 */
1311
1312 static int
1313 acl_verify(int where, address_item *addr, uschar *arg,
1314 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1315 {
1316 int sep = '/';
1317 int callout = -1;
1318 int callout_overall = -1;
1319 int callout_connect = -1;
1320 int verify_options = 0;
1321 int rc;
1322 BOOL verify_header_sender = FALSE;
1323 BOOL defer_ok = FALSE;
1324 BOOL callout_defer_ok = FALSE;
1325 BOOL no_details = FALSE;
1326 address_item *sender_vaddr = NULL;
1327 uschar *verify_sender_address = NULL;
1328 uschar *pm_mailfrom = NULL;
1329 uschar *se_mailfrom = NULL;
1330
1331 /* Some of the verify items have slash-separated options; some do not. Diagnose
1332 an error if options are given for items that don't expect them. This code has
1333 now got very message. Refactoring to use a table would be a good idea one day.
1334 */
1335
1336 uschar *slash = Ustrchr(arg, '/');
1337 uschar *list = arg;
1338 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1339
1340 if (ss == NULL) goto BAD_VERIFY;
1341
1342 /* Handle name/address consistency verification in a separate function. */
1343
1344 if (strcmpic(ss, US"reverse_host_lookup") == 0)
1345 {
1346 if (slash != NULL) goto NO_OPTIONS;
1347 if (sender_host_address == NULL) return OK;
1348 return acl_verify_reverse(user_msgptr, log_msgptr);
1349 }
1350
1351 /* TLS certificate verification is done at STARTTLS time; here we just
1352 test whether it was successful or not. (This is for optional verification; for
1353 mandatory verification, the connection doesn't last this long.) */
1354
1355 if (strcmpic(ss, US"certificate") == 0)
1356 {
1357 if (slash != NULL) goto NO_OPTIONS;
1358 if (tls_certificate_verified) return OK;
1359 *user_msgptr = US"no verified certificate";
1360 return FAIL;
1361 }
1362
1363 /* We can test the result of optional HELO verification */
1364
1365 if (strcmpic(ss, US"helo") == 0)
1366 {
1367 if (slash != NULL) goto NO_OPTIONS;
1368 return helo_verified? OK : FAIL;
1369 }
1370
1371 /* Do Client SMTP Authorization checks in a separate function, and turn the
1372 result code into user-friendly strings. */
1373
1374 if (strcmpic(ss, US"csa") == 0)
1375 {
1376 rc = acl_verify_csa(list);
1377 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1378 csa_reason_string[rc]);
1379 csa_status = csa_status_string[rc];
1380 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1381 return csa_return_code[rc];
1382 }
1383
1384 /* Check that all relevant header lines have the correct syntax. If there is
1385 a syntax error, we return details of the error to the sender if configured to
1386 send out full details. (But a "message" setting on the ACL can override, as
1387 always). */
1388
1389 if (strcmpic(ss, US"header_syntax") == 0)
1390 {
1391 if (slash != NULL) goto NO_OPTIONS;
1392 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP)
1393 {
1394 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1395 "(only possible in ACL for DATA)", acl_wherenames[where]);
1396 return ERROR;
1397 }
1398 rc = verify_check_headers(log_msgptr);
1399 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1400 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1401 return rc;
1402 }
1403
1404
1405 /* The remaining verification tests check recipient and sender addresses,
1406 either from the envelope or from the header. There are a number of
1407 slash-separated options that are common to all of them. */
1408
1409
1410 /* Check that there is at least one verifiable sender address in the relevant
1411 header lines. This can be followed by callout and defer options, just like
1412 sender and recipient. */
1413
1414 if (strcmpic(ss, US"header_sender") == 0)
1415 {
1416 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP)
1417 {
1418 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1419 "(only possible in ACL for DATA)", acl_wherenames[where]);
1420 return ERROR;
1421 }
1422 verify_header_sender = TRUE;
1423 }
1424
1425 /* Otherwise, first item in verify argument must be "sender" or "recipient".
1426 In the case of a sender, this can optionally be followed by an address to use
1427 in place of the actual sender (rare special-case requirement). */
1428
1429 else if (strncmpic(ss, US"sender", 6) == 0)
1430 {
1431 uschar *s = ss + 6;
1432 if (where > ACL_WHERE_NOTSMTP)
1433 {
1434 *log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
1435 "(only possible for MAIL, RCPT, PREDATA, or DATA)",
1436 acl_wherenames[where]);
1437 return ERROR;
1438 }
1439 if (*s == 0)
1440 verify_sender_address = sender_address;
1441 else
1442 {
1443 while (isspace(*s)) s++;
1444 if (*s++ != '=') goto BAD_VERIFY;
1445 while (isspace(*s)) s++;
1446 verify_sender_address = string_copy(s);
1447 }
1448 }
1449 else
1450 {
1451 if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
1452 if (addr == NULL)
1453 {
1454 *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
1455 "(only possible for RCPT)", acl_wherenames[where]);
1456 return ERROR;
1457 }
1458 }
1459
1460 /* Remaining items are optional; they apply to sender and recipient
1461 verification, including "header sender" verification. */
1462
1463 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1464 != NULL)
1465 {
1466 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1467 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1468
1469 /* These two old options are left for backwards compatibility */
1470
1471 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1472 {
1473 callout_defer_ok = TRUE;
1474 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1475 }
1476
1477 else if (strcmpic(ss, US"check_postmaster") == 0)
1478 {
1479 pm_mailfrom = US"";
1480 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1481 }
1482
1483 /* The callout option has a number of sub-options, comma separated */
1484
1485 else if (strncmpic(ss, US"callout", 7) == 0)
1486 {
1487 callout = CALLOUT_TIMEOUT_DEFAULT;
1488 ss += 7;
1489 if (*ss != 0)
1490 {
1491 while (isspace(*ss)) ss++;
1492 if (*ss++ == '=')
1493 {
1494 int optsep = ',';
1495 uschar *opt;
1496 uschar buffer[256];
1497 while (isspace(*ss)) ss++;
1498
1499 /* This callout option handling code has become a mess as new options
1500 have been added in an ad hoc manner. It should be tidied up into some
1501 kind of table-driven thing. */
1502
1503 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1504 != NULL)
1505 {
1506 if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
1507 else if (strcmpic(opt, US"no_cache") == 0)
1508 verify_options |= vopt_callout_no_cache;
1509 else if (strcmpic(opt, US"random") == 0)
1510 verify_options |= vopt_callout_random;
1511 else if (strcmpic(opt, US"use_sender") == 0)
1512 verify_options |= vopt_callout_recipsender;
1513 else if (strcmpic(opt, US"use_postmaster") == 0)
1514 verify_options |= vopt_callout_recippmaster;
1515 else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
1516 else if (strcmpic(opt, US"fullpostmaster") == 0)
1517 {
1518 pm_mailfrom = US"";
1519 verify_options |= vopt_callout_fullpm;
1520 }
1521
1522 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1523 {
1524 if (!verify_header_sender)
1525 {
1526 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1527 "callout option only for verify=header_sender (detected in ACL "
1528 "condition \"%s\")", arg);
1529 return ERROR;
1530 }
1531 opt += 8;
1532 while (isspace(*opt)) opt++;
1533 if (*opt++ != '=')
1534 {
1535 *log_msgptr = string_sprintf("'=' expected after "
1536 "\"mailfrom\" in ACL condition \"%s\"", arg);
1537 return ERROR;
1538 }
1539 while (isspace(*opt)) opt++;
1540 se_mailfrom = string_copy(opt);
1541 }
1542
1543 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1544 {
1545 opt += 19;
1546 while (isspace(*opt)) opt++;
1547 if (*opt++ != '=')
1548 {
1549 *log_msgptr = string_sprintf("'=' expected after "
1550 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1551 return ERROR;
1552 }
1553 while (isspace(*opt)) opt++;
1554 pm_mailfrom = string_copy(opt);
1555 }
1556
1557 else if (strncmpic(opt, US"maxwait", 7) == 0)
1558 {
1559 opt += 7;
1560 while (isspace(*opt)) opt++;
1561 if (*opt++ != '=')
1562 {
1563 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1564 "ACL condition \"%s\"", arg);
1565 return ERROR;
1566 }
1567 while (isspace(*opt)) opt++;
1568 callout_overall = readconf_readtime(opt, 0, FALSE);
1569 if (callout_overall < 0)
1570 {
1571 *log_msgptr = string_sprintf("bad time value in ACL condition "
1572 "\"verify %s\"", arg);
1573 return ERROR;
1574 }
1575 }
1576 else if (strncmpic(opt, US"connect", 7) == 0)
1577 {
1578 opt += 7;
1579 while (isspace(*opt)) opt++;
1580 if (*opt++ != '=')
1581 {
1582 *log_msgptr = string_sprintf("'=' expected after "
1583 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1584 return ERROR;
1585 }
1586 while (isspace(*opt)) opt++;
1587 callout_connect = readconf_readtime(opt, 0, FALSE);
1588 if (callout_connect < 0)
1589 {
1590 *log_msgptr = string_sprintf("bad time value in ACL condition "
1591 "\"verify %s\"", arg);
1592 return ERROR;
1593 }
1594 }
1595 else /* Plain time is callout connect/command timeout */
1596 {
1597 callout = readconf_readtime(opt, 0, FALSE);
1598 if (callout < 0)
1599 {
1600 *log_msgptr = string_sprintf("bad time value in ACL condition "
1601 "\"verify %s\"", arg);
1602 return ERROR;
1603 }
1604 }
1605 }
1606 }
1607 else
1608 {
1609 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1610 "ACL condition \"%s\"", arg);
1611 return ERROR;
1612 }
1613 }
1614 }
1615
1616 /* Option not recognized */
1617
1618 else
1619 {
1620 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1621 "condition \"verify %s\"", ss, arg);
1622 return ERROR;
1623 }
1624 }
1625
1626 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1627 (vopt_callout_recipsender|vopt_callout_recippmaster))
1628 {
1629 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1630 "for a recipient callout";
1631 return ERROR;
1632 }
1633
1634 /* Handle sender-in-header verification. Default the user message to the log
1635 message if giving out verification details. */
1636
1637 if (verify_header_sender)
1638 {
1639 int verrno;
1640 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1641 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1642 &verrno);
1643 if (rc != OK)
1644 {
1645 *basic_errno = verrno;
1646 if (smtp_return_error_details)
1647 {
1648 if (*user_msgptr == NULL && *log_msgptr != NULL)
1649 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1650 if (rc == DEFER) acl_temp_details = TRUE;
1651 }
1652 }
1653 }
1654
1655 /* Handle a sender address. The default is to verify *the* sender address, but
1656 optionally a different address can be given, for special requirements. If the
1657 address is empty, we are dealing with a bounce message that has no sender, so
1658 we cannot do any checking. If the real sender address gets rewritten during
1659 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1660 during message reception.
1661
1662 A list of verified "sender" addresses is kept to try to avoid doing to much
1663 work repetitively when there are multiple recipients in a message and they all
1664 require sender verification. However, when callouts are involved, it gets too
1665 complicated because different recipients may require different callout options.
1666 Therefore, we always do a full sender verify when any kind of callout is
1667 specified. Caching elsewhere, for instance in the DNS resolver and in the
1668 callout handling, should ensure that this is not terribly inefficient. */
1669
1670 else if (verify_sender_address != NULL)
1671 {
1672 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1673 != 0)
1674 {
1675 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1676 "sender verify callout";
1677 return ERROR;
1678 }
1679
1680 sender_vaddr = verify_checked_sender(verify_sender_address);
1681 if (sender_vaddr != NULL && /* Previously checked */
1682 callout <= 0) /* No callout needed this time */
1683 {
1684 /* If the "routed" flag is set, it means that routing worked before, so
1685 this check can give OK (the saved return code value, if set, belongs to a
1686 callout that was done previously). If the "routed" flag is not set, routing
1687 must have failed, so we use the saved return code. */
1688
1689 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1690 {
1691 rc = sender_vaddr->special_action;
1692 *basic_errno = sender_vaddr->basic_errno;
1693 }
1694 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1695 }
1696
1697 /* Do a new verification, and cache the result. The cache is used to avoid
1698 verifying the sender multiple times for multiple RCPTs when callouts are not
1699 specified (see comments above).
1700
1701 The cache is also used on failure to give details in response to the first
1702 RCPT that gets bounced for this reason. However, this can be suppressed by
1703 the no_details option, which sets the flag that says "this detail has already
1704 been sent". The cache normally contains just one address, but there may be
1705 more in esoteric circumstances. */
1706
1707 else
1708 {
1709 BOOL routed = TRUE;
1710 uschar *save_address_data = deliver_address_data;
1711
1712 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1713 if (no_details) setflag(sender_vaddr, af_sverify_told);
1714 if (verify_sender_address[0] != 0)
1715 {
1716 /* If this is the real sender address, save the unrewritten version
1717 for use later in receive. Otherwise, set a flag so that rewriting the
1718 sender in verify_address() does not update sender_address. */
1719
1720 if (verify_sender_address == sender_address)
1721 sender_address_unrewritten = sender_address;
1722 else
1723 verify_options |= vopt_fake_sender;
1724
1725 /* The recipient, qualify, and expn options are never set in
1726 verify_options. */
1727
1728 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1729 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1730
1731 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1732
1733 if (rc == OK)
1734 {
1735 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1736 {
1737 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1738 verify_sender_address, sender_vaddr->address);
1739 }
1740 else
1741 {
1742 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1743 verify_sender_address);
1744 }
1745 }
1746 else *basic_errno = sender_vaddr->basic_errno;
1747 }
1748 else rc = OK; /* Null sender */
1749
1750 /* Cache the result code */
1751
1752 if (routed) setflag(sender_vaddr, af_verify_routed);
1753 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1754 sender_vaddr->special_action = rc;
1755 sender_vaddr->next = sender_verified_list;
1756 sender_verified_list = sender_vaddr;
1757
1758 /* Restore the recipient address data, which might have been clobbered by
1759 the sender verification. */
1760
1761 deliver_address_data = save_address_data;
1762 }
1763
1764 /* Put the sender address_data value into $sender_address_data */
1765
1766 sender_address_data = sender_vaddr->p.address_data;
1767 }
1768
1769 /* A recipient address just gets a straightforward verify; again we must handle
1770 the DEFER overrides. */
1771
1772 else
1773 {
1774 address_item addr2;
1775
1776 /* We must use a copy of the address for verification, because it might
1777 get rewritten. */
1778
1779 addr2 = *addr;
1780 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1781 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1782 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1783
1784 *log_msgptr = addr2.message;
1785 *user_msgptr = (addr2.user_message != NULL)?
1786 addr2.user_message : addr2.message;
1787 *basic_errno = addr2.basic_errno;
1788
1789 /* Make $address_data visible */
1790 deliver_address_data = addr2.p.address_data;
1791 }
1792
1793 /* We have a result from the relevant test. Handle defer overrides first. */
1794
1795 if (rc == DEFER && (defer_ok ||
1796 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1797 {
1798 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1799 defer_ok? "defer_ok" : "callout_defer_ok");
1800 rc = OK;
1801 }
1802
1803 /* If we've failed a sender, set up a recipient message, and point
1804 sender_verified_failed to the address item that actually failed. */
1805
1806 if (rc != OK && verify_sender_address != NULL)
1807 {
1808 if (rc != DEFER)
1809 {
1810 *log_msgptr = *user_msgptr = US"Sender verify failed";
1811 }
1812 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1813 {
1814 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1815 }
1816 else
1817 {
1818 *log_msgptr = US"Could not complete sender verify callout";
1819 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
1820 *log_msgptr;
1821 }
1822
1823 sender_verified_failed = sender_vaddr;
1824 }
1825
1826 /* Verifying an address messes up the values of $domain and $local_part,
1827 so reset them before returning if this is a RCPT ACL. */
1828
1829 if (addr != NULL)
1830 {
1831 deliver_domain = addr->domain;
1832 deliver_localpart = addr->local_part;
1833 }
1834 return rc;
1835
1836 /* Syntax errors in the verify argument come here. */
1837
1838 BAD_VERIFY:
1839 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
1840 "\"helo\", \"header_syntax\", \"header_sender\" or "
1841 "\"reverse_host_lookup\" at start of ACL condition "
1842 "\"verify %s\"", arg);
1843 return ERROR;
1844
1845 /* Options supplied when not allowed come here */
1846
1847 NO_OPTIONS:
1848 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1849 "(this verify item has no options)", arg);
1850 return ERROR;
1851 }
1852
1853
1854
1855
1856 /*************************************************
1857 * Check argument for control= modifier *
1858 *************************************************/
1859
1860 /* Called from acl_check_condition() below
1861
1862 Arguments:
1863 arg the argument string for control=
1864 pptr set to point to the terminating character
1865 where which ACL we are in
1866 log_msgptr for error messages
1867
1868 Returns: CONTROL_xxx value
1869 */
1870
1871 static int
1872 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
1873 {
1874 int len;
1875 control_def *d;
1876
1877 for (d = controls_list;
1878 d < controls_list + sizeof(controls_list)/sizeof(control_def);
1879 d++)
1880 {
1881 len = Ustrlen(d->name);
1882 if (Ustrncmp(d->name, arg, len) == 0) break;
1883 }
1884
1885 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
1886 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
1887 {
1888 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
1889 return CONTROL_ERROR;
1890 }
1891
1892 *pptr = arg + len;
1893 return d->value;
1894 }
1895
1896
1897
1898 /*************************************************
1899 * Handle rate limiting *
1900 *************************************************/
1901
1902 /* Called by acl_check_condition() below to calculate the result
1903 of the ACL ratelimit condition.
1904
1905 Note that the return value might be slightly unexpected: if the
1906 sender's rate is above the limit then the result is OK. This is
1907 similar to the dnslists condition, and is so that you can write
1908 ACL clauses like: defer ratelimit = 15 / 1h
1909
1910 Arguments:
1911 arg the option string for ratelimit=
1912 log_msgptr for error messages
1913
1914 Returns: OK - Sender's rate is above limit
1915 FAIL - Sender's rate is below limit
1916 DEFER - Problem opening ratelimit database
1917 ERROR - Syntax error in options.
1918 */
1919
1920 static int
1921 acl_ratelimit(uschar *arg, uschar **log_msgptr)
1922 {
1923 double limit, period;
1924 uschar *ss, *key;
1925 int sep = '/';
1926 BOOL have_key = FALSE, leaky = FALSE, strict = FALSE;
1927 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
1928 int old_pool, rc;
1929 tree_node **anchor, *t;
1930 open_db dbblock, *dbm;
1931 dbdata_ratelimit *dbd;
1932 struct timeval tv;
1933
1934 /* Parse the first two options and record their values in expansion
1935 variables. These variables allow the configuration to have informative
1936 error messages based on rate limits obtained from a table lookup. */
1937
1938 /* First is the maximum number of messages per period and maximum burst
1939 size, which must be greater than or equal to zero. Zero is useful for
1940 rate measurement as opposed to rate limiting. */
1941
1942 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
1943 if (sender_rate_limit == NULL)
1944 limit = -1.0;
1945 else
1946 {
1947 limit = Ustrtod(sender_rate_limit, &ss);
1948 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
1949 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
1950 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
1951 }
1952 if (limit < 0.0 || *ss != 0)
1953 {
1954 *log_msgptr = string_sprintf("syntax error in argument for "
1955 "\"ratelimit\" condition: \"%s\" is not a positive number",
1956 sender_rate_limit);
1957 return ERROR;
1958 }
1959
1960 /* We use the rest of the argument list following the limit as the
1961 lookup key, because it doesn't make sense to use the same stored data
1962 if the period or options are different. */
1963
1964 key = arg;
1965
1966 /* Second is the rate measurement period and exponential smoothing time
1967 constant. This must be strictly greater than zero, because zero leads to
1968 run-time division errors. */
1969
1970 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
1971 if (sender_rate_period == NULL) period = -1.0;
1972 else period = readconf_readtime(sender_rate_period, 0, FALSE);
1973 if (period <= 0.0)
1974 {
1975 *log_msgptr = string_sprintf("syntax error in argument for "
1976 "\"ratelimit\" condition: \"%s\" is not a time value",
1977 sender_rate_period);
1978 return ERROR;
1979 }
1980
1981 /* Parse the other options. Should we check if the per_* options are being
1982 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
1983
1984 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
1985 != NULL)
1986 {
1987 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
1988 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
1989 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
1990 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
1991 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
1992 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
1993 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
1994 else have_key = TRUE;
1995 }
1996 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
1997 {
1998 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
1999 return ERROR;
2000 }
2001
2002 /* Default option values */
2003 if (!strict) leaky = TRUE;
2004 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
2005
2006 /* If there is no explicit key, use the sender_host_address. If there is no
2007 sender_host_address (e.g. -bs or acl_not_smtp) then we simply omit it. */
2008
2009 if (!have_key && sender_host_address != NULL)
2010 key = string_sprintf("%s / %s", key, sender_host_address);
2011
2012 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2013 limit, period, key);
2014
2015 /* If we are dealing with rate limits per connection, per message, or per byte,
2016 see if we have already computed the rate by looking in the relevant tree. For
2017 per-connection rate limiting, store tree nodes and dbdata in the permanent pool
2018 so that they survive across resets. */
2019
2020 anchor = NULL;
2021 old_pool = store_pool;
2022
2023 if (per_conn)
2024 {
2025 anchor = &ratelimiters_conn;
2026 store_pool = POOL_PERM;
2027 }
2028 if (per_mail || per_byte)
2029 anchor = &ratelimiters_mail;
2030
2031 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2032 {
2033 dbd = t->data.ptr;
2034 /* The following few lines duplicate some of the code below. */
2035 if (dbd->rate < limit) rc = FAIL;
2036 else rc = OK;
2037 store_pool = old_pool;
2038 sender_rate = string_sprintf("%.1f", dbd->rate);
2039 HDEBUG(D_acl)
2040 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2041 return rc;
2042 }
2043
2044 /* We aren't using a pre-computed rate, so get a previously recorded
2045 rate from the database, update it, and write it back. If there's no
2046 previous rate for this key, create one. */
2047
2048 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2049 if (dbm == NULL)
2050 {
2051 store_pool = old_pool;
2052 sender_rate = NULL;
2053 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2054 *log_msgptr = US"ratelimit database not available";
2055 return DEFER;
2056 }
2057 dbd = dbfn_read(dbm, key);
2058
2059 gettimeofday(&tv, NULL);
2060
2061 if (dbd == NULL)
2062 {
2063 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2064 dbd = store_get(sizeof(dbdata_ratelimit));
2065 dbd->time_stamp = tv.tv_sec;
2066 dbd->time_usec = tv.tv_usec;
2067 dbd->rate = 0.0;
2068 }
2069 else
2070 {
2071 /* The smoothed rate is computed using an exponentially weighted moving
2072 average adjusted for variable sampling intervals. The standard EWMA for
2073 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2074 where f() is the measured value and f'() is the smoothed value.
2075
2076 Old data decays out of the smoothed value exponentially, such that data n
2077 samples old is multiplied by a^n. The exponential decay time constant p
2078 is defined such that data p samples old is multiplied by 1/e, which means
2079 that a = exp(-1/p). We can maintain the same time constant for a variable
2080 sampling interval i by using a = exp(-i/p).
2081
2082 The rate we are measuring is messages per period, suitable for directly
2083 comparing with the limit. The average rate between now and the previous
2084 message is period / interval, which we feed into the EWMA as the sample.
2085
2086 It turns out that the number of messages required for the smoothed rate
2087 to reach the limit when they are sent in a burst is equal to the limit.
2088 This can be seen by analysing the value of the smoothed rate after N
2089 messages sent at even intervals. Let k = (1 - a) * p/i
2090
2091 rate_1 = (1 - a) * p/i + a * rate_0
2092 = k + a * rate_0
2093 rate_2 = k + a * rate_1
2094 = k + a * k + a^2 * rate_0
2095 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2096 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2097 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2098 = rate_0 * a^N + p/i * (1 - a^N)
2099
2100 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2101
2102 rate_N = p/i + (rate_0 - p/i) * a^N
2103 a^N = (rate_N - p/i) / (rate_0 - p/i)
2104 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2105 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2106
2107 Numerical analysis of the above equation, setting the computed rate to
2108 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2109 rates, p/i, the number of messages N = limit. So limit serves as both the
2110 maximum rate measured in messages per period, and the maximum number of
2111 messages that can be sent in a fast burst. */
2112
2113 double this_time = (double)tv.tv_sec
2114 + (double)tv.tv_usec / 1000000.0;
2115 double prev_time = (double)dbd->time_stamp
2116 + (double)dbd->time_usec / 1000000.0;
2117 double interval = this_time - prev_time;
2118
2119 double i_over_p = interval / period;
2120 double a = exp(-i_over_p);
2121
2122 /* We must avoid division by zero, and deal gracefully with the clock going
2123 backwards. If we blunder ahead when time is in reverse then the computed
2124 rate will become bogusly huge. Clamp i/p to a very small number instead. */
2125
2126 if (i_over_p <= 0.0) i_over_p = 1e-9;
2127
2128 dbd->time_stamp = tv.tv_sec;
2129 dbd->time_usec = tv.tv_usec;
2130
2131 /* If we are measuring the rate in bytes per period, multiply the
2132 measured rate by the message size. If we don't know the message size
2133 then it's safe to just use a value of zero and let the recorded rate
2134 decay as if nothing happened. */
2135
2136 if (per_byte)
2137 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2138 * (1 - a) / i_over_p + a * dbd->rate;
2139 else
2140 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2141 }
2142
2143 /* Clients sending at the limit are considered to be over the limit. This
2144 matters for edge cases such the first message sent by a client (which gets
2145 the initial rate of 0.0) when the rate limit is zero (i.e. the client should
2146 be completely blocked). */
2147
2148 if (dbd->rate < limit) rc = FAIL;
2149 else rc = OK;
2150
2151 /* Update the state if the rate is low or if we are being strict. If we
2152 are in leaky mode and the sender's rate is too high, we do not update
2153 the recorded rate in order to avoid an over-aggressive sender's retry
2154 rate preventing them from getting any email through. */
2155
2156 if (rc == FAIL || !leaky)
2157 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2158 dbfn_close(dbm);
2159
2160 /* Store the result in the tree for future reference, if necessary. */
2161
2162 if (anchor != NULL)
2163 {
2164 t = store_get(sizeof(tree_node) + Ustrlen(key));
2165 t->data.ptr = dbd;
2166 Ustrcpy(t->name, key);
2167 (void)tree_insertnode(anchor, t);
2168 }
2169
2170 /* We create the formatted version of the sender's rate very late in
2171 order to ensure that it is done using the correct storage pool. */
2172
2173 store_pool = old_pool;
2174 sender_rate = string_sprintf("%.1f", dbd->rate);
2175
2176 HDEBUG(D_acl)
2177 debug_printf("ratelimit computed rate %s\n", sender_rate);
2178
2179 return rc;
2180 }
2181
2182
2183
2184 /*************************************************
2185 * Handle conditions/modifiers on an ACL item *
2186 *************************************************/
2187
2188 /* Called from acl_check() below.
2189
2190 Arguments:
2191 verb ACL verb
2192 cb ACL condition block - if NULL, result is OK
2193 where where called from
2194 addr the address being checked for RCPT, or NULL
2195 level the nesting level
2196 epp pointer to pass back TRUE if "endpass" encountered
2197 (applies only to "accept" and "discard")
2198 user_msgptr user message pointer
2199 log_msgptr log message pointer
2200 basic_errno pointer to where to put verify error
2201
2202 Returns: OK - all conditions are met
2203 DISCARD - an "acl" condition returned DISCARD - only allowed
2204 for "accept" or "discard" verbs
2205 FAIL - at least one condition fails
2206 FAIL_DROP - an "acl" condition returned FAIL_DROP
2207 DEFER - can't tell at the moment (typically, lookup defer,
2208 but can be temporary callout problem)
2209 ERROR - ERROR from nested ACL or expansion failure or other
2210 error
2211 */
2212
2213 static int
2214 acl_check_condition(int verb, acl_condition_block *cb, int where,
2215 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2216 uschar **log_msgptr, int *basic_errno)
2217 {
2218 uschar *user_message = NULL;
2219 uschar *log_message = NULL;
2220 uschar *p;
2221 int rc = OK;
2222 #ifdef WITH_CONTENT_SCAN
2223 int sep = '/';
2224 #endif
2225
2226 for (; cb != NULL; cb = cb->next)
2227 {
2228 uschar *arg;
2229 int control_type;
2230
2231 /* The message and log_message items set up messages to be used in
2232 case of rejection. They are expanded later. */
2233
2234 if (cb->type == ACLC_MESSAGE)
2235 {
2236 user_message = cb->arg;
2237 continue;
2238 }
2239
2240 if (cb->type == ACLC_LOG_MESSAGE)
2241 {
2242 log_message = cb->arg;
2243 continue;
2244 }
2245
2246 /* The endpass "condition" just sets a flag to show it occurred. This is
2247 checked at compile time to be on an "accept" or "discard" item. */
2248
2249 if (cb->type == ACLC_ENDPASS)
2250 {
2251 *epp = TRUE;
2252 continue;
2253 }
2254
2255 /* For other conditions and modifiers, the argument is expanded now for some
2256 of them, but not for all, because expansion happens down in some lower level
2257 checking functions in some cases. */
2258
2259 if (cond_expand_at_top[cb->type])
2260 {
2261 arg = expand_string(cb->arg);
2262 if (arg == NULL)
2263 {
2264 if (expand_string_forcedfail) continue;
2265 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2266 cb->arg, expand_string_message);
2267 return search_find_defer? DEFER : ERROR;
2268 }
2269 }
2270 else arg = cb->arg;
2271
2272 /* Show condition, and expanded condition if it's different */
2273
2274 HDEBUG(D_acl)
2275 {
2276 int lhswidth = 0;
2277 debug_printf("check %s%s %n",
2278 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2279 conditions[cb->type], &lhswidth);
2280
2281 if (cb->type == ACLC_SET)
2282 {
2283 int n = cb->u.varnumber;
2284 int t = (n < ACL_C_MAX)? 'c' : 'm';
2285 if (n >= ACL_C_MAX) n -= ACL_C_MAX;
2286 debug_printf("acl_%c%d ", t, n);
2287 lhswidth += 7;
2288 }
2289
2290 debug_printf("= %s\n", cb->arg);
2291
2292 if (arg != cb->arg)
2293 debug_printf("%.*s= %s\n", lhswidth,
2294 US" ", CS arg);
2295 }
2296
2297 /* Check that this condition makes sense at this time */
2298
2299 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2300 {
2301 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2302 cond_modifiers[cb->type]? "use" : "test",
2303 conditions[cb->type], acl_wherenames[where]);
2304 return ERROR;
2305 }
2306
2307 /* Run the appropriate test for each condition, or take the appropriate
2308 action for the remaining modifiers. */
2309
2310 switch(cb->type)
2311 {
2312 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2313 "discard" verb. */
2314
2315 case ACLC_ACL:
2316 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2317 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2318 {
2319 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2320 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2321 verbs[verb]);
2322 return ERROR;
2323 }
2324 break;
2325
2326 case ACLC_AUTHENTICATED:
2327 rc = (sender_host_authenticated == NULL)? FAIL :
2328 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2329 TRUE, NULL);
2330 break;
2331
2332 #ifdef EXPERIMENTAL_BRIGHTMAIL
2333 case ACLC_BMI_OPTIN:
2334 {
2335 int old_pool = store_pool;
2336 store_pool = POOL_PERM;
2337 bmi_current_optin = string_copy(arg);
2338 store_pool = old_pool;
2339 }
2340 break;
2341 #endif
2342
2343 case ACLC_CONDITION:
2344 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2345 rc = (Uatoi(arg) == 0)? FAIL : OK;
2346 else
2347 rc = (strcmpic(arg, US"no") == 0 ||
2348 strcmpic(arg, US"false") == 0)? FAIL :
2349 (strcmpic(arg, US"yes") == 0 ||
2350 strcmpic(arg, US"true") == 0)? OK : DEFER;
2351 if (rc == DEFER)
2352 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2353 break;
2354
2355 case ACLC_CONTROL:
2356 control_type = decode_control(arg, &p, where, log_msgptr);
2357
2358 /* Check if this control makes sense at this time */
2359
2360 if ((control_forbids[control_type] & (1 << where)) != 0)
2361 {
2362 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2363 controls[control_type], acl_wherenames[where]);
2364 return ERROR;
2365 }
2366
2367 switch(control_type)
2368 {
2369 #ifdef EXPERIMENTAL_BRIGHTMAIL
2370 case CONTROL_BMI_RUN:
2371 bmi_run = 1;
2372 break;
2373 #endif
2374 #ifdef EXPERIMENTAL_DOMAINKEYS
2375 case CONTROL_DK_VERIFY:
2376 dk_do_verify = 1;
2377 break;
2378 #endif
2379 case CONTROL_ERROR:
2380 return ERROR;
2381
2382 case CONTROL_CASEFUL_LOCAL_PART:
2383 deliver_localpart = addr->cc_local_part;
2384 break;
2385
2386 case CONTROL_CASELOWER_LOCAL_PART:
2387 deliver_localpart = addr->lc_local_part;
2388 break;
2389
2390 case CONTROL_ENFORCE_SYNC:
2391 smtp_enforce_sync = TRUE;
2392 break;
2393
2394 case CONTROL_NO_ENFORCE_SYNC:
2395 smtp_enforce_sync = FALSE;
2396 break;
2397
2398 #ifdef WITH_CONTENT_SCAN
2399 case CONTROL_NO_MBOX_UNSPOOL:
2400 no_mbox_unspool = TRUE;
2401 break;
2402 #endif
2403
2404 case CONTROL_NO_MULTILINE:
2405 no_multiline_responses = TRUE;
2406 break;
2407
2408 case CONTROL_FAKEDEFER:
2409 case CONTROL_FAKEREJECT:
2410 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2411 if (*p == '/')
2412 {
2413 uschar *pp = p + 1;
2414 while (*pp != 0) pp++;
2415 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2416 p = pp;
2417 }
2418 else
2419 {
2420 /* Explicitly reset to default string */
2421 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).";
2422 }
2423 break;
2424
2425 case CONTROL_FREEZE:
2426 deliver_freeze = TRUE;
2427 deliver_frozen_at = time(NULL);
2428 break;
2429
2430 case CONTROL_QUEUE_ONLY:
2431 queue_only_policy = TRUE;
2432 break;
2433
2434 case CONTROL_SUBMISSION:
2435 originator_name = US"";
2436 submission_mode = TRUE;
2437 while (*p == '/')
2438 {
2439 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2440 {
2441 p += 14;
2442 active_local_sender_retain = TRUE;
2443 active_local_from_check = FALSE;
2444 }
2445 else if (Ustrncmp(p, "/domain=", 8) == 0)
2446 {
2447 uschar *pp = p + 8;
2448 while (*pp != 0 && *pp != '/') pp++;
2449 submission_domain = string_copyn(p+8, pp-p-8);
2450 p = pp;
2451 }
2452 else if (Ustrncmp(p, "/name=", 6) == 0)
2453 {
2454 uschar *pp = p + 6;
2455 while (*pp != 0 && *pp != '/') pp++;
2456 originator_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2457 big_buffer, big_buffer_size));
2458 p = pp;
2459 }
2460 else break;
2461 }
2462 if (*p != 0)
2463 {
2464 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2465 return ERROR;
2466 }
2467 break;
2468 }
2469 break;
2470
2471 #ifdef WITH_CONTENT_SCAN
2472 case ACLC_DECODE:
2473 rc = mime_decode(&arg);
2474 break;
2475 #endif
2476
2477 case ACLC_DELAY:
2478 {
2479 int delay = readconf_readtime(arg, 0, FALSE);
2480 if (delay < 0)
2481 {
2482 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2483 "modifier: \"%s\" is not a time value", arg);
2484 return ERROR;
2485 }
2486 else
2487 {
2488 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2489 delay);
2490 if (host_checking)
2491 {
2492 HDEBUG(D_acl)
2493 debug_printf("delay skipped in -bh checking mode\n");
2494 }
2495
2496 /* It appears to be impossible to detect that a TCP/IP connection has
2497 gone away without reading from it. This means that we cannot shorten
2498 the delay below if the client goes away, because we cannot discover
2499 that the client has closed its end of the connection. (The connection
2500 is actually in a half-closed state, waiting for the server to close its
2501 end.) It would be nice to be able to detect this state, so that the
2502 Exim process is not held up unnecessarily. However, it seems that we
2503 can't. The poll() function does not do the right thing, and in any case
2504 it is not always available.
2505
2506 NOTE: If ever this state of affairs changes, remember that we may be
2507 dealing with stdin/stdout here, in addition to TCP/IP connections.
2508 Whatever is done must work in both cases. To detected the stdin/stdout
2509 case, check for smtp_in or smtp_out being NULL. */
2510
2511 else
2512 {
2513 while (delay > 0) delay = sleep(delay);
2514 }
2515 }
2516 }
2517 break;
2518
2519 #ifdef WITH_OLD_DEMIME
2520 case ACLC_DEMIME:
2521 rc = demime(&arg);
2522 break;
2523 #endif
2524
2525 #ifdef EXPERIMENTAL_DOMAINKEYS
2526 case ACLC_DK_DOMAIN_SOURCE:
2527 if (dk_verify_block == NULL) { rc = FAIL; break; };
2528 /* check header source of domain against given string */
2529 switch (dk_verify_block->address_source) {
2530 case DK_EXIM_ADDRESS_FROM_FROM:
2531 rc = match_isinlist(US"from", &arg, 0, NULL,
2532 NULL, MCL_STRING, TRUE, NULL);
2533 break;
2534 case DK_EXIM_ADDRESS_FROM_SENDER:
2535 rc = match_isinlist(US"sender", &arg, 0, NULL,
2536 NULL, MCL_STRING, TRUE, NULL);
2537 break;
2538 case DK_EXIM_ADDRESS_NONE:
2539 rc = match_isinlist(US"none", &arg, 0, NULL,
2540 NULL, MCL_STRING, TRUE, NULL);
2541 break;
2542 }
2543 break;
2544 case ACLC_DK_POLICY:
2545 if (dk_verify_block == NULL) { rc = FAIL; break; };
2546 /* check policy against given string, default FAIL */
2547 rc = FAIL;
2548 if (dk_verify_block->signsall)
2549 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2550 NULL, MCL_STRING, TRUE, NULL);
2551 if (dk_verify_block->testing)
2552 rc = match_isinlist(US"testing", &arg, 0, NULL,
2553 NULL, MCL_STRING, TRUE, NULL);
2554 break;
2555 case ACLC_DK_SENDER_DOMAINS:
2556 if (dk_verify_block == NULL) { rc = FAIL; break; };
2557 if (dk_verify_block->domain != NULL)
2558 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2559 NULL, MCL_DOMAIN, TRUE, NULL);
2560 else rc = FAIL;
2561 break;
2562 case ACLC_DK_SENDER_LOCAL_PARTS:
2563 if (dk_verify_block == NULL) { rc = FAIL; break; };
2564 if (dk_verify_block->local_part != NULL)
2565 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2566 NULL, MCL_LOCALPART, TRUE, NULL);
2567 else rc = FAIL;
2568 break;
2569 case ACLC_DK_SENDERS:
2570 if (dk_verify_block == NULL) { rc = FAIL; break; };
2571 if (dk_verify_block->address != NULL)
2572 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2573 else rc = FAIL;
2574 break;
2575 case ACLC_DK_STATUS:
2576 if (dk_verify_block == NULL) { rc = FAIL; break; };
2577 if (dk_verify_block->result > 0) {
2578 switch(dk_verify_block->result) {
2579 case DK_EXIM_RESULT_BAD_FORMAT:
2580 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2581 NULL, MCL_STRING, TRUE, NULL);
2582 break;
2583 case DK_EXIM_RESULT_NO_KEY:
2584 rc = match_isinlist(US"no key", &arg, 0, NULL,
2585 NULL, MCL_STRING, TRUE, NULL);
2586 break;
2587 case DK_EXIM_RESULT_NO_SIGNATURE:
2588 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2589 NULL, MCL_STRING, TRUE, NULL);
2590 break;
2591 case DK_EXIM_RESULT_REVOKED:
2592 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2593 NULL, MCL_STRING, TRUE, NULL);
2594 break;
2595 case DK_EXIM_RESULT_NON_PARTICIPANT:
2596 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2597 NULL, MCL_STRING, TRUE, NULL);
2598 break;
2599 case DK_EXIM_RESULT_GOOD:
2600 rc = match_isinlist(US"good", &arg, 0, NULL,
2601 NULL, MCL_STRING, TRUE, NULL);
2602 break;
2603 case DK_EXIM_RESULT_BAD:
2604 rc = match_isinlist(US"bad", &arg, 0, NULL,
2605 NULL, MCL_STRING, TRUE, NULL);
2606 break;
2607 }
2608 }
2609 break;
2610 #endif
2611
2612 case ACLC_DNSLISTS:
2613 rc = verify_check_dnsbl(&arg);
2614 break;
2615
2616 case ACLC_DOMAINS:
2617 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2618 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2619 break;
2620
2621 /* The value in tls_cipher is the full cipher name, for example,
2622 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2623 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2624 what may in practice come out of the SSL library - which at the time of
2625 writing is poorly documented. */
2626
2627 case ACLC_ENCRYPTED:
2628 if (tls_cipher == NULL) rc = FAIL; else
2629 {
2630 uschar *endcipher = NULL;
2631 uschar *cipher = Ustrchr(tls_cipher, ':');
2632 if (cipher == NULL) cipher = tls_cipher; else
2633 {
2634 endcipher = Ustrchr(++cipher, ':');
2635 if (endcipher != NULL) *endcipher = 0;
2636 }
2637 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2638 if (endcipher != NULL) *endcipher = ':';
2639 }
2640 break;
2641
2642 /* Use verify_check_this_host() instead of verify_check_host() so that
2643 we can pass over &host_data to catch any looked up data. Once it has been
2644 set, it retains its value so that it's still there if another ACL verb
2645 comes through here and uses the cache. However, we must put it into
2646 permanent store in case it is also expected to be used in a subsequent
2647 message in the same SMTP connection. */
2648
2649 case ACLC_HOSTS:
2650 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2651 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2652 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2653 break;
2654
2655 case ACLC_LOCAL_PARTS:
2656 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2657 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2658 &deliver_localpart_data);
2659 break;
2660
2661 case ACLC_LOGWRITE:
2662 {
2663 int logbits = 0;
2664 uschar *s = arg;
2665 if (*s == ':')
2666 {
2667 s++;
2668 while (*s != ':')
2669 {
2670 if (Ustrncmp(s, "main", 4) == 0)
2671 { logbits |= LOG_MAIN; s += 4; }
2672 else if (Ustrncmp(s, "panic", 5) == 0)
2673 { logbits |= LOG_PANIC; s += 5; }
2674 else if (Ustrncmp(s, "reject", 6) == 0)
2675 { logbits |= LOG_REJECT; s += 6; }
2676 else
2677 {
2678 logbits = LOG_MAIN|LOG_PANIC;
2679 s = string_sprintf(":unknown log name in \"%s\" in "
2680 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2681 }
2682 if (*s == ',') s++;
2683 }
2684 s++;
2685 }
2686 while (isspace(*s)) s++;
2687 if (logbits == 0) logbits = LOG_MAIN;
2688 log_write(0, logbits, "%s", string_printing(s));
2689 }
2690 break;
2691
2692 #ifdef WITH_CONTENT_SCAN
2693 case ACLC_MALWARE:
2694 {
2695 /* Seperate the regular expression and any optional parameters. */
2696 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2697 /* Run the malware backend. */
2698 rc = malware(&ss);
2699 /* Modify return code based upon the existance of options. */
2700 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2701 != NULL) {
2702 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2703 {
2704 /* FAIL so that the message is passed to the next ACL */
2705 rc = FAIL;
2706 }
2707 }
2708 }
2709 break;
2710
2711 case ACLC_MIME_REGEX:
2712 rc = mime_regex(&arg);
2713 break;
2714 #endif
2715
2716 case ACLC_RATELIMIT:
2717 rc = acl_ratelimit(arg, log_msgptr);
2718 break;
2719
2720 case ACLC_RECIPIENTS:
2721 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
2722 &recipient_data);
2723 break;
2724
2725 #ifdef WITH_CONTENT_SCAN
2726 case ACLC_REGEX:
2727 rc = regex(&arg);
2728 break;
2729 #endif
2730
2731 case ACLC_SENDER_DOMAINS:
2732 {
2733 uschar *sdomain;
2734 sdomain = Ustrrchr(sender_address, '@');
2735 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
2736 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
2737 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
2738 }
2739 break;
2740
2741 case ACLC_SENDERS:
2742 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
2743 sender_address_cache, -1, 0, &sender_data);
2744 break;
2745
2746 /* Connection variables must persist forever */
2747
2748 case ACLC_SET:
2749 {
2750 int old_pool = store_pool;
2751 if (cb->u.varnumber < ACL_C_MAX) store_pool = POOL_PERM;
2752 acl_var[cb->u.varnumber] = string_copy(arg);
2753 store_pool = old_pool;
2754 }
2755 break;
2756
2757 #ifdef WITH_CONTENT_SCAN
2758 case ACLC_SPAM:
2759 {
2760 /* Seperate the regular expression and any optional parameters. */
2761 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2762 /* Run the spam backend. */
2763 rc = spam(&ss);
2764 /* Modify return code based upon the existance of options. */
2765 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2766 != NULL) {
2767 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2768 {
2769 /* FAIL so that the message is passed to the next ACL */
2770 rc = FAIL;
2771 }
2772 }
2773 }
2774 break;
2775 #endif
2776
2777 #ifdef EXPERIMENTAL_SPF
2778 case ACLC_SPF:
2779 rc = spf_process(&arg, sender_address);
2780 break;
2781 #endif
2782
2783 /* If the verb is WARN, discard any user message from verification, because
2784 such messages are SMTP responses, not header additions. The latter come
2785 only from explicit "message" modifiers. However, put the user message into
2786 $acl_verify_message so it can be used in subsequent conditions or modifiers
2787 (until something changes it). */
2788
2789 case ACLC_VERIFY:
2790 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
2791 acl_verify_message = *user_msgptr;
2792 if (verb == ACL_WARN) *user_msgptr = NULL;
2793 break;
2794
2795 default:
2796 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
2797 "condition %d", cb->type);
2798 break;
2799 }
2800
2801 /* If a condition was negated, invert OK/FAIL. */
2802
2803 if (!cond_modifiers[cb->type] && cb->u.negated)
2804 {
2805 if (rc == OK) rc = FAIL;
2806 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
2807 }
2808
2809 if (rc != OK) break; /* Conditions loop */
2810 }
2811
2812
2813 /* If the result is the one for which "message" and/or "log_message" are used,
2814 handle the values of these options. Most verbs have but a single return for
2815 which the messages are relevant, but for "discard", it's useful to have the log
2816 message both when it succeeds and when it fails. Also, for an "accept" that
2817 appears in a QUIT ACL, we want to handle the user message. Since only "accept"
2818 and "warn" are permitted in that ACL, we don't need to test the verb.
2819
2820 These modifiers act in different ways:
2821
2822 "message" is a user message that will be included in an SMTP response. Unless
2823 it is empty, it overrides any previously set user message.
2824
2825 "log_message" is a non-user message, and it adds to any existing non-user
2826 message that is already set.
2827
2828 If there isn't a log message set, we make it the same as the user message. */
2829
2830 if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] ||
2831 (verb == ACL_DISCARD && rc == OK) ||
2832 (where == ACL_WHERE_QUIT))
2833 {
2834 uschar *expmessage;
2835
2836 /* If the verb is "warn", messages generated by conditions (verification or
2837 nested ACLs) are discarded. Only messages specified at this level are used.
2838 However, the value of an existing message is available in $acl_verify_message
2839 during expansions. */
2840
2841 uschar *old_user_msgptr = *user_msgptr;
2842 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
2843
2844 if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL;
2845
2846 if (user_message != NULL)
2847 {
2848 acl_verify_message = old_user_msgptr;
2849 expmessage = expand_string(user_message);
2850 if (expmessage == NULL)
2851 {
2852 if (!expand_string_forcedfail)
2853 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2854 user_message, expand_string_message);
2855 }
2856 else if (expmessage[0] != 0) *user_msgptr = expmessage;
2857 }
2858
2859 if (log_message != NULL)
2860 {
2861 acl_verify_message = old_log_msgptr;
2862 expmessage = expand_string(log_message);
2863 if (expmessage == NULL)
2864 {
2865 if (!expand_string_forcedfail)
2866 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2867 log_message, expand_string_message);
2868 }
2869 else if (expmessage[0] != 0)
2870 {
2871 *log_msgptr = (*log_msgptr == NULL)? expmessage :
2872 string_sprintf("%s: %s", expmessage, *log_msgptr);
2873 }
2874 }
2875
2876 /* If no log message, default it to the user message */
2877
2878 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
2879 }
2880
2881 acl_verify_message = NULL;
2882 return rc;
2883 }
2884
2885
2886
2887
2888
2889 /*************************************************
2890 * Get line from a literal ACL *
2891 *************************************************/
2892
2893 /* This function is passed to acl_read() in order to extract individual lines
2894 of a literal ACL, which we access via static pointers. We can destroy the
2895 contents because this is called only once (the compiled ACL is remembered).
2896
2897 This code is intended to treat the data in the same way as lines in the main
2898 Exim configuration file. That is:
2899
2900 . Leading spaces are ignored.
2901
2902 . A \ at the end of a line is a continuation - trailing spaces after the \
2903 are permitted (this is because I don't believe in making invisible things
2904 significant). Leading spaces on the continued part of a line are ignored.
2905
2906 . Physical lines starting (significantly) with # are totally ignored, and
2907 may appear within a sequence of backslash-continued lines.
2908
2909 . Blank lines are ignored, but will end a sequence of continuations.
2910
2911 Arguments: none
2912 Returns: a pointer to the next line
2913 */
2914
2915
2916 static uschar *acl_text; /* Current pointer in the text */
2917 static uschar *acl_text_end; /* Points one past the terminating '0' */
2918
2919
2920 static uschar *
2921 acl_getline(void)
2922 {
2923 uschar *yield;
2924
2925 /* This loop handles leading blank lines and comments. */
2926
2927 for(;;)
2928 {
2929 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
2930 if (*acl_text == 0) return NULL; /* No more data */
2931 yield = acl_text; /* Potential data line */
2932
2933 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2934
2935 /* If we hit the end before a newline, we have the whole logical line. If
2936 it's a comment, there's no more data to be given. Otherwise, yield it. */
2937
2938 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
2939
2940 /* After reaching a newline, end this loop if the physical line does not
2941 start with '#'. If it does, it's a comment, and the loop continues. */
2942
2943 if (*yield != '#') break;
2944 }
2945
2946 /* This loop handles continuations. We know we have some real data, ending in
2947 newline. See if there is a continuation marker at the end (ignoring trailing
2948 white space). We know that *yield is not white space, so no need to test for
2949 cont > yield in the backwards scanning loop. */
2950
2951 for(;;)
2952 {
2953 uschar *cont;
2954 for (cont = acl_text - 1; isspace(*cont); cont--);
2955
2956 /* If no continuation follows, we are done. Mark the end of the line and
2957 return it. */
2958
2959 if (*cont != '\\')
2960 {
2961 *acl_text++ = 0;
2962 return yield;
2963 }
2964
2965 /* We have encountered a continuation. Skip over whitespace at the start of
2966 the next line, and indeed the whole of the next line or lines if they are
2967 comment lines. */
2968
2969 for (;;)
2970 {
2971 while (*(++acl_text) == ' ' || *acl_text == '\t');
2972 if (*acl_text != '#') break;
2973 while (*(++acl_text) != 0 && *acl_text != '\n');
2974 }
2975
2976 /* We have the start of a continuation line. Move all the rest of the data
2977 to join onto the previous line, and then find its end. If the end is not a
2978 newline, we are done. Otherwise loop to look for another continuation. */
2979
2980 memmove(cont, acl_text, acl_text_end - acl_text);
2981 acl_text_end -= acl_text - cont;
2982 acl_text = cont;
2983 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2984 if (*acl_text == 0) return yield;
2985 }
2986
2987 /* Control does not reach here */
2988 }
2989
2990
2991
2992
2993
2994 /*************************************************
2995 * Check access using an ACL *
2996 *************************************************/
2997
2998 /* This function is called from address_check. It may recurse via
2999 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3000 passed as a string which is expanded. A forced failure implies no access check
3001 is required. If the result is a single word, it is taken as the name of an ACL
3002 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3003 text, complete with newlines, and parsed as such. In both cases, the ACL check
3004 is then run. This function uses an auxiliary function for acl_read() to call
3005 for reading individual lines of a literal ACL. This is acl_getline(), which
3006 appears immediately above.
3007
3008 Arguments:
3009 where where called from
3010 addr address item when called from RCPT; otherwise NULL
3011 s the input string; NULL is the same as an empty ACL => DENY
3012 level the nesting level
3013 user_msgptr where to put a user error (for SMTP response)
3014 log_msgptr where to put a logging message (not for SMTP response)
3015
3016 Returns: OK access is granted
3017 DISCARD access is apparently granted...
3018 FAIL access is denied
3019 FAIL_DROP access is denied; drop the connection
3020 DEFER can't tell at the moment
3021 ERROR disaster
3022 */
3023
3024 static int
3025 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3026 uschar **user_msgptr, uschar **log_msgptr)
3027 {
3028 int fd = -1;
3029 acl_block *acl = NULL;
3030 uschar *acl_name = US"inline ACL";
3031 uschar *ss;
3032
3033 /* Catch configuration loops */
3034
3035 if (level > 20)
3036 {
3037 *log_msgptr = US"ACL nested too deep: possible loop";
3038 return ERROR;
3039 }
3040
3041 if (s == NULL)
3042 {
3043 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3044 return FAIL;
3045 }
3046
3047 /* At top level, we expand the incoming string. At lower levels, it has already
3048 been expanded as part of condition processing. */
3049
3050 if (level == 0)
3051 {
3052 ss = expand_string(s);
3053 if (ss == NULL)
3054 {
3055 if (expand_string_forcedfail) return OK;
3056 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3057 expand_string_message);
3058 return ERROR;
3059 }
3060 }
3061 else ss = s;
3062
3063 while (isspace(*ss))ss++;
3064
3065 /* If we can't find a named ACL, the default is to parse it as an inline one.
3066 (Unless it begins with a slash; non-existent files give rise to an error.) */
3067
3068 acl_text = ss;
3069
3070 /* Handle the case of a string that does not contain any spaces. Look for a
3071 named ACL among those read from the configuration, or a previously read file.
3072 It is possible that the pointer to the ACL is NULL if the configuration
3073 contains a name with no data. If not found, and the text begins with '/',
3074 read an ACL from a file, and save it so it can be re-used. */
3075
3076 if (Ustrchr(ss, ' ') == NULL)
3077 {
3078 tree_node *t = tree_search(acl_anchor, ss);
3079 if (t != NULL)
3080 {
3081 acl = (acl_block *)(t->data.ptr);
3082 if (acl == NULL)
3083 {
3084 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3085 return FAIL;
3086 }
3087 acl_name = string_sprintf("ACL \"%s\"", ss);
3088 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3089 }
3090
3091 else if (*ss == '/')
3092 {
3093 struct stat statbuf;
3094 fd = Uopen(ss, O_RDONLY, 0);
3095 if (fd < 0)
3096 {
3097 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3098 strerror(errno));
3099 return ERROR;
3100 }
3101
3102 if (fstat(fd, &statbuf) != 0)
3103 {
3104 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3105 strerror(errno));
3106 return ERROR;
3107 }
3108
3109 acl_text = store_get(statbuf.st_size + 1);
3110 acl_text_end = acl_text + statbuf.st_size + 1;
3111
3112 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3113 {
3114 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3115 ss, strerror(errno));
3116 return ERROR;
3117 }
3118 acl_text[statbuf.st_size] = 0;
3119 close(fd);
3120
3121 acl_name = string_sprintf("ACL \"%s\"", ss);
3122 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3123 }
3124 }
3125
3126 /* Parse an ACL that is still in text form. If it came from a file, remember it
3127 in the ACL tree, having read it into the POOL_PERM store pool so that it
3128 persists between multiple messages. */
3129
3130 if (acl == NULL)
3131 {
3132 int old_pool = store_pool;
3133 if (fd >= 0) store_pool = POOL_PERM;
3134 acl = acl_read(acl_getline, log_msgptr);
3135 store_pool = old_pool;
3136 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3137 if (fd >= 0)
3138 {
3139 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3140 Ustrcpy(t->name, ss);
3141 t->data.ptr = acl;
3142 (void)tree_insertnode(&acl_anchor, t);
3143 }
3144 }
3145
3146 /* Now we have an ACL to use. It's possible it may be NULL. */
3147
3148 while (acl != NULL)
3149 {
3150 int cond;
3151 int basic_errno = 0;
3152 BOOL endpass_seen = FALSE;
3153
3154 *log_msgptr = *user_msgptr = NULL;
3155 acl_temp_details = FALSE;
3156
3157 if (where == ACL_WHERE_QUIT &&
3158 acl->verb != ACL_ACCEPT &&
3159 acl->verb != ACL_WARN)
3160 {
3161 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3162 verbs[acl->verb]);
3163 return ERROR;
3164 }
3165
3166 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3167
3168 /* Clear out any search error message from a previous check before testing
3169 this condition. */
3170
3171 search_error_message = NULL;
3172 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3173 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3174
3175 /* Handle special returns: DEFER causes a return except on a WARN verb;
3176 ERROR always causes a return. */
3177
3178 switch (cond)
3179 {
3180 case DEFER:
3181 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3182 if (basic_errno != ERRNO_CALLOUTDEFER)
3183 {
3184 if (search_error_message != NULL && *search_error_message != 0)
3185 *log_msgptr = search_error_message;
3186 if (smtp_return_error_details) acl_temp_details = TRUE;
3187 }
3188 else
3189 {
3190 acl_temp_details = TRUE;
3191 }
3192 if (acl->verb != ACL_WARN) return DEFER;
3193 break;
3194
3195 default: /* Paranoia */
3196 case ERROR:
3197 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3198 return ERROR;
3199
3200 case OK:
3201 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3202 verbs[acl->verb]);
3203 break;
3204
3205 case FAIL:
3206 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3207 break;
3208
3209 /* DISCARD and DROP can happen only from a nested ACL condition, and
3210 DISCARD can happen only for an "accept" or "discard" verb. */
3211
3212 case DISCARD:
3213 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3214 verbs[acl->verb]);
3215 break;
3216
3217 case FAIL_DROP:
3218 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3219 verbs[acl->verb]);
3220 break;
3221 }
3222
3223 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3224 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3225 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3226
3227 switch(acl->verb)
3228 {
3229 case ACL_ACCEPT:
3230 if (cond == OK || cond == DISCARD) return cond;
3231 if (endpass_seen)
3232 {
3233 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3234 return cond;
3235 }
3236 break;
3237
3238 case ACL_DEFER:
3239 if (cond == OK)
3240 {
3241 acl_temp_details = TRUE;
3242 return DEFER;
3243 }
3244 break;
3245
3246 case ACL_DENY:
3247 if (cond == OK) return FAIL;
3248 break;
3249
3250 case ACL_DISCARD:
3251 if (cond == OK || cond == DISCARD) return DISCARD;
3252 if (endpass_seen)
3253 {
3254 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3255 return cond;
3256 }
3257 break;
3258
3259 case ACL_DROP:
3260 if (cond == OK) return FAIL_DROP;
3261 break;
3262
3263 case ACL_REQUIRE:
3264 if (cond != OK) return cond;
3265 break;
3266
3267 case ACL_WARN:
3268 if (cond == OK)
3269 acl_warn(where, *user_msgptr, *log_msgptr);
3270 else if (cond == DEFER)
3271 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3272 "condition test deferred%s%s", host_and_ident(TRUE),
3273 (*log_msgptr == NULL)? US"" : US": ",
3274 (*log_msgptr == NULL)? US"" : *log_msgptr);
3275 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3276 break;
3277
3278 default:
3279 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3280 acl->verb);
3281 break;
3282 }
3283
3284 /* Pass to the next ACL item */
3285
3286 acl = acl->next;
3287 }
3288
3289 /* We have reached the end of the ACL. This is an implicit DENY. */
3290
3291 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3292 return FAIL;
3293 }
3294
3295
3296 /*************************************************
3297 * Check access using an ACL *
3298 *************************************************/
3299
3300 /* This is the external interface for ACL checks. It sets up an address and the
3301 expansions for $domain and $local_part when called after RCPT, then calls
3302 acl_check_internal() to do the actual work.
3303
3304 Arguments:
3305 where ACL_WHERE_xxxx indicating where called from
3306 data_string RCPT address, or SMTP command argument, or NULL
3307 s the input string; NULL is the same as an empty ACL => DENY
3308 user_msgptr where to put a user error (for SMTP response)
3309 log_msgptr where to put a logging message (not for SMTP response)
3310
3311 Returns: OK access is granted by an ACCEPT verb
3312 DISCARD access is granted by a DISCARD verb
3313 FAIL access is denied
3314 FAIL_DROP access is denied; drop the connection
3315 DEFER can't tell at the moment
3316 ERROR disaster
3317 */
3318
3319 int
3320 acl_check(int where, uschar *data_string, uschar *s, uschar **user_msgptr,
3321 uschar **log_msgptr)
3322 {
3323 int rc;
3324 address_item adb;
3325 address_item *addr;
3326
3327 *user_msgptr = *log_msgptr = NULL;
3328 sender_verified_failed = NULL;
3329
3330 if (where == ACL_WHERE_RCPT)
3331 {
3332 adb = address_defaults;
3333 addr = &adb;
3334 addr->address = data_string;
3335 if (deliver_split_address(addr) == DEFER)
3336 {
3337 *log_msgptr = US"defer in percent_hack_domains check";
3338 return DEFER;
3339 }
3340 deliver_domain = addr->domain;
3341 deliver_localpart = addr->local_part;
3342 }
3343 else
3344 {
3345 addr = NULL;
3346 smtp_command_argument = data_string;
3347 }
3348
3349 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3350
3351 smtp_command_argument = deliver_domain =
3352 deliver_localpart = deliver_address_data = sender_address_data = NULL;
3353
3354 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3355 ACL, which is really in the middle of an SMTP command. */
3356
3357 if (rc == DISCARD)
3358 {
3359 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3360 {
3361 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3362 "ACL", acl_wherenames[where]);
3363 return ERROR;
3364 }
3365 return DISCARD;
3366 }
3367
3368 /* A DROP response is not permitted from MAILAUTH */
3369
3370 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3371 {
3372 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3373 "ACL", acl_wherenames[where]);
3374 return ERROR;
3375 }
3376
3377 /* Before giving an error response, take a look at the length of any user
3378 message, and split it up into multiple lines if possible. */
3379
3380 if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75)
3381 {
3382 uschar *s = *user_msgptr = string_copy(*user_msgptr);
3383 uschar *ss = s;
3384
3385 for (;;)
3386 {
3387 int i = 0;
3388 while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++;
3389 if (*ss == 0) break;
3390 if (*ss == '\n')
3391 s = ++ss;
3392 else
3393 {
3394 uschar *t = ss + 1;
3395 uschar *tt = NULL;
3396 while (--t > s + 35)
3397 {
3398 if (*t == ' ')
3399 {
3400 if (t[-1] == ':') { tt = t; break; }
3401 if (tt == NULL) tt = t;
3402 }
3403 }
3404
3405 if (tt == NULL) /* Can't split behind - try ahead */
3406 {
3407 t = ss + 1;
3408 while (*t != 0)
3409 {
3410 if (*t == ' ' || *t == '\n')
3411 { tt = t; break; }
3412 t++;
3413 }
3414 }
3415
3416 if (tt == NULL) break; /* Can't find anywhere to split */
3417 *tt = '\n';
3418 s = ss = tt+1;
3419 }
3420 }
3421 }
3422
3423 return rc;
3424 }
3425
3426 /* End of acl.c */