A tweak to change PH/13, so that verify=helo never defers (as in 4.52).
[exim.git] / src / src / acl.c
1 /* $Cambridge: exim/src/src/acl.c,v 1.49 2005/09/22 12:02:22 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[] = {
85 US"acl",
86 US"authenticated",
87 #ifdef EXPERIMENTAL_BRIGHTMAIL
88 US"bmi_optin",
89 #endif
90 US"condition",
91 US"control",
92 #ifdef WITH_CONTENT_SCAN
93 US"decode",
94 #endif
95 US"delay",
96 #ifdef WITH_OLD_DEMIME
97 US"demime",
98 #endif
99 #ifdef EXPERIMENTAL_DOMAINKEYS
100 US"dk_domain_source",
101 US"dk_policy",
102 US"dk_sender_domains",
103 US"dk_sender_local_parts",
104 US"dk_senders",
105 US"dk_status",
106 #endif
107 US"dnslists", US"domains", US"encrypted",
108 US"endpass", US"hosts", US"local_parts", US"log_message", US"logwrite",
109 #ifdef WITH_CONTENT_SCAN
110 US"malware",
111 #endif
112 US"message",
113 #ifdef WITH_CONTENT_SCAN
114 US"mime_regex",
115 #endif
116 US"ratelimit",
117 US"recipients",
118 #ifdef WITH_CONTENT_SCAN
119 US"regex",
120 #endif
121 US"sender_domains", US"senders", US"set",
122 #ifdef WITH_CONTENT_SCAN
123 US"spam",
124 #endif
125 #ifdef EXPERIMENTAL_SPF
126 US"spf",
127 #endif
128 US"verify" };
129
130
131 /* Return values from decode_control(); keep in step with the table of names
132 that follows! */
133
134 enum {
135 #ifdef EXPERIMENTAL_BRIGHTMAIL
136 CONTROL_BMI_RUN,
137 #endif
138 #ifdef EXPERIMENTAL_DOMAINKEYS
139 CONTROL_DK_VERIFY,
140 #endif
141 CONTROL_ERROR, CONTROL_CASEFUL_LOCAL_PART, CONTROL_CASELOWER_LOCAL_PART,
142 CONTROL_ENFORCE_SYNC, CONTROL_NO_ENFORCE_SYNC, CONTROL_FREEZE,
143 CONTROL_QUEUE_ONLY, CONTROL_SUBMISSION, CONTROL_SUPPRESS_LOCAL_FIXUPS,
144 #ifdef WITH_CONTENT_SCAN
145 CONTROL_NO_MBOX_UNSPOOL,
146 #endif
147 CONTROL_FAKEDEFER, CONTROL_FAKEREJECT, CONTROL_NO_MULTILINE };
148
149 /* ACL control names; keep in step with the table above! This list is used for
150 turning ids into names. The actual list of recognized names is in the variable
151 control_def controls_list[] below. The fact that there are two lists is a mess
152 and should be tidied up. */
153
154 static uschar *controls[] = {
155 #ifdef EXPERIMENTAL_BRIGHTMAIL
156 US"bmi_run",
157 #endif
158 #ifdef EXPERIMENTAL_DOMAINKEYS
159 US"dk_verify",
160 #endif
161 US"error", US"caseful_local_part",
162 US"caselower_local_part", US"enforce_sync", US"no_enforce_sync", US"freeze",
163 US"queue_only", US"submission", US"suppress_local_fixups",
164 #ifdef WITH_CONTENT_SCAN
165 US"no_mbox_unspool",
166 #endif
167
168 US"no_multiline"};
169
170 /* Flags to indicate for which conditions /modifiers a string expansion is done
171 at the outer level. In the other cases, expansion already occurs in the
172 checking functions. */
173
174 static uschar cond_expand_at_top[] = {
175 TRUE, /* acl */
176 FALSE, /* authenticated */
177 #ifdef EXPERIMENTAL_BRIGHTMAIL
178 TRUE, /* bmi_optin */
179 #endif
180 TRUE, /* condition */
181 TRUE, /* control */
182 #ifdef WITH_CONTENT_SCAN
183 TRUE, /* decode */
184 #endif
185 TRUE, /* delay */
186 #ifdef WITH_OLD_DEMIME
187 TRUE, /* demime */
188 #endif
189 #ifdef EXPERIMENTAL_DOMAINKEYS
190 TRUE, /* dk_domain_source */
191 TRUE, /* dk_policy */
192 TRUE, /* dk_sender_domains */
193 TRUE, /* dk_sender_local_parts */
194 TRUE, /* dk_senders */
195 TRUE, /* dk_status */
196 #endif
197 TRUE, /* dnslists */
198 FALSE, /* domains */
199 FALSE, /* encrypted */
200 TRUE, /* endpass */
201 FALSE, /* hosts */
202 FALSE, /* local_parts */
203 TRUE, /* log_message */
204 TRUE, /* logwrite */
205 #ifdef WITH_CONTENT_SCAN
206 TRUE, /* malware */
207 #endif
208 TRUE, /* message */
209 #ifdef WITH_CONTENT_SCAN
210 TRUE, /* mime_regex */
211 #endif
212 TRUE, /* ratelimit */
213 FALSE, /* recipients */
214 #ifdef WITH_CONTENT_SCAN
215 TRUE, /* regex */
216 #endif
217 FALSE, /* sender_domains */
218 FALSE, /* senders */
219 TRUE, /* set */
220 #ifdef WITH_CONTENT_SCAN
221 TRUE, /* spam */
222 #endif
223 #ifdef EXPERIMENTAL_SPF
224 TRUE, /* spf */
225 #endif
226 TRUE /* verify */
227 };
228
229 /* Flags to identify the modifiers */
230
231 static uschar cond_modifiers[] = {
232 FALSE, /* acl */
233 FALSE, /* authenticated */
234 #ifdef EXPERIMENTAL_BRIGHTMAIL
235 TRUE, /* bmi_optin */
236 #endif
237 FALSE, /* condition */
238 TRUE, /* control */
239 #ifdef WITH_CONTENT_SCAN
240 FALSE, /* decode */
241 #endif
242 TRUE, /* delay */
243 #ifdef WITH_OLD_DEMIME
244 FALSE, /* demime */
245 #endif
246 #ifdef EXPERIMENTAL_DOMAINKEYS
247 FALSE, /* dk_domain_source */
248 FALSE, /* dk_policy */
249 FALSE, /* dk_sender_domains */
250 FALSE, /* dk_sender_local_parts */
251 FALSE, /* dk_senders */
252 FALSE, /* dk_status */
253 #endif
254 FALSE, /* dnslists */
255 FALSE, /* domains */
256 FALSE, /* encrypted */
257 TRUE, /* endpass */
258 FALSE, /* hosts */
259 FALSE, /* local_parts */
260 TRUE, /* log_message */
261 TRUE, /* logwrite */
262 #ifdef WITH_CONTENT_SCAN
263 FALSE, /* malware */
264 #endif
265 TRUE, /* message */
266 #ifdef WITH_CONTENT_SCAN
267 FALSE, /* mime_regex */
268 #endif
269 FALSE, /* ratelimit */
270 FALSE, /* recipients */
271 #ifdef WITH_CONTENT_SCAN
272 FALSE, /* regex */
273 #endif
274 FALSE, /* sender_domains */
275 FALSE, /* senders */
276 TRUE, /* set */
277 #ifdef WITH_CONTENT_SCAN
278 FALSE, /* spam */
279 #endif
280 #ifdef EXPERIMENTAL_SPF
281 FALSE, /* spf */
282 #endif
283 FALSE /* verify */
284 };
285
286 /* Bit map vector of which conditions are not allowed at certain times. For
287 each condition, there's a bitmap of dis-allowed times. For some, it is easier
288 to specify the negation of a small number of allowed times. */
289
290 static unsigned int cond_forbids[] = {
291 0, /* acl */
292
293 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_CONNECT)| /* authenticated */
294 (1<<ACL_WHERE_HELO),
295
296 #ifdef EXPERIMENTAL_BRIGHTMAIL
297 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
298 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
299 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
300 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
301 (1<<ACL_WHERE_MAILAUTH)|
302 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
303 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA),
304 #endif
305
306 0, /* condition */
307
308 /* Certain types of control are always allowed, so we let it through
309 always and check in the control processing itself. */
310
311 0, /* control */
312
313 #ifdef WITH_CONTENT_SCAN
314 (unsigned int)
315 ~(1<<ACL_WHERE_MIME), /* decode */
316 #endif
317
318 0, /* delay */
319
320 #ifdef WITH_OLD_DEMIME
321 (unsigned int)
322 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
323 #endif
324
325 #ifdef EXPERIMENTAL_DOMAINKEYS
326 (1<<ACL_WHERE_AUTH)| /* dk_domain_source */
327 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
328 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
329 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
330 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
331 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
332 (1<<ACL_WHERE_VRFY),
333
334 (1<<ACL_WHERE_AUTH)| /* dk_policy */
335 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
336 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
337 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
338 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
339 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
340 (1<<ACL_WHERE_VRFY),
341
342 (1<<ACL_WHERE_AUTH)| /* dk_sender_domains */
343 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
344 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
345 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
346 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
347 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
348 (1<<ACL_WHERE_VRFY),
349
350 (1<<ACL_WHERE_AUTH)| /* dk_sender_local_parts */
351 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
352 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
353 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
354 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
355 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
356 (1<<ACL_WHERE_VRFY),
357
358 (1<<ACL_WHERE_AUTH)| /* dk_senders */
359 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
360 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
361 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
362 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
363 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
364 (1<<ACL_WHERE_VRFY),
365
366 (1<<ACL_WHERE_AUTH)| /* dk_status */
367 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
368 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
369 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
370 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
371 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
372 (1<<ACL_WHERE_VRFY),
373 #endif
374
375 (1<<ACL_WHERE_NOTSMTP), /* dnslists */
376
377 (unsigned int)
378 ~(1<<ACL_WHERE_RCPT), /* domains */
379
380 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_CONNECT)| /* encrypted */
381 (1<<ACL_WHERE_HELO),
382
383 0, /* endpass */
384
385 (1<<ACL_WHERE_NOTSMTP), /* hosts */
386
387 (unsigned int)
388 ~(1<<ACL_WHERE_RCPT), /* local_parts */
389
390 0, /* log_message */
391
392 0, /* logwrite */
393
394 #ifdef WITH_CONTENT_SCAN
395 (unsigned int)
396 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
397 #endif
398
399 0, /* message */
400
401 #ifdef WITH_CONTENT_SCAN
402 (unsigned int)
403 ~(1<<ACL_WHERE_MIME), /* mime_regex */
404 #endif
405
406 0, /* ratelimit */
407
408 (unsigned int)
409 ~(1<<ACL_WHERE_RCPT), /* recipients */
410
411 #ifdef WITH_CONTENT_SCAN
412 (unsigned int)
413 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
414 (1<<ACL_WHERE_MIME)),
415 #endif
416
417 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
418 (1<<ACL_WHERE_HELO)|
419 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
420 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
421 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
422
423 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
424 (1<<ACL_WHERE_HELO)|
425 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
426 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
427 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
428
429 0, /* set */
430
431 #ifdef WITH_CONTENT_SCAN
432 (unsigned int)
433 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
434 #endif
435
436 #ifdef EXPERIMENTAL_SPF
437 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
438 (1<<ACL_WHERE_HELO)|
439 (1<<ACL_WHERE_MAILAUTH)|
440 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
441 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
442 #endif
443
444 /* Certain types of verify are always allowed, so we let it through
445 always and check in the verify function itself */
446
447 0 /* verify */
448 };
449
450
451 /* Bit map vector of which controls are not allowed at certain times. For
452 each control, there's a bitmap of dis-allowed times. For some, it is easier to
453 specify the negation of a small number of allowed times. */
454
455 static unsigned int control_forbids[] = {
456 #ifdef EXPERIMENTAL_BRIGHTMAIL
457 0, /* bmi_run */
458 #endif
459 #ifdef EXPERIMENTAL_DOMAINKEYS
460 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), /* dk_verify */
461 #endif
462
463 0, /* error */
464
465 (unsigned int)
466 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
467
468 (unsigned int)
469 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
470
471 (1<<ACL_WHERE_NOTSMTP), /* enforce_sync */
472
473 (1<<ACL_WHERE_NOTSMTP), /* no_enforce_sync */
474
475 (unsigned int)
476 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
477 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
478 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
479
480 (unsigned int)
481 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
482 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
483 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
484
485 (unsigned int)
486 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
487 (1<<ACL_WHERE_PREDATA)),
488
489 (unsigned int)
490 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
491 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_PREDATA)),
492
493 #ifdef WITH_CONTENT_SCAN
494 (unsigned int)
495 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
496 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
497 (1<<ACL_WHERE_MIME)),
498 #endif
499
500 (unsigned int)
501 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
502 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
503 (1<<ACL_WHERE_MIME)),
504
505 (unsigned int)
506 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
507 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
508 (1<<ACL_WHERE_MIME)),
509
510 (1<<ACL_WHERE_NOTSMTP) /* no_multiline */
511 };
512
513 /* Structure listing various control arguments, with their characteristics. */
514
515 typedef struct control_def {
516 uschar *name;
517 int value; /* CONTROL_xxx value */
518 BOOL has_option; /* Has /option(s) following */
519 } control_def;
520
521 static control_def controls_list[] = {
522 #ifdef EXPERIMENTAL_BRIGHTMAIL
523 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
524 #endif
525 #ifdef EXPERIMENTAL_DOMAINKEYS
526 { US"dk_verify", CONTROL_DK_VERIFY, FALSE },
527 #endif
528 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
529 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
530 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
531 { US"freeze", CONTROL_FREEZE, FALSE },
532 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
533 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
534 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
535 #ifdef WITH_CONTENT_SCAN
536 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
537 #endif
538 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
539 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
540 { US"submission", CONTROL_SUBMISSION, TRUE },
541 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE }
542 };
543
544 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
545 caches its result in a tree to avoid repeated DNS queries. The result is an
546 integer code which is used as an index into the following tables of
547 explanatory strings and verification return codes. */
548
549 static tree_node *csa_cache = NULL;
550
551 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
552 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
553
554 /* The acl_verify_csa() return code is translated into an acl_verify() return
555 code using the following table. It is OK unless the client is definitely not
556 authorized. This is because CSA is supposed to be optional for sending sites,
557 so recipients should not be too strict about checking it - especially because
558 DNS problems are quite likely to occur. It's possible to use $csa_status in
559 further ACL conditions to distinguish ok, unknown, and defer if required, but
560 the aim is to make the usual configuration simple. */
561
562 static int csa_return_code[] = {
563 OK, OK, OK, OK,
564 FAIL, FAIL, FAIL, FAIL
565 };
566
567 static uschar *csa_status_string[] = {
568 US"unknown", US"ok", US"defer", US"defer",
569 US"fail", US"fail", US"fail", US"fail"
570 };
571
572 static uschar *csa_reason_string[] = {
573 US"unknown",
574 US"ok",
575 US"deferred (SRV lookup failed)",
576 US"deferred (target address lookup failed)",
577 US"failed (explicit authorization required)",
578 US"failed (host name not authorized)",
579 US"failed (no authorized addresses)",
580 US"failed (client address mismatch)"
581 };
582
583 /* Enable recursion between acl_check_internal() and acl_check_condition() */
584
585 static int acl_check_internal(int, address_item *, uschar *, int, uschar **,
586 uschar **);
587
588
589 /*************************************************
590 * Pick out name from list *
591 *************************************************/
592
593 /* Use a binary chop method
594
595 Arguments:
596 name name to find
597 list list of names
598 end size of list
599
600 Returns: offset in list, or -1 if not found
601 */
602
603 static int
604 acl_checkname(uschar *name, uschar **list, int end)
605 {
606 int start = 0;
607
608 while (start < end)
609 {
610 int mid = (start + end)/2;
611 int c = Ustrcmp(name, list[mid]);
612 if (c == 0) return mid;
613 if (c < 0) end = mid; else start = mid + 1;
614 }
615
616 return -1;
617 }
618
619
620 /*************************************************
621 * Read and parse one ACL *
622 *************************************************/
623
624 /* This function is called both from readconf in order to parse the ACLs in the
625 configuration file, and also when an ACL is encountered dynamically (e.g. as
626 the result of an expansion). It is given a function to call in order to
627 retrieve the lines of the ACL. This function handles skipping comments and
628 blank lines (where relevant).
629
630 Arguments:
631 func function to get next line of ACL
632 error where to put an error message
633
634 Returns: pointer to ACL, or NULL
635 NULL can be legal (empty ACL); in this case error will be NULL
636 */
637
638 acl_block *
639 acl_read(uschar *(*func)(void), uschar **error)
640 {
641 acl_block *yield = NULL;
642 acl_block **lastp = &yield;
643 acl_block *this = NULL;
644 acl_condition_block *cond;
645 acl_condition_block **condp = NULL;
646 uschar *s;
647
648 *error = NULL;
649
650 while ((s = (*func)()) != NULL)
651 {
652 int v, c;
653 BOOL negated = FALSE;
654 uschar *saveline = s;
655 uschar name[64];
656
657 /* Conditions (but not verbs) are allowed to be negated by an initial
658 exclamation mark. */
659
660 while (isspace(*s)) s++;
661 if (*s == '!')
662 {
663 negated = TRUE;
664 s++;
665 }
666
667 /* Read the name of a verb or a condition, or the start of a new ACL, which
668 can be started by a name, or by a macro definition. */
669
670 s = readconf_readname(name, sizeof(name), s);
671 if (*s == ':' || isupper(name[0] && *s == '=')) return yield;
672
673 /* If a verb is unrecognized, it may be another condition or modifier that
674 continues the previous verb. */
675
676 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
677 if (v < 0)
678 {
679 if (this == NULL)
680 {
681 *error = string_sprintf("unknown ACL verb in \"%s\"", saveline);
682 return NULL;
683 }
684 }
685
686 /* New verb */
687
688 else
689 {
690 if (negated)
691 {
692 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
693 return NULL;
694 }
695 this = store_get(sizeof(acl_block));
696 *lastp = this;
697 lastp = &(this->next);
698 this->next = NULL;
699 this->verb = v;
700 this->condition = NULL;
701 condp = &(this->condition);
702 if (*s == 0) continue; /* No condition on this line */
703 if (*s == '!')
704 {
705 negated = TRUE;
706 s++;
707 }
708 s = readconf_readname(name, sizeof(name), s); /* Condition name */
709 }
710
711 /* Handle a condition or modifier. */
712
713 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
714 if (c < 0)
715 {
716 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
717 saveline);
718 return NULL;
719 }
720
721 /* The modifiers may not be negated */
722
723 if (negated && cond_modifiers[c])
724 {
725 *error = string_sprintf("ACL error: negation is not allowed with "
726 "\"%s\"", conditions[c]);
727 return NULL;
728 }
729
730 /* ENDPASS may occur only with ACCEPT or DISCARD. */
731
732 if (c == ACLC_ENDPASS &&
733 this->verb != ACL_ACCEPT &&
734 this->verb != ACL_DISCARD)
735 {
736 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
737 conditions[c], verbs[this->verb]);
738 return NULL;
739 }
740
741 cond = store_get(sizeof(acl_condition_block));
742 cond->next = NULL;
743 cond->type = c;
744 cond->u.negated = negated;
745
746 *condp = cond;
747 condp = &(cond->next);
748
749 /* The "set" modifier is different in that its argument is "name=value"
750 rather than just a value, and we can check the validity of the name, which
751 gives us a variable number to insert into the data block. */
752
753 if (c == ACLC_SET)
754 {
755 if (Ustrncmp(s, "acl_", 4) != 0 || (s[4] != 'c' && s[4] != 'm') ||
756 !isdigit(s[5]) || (!isspace(s[6]) && s[6] != '='))
757 {
758 *error = string_sprintf("unrecognized name after \"set\" in ACL "
759 "modifier \"set %s\"", s);
760 return NULL;
761 }
762
763 cond->u.varnumber = s[5] - '0';
764 if (s[4] == 'm') cond->u.varnumber += ACL_C_MAX;
765 s += 6;
766 while (isspace(*s)) s++;
767 }
768
769 /* For "set", we are now positioned for the data. For the others, only
770 "endpass" has no data */
771
772 if (c != ACLC_ENDPASS)
773 {
774 if (*s++ != '=')
775 {
776 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
777 cond_modifiers[c]? US"modifier" : US"condition");
778 return NULL;
779 }
780 while (isspace(*s)) s++;
781 cond->arg = string_copy(s);
782 }
783 }
784
785 return yield;
786 }
787
788
789
790 /*************************************************
791 * Handle warnings *
792 *************************************************/
793
794 /* This function is called when a WARN verb's conditions are true. It adds to
795 the message's headers, and/or writes information to the log. In each case, this
796 only happens once (per message for headers, per connection for log).
797
798 Arguments:
799 where ACL_WHERE_xxxx indicating which ACL this is
800 user_message message for adding to headers
801 log_message message for logging, if different
802
803 Returns: nothing
804 */
805
806 static void
807 acl_warn(int where, uschar *user_message, uschar *log_message)
808 {
809 int hlen;
810
811 if (log_message != NULL && log_message != user_message)
812 {
813 uschar *text;
814 string_item *logged;
815
816 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
817 string_printing(log_message));
818
819 /* If a sender verification has failed, and the log message is "sender verify
820 failed", add the failure message. */
821
822 if (sender_verified_failed != NULL &&
823 sender_verified_failed->message != NULL &&
824 strcmpic(log_message, US"sender verify failed") == 0)
825 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
826
827 /* Search previously logged warnings. They are kept in malloc
828 store so they can be freed at the start of a new message. */
829
830 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
831 if (Ustrcmp(logged->text, text) == 0) break;
832
833 if (logged == NULL)
834 {
835 int length = Ustrlen(text) + 1;
836 log_write(0, LOG_MAIN, "%s", text);
837 logged = store_malloc(sizeof(string_item) + length);
838 logged->text = (uschar *)logged + sizeof(string_item);
839 memcpy(logged->text, text, length);
840 logged->next = acl_warn_logged;
841 acl_warn_logged = logged;
842 }
843 }
844
845 /* If there's no user message, we are done. */
846
847 if (user_message == NULL) return;
848
849 /* If this isn't a message ACL, we can't do anything with a user message.
850 Log an error. */
851
852 if (where > ACL_WHERE_NOTSMTP)
853 {
854 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
855 "found in a non-message (%s) ACL: cannot specify header lines here: "
856 "message ignored", acl_wherenames[where]);
857 return;
858 }
859
860 /* Treat the user message as a sequence of one or more header lines. */
861
862 hlen = Ustrlen(user_message);
863 if (hlen > 0)
864 {
865 uschar *text, *p, *q;
866
867 /* Add a final newline if not present */
868
869 text = ((user_message)[hlen-1] == '\n')? user_message :
870 string_sprintf("%s\n", user_message);
871
872 /* Loop for multiple header lines, taking care about continuations */
873
874 for (p = q = text; *p != 0; )
875 {
876 uschar *s;
877 int newtype = htype_add_bot;
878 header_line **hptr = &acl_warn_headers;
879
880 /* Find next header line within the string */
881
882 for (;;)
883 {
884 q = Ustrchr(q, '\n');
885 if (*(++q) != ' ' && *q != '\t') break;
886 }
887
888 /* If the line starts with a colon, interpret the instruction for where to
889 add it. This temporarily sets up a new type. */
890
891 if (*p == ':')
892 {
893 if (strncmpic(p, US":after_received:", 16) == 0)
894 {
895 newtype = htype_add_rec;
896 p += 16;
897 }
898 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
899 {
900 newtype = htype_add_rfc;
901 p += 14;
902 }
903 else if (strncmpic(p, US":at_start:", 10) == 0)
904 {
905 newtype = htype_add_top;
906 p += 10;
907 }
908 else if (strncmpic(p, US":at_end:", 8) == 0)
909 {
910 newtype = htype_add_bot;
911 p += 8;
912 }
913 while (*p == ' ' || *p == '\t') p++;
914 }
915
916 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
917 to the front of it. */
918
919 for (s = p; s < q - 1; s++)
920 {
921 if (*s == ':' || !isgraph(*s)) break;
922 }
923
924 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p);
925 hlen = Ustrlen(s);
926
927 /* See if this line has already been added */
928
929 while (*hptr != NULL)
930 {
931 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
932 hptr = &((*hptr)->next);
933 }
934
935 /* Add if not previously present */
936
937 if (*hptr == NULL)
938 {
939 header_line *h = store_get(sizeof(header_line));
940 h->text = s;
941 h->next = NULL;
942 h->type = newtype;
943 h->slen = hlen;
944 *hptr = h;
945 hptr = &(h->next);
946 }
947
948 /* Advance for next header line within the string */
949
950 p = q;
951 }
952 }
953 }
954
955
956
957 /*************************************************
958 * Verify and check reverse DNS *
959 *************************************************/
960
961 /* Called from acl_verify() below. We look up the host name(s) of the client IP
962 address if this has not yet been done. The host_name_lookup() function checks
963 that one of these names resolves to an address list that contains the client IP
964 address, so we don't actually have to do the check here.
965
966 Arguments:
967 user_msgptr pointer for user message
968 log_msgptr pointer for log message
969
970 Returns: OK verification condition succeeded
971 FAIL verification failed
972 DEFER there was a problem verifying
973 */
974
975 static int
976 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
977 {
978 int rc;
979
980 user_msgptr = user_msgptr; /* stop compiler warning */
981
982 /* Previous success */
983
984 if (sender_host_name != NULL) return OK;
985
986 /* Previous failure */
987
988 if (host_lookup_failed)
989 {
990 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
991 return FAIL;
992 }
993
994 /* Need to do a lookup */
995
996 HDEBUG(D_acl)
997 debug_printf("looking up host name to force name/address consistency check\n");
998
999 if ((rc = host_name_lookup()) != OK)
1000 {
1001 *log_msgptr = (rc == DEFER)?
1002 US"host lookup deferred for reverse lookup check"
1003 :
1004 string_sprintf("host lookup failed for reverse lookup check%s",
1005 host_lookup_msg);
1006 return rc; /* DEFER or FAIL */
1007 }
1008
1009 host_build_sender_fullhost();
1010 return OK;
1011 }
1012
1013
1014
1015 /*************************************************
1016 * Check client IP address matches CSA target *
1017 *************************************************/
1018
1019 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1020 response for address records belonging to the CSA target hostname. The section
1021 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1022 If one of the addresses matches the client's IP address, then the client is
1023 authorized by CSA. If there are target IP addresses but none of them match
1024 then the client is using an unauthorized IP address. If there are no target IP
1025 addresses then the client cannot be using an authorized IP address. (This is
1026 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1027
1028 Arguments:
1029 dnsa the DNS answer block
1030 dnss a DNS scan block for us to use
1031 reset option specifing what portion to scan, as described above
1032 target the target hostname to use for matching RR names
1033
1034 Returns: CSA_OK successfully authorized
1035 CSA_FAIL_MISMATCH addresses found but none matched
1036 CSA_FAIL_NOADDR no target addresses found
1037 */
1038
1039 static int
1040 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1041 uschar *target)
1042 {
1043 dns_record *rr;
1044 dns_address *da;
1045
1046 BOOL target_found = FALSE;
1047
1048 for (rr = dns_next_rr(dnsa, dnss, reset);
1049 rr != NULL;
1050 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1051 {
1052 /* Check this is an address RR for the target hostname. */
1053
1054 if (rr->type != T_A
1055 #if HAVE_IPV6
1056 && rr->type != T_AAAA
1057 #ifdef SUPPORT_A6
1058 && rr->type != T_A6
1059 #endif
1060 #endif
1061 ) continue;
1062
1063 if (strcmpic(target, rr->name) != 0) continue;
1064
1065 target_found = TRUE;
1066
1067 /* Turn the target address RR into a list of textual IP addresses and scan
1068 the list. There may be more than one if it is an A6 RR. */
1069
1070 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1071 {
1072 /* If the client IP address matches the target IP address, it's good! */
1073
1074 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1075
1076 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1077 }
1078 }
1079
1080 /* If we found some target addresses but none of them matched, the client is
1081 using an unauthorized IP address, otherwise the target has no authorized IP
1082 addresses. */
1083
1084 if (target_found) return CSA_FAIL_MISMATCH;
1085 else return CSA_FAIL_NOADDR;
1086 }
1087
1088
1089
1090 /*************************************************
1091 * Verify Client SMTP Authorization *
1092 *************************************************/
1093
1094 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1095 to find the CSA SRV record corresponding to the domain argument, or
1096 $sender_helo_name if no argument is provided. It then checks that the
1097 client is authorized, and that its IP address corresponds to the SRV
1098 target's address by calling acl_verify_csa_address() above. The address
1099 should have been returned in the DNS response's ADDITIONAL section, but if
1100 not we perform another DNS lookup to get it.
1101
1102 Arguments:
1103 domain pointer to optional parameter following verify = csa
1104
1105 Returns: CSA_UNKNOWN no valid CSA record found
1106 CSA_OK successfully authorized
1107 CSA_FAIL_* client is definitely not authorized
1108 CSA_DEFER_* there was a DNS problem
1109 */
1110
1111 static int
1112 acl_verify_csa(uschar *domain)
1113 {
1114 tree_node *t;
1115 uschar *found, *p;
1116 int priority, weight, port;
1117 dns_answer dnsa;
1118 dns_scan dnss;
1119 dns_record *rr;
1120 int rc, type;
1121 uschar target[256];
1122
1123 /* Work out the domain we are using for the CSA lookup. The default is the
1124 client's HELO domain. If the client has not said HELO, use its IP address
1125 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1126
1127 while (isspace(*domain) && *domain != '\0') ++domain;
1128 if (*domain == '\0') domain = sender_helo_name;
1129 if (domain == NULL) domain = sender_host_address;
1130 if (sender_host_address == NULL) return CSA_UNKNOWN;
1131
1132 /* If we have an address literal, strip off the framing ready for turning it
1133 into a domain. The framing consists of matched square brackets possibly
1134 containing a keyword and a colon before the actual IP address. */
1135
1136 if (domain[0] == '[')
1137 {
1138 uschar *start = Ustrchr(domain, ':');
1139 if (start == NULL) start = domain;
1140 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1141 }
1142
1143 /* Turn domains that look like bare IP addresses into domains in the reverse
1144 DNS. This code also deals with address literals and $sender_host_address. It's
1145 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1146 address literals, but it's probably the most friendly thing to do. This is an
1147 extension to CSA, so we allow it to be turned off for proper conformance. */
1148
1149 if (string_is_ip_address(domain, NULL))
1150 {
1151 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1152 dns_build_reverse(domain, target);
1153 domain = target;
1154 }
1155
1156 /* Find out if we've already done the CSA check for this domain. If we have,
1157 return the same result again. Otherwise build a new cached result structure
1158 for this domain. The name is filled in now, and the value is filled in when
1159 we return from this function. */
1160
1161 t = tree_search(csa_cache, domain);
1162 if (t != NULL) return t->data.val;
1163
1164 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1165 Ustrcpy(t->name, domain);
1166 (void)tree_insertnode(&csa_cache, t);
1167
1168 /* Now we are ready to do the actual DNS lookup(s). */
1169
1170 found = domain;
1171 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1172 {
1173 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1174
1175 default:
1176 return t->data.val = CSA_DEFER_SRV;
1177
1178 /* If we found nothing, the client's authorization is unknown. */
1179
1180 case DNS_NOMATCH:
1181 case DNS_NODATA:
1182 return t->data.val = CSA_UNKNOWN;
1183
1184 /* We got something! Go on to look at the reply in more detail. */
1185
1186 case DNS_SUCCEED:
1187 break;
1188 }
1189
1190 /* Scan the reply for well-formed CSA SRV records. */
1191
1192 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1193 rr != NULL;
1194 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1195 {
1196 if (rr->type != T_SRV) continue;
1197
1198 /* Extract the numerical SRV fields (p is incremented) */
1199
1200 p = rr->data;
1201 GETSHORT(priority, p);
1202 GETSHORT(weight, p);
1203 GETSHORT(port, p);
1204
1205 DEBUG(D_acl)
1206 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1207
1208 /* Check the CSA version number */
1209
1210 if (priority != 1) continue;
1211
1212 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1213 found by dns_special_lookup() is a parent of the one we asked for), we check
1214 the subdomain assertions in the port field. At the moment there's only one
1215 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1216 SRV records of their own. */
1217
1218 if (found != domain)
1219 {
1220 if (port & 1)
1221 return t->data.val = CSA_FAIL_EXPLICIT;
1222 else
1223 return t->data.val = CSA_UNKNOWN;
1224 }
1225
1226 /* This CSA SRV record refers directly to our domain, so we check the value
1227 in the weight field to work out the domain's authorization. 0 and 1 are
1228 unauthorized; 3 means the client is authorized but we can't check the IP
1229 address in order to authenticate it, so we treat it as unknown; values
1230 greater than 3 are undefined. */
1231
1232 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1233
1234 if (weight > 2) continue;
1235
1236 /* Weight == 2, which means the domain is authorized. We must check that the
1237 client's IP address is listed as one of the SRV target addresses. Save the
1238 target hostname then break to scan the additional data for its addresses. */
1239
1240 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1241 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1242
1243 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1244
1245 break;
1246 }
1247
1248 /* If we didn't break the loop then no appropriate records were found. */
1249
1250 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1251
1252 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1253 A target of "." indicates there are no valid addresses, so the client cannot
1254 be authorized. (This is an odd configuration because weight=2 target=. is
1255 equivalent to weight=1, but we check for it in order to keep load off the
1256 root name servers.) Note that dn_expand() turns "." into "". */
1257
1258 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1259
1260 /* Scan the additional section of the CSA SRV reply for addresses belonging
1261 to the target. If the name server didn't return any additional data (e.g.
1262 because it does not fully support SRV records), we need to do another lookup
1263 to obtain the target addresses; otherwise we have a definitive result. */
1264
1265 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1266 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1267
1268 /* The DNS lookup type corresponds to the IP version used by the client. */
1269
1270 #if HAVE_IPV6
1271 if (Ustrchr(sender_host_address, ':') != NULL)
1272 type = T_AAAA;
1273 else
1274 #endif /* HAVE_IPV6 */
1275 type = T_A;
1276
1277
1278 #if HAVE_IPV6 && defined(SUPPORT_A6)
1279 DNS_LOOKUP_AGAIN:
1280 #endif
1281
1282 switch (dns_lookup(&dnsa, target, type, NULL))
1283 {
1284 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1285
1286 default:
1287 return t->data.val = CSA_DEFER_ADDR;
1288
1289 /* If the query succeeded, scan the addresses and return the result. */
1290
1291 case DNS_SUCCEED:
1292 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1293 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1294 /* else fall through */
1295
1296 /* If the target has no IP addresses, the client cannot have an authorized
1297 IP address. However, if the target site uses A6 records (not AAAA records)
1298 we have to do yet another lookup in order to check them. */
1299
1300 case DNS_NOMATCH:
1301 case DNS_NODATA:
1302
1303 #if HAVE_IPV6 && defined(SUPPORT_A6)
1304 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1305 #endif
1306
1307 return t->data.val = CSA_FAIL_NOADDR;
1308 }
1309 }
1310
1311
1312
1313 /*************************************************
1314 * Handle verification (address & other) *
1315 *************************************************/
1316
1317 /* This function implements the "verify" condition. It is called when
1318 encountered in any ACL, because some tests are almost always permitted. Some
1319 just don't make sense, and always fail (for example, an attempt to test a host
1320 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1321
1322 Arguments:
1323 where where called from
1324 addr the recipient address that the ACL is handling, or NULL
1325 arg the argument of "verify"
1326 user_msgptr pointer for user message
1327 log_msgptr pointer for log message
1328 basic_errno where to put verify errno
1329
1330 Returns: OK verification condition succeeded
1331 FAIL verification failed
1332 DEFER there was a problem verifying
1333 ERROR syntax error
1334 */
1335
1336 static int
1337 acl_verify(int where, address_item *addr, uschar *arg,
1338 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1339 {
1340 int sep = '/';
1341 int callout = -1;
1342 int callout_overall = -1;
1343 int callout_connect = -1;
1344 int verify_options = 0;
1345 int rc;
1346 BOOL verify_header_sender = FALSE;
1347 BOOL defer_ok = FALSE;
1348 BOOL callout_defer_ok = FALSE;
1349 BOOL no_details = FALSE;
1350 BOOL success_on_redirect = FALSE;
1351 address_item *sender_vaddr = NULL;
1352 uschar *verify_sender_address = NULL;
1353 uschar *pm_mailfrom = NULL;
1354 uschar *se_mailfrom = NULL;
1355
1356 /* Some of the verify items have slash-separated options; some do not. Diagnose
1357 an error if options are given for items that don't expect them. This code has
1358 now got very message. Refactoring to use a table would be a good idea one day.
1359 */
1360
1361 uschar *slash = Ustrchr(arg, '/');
1362 uschar *list = arg;
1363 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1364
1365 if (ss == NULL) goto BAD_VERIFY;
1366
1367 /* Handle name/address consistency verification in a separate function. */
1368
1369 if (strcmpic(ss, US"reverse_host_lookup") == 0)
1370 {
1371 if (slash != NULL) goto NO_OPTIONS;
1372 if (sender_host_address == NULL) return OK;
1373 return acl_verify_reverse(user_msgptr, log_msgptr);
1374 }
1375
1376 /* TLS certificate verification is done at STARTTLS time; here we just
1377 test whether it was successful or not. (This is for optional verification; for
1378 mandatory verification, the connection doesn't last this long.) */
1379
1380 if (strcmpic(ss, US"certificate") == 0)
1381 {
1382 if (slash != NULL) goto NO_OPTIONS;
1383 if (tls_certificate_verified) return OK;
1384 *user_msgptr = US"no verified certificate";
1385 return FAIL;
1386 }
1387
1388 /* We can test the result of optional HELO verification that might have
1389 occurred earlier. If not, we can attempt the verification now. */
1390
1391 if (strcmpic(ss, US"helo") == 0)
1392 {
1393 if (slash != NULL) goto NO_OPTIONS;
1394 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1395 return helo_verified? OK : FAIL;
1396 }
1397
1398 /* Do Client SMTP Authorization checks in a separate function, and turn the
1399 result code into user-friendly strings. */
1400
1401 if (strcmpic(ss, US"csa") == 0)
1402 {
1403 rc = acl_verify_csa(list);
1404 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1405 csa_reason_string[rc]);
1406 csa_status = csa_status_string[rc];
1407 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1408 return csa_return_code[rc];
1409 }
1410
1411 /* Check that all relevant header lines have the correct syntax. If there is
1412 a syntax error, we return details of the error to the sender if configured to
1413 send out full details. (But a "message" setting on the ACL can override, as
1414 always). */
1415
1416 if (strcmpic(ss, US"header_syntax") == 0)
1417 {
1418 if (slash != NULL) goto NO_OPTIONS;
1419 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1420 rc = verify_check_headers(log_msgptr);
1421 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1422 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1423 return rc;
1424 }
1425
1426 /* Check that no recipient of this message is "blind", that is, every envelope
1427 recipient must be mentioned in either To: or Cc:. */
1428
1429 if (strcmpic(ss, US"not_blind") == 0)
1430 {
1431 if (slash != NULL) goto NO_OPTIONS;
1432 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1433 rc = verify_check_notblind();
1434 if (rc != OK)
1435 {
1436 *log_msgptr = string_sprintf("bcc recipient detected");
1437 if (smtp_return_error_details)
1438 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1439 }
1440 return rc;
1441 }
1442
1443 /* The remaining verification tests check recipient and sender addresses,
1444 either from the envelope or from the header. There are a number of
1445 slash-separated options that are common to all of them. */
1446
1447
1448 /* Check that there is at least one verifiable sender address in the relevant
1449 header lines. This can be followed by callout and defer options, just like
1450 sender and recipient. */
1451
1452 if (strcmpic(ss, US"header_sender") == 0)
1453 {
1454 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1455 verify_header_sender = TRUE;
1456 }
1457
1458 /* Otherwise, first item in verify argument must be "sender" or "recipient".
1459 In the case of a sender, this can optionally be followed by an address to use
1460 in place of the actual sender (rare special-case requirement). */
1461
1462 else if (strncmpic(ss, US"sender", 6) == 0)
1463 {
1464 uschar *s = ss + 6;
1465 if (where > ACL_WHERE_NOTSMTP)
1466 {
1467 *log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
1468 "(only possible for MAIL, RCPT, PREDATA, or DATA)",
1469 acl_wherenames[where]);
1470 return ERROR;
1471 }
1472 if (*s == 0)
1473 verify_sender_address = sender_address;
1474 else
1475 {
1476 while (isspace(*s)) s++;
1477 if (*s++ != '=') goto BAD_VERIFY;
1478 while (isspace(*s)) s++;
1479 verify_sender_address = string_copy(s);
1480 }
1481 }
1482 else
1483 {
1484 if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
1485 if (addr == NULL)
1486 {
1487 *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
1488 "(only possible for RCPT)", acl_wherenames[where]);
1489 return ERROR;
1490 }
1491 }
1492
1493 /* Remaining items are optional; they apply to sender and recipient
1494 verification, including "header sender" verification. */
1495
1496 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1497 != NULL)
1498 {
1499 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1500 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1501 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1502
1503 /* These two old options are left for backwards compatibility */
1504
1505 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1506 {
1507 callout_defer_ok = TRUE;
1508 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1509 }
1510
1511 else if (strcmpic(ss, US"check_postmaster") == 0)
1512 {
1513 pm_mailfrom = US"";
1514 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1515 }
1516
1517 /* The callout option has a number of sub-options, comma separated */
1518
1519 else if (strncmpic(ss, US"callout", 7) == 0)
1520 {
1521 callout = CALLOUT_TIMEOUT_DEFAULT;
1522 ss += 7;
1523 if (*ss != 0)
1524 {
1525 while (isspace(*ss)) ss++;
1526 if (*ss++ == '=')
1527 {
1528 int optsep = ',';
1529 uschar *opt;
1530 uschar buffer[256];
1531 while (isspace(*ss)) ss++;
1532
1533 /* This callout option handling code has become a mess as new options
1534 have been added in an ad hoc manner. It should be tidied up into some
1535 kind of table-driven thing. */
1536
1537 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1538 != NULL)
1539 {
1540 if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
1541 else if (strcmpic(opt, US"no_cache") == 0)
1542 verify_options |= vopt_callout_no_cache;
1543 else if (strcmpic(opt, US"random") == 0)
1544 verify_options |= vopt_callout_random;
1545 else if (strcmpic(opt, US"use_sender") == 0)
1546 verify_options |= vopt_callout_recipsender;
1547 else if (strcmpic(opt, US"use_postmaster") == 0)
1548 verify_options |= vopt_callout_recippmaster;
1549 else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
1550 else if (strcmpic(opt, US"fullpostmaster") == 0)
1551 {
1552 pm_mailfrom = US"";
1553 verify_options |= vopt_callout_fullpm;
1554 }
1555
1556 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1557 {
1558 if (!verify_header_sender)
1559 {
1560 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1561 "callout option only for verify=header_sender (detected in ACL "
1562 "condition \"%s\")", arg);
1563 return ERROR;
1564 }
1565 opt += 8;
1566 while (isspace(*opt)) opt++;
1567 if (*opt++ != '=')
1568 {
1569 *log_msgptr = string_sprintf("'=' expected after "
1570 "\"mailfrom\" in ACL condition \"%s\"", arg);
1571 return ERROR;
1572 }
1573 while (isspace(*opt)) opt++;
1574 se_mailfrom = string_copy(opt);
1575 }
1576
1577 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1578 {
1579 opt += 19;
1580 while (isspace(*opt)) opt++;
1581 if (*opt++ != '=')
1582 {
1583 *log_msgptr = string_sprintf("'=' expected after "
1584 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1585 return ERROR;
1586 }
1587 while (isspace(*opt)) opt++;
1588 pm_mailfrom = string_copy(opt);
1589 }
1590
1591 else if (strncmpic(opt, US"maxwait", 7) == 0)
1592 {
1593 opt += 7;
1594 while (isspace(*opt)) opt++;
1595 if (*opt++ != '=')
1596 {
1597 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1598 "ACL condition \"%s\"", arg);
1599 return ERROR;
1600 }
1601 while (isspace(*opt)) opt++;
1602 callout_overall = readconf_readtime(opt, 0, FALSE);
1603 if (callout_overall < 0)
1604 {
1605 *log_msgptr = string_sprintf("bad time value in ACL condition "
1606 "\"verify %s\"", arg);
1607 return ERROR;
1608 }
1609 }
1610 else if (strncmpic(opt, US"connect", 7) == 0)
1611 {
1612 opt += 7;
1613 while (isspace(*opt)) opt++;
1614 if (*opt++ != '=')
1615 {
1616 *log_msgptr = string_sprintf("'=' expected after "
1617 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1618 return ERROR;
1619 }
1620 while (isspace(*opt)) opt++;
1621 callout_connect = readconf_readtime(opt, 0, FALSE);
1622 if (callout_connect < 0)
1623 {
1624 *log_msgptr = string_sprintf("bad time value in ACL condition "
1625 "\"verify %s\"", arg);
1626 return ERROR;
1627 }
1628 }
1629 else /* Plain time is callout connect/command timeout */
1630 {
1631 callout = readconf_readtime(opt, 0, FALSE);
1632 if (callout < 0)
1633 {
1634 *log_msgptr = string_sprintf("bad time value in ACL condition "
1635 "\"verify %s\"", arg);
1636 return ERROR;
1637 }
1638 }
1639 }
1640 }
1641 else
1642 {
1643 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1644 "ACL condition \"%s\"", arg);
1645 return ERROR;
1646 }
1647 }
1648 }
1649
1650 /* Option not recognized */
1651
1652 else
1653 {
1654 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1655 "condition \"verify %s\"", ss, arg);
1656 return ERROR;
1657 }
1658 }
1659
1660 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1661 (vopt_callout_recipsender|vopt_callout_recippmaster))
1662 {
1663 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1664 "for a recipient callout";
1665 return ERROR;
1666 }
1667
1668 /* Handle sender-in-header verification. Default the user message to the log
1669 message if giving out verification details. */
1670
1671 if (verify_header_sender)
1672 {
1673 int verrno;
1674 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1675 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1676 &verrno);
1677 if (rc != OK)
1678 {
1679 *basic_errno = verrno;
1680 if (smtp_return_error_details)
1681 {
1682 if (*user_msgptr == NULL && *log_msgptr != NULL)
1683 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1684 if (rc == DEFER) acl_temp_details = TRUE;
1685 }
1686 }
1687 }
1688
1689 /* Handle a sender address. The default is to verify *the* sender address, but
1690 optionally a different address can be given, for special requirements. If the
1691 address is empty, we are dealing with a bounce message that has no sender, so
1692 we cannot do any checking. If the real sender address gets rewritten during
1693 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1694 during message reception.
1695
1696 A list of verified "sender" addresses is kept to try to avoid doing to much
1697 work repetitively when there are multiple recipients in a message and they all
1698 require sender verification. However, when callouts are involved, it gets too
1699 complicated because different recipients may require different callout options.
1700 Therefore, we always do a full sender verify when any kind of callout is
1701 specified. Caching elsewhere, for instance in the DNS resolver and in the
1702 callout handling, should ensure that this is not terribly inefficient. */
1703
1704 else if (verify_sender_address != NULL)
1705 {
1706 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1707 != 0)
1708 {
1709 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1710 "sender verify callout";
1711 return ERROR;
1712 }
1713
1714 sender_vaddr = verify_checked_sender(verify_sender_address);
1715 if (sender_vaddr != NULL && /* Previously checked */
1716 callout <= 0) /* No callout needed this time */
1717 {
1718 /* If the "routed" flag is set, it means that routing worked before, so
1719 this check can give OK (the saved return code value, if set, belongs to a
1720 callout that was done previously). If the "routed" flag is not set, routing
1721 must have failed, so we use the saved return code. */
1722
1723 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1724 {
1725 rc = sender_vaddr->special_action;
1726 *basic_errno = sender_vaddr->basic_errno;
1727 }
1728 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1729 }
1730
1731 /* Do a new verification, and cache the result. The cache is used to avoid
1732 verifying the sender multiple times for multiple RCPTs when callouts are not
1733 specified (see comments above).
1734
1735 The cache is also used on failure to give details in response to the first
1736 RCPT that gets bounced for this reason. However, this can be suppressed by
1737 the no_details option, which sets the flag that says "this detail has already
1738 been sent". The cache normally contains just one address, but there may be
1739 more in esoteric circumstances. */
1740
1741 else
1742 {
1743 BOOL routed = TRUE;
1744 uschar *save_address_data = deliver_address_data;
1745
1746 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1747 if (no_details) setflag(sender_vaddr, af_sverify_told);
1748 if (verify_sender_address[0] != 0)
1749 {
1750 /* If this is the real sender address, save the unrewritten version
1751 for use later in receive. Otherwise, set a flag so that rewriting the
1752 sender in verify_address() does not update sender_address. */
1753
1754 if (verify_sender_address == sender_address)
1755 sender_address_unrewritten = sender_address;
1756 else
1757 verify_options |= vopt_fake_sender;
1758
1759 if (success_on_redirect)
1760 verify_options |= vopt_success_on_redirect;
1761
1762 /* The recipient, qualify, and expn options are never set in
1763 verify_options. */
1764
1765 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1766 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1767
1768 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1769
1770 if (rc == OK)
1771 {
1772 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1773 {
1774 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1775 verify_sender_address, sender_vaddr->address);
1776 }
1777 else
1778 {
1779 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1780 verify_sender_address);
1781 }
1782 }
1783 else *basic_errno = sender_vaddr->basic_errno;
1784 }
1785 else rc = OK; /* Null sender */
1786
1787 /* Cache the result code */
1788
1789 if (routed) setflag(sender_vaddr, af_verify_routed);
1790 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1791 sender_vaddr->special_action = rc;
1792 sender_vaddr->next = sender_verified_list;
1793 sender_verified_list = sender_vaddr;
1794
1795 /* Restore the recipient address data, which might have been clobbered by
1796 the sender verification. */
1797
1798 deliver_address_data = save_address_data;
1799 }
1800
1801 /* Put the sender address_data value into $sender_address_data */
1802
1803 sender_address_data = sender_vaddr->p.address_data;
1804 }
1805
1806 /* A recipient address just gets a straightforward verify; again we must handle
1807 the DEFER overrides. */
1808
1809 else
1810 {
1811 address_item addr2;
1812
1813 if (success_on_redirect)
1814 verify_options |= vopt_success_on_redirect;
1815
1816 /* We must use a copy of the address for verification, because it might
1817 get rewritten. */
1818
1819 addr2 = *addr;
1820 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1821 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1822 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1823
1824 *log_msgptr = addr2.message;
1825 *user_msgptr = (addr2.user_message != NULL)?
1826 addr2.user_message : addr2.message;
1827 *basic_errno = addr2.basic_errno;
1828
1829 /* Make $address_data visible */
1830 deliver_address_data = addr2.p.address_data;
1831 }
1832
1833 /* We have a result from the relevant test. Handle defer overrides first. */
1834
1835 if (rc == DEFER && (defer_ok ||
1836 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1837 {
1838 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1839 defer_ok? "defer_ok" : "callout_defer_ok");
1840 rc = OK;
1841 }
1842
1843 /* If we've failed a sender, set up a recipient message, and point
1844 sender_verified_failed to the address item that actually failed. */
1845
1846 if (rc != OK && verify_sender_address != NULL)
1847 {
1848 if (rc != DEFER)
1849 {
1850 *log_msgptr = *user_msgptr = US"Sender verify failed";
1851 }
1852 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1853 {
1854 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1855 }
1856 else
1857 {
1858 *log_msgptr = US"Could not complete sender verify callout";
1859 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
1860 *log_msgptr;
1861 }
1862
1863 sender_verified_failed = sender_vaddr;
1864 }
1865
1866 /* Verifying an address messes up the values of $domain and $local_part,
1867 so reset them before returning if this is a RCPT ACL. */
1868
1869 if (addr != NULL)
1870 {
1871 deliver_domain = addr->domain;
1872 deliver_localpart = addr->local_part;
1873 }
1874 return rc;
1875
1876 /* Syntax errors in the verify argument come here. */
1877
1878 BAD_VERIFY:
1879 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
1880 "\"helo\", \"header_syntax\", \"header_sender\" or "
1881 "\"reverse_host_lookup\" at start of ACL condition "
1882 "\"verify %s\"", arg);
1883 return ERROR;
1884
1885 /* Options supplied when not allowed come here */
1886
1887 NO_OPTIONS:
1888 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1889 "(this verify item has no options)", arg);
1890 return ERROR;
1891
1892 /* Calls in the wrong ACL come here */
1893
1894 WRONG_ACL:
1895 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1896 "(only possible in ACL for DATA)", acl_wherenames[where]);
1897 return ERROR;
1898 }
1899
1900
1901
1902
1903 /*************************************************
1904 * Check argument for control= modifier *
1905 *************************************************/
1906
1907 /* Called from acl_check_condition() below
1908
1909 Arguments:
1910 arg the argument string for control=
1911 pptr set to point to the terminating character
1912 where which ACL we are in
1913 log_msgptr for error messages
1914
1915 Returns: CONTROL_xxx value
1916 */
1917
1918 static int
1919 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
1920 {
1921 int len;
1922 control_def *d;
1923
1924 for (d = controls_list;
1925 d < controls_list + sizeof(controls_list)/sizeof(control_def);
1926 d++)
1927 {
1928 len = Ustrlen(d->name);
1929 if (Ustrncmp(d->name, arg, len) == 0) break;
1930 }
1931
1932 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
1933 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
1934 {
1935 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
1936 return CONTROL_ERROR;
1937 }
1938
1939 *pptr = arg + len;
1940 return d->value;
1941 }
1942
1943
1944
1945 /*************************************************
1946 * Handle rate limiting *
1947 *************************************************/
1948
1949 /* Called by acl_check_condition() below to calculate the result
1950 of the ACL ratelimit condition.
1951
1952 Note that the return value might be slightly unexpected: if the
1953 sender's rate is above the limit then the result is OK. This is
1954 similar to the dnslists condition, and is so that you can write
1955 ACL clauses like: defer ratelimit = 15 / 1h
1956
1957 Arguments:
1958 arg the option string for ratelimit=
1959 log_msgptr for error messages
1960
1961 Returns: OK - Sender's rate is above limit
1962 FAIL - Sender's rate is below limit
1963 DEFER - Problem opening ratelimit database
1964 ERROR - Syntax error in options.
1965 */
1966
1967 static int
1968 acl_ratelimit(uschar *arg, uschar **log_msgptr)
1969 {
1970 double limit, period;
1971 uschar *ss, *key;
1972 int sep = '/';
1973 BOOL have_key = FALSE, leaky = FALSE, strict = FALSE;
1974 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
1975 int old_pool, rc;
1976 tree_node **anchor, *t;
1977 open_db dbblock, *dbm;
1978 dbdata_ratelimit *dbd;
1979 struct timeval tv;
1980
1981 /* Parse the first two options and record their values in expansion
1982 variables. These variables allow the configuration to have informative
1983 error messages based on rate limits obtained from a table lookup. */
1984
1985 /* First is the maximum number of messages per period and maximum burst
1986 size, which must be greater than or equal to zero. Zero is useful for
1987 rate measurement as opposed to rate limiting. */
1988
1989 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
1990 if (sender_rate_limit == NULL)
1991 limit = -1.0;
1992 else
1993 {
1994 limit = Ustrtod(sender_rate_limit, &ss);
1995 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
1996 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
1997 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
1998 }
1999 if (limit < 0.0 || *ss != 0)
2000 {
2001 *log_msgptr = string_sprintf("syntax error in argument for "
2002 "\"ratelimit\" condition: \"%s\" is not a positive number",
2003 sender_rate_limit);
2004 return ERROR;
2005 }
2006
2007 /* We use the rest of the argument list following the limit as the
2008 lookup key, because it doesn't make sense to use the same stored data
2009 if the period or options are different. */
2010
2011 key = arg;
2012
2013 /* Second is the rate measurement period and exponential smoothing time
2014 constant. This must be strictly greater than zero, because zero leads to
2015 run-time division errors. */
2016
2017 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2018 if (sender_rate_period == NULL) period = -1.0;
2019 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2020 if (period <= 0.0)
2021 {
2022 *log_msgptr = string_sprintf("syntax error in argument for "
2023 "\"ratelimit\" condition: \"%s\" is not a time value",
2024 sender_rate_period);
2025 return ERROR;
2026 }
2027
2028 /* Parse the other options. Should we check if the per_* options are being
2029 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
2030
2031 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2032 != NULL)
2033 {
2034 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2035 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2036 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
2037 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
2038 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
2039 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
2040 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
2041 else have_key = TRUE;
2042 }
2043 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
2044 {
2045 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
2046 return ERROR;
2047 }
2048
2049 /* Default option values */
2050 if (!strict) leaky = TRUE;
2051 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
2052
2053 /* If there is no explicit key, use the sender_host_address. If there is no
2054 sender_host_address (e.g. -bs or acl_not_smtp) then we simply omit it. */
2055
2056 if (!have_key && sender_host_address != NULL)
2057 key = string_sprintf("%s / %s", key, sender_host_address);
2058
2059 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2060 limit, period, key);
2061
2062 /* See if we have already computed the rate by looking in the relevant tree. For
2063 per-connection rate limiting, store tree nodes and dbdata in the permanent pool
2064 so that they survive across resets. */
2065
2066 anchor = NULL;
2067 old_pool = store_pool;
2068
2069 if (per_conn)
2070 {
2071 anchor = &ratelimiters_conn;
2072 store_pool = POOL_PERM;
2073 }
2074 else if (per_mail || per_byte)
2075 anchor = &ratelimiters_mail;
2076 else if (per_cmd)
2077 anchor = &ratelimiters_cmd;
2078
2079 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2080 {
2081 dbd = t->data.ptr;
2082 /* The following few lines duplicate some of the code below. */
2083 if (dbd->rate < limit) rc = FAIL;
2084 else rc = OK;
2085 store_pool = old_pool;
2086 sender_rate = string_sprintf("%.1f", dbd->rate);
2087 HDEBUG(D_acl)
2088 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2089 return rc;
2090 }
2091
2092 /* We aren't using a pre-computed rate, so get a previously recorded
2093 rate from the database, update it, and write it back. If there's no
2094 previous rate for this key, create one. */
2095
2096 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2097 if (dbm == NULL)
2098 {
2099 store_pool = old_pool;
2100 sender_rate = NULL;
2101 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2102 *log_msgptr = US"ratelimit database not available";
2103 return DEFER;
2104 }
2105 dbd = dbfn_read(dbm, key);
2106
2107 gettimeofday(&tv, NULL);
2108
2109 if (dbd == NULL)
2110 {
2111 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2112 dbd = store_get(sizeof(dbdata_ratelimit));
2113 dbd->time_stamp = tv.tv_sec;
2114 dbd->time_usec = tv.tv_usec;
2115 dbd->rate = 0.0;
2116 }
2117 else
2118 {
2119 /* The smoothed rate is computed using an exponentially weighted moving
2120 average adjusted for variable sampling intervals. The standard EWMA for
2121 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2122 where f() is the measured value and f'() is the smoothed value.
2123
2124 Old data decays out of the smoothed value exponentially, such that data n
2125 samples old is multiplied by a^n. The exponential decay time constant p
2126 is defined such that data p samples old is multiplied by 1/e, which means
2127 that a = exp(-1/p). We can maintain the same time constant for a variable
2128 sampling interval i by using a = exp(-i/p).
2129
2130 The rate we are measuring is messages per period, suitable for directly
2131 comparing with the limit. The average rate between now and the previous
2132 message is period / interval, which we feed into the EWMA as the sample.
2133
2134 It turns out that the number of messages required for the smoothed rate
2135 to reach the limit when they are sent in a burst is equal to the limit.
2136 This can be seen by analysing the value of the smoothed rate after N
2137 messages sent at even intervals. Let k = (1 - a) * p/i
2138
2139 rate_1 = (1 - a) * p/i + a * rate_0
2140 = k + a * rate_0
2141 rate_2 = k + a * rate_1
2142 = k + a * k + a^2 * rate_0
2143 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2144 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2145 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2146 = rate_0 * a^N + p/i * (1 - a^N)
2147
2148 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2149
2150 rate_N = p/i + (rate_0 - p/i) * a^N
2151 a^N = (rate_N - p/i) / (rate_0 - p/i)
2152 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2153 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2154
2155 Numerical analysis of the above equation, setting the computed rate to
2156 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2157 rates, p/i, the number of messages N = limit. So limit serves as both the
2158 maximum rate measured in messages per period, and the maximum number of
2159 messages that can be sent in a fast burst. */
2160
2161 double this_time = (double)tv.tv_sec
2162 + (double)tv.tv_usec / 1000000.0;
2163 double prev_time = (double)dbd->time_stamp
2164 + (double)dbd->time_usec / 1000000.0;
2165
2166 /* We must avoid division by zero, and deal gracefully with the clock going
2167 backwards. If we blunder ahead when time is in reverse then the computed
2168 rate will be bogus. To be safe we clamp interval to a very small number. */
2169
2170 double interval = this_time - prev_time <= 0.0 ? 1e-9
2171 : this_time - prev_time;
2172
2173 double i_over_p = interval / period;
2174 double a = exp(-i_over_p);
2175
2176 dbd->time_stamp = tv.tv_sec;
2177 dbd->time_usec = tv.tv_usec;
2178
2179 /* If we are measuring the rate in bytes per period, multiply the
2180 measured rate by the message size. If we don't know the message size
2181 then it's safe to just use a value of zero and let the recorded rate
2182 decay as if nothing happened. */
2183
2184 if (per_byte)
2185 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2186 * (1 - a) / i_over_p + a * dbd->rate;
2187 else
2188 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2189 }
2190
2191 /* Clients sending at the limit are considered to be over the limit. This
2192 matters for edge cases such the first message sent by a client (which gets
2193 the initial rate of 0.0) when the rate limit is zero (i.e. the client should
2194 be completely blocked). */
2195
2196 if (dbd->rate < limit) rc = FAIL;
2197 else rc = OK;
2198
2199 /* Update the state if the rate is low or if we are being strict. If we
2200 are in leaky mode and the sender's rate is too high, we do not update
2201 the recorded rate in order to avoid an over-aggressive sender's retry
2202 rate preventing them from getting any email through. */
2203
2204 if (rc == FAIL || !leaky)
2205 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2206 dbfn_close(dbm);
2207
2208 /* Store the result in the tree for future reference, if necessary. */
2209
2210 if (anchor != NULL)
2211 {
2212 t = store_get(sizeof(tree_node) + Ustrlen(key));
2213 t->data.ptr = dbd;
2214 Ustrcpy(t->name, key);
2215 (void)tree_insertnode(anchor, t);
2216 }
2217
2218 /* We create the formatted version of the sender's rate very late in
2219 order to ensure that it is done using the correct storage pool. */
2220
2221 store_pool = old_pool;
2222 sender_rate = string_sprintf("%.1f", dbd->rate);
2223
2224 HDEBUG(D_acl)
2225 debug_printf("ratelimit computed rate %s\n", sender_rate);
2226
2227 return rc;
2228 }
2229
2230
2231
2232 /*************************************************
2233 * Handle conditions/modifiers on an ACL item *
2234 *************************************************/
2235
2236 /* Called from acl_check() below.
2237
2238 Arguments:
2239 verb ACL verb
2240 cb ACL condition block - if NULL, result is OK
2241 where where called from
2242 addr the address being checked for RCPT, or NULL
2243 level the nesting level
2244 epp pointer to pass back TRUE if "endpass" encountered
2245 (applies only to "accept" and "discard")
2246 user_msgptr user message pointer
2247 log_msgptr log message pointer
2248 basic_errno pointer to where to put verify error
2249
2250 Returns: OK - all conditions are met
2251 DISCARD - an "acl" condition returned DISCARD - only allowed
2252 for "accept" or "discard" verbs
2253 FAIL - at least one condition fails
2254 FAIL_DROP - an "acl" condition returned FAIL_DROP
2255 DEFER - can't tell at the moment (typically, lookup defer,
2256 but can be temporary callout problem)
2257 ERROR - ERROR from nested ACL or expansion failure or other
2258 error
2259 */
2260
2261 static int
2262 acl_check_condition(int verb, acl_condition_block *cb, int where,
2263 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2264 uschar **log_msgptr, int *basic_errno)
2265 {
2266 uschar *user_message = NULL;
2267 uschar *log_message = NULL;
2268 uschar *p;
2269 int rc = OK;
2270 #ifdef WITH_CONTENT_SCAN
2271 int sep = '/';
2272 #endif
2273
2274 for (; cb != NULL; cb = cb->next)
2275 {
2276 uschar *arg;
2277 int control_type;
2278
2279 /* The message and log_message items set up messages to be used in
2280 case of rejection. They are expanded later. */
2281
2282 if (cb->type == ACLC_MESSAGE)
2283 {
2284 user_message = cb->arg;
2285 continue;
2286 }
2287
2288 if (cb->type == ACLC_LOG_MESSAGE)
2289 {
2290 log_message = cb->arg;
2291 continue;
2292 }
2293
2294 /* The endpass "condition" just sets a flag to show it occurred. This is
2295 checked at compile time to be on an "accept" or "discard" item. */
2296
2297 if (cb->type == ACLC_ENDPASS)
2298 {
2299 *epp = TRUE;
2300 continue;
2301 }
2302
2303 /* For other conditions and modifiers, the argument is expanded now for some
2304 of them, but not for all, because expansion happens down in some lower level
2305 checking functions in some cases. */
2306
2307 if (cond_expand_at_top[cb->type])
2308 {
2309 arg = expand_string(cb->arg);
2310 if (arg == NULL)
2311 {
2312 if (expand_string_forcedfail) continue;
2313 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2314 cb->arg, expand_string_message);
2315 return search_find_defer? DEFER : ERROR;
2316 }
2317 }
2318 else arg = cb->arg;
2319
2320 /* Show condition, and expanded condition if it's different */
2321
2322 HDEBUG(D_acl)
2323 {
2324 int lhswidth = 0;
2325 debug_printf("check %s%s %n",
2326 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2327 conditions[cb->type], &lhswidth);
2328
2329 if (cb->type == ACLC_SET)
2330 {
2331 int n = cb->u.varnumber;
2332 int t = (n < ACL_C_MAX)? 'c' : 'm';
2333 if (n >= ACL_C_MAX) n -= ACL_C_MAX;
2334 debug_printf("acl_%c%d ", t, n);
2335 lhswidth += 7;
2336 }
2337
2338 debug_printf("= %s\n", cb->arg);
2339
2340 if (arg != cb->arg)
2341 debug_printf("%.*s= %s\n", lhswidth,
2342 US" ", CS arg);
2343 }
2344
2345 /* Check that this condition makes sense at this time */
2346
2347 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2348 {
2349 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2350 cond_modifiers[cb->type]? "use" : "test",
2351 conditions[cb->type], acl_wherenames[where]);
2352 return ERROR;
2353 }
2354
2355 /* Run the appropriate test for each condition, or take the appropriate
2356 action for the remaining modifiers. */
2357
2358 switch(cb->type)
2359 {
2360 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2361 "discard" verb. */
2362
2363 case ACLC_ACL:
2364 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2365 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2366 {
2367 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2368 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2369 verbs[verb]);
2370 return ERROR;
2371 }
2372 break;
2373
2374 case ACLC_AUTHENTICATED:
2375 rc = (sender_host_authenticated == NULL)? FAIL :
2376 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2377 TRUE, NULL);
2378 break;
2379
2380 #ifdef EXPERIMENTAL_BRIGHTMAIL
2381 case ACLC_BMI_OPTIN:
2382 {
2383 int old_pool = store_pool;
2384 store_pool = POOL_PERM;
2385 bmi_current_optin = string_copy(arg);
2386 store_pool = old_pool;
2387 }
2388 break;
2389 #endif
2390
2391 case ACLC_CONDITION:
2392 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2393 rc = (Uatoi(arg) == 0)? FAIL : OK;
2394 else
2395 rc = (strcmpic(arg, US"no") == 0 ||
2396 strcmpic(arg, US"false") == 0)? FAIL :
2397 (strcmpic(arg, US"yes") == 0 ||
2398 strcmpic(arg, US"true") == 0)? OK : DEFER;
2399 if (rc == DEFER)
2400 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2401 break;
2402
2403 case ACLC_CONTROL:
2404 control_type = decode_control(arg, &p, where, log_msgptr);
2405
2406 /* Check if this control makes sense at this time */
2407
2408 if ((control_forbids[control_type] & (1 << where)) != 0)
2409 {
2410 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2411 controls[control_type], acl_wherenames[where]);
2412 return ERROR;
2413 }
2414
2415 switch(control_type)
2416 {
2417 #ifdef EXPERIMENTAL_BRIGHTMAIL
2418 case CONTROL_BMI_RUN:
2419 bmi_run = 1;
2420 break;
2421 #endif
2422 #ifdef EXPERIMENTAL_DOMAINKEYS
2423 case CONTROL_DK_VERIFY:
2424 dk_do_verify = 1;
2425 break;
2426 #endif
2427 case CONTROL_ERROR:
2428 return ERROR;
2429
2430 case CONTROL_CASEFUL_LOCAL_PART:
2431 deliver_localpart = addr->cc_local_part;
2432 break;
2433
2434 case CONTROL_CASELOWER_LOCAL_PART:
2435 deliver_localpart = addr->lc_local_part;
2436 break;
2437
2438 case CONTROL_ENFORCE_SYNC:
2439 smtp_enforce_sync = TRUE;
2440 break;
2441
2442 case CONTROL_NO_ENFORCE_SYNC:
2443 smtp_enforce_sync = FALSE;
2444 break;
2445
2446 #ifdef WITH_CONTENT_SCAN
2447 case CONTROL_NO_MBOX_UNSPOOL:
2448 no_mbox_unspool = TRUE;
2449 break;
2450 #endif
2451
2452 case CONTROL_NO_MULTILINE:
2453 no_multiline_responses = TRUE;
2454 break;
2455
2456 case CONTROL_FAKEDEFER:
2457 case CONTROL_FAKEREJECT:
2458 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2459 if (*p == '/')
2460 {
2461 uschar *pp = p + 1;
2462 while (*pp != 0) pp++;
2463 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2464 p = pp;
2465 }
2466 else
2467 {
2468 /* Explicitly reset to default string */
2469 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).";
2470 }
2471 break;
2472
2473 case CONTROL_FREEZE:
2474 deliver_freeze = TRUE;
2475 deliver_frozen_at = time(NULL);
2476 break;
2477
2478 case CONTROL_QUEUE_ONLY:
2479 queue_only_policy = TRUE;
2480 break;
2481
2482 case CONTROL_SUBMISSION:
2483 originator_name = US"";
2484 submission_mode = TRUE;
2485 while (*p == '/')
2486 {
2487 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2488 {
2489 p += 14;
2490 active_local_sender_retain = TRUE;
2491 active_local_from_check = FALSE;
2492 }
2493 else if (Ustrncmp(p, "/domain=", 8) == 0)
2494 {
2495 uschar *pp = p + 8;
2496 while (*pp != 0 && *pp != '/') pp++;
2497 submission_domain = string_copyn(p+8, pp-p-8);
2498 p = pp;
2499 }
2500 else if (Ustrncmp(p, "/name=", 6) == 0)
2501 {
2502 uschar *pp = p + 6;
2503 while (*pp != 0 && *pp != '/') pp++;
2504 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2505 big_buffer, big_buffer_size));
2506 p = pp;
2507 }
2508 else break;
2509 }
2510 if (*p != 0)
2511 {
2512 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2513 return ERROR;
2514 }
2515 break;
2516
2517 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
2518 suppress_local_fixups = TRUE;
2519 break;
2520 }
2521 break;
2522
2523 #ifdef WITH_CONTENT_SCAN
2524 case ACLC_DECODE:
2525 rc = mime_decode(&arg);
2526 break;
2527 #endif
2528
2529 case ACLC_DELAY:
2530 {
2531 int delay = readconf_readtime(arg, 0, FALSE);
2532 if (delay < 0)
2533 {
2534 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2535 "modifier: \"%s\" is not a time value", arg);
2536 return ERROR;
2537 }
2538 else
2539 {
2540 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2541 delay);
2542 if (host_checking)
2543 {
2544 HDEBUG(D_acl)
2545 debug_printf("delay skipped in -bh checking mode\n");
2546 }
2547
2548 /* It appears to be impossible to detect that a TCP/IP connection has
2549 gone away without reading from it. This means that we cannot shorten
2550 the delay below if the client goes away, because we cannot discover
2551 that the client has closed its end of the connection. (The connection
2552 is actually in a half-closed state, waiting for the server to close its
2553 end.) It would be nice to be able to detect this state, so that the
2554 Exim process is not held up unnecessarily. However, it seems that we
2555 can't. The poll() function does not do the right thing, and in any case
2556 it is not always available.
2557
2558 NOTE: If ever this state of affairs changes, remember that we may be
2559 dealing with stdin/stdout here, in addition to TCP/IP connections.
2560 Whatever is done must work in both cases. To detected the stdin/stdout
2561 case, check for smtp_in or smtp_out being NULL. */
2562
2563 else
2564 {
2565 while (delay > 0) delay = sleep(delay);
2566 }
2567 }
2568 }
2569 break;
2570
2571 #ifdef WITH_OLD_DEMIME
2572 case ACLC_DEMIME:
2573 rc = demime(&arg);
2574 break;
2575 #endif
2576
2577 #ifdef EXPERIMENTAL_DOMAINKEYS
2578 case ACLC_DK_DOMAIN_SOURCE:
2579 if (dk_verify_block == NULL) { rc = FAIL; break; };
2580 /* check header source of domain against given string */
2581 switch (dk_verify_block->address_source) {
2582 case DK_EXIM_ADDRESS_FROM_FROM:
2583 rc = match_isinlist(US"from", &arg, 0, NULL,
2584 NULL, MCL_STRING, TRUE, NULL);
2585 break;
2586 case DK_EXIM_ADDRESS_FROM_SENDER:
2587 rc = match_isinlist(US"sender", &arg, 0, NULL,
2588 NULL, MCL_STRING, TRUE, NULL);
2589 break;
2590 case DK_EXIM_ADDRESS_NONE:
2591 rc = match_isinlist(US"none", &arg, 0, NULL,
2592 NULL, MCL_STRING, TRUE, NULL);
2593 break;
2594 }
2595 break;
2596 case ACLC_DK_POLICY:
2597 if (dk_verify_block == NULL) { rc = FAIL; break; };
2598 /* check policy against given string, default FAIL */
2599 rc = FAIL;
2600 if (dk_verify_block->signsall)
2601 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2602 NULL, MCL_STRING, TRUE, NULL);
2603 if (dk_verify_block->testing)
2604 rc = match_isinlist(US"testing", &arg, 0, NULL,
2605 NULL, MCL_STRING, TRUE, NULL);
2606 break;
2607 case ACLC_DK_SENDER_DOMAINS:
2608 if (dk_verify_block == NULL) { rc = FAIL; break; };
2609 if (dk_verify_block->domain != NULL)
2610 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2611 NULL, MCL_DOMAIN, TRUE, NULL);
2612 else rc = FAIL;
2613 break;
2614 case ACLC_DK_SENDER_LOCAL_PARTS:
2615 if (dk_verify_block == NULL) { rc = FAIL; break; };
2616 if (dk_verify_block->local_part != NULL)
2617 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2618 NULL, MCL_LOCALPART, TRUE, NULL);
2619 else rc = FAIL;
2620 break;
2621 case ACLC_DK_SENDERS:
2622 if (dk_verify_block == NULL) { rc = FAIL; break; };
2623 if (dk_verify_block->address != NULL)
2624 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2625 else rc = FAIL;
2626 break;
2627 case ACLC_DK_STATUS:
2628 if (dk_verify_block == NULL) { rc = FAIL; break; };
2629 if (dk_verify_block->result > 0) {
2630 switch(dk_verify_block->result) {
2631 case DK_EXIM_RESULT_BAD_FORMAT:
2632 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2633 NULL, MCL_STRING, TRUE, NULL);
2634 break;
2635 case DK_EXIM_RESULT_NO_KEY:
2636 rc = match_isinlist(US"no key", &arg, 0, NULL,
2637 NULL, MCL_STRING, TRUE, NULL);
2638 break;
2639 case DK_EXIM_RESULT_NO_SIGNATURE:
2640 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2641 NULL, MCL_STRING, TRUE, NULL);
2642 break;
2643 case DK_EXIM_RESULT_REVOKED:
2644 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2645 NULL, MCL_STRING, TRUE, NULL);
2646 break;
2647 case DK_EXIM_RESULT_NON_PARTICIPANT:
2648 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2649 NULL, MCL_STRING, TRUE, NULL);
2650 break;
2651 case DK_EXIM_RESULT_GOOD:
2652 rc = match_isinlist(US"good", &arg, 0, NULL,
2653 NULL, MCL_STRING, TRUE, NULL);
2654 break;
2655 case DK_EXIM_RESULT_BAD:
2656 rc = match_isinlist(US"bad", &arg, 0, NULL,
2657 NULL, MCL_STRING, TRUE, NULL);
2658 break;
2659 }
2660 }
2661 break;
2662 #endif
2663
2664 case ACLC_DNSLISTS:
2665 rc = verify_check_dnsbl(&arg);
2666 break;
2667
2668 case ACLC_DOMAINS:
2669 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2670 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2671 break;
2672
2673 /* The value in tls_cipher is the full cipher name, for example,
2674 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2675 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2676 what may in practice come out of the SSL library - which at the time of
2677 writing is poorly documented. */
2678
2679 case ACLC_ENCRYPTED:
2680 if (tls_cipher == NULL) rc = FAIL; else
2681 {
2682 uschar *endcipher = NULL;
2683 uschar *cipher = Ustrchr(tls_cipher, ':');
2684 if (cipher == NULL) cipher = tls_cipher; else
2685 {
2686 endcipher = Ustrchr(++cipher, ':');
2687 if (endcipher != NULL) *endcipher = 0;
2688 }
2689 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2690 if (endcipher != NULL) *endcipher = ':';
2691 }
2692 break;
2693
2694 /* Use verify_check_this_host() instead of verify_check_host() so that
2695 we can pass over &host_data to catch any looked up data. Once it has been
2696 set, it retains its value so that it's still there if another ACL verb
2697 comes through here and uses the cache. However, we must put it into
2698 permanent store in case it is also expected to be used in a subsequent
2699 message in the same SMTP connection. */
2700
2701 case ACLC_HOSTS:
2702 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2703 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2704 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2705 break;
2706
2707 case ACLC_LOCAL_PARTS:
2708 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2709 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2710 &deliver_localpart_data);
2711 break;
2712
2713 case ACLC_LOGWRITE:
2714 {
2715 int logbits = 0;
2716 uschar *s = arg;
2717 if (*s == ':')
2718 {
2719 s++;
2720 while (*s != ':')
2721 {
2722 if (Ustrncmp(s, "main", 4) == 0)
2723 { logbits |= LOG_MAIN; s += 4; }
2724 else if (Ustrncmp(s, "panic", 5) == 0)
2725 { logbits |= LOG_PANIC; s += 5; }
2726 else if (Ustrncmp(s, "reject", 6) == 0)
2727 { logbits |= LOG_REJECT; s += 6; }
2728 else
2729 {
2730 logbits = LOG_MAIN|LOG_PANIC;
2731 s = string_sprintf(":unknown log name in \"%s\" in "
2732 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2733 }
2734 if (*s == ',') s++;
2735 }
2736 s++;
2737 }
2738 while (isspace(*s)) s++;
2739 if (logbits == 0) logbits = LOG_MAIN;
2740 log_write(0, logbits, "%s", string_printing(s));
2741 }
2742 break;
2743
2744 #ifdef WITH_CONTENT_SCAN
2745 case ACLC_MALWARE:
2746 {
2747 /* Seperate the regular expression and any optional parameters. */
2748 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2749 /* Run the malware backend. */
2750 rc = malware(&ss);
2751 /* Modify return code based upon the existance of options. */
2752 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2753 != NULL) {
2754 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2755 {
2756 /* FAIL so that the message is passed to the next ACL */
2757 rc = FAIL;
2758 }
2759 }
2760 }
2761 break;
2762
2763 case ACLC_MIME_REGEX:
2764 rc = mime_regex(&arg);
2765 break;
2766 #endif
2767
2768 case ACLC_RATELIMIT:
2769 rc = acl_ratelimit(arg, log_msgptr);
2770 break;
2771
2772 case ACLC_RECIPIENTS:
2773 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
2774 &recipient_data);
2775 break;
2776
2777 #ifdef WITH_CONTENT_SCAN
2778 case ACLC_REGEX:
2779 rc = regex(&arg);
2780 break;
2781 #endif
2782
2783 case ACLC_SENDER_DOMAINS:
2784 {
2785 uschar *sdomain;
2786 sdomain = Ustrrchr(sender_address, '@');
2787 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
2788 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
2789 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
2790 }
2791 break;
2792
2793 case ACLC_SENDERS:
2794 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
2795 sender_address_cache, -1, 0, &sender_data);
2796 break;
2797
2798 /* Connection variables must persist forever */
2799
2800 case ACLC_SET:
2801 {
2802 int old_pool = store_pool;
2803 if (cb->u.varnumber < ACL_C_MAX) store_pool = POOL_PERM;
2804 acl_var[cb->u.varnumber] = string_copy(arg);
2805 store_pool = old_pool;
2806 }
2807 break;
2808
2809 #ifdef WITH_CONTENT_SCAN
2810 case ACLC_SPAM:
2811 {
2812 /* Seperate the regular expression and any optional parameters. */
2813 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2814 /* Run the spam backend. */
2815 rc = spam(&ss);
2816 /* Modify return code based upon the existance of options. */
2817 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2818 != NULL) {
2819 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2820 {
2821 /* FAIL so that the message is passed to the next ACL */
2822 rc = FAIL;
2823 }
2824 }
2825 }
2826 break;
2827 #endif
2828
2829 #ifdef EXPERIMENTAL_SPF
2830 case ACLC_SPF:
2831 rc = spf_process(&arg, sender_address);
2832 break;
2833 #endif
2834
2835 /* If the verb is WARN, discard any user message from verification, because
2836 such messages are SMTP responses, not header additions. The latter come
2837 only from explicit "message" modifiers. However, put the user message into
2838 $acl_verify_message so it can be used in subsequent conditions or modifiers
2839 (until something changes it). */
2840
2841 case ACLC_VERIFY:
2842 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
2843 acl_verify_message = *user_msgptr;
2844 if (verb == ACL_WARN) *user_msgptr = NULL;
2845 break;
2846
2847 default:
2848 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
2849 "condition %d", cb->type);
2850 break;
2851 }
2852
2853 /* If a condition was negated, invert OK/FAIL. */
2854
2855 if (!cond_modifiers[cb->type] && cb->u.negated)
2856 {
2857 if (rc == OK) rc = FAIL;
2858 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
2859 }
2860
2861 if (rc != OK) break; /* Conditions loop */
2862 }
2863
2864
2865 /* If the result is the one for which "message" and/or "log_message" are used,
2866 handle the values of these options. Most verbs have but a single return for
2867 which the messages are relevant, but for "discard", it's useful to have the log
2868 message both when it succeeds and when it fails. Also, for an "accept" that
2869 appears in a QUIT ACL, we want to handle the user message. Since only "accept"
2870 and "warn" are permitted in that ACL, we don't need to test the verb.
2871
2872 These modifiers act in different ways:
2873
2874 "message" is a user message that will be included in an SMTP response. Unless
2875 it is empty, it overrides any previously set user message.
2876
2877 "log_message" is a non-user message, and it adds to any existing non-user
2878 message that is already set.
2879
2880 If there isn't a log message set, we make it the same as the user message. */
2881
2882 if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] ||
2883 (verb == ACL_DISCARD && rc == OK) ||
2884 (where == ACL_WHERE_QUIT))
2885 {
2886 uschar *expmessage;
2887
2888 /* If the verb is "warn", messages generated by conditions (verification or
2889 nested ACLs) are discarded. Only messages specified at this level are used.
2890 However, the value of an existing message is available in $acl_verify_message
2891 during expansions. */
2892
2893 uschar *old_user_msgptr = *user_msgptr;
2894 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
2895
2896 if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL;
2897
2898 if (user_message != NULL)
2899 {
2900 acl_verify_message = old_user_msgptr;
2901 expmessage = expand_string(user_message);
2902 if (expmessage == NULL)
2903 {
2904 if (!expand_string_forcedfail)
2905 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2906 user_message, expand_string_message);
2907 }
2908 else if (expmessage[0] != 0) *user_msgptr = expmessage;
2909 }
2910
2911 if (log_message != NULL)
2912 {
2913 acl_verify_message = old_log_msgptr;
2914 expmessage = expand_string(log_message);
2915 if (expmessage == NULL)
2916 {
2917 if (!expand_string_forcedfail)
2918 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2919 log_message, expand_string_message);
2920 }
2921 else if (expmessage[0] != 0)
2922 {
2923 *log_msgptr = (*log_msgptr == NULL)? expmessage :
2924 string_sprintf("%s: %s", expmessage, *log_msgptr);
2925 }
2926 }
2927
2928 /* If no log message, default it to the user message */
2929
2930 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
2931 }
2932
2933 acl_verify_message = NULL;
2934 return rc;
2935 }
2936
2937
2938
2939
2940
2941 /*************************************************
2942 * Get line from a literal ACL *
2943 *************************************************/
2944
2945 /* This function is passed to acl_read() in order to extract individual lines
2946 of a literal ACL, which we access via static pointers. We can destroy the
2947 contents because this is called only once (the compiled ACL is remembered).
2948
2949 This code is intended to treat the data in the same way as lines in the main
2950 Exim configuration file. That is:
2951
2952 . Leading spaces are ignored.
2953
2954 . A \ at the end of a line is a continuation - trailing spaces after the \
2955 are permitted (this is because I don't believe in making invisible things
2956 significant). Leading spaces on the continued part of a line are ignored.
2957
2958 . Physical lines starting (significantly) with # are totally ignored, and
2959 may appear within a sequence of backslash-continued lines.
2960
2961 . Blank lines are ignored, but will end a sequence of continuations.
2962
2963 Arguments: none
2964 Returns: a pointer to the next line
2965 */
2966
2967
2968 static uschar *acl_text; /* Current pointer in the text */
2969 static uschar *acl_text_end; /* Points one past the terminating '0' */
2970
2971
2972 static uschar *
2973 acl_getline(void)
2974 {
2975 uschar *yield;
2976
2977 /* This loop handles leading blank lines and comments. */
2978
2979 for(;;)
2980 {
2981 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
2982 if (*acl_text == 0) return NULL; /* No more data */
2983 yield = acl_text; /* Potential data line */
2984
2985 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
2986
2987 /* If we hit the end before a newline, we have the whole logical line. If
2988 it's a comment, there's no more data to be given. Otherwise, yield it. */
2989
2990 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
2991
2992 /* After reaching a newline, end this loop if the physical line does not
2993 start with '#'. If it does, it's a comment, and the loop continues. */
2994
2995 if (*yield != '#') break;
2996 }
2997
2998 /* This loop handles continuations. We know we have some real data, ending in
2999 newline. See if there is a continuation marker at the end (ignoring trailing
3000 white space). We know that *yield is not white space, so no need to test for
3001 cont > yield in the backwards scanning loop. */
3002
3003 for(;;)
3004 {
3005 uschar *cont;
3006 for (cont = acl_text - 1; isspace(*cont); cont--);
3007
3008 /* If no continuation follows, we are done. Mark the end of the line and
3009 return it. */
3010
3011 if (*cont != '\\')
3012 {
3013 *acl_text++ = 0;
3014 return yield;
3015 }
3016
3017 /* We have encountered a continuation. Skip over whitespace at the start of
3018 the next line, and indeed the whole of the next line or lines if they are
3019 comment lines. */
3020
3021 for (;;)
3022 {
3023 while (*(++acl_text) == ' ' || *acl_text == '\t');
3024 if (*acl_text != '#') break;
3025 while (*(++acl_text) != 0 && *acl_text != '\n');
3026 }
3027
3028 /* We have the start of a continuation line. Move all the rest of the data
3029 to join onto the previous line, and then find its end. If the end is not a
3030 newline, we are done. Otherwise loop to look for another continuation. */
3031
3032 memmove(cont, acl_text, acl_text_end - acl_text);
3033 acl_text_end -= acl_text - cont;
3034 acl_text = cont;
3035 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3036 if (*acl_text == 0) return yield;
3037 }
3038
3039 /* Control does not reach here */
3040 }
3041
3042
3043
3044
3045
3046 /*************************************************
3047 * Check access using an ACL *
3048 *************************************************/
3049
3050 /* This function is called from address_check. It may recurse via
3051 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3052 passed as a string which is expanded. A forced failure implies no access check
3053 is required. If the result is a single word, it is taken as the name of an ACL
3054 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3055 text, complete with newlines, and parsed as such. In both cases, the ACL check
3056 is then run. This function uses an auxiliary function for acl_read() to call
3057 for reading individual lines of a literal ACL. This is acl_getline(), which
3058 appears immediately above.
3059
3060 Arguments:
3061 where where called from
3062 addr address item when called from RCPT; otherwise NULL
3063 s the input string; NULL is the same as an empty ACL => DENY
3064 level the nesting level
3065 user_msgptr where to put a user error (for SMTP response)
3066 log_msgptr where to put a logging message (not for SMTP response)
3067
3068 Returns: OK access is granted
3069 DISCARD access is apparently granted...
3070 FAIL access is denied
3071 FAIL_DROP access is denied; drop the connection
3072 DEFER can't tell at the moment
3073 ERROR disaster
3074 */
3075
3076 static int
3077 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3078 uschar **user_msgptr, uschar **log_msgptr)
3079 {
3080 int fd = -1;
3081 acl_block *acl = NULL;
3082 uschar *acl_name = US"inline ACL";
3083 uschar *ss;
3084
3085 /* Catch configuration loops */
3086
3087 if (level > 20)
3088 {
3089 *log_msgptr = US"ACL nested too deep: possible loop";
3090 return ERROR;
3091 }
3092
3093 if (s == NULL)
3094 {
3095 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3096 return FAIL;
3097 }
3098
3099 /* At top level, we expand the incoming string. At lower levels, it has already
3100 been expanded as part of condition processing. */
3101
3102 if (level == 0)
3103 {
3104 ss = expand_string(s);
3105 if (ss == NULL)
3106 {
3107 if (expand_string_forcedfail) return OK;
3108 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3109 expand_string_message);
3110 return ERROR;
3111 }
3112 }
3113 else ss = s;
3114
3115 while (isspace(*ss))ss++;
3116
3117 /* If we can't find a named ACL, the default is to parse it as an inline one.
3118 (Unless it begins with a slash; non-existent files give rise to an error.) */
3119
3120 acl_text = ss;
3121
3122 /* Handle the case of a string that does not contain any spaces. Look for a
3123 named ACL among those read from the configuration, or a previously read file.
3124 It is possible that the pointer to the ACL is NULL if the configuration
3125 contains a name with no data. If not found, and the text begins with '/',
3126 read an ACL from a file, and save it so it can be re-used. */
3127
3128 if (Ustrchr(ss, ' ') == NULL)
3129 {
3130 tree_node *t = tree_search(acl_anchor, ss);
3131 if (t != NULL)
3132 {
3133 acl = (acl_block *)(t->data.ptr);
3134 if (acl == NULL)
3135 {
3136 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3137 return FAIL;
3138 }
3139 acl_name = string_sprintf("ACL \"%s\"", ss);
3140 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3141 }
3142
3143 else if (*ss == '/')
3144 {
3145 struct stat statbuf;
3146 fd = Uopen(ss, O_RDONLY, 0);
3147 if (fd < 0)
3148 {
3149 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3150 strerror(errno));
3151 return ERROR;
3152 }
3153
3154 if (fstat(fd, &statbuf) != 0)
3155 {
3156 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3157 strerror(errno));
3158 return ERROR;
3159 }
3160
3161 acl_text = store_get(statbuf.st_size + 1);
3162 acl_text_end = acl_text + statbuf.st_size + 1;
3163
3164 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3165 {
3166 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3167 ss, strerror(errno));
3168 return ERROR;
3169 }
3170 acl_text[statbuf.st_size] = 0;
3171 (void)close(fd);
3172
3173 acl_name = string_sprintf("ACL \"%s\"", ss);
3174 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3175 }
3176 }
3177
3178 /* Parse an ACL that is still in text form. If it came from a file, remember it
3179 in the ACL tree, having read it into the POOL_PERM store pool so that it
3180 persists between multiple messages. */
3181
3182 if (acl == NULL)
3183 {
3184 int old_pool = store_pool;
3185 if (fd >= 0) store_pool = POOL_PERM;
3186 acl = acl_read(acl_getline, log_msgptr);
3187 store_pool = old_pool;
3188 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3189 if (fd >= 0)
3190 {
3191 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3192 Ustrcpy(t->name, ss);
3193 t->data.ptr = acl;
3194 (void)tree_insertnode(&acl_anchor, t);
3195 }
3196 }
3197
3198 /* Now we have an ACL to use. It's possible it may be NULL. */
3199
3200 while (acl != NULL)
3201 {
3202 int cond;
3203 int basic_errno = 0;
3204 BOOL endpass_seen = FALSE;
3205
3206 *log_msgptr = *user_msgptr = NULL;
3207 acl_temp_details = FALSE;
3208
3209 if (where == ACL_WHERE_QUIT &&
3210 acl->verb != ACL_ACCEPT &&
3211 acl->verb != ACL_WARN)
3212 {
3213 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3214 verbs[acl->verb]);
3215 return ERROR;
3216 }
3217
3218 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3219
3220 /* Clear out any search error message from a previous check before testing
3221 this condition. */
3222
3223 search_error_message = NULL;
3224 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3225 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3226
3227 /* Handle special returns: DEFER causes a return except on a WARN verb;
3228 ERROR always causes a return. */
3229
3230 switch (cond)
3231 {
3232 case DEFER:
3233 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3234 if (basic_errno != ERRNO_CALLOUTDEFER)
3235 {
3236 if (search_error_message != NULL && *search_error_message != 0)
3237 *log_msgptr = search_error_message;
3238 if (smtp_return_error_details) acl_temp_details = TRUE;
3239 }
3240 else
3241 {
3242 acl_temp_details = TRUE;
3243 }
3244 if (acl->verb != ACL_WARN) return DEFER;
3245 break;
3246
3247 default: /* Paranoia */
3248 case ERROR:
3249 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3250 return ERROR;
3251
3252 case OK:
3253 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3254 verbs[acl->verb]);
3255 break;
3256
3257 case FAIL:
3258 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3259 break;
3260
3261 /* DISCARD and DROP can happen only from a nested ACL condition, and
3262 DISCARD can happen only for an "accept" or "discard" verb. */
3263
3264 case DISCARD:
3265 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3266 verbs[acl->verb]);
3267 break;
3268
3269 case FAIL_DROP:
3270 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3271 verbs[acl->verb]);
3272 break;
3273 }
3274
3275 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3276 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3277 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3278
3279 switch(acl->verb)
3280 {
3281 case ACL_ACCEPT:
3282 if (cond == OK || cond == DISCARD) return cond;
3283 if (endpass_seen)
3284 {
3285 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3286 return cond;
3287 }
3288 break;
3289
3290 case ACL_DEFER:
3291 if (cond == OK)
3292 {
3293 acl_temp_details = TRUE;
3294 return DEFER;
3295 }
3296 break;
3297
3298 case ACL_DENY:
3299 if (cond == OK) return FAIL;
3300 break;
3301
3302 case ACL_DISCARD:
3303 if (cond == OK || cond == DISCARD) return DISCARD;
3304 if (endpass_seen)
3305 {
3306 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3307 return cond;
3308 }
3309 break;
3310
3311 case ACL_DROP:
3312 if (cond == OK) return FAIL_DROP;
3313 break;
3314
3315 case ACL_REQUIRE:
3316 if (cond != OK) return cond;
3317 break;
3318
3319 case ACL_WARN:
3320 if (cond == OK)
3321 acl_warn(where, *user_msgptr, *log_msgptr);
3322 else if (cond == DEFER)
3323 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3324 "condition test deferred%s%s", host_and_ident(TRUE),
3325 (*log_msgptr == NULL)? US"" : US": ",
3326 (*log_msgptr == NULL)? US"" : *log_msgptr);
3327 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3328 break;
3329
3330 default:
3331 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3332 acl->verb);
3333 break;
3334 }
3335
3336 /* Pass to the next ACL item */
3337
3338 acl = acl->next;
3339 }
3340
3341 /* We have reached the end of the ACL. This is an implicit DENY. */
3342
3343 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3344 return FAIL;
3345 }
3346
3347
3348 /*************************************************
3349 * Check access using an ACL *
3350 *************************************************/
3351
3352 /* This is the external interface for ACL checks. It sets up an address and the
3353 expansions for $domain and $local_part when called after RCPT, then calls
3354 acl_check_internal() to do the actual work.
3355
3356 Arguments:
3357 where ACL_WHERE_xxxx indicating where called from
3358 recipient RCPT address for RCPT check, else NULL
3359 s the input string; NULL is the same as an empty ACL => DENY
3360 user_msgptr where to put a user error (for SMTP response)
3361 log_msgptr where to put a logging message (not for SMTP response)
3362
3363 Returns: OK access is granted by an ACCEPT verb
3364 DISCARD access is granted by a DISCARD verb
3365 FAIL access is denied
3366 FAIL_DROP access is denied; drop the connection
3367 DEFER can't tell at the moment
3368 ERROR disaster
3369 */
3370
3371 int
3372 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
3373 uschar **log_msgptr)
3374 {
3375 int rc;
3376 address_item adb;
3377 address_item *addr = NULL;
3378
3379 *user_msgptr = *log_msgptr = NULL;
3380 sender_verified_failed = NULL;
3381 ratelimiters_cmd = NULL;
3382
3383 if (where == ACL_WHERE_RCPT)
3384 {
3385 adb = address_defaults;
3386 addr = &adb;
3387 addr->address = recipient;
3388 if (deliver_split_address(addr) == DEFER)
3389 {
3390 *log_msgptr = US"defer in percent_hack_domains check";
3391 return DEFER;
3392 }
3393 deliver_domain = addr->domain;
3394 deliver_localpart = addr->local_part;
3395 }
3396
3397 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3398
3399 deliver_domain = deliver_localpart = deliver_address_data =
3400 sender_address_data = NULL;
3401
3402 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3403 ACL, which is really in the middle of an SMTP command. */
3404
3405 if (rc == DISCARD)
3406 {
3407 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3408 {
3409 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3410 "ACL", acl_wherenames[where]);
3411 return ERROR;
3412 }
3413 return DISCARD;
3414 }
3415
3416 /* A DROP response is not permitted from MAILAUTH */
3417
3418 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3419 {
3420 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3421 "ACL", acl_wherenames[where]);
3422 return ERROR;
3423 }
3424
3425 /* Before giving an error response, take a look at the length of any user
3426 message, and split it up into multiple lines if possible. */
3427
3428 if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75)
3429 {
3430 uschar *s = *user_msgptr = string_copy(*user_msgptr);
3431 uschar *ss = s;
3432
3433 for (;;)
3434 {
3435 int i = 0;
3436 while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++;
3437 if (*ss == 0) break;
3438 if (*ss == '\n')
3439 s = ++ss;
3440 else
3441 {
3442 uschar *t = ss + 1;
3443 uschar *tt = NULL;
3444 while (--t > s + 35)
3445 {
3446 if (*t == ' ')
3447 {
3448 if (t[-1] == ':') { tt = t; break; }
3449 if (tt == NULL) tt = t;
3450 }
3451 }
3452
3453 if (tt == NULL) /* Can't split behind - try ahead */
3454 {
3455 t = ss + 1;
3456 while (*t != 0)
3457 {
3458 if (*t == ' ' || *t == '\n')
3459 { tt = t; break; }
3460 t++;
3461 }
3462 }