f5949f04f296c7b5b19a9394f37fdd82b405d9a3
[exim.git] / src / src / acl.c
1 /* $Cambridge: exim/src/src/acl.c,v 1.54 2006/02/07 11:19:00 ph10 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2006 */
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 int offset, max, n;
756 uschar *endptr;
757
758 if (Ustrncmp(s, "acl_", 4) != 0) goto BAD_ACL_VAR;
759 if (s[4] == 'c')
760 {
761 offset = 0;
762 max = ACL_CVARS;
763 }
764 else if (s[4] == 'm')
765 {
766 offset = ACL_CVARS;
767 max = ACL_MVARS;
768 }
769 else goto BAD_ACL_VAR;
770
771 n = Ustrtoul(s + 5, &endptr, 10);
772 if ((*endptr != 0 && *endptr != '=' && !isspace(*endptr)) || n >= max)
773 {
774 BAD_ACL_VAR:
775 *error = string_sprintf("syntax error or unrecognized name after "
776 "\"set\" in ACL modifier \"set %s\"", s);
777 return NULL;
778 }
779
780 cond->u.varnumber = n + offset;
781 s = endptr;
782 while (isspace(*s)) s++;
783 }
784
785 /* For "set", we are now positioned for the data. For the others, only
786 "endpass" has no data */
787
788 if (c != ACLC_ENDPASS)
789 {
790 if (*s++ != '=')
791 {
792 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
793 cond_modifiers[c]? US"modifier" : US"condition");
794 return NULL;
795 }
796 while (isspace(*s)) s++;
797 cond->arg = string_copy(s);
798 }
799 }
800
801 return yield;
802 }
803
804
805
806 /*************************************************
807 * Handle warnings *
808 *************************************************/
809
810 /* This function is called when a WARN verb's conditions are true. It adds to
811 the message's headers, and/or writes information to the log. In each case, this
812 only happens once (per message for headers, per connection for log).
813
814 Arguments:
815 where ACL_WHERE_xxxx indicating which ACL this is
816 user_message message for adding to headers
817 log_message message for logging, if different
818
819 Returns: nothing
820 */
821
822 static void
823 acl_warn(int where, uschar *user_message, uschar *log_message)
824 {
825 int hlen;
826
827 if (log_message != NULL && log_message != user_message)
828 {
829 uschar *text;
830 string_item *logged;
831
832 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
833 string_printing(log_message));
834
835 /* If a sender verification has failed, and the log message is "sender verify
836 failed", add the failure message. */
837
838 if (sender_verified_failed != NULL &&
839 sender_verified_failed->message != NULL &&
840 strcmpic(log_message, US"sender verify failed") == 0)
841 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
842
843 /* Search previously logged warnings. They are kept in malloc
844 store so they can be freed at the start of a new message. */
845
846 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
847 if (Ustrcmp(logged->text, text) == 0) break;
848
849 if (logged == NULL)
850 {
851 int length = Ustrlen(text) + 1;
852 log_write(0, LOG_MAIN, "%s", text);
853 logged = store_malloc(sizeof(string_item) + length);
854 logged->text = (uschar *)logged + sizeof(string_item);
855 memcpy(logged->text, text, length);
856 logged->next = acl_warn_logged;
857 acl_warn_logged = logged;
858 }
859 }
860
861 /* If there's no user message, we are done. */
862
863 if (user_message == NULL) return;
864
865 /* If this isn't a message ACL, we can't do anything with a user message.
866 Log an error. */
867
868 if (where > ACL_WHERE_NOTSMTP)
869 {
870 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
871 "found in a non-message (%s) ACL: cannot specify header lines here: "
872 "message ignored", acl_wherenames[where]);
873 return;
874 }
875
876 /* Treat the user message as a sequence of one or more header lines. */
877
878 hlen = Ustrlen(user_message);
879 if (hlen > 0)
880 {
881 uschar *text, *p, *q;
882
883 /* Add a final newline if not present */
884
885 text = ((user_message)[hlen-1] == '\n')? user_message :
886 string_sprintf("%s\n", user_message);
887
888 /* Loop for multiple header lines, taking care about continuations */
889
890 for (p = q = text; *p != 0; )
891 {
892 uschar *s;
893 int newtype = htype_add_bot;
894 header_line **hptr = &acl_warn_headers;
895
896 /* Find next header line within the string */
897
898 for (;;)
899 {
900 q = Ustrchr(q, '\n');
901 if (*(++q) != ' ' && *q != '\t') break;
902 }
903
904 /* If the line starts with a colon, interpret the instruction for where to
905 add it. This temporarily sets up a new type. */
906
907 if (*p == ':')
908 {
909 if (strncmpic(p, US":after_received:", 16) == 0)
910 {
911 newtype = htype_add_rec;
912 p += 16;
913 }
914 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
915 {
916 newtype = htype_add_rfc;
917 p += 14;
918 }
919 else if (strncmpic(p, US":at_start:", 10) == 0)
920 {
921 newtype = htype_add_top;
922 p += 10;
923 }
924 else if (strncmpic(p, US":at_end:", 8) == 0)
925 {
926 newtype = htype_add_bot;
927 p += 8;
928 }
929 while (*p == ' ' || *p == '\t') p++;
930 }
931
932 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
933 to the front of it. */
934
935 for (s = p; s < q - 1; s++)
936 {
937 if (*s == ':' || !isgraph(*s)) break;
938 }
939
940 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p);
941 hlen = Ustrlen(s);
942
943 /* See if this line has already been added */
944
945 while (*hptr != NULL)
946 {
947 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
948 hptr = &((*hptr)->next);
949 }
950
951 /* Add if not previously present */
952
953 if (*hptr == NULL)
954 {
955 header_line *h = store_get(sizeof(header_line));
956 h->text = s;
957 h->next = NULL;
958 h->type = newtype;
959 h->slen = hlen;
960 *hptr = h;
961 hptr = &(h->next);
962 }
963
964 /* Advance for next header line within the string */
965
966 p = q;
967 }
968 }
969 }
970
971
972
973 /*************************************************
974 * Verify and check reverse DNS *
975 *************************************************/
976
977 /* Called from acl_verify() below. We look up the host name(s) of the client IP
978 address if this has not yet been done. The host_name_lookup() function checks
979 that one of these names resolves to an address list that contains the client IP
980 address, so we don't actually have to do the check here.
981
982 Arguments:
983 user_msgptr pointer for user message
984 log_msgptr pointer for log message
985
986 Returns: OK verification condition succeeded
987 FAIL verification failed
988 DEFER there was a problem verifying
989 */
990
991 static int
992 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
993 {
994 int rc;
995
996 user_msgptr = user_msgptr; /* stop compiler warning */
997
998 /* Previous success */
999
1000 if (sender_host_name != NULL) return OK;
1001
1002 /* Previous failure */
1003
1004 if (host_lookup_failed)
1005 {
1006 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1007 return FAIL;
1008 }
1009
1010 /* Need to do a lookup */
1011
1012 HDEBUG(D_acl)
1013 debug_printf("looking up host name to force name/address consistency check\n");
1014
1015 if ((rc = host_name_lookup()) != OK)
1016 {
1017 *log_msgptr = (rc == DEFER)?
1018 US"host lookup deferred for reverse lookup check"
1019 :
1020 string_sprintf("host lookup failed for reverse lookup check%s",
1021 host_lookup_msg);
1022 return rc; /* DEFER or FAIL */
1023 }
1024
1025 host_build_sender_fullhost();
1026 return OK;
1027 }
1028
1029
1030
1031 /*************************************************
1032 * Check client IP address matches CSA target *
1033 *************************************************/
1034
1035 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1036 response for address records belonging to the CSA target hostname. The section
1037 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1038 If one of the addresses matches the client's IP address, then the client is
1039 authorized by CSA. If there are target IP addresses but none of them match
1040 then the client is using an unauthorized IP address. If there are no target IP
1041 addresses then the client cannot be using an authorized IP address. (This is
1042 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1043
1044 Arguments:
1045 dnsa the DNS answer block
1046 dnss a DNS scan block for us to use
1047 reset option specifing what portion to scan, as described above
1048 target the target hostname to use for matching RR names
1049
1050 Returns: CSA_OK successfully authorized
1051 CSA_FAIL_MISMATCH addresses found but none matched
1052 CSA_FAIL_NOADDR no target addresses found
1053 */
1054
1055 static int
1056 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1057 uschar *target)
1058 {
1059 dns_record *rr;
1060 dns_address *da;
1061
1062 BOOL target_found = FALSE;
1063
1064 for (rr = dns_next_rr(dnsa, dnss, reset);
1065 rr != NULL;
1066 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1067 {
1068 /* Check this is an address RR for the target hostname. */
1069
1070 if (rr->type != T_A
1071 #if HAVE_IPV6
1072 && rr->type != T_AAAA
1073 #ifdef SUPPORT_A6
1074 && rr->type != T_A6
1075 #endif
1076 #endif
1077 ) continue;
1078
1079 if (strcmpic(target, rr->name) != 0) continue;
1080
1081 target_found = TRUE;
1082
1083 /* Turn the target address RR into a list of textual IP addresses and scan
1084 the list. There may be more than one if it is an A6 RR. */
1085
1086 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1087 {
1088 /* If the client IP address matches the target IP address, it's good! */
1089
1090 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1091
1092 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1093 }
1094 }
1095
1096 /* If we found some target addresses but none of them matched, the client is
1097 using an unauthorized IP address, otherwise the target has no authorized IP
1098 addresses. */
1099
1100 if (target_found) return CSA_FAIL_MISMATCH;
1101 else return CSA_FAIL_NOADDR;
1102 }
1103
1104
1105
1106 /*************************************************
1107 * Verify Client SMTP Authorization *
1108 *************************************************/
1109
1110 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1111 to find the CSA SRV record corresponding to the domain argument, or
1112 $sender_helo_name if no argument is provided. It then checks that the
1113 client is authorized, and that its IP address corresponds to the SRV
1114 target's address by calling acl_verify_csa_address() above. The address
1115 should have been returned in the DNS response's ADDITIONAL section, but if
1116 not we perform another DNS lookup to get it.
1117
1118 Arguments:
1119 domain pointer to optional parameter following verify = csa
1120
1121 Returns: CSA_UNKNOWN no valid CSA record found
1122 CSA_OK successfully authorized
1123 CSA_FAIL_* client is definitely not authorized
1124 CSA_DEFER_* there was a DNS problem
1125 */
1126
1127 static int
1128 acl_verify_csa(uschar *domain)
1129 {
1130 tree_node *t;
1131 uschar *found, *p;
1132 int priority, weight, port;
1133 dns_answer dnsa;
1134 dns_scan dnss;
1135 dns_record *rr;
1136 int rc, type;
1137 uschar target[256];
1138
1139 /* Work out the domain we are using for the CSA lookup. The default is the
1140 client's HELO domain. If the client has not said HELO, use its IP address
1141 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1142
1143 while (isspace(*domain) && *domain != '\0') ++domain;
1144 if (*domain == '\0') domain = sender_helo_name;
1145 if (domain == NULL) domain = sender_host_address;
1146 if (sender_host_address == NULL) return CSA_UNKNOWN;
1147
1148 /* If we have an address literal, strip off the framing ready for turning it
1149 into a domain. The framing consists of matched square brackets possibly
1150 containing a keyword and a colon before the actual IP address. */
1151
1152 if (domain[0] == '[')
1153 {
1154 uschar *start = Ustrchr(domain, ':');
1155 if (start == NULL) start = domain;
1156 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1157 }
1158
1159 /* Turn domains that look like bare IP addresses into domains in the reverse
1160 DNS. This code also deals with address literals and $sender_host_address. It's
1161 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1162 address literals, but it's probably the most friendly thing to do. This is an
1163 extension to CSA, so we allow it to be turned off for proper conformance. */
1164
1165 if (string_is_ip_address(domain, NULL) != 0)
1166 {
1167 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1168 dns_build_reverse(domain, target);
1169 domain = target;
1170 }
1171
1172 /* Find out if we've already done the CSA check for this domain. If we have,
1173 return the same result again. Otherwise build a new cached result structure
1174 for this domain. The name is filled in now, and the value is filled in when
1175 we return from this function. */
1176
1177 t = tree_search(csa_cache, domain);
1178 if (t != NULL) return t->data.val;
1179
1180 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1181 Ustrcpy(t->name, domain);
1182 (void)tree_insertnode(&csa_cache, t);
1183
1184 /* Now we are ready to do the actual DNS lookup(s). */
1185
1186 found = domain;
1187 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1188 {
1189 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1190
1191 default:
1192 return t->data.val = CSA_DEFER_SRV;
1193
1194 /* If we found nothing, the client's authorization is unknown. */
1195
1196 case DNS_NOMATCH:
1197 case DNS_NODATA:
1198 return t->data.val = CSA_UNKNOWN;
1199
1200 /* We got something! Go on to look at the reply in more detail. */
1201
1202 case DNS_SUCCEED:
1203 break;
1204 }
1205
1206 /* Scan the reply for well-formed CSA SRV records. */
1207
1208 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1209 rr != NULL;
1210 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1211 {
1212 if (rr->type != T_SRV) continue;
1213
1214 /* Extract the numerical SRV fields (p is incremented) */
1215
1216 p = rr->data;
1217 GETSHORT(priority, p);
1218 GETSHORT(weight, p);
1219 GETSHORT(port, p);
1220
1221 DEBUG(D_acl)
1222 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1223
1224 /* Check the CSA version number */
1225
1226 if (priority != 1) continue;
1227
1228 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1229 found by dns_special_lookup() is a parent of the one we asked for), we check
1230 the subdomain assertions in the port field. At the moment there's only one
1231 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1232 SRV records of their own. */
1233
1234 if (found != domain)
1235 {
1236 if (port & 1)
1237 return t->data.val = CSA_FAIL_EXPLICIT;
1238 else
1239 return t->data.val = CSA_UNKNOWN;
1240 }
1241
1242 /* This CSA SRV record refers directly to our domain, so we check the value
1243 in the weight field to work out the domain's authorization. 0 and 1 are
1244 unauthorized; 3 means the client is authorized but we can't check the IP
1245 address in order to authenticate it, so we treat it as unknown; values
1246 greater than 3 are undefined. */
1247
1248 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1249
1250 if (weight > 2) continue;
1251
1252 /* Weight == 2, which means the domain is authorized. We must check that the
1253 client's IP address is listed as one of the SRV target addresses. Save the
1254 target hostname then break to scan the additional data for its addresses. */
1255
1256 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1257 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1258
1259 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1260
1261 break;
1262 }
1263
1264 /* If we didn't break the loop then no appropriate records were found. */
1265
1266 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1267
1268 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1269 A target of "." indicates there are no valid addresses, so the client cannot
1270 be authorized. (This is an odd configuration because weight=2 target=. is
1271 equivalent to weight=1, but we check for it in order to keep load off the
1272 root name servers.) Note that dn_expand() turns "." into "". */
1273
1274 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1275
1276 /* Scan the additional section of the CSA SRV reply for addresses belonging
1277 to the target. If the name server didn't return any additional data (e.g.
1278 because it does not fully support SRV records), we need to do another lookup
1279 to obtain the target addresses; otherwise we have a definitive result. */
1280
1281 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1282 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1283
1284 /* The DNS lookup type corresponds to the IP version used by the client. */
1285
1286 #if HAVE_IPV6
1287 if (Ustrchr(sender_host_address, ':') != NULL)
1288 type = T_AAAA;
1289 else
1290 #endif /* HAVE_IPV6 */
1291 type = T_A;
1292
1293
1294 #if HAVE_IPV6 && defined(SUPPORT_A6)
1295 DNS_LOOKUP_AGAIN:
1296 #endif
1297
1298 switch (dns_lookup(&dnsa, target, type, NULL))
1299 {
1300 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1301
1302 default:
1303 return t->data.val = CSA_DEFER_ADDR;
1304
1305 /* If the query succeeded, scan the addresses and return the result. */
1306
1307 case DNS_SUCCEED:
1308 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1309 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1310 /* else fall through */
1311
1312 /* If the target has no IP addresses, the client cannot have an authorized
1313 IP address. However, if the target site uses A6 records (not AAAA records)
1314 we have to do yet another lookup in order to check them. */
1315
1316 case DNS_NOMATCH:
1317 case DNS_NODATA:
1318
1319 #if HAVE_IPV6 && defined(SUPPORT_A6)
1320 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1321 #endif
1322
1323 return t->data.val = CSA_FAIL_NOADDR;
1324 }
1325 }
1326
1327
1328
1329 /*************************************************
1330 * Handle verification (address & other) *
1331 *************************************************/
1332
1333 /* This function implements the "verify" condition. It is called when
1334 encountered in any ACL, because some tests are almost always permitted. Some
1335 just don't make sense, and always fail (for example, an attempt to test a host
1336 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1337
1338 Arguments:
1339 where where called from
1340 addr the recipient address that the ACL is handling, or NULL
1341 arg the argument of "verify"
1342 user_msgptr pointer for user message
1343 log_msgptr pointer for log message
1344 basic_errno where to put verify errno
1345
1346 Returns: OK verification condition succeeded
1347 FAIL verification failed
1348 DEFER there was a problem verifying
1349 ERROR syntax error
1350 */
1351
1352 static int
1353 acl_verify(int where, address_item *addr, uschar *arg,
1354 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1355 {
1356 int sep = '/';
1357 int callout = -1;
1358 int callout_overall = -1;
1359 int callout_connect = -1;
1360 int verify_options = 0;
1361 int rc;
1362 BOOL verify_header_sender = FALSE;
1363 BOOL defer_ok = FALSE;
1364 BOOL callout_defer_ok = FALSE;
1365 BOOL no_details = FALSE;
1366 BOOL success_on_redirect = FALSE;
1367 address_item *sender_vaddr = NULL;
1368 uschar *verify_sender_address = NULL;
1369 uschar *pm_mailfrom = NULL;
1370 uschar *se_mailfrom = NULL;
1371
1372 /* Some of the verify items have slash-separated options; some do not. Diagnose
1373 an error if options are given for items that don't expect them. This code has
1374 now got very message. Refactoring to use a table would be a good idea one day.
1375 */
1376
1377 uschar *slash = Ustrchr(arg, '/');
1378 uschar *list = arg;
1379 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1380
1381 if (ss == NULL) goto BAD_VERIFY;
1382
1383 /* Handle name/address consistency verification in a separate function. */
1384
1385 if (strcmpic(ss, US"reverse_host_lookup") == 0)
1386 {
1387 if (slash != NULL) goto NO_OPTIONS;
1388 if (sender_host_address == NULL) return OK;
1389 return acl_verify_reverse(user_msgptr, log_msgptr);
1390 }
1391
1392 /* TLS certificate verification is done at STARTTLS time; here we just
1393 test whether it was successful or not. (This is for optional verification; for
1394 mandatory verification, the connection doesn't last this long.) */
1395
1396 if (strcmpic(ss, US"certificate") == 0)
1397 {
1398 if (slash != NULL) goto NO_OPTIONS;
1399 if (tls_certificate_verified) return OK;
1400 *user_msgptr = US"no verified certificate";
1401 return FAIL;
1402 }
1403
1404 /* We can test the result of optional HELO verification that might have
1405 occurred earlier. If not, we can attempt the verification now. */
1406
1407 if (strcmpic(ss, US"helo") == 0)
1408 {
1409 if (slash != NULL) goto NO_OPTIONS;
1410 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1411 return helo_verified? OK : FAIL;
1412 }
1413
1414 /* Do Client SMTP Authorization checks in a separate function, and turn the
1415 result code into user-friendly strings. */
1416
1417 if (strcmpic(ss, US"csa") == 0)
1418 {
1419 rc = acl_verify_csa(list);
1420 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1421 csa_reason_string[rc]);
1422 csa_status = csa_status_string[rc];
1423 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1424 return csa_return_code[rc];
1425 }
1426
1427 /* Check that all relevant header lines have the correct syntax. If there is
1428 a syntax error, we return details of the error to the sender if configured to
1429 send out full details. (But a "message" setting on the ACL can override, as
1430 always). */
1431
1432 if (strcmpic(ss, US"header_syntax") == 0)
1433 {
1434 if (slash != NULL) goto NO_OPTIONS;
1435 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1436 rc = verify_check_headers(log_msgptr);
1437 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1438 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1439 return rc;
1440 }
1441
1442 /* Check that no recipient of this message is "blind", that is, every envelope
1443 recipient must be mentioned in either To: or Cc:. */
1444
1445 if (strcmpic(ss, US"not_blind") == 0)
1446 {
1447 if (slash != NULL) goto NO_OPTIONS;
1448 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1449 rc = verify_check_notblind();
1450 if (rc != OK)
1451 {
1452 *log_msgptr = string_sprintf("bcc recipient detected");
1453 if (smtp_return_error_details)
1454 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1455 }
1456 return rc;
1457 }
1458
1459 /* The remaining verification tests check recipient and sender addresses,
1460 either from the envelope or from the header. There are a number of
1461 slash-separated options that are common to all of them. */
1462
1463
1464 /* Check that there is at least one verifiable sender address in the relevant
1465 header lines. This can be followed by callout and defer options, just like
1466 sender and recipient. */
1467
1468 if (strcmpic(ss, US"header_sender") == 0)
1469 {
1470 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1471 verify_header_sender = TRUE;
1472 }
1473
1474 /* Otherwise, first item in verify argument must be "sender" or "recipient".
1475 In the case of a sender, this can optionally be followed by an address to use
1476 in place of the actual sender (rare special-case requirement). */
1477
1478 else if (strncmpic(ss, US"sender", 6) == 0)
1479 {
1480 uschar *s = ss + 6;
1481 if (where > ACL_WHERE_NOTSMTP)
1482 {
1483 *log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
1484 "(only possible for MAIL, RCPT, PREDATA, or DATA)",
1485 acl_wherenames[where]);
1486 return ERROR;
1487 }
1488 if (*s == 0)
1489 verify_sender_address = sender_address;
1490 else
1491 {
1492 while (isspace(*s)) s++;
1493 if (*s++ != '=') goto BAD_VERIFY;
1494 while (isspace(*s)) s++;
1495 verify_sender_address = string_copy(s);
1496 }
1497 }
1498 else
1499 {
1500 if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
1501 if (addr == NULL)
1502 {
1503 *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
1504 "(only possible for RCPT)", acl_wherenames[where]);
1505 return ERROR;
1506 }
1507 }
1508
1509 /* Remaining items are optional; they apply to sender and recipient
1510 verification, including "header sender" verification. */
1511
1512 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1513 != NULL)
1514 {
1515 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1516 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1517 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1518
1519 /* These two old options are left for backwards compatibility */
1520
1521 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1522 {
1523 callout_defer_ok = TRUE;
1524 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1525 }
1526
1527 else if (strcmpic(ss, US"check_postmaster") == 0)
1528 {
1529 pm_mailfrom = US"";
1530 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1531 }
1532
1533 /* The callout option has a number of sub-options, comma separated */
1534
1535 else if (strncmpic(ss, US"callout", 7) == 0)
1536 {
1537 callout = CALLOUT_TIMEOUT_DEFAULT;
1538 ss += 7;
1539 if (*ss != 0)
1540 {
1541 while (isspace(*ss)) ss++;
1542 if (*ss++ == '=')
1543 {
1544 int optsep = ',';
1545 uschar *opt;
1546 uschar buffer[256];
1547 while (isspace(*ss)) ss++;
1548
1549 /* This callout option handling code has become a mess as new options
1550 have been added in an ad hoc manner. It should be tidied up into some
1551 kind of table-driven thing. */
1552
1553 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1554 != NULL)
1555 {
1556 if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
1557 else if (strcmpic(opt, US"no_cache") == 0)
1558 verify_options |= vopt_callout_no_cache;
1559 else if (strcmpic(opt, US"random") == 0)
1560 verify_options |= vopt_callout_random;
1561 else if (strcmpic(opt, US"use_sender") == 0)
1562 verify_options |= vopt_callout_recipsender;
1563 else if (strcmpic(opt, US"use_postmaster") == 0)
1564 verify_options |= vopt_callout_recippmaster;
1565 else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
1566 else if (strcmpic(opt, US"fullpostmaster") == 0)
1567 {
1568 pm_mailfrom = US"";
1569 verify_options |= vopt_callout_fullpm;
1570 }
1571
1572 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1573 {
1574 if (!verify_header_sender)
1575 {
1576 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1577 "callout option only for verify=header_sender (detected in ACL "
1578 "condition \"%s\")", arg);
1579 return ERROR;
1580 }
1581 opt += 8;
1582 while (isspace(*opt)) opt++;
1583 if (*opt++ != '=')
1584 {
1585 *log_msgptr = string_sprintf("'=' expected after "
1586 "\"mailfrom\" in ACL condition \"%s\"", arg);
1587 return ERROR;
1588 }
1589 while (isspace(*opt)) opt++;
1590 se_mailfrom = string_copy(opt);
1591 }
1592
1593 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1594 {
1595 opt += 19;
1596 while (isspace(*opt)) opt++;
1597 if (*opt++ != '=')
1598 {
1599 *log_msgptr = string_sprintf("'=' expected after "
1600 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1601 return ERROR;
1602 }
1603 while (isspace(*opt)) opt++;
1604 pm_mailfrom = string_copy(opt);
1605 }
1606
1607 else if (strncmpic(opt, US"maxwait", 7) == 0)
1608 {
1609 opt += 7;
1610 while (isspace(*opt)) opt++;
1611 if (*opt++ != '=')
1612 {
1613 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1614 "ACL condition \"%s\"", arg);
1615 return ERROR;
1616 }
1617 while (isspace(*opt)) opt++;
1618 callout_overall = readconf_readtime(opt, 0, FALSE);
1619 if (callout_overall < 0)
1620 {
1621 *log_msgptr = string_sprintf("bad time value in ACL condition "
1622 "\"verify %s\"", arg);
1623 return ERROR;
1624 }
1625 }
1626 else if (strncmpic(opt, US"connect", 7) == 0)
1627 {
1628 opt += 7;
1629 while (isspace(*opt)) opt++;
1630 if (*opt++ != '=')
1631 {
1632 *log_msgptr = string_sprintf("'=' expected after "
1633 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1634 return ERROR;
1635 }
1636 while (isspace(*opt)) opt++;
1637 callout_connect = readconf_readtime(opt, 0, FALSE);
1638 if (callout_connect < 0)
1639 {
1640 *log_msgptr = string_sprintf("bad time value in ACL condition "
1641 "\"verify %s\"", arg);
1642 return ERROR;
1643 }
1644 }
1645 else /* Plain time is callout connect/command timeout */
1646 {
1647 callout = readconf_readtime(opt, 0, FALSE);
1648 if (callout < 0)
1649 {
1650 *log_msgptr = string_sprintf("bad time value in ACL condition "
1651 "\"verify %s\"", arg);
1652 return ERROR;
1653 }
1654 }
1655 }
1656 }
1657 else
1658 {
1659 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1660 "ACL condition \"%s\"", arg);
1661 return ERROR;
1662 }
1663 }
1664 }
1665
1666 /* Option not recognized */
1667
1668 else
1669 {
1670 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1671 "condition \"verify %s\"", ss, arg);
1672 return ERROR;
1673 }
1674 }
1675
1676 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1677 (vopt_callout_recipsender|vopt_callout_recippmaster))
1678 {
1679 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1680 "for a recipient callout";
1681 return ERROR;
1682 }
1683
1684 /* Handle sender-in-header verification. Default the user message to the log
1685 message if giving out verification details. */
1686
1687 if (verify_header_sender)
1688 {
1689 int verrno;
1690 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1691 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1692 &verrno);
1693 if (rc != OK)
1694 {
1695 *basic_errno = verrno;
1696 if (smtp_return_error_details)
1697 {
1698 if (*user_msgptr == NULL && *log_msgptr != NULL)
1699 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1700 if (rc == DEFER) acl_temp_details = TRUE;
1701 }
1702 }
1703 }
1704
1705 /* Handle a sender address. The default is to verify *the* sender address, but
1706 optionally a different address can be given, for special requirements. If the
1707 address is empty, we are dealing with a bounce message that has no sender, so
1708 we cannot do any checking. If the real sender address gets rewritten during
1709 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1710 during message reception.
1711
1712 A list of verified "sender" addresses is kept to try to avoid doing to much
1713 work repetitively when there are multiple recipients in a message and they all
1714 require sender verification. However, when callouts are involved, it gets too
1715 complicated because different recipients may require different callout options.
1716 Therefore, we always do a full sender verify when any kind of callout is
1717 specified. Caching elsewhere, for instance in the DNS resolver and in the
1718 callout handling, should ensure that this is not terribly inefficient. */
1719
1720 else if (verify_sender_address != NULL)
1721 {
1722 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1723 != 0)
1724 {
1725 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1726 "sender verify callout";
1727 return ERROR;
1728 }
1729
1730 sender_vaddr = verify_checked_sender(verify_sender_address);
1731 if (sender_vaddr != NULL && /* Previously checked */
1732 callout <= 0) /* No callout needed this time */
1733 {
1734 /* If the "routed" flag is set, it means that routing worked before, so
1735 this check can give OK (the saved return code value, if set, belongs to a
1736 callout that was done previously). If the "routed" flag is not set, routing
1737 must have failed, so we use the saved return code. */
1738
1739 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1740 {
1741 rc = sender_vaddr->special_action;
1742 *basic_errno = sender_vaddr->basic_errno;
1743 }
1744 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1745 }
1746
1747 /* Do a new verification, and cache the result. The cache is used to avoid
1748 verifying the sender multiple times for multiple RCPTs when callouts are not
1749 specified (see comments above).
1750
1751 The cache is also used on failure to give details in response to the first
1752 RCPT that gets bounced for this reason. However, this can be suppressed by
1753 the no_details option, which sets the flag that says "this detail has already
1754 been sent". The cache normally contains just one address, but there may be
1755 more in esoteric circumstances. */
1756
1757 else
1758 {
1759 BOOL routed = TRUE;
1760 uschar *save_address_data = deliver_address_data;
1761
1762 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1763 if (no_details) setflag(sender_vaddr, af_sverify_told);
1764 if (verify_sender_address[0] != 0)
1765 {
1766 /* If this is the real sender address, save the unrewritten version
1767 for use later in receive. Otherwise, set a flag so that rewriting the
1768 sender in verify_address() does not update sender_address. */
1769
1770 if (verify_sender_address == sender_address)
1771 sender_address_unrewritten = sender_address;
1772 else
1773 verify_options |= vopt_fake_sender;
1774
1775 if (success_on_redirect)
1776 verify_options |= vopt_success_on_redirect;
1777
1778 /* The recipient, qualify, and expn options are never set in
1779 verify_options. */
1780
1781 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1782 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1783
1784 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1785
1786 if (rc == OK)
1787 {
1788 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1789 {
1790 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1791 verify_sender_address, sender_vaddr->address);
1792 }
1793 else
1794 {
1795 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1796 verify_sender_address);
1797 }
1798 }
1799 else *basic_errno = sender_vaddr->basic_errno;
1800 }
1801 else rc = OK; /* Null sender */
1802
1803 /* Cache the result code */
1804
1805 if (routed) setflag(sender_vaddr, af_verify_routed);
1806 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1807 sender_vaddr->special_action = rc;
1808 sender_vaddr->next = sender_verified_list;
1809 sender_verified_list = sender_vaddr;
1810
1811 /* Restore the recipient address data, which might have been clobbered by
1812 the sender verification. */
1813
1814 deliver_address_data = save_address_data;
1815 }
1816
1817 /* Put the sender address_data value into $sender_address_data */
1818
1819 sender_address_data = sender_vaddr->p.address_data;
1820 }
1821
1822 /* A recipient address just gets a straightforward verify; again we must handle
1823 the DEFER overrides. */
1824
1825 else
1826 {
1827 address_item addr2;
1828
1829 if (success_on_redirect)
1830 verify_options |= vopt_success_on_redirect;
1831
1832 /* We must use a copy of the address for verification, because it might
1833 get rewritten. */
1834
1835 addr2 = *addr;
1836 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1837 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1838 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1839
1840 *log_msgptr = addr2.message;
1841 *user_msgptr = (addr2.user_message != NULL)?
1842 addr2.user_message : addr2.message;
1843 *basic_errno = addr2.basic_errno;
1844
1845 /* Make $address_data visible */
1846 deliver_address_data = addr2.p.address_data;
1847 }
1848
1849 /* We have a result from the relevant test. Handle defer overrides first. */
1850
1851 if (rc == DEFER && (defer_ok ||
1852 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1853 {
1854 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1855 defer_ok? "defer_ok" : "callout_defer_ok");
1856 rc = OK;
1857 }
1858
1859 /* If we've failed a sender, set up a recipient message, and point
1860 sender_verified_failed to the address item that actually failed. */
1861
1862 if (rc != OK && verify_sender_address != NULL)
1863 {
1864 if (rc != DEFER)
1865 {
1866 *log_msgptr = *user_msgptr = US"Sender verify failed";
1867 }
1868 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1869 {
1870 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1871 }
1872 else
1873 {
1874 *log_msgptr = US"Could not complete sender verify callout";
1875 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
1876 *log_msgptr;
1877 }
1878
1879 sender_verified_failed = sender_vaddr;
1880 }
1881
1882 /* Verifying an address messes up the values of $domain and $local_part,
1883 so reset them before returning if this is a RCPT ACL. */
1884
1885 if (addr != NULL)
1886 {
1887 deliver_domain = addr->domain;
1888 deliver_localpart = addr->local_part;
1889 }
1890 return rc;
1891
1892 /* Syntax errors in the verify argument come here. */
1893
1894 BAD_VERIFY:
1895 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
1896 "\"helo\", \"header_syntax\", \"header_sender\" or "
1897 "\"reverse_host_lookup\" at start of ACL condition "
1898 "\"verify %s\"", arg);
1899 return ERROR;
1900
1901 /* Options supplied when not allowed come here */
1902
1903 NO_OPTIONS:
1904 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1905 "(this verify item has no options)", arg);
1906 return ERROR;
1907
1908 /* Calls in the wrong ACL come here */
1909
1910 WRONG_ACL:
1911 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
1912 "(only possible in ACL for DATA)", acl_wherenames[where]);
1913 return ERROR;
1914 }
1915
1916
1917
1918
1919 /*************************************************
1920 * Check argument for control= modifier *
1921 *************************************************/
1922
1923 /* Called from acl_check_condition() below
1924
1925 Arguments:
1926 arg the argument string for control=
1927 pptr set to point to the terminating character
1928 where which ACL we are in
1929 log_msgptr for error messages
1930
1931 Returns: CONTROL_xxx value
1932 */
1933
1934 static int
1935 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
1936 {
1937 int len;
1938 control_def *d;
1939
1940 for (d = controls_list;
1941 d < controls_list + sizeof(controls_list)/sizeof(control_def);
1942 d++)
1943 {
1944 len = Ustrlen(d->name);
1945 if (Ustrncmp(d->name, arg, len) == 0) break;
1946 }
1947
1948 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
1949 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
1950 {
1951 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
1952 return CONTROL_ERROR;
1953 }
1954
1955 *pptr = arg + len;
1956 return d->value;
1957 }
1958
1959
1960
1961 /*************************************************
1962 * Handle rate limiting *
1963 *************************************************/
1964
1965 /* Called by acl_check_condition() below to calculate the result
1966 of the ACL ratelimit condition.
1967
1968 Note that the return value might be slightly unexpected: if the
1969 sender's rate is above the limit then the result is OK. This is
1970 similar to the dnslists condition, and is so that you can write
1971 ACL clauses like: defer ratelimit = 15 / 1h
1972
1973 Arguments:
1974 arg the option string for ratelimit=
1975 log_msgptr for error messages
1976
1977 Returns: OK - Sender's rate is above limit
1978 FAIL - Sender's rate is below limit
1979 DEFER - Problem opening ratelimit database
1980 ERROR - Syntax error in options.
1981 */
1982
1983 static int
1984 acl_ratelimit(uschar *arg, uschar **log_msgptr)
1985 {
1986 double limit, period;
1987 uschar *ss, *key;
1988 int sep = '/';
1989 BOOL have_key = FALSE, leaky = FALSE, strict = FALSE;
1990 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
1991 int old_pool, rc;
1992 tree_node **anchor, *t;
1993 open_db dbblock, *dbm;
1994 dbdata_ratelimit *dbd;
1995 struct timeval tv;
1996
1997 /* Parse the first two options and record their values in expansion
1998 variables. These variables allow the configuration to have informative
1999 error messages based on rate limits obtained from a table lookup. */
2000
2001 /* First is the maximum number of messages per period and maximum burst
2002 size, which must be greater than or equal to zero. Zero is useful for
2003 rate measurement as opposed to rate limiting. */
2004
2005 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2006 if (sender_rate_limit == NULL)
2007 limit = -1.0;
2008 else
2009 {
2010 limit = Ustrtod(sender_rate_limit, &ss);
2011 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2012 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2013 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2014 }
2015 if (limit < 0.0 || *ss != 0)
2016 {
2017 *log_msgptr = string_sprintf("syntax error in argument for "
2018 "\"ratelimit\" condition: \"%s\" is not a positive number",
2019 sender_rate_limit);
2020 return ERROR;
2021 }
2022
2023 /* We use the rest of the argument list following the limit as the
2024 lookup key, because it doesn't make sense to use the same stored data
2025 if the period or options are different. */
2026
2027 key = arg;
2028
2029 /* Second is the rate measurement period and exponential smoothing time
2030 constant. This must be strictly greater than zero, because zero leads to
2031 run-time division errors. */
2032
2033 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2034 if (sender_rate_period == NULL) period = -1.0;
2035 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2036 if (period <= 0.0)
2037 {
2038 *log_msgptr = string_sprintf("syntax error in argument for "
2039 "\"ratelimit\" condition: \"%s\" is not a time value",
2040 sender_rate_period);
2041 return ERROR;
2042 }
2043
2044 /* Parse the other options. Should we check if the per_* options are being
2045 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
2046
2047 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2048 != NULL)
2049 {
2050 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2051 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2052 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
2053 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
2054 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
2055 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
2056 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
2057 else have_key = TRUE;
2058 }
2059 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
2060 {
2061 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
2062 return ERROR;
2063 }
2064
2065 /* Default option values */
2066 if (!strict) leaky = TRUE;
2067 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
2068
2069 /* If there is no explicit key, use the sender_host_address. If there is no
2070 sender_host_address (e.g. -bs or acl_not_smtp) then we simply omit it. */
2071
2072 if (!have_key && sender_host_address != NULL)
2073 key = string_sprintf("%s / %s", key, sender_host_address);
2074
2075 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2076 limit, period, key);
2077
2078 /* See if we have already computed the rate by looking in the relevant tree. For
2079 per-connection rate limiting, store tree nodes and dbdata in the permanent pool
2080 so that they survive across resets. */
2081
2082 anchor = NULL;
2083 old_pool = store_pool;
2084
2085 if (per_conn)
2086 {
2087 anchor = &ratelimiters_conn;
2088 store_pool = POOL_PERM;
2089 }
2090 else if (per_mail || per_byte)
2091 anchor = &ratelimiters_mail;
2092 else if (per_cmd)
2093 anchor = &ratelimiters_cmd;
2094
2095 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2096 {
2097 dbd = t->data.ptr;
2098 /* The following few lines duplicate some of the code below. */
2099 if (dbd->rate < limit) rc = FAIL;
2100 else rc = OK;
2101 store_pool = old_pool;
2102 sender_rate = string_sprintf("%.1f", dbd->rate);
2103 HDEBUG(D_acl)
2104 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2105 return rc;
2106 }
2107
2108 /* We aren't using a pre-computed rate, so get a previously recorded
2109 rate from the database, update it, and write it back. If there's no
2110 previous rate for this key, create one. */
2111
2112 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2113 if (dbm == NULL)
2114 {
2115 store_pool = old_pool;
2116 sender_rate = NULL;
2117 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2118 *log_msgptr = US"ratelimit database not available";
2119 return DEFER;
2120 }
2121 dbd = dbfn_read(dbm, key);
2122
2123 gettimeofday(&tv, NULL);
2124
2125 if (dbd == NULL)
2126 {
2127 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2128 dbd = store_get(sizeof(dbdata_ratelimit));
2129 dbd->time_stamp = tv.tv_sec;
2130 dbd->time_usec = tv.tv_usec;
2131 dbd->rate = 0.0;
2132 }
2133 else
2134 {
2135 /* The smoothed rate is computed using an exponentially weighted moving
2136 average adjusted for variable sampling intervals. The standard EWMA for
2137 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2138 where f() is the measured value and f'() is the smoothed value.
2139
2140 Old data decays out of the smoothed value exponentially, such that data n
2141 samples old is multiplied by a^n. The exponential decay time constant p
2142 is defined such that data p samples old is multiplied by 1/e, which means
2143 that a = exp(-1/p). We can maintain the same time constant for a variable
2144 sampling interval i by using a = exp(-i/p).
2145
2146 The rate we are measuring is messages per period, suitable for directly
2147 comparing with the limit. The average rate between now and the previous
2148 message is period / interval, which we feed into the EWMA as the sample.
2149
2150 It turns out that the number of messages required for the smoothed rate
2151 to reach the limit when they are sent in a burst is equal to the limit.
2152 This can be seen by analysing the value of the smoothed rate after N
2153 messages sent at even intervals. Let k = (1 - a) * p/i
2154
2155 rate_1 = (1 - a) * p/i + a * rate_0
2156 = k + a * rate_0
2157 rate_2 = k + a * rate_1
2158 = k + a * k + a^2 * rate_0
2159 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2160 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2161 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2162 = rate_0 * a^N + p/i * (1 - a^N)
2163
2164 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2165
2166 rate_N = p/i + (rate_0 - p/i) * a^N
2167 a^N = (rate_N - p/i) / (rate_0 - p/i)
2168 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2169 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2170
2171 Numerical analysis of the above equation, setting the computed rate to
2172 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2173 rates, p/i, the number of messages N = limit. So limit serves as both the
2174 maximum rate measured in messages per period, and the maximum number of
2175 messages that can be sent in a fast burst. */
2176
2177 double this_time = (double)tv.tv_sec
2178 + (double)tv.tv_usec / 1000000.0;
2179 double prev_time = (double)dbd->time_stamp
2180 + (double)dbd->time_usec / 1000000.0;
2181
2182 /* We must avoid division by zero, and deal gracefully with the clock going
2183 backwards. If we blunder ahead when time is in reverse then the computed
2184 rate will be bogus. To be safe we clamp interval to a very small number. */
2185
2186 double interval = this_time - prev_time <= 0.0 ? 1e-9
2187 : this_time - prev_time;
2188
2189 double i_over_p = interval / period;
2190 double a = exp(-i_over_p);
2191
2192 dbd->time_stamp = tv.tv_sec;
2193 dbd->time_usec = tv.tv_usec;
2194
2195 /* If we are measuring the rate in bytes per period, multiply the
2196 measured rate by the message size. If we don't know the message size
2197 then it's safe to just use a value of zero and let the recorded rate
2198 decay as if nothing happened. */
2199
2200 if (per_byte)
2201 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2202 * (1 - a) / i_over_p + a * dbd->rate;
2203 else
2204 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2205 }
2206
2207 /* Clients sending at the limit are considered to be over the limit. This
2208 matters for edge cases such the first message sent by a client (which gets
2209 the initial rate of 0.0) when the rate limit is zero (i.e. the client should
2210 be completely blocked). */
2211
2212 if (dbd->rate < limit) rc = FAIL;
2213 else rc = OK;
2214
2215 /* Update the state if the rate is low or if we are being strict. If we
2216 are in leaky mode and the sender's rate is too high, we do not update
2217 the recorded rate in order to avoid an over-aggressive sender's retry
2218 rate preventing them from getting any email through. */
2219
2220 if (rc == FAIL || !leaky)
2221 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2222 dbfn_close(dbm);
2223
2224 /* Store the result in the tree for future reference, if necessary. */
2225
2226 if (anchor != NULL)
2227 {
2228 t = store_get(sizeof(tree_node) + Ustrlen(key));
2229 t->data.ptr = dbd;
2230 Ustrcpy(t->name, key);
2231 (void)tree_insertnode(anchor, t);
2232 }
2233
2234 /* We create the formatted version of the sender's rate very late in
2235 order to ensure that it is done using the correct storage pool. */
2236
2237 store_pool = old_pool;
2238 sender_rate = string_sprintf("%.1f", dbd->rate);
2239
2240 HDEBUG(D_acl)
2241 debug_printf("ratelimit computed rate %s\n", sender_rate);
2242
2243 return rc;
2244 }
2245
2246
2247
2248 /*************************************************
2249 * Handle conditions/modifiers on an ACL item *
2250 *************************************************/
2251
2252 /* Called from acl_check() below.
2253
2254 Arguments:
2255 verb ACL verb
2256 cb ACL condition block - if NULL, result is OK
2257 where where called from
2258 addr the address being checked for RCPT, or NULL
2259 level the nesting level
2260 epp pointer to pass back TRUE if "endpass" encountered
2261 (applies only to "accept" and "discard")
2262 user_msgptr user message pointer
2263 log_msgptr log message pointer
2264 basic_errno pointer to where to put verify error
2265
2266 Returns: OK - all conditions are met
2267 DISCARD - an "acl" condition returned DISCARD - only allowed
2268 for "accept" or "discard" verbs
2269 FAIL - at least one condition fails
2270 FAIL_DROP - an "acl" condition returned FAIL_DROP
2271 DEFER - can't tell at the moment (typically, lookup defer,
2272 but can be temporary callout problem)
2273 ERROR - ERROR from nested ACL or expansion failure or other
2274 error
2275 */
2276
2277 static int
2278 acl_check_condition(int verb, acl_condition_block *cb, int where,
2279 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2280 uschar **log_msgptr, int *basic_errno)
2281 {
2282 uschar *user_message = NULL;
2283 uschar *log_message = NULL;
2284 uschar *p;
2285 int rc = OK;
2286 #ifdef WITH_CONTENT_SCAN
2287 int sep = '/';
2288 #endif
2289
2290 for (; cb != NULL; cb = cb->next)
2291 {
2292 uschar *arg;
2293 int control_type;
2294
2295 /* The message and log_message items set up messages to be used in
2296 case of rejection. They are expanded later. */
2297
2298 if (cb->type == ACLC_MESSAGE)
2299 {
2300 user_message = cb->arg;
2301 continue;
2302 }
2303
2304 if (cb->type == ACLC_LOG_MESSAGE)
2305 {
2306 log_message = cb->arg;
2307 continue;
2308 }
2309
2310 /* The endpass "condition" just sets a flag to show it occurred. This is
2311 checked at compile time to be on an "accept" or "discard" item. */
2312
2313 if (cb->type == ACLC_ENDPASS)
2314 {
2315 *epp = TRUE;
2316 continue;
2317 }
2318
2319 /* For other conditions and modifiers, the argument is expanded now for some
2320 of them, but not for all, because expansion happens down in some lower level
2321 checking functions in some cases. */
2322
2323 if (cond_expand_at_top[cb->type])
2324 {
2325 arg = expand_string(cb->arg);
2326 if (arg == NULL)
2327 {
2328 if (expand_string_forcedfail) continue;
2329 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2330 cb->arg, expand_string_message);
2331 return search_find_defer? DEFER : ERROR;
2332 }
2333 }
2334 else arg = cb->arg;
2335
2336 /* Show condition, and expanded condition if it's different */
2337
2338 HDEBUG(D_acl)
2339 {
2340 int lhswidth = 0;
2341 debug_printf("check %s%s %n",
2342 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2343 conditions[cb->type], &lhswidth);
2344
2345 if (cb->type == ACLC_SET)
2346 {
2347 int n = cb->u.varnumber;
2348 int t = (n < ACL_CVARS)? 'c' : 'm';
2349 if (n >= ACL_CVARS) n -= ACL_CVARS;
2350 debug_printf("acl_%c%d ", t, n);
2351 lhswidth += 7;
2352 }
2353
2354 debug_printf("= %s\n", cb->arg);
2355
2356 if (arg != cb->arg)
2357 debug_printf("%.*s= %s\n", lhswidth,
2358 US" ", CS arg);
2359 }
2360
2361 /* Check that this condition makes sense at this time */
2362
2363 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2364 {
2365 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2366 cond_modifiers[cb->type]? "use" : "test",
2367 conditions[cb->type], acl_wherenames[where]);
2368 return ERROR;
2369 }
2370
2371 /* Run the appropriate test for each condition, or take the appropriate
2372 action for the remaining modifiers. */
2373
2374 switch(cb->type)
2375 {
2376 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2377 "discard" verb. */
2378
2379 case ACLC_ACL:
2380 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2381 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2382 {
2383 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2384 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2385 verbs[verb]);
2386 return ERROR;
2387 }
2388 break;
2389
2390 case ACLC_AUTHENTICATED:
2391 rc = (sender_host_authenticated == NULL)? FAIL :
2392 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2393 TRUE, NULL);
2394 break;
2395
2396 #ifdef EXPERIMENTAL_BRIGHTMAIL
2397 case ACLC_BMI_OPTIN:
2398 {
2399 int old_pool = store_pool;
2400 store_pool = POOL_PERM;
2401 bmi_current_optin = string_copy(arg);
2402 store_pool = old_pool;
2403 }
2404 break;
2405 #endif
2406
2407 case ACLC_CONDITION:
2408 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2409 rc = (Uatoi(arg) == 0)? FAIL : OK;
2410 else
2411 rc = (strcmpic(arg, US"no") == 0 ||
2412 strcmpic(arg, US"false") == 0)? FAIL :
2413 (strcmpic(arg, US"yes") == 0 ||
2414 strcmpic(arg, US"true") == 0)? OK : DEFER;
2415 if (rc == DEFER)
2416 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2417 break;
2418
2419 case ACLC_CONTROL:
2420 control_type = decode_control(arg, &p, where, log_msgptr);
2421
2422 /* Check if this control makes sense at this time */
2423
2424 if ((control_forbids[control_type] & (1 << where)) != 0)
2425 {
2426 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2427 controls[control_type], acl_wherenames[where]);
2428 return ERROR;
2429 }
2430
2431 switch(control_type)
2432 {
2433 #ifdef EXPERIMENTAL_BRIGHTMAIL
2434 case CONTROL_BMI_RUN:
2435 bmi_run = 1;
2436 break;
2437 #endif
2438 #ifdef EXPERIMENTAL_DOMAINKEYS
2439 case CONTROL_DK_VERIFY:
2440 dk_do_verify = 1;
2441 break;
2442 #endif
2443 case CONTROL_ERROR:
2444 return ERROR;
2445
2446 case CONTROL_CASEFUL_LOCAL_PART:
2447 deliver_localpart = addr->cc_local_part;
2448 break;
2449
2450 case CONTROL_CASELOWER_LOCAL_PART:
2451 deliver_localpart = addr->lc_local_part;
2452 break;
2453
2454 case CONTROL_ENFORCE_SYNC:
2455 smtp_enforce_sync = TRUE;
2456 break;
2457
2458 case CONTROL_NO_ENFORCE_SYNC:
2459 smtp_enforce_sync = FALSE;
2460 break;
2461
2462 #ifdef WITH_CONTENT_SCAN
2463 case CONTROL_NO_MBOX_UNSPOOL:
2464 no_mbox_unspool = TRUE;
2465 break;
2466 #endif
2467
2468 case CONTROL_NO_MULTILINE:
2469 no_multiline_responses = TRUE;
2470 break;
2471
2472 case CONTROL_FAKEDEFER:
2473 case CONTROL_FAKEREJECT:
2474 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2475 if (*p == '/')
2476 {
2477 uschar *pp = p + 1;
2478 while (*pp != 0) pp++;
2479 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2480 p = pp;
2481 }
2482 else
2483 {
2484 /* Explicitly reset to default string */
2485 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).";
2486 }
2487 break;
2488
2489 case CONTROL_FREEZE:
2490 deliver_freeze = TRUE;
2491 deliver_frozen_at = time(NULL);
2492 break;
2493
2494 case CONTROL_QUEUE_ONLY:
2495 queue_only_policy = TRUE;
2496 break;
2497
2498 case CONTROL_SUBMISSION:
2499 originator_name = US"";
2500 submission_mode = TRUE;
2501 while (*p == '/')
2502 {
2503 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2504 {
2505 p += 14;
2506 active_local_sender_retain = TRUE;
2507 active_local_from_check = FALSE;
2508 }
2509 else if (Ustrncmp(p, "/domain=", 8) == 0)
2510 {
2511 uschar *pp = p + 8;
2512 while (*pp != 0 && *pp != '/') pp++;
2513 submission_domain = string_copyn(p+8, pp-p-8);
2514 p = pp;
2515 }
2516 /* The name= option must be last, because it swallows the rest of
2517 the string. */
2518 else if (Ustrncmp(p, "/name=", 6) == 0)
2519 {
2520 uschar *pp = p + 6;
2521 while (*pp != 0) pp++;
2522 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2523 big_buffer, big_buffer_size));
2524 p = pp;
2525 }
2526 else break;
2527 }
2528 if (*p != 0)
2529 {
2530 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2531 return ERROR;
2532 }
2533 break;
2534
2535 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
2536 suppress_local_fixups = TRUE;
2537 break;
2538 }
2539 break;
2540
2541 #ifdef WITH_CONTENT_SCAN
2542 case ACLC_DECODE:
2543 rc = mime_decode(&arg);
2544 break;
2545 #endif
2546
2547 case ACLC_DELAY:
2548 {
2549 int delay = readconf_readtime(arg, 0, FALSE);
2550 if (delay < 0)
2551 {
2552 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2553 "modifier: \"%s\" is not a time value", arg);
2554 return ERROR;
2555 }
2556 else
2557 {
2558 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2559 delay);
2560 if (host_checking)
2561 {
2562 HDEBUG(D_acl)
2563 debug_printf("delay skipped in -bh checking mode\n");
2564 }
2565
2566 /* It appears to be impossible to detect that a TCP/IP connection has
2567 gone away without reading from it. This means that we cannot shorten
2568 the delay below if the client goes away, because we cannot discover
2569 that the client has closed its end of the connection. (The connection
2570 is actually in a half-closed state, waiting for the server to close its
2571 end.) It would be nice to be able to detect this state, so that the
2572 Exim process is not held up unnecessarily. However, it seems that we
2573 can't. The poll() function does not do the right thing, and in any case
2574 it is not always available.
2575
2576 NOTE: If ever this state of affairs changes, remember that we may be
2577 dealing with stdin/stdout here, in addition to TCP/IP connections.
2578 Whatever is done must work in both cases. To detected the stdin/stdout
2579 case, check for smtp_in or smtp_out being NULL. */
2580
2581 else
2582 {
2583 while (delay > 0) delay = sleep(delay);
2584 }
2585 }
2586 }
2587 break;
2588
2589 #ifdef WITH_OLD_DEMIME
2590 case ACLC_DEMIME:
2591 rc = demime(&arg);
2592 break;
2593 #endif
2594
2595 #ifdef EXPERIMENTAL_DOMAINKEYS
2596 case ACLC_DK_DOMAIN_SOURCE:
2597 if (dk_verify_block == NULL) { rc = FAIL; break; };
2598 /* check header source of domain against given string */
2599 switch (dk_verify_block->address_source) {
2600 case DK_EXIM_ADDRESS_FROM_FROM:
2601 rc = match_isinlist(US"from", &arg, 0, NULL,
2602 NULL, MCL_STRING, TRUE, NULL);
2603 break;
2604 case DK_EXIM_ADDRESS_FROM_SENDER:
2605 rc = match_isinlist(US"sender", &arg, 0, NULL,
2606 NULL, MCL_STRING, TRUE, NULL);
2607 break;
2608 case DK_EXIM_ADDRESS_NONE:
2609 rc = match_isinlist(US"none", &arg, 0, NULL,
2610 NULL, MCL_STRING, TRUE, NULL);
2611 break;
2612 }
2613 break;
2614 case ACLC_DK_POLICY:
2615 if (dk_verify_block == NULL) { rc = FAIL; break; };
2616 /* check policy against given string, default FAIL */
2617 rc = FAIL;
2618 if (dk_verify_block->signsall)
2619 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2620 NULL, MCL_STRING, TRUE, NULL);
2621 if (dk_verify_block->testing)
2622 rc = match_isinlist(US"testing", &arg, 0, NULL,
2623 NULL, MCL_STRING, TRUE, NULL);
2624 break;
2625 case ACLC_DK_SENDER_DOMAINS:
2626 if (dk_verify_block == NULL) { rc = FAIL; break; };
2627 if (dk_verify_block->domain != NULL)
2628 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2629 NULL, MCL_DOMAIN, TRUE, NULL);
2630 else rc = FAIL;
2631 break;
2632 case ACLC_DK_SENDER_LOCAL_PARTS:
2633 if (dk_verify_block == NULL) { rc = FAIL; break; };
2634 if (dk_verify_block->local_part != NULL)
2635 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2636 NULL, MCL_LOCALPART, TRUE, NULL);
2637 else rc = FAIL;
2638 break;
2639 case ACLC_DK_SENDERS:
2640 if (dk_verify_block == NULL) { rc = FAIL; break; };
2641 if (dk_verify_block->address != NULL)
2642 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2643 else rc = FAIL;
2644 break;
2645 case ACLC_DK_STATUS:
2646 if (dk_verify_block == NULL) { rc = FAIL; break; };
2647 if (dk_verify_block->result > 0) {
2648 switch(dk_verify_block->result) {
2649 case DK_EXIM_RESULT_BAD_FORMAT:
2650 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2651 NULL, MCL_STRING, TRUE, NULL);
2652 break;
2653 case DK_EXIM_RESULT_NO_KEY:
2654 rc = match_isinlist(US"no key", &arg, 0, NULL,
2655 NULL, MCL_STRING, TRUE, NULL);
2656 break;
2657 case DK_EXIM_RESULT_NO_SIGNATURE:
2658 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2659 NULL, MCL_STRING, TRUE, NULL);
2660 break;
2661 case DK_EXIM_RESULT_REVOKED:
2662 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2663 NULL, MCL_STRING, TRUE, NULL);
2664 break;
2665 case DK_EXIM_RESULT_NON_PARTICIPANT:
2666 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2667 NULL, MCL_STRING, TRUE, NULL);
2668 break;
2669 case DK_EXIM_RESULT_GOOD:
2670 rc = match_isinlist(US"good", &arg, 0, NULL,
2671 NULL, MCL_STRING, TRUE, NULL);
2672 break;
2673 case DK_EXIM_RESULT_BAD:
2674 rc = match_isinlist(US"bad", &arg, 0, NULL,
2675 NULL, MCL_STRING, TRUE, NULL);
2676 break;
2677 }
2678 }
2679 break;
2680 #endif
2681
2682 case ACLC_DNSLISTS:
2683 rc = verify_check_dnsbl(&arg);
2684 break;
2685
2686 case ACLC_DOMAINS:
2687 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2688 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2689 break;
2690
2691 /* The value in tls_cipher is the full cipher name, for example,
2692 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2693 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2694 what may in practice come out of the SSL library - which at the time of
2695 writing is poorly documented. */
2696
2697 case ACLC_ENCRYPTED:
2698 if (tls_cipher == NULL) rc = FAIL; else
2699 {
2700 uschar *endcipher = NULL;
2701 uschar *cipher = Ustrchr(tls_cipher, ':');
2702 if (cipher == NULL) cipher = tls_cipher; else
2703 {
2704 endcipher = Ustrchr(++cipher, ':');
2705 if (endcipher != NULL) *endcipher = 0;
2706 }
2707 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2708 if (endcipher != NULL) *endcipher = ':';
2709 }
2710 break;
2711
2712 /* Use verify_check_this_host() instead of verify_check_host() so that
2713 we can pass over &host_data to catch any looked up data. Once it has been
2714 set, it retains its value so that it's still there if another ACL verb
2715 comes through here and uses the cache. However, we must put it into
2716 permanent store in case it is also expected to be used in a subsequent
2717 message in the same SMTP connection. */
2718
2719 case ACLC_HOSTS:
2720 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2721 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2722 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2723 break;
2724
2725 case ACLC_LOCAL_PARTS:
2726 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2727 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2728 &deliver_localpart_data);
2729 break;
2730
2731 case ACLC_LOGWRITE:
2732 {
2733 int logbits = 0;
2734 uschar *s = arg;
2735 if (*s == ':')
2736 {
2737 s++;
2738 while (*s != ':')
2739 {
2740 if (Ustrncmp(s, "main", 4) == 0)
2741 { logbits |= LOG_MAIN; s += 4; }
2742 else if (Ustrncmp(s, "panic", 5) == 0)
2743 { logbits |= LOG_PANIC; s += 5; }
2744 else if (Ustrncmp(s, "reject", 6) == 0)
2745 { logbits |= LOG_REJECT; s += 6; }
2746 else
2747 {
2748 logbits = LOG_MAIN|LOG_PANIC;
2749 s = string_sprintf(":unknown log name in \"%s\" in "
2750 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2751 }
2752 if (*s == ',') s++;
2753 }
2754 s++;
2755 }
2756 while (isspace(*s)) s++;
2757 if (logbits == 0) logbits = LOG_MAIN;
2758 log_write(0, logbits, "%s", string_printing(s));
2759 }
2760 break;
2761
2762 #ifdef WITH_CONTENT_SCAN
2763 case ACLC_MALWARE:
2764 {
2765 /* Seperate the regular expression and any optional parameters. */
2766 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2767 /* Run the malware backend. */
2768 rc = malware(&ss);
2769 /* Modify return code based upon the existance of options. */
2770 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2771 != NULL) {
2772 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2773 {
2774 /* FAIL so that the message is passed to the next ACL */
2775 rc = FAIL;
2776 }
2777 }
2778 }
2779 break;
2780
2781 case ACLC_MIME_REGEX:
2782 rc = mime_regex(&arg);
2783 break;
2784 #endif
2785
2786 case ACLC_RATELIMIT:
2787 rc = acl_ratelimit(arg, log_msgptr);
2788 break;
2789
2790 case ACLC_RECIPIENTS:
2791 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
2792 &recipient_data);
2793 break;
2794
2795 #ifdef WITH_CONTENT_SCAN
2796 case ACLC_REGEX:
2797 rc = regex(&arg);
2798 break;
2799 #endif
2800
2801 case ACLC_SENDER_DOMAINS:
2802 {
2803 uschar *sdomain;
2804 sdomain = Ustrrchr(sender_address, '@');
2805 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
2806 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
2807 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
2808 }
2809 break;
2810
2811 case ACLC_SENDERS:
2812 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
2813 sender_address_cache, -1, 0, &sender_data);
2814 break;
2815
2816 /* Connection variables must persist forever */
2817
2818 case ACLC_SET:
2819 {
2820 int old_pool = store_pool;
2821 if (cb->u.varnumber < ACL_CVARS) store_pool = POOL_PERM;
2822 acl_var[cb->u.varnumber] = string_copy(arg);
2823 store_pool = old_pool;
2824 }
2825 break;
2826
2827 #ifdef WITH_CONTENT_SCAN
2828 case ACLC_SPAM:
2829 {
2830 /* Seperate the regular expression and any optional parameters. */
2831 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2832 /* Run the spam backend. */
2833 rc = spam(&ss);
2834 /* Modify return code based upon the existance of options. */
2835 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2836 != NULL) {
2837 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
2838 {
2839 /* FAIL so that the message is passed to the next ACL */
2840 rc = FAIL;
2841 }
2842 }
2843 }
2844 break;
2845 #endif
2846
2847 #ifdef EXPERIMENTAL_SPF
2848 case ACLC_SPF:
2849 rc = spf_process(&arg, sender_address);
2850 break;
2851 #endif
2852
2853 /* If the verb is WARN, discard any user message from verification, because
2854 such messages are SMTP responses, not header additions. The latter come
2855 only from explicit "message" modifiers. However, put the user message into
2856 $acl_verify_message so it can be used in subsequent conditions or modifiers
2857 (until something changes it). */
2858
2859 case ACLC_VERIFY:
2860 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
2861 acl_verify_message = *user_msgptr;
2862 if (verb == ACL_WARN) *user_msgptr = NULL;
2863 break;
2864
2865 default:
2866 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
2867 "condition %d", cb->type);
2868 break;
2869 }
2870
2871 /* If a condition was negated, invert OK/FAIL. */
2872
2873 if (!cond_modifiers[cb->type] && cb->u.negated)
2874 {
2875 if (rc == OK) rc = FAIL;
2876 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
2877 }
2878
2879 if (rc != OK) break; /* Conditions loop */
2880 }
2881
2882
2883 /* If the result is the one for which "message" and/or "log_message" are used,
2884 handle the values of these options. Most verbs have but a single return for
2885 which the messages are relevant, but for "discard", it's useful to have the log
2886 message both when it succeeds and when it fails. Also, for an "accept" that
2887 appears in a QUIT ACL, we want to handle the user message. Since only "accept"
2888 and "warn" are permitted in that ACL, we don't need to test the verb.
2889
2890 These modifiers act in different ways:
2891
2892 "message" is a user message that will be included in an SMTP response. Unless
2893 it is empty, it overrides any previously set user message.
2894
2895 "log_message" is a non-user message, and it adds to any existing non-user
2896 message that is already set.
2897
2898 If there isn't a log message set, we make it the same as the user message. */
2899
2900 if (((rc == FAIL_DROP)? FAIL : rc) == msgcond[verb] ||
2901 (verb == ACL_DISCARD && rc == OK) ||
2902 (where == ACL_WHERE_QUIT))
2903 {
2904 uschar *expmessage;
2905
2906 /* If the verb is "warn", messages generated by conditions (verification or
2907 nested ACLs) are discarded. Only messages specified at this level are used.
2908 However, the value of an existing message is available in $acl_verify_message
2909 during expansions. */
2910
2911 uschar *old_user_msgptr = *user_msgptr;
2912 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
2913
2914 if (verb == ACL_WARN) *log_msgptr = *user_msgptr = NULL;
2915
2916 if (user_message != NULL)
2917 {
2918 acl_verify_message = old_user_msgptr;
2919 expmessage = expand_string(user_message);
2920 if (expmessage == NULL)
2921 {
2922 if (!expand_string_forcedfail)
2923 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2924 user_message, expand_string_message);
2925 }
2926 else if (expmessage[0] != 0) *user_msgptr = expmessage;
2927 }
2928
2929 if (log_message != NULL)
2930 {
2931 acl_verify_message = old_log_msgptr;
2932 expmessage = expand_string(log_message);
2933 if (expmessage == NULL)
2934 {
2935 if (!expand_string_forcedfail)
2936 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
2937 log_message, expand_string_message);
2938 }
2939 else if (expmessage[0] != 0)
2940 {
2941 *log_msgptr = (*log_msgptr == NULL)? expmessage :
2942 string_sprintf("%s: %s", expmessage, *log_msgptr);
2943 }
2944 }
2945
2946 /* If no log message, default it to the user message */
2947
2948 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
2949 }
2950
2951 acl_verify_message = NULL;
2952 return rc;
2953 }
2954
2955
2956
2957
2958
2959 /*************************************************
2960 * Get line from a literal ACL *
2961 *************************************************/
2962
2963 /* This function is passed to acl_read() in order to extract individual lines
2964 of a literal ACL, which we access via static pointers. We can destroy the
2965 contents because this is called only once (the compiled ACL is remembered).
2966
2967 This code is intended to treat the data in the same way as lines in the main
2968 Exim configuration file. That is:
2969
2970 . Leading spaces are ignored.
2971
2972 . A \ at the end of a line is a continuation - trailing spaces after the \
2973 are permitted (this is because I don't believe in making invisible things
2974 significant). Leading spaces on the continued part of a line are ignored.
2975
2976 . Physical lines starting (significantly) with # are totally ignored, and
2977 may appear within a sequence of backslash-continued lines.
2978
2979 . Blank lines are ignored, but will end a sequence of continuations.
2980
2981 Arguments: none
2982 Returns: a pointer to the next line
2983 */
2984
2985
2986 static uschar *acl_text; /* Current pointer in the text */
2987 static uschar *acl_text_end; /* Points one past the terminating '0' */
2988
2989
2990 static uschar *
2991 acl_getline(void)
2992 {
2993 uschar *yield;
2994
2995 /* This loop handles leading blank lines and comments. */
2996
2997 for(;;)
2998 {
2999 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3000 if (*acl_text == 0) return NULL; /* No more data */
3001 yield = acl_text; /* Potential data line */
3002
3003 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3004
3005 /* If we hit the end before a newline, we have the whole logical line. If
3006 it's a comment, there's no more data to be given. Otherwise, yield it. */
3007
3008 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3009
3010 /* After reaching a newline, end this loop if the physical line does not
3011 start with '#'. If it does, it's a comment, and the loop continues. */
3012
3013 if (*yield != '#') break;
3014 }
3015
3016 /* This loop handles continuations. We know we have some real data, ending in
3017 newline. See if there is a continuation marker at the end (ignoring trailing
3018 white space). We know that *yield is not white space, so no need to test for
3019 cont > yield in the backwards scanning loop. */
3020
3021 for(;;)
3022 {
3023 uschar *cont;
3024 for (cont = acl_text - 1; isspace(*cont); cont--);
3025
3026 /* If no continuation follows, we are done. Mark the end of the line and
3027 return it. */
3028
3029 if (*cont != '\\')
3030 {
3031 *acl_text++ = 0;
3032 return yield;
3033 }
3034
3035 /* We have encountered a continuation. Skip over whitespace at the start of
3036 the next line, and indeed the whole of the next line or lines if they are
3037 comment lines. */
3038
3039 for (;;)
3040 {
3041 while (*(++acl_text) == ' ' || *acl_text == '\t');
3042 if (*acl_text != '#') break;
3043 while (*(++acl_text) != 0 && *acl_text != '\n');
3044 }
3045
3046 /* We have the start of a continuation line. Move all the rest of the data
3047 to join onto the previous line, and then find its end. If the end is not a
3048 newline, we are done. Otherwise loop to look for another continuation. */
3049
3050 memmove(cont, acl_text, acl_text_end - acl_text);
3051 acl_text_end -= acl_text - cont;
3052 acl_text = cont;
3053 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3054 if (*acl_text == 0) return yield;
3055 }
3056
3057 /* Control does not reach here */
3058 }
3059
3060
3061
3062
3063
3064 /*************************************************
3065 * Check access using an ACL *
3066 *************************************************/
3067
3068 /* This function is called from address_check. It may recurse via
3069 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3070 passed as a string which is expanded. A forced failure implies no access check
3071 is required. If the result is a single word, it is taken as the name of an ACL
3072 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3073 text, complete with newlines, and parsed as such. In both cases, the ACL check
3074 is then run. This function uses an auxiliary function for acl_read() to call
3075 for reading individual lines of a literal ACL. This is acl_getline(), which
3076 appears immediately above.
3077
3078 Arguments:
3079 where where called from
3080 addr address item when called from RCPT; otherwise NULL
3081 s the input string; NULL is the same as an empty ACL => DENY
3082 level the nesting level
3083 user_msgptr where to put a user error (for SMTP response)
3084 log_msgptr where to put a logging message (not for SMTP response)
3085
3086 Returns: OK access is granted
3087 DISCARD access is apparently granted...
3088 FAIL access is denied
3089 FAIL_DROP access is denied; drop the connection
3090 DEFER can't tell at the moment
3091 ERROR disaster
3092 */
3093
3094 static int
3095 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3096 uschar **user_msgptr, uschar **log_msgptr)
3097 {
3098 int fd = -1;
3099 acl_block *acl = NULL;
3100 uschar *acl_name = US"inline ACL";
3101 uschar *ss;
3102
3103 /* Catch configuration loops */
3104
3105 if (level > 20)
3106 {
3107 *log_msgptr = US"ACL nested too deep: possible loop";
3108 return ERROR;
3109 }
3110
3111 if (s == NULL)
3112 {
3113 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3114 return FAIL;
3115 }
3116
3117 /* At top level, we expand the incoming string. At lower levels, it has already
3118 been expanded as part of condition processing. */
3119
3120 if (level == 0)
3121 {
3122 ss = expand_string(s);
3123 if (ss == NULL)
3124 {
3125 if (expand_string_forcedfail) return OK;
3126 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3127 expand_string_message);
3128 return ERROR;
3129 }
3130 }
3131 else ss = s;
3132
3133 while (isspace(*ss))ss++;
3134
3135 /* If we can't find a named ACL, the default is to parse it as an inline one.
3136 (Unless it begins with a slash; non-existent files give rise to an error.) */
3137
3138 acl_text = ss;
3139
3140 /* Handle the case of a string that does not contain any spaces. Look for a
3141 named ACL among those read from the configuration, or a previously read file.
3142 It is possible that the pointer to the ACL is NULL if the configuration
3143 contains a name with no data. If not found, and the text begins with '/',
3144 read an ACL from a file, and save it so it can be re-used. */
3145
3146 if (Ustrchr(ss, ' ') == NULL)
3147 {
3148 tree_node *t = tree_search(acl_anchor, ss);
3149 if (t != NULL)
3150 {
3151 acl = (acl_block *)(t->data.ptr);
3152 if (acl == NULL)
3153 {
3154 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3155 return FAIL;
3156 }
3157 acl_name = string_sprintf("ACL \"%s\"", ss);
3158 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3159 }
3160
3161 else if (*ss == '/')
3162 {
3163 struct stat statbuf;
3164 fd = Uopen(ss, O_RDONLY, 0);
3165 if (fd < 0)
3166 {
3167 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3168 strerror(errno));
3169 return ERROR;
3170 }
3171
3172 if (fstat(fd, &statbuf) != 0)
3173 {
3174 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3175 strerror(errno));
3176 return ERROR;
3177 }
3178
3179 acl_text = store_get(statbuf.st_size + 1);
3180 acl_text_end = acl_text + statbuf.st_size + 1;
3181
3182 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3183 {
3184 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3185 ss, strerror(errno));
3186 return ERROR;
3187 }
3188 acl_text[statbuf.st_size] = 0;
3189 (void)close(fd);
3190
3191 acl_name = string_sprintf("ACL \"%s\"", ss);
3192 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3193 }
3194 }
3195
3196 /* Parse an ACL that is still in text form. If it came from a file, remember it
3197 in the ACL tree, having read it into the POOL_PERM store pool so that it
3198 persists between multiple messages. */
3199
3200 if (acl == NULL)
3201 {
3202 int old_pool = store_pool;
3203 if (fd >= 0) store_pool = POOL_PERM;
3204 acl = acl_read(acl_getline, log_msgptr);
3205 store_pool = old_pool;
3206 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3207 if (fd >= 0)
3208 {
3209 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3210 Ustrcpy(t->name, ss);
3211 t->data.ptr = acl;
3212 (void)tree_insertnode(&acl_anchor, t);
3213 }
3214 }
3215
3216 /* Now we have an ACL to use. It's possible it may be NULL. */
3217
3218 while (acl != NULL)
3219 {
3220 int cond;
3221 int basic_errno = 0;
3222 BOOL endpass_seen = FALSE;
3223
3224 *log_msgptr = *user_msgptr = NULL;
3225 acl_temp_details = FALSE;
3226
3227 if (where == ACL_WHERE_QUIT &&
3228 acl->verb != ACL_ACCEPT &&
3229 acl->verb != ACL_WARN)
3230 {
3231 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3232 verbs[acl->verb]);
3233 return ERROR;
3234 }
3235
3236 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3237
3238 /* Clear out any search error message from a previous check before testing
3239 this condition. */
3240
3241 search_error_message = NULL;
3242 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3243 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3244
3245 /* Handle special returns: DEFER causes a return except on a WARN verb;
3246 ERROR always causes a return. */
3247
3248 switch (cond)
3249 {
3250 case DEFER:
3251 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3252 if (basic_errno != ERRNO_CALLOUTDEFER)
3253 {
3254 if (search_error_message != NULL && *search_error_message != 0)
3255 *log_msgptr = search_error_message;
3256 if (smtp_return_error_details) acl_temp_details = TRUE;
3257 }
3258 else
3259 {
3260 acl_temp_details = TRUE;
3261 }
3262 if (acl->verb != ACL_WARN) return DEFER;
3263 break;
3264
3265 default: /* Paranoia */
3266 case ERROR:
3267 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3268 return ERROR;
3269
3270 case OK:
3271 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3272 verbs[acl->verb]);
3273 break;
3274
3275 case FAIL:
3276 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3277 break;
3278
3279 /* DISCARD and DROP can happen only from a nested ACL condition, and
3280 DISCARD can happen only for an "accept" or "discard" verb. */
3281
3282 case DISCARD:
3283 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3284 verbs[acl->verb]);
3285 break;
3286
3287 case FAIL_DROP:
3288 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3289 verbs[acl->verb]);
3290 break;
3291 }
3292
3293 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3294 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3295 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3296
3297 switch(acl->verb)
3298 {
3299 case ACL_ACCEPT:
3300 if (cond == OK || cond == DISCARD) return cond;
3301 if (endpass_seen)
3302 {
3303 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3304 return cond;
3305 }
3306 break;
3307
3308 case ACL_DEFER:
3309 if (cond == OK)
3310 {
3311 acl_temp_details = TRUE;
3312 return DEFER;
3313 }
3314 break;
3315
3316 case ACL_DENY:
3317 if (cond == OK) return FAIL;
3318 break;
3319
3320 case ACL_DISCARD:
3321 if (cond == OK || cond == DISCARD) return DISCARD;
3322 if (endpass_seen)
3323 {
3324 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3325 return cond;
3326 }
3327 break;
3328
3329 case ACL_DROP:
3330 if (cond == OK) return FAIL_DROP;
3331 break;
3332
3333 case ACL_REQUIRE:
3334 if (cond != OK) return cond;
3335 break;
3336
3337 case ACL_WARN:
3338 if (cond == OK)
3339 acl_warn(where, *user_msgptr, *log_msgptr);
3340 else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
3341 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3342 "condition test deferred%s%s", host_and_ident(TRUE),
3343 (*log_msgptr == NULL)? US"" : US": ",
3344 (*log_msgptr == NULL)? US"" : *log_msgptr);
3345 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3346 break;
3347
3348 default:
3349 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3350 acl->verb);
3351 break;
3352 }
3353
3354 /* Pass to the next ACL item */
3355
3356 acl = acl->next;
3357 }
3358
3359 /* We have reached the end of the ACL. This is an implicit DENY. */
3360
3361 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3362 return FAIL;
3363 }
3364
3365
3366 /*************************************************
3367 * Check access using an ACL *
3368 *************************************************/
3369
3370 /* This is the external interface for ACL checks. It sets up an address and the
3371 expansions for $domain and $local_part when called after RCPT, then calls
3372 acl_check_internal() to do the actual work.
3373
3374 Arguments:
3375 where ACL_WHERE_xxxx indicating where called from
3376 recipient RCPT address for RCPT check, else NULL
3377 s the input string; NULL is the same as an empty ACL => DENY
3378 user_msgptr where to put a user error (for SMTP response)
3379 log_msgptr where to put a logging message (not for SMTP response)
3380
3381 Returns: OK access is granted by an ACCEPT verb
3382 DISCARD access is granted by a DISCARD verb
3383 FAIL access is denied
3384 FAIL_DROP access is denied; drop the connection
3385 DEFER can't tell at the moment
3386 ERROR disaster
3387 */
3388
3389 int
3390 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
3391 uschar **log_msgptr)
3392 {
3393 int rc;
3394 address_item adb;
3395 address_item *addr = NULL;
3396
3397 *user_msgptr = *log_msgptr = NULL;
3398 sender_verified_failed = NULL;
3399 ratelimiters_cmd = NULL;
3400
3401 if (where == ACL_WHERE_RCPT)
3402 {
3403 adb = address_defaults;
3404 addr = &adb;
3405 addr->address = recipient;
3406 if (deliver_split_address(addr) == DEFER)
3407 {
3408 *log_msgptr = US"defer in percent_hack_domains check";
3409 return DEFER;
3410 }
3411 deliver_domain = addr->domain;
3412 deliver_localpart = addr->local_part;
3413 }
3414
3415 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3416
3417 deliver_domain = deliver_localpart = deliver_address_data =
3418 sender_address_data = NULL;
3419
3420 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3421 ACL, which is really in the middle of an SMTP command. */
3422
3423 if (rc == DISCARD)
3424 {
3425 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3426 {
3427 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3428 "ACL", acl_wherenames[where]);
3429 return ERROR;
3430 }
3431 return DISCARD;
3432 }
3433
3434 /* A DROP response is not permitted from MAILAUTH */
3435
3436 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3437 {
3438 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3439 "ACL", acl_wherenames[where]);
3440 return ERROR;
3441 }
3442
3443 /* Before giving an error response, take a look at the length of any user
3444 message, and split it up into multiple lines if possible. */
3445
3446 if (rc != OK && *user_msgptr != NULL && Ustrlen(*user_msgptr) > 75)
3447 {
3448 uschar *s = *user_msgptr = string_copy(*user_msgptr);
3449 uschar *ss = s;
3450
3451 for (;;)
3452 {
3453 int i = 0;
3454 while (i < 75 && *ss != 0 && *ss != '\n') ss++, i++;
3455 if (*ss == 0) break;
3456 if (*ss == '\n')
3457 s = ++ss;
3458 else
3459 {
3460 uschar *t = ss + 1;
3461 uschar *tt = NULL;
3462 while (--t > s + 35)
3463 {
3464 if (*t == ' ')
3465 {
3466 if (t[-1] == ':') { tt = t; break; }
3467 if (tt == NULL) tt = t;
3468 }
3469 }
3470
3471 if (tt == NULL) /* Can't split behind - try ahead */
3472 {
3473 t = ss + 1;
3474 while (*t != 0)
3475 {
3476 if (*t == ' ' || *t == '\n')
3477 { tt = t; break; }
3478 t++;
3479 }
3480 }
3481
3482 if (tt == NULL) break; /* Can't find anywhere to split */
3483 *tt = '\n';
3484 s = ss = tt+1;
3485 }
3486 }
3487 }
3488
3489 return rc;
3490 }
3491
3492 /* End of acl.c */