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Ensure that recipient is well-defined for expansion-called acl at RCPT-time.
[exim.git] / src / src / acl.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2012 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Code for handling Access Control Lists (ACLs) */
9
10 #include "exim.h"
11
12
13 /* Default callout timeout */
14
15 #define CALLOUT_TIMEOUT_DEFAULT 30
16
17 /* ACL verb codes - keep in step with the table of verbs that follows */
18
19 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
20 ACL_WARN };
21
22 /* ACL verbs */
23
24 static uschar *verbs[] =
25 { US"accept", US"defer", US"deny", US"discard", US"drop", US"require",
26 US"warn" };
27
28 /* For each verb, the conditions for which "message" or "log_message" are used
29 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
30 "accept", the FAIL case is used only after "endpass", but that is selected in
31 the code. */
32
33 static int msgcond[] = {
34 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
35 (1<<OK), /* defer */
36 (1<<OK), /* deny */
37 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
38 (1<<OK), /* drop */
39 (1<<FAIL) | (1<<FAIL_DROP), /* require */
40 (1<<OK) /* warn */
41 };
42
43 /* ACL condition and modifier codes - keep in step with the table that
44 follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
45 down. */
46
47 enum { ACLC_ACL,
48 ACLC_ADD_HEADER,
49 ACLC_AUTHENTICATED,
50 #ifdef EXPERIMENTAL_BRIGHTMAIL
51 ACLC_BMI_OPTIN,
52 #endif
53 ACLC_CONDITION,
54 ACLC_CONTINUE,
55 ACLC_CONTROL,
56 #ifdef EXPERIMENTAL_DCC
57 ACLC_DCC,
58 #endif
59 #ifdef WITH_CONTENT_SCAN
60 ACLC_DECODE,
61 #endif
62 ACLC_DELAY,
63 #ifdef WITH_OLD_DEMIME
64 ACLC_DEMIME,
65 #endif
66 #ifndef DISABLE_DKIM
67 ACLC_DKIM_SIGNER,
68 ACLC_DKIM_STATUS,
69 #endif
70 ACLC_DNSLISTS,
71 ACLC_DOMAINS,
72 ACLC_ENCRYPTED,
73 ACLC_ENDPASS,
74 ACLC_HOSTS,
75 ACLC_LOCAL_PARTS,
76 ACLC_LOG_MESSAGE,
77 ACLC_LOG_REJECT_TARGET,
78 ACLC_LOGWRITE,
79 #ifdef WITH_CONTENT_SCAN
80 ACLC_MALWARE,
81 #endif
82 ACLC_MESSAGE,
83 #ifdef WITH_CONTENT_SCAN
84 ACLC_MIME_REGEX,
85 #endif
86 ACLC_RATELIMIT,
87 ACLC_RECIPIENTS,
88 #ifdef WITH_CONTENT_SCAN
89 ACLC_REGEX,
90 #endif
91 ACLC_REMOVE_HEADER,
92 ACLC_SENDER_DOMAINS,
93 ACLC_SENDERS,
94 ACLC_SET,
95 #ifdef WITH_CONTENT_SCAN
96 ACLC_SPAM,
97 #endif
98 #ifdef EXPERIMENTAL_SPF
99 ACLC_SPF,
100 ACLC_SPF_GUESS,
101 #endif
102 ACLC_VERIFY };
103
104 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
105 "message", "log_message", "log_reject_target", "logwrite", and "set" are
106 modifiers that look like conditions but always return TRUE. They are used for
107 their side effects. */
108
109 static uschar *conditions[] = {
110 US"acl",
111 US"add_header",
112 US"authenticated",
113 #ifdef EXPERIMENTAL_BRIGHTMAIL
114 US"bmi_optin",
115 #endif
116 US"condition",
117 US"continue",
118 US"control",
119 #ifdef EXPERIMENTAL_DCC
120 US"dcc",
121 #endif
122 #ifdef WITH_CONTENT_SCAN
123 US"decode",
124 #endif
125 US"delay",
126 #ifdef WITH_OLD_DEMIME
127 US"demime",
128 #endif
129 #ifndef DISABLE_DKIM
130 US"dkim_signers",
131 US"dkim_status",
132 #endif
133 US"dnslists",
134 US"domains",
135 US"encrypted",
136 US"endpass",
137 US"hosts",
138 US"local_parts",
139 US"log_message",
140 US"log_reject_target",
141 US"logwrite",
142 #ifdef WITH_CONTENT_SCAN
143 US"malware",
144 #endif
145 US"message",
146 #ifdef WITH_CONTENT_SCAN
147 US"mime_regex",
148 #endif
149 US"ratelimit",
150 US"recipients",
151 #ifdef WITH_CONTENT_SCAN
152 US"regex",
153 #endif
154 US"remove_header",
155 US"sender_domains", US"senders", US"set",
156 #ifdef WITH_CONTENT_SCAN
157 US"spam",
158 #endif
159 #ifdef EXPERIMENTAL_SPF
160 US"spf",
161 US"spf_guess",
162 #endif
163 US"verify" };
164
165
166 /* Return values from decode_control(); keep in step with the table of names
167 that follows! */
168
169 enum {
170 CONTROL_AUTH_UNADVERTISED,
171 #ifdef EXPERIMENTAL_BRIGHTMAIL
172 CONTROL_BMI_RUN,
173 #endif
174 CONTROL_DEBUG,
175 #ifndef DISABLE_DKIM
176 CONTROL_DKIM_VERIFY,
177 #endif
178 CONTROL_DSCP,
179 CONTROL_ERROR,
180 CONTROL_CASEFUL_LOCAL_PART,
181 CONTROL_CASELOWER_LOCAL_PART,
182 CONTROL_CUTTHROUGH_DELIVERY,
183 CONTROL_ENFORCE_SYNC,
184 CONTROL_NO_ENFORCE_SYNC,
185 CONTROL_FREEZE,
186 CONTROL_QUEUE_ONLY,
187 CONTROL_SUBMISSION,
188 CONTROL_SUPPRESS_LOCAL_FIXUPS,
189 #ifdef WITH_CONTENT_SCAN
190 CONTROL_NO_MBOX_UNSPOOL,
191 #endif
192 CONTROL_FAKEDEFER,
193 CONTROL_FAKEREJECT,
194 CONTROL_NO_MULTILINE,
195 CONTROL_NO_PIPELINING,
196 CONTROL_NO_DELAY_FLUSH,
197 CONTROL_NO_CALLOUT_FLUSH
198 };
199
200 /* ACL control names; keep in step with the table above! This list is used for
201 turning ids into names. The actual list of recognized names is in the variable
202 control_def controls_list[] below. The fact that there are two lists is a mess
203 and should be tidied up. */
204
205 static uschar *controls[] = {
206 US"allow_auth_unadvertised",
207 #ifdef EXPERIMENTAL_BRIGHTMAIL
208 US"bmi_run",
209 #endif
210 US"debug",
211 #ifndef DISABLE_DKIM
212 US"dkim_disable_verify",
213 #endif
214 US"dscp",
215 US"error",
216 US"caseful_local_part",
217 US"caselower_local_part",
218 US"cutthrough_delivery",
219 US"enforce_sync",
220 US"no_enforce_sync",
221 US"freeze",
222 US"queue_only",
223 US"submission",
224 US"suppress_local_fixups",
225 #ifdef WITH_CONTENT_SCAN
226 US"no_mbox_unspool",
227 #endif
228 US"fakedefer",
229 US"fakereject",
230 US"no_multiline_responses",
231 US"no_pipelining",
232 US"no_delay_flush",
233 US"no_callout_flush"
234 };
235
236 /* Flags to indicate for which conditions/modifiers a string expansion is done
237 at the outer level. In the other cases, expansion already occurs in the
238 checking functions. */
239
240 static uschar cond_expand_at_top[] = {
241 FALSE, /* acl */
242 TRUE, /* add_header */
243 FALSE, /* authenticated */
244 #ifdef EXPERIMENTAL_BRIGHTMAIL
245 TRUE, /* bmi_optin */
246 #endif
247 TRUE, /* condition */
248 TRUE, /* continue */
249 TRUE, /* control */
250 #ifdef EXPERIMENTAL_DCC
251 TRUE, /* dcc */
252 #endif
253 #ifdef WITH_CONTENT_SCAN
254 TRUE, /* decode */
255 #endif
256 TRUE, /* delay */
257 #ifdef WITH_OLD_DEMIME
258 TRUE, /* demime */
259 #endif
260 #ifndef DISABLE_DKIM
261 TRUE, /* dkim_signers */
262 TRUE, /* dkim_status */
263 #endif
264 TRUE, /* dnslists */
265 FALSE, /* domains */
266 FALSE, /* encrypted */
267 TRUE, /* endpass */
268 FALSE, /* hosts */
269 FALSE, /* local_parts */
270 TRUE, /* log_message */
271 TRUE, /* log_reject_target */
272 TRUE, /* logwrite */
273 #ifdef WITH_CONTENT_SCAN
274 TRUE, /* malware */
275 #endif
276 TRUE, /* message */
277 #ifdef WITH_CONTENT_SCAN
278 TRUE, /* mime_regex */
279 #endif
280 TRUE, /* ratelimit */
281 FALSE, /* recipients */
282 #ifdef WITH_CONTENT_SCAN
283 TRUE, /* regex */
284 #endif
285 TRUE, /* remove_header */
286 FALSE, /* sender_domains */
287 FALSE, /* senders */
288 TRUE, /* set */
289 #ifdef WITH_CONTENT_SCAN
290 TRUE, /* spam */
291 #endif
292 #ifdef EXPERIMENTAL_SPF
293 TRUE, /* spf */
294 TRUE, /* spf_guess */
295 #endif
296 TRUE /* verify */
297 };
298
299 /* Flags to identify the modifiers */
300
301 static uschar cond_modifiers[] = {
302 FALSE, /* acl */
303 TRUE, /* add_header */
304 FALSE, /* authenticated */
305 #ifdef EXPERIMENTAL_BRIGHTMAIL
306 TRUE, /* bmi_optin */
307 #endif
308 FALSE, /* condition */
309 TRUE, /* continue */
310 TRUE, /* control */
311 #ifdef EXPERIMENTAL_DCC
312 FALSE, /* dcc */
313 #endif
314 #ifdef WITH_CONTENT_SCAN
315 FALSE, /* decode */
316 #endif
317 TRUE, /* delay */
318 #ifdef WITH_OLD_DEMIME
319 FALSE, /* demime */
320 #endif
321 #ifndef DISABLE_DKIM
322 FALSE, /* dkim_signers */
323 FALSE, /* dkim_status */
324 #endif
325 FALSE, /* dnslists */
326 FALSE, /* domains */
327 FALSE, /* encrypted */
328 TRUE, /* endpass */
329 FALSE, /* hosts */
330 FALSE, /* local_parts */
331 TRUE, /* log_message */
332 TRUE, /* log_reject_target */
333 TRUE, /* logwrite */
334 #ifdef WITH_CONTENT_SCAN
335 FALSE, /* malware */
336 #endif
337 TRUE, /* message */
338 #ifdef WITH_CONTENT_SCAN
339 FALSE, /* mime_regex */
340 #endif
341 FALSE, /* ratelimit */
342 FALSE, /* recipients */
343 #ifdef WITH_CONTENT_SCAN
344 FALSE, /* regex */
345 #endif
346 TRUE, /* remove_header */
347 FALSE, /* sender_domains */
348 FALSE, /* senders */
349 TRUE, /* set */
350 #ifdef WITH_CONTENT_SCAN
351 FALSE, /* spam */
352 #endif
353 #ifdef EXPERIMENTAL_SPF
354 FALSE, /* spf */
355 FALSE, /* spf_guess */
356 #endif
357 FALSE /* verify */
358 };
359
360 /* Bit map vector of which conditions and modifiers are not allowed at certain
361 times. For each condition and modifier, there's a bitmap of dis-allowed times.
362 For some, it is easier to specify the negation of a small number of allowed
363 times. */
364
365 static unsigned int cond_forbids[] = {
366 0, /* acl */
367
368 (unsigned int)
369 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
370 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
371 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
372 (1<<ACL_WHERE_DKIM)|
373 (1<<ACL_WHERE_NOTSMTP_START)),
374
375 (1<<ACL_WHERE_NOTSMTP)| /* authenticated */
376 (1<<ACL_WHERE_NOTSMTP_START)|
377 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
378
379 #ifdef EXPERIMENTAL_BRIGHTMAIL
380 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
381 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
382 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
383 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
384 (1<<ACL_WHERE_MAILAUTH)|
385 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
386 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
387 (1<<ACL_WHERE_NOTSMTP_START),
388 #endif
389
390 0, /* condition */
391
392 0, /* continue */
393
394 /* Certain types of control are always allowed, so we let it through
395 always and check in the control processing itself. */
396
397 0, /* control */
398
399 #ifdef EXPERIMENTAL_DCC
400 (unsigned int)
401 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* dcc */
402 #endif
403
404 #ifdef WITH_CONTENT_SCAN
405 (unsigned int)
406 ~(1<<ACL_WHERE_MIME), /* decode */
407 #endif
408
409 (1<<ACL_WHERE_NOTQUIT), /* delay */
410
411 #ifdef WITH_OLD_DEMIME
412 (unsigned int)
413 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
414 #endif
415
416 #ifndef DISABLE_DKIM
417 (unsigned int)
418 ~(1<<ACL_WHERE_DKIM), /* dkim_signers */
419
420 (unsigned int)
421 ~(1<<ACL_WHERE_DKIM), /* dkim_status */
422 #endif
423
424 (1<<ACL_WHERE_NOTSMTP)| /* dnslists */
425 (1<<ACL_WHERE_NOTSMTP_START),
426
427 (unsigned int)
428 ~(1<<ACL_WHERE_RCPT), /* domains */
429
430 (1<<ACL_WHERE_NOTSMTP)| /* encrypted */
431 (1<<ACL_WHERE_CONNECT)|
432 (1<<ACL_WHERE_NOTSMTP_START)|
433 (1<<ACL_WHERE_HELO),
434
435 0, /* endpass */
436
437 (1<<ACL_WHERE_NOTSMTP)| /* hosts */
438 (1<<ACL_WHERE_NOTSMTP_START),
439
440 (unsigned int)
441 ~(1<<ACL_WHERE_RCPT), /* local_parts */
442
443 0, /* log_message */
444
445 0, /* log_reject_target */
446
447 0, /* logwrite */
448
449 #ifdef WITH_CONTENT_SCAN
450 (unsigned int)
451 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
452 #endif
453
454 0, /* message */
455
456 #ifdef WITH_CONTENT_SCAN
457 (unsigned int)
458 ~(1<<ACL_WHERE_MIME), /* mime_regex */
459 #endif
460
461 0, /* ratelimit */
462
463 (unsigned int)
464 ~(1<<ACL_WHERE_RCPT), /* recipients */
465
466 #ifdef WITH_CONTENT_SCAN
467 (unsigned int)
468 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
469 (1<<ACL_WHERE_MIME)),
470 #endif
471
472 (unsigned int)
473 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* remove_header */
474 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
475 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
476 (1<<ACL_WHERE_NOTSMTP_START)),
477
478 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
479 (1<<ACL_WHERE_HELO)|
480 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
481 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
482 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
483
484 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
485 (1<<ACL_WHERE_HELO)|
486 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
487 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
488 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
489
490 0, /* set */
491
492 #ifdef WITH_CONTENT_SCAN
493 (unsigned int)
494 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
495 #endif
496
497 #ifdef EXPERIMENTAL_SPF
498 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
499 (1<<ACL_WHERE_HELO)|
500 (1<<ACL_WHERE_MAILAUTH)|
501 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
502 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
503 (1<<ACL_WHERE_NOTSMTP)|
504 (1<<ACL_WHERE_NOTSMTP_START),
505
506 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf_guess */
507 (1<<ACL_WHERE_HELO)|
508 (1<<ACL_WHERE_MAILAUTH)|
509 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
510 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
511 (1<<ACL_WHERE_NOTSMTP)|
512 (1<<ACL_WHERE_NOTSMTP_START),
513 #endif
514
515 /* Certain types of verify are always allowed, so we let it through
516 always and check in the verify function itself */
517
518 0 /* verify */
519 };
520
521
522 /* Bit map vector of which controls are not allowed at certain times. For
523 each control, there's a bitmap of dis-allowed times. For some, it is easier to
524 specify the negation of a small number of allowed times. */
525
526 static unsigned int control_forbids[] = {
527 (unsigned int)
528 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
529
530 #ifdef EXPERIMENTAL_BRIGHTMAIL
531 0, /* bmi_run */
532 #endif
533
534 0, /* debug */
535
536 #ifndef DISABLE_DKIM
537 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_disable_verify */
538 (1<<ACL_WHERE_NOTSMTP_START),
539 #endif
540
541 (1<<ACL_WHERE_NOTSMTP)|
542 (1<<ACL_WHERE_NOTSMTP_START)|
543 (1<<ACL_WHERE_NOTQUIT), /* dscp */
544
545 0, /* error */
546
547 (unsigned int)
548 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
549
550 (unsigned int)
551 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
552
553 (unsigned int)
554 0, /* cutthrough_delivery */
555
556 (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
557 (1<<ACL_WHERE_NOTSMTP_START),
558
559 (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
560 (1<<ACL_WHERE_NOTSMTP_START),
561
562 (unsigned int)
563 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
564 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
565 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
566
567 (unsigned int)
568 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
569 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
570 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
571
572 (unsigned int)
573 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
574 (1<<ACL_WHERE_PREDATA)),
575
576 (unsigned int)
577 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
578 (1<<ACL_WHERE_PREDATA)|
579 (1<<ACL_WHERE_NOTSMTP_START)),
580
581 #ifdef WITH_CONTENT_SCAN
582 (unsigned int)
583 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
584 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
585 (1<<ACL_WHERE_MIME)),
586 #endif
587
588 (unsigned int)
589 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
590 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
591 (1<<ACL_WHERE_MIME)),
592
593 (unsigned int)
594 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
595 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
596 (1<<ACL_WHERE_MIME)),
597
598 (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
599 (1<<ACL_WHERE_NOTSMTP_START),
600
601 (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
602 (1<<ACL_WHERE_NOTSMTP_START),
603
604 (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
605 (1<<ACL_WHERE_NOTSMTP_START),
606
607 (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
608 (1<<ACL_WHERE_NOTSMTP_START)
609 };
610
611 /* Structure listing various control arguments, with their characteristics. */
612
613 typedef struct control_def {
614 uschar *name;
615 int value; /* CONTROL_xxx value */
616 BOOL has_option; /* Has /option(s) following */
617 } control_def;
618
619 static control_def controls_list[] = {
620 { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
621 #ifdef EXPERIMENTAL_BRIGHTMAIL
622 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
623 #endif
624 { US"debug", CONTROL_DEBUG, TRUE },
625 #ifndef DISABLE_DKIM
626 { US"dkim_disable_verify", CONTROL_DKIM_VERIFY, FALSE },
627 #endif
628 { US"dscp", CONTROL_DSCP, TRUE },
629 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
630 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
631 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
632 { US"freeze", CONTROL_FREEZE, TRUE },
633 { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
634 { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
635 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
636 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
637 { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
638 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
639 #ifdef WITH_CONTENT_SCAN
640 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
641 #endif
642 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
643 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
644 { US"submission", CONTROL_SUBMISSION, TRUE },
645 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE },
646 { US"cutthrough_delivery", CONTROL_CUTTHROUGH_DELIVERY, FALSE }
647 };
648
649 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
650 caches its result in a tree to avoid repeated DNS queries. The result is an
651 integer code which is used as an index into the following tables of
652 explanatory strings and verification return codes. */
653
654 static tree_node *csa_cache = NULL;
655
656 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
657 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
658
659 /* The acl_verify_csa() return code is translated into an acl_verify() return
660 code using the following table. It is OK unless the client is definitely not
661 authorized. This is because CSA is supposed to be optional for sending sites,
662 so recipients should not be too strict about checking it - especially because
663 DNS problems are quite likely to occur. It's possible to use $csa_status in
664 further ACL conditions to distinguish ok, unknown, and defer if required, but
665 the aim is to make the usual configuration simple. */
666
667 static int csa_return_code[] = {
668 OK, OK, OK, OK,
669 FAIL, FAIL, FAIL, FAIL
670 };
671
672 static uschar *csa_status_string[] = {
673 US"unknown", US"ok", US"defer", US"defer",
674 US"fail", US"fail", US"fail", US"fail"
675 };
676
677 static uschar *csa_reason_string[] = {
678 US"unknown",
679 US"ok",
680 US"deferred (SRV lookup failed)",
681 US"deferred (target address lookup failed)",
682 US"failed (explicit authorization required)",
683 US"failed (host name not authorized)",
684 US"failed (no authorized addresses)",
685 US"failed (client address mismatch)"
686 };
687
688 /* Options for the ratelimit condition. Note that there are two variants of
689 the per_rcpt option, depending on the ACL that is used to measure the rate.
690 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
691 so the two variants must have the same internal representation as well as
692 the same configuration string. */
693
694 enum {
695 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
696 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
697 };
698
699 #define RATE_SET(var,new) \
700 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
701
702 static uschar *ratelimit_option_string[] = {
703 US"?", US"!", US"per_addr", US"per_byte", US"per_cmd",
704 US"per_conn", US"per_mail", US"per_rcpt", US"per_rcpt"
705 };
706
707 /* Enable recursion between acl_check_internal() and acl_check_condition() */
708
709 static int acl_check_wargs(int, address_item *, uschar *, int, uschar **,
710 uschar **);
711
712
713 /*************************************************
714 * Pick out name from list *
715 *************************************************/
716
717 /* Use a binary chop method
718
719 Arguments:
720 name name to find
721 list list of names
722 end size of list
723
724 Returns: offset in list, or -1 if not found
725 */
726
727 static int
728 acl_checkname(uschar *name, uschar **list, int end)
729 {
730 int start = 0;
731
732 while (start < end)
733 {
734 int mid = (start + end)/2;
735 int c = Ustrcmp(name, list[mid]);
736 if (c == 0) return mid;
737 if (c < 0) end = mid; else start = mid + 1;
738 }
739
740 return -1;
741 }
742
743
744 /*************************************************
745 * Read and parse one ACL *
746 *************************************************/
747
748 /* This function is called both from readconf in order to parse the ACLs in the
749 configuration file, and also when an ACL is encountered dynamically (e.g. as
750 the result of an expansion). It is given a function to call in order to
751 retrieve the lines of the ACL. This function handles skipping comments and
752 blank lines (where relevant).
753
754 Arguments:
755 func function to get next line of ACL
756 error where to put an error message
757
758 Returns: pointer to ACL, or NULL
759 NULL can be legal (empty ACL); in this case error will be NULL
760 */
761
762 acl_block *
763 acl_read(uschar *(*func)(void), uschar **error)
764 {
765 acl_block *yield = NULL;
766 acl_block **lastp = &yield;
767 acl_block *this = NULL;
768 acl_condition_block *cond;
769 acl_condition_block **condp = NULL;
770 uschar *s;
771
772 *error = NULL;
773
774 while ((s = (*func)()) != NULL)
775 {
776 int v, c;
777 BOOL negated = FALSE;
778 uschar *saveline = s;
779 uschar name[64];
780
781 /* Conditions (but not verbs) are allowed to be negated by an initial
782 exclamation mark. */
783
784 while (isspace(*s)) s++;
785 if (*s == '!')
786 {
787 negated = TRUE;
788 s++;
789 }
790
791 /* Read the name of a verb or a condition, or the start of a new ACL, which
792 can be started by a name, or by a macro definition. */
793
794 s = readconf_readname(name, sizeof(name), s);
795 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
796
797 /* If a verb is unrecognized, it may be another condition or modifier that
798 continues the previous verb. */
799
800 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
801 if (v < 0)
802 {
803 if (this == NULL)
804 {
805 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
806 saveline);
807 return NULL;
808 }
809 }
810
811 /* New verb */
812
813 else
814 {
815 if (negated)
816 {
817 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
818 return NULL;
819 }
820 this = store_get(sizeof(acl_block));
821 *lastp = this;
822 lastp = &(this->next);
823 this->next = NULL;
824 this->verb = v;
825 this->condition = NULL;
826 condp = &(this->condition);
827 if (*s == 0) continue; /* No condition on this line */
828 if (*s == '!')
829 {
830 negated = TRUE;
831 s++;
832 }
833 s = readconf_readname(name, sizeof(name), s); /* Condition name */
834 }
835
836 /* Handle a condition or modifier. */
837
838 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
839 if (c < 0)
840 {
841 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
842 saveline);
843 return NULL;
844 }
845
846 /* The modifiers may not be negated */
847
848 if (negated && cond_modifiers[c])
849 {
850 *error = string_sprintf("ACL error: negation is not allowed with "
851 "\"%s\"", conditions[c]);
852 return NULL;
853 }
854
855 /* ENDPASS may occur only with ACCEPT or DISCARD. */
856
857 if (c == ACLC_ENDPASS &&
858 this->verb != ACL_ACCEPT &&
859 this->verb != ACL_DISCARD)
860 {
861 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
862 conditions[c], verbs[this->verb]);
863 return NULL;
864 }
865
866 cond = store_get(sizeof(acl_condition_block));
867 cond->next = NULL;
868 cond->type = c;
869 cond->u.negated = negated;
870
871 *condp = cond;
872 condp = &(cond->next);
873
874 /* The "set" modifier is different in that its argument is "name=value"
875 rather than just a value, and we can check the validity of the name, which
876 gives us a variable name to insert into the data block. The original ACL
877 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
878 extended to 20 of each type, but after that people successfully argued for
879 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
880 After that, we allow alphanumerics and underscores, but the first character
881 after c or m must be a digit or an underscore. This retains backwards
882 compatibility. */
883
884 if (c == ACLC_SET)
885 {
886 uschar *endptr;
887
888 if (Ustrncmp(s, "acl_c", 5) != 0 &&
889 Ustrncmp(s, "acl_m", 5) != 0)
890 {
891 *error = string_sprintf("invalid variable name after \"set\" in ACL "
892 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
893 return NULL;
894 }
895
896 endptr = s + 5;
897 if (!isdigit(*endptr) && *endptr != '_')
898 {
899 *error = string_sprintf("invalid variable name after \"set\" in ACL "
900 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
901 s);
902 return NULL;
903 }
904
905 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
906 {
907 if (!isalnum(*endptr) && *endptr != '_')
908 {
909 *error = string_sprintf("invalid character \"%c\" in variable name "
910 "in ACL modifier \"set %s\"", *endptr, s);
911 return NULL;
912 }
913 endptr++;
914 }
915
916 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
917 s = endptr;
918 while (isspace(*s)) s++;
919 }
920
921 /* For "set", we are now positioned for the data. For the others, only
922 "endpass" has no data */
923
924 if (c != ACLC_ENDPASS)
925 {
926 if (*s++ != '=')
927 {
928 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
929 cond_modifiers[c]? US"modifier" : US"condition");
930 return NULL;
931 }
932 while (isspace(*s)) s++;
933 cond->arg = string_copy(s);
934 }
935 }
936
937 return yield;
938 }
939
940
941
942 /*************************************************
943 * Set up added header line(s) *
944 *************************************************/
945
946 /* This function is called by the add_header modifier, and also from acl_warn()
947 to implement the now-deprecated way of adding header lines using "message" on a
948 "warn" verb. The argument is treated as a sequence of header lines which are
949 added to a chain, provided there isn't an identical one already there.
950
951 Argument: string of header lines
952 Returns: nothing
953 */
954
955 static void
956 setup_header(uschar *hstring)
957 {
958 uschar *p, *q;
959 int hlen = Ustrlen(hstring);
960
961 /* Ignore any leading newlines */
962 while (*hstring == '\n') hstring++, hlen--;
963
964 /* An empty string does nothing; ensure exactly one final newline. */
965 if (hlen <= 0) return;
966 if (hstring[--hlen] != '\n') hstring = string_sprintf("%s\n", hstring);
967 else while(hstring[--hlen] == '\n') hstring[hlen+1] = '\0';
968
969 /* Loop for multiple header lines, taking care about continuations */
970
971 for (p = q = hstring; *p != 0; )
972 {
973 uschar *s;
974 int newtype = htype_add_bot;
975 header_line **hptr = &acl_added_headers;
976
977 /* Find next header line within the string */
978
979 for (;;)
980 {
981 q = Ustrchr(q, '\n');
982 if (*(++q) != ' ' && *q != '\t') break;
983 }
984
985 /* If the line starts with a colon, interpret the instruction for where to
986 add it. This temporarily sets up a new type. */
987
988 if (*p == ':')
989 {
990 if (strncmpic(p, US":after_received:", 16) == 0)
991 {
992 newtype = htype_add_rec;
993 p += 16;
994 }
995 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
996 {
997 newtype = htype_add_rfc;
998 p += 14;
999 }
1000 else if (strncmpic(p, US":at_start:", 10) == 0)
1001 {
1002 newtype = htype_add_top;
1003 p += 10;
1004 }
1005 else if (strncmpic(p, US":at_end:", 8) == 0)
1006 {
1007 newtype = htype_add_bot;
1008 p += 8;
1009 }
1010 while (*p == ' ' || *p == '\t') p++;
1011 }
1012
1013 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1014 to the front of it. */
1015
1016 for (s = p; s < q - 1; s++)
1017 {
1018 if (*s == ':' || !isgraph(*s)) break;
1019 }
1020
1021 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
1022 hlen = Ustrlen(s);
1023
1024 /* See if this line has already been added */
1025
1026 while (*hptr != NULL)
1027 {
1028 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
1029 hptr = &((*hptr)->next);
1030 }
1031
1032 /* Add if not previously present */
1033
1034 if (*hptr == NULL)
1035 {
1036 header_line *h = store_get(sizeof(header_line));
1037 h->text = s;
1038 h->next = NULL;
1039 h->type = newtype;
1040 h->slen = hlen;
1041 *hptr = h;
1042 hptr = &(h->next);
1043 }
1044
1045 /* Advance for next header line within the string */
1046
1047 p = q;
1048 }
1049 }
1050
1051
1052
1053 /*************************************************
1054 * List the added header lines *
1055 *************************************************/
1056 uschar *
1057 fn_hdrs_added(void)
1058 {
1059 uschar * ret = NULL;
1060 header_line * h = acl_added_headers;
1061 uschar * s;
1062 uschar * cp;
1063 int size = 0;
1064 int ptr = 0;
1065
1066 if (!h) return NULL;
1067
1068 do
1069 {
1070 s = h->text;
1071 while ((cp = Ustrchr(s, '\n')) != NULL)
1072 {
1073 if (cp[1] == '\0') break;
1074
1075 /* contains embedded newline; needs doubling */
1076 ret = string_cat(ret, &size, &ptr, s, cp-s+1);
1077 ret = string_cat(ret, &size, &ptr, US"\n", 1);
1078 s = cp+1;
1079 }
1080 /* last bit of header */
1081
1082 ret = string_cat(ret, &size, &ptr, s, cp-s+1); /* newline-sep list */
1083 }
1084 while((h = h->next));
1085
1086 ret[ptr-1] = '\0'; /* overwrite last newline */
1087 return ret;
1088 }
1089
1090
1091 /*************************************************
1092 * Set up removed header line(s) *
1093 *************************************************/
1094
1095 /* This function is called by the remove_header modifier. The argument is
1096 treated as a sequence of header names which are added to a colon separated
1097 list, provided there isn't an identical one already there.
1098
1099 Argument: string of header names
1100 Returns: nothing
1101 */
1102
1103 static void
1104 setup_remove_header(uschar *hnames)
1105 {
1106 if (*hnames != 0)
1107 {
1108 if (acl_removed_headers == NULL)
1109 acl_removed_headers = hnames;
1110 else
1111 acl_removed_headers = string_sprintf("%s : %s", acl_removed_headers, hnames);
1112 }
1113 }
1114
1115
1116
1117 /*************************************************
1118 * Handle warnings *
1119 *************************************************/
1120
1121 /* This function is called when a WARN verb's conditions are true. It adds to
1122 the message's headers, and/or writes information to the log. In each case, this
1123 only happens once (per message for headers, per connection for log).
1124
1125 ** NOTE: The header adding action using the "message" setting is historic, and
1126 its use is now deprecated. The new add_header modifier should be used instead.
1127
1128 Arguments:
1129 where ACL_WHERE_xxxx indicating which ACL this is
1130 user_message message for adding to headers
1131 log_message message for logging, if different
1132
1133 Returns: nothing
1134 */
1135
1136 static void
1137 acl_warn(int where, uschar *user_message, uschar *log_message)
1138 {
1139 if (log_message != NULL && log_message != user_message)
1140 {
1141 uschar *text;
1142 string_item *logged;
1143
1144 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1145 string_printing(log_message));
1146
1147 /* If a sender verification has failed, and the log message is "sender verify
1148 failed", add the failure message. */
1149
1150 if (sender_verified_failed != NULL &&
1151 sender_verified_failed->message != NULL &&
1152 strcmpic(log_message, US"sender verify failed") == 0)
1153 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1154
1155 /* Search previously logged warnings. They are kept in malloc
1156 store so they can be freed at the start of a new message. */
1157
1158 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1159 if (Ustrcmp(logged->text, text) == 0) break;
1160
1161 if (logged == NULL)
1162 {
1163 int length = Ustrlen(text) + 1;
1164 log_write(0, LOG_MAIN, "%s", text);
1165 logged = store_malloc(sizeof(string_item) + length);
1166 logged->text = (uschar *)logged + sizeof(string_item);
1167 memcpy(logged->text, text, length);
1168 logged->next = acl_warn_logged;
1169 acl_warn_logged = logged;
1170 }
1171 }
1172
1173 /* If there's no user message, we are done. */
1174
1175 if (user_message == NULL) return;
1176
1177 /* If this isn't a message ACL, we can't do anything with a user message.
1178 Log an error. */
1179
1180 if (where > ACL_WHERE_NOTSMTP)
1181 {
1182 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1183 "found in a non-message (%s) ACL: cannot specify header lines here: "
1184 "message ignored", acl_wherenames[where]);
1185 return;
1186 }
1187
1188 /* The code for setting up header lines is now abstracted into a separate
1189 function so that it can be used for the add_header modifier as well. */
1190
1191 setup_header(user_message);
1192 }
1193
1194
1195
1196 /*************************************************
1197 * Verify and check reverse DNS *
1198 *************************************************/
1199
1200 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1201 address if this has not yet been done. The host_name_lookup() function checks
1202 that one of these names resolves to an address list that contains the client IP
1203 address, so we don't actually have to do the check here.
1204
1205 Arguments:
1206 user_msgptr pointer for user message
1207 log_msgptr pointer for log message
1208
1209 Returns: OK verification condition succeeded
1210 FAIL verification failed
1211 DEFER there was a problem verifying
1212 */
1213
1214 static int
1215 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1216 {
1217 int rc;
1218
1219 user_msgptr = user_msgptr; /* stop compiler warning */
1220
1221 /* Previous success */
1222
1223 if (sender_host_name != NULL) return OK;
1224
1225 /* Previous failure */
1226
1227 if (host_lookup_failed)
1228 {
1229 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1230 return FAIL;
1231 }
1232
1233 /* Need to do a lookup */
1234
1235 HDEBUG(D_acl)
1236 debug_printf("looking up host name to force name/address consistency check\n");
1237
1238 if ((rc = host_name_lookup()) != OK)
1239 {
1240 *log_msgptr = (rc == DEFER)?
1241 US"host lookup deferred for reverse lookup check"
1242 :
1243 string_sprintf("host lookup failed for reverse lookup check%s",
1244 host_lookup_msg);
1245 return rc; /* DEFER or FAIL */
1246 }
1247
1248 host_build_sender_fullhost();
1249 return OK;
1250 }
1251
1252
1253
1254 /*************************************************
1255 * Check client IP address matches CSA target *
1256 *************************************************/
1257
1258 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1259 response for address records belonging to the CSA target hostname. The section
1260 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1261 If one of the addresses matches the client's IP address, then the client is
1262 authorized by CSA. If there are target IP addresses but none of them match
1263 then the client is using an unauthorized IP address. If there are no target IP
1264 addresses then the client cannot be using an authorized IP address. (This is
1265 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1266
1267 Arguments:
1268 dnsa the DNS answer block
1269 dnss a DNS scan block for us to use
1270 reset option specifing what portion to scan, as described above
1271 target the target hostname to use for matching RR names
1272
1273 Returns: CSA_OK successfully authorized
1274 CSA_FAIL_MISMATCH addresses found but none matched
1275 CSA_FAIL_NOADDR no target addresses found
1276 */
1277
1278 static int
1279 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1280 uschar *target)
1281 {
1282 dns_record *rr;
1283 dns_address *da;
1284
1285 BOOL target_found = FALSE;
1286
1287 for (rr = dns_next_rr(dnsa, dnss, reset);
1288 rr != NULL;
1289 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1290 {
1291 /* Check this is an address RR for the target hostname. */
1292
1293 if (rr->type != T_A
1294 #if HAVE_IPV6
1295 && rr->type != T_AAAA
1296 #ifdef SUPPORT_A6
1297 && rr->type != T_A6
1298 #endif
1299 #endif
1300 ) continue;
1301
1302 if (strcmpic(target, rr->name) != 0) continue;
1303
1304 target_found = TRUE;
1305
1306 /* Turn the target address RR into a list of textual IP addresses and scan
1307 the list. There may be more than one if it is an A6 RR. */
1308
1309 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1310 {
1311 /* If the client IP address matches the target IP address, it's good! */
1312
1313 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1314
1315 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1316 }
1317 }
1318
1319 /* If we found some target addresses but none of them matched, the client is
1320 using an unauthorized IP address, otherwise the target has no authorized IP
1321 addresses. */
1322
1323 if (target_found) return CSA_FAIL_MISMATCH;
1324 else return CSA_FAIL_NOADDR;
1325 }
1326
1327
1328
1329 /*************************************************
1330 * Verify Client SMTP Authorization *
1331 *************************************************/
1332
1333 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1334 to find the CSA SRV record corresponding to the domain argument, or
1335 $sender_helo_name if no argument is provided. It then checks that the
1336 client is authorized, and that its IP address corresponds to the SRV
1337 target's address by calling acl_verify_csa_address() above. The address
1338 should have been returned in the DNS response's ADDITIONAL section, but if
1339 not we perform another DNS lookup to get it.
1340
1341 Arguments:
1342 domain pointer to optional parameter following verify = csa
1343
1344 Returns: CSA_UNKNOWN no valid CSA record found
1345 CSA_OK successfully authorized
1346 CSA_FAIL_* client is definitely not authorized
1347 CSA_DEFER_* there was a DNS problem
1348 */
1349
1350 static int
1351 acl_verify_csa(uschar *domain)
1352 {
1353 tree_node *t;
1354 uschar *found, *p;
1355 int priority, weight, port;
1356 dns_answer dnsa;
1357 dns_scan dnss;
1358 dns_record *rr;
1359 int rc, type;
1360 uschar target[256];
1361
1362 /* Work out the domain we are using for the CSA lookup. The default is the
1363 client's HELO domain. If the client has not said HELO, use its IP address
1364 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1365
1366 while (isspace(*domain) && *domain != '\0') ++domain;
1367 if (*domain == '\0') domain = sender_helo_name;
1368 if (domain == NULL) domain = sender_host_address;
1369 if (sender_host_address == NULL) return CSA_UNKNOWN;
1370
1371 /* If we have an address literal, strip off the framing ready for turning it
1372 into a domain. The framing consists of matched square brackets possibly
1373 containing a keyword and a colon before the actual IP address. */
1374
1375 if (domain[0] == '[')
1376 {
1377 uschar *start = Ustrchr(domain, ':');
1378 if (start == NULL) start = domain;
1379 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1380 }
1381
1382 /* Turn domains that look like bare IP addresses into domains in the reverse
1383 DNS. This code also deals with address literals and $sender_host_address. It's
1384 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1385 address literals, but it's probably the most friendly thing to do. This is an
1386 extension to CSA, so we allow it to be turned off for proper conformance. */
1387
1388 if (string_is_ip_address(domain, NULL) != 0)
1389 {
1390 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1391 dns_build_reverse(domain, target);
1392 domain = target;
1393 }
1394
1395 /* Find out if we've already done the CSA check for this domain. If we have,
1396 return the same result again. Otherwise build a new cached result structure
1397 for this domain. The name is filled in now, and the value is filled in when
1398 we return from this function. */
1399
1400 t = tree_search(csa_cache, domain);
1401 if (t != NULL) return t->data.val;
1402
1403 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1404 Ustrcpy(t->name, domain);
1405 (void)tree_insertnode(&csa_cache, t);
1406
1407 /* Now we are ready to do the actual DNS lookup(s). */
1408
1409 found = domain;
1410 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1411 {
1412 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1413
1414 default:
1415 return t->data.val = CSA_DEFER_SRV;
1416
1417 /* If we found nothing, the client's authorization is unknown. */
1418
1419 case DNS_NOMATCH:
1420 case DNS_NODATA:
1421 return t->data.val = CSA_UNKNOWN;
1422
1423 /* We got something! Go on to look at the reply in more detail. */
1424
1425 case DNS_SUCCEED:
1426 break;
1427 }
1428
1429 /* Scan the reply for well-formed CSA SRV records. */
1430
1431 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1432 rr != NULL;
1433 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1434 {
1435 if (rr->type != T_SRV) continue;
1436
1437 /* Extract the numerical SRV fields (p is incremented) */
1438
1439 p = rr->data;
1440 GETSHORT(priority, p);
1441 GETSHORT(weight, p);
1442 GETSHORT(port, p);
1443
1444 DEBUG(D_acl)
1445 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1446
1447 /* Check the CSA version number */
1448
1449 if (priority != 1) continue;
1450
1451 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1452 found by dns_special_lookup() is a parent of the one we asked for), we check
1453 the subdomain assertions in the port field. At the moment there's only one
1454 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1455 SRV records of their own. */
1456
1457 if (found != domain)
1458 {
1459 if (port & 1)
1460 return t->data.val = CSA_FAIL_EXPLICIT;
1461 else
1462 return t->data.val = CSA_UNKNOWN;
1463 }
1464
1465 /* This CSA SRV record refers directly to our domain, so we check the value
1466 in the weight field to work out the domain's authorization. 0 and 1 are
1467 unauthorized; 3 means the client is authorized but we can't check the IP
1468 address in order to authenticate it, so we treat it as unknown; values
1469 greater than 3 are undefined. */
1470
1471 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1472
1473 if (weight > 2) continue;
1474
1475 /* Weight == 2, which means the domain is authorized. We must check that the
1476 client's IP address is listed as one of the SRV target addresses. Save the
1477 target hostname then break to scan the additional data for its addresses. */
1478
1479 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1480 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1481
1482 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1483
1484 break;
1485 }
1486
1487 /* If we didn't break the loop then no appropriate records were found. */
1488
1489 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1490
1491 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1492 A target of "." indicates there are no valid addresses, so the client cannot
1493 be authorized. (This is an odd configuration because weight=2 target=. is
1494 equivalent to weight=1, but we check for it in order to keep load off the
1495 root name servers.) Note that dn_expand() turns "." into "". */
1496
1497 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1498
1499 /* Scan the additional section of the CSA SRV reply for addresses belonging
1500 to the target. If the name server didn't return any additional data (e.g.
1501 because it does not fully support SRV records), we need to do another lookup
1502 to obtain the target addresses; otherwise we have a definitive result. */
1503
1504 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1505 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1506
1507 /* The DNS lookup type corresponds to the IP version used by the client. */
1508
1509 #if HAVE_IPV6
1510 if (Ustrchr(sender_host_address, ':') != NULL)
1511 type = T_AAAA;
1512 else
1513 #endif /* HAVE_IPV6 */
1514 type = T_A;
1515
1516
1517 #if HAVE_IPV6 && defined(SUPPORT_A6)
1518 DNS_LOOKUP_AGAIN:
1519 #endif
1520
1521 switch (dns_lookup(&dnsa, target, type, NULL))
1522 {
1523 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1524
1525 default:
1526 return t->data.val = CSA_DEFER_ADDR;
1527
1528 /* If the query succeeded, scan the addresses and return the result. */
1529
1530 case DNS_SUCCEED:
1531 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1532 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1533 /* else fall through */
1534
1535 /* If the target has no IP addresses, the client cannot have an authorized
1536 IP address. However, if the target site uses A6 records (not AAAA records)
1537 we have to do yet another lookup in order to check them. */
1538
1539 case DNS_NOMATCH:
1540 case DNS_NODATA:
1541
1542 #if HAVE_IPV6 && defined(SUPPORT_A6)
1543 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1544 #endif
1545
1546 return t->data.val = CSA_FAIL_NOADDR;
1547 }
1548 }
1549
1550
1551
1552 /*************************************************
1553 * Handle verification (address & other) *
1554 *************************************************/
1555
1556 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1557 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT
1558 };
1559 typedef struct {
1560 uschar * name;
1561 int value;
1562 unsigned where_allowed; /* bitmap */
1563 BOOL no_options; /* Never has /option(s) following */
1564 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1565 } verify_type_t;
1566 static verify_type_t verify_type_list[] = {
1567 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, TRUE, 0 },
1568 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1569 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1570 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1571 { US"header_syntax", VERIFY_HDR_SYNTAX, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1572 { US"not_blind", VERIFY_NOT_BLIND, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1573 { US"header_sender", VERIFY_HDR_SNDR, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), FALSE, 0 },
1574 { US"sender", VERIFY_SNDR, (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)
1575 |(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP),
1576 FALSE, 6 },
1577 { US"recipient", VERIFY_RCPT, (1<<ACL_WHERE_RCPT), FALSE, 0 }
1578 };
1579
1580
1581 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1582 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1583 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1584 CALLOUT_TIME
1585 };
1586 typedef struct {
1587 uschar * name;
1588 int value;
1589 int flag;
1590 BOOL has_option; /* Has =option(s) following */
1591 BOOL timeval; /* Has a time value */
1592 } callout_opt_t;
1593 static callout_opt_t callout_opt_list[] = {
1594 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1595 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1596 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1597 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1598 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1599 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1600 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1601 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1602 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1603 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1604 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1605 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1606 };
1607
1608
1609
1610 /* This function implements the "verify" condition. It is called when
1611 encountered in any ACL, because some tests are almost always permitted. Some
1612 just don't make sense, and always fail (for example, an attempt to test a host
1613 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1614
1615 Arguments:
1616 where where called from
1617 addr the recipient address that the ACL is handling, or NULL
1618 arg the argument of "verify"
1619 user_msgptr pointer for user message
1620 log_msgptr pointer for log message
1621 basic_errno where to put verify errno
1622
1623 Returns: OK verification condition succeeded
1624 FAIL verification failed
1625 DEFER there was a problem verifying
1626 ERROR syntax error
1627 */
1628
1629 static int
1630 acl_verify(int where, address_item *addr, uschar *arg,
1631 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1632 {
1633 int sep = '/';
1634 int callout = -1;
1635 int callout_overall = -1;
1636 int callout_connect = -1;
1637 int verify_options = 0;
1638 int rc;
1639 BOOL verify_header_sender = FALSE;
1640 BOOL defer_ok = FALSE;
1641 BOOL callout_defer_ok = FALSE;
1642 BOOL no_details = FALSE;
1643 BOOL success_on_redirect = FALSE;
1644 address_item *sender_vaddr = NULL;
1645 uschar *verify_sender_address = NULL;
1646 uschar *pm_mailfrom = NULL;
1647 uschar *se_mailfrom = NULL;
1648
1649 /* Some of the verify items have slash-separated options; some do not. Diagnose
1650 an error if options are given for items that don't expect them.
1651 */
1652
1653 uschar *slash = Ustrchr(arg, '/');
1654 uschar *list = arg;
1655 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1656 verify_type_t * vp;
1657
1658 if (ss == NULL) goto BAD_VERIFY;
1659
1660 /* Handle name/address consistency verification in a separate function. */
1661
1662 for (vp= verify_type_list;
1663 (char *)vp < (char *)verify_type_list + sizeof(verify_type_list);
1664 vp++
1665 )
1666 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1667 : strcmpic (ss, vp->name) == 0)
1668 break;
1669 if ((char *)vp >= (char *)verify_type_list + sizeof(verify_type_list))
1670 goto BAD_VERIFY;
1671
1672 if (vp->no_options && slash != NULL)
1673 {
1674 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1675 "(this verify item has no options)", arg);
1676 return ERROR;
1677 }
1678 if (!(vp->where_allowed & (1<<where)))
1679 {
1680 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", vp->name, acl_wherenames[where]);
1681 return ERROR;
1682 }
1683 switch(vp->value)
1684 {
1685 case VERIFY_REV_HOST_LKUP:
1686 if (sender_host_address == NULL) return OK;
1687 return acl_verify_reverse(user_msgptr, log_msgptr);
1688
1689 case VERIFY_CERT:
1690 /* TLS certificate verification is done at STARTTLS time; here we just
1691 test whether it was successful or not. (This is for optional verification; for
1692 mandatory verification, the connection doesn't last this long.) */
1693
1694 if (tls_in.certificate_verified) return OK;
1695 *user_msgptr = US"no verified certificate";
1696 return FAIL;
1697
1698 case VERIFY_HELO:
1699 /* We can test the result of optional HELO verification that might have
1700 occurred earlier. If not, we can attempt the verification now. */
1701
1702 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1703 return helo_verified? OK : FAIL;
1704
1705 case VERIFY_CSA:
1706 /* Do Client SMTP Authorization checks in a separate function, and turn the
1707 result code into user-friendly strings. */
1708
1709 rc = acl_verify_csa(list);
1710 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1711 csa_reason_string[rc]);
1712 csa_status = csa_status_string[rc];
1713 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1714 return csa_return_code[rc];
1715
1716 case VERIFY_HDR_SYNTAX:
1717 /* Check that all relevant header lines have the correct syntax. If there is
1718 a syntax error, we return details of the error to the sender if configured to
1719 send out full details. (But a "message" setting on the ACL can override, as
1720 always). */
1721
1722 rc = verify_check_headers(log_msgptr);
1723 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1724 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1725 return rc;
1726
1727 case VERIFY_NOT_BLIND:
1728 /* Check that no recipient of this message is "blind", that is, every envelope
1729 recipient must be mentioned in either To: or Cc:. */
1730
1731 rc = verify_check_notblind();
1732 if (rc != OK)
1733 {
1734 *log_msgptr = string_sprintf("bcc recipient detected");
1735 if (smtp_return_error_details)
1736 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1737 }
1738 return rc;
1739
1740 /* The remaining verification tests check recipient and sender addresses,
1741 either from the envelope or from the header. There are a number of
1742 slash-separated options that are common to all of them. */
1743
1744 case VERIFY_HDR_SNDR:
1745 verify_header_sender = TRUE;
1746 break;
1747
1748 case VERIFY_SNDR:
1749 /* In the case of a sender, this can optionally be followed by an address to use
1750 in place of the actual sender (rare special-case requirement). */
1751 {
1752 uschar *s = ss + 6;
1753 if (*s == 0)
1754 verify_sender_address = sender_address;
1755 else
1756 {
1757 while (isspace(*s)) s++;
1758 if (*s++ != '=') goto BAD_VERIFY;
1759 while (isspace(*s)) s++;
1760 verify_sender_address = string_copy(s);
1761 }
1762 }
1763 break;
1764
1765 case VERIFY_RCPT:
1766 break;
1767 }
1768
1769
1770
1771 /* Remaining items are optional; they apply to sender and recipient
1772 verification, including "header sender" verification. */
1773
1774 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1775 != NULL)
1776 {
1777 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1778 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1779 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1780
1781 /* These two old options are left for backwards compatibility */
1782
1783 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1784 {
1785 callout_defer_ok = TRUE;
1786 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1787 }
1788
1789 else if (strcmpic(ss, US"check_postmaster") == 0)
1790 {
1791 pm_mailfrom = US"";
1792 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1793 }
1794
1795 /* The callout option has a number of sub-options, comma separated */
1796
1797 else if (strncmpic(ss, US"callout", 7) == 0)
1798 {
1799 callout = CALLOUT_TIMEOUT_DEFAULT;
1800 ss += 7;
1801 if (*ss != 0)
1802 {
1803 while (isspace(*ss)) ss++;
1804 if (*ss++ == '=')
1805 {
1806 int optsep = ',';
1807 uschar *opt;
1808 uschar buffer[256];
1809 while (isspace(*ss)) ss++;
1810
1811 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1812 != NULL)
1813 {
1814 callout_opt_t * op;
1815 double period = 1.0F;
1816
1817 for (op= callout_opt_list; op->name; op++)
1818 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1819 break;
1820
1821 verify_options |= op->flag;
1822 if (op->has_option)
1823 {
1824 opt += Ustrlen(op->name);
1825 while (isspace(*opt)) opt++;
1826 if (*opt++ != '=')
1827 {
1828 *log_msgptr = string_sprintf("'=' expected after "
1829 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1830 return ERROR;
1831 }
1832 while (isspace(*opt)) opt++;
1833 }
1834 if (op->timeval)
1835 {
1836 period = readconf_readtime(opt, 0, FALSE);
1837 if (period < 0)
1838 {
1839 *log_msgptr = string_sprintf("bad time value in ACL condition "
1840 "\"verify %s\"", arg);
1841 return ERROR;
1842 }
1843 }
1844
1845 switch(op->value)
1846 {
1847 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1848 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1849 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1850 case CALLOUT_MAILFROM:
1851 if (!verify_header_sender)
1852 {
1853 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1854 "callout option only for verify=header_sender (detected in ACL "
1855 "condition \"%s\")", arg);
1856 return ERROR;
1857 }
1858 se_mailfrom = string_copy(opt);
1859 break;
1860 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1861 case CALLOUT_MAXWAIT: callout_overall = period; break;
1862 case CALLOUT_CONNECT: callout_connect = period; break;
1863 case CALLOUT_TIME: callout = period; break;
1864 }
1865 }
1866 }
1867 else
1868 {
1869 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1870 "ACL condition \"%s\"", arg);
1871 return ERROR;
1872 }
1873 }
1874 }
1875
1876 /* Option not recognized */
1877
1878 else
1879 {
1880 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1881 "condition \"verify %s\"", ss, arg);
1882 return ERROR;
1883 }
1884 }
1885
1886 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1887 (vopt_callout_recipsender|vopt_callout_recippmaster))
1888 {
1889 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1890 "for a recipient callout";
1891 return ERROR;
1892 }
1893
1894 /* Handle sender-in-header verification. Default the user message to the log
1895 message if giving out verification details. */
1896
1897 if (verify_header_sender)
1898 {
1899 int verrno;
1900 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1901 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1902 &verrno);
1903 if (rc != OK)
1904 {
1905 *basic_errno = verrno;
1906 if (smtp_return_error_details)
1907 {
1908 if (*user_msgptr == NULL && *log_msgptr != NULL)
1909 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1910 if (rc == DEFER) acl_temp_details = TRUE;
1911 }
1912 }
1913 }
1914
1915 /* Handle a sender address. The default is to verify *the* sender address, but
1916 optionally a different address can be given, for special requirements. If the
1917 address is empty, we are dealing with a bounce message that has no sender, so
1918 we cannot do any checking. If the real sender address gets rewritten during
1919 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1920 during message reception.
1921
1922 A list of verified "sender" addresses is kept to try to avoid doing to much
1923 work repetitively when there are multiple recipients in a message and they all
1924 require sender verification. However, when callouts are involved, it gets too
1925 complicated because different recipients may require different callout options.
1926 Therefore, we always do a full sender verify when any kind of callout is
1927 specified. Caching elsewhere, for instance in the DNS resolver and in the
1928 callout handling, should ensure that this is not terribly inefficient. */
1929
1930 else if (verify_sender_address != NULL)
1931 {
1932 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1933 != 0)
1934 {
1935 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1936 "sender verify callout";
1937 return ERROR;
1938 }
1939
1940 sender_vaddr = verify_checked_sender(verify_sender_address);
1941 if (sender_vaddr != NULL && /* Previously checked */
1942 callout <= 0) /* No callout needed this time */
1943 {
1944 /* If the "routed" flag is set, it means that routing worked before, so
1945 this check can give OK (the saved return code value, if set, belongs to a
1946 callout that was done previously). If the "routed" flag is not set, routing
1947 must have failed, so we use the saved return code. */
1948
1949 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1950 {
1951 rc = sender_vaddr->special_action;
1952 *basic_errno = sender_vaddr->basic_errno;
1953 }
1954 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1955 }
1956
1957 /* Do a new verification, and cache the result. The cache is used to avoid
1958 verifying the sender multiple times for multiple RCPTs when callouts are not
1959 specified (see comments above).
1960
1961 The cache is also used on failure to give details in response to the first
1962 RCPT that gets bounced for this reason. However, this can be suppressed by
1963 the no_details option, which sets the flag that says "this detail has already
1964 been sent". The cache normally contains just one address, but there may be
1965 more in esoteric circumstances. */
1966
1967 else
1968 {
1969 BOOL routed = TRUE;
1970 uschar *save_address_data = deliver_address_data;
1971
1972 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1973 if (no_details) setflag(sender_vaddr, af_sverify_told);
1974 if (verify_sender_address[0] != 0)
1975 {
1976 /* If this is the real sender address, save the unrewritten version
1977 for use later in receive. Otherwise, set a flag so that rewriting the
1978 sender in verify_address() does not update sender_address. */
1979
1980 if (verify_sender_address == sender_address)
1981 sender_address_unrewritten = sender_address;
1982 else
1983 verify_options |= vopt_fake_sender;
1984
1985 if (success_on_redirect)
1986 verify_options |= vopt_success_on_redirect;
1987
1988 /* The recipient, qualify, and expn options are never set in
1989 verify_options. */
1990
1991 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1992 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1993
1994 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1995
1996 if (rc == OK)
1997 {
1998 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1999 {
2000 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
2001 verify_sender_address, sender_vaddr->address);
2002 }
2003 else
2004 {
2005 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
2006 verify_sender_address);
2007 }
2008 }
2009 else *basic_errno = sender_vaddr->basic_errno;
2010 }
2011 else rc = OK; /* Null sender */
2012
2013 /* Cache the result code */
2014
2015 if (routed) setflag(sender_vaddr, af_verify_routed);
2016 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2017 sender_vaddr->special_action = rc;
2018 sender_vaddr->next = sender_verified_list;
2019 sender_verified_list = sender_vaddr;
2020
2021 /* Restore the recipient address data, which might have been clobbered by
2022 the sender verification. */
2023
2024 deliver_address_data = save_address_data;
2025 }
2026
2027 /* Put the sender address_data value into $sender_address_data */
2028
2029 sender_address_data = sender_vaddr->p.address_data;
2030 }
2031
2032 /* A recipient address just gets a straightforward verify; again we must handle
2033 the DEFER overrides. */
2034
2035 else
2036 {
2037 address_item addr2;
2038
2039 if (success_on_redirect)
2040 verify_options |= vopt_success_on_redirect;
2041
2042 /* We must use a copy of the address for verification, because it might
2043 get rewritten. */
2044
2045 addr2 = *addr;
2046 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2047 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2048 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
2049
2050 *basic_errno = addr2.basic_errno;
2051 *log_msgptr = addr2.message;
2052 *user_msgptr = (addr2.user_message != NULL)?
2053 addr2.user_message : addr2.message;
2054
2055 /* Allow details for temporary error if the address is so flagged. */
2056 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
2057
2058 /* Make $address_data visible */
2059 deliver_address_data = addr2.p.address_data;
2060 }
2061
2062 /* We have a result from the relevant test. Handle defer overrides first. */
2063
2064 if (rc == DEFER && (defer_ok ||
2065 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2066 {
2067 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
2068 defer_ok? "defer_ok" : "callout_defer_ok");
2069 rc = OK;
2070 }
2071
2072 /* If we've failed a sender, set up a recipient message, and point
2073 sender_verified_failed to the address item that actually failed. */
2074
2075 if (rc != OK && verify_sender_address != NULL)
2076 {
2077 if (rc != DEFER)
2078 {
2079 *log_msgptr = *user_msgptr = US"Sender verify failed";
2080 }
2081 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2082 {
2083 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2084 }
2085 else
2086 {
2087 *log_msgptr = US"Could not complete sender verify callout";
2088 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2089 *log_msgptr;
2090 }
2091
2092 sender_verified_failed = sender_vaddr;
2093 }
2094
2095 /* Verifying an address messes up the values of $domain and $local_part,
2096 so reset them before returning if this is a RCPT ACL. */
2097
2098 if (addr != NULL)
2099 {
2100 deliver_domain = addr->domain;
2101 deliver_localpart = addr->local_part;
2102 }
2103 return rc;
2104
2105 /* Syntax errors in the verify argument come here. */
2106
2107 BAD_VERIFY:
2108 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2109 "\"helo\", \"header_syntax\", \"header_sender\" or "
2110 "\"reverse_host_lookup\" at start of ACL condition "
2111 "\"verify %s\"", arg);
2112 return ERROR;
2113 }
2114
2115
2116
2117
2118 /*************************************************
2119 * Check argument for control= modifier *
2120 *************************************************/
2121
2122 /* Called from acl_check_condition() below
2123
2124 Arguments:
2125 arg the argument string for control=
2126 pptr set to point to the terminating character
2127 where which ACL we are in
2128 log_msgptr for error messages
2129
2130 Returns: CONTROL_xxx value
2131 */
2132
2133 static int
2134 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
2135 {
2136 int len;
2137 control_def *d;
2138
2139 for (d = controls_list;
2140 d < controls_list + sizeof(controls_list)/sizeof(control_def);
2141 d++)
2142 {
2143 len = Ustrlen(d->name);
2144 if (Ustrncmp(d->name, arg, len) == 0) break;
2145 }
2146
2147 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
2148 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
2149 {
2150 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2151 return CONTROL_ERROR;
2152 }
2153
2154 *pptr = arg + len;
2155 return d->value;
2156 }
2157
2158
2159
2160
2161 /*************************************************
2162 * Return a ratelimit error *
2163 *************************************************/
2164
2165 /* Called from acl_ratelimit() below
2166
2167 Arguments:
2168 log_msgptr for error messages
2169 format format string
2170 ... supplementary arguments
2171 ss ratelimit option name
2172 where ACL_WHERE_xxxx indicating which ACL this is
2173
2174 Returns: ERROR
2175 */
2176
2177 static int
2178 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2179 {
2180 va_list ap;
2181 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2182 va_start(ap, format);
2183 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2184 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2185 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2186 va_end(ap);
2187 *log_msgptr = string_sprintf(
2188 "error in arguments to \"ratelimit\" condition: %s", buffer);
2189 return ERROR;
2190 }
2191
2192
2193
2194
2195 /*************************************************
2196 * Handle rate limiting *
2197 *************************************************/
2198
2199 /* Called by acl_check_condition() below to calculate the result
2200 of the ACL ratelimit condition.
2201
2202 Note that the return value might be slightly unexpected: if the
2203 sender's rate is above the limit then the result is OK. This is
2204 similar to the dnslists condition, and is so that you can write
2205 ACL clauses like: defer ratelimit = 15 / 1h
2206
2207 Arguments:
2208 arg the option string for ratelimit=
2209 where ACL_WHERE_xxxx indicating which ACL this is
2210 log_msgptr for error messages
2211
2212 Returns: OK - Sender's rate is above limit
2213 FAIL - Sender's rate is below limit
2214 DEFER - Problem opening ratelimit database
2215 ERROR - Syntax error in options.
2216 */
2217
2218 static int
2219 acl_ratelimit(uschar *arg, int where, uschar **log_msgptr)
2220 {
2221 double limit, period, count;
2222 uschar *ss;
2223 uschar *key = NULL;
2224 uschar *unique = NULL;
2225 int sep = '/';
2226 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2227 BOOL noupdate = FALSE, badacl = FALSE;
2228 int mode = RATE_PER_WHAT;
2229 int old_pool, rc;
2230 tree_node **anchor, *t;
2231 open_db dbblock, *dbm;
2232 int dbdb_size;
2233 dbdata_ratelimit *dbd;
2234 dbdata_ratelimit_unique *dbdb;
2235 struct timeval tv;
2236
2237 /* Parse the first two options and record their values in expansion
2238 variables. These variables allow the configuration to have informative
2239 error messages based on rate limits obtained from a table lookup. */
2240
2241 /* First is the maximum number of messages per period / maximum burst
2242 size, which must be greater than or equal to zero. Zero is useful for
2243 rate measurement as opposed to rate limiting. */
2244
2245 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2246 if (sender_rate_limit == NULL)
2247 limit = -1.0;
2248 else
2249 {
2250 limit = Ustrtod(sender_rate_limit, &ss);
2251 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2252 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2253 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2254 }
2255 if (limit < 0.0 || *ss != '\0')
2256 return ratelimit_error(log_msgptr,
2257 "\"%s\" is not a positive number", sender_rate_limit);
2258
2259 /* Second is the rate measurement period / exponential smoothing time
2260 constant. This must be strictly greater than zero, because zero leads to
2261 run-time division errors. */
2262
2263 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2264 if (sender_rate_period == NULL) period = -1.0;
2265 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2266 if (period <= 0.0)
2267 return ratelimit_error(log_msgptr,
2268 "\"%s\" is not a time value", sender_rate_period);
2269
2270 /* By default we are counting one of something, but the per_rcpt,
2271 per_byte, and count options can change this. */
2272
2273 count = 1.0;
2274
2275 /* Parse the other options. */
2276
2277 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2278 != NULL)
2279 {
2280 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2281 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2282 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2283 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2284 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2285 else if (strcmpic(ss, US"per_conn") == 0)
2286 {
2287 RATE_SET(mode, PER_CONN);
2288 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2289 badacl = TRUE;
2290 }
2291 else if (strcmpic(ss, US"per_mail") == 0)
2292 {
2293 RATE_SET(mode, PER_MAIL);
2294 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2295 }
2296 else if (strcmpic(ss, US"per_rcpt") == 0)
2297 {
2298 /* If we are running in the RCPT ACL, then we'll count the recipients
2299 one by one, but if we are running when we have accumulated the whole
2300 list then we'll add them all in one batch. */
2301 if (where == ACL_WHERE_RCPT)
2302 RATE_SET(mode, PER_RCPT);
2303 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2304 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2305 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2306 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2307 }
2308 else if (strcmpic(ss, US"per_byte") == 0)
2309 {
2310 /* If we have not yet received the message data and there was no SIZE
2311 declaration on the MAIL comand, then it's safe to just use a value of
2312 zero and let the recorded rate decay as if nothing happened. */
2313 RATE_SET(mode, PER_MAIL);
2314 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2315 else count = message_size < 0 ? 0.0 : (double)message_size;
2316 }
2317 else if (strcmpic(ss, US"per_addr") == 0)
2318 {
2319 RATE_SET(mode, PER_RCPT);
2320 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2321 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2322 }
2323 else if (strncmpic(ss, US"count=", 6) == 0)
2324 {
2325 uschar *e;
2326 count = Ustrtod(ss+6, &e);
2327 if (count < 0.0 || *e != '\0')
2328 return ratelimit_error(log_msgptr,
2329 "\"%s\" is not a positive number", ss);
2330 }
2331 else if (strncmpic(ss, US"unique=", 7) == 0)
2332 unique = string_copy(ss + 7);
2333 else if (key == NULL)
2334 key = string_copy(ss);
2335 else
2336 key = string_sprintf("%s/%s", key, ss);
2337 }
2338
2339 /* Sanity check. When the badacl flag is set the update mode must either
2340 be readonly (which is the default if it is omitted) or, for backwards
2341 compatibility, a combination of noupdate and strict or leaky. */
2342
2343 if (mode == RATE_PER_CLASH)
2344 return ratelimit_error(log_msgptr, "conflicting per_* options");
2345 if (leaky + strict + readonly > 1)
2346 return ratelimit_error(log_msgptr, "conflicting update modes");
2347 if (badacl && (leaky || strict) && !noupdate)
2348 return ratelimit_error(log_msgptr,
2349 "\"%s\" must not have /leaky or /strict option in %s ACL",
2350 ratelimit_option_string[mode], acl_wherenames[where]);
2351
2352 /* Set the default values of any unset options. In readonly mode we
2353 perform the rate computation without any increment so that its value
2354 decays to eventually allow over-limit senders through. */
2355
2356 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2357 if (badacl) readonly = TRUE;
2358 if (readonly) count = 0.0;
2359 if (!strict && !readonly) leaky = TRUE;
2360 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2361
2362 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2363 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2364 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2365 are added to the key because they alter the meaning of the stored data. */
2366
2367 if (key == NULL)
2368 key = (sender_host_address == NULL)? US"" : sender_host_address;
2369
2370 key = string_sprintf("%s/%s/%s%s",
2371 sender_rate_period,
2372 ratelimit_option_string[mode],
2373 unique == NULL ? "" : "unique/",
2374 key);
2375
2376 HDEBUG(D_acl)
2377 debug_printf("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2378
2379 /* See if we have already computed the rate by looking in the relevant tree.
2380 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2381 pool so that they survive across resets. In readonly mode we only remember the
2382 result for the rest of this command in case a later command changes it. After
2383 this bit of logic the code is independent of the per_* mode. */
2384
2385 old_pool = store_pool;
2386
2387 if (readonly)
2388 anchor = &ratelimiters_cmd;
2389 else switch(mode) {
2390 case RATE_PER_CONN:
2391 anchor = &ratelimiters_conn;
2392 store_pool = POOL_PERM;
2393 break;
2394 case RATE_PER_BYTE:
2395 case RATE_PER_MAIL:
2396 case RATE_PER_ALLRCPTS:
2397 anchor = &ratelimiters_mail;
2398 break;
2399 case RATE_PER_ADDR:
2400 case RATE_PER_CMD:
2401 case RATE_PER_RCPT:
2402 anchor = &ratelimiters_cmd;
2403 break;
2404 default:
2405 anchor = NULL; /* silence an "unused" complaint */
2406 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2407 "internal ACL error: unknown ratelimit mode %d", mode);
2408 break;
2409 }
2410
2411 t = tree_search(*anchor, key);
2412 if (t != NULL)
2413 {
2414 dbd = t->data.ptr;
2415 /* The following few lines duplicate some of the code below. */
2416 rc = (dbd->rate < limit)? FAIL : OK;
2417 store_pool = old_pool;
2418 sender_rate = string_sprintf("%.1f", dbd->rate);
2419 HDEBUG(D_acl)
2420 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2421 return rc;
2422 }
2423
2424 /* We aren't using a pre-computed rate, so get a previously recorded rate
2425 from the database, which will be updated and written back if required. */
2426
2427 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2428 if (dbm == NULL)
2429 {
2430 store_pool = old_pool;
2431 sender_rate = NULL;
2432 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2433 *log_msgptr = US"ratelimit database not available";
2434 return DEFER;
2435 }
2436 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2437 dbd = NULL;
2438
2439 gettimeofday(&tv, NULL);
2440
2441 if (dbdb != NULL)
2442 {
2443 /* Locate the basic ratelimit block inside the DB data. */
2444 HDEBUG(D_acl) debug_printf("ratelimit found key in database\n");
2445 dbd = &dbdb->dbd;
2446
2447 /* Forget the old Bloom filter if it is too old, so that we count each
2448 repeating event once per period. We don't simply clear and re-use the old
2449 filter because we want its size to change if the limit changes. Note that
2450 we keep the dbd pointer for copying the rate into the new data block. */
2451
2452 if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period)
2453 {
2454 HDEBUG(D_acl) debug_printf("ratelimit discarding old Bloom filter\n");
2455 dbdb = NULL;
2456 }
2457
2458 /* Sanity check. */
2459
2460 if(unique != NULL && dbdb_size < sizeof(*dbdb))
2461 {
2462 HDEBUG(D_acl) debug_printf("ratelimit discarding undersize Bloom filter\n");
2463 dbdb = NULL;
2464 }
2465 }
2466
2467 /* Allocate a new data block if the database lookup failed
2468 or the Bloom filter passed its age limit. */
2469
2470 if (dbdb == NULL)
2471 {
2472 if (unique == NULL)
2473 {
2474 /* No Bloom filter. This basic ratelimit block is initialized below. */
2475 HDEBUG(D_acl) debug_printf("ratelimit creating new rate data block\n");
2476 dbdb_size = sizeof(*dbd);
2477 dbdb = store_get(dbdb_size);
2478 }
2479 else
2480 {
2481 int extra;
2482 HDEBUG(D_acl) debug_printf("ratelimit creating new Bloom filter\n");
2483
2484 /* See the long comment below for an explanation of the magic number 2.
2485 The filter has a minimum size in case the rate limit is very small;
2486 this is determined by the definition of dbdata_ratelimit_unique. */
2487
2488 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2489 if (extra < 0) extra = 0;
2490 dbdb_size = sizeof(*dbdb) + extra;
2491 dbdb = store_get(dbdb_size);
2492 dbdb->bloom_epoch = tv.tv_sec;
2493 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2494 memset(dbdb->bloom, 0, dbdb->bloom_size);
2495
2496 /* Preserve any basic ratelimit data (which is our longer-term memory)
2497 by copying it from the discarded block. */
2498
2499 if (dbd != NULL)
2500 {
2501 dbdb->dbd = *dbd;
2502 dbd = &dbdb->dbd;
2503 }
2504 }
2505 }
2506
2507 /* If we are counting unique events, find out if this event is new or not.
2508 If the client repeats the event during the current period then it should be
2509 counted. We skip this code in readonly mode for efficiency, because any
2510 changes to the filter will be discarded and because count is already set to
2511 zero. */
2512
2513 if (unique != NULL && !readonly)
2514 {
2515 /* We identify unique events using a Bloom filter. (You can find my
2516 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2517 With the per_addr option, an "event" is a recipient address, though the
2518 user can use the unique option to define their own events. We only count
2519 an event if we have not seen it before.
2520
2521 We size the filter according to the rate limit, which (in leaky mode)
2522 is the limit on the population of the filter. We allow 16 bits of space
2523 per entry (see the construction code above) and we set (up to) 8 of them
2524 when inserting an element (see the loop below). The probability of a false
2525 positive (an event we have not seen before but which we fail to count) is
2526
2527 size = limit * 16
2528 numhash = 8
2529 allzero = exp(-numhash * pop / size)
2530 = exp(-0.5 * pop / limit)
2531 fpr = pow(1 - allzero, numhash)
2532
2533 For senders at the limit the fpr is 0.06% or 1 in 1700
2534 and for senders at half the limit it is 0.0006% or 1 in 170000
2535
2536 In strict mode the Bloom filter can fill up beyond the normal limit, in
2537 which case the false positive rate will rise. This means that the
2538 measured rate for very fast senders can bogusly drop off after a while.
2539
2540 At twice the limit, the fpr is 2.5% or 1 in 40
2541 At four times the limit, it is 31% or 1 in 3.2
2542
2543 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2544 decay below the limit, and if this is more than one then the Bloom filter
2545 will be discarded before the decay gets that far. The false positive rate
2546 at this threshold is 9.3% or 1 in 10.7. */
2547
2548 BOOL seen;
2549 unsigned n, hash, hinc;
2550 uschar md5sum[16];
2551 md5 md5info;
2552
2553 /* Instead of using eight independent hash values, we combine two values
2554 using the formula h1 + n * h2. This does not harm the Bloom filter's
2555 performance, and means the amount of hash we need is independent of the
2556 number of bits we set in the filter. */
2557
2558 md5_start(&md5info);
2559 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2560 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2561 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2562
2563 /* Scan the bits corresponding to this event. A zero bit means we have
2564 not seen it before. Ensure all bits are set to record this event. */
2565
2566 HDEBUG(D_acl) debug_printf("ratelimit checking uniqueness of %s\n", unique);
2567
2568 seen = TRUE;
2569 for (n = 0; n < 8; n++, hash += hinc)
2570 {
2571 int bit = 1 << (hash % 8);
2572 int byte = (hash / 8) % dbdb->bloom_size;
2573 if ((dbdb->bloom[byte] & bit) == 0)
2574 {
2575 dbdb->bloom[byte] |= bit;
2576 seen = FALSE;
2577 }
2578 }
2579
2580 /* If this event has occurred before, do not count it. */
2581
2582 if (seen)
2583 {
2584 HDEBUG(D_acl) debug_printf("ratelimit event found in Bloom filter\n");
2585 count = 0.0;
2586 }
2587 else
2588 HDEBUG(D_acl) debug_printf("ratelimit event added to Bloom filter\n");
2589 }
2590
2591 /* If there was no previous ratelimit data block for this key, initialize
2592 the new one, otherwise update the block from the database. The initial rate
2593 is what would be computed by the code below for an infinite interval. */
2594
2595 if (dbd == NULL)
2596 {
2597 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's rate data\n");
2598 dbd = &dbdb->dbd;
2599 dbd->time_stamp = tv.tv_sec;
2600 dbd->time_usec = tv.tv_usec;
2601 dbd->rate = count;
2602 }
2603 else
2604 {
2605 /* The smoothed rate is computed using an exponentially weighted moving
2606 average adjusted for variable sampling intervals. The standard EWMA for
2607 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2608 where f() is the measured value and f'() is the smoothed value.
2609
2610 Old data decays out of the smoothed value exponentially, such that data n
2611 samples old is multiplied by a^n. The exponential decay time constant p
2612 is defined such that data p samples old is multiplied by 1/e, which means
2613 that a = exp(-1/p). We can maintain the same time constant for a variable
2614 sampling interval i by using a = exp(-i/p).
2615
2616 The rate we are measuring is messages per period, suitable for directly
2617 comparing with the limit. The average rate between now and the previous
2618 message is period / interval, which we feed into the EWMA as the sample.
2619
2620 It turns out that the number of messages required for the smoothed rate
2621 to reach the limit when they are sent in a burst is equal to the limit.
2622 This can be seen by analysing the value of the smoothed rate after N
2623 messages sent at even intervals. Let k = (1 - a) * p/i
2624
2625 rate_1 = (1 - a) * p/i + a * rate_0
2626 = k + a * rate_0
2627 rate_2 = k + a * rate_1
2628 = k + a * k + a^2 * rate_0
2629 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2630 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2631 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2632 = rate_0 * a^N + p/i * (1 - a^N)
2633
2634 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2635
2636 rate_N = p/i + (rate_0 - p/i) * a^N
2637 a^N = (rate_N - p/i) / (rate_0 - p/i)
2638 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2639 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2640
2641 Numerical analysis of the above equation, setting the computed rate to
2642 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2643 rates, p/i, the number of messages N = limit. So limit serves as both the
2644 maximum rate measured in messages per period, and the maximum number of
2645 messages that can be sent in a fast burst. */
2646
2647 double this_time = (double)tv.tv_sec
2648 + (double)tv.tv_usec / 1000000.0;
2649 double prev_time = (double)dbd->time_stamp
2650 + (double)dbd->time_usec / 1000000.0;
2651
2652 /* We must avoid division by zero, and deal gracefully with the clock going
2653 backwards. If we blunder ahead when time is in reverse then the computed
2654 rate will be bogus. To be safe we clamp interval to a very small number. */
2655
2656 double interval = this_time - prev_time <= 0.0 ? 1e-9
2657 : this_time - prev_time;
2658
2659 double i_over_p = interval / period;
2660 double a = exp(-i_over_p);
2661
2662 /* Combine the instantaneous rate (period / interval) with the previous rate
2663 using the smoothing factor a. In order to measure sized events, multiply the
2664 instantaneous rate by the count of bytes or recipients etc. */
2665
2666 dbd->time_stamp = tv.tv_sec;
2667 dbd->time_usec = tv.tv_usec;
2668 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2669
2670 /* When events are very widely spaced the computed rate tends towards zero.
2671 Although this is accurate it turns out not to be useful for our purposes,
2672 especially when the first event after a long silence is the start of a spam
2673 run. A more useful model is that the rate for an isolated event should be the
2674 size of the event per the period size, ignoring the lack of events outside
2675 the current period and regardless of where the event falls in the period. So,
2676 if the interval was so long that the calculated rate is unhelpfully small, we
2677 re-intialize the rate. In the absence of higher-rate bursts, the condition
2678 below is true if the interval is greater than the period. */
2679
2680 if (dbd->rate < count) dbd->rate = count;
2681 }
2682
2683 /* Clients sending at the limit are considered to be over the limit.
2684 This matters for edge cases such as a limit of zero, when the client
2685 should be completely blocked. */
2686
2687 rc = (dbd->rate < limit)? FAIL : OK;
2688
2689 /* Update the state if the rate is low or if we are being strict. If we
2690 are in leaky mode and the sender's rate is too high, we do not update
2691 the recorded rate in order to avoid an over-aggressive sender's retry
2692 rate preventing them from getting any email through. If readonly is set,
2693 neither leaky nor strict are set, so we do not do any updates. */
2694
2695 if ((rc == FAIL && leaky) || strict)
2696 {
2697 dbfn_write(dbm, key, dbdb, dbdb_size);
2698 HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
2699 }
2700 else
2701 {
2702 HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
2703 readonly? "readonly mode" : "over the limit, but leaky");
2704 }
2705
2706 dbfn_close(dbm);
2707
2708 /* Store the result in the tree for future reference. */
2709
2710 t = store_get(sizeof(tree_node) + Ustrlen(key));
2711 t->data.ptr = dbd;
2712 Ustrcpy(t->name, key);
2713 (void)tree_insertnode(anchor, t);
2714
2715 /* We create the formatted version of the sender's rate very late in
2716 order to ensure that it is done using the correct storage pool. */
2717
2718 store_pool = old_pool;
2719 sender_rate = string_sprintf("%.1f", dbd->rate);
2720
2721 HDEBUG(D_acl)
2722 debug_printf("ratelimit computed rate %s\n", sender_rate);
2723
2724 return rc;
2725 }
2726
2727
2728
2729 /*************************************************
2730 * Handle conditions/modifiers on an ACL item *
2731 *************************************************/
2732
2733 /* Called from acl_check() below.
2734
2735 Arguments:
2736 verb ACL verb
2737 cb ACL condition block - if NULL, result is OK
2738 where where called from
2739 addr the address being checked for RCPT, or NULL
2740 level the nesting level
2741 epp pointer to pass back TRUE if "endpass" encountered
2742 (applies only to "accept" and "discard")
2743 user_msgptr user message pointer
2744 log_msgptr log message pointer
2745 basic_errno pointer to where to put verify error
2746
2747 Returns: OK - all conditions are met
2748 DISCARD - an "acl" condition returned DISCARD - only allowed
2749 for "accept" or "discard" verbs
2750 FAIL - at least one condition fails
2751 FAIL_DROP - an "acl" condition returned FAIL_DROP
2752 DEFER - can't tell at the moment (typically, lookup defer,
2753 but can be temporary callout problem)
2754 ERROR - ERROR from nested ACL or expansion failure or other
2755 error
2756 */
2757
2758 static int
2759 acl_check_condition(int verb, acl_condition_block *cb, int where,
2760 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2761 uschar **log_msgptr, int *basic_errno)
2762 {
2763 uschar *user_message = NULL;
2764 uschar *log_message = NULL;
2765 uschar *debug_tag = NULL;
2766 uschar *debug_opts = NULL;
2767 uschar *p = NULL;
2768 int rc = OK;
2769 #ifdef WITH_CONTENT_SCAN
2770 int sep = '/';
2771 #endif
2772
2773 for (; cb != NULL; cb = cb->next)
2774 {
2775 uschar *arg;
2776 int control_type;
2777
2778 /* The message and log_message items set up messages to be used in
2779 case of rejection. They are expanded later. */
2780
2781 if (cb->type == ACLC_MESSAGE)
2782 {
2783 user_message = cb->arg;
2784 continue;
2785 }
2786
2787 if (cb->type == ACLC_LOG_MESSAGE)
2788 {
2789 log_message = cb->arg;
2790 continue;
2791 }
2792
2793 /* The endpass "condition" just sets a flag to show it occurred. This is
2794 checked at compile time to be on an "accept" or "discard" item. */
2795
2796 if (cb->type == ACLC_ENDPASS)
2797 {
2798 *epp = TRUE;
2799 continue;
2800 }
2801
2802 /* For other conditions and modifiers, the argument is expanded now for some
2803 of them, but not for all, because expansion happens down in some lower level
2804 checking functions in some cases. */
2805
2806 if (cond_expand_at_top[cb->type])
2807 {
2808 arg = expand_string(cb->arg);
2809 if (arg == NULL)
2810 {
2811 if (expand_string_forcedfail) continue;
2812 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2813 cb->arg, expand_string_message);
2814 return search_find_defer? DEFER : ERROR;
2815 }
2816 }
2817 else arg = cb->arg;
2818
2819 /* Show condition, and expanded condition if it's different */
2820
2821 HDEBUG(D_acl)
2822 {
2823 int lhswidth = 0;
2824 debug_printf("check %s%s %n",
2825 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2826 conditions[cb->type], &lhswidth);
2827
2828 if (cb->type == ACLC_SET)
2829 {
2830 debug_printf("acl_%s ", cb->u.varname);
2831 lhswidth += 5 + Ustrlen(cb->u.varname);
2832 }
2833
2834 debug_printf("= %s\n", cb->arg);
2835
2836 if (arg != cb->arg)
2837 debug_printf("%.*s= %s\n", lhswidth,
2838 US" ", CS arg);
2839 }
2840
2841 /* Check that this condition makes sense at this time */
2842
2843 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2844 {
2845 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2846 cond_modifiers[cb->type]? "use" : "test",
2847 conditions[cb->type], acl_wherenames[where]);
2848 return ERROR;
2849 }
2850
2851 /* Run the appropriate test for each condition, or take the appropriate
2852 action for the remaining modifiers. */
2853
2854 switch(cb->type)
2855 {
2856 case ACLC_ADD_HEADER:
2857 setup_header(arg);
2858 break;
2859
2860 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2861 "discard" verb. */
2862
2863 case ACLC_ACL:
2864 rc = acl_check_wargs(where, addr, arg, level+1, user_msgptr, log_msgptr);
2865 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2866 {
2867 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2868 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2869 verbs[verb]);
2870 return ERROR;
2871 }
2872 break;
2873
2874 case ACLC_AUTHENTICATED:
2875 rc = (sender_host_authenticated == NULL)? FAIL :
2876 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2877 TRUE, NULL);
2878 break;
2879
2880 #ifdef EXPERIMENTAL_BRIGHTMAIL
2881 case ACLC_BMI_OPTIN:
2882 {
2883 int old_pool = store_pool;
2884 store_pool = POOL_PERM;
2885 bmi_current_optin = string_copy(arg);
2886 store_pool = old_pool;
2887 }
2888 break;
2889 #endif
2890
2891 case ACLC_CONDITION:
2892 /* The true/false parsing here should be kept in sync with that used in
2893 expand.c when dealing with ECOND_BOOL so that we don't have too many
2894 different definitions of what can be a boolean. */
2895 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2896 rc = (Uatoi(arg) == 0)? FAIL : OK;
2897 else
2898 rc = (strcmpic(arg, US"no") == 0 ||
2899 strcmpic(arg, US"false") == 0)? FAIL :
2900 (strcmpic(arg, US"yes") == 0 ||
2901 strcmpic(arg, US"true") == 0)? OK : DEFER;
2902 if (rc == DEFER)
2903 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2904 break;
2905
2906 case ACLC_CONTINUE: /* Always succeeds */
2907 break;
2908
2909 case ACLC_CONTROL:
2910 control_type = decode_control(arg, &p, where, log_msgptr);
2911
2912 /* Check if this control makes sense at this time */
2913
2914 if ((control_forbids[control_type] & (1 << where)) != 0)
2915 {
2916 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2917 controls[control_type], acl_wherenames[where]);
2918 return ERROR;
2919 }
2920
2921 switch(control_type)
2922 {
2923 case CONTROL_AUTH_UNADVERTISED:
2924 allow_auth_unadvertised = TRUE;
2925 break;
2926
2927 #ifdef EXPERIMENTAL_BRIGHTMAIL
2928 case CONTROL_BMI_RUN:
2929 bmi_run = 1;
2930 break;
2931 #endif
2932
2933 #ifndef DISABLE_DKIM
2934 case CONTROL_DKIM_VERIFY:
2935 dkim_disable_verify = TRUE;
2936 break;
2937 #endif
2938
2939 case CONTROL_DSCP:
2940 if (*p == '/')
2941 {
2942 int fd, af, level, optname, value;
2943 /* If we are acting on stdin, the setsockopt may fail if stdin is not
2944 a socket; we can accept that, we'll just debug-log failures anyway. */
2945 fd = fileno(smtp_in);
2946 af = ip_get_address_family(fd);
2947 if (af < 0)
2948 {
2949 HDEBUG(D_acl)
2950 debug_printf("smtp input is probably not a socket [%s], not setting DSCP\n",
2951 strerror(errno));
2952 break;
2953 }
2954 if (dscp_lookup(p+1, af, &level, &optname, &value))
2955 {
2956 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
2957 {
2958 HDEBUG(D_acl) debug_printf("failed to set input DSCP[%s]: %s\n",
2959 p+1, strerror(errno));
2960 }
2961 else
2962 {
2963 HDEBUG(D_acl) debug_printf("set input DSCP to \"%s\"\n", p+1);
2964 }
2965 }
2966 else
2967 {
2968 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
2969 return ERROR;
2970 }
2971 }
2972 else
2973 {
2974 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2975 return ERROR;
2976 }
2977 break;
2978
2979 case CONTROL_ERROR:
2980 return ERROR;
2981
2982 case CONTROL_CASEFUL_LOCAL_PART:
2983 deliver_localpart = addr->cc_local_part;
2984 break;
2985
2986 case CONTROL_CASELOWER_LOCAL_PART:
2987 deliver_localpart = addr->lc_local_part;
2988 break;
2989
2990 case CONTROL_ENFORCE_SYNC:
2991 smtp_enforce_sync = TRUE;
2992 break;
2993
2994 case CONTROL_NO_ENFORCE_SYNC:
2995 smtp_enforce_sync = FALSE;
2996 break;
2997
2998 #ifdef WITH_CONTENT_SCAN
2999 case CONTROL_NO_MBOX_UNSPOOL:
3000 no_mbox_unspool = TRUE;
3001 break;
3002 #endif
3003
3004 case CONTROL_NO_MULTILINE:
3005 no_multiline_responses = TRUE;
3006 break;
3007
3008 case CONTROL_NO_PIPELINING:
3009 pipelining_enable = FALSE;
3010 break;
3011
3012 case CONTROL_NO_DELAY_FLUSH:
3013 disable_delay_flush = TRUE;
3014 break;
3015
3016 case CONTROL_NO_CALLOUT_FLUSH:
3017 disable_callout_flush = TRUE;
3018 break;
3019
3020 case CONTROL_FAKEDEFER:
3021 case CONTROL_FAKEREJECT:
3022 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3023 if (*p == '/')
3024 {
3025 uschar *pp = p + 1;
3026 while (*pp != 0) pp++;
3027 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3028 p = pp;
3029 }
3030 else
3031 {
3032 /* Explicitly reset to default string */
3033 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).";
3034 }
3035 break;
3036
3037 case CONTROL_FREEZE:
3038 deliver_freeze = TRUE;
3039 deliver_frozen_at = time(NULL);
3040 freeze_tell = freeze_tell_config; /* Reset to configured value */
3041 if (Ustrncmp(p, "/no_tell", 8) == 0)
3042 {
3043 p += 8;
3044 freeze_tell = NULL;
3045 }
3046 if (*p != 0)
3047 {
3048 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3049 return ERROR;
3050 }
3051 break;
3052
3053 case CONTROL_QUEUE_ONLY:
3054 queue_only_policy = TRUE;
3055 break;
3056
3057 case CONTROL_SUBMISSION:
3058 originator_name = US"";
3059 submission_mode = TRUE;
3060 while (*p == '/')
3061 {
3062 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3063 {
3064 p += 14;
3065 active_local_sender_retain = TRUE;
3066 active_local_from_check = FALSE;
3067 }
3068 else if (Ustrncmp(p, "/domain=", 8) == 0)
3069 {
3070 uschar *pp = p + 8;
3071 while (*pp != 0 && *pp != '/') pp++;
3072 submission_domain = string_copyn(p+8, pp-p-8);
3073 p = pp;
3074 }
3075 /* The name= option must be last, because it swallows the rest of
3076 the string. */
3077 else if (Ustrncmp(p, "/name=", 6) == 0)
3078 {
3079 uschar *pp = p + 6;
3080 while (*pp != 0) pp++;
3081 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3082 big_buffer, big_buffer_size));
3083 p = pp;
3084 }
3085 else break;
3086 }
3087 if (*p != 0)
3088 {
3089 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3090 return ERROR;
3091 }
3092 break;
3093
3094 case CONTROL_DEBUG:
3095 while (*p == '/')
3096 {
3097 if (Ustrncmp(p, "/tag=", 5) == 0)
3098 {
3099 uschar *pp = p + 5;
3100 while (*pp != '\0' && *pp != '/') pp++;
3101 debug_tag = string_copyn(p+5, pp-p-5);
3102 p = pp;
3103 }
3104 else if (Ustrncmp(p, "/opts=", 6) == 0)
3105 {
3106 uschar *pp = p + 6;
3107 while (*pp != '\0' && *pp != '/') pp++;
3108 debug_opts = string_copyn(p+6, pp-p-6);
3109 p = pp;
3110 }
3111 }
3112 debug_logging_activate(debug_tag, debug_opts);
3113 break;
3114
3115 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3116 suppress_local_fixups = TRUE;
3117 break;
3118
3119 case CONTROL_CUTTHROUGH_DELIVERY:
3120 if (deliver_freeze)
3121 {
3122 *log_msgptr = string_sprintf("\"control=%s\" on frozen item", arg);
3123 return ERROR;
3124 }
3125 if (queue_only_policy)
3126 {
3127 *log_msgptr = string_sprintf("\"control=%s\" on queue-only item", arg);
3128 return ERROR;
3129 }
3130 cutthrough_delivery = TRUE;
3131 break;
3132 }
3133 break;
3134
3135 #ifdef EXPERIMENTAL_DCC
3136 case ACLC_DCC:
3137 {
3138 /* Seperate the regular expression and any optional parameters. */
3139 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3140 /* Run the dcc backend. */
3141 rc = dcc_process(&ss);
3142 /* Modify return code based upon the existance of options. */
3143 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3144 != NULL) {
3145 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3146 {
3147 /* FAIL so that the message is passed to the next ACL */
3148 rc = FAIL;
3149 }
3150 }
3151 }
3152 break;
3153 #endif
3154
3155 #ifdef WITH_CONTENT_SCAN
3156 case ACLC_DECODE:
3157 rc = mime_decode(&arg);
3158 break;
3159 #endif
3160
3161 case ACLC_DELAY:
3162 {
3163 int delay = readconf_readtime(arg, 0, FALSE);
3164 if (delay < 0)
3165 {
3166 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3167 "modifier: \"%s\" is not a time value", arg);
3168 return ERROR;
3169 }
3170 else
3171 {
3172 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
3173 delay);
3174 if (host_checking)
3175 {
3176 HDEBUG(D_acl)
3177 debug_printf("delay skipped in -bh checking mode\n");
3178 }
3179
3180 /* It appears to be impossible to detect that a TCP/IP connection has
3181 gone away without reading from it. This means that we cannot shorten
3182 the delay below if the client goes away, because we cannot discover
3183 that the client has closed its end of the connection. (The connection
3184 is actually in a half-closed state, waiting for the server to close its
3185 end.) It would be nice to be able to detect this state, so that the
3186 Exim process is not held up unnecessarily. However, it seems that we
3187 can't. The poll() function does not do the right thing, and in any case
3188 it is not always available.
3189
3190 NOTE 1: If ever this state of affairs changes, remember that we may be
3191 dealing with stdin/stdout here, in addition to TCP/IP connections.
3192 Also, delays may be specified for non-SMTP input, where smtp_out and
3193 smtp_in will be NULL. Whatever is done must work in all cases.
3194
3195 NOTE 2: The added feature of flushing the output before a delay must
3196 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3197 */
3198
3199 else
3200 {
3201 if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush();
3202 while (delay > 0) delay = sleep(delay);
3203 }
3204 }
3205 }
3206 break;
3207
3208 #ifdef WITH_OLD_DEMIME
3209 case ACLC_DEMIME:
3210 rc = demime(&arg);
3211 break;
3212 #endif
3213
3214 #ifndef DISABLE_DKIM
3215 case ACLC_DKIM_SIGNER:
3216 if (dkim_cur_signer != NULL)
3217 rc = match_isinlist(dkim_cur_signer,
3218 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3219 else
3220 rc = FAIL;
3221 break;
3222
3223 case ACLC_DKIM_STATUS:
3224 rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS),
3225 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3226 break;
3227 #endif
3228
3229 case ACLC_DNSLISTS:
3230 rc = verify_check_dnsbl(&arg);
3231 break;
3232
3233 case ACLC_DOMAINS:
3234 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3235 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
3236 break;
3237
3238 /* The value in tls_cipher is the full cipher name, for example,
3239 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3240 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3241 what may in practice come out of the SSL library - which at the time of
3242 writing is poorly documented. */
3243
3244 case ACLC_ENCRYPTED:
3245 if (tls_in.cipher == NULL) rc = FAIL; else
3246 {
3247 uschar *endcipher = NULL;
3248 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3249 if (cipher == NULL) cipher = tls_in.cipher; else
3250 {
3251 endcipher = Ustrchr(++cipher, ':');
3252 if (endcipher != NULL) *endcipher = 0;
3253 }
3254 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3255 if (endcipher != NULL) *endcipher = ':';
3256 }
3257 break;
3258
3259 /* Use verify_check_this_host() instead of verify_check_host() so that
3260 we can pass over &host_data to catch any looked up data. Once it has been
3261 set, it retains its value so that it's still there if another ACL verb
3262 comes through here and uses the cache. However, we must put it into
3263 permanent store in case it is also expected to be used in a subsequent
3264 message in the same SMTP connection. */
3265
3266 case ACLC_HOSTS:
3267 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3268 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
3269 if (host_data != NULL) host_data = string_copy_malloc(host_data);
3270 break;
3271
3272 case ACLC_LOCAL_PARTS:
3273 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3274 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3275 &deliver_localpart_data);
3276 break;
3277
3278 case ACLC_LOG_REJECT_TARGET:
3279 {
3280 int logbits = 0;
3281 int sep = 0;
3282 uschar *s = arg;
3283 uschar *ss;
3284 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
3285 != NULL)
3286 {
3287 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3288 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3289 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3290 else
3291 {
3292 logbits |= LOG_MAIN|LOG_REJECT;
3293 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3294 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3295 }
3296 }
3297 log_reject_target = logbits;
3298 }
3299 break;
3300
3301 case ACLC_LOGWRITE:
3302 {
3303 int logbits = 0;
3304 uschar *s = arg;
3305 if (*s == ':')
3306 {
3307 s++;
3308 while (*s != ':')
3309 {
3310 if (Ustrncmp(s, "main", 4) == 0)
3311 { logbits |= LOG_MAIN; s += 4; }
3312 else if (Ustrncmp(s, "panic", 5) == 0)
3313 { logbits |= LOG_PANIC; s += 5; }
3314 else if (Ustrncmp(s, "reject", 6) == 0)
3315 { logbits |= LOG_REJECT; s += 6; }
3316 else
3317 {
3318 logbits = LOG_MAIN|LOG_PANIC;
3319 s = string_sprintf(":unknown log name in \"%s\" in "
3320 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3321 }
3322 if (*s == ',') s++;
3323 }
3324 s++;
3325 }
3326 while (isspace(*s)) s++;
3327
3328
3329 if (logbits == 0) logbits = LOG_MAIN;
3330 log_write(0, logbits, "%s", string_printing(s));
3331 }
3332 break;
3333
3334 #ifdef WITH_CONTENT_SCAN
3335 case ACLC_MALWARE:
3336 {
3337 /* Separate the regular expression and any optional parameters. */
3338 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3339 /* Run the malware backend. */
3340 rc = malware(&ss);
3341 /* Modify return code based upon the existance of options. */
3342 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3343 != NULL) {
3344 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3345 {
3346 /* FAIL so that the message is passed to the next ACL */
3347 rc = FAIL;
3348 }
3349 }
3350 }
3351 break;
3352
3353 case ACLC_MIME_REGEX:
3354 rc = mime_regex(&arg);
3355 break;
3356 #endif
3357
3358 case ACLC_RATELIMIT:
3359 rc = acl_ratelimit(arg, where, log_msgptr);
3360 break;
3361
3362 case ACLC_RECIPIENTS:
3363 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3364 &recipient_data);
3365 break;
3366
3367 #ifdef WITH_CONTENT_SCAN
3368 case ACLC_REGEX:
3369 rc = regex(&arg);
3370 break;
3371 #endif
3372
3373 case ACLC_REMOVE_HEADER:
3374 setup_remove_header(arg);
3375 break;
3376
3377 case ACLC_SENDER_DOMAINS:
3378 {
3379 uschar *sdomain;
3380 sdomain = Ustrrchr(sender_address, '@');
3381 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
3382 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3383 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3384 }
3385 break;
3386
3387 case ACLC_SENDERS:
3388 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
3389 sender_address_cache, -1, 0, &sender_data);
3390 break;
3391
3392 /* Connection variables must persist forever */
3393
3394 case ACLC_SET:
3395 {
3396 int old_pool = store_pool;
3397 if (cb->u.varname[0] == 'c') store_pool = POOL_PERM;
3398 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3399 store_pool = old_pool;
3400 }
3401 break;
3402
3403 #ifdef WITH_CONTENT_SCAN
3404 case ACLC_SPAM:
3405 {
3406 /* Seperate the regular expression and any optional parameters. */
3407 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3408 /* Run the spam backend. */
3409 rc = spam(&ss);
3410 /* Modify return code based upon the existance of options. */
3411 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3412 != NULL) {
3413 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3414 {
3415 /* FAIL so that the message is passed to the next ACL */
3416 rc = FAIL;
3417 }
3418 }
3419 }
3420 break;
3421 #endif
3422
3423 #ifdef EXPERIMENTAL_SPF
3424 case ACLC_SPF:
3425 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3426 break;
3427 case ACLC_SPF_GUESS:
3428 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3429 break;
3430 #endif
3431
3432 /* If the verb is WARN, discard any user message from verification, because
3433 such messages are SMTP responses, not header additions. The latter come
3434 only from explicit "message" modifiers. However, put the user message into
3435 $acl_verify_message so it can be used in subsequent conditions or modifiers
3436 (until something changes it). */
3437
3438 case ACLC_VERIFY:
3439 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3440 acl_verify_message = *user_msgptr;
3441 if (verb == ACL_WARN) *user_msgptr = NULL;
3442 break;
3443
3444 default:
3445 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3446 "condition %d", cb->type);
3447 break;
3448 }
3449
3450 /* If a condition was negated, invert OK/FAIL. */
3451
3452 if (!cond_modifiers[cb->type] && cb->u.negated)
3453 {
3454 if (rc == OK) rc = FAIL;
3455 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3456 }
3457
3458 if (rc != OK) break; /* Conditions loop */
3459 }
3460
3461
3462 /* If the result is the one for which "message" and/or "log_message" are used,
3463 handle the values of these modifiers. If there isn't a log message set, we make
3464 it the same as the user message.
3465
3466 "message" is a user message that will be included in an SMTP response. Unless
3467 it is empty, it overrides any previously set user message.
3468
3469 "log_message" is a non-user message, and it adds to any existing non-user
3470 message that is already set.
3471
3472 Most verbs have but a single return for which the messages are relevant, but
3473 for "discard", it's useful to have the log message both when it succeeds and
3474 when it fails. For "accept", the message is used in the OK case if there is no
3475 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3476 present. */
3477
3478 if (*epp && rc == OK) user_message = NULL;
3479
3480 if (((1<<rc) & msgcond[verb]) != 0)
3481 {
3482 uschar *expmessage;
3483 uschar *old_user_msgptr = *user_msgptr;
3484 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3485
3486 /* If the verb is "warn", messages generated by conditions (verification or
3487 nested ACLs) are always discarded. This also happens for acceptance verbs
3488 when they actually do accept. Only messages specified at this level are used.
3489 However, the value of an existing message is available in $acl_verify_message
3490 during expansions. */
3491
3492 if (verb == ACL_WARN ||
3493 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3494 *log_msgptr = *user_msgptr = NULL;
3495
3496 if (user_message != NULL)
3497 {
3498 acl_verify_message = old_user_msgptr;
3499 expmessage = expand_string(user_message);
3500 if (expmessage == NULL)
3501 {
3502 if (!expand_string_forcedfail)
3503 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3504 user_message, expand_string_message);
3505 }
3506 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3507 }
3508
3509 if (log_message != NULL)
3510 {
3511 acl_verify_message = old_log_msgptr;
3512 expmessage = expand_string(log_message);
3513 if (expmessage == NULL)
3514 {
3515 if (!expand_string_forcedfail)
3516 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3517 log_message, expand_string_message);
3518 }
3519 else if (expmessage[0] != 0)
3520 {
3521 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3522 string_sprintf("%s: %s", expmessage, *log_msgptr);
3523 }
3524 }
3525
3526 /* If no log message, default it to the user message */
3527
3528 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3529 }
3530
3531 acl_verify_message = NULL;
3532 return rc;
3533 }
3534
3535
3536
3537
3538
3539 /*************************************************
3540 * Get line from a literal ACL *
3541 *************************************************/
3542
3543 /* This function is passed to acl_read() in order to extract individual lines
3544 of a literal ACL, which we access via static pointers. We can destroy the
3545 contents because this is called only once (the compiled ACL is remembered).
3546
3547 This code is intended to treat the data in the same way as lines in the main
3548 Exim configuration file. That is:
3549
3550 . Leading spaces are ignored.
3551
3552 . A \ at the end of a line is a continuation - trailing spaces after the \
3553 are permitted (this is because I don't believe in making invisible things
3554 significant). Leading spaces on the continued part of a line are ignored.
3555
3556 . Physical lines starting (significantly) with # are totally ignored, and
3557 may appear within a sequence of backslash-continued lines.
3558
3559 . Blank lines are ignored, but will end a sequence of continuations.
3560
3561 Arguments: none
3562 Returns: a pointer to the next line
3563 */
3564
3565
3566 static uschar *acl_text; /* Current pointer in the text */
3567 static uschar *acl_text_end; /* Points one past the terminating '0' */
3568
3569
3570 static uschar *
3571 acl_getline(void)
3572 {
3573 uschar *yield;
3574
3575 /* This loop handles leading blank lines and comments. */
3576
3577 for(;;)
3578 {
3579 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3580 if (*acl_text == 0) return NULL; /* No more data */
3581 yield = acl_text; /* Potential data line */
3582
3583 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3584
3585 /* If we hit the end before a newline, we have the whole logical line. If
3586 it's a comment, there's no more data to be given. Otherwise, yield it. */
3587
3588 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3589
3590 /* After reaching a newline, end this loop if the physical line does not
3591 start with '#'. If it does, it's a comment, and the loop continues. */
3592
3593 if (*yield != '#') break;
3594 }
3595
3596 /* This loop handles continuations. We know we have some real data, ending in
3597 newline. See if there is a continuation marker at the end (ignoring trailing
3598 white space). We know that *yield is not white space, so no need to test for
3599 cont > yield in the backwards scanning loop. */
3600
3601 for(;;)
3602 {
3603 uschar *cont;
3604 for (cont = acl_text - 1; isspace(*cont); cont--);
3605
3606 /* If no continuation follows, we are done. Mark the end of the line and
3607 return it. */
3608
3609 if (*cont != '\\')
3610 {
3611 *acl_text++ = 0;
3612 return yield;
3613 }
3614
3615 /* We have encountered a continuation. Skip over whitespace at the start of
3616 the next line, and indeed the whole of the next line or lines if they are
3617 comment lines. */
3618
3619 for (;;)
3620 {
3621 while (*(++acl_text) == ' ' || *acl_text == '\t');
3622 if (*acl_text != '#') break;
3623 while (*(++acl_text) != 0 && *acl_text != '\n');
3624 }
3625
3626 /* We have the start of a continuation line. Move all the rest of the data
3627 to join onto the previous line, and then find its end. If the end is not a
3628 newline, we are done. Otherwise loop to look for another continuation. */
3629
3630 memmove(cont, acl_text, acl_text_end - acl_text);
3631 acl_text_end -= acl_text - cont;
3632 acl_text = cont;
3633 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3634 if (*acl_text == 0) return yield;
3635 }
3636
3637 /* Control does not reach here */
3638 }
3639
3640
3641
3642
3643
3644 /*************************************************
3645 * Check access using an ACL *
3646 *************************************************/
3647
3648 /* This function is called from address_check. It may recurse via
3649 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3650 passed as a string which is expanded. A forced failure implies no access check
3651 is required. If the result is a single word, it is taken as the name of an ACL
3652 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3653 text, complete with newlines, and parsed as such. In both cases, the ACL check
3654 is then run. This function uses an auxiliary function for acl_read() to call
3655 for reading individual lines of a literal ACL. This is acl_getline(), which
3656 appears immediately above.
3657
3658 Arguments:
3659 where where called from
3660 addr address item when called from RCPT; otherwise NULL
3661 s the input string; NULL is the same as an empty ACL => DENY
3662 level the nesting level
3663 user_msgptr where to put a user error (for SMTP response)
3664 log_msgptr where to put a logging message (not for SMTP response)
3665
3666 Returns: OK access is granted
3667 DISCARD access is apparently granted...
3668 FAIL access is denied
3669 FAIL_DROP access is denied; drop the connection
3670 DEFER can't tell at the moment
3671 ERROR disaster
3672 */
3673
3674 static int
3675 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3676 uschar **user_msgptr, uschar **log_msgptr)
3677 {
3678 int fd = -1;
3679 acl_block *acl = NULL;
3680 uschar *acl_name = US"inline ACL";
3681 uschar *ss;
3682
3683 /* Catch configuration loops */
3684
3685 if (level > 20)
3686 {
3687 *log_msgptr = US"ACL nested too deep: possible loop";
3688 return ERROR;
3689 }
3690
3691 if (s == NULL)
3692 {
3693 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3694 return FAIL;
3695 }
3696
3697 /* At top level, we expand the incoming string. At lower levels, it has already
3698 been expanded as part of condition processing. */
3699
3700 if (level == 0)
3701 {
3702 ss = expand_string(s);
3703 if (ss == NULL)
3704 {
3705 if (expand_string_forcedfail) return OK;
3706 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3707 expand_string_message);
3708 return ERROR;
3709 }
3710 }
3711 else ss = s;
3712
3713 while (isspace(*ss))ss++;
3714
3715 /* If we can't find a named ACL, the default is to parse it as an inline one.
3716 (Unless it begins with a slash; non-existent files give rise to an error.) */
3717
3718 acl_text = ss;
3719
3720 /* Handle the case of a string that does not contain any spaces. Look for a
3721 named ACL among those read from the configuration, or a previously read file.
3722 It is possible that the pointer to the ACL is NULL if the configuration
3723 contains a name with no data. If not found, and the text begins with '/',
3724 read an ACL from a file, and save it so it can be re-used. */
3725
3726 if (Ustrchr(ss, ' ') == NULL)
3727 {
3728 tree_node *t = tree_search(acl_anchor, ss);
3729 if (t != NULL)
3730 {
3731 acl = (acl_block *)(t->data.ptr);
3732 if (acl == NULL)
3733 {
3734 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3735 return FAIL;
3736 }
3737 acl_name = string_sprintf("ACL \"%s\"", ss);
3738 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3739 }
3740
3741 else if (*ss == '/')
3742 {
3743 struct stat statbuf;
3744 fd = Uopen(ss, O_RDONLY, 0);
3745 if (fd < 0)
3746 {
3747 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3748 strerror(errno));
3749 return ERROR;
3750 }
3751
3752 if (fstat(fd, &statbuf) != 0)
3753 {
3754 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3755 strerror(errno));
3756 return ERROR;
3757 }
3758
3759 acl_text = store_get(statbuf.st_size + 1);
3760 acl_text_end = acl_text + statbuf.st_size + 1;
3761
3762 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3763 {
3764 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3765 ss, strerror(errno));
3766 return ERROR;
3767 }
3768 acl_text[statbuf.st_size] = 0;
3769 (void)close(fd);
3770
3771 acl_name = string_sprintf("ACL \"%s\"", ss);
3772 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3773 }
3774 }
3775
3776 /* Parse an ACL that is still in text form. If it came from a file, remember it
3777 in the ACL tree, having read it into the POOL_PERM store pool so that it
3778 persists between multiple messages. */
3779
3780 if (acl == NULL)
3781 {
3782 int old_pool = store_pool;
3783 if (fd >= 0) store_pool = POOL_PERM;
3784 acl = acl_read(acl_getline, log_msgptr);
3785 store_pool = old_pool;
3786 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3787 if (fd >= 0)
3788 {
3789 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3790 Ustrcpy(t->name, ss);
3791 t->data.ptr = acl;
3792 (void)tree_insertnode(&acl_anchor, t);
3793 }
3794 }
3795
3796 /* Now we have an ACL to use. It's possible it may be NULL. */
3797
3798 while (acl != NULL)
3799 {
3800 int cond;
3801 int basic_errno = 0;
3802 BOOL endpass_seen = FALSE;
3803
3804 *log_msgptr = *user_msgptr = NULL;
3805 acl_temp_details = FALSE;
3806
3807 if ((where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT) &&
3808 acl->verb != ACL_ACCEPT &&
3809 acl->verb != ACL_WARN)
3810 {
3811 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT or not-QUIT ACL",
3812 verbs[acl->verb]);
3813 return ERROR;
3814 }
3815
3816 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3817
3818 /* Clear out any search error message from a previous check before testing
3819 this condition. */
3820
3821 search_error_message = NULL;
3822 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3823 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3824
3825 /* Handle special returns: DEFER causes a return except on a WARN verb;
3826 ERROR always causes a return. */
3827
3828 switch (cond)
3829 {
3830 case DEFER:
3831 HDEBUG(D_acl) debug_printf("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
3832 if (basic_errno != ERRNO_CALLOUTDEFER)
3833 {
3834 if (search_error_message != NULL && *search_error_message != 0)
3835 *log_msgptr = search_error_message;
3836 if (smtp_return_error_details) acl_temp_details = TRUE;
3837 }
3838 else
3839 {
3840 acl_temp_details = TRUE;
3841 }
3842 if (acl->verb != ACL_WARN) return DEFER;
3843 break;
3844
3845 default: /* Paranoia */
3846 case ERROR:
3847 HDEBUG(D_acl) debug_printf("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
3848 return ERROR;
3849
3850 case OK:
3851 HDEBUG(D_acl) debug_printf("%s: condition test succeeded in %s\n",
3852 verbs[acl->verb], acl_name);
3853 break;
3854
3855 case FAIL:
3856 HDEBUG(D_acl) debug_printf("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
3857 break;
3858
3859 /* DISCARD and DROP can happen only from a nested ACL condition, and
3860 DISCARD can happen only for an "accept" or "discard" verb. */
3861
3862 case DISCARD:
3863 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\" in %s\n",
3864 verbs[acl->verb], acl_name);
3865 break;
3866
3867 case FAIL_DROP:
3868 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\" in %s\n",
3869 verbs[acl->verb], acl_name);
3870 break;
3871 }
3872
3873 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3874 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3875 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3876
3877 switch(acl->verb)
3878 {
3879 case ACL_ACCEPT:
3880 if (cond == OK || cond == DISCARD) return cond;
3881 if (endpass_seen)
3882 {
3883 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3884 return cond;
3885 }
3886 break;
3887
3888 case ACL_DEFER:
3889 if (cond == OK)
3890 {
3891 acl_temp_details = TRUE;
3892 return DEFER;
3893 }
3894 break;
3895
3896 case ACL_DENY:
3897 if (cond == OK) return FAIL;
3898 break;
3899
3900 case ACL_DISCARD:
3901 if (cond == OK || cond == DISCARD) return DISCARD;
3902 if (endpass_seen)
3903 {
3904 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3905 return cond;
3906 }
3907 break;
3908
3909 case ACL_DROP:
3910 if (cond == OK) return FAIL_DROP;
3911 break;
3912
3913 case ACL_REQUIRE:
3914 if (cond != OK) return cond;
3915 break;
3916
3917 case ACL_WARN:
3918 if (cond == OK)
3919 acl_warn(where, *user_msgptr, *log_msgptr);
3920 else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
3921 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3922 "condition test deferred%s%s", host_and_ident(TRUE),
3923 (*log_msgptr == NULL)? US"" : US": ",
3924 (*log_msgptr == NULL)? US"" : *log_msgptr);
3925 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3926 break;
3927
3928 default:
3929 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3930 acl->verb);
3931 break;
3932 }
3933
3934 /* Pass to the next ACL item */
3935
3936 acl = acl->next;
3937 }
3938
3939 /* We have reached the end of the ACL. This is an implicit DENY. */
3940
3941 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3942 return FAIL;
3943 }
3944
3945
3946
3947
3948 /* Same args as acl_check_internal() above, but the string s is
3949 the name of an ACL followed optionally by up to 9 space-separated arguments.
3950 The name and args are separately expanded. Args go into $acl_arg globals. */
3951 static int
3952 acl_check_wargs(int where, address_item *addr, uschar *s, int level,
3953 uschar **user_msgptr, uschar **log_msgptr)
3954 {
3955 uschar * tmp;
3956 uschar * tmp_arg[9]; /* must match acl_arg[] */
3957 uschar * sav_arg[9]; /* must match acl_arg[] */
3958 int sav_narg;
3959 uschar * name;
3960 int i;
3961 int ret;
3962
3963 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
3964 goto bad;
3965
3966 for (i = 0; i < 9; i++)
3967 {
3968 while (*s && isspace(*s)) s++;
3969 if (!*s) break;
3970 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
3971 {
3972 tmp = name;
3973 goto bad;
3974 }
3975 }
3976
3977 sav_narg = acl_narg;
3978 acl_narg = i;
3979 for (i = 0; i < acl_narg; i++)
3980 {
3981 sav_arg[i] = acl_arg[i];
3982 acl_arg[i] = tmp_arg[i];
3983 }
3984 while (i < 9)
3985 {
3986 sav_arg[i] = acl_arg[i];
3987 acl_arg[i++] = NULL;
3988 }
3989
3990 ret = acl_check_internal(where, addr, name, level, user_msgptr, log_msgptr);
3991
3992 acl_narg = sav_narg;
3993 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
3994 return ret;
3995
3996 bad:
3997 if (expand_string_forcedfail) return ERROR;
3998 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
3999 tmp, expand_string_message);
4000 return search_find_defer?DEFER:ERROR;
4001 }
4002
4003
4004
4005 /*************************************************
4006 * Check access using an ACL *
4007 *************************************************/
4008
4009 /* Alternate interface for ACL, used by expansions */
4010 int
4011 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4012 {
4013 int rc;
4014 address_item adb;
4015 address_item *addr = NULL;
4016
4017 *user_msgptr = *log_msgptr = NULL;
4018 sender_verified_failed = NULL;
4019 ratelimiters_cmd = NULL;
4020 log_reject_target = LOG_MAIN|LOG_REJECT;
4021
4022 if (where == ACL_WHERE_RCPT)
4023 {
4024 adb = address_defaults;
4025 addr = &adb;
4026 addr->address = expand_string(US"$local_part@$domain");
4027 addr->domain = deliver_domain;
4028 addr->local_part = deliver_localpart;
4029 addr->cc_local_part = deliver_localpart;
4030 addr->lc_local_part = deliver_localpart;
4031 }
4032
4033 return acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
4034 }
4035
4036
4037
4038 /* This is the external interface for ACL checks. It sets up an address and the
4039 expansions for $domain and $local_part when called after RCPT, then calls
4040 acl_check_internal() to do the actual work.
4041
4042 Arguments:
4043 where ACL_WHERE_xxxx indicating where called from
4044 recipient RCPT address for RCPT check, else NULL
4045 s the input string; NULL is the same as an empty ACL => DENY
4046 user_msgptr where to put a user error (for SMTP response)
4047 log_msgptr where to put a logging message (not for SMTP response)
4048
4049 Returns: OK access is granted by an ACCEPT verb
4050 DISCARD access is granted by a DISCARD verb
4051 FAIL access is denied
4052 FAIL_DROP access is denied; drop the connection
4053 DEFER can't tell at the moment
4054 ERROR disaster
4055 */
4056 int acl_where = ACL_WHERE_UNKNOWN;
4057
4058 int
4059 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4060 uschar **log_msgptr)
4061 {
4062 int rc;
4063 address_item adb;
4064 address_item *addr = NULL;
4065
4066 *user_msgptr = *log_msgptr = NULL;
4067 sender_verified_failed = NULL;
4068 ratelimiters_cmd = NULL;
4069 log_reject_target = LOG_MAIN|LOG_REJECT;
4070
4071 if (where == ACL_WHERE_RCPT)
4072 {
4073 adb = address_defaults;
4074 addr = &adb;
4075 addr->address = recipient;
4076 if (deliver_split_address(addr) == DEFER)
4077 {
4078 *log_msgptr = US"defer in percent_hack_domains check";
4079 return DEFER;
4080 }
4081 deliver_domain = addr->domain;
4082 deliver_localpart = addr->local_part;
4083 }
4084
4085 acl_where = where;
4086 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
4087 acl_where = ACL_WHERE_UNKNOWN;
4088
4089 /* Cutthrough - if requested,
4090 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4091 and rcpt acl returned accept,
4092 and first recipient (cancel on any subsequents)
4093 open one now and run it up to RCPT acceptance.
4094 A failed verify should cancel cutthrough request.
4095
4096 Initial implementation: dual-write to spool.
4097 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4098
4099 Cease cutthrough copy on rxd final dot; do not send one.
4100
4101 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4102
4103 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4104 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4105 If temp-reject, close the conn (and keep the spooled copy).
4106 If conn-failure, no action (and keep the spooled copy).
4107 */
4108 switch (where)
4109 {
4110 case ACL_WHERE_RCPT:
4111 if( rcpt_count > 1 )
4112 cancel_cutthrough_connection("more than one recipient");
4113 else if (rc == OK && cutthrough_delivery && cutthrough_fd < 0)
4114 open_cutthrough_connection(addr);
4115 break;
4116
4117 case ACL_WHERE_PREDATA:
4118 if( rc == OK )
4119 cutthrough_predata();
4120 else
4121 cancel_cutthrough_connection("predata acl not ok");
4122 break;
4123
4124 case ACL_WHERE_QUIT:
4125 case ACL_WHERE_NOTQUIT:
4126 cancel_cutthrough_connection("quit or notquit");
4127 break;
4128
4129 default:
4130 break;
4131 }
4132
4133 deliver_domain = deliver_localpart = deliver_address_data =
4134 sender_address_data = NULL;
4135
4136 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4137 ACL, which is really in the middle of an SMTP command. */
4138
4139 if (rc == DISCARD)
4140 {
4141 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4142 {
4143 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4144 "ACL", acl_wherenames[where]);
4145 return ERROR;
4146 }
4147 return DISCARD;
4148 }
4149
4150 /* A DROP response is not permitted from MAILAUTH */
4151
4152 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4153 {
4154 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4155 "ACL", acl_wherenames[where]);
4156 return ERROR;
4157 }
4158
4159 /* Before giving a response, take a look at the length of any user message, and
4160 split it up into multiple lines if possible. */
4161
4162 *user_msgptr = string_split_message(*user_msgptr);
4163 if (fake_response != OK)
4164 fake_response_text = string_split_message(fake_response_text);
4165
4166 return rc;
4167 }
4168
4169
4170 /*************************************************
4171 * Create ACL variable *
4172 *************************************************/
4173
4174 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4175 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4176
4177 Argument:
4178 name pointer to the variable's name, starting with c or m
4179
4180 Returns the pointer to variable's tree node
4181 */
4182
4183 tree_node *
4184 acl_var_create(uschar *name)
4185 {
4186 tree_node *node, **root;
4187 root = (name[0] == 'c')? &acl_var_c : &acl_var_m;
4188 node = tree_search(*root, name);
4189 if (node == NULL)
4190 {
4191 node = store_get(sizeof(tree_node) + Ustrlen(name));
4192 Ustrcpy(node->name, name);
4193 (void)tree_insertnode(root, node);
4194 }
4195 node->data.ptr = NULL;
4196 return node;
4197 }
4198
4199
4200
4201 /*************************************************
4202 * Write an ACL variable in spool format *
4203 *************************************************/
4204
4205 /* This function is used as a callback for tree_walk when writing variables to
4206 the spool file. To retain spool file compatibility, what is written is -aclc or
4207 -aclm followed by the rest of the name and the data length, space separated,
4208 then the value itself, starting on a new line, and terminated by an additional
4209 newline. When we had only numbered ACL variables, the first line might look
4210 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4211 acl_cfoo.
4212
4213 Arguments:
4214 name of the variable
4215 value of the variable
4216 ctx FILE pointer (as a void pointer)
4217
4218 Returns: nothing
4219 */
4220
4221 void
4222 acl_var_write(uschar *name, uschar *value, void *ctx)
4223 {
4224 FILE *f = (FILE *)ctx;
4225 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);
4226 }
4227
4228 /* End of acl.c */
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