17f55c2acf0553bfb9012fead09b8e5142bbcbc2
[exim.git] / src / src / acl.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
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",
26 US"defer",
27 US"deny",
28 US"discard",
29 US"drop",
30 US"require",
31 US"warn" };
32
33 /* For each verb, the conditions for which "message" or "log_message" are used
34 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
35 "accept", the FAIL case is used only after "endpass", but that is selected in
36 the code. */
37
38 static int msgcond[] = {
39 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
40 (1<<OK), /* defer */
41 (1<<OK), /* deny */
42 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
43 (1<<OK), /* drop */
44 (1<<FAIL) | (1<<FAIL_DROP), /* require */
45 (1<<OK) /* warn */
46 };
47
48 /* ACL condition and modifier codes - keep in step with the table that
49 follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
50 down. */
51
52 enum { ACLC_ACL,
53 ACLC_ADD_HEADER,
54 ACLC_AUTHENTICATED,
55 #ifdef EXPERIMENTAL_BRIGHTMAIL
56 ACLC_BMI_OPTIN,
57 #endif
58 ACLC_CONDITION,
59 ACLC_CONTINUE,
60 ACLC_CONTROL,
61 #ifdef EXPERIMENTAL_DCC
62 ACLC_DCC,
63 #endif
64 #ifdef WITH_CONTENT_SCAN
65 ACLC_DECODE,
66 #endif
67 ACLC_DELAY,
68 #ifdef WITH_OLD_DEMIME
69 ACLC_DEMIME,
70 #endif
71 #ifndef DISABLE_DKIM
72 ACLC_DKIM_SIGNER,
73 ACLC_DKIM_STATUS,
74 #endif
75 #ifdef EXPERIMENTAL_DMARC
76 ACLC_DMARC_STATUS,
77 #endif
78 ACLC_DNSLISTS,
79 ACLC_DOMAINS,
80 ACLC_ENCRYPTED,
81 ACLC_ENDPASS,
82 ACLC_HOSTS,
83 ACLC_LOCAL_PARTS,
84 ACLC_LOG_MESSAGE,
85 ACLC_LOG_REJECT_TARGET,
86 ACLC_LOGWRITE,
87 #ifdef WITH_CONTENT_SCAN
88 ACLC_MALWARE,
89 #endif
90 ACLC_MESSAGE,
91 #ifdef WITH_CONTENT_SCAN
92 ACLC_MIME_REGEX,
93 #endif
94 ACLC_RATELIMIT,
95 ACLC_RECIPIENTS,
96 #ifdef WITH_CONTENT_SCAN
97 ACLC_REGEX,
98 #endif
99 ACLC_REMOVE_HEADER,
100 ACLC_SENDER_DOMAINS,
101 ACLC_SENDERS,
102 ACLC_SET,
103 #ifdef WITH_CONTENT_SCAN
104 ACLC_SPAM,
105 #endif
106 #ifdef EXPERIMENTAL_SPF
107 ACLC_SPF,
108 ACLC_SPF_GUESS,
109 #endif
110 ACLC_UDPSEND,
111 ACLC_VERIFY };
112
113 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
114 "message", "log_message", "log_reject_target", "logwrite", and "set" are
115 modifiers that look like conditions but always return TRUE. They are used for
116 their side effects. */
117
118 static uschar *conditions[] = {
119 US"acl",
120 US"add_header",
121 US"authenticated",
122 #ifdef EXPERIMENTAL_BRIGHTMAIL
123 US"bmi_optin",
124 #endif
125 US"condition",
126 US"continue",
127 US"control",
128 #ifdef EXPERIMENTAL_DCC
129 US"dcc",
130 #endif
131 #ifdef WITH_CONTENT_SCAN
132 US"decode",
133 #endif
134 US"delay",
135 #ifdef WITH_OLD_DEMIME
136 US"demime",
137 #endif
138 #ifndef DISABLE_DKIM
139 US"dkim_signers",
140 US"dkim_status",
141 #endif
142 #ifdef EXPERIMENTAL_DMARC
143 US"dmarc_status",
144 #endif
145 US"dnslists",
146 US"domains",
147 US"encrypted",
148 US"endpass",
149 US"hosts",
150 US"local_parts",
151 US"log_message",
152 US"log_reject_target",
153 US"logwrite",
154 #ifdef WITH_CONTENT_SCAN
155 US"malware",
156 #endif
157 US"message",
158 #ifdef WITH_CONTENT_SCAN
159 US"mime_regex",
160 #endif
161 US"ratelimit",
162 US"recipients",
163 #ifdef WITH_CONTENT_SCAN
164 US"regex",
165 #endif
166 US"remove_header",
167 US"sender_domains", US"senders", US"set",
168 #ifdef WITH_CONTENT_SCAN
169 US"spam",
170 #endif
171 #ifdef EXPERIMENTAL_SPF
172 US"spf",
173 US"spf_guess",
174 #endif
175 US"udpsend",
176 US"verify" };
177
178
179 /* Return values from decode_control(); keep in step with the table of names
180 that follows! */
181
182 enum {
183 CONTROL_AUTH_UNADVERTISED,
184 #ifdef EXPERIMENTAL_BRIGHTMAIL
185 CONTROL_BMI_RUN,
186 #endif
187 CONTROL_DEBUG,
188 #ifndef DISABLE_DKIM
189 CONTROL_DKIM_VERIFY,
190 #endif
191 #ifdef EXPERIMENTAL_DMARC
192 CONTROL_DMARC_VERIFY,
193 CONTROL_DMARC_FORENSIC,
194 #endif
195 CONTROL_DSCP,
196 CONTROL_ERROR,
197 CONTROL_CASEFUL_LOCAL_PART,
198 CONTROL_CASELOWER_LOCAL_PART,
199 CONTROL_CUTTHROUGH_DELIVERY,
200 CONTROL_ENFORCE_SYNC,
201 CONTROL_NO_ENFORCE_SYNC,
202 CONTROL_FREEZE,
203 CONTROL_QUEUE_ONLY,
204 CONTROL_SUBMISSION,
205 CONTROL_SUPPRESS_LOCAL_FIXUPS,
206 #ifdef WITH_CONTENT_SCAN
207 CONTROL_NO_MBOX_UNSPOOL,
208 #endif
209 CONTROL_FAKEDEFER,
210 CONTROL_FAKEREJECT,
211 #ifdef SUPPORT_I18N
212 CONTROL_UTF8_DOWNCONVERT,
213 #endif
214 CONTROL_NO_MULTILINE,
215 CONTROL_NO_PIPELINING,
216 CONTROL_NO_DELAY_FLUSH,
217 CONTROL_NO_CALLOUT_FLUSH
218 };
219
220 /* ACL control names; keep in step with the table above! This list is used for
221 turning ids into names. The actual list of recognized names is in the variable
222 control_def controls_list[] below. The fact that there are two lists is a mess
223 and should be tidied up. */
224
225 static uschar *controls[] = {
226 US"allow_auth_unadvertised",
227 #ifdef EXPERIMENTAL_BRIGHTMAIL
228 US"bmi_run",
229 #endif
230 US"debug",
231 #ifndef DISABLE_DKIM
232 US"dkim_disable_verify",
233 #endif
234 #ifdef EXPERIMENTAL_DMARC
235 US"dmarc_disable_verify",
236 US"dmarc_enable_forensic",
237 #endif
238 US"dscp",
239 US"error",
240 US"caseful_local_part",
241 US"caselower_local_part",
242 US"cutthrough_delivery",
243 US"enforce_sync",
244 US"no_enforce_sync",
245 US"freeze",
246 US"queue_only",
247 US"submission",
248 US"suppress_local_fixups",
249 #ifdef WITH_CONTENT_SCAN
250 US"no_mbox_unspool",
251 #endif
252 US"fakedefer",
253 US"fakereject",
254 #ifdef SUPPORT_I18N
255 US"utf8_downconvert",
256 #endif
257 US"no_multiline_responses",
258 US"no_pipelining",
259 US"no_delay_flush",
260 US"no_callout_flush"
261 };
262
263 /* Flags to indicate for which conditions/modifiers a string expansion is done
264 at the outer level. In the other cases, expansion already occurs in the
265 checking functions. */
266
267 static uschar cond_expand_at_top[] = {
268 FALSE, /* acl */
269 TRUE, /* add_header */
270 FALSE, /* authenticated */
271 #ifdef EXPERIMENTAL_BRIGHTMAIL
272 TRUE, /* bmi_optin */
273 #endif
274 TRUE, /* condition */
275 TRUE, /* continue */
276 TRUE, /* control */
277 #ifdef EXPERIMENTAL_DCC
278 TRUE, /* dcc */
279 #endif
280 #ifdef WITH_CONTENT_SCAN
281 TRUE, /* decode */
282 #endif
283 TRUE, /* delay */
284 #ifdef WITH_OLD_DEMIME
285 TRUE, /* demime */
286 #endif
287 #ifndef DISABLE_DKIM
288 TRUE, /* dkim_signers */
289 TRUE, /* dkim_status */
290 #endif
291 #ifdef EXPERIMENTAL_DMARC
292 TRUE, /* dmarc_status */
293 #endif
294 TRUE, /* dnslists */
295 FALSE, /* domains */
296 FALSE, /* encrypted */
297 TRUE, /* endpass */
298 FALSE, /* hosts */
299 FALSE, /* local_parts */
300 TRUE, /* log_message */
301 TRUE, /* log_reject_target */
302 TRUE, /* logwrite */
303 #ifdef WITH_CONTENT_SCAN
304 TRUE, /* malware */
305 #endif
306 TRUE, /* message */
307 #ifdef WITH_CONTENT_SCAN
308 TRUE, /* mime_regex */
309 #endif
310 TRUE, /* ratelimit */
311 FALSE, /* recipients */
312 #ifdef WITH_CONTENT_SCAN
313 TRUE, /* regex */
314 #endif
315 TRUE, /* remove_header */
316 FALSE, /* sender_domains */
317 FALSE, /* senders */
318 TRUE, /* set */
319 #ifdef WITH_CONTENT_SCAN
320 TRUE, /* spam */
321 #endif
322 #ifdef EXPERIMENTAL_SPF
323 TRUE, /* spf */
324 TRUE, /* spf_guess */
325 #endif
326 TRUE, /* udpsend */
327 TRUE /* verify */
328 };
329
330 /* Flags to identify the modifiers */
331
332 static uschar cond_modifiers[] = {
333 FALSE, /* acl */
334 TRUE, /* add_header */
335 FALSE, /* authenticated */
336 #ifdef EXPERIMENTAL_BRIGHTMAIL
337 TRUE, /* bmi_optin */
338 #endif
339 FALSE, /* condition */
340 TRUE, /* continue */
341 TRUE, /* control */
342 #ifdef EXPERIMENTAL_DCC
343 FALSE, /* dcc */
344 #endif
345 #ifdef WITH_CONTENT_SCAN
346 FALSE, /* decode */
347 #endif
348 TRUE, /* delay */
349 #ifdef WITH_OLD_DEMIME
350 FALSE, /* demime */
351 #endif
352 #ifndef DISABLE_DKIM
353 FALSE, /* dkim_signers */
354 FALSE, /* dkim_status */
355 #endif
356 #ifdef EXPERIMENTAL_DMARC
357 FALSE, /* dmarc_status */
358 #endif
359 FALSE, /* dnslists */
360 FALSE, /* domains */
361 FALSE, /* encrypted */
362 TRUE, /* endpass */
363 FALSE, /* hosts */
364 FALSE, /* local_parts */
365 TRUE, /* log_message */
366 TRUE, /* log_reject_target */
367 TRUE, /* logwrite */
368 #ifdef WITH_CONTENT_SCAN
369 FALSE, /* malware */
370 #endif
371 TRUE, /* message */
372 #ifdef WITH_CONTENT_SCAN
373 FALSE, /* mime_regex */
374 #endif
375 FALSE, /* ratelimit */
376 FALSE, /* recipients */
377 #ifdef WITH_CONTENT_SCAN
378 FALSE, /* regex */
379 #endif
380 TRUE, /* remove_header */
381 FALSE, /* sender_domains */
382 FALSE, /* senders */
383 TRUE, /* set */
384 #ifdef WITH_CONTENT_SCAN
385 FALSE, /* spam */
386 #endif
387 #ifdef EXPERIMENTAL_SPF
388 FALSE, /* spf */
389 FALSE, /* spf_guess */
390 #endif
391 TRUE, /* udpsend */
392 FALSE /* verify */
393 };
394
395 /* Bit map vector of which conditions and modifiers are not allowed at certain
396 times. For each condition and modifier, there's a bitmap of dis-allowed times.
397 For some, it is easier to specify the negation of a small number of allowed
398 times. */
399
400 static unsigned int cond_forbids[] = {
401 0, /* acl */
402
403 (unsigned int)
404 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
405 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
406 #ifndef DISABLE_PRDR
407 (1<<ACL_WHERE_PRDR)|
408 #endif
409 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
410 (1<<ACL_WHERE_DKIM)|
411 (1<<ACL_WHERE_NOTSMTP_START)),
412
413 (1<<ACL_WHERE_NOTSMTP)| /* authenticated */
414 (1<<ACL_WHERE_NOTSMTP_START)|
415 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
416
417 #ifdef EXPERIMENTAL_BRIGHTMAIL
418 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
419 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
420 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
421 #ifndef DISABLE_PRDR
422 (1<<ACL_WHERE_PRDR)|
423 #endif
424 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
425 (1<<ACL_WHERE_MAILAUTH)|
426 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
427 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
428 (1<<ACL_WHERE_NOTSMTP_START),
429 #endif
430
431 0, /* condition */
432
433 0, /* continue */
434
435 /* Certain types of control are always allowed, so we let it through
436 always and check in the control processing itself. */
437
438 0, /* control */
439
440 #ifdef EXPERIMENTAL_DCC
441 (unsigned int)
442 ~((1<<ACL_WHERE_DATA)| /* dcc */
443 #ifndef DISABLE_PRDR
444 (1<<ACL_WHERE_PRDR)|
445 #endif
446 (1<<ACL_WHERE_NOTSMTP)),
447 #endif
448
449 #ifdef WITH_CONTENT_SCAN
450 (unsigned int)
451 ~(1<<ACL_WHERE_MIME), /* decode */
452 #endif
453
454 (1<<ACL_WHERE_NOTQUIT), /* delay */
455
456 #ifdef WITH_OLD_DEMIME
457 (unsigned int)
458 ~((1<<ACL_WHERE_DATA)| /* demime */
459 #ifndef DISABLE_PRDR
460 (1<<ACL_WHERE_PRDR)|
461 #endif
462 (1<<ACL_WHERE_NOTSMTP)),
463 #endif
464
465 #ifndef DISABLE_DKIM
466 (unsigned int)
467 ~(1<<ACL_WHERE_DKIM), /* dkim_signers */
468
469 (unsigned int)
470 ~(1<<ACL_WHERE_DKIM), /* dkim_status */
471 #endif
472
473 #ifdef EXPERIMENTAL_DMARC
474 (unsigned int)
475 ~(1<<ACL_WHERE_DATA), /* dmarc_status */
476 #endif
477
478 (1<<ACL_WHERE_NOTSMTP)| /* dnslists */
479 (1<<ACL_WHERE_NOTSMTP_START),
480
481 (unsigned int)
482 ~((1<<ACL_WHERE_RCPT) /* domains */
483 #ifndef DISABLE_PRDR
484 |(1<<ACL_WHERE_PRDR)
485 #endif
486 ),
487
488 (1<<ACL_WHERE_NOTSMTP)| /* encrypted */
489 (1<<ACL_WHERE_CONNECT)|
490 (1<<ACL_WHERE_NOTSMTP_START)|
491 (1<<ACL_WHERE_HELO),
492
493 0, /* endpass */
494
495 (1<<ACL_WHERE_NOTSMTP)| /* hosts */
496 (1<<ACL_WHERE_NOTSMTP_START),
497
498 (unsigned int)
499 ~((1<<ACL_WHERE_RCPT) /* local_parts */
500 #ifndef DISABLE_PRDR
501 |(1<<ACL_WHERE_PRDR)
502 #endif
503 ),
504
505 0, /* log_message */
506
507 0, /* log_reject_target */
508
509 0, /* logwrite */
510
511 #ifdef WITH_CONTENT_SCAN
512 (unsigned int)
513 ~((1<<ACL_WHERE_DATA)| /* malware */
514 #ifndef DISABLE_PRDR
515 (1<<ACL_WHERE_PRDR)|
516 #endif
517 (1<<ACL_WHERE_NOTSMTP)),
518 #endif
519
520 0, /* message */
521
522 #ifdef WITH_CONTENT_SCAN
523 (unsigned int)
524 ~(1<<ACL_WHERE_MIME), /* mime_regex */
525 #endif
526
527 0, /* ratelimit */
528
529 (unsigned int)
530 ~(1<<ACL_WHERE_RCPT), /* recipients */
531
532 #ifdef WITH_CONTENT_SCAN
533 (unsigned int)
534 ~((1<<ACL_WHERE_DATA)| /* regex */
535 #ifndef DISABLE_PRDR
536 (1<<ACL_WHERE_PRDR)|
537 #endif
538 (1<<ACL_WHERE_NOTSMTP)|
539 (1<<ACL_WHERE_MIME)),
540 #endif
541
542 (unsigned int)
543 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* remove_header */
544 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
545 #ifndef DISABLE_PRDR
546 (1<<ACL_WHERE_PRDR)|
547 #endif
548 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
549 (1<<ACL_WHERE_NOTSMTP_START)),
550
551 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
552 (1<<ACL_WHERE_HELO)|
553 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
554 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
555 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
556
557 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
558 (1<<ACL_WHERE_HELO)|
559 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
560 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
561 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
562
563 0, /* set */
564
565 #ifdef WITH_CONTENT_SCAN
566 (unsigned int)
567 ~((1<<ACL_WHERE_DATA)| /* spam */
568 #ifndef DISABLE_PRDR
569 (1<<ACL_WHERE_PRDR)|
570 #endif
571 (1<<ACL_WHERE_NOTSMTP)),
572 #endif
573
574 #ifdef EXPERIMENTAL_SPF
575 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
576 (1<<ACL_WHERE_HELO)|
577 (1<<ACL_WHERE_MAILAUTH)|
578 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
579 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
580 (1<<ACL_WHERE_NOTSMTP)|
581 (1<<ACL_WHERE_NOTSMTP_START),
582
583 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf_guess */
584 (1<<ACL_WHERE_HELO)|
585 (1<<ACL_WHERE_MAILAUTH)|
586 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
587 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
588 (1<<ACL_WHERE_NOTSMTP)|
589 (1<<ACL_WHERE_NOTSMTP_START),
590 #endif
591
592 0, /* udpsend */
593
594 /* Certain types of verify are always allowed, so we let it through
595 always and check in the verify function itself */
596
597 0 /* verify */
598 };
599
600
601 /* Bit map vector of which controls are not allowed at certain times. For
602 each control, there's a bitmap of dis-allowed times. For some, it is easier to
603 specify the negation of a small number of allowed times. */
604
605 static unsigned int control_forbids[] = {
606 (unsigned int)
607 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
608
609 #ifdef EXPERIMENTAL_BRIGHTMAIL
610 0, /* bmi_run */
611 #endif
612
613 0, /* debug */
614
615 #ifndef DISABLE_DKIM
616 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_disable_verify */
617 # ifndef DISABLE_PRDR
618 (1<<ACL_WHERE_PRDR)|
619 # endif
620 (1<<ACL_WHERE_NOTSMTP_START),
621 #endif
622
623 #ifdef EXPERIMENTAL_DMARC
624 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dmarc_disable_verify */
625 (1<<ACL_WHERE_NOTSMTP_START),
626 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dmarc_enable_forensic */
627 (1<<ACL_WHERE_NOTSMTP_START),
628 #endif
629
630 (1<<ACL_WHERE_NOTSMTP)|
631 (1<<ACL_WHERE_NOTSMTP_START)|
632 (1<<ACL_WHERE_NOTQUIT), /* dscp */
633
634 0, /* error */
635
636 (unsigned int)
637 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
638
639 (unsigned int)
640 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
641
642 (unsigned int)
643 0, /* cutthrough_delivery */
644
645 (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
646 (1<<ACL_WHERE_NOTSMTP_START),
647
648 (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
649 (1<<ACL_WHERE_NOTSMTP_START),
650
651 (unsigned int)
652 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
653 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
654 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
655 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
656
657 (unsigned int)
658 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
659 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
660 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
661 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
662
663 (unsigned int)
664 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
665 (1<<ACL_WHERE_PREDATA)),
666
667 (unsigned int)
668 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
669 (1<<ACL_WHERE_PREDATA)|
670 (1<<ACL_WHERE_NOTSMTP_START)),
671
672 #ifdef WITH_CONTENT_SCAN
673 (unsigned int)
674 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
675 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
676 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
677 (1<<ACL_WHERE_MIME)),
678 #endif
679
680 (unsigned int)
681 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
682 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
683 #ifndef DISABLE_PRDR
684 (1<<ACL_WHERE_PRDR)|
685 #endif
686 (1<<ACL_WHERE_MIME)),
687
688 (unsigned int)
689 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
690 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
691 #ifndef DISABLE_PRDR
692 (1<<ACL_WHERE_PRDR)|
693 #endif
694 (1<<ACL_WHERE_MIME)),
695
696 #ifdef SUPPORT_I18N
697 0, /* utf8_downconvert */
698 #endif
699
700 (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
701 (1<<ACL_WHERE_NOTSMTP_START),
702
703 (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
704 (1<<ACL_WHERE_NOTSMTP_START),
705
706 (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
707 (1<<ACL_WHERE_NOTSMTP_START),
708
709 (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
710 (1<<ACL_WHERE_NOTSMTP_START)
711 };
712
713 /* Structure listing various control arguments, with their characteristics. */
714
715 typedef struct control_def {
716 uschar *name;
717 int value; /* CONTROL_xxx value */
718 BOOL has_option; /* Has /option(s) following */
719 } control_def;
720
721 static control_def controls_list[] = {
722 { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
723 #ifdef EXPERIMENTAL_BRIGHTMAIL
724 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
725 #endif
726 { US"debug", CONTROL_DEBUG, TRUE },
727 #ifndef DISABLE_DKIM
728 { US"dkim_disable_verify", CONTROL_DKIM_VERIFY, FALSE },
729 #endif
730 #ifdef EXPERIMENTAL_DMARC
731 { US"dmarc_disable_verify", CONTROL_DMARC_VERIFY, FALSE },
732 { US"dmarc_enable_forensic", CONTROL_DMARC_FORENSIC, FALSE },
733 #endif
734 { US"dscp", CONTROL_DSCP, TRUE },
735 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
736 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
737 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
738 { US"freeze", CONTROL_FREEZE, TRUE },
739 { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
740 { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
741 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
742 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
743 { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
744 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
745 #ifdef WITH_CONTENT_SCAN
746 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
747 #endif
748 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
749 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
750 { US"submission", CONTROL_SUBMISSION, TRUE },
751 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE },
752 { US"cutthrough_delivery", CONTROL_CUTTHROUGH_DELIVERY, FALSE },
753 #ifdef SUPPORT_I18N
754 { US"utf8_downconvert", CONTROL_UTF8_DOWNCONVERT, TRUE }
755 #endif
756 };
757
758 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
759 caches its result in a tree to avoid repeated DNS queries. The result is an
760 integer code which is used as an index into the following tables of
761 explanatory strings and verification return codes. */
762
763 static tree_node *csa_cache = NULL;
764
765 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
766 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
767
768 /* The acl_verify_csa() return code is translated into an acl_verify() return
769 code using the following table. It is OK unless the client is definitely not
770 authorized. This is because CSA is supposed to be optional for sending sites,
771 so recipients should not be too strict about checking it - especially because
772 DNS problems are quite likely to occur. It's possible to use $csa_status in
773 further ACL conditions to distinguish ok, unknown, and defer if required, but
774 the aim is to make the usual configuration simple. */
775
776 static int csa_return_code[] = {
777 OK, OK, OK, OK,
778 FAIL, FAIL, FAIL, FAIL
779 };
780
781 static uschar *csa_status_string[] = {
782 US"unknown", US"ok", US"defer", US"defer",
783 US"fail", US"fail", US"fail", US"fail"
784 };
785
786 static uschar *csa_reason_string[] = {
787 US"unknown",
788 US"ok",
789 US"deferred (SRV lookup failed)",
790 US"deferred (target address lookup failed)",
791 US"failed (explicit authorization required)",
792 US"failed (host name not authorized)",
793 US"failed (no authorized addresses)",
794 US"failed (client address mismatch)"
795 };
796
797 /* Options for the ratelimit condition. Note that there are two variants of
798 the per_rcpt option, depending on the ACL that is used to measure the rate.
799 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
800 so the two variants must have the same internal representation as well as
801 the same configuration string. */
802
803 enum {
804 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
805 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
806 };
807
808 #define RATE_SET(var,new) \
809 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
810
811 static uschar *ratelimit_option_string[] = {
812 US"?", US"!", US"per_addr", US"per_byte", US"per_cmd",
813 US"per_conn", US"per_mail", US"per_rcpt", US"per_rcpt"
814 };
815
816 /* Enable recursion between acl_check_internal() and acl_check_condition() */
817
818 static int acl_check_wargs(int, address_item *, const uschar *, int, uschar **,
819 uschar **);
820
821
822 /*************************************************
823 * Pick out name from list *
824 *************************************************/
825
826 /* Use a binary chop method
827
828 Arguments:
829 name name to find
830 list list of names
831 end size of list
832
833 Returns: offset in list, or -1 if not found
834 */
835
836 static int
837 acl_checkname(uschar *name, uschar **list, int end)
838 {
839 int start = 0;
840
841 while (start < end)
842 {
843 int mid = (start + end)/2;
844 int c = Ustrcmp(name, list[mid]);
845 if (c == 0) return mid;
846 if (c < 0) end = mid; else start = mid + 1;
847 }
848
849 return -1;
850 }
851
852
853 /*************************************************
854 * Read and parse one ACL *
855 *************************************************/
856
857 /* This function is called both from readconf in order to parse the ACLs in the
858 configuration file, and also when an ACL is encountered dynamically (e.g. as
859 the result of an expansion). It is given a function to call in order to
860 retrieve the lines of the ACL. This function handles skipping comments and
861 blank lines (where relevant).
862
863 Arguments:
864 func function to get next line of ACL
865 error where to put an error message
866
867 Returns: pointer to ACL, or NULL
868 NULL can be legal (empty ACL); in this case error will be NULL
869 */
870
871 acl_block *
872 acl_read(uschar *(*func)(void), uschar **error)
873 {
874 acl_block *yield = NULL;
875 acl_block **lastp = &yield;
876 acl_block *this = NULL;
877 acl_condition_block *cond;
878 acl_condition_block **condp = NULL;
879 uschar *s;
880
881 *error = NULL;
882
883 while ((s = (*func)()) != NULL)
884 {
885 int v, c;
886 BOOL negated = FALSE;
887 uschar *saveline = s;
888 uschar name[64];
889
890 /* Conditions (but not verbs) are allowed to be negated by an initial
891 exclamation mark. */
892
893 while (isspace(*s)) s++;
894 if (*s == '!')
895 {
896 negated = TRUE;
897 s++;
898 }
899
900 /* Read the name of a verb or a condition, or the start of a new ACL, which
901 can be started by a name, or by a macro definition. */
902
903 s = readconf_readname(name, sizeof(name), s);
904 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
905
906 /* If a verb is unrecognized, it may be another condition or modifier that
907 continues the previous verb. */
908
909 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
910 if (v < 0)
911 {
912 if (this == NULL)
913 {
914 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
915 saveline);
916 return NULL;
917 }
918 }
919
920 /* New verb */
921
922 else
923 {
924 if (negated)
925 {
926 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
927 return NULL;
928 }
929 this = store_get(sizeof(acl_block));
930 *lastp = this;
931 lastp = &(this->next);
932 this->next = NULL;
933 this->verb = v;
934 this->condition = NULL;
935 condp = &(this->condition);
936 if (*s == 0) continue; /* No condition on this line */
937 if (*s == '!')
938 {
939 negated = TRUE;
940 s++;
941 }
942 s = readconf_readname(name, sizeof(name), s); /* Condition name */
943 }
944
945 /* Handle a condition or modifier. */
946
947 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
948 if (c < 0)
949 {
950 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
951 saveline);
952 return NULL;
953 }
954
955 /* The modifiers may not be negated */
956
957 if (negated && cond_modifiers[c])
958 {
959 *error = string_sprintf("ACL error: negation is not allowed with "
960 "\"%s\"", conditions[c]);
961 return NULL;
962 }
963
964 /* ENDPASS may occur only with ACCEPT or DISCARD. */
965
966 if (c == ACLC_ENDPASS &&
967 this->verb != ACL_ACCEPT &&
968 this->verb != ACL_DISCARD)
969 {
970 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
971 conditions[c], verbs[this->verb]);
972 return NULL;
973 }
974
975 cond = store_get(sizeof(acl_condition_block));
976 cond->next = NULL;
977 cond->type = c;
978 cond->u.negated = negated;
979
980 *condp = cond;
981 condp = &(cond->next);
982
983 /* The "set" modifier is different in that its argument is "name=value"
984 rather than just a value, and we can check the validity of the name, which
985 gives us a variable name to insert into the data block. The original ACL
986 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
987 extended to 20 of each type, but after that people successfully argued for
988 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
989 After that, we allow alphanumerics and underscores, but the first character
990 after c or m must be a digit or an underscore. This retains backwards
991 compatibility. */
992
993 if (c == ACLC_SET)
994 {
995 uschar *endptr;
996
997 if (Ustrncmp(s, "acl_c", 5) != 0 &&
998 Ustrncmp(s, "acl_m", 5) != 0)
999 {
1000 *error = string_sprintf("invalid variable name after \"set\" in ACL "
1001 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
1002 return NULL;
1003 }
1004
1005 endptr = s + 5;
1006 if (!isdigit(*endptr) && *endptr != '_')
1007 {
1008 *error = string_sprintf("invalid variable name after \"set\" in ACL "
1009 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
1010 s);
1011 return NULL;
1012 }
1013
1014 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
1015 {
1016 if (!isalnum(*endptr) && *endptr != '_')
1017 {
1018 *error = string_sprintf("invalid character \"%c\" in variable name "
1019 "in ACL modifier \"set %s\"", *endptr, s);
1020 return NULL;
1021 }
1022 endptr++;
1023 }
1024
1025 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
1026 s = endptr;
1027 while (isspace(*s)) s++;
1028 }
1029
1030 /* For "set", we are now positioned for the data. For the others, only
1031 "endpass" has no data */
1032
1033 if (c != ACLC_ENDPASS)
1034 {
1035 if (*s++ != '=')
1036 {
1037 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
1038 cond_modifiers[c]? US"modifier" : US"condition");
1039 return NULL;
1040 }
1041 while (isspace(*s)) s++;
1042 cond->arg = string_copy(s);
1043 }
1044 }
1045
1046 return yield;
1047 }
1048
1049
1050
1051 /*************************************************
1052 * Set up added header line(s) *
1053 *************************************************/
1054
1055 /* This function is called by the add_header modifier, and also from acl_warn()
1056 to implement the now-deprecated way of adding header lines using "message" on a
1057 "warn" verb. The argument is treated as a sequence of header lines which are
1058 added to a chain, provided there isn't an identical one already there.
1059
1060 Argument: string of header lines
1061 Returns: nothing
1062 */
1063
1064 static void
1065 setup_header(const uschar *hstring)
1066 {
1067 const uschar *p, *q;
1068 int hlen = Ustrlen(hstring);
1069
1070 /* Ignore any leading newlines */
1071 while (*hstring == '\n') hstring++, hlen--;
1072
1073 /* An empty string does nothing; ensure exactly one final newline. */
1074 if (hlen <= 0) return;
1075 if (hstring[--hlen] != '\n')
1076 q = string_sprintf("%s\n", hstring);
1077 else if (hstring[hlen-1] == '\n')
1078 {
1079 uschar * s = string_copy(hstring);
1080 while(s[--hlen] == '\n')
1081 s[hlen+1] = '\0';
1082 q = s;
1083 }
1084 else
1085 q = hstring;
1086
1087 /* Loop for multiple header lines, taking care about continuations */
1088
1089 for (p = q; *p != 0; )
1090 {
1091 const uschar *s;
1092 uschar * hdr;
1093 int newtype = htype_add_bot;
1094 header_line **hptr = &acl_added_headers;
1095
1096 /* Find next header line within the string */
1097
1098 for (;;)
1099 {
1100 q = Ustrchr(q, '\n');
1101 if (*(++q) != ' ' && *q != '\t') break;
1102 }
1103
1104 /* If the line starts with a colon, interpret the instruction for where to
1105 add it. This temporarily sets up a new type. */
1106
1107 if (*p == ':')
1108 {
1109 if (strncmpic(p, US":after_received:", 16) == 0)
1110 {
1111 newtype = htype_add_rec;
1112 p += 16;
1113 }
1114 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
1115 {
1116 newtype = htype_add_rfc;
1117 p += 14;
1118 }
1119 else if (strncmpic(p, US":at_start:", 10) == 0)
1120 {
1121 newtype = htype_add_top;
1122 p += 10;
1123 }
1124 else if (strncmpic(p, US":at_end:", 8) == 0)
1125 {
1126 newtype = htype_add_bot;
1127 p += 8;
1128 }
1129 while (*p == ' ' || *p == '\t') p++;
1130 }
1131
1132 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1133 to the front of it. */
1134
1135 for (s = p; s < q - 1; s++)
1136 {
1137 if (*s == ':' || !isgraph(*s)) break;
1138 }
1139
1140 hdr = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
1141 hlen = Ustrlen(hdr);
1142
1143 /* See if this line has already been added */
1144
1145 while (*hptr != NULL)
1146 {
1147 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1148 hptr = &((*hptr)->next);
1149 }
1150
1151 /* Add if not previously present */
1152
1153 if (*hptr == NULL)
1154 {
1155 header_line *h = store_get(sizeof(header_line));
1156 h->text = hdr;
1157 h->next = NULL;
1158 h->type = newtype;
1159 h->slen = hlen;
1160 *hptr = h;
1161 hptr = &(h->next);
1162 }
1163
1164 /* Advance for next header line within the string */
1165
1166 p = q;
1167 }
1168 }
1169
1170
1171
1172 /*************************************************
1173 * List the added header lines *
1174 *************************************************/
1175 uschar *
1176 fn_hdrs_added(void)
1177 {
1178 uschar * ret = NULL;
1179 header_line * h = acl_added_headers;
1180 uschar * s;
1181 uschar * cp;
1182 int size = 0;
1183 int ptr = 0;
1184
1185 if (!h) return NULL;
1186
1187 do
1188 {
1189 s = h->text;
1190 while ((cp = Ustrchr(s, '\n')) != NULL)
1191 {
1192 if (cp[1] == '\0') break;
1193
1194 /* contains embedded newline; needs doubling */
1195 ret = string_cat(ret, &size, &ptr, s, cp-s+1);
1196 ret = string_cat(ret, &size, &ptr, US"\n", 1);
1197 s = cp+1;
1198 }
1199 /* last bit of header */
1200
1201 ret = string_cat(ret, &size, &ptr, s, cp-s+1); /* newline-sep list */
1202 }
1203 while((h = h->next));
1204
1205 ret[ptr-1] = '\0'; /* overwrite last newline */
1206 return ret;
1207 }
1208
1209
1210 /*************************************************
1211 * Set up removed header line(s) *
1212 *************************************************/
1213
1214 /* This function is called by the remove_header modifier. The argument is
1215 treated as a sequence of header names which are added to a colon separated
1216 list, provided there isn't an identical one already there.
1217
1218 Argument: string of header names
1219 Returns: nothing
1220 */
1221
1222 static void
1223 setup_remove_header(const uschar *hnames)
1224 {
1225 if (*hnames != 0)
1226 acl_removed_headers = acl_removed_headers
1227 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1228 : string_copy(hnames);
1229 }
1230
1231
1232
1233 /*************************************************
1234 * Handle warnings *
1235 *************************************************/
1236
1237 /* This function is called when a WARN verb's conditions are true. It adds to
1238 the message's headers, and/or writes information to the log. In each case, this
1239 only happens once (per message for headers, per connection for log).
1240
1241 ** NOTE: The header adding action using the "message" setting is historic, and
1242 its use is now deprecated. The new add_header modifier should be used instead.
1243
1244 Arguments:
1245 where ACL_WHERE_xxxx indicating which ACL this is
1246 user_message message for adding to headers
1247 log_message message for logging, if different
1248
1249 Returns: nothing
1250 */
1251
1252 static void
1253 acl_warn(int where, uschar *user_message, uschar *log_message)
1254 {
1255 if (log_message != NULL && log_message != user_message)
1256 {
1257 uschar *text;
1258 string_item *logged;
1259
1260 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1261 string_printing(log_message));
1262
1263 /* If a sender verification has failed, and the log message is "sender verify
1264 failed", add the failure message. */
1265
1266 if (sender_verified_failed != NULL &&
1267 sender_verified_failed->message != NULL &&
1268 strcmpic(log_message, US"sender verify failed") == 0)
1269 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1270
1271 /* Search previously logged warnings. They are kept in malloc
1272 store so they can be freed at the start of a new message. */
1273
1274 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1275 if (Ustrcmp(logged->text, text) == 0) break;
1276
1277 if (logged == NULL)
1278 {
1279 int length = Ustrlen(text) + 1;
1280 log_write(0, LOG_MAIN, "%s", text);
1281 logged = store_malloc(sizeof(string_item) + length);
1282 logged->text = (uschar *)logged + sizeof(string_item);
1283 memcpy(logged->text, text, length);
1284 logged->next = acl_warn_logged;
1285 acl_warn_logged = logged;
1286 }
1287 }
1288
1289 /* If there's no user message, we are done. */
1290
1291 if (user_message == NULL) return;
1292
1293 /* If this isn't a message ACL, we can't do anything with a user message.
1294 Log an error. */
1295
1296 if (where > ACL_WHERE_NOTSMTP)
1297 {
1298 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1299 "found in a non-message (%s) ACL: cannot specify header lines here: "
1300 "message ignored", acl_wherenames[where]);
1301 return;
1302 }
1303
1304 /* The code for setting up header lines is now abstracted into a separate
1305 function so that it can be used for the add_header modifier as well. */
1306
1307 setup_header(user_message);
1308 }
1309
1310
1311
1312 /*************************************************
1313 * Verify and check reverse DNS *
1314 *************************************************/
1315
1316 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1317 address if this has not yet been done. The host_name_lookup() function checks
1318 that one of these names resolves to an address list that contains the client IP
1319 address, so we don't actually have to do the check here.
1320
1321 Arguments:
1322 user_msgptr pointer for user message
1323 log_msgptr pointer for log message
1324
1325 Returns: OK verification condition succeeded
1326 FAIL verification failed
1327 DEFER there was a problem verifying
1328 */
1329
1330 static int
1331 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1332 {
1333 int rc;
1334
1335 user_msgptr = user_msgptr; /* stop compiler warning */
1336
1337 /* Previous success */
1338
1339 if (sender_host_name != NULL) return OK;
1340
1341 /* Previous failure */
1342
1343 if (host_lookup_failed)
1344 {
1345 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1346 return FAIL;
1347 }
1348
1349 /* Need to do a lookup */
1350
1351 HDEBUG(D_acl)
1352 debug_printf("looking up host name to force name/address consistency check\n");
1353
1354 if ((rc = host_name_lookup()) != OK)
1355 {
1356 *log_msgptr = (rc == DEFER)?
1357 US"host lookup deferred for reverse lookup check"
1358 :
1359 string_sprintf("host lookup failed for reverse lookup check%s",
1360 host_lookup_msg);
1361 return rc; /* DEFER or FAIL */
1362 }
1363
1364 host_build_sender_fullhost();
1365 return OK;
1366 }
1367
1368
1369
1370 /*************************************************
1371 * Check client IP address matches CSA target *
1372 *************************************************/
1373
1374 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1375 response for address records belonging to the CSA target hostname. The section
1376 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1377 If one of the addresses matches the client's IP address, then the client is
1378 authorized by CSA. If there are target IP addresses but none of them match
1379 then the client is using an unauthorized IP address. If there are no target IP
1380 addresses then the client cannot be using an authorized IP address. (This is
1381 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1382
1383 Arguments:
1384 dnsa the DNS answer block
1385 dnss a DNS scan block for us to use
1386 reset option specifing what portion to scan, as described above
1387 target the target hostname to use for matching RR names
1388
1389 Returns: CSA_OK successfully authorized
1390 CSA_FAIL_MISMATCH addresses found but none matched
1391 CSA_FAIL_NOADDR no target addresses found
1392 */
1393
1394 static int
1395 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1396 uschar *target)
1397 {
1398 dns_record *rr;
1399 dns_address *da;
1400
1401 BOOL target_found = FALSE;
1402
1403 for (rr = dns_next_rr(dnsa, dnss, reset);
1404 rr != NULL;
1405 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1406 {
1407 /* Check this is an address RR for the target hostname. */
1408
1409 if (rr->type != T_A
1410 #if HAVE_IPV6
1411 && rr->type != T_AAAA
1412 #endif
1413 ) continue;
1414
1415 if (strcmpic(target, rr->name) != 0) continue;
1416
1417 target_found = TRUE;
1418
1419 /* Turn the target address RR into a list of textual IP addresses and scan
1420 the list. There may be more than one if it is an A6 RR. */
1421
1422 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1423 {
1424 /* If the client IP address matches the target IP address, it's good! */
1425
1426 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1427
1428 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1429 }
1430 }
1431
1432 /* If we found some target addresses but none of them matched, the client is
1433 using an unauthorized IP address, otherwise the target has no authorized IP
1434 addresses. */
1435
1436 if (target_found) return CSA_FAIL_MISMATCH;
1437 else return CSA_FAIL_NOADDR;
1438 }
1439
1440
1441
1442 /*************************************************
1443 * Verify Client SMTP Authorization *
1444 *************************************************/
1445
1446 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1447 to find the CSA SRV record corresponding to the domain argument, or
1448 $sender_helo_name if no argument is provided. It then checks that the
1449 client is authorized, and that its IP address corresponds to the SRV
1450 target's address by calling acl_verify_csa_address() above. The address
1451 should have been returned in the DNS response's ADDITIONAL section, but if
1452 not we perform another DNS lookup to get it.
1453
1454 Arguments:
1455 domain pointer to optional parameter following verify = csa
1456
1457 Returns: CSA_UNKNOWN no valid CSA record found
1458 CSA_OK successfully authorized
1459 CSA_FAIL_* client is definitely not authorized
1460 CSA_DEFER_* there was a DNS problem
1461 */
1462
1463 static int
1464 acl_verify_csa(const uschar *domain)
1465 {
1466 tree_node *t;
1467 const uschar *found;
1468 uschar *p;
1469 int priority, weight, port;
1470 dns_answer dnsa;
1471 dns_scan dnss;
1472 dns_record *rr;
1473 int rc, type;
1474 uschar target[256];
1475
1476 /* Work out the domain we are using for the CSA lookup. The default is the
1477 client's HELO domain. If the client has not said HELO, use its IP address
1478 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1479
1480 while (isspace(*domain) && *domain != '\0') ++domain;
1481 if (*domain == '\0') domain = sender_helo_name;
1482 if (domain == NULL) domain = sender_host_address;
1483 if (sender_host_address == NULL) return CSA_UNKNOWN;
1484
1485 /* If we have an address literal, strip off the framing ready for turning it
1486 into a domain. The framing consists of matched square brackets possibly
1487 containing a keyword and a colon before the actual IP address. */
1488
1489 if (domain[0] == '[')
1490 {
1491 const uschar *start = Ustrchr(domain, ':');
1492 if (start == NULL) start = domain;
1493 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1494 }
1495
1496 /* Turn domains that look like bare IP addresses into domains in the reverse
1497 DNS. This code also deals with address literals and $sender_host_address. It's
1498 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1499 address literals, but it's probably the most friendly thing to do. This is an
1500 extension to CSA, so we allow it to be turned off for proper conformance. */
1501
1502 if (string_is_ip_address(domain, NULL) != 0)
1503 {
1504 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1505 dns_build_reverse(domain, target);
1506 domain = target;
1507 }
1508
1509 /* Find out if we've already done the CSA check for this domain. If we have,
1510 return the same result again. Otherwise build a new cached result structure
1511 for this domain. The name is filled in now, and the value is filled in when
1512 we return from this function. */
1513
1514 t = tree_search(csa_cache, domain);
1515 if (t != NULL) return t->data.val;
1516
1517 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1518 Ustrcpy(t->name, domain);
1519 (void)tree_insertnode(&csa_cache, t);
1520
1521 /* Now we are ready to do the actual DNS lookup(s). */
1522
1523 found = domain;
1524 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1525 {
1526 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1527
1528 default:
1529 return t->data.val = CSA_DEFER_SRV;
1530
1531 /* If we found nothing, the client's authorization is unknown. */
1532
1533 case DNS_NOMATCH:
1534 case DNS_NODATA:
1535 return t->data.val = CSA_UNKNOWN;
1536
1537 /* We got something! Go on to look at the reply in more detail. */
1538
1539 case DNS_SUCCEED:
1540 break;
1541 }
1542
1543 /* Scan the reply for well-formed CSA SRV records. */
1544
1545 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1546 rr != NULL;
1547 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1548 {
1549 if (rr->type != T_SRV) continue;
1550
1551 /* Extract the numerical SRV fields (p is incremented) */
1552
1553 p = rr->data;
1554 GETSHORT(priority, p);
1555 GETSHORT(weight, p);
1556 GETSHORT(port, p);
1557
1558 DEBUG(D_acl)
1559 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1560
1561 /* Check the CSA version number */
1562
1563 if (priority != 1) continue;
1564
1565 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1566 found by dns_special_lookup() is a parent of the one we asked for), we check
1567 the subdomain assertions in the port field. At the moment there's only one
1568 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1569 SRV records of their own. */
1570
1571 if (Ustrcmp(found, domain) != 0)
1572 {
1573 if (port & 1)
1574 return t->data.val = CSA_FAIL_EXPLICIT;
1575 else
1576 return t->data.val = CSA_UNKNOWN;
1577 }
1578
1579 /* This CSA SRV record refers directly to our domain, so we check the value
1580 in the weight field to work out the domain's authorization. 0 and 1 are
1581 unauthorized; 3 means the client is authorized but we can't check the IP
1582 address in order to authenticate it, so we treat it as unknown; values
1583 greater than 3 are undefined. */
1584
1585 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1586
1587 if (weight > 2) continue;
1588
1589 /* Weight == 2, which means the domain is authorized. We must check that the
1590 client's IP address is listed as one of the SRV target addresses. Save the
1591 target hostname then break to scan the additional data for its addresses. */
1592
1593 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1594 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1595
1596 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1597
1598 break;
1599 }
1600
1601 /* If we didn't break the loop then no appropriate records were found. */
1602
1603 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1604
1605 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1606 A target of "." indicates there are no valid addresses, so the client cannot
1607 be authorized. (This is an odd configuration because weight=2 target=. is
1608 equivalent to weight=1, but we check for it in order to keep load off the
1609 root name servers.) Note that dn_expand() turns "." into "". */
1610
1611 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1612
1613 /* Scan the additional section of the CSA SRV reply for addresses belonging
1614 to the target. If the name server didn't return any additional data (e.g.
1615 because it does not fully support SRV records), we need to do another lookup
1616 to obtain the target addresses; otherwise we have a definitive result. */
1617
1618 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1619 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1620
1621 /* The DNS lookup type corresponds to the IP version used by the client. */
1622
1623 #if HAVE_IPV6
1624 if (Ustrchr(sender_host_address, ':') != NULL)
1625 type = T_AAAA;
1626 else
1627 #endif /* HAVE_IPV6 */
1628 type = T_A;
1629
1630
1631 lookup_dnssec_authenticated = NULL;
1632 switch (dns_lookup(&dnsa, target, type, NULL))
1633 {
1634 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1635
1636 default:
1637 return t->data.val = CSA_DEFER_ADDR;
1638
1639 /* If the query succeeded, scan the addresses and return the result. */
1640
1641 case DNS_SUCCEED:
1642 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1643 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1644 /* else fall through */
1645
1646 /* If the target has no IP addresses, the client cannot have an authorized
1647 IP address. However, if the target site uses A6 records (not AAAA records)
1648 we have to do yet another lookup in order to check them. */
1649
1650 case DNS_NOMATCH:
1651 case DNS_NODATA:
1652 return t->data.val = CSA_FAIL_NOADDR;
1653 }
1654 }
1655
1656
1657
1658 /*************************************************
1659 * Handle verification (address & other) *
1660 *************************************************/
1661
1662 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1663 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1664 VERIFY_HDR_NAMES_ASCII
1665 };
1666 typedef struct {
1667 uschar * name;
1668 int value;
1669 unsigned where_allowed; /* bitmap */
1670 BOOL no_options; /* Never has /option(s) following */
1671 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1672 } verify_type_t;
1673 static verify_type_t verify_type_list[] = {
1674 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, FALSE, 0 },
1675 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1676 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1677 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1678 { US"header_syntax", VERIFY_HDR_SYNTAX, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1679 { US"not_blind", VERIFY_NOT_BLIND, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1680 { US"header_sender", VERIFY_HDR_SNDR, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), FALSE, 0 },
1681 { US"sender", VERIFY_SNDR, (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)
1682 |(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP),
1683 FALSE, 6 },
1684 { US"recipient", VERIFY_RCPT, (1<<ACL_WHERE_RCPT), FALSE, 0 },
1685 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 }
1686 };
1687
1688
1689 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1690 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1691 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1692 CALLOUT_TIME
1693 };
1694 typedef struct {
1695 uschar * name;
1696 int value;
1697 int flag;
1698 BOOL has_option; /* Has =option(s) following */
1699 BOOL timeval; /* Has a time value */
1700 } callout_opt_t;
1701 static callout_opt_t callout_opt_list[] = {
1702 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1703 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1704 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1705 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1706 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1707 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1708 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1709 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1710 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1711 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1712 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1713 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1714 };
1715
1716
1717
1718 /* This function implements the "verify" condition. It is called when
1719 encountered in any ACL, because some tests are almost always permitted. Some
1720 just don't make sense, and always fail (for example, an attempt to test a host
1721 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1722
1723 Arguments:
1724 where where called from
1725 addr the recipient address that the ACL is handling, or NULL
1726 arg the argument of "verify"
1727 user_msgptr pointer for user message
1728 log_msgptr pointer for log message
1729 basic_errno where to put verify errno
1730
1731 Returns: OK verification condition succeeded
1732 FAIL verification failed
1733 DEFER there was a problem verifying
1734 ERROR syntax error
1735 */
1736
1737 static int
1738 acl_verify(int where, address_item *addr, const uschar *arg,
1739 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1740 {
1741 int sep = '/';
1742 int callout = -1;
1743 int callout_overall = -1;
1744 int callout_connect = -1;
1745 int verify_options = 0;
1746 int rc;
1747 BOOL verify_header_sender = FALSE;
1748 BOOL defer_ok = FALSE;
1749 BOOL callout_defer_ok = FALSE;
1750 BOOL no_details = FALSE;
1751 BOOL success_on_redirect = FALSE;
1752 address_item *sender_vaddr = NULL;
1753 uschar *verify_sender_address = NULL;
1754 uschar *pm_mailfrom = NULL;
1755 uschar *se_mailfrom = NULL;
1756
1757 /* Some of the verify items have slash-separated options; some do not. Diagnose
1758 an error if options are given for items that don't expect them.
1759 */
1760
1761 uschar *slash = Ustrchr(arg, '/');
1762 const uschar *list = arg;
1763 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1764 verify_type_t * vp;
1765
1766 if (ss == NULL) goto BAD_VERIFY;
1767
1768 /* Handle name/address consistency verification in a separate function. */
1769
1770 for (vp= verify_type_list;
1771 (char *)vp < (char *)verify_type_list + sizeof(verify_type_list);
1772 vp++
1773 )
1774 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1775 : strcmpic (ss, vp->name) == 0)
1776 break;
1777 if ((char *)vp >= (char *)verify_type_list + sizeof(verify_type_list))
1778 goto BAD_VERIFY;
1779
1780 if (vp->no_options && slash != NULL)
1781 {
1782 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1783 "(this verify item has no options)", arg);
1784 return ERROR;
1785 }
1786 if (!(vp->where_allowed & (1<<where)))
1787 {
1788 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", vp->name, acl_wherenames[where]);
1789 return ERROR;
1790 }
1791 switch(vp->value)
1792 {
1793 case VERIFY_REV_HOST_LKUP:
1794 if (sender_host_address == NULL) return OK;
1795 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1796 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1797 if (strcmpic(ss, US"defer_ok") == 0)
1798 return OK;
1799 return rc;
1800
1801 case VERIFY_CERT:
1802 /* TLS certificate verification is done at STARTTLS time; here we just
1803 test whether it was successful or not. (This is for optional verification; for
1804 mandatory verification, the connection doesn't last this long.) */
1805
1806 if (tls_in.certificate_verified) return OK;
1807 *user_msgptr = US"no verified certificate";
1808 return FAIL;
1809
1810 case VERIFY_HELO:
1811 /* We can test the result of optional HELO verification that might have
1812 occurred earlier. If not, we can attempt the verification now. */
1813
1814 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1815 return helo_verified? OK : FAIL;
1816
1817 case VERIFY_CSA:
1818 /* Do Client SMTP Authorization checks in a separate function, and turn the
1819 result code into user-friendly strings. */
1820
1821 rc = acl_verify_csa(list);
1822 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1823 csa_reason_string[rc]);
1824 csa_status = csa_status_string[rc];
1825 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1826 return csa_return_code[rc];
1827
1828 case VERIFY_HDR_SYNTAX:
1829 /* Check that all relevant header lines have the correct syntax. If there is
1830 a syntax error, we return details of the error to the sender if configured to
1831 send out full details. (But a "message" setting on the ACL can override, as
1832 always). */
1833
1834 rc = verify_check_headers(log_msgptr);
1835 if (rc != OK && *log_msgptr)
1836 if (smtp_return_error_details)
1837 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1838 else
1839 acl_verify_message = *log_msgptr;
1840 return rc;
1841
1842 case VERIFY_HDR_NAMES_ASCII:
1843 /* Check that all header names are true 7 bit strings
1844 See RFC 5322, 2.2. and RFC 6532, 3. */
1845
1846 rc = verify_check_header_names_ascii(log_msgptr);
1847 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1848 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1849 return rc;
1850
1851 case VERIFY_NOT_BLIND:
1852 /* Check that no recipient of this message is "blind", that is, every envelope
1853 recipient must be mentioned in either To: or Cc:. */
1854
1855 rc = verify_check_notblind();
1856 if (rc != OK)
1857 {
1858 *log_msgptr = string_sprintf("bcc recipient detected");
1859 if (smtp_return_error_details)
1860 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1861 }
1862 return rc;
1863
1864 /* The remaining verification tests check recipient and sender addresses,
1865 either from the envelope or from the header. There are a number of
1866 slash-separated options that are common to all of them. */
1867
1868 case VERIFY_HDR_SNDR:
1869 verify_header_sender = TRUE;
1870 break;
1871
1872 case VERIFY_SNDR:
1873 /* In the case of a sender, this can optionally be followed by an address to use
1874 in place of the actual sender (rare special-case requirement). */
1875 {
1876 uschar *s = ss + 6;
1877 if (*s == 0)
1878 verify_sender_address = sender_address;
1879 else
1880 {
1881 while (isspace(*s)) s++;
1882 if (*s++ != '=') goto BAD_VERIFY;
1883 while (isspace(*s)) s++;
1884 verify_sender_address = string_copy(s);
1885 }
1886 }
1887 break;
1888
1889 case VERIFY_RCPT:
1890 break;
1891 }
1892
1893
1894
1895 /* Remaining items are optional; they apply to sender and recipient
1896 verification, including "header sender" verification. */
1897
1898 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1899 != NULL)
1900 {
1901 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1902 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1903 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1904
1905 /* These two old options are left for backwards compatibility */
1906
1907 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1908 {
1909 callout_defer_ok = TRUE;
1910 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1911 }
1912
1913 else if (strcmpic(ss, US"check_postmaster") == 0)
1914 {
1915 pm_mailfrom = US"";
1916 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1917 }
1918
1919 /* The callout option has a number of sub-options, comma separated */
1920
1921 else if (strncmpic(ss, US"callout", 7) == 0)
1922 {
1923 callout = CALLOUT_TIMEOUT_DEFAULT;
1924 ss += 7;
1925 if (*ss != 0)
1926 {
1927 while (isspace(*ss)) ss++;
1928 if (*ss++ == '=')
1929 {
1930 const uschar * sublist = ss;
1931 int optsep = ',';
1932 uschar *opt;
1933 uschar buffer[256];
1934 while (isspace(*sublist)) sublist++;
1935
1936 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer)))
1937 != NULL)
1938 {
1939 callout_opt_t * op;
1940 double period = 1.0F;
1941
1942 for (op= callout_opt_list; op->name; op++)
1943 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1944 break;
1945
1946 verify_options |= op->flag;
1947 if (op->has_option)
1948 {
1949 opt += Ustrlen(op->name);
1950 while (isspace(*opt)) opt++;
1951 if (*opt++ != '=')
1952 {
1953 *log_msgptr = string_sprintf("'=' expected after "
1954 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1955 return ERROR;
1956 }
1957 while (isspace(*opt)) opt++;
1958 }
1959 if (op->timeval)
1960 {
1961 period = readconf_readtime(opt, 0, FALSE);
1962 if (period < 0)
1963 {
1964 *log_msgptr = string_sprintf("bad time value in ACL condition "
1965 "\"verify %s\"", arg);
1966 return ERROR;
1967 }
1968 }
1969
1970 switch(op->value)
1971 {
1972 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1973 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1974 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1975 case CALLOUT_MAILFROM:
1976 if (!verify_header_sender)
1977 {
1978 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1979 "callout option only for verify=header_sender (detected in ACL "
1980 "condition \"%s\")", arg);
1981 return ERROR;
1982 }
1983 se_mailfrom = string_copy(opt);
1984 break;
1985 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1986 case CALLOUT_MAXWAIT: callout_overall = period; break;
1987 case CALLOUT_CONNECT: callout_connect = period; break;
1988 case CALLOUT_TIME: callout = period; break;
1989 }
1990 }
1991 }
1992 else
1993 {
1994 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1995 "ACL condition \"%s\"", arg);
1996 return ERROR;
1997 }
1998 }
1999 }
2000
2001 /* Option not recognized */
2002
2003 else
2004 {
2005 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
2006 "condition \"verify %s\"", ss, arg);
2007 return ERROR;
2008 }
2009 }
2010
2011 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
2012 (vopt_callout_recipsender|vopt_callout_recippmaster))
2013 {
2014 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
2015 "for a recipient callout";
2016 return ERROR;
2017 }
2018
2019 /* Handle sender-in-header verification. Default the user message to the log
2020 message if giving out verification details. */
2021
2022 if (verify_header_sender)
2023 {
2024 int verrno;
2025 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
2026 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
2027 &verrno);
2028 if (rc != OK)
2029 {
2030 *basic_errno = verrno;
2031 if (smtp_return_error_details)
2032 {
2033 if (*user_msgptr == NULL && *log_msgptr != NULL)
2034 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
2035 if (rc == DEFER) acl_temp_details = TRUE;
2036 }
2037 }
2038 }
2039
2040 /* Handle a sender address. The default is to verify *the* sender address, but
2041 optionally a different address can be given, for special requirements. If the
2042 address is empty, we are dealing with a bounce message that has no sender, so
2043 we cannot do any checking. If the real sender address gets rewritten during
2044 verification (e.g. DNS widening), set the flag to stop it being rewritten again
2045 during message reception.
2046
2047 A list of verified "sender" addresses is kept to try to avoid doing to much
2048 work repetitively when there are multiple recipients in a message and they all
2049 require sender verification. However, when callouts are involved, it gets too
2050 complicated because different recipients may require different callout options.
2051 Therefore, we always do a full sender verify when any kind of callout is
2052 specified. Caching elsewhere, for instance in the DNS resolver and in the
2053 callout handling, should ensure that this is not terribly inefficient. */
2054
2055 else if (verify_sender_address != NULL)
2056 {
2057 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
2058 != 0)
2059 {
2060 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
2061 "sender verify callout";
2062 return ERROR;
2063 }
2064
2065 sender_vaddr = verify_checked_sender(verify_sender_address);
2066 if (sender_vaddr != NULL && /* Previously checked */
2067 callout <= 0) /* No callout needed this time */
2068 {
2069 /* If the "routed" flag is set, it means that routing worked before, so
2070 this check can give OK (the saved return code value, if set, belongs to a
2071 callout that was done previously). If the "routed" flag is not set, routing
2072 must have failed, so we use the saved return code. */
2073
2074 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
2075 {
2076 rc = sender_vaddr->special_action;
2077 *basic_errno = sender_vaddr->basic_errno;
2078 }
2079 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
2080 }
2081
2082 /* Do a new verification, and cache the result. The cache is used to avoid
2083 verifying the sender multiple times for multiple RCPTs when callouts are not
2084 specified (see comments above).
2085
2086 The cache is also used on failure to give details in response to the first
2087 RCPT that gets bounced for this reason. However, this can be suppressed by
2088 the no_details option, which sets the flag that says "this detail has already
2089 been sent". The cache normally contains just one address, but there may be
2090 more in esoteric circumstances. */
2091
2092 else
2093 {
2094 BOOL routed = TRUE;
2095 uschar *save_address_data = deliver_address_data;
2096
2097 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
2098 #ifdef SUPPORT_I18N
2099 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
2100 {
2101 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
2102 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
2103 }
2104 #endif
2105 if (no_details) setflag(sender_vaddr, af_sverify_told);
2106 if (verify_sender_address[0] != 0)
2107 {
2108 /* If this is the real sender address, save the unrewritten version
2109 for use later in receive. Otherwise, set a flag so that rewriting the
2110 sender in verify_address() does not update sender_address. */
2111
2112 if (verify_sender_address == sender_address)
2113 sender_address_unrewritten = sender_address;
2114 else
2115 verify_options |= vopt_fake_sender;
2116
2117 if (success_on_redirect)
2118 verify_options |= vopt_success_on_redirect;
2119
2120 /* The recipient, qualify, and expn options are never set in
2121 verify_options. */
2122
2123 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2124 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2125
2126 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
2127
2128 if (rc == OK)
2129 {
2130 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2131 {
2132 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
2133 verify_sender_address, sender_vaddr->address);
2134 }
2135 else
2136 {
2137 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
2138 verify_sender_address);
2139 }
2140 }
2141 else *basic_errno = sender_vaddr->basic_errno;
2142 }
2143 else rc = OK; /* Null sender */
2144
2145 /* Cache the result code */
2146
2147 if (routed) setflag(sender_vaddr, af_verify_routed);
2148 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2149 sender_vaddr->special_action = rc;
2150 sender_vaddr->next = sender_verified_list;
2151 sender_verified_list = sender_vaddr;
2152
2153 /* Restore the recipient address data, which might have been clobbered by
2154 the sender verification. */
2155
2156 deliver_address_data = save_address_data;
2157 }
2158
2159 /* Put the sender address_data value into $sender_address_data */
2160
2161 sender_address_data = sender_vaddr->prop.address_data;
2162 }
2163
2164 /* A recipient address just gets a straightforward verify; again we must handle
2165 the DEFER overrides. */
2166
2167 else
2168 {
2169 address_item addr2;
2170
2171 if (success_on_redirect)
2172 verify_options |= vopt_success_on_redirect;
2173
2174 /* We must use a copy of the address for verification, because it might
2175 get rewritten. */
2176
2177 addr2 = *addr;
2178 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2179 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2180 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
2181
2182 *basic_errno = addr2.basic_errno;
2183 *log_msgptr = addr2.message;
2184 *user_msgptr = (addr2.user_message != NULL)?
2185 addr2.user_message : addr2.message;
2186
2187 /* Allow details for temporary error if the address is so flagged. */
2188 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
2189
2190 /* Make $address_data visible */
2191 deliver_address_data = addr2.prop.address_data;
2192 }
2193
2194 /* We have a result from the relevant test. Handle defer overrides first. */
2195
2196 if (rc == DEFER && (defer_ok ||
2197 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2198 {
2199 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
2200 defer_ok? "defer_ok" : "callout_defer_ok");
2201 rc = OK;
2202 }
2203
2204 /* If we've failed a sender, set up a recipient message, and point
2205 sender_verified_failed to the address item that actually failed. */
2206
2207 if (rc != OK && verify_sender_address != NULL)
2208 {
2209 if (rc != DEFER)
2210 *log_msgptr = *user_msgptr = US"Sender verify failed";
2211 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2212 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2213 else
2214 {
2215 *log_msgptr = US"Could not complete sender verify callout";
2216 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2217 *log_msgptr;
2218 }
2219
2220 sender_verified_failed = sender_vaddr;
2221 }
2222
2223 /* Verifying an address messes up the values of $domain and $local_part,
2224 so reset them before returning if this is a RCPT ACL. */
2225
2226 if (addr != NULL)
2227 {
2228 deliver_domain = addr->domain;
2229 deliver_localpart = addr->local_part;
2230 }
2231 return rc;
2232
2233 /* Syntax errors in the verify argument come here. */
2234
2235 BAD_VERIFY:
2236 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2237 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2238 "or \"reverse_host_lookup\" at start of ACL condition "
2239 "\"verify %s\"", arg);
2240 return ERROR;
2241 }
2242
2243
2244
2245
2246 /*************************************************
2247 * Check argument for control= modifier *
2248 *************************************************/
2249
2250 /* Called from acl_check_condition() below
2251
2252 Arguments:
2253 arg the argument string for control=
2254 pptr set to point to the terminating character
2255 where which ACL we are in
2256 log_msgptr for error messages
2257
2258 Returns: CONTROL_xxx value
2259 */
2260
2261 static int
2262 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2263 {
2264 int len;
2265 control_def *d;
2266
2267 for (d = controls_list;
2268 d < controls_list + sizeof(controls_list)/sizeof(control_def);
2269 d++)
2270 {
2271 len = Ustrlen(d->name);
2272 if (Ustrncmp(d->name, arg, len) == 0) break;
2273 }
2274
2275 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
2276 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
2277 {
2278 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2279 return CONTROL_ERROR;
2280 }
2281
2282 *pptr = arg + len;
2283 return d->value;
2284 }
2285
2286
2287
2288
2289 /*************************************************
2290 * Return a ratelimit error *
2291 *************************************************/
2292
2293 /* Called from acl_ratelimit() below
2294
2295 Arguments:
2296 log_msgptr for error messages
2297 format format string
2298 ... supplementary arguments
2299 ss ratelimit option name
2300 where ACL_WHERE_xxxx indicating which ACL this is
2301
2302 Returns: ERROR
2303 */
2304
2305 static int
2306 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2307 {
2308 va_list ap;
2309 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2310 va_start(ap, format);
2311 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2312 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2313 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2314 va_end(ap);
2315 *log_msgptr = string_sprintf(
2316 "error in arguments to \"ratelimit\" condition: %s", buffer);
2317 return ERROR;
2318 }
2319
2320
2321
2322
2323 /*************************************************
2324 * Handle rate limiting *
2325 *************************************************/
2326
2327 /* Called by acl_check_condition() below to calculate the result
2328 of the ACL ratelimit condition.
2329
2330 Note that the return value might be slightly unexpected: if the
2331 sender's rate is above the limit then the result is OK. This is
2332 similar to the dnslists condition, and is so that you can write
2333 ACL clauses like: defer ratelimit = 15 / 1h
2334
2335 Arguments:
2336 arg the option string for ratelimit=
2337 where ACL_WHERE_xxxx indicating which ACL this is
2338 log_msgptr for error messages
2339
2340 Returns: OK - Sender's rate is above limit
2341 FAIL - Sender's rate is below limit
2342 DEFER - Problem opening ratelimit database
2343 ERROR - Syntax error in options.
2344 */
2345
2346 static int
2347 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2348 {
2349 double limit, period, count;
2350 uschar *ss;
2351 uschar *key = NULL;
2352 uschar *unique = NULL;
2353 int sep = '/';
2354 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2355 BOOL noupdate = FALSE, badacl = FALSE;
2356 int mode = RATE_PER_WHAT;
2357 int old_pool, rc;
2358 tree_node **anchor, *t;
2359 open_db dbblock, *dbm;
2360 int dbdb_size;
2361 dbdata_ratelimit *dbd;
2362 dbdata_ratelimit_unique *dbdb;
2363 struct timeval tv;
2364
2365 /* Parse the first two options and record their values in expansion
2366 variables. These variables allow the configuration to have informative
2367 error messages based on rate limits obtained from a table lookup. */
2368
2369 /* First is the maximum number of messages per period / maximum burst
2370 size, which must be greater than or equal to zero. Zero is useful for
2371 rate measurement as opposed to rate limiting. */
2372
2373 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2374 if (sender_rate_limit == NULL)
2375 {
2376 limit = -1.0;
2377 ss = NULL; /* compiler quietening */
2378 }
2379 else
2380 {
2381 limit = Ustrtod(sender_rate_limit, &ss);
2382 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2383 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2384 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2385 }
2386 if (limit < 0.0 || *ss != '\0')
2387 return ratelimit_error(log_msgptr,
2388 "\"%s\" is not a positive number", sender_rate_limit);
2389
2390 /* Second is the rate measurement period / exponential smoothing time
2391 constant. This must be strictly greater than zero, because zero leads to
2392 run-time division errors. */
2393
2394 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2395 if (sender_rate_period == NULL) period = -1.0;
2396 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2397 if (period <= 0.0)
2398 return ratelimit_error(log_msgptr,
2399 "\"%s\" is not a time value", sender_rate_period);
2400
2401 /* By default we are counting one of something, but the per_rcpt,
2402 per_byte, and count options can change this. */
2403
2404 count = 1.0;
2405
2406 /* Parse the other options. */
2407
2408 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2409 != NULL)
2410 {
2411 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2412 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2413 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2414 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2415 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2416 else if (strcmpic(ss, US"per_conn") == 0)
2417 {
2418 RATE_SET(mode, PER_CONN);
2419 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2420 badacl = TRUE;
2421 }
2422 else if (strcmpic(ss, US"per_mail") == 0)
2423 {
2424 RATE_SET(mode, PER_MAIL);
2425 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2426 }
2427 else if (strcmpic(ss, US"per_rcpt") == 0)
2428 {
2429 /* If we are running in the RCPT ACL, then we'll count the recipients
2430 one by one, but if we are running when we have accumulated the whole
2431 list then we'll add them all in one batch. */
2432 if (where == ACL_WHERE_RCPT)
2433 RATE_SET(mode, PER_RCPT);
2434 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2435 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2436 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2437 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2438 }
2439 else if (strcmpic(ss, US"per_byte") == 0)
2440 {
2441 /* If we have not yet received the message data and there was no SIZE
2442 declaration on the MAIL comand, then it's safe to just use a value of
2443 zero and let the recorded rate decay as if nothing happened. */
2444 RATE_SET(mode, PER_MAIL);
2445 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2446 else count = message_size < 0 ? 0.0 : (double)message_size;
2447 }
2448 else if (strcmpic(ss, US"per_addr") == 0)
2449 {
2450 RATE_SET(mode, PER_RCPT);
2451 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2452 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2453 }
2454 else if (strncmpic(ss, US"count=", 6) == 0)
2455 {
2456 uschar *e;
2457 count = Ustrtod(ss+6, &e);
2458 if (count < 0.0 || *e != '\0')
2459 return ratelimit_error(log_msgptr,
2460 "\"%s\" is not a positive number", ss);
2461 }
2462 else if (strncmpic(ss, US"unique=", 7) == 0)
2463 unique = string_copy(ss + 7);
2464 else if (key == NULL)
2465 key = string_copy(ss);
2466 else
2467 key = string_sprintf("%s/%s", key, ss);
2468 }
2469
2470 /* Sanity check. When the badacl flag is set the update mode must either
2471 be readonly (which is the default if it is omitted) or, for backwards
2472 compatibility, a combination of noupdate and strict or leaky. */
2473
2474 if (mode == RATE_PER_CLASH)
2475 return ratelimit_error(log_msgptr, "conflicting per_* options");
2476 if (leaky + strict + readonly > 1)
2477 return ratelimit_error(log_msgptr, "conflicting update modes");
2478 if (badacl && (leaky || strict) && !noupdate)
2479 return ratelimit_error(log_msgptr,
2480 "\"%s\" must not have /leaky or /strict option in %s ACL",
2481 ratelimit_option_string[mode], acl_wherenames[where]);
2482
2483 /* Set the default values of any unset options. In readonly mode we
2484 perform the rate computation without any increment so that its value
2485 decays to eventually allow over-limit senders through. */
2486
2487 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2488 if (badacl) readonly = TRUE;
2489 if (readonly) count = 0.0;
2490 if (!strict && !readonly) leaky = TRUE;
2491 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2492
2493 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2494 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2495 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2496 are added to the key because they alter the meaning of the stored data. */
2497
2498 if (key == NULL)
2499 key = (sender_host_address == NULL)? US"" : sender_host_address;
2500
2501 key = string_sprintf("%s/%s/%s%s",
2502 sender_rate_period,
2503 ratelimit_option_string[mode],
2504 unique == NULL ? "" : "unique/",
2505 key);
2506
2507 HDEBUG(D_acl)
2508 debug_printf("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2509
2510 /* See if we have already computed the rate by looking in the relevant tree.
2511 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2512 pool so that they survive across resets. In readonly mode we only remember the
2513 result for the rest of this command in case a later command changes it. After
2514 this bit of logic the code is independent of the per_* mode. */
2515
2516 old_pool = store_pool;
2517
2518 if (readonly)
2519 anchor = &ratelimiters_cmd;
2520 else switch(mode) {
2521 case RATE_PER_CONN:
2522 anchor = &ratelimiters_conn;
2523 store_pool = POOL_PERM;
2524 break;
2525 case RATE_PER_BYTE:
2526 case RATE_PER_MAIL:
2527 case RATE_PER_ALLRCPTS:
2528 anchor = &ratelimiters_mail;
2529 break;
2530 case RATE_PER_ADDR:
2531 case RATE_PER_CMD:
2532 case RATE_PER_RCPT:
2533 anchor = &ratelimiters_cmd;
2534 break;
2535 default:
2536 anchor = NULL; /* silence an "unused" complaint */
2537 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2538 "internal ACL error: unknown ratelimit mode %d", mode);
2539 break;
2540 }
2541
2542 t = tree_search(*anchor, key);
2543 if (t != NULL)
2544 {
2545 dbd = t->data.ptr;
2546 /* The following few lines duplicate some of the code below. */
2547 rc = (dbd->rate < limit)? FAIL : OK;
2548 store_pool = old_pool;
2549 sender_rate = string_sprintf("%.1f", dbd->rate);
2550 HDEBUG(D_acl)
2551 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2552 return rc;
2553 }
2554
2555 /* We aren't using a pre-computed rate, so get a previously recorded rate
2556 from the database, which will be updated and written back if required. */
2557
2558 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2559 if (dbm == NULL)
2560 {
2561 store_pool = old_pool;
2562 sender_rate = NULL;
2563 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2564 *log_msgptr = US"ratelimit database not available";
2565 return DEFER;
2566 }
2567 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2568 dbd = NULL;
2569
2570 gettimeofday(&tv, NULL);
2571
2572 if (dbdb != NULL)
2573 {
2574 /* Locate the basic ratelimit block inside the DB data. */
2575 HDEBUG(D_acl) debug_printf("ratelimit found key in database\n");
2576 dbd = &dbdb->dbd;
2577
2578 /* Forget the old Bloom filter if it is too old, so that we count each
2579 repeating event once per period. We don't simply clear and re-use the old
2580 filter because we want its size to change if the limit changes. Note that
2581 we keep the dbd pointer for copying the rate into the new data block. */
2582
2583 if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period)
2584 {
2585 HDEBUG(D_acl) debug_printf("ratelimit discarding old Bloom filter\n");
2586 dbdb = NULL;
2587 }
2588
2589 /* Sanity check. */
2590
2591 if(unique != NULL && dbdb_size < sizeof(*dbdb))
2592 {
2593 HDEBUG(D_acl) debug_printf("ratelimit discarding undersize Bloom filter\n");
2594 dbdb = NULL;
2595 }
2596 }
2597
2598 /* Allocate a new data block if the database lookup failed
2599 or the Bloom filter passed its age limit. */
2600
2601 if (dbdb == NULL)
2602 {
2603 if (unique == NULL)
2604 {
2605 /* No Bloom filter. This basic ratelimit block is initialized below. */
2606 HDEBUG(D_acl) debug_printf("ratelimit creating new rate data block\n");
2607 dbdb_size = sizeof(*dbd);
2608 dbdb = store_get(dbdb_size);
2609 }
2610 else
2611 {
2612 int extra;
2613 HDEBUG(D_acl) debug_printf("ratelimit creating new Bloom filter\n");
2614
2615 /* See the long comment below for an explanation of the magic number 2.
2616 The filter has a minimum size in case the rate limit is very small;
2617 this is determined by the definition of dbdata_ratelimit_unique. */
2618
2619 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2620 if (extra < 0) extra = 0;
2621 dbdb_size = sizeof(*dbdb) + extra;
2622 dbdb = store_get(dbdb_size);
2623 dbdb->bloom_epoch = tv.tv_sec;
2624 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2625 memset(dbdb->bloom, 0, dbdb->bloom_size);
2626
2627 /* Preserve any basic ratelimit data (which is our longer-term memory)
2628 by copying it from the discarded block. */
2629
2630 if (dbd != NULL)
2631 {
2632 dbdb->dbd = *dbd;
2633 dbd = &dbdb->dbd;
2634 }
2635 }
2636 }
2637
2638 /* If we are counting unique events, find out if this event is new or not.
2639 If the client repeats the event during the current period then it should be
2640 counted. We skip this code in readonly mode for efficiency, because any
2641 changes to the filter will be discarded and because count is already set to
2642 zero. */
2643
2644 if (unique != NULL && !readonly)
2645 {
2646 /* We identify unique events using a Bloom filter. (You can find my
2647 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2648 With the per_addr option, an "event" is a recipient address, though the
2649 user can use the unique option to define their own events. We only count
2650 an event if we have not seen it before.
2651
2652 We size the filter according to the rate limit, which (in leaky mode)
2653 is the limit on the population of the filter. We allow 16 bits of space
2654 per entry (see the construction code above) and we set (up to) 8 of them
2655 when inserting an element (see the loop below). The probability of a false
2656 positive (an event we have not seen before but which we fail to count) is
2657
2658 size = limit * 16
2659 numhash = 8
2660 allzero = exp(-numhash * pop / size)
2661 = exp(-0.5 * pop / limit)
2662 fpr = pow(1 - allzero, numhash)
2663
2664 For senders at the limit the fpr is 0.06% or 1 in 1700
2665 and for senders at half the limit it is 0.0006% or 1 in 170000
2666
2667 In strict mode the Bloom filter can fill up beyond the normal limit, in
2668 which case the false positive rate will rise. This means that the
2669 measured rate for very fast senders can bogusly drop off after a while.
2670
2671 At twice the limit, the fpr is 2.5% or 1 in 40
2672 At four times the limit, it is 31% or 1 in 3.2
2673
2674 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2675 decay below the limit, and if this is more than one then the Bloom filter
2676 will be discarded before the decay gets that far. The false positive rate
2677 at this threshold is 9.3% or 1 in 10.7. */
2678
2679 BOOL seen;
2680 unsigned n, hash, hinc;
2681 uschar md5sum[16];
2682 md5 md5info;
2683
2684 /* Instead of using eight independent hash values, we combine two values
2685 using the formula h1 + n * h2. This does not harm the Bloom filter's
2686 performance, and means the amount of hash we need is independent of the
2687 number of bits we set in the filter. */
2688
2689 md5_start(&md5info);
2690 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2691 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2692 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2693
2694 /* Scan the bits corresponding to this event. A zero bit means we have
2695 not seen it before. Ensure all bits are set to record this event. */
2696
2697 HDEBUG(D_acl) debug_printf("ratelimit checking uniqueness of %s\n", unique);
2698
2699 seen = TRUE;
2700 for (n = 0; n < 8; n++, hash += hinc)
2701 {
2702 int bit = 1 << (hash % 8);
2703 int byte = (hash / 8) % dbdb->bloom_size;
2704 if ((dbdb->bloom[byte] & bit) == 0)
2705 {
2706 dbdb->bloom[byte] |= bit;
2707 seen = FALSE;
2708 }
2709 }
2710
2711 /* If this event has occurred before, do not count it. */
2712
2713 if (seen)
2714 {
2715 HDEBUG(D_acl) debug_printf("ratelimit event found in Bloom filter\n");
2716 count = 0.0;
2717 }
2718 else
2719 HDEBUG(D_acl) debug_printf("ratelimit event added to Bloom filter\n");
2720 }
2721
2722 /* If there was no previous ratelimit data block for this key, initialize
2723 the new one, otherwise update the block from the database. The initial rate
2724 is what would be computed by the code below for an infinite interval. */
2725
2726 if (dbd == NULL)
2727 {
2728 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's rate data\n");
2729 dbd = &dbdb->dbd;
2730 dbd->time_stamp = tv.tv_sec;
2731 dbd->time_usec = tv.tv_usec;
2732 dbd->rate = count;
2733 }
2734 else
2735 {
2736 /* The smoothed rate is computed using an exponentially weighted moving
2737 average adjusted for variable sampling intervals. The standard EWMA for
2738 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2739 where f() is the measured value and f'() is the smoothed value.
2740
2741 Old data decays out of the smoothed value exponentially, such that data n
2742 samples old is multiplied by a^n. The exponential decay time constant p
2743 is defined such that data p samples old is multiplied by 1/e, which means
2744 that a = exp(-1/p). We can maintain the same time constant for a variable
2745 sampling interval i by using a = exp(-i/p).
2746
2747 The rate we are measuring is messages per period, suitable for directly
2748 comparing with the limit. The average rate between now and the previous
2749 message is period / interval, which we feed into the EWMA as the sample.
2750
2751 It turns out that the number of messages required for the smoothed rate
2752 to reach the limit when they are sent in a burst is equal to the limit.
2753 This can be seen by analysing the value of the smoothed rate after N
2754 messages sent at even intervals. Let k = (1 - a) * p/i
2755
2756 rate_1 = (1 - a) * p/i + a * rate_0
2757 = k + a * rate_0
2758 rate_2 = k + a * rate_1
2759 = k + a * k + a^2 * rate_0
2760 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2761 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2762 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2763 = rate_0 * a^N + p/i * (1 - a^N)
2764
2765 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2766
2767 rate_N = p/i + (rate_0 - p/i) * a^N
2768 a^N = (rate_N - p/i) / (rate_0 - p/i)
2769 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2770 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2771
2772 Numerical analysis of the above equation, setting the computed rate to
2773 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2774 rates, p/i, the number of messages N = limit. So limit serves as both the
2775 maximum rate measured in messages per period, and the maximum number of
2776 messages that can be sent in a fast burst. */
2777
2778 double this_time = (double)tv.tv_sec
2779 + (double)tv.tv_usec / 1000000.0;
2780 double prev_time = (double)dbd->time_stamp
2781 + (double)dbd->time_usec / 1000000.0;
2782
2783 /* We must avoid division by zero, and deal gracefully with the clock going
2784 backwards. If we blunder ahead when time is in reverse then the computed
2785 rate will be bogus. To be safe we clamp interval to a very small number. */
2786
2787 double interval = this_time - prev_time <= 0.0 ? 1e-9
2788 : this_time - prev_time;
2789
2790 double i_over_p = interval / period;
2791 double a = exp(-i_over_p);
2792
2793 /* Combine the instantaneous rate (period / interval) with the previous rate
2794 using the smoothing factor a. In order to measure sized events, multiply the
2795 instantaneous rate by the count of bytes or recipients etc. */
2796
2797 dbd->time_stamp = tv.tv_sec;
2798 dbd->time_usec = tv.tv_usec;
2799 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2800
2801 /* When events are very widely spaced the computed rate tends towards zero.
2802 Although this is accurate it turns out not to be useful for our purposes,
2803 especially when the first event after a long silence is the start of a spam
2804 run. A more useful model is that the rate for an isolated event should be the
2805 size of the event per the period size, ignoring the lack of events outside
2806 the current period and regardless of where the event falls in the period. So,
2807 if the interval was so long that the calculated rate is unhelpfully small, we
2808 re-intialize the rate. In the absence of higher-rate bursts, the condition
2809 below is true if the interval is greater than the period. */
2810
2811 if (dbd->rate < count) dbd->rate = count;
2812 }
2813
2814 /* Clients sending at the limit are considered to be over the limit.
2815 This matters for edge cases such as a limit of zero, when the client
2816 should be completely blocked. */
2817
2818 rc = (dbd->rate < limit)? FAIL : OK;
2819
2820 /* Update the state if the rate is low or if we are being strict. If we
2821 are in leaky mode and the sender's rate is too high, we do not update
2822 the recorded rate in order to avoid an over-aggressive sender's retry
2823 rate preventing them from getting any email through. If readonly is set,
2824 neither leaky nor strict are set, so we do not do any updates. */
2825
2826 if ((rc == FAIL && leaky) || strict)
2827 {
2828 dbfn_write(dbm, key, dbdb, dbdb_size);
2829 HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
2830 }
2831 else
2832 {
2833 HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
2834 readonly? "readonly mode" : "over the limit, but leaky");
2835 }
2836
2837 dbfn_close(dbm);
2838
2839 /* Store the result in the tree for future reference. */
2840
2841 t = store_get(sizeof(tree_node) + Ustrlen(key));
2842 t->data.ptr = dbd;
2843 Ustrcpy(t->name, key);
2844 (void)tree_insertnode(anchor, t);
2845
2846 /* We create the formatted version of the sender's rate very late in
2847 order to ensure that it is done using the correct storage pool. */
2848
2849 store_pool = old_pool;
2850 sender_rate = string_sprintf("%.1f", dbd->rate);
2851
2852 HDEBUG(D_acl)
2853 debug_printf("ratelimit computed rate %s\n", sender_rate);
2854
2855 return rc;
2856 }
2857
2858
2859
2860 /*************************************************
2861 * The udpsend ACL modifier *
2862 *************************************************/
2863
2864 /* Called by acl_check_condition() below.
2865
2866 Arguments:
2867 arg the option string for udpsend=
2868 log_msgptr for error messages
2869
2870 Returns: OK - Completed.
2871 DEFER - Problem with DNS lookup.
2872 ERROR - Syntax error in options.
2873 */
2874
2875 static int
2876 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2877 {
2878 int sep = 0;
2879 uschar *hostname;
2880 uschar *portstr;
2881 uschar *portend;
2882 host_item *h;
2883 int portnum;
2884 int len;
2885 int r, s;
2886 uschar * errstr;
2887
2888 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2889 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2890
2891 if (hostname == NULL)
2892 {
2893 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2894 return ERROR;
2895 }
2896 if (portstr == NULL)
2897 {
2898 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2899 return ERROR;
2900 }
2901 if (arg == NULL)
2902 {
2903 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2904 return ERROR;
2905 }
2906 portnum = Ustrtol(portstr, &portend, 10);
2907 if (*portend != '\0')
2908 {
2909 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2910 return ERROR;
2911 }
2912
2913 /* Make a single-item host list. */
2914 h = store_get(sizeof(host_item));
2915 memset(h, 0, sizeof(host_item));
2916 h->name = hostname;
2917 h->port = portnum;
2918 h->mx = MX_NONE;
2919
2920 if (string_is_ip_address(hostname, NULL))
2921 h->address = hostname, r = HOST_FOUND;
2922 else
2923 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2924 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2925 {
2926 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2927 return DEFER;
2928 }
2929
2930 HDEBUG(D_acl)
2931 debug_printf("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2932
2933 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2934 1, NULL, &errstr);
2935 if (r < 0) goto defer;
2936 len = Ustrlen(arg);
2937 r = send(s, arg, len, 0);
2938 if (r < 0)
2939 {
2940 errstr = US strerror(errno);
2941 close(s);
2942 goto defer;
2943 }
2944 close(s);
2945 if (r < len)
2946 {
2947 *log_msgptr =
2948 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2949 return DEFER;
2950 }
2951
2952 HDEBUG(D_acl)
2953 debug_printf("udpsend %d bytes\n", r);
2954
2955 return OK;
2956
2957 defer:
2958 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2959 return DEFER;
2960 }
2961
2962
2963
2964 /*************************************************
2965 * Handle conditions/modifiers on an ACL item *
2966 *************************************************/
2967
2968 /* Called from acl_check() below.
2969
2970 Arguments:
2971 verb ACL verb
2972 cb ACL condition block - if NULL, result is OK
2973 where where called from
2974 addr the address being checked for RCPT, or NULL
2975 level the nesting level
2976 epp pointer to pass back TRUE if "endpass" encountered
2977 (applies only to "accept" and "discard")
2978 user_msgptr user message pointer
2979 log_msgptr log message pointer
2980 basic_errno pointer to where to put verify error
2981
2982 Returns: OK - all conditions are met
2983 DISCARD - an "acl" condition returned DISCARD - only allowed
2984 for "accept" or "discard" verbs
2985 FAIL - at least one condition fails
2986 FAIL_DROP - an "acl" condition returned FAIL_DROP
2987 DEFER - can't tell at the moment (typically, lookup defer,
2988 but can be temporary callout problem)
2989 ERROR - ERROR from nested ACL or expansion failure or other
2990 error
2991 */
2992
2993 static int
2994 acl_check_condition(int verb, acl_condition_block *cb, int where,
2995 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2996 uschar **log_msgptr, int *basic_errno)
2997 {
2998 uschar *user_message = NULL;
2999 uschar *log_message = NULL;
3000 uschar *debug_tag = NULL;
3001 uschar *debug_opts = NULL;
3002 int rc = OK;
3003 #ifdef WITH_CONTENT_SCAN
3004 int sep = -'/';
3005 #endif
3006
3007 for (; cb != NULL; cb = cb->next)
3008 {
3009 const uschar *arg;
3010 int control_type;
3011
3012 /* The message and log_message items set up messages to be used in
3013 case of rejection. They are expanded later. */
3014
3015 if (cb->type == ACLC_MESSAGE)
3016 {
3017 HDEBUG(D_acl) debug_printf(" message: %s\n", cb->arg);
3018 user_message = cb->arg;
3019 continue;
3020 }
3021
3022 if (cb->type == ACLC_LOG_MESSAGE)
3023 {
3024 HDEBUG(D_acl) debug_printf("l_message: %s\n", cb->arg);
3025 log_message = cb->arg;
3026 continue;
3027 }
3028
3029 /* The endpass "condition" just sets a flag to show it occurred. This is
3030 checked at compile time to be on an "accept" or "discard" item. */
3031
3032 if (cb->type == ACLC_ENDPASS)
3033 {
3034 *epp = TRUE;
3035 continue;
3036 }
3037
3038 /* For other conditions and modifiers, the argument is expanded now for some
3039 of them, but not for all, because expansion happens down in some lower level
3040 checking functions in some cases. */
3041
3042 if (cond_expand_at_top[cb->type])
3043 {
3044 arg = expand_string(cb->arg);
3045 if (arg == NULL)
3046 {
3047 if (expand_string_forcedfail) continue;
3048 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
3049 cb->arg, expand_string_message);
3050 return search_find_defer? DEFER : ERROR;
3051 }
3052 }
3053 else arg = cb->arg;
3054
3055 /* Show condition, and expanded condition if it's different */
3056
3057 HDEBUG(D_acl)
3058 {
3059 int lhswidth = 0;
3060 debug_printf("check %s%s %n",
3061 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
3062 conditions[cb->type], &lhswidth);
3063
3064 if (cb->type == ACLC_SET)
3065 {
3066 debug_printf("acl_%s ", cb->u.varname);
3067 lhswidth += 5 + Ustrlen(cb->u.varname);
3068 }
3069
3070 debug_printf("= %s\n", cb->arg);
3071
3072 if (arg != cb->arg)
3073 debug_printf("%.*s= %s\n", lhswidth,
3074 US" ", CS arg);
3075 }
3076
3077 /* Check that this condition makes sense at this time */
3078
3079 if ((cond_forbids[cb->type] & (1 << where)) != 0)
3080 {
3081 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
3082 cond_modifiers[cb->type]? "use" : "test",
3083 conditions[cb->type], acl_wherenames[where]);
3084 return ERROR;
3085 }
3086
3087 /* Run the appropriate test for each condition, or take the appropriate
3088 action for the remaining modifiers. */
3089
3090 switch(cb->type)
3091 {
3092 case ACLC_ADD_HEADER:
3093 setup_header(arg);
3094 break;
3095
3096 /* A nested ACL that returns "discard" makes sense only for an "accept" or
3097 "discard" verb. */
3098
3099 case ACLC_ACL:
3100 rc = acl_check_wargs(where, addr, arg, level+1, user_msgptr, log_msgptr);
3101 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
3102 {
3103 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
3104 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
3105 verbs[verb]);
3106 return ERROR;
3107 }
3108 break;
3109
3110 case ACLC_AUTHENTICATED:
3111 rc = (sender_host_authenticated == NULL)? FAIL :
3112 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
3113 TRUE, NULL);
3114 break;
3115
3116 #ifdef EXPERIMENTAL_BRIGHTMAIL
3117 case ACLC_BMI_OPTIN:
3118 {
3119 int old_pool = store_pool;
3120 store_pool = POOL_PERM;
3121 bmi_current_optin = string_copy(arg);
3122 store_pool = old_pool;
3123 }
3124 break;
3125 #endif
3126
3127 case ACLC_CONDITION:
3128 /* The true/false parsing here should be kept in sync with that used in
3129 expand.c when dealing with ECOND_BOOL so that we don't have too many
3130 different definitions of what can be a boolean. */
3131 if (*arg == '-'
3132 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
3133 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
3134 rc = (Uatoi(arg) == 0)? FAIL : OK;
3135 else
3136 rc = (strcmpic(arg, US"no") == 0 ||
3137 strcmpic(arg, US"false") == 0)? FAIL :
3138 (strcmpic(arg, US"yes") == 0 ||
3139 strcmpic(arg, US"true") == 0)? OK : DEFER;
3140 if (rc == DEFER)
3141 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3142 break;
3143
3144 case ACLC_CONTINUE: /* Always succeeds */
3145 break;
3146
3147 case ACLC_CONTROL:
3148 {
3149 const uschar *p = NULL;
3150 control_type = decode_control(arg, &p, where, log_msgptr);
3151
3152 /* Check if this control makes sense at this time */
3153
3154 if ((control_forbids[control_type] & (1 << where)) != 0)
3155 {
3156 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3157 controls[control_type], acl_wherenames[where]);
3158 return ERROR;
3159 }
3160
3161 switch(control_type)
3162 {
3163 case CONTROL_AUTH_UNADVERTISED:
3164 allow_auth_unadvertised = TRUE;
3165 break;
3166
3167 #ifdef EXPERIMENTAL_BRIGHTMAIL
3168 case CONTROL_BMI_RUN:
3169 bmi_run = 1;
3170 break;
3171 #endif
3172
3173 #ifndef DISABLE_DKIM
3174 case CONTROL_DKIM_VERIFY:
3175 dkim_disable_verify = TRUE;
3176 #ifdef EXPERIMENTAL_DMARC
3177 /* Since DKIM was blocked, skip DMARC too */
3178 dmarc_disable_verify = TRUE;
3179 dmarc_enable_forensic = FALSE;
3180 #endif
3181 break;
3182 #endif
3183
3184 #ifdef EXPERIMENTAL_DMARC
3185 case CONTROL_DMARC_VERIFY:
3186 dmarc_disable_verify = TRUE;
3187 break;
3188
3189 case CONTROL_DMARC_FORENSIC:
3190 dmarc_enable_forensic = TRUE;
3191 break;
3192 #endif
3193
3194 case CONTROL_DSCP:
3195 if (*p == '/')
3196 {
3197 int fd, af, level, optname, value;
3198 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3199 a socket; we can accept that, we'll just debug-log failures anyway. */
3200 fd = fileno(smtp_in);
3201 af = ip_get_address_family(fd);
3202 if (af < 0)
3203 {
3204 HDEBUG(D_acl)
3205 debug_printf("smtp input is probably not a socket [%s], not setting DSCP\n",
3206 strerror(errno));
3207 break;
3208 }
3209 if (dscp_lookup(p+1, af, &level, &optname, &value))
3210 {
3211 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3212 {
3213 HDEBUG(D_acl) debug_printf("failed to set input DSCP[%s]: %s\n",
3214 p+1, strerror(errno));
3215 }
3216 else
3217 {
3218 HDEBUG(D_acl) debug_printf("set input DSCP to \"%s\"\n", p+1);
3219 }
3220 }
3221 else
3222 {
3223 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3224 return ERROR;
3225 }
3226 }
3227 else
3228 {
3229 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3230 return ERROR;
3231 }
3232 break;
3233
3234 case CONTROL_ERROR:
3235 return ERROR;
3236
3237 case CONTROL_CASEFUL_LOCAL_PART:
3238 deliver_localpart = addr->cc_local_part;
3239 break;
3240
3241 case CONTROL_CASELOWER_LOCAL_PART:
3242 deliver_localpart = addr->lc_local_part;
3243 break;
3244
3245 case CONTROL_ENFORCE_SYNC:
3246 smtp_enforce_sync = TRUE;
3247 break;
3248
3249 case CONTROL_NO_ENFORCE_SYNC:
3250 smtp_enforce_sync = FALSE;
3251 break;
3252
3253 #ifdef WITH_CONTENT_SCAN
3254 case CONTROL_NO_MBOX_UNSPOOL:
3255 no_mbox_unspool = TRUE;
3256 break;
3257 #endif
3258
3259 case CONTROL_NO_MULTILINE:
3260 no_multiline_responses = TRUE;
3261 break;
3262
3263 case CONTROL_NO_PIPELINING:
3264 pipelining_enable = FALSE;
3265 break;
3266
3267 case CONTROL_NO_DELAY_FLUSH:
3268 disable_delay_flush = TRUE;
3269 break;
3270
3271 case CONTROL_NO_CALLOUT_FLUSH:
3272 disable_callout_flush = TRUE;
3273 break;
3274
3275 case CONTROL_FAKEREJECT:
3276 cancel_cutthrough_connection("fakereject");
3277 case CONTROL_FAKEDEFER:
3278 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3279 if (*p == '/')
3280 {
3281 const uschar *pp = p + 1;
3282 while (*pp != 0) pp++;
3283 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3284 p = pp;
3285 }
3286 else
3287 {
3288 /* Explicitly reset to default string */
3289 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).";
3290 }
3291 break;
3292
3293 case CONTROL_FREEZE:
3294 deliver_freeze = TRUE;
3295 deliver_frozen_at = time(NULL);
3296 freeze_tell = freeze_tell_config; /* Reset to configured value */
3297 if (Ustrncmp(p, "/no_tell", 8) == 0)
3298 {
3299 p += 8;
3300 freeze_tell = NULL;
3301 }
3302 if (*p != 0)
3303 {
3304 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3305 return ERROR;
3306 }
3307 cancel_cutthrough_connection("item frozen");
3308 break;
3309
3310 case CONTROL_QUEUE_ONLY:
3311 queue_only_policy = TRUE;
3312 cancel_cutthrough_connection("queueing forced");
3313 break;
3314
3315 case CONTROL_SUBMISSION:
3316 originator_name = US"";
3317 submission_mode = TRUE;
3318 while (*p == '/')
3319 {
3320 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3321 {
3322 p += 14;
3323 active_local_sender_retain = TRUE;
3324 active_local_from_check = FALSE;
3325 }
3326 else if (Ustrncmp(p, "/domain=", 8) == 0)
3327 {
3328 const uschar *pp = p + 8;
3329 while (*pp != 0 && *pp != '/') pp++;
3330 submission_domain = string_copyn(p+8, pp-p-8);
3331 p = pp;
3332 }
3333 /* The name= option must be last, because it swallows the rest of
3334 the string. */
3335 else if (Ustrncmp(p, "/name=", 6) == 0)
3336 {
3337 const uschar *pp = p + 6;
3338 while (*pp != 0) pp++;
3339 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3340 big_buffer, big_buffer_size));
3341 p = pp;
3342 }
3343 else break;
3344 }
3345 if (*p != 0)
3346 {
3347 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3348 return ERROR;
3349 }
3350 break;
3351
3352 case CONTROL_DEBUG:
3353 while (*p == '/')
3354 {
3355 if (Ustrncmp(p, "/tag=", 5) == 0)
3356 {
3357 const uschar *pp = p + 5;
3358 while (*pp != '\0' && *pp != '/') pp++;
3359 debug_tag = string_copyn(p+5, pp-p-5);
3360 p = pp;
3361 }
3362 else if (Ustrncmp(p, "/opts=", 6) == 0)
3363 {
3364 const uschar *pp = p + 6;
3365 while (*pp != '\0' && *pp != '/') pp++;
3366 debug_opts = string_copyn(p+6, pp-p-6);
3367 p = pp;
3368 }
3369 }
3370 debug_logging_activate(debug_tag, debug_opts);
3371 break;
3372
3373 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3374 suppress_local_fixups = TRUE;
3375 break;
3376
3377 case CONTROL_CUTTHROUGH_DELIVERY:
3378 #ifndef DISABLE_PRDR
3379 if (prdr_requested)
3380 #else
3381 if (0)
3382 #endif
3383 /* Too hard to think about for now. We might in future cutthrough
3384 the case where both sides handle prdr and this-node prdr acl
3385 is "accept" */
3386 *log_msgptr = string_sprintf("PRDR on %s reception\n", arg);
3387 else
3388 {
3389 if (deliver_freeze)
3390 *log_msgptr = US"frozen";
3391 else if (queue_only_policy)
3392 *log_msgptr = US"queue-only";
3393 else if (fake_response == FAIL)
3394 *log_msgptr = US"fakereject";
3395 else
3396 {
3397 if (rcpt_count == 1) cutthrough.delivery = TRUE;
3398 break;
3399 }
3400 *log_msgptr = string_sprintf("\"control=%s\" on %s item",
3401 arg, *log_msgptr);
3402 }
3403 return ERROR;
3404
3405 #ifdef SUPPORT_I18N
3406 case CONTROL_UTF8_DOWNCONVERT:
3407 if (*p == '/')
3408 {
3409 if (p[1] == '1')
3410 {
3411 message_utf8_downconvert = 1;
3412 addr->prop.utf8_downcvt = TRUE;
3413 addr->prop.utf8_downcvt_maybe = FALSE;
3414 p += 2;
3415 break;
3416 }
3417 if (p[1] == '0')
3418 {
3419 message_utf8_downconvert = 0;
3420 addr->prop.utf8_downcvt = FALSE;
3421 addr->prop.utf8_downcvt_maybe = FALSE;
3422 p += 2;
3423 break;
3424 }
3425 if (p[1] == '-' && p[2] == '1')
3426 {
3427 message_utf8_downconvert = -1;
3428 addr->prop.utf8_downcvt = FALSE;
3429 addr->prop.utf8_downcvt_maybe = TRUE;
3430 p += 3;
3431 break;
3432 }
3433 *log_msgptr = US"bad option value for control=utf8_downconvert";
3434 }
3435 else
3436 {
3437 message_utf8_downconvert = 1;
3438 addr->prop.utf8_downcvt = TRUE;
3439 addr->prop.utf8_downcvt_maybe = FALSE;
3440 break;
3441 }
3442 return ERROR;
3443 #endif
3444
3445 }
3446 break;
3447 }
3448
3449 #ifdef EXPERIMENTAL_DCC
3450 case ACLC_DCC:
3451 {
3452 /* Seperate the regular expression and any optional parameters. */
3453 const uschar * list = arg;
3454 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3455 /* Run the dcc backend. */
3456 rc = dcc_process(&ss);
3457 /* Modify return code based upon the existance of options. */
3458 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3459 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3460 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3461 }
3462 break;
3463 #endif
3464
3465 #ifdef WITH_CONTENT_SCAN
3466 case ACLC_DECODE:
3467 rc = mime_decode(&arg);
3468 break;
3469 #endif
3470
3471 case ACLC_DELAY:
3472 {
3473 int delay = readconf_readtime(arg, 0, FALSE);
3474 if (delay < 0)
3475 {
3476 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3477 "modifier: \"%s\" is not a time value", arg);
3478 return ERROR;
3479 }
3480 else
3481 {
3482 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
3483 delay);
3484 if (host_checking)
3485 {
3486 HDEBUG(D_acl)
3487 debug_printf("delay skipped in -bh checking mode\n");
3488 }
3489
3490 /* NOTE 1: Remember that we may be
3491 dealing with stdin/stdout here, in addition to TCP/IP connections.
3492 Also, delays may be specified for non-SMTP input, where smtp_out and
3493 smtp_in will be NULL. Whatever is done must work in all cases.
3494
3495 NOTE 2: The added feature of flushing the output before a delay must
3496 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3497 */
3498
3499 else
3500 {
3501 if (smtp_out != NULL && !disable_delay_flush)
3502 mac_smtp_fflush();
3503
3504 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3505 {
3506 struct pollfd p;
3507 nfds_t n = 0;
3508 if (smtp_out)
3509 {
3510 p.fd = fileno(smtp_out);
3511 p.events = POLLRDHUP;
3512 n = 1;
3513 }
3514 if (poll(&p, n, delay*1000) > 0)
3515 HDEBUG(D_acl) debug_printf("delay cancelled by peer close\n");
3516 }
3517 #else
3518 /* It appears to be impossible to detect that a TCP/IP connection has
3519 gone away without reading from it. This means that we cannot shorten
3520 the delay below if the client goes away, because we cannot discover
3521 that the client has closed its end of the connection. (The connection
3522 is actually in a half-closed state, waiting for the server to close its
3523 end.) It would be nice to be able to detect this state, so that the
3524 Exim process is not held up unnecessarily. However, it seems that we
3525 can't. The poll() function does not do the right thing, and in any case
3526 it is not always available.
3527 */
3528
3529 while (delay > 0) delay = sleep(delay);
3530 #endif
3531 }
3532 }
3533 }
3534 break;
3535
3536 #ifdef WITH_OLD_DEMIME
3537 case ACLC_DEMIME:
3538 rc = demime(&arg);
3539 break;
3540 #endif
3541
3542 #ifndef DISABLE_DKIM
3543 case ACLC_DKIM_SIGNER:
3544 if (dkim_cur_signer != NULL)
3545 rc = match_isinlist(dkim_cur_signer,
3546 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3547 else
3548 rc = FAIL;
3549 break;
3550
3551 case ACLC_DKIM_STATUS:
3552 rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS),
3553 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3554 break;
3555 #endif
3556
3557 #ifdef EXPERIMENTAL_DMARC
3558 case ACLC_DMARC_STATUS:
3559 if (!dmarc_has_been_checked)
3560 dmarc_process();
3561 dmarc_has_been_checked = TRUE;
3562 /* used long way of dmarc_exim_expand_query() in case we need more
3563 * view into the process in the future. */
3564 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3565 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3566 break;
3567 #endif
3568
3569 case ACLC_DNSLISTS:
3570 rc = verify_check_dnsbl(&arg);
3571 break;
3572
3573 case ACLC_DOMAINS:
3574 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3575 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3576 break;
3577
3578 /* The value in tls_cipher is the full cipher name, for example,
3579 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3580 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3581 what may in practice come out of the SSL library - which at the time of
3582 writing is poorly documented. */
3583
3584 case ACLC_ENCRYPTED:
3585 if (tls_in.cipher == NULL) rc = FAIL; else
3586 {
3587 uschar *endcipher = NULL;
3588 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3589 if (cipher == NULL) cipher = tls_in.cipher; else
3590 {
3591 endcipher = Ustrchr(++cipher, ':');
3592 if (endcipher != NULL) *endcipher = 0;
3593 }
3594 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3595 if (endcipher != NULL) *endcipher = ':';
3596 }
3597 break;
3598
3599 /* Use verify_check_this_host() instead of verify_check_host() so that
3600 we can pass over &host_data to catch any looked up data. Once it has been
3601 set, it retains its value so that it's still there if another ACL verb
3602 comes through here and uses the cache. However, we must put it into
3603 permanent store in case it is also expected to be used in a subsequent
3604 message in the same SMTP connection. */
3605
3606 case ACLC_HOSTS:
3607 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3608 (sender_host_address == NULL)? US"" : sender_host_address,
3609 CUSS &host_data);
3610 if (rc == DEFER) *log_msgptr = search_error_message;
3611 if (host_data) host_data = string_copy_malloc(host_data);
3612 break;
3613
3614 case ACLC_LOCAL_PARTS:
3615 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3616 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3617 CUSS &deliver_localpart_data);
3618 break;
3619
3620 case ACLC_LOG_REJECT_TARGET:
3621 {
3622 int logbits = 0;
3623 int sep = 0;
3624 const uschar *s = arg;
3625 uschar *ss;
3626 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3627 {
3628 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3629 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3630 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3631 else
3632 {
3633 logbits |= LOG_MAIN|LOG_REJECT;
3634 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3635 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3636 }
3637 }
3638 log_reject_target = logbits;
3639 }
3640 break;
3641
3642 case ACLC_LOGWRITE:
3643 {
3644 int logbits = 0;
3645 const uschar *s = arg;
3646 if (*s == ':')
3647 {
3648 s++;
3649 while (*s != ':')
3650 {
3651 if (Ustrncmp(s, "main", 4) == 0)
3652 { logbits |= LOG_MAIN; s += 4; }
3653 else if (Ustrncmp(s, "panic", 5) == 0)
3654 { logbits |= LOG_PANIC; s += 5; }
3655 else if (Ustrncmp(s, "reject", 6) == 0)
3656 { logbits |= LOG_REJECT; s += 6; }
3657 else
3658 {
3659 logbits = LOG_MAIN|LOG_PANIC;
3660 s = string_sprintf(":unknown log name in \"%s\" in "
3661 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3662 }
3663 if (*s == ',') s++;
3664 }
3665 s++;
3666 }
3667 while (isspace(*s)) s++;
3668
3669
3670 if (logbits == 0) logbits = LOG_MAIN;
3671 log_write(0, logbits, "%s", string_printing(s));
3672 }
3673 break;
3674
3675 #ifdef WITH_CONTENT_SCAN
3676 case ACLC_MALWARE: /* Run the malware backend. */
3677 {
3678 /* Separate the regular expression and any optional parameters. */
3679 const uschar * list = arg;
3680 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3681 uschar *opt;
3682 BOOL defer_ok = FALSE;
3683 int timeout = 0;
3684
3685 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3686 if (strcmpic(opt, US"defer_ok") == 0)
3687 defer_ok = TRUE;
3688 else if ( strncmpic(opt, US"tmo=", 4) == 0
3689 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3690 )
3691 {
3692 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3693 return ERROR;
3694 }
3695
3696 rc = malware(ss, timeout);
3697 if (rc == DEFER && defer_ok)
3698 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3699 }
3700 break;
3701
3702 case ACLC_MIME_REGEX:
3703 rc = mime_regex(&arg);
3704 break;
3705 #endif
3706
3707 case ACLC_RATELIMIT:
3708 rc = acl_ratelimit(arg, where, log_msgptr);
3709 break;
3710
3711 case ACLC_RECIPIENTS:
3712 rc = match_address_list((const uschar *)addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3713 CUSS &recipient_data);
3714 break;
3715
3716 #ifdef WITH_CONTENT_SCAN
3717 case ACLC_REGEX:
3718 rc = regex(&arg);
3719 break;
3720 #endif
3721
3722 case ACLC_REMOVE_HEADER:
3723 setup_remove_header(arg);
3724 break;
3725
3726 case ACLC_SENDER_DOMAINS:
3727 {
3728 uschar *sdomain;
3729 sdomain = Ustrrchr(sender_address, '@');
3730 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
3731 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3732 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3733 }
3734 break;
3735
3736 case ACLC_SENDERS:
3737 rc = match_address_list((const uschar *)sender_address, TRUE, TRUE, &arg,
3738 sender_address_cache, -1, 0, CUSS &sender_data);
3739 break;
3740
3741 /* Connection variables must persist forever */
3742
3743 case ACLC_SET:
3744 {
3745 int old_pool = store_pool;
3746 if ( cb->u.varname[0] == 'c'
3747 #ifndef DISABLE_EVENT
3748 || event_name /* An event is being delivered */
3749 #endif
3750 )
3751 store_pool = POOL_PERM;
3752 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3753 store_pool = old_pool;
3754 }
3755 break;
3756
3757 #ifdef WITH_CONTENT_SCAN
3758 case ACLC_SPAM:
3759 {
3760 /* Seperate the regular expression and any optional parameters. */
3761 const uschar * list = arg;
3762 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3763 /* Run the spam backend. */
3764 rc = spam(CUSS &ss);
3765 /* Modify return code based upon the existance of options. */
3766 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
3767 != NULL) {
3768 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3769 {
3770 /* FAIL so that the message is passed to the next ACL */
3771 rc = FAIL;
3772 }
3773 }
3774 }
3775 break;
3776 #endif
3777
3778 #ifdef EXPERIMENTAL_SPF
3779 case ACLC_SPF:
3780 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3781 break;
3782 case ACLC_SPF_GUESS:
3783 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3784 break;
3785 #endif
3786
3787 case ACLC_UDPSEND:
3788 rc = acl_udpsend(arg, log_msgptr);
3789 break;
3790
3791 /* If the verb is WARN, discard any user message from verification, because
3792 such messages are SMTP responses, not header additions. The latter come
3793 only from explicit "message" modifiers. However, put the user message into
3794 $acl_verify_message so it can be used in subsequent conditions or modifiers
3795 (until something changes it). */
3796
3797 case ACLC_VERIFY:
3798 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3799 if (*user_msgptr)
3800 acl_verify_message = *user_msgptr;
3801 if (verb == ACL_WARN) *user_msgptr = NULL;
3802 break;
3803
3804 default:
3805 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3806 "condition %d", cb->type);
3807 break;
3808 }
3809
3810 /* If a condition was negated, invert OK/FAIL. */
3811
3812 if (!cond_modifiers[cb->type] && cb->u.negated)
3813 {
3814 if (rc == OK) rc = FAIL;
3815 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3816 }
3817
3818 if (rc != OK) break; /* Conditions loop */
3819 }
3820
3821
3822 /* If the result is the one for which "message" and/or "log_message" are used,
3823 handle the values of these modifiers. If there isn't a log message set, we make
3824 it the same as the user message.
3825
3826 "message" is a user message that will be included in an SMTP response. Unless
3827 it is empty, it overrides any previously set user message.
3828
3829 "log_message" is a non-user message, and it adds to any existing non-user
3830 message that is already set.
3831
3832 Most verbs have but a single return for which the messages are relevant, but
3833 for "discard", it's useful to have the log message both when it succeeds and
3834 when it fails. For "accept", the message is used in the OK case if there is no
3835 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3836 present. */
3837
3838 if (*epp && rc == OK) user_message = NULL;
3839
3840 if (((1<<rc) & msgcond[verb]) != 0)
3841 {
3842 uschar *expmessage;
3843 uschar *old_user_msgptr = *user_msgptr;
3844 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3845
3846 /* If the verb is "warn", messages generated by conditions (verification or
3847 nested ACLs) are always discarded. This also happens for acceptance verbs
3848 when they actually do accept. Only messages specified at this level are used.
3849 However, the value of an existing message is available in $acl_verify_message
3850 during expansions. */
3851
3852 if (verb == ACL_WARN ||
3853 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3854 *log_msgptr = *user_msgptr = NULL;
3855
3856 if (user_message != NULL)
3857 {
3858 acl_verify_message = old_user_msgptr;
3859 expmessage = expand_string(user_message);
3860 if (expmessage == NULL)
3861 {
3862 if (!expand_string_forcedfail)
3863 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3864 user_message, expand_string_message);
3865 }
3866 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3867 }
3868
3869 if (log_message != NULL)
3870 {
3871 acl_verify_message = old_log_msgptr;
3872 expmessage = expand_string(log_message);
3873 if (expmessage == NULL)
3874 {
3875 if (!expand_string_forcedfail)
3876 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3877 log_message, expand_string_message);
3878 }
3879 else if (expmessage[0] != 0)
3880 {
3881 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3882 string_sprintf("%s: %s", expmessage, *log_msgptr);
3883 }
3884 }
3885
3886 /* If no log message, default it to the user message */
3887
3888 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3889 }
3890
3891 acl_verify_message = NULL;
3892 return rc;
3893 }
3894
3895
3896
3897
3898
3899 /*************************************************
3900 * Get line from a literal ACL *
3901 *************************************************/
3902
3903 /* This function is passed to acl_read() in order to extract individual lines
3904 of a literal ACL, which we access via static pointers. We can destroy the
3905 contents because this is called only once (the compiled ACL is remembered).
3906
3907 This code is intended to treat the data in the same way as lines in the main
3908 Exim configuration file. That is:
3909
3910 . Leading spaces are ignored.
3911
3912 . A \ at the end of a line is a continuation - trailing spaces after the \
3913 are permitted (this is because I don't believe in making invisible things
3914 significant). Leading spaces on the continued part of a line are ignored.
3915
3916 . Physical lines starting (significantly) with # are totally ignored, and
3917 may appear within a sequence of backslash-continued lines.
3918
3919 . Blank lines are ignored, but will end a sequence of continuations.
3920
3921 Arguments: none
3922 Returns: a pointer to the next line
3923 */
3924
3925
3926 static uschar *acl_text; /* Current pointer in the text */
3927 static uschar *acl_text_end; /* Points one past the terminating '0' */
3928
3929
3930 static uschar *
3931 acl_getline(void)
3932 {
3933 uschar *yield;
3934
3935 /* This loop handles leading blank lines and comments. */
3936
3937 for(;;)
3938 {
3939 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3940 if (*acl_text == 0) return NULL; /* No more data */
3941 yield = acl_text; /* Potential data line */
3942
3943 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3944
3945 /* If we hit the end before a newline, we have the whole logical line. If
3946 it's a comment, there's no more data to be given. Otherwise, yield it. */
3947
3948 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3949
3950 /* After reaching a newline, end this loop if the physical line does not
3951 start with '#'. If it does, it's a comment, and the loop continues. */
3952
3953 if (*yield != '#') break;
3954 }
3955
3956 /* This loop handles continuations. We know we have some real data, ending in
3957 newline. See if there is a continuation marker at the end (ignoring trailing
3958 white space). We know that *yield is not white space, so no need to test for
3959 cont > yield in the backwards scanning loop. */
3960
3961 for(;;)
3962 {
3963 uschar *cont;
3964 for (cont = acl_text - 1; isspace(*cont); cont--);
3965
3966 /* If no continuation follows, we are done. Mark the end of the line and
3967 return it. */
3968
3969 if (*cont != '\\')
3970 {
3971 *acl_text++ = 0;
3972 return yield;
3973 }
3974
3975 /* We have encountered a continuation. Skip over whitespace at the start of
3976 the next line, and indeed the whole of the next line or lines if they are
3977 comment lines. */
3978
3979 for (;;)
3980 {
3981 while (*(++acl_text) == ' ' || *acl_text == '\t');
3982 if (*acl_text != '#') break;
3983 while (*(++acl_text) != 0 && *acl_text != '\n');
3984 }
3985
3986 /* We have the start of a continuation line. Move all the rest of the data
3987 to join onto the previous line, and then find its end. If the end is not a
3988 newline, we are done. Otherwise loop to look for another continuation. */
3989
3990 memmove(cont, acl_text, acl_text_end - acl_text);
3991 acl_text_end -= acl_text - cont;
3992 acl_text = cont;
3993 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3994 if (*acl_text == 0) return yield;
3995 }
3996
3997 /* Control does not reach here */
3998 }
3999
4000
4001
4002
4003
4004 /*************************************************
4005 * Check access using an ACL *
4006 *************************************************/
4007
4008 /* This function is called from address_check. It may recurse via
4009 acl_check_condition() - hence the use of a level to stop looping. The ACL is
4010 passed as a string which is expanded. A forced failure implies no access check
4011 is required. If the result is a single word, it is taken as the name of an ACL
4012 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
4013 text, complete with newlines, and parsed as such. In both cases, the ACL check
4014 is then run. This function uses an auxiliary function for acl_read() to call
4015 for reading individual lines of a literal ACL. This is acl_getline(), which
4016 appears immediately above.
4017
4018 Arguments:
4019 where where called from
4020 addr address item when called from RCPT; otherwise NULL
4021 s the input string; NULL is the same as an empty ACL => DENY
4022 level the nesting level
4023 user_msgptr where to put a user error (for SMTP response)
4024 log_msgptr where to put a logging message (not for SMTP response)
4025
4026 Returns: OK access is granted
4027 DISCARD access is apparently granted...
4028 FAIL access is denied
4029 FAIL_DROP access is denied; drop the connection
4030 DEFER can't tell at the moment
4031 ERROR disaster
4032 */
4033
4034 static int
4035 acl_check_internal(int where, address_item *addr, uschar *s, int level,
4036 uschar **user_msgptr, uschar **log_msgptr)
4037 {
4038 int fd = -1;
4039 acl_block *acl = NULL;
4040 uschar *acl_name = US"inline ACL";
4041 uschar *ss;
4042
4043 /* Catch configuration loops */
4044
4045 if (level > 20)
4046 {
4047 *log_msgptr = US"ACL nested too deep: possible loop";
4048 return ERROR;
4049 }
4050
4051 if (s == NULL)
4052 {
4053 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
4054 return FAIL;
4055 }
4056
4057 /* At top level, we expand the incoming string. At lower levels, it has already
4058 been expanded as part of condition processing. */
4059
4060 if (level == 0)
4061 {
4062 ss = expand_string(s);
4063 if (ss == NULL)
4064 {
4065 if (expand_string_forcedfail) return OK;
4066 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
4067 expand_string_message);
4068 return ERROR;
4069 }
4070 }
4071 else ss = s;
4072
4073 while (isspace(*ss))ss++;
4074
4075 /* If we can't find a named ACL, the default is to parse it as an inline one.
4076 (Unless it begins with a slash; non-existent files give rise to an error.) */
4077
4078 acl_text = ss;
4079
4080 /* Handle the case of a string that does not contain any spaces. Look for a
4081 named ACL among those read from the configuration, or a previously read file.
4082 It is possible that the pointer to the ACL is NULL if the configuration
4083 contains a name with no data. If not found, and the text begins with '/',