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23c7ff99 | 1 | /* $Cambridge: exim/src/src/rda.c,v 1.2 2004/11/04 10:42:11 ph10 Exp $ */ |
059ec3d9 PH |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
7 | /* Copyright (c) University of Cambridge 1995 - 2004 */ | |
8 | /* See the file NOTICE for conditions of use and distribution. */ | |
9 | ||
10 | /* This module contains code for extracting addresses from a forwarding list | |
11 | (from an alias or forward file) or by running the filter interpreter. It may do | |
12 | this in a sub-process if a uid/gid are supplied. */ | |
13 | ||
14 | ||
15 | #include "exim.h" | |
16 | ||
17 | enum { FILE_EXIST, FILE_NOT_EXIST, FILE_EXIST_UNCLEAR }; | |
18 | ||
19 | #define REPLY_EXISTS 0x01 | |
20 | #define REPLY_EXPAND 0x02 | |
21 | #define REPLY_RETURN 0x04 | |
22 | ||
23 | ||
24 | /************************************************* | |
25 | * Check string for filter program * | |
26 | *************************************************/ | |
27 | ||
28 | /* This function checks whether a string is actually a filter program. The rule | |
29 | is that it must start with "# Exim filter ..." (any capitalization, spaces | |
30 | optional). It is envisaged that in future, other kinds of filter may be | |
31 | implemented. That's why it is implemented the way it is. The function is global | |
32 | because it is also called from filter.c when checking filters. | |
33 | ||
34 | Argument: the string | |
35 | ||
36 | Returns: FILTER_EXIM if it starts with "# Exim filter" | |
37 | FILTER_SIEVE if it starts with "# Sieve filter" | |
38 | FILTER_FORWARD otherwise | |
39 | */ | |
40 | ||
41 | /* This is an auxiliary function for matching a tag. */ | |
42 | ||
43 | static BOOL | |
44 | match_tag(const uschar *s, const uschar *tag) | |
45 | { | |
46 | for (; *tag != 0; s++, tag++) | |
47 | { | |
48 | if (*tag == ' ') | |
49 | { | |
50 | while (*s == ' ' || *s == '\t') s++; | |
51 | s--; | |
52 | } | |
53 | else if (tolower(*s) != tolower(*tag)) break; | |
54 | } | |
55 | return (*tag == 0); | |
56 | } | |
57 | ||
58 | /* This is the real function. It should be easy to add checking different | |
59 | tags for other types of filter. */ | |
60 | ||
61 | int | |
62 | rda_is_filter(const uschar *s) | |
63 | { | |
64 | while (isspace(*s)) s++; /* Skips initial blank lines */ | |
65 | if (match_tag(s, CUS"# exim filter")) return FILTER_EXIM; | |
66 | else if (match_tag(s, CUS"# sieve filter")) return FILTER_SIEVE; | |
67 | else return FILTER_FORWARD; | |
68 | } | |
69 | ||
70 | ||
71 | ||
72 | ||
73 | /************************************************* | |
74 | * Check for existence of file * | |
75 | *************************************************/ | |
76 | ||
77 | /* First of all, we stat the file. If this fails, we try to stat the enclosing | |
78 | directory, because a file in an unmounted NFS directory will look the same as a | |
79 | non-existent file. It seems that in Solaris 2.6, statting an entry in an | |
80 | indirect map that is currently unmounted does not cause the mount to happen. | |
81 | Instead, dummy data is returned, which defeats the whole point of this test. | |
82 | However, if a stat() is done on some object inside the directory, such as the | |
83 | "." back reference to itself, then the mount does occur. If an NFS host is | |
84 | taken offline, it is possible for the stat() to get stuck until it comes back. | |
85 | To guard against this, stick a timer round it. If we can't access the "." | |
86 | inside the directory, try the plain directory, just in case that helps. | |
87 | ||
88 | Argument: | |
89 | filename the file name | |
90 | error for message on error | |
91 | ||
92 | Returns: FILE_EXIST the file exists | |
93 | FILE_NOT_EXIST the file does not exist | |
94 | FILE_EXIST_UNCLEAR cannot determine existence | |
95 | */ | |
96 | ||
97 | static int | |
98 | rda_exists(uschar *filename, uschar **error) | |
99 | { | |
100 | int rc, saved_errno; | |
101 | uschar *slash; | |
102 | struct stat statbuf; | |
103 | ||
104 | if ((rc = Ustat(filename, &statbuf)) >= 0) return FILE_EXIST; | |
105 | saved_errno = errno; | |
106 | ||
107 | Ustrncpy(big_buffer, filename, big_buffer_size - 3); | |
108 | sigalrm_seen = FALSE; | |
109 | ||
110 | if (saved_errno == ENOENT) | |
111 | { | |
112 | slash = Ustrrchr(big_buffer, '/'); | |
113 | Ustrcpy(slash+1, "."); | |
114 | ||
115 | alarm(30); | |
116 | rc = Ustat(big_buffer, &statbuf); | |
117 | if (rc != 0 && errno == EACCES && !sigalrm_seen) | |
118 | { | |
119 | *slash = 0; | |
120 | rc = Ustat(big_buffer, &statbuf); | |
121 | } | |
122 | saved_errno = errno; | |
123 | alarm(0); | |
124 | ||
125 | DEBUG(D_route) debug_printf("stat(%s)=%d\n", big_buffer, rc); | |
126 | } | |
127 | ||
128 | if (sigalrm_seen || rc != 0) | |
129 | { | |
130 | *error = string_sprintf("failed to stat %s (%s)", big_buffer, | |
131 | sigalrm_seen? "timeout" : strerror(saved_errno)); | |
132 | return FILE_EXIST_UNCLEAR; | |
133 | } | |
134 | ||
135 | *error = string_sprintf("%s does not exist", filename); | |
136 | DEBUG(D_route) debug_printf("%s\n", *error); | |
137 | return FILE_NOT_EXIST; | |
138 | } | |
139 | ||
140 | ||
141 | ||
142 | /************************************************* | |
143 | * Get forwarding list from a file * | |
144 | *************************************************/ | |
145 | ||
146 | /* Open a file and read its entire contents into a block of memory. Certain | |
147 | opening errors are optionally treated the same as "file does not exist". | |
148 | ||
149 | ENOTDIR means that something along the line is not a directory: there are | |
150 | installations that set home directories to be /dev/null for non-login accounts | |
151 | but in normal circumstances this indicates some kind of configuration error. | |
152 | ||
153 | EACCES means there's a permissions failure. Some users turn off read permission | |
154 | on a .forward file to suspend forwarding, but this is probably an error in any | |
155 | kind of mailing list processing. | |
156 | ||
157 | The redirect block that contains the file name also contains constraints such | |
158 | as who may own the file, and mode bits that must not be set. This function is | |
159 | ||
160 | Arguments: | |
161 | rdata rdirect block, containing file name and constraints | |
162 | options for the RDO_ENOTDIR and RDO_EACCES options | |
163 | error where to put an error message | |
164 | yield what to return from rda_interpret on error | |
165 | ||
166 | Returns: pointer to string in store; NULL on error | |
167 | */ | |
168 | ||
169 | static uschar * | |
170 | rda_get_file_contents(redirect_block *rdata, int options, uschar **error, | |
171 | int *yield) | |
172 | { | |
173 | FILE *fwd; | |
174 | uschar *filebuf; | |
175 | uschar *filename = rdata->string; | |
176 | BOOL uid_ok = !rdata->check_owner; | |
177 | BOOL gid_ok = !rdata->check_group; | |
178 | struct stat statbuf; | |
179 | ||
180 | /* Attempt to open the file. If it appears not to exist, check up on the | |
181 | containing directory by statting it. If the directory does not exist, we treat | |
182 | this situation as an error (which will cause delivery to defer); otherwise we | |
183 | pass back FF_NONEXIST, which causes the redirect router to decline. | |
184 | ||
185 | However, if the ignore_enotdir option is set (to ignore "something on the | |
186 | path is not a directory" errors), the right behaviour seems to be not to do the | |
187 | directory test. */ | |
188 | ||
189 | fwd = Ufopen(filename, "rb"); | |
190 | if (fwd == NULL) | |
191 | { | |
192 | switch(errno) | |
193 | { | |
194 | case ENOENT: /* File does not exist */ | |
195 | DEBUG(D_route) debug_printf("%s does not exist\n%schecking parent directory\n", | |
196 | filename, | |
197 | ((options & RDO_ENOTDIR) != 0)? "ignore_enotdir set => skip " : ""); | |
198 | *yield = (((options & RDO_ENOTDIR) != 0) || | |
199 | rda_exists(filename, error) == FILE_NOT_EXIST)? | |
200 | FF_NONEXIST : FF_ERROR; | |
201 | return NULL; | |
202 | ||
203 | case ENOTDIR: /* Something on the path isn't a directory */ | |
204 | if ((options & RDO_ENOTDIR) == 0) goto DEFAULT_ERROR; | |
205 | DEBUG(D_route) debug_printf("non-directory on path %s: file assumed not to " | |
206 | "exist\n", filename); | |
207 | *yield = FF_NONEXIST; | |
208 | return NULL; | |
209 | ||
210 | case EACCES: /* Permission denied */ | |
211 | if ((options & RDO_EACCES) == 0) goto DEFAULT_ERROR; | |
212 | DEBUG(D_route) debug_printf("permission denied for %s: file assumed not to " | |
213 | "exist\n", filename); | |
214 | *yield = FF_NONEXIST; | |
215 | return NULL; | |
216 | ||
217 | DEFAULT_ERROR: | |
218 | default: | |
219 | *error = string_open_failed(errno, "%s", filename); | |
220 | *yield = FF_ERROR; | |
221 | return NULL; | |
222 | } | |
223 | } | |
224 | ||
225 | /* Check that we have a regular file. */ | |
226 | ||
227 | if (fstat(fileno(fwd), &statbuf) != 0) | |
228 | { | |
229 | *error = string_sprintf("failed to stat %s: %s", filename, strerror(errno)); | |
230 | goto ERROR_RETURN; | |
231 | } | |
232 | ||
233 | if ((statbuf.st_mode & S_IFMT) != S_IFREG) | |
234 | { | |
235 | *error = string_sprintf("%s is not a regular file", filename); | |
236 | goto ERROR_RETURN; | |
237 | } | |
238 | ||
239 | /* Check for unwanted mode bits */ | |
240 | ||
241 | if ((statbuf.st_mode & rdata->modemask) != 0) | |
242 | { | |
243 | *error = string_sprintf("bad mode (0%o) for %s: 0%o bit(s) unexpected", | |
244 | statbuf.st_mode, filename, statbuf.st_mode & rdata->modemask); | |
245 | goto ERROR_RETURN; | |
246 | } | |
247 | ||
248 | /* Check the file owner and file group if required to do so. */ | |
249 | ||
250 | if (!uid_ok) | |
251 | { | |
252 | if (rdata->pw != NULL && statbuf.st_uid == rdata->pw->pw_uid) | |
253 | uid_ok = TRUE; | |
254 | else if (rdata->owners != NULL) | |
255 | { | |
256 | int i; | |
257 | for (i = 1; i <= (int)(rdata->owners[0]); i++) | |
258 | if (rdata->owners[i] == statbuf.st_uid) { uid_ok = TRUE; break; } | |
259 | } | |
260 | } | |
261 | ||
262 | if (!gid_ok) | |
263 | { | |
264 | if (rdata->pw != NULL && statbuf.st_gid == rdata->pw->pw_gid) | |
265 | gid_ok = TRUE; | |
266 | else if (rdata->owngroups != NULL) | |
267 | { | |
268 | int i; | |
269 | for (i = 1; i <= (int)(rdata->owngroups[0]); i++) | |
270 | if (rdata->owngroups[i] == statbuf.st_gid) { gid_ok = TRUE; break; } | |
271 | } | |
272 | } | |
273 | ||
274 | if (!uid_ok || !gid_ok) | |
275 | { | |
276 | *error = string_sprintf("bad %s for %s", uid_ok? "group" : "owner", filename); | |
277 | goto ERROR_RETURN; | |
278 | } | |
279 | ||
280 | /* Put an upper limit on the size of the file, just to stop silly people | |
281 | feeding in ridiculously large files, which can easily be created by making | |
282 | files that have holes in them. */ | |
283 | ||
284 | if (statbuf.st_size > MAX_FILTER_SIZE) | |
285 | { | |
286 | *error = string_sprintf("%s is too big (max %d)", filename, MAX_FILTER_SIZE); | |
287 | goto ERROR_RETURN; | |
288 | } | |
289 | ||
290 | /* Read the file in one go in order to minimize the time we have it open. */ | |
291 | ||
292 | filebuf = store_get(statbuf.st_size + 1); | |
293 | ||
294 | if (fread(filebuf, 1, statbuf.st_size, fwd) != statbuf.st_size) | |
295 | { | |
296 | *error = string_sprintf("error while reading %s: %s", | |
297 | filename, strerror(errno)); | |
298 | goto ERROR_RETURN; | |
299 | } | |
300 | filebuf[statbuf.st_size] = 0; | |
301 | ||
302 | /* Don't pass statbuf.st_size directly to debug_printf. On some systems it | |
303 | is a long, which may not be the same as an int. */ | |
304 | ||
305 | DEBUG(D_route) | |
306 | { | |
307 | int size = (int)statbuf.st_size; | |
308 | debug_printf("%d bytes read from %s\n", size, filename); | |
309 | } | |
310 | ||
311 | fclose(fwd); | |
312 | return filebuf; | |
313 | ||
314 | /* Return an error: the string is already set up. */ | |
315 | ||
316 | ERROR_RETURN: | |
317 | *yield = FF_ERROR; | |
318 | fclose(fwd); | |
319 | return NULL; | |
320 | } | |
321 | ||
322 | ||
323 | ||
324 | /************************************************* | |
325 | * Extract info from list or filter * | |
326 | *************************************************/ | |
327 | ||
328 | /* This function calls the appropriate function to extract addresses from a | |
329 | forwarding list, or to run a filter file and get addresses from there. | |
330 | ||
331 | Arguments: | |
332 | rdata the redirection block | |
333 | options the options bits | |
334 | include_directory restrain to this directory | |
335 | sieve_vacation_directory passed to sieve_interpret | |
336 | generated where to hang generated addresses | |
337 | error for error messages | |
338 | eblockp for details of skipped syntax errors | |
339 | (NULL => no skip) | |
340 | filtertype set to the filter type: | |
341 | FILTER_FORWARD => a traditional .forward file | |
342 | FILTER_EXIM => an Exim filter file | |
343 | FILTER_SIEVE => a Sieve filter file | |
344 | a system filter is always forced to be FILTER_EXIM | |
345 | ||
346 | Returns: a suitable return for rda_interpret() | |
347 | */ | |
348 | ||
349 | static int | |
350 | rda_extract(redirect_block *rdata, int options, uschar *include_directory, | |
351 | uschar *sieve_vacation_directory, address_item **generated, uschar **error, | |
352 | error_block **eblockp, int *filtertype) | |
353 | { | |
354 | uschar *data; | |
355 | ||
356 | if (rdata->isfile) | |
357 | { | |
358 | int yield; | |
359 | data = rda_get_file_contents(rdata, options, error, &yield); | |
360 | if (data == NULL) return yield; | |
361 | } | |
362 | else data = rdata->string; | |
363 | ||
364 | *filtertype = system_filtering? FILTER_EXIM : rda_is_filter(data); | |
365 | ||
366 | /* Filter interpretation is done by a general function that is also called from | |
367 | the filter testing option (-bf). There are two versions: one for Exim filtering | |
368 | and one for Sieve filtering. Several features of string expansion may be locked | |
369 | out at sites that don't trust users. This is done by setting flags in | |
370 | expand_forbid that the expander inspects. */ | |
371 | ||
372 | if (*filtertype != FILTER_FORWARD) | |
373 | { | |
374 | int frc; | |
375 | int old_expand_forbid = expand_forbid; | |
376 | ||
23c7ff99 PH |
377 | DEBUG(D_route) debug_printf("data is %s filter program\n", |
378 | (*filtertype == FILTER_EXIM)? "an Exim" : "a Sieve"); | |
379 | ||
380 | /* RDO_FILTER is an "allow" bit */ | |
381 | ||
059ec3d9 PH |
382 | if ((options & RDO_FILTER) == 0) |
383 | { | |
384 | *error = US"filtering not enabled"; | |
385 | return FF_ERROR; | |
386 | } | |
387 | ||
059ec3d9 PH |
388 | expand_forbid = |
389 | (expand_forbid & ~RDO_FILTER_EXPANSIONS) | | |
390 | (options & RDO_FILTER_EXPANSIONS); | |
23c7ff99 PH |
391 | |
392 | /* RDO_{EXIM,SIEVE}_FILTER are forbid bits */ | |
393 | ||
394 | if (*filtertype == FILTER_EXIM) | |
395 | { | |
396 | if ((options & RDO_EXIM_FILTER) != 0) | |
397 | { | |
398 | *error = US"Exim filtering not enabled"; | |
399 | return FF_ERROR; | |
400 | } | |
401 | frc = filter_interpret(data, options, generated, error); | |
402 | } | |
403 | else | |
404 | { | |
405 | if ((options & RDO_SIEVE_FILTER) != 0) | |
406 | { | |
407 | *error = US"Sieve filtering not enabled"; | |
408 | return FF_ERROR; | |
409 | } | |
410 | frc = sieve_interpret(data, options, sieve_vacation_directory, generated, | |
411 | error); | |
412 | } | |
059ec3d9 PH |
413 | |
414 | expand_forbid = old_expand_forbid; | |
415 | return frc; | |
416 | } | |
417 | ||
418 | /* Not a filter script */ | |
419 | ||
420 | DEBUG(D_route) debug_printf("file is not a filter file\n"); | |
421 | ||
422 | return parse_forward_list(data, | |
423 | options, /* specials that are allowed */ | |
424 | generated, /* where to hang them */ | |
425 | error, /* for errors */ | |
426 | deliver_domain, /* to qualify \name */ | |
427 | include_directory, /* restrain to directory */ | |
428 | eblockp); /* for skipped syntax errors */ | |
429 | } | |
430 | ||
431 | ||
432 | ||
433 | ||
434 | /************************************************* | |
435 | * Write string down pipe * | |
436 | *************************************************/ | |
437 | ||
438 | /* This function is used for tranferring a string down a pipe between | |
439 | processes. If the pointer is NULL, a length of zero is written. | |
440 | ||
441 | Arguments: | |
442 | fd the pipe | |
443 | s the string | |
444 | ||
445 | Returns: nothing | |
446 | */ | |
447 | ||
448 | static void | |
449 | rda_write_string(int fd, uschar *s) | |
450 | { | |
451 | int len = (s == NULL)? 0 : Ustrlen(s) + 1; | |
452 | write(fd, &len, sizeof(int)); | |
453 | if (s != NULL) write(fd, s, len); | |
454 | } | |
455 | ||
456 | ||
457 | ||
458 | /************************************************* | |
459 | * Read string from pipe * | |
460 | *************************************************/ | |
461 | ||
462 | /* This function is used for receiving a string from a pipe. | |
463 | ||
464 | Arguments: | |
465 | fd the pipe | |
466 | sp where to put the string | |
467 | ||
468 | Returns: FALSE if data missing | |
469 | */ | |
470 | ||
471 | static BOOL | |
472 | rda_read_string(int fd, uschar **sp) | |
473 | { | |
474 | int len; | |
475 | ||
476 | if (read(fd, &len, sizeof(int)) != sizeof(int)) return FALSE; | |
477 | if (len == 0) *sp = NULL; else | |
478 | { | |
479 | *sp = store_get(len); | |
480 | if (read(fd, *sp, len) != len) return FALSE; | |
481 | } | |
482 | return TRUE; | |
483 | } | |
484 | ||
485 | ||
486 | ||
487 | /************************************************* | |
488 | * Interpret forward list or filter * | |
489 | *************************************************/ | |
490 | ||
491 | /* This function is passed a forward list string (unexpanded) or the name of a | |
492 | file (unexpanded) whose contents are the forwarding list. The list may in fact | |
493 | be a filter program if it starts with "#Exim filter" or "#Sieve filter". Other | |
494 | types of filter, with different inital tag strings, may be introduced in due | |
495 | course. | |
496 | ||
497 | The job of the function is to process the forwarding list or filter. It is | |
498 | pulled out into this separate function, because it is used for system filter | |
499 | files as well as from the redirect router. | |
500 | ||
501 | If the function is given a uid/gid, it runs a subprocess that passes the | |
502 | results back via a pipe. This provides security for things like :include:s in | |
503 | users' .forward files, and "logwrite" calls in users' filter files. A | |
504 | sub-process is NOT used when: | |
505 | ||
506 | . No uid/gid is provided | |
507 | . The input is a string which is not a filter string, and does not contain | |
508 | :include: | |
509 | . The input is a file whose non-existence can be detected in the main | |
510 | process (which is usually running as root). | |
511 | ||
512 | Arguments: | |
513 | rdata redirect data (file + constraints, or data string) | |
514 | options options to pass to the extraction functions, | |
515 | plus ENOTDIR and EACCES handling bits | |
516 | include_directory restrain :include: to this directory | |
517 | sieve_vacation_directory directory passed to sieve_interpret() | |
518 | ugid uid/gid to run under - if NULL, no change | |
519 | generated where to hang generated addresses, initially NULL | |
520 | error pointer for error message | |
521 | eblockp for skipped syntax errors; NULL if no skipping | |
522 | filtertype set to the type of file: | |
523 | FILTER_FORWARD => traditional .forward file | |
524 | FILTER_EXIM => an Exim filter file | |
525 | FILTER_SIEVE => a Sieve filter file | |
526 | a system filter is always forced to be FILTER_EXIM | |
527 | rname router name for error messages in the format | |
528 | "xxx router" or "system filter" | |
529 | ||
530 | Returns: values from extraction function, or FF_NONEXIST: | |
531 | FF_DELIVERED success, a significant action was taken | |
532 | FF_NOTDELIVERED success, no significant action | |
533 | FF_BLACKHOLE :blackhole: | |
534 | FF_DEFER defer requested | |
535 | FF_FAIL fail requested | |
536 | FF_INCLUDEFAIL some problem with :include: | |
537 | FF_FREEZE freeze requested | |
538 | FF_ERROR there was a problem | |
539 | FF_NONEXIST the file does not exist | |
540 | */ | |
541 | ||
542 | int | |
543 | rda_interpret(redirect_block *rdata, int options, uschar *include_directory, | |
544 | uschar *sieve_vacation_directory, ugid_block *ugid, address_item **generated, | |
545 | uschar **error, error_block **eblockp, int *filtertype, uschar *rname) | |
546 | { | |
547 | int fd, rc, pfd[2]; | |
548 | int yield, status; | |
549 | BOOL had_disaster = FALSE; | |
550 | pid_t pid; | |
551 | uschar *data; | |
552 | uschar *readerror = US""; | |
553 | void (*oldsignal)(int); | |
554 | ||
555 | DEBUG(D_route) debug_printf("rda_interpret (%s): %s\n", | |
556 | (rdata->isfile)? "file" : "string", rdata->string); | |
557 | ||
558 | /* Do the expansions of the file name or data first, while still privileged. */ | |
559 | ||
560 | data = expand_string(rdata->string); | |
561 | if (data == NULL) | |
562 | { | |
563 | if (expand_string_forcedfail) return FF_NOTDELIVERED; | |
564 | *error = string_sprintf("failed to expand \"%s\": %s", rdata->string, | |
565 | expand_string_message); | |
566 | return FF_ERROR; | |
567 | } | |
568 | rdata->string = data; | |
569 | ||
570 | DEBUG(D_route) debug_printf("expanded: %s\n", data); | |
571 | ||
572 | if (rdata->isfile && data[0] != '/') | |
573 | { | |
574 | *error = string_sprintf("\"%s\" is not an absolute path", data); | |
575 | return FF_ERROR; | |
576 | } | |
577 | ||
578 | /* If no uid/gid are supplied, or if we have a data string which does not start | |
579 | with #Exim filter or #Sieve filter, and does not contain :include:, do all the | |
580 | work in this process. Note that for a system filter, we always have a file, so | |
581 | the work is done in this process only if no user is supplied. */ | |
582 | ||
583 | if (!ugid->uid_set || /* Either there's no uid, or */ | |
584 | (!rdata->isfile && /* We've got the data, and */ | |
585 | rda_is_filter(data) == FILTER_FORWARD && /* It's not a filter script, */ | |
586 | Ustrstr(data, ":include:") == NULL)) /* and there's no :include: */ | |
587 | { | |
588 | return rda_extract(rdata, options, include_directory, | |
589 | sieve_vacation_directory, generated, error, eblockp, filtertype); | |
590 | } | |
591 | ||
592 | /* We need to run the processing code in a sub-process. However, if we can | |
593 | determine the non-existence of a file first, we can decline without having to | |
594 | create the sub-process. */ | |
595 | ||
596 | if (rdata->isfile && rda_exists(data, error) == FILE_NOT_EXIST) | |
597 | return FF_NONEXIST; | |
598 | ||
599 | /* If the file does exist, or we can't tell (non-root mounted NFS directory) | |
600 | we have to create the subprocess to do everything as the given user. The | |
601 | results of processing are passed back via a pipe. */ | |
602 | ||
603 | if (pipe(pfd) != 0) | |
604 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "creation of pipe for filter or " | |
605 | ":include: failed for %s: %s", rname, strerror(errno)); | |
606 | ||
607 | /* Ensure that SIGCHLD is set to SIG_DFL before forking, so that the child | |
608 | process can be waited for. We sometimes get here with it set otherwise. Save | |
609 | the old state for resetting on the wait. */ | |
610 | ||
611 | oldsignal = signal(SIGCHLD, SIG_DFL); | |
612 | if ((pid = fork()) == 0) | |
613 | { | |
614 | header_line *waslast = header_last; /* Save last header */ | |
615 | ||
616 | fd = pfd[pipe_write]; | |
617 | close(pfd[pipe_read]); | |
618 | exim_setugid(ugid->uid, ugid->gid, FALSE, rname); | |
619 | ||
620 | /* Addresses can get rewritten in filters; if we are not root or the exim | |
621 | user (and we probably are not), turn off rewrite logging, because we cannot | |
622 | write to the log now. */ | |
623 | ||
624 | if (ugid->uid != root_uid && ugid->uid != exim_uid) | |
625 | { | |
626 | DEBUG(D_rewrite) debug_printf("turned off address rewrite logging (not " | |
627 | "root or exim in this process)\n"); | |
628 | log_write_selector &= ~L_address_rewrite; | |
629 | } | |
630 | ||
631 | /* Now do the business */ | |
632 | ||
633 | yield = rda_extract(rdata, options, include_directory, | |
634 | sieve_vacation_directory, generated, error, eblockp, filtertype); | |
635 | ||
636 | /* Pass back whether it was a filter, and the return code and any overall | |
637 | error text via the pipe. */ | |
638 | ||
639 | write(fd, filtertype, sizeof(int)); | |
640 | write(fd, &yield, sizeof(int)); | |
641 | rda_write_string(fd, *error); | |
642 | ||
643 | /* Pass back the contents of any syntax error blocks if we have a pointer */ | |
644 | ||
645 | if (eblockp != NULL) | |
646 | { | |
647 | error_block *ep; | |
648 | for (ep = *eblockp; ep != NULL; ep = ep->next) | |
649 | { | |
650 | rda_write_string(fd, ep->text1); | |
651 | rda_write_string(fd, ep->text2); | |
652 | } | |
653 | rda_write_string(fd, NULL); /* Indicates end of eblocks */ | |
654 | } | |
655 | ||
656 | /* If this is a system filter, we have to pass back the numbers of any | |
657 | original header lines that were removed, and then any header lines that were | |
658 | added but not subsequently removed. */ | |
659 | ||
660 | if (system_filtering) | |
661 | { | |
662 | int i = 0; | |
663 | header_line *h; | |
664 | for (h = header_list; h != waslast->next; i++, h = h->next) | |
665 | { | |
666 | if (h->type == htype_old) write(fd, &i, sizeof(i)); | |
667 | } | |
668 | i = -1; | |
669 | write(fd, &i, sizeof(i)); | |
670 | ||
671 | while (waslast != header_last) | |
672 | { | |
673 | waslast = waslast->next; | |
674 | if (waslast->type != htype_old) | |
675 | { | |
676 | rda_write_string(fd, waslast->text); | |
677 | write(fd, &(waslast->type), sizeof(waslast->type)); | |
678 | } | |
679 | } | |
680 | rda_write_string(fd, NULL); /* Indicates end of added headers */ | |
681 | } | |
682 | ||
683 | /* Write the contents of the $n variables */ | |
684 | ||
685 | write(fd, filter_n, sizeof(filter_n)); | |
686 | ||
687 | /* If the result was DELIVERED or NOTDELIVERED, we pass back the generated | |
688 | addresses, and their associated information, through the pipe. This is | |
689 | just tedious, but it seems to be the only safe way. We do this also for | |
690 | FAIL and FREEZE, because a filter is allowed to set up deliveries that | |
691 | are honoured before freezing or failing. */ | |
692 | ||
693 | if (yield == FF_DELIVERED || yield == FF_NOTDELIVERED || | |
694 | yield == FF_FAIL || yield == FF_FREEZE) | |
695 | { | |
696 | address_item *addr; | |
697 | for (addr = *generated; addr != NULL; addr = addr->next) | |
698 | { | |
699 | int reply_options = 0; | |
700 | ||
701 | rda_write_string(fd, addr->address); | |
702 | write(fd, &(addr->mode), sizeof(addr->mode)); | |
703 | write(fd, &(addr->flags), sizeof(addr->flags)); | |
704 | rda_write_string(fd, addr->p.errors_address); | |
705 | ||
706 | if (addr->pipe_expandn != NULL) | |
707 | { | |
708 | uschar **pp; | |
709 | for (pp = addr->pipe_expandn; *pp != NULL; pp++) | |
710 | rda_write_string(fd, *pp); | |
711 | } | |
712 | rda_write_string(fd, NULL); | |
713 | ||
714 | if (addr->reply == NULL) | |
715 | write(fd, &reply_options, sizeof(int)); /* 0 means no reply */ | |
716 | else | |
717 | { | |
718 | reply_options |= REPLY_EXISTS; | |
719 | if (addr->reply->file_expand) reply_options |= REPLY_EXPAND; | |
720 | if (addr->reply->return_message) reply_options |= REPLY_RETURN; | |
721 | write(fd, &reply_options, sizeof(int)); | |
722 | write(fd, &(addr->reply->expand_forbid), sizeof(int)); | |
723 | write(fd, &(addr->reply->once_repeat), sizeof(time_t)); | |
724 | rda_write_string(fd, addr->reply->to); | |
725 | rda_write_string(fd, addr->reply->cc); | |
726 | rda_write_string(fd, addr->reply->bcc); | |
727 | rda_write_string(fd, addr->reply->from); | |
728 | rda_write_string(fd, addr->reply->reply_to); | |
729 | rda_write_string(fd, addr->reply->subject); | |
730 | rda_write_string(fd, addr->reply->headers); | |
731 | rda_write_string(fd, addr->reply->text); | |
732 | rda_write_string(fd, addr->reply->file); | |
733 | rda_write_string(fd, addr->reply->logfile); | |
734 | rda_write_string(fd, addr->reply->oncelog); | |
735 | } | |
736 | } | |
737 | ||
738 | rda_write_string(fd, NULL); /* Marks end of addresses */ | |
739 | } | |
740 | ||
741 | /* OK, this process is now done. Must use _exit() and not exit() !! */ | |
742 | ||
743 | close(fd); | |
744 | _exit(0); | |
745 | } | |
746 | ||
747 | /* Back in the main process: panic if the fork did not succeed. */ | |
748 | ||
749 | if (pid < 0) | |
750 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "fork failed for %s", rname); | |
751 | ||
752 | /* Read the pipe to get the data from the filter/forward. Our copy of the | |
753 | writing end must be closed first, as otherwise read() won't return zero on an | |
754 | empty pipe. Afterwards, close the reading end. */ | |
755 | ||
756 | close(pfd[pipe_write]); | |
757 | ||
758 | /* Read initial data, including yield and contents of *error */ | |
759 | ||
760 | fd = pfd[pipe_read]; | |
761 | if (read(fd, filtertype, sizeof(int)) != sizeof(int) || | |
762 | read(fd, &yield, sizeof(int)) != sizeof(int) || | |
763 | !rda_read_string(fd, error)) goto DISASTER; | |
764 | ||
765 | DEBUG(D_route) | |
766 | debug_printf("rda_interpret: subprocess yield=%d error=%s\n", yield, *error); | |
767 | ||
768 | /* Read the contents of any syntax error blocks if we have a pointer */ | |
769 | ||
770 | if (eblockp != NULL) | |
771 | { | |
772 | uschar *s; | |
773 | error_block *e; | |
774 | error_block **p = eblockp; | |
775 | for (;;) | |
776 | { | |
777 | if (!rda_read_string(fd, &s)) goto DISASTER; | |
778 | if (s == NULL) break; | |
779 | e = store_get(sizeof(error_block)); | |
780 | e->next = NULL; | |
781 | e->text1 = s; | |
782 | if (!rda_read_string(fd, &s)) goto DISASTER; | |
783 | e->text2 = s; | |
784 | *p = e; | |
785 | p = &(e->next); | |
786 | } | |
787 | } | |
788 | ||
789 | /* If this is a system filter, read the identify of any original header lines | |
790 | that were removed, and then read data for any new ones that were added. */ | |
791 | ||
792 | if (system_filtering) | |
793 | { | |
794 | int hn = 0; | |
795 | header_line *h = header_list; | |
796 | ||
797 | for (;;) | |
798 | { | |
799 | int n; | |
800 | if (read(fd, &n, sizeof(int)) != sizeof(int)) goto DISASTER; | |
801 | if (n < 0) break; | |
802 | while (hn < n) | |
803 | { | |
804 | hn++; | |
805 | h = h->next; | |
806 | if (h == NULL) goto DISASTER_NO_HEADER; | |
807 | } | |
808 | h->type = htype_old; | |
809 | } | |
810 | ||
811 | for (;;) | |
812 | { | |
813 | uschar *s; | |
814 | int type; | |
815 | if (!rda_read_string(fd, &s)) goto DISASTER; | |
816 | if (s == NULL) break; | |
817 | if (read(fd, &type, sizeof(type)) != sizeof(type)) goto DISASTER; | |
818 | header_add(type, "%s", s); | |
819 | } | |
820 | } | |
821 | ||
822 | /* Read the values of the $n variables */ | |
823 | ||
824 | if (read(fd, filter_n, sizeof(filter_n)) != sizeof(filter_n)) goto DISASTER; | |
825 | ||
826 | /* If the yield is DELIVERED, NOTDELIVERED, FAIL, or FREEZE there may follow | |
827 | addresses and data to go with them. Keep them in the same order in the | |
828 | generated chain. */ | |
829 | ||
830 | if (yield == FF_DELIVERED || yield == FF_NOTDELIVERED || | |
831 | yield == FF_FAIL || yield == FF_FREEZE) | |
832 | { | |
833 | address_item **nextp = generated; | |
834 | ||
835 | for (;;) | |
836 | { | |
837 | int i, reply_options; | |
838 | address_item *addr; | |
839 | uschar *recipient; | |
840 | uschar *expandn[EXPAND_MAXN + 2]; | |
841 | ||
842 | /* First string is the address; NULL => end of addresses */ | |
843 | ||
844 | if (!rda_read_string(fd, &recipient)) goto DISASTER; | |
845 | if (recipient == NULL) break; | |
846 | ||
847 | /* Hang on the end of the chain */ | |
848 | ||
849 | addr = deliver_make_addr(recipient, FALSE); | |
850 | *nextp = addr; | |
851 | nextp = &(addr->next); | |
852 | ||
853 | /* Next comes the mode and the flags fields */ | |
854 | ||
855 | if (read(fd, &(addr->mode), sizeof(addr->mode)) != sizeof(addr->mode) || | |
856 | read(fd, &(addr->flags), sizeof(addr->flags)) != sizeof(addr->flags) || | |
857 | !rda_read_string(fd, &(addr->p.errors_address))) goto DISASTER; | |
858 | ||
859 | /* Next comes a possible setting for $thisaddress and any numerical | |
860 | variables for pipe expansion, terminated by a NULL string. The maximum | |
861 | number of numericals is EXPAND_MAXN. Note that we put filter_thisaddress | |
862 | into the zeroth item in the vector - this is sorted out inside the pipe | |
863 | transport. */ | |
864 | ||
865 | for (i = 0; i < EXPAND_MAXN + 1; i++) | |
866 | { | |
867 | uschar *temp; | |
868 | if (!rda_read_string(fd, &temp)) goto DISASTER; | |
869 | if (i == 0) filter_thisaddress = temp; /* Just in case */ | |
870 | expandn[i] = temp; | |
871 | if (temp == NULL) break; | |
872 | } | |
873 | ||
874 | if (i > 0) | |
875 | { | |
876 | addr->pipe_expandn = store_get((i+1) * sizeof(uschar **)); | |
877 | addr->pipe_expandn[i] = NULL; | |
878 | while (--i >= 0) addr->pipe_expandn[i] = expandn[i]; | |
879 | } | |
880 | ||
881 | /* Then an int containing reply options; zero => no reply data. */ | |
882 | ||
883 | if (read(fd, &reply_options, sizeof(int)) != sizeof(int)) goto DISASTER; | |
884 | if ((reply_options & REPLY_EXISTS) != 0) | |
885 | { | |
886 | addr->reply = store_get(sizeof(reply_item)); | |
887 | ||
888 | addr->reply->file_expand = (reply_options & REPLY_EXPAND) != 0; | |
889 | addr->reply->return_message = (reply_options & REPLY_RETURN) != 0; | |
890 | ||
891 | if (read(fd,&(addr->reply->expand_forbid),sizeof(int)) != | |
892 | sizeof(int) || | |
893 | read(fd,&(addr->reply->once_repeat),sizeof(time_t)) != | |
894 | sizeof(time_t) || | |
895 | !rda_read_string(fd, &(addr->reply->to)) || | |
896 | !rda_read_string(fd, &(addr->reply->cc)) || | |
897 | !rda_read_string(fd, &(addr->reply->bcc)) || | |
898 | !rda_read_string(fd, &(addr->reply->from)) || | |
899 | !rda_read_string(fd, &(addr->reply->reply_to)) || | |
900 | !rda_read_string(fd, &(addr->reply->subject)) || | |
901 | !rda_read_string(fd, &(addr->reply->headers)) || | |
902 | !rda_read_string(fd, &(addr->reply->text)) || | |
903 | !rda_read_string(fd, &(addr->reply->file)) || | |
904 | !rda_read_string(fd, &(addr->reply->logfile)) || | |
905 | !rda_read_string(fd, &(addr->reply->oncelog))) | |
906 | goto DISASTER; | |
907 | } | |
908 | } | |
909 | } | |
910 | ||
911 | /* All data has been transferred from the sub-process. Reap it, close the | |
912 | reading end of the pipe, and we are done. */ | |
913 | ||
914 | WAIT_EXIT: | |
915 | while ((rc = wait(&status)) != pid) | |
916 | { | |
917 | if (rc < 0 && errno == ECHILD) /* Process has vanished */ | |
918 | { | |
919 | log_write(0, LOG_MAIN, "redirection process %d vanished unexpectedly", pid); | |
920 | goto FINAL_EXIT; | |
921 | } | |
922 | } | |
923 | ||
924 | if (had_disaster) | |
925 | { | |
926 | *error = string_sprintf("internal problem in %s: failure to transfer " | |
927 | "data from subprocess: status=%04x%s%s%s", rname, | |
928 | status, readerror, | |
929 | (*error == NULL)? US"" : US": error=", | |
930 | (*error == NULL)? US"" : *error); | |
931 | log_write(0, LOG_MAIN|LOG_PANIC, "%s", *error); | |
932 | } | |
933 | else if (status != 0) | |
934 | { | |
935 | log_write(0, LOG_MAIN|LOG_PANIC, "internal problem in %s: unexpected status " | |
936 | "%04x from redirect subprocess (but data correctly received)", rname, | |
937 | status); | |
938 | } | |
939 | ||
940 | FINAL_EXIT: | |
941 | close(fd); | |
942 | signal(SIGCHLD, oldsignal); /* restore */ | |
943 | return yield; | |
944 | ||
945 | ||
946 | /* Come here if the data indicates removal of a header that we can't find */ | |
947 | ||
948 | DISASTER_NO_HEADER: | |
949 | readerror = US" readerror=bad header identifier"; | |
950 | had_disaster = TRUE; | |
951 | yield = FF_ERROR; | |
952 | goto WAIT_EXIT; | |
953 | ||
954 | /* Come here is there's a shambles in transferring the data over the pipe. The | |
955 | value of errno should still be set. */ | |
956 | ||
957 | DISASTER: | |
958 | readerror = string_sprintf(" readerror='%s'", strerror(errno)); | |
959 | had_disaster = TRUE; | |
960 | yield = FF_ERROR; | |
961 | goto WAIT_EXIT; | |
962 | } | |
963 | ||
964 | /* End of rda.c */ |