List separator specifiers in router/transport headers_add/remove. Bug 1581
[exim.git] / src / src / transports / pipe.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
5a66c31b 5/* Copyright (c) University of Cambridge 1995 - 2014 */
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6/* See the file NOTICE for conditions of use and distribution. */
7
8
9#include "../exim.h"
10#include "pipe.h"
11
79378e0f 12#ifdef HAVE_SETCLASSRESOURCES
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13#include <login_cap.h>
14#endif
15
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16
17
18/* Options specific to the pipe transport. They must be in alphabetic
19order (note that "_" comes before the lower case letters). Those starting
20with "*" are not settable by the user but are used by the option-reading
21software for alternative value types. Some options are stored in the transport
22instance block so as to be publicly visible; these are flagged with opt_public.
23*/
24
25optionlist pipe_transport_options[] = {
26 { "allow_commands", opt_stringptr,
27 (void *)offsetof(pipe_transport_options_block, allow_commands) },
28 { "batch_id", opt_stringptr | opt_public,
29 (void *)offsetof(transport_instance, batch_id) },
30 { "batch_max", opt_int | opt_public,
31 (void *)offsetof(transport_instance, batch_max) },
32 { "check_string", opt_stringptr,
33 (void *)offsetof(pipe_transport_options_block, check_string) },
34 { "command", opt_stringptr,
35 (void *)offsetof(pipe_transport_options_block, cmd) },
36 { "environment", opt_stringptr,
37 (void *)offsetof(pipe_transport_options_block, environment) },
38 { "escape_string", opt_stringptr,
39 (void *)offsetof(pipe_transport_options_block, escape_string) },
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40 { "force_command", opt_bool,
41 (void *)offsetof(pipe_transport_options_block, force_command) },
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42 { "freeze_exec_fail", opt_bool,
43 (void *)offsetof(pipe_transport_options_block, freeze_exec_fail) },
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44 { "freeze_signal", opt_bool,
45 (void *)offsetof(pipe_transport_options_block, freeze_signal) },
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46 { "ignore_status", opt_bool,
47 (void *)offsetof(pipe_transport_options_block, ignore_status) },
48 { "log_defer_output", opt_bool | opt_public,
49 (void *)offsetof(transport_instance, log_defer_output) },
50 { "log_fail_output", opt_bool | opt_public,
51 (void *)offsetof(transport_instance, log_fail_output) },
52 { "log_output", opt_bool | opt_public,
53 (void *)offsetof(transport_instance, log_output) },
54 { "max_output", opt_mkint,
55 (void *)offsetof(pipe_transport_options_block, max_output) },
56 { "message_prefix", opt_stringptr,
57 (void *)offsetof(pipe_transport_options_block, message_prefix) },
58 { "message_suffix", opt_stringptr,
59 (void *)offsetof(pipe_transport_options_block, message_suffix) },
60 { "path", opt_stringptr,
61 (void *)offsetof(pipe_transport_options_block, path) },
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62 { "permit_coredump", opt_bool,
63 (void *)offsetof(pipe_transport_options_block, permit_coredump) },
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64 { "pipe_as_creator", opt_bool | opt_public,
65 (void *)offsetof(transport_instance, deliver_as_creator) },
66 { "restrict_to_path", opt_bool,
67 (void *)offsetof(pipe_transport_options_block, restrict_to_path) },
68 { "return_fail_output",opt_bool | opt_public,
69 (void *)offsetof(transport_instance, return_fail_output) },
70 { "return_output", opt_bool | opt_public,
71 (void *)offsetof(transport_instance, return_output) },
72 { "temp_errors", opt_stringptr,
73 (void *)offsetof(pipe_transport_options_block, temp_errors) },
74 { "timeout", opt_time,
75 (void *)offsetof(pipe_transport_options_block, timeout) },
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76 { "timeout_defer", opt_bool,
77 (void *)offsetof(pipe_transport_options_block, timeout_defer) },
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78 { "umask", opt_octint,
79 (void *)offsetof(pipe_transport_options_block, umask) },
80 { "use_bsmtp", opt_bool,
81 (void *)offsetof(pipe_transport_options_block, use_bsmtp) },
79378e0f 82 #ifdef HAVE_SETCLASSRESOURCES
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83 { "use_classresources", opt_bool,
84 (void *)offsetof(pipe_transport_options_block, use_classresources) },
85 #endif
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86 { "use_crlf", opt_bool,
87 (void *)offsetof(pipe_transport_options_block, use_crlf) },
88 { "use_shell", opt_bool,
89 (void *)offsetof(pipe_transport_options_block, use_shell) },
90};
91
92/* Size of the options list. An extern variable has to be used so that its
93address can appear in the tables drtables.c. */
94
95int pipe_transport_options_count =
96 sizeof(pipe_transport_options)/sizeof(optionlist);
97
98/* Default private options block for the pipe transport. */
99
100pipe_transport_options_block pipe_transport_option_defaults = {
101 NULL, /* cmd */
102 NULL, /* allow_commands */
103 NULL, /* environment */
cb741023 104 US"/bin:/usr/bin", /* path */
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105 NULL, /* message_prefix (reset in init if not bsmtp) */
106 NULL, /* message_suffix (ditto) */
107 US mac_expanded_string(EX_TEMPFAIL) ":" /* temp_errors */
108 mac_expanded_string(EX_CANTCREAT),
109 NULL, /* check_string */
110 NULL, /* escape_string */
111 022, /* umask */
112 20480, /* max_output */
113 60*60, /* timeout */
114 0, /* options */
09792322 115 FALSE, /* force_command */
0756eb3c 116 FALSE, /* freeze_exec_fail */
2fe76745 117 FALSE, /* freeze_signal */
0756eb3c 118 FALSE, /* ignore_status */
a29e5231 119 FALSE, /* permit_coredump */
0756eb3c 120 FALSE, /* restrict_to_path */
2e2a30b4 121 FALSE, /* timeout_defer */
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122 FALSE, /* use_shell */
123 FALSE, /* use_bsmtp */
929ba01c 124 FALSE, /* use_classresources */
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125 FALSE /* use_crlf */
126};
127
128
129
130/*************************************************
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131* Setup entry point *
132*************************************************/
133
134/* Called for each delivery in the privileged state, just before the uid/gid
135are changed and the main entry point is called. In a system that supports the
136login_cap facilities, this function is used to set the class resource limits
a29e5231 137for the user. It may also re-enable coredumps.
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138
139Arguments:
140 tblock points to the transport instance
141 addrlist addresses about to be delivered (not used)
142 dummy not used (doesn't pass back data)
143 uid the uid that will be set (not used)
144 gid the gid that will be set (not used)
145 errmsg where to put an error message
146
147Returns: OK, FAIL, or DEFER
148*/
149
150static int
151pipe_transport_setup(transport_instance *tblock, address_item *addrlist,
152 transport_feedback *dummy, uid_t uid, gid_t gid, uschar **errmsg)
153{
154pipe_transport_options_block *ob =
155 (pipe_transport_options_block *)(tblock->options_block);
156
157addrlist = addrlist; /* Keep compiler happy */
158dummy = dummy;
159uid = uid;
160gid = gid;
161errmsg = errmsg;
162ob = ob;
163
79378e0f 164#ifdef HAVE_SETCLASSRESOURCES
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165if (ob->use_classresources)
166 {
167 struct passwd *pw = getpwuid(uid);
168 if (pw != NULL)
169 {
170 login_cap_t *lc = login_getpwclass(pw);
171 if (lc != NULL)
172 {
173 setclassresources(lc);
174 login_close(lc);
175 }
176 }
177 }
178#endif
179
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180#ifdef RLIMIT_CORE
181if (ob->permit_coredump)
182 {
183 struct rlimit rl;
184 rl.rlim_cur = RLIM_INFINITY;
185 rl.rlim_max = RLIM_INFINITY;
186 if (setrlimit(RLIMIT_CORE, &rl) < 0)
187 {
188#ifdef SETRLIMIT_NOT_SUPPORTED
189 if (errno != ENOSYS && errno != ENOTSUP)
190#endif
191 log_write(0, LOG_MAIN,
762ca6f3 192 "delivery setrlimit(RLIMIT_CORE, RLIM_INFINITY) failed: %s",
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193 strerror(errno));
194 }
195 }
196#endif
197
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198return OK;
199}
200
201
202
203/*************************************************
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204* Initialization entry point *
205*************************************************/
206
207/* Called for each instance, after its options have been read, to
208enable consistency checks to be done, or anything else that needs
209to be set up. */
210
211void
212pipe_transport_init(transport_instance *tblock)
213{
214pipe_transport_options_block *ob =
215 (pipe_transport_options_block *)(tblock->options_block);
216
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217/* Set up the setup entry point, to be called in the privileged state */
218
219tblock->setup = pipe_transport_setup;
220
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221/* If pipe_as_creator is set, then uid/gid should not be set. */
222
223if (tblock->deliver_as_creator && (tblock->uid_set || tblock->gid_set ||
224 tblock->expand_uid != NULL || tblock->expand_gid != NULL))
225 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
226 "both pipe_as_creator and an explicit uid/gid are set for the %s "
227 "transport", tblock->name);
228
229/* If a fixed uid field is set, then a gid field must also be set. */
230
231if (tblock->uid_set && !tblock->gid_set && tblock->expand_gid == NULL)
232 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
233 "user set without group for the %s transport", tblock->name);
234
235/* Temp_errors must consist only of digits and colons, but there can be
236spaces round the colons, so allow them too. */
237
238if (ob->temp_errors != NULL && Ustrcmp(ob->temp_errors, "*") != 0)
239 {
240 size_t p = Ustrspn(ob->temp_errors, "0123456789: ");
241 if (ob->temp_errors[p] != 0)
242 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
243 "temp_errors must be a list of numbers or an asterisk for the %s "
244 "transport", tblock->name);
245 }
246
247/* Only one of return_output/return_fail_output or log_output/log_fail_output
248should be set. */
249
250if (tblock->return_output && tblock->return_fail_output)
251 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
252 "both return_output and return_fail_output set for %s transport",
253 tblock->name);
254
255if (tblock->log_output && tblock->log_fail_output)
256 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
257 "both log_output and log_fail_output set for the %s transport",
258 tblock->name);
259
260/* If batch SMTP is set, force the check and escape strings, and arrange that
261headers are also escaped. */
262
263if (ob->use_bsmtp)
264 {
265 ob->check_string = US".";
266 ob->escape_string = US"..";
267 ob->options |= topt_escape_headers;
268 }
269
270/* If not batch SMTP, and message_prefix or message_suffix are unset, insert
271default values for them. */
272
273else
274 {
275 if (ob->message_prefix == NULL) ob->message_prefix =
276 US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n";
277 if (ob->message_suffix == NULL) ob->message_suffix = US"\n";
278 }
279
280/* The restrict_to_path and use_shell options are incompatible */
281
282if (ob->restrict_to_path && ob->use_shell)
283 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
284 "both restrict_to_path and use_shell set for %s transport",
285 tblock->name);
286
287/* The allow_commands and use_shell options are incompatible */
288
289if (ob->allow_commands && ob->use_shell)
290 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
291 "both allow_commands and use_shell set for %s transport",
292 tblock->name);
293
294/* Set up the bitwise options for transport_write_message from the various
295driver options. Only one of body_only and headers_only can be set. */
296
297ob->options |=
298 (tblock->body_only? topt_no_headers : 0) |
299 (tblock->headers_only? topt_no_body : 0) |
300 (tblock->return_path_add? topt_add_return_path : 0) |
301 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
302 (tblock->envelope_to_add? topt_add_envelope_to : 0) |
303 (ob->use_crlf? topt_use_crlf : 0);
304}
305
306
307
308/*************************************************
309* Set up direct (non-shell) command *
310*************************************************/
311
312/* This function is called when a command line is to be parsed by the transport
313and executed directly, without the use of /bin/sh.
314
315Arguments:
316 argvptr pointer to anchor for argv vector
317 cmd points to the command string
318 expand_arguments true if expansion is to occur
319 expand_fail error if expansion fails
320 addr chain of addresses
321 tname the transport name
322 ob the transport options block
323
324Returns: TRUE if all went well; otherwise an error will be
325 set in the first address and FALSE returned
326*/
327
328static BOOL
329set_up_direct_command(uschar ***argvptr, uschar *cmd, BOOL expand_arguments,
330 int expand_fail, address_item *addr, uschar *tname,
331 pipe_transport_options_block *ob)
332{
333BOOL permitted = FALSE;
334uschar **argv;
335uschar buffer[64];
336
337/* Set up "transport <name>" to be put in any error messages, and then
338call the common function for creating an argument list and expanding
339the items if necessary. If it fails, this function fails (error information
340is in the addresses). */
341
342sprintf(CS buffer, "%.50s transport", tname);
343if (!transport_set_up_command(argvptr, cmd, expand_arguments, expand_fail,
344 addr, buffer, NULL))
345 return FALSE;
346
347/* Point to the set-up arguments. */
348
349argv = *argvptr;
350
351/* If allow_commands is set, see if the command is in the permitted list. */
352
353if (ob->allow_commands != NULL)
354 {
355 int sep = 0;
356 uschar *s, *p;
357 uschar buffer[256];
358
359 s = expand_string(ob->allow_commands);
360 if (s == NULL)
361 {
362 addr->transport_return = DEFER;
363 addr->message = string_sprintf("failed to expand string \"%s\" "
364 "for %s transport: %s", ob->allow_commands, tname, expand_string_message);
365 return FALSE;
366 }
367
368 while ((p = string_nextinlist(&s, &sep, buffer, sizeof(buffer))) != NULL)
369 {
370 if (Ustrcmp(p, argv[0]) == 0) { permitted = TRUE; break; }
371 }
372 }
373
374/* If permitted is TRUE it means the command was found in the allowed list, and
375no further checks are done. If permitted = FALSE, it either means
376allow_commands wasn't set, or that the command didn't match anything in the
377list. In both cases, if restrict_to_path is set, we fail if the command
378contains any slashes, but if restrict_to_path is not set, we must fail the
379command only if allow_commands is set. */
380
381if (!permitted)
382 {
383 if (ob->restrict_to_path)
384 {
385 if (Ustrchr(argv[0], '/') != NULL)
386 {
387 addr->transport_return = FAIL;
388 addr->message = string_sprintf("\"/\" found in \"%s\" (command for %s "
389 "transport) - failed for security reasons", cmd, tname);
390 return FALSE;
391 }
392 }
393
394 else if (ob->allow_commands != NULL)
395 {
396 addr->transport_return = FAIL;
397 addr->message = string_sprintf("\"%s\" command not permitted by %s "
398 "transport", argv[0], tname);
399 return FALSE;
400 }
401 }
402
403/* If the command is not an absolute path, search the PATH directories
404for it. */
405
406if (argv[0][0] != '/')
407 {
408 int sep = 0;
409 uschar *p;
410 uschar *listptr = ob->path;
411 uschar buffer[1024];
412
413 while ((p = string_nextinlist(&listptr, &sep, buffer, sizeof(buffer))) != NULL)
414 {
415 struct stat statbuf;
416 sprintf(CS big_buffer, "%.256s/%.256s", p, argv[0]);
417 if (Ustat(big_buffer, &statbuf) == 0)
418 {
419 argv[0] = string_copy(big_buffer);
420 break;
421 }
422 }
423 if (p == NULL)
424 {
425 addr->transport_return = FAIL;
426 addr->message = string_sprintf("\"%s\" command not found for %s transport",
427 argv[0], tname);
428 return FALSE;
429 }
430 }
431
432return TRUE;
433}
434
435
436/*************************************************
437* Set up shell command *
438*************************************************/
439
440/* This function is called when a command line is to be passed to /bin/sh
441without parsing inside the transport.
442
443Arguments:
444 argvptr pointer to anchor for argv vector
445 cmd points to the command string
446 expand_arguments true if expansion is to occur
447 expand_fail error if expansion fails
448 addr chain of addresses
449 tname the transport name
450
451Returns: TRUE if all went well; otherwise an error will be
452 set in the first address and FALSE returned
453*/
454
455static BOOL
456set_up_shell_command(uschar ***argvptr, uschar *cmd, BOOL expand_arguments,
457 int expand_fail, address_item *addr, uschar *tname)
458{
459uschar **argv;
460
461*argvptr = argv = store_get((4)*sizeof(uschar *));
462
463argv[0] = US"/bin/sh";
464argv[1] = US"-c";
465
466/* We have to take special action to handle the special "variable" called
467$pipe_addresses, which is not recognized by the normal expansion function. */
468
469DEBUG(D_transport)
470 debug_printf("shell pipe command before expansion:\n %s\n", cmd);
471
472if (expand_arguments)
473 {
474 uschar *s = cmd;
475 uschar *p = Ustrstr(cmd, "pipe_addresses");
476
477 if (p != NULL && (
478 (p > cmd && p[-1] == '$') ||
479 (p > cmd + 1 && p[-2] == '$' && p[-1] == '{' && p[14] == '}')))
480 {
481 address_item *ad;
482 uschar *q = p + 14;
483 int size = Ustrlen(cmd) + 64;
484 int offset;
485
486 if (p[-1] == '{') { q++; p--; }
487
488 s = store_get(size);
489 offset = p - cmd - 1;
490 Ustrncpy(s, cmd, offset);
491
492 for (ad = addr; ad != NULL; ad = ad->next)
493 {
494 if (ad != addr) string_cat(s, &size, &offset, US" ", 1);
495 string_cat(s, &size, &offset, ad->address, Ustrlen(ad->address));
496 }
497
498 string_cat(s, &size, &offset, q, Ustrlen(q));
499 s[offset] = 0;
500 }
501
502 /* Allow $recipients in the expansion iff it comes from a system filter */
503
504 enable_dollar_recipients = addr != NULL &&
505 addr->parent != NULL &&
506 Ustrcmp(addr->parent->address, "system-filter") == 0;
507 argv[2] = expand_string(s);
508 enable_dollar_recipients = FALSE;
509
510 if (argv[2] == NULL)
511 {
512 addr->transport_return = search_find_defer? DEFER : expand_fail;
513 addr->message = string_sprintf("Expansion of command \"%s\" "
514 "in %s transport failed: %s",
515 cmd, tname, expand_string_message);
516 return FALSE;
517 }
518
519 DEBUG(D_transport)
520 debug_printf("shell pipe command after expansion:\n %s\n", argv[2]);
521 }
522else argv[2] = cmd;
523
524argv[3] = (uschar *)0;
525return TRUE;
526}
527
528
529
530
531/*************************************************
532* Main entry point *
533*************************************************/
534
535/* See local README for interface details. This transport always returns FALSE,
536indicating that the status in the first address is the status for all addresses
537in a batch. */
538
539BOOL
540pipe_transport_entry(
541 transport_instance *tblock, /* data for this instantiation */
542 address_item *addr) /* address(es) we are working on */
543{
544pid_t pid, outpid;
545int fd_in, fd_out, rc;
546int envcount = 0;
547int envsep = 0;
548int expand_fail;
549pipe_transport_options_block *ob =
550 (pipe_transport_options_block *)(tblock->options_block);
551int timeout = ob->timeout;
552BOOL written_ok = FALSE;
553BOOL expand_arguments;
554uschar **argv;
555uschar *envp[50];
556uschar *envlist = ob->environment;
557uschar *cmd, *ss;
558uschar *eol = (ob->use_crlf)? US"\r\n" : US"\n";
559
560DEBUG(D_transport) debug_printf("%s transport entered\n", tblock->name);
561
562/* Set up for the good case */
563
564addr->transport_return = OK;
565addr->basic_errno = 0;
566
567/* Pipes are not accepted as general addresses, but they can be generated from
568.forward files or alias files. In those cases, the pfr flag is set, and the
569command to be obeyed is pointed to by addr->local_part; it starts with the pipe
570symbol. In other cases, the command is supplied as one of the pipe transport's
571options. */
572
573if (testflag(addr, af_pfr) && addr->local_part[0] == '|')
574 {
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575 if (ob->force_command)
576 {
577 /* Enables expansion of $address_pipe into seperate arguments */
578 setflag(addr, af_force_command);
579 cmd = ob->cmd;
580 expand_arguments = TRUE;
581 expand_fail = PANIC;
582 }
583 else
584 {
585 cmd = addr->local_part + 1;
586 while (isspace(*cmd)) cmd++;
587 expand_arguments = testflag(addr, af_expand_pipe);
588 expand_fail = FAIL;
09792322 589 }
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590 }
591else
592 {
593 cmd = ob->cmd;
594 expand_arguments = TRUE;
595 expand_fail = PANIC;
596 }
597
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598/* If no command has been supplied, we are in trouble.
599 * We also check for an empty string since it may be
600 * coming from addr->local_part[0] == '|'
601 */
0756eb3c 602
09792322 603if (cmd == NULL || *cmd == '\0')
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604 {
605 addr->transport_return = DEFER;
606 addr->message = string_sprintf("no command specified for %s transport",
607 tblock->name);
608 return FALSE;
609 }
610
611/* When a pipe is set up by a filter file, there may be values for $thisaddress
612and numerical the variables in existence. These are passed in
613addr->pipe_expandn for use here. */
614
615if (expand_arguments && addr->pipe_expandn != NULL)
616 {
617 uschar **ss = addr->pipe_expandn;
618 expand_nmax = -1;
619 if (*ss != NULL) filter_thisaddress = *ss++;
620 while (*ss != NULL)
621 {
622 expand_nstring[++expand_nmax] = *ss;
623 expand_nlength[expand_nmax] = Ustrlen(*ss++);
624 }
625 }
626
627/* The default way of processing the command is to split it up into arguments
628here, and run it directly. This offers some security advantages. However, there
629are installations that want by default to run commands under /bin/sh always, so
630there is an option to do that. */
631
632if (ob->use_shell)
633 {
634 if (!set_up_shell_command(&argv, cmd, expand_arguments, expand_fail, addr,
635 tblock->name)) return FALSE;
636 }
637else if (!set_up_direct_command(&argv, cmd, expand_arguments, expand_fail, addr,
638 tblock->name, ob)) return FALSE;
639
640expand_nmax = -1; /* Reset */
641filter_thisaddress = NULL;
642
643/* Set up the environment for the command. */
644
645envp[envcount++] = string_sprintf("LOCAL_PART=%s", deliver_localpart);
646envp[envcount++] = string_sprintf("LOGNAME=%s", deliver_localpart);
647envp[envcount++] = string_sprintf("USER=%s", deliver_localpart);
648envp[envcount++] = string_sprintf("LOCAL_PART_PREFIX=%#s",
649 deliver_localpart_prefix);
650envp[envcount++] = string_sprintf("LOCAL_PART_SUFFIX=%#s",
651 deliver_localpart_suffix);
652envp[envcount++] = string_sprintf("DOMAIN=%s", deliver_domain);
653envp[envcount++] = string_sprintf("HOME=%#s", deliver_home);
654envp[envcount++] = string_sprintf("MESSAGE_ID=%s", message_id);
655envp[envcount++] = string_sprintf("PATH=%s", ob->path);
656envp[envcount++] = string_sprintf("RECIPIENT=%#s%#s%#s@%#s",
657 deliver_localpart_prefix, deliver_localpart, deliver_localpart_suffix,
658 deliver_domain);
659envp[envcount++] = string_sprintf("QUALIFY_DOMAIN=%s", qualify_domain_sender);
660envp[envcount++] = string_sprintf("SENDER=%s", sender_address);
661envp[envcount++] = US"SHELL=/bin/sh";
662
663if (addr->host_list != NULL)
664 envp[envcount++] = string_sprintf("HOST=%s", addr->host_list->name);
665
666if (timestamps_utc) envp[envcount++] = US"TZ=UTC";
667else if (timezone_string != NULL && timezone_string[0] != 0)
668 envp[envcount++] = string_sprintf("TZ=%s", timezone_string);
669
670/* Add any requested items */
671
672if (envlist != NULL)
673 {
674 envlist = expand_string(envlist);
675 if (envlist == NULL)
676 {
677 addr->transport_return = DEFER;
678 addr->message = string_sprintf("failed to expand string \"%s\" "
679 "for %s transport: %s", ob->environment, tblock->name,
680 expand_string_message);
681 return FALSE;
682 }
683 }
684
685while ((ss = string_nextinlist(&envlist, &envsep, big_buffer, big_buffer_size))
686 != NULL)
687 {
688 if (envcount > sizeof(envp)/sizeof(uschar *) - 2)
689 {
690 addr->transport_return = DEFER;
691 addr->message = string_sprintf("too many environment settings for "
692 "%s transport", tblock->name);
693 return FALSE;
694 }
695 envp[envcount++] = string_copy(ss);
696 }
697
698envp[envcount] = NULL;
699
700/* If the -N option is set, can't do any more. */
701
702if (dont_deliver)
703 {
704 DEBUG(D_transport)
705 debug_printf("*** delivery by %s transport bypassed by -N option",
706 tblock->name);
707 return FALSE;
708 }
709
710
711/* Handling the output from the pipe is tricky. If a file for catching this
712output is provided, we could in theory just hand that fd over to the process,
713but this isn't very safe because it might loop and carry on writing for
714ever (which is exactly what happened in early versions of Exim). Therefore we
715use the standard child_open() function, which creates pipes. We can then read
716our end of the output pipe and count the number of bytes that come through,
717chopping the sub-process if it exceeds some limit.
718
719However, this means we want to run a sub-process with both its input and output
720attached to pipes. We can't handle that easily from a single parent process
721using straightforward code such as the transport_write_message() function
722because the subprocess might not be reading its input because it is trying to
723write to a full output pipe. The complication of redesigning the world to
724handle this is too great - simpler just to run another process to do the
725reading of the output pipe. */
726
727
728/* As this is a local transport, we are already running with the required
729uid/gid and current directory. Request that the new process be a process group
730leader, so we can kill it and all its children on a timeout. */
731
732if ((pid = child_open(argv, envp, ob->umask, &fd_in, &fd_out, TRUE)) < 0)
733 {
734 addr->transport_return = DEFER;
735 addr->message = string_sprintf(
736 "Failed to create child process for %s transport: %s", tblock->name,
737 strerror(errno));
738 return FALSE;
739 }
740
741/* Now fork a process to handle the output that comes down the pipe. */
742
743if ((outpid = fork()) < 0)
744 {
745 addr->basic_errno = errno;
746 addr->transport_return = DEFER;
747 addr->message = string_sprintf(
748 "Failed to create process for handling output in %s transport",
749 tblock->name);
f1e894f3
PH
750 (void)close(fd_in);
751 (void)close(fd_out);
0756eb3c
PH
752 return FALSE;
753 }
754
755/* This is the code for the output-handling subprocess. Read from the pipe
756in chunks, and write to the return file if one is provided. Keep track of
757the number of bytes handled. If the limit is exceeded, try to kill the
758subprocess group, and in any case close the pipe and exit, which should cause
759the subprocess to fail. */
760
761if (outpid == 0)
762 {
763 int count = 0;
f1e894f3 764 (void)close(fd_in);
0756eb3c
PH
765 set_process_info("reading output from |%s", cmd);
766 while ((rc = read(fd_out, big_buffer, big_buffer_size)) > 0)
767 {
768 if (addr->return_file >= 0)
1ac6b2e7
JH
769 if(write(addr->return_file, big_buffer, rc) != rc)
770 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
0756eb3c
PH
771 count += rc;
772 if (count > ob->max_output)
773 {
0756eb3c
PH
774 DEBUG(D_transport) debug_printf("Too much output from pipe - killed\n");
775 if (addr->return_file >= 0)
1ac6b2e7
JH
776 {
777 uschar *message = US"\n\n*** Too much output - remainder discarded ***\n";
778 rc = Ustrlen(message);
779 if(write(addr->return_file, message, rc) != rc)
780 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
781 }
0756eb3c
PH
782 killpg(pid, SIGKILL);
783 break;
784 }
785 }
f1e894f3 786 (void)close(fd_out);
0756eb3c
PH
787 _exit(0);
788 }
789
f1e894f3 790(void)close(fd_out); /* Not used in this process */
0756eb3c
PH
791
792
793/* Carrying on now with the main parent process. Attempt to write the message
794to it down the pipe. It is a fallacy to think that you can detect write errors
795when the sub-process fails to read the pipe. The parent process may complete
796writing and close the pipe before the sub-process completes. We could sleep a
797bit here to let the sub-process get going, but it may still not complete. So we
798ignore all writing errors. (When in the test harness, we do do a short sleep so
799any debugging output is likely to be in the same order.) */
800
801if (running_in_test_harness) millisleep(500);
802
803DEBUG(D_transport) debug_printf("Writing message to pipe\n");
804
805/* Arrange to time out writes if there is a timeout set. */
806
807if (timeout > 0)
808 {
809 sigalrm_seen = FALSE;
810 transport_write_timeout = timeout;
811 }
812
813/* Reset the counter of bytes written */
814
815transport_count = 0;
816
817/* First write any configured prefix information */
818
819if (ob->message_prefix != NULL)
820 {
821 uschar *prefix = expand_string(ob->message_prefix);
822 if (prefix == NULL)
823 {
824 addr->transport_return = search_find_defer? DEFER : PANIC;
825 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
826 "transport) failed: %s", ob->message_prefix, tblock->name,
827 expand_string_message);
828 return FALSE;
829 }
830 if (!transport_write_block(fd_in, prefix, Ustrlen(prefix)))
831 goto END_WRITE;
832 }
833
834/* If the use_bsmtp option is set, we need to write SMTP prefix information.
835The various different values for batching are handled outside; if there is more
836than one address available here, all must be included. Force SMTP dot-handling.
837*/
838
839if (ob->use_bsmtp)
840 {
841 address_item *a;
842
843 if (!transport_write_string(fd_in, "MAIL FROM:<%s>%s", return_path, eol))
844 goto END_WRITE;
845
846 for (a = addr; a != NULL; a = a->next)
847 {
848 if (!transport_write_string(fd_in,
849 "RCPT TO:<%s>%s",
850 transport_rcpt_address(a, tblock->rcpt_include_affixes),
851 eol))
852 goto END_WRITE;
853 }
854
855 if (!transport_write_string(fd_in, "DATA%s", eol)) goto END_WRITE;
856 }
857
858/* Now the actual message - the options were set at initialization time */
859
860if (!transport_write_message(addr, fd_in, ob->options, 0, tblock->add_headers,
861 tblock->remove_headers, ob->check_string, ob->escape_string,
862 tblock->rewrite_rules, tblock->rewrite_existflags))
863 goto END_WRITE;
864
865/* Now any configured suffix */
866
867if (ob->message_suffix != NULL)
868 {
869 uschar *suffix = expand_string(ob->message_suffix);
870 if (suffix == NULL)
871 {
872 addr->transport_return = search_find_defer? DEFER : PANIC;
873 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
874 "transport) failed: %s", ob->message_suffix, tblock->name,
875 expand_string_message);
876 return FALSE;
877 }
878 if (!transport_write_block(fd_in, suffix, Ustrlen(suffix)))
879 goto END_WRITE;
880 }
881
882/* If local_smtp, write the terminating dot. */
883
884if (ob->use_bsmtp && !transport_write_string(fd_in, ".%s", eol))
885 goto END_WRITE;
886
887/* Flag all writing completed successfully. */
888
889written_ok = TRUE;
890
891/* Come here if there are errors during writing. */
892
893END_WRITE:
894
895/* OK, the writing is now all done. Close the pipe. */
896
897(void) close(fd_in);
898
899/* Handle errors during writing. For timeouts, set the timeout for waiting for
900the child process to 1 second. If the process at the far end of the pipe died
901without reading all of it, we expect an EPIPE error, which should be ignored.
902We used also to ignore WRITEINCOMPLETE but the writing function is now cleverer
903at handling OS where the death of a pipe doesn't give EPIPE immediately. See
2e2a30b4 904comments therein. */
0756eb3c
PH
905
906if (!written_ok)
907 {
908 if (errno == ETIMEDOUT)
2e2a30b4
PH
909 {
910 addr->message = string_sprintf("%stimeout while writing to pipe",
911 transport_filter_timed_out? "transport filter " : "");
912 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
0756eb3c 913 timeout = 1;
2e2a30b4
PH
914 }
915 else if (errno == EPIPE)
0756eb3c 916 {
2e2a30b4 917 debug_printf("transport error EPIPE ignored\n");
0756eb3c
PH
918 }
919 else
920 {
8e669ac1 921 addr->transport_return = PANIC;
0756eb3c
PH
922 addr->basic_errno = errno;
923 if (errno == ERRNO_CHHEADER_FAIL)
924 addr->message =
925 string_sprintf("Failed to expand headers_add or headers_remove: %s",
926 expand_string_message);
927 else if (errno == ERRNO_FILTER_FAIL)
35af9f61
PH
928 addr->message = string_sprintf("Transport filter process failed (%d)%s",
929 addr->more_errno,
930 (addr->more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
0756eb3c
PH
931 else if (errno == ERRNO_WRITEINCOMPLETE)
932 addr->message = string_sprintf("Failed repeatedly to write data");
933 else
934 addr->message = string_sprintf("Error %d", errno);
935 return FALSE;
936 }
937 }
938
939/* Wait for the child process to complete and take action if the returned
940status is nonzero. The timeout will be just 1 second if any of the writes
941above timed out. */
942
943if ((rc = child_close(pid, timeout)) != 0)
944 {
22c3b60b
PH
945 uschar *tmsg = (addr->message == NULL)? US"" :
946 string_sprintf(" (preceded by %s)", addr->message);
947
0756eb3c
PH
948 /* The process did not complete in time; kill its process group and fail
949 the delivery. It appears to be necessary to kill the output process too, as
950 otherwise it hangs on for some time if the actual pipe process is sleeping.
951 (At least, that's what I observed on Solaris 2.5.1.) Since we are failing
952 the delivery, that shouldn't cause any problem. */
953
954 if (rc == -256)
955 {
956 killpg(pid, SIGKILL);
957 kill(outpid, SIGKILL);
2e2a30b4 958 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
22c3b60b 959 addr->message = string_sprintf("pipe delivery process timed out%s", tmsg);
0756eb3c
PH
960 }
961
962 /* Wait() failed. */
963
964 else if (rc == -257)
965 {
966 addr->transport_return = PANIC;
967 addr->message = string_sprintf("Wait() failed for child process of %s "
22c3b60b 968 "transport: %s%s", tblock->name, strerror(errno), tmsg);
0756eb3c
PH
969 }
970
52383f8f
NM
971 /* Since the transport_filter timed out we assume it has sent the child process
972 a malformed or incomplete data stream. Kill off the child process
973 and prevent checking its exit status as it will has probably exited in error.
974 This prevents the transport_filter timeout message from getting overwritten
975 by the exit error which is not the cause of the problem. */
976
977 else if (transport_filter_timed_out)
978 {
979 killpg(pid, SIGKILL);
980 kill(outpid, SIGKILL);
981 }
982
0756eb3c
PH
983 /* Either the process completed, but yielded a non-zero (necessarily
984 positive) status, or the process was terminated by a signal (rc will contain
985 the negation of the signal number). Treat killing by signal as failure unless
2fe76745
PP
986 status is being ignored. By default, the message is bounced back, unless
987 freeze_signal is set, in which case it is frozen instead. */
0756eb3c
PH
988
989 else if (rc < 0)
990 {
2fe76745
PP
991 if (ob->freeze_signal)
992 {
993 addr->transport_return = DEFER;
994 addr->special_action = SPECIAL_FREEZE;
995 addr->message = string_sprintf("Child process of %s transport (running "
996 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
997 -rc, os_strsignal(-rc), tmsg);
998 }
999 else if (!ob->ignore_status)
0756eb3c
PH
1000 {
1001 addr->transport_return = FAIL;
1002 addr->message = string_sprintf("Child process of %s transport (running "
22c3b60b
PH
1003 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
1004 -rc, os_strsignal(-rc), tmsg);
0756eb3c
PH
1005 }
1006 }
1007
1008 /* For positive values (process terminated with non-zero status), we need a
1009 status code to request deferral. A number of systems contain the following
1010 line in sysexits.h:
1011
1012 #define EX_TEMPFAIL 75
1013
1014 with the description
1015
1016 EX_TEMPFAIL -- temporary failure, indicating something that
1017 is not really an error. In sendmail, this means
1018 that a mailer (e.g.) could not create a connection,
1019 and the request should be reattempted later.
1020
1021 Based on this, we use exit code EX_TEMPFAIL as a default to mean "defer" when
1022 not ignoring the returned status. However, there is now an option that
1023 contains a list of temporary codes, with TEMPFAIL and CANTCREAT as defaults.
1024
1025 Another case that needs special treatment is if execve() failed (typically
1026 the command that was given is a non-existent path). By default this is
1027 treated as just another failure, but if freeze_exec_fail is set, the reaction
1028 is to freeze the message rather than bounce the address. Exim used to signal
1029 this failure with EX_UNAVAILABLE, which is definined in many systems as
1030
1031 #define EX_UNAVAILABLE 69
1032
1033 with the description
1034
1035 EX_UNAVAILABLE -- A service is unavailable. This can occur
1036 if a support program or file does not exist. This
1037 can also be used as a catchall message when something
1038 you wanted to do doesn't work, but you don't know why.
1039
1040 However, this can be confused with a command that actually returns 69 because
1041 something *it* wanted is unavailable. At release 4.21, Exim was changed to
1042 use return code 127 instead, because this is what the shell returns when it
1043 is unable to exec a command. We define it as EX_EXECFAILED, and use it in
1044 child.c to signal execve() failure and other unexpected failures such as
1045 setuid() not working - though that won't be the case here because we aren't
1046 changing uid. */
1047
1048 else
1049 {
1050 /* Always handle execve() failure specially if requested to */
1051
1052 if (ob->freeze_exec_fail && (rc == EX_EXECFAILED))
1053 {
1054 addr->transport_return = DEFER;
1055 addr->special_action = SPECIAL_FREEZE;
22c3b60b
PH
1056 addr->message = string_sprintf("pipe process failed to exec \"%s\"%s",
1057 cmd, tmsg);
0756eb3c
PH
1058 }
1059
1060 /* Otherwise take action only if not ignoring status */
1061
1062 else if (!ob->ignore_status)
1063 {
1064 uschar *ss;
1065 int size, ptr, i;
1066
1067 /* If temp_errors is "*" all codes are temporary. Initializion checks
1068 that it's either "*" or a list of numbers. If not "*", scan the list of
1069 temporary failure codes; if any match, the result is DEFER. */
1070
1071 if (ob->temp_errors[0] == '*')
1072 addr->transport_return = DEFER;
1073
1074 else
1075 {
1076 uschar *s = ob->temp_errors;
1077 uschar *p;
1078 uschar buffer[64];
1079 int sep = 0;
1080
1081 addr->transport_return = FAIL;
1082 while ((p = string_nextinlist(&s,&sep,buffer,sizeof(buffer))) != NULL)
1083 {
1084 if (rc == Uatoi(p)) { addr->transport_return = DEFER; break; }
1085 }
1086 }
1087
1088 /* Ensure the message contains the expanded command and arguments. This
1089 doesn't have to be brilliantly efficient - it is an error situation. */
1090
1091 addr->message = string_sprintf("Child process of %s transport returned "
1092 "%d", tblock->name, rc);
1093
1094 ptr = Ustrlen(addr->message);
1095 size = ptr + 1;
1096
1097 /* If the return code is > 128, it often means that a shell command
1098 was terminated by a signal. */
1099
1100 ss = (rc > 128)?
1101 string_sprintf("(could mean shell command ended by signal %d (%s))",
1102 rc-128, os_strsignal(rc-128)) :
1103 US os_strexit(rc);
1104
1105 if (*ss != 0)
1106 {
1107 addr->message = string_cat(addr->message, &size, &ptr, US" ", 1);
1108 addr->message = string_cat(addr->message, &size, &ptr,
1109 ss, Ustrlen(ss));
1110 }
1111
1112 /* Now add the command and arguments */
1113
1114 addr->message = string_cat(addr->message, &size, &ptr,
1115 US" from command:", 14);
1116
1117 for (i = 0; i < sizeof(argv)/sizeof(int *) && argv[i] != NULL; i++)
1118 {
1119 BOOL quote = FALSE;
1120 addr->message = string_cat(addr->message, &size, &ptr, US" ", 1);
1121 if (Ustrpbrk(argv[i], " \t") != NULL)
1122 {
1123 quote = TRUE;
1124 addr->message = string_cat(addr->message, &size, &ptr, US"\"", 1);
1125 }
1126 addr->message = string_cat(addr->message, &size, &ptr, argv[i],
1127 Ustrlen(argv[i]));
1128 if (quote)
1129 addr->message = string_cat(addr->message, &size, &ptr, US"\"", 1);
1130 }
22c3b60b
PH
1131
1132 /* Add previous filter timeout message, if present. */
1133
1134 if (*tmsg != 0)
1135 addr->message = string_cat(addr->message, &size, &ptr, tmsg,
1136 Ustrlen(tmsg));
1137
0756eb3c
PH
1138 addr->message[ptr] = 0; /* Ensure concatenated string terminated */
1139 }
1140 }
1141 }
1142
1143/* Ensure all subprocesses (in particular, the output handling process)
1144are complete before we pass this point. */
1145
1146while (wait(&rc) >= 0);
1147
1148DEBUG(D_transport) debug_printf("%s transport yielded %d\n", tblock->name,
1149 addr->transport_return);
1150
1151/* If there has been a problem, the message in addr->message contains details
1152of the pipe command. We don't want to expose these to the world, so we set up
1153something bland to return to the sender. */
1154
1155if (addr->transport_return != OK)
1156 addr->user_message = US"local delivery failed";
1157
1158return FALSE;
1159}
1160
1161/* End of transport/pipe.c */