1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim maintainers 2020 - 2022 */
6 /* Copyright (c) University of Cambridge 1995 - 2018 */
7 /* See the file NOTICE for conditions of use and distribution. */
8 /* SPDX-License-Identifier: GPL-2.0-or-later */
14 #ifdef HAVE_SETCLASSRESOURCES
15 #include <login_cap.h>
20 /* Options specific to the pipe transport. They must be in alphabetic
21 order (note that "_" comes before the lower case letters). Those starting
22 with "*" are not settable by the user but are used by the option-reading
23 software for alternative value types. Some options are stored in the transport
24 instance block so as to be publicly visible; these are flagged with opt_public.
26 #define LOFF(field) OPT_OFF(pipe_transport_options_block, field)
28 optionlist pipe_transport_options[] = {
29 { "allow_commands", opt_stringptr, LOFF(allow_commands) },
30 { "batch_id", opt_stringptr | opt_public,
31 OPT_OFF(transport_instance, batch_id) },
32 { "batch_max", opt_int | opt_public,
33 OPT_OFF(transport_instance, batch_max) },
34 { "check_string", opt_stringptr, LOFF(check_string) },
35 { "command", opt_stringptr, LOFF(cmd) },
36 { "environment", opt_stringptr, LOFF(environment) },
37 { "escape_string", opt_stringptr, LOFF(escape_string) },
38 { "force_command", opt_bool, LOFF(force_command) },
39 { "freeze_exec_fail", opt_bool, LOFF(freeze_exec_fail) },
40 { "freeze_signal", opt_bool, LOFF(freeze_signal) },
41 { "ignore_status", opt_bool, LOFF(ignore_status) },
42 { "log_defer_output", opt_bool | opt_public,
43 OPT_OFF(transport_instance, log_defer_output) },
44 { "log_fail_output", opt_bool | opt_public,
45 OPT_OFF(transport_instance, log_fail_output) },
46 { "log_output", opt_bool | opt_public,
47 OPT_OFF(transport_instance, log_output) },
48 { "max_output", opt_mkint, LOFF(max_output) },
49 { "message_prefix", opt_stringptr, LOFF(message_prefix) },
50 { "message_suffix", opt_stringptr, LOFF(message_suffix) },
51 { "path", opt_stringptr, LOFF(path) },
52 { "permit_coredump", opt_bool, LOFF(permit_coredump) },
53 { "pipe_as_creator", opt_bool | opt_public,
54 OPT_OFF(transport_instance, deliver_as_creator) },
55 { "restrict_to_path", opt_bool, LOFF(restrict_to_path) },
56 { "return_fail_output",opt_bool | opt_public,
57 OPT_OFF(transport_instance, return_fail_output) },
58 { "return_output", opt_bool | opt_public,
59 OPT_OFF(transport_instance, return_output) },
60 { "temp_errors", opt_stringptr, LOFF(temp_errors) },
61 { "timeout", opt_time, LOFF(timeout) },
62 { "timeout_defer", opt_bool, LOFF(timeout_defer) },
63 { "umask", opt_octint, LOFF(umask) },
64 { "use_bsmtp", opt_bool, LOFF(use_bsmtp) },
65 #ifdef HAVE_SETCLASSRESOURCES
66 { "use_classresources", opt_bool, LOFF(use_classresources) },
68 { "use_crlf", opt_bool, LOFF(use_crlf) },
69 { "use_shell", opt_bool, LOFF(use_shell) },
72 /* Size of the options list. An extern variable has to be used so that its
73 address can appear in the tables drtables.c. */
75 int pipe_transport_options_count =
76 sizeof(pipe_transport_options)/sizeof(optionlist);
82 pipe_transport_options_block pipe_transport_option_defaults = {0};
83 void pipe_transport_init(transport_instance *tblock) {}
84 BOOL pipe_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
86 #else /*!MACRO_PREDEF*/
89 /* Default private options block for the pipe transport. */
91 pipe_transport_options_block pipe_transport_option_defaults = {
92 .path = US"/bin:/usr/bin",
93 .temp_errors = US mac_expanded_string(EX_TEMPFAIL) ":"
94 mac_expanded_string(EX_CANTCREAT),
98 /* all others null/zero/false */
103 /*************************************************
104 * Setup entry point *
105 *************************************************/
107 /* Called for each delivery in the privileged state, just before the uid/gid
108 are changed and the main entry point is called. In a system that supports the
109 login_cap facilities, this function is used to set the class resource limits
110 for the user. It may also re-enable coredumps.
113 tblock points to the transport instance
114 addrlist addresses about to be delivered (not used)
115 dummy not used (doesn't pass back data)
116 uid the uid that will be set (not used)
117 gid the gid that will be set (not used)
118 errmsg where to put an error message
120 Returns: OK, FAIL, or DEFER
124 pipe_transport_setup(transport_instance *tblock, address_item *addrlist,
125 transport_feedback *dummy, uid_t uid, gid_t gid, uschar **errmsg)
127 pipe_transport_options_block *ob =
128 (pipe_transport_options_block *)(tblock->options_block);
130 #ifdef HAVE_SETCLASSRESOURCES
131 if (ob->use_classresources)
133 struct passwd *pw = getpwuid(uid);
136 login_cap_t *lc = login_getpwclass(pw);
139 setclassresources(lc);
147 if (ob->permit_coredump)
150 rl.rlim_cur = RLIM_INFINITY;
151 rl.rlim_max = RLIM_INFINITY;
152 if (setrlimit(RLIMIT_CORE, &rl) < 0)
154 #ifdef SETRLIMIT_NOT_SUPPORTED
155 if (errno != ENOSYS && errno != ENOTSUP)
157 log_write(0, LOG_MAIN,
158 "delivery setrlimit(RLIMIT_CORE, RLIM_INFINITY) failed: %s",
169 /*************************************************
170 * Initialization entry point *
171 *************************************************/
173 /* Called for each instance, after its options have been read, to
174 enable consistency checks to be done, or anything else that needs
178 pipe_transport_init(transport_instance *tblock)
180 pipe_transport_options_block *ob =
181 (pipe_transport_options_block *)(tblock->options_block);
183 /* Set up the setup entry point, to be called in the privileged state */
185 tblock->setup = pipe_transport_setup;
187 /* If pipe_as_creator is set, then uid/gid should not be set. */
189 if (tblock->deliver_as_creator && (tblock->uid_set || tblock->gid_set ||
190 tblock->expand_uid != NULL || tblock->expand_gid != NULL))
191 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
192 "both pipe_as_creator and an explicit uid/gid are set for the %s "
193 "transport", tblock->name);
195 /* If a fixed uid field is set, then a gid field must also be set. */
197 if (tblock->uid_set && !tblock->gid_set && tblock->expand_gid == NULL)
198 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
199 "user set without group for the %s transport", tblock->name);
201 /* Temp_errors must consist only of digits and colons, but there can be
202 spaces round the colons, so allow them too. */
204 if (ob->temp_errors != NULL && Ustrcmp(ob->temp_errors, "*") != 0)
206 size_t p = Ustrspn(ob->temp_errors, "0123456789: ");
207 if (ob->temp_errors[p] != 0)
208 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
209 "temp_errors must be a list of numbers or an asterisk for the %s "
210 "transport", tblock->name);
213 /* Only one of return_output/return_fail_output or log_output/log_fail_output
216 if (tblock->return_output && tblock->return_fail_output)
217 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
218 "both return_output and return_fail_output set for %s transport",
221 if (tblock->log_output && tblock->log_fail_output)
222 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
223 "both log_output and log_fail_output set for the %s transport",
226 /* If batch SMTP is set, force the check and escape strings, and arrange that
227 headers are also escaped. */
231 ob->check_string = US".";
232 ob->escape_string = US"..";
233 ob->options |= topt_escape_headers;
236 /* If not batch SMTP, and message_prefix or message_suffix are unset, insert
237 default values for them. */
241 if (ob->message_prefix == NULL) ob->message_prefix =
242 US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n";
243 if (ob->message_suffix == NULL) ob->message_suffix = US"\n";
246 /* The restrict_to_path and use_shell options are incompatible */
248 if (ob->restrict_to_path && ob->use_shell)
249 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
250 "both restrict_to_path and use_shell set for %s transport",
253 /* The allow_commands and use_shell options are incompatible */
255 if (ob->allow_commands && ob->use_shell)
256 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
257 "both allow_commands and use_shell set for %s transport",
260 /* Set up the bitwise options for transport_write_message from the various
261 driver options. Only one of body_only and headers_only can be set. */
264 (tblock->body_only ? topt_no_headers : 0)
265 | (tblock->headers_only ? topt_no_body : 0)
266 | (tblock->return_path_add ? topt_add_return_path : 0)
267 | (tblock->delivery_date_add ? topt_add_delivery_date : 0)
268 | (tblock->envelope_to_add ? topt_add_envelope_to : 0)
269 | (ob->use_crlf ? topt_use_crlf : 0);
274 /*************************************************
275 * Set up direct (non-shell) command *
276 *************************************************/
278 /* This function is called when a command line is to be parsed by the transport
279 and executed directly, without the use of /bin/sh.
282 argvptr pointer to anchor for argv vector
283 cmd points to the command string
284 expand_arguments true if expansion is to occur
285 expand_fail error if expansion fails
286 addr chain of addresses
287 tname the transport name
288 ob the transport options block
290 Returns: TRUE if all went well; otherwise an error will be
291 set in the first address and FALSE returned
295 set_up_direct_command(const uschar *** argvptr, uschar * cmd,
296 BOOL expand_arguments, int expand_fail, address_item * addr, uschar * tname,
297 pipe_transport_options_block * ob)
299 BOOL permitted = FALSE;
302 /* Set up "transport <name>" to be put in any error messages, and then
303 call the common function for creating an argument list and expanding
304 the items if necessary. If it fails, this function fails (error information
305 is in the addresses). */
307 if (!transport_set_up_command(argvptr, cmd,
308 expand_arguments ? TSUC_EXPAND_ARGS : 0,
309 expand_fail, addr, string_sprintf("%.50s transport", tname), NULL))
312 /* Point to the set-up arguments. */
316 /* If allow_commands is set, see if the command is in the permitted list. */
318 if (ob->allow_commands)
324 if (!(s = expand_string(ob->allow_commands)))
326 addr->transport_return = DEFER;
327 addr->message = string_sprintf("failed to expand string \"%s\" "
328 "for %s transport: %s", ob->allow_commands, tname, expand_string_message);
332 while ((p = string_nextinlist(&s, &sep, NULL, 0)))
333 if (Ustrcmp(p, argv[0]) == 0) { permitted = TRUE; break; }
336 /* If permitted is TRUE it means the command was found in the allowed list, and
337 no further checks are done. If permitted = FALSE, it either means
338 allow_commands wasn't set, or that the command didn't match anything in the
339 list. In both cases, if restrict_to_path is set, we fail if the command
340 contains any slashes, but if restrict_to_path is not set, we must fail the
341 command only if allow_commands is set. */
345 if (ob->restrict_to_path)
347 if (Ustrchr(argv[0], '/') != NULL)
349 addr->transport_return = FAIL;
350 addr->message = string_sprintf("\"/\" found in \"%s\" (command for %s "
351 "transport) - failed for security reasons", cmd, tname);
356 else if (ob->allow_commands)
358 addr->transport_return = FAIL;
359 addr->message = string_sprintf("\"%s\" command not permitted by %s "
360 "transport", argv[0], tname);
365 /* If the command is not an absolute path, search the PATH directories
368 if (argv[0][0] != '/')
372 const uschar *listptr = expand_string(ob->path);
374 while ((p = string_nextinlist(&listptr, &sep, NULL, 0)))
377 sprintf(CS big_buffer, "%.256s/%.256s", p, argv[0]);
378 if (Ustat(big_buffer, &statbuf) == 0)
380 argv[0] = string_copy(big_buffer);
386 addr->transport_return = FAIL;
387 addr->message = string_sprintf("\"%s\" command not found for %s transport",
397 /*************************************************
398 * Set up shell command *
399 *************************************************/
401 /* This function is called when a command line is to be passed to /bin/sh
402 without parsing inside the transport.
405 argvptr pointer to anchor for argv vector
406 cmd points to the command string
407 expand_arguments true if expansion is to occur
408 expand_fail error if expansion fails
409 addr chain of addresses
410 tname the transport name
412 Returns: TRUE if all went well; otherwise an error will be
413 set in the first address and FALSE returned
417 set_up_shell_command(const uschar ***argvptr, uschar *cmd,
418 BOOL expand_arguments, int expand_fail, address_item *addr, uschar *tname)
422 *argvptr = argv = store_get((4)*sizeof(uschar *), GET_UNTAINTED);
424 argv[0] = US"/bin/sh";
427 /* We have to take special action to handle the special "variable" called
428 $pipe_addresses, which is not recognized by the normal expansion function. */
430 if (expand_arguments)
432 uschar * p = Ustrstr(cmd, "pipe_addresses");
436 debug_printf("shell pipe command before expansion:\n %s\n", cmd);
438 /* Allow $recipients in the expansion iff it comes from a system filter */
440 f.enable_dollar_recipients = addr && addr->parent &&
441 Ustrcmp(addr->parent->address, "system-filter") == 0;
444 (p > cmd && p[-1] == '$') ||
445 (p > cmd + 1 && p[-2] == '$' && p[-1] == '{' && p[14] == '}')))
449 if (p[-1] == '{') { q++; p--; }
451 g = string_get(Ustrlen(cmd) + 64);
452 g = string_catn(g, cmd, p - cmd - 1);
454 for (address_item * ad = addr; ad; ad = ad->next)
456 DEBUG(D_transport) if (is_tainted(ad->address))
457 debug_printf("tainted element '%s' from $pipe_addresses\n", ad->address);
459 /*XXX string_append_listele() ? */
460 if (ad != addr) g = string_catn(g, US" ", 1);
461 g = string_cat(g, ad->address);
464 g = string_cat(g, q);
465 argv[2] = (cmd = string_from_gstring(g)) ? expand_string(cmd) : NULL;
468 argv[2] = expand_string(cmd);
470 f.enable_dollar_recipients = FALSE;
474 addr->transport_return = f.search_find_defer ? DEFER : expand_fail;
475 addr->message = string_sprintf("Expansion of command \"%s\" "
476 "in %s transport failed: %s",
477 cmd, tname, expand_string_message);
482 debug_printf("shell pipe command after expansion:\n %s\n", argv[2]);
487 debug_printf("shell pipe command (no expansion):\n %s\n", cmd);
498 /*************************************************
500 *************************************************/
502 /* See local README for interface details. This transport always returns FALSE,
503 indicating that the status in the first address is the status for all addresses
507 pipe_transport_entry(
508 transport_instance *tblock, /* data for this instantiation */
509 address_item *addr) /* address(es) we are working on */
512 int fd_in, fd_out, rc;
516 pipe_transport_options_block *ob =
517 (pipe_transport_options_block *)(tblock->options_block);
518 int timeout = ob->timeout;
519 BOOL written_ok = FALSE;
520 BOOL expand_arguments;
523 const uschar *envlist = ob->environment;
525 uschar *eol = ob->use_crlf ? US"\r\n" : US"\n";
526 transport_ctx tctx = {
529 .check_string = ob->check_string,
530 .escape_string = ob->escape_string,
531 ob->options | topt_not_socket /* set at initialization time */
534 DEBUG(D_transport) debug_printf("%s transport entered\n", tblock->name);
536 /* Set up for the good case */
538 addr->transport_return = OK;
539 addr->basic_errno = 0;
541 /* Pipes are not accepted as general addresses, but they can be generated from
542 .forward files or alias files. In those cases, the pfr flag is set, and the
543 command to be obeyed is pointed to by addr->local_part; it starts with the pipe
544 symbol. In other cases, the command is supplied as one of the pipe transport's
547 if (testflag(addr, af_pfr) && addr->local_part[0] == '|')
548 if (ob->force_command)
550 /* Enables expansion of $address_pipe into separate arguments */
551 setflag(addr, af_force_command);
553 expand_arguments = TRUE;
558 cmd = addr->local_part + 1;
559 while (isspace(*cmd)) cmd++;
560 expand_arguments = testflag(addr, af_expand_pipe);
566 expand_arguments = TRUE;
570 /* If no command has been supplied, we are in trouble.
571 We also check for an empty string since it may be
572 coming from addr->local_part[0] == '|' */
576 addr->transport_return = DEFER;
577 addr->message = string_sprintf("no command specified for %s transport",
583 DEBUG(D_transport) debug_printf("cmd '%s' is tainted\n", cmd);
584 addr->message = string_sprintf("Tainted '%s' (command "
585 "for %s transport) not permitted", cmd, tblock->name);
586 addr->transport_return = PANIC;
590 /* When a pipe is set up by a filter file, there may be values for $thisaddress
591 and numerical the variables in existence. These are passed in
592 addr->pipe_expandn for use here. */
594 if (expand_arguments && addr->pipe_expandn)
596 uschar **ss = addr->pipe_expandn;
598 if (*ss) filter_thisaddress = *ss++;
601 expand_nstring[++expand_nmax] = *ss;
602 expand_nlength[expand_nmax] = Ustrlen(*ss++);
606 /* The default way of processing the command is to split it up into arguments
607 here, and run it directly. This offers some security advantages. However, there
608 are installations that want by default to run commands under /bin/sh always, so
609 there is an option to do that. */
613 if (!set_up_shell_command(&argv, cmd, expand_arguments, expand_fail, addr,
614 tblock->name)) return FALSE;
616 else if (!set_up_direct_command(&argv, cmd, expand_arguments, expand_fail, addr,
617 tblock->name, ob)) return FALSE;
619 expand_nmax = -1; /* Reset */
620 filter_thisaddress = NULL;
622 /* Set up the environment for the command. */
624 envp[envcount++] = string_sprintf("LOCAL_PART=%s", deliver_localpart);
625 envp[envcount++] = string_sprintf("LOGNAME=%s", deliver_localpart);
626 envp[envcount++] = string_sprintf("USER=%s", deliver_localpart);
627 envp[envcount++] = string_sprintf("LOCAL_PART_PREFIX=%#s",
628 deliver_localpart_prefix);
629 envp[envcount++] = string_sprintf("LOCAL_PART_SUFFIX=%#s",
630 deliver_localpart_suffix);
631 envp[envcount++] = string_sprintf("DOMAIN=%s", deliver_domain);
632 envp[envcount++] = string_sprintf("HOME=%#s", deliver_home);
633 envp[envcount++] = string_sprintf("MESSAGE_ID=%s", message_id);
634 envp[envcount++] = string_sprintf("PATH=%s", expand_string(ob->path));
635 envp[envcount++] = string_sprintf("RECIPIENT=%#s%#s%#s@%#s",
636 deliver_localpart_prefix, deliver_localpart, deliver_localpart_suffix,
638 envp[envcount++] = string_sprintf("QUALIFY_DOMAIN=%s", qualify_domain_sender);
639 envp[envcount++] = string_sprintf("SENDER=%s", sender_address);
640 envp[envcount++] = US"SHELL=/bin/sh";
643 envp[envcount++] = string_sprintf("HOST=%s", addr->host_list->name);
645 if (f.timestamps_utc)
646 envp[envcount++] = US"TZ=UTC";
647 else if (timezone_string && timezone_string[0])
648 envp[envcount++] = string_sprintf("TZ=%s", timezone_string);
650 /* Add any requested items */
653 if (!(envlist = expand_cstring(envlist)))
655 addr->transport_return = DEFER;
656 addr->message = string_sprintf("failed to expand string \"%s\" "
657 "for %s transport: %s", ob->environment, tblock->name,
658 expand_string_message);
662 while ((ss = string_nextinlist(&envlist, &envsep, NULL, 0)))
664 if (envcount > nelem(envp) - 2)
666 addr->transport_return = DEFER;
667 addr->basic_errno = E2BIG;
668 addr->message = string_sprintf("too many environment settings for "
669 "%s transport", tblock->name);
672 envp[envcount++] = string_copy(ss);
675 envp[envcount] = NULL;
677 /* If the -N option is set, can't do any more. */
682 debug_printf("*** delivery by %s transport bypassed by -N option",
688 /* Handling the output from the pipe is tricky. If a file for catching this
689 output is provided, we could in theory just hand that fd over to the process,
690 but this isn't very safe because it might loop and carry on writing for
691 ever (which is exactly what happened in early versions of Exim). Therefore we
692 use the standard child_open() function, which creates pipes. We can then read
693 our end of the output pipe and count the number of bytes that come through,
694 chopping the sub-process if it exceeds some limit.
696 However, this means we want to run a sub-process with both its input and output
697 attached to pipes. We can't handle that easily from a single parent process
698 using straightforward code such as the transport_write_message() function
699 because the subprocess might not be reading its input because it is trying to
700 write to a full output pipe. The complication of redesigning the world to
701 handle this is too great - simpler just to run another process to do the
702 reading of the output pipe. */
705 /* As this is a local transport, we are already running with the required
706 uid/gid and current directory. Request that the new process be a process group
707 leader, so we can kill it and all its children on a timeout. */
709 if ((pid = child_open(USS argv, envp, ob->umask, &fd_in, &fd_out, TRUE,
710 US"pipe-tpt-cmd")) < 0)
712 addr->transport_return = DEFER;
713 addr->message = string_sprintf(
714 "Failed to create child process for %s transport: %s", tblock->name,
720 /* Now fork a process to handle the output that comes down the pipe. */
722 if ((outpid = exim_fork(US"pipe-tpt-output")) < 0)
724 addr->basic_errno = errno;
725 addr->transport_return = DEFER;
726 addr->message = string_sprintf(
727 "Failed to create process for handling output in %s transport",
734 /* This is the code for the output-handling subprocess. Read from the pipe
735 in chunks, and write to the return file if one is provided. Keep track of
736 the number of bytes handled. If the limit is exceeded, try to kill the
737 subprocess group, and in any case close the pipe and exit, which should cause
738 the subprocess to fail. */
744 set_process_info("reading output from |%s", cmd);
745 while ((rc = read(fd_out, big_buffer, big_buffer_size)) > 0)
747 if (addr->return_file >= 0)
748 if(write(addr->return_file, big_buffer, rc) != rc)
749 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
751 if (count > ob->max_output)
753 DEBUG(D_transport) debug_printf("Too much output from pipe - killed\n");
754 if (addr->return_file >= 0)
756 uschar *message = US"\n\n*** Too much output - remainder discarded ***\n";
757 rc = Ustrlen(message);
758 if(write(addr->return_file, message, rc) != rc)
759 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
761 killpg(pid, SIGKILL);
769 (void)close(fd_out); /* Not used in this process */
772 /* Carrying on now with the main parent process. Attempt to write the message
773 to it down the pipe. It is a fallacy to think that you can detect write errors
774 when the sub-process fails to read the pipe. The parent process may complete
775 writing and close the pipe before the sub-process completes. We could sleep a
776 bit here to let the sub-process get going, but it may still not complete. So we
777 ignore all writing errors. (When in the test harness, we do do a short sleep so
778 any debugging output is likely to be in the same order.) */
780 testharness_pause_ms(500);
782 DEBUG(D_transport) debug_printf("Writing message to pipe\n");
784 /* Arrange to time out writes if there is a timeout set. */
788 sigalrm_seen = FALSE;
789 transport_write_timeout = timeout;
792 /* Reset the counter of bytes written */
796 /* First write any configured prefix information */
798 if (ob->message_prefix)
800 uschar *prefix = expand_string(ob->message_prefix);
803 addr->transport_return = f.search_find_defer? DEFER : PANIC;
804 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
805 "transport) failed: %s", ob->message_prefix, tblock->name,
806 expand_string_message);
809 if (!transport_write_block(&tctx, prefix, Ustrlen(prefix), FALSE))
813 /* If the use_bsmtp option is set, we need to write SMTP prefix information.
814 The various different values for batching are handled outside; if there is more
815 than one address available here, all must be included. Force SMTP dot-handling.
820 if (!transport_write_string(fd_in, "MAIL FROM:<%s>%s", return_path, eol))
823 for (address_item * a = addr; a; a = a->next)
824 if (!transport_write_string(fd_in,
826 transport_rcpt_address(a, tblock->rcpt_include_affixes),
830 if (!transport_write_string(fd_in, "DATA%s", eol)) goto END_WRITE;
833 /* Now the actual message */
835 if (!transport_write_message(&tctx, 0))
838 /* Now any configured suffix */
840 if (ob->message_suffix)
842 uschar *suffix = expand_string(ob->message_suffix);
845 addr->transport_return = f.search_find_defer? DEFER : PANIC;
846 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
847 "transport) failed: %s", ob->message_suffix, tblock->name,
848 expand_string_message);
851 if (!transport_write_block(&tctx, suffix, Ustrlen(suffix), FALSE))
855 /* If local_smtp, write the terminating dot. */
857 if (ob->use_bsmtp && !transport_write_string(fd_in, ".%s", eol))
860 /* Flag all writing completed successfully. */
864 /* Come here if there are errors during writing. */
868 /* OK, the writing is now all done. Close the pipe. */
872 /* Handle errors during writing. For timeouts, set the timeout for waiting for
873 the child process to 1 second. If the process at the far end of the pipe died
874 without reading all of it, we expect an EPIPE error, which should be ignored.
875 We used also to ignore WRITEINCOMPLETE but the writing function is now cleverer
876 at handling OS where the death of a pipe doesn't give EPIPE immediately. See
881 if (errno == ETIMEDOUT)
883 addr->message = string_sprintf("%stimeout while writing to pipe",
884 f.transport_filter_timed_out ? "transport filter " : "");
885 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
888 else if (errno == EPIPE)
890 debug_printf("transport error EPIPE ignored\n");
894 addr->transport_return = PANIC;
895 addr->basic_errno = errno;
896 if (errno == ERRNO_CHHEADER_FAIL)
898 string_sprintf("Failed to expand headers_add or headers_remove: %s",
899 expand_string_message);
900 else if (errno == ERRNO_FILTER_FAIL)
901 addr->message = string_sprintf("Transport filter process failed (%d)%s",
903 (addr->more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
904 else if (errno == ERRNO_WRITEINCOMPLETE)
905 addr->message = US"Failed repeatedly to write data";
907 addr->message = string_sprintf("Error %d", errno);
912 /* Wait for the child process to complete and take action if the returned
913 status is nonzero. The timeout will be just 1 second if any of the writes
916 if ((rc = child_close(pid, timeout)) != 0)
918 uschar * tmsg = addr->message
919 ? string_sprintf(" (preceded by %s)", addr->message) : US"";
921 /* The process did not complete in time; kill its process group and fail
922 the delivery. It appears to be necessary to kill the output process too, as
923 otherwise it hangs on for some time if the actual pipe process is sleeping.
924 (At least, that's what I observed on Solaris 2.5.1.) Since we are failing
925 the delivery, that shouldn't cause any problem. */
929 killpg(pid, SIGKILL);
930 kill(outpid, SIGKILL);
931 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
932 addr->message = string_sprintf("pipe delivery process timed out%s", tmsg);
939 addr->transport_return = PANIC;
940 addr->message = string_sprintf("Wait() failed for child process of %s "
941 "transport: %s%s", tblock->name, strerror(errno), tmsg);
944 /* Since the transport_filter timed out we assume it has sent the child process
945 a malformed or incomplete data stream. Kill off the child process
946 and prevent checking its exit status as it will has probably exited in error.
947 This prevents the transport_filter timeout message from getting overwritten
948 by the exit error which is not the cause of the problem. */
950 else if (f.transport_filter_timed_out)
952 killpg(pid, SIGKILL);
953 kill(outpid, SIGKILL);
956 /* Either the process completed, but yielded a non-zero (necessarily
957 positive) status, or the process was terminated by a signal (rc will contain
958 the negation of the signal number). Treat killing by signal as failure unless
959 status is being ignored. By default, the message is bounced back, unless
960 freeze_signal is set, in which case it is frozen instead. */
964 if (ob->freeze_signal)
966 addr->transport_return = DEFER;
967 addr->special_action = SPECIAL_FREEZE;
968 addr->message = string_sprintf("Child process of %s transport (running "
969 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
970 -rc, os_strsignal(-rc), tmsg);
972 else if (!ob->ignore_status)
974 addr->transport_return = FAIL;
975 addr->message = string_sprintf("Child process of %s transport (running "
976 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
977 -rc, os_strsignal(-rc), tmsg);
981 /* For positive values (process terminated with non-zero status), we need a
982 status code to request deferral. A number of systems contain the following
985 #define EX_TEMPFAIL 75
989 EX_TEMPFAIL -- temporary failure, indicating something that
990 is not really an error. In sendmail, this means
991 that a mailer (e.g.) could not create a connection,
992 and the request should be reattempted later.
994 Based on this, we use exit code EX_TEMPFAIL as a default to mean "defer" when
995 not ignoring the returned status. However, there is now an option that
996 contains a list of temporary codes, with TEMPFAIL and CANTCREAT as defaults.
998 Another case that needs special treatment is if execve() failed (typically
999 the command that was given is a non-existent path). By default this is
1000 treated as just another failure, but if freeze_exec_fail is set, the reaction
1001 is to freeze the message rather than bounce the address. Exim used to signal
1002 this failure with EX_UNAVAILABLE, which is defined in many systems as
1004 #define EX_UNAVAILABLE 69
1006 with the description
1008 EX_UNAVAILABLE -- A service is unavailable. This can occur
1009 if a support program or file does not exist. This
1010 can also be used as a catchall message when something
1011 you wanted to do doesn't work, but you don't know why.
1013 However, this can be confused with a command that actually returns 69 because
1014 something *it* wanted is unavailable. At release 4.21, Exim was changed to
1015 use return code 127 instead, because this is what the shell returns when it
1016 is unable to exec a command. We define it as EX_EXECFAILED, and use it in
1017 child.c to signal execve() failure and other unexpected failures such as
1018 setuid() not working - though that won't be the case here because we aren't
1023 /* Always handle execve() failure specially if requested to */
1025 if (ob->freeze_exec_fail && rc == EX_EXECFAILED)
1027 addr->transport_return = DEFER;
1028 addr->special_action = SPECIAL_FREEZE;
1029 addr->message = string_sprintf("pipe process failed to exec \"%s\"%s",
1033 /* Otherwise take action only if not ignoring status */
1035 else if (!ob->ignore_status)
1040 /* If temp_errors is "*" all codes are temporary. Initialization checks
1041 that it's either "*" or a list of numbers. If not "*", scan the list of
1042 temporary failure codes; if any match, the result is DEFER. */
1044 if (ob->temp_errors[0] == '*')
1045 addr->transport_return = DEFER;
1049 const uschar *s = ob->temp_errors;
1053 addr->transport_return = FAIL;
1054 while ((p = string_nextinlist(&s,&sep,NULL,0)))
1055 if (rc == Uatoi(p)) { addr->transport_return = DEFER; break; }
1058 /* Ensure the message contains the expanded command and arguments. This
1059 doesn't have to be brilliantly efficient - it is an error situation. */
1061 addr->message = string_sprintf("Child process of %s transport returned "
1062 "%d", tblock->name, rc);
1063 g = string_cat(NULL, addr->message);
1065 /* If the return code is > 128, it often means that a shell command
1066 was terminated by a signal. */
1069 string_sprintf("(could mean shell command ended by signal %d (%s))",
1070 rc-128, os_strsignal(rc-128)) :
1075 g = string_catn(g, US" ", 1);
1076 g = string_cat (g, ss);
1079 /* Now add the command and arguments */
1081 g = string_catn(g, US" from command:", 14);
1083 for (int i = 0; i < sizeof(argv)/sizeof(int *) && argv[i] != NULL; i++)
1086 g = string_catn(g, US" ", 1);
1087 if (Ustrpbrk(argv[i], " \t") != NULL)
1090 g = string_catn(g, US"\"", 1);
1092 g = string_cat(g, argv[i]);
1094 g = string_catn(g, US"\"", 1);
1097 /* Add previous filter timeout message, if present. */
1100 g = string_cat(g, tmsg);
1102 addr->message = string_from_gstring(g);
1107 /* Ensure all subprocesses (in particular, the output handling process)
1108 are complete before we pass this point. */
1110 while (wait(&rc) >= 0);
1112 DEBUG(D_transport) debug_printf("%s transport yielded %d\n", tblock->name,
1113 addr->transport_return);
1115 /* If there has been a problem, the message in addr->message contains details
1116 of the pipe command. We don't want to expose these to the world, so we set up
1117 something bland to return to the sender. */
1119 if (addr->transport_return != OK)
1120 addr->user_message = US"local delivery failed";
1125 #endif /*!MACRO_PREDEF*/
1126 /* End of transport/pipe.c */