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, expand_arguments, expand_fail,
308 addr, FALSE, string_sprintf("%.50s transport", tname), NULL))
311 /* Point to the set-up arguments. */
315 /* If allow_commands is set, see if the command is in the permitted list. */
317 if (ob->allow_commands)
323 if (!(s = expand_string(ob->allow_commands)))
325 addr->transport_return = DEFER;
326 addr->message = string_sprintf("failed to expand string \"%s\" "
327 "for %s transport: %s", ob->allow_commands, tname, expand_string_message);
331 while ((p = string_nextinlist(&s, &sep, NULL, 0)))
332 if (Ustrcmp(p, argv[0]) == 0) { permitted = TRUE; break; }
335 /* If permitted is TRUE it means the command was found in the allowed list, and
336 no further checks are done. If permitted = FALSE, it either means
337 allow_commands wasn't set, or that the command didn't match anything in the
338 list. In both cases, if restrict_to_path is set, we fail if the command
339 contains any slashes, but if restrict_to_path is not set, we must fail the
340 command only if allow_commands is set. */
344 if (ob->restrict_to_path)
346 if (Ustrchr(argv[0], '/') != NULL)
348 addr->transport_return = FAIL;
349 addr->message = string_sprintf("\"/\" found in \"%s\" (command for %s "
350 "transport) - failed for security reasons", cmd, tname);
355 else if (ob->allow_commands)
357 addr->transport_return = FAIL;
358 addr->message = string_sprintf("\"%s\" command not permitted by %s "
359 "transport", argv[0], tname);
364 /* If the command is not an absolute path, search the PATH directories
367 if (argv[0][0] != '/')
371 const uschar *listptr = expand_string(ob->path);
373 while ((p = string_nextinlist(&listptr, &sep, NULL, 0)))
376 sprintf(CS big_buffer, "%.256s/%.256s", p, argv[0]);
377 if (Ustat(big_buffer, &statbuf) == 0)
379 argv[0] = string_copy(big_buffer);
385 addr->transport_return = FAIL;
386 addr->message = string_sprintf("\"%s\" command not found for %s transport",
396 /*************************************************
397 * Set up shell command *
398 *************************************************/
400 /* This function is called when a command line is to be passed to /bin/sh
401 without parsing inside the transport.
404 argvptr pointer to anchor for argv vector
405 cmd points to the command string
406 expand_arguments true if expansion is to occur
407 expand_fail error if expansion fails
408 addr chain of addresses
409 tname the transport name
411 Returns: TRUE if all went well; otherwise an error will be
412 set in the first address and FALSE returned
416 set_up_shell_command(const uschar ***argvptr, uschar *cmd,
417 BOOL expand_arguments, int expand_fail, address_item *addr, uschar *tname)
421 *argvptr = argv = store_get((4)*sizeof(uschar *), GET_UNTAINTED);
423 argv[0] = US"/bin/sh";
426 /* We have to take special action to handle the special "variable" called
427 $pipe_addresses, which is not recognized by the normal expansion function. */
429 if (expand_arguments)
431 uschar * p = Ustrstr(cmd, "pipe_addresses");
435 debug_printf("shell pipe command before expansion:\n %s\n", cmd);
437 /* Allow $recipients in the expansion iff it comes from a system filter */
439 f.enable_dollar_recipients = addr && addr->parent &&
440 Ustrcmp(addr->parent->address, "system-filter") == 0;
443 (p > cmd && p[-1] == '$') ||
444 (p > cmd + 1 && p[-2] == '$' && p[-1] == '{' && p[14] == '}')))
448 if (p[-1] == '{') { q++; p--; }
450 g = string_get(Ustrlen(cmd) + 64);
451 g = string_catn(g, cmd, p - cmd - 1);
453 for (address_item * ad = addr; ad; ad = ad->next)
455 DEBUG(D_transport) if (is_tainted(ad->address))
456 debug_printf("tainted element '%s' from $pipe_addresses\n", ad->address);
458 /*XXX string_append_listele() ? */
459 if (ad != addr) g = string_catn(g, US" ", 1);
460 g = string_cat(g, ad->address);
463 g = string_cat(g, q);
464 argv[2] = (cmd = string_from_gstring(g)) ? expand_string(cmd) : NULL;
467 argv[2] = expand_string(cmd);
469 f.enable_dollar_recipients = FALSE;
473 addr->transport_return = f.search_find_defer ? DEFER : expand_fail;
474 addr->message = string_sprintf("Expansion of command \"%s\" "
475 "in %s transport failed: %s",
476 cmd, tname, expand_string_message);
481 debug_printf("shell pipe command after expansion:\n %s\n", argv[2]);
486 debug_printf("shell pipe command (no expansion):\n %s\n", cmd);
497 /*************************************************
499 *************************************************/
501 /* See local README for interface details. This transport always returns FALSE,
502 indicating that the status in the first address is the status for all addresses
506 pipe_transport_entry(
507 transport_instance *tblock, /* data for this instantiation */
508 address_item *addr) /* address(es) we are working on */
511 int fd_in, fd_out, rc;
515 pipe_transport_options_block *ob =
516 (pipe_transport_options_block *)(tblock->options_block);
517 int timeout = ob->timeout;
518 BOOL written_ok = FALSE;
519 BOOL expand_arguments;
522 const uschar *envlist = ob->environment;
524 uschar *eol = ob->use_crlf ? US"\r\n" : US"\n";
525 transport_ctx tctx = {
528 .check_string = ob->check_string,
529 .escape_string = ob->escape_string,
530 ob->options | topt_not_socket /* set at initialization time */
533 DEBUG(D_transport) debug_printf("%s transport entered\n", tblock->name);
535 /* Set up for the good case */
537 addr->transport_return = OK;
538 addr->basic_errno = 0;
540 /* Pipes are not accepted as general addresses, but they can be generated from
541 .forward files or alias files. In those cases, the pfr flag is set, and the
542 command to be obeyed is pointed to by addr->local_part; it starts with the pipe
543 symbol. In other cases, the command is supplied as one of the pipe transport's
546 if (testflag(addr, af_pfr) && addr->local_part[0] == '|')
547 if (ob->force_command)
549 /* Enables expansion of $address_pipe into separate arguments */
550 setflag(addr, af_force_command);
552 expand_arguments = TRUE;
557 cmd = addr->local_part + 1;
558 while (isspace(*cmd)) cmd++;
559 expand_arguments = testflag(addr, af_expand_pipe);
565 expand_arguments = TRUE;
569 /* If no command has been supplied, we are in trouble.
570 We also check for an empty string since it may be
571 coming from addr->local_part[0] == '|' */
575 addr->transport_return = DEFER;
576 addr->message = string_sprintf("no command specified for %s transport",
582 DEBUG(D_transport) debug_printf("cmd '%s' is tainted\n", cmd);
583 addr->message = string_sprintf("Tainted '%s' (command "
584 "for %s transport) not permitted", cmd, tblock->name);
585 addr->transport_return = PANIC;
589 /* When a pipe is set up by a filter file, there may be values for $thisaddress
590 and numerical the variables in existence. These are passed in
591 addr->pipe_expandn for use here. */
593 if (expand_arguments && addr->pipe_expandn)
595 uschar **ss = addr->pipe_expandn;
597 if (*ss) filter_thisaddress = *ss++;
600 expand_nstring[++expand_nmax] = *ss;
601 expand_nlength[expand_nmax] = Ustrlen(*ss++);
605 /* The default way of processing the command is to split it up into arguments
606 here, and run it directly. This offers some security advantages. However, there
607 are installations that want by default to run commands under /bin/sh always, so
608 there is an option to do that. */
612 if (!set_up_shell_command(&argv, cmd, expand_arguments, expand_fail, addr,
613 tblock->name)) return FALSE;
615 else if (!set_up_direct_command(&argv, cmd, expand_arguments, expand_fail, addr,
616 tblock->name, ob)) return FALSE;
618 expand_nmax = -1; /* Reset */
619 filter_thisaddress = NULL;
621 /* Set up the environment for the command. */
623 envp[envcount++] = string_sprintf("LOCAL_PART=%s", deliver_localpart);
624 envp[envcount++] = string_sprintf("LOGNAME=%s", deliver_localpart);
625 envp[envcount++] = string_sprintf("USER=%s", deliver_localpart);
626 envp[envcount++] = string_sprintf("LOCAL_PART_PREFIX=%#s",
627 deliver_localpart_prefix);
628 envp[envcount++] = string_sprintf("LOCAL_PART_SUFFIX=%#s",
629 deliver_localpart_suffix);
630 envp[envcount++] = string_sprintf("DOMAIN=%s", deliver_domain);
631 envp[envcount++] = string_sprintf("HOME=%#s", deliver_home);
632 envp[envcount++] = string_sprintf("MESSAGE_ID=%s", message_id);
633 envp[envcount++] = string_sprintf("PATH=%s", expand_string(ob->path));
634 envp[envcount++] = string_sprintf("RECIPIENT=%#s%#s%#s@%#s",
635 deliver_localpart_prefix, deliver_localpart, deliver_localpart_suffix,
637 envp[envcount++] = string_sprintf("QUALIFY_DOMAIN=%s", qualify_domain_sender);
638 envp[envcount++] = string_sprintf("SENDER=%s", sender_address);
639 envp[envcount++] = US"SHELL=/bin/sh";
642 envp[envcount++] = string_sprintf("HOST=%s", addr->host_list->name);
644 if (f.timestamps_utc)
645 envp[envcount++] = US"TZ=UTC";
646 else if (timezone_string && timezone_string[0])
647 envp[envcount++] = string_sprintf("TZ=%s", timezone_string);
649 /* Add any requested items */
652 if (!(envlist = expand_cstring(envlist)))
654 addr->transport_return = DEFER;
655 addr->message = string_sprintf("failed to expand string \"%s\" "
656 "for %s transport: %s", ob->environment, tblock->name,
657 expand_string_message);
661 while ((ss = string_nextinlist(&envlist, &envsep, NULL, 0)))
663 if (envcount > nelem(envp) - 2)
665 addr->transport_return = DEFER;
666 addr->basic_errno = E2BIG;
667 addr->message = string_sprintf("too many environment settings for "
668 "%s transport", tblock->name);
671 envp[envcount++] = string_copy(ss);
674 envp[envcount] = NULL;
676 /* If the -N option is set, can't do any more. */
681 debug_printf("*** delivery by %s transport bypassed by -N option",
687 /* Handling the output from the pipe is tricky. If a file for catching this
688 output is provided, we could in theory just hand that fd over to the process,
689 but this isn't very safe because it might loop and carry on writing for
690 ever (which is exactly what happened in early versions of Exim). Therefore we
691 use the standard child_open() function, which creates pipes. We can then read
692 our end of the output pipe and count the number of bytes that come through,
693 chopping the sub-process if it exceeds some limit.
695 However, this means we want to run a sub-process with both its input and output
696 attached to pipes. We can't handle that easily from a single parent process
697 using straightforward code such as the transport_write_message() function
698 because the subprocess might not be reading its input because it is trying to
699 write to a full output pipe. The complication of redesigning the world to
700 handle this is too great - simpler just to run another process to do the
701 reading of the output pipe. */
704 /* As this is a local transport, we are already running with the required
705 uid/gid and current directory. Request that the new process be a process group
706 leader, so we can kill it and all its children on a timeout. */
708 if ((pid = child_open(USS argv, envp, ob->umask, &fd_in, &fd_out, TRUE,
709 US"pipe-tpt-cmd")) < 0)
711 addr->transport_return = DEFER;
712 addr->message = string_sprintf(
713 "Failed to create child process for %s transport: %s", tblock->name,
719 /* Now fork a process to handle the output that comes down the pipe. */
721 if ((outpid = exim_fork(US"pipe-tpt-output")) < 0)
723 addr->basic_errno = errno;
724 addr->transport_return = DEFER;
725 addr->message = string_sprintf(
726 "Failed to create process for handling output in %s transport",
733 /* This is the code for the output-handling subprocess. Read from the pipe
734 in chunks, and write to the return file if one is provided. Keep track of
735 the number of bytes handled. If the limit is exceeded, try to kill the
736 subprocess group, and in any case close the pipe and exit, which should cause
737 the subprocess to fail. */
743 set_process_info("reading output from |%s", cmd);
744 while ((rc = read(fd_out, big_buffer, big_buffer_size)) > 0)
746 if (addr->return_file >= 0)
747 if(write(addr->return_file, big_buffer, rc) != rc)
748 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
750 if (count > ob->max_output)
752 DEBUG(D_transport) debug_printf("Too much output from pipe - killed\n");
753 if (addr->return_file >= 0)
755 uschar *message = US"\n\n*** Too much output - remainder discarded ***\n";
756 rc = Ustrlen(message);
757 if(write(addr->return_file, message, rc) != rc)
758 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
760 killpg(pid, SIGKILL);
768 (void)close(fd_out); /* Not used in this process */
771 /* Carrying on now with the main parent process. Attempt to write the message
772 to it down the pipe. It is a fallacy to think that you can detect write errors
773 when the sub-process fails to read the pipe. The parent process may complete
774 writing and close the pipe before the sub-process completes. We could sleep a
775 bit here to let the sub-process get going, but it may still not complete. So we
776 ignore all writing errors. (When in the test harness, we do do a short sleep so
777 any debugging output is likely to be in the same order.) */
779 testharness_pause_ms(500);
781 DEBUG(D_transport) debug_printf("Writing message to pipe\n");
783 /* Arrange to time out writes if there is a timeout set. */
787 sigalrm_seen = FALSE;
788 transport_write_timeout = timeout;
791 /* Reset the counter of bytes written */
795 /* First write any configured prefix information */
797 if (ob->message_prefix)
799 uschar *prefix = expand_string(ob->message_prefix);
802 addr->transport_return = f.search_find_defer? DEFER : PANIC;
803 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
804 "transport) failed: %s", ob->message_prefix, tblock->name,
805 expand_string_message);
808 if (!transport_write_block(&tctx, prefix, Ustrlen(prefix), FALSE))
812 /* If the use_bsmtp option is set, we need to write SMTP prefix information.
813 The various different values for batching are handled outside; if there is more
814 than one address available here, all must be included. Force SMTP dot-handling.
819 if (!transport_write_string(fd_in, "MAIL FROM:<%s>%s", return_path, eol))
822 for (address_item * a = addr; a; a = a->next)
823 if (!transport_write_string(fd_in,
825 transport_rcpt_address(a, tblock->rcpt_include_affixes),
829 if (!transport_write_string(fd_in, "DATA%s", eol)) goto END_WRITE;
832 /* Now the actual message */
834 if (!transport_write_message(&tctx, 0))
837 /* Now any configured suffix */
839 if (ob->message_suffix)
841 uschar *suffix = expand_string(ob->message_suffix);
844 addr->transport_return = f.search_find_defer? DEFER : PANIC;
845 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
846 "transport) failed: %s", ob->message_suffix, tblock->name,
847 expand_string_message);
850 if (!transport_write_block(&tctx, suffix, Ustrlen(suffix), FALSE))
854 /* If local_smtp, write the terminating dot. */
856 if (ob->use_bsmtp && !transport_write_string(fd_in, ".%s", eol))
859 /* Flag all writing completed successfully. */
863 /* Come here if there are errors during writing. */
867 /* OK, the writing is now all done. Close the pipe. */
871 /* Handle errors during writing. For timeouts, set the timeout for waiting for
872 the child process to 1 second. If the process at the far end of the pipe died
873 without reading all of it, we expect an EPIPE error, which should be ignored.
874 We used also to ignore WRITEINCOMPLETE but the writing function is now cleverer
875 at handling OS where the death of a pipe doesn't give EPIPE immediately. See
880 if (errno == ETIMEDOUT)
882 addr->message = string_sprintf("%stimeout while writing to pipe",
883 f.transport_filter_timed_out ? "transport filter " : "");
884 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
887 else if (errno == EPIPE)
889 debug_printf("transport error EPIPE ignored\n");
893 addr->transport_return = PANIC;
894 addr->basic_errno = errno;
895 if (errno == ERRNO_CHHEADER_FAIL)
897 string_sprintf("Failed to expand headers_add or headers_remove: %s",
898 expand_string_message);
899 else if (errno == ERRNO_FILTER_FAIL)
900 addr->message = string_sprintf("Transport filter process failed (%d)%s",
902 (addr->more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
903 else if (errno == ERRNO_WRITEINCOMPLETE)
904 addr->message = US"Failed repeatedly to write data";
906 addr->message = string_sprintf("Error %d", errno);
911 /* Wait for the child process to complete and take action if the returned
912 status is nonzero. The timeout will be just 1 second if any of the writes
915 if ((rc = child_close(pid, timeout)) != 0)
917 uschar * tmsg = addr->message
918 ? string_sprintf(" (preceded by %s)", addr->message) : US"";
920 /* The process did not complete in time; kill its process group and fail
921 the delivery. It appears to be necessary to kill the output process too, as
922 otherwise it hangs on for some time if the actual pipe process is sleeping.
923 (At least, that's what I observed on Solaris 2.5.1.) Since we are failing
924 the delivery, that shouldn't cause any problem. */
928 killpg(pid, SIGKILL);
929 kill(outpid, SIGKILL);
930 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
931 addr->message = string_sprintf("pipe delivery process timed out%s", tmsg);
938 addr->transport_return = PANIC;
939 addr->message = string_sprintf("Wait() failed for child process of %s "
940 "transport: %s%s", tblock->name, strerror(errno), tmsg);
943 /* Since the transport_filter timed out we assume it has sent the child process
944 a malformed or incomplete data stream. Kill off the child process
945 and prevent checking its exit status as it will has probably exited in error.
946 This prevents the transport_filter timeout message from getting overwritten
947 by the exit error which is not the cause of the problem. */
949 else if (f.transport_filter_timed_out)
951 killpg(pid, SIGKILL);
952 kill(outpid, SIGKILL);
955 /* Either the process completed, but yielded a non-zero (necessarily
956 positive) status, or the process was terminated by a signal (rc will contain
957 the negation of the signal number). Treat killing by signal as failure unless
958 status is being ignored. By default, the message is bounced back, unless
959 freeze_signal is set, in which case it is frozen instead. */
963 if (ob->freeze_signal)
965 addr->transport_return = DEFER;
966 addr->special_action = SPECIAL_FREEZE;
967 addr->message = string_sprintf("Child process of %s transport (running "
968 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
969 -rc, os_strsignal(-rc), tmsg);
971 else if (!ob->ignore_status)
973 addr->transport_return = FAIL;
974 addr->message = string_sprintf("Child process of %s transport (running "
975 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
976 -rc, os_strsignal(-rc), tmsg);
980 /* For positive values (process terminated with non-zero status), we need a
981 status code to request deferral. A number of systems contain the following
984 #define EX_TEMPFAIL 75
988 EX_TEMPFAIL -- temporary failure, indicating something that
989 is not really an error. In sendmail, this means
990 that a mailer (e.g.) could not create a connection,
991 and the request should be reattempted later.
993 Based on this, we use exit code EX_TEMPFAIL as a default to mean "defer" when
994 not ignoring the returned status. However, there is now an option that
995 contains a list of temporary codes, with TEMPFAIL and CANTCREAT as defaults.
997 Another case that needs special treatment is if execve() failed (typically
998 the command that was given is a non-existent path). By default this is
999 treated as just another failure, but if freeze_exec_fail is set, the reaction
1000 is to freeze the message rather than bounce the address. Exim used to signal
1001 this failure with EX_UNAVAILABLE, which is defined in many systems as
1003 #define EX_UNAVAILABLE 69
1005 with the description
1007 EX_UNAVAILABLE -- A service is unavailable. This can occur
1008 if a support program or file does not exist. This
1009 can also be used as a catchall message when something
1010 you wanted to do doesn't work, but you don't know why.
1012 However, this can be confused with a command that actually returns 69 because
1013 something *it* wanted is unavailable. At release 4.21, Exim was changed to
1014 use return code 127 instead, because this is what the shell returns when it
1015 is unable to exec a command. We define it as EX_EXECFAILED, and use it in
1016 child.c to signal execve() failure and other unexpected failures such as
1017 setuid() not working - though that won't be the case here because we aren't
1022 /* Always handle execve() failure specially if requested to */
1024 if (ob->freeze_exec_fail && rc == EX_EXECFAILED)
1026 addr->transport_return = DEFER;
1027 addr->special_action = SPECIAL_FREEZE;
1028 addr->message = string_sprintf("pipe process failed to exec \"%s\"%s",
1032 /* Otherwise take action only if not ignoring status */
1034 else if (!ob->ignore_status)
1039 /* If temp_errors is "*" all codes are temporary. Initialization checks
1040 that it's either "*" or a list of numbers. If not "*", scan the list of
1041 temporary failure codes; if any match, the result is DEFER. */
1043 if (ob->temp_errors[0] == '*')
1044 addr->transport_return = DEFER;
1048 const uschar *s = ob->temp_errors;
1052 addr->transport_return = FAIL;
1053 while ((p = string_nextinlist(&s,&sep,NULL,0)))
1054 if (rc == Uatoi(p)) { addr->transport_return = DEFER; break; }
1057 /* Ensure the message contains the expanded command and arguments. This
1058 doesn't have to be brilliantly efficient - it is an error situation. */
1060 addr->message = string_sprintf("Child process of %s transport returned "
1061 "%d", tblock->name, rc);
1062 g = string_cat(NULL, addr->message);
1064 /* If the return code is > 128, it often means that a shell command
1065 was terminated by a signal. */
1068 string_sprintf("(could mean shell command ended by signal %d (%s))",
1069 rc-128, os_strsignal(rc-128)) :
1074 g = string_catn(g, US" ", 1);
1075 g = string_cat (g, ss);
1078 /* Now add the command and arguments */
1080 g = string_catn(g, US" from command:", 14);
1082 for (int i = 0; i < sizeof(argv)/sizeof(int *) && argv[i] != NULL; i++)
1085 g = string_catn(g, US" ", 1);
1086 if (Ustrpbrk(argv[i], " \t") != NULL)
1089 g = string_catn(g, US"\"", 1);
1091 g = string_cat(g, argv[i]);
1093 g = string_catn(g, US"\"", 1);
1096 /* Add previous filter timeout message, if present. */
1099 g = string_cat(g, tmsg);
1101 addr->message = string_from_gstring(g);
1106 /* Ensure all subprocesses (in particular, the output handling process)
1107 are complete before we pass this point. */
1109 while (wait(&rc) >= 0);
1111 DEBUG(D_transport) debug_printf("%s transport yielded %d\n", tblock->name,
1112 addr->transport_return);
1114 /* If there has been a problem, the message in addr->message contains details
1115 of the pipe command. We don't want to expose these to the world, so we set up
1116 something bland to return to the sender. */
1118 if (addr->transport_return != OK)
1119 addr->user_message = US"local delivery failed";
1124 #endif /*!MACRO_PREDEF*/
1125 /* End of transport/pipe.c */