1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim maintainers 2020 - 2021 */
7 /* See the file NOTICE for conditions of use and distribution. */
13 #ifdef HAVE_SETCLASSRESOURCES
14 #include <login_cap.h>
19 /* Options specific to the pipe transport. They must be in alphabetic
20 order (note that "_" comes before the lower case letters). Those starting
21 with "*" are not settable by the user but are used by the option-reading
22 software for alternative value types. Some options are stored in the transport
23 instance block so as to be publicly visible; these are flagged with opt_public.
25 #define LOFF(field) OPT_OFF(pipe_transport_options_block, field)
27 optionlist pipe_transport_options[] = {
28 { "allow_commands", opt_stringptr, LOFF(allow_commands) },
29 { "batch_id", opt_stringptr | opt_public,
30 OPT_OFF(transport_instance, batch_id) },
31 { "batch_max", opt_int | opt_public,
32 OPT_OFF(transport_instance, batch_max) },
33 { "check_string", opt_stringptr, LOFF(check_string) },
34 { "command", opt_stringptr, LOFF(cmd) },
35 { "environment", opt_stringptr, LOFF(environment) },
36 { "escape_string", opt_stringptr, LOFF(escape_string) },
37 { "force_command", opt_bool, LOFF(force_command) },
38 { "freeze_exec_fail", opt_bool, LOFF(freeze_exec_fail) },
39 { "freeze_signal", opt_bool, LOFF(freeze_signal) },
40 { "ignore_status", opt_bool, LOFF(ignore_status) },
41 { "log_defer_output", opt_bool | opt_public,
42 OPT_OFF(transport_instance, log_defer_output) },
43 { "log_fail_output", opt_bool | opt_public,
44 OPT_OFF(transport_instance, log_fail_output) },
45 { "log_output", opt_bool | opt_public,
46 OPT_OFF(transport_instance, log_output) },
47 { "max_output", opt_mkint, LOFF(max_output) },
48 { "message_prefix", opt_stringptr, LOFF(message_prefix) },
49 { "message_suffix", opt_stringptr, LOFF(message_suffix) },
50 { "path", opt_stringptr, LOFF(path) },
51 { "permit_coredump", opt_bool, LOFF(permit_coredump) },
52 { "pipe_as_creator", opt_bool | opt_public,
53 OPT_OFF(transport_instance, deliver_as_creator) },
54 { "restrict_to_path", opt_bool, LOFF(restrict_to_path) },
55 { "return_fail_output",opt_bool | opt_public,
56 OPT_OFF(transport_instance, return_fail_output) },
57 { "return_output", opt_bool | opt_public,
58 OPT_OFF(transport_instance, return_output) },
59 { "temp_errors", opt_stringptr, LOFF(temp_errors) },
60 { "timeout", opt_time, LOFF(timeout) },
61 { "timeout_defer", opt_bool, LOFF(timeout_defer) },
62 { "umask", opt_octint, LOFF(umask) },
63 { "use_bsmtp", opt_bool, LOFF(use_bsmtp) },
64 #ifdef HAVE_SETCLASSRESOURCES
65 { "use_classresources", opt_bool, LOFF(use_classresources) },
67 { "use_crlf", opt_bool, LOFF(use_crlf) },
68 { "use_shell", opt_bool, LOFF(use_shell) },
71 /* Size of the options list. An extern variable has to be used so that its
72 address can appear in the tables drtables.c. */
74 int pipe_transport_options_count =
75 sizeof(pipe_transport_options)/sizeof(optionlist);
81 pipe_transport_options_block pipe_transport_option_defaults = {0};
82 void pipe_transport_init(transport_instance *tblock) {}
83 BOOL pipe_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
85 #else /*!MACRO_PREDEF*/
88 /* Default private options block for the pipe transport. */
90 pipe_transport_options_block pipe_transport_option_defaults = {
91 .path = US"/bin:/usr/bin",
92 .temp_errors = US mac_expanded_string(EX_TEMPFAIL) ":"
93 mac_expanded_string(EX_CANTCREAT),
97 /* all others null/zero/false */
102 /*************************************************
103 * Setup entry point *
104 *************************************************/
106 /* Called for each delivery in the privileged state, just before the uid/gid
107 are changed and the main entry point is called. In a system that supports the
108 login_cap facilities, this function is used to set the class resource limits
109 for the user. It may also re-enable coredumps.
112 tblock points to the transport instance
113 addrlist addresses about to be delivered (not used)
114 dummy not used (doesn't pass back data)
115 uid the uid that will be set (not used)
116 gid the gid that will be set (not used)
117 errmsg where to put an error message
119 Returns: OK, FAIL, or DEFER
123 pipe_transport_setup(transport_instance *tblock, address_item *addrlist,
124 transport_feedback *dummy, uid_t uid, gid_t gid, uschar **errmsg)
126 pipe_transport_options_block *ob =
127 (pipe_transport_options_block *)(tblock->options_block);
129 #ifdef HAVE_SETCLASSRESOURCES
130 if (ob->use_classresources)
132 struct passwd *pw = getpwuid(uid);
135 login_cap_t *lc = login_getpwclass(pw);
138 setclassresources(lc);
146 if (ob->permit_coredump)
149 rl.rlim_cur = RLIM_INFINITY;
150 rl.rlim_max = RLIM_INFINITY;
151 if (setrlimit(RLIMIT_CORE, &rl) < 0)
153 #ifdef SETRLIMIT_NOT_SUPPORTED
154 if (errno != ENOSYS && errno != ENOTSUP)
156 log_write(0, LOG_MAIN,
157 "delivery setrlimit(RLIMIT_CORE, RLIM_INFINITY) failed: %s",
168 /*************************************************
169 * Initialization entry point *
170 *************************************************/
172 /* Called for each instance, after its options have been read, to
173 enable consistency checks to be done, or anything else that needs
177 pipe_transport_init(transport_instance *tblock)
179 pipe_transport_options_block *ob =
180 (pipe_transport_options_block *)(tblock->options_block);
182 /* Set up the setup entry point, to be called in the privileged state */
184 tblock->setup = pipe_transport_setup;
186 /* If pipe_as_creator is set, then uid/gid should not be set. */
188 if (tblock->deliver_as_creator && (tblock->uid_set || tblock->gid_set ||
189 tblock->expand_uid != NULL || tblock->expand_gid != NULL))
190 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
191 "both pipe_as_creator and an explicit uid/gid are set for the %s "
192 "transport", tblock->name);
194 /* If a fixed uid field is set, then a gid field must also be set. */
196 if (tblock->uid_set && !tblock->gid_set && tblock->expand_gid == NULL)
197 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
198 "user set without group for the %s transport", tblock->name);
200 /* Temp_errors must consist only of digits and colons, but there can be
201 spaces round the colons, so allow them too. */
203 if (ob->temp_errors != NULL && Ustrcmp(ob->temp_errors, "*") != 0)
205 size_t p = Ustrspn(ob->temp_errors, "0123456789: ");
206 if (ob->temp_errors[p] != 0)
207 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
208 "temp_errors must be a list of numbers or an asterisk for the %s "
209 "transport", tblock->name);
212 /* Only one of return_output/return_fail_output or log_output/log_fail_output
215 if (tblock->return_output && tblock->return_fail_output)
216 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
217 "both return_output and return_fail_output set for %s transport",
220 if (tblock->log_output && tblock->log_fail_output)
221 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
222 "both log_output and log_fail_output set for the %s transport",
225 /* If batch SMTP is set, force the check and escape strings, and arrange that
226 headers are also escaped. */
230 ob->check_string = US".";
231 ob->escape_string = US"..";
232 ob->options |= topt_escape_headers;
235 /* If not batch SMTP, and message_prefix or message_suffix are unset, insert
236 default values for them. */
240 if (ob->message_prefix == NULL) ob->message_prefix =
241 US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n";
242 if (ob->message_suffix == NULL) ob->message_suffix = US"\n";
245 /* The restrict_to_path and use_shell options are incompatible */
247 if (ob->restrict_to_path && ob->use_shell)
248 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
249 "both restrict_to_path and use_shell set for %s transport",
252 /* The allow_commands and use_shell options are incompatible */
254 if (ob->allow_commands && ob->use_shell)
255 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
256 "both allow_commands and use_shell set for %s transport",
259 /* Set up the bitwise options for transport_write_message from the various
260 driver options. Only one of body_only and headers_only can be set. */
263 (tblock->body_only ? topt_no_headers : 0)
264 | (tblock->headers_only ? topt_no_body : 0)
265 | (tblock->return_path_add ? topt_add_return_path : 0)
266 | (tblock->delivery_date_add ? topt_add_delivery_date : 0)
267 | (tblock->envelope_to_add ? topt_add_envelope_to : 0)
268 | (ob->use_crlf ? topt_use_crlf : 0);
273 /*************************************************
274 * Set up direct (non-shell) command *
275 *************************************************/
277 /* This function is called when a command line is to be parsed by the transport
278 and executed directly, without the use of /bin/sh.
281 argvptr pointer to anchor for argv vector
282 cmd points to the command string
283 expand_arguments true if expansion is to occur
284 expand_fail error if expansion fails
285 addr chain of addresses
286 tname the transport name
287 ob the transport options block
289 Returns: TRUE if all went well; otherwise an error will be
290 set in the first address and FALSE returned
294 set_up_direct_command(const uschar ***argvptr, uschar *cmd,
295 BOOL expand_arguments, int expand_fail, address_item *addr, uschar *tname,
296 pipe_transport_options_block *ob)
298 BOOL permitted = FALSE;
301 /* Set up "transport <name>" to be put in any error messages, and then
302 call the common function for creating an argument list and expanding
303 the items if necessary. If it fails, this function fails (error information
304 is in the addresses). */
306 if (!transport_set_up_command(argvptr, cmd, expand_arguments, expand_fail,
307 addr, string_sprintf("%.50s transport", tname), NULL))
310 /* Point to the set-up arguments. */
314 /* If allow_commands is set, see if the command is in the permitted list. */
316 if (ob->allow_commands)
322 if (!(s = expand_string(ob->allow_commands)))
324 addr->transport_return = DEFER;
325 addr->message = string_sprintf("failed to expand string \"%s\" "
326 "for %s transport: %s", ob->allow_commands, tname, expand_string_message);
330 while ((p = string_nextinlist(&s, &sep, NULL, 0)))
331 if (Ustrcmp(p, argv[0]) == 0) { permitted = TRUE; break; }
334 /* If permitted is TRUE it means the command was found in the allowed list, and
335 no further checks are done. If permitted = FALSE, it either means
336 allow_commands wasn't set, or that the command didn't match anything in the
337 list. In both cases, if restrict_to_path is set, we fail if the command
338 contains any slashes, but if restrict_to_path is not set, we must fail the
339 command only if allow_commands is set. */
343 if (ob->restrict_to_path)
345 if (Ustrchr(argv[0], '/') != NULL)
347 addr->transport_return = FAIL;
348 addr->message = string_sprintf("\"/\" found in \"%s\" (command for %s "
349 "transport) - failed for security reasons", cmd, tname);
354 else if (ob->allow_commands)
356 addr->transport_return = FAIL;
357 addr->message = string_sprintf("\"%s\" command not permitted by %s "
358 "transport", argv[0], tname);
363 /* If the command is not an absolute path, search the PATH directories
366 if (argv[0][0] != '/')
370 const uschar *listptr = expand_string(ob->path);
372 while ((p = string_nextinlist(&listptr, &sep, NULL, 0)))
375 sprintf(CS big_buffer, "%.256s/%.256s", p, argv[0]);
376 if (Ustat(big_buffer, &statbuf) == 0)
378 argv[0] = string_copy(big_buffer);
384 addr->transport_return = FAIL;
385 addr->message = string_sprintf("\"%s\" command not found for %s transport",
395 /*************************************************
396 * Set up shell command *
397 *************************************************/
399 /* This function is called when a command line is to be passed to /bin/sh
400 without parsing inside the transport.
403 argvptr pointer to anchor for argv vector
404 cmd points to the command string
405 expand_arguments true if expansion is to occur
406 expand_fail error if expansion fails
407 addr chain of addresses
408 tname the transport name
410 Returns: TRUE if all went well; otherwise an error will be
411 set in the first address and FALSE returned
415 set_up_shell_command(const uschar ***argvptr, uschar *cmd,
416 BOOL expand_arguments, int expand_fail, address_item *addr, uschar *tname)
420 *argvptr = argv = store_get((4)*sizeof(uschar *), GET_UNTAINTED);
422 argv[0] = US"/bin/sh";
425 /* We have to take special action to handle the special "variable" called
426 $pipe_addresses, which is not recognized by the normal expansion function. */
428 if (expand_arguments)
430 uschar * p = Ustrstr(cmd, "pipe_addresses");
434 debug_printf("shell pipe command before expansion:\n %s\n", cmd);
436 /* Allow $recipients in the expansion iff it comes from a system filter */
438 f.enable_dollar_recipients = addr && addr->parent &&
439 Ustrcmp(addr->parent->address, "system-filter") == 0;
442 (p > cmd && p[-1] == '$') ||
443 (p > cmd + 1 && p[-2] == '$' && p[-1] == '{' && p[14] == '}')))
447 if (p[-1] == '{') { q++; p--; }
449 g = string_get(Ustrlen(cmd) + 64);
450 g = string_catn(g, cmd, p - cmd - 1);
452 for (address_item * ad = addr; ad; ad = ad->next)
454 /*XXX string_append_listele() ? */
455 if (ad != addr) g = string_catn(g, US" ", 1);
456 g = string_cat(g, ad->address);
459 g = string_cat(g, q);
460 argv[2] = (cmd = string_from_gstring(g)) ? expand_string(cmd) : NULL;
463 argv[2] = expand_string(cmd);
465 f.enable_dollar_recipients = FALSE;
469 addr->transport_return = f.search_find_defer ? DEFER : expand_fail;
470 addr->message = string_sprintf("Expansion of command \"%s\" "
471 "in %s transport failed: %s",
472 cmd, tname, expand_string_message);
477 debug_printf("shell pipe command after expansion:\n %s\n", argv[2]);
482 debug_printf("shell pipe command (no expansion):\n %s\n", cmd);
493 /*************************************************
495 *************************************************/
497 /* See local README for interface details. This transport always returns FALSE,
498 indicating that the status in the first address is the status for all addresses
502 pipe_transport_entry(
503 transport_instance *tblock, /* data for this instantiation */
504 address_item *addr) /* address(es) we are working on */
507 int fd_in, fd_out, rc;
511 pipe_transport_options_block *ob =
512 (pipe_transport_options_block *)(tblock->options_block);
513 int timeout = ob->timeout;
514 BOOL written_ok = FALSE;
515 BOOL expand_arguments;
518 const uschar *envlist = ob->environment;
520 uschar *eol = ob->use_crlf ? US"\r\n" : US"\n";
521 transport_ctx tctx = {
524 .check_string = ob->check_string,
525 .escape_string = ob->escape_string,
526 ob->options | topt_not_socket /* set at initialization time */
529 DEBUG(D_transport) debug_printf("%s transport entered\n", tblock->name);
531 /* Set up for the good case */
533 addr->transport_return = OK;
534 addr->basic_errno = 0;
536 /* Pipes are not accepted as general addresses, but they can be generated from
537 .forward files or alias files. In those cases, the pfr flag is set, and the
538 command to be obeyed is pointed to by addr->local_part; it starts with the pipe
539 symbol. In other cases, the command is supplied as one of the pipe transport's
542 if (testflag(addr, af_pfr) && addr->local_part[0] == '|')
543 if (ob->force_command)
545 /* Enables expansion of $address_pipe into separate arguments */
546 setflag(addr, af_force_command);
548 expand_arguments = TRUE;
553 cmd = addr->local_part + 1;
554 while (isspace(*cmd)) cmd++;
555 expand_arguments = testflag(addr, af_expand_pipe);
561 expand_arguments = TRUE;
565 /* If no command has been supplied, we are in trouble.
566 We also check for an empty string since it may be
567 coming from addr->local_part[0] == '|' */
571 addr->transport_return = DEFER;
572 addr->message = string_sprintf("no command specified for %s transport",
578 addr->message = string_sprintf("Tainted '%s' (command "
579 "for %s transport) not permitted", cmd, tblock->name);
580 addr->transport_return = PANIC;
584 /* When a pipe is set up by a filter file, there may be values for $thisaddress
585 and numerical the variables in existence. These are passed in
586 addr->pipe_expandn for use here. */
588 if (expand_arguments && addr->pipe_expandn)
590 uschar **ss = addr->pipe_expandn;
592 if (*ss) filter_thisaddress = *ss++;
595 expand_nstring[++expand_nmax] = *ss;
596 expand_nlength[expand_nmax] = Ustrlen(*ss++);
600 /* The default way of processing the command is to split it up into arguments
601 here, and run it directly. This offers some security advantages. However, there
602 are installations that want by default to run commands under /bin/sh always, so
603 there is an option to do that. */
607 if (!set_up_shell_command(&argv, cmd, expand_arguments, expand_fail, addr,
608 tblock->name)) return FALSE;
610 else if (!set_up_direct_command(&argv, cmd, expand_arguments, expand_fail, addr,
611 tblock->name, ob)) return FALSE;
613 expand_nmax = -1; /* Reset */
614 filter_thisaddress = NULL;
616 /* Set up the environment for the command. */
618 envp[envcount++] = string_sprintf("LOCAL_PART=%s", deliver_localpart);
619 envp[envcount++] = string_sprintf("LOGNAME=%s", deliver_localpart);
620 envp[envcount++] = string_sprintf("USER=%s", deliver_localpart);
621 envp[envcount++] = string_sprintf("LOCAL_PART_PREFIX=%#s",
622 deliver_localpart_prefix);
623 envp[envcount++] = string_sprintf("LOCAL_PART_SUFFIX=%#s",
624 deliver_localpart_suffix);
625 envp[envcount++] = string_sprintf("DOMAIN=%s", deliver_domain);
626 envp[envcount++] = string_sprintf("HOME=%#s", deliver_home);
627 envp[envcount++] = string_sprintf("MESSAGE_ID=%s", message_id);
628 envp[envcount++] = string_sprintf("PATH=%s", expand_string(ob->path));
629 envp[envcount++] = string_sprintf("RECIPIENT=%#s%#s%#s@%#s",
630 deliver_localpart_prefix, deliver_localpart, deliver_localpart_suffix,
632 envp[envcount++] = string_sprintf("QUALIFY_DOMAIN=%s", qualify_domain_sender);
633 envp[envcount++] = string_sprintf("SENDER=%s", sender_address);
634 envp[envcount++] = US"SHELL=/bin/sh";
637 envp[envcount++] = string_sprintf("HOST=%s", addr->host_list->name);
639 if (f.timestamps_utc)
640 envp[envcount++] = US"TZ=UTC";
641 else if (timezone_string && timezone_string[0])
642 envp[envcount++] = string_sprintf("TZ=%s", timezone_string);
644 /* Add any requested items */
647 if (!(envlist = expand_cstring(envlist)))
649 addr->transport_return = DEFER;
650 addr->message = string_sprintf("failed to expand string \"%s\" "
651 "for %s transport: %s", ob->environment, tblock->name,
652 expand_string_message);
656 while ((ss = string_nextinlist(&envlist, &envsep, NULL, 0)))
658 if (envcount > nelem(envp) - 2)
660 addr->transport_return = DEFER;
661 addr->basic_errno = E2BIG;
662 addr->message = string_sprintf("too many environment settings for "
663 "%s transport", tblock->name);
666 envp[envcount++] = string_copy(ss);
669 envp[envcount] = NULL;
671 /* If the -N option is set, can't do any more. */
676 debug_printf("*** delivery by %s transport bypassed by -N option",
682 /* Handling the output from the pipe is tricky. If a file for catching this
683 output is provided, we could in theory just hand that fd over to the process,
684 but this isn't very safe because it might loop and carry on writing for
685 ever (which is exactly what happened in early versions of Exim). Therefore we
686 use the standard child_open() function, which creates pipes. We can then read
687 our end of the output pipe and count the number of bytes that come through,
688 chopping the sub-process if it exceeds some limit.
690 However, this means we want to run a sub-process with both its input and output
691 attached to pipes. We can't handle that easily from a single parent process
692 using straightforward code such as the transport_write_message() function
693 because the subprocess might not be reading its input because it is trying to
694 write to a full output pipe. The complication of redesigning the world to
695 handle this is too great - simpler just to run another process to do the
696 reading of the output pipe. */
699 /* As this is a local transport, we are already running with the required
700 uid/gid and current directory. Request that the new process be a process group
701 leader, so we can kill it and all its children on a timeout. */
703 if ((pid = child_open(USS argv, envp, ob->umask, &fd_in, &fd_out, TRUE,
704 US"pipe-tpt-cmd")) < 0)
706 addr->transport_return = DEFER;
707 addr->message = string_sprintf(
708 "Failed to create child process for %s transport: %s", tblock->name,
714 /* Now fork a process to handle the output that comes down the pipe. */
716 if ((outpid = exim_fork(US"pipe-tpt-output")) < 0)
718 addr->basic_errno = errno;
719 addr->transport_return = DEFER;
720 addr->message = string_sprintf(
721 "Failed to create process for handling output in %s transport",
728 /* This is the code for the output-handling subprocess. Read from the pipe
729 in chunks, and write to the return file if one is provided. Keep track of
730 the number of bytes handled. If the limit is exceeded, try to kill the
731 subprocess group, and in any case close the pipe and exit, which should cause
732 the subprocess to fail. */
738 set_process_info("reading output from |%s", cmd);
739 while ((rc = read(fd_out, big_buffer, big_buffer_size)) > 0)
741 if (addr->return_file >= 0)
742 if(write(addr->return_file, big_buffer, rc) != rc)
743 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
745 if (count > ob->max_output)
747 DEBUG(D_transport) debug_printf("Too much output from pipe - killed\n");
748 if (addr->return_file >= 0)
750 uschar *message = US"\n\n*** Too much output - remainder discarded ***\n";
751 rc = Ustrlen(message);
752 if(write(addr->return_file, message, rc) != rc)
753 DEBUG(D_transport) debug_printf("Problem writing to return_file\n");
755 killpg(pid, SIGKILL);
763 (void)close(fd_out); /* Not used in this process */
766 /* Carrying on now with the main parent process. Attempt to write the message
767 to it down the pipe. It is a fallacy to think that you can detect write errors
768 when the sub-process fails to read the pipe. The parent process may complete
769 writing and close the pipe before the sub-process completes. We could sleep a
770 bit here to let the sub-process get going, but it may still not complete. So we
771 ignore all writing errors. (When in the test harness, we do do a short sleep so
772 any debugging output is likely to be in the same order.) */
774 testharness_pause_ms(500);
776 DEBUG(D_transport) debug_printf("Writing message to pipe\n");
778 /* Arrange to time out writes if there is a timeout set. */
782 sigalrm_seen = FALSE;
783 transport_write_timeout = timeout;
786 /* Reset the counter of bytes written */
790 /* First write any configured prefix information */
792 if (ob->message_prefix)
794 uschar *prefix = expand_string(ob->message_prefix);
797 addr->transport_return = f.search_find_defer? DEFER : PANIC;
798 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
799 "transport) failed: %s", ob->message_prefix, tblock->name,
800 expand_string_message);
803 if (!transport_write_block(&tctx, prefix, Ustrlen(prefix), FALSE))
807 /* If the use_bsmtp option is set, we need to write SMTP prefix information.
808 The various different values for batching are handled outside; if there is more
809 than one address available here, all must be included. Force SMTP dot-handling.
814 if (!transport_write_string(fd_in, "MAIL FROM:<%s>%s", return_path, eol))
817 for (address_item * a = addr; a; a = a->next)
818 if (!transport_write_string(fd_in,
820 transport_rcpt_address(a, tblock->rcpt_include_affixes),
824 if (!transport_write_string(fd_in, "DATA%s", eol)) goto END_WRITE;
827 /* Now the actual message */
829 if (!transport_write_message(&tctx, 0))
832 /* Now any configured suffix */
834 if (ob->message_suffix)
836 uschar *suffix = expand_string(ob->message_suffix);
839 addr->transport_return = f.search_find_defer? DEFER : PANIC;
840 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
841 "transport) failed: %s", ob->message_suffix, tblock->name,
842 expand_string_message);
845 if (!transport_write_block(&tctx, suffix, Ustrlen(suffix), FALSE))
849 /* If local_smtp, write the terminating dot. */
851 if (ob->use_bsmtp && !transport_write_string(fd_in, ".%s", eol))
854 /* Flag all writing completed successfully. */
858 /* Come here if there are errors during writing. */
862 /* OK, the writing is now all done. Close the pipe. */
866 /* Handle errors during writing. For timeouts, set the timeout for waiting for
867 the child process to 1 second. If the process at the far end of the pipe died
868 without reading all of it, we expect an EPIPE error, which should be ignored.
869 We used also to ignore WRITEINCOMPLETE but the writing function is now cleverer
870 at handling OS where the death of a pipe doesn't give EPIPE immediately. See
875 if (errno == ETIMEDOUT)
877 addr->message = string_sprintf("%stimeout while writing to pipe",
878 f.transport_filter_timed_out ? "transport filter " : "");
879 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
882 else if (errno == EPIPE)
884 debug_printf("transport error EPIPE ignored\n");
888 addr->transport_return = PANIC;
889 addr->basic_errno = errno;
890 if (errno == ERRNO_CHHEADER_FAIL)
892 string_sprintf("Failed to expand headers_add or headers_remove: %s",
893 expand_string_message);
894 else if (errno == ERRNO_FILTER_FAIL)
895 addr->message = string_sprintf("Transport filter process failed (%d)%s",
897 (addr->more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
898 else if (errno == ERRNO_WRITEINCOMPLETE)
899 addr->message = US"Failed repeatedly to write data";
901 addr->message = string_sprintf("Error %d", errno);
906 /* Wait for the child process to complete and take action if the returned
907 status is nonzero. The timeout will be just 1 second if any of the writes
910 if ((rc = child_close(pid, timeout)) != 0)
912 uschar * tmsg = addr->message
913 ? string_sprintf(" (preceded by %s)", addr->message) : US"";
915 /* The process did not complete in time; kill its process group and fail
916 the delivery. It appears to be necessary to kill the output process too, as
917 otherwise it hangs on for some time if the actual pipe process is sleeping.
918 (At least, that's what I observed on Solaris 2.5.1.) Since we are failing
919 the delivery, that shouldn't cause any problem. */
923 killpg(pid, SIGKILL);
924 kill(outpid, SIGKILL);
925 addr->transport_return = ob->timeout_defer? DEFER : FAIL;
926 addr->message = string_sprintf("pipe delivery process timed out%s", tmsg);
933 addr->transport_return = PANIC;
934 addr->message = string_sprintf("Wait() failed for child process of %s "
935 "transport: %s%s", tblock->name, strerror(errno), tmsg);
938 /* Since the transport_filter timed out we assume it has sent the child process
939 a malformed or incomplete data stream. Kill off the child process
940 and prevent checking its exit status as it will has probably exited in error.
941 This prevents the transport_filter timeout message from getting overwritten
942 by the exit error which is not the cause of the problem. */
944 else if (f.transport_filter_timed_out)
946 killpg(pid, SIGKILL);
947 kill(outpid, SIGKILL);
950 /* Either the process completed, but yielded a non-zero (necessarily
951 positive) status, or the process was terminated by a signal (rc will contain
952 the negation of the signal number). Treat killing by signal as failure unless
953 status is being ignored. By default, the message is bounced back, unless
954 freeze_signal is set, in which case it is frozen instead. */
958 if (ob->freeze_signal)
960 addr->transport_return = DEFER;
961 addr->special_action = SPECIAL_FREEZE;
962 addr->message = string_sprintf("Child process of %s transport (running "
963 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
964 -rc, os_strsignal(-rc), tmsg);
966 else if (!ob->ignore_status)
968 addr->transport_return = FAIL;
969 addr->message = string_sprintf("Child process of %s transport (running "
970 "command \"%s\") was terminated by signal %d (%s)%s", tblock->name, cmd,
971 -rc, os_strsignal(-rc), tmsg);
975 /* For positive values (process terminated with non-zero status), we need a
976 status code to request deferral. A number of systems contain the following
979 #define EX_TEMPFAIL 75
983 EX_TEMPFAIL -- temporary failure, indicating something that
984 is not really an error. In sendmail, this means
985 that a mailer (e.g.) could not create a connection,
986 and the request should be reattempted later.
988 Based on this, we use exit code EX_TEMPFAIL as a default to mean "defer" when
989 not ignoring the returned status. However, there is now an option that
990 contains a list of temporary codes, with TEMPFAIL and CANTCREAT as defaults.
992 Another case that needs special treatment is if execve() failed (typically
993 the command that was given is a non-existent path). By default this is
994 treated as just another failure, but if freeze_exec_fail is set, the reaction
995 is to freeze the message rather than bounce the address. Exim used to signal
996 this failure with EX_UNAVAILABLE, which is defined in many systems as
998 #define EX_UNAVAILABLE 69
1000 with the description
1002 EX_UNAVAILABLE -- A service is unavailable. This can occur
1003 if a support program or file does not exist. This
1004 can also be used as a catchall message when something
1005 you wanted to do doesn't work, but you don't know why.
1007 However, this can be confused with a command that actually returns 69 because
1008 something *it* wanted is unavailable. At release 4.21, Exim was changed to
1009 use return code 127 instead, because this is what the shell returns when it
1010 is unable to exec a command. We define it as EX_EXECFAILED, and use it in
1011 child.c to signal execve() failure and other unexpected failures such as
1012 setuid() not working - though that won't be the case here because we aren't
1017 /* Always handle execve() failure specially if requested to */
1019 if (ob->freeze_exec_fail && rc == EX_EXECFAILED)
1021 addr->transport_return = DEFER;
1022 addr->special_action = SPECIAL_FREEZE;
1023 addr->message = string_sprintf("pipe process failed to exec \"%s\"%s",
1027 /* Otherwise take action only if not ignoring status */
1029 else if (!ob->ignore_status)
1034 /* If temp_errors is "*" all codes are temporary. Initialization checks
1035 that it's either "*" or a list of numbers. If not "*", scan the list of
1036 temporary failure codes; if any match, the result is DEFER. */
1038 if (ob->temp_errors[0] == '*')
1039 addr->transport_return = DEFER;
1043 const uschar *s = ob->temp_errors;
1047 addr->transport_return = FAIL;
1048 while ((p = string_nextinlist(&s,&sep,NULL,0)))
1049 if (rc == Uatoi(p)) { addr->transport_return = DEFER; break; }
1052 /* Ensure the message contains the expanded command and arguments. This
1053 doesn't have to be brilliantly efficient - it is an error situation. */
1055 addr->message = string_sprintf("Child process of %s transport returned "
1056 "%d", tblock->name, rc);
1057 g = string_cat(NULL, addr->message);
1059 /* If the return code is > 128, it often means that a shell command
1060 was terminated by a signal. */
1063 string_sprintf("(could mean shell command ended by signal %d (%s))",
1064 rc-128, os_strsignal(rc-128)) :
1069 g = string_catn(g, US" ", 1);
1070 g = string_cat (g, ss);
1073 /* Now add the command and arguments */
1075 g = string_catn(g, US" from command:", 14);
1077 for (int i = 0; i < sizeof(argv)/sizeof(int *) && argv[i] != NULL; i++)
1080 g = string_catn(g, US" ", 1);
1081 if (Ustrpbrk(argv[i], " \t") != NULL)
1084 g = string_catn(g, US"\"", 1);
1086 g = string_cat(g, argv[i]);
1088 g = string_catn(g, US"\"", 1);
1091 /* Add previous filter timeout message, if present. */
1094 g = string_cat(g, tmsg);
1096 addr->message = string_from_gstring(g);
1101 /* Ensure all subprocesses (in particular, the output handling process)
1102 are complete before we pass this point. */
1104 while (wait(&rc) >= 0);
1106 DEBUG(D_transport) debug_printf("%s transport yielded %d\n", tblock->name,
1107 addr->transport_return);
1109 /* If there has been a problem, the message in addr->message contains details
1110 of the pipe command. We don't want to expose these to the world, so we set up
1111 something bland to return to the sender. */
1113 if (addr->transport_return != OK)
1114 addr->user_message = US"local delivery failed";
1119 #endif /*!MACRO_PREDEF*/
1120 /* End of transport/pipe.c */