1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim Maintainers 2020 - 2024 */
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 */
12 #ifdef ROUTER_QUERYPROGRAM /* Remainder of file */
13 #include "rf_functions.h"
14 #include "queryprogram.h"
18 /* Options specific to the queryprogram router. */
20 optionlist queryprogram_router_options[] = {
21 { "*expand_command_group", opt_bool | opt_hidden,
22 OPT_OFF(queryprogram_router_options_block, expand_cmd_gid) },
23 { "*expand_command_user", opt_bool | opt_hidden,
24 OPT_OFF(queryprogram_router_options_block, expand_cmd_uid) },
25 { "*set_command_group", opt_bool | opt_hidden,
26 OPT_OFF(queryprogram_router_options_block, cmd_gid_set) },
27 { "*set_command_user", opt_bool | opt_hidden,
28 OPT_OFF(queryprogram_router_options_block, cmd_uid_set) },
29 { "command", opt_stringptr,
30 OPT_OFF(queryprogram_router_options_block, command) },
31 { "command_group",opt_expand_gid,
32 OPT_OFF(queryprogram_router_options_block, cmd_gid) },
33 { "command_user", opt_expand_uid,
34 OPT_OFF(queryprogram_router_options_block, cmd_uid) },
35 { "current_directory", opt_stringptr,
36 OPT_OFF(queryprogram_router_options_block, current_directory) },
37 { "timeout", opt_time,
38 OPT_OFF(queryprogram_router_options_block, timeout) }
41 /* Size of the options list. An extern variable has to be used so that its
42 address can appear in the tables drtables.c. */
44 int queryprogram_router_options_count =
45 sizeof(queryprogram_router_options)/sizeof(optionlist);
51 queryprogram_router_options_block queryprogram_router_option_defaults = {0};
52 void queryprogram_router_init(router_instance *rblock) {}
53 int queryprogram_router_entry(router_instance *rblock, address_item *addr,
54 struct passwd *pw, int verify, address_item **addr_local,
55 address_item **addr_remote, address_item **addr_new,
56 address_item **addr_succeed) {return 0;}
58 #else /*!MACRO_PREDEF*/
61 /* Default private options block for the queryprogram router. */
63 queryprogram_router_options_block queryprogram_router_option_defaults = {
66 (uid_t)(-1), /* cmd_uid */
67 (gid_t)(-1), /* cmd_gid */
68 FALSE, /* cmd_uid_set */
69 FALSE, /* cmd_gid_set */
70 US"/", /* current_directory */
71 NULL, /* expand_cmd_gid */
72 NULL /* expand_cmd_uid */
77 /*************************************************
78 * Initialization entry point *
79 *************************************************/
81 /* Called for each instance, after its options have been read, to enable
82 consistency checks to be done, or anything else that needs to be set up. */
85 queryprogram_router_init(router_instance *rblock)
87 queryprogram_router_options_block *ob =
88 (queryprogram_router_options_block *)(rblock->options_block);
90 /* A command must be given */
93 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
94 "a command specification is required", rblock->name);
96 /* A uid/gid must be supplied */
98 if (!ob->cmd_uid_set && !ob->expand_cmd_uid)
99 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n "
100 "command_user must be specified", rblock->name);
105 /*************************************************
106 * Process a set of generated new addresses *
107 *************************************************/
109 /* This function sets up a set of newly generated child addresses and puts them
110 on the new address chain.
114 addr_new new address chain
115 addr original address
116 generated list of generated addresses
117 addr_prop the propagated data block, containing errors_to,
118 header change stuff, and address_data
124 add_generated(router_instance *rblock, address_item **addr_new,
125 address_item *addr, address_item *generated,
126 address_item_propagated *addr_prop)
128 while (generated != NULL)
130 BOOL ignore_error = addr->prop.ignore_error;
131 address_item *next = generated;
133 generated = next->next;
136 next->prop = *addr_prop;
137 next->prop.ignore_error = next->prop.ignore_error || ignore_error;
138 next->start_router = rblock->redirect_router;
140 next->next = *addr_new;
143 if (addr->child_count == USHRT_MAX)
144 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
145 "child addresses for <%s>", rblock->name, USHRT_MAX, addr->address);
149 debug_printf("%s router generated %s\n", rblock->name, next->address);
156 /*************************************************
158 *************************************************/
160 /* See local README for interface details. This router returns:
168 . timeout of host lookup and pass_on_timeout set
172 . verifying the errors address caused a deferment or a big disaster such
173 as an expansion failure (rf_get_errors_address)
174 . expanding a headers_{add,remove} string caused a deferment or another
175 expansion error (rf_get_munge_headers)
176 . a problem in rf_get_transport: no transport when one is needed;
177 failed to expand dynamic transport; failed to find dynamic transport
179 . problem looking up host (rf_lookup_hostlist)
180 . self = DEFER or FREEZE
181 . failure to set up uid/gid for running the command
182 . failure of transport_set_up_command: too many arguments, expansion fail
183 . failure to create child process
184 . child process crashed or timed out or didn't return data
186 . DEFER or FREEZE returned
187 . problem in redirection data
188 . unknown transport name or trouble expanding router transport
196 . address added to addr_local or addr_remote for delivery
197 . new addresses added to addr_new
201 queryprogram_router_entry(
202 router_instance *rblock, /* data for this instantiation */
203 address_item *addr, /* address we are working on */
204 struct passwd *pw, /* passwd entry after check_local_user */
205 int verify, /* v_none/v_recipient/v_sender/v_expn */
206 address_item **addr_local, /* add it to this if it's local */
207 address_item **addr_remote, /* add it to this if it's remote */
208 address_item **addr_new, /* put new addresses on here */
209 address_item **addr_succeed) /* put old address here on success */
211 int fd_in, fd_out, len, rc;
213 struct passwd *upw = NULL;
215 const uschar **argvptr;
216 uschar *rword, *rdata, *s;
217 address_item_propagated addr_prop;
218 queryprogram_router_options_block *ob =
219 (queryprogram_router_options_block *)(rblock->options_block);
220 uschar *current_directory = ob->current_directory;
222 uid_t curr_uid = getuid();
223 gid_t curr_gid = getgid();
224 uid_t uid = ob->cmd_uid;
225 gid_t gid = ob->cmd_gid;
229 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
230 rblock->name, addr->address, addr->domain);
232 ugid.uid_set = ugid.gid_set = FALSE;
234 /* Set up the propagated data block with the current address_data and the
235 errors address and extra header stuff. */
237 bzero(&addr_prop, sizeof(addr_prop));
238 addr_prop.address_data = deliver_address_data;
239 tree_dup((tree_node **)&addr_prop.variables, addr->prop.variables);
241 rc = rf_get_errors_address(addr, rblock, verify, &addr_prop.errors_address);
242 if (rc != OK) return rc;
244 rc = rf_get_munge_headers(addr, rblock, &addr_prop.extra_headers,
245 &addr_prop.remove_headers);
246 if (rc != OK) return rc;
248 /* Get the fixed or expanded uid under which the command is to run
249 (initialization ensures that one or the other is set). */
251 if ( !ob->cmd_uid_set
252 && !route_find_expanded_user(ob->expand_cmd_uid, rblock->name, US"router",
253 &upw, &uid, &(addr->message)))
256 /* Get the fixed or expanded gid, or take the gid from the passwd entry. */
258 if (!ob->cmd_gid_set)
259 if (ob->expand_cmd_gid)
261 if (route_find_expanded_group(ob->expand_cmd_gid, rblock->name,
262 US"router", &gid, &(addr->message)))
269 addr->message = string_sprintf("command_user set without command_group "
270 "for %s router", rblock->name);
274 DEBUG(D_route) debug_printf("requires uid=%ld gid=%ld current_directory=%s\n",
275 (long int)uid, (long int)gid, current_directory);
277 /* If we are not running as root, we will not be able to change uid/gid. */
279 if (curr_uid != root_uid && (uid != curr_uid || gid != curr_gid))
283 debug_printf("not running as root: cannot change uid/gid\n");
284 debug_printf("subprocess will run with uid=%ld gid=%ld\n",
285 (long int)curr_uid, (long int)curr_gid);
290 /* Set up the command to run */
292 GET_OPTION("command");
293 if (!transport_set_up_command(&argvptr, /* anchor for arg list */
294 ob->command, /* raw command */
295 TSUC_EXPAND_ARGS, /* arguments expanded but must not be tainted */
296 0, /* not relevant when... */
297 NULL, /* no transporting address */
298 US"queryprogram router", /* for error messages */
299 &addr->message)) /* where to put error message */
302 /* Create the child process, making it a group leader. */
304 if ((pid = child_open_uid(argvptr, NULL, 0077, puid, pgid, &fd_in, &fd_out,
305 current_directory, TRUE, US"queryprogram-cmd")) < 0)
307 addr->message = string_sprintf("%s router couldn't create child process: %s",
308 rblock->name, strerror(errno));
312 /* Nothing is written to the standard input. */
316 /* Wait for the process to finish, applying the timeout, and inspect its return
319 if ((rc = child_close(pid, ob->timeout)) != 0)
322 addr->message = string_sprintf("%s router: command returned non-zero "
323 "code %d", rblock->name, rc);
327 addr->message = string_sprintf("%s router: command timed out",
329 killpg(pid, SIGKILL); /* Kill the whole process group */
333 addr->message = string_sprintf("%s router: wait() failed: %s",
334 rblock->name, strerror(errno));
337 addr->message = string_sprintf("%s router: command killed by signal %d",
343 /* Read the pipe to get the command's output, and then close it. */
345 len = read(fd_out, buffer, sizeof(buffer) - 1);
348 /* Failure to return any data is an error. */
352 addr->message = string_sprintf("%s router: command failed to return data",
357 /* Get rid of leading and trailing white space, and pick off the first word of
360 while (len > 0 && isspace(buffer[len-1])) len--;
363 DEBUG(D_route) debug_printf("command wrote: %s\n", buffer);
366 Uskip_whitespace(&rword);
368 Uskip_nonwhite(&rdata);
369 if (*rdata) *rdata++ = '\0';
371 /* The word must be a known yield name. If it is "REDIRECT", the rest of the
372 line is redirection data, as for a .forward file. It may not contain filter
373 data, and it may not contain anything other than addresses (no files, no pipes,
376 if (strcmpic(rword, US"REDIRECT") == 0)
379 redirect_block redirect;
380 address_item *generated = NULL;
382 redirect.string = rdata;
383 redirect.isfile = FALSE;
385 rc = rda_interpret(&redirect, /* redirection data */
386 RDO_BLACKHOLE | /* forbid :blackhole: */
387 RDO_FAIL | /* forbid :fail: */
388 RDO_INCLUDE | /* forbid :include: */
389 RDO_REWRITE, /* rewrite generated addresses */
390 NULL, /* :include: directory not relevant */
391 NULL, /* sieve vacation directory not relevant */
392 NULL, /* sieve enotify mailto owner not relevant */
393 NULL, /* sieve useraddress not relevant */
394 NULL, /* sieve subaddress not relevant */
395 &ugid, /* uid/gid (but not set) */
396 &generated, /* where to hang the results */
397 &addr->message, /* where to put messages */
398 NULL, /* don't skip syntax errors */
399 &filtertype, /* not used; will always be FILTER_FORWARD */
400 string_sprintf("%s router", rblock->name));
404 /* FF_DEFER and FF_FAIL can arise only as a result of explicit commands.
405 If a configured message was supplied, allow it to be included in an SMTP
406 response after verifying. */
409 if (!addr->message) addr->message = US"forced defer";
410 else addr->user_message = addr->message;
414 add_generated(rblock, addr_new, addr, generated, &addr_prop);
415 if (!addr->message) addr->message = US"forced rejection";
416 else addr->user_message = addr->message;
422 case FF_NOTDELIVERED: /* an empty redirection list is bad */
423 addr->message = US"no addresses supplied";
428 addr->basic_errno = ERRNO_BADREDIRECT;
429 addr->message = string_sprintf("error in redirect data: %s", addr->message);
433 /* Handle the generated addresses, if any. */
435 add_generated(rblock, addr_new, addr, generated, &addr_prop);
437 /* Put the original address onto the succeed queue so that any retry items
438 that get attached to it get processed. */
440 addr->next = *addr_succeed;
441 *addr_succeed = addr;
446 /* Handle other returns that are not ACCEPT */
448 if (strcmpic(rword, US"accept") != 0)
450 if (strcmpic(rword, US"decline") == 0) return DECLINE;
451 if (strcmpic(rword, US"pass") == 0) return PASS;
452 addr->message = string_copy(rdata); /* data is a message */
453 if (strcmpic(rword, US"fail") == 0)
455 setflag(addr, af_pass_message);
458 if (strcmpic(rword, US"freeze") == 0) addr->special_action = SPECIAL_FREEZE;
459 else if (strcmpic(rword, US"defer") != 0)
461 addr->message = string_sprintf("bad command yield: %s %s", rword, rdata);
462 log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
467 /* The command yielded "ACCEPT". The rest of the string is a number of keyed
468 fields from which we can fish out values using the equivalent of the "extract"
469 expansion function. */
471 if ((s = expand_getkeyed(US"data", rdata)) && *s)
472 addr_prop.address_data = string_copy(s);
474 /* If we found a transport name, find the actual transport */
476 if ((s = expand_getkeyed(US"transport", rdata)) && *s)
478 transport_instance *transport;
479 for (transport = transports; transport; transport = transport->next)
480 if (Ustrcmp(transport->name, s) == 0) break;
483 addr->message = string_sprintf("unknown transport name %s yielded by "
485 log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
488 addr->transport = transport;
491 /* No transport given; get the transport from the router configuration. It may
492 be fixed or expanded, but there will be an error if it is unset, requested by
493 the last argument not being NULL. */
497 if (!rf_get_transport(rblock->transport_name, &rblock->transport, addr,
498 rblock->name, US"transport"))
500 addr->transport = rblock->transport;
503 /* See if a host list is given, and if so, look up the addresses. */
505 if ((s = expand_getkeyed(US"hosts", rdata)) && *s)
507 int lookup_type = LK_DEFAULT;
508 uschar * ss = expand_getkeyed(US"lookup", rdata);
512 if (Ustrcmp(ss, "byname") == 0) lookup_type = LK_BYNAME;
513 else if (Ustrcmp(ss, "bydns") == 0) lookup_type = LK_BYDNS;
516 addr->message = string_sprintf("bad lookup type \"%s\" yielded by "
518 log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
523 host_build_hostlist(&(addr->host_list), s, FALSE); /* pro tem no randomize */
525 rc = rf_lookup_hostlist(rblock, addr, rblock->ignore_target_hosts,
526 lookup_type, hff_defer, addr_new);
527 if (rc != OK) return rc;
531 /* Put the errors address, extra headers, and address_data into this address */
533 addr->prop = addr_prop;
535 /* Queue the address for local or remote delivery. */
537 return rf_queue_add(addr, addr_local, addr_remote, rblock, pw) ? OK : DEFER;
540 #endif /*!MACRO_PREDEF*/
541 #endif /*ROUTER_QUERYPROGRAM*/
542 /* End of routers/queryprogram.c */