src/src/routers/queryprogram.c

   1 /* $Cambridge: exim/src/src/routers/queryprogram.c,v 1.3 2005/04/06 14:40:24 ph10 Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2005 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10 #include "../exim.h"
  11 #include "rf_functions.h"
  12 #include "queryprogram.h"
  13
  14
  15
  16 /* Options specific to the queryprogram router. */
  17
  18 optionlist queryprogram_router_options[] = {
  19   { "*expand_command_group", opt_bool | opt_hidden,
  20       (void *)(offsetof(queryprogram_router_options_block, expand_cmd_gid)) },
  21   { "*expand_command_user", opt_bool | opt_hidden,
  22       (void *)(offsetof(queryprogram_router_options_block, expand_cmd_uid)) },
  23   { "*set_command_group",   opt_bool | opt_hidden,
  24       (void *)(offsetof(queryprogram_router_options_block, cmd_gid_set)) },
  25   { "*set_command_user",    opt_bool | opt_hidden,
  26       (void *)(offsetof(queryprogram_router_options_block, cmd_uid_set)) },
  27   { "command",      opt_stringptr,
  28       (void *)(offsetof(queryprogram_router_options_block, command)) },
  29   { "command_group",opt_expand_gid,
  30       (void *)(offsetof(queryprogram_router_options_block, cmd_gid)) },
  31   { "command_user", opt_expand_uid,
  32       (void *)(offsetof(queryprogram_router_options_block, cmd_uid)) },
  33   { "current_directory", opt_stringptr,
  34       (void *)(offsetof(queryprogram_router_options_block, current_directory)) },
  35   { "timeout",      opt_time,
  36       (void *)(offsetof(queryprogram_router_options_block, timeout)) }
  37 };
  38
  39 /* Size of the options list. An extern variable has to be used so that its
  40 address can appear in the tables drtables.c. */
  41
  42 int queryprogram_router_options_count =
  43   sizeof(queryprogram_router_options)/sizeof(optionlist);
  44
  45 /* Default private options block for the queryprogram router. */
  46
  47 queryprogram_router_options_block queryprogram_router_option_defaults = {
  48   NULL,         /* command */
  49   60*60,        /* timeout */
  50   (uid_t)(-1),  /* cmd_uid */
  51   (gid_t)(-1),  /* cmd_gid */
  52   FALSE,        /* cmd_uid_set */
  53   FALSE,        /* cmd_gid_set */
  54   US"/",        /* current_directory */
  55   NULL,         /* expand_cmd_gid */
  56   NULL          /* expand_cmd_uid */
  57 };
  58
  59
  60
  61 /*************************************************
  62 *          Initialization entry point            *
  63 *************************************************/
  64
  65 /* Called for each instance, after its options have been read, to enable
  66 consistency checks to be done, or anything else that needs to be set up. */
  67
  68 void
  69 queryprogram_router_init(router_instance *rblock)
  70 {
  71 queryprogram_router_options_block *ob =
  72   (queryprogram_router_options_block *)(rblock->options_block);
  73
  74 /* A command must be given */
  75
  76 if (ob->command == NULL)
  77   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  78     "a command specification is required", rblock->name);
  79
  80 /* A uid/gid must be supplied */
  81
  82 if (!ob->cmd_uid_set && ob->expand_cmd_uid == NULL)
  83   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  84     "command_user must be specified", rblock->name);
  85 }
  86
  87
  88
  89 /*************************************************
  90 *    Process a set of generated new addresses    *
  91 *************************************************/
  92
  93 /* This function sets up a set of newly generated child addresses and puts them
  94 on the new address chain.
  95
  96 Arguments:
  97   rblock                  router block
  98   addr_new                new address chain
  99   addr                    original address
 100   generated               list of generated addresses
 101   addr_prop               the propagated data block, containing errors_to,
 102                             header change stuff, and address_data
 103
 104 Returns:         nothing
 105 */
 106
 107 static void
 108 add_generated(router_instance *rblock, address_item **addr_new,
 109   address_item *addr, address_item *generated,
 110   address_item_propagated *addr_prop)
 111 {
 112 while (generated != NULL)
 113   {
 114   address_item *next = generated;
 115   generated = next->next;
 116
 117   next->parent = addr;
 118   orflag(next, addr, af_propagate);
 119   next->p = *addr_prop;
 120   next->start_router = rblock->redirect_router;
 121
 122   next->next = *addr_new;
 123   *addr_new = next;
 124
 125   addr->child_count++;
 126
 127   DEBUG(D_route)
 128     debug_printf("%s router generated %s\n", rblock->name, next->address);
 129   }
 130 }
 131
 132
 133
 134
 135 /*************************************************
 136 *              Main entry point                  *
 137 *************************************************/
 138
 139 /* See local README for interface details. This router returns:
 140
 141 DECLINE
 142   . DECLINE returned
 143   . self = DECLINE
 144
 145 PASS
 146   . PASS returned
 147   . timeout of host lookup and pass_on_timeout set
 148   . self = PASS
 149
 150 DEFER
 151   . verifying the errors address caused a deferment or a big disaster such
 152       as an expansion failure (rf_get_errors_address)
 153   . expanding a headers_{add,remove} string caused a deferment or another
 154       expansion error (rf_get_munge_headers)
 155   . a problem in rf_get_transport: no transport when one is needed;
 156       failed to expand dynamic transport; failed to find dynamic transport
 157   . bad lookup type
 158   . problem looking up host (rf_lookup_hostlist)
 159   . self = DEFER or FREEZE
 160   . failure to set up uid/gid for running the command
 161   . failure of transport_set_up_command: too many arguments, expansion fail
 162   . failure to create child process
 163   . child process crashed or timed out or didn't return data
 164   . :defer: in data
 165   . DEFER or FREEZE returned
 166   . problem in redirection data
 167   . unknown transport name or trouble expanding router transport
 168
 169 FAIL
 170   . :fail: in data
 171   . FAIL returned
 172   . self = FAIL
 173
 174 OK
 175   . address added to addr_local or addr_remote for delivery
 176   . new addresses added to addr_new
 177 */
 178
 179 int
 180 queryprogram_router_entry(
 181   router_instance *rblock,        /* data for this instantiation */
 182   address_item *addr,             /* address we are working on */
 183   struct passwd *pw,              /* passwd entry after check_local_user */
 184   BOOL verify,                    /* TRUE when verifying */
 185   address_item **addr_local,      /* add it to this if it's local */
 186   address_item **addr_remote,     /* add it to this if it's remote */
 187   address_item **addr_new,        /* put new addresses on here */
 188   address_item **addr_succeed)    /* put old address here on success */
 189 {
 190 int fd_in, fd_out, len, rc;
 191 pid_t pid;
 192 struct passwd *upw = NULL;
 193 uschar buffer[1024];
 194 uschar **argvptr;
 195 uschar *rword, *rdata, *s;
 196 address_item_propagated addr_prop;
 197 queryprogram_router_options_block *ob =
 198   (queryprogram_router_options_block *)(rblock->options_block);
 199 uschar *current_directory = ob->current_directory;
 200 ugid_block ugid;
 201 uid_t uid = ob->cmd_uid;
 202 gid_t gid = ob->cmd_gid;
 203
 204 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
 205   rblock->name, addr->address, addr->domain);
 206
 207 ugid.uid_set = ugid.gid_set = FALSE;
 208
 209 /* Set up the propagated data block with the current address_data and the
 210 errors address and extra header stuff. */
 211
 212 addr_prop.address_data = deliver_address_data;
 213
 214 rc = rf_get_errors_address(addr, rblock, verify, &(addr_prop.errors_address));
 215 if (rc != OK) return rc;
 216
 217 rc = rf_get_munge_headers(addr, rblock, &(addr_prop.extra_headers),
 218   &(addr_prop.remove_headers));
 219 if (rc != OK) return rc;
 220
 221 /* Get the fixed or expanded uid under which the command is to run
 222 (initialization ensures that one or the other is set). */
 223
 224 if (!ob->cmd_uid_set)
 225   {
 226   if (!route_find_expanded_user(ob->expand_cmd_uid, rblock->name, US"router",
 227       &upw, &uid, &(addr->message)))
 228     return DEFER;
 229   }
 230
 231 /* Get the fixed or expanded gid, or take the gid from the passwd entry. */
 232
 233 if (!ob->cmd_gid_set)
 234   {
 235   if (ob->expand_cmd_gid != NULL)
 236     {
 237     if (route_find_expanded_group(ob->expand_cmd_gid, rblock->name,
 238         US"router", &gid, &(addr->message)))
 239       return DEFER;
 240     }
 241   else if (upw != NULL)
 242     {
 243     gid = upw->pw_gid;
 244     }
 245   else
 246     {
 247     addr->message = string_sprintf("command_user set without command_group "
 248       "for %s router", rblock->name);
 249     return DEFER;
 250     }
 251   }
 252
 253 DEBUG(D_route) debug_printf("uid=%ld gid=%ld current_directory=%s\n",
 254   (long int)uid, (long int)gid, current_directory);
 255
 256 if (!transport_set_up_command(&argvptr, /* anchor for arg list */
 257     ob->command,                        /* raw command */
 258     TRUE,                               /* expand the arguments */
 259     0,                                  /* not relevant when... */
 260     NULL,                               /* no transporting address */
 261     US"queryprogram router",            /* for error messages */
 262     &(addr->message)))                  /* where to put error message */
 263   {
 264   return DEFER;
 265   }
 266
 267 /* Create the child process, making it a group leader. */
 268
 269 pid = child_open_uid(argvptr, NULL, 0077, &uid, &gid, &fd_in, &fd_out,
 270   current_directory, TRUE);
 271
 272 if (pid < 0)
 273   {
 274   addr->message = string_sprintf("%s router couldn't create child process: %s",
 275     rblock->name, strerror(errno));
 276   return DEFER;
 277   }
 278
 279 /* Nothing is written to the standard input. */
 280
 281 close(fd_in);
 282
 283 /* Wait for the process to finish, applying the timeout, and inspect its return
 284 code. */
 285
 286 if ((rc = child_close(pid, ob->timeout)) != 0)
 287   {
 288   if (rc > 0)
 289     addr->message = string_sprintf("%s router: command returned non-zero "
 290       "code %d", rblock->name, rc);
 291
 292   else if (rc == -256)
 293     {
 294     addr->message = string_sprintf("%s router: command timed out",
 295       rblock->name);
 296     killpg(pid, SIGKILL);       /* Kill the whole process group */
 297     }
 298
 299   else if (rc == -257)
 300     addr->message = string_sprintf("%s router: wait() failed: %s",
 301       rblock->name, strerror(errno));
 302
 303   else
 304     addr->message = string_sprintf("%s router: command killed by signal %d",
 305       rblock->name, -rc);
 306
 307   return DEFER;
 308   }
 309
 310 /* Read the pipe to get the command's output, and then close it. */
 311
 312 len = read(fd_out, buffer, sizeof(buffer) - 1);
 313 close(fd_out);
 314
 315 /* Failure to return any data is an error. */
 316
 317 if (len <= 0)
 318   {
 319   addr->message = string_sprintf("%s router: command failed to return data",
 320     rblock->name);
 321   return DEFER;
 322   }
 323
 324 /* Get rid of leading and trailing white space, and pick off the first word of
 325 the result. */
 326
 327 while (len > 0 && isspace(buffer[len-1])) len--;
 328 buffer[len] = 0;
 329
 330 DEBUG(D_route) debug_printf("command wrote: %s\n", buffer);
 331
 332 rword = buffer;
 333 while (isspace(*rword)) rword++;
 334 rdata = rword;
 335 while (*rdata != 0 && !isspace(*rdata)) rdata++;
 336 if (*rdata != 0) *rdata++ = 0;
 337
 338 /* The word must be a known yield name. If it is "REDIRECT", the rest of the
 339 line is redirection data, as for a .forward file. It may not contain filter
 340 data, and it may not contain anything other than addresses (no files, no pipes,
 341 no specials). */
 342
 343 if (strcmpic(rword, US"REDIRECT") == 0)
 344   {
 345   int filtertype;
 346   redirect_block redirect;
 347   address_item *generated = NULL;
 348
 349   redirect.string = rdata;
 350   redirect.isfile = FALSE;
 351
 352   rc = rda_interpret(&redirect,  /* redirection data */
 353     RDO_BLACKHOLE |              /* forbid :blackhole: */
 354       RDO_FAIL    |              /* forbid :fail: */
 355       RDO_INCLUDE |              /* forbid :include: */
 356       RDO_REWRITE,               /* rewrite generated addresses */
 357     NULL,                        /* :include: directory not relevant */
 358     NULL,                        /* sieve vacation directory not relevant */
 359     NULL,                        /* sieve useraddress not relevant */
 360     NULL,                        /* sieve subaddress not relevant */
 361     &ugid,                       /* uid/gid (but not set) */
 362     &generated,                  /* where to hang the results */
 363     &(addr->message),            /* where to put messages */
 364     NULL,                        /* don't skip syntax errors */
 365     &filtertype,                 /* not used; will always be FILTER_FORWARD */
 366     string_sprintf("%s router", rblock->name));
 367
 368   switch (rc)
 369     {
 370     /* FF_DEFER and FF_FAIL can arise only as a result of explicit commands.
 371     If a configured message was supplied, allow it to be  included in an SMTP
 372     response after verifying. */
 373
 374     case FF_DEFER:
 375     if (addr->message == NULL) addr->message = US"forced defer";
 376       else addr->user_message = addr->message;
 377     return DEFER;
 378
 379     case FF_FAIL:
 380     add_generated(rblock, addr_new, addr, generated, &addr_prop);
 381     if (addr->message == NULL) addr->message = US"forced rejection";
 382       else addr->user_message = addr->message;
 383     return FAIL;
 384
 385     case FF_DELIVERED:
 386     break;
 387
 388     case FF_NOTDELIVERED:    /* an empty redirection list is bad */
 389     addr->message = US"no addresses supplied";
 390     /* Fall through */
 391
 392     case FF_ERROR:
 393     default:
 394     addr->basic_errno = ERRNO_BADREDIRECT;
 395     addr->message = string_sprintf("error in redirect data: %s", addr->message);
 396     return DEFER;
 397     }
 398
 399   /* Handle the generated addresses, if any. */
 400
 401   add_generated(rblock, addr_new, addr, generated, &addr_prop);
 402
 403   /* Put the original address onto the succeed queue so that any retry items
 404   that get attached to it get processed. */
 405
 406   addr->next = *addr_succeed;
 407   *addr_succeed = addr;
 408
 409   return OK;
 410   }
 411
 412 /* Handle other returns that are not ACCEPT */
 413
 414 if (strcmpic(rword, US"accept") != 0)
 415   {
 416   if (strcmpic(rword, US"decline") == 0) return DECLINE;
 417   if (strcmpic(rword, US"pass") == 0) return PASS;
 418   addr->message = string_copy(rdata);                /* data is a message */
 419   if (strcmpic(rword, US"fail") == 0) return FAIL;
 420   if (strcmpic(rword, US"freeze") == 0) addr->special_action = SPECIAL_FREEZE;
 421   else if (strcmpic(rword, US"defer") != 0)
 422     {
 423     addr->message = string_sprintf("bad command yield: %s %s", rword, rdata);
 424     log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 425     }
 426   return DEFER;
 427   }
 428
 429 /* The command yielded "ACCEPT". The rest of the string is a number of keyed
 430 fields from which we can fish out values using the "extract" expansion
 431 function. To use this feature, we must put the string into the $value variable,
 432 i.e. set lookup_value. */
 433
 434 lookup_value = rdata;
 435 s = expand_string(US"${extract{data}{$value}}");
 436 if (*s != 0) addr_prop.address_data = string_copy(s);
 437
 438 s = expand_string(US"${extract{transport}{$value}}");
 439 lookup_value = NULL;
 440
 441 /* If we found a transport name, find the actual transport */
 442
 443 if (*s != 0)
 444   {
 445   transport_instance *transport;
 446   for (transport = transports; transport != NULL; transport = transport->next)
 447     if (Ustrcmp(transport->name, s) == 0) break;
 448   if (transport == NULL)
 449     {
 450     addr->message = string_sprintf("unknown transport name %s yielded by "
 451       "command", s);
 452     log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 453     return DEFER;
 454     }
 455   addr->transport = transport;
 456   }
 457
 458 /* No transport given; get the transport from the router configuration. It may
 459 be fixed or expanded, but there will be an error if it is unset, requested by
 460 the last argument not being NULL. */
 461
 462 else
 463   {
 464   if (!rf_get_transport(rblock->transport_name, &(rblock->transport), addr,
 465        rblock->name, US"transport"))
 466     return DEFER;
 467   addr->transport = rblock->transport;
 468   }
 469
 470 /* See if a host list is given, and if so, look up the addresses. */
 471
 472 lookup_value = rdata;
 473 s = expand_string(US"${extract{hosts}{$value}}");
 474
 475 if (*s != 0)
 476   {
 477   int lookup_type = lk_default;
 478   uschar *ss = expand_string(US"${extract{lookup}{$value}}");
 479   lookup_value = NULL;
 480
 481   if (*ss != 0)
 482     {
 483     if (Ustrcmp(ss, "byname") == 0) lookup_type = lk_byname;
 484     else if (Ustrcmp(ss, "bydns") == 0) lookup_type = lk_bydns;
 485     else
 486       {
 487       addr->message = string_sprintf("bad lookup type \"%s\" yielded by "
 488         "command", ss);
 489       log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 490       return DEFER;
 491       }
 492     }
 493
 494   host_build_hostlist(&(addr->host_list), s, FALSE);  /* pro tem no randomize */
 495
 496   rc = rf_lookup_hostlist(rblock, addr, rblock->ignore_target_hosts,
 497     lookup_type, hff_defer, addr_new);
 498   if (rc != OK) return rc;
 499   }
 500 lookup_value = NULL;
 501
 502 /* Put the errors address, extra headers, and address_data into this address */
 503
 504 addr->p = addr_prop;
 505
 506 /* Queue the address for local or remote delivery. */
 507
 508 return rf_queue_add(addr, addr_local, addr_remote, rblock, pw)?
 509   OK : DEFER;
 510 }
 511
 512 /* End of routers/queryprogram.c */