src/routers/queryprogram.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2009 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #include "../exim.h"
   9 #include "rf_functions.h"
  10 #include "queryprogram.h"
  11
  12
  13
  14 /* Options specific to the queryprogram router. */
  15
  16 optionlist queryprogram_router_options[] = {
  17   { "*expand_command_group", opt_bool | opt_hidden,
  18       (void *)(offsetof(queryprogram_router_options_block, expand_cmd_gid)) },
  19   { "*expand_command_user", opt_bool | opt_hidden,
  20       (void *)(offsetof(queryprogram_router_options_block, expand_cmd_uid)) },
  21   { "*set_command_group",   opt_bool | opt_hidden,
  22       (void *)(offsetof(queryprogram_router_options_block, cmd_gid_set)) },
  23   { "*set_command_user",    opt_bool | opt_hidden,
  24       (void *)(offsetof(queryprogram_router_options_block, cmd_uid_set)) },
  25   { "command",      opt_stringptr,
  26       (void *)(offsetof(queryprogram_router_options_block, command)) },
  27   { "command_group",opt_expand_gid,
  28       (void *)(offsetof(queryprogram_router_options_block, cmd_gid)) },
  29   { "command_user", opt_expand_uid,
  30       (void *)(offsetof(queryprogram_router_options_block, cmd_uid)) },
  31   { "current_directory", opt_stringptr,
  32       (void *)(offsetof(queryprogram_router_options_block, current_directory)) },
  33   { "timeout",      opt_time,
  34       (void *)(offsetof(queryprogram_router_options_block, timeout)) }
  35 };
  36
  37 /* Size of the options list. An extern variable has to be used so that its
  38 address can appear in the tables drtables.c. */
  39
  40 int queryprogram_router_options_count =
  41   sizeof(queryprogram_router_options)/sizeof(optionlist);
  42
  43 /* Default private options block for the queryprogram router. */
  44
  45 queryprogram_router_options_block queryprogram_router_option_defaults = {
  46   NULL,         /* command */
  47   60*60,        /* timeout */
  48   (uid_t)(-1),  /* cmd_uid */
  49   (gid_t)(-1),  /* cmd_gid */
  50   FALSE,        /* cmd_uid_set */
  51   FALSE,        /* cmd_gid_set */
  52   US"/",        /* current_directory */
  53   NULL,         /* expand_cmd_gid */
  54   NULL          /* expand_cmd_uid */
  55 };
  56
  57
  58
  59 /*************************************************
  60 *          Initialization entry point            *
  61 *************************************************/
  62
  63 /* Called for each instance, after its options have been read, to enable
  64 consistency checks to be done, or anything else that needs to be set up. */
  65
  66 void
  67 queryprogram_router_init(router_instance *rblock)
  68 {
  69 queryprogram_router_options_block *ob =
  70   (queryprogram_router_options_block *)(rblock->options_block);
  71
  72 /* A command must be given */
  73
  74 if (ob->command == NULL)
  75   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  76     "a command specification is required", rblock->name);
  77
  78 /* A uid/gid must be supplied */
  79
  80 if (!ob->cmd_uid_set && ob->expand_cmd_uid == NULL)
  81   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  82     "command_user must be specified", rblock->name);
  83 }
  84
  85
  86
  87 /*************************************************
  88 *    Process a set of generated new addresses    *
  89 *************************************************/
  90
  91 /* This function sets up a set of newly generated child addresses and puts them
  92 on the new address chain.
  93
  94 Arguments:
  95   rblock                  router block
  96   addr_new                new address chain
  97   addr                    original address
  98   generated               list of generated addresses
  99   addr_prop               the propagated data block, containing errors_to,
 100                             header change stuff, and address_data
 101
 102 Returns:         nothing
 103 */
 104
 105 static void
 106 add_generated(router_instance *rblock, address_item **addr_new,
 107   address_item *addr, address_item *generated,
 108   address_item_propagated *addr_prop)
 109 {
 110 while (generated != NULL)
 111   {
 112   address_item *next = generated;
 113   generated = next->next;
 114
 115   next->parent = addr;
 116   orflag(next, addr, af_propagate);
 117   next->p = *addr_prop;
 118   next->start_router = rblock->redirect_router;
 119
 120   next->next = *addr_new;
 121   *addr_new = next;
 122
 123   if (addr->child_count == SHRT_MAX)
 124     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
 125       "child addresses for <%s>", rblock->name, SHRT_MAX, addr->address);
 126   addr->child_count++;
 127
 128   DEBUG(D_route)
 129     debug_printf("%s router generated %s\n", rblock->name, next->address);
 130   }
 131 }
 132
 133
 134
 135
 136 /*************************************************
 137 *              Main entry point                  *
 138 *************************************************/
 139
 140 /* See local README for interface details. This router returns:
 141
 142 DECLINE
 143   . DECLINE returned
 144   . self = DECLINE
 145
 146 PASS
 147   . PASS returned
 148   . timeout of host lookup and pass_on_timeout set
 149   . self = PASS
 150
 151 DEFER
 152   . verifying the errors address caused a deferment or a big disaster such
 153       as an expansion failure (rf_get_errors_address)
 154   . expanding a headers_{add,remove} string caused a deferment or another
 155       expansion error (rf_get_munge_headers)
 156   . a problem in rf_get_transport: no transport when one is needed;
 157       failed to expand dynamic transport; failed to find dynamic transport
 158   . bad lookup type
 159   . problem looking up host (rf_lookup_hostlist)
 160   . self = DEFER or FREEZE
 161   . failure to set up uid/gid for running the command
 162   . failure of transport_set_up_command: too many arguments, expansion fail
 163   . failure to create child process
 164   . child process crashed or timed out or didn't return data
 165   . :defer: in data
 166   . DEFER or FREEZE returned
 167   . problem in redirection data
 168   . unknown transport name or trouble expanding router transport
 169
 170 FAIL
 171   . :fail: in data
 172   . FAIL returned
 173   . self = FAIL
 174
 175 OK
 176   . address added to addr_local or addr_remote for delivery
 177   . new addresses added to addr_new
 178 */
 179
 180 int
 181 queryprogram_router_entry(
 182   router_instance *rblock,        /* data for this instantiation */
 183   address_item *addr,             /* address we are working on */
 184   struct passwd *pw,              /* passwd entry after check_local_user */
 185   int verify,                     /* v_none/v_recipient/v_sender/v_expn */
 186   address_item **addr_local,      /* add it to this if it's local */
 187   address_item **addr_remote,     /* add it to this if it's remote */
 188   address_item **addr_new,        /* put new addresses on here */
 189   address_item **addr_succeed)    /* put old address here on success */
 190 {
 191 int fd_in, fd_out, len, rc;
 192 pid_t pid;
 193 struct passwd *upw = NULL;
 194 uschar buffer[1024];
 195 uschar **argvptr;
 196 uschar *rword, *rdata, *s;
 197 address_item_propagated addr_prop;
 198 queryprogram_router_options_block *ob =
 199   (queryprogram_router_options_block *)(rblock->options_block);
 200 uschar *current_directory = ob->current_directory;
 201 ugid_block ugid;
 202 uid_t curr_uid = getuid();
 203 gid_t curr_gid = getgid();
 204 uid_t uid = ob->cmd_uid;
 205 gid_t gid = ob->cmd_gid;
 206 uid_t *puid = &uid;
 207 gid_t *pgid = &gid;
 208
 209 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
 210   rblock->name, addr->address, addr->domain);
 211
 212 ugid.uid_set = ugid.gid_set = FALSE;
 213
 214 /* Set up the propagated data block with the current address_data and the
 215 errors address and extra header stuff. */
 216
 217 addr_prop.address_data = deliver_address_data;
 218
 219 rc = rf_get_errors_address(addr, rblock, verify, &(addr_prop.errors_address));
 220 if (rc != OK) return rc;
 221
 222 rc = rf_get_munge_headers(addr, rblock, &(addr_prop.extra_headers),
 223   &(addr_prop.remove_headers));
 224 if (rc != OK) return rc;
 225
 226 /* Get the fixed or expanded uid under which the command is to run
 227 (initialization ensures that one or the other is set). */
 228
 229 if (!ob->cmd_uid_set)
 230   {
 231   if (!route_find_expanded_user(ob->expand_cmd_uid, rblock->name, US"router",
 232       &upw, &uid, &(addr->message)))
 233     return DEFER;
 234   }
 235
 236 /* Get the fixed or expanded gid, or take the gid from the passwd entry. */
 237
 238 if (!ob->cmd_gid_set)
 239   {
 240   if (ob->expand_cmd_gid != NULL)
 241     {
 242     if (route_find_expanded_group(ob->expand_cmd_gid, rblock->name,
 243         US"router", &gid, &(addr->message)))
 244       return DEFER;
 245     }
 246   else if (upw != NULL)
 247     {
 248     gid = upw->pw_gid;
 249     }
 250   else
 251     {
 252     addr->message = string_sprintf("command_user set without command_group "
 253       "for %s router", rblock->name);
 254     return DEFER;
 255     }
 256   }
 257
 258 DEBUG(D_route) debug_printf("requires uid=%ld gid=%ld current_directory=%s\n",
 259   (long int)uid, (long int)gid, current_directory);
 260
 261 /* If we are not running as root, we will not be able to change uid/gid. */
 262
 263 if (curr_uid != root_uid && (uid != curr_uid || gid != curr_gid))
 264   {
 265   DEBUG(D_route)
 266     {
 267     debug_printf("not running as root: cannot change uid/gid\n");
 268     debug_printf("subprocess will run with uid=%ld gid=%ld\n",
 269       (long int)curr_uid, (long int)curr_gid);
 270     }
 271   puid = pgid = NULL;
 272   }
 273
 274 /* Set up the command to run */
 275
 276 if (!transport_set_up_command(&argvptr, /* anchor for arg list */
 277     ob->command,                        /* raw command */
 278     TRUE,                               /* expand the arguments */
 279     0,                                  /* not relevant when... */
 280     NULL,                               /* no transporting address */
 281     US"queryprogram router",            /* for error messages */
 282     &(addr->message)))                  /* where to put error message */
 283   {
 284   return DEFER;
 285   }
 286
 287 /* Create the child process, making it a group leader. */
 288
 289 pid = child_open_uid(argvptr, NULL, 0077, puid, pgid, &fd_in, &fd_out,
 290   current_directory, TRUE);
 291
 292 if (pid < 0)
 293   {
 294   addr->message = string_sprintf("%s router couldn't create child process: %s",
 295     rblock->name, strerror(errno));
 296   return DEFER;
 297   }
 298
 299 /* Nothing is written to the standard input. */
 300
 301 (void)close(fd_in);
 302
 303 /* Wait for the process to finish, applying the timeout, and inspect its return
 304 code. */
 305
 306 if ((rc = child_close(pid, ob->timeout)) != 0)
 307   {
 308   if (rc > 0)
 309     addr->message = string_sprintf("%s router: command returned non-zero "
 310       "code %d", rblock->name, rc);
 311
 312   else if (rc == -256)
 313     {
 314     addr->message = string_sprintf("%s router: command timed out",
 315       rblock->name);
 316     killpg(pid, SIGKILL);       /* Kill the whole process group */
 317     }
 318
 319   else if (rc == -257)
 320     addr->message = string_sprintf("%s router: wait() failed: %s",
 321       rblock->name, strerror(errno));
 322
 323   else
 324     addr->message = string_sprintf("%s router: command killed by signal %d",
 325       rblock->name, -rc);
 326
 327   return DEFER;
 328   }
 329
 330 /* Read the pipe to get the command's output, and then close it. */
 331
 332 len = read(fd_out, buffer, sizeof(buffer) - 1);
 333 (void)close(fd_out);
 334
 335 /* Failure to return any data is an error. */
 336
 337 if (len <= 0)
 338   {
 339   addr->message = string_sprintf("%s router: command failed to return data",
 340     rblock->name);
 341   return DEFER;
 342   }
 343
 344 /* Get rid of leading and trailing white space, and pick off the first word of
 345 the result. */
 346
 347 while (len > 0 && isspace(buffer[len-1])) len--;
 348 buffer[len] = 0;
 349
 350 DEBUG(D_route) debug_printf("command wrote: %s\n", buffer);
 351
 352 rword = buffer;
 353 while (isspace(*rword)) rword++;
 354 rdata = rword;
 355 while (*rdata != 0 && !isspace(*rdata)) rdata++;
 356 if (*rdata != 0) *rdata++ = 0;
 357
 358 /* The word must be a known yield name. If it is "REDIRECT", the rest of the
 359 line is redirection data, as for a .forward file. It may not contain filter
 360 data, and it may not contain anything other than addresses (no files, no pipes,
 361 no specials). */
 362
 363 if (strcmpic(rword, US"REDIRECT") == 0)
 364   {
 365   int filtertype;
 366   redirect_block redirect;
 367   address_item *generated = NULL;
 368
 369   redirect.string = rdata;
 370   redirect.isfile = FALSE;
 371
 372   rc = rda_interpret(&redirect,  /* redirection data */
 373     RDO_BLACKHOLE |              /* forbid :blackhole: */
 374       RDO_FAIL    |              /* forbid :fail: */
 375       RDO_INCLUDE |              /* forbid :include: */
 376       RDO_REWRITE,               /* rewrite generated addresses */
 377     NULL,                        /* :include: directory not relevant */
 378     NULL,                        /* sieve vacation directory not relevant */
 379     NULL,                        /* sieve enotify mailto owner not relevant */
 380     NULL,                        /* sieve useraddress not relevant */
 381     NULL,                        /* sieve subaddress not relevant */
 382     &ugid,                       /* uid/gid (but not set) */
 383     &generated,                  /* where to hang the results */
 384     &(addr->message),            /* where to put messages */
 385     NULL,                        /* don't skip syntax errors */
 386     &filtertype,                 /* not used; will always be FILTER_FORWARD */
 387     string_sprintf("%s router", rblock->name));
 388
 389   switch (rc)
 390     {
 391     /* FF_DEFER and FF_FAIL can arise only as a result of explicit commands.
 392     If a configured message was supplied, allow it to be  included in an SMTP
 393     response after verifying. */
 394
 395     case FF_DEFER:
 396     if (addr->message == NULL) addr->message = US"forced defer";
 397       else addr->user_message = addr->message;
 398     return DEFER;
 399
 400     case FF_FAIL:
 401     add_generated(rblock, addr_new, addr, generated, &addr_prop);
 402     if (addr->message == NULL) addr->message = US"forced rejection";
 403       else addr->user_message = addr->message;
 404     return FAIL;
 405
 406     case FF_DELIVERED:
 407     break;
 408
 409     case FF_NOTDELIVERED:    /* an empty redirection list is bad */
 410     addr->message = US"no addresses supplied";
 411     /* Fall through */
 412
 413     case FF_ERROR:
 414     default:
 415     addr->basic_errno = ERRNO_BADREDIRECT;
 416     addr->message = string_sprintf("error in redirect data: %s", addr->message);
 417     return DEFER;
 418     }
 419
 420   /* Handle the generated addresses, if any. */
 421
 422   add_generated(rblock, addr_new, addr, generated, &addr_prop);
 423
 424   /* Put the original address onto the succeed queue so that any retry items
 425   that get attached to it get processed. */
 426
 427   addr->next = *addr_succeed;
 428   *addr_succeed = addr;
 429
 430   return OK;
 431   }
 432
 433 /* Handle other returns that are not ACCEPT */
 434
 435 if (strcmpic(rword, US"accept") != 0)
 436   {
 437   if (strcmpic(rword, US"decline") == 0) return DECLINE;
 438   if (strcmpic(rword, US"pass") == 0) return PASS;
 439   addr->message = string_copy(rdata);                /* data is a message */
 440   if (strcmpic(rword, US"fail") == 0)
 441     {
 442     setflag(addr, af_pass_message);
 443     return FAIL;
 444     }
 445   if (strcmpic(rword, US"freeze") == 0) addr->special_action = SPECIAL_FREEZE;
 446   else if (strcmpic(rword, US"defer") != 0)
 447     {
 448     addr->message = string_sprintf("bad command yield: %s %s", rword, rdata);
 449     log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 450     }
 451   return DEFER;
 452   }
 453
 454 /* The command yielded "ACCEPT". The rest of the string is a number of keyed
 455 fields from which we can fish out values using the "extract" expansion
 456 function. To use this feature, we must put the string into the $value variable,
 457 i.e. set lookup_value. */
 458
 459 lookup_value = rdata;
 460 s = expand_string(US"${extract{data}{$value}}");
 461 if (*s != 0) addr_prop.address_data = string_copy(s);
 462
 463 s = expand_string(US"${extract{transport}{$value}}");
 464 lookup_value = NULL;
 465
 466 /* If we found a transport name, find the actual transport */
 467
 468 if (*s != 0)
 469   {
 470   transport_instance *transport;
 471   for (transport = transports; transport != NULL; transport = transport->next)
 472     if (Ustrcmp(transport->name, s) == 0) break;
 473   if (transport == NULL)
 474     {
 475     addr->message = string_sprintf("unknown transport name %s yielded by "
 476       "command", s);
 477     log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 478     return DEFER;
 479     }
 480   addr->transport = transport;
 481   }
 482
 483 /* No transport given; get the transport from the router configuration. It may
 484 be fixed or expanded, but there will be an error if it is unset, requested by
 485 the last argument not being NULL. */
 486
 487 else
 488   {
 489   if (!rf_get_transport(rblock->transport_name, &(rblock->transport), addr,
 490        rblock->name, US"transport"))
 491     return DEFER;
 492   addr->transport = rblock->transport;
 493   }
 494
 495 /* See if a host list is given, and if so, look up the addresses. */
 496
 497 lookup_value = rdata;
 498 s = expand_string(US"${extract{hosts}{$value}}");
 499
 500 if (*s != 0)
 501   {
 502   int lookup_type = lk_default;
 503   uschar *ss = expand_string(US"${extract{lookup}{$value}}");
 504   lookup_value = NULL;
 505
 506   if (*ss != 0)
 507     {
 508     if (Ustrcmp(ss, "byname") == 0) lookup_type = lk_byname;
 509     else if (Ustrcmp(ss, "bydns") == 0) lookup_type = lk_bydns;
 510     else
 511       {
 512       addr->message = string_sprintf("bad lookup type \"%s\" yielded by "
 513         "command", ss);
 514       log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
 515       return DEFER;
 516       }
 517     }
 518
 519   host_build_hostlist(&(addr->host_list), s, FALSE);  /* pro tem no randomize */
 520
 521   rc = rf_lookup_hostlist(rblock, addr, rblock->ignore_target_hosts,
 522     lookup_type, hff_defer, addr_new);
 523   if (rc != OK) return rc;
 524   }
 525 lookup_value = NULL;
 526
 527 /* Put the errors address, extra headers, and address_data into this address */
 528
 529 addr->p = addr_prop;
 530
 531 /* Queue the address for local or remote delivery. */
 532
 533 return rf_queue_add(addr, addr_local, addr_remote, rblock, pw)?
 534   OK : DEFER;
 535 }
 536
 537 /* End of routers/queryprogram.c */