src/src/routers/manualroute.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* Copyright (c) The Exim Maintainers 2020 */
   7 /* See the file NOTICE for conditions of use and distribution. */
   8
   9
  10 #include "../exim.h"
  11 #include "rf_functions.h"
  12 #include "manualroute.h"
  13
  14
  15 /* Options specific to the manualroute router. */
  16
  17 optionlist manualroute_router_options[] = {
  18   { "host_all_ignored", opt_stringptr,
  19       OPT_OFF(manualroute_router_options_block, host_all_ignored) },
  20   { "host_find_failed", opt_stringptr,
  21       OPT_OFF(manualroute_router_options_block, host_find_failed) },
  22   { "hosts_randomize",  opt_bool,
  23       OPT_OFF(manualroute_router_options_block, hosts_randomize) },
  24   { "route_data",       opt_stringptr,
  25       OPT_OFF(manualroute_router_options_block, route_data) },
  26   { "route_list",       opt_stringptr,
  27       OPT_OFF(manualroute_router_options_block, route_list) },
  28   { "same_domain_copy_routing", opt_bool|opt_public,
  29       OPT_OFF(router_instance, same_domain_copy_routing) }
  30 };
  31
  32 /* Size of the options list. An extern variable has to be used so that its
  33 address can appear in the tables drtables.c. */
  34
  35 int manualroute_router_options_count =
  36   sizeof(manualroute_router_options)/sizeof(optionlist);
  37
  38
  39 #ifdef MACRO_PREDEF
  40
  41 /* Dummy entries */
  42 manualroute_router_options_block manualroute_router_option_defaults = {0};
  43 void manualroute_router_init(router_instance *rblock) {}
  44 int manualroute_router_entry(router_instance *rblock, address_item *addr,
  45   struct passwd *pw, int verify, address_item **addr_local,
  46   address_item **addr_remote, address_item **addr_new,
  47   address_item **addr_succeed) {return 0;}
  48
  49 #else   /*!MACRO_PREDEF*/
  50
  51
  52
  53 /* Default private options block for the manualroute router. */
  54
  55 manualroute_router_options_block manualroute_router_option_defaults = {
  56   -1,           /* host_all_ignored code (unset) */
  57   -1,           /* host_find_failed code (unset) */
  58   FALSE,        /* hosts_randomize */
  59   US"defer",    /* host_all_ignored */
  60   US"freeze",   /* host_find_failed */
  61   NULL,         /* route_data */
  62   NULL          /* route_list */
  63 };
  64
  65
  66 /* Names and values for host_find_failed and host_all_ignored.  */
  67
  68 static uschar *hff_names[] = {
  69   US"ignore",  /* MUST be first - not valid for host_all_ignored */
  70   US"decline",
  71   US"defer",
  72   US"fail",
  73   US"freeze",
  74   US"pass" };
  75
  76 static int hff_codes[] = { hff_ignore, hff_decline, hff_defer, hff_fail,
  77   hff_freeze, hff_pass };
  78
  79 static int hff_count= sizeof(hff_codes)/sizeof(int);
  80
  81
  82
  83 /*************************************************
  84 *          Initialization entry point            *
  85 *************************************************/
  86
  87 /* Called for each instance, after its options have been read, to enable
  88 consistency checks to be done, or anything else that needs to be set up. */
  89
  90 void
  91 manualroute_router_init(router_instance *rblock)
  92 {
  93 manualroute_router_options_block *ob =
  94   (manualroute_router_options_block *)(rblock->options_block);
  95
  96 /* Host_find_failed must be a recognized word */
  97
  98 for (int i = 0; i < hff_count; i++)
  99   if (Ustrcmp(ob->host_find_failed, hff_names[i]) == 0)
 100     {
 101     ob->hff_code = hff_codes[i];
 102     break;
 103     }
 104 if (ob->hff_code < 0)
 105   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
 106     "unrecognized setting for host_find_failed option", rblock->name);
 107
 108 for (int i = 1; i < hff_count; i++)   /* NB starts at 1 to skip "ignore" */
 109   if (Ustrcmp(ob->host_all_ignored, hff_names[i]) == 0)
 110     {
 111     ob->hai_code = hff_codes[i];
 112     break;
 113     }
 114 if (ob->hai_code < 0)
 115   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
 116     "unrecognized setting for host_all_ignored option", rblock->name);
 117
 118 /* One of route_list or route_data must be specified */
 119
 120 if ((ob->route_list == NULL && ob->route_data == NULL) ||
 121     (ob->route_list != NULL && ob->route_data != NULL))
 122   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
 123     "route_list or route_data (but not both) must be specified",
 124     rblock->name);
 125 }
 126
 127
 128
 129
 130 /*************************************************
 131 *               Parse a route item               *
 132 *************************************************/
 133
 134 /* The format of a route list item is:
 135
 136   <domain> [<host[list]> [<options>]]
 137
 138 if obtained from route_list. The domain is absent if the string came from
 139 route_data, in which case domain==NULL. The domain and the host list may be
 140 enclosed in quotes.
 141
 142 Arguments:
 143   s         pointer to route list item
 144   domain    if not NULL, where to put the domain pointer
 145   hostlist  where to put the host[list] pointer
 146   options   where to put the options pointer
 147
 148 Returns:    FALSE if domain expected and string is empty;
 149             TRUE otherwise
 150 */
 151
 152 static BOOL
 153 parse_route_item(const uschar *s, const uschar **domain, const uschar **hostlist,
 154   const uschar **options)
 155 {
 156 while (*s != 0 && isspace(*s)) s++;
 157
 158 if (domain)
 159   {
 160   if (!*s) return FALSE;            /* missing data */
 161   *domain = string_dequote(&s);
 162   while (*s && isspace(*s)) s++;
 163   }
 164
 165 *hostlist = string_dequote(&s);
 166 while (*s && isspace(*s)) s++;
 167 *options = s;
 168 return TRUE;
 169 }
 170
 171
 172
 173 /*************************************************
 174 *              Main entry point                  *
 175 *************************************************/
 176
 177 /* The manualroute router provides a manual routing facility (surprise,
 178 surprise). The data that defines the routing can either be set in route_data
 179 (which means it can be found by, for example, looking up the domain in a file),
 180 or a list of domain patterns and their corresponding data can be provided in
 181 route_list. */
 182
 183 /* See local README for interface details. This router returns:
 184
 185 DECLINE
 186   . no pattern in route_list matched (route_data not set)
 187   . route_data was an empty string (route_list not set)
 188   . forced expansion failure in route_data (rf_expand_data)
 189   . forced expansion of host list
 190   . host_find_failed = decline
 191
 192 DEFER
 193   . transport not defined when needed
 194   . lookup defer in route_list when matching domain pattern
 195   . non-forced expansion failure in route_data
 196   . non-forced expansion failure in host list
 197   . unknown routing option
 198   . host list missing for remote transport (not verifying)
 199   . timeout etc on host lookup (pass_on_timeout not set)
 200   . verifying the errors address caused a deferment or a big disaster such
 201       as an expansion failure (rf_get_errors_address)
 202   . expanding a headers_{add,remove} string caused a deferment or another
 203       expansion error (rf_get_munge_headers)
 204   . a problem in rf_get_transport: no transport when one is needed;
 205       failed to expand dynamic transport; failed to find dynamic transport
 206   . failure to expand or find a uid/gid (rf_get_ugid via rf_queue_add)
 207   . host_find_failed = freeze or defer
 208   . self = freeze or defer
 209
 210 PASS
 211   . timeout etc on host lookup (pass_on_timeout set)
 212   . host_find_failed = pass
 213   . self = pass
 214
 215 REROUTED
 216   . self = reroute
 217
 218 FAIL
 219   . host_find_failed = fail
 220   . self = fail
 221
 222 OK
 223   . added address to addr_local or addr_remote, as appropriate for the
 224     type of transport; this includes the self="send" case.
 225 */
 226
 227 int
 228 manualroute_router_entry(
 229   router_instance *rblock,        /* data for this instantiation */
 230   address_item *addr,             /* address we are working on */
 231   struct passwd *pw,              /* passwd entry after check_local_user */
 232   int verify,                     /* v_none/v_recipient/v_sender/v_expn */
 233   address_item **addr_local,      /* add it to this if it's local */
 234   address_item **addr_remote,     /* add it to this if it's remote */
 235   address_item **addr_new,        /* put new addresses on here */
 236   address_item **addr_succeed)    /* put old address here on success */
 237 {
 238 int rc, lookup_type;
 239 uschar *route_item = NULL;
 240 const uschar *options = NULL;
 241 const uschar *hostlist = NULL;
 242 const uschar *domain;
 243 uschar *newhostlist;
 244 const uschar *listptr;
 245 manualroute_router_options_block *ob =
 246   (manualroute_router_options_block *)(rblock->options_block);
 247 transport_instance *transport = NULL;
 248 BOOL individual_transport_set = FALSE;
 249 BOOL randomize = ob->hosts_randomize;
 250
 251 addr_new = addr_new;           /* Keep picky compilers happy */
 252 addr_succeed = addr_succeed;
 253
 254 DEBUG(D_route) debug_printf("%s router called for %s\n  domain = %s\n",
 255   rblock->name, addr->address, addr->domain);
 256
 257 /* The initialization check ensures that either route_list or route_data is
 258 set. */
 259
 260 if (ob->route_list)
 261   {
 262   int sep = -(';');             /* Default is semicolon */
 263   listptr = ob->route_list;
 264
 265   while ((route_item = string_nextinlist(&listptr, &sep, NULL, 0)) != NULL)
 266     {
 267     int rc;
 268
 269     DEBUG(D_route) debug_printf("route_item = %s\n", route_item);
 270     if (!parse_route_item(route_item, &domain, &hostlist, &options))
 271       continue;     /* Ignore blank items */
 272
 273     /* Check the current domain; if it matches, break the loop */
 274
 275     if ((rc = match_isinlist(addr->domain, &domain, UCHAR_MAX+1,
 276            &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, CUSS &lookup_value)) == OK)
 277       break;
 278
 279     /* If there was a problem doing the check, defer */
 280
 281     if (rc == DEFER)
 282       {
 283       addr->message = US"lookup defer in route_list";
 284       return DEFER;
 285       }
 286     }
 287
 288   if (!route_item) return DECLINE;  /* No pattern in the list matched */
 289   }
 290
 291 /* Handle a single routing item in route_data. If it expands to an empty
 292 string, decline. */
 293
 294 else
 295   {
 296   if (!(route_item = rf_expand_data(addr, ob->route_data, &rc)))
 297     return rc;
 298   (void) parse_route_item(route_item, NULL, &hostlist, &options);
 299   if (!hostlist[0]) return DECLINE;
 300   }
 301
 302 /* Expand the hostlist item. It may then pointing to an empty string, or to a
 303 single host or a list of hosts; options is pointing to the rest of the
 304 routelist item, which is either empty or contains various option words. */
 305
 306 DEBUG(D_route) debug_printf("original list of hosts = '%s' options = '%s'\n",
 307   hostlist, options);
 308
 309 newhostlist = expand_string_copy(hostlist);
 310 lookup_value = NULL;                        /* Finished with */
 311 expand_nmax = -1;
 312
 313 /* If the expansion was forced to fail, just decline. Otherwise there is a
 314 configuration problem. */
 315
 316 if (!newhostlist)
 317   {
 318   if (f.expand_string_forcedfail) return DECLINE;
 319   addr->message = string_sprintf("%s router: failed to expand \"%s\": %s",
 320     rblock->name, hostlist, expand_string_message);
 321   return DEFER;
 322   }
 323 else hostlist = newhostlist;
 324
 325 DEBUG(D_route) debug_printf("expanded list of hosts = '%s' options = '%s'\n",
 326   hostlist, options);
 327
 328 /* Set default lookup type and scan the options */
 329
 330 lookup_type = LK_DEFAULT;
 331
 332 while (*options)
 333   {
 334   unsigned n;
 335   const uschar *s = options;
 336   while (*options != 0 && !isspace(*options)) options++;
 337   n = options-s;
 338
 339   if (Ustrncmp(s, "randomize", n) == 0) randomize = TRUE;
 340   else if (Ustrncmp(s, "no_randomize", n) == 0) randomize = FALSE;
 341   else if (Ustrncmp(s, "byname", n) == 0)
 342     lookup_type = lookup_type & ~(LK_DEFAULT | LK_BYDNS) | LK_BYNAME;
 343   else if (Ustrncmp(s, "bydns", n) == 0)
 344     lookup_type = lookup_type & ~(LK_DEFAULT | LK_BYNAME) & LK_BYDNS;
 345   else if (Ustrncmp(s, "ipv4_prefer", n) == 0) lookup_type |= LK_IPV4_PREFER;
 346   else if (Ustrncmp(s, "ipv4_only",   n) == 0) lookup_type |= LK_IPV4_ONLY;
 347   else
 348     {
 349     transport_instance *t;
 350     for (t = transports; t; t = t->next)
 351       if (Ustrncmp(t->name, s, n) == 0)
 352         {
 353         transport = t;
 354         individual_transport_set = TRUE;
 355         break;
 356         }
 357
 358     if (!t)
 359       {
 360       s = string_sprintf("unknown routing option or transport name \"%s\"", s);
 361       log_write(0, LOG_MAIN, "Error in %s router: %s", rblock->name, s);
 362       addr->message = string_sprintf("error in router: %s", s);
 363       return DEFER;
 364       }
 365     }
 366
 367   if (*options)
 368     {
 369     options++;
 370     while (*options != 0 && isspace(*options)) options++;
 371     }
 372   }
 373
 374 /* Set up the errors address, if any. */
 375
 376 rc = rf_get_errors_address(addr, rblock, verify, &addr->prop.errors_address);
 377 if (rc != OK) return rc;
 378
 379 /* Set up the additional and removable headers for this address. */
 380
 381 rc = rf_get_munge_headers(addr, rblock, &addr->prop.extra_headers,
 382   &addr->prop.remove_headers);
 383 if (rc != OK) return rc;
 384
 385 /* If an individual transport is not set, get the transport for this router, if
 386 any. It might be expanded, or it might be unset if this router has verify_only
 387 set. */
 388
 389 if (!individual_transport_set)
 390   {
 391   if (!rf_get_transport(rblock->transport_name, &(rblock->transport), addr,
 392       rblock->name, NULL))
 393     return DEFER;
 394   transport = rblock->transport;
 395   }
 396
 397 /* Deal with the case of a local transport. The host list is passed over as a
 398 single text string that ends up in $host. */
 399
 400 if (transport && transport->info->local)
 401   {
 402   if (hostlist[0])
 403     {
 404     host_item *h;
 405     addr->host_list = h = store_get(sizeof(host_item), FALSE);
 406     h->name = string_copy(hostlist);
 407     h->address = NULL;
 408     h->port = PORT_NONE;
 409     h->mx = MX_NONE;
 410     h->status = hstatus_unknown;
 411     h->why = hwhy_unknown;
 412     h->last_try = 0;
 413     h->next = NULL;
 414     }
 415
 416   /* There is nothing more to do other than to queue the address for the
 417   local transport, filling in any uid/gid. This can be done by the common
 418   rf_queue_add() function. */
 419
 420   addr->transport = transport;
 421   return rf_queue_add(addr, addr_local, addr_remote, rblock, pw)?
 422     OK : DEFER;
 423   }
 424
 425 /* There is either no transport (verify_only) or a remote transport. A host
 426 list is mandatory in either case, except when verifying, in which case the
 427 address is just accepted. */
 428
 429 if (!hostlist[0])
 430   {
 431   if (verify != v_none) goto ROUTED;
 432   addr->message = string_sprintf("error in %s router: no host(s) specified "
 433     "for domain %s", rblock->name, addr->domain);
 434   log_write(0, LOG_MAIN, "%s", addr->message);
 435   return DEFER;
 436   }
 437
 438 /* Otherwise we finish the routing here by building a chain of host items
 439 for the list of configured hosts, and then finding their addresses. */
 440
 441 host_build_hostlist(&addr->host_list, hostlist, randomize);
 442 rc = rf_lookup_hostlist(rblock, addr, rblock->ignore_target_hosts, lookup_type,
 443   ob->hff_code, addr_new);
 444 if (rc != OK) return rc;
 445
 446 /* If host_find_failed is set to "ignore", it is possible for all the hosts to
 447 be ignored, in which case we will end up with an empty host list. What happens
 448 is controlled by host_all_ignored. */
 449
 450 if (!addr->host_list)
 451   {
 452   int i;
 453   DEBUG(D_route) debug_printf("host_find_failed ignored every host\n");
 454   if (ob->hai_code == hff_decline) return DECLINE;
 455   if (ob->hai_code == hff_pass) return PASS;
 456
 457   for (i = 0; i < hff_count; i++)
 458     if (ob->hai_code == hff_codes[i]) break;
 459
 460   addr->message = string_sprintf("lookup failed for all hosts in %s router: "
 461     "host_find_failed=ignore host_all_ignored=%s", rblock->name, hff_names[i]);
 462
 463   if (ob->hai_code == hff_defer) return DEFER;
 464   if (ob->hai_code == hff_fail) return FAIL;
 465
 466   addr->special_action = SPECIAL_FREEZE;
 467   return DEFER;
 468   }
 469
 470 /* Finally, since we have done all the routing here, there must be a transport
 471 defined for these hosts. It will be a remote one, as a local transport is
 472 dealt with above. However, we don't need one if verifying only. */
 473
 474 if (transport == NULL && verify == v_none)
 475     {
 476     log_write(0, LOG_MAIN, "Error in %s router: no transport defined",
 477       rblock->name);
 478     addr->message = US"error in router: transport missing";
 479     return DEFER;
 480     }
 481
 482 /* Fill in the transport, queue for remote delivery. The yield of
 483 rf_queue_add() is always TRUE for a remote transport. */
 484
 485 ROUTED:
 486
 487 addr->transport = transport;
 488 (void)rf_queue_add(addr, addr_local, addr_remote, rblock, NULL);
 489 return OK;
 490 }
 491
 492 #endif   /*!MACRO_PREDEF*/
 493 /* End of routers/manualroute.c */