src/routers/iplookup.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
   9 #include "../exim.h"
  10 #include "rf_functions.h"
  11 #include "iplookup.h"
  12
  13
  14 /* IP connection types */
  15
  16 #define ip_udp 0
  17 #define ip_tcp 1
  18
  19
  20 /* Options specific to the iplookup router. */
  21
  22 optionlist iplookup_router_options[] = {
  23   { "hosts",    opt_stringptr,
  24       (void *)(offsetof(iplookup_router_options_block, hosts)) },
  25   { "optional", opt_bool,
  26       (void *)(offsetof(iplookup_router_options_block, optional)) },
  27   { "port",     opt_int,
  28       (void *)(offsetof(iplookup_router_options_block, port)) },
  29   { "protocol", opt_stringptr,
  30       (void *)(offsetof(iplookup_router_options_block, protocol_name)) },
  31   { "query",    opt_stringptr,
  32       (void *)(offsetof(iplookup_router_options_block, query)) },
  33   { "reroute",  opt_stringptr,
  34       (void *)(offsetof(iplookup_router_options_block, reroute)) },
  35   { "response_pattern", opt_stringptr,
  36       (void *)(offsetof(iplookup_router_options_block, response_pattern)) },
  37   { "timeout",  opt_time,
  38       (void *)(offsetof(iplookup_router_options_block, timeout)) }
  39 };
  40
  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. */
  43
  44 int iplookup_router_options_count =
  45   sizeof(iplookup_router_options)/sizeof(optionlist);
  46
  47 /* Default private options block for the iplookup router. */
  48
  49 iplookup_router_options_block iplookup_router_option_defaults = {
  50   -1,       /* port */
  51   ip_udp,   /* protocol */
  52   5,        /* timeout */
  53   NULL,     /* protocol_name */
  54   NULL,     /* hosts */
  55   NULL,     /* query; NULL => local_part@domain */
  56   NULL,     /* response_pattern; NULL => don't apply regex */
  57   NULL,     /* reroute; NULL => just used returned data */
  58   NULL,     /* re_response_pattern; compiled pattern */
  59   FALSE     /* optional */
  60 };
  61
  62
  63
  64 /*************************************************
  65 *          Initialization entry point            *
  66 *************************************************/
  67
  68 /* Called for each instance, after its options have been read, to enable
  69 consistency checks to be done, or anything else that needs to be set up. */
  70
  71 void
  72 iplookup_router_init(router_instance *rblock)
  73 {
  74 iplookup_router_options_block *ob =
  75   (iplookup_router_options_block *)(rblock->options_block);
  76
  77 /* A port and a host list must be given */
  78
  79 if (ob->port < 0)
  80   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  81     "a port must be specified", rblock->name);
  82
  83 if (ob->hosts == NULL)
  84   log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  85     "a host list must be specified", rblock->name);
  86
  87 /* Translate protocol name into value */
  88
  89 if (ob->protocol_name != NULL)
  90   {
  91   if (Ustrcmp(ob->protocol_name, "udp") == 0) ob->protocol = ip_udp;
  92   else if (Ustrcmp(ob->protocol_name, "tcp") == 0) ob->protocol = ip_tcp;
  93   else log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
  94     "protocol not specified as udp or tcp", rblock->name);
  95   }
  96
  97 /* If a response pattern is given, compile it now to get the error early. */
  98
  99 if (ob->response_pattern != NULL)
 100   ob->re_response_pattern =
 101     regex_must_compile(ob->response_pattern, FALSE, TRUE);
 102 }
 103
 104
 105
 106 /*************************************************
 107 *              Main entry point                  *
 108 *************************************************/
 109
 110 /* See local README for interface details. This router returns:
 111
 112 DECLINE
 113   . pattern or identification match on returned data failed
 114
 115 DEFER
 116   . failed to expand the query or rerouting string
 117   . failed to create socket ("optional" not set)
 118   . failed to find a host, failed to connect, timed out ("optional" not set)
 119   . rerouting string is not in the form localpart@domain
 120   . verifying the errors address caused a deferment or a big disaster such
 121       as an expansion failure (rf_get_errors_address)
 122   . expanding a headers_{add,remove} string caused a deferment or another
 123       expansion error (rf_get_munge_headers)
 124
 125 PASS
 126   . failed to create socket ("optional" set)
 127   . failed to find a host, failed to connect, timed out ("optional" set)
 128
 129 OK
 130   . new address added to addr_new
 131 */
 132
 133 int
 134 iplookup_router_entry(
 135   router_instance *rblock,        /* data for this instantiation */
 136   address_item *addr,             /* address we are working on */
 137   struct passwd *pw,              /* passwd entry after check_local_user */
 138   int verify,                     /* v_none/v_recipient/v_sender/v_expn */
 139   address_item **addr_local,      /* add it to this if it's local */
 140   address_item **addr_remote,     /* add it to this if it's remote */
 141   address_item **addr_new,        /* put new addresses on here */
 142   address_item **addr_succeed)    /* put old address here on success */
 143 {
 144 uschar *query = NULL;
 145 uschar *reply;
 146 uschar *hostname, *reroute, *domain, *listptr;
 147 uschar host_buffer[256];
 148 host_item *host = store_get(sizeof(host_item));
 149 address_item *new_addr;
 150 iplookup_router_options_block *ob =
 151   (iplookup_router_options_block *)(rblock->options_block);
 152 const pcre *re = ob->re_response_pattern;
 153 int count, query_len, rc;
 154 int sep = 0;
 155
 156 addr_local = addr_local;    /* Keep picky compilers happy */
 157 addr_remote = addr_remote;
 158 addr_succeed = addr_succeed;
 159 pw = pw;
 160
 161 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
 162   rblock->name, addr->address, addr->domain);
 163
 164 reply = store_get(256);
 165
 166 /* Build the query string to send. If not explicitly given, a default of
 167 "user@domain user@domain" is used. */
 168
 169 if (ob->query == NULL)
 170   query = string_sprintf("%s@%s %s@%s", addr->local_part, addr->domain,
 171     addr->local_part, addr->domain);
 172 else
 173   {
 174   query = expand_string(ob->query);
 175   if (query == NULL)
 176     {
 177     addr->message = string_sprintf("%s router: failed to expand %s: %s",
 178       rblock->name, ob->query, expand_string_message);
 179     return DEFER;
 180     }
 181   }
 182
 183 query_len = Ustrlen(query);
 184 DEBUG(D_route) debug_printf("%s router query is \"%s\"\n", rblock->name,
 185   string_printing(query));
 186
 187 /* Now connect to the required port for each of the hosts in turn, until a
 188 response it received. Initialization insists on the port being set and there
 189 being a host list. */
 190
 191 listptr = ob->hosts;
 192 while ((hostname = string_nextinlist(&listptr, &sep, host_buffer,
 193        sizeof(host_buffer))) != NULL)
 194   {
 195   host_item *h;
 196
 197   DEBUG(D_route) debug_printf("calling host %s\n", hostname);
 198
 199   host->name = hostname;
 200   host->address = NULL;
 201   host->port = PORT_NONE;
 202   host->mx = MX_NONE;
 203   host->next = NULL;
 204
 205   if (string_is_ip_address(host->name, NULL) != 0)
 206     host->address = host->name;
 207   else
 208     {
 209     int rc = host_find_byname(host, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, TRUE);
 210     if (rc == HOST_FIND_FAILED || rc == HOST_FIND_AGAIN) continue;
 211     }
 212
 213   /* Loop for possible multiple IP addresses for the given name. */
 214
 215   for (h = host; h != NULL; h = h->next)
 216     {
 217     int host_af, query_socket;
 218
 219     /* Skip any hosts for which we have no address */
 220
 221     if (h->address == NULL) continue;
 222
 223     /* Create a socket, for UDP or TCP, as configured. IPv6 addresses are
 224     detected by checking for a colon in the address. */
 225
 226     host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET;
 227     query_socket = ip_socket((ob->protocol == ip_udp)? SOCK_DGRAM:SOCK_STREAM,
 228       host_af);
 229     if (query_socket < 0)
 230       {
 231       if (ob->optional) return PASS;
 232       addr->message = string_sprintf("failed to create socket in %s router",
 233         rblock->name);
 234       return DEFER;
 235       }
 236
 237     /* Connect to the remote host, under a timeout. In fact, timeouts can occur
 238     here only for TCP calls; for a UDP socket, "connect" always works (the
 239     router will timeout later on the read call). */
 240
 241     if (ip_connect(query_socket, host_af, h->address,ob->port, ob->timeout) < 0)
 242       {
 243       close(query_socket);
 244       DEBUG(D_route)
 245         debug_printf("connection to %s failed: %s\n", h->address,
 246           strerror(errno));
 247       continue;
 248       }
 249
 250     /* Send the query. If it fails, just continue with the next address. */
 251
 252     if (send(query_socket, query, query_len, 0) < 0)
 253       {
 254       DEBUG(D_route) debug_printf("send to %s failed\n", h->address);
 255       (void)close(query_socket);
 256       continue;
 257       }
 258
 259     /* Read the response and close the socket. If the read fails, try the
 260     next IP address. */
 261
 262     count = ip_recv(query_socket, reply, sizeof(reply) - 1, ob->timeout);
 263     (void)close(query_socket);
 264     if (count <= 0)
 265       {
 266       DEBUG(D_route) debug_printf("%s from %s\n", (errno == ETIMEDOUT)?
 267         "timed out" : "recv failed", h->address);
 268       *reply = 0;
 269       continue;
 270       }
 271
 272     /* Success; break the loop */
 273
 274     reply[count] = 0;
 275     DEBUG(D_route) debug_printf("%s router received \"%s\" from %s\n",
 276       rblock->name, string_printing(reply), h->address);
 277     break;
 278     }
 279
 280   /* If h == NULL we have tried all the IP addresses and failed on all of them,
 281   so we must continue to try more host names. Otherwise we have succeeded. */
 282
 283   if (h != NULL) break;
 284   }
 285
 286
 287 /* If hostname is NULL, we have failed to find any host, or failed to
 288 connect to any of the IP addresses, or timed out while reading or writing to
 289 those we have connected to. In all cases, we must pass if optional and
 290 defer otherwise. */
 291
 292 if (hostname == NULL)
 293   {
 294   DEBUG(D_route) debug_printf("%s router failed to get anything\n", rblock->name);
 295   if (ob->optional) return PASS;
 296   addr->message = string_sprintf("%s router: failed to communicate with any "
 297     "host", rblock->name);
 298   return DEFER;
 299   }
 300
 301
 302 /* If a response pattern was supplied, match the returned string against it. A
 303 failure to match causes the router to decline. After a successful match, the
 304 numerical variables for expanding the rerouted address are set up. */
 305
 306 if (re != NULL)
 307   {
 308   if (!regex_match_and_setup(re, reply, 0, -1))
 309     {
 310     DEBUG(D_route) debug_printf("%s router: %s failed to match response %s\n",
 311       rblock->name, ob->response_pattern, reply);
 312     return DECLINE;
 313     }
 314   }
 315
 316
 317 /* If no response pattern was supplied, set up $0 as the response up to the
 318 first white space (if any). Also, if no query was specified, check that what
 319 follows the white space matches user@domain. */
 320
 321 else
 322   {
 323   int n = 0;
 324   while (reply[n] != 0 && !isspace(reply[n])) n++;
 325   expand_nmax = 0;
 326   expand_nstring[0] = reply;
 327   expand_nlength[0] = n;
 328
 329   if (ob->query == NULL)
 330     {
 331     int nn = n;
 332     while (isspace(reply[nn])) nn++;
 333     if (Ustrcmp(query + query_len/2 + 1, reply+nn) != 0)
 334       {
 335       DEBUG(D_route) debug_printf("%s router: failed to match identification "
 336         "in response %s\n", rblock->name, reply);
 337       return DECLINE;
 338       }
 339     }
 340
 341   reply[n] = 0;  /* Terminate for the default case */
 342   }
 343
 344 /* If an explicit rerouting string is specified, expand it. Otherwise, use
 345 what was sent back verbatim. */
 346
 347 if (ob->reroute != NULL)
 348   {
 349   reroute = expand_string(ob->reroute);
 350   expand_nmax = -1;
 351   if (reroute == NULL)
 352     {
 353     addr->message = string_sprintf("%s router: failed to expand %s: %s",
 354       rblock->name, ob->reroute, expand_string_message);
 355     return DEFER;
 356     }
 357   }
 358 else reroute = reply;
 359
 360 /* We should now have a new address in the form user@domain. */
 361
 362 domain = Ustrchr(reroute, '@');
 363 if (domain == NULL)
 364   {
 365   log_write(0, LOG_MAIN, "%s router: reroute string %s is not of the form "
 366     "user@domain", rblock->name, reroute);
 367   addr->message = string_sprintf("%s router: reroute string %s is not of the "
 368     "form user@domain", rblock->name, reroute);
 369   return DEFER;
 370   }
 371
 372 /* Create a child address with the old one as parent. Put the new address on
 373 the chain of new addressess. */
 374
 375 new_addr = deliver_make_addr(reroute, TRUE);
 376 new_addr->parent = addr;
 377
 378 copyflag(new_addr, addr, af_propagate);
 379 new_addr->p = addr->p;
 380
 381 if (addr->child_count == SHRT_MAX)
 382   log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
 383     "child addresses for <%s>", rblock->name, SHRT_MAX, addr->address);
 384 addr->child_count++;
 385 new_addr->next = *addr_new;
 386 *addr_new = new_addr;
 387
 388 /* Set up the errors address, if any, and the additional and removeable headers
 389 for this new address. */
 390
 391 rc = rf_get_errors_address(addr, rblock, verify, &(new_addr->p.errors_address));
 392 if (rc != OK) return rc;
 393
 394 rc = rf_get_munge_headers(addr, rblock, &(new_addr->p.extra_headers),
 395   &(new_addr->p.remove_headers));
 396 if (rc != OK) return rc;
 397
 398 return OK;
 399 }
 400
 401 /* End of routers/iplookup.c */