src/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;
 147 const uschar *listptr;
 148 uschar host_buffer[256];
 149 host_item *host = store_get(sizeof(host_item));
 150 address_item *new_addr;
 151 iplookup_router_options_block *ob =
 152   (iplookup_router_options_block *)(rblock->options_block);
 153 const pcre *re = ob->re_response_pattern;
 154 int count, query_len, rc;
 155 int sep = 0;
 156
 157 addr_local = addr_local;    /* Keep picky compilers happy */
 158 addr_remote = addr_remote;
 159 addr_succeed = addr_succeed;
 160 pw = pw;
 161
 162 DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
 163   rblock->name, addr->address, addr->domain);
 164
 165 reply = store_get(256);
 166
 167 /* Build the query string to send. If not explicitly given, a default of
 168 "user@domain user@domain" is used. */
 169
 170 if (ob->query == NULL)
 171   query = string_sprintf("%s@%s %s@%s", addr->local_part, addr->domain,
 172     addr->local_part, addr->domain);
 173 else
 174   {
 175   query = expand_string(ob->query);
 176   if (query == NULL)
 177     {
 178     addr->message = string_sprintf("%s router: failed to expand %s: %s",
 179       rblock->name, ob->query, expand_string_message);
 180     return DEFER;
 181     }
 182   }
 183
 184 query_len = Ustrlen(query);
 185 DEBUG(D_route) debug_printf("%s router query is \"%s\"\n", rblock->name,
 186   string_printing(query));
 187
 188 /* Now connect to the required port for each of the hosts in turn, until a
 189 response it received. Initialization insists on the port being set and there
 190 being a host list. */
 191
 192 listptr = ob->hosts;
 193 while ((hostname = string_nextinlist(&listptr, &sep, host_buffer,
 194        sizeof(host_buffer))) != NULL)
 195   {
 196   host_item *h;
 197
 198   DEBUG(D_route) debug_printf("calling host %s\n", hostname);
 199
 200   host->name = hostname;
 201   host->address = NULL;
 202   host->port = PORT_NONE;
 203   host->mx = MX_NONE;
 204   host->next = NULL;
 205
 206   if (string_is_ip_address(host->name, NULL) != 0)
 207     host->address = host->name;
 208   else
 209     {
 210     int rc = host_find_byname(host, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, TRUE);
 211     if (rc == HOST_FIND_FAILED || rc == HOST_FIND_AGAIN) continue;
 212     }
 213
 214   /* Loop for possible multiple IP addresses for the given name. */
 215
 216   for (h = host; h != NULL; h = h->next)
 217     {
 218     int host_af, query_socket;
 219
 220     /* Skip any hosts for which we have no address */
 221
 222     if (h->address == NULL) continue;
 223
 224     /* Create a socket, for UDP or TCP, as configured. IPv6 addresses are
 225     detected by checking for a colon in the address. */
 226
 227     host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET;
 228     query_socket = ip_socket((ob->protocol == ip_udp)? SOCK_DGRAM:SOCK_STREAM,
 229       host_af);
 230     if (query_socket < 0)
 231       {
 232       if (ob->optional) return PASS;
 233       addr->message = string_sprintf("failed to create socket in %s router",
 234         rblock->name);
 235       return DEFER;
 236       }
 237
 238     /* Connect to the remote host, under a timeout. In fact, timeouts can occur
 239     here only for TCP calls; for a UDP socket, "connect" always works (the
 240     router will timeout later on the read call). */
 241
 242     if (ip_connect(query_socket, host_af, h->address,ob->port, ob->timeout) < 0)
 243       {
 244       close(query_socket);
 245       DEBUG(D_route)
 246         debug_printf("connection to %s failed: %s\n", h->address,
 247           strerror(errno));
 248       continue;
 249       }
 250
 251     /* Send the query. If it fails, just continue with the next address. */
 252
 253     if (send(query_socket, query, query_len, 0) < 0)
 254       {
 255       DEBUG(D_route) debug_printf("send to %s failed\n", h->address);
 256       (void)close(query_socket);
 257       continue;
 258       }
 259
 260     /* Read the response and close the socket. If the read fails, try the
 261     next IP address. */
 262
 263     count = ip_recv(query_socket, reply, sizeof(reply) - 1, ob->timeout);
 264     (void)close(query_socket);
 265     if (count <= 0)
 266       {
 267       DEBUG(D_route) debug_printf("%s from %s\n", (errno == ETIMEDOUT)?
 268         "timed out" : "recv failed", h->address);
 269       *reply = 0;
 270       continue;
 271       }
 272
 273     /* Success; break the loop */
 274
 275     reply[count] = 0;
 276     DEBUG(D_route) debug_printf("%s router received \"%s\" from %s\n",
 277       rblock->name, string_printing(reply), h->address);
 278     break;
 279     }
 280
 281   /* If h == NULL we have tried all the IP addresses and failed on all of them,
 282   so we must continue to try more host names. Otherwise we have succeeded. */
 283
 284   if (h != NULL) break;
 285   }
 286
 287
 288 /* If hostname is NULL, we have failed to find any host, or failed to
 289 connect to any of the IP addresses, or timed out while reading or writing to
 290 those we have connected to. In all cases, we must pass if optional and
 291 defer otherwise. */
 292
 293 if (hostname == NULL)
 294   {
 295   DEBUG(D_route) debug_printf("%s router failed to get anything\n", rblock->name);
 296   if (ob->optional) return PASS;
 297   addr->message = string_sprintf("%s router: failed to communicate with any "
 298     "host", rblock->name);
 299   return DEFER;
 300   }
 301
 302
 303 /* If a response pattern was supplied, match the returned string against it. A
 304 failure to match causes the router to decline. After a successful match, the
 305 numerical variables for expanding the rerouted address are set up. */
 306
 307 if (re != NULL)
 308   {
 309   if (!regex_match_and_setup(re, reply, 0, -1))
 310     {
 311     DEBUG(D_route) debug_printf("%s router: %s failed to match response %s\n",
 312       rblock->name, ob->response_pattern, reply);
 313     return DECLINE;
 314     }
 315   }
 316
 317
 318 /* If no response pattern was supplied, set up $0 as the response up to the
 319 first white space (if any). Also, if no query was specified, check that what
 320 follows the white space matches user@domain. */
 321
 322 else
 323   {
 324   int n = 0;
 325   while (reply[n] != 0 && !isspace(reply[n])) n++;
 326   expand_nmax = 0;
 327   expand_nstring[0] = reply;
 328   expand_nlength[0] = n;
 329
 330   if (ob->query == NULL)
 331     {
 332     int nn = n;
 333     while (isspace(reply[nn])) nn++;
 334     if (Ustrcmp(query + query_len/2 + 1, reply+nn) != 0)
 335       {
 336       DEBUG(D_route) debug_printf("%s router: failed to match identification "
 337         "in response %s\n", rblock->name, reply);
 338       return DECLINE;
 339       }
 340     }
 341
 342   reply[n] = 0;  /* Terminate for the default case */
 343   }
 344
 345 /* If an explicit rerouting string is specified, expand it. Otherwise, use
 346 what was sent back verbatim. */
 347
 348 if (ob->reroute != NULL)
 349   {
 350   reroute = expand_string(ob->reroute);
 351   expand_nmax = -1;
 352   if (reroute == NULL)
 353     {
 354     addr->message = string_sprintf("%s router: failed to expand %s: %s",
 355       rblock->name, ob->reroute, expand_string_message);
 356     return DEFER;
 357     }
 358   }
 359 else reroute = reply;
 360
 361 /* We should now have a new address in the form user@domain. */
 362
 363 domain = Ustrchr(reroute, '@');
 364 if (domain == NULL)
 365   {
 366   log_write(0, LOG_MAIN, "%s router: reroute string %s is not of the form "
 367     "user@domain", rblock->name, reroute);
 368   addr->message = string_sprintf("%s router: reroute string %s is not of the "
 369     "form user@domain", rblock->name, reroute);
 370   return DEFER;
 371   }
 372
 373 /* Create a child address with the old one as parent. Put the new address on
 374 the chain of new addressess. */
 375
 376 new_addr = deliver_make_addr(reroute, TRUE);
 377 new_addr->parent = addr;
 378
 379 copyflag(new_addr, addr, af_propagate);
 380 new_addr->p = addr->p;
 381
 382 if (addr->child_count == SHRT_MAX)
 383   log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
 384     "child addresses for <%s>", rblock->name, SHRT_MAX, addr->address);
 385 addr->child_count++;
 386 new_addr->next = *addr_new;
 387 *addr_new = new_addr;
 388
 389 /* Set up the errors address, if any, and the additional and removeable headers
 390 for this new address. */
 391
 392 rc = rf_get_errors_address(addr, rblock, verify, &(new_addr->p.errors_address));
 393 if (rc != OK) return rc;
 394
 395 rc = rf_get_munge_headers(addr, rblock, &(new_addr->p.extra_headers),
 396   &(new_addr->p.remove_headers));
 397 if (rc != OK) return rc;
 398
 399 return OK;
 400 }
 401
 402 /* End of routers/iplookup.c */