| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2018 */ |
| 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 | |
| 48 | #ifdef MACRO_PREDEF |
| 49 | |
| 50 | /* Dummy entries */ |
| 51 | iplookup_router_options_block iplookup_router_option_defaults = {0}; |
| 52 | void iplookup_router_init(router_instance *rblock) {} |
| 53 | int iplookup_router_entry(router_instance *rblock, address_item *addr, |
| 54 | struct passwd *pw, int verify, address_item **addr_local, |
| 55 | address_item **addr_remote, address_item **addr_new, |
| 56 | address_item **addr_succeed) {return 0;} |
| 57 | |
| 58 | #else /*!MACRO_PREDEF*/ |
| 59 | |
| 60 | |
| 61 | /* Default private options block for the iplookup router. */ |
| 62 | |
| 63 | iplookup_router_options_block iplookup_router_option_defaults = { |
| 64 | -1, /* port */ |
| 65 | ip_udp, /* protocol */ |
| 66 | 5, /* timeout */ |
| 67 | NULL, /* protocol_name */ |
| 68 | NULL, /* hosts */ |
| 69 | NULL, /* query; NULL => local_part@domain */ |
| 70 | NULL, /* response_pattern; NULL => don't apply regex */ |
| 71 | NULL, /* reroute; NULL => just used returned data */ |
| 72 | NULL, /* re_response_pattern; compiled pattern */ |
| 73 | FALSE /* optional */ |
| 74 | }; |
| 75 | |
| 76 | |
| 77 | |
| 78 | /************************************************* |
| 79 | * Initialization entry point * |
| 80 | *************************************************/ |
| 81 | |
| 82 | /* Called for each instance, after its options have been read, to enable |
| 83 | consistency checks to be done, or anything else that needs to be set up. */ |
| 84 | |
| 85 | void |
| 86 | iplookup_router_init(router_instance *rblock) |
| 87 | { |
| 88 | iplookup_router_options_block *ob = |
| 89 | (iplookup_router_options_block *)(rblock->options_block); |
| 90 | |
| 91 | /* A port and a host list must be given */ |
| 92 | |
| 93 | if (ob->port < 0) |
| 94 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n " |
| 95 | "a port must be specified", rblock->name); |
| 96 | |
| 97 | if (ob->hosts == NULL) |
| 98 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n " |
| 99 | "a host list must be specified", rblock->name); |
| 100 | |
| 101 | /* Translate protocol name into value */ |
| 102 | |
| 103 | if (ob->protocol_name != NULL) |
| 104 | { |
| 105 | if (Ustrcmp(ob->protocol_name, "udp") == 0) ob->protocol = ip_udp; |
| 106 | else if (Ustrcmp(ob->protocol_name, "tcp") == 0) ob->protocol = ip_tcp; |
| 107 | else log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n " |
| 108 | "protocol not specified as udp or tcp", rblock->name); |
| 109 | } |
| 110 | |
| 111 | /* If a response pattern is given, compile it now to get the error early. */ |
| 112 | |
| 113 | if (ob->response_pattern != NULL) |
| 114 | ob->re_response_pattern = |
| 115 | regex_must_compile(ob->response_pattern, FALSE, TRUE); |
| 116 | } |
| 117 | |
| 118 | |
| 119 | |
| 120 | /************************************************* |
| 121 | * Main entry point * |
| 122 | *************************************************/ |
| 123 | |
| 124 | /* See local README for interface details. This router returns: |
| 125 | |
| 126 | DECLINE |
| 127 | . pattern or identification match on returned data failed |
| 128 | |
| 129 | DEFER |
| 130 | . failed to expand the query or rerouting string |
| 131 | . failed to create socket ("optional" not set) |
| 132 | . failed to find a host, failed to connect, timed out ("optional" not set) |
| 133 | . rerouting string is not in the form localpart@domain |
| 134 | . verifying the errors address caused a deferment or a big disaster such |
| 135 | as an expansion failure (rf_get_errors_address) |
| 136 | . expanding a headers_{add,remove} string caused a deferment or another |
| 137 | expansion error (rf_get_munge_headers) |
| 138 | |
| 139 | PASS |
| 140 | . failed to create socket ("optional" set) |
| 141 | . failed to find a host, failed to connect, timed out ("optional" set) |
| 142 | |
| 143 | OK |
| 144 | . new address added to addr_new |
| 145 | */ |
| 146 | |
| 147 | int |
| 148 | iplookup_router_entry( |
| 149 | router_instance *rblock, /* data for this instantiation */ |
| 150 | address_item *addr, /* address we are working on */ |
| 151 | struct passwd *pw, /* passwd entry after check_local_user */ |
| 152 | int verify, /* v_none/v_recipient/v_sender/v_expn */ |
| 153 | address_item **addr_local, /* add it to this if it's local */ |
| 154 | address_item **addr_remote, /* add it to this if it's remote */ |
| 155 | address_item **addr_new, /* put new addresses on here */ |
| 156 | address_item **addr_succeed) /* put old address here on success */ |
| 157 | { |
| 158 | uschar *query = NULL; |
| 159 | uschar *reply; |
| 160 | uschar *hostname, *reroute, *domain; |
| 161 | const uschar *listptr; |
| 162 | uschar host_buffer[256]; |
| 163 | host_item *host = store_get(sizeof(host_item)); |
| 164 | address_item *new_addr; |
| 165 | iplookup_router_options_block *ob = |
| 166 | (iplookup_router_options_block *)(rblock->options_block); |
| 167 | const pcre *re = ob->re_response_pattern; |
| 168 | int count, query_len, rc; |
| 169 | int sep = 0; |
| 170 | |
| 171 | addr_local = addr_local; /* Keep picky compilers happy */ |
| 172 | addr_remote = addr_remote; |
| 173 | addr_succeed = addr_succeed; |
| 174 | pw = pw; |
| 175 | |
| 176 | DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n", |
| 177 | rblock->name, addr->address, addr->domain); |
| 178 | |
| 179 | reply = store_get(256); |
| 180 | |
| 181 | /* Build the query string to send. If not explicitly given, a default of |
| 182 | "user@domain user@domain" is used. */ |
| 183 | |
| 184 | if (ob->query == NULL) |
| 185 | query = string_sprintf("%s@%s %s@%s", addr->local_part, addr->domain, |
| 186 | addr->local_part, addr->domain); |
| 187 | else |
| 188 | { |
| 189 | query = expand_string(ob->query); |
| 190 | if (query == NULL) |
| 191 | { |
| 192 | addr->message = string_sprintf("%s router: failed to expand %s: %s", |
| 193 | rblock->name, ob->query, expand_string_message); |
| 194 | return DEFER; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | query_len = Ustrlen(query); |
| 199 | DEBUG(D_route) debug_printf("%s router query is \"%s\"\n", rblock->name, |
| 200 | string_printing(query)); |
| 201 | |
| 202 | /* Now connect to the required port for each of the hosts in turn, until a |
| 203 | response it received. Initialization insists on the port being set and there |
| 204 | being a host list. */ |
| 205 | |
| 206 | listptr = ob->hosts; |
| 207 | while ((hostname = string_nextinlist(&listptr, &sep, host_buffer, |
| 208 | sizeof(host_buffer)))) |
| 209 | { |
| 210 | host_item *h; |
| 211 | |
| 212 | DEBUG(D_route) debug_printf("calling host %s\n", hostname); |
| 213 | |
| 214 | host->name = hostname; |
| 215 | host->address = NULL; |
| 216 | host->port = PORT_NONE; |
| 217 | host->mx = MX_NONE; |
| 218 | host->next = NULL; |
| 219 | |
| 220 | if (string_is_ip_address(host->name, NULL) != 0) |
| 221 | host->address = host->name; |
| 222 | else |
| 223 | { |
| 224 | /*XXX might want dnssec request/require on an iplookup router? */ |
| 225 | int rc = host_find_byname(host, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, TRUE); |
| 226 | if (rc == HOST_FIND_FAILED || rc == HOST_FIND_AGAIN) continue; |
| 227 | } |
| 228 | |
| 229 | /* Loop for possible multiple IP addresses for the given name. */ |
| 230 | |
| 231 | for (h = host; h; h = h->next) |
| 232 | { |
| 233 | int host_af; |
| 234 | client_conn_ctx query_cctx = {0}; |
| 235 | |
| 236 | /* Skip any hosts for which we have no address */ |
| 237 | |
| 238 | if (!h->address) continue; |
| 239 | |
| 240 | /* Create a socket, for UDP or TCP, as configured. IPv6 addresses are |
| 241 | detected by checking for a colon in the address. */ |
| 242 | |
| 243 | host_af = (Ustrchr(h->address, ':') != NULL)? AF_INET6 : AF_INET; |
| 244 | |
| 245 | query_cctx.sock = ip_socket(ob->protocol == ip_udp ? SOCK_DGRAM:SOCK_STREAM, |
| 246 | host_af); |
| 247 | if (query_cctx.sock < 0) |
| 248 | { |
| 249 | if (ob->optional) return PASS; |
| 250 | addr->message = string_sprintf("failed to create socket in %s router", |
| 251 | rblock->name); |
| 252 | return DEFER; |
| 253 | } |
| 254 | |
| 255 | /* Connect to the remote host, under a timeout. In fact, timeouts can occur |
| 256 | here only for TCP calls; for a UDP socket, "connect" always works (the |
| 257 | router will timeout later on the read call). */ |
| 258 | /*XXX could take advantage of TFO */ |
| 259 | |
| 260 | if (ip_connect(query_cctx.sock, host_af, h->address,ob->port, ob->timeout, |
| 261 | ob->protocol == ip_udp ? NULL : &tcp_fastopen_nodata) < 0) |
| 262 | { |
| 263 | close(query_cctx.sock); |
| 264 | DEBUG(D_route) |
| 265 | debug_printf("connection to %s failed: %s\n", h->address, |
| 266 | strerror(errno)); |
| 267 | continue; |
| 268 | } |
| 269 | |
| 270 | /* Send the query. If it fails, just continue with the next address. */ |
| 271 | |
| 272 | if (send(query_cctx.sock, query, query_len, 0) < 0) |
| 273 | { |
| 274 | DEBUG(D_route) debug_printf("send to %s failed\n", h->address); |
| 275 | (void)close(query_cctx.sock); |
| 276 | continue; |
| 277 | } |
| 278 | |
| 279 | /* Read the response and close the socket. If the read fails, try the |
| 280 | next IP address. */ |
| 281 | |
| 282 | count = ip_recv(&query_cctx, reply, sizeof(reply) - 1, ob->timeout); |
| 283 | (void)close(query_cctx.sock); |
| 284 | if (count <= 0) |
| 285 | { |
| 286 | DEBUG(D_route) debug_printf("%s from %s\n", (errno == ETIMEDOUT)? |
| 287 | "timed out" : "recv failed", h->address); |
| 288 | *reply = 0; |
| 289 | continue; |
| 290 | } |
| 291 | |
| 292 | /* Success; break the loop */ |
| 293 | |
| 294 | reply[count] = 0; |
| 295 | DEBUG(D_route) debug_printf("%s router received \"%s\" from %s\n", |
| 296 | rblock->name, string_printing(reply), h->address); |
| 297 | break; |
| 298 | } |
| 299 | |
| 300 | /* If h == NULL we have tried all the IP addresses and failed on all of them, |
| 301 | so we must continue to try more host names. Otherwise we have succeeded. */ |
| 302 | |
| 303 | if (h) break; |
| 304 | } |
| 305 | |
| 306 | |
| 307 | /* If hostname is NULL, we have failed to find any host, or failed to |
| 308 | connect to any of the IP addresses, or timed out while reading or writing to |
| 309 | those we have connected to. In all cases, we must pass if optional and |
| 310 | defer otherwise. */ |
| 311 | |
| 312 | if (hostname == NULL) |
| 313 | { |
| 314 | DEBUG(D_route) debug_printf("%s router failed to get anything\n", rblock->name); |
| 315 | if (ob->optional) return PASS; |
| 316 | addr->message = string_sprintf("%s router: failed to communicate with any " |
| 317 | "host", rblock->name); |
| 318 | return DEFER; |
| 319 | } |
| 320 | |
| 321 | |
| 322 | /* If a response pattern was supplied, match the returned string against it. A |
| 323 | failure to match causes the router to decline. After a successful match, the |
| 324 | numerical variables for expanding the rerouted address are set up. */ |
| 325 | |
| 326 | if (re != NULL) |
| 327 | { |
| 328 | if (!regex_match_and_setup(re, reply, 0, -1)) |
| 329 | { |
| 330 | DEBUG(D_route) debug_printf("%s router: %s failed to match response %s\n", |
| 331 | rblock->name, ob->response_pattern, reply); |
| 332 | return DECLINE; |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | |
| 337 | /* If no response pattern was supplied, set up $0 as the response up to the |
| 338 | first white space (if any). Also, if no query was specified, check that what |
| 339 | follows the white space matches user@domain. */ |
| 340 | |
| 341 | else |
| 342 | { |
| 343 | int n = 0; |
| 344 | while (reply[n] != 0 && !isspace(reply[n])) n++; |
| 345 | expand_nmax = 0; |
| 346 | expand_nstring[0] = reply; |
| 347 | expand_nlength[0] = n; |
| 348 | |
| 349 | if (ob->query == NULL) |
| 350 | { |
| 351 | int nn = n; |
| 352 | while (isspace(reply[nn])) nn++; |
| 353 | if (Ustrcmp(query + query_len/2 + 1, reply+nn) != 0) |
| 354 | { |
| 355 | DEBUG(D_route) debug_printf("%s router: failed to match identification " |
| 356 | "in response %s\n", rblock->name, reply); |
| 357 | return DECLINE; |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | reply[n] = 0; /* Terminate for the default case */ |
| 362 | } |
| 363 | |
| 364 | /* If an explicit rerouting string is specified, expand it. Otherwise, use |
| 365 | what was sent back verbatim. */ |
| 366 | |
| 367 | if (ob->reroute != NULL) |
| 368 | { |
| 369 | reroute = expand_string(ob->reroute); |
| 370 | expand_nmax = -1; |
| 371 | if (reroute == NULL) |
| 372 | { |
| 373 | addr->message = string_sprintf("%s router: failed to expand %s: %s", |
| 374 | rblock->name, ob->reroute, expand_string_message); |
| 375 | return DEFER; |
| 376 | } |
| 377 | } |
| 378 | else reroute = reply; |
| 379 | |
| 380 | /* We should now have a new address in the form user@domain. */ |
| 381 | |
| 382 | domain = Ustrchr(reroute, '@'); |
| 383 | if (domain == NULL) |
| 384 | { |
| 385 | log_write(0, LOG_MAIN, "%s router: reroute string %s is not of the form " |
| 386 | "user@domain", rblock->name, reroute); |
| 387 | addr->message = string_sprintf("%s router: reroute string %s is not of the " |
| 388 | "form user@domain", rblock->name, reroute); |
| 389 | return DEFER; |
| 390 | } |
| 391 | |
| 392 | /* Create a child address with the old one as parent. Put the new address on |
| 393 | the chain of new addressess. */ |
| 394 | |
| 395 | new_addr = deliver_make_addr(reroute, TRUE); |
| 396 | new_addr->parent = addr; |
| 397 | |
| 398 | new_addr->prop = addr->prop; |
| 399 | |
| 400 | if (addr->child_count == USHRT_MAX) |
| 401 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d " |
| 402 | "child addresses for <%s>", rblock->name, USHRT_MAX, addr->address); |
| 403 | addr->child_count++; |
| 404 | new_addr->next = *addr_new; |
| 405 | *addr_new = new_addr; |
| 406 | |
| 407 | /* Set up the errors address, if any, and the additional and removable headers |
| 408 | for this new address. */ |
| 409 | |
| 410 | rc = rf_get_errors_address(addr, rblock, verify, &new_addr->prop.errors_address); |
| 411 | if (rc != OK) return rc; |
| 412 | |
| 413 | rc = rf_get_munge_headers(addr, rblock, &new_addr->prop.extra_headers, |
| 414 | &new_addr->prop.remove_headers); |
| 415 | if (rc != OK) return rc; |
| 416 | |
| 417 | return OK; |
| 418 | } |
| 419 | |
| 420 | #endif /*!MACRO_PREDEF*/ |
| 421 | /* End of routers/iplookup.c */ |