| 1 | /* $Cambridge: exim/src/src/verify.c,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */ |
| 2 | |
| 3 | /************************************************* |
| 4 | * Exim - an Internet mail transport agent * |
| 5 | *************************************************/ |
| 6 | |
| 7 | /* Copyright (c) University of Cambridge 1995 - 2004 */ |
| 8 | /* See the file NOTICE for conditions of use and distribution. */ |
| 9 | |
| 10 | /* Functions concerned with verifying things. The original code for callout |
| 11 | caching was contributed by Kevin Fleming (but I hacked it around a bit). */ |
| 12 | |
| 13 | |
| 14 | #include "exim.h" |
| 15 | |
| 16 | |
| 17 | /* Structure for caching DNSBL lookups */ |
| 18 | |
| 19 | typedef struct dnsbl_cache_block { |
| 20 | dns_address *rhs; |
| 21 | uschar *text; |
| 22 | int rc; |
| 23 | BOOL text_set; |
| 24 | } dnsbl_cache_block; |
| 25 | |
| 26 | |
| 27 | /* Anchor for DNSBL cache */ |
| 28 | |
| 29 | static tree_node *dnsbl_cache = NULL; |
| 30 | |
| 31 | |
| 32 | |
| 33 | /************************************************* |
| 34 | * Retrieve a callout cache record * |
| 35 | *************************************************/ |
| 36 | |
| 37 | /* If a record exists, check whether it has expired. |
| 38 | |
| 39 | Arguments: |
| 40 | dbm_file an open hints file |
| 41 | key the record key |
| 42 | type "address" or "domain" |
| 43 | positive_expire expire time for positive records |
| 44 | negative_expire expire time for negative records |
| 45 | |
| 46 | Returns: the cache record if a non-expired one exists, else NULL |
| 47 | */ |
| 48 | |
| 49 | static dbdata_callout_cache * |
| 50 | get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type, |
| 51 | int positive_expire, int negative_expire) |
| 52 | { |
| 53 | BOOL negative; |
| 54 | int length, expire; |
| 55 | time_t now; |
| 56 | dbdata_callout_cache *cache_record; |
| 57 | |
| 58 | cache_record = dbfn_read_with_length(dbm_file, key, &length); |
| 59 | |
| 60 | if (cache_record == NULL) |
| 61 | { |
| 62 | HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type); |
| 63 | return NULL; |
| 64 | } |
| 65 | |
| 66 | /* We treat a record as "negative" if its result field is not positive, or if |
| 67 | it is a domain record and the postmaster field is negative. */ |
| 68 | |
| 69 | negative = cache_record->result != ccache_accept || |
| 70 | (type[0] == 'd' && cache_record->postmaster_result == ccache_reject); |
| 71 | expire = negative? negative_expire : positive_expire; |
| 72 | now = time(NULL); |
| 73 | |
| 74 | if (now - cache_record->time_stamp > expire) |
| 75 | { |
| 76 | HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type); |
| 77 | return NULL; |
| 78 | } |
| 79 | |
| 80 | /* If this is a non-reject domain record, check for the obsolete format version |
| 81 | that doesn't have the postmaster and random timestamps, by looking at the |
| 82 | length. If so, copy it to a new-style block, replicating the record's |
| 83 | timestamp. Then check the additional timestamps. (There's no point wasting |
| 84 | effort if connections are rejected.) */ |
| 85 | |
| 86 | if (type[0] == 'd' && cache_record->result != ccache_reject) |
| 87 | { |
| 88 | if (length == sizeof(dbdata_callout_cache_obs)) |
| 89 | { |
| 90 | dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache)); |
| 91 | memcpy(new, cache_record, length); |
| 92 | new->postmaster_stamp = new->random_stamp = new->time_stamp; |
| 93 | cache_record = new; |
| 94 | } |
| 95 | |
| 96 | if (now - cache_record->postmaster_stamp > expire) |
| 97 | cache_record->postmaster_result = ccache_unknown; |
| 98 | |
| 99 | if (now - cache_record->random_stamp > expire) |
| 100 | cache_record->random_result = ccache_unknown; |
| 101 | } |
| 102 | |
| 103 | HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type); |
| 104 | return cache_record; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | |
| 109 | /************************************************* |
| 110 | * Do callout verification for an address * |
| 111 | *************************************************/ |
| 112 | |
| 113 | /* This function is called from verify_address() when the address has routed to |
| 114 | a host list, and a callout has been requested. Callouts are expensive; that is |
| 115 | why a cache is used to improve the efficiency. |
| 116 | |
| 117 | Arguments: |
| 118 | addr the address that's been routed |
| 119 | host_list the list of hosts to try |
| 120 | tf the transport feedback block |
| 121 | |
| 122 | ifstring "interface" option from transport, or NULL |
| 123 | portstring "port" option from transport, or NULL |
| 124 | protocolstring "protocol" option from transport, or NULL |
| 125 | callout the per-command callout timeout |
| 126 | callout_overall the overall callout timeout (if < 0; use 4*callout) |
| 127 | options the verification options - these bits are used: |
| 128 | vopt_is_recipient => this is a recipient address |
| 129 | vopt_callout_no_cache => don't use callout cache |
| 130 | vopt_callout_random => do the "random" thing |
| 131 | vopt_callout_recipsender => use real sender for recipient |
| 132 | vopt_callout_recippmaster => use postmaster for recipient |
| 133 | se_mailfrom MAIL FROM address for sender verify; NULL => "" |
| 134 | pm_mailfrom if non-NULL, do the postmaster check with this sender |
| 135 | |
| 136 | Returns: OK/FAIL/DEFER |
| 137 | */ |
| 138 | |
| 139 | static int |
| 140 | do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, |
| 141 | int callout, int callout_overall, int options, uschar *se_mailfrom, |
| 142 | uschar *pm_mailfrom) |
| 143 | { |
| 144 | BOOL is_recipient = (options & vopt_is_recipient) != 0; |
| 145 | BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0; |
| 146 | BOOL callout_random = (options & vopt_callout_random) != 0; |
| 147 | |
| 148 | int yield = OK; |
| 149 | BOOL done = FALSE; |
| 150 | uschar *address_key; |
| 151 | uschar *from_address; |
| 152 | uschar *random_local_part = NULL; |
| 153 | open_db dbblock; |
| 154 | open_db *dbm_file = NULL; |
| 155 | dbdata_callout_cache new_domain_record; |
| 156 | dbdata_callout_cache_address new_address_record; |
| 157 | host_item *host; |
| 158 | time_t callout_start_time; |
| 159 | |
| 160 | new_domain_record.result = ccache_unknown; |
| 161 | new_domain_record.postmaster_result = ccache_unknown; |
| 162 | new_domain_record.random_result = ccache_unknown; |
| 163 | |
| 164 | memset(&new_address_record, 0, sizeof(new_address_record)); |
| 165 | |
| 166 | /* For a recipient callout, the key used for the address cache record must |
| 167 | include the sender address if we are using the real sender in the callout, |
| 168 | because that may influence the result of the callout. */ |
| 169 | |
| 170 | address_key = addr->address; |
| 171 | from_address = US""; |
| 172 | |
| 173 | if (is_recipient) |
| 174 | { |
| 175 | if ((options & vopt_callout_recipsender) != 0) |
| 176 | { |
| 177 | address_key = string_sprintf("%s/<%s>", addr->address, sender_address); |
| 178 | from_address = sender_address; |
| 179 | } |
| 180 | else if ((options & vopt_callout_recippmaster) != 0) |
| 181 | { |
| 182 | address_key = string_sprintf("%s/<postmaster@%s>", addr->address, |
| 183 | qualify_domain_sender); |
| 184 | from_address = string_sprintf("postmaster@%s", qualify_domain_sender); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | /* For a sender callout, we must adjust the key if the mailfrom address is not |
| 189 | empty. */ |
| 190 | |
| 191 | else |
| 192 | { |
| 193 | from_address = (se_mailfrom == NULL)? US"" : se_mailfrom; |
| 194 | if (from_address[0] != 0) |
| 195 | address_key = string_sprintf("%s/<%s>", addr->address, from_address); |
| 196 | } |
| 197 | |
| 198 | /* Open the callout cache database, it it exists, for reading only at this |
| 199 | stage, unless caching has been disabled. */ |
| 200 | |
| 201 | if (callout_no_cache) |
| 202 | { |
| 203 | HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n"); |
| 204 | } |
| 205 | else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL) |
| 206 | { |
| 207 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); |
| 208 | } |
| 209 | |
| 210 | /* If a cache database is available see if we can avoid the need to do an |
| 211 | actual callout by making use of previously-obtained data. */ |
| 212 | |
| 213 | if (dbm_file != NULL) |
| 214 | { |
| 215 | dbdata_callout_cache_address *cache_address_record; |
| 216 | dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file, |
| 217 | addr->domain, US"domain", |
| 218 | callout_cache_domain_positive_expire, |
| 219 | callout_cache_domain_negative_expire); |
| 220 | |
| 221 | /* If an unexpired cache record was found for this domain, see if the callout |
| 222 | process can be short-circuited. */ |
| 223 | |
| 224 | if (cache_record != NULL) |
| 225 | { |
| 226 | /* If an early command (up to and including MAIL FROM:<>) was rejected, |
| 227 | there is no point carrying on. The callout fails. */ |
| 228 | |
| 229 | if (cache_record->result == ccache_reject) |
| 230 | { |
| 231 | setflag(addr, af_verify_nsfail); |
| 232 | HDEBUG(D_verify) |
| 233 | debug_printf("callout cache: domain gave initial rejection, or " |
| 234 | "does not accept HELO or MAIL FROM:<>\n"); |
| 235 | setflag(addr, af_verify_nsfail); |
| 236 | addr->user_message = US"(result of an earlier callout reused)."; |
| 237 | yield = FAIL; |
| 238 | goto END_CALLOUT; |
| 239 | } |
| 240 | |
| 241 | /* If a previous check on a "random" local part was accepted, we assume |
| 242 | that the server does not do any checking on local parts. There is therefore |
| 243 | no point in doing the callout, because it will always be successful. If a |
| 244 | random check previously failed, arrange not to do it again, but preserve |
| 245 | the data in the new record. If a random check is required but hasn't been |
| 246 | done, skip the remaining cache processing. */ |
| 247 | |
| 248 | if (callout_random) switch(cache_record->random_result) |
| 249 | { |
| 250 | case ccache_accept: |
| 251 | HDEBUG(D_verify) |
| 252 | debug_printf("callout cache: domain accepts random addresses\n"); |
| 253 | goto END_CALLOUT; /* Default yield is OK */ |
| 254 | |
| 255 | case ccache_reject: |
| 256 | HDEBUG(D_verify) |
| 257 | debug_printf("callout cache: domain rejects random addresses\n"); |
| 258 | callout_random = FALSE; |
| 259 | new_domain_record.random_result = ccache_reject; |
| 260 | new_domain_record.random_stamp = cache_record->random_stamp; |
| 261 | break; |
| 262 | |
| 263 | default: |
| 264 | HDEBUG(D_verify) |
| 265 | debug_printf("callout cache: need to check random address handling " |
| 266 | "(not cached or cache expired)\n"); |
| 267 | goto END_CACHE; |
| 268 | } |
| 269 | |
| 270 | /* If a postmaster check is requested, but there was a previous failure, |
| 271 | there is again no point in carrying on. If a postmaster check is required, |
| 272 | but has not been done before, we are going to have to do a callout, so skip |
| 273 | remaining cache processing. */ |
| 274 | |
| 275 | if (pm_mailfrom != NULL) |
| 276 | { |
| 277 | if (cache_record->postmaster_result == ccache_reject) |
| 278 | { |
| 279 | setflag(addr, af_verify_pmfail); |
| 280 | HDEBUG(D_verify) |
| 281 | debug_printf("callout cache: domain does not accept " |
| 282 | "RCPT TO:<postmaster@domain>\n"); |
| 283 | yield = FAIL; |
| 284 | setflag(addr, af_verify_pmfail); |
| 285 | addr->user_message = US"(result of earlier verification reused)."; |
| 286 | goto END_CALLOUT; |
| 287 | } |
| 288 | if (cache_record->postmaster_result == ccache_unknown) |
| 289 | { |
| 290 | HDEBUG(D_verify) |
| 291 | debug_printf("callout cache: need to check RCPT " |
| 292 | "TO:<postmaster@domain> (not cached or cache expired)\n"); |
| 293 | goto END_CACHE; |
| 294 | } |
| 295 | |
| 296 | /* If cache says OK, set pm_mailfrom NULL to prevent a redundant |
| 297 | postmaster check if the address itself has to be checked. Also ensure |
| 298 | that the value in the cache record is preserved (with its old timestamp). |
| 299 | */ |
| 300 | |
| 301 | HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT " |
| 302 | "TO:<postmaster@domain>\n"); |
| 303 | pm_mailfrom = NULL; |
| 304 | new_domain_record.postmaster_result = ccache_accept; |
| 305 | new_domain_record.postmaster_stamp = cache_record->postmaster_stamp; |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | /* We can't give a result based on information about the domain. See if there |
| 310 | is an unexpired cache record for this specific address (combined with the |
| 311 | sender address if we are doing a recipient callout with a non-empty sender). |
| 312 | */ |
| 313 | |
| 314 | cache_address_record = (dbdata_callout_cache_address *) |
| 315 | get_callout_cache_record(dbm_file, |
| 316 | address_key, US"address", |
| 317 | callout_cache_positive_expire, |
| 318 | callout_cache_negative_expire); |
| 319 | |
| 320 | if (cache_address_record != NULL) |
| 321 | { |
| 322 | if (cache_address_record->result == ccache_accept) |
| 323 | { |
| 324 | HDEBUG(D_verify) |
| 325 | debug_printf("callout cache: address record is positive\n"); |
| 326 | } |
| 327 | else |
| 328 | { |
| 329 | HDEBUG(D_verify) |
| 330 | debug_printf("callout cache: address record is negative\n"); |
| 331 | addr->user_message = US"Previous (cached) callout verification failure"; |
| 332 | yield = FAIL; |
| 333 | } |
| 334 | goto END_CALLOUT; |
| 335 | } |
| 336 | |
| 337 | /* Close the cache database while we actually do the callout for real. */ |
| 338 | |
| 339 | END_CACHE: |
| 340 | dbfn_close(dbm_file); |
| 341 | dbm_file = NULL; |
| 342 | } |
| 343 | |
| 344 | /* The information wasn't available in the cache, so we have to do a real |
| 345 | callout and save the result in the cache for next time, unless no_cache is set, |
| 346 | or unless we have a previously cached negative random result. If we are to test |
| 347 | with a random local part, ensure that such a local part is available. If not, |
| 348 | log the fact, but carry on without randomming. */ |
| 349 | |
| 350 | if (callout_random && callout_random_local_part != NULL) |
| 351 | { |
| 352 | random_local_part = expand_string(callout_random_local_part); |
| 353 | if (random_local_part == NULL) |
| 354 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 355 | "callout_random_local_part: %s", expand_string_message); |
| 356 | } |
| 357 | |
| 358 | /* Default the overall callout timeout if not set, and record the time we are |
| 359 | starting so that we can enforce it. */ |
| 360 | |
| 361 | if (callout_overall < 0) callout_overall = 4 * callout; |
| 362 | callout_start_time = time(NULL); |
| 363 | |
| 364 | /* Now make connections to the hosts and do real callouts. The list of hosts |
| 365 | is passed in as an argument. */ |
| 366 | |
| 367 | for (host = host_list; host != NULL && !done; host = host->next) |
| 368 | { |
| 369 | smtp_inblock inblock; |
| 370 | smtp_outblock outblock; |
| 371 | int host_af; |
| 372 | int port = 25; |
| 373 | uschar *helo = US"HELO"; |
| 374 | uschar *interface = NULL; /* Outgoing interface to use; NULL => any */ |
| 375 | uschar inbuffer[4096]; |
| 376 | uschar outbuffer[1024]; |
| 377 | uschar responsebuffer[4096]; |
| 378 | |
| 379 | clearflag(addr, af_verify_pmfail); /* postmaster callout flag */ |
| 380 | clearflag(addr, af_verify_nsfail); /* null sender callout flag */ |
| 381 | |
| 382 | /* Skip this host if we don't have an IP address for it. */ |
| 383 | |
| 384 | if (host->address == NULL) |
| 385 | { |
| 386 | DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n", |
| 387 | host->name); |
| 388 | continue; |
| 389 | } |
| 390 | |
| 391 | /* Check the overall callout timeout */ |
| 392 | |
| 393 | if (time(NULL) - callout_start_time >= callout_overall) |
| 394 | { |
| 395 | HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n"); |
| 396 | break; |
| 397 | } |
| 398 | |
| 399 | /* Set IPv4 or IPv6 */ |
| 400 | |
| 401 | host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6; |
| 402 | |
| 403 | /* Expand and interpret the interface and port strings. This has to |
| 404 | be delayed till now, because they may expand differently for different |
| 405 | hosts. If there's a failure, log it, but carry on with the defaults. */ |
| 406 | |
| 407 | deliver_host = host->name; |
| 408 | deliver_host_address = host->address; |
| 409 | if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface, |
| 410 | US"callout") || |
| 411 | !smtp_get_port(tf->port, addr, &port, US"callout")) |
| 412 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address, |
| 413 | addr->message); |
| 414 | deliver_host = deliver_host_address = NULL; |
| 415 | |
| 416 | /* Set HELO string according to the protocol */ |
| 417 | |
| 418 | if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO"; |
| 419 | |
| 420 | HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port); |
| 421 | |
| 422 | /* Set up the buffer for reading SMTP response packets. */ |
| 423 | |
| 424 | inblock.buffer = inbuffer; |
| 425 | inblock.buffersize = sizeof(inbuffer); |
| 426 | inblock.ptr = inbuffer; |
| 427 | inblock.ptrend = inbuffer; |
| 428 | |
| 429 | /* Set up the buffer for holding SMTP commands while pipelining */ |
| 430 | |
| 431 | outblock.buffer = outbuffer; |
| 432 | outblock.buffersize = sizeof(outbuffer); |
| 433 | outblock.ptr = outbuffer; |
| 434 | outblock.cmd_count = 0; |
| 435 | outblock.authenticating = FALSE; |
| 436 | |
| 437 | /* Connect to the host; on failure, just loop for the next one, but we |
| 438 | set the error for the last one. */ |
| 439 | |
| 440 | inblock.sock = outblock.sock = |
| 441 | smtp_connect(host, host_af, port, interface, callout, TRUE); |
| 442 | if (inblock.sock < 0) |
| 443 | { |
| 444 | addr->message = string_sprintf("could not connect to %s [%s]: %s", |
| 445 | host->name, host->address, strerror(errno)); |
| 446 | continue; |
| 447 | } |
| 448 | |
| 449 | /* Wait for initial response, and then run the initial SMTP commands. The |
| 450 | smtp_write_command() function leaves its command in big_buffer. This is |
| 451 | used in error responses. Initialize it in case the connection is |
| 452 | rejected. */ |
| 453 | |
| 454 | Ustrcpy(big_buffer, "initial connection"); |
| 455 | |
| 456 | done = |
| 457 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 458 | '2', callout) && |
| 459 | |
| 460 | smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo, |
| 461 | smtp_active_hostname) >= 0 && |
| 462 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 463 | '2', callout) && |
| 464 | |
| 465 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n", |
| 466 | from_address) >= 0 && |
| 467 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 468 | '2', callout); |
| 469 | |
| 470 | /* If the host gave an initial error, or does not accept HELO or MAIL |
| 471 | FROM:<>, arrange to cache this information, but don't record anything for an |
| 472 | I/O error or a defer. Do not cache rejections when a non-empty sender has |
| 473 | been used, because that blocks the whole domain for all senders. */ |
| 474 | |
| 475 | if (!done) |
| 476 | { |
| 477 | if (errno == 0 && responsebuffer[0] == '5') |
| 478 | { |
| 479 | setflag(addr, af_verify_nsfail); |
| 480 | if (from_address[0] == 0) new_domain_record.result = ccache_reject; |
| 481 | } |
| 482 | } |
| 483 | |
| 484 | /* Otherwise, proceed to check a "random" address (if required), then the |
| 485 | given address, and the postmaster address (if required). Between each check, |
| 486 | issue RSET, because some servers accept only one recipient after MAIL |
| 487 | FROM:<>. */ |
| 488 | |
| 489 | else |
| 490 | { |
| 491 | new_domain_record.result = ccache_accept; |
| 492 | |
| 493 | /* Do the random local part check first */ |
| 494 | |
| 495 | if (random_local_part != NULL) |
| 496 | { |
| 497 | uschar randombuffer[1024]; |
| 498 | BOOL random_ok = |
| 499 | smtp_write_command(&outblock, FALSE, |
| 500 | "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part, |
| 501 | addr->domain) >= 0 && |
| 502 | smtp_read_response(&inblock, randombuffer, |
| 503 | sizeof(randombuffer), '2', callout); |
| 504 | |
| 505 | /* Remember when we last did a random test */ |
| 506 | |
| 507 | new_domain_record.random_stamp = time(NULL); |
| 508 | |
| 509 | /* If accepted, we aren't going to do any further tests below. */ |
| 510 | |
| 511 | if (random_ok) |
| 512 | { |
| 513 | new_domain_record.random_result = ccache_accept; |
| 514 | } |
| 515 | |
| 516 | /* Otherwise, cache a real negative response, and get back to the right |
| 517 | state to send RCPT. Unless there's some problem such as a dropped |
| 518 | connection, we expect to succeed, because the commands succeeded above. */ |
| 519 | |
| 520 | else if (errno == 0) |
| 521 | { |
| 522 | if (randombuffer[0] == '5') |
| 523 | new_domain_record.random_result = ccache_reject; |
| 524 | |
| 525 | done = |
| 526 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && |
| 527 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 528 | '2', callout) && |
| 529 | |
| 530 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 && |
| 531 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 532 | '2', callout); |
| 533 | } |
| 534 | else done = FALSE; /* Some timeout/connection problem */ |
| 535 | } /* Random check */ |
| 536 | |
| 537 | /* If the host is accepting all local parts, as determined by the "random" |
| 538 | check, we don't need to waste time doing any further checking. */ |
| 539 | |
| 540 | if (new_domain_record.random_result != ccache_accept && done) |
| 541 | { |
| 542 | done = |
| 543 | smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n", |
| 544 | addr->address) >= 0 && |
| 545 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 546 | '2', callout); |
| 547 | |
| 548 | if (done) |
| 549 | new_address_record.result = ccache_accept; |
| 550 | else if (errno == 0 && responsebuffer[0] == '5') |
| 551 | new_address_record.result = ccache_reject; |
| 552 | |
| 553 | /* Do postmaster check if requested */ |
| 554 | |
| 555 | if (done && pm_mailfrom != NULL) |
| 556 | { |
| 557 | done = |
| 558 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && |
| 559 | smtp_read_response(&inblock, responsebuffer, |
| 560 | sizeof(responsebuffer), '2', callout) && |
| 561 | |
| 562 | smtp_write_command(&outblock, FALSE, |
| 563 | "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 && |
| 564 | smtp_read_response(&inblock, responsebuffer, |
| 565 | sizeof(responsebuffer), '2', callout) && |
| 566 | |
| 567 | smtp_write_command(&outblock, FALSE, |
| 568 | "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 && |
| 569 | smtp_read_response(&inblock, responsebuffer, |
| 570 | sizeof(responsebuffer), '2', callout); |
| 571 | |
| 572 | new_domain_record.postmaster_stamp = time(NULL); |
| 573 | |
| 574 | if (done) |
| 575 | new_domain_record.postmaster_result = ccache_accept; |
| 576 | else if (errno == 0 && responsebuffer[0] == '5') |
| 577 | { |
| 578 | setflag(addr, af_verify_pmfail); |
| 579 | new_domain_record.postmaster_result = ccache_reject; |
| 580 | } |
| 581 | } |
| 582 | } /* Random not accepted */ |
| 583 | } /* MAIL FROM:<> accepted */ |
| 584 | |
| 585 | /* For any failure of the main check, other than a negative response, we just |
| 586 | close the connection and carry on. We can identify a negative response by the |
| 587 | fact that errno is zero. For I/O errors it will be non-zero |
| 588 | |
| 589 | Set up different error texts for logging and for sending back to the caller |
| 590 | as an SMTP response. Log in all cases, using a one-line format. For sender |
| 591 | callouts, give a full response to the caller, but for recipient callouts, |
| 592 | don't give the IP address because this may be an internal host whose identity |
| 593 | is not to be widely broadcast. */ |
| 594 | |
| 595 | if (!done) |
| 596 | { |
| 597 | if (errno == ETIMEDOUT) |
| 598 | { |
| 599 | HDEBUG(D_verify) debug_printf("SMTP timeout\n"); |
| 600 | } |
| 601 | else if (errno == 0) |
| 602 | { |
| 603 | if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped"); |
| 604 | |
| 605 | addr->message = |
| 606 | string_sprintf("response to \"%s\" from %s [%s] was: %s", |
| 607 | big_buffer, host->name, host->address, |
| 608 | string_printing(responsebuffer)); |
| 609 | |
| 610 | addr->user_message = is_recipient? |
| 611 | string_sprintf("Callout verification failed:\n%s", responsebuffer) |
| 612 | : |
| 613 | string_sprintf("Called: %s\nSent: %s\nResponse: %s", |
| 614 | host->address, big_buffer, responsebuffer); |
| 615 | |
| 616 | /* Hard rejection ends the process */ |
| 617 | |
| 618 | if (responsebuffer[0] == '5') /* Address rejected */ |
| 619 | { |
| 620 | yield = FAIL; |
| 621 | done = TRUE; |
| 622 | } |
| 623 | } |
| 624 | } |
| 625 | |
| 626 | /* End the SMTP conversation and close the connection. */ |
| 627 | |
| 628 | (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n"); |
| 629 | close(inblock.sock); |
| 630 | } /* Loop through all hosts, while !done */ |
| 631 | |
| 632 | /* If we get here with done == TRUE, a successful callout happened, and yield |
| 633 | will be set OK or FAIL according to the response to the RCPT command. |
| 634 | Otherwise, we looped through the hosts but couldn't complete the business. |
| 635 | However, there may be domain-specific information to cache in both cases. |
| 636 | |
| 637 | The value of the result field in the new_domain record is ccache_unknown if |
| 638 | there was an error before or with MAIL FROM:<>, and errno was not zero, |
| 639 | implying some kind of I/O error. We don't want to write the cache in that case. |
| 640 | Otherwise the value is ccache_accept or ccache_reject. */ |
| 641 | |
| 642 | if (!callout_no_cache && new_domain_record.result != ccache_unknown) |
| 643 | { |
| 644 | if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)) |
| 645 | == NULL) |
| 646 | { |
| 647 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); |
| 648 | } |
| 649 | else |
| 650 | { |
| 651 | (void)dbfn_write(dbm_file, addr->domain, &new_domain_record, |
| 652 | (int)sizeof(dbdata_callout_cache)); |
| 653 | HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n" |
| 654 | " result=%d postmaster=%d random=%d\n", |
| 655 | new_domain_record.result, |
| 656 | new_domain_record.postmaster_result, |
| 657 | new_domain_record.random_result); |
| 658 | } |
| 659 | } |
| 660 | |
| 661 | /* If a definite result was obtained for the callout, cache it unless caching |
| 662 | is disabled. */ |
| 663 | |
| 664 | if (done) |
| 665 | { |
| 666 | if (!callout_no_cache && new_address_record.result != ccache_unknown) |
| 667 | { |
| 668 | if (dbm_file == NULL) |
| 669 | dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); |
| 670 | if (dbm_file == NULL) |
| 671 | { |
| 672 | HDEBUG(D_verify) debug_printf("no callout cache available\n"); |
| 673 | } |
| 674 | else |
| 675 | { |
| 676 | (void)dbfn_write(dbm_file, address_key, &new_address_record, |
| 677 | (int)sizeof(dbdata_callout_cache_address)); |
| 678 | HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n", |
| 679 | (new_address_record.result == ccache_accept)? "positive" : "negative"); |
| 680 | } |
| 681 | } |
| 682 | } /* done */ |
| 683 | |
| 684 | /* Failure to connect to any host, or any response other than 2xx or 5xx is a |
| 685 | temporary error. If there was only one host, and a response was received, leave |
| 686 | it alone if supplying details. Otherwise, give a generic response. */ |
| 687 | |
| 688 | else /* !done */ |
| 689 | { |
| 690 | uschar *dullmsg = string_sprintf("Could not complete %s verify callout", |
| 691 | is_recipient? "recipient" : "sender"); |
| 692 | yield = DEFER; |
| 693 | |
| 694 | if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg; |
| 695 | |
| 696 | addr->user_message = (!smtp_return_error_details)? dullmsg : |
| 697 | string_sprintf("%s for <%s>.\n" |
| 698 | "The mail server(s) for the domain may be temporarily unreachable, or\n" |
| 699 | "they may be permanently unreachable from this server. In the latter case,\n%s", |
| 700 | dullmsg, addr->address, |
| 701 | is_recipient? |
| 702 | "the address will never be accepted." |
| 703 | : |
| 704 | "you need to change the address or create an MX record for its domain\n" |
| 705 | "if it is supposed to be generally accessible from the Internet.\n" |
| 706 | "Talk to your mail administrator for details."); |
| 707 | |
| 708 | /* Force a specific error code */ |
| 709 | |
| 710 | addr->basic_errno = ERRNO_CALLOUTDEFER; |
| 711 | } |
| 712 | |
| 713 | /* Come here from within the cache-reading code on fast-track exit. */ |
| 714 | |
| 715 | END_CALLOUT: |
| 716 | if (dbm_file != NULL) dbfn_close(dbm_file); |
| 717 | return yield; |
| 718 | } |
| 719 | |
| 720 | |
| 721 | |
| 722 | /************************************************* |
| 723 | * Copy error to toplevel address * |
| 724 | *************************************************/ |
| 725 | |
| 726 | /* This function is used when a verify fails or defers, to ensure that the |
| 727 | failure or defer information is in the original toplevel address. This applies |
| 728 | when an address is redirected to a single new address, and the failure or |
| 729 | deferral happens to the child address. |
| 730 | |
| 731 | Arguments: |
| 732 | vaddr the verify address item |
| 733 | addr the final address item |
| 734 | yield FAIL or DEFER |
| 735 | |
| 736 | Returns: the value of YIELD |
| 737 | */ |
| 738 | |
| 739 | static int |
| 740 | copy_error(address_item *vaddr, address_item *addr, int yield) |
| 741 | { |
| 742 | if (addr != vaddr) |
| 743 | { |
| 744 | vaddr->message = addr->message; |
| 745 | vaddr->user_message = addr->user_message; |
| 746 | vaddr->basic_errno = addr->basic_errno; |
| 747 | vaddr->more_errno = addr->more_errno; |
| 748 | } |
| 749 | return yield; |
| 750 | } |
| 751 | |
| 752 | |
| 753 | |
| 754 | |
| 755 | /************************************************* |
| 756 | * Verify an email address * |
| 757 | *************************************************/ |
| 758 | |
| 759 | /* This function is used both for verification (-bv and at other times) and |
| 760 | address testing (-bt), which is indicated by address_test_mode being set. |
| 761 | |
| 762 | Arguments: |
| 763 | vaddr contains the address to verify; the next field in this block |
| 764 | must be NULL |
| 765 | f if not NULL, write the result to this file |
| 766 | options various option bits: |
| 767 | vopt_fake_sender => this sender verify is not for the real |
| 768 | sender (it was verify=sender=xxxx or an address from a |
| 769 | header line) - rewriting must not change sender_address |
| 770 | vopt_is_recipient => this is a recipient address, otherwise |
| 771 | it's a sender address - this affects qualification and |
| 772 | rewriting and messages from callouts |
| 773 | vopt_qualify => qualify an unqualified address; else error |
| 774 | vopt_expn => called from SMTP EXPN command |
| 775 | |
| 776 | These ones are used by do_callout() -- the options variable |
| 777 | is passed to it. |
| 778 | |
| 779 | vopt_callout_no_cache => don't use callout cache |
| 780 | vopt_callout_random => do the "random" thing |
| 781 | vopt_callout_recipsender => use real sender for recipient |
| 782 | vopt_callout_recippmaster => use postmaster for recipient |
| 783 | |
| 784 | callout if > 0, specifies that callout is required, and gives timeout |
| 785 | for individual connections and commands |
| 786 | callout_overall if > 0, gives overall timeout for the callout function; |
| 787 | if < 0, a default is used (see do_callout()) |
| 788 | se_mailfrom when callout is requested to verify a sender, use this |
| 789 | in MAIL FROM; NULL => "" |
| 790 | pm_mailfrom when callout is requested, if non-NULL, do the postmaster |
| 791 | thing and use this as the sender address (may be "") |
| 792 | |
| 793 | routed if not NULL, set TRUE if routing succeeded, so we can |
| 794 | distinguish between routing failed and callout failed |
| 795 | |
| 796 | Returns: OK address verified |
| 797 | FAIL address failed to verify |
| 798 | DEFER can't tell at present |
| 799 | */ |
| 800 | |
| 801 | int |
| 802 | verify_address(address_item *vaddr, FILE *f, int options, int callout, |
| 803 | int callout_overall, uschar *se_mailfrom, uschar *pm_mailfrom, BOOL *routed) |
| 804 | { |
| 805 | BOOL allok = TRUE; |
| 806 | BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0); |
| 807 | BOOL is_recipient = (options & vopt_is_recipient) != 0; |
| 808 | BOOL expn = (options & vopt_expn) != 0; |
| 809 | |
| 810 | int i; |
| 811 | int yield = OK; |
| 812 | int verify_type = expn? v_expn : |
| 813 | address_test_mode? v_none : |
| 814 | is_recipient? v_recipient : v_sender; |
| 815 | address_item *addr_list; |
| 816 | address_item *addr_new = NULL; |
| 817 | address_item *addr_remote = NULL; |
| 818 | address_item *addr_local = NULL; |
| 819 | address_item *addr_succeed = NULL; |
| 820 | uschar *ko_prefix, *cr; |
| 821 | uschar *address = vaddr->address; |
| 822 | uschar *save_sender; |
| 823 | uschar null_sender[] = { 0 }; /* Ensure writeable memory */ |
| 824 | |
| 825 | /* Set up a prefix and suffix for error message which allow us to use the same |
| 826 | output statements both in EXPN mode (where an SMTP response is needed) and when |
| 827 | debugging with an output file. */ |
| 828 | |
| 829 | if (expn) |
| 830 | { |
| 831 | ko_prefix = US"553 "; |
| 832 | cr = US"\r"; |
| 833 | } |
| 834 | else ko_prefix = cr = US""; |
| 835 | |
| 836 | /* Add qualify domain if permitted; otherwise an unqualified address fails. */ |
| 837 | |
| 838 | if (parse_find_at(address) == NULL) |
| 839 | { |
| 840 | if ((options & vopt_qualify) == 0) |
| 841 | { |
| 842 | if (f != NULL) |
| 843 | fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address, |
| 844 | cr); |
| 845 | return FAIL; |
| 846 | } |
| 847 | address = rewrite_address_qualify(address, is_recipient); |
| 848 | } |
| 849 | |
| 850 | DEBUG(D_verify) |
| 851 | { |
| 852 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 853 | debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address); |
| 854 | } |
| 855 | |
| 856 | /* Rewrite and report on it. Clear the domain and local part caches - these |
| 857 | may have been set by domains and local part tests during an ACL. */ |
| 858 | |
| 859 | if (global_rewrite_rules != NULL) |
| 860 | { |
| 861 | uschar *old = address; |
| 862 | address = rewrite_address(address, is_recipient, FALSE, |
| 863 | global_rewrite_rules, rewrite_existflags); |
| 864 | if (address != old) |
| 865 | { |
| 866 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0; |
| 867 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0; |
| 868 | if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address); |
| 869 | } |
| 870 | } |
| 871 | |
| 872 | /* If this is the real sender address, we must update sender_address at |
| 873 | this point, because it may be referred to in the routers. */ |
| 874 | |
| 875 | if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0) |
| 876 | sender_address = address; |
| 877 | |
| 878 | /* If the address was rewritten to <> no verification can be done, and we have |
| 879 | to return OK. This rewriting is permitted only for sender addresses; for other |
| 880 | addresses, such rewriting fails. */ |
| 881 | |
| 882 | if (address[0] == 0) return OK; |
| 883 | |
| 884 | /* Save a copy of the sender address for re-instating if we change it to <> |
| 885 | while verifying a sender address (a nice bit of self-reference there). */ |
| 886 | |
| 887 | save_sender = sender_address; |
| 888 | |
| 889 | /* Update the address structure with the possibly qualified and rewritten |
| 890 | address. Set it up as the starting address on the chain of new addresses. */ |
| 891 | |
| 892 | vaddr->address = address; |
| 893 | addr_new = vaddr; |
| 894 | |
| 895 | /* We need a loop, because an address can generate new addresses. We must also |
| 896 | cope with generated pipes and files at the top level. (See also the code and |
| 897 | comment in deliver.c.) However, it is usually the case that the router for |
| 898 | user's .forward files has its verify flag turned off. |
| 899 | |
| 900 | If an address generates more than one child, the loop is used only when |
| 901 | full_info is set, and this can only be set locally. Remote enquiries just get |
| 902 | information about the top level address, not anything that it generated. */ |
| 903 | |
| 904 | while (addr_new != NULL) |
| 905 | { |
| 906 | int rc; |
| 907 | address_item *addr = addr_new; |
| 908 | |
| 909 | addr_new = addr->next; |
| 910 | addr->next = NULL; |
| 911 | |
| 912 | DEBUG(D_verify) |
| 913 | { |
| 914 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 915 | debug_printf("Considering %s\n", addr->address); |
| 916 | } |
| 917 | |
| 918 | /* Handle generated pipe, file or reply addresses. We don't get these |
| 919 | when handling EXPN, as it does only one level of expansion. */ |
| 920 | |
| 921 | if (testflag(addr, af_pfr)) |
| 922 | { |
| 923 | allok = FALSE; |
| 924 | if (f != NULL) |
| 925 | { |
| 926 | BOOL allow; |
| 927 | |
| 928 | if (addr->address[0] == '>') |
| 929 | { |
| 930 | allow = testflag(addr, af_allow_reply); |
| 931 | fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1); |
| 932 | } |
| 933 | else |
| 934 | { |
| 935 | allow = (addr->address[0] == '|')? |
| 936 | testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file); |
| 937 | fprintf(f, "%s -> %s", addr->parent->address, addr->address); |
| 938 | } |
| 939 | |
| 940 | if (addr->basic_errno == ERRNO_BADTRANSPORT) |
| 941 | fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n" |
| 942 | "%s\n", addr->message); |
| 943 | else if (allow) |
| 944 | fprintf(f, "\n transport = %s\n", addr->transport->name); |
| 945 | else |
| 946 | fprintf(f, " *** forbidden ***\n"); |
| 947 | } |
| 948 | continue; |
| 949 | } |
| 950 | |
| 951 | /* Just in case some router parameter refers to it. */ |
| 952 | |
| 953 | return_path = (addr->p.errors_address != NULL)? |
| 954 | addr->p.errors_address : sender_address; |
| 955 | |
| 956 | /* Split the address into domain and local part, handling the %-hack if |
| 957 | necessary, and then route it. While routing a sender address, set |
| 958 | $sender_address to <> because that is what it will be if we were trying to |
| 959 | send a bounce to the sender. */ |
| 960 | |
| 961 | if (routed != NULL) *routed = FALSE; |
| 962 | if ((rc = deliver_split_address(addr)) == OK) |
| 963 | { |
| 964 | if (!is_recipient) sender_address = null_sender; |
| 965 | rc = route_address(addr, &addr_local, &addr_remote, &addr_new, |
| 966 | &addr_succeed, verify_type); |
| 967 | sender_address = save_sender; /* Put back the real sender */ |
| 968 | } |
| 969 | |
| 970 | /* If routing an address succeeded, set the flag that remembers, for use when |
| 971 | an ACL cached a sender verify (in case a callout fails). Then if routing set |
| 972 | up a list of hosts or the transport has a host list, and the callout option |
| 973 | is set, and we aren't in a host checking run, do the callout verification, |
| 974 | and set another flag that notes that a callout happened. */ |
| 975 | |
| 976 | if (rc == OK) |
| 977 | { |
| 978 | if (routed != NULL) *routed = TRUE; |
| 979 | if (callout > 0) |
| 980 | { |
| 981 | host_item *host_list = addr->host_list; |
| 982 | |
| 983 | /* Default, if no remote transport, to NULL for the interface (=> any), |
| 984 | "smtp" for the port, and "smtp" for the protocol. */ |
| 985 | |
| 986 | transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE }; |
| 987 | |
| 988 | /* If verification yielded a remote transport, we want to use that |
| 989 | transport's options, so as to mimic what would happen if we were really |
| 990 | sending a message to this address. */ |
| 991 | |
| 992 | if (addr->transport != NULL && !addr->transport->info->local) |
| 993 | { |
| 994 | (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL); |
| 995 | |
| 996 | /* If the transport has hosts and the router does not, or if the |
| 997 | transport is configured to override the router's hosts, we must build a |
| 998 | host list of the transport's hosts, and find the IP addresses */ |
| 999 | |
| 1000 | if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override)) |
| 1001 | { |
| 1002 | uschar *s; |
| 1003 | |
| 1004 | host_list = NULL; /* Ignore the router's hosts */ |
| 1005 | |
| 1006 | deliver_domain = addr->domain; |
| 1007 | deliver_localpart = addr->local_part; |
| 1008 | s = expand_string(tf.hosts); |
| 1009 | deliver_domain = deliver_localpart = NULL; |
| 1010 | |
| 1011 | if (s == NULL) |
| 1012 | { |
| 1013 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts " |
| 1014 | "\"%s\" in %s transport for callout: %s", tf.hosts, |
| 1015 | addr->transport->name, expand_string_message); |
| 1016 | } |
| 1017 | else |
| 1018 | { |
| 1019 | uschar *canonical_name; |
| 1020 | host_item *host; |
| 1021 | host_build_hostlist(&host_list, s, tf.hosts_randomize); |
| 1022 | |
| 1023 | /* Just ignore failures to find a host address. If we don't manage |
| 1024 | to find any addresses, the callout will defer. */ |
| 1025 | |
| 1026 | for (host = host_list; host != NULL; host = host->next) |
| 1027 | { |
| 1028 | if (tf.gethostbyname || string_is_ip_address(host->name, NULL)) |
| 1029 | (void)host_find_byname(host, NULL, &canonical_name, TRUE); |
| 1030 | else |
| 1031 | { |
| 1032 | int flags = HOST_FIND_BY_A; |
| 1033 | if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; |
| 1034 | if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS; |
| 1035 | (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL, |
| 1036 | &canonical_name, NULL); |
| 1037 | } |
| 1038 | } |
| 1039 | } |
| 1040 | } |
| 1041 | } |
| 1042 | |
| 1043 | /* Can only do a callout if we have at least one host! */ |
| 1044 | |
| 1045 | if (host_list != NULL) |
| 1046 | { |
| 1047 | HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n"); |
| 1048 | if (host_checking && !host_checking_callout) |
| 1049 | { |
| 1050 | HDEBUG(D_verify) |
| 1051 | debug_printf("... callout omitted by default when host testing\n" |
| 1052 | "(Use -bhc if you want the callouts to happen.)\n"); |
| 1053 | } |
| 1054 | else |
| 1055 | { |
| 1056 | rc = do_callout(addr, host_list, &tf, callout, callout_overall, |
| 1057 | options, se_mailfrom, pm_mailfrom); |
| 1058 | } |
| 1059 | } |
| 1060 | else |
| 1061 | { |
| 1062 | HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor " |
| 1063 | "transport provided a host list\n"); |
| 1064 | } |
| 1065 | } |
| 1066 | } |
| 1067 | |
| 1068 | /* A router may return REROUTED if it has set up a child address as a result |
| 1069 | of a change of domain name (typically from widening). In this case we always |
| 1070 | want to continue to verify the new child. */ |
| 1071 | |
| 1072 | if (rc == REROUTED) continue; |
| 1073 | |
| 1074 | /* Handle hard failures */ |
| 1075 | |
| 1076 | if (rc == FAIL) |
| 1077 | { |
| 1078 | allok = FALSE; |
| 1079 | if (f != NULL) |
| 1080 | { |
| 1081 | fprintf(f, "%s%s %s", ko_prefix, address, |
| 1082 | address_test_mode? "is undeliverable" : "failed to verify"); |
| 1083 | if (!expn && admin_user) |
| 1084 | { |
| 1085 | if (addr->basic_errno > 0) |
| 1086 | fprintf(f, ": %s", strerror(addr->basic_errno)); |
| 1087 | if (addr->message != NULL) |
| 1088 | fprintf(f, ":\n %s", addr->message); |
| 1089 | } |
| 1090 | fprintf(f, "%s\n", cr); |
| 1091 | } |
| 1092 | |
| 1093 | if (!full_info) return copy_error(vaddr, addr, FAIL); |
| 1094 | else yield = FAIL; |
| 1095 | } |
| 1096 | |
| 1097 | /* Soft failure */ |
| 1098 | |
| 1099 | else if (rc == DEFER) |
| 1100 | { |
| 1101 | allok = FALSE; |
| 1102 | if (f != NULL) |
| 1103 | { |
| 1104 | fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address); |
| 1105 | if (!expn && admin_user) |
| 1106 | { |
| 1107 | if (addr->basic_errno > 0) |
| 1108 | fprintf(f, ":\n %s", strerror(addr->basic_errno)); |
| 1109 | if (addr->message != NULL) |
| 1110 | fprintf(f, ":\n %s", addr->message); |
| 1111 | else if (addr->basic_errno <= 0) |
| 1112 | fprintf(f, ":\n unknown error"); |
| 1113 | } |
| 1114 | |
| 1115 | fprintf(f, "%s\n", cr); |
| 1116 | } |
| 1117 | if (!full_info) return copy_error(vaddr, addr, DEFER); |
| 1118 | else if (yield == OK) yield = DEFER; |
| 1119 | } |
| 1120 | |
| 1121 | /* If we are handling EXPN, we do not want to continue to route beyond |
| 1122 | the top level. */ |
| 1123 | |
| 1124 | else if (expn) |
| 1125 | { |
| 1126 | uschar *ok_prefix = US"250-"; |
| 1127 | if (addr_new == NULL) |
| 1128 | { |
| 1129 | if (addr_local == NULL && addr_remote == NULL) |
| 1130 | fprintf(f, "250 mail to <%s> is discarded\r\n", address); |
| 1131 | else |
| 1132 | fprintf(f, "250 <%s>\r\n", address); |
| 1133 | } |
| 1134 | else while (addr_new != NULL) |
| 1135 | { |
| 1136 | address_item *addr2 = addr_new; |
| 1137 | addr_new = addr2->next; |
| 1138 | if (addr_new == NULL) ok_prefix = US"250 "; |
| 1139 | fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address); |
| 1140 | } |
| 1141 | return OK; |
| 1142 | } |
| 1143 | |
| 1144 | /* Successful routing other than EXPN. */ |
| 1145 | |
| 1146 | else |
| 1147 | { |
| 1148 | /* Handle successful routing when short info wanted. Otherwise continue for |
| 1149 | other (generated) addresses. Short info is the operational case. Full info |
| 1150 | can be requested only when debug_selector != 0 and a file is supplied. |
| 1151 | |
| 1152 | There is a conflict between the use of aliasing as an alternate email |
| 1153 | address, and as a sort of mailing list. If an alias turns the incoming |
| 1154 | address into just one address (e.g. J.Caesar->jc44) you may well want to |
| 1155 | carry on verifying the generated address to ensure it is valid when |
| 1156 | checking incoming mail. If aliasing generates multiple addresses, you |
| 1157 | probably don't want to do this. Exim therefore treats the generation of |
| 1158 | just a single new address as a special case, and continues on to verify the |
| 1159 | generated address. */ |
| 1160 | |
| 1161 | if (!full_info && /* Stop if short info wanted AND */ |
| 1162 | (addr_new == NULL || /* No new address OR */ |
| 1163 | addr_new->next != NULL || /* More than one new address OR */ |
| 1164 | testflag(addr_new, af_pfr))) /* New address is pfr */ |
| 1165 | { |
| 1166 | if (f != NULL) fprintf(f, "%s %s\n", address, |
| 1167 | address_test_mode? "is deliverable" : "verified"); |
| 1168 | |
| 1169 | /* If we have carried on to verify a child address, we want the value |
| 1170 | of $address_data to be that of the child */ |
| 1171 | |
| 1172 | vaddr->p.address_data = addr->p.address_data; |
| 1173 | return OK; |
| 1174 | } |
| 1175 | } |
| 1176 | } /* Loop for generated addresses */ |
| 1177 | |
| 1178 | /* Display the full results of the successful routing, including any generated |
| 1179 | addresses. Control gets here only when full_info is set, which requires f not |
| 1180 | to be NULL, and this occurs only when a top-level verify is called with the |
| 1181 | debugging switch on. |
| 1182 | |
| 1183 | If there are no local and no remote addresses, and there were no pipes, files, |
| 1184 | or autoreplies, and there were no errors or deferments, the message is to be |
| 1185 | discarded, usually because of the use of :blackhole: in an alias file. */ |
| 1186 | |
| 1187 | if (allok && addr_local == NULL && addr_remote == NULL) |
| 1188 | fprintf(f, "mail to %s is discarded\n", address); |
| 1189 | |
| 1190 | else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++) |
| 1191 | { |
| 1192 | while (addr_list != NULL) |
| 1193 | { |
| 1194 | address_item *addr = addr_list; |
| 1195 | address_item *p = addr->parent; |
| 1196 | addr_list = addr->next; |
| 1197 | |
| 1198 | fprintf(f, "%s", CS addr->address); |
| 1199 | while (p != NULL) |
| 1200 | { |
| 1201 | fprintf(f, "\n <-- %s", p->address); |
| 1202 | p = p->parent; |
| 1203 | } |
| 1204 | fprintf(f, "\n "); |
| 1205 | |
| 1206 | /* Show router, and transport */ |
| 1207 | |
| 1208 | fprintf(f, "router = %s, ", addr->router->name); |
| 1209 | fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" : |
| 1210 | addr->transport->name); |
| 1211 | |
| 1212 | /* Show any hosts that are set up by a router unless the transport |
| 1213 | is going to override them; fiddle a bit to get a nice format. */ |
| 1214 | |
| 1215 | if (addr->host_list != NULL && addr->transport != NULL && |
| 1216 | !addr->transport->overrides_hosts) |
| 1217 | { |
| 1218 | host_item *h; |
| 1219 | int maxlen = 0; |
| 1220 | int maxaddlen = 0; |
| 1221 | for (h = addr->host_list; h != NULL; h = h->next) |
| 1222 | { |
| 1223 | int len = Ustrlen(h->name); |
| 1224 | if (len > maxlen) maxlen = len; |
| 1225 | len = (h->address != NULL)? Ustrlen(h->address) : 7; |
| 1226 | if (len > maxaddlen) maxaddlen = len; |
| 1227 | } |
| 1228 | for (h = addr->host_list; h != NULL; h = h->next) |
| 1229 | { |
| 1230 | int len = Ustrlen(h->name); |
| 1231 | fprintf(f, " host %s ", h->name); |
| 1232 | while (len++ < maxlen) fprintf(f, " "); |
| 1233 | if (h->address != NULL) |
| 1234 | { |
| 1235 | fprintf(f, "[%s] ", h->address); |
| 1236 | len = Ustrlen(h->address); |
| 1237 | } |
| 1238 | else if (!addr->transport->info->local) /* Omit [unknown] for local */ |
| 1239 | { |
| 1240 | fprintf(f, "[unknown] "); |
| 1241 | len = 7; |
| 1242 | } |
| 1243 | else len = -3; |
| 1244 | while (len++ < maxaddlen) fprintf(f," "); |
| 1245 | if (h->mx >= 0) fprintf(f, "MX=%d", h->mx); |
| 1246 | if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port); |
| 1247 | if (h->status == hstatus_unusable) fprintf(f, " ** unusable **"); |
| 1248 | fprintf(f, "\n"); |
| 1249 | } |
| 1250 | } |
| 1251 | } |
| 1252 | } |
| 1253 | |
| 1254 | return yield; /* Will be DEFER or FAIL if any one address has */ |
| 1255 | } |
| 1256 | |
| 1257 | |
| 1258 | |
| 1259 | |
| 1260 | /************************************************* |
| 1261 | * Check headers for syntax errors * |
| 1262 | *************************************************/ |
| 1263 | |
| 1264 | /* This function checks those header lines that contain addresses, and verifies |
| 1265 | that all the addresses therein are syntactially correct. |
| 1266 | |
| 1267 | Arguments: |
| 1268 | msgptr where to put an error message |
| 1269 | |
| 1270 | Returns: OK |
| 1271 | FAIL |
| 1272 | */ |
| 1273 | |
| 1274 | int |
| 1275 | verify_check_headers(uschar **msgptr) |
| 1276 | { |
| 1277 | header_line *h; |
| 1278 | uschar *colon, *s; |
| 1279 | |
| 1280 | for (h = header_list; h != NULL; h = h->next) |
| 1281 | { |
| 1282 | if (h->type != htype_from && |
| 1283 | h->type != htype_reply_to && |
| 1284 | h->type != htype_sender && |
| 1285 | h->type != htype_to && |
| 1286 | h->type != htype_cc && |
| 1287 | h->type != htype_bcc) |
| 1288 | continue; |
| 1289 | |
| 1290 | colon = Ustrchr(h->text, ':'); |
| 1291 | s = colon + 1; |
| 1292 | while (isspace(*s)) s++; |
| 1293 | |
| 1294 | parse_allow_group = TRUE; /* Allow group syntax */ |
| 1295 | |
| 1296 | /* Loop for multiple addresses in the header */ |
| 1297 | |
| 1298 | while (*s != 0) |
| 1299 | { |
| 1300 | uschar *ss = parse_find_address_end(s, FALSE); |
| 1301 | uschar *recipient, *errmess; |
| 1302 | int terminator = *ss; |
| 1303 | int start, end, domain; |
| 1304 | |
| 1305 | /* Temporarily terminate the string at this point, and extract the |
| 1306 | operative address within. */ |
| 1307 | |
| 1308 | *ss = 0; |
| 1309 | recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); |
| 1310 | *ss = terminator; |
| 1311 | |
| 1312 | /* Permit an unqualified address only if the message is local, or if the |
| 1313 | sending host is configured to be permitted to send them. */ |
| 1314 | |
| 1315 | if (recipient != NULL && domain == 0) |
| 1316 | { |
| 1317 | if (h->type == htype_from || h->type == htype_sender) |
| 1318 | { |
| 1319 | if (!allow_unqualified_sender) recipient = NULL; |
| 1320 | } |
| 1321 | else |
| 1322 | { |
| 1323 | if (!allow_unqualified_recipient) recipient = NULL; |
| 1324 | } |
| 1325 | if (recipient == NULL) errmess = US"unqualified address not permitted"; |
| 1326 | } |
| 1327 | |
| 1328 | /* It's an error if no address could be extracted, except for the special |
| 1329 | case of an empty address. */ |
| 1330 | |
| 1331 | if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0) |
| 1332 | { |
| 1333 | uschar *verb = US"is"; |
| 1334 | uschar *t = ss; |
| 1335 | int len; |
| 1336 | |
| 1337 | /* Arrange not to include any white space at the end in the |
| 1338 | error message. */ |
| 1339 | |
| 1340 | while (t > s && isspace(t[-1])) t--; |
| 1341 | |
| 1342 | /* Add the address which failed to the error message, since in a |
| 1343 | header with very many addresses it is sometimes hard to spot |
| 1344 | which one is at fault. However, limit the amount of address to |
| 1345 | quote - cases have been seen where, for example, a missing double |
| 1346 | quote in a humungous To: header creates an "address" that is longer |
| 1347 | than string_sprintf can handle. */ |
| 1348 | |
| 1349 | len = t - s; |
| 1350 | if (len > 1024) |
| 1351 | { |
| 1352 | len = 1024; |
| 1353 | verb = US"begins"; |
| 1354 | } |
| 1355 | |
| 1356 | *msgptr = string_printing( |
| 1357 | string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s", |
| 1358 | errmess, colon - h->text, h->text, verb, len, s)); |
| 1359 | |
| 1360 | return FAIL; |
| 1361 | } |
| 1362 | |
| 1363 | /* Advance to the next address */ |
| 1364 | |
| 1365 | s = ss + (terminator? 1:0); |
| 1366 | while (isspace(*s)) s++; |
| 1367 | } /* Next address */ |
| 1368 | } /* Next header */ |
| 1369 | |
| 1370 | return OK; |
| 1371 | } |
| 1372 | |
| 1373 | |
| 1374 | |
| 1375 | |
| 1376 | /************************************************* |
| 1377 | * Find if verified sender * |
| 1378 | *************************************************/ |
| 1379 | |
| 1380 | /* Usually, just a single address is verified as the sender of the message. |
| 1381 | However, Exim can be made to verify other addresses as well (often related in |
| 1382 | some way), and this is useful in some environments. There may therefore be a |
| 1383 | chain of such addresses that have previously been tested. This function finds |
| 1384 | whether a given address is on the chain. |
| 1385 | |
| 1386 | Arguments: the address to be verified |
| 1387 | Returns: pointer to an address item, or NULL |
| 1388 | */ |
| 1389 | |
| 1390 | address_item * |
| 1391 | verify_checked_sender(uschar *sender) |
| 1392 | { |
| 1393 | address_item *addr; |
| 1394 | for (addr = sender_verified_list; addr != NULL; addr = addr->next) |
| 1395 | if (Ustrcmp(sender, addr->address) == 0) break; |
| 1396 | return addr; |
| 1397 | } |
| 1398 | |
| 1399 | |
| 1400 | |
| 1401 | |
| 1402 | |
| 1403 | /************************************************* |
| 1404 | * Get valid header address * |
| 1405 | *************************************************/ |
| 1406 | |
| 1407 | /* Scan the originator headers of the message, looking for an address that |
| 1408 | verifies successfully. RFC 822 says: |
| 1409 | |
| 1410 | o The "Sender" field mailbox should be sent notices of |
| 1411 | any problems in transport or delivery of the original |
| 1412 | messages. If there is no "Sender" field, then the |
| 1413 | "From" field mailbox should be used. |
| 1414 | |
| 1415 | o If the "Reply-To" field exists, then the reply should |
| 1416 | go to the addresses indicated in that field and not to |
| 1417 | the address(es) indicated in the "From" field. |
| 1418 | |
| 1419 | So we check a Sender field if there is one, else a Reply_to field, else a From |
| 1420 | field. As some strange messages may have more than one of these fields, |
| 1421 | especially if they are resent- fields, check all of them if there is more than |
| 1422 | one. |
| 1423 | |
| 1424 | Arguments: |
| 1425 | user_msgptr points to where to put a user error message |
| 1426 | log_msgptr points to where to put a log error message |
| 1427 | callout timeout for callout check (passed to verify_address()) |
| 1428 | callout_overall overall callout timeout (ditto) |
| 1429 | se_mailfrom mailfrom for verify; NULL => "" |
| 1430 | pm_mailfrom sender for pm callout check (passed to verify_address()) |
| 1431 | options callout options (passed to verify_address()) |
| 1432 | |
| 1433 | If log_msgptr is set to something without setting user_msgptr, the caller |
| 1434 | normally uses log_msgptr for both things. |
| 1435 | |
| 1436 | Returns: result of the verification attempt: OK, FAIL, or DEFER; |
| 1437 | FAIL is given if no appropriate headers are found |
| 1438 | */ |
| 1439 | |
| 1440 | int |
| 1441 | verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr, |
| 1442 | int callout, int callout_overall, uschar *se_mailfrom, uschar *pm_mailfrom, |
| 1443 | int options) |
| 1444 | { |
| 1445 | static int header_types[] = { htype_sender, htype_reply_to, htype_from }; |
| 1446 | int yield = FAIL; |
| 1447 | int i; |
| 1448 | |
| 1449 | for (i = 0; i < 3; i++) |
| 1450 | { |
| 1451 | header_line *h; |
| 1452 | for (h = header_list; h != NULL; h = h->next) |
| 1453 | { |
| 1454 | int terminator, new_ok; |
| 1455 | uschar *s, *ss, *endname; |
| 1456 | |
| 1457 | if (h->type != header_types[i]) continue; |
| 1458 | s = endname = Ustrchr(h->text, ':') + 1; |
| 1459 | |
| 1460 | while (*s != 0) |
| 1461 | { |
| 1462 | address_item *vaddr; |
| 1463 | |
| 1464 | while (isspace(*s) || *s == ',') s++; |
| 1465 | if (*s == 0) break; /* End of header */ |
| 1466 | |
| 1467 | ss = parse_find_address_end(s, FALSE); |
| 1468 | |
| 1469 | /* The terminator is a comma or end of header, but there may be white |
| 1470 | space preceding it (including newline for the last address). Move back |
| 1471 | past any white space so we can check against any cached envelope sender |
| 1472 | address verifications. */ |
| 1473 | |
| 1474 | while (isspace(ss[-1])) ss--; |
| 1475 | terminator = *ss; |
| 1476 | *ss = 0; |
| 1477 | |
| 1478 | HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n", |
| 1479 | (int)(endname - h->text), h->text, s); |
| 1480 | |
| 1481 | /* See if we have already verified this address as an envelope sender, |
| 1482 | and if so, use the previous answer. */ |
| 1483 | |
| 1484 | vaddr = verify_checked_sender(s); |
| 1485 | |
| 1486 | if (vaddr != NULL && /* Previously checked */ |
| 1487 | (callout <= 0 || /* No callout needed; OR */ |
| 1488 | vaddr->special_action > 256)) /* Callout was done */ |
| 1489 | { |
| 1490 | new_ok = vaddr->special_action & 255; |
| 1491 | HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n"); |
| 1492 | *ss = terminator; /* Restore shortened string */ |
| 1493 | } |
| 1494 | |
| 1495 | /* Otherwise we run the verification now. We must restore the shortened |
| 1496 | string before running the verification, so the headers are correct, in |
| 1497 | case there is any rewriting. */ |
| 1498 | |
| 1499 | else |
| 1500 | { |
| 1501 | int start, end, domain; |
| 1502 | uschar *address = parse_extract_address(s, log_msgptr, &start, |
| 1503 | &end, &domain, FALSE); |
| 1504 | |
| 1505 | *ss = terminator; |
| 1506 | |
| 1507 | /* If verification failed because of a syntax error, fail this |
| 1508 | function, and ensure that the failing address gets added to the error |
| 1509 | message. */ |
| 1510 | |
| 1511 | if (address == NULL) |
| 1512 | { |
| 1513 | new_ok = FAIL; |
| 1514 | if (*log_msgptr != NULL) |
| 1515 | { |
| 1516 | while (ss > s && isspace(ss[-1])) ss--; |
| 1517 | *log_msgptr = string_sprintf("syntax error in '%.*s' header when " |
| 1518 | "scanning for sender: %s in \"%.*s\"", |
| 1519 | endname - h->text, h->text, *log_msgptr, ss - s, s); |
| 1520 | return FAIL; |
| 1521 | } |
| 1522 | } |
| 1523 | |
| 1524 | /* Else go ahead with the sender verification. But is isn't *the* |
| 1525 | sender of the message, so set vopt_fake_sender to stop sender_address |
| 1526 | being replaced after rewriting or qualification. */ |
| 1527 | |
| 1528 | else |
| 1529 | { |
| 1530 | vaddr = deliver_make_addr(address, FALSE); |
| 1531 | new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender, |
| 1532 | callout, callout_overall, se_mailfrom, pm_mailfrom, NULL); |
| 1533 | } |
| 1534 | } |
| 1535 | |
| 1536 | /* We now have the result, either newly found, or cached. If we are |
| 1537 | giving out error details, set a specific user error. This means that the |
| 1538 | last of these will be returned to the user if all three fail. We do not |
| 1539 | set a log message - the generic one below will be used. */ |
| 1540 | |
| 1541 | if (new_ok != OK && smtp_return_error_details) |
| 1542 | { |
| 1543 | *user_msgptr = string_sprintf("Rejected after DATA: " |
| 1544 | "could not verify \"%.*s\" header address\n%s: %s", |
| 1545 | endname - h->text, h->text, vaddr->address, vaddr->message); |
| 1546 | } |
| 1547 | |
| 1548 | /* Success or defer */ |
| 1549 | |
| 1550 | if (new_ok == OK) return OK; |
| 1551 | if (new_ok == DEFER) yield = DEFER; |
| 1552 | |
| 1553 | /* Move on to any more addresses in the header */ |
| 1554 | |
| 1555 | s = ss; |
| 1556 | } |
| 1557 | } |
| 1558 | } |
| 1559 | |
| 1560 | if (yield == FAIL && *log_msgptr == NULL) |
| 1561 | *log_msgptr = US"there is no valid sender in any header line"; |
| 1562 | |
| 1563 | if (yield == DEFER && *log_msgptr == NULL) |
| 1564 | *log_msgptr = US"all attempts to verify a sender in a header line deferred"; |
| 1565 | |
| 1566 | return yield; |
| 1567 | } |
| 1568 | |
| 1569 | |
| 1570 | |
| 1571 | |
| 1572 | /************************************************* |
| 1573 | * Get RFC 1413 identification * |
| 1574 | *************************************************/ |
| 1575 | |
| 1576 | /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If |
| 1577 | the timeout is set to zero, then the query is not done. There may also be lists |
| 1578 | of hosts and nets which are exempt. To guard against malefactors sending |
| 1579 | non-printing characters which could, for example, disrupt a message's headers, |
| 1580 | make sure the string consists of printing characters only. |
| 1581 | |
| 1582 | Argument: |
| 1583 | port the port to connect to; usually this is IDENT_PORT (113), but when |
| 1584 | running in the test harness with -bh a different value is used. |
| 1585 | |
| 1586 | Returns: nothing |
| 1587 | |
| 1588 | Side effect: any received ident value is put in sender_ident (NULL otherwise) |
| 1589 | */ |
| 1590 | |
| 1591 | void |
| 1592 | verify_get_ident(int port) |
| 1593 | { |
| 1594 | int sock, host_af, qlen; |
| 1595 | int received_sender_port, received_interface_port, n; |
| 1596 | uschar *p; |
| 1597 | uschar buffer[2048]; |
| 1598 | |
| 1599 | /* Default is no ident. Check whether we want to do an ident check for this |
| 1600 | host. */ |
| 1601 | |
| 1602 | sender_ident = NULL; |
| 1603 | if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK) |
| 1604 | return; |
| 1605 | |
| 1606 | DEBUG(D_ident) debug_printf("doing ident callback\n"); |
| 1607 | |
| 1608 | /* Set up a connection to the ident port of the remote host. Bind the local end |
| 1609 | to the incoming interface address. If the sender host address is an IPv6 |
| 1610 | address, the incoming interface address will also be IPv6. */ |
| 1611 | |
| 1612 | host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6; |
| 1613 | sock = ip_socket(SOCK_STREAM, host_af); |
| 1614 | if (sock < 0) return; |
| 1615 | |
| 1616 | if (ip_bind(sock, host_af, interface_address, 0) < 0) |
| 1617 | { |
| 1618 | DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n", |
| 1619 | strerror(errno)); |
| 1620 | goto END_OFF; |
| 1621 | } |
| 1622 | |
| 1623 | if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout) |
| 1624 | < 0) |
| 1625 | { |
| 1626 | if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0) |
| 1627 | { |
| 1628 | log_write(0, LOG_MAIN, "ident connection to %s timed out", |
| 1629 | sender_host_address); |
| 1630 | } |
| 1631 | else |
| 1632 | { |
| 1633 | DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n", |
| 1634 | sender_host_address, strerror(errno)); |
| 1635 | } |
| 1636 | goto END_OFF; |
| 1637 | } |
| 1638 | |
| 1639 | /* Construct and send the query. */ |
| 1640 | |
| 1641 | sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port); |
| 1642 | qlen = Ustrlen(buffer); |
| 1643 | if (send(sock, buffer, qlen, 0) < 0) |
| 1644 | { |
| 1645 | DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno)); |
| 1646 | goto END_OFF; |
| 1647 | } |
| 1648 | |
| 1649 | /* Read a response line. We put it into the rest of the buffer, using several |
| 1650 | recv() calls if necessary. */ |
| 1651 | |
| 1652 | p = buffer + qlen; |
| 1653 | |
| 1654 | for (;;) |
| 1655 | { |
| 1656 | uschar *pp; |
| 1657 | int count; |
| 1658 | int size = sizeof(buffer) - (p - buffer); |
| 1659 | |
| 1660 | if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */ |
| 1661 | count = ip_recv(sock, p, size, rfc1413_query_timeout); |
| 1662 | if (count <= 0) goto END_OFF; /* Read error or EOF */ |
| 1663 | |
| 1664 | /* Scan what we just read, to see if we have reached the terminating \r\n. Be |
| 1665 | generous, and accept a plain \n terminator as well. The only illegal |
| 1666 | character is 0. */ |
| 1667 | |
| 1668 | for (pp = p; pp < p + count; pp++) |
| 1669 | { |
| 1670 | if (*pp == 0) goto END_OFF; /* Zero octet not allowed */ |
| 1671 | if (*pp == '\n') |
| 1672 | { |
| 1673 | if (pp[-1] == '\r') pp--; |
| 1674 | *pp = 0; |
| 1675 | goto GOT_DATA; /* Break out of both loops */ |
| 1676 | } |
| 1677 | } |
| 1678 | |
| 1679 | /* Reached the end of the data without finding \n. Let the loop continue to |
| 1680 | read some more, if there is room. */ |
| 1681 | |
| 1682 | p = pp; |
| 1683 | } |
| 1684 | |
| 1685 | GOT_DATA: |
| 1686 | |
| 1687 | /* We have received a line of data. Check it carefully. It must start with the |
| 1688 | same two port numbers that we sent, followed by data as defined by the RFC. For |
| 1689 | example, |
| 1690 | |
| 1691 | 12345 , 25 : USERID : UNIX :root |
| 1692 | |
| 1693 | However, the amount of white space may be different to what we sent. In the |
| 1694 | "osname" field there may be several sub-fields, comma separated. The data we |
| 1695 | actually want to save follows the third colon. Some systems put leading spaces |
| 1696 | in it - we discard those. */ |
| 1697 | |
| 1698 | if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port, |
| 1699 | &received_interface_port, &n) != 2 || |
| 1700 | received_sender_port != sender_host_port || |
| 1701 | received_interface_port != interface_port) |
| 1702 | goto END_OFF; |
| 1703 | |
| 1704 | p = buffer + qlen + n; |
| 1705 | while(isspace(*p)) p++; |
| 1706 | if (*p++ != ':') goto END_OFF; |
| 1707 | while(isspace(*p)) p++; |
| 1708 | if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF; |
| 1709 | p += 6; |
| 1710 | while(isspace(*p)) p++; |
| 1711 | if (*p++ != ':') goto END_OFF; |
| 1712 | while (*p != 0 && *p != ':') p++; |
| 1713 | if (*p++ == 0) goto END_OFF; |
| 1714 | while(isspace(*p)) p++; |
| 1715 | if (*p == 0) goto END_OFF; |
| 1716 | |
| 1717 | /* The rest of the line is the data we want. We turn it into printing |
| 1718 | characters when we save it, so that it cannot mess up the format of any logging |
| 1719 | or Received: lines into which it gets inserted. We keep a maximum of 127 |
| 1720 | characters. */ |
| 1721 | |
| 1722 | sender_ident = string_printing(string_copyn(p, 127)); |
| 1723 | DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident); |
| 1724 | |
| 1725 | END_OFF: |
| 1726 | close(sock); |
| 1727 | return; |
| 1728 | } |
| 1729 | |
| 1730 | |
| 1731 | |
| 1732 | |
| 1733 | /************************************************* |
| 1734 | * Match host to a single host-list item * |
| 1735 | *************************************************/ |
| 1736 | |
| 1737 | /* This function compares a host (name or address) against a single item |
| 1738 | from a host list. The host name gets looked up if it is needed and is not |
| 1739 | already known. The function is called from verify_check_this_host() via |
| 1740 | match_check_list(), which is why most of its arguments are in a single block. |
| 1741 | |
| 1742 | Arguments: |
| 1743 | arg the argument block (see below) |
| 1744 | ss the host-list item |
| 1745 | valueptr where to pass back looked up data, or NULL |
| 1746 | error for error message when returning ERROR |
| 1747 | |
| 1748 | The block contains: |
| 1749 | host_name the host name or NULL, implying use sender_host_name and |
| 1750 | sender_host_aliases, looking them up if required |
| 1751 | host_address the host address |
| 1752 | host_ipv4 the IPv4 address taken from an IPv6 one |
| 1753 | |
| 1754 | Returns: OK matched |
| 1755 | FAIL did not match |
| 1756 | DEFER lookup deferred |
| 1757 | ERROR failed to find the host name or IP address |
| 1758 | unknown lookup type specified |
| 1759 | */ |
| 1760 | |
| 1761 | static int |
| 1762 | check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error) |
| 1763 | { |
| 1764 | check_host_block *cb = (check_host_block *)arg; |
| 1765 | int maskoffset; |
| 1766 | BOOL isquery = FALSE; |
| 1767 | uschar *semicolon, *t; |
| 1768 | uschar **aliases; |
| 1769 | |
| 1770 | /* Optimize for the special case when the pattern is "*". */ |
| 1771 | |
| 1772 | if (*ss == '*' && ss[1] == 0) return OK; |
| 1773 | |
| 1774 | /* If the pattern is empty, it matches only in the case when there is no host - |
| 1775 | this can occur in ACL checking for SMTP input using the -bs option. In this |
| 1776 | situation, the host address is the empty string. */ |
| 1777 | |
| 1778 | if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL; |
| 1779 | if (*ss == 0) return FAIL; |
| 1780 | |
| 1781 | /* If the pattern is precisely "@" then match against the primary host name; |
| 1782 | if it's "@[]" match against the local host's IP addresses. */ |
| 1783 | |
| 1784 | if (*ss == '@') |
| 1785 | { |
| 1786 | if (ss[1] == 0) ss = primary_hostname; |
| 1787 | else if (Ustrcmp(ss, "@[]") == 0) |
| 1788 | { |
| 1789 | ip_address_item *ip; |
| 1790 | for (ip = host_find_interfaces(); ip != NULL; ip = ip->next) |
| 1791 | if (Ustrcmp(ip->address, cb->host_address) == 0) return OK; |
| 1792 | return FAIL; |
| 1793 | } |
| 1794 | } |
| 1795 | |
| 1796 | /* If the pattern is an IP address, optionally followed by a bitmask count, do |
| 1797 | a (possibly masked) comparision with the current IP address. */ |
| 1798 | |
| 1799 | if (string_is_ip_address(ss, &maskoffset)) |
| 1800 | return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL); |
| 1801 | |
| 1802 | /* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on |
| 1803 | a masked IP network, in textual form. The net- stuff really only applies to |
| 1804 | single-key lookups where the key is implicit. For query-style lookups the key |
| 1805 | is specified in the query. From release 4.30, the use of net- for query style |
| 1806 | is no longer needed, but we retain it for backward compatibility. */ |
| 1807 | |
| 1808 | if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL) |
| 1809 | { |
| 1810 | int mlen = 0; |
| 1811 | for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0'; |
| 1812 | if (*t++ == '-') |
| 1813 | { |
| 1814 | int insize; |
| 1815 | int search_type; |
| 1816 | int incoming[4]; |
| 1817 | void *handle; |
| 1818 | uschar *filename, *key, *result; |
| 1819 | uschar buffer[64]; |
| 1820 | |
| 1821 | /* If no mask was supplied, set a negative value */ |
| 1822 | |
| 1823 | if (mlen == 0 && t == ss+4) mlen = -1; |
| 1824 | |
| 1825 | /* Find the search type */ |
| 1826 | |
| 1827 | search_type = search_findtype(t, semicolon - t); |
| 1828 | |
| 1829 | if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", |
| 1830 | search_error_message); |
| 1831 | |
| 1832 | /* Adjust parameters for the type of lookup. For a query-style |
| 1833 | lookup, there is no file name, and the "key" is just the query. For |
| 1834 | a single-key lookup, the key is the current IP address, masked |
| 1835 | appropriately, and reconverted to text form, with the mask appended. */ |
| 1836 | |
| 1837 | if (mac_islookup(search_type, lookup_querystyle)) |
| 1838 | { |
| 1839 | filename = NULL; |
| 1840 | key = semicolon + 1; |
| 1841 | } |
| 1842 | else |
| 1843 | { |
| 1844 | insize = host_aton(cb->host_address, incoming); |
| 1845 | host_mask(insize, incoming, mlen); |
| 1846 | (void)host_nmtoa(insize, incoming, mlen, buffer); |
| 1847 | key = buffer; |
| 1848 | filename = semicolon + 1; |
| 1849 | } |
| 1850 | |
| 1851 | /* Now do the actual lookup; note that there is no search_close() because |
| 1852 | of the caching arrangements. */ |
| 1853 | |
| 1854 | handle = search_open(filename, search_type, 0, NULL, NULL); |
| 1855 | if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", |
| 1856 | search_error_message); |
| 1857 | result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL); |
| 1858 | if (valueptr != NULL) *valueptr = result; |
| 1859 | return (result != NULL)? OK : search_find_defer? DEFER: FAIL; |
| 1860 | } |
| 1861 | } |
| 1862 | |
| 1863 | /* The pattern is not an IP address or network reference of any kind. That is, |
| 1864 | it is a host name pattern. Check the characters of the pattern to see if they |
| 1865 | comprise only letters, digits, full stops, and hyphens (the constituents of |
| 1866 | domain names). Allow underscores, as they are all too commonly found. Sigh. |
| 1867 | Also, if allow_utf8_domains is set, allow top-bit characters. */ |
| 1868 | |
| 1869 | for (t = ss; *t != 0; t++) |
| 1870 | if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' && |
| 1871 | (!allow_utf8_domains || *t < 128)) break; |
| 1872 | |
| 1873 | /* If the pattern is a complete domain name, with no fancy characters, look up |
| 1874 | its IP address and match against that. Note that a multi-homed host will add |
| 1875 | items to the chain. */ |
| 1876 | |
| 1877 | if (*t == 0) |
| 1878 | { |
| 1879 | int rc; |
| 1880 | host_item h; |
| 1881 | h.next = NULL; |
| 1882 | h.name = ss; |
| 1883 | h.address = NULL; |
| 1884 | h.mx = MX_NONE; |
| 1885 | rc = host_find_byname(&h, NULL, NULL, FALSE); |
| 1886 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) |
| 1887 | { |
| 1888 | host_item *hh; |
| 1889 | for (hh = &h; hh != NULL; hh = hh->next) |
| 1890 | { |
| 1891 | if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)? |
| 1892 | cb->host_ipv4 : cb->host_address) == 0) |
| 1893 | return OK; |
| 1894 | } |
| 1895 | return FAIL; |
| 1896 | } |
| 1897 | if (rc == HOST_FIND_AGAIN) return DEFER; |
| 1898 | *error = string_sprintf("failed to find IP address for %s", ss); |
| 1899 | return ERROR; |
| 1900 | } |
| 1901 | |
| 1902 | /* Almost all subsequent comparisons require the host name, and can be done |
| 1903 | using the general string matching function. When this function is called for |
| 1904 | outgoing hosts, the name is always given explicitly. If it is NULL, it means we |
| 1905 | must use sender_host_name and its aliases, looking them up if necessary. */ |
| 1906 | |
| 1907 | if (cb->host_name != NULL) /* Explicit host name given */ |
| 1908 | return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE, |
| 1909 | valueptr); |
| 1910 | |
| 1911 | /* Host name not given; in principle we need the sender host name and its |
| 1912 | aliases. However, for query-style lookups, we do not need the name if the |
| 1913 | query does not contain $sender_host_name. From release 4.23, a reference to |
| 1914 | $sender_host_name causes it to be looked up, so we don't need to do the lookup |
| 1915 | on spec. */ |
| 1916 | |
| 1917 | if ((semicolon = Ustrchr(ss, ';')) != NULL) |
| 1918 | { |
| 1919 | uschar *affix; |
| 1920 | int partial, affixlen, starflags, id; |
| 1921 | |
| 1922 | *semicolon = 0; |
| 1923 | id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags); |
| 1924 | *semicolon=';'; |
| 1925 | |
| 1926 | if (id < 0) /* Unknown lookup type */ |
| 1927 | { |
| 1928 | log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"", |
| 1929 | search_error_message, ss); |
| 1930 | return DEFER; |
| 1931 | } |
| 1932 | isquery = mac_islookup(id, lookup_querystyle); |
| 1933 | } |
| 1934 | |
| 1935 | if (isquery) |
| 1936 | { |
| 1937 | switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr)) |
| 1938 | { |
| 1939 | case OK: return OK; |
| 1940 | case DEFER: return DEFER; |
| 1941 | default: return FAIL; |
| 1942 | } |
| 1943 | } |
| 1944 | |
| 1945 | /* Not a query-style lookup; must ensure the host name is present, and then we |
| 1946 | do a check on the name and all its aliases. */ |
| 1947 | |
| 1948 | if (sender_host_name == NULL) |
| 1949 | { |
| 1950 | HDEBUG(D_host_lookup) |
| 1951 | debug_printf("sender host name required, to match against %s\n", ss); |
| 1952 | if (host_lookup_failed || host_name_lookup() != OK) |
| 1953 | { |
| 1954 | *error = string_sprintf("failed to find host name for %s", |
| 1955 | sender_host_address);; |
| 1956 | return ERROR; |
| 1957 | } |
| 1958 | host_build_sender_fullhost(); |
| 1959 | } |
| 1960 | |
| 1961 | /* Match on the sender host name, using the general matching function */ |
| 1962 | |
| 1963 | switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, |
| 1964 | valueptr)) |
| 1965 | { |
| 1966 | case OK: return OK; |
| 1967 | case DEFER: return DEFER; |
| 1968 | } |
| 1969 | |
| 1970 | /* If there are aliases, try matching on them. */ |
| 1971 | |
| 1972 | aliases = sender_host_aliases; |
| 1973 | while (*aliases != NULL) |
| 1974 | { |
| 1975 | switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr)) |
| 1976 | { |
| 1977 | case OK: return OK; |
| 1978 | case DEFER: return DEFER; |
| 1979 | } |
| 1980 | } |
| 1981 | return FAIL; |
| 1982 | } |
| 1983 | |
| 1984 | |
| 1985 | |
| 1986 | |
| 1987 | /************************************************* |
| 1988 | * Check a specific host matches a host list * |
| 1989 | *************************************************/ |
| 1990 | |
| 1991 | /* This function is passed a host list containing items in a number of |
| 1992 | different formats and the identity of a host. Its job is to determine whether |
| 1993 | the given host is in the set of hosts defined by the list. The host name is |
| 1994 | passed as a pointer so that it can be looked up if needed and not already |
| 1995 | known. This is commonly the case when called from verify_check_host() to check |
| 1996 | an incoming connection. When called from elsewhere the host name should usually |
| 1997 | be set. |
| 1998 | |
| 1999 | This function is now just a front end to match_check_list(), which runs common |
| 2000 | code for scanning a list. We pass it the check_host() function to perform a |
| 2001 | single test. |
| 2002 | |
| 2003 | Arguments: |
| 2004 | listptr pointer to the host list |
| 2005 | cache_bits pointer to cache for named lists, or NULL |
| 2006 | host_name the host name or NULL, implying use sender_host_name and |
| 2007 | sender_host_aliases, looking them up if required |
| 2008 | host_address the IP address |
| 2009 | valueptr if not NULL, data from a lookup is passed back here |
| 2010 | |
| 2011 | Returns: OK if the host is in the defined set |
| 2012 | FAIL if the host is not in the defined set, |
| 2013 | DEFER if a data lookup deferred (not a host lookup) |
| 2014 | |
| 2015 | If the host name was needed in order to make a comparison, and could not be |
| 2016 | determined from the IP address, the result is FAIL unless the item |
| 2017 | "+allow_unknown" was met earlier in the list, in which case OK is returned. */ |
| 2018 | |
| 2019 | int |
| 2020 | verify_check_this_host(uschar **listptr, unsigned int *cache_bits, |
| 2021 | uschar *host_name, uschar *host_address, uschar **valueptr) |
| 2022 | { |
| 2023 | unsigned int *local_cache_bits = cache_bits; |
| 2024 | check_host_block cb; |
| 2025 | cb.host_name = host_name; |
| 2026 | cb.host_address = host_address; |
| 2027 | |
| 2028 | if (valueptr != NULL) *valueptr = NULL; |
| 2029 | |
| 2030 | /* If the host address starts off ::ffff: it is an IPv6 address in |
| 2031 | IPv4-compatible mode. Find the IPv4 part for checking against IPv4 |
| 2032 | addresses. */ |
| 2033 | |
| 2034 | cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)? |
| 2035 | host_address + 7 : host_address; |
| 2036 | |
| 2037 | return match_check_list(listptr, 0, &hostlist_anchor, &local_cache_bits, |
| 2038 | check_host, &cb, MCL_HOST, |
| 2039 | (host_address == sender_host_address)? US"host" : host_address, valueptr); |
| 2040 | } |
| 2041 | |
| 2042 | |
| 2043 | |
| 2044 | |
| 2045 | /************************************************* |
| 2046 | * Check the remote host matches a list * |
| 2047 | *************************************************/ |
| 2048 | |
| 2049 | /* This is a front end to verify_check_this_host(), created because checking |
| 2050 | the remote host is a common occurrence. With luck, a good compiler will spot |
| 2051 | the tail recursion and optimize it. If there's no host address, this is |
| 2052 | command-line SMTP input - check against an empty string for the address. |
| 2053 | |
| 2054 | Arguments: |
| 2055 | listptr pointer to the host list |
| 2056 | |
| 2057 | Returns: the yield of verify_check_this_host(), |
| 2058 | i.e. OK, FAIL, or DEFER |
| 2059 | */ |
| 2060 | |
| 2061 | int |
| 2062 | verify_check_host(uschar **listptr) |
| 2063 | { |
| 2064 | return verify_check_this_host(listptr, sender_host_cache, NULL, |
| 2065 | (sender_host_address == NULL)? US"" : sender_host_address, NULL); |
| 2066 | } |
| 2067 | |
| 2068 | |
| 2069 | |
| 2070 | |
| 2071 | |
| 2072 | /************************************************* |
| 2073 | * Invert an IP address for a DNS black list * |
| 2074 | *************************************************/ |
| 2075 | |
| 2076 | /* |
| 2077 | Arguments: |
| 2078 | buffer where to put the answer |
| 2079 | address the address to invert |
| 2080 | */ |
| 2081 | |
| 2082 | static void |
| 2083 | invert_address(uschar *buffer, uschar *address) |
| 2084 | { |
| 2085 | int bin[4]; |
| 2086 | uschar *bptr = buffer; |
| 2087 | |
| 2088 | /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer |
| 2089 | to the IPv4 part only. */ |
| 2090 | |
| 2091 | if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7; |
| 2092 | |
| 2093 | /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is |
| 2094 | always 1. */ |
| 2095 | |
| 2096 | if (host_aton(address, bin) == 1) |
| 2097 | { |
| 2098 | int i; |
| 2099 | int x = bin[0]; |
| 2100 | for (i = 0; i < 4; i++) |
| 2101 | { |
| 2102 | sprintf(CS bptr, "%d.", x & 255); |
| 2103 | while (*bptr) bptr++; |
| 2104 | x >>= 8; |
| 2105 | } |
| 2106 | } |
| 2107 | |
| 2108 | /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses |
| 2109 | in any DNS black lists, and the format in which they will be looked up is |
| 2110 | unknown. This is just a guess. */ |
| 2111 | |
| 2112 | #if HAVE_IPV6 |
| 2113 | else |
| 2114 | { |
| 2115 | int i, j; |
| 2116 | for (j = 3; j >= 0; j--) |
| 2117 | { |
| 2118 | int x = bin[j]; |
| 2119 | for (i = 0; i < 8; i++) |
| 2120 | { |
| 2121 | sprintf(CS bptr, "%x.", x & 15); |
| 2122 | while (*bptr) bptr++; |
| 2123 | x >>= 4; |
| 2124 | } |
| 2125 | } |
| 2126 | } |
| 2127 | #endif |
| 2128 | } |
| 2129 | |
| 2130 | |
| 2131 | |
| 2132 | /************************************************* |
| 2133 | * Check host against DNS black lists * |
| 2134 | *************************************************/ |
| 2135 | |
| 2136 | /* This function runs checks against a list of DNS black lists, until one |
| 2137 | matches. Each item on the list can be of the form |
| 2138 | |
| 2139 | domain=ip-address/key |
| 2140 | |
| 2141 | The domain is the right-most domain that is used for the query, for example, |
| 2142 | blackholes.mail-abuse.org. If the IP address is present, there is a match only |
| 2143 | if the DNS lookup returns a matching IP address. Several addresses may be |
| 2144 | given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2. |
| 2145 | |
| 2146 | If no key is given, what is looked up in the domain is the inverted IP address |
| 2147 | of the current client host. If a key is given, it is used to construct the |
| 2148 | domain for the lookup. For example, |
| 2149 | |
| 2150 | dsn.rfc-ignorant.org/$sender_address_domain |
| 2151 | |
| 2152 | After finding a match in the DNS, the domain is placed in $dnslist_domain, and |
| 2153 | then we check for a TXT record for an error message, and if found, save its |
| 2154 | value in $dnslist_text. We also cache everything in a tree, to optimize |
| 2155 | multiple lookups. |
| 2156 | |
| 2157 | Note: an address for testing RBL is 192.203.178.39 |
| 2158 | Note: an address for testing DUL is 192.203.178.4 |
| 2159 | Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org |
| 2160 | |
| 2161 | Arguments: |
| 2162 | listptr the domain/address/data list |
| 2163 | |
| 2164 | Returns: OK successful lookup (i.e. the address is on the list), or |
| 2165 | lookup deferred after +include_unknown |
| 2166 | FAIL name not found, or no data found for the given type, or |
| 2167 | lookup deferred after +exclude_unknown (default) |
| 2168 | DEFER lookup failure, if +defer_unknown was set |
| 2169 | */ |
| 2170 | |
| 2171 | int |
| 2172 | verify_check_dnsbl(uschar **listptr) |
| 2173 | { |
| 2174 | int sep = 0; |
| 2175 | int defer_return = FAIL; |
| 2176 | int old_pool = store_pool; |
| 2177 | BOOL invert_result = FALSE; |
| 2178 | uschar *list = *listptr; |
| 2179 | uschar *domain; |
| 2180 | uschar *s; |
| 2181 | uschar buffer[1024]; |
| 2182 | uschar query[256]; /* DNS domain max length */ |
| 2183 | uschar revadd[128]; /* Long enough for IPv6 address */ |
| 2184 | |
| 2185 | /* Indicate that the inverted IP address is not yet set up */ |
| 2186 | |
| 2187 | revadd[0] = 0; |
| 2188 | |
| 2189 | /* Loop through all the domains supplied, until something matches */ |
| 2190 | |
| 2191 | while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) |
| 2192 | { |
| 2193 | BOOL frc; |
| 2194 | BOOL bitmask = FALSE; |
| 2195 | dns_answer dnsa; |
| 2196 | dns_scan dnss; |
| 2197 | uschar *iplist; |
| 2198 | uschar *key; |
| 2199 | tree_node *t; |
| 2200 | dnsbl_cache_block *cb; |
| 2201 | |
| 2202 | HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain); |
| 2203 | |
| 2204 | /* Deal with special values that change the behaviour on defer */ |
| 2205 | |
| 2206 | if (domain[0] == '+') |
| 2207 | { |
| 2208 | if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK; |
| 2209 | else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL; |
| 2210 | else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER; |
| 2211 | else |
| 2212 | log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s", |
| 2213 | domain); |
| 2214 | continue; |
| 2215 | } |
| 2216 | |
| 2217 | /* See if there's explicit data to be looked up */ |
| 2218 | |
| 2219 | key = Ustrchr(domain, '/'); |
| 2220 | if (key != NULL) *key++ = 0; |
| 2221 | |
| 2222 | /* See if there's a list of addresses supplied after the domain name. This is |
| 2223 | introduced by an = or a & character; if preceded by ! we invert the result. |
| 2224 | */ |
| 2225 | |
| 2226 | iplist = Ustrchr(domain, '='); |
| 2227 | if (iplist == NULL) |
| 2228 | { |
| 2229 | bitmask = TRUE; |
| 2230 | iplist = Ustrchr(domain, '&'); |
| 2231 | } |
| 2232 | |
| 2233 | if (iplist != NULL) |
| 2234 | { |
| 2235 | if (iplist > domain && iplist[-1] == '!') |
| 2236 | { |
| 2237 | invert_result = TRUE; |
| 2238 | iplist[-1] = 0; |
| 2239 | } |
| 2240 | *iplist++ = 0; |
| 2241 | } |
| 2242 | |
| 2243 | /* Check that what we have left is a sensible domain name. There is no reason |
| 2244 | why these domains should in fact use the same syntax as hosts and email |
| 2245 | domains, but in practice they seem to. However, there is little point in |
| 2246 | actually causing an error here, because that would no doubt hold up incoming |
| 2247 | mail. Instead, I'll just log it. */ |
| 2248 | |
| 2249 | for (s = domain; *s != 0; s++) |
| 2250 | { |
| 2251 | if (!isalnum(*s) && *s != '-' && *s != '.') |
| 2252 | { |
| 2253 | log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains " |
| 2254 | "strange characters - is this right?", domain); |
| 2255 | break; |
| 2256 | } |
| 2257 | } |
| 2258 | |
| 2259 | /* Construct the query by adding the domain onto either the sending host |
| 2260 | address, or the given key string. */ |
| 2261 | |
| 2262 | if (key == NULL) |
| 2263 | { |
| 2264 | if (sender_host_address == NULL) return FAIL; /* can never match */ |
| 2265 | if (revadd[0] == 0) invert_address(revadd, sender_host_address); |
| 2266 | frc = string_format(query, sizeof(query), "%s%s", revadd, domain); |
| 2267 | } |
| 2268 | else |
| 2269 | { |
| 2270 | frc = string_format(query, sizeof(query), "%s.%s", key, domain); |
| 2271 | } |
| 2272 | |
| 2273 | if (!frc) |
| 2274 | { |
| 2275 | log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long " |
| 2276 | "(ignored): %s...", query); |
| 2277 | continue; |
| 2278 | } |
| 2279 | |
| 2280 | /* Look for this query in the cache. */ |
| 2281 | |
| 2282 | t = tree_search(dnsbl_cache, query); |
| 2283 | |
| 2284 | /* If not cached from a previous lookup, we must do a DNS lookup, and |
| 2285 | cache the result in permanent memory. */ |
| 2286 | |
| 2287 | if (t == NULL) |
| 2288 | { |
| 2289 | store_pool = POOL_PERM; |
| 2290 | |
| 2291 | /* In case this is the first time the DNS resolver is being used. */ |
| 2292 | |
| 2293 | dns_init(FALSE, FALSE); |
| 2294 | |
| 2295 | /* Set up a tree entry to cache the lookup */ |
| 2296 | |
| 2297 | t = store_get(sizeof(tree_node) + Ustrlen(query)); |
| 2298 | Ustrcpy(t->name, query); |
| 2299 | t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block)); |
| 2300 | (void)tree_insertnode(&dnsbl_cache, t); |
| 2301 | |
| 2302 | /* Do the DNS loopup . */ |
| 2303 | |
| 2304 | HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query); |
| 2305 | cb->rc = dns_basic_lookup(&dnsa, query, T_A); |
| 2306 | cb->text_set = FALSE; |
| 2307 | cb->text = NULL; |
| 2308 | cb->rhs = NULL; |
| 2309 | |
| 2310 | /* If the lookup succeeded, cache the RHS address. The code allows for |
| 2311 | more than one address - this was for complete generality and the possible |
| 2312 | use of A6 records. However, A6 records have been reduced to experimental |
| 2313 | status (August 2001) and may die out. So they may never get used at all, |
| 2314 | let alone in dnsbl records. However, leave the code here, just in case. |
| 2315 | |
| 2316 | Quite apart from one A6 RR generating multiple addresses, there are DNS |
| 2317 | lists that return more than one A record, so we must handle multiple |
| 2318 | addresses generated in that way as well. */ |
| 2319 | |
| 2320 | if (cb->rc == DNS_SUCCEED) |
| 2321 | { |
| 2322 | dns_record *rr; |
| 2323 | dns_address **addrp = &(cb->rhs); |
| 2324 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 2325 | rr != NULL; |
| 2326 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 2327 | { |
| 2328 | if (rr->type == T_A) |
| 2329 | { |
| 2330 | dns_address *da = dns_address_from_rr(&dnsa, rr); |
| 2331 | if (da != NULL) |
| 2332 | { |
| 2333 | *addrp = da; |
| 2334 | while (da->next != NULL) da = da->next; |
| 2335 | addrp = &(da->next); |
| 2336 | } |
| 2337 | } |
| 2338 | } |
| 2339 | |
| 2340 | /* If we didn't find any A records, change the return code. This can |
| 2341 | happen when there is a CNAME record but there are no A records for what |
| 2342 | it points to. */ |
| 2343 | |
| 2344 | if (cb->rhs == NULL) cb->rc = DNS_NODATA; |
| 2345 | } |
| 2346 | |
| 2347 | store_pool = old_pool; |
| 2348 | } |
| 2349 | |
| 2350 | /* Previous lookup was cached */ |
| 2351 | |
| 2352 | else |
| 2353 | { |
| 2354 | HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n"); |
| 2355 | cb = t->data.ptr; |
| 2356 | } |
| 2357 | |
| 2358 | /* We now have the result of the DNS lookup, either newly done, or cached |
| 2359 | from a previous call. If the lookup succeeded, check against the address |
| 2360 | list if there is one. This may be a positive equality list (introduced by |
| 2361 | "="), a negative equality list (introduced by "!="), a positive bitmask |
| 2362 | list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/ |
| 2363 | |
| 2364 | if (cb->rc == DNS_SUCCEED) |
| 2365 | { |
| 2366 | dns_address *da = NULL; |
| 2367 | uschar *addlist = cb->rhs->address; |
| 2368 | |
| 2369 | /* For A and AAAA records, there may be multiple addresses from multiple |
| 2370 | records. For A6 records (currently not expected to be used) there may be |
| 2371 | multiple addresses from a single record. */ |
| 2372 | |
| 2373 | for (da = cb->rhs->next; da != NULL; da = da->next) |
| 2374 | addlist = string_sprintf("%s, %s", addlist, da->address); |
| 2375 | |
| 2376 | HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n", |
| 2377 | query, addlist); |
| 2378 | |
| 2379 | /* Address list check; this can be either for equality, or via a bitmask. |
| 2380 | In the latter case, all the bits must match. */ |
| 2381 | |
| 2382 | if (iplist != NULL) |
| 2383 | { |
| 2384 | int ipsep = ','; |
| 2385 | uschar ip[46]; |
| 2386 | uschar *ptr = iplist; |
| 2387 | |
| 2388 | while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL) |
| 2389 | { |
| 2390 | /* Handle exact matching */ |
| 2391 | if (!bitmask) |
| 2392 | { |
| 2393 | for (da = cb->rhs; da != NULL; da = da->next) |
| 2394 | { |
| 2395 | if (Ustrcmp(CS da->address, ip) == 0) break; |
| 2396 | } |
| 2397 | } |
| 2398 | /* Handle bitmask matching */ |
| 2399 | else |
| 2400 | { |
| 2401 | int address[4]; |
| 2402 | int mask = 0; |
| 2403 | |
| 2404 | /* At present, all known DNS blocking lists use A records, with |
| 2405 | IPv4 addresses on the RHS encoding the information they return. I |
| 2406 | wonder if this will linger on as the last vestige of IPv4 when IPv6 |
| 2407 | is ubiquitous? Anyway, for now we use paranoia code to completely |
| 2408 | ignore IPv6 addresses. The default mask is 0, which always matches. |
| 2409 | We change this only for IPv4 addresses in the list. */ |
| 2410 | |
| 2411 | if (host_aton(ip, address) == 1) mask = address[0]; |
| 2412 | |
| 2413 | /* Scan the returned addresses, skipping any that are IPv6 */ |
| 2414 | |
| 2415 | for (da = cb->rhs; da != NULL; da = da->next) |
| 2416 | { |
| 2417 | if (host_aton(da->address, address) != 1) continue; |
| 2418 | if ((address[0] & mask) == mask) break; |
| 2419 | } |
| 2420 | } |
| 2421 | |
| 2422 | /* Break out if a match has been found */ |
| 2423 | |
| 2424 | if (da != NULL) break; |
| 2425 | } |
| 2426 | |
| 2427 | /* If either |
| 2428 | |
| 2429 | (a) No IP address in a positive list matched, or |
| 2430 | (b) An IP address in a negative list did match |
| 2431 | |
| 2432 | then behave as if the DNSBL lookup had not succeeded, i.e. the host is |
| 2433 | not on the list. */ |
| 2434 | |
| 2435 | if (invert_result != (da == NULL)) |
| 2436 | { |
| 2437 | HDEBUG(D_dnsbl) |
| 2438 | { |
| 2439 | debug_printf("=> but we are not accepting this block class because\n"); |
| 2440 | debug_printf("=> there was %s match for %c%s\n", |
| 2441 | invert_result? "an exclude":"no", bitmask? '&' : '=', iplist); |
| 2442 | } |
| 2443 | continue; /* With next DNSBL domain */ |
| 2444 | } |
| 2445 | } |
| 2446 | |
| 2447 | /* Either there was no IP list, or the record matched. Look up a TXT record |
| 2448 | if it hasn't previously been done. */ |
| 2449 | |
| 2450 | if (!cb->text_set) |
| 2451 | { |
| 2452 | cb->text_set = TRUE; |
| 2453 | if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED) |
| 2454 | { |
| 2455 | dns_record *rr; |
| 2456 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 2457 | rr != NULL; |
| 2458 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 2459 | if (rr->type == T_TXT) break; |
| 2460 | if (rr != NULL) |
| 2461 | { |
| 2462 | int len = (rr->data)[0]; |
| 2463 | if (len > 511) len = 127; |
| 2464 | store_pool = POOL_PERM; |
| 2465 | cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1)); |
| 2466 | store_pool = old_pool; |
| 2467 | } |
| 2468 | } |
| 2469 | } |
| 2470 | |
| 2471 | HDEBUG(D_dnsbl) |
| 2472 | { |
| 2473 | debug_printf("=> that means %s is listed at %s\n", |
| 2474 | (key == NULL)? sender_host_address : key, domain); |
| 2475 | } |
| 2476 | |
| 2477 | dnslist_domain = string_copy(domain); |
| 2478 | dnslist_value = addlist; |
| 2479 | dnslist_text = cb->text; |
| 2480 | return OK; |
| 2481 | } |
| 2482 | |
| 2483 | /* There was a problem with the DNS lookup */ |
| 2484 | |
| 2485 | if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA) |
| 2486 | { |
| 2487 | log_write(L_dnslist_defer, LOG_MAIN, |
| 2488 | "DNS list lookup defer (probably timeout) for %s: %s", query, |
| 2489 | (defer_return == OK)? US"assumed in list" : |
| 2490 | (defer_return == FAIL)? US"assumed not in list" : |
| 2491 | US"returned DEFER"); |
| 2492 | return defer_return; |
| 2493 | } |
| 2494 | |
| 2495 | /* No entry was found in the DNS; continue for next domain */ |
| 2496 | |
| 2497 | HDEBUG(D_dnsbl) |
| 2498 | { |
| 2499 | debug_printf("DNS lookup for %s failed\n", query); |
| 2500 | debug_printf("=> that means %s is not listed at %s\n", |
| 2501 | (key == NULL)? sender_host_address : key, domain); |
| 2502 | } |
| 2503 | } /* Continue with next domain */ |
| 2504 | |
| 2505 | return FAIL; |
| 2506 | } |
| 2507 | |
| 2508 | /* End of verify.c */ |