| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
| 6 | /* See the file NOTICE for conditions of use and distribution. */ |
| 7 | |
| 8 | /* Functions concerned with verifying things. The original code for callout |
| 9 | caching was contributed by Kevin Fleming (but I hacked it around a bit). */ |
| 10 | |
| 11 | |
| 12 | #include "exim.h" |
| 13 | #include "transports/smtp.h" |
| 14 | |
| 15 | #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */ |
| 16 | #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */ |
| 17 | static smtp_outblock ctblock; |
| 18 | uschar ctbuffer[8192]; |
| 19 | |
| 20 | |
| 21 | /* Structure for caching DNSBL lookups */ |
| 22 | |
| 23 | typedef struct dnsbl_cache_block { |
| 24 | time_t expiry; |
| 25 | dns_address *rhs; |
| 26 | uschar *text; |
| 27 | int rc; |
| 28 | BOOL text_set; |
| 29 | } dnsbl_cache_block; |
| 30 | |
| 31 | |
| 32 | /* Anchor for DNSBL cache */ |
| 33 | |
| 34 | static tree_node *dnsbl_cache = NULL; |
| 35 | |
| 36 | |
| 37 | /* Bits for match_type in one_check_dnsbl() */ |
| 38 | |
| 39 | #define MT_NOT 1 |
| 40 | #define MT_ALL 2 |
| 41 | |
| 42 | static uschar cutthrough_response(char, uschar **); |
| 43 | |
| 44 | |
| 45 | /************************************************* |
| 46 | * Retrieve a callout cache record * |
| 47 | *************************************************/ |
| 48 | |
| 49 | /* If a record exists, check whether it has expired. |
| 50 | |
| 51 | Arguments: |
| 52 | dbm_file an open hints file |
| 53 | key the record key |
| 54 | type "address" or "domain" |
| 55 | positive_expire expire time for positive records |
| 56 | negative_expire expire time for negative records |
| 57 | |
| 58 | Returns: the cache record if a non-expired one exists, else NULL |
| 59 | */ |
| 60 | |
| 61 | static dbdata_callout_cache * |
| 62 | get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type, |
| 63 | int positive_expire, int negative_expire) |
| 64 | { |
| 65 | BOOL negative; |
| 66 | int length, expire; |
| 67 | time_t now; |
| 68 | dbdata_callout_cache *cache_record; |
| 69 | |
| 70 | cache_record = dbfn_read_with_length(dbm_file, key, &length); |
| 71 | |
| 72 | if (cache_record == NULL) |
| 73 | { |
| 74 | HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | /* We treat a record as "negative" if its result field is not positive, or if |
| 79 | it is a domain record and the postmaster field is negative. */ |
| 80 | |
| 81 | negative = cache_record->result != ccache_accept || |
| 82 | (type[0] == 'd' && cache_record->postmaster_result == ccache_reject); |
| 83 | expire = negative? negative_expire : positive_expire; |
| 84 | now = time(NULL); |
| 85 | |
| 86 | if (now - cache_record->time_stamp > expire) |
| 87 | { |
| 88 | HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key); |
| 89 | return NULL; |
| 90 | } |
| 91 | |
| 92 | /* If this is a non-reject domain record, check for the obsolete format version |
| 93 | that doesn't have the postmaster and random timestamps, by looking at the |
| 94 | length. If so, copy it to a new-style block, replicating the record's |
| 95 | timestamp. Then check the additional timestamps. (There's no point wasting |
| 96 | effort if connections are rejected.) */ |
| 97 | |
| 98 | if (type[0] == 'd' && cache_record->result != ccache_reject) |
| 99 | { |
| 100 | if (length == sizeof(dbdata_callout_cache_obs)) |
| 101 | { |
| 102 | dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache)); |
| 103 | memcpy(new, cache_record, length); |
| 104 | new->postmaster_stamp = new->random_stamp = new->time_stamp; |
| 105 | cache_record = new; |
| 106 | } |
| 107 | |
| 108 | if (now - cache_record->postmaster_stamp > expire) |
| 109 | cache_record->postmaster_result = ccache_unknown; |
| 110 | |
| 111 | if (now - cache_record->random_stamp > expire) |
| 112 | cache_record->random_result = ccache_unknown; |
| 113 | } |
| 114 | |
| 115 | HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key); |
| 116 | return cache_record; |
| 117 | } |
| 118 | |
| 119 | |
| 120 | |
| 121 | /************************************************* |
| 122 | * Do callout verification for an address * |
| 123 | *************************************************/ |
| 124 | |
| 125 | /* This function is called from verify_address() when the address has routed to |
| 126 | a host list, and a callout has been requested. Callouts are expensive; that is |
| 127 | why a cache is used to improve the efficiency. |
| 128 | |
| 129 | Arguments: |
| 130 | addr the address that's been routed |
| 131 | host_list the list of hosts to try |
| 132 | tf the transport feedback block |
| 133 | |
| 134 | ifstring "interface" option from transport, or NULL |
| 135 | portstring "port" option from transport, or NULL |
| 136 | protocolstring "protocol" option from transport, or NULL |
| 137 | callout the per-command callout timeout |
| 138 | callout_overall the overall callout timeout (if < 0 use 4*callout) |
| 139 | callout_connect the callout connection timeout (if < 0 use callout) |
| 140 | options the verification options - these bits are used: |
| 141 | vopt_is_recipient => this is a recipient address |
| 142 | vopt_callout_no_cache => don't use callout cache |
| 143 | vopt_callout_fullpm => if postmaster check, do full one |
| 144 | vopt_callout_random => do the "random" thing |
| 145 | vopt_callout_recipsender => use real sender for recipient |
| 146 | vopt_callout_recippmaster => use postmaster for recipient |
| 147 | se_mailfrom MAIL FROM address for sender verify; NULL => "" |
| 148 | pm_mailfrom if non-NULL, do the postmaster check with this sender |
| 149 | |
| 150 | Returns: OK/FAIL/DEFER |
| 151 | */ |
| 152 | |
| 153 | static int |
| 154 | do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, |
| 155 | int callout, int callout_overall, int callout_connect, int options, |
| 156 | uschar *se_mailfrom, uschar *pm_mailfrom) |
| 157 | { |
| 158 | BOOL is_recipient = (options & vopt_is_recipient) != 0; |
| 159 | BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0; |
| 160 | BOOL callout_random = (options & vopt_callout_random) != 0; |
| 161 | |
| 162 | int yield = OK; |
| 163 | int old_domain_cache_result = ccache_accept; |
| 164 | BOOL done = FALSE; |
| 165 | uschar *address_key; |
| 166 | uschar *from_address; |
| 167 | uschar *random_local_part = NULL; |
| 168 | const uschar *save_deliver_domain = deliver_domain; |
| 169 | uschar **failure_ptr = is_recipient? |
| 170 | &recipient_verify_failure : &sender_verify_failure; |
| 171 | open_db dbblock; |
| 172 | open_db *dbm_file = NULL; |
| 173 | dbdata_callout_cache new_domain_record; |
| 174 | dbdata_callout_cache_address new_address_record; |
| 175 | host_item *host; |
| 176 | time_t callout_start_time; |
| 177 | uschar peer_offered = 0; |
| 178 | |
| 179 | new_domain_record.result = ccache_unknown; |
| 180 | new_domain_record.postmaster_result = ccache_unknown; |
| 181 | new_domain_record.random_result = ccache_unknown; |
| 182 | |
| 183 | memset(&new_address_record, 0, sizeof(new_address_record)); |
| 184 | |
| 185 | /* For a recipient callout, the key used for the address cache record must |
| 186 | include the sender address if we are using the real sender in the callout, |
| 187 | because that may influence the result of the callout. */ |
| 188 | |
| 189 | address_key = addr->address; |
| 190 | from_address = US""; |
| 191 | |
| 192 | if (is_recipient) |
| 193 | { |
| 194 | if (options & vopt_callout_recipsender) |
| 195 | { |
| 196 | address_key = string_sprintf("%s/<%s>", addr->address, sender_address); |
| 197 | from_address = sender_address; |
| 198 | } |
| 199 | else if (options & vopt_callout_recippmaster) |
| 200 | { |
| 201 | address_key = string_sprintf("%s/<postmaster@%s>", addr->address, |
| 202 | qualify_domain_sender); |
| 203 | from_address = string_sprintf("postmaster@%s", qualify_domain_sender); |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | /* For a sender callout, we must adjust the key if the mailfrom address is not |
| 208 | empty. */ |
| 209 | |
| 210 | else |
| 211 | { |
| 212 | from_address = (se_mailfrom == NULL)? US"" : se_mailfrom; |
| 213 | if (from_address[0] != 0) |
| 214 | address_key = string_sprintf("%s/<%s>", addr->address, from_address); |
| 215 | } |
| 216 | |
| 217 | /* Open the callout cache database, it it exists, for reading only at this |
| 218 | stage, unless caching has been disabled. */ |
| 219 | |
| 220 | if (callout_no_cache) |
| 221 | { |
| 222 | HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n"); |
| 223 | } |
| 224 | else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL) |
| 225 | { |
| 226 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); |
| 227 | } |
| 228 | |
| 229 | /* If a cache database is available see if we can avoid the need to do an |
| 230 | actual callout by making use of previously-obtained data. */ |
| 231 | |
| 232 | if (dbm_file != NULL) |
| 233 | { |
| 234 | dbdata_callout_cache_address *cache_address_record; |
| 235 | dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file, |
| 236 | addr->domain, US"domain", |
| 237 | callout_cache_domain_positive_expire, |
| 238 | callout_cache_domain_negative_expire); |
| 239 | |
| 240 | /* If an unexpired cache record was found for this domain, see if the callout |
| 241 | process can be short-circuited. */ |
| 242 | |
| 243 | if (cache_record != NULL) |
| 244 | { |
| 245 | /* In most cases, if an early command (up to and including MAIL FROM:<>) |
| 246 | was rejected, there is no point carrying on. The callout fails. However, if |
| 247 | we are doing a recipient verification with use_sender or use_postmaster |
| 248 | set, a previous failure of MAIL FROM:<> doesn't count, because this time we |
| 249 | will be using a non-empty sender. We have to remember this situation so as |
| 250 | not to disturb the cached domain value if this whole verification succeeds |
| 251 | (we don't want it turning into "accept"). */ |
| 252 | |
| 253 | old_domain_cache_result = cache_record->result; |
| 254 | |
| 255 | if (cache_record->result == ccache_reject || |
| 256 | (*from_address == 0 && cache_record->result == ccache_reject_mfnull)) |
| 257 | { |
| 258 | setflag(addr, af_verify_nsfail); |
| 259 | HDEBUG(D_verify) |
| 260 | debug_printf("callout cache: domain gave initial rejection, or " |
| 261 | "does not accept HELO or MAIL FROM:<>\n"); |
| 262 | setflag(addr, af_verify_nsfail); |
| 263 | addr->user_message = US"(result of an earlier callout reused)."; |
| 264 | yield = FAIL; |
| 265 | *failure_ptr = US"mail"; |
| 266 | goto END_CALLOUT; |
| 267 | } |
| 268 | |
| 269 | /* If a previous check on a "random" local part was accepted, we assume |
| 270 | that the server does not do any checking on local parts. There is therefore |
| 271 | no point in doing the callout, because it will always be successful. If a |
| 272 | random check previously failed, arrange not to do it again, but preserve |
| 273 | the data in the new record. If a random check is required but hasn't been |
| 274 | done, skip the remaining cache processing. */ |
| 275 | |
| 276 | if (callout_random) switch(cache_record->random_result) |
| 277 | { |
| 278 | case ccache_accept: |
| 279 | HDEBUG(D_verify) |
| 280 | debug_printf("callout cache: domain accepts random addresses\n"); |
| 281 | goto END_CALLOUT; /* Default yield is OK */ |
| 282 | |
| 283 | case ccache_reject: |
| 284 | HDEBUG(D_verify) |
| 285 | debug_printf("callout cache: domain rejects random addresses\n"); |
| 286 | callout_random = FALSE; |
| 287 | new_domain_record.random_result = ccache_reject; |
| 288 | new_domain_record.random_stamp = cache_record->random_stamp; |
| 289 | break; |
| 290 | |
| 291 | default: |
| 292 | HDEBUG(D_verify) |
| 293 | debug_printf("callout cache: need to check random address handling " |
| 294 | "(not cached or cache expired)\n"); |
| 295 | goto END_CACHE; |
| 296 | } |
| 297 | |
| 298 | /* If a postmaster check is requested, but there was a previous failure, |
| 299 | there is again no point in carrying on. If a postmaster check is required, |
| 300 | but has not been done before, we are going to have to do a callout, so skip |
| 301 | remaining cache processing. */ |
| 302 | |
| 303 | if (pm_mailfrom != NULL) |
| 304 | { |
| 305 | if (cache_record->postmaster_result == ccache_reject) |
| 306 | { |
| 307 | setflag(addr, af_verify_pmfail); |
| 308 | HDEBUG(D_verify) |
| 309 | debug_printf("callout cache: domain does not accept " |
| 310 | "RCPT TO:<postmaster@domain>\n"); |
| 311 | yield = FAIL; |
| 312 | *failure_ptr = US"postmaster"; |
| 313 | setflag(addr, af_verify_pmfail); |
| 314 | addr->user_message = US"(result of earlier verification reused)."; |
| 315 | goto END_CALLOUT; |
| 316 | } |
| 317 | if (cache_record->postmaster_result == ccache_unknown) |
| 318 | { |
| 319 | HDEBUG(D_verify) |
| 320 | debug_printf("callout cache: need to check RCPT " |
| 321 | "TO:<postmaster@domain> (not cached or cache expired)\n"); |
| 322 | goto END_CACHE; |
| 323 | } |
| 324 | |
| 325 | /* If cache says OK, set pm_mailfrom NULL to prevent a redundant |
| 326 | postmaster check if the address itself has to be checked. Also ensure |
| 327 | that the value in the cache record is preserved (with its old timestamp). |
| 328 | */ |
| 329 | |
| 330 | HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT " |
| 331 | "TO:<postmaster@domain>\n"); |
| 332 | pm_mailfrom = NULL; |
| 333 | new_domain_record.postmaster_result = ccache_accept; |
| 334 | new_domain_record.postmaster_stamp = cache_record->postmaster_stamp; |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | /* We can't give a result based on information about the domain. See if there |
| 339 | is an unexpired cache record for this specific address (combined with the |
| 340 | sender address if we are doing a recipient callout with a non-empty sender). |
| 341 | */ |
| 342 | |
| 343 | cache_address_record = (dbdata_callout_cache_address *) |
| 344 | get_callout_cache_record(dbm_file, |
| 345 | address_key, US"address", |
| 346 | callout_cache_positive_expire, |
| 347 | callout_cache_negative_expire); |
| 348 | |
| 349 | if (cache_address_record != NULL) |
| 350 | { |
| 351 | if (cache_address_record->result == ccache_accept) |
| 352 | { |
| 353 | HDEBUG(D_verify) |
| 354 | debug_printf("callout cache: address record is positive\n"); |
| 355 | } |
| 356 | else |
| 357 | { |
| 358 | HDEBUG(D_verify) |
| 359 | debug_printf("callout cache: address record is negative\n"); |
| 360 | addr->user_message = US"Previous (cached) callout verification failure"; |
| 361 | *failure_ptr = US"recipient"; |
| 362 | yield = FAIL; |
| 363 | } |
| 364 | goto END_CALLOUT; |
| 365 | } |
| 366 | |
| 367 | /* Close the cache database while we actually do the callout for real. */ |
| 368 | |
| 369 | END_CACHE: |
| 370 | dbfn_close(dbm_file); |
| 371 | dbm_file = NULL; |
| 372 | } |
| 373 | |
| 374 | if (!addr->transport) |
| 375 | { |
| 376 | HDEBUG(D_verify) debug_printf("cannot callout via null transport\n"); |
| 377 | } |
| 378 | else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0) |
| 379 | log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp", |
| 380 | addr->transport->name, addr->transport->driver_name); |
| 381 | else |
| 382 | { |
| 383 | smtp_transport_options_block *ob = |
| 384 | (smtp_transport_options_block *)addr->transport->options_block; |
| 385 | |
| 386 | /* The information wasn't available in the cache, so we have to do a real |
| 387 | callout and save the result in the cache for next time, unless no_cache is set, |
| 388 | or unless we have a previously cached negative random result. If we are to test |
| 389 | with a random local part, ensure that such a local part is available. If not, |
| 390 | log the fact, but carry on without randomming. */ |
| 391 | |
| 392 | if (callout_random && callout_random_local_part != NULL) |
| 393 | if (!(random_local_part = expand_string(callout_random_local_part))) |
| 394 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " |
| 395 | "callout_random_local_part: %s", expand_string_message); |
| 396 | |
| 397 | /* Default the connect and overall callout timeouts if not set, and record the |
| 398 | time we are starting so that we can enforce it. */ |
| 399 | |
| 400 | if (callout_overall < 0) callout_overall = 4 * callout; |
| 401 | if (callout_connect < 0) callout_connect = callout; |
| 402 | callout_start_time = time(NULL); |
| 403 | |
| 404 | /* Before doing a real callout, if this is an SMTP connection, flush the SMTP |
| 405 | output because a callout might take some time. When PIPELINING is active and |
| 406 | there are many recipients, the total time for doing lots of callouts can add up |
| 407 | and cause the client to time out. So in this case we forgo the PIPELINING |
| 408 | optimization. */ |
| 409 | |
| 410 | if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush(); |
| 411 | |
| 412 | /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first, |
| 413 | and we are holding a cutthrough conn open, we can just append the rcpt to |
| 414 | that conn for verification purposes (and later delivery also). Simplest |
| 415 | coding means skipping this whole loop and doing the append separately. |
| 416 | |
| 417 | We will need to remember it has been appended so that rcpt-acl tail code |
| 418 | can do it there for the non-rcpt-verify case. For this we keep an addresscount. |
| 419 | */ |
| 420 | |
| 421 | /* Can we re-use an open cutthrough connection? */ |
| 422 | if ( cutthrough.fd >= 0 |
| 423 | && (options & (vopt_callout_recipsender | vopt_callout_recippmaster)) |
| 424 | == vopt_callout_recipsender |
| 425 | && !random_local_part |
| 426 | && !pm_mailfrom |
| 427 | ) |
| 428 | { |
| 429 | if (addr->transport == cutthrough.addr.transport) |
| 430 | for (host = host_list; host; host = host->next) |
| 431 | if (Ustrcmp(host->address, cutthrough.host.address) == 0) |
| 432 | { |
| 433 | int host_af; |
| 434 | uschar *interface = NULL; /* Outgoing interface to use; NULL => any */ |
| 435 | int port = 25; |
| 436 | |
| 437 | deliver_host = host->name; |
| 438 | deliver_host_address = host->address; |
| 439 | deliver_host_port = host->port; |
| 440 | deliver_domain = addr->domain; |
| 441 | transport_name = addr->transport->name; |
| 442 | |
| 443 | host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6; |
| 444 | |
| 445 | if (!smtp_get_interface(tf->interface, host_af, addr, &interface, |
| 446 | US"callout") || |
| 447 | !smtp_get_port(tf->port, addr, &port, US"callout")) |
| 448 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address, |
| 449 | addr->message); |
| 450 | |
| 451 | if ( ( interface == cutthrough.interface |
| 452 | || ( interface |
| 453 | && cutthrough.interface |
| 454 | && Ustrcmp(interface, cutthrough.interface) == 0 |
| 455 | ) ) |
| 456 | && port == cutthrough.host.port |
| 457 | ) |
| 458 | { |
| 459 | uschar * resp = NULL; |
| 460 | |
| 461 | /* Match! Send the RCPT TO, append the addr, set done */ |
| 462 | done = |
| 463 | smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n", |
| 464 | transport_rcpt_address(addr, |
| 465 | (addr->transport == NULL)? FALSE : |
| 466 | addr->transport->rcpt_include_affixes)) >= 0 && |
| 467 | cutthrough_response('2', &resp) == '2'; |
| 468 | |
| 469 | /* This would go horribly wrong if a callout fail was ignored by ACL. |
| 470 | We punt by abandoning cutthrough on a reject, like the |
| 471 | first-rcpt does. */ |
| 472 | |
| 473 | if (done) |
| 474 | { |
| 475 | address_item * na = store_get(sizeof(address_item)); |
| 476 | *na = cutthrough.addr; |
| 477 | cutthrough.addr = *addr; |
| 478 | cutthrough.addr.host_used = &cutthrough.host; |
| 479 | cutthrough.addr.next = na; |
| 480 | |
| 481 | cutthrough.nrcpt++; |
| 482 | } |
| 483 | else |
| 484 | { |
| 485 | cancel_cutthrough_connection("recipient rejected"); |
| 486 | if (!resp || errno == ETIMEDOUT) |
| 487 | { |
| 488 | HDEBUG(D_verify) debug_printf("SMTP timeout\n"); |
| 489 | } |
| 490 | else if (errno == 0) |
| 491 | { |
| 492 | if (*resp == 0) |
| 493 | Ustrcpy(resp, US"connection dropped"); |
| 494 | |
| 495 | addr->message = |
| 496 | string_sprintf("response to \"%s\" from %s [%s] was: %s", |
| 497 | big_buffer, host->name, host->address, |
| 498 | string_printing(resp)); |
| 499 | |
| 500 | addr->user_message = |
| 501 | string_sprintf("Callout verification failed:\n%s", resp); |
| 502 | |
| 503 | /* Hard rejection ends the process */ |
| 504 | |
| 505 | if (resp[0] == '5') /* Address rejected */ |
| 506 | { |
| 507 | yield = FAIL; |
| 508 | done = TRUE; |
| 509 | } |
| 510 | } |
| 511 | } |
| 512 | } |
| 513 | break; |
| 514 | } |
| 515 | if (!done) |
| 516 | cancel_cutthrough_connection("incompatible connection"); |
| 517 | } |
| 518 | |
| 519 | /* Now make connections to the hosts and do real callouts. The list of hosts |
| 520 | is passed in as an argument. */ |
| 521 | |
| 522 | for (host = host_list; host != NULL && !done; host = host->next) |
| 523 | { |
| 524 | smtp_inblock inblock; |
| 525 | smtp_outblock outblock; |
| 526 | int host_af; |
| 527 | int port = 25; |
| 528 | BOOL send_quit = TRUE; |
| 529 | uschar *active_hostname = smtp_active_hostname; |
| 530 | BOOL lmtp; |
| 531 | BOOL smtps; |
| 532 | BOOL esmtp; |
| 533 | BOOL suppress_tls = FALSE; |
| 534 | uschar *interface = NULL; /* Outgoing interface to use; NULL => any */ |
| 535 | #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE) |
| 536 | BOOL dane = FALSE; |
| 537 | BOOL dane_required; |
| 538 | dns_answer tlsa_dnsa; |
| 539 | #endif |
| 540 | uschar inbuffer[4096]; |
| 541 | uschar outbuffer[1024]; |
| 542 | uschar responsebuffer[4096]; |
| 543 | uschar * size_str; |
| 544 | |
| 545 | clearflag(addr, af_verify_pmfail); /* postmaster callout flag */ |
| 546 | clearflag(addr, af_verify_nsfail); /* null sender callout flag */ |
| 547 | |
| 548 | /* Skip this host if we don't have an IP address for it. */ |
| 549 | |
| 550 | if (host->address == NULL) |
| 551 | { |
| 552 | DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n", |
| 553 | host->name); |
| 554 | continue; |
| 555 | } |
| 556 | |
| 557 | /* Check the overall callout timeout */ |
| 558 | |
| 559 | if (time(NULL) - callout_start_time >= callout_overall) |
| 560 | { |
| 561 | HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n"); |
| 562 | break; |
| 563 | } |
| 564 | |
| 565 | /* Set IPv4 or IPv6 */ |
| 566 | |
| 567 | host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6; |
| 568 | |
| 569 | /* Expand and interpret the interface and port strings. The latter will not |
| 570 | be used if there is a host-specific port (e.g. from a manualroute router). |
| 571 | This has to be delayed till now, because they may expand differently for |
| 572 | different hosts. If there's a failure, log it, but carry on with the |
| 573 | defaults. */ |
| 574 | |
| 575 | deliver_host = host->name; |
| 576 | deliver_host_address = host->address; |
| 577 | deliver_host_port = host->port; |
| 578 | deliver_domain = addr->domain; |
| 579 | transport_name = addr->transport->name; |
| 580 | |
| 581 | if ( !smtp_get_interface(tf->interface, host_af, addr, &interface, |
| 582 | US"callout") |
| 583 | || !smtp_get_port(tf->port, addr, &port, US"callout") |
| 584 | ) |
| 585 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address, |
| 586 | addr->message); |
| 587 | |
| 588 | /* Set HELO string according to the protocol */ |
| 589 | lmtp= Ustrcmp(tf->protocol, "lmtp") == 0; |
| 590 | smtps= Ustrcmp(tf->protocol, "smtps") == 0; |
| 591 | |
| 592 | |
| 593 | HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port); |
| 594 | |
| 595 | /* Set up the buffer for reading SMTP response packets. */ |
| 596 | |
| 597 | inblock.buffer = inbuffer; |
| 598 | inblock.buffersize = sizeof(inbuffer); |
| 599 | inblock.ptr = inbuffer; |
| 600 | inblock.ptrend = inbuffer; |
| 601 | |
| 602 | /* Set up the buffer for holding SMTP commands while pipelining */ |
| 603 | |
| 604 | outblock.buffer = outbuffer; |
| 605 | outblock.buffersize = sizeof(outbuffer); |
| 606 | outblock.ptr = outbuffer; |
| 607 | outblock.cmd_count = 0; |
| 608 | outblock.authenticating = FALSE; |
| 609 | |
| 610 | /* Connect to the host; on failure, just loop for the next one, but we |
| 611 | set the error for the last one. Use the callout_connect timeout. */ |
| 612 | |
| 613 | tls_retry_connection: |
| 614 | |
| 615 | /* Reset the parameters of a TLS session */ |
| 616 | tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL; |
| 617 | |
| 618 | inblock.sock = outblock.sock = |
| 619 | smtp_connect(host, host_af, port, interface, callout_connect, |
| 620 | addr->transport); |
| 621 | if (inblock.sock < 0) |
| 622 | { |
| 623 | addr->message = string_sprintf("could not connect to %s [%s]: %s", |
| 624 | host->name, host->address, strerror(errno)); |
| 625 | transport_name = NULL; |
| 626 | deliver_host = deliver_host_address = NULL; |
| 627 | deliver_domain = save_deliver_domain; |
| 628 | continue; |
| 629 | } |
| 630 | |
| 631 | #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE) |
| 632 | { |
| 633 | int rc; |
| 634 | |
| 635 | tls_out.dane_verified = FALSE; |
| 636 | tls_out.tlsa_usage = 0; |
| 637 | |
| 638 | dane_required = |
| 639 | verify_check_given_host(&ob->hosts_require_dane, host) == OK; |
| 640 | |
| 641 | if (host->dnssec == DS_YES) |
| 642 | { |
| 643 | if( ( dane_required |
| 644 | || verify_check_given_host(&ob->hosts_try_dane, host) == OK |
| 645 | ) |
| 646 | && (rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK |
| 647 | ) |
| 648 | return rc; |
| 649 | } |
| 650 | else if (dane_required) |
| 651 | { |
| 652 | log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name); |
| 653 | return FAIL; |
| 654 | } |
| 655 | |
| 656 | if (dane) |
| 657 | ob->tls_tempfail_tryclear = FALSE; |
| 658 | } |
| 659 | #endif /*DANE*/ |
| 660 | |
| 661 | /* Expand the helo_data string to find the host name to use. */ |
| 662 | |
| 663 | if (tf->helo_data != NULL) |
| 664 | { |
| 665 | uschar *s = expand_string(tf->helo_data); |
| 666 | if (s == NULL) |
| 667 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's " |
| 668 | "helo_data value for callout: %s", addr->address, |
| 669 | expand_string_message); |
| 670 | else active_hostname = s; |
| 671 | } |
| 672 | |
| 673 | /* Wait for initial response, and send HELO. The smtp_write_command() |
| 674 | function leaves its command in big_buffer. This is used in error responses. |
| 675 | Initialize it in case the connection is rejected. */ |
| 676 | |
| 677 | Ustrcpy(big_buffer, "initial connection"); |
| 678 | |
| 679 | /* Unless ssl-on-connect, wait for the initial greeting */ |
| 680 | smtps_redo_greeting: |
| 681 | |
| 682 | #ifdef SUPPORT_TLS |
| 683 | if (!smtps || (smtps && tls_out.active >= 0)) |
| 684 | #endif |
| 685 | { |
| 686 | if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))) |
| 687 | goto RESPONSE_FAILED; |
| 688 | |
| 689 | #ifndef DISABLE_EVENT |
| 690 | lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes" |
| 691 | : host->dnssec==DS_NO ? US"no" : NULL; |
| 692 | if (event_raise(addr->transport->event_action, |
| 693 | US"smtp:connect", responsebuffer)) |
| 694 | { |
| 695 | lookup_dnssec_authenticated = NULL; |
| 696 | /* Logging? Debug? */ |
| 697 | goto RESPONSE_FAILED; |
| 698 | } |
| 699 | lookup_dnssec_authenticated = NULL; |
| 700 | #endif |
| 701 | } |
| 702 | |
| 703 | /* Not worth checking greeting line for ESMTP support */ |
| 704 | if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK)) |
| 705 | DEBUG(D_transport) |
| 706 | debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n"); |
| 707 | |
| 708 | tls_redo_helo: |
| 709 | |
| 710 | #ifdef SUPPORT_TLS |
| 711 | if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */ |
| 712 | { |
| 713 | peer_offered &= ~PEER_OFFERED_TLS; |
| 714 | ob->tls_tempfail_tryclear = FALSE; |
| 715 | } |
| 716 | else /* all other cases */ |
| 717 | #endif |
| 718 | |
| 719 | { esmtp_retry: |
| 720 | |
| 721 | if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n", |
| 722 | !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0)) |
| 723 | goto SEND_FAILED; |
| 724 | if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)) |
| 725 | { |
| 726 | if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0) |
| 727 | { |
| 728 | done= FALSE; |
| 729 | goto RESPONSE_FAILED; |
| 730 | } |
| 731 | #ifdef SUPPORT_TLS |
| 732 | peer_offered &= ~PEER_OFFERED_TLS; |
| 733 | #endif |
| 734 | esmtp = FALSE; |
| 735 | goto esmtp_retry; /* fallback to HELO */ |
| 736 | } |
| 737 | |
| 738 | /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */ |
| 739 | |
| 740 | peer_offered = esmtp |
| 741 | ? ehlo_response(responsebuffer, sizeof(responsebuffer), |
| 742 | (!suppress_tls && tls_out.active < 0 ? PEER_OFFERED_TLS : 0) |
| 743 | | 0 /* no IGNQ */ |
| 744 | | 0 /* no PRDR */ |
| 745 | #ifdef SUPPORT_I18N |
| 746 | | (addr->prop.utf8_msg && !addr->prop.utf8_downcvt |
| 747 | ? PEER_OFFERED_UTF8 : 0) |
| 748 | #endif |
| 749 | | 0 /* no DSN */ |
| 750 | | 0 /* no PIPE */ |
| 751 | |
| 752 | /* only care about SIZE if we have size from inbound */ |
| 753 | | (message_size > 0 && ob->size_addition >= 0 |
| 754 | ? PEER_OFFERED_SIZE : 0) |
| 755 | ) |
| 756 | : 0; |
| 757 | } |
| 758 | |
| 759 | size_str = peer_offered & PEER_OFFERED_SIZE |
| 760 | ? string_sprintf(" SIZE=%d", message_size + ob->size_addition) : US""; |
| 761 | |
| 762 | #ifdef SUPPORT_TLS |
| 763 | tls_offered = !!(peer_offered & PEER_OFFERED_TLS); |
| 764 | #endif |
| 765 | |
| 766 | /* If TLS is available on this connection attempt to |
| 767 | start up a TLS session, unless the host is in hosts_avoid_tls. If successful, |
| 768 | send another EHLO - the server may give a different answer in secure mode. We |
| 769 | use a separate buffer for reading the response to STARTTLS so that if it is |
| 770 | negative, the original EHLO data is available for subsequent analysis, should |
| 771 | the client not be required to use TLS. If the response is bad, copy the buffer |
| 772 | for error analysis. */ |
| 773 | |
| 774 | #ifdef SUPPORT_TLS |
| 775 | if ( peer_offered & PEER_OFFERED_TLS |
| 776 | && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK |
| 777 | && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK |
| 778 | ) |
| 779 | { |
| 780 | uschar buffer2[4096]; |
| 781 | if ( !smtps |
| 782 | && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0)) |
| 783 | goto SEND_FAILED; |
| 784 | |
| 785 | /* If there is an I/O error, transmission of this message is deferred. If |
| 786 | there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is |
| 787 | false, we also defer. However, if there is a temporary rejection of STARTTLS |
| 788 | and tls_tempfail_tryclear is true, or if there is an outright rejection of |
| 789 | STARTTLS, we carry on. This means we will try to send the message in clear, |
| 790 | unless the host is in hosts_require_tls (tested below). */ |
| 791 | |
| 792 | if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2', |
| 793 | ob->command_timeout)) |
| 794 | { |
| 795 | if (errno != 0 || buffer2[0] == 0 || |
| 796 | (buffer2[0] == '4' && !ob->tls_tempfail_tryclear)) |
| 797 | { |
| 798 | Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer)); |
| 799 | done= FALSE; |
| 800 | goto RESPONSE_FAILED; |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */ |
| 805 | else |
| 806 | { |
| 807 | int oldtimeout = ob->command_timeout; |
| 808 | int rc; |
| 809 | |
| 810 | tls_negotiate: |
| 811 | ob->command_timeout = callout; |
| 812 | rc = tls_client_start(inblock.sock, host, addr, addr->transport |
| 813 | # ifdef EXPERIMENTAL_DANE |
| 814 | , dane ? &tlsa_dnsa : NULL |
| 815 | # endif |
| 816 | ); |
| 817 | ob->command_timeout = oldtimeout; |
| 818 | |
| 819 | /* TLS negotiation failed; give an error. Try in clear on a new |
| 820 | connection, if the options permit it for this host. */ |
| 821 | if (rc != OK) |
| 822 | { |
| 823 | if (rc == DEFER) |
| 824 | { |
| 825 | (void)close(inblock.sock); |
| 826 | # ifndef DISABLE_EVENT |
| 827 | (void) event_raise(addr->transport->event_action, |
| 828 | US"tcp:close", NULL); |
| 829 | # endif |
| 830 | # ifdef EXPERIMENTAL_DANE |
| 831 | if (dane) |
| 832 | { |
| 833 | if (!dane_required) |
| 834 | { |
| 835 | log_write(0, LOG_MAIN, "DANE attempt failed;" |
| 836 | " trying CA-root TLS to %s [%s] (not in hosts_require_dane)", |
| 837 | host->name, host->address); |
| 838 | dane = FALSE; |
| 839 | goto tls_negotiate; |
| 840 | } |
| 841 | } |
| 842 | else |
| 843 | # endif |
| 844 | if ( ob->tls_tempfail_tryclear |
| 845 | && !smtps |
| 846 | && verify_check_given_host(&ob->hosts_require_tls, host) != OK |
| 847 | ) |
| 848 | { |
| 849 | log_write(0, LOG_MAIN, "TLS session failure:" |
| 850 | " delivering unencrypted to %s [%s] (not in hosts_require_tls)", |
| 851 | host->name, host->address); |
| 852 | suppress_tls = TRUE; |
| 853 | goto tls_retry_connection; |
| 854 | } |
| 855 | } |
| 856 | |
| 857 | /*save_errno = ERRNO_TLSFAILURE;*/ |
| 858 | /*message = US"failure while setting up TLS session";*/ |
| 859 | send_quit = FALSE; |
| 860 | done= FALSE; |
| 861 | goto TLS_FAILED; |
| 862 | } |
| 863 | |
| 864 | /* TLS session is set up. Copy info for logging. */ |
| 865 | addr->cipher = tls_out.cipher; |
| 866 | addr->peerdn = tls_out.peerdn; |
| 867 | |
| 868 | /* For SMTPS we need to wait for the initial OK response, then do HELO. */ |
| 869 | if (smtps) |
| 870 | goto smtps_redo_greeting; |
| 871 | |
| 872 | /* For STARTTLS we need to redo EHLO */ |
| 873 | goto tls_redo_helo; |
| 874 | } |
| 875 | } |
| 876 | |
| 877 | /* If the host is required to use a secure channel, ensure that we have one. */ |
| 878 | if (tls_out.active < 0) |
| 879 | if ( |
| 880 | # ifdef EXPERIMENTAL_DANE |
| 881 | dane || |
| 882 | # endif |
| 883 | verify_check_given_host(&ob->hosts_require_tls, host) == OK |
| 884 | ) |
| 885 | { |
| 886 | /*save_errno = ERRNO_TLSREQUIRED;*/ |
| 887 | log_write(0, LOG_MAIN, |
| 888 | "H=%s [%s]: a TLS session is required for this host, but %s", |
| 889 | host->name, host->address, |
| 890 | peer_offered & PEER_OFFERED_TLS |
| 891 | ? "an attempt to start TLS failed" |
| 892 | : "the server did not offer TLS support"); |
| 893 | done= FALSE; |
| 894 | goto TLS_FAILED; |
| 895 | } |
| 896 | |
| 897 | #endif /*SUPPORT_TLS*/ |
| 898 | |
| 899 | done = TRUE; /* so far so good; have response to HELO */ |
| 900 | |
| 901 | /* For now, transport_filter by cutthrough-delivery is not supported */ |
| 902 | /* Need proper integration with the proper transport mechanism. */ |
| 903 | if (cutthrough.delivery) |
| 904 | { |
| 905 | if (addr->transport->filter_command) |
| 906 | { |
| 907 | cutthrough.delivery = FALSE; |
| 908 | HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n"); |
| 909 | } |
| 910 | #ifndef DISABLE_DKIM |
| 911 | if (ob->dkim_domain) |
| 912 | { |
| 913 | cutthrough.delivery = FALSE; |
| 914 | HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n"); |
| 915 | } |
| 916 | #endif |
| 917 | } |
| 918 | |
| 919 | SEND_FAILED: |
| 920 | RESPONSE_FAILED: |
| 921 | TLS_FAILED: |
| 922 | ; |
| 923 | /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */ |
| 924 | |
| 925 | /* Failure to accept HELO is cached; this blocks the whole domain for all |
| 926 | senders. I/O errors and defer responses are not cached. */ |
| 927 | |
| 928 | if (!done) |
| 929 | { |
| 930 | *failure_ptr = US"mail"; /* At or before MAIL */ |
| 931 | if (errno == 0 && responsebuffer[0] == '5') |
| 932 | { |
| 933 | setflag(addr, af_verify_nsfail); |
| 934 | new_domain_record.result = ccache_reject; |
| 935 | } |
| 936 | } |
| 937 | |
| 938 | #ifdef SUPPORT_I18N |
| 939 | else if ( addr->prop.utf8_msg |
| 940 | && !addr->prop.utf8_downcvt |
| 941 | && !(peer_offered & PEER_OFFERED_UTF8) |
| 942 | ) |
| 943 | { |
| 944 | HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n"); |
| 945 | errno = ERRNO_UTF8_FWD; |
| 946 | setflag(addr, af_verify_nsfail); |
| 947 | done = FALSE; |
| 948 | } |
| 949 | else if ( addr->prop.utf8_msg |
| 950 | && (addr->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8)) |
| 951 | && (setflag(addr, af_utf8_downcvt), |
| 952 | from_address = string_address_utf8_to_alabel(from_address, |
| 953 | &addr->message), |
| 954 | addr->message |
| 955 | ) ) |
| 956 | { |
| 957 | errno = ERRNO_EXPANDFAIL; |
| 958 | setflag(addr, af_verify_nsfail); |
| 959 | done = FALSE; |
| 960 | } |
| 961 | #endif |
| 962 | |
| 963 | /* If we haven't authenticated, but are required to, give up. */ |
| 964 | /* Try to AUTH */ |
| 965 | |
| 966 | else done = smtp_auth(responsebuffer, sizeof(responsebuffer), |
| 967 | addr, host, ob, esmtp, &inblock, &outblock) == OK && |
| 968 | |
| 969 | /* Copy AUTH info for logging */ |
| 970 | ( (addr->authenticator = client_authenticator), |
| 971 | (addr->auth_id = client_authenticated_id), |
| 972 | |
| 973 | /* Build a mail-AUTH string (re-using responsebuffer for convenience */ |
| 974 | !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob) |
| 975 | ) && |
| 976 | |
| 977 | ( (addr->auth_sndr = client_authenticated_sender), |
| 978 | |
| 979 | /* Send the MAIL command */ |
| 980 | (smtp_write_command(&outblock, FALSE, |
| 981 | #ifdef SUPPORT_I18N |
| 982 | addr->prop.utf8_msg && !addr->prop.utf8_downcvt |
| 983 | ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n" |
| 984 | : |
| 985 | #endif |
| 986 | "MAIL FROM:<%s>%s%s\r\n", |
| 987 | from_address, responsebuffer, size_str) >= 0) |
| 988 | ) && |
| 989 | |
| 990 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 991 | '2', callout); |
| 992 | |
| 993 | deliver_host = deliver_host_address = NULL; |
| 994 | deliver_domain = save_deliver_domain; |
| 995 | |
| 996 | /* If the host does not accept MAIL FROM:<>, arrange to cache this |
| 997 | information, but again, don't record anything for an I/O error or a defer. Do |
| 998 | not cache rejections of MAIL when a non-empty sender has been used, because |
| 999 | that blocks the whole domain for all senders. */ |
| 1000 | |
| 1001 | if (!done) |
| 1002 | { |
| 1003 | *failure_ptr = US"mail"; /* At or before MAIL */ |
| 1004 | if (errno == 0 && responsebuffer[0] == '5') |
| 1005 | { |
| 1006 | setflag(addr, af_verify_nsfail); |
| 1007 | if (from_address[0] == 0) |
| 1008 | new_domain_record.result = ccache_reject_mfnull; |
| 1009 | } |
| 1010 | } |
| 1011 | |
| 1012 | /* Otherwise, proceed to check a "random" address (if required), then the |
| 1013 | given address, and the postmaster address (if required). Between each check, |
| 1014 | issue RSET, because some servers accept only one recipient after MAIL |
| 1015 | FROM:<>. |
| 1016 | |
| 1017 | Before doing this, set the result in the domain cache record to "accept", |
| 1018 | unless its previous value was ccache_reject_mfnull. In that case, the domain |
| 1019 | rejects MAIL FROM:<> and we want to continue to remember that. When that is |
| 1020 | the case, we have got here only in the case of a recipient verification with |
| 1021 | a non-null sender. */ |
| 1022 | |
| 1023 | else |
| 1024 | { |
| 1025 | const uschar * rcpt_domain = addr->domain; |
| 1026 | |
| 1027 | #ifdef SUPPORT_I18N |
| 1028 | uschar * errstr = NULL; |
| 1029 | if ( testflag(addr, af_utf8_downcvt) |
| 1030 | && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain, |
| 1031 | &errstr), errstr) |
| 1032 | ) |
| 1033 | { |
| 1034 | addr->message = errstr; |
| 1035 | errno = ERRNO_EXPANDFAIL; |
| 1036 | setflag(addr, af_verify_nsfail); |
| 1037 | done = FALSE; |
| 1038 | rcpt_domain = US""; /*XXX errorhandling! */ |
| 1039 | } |
| 1040 | #endif |
| 1041 | |
| 1042 | new_domain_record.result = |
| 1043 | (old_domain_cache_result == ccache_reject_mfnull)? |
| 1044 | ccache_reject_mfnull: ccache_accept; |
| 1045 | |
| 1046 | /* Do the random local part check first */ |
| 1047 | |
| 1048 | if (random_local_part != NULL) |
| 1049 | { |
| 1050 | uschar randombuffer[1024]; |
| 1051 | BOOL random_ok = |
| 1052 | smtp_write_command(&outblock, FALSE, |
| 1053 | "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part, |
| 1054 | rcpt_domain) >= 0 && |
| 1055 | smtp_read_response(&inblock, randombuffer, |
| 1056 | sizeof(randombuffer), '2', callout); |
| 1057 | |
| 1058 | /* Remember when we last did a random test */ |
| 1059 | |
| 1060 | new_domain_record.random_stamp = time(NULL); |
| 1061 | |
| 1062 | /* If accepted, we aren't going to do any further tests below. */ |
| 1063 | |
| 1064 | if (random_ok) |
| 1065 | new_domain_record.random_result = ccache_accept; |
| 1066 | |
| 1067 | /* Otherwise, cache a real negative response, and get back to the right |
| 1068 | state to send RCPT. Unless there's some problem such as a dropped |
| 1069 | connection, we expect to succeed, because the commands succeeded above. |
| 1070 | However, some servers drop the connection after responding to an |
| 1071 | invalid recipient, so on (any) error we drop and remake the connection. |
| 1072 | */ |
| 1073 | |
| 1074 | else if (errno == 0) |
| 1075 | { |
| 1076 | /* This would be ok for 1st rcpt a cutthrough, but no way to |
| 1077 | handle a subsequent. So refuse to support any */ |
| 1078 | cancel_cutthrough_connection("random-recipient"); |
| 1079 | |
| 1080 | if (randombuffer[0] == '5') |
| 1081 | new_domain_record.random_result = ccache_reject; |
| 1082 | |
| 1083 | done = |
| 1084 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && |
| 1085 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 1086 | '2', callout) && |
| 1087 | |
| 1088 | smtp_write_command(&outblock, FALSE, |
| 1089 | #ifdef SUPPORT_I18N |
| 1090 | addr->prop.utf8_msg && !addr->prop.utf8_downcvt |
| 1091 | ? "MAIL FROM:<%s> SMTPUTF8\r\n" |
| 1092 | : |
| 1093 | #endif |
| 1094 | "MAIL FROM:<%s>\r\n", |
| 1095 | from_address) >= 0 && |
| 1096 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 1097 | '2', callout); |
| 1098 | |
| 1099 | if (!done) |
| 1100 | { |
| 1101 | HDEBUG(D_acl|D_v) |
| 1102 | debug_printf("problem after random/rset/mfrom; reopen conn\n"); |
| 1103 | random_local_part = NULL; |
| 1104 | #ifdef SUPPORT_TLS |
| 1105 | tls_close(FALSE, TRUE); |
| 1106 | #endif |
| 1107 | (void)close(inblock.sock); |
| 1108 | #ifndef DISABLE_EVENT |
| 1109 | (void) event_raise(addr->transport->event_action, |
| 1110 | US"tcp:close", NULL); |
| 1111 | #endif |
| 1112 | goto tls_retry_connection; |
| 1113 | } |
| 1114 | } |
| 1115 | else done = FALSE; /* Some timeout/connection problem */ |
| 1116 | } /* Random check */ |
| 1117 | |
| 1118 | /* If the host is accepting all local parts, as determined by the "random" |
| 1119 | check, we don't need to waste time doing any further checking. */ |
| 1120 | |
| 1121 | if (new_domain_record.random_result != ccache_accept && done) |
| 1122 | { |
| 1123 | /* Get the rcpt_include_affixes flag from the transport if there is one, |
| 1124 | but assume FALSE if there is not. */ |
| 1125 | |
| 1126 | uschar * rcpt = transport_rcpt_address(addr, |
| 1127 | addr->transport ? addr->transport->rcpt_include_affixes : FALSE); |
| 1128 | |
| 1129 | #ifdef SUPPORT_I18N |
| 1130 | /*XXX should the conversion be moved into transport_rcpt_address() ? */ |
| 1131 | uschar * dummy_errstr = NULL; |
| 1132 | if ( testflag(addr, af_utf8_downcvt) |
| 1133 | && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr), |
| 1134 | dummy_errstr |
| 1135 | ) ) |
| 1136 | { |
| 1137 | errno = ERRNO_EXPANDFAIL; |
| 1138 | *failure_ptr = US"recipient"; |
| 1139 | done = FALSE; |
| 1140 | } |
| 1141 | else |
| 1142 | #endif |
| 1143 | |
| 1144 | done = |
| 1145 | smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n", |
| 1146 | rcpt) >= 0 && |
| 1147 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), |
| 1148 | '2', callout); |
| 1149 | |
| 1150 | if (done) |
| 1151 | new_address_record.result = ccache_accept; |
| 1152 | else if (errno == 0 && responsebuffer[0] == '5') |
| 1153 | { |
| 1154 | *failure_ptr = US"recipient"; |
| 1155 | new_address_record.result = ccache_reject; |
| 1156 | } |
| 1157 | |
| 1158 | /* Do postmaster check if requested; if a full check is required, we |
| 1159 | check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */ |
| 1160 | |
| 1161 | if (done && pm_mailfrom != NULL) |
| 1162 | { |
| 1163 | /* Could possibly shift before main verify, just above, and be ok |
| 1164 | for cutthrough. But no way to handle a subsequent rcpt, so just |
| 1165 | refuse any */ |
| 1166 | cancel_cutthrough_connection("postmaster verify"); |
| 1167 | HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n"); |
| 1168 | |
| 1169 | done = |
| 1170 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && |
| 1171 | smtp_read_response(&inblock, responsebuffer, |
| 1172 | sizeof(responsebuffer), '2', callout) && |
| 1173 | |
| 1174 | smtp_write_command(&outblock, FALSE, |
| 1175 | "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 && |
| 1176 | smtp_read_response(&inblock, responsebuffer, |
| 1177 | sizeof(responsebuffer), '2', callout) && |
| 1178 | |
| 1179 | /* First try using the current domain */ |
| 1180 | |
| 1181 | (( |
| 1182 | smtp_write_command(&outblock, FALSE, |
| 1183 | "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 && |
| 1184 | smtp_read_response(&inblock, responsebuffer, |
| 1185 | sizeof(responsebuffer), '2', callout) |
| 1186 | ) |
| 1187 | |
| 1188 | || |
| 1189 | |
| 1190 | /* If that doesn't work, and a full check is requested, |
| 1191 | try without the domain. */ |
| 1192 | |
| 1193 | ( |
| 1194 | (options & vopt_callout_fullpm) != 0 && |
| 1195 | smtp_write_command(&outblock, FALSE, |
| 1196 | "RCPT TO:<postmaster>\r\n") >= 0 && |
| 1197 | smtp_read_response(&inblock, responsebuffer, |
| 1198 | sizeof(responsebuffer), '2', callout) |
| 1199 | )); |
| 1200 | |
| 1201 | /* Sort out the cache record */ |
| 1202 | |
| 1203 | new_domain_record.postmaster_stamp = time(NULL); |
| 1204 | |
| 1205 | if (done) |
| 1206 | new_domain_record.postmaster_result = ccache_accept; |
| 1207 | else if (errno == 0 && responsebuffer[0] == '5') |
| 1208 | { |
| 1209 | *failure_ptr = US"postmaster"; |
| 1210 | setflag(addr, af_verify_pmfail); |
| 1211 | new_domain_record.postmaster_result = ccache_reject; |
| 1212 | } |
| 1213 | } |
| 1214 | } /* Random not accepted */ |
| 1215 | } /* MAIL FROM: accepted */ |
| 1216 | |
| 1217 | /* For any failure of the main check, other than a negative response, we just |
| 1218 | close the connection and carry on. We can identify a negative response by the |
| 1219 | fact that errno is zero. For I/O errors it will be non-zero |
| 1220 | |
| 1221 | Set up different error texts for logging and for sending back to the caller |
| 1222 | as an SMTP response. Log in all cases, using a one-line format. For sender |
| 1223 | callouts, give a full response to the caller, but for recipient callouts, |
| 1224 | don't give the IP address because this may be an internal host whose identity |
| 1225 | is not to be widely broadcast. */ |
| 1226 | |
| 1227 | if (!done) |
| 1228 | { |
| 1229 | if (errno == ETIMEDOUT) |
| 1230 | { |
| 1231 | HDEBUG(D_verify) debug_printf("SMTP timeout\n"); |
| 1232 | send_quit = FALSE; |
| 1233 | } |
| 1234 | #ifdef SUPPORT_I18N |
| 1235 | else if (errno == ERRNO_UTF8_FWD) |
| 1236 | { |
| 1237 | extern int acl_where; /* src/acl.c */ |
| 1238 | errno = 0; |
| 1239 | addr->message = string_sprintf( |
| 1240 | "response to \"%s\" from %s [%s] did not include SMTPUTF8", |
| 1241 | big_buffer, host->name, host->address); |
| 1242 | addr->user_message = acl_where == ACL_WHERE_RCPT |
| 1243 | ? US"533 mailbox name not allowed" |
| 1244 | : US"550 mailbox unavailable"; |
| 1245 | yield = FAIL; |
| 1246 | done = TRUE; |
| 1247 | } |
| 1248 | #endif |
| 1249 | else if (errno == 0) |
| 1250 | { |
| 1251 | if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped"); |
| 1252 | |
| 1253 | addr->message = |
| 1254 | string_sprintf("response to \"%s\" from %s [%s] was: %s", |
| 1255 | big_buffer, host->name, host->address, |
| 1256 | string_printing(responsebuffer)); |
| 1257 | |
| 1258 | addr->user_message = is_recipient? |
| 1259 | string_sprintf("Callout verification failed:\n%s", responsebuffer) |
| 1260 | : |
| 1261 | string_sprintf("Called: %s\nSent: %s\nResponse: %s", |
| 1262 | host->address, big_buffer, responsebuffer); |
| 1263 | |
| 1264 | /* Hard rejection ends the process */ |
| 1265 | |
| 1266 | if (responsebuffer[0] == '5') /* Address rejected */ |
| 1267 | { |
| 1268 | yield = FAIL; |
| 1269 | done = TRUE; |
| 1270 | } |
| 1271 | } |
| 1272 | } |
| 1273 | |
| 1274 | /* End the SMTP conversation and close the connection. */ |
| 1275 | |
| 1276 | /* Cutthrough - on a successfull connect and recipient-verify with |
| 1277 | use-sender and we are 1st rcpt and have no cutthrough conn so far |
| 1278 | here is where we want to leave the conn open */ |
| 1279 | if ( cutthrough.delivery |
| 1280 | && rcpt_count == 1 |
| 1281 | && done |
| 1282 | && yield == OK |
| 1283 | && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender |
| 1284 | && !random_local_part |
| 1285 | && !pm_mailfrom |
| 1286 | && cutthrough.fd < 0 |
| 1287 | && !lmtp |
| 1288 | ) |
| 1289 | { |
| 1290 | cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */ |
| 1291 | cutthrough.nrcpt = 1; |
| 1292 | cutthrough.interface = interface; |
| 1293 | cutthrough.host = *host; |
| 1294 | cutthrough.addr = *addr; /* Save the address_item for later logging */ |
| 1295 | cutthrough.addr.next = NULL; |
| 1296 | cutthrough.addr.host_used = &cutthrough.host; |
| 1297 | if (addr->parent) |
| 1298 | *(cutthrough.addr.parent = store_get(sizeof(address_item))) = |
| 1299 | *addr->parent; |
| 1300 | ctblock.buffer = ctbuffer; |
| 1301 | ctblock.buffersize = sizeof(ctbuffer); |
| 1302 | ctblock.ptr = ctbuffer; |
| 1303 | /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */ |
| 1304 | ctblock.sock = cutthrough.fd; |
| 1305 | } |
| 1306 | else |
| 1307 | { |
| 1308 | /* Ensure no cutthrough on multiple address verifies */ |
| 1309 | if (options & vopt_callout_recipsender) |
| 1310 | cancel_cutthrough_connection("multiple verify calls"); |
| 1311 | if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n"); |
| 1312 | |
| 1313 | #ifdef SUPPORT_TLS |
| 1314 | tls_close(FALSE, TRUE); |
| 1315 | #endif |
| 1316 | (void)close(inblock.sock); |
| 1317 | #ifndef DISABLE_EVENT |
| 1318 | (void) event_raise(addr->transport->event_action, US"tcp:close", NULL); |
| 1319 | #endif |
| 1320 | } |
| 1321 | |
| 1322 | } /* Loop through all hosts, while !done */ |
| 1323 | } |
| 1324 | |
| 1325 | /* If we get here with done == TRUE, a successful callout happened, and yield |
| 1326 | will be set OK or FAIL according to the response to the RCPT command. |
| 1327 | Otherwise, we looped through the hosts but couldn't complete the business. |
| 1328 | However, there may be domain-specific information to cache in both cases. |
| 1329 | |
| 1330 | The value of the result field in the new_domain record is ccache_unknown if |
| 1331 | there was an error before or with MAIL FROM:, and errno was not zero, |
| 1332 | implying some kind of I/O error. We don't want to write the cache in that case. |
| 1333 | Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */ |
| 1334 | |
| 1335 | if (!callout_no_cache && new_domain_record.result != ccache_unknown) |
| 1336 | { |
| 1337 | if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)) |
| 1338 | == NULL) |
| 1339 | { |
| 1340 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); |
| 1341 | } |
| 1342 | else |
| 1343 | { |
| 1344 | (void)dbfn_write(dbm_file, addr->domain, &new_domain_record, |
| 1345 | (int)sizeof(dbdata_callout_cache)); |
| 1346 | HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n" |
| 1347 | " result=%d postmaster=%d random=%d\n", |
| 1348 | new_domain_record.result, |
| 1349 | new_domain_record.postmaster_result, |
| 1350 | new_domain_record.random_result); |
| 1351 | } |
| 1352 | } |
| 1353 | |
| 1354 | /* If a definite result was obtained for the callout, cache it unless caching |
| 1355 | is disabled. */ |
| 1356 | |
| 1357 | if (done) |
| 1358 | { |
| 1359 | if (!callout_no_cache && new_address_record.result != ccache_unknown) |
| 1360 | { |
| 1361 | if (dbm_file == NULL) |
| 1362 | dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); |
| 1363 | if (dbm_file == NULL) |
| 1364 | { |
| 1365 | HDEBUG(D_verify) debug_printf("no callout cache available\n"); |
| 1366 | } |
| 1367 | else |
| 1368 | { |
| 1369 | (void)dbfn_write(dbm_file, address_key, &new_address_record, |
| 1370 | (int)sizeof(dbdata_callout_cache_address)); |
| 1371 | HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n", |
| 1372 | (new_address_record.result == ccache_accept)? "positive" : "negative"); |
| 1373 | } |
| 1374 | } |
| 1375 | } /* done */ |
| 1376 | |
| 1377 | /* Failure to connect to any host, or any response other than 2xx or 5xx is a |
| 1378 | temporary error. If there was only one host, and a response was received, leave |
| 1379 | it alone if supplying details. Otherwise, give a generic response. */ |
| 1380 | |
| 1381 | else /* !done */ |
| 1382 | { |
| 1383 | uschar *dullmsg = string_sprintf("Could not complete %s verify callout", |
| 1384 | is_recipient? "recipient" : "sender"); |
| 1385 | yield = DEFER; |
| 1386 | |
| 1387 | if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg; |
| 1388 | |
| 1389 | addr->user_message = (!smtp_return_error_details)? dullmsg : |
| 1390 | string_sprintf("%s for <%s>.\n" |
| 1391 | "The mail server(s) for the domain may be temporarily unreachable, or\n" |
| 1392 | "they may be permanently unreachable from this server. In the latter case,\n%s", |
| 1393 | dullmsg, addr->address, |
| 1394 | is_recipient? |
| 1395 | "the address will never be accepted." |
| 1396 | : |
| 1397 | "you need to change the address or create an MX record for its domain\n" |
| 1398 | "if it is supposed to be generally accessible from the Internet.\n" |
| 1399 | "Talk to your mail administrator for details."); |
| 1400 | |
| 1401 | /* Force a specific error code */ |
| 1402 | |
| 1403 | addr->basic_errno = ERRNO_CALLOUTDEFER; |
| 1404 | } |
| 1405 | |
| 1406 | /* Come here from within the cache-reading code on fast-track exit. */ |
| 1407 | |
| 1408 | END_CALLOUT: |
| 1409 | if (dbm_file != NULL) dbfn_close(dbm_file); |
| 1410 | return yield; |
| 1411 | } |
| 1412 | |
| 1413 | |
| 1414 | |
| 1415 | /* Called after recipient-acl to get a cutthrough connection open when |
| 1416 | one was requested and a recipient-verify wasn't subsequently done. |
| 1417 | */ |
| 1418 | int |
| 1419 | open_cutthrough_connection( address_item * addr ) |
| 1420 | { |
| 1421 | address_item addr2; |
| 1422 | int rc; |
| 1423 | |
| 1424 | /* Use a recipient-verify-callout to set up the cutthrough connection. */ |
| 1425 | /* We must use a copy of the address for verification, because it might |
| 1426 | get rewritten. */ |
| 1427 | |
| 1428 | addr2 = *addr; |
| 1429 | HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n", |
| 1430 | rcpt_count > 1 ? "more" : "start"); |
| 1431 | rc= verify_address(&addr2, NULL, |
| 1432 | vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache, |
| 1433 | CUTTHROUGH_CMD_TIMEOUT, -1, -1, |
| 1434 | NULL, NULL, NULL); |
| 1435 | HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n"); |
| 1436 | return rc; |
| 1437 | } |
| 1438 | |
| 1439 | |
| 1440 | |
| 1441 | /* Send given number of bytes from the buffer */ |
| 1442 | static BOOL |
| 1443 | cutthrough_send(int n) |
| 1444 | { |
| 1445 | if(cutthrough.fd < 0) |
| 1446 | return TRUE; |
| 1447 | |
| 1448 | if( |
| 1449 | #ifdef SUPPORT_TLS |
| 1450 | (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) : |
| 1451 | #endif |
| 1452 | send(cutthrough.fd, ctblock.buffer, n, 0) > 0 |
| 1453 | ) |
| 1454 | { |
| 1455 | transport_count += n; |
| 1456 | ctblock.ptr= ctblock.buffer; |
| 1457 | return TRUE; |
| 1458 | } |
| 1459 | |
| 1460 | HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno)); |
| 1461 | return FALSE; |
| 1462 | } |
| 1463 | |
| 1464 | |
| 1465 | |
| 1466 | static BOOL |
| 1467 | _cutthrough_puts(uschar * cp, int n) |
| 1468 | { |
| 1469 | while(n--) |
| 1470 | { |
| 1471 | if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize) |
| 1472 | if(!cutthrough_send(ctblock.buffersize)) |
| 1473 | return FALSE; |
| 1474 | |
| 1475 | *ctblock.ptr++ = *cp++; |
| 1476 | } |
| 1477 | return TRUE; |
| 1478 | } |
| 1479 | |
| 1480 | /* Buffered output of counted data block. Return boolean success */ |
| 1481 | BOOL |
| 1482 | cutthrough_puts(uschar * cp, int n) |
| 1483 | { |
| 1484 | if (cutthrough.fd < 0) return TRUE; |
| 1485 | if (_cutthrough_puts(cp, n)) return TRUE; |
| 1486 | cancel_cutthrough_connection("transmit failed"); |
| 1487 | return FALSE; |
| 1488 | } |
| 1489 | |
| 1490 | |
| 1491 | static BOOL |
| 1492 | _cutthrough_flush_send(void) |
| 1493 | { |
| 1494 | int n= ctblock.ptr-ctblock.buffer; |
| 1495 | |
| 1496 | if(n>0) |
| 1497 | if(!cutthrough_send(n)) |
| 1498 | return FALSE; |
| 1499 | return TRUE; |
| 1500 | } |
| 1501 | |
| 1502 | |
| 1503 | /* Send out any bufferred output. Return boolean success. */ |
| 1504 | BOOL |
| 1505 | cutthrough_flush_send(void) |
| 1506 | { |
| 1507 | if (_cutthrough_flush_send()) return TRUE; |
| 1508 | cancel_cutthrough_connection("transmit failed"); |
| 1509 | return FALSE; |
| 1510 | } |
| 1511 | |
| 1512 | |
| 1513 | BOOL |
| 1514 | cutthrough_put_nl(void) |
| 1515 | { |
| 1516 | return cutthrough_puts(US"\r\n", 2); |
| 1517 | } |
| 1518 | |
| 1519 | |
| 1520 | /* Get and check response from cutthrough target */ |
| 1521 | static uschar |
| 1522 | cutthrough_response(char expect, uschar ** copy) |
| 1523 | { |
| 1524 | smtp_inblock inblock; |
| 1525 | uschar inbuffer[4096]; |
| 1526 | uschar responsebuffer[4096]; |
| 1527 | |
| 1528 | inblock.buffer = inbuffer; |
| 1529 | inblock.buffersize = sizeof(inbuffer); |
| 1530 | inblock.ptr = inbuffer; |
| 1531 | inblock.ptrend = inbuffer; |
| 1532 | inblock.sock = cutthrough.fd; |
| 1533 | /* this relies on (inblock.sock == tls_out.active) */ |
| 1534 | if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT)) |
| 1535 | cancel_cutthrough_connection("target timeout on read"); |
| 1536 | |
| 1537 | if(copy != NULL) |
| 1538 | { |
| 1539 | uschar * cp; |
| 1540 | *copy = cp = string_copy(responsebuffer); |
| 1541 | /* Trim the trailing end of line */ |
| 1542 | cp += Ustrlen(responsebuffer); |
| 1543 | if(cp > *copy && cp[-1] == '\n') *--cp = '\0'; |
| 1544 | if(cp > *copy && cp[-1] == '\r') *--cp = '\0'; |
| 1545 | } |
| 1546 | |
| 1547 | return responsebuffer[0]; |
| 1548 | } |
| 1549 | |
| 1550 | |
| 1551 | /* Negotiate dataphase with the cutthrough target, returning success boolean */ |
| 1552 | BOOL |
| 1553 | cutthrough_predata(void) |
| 1554 | { |
| 1555 | if(cutthrough.fd < 0) |
| 1556 | return FALSE; |
| 1557 | |
| 1558 | HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n"); |
| 1559 | cutthrough_puts(US"DATA\r\n", 6); |
| 1560 | cutthrough_flush_send(); |
| 1561 | |
| 1562 | /* Assume nothing buffered. If it was it gets ignored. */ |
| 1563 | return cutthrough_response('3', NULL) == '3'; |
| 1564 | } |
| 1565 | |
| 1566 | |
| 1567 | /* fd and use_crlf args only to match write_chunk() */ |
| 1568 | static BOOL |
| 1569 | cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf) |
| 1570 | { |
| 1571 | uschar * s2; |
| 1572 | while(s && (s2 = Ustrchr(s, '\n'))) |
| 1573 | { |
| 1574 | if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl()) |
| 1575 | return FALSE; |
| 1576 | s = s2+1; |
| 1577 | } |
| 1578 | return TRUE; |
| 1579 | } |
| 1580 | |
| 1581 | |
| 1582 | /* Buffered send of headers. Return success boolean. */ |
| 1583 | /* Expands newlines to wire format (CR,NL). */ |
| 1584 | /* Also sends header-terminating blank line. */ |
| 1585 | BOOL |
| 1586 | cutthrough_headers_send(void) |
| 1587 | { |
| 1588 | if(cutthrough.fd < 0) |
| 1589 | return FALSE; |
| 1590 | |
| 1591 | /* We share a routine with the mainline transport to handle header add/remove/rewrites, |
| 1592 | but having a separate buffered-output function (for now) |
| 1593 | */ |
| 1594 | HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n"); |
| 1595 | |
| 1596 | if (!transport_headers_send(&cutthrough.addr, cutthrough.fd, |
| 1597 | cutthrough.addr.transport->add_headers, |
| 1598 | cutthrough.addr.transport->remove_headers, |
| 1599 | &cutthrough_write_chunk, TRUE, |
| 1600 | cutthrough.addr.transport->rewrite_rules, |
| 1601 | cutthrough.addr.transport->rewrite_existflags)) |
| 1602 | return FALSE; |
| 1603 | |
| 1604 | HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n"); |
| 1605 | return TRUE; |
| 1606 | } |
| 1607 | |
| 1608 | |
| 1609 | static void |
| 1610 | close_cutthrough_connection(const char * why) |
| 1611 | { |
| 1612 | if(cutthrough.fd >= 0) |
| 1613 | { |
| 1614 | /* We could be sending this after a bunch of data, but that is ok as |
| 1615 | the only way to cancel the transfer in dataphase is to drop the tcp |
| 1616 | conn before the final dot. |
| 1617 | */ |
| 1618 | ctblock.ptr = ctbuffer; |
| 1619 | HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n"); |
| 1620 | _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */ |
| 1621 | _cutthrough_flush_send(); |
| 1622 | /* No wait for response */ |
| 1623 | |
| 1624 | #ifdef SUPPORT_TLS |
| 1625 | tls_close(FALSE, TRUE); |
| 1626 | #endif |
| 1627 | (void)close(cutthrough.fd); |
| 1628 | cutthrough.fd = -1; |
| 1629 | HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why); |
| 1630 | } |
| 1631 | ctblock.ptr = ctbuffer; |
| 1632 | } |
| 1633 | |
| 1634 | void |
| 1635 | cancel_cutthrough_connection(const char * why) |
| 1636 | { |
| 1637 | close_cutthrough_connection(why); |
| 1638 | cutthrough.delivery = FALSE; |
| 1639 | } |
| 1640 | |
| 1641 | |
| 1642 | |
| 1643 | |
| 1644 | /* Have senders final-dot. Send one to cutthrough target, and grab the response. |
| 1645 | Log an OK response as a transmission. |
| 1646 | Close the connection. |
| 1647 | Return smtp response-class digit. |
| 1648 | */ |
| 1649 | uschar * |
| 1650 | cutthrough_finaldot(void) |
| 1651 | { |
| 1652 | uschar res; |
| 1653 | address_item * addr; |
| 1654 | HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n"); |
| 1655 | |
| 1656 | /* Assume data finshed with new-line */ |
| 1657 | if( !cutthrough_puts(US".", 1) |
| 1658 | || !cutthrough_put_nl() |
| 1659 | || !cutthrough_flush_send() |
| 1660 | ) |
| 1661 | return cutthrough.addr.message; |
| 1662 | |
| 1663 | res = cutthrough_response('2', &cutthrough.addr.message); |
| 1664 | for (addr = &cutthrough.addr; addr; addr = addr->next) |
| 1665 | { |
| 1666 | addr->message = cutthrough.addr.message; |
| 1667 | switch(res) |
| 1668 | { |
| 1669 | case '2': |
| 1670 | delivery_log(LOG_MAIN, addr, (int)'>', NULL); |
| 1671 | close_cutthrough_connection("delivered"); |
| 1672 | break; |
| 1673 | |
| 1674 | case '4': |
| 1675 | delivery_log(LOG_MAIN, addr, 0, |
| 1676 | US"tmp-reject from cutthrough after DATA:"); |
| 1677 | break; |
| 1678 | |
| 1679 | case '5': |
| 1680 | delivery_log(LOG_MAIN|LOG_REJECT, addr, 0, |
| 1681 | US"rejected after DATA:"); |
| 1682 | break; |
| 1683 | |
| 1684 | default: |
| 1685 | break; |
| 1686 | } |
| 1687 | } |
| 1688 | return cutthrough.addr.message; |
| 1689 | } |
| 1690 | |
| 1691 | |
| 1692 | |
| 1693 | /************************************************* |
| 1694 | * Copy error to toplevel address * |
| 1695 | *************************************************/ |
| 1696 | |
| 1697 | /* This function is used when a verify fails or defers, to ensure that the |
| 1698 | failure or defer information is in the original toplevel address. This applies |
| 1699 | when an address is redirected to a single new address, and the failure or |
| 1700 | deferral happens to the child address. |
| 1701 | |
| 1702 | Arguments: |
| 1703 | vaddr the verify address item |
| 1704 | addr the final address item |
| 1705 | yield FAIL or DEFER |
| 1706 | |
| 1707 | Returns: the value of YIELD |
| 1708 | */ |
| 1709 | |
| 1710 | static int |
| 1711 | copy_error(address_item *vaddr, address_item *addr, int yield) |
| 1712 | { |
| 1713 | if (addr != vaddr) |
| 1714 | { |
| 1715 | vaddr->message = addr->message; |
| 1716 | vaddr->user_message = addr->user_message; |
| 1717 | vaddr->basic_errno = addr->basic_errno; |
| 1718 | vaddr->more_errno = addr->more_errno; |
| 1719 | vaddr->prop.address_data = addr->prop.address_data; |
| 1720 | copyflag(vaddr, addr, af_pass_message); |
| 1721 | } |
| 1722 | return yield; |
| 1723 | } |
| 1724 | |
| 1725 | |
| 1726 | |
| 1727 | |
| 1728 | /************************************************** |
| 1729 | * printf that automatically handles TLS if needed * |
| 1730 | ***************************************************/ |
| 1731 | |
| 1732 | /* This function is used by verify_address() as a substitute for all fprintf() |
| 1733 | calls; a direct fprintf() will not produce output in a TLS SMTP session, such |
| 1734 | as a response to an EXPN command. smtp_in.c makes smtp_printf available but |
| 1735 | that assumes that we always use the smtp_out FILE* when not using TLS or the |
| 1736 | ssl buffer when we are. Instead we take a FILE* parameter and check to see if |
| 1737 | that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular |
| 1738 | fprintf(). |
| 1739 | |
| 1740 | Arguments: |
| 1741 | f the candidate FILE* to write to |
| 1742 | format format string |
| 1743 | ... optional arguments |
| 1744 | |
| 1745 | Returns: |
| 1746 | nothing |
| 1747 | */ |
| 1748 | |
| 1749 | static void PRINTF_FUNCTION(2,3) |
| 1750 | respond_printf(FILE *f, const char *format, ...) |
| 1751 | { |
| 1752 | va_list ap; |
| 1753 | |
| 1754 | va_start(ap, format); |
| 1755 | if (smtp_out && (f == smtp_out)) |
| 1756 | smtp_vprintf(format, ap); |
| 1757 | else |
| 1758 | vfprintf(f, format, ap); |
| 1759 | va_end(ap); |
| 1760 | } |
| 1761 | |
| 1762 | |
| 1763 | |
| 1764 | /************************************************* |
| 1765 | * Verify an email address * |
| 1766 | *************************************************/ |
| 1767 | |
| 1768 | /* This function is used both for verification (-bv and at other times) and |
| 1769 | address testing (-bt), which is indicated by address_test_mode being set. |
| 1770 | |
| 1771 | Arguments: |
| 1772 | vaddr contains the address to verify; the next field in this block |
| 1773 | must be NULL |
| 1774 | f if not NULL, write the result to this file |
| 1775 | options various option bits: |
| 1776 | vopt_fake_sender => this sender verify is not for the real |
| 1777 | sender (it was verify=sender=xxxx or an address from a |
| 1778 | header line) - rewriting must not change sender_address |
| 1779 | vopt_is_recipient => this is a recipient address, otherwise |
| 1780 | it's a sender address - this affects qualification and |
| 1781 | rewriting and messages from callouts |
| 1782 | vopt_qualify => qualify an unqualified address; else error |
| 1783 | vopt_expn => called from SMTP EXPN command |
| 1784 | vopt_success_on_redirect => when a new address is generated |
| 1785 | the verification instantly succeeds |
| 1786 | |
| 1787 | These ones are used by do_callout() -- the options variable |
| 1788 | is passed to it. |
| 1789 | |
| 1790 | vopt_callout_fullpm => if postmaster check, do full one |
| 1791 | vopt_callout_no_cache => don't use callout cache |
| 1792 | vopt_callout_random => do the "random" thing |
| 1793 | vopt_callout_recipsender => use real sender for recipient |
| 1794 | vopt_callout_recippmaster => use postmaster for recipient |
| 1795 | |
| 1796 | callout if > 0, specifies that callout is required, and gives timeout |
| 1797 | for individual commands |
| 1798 | callout_overall if > 0, gives overall timeout for the callout function; |
| 1799 | if < 0, a default is used (see do_callout()) |
| 1800 | callout_connect the connection timeout for callouts |
| 1801 | se_mailfrom when callout is requested to verify a sender, use this |
| 1802 | in MAIL FROM; NULL => "" |
| 1803 | pm_mailfrom when callout is requested, if non-NULL, do the postmaster |
| 1804 | thing and use this as the sender address (may be "") |
| 1805 | |
| 1806 | routed if not NULL, set TRUE if routing succeeded, so we can |
| 1807 | distinguish between routing failed and callout failed |
| 1808 | |
| 1809 | Returns: OK address verified |
| 1810 | FAIL address failed to verify |
| 1811 | DEFER can't tell at present |
| 1812 | */ |
| 1813 | |
| 1814 | int |
| 1815 | verify_address(address_item *vaddr, FILE *f, int options, int callout, |
| 1816 | int callout_overall, int callout_connect, uschar *se_mailfrom, |
| 1817 | uschar *pm_mailfrom, BOOL *routed) |
| 1818 | { |
| 1819 | BOOL allok = TRUE; |
| 1820 | BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0); |
| 1821 | BOOL is_recipient = (options & vopt_is_recipient) != 0; |
| 1822 | BOOL expn = (options & vopt_expn) != 0; |
| 1823 | BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0; |
| 1824 | int i; |
| 1825 | int yield = OK; |
| 1826 | int verify_type = expn? v_expn : |
| 1827 | address_test_mode? v_none : |
| 1828 | is_recipient? v_recipient : v_sender; |
| 1829 | address_item *addr_list; |
| 1830 | address_item *addr_new = NULL; |
| 1831 | address_item *addr_remote = NULL; |
| 1832 | address_item *addr_local = NULL; |
| 1833 | address_item *addr_succeed = NULL; |
| 1834 | uschar **failure_ptr = is_recipient? |
| 1835 | &recipient_verify_failure : &sender_verify_failure; |
| 1836 | uschar *ko_prefix, *cr; |
| 1837 | uschar *address = vaddr->address; |
| 1838 | uschar *save_sender; |
| 1839 | uschar null_sender[] = { 0 }; /* Ensure writeable memory */ |
| 1840 | |
| 1841 | /* Clear, just in case */ |
| 1842 | |
| 1843 | *failure_ptr = NULL; |
| 1844 | |
| 1845 | /* Set up a prefix and suffix for error message which allow us to use the same |
| 1846 | output statements both in EXPN mode (where an SMTP response is needed) and when |
| 1847 | debugging with an output file. */ |
| 1848 | |
| 1849 | if (expn) |
| 1850 | { |
| 1851 | ko_prefix = US"553 "; |
| 1852 | cr = US"\r"; |
| 1853 | } |
| 1854 | else ko_prefix = cr = US""; |
| 1855 | |
| 1856 | /* Add qualify domain if permitted; otherwise an unqualified address fails. */ |
| 1857 | |
| 1858 | if (parse_find_at(address) == NULL) |
| 1859 | { |
| 1860 | if ((options & vopt_qualify) == 0) |
| 1861 | { |
| 1862 | if (f != NULL) |
| 1863 | respond_printf(f, "%sA domain is required for \"%s\"%s\n", |
| 1864 | ko_prefix, address, cr); |
| 1865 | *failure_ptr = US"qualify"; |
| 1866 | return FAIL; |
| 1867 | } |
| 1868 | address = rewrite_address_qualify(address, is_recipient); |
| 1869 | } |
| 1870 | |
| 1871 | DEBUG(D_verify) |
| 1872 | { |
| 1873 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 1874 | debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address); |
| 1875 | } |
| 1876 | |
| 1877 | /* Rewrite and report on it. Clear the domain and local part caches - these |
| 1878 | may have been set by domains and local part tests during an ACL. */ |
| 1879 | |
| 1880 | if (global_rewrite_rules != NULL) |
| 1881 | { |
| 1882 | uschar *old = address; |
| 1883 | address = rewrite_address(address, is_recipient, FALSE, |
| 1884 | global_rewrite_rules, rewrite_existflags); |
| 1885 | if (address != old) |
| 1886 | { |
| 1887 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0; |
| 1888 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0; |
| 1889 | if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address); |
| 1890 | } |
| 1891 | } |
| 1892 | |
| 1893 | /* If this is the real sender address, we must update sender_address at |
| 1894 | this point, because it may be referred to in the routers. */ |
| 1895 | |
| 1896 | if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0) |
| 1897 | sender_address = address; |
| 1898 | |
| 1899 | /* If the address was rewritten to <> no verification can be done, and we have |
| 1900 | to return OK. This rewriting is permitted only for sender addresses; for other |
| 1901 | addresses, such rewriting fails. */ |
| 1902 | |
| 1903 | if (address[0] == 0) return OK; |
| 1904 | |
| 1905 | /* Flip the legacy TLS-related variables over to the outbound set in case |
| 1906 | they're used in the context of a transport used by verification. Reset them |
| 1907 | at exit from this routine. */ |
| 1908 | |
| 1909 | tls_modify_variables(&tls_out); |
| 1910 | |
| 1911 | /* Save a copy of the sender address for re-instating if we change it to <> |
| 1912 | while verifying a sender address (a nice bit of self-reference there). */ |
| 1913 | |
| 1914 | save_sender = sender_address; |
| 1915 | |
| 1916 | /* Update the address structure with the possibly qualified and rewritten |
| 1917 | address. Set it up as the starting address on the chain of new addresses. */ |
| 1918 | |
| 1919 | vaddr->address = address; |
| 1920 | addr_new = vaddr; |
| 1921 | |
| 1922 | /* We need a loop, because an address can generate new addresses. We must also |
| 1923 | cope with generated pipes and files at the top level. (See also the code and |
| 1924 | comment in deliver.c.) However, it is usually the case that the router for |
| 1925 | user's .forward files has its verify flag turned off. |
| 1926 | |
| 1927 | If an address generates more than one child, the loop is used only when |
| 1928 | full_info is set, and this can only be set locally. Remote enquiries just get |
| 1929 | information about the top level address, not anything that it generated. */ |
| 1930 | |
| 1931 | while (addr_new != NULL) |
| 1932 | { |
| 1933 | int rc; |
| 1934 | address_item *addr = addr_new; |
| 1935 | |
| 1936 | addr_new = addr->next; |
| 1937 | addr->next = NULL; |
| 1938 | |
| 1939 | DEBUG(D_verify) |
| 1940 | { |
| 1941 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 1942 | debug_printf("Considering %s\n", addr->address); |
| 1943 | } |
| 1944 | |
| 1945 | /* Handle generated pipe, file or reply addresses. We don't get these |
| 1946 | when handling EXPN, as it does only one level of expansion. */ |
| 1947 | |
| 1948 | if (testflag(addr, af_pfr)) |
| 1949 | { |
| 1950 | allok = FALSE; |
| 1951 | if (f != NULL) |
| 1952 | { |
| 1953 | BOOL allow; |
| 1954 | |
| 1955 | if (addr->address[0] == '>') |
| 1956 | { |
| 1957 | allow = testflag(addr, af_allow_reply); |
| 1958 | fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1); |
| 1959 | } |
| 1960 | else |
| 1961 | { |
| 1962 | allow = (addr->address[0] == '|')? |
| 1963 | testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file); |
| 1964 | fprintf(f, "%s -> %s", addr->parent->address, addr->address); |
| 1965 | } |
| 1966 | |
| 1967 | if (addr->basic_errno == ERRNO_BADTRANSPORT) |
| 1968 | fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n" |
| 1969 | "%s\n", addr->message); |
| 1970 | else if (allow) |
| 1971 | fprintf(f, "\n transport = %s\n", addr->transport->name); |
| 1972 | else |
| 1973 | fprintf(f, " *** forbidden ***\n"); |
| 1974 | } |
| 1975 | continue; |
| 1976 | } |
| 1977 | |
| 1978 | /* Just in case some router parameter refers to it. */ |
| 1979 | |
| 1980 | return_path = (addr->prop.errors_address != NULL)? |
| 1981 | addr->prop.errors_address : sender_address; |
| 1982 | |
| 1983 | /* Split the address into domain and local part, handling the %-hack if |
| 1984 | necessary, and then route it. While routing a sender address, set |
| 1985 | $sender_address to <> because that is what it will be if we were trying to |
| 1986 | send a bounce to the sender. */ |
| 1987 | |
| 1988 | if (routed != NULL) *routed = FALSE; |
| 1989 | if ((rc = deliver_split_address(addr)) == OK) |
| 1990 | { |
| 1991 | if (!is_recipient) sender_address = null_sender; |
| 1992 | rc = route_address(addr, &addr_local, &addr_remote, &addr_new, |
| 1993 | &addr_succeed, verify_type); |
| 1994 | sender_address = save_sender; /* Put back the real sender */ |
| 1995 | } |
| 1996 | |
| 1997 | /* If routing an address succeeded, set the flag that remembers, for use when |
| 1998 | an ACL cached a sender verify (in case a callout fails). Then if routing set |
| 1999 | up a list of hosts or the transport has a host list, and the callout option |
| 2000 | is set, and we aren't in a host checking run, do the callout verification, |
| 2001 | and set another flag that notes that a callout happened. */ |
| 2002 | |
| 2003 | if (rc == OK) |
| 2004 | { |
| 2005 | if (routed != NULL) *routed = TRUE; |
| 2006 | if (callout > 0) |
| 2007 | { |
| 2008 | host_item *host_list = addr->host_list; |
| 2009 | transport_instance * tp; |
| 2010 | |
| 2011 | /* Make up some data for use in the case where there is no remote |
| 2012 | transport. */ |
| 2013 | |
| 2014 | transport_feedback tf = { |
| 2015 | NULL, /* interface (=> any) */ |
| 2016 | US"smtp", /* port */ |
| 2017 | US"smtp", /* protocol */ |
| 2018 | NULL, /* hosts */ |
| 2019 | US"$smtp_active_hostname", /* helo_data */ |
| 2020 | FALSE, /* hosts_override */ |
| 2021 | FALSE, /* hosts_randomize */ |
| 2022 | FALSE, /* gethostbyname */ |
| 2023 | TRUE, /* qualify_single */ |
| 2024 | FALSE /* search_parents */ |
| 2025 | }; |
| 2026 | |
| 2027 | /* If verification yielded a remote transport, we want to use that |
| 2028 | transport's options, so as to mimic what would happen if we were really |
| 2029 | sending a message to this address. */ |
| 2030 | |
| 2031 | if ((tp = addr->transport) && !tp->info->local) |
| 2032 | { |
| 2033 | (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL); |
| 2034 | |
| 2035 | /* If the transport has hosts and the router does not, or if the |
| 2036 | transport is configured to override the router's hosts, we must build a |
| 2037 | host list of the transport's hosts, and find the IP addresses */ |
| 2038 | |
| 2039 | if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override)) |
| 2040 | { |
| 2041 | uschar *s; |
| 2042 | const uschar *save_deliver_domain = deliver_domain; |
| 2043 | uschar *save_deliver_localpart = deliver_localpart; |
| 2044 | |
| 2045 | host_list = NULL; /* Ignore the router's hosts */ |
| 2046 | |
| 2047 | deliver_domain = addr->domain; |
| 2048 | deliver_localpart = addr->local_part; |
| 2049 | s = expand_string(tf.hosts); |
| 2050 | deliver_domain = save_deliver_domain; |
| 2051 | deliver_localpart = save_deliver_localpart; |
| 2052 | |
| 2053 | if (s == NULL) |
| 2054 | { |
| 2055 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts " |
| 2056 | "\"%s\" in %s transport for callout: %s", tf.hosts, |
| 2057 | tp->name, expand_string_message); |
| 2058 | } |
| 2059 | else |
| 2060 | { |
| 2061 | int flags; |
| 2062 | host_item *host, *nexthost; |
| 2063 | host_build_hostlist(&host_list, s, tf.hosts_randomize); |
| 2064 | |
| 2065 | /* Just ignore failures to find a host address. If we don't manage |
| 2066 | to find any addresses, the callout will defer. Note that more than |
| 2067 | one address may be found for a single host, which will result in |
| 2068 | additional host items being inserted into the chain. Hence we must |
| 2069 | save the next host first. */ |
| 2070 | |
| 2071 | flags = HOST_FIND_BY_A; |
| 2072 | if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; |
| 2073 | if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS; |
| 2074 | |
| 2075 | for (host = host_list; host != NULL; host = nexthost) |
| 2076 | { |
| 2077 | nexthost = host->next; |
| 2078 | if (tf.gethostbyname || |
| 2079 | string_is_ip_address(host->name, NULL) != 0) |
| 2080 | (void)host_find_byname(host, NULL, flags, NULL, TRUE); |
| 2081 | else |
| 2082 | { |
| 2083 | dnssec_domains * dnssec_domains = NULL; |
| 2084 | if (Ustrcmp(tp->driver_name, "smtp") == 0) |
| 2085 | { |
| 2086 | smtp_transport_options_block * ob = |
| 2087 | (smtp_transport_options_block *) tp->options_block; |
| 2088 | dnssec_domains = &ob->dnssec; |
| 2089 | } |
| 2090 | |
| 2091 | (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL, |
| 2092 | dnssec_domains, NULL, NULL); |
| 2093 | } |
| 2094 | } |
| 2095 | } |
| 2096 | } |
| 2097 | } |
| 2098 | |
| 2099 | /* Can only do a callout if we have at least one host! If the callout |
| 2100 | fails, it will have set ${sender,recipient}_verify_failure. */ |
| 2101 | |
| 2102 | if (host_list != NULL) |
| 2103 | { |
| 2104 | HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n"); |
| 2105 | if (host_checking && !host_checking_callout) |
| 2106 | { |
| 2107 | HDEBUG(D_verify) |
| 2108 | debug_printf("... callout omitted by default when host testing\n" |
| 2109 | "(Use -bhc if you want the callouts to happen.)\n"); |
| 2110 | } |
| 2111 | else |
| 2112 | { |
| 2113 | #ifdef SUPPORT_TLS |
| 2114 | deliver_set_expansions(addr); |
| 2115 | #endif |
| 2116 | verify_mode = is_recipient ? US"R" : US"S"; |
| 2117 | rc = do_callout(addr, host_list, &tf, callout, callout_overall, |
| 2118 | callout_connect, options, se_mailfrom, pm_mailfrom); |
| 2119 | verify_mode = NULL; |
| 2120 | } |
| 2121 | } |
| 2122 | else |
| 2123 | { |
| 2124 | HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor " |
| 2125 | "transport provided a host list\n"); |
| 2126 | } |
| 2127 | } |
| 2128 | } |
| 2129 | |
| 2130 | /* Otherwise, any failure is a routing failure */ |
| 2131 | |
| 2132 | else *failure_ptr = US"route"; |
| 2133 | |
| 2134 | /* A router may return REROUTED if it has set up a child address as a result |
| 2135 | of a change of domain name (typically from widening). In this case we always |
| 2136 | want to continue to verify the new child. */ |
| 2137 | |
| 2138 | if (rc == REROUTED) continue; |
| 2139 | |
| 2140 | /* Handle hard failures */ |
| 2141 | |
| 2142 | if (rc == FAIL) |
| 2143 | { |
| 2144 | allok = FALSE; |
| 2145 | if (f != NULL) |
| 2146 | { |
| 2147 | address_item *p = addr->parent; |
| 2148 | |
| 2149 | respond_printf(f, "%s%s %s", ko_prefix, |
| 2150 | full_info? addr->address : address, |
| 2151 | address_test_mode? "is undeliverable" : "failed to verify"); |
| 2152 | if (!expn && admin_user) |
| 2153 | { |
| 2154 | if (addr->basic_errno > 0) |
| 2155 | respond_printf(f, ": %s", strerror(addr->basic_errno)); |
| 2156 | if (addr->message != NULL) |
| 2157 | respond_printf(f, ": %s", addr->message); |
| 2158 | } |
| 2159 | |
| 2160 | /* Show parents iff doing full info */ |
| 2161 | |
| 2162 | if (full_info) while (p != NULL) |
| 2163 | { |
| 2164 | respond_printf(f, "%s\n <-- %s", cr, p->address); |
| 2165 | p = p->parent; |
| 2166 | } |
| 2167 | respond_printf(f, "%s\n", cr); |
| 2168 | } |
| 2169 | cancel_cutthrough_connection("routing hard fail"); |
| 2170 | |
| 2171 | if (!full_info) |
| 2172 | { |
| 2173 | yield = copy_error(vaddr, addr, FAIL); |
| 2174 | goto out; |
| 2175 | } |
| 2176 | else yield = FAIL; |
| 2177 | } |
| 2178 | |
| 2179 | /* Soft failure */ |
| 2180 | |
| 2181 | else if (rc == DEFER) |
| 2182 | { |
| 2183 | allok = FALSE; |
| 2184 | if (f != NULL) |
| 2185 | { |
| 2186 | address_item *p = addr->parent; |
| 2187 | respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix, |
| 2188 | full_info? addr->address : address); |
| 2189 | if (!expn && admin_user) |
| 2190 | { |
| 2191 | if (addr->basic_errno > 0) |
| 2192 | respond_printf(f, ": %s", strerror(addr->basic_errno)); |
| 2193 | if (addr->message != NULL) |
| 2194 | respond_printf(f, ": %s", addr->message); |
| 2195 | else if (addr->basic_errno <= 0) |
| 2196 | respond_printf(f, ": unknown error"); |
| 2197 | } |
| 2198 | |
| 2199 | /* Show parents iff doing full info */ |
| 2200 | |
| 2201 | if (full_info) while (p != NULL) |
| 2202 | { |
| 2203 | respond_printf(f, "%s\n <-- %s", cr, p->address); |
| 2204 | p = p->parent; |
| 2205 | } |
| 2206 | respond_printf(f, "%s\n", cr); |
| 2207 | } |
| 2208 | cancel_cutthrough_connection("routing soft fail"); |
| 2209 | |
| 2210 | if (!full_info) |
| 2211 | { |
| 2212 | yield = copy_error(vaddr, addr, DEFER); |
| 2213 | goto out; |
| 2214 | } |
| 2215 | else if (yield == OK) yield = DEFER; |
| 2216 | } |
| 2217 | |
| 2218 | /* If we are handling EXPN, we do not want to continue to route beyond |
| 2219 | the top level (whose address is in "address"). */ |
| 2220 | |
| 2221 | else if (expn) |
| 2222 | { |
| 2223 | uschar *ok_prefix = US"250-"; |
| 2224 | if (addr_new == NULL) |
| 2225 | { |
| 2226 | if (addr_local == NULL && addr_remote == NULL) |
| 2227 | respond_printf(f, "250 mail to <%s> is discarded\r\n", address); |
| 2228 | else |
| 2229 | respond_printf(f, "250 <%s>\r\n", address); |
| 2230 | } |
| 2231 | else while (addr_new != NULL) |
| 2232 | { |
| 2233 | address_item *addr2 = addr_new; |
| 2234 | addr_new = addr2->next; |
| 2235 | if (addr_new == NULL) ok_prefix = US"250 "; |
| 2236 | respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address); |
| 2237 | } |
| 2238 | yield = OK; |
| 2239 | goto out; |
| 2240 | } |
| 2241 | |
| 2242 | /* Successful routing other than EXPN. */ |
| 2243 | |
| 2244 | else |
| 2245 | { |
| 2246 | /* Handle successful routing when short info wanted. Otherwise continue for |
| 2247 | other (generated) addresses. Short info is the operational case. Full info |
| 2248 | can be requested only when debug_selector != 0 and a file is supplied. |
| 2249 | |
| 2250 | There is a conflict between the use of aliasing as an alternate email |
| 2251 | address, and as a sort of mailing list. If an alias turns the incoming |
| 2252 | address into just one address (e.g. J.Caesar->jc44) you may well want to |
| 2253 | carry on verifying the generated address to ensure it is valid when |
| 2254 | checking incoming mail. If aliasing generates multiple addresses, you |
| 2255 | probably don't want to do this. Exim therefore treats the generation of |
| 2256 | just a single new address as a special case, and continues on to verify the |
| 2257 | generated address. */ |
| 2258 | |
| 2259 | if (!full_info && /* Stop if short info wanted AND */ |
| 2260 | (((addr_new == NULL || /* No new address OR */ |
| 2261 | addr_new->next != NULL || /* More than one new address OR */ |
| 2262 | testflag(addr_new, af_pfr))) /* New address is pfr */ |
| 2263 | || /* OR */ |
| 2264 | (addr_new != NULL && /* At least one new address AND */ |
| 2265 | success_on_redirect))) /* success_on_redirect is set */ |
| 2266 | { |
| 2267 | if (f != NULL) fprintf(f, "%s %s\n", address, |
| 2268 | address_test_mode? "is deliverable" : "verified"); |
| 2269 | |
| 2270 | /* If we have carried on to verify a child address, we want the value |
| 2271 | of $address_data to be that of the child */ |
| 2272 | |
| 2273 | vaddr->prop.address_data = addr->prop.address_data; |
| 2274 | yield = OK; |
| 2275 | goto out; |
| 2276 | } |
| 2277 | } |
| 2278 | } /* Loop for generated addresses */ |
| 2279 | |
| 2280 | /* Display the full results of the successful routing, including any generated |
| 2281 | addresses. Control gets here only when full_info is set, which requires f not |
| 2282 | to be NULL, and this occurs only when a top-level verify is called with the |
| 2283 | debugging switch on. |
| 2284 | |
| 2285 | If there are no local and no remote addresses, and there were no pipes, files, |
| 2286 | or autoreplies, and there were no errors or deferments, the message is to be |
| 2287 | discarded, usually because of the use of :blackhole: in an alias file. */ |
| 2288 | |
| 2289 | if (allok && addr_local == NULL && addr_remote == NULL) |
| 2290 | { |
| 2291 | fprintf(f, "mail to %s is discarded\n", address); |
| 2292 | goto out; |
| 2293 | } |
| 2294 | |
| 2295 | for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++) |
| 2296 | while (addr_list) |
| 2297 | { |
| 2298 | address_item *addr = addr_list; |
| 2299 | address_item *p = addr->parent; |
| 2300 | transport_instance * tp = addr->transport; |
| 2301 | |
| 2302 | addr_list = addr->next; |
| 2303 | |
| 2304 | fprintf(f, "%s", CS addr->address); |
| 2305 | #ifdef EXPERIMENTAL_SRS |
| 2306 | if(addr->prop.srs_sender) |
| 2307 | fprintf(f, " [srs = %s]", addr->prop.srs_sender); |
| 2308 | #endif |
| 2309 | |
| 2310 | /* If the address is a duplicate, show something about it. */ |
| 2311 | |
| 2312 | if (!testflag(addr, af_pfr)) |
| 2313 | { |
| 2314 | tree_node *tnode; |
| 2315 | if ((tnode = tree_search(tree_duplicates, addr->unique))) |
| 2316 | fprintf(f, " [duplicate, would not be delivered]"); |
| 2317 | else tree_add_duplicate(addr->unique, addr); |
| 2318 | } |
| 2319 | |
| 2320 | /* Now show its parents */ |
| 2321 | |
| 2322 | for (p = addr->parent; p; p = p->parent) |
| 2323 | fprintf(f, "\n <-- %s", p->address); |
| 2324 | fprintf(f, "\n "); |
| 2325 | |
| 2326 | /* Show router, and transport */ |
| 2327 | |
| 2328 | fprintf(f, "router = %s, transport = %s\n", |
| 2329 | addr->router->name, tp ? tp->name : US"unset"); |
| 2330 | |
| 2331 | /* Show any hosts that are set up by a router unless the transport |
| 2332 | is going to override them; fiddle a bit to get a nice format. */ |
| 2333 | |
| 2334 | if (addr->host_list && tp && !tp->overrides_hosts) |
| 2335 | { |
| 2336 | host_item *h; |
| 2337 | int maxlen = 0; |
| 2338 | int maxaddlen = 0; |
| 2339 | for (h = addr->host_list; h; h = h->next) |
| 2340 | { /* get max lengths of host names, addrs */ |
| 2341 | int len = Ustrlen(h->name); |
| 2342 | if (len > maxlen) maxlen = len; |
| 2343 | len = h->address ? Ustrlen(h->address) : 7; |
| 2344 | if (len > maxaddlen) maxaddlen = len; |
| 2345 | } |
| 2346 | for (h = addr->host_list; h; h = h->next) |
| 2347 | { |
| 2348 | fprintf(f, " host %-*s ", maxlen, h->name); |
| 2349 | |
| 2350 | if (h->address) |
| 2351 | fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']'); |
| 2352 | else if (tp->info->local) |
| 2353 | fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */ |
| 2354 | else |
| 2355 | fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']'); |
| 2356 | |
| 2357 | if (h->mx >= 0) fprintf(f, " MX=%d", h->mx); |
| 2358 | if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port); |
| 2359 | if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f); |
| 2360 | if (h->status == hstatus_unusable) fputs(" ** unusable **", f); |
| 2361 | fputc('\n', f); |
| 2362 | } |
| 2363 | } |
| 2364 | } |
| 2365 | |
| 2366 | /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is |
| 2367 | the -bv or -bt case). */ |
| 2368 | |
| 2369 | out: |
| 2370 | tls_modify_variables(&tls_in); |
| 2371 | |
| 2372 | return yield; |
| 2373 | } |
| 2374 | |
| 2375 | |
| 2376 | |
| 2377 | |
| 2378 | /************************************************* |
| 2379 | * Check headers for syntax errors * |
| 2380 | *************************************************/ |
| 2381 | |
| 2382 | /* This function checks those header lines that contain addresses, and verifies |
| 2383 | that all the addresses therein are syntactially correct. |
| 2384 | |
| 2385 | Arguments: |
| 2386 | msgptr where to put an error message |
| 2387 | |
| 2388 | Returns: OK |
| 2389 | FAIL |
| 2390 | */ |
| 2391 | |
| 2392 | int |
| 2393 | verify_check_headers(uschar **msgptr) |
| 2394 | { |
| 2395 | header_line *h; |
| 2396 | uschar *colon, *s; |
| 2397 | int yield = OK; |
| 2398 | |
| 2399 | for (h = header_list; h != NULL && yield == OK; h = h->next) |
| 2400 | { |
| 2401 | if (h->type != htype_from && |
| 2402 | h->type != htype_reply_to && |
| 2403 | h->type != htype_sender && |
| 2404 | h->type != htype_to && |
| 2405 | h->type != htype_cc && |
| 2406 | h->type != htype_bcc) |
| 2407 | continue; |
| 2408 | |
| 2409 | colon = Ustrchr(h->text, ':'); |
| 2410 | s = colon + 1; |
| 2411 | while (isspace(*s)) s++; |
| 2412 | |
| 2413 | /* Loop for multiple addresses in the header, enabling group syntax. Note |
| 2414 | that we have to reset this after the header has been scanned. */ |
| 2415 | |
| 2416 | parse_allow_group = TRUE; |
| 2417 | |
| 2418 | while (*s != 0) |
| 2419 | { |
| 2420 | uschar *ss = parse_find_address_end(s, FALSE); |
| 2421 | uschar *recipient, *errmess; |
| 2422 | int terminator = *ss; |
| 2423 | int start, end, domain; |
| 2424 | |
| 2425 | /* Temporarily terminate the string at this point, and extract the |
| 2426 | operative address within, allowing group syntax. */ |
| 2427 | |
| 2428 | *ss = 0; |
| 2429 | recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); |
| 2430 | *ss = terminator; |
| 2431 | |
| 2432 | /* Permit an unqualified address only if the message is local, or if the |
| 2433 | sending host is configured to be permitted to send them. */ |
| 2434 | |
| 2435 | if (recipient != NULL && domain == 0) |
| 2436 | { |
| 2437 | if (h->type == htype_from || h->type == htype_sender) |
| 2438 | { |
| 2439 | if (!allow_unqualified_sender) recipient = NULL; |
| 2440 | } |
| 2441 | else |
| 2442 | { |
| 2443 | if (!allow_unqualified_recipient) recipient = NULL; |
| 2444 | } |
| 2445 | if (recipient == NULL) errmess = US"unqualified address not permitted"; |
| 2446 | } |
| 2447 | |
| 2448 | /* It's an error if no address could be extracted, except for the special |
| 2449 | case of an empty address. */ |
| 2450 | |
| 2451 | if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0) |
| 2452 | { |
| 2453 | uschar *verb = US"is"; |
| 2454 | uschar *t = ss; |
| 2455 | uschar *tt = colon; |
| 2456 | int len; |
| 2457 | |
| 2458 | /* Arrange not to include any white space at the end in the |
| 2459 | error message or the header name. */ |
| 2460 | |
| 2461 | while (t > s && isspace(t[-1])) t--; |
| 2462 | while (tt > h->text && isspace(tt[-1])) tt--; |
| 2463 | |
| 2464 | /* Add the address that failed to the error message, since in a |
| 2465 | header with very many addresses it is sometimes hard to spot |
| 2466 | which one is at fault. However, limit the amount of address to |
| 2467 | quote - cases have been seen where, for example, a missing double |
| 2468 | quote in a humungous To: header creates an "address" that is longer |
| 2469 | than string_sprintf can handle. */ |
| 2470 | |
| 2471 | len = t - s; |
| 2472 | if (len > 1024) |
| 2473 | { |
| 2474 | len = 1024; |
| 2475 | verb = US"begins"; |
| 2476 | } |
| 2477 | |
| 2478 | /* deconst cast ok as we're passing a non-const to string_printing() */ |
| 2479 | *msgptr = US string_printing( |
| 2480 | string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s", |
| 2481 | errmess, tt - h->text, h->text, verb, len, s)); |
| 2482 | |
| 2483 | yield = FAIL; |
| 2484 | break; /* Out of address loop */ |
| 2485 | } |
| 2486 | |
| 2487 | /* Advance to the next address */ |
| 2488 | |
| 2489 | s = ss + (terminator? 1:0); |
| 2490 | while (isspace(*s)) s++; |
| 2491 | } /* Next address */ |
| 2492 | |
| 2493 | parse_allow_group = FALSE; |
| 2494 | parse_found_group = FALSE; |
| 2495 | } /* Next header unless yield has been set FALSE */ |
| 2496 | |
| 2497 | return yield; |
| 2498 | } |
| 2499 | |
| 2500 | |
| 2501 | /************************************************* |
| 2502 | * Check header names for 8-bit characters * |
| 2503 | *************************************************/ |
| 2504 | |
| 2505 | /* This function checks for invalid charcters in header names. See |
| 2506 | RFC 5322, 2.2. and RFC 6532, 3. |
| 2507 | |
| 2508 | Arguments: |
| 2509 | msgptr where to put an error message |
| 2510 | |
| 2511 | Returns: OK |
| 2512 | FAIL |
| 2513 | */ |
| 2514 | |
| 2515 | int |
| 2516 | verify_check_header_names_ascii(uschar **msgptr) |
| 2517 | { |
| 2518 | header_line *h; |
| 2519 | uschar *colon, *s; |
| 2520 | |
| 2521 | for (h = header_list; h != NULL; h = h->next) |
| 2522 | { |
| 2523 | colon = Ustrchr(h->text, ':'); |
| 2524 | for(s = h->text; s < colon; s++) |
| 2525 | { |
| 2526 | if ((*s < 33) || (*s > 126)) |
| 2527 | { |
| 2528 | *msgptr = string_sprintf("Invalid character in header \"%.*s\" found", |
| 2529 | colon - h->text, h->text); |
| 2530 | return FAIL; |
| 2531 | } |
| 2532 | } |
| 2533 | } |
| 2534 | return OK; |
| 2535 | } |
| 2536 | |
| 2537 | /************************************************* |
| 2538 | * Check for blind recipients * |
| 2539 | *************************************************/ |
| 2540 | |
| 2541 | /* This function checks that every (envelope) recipient is mentioned in either |
| 2542 | the To: or Cc: header lines, thus detecting blind carbon copies. |
| 2543 | |
| 2544 | There are two ways of scanning that could be used: either scan the header lines |
| 2545 | and tick off the recipients, or scan the recipients and check the header lines. |
| 2546 | The original proposed patch did the former, but I have chosen to do the latter, |
| 2547 | because (a) it requires no memory and (b) will use fewer resources when there |
| 2548 | are many addresses in To: and/or Cc: and only one or two envelope recipients. |
| 2549 | |
| 2550 | Arguments: none |
| 2551 | Returns: OK if there are no blind recipients |
| 2552 | FAIL if there is at least one blind recipient |
| 2553 | */ |
| 2554 | |
| 2555 | int |
| 2556 | verify_check_notblind(void) |
| 2557 | { |
| 2558 | int i; |
| 2559 | for (i = 0; i < recipients_count; i++) |
| 2560 | { |
| 2561 | header_line *h; |
| 2562 | BOOL found = FALSE; |
| 2563 | uschar *address = recipients_list[i].address; |
| 2564 | |
| 2565 | for (h = header_list; !found && h != NULL; h = h->next) |
| 2566 | { |
| 2567 | uschar *colon, *s; |
| 2568 | |
| 2569 | if (h->type != htype_to && h->type != htype_cc) continue; |
| 2570 | |
| 2571 | colon = Ustrchr(h->text, ':'); |
| 2572 | s = colon + 1; |
| 2573 | while (isspace(*s)) s++; |
| 2574 | |
| 2575 | /* Loop for multiple addresses in the header, enabling group syntax. Note |
| 2576 | that we have to reset this after the header has been scanned. */ |
| 2577 | |
| 2578 | parse_allow_group = TRUE; |
| 2579 | |
| 2580 | while (*s != 0) |
| 2581 | { |
| 2582 | uschar *ss = parse_find_address_end(s, FALSE); |
| 2583 | uschar *recipient,*errmess; |
| 2584 | int terminator = *ss; |
| 2585 | int start, end, domain; |
| 2586 | |
| 2587 | /* Temporarily terminate the string at this point, and extract the |
| 2588 | operative address within, allowing group syntax. */ |
| 2589 | |
| 2590 | *ss = 0; |
| 2591 | recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); |
| 2592 | *ss = terminator; |
| 2593 | |
| 2594 | /* If we found a valid recipient that has a domain, compare it with the |
| 2595 | envelope recipient. Local parts are compared case-sensitively, domains |
| 2596 | case-insensitively. By comparing from the start with length "domain", we |
| 2597 | include the "@" at the end, which ensures that we are comparing the whole |
| 2598 | local part of each address. */ |
| 2599 | |
| 2600 | if (recipient != NULL && domain != 0) |
| 2601 | { |
| 2602 | found = Ustrncmp(recipient, address, domain) == 0 && |
| 2603 | strcmpic(recipient + domain, address + domain) == 0; |
| 2604 | if (found) break; |
| 2605 | } |
| 2606 | |
| 2607 | /* Advance to the next address */ |
| 2608 | |
| 2609 | s = ss + (terminator? 1:0); |
| 2610 | while (isspace(*s)) s++; |
| 2611 | } /* Next address */ |
| 2612 | |
| 2613 | parse_allow_group = FALSE; |
| 2614 | parse_found_group = FALSE; |
| 2615 | } /* Next header (if found is false) */ |
| 2616 | |
| 2617 | if (!found) return FAIL; |
| 2618 | } /* Next recipient */ |
| 2619 | |
| 2620 | return OK; |
| 2621 | } |
| 2622 | |
| 2623 | |
| 2624 | |
| 2625 | /************************************************* |
| 2626 | * Find if verified sender * |
| 2627 | *************************************************/ |
| 2628 | |
| 2629 | /* Usually, just a single address is verified as the sender of the message. |
| 2630 | However, Exim can be made to verify other addresses as well (often related in |
| 2631 | some way), and this is useful in some environments. There may therefore be a |
| 2632 | chain of such addresses that have previously been tested. This function finds |
| 2633 | whether a given address is on the chain. |
| 2634 | |
| 2635 | Arguments: the address to be verified |
| 2636 | Returns: pointer to an address item, or NULL |
| 2637 | */ |
| 2638 | |
| 2639 | address_item * |
| 2640 | verify_checked_sender(uschar *sender) |
| 2641 | { |
| 2642 | address_item *addr; |
| 2643 | for (addr = sender_verified_list; addr != NULL; addr = addr->next) |
| 2644 | if (Ustrcmp(sender, addr->address) == 0) break; |
| 2645 | return addr; |
| 2646 | } |
| 2647 | |
| 2648 | |
| 2649 | |
| 2650 | |
| 2651 | |
| 2652 | /************************************************* |
| 2653 | * Get valid header address * |
| 2654 | *************************************************/ |
| 2655 | |
| 2656 | /* Scan the originator headers of the message, looking for an address that |
| 2657 | verifies successfully. RFC 822 says: |
| 2658 | |
| 2659 | o The "Sender" field mailbox should be sent notices of |
| 2660 | any problems in transport or delivery of the original |
| 2661 | messages. If there is no "Sender" field, then the |
| 2662 | "From" field mailbox should be used. |
| 2663 | |
| 2664 | o If the "Reply-To" field exists, then the reply should |
| 2665 | go to the addresses indicated in that field and not to |
| 2666 | the address(es) indicated in the "From" field. |
| 2667 | |
| 2668 | So we check a Sender field if there is one, else a Reply_to field, else a From |
| 2669 | field. As some strange messages may have more than one of these fields, |
| 2670 | especially if they are resent- fields, check all of them if there is more than |
| 2671 | one. |
| 2672 | |
| 2673 | Arguments: |
| 2674 | user_msgptr points to where to put a user error message |
| 2675 | log_msgptr points to where to put a log error message |
| 2676 | callout timeout for callout check (passed to verify_address()) |
| 2677 | callout_overall overall callout timeout (ditto) |
| 2678 | callout_connect connect callout timeout (ditto) |
| 2679 | se_mailfrom mailfrom for verify; NULL => "" |
| 2680 | pm_mailfrom sender for pm callout check (passed to verify_address()) |
| 2681 | options callout options (passed to verify_address()) |
| 2682 | verrno where to put the address basic_errno |
| 2683 | |
| 2684 | If log_msgptr is set to something without setting user_msgptr, the caller |
| 2685 | normally uses log_msgptr for both things. |
| 2686 | |
| 2687 | Returns: result of the verification attempt: OK, FAIL, or DEFER; |
| 2688 | FAIL is given if no appropriate headers are found |
| 2689 | */ |
| 2690 | |
| 2691 | int |
| 2692 | verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr, |
| 2693 | int callout, int callout_overall, int callout_connect, uschar *se_mailfrom, |
| 2694 | uschar *pm_mailfrom, int options, int *verrno) |
| 2695 | { |
| 2696 | static int header_types[] = { htype_sender, htype_reply_to, htype_from }; |
| 2697 | BOOL done = FALSE; |
| 2698 | int yield = FAIL; |
| 2699 | int i; |
| 2700 | |
| 2701 | for (i = 0; i < 3 && !done; i++) |
| 2702 | { |
| 2703 | header_line *h; |
| 2704 | for (h = header_list; h != NULL && !done; h = h->next) |
| 2705 | { |
| 2706 | int terminator, new_ok; |
| 2707 | uschar *s, *ss, *endname; |
| 2708 | |
| 2709 | if (h->type != header_types[i]) continue; |
| 2710 | s = endname = Ustrchr(h->text, ':') + 1; |
| 2711 | |
| 2712 | /* Scan the addresses in the header, enabling group syntax. Note that we |
| 2713 | have to reset this after the header has been scanned. */ |
| 2714 | |
| 2715 | parse_allow_group = TRUE; |
| 2716 | |
| 2717 | while (*s != 0) |
| 2718 | { |
| 2719 | address_item *vaddr; |
| 2720 | |
| 2721 | while (isspace(*s) || *s == ',') s++; |
| 2722 | if (*s == 0) break; /* End of header */ |
| 2723 | |
| 2724 | ss = parse_find_address_end(s, FALSE); |
| 2725 | |
| 2726 | /* The terminator is a comma or end of header, but there may be white |
| 2727 | space preceding it (including newline for the last address). Move back |
| 2728 | past any white space so we can check against any cached envelope sender |
| 2729 | address verifications. */ |
| 2730 | |
| 2731 | while (isspace(ss[-1])) ss--; |
| 2732 | terminator = *ss; |
| 2733 | *ss = 0; |
| 2734 | |
| 2735 | HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n", |
| 2736 | (int)(endname - h->text), h->text, s); |
| 2737 | |
| 2738 | /* See if we have already verified this address as an envelope sender, |
| 2739 | and if so, use the previous answer. */ |
| 2740 | |
| 2741 | vaddr = verify_checked_sender(s); |
| 2742 | |
| 2743 | if (vaddr != NULL && /* Previously checked */ |
| 2744 | (callout <= 0 || /* No callout needed; OR */ |
| 2745 | vaddr->special_action > 256)) /* Callout was done */ |
| 2746 | { |
| 2747 | new_ok = vaddr->special_action & 255; |
| 2748 | HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n"); |
| 2749 | *ss = terminator; /* Restore shortened string */ |
| 2750 | } |
| 2751 | |
| 2752 | /* Otherwise we run the verification now. We must restore the shortened |
| 2753 | string before running the verification, so the headers are correct, in |
| 2754 | case there is any rewriting. */ |
| 2755 | |
| 2756 | else |
| 2757 | { |
| 2758 | int start, end, domain; |
| 2759 | uschar *address = parse_extract_address(s, log_msgptr, &start, &end, |
| 2760 | &domain, FALSE); |
| 2761 | |
| 2762 | *ss = terminator; |
| 2763 | |
| 2764 | /* If we found an empty address, just carry on with the next one, but |
| 2765 | kill the message. */ |
| 2766 | |
| 2767 | if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0) |
| 2768 | { |
| 2769 | *log_msgptr = NULL; |
| 2770 | s = ss; |
| 2771 | continue; |
| 2772 | } |
| 2773 | |
| 2774 | /* If verification failed because of a syntax error, fail this |
| 2775 | function, and ensure that the failing address gets added to the error |
| 2776 | message. */ |
| 2777 | |
| 2778 | if (address == NULL) |
| 2779 | { |
| 2780 | new_ok = FAIL; |
| 2781 | while (ss > s && isspace(ss[-1])) ss--; |
| 2782 | *log_msgptr = string_sprintf("syntax error in '%.*s' header when " |
| 2783 | "scanning for sender: %s in \"%.*s\"", |
| 2784 | endname - h->text, h->text, *log_msgptr, ss - s, s); |
| 2785 | yield = FAIL; |
| 2786 | done = TRUE; |
| 2787 | break; |
| 2788 | } |
| 2789 | |
| 2790 | /* Else go ahead with the sender verification. But it isn't *the* |
| 2791 | sender of the message, so set vopt_fake_sender to stop sender_address |
| 2792 | being replaced after rewriting or qualification. */ |
| 2793 | |
| 2794 | else |
| 2795 | { |
| 2796 | vaddr = deliver_make_addr(address, FALSE); |
| 2797 | new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender, |
| 2798 | callout, callout_overall, callout_connect, se_mailfrom, |
| 2799 | pm_mailfrom, NULL); |
| 2800 | } |
| 2801 | } |
| 2802 | |
| 2803 | /* We now have the result, either newly found, or cached. If we are |
| 2804 | giving out error details, set a specific user error. This means that the |
| 2805 | last of these will be returned to the user if all three fail. We do not |
| 2806 | set a log message - the generic one below will be used. */ |
| 2807 | |
| 2808 | if (new_ok != OK) |
| 2809 | { |
| 2810 | *verrno = vaddr->basic_errno; |
| 2811 | if (smtp_return_error_details) |
| 2812 | { |
| 2813 | *user_msgptr = string_sprintf("Rejected after DATA: " |
| 2814 | "could not verify \"%.*s\" header address\n%s: %s", |
| 2815 | endname - h->text, h->text, vaddr->address, vaddr->message); |
| 2816 | } |
| 2817 | } |
| 2818 | |
| 2819 | /* Success or defer */ |
| 2820 | |
| 2821 | if (new_ok == OK) |
| 2822 | { |
| 2823 | yield = OK; |
| 2824 | done = TRUE; |
| 2825 | break; |
| 2826 | } |
| 2827 | |
| 2828 | if (new_ok == DEFER) yield = DEFER; |
| 2829 | |
| 2830 | /* Move on to any more addresses in the header */ |
| 2831 | |
| 2832 | s = ss; |
| 2833 | } /* Next address */ |
| 2834 | |
| 2835 | parse_allow_group = FALSE; |
| 2836 | parse_found_group = FALSE; |
| 2837 | } /* Next header, unless done */ |
| 2838 | } /* Next header type unless done */ |
| 2839 | |
| 2840 | if (yield == FAIL && *log_msgptr == NULL) |
| 2841 | *log_msgptr = US"there is no valid sender in any header line"; |
| 2842 | |
| 2843 | if (yield == DEFER && *log_msgptr == NULL) |
| 2844 | *log_msgptr = US"all attempts to verify a sender in a header line deferred"; |
| 2845 | |
| 2846 | return yield; |
| 2847 | } |
| 2848 | |
| 2849 | |
| 2850 | |
| 2851 | |
| 2852 | /************************************************* |
| 2853 | * Get RFC 1413 identification * |
| 2854 | *************************************************/ |
| 2855 | |
| 2856 | /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If |
| 2857 | the timeout is set to zero, then the query is not done. There may also be lists |
| 2858 | of hosts and nets which are exempt. To guard against malefactors sending |
| 2859 | non-printing characters which could, for example, disrupt a message's headers, |
| 2860 | make sure the string consists of printing characters only. |
| 2861 | |
| 2862 | Argument: |
| 2863 | port the port to connect to; usually this is IDENT_PORT (113), but when |
| 2864 | running in the test harness with -bh a different value is used. |
| 2865 | |
| 2866 | Returns: nothing |
| 2867 | |
| 2868 | Side effect: any received ident value is put in sender_ident (NULL otherwise) |
| 2869 | */ |
| 2870 | |
| 2871 | void |
| 2872 | verify_get_ident(int port) |
| 2873 | { |
| 2874 | int sock, host_af, qlen; |
| 2875 | int received_sender_port, received_interface_port, n; |
| 2876 | uschar *p; |
| 2877 | uschar buffer[2048]; |
| 2878 | |
| 2879 | /* Default is no ident. Check whether we want to do an ident check for this |
| 2880 | host. */ |
| 2881 | |
| 2882 | sender_ident = NULL; |
| 2883 | if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK) |
| 2884 | return; |
| 2885 | |
| 2886 | DEBUG(D_ident) debug_printf("doing ident callback\n"); |
| 2887 | |
| 2888 | /* Set up a connection to the ident port of the remote host. Bind the local end |
| 2889 | to the incoming interface address. If the sender host address is an IPv6 |
| 2890 | address, the incoming interface address will also be IPv6. */ |
| 2891 | |
| 2892 | host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6; |
| 2893 | sock = ip_socket(SOCK_STREAM, host_af); |
| 2894 | if (sock < 0) return; |
| 2895 | |
| 2896 | if (ip_bind(sock, host_af, interface_address, 0) < 0) |
| 2897 | { |
| 2898 | DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n", |
| 2899 | strerror(errno)); |
| 2900 | goto END_OFF; |
| 2901 | } |
| 2902 | |
| 2903 | if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout) |
| 2904 | < 0) |
| 2905 | { |
| 2906 | if (errno == ETIMEDOUT && LOGGING(ident_timeout)) |
| 2907 | { |
| 2908 | log_write(0, LOG_MAIN, "ident connection to %s timed out", |
| 2909 | sender_host_address); |
| 2910 | } |
| 2911 | else |
| 2912 | { |
| 2913 | DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n", |
| 2914 | sender_host_address, strerror(errno)); |
| 2915 | } |
| 2916 | goto END_OFF; |
| 2917 | } |
| 2918 | |
| 2919 | /* Construct and send the query. */ |
| 2920 | |
| 2921 | sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port); |
| 2922 | qlen = Ustrlen(buffer); |
| 2923 | if (send(sock, buffer, qlen, 0) < 0) |
| 2924 | { |
| 2925 | DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno)); |
| 2926 | goto END_OFF; |
| 2927 | } |
| 2928 | |
| 2929 | /* Read a response line. We put it into the rest of the buffer, using several |
| 2930 | recv() calls if necessary. */ |
| 2931 | |
| 2932 | p = buffer + qlen; |
| 2933 | |
| 2934 | for (;;) |
| 2935 | { |
| 2936 | uschar *pp; |
| 2937 | int count; |
| 2938 | int size = sizeof(buffer) - (p - buffer); |
| 2939 | |
| 2940 | if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */ |
| 2941 | count = ip_recv(sock, p, size, rfc1413_query_timeout); |
| 2942 | if (count <= 0) goto END_OFF; /* Read error or EOF */ |
| 2943 | |
| 2944 | /* Scan what we just read, to see if we have reached the terminating \r\n. Be |
| 2945 | generous, and accept a plain \n terminator as well. The only illegal |
| 2946 | character is 0. */ |
| 2947 | |
| 2948 | for (pp = p; pp < p + count; pp++) |
| 2949 | { |
| 2950 | if (*pp == 0) goto END_OFF; /* Zero octet not allowed */ |
| 2951 | if (*pp == '\n') |
| 2952 | { |
| 2953 | if (pp[-1] == '\r') pp--; |
| 2954 | *pp = 0; |
| 2955 | goto GOT_DATA; /* Break out of both loops */ |
| 2956 | } |
| 2957 | } |
| 2958 | |
| 2959 | /* Reached the end of the data without finding \n. Let the loop continue to |
| 2960 | read some more, if there is room. */ |
| 2961 | |
| 2962 | p = pp; |
| 2963 | } |
| 2964 | |
| 2965 | GOT_DATA: |
| 2966 | |
| 2967 | /* We have received a line of data. Check it carefully. It must start with the |
| 2968 | same two port numbers that we sent, followed by data as defined by the RFC. For |
| 2969 | example, |
| 2970 | |
| 2971 | 12345 , 25 : USERID : UNIX :root |
| 2972 | |
| 2973 | However, the amount of white space may be different to what we sent. In the |
| 2974 | "osname" field there may be several sub-fields, comma separated. The data we |
| 2975 | actually want to save follows the third colon. Some systems put leading spaces |
| 2976 | in it - we discard those. */ |
| 2977 | |
| 2978 | if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port, |
| 2979 | &received_interface_port, &n) != 2 || |
| 2980 | received_sender_port != sender_host_port || |
| 2981 | received_interface_port != interface_port) |
| 2982 | goto END_OFF; |
| 2983 | |
| 2984 | p = buffer + qlen + n; |
| 2985 | while(isspace(*p)) p++; |
| 2986 | if (*p++ != ':') goto END_OFF; |
| 2987 | while(isspace(*p)) p++; |
| 2988 | if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF; |
| 2989 | p += 6; |
| 2990 | while(isspace(*p)) p++; |
| 2991 | if (*p++ != ':') goto END_OFF; |
| 2992 | while (*p != 0 && *p != ':') p++; |
| 2993 | if (*p++ == 0) goto END_OFF; |
| 2994 | while(isspace(*p)) p++; |
| 2995 | if (*p == 0) goto END_OFF; |
| 2996 | |
| 2997 | /* The rest of the line is the data we want. We turn it into printing |
| 2998 | characters when we save it, so that it cannot mess up the format of any logging |
| 2999 | or Received: lines into which it gets inserted. We keep a maximum of 127 |
| 3000 | characters. The deconst cast is ok as we fed a nonconst to string_printing() */ |
| 3001 | |
| 3002 | sender_ident = US string_printing(string_copyn(p, 127)); |
| 3003 | DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident); |
| 3004 | |
| 3005 | END_OFF: |
| 3006 | (void)close(sock); |
| 3007 | return; |
| 3008 | } |
| 3009 | |
| 3010 | |
| 3011 | |
| 3012 | |
| 3013 | /************************************************* |
| 3014 | * Match host to a single host-list item * |
| 3015 | *************************************************/ |
| 3016 | |
| 3017 | /* This function compares a host (name or address) against a single item |
| 3018 | from a host list. The host name gets looked up if it is needed and is not |
| 3019 | already known. The function is called from verify_check_this_host() via |
| 3020 | match_check_list(), which is why most of its arguments are in a single block. |
| 3021 | |
| 3022 | Arguments: |
| 3023 | arg the argument block (see below) |
| 3024 | ss the host-list item |
| 3025 | valueptr where to pass back looked up data, or NULL |
| 3026 | error for error message when returning ERROR |
| 3027 | |
| 3028 | The block contains: |
| 3029 | host_name (a) the host name, or |
| 3030 | (b) NULL, implying use sender_host_name and |
| 3031 | sender_host_aliases, looking them up if required, or |
| 3032 | (c) the empty string, meaning that only IP address matches |
| 3033 | are permitted |
| 3034 | host_address the host address |
| 3035 | host_ipv4 the IPv4 address taken from an IPv6 one |
| 3036 | |
| 3037 | Returns: OK matched |
| 3038 | FAIL did not match |
| 3039 | DEFER lookup deferred |
| 3040 | ERROR (a) failed to find the host name or IP address, or |
| 3041 | (b) unknown lookup type specified, or |
| 3042 | (c) host name encountered when only IP addresses are |
| 3043 | being matched |
| 3044 | */ |
| 3045 | |
| 3046 | int |
| 3047 | check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error) |
| 3048 | { |
| 3049 | check_host_block *cb = (check_host_block *)arg; |
| 3050 | int mlen = -1; |
| 3051 | int maskoffset; |
| 3052 | BOOL iplookup = FALSE; |
| 3053 | BOOL isquery = FALSE; |
| 3054 | BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0; |
| 3055 | const uschar *t; |
| 3056 | uschar *semicolon; |
| 3057 | uschar **aliases; |
| 3058 | |
| 3059 | /* Optimize for the special case when the pattern is "*". */ |
| 3060 | |
| 3061 | if (*ss == '*' && ss[1] == 0) return OK; |
| 3062 | |
| 3063 | /* If the pattern is empty, it matches only in the case when there is no host - |
| 3064 | this can occur in ACL checking for SMTP input using the -bs option. In this |
| 3065 | situation, the host address is the empty string. */ |
| 3066 | |
| 3067 | if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL; |
| 3068 | if (*ss == 0) return FAIL; |
| 3069 | |
| 3070 | /* If the pattern is precisely "@" then match against the primary host name, |
| 3071 | provided that host name matching is permitted; if it's "@[]" match against the |
| 3072 | local host's IP addresses. */ |
| 3073 | |
| 3074 | if (*ss == '@') |
| 3075 | { |
| 3076 | if (ss[1] == 0) |
| 3077 | { |
| 3078 | if (isiponly) return ERROR; |
| 3079 | ss = primary_hostname; |
| 3080 | } |
| 3081 | else if (Ustrcmp(ss, "@[]") == 0) |
| 3082 | { |
| 3083 | ip_address_item *ip; |
| 3084 | for (ip = host_find_interfaces(); ip != NULL; ip = ip->next) |
| 3085 | if (Ustrcmp(ip->address, cb->host_address) == 0) return OK; |
| 3086 | return FAIL; |
| 3087 | } |
| 3088 | } |
| 3089 | |
| 3090 | /* If the pattern is an IP address, optionally followed by a bitmask count, do |
| 3091 | a (possibly masked) comparision with the current IP address. */ |
| 3092 | |
| 3093 | if (string_is_ip_address(ss, &maskoffset) != 0) |
| 3094 | return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL); |
| 3095 | |
| 3096 | /* The pattern is not an IP address. A common error that people make is to omit |
| 3097 | one component of an IPv4 address, either by accident, or believing that, for |
| 3098 | example, 1.2.3/24 is the same as 1.2.3.0/24, or 1.2.3 is the same as 1.2.3.0, |
| 3099 | which it isn't. (Those applications that do accept 1.2.3 as an IP address |
| 3100 | interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an |
| 3101 | ancient specification.) To aid in debugging these cases, we give a specific |
| 3102 | error if the pattern contains only digits and dots or contains a slash preceded |
| 3103 | only by digits and dots (a slash at the start indicates a file name and of |
| 3104 | course slashes may be present in lookups, but not preceded only by digits and |
| 3105 | dots). */ |
| 3106 | |
| 3107 | for (t = ss; isdigit(*t) || *t == '.'; t++); |
| 3108 | if (*t == 0 || (*t == '/' && t != ss)) |
| 3109 | { |
| 3110 | *error = US"malformed IPv4 address or address mask"; |
| 3111 | return ERROR; |
| 3112 | } |
| 3113 | |
| 3114 | /* See if there is a semicolon in the pattern */ |
| 3115 | |
| 3116 | semicolon = Ustrchr(ss, ';'); |
| 3117 | |
| 3118 | /* If we are doing an IP address only match, then all lookups must be IP |
| 3119 | address lookups, even if there is no "net-". */ |
| 3120 | |
| 3121 | if (isiponly) |
| 3122 | { |
| 3123 | iplookup = semicolon != NULL; |
| 3124 | } |
| 3125 | |
| 3126 | /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is |
| 3127 | a lookup on a masked IP network, in textual form. We obey this code even if we |
| 3128 | have already set iplookup, so as to skip over the "net-" prefix and to set the |
| 3129 | mask length. The net- stuff really only applies to single-key lookups where the |
| 3130 | key is implicit. For query-style lookups the key is specified in the query. |
| 3131 | From release 4.30, the use of net- for query style is no longer needed, but we |
| 3132 | retain it for backward compatibility. */ |
| 3133 | |
| 3134 | if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL) |
| 3135 | { |
| 3136 | mlen = 0; |
| 3137 | for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0'; |
| 3138 | if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */ |
| 3139 | iplookup = (*t++ == '-'); |
| 3140 | } |
| 3141 | else t = ss; |
| 3142 | |
| 3143 | /* Do the IP address lookup if that is indeed what we have */ |
| 3144 | |
| 3145 | if (iplookup) |
| 3146 | { |
| 3147 | int insize; |
| 3148 | int search_type; |
| 3149 | int incoming[4]; |
| 3150 | void *handle; |
| 3151 | uschar *filename, *key, *result; |
| 3152 | uschar buffer[64]; |
| 3153 | |
| 3154 | /* Find the search type */ |
| 3155 | |
| 3156 | search_type = search_findtype(t, semicolon - t); |
| 3157 | |
| 3158 | if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", |
| 3159 | search_error_message); |
| 3160 | |
| 3161 | /* Adjust parameters for the type of lookup. For a query-style lookup, there |
| 3162 | is no file name, and the "key" is just the query. For query-style with a file |
| 3163 | name, we have to fish the file off the start of the query. For a single-key |
| 3164 | lookup, the key is the current IP address, masked appropriately, and |
| 3165 | reconverted to text form, with the mask appended. For IPv6 addresses, specify |
| 3166 | dot separators instead of colons, except when the lookup type is "iplsearch". |
| 3167 | */ |
| 3168 | |
| 3169 | if (mac_islookup(search_type, lookup_absfilequery)) |
| 3170 | { |
| 3171 | filename = semicolon + 1; |
| 3172 | key = filename; |
| 3173 | while (*key != 0 && !isspace(*key)) key++; |
| 3174 | filename = string_copyn(filename, key - filename); |
| 3175 | while (isspace(*key)) key++; |
| 3176 | } |
| 3177 | else if (mac_islookup(search_type, lookup_querystyle)) |
| 3178 | { |
| 3179 | filename = NULL; |
| 3180 | key = semicolon + 1; |
| 3181 | } |
| 3182 | else /* Single-key style */ |
| 3183 | { |
| 3184 | int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)? |
| 3185 | ':' : '.'; |
| 3186 | insize = host_aton(cb->host_address, incoming); |
| 3187 | host_mask(insize, incoming, mlen); |
| 3188 | (void)host_nmtoa(insize, incoming, mlen, buffer, sep); |
| 3189 | key = buffer; |
| 3190 | filename = semicolon + 1; |
| 3191 | } |
| 3192 | |
| 3193 | /* Now do the actual lookup; note that there is no search_close() because |
| 3194 | of the caching arrangements. */ |
| 3195 | |
| 3196 | if (!(handle = search_open(filename, search_type, 0, NULL, NULL))) |
| 3197 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message); |
| 3198 | |
| 3199 | result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL); |
| 3200 | if (valueptr != NULL) *valueptr = result; |
| 3201 | return (result != NULL)? OK : search_find_defer? DEFER: FAIL; |
| 3202 | } |
| 3203 | |
| 3204 | /* The pattern is not an IP address or network reference of any kind. That is, |
| 3205 | it is a host name pattern. If this is an IP only match, there's an error in the |
| 3206 | host list. */ |
| 3207 | |
| 3208 | if (isiponly) |
| 3209 | { |
| 3210 | *error = US"cannot match host name in match_ip list"; |
| 3211 | return ERROR; |
| 3212 | } |
| 3213 | |
| 3214 | /* Check the characters of the pattern to see if they comprise only letters, |
| 3215 | digits, full stops, and hyphens (the constituents of domain names). Allow |
| 3216 | underscores, as they are all too commonly found. Sigh. Also, if |
| 3217 | allow_utf8_domains is set, allow top-bit characters. */ |
| 3218 | |
| 3219 | for (t = ss; *t != 0; t++) |
| 3220 | if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' && |
| 3221 | (!allow_utf8_domains || *t < 128)) break; |
| 3222 | |
| 3223 | /* If the pattern is a complete domain name, with no fancy characters, look up |
| 3224 | its IP address and match against that. Note that a multi-homed host will add |
| 3225 | items to the chain. */ |
| 3226 | |
| 3227 | if (*t == 0) |
| 3228 | { |
| 3229 | int rc; |
| 3230 | host_item h; |
| 3231 | h.next = NULL; |
| 3232 | h.name = ss; |
| 3233 | h.address = NULL; |
| 3234 | h.mx = MX_NONE; |
| 3235 | |
| 3236 | /* Using byname rather than bydns here means we cannot determine dnssec |
| 3237 | status. On the other hand it is unclear how that could be either |
| 3238 | propagated up or enforced. */ |
| 3239 | |
| 3240 | rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE); |
| 3241 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) |
| 3242 | { |
| 3243 | host_item *hh; |
| 3244 | for (hh = &h; hh != NULL; hh = hh->next) |
| 3245 | { |
| 3246 | if (host_is_in_net(hh->address, cb->host_address, 0)) return OK; |
| 3247 | } |
| 3248 | return FAIL; |
| 3249 | } |
| 3250 | if (rc == HOST_FIND_AGAIN) return DEFER; |
| 3251 | *error = string_sprintf("failed to find IP address for %s", ss); |
| 3252 | return ERROR; |
| 3253 | } |
| 3254 | |
| 3255 | /* Almost all subsequent comparisons require the host name, and can be done |
| 3256 | using the general string matching function. When this function is called for |
| 3257 | outgoing hosts, the name is always given explicitly. If it is NULL, it means we |
| 3258 | must use sender_host_name and its aliases, looking them up if necessary. */ |
| 3259 | |
| 3260 | if (cb->host_name != NULL) /* Explicit host name given */ |
| 3261 | return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE, |
| 3262 | valueptr); |
| 3263 | |
| 3264 | /* Host name not given; in principle we need the sender host name and its |
| 3265 | aliases. However, for query-style lookups, we do not need the name if the |
| 3266 | query does not contain $sender_host_name. From release 4.23, a reference to |
| 3267 | $sender_host_name causes it to be looked up, so we don't need to do the lookup |
| 3268 | on spec. */ |
| 3269 | |
| 3270 | if ((semicolon = Ustrchr(ss, ';')) != NULL) |
| 3271 | { |
| 3272 | const uschar *affix; |
| 3273 | int partial, affixlen, starflags, id; |
| 3274 | |
| 3275 | *semicolon = 0; |
| 3276 | id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags); |
| 3277 | *semicolon=';'; |
| 3278 | |
| 3279 | if (id < 0) /* Unknown lookup type */ |
| 3280 | { |
| 3281 | log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"", |
| 3282 | search_error_message, ss); |
| 3283 | return DEFER; |
| 3284 | } |
| 3285 | isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery); |
| 3286 | } |
| 3287 | |
| 3288 | if (isquery) |
| 3289 | { |
| 3290 | switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr)) |
| 3291 | { |
| 3292 | case OK: return OK; |
| 3293 | case DEFER: return DEFER; |
| 3294 | default: return FAIL; |
| 3295 | } |
| 3296 | } |
| 3297 | |
| 3298 | /* Not a query-style lookup; must ensure the host name is present, and then we |
| 3299 | do a check on the name and all its aliases. */ |
| 3300 | |
| 3301 | if (sender_host_name == NULL) |
| 3302 | { |
| 3303 | HDEBUG(D_host_lookup) |
| 3304 | debug_printf("sender host name required, to match against %s\n", ss); |
| 3305 | if (host_lookup_failed || host_name_lookup() != OK) |
| 3306 | { |
| 3307 | *error = string_sprintf("failed to find host name for %s", |
| 3308 | sender_host_address);; |
| 3309 | return ERROR; |
| 3310 | } |
| 3311 | host_build_sender_fullhost(); |
| 3312 | } |
| 3313 | |
| 3314 | /* Match on the sender host name, using the general matching function */ |
| 3315 | |
| 3316 | switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, |
| 3317 | valueptr)) |
| 3318 | { |
| 3319 | case OK: return OK; |
| 3320 | case DEFER: return DEFER; |
| 3321 | } |
| 3322 | |
| 3323 | /* If there are aliases, try matching on them. */ |
| 3324 | |
| 3325 | aliases = sender_host_aliases; |
| 3326 | while (*aliases != NULL) |
| 3327 | { |
| 3328 | switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr)) |
| 3329 | { |
| 3330 | case OK: return OK; |
| 3331 | case DEFER: return DEFER; |
| 3332 | } |
| 3333 | } |
| 3334 | return FAIL; |
| 3335 | } |
| 3336 | |
| 3337 | |
| 3338 | |
| 3339 | |
| 3340 | /************************************************* |
| 3341 | * Check a specific host matches a host list * |
| 3342 | *************************************************/ |
| 3343 | |
| 3344 | /* This function is passed a host list containing items in a number of |
| 3345 | different formats and the identity of a host. Its job is to determine whether |
| 3346 | the given host is in the set of hosts defined by the list. The host name is |
| 3347 | passed as a pointer so that it can be looked up if needed and not already |
| 3348 | known. This is commonly the case when called from verify_check_host() to check |
| 3349 | an incoming connection. When called from elsewhere the host name should usually |
| 3350 | be set. |
| 3351 | |
| 3352 | This function is now just a front end to match_check_list(), which runs common |
| 3353 | code for scanning a list. We pass it the check_host() function to perform a |
| 3354 | single test. |
| 3355 | |
| 3356 | Arguments: |
| 3357 | listptr pointer to the host list |
| 3358 | cache_bits pointer to cache for named lists, or NULL |
| 3359 | host_name the host name or NULL, implying use sender_host_name and |
| 3360 | sender_host_aliases, looking them up if required |
| 3361 | host_address the IP address |
| 3362 | valueptr if not NULL, data from a lookup is passed back here |
| 3363 | |
| 3364 | Returns: OK if the host is in the defined set |
| 3365 | FAIL if the host is not in the defined set, |
| 3366 | DEFER if a data lookup deferred (not a host lookup) |
| 3367 | |
| 3368 | If the host name was needed in order to make a comparison, and could not be |
| 3369 | determined from the IP address, the result is FAIL unless the item |
| 3370 | "+allow_unknown" was met earlier in the list, in which case OK is returned. */ |
| 3371 | |
| 3372 | int |
| 3373 | verify_check_this_host(const uschar **listptr, unsigned int *cache_bits, |
| 3374 | const uschar *host_name, const uschar *host_address, const uschar **valueptr) |
| 3375 | { |
| 3376 | int rc; |
| 3377 | unsigned int *local_cache_bits = cache_bits; |
| 3378 | const uschar *save_host_address = deliver_host_address; |
| 3379 | check_host_block cb; |
| 3380 | cb.host_name = host_name; |
| 3381 | cb.host_address = host_address; |
| 3382 | |
| 3383 | if (valueptr != NULL) *valueptr = NULL; |
| 3384 | |
| 3385 | /* If the host address starts off ::ffff: it is an IPv6 address in |
| 3386 | IPv4-compatible mode. Find the IPv4 part for checking against IPv4 |
| 3387 | addresses. */ |
| 3388 | |
| 3389 | cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)? |
| 3390 | host_address + 7 : host_address; |
| 3391 | |
| 3392 | /* During the running of the check, put the IP address into $host_address. In |
| 3393 | the case of calls from the smtp transport, it will already be there. However, |
| 3394 | in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on |
| 3395 | the safe side, any existing setting is preserved, though as I write this |
| 3396 | (November 2004) I can't see any cases where it is actually needed. */ |
| 3397 | |
| 3398 | deliver_host_address = host_address; |
| 3399 | rc = match_check_list( |
| 3400 | listptr, /* the list */ |
| 3401 | 0, /* separator character */ |
| 3402 | &hostlist_anchor, /* anchor pointer */ |
| 3403 | &local_cache_bits, /* cache pointer */ |
| 3404 | check_host, /* function for testing */ |
| 3405 | &cb, /* argument for function */ |
| 3406 | MCL_HOST, /* type of check */ |
| 3407 | (host_address == sender_host_address)? |
| 3408 | US"host" : host_address, /* text for debugging */ |
| 3409 | valueptr); /* where to pass back data */ |
| 3410 | deliver_host_address = save_host_address; |
| 3411 | return rc; |
| 3412 | } |
| 3413 | |
| 3414 | |
| 3415 | |
| 3416 | |
| 3417 | /************************************************* |
| 3418 | * Check the given host item matches a list * |
| 3419 | *************************************************/ |
| 3420 | int |
| 3421 | verify_check_given_host(uschar **listptr, host_item *host) |
| 3422 | { |
| 3423 | return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL); |
| 3424 | } |
| 3425 | |
| 3426 | /************************************************* |
| 3427 | * Check the remote host matches a list * |
| 3428 | *************************************************/ |
| 3429 | |
| 3430 | /* This is a front end to verify_check_this_host(), created because checking |
| 3431 | the remote host is a common occurrence. With luck, a good compiler will spot |
| 3432 | the tail recursion and optimize it. If there's no host address, this is |
| 3433 | command-line SMTP input - check against an empty string for the address. |
| 3434 | |
| 3435 | Arguments: |
| 3436 | listptr pointer to the host list |
| 3437 | |
| 3438 | Returns: the yield of verify_check_this_host(), |
| 3439 | i.e. OK, FAIL, or DEFER |
| 3440 | */ |
| 3441 | |
| 3442 | int |
| 3443 | verify_check_host(uschar **listptr) |
| 3444 | { |
| 3445 | return verify_check_this_host(CUSS listptr, sender_host_cache, NULL, |
| 3446 | (sender_host_address == NULL)? US"" : sender_host_address, NULL); |
| 3447 | } |
| 3448 | |
| 3449 | |
| 3450 | |
| 3451 | |
| 3452 | |
| 3453 | /************************************************* |
| 3454 | * Invert an IP address * |
| 3455 | *************************************************/ |
| 3456 | |
| 3457 | /* Originally just used for DNS xBL lists, now also used for the |
| 3458 | reverse_ip expansion operator. |
| 3459 | |
| 3460 | Arguments: |
| 3461 | buffer where to put the answer |
| 3462 | address the address to invert |
| 3463 | */ |
| 3464 | |
| 3465 | void |
| 3466 | invert_address(uschar *buffer, uschar *address) |
| 3467 | { |
| 3468 | int bin[4]; |
| 3469 | uschar *bptr = buffer; |
| 3470 | |
| 3471 | /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer |
| 3472 | to the IPv4 part only. */ |
| 3473 | |
| 3474 | if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7; |
| 3475 | |
| 3476 | /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is |
| 3477 | always 1. */ |
| 3478 | |
| 3479 | if (host_aton(address, bin) == 1) |
| 3480 | { |
| 3481 | int i; |
| 3482 | int x = bin[0]; |
| 3483 | for (i = 0; i < 4; i++) |
| 3484 | { |
| 3485 | sprintf(CS bptr, "%d.", x & 255); |
| 3486 | while (*bptr) bptr++; |
| 3487 | x >>= 8; |
| 3488 | } |
| 3489 | } |
| 3490 | |
| 3491 | /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses |
| 3492 | in any DNS black lists, and the format in which they will be looked up is |
| 3493 | unknown. This is just a guess. */ |
| 3494 | |
| 3495 | #if HAVE_IPV6 |
| 3496 | else |
| 3497 | { |
| 3498 | int i, j; |
| 3499 | for (j = 3; j >= 0; j--) |
| 3500 | { |
| 3501 | int x = bin[j]; |
| 3502 | for (i = 0; i < 8; i++) |
| 3503 | { |
| 3504 | sprintf(CS bptr, "%x.", x & 15); |
| 3505 | while (*bptr) bptr++; |
| 3506 | x >>= 4; |
| 3507 | } |
| 3508 | } |
| 3509 | } |
| 3510 | #endif |
| 3511 | |
| 3512 | /* Remove trailing period -- this is needed so that both arbitrary |
| 3513 | dnsbl keydomains and inverted addresses may be combined with the |
| 3514 | same format string, "%s.%s" */ |
| 3515 | |
| 3516 | *(--bptr) = 0; |
| 3517 | } |
| 3518 | |
| 3519 | |
| 3520 | |
| 3521 | /************************************************* |
| 3522 | * Perform a single dnsbl lookup * |
| 3523 | *************************************************/ |
| 3524 | |
| 3525 | /* This function is called from verify_check_dnsbl() below. It is also called |
| 3526 | recursively from within itself when domain and domain_txt are different |
| 3527 | pointers, in order to get the TXT record from the alternate domain. |
| 3528 | |
| 3529 | Arguments: |
| 3530 | domain the outer dnsbl domain |
| 3531 | domain_txt alternate domain to lookup TXT record on success; when the |
| 3532 | same domain is to be used, domain_txt == domain (that is, |
| 3533 | the pointers must be identical, not just the text) |
| 3534 | keydomain the current keydomain (for debug message) |
| 3535 | prepend subdomain to lookup (like keydomain, but |
| 3536 | reversed if IP address) |
| 3537 | iplist the list of matching IP addresses, or NULL for "any" |
| 3538 | bitmask true if bitmask matching is wanted |
| 3539 | match_type condition for 'succeed' result |
| 3540 | 0 => Any RR in iplist (=) |
| 3541 | 1 => No RR in iplist (!=) |
| 3542 | 2 => All RRs in iplist (==) |
| 3543 | 3 => Some RRs not in iplist (!==) |
| 3544 | the two bits are defined as MT_NOT and MT_ALL |
| 3545 | defer_return what to return for a defer |
| 3546 | |
| 3547 | Returns: OK if lookup succeeded |
| 3548 | FAIL if not |
| 3549 | */ |
| 3550 | |
| 3551 | static int |
| 3552 | one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain, |
| 3553 | uschar *prepend, uschar *iplist, BOOL bitmask, int match_type, |
| 3554 | int defer_return) |
| 3555 | { |
| 3556 | dns_answer dnsa; |
| 3557 | dns_scan dnss; |
| 3558 | tree_node *t; |
| 3559 | dnsbl_cache_block *cb; |
| 3560 | int old_pool = store_pool; |
| 3561 | uschar query[256]; /* DNS domain max length */ |
| 3562 | |
| 3563 | /* Construct the specific query domainname */ |
| 3564 | |
| 3565 | if (!string_format(query, sizeof(query), "%s.%s", prepend, domain)) |
| 3566 | { |
| 3567 | log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long " |
| 3568 | "(ignored): %s...", query); |
| 3569 | return FAIL; |
| 3570 | } |
| 3571 | |
| 3572 | /* Look for this query in the cache. */ |
| 3573 | |
| 3574 | if ( (t = tree_search(dnsbl_cache, query)) |
| 3575 | && (cb = t->data.ptr)->expiry > time(NULL) |
| 3576 | ) |
| 3577 | |
| 3578 | /* Previous lookup was cached */ |
| 3579 | |
| 3580 | { |
| 3581 | HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n"); |
| 3582 | } |
| 3583 | |
| 3584 | /* If not cached from a previous lookup, we must do a DNS lookup, and |
| 3585 | cache the result in permanent memory. */ |
| 3586 | |
| 3587 | else |
| 3588 | { |
| 3589 | uint ttl = 3600; |
| 3590 | |
| 3591 | store_pool = POOL_PERM; |
| 3592 | |
| 3593 | if (t) |
| 3594 | { |
| 3595 | HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; "); |
| 3596 | } |
| 3597 | |
| 3598 | else |
| 3599 | { /* Set up a tree entry to cache the lookup */ |
| 3600 | t = store_get(sizeof(tree_node) + Ustrlen(query)); |
| 3601 | Ustrcpy(t->name, query); |
| 3602 | t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block)); |
| 3603 | (void)tree_insertnode(&dnsbl_cache, t); |
| 3604 | } |
| 3605 | |
| 3606 | /* Do the DNS loopup . */ |
| 3607 | |
| 3608 | HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query); |
| 3609 | cb->rc = dns_basic_lookup(&dnsa, query, T_A); |
| 3610 | cb->text_set = FALSE; |
| 3611 | cb->text = NULL; |
| 3612 | cb->rhs = NULL; |
| 3613 | |
| 3614 | /* If the lookup succeeded, cache the RHS address. The code allows for |
| 3615 | more than one address - this was for complete generality and the possible |
| 3616 | use of A6 records. However, A6 records have been reduced to experimental |
| 3617 | status (August 2001) and may die out. So they may never get used at all, |
| 3618 | let alone in dnsbl records. However, leave the code here, just in case. |
| 3619 | |
| 3620 | Quite apart from one A6 RR generating multiple addresses, there are DNS |
| 3621 | lists that return more than one A record, so we must handle multiple |
| 3622 | addresses generated in that way as well. |
| 3623 | |
| 3624 | Mark the cache entry with the "now" plus the minimum of the address TTLs, |
| 3625 | or some suitably far-future time if none were found. */ |
| 3626 | |
| 3627 | if (cb->rc == DNS_SUCCEED) |
| 3628 | { |
| 3629 | dns_record *rr; |
| 3630 | dns_address **addrp = &(cb->rhs); |
| 3631 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 3632 | rr; |
| 3633 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 3634 | { |
| 3635 | if (rr->type == T_A) |
| 3636 | { |
| 3637 | dns_address *da = dns_address_from_rr(&dnsa, rr); |
| 3638 | if (da) |
| 3639 | { |
| 3640 | *addrp = da; |
| 3641 | while (da->next != NULL) da = da->next; |
| 3642 | addrp = &(da->next); |
| 3643 | if (ttl > rr->ttl) ttl = rr->ttl; |
| 3644 | } |
| 3645 | } |
| 3646 | } |
| 3647 | |
| 3648 | /* If we didn't find any A records, change the return code. This can |
| 3649 | happen when there is a CNAME record but there are no A records for what |
| 3650 | it points to. */ |
| 3651 | |
| 3652 | if (cb->rhs == NULL) cb->rc = DNS_NODATA; |
| 3653 | } |
| 3654 | |
| 3655 | cb->expiry = time(NULL)+ttl; |
| 3656 | store_pool = old_pool; |
| 3657 | } |
| 3658 | |
| 3659 | /* We now have the result of the DNS lookup, either newly done, or cached |
| 3660 | from a previous call. If the lookup succeeded, check against the address |
| 3661 | list if there is one. This may be a positive equality list (introduced by |
| 3662 | "="), a negative equality list (introduced by "!="), a positive bitmask |
| 3663 | list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/ |
| 3664 | |
| 3665 | if (cb->rc == DNS_SUCCEED) |
| 3666 | { |
| 3667 | dns_address *da = NULL; |
| 3668 | uschar *addlist = cb->rhs->address; |
| 3669 | |
| 3670 | /* For A and AAAA records, there may be multiple addresses from multiple |
| 3671 | records. For A6 records (currently not expected to be used) there may be |
| 3672 | multiple addresses from a single record. */ |
| 3673 | |
| 3674 | for (da = cb->rhs->next; da != NULL; da = da->next) |
| 3675 | addlist = string_sprintf("%s, %s", addlist, da->address); |
| 3676 | |
| 3677 | HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n", |
| 3678 | query, addlist); |
| 3679 | |
| 3680 | /* Address list check; this can be either for equality, or via a bitmask. |
| 3681 | In the latter case, all the bits must match. */ |
| 3682 | |
| 3683 | if (iplist != NULL) |
| 3684 | { |
| 3685 | for (da = cb->rhs; da != NULL; da = da->next) |
| 3686 | { |
| 3687 | int ipsep = ','; |
| 3688 | uschar ip[46]; |
| 3689 | const uschar *ptr = iplist; |
| 3690 | uschar *res; |
| 3691 | |
| 3692 | /* Handle exact matching */ |
| 3693 | |
| 3694 | if (!bitmask) |
| 3695 | { |
| 3696 | while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL) |
| 3697 | { |
| 3698 | if (Ustrcmp(CS da->address, ip) == 0) break; |
| 3699 | } |
| 3700 | } |
| 3701 | |
| 3702 | /* Handle bitmask matching */ |
| 3703 | |
| 3704 | else |
| 3705 | { |
| 3706 | int address[4]; |
| 3707 | int mask = 0; |
| 3708 | |
| 3709 | /* At present, all known DNS blocking lists use A records, with |
| 3710 | IPv4 addresses on the RHS encoding the information they return. I |
| 3711 | wonder if this will linger on as the last vestige of IPv4 when IPv6 |
| 3712 | is ubiquitous? Anyway, for now we use paranoia code to completely |
| 3713 | ignore IPv6 addresses. The default mask is 0, which always matches. |
| 3714 | We change this only for IPv4 addresses in the list. */ |
| 3715 | |
| 3716 | if (host_aton(da->address, address) == 1) mask = address[0]; |
| 3717 | |
| 3718 | /* Scan the returned addresses, skipping any that are IPv6 */ |
| 3719 | |
| 3720 | while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL) |
| 3721 | { |
| 3722 | if (host_aton(ip, address) != 1) continue; |
| 3723 | if ((address[0] & mask) == address[0]) break; |
| 3724 | } |
| 3725 | } |
| 3726 | |
| 3727 | /* If either |
| 3728 | |
| 3729 | (a) An IP address in an any ('=') list matched, or |
| 3730 | (b) No IP address in an all ('==') list matched |
| 3731 | |
| 3732 | then we're done searching. */ |
| 3733 | |
| 3734 | if (((match_type & MT_ALL) != 0) == (res == NULL)) break; |
| 3735 | } |
| 3736 | |
| 3737 | /* If da == NULL, either |
| 3738 | |
| 3739 | (a) No IP address in an any ('=') list matched, or |
| 3740 | (b) An IP address in an all ('==') list didn't match |
| 3741 | |
| 3742 | so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on |
| 3743 | the list. */ |
| 3744 | |
| 3745 | if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL)) |
| 3746 | { |
| 3747 | HDEBUG(D_dnsbl) |
| 3748 | { |
| 3749 | uschar *res = NULL; |
| 3750 | switch(match_type) |
| 3751 | { |
| 3752 | case 0: |
| 3753 | res = US"was no match"; |
| 3754 | break; |
| 3755 | case MT_NOT: |
| 3756 | res = US"was an exclude match"; |
| 3757 | break; |
| 3758 | case MT_ALL: |
| 3759 | res = US"was an IP address that did not match"; |
| 3760 | break; |
| 3761 | case MT_NOT|MT_ALL: |
| 3762 | res = US"were no IP addresses that did not match"; |
| 3763 | break; |
| 3764 | } |
| 3765 | debug_printf("=> but we are not accepting this block class because\n"); |
| 3766 | debug_printf("=> there %s for %s%c%s\n", |
| 3767 | res, |
| 3768 | ((match_type & MT_ALL) == 0)? "" : "=", |
| 3769 | bitmask? '&' : '=', iplist); |
| 3770 | } |
| 3771 | return FAIL; |
| 3772 | } |
| 3773 | } |
| 3774 | |
| 3775 | /* Either there was no IP list, or the record matched, implying that the |
| 3776 | domain is on the list. We now want to find a corresponding TXT record. If an |
| 3777 | alternate domain is specified for the TXT record, call this function |
| 3778 | recursively to look that up; this has the side effect of re-checking that |
| 3779 | there is indeed an A record at the alternate domain. */ |
| 3780 | |
| 3781 | if (domain_txt != domain) |
| 3782 | return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL, |
| 3783 | FALSE, match_type, defer_return); |
| 3784 | |
| 3785 | /* If there is no alternate domain, look up a TXT record in the main domain |
| 3786 | if it has not previously been cached. */ |
| 3787 | |
| 3788 | if (!cb->text_set) |
| 3789 | { |
| 3790 | cb->text_set = TRUE; |
| 3791 | if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED) |
| 3792 | { |
| 3793 | dns_record *rr; |
| 3794 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); |
| 3795 | rr != NULL; |
| 3796 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) |
| 3797 | if (rr->type == T_TXT) break; |
| 3798 | if (rr != NULL) |
| 3799 | { |
| 3800 | int len = (rr->data)[0]; |
| 3801 | if (len > 511) len = 127; |
| 3802 | store_pool = POOL_PERM; |
| 3803 | cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1)); |
| 3804 | store_pool = old_pool; |
| 3805 | } |
| 3806 | } |
| 3807 | } |
| 3808 | |
| 3809 | dnslist_value = addlist; |
| 3810 | dnslist_text = cb->text; |
| 3811 | return OK; |
| 3812 | } |
| 3813 | |
| 3814 | /* There was a problem with the DNS lookup */ |
| 3815 | |
| 3816 | if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA) |
| 3817 | { |
| 3818 | log_write(L_dnslist_defer, LOG_MAIN, |
| 3819 | "DNS list lookup defer (probably timeout) for %s: %s", query, |
| 3820 | (defer_return == OK)? US"assumed in list" : |
| 3821 | (defer_return == FAIL)? US"assumed not in list" : |
| 3822 | US"returned DEFER"); |
| 3823 | return defer_return; |
| 3824 | } |
| 3825 | |
| 3826 | /* No entry was found in the DNS; continue for next domain */ |
| 3827 | |
| 3828 | HDEBUG(D_dnsbl) |
| 3829 | { |
| 3830 | debug_printf("DNS lookup for %s failed\n", query); |
| 3831 | debug_printf("=> that means %s is not listed at %s\n", |
| 3832 | keydomain, domain); |
| 3833 | } |
| 3834 | |
| 3835 | return FAIL; |
| 3836 | } |
| 3837 | |
| 3838 | |
| 3839 | |
| 3840 | |
| 3841 | /************************************************* |
| 3842 | * Check host against DNS black lists * |
| 3843 | *************************************************/ |
| 3844 | |
| 3845 | /* This function runs checks against a list of DNS black lists, until one |
| 3846 | matches. Each item on the list can be of the form |
| 3847 | |
| 3848 | domain=ip-address/key |
| 3849 | |
| 3850 | The domain is the right-most domain that is used for the query, for example, |
| 3851 | blackholes.mail-abuse.org. If the IP address is present, there is a match only |
| 3852 | if the DNS lookup returns a matching IP address. Several addresses may be |
| 3853 | given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2. |
| 3854 | |
| 3855 | If no key is given, what is looked up in the domain is the inverted IP address |
| 3856 | of the current client host. If a key is given, it is used to construct the |
| 3857 | domain for the lookup. For example: |
| 3858 | |
| 3859 | dsn.rfc-ignorant.org/$sender_address_domain |
| 3860 | |
| 3861 | After finding a match in the DNS, the domain is placed in $dnslist_domain, and |
| 3862 | then we check for a TXT record for an error message, and if found, save its |
| 3863 | value in $dnslist_text. We also cache everything in a tree, to optimize |
| 3864 | multiple lookups. |
| 3865 | |
| 3866 | The TXT record is normally looked up in the same domain as the A record, but |
| 3867 | when many lists are combined in a single DNS domain, this will not be a very |
| 3868 | specific message. It is possible to specify a different domain for looking up |
| 3869 | TXT records; this is given before the main domain, comma-separated. For |
| 3870 | example: |
| 3871 | |
| 3872 | dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \ |
| 3873 | socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 |
| 3874 | |
| 3875 | The caching ensures that only one lookup in dnsbl.sorbs.net is done. |
| 3876 | |
| 3877 | Note: an address for testing RBL is 192.203.178.39 |
| 3878 | Note: an address for testing DUL is 192.203.178.4 |
| 3879 | Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org |
| 3880 | |
| 3881 | Arguments: |
| 3882 | where the acl type |
| 3883 | listptr the domain/address/data list |
| 3884 | log_msgptr log message on error |
| 3885 | |
| 3886 | Returns: OK successful lookup (i.e. the address is on the list), or |
| 3887 | lookup deferred after +include_unknown |
| 3888 | FAIL name not found, or no data found for the given type, or |
| 3889 | lookup deferred after +exclude_unknown (default) |
| 3890 | DEFER lookup failure, if +defer_unknown was set |
| 3891 | */ |
| 3892 | |
| 3893 | int |
| 3894 | verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr) |
| 3895 | { |
| 3896 | int sep = 0; |
| 3897 | int defer_return = FAIL; |
| 3898 | const uschar *list = *listptr; |
| 3899 | uschar *domain; |
| 3900 | uschar *s; |
| 3901 | uschar buffer[1024]; |
| 3902 | uschar revadd[128]; /* Long enough for IPv6 address */ |
| 3903 | |
| 3904 | /* Indicate that the inverted IP address is not yet set up */ |
| 3905 | |
| 3906 | revadd[0] = 0; |
| 3907 | |
| 3908 | /* In case this is the first time the DNS resolver is being used. */ |
| 3909 | |
| 3910 | dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */ |
| 3911 | |
| 3912 | /* Loop through all the domains supplied, until something matches */ |
| 3913 | |
| 3914 | while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) |
| 3915 | { |
| 3916 | int rc; |
| 3917 | BOOL bitmask = FALSE; |
| 3918 | int match_type = 0; |
| 3919 | uschar *domain_txt; |
| 3920 | uschar *comma; |
| 3921 | uschar *iplist; |
| 3922 | uschar *key; |
| 3923 | |
| 3924 | HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain); |
| 3925 | |
| 3926 | /* Deal with special values that change the behaviour on defer */ |
| 3927 | |
| 3928 | if (domain[0] == '+') |
| 3929 | { |
| 3930 | if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK; |
| 3931 | else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL; |
| 3932 | else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER; |
| 3933 | else |
| 3934 | log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s", |
| 3935 | domain); |
| 3936 | continue; |
| 3937 | } |
| 3938 | |
| 3939 | /* See if there's explicit data to be looked up */ |
| 3940 | |
| 3941 | if ((key = Ustrchr(domain, '/'))) *key++ = 0; |
| 3942 | |
| 3943 | /* See if there's a list of addresses supplied after the domain name. This is |
| 3944 | introduced by an = or a & character; if preceded by = we require all matches |
| 3945 | and if preceded by ! we invert the result. */ |
| 3946 | |
| 3947 | if (!(iplist = Ustrchr(domain, '='))) |
| 3948 | { |
| 3949 | bitmask = TRUE; |
| 3950 | iplist = Ustrchr(domain, '&'); |
| 3951 | } |
| 3952 | |
| 3953 | if (iplist) /* Found either = or & */ |
| 3954 | { |
| 3955 | if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */ |
| 3956 | { |
| 3957 | match_type |= MT_NOT; |
| 3958 | iplist[-1] = 0; |
| 3959 | } |
| 3960 | |
| 3961 | *iplist++ = 0; /* Terminate domain, move on */ |
| 3962 | |
| 3963 | /* If we found = (bitmask == FALSE), check for == or =& */ |
| 3964 | |
| 3965 | if (!bitmask && (*iplist == '=' || *iplist == '&')) |
| 3966 | { |
| 3967 | bitmask = *iplist++ == '&'; |
| 3968 | match_type |= MT_ALL; |
| 3969 | } |
| 3970 | } |
| 3971 | |
| 3972 | |
| 3973 | /* If there is a comma in the domain, it indicates that a second domain for |
| 3974 | looking up TXT records is provided, before the main domain. Otherwise we must |
| 3975 | set domain_txt == domain. */ |
| 3976 | |
| 3977 | domain_txt = domain; |
| 3978 | comma = Ustrchr(domain, ','); |
| 3979 | if (comma != NULL) |
| 3980 | { |
| 3981 | *comma++ = 0; |
| 3982 | domain = comma; |
| 3983 | } |
| 3984 | |
| 3985 | /* Check that what we have left is a sensible domain name. There is no reason |
| 3986 | why these domains should in fact use the same syntax as hosts and email |
| 3987 | domains, but in practice they seem to. However, there is little point in |
| 3988 | actually causing an error here, because that would no doubt hold up incoming |
| 3989 | mail. Instead, I'll just log it. */ |
| 3990 | |
| 3991 | for (s = domain; *s != 0; s++) |
| 3992 | { |
| 3993 | if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_') |
| 3994 | { |
| 3995 | log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains " |
| 3996 | "strange characters - is this right?", domain); |
| 3997 | break; |
| 3998 | } |
| 3999 | } |
| 4000 | |
| 4001 | /* Check the alternate domain if present */ |
| 4002 | |
| 4003 | if (domain_txt != domain) for (s = domain_txt; *s != 0; s++) |
| 4004 | { |
| 4005 | if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_') |
| 4006 | { |
| 4007 | log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains " |
| 4008 | "strange characters - is this right?", domain_txt); |
| 4009 | break; |
| 4010 | } |
| 4011 | } |
| 4012 | |
| 4013 | /* If there is no key string, construct the query by adding the domain name |
| 4014 | onto the inverted host address, and perform a single DNS lookup. */ |
| 4015 | |
| 4016 | if (key == NULL) |
| 4017 | { |
| 4018 | if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP) |
| 4019 | { |
| 4020 | *log_msgptr = string_sprintf |
| 4021 | ("cannot test auto-keyed dnslists condition in %s ACL", |
| 4022 | acl_wherenames[where]); |
| 4023 | return ERROR; |
| 4024 | } |
| 4025 | if (sender_host_address == NULL) return FAIL; /* can never match */ |
| 4026 | if (revadd[0] == 0) invert_address(revadd, sender_host_address); |
| 4027 | rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd, |
| 4028 | iplist, bitmask, match_type, defer_return); |
| 4029 | if (rc == OK) |
| 4030 | { |
| 4031 | dnslist_domain = string_copy(domain_txt); |
| 4032 | dnslist_matched = string_copy(sender_host_address); |
| 4033 | HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n", |
| 4034 | sender_host_address, dnslist_domain); |
| 4035 | } |
| 4036 | if (rc != FAIL) return rc; /* OK or DEFER */ |
| 4037 | } |
| 4038 | |
| 4039 | /* If there is a key string, it can be a list of domains or IP addresses to |
| 4040 | be concatenated with the main domain. */ |
| 4041 | |
| 4042 | else |
| 4043 | { |
| 4044 | int keysep = 0; |
| 4045 | BOOL defer = FALSE; |
| 4046 | uschar *keydomain; |
| 4047 | uschar keybuffer[256]; |
| 4048 | uschar keyrevadd[128]; |
| 4049 | |
| 4050 | while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer, |
| 4051 | sizeof(keybuffer))) != NULL) |
| 4052 | { |
| 4053 | uschar *prepend = keydomain; |
| 4054 | |
| 4055 | if (string_is_ip_address(keydomain, NULL) != 0) |
| 4056 | { |
| 4057 | invert_address(keyrevadd, keydomain); |
| 4058 | prepend = keyrevadd; |
| 4059 | } |
| 4060 | |
| 4061 | rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist, |
| 4062 | bitmask, match_type, defer_return); |
| 4063 | |
| 4064 | if (rc == OK) |
| 4065 | { |
| 4066 | dnslist_domain = string_copy(domain_txt); |
| 4067 | dnslist_matched = string_copy(keydomain); |
| 4068 | HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n", |
| 4069 | keydomain, dnslist_domain); |
| 4070 | return OK; |
| 4071 | } |
| 4072 | |
| 4073 | /* If the lookup deferred, remember this fact. We keep trying the rest |
| 4074 | of the list to see if we get a useful result, and if we don't, we return |
| 4075 | DEFER at the end. */ |
| 4076 | |
| 4077 | if (rc == DEFER) defer = TRUE; |
| 4078 | } /* continue with next keystring domain/address */ |
| 4079 | |
| 4080 | if (defer) return DEFER; |
| 4081 | } |
| 4082 | } /* continue with next dnsdb outer domain */ |
| 4083 | |
| 4084 | return FAIL; |
| 4085 | } |
| 4086 | |
| 4087 | /* vi: aw ai sw=2 |
| 4088 | */ |
| 4089 | /* End of verify.c */ |