1 /* $NetBSD: resolve.c,v 1.1.1.1 2009/06/23 10:08:58 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* resolve 3 6 /* SUMMARY 7 /* mail address resolver 8 /* SYNOPSIS 9 /* #include "trivial-rewrite.h" 10 /* 11 /* void resolve_init(void) 12 /* 13 /* void resolve_proto(context, stream) 14 /* RES_CONTEXT *context; 15 /* VSTREAM *stream; 16 /* DESCRIPTION 17 /* This module implements the trivial address resolving engine. 18 /* It distinguishes between local and remote mail, and optionally 19 /* consults one or more transport tables that map a destination 20 /* to a transport, nexthop pair. 21 /* 22 /* resolve_init() initializes data structures that are private 23 /* to this module. It should be called once before using the 24 /* actual resolver routines. 25 /* 26 /* resolve_proto() implements the client-server protocol: 27 /* read one address in FQDN form, reply with a (transport, 28 /* nexthop, internalized recipient) triple. 29 /* STANDARDS 30 /* DIAGNOSTICS 31 /* Problems and transactions are logged to the syslog daemon. 32 /* BUGS 33 /* SEE ALSO 34 /* LICENSE 35 /* .ad 36 /* .fi 37 /* The Secure Mailer license must be distributed with this software. 38 /* AUTHOR(S) 39 /* Wietse Venema 40 /* IBM T.J. Watson Research 41 /* P.O. Box 704 42 /* Yorktown Heights, NY 10598, USA 43 /*--*/ 44 45 /* System library. */ 46 47 #include <sys_defs.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #ifdef STRCASECMP_IN_STRINGS_H 52 #include <strings.h> 53 #endif 54 55 /* Utility library. */ 56 57 #include <msg.h> 58 #include <vstring.h> 59 #include <vstream.h> 60 #include <vstring_vstream.h> 61 #include <split_at.h> 62 #include <valid_hostname.h> 63 #include <stringops.h> 64 #include <mymalloc.h> 65 66 /* Global library. */ 67 68 #include <mail_params.h> 69 #include <mail_proto.h> 70 #include <resolve_local.h> 71 #include <mail_conf.h> 72 #include <quote_822_local.h> 73 #include <tok822.h> 74 #include <domain_list.h> 75 #include <string_list.h> 76 #include <match_parent_style.h> 77 #include <maps.h> 78 #include <mail_addr_find.h> 79 #include <valid_mailhost_addr.h> 80 81 /* Application-specific. */ 82 83 #include "trivial-rewrite.h" 84 #include "transport.h" 85 86 /* 87 * The job of the address resolver is to map one recipient address to a 88 * triple of (channel, nexthop, recipient). The channel is the name of the 89 * delivery service specified in master.cf, the nexthop is (usually) a 90 * description of the next host to deliver to, and recipient is the final 91 * recipient address. The latter may differ from the input address as the 92 * result of stripping multiple layers of sender-specified routing. 93 * 94 * Addresses are resolved by their domain name. Known domain names are 95 * categorized into classes: local, virtual alias, virtual mailbox, relay, 96 * and everything else. Finding the address domain class is a matter of 97 * table lookups. 98 * 99 * Different address domain classes generally use different delivery channels, 100 * and may use class dependent ways to arrive at the corresponding nexthop 101 * information. With classes that do final delivery, the nexthop is 102 * typically the local machine hostname. 103 * 104 * The transport lookup table provides a means to override the domain class 105 * channel and/or nexhop information for specific recipients or for entire 106 * domain hierarchies. 107 * 108 * This works well in the general case. The only bug in this approach is that 109 * the structure of the nexthop information is transport dependent. 110 * Typically, the nexthop specifies a hostname, hostname + TCP Port, or the 111 * pathname of a UNIX-domain socket. However, with the error transport the 112 * nexthop field contains free text with the reason for non-delivery. 113 * 114 * Therefore, a transport map entry that overrides the channel but not the 115 * nexthop information (or vice versa) may produce surprising results. In 116 * particular, the free text nexthop information for the error transport is 117 * likely to confuse regular delivery agents; and conversely, a hostname or 118 * socket pathname is not an adequate text as reason for non-delivery. 119 * 120 * In the code below, rcpt_domain specifies the domain name that we will use 121 * when the transport table specifies a non-default channel but no nexthop 122 * information (we use a generic text when that non-default channel is the 123 * error transport). 124 */ 125 126 #define STR vstring_str 127 128 /* 129 * Some of the lists that define the address domain classes. 130 */ 131 static DOMAIN_LIST *relay_domains; 132 static STRING_LIST *virt_alias_doms; 133 static STRING_LIST *virt_mailbox_doms; 134 135 static MAPS *relocated_maps; 136 137 /* resolve_addr - resolve address according to rule set */ 138 139 static void resolve_addr(RES_CONTEXT *rp, char *sender, char *addr, 140 VSTRING *channel, VSTRING *nexthop, 141 VSTRING *nextrcpt, int *flags) 142 { 143 const char *myname = "resolve_addr"; 144 VSTRING *addr_buf = vstring_alloc(100); 145 TOK822 *tree = 0; 146 TOK822 *saved_domain = 0; 147 TOK822 *domain = 0; 148 char *destination; 149 const char *blame = 0; 150 const char *rcpt_domain; 151 ssize_t addr_len; 152 ssize_t loop_count; 153 ssize_t loop_max; 154 char *local; 155 char *oper; 156 char *junk; 157 const char *relay; 158 159 *flags = 0; 160 vstring_strcpy(channel, "CHANNEL NOT UPDATED"); 161 vstring_strcpy(nexthop, "NEXTHOP NOT UPDATED"); 162 vstring_strcpy(nextrcpt, "NEXTRCPT NOT UPDATED"); 163 164 /* 165 * The address is in internalized (unquoted) form. 166 * 167 * In an ideal world we would parse the externalized address form as given 168 * to us by the sender. 169 * 170 * However, in the real world we have to look for routing characters like 171 * %@! in the address local-part, even when that information is quoted 172 * due to the presence of special characters or whitespace. Although 173 * technically incorrect, this is needed to stop user@domain@domain relay 174 * attempts when forwarding mail to a Sendmail MX host. 175 * 176 * This suggests that we parse the address in internalized (unquoted) form. 177 * Unfortunately, if we do that, the unparser generates incorrect white 178 * space between adjacent non-operator tokens. Example: ``first last'' 179 * needs white space, but ``stuff[stuff]'' does not. This is is not a 180 * problem when unparsing the result from parsing externalized forms, 181 * because the parser/unparser were designed for valid externalized forms 182 * where ``stuff[stuff]'' does not happen. 183 * 184 * As a workaround we start with the quoted form and then dequote the 185 * local-part only where needed. This will do the right thing in most 186 * (but not all) cases. 187 */ 188 addr_len = strlen(addr); 189 quote_822_local(addr_buf, addr); 190 tree = tok822_scan_addr(vstring_str(addr_buf)); 191 192 /* 193 * The optimizer will eliminate tests that always fail, and will replace 194 * multiple expansions of this macro by a GOTO to a single instance. 195 */ 196 #define FREE_MEMORY_AND_RETURN { \ 197 if (saved_domain) \ 198 tok822_free_tree(saved_domain); \ 199 if(tree) \ 200 tok822_free_tree(tree); \ 201 if (addr_buf) \ 202 vstring_free(addr_buf); \ 203 return; \ 204 } 205 206 /* 207 * Preliminary resolver: strip off all instances of the local domain. 208 * Terminate when no destination domain is left over, or when the 209 * destination domain is remote. 210 * 211 * XXX To whom it may concern. If you change the resolver loop below, or 212 * quote_822_local.c, or tok822_parse.c, be sure to re-run the tests 213 * under "make resolve_clnt_test" in the global directory. 214 */ 215 #define RESOLVE_LOCAL(domain) \ 216 resolve_local(STR(tok822_internalize(addr_buf, domain, TOK822_STR_DEFL))) 217 218 dict_errno = 0; 219 220 for (loop_count = 0, loop_max = addr_len + 100; /* void */ ; loop_count++) { 221 222 /* 223 * Grr. resolve_local() table lookups may fail. It may be OK for 224 * local file lookup code to abort upon failure, but with 225 * network-based tables it is preferable to return an error 226 * indication to the requestor. 227 */ 228 if (dict_errno) { 229 *flags |= RESOLVE_FLAG_FAIL; 230 FREE_MEMORY_AND_RETURN; 231 } 232 233 /* 234 * XXX Should never happen, but if this happens with some 235 * pathological address, then that is not sufficient reason to 236 * disrupt the operation of an MTA. 237 */ 238 if (loop_count > loop_max) { 239 msg_warn("resolve_addr: <%s>: giving up after %ld iterations", 240 addr, (long) loop_count); 241 break; 242 } 243 244 /* 245 * Strip trailing dot at end of domain, but not dot-dot or at-dot. 246 * This merely makes diagnostics more accurate by leaving bogus 247 * addresses alone. 248 */ 249 if (tree->tail 250 && tree->tail->type == '.' 251 && tok822_rfind_type(tree->tail, '@') != 0 252 && tree->tail->prev->type != '.' 253 && tree->tail->prev->type != '@') 254 tok822_free_tree(tok822_sub_keep_before(tree, tree->tail)); 255 256 /* 257 * Strip trailing @. 258 */ 259 if (var_resolve_nulldom 260 && tree->tail 261 && tree->tail->type == '@') 262 tok822_free_tree(tok822_sub_keep_before(tree, tree->tail)); 263 264 /* 265 * Strip (and save) @domain if local. 266 */ 267 if ((domain = tok822_rfind_type(tree->tail, '@')) != 0) { 268 if (domain->next && RESOLVE_LOCAL(domain->next) == 0) 269 break; 270 tok822_sub_keep_before(tree, domain); 271 if (saved_domain) 272 tok822_free_tree(saved_domain); 273 saved_domain = domain; 274 domain = 0; /* safety for future change */ 275 } 276 277 /* 278 * After stripping the local domain, if any, replace foo%bar by 279 * foo@bar, site!user by user@site, rewrite to canonical form, and 280 * retry. 281 */ 282 if (tok822_rfind_type(tree->tail, '@') 283 || (var_swap_bangpath && tok822_rfind_type(tree->tail, '!')) 284 || (var_percent_hack && tok822_rfind_type(tree->tail, '%'))) { 285 rewrite_tree(&local_context, tree); 286 continue; 287 } 288 289 /* 290 * If the local-part is a quoted string, crack it open when we're 291 * permitted to do so and look for routing operators. This is 292 * technically incorrect, but is needed to stop relaying problems. 293 * 294 * XXX Do another feeble attempt to keep local-part info quoted. 295 */ 296 if (var_resolve_dequoted 297 && tree->head && tree->head == tree->tail 298 && tree->head->type == TOK822_QSTRING 299 && ((oper = strrchr(local = STR(tree->head->vstr), '@')) != 0 300 || (var_percent_hack && (oper = strrchr(local, '%')) != 0) 301 || (var_swap_bangpath && (oper = strrchr(local, '!')) != 0))) { 302 if (*oper == '%') 303 *oper = '@'; 304 tok822_internalize(addr_buf, tree->head, TOK822_STR_DEFL); 305 if (*oper == '@') { 306 junk = mystrdup(STR(addr_buf)); 307 quote_822_local(addr_buf, junk); 308 myfree(junk); 309 } 310 tok822_free(tree->head); 311 tree->head = tok822_scan(STR(addr_buf), &tree->tail); 312 rewrite_tree(&local_context, tree); 313 continue; 314 } 315 316 /* 317 * An empty local-part or an empty quoted string local-part becomes 318 * the local MAILER-DAEMON, for consistency with our own From: 319 * message headers. 320 */ 321 if (tree->head && tree->head == tree->tail 322 && tree->head->type == TOK822_QSTRING 323 && VSTRING_LEN(tree->head->vstr) == 0) { 324 tok822_free(tree->head); 325 tree->head = 0; 326 } 327 /* XXX must be localpart only, not user@domain form. */ 328 if (tree->head == 0) 329 tree->head = tok822_scan(var_empty_addr, &tree->tail); 330 331 /* 332 * We're done. There are no domains left to strip off the address, 333 * and all null local-part information is sanitized. 334 */ 335 domain = 0; 336 break; 337 } 338 339 vstring_free(addr_buf); 340 addr_buf = 0; 341 342 /* 343 * Make sure the resolved envelope recipient has the user@domain form. If 344 * no domain was specified in the address, assume the local machine. See 345 * above for what happens with an empty address. 346 */ 347 if (domain == 0) { 348 if (saved_domain) { 349 tok822_sub_append(tree, saved_domain); 350 saved_domain = 0; 351 } else { 352 tok822_sub_append(tree, tok822_alloc('@', (char *) 0)); 353 tok822_sub_append(tree, tok822_scan(var_myhostname, (TOK822 **) 0)); 354 } 355 } 356 357 /* 358 * Transform the recipient address back to internal form. 359 * 360 * XXX This may produce incorrect results if we cracked open a quoted 361 * local-part with routing operators; see discussion above at the top of 362 * the big loop. 363 * 364 * XXX We explicitly disallow domain names in bare network address form. A 365 * network address destination should be formatted according to RFC 2821: 366 * it should be enclosed in [], and an IPv6 address should have an IPv6: 367 * prefix. 368 */ 369 tok822_internalize(nextrcpt, tree, TOK822_STR_DEFL); 370 rcpt_domain = strrchr(STR(nextrcpt), '@') + 1; 371 if (rcpt_domain == 0) 372 msg_panic("no @ in address: \"%s\"", STR(nextrcpt)); 373 if (*rcpt_domain == '[') { 374 if (!valid_mailhost_literal(rcpt_domain, DONT_GRIPE)) 375 *flags |= RESOLVE_FLAG_ERROR; 376 } else if (!valid_hostname(rcpt_domain, DONT_GRIPE)) { 377 if (var_resolve_num_dom && valid_hostaddr(rcpt_domain, DONT_GRIPE)) { 378 vstring_insert(nextrcpt, rcpt_domain - STR(nextrcpt), "[", 1); 379 vstring_strcat(nextrcpt, "]"); 380 rcpt_domain = strrchr(STR(nextrcpt), '@') + 1; 381 if (resolve_local(rcpt_domain)) /* XXX */ 382 domain = 0; 383 } else { 384 *flags |= RESOLVE_FLAG_ERROR; 385 } 386 } 387 tok822_free_tree(tree); 388 tree = 0; 389 390 /* 391 * XXX Short-cut invalid address forms. 392 */ 393 if (*flags & RESOLVE_FLAG_ERROR) { 394 *flags |= RESOLVE_CLASS_DEFAULT; 395 FREE_MEMORY_AND_RETURN; 396 } 397 398 /* 399 * Recognize routing operators in the local-part, even when we do not 400 * recognize ! or % as valid routing operators locally. This is needed to 401 * prevent backup MX hosts from relaying third-party destinations through 402 * primary MX hosts, otherwise the backup host could end up on black 403 * lists. Ignore local swap_bangpath and percent_hack settings because we 404 * can't know how the next MX host is set up. 405 */ 406 if (strcmp(STR(nextrcpt) + strcspn(STR(nextrcpt), "@!%") + 1, rcpt_domain)) 407 *flags |= RESOLVE_FLAG_ROUTED; 408 409 /* 410 * With local, virtual, relay, or other non-local destinations, give the 411 * highest precedence to transport associated nexthop information. 412 * 413 * Otherwise, with relay or other non-local destinations, the relayhost 414 * setting overrides the recipient domain name, and the sender-dependent 415 * relayhost overrides both. 416 * 417 * XXX Nag if the recipient domain is listed in multiple domain lists. The 418 * result is implementation defined, and may break when internals change. 419 * 420 * For now, we distinguish only a fixed number of address classes. 421 * Eventually this may become extensible, so that new classes can be 422 * configured with their own domain list, delivery transport, and 423 * recipient table. 424 */ 425 #define STREQ(x,y) (strcmp((x), (y)) == 0) 426 427 dict_errno = 0; 428 if (domain != 0) { 429 430 /* 431 * Virtual alias domain. 432 */ 433 if (virt_alias_doms 434 && string_list_match(virt_alias_doms, rcpt_domain)) { 435 if (var_helpful_warnings) { 436 if (virt_mailbox_doms 437 && string_list_match(virt_mailbox_doms, rcpt_domain)) 438 msg_warn("do not list domain %s in BOTH %s and %s", 439 rcpt_domain, VAR_VIRT_ALIAS_DOMS, 440 VAR_VIRT_MAILBOX_DOMS); 441 if (relay_domains 442 && domain_list_match(relay_domains, rcpt_domain)) 443 msg_warn("do not list domain %s in BOTH %s and %s", 444 rcpt_domain, VAR_VIRT_ALIAS_DOMS, 445 VAR_RELAY_DOMAINS); 446 #if 0 447 if (strcasecmp(rcpt_domain, var_myorigin) == 0) 448 msg_warn("do not list $%s (%s) in %s", 449 VAR_MYORIGIN, var_myorigin, VAR_VIRT_ALIAS_DOMS); 450 #endif 451 } 452 vstring_strcpy(channel, MAIL_SERVICE_ERROR); 453 vstring_sprintf(nexthop, "User unknown%s", 454 var_show_unk_rcpt_table ? 455 " in virtual alias table" : ""); 456 *flags |= RESOLVE_CLASS_ALIAS; 457 } else if (dict_errno != 0) { 458 msg_warn("%s lookup failure", VAR_VIRT_ALIAS_DOMS); 459 *flags |= RESOLVE_FLAG_FAIL; 460 FREE_MEMORY_AND_RETURN; 461 } 462 463 /* 464 * Virtual mailbox domain. 465 */ 466 else if (virt_mailbox_doms 467 && string_list_match(virt_mailbox_doms, rcpt_domain)) { 468 if (var_helpful_warnings) { 469 if (relay_domains 470 && domain_list_match(relay_domains, rcpt_domain)) 471 msg_warn("do not list domain %s in BOTH %s and %s", 472 rcpt_domain, VAR_VIRT_MAILBOX_DOMS, 473 VAR_RELAY_DOMAINS); 474 } 475 vstring_strcpy(channel, RES_PARAM_VALUE(rp->virt_transport)); 476 vstring_strcpy(nexthop, rcpt_domain); 477 blame = rp->virt_transport_name; 478 *flags |= RESOLVE_CLASS_VIRTUAL; 479 } else if (dict_errno != 0) { 480 msg_warn("%s lookup failure", VAR_VIRT_MAILBOX_DOMS); 481 *flags |= RESOLVE_FLAG_FAIL; 482 FREE_MEMORY_AND_RETURN; 483 } else { 484 485 /* 486 * Off-host relay destination. 487 */ 488 if (relay_domains 489 && domain_list_match(relay_domains, rcpt_domain)) { 490 vstring_strcpy(channel, RES_PARAM_VALUE(rp->relay_transport)); 491 blame = rp->relay_transport_name; 492 *flags |= RESOLVE_CLASS_RELAY; 493 } else if (dict_errno != 0) { 494 msg_warn("%s lookup failure", VAR_RELAY_DOMAINS); 495 *flags |= RESOLVE_FLAG_FAIL; 496 FREE_MEMORY_AND_RETURN; 497 } 498 499 /* 500 * Other off-host destination. 501 */ 502 else { 503 vstring_strcpy(channel, RES_PARAM_VALUE(rp->def_transport)); 504 blame = rp->def_transport_name; 505 *flags |= RESOLVE_CLASS_DEFAULT; 506 } 507 508 /* 509 * With off-host delivery, sender-dependent or global relayhost 510 * override the recipient domain. 511 */ 512 if (rp->snd_relay_info 513 && (relay = mail_addr_find(rp->snd_relay_info, *sender ? 514 sender : var_null_relay_maps_key, 515 (char **) 0)) != 0) 516 vstring_strcpy(nexthop, strcasecmp(relay, "DUNNO") == 0 ? 517 rcpt_domain : relay); 518 else if (*RES_PARAM_VALUE(rp->relayhost)) 519 vstring_strcpy(nexthop, RES_PARAM_VALUE(rp->relayhost)); 520 else 521 vstring_strcpy(nexthop, rcpt_domain); 522 } 523 } 524 525 /* 526 * Local delivery. 527 * 528 * XXX Nag if the domain is listed in multiple domain lists. The effect is 529 * implementation defined, and may break when internals change. 530 */ 531 else { 532 if (var_helpful_warnings) { 533 if (virt_alias_doms 534 && string_list_match(virt_alias_doms, rcpt_domain)) 535 msg_warn("do not list domain %s in BOTH %s and %s", 536 rcpt_domain, VAR_MYDEST, VAR_VIRT_ALIAS_DOMS); 537 if (virt_mailbox_doms 538 && string_list_match(virt_mailbox_doms, rcpt_domain)) 539 msg_warn("do not list domain %s in BOTH %s and %s", 540 rcpt_domain, VAR_MYDEST, VAR_VIRT_MAILBOX_DOMS); 541 } 542 vstring_strcpy(channel, RES_PARAM_VALUE(rp->local_transport)); 543 vstring_strcpy(nexthop, rcpt_domain); 544 blame = rp->local_transport_name; 545 *flags |= RESOLVE_CLASS_LOCAL; 546 } 547 548 /* 549 * An explicit main.cf transport:nexthop setting overrides the nexthop. 550 * 551 * XXX We depend on this mechanism to enforce per-recipient concurrencies 552 * for local recipients. With "local_transport = local:$myhostname" we 553 * force mail for any domain in $mydestination/${proxy,inet}_interfaces 554 * to share the same queue. 555 */ 556 if ((destination = split_at(STR(channel), ':')) != 0 && *destination) 557 vstring_strcpy(nexthop, destination); 558 559 /* 560 * Sanity checks. 561 */ 562 if (*STR(channel) == 0) { 563 if (blame == 0) 564 msg_panic("%s: null blame", myname); 565 msg_warn("file %s/%s: parameter %s: null transport is not allowed", 566 var_config_dir, MAIN_CONF_FILE, blame); 567 *flags |= RESOLVE_FLAG_FAIL; 568 FREE_MEMORY_AND_RETURN; 569 } 570 if (*STR(nexthop) == 0) 571 msg_panic("%s: null nexthop", myname); 572 573 /* 574 * The transport map can selectively override any transport and/or 575 * nexthop host info that is set up above. Unfortunately, the syntax for 576 * nexthop information is transport specific. We therefore need sane and 577 * intuitive semantics for transport map entries that specify a channel 578 * but no nexthop. 579 * 580 * With non-error transports, the initial nexthop information is the 581 * recipient domain. However, specific main.cf transport definitions may 582 * specify a transport-specific destination, such as a host + TCP socket, 583 * or the pathname of a UNIX-domain socket. With less precedence than 584 * main.cf transport definitions, a main.cf relayhost definition may also 585 * override nexthop information for off-host deliveries. 586 * 587 * With the error transport, the nexthop information is free text that 588 * specifies the reason for non-delivery. 589 * 590 * Because nexthop syntax is transport specific we reset the nexthop 591 * information to the recipient domain when the transport table specifies 592 * a transport without also specifying the nexthop information. 593 * 594 * Subtle note: reset nexthop even when the transport table does not change 595 * the transport. Otherwise it is hard to get rid of main.cf specified 596 * nexthop information. 597 * 598 * XXX Don't override the virtual alias class (error:User unknown) result. 599 */ 600 if (rp->transport_info && !(*flags & RESOLVE_CLASS_ALIAS)) { 601 if (transport_lookup(rp->transport_info, STR(nextrcpt), 602 rcpt_domain, channel, nexthop) == 0 603 && dict_errno != 0) { 604 msg_warn("%s lookup failure", rp->transport_maps_name); 605 *flags |= RESOLVE_FLAG_FAIL; 606 FREE_MEMORY_AND_RETURN; 607 } 608 } 609 610 /* 611 * Bounce recipients that have moved, regardless of domain address class. 612 * We do this last, in anticipation of transport maps that can override 613 * the recipient address. 614 * 615 * The downside of not doing this in delivery agents is that this table has 616 * no effect on local alias expansion results. Such mail will have to 617 * make almost an entire iteration through the mail system. 618 */ 619 #define IGNORE_ADDR_EXTENSION ((char **) 0) 620 621 if (relocated_maps != 0) { 622 const char *newloc; 623 624 if ((newloc = mail_addr_find(relocated_maps, STR(nextrcpt), 625 IGNORE_ADDR_EXTENSION)) != 0) { 626 vstring_strcpy(channel, MAIL_SERVICE_ERROR); 627 /* 5.1.6 is the closest match, but not perfect. */ 628 vstring_sprintf(nexthop, "5.1.6 User has moved to %s", newloc); 629 } else if (dict_errno != 0) { 630 msg_warn("%s lookup failure", VAR_RELOCATED_MAPS); 631 *flags |= RESOLVE_FLAG_FAIL; 632 FREE_MEMORY_AND_RETURN; 633 } 634 } 635 636 /* 637 * Bounce recipient addresses that start with `-'. External commands may 638 * misinterpret such addresses as command-line options. 639 * 640 * In theory I could say people should always carefully set up their 641 * master.cf pipe mailer entries with `--' before the first non-option 642 * argument, but mistakes will happen regardless. 643 * 644 * Therefore the protection is put in place here, where it cannot be 645 * bypassed. 646 */ 647 if (var_allow_min_user == 0 && STR(nextrcpt)[0] == '-') { 648 *flags |= RESOLVE_FLAG_ERROR; 649 FREE_MEMORY_AND_RETURN; 650 } 651 652 /* 653 * Clean up. 654 */ 655 FREE_MEMORY_AND_RETURN; 656 } 657 658 /* Static, so they can be used by the network protocol interface only. */ 659 660 static VSTRING *channel; 661 static VSTRING *nexthop; 662 static VSTRING *nextrcpt; 663 static VSTRING *query; 664 static VSTRING *sender; 665 666 /* resolve_proto - read request and send reply */ 667 668 int resolve_proto(RES_CONTEXT *context, VSTREAM *stream) 669 { 670 int flags; 671 672 if (attr_scan(stream, ATTR_FLAG_STRICT, 673 ATTR_TYPE_STR, MAIL_ATTR_SENDER, sender, 674 ATTR_TYPE_STR, MAIL_ATTR_ADDR, query, 675 ATTR_TYPE_END) != 2) 676 return (-1); 677 678 resolve_addr(context, STR(sender), STR(query), 679 channel, nexthop, nextrcpt, &flags); 680 681 if (msg_verbose) 682 msg_info("`%s' -> `%s' -> (`%s' `%s' `%s' `%d')", 683 STR(sender), STR(query), STR(channel), 684 STR(nexthop), STR(nextrcpt), flags); 685 686 attr_print(stream, ATTR_FLAG_NONE, 687 ATTR_TYPE_INT, MAIL_ATTR_FLAGS, server_flags, 688 ATTR_TYPE_STR, MAIL_ATTR_TRANSPORT, STR(channel), 689 ATTR_TYPE_STR, MAIL_ATTR_NEXTHOP, STR(nexthop), 690 ATTR_TYPE_STR, MAIL_ATTR_RECIP, STR(nextrcpt), 691 ATTR_TYPE_INT, MAIL_ATTR_FLAGS, flags, 692 ATTR_TYPE_END); 693 694 if (vstream_fflush(stream) != 0) { 695 msg_warn("write resolver reply: %m"); 696 return (-1); 697 } 698 return (0); 699 } 700 701 /* resolve_init - module initializations */ 702 703 void resolve_init(void) 704 { 705 sender = vstring_alloc(100); 706 query = vstring_alloc(100); 707 channel = vstring_alloc(100); 708 nexthop = vstring_alloc(100); 709 nextrcpt = vstring_alloc(100); 710 711 if (*var_virt_alias_doms) 712 virt_alias_doms = 713 string_list_init(MATCH_FLAG_NONE, var_virt_alias_doms); 714 715 if (*var_virt_mailbox_doms) 716 virt_mailbox_doms = 717 string_list_init(MATCH_FLAG_NONE, var_virt_mailbox_doms); 718 719 if (*var_relay_domains) 720 relay_domains = 721 domain_list_init(match_parent_style(VAR_RELAY_DOMAINS), 722 var_relay_domains); 723 724 if (*var_relocated_maps) 725 relocated_maps = 726 maps_create(VAR_RELOCATED_MAPS, var_relocated_maps, 727 DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX); 728 } 729