1 /* $NetBSD: smtp.h,v 1.5 2023/12/23 20:30:45 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* smtp 3h 6 /* SUMMARY 7 /* smtp client program 8 /* SYNOPSIS 9 /* #include "smtp.h" 10 /* DESCRIPTION 11 /* .nf 12 13 /* 14 * System library. 15 */ 16 #include <string.h> 17 18 /* 19 * Utility library. 20 */ 21 #include <vstream.h> 22 #include <vstring.h> 23 #include <argv.h> 24 #include <htable.h> 25 #include <dict.h> 26 27 /* 28 * Global library. 29 */ 30 #include <deliver_request.h> 31 #include <scache.h> 32 #include <string_list.h> 33 #include <maps.h> 34 #include <tok822.h> 35 #include <dsn_buf.h> 36 #include <header_body_checks.h> 37 38 /* 39 * Postfix TLS library. 40 */ 41 #include <tls.h> 42 43 /* 44 * tlsproxy client. 45 */ 46 #include <tls_proxy.h> 47 48 /* 49 * Global iterator support. This is updated by the connection-management 50 * loop, and contains dynamic context that appears in lookup keys for SASL 51 * passwords, TLS policy, cached SMTP connections, and cached TLS session 52 * keys. 53 * 54 * For consistency and maintainability, context that is used in more than one 55 * lookup key is formatted with smtp_key_format(). 56 */ 57 typedef struct SMTP_ITERATOR { 58 /* Public members. */ 59 VSTRING *request_nexthop; /* delivery request nexhop or empty */ 60 VSTRING *dest; /* current nexthop */ 61 VSTRING *host; /* hostname or empty */ 62 VSTRING *addr; /* printable address or empty */ 63 unsigned port; /* network byte order or null */ 64 struct DNS_RR *rr; /* DNS resource record or null */ 65 struct DNS_RR *mx; /* DNS resource record or null */ 66 /* Private members. */ 67 VSTRING *saved_dest; /* saved current nexthop */ 68 struct SMTP_STATE *parent; /* parent linkage */ 69 } SMTP_ITERATOR; 70 71 #define SMTP_ITER_INIT(iter, _dest, _host, _addr, _port, state) do { \ 72 vstring_strcpy((iter)->dest, (_dest)); \ 73 vstring_strcpy((iter)->host, (_host)); \ 74 vstring_strcpy((iter)->addr, (_addr)); \ 75 (iter)->port = (_port); \ 76 (iter)->mx = (iter)->rr = 0; \ 77 vstring_strcpy((iter)->saved_dest, ""); \ 78 (iter)->parent = (state); \ 79 } while (0) 80 81 #define SMTP_ITER_SAVE_DEST(iter) do { \ 82 vstring_strcpy((iter)->saved_dest, STR((iter)->dest)); \ 83 } while (0) 84 85 #define SMTP_ITER_RESTORE_DEST(iter) do { \ 86 vstring_strcpy((iter)->dest, STR((iter)->saved_dest)); \ 87 } while (0) 88 89 #define SMTP_ITER_UPDATE_HOST(iter, _host, _addr, _rr) do { \ 90 vstring_strcpy((iter)->host, (_host)); \ 91 vstring_strcpy((iter)->addr, (_addr)); \ 92 (iter)->rr = (_rr); \ 93 if ((_rr)->port) \ 94 (iter)->port = htons((_rr)->port); /* SRV port override */ \ 95 } while (0) 96 97 /* 98 * TLS Policy support. 99 */ 100 #ifdef USE_TLS 101 102 typedef struct SMTP_TLS_POLICY { 103 int level; /* TLS enforcement level */ 104 char *protocols; /* Acceptable SSL protocols */ 105 char *grade; /* Cipher grade: "export", ... */ 106 VSTRING *exclusions; /* Excluded SSL ciphers */ 107 ARGV *matchargv; /* Cert match patterns */ 108 DSN_BUF *why; /* Lookup error status */ 109 TLS_DANE *dane; /* DANE TLSA digests */ 110 char *sni; /* Optional SNI name when not DANE */ 111 int conn_reuse; /* enable connection reuse */ 112 } SMTP_TLS_POLICY; 113 114 /* 115 * smtp_tls_policy.c 116 */ 117 extern void smtp_tls_list_init(void); 118 extern int smtp_tls_policy_cache_query(DSN_BUF *, SMTP_TLS_POLICY *, SMTP_ITERATOR *); 119 extern void smtp_tls_policy_cache_flush(void); 120 121 /* 122 * Macros must use distinct names for local temporary variables, otherwise 123 * there will be bugs due to shadowing. This happened when an earlier 124 * version of smtp_tls_policy_dummy() invoked smtp_tls_policy_init(), but it 125 * could also happen without macro nesting. 126 * 127 * General principle: use all or part of the macro name in each temporary 128 * variable name. Then, append suffixes to the names if needed. 129 */ 130 #define smtp_tls_policy_dummy(t) do { \ 131 SMTP_TLS_POLICY *_tls_policy_dummy_tmp = (t); \ 132 smtp_tls_policy_init(_tls_policy_dummy_tmp, (DSN_BUF *) 0); \ 133 _tls_policy_dummy_tmp->level = TLS_LEV_NONE; \ 134 } while (0) 135 136 /* This macro is not part of the module external interface. */ 137 #define smtp_tls_policy_init(t, w) do { \ 138 SMTP_TLS_POLICY *_tls_policy_init_tmp = (t); \ 139 _tls_policy_init_tmp->protocols = 0; \ 140 _tls_policy_init_tmp->grade = 0; \ 141 _tls_policy_init_tmp->exclusions = 0; \ 142 _tls_policy_init_tmp->matchargv = 0; \ 143 _tls_policy_init_tmp->why = (w); \ 144 _tls_policy_init_tmp->dane = 0; \ 145 _tls_policy_init_tmp->sni = 0; \ 146 _tls_policy_init_tmp->conn_reuse = 0; \ 147 } while (0) 148 149 #endif 150 151 /* 152 * State information associated with each SMTP delivery request. 153 * Session-specific state is stored separately. 154 */ 155 typedef struct SMTP_STATE { 156 int misc_flags; /* processing flags, see below */ 157 VSTREAM *src; /* queue file stream */ 158 const char *service; /* transport name */ 159 DELIVER_REQUEST *request; /* envelope info, offsets */ 160 struct SMTP_SESSION *session; /* network connection */ 161 int status; /* delivery status */ 162 ssize_t space_left; /* output length control */ 163 164 /* 165 * Global iterator. 166 */ 167 SMTP_ITERATOR iterator[1]; /* Usage: state->iterator->member */ 168 169 /* 170 * Global iterator. 171 */ 172 #ifdef USE_TLS 173 SMTP_TLS_POLICY tls[1]; /* Usage: state->tls->member */ 174 #endif 175 176 /* 177 * Connection cache support. 178 */ 179 HTABLE *cache_used; /* cached addresses that were used */ 180 VSTRING *dest_label; /* cached logical/physical binding */ 181 VSTRING *dest_prop; /* binding properties, passivated */ 182 VSTRING *endp_label; /* cached session physical endpoint */ 183 VSTRING *endp_prop; /* endpoint properties, passivated */ 184 185 /* 186 * Flags and counters to control the handling of mail delivery errors. 187 * There is some redundancy for sanity checking. At the end of an SMTP 188 * session all recipients should be marked one way or the other. 189 */ 190 int rcpt_left; /* recipients left over */ 191 int rcpt_drop; /* recipients marked as drop */ 192 int rcpt_keep; /* recipients marked as keep */ 193 194 /* 195 * DSN Support introduced major bloat in error processing. 196 */ 197 DSN_BUF *why; /* on-the-fly formatting buffer */ 198 199 /* 200 * Whether per-nexthop debug_peer support was requested. Otherwise, 201 * assume per-server debug_peer support. 202 */ 203 int debug_peer_per_nexthop; 204 205 /* 206 * One-bit counters to avoid logging the same warning multiple times per 207 * delivery request. 208 */ 209 unsigned logged_line_length_limit:1; 210 } SMTP_STATE; 211 212 /* 213 * Primitives to enable/disable/test connection caching and reuse based on 214 * the delivery request next-hop destination (i.e. not smtp_fallback_relay). 215 * 216 * Connection cache lookup by the delivery request next-hop destination allows 217 * a reuse request to skip over bad hosts, and may result in a connection to 218 * a fall-back relay. Once we have found a 'good' host for a delivery 219 * request next-hop, clear the delivery request next-hop destination, to 220 * avoid caching less-preferred connections under that same delivery request 221 * next-hop. 222 */ 223 #define SET_SCACHE_REQUEST_NEXTHOP(state, nexthop) do { \ 224 vstring_strcpy((state)->iterator->request_nexthop, nexthop); \ 225 } while (0) 226 227 #define CLEAR_SCACHE_REQUEST_NEXTHOP(state) do { \ 228 STR((state)->iterator->request_nexthop)[0] = 0; \ 229 } while (0) 230 231 #define HAVE_SCACHE_REQUEST_NEXTHOP(state) \ 232 (STR((state)->iterator->request_nexthop)[0] != 0) 233 234 235 /* 236 * Server features. 237 */ 238 #define SMTP_FEATURE_ESMTP (1<<0) 239 #define SMTP_FEATURE_8BITMIME (1<<1) 240 #define SMTP_FEATURE_PIPELINING (1<<2) 241 #define SMTP_FEATURE_SIZE (1<<3) 242 #define SMTP_FEATURE_STARTTLS (1<<4) 243 #define SMTP_FEATURE_AUTH (1<<5) 244 #define SMTP_FEATURE_XFORWARD_NAME (1<<7) 245 #define SMTP_FEATURE_XFORWARD_ADDR (1<<8) 246 #define SMTP_FEATURE_XFORWARD_PROTO (1<<9) 247 #define SMTP_FEATURE_XFORWARD_HELO (1<<10) 248 #define SMTP_FEATURE_XFORWARD_DOMAIN (1<<11) 249 #define SMTP_FEATURE_BEST_MX (1<<12) /* for next-hop or fall-back */ 250 #define SMTP_FEATURE_RSET_REJECTED (1<<13) /* RSET probe rejected */ 251 #define SMTP_FEATURE_FROM_CACHE (1<<14) /* cached connection */ 252 #define SMTP_FEATURE_DSN (1<<15) /* DSN supported */ 253 #define SMTP_FEATURE_PIX_NO_ESMTP (1<<16) /* PIX smtp fixup mode */ 254 #define SMTP_FEATURE_PIX_DELAY_DOTCRLF (1<<17) /* PIX smtp fixup mode */ 255 #define SMTP_FEATURE_XFORWARD_PORT (1<<18) 256 #define SMTP_FEATURE_EARLY_TLS_MAIL_REPLY (1<<19) /* CVE-2009-3555 */ 257 #define SMTP_FEATURE_XFORWARD_IDENT (1<<20) 258 #define SMTP_FEATURE_SMTPUTF8 (1<<21) /* RFC 6531 */ 259 #define SMTP_FEATURE_FROM_PROXY (1<<22) /* proxied connection */ 260 261 /* 262 * Features that passivate under the endpoint. 263 */ 264 #define SMTP_FEATURE_ENDPOINT_MASK \ 265 (~(SMTP_FEATURE_BEST_MX | SMTP_FEATURE_RSET_REJECTED \ 266 | SMTP_FEATURE_FROM_CACHE)) 267 268 /* 269 * Features that passivate under the logical destination. 270 */ 271 #define SMTP_FEATURE_DESTINATION_MASK (SMTP_FEATURE_BEST_MX) 272 273 /* 274 * Misc flags. 275 */ 276 #define SMTP_MISC_FLAG_LOOP_DETECT (1<<0) 277 #define SMTP_MISC_FLAG_IN_STARTTLS (1<<1) 278 #define SMTP_MISC_FLAG_FIRST_NEXTHOP (1<<2) 279 #define SMTP_MISC_FLAG_FINAL_NEXTHOP (1<<3) 280 #define SMTP_MISC_FLAG_FINAL_SERVER (1<<4) 281 #define SMTP_MISC_FLAG_CONN_LOAD (1<<5) 282 #define SMTP_MISC_FLAG_CONN_STORE (1<<6) 283 #define SMTP_MISC_FLAG_COMPLETE_SESSION (1<<7) 284 #define SMTP_MISC_FLAG_PREF_IPV6 (1<<8) 285 #define SMTP_MISC_FLAG_PREF_IPV4 (1<<9) 286 #define SMTP_MISC_FLAG_FALLBACK_SRV_TO_MX (1<<10) 287 288 #define SMTP_MISC_FLAG_CONN_CACHE_MASK \ 289 (SMTP_MISC_FLAG_CONN_LOAD | SMTP_MISC_FLAG_CONN_STORE) 290 291 /* 292 * smtp.c 293 */ 294 #define SMTP_HAS_DSN(why) (STR((why)->status)[0] != 0) 295 #define SMTP_HAS_SOFT_DSN(why) (STR((why)->status)[0] == '4') 296 #define SMTP_HAS_HARD_DSN(why) (STR((why)->status)[0] == '5') 297 #define SMTP_HAS_LOOP_DSN(why) \ 298 (SMTP_HAS_DSN(why) && strcmp(STR((why)->status) + 1, ".4.6") == 0) 299 300 #define SMTP_SET_SOFT_DSN(why) (STR((why)->status)[0] = '4') 301 #define SMTP_SET_HARD_DSN(why) (STR((why)->status)[0] = '5') 302 303 extern int smtp_host_lookup_mask; /* host lookup methods to use */ 304 305 #define SMTP_HOST_FLAG_DNS (1<<0) 306 #define SMTP_HOST_FLAG_NATIVE (1<<1) 307 308 extern int smtp_dns_support; /* dns support level */ 309 310 #define SMTP_DNS_INVALID (-1) /* smtp_dns_support_level = <bogus> */ 311 #define SMTP_DNS_DISABLED 0 /* smtp_dns_support_level = disabled */ 312 #define SMTP_DNS_ENABLED 1 /* smtp_dns_support_level = enabled */ 313 #define SMTP_DNS_DNSSEC 2 /* smtp_dns_support_level = dnssec */ 314 315 extern SCACHE *smtp_scache; /* connection cache instance */ 316 extern STRING_LIST *smtp_cache_dest; /* cached destinations */ 317 318 extern MAPS *smtp_ehlo_dis_maps; /* ehlo keyword filter */ 319 320 extern MAPS *smtp_pix_bug_maps; /* PIX workarounds */ 321 322 extern MAPS *smtp_generic_maps; /* make internal address valid */ 323 extern int smtp_ext_prop_mask; /* address extension propagation */ 324 extern unsigned smtp_dns_res_opt; /* DNS query flags */ 325 326 extern STRING_LIST *smtp_use_srv_lookup;/* services with SRV record lookup */ 327 328 #ifdef USE_TLS 329 330 extern TLS_APPL_STATE *smtp_tls_ctx; /* client-side TLS engine */ 331 extern int smtp_tls_insecure_mx_policy; /* DANE post insecure MX? */ 332 333 #endif 334 335 extern HBC_CHECKS *smtp_header_checks; /* limited header checks */ 336 extern HBC_CHECKS *smtp_body_checks; /* limited body checks */ 337 338 /* 339 * smtp_session.c 340 */ 341 342 typedef struct SMTP_SESSION { 343 VSTREAM *stream; /* network connection */ 344 SMTP_ITERATOR *iterator; /* dest, host, addr, port */ 345 char *namaddr; /* mail exchanger */ 346 char *helo; /* helo response */ 347 unsigned port; /* network byte order */ 348 char *namaddrport; /* mail exchanger, incl. port */ 349 350 VSTRING *buffer; /* I/O buffer */ 351 VSTRING *scratch; /* scratch buffer */ 352 VSTRING *scratch2; /* scratch buffer */ 353 354 int features; /* server features */ 355 off_t size_limit; /* server limit or unknown */ 356 357 ARGV *history; /* transaction log */ 358 int error_mask; /* error classes */ 359 struct MIME_STATE *mime_state; /* mime state machine */ 360 361 int send_proto_helo; /* XFORWARD support */ 362 363 time_t expire_time; /* session reuse expiration time */ 364 int reuse_count; /* # of times reused (for logging) */ 365 int forbidden; /* No further I/O allowed */ 366 367 #ifdef USE_SASL_AUTH 368 char *sasl_mechanism_list; /* server mechanism list */ 369 char *sasl_username; /* client username */ 370 char *sasl_passwd; /* client password */ 371 struct XSASL_CLIENT *sasl_client; /* SASL internal state */ 372 VSTRING *sasl_reply; /* client response */ 373 #endif 374 375 /* 376 * TLS related state, don't forget to initialize in session_tls_init()! 377 */ 378 #ifdef USE_TLS 379 TLS_SESS_STATE *tls_context; /* TLS library session state */ 380 char *tls_nexthop; /* Nexthop domain for cert checks */ 381 int tls_retry_plain; /* Try plain when TLS handshake fails */ 382 #endif 383 384 SMTP_STATE *state; /* back link */ 385 } SMTP_SESSION; 386 387 extern SMTP_SESSION *smtp_session_alloc(VSTREAM *, SMTP_ITERATOR *, time_t, int); 388 extern void smtp_session_new_stream(SMTP_SESSION *, VSTREAM *, time_t, int); 389 extern int smtp_sess_plaintext_ok(SMTP_ITERATOR *, int); 390 extern void smtp_session_free(SMTP_SESSION *); 391 extern int smtp_session_passivate(SMTP_SESSION *, VSTRING *, VSTRING *); 392 extern SMTP_SESSION *smtp_session_activate(int, SMTP_ITERATOR *, VSTRING *, VSTRING *); 393 394 /* 395 * What's in a name? 396 */ 397 #define SMTP_HNAME(rr) (var_smtp_cname_overr ? (rr)->rname : (rr)->qname) 398 399 /* 400 * smtp_connect.c 401 */ 402 extern int smtp_connect(SMTP_STATE *); 403 404 /* 405 * smtp_proto.c 406 */ 407 extern void smtp_vrfy_init(void); 408 extern int smtp_helo(SMTP_STATE *); 409 extern int smtp_xfer(SMTP_STATE *); 410 extern int smtp_rset(SMTP_STATE *); 411 extern int smtp_quit(SMTP_STATE *); 412 413 extern HBC_CALL_BACKS smtp_hbc_callbacks[]; 414 415 /* 416 * A connection is re-usable if session->expire_time is > 0 and the 417 * expiration time has not been reached. This is subtle because the timer 418 * can expire between sending a command and receiving the reply for that 419 * command. 420 * 421 * But wait, there is more! When SMTP command pipelining is enabled, there are 422 * two protocol loops that execute at very different times: one loop that 423 * generates commands, and one loop that receives replies to those commands. 424 * These will be called "sender loop" and "receiver loop", respectively. At 425 * well-defined protocol synchronization points, the sender loop pauses to 426 * let the receiver loop catch up. 427 * 428 * When we choose to reuse a connection, both the sender and receiver protocol 429 * loops end with "." (mail delivery) or "RSET" (address probe). When we 430 * choose not to reuse, both the sender and receiver protocol loops end with 431 * "QUIT". The problem is that we must make the same protocol choices in 432 * both the sender and receiver loops, even though those loops may execute 433 * at completely different times. 434 * 435 * We "freeze" the choice in the sender loop, just before we generate "." or 436 * "RSET". The reader loop leaves the connection cacheable even if the timer 437 * expires by the time the response arrives. The connection cleanup code 438 * will call smtp_quit() for connections with an expired cache expiration 439 * timer. 440 * 441 * We could have made the programmer's life a lot simpler by not making a 442 * choice at all, and always leaving it up to the connection cleanup code to 443 * call smtp_quit() for connections with an expired cache expiration timer. 444 * 445 * As a general principle, neither the sender loop nor the receiver loop must 446 * modify the connection caching state, if that can affect the receiver 447 * state machine for not-yet processed replies to already-generated 448 * commands. This restriction does not apply when we have to exit the 449 * protocol loops prematurely due to e.g., timeout or connection loss, so 450 * that those pending replies will never be received. 451 * 452 * But wait, there is even more! Only the first good connection for a specific 453 * destination may be cached under both the next-hop destination name and 454 * the server address; connections to alternate servers must be cached under 455 * the server address alone. This means we must distinguish between bad 456 * connections and other reasons why connections cannot be cached. 457 */ 458 #define THIS_SESSION_IS_CACHED \ 459 (!THIS_SESSION_IS_FORBIDDEN && session->expire_time > 0) 460 461 #define THIS_SESSION_IS_EXPIRED \ 462 (THIS_SESSION_IS_CACHED \ 463 && (session->expire_time < vstream_ftime(session->stream) \ 464 || (var_smtp_reuse_count > 0 \ 465 && session->reuse_count >= var_smtp_reuse_count))) 466 467 #define THIS_SESSION_IS_THROTTLED \ 468 (!THIS_SESSION_IS_FORBIDDEN && session->expire_time < 0) 469 470 #define THIS_SESSION_IS_FORBIDDEN \ 471 (session->forbidden != 0) 472 473 /* Bring the bad news. */ 474 475 #define DONT_CACHE_THIS_SESSION \ 476 (session->expire_time = 0) 477 478 #define DONT_CACHE_THROTTLED_SESSION \ 479 (session->expire_time = -1) 480 481 #define DONT_USE_FORBIDDEN_SESSION \ 482 (session->forbidden = 1) 483 484 /* Initialization. */ 485 486 #define USE_NEWBORN_SESSION \ 487 (session->forbidden = 0) 488 489 #define CACHE_THIS_SESSION_UNTIL(when) \ 490 (session->expire_time = (when)) 491 492 /* 493 * Encapsulate the following so that we don't expose details of 494 * connection management and error handling to the SMTP protocol engine. 495 */ 496 #ifdef USE_SASL_AUTH 497 #define HAVE_SASL_CREDENTIALS \ 498 (var_smtp_sasl_enable \ 499 && *var_smtp_sasl_passwd \ 500 && smtp_sasl_passwd_lookup(session)) 501 #else 502 #define HAVE_SASL_CREDENTIALS (0) 503 #endif 504 505 #define PREACTIVE_DELAY \ 506 (session->state->request->msg_stats.active_arrival.tv_sec - \ 507 session->state->request->msg_stats.incoming_arrival.tv_sec) 508 509 #define TRACE_REQ_ONLY (DEL_REQ_TRACE_ONLY(state->request->flags)) 510 511 #define PLAINTEXT_FALLBACK_OK_AFTER_STARTTLS_FAILURE \ 512 (session->tls_context == 0 \ 513 && state->tls->level == TLS_LEV_MAY \ 514 && (TRACE_REQ_ONLY || PREACTIVE_DELAY >= var_min_backoff_time) \ 515 && !HAVE_SASL_CREDENTIALS) 516 517 #define PLAINTEXT_FALLBACK_OK_AFTER_TLS_SESSION_FAILURE \ 518 (session->tls_context != 0 \ 519 && SMTP_RCPT_LEFT(state) > SMTP_RCPT_MARK_COUNT(state) \ 520 && state->tls->level == TLS_LEV_MAY \ 521 && (TRACE_REQ_ONLY || PREACTIVE_DELAY >= var_min_backoff_time) \ 522 && !HAVE_SASL_CREDENTIALS) 523 524 /* 525 * XXX The following will not retry recipients that were deferred while the 526 * SMTP_MISC_FLAG_FINAL_SERVER flag was already set. This includes the case 527 * when TLS fails in the middle of a delivery. 528 */ 529 #define RETRY_AS_PLAINTEXT do { \ 530 session->tls_retry_plain = 1; \ 531 state->misc_flags &= ~SMTP_MISC_FLAG_FINAL_SERVER; \ 532 } while (0) 533 534 /* 535 * smtp_chat.c 536 */ 537 typedef struct SMTP_RESP { /* server response */ 538 int code; /* SMTP code */ 539 const char *dsn; /* enhanced status */ 540 char *str; /* full reply */ 541 VSTRING *dsn_buf; /* status buffer */ 542 VSTRING *str_buf; /* reply buffer */ 543 } SMTP_RESP; 544 545 extern void PRINTFLIKE(2, 3) smtp_chat_cmd(SMTP_SESSION *, const char *,...); 546 extern DICT *smtp_chat_resp_filter; 547 extern SMTP_RESP *smtp_chat_resp(SMTP_SESSION *); 548 extern void smtp_chat_init(SMTP_SESSION *); 549 extern void smtp_chat_reset(SMTP_SESSION *); 550 extern void smtp_chat_notify(SMTP_SESSION *); 551 552 #define SMTP_RESP_FAKE(resp, _dsn) \ 553 ((resp)->code = 0, \ 554 (resp)->dsn = (_dsn), \ 555 (resp)->str = DSN_BY_LOCAL_MTA, \ 556 (resp)) 557 558 #define DSN_BY_LOCAL_MTA ((char *) 0) /* DSN issued by local MTA */ 559 560 #define SMTP_RESP_SET_DSN(resp, _dsn) do { \ 561 vstring_strcpy((resp)->dsn_buf, (_dsn)); \ 562 (resp)->dsn = STR((resp)->dsn_buf); \ 563 } while (0) 564 565 /* 566 * These operations implement a redundant mark-and-sweep algorithm that 567 * explicitly accounts for the fate of every recipient. The interface is 568 * documented in smtp_rcpt.c, which also implements the sweeping. The 569 * smtp_trouble.c module does most of the marking after failure. 570 * 571 * When a delivery fails or succeeds, take one of the following actions: 572 * 573 * - Mark the recipient as KEEP (deliver to alternate MTA) and do not update 574 * the delivery request status. 575 * 576 * - Mark the recipient as DROP (remove from delivery request), log whether 577 * delivery succeeded or failed, delete the recipient from the queue file 578 * and/or update defer or bounce logfiles, and update the delivery request 579 * status. 580 * 581 * At the end of a delivery attempt, all recipients must be marked one way or 582 * the other. Failure to do so will trigger a panic. 583 */ 584 #define SMTP_RCPT_STATE_KEEP 1 /* send to backup host */ 585 #define SMTP_RCPT_STATE_DROP 2 /* remove from request */ 586 #define SMTP_RCPT_INIT(state) do { \ 587 (state)->rcpt_drop = (state)->rcpt_keep = 0; \ 588 (state)->rcpt_left = state->request->rcpt_list.len; \ 589 } while (0) 590 591 #define SMTP_RCPT_DROP(state, rcpt) do { \ 592 (rcpt)->u.status = SMTP_RCPT_STATE_DROP; (state)->rcpt_drop++; \ 593 } while (0) 594 595 #define SMTP_RCPT_KEEP(state, rcpt) do { \ 596 (rcpt)->u.status = SMTP_RCPT_STATE_KEEP; (state)->rcpt_keep++; \ 597 } while (0) 598 599 #define SMTP_RCPT_ISMARKED(rcpt) ((rcpt)->u.status != 0) 600 601 #define SMTP_RCPT_LEFT(state) (state)->rcpt_left 602 603 #define SMTP_RCPT_MARK_COUNT(state) ((state)->rcpt_drop + (state)->rcpt_keep) 604 605 extern void smtp_rcpt_cleanup(SMTP_STATE *); 606 extern void smtp_rcpt_done(SMTP_STATE *, SMTP_RESP *, RECIPIENT *); 607 608 /* 609 * smtp_trouble.c 610 */ 611 #define SMTP_THROTTLE 1 612 #define SMTP_NOTHROTTLE 0 613 extern int smtp_sess_fail(SMTP_STATE *); 614 extern int PRINTFLIKE(5, 6) smtp_misc_fail(SMTP_STATE *, int, const char *, 615 SMTP_RESP *, const char *,...); 616 extern void PRINTFLIKE(5, 6) smtp_rcpt_fail(SMTP_STATE *, RECIPIENT *, 617 const char *, SMTP_RESP *, 618 const char *,...); 619 extern int smtp_stream_except(SMTP_STATE *, int, const char *); 620 621 #define smtp_site_fail(state, mta, resp, ...) \ 622 smtp_misc_fail((state), SMTP_THROTTLE, (mta), (resp), __VA_ARGS__) 623 #define smtp_mesg_fail(state, mta, resp, ...) \ 624 smtp_misc_fail((state), SMTP_NOTHROTTLE, (mta), (resp), __VA_ARGS__) 625 626 /* 627 * smtp_unalias.c 628 */ 629 extern const char *smtp_unalias_name(const char *); 630 extern VSTRING *smtp_unalias_addr(VSTRING *, const char *); 631 632 /* 633 * smtp_state.c 634 */ 635 extern SMTP_STATE *smtp_state_alloc(void); 636 extern void smtp_state_free(SMTP_STATE *); 637 638 /* 639 * smtp_map11.c 640 */ 641 extern int smtp_map11_external(VSTRING *, MAPS *, int); 642 extern int smtp_map11_tree(TOK822 *, MAPS *, int); 643 extern int smtp_map11_internal(VSTRING *, MAPS *, int); 644 645 /* 646 * smtp_key.c 647 */ 648 char *smtp_key_prefix(VSTRING *, const char *, SMTP_ITERATOR *, int); 649 650 #define SMTP_KEY_FLAG_SERVICE (1<<0) /* service name */ 651 #define SMTP_KEY_FLAG_SENDER (1<<1) /* sender address */ 652 #define SMTP_KEY_FLAG_REQ_NEXTHOP (1<<2) /* delivery request nexthop */ 653 #define SMTP_KEY_FLAG_CUR_NEXTHOP (1<<3) /* current nexthop */ 654 #define SMTP_KEY_FLAG_HOSTNAME (1<<4) /* remote host name */ 655 #define SMTP_KEY_FLAG_ADDR (1<<5) /* remote address */ 656 #define SMTP_KEY_FLAG_PORT (1<<6) /* remote port */ 657 #define SMTP_KEY_FLAG_TLS_LEVEL (1<<7) /* requested TLS level */ 658 659 #define SMTP_KEY_MASK_ALL \ 660 (SMTP_KEY_FLAG_SERVICE | SMTP_KEY_FLAG_SENDER | \ 661 SMTP_KEY_FLAG_REQ_NEXTHOP | \ 662 SMTP_KEY_FLAG_CUR_NEXTHOP | SMTP_KEY_FLAG_HOSTNAME | \ 663 SMTP_KEY_FLAG_ADDR | SMTP_KEY_FLAG_PORT | SMTP_KEY_FLAG_TLS_LEVEL) 664 665 /* 666 * Conditional lookup-key flags for cached connections that may be 667 * SASL-authenticated with a per-{sender, nexthop, or hostname} credential. 668 * Each bit corresponds to one type of smtp_sasl_password_file lookup key, 669 * and is turned on only when the corresponding main.cf parameter is turned 670 * on. 671 */ 672 #define COND_SASL_SMTP_KEY_FLAG_SENDER \ 673 ((var_smtp_sender_auth && *var_smtp_sasl_passwd) ? \ 674 SMTP_KEY_FLAG_SENDER : 0) 675 676 #define COND_SASL_SMTP_KEY_FLAG_CUR_NEXTHOP \ 677 (*var_smtp_sasl_passwd ? SMTP_KEY_FLAG_CUR_NEXTHOP : 0) 678 679 #ifdef USE_TLS 680 #define COND_TLS_SMTP_KEY_FLAG_CUR_NEXTHOP \ 681 (TLS_MUST_MATCH(state->tls->level) ? SMTP_KEY_FLAG_CUR_NEXTHOP : 0) 682 #else 683 #define COND_TLS_SMTP_KEY_FLAG_CUR_NEXTHOP \ 684 (0) 685 #endif 686 687 #define COND_SASL_SMTP_KEY_FLAG_HOSTNAME \ 688 (*var_smtp_sasl_passwd ? SMTP_KEY_FLAG_HOSTNAME : 0) 689 690 /* 691 * Connection-cache destination lookup key, based on the delivery request 692 * nexthop. The SENDER attribute is a proxy for sender-dependent SASL 693 * credentials (or absence thereof), and prevents false connection sharing 694 * when different SASL credentials may be required for different deliveries 695 * to the same domain and port. Likewise, the delivery request nexthop 696 * (REQ_NEXTHOP) prevents false sharing of TLS identities (the destination 697 * key links only to appropriate endpoint lookup keys). The SERVICE 698 * attribute is a proxy for all request-independent configuration details. 699 */ 700 #define SMTP_KEY_MASK_SCACHE_DEST_LABEL \ 701 (SMTP_KEY_FLAG_SERVICE | COND_SASL_SMTP_KEY_FLAG_SENDER \ 702 | SMTP_KEY_FLAG_REQ_NEXTHOP) 703 704 /* 705 * Connection-cache endpoint lookup key. The SENDER, CUR_NEXTHOP, HOSTNAME, 706 * PORT and TLS_LEVEL attributes are proxies for SASL credentials and TLS 707 * authentication (or absence thereof), and prevent false connection sharing 708 * when different SASL credentials or TLS identities may be required for 709 * different deliveries to the same IP address and port. The SERVICE 710 * attribute is a proxy for all request-independent configuration details. 711 */ 712 #define SMTP_KEY_MASK_SCACHE_ENDP_LABEL \ 713 (SMTP_KEY_FLAG_SERVICE | COND_SASL_SMTP_KEY_FLAG_SENDER \ 714 | COND_SASL_SMTP_KEY_FLAG_CUR_NEXTHOP \ 715 | COND_SASL_SMTP_KEY_FLAG_HOSTNAME \ 716 | COND_TLS_SMTP_KEY_FLAG_CUR_NEXTHOP | SMTP_KEY_FLAG_ADDR | \ 717 SMTP_KEY_FLAG_PORT | SMTP_KEY_FLAG_TLS_LEVEL) 718 719 /* 720 * Silly little macros. 721 */ 722 #define STR(s) vstring_str(s) 723 #define LEN(s) VSTRING_LEN(s) 724 725 extern int smtp_mode; 726 727 #define VAR_LMTP_SMTP(x) (smtp_mode ? VAR_SMTP_##x : VAR_LMTP_##x) 728 #define LMTP_SMTP_SUFFIX(x) (smtp_mode ? x##_SMTP : x##_LMTP) 729 730 /* 731 * Parsed command-line attributes. These do not change during the process 732 * lifetime. 733 */ 734 typedef struct { 735 int flags; /* from flags=, see below */ 736 } SMTP_CLI_ATTR; 737 738 #define SMTP_CLI_FLAG_DELIVERED_TO (1<<0) /* prepend Delivered-To: */ 739 #define SMTP_CLI_FLAG_ORIG_RCPT (1<<1) /* prepend X-Original-To: */ 740 #define SMTP_CLI_FLAG_RETURN_PATH (1<<2) /* prepend Return-Path: */ 741 #define SMTP_CLI_FLAG_FINAL_DELIVERY (1<<3) /* final, not relay */ 742 743 #define SMTP_CLI_MASK_ADD_HEADERS (SMTP_CLI_FLAG_DELIVERED_TO | \ 744 SMTP_CLI_FLAG_ORIG_RCPT | SMTP_CLI_FLAG_RETURN_PATH) 745 746 extern SMTP_CLI_ATTR smtp_cli_attr; 747 748 /* 749 * smtp_misc.c. 750 */ 751 extern void smtp_rewrite_generic_internal(VSTRING *, const char *); 752 extern void smtp_quote_822_address_flags(VSTRING *, const char *, int); 753 extern void smtp_quote_821_address(VSTRING *, const char *); 754 755 /* 756 * header_from_format support, for postmaster notifications. 757 */ 758 extern int smtp_hfrom_format; 759 760 /* LICENSE 761 /* .ad 762 /* .fi 763 /* The Secure Mailer license must be distributed with this software. 764 /* AUTHOR(S) 765 /* Wietse Venema 766 /* IBM T.J. Watson Research 767 /* P.O. Box 704 768 /* Yorktown Heights, NY 10598, USA 769 /* 770 /* Wietse Venema 771 /* Google, Inc. 772 /* 111 8th Avenue 773 /* New York, NY 10011, USA 774 /* 775 /* TLS support originally by: 776 /* Lutz Jaenicke 777 /* BTU Cottbus 778 /* Allgemeine Elektrotechnik 779 /* Universitaetsplatz 3-4 780 /* D-03044 Cottbus, Germany 781 /* 782 /* Victor Duchovni 783 /* Morgan Stanley 784 /*--*/ 785