1 /* 2 * Copyright (c) 1983 Eric P. Allman 3 * Copyright (c) 1988 Regents of the University of California. 4 * All rights reserved. 5 * 6 * %sccs.include.redist.c% 7 */ 8 9 #ifndef lint 10 #ifdef USERDB 11 static char sccsid [] = "@(#)udb.c 6.7 (Berkeley) 02/18/93 (with USERDB)"; 12 #else 13 static char sccsid [] = "@(#)udb.c 6.7 (Berkeley) 02/18/93 (without USERDB)"; 14 #endif 15 #endif 16 17 #include "sendmail.h" 18 19 #ifdef USERDB 20 21 #include <sys/time.h> 22 #include <errno.h> 23 #include <fcntl.h> 24 #include <netdb.h> 25 #include <db.h> 26 27 /* 28 ** UDB.C -- interface between sendmail and Berkeley User Data Base. 29 ** 30 ** This depends on the 4.4BSD db package. 31 */ 32 33 34 struct udbent 35 { 36 char *udb_spec; /* string version of spec */ 37 int udb_type; /* type of entry */ 38 char *udb_default; /* default host for outgoing mail */ 39 union 40 { 41 /* type UE_REMOTE -- do remote call for lookup */ 42 struct 43 { 44 struct sockaddr_in _udb_addr; /* address */ 45 int _udb_timeout; /* timeout */ 46 } udb_remote; 47 #define udb_addr udb_u.udb_remote._udb_addr 48 #define udb_timeout udb_u.udb_remote._udb_timeout 49 50 /* type UE_FORWARD -- forward message to remote */ 51 struct 52 { 53 char *_udb_fwdhost; /* name of forward host */ 54 } udb_forward; 55 #define udb_fwdhost udb_u.udb_forward._udb_fwdhost 56 57 /* type UE_FETCH -- lookup in local database */ 58 struct 59 { 60 char *_udb_dbname; /* pathname of database */ 61 DB *_udb_dbp; /* open database ptr */ 62 } udb_lookup; 63 #define udb_dbname udb_u.udb_lookup._udb_dbname 64 #define udb_dbp udb_u.udb_lookup._udb_dbp 65 } udb_u; 66 }; 67 68 #define UDB_EOLIST 0 /* end of list */ 69 #define UDB_SKIP 1 /* skip this entry */ 70 #define UDB_REMOTE 2 /* look up in remote database */ 71 #define UDB_DBFETCH 3 /* look up in local database */ 72 #define UDB_FORWARD 4 /* forward to remote host */ 73 74 #define MAXUDBENT 10 /* maximum number of UDB entries */ 75 76 77 struct option 78 { 79 char *name; 80 char *val; 81 }; 82 /* 83 ** UDBEXPAND -- look up user in database and expand 84 ** 85 ** Parameters: 86 ** a -- address to expand. 87 ** sendq -- pointer to head of sendq to put the expansions in. 88 ** 89 ** Returns: 90 ** EX_TEMPFAIL -- if something "odd" happened -- probably due 91 ** to accessing a file on an NFS server that is down. 92 ** EX_OK -- otherwise. 93 ** 94 ** Side Effects: 95 ** Modifies sendq. 96 */ 97 98 int UdbPort = 1616; 99 int UdbTimeout = 10; 100 101 struct udbent UdbEnts[MAXUDBENT + 1]; 102 int UdbSock = -1; 103 bool UdbInitialized = FALSE; 104 105 int 106 udbexpand(a, sendq, e) 107 register ADDRESS *a; 108 ADDRESS **sendq; 109 register ENVELOPE *e; 110 { 111 int i; 112 register char *p; 113 DBT key; 114 DBT info; 115 bool breakout; 116 register struct udbent *up; 117 int keylen; 118 char keybuf[MAXKEY]; 119 char buf[BUFSIZ]; 120 121 if (tTd(28, 1)) 122 printf("expand(%s)\n", a->q_paddr); 123 124 /* make certain we are supposed to send to this address */ 125 if (bitset(QDONTSEND, a->q_flags)) 126 return EX_OK; 127 e->e_to = a->q_paddr; 128 129 /* on first call, locate the database */ 130 if (!UdbInitialized) 131 { 132 extern int _udbx_init(); 133 134 if (_udbx_init() == EX_TEMPFAIL) 135 return EX_TEMPFAIL; 136 } 137 138 /* short circuit the process if no chance of a match */ 139 if (UdbSpec == NULL || UdbSpec[0] == '\0') 140 return EX_OK; 141 142 /* if name is too long, assume it won't match */ 143 if (strlen(a->q_user) > sizeof keybuf - 12) 144 return EX_OK; 145 146 /* if name begins with a colon, it indicates our metadata */ 147 if (a->q_user[0] == ':') 148 return EX_OK; 149 150 /* build actual database key */ 151 (void) strcpy(keybuf, a->q_user); 152 (void) strcat(keybuf, ":maildrop"); 153 keylen = strlen(keybuf); 154 155 breakout = FALSE; 156 for (up = UdbEnts; !breakout; up++) 157 { 158 char *user; 159 160 /* 161 ** Select action based on entry type. 162 ** 163 ** On dropping out of this switch, "class" should 164 ** explain the type of the data, and "user" should 165 ** contain the user information. 166 */ 167 168 switch (up->udb_type) 169 { 170 case UDB_DBFETCH: 171 key.data = keybuf; 172 key.size = keylen; 173 i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_CURSOR); 174 if (i > 0 || info.size <= 0) 175 { 176 if (tTd(28, 2)) 177 printf("expand: no match on %s\n", keybuf); 178 continue; 179 } 180 181 while (i == 0 && key.size == keylen && 182 bcmp(key.data, keybuf, keylen) == 0) 183 { 184 breakout = TRUE; 185 if (info.size < sizeof buf) 186 user = buf; 187 else 188 user = xalloc(info.size + 1); 189 bcopy(info.data, user, info.size); 190 user[info.size] = '\0'; 191 192 message(Arpa_Info, "expanded to %s", user); 193 #ifdef LOG 194 if (LogLevel >= 10) 195 syslog(LOG_INFO, "%s: expand %s => %s", 196 e->e_id, e->e_to, user); 197 #endif 198 AliasLevel++; 199 sendtolist(user, a, sendq, e); 200 AliasLevel--; 201 202 if (user != buf) 203 free(user); 204 205 /* get the next record */ 206 i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_NEXT); 207 } 208 if (i < 0) 209 { 210 syserr("udbexpand: db-get %.*s stat %d", 211 key.size, key.data, i); 212 return EX_TEMPFAIL; 213 } 214 break; 215 216 case UDB_REMOTE: 217 /* not yet implemented */ 218 continue; 219 220 case UDB_FORWARD: 221 i = strlen(up->udb_fwdhost) + strlen(a->q_user) + 1; 222 if (i < sizeof buf) 223 user = buf; 224 else 225 user = xalloc(i + 1); 226 (void) sprintf(user, "%s@%s", a->q_user, up->udb_fwdhost); 227 message(Arpa_Info, "expanded to %s", user); 228 AliasLevel++; 229 sendtolist(user, a, sendq, e); 230 AliasLevel--; 231 if (user != buf) 232 free(user); 233 breakout = TRUE; 234 break; 235 236 case UDB_EOLIST: 237 breakout = TRUE; 238 continue; 239 240 default: 241 /* unknown entry type */ 242 continue; 243 } 244 } 245 return EX_OK; 246 } 247 /* 248 ** UDBSENDER -- return canonical external name of sender, given local name 249 ** 250 ** Parameters: 251 ** sender -- the name of the sender on the local machine. 252 ** 253 ** Returns: 254 ** The external name for this sender, if derivable from the 255 ** database. 256 ** NULL -- if nothing is changed from the database. 257 ** 258 ** Side Effects: 259 ** none. 260 */ 261 262 char * 263 udbsender(sender) 264 char *sender; 265 { 266 register char *p; 267 register struct udbent *up; 268 int i; 269 int keylen; 270 DBT key, info; 271 char keybuf[MAXKEY]; 272 273 if (tTd(28, 1)) 274 printf("udbsender(%s)\n", sender); 275 276 if (!UdbInitialized) 277 { 278 if (_udbx_init() == EX_TEMPFAIL) 279 return NULL; 280 } 281 282 /* short circuit if no spec */ 283 if (UdbSpec == NULL || UdbSpec[0] == '\0') 284 return NULL; 285 286 /* long names can never match and are a pain to deal with */ 287 if (strlen(sender) > sizeof keybuf - 12) 288 return NULL; 289 290 /* names beginning with colons indicate metadata */ 291 if (sender[0] == ':') 292 return NULL; 293 294 /* build database key */ 295 (void) strcpy(keybuf, sender); 296 (void) strcat(keybuf, ":mailname"); 297 keylen = strlen(keybuf); 298 299 for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++) 300 { 301 /* 302 ** Select action based on entry type. 303 */ 304 305 switch (up->udb_type) 306 { 307 case UDB_DBFETCH: 308 key.data = keybuf; 309 key.size = keylen; 310 i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0); 311 if (i != 0 || info.size <= 0) 312 { 313 if (tTd(28, 2)) 314 printf("udbsender: no match on %s\n", 315 keybuf); 316 continue; 317 } 318 319 p = xalloc(info.size + 1); 320 bcopy(info.data, p, info.size); 321 p[info.size] = '\0'; 322 if (tTd(28, 1)) 323 printf("udbsender ==> %s\n", p); 324 return p; 325 } 326 } 327 328 /* 329 ** Nothing yet. Search again for a default case. But only 330 ** use it if we also have a forward (:maildrop) pointer already 331 ** in the database. 332 */ 333 334 /* build database key */ 335 (void) strcpy(keybuf, sender); 336 (void) strcat(keybuf, ":maildrop"); 337 keylen = strlen(keybuf); 338 339 for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++) 340 { 341 switch (up->udb_type) 342 { 343 case UDB_DBFETCH: 344 /* get the default case for this database */ 345 if (up->udb_default == NULL) 346 { 347 key.data = ":default:mailname"; 348 key.size = strlen(key.data); 349 i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0); 350 if (i != 0 || info.size <= 0) 351 { 352 /* no default case */ 353 up->udb_default = ""; 354 continue; 355 } 356 357 /* save the default case */ 358 up->udb_default = xalloc(info.size + 1); 359 bcopy(info.data, up->udb_default, info.size); 360 up->udb_default[info.size] = '\0'; 361 } 362 else if (up->udb_default[0] == '\0') 363 continue; 364 365 /* we have a default case -- verify user:maildrop */ 366 key.data = keybuf; 367 key.size = keylen; 368 i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0); 369 if (i != 0 || info.size <= 0) 370 { 371 /* nope -- no aliasing for this user */ 372 continue; 373 } 374 375 /* they exist -- build the actual address */ 376 p = xalloc(strlen(sender) + strlen(up->udb_default) + 2); 377 (void) strcpy(p, sender); 378 (void) strcat(p, "@"); 379 (void) strcat(p, up->udb_default); 380 if (tTd(28, 1)) 381 printf("udbsender ==> %s\n", p); 382 return p; 383 } 384 } 385 386 /* still nothing.... too bad */ 387 return NULL; 388 } 389 /* 390 ** _UDBX_INIT -- parse the UDB specification, opening any valid entries. 391 ** 392 ** Parameters: 393 ** none. 394 ** 395 ** Returns: 396 ** EX_TEMPFAIL -- if it appeared it couldn't get hold of a 397 ** database due to a host being down or some similar 398 ** (recoverable) situation. 399 ** EX_OK -- otherwise. 400 ** 401 ** Side Effects: 402 ** Fills in the UdbEnts structure from UdbSpec. 403 */ 404 405 #define MAXUDBOPTS 27 406 407 int 408 _udbx_init() 409 { 410 register char *p; 411 int i; 412 register struct udbent *up; 413 char buf[BUFSIZ]; 414 415 if (UdbInitialized) 416 return EX_OK; 417 418 # ifdef UDB_DEFAULT_SPEC 419 if (UdbSpec == NULL) 420 UdbSpec = UDB_DEFAULT_SPEC; 421 # endif 422 423 p = UdbSpec; 424 up = UdbEnts; 425 while (p != NULL) 426 { 427 char *spec; 428 auto int rcode; 429 int nopts; 430 int nmx; 431 register struct hostent *h; 432 char *mxhosts[MAXMXHOSTS + 1]; 433 struct option opts[MAXUDBOPTS + 1]; 434 435 while (*p == ' ' || *p == '\t' || *p == ',') 436 p++; 437 if (*p == '\0') 438 break; 439 spec = p; 440 p = strchr(p, ','); 441 if (p != NULL) 442 *p++ = '\0'; 443 444 /* extract options */ 445 nopts = _udb_parsespec(spec, opts, MAXUDBOPTS); 446 447 /* 448 ** Decode database specification. 449 ** 450 ** In the sendmail tradition, the leading character 451 ** defines the semantics of the rest of the entry. 452 ** 453 ** +hostname -- send a datagram to the udb server 454 ** on host "hostname" asking for the 455 ** home mail server for this user. 456 ** *hostname -- similar to +hostname, except that the 457 ** hostname is searched as an MX record; 458 ** resulting hosts are searched as for 459 ** +mxhostname. If no MX host is found, 460 ** this is the same as +hostname. 461 ** @hostname -- forward email to the indicated host. 462 ** This should be the last in the list, 463 ** since it always matches the input. 464 ** /dbname -- search the named database on the local 465 ** host using the Berkeley db package. 466 */ 467 468 switch (*spec) 469 { 470 case '+': /* search remote database */ 471 case '*': /* search remote database (expand MX) */ 472 if (*spec == '*') 473 { 474 #ifdef NAMED_BIND 475 nmx = getmxrr(spec + 1, mxhosts, "", &rcode); 476 #else 477 mxhosts[0] = spec + 1; 478 nmx = 1; 479 rcode = 0; 480 #endif 481 if (tTd(28, 16)) 482 { 483 int i; 484 485 printf("getmxrr(%s): %d", spec + 1, nmx); 486 for (i = 0; i <= nmx; i++) 487 printf(" %s", mxhosts[i]); 488 printf("\n"); 489 } 490 } 491 else 492 { 493 nmx = 1; 494 mxhosts[0] = spec + 1; 495 } 496 497 for (i = 0; i < nmx; i++) 498 { 499 h = gethostbyname(mxhosts[i]); 500 if (h == NULL) 501 continue; 502 up->udb_type = UDB_REMOTE; 503 up->udb_addr.sin_family = h->h_addrtype; 504 bcopy(h->h_addr_list[0], 505 (char *) &up->udb_addr.sin_addr, 506 h->h_length); 507 up->udb_addr.sin_port = UdbPort; 508 up->udb_timeout = UdbTimeout; 509 up++; 510 } 511 512 /* set up a datagram socket */ 513 if (UdbSock < 0) 514 { 515 UdbSock = socket(AF_INET, SOCK_DGRAM, 0); 516 (void) fcntl(UdbSock, F_SETFD, 1); 517 } 518 break; 519 520 case '@': /* forward to remote host */ 521 up->udb_type = UDB_FORWARD; 522 up->udb_fwdhost = spec + 1; 523 up++; 524 break; 525 526 case '/': /* look up remote name */ 527 up->udb_dbname = spec; 528 errno = 0; 529 up->udb_dbp = dbopen(spec, O_RDONLY, 0644, DB_BTREE, NULL); 530 if (up->udb_dbp == NULL) 531 { 532 if (errno != ENOENT && errno != EACCES) 533 { 534 up->udb_type = UDB_EOLIST; 535 goto tempfail; 536 } 537 break; 538 } 539 up->udb_type = UDB_DBFETCH; 540 up++; 541 break; 542 } 543 } 544 up->udb_type = UDB_EOLIST; 545 546 if (tTd(28, 4)) 547 { 548 for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++) 549 { 550 switch (up->udb_type) 551 { 552 case UDB_REMOTE: 553 printf("REMOTE: addr %s, timeo %d\n", 554 inet_ntoa(up->udb_addr.sin_addr), 555 up->udb_timeout); 556 break; 557 558 case UDB_DBFETCH: 559 printf("FETCH: file %s\n", 560 up->udb_dbname); 561 break; 562 563 case UDB_FORWARD: 564 printf("FORWARD: host %s\n", 565 up->udb_fwdhost); 566 break; 567 568 default: 569 printf("UNKNOWN\n"); 570 break; 571 } 572 } 573 } 574 575 UdbInitialized = TRUE; 576 errno = 0; 577 return EX_OK; 578 579 /* 580 ** On temporary failure, back out anything we've already done 581 */ 582 583 tempfail: 584 for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++) 585 { 586 if (up->udb_type == UDB_DBFETCH) 587 { 588 (*up->udb_dbp->close)(up->udb_dbp); 589 } 590 } 591 return EX_TEMPFAIL; 592 } 593 594 int 595 _udb_parsespec(udbspec, opt, maxopts) 596 char *udbspec; 597 struct option opt[]; 598 int maxopts; 599 { 600 register char *spec; 601 register char *spec_end; 602 register int optnum; 603 604 spec_end = strchr(udbspec, ':'); 605 for (optnum = 0; optnum < maxopts && (spec = spec_end) != NULL; optnum++) 606 { 607 register char *p; 608 609 while (isascii(*spec) && isspace(*spec)) 610 spec++; 611 spec_end = strchr(spec, ':'); 612 if (spec_end != NULL) 613 *spec_end++ = '\0'; 614 615 opt[optnum].name = spec; 616 opt[optnum].val = NULL; 617 p = strchr(spec, '='); 618 if (p != NULL) 619 opt[optnum].val = ++p; 620 } 621 return optnum; 622 } 623 624 #else /* not USERDB */ 625 626 int 627 udbexpand(a, sendq, e) 628 ADDRESS *a; 629 ADDRESS **sendq; 630 ENVELOPE *e; 631 { 632 return EX_OK; 633 } 634 635 #endif /* USERDB */ 636