1 /* 2 * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>. 3 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Simon Schubert <2@0x2c.org>. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "dfcompat.h" 37 38 #include <sys/param.h> 39 #include <sys/types.h> 40 #include <sys/queue.h> 41 #include <sys/stat.h> 42 #include <sys/time.h> 43 #include <sys/wait.h> 44 45 #include <dirent.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <inttypes.h> 50 #include <libgen.h> 51 #include <paths.h> 52 #include <pwd.h> 53 #include <signal.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <syslog.h> 59 #include <unistd.h> 60 61 #include "dma.h" 62 63 extern int yyparse(void); 64 extern FILE *yyin; 65 66 static void deliver(struct qitem *); 67 68 struct aliases aliases = LIST_HEAD_INITIALIZER(aliases); 69 struct strlist tmpfs = SLIST_HEAD_INITIALIZER(tmpfs); 70 struct authusers authusers = LIST_HEAD_INITIALIZER(authusers); 71 char username[USERNAME_SIZE]; 72 uid_t useruid; 73 const char *logident_base; 74 char errmsg[ERRMSG_SIZE]; 75 76 static int daemonize = 1; 77 static int doqueue = 0; 78 79 struct config config = { 80 .smarthost = NULL, 81 .port = 25, 82 .aliases = "/etc/aliases", 83 .spooldir = "/var/spool/dma", 84 .authpath = NULL, 85 .certfile = NULL, 86 .features = 0, 87 .mailname = NULL, 88 .masquerade_host = NULL, 89 .masquerade_user = NULL, 90 .fingerprint = NULL, 91 }; 92 93 94 static void 95 sighup_handler(int signo) 96 { 97 (void)signo; /* so that gcc doesn't complain */ 98 } 99 100 static char * 101 set_from(struct queue *queue, const char *osender) 102 { 103 const char *addr; 104 char *sender; 105 106 if (config.masquerade_user) { 107 addr = config.masquerade_user; 108 } else if (osender) { 109 addr = osender; 110 } else if (getenv("EMAIL") != NULL) { 111 addr = getenv("EMAIL"); 112 } else { 113 addr = username; 114 } 115 116 if (!strchr(addr, '@')) { 117 const char *from_host = hostname(); 118 119 if (config.masquerade_host) 120 from_host = config.masquerade_host; 121 122 if (asprintf(&sender, "%s@%s", addr, from_host) <= 0) 123 return (NULL); 124 } else { 125 sender = strdup(addr); 126 if (sender == NULL) 127 return (NULL); 128 } 129 130 if (strchr(sender, '\n') != NULL) { 131 errno = EINVAL; 132 return (NULL); 133 } 134 135 queue->sender = sender; 136 return (sender); 137 } 138 139 static int 140 read_aliases(void) 141 { 142 yyin = fopen(config.aliases, "r"); 143 if (yyin == NULL) { 144 /* 145 * Non-existing aliases file is not a fatal error 146 */ 147 if (errno == ENOENT) 148 return (0); 149 /* Other problems are. */ 150 return (-1); 151 } 152 if (yyparse()) 153 return (-1); /* fatal error, probably malloc() */ 154 fclose(yyin); 155 return (0); 156 } 157 158 static int 159 do_alias(struct queue *queue, const char *addr) 160 { 161 struct alias *al; 162 struct stritem *sit; 163 int aliased = 0; 164 165 LIST_FOREACH(al, &aliases, next) { 166 if (strcmp(al->alias, addr) != 0) 167 continue; 168 SLIST_FOREACH(sit, &al->dests, next) { 169 if (add_recp(queue, sit->str, EXPAND_ADDR) != 0) 170 return (-1); 171 } 172 aliased = 1; 173 } 174 175 return (aliased); 176 } 177 178 int 179 add_recp(struct queue *queue, const char *str, int expand) 180 { 181 struct qitem *it, *tit; 182 struct passwd *pw; 183 char *host; 184 int aliased = 0; 185 186 it = calloc(1, sizeof(*it)); 187 if (it == NULL) 188 return (-1); 189 it->addr = strdup(str); 190 if (it->addr == NULL) 191 return (-1); 192 193 it->sender = queue->sender; 194 host = strrchr(it->addr, '@'); 195 if (host != NULL && 196 (strcmp(host + 1, hostname()) == 0 || 197 strcmp(host + 1, "localhost") == 0)) { 198 *host = 0; 199 } 200 LIST_FOREACH(tit, &queue->queue, next) { 201 /* weed out duplicate dests */ 202 if (strcmp(tit->addr, it->addr) == 0) { 203 free(it->addr); 204 free(it); 205 return (0); 206 } 207 } 208 LIST_INSERT_HEAD(&queue->queue, it, next); 209 210 /** 211 * Do local delivery if there is no @. 212 * Do not do local delivery when NULLCLIENT is set. 213 */ 214 if (strrchr(it->addr, '@') == NULL && (config.features & NULLCLIENT) == 0) { 215 it->remote = 0; 216 if (expand) { 217 aliased = do_alias(queue, it->addr); 218 if (!aliased && expand == EXPAND_WILDCARD) 219 aliased = do_alias(queue, "*"); 220 if (aliased < 0) 221 return (-1); 222 if (aliased) { 223 LIST_REMOVE(it, next); 224 } else { 225 /* Local destination, check */ 226 pw = getpwnam(it->addr); 227 if (pw == NULL) 228 goto out; 229 /* XXX read .forward */ 230 endpwent(); 231 } 232 } 233 } else { 234 it->remote = 1; 235 } 236 237 return (0); 238 239 out: 240 free(it->addr); 241 free(it); 242 return (-1); 243 } 244 245 static struct qitem * 246 go_background(struct queue *queue) 247 { 248 struct sigaction sa; 249 struct qitem *it; 250 pid_t pid; 251 252 if (daemonize && daemon(0, 0) != 0) { 253 syslog(LOG_ERR, "can not daemonize: %m"); 254 exit(EX_OSERR); 255 } 256 daemonize = 0; 257 258 bzero(&sa, sizeof(sa)); 259 sa.sa_handler = SIG_IGN; 260 sigaction(SIGCHLD, &sa, NULL); 261 262 LIST_FOREACH(it, &queue->queue, next) { 263 /* No need to fork for the last dest */ 264 if (LIST_NEXT(it, next) == NULL) 265 goto retit; 266 267 pid = fork(); 268 switch (pid) { 269 case -1: 270 syslog(LOG_ERR, "can not fork: %m"); 271 exit(EX_OSERR); 272 break; 273 274 case 0: 275 /* 276 * Child: 277 * 278 * return and deliver mail 279 */ 280 retit: 281 /* 282 * If necessary, acquire the queue and * mail files. 283 * If this fails, we probably were raced by another 284 * process. It is okay to be raced if we're supposed 285 * to flush the queue. 286 */ 287 setlogident("%s", it->queueid); 288 switch (acquirespool(it)) { 289 case 0: 290 break; 291 case 1: 292 if (doqueue) 293 exit(EX_OK); 294 syslog(LOG_WARNING, "could not lock queue file"); 295 exit(EX_SOFTWARE); 296 default: 297 exit(EX_SOFTWARE); 298 } 299 dropspool(queue, it); 300 return (it); 301 302 default: 303 /* 304 * Parent: 305 * 306 * fork next child 307 */ 308 break; 309 } 310 } 311 312 syslog(LOG_CRIT, "reached dead code"); 313 exit(EX_SOFTWARE); 314 } 315 316 static void 317 deliver(struct qitem *it) 318 { 319 int error; 320 unsigned int backoff = MIN_RETRY, slept; 321 struct timeval now; 322 struct stat st; 323 324 snprintf(errmsg, sizeof(errmsg), "unknown bounce reason"); 325 326 retry: 327 syslog(LOG_INFO, "<%s> trying delivery", it->addr); 328 329 if (it->remote) 330 error = deliver_remote(it); 331 else 332 error = deliver_local(it); 333 334 switch (error) { 335 case 0: 336 syslog(LOG_INFO, "<%s> delivery successful", it->addr); 337 delqueue(it); 338 exit(EX_OK); 339 340 case 1: 341 if (stat(it->queuefn, &st) != 0) { 342 syslog(LOG_ERR, "lost queue file `%s'", it->queuefn); 343 exit(EX_SOFTWARE); 344 } 345 if (gettimeofday(&now, NULL) == 0 && 346 (now.tv_sec - st.st_mtim.tv_sec > MAX_TIMEOUT)) { 347 snprintf(errmsg, sizeof(errmsg), 348 "Could not deliver for the last %d seconds. Giving up.", 349 MAX_TIMEOUT); 350 goto bounce; 351 } 352 for (slept = 0; slept < backoff;) { 353 slept += SLEEP_TIMEOUT - sleep(SLEEP_TIMEOUT); 354 if (flushqueue_since(slept)) { 355 backoff = MIN_RETRY; 356 goto retry; 357 } 358 } 359 if (slept >= backoff) { 360 /* pick the next backoff between [1.5, 2.5) times backoff */ 361 backoff = backoff + backoff / 2 + random() % backoff; 362 if (backoff > MAX_RETRY) 363 backoff = MAX_RETRY; 364 } 365 goto retry; 366 367 case -1: 368 default: 369 break; 370 } 371 372 bounce: 373 bounce(it, errmsg); 374 /* NOTREACHED */ 375 } 376 377 void 378 run_queue(struct queue *queue) 379 { 380 struct qitem *it; 381 382 if (LIST_EMPTY(&queue->queue)) 383 return; 384 385 it = go_background(queue); 386 deliver(it); 387 /* NOTREACHED */ 388 } 389 390 static void 391 show_queue(struct queue *queue) 392 { 393 struct qitem *it; 394 int locked = 0; /* XXX */ 395 396 if (LIST_EMPTY(&queue->queue)) { 397 printf("Mail queue is empty\n"); 398 return; 399 } 400 401 LIST_FOREACH(it, &queue->queue, next) { 402 printf("ID\t: %s%s\n" 403 "From\t: %s\n" 404 "To\t: %s\n", 405 it->queueid, 406 locked ? "*" : "", 407 it->sender, it->addr); 408 409 if (LIST_NEXT(it, next) != NULL) 410 printf("--\n"); 411 } 412 } 413 414 /* 415 * TODO: 416 * 417 * - alias processing 418 * - use group permissions 419 * - proper sysexit codes 420 */ 421 422 int 423 main(int argc, char **argv) 424 { 425 struct sigaction act; 426 char *sender = NULL; 427 char *own_name = NULL; 428 struct queue queue; 429 int i, ch; 430 int nodot = 0, showq = 0, queue_only = 0, newaliases = 0; 431 int recp_from_header = 0; 432 433 set_username(); 434 435 /* 436 * We never run as root. If called by root, drop permissions 437 * to the mail user. 438 */ 439 if (geteuid() == 0 || getuid() == 0) { 440 struct passwd *pw; 441 442 errno = 0; 443 pw = getpwnam(DMA_ROOT_USER); 444 if (pw == NULL) { 445 if (errno == 0) 446 errx(EX_CONFIG, "user '%s' not found", DMA_ROOT_USER); 447 else 448 err(EX_OSERR, "cannot drop root privileges"); 449 } 450 451 if (setuid(pw->pw_uid) != 0) 452 err(EX_OSERR, "cannot drop root privileges"); 453 454 if (geteuid() == 0 || getuid() == 0) 455 errx(EX_OSERR, "cannot drop root privileges"); 456 } 457 458 atexit(deltmp); 459 init_random(); 460 461 bzero(&queue, sizeof(queue)); 462 LIST_INIT(&queue.queue); 463 464 own_name = basename(argv[0]); 465 466 if (strcmp(own_name, "mailq") == 0) { 467 argv++; argc--; 468 showq = 1; 469 if (argc != 0 && strcmp(argv[0], "-Ac") != 0) 470 errx(EX_USAGE, "invalid arguments"); 471 goto skipopts; 472 } else if (strcmp(own_name, "newaliases") == 0) { 473 newaliases = 1; 474 goto skipopts; 475 } else if (strcmp(own_name, "hoststat") == 0 || 476 strcmp(own_name, "purgestat") == 0) { 477 exit(EX_OK); 478 } 479 480 opterr = 0; 481 while ((ch = getopt(argc, argv, ":A:b:B:C:d:Df:F:h:iL:N:no:O:q:r:R:tUV:vX:")) != -1) { 482 switch (ch) { 483 case 'A': 484 /* -AX is being ignored, except for -A{c,m} */ 485 if (optarg[0] == 'c' || optarg[0] == 'm') { 486 break; 487 } 488 /* Else FALLTHROUGH */ 489 case 'b': 490 /* -bX is being ignored, except for -bp */ 491 if (optarg[0] == 'p') { 492 showq = 1; 493 break; 494 } else if (optarg[0] == 'q') { 495 queue_only = 1; 496 break; 497 } 498 /* Else FALLTHROUGH */ 499 case 'D': 500 daemonize = 0; 501 break; 502 case 'L': 503 logident_base = optarg; 504 break; 505 case 'f': 506 case 'r': 507 sender = optarg; 508 break; 509 510 case 't': 511 recp_from_header = 1; 512 break; 513 514 case 'o': 515 /* -oX is being ignored, except for -oi */ 516 if (optarg[0] != 'i') 517 break; 518 /* Else FALLTHROUGH */ 519 case 'i': 520 nodot = 1; 521 break; 522 523 case 'q': 524 /* Don't let getopt slup up other arguments */ 525 if (optarg && *optarg == '-') 526 optind--; 527 doqueue = 1; 528 break; 529 530 /* Ignored options */ 531 case 'B': 532 case 'C': 533 case 'd': 534 case 'F': 535 case 'h': 536 case 'N': 537 case 'n': 538 case 'O': 539 case 'R': 540 case 'U': 541 case 'V': 542 case 'v': 543 case 'X': 544 break; 545 546 case ':': 547 if (optopt == 'q') { 548 doqueue = 1; 549 break; 550 } 551 /* Else FALLTHROUGH */ 552 553 default: 554 fprintf(stderr, "invalid argument: `-%c'\n", optopt); 555 exit(EX_USAGE); 556 } 557 } 558 argc -= optind; 559 argv += optind; 560 opterr = 1; 561 562 if (argc != 0 && (showq || doqueue)) 563 errx(EX_USAGE, "sending mail and queue operations are mutually exclusive"); 564 565 if (showq + doqueue > 1) 566 errx(EX_USAGE, "conflicting queue operations"); 567 568 skipopts: 569 if (logident_base == NULL) 570 logident_base = "dma"; 571 setlogident(NULL); 572 573 act.sa_handler = sighup_handler; 574 act.sa_flags = 0; 575 sigemptyset(&act.sa_mask); 576 if (sigaction(SIGHUP, &act, NULL) != 0) 577 syslog(LOG_WARNING, "can not set signal handler: %m"); 578 579 parse_conf(CONF_PATH "/dma.conf"); 580 581 if (config.authpath != NULL) 582 parse_authfile(config.authpath); 583 584 if (showq) { 585 if (load_queue(&queue) < 0) 586 errlog(EX_NOINPUT, "can not load queue"); 587 show_queue(&queue); 588 return (0); 589 } 590 591 if (doqueue) { 592 flushqueue_signal(); 593 if (load_queue(&queue) < 0) 594 errlog(EX_NOINPUT, "can not load queue"); 595 run_queue(&queue); 596 return (0); 597 } 598 599 if (read_aliases() != 0) 600 errlog(EX_SOFTWARE, "could not parse aliases file `%s'", config.aliases); 601 602 if (newaliases) 603 return(0); 604 605 if ((sender = set_from(&queue, sender)) == NULL) 606 errlog(EX_SOFTWARE, NULL); 607 608 if (newspoolf(&queue) != 0) 609 errlog(EX_CANTCREAT, "can not create temp file in `%s'", config.spooldir); 610 611 setlogident("%s", queue.id); 612 613 for (i = 0; i < argc; i++) { 614 if (add_recp(&queue, argv[i], EXPAND_WILDCARD) != 0) 615 errlogx(EX_DATAERR, "invalid recipient `%s'", argv[i]); 616 } 617 618 if (LIST_EMPTY(&queue.queue) && !recp_from_header) 619 errlogx(EX_NOINPUT, "no recipients"); 620 621 if (readmail(&queue, nodot, recp_from_header) != 0) 622 errlog(EX_NOINPUT, "can not read mail"); 623 624 if (LIST_EMPTY(&queue.queue)) 625 errlogx(EX_NOINPUT, "no recipients"); 626 627 if (linkspool(&queue) != 0) 628 errlog(EX_CANTCREAT, "can not create spools"); 629 630 /* From here on the mail is safe. */ 631 632 if (config.features & DEFER || queue_only) 633 return (0); 634 635 run_queue(&queue); 636 637 /* NOTREACHED */ 638 return (0); 639 } 640