dma.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/queue.h>
  37 #include <sys/stat.h>
  38 #include <sys/types.h>
  39 #include <sys/wait.h>
  40
  41 #include <dirent.h>
  42 #include <err.h>
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <inttypes.h>
  46 #include <paths.h>
  47 #include <pwd.h>
  48 #include <signal.h>
  49 #include <stdarg.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <syslog.h>
  54 #include <unistd.h>
  55
  56 #include "dma.h"
  57
  58
  59
  60 static void deliver(struct qitem *);
  61
  62 struct aliases aliases = LIST_HEAD_INITIALIZER(aliases);
  63 struct strlist tmpfs = SLIST_HEAD_INITIALIZER(tmpfs);
  64 struct virtusers virtusers = LIST_HEAD_INITIALIZER(virtusers);
  65 struct authusers authusers = LIST_HEAD_INITIALIZER(authusers);
  66 struct config *config;
  67 const char *username;
  68 const char *logident_base;
  69
  70 static int daemonize = 1;
  71
  72 static char *
  73 set_from(struct queue *queue, const char *osender)
  74 {
  75         struct virtuser *v;
  76         char *sender;
  77
  78         if ((config->features & VIRTUAL) != 0) {
  79                 SLIST_FOREACH(v, &virtusers, next) {
  80                         if (strcmp(v->login, username) == 0) {
  81                                 sender = strdup(v->address);
  82                                 if (sender == NULL)
  83                                         return(NULL);
  84                                 goto out;
  85                         }
  86                 }
  87         }
  88
  89         if (osender) {
  90                 sender = strdup(osender);
  91                 if (sender == NULL)
  92                         return (NULL);
  93         } else {
  94                 if (asprintf(&sender, "%s@%s", username, hostname()) <= 0)
  95                         return (NULL);
  96         }
  97
  98         if (strchr(sender, '\n') != NULL) {
  99                 errno = EINVAL;
 100                 return (NULL);
 101         }
 102
 103 out:
 104         queue->sender = sender;
 105         return (sender);
 106 }
 107
 108 static int
 109 read_aliases(void)
 110 {
 111         yyin = fopen(config->aliases, "r");
 112         if (yyin == NULL)
 113                 return (0);     /* not fatal */
 114         if (yyparse())
 115                 return (-1);    /* fatal error, probably malloc() */
 116         fclose(yyin);
 117         return (0);
 118 }
 119
 120 int
 121 add_recp(struct queue *queue, const char *str, int expand)
 122 {
 123         struct qitem *it, *tit;
 124         struct stritem *sit;
 125         struct alias *al;
 126         struct passwd *pw;
 127         char *host;
 128         int aliased = 0;
 129
 130         it = calloc(1, sizeof(*it));
 131         if (it == NULL)
 132                 return (-1);
 133         it->addr = strdup(str);
 134         if (it->addr == NULL)
 135                 return (-1);
 136
 137         it->sender = queue->sender;
 138         host = strrchr(it->addr, '@');
 139         if (host != NULL &&
 140             (strcmp(host + 1, hostname()) == 0 ||
 141              strcmp(host + 1, "localhost") == 0)) {
 142                 *host = 0;
 143         }
 144         LIST_FOREACH(tit, &queue->queue, next) {
 145                 /* weed out duplicate dests */
 146                 if (strcmp(tit->addr, it->addr) == 0) {
 147                         free(it->addr);
 148                         free(it);
 149                         return (0);
 150                 }
 151         }
 152         LIST_INSERT_HEAD(&queue->queue, it, next);
 153         if (strrchr(it->addr, '@') == NULL) {
 154                 it->remote = 0;
 155                 if (expand) {
 156                         LIST_FOREACH(al, &aliases, next) {
 157                                 if (strcmp(al->alias, it->addr) != 0)
 158                                         continue;
 159                                 SLIST_FOREACH(sit, &al->dests, next) {
 160                                         if (add_recp(queue, sit->str, 1) != 0)
 161                                                 return (-1);
 162                                 }
 163                                 aliased = 1;
 164                         }
 165                         if (aliased) {
 166                                 LIST_REMOVE(it, next);
 167                         } else {
 168                                 /* Local destination, check */
 169                                 pw = getpwnam(it->addr);
 170                                 if (pw == NULL)
 171                                         goto out;
 172                                 /* XXX read .forward */
 173                                 endpwent();
 174                         }
 175                 }
 176         } else {
 177                 it->remote = 1;
 178         }
 179
 180         return (0);
 181
 182 out:
 183         free(it->addr);
 184         free(it);
 185         return (-1);
 186 }
 187
 188 static struct qitem *
 189 go_background(struct queue *queue)
 190 {
 191         struct sigaction sa;
 192         struct qitem *it;
 193         pid_t pid;
 194
 195         if (daemonize && daemon(0, 0) != 0) {
 196                 syslog(LOG_ERR, "can not daemonize: %m");
 197                 exit(1);
 198         }
 199         daemonize = 0;
 200
 201         bzero(&sa, sizeof(sa));
 202         sa.sa_flags = SA_NOCLDWAIT;
 203         sa.sa_handler = SIG_IGN;
 204         sigaction(SIGCHLD, &sa, NULL);
 205
 206         LIST_FOREACH(it, &queue->queue, next) {
 207                 /* No need to fork for the last dest */
 208                 if (LIST_NEXT(it, next) == NULL)
 209                         goto retit;
 210
 211                 pid = fork();
 212                 switch (pid) {
 213                 case -1:
 214                         syslog(LOG_ERR, "can not fork: %m");
 215                         exit(1);
 216                         break;
 217
 218                 case 0:
 219                         /*
 220                          * Child:
 221                          *
 222                          * return and deliver mail
 223                          */
 224 retit:
 225                         /*
 226                          * If necessary, aquire the queue and * mail files.
 227                          * If this fails, we probably were raced by another
 228                          * process.
 229                          */
 230                         setlogident("%s", it->queueid);
 231                         if (aquirespool(it) < 0)
 232                                 exit(1);
 233                         dropspool(queue, it);
 234                         return (it);
 235
 236                 default:
 237                         /*
 238                          * Parent:
 239                          *
 240                          * fork next child
 241                          */
 242                         break;
 243                 }
 244         }
 245
 246         syslog(LOG_CRIT, "reached dead code");
 247         exit(1);
 248 }
 249
 250 static void
 251 deliver(struct qitem *it)
 252 {
 253         int error;
 254         unsigned int backoff = MIN_RETRY;
 255         const char *errmsg = "unknown bounce reason";
 256         struct timeval now;
 257         struct stat st;
 258
 259 retry:
 260         syslog(LOG_INFO, "trying delivery");
 261
 262         if (it->remote)
 263                 error = deliver_remote(it, &errmsg);
 264         else
 265                 error = deliver_local(it, &errmsg);
 266
 267         switch (error) {
 268         case 0:
 269                 delqueue(it);
 270                 syslog(LOG_INFO, "delivery successful");
 271                 exit(0);
 272
 273         case 1:
 274                 if (stat(it->queuefn, &st) != 0) {
 275                         syslog(LOG_ERR, "lost queue file `%s'", it->queuefn);
 276                         exit(1);
 277                 }
 278                 if (gettimeofday(&now, NULL) == 0 &&
 279                     (now.tv_sec - st.st_mtimespec.tv_sec > MAX_TIMEOUT)) {
 280                         asprintf(__DECONST(void *, &errmsg),
 281                                  "Could not deliver for the last %d seconds. Giving up.",
 282                                  MAX_TIMEOUT);
 283                         goto bounce;
 284                 }
 285                 sleep(backoff);
 286                 backoff *= 2;
 287                 if (backoff > MAX_RETRY)
 288                         backoff = MAX_RETRY;
 289                 goto retry;
 290
 291         case -1:
 292         default:
 293                 break;
 294         }
 295
 296 bounce:
 297         bounce(it, errmsg);
 298         /* NOTREACHED */
 299 }
 300
 301 void
 302 run_queue(struct queue *queue)
 303 {
 304         struct qitem *it;
 305
 306         if (LIST_EMPTY(&queue->queue))
 307                 return;
 308
 309         it = go_background(queue);
 310         deliver(it);
 311         /* NOTREACHED */
 312 }
 313
 314 static void
 315 show_queue(struct queue *queue)
 316 {
 317         struct qitem *it;
 318         int locked = 0; /* XXX */
 319
 320         if (LIST_EMPTY(&queue->queue)) {
 321                 printf("Mail queue is empty\n");
 322                 return;
 323         }
 324
 325         LIST_FOREACH(it, &queue->queue, next) {
 326                 printf("ID\t: %s%s\n"
 327                        "From\t: %s\n"
 328                        "To\t: %s\n"
 329                        "--\n",
 330                        it->queueid,
 331                        locked ? "*" : "",
 332                        it->sender, it->addr);
 333         }
 334 }
 335
 336 /*
 337  * TODO:
 338  *
 339  * - alias processing
 340  * - use group permissions
 341  * - proper sysexit codes
 342  */
 343
 344 int
 345 main(int argc, char **argv)
 346 {
 347         char *sender = NULL;
 348         struct queue queue;
 349         int i, ch;
 350         int nodot = 0, doqueue = 0, showq = 0, queue_only = 0;
 351
 352         atexit(deltmp);
 353
 354         bzero(&queue, sizeof(queue));
 355         LIST_INIT(&queue.queue);
 356
 357         if (strcmp(argv[0], "mailq") == 0) {
 358                 argv++; argc--;
 359                 showq = 1;
 360                 if (argc != 0)
 361                         errx(1, "invalid arguments");
 362                 goto skipopts;
 363         }
 364
 365         opterr = 0;
 366         while ((ch = getopt(argc, argv, ":A:b:B:C:d:Df:F:h:iL:N:no:O:q:r:R:UV:vX:")) != -1) {
 367                 switch (ch) {
 368                 case 'A':
 369                         /* -AX is being ignored, except for -A{c,m} */
 370                         if (optarg[0] == 'c' || optarg[0] == 'm') {
 371                                 break;
 372                         }
 373                         /* else FALLTRHOUGH */
 374                 case 'b':
 375                         /* -bX is being ignored, except for -bp */
 376                         if (optarg[0] == 'p') {
 377                                 showq = 1;
 378                                 break;
 379                         } else if (optarg[0] == 'q') {
 380                                 queue_only = 1;
 381                                 break;
 382                         }
 383                         /* else FALLTRHOUGH */
 384                 case 'D':
 385                         daemonize = 0;
 386                         break;
 387                 case 'L':
 388                         logident_base = optarg;
 389                         break;
 390                 case 'f':
 391                 case 'r':
 392                         sender = optarg;
 393                         break;
 394
 395                 case 'o':
 396                         /* -oX is being ignored, except for -oi */
 397                         if (optarg[0] != 'i')
 398                                 break;
 399                         /* else FALLTRHOUGH */
 400                 case 'O':
 401                         break;
 402                 case 'i':
 403                         nodot = 1;
 404                         break;
 405
 406                 case 'q':
 407                         doqueue = 1;
 408                         break;
 409
 410                 /* Ignored options */
 411                 case 'B':
 412                 case 'C':
 413                 case 'd':
 414                 case 'F':
 415                 case 'h':
 416                 case 'N':
 417                 case 'n':
 418                 case 'R':
 419                 case 'U':
 420                 case 'V':
 421                 case 'v':
 422                 case 'X':
 423                         break;
 424
 425                 case ':':
 426                         if (optopt == 'q') {
 427                                 doqueue = 1;
 428                                 break;
 429                         }
 430                         /* FALLTHROUGH */
 431
 432                 default:
 433                         fprintf(stderr, "invalid argument: `-%c'\n", optopt);
 434                         exit(1);
 435                 }
 436         }
 437         argc -= optind;
 438         argv += optind;
 439         opterr = 1;
 440
 441         if (argc != 0 && (showq || doqueue))
 442                 errx(1, "sending mail and queue operations are mutually exclusive");
 443
 444         if (showq + doqueue > 1)
 445                 errx(1, "conflicting queue operations");
 446
 447 skipopts:
 448         if (logident_base == NULL)
 449                 logident_base = "dma";
 450         setlogident(NULL);
 451         set_username();
 452
 453         /* XXX fork root here */
 454
 455         config = calloc(1, sizeof(*config));
 456         if (config == NULL)
 457                 errlog(1, NULL);
 458
 459         if (parse_conf(CONF_PATH) < 0) {
 460                 free(config);
 461                 errlog(1, "can not read config file");
 462         }
 463
 464         if (config->features & VIRTUAL)
 465                 if (parse_virtuser(config->virtualpath) < 0)
 466                         errlog(1, "can not read virtual user file `%s'",
 467                                 config->virtualpath);
 468
 469         if (parse_authfile(config->authpath) < 0)
 470                 errlog(1, "can not read SMTP authentication file");
 471
 472         if (showq) {
 473                 if (load_queue(&queue) < 0)
 474                         errlog(1, "can not load queue");
 475                 show_queue(&queue);
 476                 return (0);
 477         }
 478
 479         if (doqueue) {
 480                 if (load_queue(&queue) < 0)
 481                         errlog(1, "can not load queue");
 482                 run_queue(&queue);
 483                 return (0);
 484         }
 485
 486         if (read_aliases() != 0)
 487                 errlog(1, "can not read aliases file `%s'", config->aliases);
 488
 489         if ((sender = set_from(&queue, sender)) == NULL)
 490                 errlog(1, NULL);
 491
 492         for (i = 0; i < argc; i++) {
 493                 if (add_recp(&queue, argv[i], 1) != 0)
 494                         errlogx(1, "invalid recipient `%s'", argv[i]);
 495         }
 496
 497         if (LIST_EMPTY(&queue.queue))
 498                 errlogx(1, "no recipients");
 499
 500         if (newspoolf(&queue) != 0)
 501                 errlog(1, "can not create temp file");
 502
 503         setlogident("%s", queue.id);
 504
 505         if (readmail(&queue, nodot) != 0)
 506                 errlog(1, "can not read mail");
 507
 508         if (linkspool(&queue) != 0)
 509                 errlog(1, "can not create spools");
 510
 511         /* From here on the mail is safe. */
 512
 513         if (config->features & DEFER || queue_only)
 514                 return (0);
 515
 516         run_queue(&queue);
 517
 518         /* NOTREACHED */
 519         return (0);
 520 }