spool.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 "dfcompat.h"
  36
  37 #include <sys/file.h>
  38 #include <sys/stat.h>
  39
  40 #include <ctype.h>
  41 #include <dirent.h>
  42 #include <err.h>
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <inttypes.h>
  46 #include <unistd.h>
  47 #include <syslog.h>
  48
  49 #include "dma.h"
  50
  51 /*
  52  * Spool file format:
  53  *
  54  * 'Q'id files (queue):
  55  *   Organized like an RFC822 header, field: value.  Ignores unknown fields.
  56  *   ID: id
  57  *   Sender: envelope-from
  58  *   Recipient: envelope-to
  59  *
  60  * 'M'id files (data):
  61  *   mail data
  62  *
  63  * Each queue file needs to have a corresponding data file.
  64  * One data file might be shared by linking it several times.
  65  *
  66  * Queue ids are unique, formed from the inode of the data file
  67  * and a unique identifier.
  68  */
  69
  70 int
  71 newspoolf(struct queue *queue)
  72 {
  73         char fn[PATH_MAX+1];
  74         struct stat st;
  75         struct stritem *t;
  76         int fd;
  77
  78         if (snprintf(fn, sizeof(fn), "%s/%s", config.spooldir, "tmp_XXXXXXXXXX") <= 0)
  79                 return (-1);
  80
  81         fd = mkstemp(fn);
  82         if (fd < 0)
  83                 return (-1);
  84         /* XXX group rights */
  85         if (fchmod(fd, 0660) < 0)
  86                 goto fail;
  87         if (flock(fd, LOCK_EX) == -1)
  88                 goto fail;
  89         queue->tmpf = strdup(fn);
  90         if (queue->tmpf == NULL)
  91                 goto fail;
  92
  93         /*
  94          * Assign queue id
  95          */
  96         if (fstat(fd, &st) != 0)
  97                 goto fail;
  98         if (asprintf(&queue->id, "%"PRIxMAX, (uintmax_t)st.st_ino) < 0)
  99                 goto fail;
 100
 101         queue->mailf = fdopen(fd, "r+");
 102         if (queue->mailf == NULL)
 103                 goto fail;
 104
 105         t = malloc(sizeof(*t));
 106         if (t != NULL) {
 107                 t->str = queue->tmpf;
 108                 SLIST_INSERT_HEAD(&tmpfs, t, next);
 109         }
 110         return (0);
 111
 112 fail:
 113         if (queue->mailf != NULL)
 114                 fclose(queue->mailf);
 115         close(fd);
 116         unlink(fn);
 117         return (-1);
 118 }
 119
 120 static int
 121 writequeuef(struct qitem *it)
 122 {
 123         int error;
 124         int queuefd;
 125
 126         queuefd = open_locked(it->queuefn, O_CREAT|O_EXCL|O_RDWR, 0660);
 127         if (queuefd == -1)
 128                 return (-1);
 129         if (fchmod(queuefd, 0660) < 0)
 130                 return (-1);
 131         it->queuef = fdopen(queuefd, "w+");
 132         if (it->queuef == NULL)
 133                 return (-1);
 134
 135         error = fprintf(it->queuef,
 136                         "ID: %s\n"
 137                         "Sender: %s\n"
 138                         "Recipient: %s\n",
 139                          it->queueid,
 140                          it->sender,
 141                          it->addr);
 142
 143         if (error <= 0)
 144                 return (-1);
 145
 146         if (fflush(it->queuef) != 0 || fsync(fileno(it->queuef)) != 0)
 147                 return (-1);
 148
 149         return (0);
 150 }
 151
 152 static struct qitem *
 153 readqueuef(struct queue *queue, char *queuefn)
 154 {
 155         char line[1000];
 156         struct queue itmqueue;
 157         FILE *queuef = NULL;
 158         char *s;
 159         char *queueid = NULL, *sender = NULL, *addr = NULL;
 160         struct qitem *it = NULL;
 161
 162         bzero(&itmqueue, sizeof(itmqueue));
 163         LIST_INIT(&itmqueue.queue);
 164
 165         queuef = fopen(queuefn, "r");
 166         if (queuef == NULL)
 167                 goto out;
 168
 169         while (!feof(queuef)) {
 170                 if (fgets(line, sizeof(line), queuef) == NULL || line[0] == 0)
 171                         break;
 172                 line[strlen(line) - 1] = 0;     /* chop newline */
 173
 174                 s = strchr(line, ':');
 175                 if (s == NULL)
 176                         goto malformed;
 177                 *s = 0;
 178
 179                 s++;
 180                 while (isspace(*s))
 181                         s++;
 182
 183                 s = strdup(s);
 184                 if (s == NULL)
 185                         goto malformed;
 186
 187                 if (strcmp(line, "ID") == 0) {
 188                         queueid = s;
 189                 } else if (strcmp(line, "Sender") == 0) {
 190                         sender = s;
 191                 } else if (strcmp(line, "Recipient") == 0) {
 192                         addr = s;
 193                 } else {
 194                         syslog(LOG_DEBUG, "ignoring unknown queue info `%s' in `%s'",
 195                                line, queuefn);
 196                         free(s);
 197                 }
 198         }
 199
 200         if (queueid == NULL || sender == NULL || addr == NULL ||
 201             *queueid == 0 || *addr == 0) {
 202 malformed:
 203                 errno = EINVAL;
 204                 syslog(LOG_ERR, "malformed queue file `%s'", queuefn);
 205                 goto out;
 206         }
 207
 208         if (add_recp(&itmqueue, addr, 0) != 0)
 209                 goto out;
 210
 211         it = LIST_FIRST(&itmqueue.queue);
 212         it->sender = sender; sender = NULL;
 213         it->queueid = queueid; queueid = NULL;
 214         it->queuefn = queuefn; queuefn = NULL;
 215         LIST_INSERT_HEAD(&queue->queue, it, next);
 216
 217 out:
 218         if (sender != NULL)
 219                 free(sender);
 220         if (queueid != NULL)
 221                 free(queueid);
 222         if (addr != NULL)
 223                 free(addr);
 224         if (queuef != NULL)
 225                 fclose(queuef);
 226
 227         return (it);
 228 }
 229
 230 int
 231 linkspool(struct queue *queue)
 232 {
 233         struct stat st;
 234         struct qitem *it;
 235
 236         if (fflush(queue->mailf) != 0 || fsync(fileno(queue->mailf)) != 0)
 237                 goto delfiles;
 238
 239         syslog(LOG_INFO, "new mail from user=%s uid=%d envelope_from=<%s>",
 240                username, getuid(), queue->sender);
 241
 242         LIST_FOREACH(it, &queue->queue, next) {
 243                 if (asprintf(&it->queueid, "%s.%"PRIxPTR, queue->id, (uintptr_t)it) <= 0)
 244                         goto delfiles;
 245                 if (asprintf(&it->queuefn, "%s/Q%s", config.spooldir, it->queueid) <= 0)
 246                         goto delfiles;
 247                 if (asprintf(&it->mailfn, "%s/M%s", config.spooldir, it->queueid) <= 0)
 248                         goto delfiles;
 249
 250                 /* Neither file may not exist yet */
 251                 if (stat(it->queuefn, &st) == 0 || stat(it->mailfn, &st) == 0)
 252                         goto delfiles;
 253
 254                 if (writequeuef(it) != 0)
 255                         goto delfiles;
 256
 257                 if (link(queue->tmpf, it->mailfn) != 0)
 258                         goto delfiles;
 259         }
 260
 261         LIST_FOREACH(it, &queue->queue, next) {
 262                 syslog(LOG_INFO, "mail to=<%s> queued as %s",
 263                        it->addr, it->queueid);
 264         }
 265
 266         unlink(queue->tmpf);
 267         return (0);
 268
 269 delfiles:
 270         LIST_FOREACH(it, &queue->queue, next) {
 271                 unlink(it->mailfn);
 272                 unlink(it->queuefn);
 273         }
 274         return (-1);
 275 }
 276
 277 int
 278 load_queue(struct queue *queue)
 279 {
 280         struct stat sb;
 281         struct qitem *it;
 282         DIR *spooldir;
 283         struct dirent *de;
 284         char *queuefn;
 285         char *mailfn;
 286
 287         bzero(queue, sizeof(queue));
 288         LIST_INIT(&queue->queue);
 289
 290         spooldir = opendir(config.spooldir);
 291         if (spooldir == NULL)
 292                 err(1, "reading queue");
 293
 294         while ((de = readdir(spooldir)) != NULL) {
 295                 queuefn = NULL;
 296                 mailfn = NULL;
 297
 298                 /* ignore non-queue files */
 299                 if (de->d_name[0] != 'Q')
 300                         continue;
 301                 if (asprintf(&queuefn, "%s/Q%s", config.spooldir, de->d_name + 1) < 0)
 302                         goto fail;
 303                 if (asprintf(&mailfn, "%s/M%s", config.spooldir, de->d_name + 1) < 0)
 304                         goto fail;
 305
 306                 /*
 307                  * Some file systems don't provide a de->d_type, so we have to
 308                  * do an explicit stat on the queue file.
 309                  * Move on if it turns out to be something else than a file.
 310                  */
 311                 if (stat(queuefn, &sb) != 0)
 312                         goto skip_item;
 313                 if (!S_ISREG(sb.st_mode)) {
 314                         errno = EINVAL;
 315                         goto skip_item;
 316                 }
 317
 318                 if (stat(mailfn, &sb) != 0)
 319                         goto skip_item;
 320
 321                 it = readqueuef(queue, queuefn);
 322                 if (it == NULL)
 323                         goto skip_item;
 324
 325                 it->mailfn = mailfn;
 326                 continue;
 327
 328 skip_item:
 329                 syslog(LOG_INFO, "could not pick up queue file: `%s'/`%s': %m", queuefn, mailfn);
 330                 if (queuefn != NULL)
 331                         free(queuefn);
 332                 if (mailfn != NULL)
 333                         free(mailfn);
 334         }
 335         closedir(spooldir);
 336         return (0);
 337
 338 fail:
 339         return (-1);
 340 }
 341
 342 void
 343 delqueue(struct qitem *it)
 344 {
 345         unlink(it->mailfn);
 346         unlink(it->queuefn);
 347         if (it->queuef != NULL)
 348                 fclose(it->queuef);
 349         if (it->mailf != NULL)
 350                 fclose(it->mailf);
 351         free(it);
 352 }
 353
 354 int
 355 acquirespool(struct qitem *it)
 356 {
 357         int queuefd;
 358
 359         if (it->queuef == NULL) {
 360                 queuefd = open_locked(it->queuefn, O_RDWR|O_NONBLOCK);
 361                 if (queuefd < 0)
 362                         goto fail;
 363                 it->queuef = fdopen(queuefd, "r+");
 364                 if (it->queuef == NULL)
 365                         goto fail;
 366         }
 367
 368         if (it->mailf == NULL) {
 369                 it->mailf = fopen(it->mailfn, "r");
 370                 if (it->mailf == NULL)
 371                         goto fail;
 372         }
 373
 374         return (0);
 375
 376 fail:
 377         syslog(LOG_INFO, "could not acquire queue file: %m");
 378         return (-1);
 379 }
 380
 381 void
 382 dropspool(struct queue *queue, struct qitem *keep)
 383 {
 384         struct qitem *it;
 385
 386         LIST_FOREACH(it, &queue->queue, next) {
 387                 if (it == keep)
 388                         continue;
 389
 390                 if (it->queuef != NULL)
 391                         fclose(it->queuef);
 392                 if (it->mailf != NULL)
 393                         fclose(it->mailf);
 394         }
 395 }