spool.c

   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/file.h>
  39 #include <sys/stat.h>
  40
  41 #include <ctype.h>
  42 #include <dirent.h>
  43 #include <err.h>
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <inttypes.h>
  47 #include <unistd.h>
  48 #include <syslog.h>
  49
  50 #include "dma.h"
  51
  52 /*
  53  * Spool file format:
  54  *
  55  * 'Q'id files (queue):
  56  *   Organized like an RFC822 header, field: value.  Ignores unknown fields.
  57  *   ID: id
  58  *   Sender: envelope-from
  59  *   Recipient: envelope-to
  60  *
  61  * 'M'id files (data):
  62  *   mail data
  63  *
  64  * Each queue file needs to have a corresponding data file.
  65  * One data file might be shared by linking it several times.
  66  *
  67  * Queue ids are unique, formed from the inode of the data file
  68  * and a unique identifier.
  69  */
  70
  71 int
  72 newspoolf(struct queue *queue)
  73 {
  74         char fn[PATH_MAX+1];
  75         struct stat st;
  76         struct stritem *t;
  77         int fd;
  78
  79         if (snprintf(fn, sizeof(fn), "%s/%s", config.spooldir, "tmp_XXXXXXXXXX") <= 0)
  80                 return (-1);
  81
  82         fd = mkstemp(fn);
  83         if (fd < 0)
  84                 return (-1);
  85         /* XXX group rights */
  86         if (fchmod(fd, 0660) < 0)
  87                 goto fail;
  88         if (flock(fd, LOCK_EX) == -1)
  89                 goto fail;
  90         queue->tmpf = strdup(fn);
  91         if (queue->tmpf == NULL)
  92                 goto fail;
  93
  94         /*
  95          * Assign queue id
  96          */
  97         if (fstat(fd, &st) != 0)
  98                 goto fail;
  99         if (asprintf(&queue->id, "%"PRIxMAX, (uintmax_t)st.st_ino) < 0)
 100                 goto fail;
 101
 102         queue->mailf = fdopen(fd, "r+");
 103         if (queue->mailf == NULL)
 104                 goto fail;
 105
 106         t = malloc(sizeof(*t));
 107         if (t != NULL) {
 108                 t->str = queue->tmpf;
 109                 SLIST_INSERT_HEAD(&tmpfs, t, next);
 110         }
 111         return (0);
 112
 113 fail:
 114         if (queue->mailf != NULL)
 115                 fclose(queue->mailf);
 116         close(fd);
 117         unlink(fn);
 118         return (-1);
 119 }
 120
 121 static int
 122 writequeuef(struct qitem *it)
 123 {
 124         int error;
 125         int queuefd;
 126
 127         queuefd = open_locked(it->queuefn, O_CREAT|O_EXCL|O_RDWR, 0660);
 128         if (queuefd == -1)
 129                 return (-1);
 130         if (fchmod(queuefd, 0660) < 0)
 131                 return (-1);
 132         it->queuef = fdopen(queuefd, "w+");
 133         if (it->queuef == NULL)
 134                 return (-1);
 135
 136         error = fprintf(it->queuef,
 137                         "ID: %s\n"
 138                         "Sender: %s\n"
 139                         "Recipient: %s\n",
 140                          it->queueid,
 141                          it->sender,
 142                          it->addr);
 143
 144         if (error <= 0)
 145                 return (-1);
 146
 147         if (fflush(it->queuef) != 0 || fsync(fileno(it->queuef)) != 0)
 148                 return (-1);
 149
 150         return (0);
 151 }
 152
 153 static struct qitem *
 154 readqueuef(struct queue *queue, char *queuefn)
 155 {
 156         char line[1000];
 157         struct queue itmqueue;
 158         FILE *queuef = NULL;
 159         char *s;
 160         char *queueid = NULL, *sender = NULL, *addr = NULL;
 161         struct qitem *it = NULL;
 162
 163         bzero(&itmqueue, sizeof(itmqueue));
 164         LIST_INIT(&itmqueue.queue);
 165
 166         queuef = fopen(queuefn, "r");
 167         if (queuef == NULL)
 168                 goto out;
 169
 170         while (!feof(queuef)) {
 171                 if (fgets(line, sizeof(line), queuef) == NULL || line[0] == 0)
 172                         break;
 173                 line[strlen(line) - 1] = 0;     /* chop newline */
 174
 175                 s = strchr(line, ':');
 176                 if (s == NULL)
 177                         goto malformed;
 178                 *s = 0;
 179
 180                 s++;
 181                 while (isspace(*s))
 182                         s++;
 183
 184                 s = strdup(s);
 185                 if (s == NULL)
 186                         goto malformed;
 187
 188                 if (strcmp(line, "ID") == 0) {
 189                         queueid = s;
 190                 } else if (strcmp(line, "Sender") == 0) {
 191                         sender = s;
 192                 } else if (strcmp(line, "Recipient") == 0) {
 193                         addr = s;
 194                 } else {
 195                         syslog(LOG_DEBUG, "ignoring unknown queue info `%s' in `%s'",
 196                                line, queuefn);
 197                         free(s);
 198                 }
 199         }
 200
 201         if (queueid == NULL || sender == NULL || addr == NULL ||
 202             *queueid == 0 || *addr == 0) {
 203 malformed:
 204                 errno = EINVAL;
 205                 syslog(LOG_ERR, "malformed queue file `%s'", queuefn);
 206                 goto out;
 207         }
 208
 209         if (add_recp(&itmqueue, addr, 0) != 0)
 210                 goto out;
 211
 212         it = LIST_FIRST(&itmqueue.queue);
 213         it->sender = sender; sender = NULL;
 214         it->queueid = queueid; queueid = NULL;
 215         it->queuefn = queuefn; queuefn = NULL;
 216         LIST_INSERT_HEAD(&queue->queue, it, next);
 217
 218 out:
 219         if (sender != NULL)
 220                 free(sender);
 221         if (queueid != NULL)
 222                 free(queueid);
 223         if (addr != NULL)
 224                 free(addr);
 225         if (queuef != NULL)
 226                 fclose(queuef);
 227
 228         return (it);
 229 }
 230
 231 int
 232 linkspool(struct queue *queue)
 233 {
 234         struct stat st;
 235         struct qitem *it;
 236
 237         if (fflush(queue->mailf) != 0 || fsync(fileno(queue->mailf)) != 0)
 238                 goto delfiles;
 239
 240         syslog(LOG_INFO, "new mail from user=%s uid=%d envelope_from=<%s>",
 241                username, getuid(), queue->sender);
 242
 243         LIST_FOREACH(it, &queue->queue, next) {
 244                 if (asprintf(&it->queueid, "%s.%"PRIxPTR, queue->id, (uintptr_t)it) <= 0)
 245                         goto delfiles;
 246                 if (asprintf(&it->queuefn, "%s/Q%s", config.spooldir, it->queueid) <= 0)
 247                         goto delfiles;
 248                 if (asprintf(&it->mailfn, "%s/M%s", config.spooldir, it->queueid) <= 0)
 249                         goto delfiles;
 250
 251                 /* Neither file may not exist yet */
 252                 if (stat(it->queuefn, &st) == 0 || stat(it->mailfn, &st) == 0)
 253                         goto delfiles;
 254
 255                 if (writequeuef(it) != 0)
 256                         goto delfiles;
 257
 258                 if (link(queue->tmpf, it->mailfn) != 0)
 259                         goto delfiles;
 260         }
 261
 262         LIST_FOREACH(it, &queue->queue, next) {
 263                 syslog(LOG_INFO, "mail to=<%s> queued as %s",
 264                        it->addr, it->queueid);
 265         }
 266
 267         unlink(queue->tmpf);
 268         return (0);
 269
 270 delfiles:
 271         LIST_FOREACH(it, &queue->queue, next) {
 272                 unlink(it->mailfn);
 273                 unlink(it->queuefn);
 274         }
 275         return (-1);
 276 }
 277
 278 int
 279 load_queue(struct queue *queue)
 280 {
 281         struct stat sb;
 282         struct qitem *it;
 283         DIR *spooldir;
 284         struct dirent *de;
 285         char *queuefn;
 286         char *mailfn;
 287
 288         bzero(queue, sizeof(*queue));
 289         LIST_INIT(&queue->queue);
 290
 291         spooldir = opendir(config.spooldir);
 292         if (spooldir == NULL)
 293                 err(EX_NOINPUT, "reading queue");
 294
 295         while ((de = readdir(spooldir)) != NULL) {
 296                 queuefn = NULL;
 297                 mailfn = NULL;
 298
 299                 /* ignore non-queue files */
 300                 if (de->d_name[0] != 'Q')
 301                         continue;
 302                 if (asprintf(&queuefn, "%s/Q%s", config.spooldir, de->d_name + 1) < 0)
 303                         goto fail;
 304                 if (asprintf(&mailfn, "%s/M%s", config.spooldir, de->d_name + 1) < 0)
 305                         goto fail;
 306
 307                 /*
 308                  * Some file systems don't provide a de->d_type, so we have to
 309                  * do an explicit stat on the queue file.
 310                  * Move on if it turns out to be something else than a file.
 311                  */
 312                 if (stat(queuefn, &sb) != 0)
 313                         goto skip_item;
 314                 if (!S_ISREG(sb.st_mode)) {
 315                         errno = EINVAL;
 316                         goto skip_item;
 317                 }
 318
 319                 if (stat(mailfn, &sb) != 0)
 320                         goto skip_item;
 321
 322                 it = readqueuef(queue, queuefn);
 323                 if (it == NULL)
 324                         goto skip_item;
 325
 326                 it->mailfn = mailfn;
 327                 continue;
 328
 329 skip_item:
 330                 syslog(LOG_INFO, "could not pick up queue file: `%s'/`%s': %m", queuefn, mailfn);
 331                 if (queuefn != NULL)
 332                         free(queuefn);
 333                 if (mailfn != NULL)
 334                         free(mailfn);
 335         }
 336         closedir(spooldir);
 337         return (0);
 338
 339 fail:
 340         return (-1);
 341 }
 342
 343 void
 344 delqueue(struct qitem *it)
 345 {
 346         unlink(it->mailfn);
 347         unlink(it->queuefn);
 348         if (it->queuef != NULL)
 349                 fclose(it->queuef);
 350         if (it->mailf != NULL)
 351                 fclose(it->mailf);
 352         free(it);
 353 }
 354
 355 int
 356 acquirespool(struct qitem *it)
 357 {
 358         int queuefd;
 359
 360         if (it->queuef == NULL) {
 361                 queuefd = open_locked(it->queuefn, O_RDWR|O_NONBLOCK);
 362                 if (queuefd < 0)
 363                         goto fail;
 364                 it->queuef = fdopen(queuefd, "r+");
 365                 if (it->queuef == NULL)
 366                         goto fail;
 367         }
 368
 369         if (it->mailf == NULL) {
 370                 it->mailf = fopen(it->mailfn, "r");
 371                 if (it->mailf == NULL)
 372                         goto fail;
 373         }
 374
 375         return (0);
 376
 377 fail:
 378         if (errno == EWOULDBLOCK)
 379                 return (1);
 380         syslog(LOG_INFO, "could not acquire queue file: %m");
 381         return (-1);
 382 }
 383
 384 void
 385 dropspool(struct queue *queue, struct qitem *keep)
 386 {
 387         struct qitem *it;
 388
 389         LIST_FOREACH(it, &queue->queue, next) {
 390                 if (it == keep)
 391                         continue;
 392
 393                 if (it->queuef != NULL)
 394                         fclose(it->queuef);
 395                 if (it->mailf != NULL)
 396                         fclose(it->mailf);
 397         }
 398 }
 399
 400 int
 401 flushqueue_since(unsigned int period)
 402 {
 403         struct stat st;
 404         struct timeval now;
 405         char *flushfn = NULL;
 406
 407         if (asprintf(&flushfn, "%s/%s", config.spooldir, SPOOL_FLUSHFILE) < 0)
 408                 return (0);
 409         if (stat(flushfn, &st) < 0) {
 410                 free(flushfn);
 411                 return (0);
 412         }
 413         free(flushfn);
 414         flushfn = NULL;
 415         if (gettimeofday(&now, 0) != 0)
 416                 return (0);
 417
 418         /* Did the flush file get touched within the last period seconds? */
 419         if (st.st_mtim.tv_sec + period >= now.tv_sec)
 420                 return (1);
 421         else
 422                 return (0);
 423 }
 424
 425 int
 426 flushqueue_signal(void)
 427 {
 428         char *flushfn = NULL;
 429         int fd;
 430
 431         if (asprintf(&flushfn, "%s/%s", config.spooldir, SPOOL_FLUSHFILE) < 0)
 432                 return (-1);
 433         fd = open(flushfn, O_CREAT|O_WRONLY|O_TRUNC, 0660);
 434         free(flushfn);
 435         if (fd < 0) {
 436                 syslog(LOG_ERR, "could not open flush file: %m");
 437                 return (-1);
 438         }
 439         close(fd);
 440         return (0);
 441 }