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, 0600);
 127         if (queuefd == -1)
 128                 return (-1);
 129         it->queuef = fdopen(queuefd, "w+");
 130         if (it->queuef == NULL)
 131                 return (-1);
 132
 133         error = fprintf(it->queuef,
 134                         "ID: %s\n"
 135                         "Sender: %s\n"
 136                         "Recipient: %s\n",
 137                          it->queueid,
 138                          it->sender,
 139                          it->addr);
 140
 141         if (error <= 0)
 142                 return (-1);
 143
 144         if (fflush(it->queuef) != 0 || fsync(fileno(it->queuef)) != 0)
 145                 return (-1);
 146
 147         return (0);
 148 }
 149
 150 static struct qitem *
 151 readqueuef(struct queue *queue, char *queuefn)
 152 {
 153         char line[1000];
 154         struct queue itmqueue;
 155         FILE *queuef = NULL;
 156         char *s;
 157         char *queueid = NULL, *sender = NULL, *addr = NULL;
 158         struct qitem *it = NULL;
 159
 160         bzero(&itmqueue, sizeof(itmqueue));
 161         LIST_INIT(&itmqueue.queue);
 162
 163         queuef = fopen(queuefn, "r");
 164         if (queuef == NULL)
 165                 goto out;
 166
 167         while (!feof(queuef)) {
 168                 if (fgets(line, sizeof(line), queuef) == NULL || line[0] == 0)
 169                         break;
 170                 line[strlen(line) - 1] = 0;     /* chop newline */
 171
 172                 s = strchr(line, ':');
 173                 if (s == NULL)
 174                         goto malformed;
 175                 *s = 0;
 176
 177                 s++;
 178                 while (isspace(*s))
 179                         s++;
 180
 181                 s = strdup(s);
 182                 if (s == NULL)
 183                         goto malformed;
 184
 185                 if (strcmp(line, "ID") == 0) {
 186                         queueid = s;
 187                 } else if (strcmp(line, "Sender") == 0) {
 188                         sender = s;
 189                 } else if (strcmp(line, "Recipient") == 0) {
 190                         addr = s;
 191                 } else {
 192                         syslog(LOG_DEBUG, "ignoring unknown queue info `%s' in `%s'",
 193                                line, queuefn);
 194                         free(s);
 195                 }
 196         }
 197
 198         if (queueid == NULL || sender == NULL || addr == NULL ||
 199             *queueid == 0 || *addr == 0) {
 200 malformed:
 201                 errno = EINVAL;
 202                 syslog(LOG_ERR, "malformed queue file `%s'", queuefn);
 203                 goto out;
 204         }
 205
 206         if (add_recp(&itmqueue, addr, 0) != 0)
 207                 goto out;
 208
 209         it = LIST_FIRST(&itmqueue.queue);
 210         it->sender = sender; sender = NULL;
 211         it->queueid = queueid; queueid = NULL;
 212         it->queuefn = queuefn; queuefn = NULL;
 213         LIST_INSERT_HEAD(&queue->queue, it, next);
 214
 215 out:
 216         if (sender != NULL)
 217                 free(sender);
 218         if (queueid != NULL)
 219                 free(queueid);
 220         if (addr != NULL)
 221                 free(addr);
 222         if (queuef != NULL)
 223                 fclose(queuef);
 224
 225         return (it);
 226 }
 227
 228 int
 229 linkspool(struct queue *queue)
 230 {
 231         struct stat st;
 232         struct qitem *it;
 233
 234         if (fflush(queue->mailf) != 0 || fsync(fileno(queue->mailf)) != 0)
 235                 goto delfiles;
 236
 237         syslog(LOG_INFO, "new mail from user=%s uid=%d envelope_from=<%s>",
 238                username, getuid(), queue->sender);
 239
 240         LIST_FOREACH(it, &queue->queue, next) {
 241                 if (asprintf(&it->queueid, "%s.%"PRIxPTR, queue->id, (uintptr_t)it) <= 0)
 242                         goto delfiles;
 243                 if (asprintf(&it->queuefn, "%s/Q%s", config.spooldir, it->queueid) <= 0)
 244                         goto delfiles;
 245                 if (asprintf(&it->mailfn, "%s/M%s", config.spooldir, it->queueid) <= 0)
 246                         goto delfiles;
 247
 248                 /* Neither file may not exist yet */
 249                 if (stat(it->queuefn, &st) == 0 || stat(it->mailfn, &st) == 0)
 250                         goto delfiles;
 251
 252                 if (writequeuef(it) != 0)
 253                         goto delfiles;
 254
 255                 if (link(queue->tmpf, it->mailfn) != 0)
 256                         goto delfiles;
 257         }
 258
 259         LIST_FOREACH(it, &queue->queue, next) {
 260                 syslog(LOG_INFO, "mail to=<%s> queued as %s",
 261                        it->addr, it->queueid);
 262         }
 263
 264         unlink(queue->tmpf);
 265         return (0);
 266
 267 delfiles:
 268         LIST_FOREACH(it, &queue->queue, next) {
 269                 unlink(it->mailfn);
 270                 unlink(it->queuefn);
 271         }
 272         return (-1);
 273 }
 274
 275 int
 276 load_queue(struct queue *queue)
 277 {
 278         struct stat sb;
 279         struct qitem *it;
 280         DIR *spooldir;
 281         struct dirent *de;
 282         char *queuefn;
 283         char *mailfn;
 284
 285         bzero(queue, sizeof(queue));
 286         LIST_INIT(&queue->queue);
 287
 288         spooldir = opendir(config.spooldir);
 289         if (spooldir == NULL)
 290                 err(1, "reading queue");
 291
 292         while ((de = readdir(spooldir)) != NULL) {
 293                 queuefn = NULL;
 294                 mailfn = NULL;
 295
 296                 /* ignore non-queue files */
 297                 if (de->d_name[0] != 'Q')
 298                         continue;
 299                 if (asprintf(&queuefn, "%s/Q%s", config.spooldir, de->d_name + 1) < 0)
 300                         goto fail;
 301                 if (asprintf(&mailfn, "%s/M%s", config.spooldir, de->d_name + 1) < 0)
 302                         goto fail;
 303
 304                 /*
 305                  * Some file systems don't provide a de->d_type, so we have to
 306                  * do an explicit stat on the queue file.
 307                  * Move on if it turns out to be something else than a file.
 308                  */
 309                 if (stat(queuefn, &sb) != 0)
 310                         goto skip_item;
 311                 if (!S_ISREG(sb.st_mode)) {
 312                         errno = EINVAL;
 313                         goto skip_item;
 314                 }
 315
 316                 if (stat(mailfn, &sb) != 0)
 317                         goto skip_item;
 318
 319                 it = readqueuef(queue, queuefn);
 320                 if (it == NULL)
 321                         goto skip_item;
 322
 323                 it->mailfn = mailfn;
 324                 continue;
 325
 326 skip_item:
 327                 syslog(LOG_INFO, "could not pick up queue file: `%s'/`%s': %m", queuefn, mailfn);
 328                 if (queuefn != NULL)
 329                         free(queuefn);
 330                 if (mailfn != NULL)
 331                         free(mailfn);
 332         }
 333         closedir(spooldir);
 334         return (0);
 335
 336 fail:
 337         return (-1);
 338 }
 339
 340 void
 341 delqueue(struct qitem *it)
 342 {
 343         unlink(it->mailfn);
 344         unlink(it->queuefn);
 345         if (it->queuef != NULL)
 346                 fclose(it->queuef);
 347         if (it->mailf != NULL)
 348                 fclose(it->mailf);
 349         free(it);
 350 }
 351
 352 int
 353 acquirespool(struct qitem *it)
 354 {
 355         int queuefd;
 356
 357         if (it->queuef == NULL) {
 358                 queuefd = open_locked(it->queuefn, O_RDWR|O_NONBLOCK);
 359                 if (queuefd < 0)
 360                         goto fail;
 361                 it->queuef = fdopen(queuefd, "r+");
 362                 if (it->queuef == NULL)
 363                         goto fail;
 364         }
 365
 366         if (it->mailf == NULL) {
 367                 it->mailf = fopen(it->mailfn, "r");
 368                 if (it->mailf == NULL)
 369                         goto fail;
 370         }
 371
 372         return (0);
 373
 374 fail:
 375         syslog(LOG_INFO, "could not acquire queue file: %m");
 376         return (-1);
 377 }
 378
 379 void
 380 dropspool(struct queue *queue, struct qitem *keep)
 381 {
 382         struct qitem *it;
 383
 384         LIST_FOREACH(it, &queue->queue, next) {
 385                 if (it == keep)
 386                         continue;
 387
 388                 if (it->queuef != NULL)
 389                         fclose(it->queuef);
 390                 if (it->mailf != NULL)
 391                         fclose(it->mailf);
 392         }
 393 }