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 <string.h>
49#include <syslog.h>
50
51#include "dma.h"
52
53/*
54 * Spool file format:
55 *
56 * 'Q'id files (queue):
57 *   Organized like an RFC822 header, field: value.  Ignores unknown fields.
58 *   ID: id
59 *   Sender: envelope-from
60 *   Recipient: envelope-to
61 *
62 * 'M'id files (data):
63 *   mail data
64 *
65 * Each queue file needs to have a corresponding data file.
66 * One data file might be shared by linking it several times.
67 *
68 * Queue ids are unique, formed from the inode of the data file
69 * and a unique identifier.
70 */
71
72int
73newspoolf(struct queue *queue)
74{
75	char fn[PATH_MAX+1];
76	struct stat st;
77	struct stritem *t;
78	int fd;
79
80	if (snprintf(fn, sizeof(fn), "%s/%s", config.spooldir, "tmp_XXXXXXXXXX") <= 0)
81		return (-1);
82
83	fd = mkstemp(fn);
84	if (fd < 0)
85		return (-1);
86	/* XXX group rights */
87	if (fchmod(fd, 0660) < 0)
88		goto fail;
89	if (flock(fd, LOCK_EX) == -1)
90		goto fail;
91	queue->tmpf = strdup(fn);
92	if (queue->tmpf == NULL)
93		goto fail;
94
95	/*
96	 * Assign queue id
97	 */
98	if (fstat(fd, &st) != 0)
99		goto fail;
100	if (asprintf(&queue->id, "%"PRIxMAX, (uintmax_t)st.st_ino) < 0)
101		goto fail;
102
103	queue->mailf = fdopen(fd, "r+");
104	if (queue->mailf == NULL)
105		goto fail;
106
107	t = malloc(sizeof(*t));
108	if (t != NULL) {
109		t->str = queue->tmpf;
110		SLIST_INSERT_HEAD(&tmpfs, t, next);
111	}
112	return (0);
113
114fail:
115	if (queue->mailf != NULL)
116		fclose(queue->mailf);
117	close(fd);
118	unlink(fn);
119	return (-1);
120}
121
122static int
123writequeuef(struct qitem *it)
124{
125	int error;
126	int queuefd;
127
128	queuefd = open_locked(it->queuefn, O_CREAT|O_EXCL|O_RDWR, 0660);
129	if (queuefd == -1)
130		return (-1);
131	if (fchmod(queuefd, 0660) < 0)
132		return (-1);
133	it->queuef = fdopen(queuefd, "w+");
134	if (it->queuef == NULL)
135		return (-1);
136
137	error = fprintf(it->queuef,
138			"ID: %s\n"
139			"Sender: %s\n"
140			"Recipient: %s\n",
141			 it->queueid,
142			 it->sender,
143			 it->addr);
144
145	if (error <= 0)
146		return (-1);
147
148	if (fflush(it->queuef) != 0 || fsync(fileno(it->queuef)) != 0)
149		return (-1);
150
151	return (0);
152}
153
154static struct qitem *
155readqueuef(struct queue *queue, char *queuefn)
156{
157	char line[1000];
158	struct queue itmqueue;
159	FILE *queuef = NULL;
160	char *s;
161	char *queueid = NULL, *sender = NULL, *addr = NULL;
162	struct qitem *it = NULL;
163
164	bzero(&itmqueue, sizeof(itmqueue));
165	LIST_INIT(&itmqueue.queue);
166
167	queuef = fopen(queuefn, "r");
168	if (queuef == NULL)
169		goto out;
170
171	while (!feof(queuef)) {
172		if (fgets(line, sizeof(line), queuef) == NULL || line[0] == 0)
173			break;
174		line[strlen(line) - 1] = 0;	/* chop newline */
175
176		s = strchr(line, ':');
177		if (s == NULL)
178			goto malformed;
179		*s = 0;
180
181		s++;
182		while (isspace(*s))
183			s++;
184
185		s = strdup(s);
186		if (s == NULL)
187			goto malformed;
188
189		if (strcmp(line, "ID") == 0) {
190			queueid = s;
191		} else if (strcmp(line, "Sender") == 0) {
192			sender = s;
193		} else if (strcmp(line, "Recipient") == 0) {
194			addr = s;
195		} else {
196			syslog(LOG_DEBUG, "ignoring unknown queue info `%s' in `%s'",
197			       line, queuefn);
198			free(s);
199		}
200	}
201
202	if (queueid == NULL || sender == NULL || addr == NULL ||
203	    *queueid == 0 || *addr == 0) {
204malformed:
205		errno = EINVAL;
206		syslog(LOG_ERR, "malformed queue file `%s'", queuefn);
207		goto out;
208	}
209
210	if (add_recp(&itmqueue, addr, 0) != 0)
211		goto out;
212
213	it = LIST_FIRST(&itmqueue.queue);
214	it->sender = sender; sender = NULL;
215	it->queueid = queueid; queueid = NULL;
216	it->queuefn = queuefn; queuefn = NULL;
217	LIST_INSERT_HEAD(&queue->queue, it, next);
218
219out:
220	if (sender != NULL)
221		free(sender);
222	if (queueid != NULL)
223		free(queueid);
224	if (addr != NULL)
225		free(addr);
226	if (queuef != NULL)
227		fclose(queuef);
228
229	return (it);
230}
231
232int
233linkspool(struct queue *queue)
234{
235	struct stat st;
236	struct qitem *it;
237
238	if (fflush(queue->mailf) != 0 || fsync(fileno(queue->mailf)) != 0)
239		goto delfiles;
240
241	syslog(LOG_INFO, "new mail from user=%s uid=%d envelope_from=<%s>",
242	       username, getuid(), queue->sender);
243
244	LIST_FOREACH(it, &queue->queue, next) {
245		if (asprintf(&it->queueid, "%s.%"PRIxPTR, queue->id, (uintptr_t)it) <= 0)
246			goto delfiles;
247		if (asprintf(&it->queuefn, "%s/Q%s", config.spooldir, it->queueid) <= 0)
248			goto delfiles;
249		if (asprintf(&it->mailfn, "%s/M%s", config.spooldir, it->queueid) <= 0)
250			goto delfiles;
251
252		/* Neither file may not exist yet */
253		if (stat(it->queuefn, &st) == 0 || stat(it->mailfn, &st) == 0)
254			goto delfiles;
255
256		if (writequeuef(it) != 0)
257			goto delfiles;
258
259		if (link(queue->tmpf, it->mailfn) != 0)
260			goto delfiles;
261	}
262
263	LIST_FOREACH(it, &queue->queue, next) {
264		syslog(LOG_INFO, "mail to=<%s> queued as %s",
265		       it->addr, it->queueid);
266	}
267
268	unlink(queue->tmpf);
269	return (0);
270
271delfiles:
272	LIST_FOREACH(it, &queue->queue, next) {
273		unlink(it->mailfn);
274		unlink(it->queuefn);
275	}
276	return (-1);
277}
278
279int
280load_queue(struct queue *queue)
281{
282	struct stat sb;
283	struct qitem *it;
284	DIR *spooldir;
285	struct dirent *de;
286	char *queuefn;
287	char *mailfn;
288
289	bzero(queue, sizeof(*queue));
290	LIST_INIT(&queue->queue);
291
292	spooldir = opendir(config.spooldir);
293	if (spooldir == NULL)
294		err(EX_NOINPUT, "reading queue");
295
296	while ((de = readdir(spooldir)) != NULL) {
297		queuefn = NULL;
298		mailfn = NULL;
299
300		/* ignore non-queue files */
301		if (de->d_name[0] != 'Q')
302			continue;
303		if (asprintf(&queuefn, "%s/Q%s", config.spooldir, de->d_name + 1) < 0)
304			goto fail;
305		if (asprintf(&mailfn, "%s/M%s", config.spooldir, de->d_name + 1) < 0)
306			goto fail;
307
308		/*
309		 * Some file systems don't provide a de->d_type, so we have to
310		 * do an explicit stat on the queue file.
311		 * Move on if it turns out to be something else than a file.
312		 */
313		if (stat(queuefn, &sb) != 0)
314			goto skip_item;
315		if (!S_ISREG(sb.st_mode)) {
316			errno = EINVAL;
317			goto skip_item;
318		}
319
320		if (stat(mailfn, &sb) != 0)
321			goto skip_item;
322
323		it = readqueuef(queue, queuefn);
324		if (it == NULL)
325			goto skip_item;
326
327		it->mailfn = mailfn;
328		continue;
329
330skip_item:
331		syslog(LOG_INFO, "could not pick up queue file: `%s'/`%s': %m", queuefn, mailfn);
332		if (queuefn != NULL)
333			free(queuefn);
334		if (mailfn != NULL)
335			free(mailfn);
336	}
337	closedir(spooldir);
338	return (0);
339
340fail:
341	return (-1);
342}
343
344void
345delqueue(struct qitem *it)
346{
347	unlink(it->mailfn);
348	unlink(it->queuefn);
349	if (it->queuef != NULL)
350		fclose(it->queuef);
351	if (it->mailf != NULL)
352		fclose(it->mailf);
353	free(it);
354}
355
356int
357acquirespool(struct qitem *it)
358{
359	int queuefd;
360
361	if (it->queuef == NULL) {
362		queuefd = open_locked(it->queuefn, O_RDWR|O_NONBLOCK);
363		if (queuefd < 0)
364			goto fail;
365		it->queuef = fdopen(queuefd, "r+");
366		if (it->queuef == NULL)
367			goto fail;
368	}
369
370	if (it->mailf == NULL) {
371		it->mailf = fopen(it->mailfn, "r");
372		if (it->mailf == NULL)
373			goto fail;
374	}
375
376	return (0);
377
378fail:
379	if (errno == EWOULDBLOCK)
380		return (1);
381	syslog(LOG_INFO, "could not acquire queue file: %m");
382	return (-1);
383}
384
385void
386dropspool(struct queue *queue, struct qitem *keep)
387{
388	struct qitem *it;
389
390	LIST_FOREACH(it, &queue->queue, next) {
391		if (it == keep)
392			continue;
393
394		if (it->queuef != NULL)
395			fclose(it->queuef);
396		if (it->mailf != NULL)
397			fclose(it->mailf);
398	}
399}
400
401int
402flushqueue_since(unsigned int period)
403{
404        struct stat st;
405	struct timeval now;
406        char *flushfn = NULL;
407
408	if (asprintf(&flushfn, "%s/%s", config.spooldir, SPOOL_FLUSHFILE) < 0)
409		return (0);
410	if (stat(flushfn, &st) < 0) {
411		free(flushfn);
412		return (0);
413	}
414	free(flushfn);
415	flushfn = NULL;
416	if (gettimeofday(&now, 0) != 0)
417		return (0);
418
419	/* Did the flush file get touched within the last period seconds? */
420	if (st.st_mtim.tv_sec + (int)period >= now.tv_sec)
421		return (1);
422	else
423		return (0);
424}
425
426int
427flushqueue_signal(void)
428{
429        char *flushfn = NULL;
430	int fd;
431
432        if (asprintf(&flushfn, "%s/%s", config.spooldir, SPOOL_FLUSHFILE) < 0)
433		return (-1);
434	fd = open(flushfn, O_CREAT|O_WRONLY|O_TRUNC, 0660);
435	free(flushfn);
436	if (fd < 0) {
437		syslog(LOG_ERR, "could not open flush file: %m");
438		return (-1);
439	}
440        close(fd);
441	return (0);
442}
443