xref: /dragonfly/libexec/dma/dma.c (revision ad9f8794) 
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/types.h>
37 #include <sys/queue.h>
38 #include <sys/stat.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 static void deliver(struct qitem *);
60 
61 struct aliases aliases = LIST_HEAD_INITIALIZER(aliases);
62 struct strlist tmpfs = SLIST_HEAD_INITIALIZER(tmpfs);
63 struct virtusers virtusers = LIST_HEAD_INITIALIZER(virtusers);
64 struct authusers authusers = LIST_HEAD_INITIALIZER(authusers);
65 const char *username;
66 const char *logident_base;
67 
68 static int daemonize = 1;
69 
70 struct config config = {
71 	.smarthost	= NULL,
72 	.port		= 25,
73 	.aliases	= "/var/mail/aliases",
74 	.spooldir	= "/var/spool/dma",
75 	.virtualpath	= NULL,
76 	.authpath	= NULL,
77 	.certfile	= NULL,
78 	.features	= 0,
79 	.mailname	= NULL,
80 	.mailnamefile	= NULL,
81 };
82 
83 
84 static char *
85 set_from(struct queue *queue, const char *osender)
86 {
87 	struct virtuser *v;
88 	char *sender;
89 
90 	if ((config.features & VIRTUAL) != 0) {
91 		SLIST_FOREACH(v, &virtusers, next) {
92 			if (strcmp(v->login, username) == 0) {
93 				sender = strdup(v->address);
94 				if (sender == NULL)
95 					return(NULL);
96 				goto out;
97 			}
98 		}
99 	}
100 
101 	if (osender) {
102 		sender = strdup(osender);
103 		if (sender == NULL)
104 			return (NULL);
105 	} else {
106 		if (asprintf(&sender, "%s@%s", username, hostname()) <= 0)
107 			return (NULL);
108 	}
109 
110 	if (strchr(sender, '\n') != NULL) {
111 		errno = EINVAL;
112 		return (NULL);
113 	}
114 
115 out:
116 	queue->sender = sender;
117 	return (sender);
118 }
119 
120 static int
121 read_aliases(void)
122 {
123 	yyin = fopen(config.aliases, "r");
124 	if (yyin == NULL) {
125 		/*
126 		 * Non-existing aliases file is not a fatal error
127 		 */
128 		if (errno == ENOENT)
129 			return (0);
130 		/* Other problems are. */
131 		return (-1);
132 	}
133 	if (yyparse())
134 		return (-1);	/* fatal error, probably malloc() */
135 	fclose(yyin);
136 	return (0);
137 }
138 
139 int
140 add_recp(struct queue *queue, const char *str, int expand)
141 {
142 	struct qitem *it, *tit;
143 	struct stritem *sit;
144 	struct alias *al;
145 	struct passwd *pw;
146 	char *host;
147 	int aliased = 0;
148 
149 	it = calloc(1, sizeof(*it));
150 	if (it == NULL)
151 		return (-1);
152 	it->addr = strdup(str);
153 	if (it->addr == NULL)
154 		return (-1);
155 
156 	it->sender = queue->sender;
157 	host = strrchr(it->addr, '@');
158 	if (host != NULL &&
159 	    (strcmp(host + 1, hostname()) == 0 ||
160 	     strcmp(host + 1, "localhost") == 0)) {
161 		*host = 0;
162 	}
163 	LIST_FOREACH(tit, &queue->queue, next) {
164 		/* weed out duplicate dests */
165 		if (strcmp(tit->addr, it->addr) == 0) {
166 			free(it->addr);
167 			free(it);
168 			return (0);
169 		}
170 	}
171 	LIST_INSERT_HEAD(&queue->queue, it, next);
172 	if (strrchr(it->addr, '@') == NULL) {
173 		it->remote = 0;
174 		if (expand) {
175 			LIST_FOREACH(al, &aliases, next) {
176 				if (strcmp(al->alias, it->addr) != 0)
177 					continue;
178 				SLIST_FOREACH(sit, &al->dests, next) {
179 					if (add_recp(queue, sit->str, 1) != 0)
180 						return (-1);
181 				}
182 				aliased = 1;
183 			}
184 			if (aliased) {
185 				LIST_REMOVE(it, next);
186 			} else {
187 				/* Local destination, check */
188 				pw = getpwnam(it->addr);
189 				if (pw == NULL)
190 					goto out;
191 				/* XXX read .forward */
192 				endpwent();
193 			}
194 		}
195 	} else {
196 		it->remote = 1;
197 	}
198 
199 	return (0);
200 
201 out:
202 	free(it->addr);
203 	free(it);
204 	return (-1);
205 }
206 
207 static struct qitem *
208 go_background(struct queue *queue)
209 {
210 	struct sigaction sa;
211 	struct qitem *it;
212 	pid_t pid;
213 
214 	if (daemonize && daemon(0, 0) != 0) {
215 		syslog(LOG_ERR, "can not daemonize: %m");
216 		exit(1);
217 	}
218 	daemonize = 0;
219 
220 	bzero(&sa, sizeof(sa));
221 	sa.sa_flags = SA_NOCLDWAIT;
222 	sa.sa_handler = SIG_IGN;
223 	sigaction(SIGCHLD, &sa, NULL);
224 
225 	LIST_FOREACH(it, &queue->queue, next) {
226 		/* No need to fork for the last dest */
227 		if (LIST_NEXT(it, next) == NULL)
228 			goto retit;
229 
230 		pid = fork();
231 		switch (pid) {
232 		case -1:
233 			syslog(LOG_ERR, "can not fork: %m");
234 			exit(1);
235 			break;
236 
237 		case 0:
238 			/*
239 			 * Child:
240 			 *
241 			 * return and deliver mail
242 			 */
243 retit:
244 			/*
245 			 * If necessary, acquire the queue and * mail files.
246 			 * If this fails, we probably were raced by another
247 			 * process.
248 			 */
249 			setlogident("%s", it->queueid);
250 			if (acquirespool(it) < 0)
251 				exit(1);
252 			dropspool(queue, it);
253 			return (it);
254 
255 		default:
256 			/*
257 			 * Parent:
258 			 *
259 			 * fork next child
260 			 */
261 			break;
262 		}
263 	}
264 
265 	syslog(LOG_CRIT, "reached dead code");
266 	exit(1);
267 }
268 
269 static void
270 deliver(struct qitem *it)
271 {
272 	int error;
273 	unsigned int backoff = it->remote? MIN_RETRY: MIN_RETRY_LOCAL;
274 	const char *errmsg = "unknown bounce reason";
275 	struct timeval now;
276 	struct stat st;
277 
278 retry:
279 	syslog(LOG_INFO, "trying delivery");
280 
281 	if (it->remote)
282 		error = deliver_remote(it, &errmsg);
283 	else
284 		error = deliver_local(it, &errmsg);
285 
286 	switch (error) {
287 	case 0:
288 		delqueue(it);
289 		syslog(LOG_INFO, "delivery successful");
290 		exit(0);
291 
292 	case 1:
293 		if (stat(it->queuefn, &st) != 0) {
294 			syslog(LOG_ERR, "lost queue file `%s'", it->queuefn);
295 			exit(1);
296 		}
297 		if (gettimeofday(&now, NULL) == 0 &&
298 		    (now.tv_sec - st.st_mtim.tv_sec > MAX_TIMEOUT)) {
299 			asprintf(__DECONST(void *, &errmsg),
300 				 "Could not deliver for the last %d seconds. Giving up.",
301 				 MAX_TIMEOUT);
302 			goto bounce;
303 		}
304 		sleep(backoff);
305 		backoff = backoff * 2 + (
306 #ifdef HAVE_RANDOM
307 			random()
308 #else
309 			rand()
310 #endif
311 			% RETRY_JITTER);
312 		if (backoff > MAX_RETRY)
313 			backoff = MAX_RETRY;
314 		goto retry;
315 
316 	case -1:
317 	default:
318 		break;
319 	}
320 
321 bounce:
322 	bounce(it, errmsg);
323 	/* NOTREACHED */
324 }
325 
326 void
327 run_queue(struct queue *queue)
328 {
329 	struct qitem *it;
330 
331 	if (LIST_EMPTY(&queue->queue))
332 		return;
333 
334 	it = go_background(queue);
335 	deliver(it);
336 	/* NOTREACHED */
337 }
338 
339 static void
340 show_queue(struct queue *queue)
341 {
342 	struct qitem *it;
343 	int locked = 0;	/* XXX */
344 
345 	if (LIST_EMPTY(&queue->queue)) {
346 		printf("Mail queue is empty\n");
347 		return;
348 	}
349 
350 	LIST_FOREACH(it, &queue->queue, next) {
351 		printf("ID\t: %s%s\n"
352 		       "From\t: %s\n"
353 		       "To\t: %s\n",
354 		       it->queueid,
355 		       locked ? "*" : "",
356 		       it->sender, it->addr);
357 
358 		if (LIST_NEXT(it, next) != NULL)
359 			printf("--\n");
360 	}
361 }
362 
363 /*
364  * TODO:
365  *
366  * - alias processing
367  * - use group permissions
368  * - proper sysexit codes
369  */
370 
371 int
372 main(int argc, char **argv)
373 {
374 	char *sender = NULL;
375 	struct queue queue;
376 	int i, ch;
377 	int nodot = 0, doqueue = 0, showq = 0, queue_only = 0;
378 	int recp_from_header = 0;
379 
380 	atexit(deltmp);
381 
382 	bzero(&queue, sizeof(queue));
383 	LIST_INIT(&queue.queue);
384 
385 	if (strcmp(argv[0], "mailq") == 0) {
386 		argv++; argc--;
387 		showq = 1;
388 		if (argc != 0)
389 			errx(1, "invalid arguments");
390 		goto skipopts;
391 	}
392 
393 	opterr = 0;
394 	while ((ch = getopt(argc, argv, ":A:b:B:C:d:Df:F:h:iL:N:no:O:q:r:R:tUV:vX:")) != -1) {
395 		switch (ch) {
396 		case 'A':
397 			/* -AX is being ignored, except for -A{c,m} */
398 			if (optarg[0] == 'c' || optarg[0] == 'm') {
399 				break;
400 			}
401 			/* else FALLTRHOUGH */
402 		case 'b':
403 			/* -bX is being ignored, except for -bp */
404 			if (optarg[0] == 'p') {
405 				showq = 1;
406 				break;
407 			} else if (optarg[0] == 'q') {
408 				queue_only = 1;
409 				break;
410 			}
411 			/* else FALLTRHOUGH */
412 		case 'D':
413 			daemonize = 0;
414 			break;
415 		case 'L':
416 			logident_base = optarg;
417 			break;
418 		case 'f':
419 		case 'r':
420 			sender = optarg;
421 			break;
422 
423 		case 't':
424 			recp_from_header = 1;
425 			break;
426 
427 		case 'o':
428 			/* -oX is being ignored, except for -oi */
429 			if (optarg[0] != 'i')
430 				break;
431 			/* else FALLTRHOUGH */
432 		case 'O':
433 			break;
434 		case 'i':
435 			nodot = 1;
436 			break;
437 
438 		case 'q':
439 			doqueue = 1;
440 			break;
441 
442 		/* Ignored options */
443 		case 'B':
444 		case 'C':
445 		case 'd':
446 		case 'F':
447 		case 'h':
448 		case 'N':
449 		case 'n':
450 		case 'R':
451 		case 'U':
452 		case 'V':
453 		case 'v':
454 		case 'X':
455 			break;
456 
457 		case ':':
458 			if (optopt == 'q') {
459 				doqueue = 1;
460 				break;
461 			}
462 			/* FALLTHROUGH */
463 
464 		default:
465 			fprintf(stderr, "invalid argument: `-%c'\n", optopt);
466 			exit(1);
467 		}
468 	}
469 	argc -= optind;
470 	argv += optind;
471 	opterr = 1;
472 
473 	if (argc != 0 && (showq || doqueue))
474 		errx(1, "sending mail and queue operations are mutually exclusive");
475 
476 	if (showq + doqueue > 1)
477 		errx(1, "conflicting queue operations");
478 
479 skipopts:
480 	if (logident_base == NULL)
481 		logident_base = "dma";
482 	setlogident(NULL);
483 	set_username();
484 
485 	/* XXX fork root here */
486 
487 	parse_conf(CONF_PATH);
488 
489 	if (config.features & VIRTUAL) {
490 		if (config.virtualpath == NULL)
491 			errlogx(1, "no virtuser file specified, but VIRTUAL configured");
492 		parse_virtuser(config.virtualpath);
493 	}
494 
495 	if (config.authpath != NULL)
496 		parse_authfile(config.authpath);
497 
498 	if (showq) {
499 		if (load_queue(&queue) < 0)
500 			errlog(1, "can not load queue");
501 		show_queue(&queue);
502 		return (0);
503 	}
504 
505 	if (doqueue) {
506 		if (load_queue(&queue) < 0)
507 			errlog(1, "can not load queue");
508 		run_queue(&queue);
509 		return (0);
510 	}
511 
512 	if (read_aliases() != 0)
513 		errlog(1, "can not read aliases file `%s'", config.aliases);
514 
515 	if ((sender = set_from(&queue, sender)) == NULL)
516 		errlog(1, NULL);
517 
518 	if (newspoolf(&queue) != 0)
519 		errlog(1, "can not create temp file");
520 
521 	setlogident("%s", queue.id);
522 
523 	for (i = 0; i < argc; i++) {
524 		if (add_recp(&queue, argv[i], 1) != 0)
525 			errlogx(1, "invalid recipient `%s'", argv[i]);
526 	}
527 
528 	if (LIST_EMPTY(&queue.queue) && !recp_from_header)
529 		errlogx(1, "no recipients");
530 
531 	if (readmail(&queue, nodot, recp_from_header) != 0)
532 		errlog(1, "can not read mail");
533 
534 	if (LIST_EMPTY(&queue.queue))
535 		errlogx(1, "no recipients");
536 
537 	if (linkspool(&queue) != 0)
538 		errlog(1, "can not create spools");
539 
540 	/* From here on the mail is safe. */
541 
542 	if (config.features & DEFER || queue_only)
543 		return (0);
544 
545 	run_queue(&queue);
546 
547 	/* NOTREACHED */
548 	return (0);
549 }
550