xref: /openbsd/usr.sbin/smtpd/forward.c (revision 8529ddd3)
1 /*	$OpenBSD: forward.c,v 1.36 2015/01/20 17:37:54 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/tree.h>
22 #include <sys/socket.h>
23 #include <sys/stat.h>
24 
25 #include <ctype.h>
26 #include <event.h>
27 #include <imsg.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <util.h>
32 #include <unistd.h>
33 #include <limits.h>
34 
35 #include "smtpd.h"
36 #include "log.h"
37 
38 #define	MAX_FORWARD_SIZE	(4 * 1024)
39 #define	MAX_EXPAND_NODES	(100)
40 
41 int
42 forwards_get(int fd, struct expand *expand)
43 {
44 	FILE	       *fp = NULL;
45 	char	       *line = NULL;
46 	size_t		len;
47 	size_t		lineno;
48 	size_t		save;
49 	int		ret;
50 	struct stat	sb;
51 
52 	ret = -1;
53 	if (fstat(fd, &sb) == -1)
54 		goto end;
55 
56 	/* if it's empty just pretend that no expansion took place */
57 	if (sb.st_size == 0) {
58 		log_info("info: forward file is empty");
59 		ret = 0;
60 		goto end;
61 	}
62 
63 	/* over MAX_FORWARD_SIZE, temporarily fail */
64 	if (sb.st_size >= MAX_FORWARD_SIZE) {
65 		log_info("info: forward file exceeds max size");
66 		goto end;
67 	}
68 
69 	if ((fp = fdopen(fd, "r")) == NULL) {
70 		log_warn("warn: fdopen failure in forwards_get()");
71 		goto end;
72 	}
73 
74 	lineno = 0;
75 	save = expand->nb_nodes;
76 	while ((line = fparseln(fp, &len, &lineno, NULL, 0)) != NULL) {
77 		if (! expand_line(expand, line, 0)) {
78 			log_info("info: parse error in forward file");
79 			goto end;
80 		}
81 		if (expand->nb_nodes > MAX_EXPAND_NODES) {
82 			log_info("info: forward file expanded too many nodes");
83 			goto end;
84 		}
85 		free(line);
86 	}
87 
88 	ret = expand->nb_nodes > save ? 1 : 0;
89 
90 end:
91 	if (line)
92 		free(line);
93 	if (fp)
94 		fclose(fp);
95 	else
96 		close(fd);
97 	return ret;
98 }
99