mailwrapper.c revision 117280 
1/*	$OpenBSD: mailwrapper.c,v 1.6 1999/12/17 05:06:28 mickey Exp $	*/
2/*	$NetBSD: mailwrapper.c,v 1.3 1999/05/29 18:18:15 christos Exp $	*/
3
4/*
5 * Copyright (c) 1998
6 * 	Perry E. Metzger.  All rights reserved.
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 * 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 the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgment:
18 *	This product includes software developed for the NetBSD Project
19 *	by Perry E. Metzger.
20 * 4. The name of the author may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/usr.sbin/mailwrapper/mailwrapper.c 117280 2003-07-06 12:44:11Z charnier $");
37
38#include <err.h>
39#include <stdio.h>
40#include <string.h>
41#include <stdlib.h>
42#include <unistd.h>
43#include <libutil.h>
44#include <syslog.h>
45#include <stdarg.h>
46
47#include "pathnames.h"
48
49struct arglist {
50	size_t argc, maxc;
51	char **argv;
52};
53
54int main(int, char *[], char *[]);
55
56static void initarg(struct arglist *);
57static void addarg(struct arglist *, const char *, int);
58static void freearg(struct arglist *, int);
59
60extern const char *__progname;	/* from crt0.o */
61
62static void
63initarg(al)
64	struct arglist *al;
65{
66	al->argc = 0;
67	al->maxc = 10;
68	if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
69		err(1, NULL);
70}
71
72static void
73addarg(al, arg, copy)
74	struct arglist *al;
75	const char *arg;
76	int copy;
77{
78	char **argv2;
79
80	if (al->argc == al->maxc) {
81		al->maxc <<= 1;
82
83		if ((argv2 = realloc(al->argv,
84		    al->maxc * sizeof(char *))) == NULL) {
85			if (al->argv)
86				free(al->argv);
87			al->argv = NULL;
88			err(1, NULL);
89		} else {
90			al->argv = argv2;
91		}
92	}
93	if (copy) {
94		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
95			err(1, NULL);
96	} else
97		al->argv[al->argc++] = (char *)arg;
98}
99
100static void
101freearg(al, copy)
102	struct arglist *al;
103	int copy;
104{
105	size_t i;
106	if (copy)
107		for (i = 0; i < al->argc; i++)
108			free(al->argv[i]);
109	free(al->argv);
110}
111
112int
113main(argc, argv, envp)
114	int argc;
115	char *argv[];
116	char *envp[];
117{
118	FILE *config;
119	char *line, *cp, *from, *to, *ap;
120	size_t len, lineno = 0;
121	struct arglist al;
122
123	initarg(&al);
124	for (len = 0; len < argc; len++)
125		addarg(&al, argv[len], 0);
126
127	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) {
128		addarg(&al, NULL, 0);
129		openlog("mailwrapper", LOG_PID, LOG_MAIL);
130		syslog(LOG_INFO, "can't open %s, using %s as default MTA",
131		    _PATH_MAILERCONF, _PATH_DEFAULTMTA);
132		closelog();
133		execve(_PATH_DEFAULTMTA, al.argv, envp);
134		freearg(&al, 0);
135		err(1, "execing %s", _PATH_DEFAULTMTA);
136		/*NOTREACHED*/
137	}
138
139	for (;;) {
140		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
141			if (feof(config))
142				errx(1, "no mapping in %s", _PATH_MAILERCONF);
143			err(1, "can't parse line %lu", (u_long)lineno);
144		}
145
146#define	WS	" \t\n"
147		cp = line;
148
149		cp += strspn(cp, WS);
150		if (cp[0] == '\0') {
151			/* empty line */
152			free(line);
153			continue;
154		}
155
156		if ((from = strsep(&cp, WS)) == NULL)
157			goto parse_error;
158
159		cp += strspn(cp, WS);
160
161		if ((to = strsep(&cp, WS)) == NULL)
162			goto parse_error;
163
164		if (strcmp(from, __progname) == 0) {
165			for (ap = strsep(&cp, WS); ap != NULL;
166			    ap = strsep(&cp, WS))
167			    if (*ap)
168				    addarg(&al, ap, 0);
169			break;
170		}
171
172		free(line);
173	}
174
175	(void)fclose(config);
176
177	addarg(&al, NULL, 0);
178	execve(to, al.argv, envp);
179	freearg(&al, 0);
180	warn("execing %s", to);
181	free(line);
182	exit(1);
183	/*NOTREACHED*/
184parse_error:
185	freearg(&al, 0);
186	free(line);
187	errx(1, "parse error in %s at line %lu",
188	    _PATH_MAILERCONF, (u_long)lineno);
189	/*NOTREACHED*/
190}
191