mailwrapper.c revision 77679 
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/* $FreeBSD: head/usr.sbin/mailwrapper/mailwrapper.c 77679 2001-06-04 04:22:57Z paul $ */
4
5/*
6 * Copyright (c) 1998
7 * 	Perry E. Metzger.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
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 the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgment:
19 *	This product includes software developed for the NetBSD Project
20 *	by Perry E. Metzger.
21 * 4. The name of the author may not be used to endorse or promote products
22 *    derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36#include <err.h>
37#include <stdio.h>
38#include <string.h>
39#include <stdlib.h>
40#include <unistd.h>
41#include <libutil.h>
42#include <syslog.h>
43#include <stdarg.h>
44
45#include "pathnames.h"
46
47struct arglist {
48	size_t argc, maxc;
49	char **argv;
50};
51
52int main __P((int, char *[], char *[]));
53
54static void initarg __P((struct arglist *));
55static void addarg __P((struct arglist *, const char *, int));
56static void freearg __P((struct arglist *, int));
57
58extern const char *__progname;	/* from crt0.o */
59
60static void
61initarg(al)
62	struct arglist *al;
63{
64	al->argc = 0;
65	al->maxc = 10;
66	if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
67		err(1, NULL);
68}
69
70static void
71addarg(al, arg, copy)
72	struct arglist *al;
73	const char *arg;
74	int copy;
75{
76	char **argv2;
77
78	if (al->argc == al->maxc) {
79		al->maxc <<= 1;
80
81		if ((argv2 = realloc(al->argv,
82		    al->maxc * sizeof(char *))) == NULL) {
83			if (al->argv)
84				free(al->argv);
85			al->argv = NULL;
86			err(1, NULL);
87		} else {
88			al->argv = argv2;
89		}
90	}
91	if (copy) {
92		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
93			err(1, NULL);
94	} else
95		al->argv[al->argc++] = (char *)arg;
96}
97
98static void
99freearg(al, copy)
100	struct arglist *al;
101	int copy;
102{
103	size_t i;
104	if (copy)
105		for (i = 0; i < al->argc; i++)
106			free(al->argv[i]);
107	free(al->argv);
108}
109
110int
111main(argc, argv, envp)
112	int argc;
113	char *argv[];
114	char *envp[];
115{
116	FILE *config;
117	char *line, *cp, *from, *to, *ap;
118	size_t len, lineno = 0;
119	struct arglist al;
120
121	initarg(&al);
122	for (len = 0; len < argc; len++)
123		addarg(&al, argv[len], 0);
124
125	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) {
126		addarg(&al, NULL, 0);
127		openlog("mailwrapper", LOG_PID, LOG_MAIL);
128		syslog(LOG_INFO, "can't open %s, using %s as default MTA",
129		    _PATH_MAILERCONF, _PATH_DEFAULTMTA);
130		closelog();
131		execve(_PATH_DEFAULTMTA, al.argv, envp);
132		freearg(&al, 0);
133		free(line);
134		err(1, "execing %s", _PATH_DEFAULTMTA);
135		/*NOTREACHED*/
136	}
137
138	for (;;) {
139		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
140			if (feof(config))
141				errx(1, "no mapping in %s", _PATH_MAILERCONF);
142			err(1, "can't parse line %lu", (u_long)lineno);
143		}
144
145#define	WS	" \t\n"
146		cp = line;
147
148		cp += strspn(cp, WS);
149		if (cp[0] == '\0') {
150			/* empty line */
151			free(line);
152			continue;
153		}
154
155		if ((from = strsep(&cp, WS)) == NULL)
156			goto parse_error;
157
158		cp += strspn(cp, WS);
159
160		if ((to = strsep(&cp, WS)) == NULL)
161			goto parse_error;
162
163		if (strcmp(from, __progname) == 0) {
164			for (ap = strsep(&cp, WS); ap != NULL;
165			    ap = strsep(&cp, WS))
166			    if (*ap)
167				    addarg(&al, ap, 0);
168			break;
169		}
170
171		free(line);
172	}
173
174	(void)fclose(config);
175
176	addarg(&al, NULL, 0);
177	execve(to, al.argv, envp);
178	freearg(&al, 0);
179	warn("execing %s", to);
180	free(line);
181	exit(1);
182	/*NOTREACHED*/
183parse_error:
184	freearg(&al, 0);
185	free(line);
186	errx(1, "parse error in %s at line %lu",
187	    _PATH_MAILERCONF, (u_long)lineno);
188	/*NOTREACHED*/
189}
190