1 /* $OpenBSD: mailwrapper.c,v 1.16 2004/07/06 03:38:14 millert Exp $ */
2 /* $NetBSD: mailwrapper.c,v 1.9 2003/03/09 08:10:43 mjl Exp $ */
3 /* $FreeBSD: src/usr.sbin/mailwrapper/mailwrapper.c,v 1.9 2003/07/06 12:44:11 charnier Exp $ */
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 <syslog.h>
42 #include <stdarg.h>
43
44 #include "pathnames.h"
45
46 struct arglist {
47 size_t argc, maxc;
48 char **argv;
49 };
50
51 static void initarg(struct arglist *);
52 static void addarg(struct arglist *, char *, int);
53
54 static void
initarg(struct arglist * al)55 initarg(struct arglist *al)
56 {
57 al->argc = 0;
58 al->maxc = 10;
59 if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
60 err(1, NULL);
61 }
62
63 static void
addarg(struct arglist * al,char * arg,int copy)64 addarg(struct arglist *al, char *arg, int copy)
65 {
66 if (al->argc == al->maxc) {
67 al->maxc <<= 1;
68 al->argv = realloc(al->argv, al->maxc * sizeof(char *));
69 if (al->argv == NULL)
70 err(1, NULL);
71 }
72 if (copy) {
73 if ((al->argv[al->argc++] = strdup(arg)) == NULL)
74 err(1, NULL);
75 } else
76 al->argv[al->argc++] = arg;
77 }
78
79 int
main(int argc,char ** argv,char ** envp)80 main(int argc, char **argv, char **envp)
81 {
82 FILE *config;
83 char *line, *cp, *from, *to, *ap;
84 const char *progname;
85 size_t len, lineno = 0;
86 int i;
87 struct arglist al;
88
89 /* change progname to mailwrapper so we get sensible error messages */
90 progname = getprogname();
91 setprogname("mailwrapper");
92
93 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) {
94 openlog("mailwrapper", LOG_PID, LOG_MAIL);
95 syslog(LOG_INFO, "can't open %s, using %s as default MTA",
96 _PATH_MAILERCONF, _PATH_DEFAULTMTA);
97 closelog();
98 execve(_PATH_DEFAULTMTA, argv, envp);
99 err(1, "cannot exec %s", _PATH_DEFAULTMTA);
100 /*NOTREACHED*/
101 }
102
103 initarg(&al);
104 addarg(&al, argv[0], 0);
105
106 for (;;) {
107 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
108 if (feof(config))
109 errx(1, "no mapping in %s", _PATH_MAILERCONF);
110 err(1, NULL);
111 }
112
113 #define WS " \t\n"
114 cp = line;
115
116 cp += strspn(cp, WS);
117 if (cp[0] == '\0') {
118 /* empty line */
119 free(line);
120 continue;
121 }
122
123 if ((from = strsep(&cp, WS)) == NULL)
124 goto parse_error;
125
126 cp += strspn(cp, WS);
127
128 if ((to = strsep(&cp, WS)) == NULL)
129 goto parse_error;
130
131 if (strcmp(from, progname) == 0) {
132 for (ap = strsep(&cp, WS); ap != NULL;
133 ap = strsep(&cp, WS))
134 if (*ap)
135 addarg(&al, ap, 0);
136 break;
137 }
138
139 free(line);
140 }
141
142 fclose(config);
143
144 for (i = 1; i < argc; i++)
145 addarg(&al, argv[i], 0);
146 addarg(&al, NULL, 0);
147
148 execve(to, al.argv, envp);
149 err(1, "cannot exec %s", to);
150 /*NOTREACHED*/
151 parse_error:
152 errx(1, "parse error in %s at line %lu",
153 _PATH_MAILERCONF, (u_long)lineno);
154 /*NOTREACHED*/
155 }
156