1 /* $OpenBSD: mailwrapper.c,v 1.18 2007/11/06 14:39:19 otto Exp $ */
2 /* $NetBSD: mailwrapper.c,v 1.9 2003/03/09 08:10:43 mjl 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 <compat.h>
36 #include <err.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <stdlib.h>
41 #include <sysexits.h>
42 #include <syslog.h>
43 #include <limits.h>
44
45 #include "pathnames.h"
46
47 struct arglist {
48 size_t argc, maxc;
49 char **argv;
50 };
51
52 int main(int, char *[], char *[]);
53
54 static void initarg(struct arglist *);
55 static void addarg(struct arglist *, const char *);
56
57 static void
58 initarg(struct arglist *al)
59 {
60 al->argc = 0;
61 al->maxc = 10;
62 if ((al->argv = calloc(al->maxc, sizeof (char *))) == NULL)
63 err(EX_TEMPFAIL, "calloc");
64 }
65
66 static void
67 addarg(struct arglist *al, const char *arg)
68 {
69
70 if (al->argc == al->maxc) {
71 al->maxc <<= 1;
72 al->argv = realloc(al->argv, al->maxc * sizeof (char *));
73 if (al->argv == NULL)
74 err(EX_TEMPFAIL, "realloc");
75 }
76 if (arg == NULL)
77 al->argv[al->argc++] = NULL;
78 else if ((al->argv[al->argc++] = strdup(arg)) == NULL)
79 err(EX_TEMPFAIL, "strdup");
80 }
81
82 int
83 main(int argc, char *argv[], char *envp[])
84 {
85 FILE *config;
86 char *line, *cp, *from, *to, *ap;
87 char progname[PATH_MAX+1];
88 const char *name;
89 size_t len, lineno = 0;
90 int i;
91 struct arglist al;
92
93 /* change __progname to mailwrapper so we get sensible error messages */
94 name = getprogname();
95 if (name) {
96 strncpy(progname, name, sizeof (progname));
97 } else {
98 err(EX_OSERR, "cannot get program name");
99 }
100 setprogname("mailwrapper");
101
102 initarg(&al);
103 addarg(&al, argv[0]);
104
105 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) {
106 addarg(&al, NULL);
107 openlog(getprogname(), LOG_PID, LOG_MAIL);
108 syslog(LOG_INFO, "cannot open %s, using %s as default MTA",
109 _PATH_MAILERCONF, _PATH_DEFAULTMTA);
110 closelog();
111 execve(_PATH_DEFAULTMTA, al.argv, envp);
112 err(EX_OSERR, "cannot exec %s", _PATH_DEFAULTMTA);
113 /*NOTREACHED*/
114 }
115
116 for (;;) {
117 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
118 if (feof(config))
119 errx(EX_CONFIG, "no mapping for %s in %s",
120 progname, _PATH_MAILERCONF);
121 err(EX_CONFIG, "cannot parse line %lu",
122 (ulong_t)lineno);
123 }
124
125 #define WS " \t\n"
126 cp = line;
127
128 cp += strspn(cp, WS);
129 if (cp[0] == '\0') {
130 /* empty line */
131 free(line);
132 continue;
133 }
134
135 if ((from = strsep(&cp, WS)) == NULL || cp == NULL)
136 goto parse_error;
137
138 cp += strspn(cp, WS);
139
140 if ((to = strsep(&cp, WS)) == NULL)
141 goto parse_error;
142
143 if (strcmp(from, progname) == 0) {
144 for (ap = strsep(&cp, WS); ap != NULL;
145 ap = strsep(&cp, WS)) {
146 if (*ap)
147 addarg(&al, ap);
148 }
149 break;
150 }
151
152 free(line);
153 }
154
155 (void) fclose(config);
156
157 for (i = 1; i < argc; i++)
158 addarg(&al, argv[i]);
159
160 addarg(&al, NULL);
161 execve(to, al.argv, envp);
162 err(EX_OSERR, "cannot exec %s", to);
163 /*NOTREACHED*/
164 parse_error:
165 errx(EX_CONFIG, "parse error in %s at line %lu",
166 _PATH_MAILERCONF, (ulong_t)lineno);
167 /*NOTREACHED*/
168 return (0);
169 }