1 /* $OpenBSD: mailwrapper.c,v 1.23 2017/06/14 16:32:11 anton Exp $ */
2 /* $NetBSD: mailwrapper.c,v 1.2 1999/02/20 22:10:07 thorpej 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 <err.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <stdlib.h>
39 #include <syslog.h>
40 #include <unistd.h>
41 #include <util.h>
42
43 #define _PATH_MAILERCONF "/etc/mailer.conf"
44 #define _PATH_DEFAULTMTA "/usr/sbin/smtpctl"
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 *, const char *);
53
54 extern const char *__progname; /* from crt0.o */
55
56 static void
initarg(struct arglist * al)57 initarg(struct arglist *al)
58 {
59 al->argc = 0;
60 al->maxc = 10;
61 if ((al->argv = calloc(al->maxc, sizeof(char *))) == NULL)
62 err(1, "malloc");
63 }
64
65 static void
addarg(struct arglist * al,const char * arg)66 addarg(struct arglist *al, const char *arg)
67 {
68 if (al->argc == al->maxc) {
69 al->maxc <<= 1;
70 al->argv = reallocarray(al->argv, al->maxc, sizeof(char *));
71 if (al->argv == NULL)
72 err(1, "realloc");
73 }
74
75 al->argv[al->argc++] = (char *)arg;
76 }
77
78 int
main(int argc,char * argv[])79 main(int argc, char *argv[])
80 {
81 FILE *config;
82 char *line, *cp, *from, *to, *ap;
83 const char *progname;
84 size_t len, lineno = 0;
85 struct arglist al;
86
87 if (pledge("stdio rpath exec", NULL) == -1)
88 err(1, "pledge");
89
90 /* change __progname to mailwrapper so we get sensible error messages */
91 progname = __progname;
92 __progname = "mailwrapper";
93
94 initarg(&al);
95 for (len = 0; len < argc; len++)
96 addarg(&al, argv[len]);
97
98 config = fopen(_PATH_MAILERCONF, "r");
99
100 if (pledge("stdio exec", NULL) == -1)
101 err(1, "pledge");
102
103 if (config == NULL) {
104 addarg(&al, NULL);
105 openlog(__progname, LOG_PID, LOG_MAIL);
106 syslog(LOG_INFO, "cannot open %s, using %s as default MTA",
107 _PATH_MAILERCONF, _PATH_DEFAULTMTA);
108 closelog();
109 execv(_PATH_DEFAULTMTA, al.argv);
110 err(1, "cannot exec %s", _PATH_DEFAULTMTA);
111 /*NOTREACHED*/
112 }
113
114 for (;;) {
115 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
116 if (feof(config))
117 errx(1, "no mapping in %s", _PATH_MAILERCONF);
118 err(1, "fparseln");
119 }
120
121 #define WS " \t\n"
122 cp = line;
123
124 cp += strspn(cp, WS);
125 if (cp[0] == '\0') {
126 /* empty line */
127 free(line);
128 continue;
129 }
130
131 if ((from = strsep(&cp, WS)) == NULL || cp == NULL)
132 goto parse_error;
133
134 cp += strspn(cp, WS);
135
136 if ((to = strsep(&cp, WS)) == NULL)
137 goto parse_error;
138
139 if (strcmp(from, progname) == 0) {
140 for (ap = strsep(&cp, WS); ap != NULL;
141 ap = strsep(&cp, WS))
142 if (*ap)
143 addarg(&al, ap);
144 break;
145 }
146
147 free(line);
148 }
149
150 (void)fclose(config);
151
152 addarg(&al, NULL);
153
154 execv(to, al.argv);
155 err(1, "cannot exec %s", to);
156 /*NOTREACHED*/
157 parse_error:
158 errx(1, "parse error in %s at line %lu",
159 _PATH_MAILERCONF, (u_long)lineno);
160 /*NOTREACHED*/
161 }
162