1 /* $NetBSD: mailwrapper.c,v 1.11 2018/01/23 21:06:25 sevan Exp $ */
2
3 /*
4 * Copyright (c) 1998
5 * Perry E. Metzger. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgment:
17 * This product includes software developed for the NetBSD Project
18 * by Perry E. Metzger.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <err.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include <unistd.h>
39
40 #define _PATH_MAILERCONF "/etc/mailer.conf"
41
42 struct arglist {
43 size_t argc, maxc;
44 const char **argv;
45 };
46
47 static void initarg(struct arglist *);
48 static void addarg(struct arglist *, const char *, int);
49
50 static void
initarg(struct arglist * al)51 initarg(struct arglist *al)
52 {
53 al->argc = 0;
54 al->maxc = 10;
55 if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
56 /*
57 * This (using err("mailwrapper")) is intentional.
58 * Mailwrapper plays ugly games with argv[0] and thus it
59 * is often difficult for people to know that the error
60 * isn't from "mailq" or "sendmail" but from mailwrapper
61 * -- having mailwrapper add an indication that it was really
62 * mailwrapper running was a requested feature.
63 */
64 err(1, "mailwrapper");
65 }
66
67 static void
addarg(struct arglist * al,const char * arg,int copy)68 addarg(struct arglist *al, const char *arg, int copy)
69 {
70 if (al->argc == al->maxc) {
71 al->maxc <<= 1;
72 if ((al->argv = realloc(al->argv,
73 al->maxc * sizeof(char *))) == NULL)
74 err(1, "mailwrapper");
75 }
76 if (copy) {
77 if ((al->argv[al->argc++] = strdup(arg)) == NULL)
78 err(1, "mailwrapper:");
79 } else
80 al->argv[al->argc++] = arg;
81 }
82
83 int
main(int argc,char * argv[],char * envp[])84 main(int argc, char *argv[], char *envp[])
85 {
86 FILE *config;
87 char *line, *cp, *from, *to, *ap;
88 size_t len, lineno = 0;
89 int i;
90 struct arglist al;
91
92 initarg(&al);
93 addarg(&al, argv[0], 0);
94
95 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
96 err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
97
98 for (;;) {
99 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
100 if (feof(config))
101 errx(1, "mailwrapper: no mapping in %s",
102 _PATH_MAILERCONF);
103 err(1, "mailwrapper");
104 }
105
106 #define WS " \t\n"
107 cp = line;
108
109 cp += strspn(cp, WS);
110 if (cp[0] == '\0') {
111 /* empty line */
112 free(line);
113 continue;
114 }
115
116 if ((from = strsep(&cp, WS)) == NULL)
117 goto parse_error;
118
119 cp += strspn(cp, WS);
120
121 if ((to = strsep(&cp, WS)) == NULL)
122 goto parse_error;
123
124 if (strcmp(from, getprogname()) == 0) {
125 for (ap = strsep(&cp, WS); ap != NULL;
126 ap = strsep(&cp, WS))
127 if (*ap)
128 addarg(&al, ap, 0);
129 break;
130 }
131
132 free(line);
133 }
134
135 (void)fclose(config);
136
137 for (i = 1; i < argc; i++)
138 addarg(&al, argv[i], 0);
139
140 addarg(&al, NULL, 0);
141 execve(to, __UNCONST(al.argv), envp);
142 err(1, "mailwrapper: execing %s", to);
143 /*NOTREACHED*/
144 parse_error:
145 errx(1, "mailwrapper: parse error in %s at line %lu",
146 _PATH_MAILERCONF, (u_long)lineno);
147 /*NOTREACHED*/
148 }
149