1 /* $OpenBSD: mailwrapper.c,v 1.22 2015/12/28 16:27:28 jung 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 int main(int, char *[], char *[]); 52 53 static void initarg(struct arglist *); 54 static void addarg(struct arglist *, const char *); 55 56 extern const char *__progname; /* from crt0.o */ 57 58 static void 59 initarg(struct arglist *al) 60 { 61 al->argc = 0; 62 al->maxc = 10; 63 if ((al->argv = calloc(al->maxc, sizeof(char *))) == NULL) 64 err(1, "malloc"); 65 } 66 67 static void 68 addarg(struct arglist *al, const char *arg) 69 { 70 if (al->argc == al->maxc) { 71 al->maxc <<= 1; 72 al->argv = reallocarray(al->argv, al->maxc, sizeof(char *)); 73 if (al->argv == NULL) 74 err(1, "realloc"); 75 } 76 77 al->argv[al->argc++] = (char *)arg; 78 } 79 80 int 81 main(int argc, char *argv[], char *envp[]) 82 { 83 FILE *config; 84 char *line, *cp, *from, *to, *ap; 85 const char *progname; 86 size_t len, lineno = 0; 87 struct arglist al; 88 89 if (pledge("stdio rpath exec", NULL) == -1) 90 err(1, "pledge"); 91 92 /* change __progname to mailwrapper so we get sensible error messages */ 93 progname = __progname; 94 __progname = "mailwrapper"; 95 96 initarg(&al); 97 for (len = 0; len < argc; len++) 98 addarg(&al, argv[len]); 99 100 config = fopen(_PATH_MAILERCONF, "r"); 101 102 if (pledge("stdio exec", NULL) == -1) 103 err(1, "pledge"); 104 105 if (config == NULL) { 106 addarg(&al, NULL); 107 openlog(__progname, 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(1, "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(1, "no mapping in %s", _PATH_MAILERCONF); 120 err(1, "fparseln"); 121 } 122 123 #define WS " \t\n" 124 cp = line; 125 126 cp += strspn(cp, WS); 127 if (cp[0] == '\0') { 128 /* empty line */ 129 free(line); 130 continue; 131 } 132 133 if ((from = strsep(&cp, WS)) == NULL || cp == NULL) 134 goto parse_error; 135 136 cp += strspn(cp, WS); 137 138 if ((to = strsep(&cp, WS)) == NULL) 139 goto parse_error; 140 141 if (strcmp(from, progname) == 0) { 142 for (ap = strsep(&cp, WS); ap != NULL; 143 ap = strsep(&cp, WS)) 144 if (*ap) 145 addarg(&al, ap); 146 break; 147 } 148 149 free(line); 150 } 151 152 (void)fclose(config); 153 154 addarg(&al, NULL); 155 156 execve(to, al.argv, envp); 157 err(1, "cannot exec %s", to); 158 /*NOTREACHED*/ 159 parse_error: 160 errx(1, "parse error in %s at line %lu", 161 _PATH_MAILERCONF, (u_long)lineno); 162 /*NOTREACHED*/ 163 } 164