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 * SPDX-License-Identifier: BSD-4-Clause 6 * 7 * Copyright (c) 1998 8 * Perry E. Metzger. All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgment: 20 * This product includes software developed for the NetBSD Project 21 * by Perry E. Metzger. 22 * 4. The name of the author may not be used to endorse or promote products 23 * derived from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 #include <sys/param.h> 39 40 #include <err.h> 41 #include <paths.h> 42 #include <stdio.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include <stdlib.h> 46 #include <libutil.h> 47 #include <sysexits.h> 48 #include <syslog.h> 49 50 #include "pathnames.h" 51 52 struct arglist { 53 size_t argc, maxc; 54 char **argv; 55 }; 56 57 int main(int, char *[], char *[]); 58 59 static void initarg(struct arglist *); 60 static void addarg(struct arglist *, const char *); 61 62 static void 63 initarg(struct arglist *al) 64 { 65 al->argc = 0; 66 al->maxc = 10; 67 if ((al->argv = calloc(al->maxc, sizeof(char *))) == NULL) 68 err(EX_TEMPFAIL, "calloc"); 69 } 70 71 static void 72 addarg(struct arglist *al, const char *arg) 73 { 74 75 if (al->argc == al->maxc) { 76 al->maxc <<= 1; 77 al->argv = realloc(al->argv, al->maxc * sizeof(char *)); 78 if (al->argv == NULL) 79 err(EX_TEMPFAIL, "realloc"); 80 } 81 if (arg == NULL) 82 al->argv[al->argc++] = NULL; 83 else if ((al->argv[al->argc++] = strdup(arg)) == NULL) 84 err(EX_TEMPFAIL, "strdup"); 85 } 86 87 int 88 main(int argc, char *argv[], char *envp[]) 89 { 90 FILE *config; 91 char *line, *cp, *from, *to, *ap; 92 const char *progname; 93 char localmailerconf[MAXPATHLEN]; 94 const char *mailerconf; 95 size_t len, lineno = 0; 96 int i; 97 struct arglist al; 98 99 /* change __progname to mailwrapper so we get sensible error messages */ 100 progname = getprogname(); 101 setprogname("mailwrapper"); 102 103 initarg(&al); 104 addarg(&al, argv[0]); 105 106 snprintf(localmailerconf, MAXPATHLEN, "%s/etc/mail/mailer.conf", 107 getlocalbase()); 108 109 mailerconf = localmailerconf; 110 if ((config = fopen(localmailerconf, "r")) == NULL) 111 mailerconf = _PATH_MAILERCONF; 112 113 if (config == NULL && ((config = fopen(mailerconf, "r")) == NULL)) { 114 addarg(&al, NULL); 115 openlog(getprogname(), LOG_PID, LOG_MAIL); 116 syslog(LOG_INFO, "cannot open %s, using %s as default MTA", 117 mailerconf, _PATH_DEFAULTMTA); 118 closelog(); 119 execve(_PATH_DEFAULTMTA, al.argv, envp); 120 err(EX_OSERR, "cannot exec %s", _PATH_DEFAULTMTA); 121 /*NOTREACHED*/ 122 } 123 124 for (;;) { 125 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 126 if (feof(config)) 127 errx(EX_CONFIG, "no mapping in %s", mailerconf); 128 err(EX_CONFIG, "cannot parse line %lu", (u_long)lineno); 129 } 130 131 #define WS " \t\n" 132 cp = line; 133 134 cp += strspn(cp, WS); 135 if (cp[0] == '\0') { 136 /* empty line */ 137 free(line); 138 continue; 139 } 140 141 if ((from = strsep(&cp, WS)) == NULL || cp == NULL) 142 goto parse_error; 143 144 cp += strspn(cp, WS); 145 146 if ((to = strsep(&cp, WS)) == NULL) 147 goto parse_error; 148 149 if (strcmp(from, progname) == 0) { 150 for (ap = strsep(&cp, WS); ap != NULL; 151 ap = strsep(&cp, WS)) { 152 if (*ap) 153 addarg(&al, ap); 154 } 155 break; 156 } 157 158 free(line); 159 } 160 161 (void)fclose(config); 162 163 for (i = 1; i < argc; i++) 164 addarg(&al, argv[i]); 165 166 addarg(&al, NULL); 167 execve(to, al.argv, envp); 168 err(EX_OSERR, "cannot exec %s", to); 169 /*NOTREACHED*/ 170 parse_error: 171 errx(EX_CONFIG, "parse error in %s at line %lu", 172 mailerconf, (u_long)lineno); 173 /*NOTREACHED*/ 174 } 175