1 /* $OpenBSD: mailwrapper.c,v 1.6 1999/12/17 05:06:28 mickey Exp $ */ 2 /* $NetBSD: mailwrapper.c,v 1.3 1999/05/29 18:18:15 christos Exp $ */ 3 /* $FreeBSD: src/usr.sbin/mailwrapper/mailwrapper.c,v 1.4.2.3 2001/10/01 12:52:47 dd Exp $ */ 4 /* $DragonFly: src/usr.sbin/mailwrapper/mailwrapper.c,v 1.4 2003/11/22 11:38:13 eirikn Exp $ */ 5 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 <err.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <stdlib.h> 41 #include <unistd.h> 42 #include <libutil.h> 43 #include <syslog.h> 44 #include <stdarg.h> 45 46 #include "pathnames.h" 47 48 struct arglist { 49 size_t argc, maxc; 50 char **argv; 51 }; 52 53 int main(int, char *[], char *[]); 54 55 static void initarg(struct arglist *); 56 static void addarg(struct arglist *, const char *, int); 57 static void freearg(struct arglist *, int); 58 59 extern const char *__progname; /* from crt0.o */ 60 61 static void 62 initarg(struct arglist *al) 63 { 64 al->argc = 0; 65 al->maxc = 10; 66 if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL) 67 err(1, NULL); 68 } 69 70 static void 71 addarg(struct arglist *al, const char *arg, int copy) 72 { 73 char **argv2; 74 75 if (al->argc == al->maxc) { 76 al->maxc <<= 1; 77 78 if ((argv2 = realloc(al->argv, 79 al->maxc * sizeof(char *))) == NULL) { 80 if (al->argv) 81 free(al->argv); 82 al->argv = NULL; 83 err(1, NULL); 84 } else { 85 al->argv = argv2; 86 } 87 } 88 if (copy) { 89 if ((al->argv[al->argc++] = strdup(arg)) == NULL) 90 err(1, NULL); 91 } else 92 al->argv[al->argc++] = (char *)arg; 93 } 94 95 static void 96 freearg(struct arglist *al, int copy) 97 { 98 size_t i; 99 if (copy) 100 for (i = 0; i < al->argc; i++) 101 free(al->argv[i]); 102 free(al->argv); 103 } 104 105 int 106 main(int argc, char **argv, char **envp) 107 { 108 FILE *config; 109 char *line, *cp, *from, *to, *ap; 110 size_t len, lineno = 0; 111 struct arglist al; 112 113 initarg(&al); 114 for (len = 0; len < argc; len++) 115 addarg(&al, argv[len], 0); 116 117 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) { 118 addarg(&al, NULL, 0); 119 openlog("mailwrapper", LOG_PID, LOG_MAIL); 120 syslog(LOG_INFO, "can't open %s, using %s as default MTA", 121 _PATH_MAILERCONF, _PATH_DEFAULTMTA); 122 closelog(); 123 execve(_PATH_DEFAULTMTA, al.argv, envp); 124 freearg(&al, 0); 125 err(1, "execing %s", _PATH_DEFAULTMTA); 126 /*NOTREACHED*/ 127 } 128 129 for (;;) { 130 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 131 if (feof(config)) 132 errx(1, "no mapping in %s", _PATH_MAILERCONF); 133 err(1, "can't parse line %lu", (u_long)lineno); 134 } 135 136 #define WS " \t\n" 137 cp = line; 138 139 cp += strspn(cp, WS); 140 if (cp[0] == '\0') { 141 /* empty line */ 142 free(line); 143 continue; 144 } 145 146 if ((from = strsep(&cp, WS)) == NULL) 147 goto parse_error; 148 149 cp += strspn(cp, WS); 150 151 if ((to = strsep(&cp, WS)) == NULL) 152 goto parse_error; 153 154 if (strcmp(from, __progname) == 0) { 155 for (ap = strsep(&cp, WS); ap != NULL; 156 ap = strsep(&cp, WS)) 157 if (*ap) 158 addarg(&al, ap, 0); 159 break; 160 } 161 162 free(line); 163 } 164 165 (void)fclose(config); 166 167 addarg(&al, NULL, 0); 168 execve(to, al.argv, envp); 169 freearg(&al, 0); 170 warn("execing %s", to); 171 free(line); 172 exit(1); 173 /*NOTREACHED*/ 174 parse_error: 175 freearg(&al, 0); 176 free(line); 177 errx(1, "parse error in %s at line %lu", 178 _PATH_MAILERCONF, (u_long)lineno); 179 /*NOTREACHED*/ 180 } 181