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 1.3 2003/11/03 19:31:38 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(al) 63 struct arglist *al; 64 { 65 al->argc = 0; 66 al->maxc = 10; 67 if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL) 68 err(1, NULL); 69 } 70 71 static void 72 addarg(al, arg, copy) 73 struct arglist *al; 74 const char *arg; 75 int copy; 76 { 77 char **argv2; 78 79 if (al->argc == al->maxc) { 80 al->maxc <<= 1; 81 82 if ((argv2 = realloc(al->argv, 83 al->maxc * sizeof(char *))) == NULL) { 84 if (al->argv) 85 free(al->argv); 86 al->argv = NULL; 87 err(1, NULL); 88 } else { 89 al->argv = argv2; 90 } 91 } 92 if (copy) { 93 if ((al->argv[al->argc++] = strdup(arg)) == NULL) 94 err(1, NULL); 95 } else 96 al->argv[al->argc++] = (char *)arg; 97 } 98 99 static void 100 freearg(al, copy) 101 struct arglist *al; 102 int copy; 103 { 104 size_t i; 105 if (copy) 106 for (i = 0; i < al->argc; i++) 107 free(al->argv[i]); 108 free(al->argv); 109 } 110 111 int 112 main(argc, argv, envp) 113 int argc; 114 char *argv[]; 115 char *envp[]; 116 { 117 FILE *config; 118 char *line, *cp, *from, *to, *ap; 119 size_t len, lineno = 0; 120 struct arglist al; 121 122 initarg(&al); 123 for (len = 0; len < argc; len++) 124 addarg(&al, argv[len], 0); 125 126 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) { 127 addarg(&al, NULL, 0); 128 openlog("mailwrapper", LOG_PID, LOG_MAIL); 129 syslog(LOG_INFO, "can't open %s, using %s as default MTA", 130 _PATH_MAILERCONF, _PATH_DEFAULTMTA); 131 closelog(); 132 execve(_PATH_DEFAULTMTA, al.argv, envp); 133 freearg(&al, 0); 134 err(1, "execing %s", _PATH_DEFAULTMTA); 135 /*NOTREACHED*/ 136 } 137 138 for (;;) { 139 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 140 if (feof(config)) 141 errx(1, "no mapping in %s", _PATH_MAILERCONF); 142 err(1, "can't parse line %lu", (u_long)lineno); 143 } 144 145 #define WS " \t\n" 146 cp = line; 147 148 cp += strspn(cp, WS); 149 if (cp[0] == '\0') { 150 /* empty line */ 151 free(line); 152 continue; 153 } 154 155 if ((from = strsep(&cp, WS)) == NULL) 156 goto parse_error; 157 158 cp += strspn(cp, WS); 159 160 if ((to = strsep(&cp, WS)) == NULL) 161 goto parse_error; 162 163 if (strcmp(from, __progname) == 0) { 164 for (ap = strsep(&cp, WS); ap != NULL; 165 ap = strsep(&cp, WS)) 166 if (*ap) 167 addarg(&al, ap, 0); 168 break; 169 } 170 171 free(line); 172 } 173 174 (void)fclose(config); 175 176 addarg(&al, NULL, 0); 177 execve(to, al.argv, envp); 178 freearg(&al, 0); 179 warn("execing %s", to); 180 free(line); 181 exit(1); 182 /*NOTREACHED*/ 183 parse_error: 184 freearg(&al, 0); 185 free(line); 186 errx(1, "parse error in %s at line %lu", 187 _PATH_MAILERCONF, (u_long)lineno); 188 /*NOTREACHED*/ 189 } 190