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 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 <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <err.h> 39 #include <stdio.h> 40 #include <string.h> 41 #include <stdlib.h> 42 #include <unistd.h> 43 #include <libutil.h> 44 #include <syslog.h> 45 #include <stdarg.h> 46 47 #include "pathnames.h" 48 49 struct arglist { 50 size_t argc, maxc; 51 char **argv; 52 }; 53 54 int main(int, char *[], char *[]); 55 56 static void initarg(struct arglist *); 57 static void addarg(struct arglist *, const char *, int); 58 static void freearg(struct arglist *, int); 59 60 extern const char *__progname; /* from crt0.o */ 61 62 static void 63 initarg(al) 64 struct arglist *al; 65 { 66 al->argc = 0; 67 al->maxc = 10; 68 if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL) 69 err(1, NULL); 70 } 71 72 static void 73 addarg(al, arg, copy) 74 struct arglist *al; 75 const char *arg; 76 int copy; 77 { 78 char **argv2; 79 80 if (al->argc == al->maxc) { 81 al->maxc <<= 1; 82 83 if ((argv2 = realloc(al->argv, 84 al->maxc * sizeof(char *))) == NULL) { 85 if (al->argv) 86 free(al->argv); 87 al->argv = NULL; 88 err(1, NULL); 89 } else { 90 al->argv = argv2; 91 } 92 } 93 if (copy) { 94 if ((al->argv[al->argc++] = strdup(arg)) == NULL) 95 err(1, NULL); 96 } else 97 al->argv[al->argc++] = (char *)arg; 98 } 99 100 static void 101 freearg(al, copy) 102 struct arglist *al; 103 int copy; 104 { 105 size_t i; 106 if (copy) 107 for (i = 0; i < al->argc; i++) 108 free(al->argv[i]); 109 free(al->argv); 110 } 111 112 int 113 main(argc, argv, envp) 114 int argc; 115 char *argv[]; 116 char *envp[]; 117 { 118 FILE *config; 119 char *line, *cp, *from, *to, *ap; 120 size_t len, lineno = 0; 121 struct arglist al; 122 123 initarg(&al); 124 for (len = 0; len < argc; len++) 125 addarg(&al, argv[len], 0); 126 127 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) { 128 addarg(&al, NULL, 0); 129 openlog("mailwrapper", LOG_PID, LOG_MAIL); 130 syslog(LOG_INFO, "can't open %s, using %s as default MTA", 131 _PATH_MAILERCONF, _PATH_DEFAULTMTA); 132 closelog(); 133 execve(_PATH_DEFAULTMTA, al.argv, envp); 134 freearg(&al, 0); 135 err(1, "execing %s", _PATH_DEFAULTMTA); 136 /*NOTREACHED*/ 137 } 138 139 for (;;) { 140 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 141 if (feof(config)) 142 errx(1, "no mapping in %s", _PATH_MAILERCONF); 143 err(1, "can't parse line %lu", (u_long)lineno); 144 } 145 146 #define WS " \t\n" 147 cp = line; 148 149 cp += strspn(cp, WS); 150 if (cp[0] == '\0') { 151 /* empty line */ 152 free(line); 153 continue; 154 } 155 156 if ((from = strsep(&cp, WS)) == NULL) 157 goto parse_error; 158 159 cp += strspn(cp, WS); 160 161 if ((to = strsep(&cp, WS)) == NULL) 162 goto parse_error; 163 164 if (strcmp(from, __progname) == 0) { 165 for (ap = strsep(&cp, WS); ap != NULL; 166 ap = strsep(&cp, WS)) 167 if (*ap) 168 addarg(&al, ap, 0); 169 break; 170 } 171 172 free(line); 173 } 174 175 (void)fclose(config); 176 177 addarg(&al, NULL, 0); 178 execve(to, al.argv, envp); 179 freearg(&al, 0); 180 warn("execing %s", to); 181 free(line); 182 exit(1); 183 /*NOTREACHED*/ 184 parse_error: 185 freearg(&al, 0); 186 free(line); 187 errx(1, "parse error in %s at line %lu", 188 _PATH_MAILERCONF, (u_long)lineno); 189 /*NOTREACHED*/ 190 } 191