1 /* $OpenBSD: mailwrapper.c,v 1.15 2003/03/09 01:24:26 millert 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/libexec/sendmail/sendmail" 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 *, int); 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 = malloc(al->maxc * sizeof(char *))) == NULL) 64 err(1, "malloc"); 65 } 66 67 static void 68 addarg(struct arglist *al, const char *arg, int copy) 69 { 70 char **argv2; 71 72 if (al->argc == al->maxc) { 73 al->maxc <<= 1; 74 75 if ((argv2 = realloc(al->argv, 76 al->maxc * sizeof(char *))) == NULL) { 77 if (al->argv) 78 free(al->argv); 79 al->argv = NULL; 80 err(1, "realloc"); 81 } else { 82 al->argv = argv2; 83 } 84 } 85 if (copy) { 86 if ((al->argv[al->argc++] = strdup(arg)) == NULL) 87 err(1, "strdup"); 88 } else 89 al->argv[al->argc++] = (char *)arg; 90 } 91 92 int 93 main(int argc, char *argv[], char *envp[]) 94 { 95 FILE *config; 96 char *line, *cp, *from, *to, *ap; 97 const char *progname; 98 size_t len, lineno = 0; 99 struct arglist al; 100 101 /* change __progname to mailwrapper so we get sensible error messages */ 102 progname = __progname; 103 __progname = "mailwrapper"; 104 105 initarg(&al); 106 for (len = 0; len < argc; len++) 107 addarg(&al, argv[len], 0); 108 109 if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL) { 110 addarg(&al, NULL, 0); 111 openlog(__progname, LOG_PID, LOG_MAIL); 112 syslog(LOG_INFO, "cannot open %s, using %s as default MTA", 113 _PATH_MAILERCONF, _PATH_DEFAULTMTA); 114 closelog(); 115 execve(_PATH_DEFAULTMTA, al.argv, envp); 116 err(1, "cannot exec %s", _PATH_DEFAULTMTA); 117 /*NOTREACHED*/ 118 } 119 120 for (;;) { 121 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 122 if (feof(config)) 123 errx(1, "no mapping in %s", _PATH_MAILERCONF); 124 err(1, "fparseln"); 125 } 126 127 #define WS " \t\n" 128 cp = line; 129 130 cp += strspn(cp, WS); 131 if (cp[0] == '\0') { 132 /* empty line */ 133 free(line); 134 continue; 135 } 136 137 if ((from = strsep(&cp, WS)) == NULL) 138 goto parse_error; 139 140 cp += strspn(cp, WS); 141 142 if ((to = strsep(&cp, WS)) == NULL) 143 goto parse_error; 144 145 if (strcmp(from, progname) == 0) { 146 for (ap = strsep(&cp, WS); ap != NULL; 147 ap = strsep(&cp, WS)) 148 if (*ap) 149 addarg(&al, ap, 0); 150 break; 151 } 152 153 free(line); 154 } 155 156 (void)fclose(config); 157 158 addarg(&al, NULL, 0); 159 160 execve(to, al.argv, envp); 161 err(1, "cannot exec %s", to); 162 /*NOTREACHED*/ 163 parse_error: 164 errx(1, "parse error in %s at line %lu", 165 _PATH_MAILERCONF, (u_long)lineno); 166 /*NOTREACHED*/ 167 } 168