1 /* $OpenBSD: mailwrapper.c,v 1.23 2017/06/14 16:32:11 anton 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/sbin/smtpctl" 45 46 struct arglist { 47 size_t argc, maxc; 48 char **argv; 49 }; 50 51 static void initarg(struct arglist *); 52 static void addarg(struct arglist *, const char *); 53 54 extern const char *__progname; /* from crt0.o */ 55 56 static void 57 initarg(struct arglist *al) 58 { 59 al->argc = 0; 60 al->maxc = 10; 61 if ((al->argv = calloc(al->maxc, sizeof(char *))) == NULL) 62 err(1, "malloc"); 63 } 64 65 static void 66 addarg(struct arglist *al, const char *arg) 67 { 68 if (al->argc == al->maxc) { 69 al->maxc <<= 1; 70 al->argv = reallocarray(al->argv, al->maxc, sizeof(char *)); 71 if (al->argv == NULL) 72 err(1, "realloc"); 73 } 74 75 al->argv[al->argc++] = (char *)arg; 76 } 77 78 int 79 main(int argc, char *argv[]) 80 { 81 FILE *config; 82 char *line, *cp, *from, *to, *ap; 83 const char *progname; 84 size_t len, lineno = 0; 85 struct arglist al; 86 87 if (pledge("stdio rpath exec", NULL) == -1) 88 err(1, "pledge"); 89 90 /* change __progname to mailwrapper so we get sensible error messages */ 91 progname = __progname; 92 __progname = "mailwrapper"; 93 94 initarg(&al); 95 for (len = 0; len < argc; len++) 96 addarg(&al, argv[len]); 97 98 config = fopen(_PATH_MAILERCONF, "r"); 99 100 if (pledge("stdio exec", NULL) == -1) 101 err(1, "pledge"); 102 103 if (config == NULL) { 104 addarg(&al, NULL); 105 openlog(__progname, LOG_PID, LOG_MAIL); 106 syslog(LOG_INFO, "cannot open %s, using %s as default MTA", 107 _PATH_MAILERCONF, _PATH_DEFAULTMTA); 108 closelog(); 109 execv(_PATH_DEFAULTMTA, al.argv); 110 err(1, "cannot exec %s", _PATH_DEFAULTMTA); 111 /*NOTREACHED*/ 112 } 113 114 for (;;) { 115 if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) { 116 if (feof(config)) 117 errx(1, "no mapping in %s", _PATH_MAILERCONF); 118 err(1, "fparseln"); 119 } 120 121 #define WS " \t\n" 122 cp = line; 123 124 cp += strspn(cp, WS); 125 if (cp[0] == '\0') { 126 /* empty line */ 127 free(line); 128 continue; 129 } 130 131 if ((from = strsep(&cp, WS)) == NULL || cp == NULL) 132 goto parse_error; 133 134 cp += strspn(cp, WS); 135 136 if ((to = strsep(&cp, WS)) == NULL) 137 goto parse_error; 138 139 if (strcmp(from, progname) == 0) { 140 for (ap = strsep(&cp, WS); ap != NULL; 141 ap = strsep(&cp, WS)) 142 if (*ap) 143 addarg(&al, ap); 144 break; 145 } 146 147 free(line); 148 } 149 150 (void)fclose(config); 151 152 addarg(&al, NULL); 153 154 execv(to, al.argv); 155 err(1, "cannot exec %s", to); 156 /*NOTREACHED*/ 157 parse_error: 158 errx(1, "parse error in %s at line %lu", 159 _PATH_MAILERCONF, (u_long)lineno); 160 /*NOTREACHED*/ 161 } 162