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mailwrapper.c revision 1.9 
      1 /*	$NetBSD: mailwrapper.c,v 1.9 2003/03/09 08:10:43 mjl Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998
      5  * 	Perry E. Metzger.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgment:
     17  *	This product includes software developed for the NetBSD Project
     18  *	by Perry E. Metzger.
     19  * 4. The name of the author may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <err.h>
     35 #include <stdio.h>
     36 #include <string.h>
     37 #include <stdlib.h>
     38 #include <unistd.h>
     39 
     40 #define _PATH_MAILERCONF	"/etc/mailer.conf"
     41 
     42 struct arglist {
     43 	size_t argc, maxc;
     44 	char **argv;
     45 };
     46 
     47 int main __P((int, char *[], char *[]));
     48 
     49 static void initarg __P((struct arglist *));
     50 static void addarg __P((struct arglist *, const char *, int));
     51 
     52 static void
     53 initarg(al)
     54 	struct arglist *al;
     55 {
     56 	al->argc = 0;
     57 	al->maxc = 10;
     58 	if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
     59 		/*
     60 		 * This (using err("mailwrapper")) is intentional.
     61 		 * Mailwrapper plays ugly games with argv[0] and thus it
     62 		 * is often difficult for people to know that the error
     63 		 * isn't from "mailq" or "sendmail" but from mailwrapper
     64 		 * -- having mailwrapper add an indication that it was really
     65 		 * mailwrapper running was a requested feature.
     66 		 */
     67 		err(1, "mailwrapper");
     68 }
     69 
     70 static void
     71 addarg(al, arg, copy)
     72 	struct arglist *al;
     73 	const char *arg;
     74 	int copy;
     75 {
     76 	if (al->argc == al->maxc) {
     77 	    al->maxc <<= 1;
     78 	    if ((al->argv = realloc(al->argv,
     79 		al->maxc * sizeof(char *))) == NULL)
     80 		    err(1, "mailwrapper");
     81 	}
     82 	if (copy) {
     83 		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
     84 			err(1, "mailwrapper:");
     85 	} else
     86 		al->argv[al->argc++] = (char *)arg;
     87 }
     88 
     89 int
     90 main(argc, argv, envp)
     91 	int argc;
     92 	char *argv[];
     93 	char *envp[];
     94 {
     95 	FILE *config;
     96 	char *line, *cp, *from, *to, *ap;
     97 	size_t len, lineno = 0;
     98 	int i;
     99 	struct arglist al;
    100 
    101 	initarg(&al);
    102 	addarg(&al, argv[0], 0);
    103 
    104 	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
    105 		err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
    106 
    107 	for (;;) {
    108 		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
    109 			if (feof(config))
    110 				errx(1, "mailwrapper: no mapping in %s",
    111 				    _PATH_MAILERCONF);
    112 			err(1, "mailwrapper");
    113 		}
    114 
    115 #define	WS	" \t\n"
    116 		cp = line;
    117 
    118 		cp += strspn(cp, WS);
    119 		if (cp[0] == '\0') {
    120 			/* empty line */
    121 			free(line);
    122 			continue;
    123 		}
    124 
    125 		if ((from = strsep(&cp, WS)) == NULL)
    126 			goto parse_error;
    127 
    128 		cp += strspn(cp, WS);
    129 
    130 		if ((to = strsep(&cp, WS)) == NULL)
    131 			goto parse_error;
    132 
    133 		if (strcmp(from, getprogname()) == 0) {
    134 			for (ap = strsep(&cp, WS); ap != NULL;
    135 			    ap = strsep(&cp, WS))
    136 			    if (*ap)
    137 				    addarg(&al, ap, 0);
    138 			break;
    139 		}
    140 
    141 		free(line);
    142 	}
    143 
    144 	(void)fclose(config);
    145 
    146 	for (i = 1; i < argc; i++)
    147 		addarg(&al, argv[i], 0);
    148 
    149 	addarg(&al, NULL, 0);
    150 	execve(to, al.argv, envp);
    151 	err(1, "mailwrapper: execing %s", to);
    152 	/*NOTREACHED*/
    153 parse_error:
    154 	errx(1, "mailwrapper: parse error in %s at line %lu",
    155 	    _PATH_MAILERCONF, (u_long)lineno);
    156 	/*NOTREACHED*/
    157 }
    158