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mailwrapper.c revision 1.8 
      1 /*	$NetBSD: mailwrapper.c,v 1.8 2003/03/08 22:57:51 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 		err(1, "malloc");
     60 }
     61 
     62 static void
     63 addarg(al, arg, copy)
     64 	struct arglist *al;
     65 	const char *arg;
     66 	int copy;
     67 {
     68 	if (al->argc == al->maxc) {
     69 	    al->maxc <<= 1;
     70 	    if ((al->argv = realloc(al->argv,
     71 		al->maxc * sizeof(char *))) == NULL)
     72 		    err(1, "realloc");
     73 	}
     74 	if (copy) {
     75 		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
     76 			err(1, "strdup");
     77 	} else
     78 		al->argv[al->argc++] = (char *)arg;
     79 }
     80 
     81 int
     82 main(argc, argv, envp)
     83 	int argc;
     84 	char *argv[];
     85 	char *envp[];
     86 {
     87 	FILE *config;
     88 	char *line, *cp, *from, *to, *ap;
     89 	size_t len, lineno = 0;
     90 	int i;
     91 	struct arglist al;
     92 
     93 	initarg(&al);
     94 	addarg(&al, argv[0], 0);
     95 
     96 	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
     97 		err(1, "can't open %s", _PATH_MAILERCONF);
     98 
     99 	for (;;) {
    100 		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
    101 			if (feof(config))
    102 				errx(1, "no mapping in %s", _PATH_MAILERCONF);
    103 			err(1, "fparseln");
    104 		}
    105 
    106 #define	WS	" \t\n"
    107 		cp = line;
    108 
    109 		cp += strspn(cp, WS);
    110 		if (cp[0] == '\0') {
    111 			/* empty line */
    112 			free(line);
    113 			continue;
    114 		}
    115 
    116 		if ((from = strsep(&cp, WS)) == NULL)
    117 			goto parse_error;
    118 
    119 		cp += strspn(cp, WS);
    120 
    121 		if ((to = strsep(&cp, WS)) == NULL)
    122 			goto parse_error;
    123 
    124 		if (strcmp(from, getprogname()) == 0) {
    125 			for (ap = strsep(&cp, WS); ap != NULL;
    126 			    ap = strsep(&cp, WS))
    127 			    if (*ap)
    128 				    addarg(&al, ap, 0);
    129 			break;
    130 		}
    131 
    132 		free(line);
    133 	}
    134 
    135 	(void)fclose(config);
    136 
    137 	for (i = 1; i < argc; i++)
    138 		addarg(&al, argv[i], 0);
    139 
    140 	addarg(&al, NULL, 0);
    141 	execve(to, al.argv, envp);
    142 	err(1, "execing %s", to);
    143 	/*NOTREACHED*/
    144 parse_error:
    145 	errx(1, "parse error in %s at line %lu",
    146 	    _PATH_MAILERCONF, (u_long)lineno);
    147 	/*NOTREACHED*/
    148 }
    149