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mailwrapper.c revision 1.2 
      1 /*	$NetBSD: mailwrapper.c,v 1.2 1999/02/20 22:10:07 thorpej 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 #include <util.h>
     40 
     41 #define _PATH_MAILERCONF	"/etc/mailer.conf"
     42 
     43 int main __P((int, char *[], char *[]));
     44 
     45 extern const char *__progname;	/* from crt0.o */
     46 
     47 int
     48 main(argc, argv, envp)
     49 	int argc;
     50 	char *argv[];
     51 	char *envp[];
     52 {
     53 	FILE *config;
     54 	char *line, *cp, *from, *to;
     55 	size_t len, lineno = 0;
     56 
     57 	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
     58 		err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
     59 
     60 	for (;;) {
     61 		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
     62 			if (feof(config))
     63 				errx(1, "mailwrapper: no mapping in %s",
     64 				    _PATH_MAILERCONF);
     65 			err(1, "mailwrapper");
     66 		}
     67 
     68 #define	WHITESPACE	" \t"
     69 #define	PARSE_ERROR \
     70 		errx(1, "mailwrapper: parse error in %s at line %lu", \
     71 		    _PATH_MAILERCONF, (u_long)lineno)
     72 
     73 		cp = line;
     74 
     75 		cp += strspn(cp, WHITESPACE);
     76 		if (cp[0] == '\0') {
     77 			/* empty line */
     78 			free(line);
     79 			continue;
     80 		}
     81 
     82 		if ((from = strsep(&cp, WHITESPACE)) == NULL)
     83 			PARSE_ERROR;
     84 
     85 		cp += strspn(cp, WHITESPACE);
     86 
     87 		if ((to = strsep(&cp, WHITESPACE)) == NULL)
     88 			PARSE_ERROR;
     89 
     90 		if (cp != NULL) {
     91 			cp += strspn(cp, WHITESPACE);
     92 			if (cp[0] != '\0')
     93 				PARSE_ERROR;
     94 		}
     95 
     96 		if (strcmp(from, __progname) == 0)
     97 			break;
     98 
     99 		free(line);
    100 	}
    101 
    102 	fclose(config);
    103 
    104 	execve(to, argv, envp);
    105 
    106 	err(1, "mailwrapper: execing %s", to);
    107 }
    108