Home | History | Annotate | Line # | Download | only in mailwrapper 
      1 /*	$NetBSD: mailwrapper.c,v 1.11 2018/01/23 21:06:25 sevan 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 	const char **argv;
     45 };
     46 
     47 static void initarg(struct arglist *);
     48 static void addarg(struct arglist *, const char *, int);
     49 
     50 static void
     51 initarg(struct arglist *al)
     52 {
     53 	al->argc = 0;
     54 	al->maxc = 10;
     55 	if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
     56 		/*
     57 		 * This (using err("mailwrapper")) is intentional.
     58 		 * Mailwrapper plays ugly games with argv[0] and thus it
     59 		 * is often difficult for people to know that the error
     60 		 * isn't from "mailq" or "sendmail" but from mailwrapper
     61 		 * -- having mailwrapper add an indication that it was really
     62 		 * mailwrapper running was a requested feature.
     63 		 */
     64 		err(1, "mailwrapper");
     65 }
     66 
     67 static void
     68 addarg(struct arglist *al, const char *arg, int copy)
     69 {
     70 	if (al->argc == al->maxc) {
     71 	    al->maxc <<= 1;
     72 	    if ((al->argv = realloc(al->argv,
     73 		al->maxc * sizeof(char *))) == NULL)
     74 		    err(1, "mailwrapper");
     75 	}
     76 	if (copy) {
     77 		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
     78 			err(1, "mailwrapper:");
     79 	} else
     80 		al->argv[al->argc++] = arg;
     81 }
     82 
     83 int
     84 main(int argc, char *argv[], char *envp[])
     85 {
     86 	FILE *config;
     87 	char *line, *cp, *from, *to, *ap;
     88 	size_t len, lineno = 0;
     89 	int i;
     90 	struct arglist al;
     91 
     92 	initarg(&al);
     93 	addarg(&al, argv[0], 0);
     94 
     95 	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
     96 		err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
     97 
     98 	for (;;) {
     99 		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
    100 			if (feof(config))
    101 				errx(1, "mailwrapper: no mapping in %s",
    102 				    _PATH_MAILERCONF);
    103 			err(1, "mailwrapper");
    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, __UNCONST(al.argv), envp);
    142 	err(1, "mailwrapper: execing %s", to);
    143 	/*NOTREACHED*/
    144 parse_error:
    145 	errx(1, "mailwrapper: parse error in %s at line %lu",
    146 	    _PATH_MAILERCONF, (u_long)lineno);
    147 	/*NOTREACHED*/
    148 }
    149