NetBSD/usr.sbin/mailwrapper/mailwrapper.c

149 lines
4.1 KiB
C

/* $NetBSD: mailwrapper.c,v 1.11 2018/01/23 21:06:25 sevan Exp $ */
/*
* Copyright (c) 1998
* Perry E. Metzger. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* This product includes software developed for the NetBSD Project
* by Perry E. Metzger.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#define _PATH_MAILERCONF "/etc/mailer.conf"
struct arglist {
size_t argc, maxc;
const char **argv;
};
static void initarg(struct arglist *);
static void addarg(struct arglist *, const char *, int);
static void
initarg(struct arglist *al)
{
al->argc = 0;
al->maxc = 10;
if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
/*
* This (using err("mailwrapper")) is intentional.
* Mailwrapper plays ugly games with argv[0] and thus it
* is often difficult for people to know that the error
* isn't from "mailq" or "sendmail" but from mailwrapper
* -- having mailwrapper add an indication that it was really
* mailwrapper running was a requested feature.
*/
err(1, "mailwrapper");
}
static void
addarg(struct arglist *al, const char *arg, int copy)
{
if (al->argc == al->maxc) {
al->maxc <<= 1;
if ((al->argv = realloc(al->argv,
al->maxc * sizeof(char *))) == NULL)
err(1, "mailwrapper");
}
if (copy) {
if ((al->argv[al->argc++] = strdup(arg)) == NULL)
err(1, "mailwrapper:");
} else
al->argv[al->argc++] = arg;
}
int
main(int argc, char *argv[], char *envp[])
{
FILE *config;
char *line, *cp, *from, *to, *ap;
size_t len, lineno = 0;
int i;
struct arglist al;
initarg(&al);
addarg(&al, argv[0], 0);
if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
for (;;) {
if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
if (feof(config))
errx(1, "mailwrapper: no mapping in %s",
_PATH_MAILERCONF);
err(1, "mailwrapper");
}
#define WS " \t\n"
cp = line;
cp += strspn(cp, WS);
if (cp[0] == '\0') {
/* empty line */
free(line);
continue;
}
if ((from = strsep(&cp, WS)) == NULL)
goto parse_error;
cp += strspn(cp, WS);
if ((to = strsep(&cp, WS)) == NULL)
goto parse_error;
if (strcmp(from, getprogname()) == 0) {
for (ap = strsep(&cp, WS); ap != NULL;
ap = strsep(&cp, WS))
if (*ap)
addarg(&al, ap, 0);
break;
}
free(line);
}
(void)fclose(config);
for (i = 1; i < argc; i++)
addarg(&al, argv[i], 0);
addarg(&al, NULL, 0);
execve(to, __UNCONST(al.argv), envp);
err(1, "mailwrapper: execing %s", to);
/*NOTREACHED*/
parse_error:
errx(1, "mailwrapper: parse error in %s at line %lu",
_PATH_MAILERCONF, (u_long)lineno);
/*NOTREACHED*/
}