2abe377059
writes to anything under /dev. revoke setuid/gid privs earlier. From: xs@kittenz.org
118 lines
3.6 KiB
C
118 lines
3.6 KiB
C
/* $NetBSD: utmp_update.c,v 1.4 2002/08/16 20:21:48 itojun Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2002 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Christos Zoulas.
|
|
*
|
|
* 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 acknowledgement:
|
|
* This product includes software developed by the NetBSD
|
|
* Foundation, Inc. and its contributors.
|
|
* 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``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 FOUNDATION OR CONTRIBUTORS
|
|
* 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 <sys/stat.h>
|
|
|
|
#include <stdio.h>
|
|
#include <vis.h>
|
|
#include <err.h>
|
|
#include <fcntl.h>
|
|
#include <pwd.h>
|
|
#include <utmpx.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
int main(int, char *[]);
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
struct utmpx *utx;
|
|
size_t len;
|
|
struct passwd *pwd;
|
|
struct stat st;
|
|
int fd;
|
|
uid_t euid;
|
|
|
|
euid = geteuid();
|
|
if (seteuid(getuid()) == -1)
|
|
err(1, "seteuid");
|
|
|
|
if (argc != 2) {
|
|
(void)fprintf(stderr, "Usage: %s <vis-utmpx-entry>\n",
|
|
getprogname());
|
|
exit(1);
|
|
}
|
|
|
|
len = strlen(argv[1]);
|
|
|
|
if (len > sizeof(*utx) * 4 + 1 || len < sizeof(*utx))
|
|
errx(1, "Bad argument");
|
|
|
|
if ((utx = malloc(len)) == NULL)
|
|
err(1, NULL);
|
|
|
|
if (strunvis((char *)utx, argv[1]) != sizeof(*utx))
|
|
errx(1, "Decoding error");
|
|
|
|
switch (utx->ut_type) {
|
|
case USER_PROCESS:
|
|
case DEAD_PROCESS:
|
|
break;
|
|
default:
|
|
errx(1, "Invalid utmpx type %d", (int)utx->ut_type);
|
|
}
|
|
|
|
if ((pwd = getpwuid(getuid())) == NULL)
|
|
errx(1, "User %lu does not exist in password database",
|
|
(long)getuid());
|
|
|
|
if (strcmp(pwd->pw_name, utx->ut_name) != 0)
|
|
errx(1, "Current user `%s' does not match `%s' in utmpx entry",
|
|
pwd->pw_name, utx->ut_name);
|
|
|
|
fd = open(utx->ut_line, O_RDONLY, 0);
|
|
if (fd == -1)
|
|
err(1, "Cannot open `%s'", utx->ut_line);
|
|
if (fstat(fd, &st) == -1)
|
|
err(1, "Cannot stat `%s'", utx->ut_line);
|
|
if (st.st_uid != getuid())
|
|
errx(1, "%s: Is not owned by you", utx->ut_line);
|
|
if (!isatty(fd))
|
|
errx(1, "%s: Not a tty device", utx->ut_line);
|
|
close(fd);
|
|
if (access(utx->ut_line, W_OK|R_OK) == -1)
|
|
err(1, "%s", utx->ut_line);
|
|
|
|
(void)seteuid(euid);
|
|
pututxline(utx);
|
|
|
|
return 0;
|
|
}
|