ndhc/ncmlib/chroot.c
2010-11-12 18:46:45 -05:00

125 lines
3.2 KiB
C

/* chroot.c - chroots ndyndns jobs
* Time-stamp: <2010-11-03 05:23:56 njk>
*
* (c) 2005-2010 Nicholas J. Kain <njkain at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include "defines.h"
#include "log.h"
#include "strl.h"
static char chrootd[MAX_PATH_LENGTH] = "\0";
static char chroot_modified;
static char chroot_enable = 1;
void disable_chroot(void)
{
chroot_enable = 0;
}
int chroot_enabled(void)
{
return chroot_enable;
}
void update_chroot(const char *path)
{
strlcpy(chrootd, path, sizeof chrootd);
chroot_modified = 1;
}
int chroot_exists(void)
{
return chroot_modified;
}
char *get_chroot(void)
{
return chrootd;
}
void wipe_chroot(void)
{
memset(chrootd, '\0', sizeof chrootd);
}
void imprison(const char *path)
{
int ret;
if (path == NULL)
return;
ret = chdir(path);
if (ret) {
log_line("Failed to chdir(%s). Not invoking job.", path);
exit(EXIT_FAILURE);
}
if (chroot_enable) {
ret = chroot(path);
if (ret) {
log_line("Failed to chroot(%s). Not invoking job.", path);
exit(EXIT_FAILURE);
}
}
}
void drop_root(uid_t uid, gid_t gid)
{
if (uid == 0 || gid == 0) {
log_line("FATAL - drop_root: attempt to drop root to root?\n");
exit(EXIT_FAILURE);
}
if (getgid() == 0) {
if (setregid(gid, gid) == -1) {
log_line("FATAL - drop_root: failed to drop real gid == root!\n");
exit(EXIT_FAILURE);
}
}
if (getuid() == 0) {
if (setreuid(uid, uid) == -1) {
log_line("FATAL - drop_root: failed to drop real uid == root!\n");
exit(EXIT_FAILURE);
}
}
/* be absolutely sure */
if (getgid() == 0 || getuid() == 0) {
log_line("FATAL - drop_root: tried to drop root, but still have root!\n");
exit(EXIT_FAILURE);
}
}