File: [local] / src / usr.sbin / chroot / chroot.c (download)
Revision 1.14, Tue May 19 16:05:12 2015 UTC (9 years ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, OPENBSD_7_3_BASE, OPENBSD_7_3, OPENBSD_7_2_BASE, OPENBSD_7_2, OPENBSD_7_1_BASE, OPENBSD_7_1, OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6, OPENBSD_6_5_BASE, OPENBSD_6_5, OPENBSD_6_4_BASE, OPENBSD_6_4, OPENBSD_6_3_BASE, OPENBSD_6_3, OPENBSD_6_2_BASE, OPENBSD_6_2, OPENBSD_6_1_BASE, OPENBSD_6_1, OPENBSD_6_0_BASE, OPENBSD_6_0, OPENBSD_5_9_BASE, OPENBSD_5_9, OPENBSD_5_8_BASE, OPENBSD_5_8, HEAD Changes since 1.13: +16 -9 lines
When a user is specified via the -u flag, use setusercontext() to
setup (most of) the execution environment. We still have to defer
setting the actual uid until after we change root. OK deraadt@
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/* $OpenBSD: chroot.c,v 1.14 2015/05/19 16:05:12 millert Exp $ */
/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. 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. Neither the name of the University 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 REGENTS 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 REGENTS 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/types.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <limits.h>
#include <login_cap.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main(int, char **);
__dead void usage(void);
int
main(int argc, char **argv)
{
struct group *grp;
struct passwd *pwd;
login_cap_t *lc;
const char *shell;
char *user, *group, *grouplist;
gid_t gidlist[NGROUPS_MAX];
int ch, ngids;
int flags = LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETUSER);
lc = NULL;
ngids = 0;
pwd = NULL;
user = grouplist = NULL;
while ((ch = getopt(argc, argv, "g:u:")) != -1) {
switch(ch) {
case 'u':
user = optarg;
if (*user == '\0')
usage();
break;
case 'g':
grouplist = optarg;
if (*grouplist == '\0')
usage();
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc < 1)
usage();
if (user != NULL) {
if ((pwd = getpwnam(user)) == NULL)
errx(1, "no such user `%s'", user);
if ((lc = login_getclass(pwd->pw_class)) == NULL)
err(1, "unable to get login class for `%s'", user);
}
while ((group = strsep(&grouplist, ",")) != NULL) {
if (*group == '\0')
continue;
if (ngids == NGROUPS_MAX)
errx(1, "too many supplementary groups provided");
if ((grp = getgrnam(group)) == NULL)
errx(1, "no such group `%s'", group);
gidlist[ngids++] = grp->gr_gid;
}
if (ngids != 0) {
if (setgid(gidlist[0]) != 0)
err(1, "setgid");
if (setgroups(ngids, gidlist) != 0)
err(1, "setgroups");
flags &= ~LOGIN_SETGROUP;
}
if (lc != NULL) {
if (setusercontext(lc, pwd, pwd->pw_uid, flags) == -1)
err(1, "setusercontext");
}
if (chroot(argv[0]) != 0 || chdir("/") != 0)
err(1, "%s", argv[0]);
if (pwd != NULL) {
/* only set login name if we are/can be a session leader */
if (getsid(0) == getpid() || setsid() != -1)
setlogin(pwd->pw_name);
if (setuid(pwd->pw_uid) != 0)
err(1, "setuid");
}
if (argv[1]) {
execvp(argv[1], &argv[1]);
err(1, "%s", argv[1]);
}
if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
shell = _PATH_BSHELL;
execlp(shell, shell, "-i", (char *)NULL);
err(1, "%s", shell);
/* NOTREACHED */
}
__dead void
usage(void)
{
extern char *__progname;
(void)fprintf(stderr, "usage: %s [-g group,group,...] [-u user] "
"newroot [command]\n", __progname);
exit(1);
}