#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1993\n\
The Regents of the University of California. All rights reserved.\n");
#endif
#ifndef lint
#if 0
static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93";
#else
__RCSID("$NetBSD: chroot.c,v 1.7 1998/10/06 03:47:51 mrg Exp $");
#endif
#endif
#include <sys/param.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main __P((int, char **));
void usage __P((void)) __attribute__((__noreturn__));
char *user;
char *group;
char *grouplist;
int
main(argc, argv)
int argc;
char *argv[];
{
struct group *gp;
struct passwd *pw;
char *shell, *endp, *comma;
gid_t gid = 0, gidlist[NGROUPS_MAX];
uid_t uid = 0;
int ch, gids;
while ((ch = getopt(argc, argv, "G:g:u:")) != -1)
switch(ch) {
case 'u':
user = optarg;
break;
case 'g':
group = optarg;
break;
case 'G':
grouplist = optarg;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 1)
usage();
if (group) {
if (isdigit(*group)) {
gid = (gid_t)strtol(group, &endp, 0);
if (endp == group)
goto getgroup;
} else {
getgroup:
if ((gp = getgrnam(group)))
gid = gp->gr_gid;
else
errx(1, "no such group %s", group);
}
}
for (gids = 0; grouplist; ) {
comma = strchr(grouplist, ',');
if (comma)
*comma++ = '\0';
if (isdigit(*grouplist)) {
gidlist[gids] = (gid_t)strtol(grouplist, &endp, 0);
if (endp == grouplist)
goto getglist;
} else {
getglist:
if ((gp = getgrnam(grouplist)))
gidlist[gids] = gp->gr_gid;
else
errx(1, "no such group %s", group);
}
gids++;
grouplist = comma;
}
if (user) {
if (isdigit(*user)) {
uid = (uid_t)strtol(user, &endp, 0);
if (endp == user)
goto getuser;
} else {
getuser:
if ((pw = getpwnam(user)))
uid = pw->pw_uid;
else
errx(1, "no such user %s", user);
}
}
if (chdir(argv[0]) || chroot("."))
err(1, "%s", argv[0]);
if (gids && setgroups(gids, gidlist) < 0)
err(1, "setgroups");
if (group && setgid(gid) < 0)
err(1, "setgid");
if (user && setuid(uid) < 0)
err(1, "setuid");
if (argv[1]) {
execvp(argv[1], &argv[1]);
err(1, "%s", argv[1]);
}
if (!(shell = getenv("SHELL")))
shell = _PATH_BSHELL;
execlp(shell, shell, "-i", NULL);
err(1, "%s", shell);
}
void
usage()
{
(void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] "
"[-u user] newroot [command]\n");
exit(1);
}