. make ramdisk buildable without ../etc having pwd.db . add cat to release bootstrap cmds . support running dynamically linked executables for release bootstrap cmds . import netbsd chroot to help
205 lines
4.6 KiB
C
205 lines
4.6 KiB
C
/* $NetBSD: chroot.c,v 1.19 2011/09/20 14:28:52 christos Exp $ */
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/*
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* Copyright (c) 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__COPYRIGHT("@(#) Copyright (c) 1988, 1993\
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The Regents of the University of California. All rights reserved.");
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#endif /* not lint */
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93";
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#else
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__RCSID("$NetBSD: chroot.c,v 1.19 2011/09/20 14:28:52 christos Exp $");
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#endif
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#endif /* not lint */
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#include <sys/param.h>
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#include <err.h>
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#include <errno.h>
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#include <grp.h>
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#include <paths.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <inttypes.h>
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#include <string.h>
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#include <unistd.h>
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static void usage(void) __dead;
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static int
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getnum(const char *str, uintmax_t *num)
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{
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char *ep;
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errno = 0;
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*num = strtoumax(str, &ep, 0);
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if (str[0] == '\0' || *ep != '\0') {
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errno = EINVAL;
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return -1;
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}
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if (errno == ERANGE && *num == UINTMAX_MAX)
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return -1;
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return 0;
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}
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static gid_t
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getgroup(const char *group)
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{
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uintmax_t num;
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struct group *gp;
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if ((gp = getgrnam(group)) != NULL)
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return gp->gr_gid;
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if (getnum(group, &num) == -1)
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errx(1, "no such group `%s'", group);
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return (gid_t)num;
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}
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static uid_t
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getuser(const char *user)
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{
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uintmax_t num;
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struct passwd *pw;
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if ((pw = getpwnam(user)) != NULL)
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return pw->pw_uid;
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if (getnum(user, &num) == -1)
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errx(1, "no such user `%s'", user);
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return (uid_t)num;
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}
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int
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main(int argc, char *argv[])
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{
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char *user; /* user to switch to before running program */
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char *group; /* group to switch to ... */
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char *grouplist; /* group list to switch to ... */
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char *p;
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const char *shell;
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gid_t gid, gidlist[NGROUPS_MAX];
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uid_t uid;
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int ch, gids;
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user = NULL;
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group = NULL;
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grouplist = NULL;
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gid = 0;
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uid = 0;
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gids = 0;
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while ((ch = getopt(argc, argv, "G:g:u:")) != -1) {
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switch(ch) {
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case 'u':
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user = optarg;
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if (*user == '\0')
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usage();
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break;
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case 'g':
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group = optarg;
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if (*group == '\0')
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usage();
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break;
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case 'G':
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grouplist = optarg;
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if (*grouplist == '\0')
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usage();
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break;
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case '?':
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default:
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usage();
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}
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}
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argc -= optind;
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argv += optind;
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if (argc < 1)
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usage();
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if (user != NULL)
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uid = getuser(user);
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if (group != NULL)
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gid = getgroup(group);
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if (grouplist != NULL) {
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while ((p = strsep(&grouplist, ",")) != NULL) {
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if (*p == '\0')
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continue;
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if (gids == NGROUPS_MAX)
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errx(1,
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"too many supplementary groups provided");
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gidlist[gids++] = getgroup(p);
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}
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}
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if (chdir(argv[0]) == -1 || chroot(".") == -1)
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err(1, "%s", argv[0]);
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if (gids && setgroups(gids, gidlist) == -1)
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err(1, "setgroups");
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if (group && setgid(gid) == -1)
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err(1, "setgid");
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if (user && setuid(uid) == -1)
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err(1, "setuid");
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if (argv[1]) {
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execvp(argv[1], &argv[1]);
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err(1, "%s", argv[1]);
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}
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if ((shell = getenv("SHELL")) == NULL)
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shell = _PATH_BSHELL;
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execlp(shell, shell, "-i", NULL);
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err(1, "%s", shell);
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/* NOTREACHED */
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}
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static void
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usage(void)
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{
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(void)fprintf(stderr, "Usage: %s [-G group,group,...] [-g group] "
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"[-u user] newroot [command]\n", getprogname());
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exit(1);
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}
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