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/* $OpenBSD: chroot.c,v 1.14 2015/05/19 16:05:12 millert 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/types.h> |
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#include <ctype.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 <limits.h> |
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#include <login_cap.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 <string.h> |
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#include <unistd.h> |
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int main(int, char **); |
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__dead void usage(void); |
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int |
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main(int argc, char **argv) |
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{ |
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struct group *grp; |
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struct passwd *pwd; |
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login_cap_t *lc; |
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const char *shell; |
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char *user, *group, *grouplist; |
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gid_t gidlist[NGROUPS_MAX]; |
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int ch, ngids; |
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int flags = LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETUSER); |
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lc = NULL; |
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ngids = 0; |
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pwd = NULL; |
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user = grouplist = NULL; |
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while ((ch = getopt(argc, argv, "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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grouplist = optarg; |
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if (*grouplist == '\0') |
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usage(); |
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break; |
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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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if ((pwd = getpwnam(user)) == NULL) |
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errx(1, "no such user `%s'", user); |
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if ((lc = login_getclass(pwd->pw_class)) == NULL) |
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err(1, "unable to get login class for `%s'", user); |
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} |
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while ((group = strsep(&grouplist, ",")) != NULL) { |
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if (*group == '\0') |
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continue; |
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if (ngids == NGROUPS_MAX) |
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errx(1, "too many supplementary groups provided"); |
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if ((grp = getgrnam(group)) == NULL) |
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errx(1, "no such group `%s'", group); |
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gidlist[ngids++] = grp->gr_gid; |
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} |
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if (ngids != 0) { |
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if (setgid(gidlist[0]) != 0) |
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err(1, "setgid"); |
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if (setgroups(ngids, gidlist) != 0) |
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err(1, "setgroups"); |
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flags &= ~LOGIN_SETGROUP; |
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} |
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if (lc != NULL) { |
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if (setusercontext(lc, pwd, pwd->pw_uid, flags) == -1) |
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err(1, "setusercontext"); |
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} |
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if (chroot(argv[0]) != 0 || chdir("/") != 0) |
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err(1, "%s", argv[0]); |
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if (pwd != NULL) { |
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/* only set login name if we are/can be a session leader */ |
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if (getsid(0) == getpid() || setsid() != -1) |
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setlogin(pwd->pw_name); |
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if (setuid(pwd->pw_uid) != 0) |
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err(1, "setuid"); |
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} |
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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 || *shell == '\0') |
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shell = _PATH_BSHELL; |
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execlp(shell, shell, "-i", (char *)NULL); |
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err(1, "%s", shell); |
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/* NOTREACHED */ |
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} |
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__dead void |
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usage(void) |
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{ |
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extern char *__progname; |
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(void)fprintf(stderr, "usage: %s [-g group,group,...] [-u user] " |
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"newroot [command]\n", __progname); |
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exit(1); |
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} |