1 /* $NetBSD: chroot.c,v 1.8 2000/08/17 12:36:32 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93"; 45 #else 46 __RCSID("$NetBSD: chroot.c,v 1.8 2000/08/17 12:36:32 mrg Exp $"); 47 #endif 48 #endif /* not lint */ 49 50 #include <sys/param.h> 51 52 #include <ctype.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <grp.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 int main __P((int, char **)); 64 void usage __P((void)) __attribute__((__noreturn__)); 65 66 char *user; /* user to switch to before running program */ 67 char *group; /* group to switch to ... */ 68 char *grouplist; /* group list to switch to ... */ 69 70 int 71 main(argc, argv) 72 int argc; 73 char *argv[]; 74 { 75 struct group *gp; 76 struct passwd *pw; 77 char *shell, *endp, *comma; 78 gid_t gid = 0, gidlist[NGROUPS_MAX]; 79 uid_t uid = 0; 80 int ch, gids; 81 82 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) 83 switch(ch) { 84 case 'u': 85 user = optarg; 86 break; 87 case 'g': 88 group = optarg; 89 break; 90 case 'G': 91 grouplist = optarg; 92 break; 93 case '?': 94 default: 95 usage(); 96 } 97 argc -= optind; 98 argv += optind; 99 100 if (argc < 1) 101 usage(); 102 103 if (group) { 104 if (isdigit(*group)) { 105 gid = (gid_t)strtol(group, &endp, 0); 106 if (endp == group) 107 goto getgroup; 108 } else { 109 getgroup: 110 if ((gp = getgrnam(group))) 111 gid = gp->gr_gid; 112 else 113 errx(1, "no such group %s", group); 114 } 115 } 116 117 for (gids = 0; grouplist; ) { 118 comma = strchr(grouplist, ','); 119 120 if (comma) 121 *comma++ = '\0'; 122 123 if (isdigit(*grouplist)) { 124 gidlist[gids] = (gid_t)strtol(grouplist, &endp, 0); 125 if (endp == grouplist) 126 goto getglist; 127 } else { 128 getglist: 129 if ((gp = getgrnam(grouplist))) 130 gidlist[gids] = gp->gr_gid; 131 else 132 errx(1, "no such group %s", group); 133 } 134 gids++; 135 grouplist = comma; 136 } 137 138 if (user) { 139 if (isdigit(*user)) { 140 uid = (uid_t)strtol(user, &endp, 0); 141 if (endp == user) 142 goto getuser; 143 } else { 144 getuser: 145 if ((pw = getpwnam(user))) 146 uid = pw->pw_uid; 147 else 148 errx(1, "no such user %s", user); 149 } 150 } 151 152 if (chdir(argv[0]) || chroot(".")) 153 err(1, "%s", argv[0]); 154 155 if (gids && setgroups(gids, gidlist) < 0) 156 err(1, "setgroups"); 157 if (group && setgid(gid) < 0) 158 err(1, "setgid"); 159 if (user && setuid(uid) < 0) 160 err(1, "setuid"); 161 162 if (argv[1]) { 163 execvp(argv[1], &argv[1]); 164 err(1, "%s", argv[1]); 165 } 166 167 if (!(shell = getenv("SHELL"))) 168 shell = _PATH_BSHELL; 169 execlp(shell, shell, "-i", NULL); 170 err(1, "%s", shell); 171 /* NOTREACHED */ 172 } 173 174 void 175 usage() 176 { 177 (void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 178 "[-u user] newroot [command]\n"); 179 exit(1); 180 } 181