1 /* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#) Copyright (c) 1988, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)chroot.c 8.1 (Berkeley) 6/9/93 35 * $FreeBSD: src/usr.sbin/chroot/chroot.c,v 1.4.2.1 2002/03/15 22:54:59 mikeh Exp $ 36 * $DragonFly: src/usr.sbin/chroot/chroot.c,v 1.9 2004/12/22 08:59:33 dillon Exp $ 37 */ 38 39 #include <sys/types.h> 40 41 #include <ctype.h> 42 #include <err.h> 43 #include <grp.h> 44 #include <limits.h> 45 #include <paths.h> 46 #include <pwd.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 static void usage(void); 53 54 int 55 main(int argc, char **argv) 56 { 57 struct group *gp; 58 struct passwd *pw; 59 char *endp, *p; 60 const char *shell; 61 const char *user; /* user to switch to before running program */ 62 const char *group; /* group to switch to ... */ 63 char *grouplist; /* group list to switch to ... */ 64 gid_t gid, gidlist[NGROUPS_MAX]; 65 uid_t uid; 66 int ch, gids; 67 68 user = NULL; 69 group = NULL; 70 grouplist = NULL; 71 72 gid = 0; 73 uid = 0; 74 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) { 75 switch(ch) { 76 case 'u': 77 user = optarg; 78 if (*user == '\0') 79 usage(); 80 break; 81 case 'g': 82 group = optarg; 83 if (*group == '\0') 84 usage(); 85 break; 86 case 'G': 87 grouplist = optarg; 88 if (*grouplist == '\0') 89 usage(); 90 break; 91 default: 92 usage(); 93 } 94 } 95 argc -= optind; 96 argv += optind; 97 98 if (argc < 1) 99 usage(); 100 101 if (group != NULL) { 102 if (isdigit(*group)) { 103 gid = (gid_t)strtoul(group, &endp, 0); 104 if (*endp != '\0') 105 goto getgroup; 106 } else { 107 getgroup: 108 if ((gp = getgrnam(group)) != NULL) 109 gid = gp->gr_gid; 110 else 111 errx(1, "no such group `%s'", group); 112 } 113 } 114 115 for (gids = 0; 116 (p = strsep(&grouplist, ",")) != NULL && gids < NGROUPS_MAX; ) { 117 if (*p == '\0') 118 continue; 119 120 if (isdigit(*p)) { 121 gidlist[gids] = (gid_t)strtoul(p, &endp, 0); 122 if (*endp != '\0') 123 goto getglist; 124 } else { 125 getglist: 126 if ((gp = getgrnam(p)) != NULL) 127 gidlist[gids] = gp->gr_gid; 128 else 129 errx(1, "no such group `%s'", p); 130 } 131 gids++; 132 } 133 if (p != NULL && gids == NGROUPS_MAX) 134 errx(1, "too many supplementary groups provided"); 135 136 if (user != NULL) { 137 if (isdigit(*user)) { 138 uid = (uid_t)strtoul(user, &endp, 0); 139 if (*endp != '\0') 140 goto getuser; 141 } else { 142 getuser: 143 if ((pw = getpwnam(user)) != NULL) 144 uid = pw->pw_uid; 145 else 146 errx(1, "no such user `%s'", user); 147 } 148 } 149 150 if (chdir(argv[0]) == -1 || chroot(".") == -1) 151 err(1, "%s", argv[0]); 152 153 if (gids && setgroups(gids, gidlist) == -1) 154 err(1, "setgroups"); 155 if (group && setgid(gid) == -1) 156 err(1, "setgid"); 157 if (user && setuid(uid) == -1) 158 err(1, "setuid"); 159 160 if (argv[1]) { 161 execvp(argv[1], &argv[1]); 162 err(1, "%s", argv[1]); 163 } 164 165 if (!(shell = getenv("SHELL"))) 166 shell = _PATH_BSHELL; 167 execlp(shell, shell, "-i", NULL); 168 err(1, "%s", shell); 169 /* NOTREACHED */ 170 } 171 172 static void 173 usage(void) 174 { 175 fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 176 "[-u user] newroot [command]\n"); 177 exit(1); 178 } 179 180