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 1.5 2003/11/15 23:33:35 eirikn 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 char *user; /* user to switch to before running program */ 55 char *group; /* group to switch to ... */ 56 char *grouplist; /* group list to switch to ... */ 57 58 int 59 main(int argc, char **argv) 60 { 61 struct group *gp; 62 struct passwd *pw; 63 char *endp, *p; 64 const char *shell; 65 gid_t gid, gidlist[NGROUPS_MAX]; 66 uid_t uid; 67 int ch, gids; 68 69 gid = 0; 70 uid = 0; 71 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) { 72 switch(ch) { 73 case 'u': 74 user = optarg; 75 if (*user == '\0') 76 usage(); 77 break; 78 case 'g': 79 group = optarg; 80 if (*group == '\0') 81 usage(); 82 break; 83 case 'G': 84 grouplist = optarg; 85 if (*grouplist == '\0') 86 usage(); 87 break; 88 case '?': 89 default: 90 usage(); 91 } 92 } 93 argc -= optind; 94 argv += optind; 95 96 if (argc < 1) 97 usage(); 98 99 if (group != NULL) { 100 if (isdigit((unsigned char)*group)) { 101 gid = (gid_t)strtoul(group, &endp, 0); 102 if (*endp != '\0') 103 goto getgroup; 104 } else { 105 getgroup: 106 if ((gp = getgrnam(group)) != NULL) 107 gid = gp->gr_gid; 108 else 109 errx(1, "no such group `%s'", group); 110 } 111 } 112 113 for (gids = 0; 114 (p = strsep(&grouplist, ",")) != NULL && gids < NGROUPS_MAX; ) { 115 if (*p == '\0') 116 continue; 117 118 if (isdigit((unsigned char)*p)) { 119 gidlist[gids] = (gid_t)strtoul(p, &endp, 0); 120 if (*endp != '\0') 121 goto getglist; 122 } else { 123 getglist: 124 if ((gp = getgrnam(p)) != NULL) 125 gidlist[gids] = gp->gr_gid; 126 else 127 errx(1, "no such group `%s'", p); 128 } 129 gids++; 130 } 131 if (p != NULL && gids == NGROUPS_MAX) 132 errx(1, "too many supplementary groups provided"); 133 134 if (user != NULL) { 135 if (isdigit((unsigned char)*user)) { 136 uid = (uid_t)strtoul(user, &endp, 0); 137 if (*endp != '\0') 138 goto getuser; 139 } else { 140 getuser: 141 if ((pw = getpwnam(user)) != NULL) 142 uid = pw->pw_uid; 143 else 144 errx(1, "no such user `%s'", user); 145 } 146 } 147 148 if (chdir(argv[0]) == -1 || chroot(".") == -1) 149 err(1, "%s", argv[0]); 150 151 if (gids && setgroups(gids, gidlist) == -1) 152 err(1, "setgroups"); 153 if (group && setgid(gid) == -1) 154 err(1, "setgid"); 155 if (user && setuid(uid) == -1) 156 err(1, "setuid"); 157 158 if (argv[1]) { 159 execvp(argv[1], &argv[1]); 160 err(1, "%s", argv[1]); 161 } 162 163 if (!(shell = getenv("SHELL"))) 164 shell = _PATH_BSHELL; 165 execlp(shell, shell, "-i", (char *)NULL); 166 err(1, "%s", shell); 167 /* NOTREACHED */ 168 } 169 170 static void 171 usage(void) 172 { 173 (void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 174 "[-u user] newroot [command]\n"); 175 exit(1); 176 } 177 178