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