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 * 4. 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 30 #if 0 31 #ifndef lint 32 static const char copyright[] = 33 "@(#) Copyright (c) 1988, 1993\n\ 34 The Regents of the University of California. All rights reserved.\n"; 35 #endif /* not lint */ 36 37 #ifndef lint 38 static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93"; 39 #endif /* not lint */ 40 #endif 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/types.h> 45 46 #include <ctype.h> 47 #include <err.h> 48 #include <grp.h> 49 #include <limits.h> 50 #include <paths.h> 51 #include <pwd.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 static void usage(void); 58 59 char *user; /* user to switch to before running program */ 60 char *group; /* group to switch to ... */ 61 char *grouplist; /* group list to switch to ... */ 62 63 int 64 main(argc, argv) 65 int argc; 66 char *argv[]; 67 { 68 struct group *gp; 69 struct passwd *pw; 70 char *endp, *p; 71 const char *shell; 72 gid_t gid, gidlist[NGROUPS_MAX]; 73 uid_t uid; 74 int ch, gids; 75 76 gid = 0; 77 uid = 0; 78 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) { 79 switch(ch) { 80 case 'u': 81 user = optarg; 82 if (*user == '\0') 83 usage(); 84 break; 85 case 'g': 86 group = optarg; 87 if (*group == '\0') 88 usage(); 89 break; 90 case 'G': 91 grouplist = optarg; 92 if (*grouplist == '\0') 93 usage(); 94 break; 95 case '?': 96 default: 97 usage(); 98 } 99 } 100 argc -= optind; 101 argv += optind; 102 103 if (argc < 1) 104 usage(); 105 106 if (group != NULL) { 107 if (isdigit((unsigned char)*group)) { 108 gid = (gid_t)strtoul(group, &endp, 0); 109 if (*endp != '\0') 110 goto getgroup; 111 } else { 112 getgroup: 113 if ((gp = getgrnam(group)) != NULL) 114 gid = gp->gr_gid; 115 else 116 errx(1, "no such group `%s'", group); 117 } 118 } 119 120 for (gids = 0; 121 (p = strsep(&grouplist, ",")) != NULL && gids < NGROUPS_MAX; ) { 122 if (*p == '\0') 123 continue; 124 125 if (isdigit((unsigned char)*p)) { 126 gidlist[gids] = (gid_t)strtoul(p, &endp, 0); 127 if (*endp != '\0') 128 goto getglist; 129 } else { 130 getglist: 131 if ((gp = getgrnam(p)) != NULL) 132 gidlist[gids] = gp->gr_gid; 133 else 134 errx(1, "no such group `%s'", p); 135 } 136 gids++; 137 } 138 if (p != NULL && gids == NGROUPS_MAX) 139 errx(1, "too many supplementary groups provided"); 140 141 if (user != NULL) { 142 if (isdigit((unsigned char)*user)) { 143 uid = (uid_t)strtoul(user, &endp, 0); 144 if (*endp != '\0') 145 goto getuser; 146 } else { 147 getuser: 148 if ((pw = getpwnam(user)) != NULL) 149 uid = pw->pw_uid; 150 else 151 errx(1, "no such user `%s'", user); 152 } 153 } 154 155 if (chdir(argv[0]) == -1 || chroot(".") == -1) 156 err(1, "%s", argv[0]); 157 158 if (gids && setgroups(gids, gidlist) == -1) 159 err(1, "setgroups"); 160 if (group && setgid(gid) == -1) 161 err(1, "setgid"); 162 if (user && setuid(uid) == -1) 163 err(1, "setuid"); 164 165 if (argv[1]) { 166 execvp(argv[1], &argv[1]); 167 err(1, "%s", argv[1]); 168 } 169 170 if (!(shell = getenv("SHELL"))) 171 shell = _PATH_BSHELL; 172 execlp(shell, shell, "-i", (char *)NULL); 173 err(1, "%s", shell); 174 /* NOTREACHED */ 175 } 176 177 static void 178 usage() 179 { 180 (void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 181 "[-u user] newroot [command]\n"); 182 exit(1); 183 } 184