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 34 #if 0 35 #ifndef lint 36 static const char copyright[] = 37 "@(#) Copyright (c) 1988, 1993\n\ 38 The Regents of the University of California. All rights reserved.\n"; 39 #endif /* not lint */ 40 41 #ifndef lint 42 static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93"; 43 #endif /* not lint */ 44 #endif 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <sys/types.h> 49 50 #include <ctype.h> 51 #include <err.h> 52 #include <grp.h> 53 #include <limits.h> 54 #include <paths.h> 55 #include <pwd.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 static void usage(void); 62 63 char *user; /* user to switch to before running program */ 64 char *group; /* group to switch to ... */ 65 char *grouplist; /* group list to switch to ... */ 66 67 int 68 main(argc, argv) 69 int argc; 70 char *argv[]; 71 { 72 struct group *gp; 73 struct passwd *pw; 74 char *endp, *p; 75 const char *shell; 76 gid_t gid, gidlist[NGROUPS_MAX]; 77 uid_t uid; 78 int ch, gids; 79 80 gid = 0; 81 uid = 0; 82 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) { 83 switch(ch) { 84 case 'u': 85 user = optarg; 86 if (*user == '\0') 87 usage(); 88 break; 89 case 'g': 90 group = optarg; 91 if (*group == '\0') 92 usage(); 93 break; 94 case 'G': 95 grouplist = optarg; 96 if (*grouplist == '\0') 97 usage(); 98 break; 99 case '?': 100 default: 101 usage(); 102 } 103 } 104 argc -= optind; 105 argv += optind; 106 107 if (argc < 1) 108 usage(); 109 110 if (group != NULL) { 111 if (isdigit((unsigned char)*group)) { 112 gid = (gid_t)strtoul(group, &endp, 0); 113 if (*endp != '\0') 114 goto getgroup; 115 } else { 116 getgroup: 117 if ((gp = getgrnam(group)) != NULL) 118 gid = gp->gr_gid; 119 else 120 errx(1, "no such group `%s'", group); 121 } 122 } 123 124 for (gids = 0; 125 (p = strsep(&grouplist, ",")) != NULL && gids < NGROUPS_MAX; ) { 126 if (*p == '\0') 127 continue; 128 129 if (isdigit((unsigned char)*p)) { 130 gidlist[gids] = (gid_t)strtoul(p, &endp, 0); 131 if (*endp != '\0') 132 goto getglist; 133 } else { 134 getglist: 135 if ((gp = getgrnam(p)) != NULL) 136 gidlist[gids] = gp->gr_gid; 137 else 138 errx(1, "no such group `%s'", p); 139 } 140 gids++; 141 } 142 if (p != NULL && gids == NGROUPS_MAX) 143 errx(1, "too many supplementary groups provided"); 144 145 if (user != NULL) { 146 if (isdigit((unsigned char)*user)) { 147 uid = (uid_t)strtoul(user, &endp, 0); 148 if (*endp != '\0') 149 goto getuser; 150 } else { 151 getuser: 152 if ((pw = getpwnam(user)) != NULL) 153 uid = pw->pw_uid; 154 else 155 errx(1, "no such user `%s'", user); 156 } 157 } 158 159 if (chdir(argv[0]) == -1 || chroot(".") == -1) 160 err(1, "%s", argv[0]); 161 162 if (gids && setgroups(gids, gidlist) == -1) 163 err(1, "setgroups"); 164 if (group && setgid(gid) == -1) 165 err(1, "setgid"); 166 if (user && setuid(uid) == -1) 167 err(1, "setuid"); 168 169 if (argv[1]) { 170 execvp(argv[1], &argv[1]); 171 err(1, "%s", argv[1]); 172 } 173 174 if (!(shell = getenv("SHELL"))) 175 shell = _PATH_BSHELL; 176 execlp(shell, shell, "-i", (char *)NULL); 177 err(1, "%s", shell); 178 /* NOTREACHED */ 179 } 180 181 static void 182 usage() 183 { 184 (void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 185 "[-u user] newroot [command]\n"); 186 exit(1); 187 } 188