1 /* $NetBSD: chroot.c,v 1.12 2001/07/14 21:56:45 manu Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)chroot.c 8.1 (Berkeley) 6/9/93"; 45 #else 46 __RCSID("$NetBSD: chroot.c,v 1.12 2001/07/14 21:56:45 manu Exp $"); 47 #endif 48 #endif /* not lint */ 49 50 #include <sys/param.h> 51 52 #include <ctype.h> 53 #include <err.h> 54 #include <errno.h> 55 #include <grp.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 int main(int, char **); 64 void usage(void) __attribute__((__noreturn__)); 65 66 char *user; /* user to switch to before running program */ 67 char *group; /* group to switch to ... */ 68 char *grouplist; /* group list to switch to ... */ 69 70 int 71 main(int argc, char *argv[]) 72 { 73 struct group *gp; 74 struct passwd *pw; 75 char *endp, *p; 76 const char *shell; 77 gid_t gid, gidlist[NGROUPS_MAX]; 78 uid_t uid; 79 int ch, gids; 80 81 gid = 0; 82 uid = 0; 83 while ((ch = getopt(argc, argv, "G:g:u:")) != -1) { 84 switch(ch) { 85 case 'u': 86 user = optarg; 87 if (*user == '\0') 88 usage(); 89 break; 90 case 'g': 91 group = optarg; 92 if (*group == '\0') 93 usage(); 94 break; 95 case 'G': 96 grouplist = optarg; 97 if (*grouplist == '\0') 98 usage(); 99 break; 100 case '?': 101 default: 102 usage(); 103 } 104 } 105 argc -= optind; 106 argv += optind; 107 108 if (argc < 1) 109 usage(); 110 111 if (group != NULL) { 112 if (isdigit((unsigned char)*group)) { 113 gid = (gid_t)strtoul(group, &endp, 0); 114 if (*endp != '\0') 115 goto getgroup; 116 } else { 117 getgroup: 118 if ((gp = getgrnam(group)) != NULL) 119 gid = gp->gr_gid; 120 else 121 errx(1, "no such group `%s'", group); 122 } 123 } 124 125 for (gids = 0; 126 (p = strsep(&grouplist, ",")) != NULL && gids < NGROUPS_MAX; ) { 127 if (*p == '\0') 128 continue; 129 130 if (isdigit((unsigned char)*p)) { 131 gidlist[gids] = (gid_t)strtoul(p, &endp, 0); 132 if (*endp != '\0') 133 goto getglist; 134 } else { 135 getglist: 136 if ((gp = getgrnam(p)) != NULL) 137 gidlist[gids] = gp->gr_gid; 138 else 139 errx(1, "no such group `%s'", p); 140 } 141 gids++; 142 } 143 if (p != NULL && gids == NGROUPS_MAX) 144 errx(1, "too many supplementary groups provided"); 145 146 if (user != NULL) { 147 if (isdigit((unsigned char)*user)) { 148 uid = (uid_t)strtoul(user, &endp, 0); 149 if (*endp != '\0') 150 goto getuser; 151 } else { 152 getuser: 153 if ((pw = getpwnam(user)) != NULL) 154 uid = pw->pw_uid; 155 else 156 errx(1, "no such user `%s'", user); 157 } 158 } 159 160 if (chdir(argv[0]) == -1 || chroot(".") == -1) 161 err(1, "%s", argv[0]); 162 163 if (gids && setgroups(gids, gidlist) == -1) 164 err(1, "setgroups"); 165 if (group && setgid(gid) == -1) 166 err(1, "setgid"); 167 if (user && setuid(uid) == -1) 168 err(1, "setuid"); 169 170 if (argv[1]) { 171 execvp(argv[1], &argv[1]); 172 err(1, "%s", argv[1]); 173 } 174 175 if ((shell = getenv("SHELL")) == NULL) 176 shell = _PATH_BSHELL; 177 execlp(shell, shell, "-i", NULL); 178 err(1, "%s", shell); 179 /* NOTREACHED */ 180 } 181 182 void 183 usage(void) 184 { 185 186 (void)fprintf(stderr, "usage: chroot [-g group] [-G group,group,...] " 187 "[-u user] newroot [command]\n"); 188 exit(1); 189 } 190