jail.c revision 133743 
1/*
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 */
9
10#include <sys/cdefs.h>
11__FBSDID("$FreeBSD: head/usr.sbin/jail/jail.c 133743 2004-08-15 08:21:50Z maxim $");
12
13#include <sys/param.h>
14#include <sys/jail.h>
15
16#include <netinet/in.h>
17#include <arpa/inet.h>
18
19#include <err.h>
20#include <errno.h>
21#include <grp.h>
22#include <login_cap.h>
23#include <paths.h>
24#include <pwd.h>
25#include <stdio.h>
26#include <stdlib.h>
27#include <string.h>
28#include <unistd.h>
29
30static void	usage(void);
31extern char	**environ;
32
33#define GET_USER_INFO do {						\
34	pwd = getpwnam(username);					\
35	if (pwd == NULL) {						\
36		if (errno)						\
37			err(1, "getpwnam: %s", username);		\
38		else							\
39			errx(1, "%s: no such user", username);		\
40	}								\
41	lcap = login_getpwclass(pwd);					\
42	if (lcap == NULL)						\
43		err(1, "getpwclass: %s", username);			\
44	ngroups = NGROUPS;						\
45	if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0)	\
46		err(1, "getgrouplist: %s", username);			\
47} while (0)
48
49int
50main(int argc, char **argv)
51{
52	login_cap_t *lcap;
53	struct jail j;
54	struct passwd *pwd;
55	struct in_addr in;
56	int ch, groups[NGROUPS], i, iflag, lflag, ngroups, uflag, Uflag;
57	char path[PATH_MAX], *username;
58	static char *cleanenv;
59	const char *shell, *p;
60
61	iflag = lflag = uflag = Uflag = 0;
62	username = cleanenv = NULL;
63
64	while ((ch = getopt(argc, argv, "ilu:U:")) != -1) {
65		switch (ch) {
66		case 'i':
67			iflag = 1;
68			break;
69		case 'u':
70			username = optarg;
71			uflag = 1;
72			break;
73		case 'U':
74			username = optarg;
75			Uflag = 1;
76			break;
77		case 'l':
78			lflag = 1;
79			break;
80		default:
81			usage();
82		}
83	}
84	argc -= optind;
85	argv += optind;
86	if (argc < 4)
87		usage();
88	if (uflag && Uflag)
89		usage();
90	if (lflag && username == NULL)
91		usage();
92	if (uflag)
93		GET_USER_INFO;
94	if (realpath(argv[0], path) == NULL)
95		err(1, "realpath: %s", argv[0]);
96	if (chdir(path) != 0)
97		err(1, "chdir: %s", path);
98	memset(&j, 0, sizeof(j));
99	j.version = 0;
100	j.path = path;
101	j.hostname = argv[1];
102	if (inet_aton(argv[2], &in) == 0)
103		errx(1, "Could not make sense of ip-number: %s", argv[2]);
104	j.ip_number = ntohl(in.s_addr);
105	i = jail(&j);
106	if (i == -1)
107		err(1, "jail");
108	if (iflag) {
109		printf("%d\n", i);
110		fflush(stdout);
111	}
112	if (username != NULL) {
113		if (Uflag)
114			GET_USER_INFO;
115		if (lflag) {
116			p = getenv("TERM");
117			environ = &cleanenv;
118		}
119		if (setgroups(ngroups, groups) != 0)
120			err(1, "setgroups");
121		if (setgid(pwd->pw_gid) != 0)
122			err(1, "setgid");
123		if (setusercontext(lcap, pwd, pwd->pw_uid,
124		    LOGIN_SETALL & ~LOGIN_SETGROUP) != 0)
125			err(1, "setusercontext");
126		login_close(lcap);
127	}
128	if (lflag) {
129		if (*pwd->pw_shell)
130			shell = pwd->pw_shell;
131		else
132			shell = _PATH_BSHELL;
133		if (chdir(pwd->pw_dir) < 0)
134			errx(1, "no home directory");
135		setenv("HOME", pwd->pw_dir, 1);
136		setenv("SHELL", shell, 1);
137		setenv("USER", pwd->pw_name, 1);
138		if (p)
139			setenv("TERM", p, 1);
140	}
141	if (execv(argv[3], argv + 3) != 0)
142		err(1, "execv: %s", argv[3]);
143	exit(0);
144}
145
146static void
147usage(void)
148{
149
150	(void)fprintf(stderr, "%s%s\n",
151	     "usage: jail [-i] [-l -u username | -U username]",
152	     " path hostname ip-number command ...");
153	exit(1);
154}
155