jail.c revision 112705 
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 * $FreeBSD: head/usr.sbin/jail/jail.c 112705 2003-03-27 12:16:58Z maxim $
10 *
11 */
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 <grp.h>
21#include <login_cap.h>
22#include <pwd.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26#include <unistd.h>
27
28static void	usage(void);
29
30int
31main(int argc, char **argv)
32{
33	login_cap_t *lcap;
34	struct jail j;
35	struct passwd *pwd;
36	struct in_addr in;
37	int ch, groups[NGROUPS], i, ngroups;
38	char *username;
39
40	username = NULL;
41
42	while ((ch = getopt(argc, argv, "u:")) != -1)
43		switch (ch) {
44		case 'u':
45			username = optarg;
46			break;
47		default:
48			usage();
49			break;
50		}
51	argc -= optind;
52	argv += optind;
53	if (argc < 4)
54		usage();
55
56	if (username != NULL) {
57		pwd = getpwnam(username);
58		if (pwd == NULL)
59			err(1, "getpwnam %s", username);
60		lcap = login_getpwclass(pwd);
61		if (lcap == NULL)
62			err(1, "getpwclass failed", username);
63		ngroups = NGROUPS;
64		i = getgrouplist(username, pwd->pw_gid, groups, &ngroups);
65		if (i)
66			err(1, "getgrouplist %s", username);
67	}
68	i = chdir(argv[0]);
69	if (i)
70		err(1, "chdir %s", argv[0]);
71	memset(&j, 0, sizeof(j));
72	j.version = 0;
73	j.path = argv[0];
74	j.hostname = argv[1];
75	i = inet_aton(argv[2], &in);
76	if (!i)
77		errx(1, "Couldn't make sense of ip-number\n");
78	j.ip_number = ntohl(in.s_addr);
79	i = jail(&j);
80	if (i)
81		err(1, "Imprisonment failed");
82	if (username != NULL) {
83		i = setgroups(ngroups, groups);
84		if (i)
85			err(1, "setgroups failed");
86		i = setgid(pwd->pw_gid);
87		if (i)
88			err(1, "setgid failed");
89		i = setusercontext(lcap, pwd, pwd->pw_uid,
90		    LOGIN_SETALL & ~LOGIN_SETGROUP);
91		if (i)
92			err(1, "setusercontext failed");
93	}
94	i = execv(argv[3], argv + 3);
95	if (i)
96		err(1, "execv(%s)", argv[3]);
97	exit (0);
98}
99
100static void
101usage(void)
102{
103
104	errx(1,
105	    "Usage: jail [-u username] path hostname ip-number command ...");
106}
107