jail.c revision 129848 
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 129848 2004-05-29 18:39:27Z 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 <pwd.h>
24#include <stdio.h>
25#include <stdlib.h>
26#include <string.h>
27#include <unistd.h>
28
29static void	usage(void);
30
31#define GET_USER_INFO do {						\
32	pwd = getpwnam(username);					\
33	if (pwd == NULL) {						\
34		if (errno)						\
35			err(1, "getpwnam: %s", username);		\
36		else							\
37			errx(1, "%s: no such user", username);		\
38	}								\
39	lcap = login_getpwclass(pwd);					\
40	if (lcap == NULL)						\
41		err(1, "getpwclass: %s", username);			\
42	ngroups = NGROUPS;						\
43	if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0)	\
44		err(1, "getgrouplist: %s", username);			\
45} while (0)
46
47int
48main(int argc, char **argv)
49{
50	login_cap_t *lcap;
51	struct jail j;
52	struct passwd *pwd;
53	struct in_addr in;
54	int ch, groups[NGROUPS], i, iflag, ngroups, uflag, Uflag;
55	char *username;
56
57	iflag = uflag = Uflag = 0;
58	username = NULL;
59
60	while ((ch = getopt(argc, argv, "iu:U:")) != -1) {
61		switch (ch) {
62		case 'i':
63			iflag = 1;
64			break;
65		case 'u':
66			username = optarg;
67			uflag = 1;
68			break;
69		case 'U':
70			username = optarg;
71			Uflag = 1;
72			break;
73		default:
74			usage();
75		}
76	}
77	argc -= optind;
78	argv += optind;
79	if (argc < 4)
80		usage();
81	if (uflag && Uflag)
82		usage();
83	if (uflag)
84		GET_USER_INFO;
85	if (chdir(argv[0]) != 0)
86		err(1, "chdir: %s", argv[0]);
87	memset(&j, 0, sizeof(j));
88	j.version = 0;
89	j.path = argv[0];
90	j.hostname = argv[1];
91	if (inet_aton(argv[2], &in) == 0)
92		errx(1, "Could not make sense of ip-number: %s", argv[2]);
93	j.ip_number = ntohl(in.s_addr);
94	i = jail(&j);
95	if (i == -1)
96		err(1, "jail");
97	if (iflag) {
98		printf("%d\n", i);
99		fflush(stdout);
100	}
101	if (username != NULL) {
102		if (Uflag)
103			GET_USER_INFO;
104		if (setgroups(ngroups, groups) != 0)
105			err(1, "setgroups");
106		if (setgid(pwd->pw_gid) != 0)
107			err(1, "setgid");
108		if (setusercontext(lcap, pwd, pwd->pw_uid,
109		    LOGIN_SETALL & ~LOGIN_SETGROUP) != 0)
110			err(1, "setusercontext");
111		login_close(lcap);
112	}
113	if (execv(argv[3], argv + 3) != 0)
114		err(1, "execv: %s", argv[3]);
115	exit(0);
116}
117
118static void
119usage(void)
120{
121
122	(void)fprintf(stderr, "%s%s\n",
123	     "usage: jail [-i] [-u username | -U username]",
124	     " path hostname ip-number command ...");
125	exit(1);
126}
127