jail.c revision 157790 
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 157790 2006-04-16 12:32:04Z 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 = NULL;
53	struct jail j;
54	struct passwd *pwd = NULL;
55	struct in_addr in;
56	gid_t groups[NGROUPS];
57	int ch, i, iflag, Jflag, lflag, ngroups, uflag, Uflag;
58	char path[PATH_MAX], *username, *JidFile;
59	static char *cleanenv;
60	const char *shell, *p = NULL;
61	FILE *fp;
62
63	iflag = Jflag = lflag = uflag = Uflag = 0;
64	username = JidFile = cleanenv = NULL;
65	fp = NULL;
66
67	while ((ch = getopt(argc, argv, "ilu:U:J:")) != -1) {
68		switch (ch) {
69		case 'i':
70			iflag = 1;
71			break;
72		case 'J':
73			JidFile = optarg;
74			Jflag = 1;
75			break;
76		case 'u':
77			username = optarg;
78			uflag = 1;
79			break;
80		case 'U':
81			username = optarg;
82			Uflag = 1;
83			break;
84		case 'l':
85			lflag = 1;
86			break;
87		default:
88			usage();
89		}
90	}
91	argc -= optind;
92	argv += optind;
93	if (argc < 4)
94		usage();
95	if (uflag && Uflag)
96		usage();
97	if (lflag && username == NULL)
98		usage();
99	if (uflag)
100		GET_USER_INFO;
101	if (realpath(argv[0], path) == NULL)
102		err(1, "realpath: %s", argv[0]);
103	if (chdir(path) != 0)
104		err(1, "chdir: %s", path);
105	memset(&j, 0, sizeof(j));
106	j.version = 0;
107	j.path = path;
108	j.hostname = argv[1];
109	if (inet_aton(argv[2], &in) == 0)
110		errx(1, "Could not make sense of ip-number: %s", argv[2]);
111	j.ip_number = ntohl(in.s_addr);
112	if (Jflag) {
113		fp = fopen(JidFile, "w");
114		if (fp == NULL)
115			errx(1, "Could not create JidFile: %s", JidFile);
116	}
117	i = jail(&j);
118	if (i == -1)
119		err(1, "jail");
120	if (iflag) {
121		printf("%d\n", i);
122		fflush(stdout);
123	}
124	if (Jflag) {
125		if (fp != NULL) {
126			fprintf(fp, "%d\t%s\t%s\t%s\t%s\n",
127			    i, j.path, j.hostname, argv[2], argv[3]);
128			(void)fclose(fp);
129		} else {
130			errx(1, "Could not write JidFile: %s", JidFile);
131		}
132	}
133	if (username != NULL) {
134		if (Uflag)
135			GET_USER_INFO;
136		if (lflag) {
137			p = getenv("TERM");
138			environ = &cleanenv;
139		}
140		if (setgroups(ngroups, groups) != 0)
141			err(1, "setgroups");
142		if (setgid(pwd->pw_gid) != 0)
143			err(1, "setgid");
144		if (setusercontext(lcap, pwd, pwd->pw_uid,
145		    LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN) != 0)
146			err(1, "setusercontext");
147		login_close(lcap);
148	}
149	if (lflag) {
150		if (*pwd->pw_shell)
151			shell = pwd->pw_shell;
152		else
153			shell = _PATH_BSHELL;
154		if (chdir(pwd->pw_dir) < 0)
155			errx(1, "no home directory");
156		setenv("HOME", pwd->pw_dir, 1);
157		setenv("SHELL", shell, 1);
158		setenv("USER", pwd->pw_name, 1);
159		if (p)
160			setenv("TERM", p, 1);
161	}
162	if (execv(argv[3], argv + 3) != 0)
163		err(1, "execv: %s", argv[3]);
164	exit(0);
165}
166
167static void
168usage(void)
169{
170
171	(void)fprintf(stderr, "%s%s\n",
172	     "usage: jail [-i] [-J jid_file] [-l -u username | -U username]",
173	     " path hostname ip-number command ...");
174	exit(1);
175}
176