xref: /dragonfly/usr.sbin/jail/jail.c (revision f746689a)
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: src/usr.sbin/jail/jail.c,v 1.5.2.2 2003/05/08 13:04:24 maxim Exp $
10  * $DragonFly: src/usr.sbin/jail/jail.c,v 1.8 2007/01/17 10:37:48 victor Exp $
11  *
12  */
13 
14 #include <sys/param.h>
15 #include <sys/jail.h>
16 
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
19 
20 #include <err.h>
21 #include <errno.h>
22 #include <grp.h>
23 #include <login_cap.h>
24 #include <paths.h>
25 #include <pwd.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 
31 static void	usage(void);
32 extern char	**environ;
33 
34 #define GET_USER_INFO do {						\
35 	pwd = getpwnam(username);					\
36 	if (pwd == NULL) {						\
37 		if (errno)						\
38 			err(1, "getpwnam: %s", username);		\
39 		else							\
40 			errx(1, "%s: no such user", username);		\
41 	}								\
42 	lcap = login_getpwclass(pwd);					\
43 	if (lcap == NULL)						\
44 		err(1, "getpwclass: %s", username);			\
45 	ngroups = NGROUPS;						\
46 	if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0)	\
47 		err(1, "getgrouplist: %s", username);			\
48 } while (0)
49 
50 int
51 main(int argc, char **argv)
52 {
53 	login_cap_t *lcap = NULL;
54 	struct jail j;
55 	struct sockaddr_in *sin4;
56 	struct sockaddr_in6 *sin6;
57 	struct passwd *pwd = NULL;
58 	gid_t groups[NGROUPS];
59 	int ch, ngroups, i, iflag, lflag, uflag, Uflag;
60 	static char *cleanenv;
61 	const char *shell, *p = NULL;
62 	char path[PATH_MAX], *username, *curpos;
63 
64 	iflag = lflag = uflag = Uflag = 0;
65 	username = NULL;
66 	j.ips = malloc(sizeof(struct sockaddr_storage)*20);
67 	bzero(j.ips, sizeof(struct sockaddr_storage)*20);
68 
69 	while ((ch = getopt(argc, argv, "ilu:U:")) != -1)
70 		switch (ch) {
71 		case 'i':
72 			iflag = 1;
73 			break;
74 		case 'l':
75 			lflag = 1;
76 			break;
77 		case 'u':
78 			username = optarg;
79 			uflag = 1;
80 			break;
81 		case 'U':
82 			username = optarg;
83 			Uflag = 1;
84 			break;
85 		default:
86 			usage();
87 			break;
88 		}
89 	argc -= optind;
90 	argv += optind;
91 	if (argc < 4)
92 		usage();
93 	if (uflag && Uflag)
94 		usage();
95 	if (lflag && username == NULL)
96 		usage();
97 	if (uflag)
98 		GET_USER_INFO;
99 	if (realpath(argv[0], path) == NULL)
100 		err(1, "realpath: %s", argv[0]);
101 	if (chdir(path) != 0)
102 		err(1, "chdir: %s", path);
103 
104 	j.version = 1;
105 	j.path = path;
106 	j.hostname = argv[1];
107 	curpos = strtok(argv[2], ",");
108 	for (i=0; curpos != NULL; i++) {
109 		if (i && i%20 == 0) {
110 			if ( (j.ips = realloc(j.ips, sizeof(struct sockaddr_storage)*i+20)) == NULL) {
111 				perror("Can't allocate memory");
112 				exit(1);
113 			}
114 		}
115 
116 		sin4 = (struct sockaddr_in *)(j.ips+i);
117 		sin6 = (struct sockaddr_in6 *)(j.ips+i);
118 
119 		if (inet_pton(AF_INET, curpos, &sin4->sin_addr) == 1) {
120 			sin4->sin_family = AF_INET;
121 		} else {
122 			if (inet_pton(AF_INET6, curpos, &sin6->sin6_addr) == 1) {
123 				sin6->sin6_family = AF_INET6;
124 			} else {
125 				printf("Invalid value %s\n", curpos);
126 				exit(1);
127 			}
128 		}
129 		curpos = strtok(NULL, ",");
130 	}
131 
132 	j.n_ips = i;
133 	i = jail(&j);
134 	if (i == -1)
135 		err(1, "jail");
136 	if (iflag) {
137 		printf("%d\n", i);
138 		fflush(stdout);
139 	}
140 	if (username != NULL) {
141 		if (Uflag)
142 			GET_USER_INFO;
143 		if (lflag) {
144 			p = getenv("TERM");
145 			environ = &cleanenv;
146 		}
147 		if (setgroups(ngroups, groups) != 0)
148 			err(1, "setgroups");
149 		if (setgid(pwd->pw_gid) != 0)
150 			err(1, "setgid");
151 		if (setusercontext(lcap, pwd, pwd->pw_uid,
152 		    LOGIN_SETALL & ~LOGIN_SETGROUP) != 0)
153 			err(1, "setusercontext");
154 		login_close(lcap);
155 	}
156 	if (lflag) {
157 		if (*pwd->pw_shell)
158 			shell = pwd->pw_shell;
159 		else
160 			shell = _PATH_BSHELL;
161 		if (chdir(pwd->pw_dir) < 0)
162 			errx(1, "no home directory");
163 		setenv("HOME", pwd->pw_dir, 1);
164 		setenv("SHELL", shell, 1);
165 		setenv("USER", pwd->pw_name, 1);
166 		if (p)
167 			setenv("TERM", p, 1);
168 	}
169 	if (execv(argv[3], argv + 3) != 0)
170 		err(1, "execv: %s", argv[3]);
171 	exit (0);
172 }
173 
174 static void
175 usage(void)
176 {
177 
178 	fprintf(stderr, "%s\n",
179 	    "Usage: jail [-i] [-l -u username | -U username] path hostname ip-list command ...");
180 	exit(1);
181 }
182