xref: /freebsd/sys/kern/kern_jail.c (revision 1d66272a85cde1c8a69c58f4b5dd649babd6eca6)
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  * $FreeBSD$
10  *
11  */
12 
13 #include <sys/param.h>
14 #include <sys/types.h>
15 #include <sys/kernel.h>
16 #include <sys/systm.h>
17 #include <sys/errno.h>
18 #include <sys/sysproto.h>
19 #include <sys/malloc.h>
20 #include <sys/proc.h>
21 #include <sys/jail.h>
22 #include <sys/socket.h>
23 #include <sys/sysctl.h>
24 #include <net/if.h>
25 #include <netinet/in.h>
26 
27 MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
28 
29 SYSCTL_NODE(, OID_AUTO, jail, CTLFLAG_RW, 0,
30     "Jail rules");
31 
32 int	jail_set_hostname_allowed = 1;
33 SYSCTL_INT(_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW,
34     &jail_set_hostname_allowed, 0,
35     "Processes in jail can set their hostnames");
36 
37 int	jail_socket_unixiproute_only = 1;
38 SYSCTL_INT(_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW,
39     &jail_socket_unixiproute_only, 0,
40     "Processes in jail are limited to creating UNIX/IPv4/route sockets only");
41 
42 int	jail_sysvipc_allowed = 0;
43 SYSCTL_INT(_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW,
44     &jail_sysvipc_allowed, 0,
45     "Processes in jail can use System V IPC primitives");
46 
47 int
48 jail(p, uap)
49         struct proc *p;
50         struct jail_args /* {
51                 syscallarg(struct jail *) jail;
52         } */ *uap;
53 {
54 	int error;
55 	struct prison *pr;
56 	struct jail j;
57 	struct chroot_args ca;
58 
59 	error = suser(p);
60 	if (error)
61 		return (error);
62 	error = copyin(uap->jail, &j, sizeof j);
63 	if (error)
64 		return (error);
65 	if (j.version != 0)
66 		return (EINVAL);
67 	MALLOC(pr, struct prison *, sizeof *pr , M_PRISON, M_WAITOK | M_ZERO);
68 	error = copyinstr(j.hostname, &pr->pr_host, sizeof pr->pr_host, 0);
69 	if (error)
70 		goto bail;
71 	pr->pr_ip = j.ip_number;
72 
73 	ca.path = j.path;
74 	error = chroot(p, &ca);
75 	if (error)
76 		goto bail;
77 
78 	pr->pr_ref++;
79 	p->p_prison = pr;
80 	p->p_flag |= P_JAILED;
81 	return (0);
82 
83 bail:
84 	FREE(pr, M_PRISON);
85 	return (error);
86 }
87 
88 int
89 prison_ip(struct proc *p, int flag, u_int32_t *ip)
90 {
91 	u_int32_t tmp;
92 
93 	if (!p->p_prison)
94 		return (0);
95 	if (flag)
96 		tmp = *ip;
97 	else
98 		tmp = ntohl(*ip);
99 	if (tmp == INADDR_ANY) {
100 		if (flag)
101 			*ip = p->p_prison->pr_ip;
102 		else
103 			*ip = htonl(p->p_prison->pr_ip);
104 		return (0);
105 	}
106 	if (p->p_prison->pr_ip != tmp)
107 		return (1);
108 	return (0);
109 }
110 
111 void
112 prison_remote_ip(struct proc *p, int flag, u_int32_t *ip)
113 {
114 	u_int32_t tmp;
115 
116 	if (!p || !p->p_prison)
117 		return;
118 	if (flag)
119 		tmp = *ip;
120 	else
121 		tmp = ntohl(*ip);
122 	if (tmp == 0x7f000001) {
123 		if (flag)
124 			*ip = p->p_prison->pr_ip;
125 		else
126 			*ip = htonl(p->p_prison->pr_ip);
127 		return;
128 	}
129 	return;
130 }
131 
132 int
133 prison_if(struct proc *p, struct sockaddr *sa)
134 {
135 	struct sockaddr_in *sai = (struct sockaddr_in*) sa;
136 	int ok;
137 
138 	if ((sai->sin_family != AF_INET) && jail_socket_unixiproute_only)
139 		ok = 1;
140 	else if (sai->sin_family != AF_INET)
141 		ok = 0;
142 	else if (p->p_prison->pr_ip != ntohl(sai->sin_addr.s_addr))
143 		ok = 1;
144 	else
145 		ok = 0;
146 	return (ok);
147 }
148