1/*-
2 * Copyright (c) 1999 Poul-Henning Kamp.
3 * Copyright (c) 2008 Bjoern A. Zeeb.
4 * Copyright (c) 2009 James Gritton.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30#include "opt_ddb.h"
31#include "opt_inet.h"
32#include "opt_inet6.h"
33
34#include <sys/param.h>
35#include <sys/types.h>
36#include <sys/kernel.h>
37#include <sys/systm.h>
38#include <sys/errno.h>
39#include <sys/sysproto.h>
40#include <sys/malloc.h>
41#include <sys/osd.h>
42#include <sys/priv.h>
43#include <sys/proc.h>
44#include <sys/taskqueue.h>
45#include <sys/fcntl.h>
46#include <sys/jail.h>
47#include <sys/lock.h>
48#include <sys/mutex.h>
49#include <sys/racct.h>
50#include <sys/refcount.h>
51#include <sys/sx.h>
52#include <sys/namei.h>
53#include <sys/mount.h>
54#include <sys/queue.h>
55#include <sys/socket.h>
56#include <sys/syscallsubr.h>
57#include <sys/sysctl.h>
58#include <sys/vnode.h>
59
60#include <net/if.h>
61#include <net/vnet.h>
62
63#include <netinet/in.h>
64
65static in_addr_t
66prison_primary_ip4(const struct prison *pr)
67{
68
69	return (((const struct in_addr *)prison_ip_get0(pr, PR_INET))->s_addr);
70}
71
72int
73prison_qcmp_v4(const void *ip1, const void *ip2)
74{
75	in_addr_t iaa, iab;
76
77	/*
78	 * We need to compare in HBO here to get the list sorted as expected
79	 * by the result of the code.  Sorting NBO addresses gives you
80	 * interesting results.  If you do not understand, do not try.
81	 */
82	iaa = ntohl(((const struct in_addr *)ip1)->s_addr);
83	iab = ntohl(((const struct in_addr *)ip2)->s_addr);
84
85	/*
86	 * Do not simply return the difference of the two numbers, the int is
87	 * not wide enough.
88	 */
89	if (iaa > iab)
90		return (1);
91	else if (iaa < iab)
92		return (-1);
93	else
94		return (0);
95}
96
97bool
98prison_valid_v4(const void *ip)
99{
100	in_addr_t ia = ((const struct in_addr *)ip)->s_addr;
101
102	/*
103	 * We do not have to care about byte order for these
104	 * checks so we will do them in NBO.
105	 */
106	return (ia != INADDR_ANY && ia != INADDR_BROADCAST);
107}
108
109/*
110 * Pass back primary IPv4 address of this jail.
111 *
112 * If not restricted return success but do not alter the address.  Caller has
113 * to make sure to initialize it correctly (e.g. INADDR_ANY).
114 *
115 * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
116 * Address returned in NBO.
117 */
118int
119prison_get_ip4(struct ucred *cred, struct in_addr *ia)
120{
121	struct prison *pr;
122
123	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
124	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
125
126	pr = cred->cr_prison;
127	if (!(pr->pr_flags & PR_IP4))
128		return (0);
129	mtx_lock(&pr->pr_mtx);
130	if (!(pr->pr_flags & PR_IP4)) {
131		mtx_unlock(&pr->pr_mtx);
132		return (0);
133	}
134	if (pr->pr_addrs[PR_INET] == NULL) {
135		mtx_unlock(&pr->pr_mtx);
136		return (EAFNOSUPPORT);
137	}
138
139	ia->s_addr = prison_primary_ip4(pr);
140	mtx_unlock(&pr->pr_mtx);
141	return (0);
142}
143
144/*
145 * Return true if we should do proper source address selection or are not jailed.
146 * We will return false if we should bypass source address selection in favour
147 * of the primary jail IPv4 address. Only in this case *ia will be updated and
148 * returned in NBO.
149 * Return true, even in case this jail does not allow IPv4.
150 */
151bool
152prison_saddrsel_ip4(struct ucred *cred, struct in_addr *ia)
153{
154	struct prison *pr;
155	struct in_addr lia;
156
157	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
158	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
159
160	if (!jailed(cred))
161		return (true);
162
163	pr = cred->cr_prison;
164	if (pr->pr_flags & PR_IP4_SADDRSEL)
165		return (true);
166
167	lia.s_addr = INADDR_ANY;
168	if (prison_get_ip4(cred, &lia) != 0)
169		return (true);
170	if (lia.s_addr == INADDR_ANY)
171		return (true);
172
173	ia->s_addr = lia.s_addr;
174	return (false);
175}
176
177/*
178 * Return true if pr1 and pr2 have the same IPv4 address restrictions.
179 */
180bool
181prison_equal_ip4(struct prison *pr1, struct prison *pr2)
182{
183
184	if (pr1 == pr2)
185		return (true);
186
187	/*
188	 * No need to lock since the PR_IP4_USER flag can't be altered for
189	 * existing prisons.
190	 */
191	while (pr1 != &prison0 &&
192#ifdef VIMAGE
193	       !(pr1->pr_flags & PR_VNET) &&
194#endif
195	       !(pr1->pr_flags & PR_IP4_USER))
196		pr1 = pr1->pr_parent;
197	while (pr2 != &prison0 &&
198#ifdef VIMAGE
199	       !(pr2->pr_flags & PR_VNET) &&
200#endif
201	       !(pr2->pr_flags & PR_IP4_USER))
202		pr2 = pr2->pr_parent;
203	return (pr1 == pr2);
204}
205
206/*
207 * Make sure our (source) address is set to something meaningful to this
208 * jail.
209 *
210 * Returns 0 if jail doesn't restrict IPv4 or if address belongs to jail,
211 * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
212 * doesn't allow IPv4.  Address passed in in NBO and returned in NBO.
213 */
214int
215prison_local_ip4(struct ucred *cred, struct in_addr *ia)
216{
217	struct prison *pr;
218	struct in_addr ia0;
219	int error;
220
221	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
222	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
223
224	pr = cred->cr_prison;
225	if (!(pr->pr_flags & PR_IP4))
226		return (0);
227	mtx_lock(&pr->pr_mtx);
228	if (!(pr->pr_flags & PR_IP4)) {
229		mtx_unlock(&pr->pr_mtx);
230		return (0);
231	}
232	if (pr->pr_addrs[PR_INET] == NULL) {
233		mtx_unlock(&pr->pr_mtx);
234		return (EAFNOSUPPORT);
235	}
236
237	ia0.s_addr = ntohl(ia->s_addr);
238
239	if (ia0.s_addr == INADDR_ANY) {
240		/*
241		 * In case there is only 1 IPv4 address, bind directly.
242		 */
243		if (prison_ip_cnt(pr, PR_INET) == 1)
244			ia->s_addr = prison_primary_ip4(pr);
245		mtx_unlock(&pr->pr_mtx);
246		return (0);
247	}
248
249	error = prison_check_ip4_locked(pr, ia);
250	if (error == EADDRNOTAVAIL && ia0.s_addr == INADDR_LOOPBACK) {
251		ia->s_addr = prison_primary_ip4(pr);
252		error = 0;
253	}
254
255	mtx_unlock(&pr->pr_mtx);
256	return (error);
257}
258
259/*
260 * Rewrite destination address in case we will connect to loopback address.
261 *
262 * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
263 * Address passed in in NBO and returned in NBO.
264 */
265int
266prison_remote_ip4(struct ucred *cred, struct in_addr *ia)
267{
268	struct prison *pr;
269
270	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
271	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
272
273	pr = cred->cr_prison;
274	if (!(pr->pr_flags & PR_IP4))
275		return (0);
276	mtx_lock(&pr->pr_mtx);
277	if (!(pr->pr_flags & PR_IP4)) {
278		mtx_unlock(&pr->pr_mtx);
279		return (0);
280	}
281	if (pr->pr_addrs[PR_INET] == NULL) {
282		mtx_unlock(&pr->pr_mtx);
283		return (EAFNOSUPPORT);
284	}
285
286	if (ntohl(ia->s_addr) == INADDR_LOOPBACK &&
287	    prison_check_ip4_locked(pr, ia) == EADDRNOTAVAIL) {
288		ia->s_addr = prison_primary_ip4(pr);
289		mtx_unlock(&pr->pr_mtx);
290		return (0);
291	}
292
293	/*
294	 * Return success because nothing had to be changed.
295	 */
296	mtx_unlock(&pr->pr_mtx);
297	return (0);
298}
299
300/*
301 * Check if given address belongs to the jail referenced by cred/prison.
302 *
303 * Returns 0 if address belongs to jail,
304 * EADDRNOTAVAIL if the address doesn't belong to the jail.
305 */
306int
307prison_check_ip4_locked(const struct prison *pr, const struct in_addr *ia)
308{
309
310	if (!(pr->pr_flags & PR_IP4))
311		return (0);
312
313	return (prison_ip_check(pr, PR_INET, ia));
314}
315
316int
317prison_check_ip4(const struct ucred *cred, const struct in_addr *ia)
318{
319	struct prison *pr;
320	int error;
321
322	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
323	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
324
325	pr = cred->cr_prison;
326	if (!(pr->pr_flags & PR_IP4))
327		return (0);
328	mtx_lock(&pr->pr_mtx);
329	if (!(pr->pr_flags & PR_IP4)) {
330		mtx_unlock(&pr->pr_mtx);
331		return (0);
332	}
333	if (pr->pr_addrs[PR_INET] == NULL) {
334		mtx_unlock(&pr->pr_mtx);
335		return (EAFNOSUPPORT);
336	}
337
338	error = prison_check_ip4_locked(pr, ia);
339	mtx_unlock(&pr->pr_mtx);
340	return (error);
341}
342