xref: /netbsd-src/sys/netipsec/keysock.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55) 
1 /*	$NetBSD: keysock.c,v 1.29 2014/07/01 05:49:19 rtr Exp $	*/
2 /*	$FreeBSD: src/sys/netipsec/keysock.c,v 1.3.2.1 2003/01/24 05:11:36 sam Exp $	*/
3 /*	$KAME: keysock.c,v 1.25 2001/08/13 20:07:41 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: keysock.c,v 1.29 2014/07/01 05:49:19 rtr Exp $");
36 
37 #include "opt_ipsec.h"
38 
39 /* This code has derived from sys/net/rtsock.c on FreeBSD2.2.5 */
40 
41 #include <sys/types.h>
42 #include <sys/param.h>
43 #include <sys/domain.h>
44 #include <sys/errno.h>
45 #include <sys/kernel.h>
46 #include <sys/kmem.h>
47 #include <sys/mbuf.h>
48 #include <sys/protosw.h>
49 #include <sys/signalvar.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/sysctl.h>
53 #include <sys/systm.h>
54 
55 #include <net/raw_cb.h>
56 #include <net/route.h>
57 
58 #include <net/pfkeyv2.h>
59 #include <netipsec/key.h>
60 #include <netipsec/keysock.h>
61 #include <netipsec/key_debug.h>
62 
63 #include <netipsec/ipsec_osdep.h>
64 #include <netipsec/ipsec_private.h>
65 
66 typedef int	pr_output_t (struct mbuf *, struct socket *);
67 
68 struct key_cb {
69 	int key_count;
70 	int any_count;
71 };
72 static struct key_cb key_cb;
73 
74 static struct sockaddr key_dst = {
75     .sa_len = 2,
76     .sa_family = PF_KEY,
77 };
78 static struct sockaddr key_src = {
79     .sa_len = 2,
80     .sa_family = PF_KEY,
81 };
82 
83 
84 static int key_sendup0(struct rawcb *, struct mbuf *, int, int);
85 
86 int key_registered_sb_max = (2048 * MHLEN); /* XXX arbitrary */
87 
88 /*
89  * key_output()
90  */
91 int
92 key_output(struct mbuf *m, ...)
93 {
94 	struct sadb_msg *msg;
95 	int len, error = 0;
96 	int s;
97 	struct socket *so;
98 	va_list ap;
99 
100 	va_start(ap, m);
101 	so = va_arg(ap, struct socket *);
102 	va_end(ap);
103 
104 	if (m == 0)
105 		panic("key_output: NULL pointer was passed");
106 
107 	{
108 		uint64_t *ps = PFKEY_STAT_GETREF();
109 		ps[PFKEY_STAT_OUT_TOTAL]++;
110 		ps[PFKEY_STAT_OUT_BYTES] += m->m_pkthdr.len;
111 		PFKEY_STAT_PUTREF();
112 	}
113 
114 	len = m->m_pkthdr.len;
115 	if (len < sizeof(struct sadb_msg)) {
116 		PFKEY_STATINC(PFKEY_STAT_OUT_TOOSHORT);
117 		error = EINVAL;
118 		goto end;
119 	}
120 
121 	if (m->m_len < sizeof(struct sadb_msg)) {
122 		if ((m = m_pullup(m, sizeof(struct sadb_msg))) == 0) {
123 			PFKEY_STATINC(PFKEY_STAT_OUT_NOMEM);
124 			error = ENOBUFS;
125 			goto end;
126 		}
127 	}
128 
129 	if ((m->m_flags & M_PKTHDR) == 0)
130 		panic("key_output: not M_PKTHDR ??");
131 
132 	KEYDEBUG(KEYDEBUG_KEY_DUMP, kdebug_mbuf(m));
133 
134 	msg = mtod(m, struct sadb_msg *);
135 	PFKEY_STATINC(PFKEY_STAT_OUT_MSGTYPE + msg->sadb_msg_type);
136 	if (len != PFKEY_UNUNIT64(msg->sadb_msg_len)) {
137 		PFKEY_STATINC(PFKEY_STAT_OUT_INVLEN);
138 		error = EINVAL;
139 		goto end;
140 	}
141 
142 	/*XXX giant lock*/
143 	s = splsoftnet();
144 	error = key_parse(m, so);
145 	m = NULL;
146 	splx(s);
147 end:
148 	if (m)
149 		m_freem(m);
150 	return error;
151 }
152 
153 /*
154  * send message to the socket.
155  */
156 static int
157 key_sendup0(
158     struct rawcb *rp,
159     struct mbuf *m,
160     int promisc,
161     int sbprio
162 )
163 {
164 	int error;
165 	int ok;
166 
167 	if (promisc) {
168 		struct sadb_msg *pmsg;
169 
170 		M_PREPEND(m, sizeof(struct sadb_msg), M_DONTWAIT);
171 		if (m && m->m_len < sizeof(struct sadb_msg))
172 			m = m_pullup(m, sizeof(struct sadb_msg));
173 		if (!m) {
174 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
175 			return ENOBUFS;
176 		}
177 		m->m_pkthdr.len += sizeof(*pmsg);
178 
179 		pmsg = mtod(m, struct sadb_msg *);
180 		memset(pmsg, 0, sizeof(*pmsg));
181 		pmsg->sadb_msg_version = PF_KEY_V2;
182 		pmsg->sadb_msg_type = SADB_X_PROMISC;
183 		pmsg->sadb_msg_len = PFKEY_UNIT64(m->m_pkthdr.len);
184 		/* pid and seq? */
185 
186 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTYPE + pmsg->sadb_msg_type);
187 	}
188 
189 	if (sbprio == 0)
190 		ok = sbappendaddr(&rp->rcb_socket->so_rcv,
191 			       (struct sockaddr *)&key_src, m, NULL);
192 	else
193 		ok = sbappendaddrchain(&rp->rcb_socket->so_rcv,
194 			       (struct sockaddr *)&key_src, m, sbprio);
195 
196 	  if (!ok) {
197 		PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
198 		m_freem(m);
199 		error = ENOBUFS;
200 	} else
201 		error = 0;
202 	sorwakeup(rp->rcb_socket);
203 	return error;
204 }
205 
206 /* XXX this interface should be obsoleted. */
207 int
208 key_sendup(struct socket *so, struct sadb_msg *msg, u_int len,
209 	   int target)	/*target of the resulting message*/
210 {
211 	struct mbuf *m, *n, *mprev;
212 	int tlen;
213 
214 	/* sanity check */
215 	if (so == 0 || msg == 0)
216 		panic("key_sendup: NULL pointer was passed");
217 
218 	KEYDEBUG(KEYDEBUG_KEY_DUMP,
219 		printf("key_sendup: \n");
220 		kdebug_sadb(msg));
221 
222 	/*
223 	 * we increment statistics here, just in case we have ENOBUFS
224 	 * in this function.
225 	 */
226 	{
227 		uint64_t *ps = PFKEY_STAT_GETREF();
228 		ps[PFKEY_STAT_IN_TOTAL]++;
229 		ps[PFKEY_STAT_IN_BYTES] += len;
230 		ps[PFKEY_STAT_IN_MSGTYPE + msg->sadb_msg_type]++;
231 		PFKEY_STAT_PUTREF();
232 	}
233 
234 	/*
235 	 * Get mbuf chain whenever possible (not clusters),
236 	 * to save socket buffer.  We'll be generating many SADB_ACQUIRE
237 	 * messages to listening key sockets.  If we simply allocate clusters,
238 	 * sbappendaddr() will raise ENOBUFS due to too little sbspace().
239 	 * sbspace() computes # of actual data bytes AND mbuf region.
240 	 *
241 	 * TODO: SADB_ACQUIRE filters should be implemented.
242 	 */
243 	tlen = len;
244 	m = mprev = NULL;
245 	while (tlen > 0) {
246 		int mlen;
247 		if (tlen == len) {
248 			MGETHDR(n, M_DONTWAIT, MT_DATA);
249 			mlen = MHLEN;
250 		} else {
251 			MGET(n, M_DONTWAIT, MT_DATA);
252 			mlen = MLEN;
253 		}
254 		if (!n) {
255 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
256 			return ENOBUFS;
257 		}
258 		n->m_len = mlen;
259 		if (tlen >= MCLBYTES) {	/*XXX better threshold? */
260 			MCLGET(n, M_DONTWAIT);
261 			if ((n->m_flags & M_EXT) == 0) {
262 				m_free(n);
263 				m_freem(m);
264 				PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
265 				return ENOBUFS;
266 			}
267 			n->m_len = MCLBYTES;
268 		}
269 
270 		if (tlen < n->m_len)
271 			n->m_len = tlen;
272 		n->m_next = NULL;
273 		if (m == NULL)
274 			m = mprev = n;
275 		else {
276 			mprev->m_next = n;
277 			mprev = n;
278 		}
279 		tlen -= n->m_len;
280 		n = NULL;
281 	}
282 	m->m_pkthdr.len = len;
283 	m->m_pkthdr.rcvif = NULL;
284 	m_copyback(m, 0, len, msg);
285 
286 	/* avoid duplicated statistics */
287 	{
288 		uint64_t *ps = PFKEY_STAT_GETREF();
289 		ps[PFKEY_STAT_IN_TOTAL]--;
290 		ps[PFKEY_STAT_IN_BYTES] -= len;
291 		ps[PFKEY_STAT_IN_MSGTYPE + msg->sadb_msg_type]--;
292 		PFKEY_STAT_PUTREF();
293 	}
294 
295 	return key_sendup_mbuf(so, m, target);
296 }
297 
298 /* so can be NULL if target != KEY_SENDUP_ONE */
299 int
300 key_sendup_mbuf(struct socket *so, struct mbuf *m,
301 		int target/*, sbprio */)
302 {
303 	struct mbuf *n;
304 	struct keycb *kp;
305 	int sendup;
306 	struct rawcb *rp;
307 	int error = 0;
308 	int sbprio = 0; /* XXX should be a parameter */
309 
310 	if (m == NULL)
311 		panic("key_sendup_mbuf: NULL pointer was passed");
312 	if (so == NULL && target == KEY_SENDUP_ONE)
313 		panic("key_sendup_mbuf: NULL pointer was passed");
314 
315 	/*
316 	 * RFC 2367 says ACQUIRE and other kernel-generated messages
317 	 * are special. We treat all KEY_SENDUP_REGISTERED messages
318 	 * as special, delivering them to all registered sockets
319 	 * even if the socket is at or above its so->so_rcv.sb_max limits.
320 	 * The only constraint is that the  so_rcv data fall below
321 	 * key_registered_sb_max.
322 	 * Doing that check here avoids reworking every key_sendup_mbuf()
323 	 * in the short term. . The rework will be done after a technical
324 	 * conensus that this approach is appropriate.
325  	 */
326 	if (target == KEY_SENDUP_REGISTERED) {
327 		sbprio = SB_PRIO_BESTEFFORT;
328 	}
329 
330 	{
331 		uint64_t *ps = PFKEY_STAT_GETREF();
332 		ps[PFKEY_STAT_IN_TOTAL]++;
333 		ps[PFKEY_STAT_IN_BYTES] += m->m_pkthdr.len;
334 		PFKEY_STAT_PUTREF();
335 	}
336 	if (m->m_len < sizeof(struct sadb_msg)) {
337 #if 1
338 		m = m_pullup(m, sizeof(struct sadb_msg));
339 		if (m == NULL) {
340 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
341 			return ENOBUFS;
342 		}
343 #else
344 		/* don't bother pulling it up just for stats */
345 #endif
346 	}
347 	if (m->m_len >= sizeof(struct sadb_msg)) {
348 		struct sadb_msg *msg;
349 		msg = mtod(m, struct sadb_msg *);
350 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTYPE + msg->sadb_msg_type);
351 	}
352 
353 	LIST_FOREACH(rp, &rawcb_list, rcb_list)
354 	{
355 		struct socket * kso = rp->rcb_socket;
356 		if (rp->rcb_proto.sp_family != PF_KEY)
357 			continue;
358 		if (rp->rcb_proto.sp_protocol
359 		 && rp->rcb_proto.sp_protocol != PF_KEY_V2) {
360 			continue;
361 		}
362 
363 		kp = (struct keycb *)rp;
364 
365 		/*
366 		 * If you are in promiscuous mode, and when you get broadcasted
367 		 * reply, you'll get two PF_KEY messages.
368 		 * (based on pf_key@inner.net message on 14 Oct 1998)
369 		 */
370 		if (((struct keycb *)rp)->kp_promisc) {
371 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
372 				(void)key_sendup0(rp, n, 1, 0);
373 				n = NULL;
374 			}
375 		}
376 
377 		/* the exact target will be processed later */
378 		if (so && sotorawcb(so) == rp)
379 			continue;
380 
381 		sendup = 0;
382 		switch (target) {
383 		case KEY_SENDUP_ONE:
384 			/* the statement has no effect */
385 			if (so && sotorawcb(so) == rp)
386 				sendup++;
387 			break;
388 		case KEY_SENDUP_ALL:
389 			sendup++;
390 			break;
391 		case KEY_SENDUP_REGISTERED:
392 			if (kp->kp_registered) {
393 				if (kso->so_rcv.sb_cc <= key_registered_sb_max)
394 					sendup++;
395 			  	else
396 			  		printf("keysock: "
397 					       "registered sendup dropped, "
398 					       "sb_cc %ld max %d\n",
399 					       kso->so_rcv.sb_cc,
400 					       key_registered_sb_max);
401 			}
402 			break;
403 		}
404 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTARGET + target);
405 
406 		if (!sendup)
407 			continue;
408 
409 		if ((n = m_copy(m, 0, (int)M_COPYALL)) == NULL) {
410 			m_freem(m);
411 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
412 			return ENOBUFS;
413 		}
414 
415 		if ((error = key_sendup0(rp, n, 0, 0)) != 0) {
416 			m_freem(m);
417 			return error;
418 		}
419 
420 		n = NULL;
421 	}
422 
423 	/* The 'later' time for processing the exact target has arrived */
424 	if (so) {
425 		error = key_sendup0(sotorawcb(so), m, 0, sbprio);
426 		m = NULL;
427 	} else {
428 		error = 0;
429 		m_freem(m);
430 	}
431 	return error;
432 }
433 
434 static int
435 key_attach(struct socket *so, int proto)
436 {
437 	struct keycb *kp;
438 	int s, error;
439 
440 	KASSERT(sotorawcb(so) == NULL);
441 	kp = kmem_zalloc(sizeof(*kp), KM_SLEEP);
442 	kp->kp_raw.rcb_len = sizeof(*kp);
443 	so->so_pcb = kp;
444 
445 	s = splsoftnet();
446 	error = raw_attach(so, proto);
447 	if (error) {
448 		PFKEY_STATINC(PFKEY_STAT_SOCKERR);
449 		kmem_free(kp, sizeof(*kp));
450 		so->so_pcb = NULL;
451 		goto out;
452 	}
453 
454 	kp->kp_promisc = kp->kp_registered = 0;
455 
456 	if (kp->kp_raw.rcb_proto.sp_protocol == PF_KEY) /* XXX: AF_KEY */
457 		key_cb.key_count++;
458 	key_cb.any_count++;
459 	kp->kp_raw.rcb_laddr = &key_src;
460 	kp->kp_raw.rcb_faddr = &key_dst;
461 	soisconnected(so);
462 	so->so_options |= SO_USELOOPBACK;
463 out:
464 	KASSERT(solocked(so));
465 	splx(s);
466 	return error;
467 }
468 
469 static void
470 key_detach(struct socket *so)
471 {
472 	struct keycb *kp = (struct keycb *)sotorawcb(so);
473 	int s;
474 
475 	KASSERT(solocked(so));
476 	KASSERT(kp != NULL);
477 
478 	s = splsoftnet();
479 	if (kp->kp_raw.rcb_proto.sp_protocol == PF_KEY) /* XXX: AF_KEY */
480 		key_cb.key_count--;
481 	key_cb.any_count--;
482 	key_freereg(so);
483 	raw_detach(so);
484 	splx(s);
485 }
486 
487 static int
488 key_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
489 {
490 	return EOPNOTSUPP;
491 }
492 
493 /*
494  * key_usrreq()
495  * derived from net/rtsock.c:route_usrreq()
496  */
497 static int
498 key_usrreq(struct socket *so, int req,struct mbuf *m, struct mbuf *nam,
499     struct mbuf *control, struct lwp *l)
500 {
501 	int s, error = 0;
502 
503 	KASSERT(req != PRU_ATTACH);
504 	KASSERT(req != PRU_DETACH);
505 	KASSERT(req != PRU_CONTROL);
506 
507 	s = splsoftnet();
508 	error = raw_usrreq(so, req, m, nam, control, l);
509 	m = control = NULL;	/* reclaimed in raw_usrreq */
510 	splx(s);
511 
512 	return error;
513 }
514 
515 /*
516  * Definitions of protocols supported in the KEY domain.
517  */
518 
519 DOMAIN_DEFINE(keydomain);
520 
521 PR_WRAP_USRREQS(key)
522 #define	key_attach	key_attach_wrapper
523 #define	key_detach	key_detach_wrapper
524 #define	key_ioctl	key_ioctl_wrapper
525 #define	key_usrreq	key_usrreq_wrapper
526 
527 const struct pr_usrreqs key_usrreqs = {
528 	.pr_attach	= key_attach,
529 	.pr_detach	= key_detach,
530 	.pr_ioctl	= key_ioctl,
531 	.pr_generic	= key_usrreq,
532 };
533 
534 const struct protosw keysw[] = {
535     {
536 	.pr_type = SOCK_RAW,
537 	.pr_domain = &keydomain,
538 	.pr_protocol = PF_KEY_V2,
539 	.pr_flags = PR_ATOMIC|PR_ADDR,
540 	.pr_output = key_output,
541 	.pr_ctlinput = raw_ctlinput,
542 	.pr_usrreqs = &key_usrreqs,
543 	.pr_init = raw_init,
544     }
545 };
546 
547 struct domain keydomain = {
548     .dom_family = PF_KEY,
549     .dom_name = "key",
550     .dom_init = key_init,
551     .dom_protosw = keysw,
552     .dom_protoswNPROTOSW = &keysw[__arraycount(keysw)],
553 };
554