xref: /freebsd/sys/netipsec/keysock.c (revision 303989a2f30ecfadc2b76022da579a61008b2951) 
1 /*	$FreeBSD$	*/
2 /*	$KAME: keysock.c,v 1.25 2001/08/13 20:07:41 itojun Exp $	*/
3 
4 /*-
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "opt_ipsec.h"
34 
35 /* This code has derived from sys/net/rtsock.c on FreeBSD2.2.5 */
36 
37 #include <sys/types.h>
38 #include <sys/param.h>
39 #include <sys/domain.h>
40 #include <sys/errno.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/mbuf.h>
45 #include <sys/mutex.h>
46 #include <sys/protosw.h>
47 #include <sys/signalvar.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/systm.h>
52 
53 #include <net/raw_cb.h>
54 #include <net/route.h>
55 
56 #include <net/pfkeyv2.h>
57 #include <netipsec/key.h>
58 #include <netipsec/keysock.h>
59 #include <netipsec/key_debug.h>
60 
61 #include <machine/stdarg.h>
62 
63 struct key_cb {
64 	int key_count;
65 	int any_count;
66 };
67 static struct key_cb key_cb;
68 
69 static struct sockaddr key_dst = { 2, PF_KEY, };
70 static struct sockaddr key_src = { 2, PF_KEY, };
71 
72 static int key_sendup0 __P((struct rawcb *, struct mbuf *, int));
73 
74 struct pfkeystat pfkeystat;
75 
76 /*
77  * key_output()
78  */
79 int
80 #if __STDC__
81 key_output(struct mbuf *m, ...)
82 #else
83 key_output(m, va_alist)
84 	struct mbuf *m;
85 	va_dcl
86 #endif
87 {
88 	struct sadb_msg *msg;
89 	int len, error = 0;
90 	int s;
91 	struct socket *so;
92 	va_list ap;
93 
94 	va_start(ap, m);
95 	so = va_arg(ap, struct socket *);
96 	va_end(ap);
97 
98 	if (m == 0)
99 		panic("%s: NULL pointer was passed.\n", __func__);
100 
101 	pfkeystat.out_total++;
102 	pfkeystat.out_bytes += m->m_pkthdr.len;
103 
104 	len = m->m_pkthdr.len;
105 	if (len < sizeof(struct sadb_msg)) {
106 		pfkeystat.out_tooshort++;
107 		error = EINVAL;
108 		goto end;
109 	}
110 
111 	if (m->m_len < sizeof(struct sadb_msg)) {
112 		if ((m = m_pullup(m, sizeof(struct sadb_msg))) == 0) {
113 			pfkeystat.out_nomem++;
114 			error = ENOBUFS;
115 			goto end;
116 		}
117 	}
118 
119 	M_ASSERTPKTHDR(m);
120 
121 	KEYDEBUG(KEYDEBUG_KEY_DUMP, kdebug_mbuf(m));
122 
123 	msg = mtod(m, struct sadb_msg *);
124 	pfkeystat.out_msgtype[msg->sadb_msg_type]++;
125 	if (len != PFKEY_UNUNIT64(msg->sadb_msg_len)) {
126 		pfkeystat.out_invlen++;
127 		error = EINVAL;
128 		goto end;
129 	}
130 
131 	/*XXX giant lock*/
132 	s = splnet();
133 	error = key_parse(m, so);
134 	m = NULL;
135 	splx(s);
136 end:
137 	if (m)
138 		m_freem(m);
139 	return error;
140 }
141 
142 /*
143  * send message to the socket.
144  */
145 static int
146 key_sendup0(rp, m, promisc)
147 	struct rawcb *rp;
148 	struct mbuf *m;
149 	int promisc;
150 {
151 	int error;
152 
153 	if (promisc) {
154 		struct sadb_msg *pmsg;
155 
156 		M_PREPEND(m, sizeof(struct sadb_msg), M_DONTWAIT);
157 		if (m && m->m_len < sizeof(struct sadb_msg))
158 			m = m_pullup(m, sizeof(struct sadb_msg));
159 		if (!m) {
160 			pfkeystat.in_nomem++;
161 			m_freem(m);
162 			return ENOBUFS;
163 		}
164 		m->m_pkthdr.len += sizeof(*pmsg);
165 
166 		pmsg = mtod(m, struct sadb_msg *);
167 		bzero(pmsg, sizeof(*pmsg));
168 		pmsg->sadb_msg_version = PF_KEY_V2;
169 		pmsg->sadb_msg_type = SADB_X_PROMISC;
170 		pmsg->sadb_msg_len = PFKEY_UNIT64(m->m_pkthdr.len);
171 		/* pid and seq? */
172 
173 		pfkeystat.in_msgtype[pmsg->sadb_msg_type]++;
174 	}
175 
176 	if (!sbappendaddr(&rp->rcb_socket->so_rcv, (struct sockaddr *)&key_src,
177 	    m, NULL)) {
178 		pfkeystat.in_nomem++;
179 		m_freem(m);
180 		error = ENOBUFS;
181 	} else
182 		error = 0;
183 	sorwakeup(rp->rcb_socket);
184 	return error;
185 }
186 
187 /* XXX this interface should be obsoleted. */
188 int
189 key_sendup(so, msg, len, target)
190 	struct socket *so;
191 	struct sadb_msg *msg;
192 	u_int len;
193 	int target;	/*target of the resulting message*/
194 {
195 	struct mbuf *m, *n, *mprev;
196 	int tlen;
197 
198 	/* sanity check */
199 	if (so == 0 || msg == 0)
200 		panic("%s: NULL pointer was passed.\n", __func__);
201 
202 	KEYDEBUG(KEYDEBUG_KEY_DUMP,
203 		printf("%s: \n", __func__);
204 		kdebug_sadb(msg));
205 
206 	/*
207 	 * we increment statistics here, just in case we have ENOBUFS
208 	 * in this function.
209 	 */
210 	pfkeystat.in_total++;
211 	pfkeystat.in_bytes += len;
212 	pfkeystat.in_msgtype[msg->sadb_msg_type]++;
213 
214 	/*
215 	 * Get mbuf chain whenever possible (not clusters),
216 	 * to save socket buffer.  We'll be generating many SADB_ACQUIRE
217 	 * messages to listening key sockets.  If we simply allocate clusters,
218 	 * sbappendaddr() will raise ENOBUFS due to too little sbspace().
219 	 * sbspace() computes # of actual data bytes AND mbuf region.
220 	 *
221 	 * TODO: SADB_ACQUIRE filters should be implemented.
222 	 */
223 	tlen = len;
224 	m = mprev = NULL;
225 	while (tlen > 0) {
226 		if (tlen == len) {
227 			MGETHDR(n, M_DONTWAIT, MT_DATA);
228 			n->m_len = MHLEN;
229 		} else {
230 			MGET(n, M_DONTWAIT, MT_DATA);
231 			n->m_len = MLEN;
232 		}
233 		if (!n) {
234 			pfkeystat.in_nomem++;
235 			return ENOBUFS;
236 		}
237 		if (tlen >= MCLBYTES) {	/*XXX better threshold? */
238 			MCLGET(n, M_DONTWAIT);
239 			if ((n->m_flags & M_EXT) == 0) {
240 				m_free(n);
241 				m_freem(m);
242 				pfkeystat.in_nomem++;
243 				return ENOBUFS;
244 			}
245 			n->m_len = MCLBYTES;
246 		}
247 
248 		if (tlen < n->m_len)
249 			n->m_len = tlen;
250 		n->m_next = NULL;
251 		if (m == NULL)
252 			m = mprev = n;
253 		else {
254 			mprev->m_next = n;
255 			mprev = n;
256 		}
257 		tlen -= n->m_len;
258 		n = NULL;
259 	}
260 	m->m_pkthdr.len = len;
261 	m->m_pkthdr.rcvif = NULL;
262 	m_copyback(m, 0, len, (caddr_t)msg);
263 
264 	/* avoid duplicated statistics */
265 	pfkeystat.in_total--;
266 	pfkeystat.in_bytes -= len;
267 	pfkeystat.in_msgtype[msg->sadb_msg_type]--;
268 
269 	return key_sendup_mbuf(so, m, target);
270 }
271 
272 /* so can be NULL if target != KEY_SENDUP_ONE */
273 int
274 key_sendup_mbuf(so, m, target)
275 	struct socket *so;
276 	struct mbuf *m;
277 	int target;
278 {
279 	struct mbuf *n;
280 	struct keycb *kp;
281 	int sendup;
282 	struct rawcb *rp;
283 	int error = 0;
284 
285 	if (m == NULL)
286 		panic("key_sendup_mbuf: NULL pointer was passed.\n");
287 	if (so == NULL && target == KEY_SENDUP_ONE)
288 		panic("%s: NULL pointer was passed.\n", __func__);
289 
290 	pfkeystat.in_total++;
291 	pfkeystat.in_bytes += m->m_pkthdr.len;
292 	if (m->m_len < sizeof(struct sadb_msg)) {
293 #if 1
294 		m = m_pullup(m, sizeof(struct sadb_msg));
295 		if (m == NULL) {
296 			pfkeystat.in_nomem++;
297 			return ENOBUFS;
298 		}
299 #else
300 		/* don't bother pulling it up just for stats */
301 #endif
302 	}
303 	if (m->m_len >= sizeof(struct sadb_msg)) {
304 		struct sadb_msg *msg;
305 		msg = mtod(m, struct sadb_msg *);
306 		pfkeystat.in_msgtype[msg->sadb_msg_type]++;
307 	}
308 
309 	LIST_FOREACH(rp, &rawcb_list, list)
310 	{
311 		if (rp->rcb_proto.sp_family != PF_KEY)
312 			continue;
313 		if (rp->rcb_proto.sp_protocol
314 		 && rp->rcb_proto.sp_protocol != PF_KEY_V2) {
315 			continue;
316 		}
317 
318 		kp = (struct keycb *)rp;
319 
320 		/*
321 		 * If you are in promiscuous mode, and when you get broadcasted
322 		 * reply, you'll get two PF_KEY messages.
323 		 * (based on pf_key@inner.net message on 14 Oct 1998)
324 		 */
325 		if (((struct keycb *)rp)->kp_promisc) {
326 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
327 				(void)key_sendup0(rp, n, 1);
328 				n = NULL;
329 			}
330 		}
331 
332 		/* the exact target will be processed later */
333 		if (so && sotorawcb(so) == rp)
334 			continue;
335 
336 		sendup = 0;
337 		switch (target) {
338 		case KEY_SENDUP_ONE:
339 			/* the statement has no effect */
340 			if (so && sotorawcb(so) == rp)
341 				sendup++;
342 			break;
343 		case KEY_SENDUP_ALL:
344 			sendup++;
345 			break;
346 		case KEY_SENDUP_REGISTERED:
347 			if (kp->kp_registered)
348 				sendup++;
349 			break;
350 		}
351 		pfkeystat.in_msgtarget[target]++;
352 
353 		if (!sendup)
354 			continue;
355 
356 		if ((n = m_copy(m, 0, (int)M_COPYALL)) == NULL) {
357 			m_freem(m);
358 			pfkeystat.in_nomem++;
359 			return ENOBUFS;
360 		}
361 
362 		if ((error = key_sendup0(rp, n, 0)) != 0) {
363 			m_freem(m);
364 			return error;
365 		}
366 
367 		n = NULL;
368 	}
369 
370 	if (so) {
371 		error = key_sendup0(sotorawcb(so), m, 0);
372 		m = NULL;
373 	} else {
374 		error = 0;
375 		m_freem(m);
376 	}
377 	return error;
378 }
379 
380 /*
381  * key_abort()
382  * derived from net/rtsock.c:rts_abort()
383  */
384 static int
385 key_abort(struct socket *so)
386 {
387 	int s, error;
388 	s = splnet();
389 	error = raw_usrreqs.pru_abort(so);
390 	splx(s);
391 	return error;
392 }
393 
394 /*
395  * key_attach()
396  * derived from net/rtsock.c:rts_attach()
397  */
398 static int
399 key_attach(struct socket *so, int proto, struct thread *td)
400 {
401 	struct keycb *kp;
402 	int s, error;
403 
404 	if (sotorawcb(so) != 0)
405 		return EISCONN;	/* XXX panic? */
406 	kp = (struct keycb *)malloc(sizeof *kp, M_PCB, M_WAITOK|M_ZERO); /* XXX */
407 	if (kp == 0)
408 		return ENOBUFS;
409 
410 	/*
411 	 * The splnet() is necessary to block protocols from sending
412 	 * error notifications (like RTM_REDIRECT or RTM_LOSING) while
413 	 * this PCB is extant but incompletely initialized.
414 	 * Probably we should try to do more of this work beforehand and
415 	 * eliminate the spl.
416 	 */
417 	s = splnet();
418 	so->so_pcb = (caddr_t)kp;
419 	error = raw_usrreqs.pru_attach(so, proto, td);
420 	kp = (struct keycb *)sotorawcb(so);
421 	if (error) {
422 		free(kp, M_PCB);
423 		so->so_pcb = (caddr_t) 0;
424 		splx(s);
425 		return error;
426 	}
427 
428 	kp->kp_promisc = kp->kp_registered = 0;
429 
430 	if (kp->kp_raw.rcb_proto.sp_protocol == PF_KEY) /* XXX: AF_KEY */
431 		key_cb.key_count++;
432 	key_cb.any_count++;
433 	kp->kp_raw.rcb_laddr = &key_src;
434 	kp->kp_raw.rcb_faddr = &key_dst;
435 	soisconnected(so);
436 	so->so_options |= SO_USELOOPBACK;
437 
438 	splx(s);
439 	return 0;
440 }
441 
442 /*
443  * key_bind()
444  * derived from net/rtsock.c:rts_bind()
445  */
446 static int
447 key_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
448 {
449 	int s, error;
450 	s = splnet();
451 	error = raw_usrreqs.pru_bind(so, nam, td); /* xxx just EINVAL */
452 	splx(s);
453 	return error;
454 }
455 
456 /*
457  * key_connect()
458  * derived from net/rtsock.c:rts_connect()
459  */
460 static int
461 key_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
462 {
463 	int s, error;
464 	s = splnet();
465 	error = raw_usrreqs.pru_connect(so, nam, td); /* XXX just EINVAL */
466 	splx(s);
467 	return error;
468 }
469 
470 /*
471  * key_detach()
472  * derived from net/rtsock.c:rts_detach()
473  */
474 static int
475 key_detach(struct socket *so)
476 {
477 	struct keycb *kp = (struct keycb *)sotorawcb(so);
478 	int s, error;
479 
480 	s = splnet();
481 	if (kp != 0) {
482 		if (kp->kp_raw.rcb_proto.sp_protocol
483 		    == PF_KEY) /* XXX: AF_KEY */
484 			key_cb.key_count--;
485 		key_cb.any_count--;
486 
487 		key_freereg(so);
488 	}
489 	error = raw_usrreqs.pru_detach(so);
490 	splx(s);
491 	return error;
492 }
493 
494 /*
495  * key_disconnect()
496  * derived from net/rtsock.c:key_disconnect()
497  */
498 static int
499 key_disconnect(struct socket *so)
500 {
501 	int s, error;
502 	s = splnet();
503 	error = raw_usrreqs.pru_disconnect(so);
504 	splx(s);
505 	return error;
506 }
507 
508 /*
509  * key_peeraddr()
510  * derived from net/rtsock.c:rts_peeraddr()
511  */
512 static int
513 key_peeraddr(struct socket *so, struct sockaddr **nam)
514 {
515 	int s, error;
516 	s = splnet();
517 	error = raw_usrreqs.pru_peeraddr(so, nam);
518 	splx(s);
519 	return error;
520 }
521 
522 /*
523  * key_send()
524  * derived from net/rtsock.c:rts_send()
525  */
526 static int
527 key_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
528 	 struct mbuf *control, struct thread *td)
529 {
530 	int s, error;
531 	s = splnet();
532 	error = raw_usrreqs.pru_send(so, flags, m, nam, control, td);
533 	splx(s);
534 	return error;
535 }
536 
537 /*
538  * key_shutdown()
539  * derived from net/rtsock.c:rts_shutdown()
540  */
541 static int
542 key_shutdown(struct socket *so)
543 {
544 	int s, error;
545 	s = splnet();
546 	error = raw_usrreqs.pru_shutdown(so);
547 	splx(s);
548 	return error;
549 }
550 
551 /*
552  * key_sockaddr()
553  * derived from net/rtsock.c:rts_sockaddr()
554  */
555 static int
556 key_sockaddr(struct socket *so, struct sockaddr **nam)
557 {
558 	int s, error;
559 	s = splnet();
560 	error = raw_usrreqs.pru_sockaddr(so, nam);
561 	splx(s);
562 	return error;
563 }
564 
565 struct pr_usrreqs key_usrreqs = {
566 	.pru_abort =		key_abort,
567 	.pru_attach =		key_attach,
568 	.pru_bind =		key_bind,
569 	.pru_connect =		key_connect,
570 	.pru_detach =		key_detach,
571 	.pru_disconnect =	key_disconnect,
572 	.pru_peeraddr =		key_peeraddr,
573 	.pru_send =		key_send,
574 	.pru_shutdown =		key_shutdown,
575 	.pru_sockaddr =		key_sockaddr,
576 };
577 
578 /* sysctl */
579 SYSCTL_NODE(_net, PF_KEY, key, CTLFLAG_RW, 0, "Key Family");
580 
581 /*
582  * Definitions of protocols supported in the KEY domain.
583  */
584 
585 extern struct domain keydomain;
586 
587 struct protosw keysw[] = {
588 {
589 	.pr_type =		SOCK_RAW,
590 	.pr_domain =		&keydomain,
591 	.pr_protocol =		PF_KEY_V2,
592 	.pr_flags =		PR_ATOMIC|PR_ADDR,
593 	.pr_output =		(pr_output_t *)key_output,
594 	.pr_ctlinput =		raw_ctlinput,
595 	.pr_init =		raw_init,
596 	.pr_usrreqs =		&key_usrreqs
597 }
598 };
599 
600 static void
601 key_init0(void)
602 {
603 	bzero((caddr_t)&key_cb, sizeof(key_cb));
604 	key_init();
605 }
606 
607 struct domain keydomain = {
608 	.dom_family =		PF_KEY,
609 	.dom_name =		"key",
610 	.dom_init =		key_init0,
611 	.dom_protosw =		keysw,
612 	.dom_protoswNPROTOSW =	&keysw[sizeof(keysw)/sizeof(keysw[0])]
613 };
614 
615 DOMAIN_SET(key);
616