xref: /netbsd-src/sys/netipsec/keysock.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1) 
1 /*	$NetBSD: keysock.c,v 1.70 2019/06/12 22:23:50 christos Exp $	*/
2 /*	$FreeBSD: 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 1.70 2019/06/12 22:23:50 christos Exp $");
36 
37 /* This code has derived from sys/net/rtsock.c on FreeBSD2.2.5 */
38 
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #include <sys/domain.h>
42 #include <sys/errno.h>
43 #include <sys/kernel.h>
44 #include <sys/kmem.h>
45 #include <sys/mbuf.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 #include <sys/cpu.h>
53 #include <sys/syslog.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_private.h>
64 
65 struct key_cb {
66 	int key_count;
67 	int any_count;
68 };
69 static struct key_cb key_cb;
70 
71 static struct sockaddr key_dst = {
72     .sa_len = 2,
73     .sa_family = PF_KEY,
74 };
75 static struct sockaddr key_src = {
76     .sa_len = 2,
77     .sa_family = PF_KEY,
78 };
79 
80 static const struct protosw keysw[];
81 
82 static int key_sendup0(struct rawcb *, struct mbuf *, int, int);
83 
84 int key_registered_sb_max = (2048 * MHLEN); /* XXX arbitrary */
85 
86 static kmutex_t *key_so_mtx;
87 static struct rawcbhead key_rawcb;
88 
89 void
90 key_init_so(void)
91 {
92 
93 	key_so_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
94 }
95 
96 static void
97 key_pr_init(void)
98 {
99 
100 	LIST_INIT(&key_rawcb);
101 }
102 
103 /*
104  * key_output()
105  */
106 static int
107 key_output(struct mbuf *m, struct socket *so)
108 {
109 	struct sadb_msg *msg;
110 	int len, error = 0;
111 	int s;
112 
113 	KASSERT(m != NULL);
114 
115 	{
116 		uint64_t *ps = PFKEY_STAT_GETREF();
117 		ps[PFKEY_STAT_OUT_TOTAL]++;
118 		ps[PFKEY_STAT_OUT_BYTES] += m->m_pkthdr.len;
119 		PFKEY_STAT_PUTREF();
120 	}
121 
122 	len = m->m_pkthdr.len;
123 	if (len < sizeof(struct sadb_msg)) {
124 		PFKEY_STATINC(PFKEY_STAT_OUT_TOOSHORT);
125 		error = EINVAL;
126 		goto end;
127 	}
128 
129 	if (m->m_len < sizeof(struct sadb_msg)) {
130 		if ((m = m_pullup(m, sizeof(struct sadb_msg))) == 0) {
131 			PFKEY_STATINC(PFKEY_STAT_OUT_NOMEM);
132 			error = ENOBUFS;
133 			goto end;
134 		}
135 	}
136 
137 	KASSERT((m->m_flags & M_PKTHDR) != 0);
138 
139 	if (KEYDEBUG_ON(KEYDEBUG_KEY_DUMP))
140 		kdebug_mbuf(__func__, m);
141 
142 	msg = mtod(m, struct sadb_msg *);
143 	PFKEY_STATINC(PFKEY_STAT_OUT_MSGTYPE + msg->sadb_msg_type);
144 	if (len != PFKEY_UNUNIT64(msg->sadb_msg_len)) {
145 		PFKEY_STATINC(PFKEY_STAT_OUT_INVLEN);
146 		error = EINVAL;
147 		goto end;
148 	}
149 
150 	/*XXX giant lock*/
151 	s = splsoftnet();
152 	error = key_parse(m, so);
153 	m = NULL;
154 	splx(s);
155 end:
156 	if (m)
157 		m_freem(m);
158 	return error;
159 }
160 
161 /*
162  * send message to the socket.
163  */
164 static int
165 key_sendup0(
166     struct rawcb *rp,
167     struct mbuf *m,
168     int promisc,
169     int sbprio
170 )
171 {
172 	int error;
173 	int ok;
174 
175 	if (promisc) {
176 		struct sadb_msg *pmsg;
177 
178 		M_PREPEND(m, sizeof(struct sadb_msg), M_DONTWAIT);
179 		if (m && m->m_len < sizeof(struct sadb_msg))
180 			m = m_pullup(m, sizeof(struct sadb_msg));
181 		if (!m) {
182 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
183 			return ENOBUFS;
184 		}
185 		m->m_pkthdr.len += sizeof(*pmsg);
186 
187 		pmsg = mtod(m, struct sadb_msg *);
188 		memset(pmsg, 0, sizeof(*pmsg));
189 		pmsg->sadb_msg_version = PF_KEY_V2;
190 		pmsg->sadb_msg_type = SADB_X_PROMISC;
191 		pmsg->sadb_msg_len = PFKEY_UNIT64(m->m_pkthdr.len);
192 		/* pid and seq? */
193 
194 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTYPE + pmsg->sadb_msg_type);
195 	}
196 
197 	if (sbprio == 0)
198 		ok = sbappendaddr(&rp->rcb_socket->so_rcv,
199 			       (struct sockaddr *)&key_src, m, NULL);
200 	else
201 		ok = sbappendaddrchain(&rp->rcb_socket->so_rcv,
202 			       (struct sockaddr *)&key_src, m, sbprio);
203 
204 	if (!ok) {
205 		log(LOG_WARNING,
206 		    "%s: couldn't send PF_KEY message to the socket\n",
207 		    __func__);
208 		PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
209 		m_freem(m);
210 		/* Don't call soroverflow because we're returning this
211 		 * error directly to the sender. */
212 		rp->rcb_socket->so_rcv.sb_overflowed++;
213 		error = ENOBUFS;
214 	} else {
215 		sorwakeup(rp->rcb_socket);
216 		error = 0;
217 	}
218 	return error;
219 }
220 
221 /* so can be NULL if target != KEY_SENDUP_ONE */
222 static int
223 _key_sendup_mbuf(struct socket *so, struct mbuf *m,
224 		int target/*, sbprio */)
225 {
226 	struct mbuf *n;
227 	struct keycb *kp;
228 	int sendup;
229 	struct rawcb *rp;
230 	int error = 0;
231 	int sbprio = 0; /* XXX should be a parameter */
232 
233 	KASSERT(m != NULL);
234 	KASSERT(so != NULL || target != KEY_SENDUP_ONE);
235 
236 	/*
237 	 * RFC 2367 says ACQUIRE and other kernel-generated messages
238 	 * are special. We treat all KEY_SENDUP_REGISTERED messages
239 	 * as special, delivering them to all registered sockets
240 	 * even if the socket is at or above its so->so_rcv.sb_max limits.
241 	 * The only constraint is that the  so_rcv data fall below
242 	 * key_registered_sb_max.
243 	 * Doing that check here avoids reworking every key_sendup_mbuf()
244 	 * in the short term. . The rework will be done after a technical
245 	 * conensus that this approach is appropriate.
246  	 */
247 	if (target == KEY_SENDUP_REGISTERED) {
248 		sbprio = SB_PRIO_BESTEFFORT;
249 	}
250 
251 	{
252 		uint64_t *ps = PFKEY_STAT_GETREF();
253 		ps[PFKEY_STAT_IN_TOTAL]++;
254 		ps[PFKEY_STAT_IN_BYTES] += m->m_pkthdr.len;
255 		PFKEY_STAT_PUTREF();
256 	}
257 	if (m->m_len < sizeof(struct sadb_msg)) {
258 #if 1
259 		m = m_pullup(m, sizeof(struct sadb_msg));
260 		if (m == NULL) {
261 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
262 			return ENOBUFS;
263 		}
264 #else
265 		/* don't bother pulling it up just for stats */
266 #endif
267 	}
268 	if (m->m_len >= sizeof(struct sadb_msg)) {
269 		struct sadb_msg *msg;
270 		msg = mtod(m, struct sadb_msg *);
271 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTYPE + msg->sadb_msg_type);
272 	}
273 
274 	LIST_FOREACH(rp, &key_rawcb, rcb_list)
275 	{
276 		struct socket * kso = rp->rcb_socket;
277 		if (rp->rcb_proto.sp_family != PF_KEY)
278 			continue;
279 		if (rp->rcb_proto.sp_protocol
280 		 && rp->rcb_proto.sp_protocol != PF_KEY_V2) {
281 			continue;
282 		}
283 
284 		kp = (struct keycb *)rp;
285 
286 		/*
287 		 * If you are in promiscuous mode, and when you get broadcasted
288 		 * reply, you'll get two PF_KEY messages.
289 		 * (based on pf_key@inner.net message on 14 Oct 1998)
290 		 */
291 		if (((struct keycb *)rp)->kp_promisc) {
292 			if ((n = m_copym(m, 0, (int)M_COPYALL, M_DONTWAIT)) != NULL) {
293 				(void)key_sendup0(rp, n, 1, 0);
294 				n = NULL;
295 			}
296 		}
297 
298 		/* the exact target will be processed later */
299 		if (so && sotorawcb(so) == rp)
300 			continue;
301 
302 		sendup = 0;
303 		switch (target) {
304 		case KEY_SENDUP_ONE:
305 			/* the statement has no effect */
306 			if (so && sotorawcb(so) == rp)
307 				sendup++;
308 			break;
309 		case KEY_SENDUP_ALL:
310 			sendup++;
311 			break;
312 		case KEY_SENDUP_REGISTERED:
313 			if (kp->kp_registered) {
314 				if (kso->so_rcv.sb_cc <= key_registered_sb_max)
315 					sendup++;
316 			  	else
317 			  		printf("keysock: "
318 					       "registered sendup dropped, "
319 					       "sb_cc %ld max %d\n",
320 					       kso->so_rcv.sb_cc,
321 					       key_registered_sb_max);
322 			}
323 			break;
324 		}
325 		PFKEY_STATINC(PFKEY_STAT_IN_MSGTARGET + target);
326 
327 		if (!sendup)
328 			continue;
329 
330 		if ((n = m_copym(m, 0, (int)M_COPYALL, M_DONTWAIT)) == NULL) {
331 			m_freem(m);
332 			PFKEY_STATINC(PFKEY_STAT_IN_NOMEM);
333 			return ENOBUFS;
334 		}
335 
336 		if ((error = key_sendup0(rp, n, 0, 0)) != 0) {
337 			m_freem(m);
338 			return error;
339 		}
340 
341 		n = NULL;
342 	}
343 
344 	/* The 'later' time for processing the exact target has arrived */
345 	if (so) {
346 		error = key_sendup0(sotorawcb(so), m, 0, sbprio);
347 		m = NULL;
348 	} else {
349 		error = 0;
350 		m_freem(m);
351 	}
352 	return error;
353 }
354 
355 int
356 key_sendup_mbuf(struct socket *so, struct mbuf *m,
357 		int target/*, sbprio */)
358 {
359 	int error;
360 
361 	if (so == NULL)
362 		mutex_enter(key_so_mtx);
363 	else
364 		KASSERT(solocked(so));
365 
366 	error = _key_sendup_mbuf(so, m, target);
367 
368 	if (so == NULL)
369 		mutex_exit(key_so_mtx);
370 	return error;
371 }
372 
373 static int
374 key_attach(struct socket *so, int proto)
375 {
376 	struct keycb *kp;
377 	int s, error;
378 
379 	KASSERT(sotorawcb(so) == NULL);
380 	kp = kmem_zalloc(sizeof(*kp), KM_SLEEP);
381 	kp->kp_raw.rcb_len = sizeof(*kp);
382 	so->so_pcb = kp;
383 
384 	s = splsoftnet();
385 
386 	if (so->so_lock != key_so_mtx) {
387 		KASSERT(so->so_lock == NULL);
388 		mutex_obj_hold(key_so_mtx);
389 		so->so_lock = key_so_mtx;
390 		solock(so);
391 	}
392 
393 	error = raw_attach(so, proto, &key_rawcb);
394 	if (error) {
395 		PFKEY_STATINC(PFKEY_STAT_SOCKERR);
396 		kmem_free(kp, sizeof(*kp));
397 		so->so_pcb = NULL;
398 		goto out;
399 	}
400 
401 	kp->kp_promisc = kp->kp_registered = 0;
402 
403 	if (kp->kp_raw.rcb_proto.sp_protocol == PF_KEY) /* XXX: AF_KEY */
404 		key_cb.key_count++;
405 	key_cb.any_count++;
406 	kp->kp_raw.rcb_laddr = &key_src;
407 	kp->kp_raw.rcb_faddr = &key_dst;
408 	soisconnected(so);
409 	so->so_options |= SO_USELOOPBACK;
410 out:
411 	KASSERT(solocked(so));
412 	splx(s);
413 	return error;
414 }
415 
416 static void
417 key_detach(struct socket *so)
418 {
419 	struct keycb *kp = (struct keycb *)sotorawcb(so);
420 	int s;
421 
422 	KASSERT(!cpu_softintr_p());
423 	KASSERT(solocked(so));
424 	KASSERT(kp != NULL);
425 
426 	s = splsoftnet();
427 	if (kp->kp_raw.rcb_proto.sp_protocol == PF_KEY) /* XXX: AF_KEY */
428 		key_cb.key_count--;
429 	key_cb.any_count--;
430 	key_freereg(so);
431 	raw_detach(so);
432 	splx(s);
433 }
434 
435 static int
436 key_accept(struct socket *so, struct sockaddr *nam)
437 {
438 	KASSERT(solocked(so));
439 
440 	panic("%s: unsupported", __func__);
441 
442 	return EOPNOTSUPP;
443 }
444 
445 static int
446 key_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
447 {
448 	KASSERT(solocked(so));
449 
450 	return EOPNOTSUPP;
451 }
452 
453 static int
454 key_listen(struct socket *so, struct lwp *l)
455 {
456 	KASSERT(solocked(so));
457 
458 	return EOPNOTSUPP;
459 }
460 
461 static int
462 key_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
463 {
464 	KASSERT(solocked(so));
465 
466 	return EOPNOTSUPP;
467 }
468 
469 static int
470 key_connect2(struct socket *so, struct socket *so2)
471 {
472 	KASSERT(solocked(so));
473 
474 	return EOPNOTSUPP;
475 }
476 
477 static int
478 key_disconnect(struct socket *so)
479 {
480 	struct rawcb *rp = sotorawcb(so);
481 	int s;
482 
483 	KASSERT(solocked(so));
484 	KASSERT(rp != NULL);
485 
486 	s = splsoftnet();
487 	soisdisconnected(so);
488 	raw_disconnect(rp);
489 	splx(s);
490 
491 	return 0;
492 }
493 
494 static int
495 key_shutdown(struct socket *so)
496 {
497 	int s;
498 
499 	KASSERT(solocked(so));
500 
501 	/*
502 	 * Mark the connection as being incapable of further input.
503 	 */
504 	s = splsoftnet();
505 	socantsendmore(so);
506 	splx(s);
507 
508 	return 0;
509 }
510 
511 static int
512 key_abort(struct socket *so)
513 {
514 	KASSERT(solocked(so));
515 
516 	panic("%s: unsupported", __func__);
517 
518 	return EOPNOTSUPP;
519 }
520 
521 static int
522 key_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
523 {
524 	return EOPNOTSUPP;
525 }
526 
527 static int
528 key_stat(struct socket *so, struct stat *ub)
529 {
530 	KASSERT(solocked(so));
531 
532 	return 0;
533 }
534 
535 static int
536 key_peeraddr(struct socket *so, struct sockaddr *nam)
537 {
538 	struct rawcb *rp = sotorawcb(so);
539 
540 	KASSERT(solocked(so));
541 	KASSERT(rp != NULL);
542 	KASSERT(nam != NULL);
543 
544 	if (rp->rcb_faddr == NULL)
545 		return ENOTCONN;
546 
547 	raw_setpeeraddr(rp, nam);
548 	return 0;
549 }
550 
551 static int
552 key_sockaddr(struct socket *so, struct sockaddr *nam)
553 {
554 	struct rawcb *rp = sotorawcb(so);
555 
556 	KASSERT(solocked(so));
557 	KASSERT(rp != NULL);
558 	KASSERT(nam != NULL);
559 
560 	if (rp->rcb_faddr == NULL)
561 		return ENOTCONN;
562 
563 	raw_setsockaddr(rp, nam);
564 	return 0;
565 }
566 
567 static int
568 key_rcvd(struct socket *so, int flags, struct lwp *l)
569 {
570 	KASSERT(solocked(so));
571 
572 	return EOPNOTSUPP;
573 }
574 
575 static int
576 key_recvoob(struct socket *so, struct mbuf *m, int flags)
577 {
578 	KASSERT(solocked(so));
579 
580 	return EOPNOTSUPP;
581 }
582 
583 static int
584 key_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
585     struct mbuf *control, struct lwp *l)
586 {
587 	int error = 0;
588 	int s;
589 
590 	KASSERT(solocked(so));
591 	KASSERT(so->so_proto == &keysw[0]);
592 
593 	s = splsoftnet();
594 	error = raw_send(so, m, nam, control, l, &key_output);
595 	splx(s);
596 
597 	return error;
598 }
599 
600 static int
601 key_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
602 {
603 	KASSERT(solocked(so));
604 
605 	m_freem(m);
606 	m_freem(control);
607 
608 	return EOPNOTSUPP;
609 }
610 
611 static int
612 key_purgeif(struct socket *so, struct ifnet *ifa)
613 {
614 
615 	panic("%s: unsupported", __func__);
616 
617 	return EOPNOTSUPP;
618 }
619 
620 /*
621  * Definitions of protocols supported in the KEY domain.
622  */
623 
624 DOMAIN_DEFINE(keydomain);
625 
626 PR_WRAP_USRREQS(key)
627 #define	key_attach	key_attach_wrapper
628 #define	key_detach	key_detach_wrapper
629 #define	key_accept	key_accept_wrapper
630 #define	key_bind	key_bind_wrapper
631 #define	key_listen	key_listen_wrapper
632 #define	key_connect	key_connect_wrapper
633 #define	key_connect2	key_connect2_wrapper
634 #define	key_disconnect	key_disconnect_wrapper
635 #define	key_shutdown	key_shutdown_wrapper
636 #define	key_abort	key_abort_wrapper
637 #define	key_ioctl	key_ioctl_wrapper
638 #define	key_stat	key_stat_wrapper
639 #define	key_peeraddr	key_peeraddr_wrapper
640 #define	key_sockaddr	key_sockaddr_wrapper
641 #define	key_rcvd	key_rcvd_wrapper
642 #define	key_recvoob	key_recvoob_wrapper
643 #define	key_send	key_send_wrapper
644 #define	key_sendoob	key_sendoob_wrapper
645 #define	key_purgeif	key_purgeif_wrapper
646 
647 static const struct pr_usrreqs key_usrreqs = {
648 	.pr_attach	= key_attach,
649 	.pr_detach	= key_detach,
650 	.pr_accept	= key_accept,
651 	.pr_bind	= key_bind,
652 	.pr_listen	= key_listen,
653 	.pr_connect	= key_connect,
654 	.pr_connect2	= key_connect2,
655 	.pr_disconnect	= key_disconnect,
656 	.pr_shutdown	= key_shutdown,
657 	.pr_abort	= key_abort,
658 	.pr_ioctl	= key_ioctl,
659 	.pr_stat	= key_stat,
660 	.pr_peeraddr	= key_peeraddr,
661 	.pr_sockaddr	= key_sockaddr,
662 	.pr_rcvd	= key_rcvd,
663 	.pr_recvoob	= key_recvoob,
664 	.pr_send	= key_send,
665 	.pr_sendoob	= key_sendoob,
666 	.pr_purgeif	= key_purgeif,
667 };
668 
669 static const struct protosw keysw[] = {
670     {
671 	.pr_type = SOCK_RAW,
672 	.pr_domain = &keydomain,
673 	.pr_protocol = PF_KEY_V2,
674 	.pr_flags = PR_ATOMIC|PR_ADDR,
675 	.pr_ctlinput = raw_ctlinput,
676 	.pr_usrreqs = &key_usrreqs,
677 	.pr_init = key_pr_init,
678     }
679 };
680 
681 struct domain keydomain = {
682     .dom_family = PF_KEY,
683     .dom_name = "key",
684     .dom_init = key_init,
685     .dom_protosw = keysw,
686     .dom_protoswNPROTOSW = &keysw[__arraycount(keysw)],
687 };
688