xref: /freebsd/sys/net/if_ipsec.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 2016 Yandex LLC
3  * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
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 ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/fnv_hash.h>
38 #include <sys/jail.h>
39 #include <sys/lock.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/module.h>
43 #include <sys/rmlock.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/sx.h>
47 #include <sys/errno.h>
48 #include <sys/sysctl.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/conf.h>
52 
53 #include <net/if.h>
54 #include <net/if_var.h>
55 #include <net/if_clone.h>
56 #include <net/if_types.h>
57 #include <net/bpf.h>
58 #include <net/route.h>
59 #include <net/vnet.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
63 #include <netinet/ip.h>
64 
65 #include <netinet/ip6.h>
66 #include <netinet6/in6_var.h>
67 #include <netinet6/scope6_var.h>
68 
69 #include <netipsec/ipsec.h>
70 #ifdef INET6
71 #include <netipsec/ipsec6.h>
72 #endif
73 
74 #include <net/if_ipsec.h>
75 #include <netipsec/key.h>
76 
77 #include <security/mac/mac_framework.h>
78 
79 static MALLOC_DEFINE(M_IPSEC, "ipsec", "IPsec Virtual Tunnel Interface");
80 static const char ipsecname[] = "ipsec";
81 
82 #if defined(INET) && defined(INET6)
83 #define	IPSEC_SPCOUNT		4
84 #else
85 #define	IPSEC_SPCOUNT		2
86 #endif
87 
88 struct ipsec_softc {
89 	struct ifnet		*ifp;
90 
91 	struct rmlock		lock;
92 	struct secpolicy	*sp[IPSEC_SPCOUNT];
93 
94 	uint32_t		reqid;
95 	u_int			family;
96 	u_int			fibnum;
97 	LIST_ENTRY(ipsec_softc)	chain;
98 	LIST_ENTRY(ipsec_softc) hash;
99 };
100 
101 #define	IPSEC_LOCK_INIT(sc)	rm_init(&(sc)->lock, "if_ipsec softc")
102 #define	IPSEC_LOCK_DESTROY(sc)	rm_destroy(&(sc)->lock)
103 #define	IPSEC_RLOCK_TRACKER	struct rm_priotracker ipsec_tracker
104 #define	IPSEC_RLOCK(sc)		rm_rlock(&(sc)->lock, &ipsec_tracker)
105 #define	IPSEC_RUNLOCK(sc)	rm_runlock(&(sc)->lock, &ipsec_tracker)
106 #define	IPSEC_RLOCK_ASSERT(sc)	rm_assert(&(sc)->lock, RA_RLOCKED)
107 #define	IPSEC_WLOCK(sc)		rm_wlock(&(sc)->lock)
108 #define	IPSEC_WUNLOCK(sc)	rm_wunlock(&(sc)->lock)
109 #define	IPSEC_WLOCK_ASSERT(sc)	rm_assert(&(sc)->lock, RA_WLOCKED)
110 
111 static struct rmlock ipsec_sc_lock;
112 RM_SYSINIT(ipsec_sc_lock, &ipsec_sc_lock, "if_ipsec softc list");
113 
114 #define	IPSEC_SC_RLOCK_TRACKER	struct rm_priotracker ipsec_sc_tracker
115 #define	IPSEC_SC_RLOCK()	rm_rlock(&ipsec_sc_lock, &ipsec_sc_tracker)
116 #define	IPSEC_SC_RUNLOCK()	rm_runlock(&ipsec_sc_lock, &ipsec_sc_tracker)
117 #define	IPSEC_SC_RLOCK_ASSERT()	rm_assert(&ipsec_sc_lock, RA_RLOCKED)
118 #define	IPSEC_SC_WLOCK()	rm_wlock(&ipsec_sc_lock)
119 #define	IPSEC_SC_WUNLOCK()	rm_wunlock(&ipsec_sc_lock)
120 #define	IPSEC_SC_WLOCK_ASSERT()	rm_assert(&ipsec_sc_lock, RA_WLOCKED)
121 
122 LIST_HEAD(ipsec_iflist, ipsec_softc);
123 static VNET_DEFINE(struct ipsec_iflist, ipsec_sc_list);
124 static VNET_DEFINE(struct ipsec_iflist *, ipsec_sc_htbl);
125 static VNET_DEFINE(u_long, ipsec_sc_hmask);
126 #define	V_ipsec_sc_list		VNET(ipsec_sc_list)
127 #define	V_ipsec_sc_htbl		VNET(ipsec_sc_htbl)
128 #define	V_ipsec_sc_hmask	VNET(ipsec_sc_hmask)
129 
130 static uint32_t
131 ipsec_hash(uint32_t id)
132 {
133 
134 	return (fnv_32_buf(&id, sizeof(id), FNV1_32_INIT));
135 }
136 
137 #define	SCHASH_NHASH_LOG2	5
138 #define	SCHASH_NHASH		(1 << SCHASH_NHASH_LOG2)
139 #define	SCHASH_HASHVAL(id)	(ipsec_hash((id)) & V_ipsec_sc_hmask)
140 #define	SCHASH_HASH(id)		&V_ipsec_sc_htbl[SCHASH_HASHVAL(id)]
141 
142 /*
143  * ipsec_ioctl_sx protects from concurrent ioctls.
144  */
145 static struct sx ipsec_ioctl_sx;
146 SX_SYSINIT(ipsec_ioctl_sx, &ipsec_ioctl_sx, "ipsec_ioctl");
147 
148 static int	ipsec_init_reqid(struct ipsec_softc *);
149 static int	ipsec_set_tunnel(struct ipsec_softc *, struct sockaddr *,
150     struct sockaddr *, uint32_t);
151 static void	ipsec_delete_tunnel(struct ifnet *, int);
152 
153 static int	ipsec_set_addresses(struct ifnet *, struct sockaddr *,
154     struct sockaddr *);
155 static int	ipsec_set_reqid(struct ifnet *, uint32_t);
156 
157 static int	ipsec_ioctl(struct ifnet *, u_long, caddr_t);
158 static int	ipsec_transmit(struct ifnet *, struct mbuf *);
159 static int	ipsec_output(struct ifnet *, struct mbuf *,
160     const struct sockaddr *, struct route *);
161 static void	ipsec_qflush(struct ifnet *);
162 static int	ipsec_clone_create(struct if_clone *, int, caddr_t);
163 static void	ipsec_clone_destroy(struct ifnet *);
164 
165 static VNET_DEFINE(struct if_clone *, ipsec_cloner);
166 #define	V_ipsec_cloner		VNET(ipsec_cloner)
167 
168 static int
169 ipsec_clone_create(struct if_clone *ifc, int unit, caddr_t params)
170 {
171 	struct ipsec_softc *sc;
172 	struct ifnet *ifp;
173 
174 	sc = malloc(sizeof(*sc), M_IPSEC, M_WAITOK | M_ZERO);
175 	sc->fibnum = curthread->td_proc->p_fibnum;
176 	sc->ifp = ifp = if_alloc(IFT_TUNNEL);
177 	IPSEC_LOCK_INIT(sc);
178 	ifp->if_softc = sc;
179 	if_initname(ifp, ipsecname, unit);
180 
181 	ifp->if_addrlen = 0;
182 	ifp->if_mtu = IPSEC_MTU;
183 	ifp->if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
184 	ifp->if_ioctl  = ipsec_ioctl;
185 	ifp->if_transmit  = ipsec_transmit;
186 	ifp->if_qflush  = ipsec_qflush;
187 	ifp->if_output = ipsec_output;
188 	if_attach(ifp);
189 	bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
190 
191 	IPSEC_SC_WLOCK();
192 	LIST_INSERT_HEAD(&V_ipsec_sc_list, sc, chain);
193 	IPSEC_SC_WUNLOCK();
194 	return (0);
195 }
196 
197 static void
198 ipsec_clone_destroy(struct ifnet *ifp)
199 {
200 	struct ipsec_softc *sc;
201 
202 	sx_xlock(&ipsec_ioctl_sx);
203 	sc = ifp->if_softc;
204 
205 	IPSEC_SC_WLOCK();
206 	ipsec_delete_tunnel(ifp, 1);
207 	LIST_REMOVE(sc, chain);
208 	IPSEC_SC_WUNLOCK();
209 
210 	bpfdetach(ifp);
211 	if_detach(ifp);
212 	ifp->if_softc = NULL;
213 	sx_xunlock(&ipsec_ioctl_sx);
214 
215 	if_free(ifp);
216 	IPSEC_LOCK_DESTROY(sc);
217 	free(sc, M_IPSEC);
218 }
219 
220 static void
221 vnet_ipsec_init(const void *unused __unused)
222 {
223 
224 	LIST_INIT(&V_ipsec_sc_list);
225 	V_ipsec_sc_htbl = hashinit(SCHASH_NHASH, M_IPSEC, &V_ipsec_sc_hmask);
226 	V_ipsec_cloner = if_clone_simple(ipsecname, ipsec_clone_create,
227 	    ipsec_clone_destroy, 0);
228 }
229 VNET_SYSINIT(vnet_ipsec_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
230     vnet_ipsec_init, NULL);
231 
232 static void
233 vnet_ipsec_uninit(const void *unused __unused)
234 {
235 
236 	if_clone_detach(V_ipsec_cloner);
237 	hashdestroy(V_ipsec_sc_htbl, M_IPSEC, V_ipsec_sc_hmask);
238 }
239 VNET_SYSUNINIT(vnet_ipsec_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
240     vnet_ipsec_uninit, NULL);
241 
242 static struct secpolicy *
243 ipsec_getpolicy(struct ipsec_softc *sc, int dir, sa_family_t af)
244 {
245 
246 	switch (af) {
247 #ifdef INET
248 	case AF_INET:
249 		return (sc->sp[(dir == IPSEC_DIR_INBOUND ? 0: 1)]);
250 #endif
251 #ifdef INET6
252 	case AF_INET6:
253 		return (sc->sp[(dir == IPSEC_DIR_INBOUND ? 0: 1)
254 #ifdef INET
255 			+ 2
256 #endif
257 		]);
258 #endif
259 	}
260 	return (NULL);
261 }
262 
263 static struct secasindex *
264 ipsec_getsaidx(struct ipsec_softc *sc, int dir, sa_family_t af)
265 {
266 	struct secpolicy *sp;
267 
268 	sp = ipsec_getpolicy(sc, dir, af);
269 	if (sp == NULL)
270 		return (NULL);
271 	return (&sp->req[0]->saidx);
272 }
273 
274 static int
275 ipsec_transmit(struct ifnet *ifp, struct mbuf *m)
276 {
277 	IPSEC_RLOCK_TRACKER;
278 	struct ipsec_softc *sc;
279 	struct secpolicy *sp;
280 	struct ip *ip;
281 	uint32_t af;
282 	int error;
283 
284 #ifdef MAC
285 	error = mac_ifnet_check_transmit(ifp, m);
286 	if (error) {
287 		m_freem(m);
288 		goto err;
289 	}
290 #endif
291 	error = ENETDOWN;
292 	sc = ifp->if_softc;
293 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
294 	    (ifp->if_flags & IFF_MONITOR) != 0 ||
295 	    (ifp->if_flags & IFF_UP) == 0) {
296 		m_freem(m);
297 		goto err;
298 	}
299 
300 	/* Determine address family to correctly handle packet in BPF */
301 	ip = mtod(m, struct ip *);
302 	switch (ip->ip_v) {
303 #ifdef INET
304 	case IPVERSION:
305 		af = AF_INET;
306 		break;
307 #endif
308 #ifdef INET6
309 	case (IPV6_VERSION >> 4):
310 		af = AF_INET6;
311 		break;
312 #endif
313 	default:
314 		error = EAFNOSUPPORT;
315 		m_freem(m);
316 		goto err;
317 	}
318 
319 	/*
320 	 * Loop prevention.
321 	 * XXX: for now just check presence of IPSEC_OUT_DONE mbuf tag.
322 	 *      We can read full chain and compare destination address,
323 	 *      proto and mode from xform_history with values from softc.
324 	 */
325 	if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) {
326 		m_freem(m);
327 		goto err;
328 	}
329 
330 	IPSEC_RLOCK(sc);
331 	if (sc->family == 0) {
332 		IPSEC_RUNLOCK(sc);
333 		m_freem(m);
334 		goto err;
335 	}
336 	sp = ipsec_getpolicy(sc, IPSEC_DIR_OUTBOUND, af);
337 	key_addref(sp);
338 	M_SETFIB(m, sc->fibnum);
339 	IPSEC_RUNLOCK(sc);
340 
341 	BPF_MTAP2(ifp, &af, sizeof(af), m);
342 	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
343 	if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
344 
345 	switch (af) {
346 #ifdef INET
347 	case AF_INET:
348 		error = ipsec4_process_packet(m, sp, NULL);
349 		break;
350 #endif
351 #ifdef INET6
352 	case AF_INET6:
353 		error = ipsec6_process_packet(m, sp, NULL);
354 		break;
355 #endif
356 	default:
357 		panic("%s: unknown address family\n", __func__);
358 	}
359 err:
360 	if (error != 0)
361 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
362 	return (error);
363 }
364 
365 static void
366 ipsec_qflush(struct ifnet *ifp __unused)
367 {
368 
369 }
370 
371 static int
372 ipsec_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
373 	struct route *ro)
374 {
375 
376 	return (ifp->if_transmit(ifp, m));
377 }
378 
379 int
380 ipsec_if_input(struct mbuf *m, struct secasvar *sav, uint32_t af)
381 {
382 	IPSEC_SC_RLOCK_TRACKER;
383 	struct secasindex *saidx;
384 	struct ipsec_softc *sc;
385 	struct ifnet *ifp;
386 
387 	if (sav->state != SADB_SASTATE_MATURE &&
388 	    sav->state != SADB_SASTATE_DYING) {
389 		m_freem(m);
390 		return (ENETDOWN);
391 	}
392 
393 	if (sav->sah->saidx.mode != IPSEC_MODE_TUNNEL ||
394 	    sav->sah->saidx.proto != IPPROTO_ESP)
395 		return (0);
396 
397 	IPSEC_SC_RLOCK();
398 	/*
399 	 * We only acquire SC_RLOCK() while we are doing search in
400 	 * ipsec_sc_htbl. It is safe, because removing softc or changing
401 	 * of reqid/addresses requires removing from hash table.
402 	 */
403 	LIST_FOREACH(sc, SCHASH_HASH(sav->sah->saidx.reqid), hash) {
404 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_INBOUND,
405 		    sav->sah->saidx.src.sa.sa_family);
406 		/* SA's reqid should match reqid in SP */
407 		if (saidx == NULL ||
408 		    sav->sah->saidx.reqid != saidx->reqid)
409 			continue;
410 		/* SAH's addresses should match tunnel endpoints. */
411 		if (key_sockaddrcmp(&sav->sah->saidx.dst.sa,
412 		    &saidx->dst.sa, 0) != 0)
413 			continue;
414 		if (key_sockaddrcmp(&sav->sah->saidx.src.sa,
415 		    &saidx->src.sa, 0) == 0)
416 			break;
417 	}
418 	if (sc == NULL) {
419 		IPSEC_SC_RUNLOCK();
420 		/* Tunnel was not found. Nothing to do. */
421 		return (0);
422 	}
423 	ifp = sc->ifp;
424 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
425 	    (ifp->if_flags & IFF_UP) == 0) {
426 		IPSEC_SC_RUNLOCK();
427 		m_freem(m);
428 		return (ENETDOWN);
429 	}
430 	/*
431 	 * We found matching and working tunnel.
432 	 * Set its ifnet as receiving interface.
433 	 */
434 	m->m_pkthdr.rcvif = ifp;
435 	IPSEC_SC_RUNLOCK();
436 
437 	/* m_clrprotoflags(m); */
438 	M_SETFIB(m, ifp->if_fib);
439 	BPF_MTAP2(ifp, &af, sizeof(af), m);
440 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
441 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
442 	if ((ifp->if_flags & IFF_MONITOR) != 0) {
443 		m_freem(m);
444 		return (ENETDOWN);
445 	}
446 	return (0);
447 }
448 
449 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
450 int
451 ipsec_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
452 {
453 	IPSEC_RLOCK_TRACKER;
454 	struct ifreq *ifr = (struct ifreq*)data;
455 	struct sockaddr *dst, *src;
456 	struct ipsec_softc *sc;
457 	struct secasindex *saidx;
458 #ifdef INET
459 	struct sockaddr_in *sin = NULL;
460 #endif
461 #ifdef INET6
462 	struct sockaddr_in6 *sin6 = NULL;
463 #endif
464 	uint32_t reqid;
465 	int error;
466 
467 	switch (cmd) {
468 	case SIOCSIFADDR:
469 		ifp->if_flags |= IFF_UP;
470 	case SIOCADDMULTI:
471 	case SIOCDELMULTI:
472 	case SIOCGIFMTU:
473 	case SIOCSIFFLAGS:
474 		return (0);
475 	case SIOCSIFMTU:
476 		if (ifr->ifr_mtu < IPSEC_MTU_MIN ||
477 		    ifr->ifr_mtu > IPSEC_MTU_MAX)
478 			return (EINVAL);
479 		else
480 			ifp->if_mtu = ifr->ifr_mtu;
481 		return (0);
482 	}
483 	sx_xlock(&ipsec_ioctl_sx);
484 	sc = ifp->if_softc;
485 	/* Check that softc is still here */
486 	if (sc == NULL) {
487 		error = ENXIO;
488 		goto bad;
489 	}
490 	error = 0;
491 	switch (cmd) {
492 	case SIOCSIFPHYADDR:
493 #ifdef INET6
494 	case SIOCSIFPHYADDR_IN6:
495 #endif
496 		error = EINVAL;
497 		switch (cmd) {
498 #ifdef INET
499 		case SIOCSIFPHYADDR:
500 			src = (struct sockaddr *)
501 				&(((struct in_aliasreq *)data)->ifra_addr);
502 			dst = (struct sockaddr *)
503 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
504 			break;
505 #endif
506 #ifdef INET6
507 		case SIOCSIFPHYADDR_IN6:
508 			src = (struct sockaddr *)
509 				&(((struct in6_aliasreq *)data)->ifra_addr);
510 			dst = (struct sockaddr *)
511 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
512 			break;
513 #endif
514 		default:
515 			goto bad;
516 		}
517 		/* sa_family must be equal */
518 		if (src->sa_family != dst->sa_family ||
519 		    src->sa_len != dst->sa_len)
520 			goto bad;
521 
522 		/* validate sa_len */
523 		switch (src->sa_family) {
524 #ifdef INET
525 		case AF_INET:
526 			if (src->sa_len != sizeof(struct sockaddr_in))
527 				goto bad;
528 			break;
529 #endif
530 #ifdef INET6
531 		case AF_INET6:
532 			if (src->sa_len != sizeof(struct sockaddr_in6))
533 				goto bad;
534 			break;
535 #endif
536 		default:
537 			error = EAFNOSUPPORT;
538 			goto bad;
539 		}
540 		/* check sa_family looks sane for the cmd */
541 		error = EAFNOSUPPORT;
542 		switch (cmd) {
543 #ifdef INET
544 		case SIOCSIFPHYADDR:
545 			if (src->sa_family == AF_INET)
546 				break;
547 			goto bad;
548 #endif
549 #ifdef INET6
550 		case SIOCSIFPHYADDR_IN6:
551 			if (src->sa_family == AF_INET6)
552 				break;
553 			goto bad;
554 #endif
555 		}
556 		error = EADDRNOTAVAIL;
557 		switch (src->sa_family) {
558 #ifdef INET
559 		case AF_INET:
560 			if (satosin(src)->sin_addr.s_addr == INADDR_ANY ||
561 			    satosin(dst)->sin_addr.s_addr == INADDR_ANY)
562 				goto bad;
563 			break;
564 #endif
565 #ifdef INET6
566 		case AF_INET6:
567 			if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(src)->sin6_addr)
568 			    ||
569 			    IN6_IS_ADDR_UNSPECIFIED(&satosin6(dst)->sin6_addr))
570 				goto bad;
571 			/*
572 			 * Check validity of the scope zone ID of the
573 			 * addresses, and convert it into the kernel
574 			 * internal form if necessary.
575 			 */
576 			error = sa6_embedscope(satosin6(src), 0);
577 			if (error != 0)
578 				goto bad;
579 			error = sa6_embedscope(satosin6(dst), 0);
580 			if (error != 0)
581 				goto bad;
582 #endif
583 		};
584 		error = ipsec_set_addresses(ifp, src, dst);
585 		break;
586 	case SIOCDIFPHYADDR:
587 		ipsec_delete_tunnel(ifp, 0);
588 		break;
589 	case SIOCGIFPSRCADDR:
590 	case SIOCGIFPDSTADDR:
591 #ifdef INET6
592 	case SIOCGIFPSRCADDR_IN6:
593 	case SIOCGIFPDSTADDR_IN6:
594 #endif
595 		IPSEC_RLOCK(sc);
596 		if (sc->family == 0) {
597 			IPSEC_RUNLOCK(sc);
598 			error = EADDRNOTAVAIL;
599 			break;
600 		}
601 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sc->family);
602 		switch (cmd) {
603 #ifdef INET
604 		case SIOCGIFPSRCADDR:
605 		case SIOCGIFPDSTADDR:
606 			if (saidx->src.sa.sa_family != AF_INET) {
607 				error = EADDRNOTAVAIL;
608 				break;
609 			}
610 			sin = (struct sockaddr_in *)&ifr->ifr_addr;
611 			memset(sin, 0, sizeof(*sin));
612 			sin->sin_family = AF_INET;
613 			sin->sin_len = sizeof(*sin);
614 			break;
615 #endif
616 #ifdef INET6
617 		case SIOCGIFPSRCADDR_IN6:
618 		case SIOCGIFPDSTADDR_IN6:
619 			if (saidx->src.sa.sa_family != AF_INET6) {
620 				error = EADDRNOTAVAIL;
621 				break;
622 			}
623 			sin6 = (struct sockaddr_in6 *)
624 				&(((struct in6_ifreq *)data)->ifr_addr);
625 			memset(sin6, 0, sizeof(*sin6));
626 			sin6->sin6_family = AF_INET6;
627 			sin6->sin6_len = sizeof(*sin6);
628 			break;
629 #endif
630 		default:
631 			error = EAFNOSUPPORT;
632 		}
633 		if (error == 0) {
634 			switch (cmd) {
635 #ifdef INET
636 			case SIOCGIFPSRCADDR:
637 				sin->sin_addr = saidx->src.sin.sin_addr;
638 				break;
639 			case SIOCGIFPDSTADDR:
640 				sin->sin_addr = saidx->dst.sin.sin_addr;
641 				break;
642 #endif
643 #ifdef INET6
644 			case SIOCGIFPSRCADDR_IN6:
645 				sin6->sin6_addr = saidx->src.sin6.sin6_addr;
646 				break;
647 			case SIOCGIFPDSTADDR_IN6:
648 				sin6->sin6_addr = saidx->dst.sin6.sin6_addr;
649 				break;
650 #endif
651 			}
652 		}
653 		IPSEC_RUNLOCK(sc);
654 		if (error != 0)
655 			break;
656 		switch (cmd) {
657 #ifdef INET
658 		case SIOCGIFPSRCADDR:
659 		case SIOCGIFPDSTADDR:
660 			error = prison_if(curthread->td_ucred,
661 			    (struct sockaddr *)sin);
662 			if (error != 0)
663 				memset(sin, 0, sizeof(*sin));
664 			break;
665 #endif
666 #ifdef INET6
667 		case SIOCGIFPSRCADDR_IN6:
668 		case SIOCGIFPDSTADDR_IN6:
669 			error = prison_if(curthread->td_ucred,
670 			    (struct sockaddr *)sin6);
671 			if (error == 0)
672 				error = sa6_recoverscope(sin6);
673 			if (error != 0)
674 				memset(sin6, 0, sizeof(*sin6));
675 #endif
676 		}
677 		break;
678 	case SIOCGTUNFIB:
679 		ifr->ifr_fib = sc->fibnum;
680 		break;
681 	case SIOCSTUNFIB:
682 		if ((error = priv_check(curthread, PRIV_NET_SETIFFIB)) != 0)
683 			break;
684 		if (ifr->ifr_fib >= rt_numfibs)
685 			error = EINVAL;
686 		else
687 			sc->fibnum = ifr->ifr_fib;
688 		break;
689 	case IPSECGREQID:
690 		reqid = sc->reqid;
691 		error = copyout(&reqid, ifr->ifr_data, sizeof(reqid));
692 		break;
693 	case IPSECSREQID:
694 		if ((error = priv_check(curthread, PRIV_NET_SETIFCAP)) != 0)
695 			break;
696 		error = copyin(ifr->ifr_data, &reqid, sizeof(reqid));
697 		if (error != 0)
698 			break;
699 		error = ipsec_set_reqid(ifp, reqid);
700 		break;
701 	default:
702 		error = EINVAL;
703 		break;
704 	}
705 bad:
706 	sx_xunlock(&ipsec_ioctl_sx);
707 	return (error);
708 }
709 
710 /*
711  * Allocate new private security policies for tunneling interface.
712  * Each tunneling interface has following security policies for
713  * both AF:
714  *   0.0.0.0/0[any] 0.0.0.0/0[any] -P in \
715  *	ipsec esp/tunnel/RemoteIP-LocalIP/unique:reqid
716  *   0.0.0.0/0[any] 0.0.0.0/0[any] -P out \
717  *	ipsec esp/tunnel/LocalIP-RemoteIP/unique:reqid
718  */
719 static int
720 ipsec_newpolicies(struct ipsec_softc *sc, struct secpolicy *sp[IPSEC_SPCOUNT],
721     const struct sockaddr *src, const struct sockaddr *dst, uint32_t reqid)
722 {
723 	struct ipsecrequest *isr;
724 	int i;
725 
726 	memset(sp, 0, sizeof(struct secpolicy *) * IPSEC_SPCOUNT);
727 	for (i = 0; i < IPSEC_SPCOUNT; i++) {
728 		if ((sp[i] = key_newsp()) == NULL)
729 			goto fail;
730 		if ((isr = ipsec_newisr()) == NULL)
731 			goto fail;
732 
733 		sp[i]->policy = IPSEC_POLICY_IPSEC;
734 		sp[i]->state = IPSEC_SPSTATE_DEAD;
735 		sp[i]->req[sp[i]->tcount++] = isr;
736 		sp[i]->created = time_second;
737 		/* Use priority field to store if_index */
738 		sp[i]->priority = sc->ifp->if_index;
739 		isr->level = IPSEC_LEVEL_UNIQUE;
740 		isr->saidx.proto = IPPROTO_ESP;
741 		isr->saidx.mode = IPSEC_MODE_TUNNEL;
742 		isr->saidx.reqid = reqid;
743 		if (i % 2 == 0) {
744 			sp[i]->spidx.dir = IPSEC_DIR_INBOUND;
745 			bcopy(src, &isr->saidx.dst, src->sa_len);
746 			bcopy(dst, &isr->saidx.src, dst->sa_len);
747 		} else {
748 			sp[i]->spidx.dir = IPSEC_DIR_OUTBOUND;
749 			bcopy(src, &isr->saidx.src, src->sa_len);
750 			bcopy(dst, &isr->saidx.dst, dst->sa_len);
751 		}
752 		sp[i]->spidx.ul_proto = IPSEC_ULPROTO_ANY;
753 #ifdef INET
754 		if (i < 2) {
755 			sp[i]->spidx.src.sa.sa_family =
756 			    sp[i]->spidx.dst.sa.sa_family = AF_INET;
757 			sp[i]->spidx.src.sa.sa_len =
758 			    sp[i]->spidx.dst.sa.sa_len =
759 			    sizeof(struct sockaddr_in);
760 			continue;
761 		}
762 #endif
763 #ifdef INET6
764 		sp[i]->spidx.src.sa.sa_family =
765 		    sp[i]->spidx.dst.sa.sa_family = AF_INET6;
766 		sp[i]->spidx.src.sa.sa_len =
767 		    sp[i]->spidx.dst.sa.sa_len = sizeof(struct sockaddr_in6);
768 #endif
769 	}
770 	return (0);
771 fail:
772 	for (i = 0; i < IPSEC_SPCOUNT; i++)
773 		key_freesp(&sp[i]);
774 	return (ENOMEM);
775 }
776 
777 static int
778 ipsec_check_reqid(uint32_t reqid)
779 {
780 	struct ipsec_softc *sc;
781 
782 	IPSEC_SC_RLOCK_ASSERT();
783 	LIST_FOREACH(sc, &V_ipsec_sc_list, chain) {
784 		if (sc->reqid == reqid)
785 			return (EEXIST);
786 	}
787 	return (0);
788 }
789 
790 /*
791  * We use key_newreqid() to automatically obtain unique reqid.
792  * Then we check that given id is unique, i.e. it is not used by
793  * another if_ipsec(4) interface. This macro limits the number of
794  * tries to get unique id.
795  */
796 #define	IPSEC_REQID_TRYCNT	64
797 static int
798 ipsec_init_reqid(struct ipsec_softc *sc)
799 {
800 	uint32_t reqid;
801 	int trycount;
802 
803 	IPSEC_SC_RLOCK_ASSERT();
804 
805 	if (sc->reqid != 0) /* already initialized */
806 		return (0);
807 
808 	trycount = IPSEC_REQID_TRYCNT;
809 	while (--trycount > 0) {
810 		reqid = key_newreqid();
811 		if (ipsec_check_reqid(reqid) == 0)
812 			break;
813 	}
814 	if (trycount == 0)
815 		return (EEXIST);
816 	sc->reqid = reqid;
817 	return (0);
818 }
819 
820 /*
821  * Set or update reqid for given tunneling interface.
822  * When specified reqid is zero, generate new one.
823  * We are protected by ioctl_sx lock from concurrent id generation.
824  * Also softc would not disappear while we hold ioctl_sx lock.
825  */
826 static int
827 ipsec_set_reqid(struct ifnet *ifp, uint32_t reqid)
828 {
829 	IPSEC_SC_RLOCK_TRACKER;
830 	struct ipsec_softc *sc;
831 	struct secasindex *saidx;
832 
833 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
834 
835 	sc = ifp->if_softc;
836 	if (sc->reqid == reqid && reqid != 0)
837 		return (0);
838 
839 	IPSEC_SC_RLOCK();
840 	if (reqid != 0) {
841 		/* Check that specified reqid doesn't exist */
842 		if (ipsec_check_reqid(reqid) != 0) {
843 			IPSEC_SC_RUNLOCK();
844 			return (EEXIST);
845 		}
846 		sc->reqid = reqid;
847 	} else {
848 		/* Generate new reqid */
849 		if (ipsec_init_reqid(sc) != 0) {
850 			IPSEC_SC_RUNLOCK();
851 			return (EEXIST);
852 		}
853 	}
854 	IPSEC_SC_RUNLOCK();
855 
856 	/* Tunnel isn't fully configured, just return. */
857 	if (sc->family == 0)
858 		return (0);
859 
860 	saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sc->family);
861 	KASSERT(saidx != NULL,
862 	    ("saidx is NULL, but family is %d", sc->family));
863 	return (ipsec_set_tunnel(sc, &saidx->src.sa, &saidx->dst.sa,
864 	    sc->reqid));
865 }
866 
867 /*
868  * Set tunnel endpoints addresses.
869  */
870 static int
871 ipsec_set_addresses(struct ifnet *ifp, struct sockaddr *src,
872     struct sockaddr *dst)
873 {
874 	IPSEC_SC_RLOCK_TRACKER;
875 	struct ipsec_softc *sc, *tsc;
876 	struct secasindex *saidx;
877 
878 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
879 
880 	sc = ifp->if_softc;
881 	if (sc->family != 0) {
882 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND,
883 		    src->sa_family);
884 		if (saidx != NULL && saidx->reqid == sc->reqid &&
885 		    key_sockaddrcmp(&saidx->src.sa, src, 0) == 0 &&
886 		    key_sockaddrcmp(&saidx->dst.sa, dst, 0) == 0)
887 			return (0); /* Nothing has been changed. */
888 
889 	}
890 	/*
891 	 * We cannot service IPsec tunnel when source address is
892 	 * not our own.
893 	 */
894 #ifdef INET
895 	if (src->sa_family == AF_INET &&
896 	    in_localip(satosin(src)->sin_addr) == 0)
897 		return (EADDRNOTAVAIL);
898 #endif
899 #ifdef INET6
900 	/*
901 	 * NOTE: IPv6 addresses are in kernel internal form with
902 	 * embedded scope zone id.
903 	 */
904 	if (src->sa_family == AF_INET6 &&
905 	    in6_localip(&satosin6(src)->sin6_addr) == 0)
906 		return (EADDRNOTAVAIL);
907 #endif
908 	/* Check that given addresses aren't already configured */
909 	IPSEC_SC_RLOCK();
910 	LIST_FOREACH(tsc, &V_ipsec_sc_list, chain) {
911 		if (tsc == sc || tsc->family != src->sa_family)
912 			continue;
913 		saidx = ipsec_getsaidx(tsc, IPSEC_DIR_OUTBOUND, tsc->family);
914 		if (key_sockaddrcmp(&saidx->src.sa, src, 0) == 0 &&
915 		    key_sockaddrcmp(&saidx->dst.sa, dst, 0) == 0) {
916 			/* We already have tunnel with such addresses */
917 			IPSEC_SC_RUNLOCK();
918 			return (EADDRNOTAVAIL);
919 		}
920 	}
921 	/* If reqid is not set, generate new one. */
922 	if (ipsec_init_reqid(sc) != 0) {
923 		IPSEC_SC_RUNLOCK();
924 		return (EEXIST);
925 	}
926 	IPSEC_SC_RUNLOCK();
927 	return (ipsec_set_tunnel(sc, src, dst, sc->reqid));
928 }
929 
930 static int
931 ipsec_set_tunnel(struct ipsec_softc *sc, struct sockaddr *src,
932     struct sockaddr *dst, uint32_t reqid)
933 {
934 	struct secpolicy *sp[IPSEC_SPCOUNT];
935 	struct secpolicy *oldsp[IPSEC_SPCOUNT];
936 	int i, f;
937 
938 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
939 
940 	/* Allocate SP with new addresses. */
941 	if (ipsec_newpolicies(sc, sp, src, dst, reqid) == 0) {
942 		/* Add new policies to SPDB */
943 		if (key_register_ifnet(sp, IPSEC_SPCOUNT) != 0) {
944 			for (i = 0; i < IPSEC_SPCOUNT; i++)
945 				key_freesp(&sp[i]);
946 			return (EAGAIN);
947 		}
948 		IPSEC_SC_WLOCK();
949 		if ((f = sc->family) != 0)
950 			LIST_REMOVE(sc, hash);
951 		IPSEC_WLOCK(sc);
952 		for (i = 0; i < IPSEC_SPCOUNT; i++) {
953 			oldsp[i] = sc->sp[i];
954 			sc->sp[i] = sp[i];
955 		}
956 		sc->family = src->sa_family;
957 		IPSEC_WUNLOCK(sc);
958 		LIST_INSERT_HEAD(SCHASH_HASH(sc->reqid), sc, hash);
959 		IPSEC_SC_WUNLOCK();
960 	} else {
961 		sc->ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
962 		return (ENOMEM);
963 	}
964 
965 	sc->ifp->if_drv_flags |= IFF_DRV_RUNNING;
966 	if (f != 0) {
967 		key_unregister_ifnet(oldsp, IPSEC_SPCOUNT);
968 		for (i = 0; i < IPSEC_SPCOUNT; i++)
969 			key_freesp(&oldsp[i]);
970 	}
971 	return (0);
972 }
973 
974 static void
975 ipsec_delete_tunnel(struct ifnet *ifp, int locked)
976 {
977 	struct ipsec_softc *sc = ifp->if_softc;
978 	struct secpolicy *oldsp[IPSEC_SPCOUNT];
979 	int i;
980 
981 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
982 
983 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
984 	if (sc->family != 0) {
985 		if (!locked)
986 			IPSEC_SC_WLOCK();
987 		/* Remove from hash table */
988 		LIST_REMOVE(sc, hash);
989 		IPSEC_WLOCK(sc);
990 		for (i = 0; i < IPSEC_SPCOUNT; i++) {
991 			oldsp[i] = sc->sp[i];
992 			sc->sp[i] = NULL;
993 		}
994 		sc->family = 0;
995 		IPSEC_WUNLOCK(sc);
996 		if (!locked)
997 			IPSEC_SC_WUNLOCK();
998 		key_unregister_ifnet(oldsp, IPSEC_SPCOUNT);
999 		for (i = 0; i < IPSEC_SPCOUNT; i++)
1000 			key_freesp(&oldsp[i]);
1001 	}
1002 }
1003