xref: /freebsd/sys/net/if_ipsec.c (revision c1cdf6a42f0d951ba720688dfc6ce07608b02f6e)
1 /*-
2  * Copyright (c) 2016-2018 Yandex LLC
3  * Copyright (c) 2016-2018 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/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/sx.h>
46 #include <sys/errno.h>
47 #include <sys/sysctl.h>
48 #include <sys/priv.h>
49 #include <sys/proc.h>
50 #include <sys/conf.h>
51 
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/if_clone.h>
55 #include <net/if_types.h>
56 #include <net/bpf.h>
57 #include <net/route.h>
58 #include <net/vnet.h>
59 
60 #include <netinet/in.h>
61 #include <netinet/in_var.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip_encap.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 	struct secpolicy	*sp[IPSEC_SPCOUNT];
91 	uint32_t		reqid;
92 	u_int			family;
93 	u_int			fibnum;
94 
95 	CK_LIST_ENTRY(ipsec_softc) idhash;
96 	CK_LIST_ENTRY(ipsec_softc) srchash;
97 };
98 
99 #define	IPSEC_RLOCK_TRACKER	struct epoch_tracker ipsec_et
100 #define	IPSEC_RLOCK()	epoch_enter_preempt(net_epoch_preempt, &ipsec_et)
101 #define	IPSEC_RUNLOCK()	epoch_exit_preempt(net_epoch_preempt, &ipsec_et)
102 #define	IPSEC_WAIT()	epoch_wait_preempt(net_epoch_preempt)
103 
104 #ifndef IPSEC_HASH_SIZE
105 #define	IPSEC_HASH_SIZE	(1 << 5)
106 #endif
107 
108 CK_LIST_HEAD(ipsec_iflist, ipsec_softc);
109 VNET_DEFINE_STATIC(struct ipsec_iflist *, ipsec_idhtbl) = NULL;
110 #define	V_ipsec_idhtbl		VNET(ipsec_idhtbl)
111 
112 #ifdef INET
113 VNET_DEFINE_STATIC(struct ipsec_iflist *, ipsec4_srchtbl) = NULL;
114 #define	V_ipsec4_srchtbl	VNET(ipsec4_srchtbl)
115 static const struct srcaddrtab *ipsec4_srctab = NULL;
116 #endif
117 
118 #ifdef INET6
119 VNET_DEFINE_STATIC(struct ipsec_iflist *, ipsec6_srchtbl) = NULL;
120 #define	V_ipsec6_srchtbl	VNET(ipsec6_srchtbl)
121 static const struct srcaddrtab *ipsec6_srctab = NULL;
122 #endif
123 
124 static struct ipsec_iflist *
125 ipsec_idhash(uint32_t id)
126 {
127 
128 	return (&V_ipsec_idhtbl[fnv_32_buf(&id, sizeof(id),
129 	    FNV1_32_INIT) & (IPSEC_HASH_SIZE - 1)]);
130 }
131 
132 static struct ipsec_iflist *
133 ipsec_srchash(const struct sockaddr *sa)
134 {
135 	uint32_t hval;
136 
137 	switch (sa->sa_family) {
138 #ifdef INET
139 	case AF_INET:
140 		hval = fnv_32_buf(
141 		    &((const struct sockaddr_in *)sa)->sin_addr.s_addr,
142 		    sizeof(in_addr_t), FNV1_32_INIT);
143 		return (&V_ipsec4_srchtbl[hval & (IPSEC_HASH_SIZE - 1)]);
144 #endif
145 #ifdef INET6
146 	case AF_INET6:
147 		hval = fnv_32_buf(
148 		    &((const struct sockaddr_in6 *)sa)->sin6_addr,
149 		    sizeof(struct in6_addr), FNV1_32_INIT);
150 		return (&V_ipsec6_srchtbl[hval & (IPSEC_HASH_SIZE - 1)]);
151 #endif
152 	}
153 	return (NULL);
154 }
155 
156 /*
157  * ipsec_ioctl_sx protects from concurrent ioctls.
158  */
159 static struct sx ipsec_ioctl_sx;
160 SX_SYSINIT(ipsec_ioctl_sx, &ipsec_ioctl_sx, "ipsec_ioctl");
161 
162 static int	ipsec_init_reqid(struct ipsec_softc *);
163 static int	ipsec_set_tunnel(struct ipsec_softc *, struct sockaddr *,
164     struct sockaddr *, uint32_t);
165 static void	ipsec_delete_tunnel(struct ipsec_softc *);
166 
167 static int	ipsec_set_addresses(struct ifnet *, struct sockaddr *,
168     struct sockaddr *);
169 static int	ipsec_set_reqid(struct ipsec_softc *, uint32_t);
170 static void	ipsec_set_running(struct ipsec_softc *);
171 
172 static void	ipsec_srcaddr(void *, const struct sockaddr *, int);
173 static int	ipsec_ioctl(struct ifnet *, u_long, caddr_t);
174 static int	ipsec_transmit(struct ifnet *, struct mbuf *);
175 static int	ipsec_output(struct ifnet *, struct mbuf *,
176     const struct sockaddr *, struct route *);
177 static void	ipsec_qflush(struct ifnet *);
178 static int	ipsec_clone_create(struct if_clone *, int, caddr_t);
179 static void	ipsec_clone_destroy(struct ifnet *);
180 
181 VNET_DEFINE_STATIC(struct if_clone *, ipsec_cloner);
182 #define	V_ipsec_cloner		VNET(ipsec_cloner)
183 
184 static int
185 ipsec_clone_create(struct if_clone *ifc, int unit, caddr_t params)
186 {
187 	struct ipsec_softc *sc;
188 	struct ifnet *ifp;
189 
190 	sc = malloc(sizeof(*sc), M_IPSEC, M_WAITOK | M_ZERO);
191 	sc->fibnum = curthread->td_proc->p_fibnum;
192 	sc->ifp = ifp = if_alloc(IFT_TUNNEL);
193 	ifp->if_softc = sc;
194 	if_initname(ifp, ipsecname, unit);
195 
196 	ifp->if_addrlen = 0;
197 	ifp->if_mtu = IPSEC_MTU;
198 	ifp->if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
199 	ifp->if_ioctl  = ipsec_ioctl;
200 	ifp->if_transmit  = ipsec_transmit;
201 	ifp->if_qflush  = ipsec_qflush;
202 	ifp->if_output = ipsec_output;
203 	if_attach(ifp);
204 	bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
205 
206 	return (0);
207 }
208 
209 static void
210 ipsec_clone_destroy(struct ifnet *ifp)
211 {
212 	struct ipsec_softc *sc;
213 
214 	sx_xlock(&ipsec_ioctl_sx);
215 	sc = ifp->if_softc;
216 	ipsec_delete_tunnel(sc);
217 	bpfdetach(ifp);
218 	if_detach(ifp);
219 	ifp->if_softc = NULL;
220 	sx_xunlock(&ipsec_ioctl_sx);
221 
222 	IPSEC_WAIT();
223 	if_free(ifp);
224 	free(sc, M_IPSEC);
225 }
226 
227 static struct ipsec_iflist *
228 ipsec_hashinit(void)
229 {
230 	struct ipsec_iflist *hash;
231 	int i;
232 
233 	hash = malloc(sizeof(struct ipsec_iflist) * IPSEC_HASH_SIZE,
234 	    M_IPSEC, M_WAITOK);
235 	for (i = 0; i < IPSEC_HASH_SIZE; i++)
236 		CK_LIST_INIT(&hash[i]);
237 
238 	return (hash);
239 }
240 
241 static void
242 vnet_ipsec_init(const void *unused __unused)
243 {
244 
245 	V_ipsec_idhtbl = ipsec_hashinit();
246 #ifdef INET
247 	V_ipsec4_srchtbl = ipsec_hashinit();
248 	if (IS_DEFAULT_VNET(curvnet))
249 		ipsec4_srctab = ip_encap_register_srcaddr(ipsec_srcaddr,
250 		    NULL, M_WAITOK);
251 #endif
252 #ifdef INET6
253 	V_ipsec6_srchtbl = ipsec_hashinit();
254 	if (IS_DEFAULT_VNET(curvnet))
255 		ipsec6_srctab = ip6_encap_register_srcaddr(ipsec_srcaddr,
256 		    NULL, M_WAITOK);
257 #endif
258 	V_ipsec_cloner = if_clone_simple(ipsecname, ipsec_clone_create,
259 	    ipsec_clone_destroy, 0);
260 }
261 VNET_SYSINIT(vnet_ipsec_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
262     vnet_ipsec_init, NULL);
263 
264 static void
265 vnet_ipsec_uninit(const void *unused __unused)
266 {
267 
268 	if_clone_detach(V_ipsec_cloner);
269 	free(V_ipsec_idhtbl, M_IPSEC);
270 #ifdef INET
271 	if (IS_DEFAULT_VNET(curvnet))
272 		ip_encap_unregister_srcaddr(ipsec4_srctab);
273 	free(V_ipsec4_srchtbl, M_IPSEC);
274 #endif
275 #ifdef INET6
276 	if (IS_DEFAULT_VNET(curvnet))
277 		ip6_encap_unregister_srcaddr(ipsec6_srctab);
278 	free(V_ipsec6_srchtbl, M_IPSEC);
279 #endif
280 }
281 VNET_SYSUNINIT(vnet_ipsec_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
282     vnet_ipsec_uninit, NULL);
283 
284 static struct secpolicy *
285 ipsec_getpolicy(struct ipsec_softc *sc, int dir, sa_family_t af)
286 {
287 
288 	switch (af) {
289 #ifdef INET
290 	case AF_INET:
291 		return (sc->sp[(dir == IPSEC_DIR_INBOUND ? 0: 1)]);
292 #endif
293 #ifdef INET6
294 	case AF_INET6:
295 		return (sc->sp[(dir == IPSEC_DIR_INBOUND ? 0: 1)
296 #ifdef INET
297 			+ 2
298 #endif
299 		]);
300 #endif
301 	}
302 	return (NULL);
303 }
304 
305 static struct secasindex *
306 ipsec_getsaidx(struct ipsec_softc *sc, int dir, sa_family_t af)
307 {
308 	struct secpolicy *sp;
309 
310 	sp = ipsec_getpolicy(sc, dir, af);
311 	if (sp == NULL)
312 		return (NULL);
313 	return (&sp->req[0]->saidx);
314 }
315 
316 static int
317 ipsec_transmit(struct ifnet *ifp, struct mbuf *m)
318 {
319 	IPSEC_RLOCK_TRACKER;
320 	struct ipsec_softc *sc;
321 	struct secpolicy *sp;
322 	struct ip *ip;
323 	uint32_t af;
324 	int error;
325 
326 	IPSEC_RLOCK();
327 #ifdef MAC
328 	error = mac_ifnet_check_transmit(ifp, m);
329 	if (error) {
330 		m_freem(m);
331 		goto err;
332 	}
333 #endif
334 	error = ENETDOWN;
335 	sc = ifp->if_softc;
336 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
337 	    (ifp->if_flags & IFF_MONITOR) != 0 ||
338 	    (ifp->if_flags & IFF_UP) == 0 || sc->family == 0) {
339 		m_freem(m);
340 		goto err;
341 	}
342 
343 	/* Determine address family to correctly handle packet in BPF */
344 	ip = mtod(m, struct ip *);
345 	switch (ip->ip_v) {
346 #ifdef INET
347 	case IPVERSION:
348 		af = AF_INET;
349 		break;
350 #endif
351 #ifdef INET6
352 	case (IPV6_VERSION >> 4):
353 		af = AF_INET6;
354 		break;
355 #endif
356 	default:
357 		error = EAFNOSUPPORT;
358 		m_freem(m);
359 		goto err;
360 	}
361 
362 	/*
363 	 * Loop prevention.
364 	 * XXX: for now just check presence of IPSEC_OUT_DONE mbuf tag.
365 	 *      We can read full chain and compare destination address,
366 	 *      proto and mode from xform_history with values from softc.
367 	 */
368 	if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) {
369 		m_freem(m);
370 		goto err;
371 	}
372 
373 	sp = ipsec_getpolicy(sc, IPSEC_DIR_OUTBOUND, af);
374 	key_addref(sp);
375 	M_SETFIB(m, sc->fibnum);
376 
377 	BPF_MTAP2(ifp, &af, sizeof(af), m);
378 	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
379 	if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
380 
381 	switch (af) {
382 #ifdef INET
383 	case AF_INET:
384 		error = ipsec4_process_packet(m, sp, NULL);
385 		break;
386 #endif
387 #ifdef INET6
388 	case AF_INET6:
389 		error = ipsec6_process_packet(m, sp, NULL);
390 		break;
391 #endif
392 	default:
393 		panic("%s: unknown address family\n", __func__);
394 	}
395 err:
396 	if (error != 0)
397 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
398 	IPSEC_RUNLOCK();
399 	return (error);
400 }
401 
402 static void
403 ipsec_qflush(struct ifnet *ifp __unused)
404 {
405 
406 }
407 
408 static int
409 ipsec_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
410 	struct route *ro)
411 {
412 
413 	return (ifp->if_transmit(ifp, m));
414 }
415 
416 int
417 ipsec_if_input(struct mbuf *m, struct secasvar *sav, uint32_t af)
418 {
419 	IPSEC_RLOCK_TRACKER;
420 	struct secasindex *saidx;
421 	struct ipsec_softc *sc;
422 	struct ifnet *ifp;
423 
424 	if (sav->state != SADB_SASTATE_MATURE &&
425 	    sav->state != SADB_SASTATE_DYING) {
426 		m_freem(m);
427 		return (ENETDOWN);
428 	}
429 
430 	if (sav->sah->saidx.mode != IPSEC_MODE_TUNNEL ||
431 	    sav->sah->saidx.proto != IPPROTO_ESP)
432 		return (0);
433 
434 	IPSEC_RLOCK();
435 	CK_LIST_FOREACH(sc, ipsec_idhash(sav->sah->saidx.reqid), idhash) {
436 		if (sc->family == 0)
437 			continue;
438 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_INBOUND,
439 		    sav->sah->saidx.src.sa.sa_family);
440 		/* SA's reqid should match reqid in SP */
441 		if (saidx == NULL ||
442 		    sav->sah->saidx.reqid != saidx->reqid)
443 			continue;
444 		/* SAH's addresses should match tunnel endpoints. */
445 		if (key_sockaddrcmp(&sav->sah->saidx.dst.sa,
446 		    &saidx->dst.sa, 0) != 0)
447 			continue;
448 		if (key_sockaddrcmp(&sav->sah->saidx.src.sa,
449 		    &saidx->src.sa, 0) == 0)
450 			break;
451 	}
452 	if (sc == NULL) {
453 		IPSEC_RUNLOCK();
454 		/* Tunnel was not found. Nothing to do. */
455 		return (0);
456 	}
457 	ifp = sc->ifp;
458 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
459 	    (ifp->if_flags & IFF_UP) == 0) {
460 		IPSEC_RUNLOCK();
461 		m_freem(m);
462 		return (ENETDOWN);
463 	}
464 	/*
465 	 * We found matching and working tunnel.
466 	 * Set its ifnet as receiving interface.
467 	 */
468 	m->m_pkthdr.rcvif = ifp;
469 
470 	m_clrprotoflags(m);
471 	M_SETFIB(m, ifp->if_fib);
472 	BPF_MTAP2(ifp, &af, sizeof(af), m);
473 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
474 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
475 	if ((ifp->if_flags & IFF_MONITOR) != 0) {
476 		IPSEC_RUNLOCK();
477 		m_freem(m);
478 		return (ENETDOWN);
479 	}
480 	IPSEC_RUNLOCK();
481 	return (0);
482 }
483 
484 static int
485 ipsec_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
486 {
487 	struct ifreq *ifr = (struct ifreq*)data;
488 	struct sockaddr *dst, *src;
489 	struct ipsec_softc *sc;
490 	struct secasindex *saidx;
491 #ifdef INET
492 	struct sockaddr_in *sin = NULL;
493 #endif
494 #ifdef INET6
495 	struct sockaddr_in6 *sin6 = NULL;
496 #endif
497 	uint32_t reqid;
498 	int error;
499 
500 	switch (cmd) {
501 	case SIOCSIFADDR:
502 		ifp->if_flags |= IFF_UP;
503 	case SIOCADDMULTI:
504 	case SIOCDELMULTI:
505 	case SIOCGIFMTU:
506 	case SIOCSIFFLAGS:
507 		return (0);
508 	case SIOCSIFMTU:
509 		if (ifr->ifr_mtu < IPSEC_MTU_MIN ||
510 		    ifr->ifr_mtu > IPSEC_MTU_MAX)
511 			return (EINVAL);
512 		else
513 			ifp->if_mtu = ifr->ifr_mtu;
514 		return (0);
515 	}
516 	sx_xlock(&ipsec_ioctl_sx);
517 	sc = ifp->if_softc;
518 	/* Check that softc is still here */
519 	if (sc == NULL) {
520 		error = ENXIO;
521 		goto bad;
522 	}
523 	error = 0;
524 	switch (cmd) {
525 	case SIOCSIFPHYADDR:
526 #ifdef INET6
527 	case SIOCSIFPHYADDR_IN6:
528 #endif
529 		error = EINVAL;
530 		switch (cmd) {
531 #ifdef INET
532 		case SIOCSIFPHYADDR:
533 			src = (struct sockaddr *)
534 				&(((struct in_aliasreq *)data)->ifra_addr);
535 			dst = (struct sockaddr *)
536 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
537 			break;
538 #endif
539 #ifdef INET6
540 		case SIOCSIFPHYADDR_IN6:
541 			src = (struct sockaddr *)
542 				&(((struct in6_aliasreq *)data)->ifra_addr);
543 			dst = (struct sockaddr *)
544 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
545 			break;
546 #endif
547 		default:
548 			goto bad;
549 		}
550 		/* sa_family must be equal */
551 		if (src->sa_family != dst->sa_family ||
552 		    src->sa_len != dst->sa_len)
553 			goto bad;
554 
555 		/* validate sa_len */
556 		switch (src->sa_family) {
557 #ifdef INET
558 		case AF_INET:
559 			if (src->sa_len != sizeof(struct sockaddr_in))
560 				goto bad;
561 			break;
562 #endif
563 #ifdef INET6
564 		case AF_INET6:
565 			if (src->sa_len != sizeof(struct sockaddr_in6))
566 				goto bad;
567 			break;
568 #endif
569 		default:
570 			error = EAFNOSUPPORT;
571 			goto bad;
572 		}
573 		/* check sa_family looks sane for the cmd */
574 		error = EAFNOSUPPORT;
575 		switch (cmd) {
576 #ifdef INET
577 		case SIOCSIFPHYADDR:
578 			if (src->sa_family == AF_INET)
579 				break;
580 			goto bad;
581 #endif
582 #ifdef INET6
583 		case SIOCSIFPHYADDR_IN6:
584 			if (src->sa_family == AF_INET6)
585 				break;
586 			goto bad;
587 #endif
588 		}
589 		error = EADDRNOTAVAIL;
590 		switch (src->sa_family) {
591 #ifdef INET
592 		case AF_INET:
593 			if (satosin(src)->sin_addr.s_addr == INADDR_ANY ||
594 			    satosin(dst)->sin_addr.s_addr == INADDR_ANY)
595 				goto bad;
596 			break;
597 #endif
598 #ifdef INET6
599 		case AF_INET6:
600 			if (IN6_IS_ADDR_UNSPECIFIED(
601 			    &satosin6(src)->sin6_addr) ||
602 			    IN6_IS_ADDR_UNSPECIFIED(
603 			    &satosin6(dst)->sin6_addr))
604 				goto bad;
605 			/*
606 			 * Check validity of the scope zone ID of the
607 			 * addresses, and convert it into the kernel
608 			 * internal form if necessary.
609 			 */
610 			error = sa6_embedscope(satosin6(src), 0);
611 			if (error != 0)
612 				goto bad;
613 			error = sa6_embedscope(satosin6(dst), 0);
614 			if (error != 0)
615 				goto bad;
616 #endif
617 		};
618 		error = ipsec_set_addresses(ifp, src, dst);
619 		break;
620 	case SIOCDIFPHYADDR:
621 		ipsec_delete_tunnel(sc);
622 		break;
623 	case SIOCGIFPSRCADDR:
624 	case SIOCGIFPDSTADDR:
625 #ifdef INET6
626 	case SIOCGIFPSRCADDR_IN6:
627 	case SIOCGIFPDSTADDR_IN6:
628 #endif
629 		if (sc->family == 0) {
630 			error = EADDRNOTAVAIL;
631 			break;
632 		}
633 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sc->family);
634 		switch (cmd) {
635 #ifdef INET
636 		case SIOCGIFPSRCADDR:
637 		case SIOCGIFPDSTADDR:
638 			if (saidx->src.sa.sa_family != AF_INET) {
639 				error = EADDRNOTAVAIL;
640 				break;
641 			}
642 			sin = (struct sockaddr_in *)&ifr->ifr_addr;
643 			memset(sin, 0, sizeof(*sin));
644 			sin->sin_family = AF_INET;
645 			sin->sin_len = sizeof(*sin);
646 			break;
647 #endif
648 #ifdef INET6
649 		case SIOCGIFPSRCADDR_IN6:
650 		case SIOCGIFPDSTADDR_IN6:
651 			if (saidx->src.sa.sa_family != AF_INET6) {
652 				error = EADDRNOTAVAIL;
653 				break;
654 			}
655 			sin6 = (struct sockaddr_in6 *)
656 				&(((struct in6_ifreq *)data)->ifr_addr);
657 			memset(sin6, 0, sizeof(*sin6));
658 			sin6->sin6_family = AF_INET6;
659 			sin6->sin6_len = sizeof(*sin6);
660 			break;
661 #endif
662 		default:
663 			error = EAFNOSUPPORT;
664 		}
665 		if (error == 0) {
666 			switch (cmd) {
667 #ifdef INET
668 			case SIOCGIFPSRCADDR:
669 				sin->sin_addr = saidx->src.sin.sin_addr;
670 				break;
671 			case SIOCGIFPDSTADDR:
672 				sin->sin_addr = saidx->dst.sin.sin_addr;
673 				break;
674 #endif
675 #ifdef INET6
676 			case SIOCGIFPSRCADDR_IN6:
677 				sin6->sin6_addr = saidx->src.sin6.sin6_addr;
678 				break;
679 			case SIOCGIFPDSTADDR_IN6:
680 				sin6->sin6_addr = saidx->dst.sin6.sin6_addr;
681 				break;
682 #endif
683 			}
684 		}
685 		if (error != 0)
686 			break;
687 		switch (cmd) {
688 #ifdef INET
689 		case SIOCGIFPSRCADDR:
690 		case SIOCGIFPDSTADDR:
691 			error = prison_if(curthread->td_ucred,
692 			    (struct sockaddr *)sin);
693 			if (error != 0)
694 				memset(sin, 0, sizeof(*sin));
695 			break;
696 #endif
697 #ifdef INET6
698 		case SIOCGIFPSRCADDR_IN6:
699 		case SIOCGIFPDSTADDR_IN6:
700 			error = prison_if(curthread->td_ucred,
701 			    (struct sockaddr *)sin6);
702 			if (error == 0)
703 				error = sa6_recoverscope(sin6);
704 			if (error != 0)
705 				memset(sin6, 0, sizeof(*sin6));
706 #endif
707 		}
708 		break;
709 	case SIOCGTUNFIB:
710 		ifr->ifr_fib = sc->fibnum;
711 		break;
712 	case SIOCSTUNFIB:
713 		if ((error = priv_check(curthread, PRIV_NET_SETIFFIB)) != 0)
714 			break;
715 		if (ifr->ifr_fib >= rt_numfibs)
716 			error = EINVAL;
717 		else
718 			sc->fibnum = ifr->ifr_fib;
719 		break;
720 	case IPSECGREQID:
721 		reqid = sc->reqid;
722 		error = copyout(&reqid, ifr_data_get_ptr(ifr), sizeof(reqid));
723 		break;
724 	case IPSECSREQID:
725 		if ((error = priv_check(curthread, PRIV_NET_SETIFCAP)) != 0)
726 			break;
727 		error = copyin(ifr_data_get_ptr(ifr), &reqid, sizeof(reqid));
728 		if (error != 0)
729 			break;
730 		error = ipsec_set_reqid(sc, reqid);
731 		break;
732 	default:
733 		error = EINVAL;
734 		break;
735 	}
736 bad:
737 	sx_xunlock(&ipsec_ioctl_sx);
738 	return (error);
739 }
740 
741 /*
742  * Check that ingress address belongs to local host.
743  */
744 static void
745 ipsec_set_running(struct ipsec_softc *sc)
746 {
747 	struct secasindex *saidx;
748 	int localip;
749 
750 	saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sc->family);
751 	localip = 0;
752 	switch (sc->family) {
753 #ifdef INET
754 	case AF_INET:
755 		localip = in_localip(saidx->src.sin.sin_addr);
756 		break;
757 #endif
758 #ifdef INET6
759 	case AF_INET6:
760 		localip = in6_localip(&saidx->src.sin6.sin6_addr);
761 		break;
762 #endif
763 	}
764 	if (localip != 0)
765 		sc->ifp->if_drv_flags |= IFF_DRV_RUNNING;
766 	else
767 		sc->ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
768 }
769 
770 /*
771  * ifaddr_event handler.
772  * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
773  * source address spoofing.
774  */
775 static void
776 ipsec_srcaddr(void *arg __unused, const struct sockaddr *sa,
777     int event __unused)
778 {
779 	struct ipsec_softc *sc;
780 	struct secasindex *saidx;
781 
782 	MPASS(in_epoch(net_epoch_preempt));
783 	CK_LIST_FOREACH(sc, ipsec_srchash(sa), srchash) {
784 		if (sc->family == 0)
785 			continue;
786 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sa->sa_family);
787 		if (saidx == NULL ||
788 		    key_sockaddrcmp(&saidx->src.sa, sa, 0) != 0)
789 			continue;
790 		ipsec_set_running(sc);
791 	}
792 }
793 
794 /*
795  * Allocate new private security policies for tunneling interface.
796  * Each tunneling interface has following security policies for
797  * both AF:
798  *   0.0.0.0/0[any] 0.0.0.0/0[any] -P in \
799  *	ipsec esp/tunnel/RemoteIP-LocalIP/unique:reqid
800  *   0.0.0.0/0[any] 0.0.0.0/0[any] -P out \
801  *	ipsec esp/tunnel/LocalIP-RemoteIP/unique:reqid
802  */
803 static int
804 ipsec_newpolicies(struct ipsec_softc *sc, struct secpolicy *sp[IPSEC_SPCOUNT],
805     const struct sockaddr *src, const struct sockaddr *dst, uint32_t reqid)
806 {
807 	struct ipsecrequest *isr;
808 	int i;
809 
810 	memset(sp, 0, sizeof(struct secpolicy *) * IPSEC_SPCOUNT);
811 	for (i = 0; i < IPSEC_SPCOUNT; i++) {
812 		if ((sp[i] = key_newsp()) == NULL)
813 			goto fail;
814 		if ((isr = ipsec_newisr()) == NULL)
815 			goto fail;
816 
817 		sp[i]->policy = IPSEC_POLICY_IPSEC;
818 		sp[i]->state = IPSEC_SPSTATE_DEAD;
819 		sp[i]->req[sp[i]->tcount++] = isr;
820 		sp[i]->created = time_second;
821 		/* Use priority field to store if_index */
822 		sp[i]->priority = sc->ifp->if_index;
823 		isr->level = IPSEC_LEVEL_UNIQUE;
824 		isr->saidx.proto = IPPROTO_ESP;
825 		isr->saidx.mode = IPSEC_MODE_TUNNEL;
826 		isr->saidx.reqid = reqid;
827 		if (i % 2 == 0) {
828 			sp[i]->spidx.dir = IPSEC_DIR_INBOUND;
829 			bcopy(src, &isr->saidx.dst, src->sa_len);
830 			bcopy(dst, &isr->saidx.src, dst->sa_len);
831 		} else {
832 			sp[i]->spidx.dir = IPSEC_DIR_OUTBOUND;
833 			bcopy(src, &isr->saidx.src, src->sa_len);
834 			bcopy(dst, &isr->saidx.dst, dst->sa_len);
835 		}
836 		sp[i]->spidx.ul_proto = IPSEC_ULPROTO_ANY;
837 #ifdef INET
838 		if (i < 2) {
839 			sp[i]->spidx.src.sa.sa_family =
840 			    sp[i]->spidx.dst.sa.sa_family = AF_INET;
841 			sp[i]->spidx.src.sa.sa_len =
842 			    sp[i]->spidx.dst.sa.sa_len =
843 			    sizeof(struct sockaddr_in);
844 			continue;
845 		}
846 #endif
847 #ifdef INET6
848 		sp[i]->spidx.src.sa.sa_family =
849 		    sp[i]->spidx.dst.sa.sa_family = AF_INET6;
850 		sp[i]->spidx.src.sa.sa_len =
851 		    sp[i]->spidx.dst.sa.sa_len = sizeof(struct sockaddr_in6);
852 #endif
853 	}
854 	return (0);
855 fail:
856 	for (i = 0; i < IPSEC_SPCOUNT; i++)
857 		key_freesp(&sp[i]);
858 	return (ENOMEM);
859 }
860 
861 static int
862 ipsec_check_reqid(uint32_t reqid)
863 {
864 	struct ipsec_softc *sc;
865 
866 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
867 	CK_LIST_FOREACH(sc, ipsec_idhash(reqid), idhash) {
868 		if (sc->reqid == reqid)
869 			return (EEXIST);
870 	}
871 	return (0);
872 }
873 
874 /*
875  * We use key_newreqid() to automatically obtain unique reqid.
876  * Then we check that given id is unique, i.e. it is not used by
877  * another if_ipsec(4) interface. This macro limits the number of
878  * tries to get unique id.
879  */
880 #define	IPSEC_REQID_TRYCNT	64
881 static int
882 ipsec_init_reqid(struct ipsec_softc *sc)
883 {
884 	uint32_t reqid;
885 	int trycount;
886 
887 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
888 	if (sc->reqid != 0) /* already initialized */
889 		return (0);
890 
891 	trycount = IPSEC_REQID_TRYCNT;
892 	while (--trycount > 0) {
893 		reqid = key_newreqid();
894 		if (ipsec_check_reqid(reqid) == 0)
895 			break;
896 	}
897 	if (trycount == 0)
898 		return (EEXIST);
899 	sc->reqid = reqid;
900 	CK_LIST_INSERT_HEAD(ipsec_idhash(reqid), sc, idhash);
901 	return (0);
902 }
903 
904 /*
905  * Set or update reqid for given tunneling interface.
906  * When specified reqid is zero, generate new one.
907  * We are protected by ioctl_sx lock from concurrent id generation.
908  * Also softc would not disappear while we hold ioctl_sx lock.
909  */
910 static int
911 ipsec_set_reqid(struct ipsec_softc *sc, uint32_t reqid)
912 {
913 	struct secasindex *saidx;
914 
915 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
916 
917 	if (sc->reqid == reqid && reqid != 0)
918 		return (0);
919 
920 	if (reqid != 0) {
921 		/* Check that specified reqid doesn't exist */
922 		if (ipsec_check_reqid(reqid) != 0)
923 			return (EEXIST);
924 		if (sc->reqid != 0) {
925 			CK_LIST_REMOVE(sc, idhash);
926 			IPSEC_WAIT();
927 		}
928 		sc->reqid = reqid;
929 		CK_LIST_INSERT_HEAD(ipsec_idhash(reqid), sc, idhash);
930 	} else {
931 		/* Generate new reqid */
932 		if (ipsec_init_reqid(sc) != 0)
933 			return (EEXIST);
934 	}
935 
936 	/* Tunnel isn't fully configured, just return. */
937 	if (sc->family == 0)
938 		return (0);
939 
940 	saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND, sc->family);
941 	KASSERT(saidx != NULL,
942 	    ("saidx is NULL, but family is %d", sc->family));
943 	return (ipsec_set_tunnel(sc, &saidx->src.sa, &saidx->dst.sa,
944 	    sc->reqid));
945 }
946 
947 /*
948  * Set tunnel endpoints addresses.
949  */
950 static int
951 ipsec_set_addresses(struct ifnet *ifp, struct sockaddr *src,
952     struct sockaddr *dst)
953 {
954 	struct ipsec_softc *sc, *tsc;
955 	struct secasindex *saidx;
956 
957 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
958 
959 	sc = ifp->if_softc;
960 	if (sc->family != 0) {
961 		saidx = ipsec_getsaidx(sc, IPSEC_DIR_OUTBOUND,
962 		    src->sa_family);
963 		if (saidx != NULL && saidx->reqid == sc->reqid &&
964 		    key_sockaddrcmp(&saidx->src.sa, src, 0) == 0 &&
965 		    key_sockaddrcmp(&saidx->dst.sa, dst, 0) == 0)
966 			return (0); /* Nothing has been changed. */
967 
968 	}
969 	/* Check that given addresses aren't already configured */
970 	CK_LIST_FOREACH(tsc, ipsec_srchash(src), srchash) {
971 		if (tsc == sc)
972 			continue;
973 		MPASS(tsc->family == src->sa_family);
974 		saidx = ipsec_getsaidx(tsc, IPSEC_DIR_OUTBOUND, tsc->family);
975 		if (key_sockaddrcmp(&saidx->src.sa, src, 0) == 0 &&
976 		    key_sockaddrcmp(&saidx->dst.sa, dst, 0) == 0) {
977 			/* We already have tunnel with such addresses */
978 			return (EADDRNOTAVAIL);
979 		}
980 	}
981 	/* If reqid is not set, generate new one. */
982 	if (ipsec_init_reqid(sc) != 0)
983 		return (EEXIST);
984 	return (ipsec_set_tunnel(sc, src, dst, sc->reqid));
985 }
986 
987 static int
988 ipsec_set_tunnel(struct ipsec_softc *sc, struct sockaddr *src,
989     struct sockaddr *dst, uint32_t reqid)
990 {
991 	struct secpolicy *sp[IPSEC_SPCOUNT];
992 	int i;
993 
994 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
995 
996 	/* Allocate SP with new addresses. */
997 	if (ipsec_newpolicies(sc, sp, src, dst, reqid) == 0) {
998 		/* Add new policies to SPDB */
999 		if (key_register_ifnet(sp, IPSEC_SPCOUNT) != 0) {
1000 			for (i = 0; i < IPSEC_SPCOUNT; i++)
1001 				key_freesp(&sp[i]);
1002 			return (EAGAIN);
1003 		}
1004 		if (sc->family != 0)
1005 			ipsec_delete_tunnel(sc);
1006 		for (i = 0; i < IPSEC_SPCOUNT; i++)
1007 			sc->sp[i] = sp[i];
1008 		sc->family = src->sa_family;
1009 		CK_LIST_INSERT_HEAD(ipsec_srchash(src), sc, srchash);
1010 	} else {
1011 		sc->ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1012 		return (ENOMEM);
1013 	}
1014 	ipsec_set_running(sc);
1015 	return (0);
1016 }
1017 
1018 static void
1019 ipsec_delete_tunnel(struct ipsec_softc *sc)
1020 {
1021 	int i;
1022 
1023 	sx_assert(&ipsec_ioctl_sx, SA_XLOCKED);
1024 
1025 	sc->ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1026 	if (sc->family != 0) {
1027 		CK_LIST_REMOVE(sc, srchash);
1028 		IPSEC_WAIT();
1029 
1030 		/*
1031 		 * Make sure that ipsec_if_input() will not do access
1032 		 * to softc's policies.
1033 		 */
1034 		sc->family = 0;
1035 		IPSEC_WAIT();
1036 
1037 		key_unregister_ifnet(sc->sp, IPSEC_SPCOUNT);
1038 		for (i = 0; i < IPSEC_SPCOUNT; i++)
1039 			key_freesp(&sc->sp[i]);
1040 	}
1041 }
1042