1/* $NetBSD: xform_ipip.c,v 1.42 2016/07/07 09:32:03 ozaki-r Exp $ */
2/* $FreeBSD: src/sys/netipsec/xform_ipip.c,v 1.3.2.1 2003/01/24 05:11:36 sam Exp $ */
3/* $OpenBSD: ip_ipip.c,v 1.25 2002/06/10 18:04:55 itojun Exp $ */
4
5/*
6 * The authors of this code are John Ioannidis (ji@tla.org),
7 * Angelos D. Keromytis (kermit@csd.uch.gr) and
8 * Niels Provos (provos@physnet.uni-hamburg.de).
9 *
10 * The original version of this code was written by John Ioannidis
11 * for BSD/OS in Athens, Greece, in November 1995.
12 *
13 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
14 * by Angelos D. Keromytis.
15 *
16 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
17 * and Niels Provos.
18 *
19 * Additional features in 1999 by Angelos D. Keromytis.
20 *
21 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
22 * Angelos D. Keromytis and Niels Provos.
23 * Copyright (c) 2001, Angelos D. Keromytis.
24 *
25 * Permission to use, copy, and modify this software with or without fee
26 * is hereby granted, provided that this entire notice is included in
27 * all copies of any software which is or includes a copy or
28 * modification of this software.
29 * You may use this code under the GNU public license if you so wish. Please
30 * contribute changes back to the authors under this freer than GPL license
31 * so that we may further the use of strong encryption without limitations to
32 * all.
33 *
34 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
35 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
36 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
37 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
38 * PURPOSE.
39 */
40
41#include <sys/cdefs.h>
42__KERNEL_RCSID(0, "$NetBSD: xform_ipip.c,v 1.42 2016/07/07 09:32:03 ozaki-r Exp $");
43
44/*
45 * IP-inside-IP processing
46 */
47#include "opt_inet.h"
48#ifdef __FreeBSD__
49#include "opt_inet6.h"
50#include "opt_random_ip_id.h"
51#endif /* __FreeBSD__ */
52
53
54#include <sys/param.h>
55#include <sys/systm.h>
56#include <sys/mbuf.h>
57#include <sys/socket.h>
58#include <sys/kernel.h>
59#include <sys/protosw.h>
60#include <sys/sysctl.h>
61
62#include <net/if.h>
63#include <net/route.h>
64#include <net/netisr.h>
65
66#include <netinet/in.h>
67#include <netinet/in_systm.h>
68#include <netinet/in_var.h>
69#include <netinet/ip.h>
70#include <netinet/ip_ecn.h>
71#include <netinet/ip_var.h>
72#include <netinet/ip_encap.h>
73#ifdef __FreeBSD__
74#include <netinet/ipprotosw.h>
75#endif
76
77#include <netipsec/ipsec.h>
78#include <netipsec/ipsec_private.h>
79#include <netipsec/xform.h>
80
81#include <netipsec/ipip_var.h>
82
83#ifdef MROUTING
84#include <netinet/ip_mroute.h>
85#endif
86
87#ifdef INET6
88#include <netinet/ip6.h>
89#include <netipsec/ipsec6.h>
90# ifdef __FreeBSD__
91# include <netinet6/ip6_ecn.h>
92# endif
93#include <netinet6/in6_var.h>
94#include <netinet6/ip6protosw.h>
95#endif
96
97#include <netipsec/key.h>
98#include <netipsec/key_debug.h>
99#include <netipsec/ipsec_osdep.h>
100
101#ifdef __FreeBSD__
102typedef void pr_in_input_t (struct mbuf *, int, int); /* XXX FIX THIS */
103#else
104typedef void pr_in_input_t (struct mbuf *m, ...);
105#endif
106
107/*
108 * We can control the acceptance of IP4 packets by altering the sysctl
109 * net.inet.ipip.allow value. Zero means drop them, all else is acceptance.
110 */
111int ipip_allow = 0;
112
113percpu_t *ipipstat_percpu;
114
115#ifdef SYSCTL_DECL
116SYSCTL_DECL(_net_inet_ipip);
117
118SYSCTL_INT(_net_inet_ipip, OID_AUTO,
119 ipip_allow, CTLFLAG_RW, &ipip_allow, 0, "");
120SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS,
121 stats, CTLFLAG_RD, &ipipstat, ipipstat, "");
122
123#endif
124
125#ifdef __FreeBSD__
126static
127#endif
128void ipe4_attach(void);
129
130
131/* XXX IPCOMP */
132#define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
133
134static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp);
135
136#ifdef INET6
137/*
138 * Really only a wrapper for ipip_input(), for use with IPv6.
139 */
140int
141ip4_input6(struct mbuf **m, int *offp, int proto)
142{
143#if 0
144 /* If we do not accept IP-in-IP explicitly, drop. */
145 if (!ipip_allow && ((*m)->m_flags & M_IPSEC) == 0) {
146 DPRINTF(("ip4_input6: dropped due to policy\n"));
147 IPIP_STATINC(IPIP_STAT_PDROPS);
148 m_freem(*m);
149 return IPPROTO_DONE;
150 }
151#endif
152 _ipip_input(*m, *offp, NULL);
153 return IPPROTO_DONE;
154}
155#endif /* INET6 */
156
157#ifdef INET
158/*
159 * Really only a wrapper for ipip_input(), for use with IPv4.
160 */
161void
162ip4_input(struct mbuf *m, int off, int proto)
163{
164
165#if 0
166 /* If we do not accept IP-in-IP explicitly, drop. */
167 if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) {
168 DPRINTF(("ip4_input: dropped due to policy\n"));
169 IPIP_STATINC(IPIP_STAT_PDROPS);
170 m_freem(m);
171 return;
172 }
173#endif
174
175 _ipip_input(m, off, NULL);
176}
177#endif /* INET */
178
179/*
180 * ipip_input gets called when we receive an IP{46} encapsulated packet,
181 * either because we got it at a real interface, or because AH or ESP
182 * were being used in tunnel mode (in which case the rcvif element will
183 * contain the address of the encX interface associated with the tunnel.
184 */
185
186static void
187_ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
188{
189 register struct sockaddr_in *sin;
190 register struct ifnet *ifp;
191 register struct ifaddr *ifa;
192 pktqueue_t *pktq = NULL;
193 struct ip *ipo;
194#ifdef INET6
195 register struct sockaddr_in6 *sin6;
196 struct ip6_hdr *ip6 = NULL;
197 u_int8_t itos;
198#endif
199 u_int8_t otos;
200 u_int8_t v;
201 int hlen;
202
203 IPIP_STATINC(IPIP_STAT_IPACKETS);
204
205 m_copydata(m, 0, 1, &v);
206
207 switch (v >> 4) {
208#ifdef INET
209 case 4:
210 hlen = sizeof(struct ip);
211 break;
212#endif /* INET */
213#ifdef INET6
214 case 6:
215 hlen = sizeof(struct ip6_hdr);
216 break;
217#endif
218 default:
219 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
220 "for outer header\n", v, v>>4));
221 IPIP_STATINC(IPIP_STAT_FAMILY);
222 m_freem(m);
223 return /* EAFNOSUPPORT */;
224 }
225
226 /* Bring the IP header in the first mbuf, if not there already */
227 if (m->m_len < hlen) {
228 if ((m = m_pullup(m, hlen)) == NULL) {
229 DPRINTF(("ipip_input: m_pullup (1) failed\n"));
230 IPIP_STATINC(IPIP_STAT_HDROPS);
231 return;
232 }
233 }
234
235 ipo = mtod(m, struct ip *);
236
237#ifdef MROUTING
238 if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) {
239 if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) {
240 ipip_mroute_input (m, iphlen);
241 return;
242 }
243 }
244#endif /* MROUTING */
245
246 /* Keep outer ecn field. */
247 switch (v >> 4) {
248#ifdef INET
249 case 4:
250 otos = ipo->ip_tos;
251 break;
252#endif /* INET */
253#ifdef INET6
254 case 6:
255 otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff;
256 break;
257#endif
258 default:
259 panic("ipip_input: unknown ip version %u (outer)", v>>4);
260 }
261
262 /* Remove outer IP header */
263 m_adj(m, iphlen);
264
265 /* Sanity check */
266 if (m->m_pkthdr.len < sizeof(struct ip)) {
267 IPIP_STATINC(IPIP_STAT_HDROPS);
268 m_freem(m);
269 return;
270 }
271
272 m_copydata(m, 0, 1, &v);
273
274 switch (v >> 4) {
275#ifdef INET
276 case 4:
277 hlen = sizeof(struct ip);
278 break;
279#endif /* INET */
280
281#ifdef INET6
282 case 6:
283 hlen = sizeof(struct ip6_hdr);
284 break;
285#endif
286 default:
287 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
288 "for inner header\n", v, v>>4));
289 IPIP_STATINC(IPIP_STAT_FAMILY);
290 m_freem(m);
291 return; /* EAFNOSUPPORT */
292 }
293
294 /*
295 * Bring the inner IP header in the first mbuf, if not there already.
296 */
297 if (m->m_len < hlen) {
298 if ((m = m_pullup(m, hlen)) == NULL) {
299 DPRINTF(("ipip_input: m_pullup (2) failed\n"));
300 IPIP_STATINC(IPIP_STAT_HDROPS);
301 return;
302 }
303 }
304
305 /*
306 * RFC 1853 specifies that the inner TTL should not be touched on
307 * decapsulation. There's no reason this comment should be here, but
308 * this is as good as any a position.
309 */
310
311 /* Some sanity checks in the inner IP header */
312 switch (v >> 4) {
313#ifdef INET
314 case 4:
315 ipo = mtod(m, struct ip *);
316 ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos);
317 break;
318#endif /* INET */
319#ifdef INET6
320 case 6:
321 ip6 = (struct ip6_hdr *) ipo;
322 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
323 ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos);
324 ip6->ip6_flow &= ~htonl(0xff << 20);
325 ip6->ip6_flow |= htonl((u_int32_t) itos << 20);
326 break;
327#endif
328 default:
329 panic("ipip_input: unknown ip version %u (inner)", v>>4);
330 }
331
332 /* Check for local address spoofing. */
333 if ((m_get_rcvif_NOMPSAFE(m) == NULL ||
334 !(m_get_rcvif_NOMPSAFE(m)->if_flags & IFF_LOOPBACK)) &&
335 ipip_allow != 2) {
336 int s = pserialize_read_enter();
337 IFNET_READER_FOREACH(ifp) {
338 IFADDR_READER_FOREACH(ifa, ifp) {
339#ifdef INET
340 if (ipo) {
341 if (ifa->ifa_addr->sa_family !=
342 AF_INET)
343 continue;
344
345 sin = (struct sockaddr_in *) ifa->ifa_addr;
346
347 if (sin->sin_addr.s_addr ==
348 ipo->ip_src.s_addr) {
349 pserialize_read_exit(s);
350 IPIP_STATINC(IPIP_STAT_SPOOF);
351 m_freem(m);
352 return;
353 }
354 }
355#endif /* INET */
356
357#ifdef INET6
358 if (ip6) {
359 if (ifa->ifa_addr->sa_family !=
360 AF_INET6)
361 continue;
362
363 sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
364
365 if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) {
366 pserialize_read_exit(s);
367 IPIP_STATINC(IPIP_STAT_SPOOF);
368 m_freem(m);
369 return;
370 }
371
372 }
373#endif /* INET6 */
374 }
375 }
376 pserialize_read_exit(s);
377 }
378
379 /* Statistics */
380 IPIP_STATADD(IPIP_STAT_IBYTES, m->m_pkthdr.len - iphlen);
381
382 /*
383 * Interface pointer stays the same; if no IPsec processing has
384 * been done (or will be done), this will point to a normal
385 * interface. Otherwise, it'll point to an enc interface, which
386 * will allow a packet filter to distinguish between secure and
387 * untrusted packets.
388 */
389
390 switch (v >> 4) {
391#ifdef INET
392 case 4:
393 pktq = ip_pktq;
394 break;
395#endif
396#ifdef INET6
397 case 6:
398 pktq = ip6_pktq;
399 break;
400#endif
401 default:
402 panic("ipip_input: should never reach here");
403 }
404
405 int s = splnet();
406 if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
407 IPIP_STATINC(IPIP_STAT_QFULL);
408 m_freem(m);
409 }
410 splx(s);
411}
412
413int
414ipip_output(
415 struct mbuf *m,
416 struct ipsecrequest *isr,
417 struct mbuf **mp,
418 int skip,
419 int protoff
420)
421{
422 const struct secasvar *sav;
423 u_int8_t tp, otos;
424 struct secasindex *saidx;
425 int error;
426#ifdef INET
427 u_int8_t itos;
428 struct ip *ipo;
429#endif /* INET */
430#ifdef INET6
431 struct ip6_hdr *ip6, *ip6o;
432#endif /* INET6 */
433
434 IPSEC_SPLASSERT_SOFTNET("ipip_output");
435
436 sav = isr->sav;
437 IPSEC_ASSERT(sav != NULL, ("ipip_output: null SA"));
438 IPSEC_ASSERT(sav->sah != NULL, ("ipip_output: null SAH"));
439
440 /* XXX Deal with empty TDB source/destination addresses. */
441
442 m_copydata(m, 0, 1, &tp);
443 tp = (tp >> 4) & 0xff; /* Get the IP version number. */
444
445 saidx = &sav->sah->saidx;
446 switch (saidx->dst.sa.sa_family) {
447#ifdef INET
448 case AF_INET:
449 if (saidx->src.sa.sa_family != AF_INET ||
450 saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
451 saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) {
452 DPRINTF(("ipip_output: unspecified tunnel endpoint "
453 "address in SA %s/%08lx\n",
454 ipsec_address(&saidx->dst),
455 (u_long) ntohl(sav->spi)));
456 IPIP_STATINC(IPIP_STAT_UNSPEC);
457 error = EINVAL;
458 goto bad;
459 }
460
461 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
462 if (m == 0) {
463 DPRINTF(("ipip_output: M_PREPEND failed\n"));
464 IPIP_STATINC(IPIP_STAT_HDROPS);
465 error = ENOBUFS;
466 goto bad;
467 }
468
469 ipo = mtod(m, struct ip *);
470
471 ipo->ip_v = IPVERSION;
472 ipo->ip_hl = 5;
473 ipo->ip_len = htons(m->m_pkthdr.len);
474 ipo->ip_ttl = ip_defttl;
475 ipo->ip_sum = 0;
476 ipo->ip_src = saidx->src.sin.sin_addr;
477 ipo->ip_dst = saidx->dst.sin.sin_addr;
478
479#if defined(__NetBSD__)
480 ipo->ip_id = ip_newid(NULL);
481#elif defined(RANDOM_IP_ID)
482 ipo->ip_id = ip_randomid();
483#else
484 ipo->ip_id = htons(ip_id++);
485#endif
486
487 /* If the inner protocol is IP... */
488 if (tp == IPVERSION) {
489 /* Save ECN notification */
490 m_copydata(m, sizeof(struct ip) +
491 offsetof(struct ip, ip_tos),
492 sizeof(u_int8_t), &itos);
493
494 ipo->ip_p = IPPROTO_IPIP;
495
496 /*
497 * We should be keeping tunnel soft-state and
498 * send back ICMPs if needed.
499 */
500 m_copydata(m, sizeof(struct ip) +
501 offsetof(struct ip, ip_off),
502 sizeof(u_int16_t), &ipo->ip_off);
503 ipo->ip_off &= ~ IP_OFF_CONVERT(IP_DF | IP_MF | IP_OFFMASK);
504 }
505#ifdef INET6
506 else if (tp == (IPV6_VERSION >> 4)) {
507 u_int32_t itos32;
508
509 /* Save ECN notification. */
510 m_copydata(m, sizeof(struct ip) +
511 offsetof(struct ip6_hdr, ip6_flow),
512 sizeof(u_int32_t), &itos32);
513 itos = ntohl(itos32) >> 20;
514 ipo->ip_p = IPPROTO_IPV6;
515 ipo->ip_off = 0;
516 }
517#endif /* INET6 */
518 else {
519 goto nofamily;
520 }
521
522 otos = 0;
523 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
524 ipo->ip_tos = otos;
525 break;
526#endif /* INET */
527
528#ifdef INET6
529 case AF_INET6:
530 if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) ||
531 saidx->src.sa.sa_family != AF_INET6 ||
532 IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) {
533 DPRINTF(("ipip_output: unspecified tunnel endpoint "
534 "address in SA %s/%08lx\n",
535 ipsec_address(&saidx->dst),
536 (u_long) ntohl(sav->spi)));
537 IPIP_STATINC(IPIP_STAT_UNSPEC);
538 error = ENOBUFS;
539 goto bad;
540 }
541
542 if (tp == (IPV6_VERSION >> 4)) {
543 /* scoped address handling */
544 ip6 = mtod(m, struct ip6_hdr *);
545 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
546 ip6->ip6_src.s6_addr16[1] = 0;
547 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
548 ip6->ip6_dst.s6_addr16[1] = 0;
549 }
550
551 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
552 if (m == 0) {
553 DPRINTF(("ipip_output: M_PREPEND failed\n"));
554 IPIP_STATINC(IPIP_STAT_HDROPS);
555 error = ENOBUFS;
556 goto bad;
557 }
558
559 /* Initialize IPv6 header */
560 ip6o = mtod(m, struct ip6_hdr *);
561 ip6o->ip6_flow = 0;
562 ip6o->ip6_vfc &= ~IPV6_VERSION_MASK;
563 ip6o->ip6_vfc |= IPV6_VERSION;
564 ip6o->ip6_plen = htons(m->m_pkthdr.len);
565 ip6o->ip6_hlim = ip_defttl;
566 ip6o->ip6_dst = saidx->dst.sin6.sin6_addr;
567 ip6o->ip6_src = saidx->src.sin6.sin6_addr;
568 if (IN6_IS_SCOPE_LINKLOCAL(&ip6o->ip6_dst))
569 ip6o->ip6_dst.s6_addr16[1] = htons(saidx->dst.sin6.sin6_scope_id);
570 if (IN6_IS_SCOPE_LINKLOCAL(&ip6o->ip6_src))
571 ip6o->ip6_src.s6_addr16[1] = htons(saidx->src.sin6.sin6_scope_id);
572
573#ifdef INET
574 if (tp == IPVERSION) {
575 /* Save ECN notification */
576 m_copydata(m, sizeof(struct ip6_hdr) +
577 offsetof(struct ip, ip_tos), sizeof(u_int8_t),
578 &itos);
579
580 /* This is really IPVERSION. */
581 ip6o->ip6_nxt = IPPROTO_IPIP;
582 } else
583#endif /* INET */
584 if (tp == (IPV6_VERSION >> 4)) {
585 u_int32_t itos32;
586
587 /* Save ECN notification. */
588 m_copydata(m, sizeof(struct ip6_hdr) +
589 offsetof(struct ip6_hdr, ip6_flow),
590 sizeof(u_int32_t), &itos32);
591 itos = ntohl(itos32) >> 20;
592
593 ip6o->ip6_nxt = IPPROTO_IPV6;
594 } else {
595 goto nofamily;
596 }
597
598 otos = 0;
599 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
600 ip6o->ip6_flow |= htonl((u_int32_t) otos << 20);
601 break;
602#endif /* INET6 */
603
604 default:
605nofamily:
606 DPRINTF(("ipip_output: unsupported protocol family %u\n",
607 saidx->dst.sa.sa_family));
608 IPIP_STATINC(IPIP_STAT_FAMILY);
609 error = EAFNOSUPPORT; /* XXX diffs from openbsd */
610 goto bad;
611 }
612
613 IPIP_STATINC(IPIP_STAT_OPACKETS);
614 *mp = m;
615
616#ifdef INET
617 if (saidx->dst.sa.sa_family == AF_INET) {
618#if 0
619 if (sav->tdb_xform->xf_type == XF_IP4)
620 tdb->tdb_cur_bytes +=
621 m->m_pkthdr.len - sizeof(struct ip);
622#endif
623 IPIP_STATADD(IPIP_STAT_OBYTES,
624 m->m_pkthdr.len - sizeof(struct ip));
625 }
626#endif /* INET */
627
628#ifdef INET6
629 if (saidx->dst.sa.sa_family == AF_INET6) {
630#if 0
631 if (sav->tdb_xform->xf_type == XF_IP4)
632 tdb->tdb_cur_bytes +=
633 m->m_pkthdr.len - sizeof(struct ip6_hdr);
634#endif
635 IPIP_STATADD(IPIP_STAT_OBYTES,
636 m->m_pkthdr.len - sizeof(struct ip6_hdr));
637 }
638#endif /* INET6 */
639
640 return 0;
641bad:
642 if (m)
643 m_freem(m);
644 *mp = NULL;
645 return (error);
646}
647
648static int
649ipe4_init(struct secasvar *sav, const struct xformsw *xsp)
650{
651 sav->tdb_xform = xsp;
652 return 0;
653}
654
655static int
656ipe4_zeroize(struct secasvar *sav)
657{
658 sav->tdb_xform = NULL;
659 return 0;
660}
661
662static int
663ipe4_input(
664 struct mbuf *m,
665 const struct secasvar *sav,
666 int skip,
667 int protoff
668)
669{
670 /* This is a rather serious mistake, so no conditional printing. */
671 printf("ipe4_input: should never be called\n");
672 if (m)
673 m_freem(m);
674 return EOPNOTSUPP;
675}
676
677static struct xformsw ipe4_xformsw = {
678 XF_IP4, 0, "IPv4 Simple Encapsulation",
679 ipe4_init, ipe4_zeroize, ipe4_input, ipip_output,
680 NULL,
681};
682
683#ifdef INET
684static struct encapsw ipe4_encapsw = {
685 .encapsw4 = {
686 .pr_input = ip4_input,
687 .pr_ctlinput = NULL,
688 }
689};
690#endif
691#ifdef INET6
692static struct encapsw ipe4_encapsw6 = {
693 .encapsw6 = {
694 .pr_input = ip4_input6,
695 .pr_ctlinput = NULL,
696 }
697};
698#endif
699
700/*
701 * Check the encapsulated packet to see if we want it
702 */
703static int
704ipe4_encapcheck(struct mbuf *m,
705 int off,
706 int proto,
707 void *arg
708)
709{
710 /*
711 * Only take packets coming from IPSEC tunnels; the rest
712 * must be handled by the gif tunnel code. Note that we
713 * also return a minimum priority when we want the packet
714 * so any explicit gif tunnels take precedence.
715 */
716 return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0);
717}
718
719INITFN void
720ipe4_attach(void)
721{
722
723 ipipstat_percpu = percpu_alloc(sizeof(uint64_t) * IPIP_NSTATS);
724
725 xform_register(&ipe4_xformsw);
726 /* attach to encapsulation framework */
727 /* XXX save return cookie for detach on module remove */
728
729 encapinit();
730 /* This function is called before ifinit(). Who else gets lock? */
731 (void)encap_lock_enter();
732 /* ipe4_encapsw and ipe4_encapsw must be added atomically */
733#ifdef INET
734 (void) encap_attach_func(AF_INET, -1,
735 ipe4_encapcheck, &ipe4_encapsw, NULL);
736#endif
737#ifdef INET6
738 (void) encap_attach_func(AF_INET6, -1,
739 ipe4_encapcheck, &ipe4_encapsw6, NULL);
740#endif
741 encap_lock_exit();
742}
743
744#ifdef SYSINIT
745SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL);
746#endif
747
748