xref: /netbsd-src/sys/netipsec/xform_ipip.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: xform_ipip.c,v 1.20 2007/12/07 19:46:18 elad 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 1.20 2007/12/07 19:46:18 elad 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/xform.h>
79 
80 #include <netipsec/ipip_var.h>
81 
82 #ifdef MROUTING
83 #include <netinet/ip_mroute.h>
84 #endif
85 
86 #ifdef INET6
87 #include <netinet/ip6.h>
88 #include <netipsec/ipsec6.h>
89 #  ifdef __FreeBSD__
90 #  include <netinet6/ip6_ecn.h>
91 #  endif
92 #include <netinet6/in6_var.h>
93 #include <netinet6/ip6protosw.h>
94 #endif
95 
96 #include <netipsec/key.h>
97 #include <netipsec/key_debug.h>
98 #include <netipsec/ipsec_osdep.h>
99 
100 #include <machine/stdarg.h>
101 
102 #ifdef __FreeBSD__
103 typedef void	pr_in_input_t (struct mbuf *, int, int); /* XXX FIX THIS */
104 #else
105 typedef void	pr_in_input_t (struct mbuf *m, ...);
106 #endif
107 
108 /*
109  * We can control the acceptance of IP4 packets by altering the sysctl
110  * net.inet.ipip.allow value.  Zero means drop them, all else is acceptance.
111  */
112 int	ipip_allow = 0;
113 struct	ipipstat ipipstat;
114 
115 #ifdef SYSCTL_DECL
116 SYSCTL_DECL(_net_inet_ipip);
117 
118 SYSCTL_INT(_net_inet_ipip, OID_AUTO,
119 	ipip_allow,	CTLFLAG_RW,	&ipip_allow,	0, "");
120 SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS,
121 	stats,		CTLFLAG_RD,	&ipipstat,	ipipstat, "");
122 
123 #endif
124 
125 #ifdef __FreeBSD__
126 static
127 #endif
128 void ipe4_attach(void);
129 
130 
131 /* XXX IPCOMP */
132 #define	M_IPSEC	(M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
133 
134 static 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  */
140 int
141 ip4_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 		ipipstat.ipips_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  */
161 void
162 ip4_input(struct mbuf *m, ...)
163 {
164 	va_list ap;
165 	int iphlen;
166 
167 #if 0
168 	/* If we do not accept IP-in-IP explicitly, drop.  */
169 	if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) {
170 		DPRINTF(("ip4_input: dropped due to policy\n"));
171 		ipipstat.ipips_pdrops++;
172 		m_freem(m);
173 		return;
174 	}
175 #endif
176 	va_start(ap, m);
177 	iphlen = va_arg(ap, int);
178 	va_end(ap);
179 
180 	_ipip_input(m, iphlen, NULL);
181 }
182 #endif /* INET */
183 
184 /*
185  * ipip_input gets called when we receive an IP{46} encapsulated packet,
186  * either because we got it at a real interface, or because AH or ESP
187  * were being used in tunnel mode (in which case the rcvif element will
188  * contain the address of the encX interface associated with the tunnel.
189  */
190 
191 static void
192 _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
193 {
194 	register struct sockaddr_in *sin;
195 	register struct ifnet *ifp;
196 	register struct ifaddr *ifa;
197 	struct ifqueue *ifq = NULL;
198 	struct ip *ipo;
199 #ifdef INET6
200 	register struct sockaddr_in6 *sin6;
201 	struct ip6_hdr *ip6 = NULL;
202 	u_int8_t itos;
203 #endif
204 	u_int8_t nxt;
205 	int isr;
206 	u_int8_t otos;
207 	u_int8_t v;
208 	int hlen;
209 
210 	ipipstat.ipips_ipackets++;
211 
212 	m_copydata(m, 0, 1, &v);
213 
214 	switch (v >> 4) {
215 #ifdef INET
216         case 4:
217 		hlen = sizeof(struct ip);
218 		break;
219 #endif /* INET */
220 #ifdef INET6
221         case 6:
222 		hlen = sizeof(struct ip6_hdr);
223 		break;
224 #endif
225         default:
226 		DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
227 			"for outer header\n", v, v>>4));
228 		ipipstat.ipips_family++;
229 		m_freem(m);
230 		return /* EAFNOSUPPORT */;
231 	}
232 
233 	/* Bring the IP header in the first mbuf, if not there already */
234 	if (m->m_len < hlen) {
235 		if ((m = m_pullup(m, hlen)) == NULL) {
236 			DPRINTF(("ipip_input: m_pullup (1) failed\n"));
237 			ipipstat.ipips_hdrops++;
238 			return;
239 		}
240 	}
241 
242 	ipo = mtod(m, struct ip *);
243 
244 #ifdef MROUTING
245 	if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) {
246 		if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) {
247 			ipip_mroute_input (m, iphlen);
248 			return;
249 		}
250 	}
251 #endif /* MROUTING */
252 
253 	/* Keep outer ecn field. */
254 	switch (v >> 4) {
255 #ifdef INET
256 	case 4:
257 		otos = ipo->ip_tos;
258 		break;
259 #endif /* INET */
260 #ifdef INET6
261 	case 6:
262 		otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff;
263 		break;
264 #endif
265 	default:
266 		panic("ipip_input: unknown ip version %u (outer)", v>>4);
267 	}
268 
269 	/* Remove outer IP header */
270 	m_adj(m, iphlen);
271 
272 	/* Sanity check */
273 	if (m->m_pkthdr.len < sizeof(struct ip))  {
274 		ipipstat.ipips_hdrops++;
275 		m_freem(m);
276 		return;
277 	}
278 
279 	m_copydata(m, 0, 1, &v);
280 
281 	switch (v >> 4) {
282 #ifdef INET
283         case 4:
284 		hlen = sizeof(struct ip);
285 		break;
286 #endif /* INET */
287 
288 #ifdef INET6
289         case 6:
290 		hlen = sizeof(struct ip6_hdr);
291 		break;
292 #endif
293 	default:
294 		DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
295 			"for inner header\n", v, v>>4));
296 		ipipstat.ipips_family++;
297 		m_freem(m);
298 		return; /* EAFNOSUPPORT */
299 	}
300 
301 	/*
302 	 * Bring the inner IP header in the first mbuf, if not there already.
303 	 */
304 	if (m->m_len < hlen) {
305 		if ((m = m_pullup(m, hlen)) == NULL) {
306 			DPRINTF(("ipip_input: m_pullup (2) failed\n"));
307 			ipipstat.ipips_hdrops++;
308 			return;
309 		}
310 	}
311 
312 	/*
313 	 * RFC 1853 specifies that the inner TTL should not be touched on
314 	 * decapsulation. There's no reason this comment should be here, but
315 	 * this is as good as any a position.
316 	 */
317 
318 	/* Some sanity checks in the inner IP header */
319 	switch (v >> 4) {
320 #ifdef INET
321     	case 4:
322                 ipo = mtod(m, struct ip *);
323                 nxt = ipo->ip_p;
324 		ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos);
325                 break;
326 #endif /* INET */
327 #ifdef INET6
328     	case 6:
329                 ip6 = (struct ip6_hdr *) ipo;
330                 nxt = ip6->ip6_nxt;
331 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
332 		ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos);
333 		ip6->ip6_flow &= ~htonl(0xff << 20);
334 		ip6->ip6_flow |= htonl((u_int32_t) itos << 20);
335                 break;
336 #endif
337 	default:
338 		panic("ipip_input: unknown ip version %u (inner)", v>>4);
339 	}
340 
341 	/* Check for local address spoofing. */
342 	if ((m->m_pkthdr.rcvif == NULL ||
343 	    !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) &&
344 	    ipip_allow != 2) {
345 		IFNET_FOREACH(ifp) {
346 			IFADDR_FOREACH(ifa, ifp) {
347 #ifdef INET
348 				if (ipo) {
349 					if (ifa->ifa_addr->sa_family !=
350 					    AF_INET)
351 						continue;
352 
353 					sin = (struct sockaddr_in *) ifa->ifa_addr;
354 
355 					if (sin->sin_addr.s_addr ==
356 					    ipo->ip_src.s_addr)	{
357 						ipipstat.ipips_spoof++;
358 						m_freem(m);
359 						return;
360 					}
361 				}
362 #endif /* INET */
363 
364 #ifdef INET6
365 				if (ip6) {
366 					if (ifa->ifa_addr->sa_family !=
367 					    AF_INET6)
368 						continue;
369 
370 					sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
371 
372 					if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) {
373 						ipipstat.ipips_spoof++;
374 						m_freem(m);
375 						return;
376 					}
377 
378 				}
379 #endif /* INET6 */
380 			}
381 		}
382 	}
383 
384 	/* Statistics */
385 	ipipstat.ipips_ibytes += m->m_pkthdr.len - iphlen;
386 
387 	/*
388 	 * Interface pointer stays the same; if no IPsec processing has
389 	 * been done (or will be done), this will point to a normal
390 	 * interface. Otherwise, it'll point to an enc interface, which
391 	 * will allow a packet filter to distinguish between secure and
392 	 * untrusted packets.
393 	 */
394 
395 	switch (v >> 4) {
396 #ifdef INET
397 	case 4:
398 		ifq = &ipintrq;
399 		isr = NETISR_IP;
400 		break;
401 #endif
402 #ifdef INET6
403 	case 6:
404 		ifq = &ip6intrq;
405 		isr = NETISR_IPV6;
406 		break;
407 #endif
408 	default:
409 		panic("ipip_input: should never reach here");
410 	}
411 
412 	if (!IF_HANDOFF(ifq, m, NULL)) {
413 		ipipstat.ipips_qfull++;
414 
415 		DPRINTF(("ipip_input: packet dropped because of full queue\n"));
416 	} else {
417 		schednetisr(isr);
418 	}
419 }
420 
421 int
422 ipip_output(
423     struct mbuf *m,
424     struct ipsecrequest *isr,
425     struct mbuf **mp,
426     int skip,
427     int protoff
428 )
429 {
430 	struct secasvar *sav;
431 	u_int8_t tp, otos;
432 	struct secasindex *saidx;
433 	int error;
434 #ifdef INET
435 	u_int8_t itos;
436 	struct ip *ipo;
437 #endif /* INET */
438 #ifdef INET6
439 	struct ip6_hdr *ip6, *ip6o;
440 #endif /* INET6 */
441 
442 	IPSEC_SPLASSERT_SOFTNET("ipip_output");
443 
444 	sav = isr->sav;
445 	IPSEC_ASSERT(sav != NULL, ("ipip_output: null SA"));
446 	IPSEC_ASSERT(sav->sah != NULL, ("ipip_output: null SAH"));
447 
448 	/* XXX Deal with empty TDB source/destination addresses. */
449 
450 	m_copydata(m, 0, 1, &tp);
451 	tp = (tp >> 4) & 0xff;  /* Get the IP version number. */
452 
453 	saidx = &sav->sah->saidx;
454 	switch (saidx->dst.sa.sa_family) {
455 #ifdef INET
456 	case AF_INET:
457 		if (saidx->src.sa.sa_family != AF_INET ||
458 		    saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
459 		    saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) {
460 			DPRINTF(("ipip_output: unspecified tunnel endpoint "
461 			    "address in SA %s/%08lx\n",
462 			    ipsec_address(&saidx->dst),
463 			    (u_long) ntohl(sav->spi)));
464 			ipipstat.ipips_unspec++;
465 			error = EINVAL;
466 			goto bad;
467 		}
468 
469 		M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
470 		if (m == 0) {
471 			DPRINTF(("ipip_output: M_PREPEND failed\n"));
472 			ipipstat.ipips_hdrops++;
473 			error = ENOBUFS;
474 			goto bad;
475 		}
476 
477 		ipo = mtod(m, struct ip *);
478 
479 		ipo->ip_v = IPVERSION;
480 		ipo->ip_hl = 5;
481 		ipo->ip_len = htons(m->m_pkthdr.len);
482 		ipo->ip_ttl = ip_defttl;
483 		ipo->ip_sum = 0;
484 		ipo->ip_src = saidx->src.sin.sin_addr;
485 		ipo->ip_dst = saidx->dst.sin.sin_addr;
486 
487 #if defined(__NetBSD__)
488 		ipo->ip_id = ip_newid();
489 #elif defined(RANDOM_IP_ID)
490 		ipo->ip_id = ip_randomid();
491 #else
492 		ipo->ip_id = htons(ip_id++);
493 #endif
494 
495 		/* If the inner protocol is IP... */
496 		if (tp == IPVERSION) {
497 			/* Save ECN notification */
498 			m_copydata(m, sizeof(struct ip) +
499 			    offsetof(struct ip, ip_tos),
500 			    sizeof(u_int8_t), &itos);
501 
502 			ipo->ip_p = IPPROTO_IPIP;
503 
504 			/*
505 			 * We should be keeping tunnel soft-state and
506 			 * send back ICMPs if needed.
507 			 */
508 			m_copydata(m, sizeof(struct ip) +
509 			    offsetof(struct ip, ip_off),
510 			    sizeof(u_int16_t), &ipo->ip_off);
511 			ipo->ip_off &= ~ IP_OFF_CONVERT(IP_DF | IP_MF | IP_OFFMASK);
512 		}
513 #ifdef INET6
514 		else if (tp == (IPV6_VERSION >> 4)) {
515 			u_int32_t itos32;
516 
517 			/* Save ECN notification. */
518 			m_copydata(m, sizeof(struct ip) +
519 			    offsetof(struct ip6_hdr, ip6_flow),
520 			    sizeof(u_int32_t), &itos32);
521 			itos = ntohl(itos32) >> 20;
522 			ipo->ip_p = IPPROTO_IPV6;
523 			ipo->ip_off = 0;
524 		}
525 #endif /* INET6 */
526 		else {
527 			goto nofamily;
528 		}
529 
530 		otos = 0;
531 		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
532 		ipo->ip_tos = otos;
533 		break;
534 #endif /* INET */
535 
536 #ifdef INET6
537 	case AF_INET6:
538 		if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) ||
539 		    saidx->src.sa.sa_family != AF_INET6 ||
540 		    IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) {
541 			DPRINTF(("ipip_output: unspecified tunnel endpoint "
542 			    "address in SA %s/%08lx\n",
543 			    ipsec_address(&saidx->dst),
544 			    (u_long) ntohl(sav->spi)));
545 			ipipstat.ipips_unspec++;
546 			error = ENOBUFS;
547 			goto bad;
548 		}
549 
550 		/* scoped address handling */
551 		ip6 = mtod(m, struct ip6_hdr *);
552 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
553 			ip6->ip6_src.s6_addr16[1] = 0;
554 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
555 			ip6->ip6_dst.s6_addr16[1] = 0;
556 
557 		M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
558 		if (m == 0) {
559 			DPRINTF(("ipip_output: M_PREPEND failed\n"));
560 			ipipstat.ipips_hdrops++;
561 			error = ENOBUFS;
562 			goto bad;
563 		}
564 
565 		/* Initialize IPv6 header */
566 		ip6o = mtod(m, struct ip6_hdr *);
567 		ip6o->ip6_flow = 0;
568 		ip6o->ip6_vfc &= ~IPV6_VERSION_MASK;
569 		ip6o->ip6_vfc |= IPV6_VERSION;
570 		ip6o->ip6_plen = htons(m->m_pkthdr.len);
571 		ip6o->ip6_hlim = ip_defttl;
572 		ip6o->ip6_dst = saidx->dst.sin6.sin6_addr;
573 		ip6o->ip6_src = saidx->src.sin6.sin6_addr;
574 
575 #ifdef INET
576 		if (tp == IPVERSION) {
577 			/* Save ECN notification */
578 			m_copydata(m, sizeof(struct ip6_hdr) +
579 			    offsetof(struct ip, ip_tos), sizeof(u_int8_t),
580 			    &itos);
581 
582 			/* This is really IPVERSION. */
583 			ip6o->ip6_nxt = IPPROTO_IPIP;
584 		} else
585 #endif /* INET */
586 			if (tp == (IPV6_VERSION >> 4)) {
587 				u_int32_t itos32;
588 
589 				/* Save ECN notification. */
590 				m_copydata(m, sizeof(struct ip6_hdr) +
591 				    offsetof(struct ip6_hdr, ip6_flow),
592 				    sizeof(u_int32_t), &itos32);
593 				itos = ntohl(itos32) >> 20;
594 
595 				ip6o->ip6_nxt = IPPROTO_IPV6;
596 			} else {
597 				goto nofamily;
598 			}
599 
600 		otos = 0;
601 		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
602 		ip6o->ip6_flow |= htonl((u_int32_t) otos << 20);
603 		break;
604 #endif /* INET6 */
605 
606 	default:
607 nofamily:
608 		DPRINTF(("ipip_output: unsupported protocol family %u\n",
609 		    saidx->dst.sa.sa_family));
610 		ipipstat.ipips_family++;
611 		error = EAFNOSUPPORT;		/* XXX diffs from openbsd */
612 		goto bad;
613 	}
614 
615 	ipipstat.ipips_opackets++;
616 	*mp = m;
617 
618 #ifdef INET
619 	if (saidx->dst.sa.sa_family == AF_INET) {
620 #if 0
621 		if (sav->tdb_xform->xf_type == XF_IP4)
622 			tdb->tdb_cur_bytes +=
623 			    m->m_pkthdr.len - sizeof(struct ip);
624 #endif
625 		ipipstat.ipips_obytes += m->m_pkthdr.len - sizeof(struct ip);
626 	}
627 #endif /* INET */
628 
629 #ifdef INET6
630 	if (saidx->dst.sa.sa_family == AF_INET6) {
631 #if 0
632 		if (sav->tdb_xform->xf_type == XF_IP4)
633 			tdb->tdb_cur_bytes +=
634 			    m->m_pkthdr.len - sizeof(struct ip6_hdr);
635 #endif
636 		ipipstat.ipips_obytes +=
637 		    m->m_pkthdr.len - sizeof(struct ip6_hdr);
638 	}
639 #endif /* INET6 */
640 
641 	return 0;
642 bad:
643 	if (m)
644 		m_freem(m);
645 	*mp = NULL;
646 	return (error);
647 }
648 
649 #ifdef FAST_IPSEC
650 static int
651 ipe4_init(struct secasvar *sav, struct xformsw *xsp)
652 {
653 	sav->tdb_xform = xsp;
654 	return 0;
655 }
656 
657 static int
658 ipe4_zeroize(struct secasvar *sav)
659 {
660 	sav->tdb_xform = NULL;
661 	return 0;
662 }
663 
664 static int
665 ipe4_input(
666     struct mbuf *m,
667     struct secasvar *sav,
668     int skip,
669     int protoff
670 )
671 {
672 	/* This is a rather serious mistake, so no conditional printing. */
673 	printf("ipe4_input: should never be called\n");
674 	if (m)
675 		m_freem(m);
676 	return EOPNOTSUPP;
677 }
678 
679 static struct xformsw ipe4_xformsw = {
680 	XF_IP4,		0,		"IPv4 Simple Encapsulation",
681 	ipe4_init,	ipe4_zeroize,	ipe4_input,	ipip_output,
682 	NULL,
683 };
684 
685 #ifdef INET
686 extern struct domain inetdomain;
687 static struct ipprotosw ipe4_protosw = {
688  .pr_type = SOCK_RAW,
689  .pr_domain = &inetdomain,
690  .pr_protocol = IPPROTO_IPV4,
691  .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
692  .pr_input = ip4_input,
693  .pr_output = 0,
694  .pr_ctlinput = 0,
695  .pr_ctloutput = rip_ctloutput,
696  .pr_usrreq = rip_usrreq,
697  .pr_init = 0,
698  .pr_fasttimo = 0,
699  .pr_slowtimo =	0,
700  .pr_drain = 0,
701 };
702 #endif
703 #ifdef INET6
704 extern struct domain inet6domain;
705 static struct ip6protosw ipe4_protosw6 = {
706  .pr_type = SOCK_RAW,
707  .pr_domain = &inet6domain,
708  .pr_protocol = IPPROTO_IPV6,
709  .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
710  .pr_input = ip4_input6,
711  .pr_output = 0,
712  .pr_ctlinput = 0,
713  .pr_ctloutput = rip6_ctloutput,
714  .pr_usrreq = rip6_usrreq,
715  .pr_init = 0,
716  .pr_fasttimo = 0,
717  .pr_slowtimo = 0,
718  .pr_drain = 0,
719 };
720 #endif
721 
722 #endif /* FAST_IPSEC */
723 
724 /*
725  * Check the encapsulated packet to see if we want it
726  */
727 static int
728 ipe4_encapcheck(struct mbuf *m,
729     int off,
730     int proto,
731     void *arg
732 )
733 {
734 	/*
735 	 * Only take packets coming from IPSEC tunnels; the rest
736 	 * must be handled by the gif tunnel code.  Note that we
737 	 * also return a minimum priority when we want the packet
738 	 * so any explicit gif tunnels take precedence.
739 	 */
740 	return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0);
741 }
742 
743 INITFN void
744 ipe4_attach(void)
745 {
746 	xform_register(&ipe4_xformsw);
747 	/* attach to encapsulation framework */
748 	/* XXX save return cookie for detach on module remove */
749 #ifdef INET
750 	(void) encap_attach_func(AF_INET, -1,
751 		ipe4_encapcheck, (struct protosw*) &ipe4_protosw, NULL);
752 #endif
753 #ifdef INET6
754 	(void) encap_attach_func(AF_INET6, -1,
755 		ipe4_encapcheck, (struct protosw*) &ipe4_protosw6, NULL);
756 #endif
757 }
758 
759 #ifdef SYSINIT
760 SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL);
761 #endif
762 
763