1 /* $FreeBSD: src/sys/netipsec/xform_ipip.c,v 1.3.2.1 2003/01/24 05:11:36 sam Exp $ */
2 /* $DragonFly: src/sys/netproto/ipsec/xform_ipip.c,v 1.14 2006/12/22 23:57:54 swildner Exp $ */
3 /* $OpenBSD: ip_ipip.c,v 1.25 2002/06/10 18:04:55 itojun Exp $ */
5 * The authors of this code are John Ioannidis (ji@tla.org),
6 * Angelos D. Keromytis (kermit@csd.uch.gr) and
7 * Niels Provos (provos@physnet.uni-hamburg.de).
9 * The original version of this code was written by John Ioannidis
10 * for BSD/OS in Athens, Greece, in November 1995.
12 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
13 * by Angelos D. Keromytis.
15 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
18 * Additional features in 1999 by Angelos D. Keromytis.
20 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
21 * Angelos D. Keromytis and Niels Provos.
22 * Copyright (c) 2001, Angelos D. Keromytis.
24 * Permission to use, copy, and modify this software with or without fee
25 * is hereby granted, provided that this entire notice is included in
26 * all copies of any software which is or includes a copy or
27 * modification of this software.
28 * You may use this code under the GNU public license if you so wish. Please
29 * contribute changes back to the authors under this freer than GPL license
30 * so that we may further the use of strong encryption without limitations to
33 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
34 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
35 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
36 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
41 * IP-inside-IP processing
44 #include "opt_inet6.h"
46 #include <sys/param.h>
47 #include <sys/systm.h>
49 #include <sys/socket.h>
50 #include <sys/kernel.h>
51 #include <sys/protosw.h>
52 #include <sys/sysctl.h>
55 #include <net/route.h>
56 #include <net/netisr.h>
58 #include <netinet/in.h>
59 #include <netinet/in_systm.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip_ecn.h>
63 #include <netinet/ip_var.h>
64 #include <netinet/ip_encap.h>
66 #include <netproto/ipsec/ipsec.h>
67 #include <netproto/ipsec/xform.h>
69 #include <netproto/ipsec/ipip_var.h>
72 #include <netinet/ip_mroute.h>
76 #include <netinet/ip6.h>
77 #include <netproto/ipsec/ipsec6.h>
78 #include <netinet6/ip6_ecn.h>
79 #include <netinet6/in6_var.h>
80 #include <netinet6/ip6protosw.h>
83 #include <netproto/ipsec/key.h>
84 #include <netproto/ipsec/key_debug.h>
86 #include <machine/stdarg.h>
88 typedef void pr_in_input_t (struct mbuf
*, int, int); /* XXX FIX THIS */
91 * We can control the acceptance of IP4 packets by altering the sysctl
92 * net.inet.ipip.allow value. Zero means drop them, all else is acceptance.
95 struct ipipstat ipipstat
;
97 SYSCTL_DECL(_net_inet_ipip
);
98 SYSCTL_INT(_net_inet_ipip
, OID_AUTO
,
99 ipip_allow
, CTLFLAG_RW
, &ipip_allow
, 0, "");
100 SYSCTL_STRUCT(_net_inet_ipip
, IPSECCTL_STATS
,
101 stats
, CTLFLAG_RD
, &ipipstat
, ipipstat
, "");
104 #define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
106 static void _ipip_input(struct mbuf
*m
, int iphlen
, struct ifnet
*gifp
);
110 * Really only a wrapper for ipip_input(), for use with IPv6.
113 ip4_input6(struct mbuf
**m
, int *offp
, int proto
)
116 /* If we do not accept IP-in-IP explicitly, drop. */
117 if (!ipip_allow
&& ((*m
)->m_flags
& M_IPSEC
) == 0) {
118 DPRINTF(("ip4_input6: dropped due to policy\n"));
119 ipipstat
.ipips_pdrops
++;
124 _ipip_input(*m
, *offp
, NULL
);
131 * Really only a wrapper for ipip_input(), for use with IPv4.
134 ip4_input(struct mbuf
*m
, ...)
140 /* If we do not accept IP-in-IP explicitly, drop. */
141 if (!ipip_allow
&& (m
->m_flags
& M_IPSEC
) == 0) {
142 DPRINTF(("ip4_input: dropped due to policy\n"));
143 ipipstat
.ipips_pdrops
++;
149 iphlen
= __va_arg(ap
, int);
152 _ipip_input(m
, iphlen
, NULL
);
157 * ipip_input gets called when we receive an IP{46} encapsulated packet,
158 * either because we got it at a real interface, or because AH or ESP
159 * were being used in tunnel mode (in which case the rcvif element will
160 * contain the address of the encX interface associated with the tunnel.
164 _ipip_input(struct mbuf
*m
, int iphlen
, struct ifnet
*gifp
)
166 struct sockaddr_in
*sin
;
171 struct sockaddr_in6
*sin6
;
172 struct ip6_hdr
*ip6
= NULL
;
181 ipipstat
.ipips_ipackets
++;
183 m_copydata(m
, 0, 1, &v
);
188 hlen
= sizeof(struct ip
);
193 hlen
= sizeof(struct ip6_hdr
);
197 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
198 "for outer header\n", v
, v
>>4));
199 ipipstat
.ipips_family
++;
201 return /* EAFNOSUPPORT */;
204 /* Bring the IP header in the first mbuf, if not there already */
205 if (m
->m_len
< hlen
) {
206 if ((m
= m_pullup(m
, hlen
)) == NULL
) {
207 DPRINTF(("ipip_input: m_pullup (1) failed\n"));
208 ipipstat
.ipips_hdrops
++;
213 ipo
= mtod(m
, struct ip
*);
216 if (ipo
->ip_v
== IPVERSION
&& ipo
->ip_p
== IPPROTO_IPV4
) {
217 if (IN_MULTICAST(((struct ip
*)((char *) ipo
+ iphlen
))->ip_dst
.s_addr
)) {
218 ipip_mroute_input (m
, iphlen
);
222 #endif /* MROUTING */
224 /* Keep outer ecn field. */
233 otos
= (ntohl(mtod(m
, struct ip6_hdr
*)->ip6_flow
) >> 20) & 0xff;
237 panic("ipip_input: unknown ip version %u (outer)", v
>>4);
240 /* Remove outer IP header */
244 if (m
->m_pkthdr
.len
< sizeof(struct ip
)) {
245 ipipstat
.ipips_hdrops
++;
250 m_copydata(m
, 0, 1, &v
);
255 hlen
= sizeof(struct ip
);
261 hlen
= sizeof(struct ip6_hdr
);
265 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
266 "for inner header\n", v
, v
>>4));
267 ipipstat
.ipips_family
++;
269 return; /* EAFNOSUPPORT */
273 * Bring the inner IP header in the first mbuf, if not there already.
275 if (m
->m_len
< hlen
) {
276 if ((m
= m_pullup(m
, hlen
)) == NULL
) {
277 DPRINTF(("ipip_input: m_pullup (2) failed\n"));
278 ipipstat
.ipips_hdrops
++;
284 * RFC 1853 specifies that the inner TTL should not be touched on
285 * decapsulation. There's no reason this comment should be here, but
286 * this is as good as any a position.
289 /* Some sanity checks in the inner IP header */
293 ipo
= mtod(m
, struct ip
*);
295 ip_ecn_egress(ip4_ipsec_ecn
, &otos
, &ipo
->ip_tos
);
300 ip6
= (struct ip6_hdr
*) ipo
;
302 itos
= (ntohl(ip6
->ip6_flow
) >> 20) & 0xff;
303 ip_ecn_egress(ip6_ipsec_ecn
, &otos
, &itos
);
304 ip6
->ip6_flow
&= ~htonl(0xff << 20);
305 ip6
->ip6_flow
|= htonl((u_int32_t
) itos
<< 20);
309 panic("ipip_input: unknown ip version %u (inner)", v
>>4);
312 /* Check for local address spoofing. */
313 if ((m
->m_pkthdr
.rcvif
== NULL
||
314 !(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
)) &&
316 TAILQ_FOREACH(ifp
, &ifnet
, if_link
) {
317 TAILQ_FOREACH(ifa
, &ifp
->if_addrlist
, ifa_link
) {
320 if (ifa
->ifa_addr
->sa_family
!=
324 sin
= (struct sockaddr_in
*) ifa
->ifa_addr
;
326 if (sin
->sin_addr
.s_addr
==
327 ipo
->ip_src
.s_addr
) {
328 ipipstat
.ipips_spoof
++;
337 if (ifa
->ifa_addr
->sa_family
!=
341 sin6
= (struct sockaddr_in6
*) ifa
->ifa_addr
;
343 if (IN6_ARE_ADDR_EQUAL(&sin6
->sin6_addr
, &ip6
->ip6_src
)) {
344 ipipstat
.ipips_spoof
++;
356 ipipstat
.ipips_ibytes
+= m
->m_pkthdr
.len
- iphlen
;
359 * Interface pointer stays the same; if no IPsec processing has
360 * been done (or will be done), this will point to a normal
361 * interface. Otherwise, it'll point to an enc interface, which
362 * will allow a packet filter to distinguish between secure and
378 panic("ipip_input: should never reach here");
381 if (netisr_queue(isr
, m
)) {
382 ipipstat
.ipips_qfull
++;
384 DPRINTF(("ipip_input: packet dropped because of full queue\n"));
391 struct ipsecrequest
*isr
,
397 struct secasvar
*sav
;
399 struct secasindex
*saidx
;
406 struct ip6_hdr
*ip6
, *ip6o
;
410 KASSERT(sav
!= NULL
, ("ipip_output: null SA"));
411 KASSERT(sav
->sah
!= NULL
, ("ipip_output: null SAH"));
413 /* XXX Deal with empty TDB source/destination addresses. */
415 m_copydata(m
, 0, 1, &tp
);
416 tp
= (tp
>> 4) & 0xff; /* Get the IP version number. */
418 saidx
= &sav
->sah
->saidx
;
419 switch (saidx
->dst
.sa
.sa_family
) {
422 if (saidx
->src
.sa
.sa_family
!= AF_INET
||
423 saidx
->src
.sin
.sin_addr
.s_addr
== INADDR_ANY
||
424 saidx
->dst
.sin
.sin_addr
.s_addr
== INADDR_ANY
) {
425 DPRINTF(("ipip_output: unspecified tunnel endpoint "
426 "address in SA %s/%08lx\n",
427 ipsec_address(&saidx
->dst
),
428 (u_long
) ntohl(sav
->spi
)));
429 ipipstat
.ipips_unspec
++;
434 M_PREPEND(m
, sizeof(struct ip
), MB_DONTWAIT
);
436 DPRINTF(("ipip_output: M_PREPEND failed\n"));
437 ipipstat
.ipips_hdrops
++;
442 ipo
= mtod(m
, struct ip
*);
444 ipo
->ip_v
= IPVERSION
;
446 ipo
->ip_len
= htons(m
->m_pkthdr
.len
);
447 ipo
->ip_ttl
= ip_defttl
;
449 ipo
->ip_src
= saidx
->src
.sin
.sin_addr
;
450 ipo
->ip_dst
= saidx
->dst
.sin
.sin_addr
;
452 ipo
->ip_id
= ip_newid();
454 /* If the inner protocol is IP... */
455 if (tp
== IPVERSION
) {
456 /* Save ECN notification */
457 m_copydata(m
, sizeof(struct ip
) +
458 offsetof(struct ip
, ip_tos
),
459 sizeof(u_int8_t
), (caddr_t
) &itos
);
461 ipo
->ip_p
= IPPROTO_IPIP
;
464 * We should be keeping tunnel soft-state and
465 * send back ICMPs if needed.
467 m_copydata(m
, sizeof(struct ip
) +
468 offsetof(struct ip
, ip_off
),
469 sizeof(u_int16_t
), (caddr_t
) &ipo
->ip_off
);
470 ipo
->ip_off
= ntohs(ipo
->ip_off
);
471 ipo
->ip_off
&= ~(IP_DF
| IP_MF
| IP_OFFMASK
);
472 ipo
->ip_off
= htons(ipo
->ip_off
);
475 else if (tp
== (IPV6_VERSION
>> 4)) {
478 /* Save ECN notification. */
479 m_copydata(m
, sizeof(struct ip
) +
480 offsetof(struct ip6_hdr
, ip6_flow
),
481 sizeof(u_int32_t
), (caddr_t
) &itos32
);
482 itos
= ntohl(itos32
) >> 20;
483 ipo
->ip_p
= IPPROTO_IPV6
;
492 ip_ecn_ingress(ECN_ALLOWED
, &otos
, &itos
);
499 if (IN6_IS_ADDR_UNSPECIFIED(&saidx
->dst
.sin6
.sin6_addr
) ||
500 saidx
->src
.sa
.sa_family
!= AF_INET6
||
501 IN6_IS_ADDR_UNSPECIFIED(&saidx
->src
.sin6
.sin6_addr
)) {
502 DPRINTF(("ipip_output: unspecified tunnel endpoint "
503 "address in SA %s/%08lx\n",
504 ipsec_address(&saidx
->dst
),
505 (u_long
) ntohl(sav
->spi
)));
506 ipipstat
.ipips_unspec
++;
511 /* scoped address handling */
512 ip6
= mtod(m
, struct ip6_hdr
*);
513 if (IN6_IS_SCOPE_LINKLOCAL(&ip6
->ip6_src
))
514 ip6
->ip6_src
.s6_addr16
[1] = 0;
515 if (IN6_IS_SCOPE_LINKLOCAL(&ip6
->ip6_dst
))
516 ip6
->ip6_dst
.s6_addr16
[1] = 0;
518 M_PREPEND(m
, sizeof(struct ip6_hdr
), MB_DONTWAIT
);
520 DPRINTF(("ipip_output: M_PREPEND failed\n"));
521 ipipstat
.ipips_hdrops
++;
527 /* Initialize IPv6 header */
528 ip6o
= mtod(m
, struct ip6_hdr
*);
530 ip6o
->ip6_vfc
&= ~IPV6_VERSION_MASK
;
531 ip6o
->ip6_vfc
|= IPV6_VERSION
;
532 ip6o
->ip6_plen
= htons(m
->m_pkthdr
.len
);
533 ip6o
->ip6_hlim
= ip_defttl
;
534 ip6o
->ip6_dst
= saidx
->dst
.sin6
.sin6_addr
;
535 ip6o
->ip6_src
= saidx
->src
.sin6
.sin6_addr
;
538 if (tp
== IPVERSION
) {
539 /* Save ECN notification */
540 m_copydata(m
, sizeof(struct ip6_hdr
) +
541 offsetof(struct ip
, ip_tos
), sizeof(u_int8_t
),
544 /* This is really IPVERSION. */
545 ip6o
->ip6_nxt
= IPPROTO_IPIP
;
548 if (tp
== (IPV6_VERSION
>> 4)) {
551 /* Save ECN notification. */
552 m_copydata(m
, sizeof(struct ip6_hdr
) +
553 offsetof(struct ip6_hdr
, ip6_flow
),
554 sizeof(u_int32_t
), (caddr_t
) &itos32
);
555 itos
= ntohl(itos32
) >> 20;
557 ip6o
->ip6_nxt
= IPPROTO_IPV6
;
563 ip_ecn_ingress(ECN_ALLOWED
, &otos
, &itos
);
564 ip6o
->ip6_flow
|= htonl((u_int32_t
) otos
<< 20);
570 DPRINTF(("ipip_output: unsupported protocol family %u\n",
571 saidx
->dst
.sa
.sa_family
));
572 ipipstat
.ipips_family
++;
573 error
= EAFNOSUPPORT
; /* XXX diffs from openbsd */
577 ipipstat
.ipips_opackets
++;
581 if (saidx
->dst
.sa
.sa_family
== AF_INET
) {
583 if (sav
->tdb_xform
->xf_type
== XF_IP4
)
584 tdb
->tdb_cur_bytes
+=
585 m
->m_pkthdr
.len
- sizeof(struct ip
);
587 ipipstat
.ipips_obytes
+= m
->m_pkthdr
.len
- sizeof(struct ip
);
592 if (saidx
->dst
.sa
.sa_family
== AF_INET6
) {
594 if (sav
->tdb_xform
->xf_type
== XF_IP4
)
595 tdb
->tdb_cur_bytes
+=
596 m
->m_pkthdr
.len
- sizeof(struct ip6_hdr
);
598 ipipstat
.ipips_obytes
+=
599 m
->m_pkthdr
.len
- sizeof(struct ip6_hdr
);
606 m_freem(m
), *mp
= NULL
;
612 ipe4_init(struct secasvar
*sav
, struct xformsw
*xsp
)
614 sav
->tdb_xform
= xsp
;
619 ipe4_zeroize(struct secasvar
*sav
)
621 sav
->tdb_xform
= NULL
;
626 ipe4_input(struct mbuf
*m
, struct secasvar
*sav
, int skip
, int protoff
)
628 /* This is a rather serious mistake, so no conditional printing. */
629 kprintf("ipe4_input: should never be called\n");
635 static struct xformsw ipe4_xformsw
= {
636 XF_IP4
, 0, "IPv4 Simple Encapsulation",
637 ipe4_init
, ipe4_zeroize
, ipe4_input
, ipip_output
,
640 extern struct domain inetdomain
;
641 static struct protosw ipe4_protosw
[] = {
642 { SOCK_RAW
, &inetdomain
, IPPROTO_IPV4
, PR_ATOMIC
|PR_ADDR
|PR_LASTHDR
,
650 { SOCK_RAW
, &inetdomain
, IPPROTO_IPV6
, PR_ATOMIC
|PR_ADDR
|PR_LASTHDR
,
661 * Check the encapsulated packet to see if we want it
664 ipe4_encapcheck(const struct mbuf
*m
, int off
, int proto
, void *arg
)
667 * Only take packets coming from IPSEC tunnels; the rest
668 * must be handled by the gif tunnel code. Note that we
669 * also return a minimum priority when we want the packet
670 * so any explicit gif tunnels take precedence.
672 return ((m
->m_flags
& M_IPSEC
) != 0 ? 1 : 0);
678 xform_register(&ipe4_xformsw
);
679 /* attach to encapsulation framework */
680 /* XXX save return cookie for detach on module remove */
681 encap_attach_func(AF_INET
, -1,
682 ipe4_encapcheck
, (struct protosw
*) &ipe4_protosw
[0], NULL
);
684 encap_attach_func(AF_INET6
, -1,
685 ipe4_encapcheck
, (struct protosw
*) &ipe4_protosw
[1], NULL
);
688 SYSINIT(ipe4_xform_init
, SI_SUB_PROTO_DOMAIN
, SI_ORDER_MIDDLE
, ipe4_attach
, NULL
);
689 #endif /* FAST_IPSEC */