freebsd-dev/sys/netinet6/in6_gif.c
Andrew Thompson 73ff045c57 Add RFC 3378 EtherIP support. This change makes it possible to add gif
interfaces to bridges, which will then send and receive IP protocol 97 packets.
Packets are Ethernet frames with an EtherIP header prepended.

Obtained from:	NetBSD
MFC after:	2 weeks
2005-12-21 21:29:45 +00:00

434 lines
10 KiB
C

/* $FreeBSD$ */
/* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */
/*-
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/protosw.h>
#include <sys/malloc.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <netinet/ip.h>
#endif
#include <netinet/ip_encap.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_gif.h>
#include <netinet6/in6_var.h>
#endif
#include <netinet6/ip6protosw.h>
#include <netinet/ip_ecn.h>
#ifdef INET6
#include <netinet6/ip6_ecn.h>
#endif
#include <net/if_gif.h>
#include <net/net_osdep.h>
static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
struct ifnet *);
extern struct domain inet6domain;
struct ip6protosw in6_gif_protosw =
{ SOCK_RAW, &inet6domain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
in6_gif_input, rip6_output, 0, rip6_ctloutput,
0,
0, 0, 0, 0,
&rip6_usrreqs
};
int
in6_gif_output(ifp, family, m)
struct ifnet *ifp;
int family; /* family of the packet to be encapsulate. */
struct mbuf *m;
{
struct gif_softc *sc = ifp->if_softc;
struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
struct ip6_hdr *ip6;
struct etherip_header eiphdr;
int proto, error;
u_int8_t itos, otos;
if (sin6_src == NULL || sin6_dst == NULL ||
sin6_src->sin6_family != AF_INET6 ||
sin6_dst->sin6_family != AF_INET6) {
m_freem(m);
return EAFNOSUPPORT;
}
switch (family) {
#ifdef INET
case AF_INET:
{
struct ip *ip;
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m)
return ENOBUFS;
}
ip = mtod(m, struct ip *);
itos = ip->ip_tos;
break;
}
#endif
#ifdef INET6
case AF_INET6:
{
struct ip6_hdr *ip6;
proto = IPPROTO_IPV6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m)
return ENOBUFS;
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
#endif
case AF_LINK:
proto = IPPROTO_ETHERIP;
eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
eiphdr.eip_pad = 0;
/* prepend Ethernet-in-IP header */
M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
if (m && m->m_len < sizeof(struct etherip_header))
m = m_pullup(m, sizeof(struct etherip_header));
if (m == NULL)
return ENOBUFS;
bcopy(&eiphdr, mtod(m, struct etherip_header *),
sizeof(struct etherip_header));
break;
default:
#ifdef DEBUG
printf("in6_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
/* prepend new IP header */
M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
if (m && m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL) {
printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
return ENOBUFS;
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
ip6->ip6_nxt = proto;
ip6->ip6_hlim = ip6_gif_hlim;
ip6->ip6_src = sin6_src->sin6_addr;
/* bidirectional configured tunnel mode */
if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
ip6->ip6_dst = sin6_dst->sin6_addr;
else {
m_freem(m);
return ENETUNREACH;
}
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
&otos, &itos);
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
if (dst->sin6_family != sin6_dst->sin6_family ||
!IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
/* cache route doesn't match */
bzero(dst, sizeof(*dst));
dst->sin6_family = sin6_dst->sin6_family;
dst->sin6_len = sizeof(struct sockaddr_in6);
dst->sin6_addr = sin6_dst->sin6_addr;
if (sc->gif_ro6.ro_rt) {
RTFREE(sc->gif_ro6.ro_rt);
sc->gif_ro6.ro_rt = NULL;
}
#if 0
GIF2IFP(sc)->if_mtu = GIF_MTU;
#endif
}
if (sc->gif_ro6.ro_rt == NULL) {
rtalloc((struct route *)&sc->gif_ro6);
if (sc->gif_ro6.ro_rt == NULL) {
m_freem(m);
return ENETUNREACH;
}
/* if it constitutes infinite encapsulation, punt. */
if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
m_freem(m);
return ENETUNREACH; /*XXX*/
}
#if 0
ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
- sizeof(struct ip6_hdr);
#endif
}
#ifdef IPV6_MINMTU
/*
* force fragmentation to minimum MTU, to avoid path MTU discovery.
* it is too painful to ask for resend of inner packet, to achieve
* path MTU discovery for encapsulated packets.
*/
error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
#else
error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
#endif
if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
sc->gif_ro6.ro_rt != NULL) {
RTFREE(sc->gif_ro6.ro_rt);
sc->gif_ro6.ro_rt = NULL;
}
return (error);
}
int
in6_gif_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto;
{
struct mbuf *m = *mp;
struct ifnet *gifp = NULL;
struct gif_softc *sc;
struct ip6_hdr *ip6;
int af = 0;
u_int32_t otos;
ip6 = mtod(m, struct ip6_hdr *);
sc = (struct gif_softc *)encap_getarg(m);
if (sc == NULL) {
m_freem(m);
ip6stat.ip6s_nogif++;
return IPPROTO_DONE;
}
gifp = GIF2IFP(sc);
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
ip6stat.ip6s_nogif++;
return IPPROTO_DONE;
}
otos = ip6->ip6_flow;
m_adj(m, *offp);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
{
struct ip *ip;
u_int8_t otos8;
af = AF_INET;
otos8 = (ntohl(otos) >> 20) & 0xff;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m)
return IPPROTO_DONE;
}
ip = mtod(m, struct ip *);
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos8, &ip->ip_tos) == 0) {
m_freem(m);
return IPPROTO_DONE;
}
break;
}
#endif /* INET */
#ifdef INET6
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
af = AF_INET6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m)
return IPPROTO_DONE;
}
ip6 = mtod(m, struct ip6_hdr *);
if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &ip6->ip6_flow) == 0) {
m_freem(m);
return IPPROTO_DONE;
}
break;
}
#endif
case IPPROTO_ETHERIP:
af = AF_LINK;
break;
default:
ip6stat.ip6s_nogif++;
m_freem(m);
return IPPROTO_DONE;
}
gif_input(m, af, gifp);
return IPPROTO_DONE;
}
/*
* validate outer address.
*/
static int
gif_validate6(ip6, sc, ifp)
const struct ip6_hdr *ip6;
struct gif_softc *sc;
struct ifnet *ifp;
{
struct sockaddr_in6 *src, *dst;
src = (struct sockaddr_in6 *)sc->gif_psrc;
dst = (struct sockaddr_in6 *)sc->gif_pdst;
/*
* Check for address match. Note that the check is for an incoming
* packet. We should compare the *source* address in our configuration
* and the *destination* address of the packet, and vice versa.
*/
if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
!IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
return 0;
/* martian filters on outer source - done in ip6_input */
/* ingress filters on outer source */
if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
struct sockaddr_in6 sin6;
struct rtentry *rt;
bzero(&sin6, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_addr = ip6->ip6_src;
sin6.sin6_scope_id = 0; /* XXX */
rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
if (!rt || rt->rt_ifp != ifp) {
#if 0
log(LOG_WARNING, "%s: packet from %s dropped "
"due to ingress filter\n", if_name(GIF2IFP(sc)),
ip6_sprintf(&sin6.sin6_addr));
#endif
if (rt)
rtfree(rt);
return 0;
}
rtfree(rt);
}
return 128 * 2;
}
/*
* we know that we are in IFF_UP, outer address available, and outer family
* matched the physical addr family. see gif_encapcheck().
* sanity check for arg should have been done in the caller.
*/
int
gif_encapcheck6(m, off, proto, arg)
const struct mbuf *m;
int off;
int proto;
void *arg;
{
struct ip6_hdr ip6;
struct gif_softc *sc;
struct ifnet *ifp;
/* sanity check done in caller */
sc = (struct gif_softc *)arg;
/* LINTED const cast */
m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
return gif_validate6(&ip6, sc, ifp);
}
int
in6_gif_attach(sc)
struct gif_softc *sc;
{
sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
(struct protosw *)&in6_gif_protosw, sc);
if (sc->encap_cookie6 == NULL)
return EEXIST;
return 0;
}
int
in6_gif_detach(sc)
struct gif_softc *sc;
{
int error;
error = encap_detach(sc->encap_cookie6);
if (error == 0)
sc->encap_cookie6 = NULL;
return error;
}