freebsd-dev/sys/netinet6/in6_gif.c
Marius Strobl c89c8a1029 On architectures with strict alignment requirements compensate
the misalignment of the IP header that prepending the EtherIP
header might have caused.

PR:		131921
MFC after:	1 week
2009-03-07 19:08:58 +00:00

446 lines
11 KiB
C

/*-
* 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.
*
* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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 <sys/vimage.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>
#include <netinet6/vinet6.h>
#endif
#include <net/if_gif.h>
static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
struct ifnet *);
extern struct domain inet6domain;
struct ip6protosw in6_gif_protosw = {
.pr_type = SOCK_RAW,
.pr_domain = &inet6domain,
.pr_protocol = 0, /* IPPROTO_IPV[46] */
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_input = in6_gif_input,
.pr_output = rip6_output,
.pr_ctloutput = rip6_ctloutput,
.pr_usrreqs = &rip6_usrreqs
};
int
in6_gif_output(struct ifnet *ifp,
int family, /* family of the packet to be encapsulate */
struct mbuf *m)
{
INIT_VNET_GIF(ifp->if_vnet);
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 error, len, proto;
u_int8_t itos, otos;
GIF_LOCK_ASSERT(sc);
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 */
len = sizeof(struct ip6_hdr);
#ifndef __NO_STRICT_ALIGNMENT
if (family == AF_LINK)
len += ETHERIP_ALIGN;
#endif
M_PREPEND(m, len, M_DONTWAIT);
if (m != NULL && m->m_len < len)
m = m_pullup(m, len);
if (m == NULL) {
printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
return ENOBUFS;
}
#ifndef __NO_STRICT_ALIGNMENT
if (family == AF_LINK) {
len = mtod(m, vm_offset_t) & 3;
KASSERT(len == 0 || len == ETHERIP_ALIGN,
("in6_gif_output: unexpected misalignment"));
m->m_data += len;
m->m_len -= ETHERIP_ALIGN;
}
#endif
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 = V_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(struct mbuf **mp, int *offp, int proto)
{
INIT_VNET_INET6(curvnet);
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);
V_ip6stat.ip6s_nogif++;
return IPPROTO_DONE;
}
gifp = GIF2IFP(sc);
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
V_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:
V_ip6stat.ip6s_nogif++;
m_freem(m);
return IPPROTO_DONE;
}
gif_input(m, af, gifp);
return IPPROTO_DONE;
}
/*
* validate outer address.
*/
static int
gif_validate6(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
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_WARNING, "%s: packet from %s dropped "
"due to ingress filter\n", if_name(GIF2IFP(sc)),
ip6_sprintf(ip6buf, &sin6.sin6_addr));
#endif
if (rt)
RTFREE_LOCKED(rt);
return 0;
}
RTFREE_LOCKED(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(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(struct gif_softc *sc)
{
sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
(void *)&in6_gif_protosw, sc);
if (sc->encap_cookie6 == NULL)
return EEXIST;
return 0;
}
int
in6_gif_detach(struct gif_softc *sc)
{
int error;
error = encap_detach(sc->encap_cookie6);
if (error == 0)
sc->encap_cookie6 = NULL;
return error;
}