freebsd-skq/sys/netinet/in_gif.c
bz e15f804c7b Update packet filter (pf) code to OpenBSD 4.5.
You need to update userland (world and ports) tools
to be in sync with the kernel.

Submitted by:	mlaier
Submitted by:	eri
2011-06-28 11:57:25 +00:00

470 lines
11 KiB
C

/* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mrouting.h"
#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/kernel.h>
#include <sys/sysctl.h>
#include <sys/protosw.h>
#include <sys/malloc.h>
#include <net/if.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_gif.h>
#include <netinet/in_var.h>
#include <netinet/ip_encap.h>
#include <netinet/ip_ecn.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#ifdef MROUTING
#include <netinet/ip_mroute.h>
#endif /* MROUTING */
#include <net/if_gif.h>
static int gif_validate4(const struct ip *, struct gif_softc *,
struct ifnet *);
extern struct domain inetdomain;
struct protosw in_gif_protosw = {
.pr_type = SOCK_RAW,
.pr_domain = &inetdomain,
.pr_protocol = 0/* IPPROTO_IPV[46] */,
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_input = in_gif_input,
.pr_output = (pr_output_t*)rip_output,
.pr_ctloutput = rip_ctloutput,
.pr_usrreqs = &rip_usrreqs
};
VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL;
#define V_ip_gif_ttl VNET(ip_gif_ttl)
SYSCTL_VNET_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
&VNET_NAME(ip_gif_ttl), 0, "");
int
in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
{
struct gif_softc *sc = ifp->if_softc;
struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
struct ip iphdr; /* capsule IP header, host byte ordered */
struct etherip_header eiphdr;
int error, len, proto;
u_int8_t tos;
GIF_LOCK_ASSERT(sc);
if (sin_src == NULL || sin_dst == NULL ||
sin_src->sin_family != AF_INET ||
sin_dst->sin_family != AF_INET) {
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 *);
tos = ip->ip_tos;
break;
}
#endif /* INET */
#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 *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
#endif /* INET6 */
case AF_LINK:
proto = IPPROTO_ETHERIP;
/*
* GIF_SEND_REVETHIP (disabled by default) intentionally
* sends an EtherIP packet with revered version field in
* the header. This is a knob for backward compatibility
* with FreeBSD 7.2R or prior.
*/
if ((sc->gif_options & GIF_SEND_REVETHIP)) {
eiphdr.eip_ver = 0;
eiphdr.eip_resvl = ETHERIP_VERSION;
eiphdr.eip_resvh = 0;
} else {
eiphdr.eip_ver = ETHERIP_VERSION;
eiphdr.eip_resvl = 0;
eiphdr.eip_resvh = 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("in_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
bzero(&iphdr, sizeof(iphdr));
iphdr.ip_src = sin_src->sin_addr;
/* bidirectional configured tunnel mode */
if (sin_dst->sin_addr.s_addr != INADDR_ANY)
iphdr.ip_dst = sin_dst->sin_addr;
else {
m_freem(m);
return ENETUNREACH;
}
iphdr.ip_p = proto;
/* version will be set in ip_output() */
iphdr.ip_ttl = V_ip_gif_ttl;
iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
&iphdr.ip_tos, &tos);
/* prepend new IP header */
len = sizeof(struct ip);
#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 in_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,
("in_gif_output: unexpected misalignment"));
m->m_data += len;
m->m_len -= ETHERIP_ALIGN;
}
#endif
bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
M_SETFIB(m, sc->gif_fibnum);
if (dst->sin_family != sin_dst->sin_family ||
dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
/* cache route doesn't match */
bzero(dst, sizeof(*dst));
dst->sin_family = sin_dst->sin_family;
dst->sin_len = sizeof(struct sockaddr_in);
dst->sin_addr = sin_dst->sin_addr;
if (sc->gif_ro.ro_rt) {
RTFREE(sc->gif_ro.ro_rt);
sc->gif_ro.ro_rt = NULL;
}
#if 0
GIF2IFP(sc)->if_mtu = GIF_MTU;
#endif
}
if (sc->gif_ro.ro_rt == NULL) {
in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum);
if (sc->gif_ro.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_ro.ro_rt->rt_ifp->if_mtu
- sizeof(struct ip);
#endif
}
m_addr_changed(m);
error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
sc->gif_ro.ro_rt != NULL) {
RTFREE(sc->gif_ro.ro_rt);
sc->gif_ro.ro_rt = NULL;
}
return (error);
}
void
in_gif_input(struct mbuf *m, int off)
{
struct ifnet *gifp = NULL;
struct gif_softc *sc;
struct ip *ip;
int af;
u_int8_t otos;
int proto;
ip = mtod(m, struct ip *);
proto = ip->ip_p;
sc = (struct gif_softc *)encap_getarg(m);
if (sc == NULL) {
m_freem(m);
KMOD_IPSTAT_INC(ips_nogif);
return;
}
gifp = GIF2IFP(sc);
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
KMOD_IPSTAT_INC(ips_nogif);
return;
}
otos = ip->ip_tos;
m_adj(m, off);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
{
struct ip *ip;
af = AF_INET;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m)
return;
}
ip = mtod(m, struct ip *);
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &ip->ip_tos) == 0) {
m_freem(m);
return;
}
break;
}
#endif
#ifdef INET6
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
u_int8_t itos, oitos;
af = AF_INET6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m)
return;
}
ip6 = mtod(m, struct ip6_hdr *);
itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &itos) == 0) {
m_freem(m);
return;
}
if (itos != oitos) {
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
}
break;
}
#endif /* INET6 */
case IPPROTO_ETHERIP:
af = AF_LINK;
break;
default:
KMOD_IPSTAT_INC(ips_nogif);
m_freem(m);
return;
}
gif_input(m, af, gifp);
return;
}
/*
* validate outer address.
*/
static int
gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
{
struct sockaddr_in *src, *dst;
struct in_ifaddr *ia4;
src = (struct sockaddr_in *)sc->gif_psrc;
dst = (struct sockaddr_in *)sc->gif_pdst;
/* check for address match */
if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
dst->sin_addr.s_addr != ip->ip_src.s_addr)
return 0;
/* martian filters on outer source - NOT done in ip_input! */
if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
return 0;
switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
case 0: case 127: case 255:
return 0;
}
/* reject packets with broadcast on source */
/* XXXRW: should use hash lists? */
IN_IFADDR_RLOCK();
TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
continue;
if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
IN_IFADDR_RUNLOCK();
return 0;
}
}
IN_IFADDR_RUNLOCK();
/* ingress filters on outer source */
if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
struct sockaddr_in sin;
struct rtentry *rt;
bzero(&sin, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_addr = ip->ip_src;
/* XXX MRT check for the interface we would use on output */
rt = in_rtalloc1((struct sockaddr *)&sin, 0,
0UL, sc->gif_fibnum);
if (!rt || rt->rt_ifp != ifp) {
#if 0
log(LOG_WARNING, "%s: packet from 0x%x dropped "
"due to ingress filter\n", if_name(GIF2IFP(sc)),
(u_int32_t)ntohl(sin.sin_addr.s_addr));
#endif
if (rt)
RTFREE_LOCKED(rt);
return 0;
}
RTFREE_LOCKED(rt);
}
return 32 * 2;
}
/*
* we know that we are in IFF_UP, outer address available, and outer family
* matched the physical addr family. see gif_encapcheck().
*/
int
gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
{
struct ip ip;
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(ip), (caddr_t)&ip);
ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
return gif_validate4(&ip, sc, ifp);
}
int
in_gif_attach(struct gif_softc *sc)
{
sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
&in_gif_protosw, sc);
if (sc->encap_cookie4 == NULL)
return EEXIST;
return 0;
}
int
in_gif_detach(struct gif_softc *sc)
{
int error;
error = encap_detach(sc->encap_cookie4);
if (error == 0)
sc->encap_cookie4 = NULL;
return error;
}