NetBSD/sys/netinet/in_gif.c

406 lines
9.7 KiB
C

/* $NetBSD: in_gif.c,v 1.62 2012/01/09 14:31:22 liamjfoy Exp $ */
/* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 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>
__KERNEL_RCSID(0, "$NetBSD: in_gif.c,v 1.62 2012/01/09 14:31:22 liamjfoy Exp $");
#include "opt_inet.h"
#include "opt_iso.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/ioctl.h>
#include <sys/syslog.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/route.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
#include <net/if_gif.h>
#include "gif.h"
#include <net/net_osdep.h>
static int gif_validate4(const struct ip *, struct gif_softc *,
struct ifnet *);
#if NGIF > 0
int ip_gif_ttl = GIF_TTL;
#else
int ip_gif_ttl = 0;
#endif
const struct protosw in_gif_protosw =
{ SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
in_gif_input, rip_output, 0, rip_ctloutput,
rip_usrreq,
0, 0, 0, 0,
};
int
in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
{
struct rtentry *rt;
struct gif_softc *sc = ifp->if_softc;
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 */
int proto, error;
u_int8_t tos;
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
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:
{
const struct ip *ip;
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (m == NULL)
return ENOBUFS;
}
ip = mtod(m, const struct ip *);
tos = ip->ip_tos;
break;
}
#endif /* INET */
#ifdef INET6
case AF_INET6:
{
const struct ip6_hdr *ip6;
proto = IPPROTO_IPV6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (m == NULL)
return ENOBUFS;
}
ip6 = mtod(m, const struct ip6_hdr *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
#endif /* INET6 */
#ifdef ISO
case AF_ISO:
proto = IPPROTO_EON;
tos = 0;
break;
#endif
default:
#ifdef DEBUG
printf("in_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
memset(&iphdr, 0, 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 = ip_gif_ttl;
iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip));
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
else
ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
/* prepend new IP header */
M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
/* XXX Is m_pullup really necessary after M_PREPEND? */
if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip)))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL)
return ENOBUFS;
bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0);
if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) {
m_freem(m);
return ENETUNREACH;
}
/* If the route constitutes infinite encapsulation, punt. */
if (rt->rt_ifp == ifp) {
rtcache_free(&sc->gif_ro);
m_freem(m);
return ENETUNREACH; /*XXX*/
}
error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
return (error);
}
void
in_gif_input(struct mbuf *m, ...)
{
int off, proto;
struct ifnet *gifp = NULL;
const struct ip *ip;
va_list ap;
int af;
u_int8_t otos;
va_start(ap, m);
off = va_arg(ap, int);
proto = va_arg(ap, int);
va_end(ap);
ip = mtod(m, const struct ip *);
gifp = (struct ifnet *)encap_getarg(m);
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
ip_statinc(IP_STAT_NOGIF);
return;
}
#ifndef GIF_ENCAPCHECK
if (!gif_validate4(ip, gifp->if_softc, m->m_pkthdr.rcvif)) {
m_freem(m);
ip_statinc(IP_STAT_NOGIF);
return;
}
#endif
otos = ip->ip_tos;
m_adj(m, off);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
{
struct ip *xip;
af = AF_INET;
if (M_UNWRITABLE(m, sizeof(*xip))) {
if ((m = m_pullup(m, sizeof(*xip))) == NULL)
return;
}
xip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos);
break;
}
#endif
#ifdef INET6
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
u_int8_t itos;
af = AF_INET6;
if (M_UNWRITABLE(m, sizeof(*ip6))) {
if ((m = m_pullup(m, sizeof(*ip6))) == NULL)
return;
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &itos);
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
break;
}
#endif /* INET6 */
#ifdef ISO
case IPPROTO_EON:
af = AF_ISO;
break;
#endif
default:
ip_statinc(IP_STAT_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(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 */
TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) {
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)
return 0;
}
/* ingress filters on outer source */
if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
union {
struct sockaddr sa;
struct sockaddr_in sin;
} u;
struct rtentry *rt;
sockaddr_in_init(&u.sin, &ip->ip_src, 0);
rt = rtalloc1(&u.sa, 0);
if (rt == NULL || rt->rt_ifp != ifp) {
#if 0
log(LOG_WARNING, "%s: packet from 0x%x dropped "
"due to ingress filter\n", if_name(&sc->gif_if),
(u_int32_t)ntohl(u.sin.sin_addr.s_addr));
#endif
if (rt != NULL)
rtfree(rt);
return 0;
}
rtfree(rt);
}
return 32 * 2;
}
#ifdef GIF_ENCAPCHECK
/*
* 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(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 = arg;
m_copydata(m, 0, sizeof(ip), &ip);
ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
return gif_validate4(&ip, sc, ifp);
}
#endif
int
in_gif_attach(struct gif_softc *sc)
{
#ifndef GIF_ENCAPCHECK
struct sockaddr_in mask4;
memset(&mask4, 0, sizeof(mask4));
mask4.sin_len = sizeof(struct sockaddr_in);
mask4.sin_addr.s_addr = ~0;
if (!sc->gif_psrc || !sc->gif_pdst)
return EINVAL;
sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc,
(struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4,
(const struct protosw *)&in_gif_protosw, sc);
#else
sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
&in_gif_protosw, sc);
#endif
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;
rtcache_free(&sc->gif_ro);
return error;
}