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/* $NetBSD: ip_gre.c,v 1.21 2002/08/14 00:23:30 itojun Exp $ */
/* $FreeBSD$ */
/*
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Heiko W.Rupp <hwr@pilhuhn.de>
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* deencapsulate tunneled packets and send them on
* output half is in net/if_gre.[ch]
* This currently handles IPPROTO_GRE, IPPROTO_MOBILE
*/
#include "opt_inet.h"
#include "opt_ns.h"
#include "opt_atalk.h"
#include "bpf.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/raw_cb.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_gre.h>
#include <machine/in_cksum.h>
#else
#error ip_gre input without IP?
#endif
#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/at_extern.h>
#endif
/* Needs IP headers. */
#include <net/if_gre.h>
#include <machine/stdarg.h>
#if 1
void gre_inet_ntoa(struct in_addr in); /* XXX */
#endif
static struct gre_softc *gre_lookup __P((struct mbuf *, u_int8_t));
static int gre_input2 __P((struct mbuf *, int, u_char));
/*
* De-encapsulate a packet and feed it back through ip input (this
* routine is called whenever IP gets a packet with proto type
* IPPROTO_GRE and a local destination address).
* This really is simple
*/
void
#if __STDC__
gre_input(struct mbuf *m, ...)
#else
gre_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
int off, ret, proto;
va_list ap;
va_start(ap, m);
off = va_arg(ap, int);
va_end(ap);
proto = (mtod(m, struct ip *))->ip_p;
ret = gre_input2(m, off, proto);
/*
* ret == 0 : packet not processed, meaning that
* no matching tunnel that is up is found.
* we inject it to raw ip socket to see if anyone picks it up.
*/
if (ret == 0)
rip_input(m, off);
}
/*
* decapsulate.
* Does the real work and is called from gre_input() (above)
* returns 0 if packet is not yet processed
* and 1 if it needs no further processing
* proto is the protocol number of the "calling" foo_input()
* routine.
*/
static int
gre_input2(struct mbuf *m ,int hlen, u_char proto)
{
struct greip *gip = mtod(m, struct greip *);
int s;
struct ifqueue *ifq;
struct gre_softc *sc;
u_short flags;
if ((sc = gre_lookup(m, proto)) == NULL) {
/* No matching tunnel or tunnel is down. */
return (0);
}
sc->sc_if.if_ipackets++;
sc->sc_if.if_ibytes += m->m_pkthdr.len;
switch (proto) {
case IPPROTO_GRE:
hlen += sizeof (struct gre_h);
/* process GRE flags as packet can be of variable len */
flags = ntohs(gip->gi_flags);
/* Checksum & Offset are present */
if ((flags & GRE_CP) | (flags & GRE_RP))
hlen += 4;
/* We don't support routing fields (variable length) */
if (flags & GRE_RP)
return(0);
if (flags & GRE_KP)
hlen += 4;
if (flags & GRE_SP)
hlen +=4;
switch (ntohs(gip->gi_ptype)) { /* ethertypes */
case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */
ifq = &ipintrq; /* we are in ip_input */
break;
#ifdef NS
case ETHERTYPE_NS:
ifq = &nsintrq;
schednetisr(NETISR_NS);
break;
#endif
#ifdef NETATALK
case ETHERTYPE_ATALK:
ifq = &atintrq1;
schednetisr(NETISR_ATALK);
break;
#endif
case ETHERTYPE_IPV6:
/* FALLTHROUGH */
default: /* others not yet supported */
return(0);
}
break;
default:
/* others not yet supported */
return(0);
}
m->m_data += hlen;
m->m_len -= hlen;
m->m_pkthdr.len -= hlen;
#if NBPF > 0
if (sc->sc_if.if_bpf) {
struct mbuf m0;
u_int32_t af = AF_INET;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)⁡
bpf_mtap(&(sc->sc_if), &m0);
}
#endif /*NBPF > 0*/
m->m_pkthdr.rcvif = &sc->sc_if;
s = splnet(); /* possible */
if (_IF_QFULL(ifq)) {
_IF_DROP(ifq);
m_freem(m);
} else {
IF_ENQUEUE(ifq,m);
}
splx(s);
return(1); /* packet is done, no further processing needed */
}
/*
* input routine for IPPRPOTO_MOBILE
* This is a little bit diffrent from the other modes, as the
* encapsulating header was not prepended, but instead inserted
* between IP header and payload
*/
void
#if __STDC__
gre_mobile_input(struct mbuf *m, ...)
#else
gre_mobile_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
struct ip *ip = mtod(m, struct ip *);
struct mobip_h *mip = mtod(m, struct mobip_h *);
struct ifqueue *ifq;
struct gre_softc *sc;
int hlen,s;
va_list ap;
u_char osrc = 0;
int msiz;
va_start(ap,m);
hlen = va_arg(ap, int);
va_end(ap);
if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
/* No matching tunnel or tunnel is down. */
m_freem(m);
return;
}
sc->sc_if.if_ipackets++;
sc->sc_if.if_ibytes += m->m_pkthdr.len;
if(ntohs(mip->mh.proto) & MOB_H_SBIT) {
osrc = 1;
msiz = MOB_H_SIZ_L;
mip->mi.ip_src.s_addr = mip->mh.osrc;
} else {
msiz = MOB_H_SIZ_S;
}
mip->mi.ip_dst.s_addr = mip->mh.odst;
mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
if (gre_in_cksum((u_short*)&mip->mh,msiz) != 0) {
m_freem(m);
return;
}
bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) +
(ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2));
m->m_len -= msiz;
m->m_pkthdr.len -= msiz;
/*
* On FreeBSD, rip_input() supplies us with ip->ip_len
* already converted into host byteorder and also decreases
* it by the lengh of IP header, however, ip_input() expects
* that this field is in the original format (network byteorder
* and full size of IP packet), so that adjust accordingly.
*/
ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
#if NBPF > 0
if (sc->sc_if.if_bpf) {
struct mbuf m0;
u_int af = AF_INET;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)⁡
bpf_mtap(&(sc->sc_if), &m0);
}
#endif /*NBPFILTER > 0*/
m->m_pkthdr.rcvif = &sc->sc_if;
ifq = &ipintrq;
s = splnet(); /* possible */
if (_IF_QFULL(ifq)) {
_IF_DROP(ifq);
m_freem(m);
} else {
IF_ENQUEUE(ifq,m);
}
splx(s);
}
/*
* Find the gre interface associated with our src/dst/proto set.
*/
static struct gre_softc *
gre_lookup(m, proto)
struct mbuf *m;
u_int8_t proto;
{
struct ip *ip = mtod(m, struct ip *);
struct gre_softc *sc;
for (sc = LIST_FIRST(&gre_softc_list); sc != NULL;
sc = LIST_NEXT(sc, sc_list)) {
if ((sc->g_dst.s_addr == ip->ip_src.s_addr) &&
(sc->g_src.s_addr == ip->ip_dst.s_addr) &&
(sc->g_proto == proto) &&
((sc->sc_if.if_flags & IFF_UP) != 0))
return (sc);
}
return (NULL);
}
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