NetBSD/sys/netinet/ip_gre.c

271 lines
6.9 KiB
C

/* $NetBSD: ip_gre.c,v 1.42 2006/09/07 02:40:33 dogcow Exp $ */
/*
* 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>
*
* IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ip_gre.c,v 1.42 2006/09/07 02:40:33 dogcow Exp $");
#include "gre.h"
#if NGRE > 0
#include "opt_inet.h"
#include "opt_atalk.h"
#include "bpfilter.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/ioctl.h>
#include <sys/syslog.h>
#include <net/bpf.h>
#include <net/ethertypes.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>
#else
#error ip_gre input without IP?
#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
struct gre_softc *gre_lookup(struct mbuf *, u_int8_t);
int gre_input2(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
gre_input(struct mbuf *m, ...)
{
int off, ret, proto;
va_list ap;
va_start(ap, m);
off = va_arg(ap, int);
proto = va_arg(ap, int);
va_end(ap);
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, proto);
}
/*
* 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.
*/
int
gre_input2(struct mbuf *m, int hlen, u_char proto)
{
const struct greip *gip;
struct gre_softc *sc;
if ((sc = gre_lookup(m, proto)) == NULL) {
/* No matching tunnel or tunnel is down. */
return (0);
}
if (m->m_len < sizeof(*gip)) {
m = m_pullup(m, sizeof(*gip));
if (m == NULL)
return (ENOBUFS);
}
gip = mtod(m, const struct greip *);
return gre_input3(sc, m, hlen, proto, &gip->gi_g);
}
/*
* input routine for IPPRPOTO_MOBILE
* This is a little bit different from the other modes, as the
* encapsulating header was not prepended, but instead inserted
* between IP header and payload
*/
void
gre_mobile_input(struct mbuf *m, ...)
{
struct ip *ip;
struct mobip_h *mip;
struct ifqueue *ifq;
struct gre_softc *sc;
uint8_t *hdr;
int hlen, s;
va_list ap;
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;
}
if (M_UNWRITABLE(m, sizeof(*mip))) {
m = m_pullup(m, sizeof(*mip));
if (m == NULL)
return;
}
ip = mtod(m, struct ip *);
/* XXX what if there are IP options? */
mip = mtod(m, struct mobip_h *);
sc->sc_if.if_ipackets++;
sc->sc_if.if_ibytes += m->m_pkthdr.len;
if (ntohs(mip->mh.proto) & MOB_H_SBIT) {
msiz = MOB_H_SIZ_L;
mip->mi.ip_src.s_addr = mip->mh.osrc;
} else
msiz = MOB_H_SIZ_S;
if (M_UNWRITABLE(m, hlen + msiz)) {
m = m_pullup(m, hlen + msiz);
if (m == NULL)
return;
ip = mtod(m, struct ip *);
mip = mtod(m, struct mobip_h *);
}
mip->mi.ip_dst.s_addr = mip->mh.odst;
mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
if (gre_in_cksum((u_int16_t *)&mip->mh, msiz) != 0) {
m_freem(m);
return;
}
hdr = mtod(m, uint8_t *);
memmove(hdr + hlen, hdr + hlen + msiz, m->m_len - msiz - hlen);
m->m_len -= msiz;
ip->ip_len = htons(ntohs(ip->ip_len) - msiz);
m->m_pkthdr.len -= msiz;
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, hlen);
#if NBPFILTER > 0
if (sc->sc_if.if_bpf != NULL)
bpf_mtap_af(sc->sc_if.if_bpf, AF_INET, m);
#endif /*NBPFILTER > 0*/
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.
*/
struct gre_softc *
gre_lookup(struct mbuf *m, u_int8_t proto)
{
const struct ip *ip = mtod(m, const 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);
}
#endif /* if NGRE > 0 */