File: [local] / sys / netinet / ip_gre.c (download)
Revision 1.1, Tue Mar 4 16:15:44 2008 UTC (16 years, 6 months ago) by nbrk
Branch point for: MAIN
Initial revision
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/* $OpenBSD: ip_gre.c,v 1.31 2007/05/27 21:20:52 claudio Exp $ */
/* $NetBSD: ip_gre.c,v 1.9 1999/10/25 19:18:11 drochner 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>
*
* 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.
*/
/*
* decapsulate tunneled packets and send them on
* output half is in net/if_gre.[ch]
* This currently handles IPPROTO_GRE, IPPROTO_MOBILE
*/
#include "gre.h"
#if NGRE > 0
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.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 <netinet/if_ether.h>
#else
#error "ip_gre used without inet"
#endif
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/at_extern.h>
#endif
#include "bpfilter.h"
/* Needs IP headers. */
#include <net/if_gre.h>
struct gre_softc *gre_lookup(struct mbuf *, u_int8_t);
int gre_input2(struct mbuf *, int, u_char);
/*
* 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(m , hlen, proto)
struct mbuf *m;
int hlen;
u_char proto;
{
struct greip *gip;
int s;
struct ifqueue *ifq;
struct gre_softc *sc;
u_short flags;
u_int af;
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, struct greip *);
m->m_pkthdr.rcvif = &sc->sc_if;
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 GREPROTO_WCCP:
/* WCCP/GRE:
* So far as I can see (and test) it seems that Cisco's WCCP
* GRE tunnel is precisely a IP-in-GRE tunnel that differs
* only in its protocol number. At least, it works for me.
*
* The Internet Draft can be found if you look for
* draft-forster-wrec-wccp-v1-00.txt
*
* So yes, we're doing a fall-through (unless, of course,
* net.inet.gre.wccp is 0).
*/
if (!gre_wccp)
return (0);
case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */
ifq = &ipintrq; /* we are in ip_input */
af = AF_INET;
break;
#ifdef NETATALK
case ETHERTYPE_AT:
ifq = &atintrq1;
schednetisr(NETISR_ATALK);
af = AF_APPLETALK;
break;
#endif
#ifdef INET6
case ETHERTYPE_IPV6:
ifq = &ip6intrq;
schednetisr(NETISR_IPV6);
af = AF_INET6;
break;
#endif /* INET6 */
default: /* others not yet supported */
return (0);
}
break;
default:
/* others not yet supported */
return (0);
}
if (hlen > m->m_pkthdr.len) {
m_freem(m);
return (EINVAL);
}
m_adj(m, hlen);
#if NBPFILTER > 0
if (sc->sc_if.if_bpf)
bpf_mtap_af(sc->sc_if.if_bpf, af, m, BPF_DIRECTION_IN);
#endif
s = splnet(); /* possible */
IF_INPUT_ENQUEUE(ifq, m);
splx(s);
return (1); /* packet is done, no further processing needed */
}
/*
* Decapsulate 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).
*/
void
gre_input(struct mbuf *m, ...)
{
int hlen, ret;
va_list ap;
va_start(ap, m);
hlen = va_arg(ap, int);
va_end(ap);
if (!gre_allow) {
m_freem(m);
return;
}
ret = gre_input2(m, hlen, IPPROTO_GRE);
/*
* ret == 0: packet not processed, but input from here
* means no matching tunnel that is up is found.
* we inject it to raw ip socket to see if anyone picks it up.
* possible that we received a WCCPv1-style GRE packet
* but we're not set to accept them.
*/
if (!ret)
rip_input(m, hlen, IPPROTO_GRE);
}
/*
* 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
gre_mobile_input(struct mbuf *m, ...)
{
struct ip *ip;
struct mobip_h *mip;
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 (!ip_mobile_allow) {
m_freem(m);
return;
}
if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
/* No matching tunnel or tunnel is down. */
m_freem(m);
return;
}
if (m->m_len < sizeof(*mip)) {
m = m_pullup(m, sizeof(*mip));
if (m == NULL)
return;
}
ip = mtod(m, struct ip *);
mip = mtod(m, struct mobip_h *);
m->m_pkthdr.rcvif = &sc->sc_if;
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;
if (m->m_len < (ip->ip_hl << 2) + msiz) {
m = m_pullup(m, (ip->ip_hl << 2) + 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_short *) &mip->mh, msiz) != 0) {
m_freem(m);
return;
}
bcopy(ip + (ip->ip_hl << 2) + msiz, ip + (ip->ip_hl << 2),
m->m_len - msiz - (ip->ip_hl << 2));
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,(ip->ip_hl << 2));
ifq = &ipintrq;
#if NBPFILTER > 0
if (sc->sc_if.if_bpf)
bpf_mtap_af(sc->sc_if.if_bpf, AF_INET, m, BPF_DIRECTION_IN);
#endif
s = splnet(); /* possible */
IF_INPUT_ENQUEUE(ifq, m);
splx(s);
}
/*
* Find the gre interface associated with our src/dst/proto set.
*/
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;
LIST_FOREACH(sc, &gre_softc_list, 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);
}
int
gre_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
int *name;
u_int namelen;
void *oldp;
size_t *oldlenp;
void *newp;
size_t newlen;
{
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
switch (name[0]) {
case GRECTL_ALLOW:
return (sysctl_int(oldp, oldlenp, newp, newlen, &gre_allow));
case GRECTL_WCCP:
return (sysctl_int(oldp, oldlenp, newp, newlen, &gre_wccp));
default:
return (ENOPROTOOPT);
}
/* NOTREACHED */
}
int
ipmobile_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
int *name;
u_int namelen;
void *oldp;
size_t *oldlenp;
void *newp;
size_t newlen;
{
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
switch (name[0]) {
case MOBILEIPCTL_ALLOW:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ip_mobile_allow));
default:
return (ENOPROTOOPT);
}
/* NOTREACHED */
}
#endif /* if NGRE > 0 */