freebsd-dev/sys/netinet/ip_gre.c
2010-03-01 17:05:46 +00:00

328 lines
8.3 KiB
C

/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun 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.
*
* 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>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_atalk.h"
#include "opt_inet6.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 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(struct mbuf *, u_int8_t);
static struct mbuf *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)
{
int proto;
proto = (mtod(m, struct ip *))->ip_p;
m = gre_input2(m, off, proto);
/*
* If no matching tunnel that is up is found. We inject
* the mbuf to raw ip socket to see if anyone picks it up.
*/
if (m != NULL)
rip_input(m, off);
}
/*
* Decapsulate. Does the real work and is called from gre_input()
* (above). Returns an mbuf back if packet is not yet processed,
* and NULL if it needs no further processing. proto is the protocol
* number of the "calling" foo_input() routine.
*/
static struct mbuf *
gre_input2(struct mbuf *m ,int hlen, u_char proto)
{
struct greip *gip;
int isr;
struct gre_softc *sc;
u_int16_t flags;
u_int32_t af;
if ((sc = gre_lookup(m, proto)) == NULL) {
/* No matching tunnel or tunnel is down. */
return (m);
}
if (m->m_len < sizeof(*gip)) {
m = m_pullup(m, sizeof(*gip));
if (m == NULL)
return (NULL);
}
gip = mtod(m, struct greip *);
GRE2IFP(sc)->if_ipackets++;
GRE2IFP(sc)->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 (m);
if (flags & GRE_KP)
hlen += 4;
if (flags & GRE_SP)
hlen += 4;
switch (ntohs(gip->gi_ptype)) { /* ethertypes */
case WCCP_PROTOCOL_TYPE:
if (sc->wccp_ver == WCCP_V2)
hlen += 4;
/* FALLTHROUGH */
case ETHERTYPE_IP: /* shouldn't need a schednetisr(), */
isr = NETISR_IP;/* as we are in ip_input */
af = AF_INET;
break;
#ifdef INET6
case ETHERTYPE_IPV6:
isr = NETISR_IPV6;
af = AF_INET6;
break;
#endif
#ifdef NETATALK
case ETHERTYPE_ATALK:
isr = NETISR_ATALK1;
af = AF_APPLETALK;
break;
#endif
default:
/* Others not yet supported. */
return (m);
}
break;
default:
/* Others not yet supported. */
return (m);
}
if (hlen > m->m_pkthdr.len) {
m_freem(m);
return (NULL);
}
/* Unlike NetBSD, in FreeBSD m_adj() adjusts m->m_pkthdr.len as well */
m_adj(m, hlen);
if (bpf_peers_present(GRE2IFP(sc)->if_bpf)) {
bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m);
}
m->m_pkthdr.rcvif = GRE2IFP(sc);
netisr_queue(isr, m);
/* Packet is done, no further processing needed. */
return (NULL);
}
/*
* 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, int hlen)
{
struct ip *ip;
struct mobip_h *mip;
struct gre_softc *sc;
int msiz;
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 *);
GRE2IFP(sc)->if_ipackets++;
GRE2IFP(sc)->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->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_int16_t *)&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 (bpf_peers_present(GRE2IFP(sc)->if_bpf)) {
u_int32_t af = AF_INET;
bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m);
}
m->m_pkthdr.rcvif = GRE2IFP(sc);
netisr_queue(NETISR_IP, m);
}
/*
* Find the gre interface associated with our src/dst/proto set.
*
* XXXRW: Need some sort of drain/refcount mechanism so that the softc
* reference remains valid after it's returned from gre_lookup(). Right
* now, I'm thinking it should be reference-counted with a gre_dropref()
* when the caller is done with the softc. This is complicated by how
* to handle destroying the gre softc; probably using a gre_drain() in
* in_gre.c during destroy.
*/
static struct gre_softc *
gre_lookup(struct mbuf *m, u_int8_t proto)
{
struct ip *ip = mtod(m, struct ip *);
struct gre_softc *sc;
mtx_lock(&gre_mtx);
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) &&
((GRE2IFP(sc)->if_flags & IFF_UP) != 0)) {
mtx_unlock(&gre_mtx);
return (sc);
}
}
mtx_unlock(&gre_mtx);
return (NULL);
}