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Add a new gre(4) driver, which could be used to create GRE (RFC1701)

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and MOBILE (RFC2004) IP tunnels.

Obrained from:  NetBSD
This commit is contained in:
Maxim Sobolev 2002-09-06 17:12:50 +00:00
parent 8ab96fd8d0
commit 8e96e13e6a
8 changed files with 1644 additions and 0 deletions
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279
share/man/man4/gre.4 Normal file
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@ -0,0 +1,279 @@
.\" $NetBSD: gre.4,v 1.28 2002/06/10 02:49:35 itojun Exp $
.\" $FreeBSD$
.\"
.\" Copyright 1998 (c) 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 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.
.\"
.Dd June 9, 2002
.Dt GRE 4
.Os
.Sh NAME
.Nm gre
.Nd encapsulating network device
.Sh SYNOPSIS
.Cd pseudo-device gre
.Sh DESCRIPTION
The
.Nm gre
network interface pseudo device encapsulates datagrams
into IP. These encapsulated datagrams are routed to a destination host,
where they are decapsulated and further routed to their final destination.
The
.Dq tunnel
appears to the inner datagrams as one hop.
.Pp
.Nm
interfaces are dynamically created and destroyed with the
.Xr ifconfig 8
.Cm create
and
.Cm destroy
subcommands.
.Pp
This driver currently supports the following modes of operation:
.Bl -tag -width abc
.It GRE encapsulation (IP protocol number 47)
Encapsulated datagrams are
prepended an outer datagram and a GRE header. The GRE header specifies
the type of the encapsulated datagram and thus allows for tunneling other
protocols than IP like e.g. AppleTalk. GRE mode is also the default tunnel
mode on Cisco routers. This is also the default mode of operation of the
.Sy gre Ns Ar X
interfaces.
.It MOBILE encapsulation (IP protocol number 55)
Datagrams are
encapsulated into IP, but with a shorter encapsulation. The original
IP header is modified and the modifications are inserted between the
so modified header and the original payload. Like
.Xr gif 4 ,
only for IP in IP encapsulation.
.El
.Pp
The
.Sy gre Ns Ar X
interfaces support a number of
.Xr ioctl 2 Ns s ,
such as:
.Bl -tag -width aaa
.It GRESADDRS :
Set the IP address of the local tunnel end. This is the source address
set by or displayed by ifconfig for the
.Sy gre Ns Ar X
interface.
.It GRESADDRD :
Set the IP address of the remote tunnel end. This is the destination address
set by or displayed by ifconfig for the
.Sy gre Ns Ar X
interface.
.It GREGADDRS :
Query the IP address that is set for the local tunnel end. This is the
address the encapsulation header carries as local address (i.e. the real
address of the tunnel start point.)
.It GREGADDRD :
Query the IP address that is set for the remote tunnel end. This is the
address the encapsulated packets are sent to (i.e. the real address of
the remote tunnel endpoint.)
.It GRESPROTO :
Set the operation mode to the specified IP protocol value. The
protocol is passed to the interface in (struct ifreq)-\*[Gt]ifr_flags.
The operation mode can also be given as
.Bl -tag -width link0xxx
.It link0
IPPROTO_GRE
.It -link0
IPPROTO_MOBILE
.El
.Pp
to
.Xr ifconfig 8 .
.Pp
The link1 flag is not used to choose encapsulation, but to modify the
internal route search for the remote tunnel endpoint, see the
.Sx BUGS
section below.
.It GREGPROTO :
Query operation mode.
.El
.Pp
Note that the IP addresses of the tunnel endpoints may be the same as the
ones defined with
.Xr ifconfig 8
for the interface (as if IP is encapsulated), but need not be, as e.g. when
encapsulating AppleTalk.
.Sh EXAMPLES
Configuration example:
.Bd -literal
Host X-- Host A ----------------tunnel---------- cisco D------Host E
\\ |
\\ /
+------Host B----------Host C----------+
.Ed
On host A
.Ns ( Nx ) :
.Bd -literal
# route add default B
# ifconfig greN create
# ifconfig greN A D netmask 0xffffffff linkX up
# ifconfig greN tunnel A D
# route add E D
.Ed
On Host D (Cisco):
.Bd -literal
Interface TunnelX
ip unnumbered D ! e.g. address from Ethernet interface
tunnel source D ! e.g. address from Ethernet interface
tunnel destination A
ip route C \*[Lt]some interface and mask\*[Gt]
ip route A mask C
ip route X mask tunnelX
.Ed
OR
On Host D
.Ns ( Nx ) :
.Bd -literal
# route add default C
# ifconfig greN create
# ifconfig greN D A
# ifconfig tunnel greN D A
.Ed
.Pp
If all goes well, you should see packets flowing ;-)
.Pp
If you want to reach Host A over the tunnel (from Host D (Cisco)), then
you have to have an alias on Host A for e.g. the Ethernet interface like:
.Bd -literal
ifconfig \*[Lt]etherif\*[Gt] alias Y
.Ed
and on the cisco
.Bd -literal
ip route Y mask tunnelX
.Ed
.Pp
A similar setup can be used to create a link between two private networks
(for example in the 192.168 subnet) over the Internet:
.Bd -literal
192.168.1.* --- Router A -------tunnel-------- Router B --- 192.168.2.*
\\ /
\\ /
+----- the Internet ------+
.Ed
Assuming router A has the (external) IP address A and the internal address
192.168.1.1, while router B has external address B and internal address
192.168.2.1, the following commands will configure the tunnel:
.Pp
On router A:
.Bd -literal
# ifconfig greN create
# ifconfig greN 192.168.1.1 192.168.2.1 link1
# ifconfig greN tunnel A B
# route add -net 192.168.2 -netmask 255.255.255.0 192.168.2.1
.Ed
.Pp
On router B:
.Bd -literal
# ifconfig greN create
# ifconfig greN 192.168.2.1 192.168.1.1 link1
# ifconfig greN tunnel B A
# route add -net 192.168.1 -netmask 255.255.255.0 192.168.1.1
.Ed
.Pp
Note that this is a safe situation where the link1 flag (as discussed in the
.Sx BUGS
section below) may (and probably should) be set.
.Sh NOTES
The MTU of
.Sy gre Ns Ar X
interfaces is set to 1476 by default to match the value used by Cisco routers.
This may not be an optimal value, depending on the link between the two tunnel
endpoints. It can be adjusted via
.Xr ifconfig 8 .
.Pp
For correct operation, the
.Nm
device needs a route to the destination that is less specific than the
one over the tunnel.
(Basically, there needs to be a route to the decapsulating host that
does not run over the tunnel, as this would be a loop.)
If the addresses are ambiguous, doing the
.Xr ifconfig 8
.Li tunnel
step before the
.Xr ifconfig 8
call to set the
.Sy gre Ns Ar X
IP addresses will help to find a route outside the tunnel.
.Pp
In order to tell
.Xr ifconfig 8
to actually mark the interface as up, the keyword
.Dq up
must be given last on its command line.
.Pp
The kernel must be set to forward datagrams by either option
.Em GATEWAY
in the kernel config file or by issuing the appropriate option to
.Xr sysctl 8 .
.Sh SEE ALSO
.Xr atalk 4 ,
.Xr gif 4 ,
.Xr inet 4 ,
.Xr ip 4 ,
.Xr netintro 4 ,
.Xr options 4 ,
.Xr protocols 5 ,
.Xr ifconfig 8 ,
.Xr sysctl 8
.Pp
A description of GRE encapsulation can be found in RFC 1701 and RFC 1702.
.Pp
A description of MOBILE encapsulation can be found in RFC 2004.
.Sh AUTHORS
.An Heiko W.Rupp Aq hwr@pilhuhn.de
.Sh BUGS
The compute_route() code in if_gre.c toggles the last bit of the
IP-address to provoke the search for a less specific route than the
one directly over the tunnel to prevent loops. This is possibly not
the best solution.
.Pp
To avoid the address munging described above, turn on the link1 flag
on the
.Xr ifconfig 8
command line.
This implies that the GRE packet destination and the ifconfig remote host
are not the same IP addresses, and that the GRE destination does not route
over the
.Sy gre Ns Ar X
interface itself.
.Pp
The GRE RFCs are not yet fully implemented (no GRE options).

2
sys/conf/files
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@ -1054,6 +1054,7 @@ net/if_ethersubr.c optional ether
net/if_faith.c optional faith
net/if_fddisubr.c optional fddi
net/if_gif.c optional gif
net/if_gre.c optional gre
net/if_iso88025subr.c optional token
net/if_loop.c optional loop
net/if_media.c standard
@ -1216,6 +1217,7 @@ netinet/if_ether.c optional ether
netinet/igmp.c optional inet
netinet/in.c optional inet
netinet/in_gif.c optional gif inet
netinet/ip_gre.c optional gre inet
netinet/ip_id.c optional inet
netinet/in_pcb.c optional inet
netinet/in_proto.c optional inet

1
sys/conf/options
View File

@ -327,6 +327,7 @@ IPTUNNEL opt_ipx.h
LIBMCHAIN
NCP opt_ncp.h
NETATALK opt_atalk.h
NS opt_ns.h
PPP_BSDCOMP opt_ppp.h
PPP_DEFLATE opt_ppp.h
PPP_FILTER opt_ppp.h

781
sys/net/if_gre.c Normal file
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/* $NetBSD: if_gre.c,v 1.42 2002/08/14 00:23:27 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.
*/
/*
* Encapsulate L3 protocols into IP
* See RFC 1701 and 1702 for more details.
* If_gre is compatible with Cisco GRE tunnels, so you can
* have a NetBSD box as the other end of a tunnel interface of a Cisco
* router. See gre(4) for more details.
* Also supported: IP in IP encaps (proto 55) as of RFC 2004
*/
#include <sys/cdefs.h>
__RCSID("@(#) $FreeBSD$");
#include "opt_inet.h"
#include "opt_ns.h"
#include "bpf.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_gre.h>
#include <netinet/ip_var.h>
#include <netinet/ip_encap.h>
#else
#error "Huh? if_gre without inet?"
#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
#if NBPF > 0
#include <sys/time.h>
#include <net/bpf.h>
#endif
#include <net/net_osdep.h>
#include <net/if_gre.h>
/*
* It is not easy to calculate the right value for a GRE MTU.
* We leave this task to the admin and use the same default that
* other vendors use.
*/
#define GREMTU 1476
#define GRENAME "gre"
static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
struct gre_softc_head gre_softc_list;
int ip_gre_ttl = GRE_TTL;
int gre_clone_create __P((struct if_clone *, int));
void gre_clone_destroy __P((struct ifnet *));
struct if_clone gre_cloner =
IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT);
int gre_compute_route(struct gre_softc *sc);
void greattach __P((void));
#ifdef INET
extern struct domain inetdomain;
static const struct protosw in_gre_protosw =
{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
(pr_input_t*)gre_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
0,
0, 0, 0, 0,
&rip_usrreqs
};
static const struct protosw in_mobile_protosw =
{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
(pr_input_t*)gre_mobile_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
0,
0, 0, 0, 0,
&rip_usrreqs
};
#endif
SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
"Generic Routing Encapsulation");
#ifndef MAX_GRE_NEST
/*
* This macro controls the default upper limitation on nesting of gre tunnels.
* Since, setting a large value to this macro with a careless configuration
* may introduce system crash, we don't allow any nestings by default.
* If you need to configure nested gre tunnels, you can define this macro
* in your kernel configuration file. However, if you do so, please be
* careful to configure the tunnels so that it won't make a loop.
*/
#define MAX_GRE_NEST 1
#endif
static int max_gre_nesting = MAX_GRE_NEST;
SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
&max_gre_nesting, 0, "Max nested tunnels");
/* ARGSUSED */
void
greattach(void)
{
LIST_INIT(&gre_softc_list);
if_clone_attach(&gre_cloner);
}
int
gre_clone_create(ifc, unit)
struct if_clone *ifc;
int unit;
{
struct gre_softc *sc;
sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
memset(sc, 0, sizeof(struct gre_softc));
sc->sc_if.if_name = GRENAME;
sc->sc_if.if_softc = sc;
sc->sc_if.if_unit = unit;
sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
sc->sc_if.if_type = IFT_OTHER;
sc->sc_if.if_addrlen = 0;
sc->sc_if.if_hdrlen = 24; /* IP + GRE */
sc->sc_if.if_mtu = GREMTU;
sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
sc->sc_if.if_output = gre_output;
sc->sc_if.if_ioctl = gre_ioctl;
sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
sc->g_proto = IPPROTO_GRE;
sc->sc_if.if_flags |= IFF_LINK0;
sc->encap = NULL;
sc->called = 0;
if_attach(&sc->sc_if);
#if NBPF
bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
#endif
LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
return (0);
}
void
gre_clone_destroy(ifp)
struct ifnet *ifp;
{
struct gre_softc *sc = ifp->if_softc;
#ifdef INET
if (sc->encap != NULL)
encap_detach(sc->encap);
#endif
LIST_REMOVE(sc, sc_list);
#if NBPF
bpfdetach(ifp);
#endif
if_detach(ifp);
free(sc, M_GRE);
}
/*
* The output routine. Takes a packet and encapsulates it in the protocol
* given by sc->g_proto. See also RFC 1701 and RFC 2004
*/
int
gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
struct rtentry *rt)
{
int error = 0;
struct gre_softc *sc = ifp->if_softc;
struct greip *gh;
struct ip *ip;
u_char osrc;
u_short etype = 0;
struct mobile_h mob_h;
/*
* gre may cause infinite recursion calls when misconfigured.
* We'll prevent this by introducing upper limit.
*/
if (++(sc->called) > max_gre_nesting) {
printf("%s: gre_output: recursively called too many "
"times(%d)\n", if_name(&sc->sc_if), sc->called);
m_freem(m);
error = EIO; /* is there better errno? */
goto end;
}
if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
m_freem(m);
error = ENETDOWN;
goto end;
}
gh = NULL;
ip = NULL;
osrc = 0;
#if NBPF
if (ifp->if_bpf) {
/* see comment of other if_foo.c files */
struct mbuf m0;
u_int32_t af = dst->sa_family;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af;
bpf_mtap(ifp, &m0);
}
#endif
m->m_flags &= ~(M_BCAST|M_MCAST);
if (sc->g_proto == IPPROTO_MOBILE) {
if (dst->sa_family == AF_INET) {
struct mbuf *m0;
int msiz;
ip = mtod(m, struct ip *);
/*
* RFC2004 specifies that fragmented diagrams shouldn't
* be encapsulated.
*/
if ((ip->ip_off & IP_MF) != 0) {
_IF_DROP(&ifp->if_snd);
m_freem(m);
error = EINVAL; /* is there better errno? */
goto end;
}
memset(&mob_h, 0, MOB_H_SIZ_L);
mob_h.proto = (ip->ip_p) << 8;
mob_h.odst = ip->ip_dst.s_addr;
ip->ip_dst.s_addr = sc->g_dst.s_addr;
/*
* If the packet comes from our host, we only change
* the destination address in the IP header.
* Else we also need to save and change the source
*/
if (in_hosteq(ip->ip_src, sc->g_src)) {
msiz = MOB_H_SIZ_S;
} else {
mob_h.proto |= MOB_H_SBIT;
mob_h.osrc = ip->ip_src.s_addr;
ip->ip_src.s_addr = sc->g_src.s_addr;
msiz = MOB_H_SIZ_L;
}
mob_h.proto = htons(mob_h.proto);
mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
if ((m->m_data - msiz) < m->m_pktdat) {
/* need new mbuf */
MGETHDR(m0, M_DONTWAIT, MT_HEADER);
if (m0 == NULL) {
_IF_DROP(&ifp->if_snd);
m_freem(m);
error = ENOBUFS;
goto end;
}
m0->m_next = m;
m->m_data += sizeof(struct ip);
m->m_len -= sizeof(struct ip);
m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
m0->m_len = msiz + sizeof(struct ip);
m0->m_data += max_linkhdr;
memcpy(mtod(m0, caddr_t), (caddr_t)ip,
sizeof(struct ip));
m = m0;
} else { /* we have some space left in the old one */
m->m_data -= msiz;
m->m_len += msiz;
m->m_pkthdr.len += msiz;
bcopy(ip, mtod(m, caddr_t),
sizeof(struct ip));
}
ip = mtod(m, struct ip *);
memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
ip->ip_len = ntohs(ip->ip_len) + msiz;
} else { /* AF_INET */
_IF_DROP(&ifp->if_snd);
m_freem(m);
error = EINVAL;
goto end;
}
} else if (sc->g_proto == IPPROTO_GRE) {
switch (dst->sa_family) {
case AF_INET:
ip = mtod(m, struct ip *);
etype = ETHERTYPE_IP;
break;
#ifdef NETATALK
case AF_APPLETALK:
etype = ETHERTYPE_ATALK;
break;
#endif
#ifdef NS
case AF_NS:
etype = ETHERTYPE_NS;
break;
#endif
default:
_IF_DROP(&ifp->if_snd);
m_freem(m);
error = EAFNOSUPPORT;
goto end;
}
M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
} else {
_IF_DROP(&ifp->if_snd);
m_freem(m);
error = EINVAL;
goto end;
}
if (m == NULL) { /* impossible */
_IF_DROP(&ifp->if_snd);
error = ENOBUFS;
goto end;
}
gh = mtod(m, struct greip *);
if (sc->g_proto == IPPROTO_GRE) {
/* we don't have any GRE flags for now */
memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
gh->gi_ptype = htons(etype);
}
gh->gi_pr = sc->g_proto;
if (sc->g_proto != IPPROTO_MOBILE) {
gh->gi_src = sc->g_src;
gh->gi_dst = sc->g_dst;
((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
((struct ip*)gh)->ip_ttl = ip_gre_ttl;
((struct ip*)gh)->ip_tos = ip->ip_tos;
((struct ip*)gh)->ip_id = ip->ip_id;
gh->gi_len = m->m_pkthdr.len;
}
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
/* send it off */
error = ip_output(m, NULL, &sc->route, 0, NULL);
end:
sc->called = 0;
if (error)
ifp->if_oerrors++;
return (error);
}
int
gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr = (struct ifreq *)data;
struct if_laddrreq *lifr = (struct if_laddrreq *)data;
struct in_aliasreq *aifr = (struct in_aliasreq *)data;
struct gre_softc *sc = ifp->if_softc;
int s;
struct sockaddr_in si;
struct sockaddr *sa = NULL;
int error;
struct sockaddr_in sp, sm, dp, dm;
error = 0;
s = splnet();
switch (cmd) {
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP;
break;
case SIOCSIFDSTADDR:
break;
case SIOCSIFFLAGS:
if ((error = suser(curthread)) != 0)
break;
if ((ifr->ifr_flags & IFF_LINK0) != 0)
sc->g_proto = IPPROTO_GRE;
else
sc->g_proto = IPPROTO_MOBILE;
goto recompute;
case SIOCSIFMTU:
if ((error = suser(curthread)) != 0)
break;
if (ifr->ifr_mtu < 576) {
error = EINVAL;
break;
}
ifp->if_mtu = ifr->ifr_mtu;
break;
case SIOCGIFMTU:
ifr->ifr_mtu = sc->sc_if.if_mtu;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if ((error = suser(curthread)) != 0)
break;
if (ifr == 0) {
error = EAFNOSUPPORT;
break;
}
switch (ifr->ifr_addr.sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case GRESPROTO:
if ((error = suser(curthread)) != 0)
break;
sc->g_proto = ifr->ifr_flags;
switch (sc->g_proto) {
case IPPROTO_GRE:
ifp->if_flags |= IFF_LINK0;
break;
case IPPROTO_MOBILE:
ifp->if_flags &= ~IFF_LINK0;
break;
default:
error = EPROTONOSUPPORT;
break;
}
goto recompute;
case GREGPROTO:
ifr->ifr_flags = sc->g_proto;
break;
case GRESADDRS:
case GRESADDRD:
if ((error = suser(curthread)) != 0)
break;
/*
* set tunnel endpoints, compute a less specific route
* to the remote end and mark if as up
*/
sa = &ifr->ifr_addr;
if (cmd == GRESADDRS)
sc->g_src = (satosin(sa))->sin_addr;
if (cmd == GRESADDRD)
sc->g_dst = (satosin(sa))->sin_addr;
recompute:
#ifdef INET
if (sc->encap != NULL) {
encap_detach(sc->encap);
sc->encap = NULL;
}
#endif
if ((sc->g_src.s_addr != INADDR_ANY) &&
(sc->g_dst.s_addr != INADDR_ANY)) {
bzero(&sp, sizeof(sp));
bzero(&sm, sizeof(sm));
bzero(&dp, sizeof(dp));
bzero(&dm, sizeof(dm));
sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
sizeof(struct sockaddr_in);
sp.sin_family = sm.sin_family = dp.sin_family =
dm.sin_family = AF_INET;
sp.sin_addr = sc->g_src;
dp.sin_addr = sc->g_dst;
sm.sin_addr.s_addr = dm.sin_addr.s_addr =
INADDR_BROADCAST;
#ifdef INET
sc->encap = encap_attach(AF_INET, sc->g_proto,
sintosa(&sp), sintosa(&sm), sintosa(&dp),
sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
&in_gre_protosw : &in_mobile_protosw, sc);
if (sc->encap == NULL)
printf("%s: unable to attach encap\n",
if_name(&sc->sc_if));
#endif
if (sc->route.ro_rt != 0) /* free old route */
RTFREE(sc->route.ro_rt);
if (gre_compute_route(sc) == 0)
ifp->if_flags |= IFF_RUNNING;
else
ifp->if_flags &= ~IFF_RUNNING;
}
break;
case GREGADDRS:
memset(&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_len = sizeof(struct sockaddr_in);
si.sin_addr.s_addr = sc->g_src.s_addr;
sa = sintosa(&si);
ifr->ifr_addr = *sa;
break;
case GREGADDRD:
memset(&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_len = sizeof(struct sockaddr_in);
si.sin_addr.s_addr = sc->g_dst.s_addr;
sa = sintosa(&si);
ifr->ifr_addr = *sa;
break;
case SIOCSIFPHYADDR:
if ((error = suser(curthread)) != 0)
break;
if (aifr->ifra_addr.sin_family != AF_INET ||
aifr->ifra_dstaddr.sin_family != AF_INET) {
error = EAFNOSUPPORT;
break;
}
if (aifr->ifra_addr.sin_len != sizeof(si) ||
aifr->ifra_dstaddr.sin_len != sizeof(si)) {
error = EINVAL;
break;
}
sc->g_src = aifr->ifra_addr.sin_addr;
sc->g_dst = aifr->ifra_dstaddr.sin_addr;
goto recompute;
case SIOCSLIFPHYADDR:
if ((error = suser(curthread)) != 0)
break;
if (lifr->addr.ss_family != AF_INET ||
lifr->dstaddr.ss_family != AF_INET) {
error = EAFNOSUPPORT;
break;
}
if (lifr->addr.ss_len != sizeof(si) ||
lifr->dstaddr.ss_len != sizeof(si)) {
error = EINVAL;
break;
}
sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
sc->g_dst =
(satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
goto recompute;
case SIOCDIFPHYADDR:
if ((error = suser(curthread)) != 0)
break;
sc->g_src.s_addr = INADDR_ANY;
sc->g_dst.s_addr = INADDR_ANY;
goto recompute;
case SIOCGLIFPHYADDR:
if (sc->g_src.s_addr == INADDR_ANY ||
sc->g_dst.s_addr == INADDR_ANY) {
error = EADDRNOTAVAIL;
break;
}
memset(&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_len = sizeof(struct sockaddr_in);
si.sin_addr.s_addr = sc->g_src.s_addr;
memcpy(&lifr->addr, &si, sizeof(si));
si.sin_addr.s_addr = sc->g_dst.s_addr;
memcpy(&lifr->dstaddr, &si, sizeof(si));
break;
case SIOCGIFPSRCADDR:
if (sc->g_src.s_addr == INADDR_ANY) {
error = EADDRNOTAVAIL;
break;
}
memset(&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_len = sizeof(struct sockaddr_in);
si.sin_addr.s_addr = sc->g_src.s_addr;
bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
break;
case SIOCGIFPDSTADDR:
if (sc->g_dst.s_addr == INADDR_ANY) {
error = EADDRNOTAVAIL;
break;
}
memset(&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_len = sizeof(struct sockaddr_in);
si.sin_addr.s_addr = sc->g_dst.s_addr;
bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
break;
default:
error = EINVAL;
break;
}
splx(s);
return (error);
}
/*
* computes a route to our destination that is not the one
* which would be taken by ip_output(), as this one will loop back to
* us. If the interface is p2p as a--->b, then a routing entry exists
* If we now send a packet to b (e.g. ping b), this will come down here
* gets src=a, dst=b tacked on and would from ip_ouput() sent back to
* if_gre.
* Goal here is to compute a route to b that is less specific than
* a-->b. We know that this one exists as in normal operation we have
* at least a default route which matches.
*/
int
gre_compute_route(struct gre_softc *sc)
{
struct route *ro;
u_int32_t a, b, c;
ro = &sc->route;
memset(ro, 0, sizeof(struct route));
((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
ro->ro_dst.sa_family = AF_INET;
ro->ro_dst.sa_len = sizeof(ro->ro_dst);
/*
* toggle last bit, so our interface is not found, but a less
* specific route. I'd rather like to specify a shorter mask,
* but this is not possible. Should work though. XXX
* there is a simpler way ...
*/
if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
a = ntohl(sc->g_dst.s_addr);
b = a & 0x01;
c = a & 0xfffffffe;
b = b ^ 0x01;
a = b | c;
((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
= htonl(a);
}
#ifdef DIAGNOSTIC
printf("%s: searching a route to %s", if_name(&sc->sc_if),
inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
#endif
rtalloc(ro);
/*
* check if this returned a route at all and this route is no
* recursion to ourself
*/
if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
#ifdef DIAGNOSTIC
if (ro->ro_rt == NULL)
printf(" - no route found!\n");
else
printf(" - route loops back to ourself!\n");
#endif
return EADDRNOTAVAIL;
}
/*
* now change it back - else ip_output will just drop
* the route and search one to this interface ...
*/
if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
#ifdef DIAGNOSTIC
printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
printf("\n");
#endif
return 0;
}
/*
* do a checksum of a buffer - much like in_cksum, which operates on
* mbufs.
*/
u_short
gre_in_cksum(u_short *p, u_int len)
{
u_int sum = 0;
int nwords = len >> 1;
while (nwords-- != 0)
sum += *p++;
if (len & 1) {
union {
u_short w;
u_char c[2];
} u;
u.c[0] = *(u_char *)p;
u.c[1] = 0;
sum += u.w;
}
/* end-around-carry */
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16);
return (~sum);
}
static int
gremodevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
greattach();
break;
case MOD_UNLOAD:
if_clone_detach(&gre_cloner);
while (!LIST_EMPTY(&gre_softc_list))
gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
break;
}
return 0;
}
static moduledata_t gre_mod = {
"if_gre",
gremodevent,
0
};
DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_gre, 1);

166
sys/net/if_gre.h Normal file
View File

@ -0,0 +1,166 @@
/* $NetBSD: if_gre.h,v 1.10 2002/02/24 17:22:20 martin 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.
*/
#ifndef _NET_IF_GRE_H
#define _NET_IF_GRE_H
#include <sys/ioccom.h>
#include <sys/queue.h>
struct gre_softc {
struct ifnet sc_if;
LIST_ENTRY(gre_softc) sc_list;
int gre_unit;
int gre_flags;
struct in_addr g_src; /* source address of gre packets */
struct in_addr g_dst; /* destination address of gre packets */
struct route route; /* routing entry that determines, where a
encapsulated packet should go */
u_char g_proto; /* protocol of encapsulator */
const struct encaptab *encap; /* encapsulation cookie */
int called; /* infinite recursion preventer */
};
struct gre_h {
u_int16_t flags; /* GRE flags */
u_int16_t ptype; /* protocol type of payload typically
Ether protocol type*/
/*
* from here on: fields are optional, presence indicated by flags
*
u_int_16 checksum checksum (one-complements of GRE header
and payload
Present if (ck_pres | rt_pres == 1).
Valid if (ck_pres == 1).
u_int_16 offset offset from start of routing filed to
first octet of active SRE (see below).
Present if (ck_pres | rt_pres == 1).
Valid if (rt_pres == 1).
u_int_32 key inserted by encapsulator e.g. for
authentication
Present if (key_pres ==1 ).
u_int_32 seq_num Sequence number to allow for packet order
Present if (seq_pres ==1 ).
struct gre_sre[] routing Routing fileds (see below)
Present if (rt_pres == 1)
*/
} __attribute__((__packed__));
struct greip {
struct ip gi_i;
struct gre_h gi_g;
} __attribute__((__packed__));
#define gi_pr gi_i.ip_p
#define gi_len gi_i.ip_len
#define gi_src gi_i.ip_src
#define gi_dst gi_i.ip_dst
#define gi_ptype gi_g.ptype
#define gi_flags gi_g.flags
#define GRE_CP 0x8000 /* Checksum Present */
#define GRE_RP 0x4000 /* Routing Present */
#define GRE_KP 0x2000 /* Key Present */
#define GRE_SP 0x1000 /* Sequence Present */
#define GRE_SS 0x0800 /* Strict Source Route */
/*
* gre_sre defines a Source route Entry. These are needed if packets
* should be routed over more than one tunnel hop by hop
*/
struct gre_sre {
u_int16_t sre_family; /* adress family */
u_char sre_offset; /* offset to first octet of active entry */
u_char sre_length; /* number of octets in the SRE.
sre_lengthl==0 -> last entry. */
u_char *sre_rtinfo; /* the routing information */
};
struct greioctl {
int unit;
struct in_addr addr;
};
/* for mobile encaps */
struct mobile_h {
u_int16_t proto; /* protocol and S-bit */
u_int16_t hcrc; /* header checksum */
u_int32_t odst; /* original destination address */
u_int32_t osrc; /* original source addr, if S-bit set */
} __attribute__((__packed__));
struct mobip_h {
struct ip mi;
struct mobile_h mh;
} __attribute__((__packed__));
#define MOB_H_SIZ_S (sizeof(struct mobile_h) - sizeof(u_int32_t))
#define MOB_H_SIZ_L (sizeof(struct mobile_h))
#define MOB_H_SBIT 0x0080
#define GRE_TTL 30
extern int ip_gre_ttl;
/*
* ioctls needed to manipulate the interface
*/
#define GRESADDRS _IOW('i', 101, struct ifreq)
#define GRESADDRD _IOW('i', 102, struct ifreq)
#define GREGADDRS _IOWR('i', 103, struct ifreq)
#define GREGADDRD _IOWR('i', 104, struct ifreq)
#define GRESPROTO _IOW('i' , 105, struct ifreq)
#define GREGPROTO _IOWR('i', 106, struct ifreq)
#ifdef _KERNEL
LIST_HEAD(gre_softc_head, gre_softc);
extern struct gre_softc_head gre_softc_list;
int gre_ioctl __P((struct ifnet *, u_long, caddr_t));
int gre_output __P((struct ifnet *, struct mbuf *, struct sockaddr *,
struct rtentry *rt));
u_short gre_in_cksum(u_short *p, u_int len);
#endif /* _KERNEL */
#endif

12
sys/netinet/in_proto.c
View File

@ -160,6 +160,18 @@ struct protosw inetsw[] = {
encap_init, 0, 0, 0,
&rip_usrreqs
},
{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR|PR_LASTHDR,
encap4_input, 0, 0, rip_ctloutput,
0,
encap_init, 0, 0, 0,
&rip_usrreqs
},
{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR|PR_LASTHDR,
encap4_input, 0, 0, rip_ctloutput,
0,
encap_init, 0, 0, 0,
&rip_usrreqs
},
# ifdef INET6
{ SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR|PR_LASTHDR,
encap4_input, 0, 0, rip_ctloutput,

360
sys/netinet/ip_gre.c Normal file
View File

@ -0,0 +1,360 @@
/* $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 <sys/cdefs.h>
__RCSID("@(#) $FreeBSD$");
#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
struct gre_softc *gre_lookup __P((struct mbuf *, u_int8_t));
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.
*/
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;
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 *)&af;
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 *)&af;
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.
*/
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);
}

43
sys/netinet/ip_gre.h Normal file
View File

@ -0,0 +1,43 @@
/* $NetBSD: ip_gre.h,v 1.5 2002/06/09 16:33:40 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.
*/
#ifdef _KERNEL
void gre_input __P((struct mbuf *, ...));
void gre_mobile_input __P((struct mbuf *, ...));
#endif /* _KERNEL */