588 lines
14 KiB
C
588 lines
14 KiB
C
/* $NetBSD: if_gre.c,v 1.12 2000/08/25 00:51:20 mjl 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.
|
|
*/
|
|
|
|
/*
|
|
* 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 "gre.h"
|
|
#if NGRE > 0
|
|
|
|
#include "opt_inet.h"
|
|
#include "opt_ns.h"
|
|
#include "bpfilter.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/queue.h>
|
|
#if __NetBSD__
|
|
#include <sys/systm.h>
|
|
#endif
|
|
|
|
#include <machine/cpu.h>
|
|
|
|
#include <net/ethertypes.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_var.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 NBPFILTER > 0
|
|
#include <sys/time.h>
|
|
#include <net/bpf.h>
|
|
#endif
|
|
|
|
#include <net/if_gre.h>
|
|
|
|
#define GREMTU 1450 /* XXX this is below the standard MTU of
|
|
1500 Bytes, allowing for headers,
|
|
but we should possibly do path mtu discovery
|
|
before changing if state to up to find the
|
|
correct value */
|
|
#define LINK_MASK (IFF_LINK0|IFF_LINK1|IFF_LINK2)
|
|
|
|
struct gre_softc_head gre_softc_list;
|
|
|
|
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);
|
|
|
|
void gre_compute_route(struct gre_softc *sc);
|
|
#ifdef DIAGNOSTIC
|
|
void gre_inet_ntoa(struct in_addr in);
|
|
#endif
|
|
|
|
void greattach __P((int));
|
|
|
|
/* ARGSUSED */
|
|
void
|
|
greattach(count)
|
|
int count;
|
|
{
|
|
|
|
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_DEVBUF, M_WAITOK);
|
|
memset(sc, 0, sizeof(struct gre_softc));
|
|
|
|
sprintf(sc->sc_if.if_xname, "%s%d", ifc->ifc_name, unit);
|
|
sc->sc_if.if_softc = sc;
|
|
sc->sc_if.if_type = IFT_OTHER;
|
|
sc->sc_if.if_addrlen = 4;
|
|
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;
|
|
if_attach(&sc->sc_if);
|
|
#if NBPFILTER > 0
|
|
bpfattach(&sc->gre_bpf, &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;
|
|
|
|
LIST_REMOVE(sc, sc_list);
|
|
#if NBPFILTER > 0
|
|
bpfdetach(ifp);
|
|
#endif
|
|
if_detach(ifp);
|
|
free(sc, M_DEVBUF);
|
|
}
|
|
|
|
/*
|
|
* The output routine. Takes a packet and encapsulates it in the protocol
|
|
* given by sc->g_proto. See also RFC 1701 and RFC 2004
|
|
*/
|
|
|
|
#if 0
|
|
struct ip ip_h;
|
|
#endif
|
|
struct mobile_h mob_h;
|
|
|
|
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 *inp;
|
|
u_char ttl, osrc;
|
|
u_short etype = 0;
|
|
|
|
|
|
gh = NULL;
|
|
inp = NULL;
|
|
osrc = 0;
|
|
|
|
#if NBPFILTER >0
|
|
if (sc->gre_bpf) {
|
|
/* see comment of other if_foo.c files */
|
|
struct mbuf m0;
|
|
u_int af = dst->sa_family;
|
|
|
|
m0.m_next = m;
|
|
m0.m_len = 4;
|
|
m0.m_data = (char *)⁡
|
|
|
|
bpf_mtap(sc->gre_bpf, &m0);
|
|
}
|
|
#endif
|
|
|
|
ttl = 255;
|
|
|
|
if (sc->g_proto == IPPROTO_MOBILE) {
|
|
if (dst->sa_family == AF_INET) {
|
|
struct mbuf *m0;
|
|
int msiz;
|
|
|
|
inp = mtod(m, struct ip *);
|
|
|
|
memset(&mob_h, 0, MOB_H_SIZ_L);
|
|
mob_h.proto = (inp->ip_p) << 8;
|
|
mob_h.odst = inp->ip_dst.s_addr;
|
|
inp->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(inp->ip_src, sc->g_src)) {
|
|
msiz = MOB_H_SIZ_S;
|
|
} else {
|
|
mob_h.proto |= MOB_H_SBIT;
|
|
mob_h.osrc = inp->ip_src.s_addr;
|
|
inp->ip_src.s_addr = sc->g_src.s_addr;
|
|
msiz = MOB_H_SIZ_L;
|
|
}
|
|
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);
|
|
return (ENOBUFS);
|
|
}
|
|
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)inp,
|
|
sizeof(struct ip));
|
|
m = m0;
|
|
} else { /* we have some spave left in the old one */
|
|
m->m_data -= msiz;
|
|
m->m_len += msiz;
|
|
m->m_pkthdr.len += msiz;
|
|
memmove(mtod(m, caddr_t), inp,
|
|
sizeof(struct ip));
|
|
}
|
|
inp=mtod(m, struct ip *);
|
|
memcpy((caddr_t)(inp + 1), &mob_h, (unsigned)msiz);
|
|
NTOHS(inp->ip_len);
|
|
inp->ip_len += msiz;
|
|
} else { /* AF_INET */
|
|
IF_DROP(&ifp->if_snd);
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
} else if (sc->g_proto == IPPROTO_GRE) {
|
|
switch(dst->sa_family) {
|
|
case AF_INET:
|
|
inp = mtod(m, struct ip *);
|
|
ttl = inp->ip_ttl;
|
|
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);
|
|
return (EAFNOSUPPORT);
|
|
}
|
|
M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
|
|
} else {
|
|
error = EINVAL;
|
|
IF_DROP(&ifp->if_snd);
|
|
m_freem(m);
|
|
return (error);
|
|
}
|
|
|
|
|
|
if (m == NULL) {
|
|
IF_DROP(&ifp->if_snd);
|
|
return (ENOBUFS);
|
|
}
|
|
|
|
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 = ttl;
|
|
((struct ip*)gh)->ip_tos = inp->ip_tos;
|
|
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);
|
|
if (error)
|
|
ifp->if_oerrors++;
|
|
return (error);
|
|
|
|
}
|
|
|
|
int
|
|
gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
|
|
{
|
|
|
|
struct ifaddr *ifa = (struct ifaddr *)data;
|
|
struct ifreq *ifr = (struct ifreq *)data;
|
|
struct in_ifaddr *ia = (struct in_ifaddr *)data;
|
|
struct gre_softc *sc = ifp->if_softc;
|
|
int s;
|
|
struct sockaddr_in si;
|
|
struct sockaddr *sa = NULL;
|
|
int error;
|
|
|
|
error = 0;
|
|
|
|
s = splimp();
|
|
switch(cmd) {
|
|
case SIOCSIFADDR:
|
|
case SIOCSIFDSTADDR:
|
|
/*
|
|
* set tunnel endpoints in case that we "only"
|
|
* have ip over ip encapsulation. This allows to
|
|
* set tunnel endpoints with ifconfig.
|
|
*/
|
|
if (ifa->ifa_addr->sa_family == AF_INET) {
|
|
sa = ifa->ifa_addr;
|
|
sc->g_src = (satosin(sa))->sin_addr;
|
|
sc->g_dst = ia->ia_dstaddr.sin_addr;
|
|
if ((sc->g_src.s_addr != INADDR_ANY) &&
|
|
(sc->g_dst.s_addr != INADDR_ANY)) {
|
|
if (sc->route.ro_rt != 0) /* free old route */
|
|
RTFREE(sc->route.ro_rt);
|
|
gre_compute_route(sc);
|
|
ifp->if_flags |= IFF_UP;
|
|
}
|
|
}
|
|
break;
|
|
case SIOCSIFFLAGS:
|
|
if ((sc->g_dst.s_addr == INADDR_ANY) ||
|
|
(sc->g_src.s_addr == INADDR_ANY))
|
|
ifp->if_flags &= ~IFF_UP;
|
|
|
|
switch(ifr->ifr_flags & LINK_MASK) {
|
|
case IFF_LINK0:
|
|
sc->g_proto = IPPROTO_GRE;
|
|
ifp->if_flags |= IFF_LINK0;
|
|
ifp->if_flags &= ~(IFF_LINK1|IFF_LINK2);
|
|
break;
|
|
case IFF_LINK2:
|
|
sc->g_proto = IPPROTO_MOBILE;
|
|
ifp->if_flags |= IFF_LINK2;
|
|
ifp->if_flags &= ~(IFF_LINK0|IFF_LINK1);
|
|
break;
|
|
}
|
|
break;
|
|
case SIOCSIFMTU:
|
|
if (ifr->ifr_mtu > GREMTU || 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 (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:
|
|
sc->g_proto = ifr->ifr_flags;
|
|
switch (sc->g_proto) {
|
|
case IPPROTO_GRE :
|
|
ifp->if_flags |= IFF_LINK0;
|
|
ifp->if_flags &= ~(IFF_LINK1|IFF_LINK2);
|
|
break;
|
|
case IPPROTO_MOBILE :
|
|
ifp->if_flags |= IFF_LINK2;
|
|
ifp->if_flags &= ~(IFF_LINK1|IFF_LINK2);
|
|
break;
|
|
default:
|
|
ifp->if_flags &= ~(IFF_LINK0|IFF_LINK1|IFF_LINK2);
|
|
}
|
|
break;
|
|
case GREGPROTO:
|
|
ifr->ifr_flags = sc->g_proto;
|
|
break;
|
|
case GRESADDRS:
|
|
case GRESADDRD:
|
|
/*
|
|
* 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;
|
|
if ((sc->g_src.s_addr != INADDR_ANY) &&
|
|
(sc->g_dst.s_addr != INADDR_ANY)) {
|
|
if (sc->route.ro_rt != 0) /* free old route */
|
|
RTFREE(sc->route.ro_rt);
|
|
gre_compute_route(sc);
|
|
ifp->if_flags |= IFF_UP;
|
|
}
|
|
break;
|
|
case GREGADDRS:
|
|
si.sin_addr.s_addr = sc->g_src.s_addr;
|
|
sa = sintosa(&si);
|
|
ifr->ifr_addr = *sa;
|
|
break;
|
|
case GREGADDRD:
|
|
si.sin_addr.s_addr = sc->g_dst.s_addr;
|
|
sa = sintosa(&si);
|
|
ifr->ifr_addr = *sa;
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
}
|
|
|
|
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.
|
|
*/
|
|
|
|
void
|
|
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 ", sc->sc_if.if_xname);
|
|
gre_inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr);
|
|
#endif
|
|
|
|
rtalloc(ro);
|
|
|
|
/*
|
|
* 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 ",ro->ro_rt->rt_ifp->if_xname);
|
|
gre_inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr);
|
|
printf("\n");
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
|
|
/* while testing ... */
|
|
#ifdef DIAGNOSTIC
|
|
void
|
|
gre_inet_ntoa(struct in_addr in)
|
|
{
|
|
char *p;
|
|
|
|
p = (char *)∈
|
|
#define UC(b) (((int)b)&0xff)
|
|
printf("%d.%d.%d.%d", UC(p[0]), UC(p[1]), UC(p[2]), UC(p[3]));
|
|
}
|
|
|
|
#endif
|
|
#endif
|
|
|