NetBSD/sys/net/if_gif.c
itojun 4d51fe368b change the meaning of ifnet.if_lastchange to meet RFC1573 ifLastChange.
follows BSD/OS practice and ucd-snmp code (FreeBSD does it for specific
interfaces only).

was: if_lastchange get updated on every packet transmission/receipt.
now: if_lastchange get updated when IFF_UP is changed.
2001-06-14 05:44:23 +00:00

871 lines
19 KiB
C

/* $NetBSD: if_gif.c,v 1.29 2001/06/14 05:44:24 itojun Exp $ */
/* $KAME: if_gif.c,v 1.49 2001/06/04 12:03:41 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
#include "opt_inet.h"
#include "opt_iso.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET
#include <netinet/in_var.h>
#include <netinet/in_gif.h>
#endif /* INET */
#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_gif.h>
#include <netinet6/ip6protosw.h>
#endif /* INET6 */
#ifdef ISO
#include <netiso/iso.h>
#include <netiso/iso_var.h>
#endif
#include <netinet/ip_encap.h>
#include <net/if_gif.h>
#include "gif.h"
#include "bpfilter.h"
#include <net/net_osdep.h>
#if NGIF > 0
void gifattach __P((int));
static int gif_encapcheck __P((const struct mbuf *, int, int, void *));
#ifdef INET
extern struct protosw in_gif_protosw;
#endif
#ifdef INET6
extern struct ip6protosw in6_gif_protosw;
#endif
#ifdef ISO
static int gif_eon_encap(struct mbuf **);
static int gif_eon_decap(struct ifnet *, struct mbuf **);
#endif
/*
* gif global variable definitions
*/
LIST_HEAD(, gif_softc) gif_softc_list;
int gif_clone_create __P((struct if_clone *, int));
void gif_clone_destroy __P((struct ifnet *));
struct if_clone gif_cloner =
IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy);
void gif_delete_tunnel __P((struct gif_softc *));
#ifndef MAX_GIF_NEST
/*
* This macro controls the upper limitation on nesting of gif 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 gif 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_GIF_NEST 1
#endif
static int max_gif_nesting = MAX_GIF_NEST;
/* ARGSUSED */
void
gifattach(count)
int count;
{
LIST_INIT(&gif_softc_list);
if_clone_attach(&gif_cloner);
}
int
gif_clone_create(ifc, unit)
struct if_clone *ifc;
int unit;
{
struct gif_softc *sc;
sc = malloc(sizeof(struct gif_softc), M_DEVBUF, M_WAIT);
bzero(sc, sizeof(struct gif_softc));
sprintf(sc->gif_if.if_xname, "%s%d", ifc->ifc_name, unit);
sc->encap_cookie4 = sc->encap_cookie6 = NULL;
#ifdef INET
sc->encap_cookie4 = encap_attach_func(AF_INET, -1,
gif_encapcheck, &in_gif_protosw, sc);
if (sc->encap_cookie4 == NULL) {
printf("%s: unable to attach encap4\n", if_name(&sc->gif_if));
free(sc, M_DEVBUF);
return (EIO); /* XXX */
}
#endif
#ifdef INET6
sc->encap_cookie6 = encap_attach_func(AF_INET6, -1,
gif_encapcheck, (struct protosw *)&in6_gif_protosw, sc);
if (sc->encap_cookie6 == NULL) {
if (sc->encap_cookie4) {
encap_detach(sc->encap_cookie4);
sc->encap_cookie4 = NULL;
}
printf("%s: unable to attach encap6\n", if_name(&sc->gif_if));
free(sc, M_DEVBUF);
return (EIO); /* XXX */
}
#endif
sc->gif_if.if_mtu = GIF_MTU;
sc->gif_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
sc->gif_if.if_ioctl = gif_ioctl;
sc->gif_if.if_output = gif_output;
sc->gif_if.if_type = IFT_GIF;
sc->gif_if.if_dlt = DLT_NULL;
if_attach(&sc->gif_if);
if_alloc_sadl(&sc->gif_if);
#if NBPFILTER > 0
bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
#endif
LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
return (0);
}
void
gif_clone_destroy(ifp)
struct ifnet *ifp;
{
struct gif_softc *sc = (void *) ifp;
gif_delete_tunnel(sc);
LIST_REMOVE(sc, gif_list);
#ifdef INET6
encap_detach(sc->encap_cookie6);
#endif
#ifdef INET
encap_detach(sc->encap_cookie4);
#endif
#if NBPFILTER > 0
bpfdetach(ifp);
#endif
if_detach(ifp);
free(sc, M_DEVBUF);
}
static int
gif_encapcheck(m, off, proto, arg)
const struct mbuf *m;
int off;
int proto;
void *arg;
{
struct ip ip;
struct gif_softc *sc;
sc = (struct gif_softc *)arg;
if (sc == NULL)
return 0;
if ((sc->gif_if.if_flags & IFF_UP) == 0)
return 0;
/* no physical address */
if (!sc->gif_psrc || !sc->gif_pdst)
return 0;
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
break;
#endif
#ifdef INET6
case IPPROTO_IPV6:
break;
#endif
#ifdef ISO
case IPPROTO_EON:
break;
#endif
default:
return 0;
}
/* LINTED const cast */
m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip);
switch (ip.ip_v) {
#ifdef INET
case 4:
if (sc->gif_psrc->sa_family != AF_INET ||
sc->gif_pdst->sa_family != AF_INET)
return 0;
return gif_encapcheck4(m, off, proto, arg);
#endif
#ifdef INET6
case 6:
if (sc->gif_psrc->sa_family != AF_INET6 ||
sc->gif_pdst->sa_family != AF_INET6)
return 0;
return gif_encapcheck6(m, off, proto, arg);
#endif
default:
return 0;
}
}
int
gif_output(ifp, m, dst, rt)
struct ifnet *ifp;
struct mbuf *m;
struct sockaddr *dst;
struct rtentry *rt; /* added in net2 */
{
struct gif_softc *sc = (struct gif_softc*)ifp;
int error = 0;
static int called = 0; /* XXX: MUTEX */
/*
* gif may cause infinite recursion calls when misconfigured.
* We'll prevent this by introducing upper limit.
* XXX: this mechanism may introduce another problem about
* mutual exclusion of the variable CALLED, especially if we
* use kernel thread.
*/
if (++called > max_gif_nesting) {
log(LOG_NOTICE,
"gif_output: recursively called too many times(%d)\n",
called);
m_freem(m);
error = EIO; /* is there better errno? */
goto end;
}
m->m_flags &= ~(M_BCAST|M_MCAST);
if (!(ifp->if_flags & IFF_UP) ||
sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
m_freem(m);
error = ENETDOWN;
goto end;
}
#if NBPFILTER > 0
if (ifp->if_bpf) {
/*
* We need to prepend the address family as
* a four byte field. Cons up a dummy header
* to pacify bpf. This is safe because bpf
* will only read from the mbuf (i.e., it won't
* try to free it or keep a pointer a to it).
*/
struct mbuf m0;
u_int32_t af = dst->sa_family;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af;
#ifdef HAVE_OLD_BPF
bpf_mtap(ifp, &m0);
#else
bpf_mtap(ifp->if_bpf, &m0);
#endif
}
#endif
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
/* inner AF-specific encapsulation */
switch (dst->sa_family) {
#ifdef ISO
case AF_ISO:
error = gif_eon_encap(&m);
if (error)
goto end;
#endif
default:
break;
}
/* XXX should we check if our outer source is legal? */
/* dispatch to output logic based on outer AF */
switch (sc->gif_psrc->sa_family) {
#ifdef INET
case AF_INET:
error = in_gif_output(ifp, dst->sa_family, m, rt);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gif_output(ifp, dst->sa_family, m, rt);
break;
#endif
default:
m_freem(m);
error = ENETDOWN;
}
end:
called = 0; /* reset recursion counter */
if (error) ifp->if_oerrors++;
return error;
}
void
gif_input(m, af, gifp)
struct mbuf *m;
int af;
struct ifnet *gifp;
{
int s, isr;
struct ifqueue *ifq = 0;
if (gifp == NULL) {
/* just in case */
m_freem(m);
return;
}
m->m_pkthdr.rcvif = gifp;
#if NBPFILTER > 0
if (gifp->if_bpf) {
/*
* We need to prepend the address family as
* a four byte field. Cons up a dummy header
* to pacify bpf. This is safe because bpf
* will only read from the mbuf (i.e., it won't
* try to free it or keep a pointer a to it).
*/
struct mbuf m0;
u_int32_t af1 = af;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af1;
#ifdef HAVE_OLD_BPF
bpf_mtap(gifp, &m0);
#else
bpf_mtap(gifp->if_bpf, &m0);
#endif
}
#endif /*NBPFILTER > 0*/
/*
* Put the packet to the network layer input queue according to the
* specified address family.
* Note: older versions of gif_input directly called network layer
* input functions, e.g. ip6_input, here. We changed the policy to
* prevent too many recursive calls of such input functions, which
* might cause kernel panic. But the change may introduce another
* problem; if the input queue is full, packets are discarded.
* We believed it rarely occurs and changed the policy. If we find
* it occurs more times than we thought, we may change the policy
* again.
*/
switch (af) {
#ifdef INET
case AF_INET:
ifq = &ipintrq;
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
ifq = &ip6intrq;
isr = NETISR_IPV6;
break;
#endif
#ifdef ISO
case AF_ISO:
if (gif_eon_decap(gifp, &m)) {
if (m)
m_freem(m);
return;
}
ifq = &clnlintrq;
isr = NETISR_ISO;
break;
#endif
default:
m_freem(m);
return;
}
s = splnet();
if (IF_QFULL(ifq)) {
IF_DROP(ifq); /* update statistics */
m_freem(m);
splx(s);
return;
}
IF_ENQUEUE(ifq, m);
/* we need schednetisr since the address family may change */
schednetisr(isr);
gifp->if_ipackets++;
gifp->if_ibytes += m->m_pkthdr.len;
splx(s);
return;
}
/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
int
gif_ioctl(ifp, cmd, data)
struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
struct proc *p = curproc; /* XXX */
struct gif_softc *sc = (struct gif_softc*)ifp;
struct ifreq *ifr = (struct ifreq*)data;
int error = 0, size;
struct sockaddr *dst, *src;
struct sockaddr *sa;
int s;
struct gif_softc *sc2;
switch (cmd) {
case SIOCSIFADDR:
break;
case SIOCSIFDSTADDR:
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
break;
switch (ifr->ifr_addr.sa_family) {
#ifdef INET
case AF_INET: /* IP supports Multicast */
break;
#endif /* INET */
#ifdef INET6
case AF_INET6: /* IP6 supports Multicast */
break;
#endif /* INET6 */
default: /* Other protocols doesn't support Multicast */
error = EAFNOSUPPORT;
break;
}
break;
#ifdef SIOCSIFMTU /* xxx */
case SIOCGIFMTU:
break;
case SIOCSIFMTU:
{
u_long mtu;
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
break;
mtu = ifr->ifr_mtu;
if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX) {
return (EINVAL);
}
ifp->if_mtu = mtu;
}
break;
#endif /* SIOCSIFMTU */
case SIOCSIFPHYADDR:
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
#endif /* INET6 */
case SIOCSLIFPHYADDR:
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
break;
switch (cmd) {
#ifdef INET
case SIOCSIFPHYADDR:
src = (struct sockaddr *)
&(((struct in_aliasreq *)data)->ifra_addr);
dst = (struct sockaddr *)
&(((struct in_aliasreq *)data)->ifra_dstaddr);
break;
#endif
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
src = (struct sockaddr *)
&(((struct in6_aliasreq *)data)->ifra_addr);
dst = (struct sockaddr *)
&(((struct in6_aliasreq *)data)->ifra_dstaddr);
break;
#endif
case SIOCSLIFPHYADDR:
src = (struct sockaddr *)
&(((struct if_laddrreq *)data)->addr);
dst = (struct sockaddr *)
&(((struct if_laddrreq *)data)->dstaddr);
}
/* sa_family must be equal */
if (src->sa_family != dst->sa_family)
return EINVAL;
/* validate sa_len */
switch (src->sa_family) {
#ifdef INET
case AF_INET:
if (src->sa_len != sizeof(struct sockaddr_in))
return EINVAL;
break;
#endif
#ifdef INET6
case AF_INET6:
if (src->sa_len != sizeof(struct sockaddr_in6))
return EINVAL;
break;
#endif
default:
return EAFNOSUPPORT;
}
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
if (dst->sa_len != sizeof(struct sockaddr_in))
return EINVAL;
break;
#endif
#ifdef INET6
case AF_INET6:
if (dst->sa_len != sizeof(struct sockaddr_in6))
return EINVAL;
break;
#endif
default:
return EAFNOSUPPORT;
}
/* check sa_family looks sane for the cmd */
switch (cmd) {
case SIOCSIFPHYADDR:
if (src->sa_family == AF_INET)
break;
return EAFNOSUPPORT;
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
if (src->sa_family == AF_INET6)
break;
return EAFNOSUPPORT;
#endif /* INET6 */
case SIOCSLIFPHYADDR:
/* checks done in the above */
break;
}
for (sc2 = LIST_FIRST(&gif_softc_list); sc2 != NULL;
sc2 = LIST_NEXT(sc2, gif_list)) {
if (sc2 == sc)
continue;
if (!sc2->gif_pdst || !sc2->gif_psrc)
continue;
if (sc2->gif_pdst->sa_family != dst->sa_family ||
sc2->gif_pdst->sa_len != dst->sa_len ||
sc2->gif_psrc->sa_family != src->sa_family ||
sc2->gif_psrc->sa_len != src->sa_len)
continue;
/* can't configure same pair of address onto two gifs */
if (bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
error = EADDRNOTAVAIL;
goto bad;
}
/* can't configure multiple multi-dest interfaces */
#define multidest(x) \
(((struct sockaddr_in *)(x))->sin_addr.s_addr == INADDR_ANY)
#ifdef INET6
#define multidest6(x) \
(IN6_IS_ADDR_UNSPECIFIED(&((struct sockaddr_in6 *)(x))->sin6_addr))
#endif
if (dst->sa_family == AF_INET &&
multidest(dst) && multidest(sc2->gif_pdst)) {
error = EADDRNOTAVAIL;
goto bad;
}
#ifdef INET6
if (dst->sa_family == AF_INET6 &&
multidest6(dst) && multidest6(sc2->gif_pdst)) {
error = EADDRNOTAVAIL;
goto bad;
}
#endif
}
if (sc->gif_psrc)
free((caddr_t)sc->gif_psrc, M_IFADDR);
sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
sc->gif_psrc = sa;
if (sc->gif_pdst)
free((caddr_t)sc->gif_pdst, M_IFADDR);
sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
sc->gif_pdst = sa;
s = splsoftnet();
ifp->if_flags |= IFF_RUNNING;
if_up(ifp); /* send up RTM_IFINFO */
splx(s);
error = 0;
break;
#ifdef SIOCDIFPHYADDR
case SIOCDIFPHYADDR:
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
break;
gif_delete_tunnel(sc);
break;
#endif
case SIOCGIFPSRCADDR:
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
#endif /* INET6 */
if (sc->gif_psrc == NULL) {
error = EADDRNOTAVAIL;
goto bad;
}
src = sc->gif_psrc;
switch (cmd) {
#ifdef INET
case SIOCGIFPSRCADDR:
dst = &ifr->ifr_addr;
size = sizeof(ifr->ifr_addr);
break;
#endif /* INET */
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
dst = (struct sockaddr *)
&(((struct in6_ifreq *)data)->ifr_addr);
size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
break;
#endif /* INET6 */
default:
error = EADDRNOTAVAIL;
goto bad;
}
if (src->sa_len > size)
return EINVAL;
bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
break;
case SIOCGIFPDSTADDR:
#ifdef INET6
case SIOCGIFPDSTADDR_IN6:
#endif /* INET6 */
if (sc->gif_pdst == NULL) {
error = EADDRNOTAVAIL;
goto bad;
}
src = sc->gif_pdst;
switch (cmd) {
#ifdef INET
case SIOCGIFPDSTADDR:
dst = &ifr->ifr_addr;
size = sizeof(ifr->ifr_addr);
break;
#endif /* INET */
#ifdef INET6
case SIOCGIFPDSTADDR_IN6:
dst = (struct sockaddr *)
&(((struct in6_ifreq *)data)->ifr_addr);
size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
break;
#endif /* INET6 */
default:
error = EADDRNOTAVAIL;
goto bad;
}
if (src->sa_len > size)
return EINVAL;
bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
break;
case SIOCGLIFPHYADDR:
if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
error = EADDRNOTAVAIL;
goto bad;
}
/* copy src */
src = sc->gif_psrc;
dst = (struct sockaddr *)
&(((struct if_laddrreq *)data)->addr);
size = sizeof(((struct if_laddrreq *)data)->addr);
if (src->sa_len > size)
return EINVAL;
bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
/* copy dst */
src = sc->gif_pdst;
dst = (struct sockaddr *)
&(((struct if_laddrreq *)data)->dstaddr);
size = sizeof(((struct if_laddrreq *)data)->dstaddr);
if (src->sa_len > size)
return EINVAL;
bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
break;
case SIOCSIFFLAGS:
/* if_ioctl() takes care of it */
break;
default:
error = EINVAL;
break;
}
bad:
return error;
}
void
gif_delete_tunnel(sc)
struct gif_softc *sc;
{
int s;
s = splsoftnet();
if (sc->gif_psrc) {
free((caddr_t)sc->gif_psrc, M_IFADDR);
sc->gif_psrc = NULL;
}
if (sc->gif_pdst) {
free((caddr_t)sc->gif_pdst, M_IFADDR);
sc->gif_pdst = NULL;
}
/* change the IFF_UP flag as well? */
splx(s);
}
#ifdef ISO
struct eonhdr {
u_int8_t version;
u_int8_t class;
u_int16_t cksum;
};
/*
* prepend EON header to ISO PDU
*/
static int
gif_eon_encap(struct mbuf **m)
{
struct eonhdr *ehdr;
M_PREPEND(*m, sizeof(*ehdr), M_DONTWAIT);
if (*m && (*m)->m_len < sizeof(*ehdr))
*m = m_pullup(*m, sizeof(*ehdr));
if (*m == NULL) {
printf("ENOBUFS in gif_eon_encap %d\n", __LINE__);
return ENOBUFS;
}
ehdr = mtod(*m, struct eonhdr *);
ehdr->version = 1;
ehdr->class = 0; /* always unicast */
#if 0
/* calculate the checksum of the eonhdr */
{
struct mbuf mhead;
memset(&mhead, 0, sizeof(mhead));
ehdr->cksum = 0;
mhead.m_data = (caddr_t)ehdr;
mhead.m_len = sizeof(*ehdr);
mhead.m_next = 0;
iso_gen_csum(&mhead, offsetof(struct eonhdr, cksum),
mhead.m_len);
}
#else
/* since the data is always constant we'll just plug the value in */
ehdr->cksum = htons(0xfc02);
#endif
return (0);
}
/*
* remove EON header and check checksum
*/
static int
gif_eon_decap(struct ifnet *gifp, struct mbuf **m)
{
struct eonhdr *ehdr;
if ((*m)->m_len < sizeof(*ehdr) &&
(*m = m_pullup(*m, sizeof(*ehdr))) == 0) {
gifp->if_ierrors++;
return (EINVAL);
}
if (iso_check_csum(*m, sizeof(struct eonhdr)))
return (EINVAL);
m_adj(*m, sizeof(*ehdr));
return (0);
}
#endif /*ISO*/
#endif /*NGIF > 0*/