freebsd-dev/sys/net/if_gre.c
Pedro F. Giffuni fe267a5590 sys: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:23:17 +00:00

998 lines
22 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org>
* 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.
*
* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/libkern.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/rmlock.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_clone.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/vnet.h>
#include <net/route.h>
#include <netinet/in.h>
#ifdef INET
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#endif
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#endif
#include <netinet/ip_encap.h>
#include <net/bpf.h>
#include <net/if_gre.h>
#include <machine/in_cksum.h>
#include <security/mac/mac_framework.h>
#define GREMTU 1476
static const char grename[] = "gre";
static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation");
static VNET_DEFINE(struct mtx, gre_mtx);
#define V_gre_mtx VNET(gre_mtx)
#define GRE_LIST_LOCK_INIT(x) mtx_init(&V_gre_mtx, "gre_mtx", NULL, \
MTX_DEF)
#define GRE_LIST_LOCK_DESTROY(x) mtx_destroy(&V_gre_mtx)
#define GRE_LIST_LOCK(x) mtx_lock(&V_gre_mtx)
#define GRE_LIST_UNLOCK(x) mtx_unlock(&V_gre_mtx)
static VNET_DEFINE(LIST_HEAD(, gre_softc), gre_softc_list);
#define V_gre_softc_list VNET(gre_softc_list)
static struct sx gre_ioctl_sx;
SX_SYSINIT(gre_ioctl_sx, &gre_ioctl_sx, "gre_ioctl");
static int gre_clone_create(struct if_clone *, int, caddr_t);
static void gre_clone_destroy(struct ifnet *);
static VNET_DEFINE(struct if_clone *, gre_cloner);
#define V_gre_cloner VNET(gre_cloner)
static void gre_qflush(struct ifnet *);
static int gre_transmit(struct ifnet *, struct mbuf *);
static int gre_ioctl(struct ifnet *, u_long, caddr_t);
static int gre_output(struct ifnet *, struct mbuf *,
const struct sockaddr *, struct route *);
static void gre_updatehdr(struct gre_softc *);
static int gre_set_tunnel(struct ifnet *, struct sockaddr *,
struct sockaddr *);
static void gre_delete_tunnel(struct ifnet *);
SYSCTL_DECL(_net_link);
static SYSCTL_NODE(_net_link, IFT_TUNNEL, 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 VNET_DEFINE(int, max_gre_nesting) = MAX_GRE_NEST;
#define V_max_gre_nesting VNET(max_gre_nesting)
SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET,
&VNET_NAME(max_gre_nesting), 0, "Max nested tunnels");
static void
vnet_gre_init(const void *unused __unused)
{
LIST_INIT(&V_gre_softc_list);
GRE_LIST_LOCK_INIT();
V_gre_cloner = if_clone_simple(grename, gre_clone_create,
gre_clone_destroy, 0);
}
VNET_SYSINIT(vnet_gre_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
vnet_gre_init, NULL);
static void
vnet_gre_uninit(const void *unused __unused)
{
if_clone_detach(V_gre_cloner);
GRE_LIST_LOCK_DESTROY();
}
VNET_SYSUNINIT(vnet_gre_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
vnet_gre_uninit, NULL);
static int
gre_clone_create(struct if_clone *ifc, int unit, caddr_t params)
{
struct gre_softc *sc;
sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
sc->gre_fibnum = curthread->td_proc->p_fibnum;
GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
GRE_LOCK_INIT(sc);
GRE2IFP(sc)->if_softc = sc;
if_initname(GRE2IFP(sc), grename, unit);
GRE2IFP(sc)->if_mtu = GREMTU;
GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
GRE2IFP(sc)->if_output = gre_output;
GRE2IFP(sc)->if_ioctl = gre_ioctl;
GRE2IFP(sc)->if_transmit = gre_transmit;
GRE2IFP(sc)->if_qflush = gre_qflush;
GRE2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
GRE2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
if_attach(GRE2IFP(sc));
bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
GRE_LIST_LOCK();
LIST_INSERT_HEAD(&V_gre_softc_list, sc, gre_list);
GRE_LIST_UNLOCK();
return (0);
}
static void
gre_clone_destroy(struct ifnet *ifp)
{
struct gre_softc *sc;
sx_xlock(&gre_ioctl_sx);
sc = ifp->if_softc;
gre_delete_tunnel(ifp);
GRE_LIST_LOCK();
LIST_REMOVE(sc, gre_list);
GRE_LIST_UNLOCK();
bpfdetach(ifp);
if_detach(ifp);
ifp->if_softc = NULL;
sx_xunlock(&gre_ioctl_sx);
if_free(ifp);
GRE_LOCK_DESTROY(sc);
free(sc, M_GRE);
}
static int
gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
GRE_RLOCK_TRACKER;
struct ifreq *ifr = (struct ifreq *)data;
struct sockaddr *src, *dst;
struct gre_softc *sc;
#ifdef INET
struct sockaddr_in *sin = NULL;
#endif
#ifdef INET6
struct sockaddr_in6 *sin6 = NULL;
#endif
uint32_t opt;
int error;
switch (cmd) {
case SIOCSIFMTU:
/* XXX: */
if (ifr->ifr_mtu < 576)
return (EINVAL);
ifp->if_mtu = ifr->ifr_mtu;
return (0);
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP;
case SIOCSIFFLAGS:
case SIOCADDMULTI:
case SIOCDELMULTI:
return (0);
case GRESADDRS:
case GRESADDRD:
case GREGADDRS:
case GREGADDRD:
case GRESPROTO:
case GREGPROTO:
return (EOPNOTSUPP);
}
src = dst = NULL;
sx_xlock(&gre_ioctl_sx);
sc = ifp->if_softc;
if (sc == NULL) {
error = ENXIO;
goto end;
}
error = 0;
switch (cmd) {
case SIOCSIFPHYADDR:
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
#endif
error = EINVAL;
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
default:
error = EAFNOSUPPORT;
goto end;
}
/* sa_family must be equal */
if (src->sa_family != dst->sa_family ||
src->sa_len != dst->sa_len)
goto end;
/* validate sa_len */
switch (src->sa_family) {
#ifdef INET
case AF_INET:
if (src->sa_len != sizeof(struct sockaddr_in))
goto end;
break;
#endif
#ifdef INET6
case AF_INET6:
if (src->sa_len != sizeof(struct sockaddr_in6))
goto end;
break;
#endif
default:
error = EAFNOSUPPORT;
goto end;
}
/* check sa_family looks sane for the cmd */
error = EAFNOSUPPORT;
switch (cmd) {
#ifdef INET
case SIOCSIFPHYADDR:
if (src->sa_family == AF_INET)
break;
goto end;
#endif
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
if (src->sa_family == AF_INET6)
break;
goto end;
#endif
}
error = EADDRNOTAVAIL;
switch (src->sa_family) {
#ifdef INET
case AF_INET:
if (satosin(src)->sin_addr.s_addr == INADDR_ANY ||
satosin(dst)->sin_addr.s_addr == INADDR_ANY)
goto end;
break;
#endif
#ifdef INET6
case AF_INET6:
if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(src)->sin6_addr)
||
IN6_IS_ADDR_UNSPECIFIED(&satosin6(dst)->sin6_addr))
goto end;
/*
* Check validity of the scope zone ID of the
* addresses, and convert it into the kernel
* internal form if necessary.
*/
error = sa6_embedscope(satosin6(src), 0);
if (error != 0)
goto end;
error = sa6_embedscope(satosin6(dst), 0);
if (error != 0)
goto end;
#endif
}
error = gre_set_tunnel(ifp, src, dst);
break;
case SIOCDIFPHYADDR:
gre_delete_tunnel(ifp);
break;
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
#endif
if (sc->gre_family == 0) {
error = EADDRNOTAVAIL;
break;
}
GRE_RLOCK(sc);
switch (cmd) {
#ifdef INET
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
if (sc->gre_family != AF_INET) {
error = EADDRNOTAVAIL;
break;
}
sin = (struct sockaddr_in *)&ifr->ifr_addr;
memset(sin, 0, sizeof(*sin));
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
break;
#endif
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
if (sc->gre_family != AF_INET6) {
error = EADDRNOTAVAIL;
break;
}
sin6 = (struct sockaddr_in6 *)
&(((struct in6_ifreq *)data)->ifr_addr);
memset(sin6, 0, sizeof(*sin6));
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(*sin6);
break;
#endif
}
if (error == 0) {
switch (cmd) {
#ifdef INET
case SIOCGIFPSRCADDR:
sin->sin_addr = sc->gre_oip.ip_src;
break;
case SIOCGIFPDSTADDR:
sin->sin_addr = sc->gre_oip.ip_dst;
break;
#endif
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
sin6->sin6_addr = sc->gre_oip6.ip6_src;
break;
case SIOCGIFPDSTADDR_IN6:
sin6->sin6_addr = sc->gre_oip6.ip6_dst;
break;
#endif
}
}
GRE_RUNLOCK(sc);
if (error != 0)
break;
switch (cmd) {
#ifdef INET
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
error = prison_if(curthread->td_ucred,
(struct sockaddr *)sin);
if (error != 0)
memset(sin, 0, sizeof(*sin));
break;
#endif
#ifdef INET6
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
error = prison_if(curthread->td_ucred,
(struct sockaddr *)sin6);
if (error == 0)
error = sa6_recoverscope(sin6);
if (error != 0)
memset(sin6, 0, sizeof(*sin6));
#endif
}
break;
case SIOCGTUNFIB:
ifr->ifr_fib = sc->gre_fibnum;
break;
case SIOCSTUNFIB:
if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
break;
if (ifr->ifr_fib >= rt_numfibs)
error = EINVAL;
else
sc->gre_fibnum = ifr->ifr_fib;
break;
case GRESKEY:
if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
break;
if ((error = copyin(ifr->ifr_data, &opt, sizeof(opt))) != 0)
break;
if (sc->gre_key != opt) {
GRE_WLOCK(sc);
sc->gre_key = opt;
gre_updatehdr(sc);
GRE_WUNLOCK(sc);
}
break;
case GREGKEY:
error = copyout(&sc->gre_key, ifr->ifr_data,
sizeof(sc->gre_key));
break;
case GRESOPTS:
if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
break;
if ((error = copyin(ifr->ifr_data, &opt, sizeof(opt))) != 0)
break;
if (opt & ~GRE_OPTMASK)
error = EINVAL;
else {
if (sc->gre_options != opt) {
GRE_WLOCK(sc);
sc->gre_options = opt;
gre_updatehdr(sc);
GRE_WUNLOCK(sc);
}
}
break;
case GREGOPTS:
error = copyout(&sc->gre_options, ifr->ifr_data,
sizeof(sc->gre_options));
break;
default:
error = EINVAL;
break;
}
end:
sx_xunlock(&gre_ioctl_sx);
return (error);
}
static void
gre_updatehdr(struct gre_softc *sc)
{
struct grehdr *gh = NULL;
uint32_t *opts;
uint16_t flags;
GRE_WLOCK_ASSERT(sc);
switch (sc->gre_family) {
#ifdef INET
case AF_INET:
sc->gre_hlen = sizeof(struct greip);
sc->gre_oip.ip_v = IPPROTO_IPV4;
sc->gre_oip.ip_hl = sizeof(struct ip) >> 2;
sc->gre_oip.ip_p = IPPROTO_GRE;
gh = &sc->gre_gihdr->gi_gre;
break;
#endif
#ifdef INET6
case AF_INET6:
sc->gre_hlen = sizeof(struct greip6);
sc->gre_oip6.ip6_vfc = IPV6_VERSION;
sc->gre_oip6.ip6_nxt = IPPROTO_GRE;
gh = &sc->gre_gi6hdr->gi6_gre;
break;
#endif
default:
return;
}
flags = 0;
opts = gh->gre_opts;
if (sc->gre_options & GRE_ENABLE_CSUM) {
flags |= GRE_FLAGS_CP;
sc->gre_hlen += 2 * sizeof(uint16_t);
*opts++ = 0;
}
if (sc->gre_key != 0) {
flags |= GRE_FLAGS_KP;
sc->gre_hlen += sizeof(uint32_t);
*opts++ = htonl(sc->gre_key);
}
if (sc->gre_options & GRE_ENABLE_SEQ) {
flags |= GRE_FLAGS_SP;
sc->gre_hlen += sizeof(uint32_t);
*opts++ = 0;
} else
sc->gre_oseq = 0;
gh->gre_flags = htons(flags);
}
static void
gre_detach(struct gre_softc *sc)
{
sx_assert(&gre_ioctl_sx, SA_XLOCKED);
if (sc->gre_ecookie != NULL)
encap_detach(sc->gre_ecookie);
sc->gre_ecookie = NULL;
}
static int
gre_set_tunnel(struct ifnet *ifp, struct sockaddr *src,
struct sockaddr *dst)
{
struct gre_softc *sc, *tsc;
#ifdef INET6
struct ip6_hdr *ip6;
#endif
#ifdef INET
struct ip *ip;
#endif
void *hdr;
int error;
sx_assert(&gre_ioctl_sx, SA_XLOCKED);
GRE_LIST_LOCK();
sc = ifp->if_softc;
LIST_FOREACH(tsc, &V_gre_softc_list, gre_list) {
if (tsc == sc || tsc->gre_family != src->sa_family)
continue;
#ifdef INET
if (tsc->gre_family == AF_INET &&
tsc->gre_oip.ip_src.s_addr ==
satosin(src)->sin_addr.s_addr &&
tsc->gre_oip.ip_dst.s_addr ==
satosin(dst)->sin_addr.s_addr) {
GRE_LIST_UNLOCK();
return (EADDRNOTAVAIL);
}
#endif
#ifdef INET6
if (tsc->gre_family == AF_INET6 &&
IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_src,
&satosin6(src)->sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_dst,
&satosin6(dst)->sin6_addr)) {
GRE_LIST_UNLOCK();
return (EADDRNOTAVAIL);
}
#endif
}
GRE_LIST_UNLOCK();
switch (src->sa_family) {
#ifdef INET
case AF_INET:
hdr = ip = malloc(sizeof(struct greip) +
3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO);
ip->ip_src = satosin(src)->sin_addr;
ip->ip_dst = satosin(dst)->sin_addr;
break;
#endif
#ifdef INET6
case AF_INET6:
hdr = ip6 = malloc(sizeof(struct greip6) +
3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO);
ip6->ip6_src = satosin6(src)->sin6_addr;
ip6->ip6_dst = satosin6(dst)->sin6_addr;
break;
#endif
default:
return (EAFNOSUPPORT);
}
if (sc->gre_family != 0)
gre_detach(sc);
GRE_WLOCK(sc);
if (sc->gre_family != 0)
free(sc->gre_hdr, M_GRE);
sc->gre_family = src->sa_family;
sc->gre_hdr = hdr;
sc->gre_oseq = 0;
sc->gre_iseq = UINT32_MAX;
gre_updatehdr(sc);
GRE_WUNLOCK(sc);
error = 0;
switch (src->sa_family) {
#ifdef INET
case AF_INET:
error = in_gre_attach(sc);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gre_attach(sc);
break;
#endif
}
if (error == 0) {
ifp->if_drv_flags |= IFF_DRV_RUNNING;
if_link_state_change(ifp, LINK_STATE_UP);
}
return (error);
}
static void
gre_delete_tunnel(struct ifnet *ifp)
{
struct gre_softc *sc = ifp->if_softc;
int family;
GRE_WLOCK(sc);
family = sc->gre_family;
sc->gre_family = 0;
GRE_WUNLOCK(sc);
if (family != 0) {
gre_detach(sc);
free(sc->gre_hdr, M_GRE);
}
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
if_link_state_change(ifp, LINK_STATE_DOWN);
}
int
gre_input(struct mbuf **mp, int *offp, int proto)
{
struct gre_softc *sc;
struct grehdr *gh;
struct ifnet *ifp;
struct mbuf *m;
uint32_t *opts;
#ifdef notyet
uint32_t key;
#endif
uint16_t flags;
int hlen, isr, af;
m = *mp;
sc = encap_getarg(m);
KASSERT(sc != NULL, ("encap_getarg returned NULL"));
ifp = GRE2IFP(sc);
hlen = *offp + sizeof(struct grehdr) + 4 * sizeof(uint32_t);
if (m->m_pkthdr.len < hlen)
goto drop;
if (m->m_len < hlen) {
m = m_pullup(m, hlen);
if (m == NULL)
goto drop;
}
gh = (struct grehdr *)mtodo(m, *offp);
flags = ntohs(gh->gre_flags);
if (flags & ~GRE_FLAGS_MASK)
goto drop;
opts = gh->gre_opts;
hlen = 2 * sizeof(uint16_t);
if (flags & GRE_FLAGS_CP) {
/* reserved1 field must be zero */
if (((uint16_t *)opts)[1] != 0)
goto drop;
if (in_cksum_skip(m, m->m_pkthdr.len, *offp) != 0)
goto drop;
hlen += 2 * sizeof(uint16_t);
opts++;
}
if (flags & GRE_FLAGS_KP) {
#ifdef notyet
/*
* XXX: The current implementation uses the key only for outgoing
* packets. But we can check the key value here, or even in the
* encapcheck function.
*/
key = ntohl(*opts);
#endif
hlen += sizeof(uint32_t);
opts++;
}
#ifdef notyet
} else
key = 0;
if (sc->gre_key != 0 && (key != sc->gre_key || key != 0))
goto drop;
#endif
if (flags & GRE_FLAGS_SP) {
#ifdef notyet
seq = ntohl(*opts);
#endif
hlen += sizeof(uint32_t);
}
switch (ntohs(gh->gre_proto)) {
case ETHERTYPE_WCCP:
/*
* For WCCP skip an additional 4 bytes if after GRE header
* doesn't follow an IP header.
*/
if (flags == 0 && (*(uint8_t *)gh->gre_opts & 0xF0) != 0x40)
hlen += sizeof(uint32_t);
/* FALLTHROUGH */
case ETHERTYPE_IP:
isr = NETISR_IP;
af = AF_INET;
break;
case ETHERTYPE_IPV6:
isr = NETISR_IPV6;
af = AF_INET6;
break;
default:
goto drop;
}
m_adj(m, *offp + hlen);
m_clrprotoflags(m);
m->m_pkthdr.rcvif = ifp;
M_SETFIB(m, ifp->if_fib);
#ifdef MAC
mac_ifnet_create_mbuf(ifp, m);
#endif
BPF_MTAP2(ifp, &af, sizeof(af), m);
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
if ((ifp->if_flags & IFF_MONITOR) != 0)
m_freem(m);
else
netisr_dispatch(isr, m);
return (IPPROTO_DONE);
drop:
if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
m_freem(m);
return (IPPROTO_DONE);
}
#define MTAG_GRE 1307983903
static int
gre_check_nesting(struct ifnet *ifp, struct mbuf *m)
{
struct m_tag *mtag;
int count;
count = 1;
mtag = NULL;
while ((mtag = m_tag_locate(m, MTAG_GRE, 0, mtag)) != NULL) {
if (*(struct ifnet **)(mtag + 1) == ifp) {
log(LOG_NOTICE, "%s: loop detected\n", ifp->if_xname);
return (EIO);
}
count++;
}
if (count > V_max_gre_nesting) {
log(LOG_NOTICE,
"%s: if_output recursively called too many times(%d)\n",
ifp->if_xname, count);
return (EIO);
}
mtag = m_tag_alloc(MTAG_GRE, 0, sizeof(struct ifnet *), M_NOWAIT);
if (mtag == NULL)
return (ENOMEM);
*(struct ifnet **)(mtag + 1) = ifp;
m_tag_prepend(m, mtag);
return (0);
}
static int
gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *ro)
{
uint32_t af;
int error;
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error != 0)
goto drop;
#endif
if ((ifp->if_flags & IFF_MONITOR) != 0 ||
(ifp->if_flags & IFF_UP) == 0) {
error = ENETDOWN;
goto drop;
}
error = gre_check_nesting(ifp, m);
if (error != 0)
goto drop;
m->m_flags &= ~(M_BCAST|M_MCAST);
if (dst->sa_family == AF_UNSPEC)
bcopy(dst->sa_data, &af, sizeof(af));
else
af = dst->sa_family;
BPF_MTAP2(ifp, &af, sizeof(af), m);
m->m_pkthdr.csum_data = af; /* save af for if_transmit */
return (ifp->if_transmit(ifp, m));
drop:
m_freem(m);
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
return (error);
}
static void
gre_setseqn(struct grehdr *gh, uint32_t seq)
{
uint32_t *opts;
uint16_t flags;
opts = gh->gre_opts;
flags = ntohs(gh->gre_flags);
KASSERT((flags & GRE_FLAGS_SP) != 0,
("gre_setseqn called, but GRE_FLAGS_SP isn't set "));
if (flags & GRE_FLAGS_CP)
opts++;
if (flags & GRE_FLAGS_KP)
opts++;
*opts = htonl(seq);
}
static int
gre_transmit(struct ifnet *ifp, struct mbuf *m)
{
GRE_RLOCK_TRACKER;
struct gre_softc *sc;
struct grehdr *gh;
uint32_t iaf, oaf, oseq;
int error, hlen, olen, plen;
int want_seq, want_csum;
plen = 0;
sc = ifp->if_softc;
if (sc == NULL) {
error = ENETDOWN;
m_freem(m);
goto drop;
}
GRE_RLOCK(sc);
if (sc->gre_family == 0) {
GRE_RUNLOCK(sc);
error = ENETDOWN;
m_freem(m);
goto drop;
}
iaf = m->m_pkthdr.csum_data;
oaf = sc->gre_family;
hlen = sc->gre_hlen;
want_seq = (sc->gre_options & GRE_ENABLE_SEQ) != 0;
if (want_seq)
oseq = sc->gre_oseq++; /* XXX */
else
oseq = 0; /* Make compiler happy. */
want_csum = (sc->gre_options & GRE_ENABLE_CSUM) != 0;
M_SETFIB(m, sc->gre_fibnum);
M_PREPEND(m, hlen, M_NOWAIT);
if (m == NULL) {
GRE_RUNLOCK(sc);
error = ENOBUFS;
goto drop;
}
bcopy(sc->gre_hdr, mtod(m, void *), hlen);
GRE_RUNLOCK(sc);
switch (oaf) {
#ifdef INET
case AF_INET:
olen = sizeof(struct ip);
break;
#endif
#ifdef INET6
case AF_INET6:
olen = sizeof(struct ip6_hdr);
break;
#endif
default:
error = ENETDOWN;
goto drop;
}
gh = (struct grehdr *)mtodo(m, olen);
switch (iaf) {
#ifdef INET
case AF_INET:
gh->gre_proto = htons(ETHERTYPE_IP);
break;
#endif
#ifdef INET6
case AF_INET6:
gh->gre_proto = htons(ETHERTYPE_IPV6);
break;
#endif
default:
error = ENETDOWN;
goto drop;
}
if (want_seq)
gre_setseqn(gh, oseq);
if (want_csum) {
*(uint16_t *)gh->gre_opts = in_cksum_skip(m,
m->m_pkthdr.len, olen);
}
plen = m->m_pkthdr.len - hlen;
switch (oaf) {
#ifdef INET
case AF_INET:
error = in_gre_output(m, iaf, hlen);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gre_output(m, iaf, hlen);
break;
#endif
default:
m_freem(m);
error = ENETDOWN;
}
drop:
if (error)
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
else {
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
}
return (error);
}
static void
gre_qflush(struct ifnet *ifp __unused)
{
}
static int
gremodevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
case MOD_UNLOAD:
break;
default:
return (EOPNOTSUPP);
}
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);