freebsd-dev/sys/net/if_gre.c
Zhenlei Huang 62e1a437f3 routing: Allow using IPv6 next-hops for IPv4 routes (RFC 5549).
Implement kernel support for RFC 5549/8950.

* Relax control plane restrictions and allow specifying IPv6 gateways
 for IPv4 routes. This behavior is controlled by the
 net.route.rib_route_ipv6_nexthop sysctl (on by default).

* Always pass final destination in ro->ro_dst in ip_forward().

* Use ro->ro_dst to exract packet family inside if_output() routines.
 Consistently use RO_GET_FAMILY() macro to handle ro=NULL case.

* Pass extracted family to nd6_resolve() to get the LLE with proper encap.
 It leverages recent lltable changes committed in c541bd368f.

Presence of the functionality can be checked using ipv4_rfc5549_support feature(3).
Example usage:
  route add -net 192.0.0.0/24 -inet6 fe80::5054:ff:fe14:e319%vtnet0

Differential Revision: https://reviews.freebsd.org/D30398
MFC after:	2 weeks
2021-08-22 22:56:08 +00:00

833 lines
19 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* Copyright (c) 2014, 2018 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 "opt_rss.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.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>
#include <netinet/in_pcb.h>
#ifdef INET
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#ifdef RSS
#include <netinet/in_rss.h>
#endif
#endif
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#ifdef RSS
#include <netinet6/in6_rss.h>
#endif
#endif
#include <netinet/ip_encap.h>
#include <netinet/udp.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";
MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation");
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 *);
VNET_DEFINE_STATIC(struct if_clone *, gre_cloner);
#define V_gre_cloner VNET(gre_cloner)
#ifdef VIMAGE
static void gre_reassign(struct ifnet *, struct vnet *, char *);
#endif
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_delete_tunnel(struct gre_softc *);
SYSCTL_DECL(_net_link);
static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW | CTLFLAG_MPSAFE, 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
VNET_DEFINE_STATIC(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)
{
V_gre_cloner = if_clone_simple(grename, gre_clone_create,
gre_clone_destroy, 0);
#ifdef INET
in_gre_init();
#endif
#ifdef INET6
in6_gre_init();
#endif
}
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);
#ifdef INET
in_gre_uninit();
#endif
#ifdef INET6
in6_gre_uninit();
#endif
/* XXX: epoch_call drain */
}
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);
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;
#ifdef VIMAGE
GRE2IFP(sc)->if_reassign = gre_reassign;
#endif
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));
return (0);
}
#ifdef VIMAGE
static void
gre_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
char *unused __unused)
{
struct gre_softc *sc;
sx_xlock(&gre_ioctl_sx);
sc = ifp->if_softc;
if (sc != NULL)
gre_delete_tunnel(sc);
sx_xunlock(&gre_ioctl_sx);
}
#endif /* VIMAGE */
static void
gre_clone_destroy(struct ifnet *ifp)
{
struct gre_softc *sc;
sx_xlock(&gre_ioctl_sx);
sc = ifp->if_softc;
gre_delete_tunnel(sc);
bpfdetach(ifp);
if_detach(ifp);
ifp->if_softc = NULL;
sx_xunlock(&gre_ioctl_sx);
GRE_WAIT();
if_free(ifp);
free(sc, M_GRE);
}
static int
gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr = (struct ifreq *)data;
struct gre_softc *sc;
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);
}
sx_xlock(&gre_ioctl_sx);
sc = ifp->if_softc;
if (sc == NULL) {
error = ENXIO;
goto end;
}
error = 0;
switch (cmd) {
case SIOCDIFPHYADDR:
if (sc->gre_family == 0)
break;
gre_delete_tunnel(sc);
break;
#ifdef INET
case SIOCSIFPHYADDR:
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
error = in_gre_ioctl(sc, cmd, data);
break;
#endif
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
error = in6_gre_ioctl(sc, cmd, data);
break;
#endif
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:
case GRESOPTS:
case GRESPORT:
if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
break;
if ((error = copyin(ifr_data_get_ptr(ifr), &opt,
sizeof(opt))) != 0)
break;
if (cmd == GRESKEY) {
if (sc->gre_key == opt)
break;
} else if (cmd == GRESOPTS) {
if (opt & ~GRE_OPTMASK) {
error = EINVAL;
break;
}
if (sc->gre_options == opt)
break;
} else if (cmd == GRESPORT) {
if (opt != 0 && (opt < V_ipport_hifirstauto ||
opt > V_ipport_hilastauto)) {
error = EINVAL;
break;
}
if (sc->gre_port == opt)
break;
if ((sc->gre_options & GRE_UDPENCAP) == 0) {
/*
* UDP encapsulation is not enabled, thus
* there is no need to reattach softc.
*/
sc->gre_port = opt;
break;
}
}
switch (sc->gre_family) {
#ifdef INET
case AF_INET:
error = in_gre_setopts(sc, cmd, opt);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gre_setopts(sc, cmd, opt);
break;
#endif
default:
/*
* Tunnel is not yet configured.
* We can just change any parameters.
*/
if (cmd == GRESKEY)
sc->gre_key = opt;
if (cmd == GRESOPTS)
sc->gre_options = opt;
if (cmd == GRESPORT)
sc->gre_port = opt;
break;
}
/*
* XXX: Do we need to initiate change of interface
* state here?
*/
break;
case GREGKEY:
error = copyout(&sc->gre_key, ifr_data_get_ptr(ifr),
sizeof(sc->gre_key));
break;
case GREGOPTS:
error = copyout(&sc->gre_options, ifr_data_get_ptr(ifr),
sizeof(sc->gre_options));
break;
case GREGPORT:
error = copyout(&sc->gre_port, ifr_data_get_ptr(ifr),
sizeof(sc->gre_port));
break;
default:
error = EINVAL;
break;
}
if (error == 0 && sc->gre_family != 0) {
if (
#ifdef INET
cmd == SIOCSIFPHYADDR ||
#endif
#ifdef INET6
cmd == SIOCSIFPHYADDR_IN6 ||
#endif
0) {
if_link_state_change(ifp, LINK_STATE_UP);
}
}
end:
sx_xunlock(&gre_ioctl_sx);
return (error);
}
static void
gre_delete_tunnel(struct gre_softc *sc)
{
struct gre_socket *gs;
sx_assert(&gre_ioctl_sx, SA_XLOCKED);
if (sc->gre_family != 0) {
CK_LIST_REMOVE(sc, chain);
CK_LIST_REMOVE(sc, srchash);
GRE_WAIT();
free(sc->gre_hdr, M_GRE);
sc->gre_family = 0;
}
/*
* If this Tunnel was the last one that could use UDP socket,
* we should unlink socket from hash table and close it.
*/
if ((gs = sc->gre_so) != NULL && CK_LIST_EMPTY(&gs->list)) {
CK_LIST_REMOVE(gs, chain);
soclose(gs->so);
NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx);
sc->gre_so = NULL;
}
GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
if_link_state_change(GRE2IFP(sc), LINK_STATE_DOWN);
}
struct gre_list *
gre_hashinit(void)
{
struct gre_list *hash;
int i;
hash = malloc(sizeof(struct gre_list) * GRE_HASH_SIZE,
M_GRE, M_WAITOK);
for (i = 0; i < GRE_HASH_SIZE; i++)
CK_LIST_INIT(&hash[i]);
return (hash);
}
void
gre_hashdestroy(struct gre_list *hash)
{
free(hash, M_GRE);
}
void
gre_sofree(epoch_context_t ctx)
{
struct gre_socket *gs;
gs = __containerof(ctx, struct gre_socket, epoch_ctx);
free(gs, M_GRE);
}
static __inline uint16_t
gre_cksum_add(uint16_t sum, uint16_t a)
{
uint16_t res;
res = sum + a;
return (res + (res < a));
}
void
gre_update_udphdr(struct gre_softc *sc, struct udphdr *udp, uint16_t csum)
{
sx_assert(&gre_ioctl_sx, SA_XLOCKED);
MPASS(sc->gre_options & GRE_UDPENCAP);
udp->uh_dport = htons(GRE_UDPPORT);
udp->uh_sport = htons(sc->gre_port);
udp->uh_sum = csum;
udp->uh_ulen = 0;
}
void
gre_update_hdr(struct gre_softc *sc, struct grehdr *gh)
{
uint32_t *opts;
uint16_t flags;
sx_assert(&gre_ioctl_sx, SA_XLOCKED);
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);
}
int
gre_input(struct mbuf *m, int off, int proto, void *arg)
{
struct gre_softc *sc = arg;
struct grehdr *gh;
struct ifnet *ifp;
uint32_t *opts;
#ifdef notyet
uint32_t key;
#endif
uint16_t flags;
int hlen, isr, af;
ifp = GRE2IFP(sc);
hlen = off + 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, off);
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, off) != 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, off + 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);
}
static int
gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *ro)
{
uint32_t af;
if (dst->sa_family == AF_UNSPEC)
bcopy(dst->sa_data, &af, sizeof(af));
else
af = RO_GET_FAMILY(ro, dst);
/*
* Now save the af in the inbound pkt csum data, this is a cheat since
* we are using the inbound csum_data field to carry the af over to
* the gre_transmit() routine, avoiding using yet another mtag.
*/
m->m_pkthdr.csum_data = af;
return (ifp->if_transmit(ifp, m));
}
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 uint32_t
gre_flowid(struct gre_softc *sc, struct mbuf *m, uint32_t af)
{
uint32_t flowid = 0;
if ((sc->gre_options & GRE_UDPENCAP) == 0 || sc->gre_port != 0)
return (flowid);
switch (af) {
#ifdef INET
case AF_INET:
#ifdef RSS
flowid = rss_hash_ip4_2tuple(mtod(m, struct ip *)->ip_src,
mtod(m, struct ip *)->ip_dst);
break;
#endif
flowid = mtod(m, struct ip *)->ip_src.s_addr ^
mtod(m, struct ip *)->ip_dst.s_addr;
break;
#endif
#ifdef INET6
case AF_INET6:
#ifdef RSS
flowid = rss_hash_ip6_2tuple(
&mtod(m, struct ip6_hdr *)->ip6_src,
&mtod(m, struct ip6_hdr *)->ip6_dst);
break;
#endif
flowid = mtod(m, struct ip6_hdr *)->ip6_src.s6_addr32[3] ^
mtod(m, struct ip6_hdr *)->ip6_dst.s6_addr32[3];
break;
#endif
default:
break;
}
return (flowid);
}
#define MTAG_GRE 1307983903
static int
gre_transmit(struct ifnet *ifp, struct mbuf *m)
{
GRE_RLOCK_TRACKER;
struct gre_softc *sc;
struct grehdr *gh;
struct udphdr *uh;
uint32_t af, flowid;
int error, len;
uint16_t proto;
len = 0;
GRE_RLOCK();
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error) {
m_freem(m);
goto drop;
}
#endif
error = ENETDOWN;
sc = ifp->if_softc;
if ((ifp->if_flags & IFF_MONITOR) != 0 ||
(ifp->if_flags & IFF_UP) == 0 ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
sc->gre_family == 0 ||
(error = if_tunnel_check_nesting(ifp, m, MTAG_GRE,
V_max_gre_nesting)) != 0) {
m_freem(m);
goto drop;
}
af = m->m_pkthdr.csum_data;
BPF_MTAP2(ifp, &af, sizeof(af), m);
m->m_flags &= ~(M_BCAST|M_MCAST);
flowid = gre_flowid(sc, m, af);
M_SETFIB(m, sc->gre_fibnum);
M_PREPEND(m, sc->gre_hlen, M_NOWAIT);
if (m == NULL) {
error = ENOBUFS;
goto drop;
}
bcopy(sc->gre_hdr, mtod(m, void *), sc->gre_hlen);
/* Determine GRE proto */
switch (af) {
#ifdef INET
case AF_INET:
proto = htons(ETHERTYPE_IP);
break;
#endif
#ifdef INET6
case AF_INET6:
proto = htons(ETHERTYPE_IPV6);
break;
#endif
default:
m_freem(m);
error = ENETDOWN;
goto drop;
}
/* Determine offset of GRE header */
switch (sc->gre_family) {
#ifdef INET
case AF_INET:
len = sizeof(struct ip);
break;
#endif
#ifdef INET6
case AF_INET6:
len = sizeof(struct ip6_hdr);
break;
#endif
default:
m_freem(m);
error = ENETDOWN;
goto drop;
}
if (sc->gre_options & GRE_UDPENCAP) {
uh = (struct udphdr *)mtodo(m, len);
uh->uh_sport |= htons(V_ipport_hifirstauto) |
(flowid >> 16) | (flowid & 0xFFFF);
uh->uh_sport = htons(ntohs(uh->uh_sport) %
V_ipport_hilastauto);
uh->uh_ulen = htons(m->m_pkthdr.len - len);
uh->uh_sum = gre_cksum_add(uh->uh_sum,
htons(m->m_pkthdr.len - len + IPPROTO_UDP));
m->m_pkthdr.csum_flags = sc->gre_csumflags;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
len += sizeof(struct udphdr);
}
gh = (struct grehdr *)mtodo(m, len);
gh->gre_proto = proto;
if (sc->gre_options & GRE_ENABLE_SEQ)
gre_setseqn(gh, sc->gre_oseq++);
if (sc->gre_options & GRE_ENABLE_CSUM) {
*(uint16_t *)gh->gre_opts = in_cksum_skip(m,
m->m_pkthdr.len, len);
}
len = m->m_pkthdr.len - len;
switch (sc->gre_family) {
#ifdef INET
case AF_INET:
error = in_gre_output(m, af, sc->gre_hlen);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gre_output(m, af, sc->gre_hlen, flowid);
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, len);
}
GRE_RUNLOCK();
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);