ip6_gre.c

#include <sys/systm.h>
#include <sys/kpi_mbuf.h>
#include <sys/sysctl.h>
#include <sys/socket.h>

#include <net/bpf.h>
#include <net/kpi_protocol.h>
#include <net/kpi_interface.h>

#include <net/if.h>
#include <net/ethernet.h>

#include <netinet/kpi_ipfilter.h>

#include "kernel_build.h"
#include "gre_ip_encap.h"
#include "if_gre.h"


static int ip6_gre_hlim = IPV6_DEFHLIM;

SYSCTL_DECL(_net_gre);
SYSCTL_INT(_net_gre, OID_AUTO, hlim, CTLTYPE_INT | CTLFLAG_RW, &ip6_gre_hlim, 0, "Default hop limit for encapsulated packets");


static int
in6_gre_encapcheck(const mbuf_t m, int off, int proto, void *arg)
{
	struct gre_softc *sc;
	struct ip6_hdr *ip6;

	sc = (struct gre_softc *)arg;
	if ((ifnet_flags(sc->gre_ifp) & IFF_UP) == 0)
		return 0;

	//M_ASSERTPKTHDR(m);
	/*
	 * We expect that payload contains at least IPv4
	 * or IPv6 packet.
	 */
	if (mbuf_pkthdr_len(m) < sizeof(struct greip6) + sizeof(struct ip))
		return 0;

	GRE_RLOCK(sc);
	if (sc->gre_family == 0)
		goto bad;

	KASSERT(sc->gre_family == AF_INET6,
		("wrong gre_family: %d", sc->gre_family));

	ip6 = mtod(m, struct ip6_hdr *);
	if (!IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, &ip6->ip6_dst) ||
	    !IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, &ip6->ip6_src))
		goto bad;

	GRE_RUNLOCK(sc);
	return (128 * 2);
bad:
	GRE_RUNLOCK(sc);
	return 0;
}


errno_t
in6_gre_output(mbuf_t m, int af, int hlen)
{
	struct greip6 *gi6;
	errno_t err;

	gi6 = mtod(m, struct greip6 *);

	//gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim;
	gi6->gi6_ip6.ip6_hlim = ((unsigned int)ip6_gre_hlim) & 0xff;


	err = ipf_inject_output(m, NULL, NULL);

	return err;
}


errno_t
in6_gre_attach(struct gre_softc *sc)
{
	KASSERT(sc->gre_ecookie == NULL, ("gre_ecookie isn't NULL"));
	sc->gre_ecookie = (void *)gre_encap_attach_func(AF_INET6, IPPROTO_GRE,
					    in6_gre_encapcheck, gre_input, sc);
	if (sc->gre_ecookie == NULL)
		return (EEXIST);
	return (0);
}