freebsd-skq/sys/netinet6/ip6_gre.c
Andrey V. Elsukov f325335caf Overhaul if_gre(4).
Split it into two modules: if_gre(4) for GRE encapsulation and
if_me(4) for minimal encapsulation within IP.

gre(4) changes:
* convert to if_transmit;
* rework locking: protect access to softc with rmlock,
  protect from concurrent ioctls with sx lock;
* correct interface accounting for outgoing datagramms (count only payload size);
* implement generic support for using IPv6 as delivery header;
* make implementation conform to the RFC 2784 and partially to RFC 2890;
* add support for GRE checksums - calculate for outgoing datagramms and check
  for inconming datagramms;
* add support for sending sequence number in GRE header;
* remove support of cached routes. This fixes problem, when gre(4) doesn't
  work at system startup. But this also removes support for having tunnels with
  the same addresses for inner and outer header.
* deprecate support for various GREXXX ioctls, that doesn't used in FreeBSD.
  Use our standard ioctls for tunnels.

me(4):
* implementation conform to RFC 2004;
* use if_transmit;
* use the same locking model as gre(4);

PR:		164475
Differential Revision:	D1023
No objections from:	net@
Relnotes:	yes
Sponsored by:	Yandex LLC
2014-11-07 19:13:19 +00:00

152 lines
4.1 KiB
C

/*-
* Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/protosw.h>
#include <sys/malloc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <net/ethernet.h>
#include <netinet/ip.h>
#endif
#include <netinet/ip_encap.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_var.h>
#include <net/if_gre.h>
extern struct domain inet6domain;
extern int gre_input(struct mbuf **, int *, int);
int in6_gre_attach(struct gre_softc *);
int in6_gre_output(struct mbuf *, int, int);
struct protosw in6_gre_protosw = {
.pr_type = SOCK_RAW,
.pr_domain = &inet6domain,
.pr_protocol = IPPROTO_GRE,
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_input = gre_input,
.pr_output = rip6_output,
.pr_ctloutput = rip6_ctloutput,
.pr_usrreqs = &rip6_usrreqs
};
VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM;
#define V_ip6_gre_hlim VNET(ip6_gre_hlim)
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets");
static int
in6_gre_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
{
GRE_RLOCK_TRACKER;
struct gre_softc *sc;
struct ip6_hdr *ip6;
sc = (struct gre_softc *)arg;
if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0)
return (0);
M_ASSERTPKTHDR(m);
/*
* We expect that payload contains at least IPv4
* or IPv6 packet.
*/
if (m->m_pkthdr.len < sizeof(struct greip6) +
#ifdef INET
sizeof(struct ip))
#else
sizeof(struct ip6_hdr))
#endif
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);
}
int
in6_gre_output(struct mbuf *m, int af, int hlen)
{
struct greip6 *gi6;
gi6 = mtod(m, struct greip6 *);
gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim;
return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL));
}
int
in6_gre_attach(struct gre_softc *sc)
{
KASSERT(sc->gre_ecookie == NULL, ("gre_ecookie isn't NULL"));
sc->gre_ecookie = encap_attach_func(AF_INET6, IPPROTO_GRE,
in6_gre_encapcheck, &in6_gre_protosw, sc);
if (sc->gre_ecookie == NULL)
return (EEXIST);
return (0);
}