freebsd-dev/sys/net/if_gre.h
Andrey V. Elsukov 6d8fdfa9d5 Rework IP encapsulation handling code.
Currently it has several disadvantages:
- it uses single mutex to protect internal structures. It is used by
  data- and control- path, thus there are no parallelism at all.
- it uses single list to keep encap handlers for both INET and INET6
  families.
- struct encaptab keeps unneeded information (src, dst, masks, protosw),
  that isn't used by code in the source tree.
- matches are prioritized and when many tunneling interfaces are
  registered, encapcheck handler of each interface is invoked for each
  packet. The search takes O(n) for n interfaces. All this work is done
  with exclusive lock held.

What this patch includes:
- the datapath is converted to be lockless using epoch(9) KPI.
- struct encaptab now linked using CK_LIST.
- all unused fields removed from struct encaptab. Several new fields
  addedr: min_length is the minimum packet length, that encapsulation
  handler expects to see; exact_match is maximum number of bits, that
  can return an encapsulation handler, when it wants to consume a packet.
- IPv6 and IPv4 handlers are stored in separate lists;
- added new "encap_lookup_t" method, that will be used later. It is
  targeted to speedup lookup of needed interface, when gif(4)/gre(4) have
  many interfaces.
- the need to use protosw structure is eliminated. The only pr_input
  method was used from this structure, so I don't see the need to keep
  using it.
- encap_input_t method changed to avoid using mbuf tags to store softc
  pointer. Now it is passed directly trough encap_input_t method.
  encap_getarg() funtions is removed.
- all sockaddr structures and code that uses them removed. We don't have
  any code in the tree that uses them. All consumers use encap_attach_func()
  method, that relies on invoking of encapcheck() to determine the needed
  handler.
- introduced struct encap_config, it contains parameters of encap handler
  that is going to be registered by encap_attach() function.
- encap handlers are stored in lists ordered by exact_match value, thus
  handlers that need more bits to match will be checked first, and if
  encapcheck method returns exact_match value, the search will be stopped.
- all current consumers changed to use new KPI.

Reviewed by:	mmacy
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D15617
2018-06-05 20:51:01 +00:00

138 lines
4.5 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>
*
* 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.h,v 1.13 2003/11/10 08:51:52 wiz Exp $
* $FreeBSD$
*/
#ifndef _NET_IF_GRE_H_
#define _NET_IF_GRE_H_
#ifdef _KERNEL
/* GRE header according to RFC 2784 and RFC 2890 */
struct grehdr {
uint16_t gre_flags; /* GRE flags */
#define GRE_FLAGS_CP 0x8000 /* checksum present */
#define GRE_FLAGS_KP 0x2000 /* key present */
#define GRE_FLAGS_SP 0x1000 /* sequence present */
#define GRE_FLAGS_MASK (GRE_FLAGS_CP|GRE_FLAGS_KP|GRE_FLAGS_SP)
uint16_t gre_proto; /* protocol type */
uint32_t gre_opts[0]; /* optional fields */
} __packed;
#ifdef INET
struct greip {
struct ip gi_ip;
struct grehdr gi_gre;
} __packed;
#endif
#ifdef INET6
struct greip6 {
struct ip6_hdr gi6_ip6;
struct grehdr gi6_gre;
} __packed;
#endif
struct gre_softc {
struct ifnet *gre_ifp;
LIST_ENTRY(gre_softc) gre_list;
struct rmlock gre_lock;
int gre_family; /* AF of delivery header */
uint32_t gre_iseq;
uint32_t gre_oseq;
uint32_t gre_key;
uint32_t gre_options;
u_int gre_fibnum;
u_int gre_hlen; /* header size */
union {
void *hdr;
#ifdef INET
struct greip *gihdr;
#endif
#ifdef INET6
struct greip6 *gi6hdr;
#endif
} gre_uhdr;
const struct encaptab *gre_ecookie;
};
#define GRE2IFP(sc) ((sc)->gre_ifp)
#define GRE_LOCK_INIT(sc) rm_init(&(sc)->gre_lock, "gre softc")
#define GRE_LOCK_DESTROY(sc) rm_destroy(&(sc)->gre_lock)
#define GRE_RLOCK_TRACKER struct rm_priotracker gre_tracker
#define GRE_RLOCK(sc) rm_rlock(&(sc)->gre_lock, &gre_tracker)
#define GRE_RUNLOCK(sc) rm_runlock(&(sc)->gre_lock, &gre_tracker)
#define GRE_RLOCK_ASSERT(sc) rm_assert(&(sc)->gre_lock, RA_RLOCKED)
#define GRE_WLOCK(sc) rm_wlock(&(sc)->gre_lock)
#define GRE_WUNLOCK(sc) rm_wunlock(&(sc)->gre_lock)
#define GRE_WLOCK_ASSERT(sc) rm_assert(&(sc)->gre_lock, RA_WLOCKED)
#define gre_hdr gre_uhdr.hdr
#define gre_gihdr gre_uhdr.gihdr
#define gre_gi6hdr gre_uhdr.gi6hdr
#define gre_oip gre_gihdr->gi_ip
#define gre_oip6 gre_gi6hdr->gi6_ip6
int gre_input(struct mbuf *, int, int, void *);
#ifdef INET
int in_gre_attach(struct gre_softc *);
int in_gre_output(struct mbuf *, int, int);
#endif
#ifdef INET6
int in6_gre_attach(struct gre_softc *);
int in6_gre_output(struct mbuf *, int, int);
#endif
/*
* CISCO uses special type for GRE tunnel created as part of WCCP
* connection, while in fact those packets are just IPv4 encapsulated
* into GRE.
*/
#define ETHERTYPE_WCCP 0x883E
#endif /* _KERNEL */
#define GRESADDRS _IOW('i', 101, struct ifreq)
#define GRESADDRD _IOW('i', 102, struct ifreq)
#define GREGADDRS _IOWR('i', 103, struct ifreq)
#define GREGADDRD _IOWR('i', 104, struct ifreq)
#define GRESPROTO _IOW('i' , 105, struct ifreq)
#define GREGPROTO _IOWR('i', 106, struct ifreq)
#define GREGKEY _IOWR('i', 107, struct ifreq)
#define GRESKEY _IOW('i', 108, struct ifreq)
#define GREGOPTS _IOWR('i', 109, struct ifreq)
#define GRESOPTS _IOW('i', 110, struct ifreq)
#define GRE_ENABLE_CSUM 0x0001
#define GRE_ENABLE_SEQ 0x0002
#define GRE_OPTMASK (GRE_ENABLE_CSUM|GRE_ENABLE_SEQ)
#endif /* _NET_IF_GRE_H_ */