freebsd-skq/sys/netinet/if_ether.h
melifaro 93152c67c9 Implement interface link header precomputation API.
Add if_requestencap() interface method which is capable of calculating
  various link headers for given interface. Right now there is support
  for INET/INET6/ARP llheader calculation (IFENCAP_LL type request).
  Other types are planned to support more complex calculation
  (L2 multipath lagg nexthops, tunnel encap nexthops, etc..).

Reshape 'struct route' to be able to pass additional data (with is length)
  to prepend to mbuf.

These two changes permits routing code to pass pre-calculated nexthop data
  (like L2 header for route w/gateway) down to the stack eliminating the
  need for other lookups. It also brings us closer to more complex scenarios
  like transparently handling MPLS nexthops and tunnel interfaces.
  Last, but not least, it removes layering violation introduced by flowtable
  code (ro_lle) and simplifies handling of existing if_output consumers.

ARP/ND changes:
Make arp/ndp stack pre-calculate link header upon installing/updating lle
  record. Interface link address change are handled by re-calculating
  headers for all lles based on if_lladdr event. After these changes,
  arpresolve()/nd6_resolve() returns full pre-calculated header for
  supported interfaces thus simplifying if_output().
Move these lookups to separate ether_resolve_addr() function which ether
  returs error or fully-prepared link header. Add <arp|nd6_>resolve_addr()
  compat versions to return link addresses instead of pre-calculated data.

BPF changes:
Raw bpf writes occupied _two_ cases: AF_UNSPEC and pseudo_AF_HDRCMPLT.
Despite the naming, both of there have ther header "complete". The only
  difference is that interface source mac has to be filled by OS for
  AF_UNSPEC (controlled via BIOCGHDRCMPLT). This logic has to stay inside
  BPF and not pollute if_output() routines. Convert BPF to pass prepend data
  via new 'struct route' mechanism. Note that it does not change
  non-optimized if_output(): ro_prepend handling is purely optional.
Side note: hackish pseudo_AF_HDRCMPLT is supported for ethernet and FDDI.
  It is not needed for ethernet anymore. The only remaining FDDI user is
  dev/pdq mostly untouched since 2007. FDDI support was eliminated from
  OpenBSD in 2013 (sys/net/if_fddisubr.c rev 1.65).

Flowtable changes:
  Flowtable violates layering by saving (and not correctly managing)
  rtes/lles. Instead of passing lle pointer, pass pointer to pre-calculated
  header data from that lle.

Differential Revision:	https://reviews.freebsd.org/D4102
2015-12-31 05:03:27 +00:00

128 lines
4.6 KiB
C

/*-
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)if_ether.h 8.3 (Berkeley) 5/2/95
* $FreeBSD$
*/
#ifndef _NETINET_IF_ETHER_H_
#define _NETINET_IF_ETHER_H_
#include <net/ethernet.h>
#include <net/if_arp.h>
/*
* Macro to map an IP multicast address to an Ethernet multicast address.
* The high-order 25 bits of the Ethernet address are statically assigned,
* and the low-order 23 bits are taken from the low end of the IP address.
*/
#define ETHER_MAP_IP_MULTICAST(ipaddr, enaddr) \
/* struct in_addr *ipaddr; */ \
/* u_char enaddr[ETHER_ADDR_LEN]; */ \
{ \
(enaddr)[0] = 0x01; \
(enaddr)[1] = 0x00; \
(enaddr)[2] = 0x5e; \
(enaddr)[3] = ((const u_char *)ipaddr)[1] & 0x7f; \
(enaddr)[4] = ((const u_char *)ipaddr)[2]; \
(enaddr)[5] = ((const u_char *)ipaddr)[3]; \
}
/*
* Macro to map an IP6 multicast address to an Ethernet multicast address.
* The high-order 16 bits of the Ethernet address are statically assigned,
* and the low-order 32 bits are taken from the low end of the IP6 address.
*/
#define ETHER_MAP_IPV6_MULTICAST(ip6addr, enaddr) \
/* struct in6_addr *ip6addr; */ \
/* u_char enaddr[ETHER_ADDR_LEN]; */ \
{ \
(enaddr)[0] = 0x33; \
(enaddr)[1] = 0x33; \
(enaddr)[2] = ((const u_char *)ip6addr)[12]; \
(enaddr)[3] = ((const u_char *)ip6addr)[13]; \
(enaddr)[4] = ((const u_char *)ip6addr)[14]; \
(enaddr)[5] = ((const u_char *)ip6addr)[15]; \
}
/*
* Ethernet Address Resolution Protocol.
*
* See RFC 826 for protocol description. Structure below is adapted
* to resolving internet addresses. Field names used correspond to
* RFC 826.
*/
struct ether_arp {
struct arphdr ea_hdr; /* fixed-size header */
u_char arp_sha[ETHER_ADDR_LEN]; /* sender hardware address */
u_char arp_spa[4]; /* sender protocol address */
u_char arp_tha[ETHER_ADDR_LEN]; /* target hardware address */
u_char arp_tpa[4]; /* target protocol address */
};
#define arp_hrd ea_hdr.ar_hrd
#define arp_pro ea_hdr.ar_pro
#define arp_hln ea_hdr.ar_hln
#define arp_pln ea_hdr.ar_pln
#define arp_op ea_hdr.ar_op
#ifndef BURN_BRIDGES /* Can be used by third party software. */
struct sockaddr_inarp {
u_char sin_len;
u_char sin_family;
u_short sin_port;
struct in_addr sin_addr;
struct in_addr sin_srcaddr;
u_short sin_tos;
u_short sin_other;
#define SIN_PROXY 1
};
#endif /* !BURN_BRIDGES */
/*
* IP and ethernet specific routing flags
*/
#define RTF_USETRAILERS RTF_PROTO1 /* use trailers */
#define RTF_ANNOUNCE RTF_PROTO2 /* announce new arp entry */
#ifdef _KERNEL
extern u_char ether_ipmulticast_min[ETHER_ADDR_LEN];
extern u_char ether_ipmulticast_max[ETHER_ADDR_LEN];
struct ifaddr;
int arpresolve_addr(struct ifnet *ifp, int flags,
const struct sockaddr *dst, char *desten, uint32_t *pflags);
int arpresolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
const struct sockaddr *dst, u_char *desten, uint32_t *pflags);
void arprequest(struct ifnet *, const struct in_addr *,
const struct in_addr *, u_char *);
void arp_ifinit(struct ifnet *, struct ifaddr *);
void arp_announce_ifaddr(struct ifnet *, struct in_addr addr, u_char *);
#endif
#endif