bgp_zebra.c

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

/* zebra client
   Copyright (C) 1997, 98, 99 Kunihiro Ishiguro

This file is part of GNU Zebra.

GNU Zebra is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

GNU Zebra is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Zebra; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <zebra.h>

#include "command.h"
#include "stream.h"
#include "network.h"
#include "prefix.h"
#include "log.h"
#include "sockunion.h"
#include "zclient.h"
#include "routemap.h"
#include "thread.h"

#include "bgpd/bgpd.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_nexthop.h"
#include "bgpd/bgp_zebra.h"
#include "bgpd/bgp_fsm.h"

/* All information about zebra. */
static struct zclient *zclient = NULL;

/* Update default router id. */
int
bgp_if_update (struct interface *ifp)
{
  struct bgp *bgp;
  listnode cn;
  struct listnode *nn;
  struct listnode *nm;
  struct peer *peer;

  for (cn = listhead (ifp->connected); cn; nextnode (cn))
    {
      struct connected *co;
      struct in_addr addr;

      co = getdata (cn);

      if (co->address->family == AF_INET)
	{
	  addr = co->address->u.prefix4;

	  /* Ignore NET127. */
	  if (IPV4_NET127 (ntohl (addr.s_addr)))
	    continue;

	  LIST_LOOP (bm->bgp, bgp, nn)
	    {
	      /* Respect configured router id */
	      if (! (bgp->config & BGP_CONFIG_ROUTER_ID))
		if (ntohl (bgp->router_id.s_addr) < ntohl (addr.s_addr))
		  {
		    bgp->router_id = addr;
		    LIST_LOOP (bgp->peer, peer, nm)
		      {
			peer->local_id = addr;
		      }
		  }
	    }
	}
    }
  return 0;
}

int
bgp_if_update_all ()
{
  listnode node;
  struct interface *ifp;

  for (node = listhead (iflist); node; node = nextnode (node))
    {
      ifp = getdata (node);
      bgp_if_update (ifp);
    }
  return 0;
}

/* Inteface addition message from zebra. */
int
bgp_interface_add (int command, struct zclient *zclient, zebra_size_t length)
{
  struct interface *ifp;

  ifp = zebra_interface_add_read (zclient->ibuf);
  bgp_if_update (ifp);

  return 0;
}

int
bgp_interface_delete (int command, struct zclient *zclient,
		      zebra_size_t length)
{
  struct stream *s;
  struct interface *ifp;

  s = zclient->ibuf;
  ifp = zebra_interface_state_read (s);

  return 0;
}

int
bgp_interface_up (int command, struct zclient *zclient, zebra_size_t length)
{
  struct stream *s;
  struct interface *ifp;
  struct connected *c;
  listnode node;

  s = zclient->ibuf;
  ifp = zebra_interface_state_read (s);

  if (! ifp)
    return 0;

  for (node = listhead (ifp->connected); node; nextnode (node))
    {
      c = getdata (node);
      bgp_connected_add (c);
    }

  return 0;
}

int
bgp_interface_down (int command, struct zclient *zclient, zebra_size_t length)
{
  struct stream *s;
  struct interface *ifp;
  struct connected *c;
  listnode node;

  s = zclient->ibuf;
  ifp = zebra_interface_state_read (s);
  if (! ifp)
    return 0;

  for (node = listhead (ifp->connected); node; nextnode (node))
    {
      c = getdata (node);
      bgp_connected_delete (c);
    }

  /* Fast external-failover (Currently IPv4 only) */
  {
    struct listnode *nn, *nm;
    struct bgp *bgp;
    struct peer *peer;
    struct interface *peer_if;

    LIST_LOOP (bm->bgp, bgp, nn)
      {
	if (CHECK_FLAG (bgp->flags, BGP_FLAG_NO_FAST_EXT_FAILOVER))
	  continue;

	LIST_LOOP (bgp->peer, peer, nm)
	  {
	    if (peer->ttl != 1)
	      continue;

	    if (peer->su.sa.sa_family == AF_INET)
	      peer_if = if_lookup_by_ipv4 (&peer->su.sin.sin_addr);
	    else
	      continue;

	    if (ifp == peer_if)
	      BGP_EVENT_ADD (peer, BGP_Stop);
	  }
      }
  }

  return 0;
}

int
bgp_interface_address_add (int command, struct zclient *zclient,
			   zebra_size_t length)
{
  struct connected *ifc;

  ifc = zebra_interface_address_add_read (zclient->ibuf);

  if (ifc == NULL)
    return 0;

  bgp_if_update (ifc->ifp);

  if (if_is_up (ifc->ifp))
    bgp_connected_add (ifc);

  return 0;
}

int
bgp_interface_address_delete (int command, struct zclient *zclient,
			      zebra_size_t length)
{
  struct connected *ifc;

  ifc = zebra_interface_address_delete_read (zclient->ibuf);

  if (ifc == NULL)
    return 0;

  bgp_if_update (ifc->ifp);

  if (if_is_up (ifc->ifp))
    bgp_connected_delete (ifc);

  connected_free (ifc);

  return 0;
}

/* Zebra route add and delete treatment. */
int
zebra_read_ipv4 (int command, struct zclient *zclient, zebra_size_t length)
{
  struct stream *s;
  struct zapi_ipv4 api;
  unsigned long ifindex;
  struct in_addr nexthop;
  struct prefix_ipv4 p;

  s = zclient->ibuf;
  ifindex = 0;
  nexthop.s_addr = 0;

  /* Type, flags, message. */
  api.type = stream_getc (s);
  api.flags = stream_getc (s);
  api.message = stream_getc (s);

  /* IPv4 prefix. */
  memset (&p, 0, sizeof (struct prefix_ipv4));
  p.family = AF_INET;
  p.prefixlen = stream_getc (s);
  stream_get (&p.prefix, s, PSIZE (p.prefixlen));

  /* Nexthop, ifindex, distance, metric. */
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_NEXTHOP))
    {
      api.nexthop_num = stream_getc (s);
      nexthop.s_addr = stream_get_ipv4 (s);
    }
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_IFINDEX))
    {
      api.ifindex_num = stream_getc (s);
      ifindex = stream_getl (s);
    }
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_DISTANCE))
    api.distance = stream_getc (s);
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_METRIC))
    api.metric = stream_getl (s);
  else
    api.metric = 0;

  if (command == ZEBRA_IPV4_ROUTE_ADD)
    bgp_redistribute_add ((struct prefix *)&p, &nexthop, api.metric, api.type);
  else
    bgp_redistribute_delete ((struct prefix *)&p, api.type);

  return 0;
}

#ifdef HAVE_IPV6
/* Zebra route add and delete treatment. */
int
zebra_read_ipv6 (int command, struct zclient *zclient, zebra_size_t length)
{
  struct stream *s;
  struct zapi_ipv6 api;
  unsigned long ifindex;
  struct in6_addr nexthop;
  struct prefix_ipv6 p;

  s = zclient->ibuf;
  ifindex = 0;
  memset (&nexthop, 0, sizeof (struct in6_addr));

  /* Type, flags, message. */
  api.type = stream_getc (s);
  api.flags = stream_getc (s);
  api.message = stream_getc (s);

  /* IPv6 prefix. */
  memset (&p, 0, sizeof (struct prefix_ipv6));
  p.family = AF_INET6;
  p.prefixlen = stream_getc (s);
  stream_get (&p.prefix, s, PSIZE (p.prefixlen));

  /* Nexthop, ifindex, distance, metric. */
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_NEXTHOP))
    {
      api.nexthop_num = stream_getc (s);
      stream_get (&nexthop, s, 16);
    }
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_IFINDEX))
    {
      api.ifindex_num = stream_getc (s);
      ifindex = stream_getl (s);
    }
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_DISTANCE))
    api.distance = stream_getc (s);
  else
    api.distance = 0;
  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_METRIC))
    api.metric = stream_getl (s);
  else
    api.metric = 0;

  /* Simply ignore link-local address. */
  if (IN6_IS_ADDR_LINKLOCAL (&p.prefix))
    return 0;

  if (command == ZEBRA_IPV6_ROUTE_ADD)
    bgp_redistribute_add ((struct prefix *)&p, NULL, api.metric, api.type);
  else
    bgp_redistribute_delete ((struct prefix *) &p, api.type);
  
  return 0;
}
#endif /* HAVE_IPV6 */

struct interface *
if_lookup_by_ipv4 (struct in_addr *addr)
{
  listnode ifnode;
  listnode cnode;
  struct interface *ifp;
  struct connected *connected;
  struct prefix_ipv4 p;
  struct prefix *cp; 
  
  p.family = AF_INET;
  p.prefix = *addr;
  p.prefixlen = IPV4_MAX_BITLEN;

  for (ifnode = listhead (iflist); ifnode; nextnode (ifnode))
    {
      ifp = getdata (ifnode);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  connected = getdata (cnode);
	  cp = connected->address;
	    
	  if (cp->family == AF_INET)
	    if (prefix_match (cp, (struct prefix *)&p))
	      return ifp;
	}
    }
  return NULL;
}

struct interface *
if_lookup_by_ipv4_exact (struct in_addr *addr)
{
  listnode ifnode;
  listnode cnode;
  struct interface *ifp;
  struct connected *connected;
  struct prefix *cp; 
  
  for (ifnode = listhead (iflist); ifnode; nextnode (ifnode))
    {
      ifp = getdata (ifnode);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  connected = getdata (cnode);
	  cp = connected->address;
	    
	  if (cp->family == AF_INET)
	    if (IPV4_ADDR_SAME (&cp->u.prefix4, addr))
	      return ifp;
	}
    }
  return NULL;
}

#ifdef HAVE_IPV6
struct interface *
if_lookup_by_ipv6 (struct in6_addr *addr)
{
  listnode ifnode;
  listnode cnode;
  struct interface *ifp;
  struct connected *connected;
  struct prefix_ipv6 p;
  struct prefix *cp; 
  
  p.family = AF_INET6;
  p.prefix = *addr;
  p.prefixlen = IPV6_MAX_BITLEN;

  for (ifnode = listhead (iflist); ifnode; nextnode (ifnode))
    {
      ifp = getdata (ifnode);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  connected = getdata (cnode);
	  cp = connected->address;
	    
	  if (cp->family == AF_INET6)
	    if (prefix_match (cp, (struct prefix *)&p))
	      return ifp;
	}
    }
  return NULL;
}

struct interface *
if_lookup_by_ipv6_exact (struct in6_addr *addr)
{
  listnode ifnode;
  listnode cnode;
  struct interface *ifp;
  struct connected *connected;
  struct prefix *cp; 

  for (ifnode = listhead (iflist); ifnode; nextnode (ifnode))
    {
      ifp = getdata (ifnode);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  connected = getdata (cnode);
	  cp = connected->address;
	    
	  if (cp->family == AF_INET6)
	    if (IPV6_ADDR_SAME (&cp->u.prefix6, addr))
	      return ifp;
	}
    }
  return NULL;
}

int
if_get_ipv6_global (struct interface *ifp, struct in6_addr *addr)
{
  listnode cnode;
  struct connected *connected;
  struct prefix *cp; 
  
  for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
    {
      connected = getdata (cnode);
      cp = connected->address;
	    
      if (cp->family == AF_INET6)
	if (! IN6_IS_ADDR_LINKLOCAL (&cp->u.prefix6))
	  {
	    memcpy (addr, &cp->u.prefix6, IPV6_MAX_BYTELEN);
	    return 1;
	  }
    }
  return 0;
}

int
if_get_ipv6_local (struct interface *ifp, struct in6_addr *addr)
{
  listnode cnode;
  struct connected *connected;
  struct prefix *cp; 
  
  for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
    {
      connected = getdata (cnode);
      cp = connected->address;
	    
      if (cp->family == AF_INET6)
	if (IN6_IS_ADDR_LINKLOCAL (&cp->u.prefix6))
	  {
	    memcpy (addr, &cp->u.prefix6, IPV6_MAX_BYTELEN);
	    return 1;