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/* $QuaggaId: Format:%an, %ai, %h$ $
*
* BGP Multipath
* Copyright (C) 2010 Google Inc.
*
* This file is part of Quagga
*
* Quagga 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.
*
* Quagga 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 Quagga; 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 "prefix.h"
#include "linklist.h"
#include "sockunion.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_table.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_mpath.h"
/*
* bgp_maximum_paths_set
*
* Record maximum-paths configuration for BGP instance
*/
int
bgp_maximum_paths_set (struct bgp *bgp, afi_t afi, safi_t safi,
int peertype, u_int16_t maxpaths)
{
if (!bgp || (afi >= AFI_MAX) || (safi >= SAFI_MAX))
return -1;
switch (peertype)
{
case BGP_PEER_IBGP:
bgp->maxpaths[afi][safi].maxpaths_ibgp = maxpaths;
break;
case BGP_PEER_EBGP:
bgp->maxpaths[afi][safi].maxpaths_ebgp = maxpaths;
break;
default:
return -1;
}
return 0;
}
/*
* bgp_maximum_paths_unset
*
* Remove maximum-paths configuration from BGP instance
*/
int
bgp_maximum_paths_unset (struct bgp *bgp, afi_t afi, safi_t safi,
int peertype)
{
if (!bgp || (afi >= AFI_MAX) || (safi >= SAFI_MAX))
return -1;
switch (peertype)
{
case BGP_PEER_IBGP:
bgp->maxpaths[afi][safi].maxpaths_ibgp = BGP_DEFAULT_MAXPATHS;
break;
case BGP_PEER_EBGP:
bgp->maxpaths[afi][safi].maxpaths_ebgp = BGP_DEFAULT_MAXPATHS;
break;
default:
return -1;
}
return 0;
}
/*
* bgp_info_nexthop_cmp
*
* Compare the nexthops of two paths. Return value is less than, equal to,
* or greater than zero if bi1 is respectively less than, equal to,
* or greater than bi2.
*/
static int
bgp_info_nexthop_cmp (struct bgp_info *bi1, struct bgp_info *bi2)
{
struct attr_extra *ae1, *ae2;
int compare;
ae1 = bgp_attr_extra_get (bi1->attr);
ae2 = bgp_attr_extra_get (bi2->attr);
compare = IPV4_ADDR_CMP (&bi1->attr->nexthop, &bi2->attr->nexthop);
if (!compare && ae1 && ae2 && (ae1->mp_nexthop_len == ae2->mp_nexthop_len))
{
switch (ae1->mp_nexthop_len)
{
case 4:
case 12:
compare = IPV4_ADDR_CMP (&ae1->mp_nexthop_global_in,
&ae2->mp_nexthop_global_in);
break;
#ifdef HAVE_IPV6
case 16:
compare = IPV6_ADDR_CMP (&ae1->mp_nexthop_global,
&ae2->mp_nexthop_global);
break;
case 32:
compare = IPV6_ADDR_CMP (&ae1->mp_nexthop_global,
&ae2->mp_nexthop_global);
if (!compare)
compare = IPV6_ADDR_CMP (&ae1->mp_nexthop_local,
&ae2->mp_nexthop_local);
break;
#endif /* HAVE_IPV6 */
}
}
return compare;
}
/*
* bgp_info_mpath_cmp
*
* This function determines our multipath list ordering. By ordering
* the list we can deterministically select which paths are included
* in the multipath set. The ordering also helps in detecting changes
* in the multipath selection so we can detect whether to send an
* update to zebra.
*
* The order of paths is determined first by received nexthop, and then
* by peer address if the nexthops are the same.
*/
static int
bgp_info_mpath_cmp (void *val1, void *val2)
{
struct bgp_info *bi1, *bi2;
int compare;
bi1 = val1;
bi2 = val2;
compare = bgp_info_nexthop_cmp (bi1, bi2);
if (!compare)
compare = sockunion_cmp (bi1->peer->su_remote, bi2->peer->su_remote);
return compare;
}
/*
* bgp_mp_list_init
*
* Initialize the mp_list, which holds the list of multipaths
* selected by bgp_best_selection
*/
void
bgp_mp_list_init (struct list *mp_list)
{
assert (mp_list);
memset (mp_list, 0, sizeof (struct list));
mp_list->cmp = bgp_info_mpath_cmp;
}
/*
* bgp_mp_list_clear
*
* Clears all entries out of the mp_list
*/
void
bgp_mp_list_clear (struct list *mp_list)
{
assert (mp_list);
list_delete_all_node (mp_list);
}
/*
* bgp_mp_list_add
*
* Adds a multipath entry to the mp_list
*/
void
bgp_mp_list_add (struct list *mp_list, struct bgp_info *mpinfo)
{
assert (mp_list && mpinfo);
listnode_add_sort (mp_list, mpinfo);
}
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