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/*
PIM for Quagga
Copyright (C) 2008 Everton da Silva Marques
This program 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 of the License, or
(at your option) any later version.
This program 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 this program; see the file COPYING; if not, write to the
Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301 USA
*/
#include <zebra.h>
#include "if.h"
#include "log.h"
#include "prefix.h"
#include "memory.h"
#include "pimd.h"
#include "pim_rpf.h"
#include "pim_pim.h"
#include "pim_str.h"
#include "pim_iface.h"
#include "pim_zlookup.h"
#include "pim_ifchannel.h"
static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
int pim_nexthop_lookup(struct pim_nexthop *nexthop, struct in_addr addr)
{
struct pim_zlookup_nexthop nexthop_tab[PIM_NEXTHOP_IFINDEX_TAB_SIZE];
int num_ifindex;
struct interface *ifp;
int first_ifindex;
memset (nexthop_tab, 0, sizeof (struct pim_zlookup_nexthop) * PIM_NEXTHOP_IFINDEX_TAB_SIZE);
num_ifindex = zclient_lookup_nexthop(nexthop_tab,
PIM_NEXTHOP_IFINDEX_TAB_SIZE,
addr, PIM_NEXTHOP_LOOKUP_MAX);
if (num_ifindex < 1) {
char addr_str[100];
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_warn("%s %s: could not find nexthop ifindex for address %s",
__FILE__, __PRETTY_FUNCTION__,
addr_str);
return -1;
}
first_ifindex = nexthop_tab[0].ifindex;
if (num_ifindex > 1) {
char addr_str[100];
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_info("%s %s: FIXME ignoring multiple nexthop ifindex'es num_ifindex=%d for address %s (using only ifindex=%d)",
__FILE__, __PRETTY_FUNCTION__,
num_ifindex, addr_str, first_ifindex);
/* debug warning only, do not return */
}
ifp = if_lookup_by_index(first_ifindex);
if (!ifp) {
char addr_str[100];
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_warn("%s %s: could not find interface for ifindex %d (address %s)",
__FILE__, __PRETTY_FUNCTION__,
first_ifindex, addr_str);
return -2;
}
if (!ifp->info) {
char addr_str[100];
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_warn("%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
__PRETTY_FUNCTION__,
ifp->name, first_ifindex, addr_str);
/* debug warning only, do not return */
}
if (PIM_DEBUG_PIM_TRACE) {
char nexthop_str[100];
char addr_str[100];
pim_inet4_dump("<nexthop?>", nexthop_tab[0].nexthop_addr, nexthop_str, sizeof(nexthop_str));
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_debug("%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
__FILE__, __PRETTY_FUNCTION__,
nexthop_str, addr_str,
ifp->name, first_ifindex,
nexthop_tab[0].route_metric,
nexthop_tab[0].protocol_distance);
}
/* update nextop data */
nexthop->interface = ifp;
nexthop->mrib_nexthop_addr = nexthop_tab[0].nexthop_addr;
nexthop->mrib_metric_preference = nexthop_tab[0].protocol_distance;
nexthop->mrib_route_metric = nexthop_tab[0].route_metric;
return 0;
}
static int nexthop_mismatch(const struct pim_nexthop *nh1,
const struct pim_nexthop *nh2)
{
return (nh1->interface != nh2->interface)
||
(nh1->mrib_nexthop_addr.s_addr != nh2->mrib_nexthop_addr.s_addr)
||
(nh1->mrib_metric_preference != nh2->mrib_metric_preference)
||
(nh1->mrib_route_metric != nh2->mrib_route_metric);
}
enum pim_rpf_result pim_rpf_update(struct pim_upstream *up, struct in_addr *old_rpf_addr)
{
struct in_addr save_rpf_addr;
struct pim_nexthop save_nexthop;
struct pim_rpf *rpf = &up->rpf;
save_nexthop = rpf->source_nexthop; /* detect change in pim_nexthop */
save_rpf_addr = rpf->rpf_addr; /* detect change in RPF'(S,G) */
if (pim_nexthop_lookup(&rpf->source_nexthop, up->upstream_addr)) {
return PIM_RPF_FAILURE;
}
rpf->rpf_addr = pim_rpf_find_rpf_addr(up);
if (PIM_INADDR_IS_ANY(rpf->rpf_addr) && PIM_DEBUG_PIM_EVENTS) {
/* RPF'(S,G) not found */
zlog_debug("%s %s: RPF'%s not found: won't send join upstream",
__FILE__, __PRETTY_FUNCTION__,
pim_str_sg_dump (&up->sg));
/* warning only */
}
/* detect change in pim_nexthop */
if (nexthop_mismatch(&rpf->source_nexthop, &save_nexthop)) {
if (PIM_DEBUG_PIM_EVENTS) {
char nhaddr_str[100];
pim_inet4_dump("<addr?>", rpf->source_nexthop.mrib_nexthop_addr, nhaddr_str, sizeof(nhaddr_str));
zlog_debug("%s %s: (S,G)=%s source nexthop now is: interface=%s address=%s pref=%d metric=%d",
__FILE__, __PRETTY_FUNCTION__,
pim_str_sg_dump (&up->sg),
rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
nhaddr_str,
rpf->source_nexthop.mrib_metric_preference,
rpf->source_nexthop.mrib_route_metric);
}
pim_upstream_update_join_desired(up);
pim_upstream_update_could_assert(up);
pim_upstream_update_my_assert_metric(up);
}
/* detect change in RPF_interface(S) */
if (save_nexthop.interface != rpf->source_nexthop.interface) {
if (PIM_DEBUG_PIM_EVENTS) {
zlog_debug("%s %s: (S,G)=%s RPF_interface(S) changed from %s to %s",
__FILE__, __PRETTY_FUNCTION__,
pim_str_sg_dump (&up->sg),
save_nexthop.interface ? save_nexthop.interface->name : "<oldif?>",
rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
/* warning only */
}
pim_upstream_rpf_interface_changed(up, save_nexthop.interface);
}
/* detect change in RPF'(S,G) */
if (save_rpf_addr.s_addr != rpf->rpf_addr.s_addr) {
/* return old rpf to caller ? */
if (old_rpf_addr)
*old_rpf_addr = save_rpf_addr;
return PIM_RPF_CHANGED;
}
return PIM_RPF_OK;
}
/*
RFC 4601: 4.1.6. State Summarization Macros
neighbor RPF'(S,G) {
if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
return AssertWinner(S, G, RPF_interface(S) )
} else {
return NBR( RPF_interface(S), MRIB.next_hop( S ) )
}
}
RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
packets should be coming and to which joins should be sent on the RP
tree and SPT, respectively.
*/
static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
{
struct pim_ifchannel *rpf_ch;
struct pim_neighbor *neigh;
struct in_addr rpf_addr;
if (!up->rpf.source_nexthop.interface) {
zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
__PRETTY_FUNCTION__,
pim_str_sg_dump (&up->sg));
rpf_addr.s_addr = PIM_NET_INADDR_ANY;
return rpf_addr;
}
rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface,
&up->sg);
if (rpf_ch) {
if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
return rpf_ch->ifassert_winner;
}
}
/* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
neigh = pim_if_find_neighbor(up->rpf.source_nexthop.interface,
up->rpf.source_nexthop.mrib_nexthop_addr);
if (neigh)
rpf_addr = neigh->source_addr;
else
rpf_addr.s_addr = PIM_NET_INADDR_ANY;
return rpf_addr;
}
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