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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PIM for Quagga
* Copyright (C) 2008 Everton da Silva Marques
*/
#include <zebra.h>
#include "if.h"
#include "log.h"
#include "prefix.h"
#include "memory.h"
#include "jhash.h"
#include "pimd.h"
#include "pim_instance.h"
#include "pim_rpf.h"
#include "pim_pim.h"
#include "pim_str.h"
#include "pim_iface.h"
#include "pim_neighbor.h"
#include "pim_zlookup.h"
#include "pim_ifchannel.h"
#include "pim_time.h"
#include "pim_nht.h"
#include "pim_oil.h"
#include "pim_mlag.h"
static pim_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
void pim_rpf_set_refresh_time(struct pim_instance *pim)
{
pim->last_route_change_time = pim_time_monotonic_usec();
if (PIM_DEBUG_PIM_TRACE_DETAIL)
zlog_debug("%s: vrf(%s) New last route change time: %" PRId64,
__func__, pim->vrf->name,
pim->last_route_change_time);
}
static int nexthop_mismatch(const struct pim_nexthop *nh1,
const struct pim_nexthop *nh2)
{
return (nh1->interface != nh2->interface) ||
(pim_addr_cmp(nh1->mrib_nexthop_addr, nh2->mrib_nexthop_addr)) ||
(nh1->mrib_metric_preference != nh2->mrib_metric_preference) ||
(nh1->mrib_route_metric != nh2->mrib_route_metric);
}
static void pim_rpf_cost_change(struct pim_instance *pim,
struct pim_upstream *up, uint32_t old_cost)
{
struct pim_rpf *rpf = &up->rpf;
uint32_t new_cost;
new_cost = pim_up_mlag_local_cost(up);
if (PIM_DEBUG_MLAG)
zlog_debug(
"%s: Cost_to_rp of upstream-%s changed to:%u, from:%u",
__func__, up->sg_str, new_cost, old_cost);
if (old_cost == new_cost)
return;
/* Cost changed, it might Impact MLAG DF election, update */
if (PIM_DEBUG_MLAG)
zlog_debug(
"%s: Cost_to_rp of upstream-%s changed to:%u",
__func__, up->sg_str,
rpf->source_nexthop.mrib_route_metric);
if (pim_up_mlag_is_local(up))
pim_mlag_up_local_add(pim, up);
}
enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
struct pim_upstream *up, struct pim_rpf *old,
const char *caller)
{
struct pim_rpf *rpf = &up->rpf;
struct pim_rpf saved;
pim_addr src;
struct prefix grp;
bool neigh_needed = true;
uint32_t saved_mrib_route_metric;
if (PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(up->flags))
return PIM_RPF_OK;
if (pim_addr_is_any(up->upstream_addr)) {
zlog_debug("%s(%s): RP is not configured yet for %s",
__func__, caller, up->sg_str);
return PIM_RPF_OK;
}
saved.source_nexthop = rpf->source_nexthop;
saved.rpf_addr = rpf->rpf_addr;
saved_mrib_route_metric = pim_up_mlag_local_cost(up);
if (old) {
old->source_nexthop = saved.source_nexthop;
old->rpf_addr = saved.rpf_addr;
}
src = up->upstream_addr; // RP or Src address
pim_addr_to_prefix(&grp, up->sg.grp);
if ((pim_addr_is_any(up->sg.src) && I_am_RP(pim, up->sg.grp)) ||
PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
neigh_needed = false;
pim_nht_find_or_track(pim, up->upstream_addr, up, NULL, NULL);
if (!pim_nht_lookup_ecmp(pim, &rpf->source_nexthop, src, &grp, neigh_needed)) {
/* Route is Deleted in Zebra, reset the stored NH data */
pim_upstream_rpf_clear(pim, up);
pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
return PIM_RPF_FAILURE;
}
rpf->rpf_addr = pim_rpf_find_rpf_addr(up);
if (pim_rpf_addr_is_inaddr_any(rpf) && PIM_DEBUG_ZEBRA) {
/* RPF'(S,G) not found */
zlog_debug("%s(%s): RPF'%s not found: won't send join upstream",
__func__, caller, up->sg_str);
/* warning only */
}
/* detect change in pim_nexthop */
if (nexthop_mismatch(&rpf->source_nexthop, &saved.source_nexthop)) {
if (PIM_DEBUG_ZEBRA)
zlog_debug("%s(%s): (S,G)=%s source nexthop now is: interface=%s address=%pPAs pref=%d metric=%d",
__func__, caller,
up->sg_str,
rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
&rpf->source_nexthop.mrib_nexthop_addr,
rpf->source_nexthop.mrib_metric_preference,
rpf->source_nexthop.mrib_route_metric);
pim_upstream_update_join_desired(pim, up);
pim_upstream_update_could_assert(up);
pim_upstream_update_my_assert_metric(up);
}
/* detect change in RPF_interface(S) */
if (saved.source_nexthop.interface != rpf->source_nexthop.interface) {
if (PIM_DEBUG_ZEBRA) {
zlog_debug("%s(%s): (S,G)=%s RPF_interface(S) changed from %s to %s",
__func__, caller,
up->sg_str,
saved.source_nexthop.interface ? saved.source_nexthop.interface->name : "<oldif?>",
rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
/* warning only */
}
pim_upstream_rpf_interface_changed(
up, saved.source_nexthop.interface);
}
/* detect change in RPF'(S,G) */
if (pim_addr_cmp(saved.rpf_addr, rpf->rpf_addr) ||
saved.source_nexthop.interface != rpf->source_nexthop.interface) {
pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
return PIM_RPF_CHANGED;
}
if (PIM_DEBUG_MLAG)
zlog_debug(
"%s(%s): Cost_to_rp of upstream-%s changed to:%u",
__func__, caller, up->sg_str,
rpf->source_nexthop.mrib_route_metric);
pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
return PIM_RPF_OK;
}
/*
* In the case of RP deletion and RP unreachablity,
* uninstall the mroute in the kernel and clear the
* rpf information in the pim upstream and pim channel
* oil data structure.
*/
void pim_upstream_rpf_clear(struct pim_instance *pim,
struct pim_upstream *up)
{
if (up->rpf.source_nexthop.interface) {
pim_upstream_switch(pim, up, PIM_UPSTREAM_NOTJOINED);
up->rpf.source_nexthop.interface = NULL;
up->rpf.source_nexthop.mrib_nexthop_addr = PIMADDR_ANY;
up->rpf.source_nexthop.mrib_metric_preference =
router->infinite_assert_metric.metric_preference;
up->rpf.source_nexthop.mrib_route_metric =
router->infinite_assert_metric.route_metric;
up->rpf.rpf_addr = PIMADDR_ANY;
pim_upstream_mroute_iif_update(up->channel_oil, __func__);
}
}
/*
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 pim_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
{
struct pim_ifchannel *rpf_ch;
struct pim_neighbor *neigh;
pim_addr rpf_addr;
if (!up->rpf.source_nexthop.interface) {
zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
__func__, up->sg_str);
return PIMADDR_ANY;
}
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 = PIMADDR_ANY;
return rpf_addr;
}
int pim_rpf_addr_is_inaddr_any(struct pim_rpf *rpf)
{
return pim_addr_is_any(rpf->rpf_addr);
}
int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2)
{
if (rpf1->source_nexthop.interface == rpf2->source_nexthop.interface)
return 1;
return 0;
}
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