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pim_nht.c
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/*
* PIM for Quagga
* Copyright (C) 2017 Cumulus Networks, Inc.
* Chirag Shah
*
* 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 "network.h"
#include "zclient.h"
#include "stream.h"
#include "nexthop.h"
#include "if.h"
#include "hash.h"
#include "jhash.h"
#include "pimd.h"
#include "pimd/pim_nht.h"
#include "log.h"
#include "pim_time.h"
#include "pim_oil.h"
#include "pim_ifchannel.h"
#include "pim_mroute.h"
#include "pim_zebra.h"
#include "pim_upstream.h"
#include "pim_join.h"
#include "pim_jp_agg.h"
#include "pim_zebra.h"
#include "pim_zlookup.h"
#include "pim_rp.h"
/**
* pim_sendmsg_zebra_rnh -- Format and send a nexthop register/Unregister
* command to Zebra.
*/
void pim_sendmsg_zebra_rnh(struct pim_instance *pim, struct zclient *zclient,
struct pim_nexthop_cache *pnc, int command)
{
struct prefix *p;
int ret;
p = &(pnc->rpf.rpf_addr);
ret = zclient_send_rnh(zclient, command, p, false, pim->vrf_id);
if (ret < 0)
zlog_warn("sendmsg_nexthop: zclient_send_message() failed");
if (PIM_DEBUG_PIM_NHT) {
char buf[PREFIX2STR_BUFFER];
prefix2str(p, buf, sizeof(buf));
zlog_debug(
"%s: NHT %sregistered addr %s(%s) with Zebra ret:%d ",
__func__,
(command == ZEBRA_NEXTHOP_REGISTER) ? " " : "de", buf,
pim->vrf->name, ret);
}
return;
}
struct pim_nexthop_cache *pim_nexthop_cache_find(struct pim_instance *pim,
struct pim_rpf *rpf)
{
struct pim_nexthop_cache *pnc = NULL;
struct pim_nexthop_cache lookup;
lookup.rpf.rpf_addr.family = rpf->rpf_addr.family;
lookup.rpf.rpf_addr.prefixlen = rpf->rpf_addr.prefixlen;
lookup.rpf.rpf_addr.u.prefix4.s_addr = rpf->rpf_addr.u.prefix4.s_addr;
pnc = hash_lookup(pim->rpf_hash, &lookup);
return pnc;
}
static struct pim_nexthop_cache *pim_nexthop_cache_add(struct pim_instance *pim,
struct pim_rpf *rpf_addr)
{
struct pim_nexthop_cache *pnc;
char hash_name[64];
char buf1[64];
pnc = XCALLOC(MTYPE_PIM_NEXTHOP_CACHE,
sizeof(struct pim_nexthop_cache));
pnc->rpf.rpf_addr.family = rpf_addr->rpf_addr.family;
pnc->rpf.rpf_addr.prefixlen = rpf_addr->rpf_addr.prefixlen;
pnc->rpf.rpf_addr.u.prefix4.s_addr =
rpf_addr->rpf_addr.u.prefix4.s_addr;
pnc = hash_get(pim->rpf_hash, pnc, hash_alloc_intern);
pnc->rp_list = list_new();
pnc->rp_list->cmp = pim_rp_list_cmp;
snprintf(hash_name, 64, "PNC %s(%s) Upstream Hash",
prefix2str(&pnc->rpf.rpf_addr, buf1, 64), pim->vrf->name);
pnc->upstream_hash = hash_create_size(8192, pim_upstream_hash_key,
pim_upstream_equal, hash_name);
return pnc;
}
/*
* pim_find_or_track_nexthop
*
* This API is used to Register an address with Zebra
*
* 1 -> Success
* 0 -> Failure
*/
int pim_find_or_track_nexthop(struct pim_instance *pim, struct prefix *addr,
struct pim_upstream *up, struct rp_info *rp,
bool bsr_track_needed,
struct pim_nexthop_cache *out_pnc)
{
struct pim_nexthop_cache *pnc = NULL;
struct pim_rpf rpf;
struct listnode *ch_node = NULL;
struct zclient *zclient = NULL;
zclient = pim_zebra_zclient_get();
memset(&rpf, 0, sizeof(struct pim_rpf));
rpf.rpf_addr.family = addr->family;
rpf.rpf_addr.prefixlen = addr->prefixlen;
rpf.rpf_addr.u.prefix4 = addr->u.prefix4;
pnc = pim_nexthop_cache_find(pim, &rpf);
if (!pnc) {
pnc = pim_nexthop_cache_add(pim, &rpf);
pim_sendmsg_zebra_rnh(pim, zclient, pnc,
ZEBRA_NEXTHOP_REGISTER);
if (PIM_DEBUG_PIM_NHT) {
char buf[PREFIX2STR_BUFFER];
prefix2str(addr, buf, sizeof(buf));
zlog_debug(
"%s: NHT cache and zebra notification added for %s(%s)",
__func__, buf, pim->vrf->name);
}
}
if (rp != NULL) {
ch_node = listnode_lookup(pnc->rp_list, rp);
if (ch_node == NULL)
listnode_add_sort(pnc->rp_list, rp);
}
if (up != NULL)
hash_get(pnc->upstream_hash, up, hash_alloc_intern);
if (bsr_track_needed)
pnc->bsr_tracking = true;
if (CHECK_FLAG(pnc->flags, PIM_NEXTHOP_VALID)) {
if (out_pnc)
memcpy(out_pnc, pnc, sizeof(struct pim_nexthop_cache));
return 1;
}
return 0;
}
void pim_delete_tracked_nexthop(struct pim_instance *pim, struct prefix *addr,
struct pim_upstream *up, struct rp_info *rp,
bool del_bsr_tracking)
{
struct pim_nexthop_cache *pnc = NULL;
struct pim_nexthop_cache lookup;
struct zclient *zclient = NULL;
struct pim_upstream *upstream = NULL;
zclient = pim_zebra_zclient_get();
/* Remove from RPF hash if it is the last entry */
lookup.rpf.rpf_addr = *addr;
pnc = hash_lookup(pim->rpf_hash, &lookup);
if (pnc) {
if (rp) {
/* Release the (*, G)upstream from pnc->upstream_hash,
* whose Group belongs to the RP getting deleted
*/
frr_each (rb_pim_upstream, &pim->upstream_head,
upstream) {
struct prefix grp;
struct rp_info *trp_info;
if (upstream->sg.src.s_addr != INADDR_ANY)
continue;
grp.family = AF_INET;
grp.prefixlen = IPV4_MAX_BITLEN;
grp.u.prefix4 = upstream->sg.grp;
trp_info = pim_rp_find_match_group(pim, &grp);
if (trp_info == rp)
hash_release(pnc->upstream_hash,
upstream);
}
listnode_delete(pnc->rp_list, rp);
}
if (up)
hash_release(pnc->upstream_hash, up);
if (del_bsr_tracking)
pnc->bsr_tracking = false;
if (PIM_DEBUG_PIM_NHT) {
char buf[PREFIX_STRLEN];
prefix2str(addr, buf, sizeof(buf));
zlog_debug(
"%s: NHT %s(%s) rp_list count:%d upstream count:%ld",
__func__, buf, pim->vrf->name,
pnc->rp_list->count, pnc->upstream_hash->count);
}
if (pnc->rp_list->count == 0
&& pnc->upstream_hash->count == 0
&& pnc->bsr_tracking == false) {
pim_sendmsg_zebra_rnh(pim, zclient, pnc,
ZEBRA_NEXTHOP_UNREGISTER);
list_delete(&pnc->rp_list);
hash_free(pnc->upstream_hash);
hash_release(pim->rpf_hash, pnc);
if (pnc->nexthop)
nexthops_free(pnc->nexthop);
XFREE(MTYPE_PIM_NEXTHOP_CACHE, pnc);
}
}
}
/* Given a source address and a neighbor address, check if the neighbor is one
* of the next hop to reach the source. search from zebra route database
*/
bool pim_nexthop_match(struct pim_instance *pim, struct in_addr addr,
struct in_addr ip_src)
{
struct pim_zlookup_nexthop nexthop_tab[MULTIPATH_NUM];
int i = 0;
ifindex_t first_ifindex = 0;
struct interface *ifp = NULL;
struct pim_neighbor *nbr = NULL;
int num_ifindex;
if (addr.s_addr == INADDR_NONE)
return false;
memset(nexthop_tab, 0,
sizeof(struct pim_zlookup_nexthop) * MULTIPATH_NUM);
num_ifindex = zclient_lookup_nexthop(pim, nexthop_tab, MULTIPATH_NUM,
addr, PIM_NEXTHOP_LOOKUP_MAX);
if (num_ifindex < 1) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
zlog_warn(
"%s %s: could not find nexthop ifindex for address %s",
__FILE__, __func__, addr_str);
return false;
}
while (i < num_ifindex) {
first_ifindex = nexthop_tab[i].ifindex;
ifp = if_lookup_by_index(first_ifindex, pim->vrf_id);
if (!ifp) {
if (PIM_DEBUG_ZEBRA) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", addr, addr_str,
sizeof(addr_str));
zlog_debug(
"%s %s: could not find interface for ifindex %d (address %s)",
__FILE__, __func__, first_ifindex,
addr_str);
}
i++;
continue;
}
if (!ifp->info) {
if (PIM_DEBUG_ZEBRA) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", addr, addr_str,
sizeof(addr_str));
zlog_debug(
"%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
__func__, ifp->name, first_ifindex,
addr_str);
}
i++;
continue;
}
if (!pim_if_connected_to_source(ifp, addr)) {
nbr = pim_neighbor_find(
ifp, nexthop_tab[i].nexthop_addr.u.prefix4);
if (PIM_DEBUG_PIM_TRACE_DETAIL)
zlog_debug("ifp name: %s, pim nbr: %p",
ifp->name, nbr);
if (!nbr && !if_is_loopback(ifp)) {
i++;
continue;
}
}
if (nexthop_tab[i].nexthop_addr.u.prefix4.s_addr
== ip_src.s_addr)
return true;
i++;
}
return false;
}
/* Given a source address and a neighbor address, check if the neighbor is one
* of the next hop to reach the source. search from pim next hop cache
*/
bool pim_nexthop_match_nht_cache(struct pim_instance *pim, struct in_addr addr,
struct in_addr ip_src)
{
struct pim_rpf rpf;
ifindex_t first_ifindex;
struct interface *ifp = NULL;
uint8_t nh_iter = 0;
struct pim_neighbor *nbr = NULL;
struct nexthop *nh_node = NULL;
struct pim_nexthop_cache *pnc = NULL;
memset(&rpf, 0, sizeof(struct pim_rpf));
rpf.rpf_addr.family = AF_INET;
rpf.rpf_addr.prefixlen = IPV4_MAX_BITLEN;
rpf.rpf_addr.u.prefix4 = addr;
pnc = pim_nexthop_cache_find(pim, &rpf);
if (!pnc || !pnc->nexthop_num)
return false;
for (nh_node = pnc->nexthop; nh_node; nh_node = nh_node->next) {
first_ifindex = nh_node->ifindex;
ifp = if_lookup_by_index(first_ifindex, pim->vrf_id);
if (!ifp) {
if (PIM_DEBUG_PIM_NHT) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", addr, addr_str,
sizeof(addr_str));
zlog_debug(
"%s %s: could not find interface for ifindex %d (address %s(%s))",
__FILE__, __func__, first_ifindex,
addr_str, pim->vrf->name);
}
nh_iter++;
continue;
}
if (!ifp->info) {
if (PIM_DEBUG_PIM_NHT) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", addr, addr_str,
sizeof(addr_str));
zlog_debug(
"%s: multicast not enabled on input interface %s(%s) (ifindex=%d, RPF for source %s)",
__func__, ifp->name, pim->vrf->name,
first_ifindex, addr_str);
}
nh_iter++;
continue;
}
if (!pim_if_connected_to_source(ifp, addr)) {
nbr = pim_neighbor_find(ifp, nh_node->gate.ipv4);
if (!nbr && !if_is_loopback(ifp)) {
if (PIM_DEBUG_PIM_NHT)
zlog_debug(
"%s: pim nbr not found on input interface %s(%s)",
__func__, ifp->name,
pim->vrf->name);
nh_iter++;
continue;
}
}
if (nh_node->gate.ipv4.s_addr == ip_src.s_addr)
return true;
}
return false;
}
void pim_rp_nexthop_del(struct rp_info *rp_info)
{
rp_info->rp.source_nexthop.interface = NULL;
rp_info->rp.source_nexthop.mrib_nexthop_addr.u.prefix4.s_addr =
PIM_NET_INADDR_ANY;
rp_info->rp.source_nexthop.mrib_metric_preference =
router->infinite_assert_metric.metric_preference;
rp_info->rp.source_nexthop.mrib_route_metric =
router->infinite_assert_metric.route_metric;
}
/* Update RP nexthop info based on Nexthop update received from Zebra.*/
static void pim_update_rp_nh(struct pim_instance *pim,
struct pim_nexthop_cache *pnc)
{
struct listnode *node = NULL;
struct rp_info *rp_info = NULL;
/*Traverse RP list and update each RP Nexthop info */
for (ALL_LIST_ELEMENTS_RO(pnc->rp_list, node, rp_info)) {
if (rp_info->rp.rpf_addr.u.prefix4.s_addr == INADDR_NONE)
continue;
// Compute PIM RPF using cached nexthop
if (!pim_ecmp_nexthop_lookup(pim, &rp_info->rp.source_nexthop,
&rp_info->rp.rpf_addr,
&rp_info->group, 1))
pim_rp_nexthop_del(rp_info);
}
}
/* Update Upstream nexthop info based on Nexthop update received from Zebra.*/
static int pim_update_upstream_nh_helper(struct hash_bucket *bucket, void *arg)
{
struct pim_instance *pim = (struct pim_instance *)arg;
struct pim_upstream *up = (struct pim_upstream *)bucket->data;
enum pim_rpf_result rpf_result;
struct pim_rpf old;
old.source_nexthop.interface = up->rpf.source_nexthop.interface;
rpf_result = pim_rpf_update(pim, up, &old, __func__);
/* update kernel multicast forwarding cache (MFC); if the
* RPF nbr is now unreachable the MFC has already been updated
* by pim_rpf_clear
*/
if (rpf_result != PIM_RPF_FAILURE)
pim_upstream_mroute_iif_update(up->channel_oil, __func__);
if (rpf_result == PIM_RPF_CHANGED ||
(rpf_result == PIM_RPF_FAILURE && old.source_nexthop.interface))
pim_zebra_upstream_rpf_changed(pim, up, &old);
if (PIM_DEBUG_PIM_NHT) {
zlog_debug(
"%s: NHT upstream %s(%s) old ifp %s new ifp %s",
__func__, up->sg_str, pim->vrf->name,
old.source_nexthop.interface ? old.source_nexthop
.interface->name
: "Unknown",
up->rpf.source_nexthop.interface ? up->rpf.source_nexthop
.interface->name
: "Unknown");
}
return HASHWALK_CONTINUE;
}
static int pim_update_upstream_nh(struct pim_instance *pim,
struct pim_nexthop_cache *pnc)
{
hash_walk(pnc->upstream_hash, pim_update_upstream_nh_helper, pim);
pim_zebra_update_all_interfaces(pim);
return 0;
}
uint32_t pim_compute_ecmp_hash(struct prefix *src, struct prefix *grp)
{
uint32_t hash_val;
uint32_t s = 0, g = 0;
if ((!src))
return 0;
switch (src->family) {
case AF_INET: {
s = src->u.prefix4.s_addr;
s = s == 0 ? 1 : s;
if (grp)
g = grp->u.prefix4.s_addr;
} break;
default:
break;
}
hash_val = jhash_2words(g, s, 101);
return hash_val;
}
static int pim_ecmp_nexthop_search(struct pim_instance *pim,
struct pim_nexthop_cache *pnc,
struct pim_nexthop *nexthop,
struct prefix *src, struct prefix *grp,
int neighbor_needed)
{
struct pim_neighbor *nbrs[MULTIPATH_NUM], *nbr = NULL;
struct interface *ifps[MULTIPATH_NUM];
struct nexthop *nh_node = NULL;
ifindex_t first_ifindex;
struct interface *ifp = NULL;
uint32_t hash_val = 0, mod_val = 0;
uint8_t nh_iter = 0, found = 0;
uint32_t i, num_nbrs = 0;
if (!pnc || !pnc->nexthop_num || !nexthop)
return 0;
memset(&nbrs, 0, sizeof(nbrs));
memset(&ifps, 0, sizeof(ifps));
// Current Nexthop is VALID, check to stay on the current path.
if (nexthop->interface && nexthop->interface->info
&& nexthop->mrib_nexthop_addr.u.prefix4.s_addr
!= PIM_NET_INADDR_ANY) {
/* User configured knob to explicitly switch
to new path is disabled or current path
metric is less than nexthop update.
*/
if (pim->ecmp_rebalance_enable == 0) {
uint8_t curr_route_valid = 0;
// Check if current nexthop is present in new updated
// Nexthop list.
// If the current nexthop is not valid, candidate to
// choose new Nexthop.
for (nh_node = pnc->nexthop; nh_node;
nh_node = nh_node->next) {
curr_route_valid = (nexthop->interface->ifindex
== nh_node->ifindex);
if (curr_route_valid)
break;
}
if (curr_route_valid
&& !pim_if_connected_to_source(nexthop->interface,
src->u.prefix4)) {
nbr = pim_neighbor_find(
nexthop->interface,
nexthop->mrib_nexthop_addr.u.prefix4);
if (!nbr
&& !if_is_loopback(nexthop->interface)) {
if (PIM_DEBUG_PIM_NHT)
zlog_debug(
"%s: current nexthop does not have nbr ",
__func__);
} else {
/* update metric even if the upstream
* neighbor stays unchanged
*/
nexthop->mrib_metric_preference =
pnc->distance;
nexthop->mrib_route_metric =
pnc->metric;
if (PIM_DEBUG_PIM_NHT) {
char src_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>",
src->u.prefix4,
src_str,
sizeof(src_str));
char grp_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>",
grp->u.prefix4,
grp_str,
sizeof(grp_str));
zlog_debug(
"%s: (%s,%s)(%s) current nexthop %s is valid, skipping new path selection",
__func__, src_str,
grp_str, pim->vrf->name,
nexthop->interface->name);
}
return 1;
}
}
}
}
/*
* Look up all interfaces and neighbors,
* store for later usage
*/
for (nh_node = pnc->nexthop, i = 0; nh_node;
nh_node = nh_node->next, i++) {
ifps[i] = if_lookup_by_index(nh_node->ifindex, pim->vrf_id);
if (ifps[i]) {
nbrs[i] = pim_neighbor_find(ifps[i],
nh_node->gate.ipv4);
if (nbrs[i] || pim_if_connected_to_source(ifps[i],
src->u.prefix4))
num_nbrs++;
}
}
if (pim->ecmp_enable) {
uint32_t consider = pnc->nexthop_num;
if (neighbor_needed && num_nbrs < consider)
consider = num_nbrs;
if (consider == 0)
return 0;
// PIM ECMP flag is enable then choose ECMP path.
hash_val = pim_compute_ecmp_hash(src, grp);
mod_val = hash_val % consider;
}
for (nh_node = pnc->nexthop; nh_node && (found == 0);
nh_node = nh_node->next) {
first_ifindex = nh_node->ifindex;
ifp = ifps[nh_iter];
if (!ifp) {
if (PIM_DEBUG_PIM_NHT) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", src->u.prefix4,
addr_str, sizeof(addr_str));
zlog_debug(
"%s %s: could not find interface for ifindex %d (address %s(%s))",
__FILE__, __func__, first_ifindex,
addr_str, pim->vrf->name);
}
if (nh_iter == mod_val)
mod_val++; // Select nexthpath
nh_iter++;
continue;
}
if (!ifp->info) {
if (PIM_DEBUG_PIM_NHT) {
char addr_str[INET_ADDRSTRLEN];
pim_inet4_dump("<addr?>", src->u.prefix4,
addr_str, sizeof(addr_str));
zlog_debug(
"%s: multicast not enabled on input interface %s(%s) (ifindex=%d, RPF for source %s)",
__func__, ifp->name, pim->vrf->name,
first_ifindex, addr_str);
}
if (nh_iter == mod_val)
mod_val++; // Select nexthpath
nh_iter++;
continue;
}
if (neighbor_needed
&& !pim_if_connected_to_source(ifp, src->u.prefix4)) {
nbr = nbrs[nh_iter];
if (!nbr && !if_is_loopback(ifp)) {
if (PIM_DEBUG_PIM_NHT)
zlog_debug(
"%s: pim nbr not found on input interface %s(%s)",
__func__, ifp->name,
pim->vrf->name);
if (nh_iter == mod_val)
mod_val++; // Select nexthpath
nh_iter++;
continue;
}
}
if (nh_iter == mod_val) {
nexthop->interface = ifp;
nexthop->mrib_nexthop_addr.family = AF_INET;
nexthop->mrib_nexthop_addr.prefixlen = IPV4_MAX_BITLEN;
nexthop->mrib_nexthop_addr.u.prefix4 =
nh_node->gate.ipv4;
nexthop->mrib_metric_preference = pnc->distance;
nexthop->mrib_route_metric = pnc->metric;
nexthop->last_lookup = src->u.prefix4;
nexthop->last_lookup_time = pim_time_monotonic_usec();
nexthop->nbr = nbr;
found = 1;
if (PIM_DEBUG_PIM_NHT) {
char buf[INET_ADDRSTRLEN];
char buf2[INET_ADDRSTRLEN];
char buf3[INET_ADDRSTRLEN];
pim_inet4_dump("<src?>", src->u.prefix4, buf2,
sizeof(buf2));
pim_inet4_dump("<grp?>", grp->u.prefix4, buf3,
sizeof(buf3));
pim_inet4_dump(
"<rpf?>",
nexthop->mrib_nexthop_addr.u.prefix4,
buf, sizeof(buf));
zlog_debug(
"%s: (%s,%s)(%s) selected nhop interface %s addr %s mod_val %u iter %d ecmp %d",
__func__, buf2, buf3, pim->vrf->name,
ifp->name, buf, mod_val, nh_iter,
pim->ecmp_enable);
}
}
nh_iter++;
}
if (found)
return 1;
else
return 0;
}
/* This API is used to parse Registered address nexthop update coming from Zebra
*/
int pim_parse_nexthop_update(ZAPI_CALLBACK_ARGS)
{
struct nexthop *nexthop;
struct nexthop *nhlist_head = NULL;
struct nexthop *nhlist_tail = NULL;
int i;
struct pim_rpf rpf;
struct pim_nexthop_cache *pnc = NULL;
struct pim_neighbor *nbr = NULL;
struct interface *ifp = NULL;
struct interface *ifp1 = NULL;
struct vrf *vrf = vrf_lookup_by_id(vrf_id);
struct pim_instance *pim;
struct zapi_route nhr;
if (!vrf)
return 0;
pim = vrf->info;
if (!zapi_nexthop_update_decode(zclient->ibuf, &nhr)) {
if (PIM_DEBUG_PIM_NHT)
zlog_debug(
"%s: Decode of nexthop update from zebra failed",
__func__);
return 0;
}
if (cmd == ZEBRA_NEXTHOP_UPDATE) {
prefix_copy(&rpf.rpf_addr, &nhr.prefix);
pnc = pim_nexthop_cache_find(pim, &rpf);
if (!pnc) {
if (PIM_DEBUG_PIM_NHT) {
char buf[PREFIX2STR_BUFFER];
prefix2str(&rpf.rpf_addr, buf, sizeof(buf));
zlog_debug(
"%s: Skipping NHT update, addr %s is not in local cached DB.",
__func__, buf);
}
return 0;
}
} else {
/*
* We do not currently handle ZEBRA_IMPORT_CHECK_UPDATE
*/
return 0;
}
pnc->last_update = pim_time_monotonic_usec();
if (nhr.nexthop_num) {
pnc->nexthop_num = 0; // Only increment for pim enabled rpf.
for (i = 0; i < nhr.nexthop_num; i++) {
nexthop = nexthop_from_zapi_nexthop(&nhr.nexthops[i]);
switch (nexthop->type) {
case NEXTHOP_TYPE_IPV4:
case NEXTHOP_TYPE_IPV4_IFINDEX:
case NEXTHOP_TYPE_IPV6:
case NEXTHOP_TYPE_BLACKHOLE:
break;
case NEXTHOP_TYPE_IFINDEX:
/*
* Connected route (i.e. no nexthop), use
* RPF address from nexthop cache (i.e.
* destination) as PIM nexthop.
*/
nexthop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
nexthop->gate.ipv4 =
pnc->rpf.rpf_addr.u.prefix4;
break;
case NEXTHOP_TYPE_IPV6_IFINDEX:
ifp1 = if_lookup_by_index(nexthop->ifindex,
pim->vrf_id);
if (!ifp1)
nbr = NULL;
else
nbr = pim_neighbor_find_if(ifp1);
/* Overwrite with Nbr address as NH addr */
if (nbr)
nexthop->gate.ipv4 = nbr->source_addr;
else {
// Mark nexthop address to 0 until PIM
// Nbr is resolved.
nexthop->gate.ipv4.s_addr =
PIM_NET_INADDR_ANY;
}
break;
}
ifp = if_lookup_by_index(nexthop->ifindex, pim->vrf_id);
if (!ifp) {
if (PIM_DEBUG_PIM_NHT) {
char buf[NEXTHOP_STRLEN];
zlog_debug(
"%s: could not find interface for ifindex %d(%s) (addr %s)",
__func__, nexthop->ifindex,
pim->vrf->name,
nexthop2str(nexthop, buf,
sizeof(buf)));
}
nexthop_free(nexthop);
continue;
}
if (PIM_DEBUG_PIM_NHT) {
char p_str[PREFIX2STR_BUFFER];
prefix2str(&nhr.prefix, p_str, sizeof(p_str));
zlog_debug(
"%s: NHT addr %s(%s) %d-nhop via %s(%s) type %d distance:%u metric:%u ",
__func__, p_str, pim->vrf->name, i + 1,
inet_ntoa(nexthop->gate.ipv4),
ifp->name, nexthop->type, nhr.distance,
nhr.metric);
}
if (!ifp->info) {
/*
* Though Multicast is not enabled on this
* Interface store it in database otheriwse we
* may miss this update and this will not cause
* any issue, because while choosing the path we
* are ommitting the Interfaces which are not
* multicast enabled
*/
if (PIM_DEBUG_PIM_NHT) {
char buf[NEXTHOP_STRLEN];
zlog_debug(
"%s: multicast not enabled on input interface %s(%s) (ifindex=%d, addr %s)",
__func__, ifp->name,
pim->vrf->name,
nexthop->ifindex,
nexthop2str(nexthop, buf,
sizeof(buf)));
}
}
if (nhlist_tail) {
nhlist_tail->next = nexthop;
nhlist_tail = nexthop;
} else {
nhlist_tail = nexthop;
nhlist_head = nexthop;
}
// Only keep track of nexthops which are PIM enabled.
pnc->nexthop_num++;
}
/* Reset existing pnc->nexthop before assigning new list */
nexthops_free(pnc->nexthop);
pnc->nexthop = nhlist_head;
if (pnc->nexthop_num) {
pnc->flags |= PIM_NEXTHOP_VALID;
pnc->distance = nhr.distance;
pnc->metric = nhr.metric;
}
} else {
pnc->flags &= ~PIM_NEXTHOP_VALID;
pnc->nexthop_num = nhr.nexthop_num;
nexthops_free(pnc->nexthop);
pnc->nexthop = NULL;
}
SET_FLAG(pnc->flags, PIM_NEXTHOP_ANSWER_RECEIVED);
if (PIM_DEBUG_PIM_NHT) {
char buf[PREFIX2STR_BUFFER];
prefix2str(&nhr.prefix, buf, sizeof(buf));
zlog_debug(
"%s: NHT Update for %s(%s) num_nh %d num_pim_nh %d vrf:%u up %ld rp %d",
__func__, buf, pim->vrf->name, nhr.nexthop_num,
pnc->nexthop_num, vrf_id, pnc->upstream_hash->count,
listcount(pnc->rp_list));
}
pim_rpf_set_refresh_time(pim);
if (listcount(pnc->rp_list))
pim_update_rp_nh(pim, pnc);
if (pnc->upstream_hash->count)
pim_update_upstream_nh(pim, pnc);
return 0;
}
int pim_ecmp_nexthop_lookup(struct pim_instance *pim,
struct pim_nexthop *nexthop, struct prefix *src,
struct prefix *grp, int neighbor_needed)
{
struct pim_nexthop_cache *pnc;
struct pim_zlookup_nexthop nexthop_tab[MULTIPATH_NUM];
struct pim_neighbor *nbrs[MULTIPATH_NUM], *nbr = NULL;
struct pim_rpf rpf;
int num_ifindex;
struct interface *ifps[MULTIPATH_NUM], *ifp;
int first_ifindex;
int found = 0;
uint8_t i = 0;
uint32_t hash_val = 0, mod_val = 0;
uint32_t num_nbrs = 0;
char addr_str[PREFIX_STRLEN];
if (PIM_DEBUG_PIM_NHT) {
pim_inet4_dump("<addr?>", src->u.prefix4, addr_str,
sizeof(addr_str));
zlog_debug("%s: Looking up: %s(%s), last lookup time: %lld",
__func__, addr_str, pim->vrf->name,
nexthop->last_lookup_time);
}
memset(&rpf, 0, sizeof(struct pim_rpf));
rpf.rpf_addr.family = AF_INET;
rpf.rpf_addr.prefixlen = IPV4_MAX_BITLEN;
rpf.rpf_addr.u.prefix4 = src->u.prefix4;
pnc = pim_nexthop_cache_find(pim, &rpf);
if (pnc) {
if (CHECK_FLAG(pnc->flags, PIM_NEXTHOP_ANSWER_RECEIVED))
return pim_ecmp_nexthop_search(pim, pnc, nexthop, src, grp,
neighbor_needed);
}
memset(nexthop_tab, 0,
sizeof(struct pim_zlookup_nexthop) * MULTIPATH_NUM);
num_ifindex =
zclient_lookup_nexthop(pim, nexthop_tab, MULTIPATH_NUM,
src->u.prefix4, PIM_NEXTHOP_LOOKUP_MAX);
if (num_ifindex < 1) {
if (PIM_DEBUG_PIM_NHT)
zlog_warn(
"%s: could not find nexthop ifindex for address %s(%s)",
__func__, addr_str, pim->vrf->name);
return 0;
}
memset(&nbrs, 0, sizeof(nbrs));
memset(&ifps, 0, sizeof(ifps));
/*
* Look up all interfaces and neighbors,
* store for later usage
*/
for (i = 0; i < num_ifindex; i++) {
ifps[i] = if_lookup_by_index(nexthop_tab[i].ifindex,
pim->vrf_id);
if (ifps[i]) {
nbrs[i] = pim_neighbor_find(
ifps[i], nexthop_tab[i].nexthop_addr.u.prefix4);
if (nbrs[i]
|| pim_if_connected_to_source(ifps[i],
src->u.prefix4))
num_nbrs++;
}
}
// If PIM ECMP enable then choose ECMP path.
if (pim->ecmp_enable) {
uint32_t consider = num_ifindex;
if (neighbor_needed && num_nbrs < consider)
consider = num_nbrs;
if (consider == 0)
return 0;
hash_val = pim_compute_ecmp_hash(src, grp);
mod_val = hash_val % consider;
if (PIM_DEBUG_PIM_NHT_DETAIL)
zlog_debug("%s: hash_val %u mod_val %u", __func__,
hash_val, mod_val);
}
i = 0;
while (!found && (i < num_ifindex)) {
first_ifindex = nexthop_tab[i].ifindex;
ifp = ifps[i];
if (!ifp) {
if (PIM_DEBUG_PIM_NHT)
zlog_debug(
"%s %s: could not find interface for ifindex %d (address %s(%s))",
__FILE__, __func__, first_ifindex,