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-rw-r--r--pimd/pim_nht.c1064
1 files changed, 1064 insertions, 0 deletions
diff --git a/pimd/pim_nht.c b/pimd/pim_nht.c
new file mode 100644
index 0000000..f9a9aeb
--- /dev/null
+++ b/pimd/pim_nht.c
@@ -0,0 +1,1064 @@
+/*
+ * 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 "lib/printfrr.h"
+
+#include "pimd.h"
+#include "pimd/pim_nht.h"
+#include "pim_instance.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"
+#include "pim_addr.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;
+
+ pim_addr_to_prefix(&p, pnc->rpf.rpf_addr);
+ ret = zclient_send_rnh(zclient, command, &p, SAFI_UNICAST, false, false,
+ pim->vrf->vrf_id);
+ if (ret == ZCLIENT_SEND_FAILURE)
+ zlog_warn("sendmsg_nexthop: zclient_send_message() failed");
+
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: NHT %sregistered addr %pFX(%s) with Zebra ret:%d ",
+ __func__,
+ (command == ZEBRA_NEXTHOP_REGISTER) ? " " : "de", &p,
+ 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 = rpf->rpf_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];
+
+ pnc = XCALLOC(MTYPE_PIM_NEXTHOP_CACHE,
+ sizeof(struct pim_nexthop_cache));
+ pnc->rpf.rpf_addr = rpf_addr->rpf_addr;
+
+ pnc = hash_get(pim->rpf_hash, pnc, hash_alloc_intern);
+
+ pnc->rp_list = list_new();
+ pnc->rp_list->cmp = pim_rp_list_cmp;
+
+ snprintfrr(hash_name, sizeof(hash_name), "PNC %pPA(%s) Upstream Hash",
+ &pnc->rpf.rpf_addr, pim->vrf->name);
+ pnc->upstream_hash = hash_create_size(8192, pim_upstream_hash_key,
+ pim_upstream_equal, hash_name);
+
+ return pnc;
+}
+
+static struct pim_nexthop_cache *pim_nht_get(struct pim_instance *pim,
+ pim_addr addr)
+{
+ struct pim_nexthop_cache *pnc = NULL;
+ struct pim_rpf rpf;
+ struct zclient *zclient = NULL;
+
+ zclient = pim_zebra_zclient_get();
+ memset(&rpf, 0, sizeof(rpf));
+ rpf.rpf_addr = addr;
+
+ 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_DETAIL)
+ zlog_debug(
+ "%s: NHT cache and zebra notification added for %pPA(%s)",
+ __func__, &addr, pim->vrf->name);
+ }
+
+ return pnc;
+}
+
+/* TBD: this does several distinct things and should probably be split up.
+ * (checking state vs. returning pnc vs. adding upstream vs. adding rp)
+ */
+int pim_find_or_track_nexthop(struct pim_instance *pim, pim_addr addr,
+ struct pim_upstream *up, struct rp_info *rp,
+ struct pim_nexthop_cache *out_pnc)
+{
+ struct pim_nexthop_cache *pnc;
+ struct listnode *ch_node = NULL;
+
+ pnc = pim_nht_get(pim, addr);
+
+ assertf(up || rp, "addr=%pPA", &addr);
+
+ 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)
+ (void)hash_get(pnc->upstream_hash, up, hash_alloc_intern);
+
+ 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_nht_bsr_add(struct pim_instance *pim, pim_addr addr)
+{
+ struct pim_nexthop_cache *pnc;
+
+ pnc = pim_nht_get(pim, addr);
+
+ pnc->bsr_count++;
+}
+
+static void pim_nht_drop_maybe(struct pim_instance *pim,
+ struct pim_nexthop_cache *pnc)
+{
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: NHT %pPA(%s) rp_list count:%d upstream count:%ld BSR count:%u",
+ __func__, &pnc->rpf.rpf_addr, pim->vrf->name,
+ pnc->rp_list->count, pnc->upstream_hash->count,
+ pnc->bsr_count);
+
+ if (pnc->rp_list->count == 0 && pnc->upstream_hash->count == 0
+ && pnc->bsr_count == 0) {
+ struct zclient *zclient = pim_zebra_zclient_get();
+
+ 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);
+ }
+}
+
+void pim_delete_tracked_nexthop(struct pim_instance *pim, pim_addr addr,
+ struct pim_upstream *up, struct rp_info *rp)
+{
+ struct pim_nexthop_cache *pnc = NULL;
+ struct pim_nexthop_cache lookup;
+ struct pim_upstream *upstream = NULL;
+
+ /* Remove from RPF hash if it is the last entry */
+ lookup.rpf.rpf_addr = addr;
+ pnc = hash_lookup(pim->rpf_hash, &lookup);
+ if (!pnc) {
+ zlog_warn("attempting to delete nonexistent NHT entry %pPA",
+ &addr);
+ return;
+ }
+
+ 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 (!pim_addr_is_any(upstream->sg.src))
+ continue;
+
+ pim_addr_to_prefix(&grp, 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);
+
+ pim_nht_drop_maybe(pim, pnc);
+}
+
+void pim_nht_bsr_del(struct pim_instance *pim, pim_addr addr)
+{
+ struct pim_nexthop_cache *pnc = NULL;
+ struct pim_nexthop_cache lookup;
+
+ /*
+ * Nothing to do here if the address to unregister
+ * is 0.0.0.0 as that the BSR has not been registered
+ * for tracking yet.
+ */
+ if (pim_addr_is_any(addr))
+ return;
+
+ lookup.rpf.rpf_addr = addr;
+
+ pnc = hash_lookup(pim->rpf_hash, &lookup);
+
+ if (!pnc) {
+ zlog_warn("attempting to delete nonexistent NHT BSR entry %pPA",
+ &addr);
+ return;
+ }
+
+ assertf(pnc->bsr_count > 0, "addr=%pPA", &addr);
+ pnc->bsr_count--;
+
+ pim_nht_drop_maybe(pim, pnc);
+}
+
+bool pim_nht_bsr_rpf_check(struct pim_instance *pim, pim_addr bsr_addr,
+ struct interface *src_ifp, pim_addr src_ip)
+{
+ struct pim_nexthop_cache *pnc = NULL;
+ struct pim_nexthop_cache lookup;
+ struct pim_neighbor *nbr = NULL;
+ struct nexthop *nh;
+ struct interface *ifp;
+
+ lookup.rpf.rpf_addr = bsr_addr;
+
+ pnc = hash_lookup(pim->rpf_hash, &lookup);
+ if (!pnc || !CHECK_FLAG(pnc->flags, PIM_NEXTHOP_ANSWER_RECEIVED)) {
+ /* BSM from a new freshly registered BSR - do a synchronous
+ * zebra query since otherwise we'd drop the first packet,
+ * leading to additional delay in picking up BSM data
+ */
+
+ /* FIXME: this should really be moved into a generic NHT
+ * function that does "add and get immediate result" or maybe
+ * "check cache or get immediate result." But until that can
+ * be worked in, here's a copy of the code below :(
+ */
+ struct pim_zlookup_nexthop nexthop_tab[router->multipath];
+ ifindex_t i;
+ struct interface *ifp = NULL;
+ int num_ifindex;
+
+ memset(nexthop_tab, 0, sizeof(nexthop_tab));
+ num_ifindex = zclient_lookup_nexthop(
+ pim, nexthop_tab, router->multipath, bsr_addr,
+ PIM_NEXTHOP_LOOKUP_MAX);
+
+ if (num_ifindex <= 0)
+ return false;
+
+ for (i = 0; i < num_ifindex; i++) {
+ struct pim_zlookup_nexthop *znh = &nexthop_tab[i];
+
+ /* pim_zlookup_nexthop has no ->type */
+
+ /* 1:1 match code below with znh instead of nh */
+ ifp = if_lookup_by_index(znh->ifindex,
+ pim->vrf->vrf_id);
+
+ if (!ifp || !ifp->info)
+ continue;
+
+ if (if_is_loopback(ifp) && if_is_loopback(src_ifp))
+ return true;
+
+ nbr = pim_neighbor_find(ifp, znh->nexthop_addr);
+ if (!nbr)
+ continue;
+
+ return znh->ifindex == src_ifp->ifindex &&
+ (!pim_addr_cmp(znh->nexthop_addr, src_ip));
+ }
+ return false;
+ }
+
+ if (!CHECK_FLAG(pnc->flags, PIM_NEXTHOP_VALID))
+ return false;
+
+ /* if we accept BSMs from more than one ECMP nexthop, this will cause
+ * BSM message "multiplication" for each ECMP hop. i.e. if you have
+ * 4-way ECMP and 4 hops you end up with 256 copies of each BSM
+ * message.
+ *
+ * so... only accept the first (IPv4) valid nexthop as source.
+ */
+
+ for (nh = pnc->nexthop; nh; nh = nh->next) {
+ pim_addr nhaddr;
+
+ switch (nh->type) {
+#if PIM_IPV == 4
+ case NEXTHOP_TYPE_IPV4:
+ if (nh->ifindex == IFINDEX_INTERNAL)
+ continue;
+
+ /* fallthru */
+ case NEXTHOP_TYPE_IPV4_IFINDEX:
+ nhaddr = nh->gate.ipv4;
+ break;
+#else
+ case NEXTHOP_TYPE_IPV6:
+ if (nh->ifindex == IFINDEX_INTERNAL)
+ continue;
+
+ /* fallthru */
+ case NEXTHOP_TYPE_IPV6_IFINDEX:
+ nhaddr = nh->gate.ipv6;
+ break;
+#endif
+ case NEXTHOP_TYPE_IFINDEX:
+ nhaddr = bsr_addr;
+ break;
+
+ default:
+ continue;
+ }
+
+ ifp = if_lookup_by_index(nh->ifindex, pim->vrf->vrf_id);
+ if (!ifp || !ifp->info)
+ continue;
+
+ if (if_is_loopback(ifp) && if_is_loopback(src_ifp))
+ return true;
+
+ /* MRIB (IGP) may be pointing at a router where PIM is down */
+ nbr = pim_neighbor_find(ifp, nhaddr);
+ if (!nbr)
+ continue;
+
+ return nh->ifindex == src_ifp->ifindex &&
+ (!pim_addr_cmp(nhaddr, src_ip));
+ }
+ 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 = PIMADDR_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 (pim_rpf_addr_is_inaddr_any(&rp_info->rp))
+ 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_CHANGED)
+ 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;
+
+ if (!src)
+ return 0;
+
+ hash_val = prefix_hash_key(src);
+ if (grp)
+ hash_val ^= prefix_hash_key(grp);
+ return hash_val;
+}
+
+static int pim_ecmp_nexthop_search(struct pim_instance *pim,
+ struct pim_nexthop_cache *pnc,
+ struct pim_nexthop *nexthop, pim_addr src,
+ struct prefix *grp, int neighbor_needed)
+{
+ struct pim_neighbor *nbrs[router->multipath], *nbr = NULL;
+ struct interface *ifps[router->multipath];
+ 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;
+
+ pim_addr nh_addr = nexthop->mrib_nexthop_addr;
+ pim_addr grp_addr = pim_addr_from_prefix(grp);
+
+ 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 &&
+ (!pim_addr_is_any(nh_addr))) {
+ /* 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)) {
+ nbr = pim_neighbor_find(
+ nexthop->interface,
+ nexthop->mrib_nexthop_addr);
+ 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)
+ zlog_debug(
+ "%s: (%pPA,%pPA)(%s) current nexthop %s is valid, skipping new path selection",
+ __func__, &src,
+ &grp_addr,
+ 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->vrf_id);
+ if (ifps[i]) {
+#if PIM_IPV == 4
+ pim_addr nhaddr = nh_node->gate.ipv4;
+#else
+ pim_addr nhaddr = nh_node->gate.ipv6;
+#endif
+ nbrs[i] = pim_neighbor_find(ifps[i], nhaddr);
+ if (nbrs[i] || pim_if_connected_to_source(ifps[i], src))
+ num_nbrs++;
+ }
+ }
+ if (pim->ecmp_enable) {
+ struct prefix src_pfx;
+ 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.
+ pim_addr_to_prefix(&src_pfx, src);
+ hash_val = pim_compute_ecmp_hash(&src_pfx, 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)
+ zlog_debug(
+ "%s %s: could not find interface for ifindex %d (address %pPA(%s))",
+ __FILE__, __func__, first_ifindex, &src,
+ pim->vrf->name);
+ if (nh_iter == mod_val)
+ mod_val++; // Select nexthpath
+ nh_iter++;
+ continue;
+ }
+ if (!ifp->info) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: multicast not enabled on input interface %s(%s) (ifindex=%d, RPF for source %pPA)",
+ __func__, ifp->name, pim->vrf->name,
+ first_ifindex, &src);
+ if (nh_iter == mod_val)
+ mod_val++; // Select nexthpath
+ nh_iter++;
+ continue;
+ }
+
+ if (neighbor_needed && !pim_if_connected_to_source(ifp, src)) {
+ 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;
+#if PIM_IPV == 4
+ nexthop->mrib_nexthop_addr = nh_node->gate.ipv4;
+#else
+ nexthop->mrib_nexthop_addr = nh_node->gate.ipv6;
+#endif
+ nexthop->mrib_metric_preference = pnc->distance;
+ nexthop->mrib_route_metric = pnc->metric;
+ nexthop->last_lookup = src;
+ nexthop->last_lookup_time = pim_time_monotonic_usec();
+ nexthop->nbr = nbr;
+ found = 1;
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: (%pPA,%pPA)(%s) selected nhop interface %s addr %pPAs mod_val %u iter %d ecmp %d",
+ __func__, &src, &grp_addr,
+ pim->vrf->name, ifp->name, &nh_addr,
+ 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 interface *ifp = NULL;
+ struct vrf *vrf = vrf_lookup_by_id(vrf_id);
+ struct pim_instance *pim;
+ struct zapi_route nhr;
+ struct prefix match;
+
+ if (!vrf)
+ return 0;
+ pim = vrf->info;
+
+ if (!zapi_nexthop_update_decode(zclient->ibuf, &match, &nhr)) {
+ zlog_err("%s: Decode of nexthop update from zebra failed",
+ __func__);
+ return 0;
+ }
+
+ if (cmd == ZEBRA_NEXTHOP_UPDATE) {
+ rpf.rpf_addr = pim_addr_from_prefix(&match);
+ pnc = pim_nexthop_cache_find(pim, &rpf);
+ if (!pnc) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: Skipping NHT update, addr %pPA is not in local cached DB.",
+ __func__, &rpf.rpf_addr);
+ 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_IFINDEX:
+ /*
+ * Connected route (i.e. no nexthop), use
+ * RPF address from nexthop cache (i.e.
+ * destination) as PIM nexthop.
+ */
+#if PIM_IPV == 4
+ nexthop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
+ nexthop->gate.ipv4 = pnc->rpf.rpf_addr;
+#else
+ nexthop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
+ nexthop->gate.ipv6 = pnc->rpf.rpf_addr;
+#endif
+ break;
+#if PIM_IPV == 4
+ /* RFC5549 IPv4-over-IPv6 nexthop handling:
+ * if we get an IPv6 nexthop in IPv4 PIM, hunt down a
+ * PIM neighbor and use that instead.
+ */
+ case NEXTHOP_TYPE_IPV6_IFINDEX: {
+ struct interface *ifp1 = NULL;
+ struct pim_neighbor *nbr = NULL;
+
+ ifp1 = if_lookup_by_index(nexthop->ifindex,
+ pim->vrf->vrf_id);
+
+ if (!ifp1)
+ nbr = NULL;
+ else
+ /* FIXME: should really use nbr's
+ * secondary address list here
+ */
+ 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 = PIMADDR_ANY;
+
+ break;
+ }
+#else
+ case NEXTHOP_TYPE_IPV6_IFINDEX:
+#endif
+ case NEXTHOP_TYPE_IPV6:
+ case NEXTHOP_TYPE_IPV4:
+ case NEXTHOP_TYPE_IPV4_IFINDEX:
+ case NEXTHOP_TYPE_BLACKHOLE:
+ /* nothing to do for the other nexthop types */
+ break;
+ }
+
+ ifp = if_lookup_by_index(nexthop->ifindex,
+ pim->vrf->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) {
+#if PIM_IPV == 4
+ pim_addr nhaddr = nexthop->gate.ipv4;
+#else
+ pim_addr nhaddr = nexthop->gate.ipv6;
+#endif
+ zlog_debug(
+ "%s: NHT addr %pFX(%s) %d-nhop via %pPA(%s) type %d distance:%u metric:%u ",
+ __func__, &match, pim->vrf->name, i + 1,
+ &nhaddr, 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)
+ zlog_debug(
+ "%s: NHT Update for %pFX(%s) num_nh %d num_pim_nh %d vrf:%u up %ld rp %d",
+ __func__, &match, 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, pim_addr src,
+ struct prefix *grp, int neighbor_needed)
+{
+ struct pim_nexthop_cache *pnc;
+ struct pim_zlookup_nexthop nexthop_tab[router->multipath];
+ struct pim_neighbor *nbrs[router->multipath], *nbr = NULL;
+ struct pim_rpf rpf;
+ int num_ifindex;
+ struct interface *ifps[router->multipath], *ifp;
+ int first_ifindex;
+ int found = 0;
+ uint8_t i = 0;
+ uint32_t hash_val = 0, mod_val = 0;
+ uint32_t num_nbrs = 0;
+
+ if (PIM_DEBUG_PIM_NHT_DETAIL)
+ zlog_debug("%s: Looking up: %pPA(%s), last lookup time: %lld",
+ __func__, &src, pim->vrf->name,
+ nexthop->last_lookup_time);
+
+ rpf.rpf_addr = src;
+
+ 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) * router->multipath);
+ num_ifindex =
+ zclient_lookup_nexthop(pim, nexthop_tab, router->multipath, src,
+ PIM_NEXTHOP_LOOKUP_MAX);
+ if (num_ifindex < 1) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_warn(
+ "%s: could not find nexthop ifindex for address %pPA(%s)",
+ __func__, &src, 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->vrf_id);
+ if (ifps[i]) {
+ nbrs[i] = pim_neighbor_find(
+ ifps[i], nexthop_tab[i].nexthop_addr);
+ if (nbrs[i] || pim_if_connected_to_source(ifps[i], src))
+ num_nbrs++;
+ }
+ }
+
+ // If PIM ECMP enable then choose ECMP path.
+ if (pim->ecmp_enable) {
+ struct prefix src_pfx;
+ uint32_t consider = num_ifindex;
+
+ if (neighbor_needed && num_nbrs < consider)
+ consider = num_nbrs;
+
+ if (consider == 0)
+ return 0;
+
+ pim_addr_to_prefix(&src_pfx, src);
+ hash_val = pim_compute_ecmp_hash(&src_pfx, 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 %pPA(%s))",
+ __FILE__, __func__, first_ifindex, &src,
+ pim->vrf->name);
+ if (i == mod_val)
+ mod_val++;
+ i++;
+ continue;
+ }
+
+ if (!ifp->info) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: multicast not enabled on input interface %s(%s) (ifindex=%d, RPF for source %pPA)",
+ __func__, ifp->name, pim->vrf->name,
+ first_ifindex, &src);
+ if (i == mod_val)
+ mod_val++;
+ i++;
+ continue;
+ }
+ if (neighbor_needed && !pim_if_connected_to_source(ifp, src)) {
+ nbr = nbrs[i];
+ if (PIM_DEBUG_PIM_NHT_DETAIL)
+ zlog_debug("ifp name: %s(%s), pim nbr: %p",
+ ifp->name, pim->vrf->name, nbr);
+ if (!nbr && !if_is_loopback(ifp)) {
+ if (i == mod_val)
+ mod_val++;
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: NBR (%pPA) not found on input interface %s(%s) (RPF for source %pPA)",
+ __func__,
+ &nexthop_tab[i].nexthop_addr,
+ ifp->name, pim->vrf->name,
+ &src);
+ i++;
+ continue;
+ }
+ }
+
+ if (i == mod_val) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: found nhop %pPA for addr %pPA interface %s(%s) metric %d dist %d",
+ __func__, &nexthop_tab[i].nexthop_addr,
+ &src, ifp->name, pim->vrf->name,
+ nexthop_tab[i].route_metric,
+ nexthop_tab[i].protocol_distance);
+ /* update nexthop data */
+ nexthop->interface = ifp;
+ nexthop->mrib_nexthop_addr =
+ nexthop_tab[i].nexthop_addr;
+ nexthop->mrib_metric_preference =
+ nexthop_tab[i].protocol_distance;
+ nexthop->mrib_route_metric =
+ nexthop_tab[i].route_metric;
+ nexthop->last_lookup = src;
+ nexthop->last_lookup_time = pim_time_monotonic_usec();
+ nexthop->nbr = nbr;
+ found = 1;
+ }
+ i++;
+ }
+
+ if (found)
+ return 1;
+ else
+ return 0;
+}
+
+int pim_ecmp_fib_lookup_if_vif_index(struct pim_instance *pim, pim_addr src,
+ struct prefix *grp)
+{
+ struct pim_nexthop nhop;
+ int vif_index;
+ ifindex_t ifindex;
+
+ memset(&nhop, 0, sizeof(nhop));
+ if (!pim_ecmp_nexthop_lookup(pim, &nhop, src, grp, 1)) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: could not find nexthop ifindex for address %pPA(%s)",
+ __func__, &src, pim->vrf->name);
+ return -1;
+ }
+
+ ifindex = nhop.interface->ifindex;
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: found nexthop ifindex=%d (interface %s(%s)) for address %pPA",
+ __func__, ifindex,
+ ifindex2ifname(ifindex, pim->vrf->vrf_id),
+ pim->vrf->name, &src);
+
+ vif_index = pim_if_find_vifindex_by_ifindex(pim, ifindex);
+
+ if (vif_index < 0) {
+ if (PIM_DEBUG_PIM_NHT) {
+ zlog_debug(
+ "%s: low vif_index=%d(%s) < 1 nexthop for address %pPA",
+ __func__, vif_index, pim->vrf->name, &src);
+ }
+ return -2;
+ }
+
+ return vif_index;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 09:07:31 +0000