1 files changed, 499 insertions, 0 deletions

diff --git a/ospfd/ospf_neighbor.c b/ospfd/ospf_neighbor.c
new file mode 100644
index 0000000..c238f05
--- /dev/null
+++ b/ospfd/ospf_neighbor.c
@@ -0,0 +1,499 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OSPF Neighbor functions.
+ * Copyright (C) 1999, 2000 Toshiaki Takada
+ */
+
+#include <zebra.h>
+
+#include "lib/bfd.h"
+#include "linklist.h"
+#include "prefix.h"
+#include "memory.h"
+#include "command.h"
+#include "frrevent.h"
+#include "stream.h"
+#include "table.h"
+#include "log.h"
+#include "json.h"
+
+#include "ospfd/ospfd.h"
+#include "ospfd/ospf_interface.h"
+#include "ospfd/ospf_asbr.h"
+#include "ospfd/ospf_lsa.h"
+#include "ospfd/ospf_lsdb.h"
+#include "ospfd/ospf_neighbor.h"
+#include "ospfd/ospf_nsm.h"
+#include "ospfd/ospf_packet.h"
+#include "ospfd/ospf_network.h"
+#include "ospfd/ospf_flood.h"
+#include "ospfd/ospf_dump.h"
+#include "ospfd/ospf_bfd.h"
+#include "ospfd/ospf_gr.h"
+
+/* Fill in the the 'key' as appropriate to retrieve the entry for nbr
+ * from the ospf_interface's nbrs table. Indexed by interface address
+ * for all cases except Virtual-link and PointToPoint interfaces, where
+ * neighbours are indexed by router-ID instead.
+ */
+static void ospf_nbr_key(struct ospf_interface *oi, struct ospf_neighbor *nbr,
+			 struct prefix *key)
+{
+	key->family = AF_INET;
+	key->prefixlen = IPV4_MAX_BITLEN;
+
+	/* vlinks are indexed by router-id */
+	if (oi->type == OSPF_IFTYPE_VIRTUALLINK
+	    || oi->type == OSPF_IFTYPE_POINTOPOINT)
+		key->u.prefix4 = nbr->router_id;
+	else
+		key->u.prefix4 = nbr->src;
+	return;
+}
+
+struct ospf_neighbor *ospf_nbr_new(struct ospf_interface *oi)
+{
+	struct ospf_neighbor *nbr;
+
+	/* Allcate new neighbor. */
+	nbr = XCALLOC(MTYPE_OSPF_NEIGHBOR, sizeof(struct ospf_neighbor));
+
+	/* Relate neighbor to the interface. */
+	nbr->oi = oi;
+
+	/* Set default values. */
+	nbr->state = NSM_Down;
+
+	/* Set inheritance values. */
+	nbr->v_inactivity = OSPF_IF_PARAM(oi, v_wait);
+	nbr->v_db_desc = OSPF_IF_PARAM(oi, retransmit_interval);
+	nbr->v_ls_req = OSPF_IF_PARAM(oi, retransmit_interval);
+	nbr->v_ls_upd = OSPF_IF_PARAM(oi, retransmit_interval);
+	nbr->priority = -1;
+
+	/* DD flags. */
+	nbr->dd_flags = OSPF_DD_FLAG_MS | OSPF_DD_FLAG_M | OSPF_DD_FLAG_I;
+
+	/* Last received and sent DD. */
+	nbr->last_send = NULL;
+
+	nbr->nbr_nbma = NULL;
+
+	ospf_lsdb_init(&nbr->db_sum);
+	ospf_lsdb_init(&nbr->ls_rxmt);
+	ospf_lsdb_init(&nbr->ls_req);
+
+	nbr->crypt_seqnum = 0;
+
+	/* Initialize GR Helper info*/
+	nbr->gr_helper_info.recvd_grace_period = 0;
+	nbr->gr_helper_info.actual_grace_period = 0;
+	nbr->gr_helper_info.gr_helper_status = OSPF_GR_NOT_HELPER;
+	nbr->gr_helper_info.helper_exit_reason = OSPF_GR_HELPER_EXIT_NONE;
+	nbr->gr_helper_info.gr_restart_reason = OSPF_GR_UNKNOWN_RESTART;
+
+	return nbr;
+}
+
+void ospf_nbr_free(struct ospf_neighbor *nbr)
+{
+	/* Free DB summary list. */
+	if (ospf_db_summary_count(nbr))
+		ospf_db_summary_clear(nbr);
+	/* ospf_db_summary_delete_all (nbr); */
+
+	/* Free ls request list. */
+	if (ospf_ls_request_count(nbr))
+		ospf_ls_request_delete_all(nbr);
+
+	/* Free retransmit list. */
+	if (ospf_ls_retransmit_count(nbr))
+		ospf_ls_retransmit_clear(nbr);
+
+	/* Cleanup LSDBs. */
+	ospf_lsdb_cleanup(&nbr->db_sum);
+	ospf_lsdb_cleanup(&nbr->ls_req);
+	ospf_lsdb_cleanup(&nbr->ls_rxmt);
+
+	/* Clear last send packet. */
+	if (nbr->last_send)
+		ospf_packet_free(nbr->last_send);
+
+	if (nbr->nbr_nbma) {
+		nbr->nbr_nbma->nbr = NULL;
+		nbr->nbr_nbma = NULL;
+	}
+
+	/* Cancel all timers. */
+	EVENT_OFF(nbr->t_inactivity);
+	EVENT_OFF(nbr->t_db_desc);
+	EVENT_OFF(nbr->t_ls_req);
+	EVENT_OFF(nbr->t_ls_upd);
+
+	/* Cancel all events. */ /* Thread lookup cost would be negligible. */
+	event_cancel_event(master, nbr);
+
+	bfd_sess_free(&nbr->bfd_session);
+
+	EVENT_OFF(nbr->gr_helper_info.t_grace_timer);
+
+	nbr->oi = NULL;
+	XFREE(MTYPE_OSPF_NEIGHBOR, nbr);
+}
+
+/* Delete specified OSPF neighbor from interface. */
+void ospf_nbr_delete(struct ospf_neighbor *nbr)
+{
+	struct ospf_interface *oi;
+	struct route_node *rn;
+	struct prefix p;
+
+	oi = nbr->oi;
+
+	/* get appropriate prefix 'key' */
+	ospf_nbr_key(oi, nbr, &p);
+
+	rn = route_node_lookup(oi->nbrs, &p);
+	if (rn) {
+		/* If lookup for a NBR succeeds, the leaf route_node could
+		 * only exist because there is (or was) a nbr there.
+		 * If the nbr was deleted, the leaf route_node should have
+		 * lost its last refcount too, and be deleted.
+		 * Therefore a looked-up leaf route_node in nbrs table
+		 * should never have NULL info.
+		 */
+		assert(rn->info);
+
+		if (rn->info) {
+			rn->info = NULL;
+			route_unlock_node(rn);
+		} else
+			zlog_info("Can't find neighbor %pI4 in the interface %s",
+				  &nbr->src, IF_NAME(oi));
+
+		route_unlock_node(rn);
+	} else {
+		/*
+		 * This neighbor was not found, but before we move on and
+		 * free the neighbor structre, make sure that it was not
+		 * indexed incorrectly and ended up in the "worng" place
+		 */
+
+		/* Reverse the lookup rules */
+		if (oi->type == OSPF_IFTYPE_VIRTUALLINK
+		    || oi->type == OSPF_IFTYPE_POINTOPOINT)
+			p.u.prefix4 = nbr->src;
+		else
+			p.u.prefix4 = nbr->router_id;
+
+		rn = route_node_lookup(oi->nbrs, &p);
+		if (rn) {
+			/* We found the neighbor!
+			 * Now make sure it is not the exact same neighbor
+			 * structure that we are about to free
+			 */
+			if (nbr == rn->info) {
+				/* Same neighbor, drop the reference to it */
+				rn->info = NULL;
+				route_unlock_node(rn);
+			}
+			route_unlock_node(rn);
+		}
+	}
+
+	/* Free ospf_neighbor structure. */
+	ospf_nbr_free(nbr);
+}
+
+/* Check myself is in the neighbor list. */
+int ospf_nbr_bidirectional(struct in_addr *router_id, struct in_addr *neighbors,
+			   int size)
+{
+	int i;
+	int max;
+
+	max = size / sizeof(struct in_addr);
+
+	for (i = 0; i < max; i++)
+		if (IPV4_ADDR_SAME(router_id, &neighbors[i]))
+			return 1;
+
+	return 0;
+}
+
+/* reset nbr_self */
+void ospf_nbr_self_reset(struct ospf_interface *oi, struct in_addr router_id)
+{
+	if (oi->nbr_self)
+		ospf_nbr_delete(oi->nbr_self);
+
+	oi->nbr_self = ospf_nbr_new(oi);
+	ospf_nbr_add_self(oi, router_id);
+}
+
+/* Add self to nbr list. */
+void ospf_nbr_add_self(struct ospf_interface *oi, struct in_addr router_id)
+{
+	struct prefix p;
+	struct route_node *rn;
+
+	if (!oi->nbr_self)
+		oi->nbr_self = ospf_nbr_new(oi);
+
+	/* Initial state */
+	oi->nbr_self->address = *oi->address;
+	oi->nbr_self->priority = OSPF_IF_PARAM(oi, priority);
+	oi->nbr_self->router_id = router_id;
+	oi->nbr_self->src = oi->address->u.prefix4;
+	oi->nbr_self->state = NSM_TwoWay;
+
+	switch (oi->area->external_routing) {
+	case OSPF_AREA_DEFAULT:
+		SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
+		break;
+	case OSPF_AREA_STUB:
+		UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
+		break;
+	case OSPF_AREA_NSSA:
+		UNSET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
+		SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
+		break;
+	}
+
+	/* Add nbr_self to nbrs table */
+	ospf_nbr_key(oi, oi->nbr_self, &p);
+
+	rn = route_node_get(oi->nbrs, &p);
+	if (rn->info) {
+		/* There is already pseudo neighbor. */
+		if (IS_DEBUG_OSPF_EVENT)
+			zlog_debug(
+				"router_id %pI4 already present in neighbor table. node refcount %u",
+				&router_id, route_node_get_lock_count(rn));
+		route_unlock_node(rn);
+	} else
+		rn->info = oi->nbr_self;
+}
+
+/* Get neighbor count by status.
+   Specify status = 0, get all neighbor other than myself. */
+int ospf_nbr_count(struct ospf_interface *oi, int state)
+{
+	struct ospf_neighbor *nbr;
+	struct route_node *rn;
+	int count = 0;
+
+	for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
+		if ((nbr = rn->info))
+			if (!IPV4_ADDR_SAME(&nbr->router_id,
+					    &oi->ospf->router_id))
+				if (state == 0 || nbr->state == state)
+					count++;
+
+	return count;
+}
+
+int ospf_nbr_count_opaque_capable(struct ospf_interface *oi)
+{
+	struct ospf_neighbor *nbr;
+	struct route_node *rn;
+	int count = 0;
+
+	for (rn = route_top(oi->nbrs); rn; rn = route_next(rn))
+		if ((nbr = rn->info))
+			if (!IPV4_ADDR_SAME(&nbr->router_id,
+					    &oi->ospf->router_id))
+				if (nbr->state == NSM_Full)
+					if (CHECK_FLAG(nbr->options,
+						       OSPF_OPTION_O))
+						count++;
+
+	return count;
+}
+
+/* lookup nbr by address - use this only if you know you must
+ * otherwise use the ospf_nbr_lookup() wrapper, which deals
+ * with virtual link and PointToPoint neighbours
+ */
+struct ospf_neighbor *ospf_nbr_lookup_by_addr(struct route_table *nbrs,
+					      struct in_addr *addr)
+{
+	struct prefix p;
+	struct route_node *rn;
+	struct ospf_neighbor *nbr;
+
+	p.family = AF_INET;
+	p.prefixlen = IPV4_MAX_BITLEN;
+	p.u.prefix4 = *addr;
+
+	rn = route_node_lookup(nbrs, &p);
+	if (!rn)
+		return NULL;
+
+	/* See comment in ospf_nbr_delete */
+	assert(rn->info);
+
+	if (rn->info == NULL) {
+		route_unlock_node(rn);
+		return NULL;
+	}
+
+	nbr = (struct ospf_neighbor *)rn->info;
+	route_unlock_node(rn);
+
+	return nbr;
+}
+
+struct ospf_neighbor *ospf_nbr_lookup_by_routerid(struct route_table *nbrs,
+						  struct in_addr *id)
+{
+	struct route_node *rn;
+	struct ospf_neighbor *nbr;
+
+	for (rn = route_top(nbrs); rn; rn = route_next(rn))
+		if ((nbr = rn->info) != NULL)
+			if (IPV4_ADDR_SAME(&nbr->router_id, id)) {
+				route_unlock_node(rn);
+				return nbr;
+			}
+
+	return NULL;
+}
+
+void ospf_renegotiate_optional_capabilities(struct ospf *top)
+{
+	struct listnode *node;
+	struct ospf_interface *oi;
+	struct route_table *nbrs;
+	struct route_node *rn;
+	struct ospf_neighbor *nbr;
+	uint8_t shutdown_save = top->inst_shutdown;
+
+	/* At first, flush self-originated LSAs from routing domain. */
+	ospf_flush_self_originated_lsas_now(top);
+
+	/* ospf_flush_self_originated_lsas_now is primarily intended for shut
+	 * down scenarios. Reset the inst_shutdown flag that it sets. We are
+	 * just changing configuration, and the flag can change the scheduling
+	 * of when maxage LSAs are sent. */
+	top->inst_shutdown = shutdown_save;
+
+	/* Revert all neighbor status to ExStart. */
+	for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi)) {
+		if ((nbrs = oi->nbrs) == NULL)
+			continue;
+
+		for (rn = route_top(nbrs); rn; rn = route_next(rn)) {
+			if ((nbr = rn->info) == NULL || nbr == oi->nbr_self)
+				continue;
+
+			if (nbr->state < NSM_ExStart)
+				continue;
+
+			if (IS_DEBUG_OSPF_EVENT)
+				zlog_debug(
+					"Renegotiate optional capabilities with neighbor(%pI4)",
+					&nbr->router_id);
+
+			OSPF_NSM_EVENT_SCHEDULE(nbr, NSM_SeqNumberMismatch);
+		}
+	}
+
+	/* Refresh/Re-originate external LSAs (Type-7 and Type-5).*/
+	ospf_external_lsa_rid_change(top);
+
+	return;
+}
+
+
+struct ospf_neighbor *ospf_nbr_lookup(struct ospf_interface *oi, struct ip *iph,
+				      struct ospf_header *ospfh)
+{
+	struct in_addr srcaddr = iph->ip_src;
+
+	if (oi->type == OSPF_IFTYPE_VIRTUALLINK
+	    || oi->type == OSPF_IFTYPE_POINTOPOINT)
+		return (ospf_nbr_lookup_by_routerid(oi->nbrs,
+						    &ospfh->router_id));
+	else
+		return (ospf_nbr_lookup_by_addr(oi->nbrs, &srcaddr));
+}
+
+static struct ospf_neighbor *ospf_nbr_add(struct ospf_interface *oi,
+					  struct ospf_header *ospfh,
+					  struct prefix *p)
+{
+	struct ospf_neighbor *nbr;
+
+	nbr = ospf_nbr_new(oi);
+	nbr->state = NSM_Down;
+	nbr->src = p->u.prefix4;
+	memcpy(&nbr->address, p, sizeof(struct prefix));
+
+	nbr->nbr_nbma = NULL;
+	if (oi->type == OSPF_IFTYPE_NBMA) {
+		struct ospf_nbr_nbma *nbr_nbma;
+		struct listnode *node;
+
+		for (ALL_LIST_ELEMENTS_RO(oi->nbr_nbma, node, nbr_nbma)) {
+			if (IPV4_ADDR_SAME(&nbr_nbma->addr, &nbr->src)) {
+				nbr_nbma->nbr = nbr;
+				nbr->nbr_nbma = nbr_nbma;
+
+				if (nbr_nbma->t_poll)
+					EVENT_OFF(nbr_nbma->t_poll);
+
+				nbr->state_change = nbr_nbma->state_change + 1;
+			}
+		}
+	}
+
+	/* New nbr, save the crypto sequence number if necessary */
+	if (ntohs(ospfh->auth_type) == OSPF_AUTH_CRYPTOGRAPHIC)
+		nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
+
+	/* Configure BFD if interface has it. */
+	ospf_neighbor_bfd_apply(nbr);
+
+	if (IS_DEBUG_OSPF_EVENT)
+		zlog_debug("NSM[%s:%pI4]: start", IF_NAME(oi),
+			   &nbr->router_id);
+
+	return nbr;
+}
+
+struct ospf_neighbor *ospf_nbr_get(struct ospf_interface *oi,
+				   struct ospf_header *ospfh, struct ip *iph,
+				   struct prefix *p)
+{
+	struct route_node *rn;
+	struct prefix key;
+	struct ospf_neighbor *nbr;
+
+	key.family = AF_INET;
+	key.prefixlen = IPV4_MAX_BITLEN;
+
+	if (oi->type == OSPF_IFTYPE_VIRTUALLINK
+	    || oi->type == OSPF_IFTYPE_POINTOPOINT)
+		key.u.prefix4 = ospfh->router_id; /* index vlink and ptp nbrs by
+						     router-id */
+	else
+		key.u.prefix4 = iph->ip_src;
+
+	rn = route_node_get(oi->nbrs, &key);
+	if (rn->info) {
+		route_unlock_node(rn);
+		nbr = rn->info;
+
+		if (oi->type == OSPF_IFTYPE_NBMA && nbr->state == NSM_Attempt) {
+			nbr->src = iph->ip_src;
+			memcpy(&nbr->address, p, sizeof(struct prefix));
+		}
+	} else {
+		rn->info = nbr = ospf_nbr_add(oi, ospfh, p);
+	}
+
+	nbr->router_id = ospfh->router_id;
+
+	return nbr;
+}