path: root/isisd/isis_route.c

/*
 * IS-IS Rout(e)ing protocol               - isis_route.c
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology
 *                           Institute of Communications Engineering
 *
 *                                         based on ../ospf6d/ospf6_route.[ch]
 *                                         by Yasuhiro Ohara
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public Licenseas 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 "thread.h"
#include "linklist.h"
#include "vty.h"
#include "log.h"
#include "memory.h"
#include "prefix.h"
#include "hash.h"
#include "if.h"
#include "table.h"

#include "isis_constants.h"
#include "isis_common.h"
#include "isis_flags.h"
#include "dict.h"
#include "isisd.h"
#include "isis_misc.h"
#include "isis_adjacency.h"
#include "isis_circuit.h"
#include "isis_pdu.h"
#include "isis_lsp.h"
#include "isis_spf.h"
#include "isis_route.h"
#include "isis_zebra.h"

static struct isis_nexthop *isis_nexthop_create(struct in_addr *ip,
						ifindex_t ifindex)
{
	struct listnode *node;
	struct isis_nexthop *nexthop;

	for (ALL_LIST_ELEMENTS_RO(isis->nexthops, node, nexthop)) {
		if (nexthop->ifindex != ifindex)
			continue;
		if (ip && memcmp(&nexthop->ip, ip, sizeof(struct in_addr)) != 0)
			continue;

		nexthop->lock++;
		return nexthop;
	}

	nexthop = XCALLOC(MTYPE_ISIS_NEXTHOP, sizeof(struct isis_nexthop));

	nexthop->ifindex = ifindex;
	memcpy(&nexthop->ip, ip, sizeof(struct in_addr));
	listnode_add(isis->nexthops, nexthop);
	nexthop->lock++;

	return nexthop;
}

static void isis_nexthop_delete(struct isis_nexthop *nexthop)
{
	nexthop->lock--;
	if (nexthop->lock == 0) {
		listnode_delete(isis->nexthops, nexthop);
		XFREE(MTYPE_ISIS_NEXTHOP, nexthop);
	}

	return;
}

static int nexthoplookup(struct list *nexthops, struct in_addr *ip,
			 ifindex_t ifindex)
{
	struct listnode *node;
	struct isis_nexthop *nh;

	for (ALL_LIST_ELEMENTS_RO(nexthops, node, nh)) {
		if (!(memcmp(ip, &nh->ip, sizeof(struct in_addr)))
		    && ifindex == nh->ifindex)
			return 1;
	}

	return 0;
}

#ifdef EXTREME_DEBUG
static void nexthop_print(struct isis_nexthop *nh)
{
	u_char buf[BUFSIZ];

	inet_ntop(AF_INET, &nh->ip, (char *)buf, BUFSIZ);

	zlog_debug("      %s %u", buf, nh->ifindex);
}

static void nexthops_print(struct list *nhs)
{
	struct listnode *node;
	struct isis_nexthop *nh;

	for (ALL_LIST_ELEMENTS_RO(nhs, node, nh))
		nexthop_print(nh);
}
#endif /* EXTREME_DEBUG */

static struct isis_nexthop6 *isis_nexthop6_new(struct in6_addr *ip6,
					       ifindex_t ifindex)
{
	struct isis_nexthop6 *nexthop6;

	nexthop6 = XCALLOC(MTYPE_ISIS_NEXTHOP6, sizeof(struct isis_nexthop6));

	nexthop6->ifindex = ifindex;
	memcpy(&nexthop6->ip6, ip6, sizeof(struct in6_addr));
	nexthop6->lock++;

	return nexthop6;
}

static struct isis_nexthop6 *isis_nexthop6_create(struct in6_addr *ip6,
						  ifindex_t ifindex)
{
	struct listnode *node;
	struct isis_nexthop6 *nexthop6;

	for (ALL_LIST_ELEMENTS_RO(isis->nexthops6, node, nexthop6)) {
		if (nexthop6->ifindex != ifindex)
			continue;
		if (ip6
		    && memcmp(&nexthop6->ip6, ip6, sizeof(struct in6_addr))
			       != 0)
			continue;

		nexthop6->lock++;
		return nexthop6;
	}

	nexthop6 = isis_nexthop6_new(ip6, ifindex);

	return nexthop6;
}

static void isis_nexthop6_delete(struct isis_nexthop6 *nexthop6)
{

	nexthop6->lock--;
	if (nexthop6->lock == 0) {
		listnode_delete(isis->nexthops6, nexthop6);
		XFREE(MTYPE_ISIS_NEXTHOP6, nexthop6);
	}

	return;
}

static int nexthop6lookup(struct list *nexthops6, struct in6_addr *ip6,
			  ifindex_t ifindex)
{
	struct listnode *node;
	struct isis_nexthop6 *nh6;

	for (ALL_LIST_ELEMENTS_RO(nexthops6, node, nh6)) {
		if (!(memcmp(ip6, &nh6->ip6, sizeof(struct in6_addr)))
		    && ifindex == nh6->ifindex)
			return 1;
	}

	return 0;
}

#ifdef EXTREME_DEBUG
static void nexthop6_print(struct isis_nexthop6 *nh6)
{
	u_char buf[BUFSIZ];

	inet_ntop(AF_INET6, &nh6->ip6, (char *)buf, BUFSIZ);

	zlog_debug("      %s %u", buf, nh6->ifindex);
}

static void nexthops6_print(struct list *nhs6)
{
	struct listnode *node;
	struct isis_nexthop6 *nh6;

	for (ALL_LIST_ELEMENTS_RO(nhs6, node, nh6))
		nexthop6_print(nh6);
}
#endif /* EXTREME_DEBUG */

static void adjinfo2nexthop(struct list *nexthops, struct isis_adjacency *adj)
{
	struct isis_nexthop *nh;

	for (unsigned int i = 0; i < adj->ipv4_address_count; i++) {
		struct in_addr *ipv4_addr = &adj->ipv4_addresses[i];
		if (!nexthoplookup(nexthops, ipv4_addr,
				   adj->circuit->interface->ifindex)) {
			nh = isis_nexthop_create(
				ipv4_addr, adj->circuit->interface->ifindex);
			nh->router_address = adj->router_address;
			listnode_add(nexthops, nh);
			return;
		}
	}
}

static void adjinfo2nexthop6(struct list *nexthops6, struct isis_adjacency *adj)
{
	struct isis_nexthop6 *nh6;

	for (unsigned int i = 0; i < adj->ipv6_address_count; i++) {
		struct in6_addr *ipv6_addr = &adj->ipv6_addresses[i];
		if (!nexthop6lookup(nexthops6, ipv6_addr,
				    adj->circuit->interface->ifindex)) {
			nh6 = isis_nexthop6_create(
				ipv6_addr, adj->circuit->interface->ifindex);
			nh6->router_address6 = adj->router_address6;
			listnode_add(nexthops6, nh6);
			return;
		}
	}
}

static struct isis_route_info *isis_route_info_new(struct prefix *prefix,
						   uint32_t cost,
						   uint32_t depth,
						   struct list *adjacencies)
{
	struct isis_route_info *rinfo;
	struct isis_adjacency *adj;
	struct listnode *node;

	rinfo = XCALLOC(MTYPE_ISIS_ROUTE_INFO, sizeof(struct isis_route_info));

	if (prefix->family == AF_INET) {
		rinfo->nexthops = list_new();
		for (ALL_LIST_ELEMENTS_RO(adjacencies, node, adj)) {
			/* check for force resync this route */
			if (CHECK_FLAG(adj->circuit->flags,
				       ISIS_CIRCUIT_FLAPPED_AFTER_SPF))
				SET_FLAG(rinfo->flag,
					 ISIS_ROUTE_FLAG_ZEBRA_RESYNC);
			/* update neighbor router address */
			if (depth == 2 && prefix->prefixlen == 32)
				adj->router_address = prefix->u.prefix4;
			adjinfo2nexthop(rinfo->nexthops, adj);
		}
	}
	if (prefix->family == AF_INET6) {
		rinfo->nexthops6 = list_new();
		for (ALL_LIST_ELEMENTS_RO(adjacencies, node, adj)) {
			/* check for force resync this route */
			if (CHECK_FLAG(adj->circuit->flags,
				       ISIS_CIRCUIT_FLAPPED_AFTER_SPF))
				SET_FLAG(rinfo->flag,
					 ISIS_ROUTE_FLAG_ZEBRA_RESYNC);
			/* update neighbor router address */
			if (depth == 2 && prefix->prefixlen == 128)
				adj->router_address6 = prefix->u.prefix6;
			adjinfo2nexthop6(rinfo->nexthops6, adj);
		}
	}

	rinfo->cost = cost;
	rinfo->depth = depth;

	return rinfo;
}

static void isis_route_info_delete(struct isis_route_info *route_info)
{
	if (route_info->nexthops) {
		route_info->nexthops->del =
			(void (*)(void *))isis_nexthop_delete;
		list_delete(route_info->nexthops);
	}

	if (route_info->nexthops6) {
		route_info->nexthops6->del =
			(void (*)(void *))isis_nexthop6_delete;
		list_delete(route_info->nexthops6);
	}

	XFREE(MTYPE_ISIS_ROUTE_INFO, route_info);
}

static int isis_route_info_same_attrib(struct isis_route_info *new,
				       struct isis_route_info *old)
{
	if (new->cost != old->cost)
		return 0;
	if (new->depth != old->depth)
		return 0;

	return 1;
}

static int isis_route_info_same(struct isis_route_info *new,
				struct isis_route_info *old, u_char family)
{
	struct listnode *node;
	struct isis_nexthop *nexthop;
	struct isis_nexthop6 *nexthop6;

	if (!CHECK_FLAG(old->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED))
		return 0;

	if (CHECK_FLAG(new->flag, ISIS_ROUTE_FLAG_ZEBRA_RESYNC))
		return 0;

	if (!isis_route_info_same_attrib(new, old))
		return 0;

	if (family == AF_INET) {
		for (ALL_LIST_ELEMENTS_RO(new->nexthops, node, nexthop))
			if (nexthoplookup(old->nexthops, &nexthop->ip,
					  nexthop->ifindex)
			    == 0)
				return 0;

		for (ALL_LIST_ELEMENTS_RO(old->nexthops, node, nexthop))
			if (nexthoplookup(new->nexthops, &nexthop->ip,
					  nexthop->ifindex)
			    == 0)
				return 0;
	} else if (family == AF_INET6) {
		for (ALL_LIST_ELEMENTS_RO(new->nexthops6, node, nexthop6))
			if (nexthop6lookup(old->nexthops6, &nexthop6->ip6,
					   nexthop6->ifindex)
			    == 0)
				return 0;

		for (ALL_LIST_ELEMENTS_RO(old->nexthops6, node, nexthop6))
			if (nexthop6lookup(new->nexthops6, &nexthop6->ip6,
					   nexthop6->ifindex)
			    == 0)
				return 0;
	}

	return 1;
}

struct isis_route_info *isis_route_create(struct prefix *prefix, u_int32_t cost,
					  u_int32_t depth,
					  struct list *adjacencies,
					  struct isis_area *area, int level)
{
	struct route_node *route_node;
	struct isis_route_info *rinfo_new, *rinfo_old, *route_info = NULL;
	char buff[PREFIX2STR_BUFFER];
	u_char family;

	family = prefix->family;
	/* for debugs */
	prefix2str(prefix, buff, sizeof(buff));

	rinfo_new = isis_route_info_new(prefix, cost, depth, adjacencies);

	if (family == AF_INET)
		route_node =
			route_node_get(area->route_table[level - 1], prefix);
	else if (family == AF_INET6)
		route_node =
			route_node_get(area->route_table6[level - 1], prefix);
	else {
		isis_route_info_delete(rinfo_new);
		return NULL;
	}

	rinfo_old = route_node->info;
	if (!rinfo_old) {
		if (isis->debugs & DEBUG_RTE_EVENTS)
			zlog_debug("ISIS-Rte (%s) route created: %s",
				   area->area_tag, buff);
		route_info = rinfo_new;
		UNSET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
	} else {
		if (isis->debugs & DEBUG_RTE_EVENTS)
			zlog_debug("ISIS-Rte (%s) route already exists: %s",
				   area->area_tag, buff);
		if (isis_route_info_same(rinfo_new, rinfo_old, family)) {
			if (isis->debugs & DEBUG_RTE_EVENTS)
				zlog_debug("ISIS-Rte (%s) route unchanged: %s",
					   area->area_tag, buff);
			isis_route_info_delete(rinfo_new);
			route_info = rinfo_old;
		} else {
			if (isis->debugs & DEBUG_RTE_EVENTS)
				zlog_debug("ISIS-Rte (%s) route changed: %s",
					   area->area_tag, buff);
			isis_route_info_delete(rinfo_old);
			route_info = rinfo_new;
			UNSET_FLAG(route_info->flag,
				   ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
		}
	}

	SET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ACTIVE);
	route_node->info = route_info;

	return route_info;
}

static void isis_route_delete(struct prefix *prefix, struct route_table *table)
{
	struct route_node *rode;
	struct isis_route_info *rinfo;
	char buff[PREFIX2STR_BUFFER];

	/* for log */
	prefix2str(prefix, buff, sizeof(buff));


	rode = route_node_get(table, prefix);
	rinfo = rode->info;

	if (rinfo == NULL) {
		if (isis->debugs & DEBUG_RTE_EVENTS)
			zlog_debug(
				"ISIS-Rte: tried to delete non-existant route %s",
				buff);
		return;
	}

	if (CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED)) {
		UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
		if (isis->debugs & DEBUG_RTE_EVENTS)
			zlog_debug("ISIS-Rte: route delete  %s", buff);
		isis_zebra_route_update(prefix, rinfo);
	}
	isis_route_info_delete(rinfo);
	rode->info = NULL;

	return;
}

/* Validating routes in particular table. */
static void isis_route_validate_table(struct isis_area *area,
				      struct route_table *table)
{
	struct route_node *rnode, *drnode;
	struct isis_route_info *rinfo;
	char buff[PREFIX2STR_BUFFER];

	for (rnode = route_top(table); rnode; rnode = route_next(rnode)) {
		if (rnode->info == NULL)
			continue;
		rinfo = rnode->info;

		if (isis->debugs & DEBUG_RTE_EVENTS) {
			prefix2str(&rnode->p, buff, sizeof(buff));
			zlog_debug(
				"ISIS-Rte (%s): route validate: %s %s %s %s",
				area->area_tag,
				(CHECK_FLAG(rinfo->flag,
					    ISIS_ROUTE_FLAG_ZEBRA_SYNCED)
					 ? "synced"
					 : "not-synced"),
				(CHECK_FLAG(rinfo->flag,
					    ISIS_ROUTE_FLAG_ZEBRA_RESYNC)
					 ? "resync"
					 : "not-resync"),
				(CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE)
					 ? "active"
					 : "inactive"),
				buff);
		}

		isis_zebra_route_update(&rnode->p, rinfo);
		if (!CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE)) {
			/* Area is either L1 or L2 => we use level route tables
			 * directly for
			 * validating => no problems with deleting routes. */
			if (area->is_type != IS_LEVEL_1_AND_2) {
				isis_route_delete(&rnode->p, table);
				continue;
			}
			/* If area is L1L2, we work with merge table and
			 * therefore must
			 * delete node from level tables as well before deleting
			 * route info.
			 * FIXME: Is it performance problem? There has to be the
			 * better way.
			 * Like not to deal with it here at all (see the next
			 * comment)? */
			if (rnode->p.family == AF_INET) {
				drnode = route_node_get(area->route_table[0],
							&rnode->p);
				if (drnode->info == rnode->info)
					drnode->info = NULL;
				drnode = route_node_get(area->route_table[1],
							&rnode->p);
				if (drnode->info == rnode->info)
					drnode->info = NULL;
			}

			if (rnode->p.family == AF_INET6) {
				drnode = route_node_get(area->route_table6[0],
							&rnode->p);
				if (drnode->info == rnode->info)
					drnode->info = NULL;
				drnode = route_node_get(area->route_table6[1],
							&rnode->p);
				if (drnode->info == rnode->info)
					drnode->info = NULL;
			}

			isis_route_delete(&rnode->p, table);
		}
	}
}

/* Function to validate route tables for L1L2 areas. In this case we can't use
 * level route tables directly, we have to merge them at first. L1 routes are
 * preferred over the L2 ones.
 *
 * Merge algorithm is trivial (at least for now). All L1 paths are copied into
 * merge table at first, then L2 paths are added if L1 path for same prefix
 * doesn't already exists there.
 *
 * FIXME: Is it right place to do it at all? Maybe we should push both levels
 * to the RIB with different zebra route types and let RIB handle this? */
static void isis_route_validate_merge(struct isis_area *area, int family)
{
	struct route_table *table = NULL;
	struct route_table *merge;
	struct route_node *rnode, *mrnode;

	merge = route_table_init();

	if (family == AF_INET)
		table = area->route_table[0];
	else if (family == AF_INET6)
		table = area->route_table6[0];
	else {
		zlog_warn("ISIS-Rte (%s) %s called for unknown family %d",
			  area->area_tag, __func__, family);
		route_table_finish(merge);
		return;
	}

	for (rnode = route_top(table); rnode; rnode = route_next(rnode)) {
		if (rnode->info == NULL)
			continue;
		mrnode = route_node_get(merge, &rnode->p);
		mrnode->info = rnode->info;
	}

	if (family == AF_INET)
		table = area->route_table[1];
	else if (family == AF_INET6)
		table = area->route_table6[1];

	for (rnode = route_top(table); rnode; rnode = route_next(rnode)) {
		if (rnode->info == NULL)
			continue;
		mrnode = route_node_get(merge, &rnode->p);
		if (mrnode->info != NULL)
			continue;
		mrnode->info = rnode->info;
	}

	isis_route_validate_table(area, merge);
	route_table_finish(merge);
}

/* Walk through route tables and propagate necessary changes into RIB. In case
 * of L1L2 area, level tables have to be merged at first. */
void isis_route_validate(struct isis_area *area)
{
	struct listnode *node;
	struct isis_circuit *circuit;

	if (area->is_type == IS_LEVEL_1)
		isis_route_validate_table(area, area->route_table[0]);
	else if (area->is_type == IS_LEVEL_2)
		isis_route_validate_table(area, area->route_table[1]);
	else
		isis_route_validate_merge(area, AF_INET);

	if (area->is_type == IS_LEVEL_1)
		isis_route_validate_table(area, area->route_table6[0]);
	else if (area->is_type == IS_LEVEL_2)
		isis_route_validate_table(area, area->route_table6[1]);
	else
		isis_route_validate_merge(area, AF_INET6);

	if (!area->circuit_list) {
		return;
	}
	/* walk all circuits and reset any spf specific flags */
	for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit))
		UNSET_FLAG(circuit->flags, ISIS_CIRCUIT_FLAPPED_AFTER_SPF);

	return;
}

void isis_route_invalidate_table(struct isis_area *area,
				 struct route_table *table)
{
	struct route_node *rode;
	struct isis_route_info *rinfo;
	for (rode = route_top(table); rode; rode = route_next(rode)) {
		if (rode->info == NULL)
			continue;
		rinfo = rode->info;

		UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
	}
}

void isis_route_invalidate(struct isis_area *area)
{
	if (area->is_type & IS_LEVEL_1)
		isis_route_invalidate_table(area, area->route_table[0]);
	if (area->is_type & IS_LEVEL_2)
		isis_route_invalidate_table(area, area->route_table[1]);
}