[mirror_frr.git] / nhrpd / nhrp_shortcut.c

/* NHRP shortcut related functions
 * Copyright (c) 2014-2015 Timo Teräs
 *
 * This file is free software: you may copy, redistribute 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "nhrpd.h"
#include "table.h"
#include "memory.h"
#include "thread.h"
#include "log.h"
#include "nhrp_protocol.h"

DEFINE_MTYPE_STATIC(NHRPD, NHRP_SHORTCUT, "NHRP shortcut")

static struct route_table *shortcut_rib[AFI_MAX];

static int nhrp_shortcut_do_purge(struct thread *t);
static void nhrp_shortcut_delete(struct nhrp_shortcut *s);
static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut *s);

static void nhrp_shortcut_check_use(struct nhrp_shortcut *s)
{
	if (s->expiring && s->cache && s->cache->used) {
		debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX used and expiring",
		       s->p);
		nhrp_shortcut_send_resolution_req(s);
	}
}

static int nhrp_shortcut_do_expire(struct thread *t)
{
	struct nhrp_shortcut *s = THREAD_ARG(t);

	s->t_timer = NULL;
	thread_add_timer(master, nhrp_shortcut_do_purge, s, s->holding_time / 3,
			 &s->t_timer);
	s->expiring = 1;
	nhrp_shortcut_check_use(s);

	return 0;
}

static void nhrp_shortcut_cache_notify(struct notifier_block *n,
				       unsigned long cmd)
{
	char buf2[PREFIX_STRLEN];

	struct nhrp_shortcut *s =
		container_of(n, struct nhrp_shortcut, cache_notifier);
	struct nhrp_cache *c = s->cache;

	if (c)
		sockunion2str(&c->remote_addr, buf2, sizeof(buf2));
	else
		snprintf(buf2, sizeof(buf2), "(unspec)");
	switch (cmd) {
	case NOTIFY_CACHE_UP:
		if (!s->route_installed) {
			debugf(NHRP_DEBUG_ROUTE,
			       "Shortcut: route install %pFX nh %s dev %s",
			       s->p, buf2, c && c->ifp ?
			       c->ifp->name : "<unk>");

			nhrp_route_announce(1, s->type, s->p, c ? c->ifp : NULL,
					    c ? &c->remote_addr : NULL, 0);
			s->route_installed = 1;
		}
		break;
	case NOTIFY_CACHE_USED:
		nhrp_shortcut_check_use(s);
		break;
	case NOTIFY_CACHE_DOWN:
	case NOTIFY_CACHE_DELETE:
		if (s->route_installed) {
			nhrp_route_announce(0, NHRP_CACHE_INVALID, s->p, NULL,
					    NULL, 0);
			s->route_installed = 0;
		}
		if (cmd == NOTIFY_CACHE_DELETE)
			nhrp_shortcut_delete(s);
		break;
	}
}

static void nhrp_shortcut_update_binding(struct nhrp_shortcut *s,
					 enum nhrp_cache_type type,
					 struct nhrp_cache *c, int holding_time)
{
	s->type = type;
	if (c != s->cache) {
		if (s->cache) {
			nhrp_cache_notify_del(s->cache, &s->cache_notifier);
			s->cache = NULL;
		}
		s->cache = c;
		if (s->cache) {
			nhrp_cache_notify_add(s->cache, &s->cache_notifier,
					      nhrp_shortcut_cache_notify);
			if (s->cache->route_installed) {
				/* Force renewal of Zebra announce on prefix
				 * change */
				s->route_installed = 0;
				debugf(NHRP_DEBUG_ROUTE,
				       "Shortcut: forcing renewal of zebra announce on prefix change peer %pSU ht %u cur nbma %pSU dev %s",
				       &s->cache->remote_addr, holding_time,
				       &s->cache->cur.remote_nbma_natoa,
				       s->cache->ifp->name);
				nhrp_shortcut_cache_notify(&s->cache_notifier,
							   NOTIFY_CACHE_UP);
			}
		}
		if (!s->cache || !s->cache->route_installed) {
			debugf(NHRP_DEBUG_ROUTE,
			       "Shortcut: notify cache down because cache?%s or ri?%s",
			       s->cache ? "yes" : "no",
			       s->cache ? (s->cache->route_installed ? "yes"
								     : "no")
					: "n/a");
			nhrp_shortcut_cache_notify(&s->cache_notifier,
						   NOTIFY_CACHE_DOWN);
		}
	}
	if (s->type == NHRP_CACHE_NEGATIVE && !s->route_installed) {
		nhrp_route_announce(1, s->type, s->p, NULL, NULL, 0);
		s->route_installed = 1;
	} else if (s->type == NHRP_CACHE_INVALID && s->route_installed) {
		nhrp_route_announce(0, NHRP_CACHE_INVALID, s->p, NULL, NULL, 0);
		s->route_installed = 0;
	}

	THREAD_OFF(s->t_timer);
	if (holding_time) {
		s->expiring = 0;
		s->holding_time = holding_time;
		thread_add_timer(master, nhrp_shortcut_do_expire, s,
				 2 * holding_time / 3, &s->t_timer);
	}
}

static void nhrp_shortcut_delete(struct nhrp_shortcut *s)
{
	struct route_node *rn;
	afi_t afi = family2afi(PREFIX_FAMILY(s->p));

	THREAD_OFF(s->t_timer);
	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);

	debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX purged", s->p);

	nhrp_shortcut_update_binding(s, NHRP_CACHE_INVALID, NULL, 0);

	/* Delete node */
	rn = route_node_lookup(shortcut_rib[afi], s->p);
	if (rn) {
		XFREE(MTYPE_NHRP_SHORTCUT, rn->info);
		rn->info = NULL;
		route_unlock_node(rn);
		route_unlock_node(rn);
	}
}

static int nhrp_shortcut_do_purge(struct thread *t)
{
	struct nhrp_shortcut *s = THREAD_ARG(t);
	s->t_timer = NULL;
	nhrp_shortcut_delete(s);
	return 0;
}

static struct nhrp_shortcut *nhrp_shortcut_get(struct prefix *p)
{
	struct nhrp_shortcut *s;
	struct route_node *rn;
	afi_t afi = family2afi(PREFIX_FAMILY(p));

	if (!shortcut_rib[afi])
		return 0;

	rn = route_node_get(shortcut_rib[afi], p);
	if (!rn->info) {
		s = rn->info = XCALLOC(MTYPE_NHRP_SHORTCUT,
				       sizeof(struct nhrp_shortcut));
		s->type = NHRP_CACHE_INVALID;
		s->p = &rn->p;

		debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX created", s->p);
	} else {
		s = rn->info;
		route_unlock_node(rn);
	}
	return s;
}

static void nhrp_shortcut_recv_resolution_rep(struct nhrp_reqid *reqid,
					      void *arg)
{
	struct nhrp_packet_parser *pp = arg;
	struct interface *ifp = pp->ifp;
	struct nhrp_interface *nifp = ifp->info;
	struct nhrp_shortcut *s =
		container_of(reqid, struct nhrp_shortcut, reqid);
	struct nhrp_shortcut *ps;
	struct nhrp_extension_header *ext;
	struct nhrp_cie_header *cie;
	struct nhrp_cache *c = NULL;
	struct nhrp_cache *c_dst = NULL;
	union sockunion *proto, cie_proto, *nbma, cie_nbma, nat_nbma;
	struct prefix prefix, route_prefix;
	struct zbuf extpl;
	char buf[4][SU_ADDRSTRLEN];
	int holding_time = pp->if_ad->holdtime;

	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);
	THREAD_OFF(s->t_timer);
	thread_add_timer(master, nhrp_shortcut_do_purge, s, 1, &s->t_timer);

	if (pp->hdr->type != NHRP_PACKET_RESOLUTION_REPLY) {
		if (pp->hdr->type == NHRP_PACKET_ERROR_INDICATION
		    && pp->hdr->u.error.code
			       == NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE) {
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: Resolution: Protocol address unreachable");
			nhrp_shortcut_update_binding(s, NHRP_CACHE_NEGATIVE,
						     NULL, holding_time);
		} else {
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: Resolution failed");
		}
		return;
	}

	/* Minor sanity check */
	prefix2sockunion(s->p, &cie_proto);
	if (!sockunion_same(&cie_proto, &pp->dst_proto)) {
		debugf(NHRP_DEBUG_COMMON,
		       "Shortcut: Warning dst_proto altered from %pSU to %pSU",
		       &cie_proto, &pp->dst_proto);
		;
	}

	/* One or more CIEs should be given as reply, we support only one */
	cie = nhrp_cie_pull(&pp->payload, pp->hdr, &cie_nbma, &cie_proto);
	if (!cie || cie->code != NHRP_CODE_SUCCESS) {
		debugf(NHRP_DEBUG_COMMON, "Shortcut: CIE code %d",
		       cie ? cie->code : -1);
		return;
	}

	proto = sockunion_family(&cie_proto) != AF_UNSPEC ? &cie_proto
							  : &pp->dst_proto;
	if (cie->holding_time)
		holding_time = htons(cie->holding_time);

	prefix = *s->p;
	prefix.prefixlen = cie->prefix_length;

	/* Sanity check prefix length */
	if (prefix.prefixlen >= 8 * prefix_blen(&prefix)
	    || prefix.prefixlen == 0) {
		prefix.prefixlen = 8 * prefix_blen(&prefix);
	} else if (nhrp_route_address(NULL, &pp->dst_proto, &route_prefix, NULL)
		   == NHRP_ROUTE_NBMA_NEXTHOP) {
		if (prefix.prefixlen < route_prefix.prefixlen)
			prefix.prefixlen = route_prefix.prefixlen;
	}

	/* Parse extensions */
	memset(&nat_nbma, 0, sizeof(nat_nbma));
	while ((ext = nhrp_ext_pull(&pp->extensions, &extpl)) != NULL) {
		switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
		case NHRP_EXTENSION_NAT_ADDRESS: {
			struct nhrp_cie_header *cie_nat;

			do {
				union sockunion cie_nat_proto, cie_nat_nbma;

				sockunion_family(&cie_nat_proto) = AF_UNSPEC;
				sockunion_family(&cie_nat_nbma) = AF_UNSPEC;
				cie_nat = nhrp_cie_pull(&extpl, pp->hdr,
							&cie_nat_nbma,
							&cie_nat_proto);
				/* We are interested only in peer CIE */
				if (cie_nat
				    && sockunion_same(&cie_nat_proto, proto)) {
					nat_nbma = cie_nat_nbma;
				}
			} while (cie_nat);
		} break;
		default:
			break;
		}
	}

	/* Update cache entry for the protocol to nbma binding */
	if (sockunion_family(&nat_nbma) != AF_UNSPEC) {
		debugf(NHRP_DEBUG_COMMON,
		       "Remote Device is NATTED, NHRP NAT Extension present");
		debugf(NHRP_DEBUG_COMMON,
		       "Client NBMA Address %s",
		       sockunion2str(&nat_nbma, buf[1], sizeof(buf[1])));
		nbma = &nat_nbma;
	}
	/* For NHRP resolution reply the cie_nbma in mandatory part is the
	 * address of the actual address of the sender
	 */
	else if (!sockunion_same(&cie_nbma, &pp->peer->vc->remote.nbma)
		 && !nhrp_nhs_match_ip(&pp->peer->vc->remote.nbma, nifp)) {
		debugf(NHRP_DEBUG_COMMON,
		       "Remote Device is NATTED, NHRP NAT Extension not present for proto %s",
		       sockunion2str(proto, buf[0], sizeof(buf[0])));
		debugf(NHRP_DEBUG_COMMON, "cie_nbma %s",
		       sockunion2str(&cie_nbma, buf[1], sizeof(buf[1])));
		debugf(NHRP_DEBUG_COMMON, "remote.nbma %s",
		       sockunion2str(&pp->peer->vc->remote.nbma, buf[1],
				sizeof(buf[1])));
		nbma = &pp->peer->vc->remote.nbma;
		nat_nbma = *nbma;
	} else {
		nbma = &cie_nbma;
	}

	debugf(NHRP_DEBUG_COMMON,
	       "Shortcut: %pFX is at proto %pSU dst_proto %pSU cie-nbma %pSU nat-nbma %pSU cie-holdtime %d",
	       &prefix, proto, &pp->dst_proto, &cie_nbma, &nat_nbma,
	       htons(cie->holding_time));


	if (sockunion_family(nbma)) {
		c = nhrp_cache_get(pp->ifp, proto, 1);
		if (c) {
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: cache found, update binding");
			nhrp_cache_update_binding(c, NHRP_CACHE_DYNAMIC,
						  holding_time,
						  nhrp_peer_get(pp->ifp, nbma),
						  htons(cie->mtu),
						  nbma,
						  &cie_nbma);
		} else {
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: no cache for nbma %s", buf[2]);
		}

		/* Update cache binding for dst_proto as well */
		if (sockunion_cmp(proto, &pp->dst_proto)) {
			c_dst = nhrp_cache_get(pp->ifp, &pp->dst_proto, 1);
			if (c_dst) {
				debugf(NHRP_DEBUG_COMMON,
				       "Shortcut: cache found, update binding");
				nhrp_cache_update_binding(c_dst,
						  NHRP_CACHE_DYNAMIC,
						  holding_time,
						  nhrp_peer_get(pp->ifp, nbma),
						  htons(cie->mtu),
						  nbma,
						  &cie_nbma);
			} else {
				debugf(NHRP_DEBUG_COMMON,
				       "Shortcut: no cache for nbma %s",
				       buf[2]);
			}
		}
	}

	/* Update shortcut entry for subnet to protocol gw binding */
	if (c) {
		ps = nhrp_shortcut_get(&prefix);
		if (ps) {
			ps->addr = s->addr;
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: calling update_binding");
			nhrp_shortcut_update_binding(ps, NHRP_CACHE_DYNAMIC, c,
						     holding_time);
		} else {
			debugf(NHRP_DEBUG_COMMON,
			       "Shortcut: proto diff but no ps");
		}
	} else {
		debugf(NHRP_DEBUG_COMMON,
		       "NO Shortcut because c NULL?%s or same proto?%s",
		       c ? "no" : "yes",
		       proto && pp && sockunion_same(proto, &pp->dst_proto)
			       ? "yes"
			       : "no");
	}

	debugf(NHRP_DEBUG_COMMON, "Shortcut: Resolution reply handled");
}

static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut *s)
{
	struct zbuf *zb;
	struct nhrp_packet_header *hdr;
	struct interface *ifp;
	struct nhrp_interface *nifp;
	struct nhrp_afi_data *if_ad;
	struct nhrp_peer *peer;
	struct nhrp_cie_header *cie;
	struct nhrp_extension_header *ext;

	if (nhrp_route_address(NULL, &s->addr, NULL, &peer)
	    != NHRP_ROUTE_NBMA_NEXTHOP)
		return;

	if (s->type == NHRP_CACHE_INVALID || s->type == NHRP_CACHE_NEGATIVE)
		s->type = NHRP_CACHE_INCOMPLETE;

	ifp = peer->ifp;
	nifp = ifp->info;

	/* Create request */
	zb = zbuf_alloc(1500);
	hdr = nhrp_packet_push(
		zb, NHRP_PACKET_RESOLUTION_REQUEST, &nifp->nbma,
		&nifp->afi[family2afi(sockunion_family(&s->addr))].addr,
		&s->addr);
	hdr->u.request_id =
		htonl(nhrp_reqid_alloc(&nhrp_packet_reqid, &s->reqid,
				       nhrp_shortcut_recv_resolution_rep));
	hdr->flags = htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER
			   | NHRP_FLAG_RESOLUTION_AUTHORATIVE
			   | NHRP_FLAG_RESOLUTION_SOURCE_STABLE);

	/* RFC2332 - One or zero CIEs, if CIE is present contains:
	 *  - Prefix length: widest acceptable prefix we accept (if U set, 0xff)
	 *  - MTU: MTU of the source station
	 *  - Holding Time: Max time to cache the source information
	 * */
	/* FIXME: push CIE for each local protocol address */
	cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, NULL, NULL);
	cie->prefix_length = 0xff;
	if_ad = &nifp->afi[family2afi(sockunion_family(&s->addr))];
	cie->holding_time = htons(if_ad->holdtime);
	cie->mtu = htons(if_ad->mtu);
	debugf(NHRP_DEBUG_COMMON,
	       "Shortcut res_req: set cie ht to %u and mtu to %u. shortcut ht is %u",
	       ntohs(cie->holding_time), ntohs(cie->mtu), s->holding_time);

	nhrp_ext_request(zb, hdr, ifp);

	/* Cisco NAT detection extension */
	hdr->flags |= htons(NHRP_FLAG_RESOLUTION_NAT);
	ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
	if (sockunion_family(&nifp->nat_nbma) != AF_UNSPEC) {
		cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nat_nbma,
				    &if_ad->addr);
		cie->prefix_length = 8 * sockunion_get_addrlen(&if_ad->addr);
		cie->mtu = htons(if_ad->mtu);
		nhrp_ext_complete(zb, ext);
	}

	nhrp_packet_complete(zb, hdr);

	nhrp_peer_send(peer, zb);
	nhrp_peer_unref(peer);
	zbuf_free(zb);
}

void nhrp_shortcut_initiate(union sockunion *addr)
{
	struct prefix p;
	struct nhrp_shortcut *s;

	if (!sockunion2hostprefix(addr, &p))
		return;

	s = nhrp_shortcut_get(&p);
	if (s && s->type != NHRP_CACHE_INCOMPLETE) {
		s->addr = *addr;
		THREAD_OFF(s->t_timer);
		thread_add_timer(master, nhrp_shortcut_do_purge, s, 30,
				 &s->t_timer);
		nhrp_shortcut_send_resolution_req(s);
	}
}

void nhrp_shortcut_init(void)
{
	shortcut_rib[AFI_IP] = route_table_init();
	shortcut_rib[AFI_IP6] = route_table_init();
}

void nhrp_shortcut_terminate(void)
{
	route_table_finish(shortcut_rib[AFI_IP]);
	route_table_finish(shortcut_rib[AFI_IP6]);
}

void nhrp_shortcut_foreach(afi_t afi,
			   void (*cb)(struct nhrp_shortcut *, void *),
			   void *ctx)
{
	struct route_table *rt = shortcut_rib[afi];
	struct route_node *rn;
	route_table_iter_t iter;

	if (!rt)
		return;

	route_table_iter_init(&iter, rt);
	while ((rn = route_table_iter_next(&iter)) != NULL) {
		if (rn->info)
			cb(rn->info, ctx);
	}
	route_table_iter_cleanup(&iter);
}

struct purge_ctx {
	const struct prefix *p;
	int deleted;
};

void nhrp_shortcut_purge(struct nhrp_shortcut *s, int force)
{
	THREAD_OFF(s->t_timer);
	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);

	if (force) {
		/* Immediate purge on route with draw or pending shortcut */
		thread_add_timer_msec(master, nhrp_shortcut_do_purge, s, 5,
				      &s->t_timer);
	} else {
		/* Soft expire - force immediate renewal, but purge
		 * in few seconds to make sure stale route is not
		 * used too long. In practice most purges are caused
		 * by hub bgp change, but target usually stays same.
		 * This allows to keep nhrp route up, and to not
		 * cause temporary rerouting via hubs causing latency
		 * jitter. */
		thread_add_timer_msec(master, nhrp_shortcut_do_purge, s, 3000,
				      &s->t_timer);
		s->expiring = 1;
		nhrp_shortcut_check_use(s);
	}
}

static void nhrp_shortcut_purge_prefix(struct nhrp_shortcut *s, void *ctx)
{
	struct purge_ctx *pctx = ctx;

	if (prefix_match(pctx->p, s->p))
		nhrp_shortcut_purge(s, pctx->deleted || !s->cache);
}

void nhrp_shortcut_prefix_change(const struct prefix *p, int deleted)
{
	struct purge_ctx pctx = {
		.p = p, .deleted = deleted,
	};
	nhrp_shortcut_foreach(family2afi(PREFIX_FAMILY(p)),
			      nhrp_shortcut_purge_prefix, &pctx);
}
Commit	Line	Data
2fb975da TT	1	/* NHRP shortcut related functions
	2	* Copyright (c) 2014-2015 Timo Teräs
	3	*
	4	* This file is free software: you may copy, redistribute and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation, either version 2 of the License, or
	7	* (at your option) any later version.
	8	*/
	9
b45ac5f5 DL	10	#ifdef HAVE_CONFIG_H
	11	#include "config.h"
	12	#endif
	13
2fb975da TT	14	#include "nhrpd.h"
	15	#include "table.h"
	16	#include "memory.h"
	17	#include "thread.h"
	18	#include "log.h"
	19	#include "nhrp_protocol.h"
	20
819dc8bb DL	21	DEFINE_MTYPE_STATIC(NHRPD, NHRP_SHORTCUT, "NHRP shortcut")
819dc8bb DL	22
2fb975da TT	23	static struct route_table *shortcut_rib[AFI_MAX];
	24
	25	static int nhrp_shortcut_do_purge(struct thread *t);
	26	static void nhrp_shortcut_delete(struct nhrp_shortcut *s);
	27	static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut *s);
	28
	29	static void nhrp_shortcut_check_use(struct nhrp_shortcut *s)
	30	{
2fb975da	31	if (s->expiring && s->cache && s->cache->used) {
2dbe669b DA	32	debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX used and expiring",
2dbe669b DA	33	s->p);
2fb975da TT	34	nhrp_shortcut_send_resolution_req(s);
	35	}
	36	}
	37
	38	static int nhrp_shortcut_do_expire(struct thread *t)
	39	{
	40	struct nhrp_shortcut *s = THREAD_ARG(t);
	41
	42	s->t_timer = NULL;
996c9314 LB	43	thread_add_timer(master, nhrp_shortcut_do_purge, s, s->holding_time / 3,
996c9314 LB	44	&s->t_timer);
2fb975da TT	45	s->expiring = 1;
	46	nhrp_shortcut_check_use(s);
	47
	48	return 0;
	49	}
	50
996c9314 LB	51	static void nhrp_shortcut_cache_notify(struct notifier_block *n,
996c9314 LB	52	unsigned long cmd)
2fb975da	53	{
ef91ff04 PG	54	char buf2[PREFIX_STRLEN];
ef91ff04 PG	55
996c9314 LB	56	struct nhrp_shortcut *s =
996c9314 LB	57	container_of(n, struct nhrp_shortcut, cache_notifier);
ef91ff04	58	struct nhrp_cache *c = s->cache;
2fb975da	59
ef91ff04 PG	60	if (c)
	61	sockunion2str(&c->remote_addr, buf2, sizeof(buf2));
	62	else
	63	snprintf(buf2, sizeof(buf2), "(unspec)");
2fb975da TT	64	switch (cmd) {
	65	case NOTIFY_CACHE_UP:
	66	if (!s->route_installed) {
912c556b	67	debugf(NHRP_DEBUG_ROUTE,
ef91ff04 PG	68	"Shortcut: route install %pFX nh %s dev %s",
	69	s->p, buf2, c && c->ifp ?
	70	c->ifp->name : "<unk>");
912c556b	71
ef91ff04 PG	72	nhrp_route_announce(1, s->type, s->p, c ? c->ifp : NULL,
ef91ff04 PG	73	c ? &c->remote_addr : NULL, 0);
2fb975da TT	74	s->route_installed = 1;
	75	}
	76	break;
	77	case NOTIFY_CACHE_USED:
	78	nhrp_shortcut_check_use(s);
	79	break;
	80	case NOTIFY_CACHE_DOWN:
	81	case NOTIFY_CACHE_DELETE:
	82	if (s->route_installed) {
996c9314 LB	83	nhrp_route_announce(0, NHRP_CACHE_INVALID, s->p, NULL,
996c9314 LB	84	NULL, 0);
2fb975da TT	85	s->route_installed = 0;
	86	}
	87	if (cmd == NOTIFY_CACHE_DELETE)
	88	nhrp_shortcut_delete(s);
	89	break;
	90	}
	91	}
	92
996c9314 LB	93	static void nhrp_shortcut_update_binding(struct nhrp_shortcut *s,
	94	enum nhrp_cache_type type,
	95	struct nhrp_cache *c, int holding_time)
2fb975da TT	96	{
	97	s->type = type;
	98	if (c != s->cache) {
	99	if (s->cache) {
	100	nhrp_cache_notify_del(s->cache, &s->cache_notifier);
	101	s->cache = NULL;
	102	}
	103	s->cache = c;
	104	if (s->cache) {
996c9314 LB	105	nhrp_cache_notify_add(s->cache, &s->cache_notifier,
996c9314 LB	106	nhrp_shortcut_cache_notify);
2fb975da	107	if (s->cache->route_installed) {
996c9314 LB	108	/* Force renewal of Zebra announce on prefix
996c9314 LB	109	* change */
2fb975da	110	s->route_installed = 0;
912c556b	111	debugf(NHRP_DEBUG_ROUTE,
b6c48481 DS	112	"Shortcut: forcing renewal of zebra announce on prefix change peer %pSU ht %u cur nbma %pSU dev %s",
	113	&s->cache->remote_addr, holding_time,
	114	&s->cache->cur.remote_nbma_natoa,
912c556b	115	s->cache->ifp->name);
996c9314 LB	116	nhrp_shortcut_cache_notify(&s->cache_notifier,
996c9314 LB	117	NOTIFY_CACHE_UP);
2fb975da TT	118	}
2fb975da TT	119	}
912c556b GN	120	if (!s->cache \|\| !s->cache->route_installed) {
912c556b GN	121	debugf(NHRP_DEBUG_ROUTE,
5f36c26c	122	"Shortcut: notify cache down because cache?%s or ri?%s",
912c556b GN	123	s->cache ? "yes" : "no",
	124	s->cache ? (s->cache->route_installed ? "yes"
	125	: "no")
	126	: "n/a");
996c9314 LB	127	nhrp_shortcut_cache_notify(&s->cache_notifier,
996c9314 LB	128	NOTIFY_CACHE_DOWN);
912c556b	129	}
2fb975da TT	130	}
	131	if (s->type == NHRP_CACHE_NEGATIVE && !s->route_installed) {
	132	nhrp_route_announce(1, s->type, s->p, NULL, NULL, 0);
	133	s->route_installed = 1;
	134	} else if (s->type == NHRP_CACHE_INVALID && s->route_installed) {
	135	nhrp_route_announce(0, NHRP_CACHE_INVALID, s->p, NULL, NULL, 0);
	136	s->route_installed = 0;
	137	}
	138
	139	THREAD_OFF(s->t_timer);
	140	if (holding_time) {
	141	s->expiring = 0;
	142	s->holding_time = holding_time;
ffa2c898 QY	143	thread_add_timer(master, nhrp_shortcut_do_expire, s,
ffa2c898 QY	144	2 * holding_time / 3, &s->t_timer);
2fb975da TT	145	}
	146	}
	147
	148	static void nhrp_shortcut_delete(struct nhrp_shortcut *s)
	149	{
	150	struct route_node *rn;
	151	afi_t afi = family2afi(PREFIX_FAMILY(s->p));
2fb975da TT	152
	153	THREAD_OFF(s->t_timer);
	154	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);
	155
2dbe669b	156	debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX purged", s->p);
2fb975da TT	157
	158	nhrp_shortcut_update_binding(s, NHRP_CACHE_INVALID, NULL, 0);
	159
	160	/* Delete node */
	161	rn = route_node_lookup(shortcut_rib[afi], s->p);
	162	if (rn) {
	163	XFREE(MTYPE_NHRP_SHORTCUT, rn->info);
912c556b	164	rn->info = NULL;
2fb975da TT	165	route_unlock_node(rn);
	166	route_unlock_node(rn);
	167	}
	168	}
	169
	170	static int nhrp_shortcut_do_purge(struct thread *t)
	171	{
	172	struct nhrp_shortcut *s = THREAD_ARG(t);
	173	s->t_timer = NULL;
	174	nhrp_shortcut_delete(s);
	175	return 0;
	176	}
	177
	178	static struct nhrp_shortcut nhrp_shortcut_get(struct prefix p)
	179	{
	180	struct nhrp_shortcut *s;
	181	struct route_node *rn;
2fb975da TT	182	afi_t afi = family2afi(PREFIX_FAMILY(p));
	183
	184	if (!shortcut_rib[afi])
	185	return 0;
	186
	187	rn = route_node_get(shortcut_rib[afi], p);
	188	if (!rn->info) {
996c9314 LB	189	s = rn->info = XCALLOC(MTYPE_NHRP_SHORTCUT,
996c9314 LB	190	sizeof(struct nhrp_shortcut));
2fb975da TT	191	s->type = NHRP_CACHE_INVALID;
	192	s->p = &rn->p;
	193
2dbe669b	194	debugf(NHRP_DEBUG_ROUTE, "Shortcut %pFX created", s->p);
2fb975da TT	195	} else {
	196	s = rn->info;
	197	route_unlock_node(rn);
	198	}
	199	return s;
	200	}
	201
996c9314 LB	202	static void nhrp_shortcut_recv_resolution_rep(struct nhrp_reqid *reqid,
996c9314 LB	203	void *arg)
2fb975da TT	204	{
2fb975da TT	205	struct nhrp_packet_parser *pp = arg;
bb58f442 GG	206	struct interface *ifp = pp->ifp;
bb58f442 GG	207	struct nhrp_interface *nifp = ifp->info;
996c9314 LB	208	struct nhrp_shortcut *s =
996c9314 LB	209	container_of(reqid, struct nhrp_shortcut, reqid);
2fb975da TT	210	struct nhrp_shortcut *ps;
	211	struct nhrp_extension_header *ext;
	212	struct nhrp_cie_header *cie;
	213	struct nhrp_cache *c = NULL;
00683a14	214	struct nhrp_cache *c_dst = NULL;
9c292647	215	union sockunion proto, cie_proto, nbma, cie_nbma, nat_nbma;
2fb975da TT	216	struct prefix prefix, route_prefix;
2fb975da TT	217	struct zbuf extpl;
2dbe669b	218	char buf[4][SU_ADDRSTRLEN];
2fb975da TT	219	int holding_time = pp->if_ad->holdtime;
	220
	221	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);
	222	THREAD_OFF(s->t_timer);
ffa2c898	223	thread_add_timer(master, nhrp_shortcut_do_purge, s, 1, &s->t_timer);
2fb975da TT	224
2fb975da TT	225	if (pp->hdr->type != NHRP_PACKET_RESOLUTION_REPLY) {
996c9314 LB	226	if (pp->hdr->type == NHRP_PACKET_ERROR_INDICATION
	227	&& pp->hdr->u.error.code
	228	== NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE) {
	229	debugf(NHRP_DEBUG_COMMON,
	230	"Shortcut: Resolution: Protocol address unreachable");
	231	nhrp_shortcut_update_binding(s, NHRP_CACHE_NEGATIVE,
	232	NULL, holding_time);
2fb975da	233	} else {
996c9314 LB	234	debugf(NHRP_DEBUG_COMMON,
996c9314 LB	235	"Shortcut: Resolution failed");
2fb975da TT	236	}
	237	return;
	238	}
	239
2fb975da TT	240	/* Minor sanity check */
	241	prefix2sockunion(s->p, &cie_proto);
	242	if (!sockunion_same(&cie_proto, &pp->dst_proto)) {
996c9314	243	debugf(NHRP_DEBUG_COMMON,
b6c48481 DS	244	"Shortcut: Warning dst_proto altered from %pSU to %pSU",
	245	&cie_proto, &pp->dst_proto);
	246	;
2fb975da TT	247	}
	248
	249	/* One or more CIEs should be given as reply, we support only one */
	250	cie = nhrp_cie_pull(&pp->payload, pp->hdr, &cie_nbma, &cie_proto);
	251	if (!cie \|\| cie->code != NHRP_CODE_SUCCESS) {
996c9314 LB	252	debugf(NHRP_DEBUG_COMMON, "Shortcut: CIE code %d",
996c9314 LB	253	cie ? cie->code : -1);
2fb975da TT	254	return;
	255	}
	256
996c9314 LB	257	proto = sockunion_family(&cie_proto) != AF_UNSPEC ? &cie_proto
996c9314 LB	258	: &pp->dst_proto;
2fb975da TT	259	if (cie->holding_time)
	260	holding_time = htons(cie->holding_time);
	261
	262	prefix = *s->p;
	263	prefix.prefixlen = cie->prefix_length;
	264
	265	/* Sanity check prefix length */
996c9314 LB	266	if (prefix.prefixlen >= 8 * prefix_blen(&prefix)
	267	\|\| prefix.prefixlen == 0) {
	268	prefix.prefixlen = 8 * prefix_blen(&prefix);
	269	} else if (nhrp_route_address(NULL, &pp->dst_proto, &route_prefix, NULL)
	270	== NHRP_ROUTE_NBMA_NEXTHOP) {
2fb975da TT	271	if (prefix.prefixlen < route_prefix.prefixlen)
	272	prefix.prefixlen = route_prefix.prefixlen;
	273	}
	274
9c292647 AL	275	/* Parse extensions */
	276	memset(&nat_nbma, 0, sizeof(nat_nbma));
	277	while ((ext = nhrp_ext_pull(&pp->extensions, &extpl)) != NULL) {
	278	switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
	279	case NHRP_EXTENSION_NAT_ADDRESS: {
	280	struct nhrp_cie_header *cie_nat;
00683a14	281
9c292647 AL	282	do {
9c292647 AL	283	union sockunion cie_nat_proto, cie_nat_nbma;
00683a14	284
9c292647 AL	285	sockunion_family(&cie_nat_proto) = AF_UNSPEC;
9c292647 AL	286	sockunion_family(&cie_nat_nbma) = AF_UNSPEC;
611915ae AL	287	cie_nat = nhrp_cie_pull(&extpl, pp->hdr,
	288	&cie_nat_nbma,
	289	&cie_nat_proto);
9c292647	290	/* We are interested only in peer CIE */
611915ae AL	291	if (cie_nat
611915ae AL	292	&& sockunion_same(&cie_nat_proto, proto)) {
9c292647 AL	293	nat_nbma = cie_nat_nbma;
	294	}
	295	} while (cie_nat);
	296	} break;
	297	default:
	298	break;
	299	}
	300	}
	301
bb58f442 GG	302	/* Update cache entry for the protocol to nbma binding */
bb58f442 GG	303	if (sockunion_family(&nat_nbma) != AF_UNSPEC) {
611915ae AL	304	debugf(NHRP_DEBUG_COMMON,
	305	"Remote Device is NATTED, NHRP NAT Extension present");
	306	debugf(NHRP_DEBUG_COMMON,
	307	"Client NBMA Address %s",
	308	sockunion2str(&nat_nbma, buf[1], sizeof(buf[1])));
9c292647	309	nbma = &nat_nbma;
611915ae AL	310	}
611915ae AL	311	/* For NHRP resolution reply the cie_nbma in mandatory part is the
00683a14 RD	312	* address of the actual address of the sender
00683a14 RD	313	*/
611915ae AL	314	else if (!sockunion_same(&cie_nbma, &pp->peer->vc->remote.nbma)
	315	&& !nhrp_nhs_match_ip(&pp->peer->vc->remote.nbma, nifp)) {
	316	debugf(NHRP_DEBUG_COMMON,
	317	"Remote Device is NATTED, NHRP NAT Extension not present for proto %s",
	318	sockunion2str(proto, buf[0], sizeof(buf[0])));
	319	debugf(NHRP_DEBUG_COMMON, "cie_nbma %s",
	320	sockunion2str(&cie_nbma, buf[1], sizeof(buf[1])));
	321	debugf(NHRP_DEBUG_COMMON, "remote.nbma %s",
00683a14	322	sockunion2str(&pp->peer->vc->remote.nbma, buf[1],
611915ae	323	sizeof(buf[1])));
bb58f442 GG	324	nbma = &pp->peer->vc->remote.nbma;
	325	nat_nbma = *nbma;
	326	} else {
	327	nbma = &cie_nbma;
	328	}
	329
996c9314	330	debugf(NHRP_DEBUG_COMMON,
b6c48481 DS	331	"Shortcut: %pFX is at proto %pSU dst_proto %pSU cie-nbma %pSU nat-nbma %pSU cie-holdtime %d",
b6c48481 DS	332	&prefix, proto, &pp->dst_proto, &cie_nbma, &nat_nbma,
996c9314	333	htons(cie->holding_time));
2fb975da	334
912c556b	335
2fb975da TT	336	if (sockunion_family(nbma)) {
	337	c = nhrp_cache_get(pp->ifp, proto, 1);
	338	if (c) {
912c556b GN	339	debugf(NHRP_DEBUG_COMMON,
	340	"Shortcut: cache found, update binding");
	341	nhrp_cache_update_binding(c, NHRP_CACHE_DYNAMIC,
996c9314 LB	342	holding_time,
996c9314 LB	343	nhrp_peer_get(pp->ifp, nbma),
00683a14 RD	344	htons(cie->mtu),
	345	nbma,
	346	&cie_nbma);
912c556b GN	347	} else {
	348	debugf(NHRP_DEBUG_COMMON,
	349	"Shortcut: no cache for nbma %s", buf[2]);
2fb975da	350	}
ac95bcef GG	351
ac95bcef GG	352	/* Update cache binding for dst_proto as well */
bb58f442	353	if (sockunion_cmp(proto, &pp->dst_proto)) {
00683a14 RD	354	c_dst = nhrp_cache_get(pp->ifp, &pp->dst_proto, 1);
00683a14 RD	355	if (c_dst) {
ac95bcef	356	debugf(NHRP_DEBUG_COMMON,
00683a14 RD	357	"Shortcut: cache found, update binding");
	358	nhrp_cache_update_binding(c_dst,
	359	NHRP_CACHE_DYNAMIC,
ac95bcef GG	360	holding_time,
ac95bcef GG	361	nhrp_peer_get(pp->ifp, nbma),
00683a14 RD	362	htons(cie->mtu),
	363	nbma,
	364	&cie_nbma);
ac95bcef GG	365	} else {
ac95bcef GG	366	debugf(NHRP_DEBUG_COMMON,
00683a14 RD	367	"Shortcut: no cache for nbma %s",
00683a14 RD	368	buf[2]);
ac95bcef GG	369	}
ac95bcef GG	370	}
2fb975da TT	371	}
	372
	373	/* Update shortcut entry for subnet to protocol gw binding */
912c556b	374	if (c) {
2fb975da TT	375	ps = nhrp_shortcut_get(&prefix);
	376	if (ps) {
	377	ps->addr = s->addr;
912c556b	378	debugf(NHRP_DEBUG_COMMON,
5f36c26c	379	"Shortcut: calling update_binding");
912c556b	380	nhrp_shortcut_update_binding(ps, NHRP_CACHE_DYNAMIC, c,
996c9314	381	holding_time);
912c556b GN	382	} else {
	383	debugf(NHRP_DEBUG_COMMON,
	384	"Shortcut: proto diff but no ps");
2fb975da	385	}
912c556b GN	386	} else {
912c556b GN	387	debugf(NHRP_DEBUG_COMMON,
5f36c26c	388	"NO Shortcut because c NULL?%s or same proto?%s",
912c556b GN	389	c ? "no" : "yes",
	390	proto && pp && sockunion_same(proto, &pp->dst_proto)
	391	? "yes"
	392	: "no");
2fb975da TT	393	}
	394
	395	debugf(NHRP_DEBUG_COMMON, "Shortcut: Resolution reply handled");
	396	}
	397
	398	static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut *s)
	399	{
	400	struct zbuf *zb;
	401	struct nhrp_packet_header *hdr;
	402	struct interface *ifp;
	403	struct nhrp_interface *nifp;
47d40757	404	struct nhrp_afi_data *if_ad;
2fb975da	405	struct nhrp_peer *peer;
47d40757	406	struct nhrp_cie_header *cie;
c2cffffb	407	struct nhrp_extension_header *ext;
2fb975da	408
996c9314 LB	409	if (nhrp_route_address(NULL, &s->addr, NULL, &peer)
996c9314 LB	410	!= NHRP_ROUTE_NBMA_NEXTHOP)
2fb975da TT	411	return;
	412
	413	if (s->type == NHRP_CACHE_INVALID \|\| s->type == NHRP_CACHE_NEGATIVE)
	414	s->type = NHRP_CACHE_INCOMPLETE;
	415
	416	ifp = peer->ifp;
	417	nifp = ifp->info;
	418
	419	/* Create request */
	420	zb = zbuf_alloc(1500);
996c9314 LB	421	hdr = nhrp_packet_push(
	422	zb, NHRP_PACKET_RESOLUTION_REQUEST, &nifp->nbma,
	423	&nifp->afi[family2afi(sockunion_family(&s->addr))].addr,
	424	&s->addr);
	425	hdr->u.request_id =
	426	htonl(nhrp_reqid_alloc(&nhrp_packet_reqid, &s->reqid,
	427	nhrp_shortcut_recv_resolution_rep));
	428	hdr->flags = htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER
	429	\| NHRP_FLAG_RESOLUTION_AUTHORATIVE
	430	\| NHRP_FLAG_RESOLUTION_SOURCE_STABLE);
2fb975da TT	431
	432	/* RFC2332 - One or zero CIEs, if CIE is present contains:
	433	* - Prefix length: widest acceptable prefix we accept (if U set, 0xff)
	434	* - MTU: MTU of the source station
	435	* - Holding Time: Max time to cache the source information
	436	* */
47d40757 GN	437	/* FIXME: push CIE for each local protocol address */
	438	cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, NULL, NULL);
	439	cie->prefix_length = 0xff;
	440	if_ad = &nifp->afi[family2afi(sockunion_family(&s->addr))];
	441	cie->holding_time = htons(if_ad->holdtime);
	442	cie->mtu = htons(if_ad->mtu);
	443	debugf(NHRP_DEBUG_COMMON,
5f36c26c	444	"Shortcut res_req: set cie ht to %u and mtu to %u. shortcut ht is %u",
47d40757	445	ntohs(cie->holding_time), ntohs(cie->mtu), s->holding_time);
2fb975da TT	446
	447	nhrp_ext_request(zb, hdr, ifp);
	448
	449	/* Cisco NAT detection extension */
	450	hdr->flags \|= htons(NHRP_FLAG_RESOLUTION_NAT);
c2cffffb	451	ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
611915ae AL	452	if (sockunion_family(&nifp->nat_nbma) != AF_UNSPEC) {
	453	cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &nifp->nat_nbma,
	454	&if_ad->addr);
999a07f0	455	cie->prefix_length = 8 * sockunion_get_addrlen(&if_ad->addr);
1e52c954	456	cie->mtu = htons(if_ad->mtu);
c2cffffb GG	457	nhrp_ext_complete(zb, ext);
c2cffffb GG	458	}
2fb975da TT	459
	460	nhrp_packet_complete(zb, hdr);
	461
	462	nhrp_peer_send(peer, zb);
	463	nhrp_peer_unref(peer);
	464	zbuf_free(zb);
	465	}
	466
	467	void nhrp_shortcut_initiate(union sockunion *addr)
	468	{
	469	struct prefix p;
	470	struct nhrp_shortcut *s;
	471
0154d8ce DS	472	if (!sockunion2hostprefix(addr, &p))
	473	return;
	474
2fb975da TT	475	s = nhrp_shortcut_get(&p);
	476	if (s && s->type != NHRP_CACHE_INCOMPLETE) {
	477	s->addr = *addr;
	478	THREAD_OFF(s->t_timer);
ffa2c898 QY	479	thread_add_timer(master, nhrp_shortcut_do_purge, s, 30,
ffa2c898 QY	480	&s->t_timer);
2fb975da TT	481	nhrp_shortcut_send_resolution_req(s);
	482	}
	483	}
	484
	485	void nhrp_shortcut_init(void)
	486	{
	487	shortcut_rib[AFI_IP] = route_table_init();
	488	shortcut_rib[AFI_IP6] = route_table_init();
	489	}
	490
	491	void nhrp_shortcut_terminate(void)
	492	{
	493	route_table_finish(shortcut_rib[AFI_IP]);
	494	route_table_finish(shortcut_rib[AFI_IP6]);
	495	}
	496
996c9314 LB	497	void nhrp_shortcut_foreach(afi_t afi,
	498	void (cb)(struct nhrp_shortcut , void *),
	499	void *ctx)
2fb975da TT	500	{
	501	struct route_table *rt = shortcut_rib[afi];
	502	struct route_node *rn;
	503	route_table_iter_t iter;
	504
996c9314 LB	505	if (!rt)
996c9314 LB	506	return;
2fb975da TT	507
	508	route_table_iter_init(&iter, rt);
	509	while ((rn = route_table_iter_next(&iter)) != NULL) {
996c9314 LB	510	if (rn->info)
996c9314 LB	511	cb(rn->info, ctx);
2fb975da TT	512	}
	513	route_table_iter_cleanup(&iter);
	514	}
	515
	516	struct purge_ctx {
	517	const struct prefix *p;
	518	int deleted;
	519	};
	520
	521	void nhrp_shortcut_purge(struct nhrp_shortcut *s, int force)
	522	{
	523	THREAD_OFF(s->t_timer);
	524	nhrp_reqid_free(&nhrp_packet_reqid, &s->reqid);
	525
	526	if (force) {
	527	/* Immediate purge on route with draw or pending shortcut */
ffa2c898 QY	528	thread_add_timer_msec(master, nhrp_shortcut_do_purge, s, 5,
ffa2c898 QY	529	&s->t_timer);
2fb975da TT	530	} else {
	531	/* Soft expire - force immediate renewal, but purge
	532	* in few seconds to make sure stale route is not
	533	* used too long. In practice most purges are caused
	534	* by hub bgp change, but target usually stays same.
	535	* This allows to keep nhrp route up, and to not
	536	* cause temporary rerouting via hubs causing latency
	537	* jitter. */
ffa2c898 QY	538	thread_add_timer_msec(master, nhrp_shortcut_do_purge, s, 3000,
ffa2c898 QY	539	&s->t_timer);
2fb975da TT	540	s->expiring = 1;
	541	nhrp_shortcut_check_use(s);
	542	}
	543	}
	544
	545	static void nhrp_shortcut_purge_prefix(struct nhrp_shortcut s, void ctx)
	546	{
	547	struct purge_ctx *pctx = ctx;
	548
	549	if (prefix_match(pctx->p, s->p))
	550	nhrp_shortcut_purge(s, pctx->deleted \|\| !s->cache);
	551	}
	552
	553	void nhrp_shortcut_prefix_change(const struct prefix *p, int deleted)
	554	{
	555	struct purge_ctx pctx = {
996c9314	556	.p = p, .deleted = deleted,
2fb975da	557	};
996c9314 LB	558	nhrp_shortcut_foreach(family2afi(PREFIX_FAMILY(p)),
996c9314 LB	559	nhrp_shortcut_purge_prefix, &pctx);
2fb975da	560	}