1 /* NHRP shortcut related functions
2 * Copyright (c) 2014-2015 Timo Teräs
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.
19 #include "nhrp_protocol.h"
21 DEFINE_MTYPE_STATIC(NHRPD
, NHRP_SHORTCUT
, "NHRP shortcut")
23 static struct route_table
*shortcut_rib
[AFI_MAX
];
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
);
29 static void nhrp_shortcut_check_use(struct nhrp_shortcut
*s
)
31 char buf
[PREFIX_STRLEN
];
33 if (s
->expiring
&& s
->cache
&& s
->cache
->used
) {
34 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s used and expiring",
35 prefix2str(s
->p
, buf
, sizeof buf
));
36 nhrp_shortcut_send_resolution_req(s
);
40 static int nhrp_shortcut_do_expire(struct thread
*t
)
42 struct nhrp_shortcut
*s
= THREAD_ARG(t
);
45 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, s
->holding_time
/ 3,
48 nhrp_shortcut_check_use(s
);
53 static void nhrp_shortcut_cache_notify(struct notifier_block
*n
,
56 struct nhrp_shortcut
*s
=
57 container_of(n
, struct nhrp_shortcut
, cache_notifier
);
61 if (!s
->route_installed
) {
62 nhrp_route_announce(1, s
->type
, s
->p
, NULL
,
63 &s
->cache
->remote_addr
, 0);
64 s
->route_installed
= 1;
67 case NOTIFY_CACHE_USED
:
68 nhrp_shortcut_check_use(s
);
70 case NOTIFY_CACHE_DOWN
:
71 case NOTIFY_CACHE_DELETE
:
72 if (s
->route_installed
) {
73 nhrp_route_announce(0, NHRP_CACHE_INVALID
, s
->p
, NULL
,
75 s
->route_installed
= 0;
77 if (cmd
== NOTIFY_CACHE_DELETE
)
78 nhrp_shortcut_delete(s
);
83 static void nhrp_shortcut_update_binding(struct nhrp_shortcut
*s
,
84 enum nhrp_cache_type type
,
85 struct nhrp_cache
*c
, int holding_time
)
90 nhrp_cache_notify_del(s
->cache
, &s
->cache_notifier
);
95 nhrp_cache_notify_add(s
->cache
, &s
->cache_notifier
,
96 nhrp_shortcut_cache_notify
);
97 if (s
->cache
->route_installed
) {
98 /* Force renewal of Zebra announce on prefix
100 s
->route_installed
= 0;
101 nhrp_shortcut_cache_notify(&s
->cache_notifier
,
105 if (!s
->cache
|| !s
->cache
->route_installed
)
106 nhrp_shortcut_cache_notify(&s
->cache_notifier
,
109 if (s
->type
== NHRP_CACHE_NEGATIVE
&& !s
->route_installed
) {
110 nhrp_route_announce(1, s
->type
, s
->p
, NULL
, NULL
, 0);
111 s
->route_installed
= 1;
112 } else if (s
->type
== NHRP_CACHE_INVALID
&& s
->route_installed
) {
113 nhrp_route_announce(0, NHRP_CACHE_INVALID
, s
->p
, NULL
, NULL
, 0);
114 s
->route_installed
= 0;
117 THREAD_OFF(s
->t_timer
);
120 s
->holding_time
= holding_time
;
121 thread_add_timer(master
, nhrp_shortcut_do_expire
, s
,
122 2 * holding_time
/ 3, &s
->t_timer
);
126 static void nhrp_shortcut_delete(struct nhrp_shortcut
*s
)
128 struct route_node
*rn
;
129 afi_t afi
= family2afi(PREFIX_FAMILY(s
->p
));
130 char buf
[PREFIX_STRLEN
];
132 THREAD_OFF(s
->t_timer
);
133 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
135 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s purged",
136 prefix2str(s
->p
, buf
, sizeof buf
));
138 nhrp_shortcut_update_binding(s
, NHRP_CACHE_INVALID
, NULL
, 0);
141 rn
= route_node_lookup(shortcut_rib
[afi
], s
->p
);
143 XFREE(MTYPE_NHRP_SHORTCUT
, rn
->info
);
145 route_unlock_node(rn
);
146 route_unlock_node(rn
);
150 static int nhrp_shortcut_do_purge(struct thread
*t
)
152 struct nhrp_shortcut
*s
= THREAD_ARG(t
);
154 nhrp_shortcut_delete(s
);
158 static struct nhrp_shortcut
*nhrp_shortcut_get(struct prefix
*p
)
160 struct nhrp_shortcut
*s
;
161 struct route_node
*rn
;
162 char buf
[PREFIX_STRLEN
];
163 afi_t afi
= family2afi(PREFIX_FAMILY(p
));
165 if (!shortcut_rib
[afi
])
168 rn
= route_node_get(shortcut_rib
[afi
], p
);
170 s
= rn
->info
= XCALLOC(MTYPE_NHRP_SHORTCUT
,
171 sizeof(struct nhrp_shortcut
));
172 s
->type
= NHRP_CACHE_INVALID
;
175 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s created",
176 prefix2str(s
->p
, buf
, sizeof buf
));
179 route_unlock_node(rn
);
184 static void nhrp_shortcut_recv_resolution_rep(struct nhrp_reqid
*reqid
,
187 struct nhrp_packet_parser
*pp
= arg
;
188 struct nhrp_shortcut
*s
=
189 container_of(reqid
, struct nhrp_shortcut
, reqid
);
190 struct nhrp_shortcut
*ps
;
191 struct nhrp_extension_header
*ext
;
192 struct nhrp_cie_header
*cie
;
193 struct nhrp_cache
*c
= NULL
;
194 union sockunion
*proto
, cie_proto
, *nbma
, *nbma_natoa
, cie_nbma
,
196 struct prefix prefix
, route_prefix
;
198 char bufp
[PREFIX_STRLEN
], buf
[3][SU_ADDRSTRLEN
];
199 int holding_time
= pp
->if_ad
->holdtime
;
201 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
202 THREAD_OFF(s
->t_timer
);
203 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 1, &s
->t_timer
);
205 if (pp
->hdr
->type
!= NHRP_PACKET_RESOLUTION_REPLY
) {
206 if (pp
->hdr
->type
== NHRP_PACKET_ERROR_INDICATION
207 && pp
->hdr
->u
.error
.code
208 == NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE
) {
209 debugf(NHRP_DEBUG_COMMON
,
210 "Shortcut: Resolution: Protocol address unreachable");
211 nhrp_shortcut_update_binding(s
, NHRP_CACHE_NEGATIVE
,
214 debugf(NHRP_DEBUG_COMMON
,
215 "Shortcut: Resolution failed");
220 /* Parse extensions */
221 memset(&nat_nbma
, 0, sizeof nat_nbma
);
222 while ((ext
= nhrp_ext_pull(&pp
->extensions
, &extpl
)) != NULL
) {
223 switch (htons(ext
->type
) & ~NHRP_EXTENSION_FLAG_COMPULSORY
) {
224 case NHRP_EXTENSION_NAT_ADDRESS
:
225 nhrp_cie_pull(&extpl
, pp
->hdr
, &nat_nbma
, &cie_proto
);
230 /* Minor sanity check */
231 prefix2sockunion(s
->p
, &cie_proto
);
232 if (!sockunion_same(&cie_proto
, &pp
->dst_proto
)) {
233 debugf(NHRP_DEBUG_COMMON
,
234 "Shortcut: Warning dst_proto altered from %s to %s",
235 sockunion2str(&cie_proto
, buf
[0], sizeof buf
[0]),
236 sockunion2str(&pp
->dst_proto
, buf
[1], sizeof buf
[1]));
239 /* One or more CIEs should be given as reply, we support only one */
240 cie
= nhrp_cie_pull(&pp
->payload
, pp
->hdr
, &cie_nbma
, &cie_proto
);
241 if (!cie
|| cie
->code
!= NHRP_CODE_SUCCESS
) {
242 debugf(NHRP_DEBUG_COMMON
, "Shortcut: CIE code %d",
243 cie
? cie
->code
: -1);
247 proto
= sockunion_family(&cie_proto
) != AF_UNSPEC
? &cie_proto
249 if (cie
->holding_time
)
250 holding_time
= htons(cie
->holding_time
);
253 prefix
.prefixlen
= cie
->prefix_length
;
255 /* Sanity check prefix length */
256 if (prefix
.prefixlen
>= 8 * prefix_blen(&prefix
)
257 || prefix
.prefixlen
== 0) {
258 prefix
.prefixlen
= 8 * prefix_blen(&prefix
);
259 } else if (nhrp_route_address(NULL
, &pp
->dst_proto
, &route_prefix
, NULL
)
260 == NHRP_ROUTE_NBMA_NEXTHOP
) {
261 if (prefix
.prefixlen
< route_prefix
.prefixlen
)
262 prefix
.prefixlen
= route_prefix
.prefixlen
;
265 debugf(NHRP_DEBUG_COMMON
,
266 "Shortcut: %s is at proto %s cie-nbma %s nat-nbma %s cie-holdtime %d",
267 prefix2str(&prefix
, bufp
, sizeof bufp
),
268 sockunion2str(proto
, buf
[0], sizeof buf
[0]),
269 sockunion2str(&cie_nbma
, buf
[1], sizeof buf
[1]),
270 sockunion2str(&nat_nbma
, buf
[2], sizeof buf
[2]),
271 htons(cie
->holding_time
));
273 /* Update cache entry for the protocol to nbma binding */
274 if (sockunion_family(&nat_nbma
) != AF_UNSPEC
) {
276 nbma_natoa
= &cie_nbma
;
281 if (sockunion_family(nbma
)) {
282 c
= nhrp_cache_get(pp
->ifp
, proto
, 1);
284 nhrp_cache_update_binding(c
, NHRP_CACHE_CACHED
,
286 nhrp_peer_get(pp
->ifp
, nbma
),
287 htons(cie
->mtu
), nbma_natoa
);
291 /* Update shortcut entry for subnet to protocol gw binding */
292 if (c
&& !sockunion_same(proto
, &pp
->dst_proto
)) {
293 ps
= nhrp_shortcut_get(&prefix
);
296 nhrp_shortcut_update_binding(ps
, NHRP_CACHE_CACHED
, c
,
301 debugf(NHRP_DEBUG_COMMON
, "Shortcut: Resolution reply handled");
304 static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut
*s
)
307 struct nhrp_packet_header
*hdr
;
308 struct interface
*ifp
;
309 struct nhrp_interface
*nifp
;
310 struct nhrp_peer
*peer
;
312 if (nhrp_route_address(NULL
, &s
->addr
, NULL
, &peer
)
313 != NHRP_ROUTE_NBMA_NEXTHOP
)
316 if (s
->type
== NHRP_CACHE_INVALID
|| s
->type
== NHRP_CACHE_NEGATIVE
)
317 s
->type
= NHRP_CACHE_INCOMPLETE
;
323 zb
= zbuf_alloc(1500);
324 hdr
= nhrp_packet_push(
325 zb
, NHRP_PACKET_RESOLUTION_REQUEST
, &nifp
->nbma
,
326 &nifp
->afi
[family2afi(sockunion_family(&s
->addr
))].addr
,
329 htonl(nhrp_reqid_alloc(&nhrp_packet_reqid
, &s
->reqid
,
330 nhrp_shortcut_recv_resolution_rep
));
331 hdr
->flags
= htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER
332 | NHRP_FLAG_RESOLUTION_AUTHORATIVE
333 | NHRP_FLAG_RESOLUTION_SOURCE_STABLE
);
335 /* RFC2332 - One or zero CIEs, if CIE is present contains:
336 * - Prefix length: widest acceptable prefix we accept (if U set, 0xff)
337 * - MTU: MTU of the source station
338 * - Holding Time: Max time to cache the source information
340 /* FIXME: Send holding time, and MTU */
342 nhrp_ext_request(zb
, hdr
, ifp
);
344 /* Cisco NAT detection extension */
345 hdr
->flags
|= htons(NHRP_FLAG_RESOLUTION_NAT
);
346 nhrp_ext_push(zb
, hdr
, NHRP_EXTENSION_NAT_ADDRESS
);
348 nhrp_packet_complete(zb
, hdr
);
350 nhrp_peer_send(peer
, zb
);
351 nhrp_peer_unref(peer
);
355 void nhrp_shortcut_initiate(union sockunion
*addr
)
358 struct nhrp_shortcut
*s
;
360 sockunion2hostprefix(addr
, &p
);
361 s
= nhrp_shortcut_get(&p
);
362 if (s
&& s
->type
!= NHRP_CACHE_INCOMPLETE
) {
364 THREAD_OFF(s
->t_timer
);
365 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 30,
367 nhrp_shortcut_send_resolution_req(s
);
371 void nhrp_shortcut_init(void)
373 shortcut_rib
[AFI_IP
] = route_table_init();
374 shortcut_rib
[AFI_IP6
] = route_table_init();
377 void nhrp_shortcut_terminate(void)
379 route_table_finish(shortcut_rib
[AFI_IP
]);
380 route_table_finish(shortcut_rib
[AFI_IP6
]);
383 void nhrp_shortcut_foreach(afi_t afi
,
384 void (*cb
)(struct nhrp_shortcut
*, void *),
387 struct route_table
*rt
= shortcut_rib
[afi
];
388 struct route_node
*rn
;
389 route_table_iter_t iter
;
394 route_table_iter_init(&iter
, rt
);
395 while ((rn
= route_table_iter_next(&iter
)) != NULL
) {
399 route_table_iter_cleanup(&iter
);
403 const struct prefix
*p
;
407 void nhrp_shortcut_purge(struct nhrp_shortcut
*s
, int force
)
409 THREAD_OFF(s
->t_timer
);
410 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
413 /* Immediate purge on route with draw or pending shortcut */
414 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 5,
417 /* Soft expire - force immediate renewal, but purge
418 * in few seconds to make sure stale route is not
419 * used too long. In practice most purges are caused
420 * by hub bgp change, but target usually stays same.
421 * This allows to keep nhrp route up, and to not
422 * cause temporary rerouting via hubs causing latency
424 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 3000,
427 nhrp_shortcut_check_use(s
);
431 static void nhrp_shortcut_purge_prefix(struct nhrp_shortcut
*s
, void *ctx
)
433 struct purge_ctx
*pctx
= ctx
;
435 if (prefix_match(pctx
->p
, s
->p
))
436 nhrp_shortcut_purge(s
, pctx
->deleted
|| !s
->cache
);
439 void nhrp_shortcut_prefix_change(const struct prefix
*p
, int deleted
)
441 struct purge_ctx pctx
= {
442 .p
= p
, .deleted
= deleted
,
444 nhrp_shortcut_foreach(family2afi(PREFIX_FAMILY(p
)),
445 nhrp_shortcut_purge_prefix
, &pctx
);