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
);
144 route_unlock_node(rn
);
145 route_unlock_node(rn
);
149 static int nhrp_shortcut_do_purge(struct thread
*t
)
151 struct nhrp_shortcut
*s
= THREAD_ARG(t
);
153 nhrp_shortcut_delete(s
);
157 static struct nhrp_shortcut
*nhrp_shortcut_get(struct prefix
*p
)
159 struct nhrp_shortcut
*s
;
160 struct route_node
*rn
;
161 char buf
[PREFIX_STRLEN
];
162 afi_t afi
= family2afi(PREFIX_FAMILY(p
));
164 if (!shortcut_rib
[afi
])
167 rn
= route_node_get(shortcut_rib
[afi
], p
);
169 s
= rn
->info
= XCALLOC(MTYPE_NHRP_SHORTCUT
,
170 sizeof(struct nhrp_shortcut
));
171 s
->type
= NHRP_CACHE_INVALID
;
174 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s created",
175 prefix2str(s
->p
, buf
, sizeof buf
));
178 route_unlock_node(rn
);
183 static void nhrp_shortcut_recv_resolution_rep(struct nhrp_reqid
*reqid
,
186 struct nhrp_packet_parser
*pp
= arg
;
187 struct nhrp_shortcut
*s
=
188 container_of(reqid
, struct nhrp_shortcut
, reqid
);
189 struct nhrp_shortcut
*ps
;
190 struct nhrp_extension_header
*ext
;
191 struct nhrp_cie_header
*cie
;
192 struct nhrp_cache
*c
= NULL
;
193 union sockunion
*proto
, cie_proto
, *nbma
, *nbma_natoa
, cie_nbma
,
195 struct prefix prefix
, route_prefix
;
197 char bufp
[PREFIX_STRLEN
], buf
[3][SU_ADDRSTRLEN
];
198 int holding_time
= pp
->if_ad
->holdtime
;
200 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
201 THREAD_OFF(s
->t_timer
);
202 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 1, &s
->t_timer
);
204 if (pp
->hdr
->type
!= NHRP_PACKET_RESOLUTION_REPLY
) {
205 if (pp
->hdr
->type
== NHRP_PACKET_ERROR_INDICATION
206 && pp
->hdr
->u
.error
.code
207 == NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE
) {
208 debugf(NHRP_DEBUG_COMMON
,
209 "Shortcut: Resolution: Protocol address unreachable");
210 nhrp_shortcut_update_binding(s
, NHRP_CACHE_NEGATIVE
,
213 debugf(NHRP_DEBUG_COMMON
,
214 "Shortcut: Resolution failed");
219 /* Parse extensions */
220 memset(&nat_nbma
, 0, sizeof nat_nbma
);
221 while ((ext
= nhrp_ext_pull(&pp
->extensions
, &extpl
)) != NULL
) {
222 switch (htons(ext
->type
) & ~NHRP_EXTENSION_FLAG_COMPULSORY
) {
223 case NHRP_EXTENSION_NAT_ADDRESS
:
224 nhrp_cie_pull(&extpl
, pp
->hdr
, &nat_nbma
, &cie_proto
);
229 /* Minor sanity check */
230 prefix2sockunion(s
->p
, &cie_proto
);
231 if (!sockunion_same(&cie_proto
, &pp
->dst_proto
)) {
232 debugf(NHRP_DEBUG_COMMON
,
233 "Shortcut: Warning dst_proto altered from %s to %s",
234 sockunion2str(&cie_proto
, buf
[0], sizeof buf
[0]),
235 sockunion2str(&pp
->dst_proto
, buf
[1], sizeof buf
[1]));
238 /* One or more CIEs should be given as reply, we support only one */
239 cie
= nhrp_cie_pull(&pp
->payload
, pp
->hdr
, &cie_nbma
, &cie_proto
);
240 if (!cie
|| cie
->code
!= NHRP_CODE_SUCCESS
) {
241 debugf(NHRP_DEBUG_COMMON
, "Shortcut: CIE code %d",
242 cie
? cie
->code
: -1);
246 proto
= sockunion_family(&cie_proto
) != AF_UNSPEC
? &cie_proto
248 if (cie
->holding_time
)
249 holding_time
= htons(cie
->holding_time
);
252 prefix
.prefixlen
= cie
->prefix_length
;
254 /* Sanity check prefix length */
255 if (prefix
.prefixlen
>= 8 * prefix_blen(&prefix
)
256 || prefix
.prefixlen
== 0) {
257 prefix
.prefixlen
= 8 * prefix_blen(&prefix
);
258 } else if (nhrp_route_address(NULL
, &pp
->dst_proto
, &route_prefix
, NULL
)
259 == NHRP_ROUTE_NBMA_NEXTHOP
) {
260 if (prefix
.prefixlen
< route_prefix
.prefixlen
)
261 prefix
.prefixlen
= route_prefix
.prefixlen
;
264 debugf(NHRP_DEBUG_COMMON
,
265 "Shortcut: %s is at proto %s cie-nbma %s nat-nbma %s cie-holdtime %d",
266 prefix2str(&prefix
, bufp
, sizeof bufp
),
267 sockunion2str(proto
, buf
[0], sizeof buf
[0]),
268 sockunion2str(&cie_nbma
, buf
[1], sizeof buf
[1]),
269 sockunion2str(&nat_nbma
, buf
[2], sizeof buf
[2]),
270 htons(cie
->holding_time
));
272 /* Update cache entry for the protocol to nbma binding */
273 if (sockunion_family(&nat_nbma
) != AF_UNSPEC
) {
275 nbma_natoa
= &cie_nbma
;
280 if (sockunion_family(nbma
)) {
281 c
= nhrp_cache_get(pp
->ifp
, proto
, 1);
283 nhrp_cache_update_binding(c
, NHRP_CACHE_CACHED
,
285 nhrp_peer_get(pp
->ifp
, nbma
),
286 htons(cie
->mtu
), nbma_natoa
);
290 /* Update shortcut entry for subnet to protocol gw binding */
291 if (c
&& !sockunion_same(proto
, &pp
->dst_proto
)) {
292 ps
= nhrp_shortcut_get(&prefix
);
295 nhrp_shortcut_update_binding(ps
, NHRP_CACHE_CACHED
, c
,
300 debugf(NHRP_DEBUG_COMMON
, "Shortcut: Resolution reply handled");
303 static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut
*s
)
306 struct nhrp_packet_header
*hdr
;
307 struct interface
*ifp
;
308 struct nhrp_interface
*nifp
;
309 struct nhrp_peer
*peer
;
311 if (nhrp_route_address(NULL
, &s
->addr
, NULL
, &peer
)
312 != NHRP_ROUTE_NBMA_NEXTHOP
)
315 if (s
->type
== NHRP_CACHE_INVALID
|| s
->type
== NHRP_CACHE_NEGATIVE
)
316 s
->type
= NHRP_CACHE_INCOMPLETE
;
322 zb
= zbuf_alloc(1500);
323 hdr
= nhrp_packet_push(
324 zb
, NHRP_PACKET_RESOLUTION_REQUEST
, &nifp
->nbma
,
325 &nifp
->afi
[family2afi(sockunion_family(&s
->addr
))].addr
,
328 htonl(nhrp_reqid_alloc(&nhrp_packet_reqid
, &s
->reqid
,
329 nhrp_shortcut_recv_resolution_rep
));
330 hdr
->flags
= htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER
331 | NHRP_FLAG_RESOLUTION_AUTHORATIVE
332 | NHRP_FLAG_RESOLUTION_SOURCE_STABLE
);
334 /* RFC2332 - One or zero CIEs, if CIE is present contains:
335 * - Prefix length: widest acceptable prefix we accept (if U set, 0xff)
336 * - MTU: MTU of the source station
337 * - Holding Time: Max time to cache the source information
339 /* FIXME: Send holding time, and MTU */
341 nhrp_ext_request(zb
, hdr
, ifp
);
343 /* Cisco NAT detection extension */
344 hdr
->flags
|= htons(NHRP_FLAG_RESOLUTION_NAT
);
345 nhrp_ext_push(zb
, hdr
, NHRP_EXTENSION_NAT_ADDRESS
);
347 nhrp_packet_complete(zb
, hdr
);
349 nhrp_peer_send(peer
, zb
);
350 nhrp_peer_unref(peer
);
354 void nhrp_shortcut_initiate(union sockunion
*addr
)
357 struct nhrp_shortcut
*s
;
359 sockunion2hostprefix(addr
, &p
);
360 s
= nhrp_shortcut_get(&p
);
361 if (s
&& s
->type
!= NHRP_CACHE_INCOMPLETE
) {
363 THREAD_OFF(s
->t_timer
);
364 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 30,
366 nhrp_shortcut_send_resolution_req(s
);
370 void nhrp_shortcut_init(void)
372 shortcut_rib
[AFI_IP
] = route_table_init();
373 shortcut_rib
[AFI_IP6
] = route_table_init();
376 void nhrp_shortcut_terminate(void)
378 route_table_finish(shortcut_rib
[AFI_IP
]);
379 route_table_finish(shortcut_rib
[AFI_IP6
]);
382 void nhrp_shortcut_foreach(afi_t afi
,
383 void (*cb
)(struct nhrp_shortcut
*, void *),
386 struct route_table
*rt
= shortcut_rib
[afi
];
387 struct route_node
*rn
;
388 route_table_iter_t iter
;
393 route_table_iter_init(&iter
, rt
);
394 while ((rn
= route_table_iter_next(&iter
)) != NULL
) {
398 route_table_iter_cleanup(&iter
);
402 const struct prefix
*p
;
406 void nhrp_shortcut_purge(struct nhrp_shortcut
*s
, int force
)
408 THREAD_OFF(s
->t_timer
);
409 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
412 /* Immediate purge on route with draw or pending shortcut */
413 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 5,
416 /* Soft expire - force immediate renewal, but purge
417 * in few seconds to make sure stale route is not
418 * used too long. In practice most purges are caused
419 * by hub bgp change, but target usually stays same.
420 * This allows to keep nhrp route up, and to not
421 * cause temporary rerouting via hubs causing latency
423 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 3000,
426 nhrp_shortcut_check_use(s
);
430 static void nhrp_shortcut_purge_prefix(struct nhrp_shortcut
*s
, void *ctx
)
432 struct purge_ctx
*pctx
= ctx
;
434 if (prefix_match(pctx
->p
, s
->p
))
435 nhrp_shortcut_purge(s
, pctx
->deleted
|| !s
->cache
);
438 void nhrp_shortcut_prefix_change(const struct prefix
*p
, int deleted
)
440 struct purge_ctx pctx
= {
441 .p
= p
, .deleted
= deleted
,
443 nhrp_shortcut_foreach(family2afi(PREFIX_FAMILY(p
)),
444 nhrp_shortcut_purge_prefix
, &pctx
);