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.
15 #include "nhrp_protocol.h"
17 DEFINE_MTYPE_STATIC(NHRPD
, NHRP_SHORTCUT
, "NHRP shortcut")
19 static struct route_table
*shortcut_rib
[AFI_MAX
];
21 static int nhrp_shortcut_do_purge(struct thread
*t
);
22 static void nhrp_shortcut_delete(struct nhrp_shortcut
*s
);
23 static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut
*s
);
25 static void nhrp_shortcut_check_use(struct nhrp_shortcut
*s
)
27 char buf
[PREFIX_STRLEN
];
29 if (s
->expiring
&& s
->cache
&& s
->cache
->used
) {
30 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s used and expiring",
31 prefix2str(s
->p
, buf
, sizeof buf
));
32 nhrp_shortcut_send_resolution_req(s
);
36 static int nhrp_shortcut_do_expire(struct thread
*t
)
38 struct nhrp_shortcut
*s
= THREAD_ARG(t
);
41 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, s
->holding_time
/ 3,
44 nhrp_shortcut_check_use(s
);
49 static void nhrp_shortcut_cache_notify(struct notifier_block
*n
,
52 struct nhrp_shortcut
*s
=
53 container_of(n
, struct nhrp_shortcut
, cache_notifier
);
57 if (!s
->route_installed
) {
58 nhrp_route_announce(1, s
->type
, s
->p
, NULL
,
59 &s
->cache
->remote_addr
, 0);
60 s
->route_installed
= 1;
63 case NOTIFY_CACHE_USED
:
64 nhrp_shortcut_check_use(s
);
66 case NOTIFY_CACHE_DOWN
:
67 case NOTIFY_CACHE_DELETE
:
68 if (s
->route_installed
) {
69 nhrp_route_announce(0, NHRP_CACHE_INVALID
, s
->p
, NULL
,
71 s
->route_installed
= 0;
73 if (cmd
== NOTIFY_CACHE_DELETE
)
74 nhrp_shortcut_delete(s
);
79 static void nhrp_shortcut_update_binding(struct nhrp_shortcut
*s
,
80 enum nhrp_cache_type type
,
81 struct nhrp_cache
*c
, int holding_time
)
86 nhrp_cache_notify_del(s
->cache
, &s
->cache_notifier
);
91 nhrp_cache_notify_add(s
->cache
, &s
->cache_notifier
,
92 nhrp_shortcut_cache_notify
);
93 if (s
->cache
->route_installed
) {
94 /* Force renewal of Zebra announce on prefix
96 s
->route_installed
= 0;
97 nhrp_shortcut_cache_notify(&s
->cache_notifier
,
101 if (!s
->cache
|| !s
->cache
->route_installed
)
102 nhrp_shortcut_cache_notify(&s
->cache_notifier
,
105 if (s
->type
== NHRP_CACHE_NEGATIVE
&& !s
->route_installed
) {
106 nhrp_route_announce(1, s
->type
, s
->p
, NULL
, NULL
, 0);
107 s
->route_installed
= 1;
108 } else if (s
->type
== NHRP_CACHE_INVALID
&& s
->route_installed
) {
109 nhrp_route_announce(0, NHRP_CACHE_INVALID
, s
->p
, NULL
, NULL
, 0);
110 s
->route_installed
= 0;
113 THREAD_OFF(s
->t_timer
);
116 s
->holding_time
= holding_time
;
117 thread_add_timer(master
, nhrp_shortcut_do_expire
, s
,
118 2 * holding_time
/ 3, &s
->t_timer
);
122 static void nhrp_shortcut_delete(struct nhrp_shortcut
*s
)
124 struct route_node
*rn
;
125 afi_t afi
= family2afi(PREFIX_FAMILY(s
->p
));
126 char buf
[PREFIX_STRLEN
];
128 THREAD_OFF(s
->t_timer
);
129 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
131 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s purged",
132 prefix2str(s
->p
, buf
, sizeof buf
));
134 nhrp_shortcut_update_binding(s
, NHRP_CACHE_INVALID
, NULL
, 0);
137 rn
= route_node_lookup(shortcut_rib
[afi
], s
->p
);
139 XFREE(MTYPE_NHRP_SHORTCUT
, rn
->info
);
141 route_unlock_node(rn
);
142 route_unlock_node(rn
);
146 static int nhrp_shortcut_do_purge(struct thread
*t
)
148 struct nhrp_shortcut
*s
= THREAD_ARG(t
);
150 nhrp_shortcut_delete(s
);
154 static struct nhrp_shortcut
*nhrp_shortcut_get(struct prefix
*p
)
156 struct nhrp_shortcut
*s
;
157 struct route_node
*rn
;
158 char buf
[PREFIX_STRLEN
];
159 afi_t afi
= family2afi(PREFIX_FAMILY(p
));
161 if (!shortcut_rib
[afi
])
164 rn
= route_node_get(shortcut_rib
[afi
], p
);
166 s
= rn
->info
= XCALLOC(MTYPE_NHRP_SHORTCUT
,
167 sizeof(struct nhrp_shortcut
));
168 s
->type
= NHRP_CACHE_INVALID
;
171 debugf(NHRP_DEBUG_ROUTE
, "Shortcut %s created",
172 prefix2str(s
->p
, buf
, sizeof buf
));
175 route_unlock_node(rn
);
180 static void nhrp_shortcut_recv_resolution_rep(struct nhrp_reqid
*reqid
,
183 struct nhrp_packet_parser
*pp
= arg
;
184 struct nhrp_shortcut
*s
=
185 container_of(reqid
, struct nhrp_shortcut
, reqid
);
186 struct nhrp_shortcut
*ps
;
187 struct nhrp_extension_header
*ext
;
188 struct nhrp_cie_header
*cie
;
189 struct nhrp_cache
*c
= NULL
;
190 union sockunion
*proto
, cie_proto
, *nbma
, *nbma_natoa
, cie_nbma
,
192 struct prefix prefix
, route_prefix
;
194 char bufp
[PREFIX_STRLEN
], buf
[3][SU_ADDRSTRLEN
];
195 int holding_time
= pp
->if_ad
->holdtime
;
197 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
198 THREAD_OFF(s
->t_timer
);
199 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 1, &s
->t_timer
);
201 if (pp
->hdr
->type
!= NHRP_PACKET_RESOLUTION_REPLY
) {
202 if (pp
->hdr
->type
== NHRP_PACKET_ERROR_INDICATION
203 && pp
->hdr
->u
.error
.code
204 == NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE
) {
205 debugf(NHRP_DEBUG_COMMON
,
206 "Shortcut: Resolution: Protocol address unreachable");
207 nhrp_shortcut_update_binding(s
, NHRP_CACHE_NEGATIVE
,
210 debugf(NHRP_DEBUG_COMMON
,
211 "Shortcut: Resolution failed");
216 /* Parse extensions */
217 memset(&nat_nbma
, 0, sizeof nat_nbma
);
218 while ((ext
= nhrp_ext_pull(&pp
->extensions
, &extpl
)) != NULL
) {
219 switch (htons(ext
->type
) & ~NHRP_EXTENSION_FLAG_COMPULSORY
) {
220 case NHRP_EXTENSION_NAT_ADDRESS
:
221 nhrp_cie_pull(&extpl
, pp
->hdr
, &nat_nbma
, &cie_proto
);
226 /* Minor sanity check */
227 prefix2sockunion(s
->p
, &cie_proto
);
228 if (!sockunion_same(&cie_proto
, &pp
->dst_proto
)) {
229 debugf(NHRP_DEBUG_COMMON
,
230 "Shortcut: Warning dst_proto altered from %s to %s",
231 sockunion2str(&cie_proto
, buf
[0], sizeof buf
[0]),
232 sockunion2str(&pp
->dst_proto
, buf
[1], sizeof buf
[1]));
235 /* One or more CIEs should be given as reply, we support only one */
236 cie
= nhrp_cie_pull(&pp
->payload
, pp
->hdr
, &cie_nbma
, &cie_proto
);
237 if (!cie
|| cie
->code
!= NHRP_CODE_SUCCESS
) {
238 debugf(NHRP_DEBUG_COMMON
, "Shortcut: CIE code %d",
239 cie
? cie
->code
: -1);
243 proto
= sockunion_family(&cie_proto
) != AF_UNSPEC
? &cie_proto
245 if (cie
->holding_time
)
246 holding_time
= htons(cie
->holding_time
);
249 prefix
.prefixlen
= cie
->prefix_length
;
251 /* Sanity check prefix length */
252 if (prefix
.prefixlen
>= 8 * prefix_blen(&prefix
)
253 || prefix
.prefixlen
== 0) {
254 prefix
.prefixlen
= 8 * prefix_blen(&prefix
);
255 } else if (nhrp_route_address(NULL
, &pp
->dst_proto
, &route_prefix
, NULL
)
256 == NHRP_ROUTE_NBMA_NEXTHOP
) {
257 if (prefix
.prefixlen
< route_prefix
.prefixlen
)
258 prefix
.prefixlen
= route_prefix
.prefixlen
;
261 debugf(NHRP_DEBUG_COMMON
,
262 "Shortcut: %s is at proto %s cie-nbma %s nat-nbma %s cie-holdtime %d",
263 prefix2str(&prefix
, bufp
, sizeof bufp
),
264 sockunion2str(proto
, buf
[0], sizeof buf
[0]),
265 sockunion2str(&cie_nbma
, buf
[1], sizeof buf
[1]),
266 sockunion2str(&nat_nbma
, buf
[2], sizeof buf
[2]),
267 htons(cie
->holding_time
));
269 /* Update cache entry for the protocol to nbma binding */
270 if (sockunion_family(&nat_nbma
) != AF_UNSPEC
) {
272 nbma_natoa
= &cie_nbma
;
277 if (sockunion_family(nbma
)) {
278 c
= nhrp_cache_get(pp
->ifp
, proto
, 1);
280 nhrp_cache_update_binding(c
, NHRP_CACHE_CACHED
,
282 nhrp_peer_get(pp
->ifp
, nbma
),
283 htons(cie
->mtu
), nbma_natoa
);
287 /* Update shortcut entry for subnet to protocol gw binding */
288 if (c
&& !sockunion_same(proto
, &pp
->dst_proto
)) {
289 ps
= nhrp_shortcut_get(&prefix
);
292 nhrp_shortcut_update_binding(ps
, NHRP_CACHE_CACHED
, c
,
297 debugf(NHRP_DEBUG_COMMON
, "Shortcut: Resolution reply handled");
300 static void nhrp_shortcut_send_resolution_req(struct nhrp_shortcut
*s
)
303 struct nhrp_packet_header
*hdr
;
304 struct interface
*ifp
;
305 struct nhrp_interface
*nifp
;
306 struct nhrp_peer
*peer
;
308 if (nhrp_route_address(NULL
, &s
->addr
, NULL
, &peer
)
309 != NHRP_ROUTE_NBMA_NEXTHOP
)
312 if (s
->type
== NHRP_CACHE_INVALID
|| s
->type
== NHRP_CACHE_NEGATIVE
)
313 s
->type
= NHRP_CACHE_INCOMPLETE
;
319 zb
= zbuf_alloc(1500);
320 hdr
= nhrp_packet_push(
321 zb
, NHRP_PACKET_RESOLUTION_REQUEST
, &nifp
->nbma
,
322 &nifp
->afi
[family2afi(sockunion_family(&s
->addr
))].addr
,
325 htonl(nhrp_reqid_alloc(&nhrp_packet_reqid
, &s
->reqid
,
326 nhrp_shortcut_recv_resolution_rep
));
327 hdr
->flags
= htons(NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER
328 | NHRP_FLAG_RESOLUTION_AUTHORATIVE
329 | NHRP_FLAG_RESOLUTION_SOURCE_STABLE
);
331 /* RFC2332 - One or zero CIEs, if CIE is present contains:
332 * - Prefix length: widest acceptable prefix we accept (if U set, 0xff)
333 * - MTU: MTU of the source station
334 * - Holding Time: Max time to cache the source information
336 /* FIXME: Send holding time, and MTU */
338 nhrp_ext_request(zb
, hdr
, ifp
);
340 /* Cisco NAT detection extension */
341 hdr
->flags
|= htons(NHRP_FLAG_RESOLUTION_NAT
);
342 nhrp_ext_push(zb
, hdr
, NHRP_EXTENSION_NAT_ADDRESS
);
344 nhrp_packet_complete(zb
, hdr
);
346 nhrp_peer_send(peer
, zb
);
347 nhrp_peer_unref(peer
);
351 void nhrp_shortcut_initiate(union sockunion
*addr
)
354 struct nhrp_shortcut
*s
;
356 sockunion2hostprefix(addr
, &p
);
357 s
= nhrp_shortcut_get(&p
);
358 if (s
&& s
->type
!= NHRP_CACHE_INCOMPLETE
) {
360 THREAD_OFF(s
->t_timer
);
361 thread_add_timer(master
, nhrp_shortcut_do_purge
, s
, 30,
363 nhrp_shortcut_send_resolution_req(s
);
367 void nhrp_shortcut_init(void)
369 shortcut_rib
[AFI_IP
] = route_table_init();
370 shortcut_rib
[AFI_IP6
] = route_table_init();
373 void nhrp_shortcut_terminate(void)
375 route_table_finish(shortcut_rib
[AFI_IP
]);
376 route_table_finish(shortcut_rib
[AFI_IP6
]);
379 void nhrp_shortcut_foreach(afi_t afi
,
380 void (*cb
)(struct nhrp_shortcut
*, void *),
383 struct route_table
*rt
= shortcut_rib
[afi
];
384 struct route_node
*rn
;
385 route_table_iter_t iter
;
390 route_table_iter_init(&iter
, rt
);
391 while ((rn
= route_table_iter_next(&iter
)) != NULL
) {
395 route_table_iter_cleanup(&iter
);
399 const struct prefix
*p
;
403 void nhrp_shortcut_purge(struct nhrp_shortcut
*s
, int force
)
405 THREAD_OFF(s
->t_timer
);
406 nhrp_reqid_free(&nhrp_packet_reqid
, &s
->reqid
);
409 /* Immediate purge on route with draw or pending shortcut */
410 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 5,
413 /* Soft expire - force immediate renewal, but purge
414 * in few seconds to make sure stale route is not
415 * used too long. In practice most purges are caused
416 * by hub bgp change, but target usually stays same.
417 * This allows to keep nhrp route up, and to not
418 * cause temporary rerouting via hubs causing latency
420 thread_add_timer_msec(master
, nhrp_shortcut_do_purge
, s
, 3000,
423 nhrp_shortcut_check_use(s
);
427 static void nhrp_shortcut_purge_prefix(struct nhrp_shortcut
*s
, void *ctx
)
429 struct purge_ctx
*pctx
= ctx
;
431 if (prefix_match(pctx
->p
, s
->p
))
432 nhrp_shortcut_purge(s
, pctx
->deleted
|| !s
->cache
);
435 void nhrp_shortcut_prefix_change(const struct prefix
*p
, int deleted
)
437 struct purge_ctx pctx
= {
438 .p
= p
, .deleted
= deleted
,
440 nhrp_shortcut_foreach(family2afi(PREFIX_FAMILY(p
)),
441 nhrp_shortcut_purge_prefix
, &pctx
);