2 * Copyright (c) 2016 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vlib/vlib.h>
17 #include <vnet/ip/format.h>
18 #include <vnet/ip/lookup.h>
19 #include <vnet/adj/adj.h>
20 #include <vnet/dpo/drop_dpo.h>
22 #include "fib_entry_src.h"
23 #include "fib_entry_src_rr.h"
24 #include "fib_entry_cover.h"
25 #include "fib_entry.h"
26 #include "fib_table.h"
27 #include "fib_path_ext.h"
30 * fib_entry_src_rr_resolve_via_connected
32 * Resolve via a connected cover.
35 fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
36 const fib_entry_t *fib_entry,
37 const fib_entry_t *cover)
39 const fib_route_path_t path = {
40 .frp_proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto),
41 .frp_addr = fib_entry->fe_prefix.fp_addr,
42 .frp_sw_if_index = fib_entry_get_resolving_interface(
43 fib_entry_get_index(cover)),
47 fib_route_path_t *paths = NULL;
48 vec_add1(paths, path);
51 * since the cover is connected, the address this entry corresponds
52 * to is a peer (ARP-able for) on the interface to which the cover is
53 * connected. The fact we resolve via the cover, just means this RR
54 * source is the first SRC to use said peer. The ARP source will be along
55 * shortly to over-rule this RR source.
57 src->fes_pl = fib_path_list_create(FIB_PATH_LIST_FLAG_NONE, paths);
58 src->fes_entry_flags |= (fib_entry_get_flags(fib_entry_get_index(cover)) &
59 FIB_ENTRY_FLAGS_RR_INHERITED);
66 * Source initialisation Function
69 fib_entry_src_rr_init (fib_entry_src_t *src)
71 src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
72 src->u.rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
77 * use the path-list of the cover, unless it would form a loop.
78 * that is unless the cover is via this entry.
79 * If a loop were to form it would be a 1 level loop (i.e. X via X),
80 * and there would be 2 locks on the path-list; one since its used
81 * by the cover, and 1 from here. The first lock will go when the
82 * cover is removed, the second, and last, when the covered walk
83 * occurs during the cover's removal - this is not a place where
84 * we can handle last lock gone.
85 * In short, don't let the loop form. The usual rules of 'we must
86 * let it form so we know when it breaks' don't apply here, since
87 * the loop will break when the cover changes, and this function
88 * will be called again when that happens.
91 fib_entry_src_rr_use_covers_pl (fib_entry_src_t *src,
92 const fib_entry_t *fib_entry,
93 const fib_entry_t *cover)
95 fib_node_index_t *entries = NULL;
99 proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
100 vec_add1(entries, fib_entry_get_index(fib_entry));
102 if (fib_path_list_recursive_loop_detect(cover->fe_parent,
105 src->fes_pl = fib_path_list_create_special(proto,
106 FIB_PATH_LIST_FLAG_DROP,
107 drop_dpo_get(proto));
111 src->fes_pl = cover->fe_parent;
112 vec_foreach (s,cover->fe_srcs)
114 if (s->fes_pl != cover->fe_parent)
117 src->fes_path_exts.fpel_exts = vec_dup (s->fes_path_exts.fpel_exts);
125 * Source activation. Called when the source is the new best source on the entry
128 fib_entry_src_rr_activate (fib_entry_src_t *src,
129 const fib_entry_t *fib_entry)
134 * find the covering prefix. become a dependent thereof.
135 * for IP there should always be a cover, though it may be the default route.
136 * For MPLS there is never a cover.
138 if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
140 src->fes_pl = fib_path_list_create_special(DPO_PROTO_MPLS,
141 FIB_PATH_LIST_FLAG_DROP,
143 fib_path_list_lock(src->fes_pl);
147 src->u.rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
148 &fib_entry->fe_prefix);
150 ASSERT(FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover);
152 cover = fib_entry_get(src->u.rr.fesr_cover);
154 src->u.rr.fesr_sibling =
155 fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
158 * if the cover is attached then install an attached-host path
159 * (like an adj-fib). Otherwise inherit the forwarding from the cover
161 if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
163 fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
167 fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
169 fib_path_list_lock(src->fes_pl);
172 * return go for install
179 * Called when the source is no longer best source on the entry
182 fib_entry_src_rr_deactivate (fib_entry_src_t *src,
183 const fib_entry_t *fib_entry)
188 * remove the dependency on the covering entry
190 if (FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover)
192 fib_node_index_t *entries = NULL;
194 cover = fib_entry_get(src->u.rr.fesr_cover);
195 fib_entry_cover_untrack(cover, src->u.rr.fesr_sibling);
196 src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
198 if (FIB_NODE_INDEX_INVALID != cover->fe_parent)
200 fib_path_list_recursive_loop_detect(cover->fe_parent, &entries);
206 fib_path_list_unlock(src->fes_pl);
207 src->fes_pl = FIB_NODE_INDEX_INVALID;
208 vec_free (src->fes_path_exts.fpel_exts);
209 src->fes_entry_flags = FIB_ENTRY_FLAG_NONE;
212 fib_entry_src_cover_res_t
213 fib_entry_src_rr_cover_change (fib_entry_src_t *src,
214 const fib_entry_t *fib_entry)
216 fib_entry_src_cover_res_t res = {
218 .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
221 if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
224 * the source may be added, but it is not active
225 * if it is not tracking the cover.
231 * this function is called when this entry's cover has a more specific
232 * entry inserted benaeth it. That does not necessarily mean that this
233 * entry is covered by the new prefix. check that
235 if (src->u.rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
236 &fib_entry->fe_prefix))
238 fib_entry_src_rr_deactivate(src, fib_entry);
239 fib_entry_src_rr_activate(src, fib_entry);
242 * dependent children need to re-resolve to the new forwarding info
244 res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
250 * fib_entry_src_rr_cover_update
252 * This entry's cover has updated its forwarding info. This entry
253 * will need to re-inheret.
255 fib_entry_src_cover_res_t
256 fib_entry_src_rr_cover_update (fib_entry_src_t *src,
257 const fib_entry_t *fib_entry)
259 fib_entry_src_cover_res_t res = {
261 .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
263 fib_node_index_t old_path_list;
266 if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
269 * the source may be added, but it is not active
270 * if it is not tracking the cover.
275 cover = fib_entry_get(src->u.rr.fesr_cover);
276 old_path_list = src->fes_pl;
279 * if the ocver is attached then install an attached-host path
280 * (like an adj-fib). Otherwise inherit the forwarding from the cover
282 if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
284 fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
288 fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
290 fib_path_list_lock(src->fes_pl);
291 fib_path_list_unlock(old_path_list);
294 * dependent children need to re-resolve to the new forwarding info
296 res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
302 fib_entry_src_rr_format (fib_entry_src_t *src,
305 return (format(s, " cover:%d", src->u.rr.fesr_cover));
308 const static fib_entry_src_vft_t rr_src_vft = {
309 .fesv_init = fib_entry_src_rr_init,
310 .fesv_activate = fib_entry_src_rr_activate,
311 .fesv_deactivate = fib_entry_src_rr_deactivate,
312 .fesv_cover_change = fib_entry_src_rr_cover_change,
313 .fesv_cover_update = fib_entry_src_rr_cover_update,
314 .fesv_format = fib_entry_src_rr_format,
318 fib_entry_src_rr_register (void)
320 fib_entry_src_behaviour_register(FIB_SOURCE_BH_RR, &rr_src_vft);