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"
29 * fib_entry_src_rr_resolve_via_connected
31 * Resolve via a connected cover.
34 fib_entry_src_rr_resolve_via_connected (fib_entry_src_t *src,
35 const fib_entry_t *fib_entry,
36 const fib_entry_t *cover)
38 const fib_route_path_t path = {
39 .frp_proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto),
40 .frp_addr = fib_entry->fe_prefix.fp_addr,
41 .frp_sw_if_index = fib_entry_get_resolving_interface(
42 fib_entry_get_index(cover)),
46 fib_route_path_t *paths = NULL;
47 vec_add1(paths, path);
50 * since the cover is connected, the address this entry corresponds
51 * to is a peer (ARP-able for) on the interface to which the cover is
52 * connected. The fact we resolve via the cover, just means this RR
53 * source is the first SRC to use said peer. The ARP source will be along
54 * shortly to over-rule this RR source.
56 src->fes_pl = fib_path_list_create(FIB_PATH_LIST_FLAG_NONE, paths);
57 src->fes_entry_flags |= (fib_entry_get_flags(fib_entry_get_index(cover)) &
58 FIB_ENTRY_FLAGS_RR_INHERITED);
65 * Source initialisation Function
68 fib_entry_src_rr_init (fib_entry_src_t *src)
70 src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
71 src->u.rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
76 * use the path-list of the cover, unless it would form a loop.
77 * that is unless the cover is via this entry.
78 * If a loop were to form it would be a 1 level loop (i.e. X via X),
79 * and there would be 2 locks on the path-list; one since its used
80 * by the cover, and 1 from here. The first lock will go when the
81 * cover is removed, the second, and last, when the covered walk
82 * occurs during the cover's removal - this is not a place where
83 * we can handle last lock gone.
84 * In short, don't let the loop form. The usual rules of 'we must
85 * let it form so we know when it breaks' don't apply here, since
86 * the loop will break when the cover changes, and this function
87 * will be called again when that happens.
90 fib_entry_src_rr_use_covers_pl (fib_entry_src_t *src,
91 const fib_entry_t *fib_entry,
92 const fib_entry_t *cover)
94 fib_node_index_t *entries = NULL;
97 proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
98 vec_add1(entries, fib_entry_get_index(fib_entry));
100 if (fib_path_list_recursive_loop_detect(cover->fe_parent,
103 src->fes_pl = fib_path_list_create_special(proto,
104 FIB_PATH_LIST_FLAG_DROP,
105 drop_dpo_get(proto));
109 src->fes_pl = cover->fe_parent;
115 * Source activation. Called when the source is the new best source on the entry
118 fib_entry_src_rr_activate (fib_entry_src_t *src,
119 const fib_entry_t *fib_entry)
124 * find the covering prefix. become a dependent thereof.
125 * for IP there should always be a cover, though it may be the default route.
126 * For MPLS there is never a cover.
128 if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
130 src->fes_pl = fib_path_list_create_special(DPO_PROTO_MPLS,
131 FIB_PATH_LIST_FLAG_DROP,
133 fib_path_list_lock(src->fes_pl);
137 src->u.rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
138 &fib_entry->fe_prefix);
140 ASSERT(FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover);
142 cover = fib_entry_get(src->u.rr.fesr_cover);
144 src->u.rr.fesr_sibling =
145 fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
148 * if the cover is attached then install an attached-host path
149 * (like an adj-fib). Otherwise inherit the forwarding from the cover
151 if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
153 fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
157 fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
159 fib_path_list_lock(src->fes_pl);
162 * return go for install
169 * Called when the source is no longer best source on the entry
172 fib_entry_src_rr_deactivate (fib_entry_src_t *src,
173 const fib_entry_t *fib_entry)
178 * remove the dependency on the covering entry
180 if (FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover)
182 fib_node_index_t *entries = NULL;
184 cover = fib_entry_get(src->u.rr.fesr_cover);
185 fib_entry_cover_untrack(cover, src->u.rr.fesr_sibling);
186 src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
188 if (FIB_NODE_INDEX_INVALID != cover->fe_parent)
190 fib_path_list_recursive_loop_detect(cover->fe_parent, &entries);
196 fib_path_list_unlock(src->fes_pl);
197 src->fes_pl = FIB_NODE_INDEX_INVALID;
198 src->fes_entry_flags = FIB_ENTRY_FLAG_NONE;
201 fib_entry_src_cover_res_t
202 fib_entry_src_rr_cover_change (fib_entry_src_t *src,
203 const fib_entry_t *fib_entry)
205 fib_entry_src_cover_res_t res = {
207 .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
210 if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
213 * the source may be added, but it is not active
214 * if it is not tracking the cover.
220 * this function is called when this entry's cover has a more specific
221 * entry inserted benaeth it. That does not necessarily mean that this
222 * entry is covered by the new prefix. check that
224 if (src->u.rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
225 &fib_entry->fe_prefix))
227 fib_entry_src_rr_deactivate(src, fib_entry);
228 fib_entry_src_rr_activate(src, fib_entry);
231 * dependent children need to re-resolve to the new forwarding info
233 res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
239 * fib_entry_src_rr_cover_update
241 * This entry's cover has updated its forwarding info. This entry
242 * will need to re-inheret.
244 fib_entry_src_cover_res_t
245 fib_entry_src_rr_cover_update (fib_entry_src_t *src,
246 const fib_entry_t *fib_entry)
248 fib_entry_src_cover_res_t res = {
250 .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
252 fib_node_index_t old_path_list;
255 if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
258 * the source may be added, but it is not active
259 * if it is not tracking the cover.
264 cover = fib_entry_get(src->u.rr.fesr_cover);
265 old_path_list = src->fes_pl;
268 * if the ocver is attached then install an attached-host path
269 * (like an adj-fib). Otherwise inherit the forwarding from the cover
271 if (FIB_ENTRY_FLAG_ATTACHED & fib_entry_get_flags_i(cover))
273 fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
277 fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
279 fib_path_list_lock(src->fes_pl);
280 fib_path_list_unlock(old_path_list);
283 * dependent children need to re-resolve to the new forwarding info
285 res.bw_reason = FIB_NODE_BW_REASON_FLAG_EVALUATE;
291 fib_entry_src_rr_format (fib_entry_src_t *src,
294 return (format(s, " cover:%d", src->u.rr.fesr_cover));
297 const static fib_entry_src_vft_t rr_src_vft = {
298 .fesv_init = fib_entry_src_rr_init,
299 .fesv_activate = fib_entry_src_rr_activate,
300 .fesv_deactivate = fib_entry_src_rr_deactivate,
301 .fesv_cover_change = fib_entry_src_rr_cover_change,
302 .fesv_cover_update = fib_entry_src_rr_cover_update,
303 .fesv_format = fib_entry_src_rr_format,
307 fib_entry_src_rr_register (void)
309 fib_entry_src_behaviour_register(FIB_SOURCE_BH_RR, &rr_src_vft);