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Vector Packet Processing
fib_entry_src_rr.c
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1 /*
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:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
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.
14  */
15 
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>
21 
22 #include "fib_entry_src.h"
23 #include "fib_entry_cover.h"
24 #include "fib_entry.h"
25 #include "fib_table.h"
26 
27 /*
28  * fib_entry_src_rr_resolve_via_connected
29  *
30  * Resolve via a connected cover.
31  */
32 static void
34  const fib_entry_t *fib_entry,
35  const fib_entry_t *cover)
36 {
37  const fib_route_path_t path = {
39  .frp_addr = fib_entry->fe_prefix.fp_addr,
40  .frp_sw_if_index = fib_entry_get_resolving_interface(
41  fib_entry_get_index(cover)),
42  .frp_fib_index = ~0,
43  .frp_weight = 1,
44  };
45  fib_route_path_t *paths = NULL;
46  vec_add1(paths, path);
47 
48  /*
49  * since the cover is connected, the address this entry corresponds
50  * to is a peer (ARP-able for) on the interface to which the cover is
51  * connected. The fact we resolve via the cover, just means this RR
52  * source is the first SRC to use said peer. The ARP source will be along
53  * shortly to over-rule this RR source.
54  */
57 
58  vec_free(paths);
59 }
60 
61 
62 /**
63  * Source initialisation Function
64  */
65 static void
67 {
68  src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
69  src->rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
70 }
71 
72 
73 /*
74  * use the path-list of the cover, unless it would form a loop.
75  * that is unless the cover is via this entry.
76  * If a loop were to form it would be a 1 level loop (i.e. X via X),
77  * and there would be 2 locks on the path-list; one since its used
78  * by the cover, and 1 from here. The first lock will go when the
79  * cover is removed, the second, and last, when the covered walk
80  * occurs during the cover's removel - this is not a place where
81  * we can handle last lock gone.
82  * In short, don't let the loop form. The usual rules of 'we must
83  * let it form so we know when it breaks' don't apply here, since
84  * the loop will break when the cover changes, and this function
85  * will be called again when that happens.
86  */
87 static void
89  const fib_entry_t *fib_entry,
90  const fib_entry_t *cover)
91 {
92  fib_node_index_t *entries = NULL;
93  dpo_proto_t proto;
94 
95  proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
96  vec_add1(entries, fib_entry_get_index(fib_entry));
97 
99  &entries))
100  {
103  drop_dpo_get(proto));
104  }
105  else
106  {
107  src->fes_pl = cover->fe_parent;
108  }
109  vec_free(entries);
110 }
111 
112 /*
113  * Source activation. Called when the source is the new best source on the entry
114  */
115 static int
117  const fib_entry_t *fib_entry)
118 {
119  fib_entry_t *cover;
120 
121  /*
122  * find the covering prefix. become a dependent thereof.
123  * for IP there should always be a cover, though it may be the default route.
124  * For MPLS there is never a cover.
125  */
126  if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
127  {
130  NULL);
132  return (!0);
133  }
134 
135  src->rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
136  &fib_entry->fe_prefix);
137 
138  ASSERT(FIB_NODE_INDEX_INVALID != src->rr.fesr_cover);
139 
140  cover = fib_entry_get(src->rr.fesr_cover);
141 
142  src->rr.fesr_sibling =
143  fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
144 
145  /*
146  * if the cover is attached then install an attached-host path
147  * (like an adj-fib). Otherwise inherit the forwarding from the cover
148  */
150  {
151  fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
152  }
153  else
154  {
155  fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
156  }
158 
159  /*
160  * return go for install
161  */
162  return (!0);
163 }
164 
165 /**
166  * Source Deactivate.
167  * Called when the source is no longer best source on the entry
168  */
169 static void
171  const fib_entry_t *fib_entry)
172 {
173  fib_entry_t *cover;
174 
175  /*
176  * remove the depednecy on the covering entry
177  */
178  if (FIB_NODE_INDEX_INVALID != src->rr.fesr_cover)
179  {
180  cover = fib_entry_get(src->rr.fesr_cover);
181  fib_entry_cover_untrack(cover, src->rr.fesr_sibling);
182  src->rr.fesr_cover = FIB_NODE_INDEX_INVALID;
183  }
184 
188 }
189 
192  const fib_entry_t *fib_entry)
193 {
195  .install = !0,
196  .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
197  };
198 
199  if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
200  {
201  /*
202  * the source may be added, but it is not active
203  * if it is not tracking the cover.
204  */
205  return (res);
206  }
207 
208  /*
209  * this function is called when this entry's cover has a more specific
210  * entry inserted benaeth it. That does not necessarily mean that this
211  * entry is covered by the new prefix. check that
212  */
213  if (src->rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
214  &fib_entry->fe_prefix))
215  {
216  fib_entry_src_rr_deactivate(src, fib_entry);
217  fib_entry_src_rr_activate(src, fib_entry);
218 
219  /*
220  * dependent children need to re-resolve to the new forwarding info
221  */
223  }
224  return (res);
225 }
226 
227 /*
228  * fib_entry_src_rr_cover_update
229  *
230  * This entry's cover has updated its forwarding info. This entry
231  * will need to re-inheret.
232  */
235  const fib_entry_t *fib_entry)
236 {
238  .install = !0,
239  .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
240  };
241  fib_node_index_t old_path_list;
242  fib_entry_t *cover;
243 
244  if (FIB_NODE_INDEX_INVALID == src->rr.fesr_cover)
245  {
246  /*
247  * the source may be added, but it is not active
248  * if it is not tracking the cover.
249  */
250  return (res);
251  }
252 
253  cover = fib_entry_get(src->rr.fesr_cover);
254  old_path_list = src->fes_pl;
255 
256  /*
257  * if the ocver is attached then install an attached-host path
258  * (like an adj-fib). Otherwise inherit the forwarding from the cover
259  */
261  {
262  fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
263  }
264  else
265  {
266  fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
267  }
269  fib_path_list_unlock(old_path_list);
270 
271  /*
272  * dependent children need to re-resolve to the new forwarding info
273  */
275 
276  return (res);
277 }
278 
279 static u8*
281  u8* s)
282 {
283  return (format(s, "cover:%d", src->rr.fesr_cover));
284 }
285 
286 const static fib_entry_src_vft_t rr_src_vft = {
288  .fesv_activate = fib_entry_src_rr_activate,
289  .fesv_deactivate = fib_entry_src_rr_deactivate,
290  .fesv_cover_change = fib_entry_src_rr_cover_change,
291  .fesv_cover_update = fib_entry_src_rr_cover_update,
292  .fesv_format = fib_entry_src_rr_format,
293 };
294 
295 void
297 {
298  fib_entry_src_register(FIB_SOURCE_RR, &rr_src_vft);
300 }
fib_protocol_t fp_proto
protocol type
Definition: fib_types.h:181
fib_entry_src_init_t fesv_init
Recursive resolution source.
Definition: fib_entry.h:117
An entry in a FIB table.
Definition: fib_entry.h:385
fib_node_bw_reason_flag_t bw_reason
Definition: fib_entry_src.h:89
fib_entry_flag_t fib_entry_get_flags_i(const fib_entry_t *fib_entry)
A representation of a path as described by a route producer.
Definition: fib_types.h:377
void fib_entry_cover_untrack(fib_entry_t *cover, u32 tracked_index)
void fib_entry_src_rr_register(void)
Virtual function table each FIB entry source will register.
Definitions for all things IP (v4|v6) unicast and multicast lookup related.
#define NULL
Definition: clib.h:55
Information related to the source of a FIB entry.
Definition: fib_entry.h:294
fib_node_index_t fib_path_list_create_special(dpo_proto_t nh_proto, fib_path_list_flags_t flags, const dpo_id_t *dpo)
#define vec_add1(V, E)
Add 1 element to end of vector (unspecified alignment).
Definition: vec.h:518
Result from a cover update/change.
Definition: fib_entry_src.h:87
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
dpo_proto_t frp_proto
The protocol of the address below.
Definition: fib_types.h:382
u32 fe_fib_index
The index of the FIB table this entry is in.
Definition: fib_entry.h:398
uRPF bypass/exemption.
Definition: fib_entry.h:122
Definition: fib_entry.h:240
fib_node_index_t fe_parent
the path-list for which this entry is a child.
Definition: fib_entry.h:422
static void fib_entry_src_rr_init(fib_entry_src_t *src)
Source initialisation Function.
const dpo_id_t * drop_dpo_get(dpo_proto_t proto)
Definition: drop_dpo.c:25
u32 fib_entry_cover_track(fib_entry_t *cover, fib_node_index_t covered)
fib_node_index_t fib_entry_get_index(const fib_entry_t *fib_entry)
Definition: fib_entry.c:56
enum dpo_proto_t_ dpo_proto_t
Data path protocol.
u16 install
Definition: fib_entry_src.h:88
Definition: fib_entry.h:238
static fib_entry_src_cover_res_t fib_entry_src_rr_cover_change(fib_entry_src_t *src, const fib_entry_t *fib_entry)
fib_node_index_t fib_path_list_create(fib_path_list_flags_t flags, const fib_route_path_t *rpaths)
ip46_address_t fp_addr
The address type is not deriveable from the fp_addr member.
Definition: fib_types.h:195
void fib_path_list_lock(fib_node_index_t path_list_index)
static void fib_entry_src_rr_resolve_via_connected(fib_entry_src_t *src, const fib_entry_t *fib_entry, const fib_entry_t *cover)
struct fib_entry_src_t_::@109::@111 rr
static fib_entry_src_cover_res_t fib_entry_src_rr_cover_update(fib_entry_src_t *src, const fib_entry_t *fib_entry)
u32 fib_entry_get_resolving_interface(fib_node_index_t entry_index)
Definition: fib_entry.c:1352
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:336
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:29
void fib_path_list_unlock(fib_node_index_t path_list_index)
fib_entry_t * fib_entry_get(fib_node_index_t index)
Definition: fib_entry.c:44
int fib_path_list_recursive_loop_detect(fib_node_index_t path_list_index, fib_node_index_t **entry_indicies)
fib_entry_flag_t fes_entry_flags
Flags the source contributes to the entry.
Definition: fib_entry.h:323
#define ASSERT(truth)
void fib_entry_src_register(fib_source_t source, const fib_entry_src_vft_t *vft)
Definition: fib_entry_src.c:33
dpo_proto_t fib_proto_to_dpo(fib_protocol_t fib_proto)
Definition: fib_types.c:211
fib_node_index_t fes_pl
The path-list created by the source.
Definition: fib_entry.h:303
static int fib_entry_src_rr_activate(fib_entry_src_t *src, const fib_entry_t *fib_entry)
static void fib_entry_src_rr_use_covers_pl(fib_entry_src_t *src, const fib_entry_t *fib_entry, const fib_entry_t *cover)
#define FIB_NODE_INDEX_INVALID
Definition: fib_types.h:30
unsigned char u8
Definition: types.h:56
static void fib_entry_src_rr_deactivate(fib_entry_src_t *src, const fib_entry_t *fib_entry)
Source Deactivate.
static u8 * fib_entry_src_rr_format(fib_entry_src_t *src, u8 *s)
const fib_prefix_t fe_prefix
The prefix of the route.
Definition: fib_entry.h:394
fib_node_index_t fib_table_get_less_specific(u32 fib_index, const fib_prefix_t *prefix)
Get the less specific (covering) prefix.
Definition: fib_table.c:131
fib_entry_flag_t fib_entry_get_flags(fib_node_index_t fib_entry_index)
Definition: fib_entry.c:265