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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_src_rr.h"
24 #include "fib_entry_cover.h"
25 #include "fib_entry.h"
26 #include "fib_table.h"
27 
28 /*
29  * fib_entry_src_rr_resolve_via_connected
30  *
31  * Resolve via a connected cover.
32  */
33 void
35  const fib_entry_t *fib_entry,
36  const fib_entry_t *cover)
37 {
38  const fib_route_path_t path = {
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)),
43  .frp_fib_index = ~0,
44  .frp_weight = 1,
45  };
46  fib_route_path_t *paths = NULL;
47  vec_add1(paths, path);
48 
49  /*
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.
55  */
59 
60  vec_free(paths);
61 }
62 
63 
64 /**
65  * Source initialisation Function
66  */
67 static void
69 {
70  src->u.rr.fesr_cover = FIB_NODE_INDEX_INVALID;
71  src->u.rr.fesr_sibling = FIB_NODE_INDEX_INVALID;
72 }
73 
74 
75 /*
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.
88  */
89 void
91  const fib_entry_t *fib_entry,
92  const fib_entry_t *cover)
93 {
95  dpo_proto_t proto;
96 
97  proto = fib_proto_to_dpo(fib_entry->fe_prefix.fp_proto);
98  vec_add1(entries, fib_entry_get_index(fib_entry));
99 
101  &entries))
102  {
105  drop_dpo_get(proto));
106  }
107  else
108  {
109  src->fes_pl = cover->fe_parent;
110  }
111  vec_free(entries);
112 }
113 
114 /*
115  * Source activation. Called when the source is the new best source on the entry
116  */
117 static int
119  const fib_entry_t *fib_entry)
120 {
121  fib_entry_t *cover;
122 
123  /*
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.
127  */
128  if (FIB_PROTOCOL_MPLS == fib_entry->fe_prefix.fp_proto)
129  {
132  NULL);
134  return (!0);
135  }
136 
137  src->u.rr.fesr_cover = fib_table_get_less_specific(fib_entry->fe_fib_index,
138  &fib_entry->fe_prefix);
139 
140  ASSERT(FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover);
141 
142  cover = fib_entry_get(src->u.rr.fesr_cover);
143 
144  src->u.rr.fesr_sibling =
145  fib_entry_cover_track(cover, fib_entry_get_index(fib_entry));
146 
147  /*
148  * if the cover is attached then install an attached-host path
149  * (like an adj-fib). Otherwise inherit the forwarding from the cover
150  */
152  {
153  fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
154  }
155  else
156  {
157  fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
158  }
160 
161  /*
162  * return go for install
163  */
164  return (!0);
165 }
166 
167 /**
168  * Source Deactivate.
169  * Called when the source is no longer best source on the entry
170  */
171 static void
173  const fib_entry_t *fib_entry)
174 {
175  fib_entry_t *cover;
176 
177  /*
178  * remove the dependency on the covering entry
179  */
180  if (FIB_NODE_INDEX_INVALID != src->u.rr.fesr_cover)
181  {
183 
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;
187 
188  if (FIB_NODE_INDEX_INVALID != cover->fe_parent)
189  {
191 
192  vec_free(entries);
193  }
194  }
195 
199 }
200 
203  const fib_entry_t *fib_entry)
204 {
206  .install = !0,
207  .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
208  };
209 
210  if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
211  {
212  /*
213  * the source may be added, but it is not active
214  * if it is not tracking the cover.
215  */
216  return (res);
217  }
218 
219  /*
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
223  */
224  if (src->u.rr.fesr_cover != fib_table_get_less_specific(fib_entry->fe_fib_index,
225  &fib_entry->fe_prefix))
226  {
227  fib_entry_src_rr_deactivate(src, fib_entry);
228  fib_entry_src_rr_activate(src, fib_entry);
229 
230  /*
231  * dependent children need to re-resolve to the new forwarding info
232  */
234  }
235  return (res);
236 }
237 
238 /*
239  * fib_entry_src_rr_cover_update
240  *
241  * This entry's cover has updated its forwarding info. This entry
242  * will need to re-inheret.
243  */
246  const fib_entry_t *fib_entry)
247 {
249  .install = !0,
250  .bw_reason = FIB_NODE_BW_REASON_FLAG_NONE,
251  };
252  fib_node_index_t old_path_list;
253  fib_entry_t *cover;
254 
255  if (FIB_NODE_INDEX_INVALID == src->u.rr.fesr_cover)
256  {
257  /*
258  * the source may be added, but it is not active
259  * if it is not tracking the cover.
260  */
261  return (res);
262  }
263 
264  cover = fib_entry_get(src->u.rr.fesr_cover);
265  old_path_list = src->fes_pl;
266 
267  /*
268  * if the ocver is attached then install an attached-host path
269  * (like an adj-fib). Otherwise inherit the forwarding from the cover
270  */
272  {
273  fib_entry_src_rr_resolve_via_connected(src, fib_entry, cover);
274  }
275  else
276  {
277  fib_entry_src_rr_use_covers_pl(src, fib_entry, cover);
278  }
280  fib_path_list_unlock(old_path_list);
281 
282  /*
283  * dependent children need to re-resolve to the new forwarding info
284  */
286 
287  return (res);
288 }
289 
290 static u8*
292  u8* s)
293 {
294  return (format(s, " cover:%d", src->u.rr.fesr_cover));
295 }
296 
297 const static fib_entry_src_vft_t rr_src_vft = {
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,
304 };
305 
306 void
308 {
309  fib_entry_src_register(FIB_SOURCE_RR, &rr_src_vft);
311 }
fib_protocol_t fp_proto
protocol type
Definition: fib_types.h:212
fib_entry_src_init_t fesv_init
Recursive resolution source.
Definition: fib_entry.h:125
void fib_entry_src_rr_resolve_via_connected(fib_entry_src_t *src, const fib_entry_t *fib_entry, const fib_entry_t *cover)
An entry in a FIB table.
Definition: fib_entry.h:462
fib_node_bw_reason_flag_t bw_reason
Definition: fib_entry_src.h:93
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:470
void fib_entry_cover_untrack(fib_entry_t *cover, u32 tracked_index)
union fib_entry_src_t_::@134 u
Source specific info.
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:58
Information related to the source of a FIB entry.
Definition: fib_entry.h:354
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:522
Result from a cover update/change.
Definition: fib_entry_src.h:91
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:424
dpo_proto_t frp_proto
The protocol of the address below.
Definition: fib_types.h:475
u32 fe_fib_index
The index of the FIB table this entry is in.
Definition: fib_entry.h:475
uRPF bypass/exemption.
Definition: fib_entry.h:130
Definition: fib_entry.h:277
unsigned char u8
Definition: types.h:56
fib_node_index_t fe_parent
the path-list for which this entry is a child.
Definition: fib_entry.h:499
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:62
enum dpo_proto_t_ dpo_proto_t
Data path protocol.
struct fib_entry_src_t_::@134::@135 rr
u16 install
Definition: fib_entry_src.h:92
Definition: fib_entry.h:275
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:226
void fib_path_list_lock(fib_node_index_t path_list_index)
vl_api_ip4_address_t src
Definition: ipsec_gre.api:38
u32 fib_entry_get_resolving_interface(fib_node_index_t entry_index)
Definition: fib_entry.c:1461
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:341
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:30
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:50
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:368
#define ASSERT(truth)
void fib_entry_src_register(fib_source_t source, const fib_entry_src_vft_t *vft)
Definition: fib_entry_src.c:56
dpo_proto_t fib_proto_to_dpo(fib_protocol_t fib_proto)
Definition: fib_types.c:237
u32 entries
void fib_entry_src_rr_use_covers_pl(fib_entry_src_t *src, const fib_entry_t *fib_entry, const fib_entry_t *cover)
fib_node_index_t fes_pl
The path-list created by the source.
Definition: fib_entry.h:363
static int fib_entry_src_rr_activate(fib_entry_src_t *src, const fib_entry_t *fib_entry)
#define FIB_ENTRY_FLAGS_RR_INHERITED
#define FIB_NODE_INDEX_INVALID
Definition: fib_types.h:31
fib_entry_src_cover_res_t fib_entry_src_rr_cover_update(fib_entry_src_t *src, const fib_entry_t *fib_entry)
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)
fib_entry_src_cover_res_t fib_entry_src_rr_cover_change(fib_entry_src_t *src, const fib_entry_t *fib_entry)
const fib_prefix_t fe_prefix
The prefix of the route.
Definition: fib_entry.h:471
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:301