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 * @brief The IPv4 FIB
17 *
18 * FIBs are composed of two prefix data-bases (akak tables). The non-forwarding
19 * table contains all the routes that the control plane has programmed, the
20 * forwarding table contains the sub-set of those routes that can be used to
21 * forward packets.
22 * In the IPv4 FIB the non-forwarding table is an array of hash tables indexed
23 * by mask length, the forwarding table is an mtrie
24 *
25 * This IPv4 FIB is used by the protocol independent FIB. So directly using
26 * this APIs in client code is not encouraged. However, this IPv4 FIB can be
27 * used if all the client wants is an IPv4 prefix data-base
28 */
29
30#ifndef __IP4_FIB_H__
31#define __IP4_FIB_H__
32
33#include <vlib/vlib.h>
34#include <vnet/ip/ip.h>
35#include <vnet/fib/fib_entry.h>
36#include <vnet/fib/fib_table.h>
37#include <vnet/ip/ip4_mtrie.h>
38
39typedef struct ip4_fib_t_
40{
41  /** Required for pool_get_aligned */
42  CLIB_CACHE_LINE_ALIGN_MARK(cacheline0);
43
44  /**
45   * Mtrie for fast lookups. Hash is used to maintain overlapping prefixes.
46   * First member so it's in the first cacheline.
47   */
48  ip4_fib_mtrie_t mtrie;
49
50  /* Hash table for each prefix length mapping. */
51  uword *fib_entry_by_dst_address[33];
52
53  /* Table ID (hash key) for this FIB. */
54  u32 table_id;
55
56  /* Index into FIB vector. */
57  u32 index;
58} ip4_fib_t;
59
60extern fib_node_index_t ip4_fib_table_lookup(const ip4_fib_t *fib,
61					     const ip4_address_t *addr,
62					     u32 len);
63extern fib_node_index_t ip4_fib_table_lookup_exact_match(const ip4_fib_t *fib,
64							 const ip4_address_t *addr,
65							 u32 len);
66
67extern void ip4_fib_table_entry_remove(ip4_fib_t *fib,
68				       const ip4_address_t *addr,
69				       u32 len);
70
71extern void ip4_fib_table_entry_insert(ip4_fib_t *fib,
72				       const ip4_address_t *addr,
73				       u32 len,
74				       fib_node_index_t fib_entry_index);
75extern void ip4_fib_table_destroy(u32 fib_index);
76
77extern void ip4_fib_table_fwding_dpo_update(ip4_fib_t *fib,
78					    const ip4_address_t *addr,
79					    u32 len,
80					    const dpo_id_t *dpo);
81
82extern void ip4_fib_table_fwding_dpo_remove(ip4_fib_t *fib,
83					    const ip4_address_t *addr,
84					    u32 len,
85					    const dpo_id_t *dpo,
86                                            fib_node_index_t cover_index);
87extern u32 ip4_fib_table_lookup_lb (ip4_fib_t *fib,
88				    const ip4_address_t * dst);
89
90/**
91 * @brief Walk all entries in a FIB table
92 * N.B: This is NOT safe to deletes. If you need to delete walk the whole
93 * table and store elements in a vector, then delete the elements
94 */
95extern void ip4_fib_table_walk(ip4_fib_t *fib,
96                               fib_table_walk_fn_t fn,
97                               void *ctx);
98
99/**
100 * @brief Walk all entries in a sub-tree of the FIB table
101 * N.B: This is NOT safe to deletes. If you need to delete walk the whole
102 * table and store elements in a vector, then delete the elements
103 */
104extern void ip4_fib_table_sub_tree_walk(ip4_fib_t *fib,
105                                        const fib_prefix_t *root,
106                                        fib_table_walk_fn_t fn,
107                                        void *ctx);
108
109/**
110 * @brief Get the FIB at the given index
111 */
112static inline ip4_fib_t *
113ip4_fib_get (u32 index)
114{
115    return (pool_elt_at_index(ip4_main.v4_fibs, index));
116}
117
118always_inline u32
119ip4_fib_lookup (ip4_main_t * im, u32 sw_if_index, ip4_address_t * dst)
120{
121    return (ip4_fib_table_lookup_lb(
122		ip4_fib_get(vec_elt (im->fib_index_by_sw_if_index, sw_if_index)),
123		dst));
124}
125
126/**
127 * @brief Get or create an IPv4 fib.
128 *
129 * Get or create an IPv4 fib with the provided table ID.
130 *
131 * @param table_id
132 *      When set to \c ~0, an arbitrary and unused fib ID is picked
133 *      and can be retrieved with \c ret->table_id.
134 *      Otherwise, the fib ID to be used to retrieve or create the desired fib.
135 * @returns A pointer to the retrieved or created fib.
136 *
137 */
138extern u32 ip4_fib_table_find_or_create_and_lock(u32 table_id,
139                                                 fib_source_t src);
140extern u32 ip4_fib_table_create_and_lock(fib_source_t src);
141
142extern u8 *format_ip4_fib_table_memory(u8 * s, va_list * args);
143
144static inline
145u32 ip4_fib_index_from_table_id (u32 table_id)
146{
147  ip4_main_t * im = &ip4_main;
148  uword * p;
149
150  p = hash_get (im->fib_index_by_table_id, table_id);
151  if (!p)
152    return ~0;
153
154  return p[0];
155}
156
157extern u32 ip4_fib_table_get_index_for_sw_if_index(u32 sw_if_index);
158
159always_inline index_t
160ip4_fib_forwarding_lookup (u32 fib_index,
161                           const ip4_address_t * addr)
162{
163    ip4_fib_mtrie_leaf_t leaf;
164    ip4_fib_mtrie_t * mtrie;
165
166    mtrie = &ip4_fib_get(fib_index)->mtrie;
167
168    leaf = ip4_fib_mtrie_lookup_step_one (mtrie, addr);
169    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 2);
170    leaf = ip4_fib_mtrie_lookup_step (mtrie, leaf, addr, 3);
171
172    return (ip4_fib_mtrie_leaf_get_adj_index(leaf));
173}
174
175static_always_inline void
176ip4_fib_forwarding_lookup_x2 (u32 fib_index0,
177                              u32 fib_index1,
178                              const ip4_address_t * addr0,
179                              const ip4_address_t * addr1,
180                              index_t *lb0,
181                              index_t *lb1)
182{
183    ip4_fib_mtrie_leaf_t leaf[2];
184    ip4_fib_mtrie_t * mtrie[2];
185
186    mtrie[0] = &ip4_fib_get(fib_index0)->mtrie;
187    mtrie[1] = &ip4_fib_get(fib_index1)->mtrie;
188
189    leaf[0] = ip4_fib_mtrie_lookup_step_one (mtrie[0], addr0);
190    leaf[1] = ip4_fib_mtrie_lookup_step_one (mtrie[1], addr1);
191    leaf[0] = ip4_fib_mtrie_lookup_step (mtrie[0], leaf[0], addr0, 2);
192    leaf[1] = ip4_fib_mtrie_lookup_step (mtrie[1], leaf[1], addr1, 2);
193    leaf[0] = ip4_fib_mtrie_lookup_step (mtrie[0], leaf[0], addr0, 3);
194    leaf[1] = ip4_fib_mtrie_lookup_step (mtrie[1], leaf[1], addr1, 3);
195
196    *lb0 = ip4_fib_mtrie_leaf_get_adj_index(leaf[0]);
197    *lb1 = ip4_fib_mtrie_leaf_get_adj_index(leaf[1]);
198}
199
200#endif
201
202