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.
17 * The load-balance object represents an ECMP choice. The buckets of a load
18 * balance object point to the sub-graph after the choice is made.
19 * THe load-balance object is also object type returned from a FIB table lookup.
20 * As such it needs to represent the case where there is only one coice. It may
21 * seem like overkill to use a load-balance object in this case, but the reason
22 * is for performance. If the load-balance object were not the result of the FIB
23 * lookup, then some other object would be. The case where there was ECMP
24 * this other object would need a load-balance as a parent and hence just add
25 * an unnecessary indirection.
27 * It is also the object in the DP that represents a via-fib-entry in a recursive
32 #ifndef __LOAD_BALANCE_H__
33 #define __LOAD_BALANCE_H__
35 #include <vlib/vlib.h>
36 #include <vnet/ip/lookup.h>
37 #include <vnet/dpo/dpo.h>
38 #include <vnet/fib/fib_types.h>
39 #include <vnet/fib/fib_entry.h>
44 typedef struct load_balance_main_t_
46 vlib_combined_counter_main_t lbm_to_counters;
47 vlib_combined_counter_main_t lbm_via_counters;
48 } load_balance_main_t;
50 extern load_balance_main_t load_balance_main;
53 * The number of buckets that a load-balance object can have and still
54 * fit in one cache-line
56 #define LB_NUM_INLINE_BUCKETS 4
59 * @brief One path from an [EU]CMP set that the client wants to add to a
62 typedef struct load_balance_path_t_ {
64 * ID of the Data-path object.
69 * The index of the FIB path
71 fib_node_index_t path_index;
74 * weight for the path.
77 } load_balance_path_t;
80 * The FIB DPO provieds;
81 * - load-balancing over the next DPOs in the chain/graph
82 * - per-route counters
84 typedef struct load_balance_t_ {
86 * number of buckets in the load-balance. always a power of 2.
90 * number of buckets in the load-balance - 1. used in the switch path
91 * as part of the hash calculation.
93 u16 lb_n_buckets_minus_1;
96 * The protocol of packets that traverse this LB.
97 * need in combination with the flow hash config to determine how to hash.
100 dpo_proto_t lb_proto;
103 * Flags from the load-balance's associated fib_entry_t
105 fib_entry_flag_t lb_fib_entry_flags;
108 * The number of locks, which is approximately the number of users,
109 * of this load-balance.
110 * Load-balance objects of via-entries are heavily shared by recursives,
111 * so the lock count is a u32.
116 * index of the load-balance map, INVALID if this LB does not use one
121 * This is the index of the uRPF list for this LB
126 * the hash config to use when selecting a bucket. this is a u16
128 flow_hash_config_t lb_hash_config;
131 * Vector of buckets containing the next DPOs, sized as lbo_num
133 dpo_id_t *lb_buckets;
136 * The rest of the cache line is used for buckets. In the common case
137 * where there there are less than 4 buckets, then the buckets are
138 * on the same cachlie and we save ourselves a pointer dereferance in
141 dpo_id_t lb_buckets_inline[LB_NUM_INLINE_BUCKETS];
144 STATIC_ASSERT(sizeof(load_balance_t) <= CLIB_CACHE_LINE_BYTES,
145 "A load_balance object size exceeds one cachline");
148 * Flags controlling load-balance formatting/display
150 typedef enum load_balance_format_flags_t_ {
151 LOAD_BALANCE_FORMAT_NONE,
152 LOAD_BALANCE_FORMAT_DETAIL = (1 << 0),
153 } load_balance_format_flags_t;
156 * Flags controlling load-balance creation and modification
158 typedef enum load_balance_flags_t_ {
159 LOAD_BALANCE_FLAG_NONE = 0,
160 LOAD_BALANCE_FLAG_USES_MAP = (1 << 0),
161 } load_balance_flags_t;
163 extern index_t load_balance_create(u32 num_buckets,
164 dpo_proto_t lb_proto,
165 flow_hash_config_t fhc);
166 extern void load_balance_multipath_update(
168 const load_balance_path_t * raw_next_hops,
169 load_balance_flags_t flags);
171 extern void load_balance_set_bucket(index_t lbi,
173 const dpo_id_t *next);
174 extern void load_balance_set_urpf(index_t lbi,
176 extern void load_balance_set_fib_entry_flags(index_t lbi,
177 fib_entry_flag_t flags);
178 extern index_t load_balance_get_urpf(index_t lbi);
180 extern u8* format_load_balance(u8 * s, va_list * args);
182 extern const dpo_id_t *load_balance_get_bucket(index_t lbi,
184 extern int load_balance_is_drop(const dpo_id_t *dpo);
186 extern f64 load_balance_get_multipath_tolerance(void);
189 * The encapsulation breakages are for fast DP access
191 extern load_balance_t *load_balance_pool;
192 static inline load_balance_t*
193 load_balance_get (index_t lbi)
195 return (pool_elt_at_index(load_balance_pool, lbi));
198 #define LB_HAS_INLINE_BUCKETS(_lb) \
199 ((_lb)->lb_n_buckets <= LB_NUM_INLINE_BUCKETS)
201 static inline const dpo_id_t *
202 load_balance_get_bucket_i (const load_balance_t *lb,
205 ASSERT(bucket < lb->lb_n_buckets);
207 if (PREDICT_TRUE(LB_HAS_INLINE_BUCKETS(lb)))
209 return (&lb->lb_buckets_inline[bucket]);
213 return (&lb->lb_buckets[bucket]);
217 extern void load_balance_module_init(void);