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/*
* Copyright (c) 2016 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* \brief
* The load-balance object represents an ECMP choice. The buckets of a load
* balance object point to the sub-graph after the choice is made.
* THe load-balance object is also object type returned from a FIB table lookup.
* As such it needs to represent the case where there is only one coice. It may
* seem like overkill to use a load-balance object in this case, but the reason
* is for performance. If the load-balance object were not the result of the FIB
* lookup, then some other object would be. The case where there was ECMP
* this other object would need a load-balance as a parent and hence just add
* an unnecessary indirection.
*
* It is also the object in the DP that represents a via-fib-entry in a recursive
* route.
*
*/
#ifndef __LOAD_BALANCE_H__
#define __LOAD_BALANCE_H__
#include <vlib/vlib.h>
#include <vnet/ip/lookup.h>
#include <vnet/dpo/dpo.h>
#include <vnet/fib/fib_types.h>
/**
* Load-balance main
*/
typedef struct load_balance_main_t_
{
vlib_combined_counter_main_t lbm_to_counters;
vlib_combined_counter_main_t lbm_via_counters;
} load_balance_main_t;
extern load_balance_main_t load_balance_main;
/**
* The number of buckets that a load-balance object can have and still
* fit in one cache-line
*/
#define LB_NUM_INLINE_BUCKETS 4
/**
* @brief One path from an [EU]CMP set that the client wants to add to a
* load-balance object
*/
typedef struct load_balance_path_t_ {
/**
* ID of the Data-path object.
*/
dpo_id_t path_dpo;
/**
* The index of the FIB path
*/
fib_node_index_t path_index;
/**
* weight for the path.
*/
u32 path_weight;
} load_balance_path_t;
/**
* The FIB DPO provieds;
* - load-balancing over the next DPOs in the chain/graph
* - per-route counters
*/
typedef struct load_balance_t_ {
/**
* number of buckets in the load-balance. always a power of 2.
*/
u16 lb_n_buckets;
/**
* number of buckets in the load-balance - 1. used in the switch path
* as part of the hash calculation.
*/
u16 lb_n_buckets_minus_1;
/**
* The protocol of packets that traverse this LB.
* need in combination with the flow hash config to determine how to hash.
* u8.
*/
dpo_proto_t lb_proto;
/**
* The number of locks, which is approximately the number of users,
* of this load-balance.
* Load-balance objects of via-entries are heavily shared by recursives,
* so the lock count is a u32.
*/
u32 lb_locks;
/**
* index of the load-balance map, INVALID if this LB does not use one
*/
index_t lb_map;
/**
* This is the index of the uRPF list for this LB
*/
index_t lb_urpf;
/**
* the hash config to use when selecting a bucket. this is a u16
*/
flow_hash_config_t lb_hash_config;
/**
* Vector of buckets containing the next DPOs, sized as lbo_num
*/
dpo_id_t *lb_buckets;
/**
* The rest of the cache line is used for buckets. In the common case
* where there there are less than 4 buckets, then the buckets are
* on the same cachlie and we save ourselves a pointer dereferance in
* the data-path.
*/
dpo_id_t lb_buckets_inline[LB_NUM_INLINE_BUCKETS];
} load_balance_t;
STATIC_ASSERT(sizeof(load_balance_t) <= CLIB_CACHE_LINE_BYTES,
"A load_balance object size exceeds one cachline");
/**
* Flags controlling load-balance formatting/display
*/
typedef enum load_balance_format_flags_t_ {
LOAD_BALANCE_FORMAT_NONE,
LOAD_BALANCE_FORMAT_DETAIL = (1 << 0),
} load_balance_format_flags_t;
/**
* Flags controlling load-balance creation and modification
*/
typedef enum load_balance_flags_t_ {
LOAD_BALANCE_FLAG_NONE = 0,
LOAD_BALANCE_FLAG_USES_MAP = (1 << 0),
} load_balance_flags_t;
extern index_t load_balance_create(u32 num_buckets,
dpo_proto_t lb_proto,
flow_hash_config_t fhc);
extern void load_balance_multipath_update(
const dpo_id_t *dpo,
load_balance_path_t * raw_next_hops,
load_balance_flags_t flags);
extern void load_balance_set_bucket(index_t lbi,
u32 bucket,
const dpo_id_t *next);
extern void load_balance_set_urpf(index_t lbi,
index_t urpf);
extern index_t load_balance_get_urpf(index_t lbi);
extern u8* format_load_balance(u8 * s, va_list * args);
extern const dpo_id_t *load_balance_get_bucket(index_t lbi,
u32 bucket);
extern int load_balance_is_drop(const dpo_id_t *dpo);
extern f64 load_balance_get_multipath_tolerance(void);
/**
* The encapsulation breakages are for fast DP access
*/
extern load_balance_t *load_balance_pool;
static inline load_balance_t*
load_balance_get (index_t lbi)
{
return (pool_elt_at_index(load_balance_pool, lbi));
}
#define LB_HAS_INLINE_BUCKETS(_lb) \
((_lb)->lb_n_buckets <= LB_NUM_INLINE_BUCKETS)
static inline const dpo_id_t *
load_balance_get_bucket_i (const load_balance_t *lb,
u32 bucket)
{
ASSERT(bucket < lb->lb_n_buckets);
if (PREDICT_TRUE(LB_HAS_INLINE_BUCKETS(lb)))
{
return (&lb->lb_buckets_inline[bucket]);
}
else
{
return (&lb->lb_buckets[bucket]);
}
}
extern void load_balance_module_init(void);
#endif
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