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 * lb-plugin implements a MagLev-like load balancer.
18 * http://research.google.com/pubs/pub44824.html
20 * It hasn't been tested for interoperability with the original MagLev
21 * but intends to provide similar functionality.
22 * The load-balancer receives traffic destined to VIP (Virtual IP)
23 * addresses from one or multiple(ECMP) routers.
24 * The load-balancer tunnels the traffic toward many application servers
25 * ensuring session stickyness (i.e. that a single sessions is tunneled
26 * towards a single application server).
30 #ifndef LB_PLUGIN_LB_LB_H_
31 #define LB_PLUGIN_LB_LB_H_
34 #include <lb/refcount.h>
36 #include <vnet/vnet.h>
37 #include <vnet/ip/ip.h>
38 #include <vnet/dpo/dpo.h>
39 #include <vnet/fib/fib_table.h>
41 #include <lb/lbhash.h>
43 #define LB_DEFAULT_PER_CPU_STICKY_BUCKETS 1 << 10
44 #define LB_DEFAULT_FLOW_TIMEOUT 40
52 * Each VIP is configured with a set of
57 * Registration to FIB event.
62 * Destination address used to tunnel traffic towards
63 * that application server.
64 * The address is also used as ID and pseudo-random
65 * seed for the load-balancing process.
67 ip46_address_t address;
70 * ASs are indexed by address and VIP Index.
71 * Which means there will be duplicated if the same server
72 * address is used for multiple VIPs.
78 * For now only LB_AS_FLAGS_USED is defined.
82 #define LB_AS_FLAGS_USED 0x1
85 * Rotating timestamp of when LB_AS_FLAGS_USED flag was last set.
87 * AS removal is based on garbage collection and reference counting.
88 * When an AS is removed, there is a race between configuration core
89 * and worker cores which may still add a reference while it should not
90 * be used. This timestamp is used to not remove the AS while a race condition
96 * The FIB entry index for the next-hop
98 fib_node_index_t next_hop_fib_entry_index;
101 * The child index on the FIB entry
103 u32 next_hop_child_index;
106 * The next DPO in the graph to follow.
112 format_function_t format_lb_as;
116 } lb_new_flow_entry_t;
118 #define lb_foreach_vip_counter \
119 _(NEXT_PACKET, "packet from existing sessions", 0) \
120 _(FIRST_PACKET, "first session packet", 1) \
121 _(UNTRACKED_PACKET, "untracked packet", 2) \
122 _(NO_SERVER, "no server configured", 3)
125 #define _(a,b,c) LB_VIP_COUNTER_##a = c,
126 lb_foreach_vip_counter
132 * The load balancer supports IPv4 and IPv6 traffic
133 * and GRE4 and GRE6 encap.
136 LB_VIP_TYPE_IP6_GRE6,
137 LB_VIP_TYPE_IP6_GRE4,
138 LB_VIP_TYPE_IP4_GRE6,
139 LB_VIP_TYPE_IP4_GRE4,
143 format_function_t format_lb_vip_type;
144 unformat_function_t unformat_lb_vip_type;
147 * Load balancing service is provided per VIP.
148 * In this data model, a VIP can be a whole prefix.
149 * But load balancing only
150 * occurs on a per-source-address/port basis. Meaning that if a given source
151 * reuses the same port for multiple destinations within the same VIP,
152 * they will be considered as a single flow.
159 * Vector mapping (flow-hash & new_connect_table_mask) to AS index.
160 * This is used for new flows.
162 lb_new_flow_entry_t *new_flow_table;
165 * New flows table length - 1
166 * (length MUST be a power of 2)
168 u32 new_flow_table_mask;
171 * Last time garbage collection was run to free the ASs.
173 u32 last_garbage_collection;
178 * A Virtual IP represents a given service delivered
179 * by a set of application servers. It can be a single
180 * address or a prefix.
181 * IPv4 prefixes are encoded using IPv4-in-IPv6 embedded address
182 * (i.e. ::/96 prefix).
184 ip46_address_t prefix;
187 * The VIP prefix length.
188 * In case of IPv4, plen = 96 + ip4_plen.
193 * The type of traffic for this.
194 * LB_TYPE_UNDEFINED if unknown.
199 * Flags related to this VIP.
200 * LB_VIP_FLAGS_USED means the VIP is active.
201 * When it is not set, the VIP in the process of being removed.
202 * We cannot immediately remove a VIP because the VIP index still may be stored
203 * in the adjacency index.
206 #define LB_VIP_FLAGS_USED 0x1
209 * Pool of AS indexes used for this VIP.
210 * This also includes ASs that have been removed (but are still referenced).
215 #define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
216 #define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
217 format_function_t format_lb_vip;
218 format_function_t format_lb_vip_detailed;
222 * Each CPU has its own sticky flow hash table.
223 * One single table is used for all VIPs.
225 lb_hash_t *sticky_ht;
230 * Pool of all Virtual IPs
236 * ASs are referenced by address and vip index.
237 * The first element (index 0) is special and used only to fill
238 * new_flow_tables when no AS has been configured.
243 * Each AS has an associated reference counter.
244 * As ass[0] has a special meaning, its associated counter
245 * starts at 0 and is decremented instead. i.e. do not use it.
247 vlib_refcount_t as_refcount;
250 * Some global data is per-cpu
252 lb_per_cpu_t *per_cpu;
255 * Node next index for IP adjacencies, for each of the traffic types.
257 u32 ip_lookup_next_index[LB_VIP_N_TYPES];
260 * Source address used in IPv6 encapsulated traffic
262 ip6_address_t ip6_src_address;
265 * Source address used for IPv4 encapsulated traffic
267 ip4_address_t ip4_src_address;
270 * Number of buckets in the per-cpu sticky hash table.
272 u32 per_cpu_sticky_buckets;
275 * Flow timeout in seconds.
282 vlib_simple_counter_main_t vip_counters[LB_N_VIP_COUNTERS];
285 * DPO used to send packet from IP4/6 lookup to LB node.
287 dpo_type_t dpo_gre4_type;
288 dpo_type_t dpo_gre6_type;
291 * Node type for registering to fib changes.
293 fib_node_type_t fib_node_type;
296 * API dynamically registered base ID.
300 volatile u32 *writer_lock;
303 extern lb_main_t lb_main;
304 extern vlib_node_registration_t lb6_node;
305 extern vlib_node_registration_t lb4_node;
308 * Fix global load-balancer parameters.
309 * @param ip4_address IPv4 source address used for encapsulated traffic
310 * @param ip6_address IPv6 source address used for encapsulated traffic
311 * @return 0 on success. VNET_LB_ERR_XXX on error
313 int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address,
314 u32 sticky_buckets, u32 flow_timeout);
316 int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type,
317 u32 new_length, u32 *vip_index);
318 int lb_vip_del(u32 vip_index);
320 int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index);
322 #define lb_vip_get_by_index(index) (pool_is_free_index(lb_main.vips, index)?NULL:pool_elt_at_index(lb_main.vips, index))
324 int lb_vip_add_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
325 int lb_vip_del_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
327 u32 lb_hash_time_now(vlib_main_t * vm);
329 void lb_garbage_collection();
331 format_function_t format_lb_main;
333 #endif /* LB_PLUGIN_LB_LB_H_ */