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 <vnet/util/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>
40 #include <vppinfra/hash.h>
42 #include <lb/lbhash.h>
44 #define LB_DEFAULT_PER_CPU_STICKY_BUCKETS 1 << 10
45 #define LB_DEFAULT_FLOW_TIMEOUT 40
53 * Each VIP is configured with a set of
58 * Registration to FIB event.
63 * Destination address used to tunnel traffic towards
64 * that application server.
65 * The address is also used as ID and pseudo-random
66 * seed for the load-balancing process.
68 ip46_address_t address;
71 * ASs are indexed by address and VIP Index.
72 * Which means there will be duplicated if the same server
73 * address is used for multiple VIPs.
79 * For now only LB_AS_FLAGS_USED is defined.
83 #define LB_AS_FLAGS_USED 0x1
86 * Rotating timestamp of when LB_AS_FLAGS_USED flag was last set.
88 * AS removal is based on garbage collection and reference counting.
89 * When an AS is removed, there is a race between configuration core
90 * and worker cores which may still add a reference while it should not
91 * be used. This timestamp is used to not remove the AS while a race condition
97 * The FIB entry index for the next-hop
99 fib_node_index_t next_hop_fib_entry_index;
102 * The child index on the FIB entry
104 u32 next_hop_child_index;
107 * The next DPO in the graph to follow.
113 format_function_t format_lb_as;
117 } lb_new_flow_entry_t;
119 #define lb_foreach_vip_counter \
120 _(NEXT_PACKET, "packet from existing sessions", 0) \
121 _(FIRST_PACKET, "first session packet", 1) \
122 _(UNTRACKED_PACKET, "untracked packet", 2) \
123 _(NO_SERVER, "no server configured", 3)
126 #define _(a,b,c) LB_VIP_COUNTER_##a = c,
127 lb_foreach_vip_counter
140 * The load balancer supports IPv4 and IPv6 traffic
141 * and GRE4, GRE6 and L3DSR encap.
144 LB_VIP_TYPE_IP6_GRE6,
145 LB_VIP_TYPE_IP6_GRE4,
146 LB_VIP_TYPE_IP4_GRE6,
147 LB_VIP_TYPE_IP4_GRE4,
148 LB_VIP_TYPE_IP4_L3DSR,
153 format_function_t format_lb_vip_type;
154 unformat_function_t unformat_lb_vip_type;
157 * Load balancing service is provided per VIP.
158 * In this data model, a VIP can be a whole prefix.
159 * But load balancing only
160 * occurs on a per-source-address/port basis. Meaning that if a given source
161 * reuses the same port for multiple destinations within the same VIP,
162 * they will be considered as a single flow.
169 * Vector mapping (flow-hash & new_connect_table_mask) to AS index.
170 * This is used for new flows.
172 lb_new_flow_entry_t *new_flow_table;
175 * New flows table length - 1
176 * (length MUST be a power of 2)
178 u32 new_flow_table_mask;
181 * Last time garbage collection was run to free the ASs.
183 u32 last_garbage_collection;
188 * A Virtual IP represents a given service delivered
189 * by a set of application servers. It can be a single
190 * address or a prefix.
191 * IPv4 prefixes are encoded using IPv4-in-IPv6 embedded address
192 * (i.e. ::/96 prefix).
194 ip46_address_t prefix;
197 * The VIP prefix length.
198 * In case of IPv4, plen = 96 + ip4_plen.
203 * The type of traffic for this.
204 * LB_TYPE_UNDEFINED if unknown.
209 * DSCP bits for L3DSR
214 * Flags related to this VIP.
215 * LB_VIP_FLAGS_USED means the VIP is active.
216 * When it is not set, the VIP in the process of being removed.
217 * We cannot immediately remove a VIP because the VIP index still may be stored
218 * in the adjacency index.
221 #define LB_VIP_FLAGS_USED 0x1
224 * Pool of AS indexes used for this VIP.
225 * This also includes ASs that have been removed (but are still referenced).
230 #define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 \
231 || (vip)->type == LB_VIP_TYPE_IP4_GRE4 \
232 || (vip)->type == LB_VIP_TYPE_IP4_L3DSR )
234 #define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 \
235 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
236 #define lb_vip_is_gre6(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE6 \
237 || (vip)->type == LB_VIP_TYPE_IP4_GRE6)
238 #define lb_vip_is_l3dsr(vip) ((vip)->type == LB_VIP_TYPE_IP4_L3DSR)
240 #define lb_encap_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 \
241 || (vip)->type == LB_VIP_TYPE_IP4_GRE4 \
242 || (vip)->type == LB_VIP_TYPE_IP4_L3DSR)
244 format_function_t format_lb_vip;
245 format_function_t format_lb_vip_detailed;
249 * Each CPU has its own sticky flow hash table.
250 * One single table is used for all VIPs.
252 lb_hash_t *sticky_ht;
257 * Pool of all Virtual IPs
263 * ASs are referenced by address and vip index.
264 * The first element (index 0) is special and used only to fill
265 * new_flow_tables when no AS has been configured.
270 * Each AS has an associated reference counter.
271 * As ass[0] has a special meaning, its associated counter
272 * starts at 0 and is decremented instead. i.e. do not use it.
274 vlib_refcount_t as_refcount;
277 * Some global data is per-cpu
279 lb_per_cpu_t *per_cpu;
282 * Node next index for IP adjacencies, for each of the traffic types.
284 u32 ip_lookup_next_index[LB_VIP_N_TYPES];
287 * Source address used in IPv6 encapsulated traffic
289 ip6_address_t ip6_src_address;
292 * Source address used for IPv4 encapsulated traffic
294 ip4_address_t ip4_src_address;
297 * Number of buckets in the per-cpu sticky hash table.
299 u32 per_cpu_sticky_buckets;
302 * Flow timeout in seconds.
309 vlib_simple_counter_main_t vip_counters[LB_N_VIP_COUNTERS];
312 * DPO used to send packet from IP4/6 lookup to LB node.
314 dpo_type_t dpo_gre4_type;
315 dpo_type_t dpo_gre6_type;
316 dpo_type_t dpo_l3dsr_type;
319 * Node type for registering to fib changes.
321 fib_node_type_t fib_node_type;
324 * API dynamically registered base ID.
328 volatile u32 *writer_lock;
331 extern lb_main_t lb_main;
332 extern vlib_node_registration_t lb6_node;
333 extern vlib_node_registration_t lb4_node;
336 * Fix global load-balancer parameters.
337 * @param ip4_address IPv4 source address used for encapsulated traffic
338 * @param ip6_address IPv6 source address used for encapsulated traffic
339 * @return 0 on success. VNET_LB_ERR_XXX on error
341 int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address,
342 u32 sticky_buckets, u32 flow_timeout);
344 int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type, u8 dscp,
345 u32 new_length, u32 *vip_index);
346 int lb_vip_del(u32 vip_index);
348 int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index);
350 #define lb_vip_get_by_index(index) (pool_is_free_index(lb_main.vips, index)?NULL:pool_elt_at_index(lb_main.vips, index))
352 int lb_vip_add_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
353 int lb_vip_del_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
355 u32 lb_hash_time_now(vlib_main_t * vm);
357 void lb_garbage_collection();
359 format_function_t format_lb_main;
361 #endif /* LB_PLUGIN_LB_LB_H_ */