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 _(TRACKED_SESSION, "tracked session", 0) \
120 _(UNTRACKED_PACKET, "untracked packet", 1)
123 #define _(a,b,c) LB_VIP_COUNTER_##a = c,
124 lb_foreach_vip_counter
130 * The load balancer supports IPv4 and IPv6 traffic
131 * and GRE4 and GRE6 encap.
134 LB_VIP_TYPE_IP6_GRE6,
135 LB_VIP_TYPE_IP6_GRE4,
136 LB_VIP_TYPE_IP4_GRE6,
137 LB_VIP_TYPE_IP4_GRE4,
141 format_function_t format_lb_vip_type;
142 unformat_function_t unformat_lb_vip_type;
145 * Load balancing service is provided per VIP.
146 * In this data model, a VIP can be a whole prefix.
147 * But load balancing only
148 * occurs on a per-source-address/port basis. Meaning that if a given source
149 * reuses the same port for multiple destinations within the same VIP,
150 * they will be considered as a single flow.
157 * Vector mapping (flow-hash & new_connect_table_mask) to AS index.
158 * This is used for new flows.
160 lb_new_flow_entry_t *new_flow_table;
163 * New flows table length - 1
164 * (length MUST be a power of 2)
166 u32 new_flow_table_mask;
169 * Last time garbage collection was run to free the ASs.
171 u32 last_garbage_collection;
176 * A Virtual IP represents a given service delivered
177 * by a set of application servers. It can be a single
178 * address or a prefix.
179 * IPv4 prefixes are encoded using IPv4-in-IPv6 embedded address
180 * (i.e. ::/96 prefix).
182 ip46_address_t prefix;
185 * The VIP prefix length.
186 * In case of IPv4, plen = 96 + ip4_plen.
191 * The type of traffic for this.
192 * LB_TYPE_UNDEFINED if unknown.
197 * Flags related to this VIP.
198 * LB_VIP_FLAGS_USED means the VIP is active.
199 * When it is not set, the VIP in the process of being removed.
200 * We cannot immediately remove a VIP because the VIP index still may be stored
201 * in the adjacency index.
204 #define LB_VIP_FLAGS_USED 0x1
207 * Pool of AS indexes used for this VIP.
208 * This also includes ASs that have been removed (but are still referenced).
213 #define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
214 #define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
215 format_function_t format_lb_vip;
216 format_function_t format_lb_vip_detailed;
220 * Each CPU has its own sticky flow hash table.
221 * One single table is used for all VIPs.
223 lb_hash_t *sticky_ht;
228 * Pool of all Virtual IPs
234 * ASs are referenced by address and vip index.
235 * The first element (index 0) is special and used only to fill
236 * new_flow_tables when no AS has been configured.
241 * Each AS has an associated reference counter.
242 * As ass[0] has a special meaning, its associated counter
243 * starts at 0 and is decremented instead. i.e. do not use it.
245 vlib_refcount_t as_refcount;
248 * Some global data is per-cpu
250 lb_per_cpu_t *per_cpu;
253 * Node next index for IP adjacencies, for each of the traffic types.
255 u32 ip_lookup_next_index[LB_VIP_N_TYPES];
258 * Source address used in IPv6 encapsulated traffic
260 ip6_address_t ip6_src_address;
263 * Source address used for IPv4 encapsulated traffic
265 ip4_address_t ip4_src_address;
268 * Number of buckets in the per-cpu sticky hash table.
270 u32 per_cpu_sticky_buckets;
273 * Flow timeout in seconds.
280 vlib_simple_counter_main_t vip_counters[LB_N_VIP_COUNTERS];
283 * DPO used to send packet from IP4/6 lookup to LB node.
285 dpo_type_t dpo_gre4_type;
286 dpo_type_t dpo_gre6_type;
289 * Node type for registering to fib changes.
291 fib_node_type_t fib_node_type;
294 * API dynamically registered base ID.
298 volatile u32 *writer_lock;
301 extern lb_main_t lb_main;
302 extern vlib_node_registration_t lb6_node;
303 extern vlib_node_registration_t lb4_node;
306 * Fix global load-balancer parameters.
307 * @param ip4_address IPv4 source address used for encapsulated traffic
308 * @param ip6_address IPv6 source address used for encapsulated traffic
309 * @return 0 on success. VNET_LB_ERR_XXX on error
311 int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address,
312 u32 sticky_buckets, u32 flow_timeout);
314 int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type,
315 u32 new_length, u32 *vip_index);
316 int lb_vip_del(u32 vip_index);
318 int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index);
320 #define lb_vip_get_by_index(index) (pool_is_free_index(lb_main.vips, index)?NULL:pool_elt_at_index(lb_main.vips, index))
322 int lb_vip_add_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
323 int lb_vip_del_ass(u32 vip_index, ip46_address_t *addresses, u32 n);
325 u32 lb_hash_time_now(vlib_main_t * vm);
327 void lb_garbage_collection();
329 format_function_t format_lb_main;
331 #endif /* LB_PLUGIN_LB_LB_H_ */