/* * 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. */ /** * lb-plugin implements a MagLev-like load balancer. * http://research.google.com/pubs/pub44824.html * * It hasn't been tested for interoperability with the original MagLev * but intends to provide similar functionality. * The load-balancer receives traffic destined to VIP (Virtual IP) * addresses from one or multiple(ECMP) routers. * The load-balancer tunnels the traffic toward many application servers * ensuring session stickyness (i.e. that a single sessions is tunneled * towards a single application server). * */ #ifndef LB_PLUGIN_LB_LB_H_ #define LB_PLUGIN_LB_LB_H_ #include <lb/util.h> #include <vnet/util/refcount.h> #include <vnet/vnet.h> #include <vnet/ip/ip.h> #include <vnet/dpo/dpo.h> #include <vnet/fib/fib_table.h> #include <lb/lbhash.h> #define LB_DEFAULT_PER_CPU_STICKY_BUCKETS 1 << 10 #define LB_DEFAULT_FLOW_TIMEOUT 40 typedef enum { LB_NEXT_DROP, LB_N_NEXT, } lb_next_t; /** * Each VIP is configured with a set of * application server. */ typedef struct { /** * Registration to FIB event. */ fib_node_t fib_node; /** * Destination address used to tunnel traffic towards * that application server. * The address is also used as ID and pseudo-random * seed for the load-balancing process. */ ip46_address_t address; /** * ASs are indexed by address and VIP Index. * Which means there will be duplicated if the same server * address is used for multiple VIPs. */ u32 vip_index; /** * Some per-AS flags. * For now only LB_AS_FLAGS_USED is defined. */ u8 flags; #define LB_AS_FLAGS_USED 0x1 /** * Rotating timestamp of when LB_AS_FLAGS_USED flag was last set. * * AS removal is based on garbage collection and reference counting. * When an AS is removed, there is a race between configuration core * and worker cores which may still add a reference while it should not * be used. This timestamp is used to not remove the AS while a race condition * may happen. */ u32 last_used; /** * The FIB entry index for the next-hop */ fib_node_index_t next_hop_fib_entry_index; /** * The child index on the FIB entry */ u32 next_hop_child_index; /** * The next DPO in the graph to follow. */ dpo_id_t dpo; } lb_as_t; format_function_t format_lb_as; typedef struct { u32 as_index; } lb_new_flow_entry_t; #define lb_foreach_vip_counter \ _(NEXT_PACKET, "packet from existing sessions", 0) \ _(FIRST_PACKET, "first session packet", 1) \ _(UNTRACKED_PACKET, "untracked packet", 2) \ _(NO_SERVER, "no server configured", 3) typedef enum { #define _(a,b,c) LB_VIP_COUNTER_##a = c, lb_foreach_vip_counter #undef _ LB_N_VIP_COUNTERS } lb_vip_counter_t; /** * The load balancer supports IPv4 and IPv6 traffic * and GRE4 and GRE6 encap. */ typedef enum { LB_VIP_TYPE_IP6_GRE6, LB_VIP_TYPE_IP6_GRE4, LB_VIP_TYPE_IP4_GRE6, LB_VIP_TYPE_IP4_GRE4, LB_VIP_N_TYPES, } lb_vip_type_t; format_function_t format_lb_vip_type; unformat_function_t unformat_lb_vip_type; /** * Load balancing service is provided per VIP. * In this data model, a VIP can be a whole prefix. * But load balancing only * occurs on a per-source-address/port basis. Meaning that if a given source * reuses the same port for multiple destinations within the same VIP, * they will be considered as a single flow. */ typedef struct { //Runtime /** * Vector mapping (flow-hash & new_connect_table_mask) to AS index. * This is used for new flows. */ lb_new_flow_entry_t *new_flow_table; /** * New flows table length - 1 * (length MUST be a power of 2) */ u32 new_flow_table_mask; /** * Last time garbage collection was run to free the ASs. */ u32 last_garbage_collection; //Not runtime /** * A Virtual IP represents a given service delivered * by a set of application servers. It can be a single * address or a prefix. * IPv4 prefixes are encoded using IPv4-in-IPv6 embedded address * (i.e. ::/96 prefix). */ ip46_address_t prefix; /** * The VIP prefix length. * In case of IPv4, plen = 96 + ip4_plen. */ u8 plen; /** * The type of traffic for this. * LB_TYPE_UNDEFINED if unknown. */ lb_vip_type_t type; /** * Flags related to this VIP. * LB_VIP_FLAGS_USED means the VIP is active. * When it is not set, the VIP in the process of being removed. * We cannot immediately remove a VIP because the VIP index still may be stored * in the adjacency index. */ u8 flags; #define LB_VIP_FLAGS_USED 0x1 /** * Pool of AS indexes used for this VIP. * This also includes ASs that have been removed (but are still referenced). */ u32 *as_indexes; } lb_vip_t; #define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 || (vip)->type == LB_VIP_TYPE_IP4_GRE4) #define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 || (vip)->type == LB_VIP_TYPE_IP4_GRE4) format_function_t format_lb_vip; format_function_t format_lb_vip_detailed; typedef struct { /** * Each CPU has its own sticky flow hash table. * One single table is used for all VIPs. */ lb_hash_t *sticky_ht; } lb_per_cpu_t; typedef struct { /** * Pool of all Virtual IPs */ lb_vip_t *vips; /** * Pool of ASs. * ASs are referenced by address and vip index. * The first element (index 0) is special and used only to fill * new_flow_tables when no AS has been configured. */ lb_as_t *ass; /** * Each AS has an associated reference counter. * As ass[0] has a special meaning, its associated counter * starts at 0 and is decremented instead. i.e. do not use it. */ vlib_refcount_t as_refcount; /** * Some global data is per-cpu */ lb_per_cpu_t *per_cpu; /** * Node next index for IP adjacencies, for each of the traffic types. */ u32 ip_lookup_next_index[LB_VIP_N_TYPES]; /** * Source address used in IPv6 encapsulated traffic */ ip6_address_t ip6_src_address; /** * Source address used for IPv4 encapsulated traffic */ ip4_address_t ip4_src_address; /** * Number of buckets in the per-cpu sticky hash table. */ u32 per_cpu_sticky_buckets; /** * Flow timeout in seconds. */ u32 flow_timeout; /** * Per VIP counter */ vlib_simple_counter_main_t vip_counters[LB_N_VIP_COUNTERS]; /** * DPO used to send packet from IP4/6 lookup to LB node. */ dpo_type_t dpo_gre4_type; dpo_type_t dpo_gre6_type; /** * Node type for registering to fib changes. */ fib_node_type_t fib_node_type; /** * API dynamically registered base ID. */ u16 msg_id_base; volatile u32 *writer_lock; } lb_main_t; extern lb_main_t lb_main; extern vlib_node_registration_t lb6_node; extern vlib_node_registration_t lb4_node; /** * Fix global load-balancer parameters. * @param ip4_address IPv4 source address used for encapsulated traffic * @param ip6_address IPv6 source address used for encapsulated traffic * @return 0 on success. VNET_LB_ERR_XXX on error */ int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address, u32 sticky_buckets, u32 flow_timeout); int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type, u32 new_length, u32 *vip_index); int lb_vip_del(u32 vip_index); int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index); #define lb_vip_get_by_index(index) (pool_is_free_index(lb_main.vips, index)?NULL:pool_elt_at_index(lb_main.vips, index)) int lb_vip_add_ass(u32 vip_index, ip46_address_t *addresses, u32 n); int lb_vip_del_ass(u32 vip_index, ip46_address_t *addresses, u32 n); u32 lb_hash_time_now(vlib_main_t * vm); void lb_garbage_collection(); format_function_t format_lb_main; #endif /* LB_PLUGIN_LB_LB_H_ */