diff options
author | 2016-08-04 16:13:09 +0100 | |
---|---|---|
committer | 2016-08-11 14:05:40 +0000 | |
commit | 041eacc81656d2ed5bc01b96b15a7d03a1700f13 (patch) | |
tree | f1cded1a27f92bab90fec8e5ea9d991ee2ff7eb5 /plugins/lb-plugin/lb/node.c | |
parent | 3590ac5881261c95a3c575360e24903d60fac392 (diff) |
VPP-130: MagLev-like Load Balancer
This plugin provides load balancing for VPP in a way that is largely inspired
from Google's MagLev: http://research.google.com/pubs/pub44824.html
More info in the README.md
Change-Id: I1223f495d5c2d5200808a398504119f2830337e9
Signed-off-by: Pierre Pfister <ppfister@cisco.com>
Diffstat (limited to 'plugins/lb-plugin/lb/node.c')
-rw-r--r-- | plugins/lb-plugin/lb/node.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/plugins/lb-plugin/lb/node.c b/plugins/lb-plugin/lb/node.c new file mode 100644 index 00000000..4d598104 --- /dev/null +++ b/plugins/lb-plugin/lb/node.c @@ -0,0 +1,393 @@ +/* + * 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. + */ + +#include <lb/lb.h> + +#include <vnet/gre/packet.h> +#include <lb/lbhash.h> + +#define foreach_lb_error \ + _(NONE, "no error") \ + _(PROTO_NOT_SUPPORTED, "protocol not supported") \ + _(NO_SERVER, "no configured application server") + +typedef enum { +#define _(sym,str) LB_ERROR_##sym, + foreach_lb_error +#undef _ + LB_N_ERROR, +} lb_error_t; + +static char *lb_error_strings[] = { +#define _(sym,string) string, + foreach_lb_error +#undef _ +}; + +typedef enum { + LB_NEXT_LOOKUP, + LB_NEXT_DROP, + LB_N_NEXT, +} lb_next_t; + +typedef struct { + u32 vip_index; + u32 as_index; +} lb_trace_t; + +u8 *lb_format_adjacency(u8 * s, + struct ip_lookup_main_t * lm, + ip_adjacency_t *adj) +{ + lb_main_t *lbm = &lb_main; + lb_adj_data_t *ad = (lb_adj_data_t *) &adj->opaque; + __attribute__((unused)) lb_vip_t *vip = pool_elt_at_index (lbm->vips, ad->vip_index); + return format(s, "idx:%d", ad->vip_index); +} + +u8 * +format_lb_trace (u8 * s, va_list * args) +{ + lb_main_t *lbm = &lb_main; + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + lb_trace_t *t = va_arg (*args, lb_trace_t *); + s = format(s, "lb vip[%d]: %U\n", t->vip_index, format_lb_vip, &lbm->vips[t->vip_index]); + s = format(s, "lb as[%d]: %U\n", t->as_index, format_lb_as, &lbm->ass[t->as_index]); + return s; +} + +lb_hash_t *lb_get_sticky_table(u32 cpu_index) +{ + lb_main_t *lbm = &lb_main; + lb_hash_t *sticky_ht = lbm->per_cpu[cpu_index].sticky_ht; + //Check if size changed + if (PREDICT_FALSE(sticky_ht && (lbm->per_cpu_sticky_buckets != lb_hash_nbuckets(sticky_ht)))) { + + //Dereference everything in there + lb_hash_entry_t *e; + lb_hash_foreach_entry(sticky_ht, e) { + vlib_refcount_add(&lbm->as_refcount, cpu_index, e->value, -1); + vlib_refcount_add(&lbm->as_refcount, cpu_index, 0, -1); + } + + lb_hash_free(sticky_ht); + sticky_ht = NULL; + } + + //Create if necessary + if (PREDICT_FALSE(sticky_ht == NULL)) { + lbm->per_cpu[cpu_index].sticky_ht = lb_hash_alloc(lbm->per_cpu_sticky_buckets, lbm->flow_timeout); + sticky_ht = lbm->per_cpu[cpu_index].sticky_ht; + clib_warning("Regenerated sticky table %p", sticky_ht); + } + + ASSERT(sticky_ht); + + //Update timeout + sticky_ht->timeout = lbm->flow_timeout; + return sticky_ht; +} + +static_always_inline uword +lb_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame, + u8 is_input_v4, //Compile-time parameter stating that is input is v4 (or v6) + u8 is_encap_v4) //Compile-time parameter stating that is GRE encap is v4 (or v6) +{ + ip_lookup_main_t *lm = (is_input_v4)?&ip4_main.lookup_main:&ip6_main.lookup_main; + lb_main_t *lbm = &lb_main; + vlib_node_runtime_t *error_node = node; + u32 n_left_from, *from, next_index, *to_next, n_left_to_next; + u32 cpu_index = os_get_cpu_number(); + u32 lb_time = lb_hash_time_now(vm); + + lb_hash_t *sticky_ht = lb_get_sticky_table(cpu_index); + from = vlib_frame_vector_args (frame); + n_left_from = frame->n_vectors; + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 pi0; + vlib_buffer_t *p0; + ip_adjacency_t *adj0; + lb_adj_data_t *ad0; + lb_vip_t *vip0; + lb_as_t *as0; + gre_header_t *gre0; + u16 len0; + u32 value0, available_index0, hash0; + u64 key0[5]; + lb_error_t error0 = LB_ERROR_NONE; + lb_next_t next0 = LB_NEXT_LOOKUP; + + if (PREDICT_TRUE(n_left_from > 1)) + { + vlib_buffer_t *p2; + p2 = vlib_get_buffer(vm, from[1]); + vlib_prefetch_buffer_header(p2, STORE); + /* IPv4 + 8 = 28. possibly plus -40 */ + CLIB_PREFETCH (vlib_buffer_get_current(p2) - 40, 128, STORE); + } + + pi0 = to_next[0] = from[0]; + from += 1; + n_left_from -= 1; + to_next += 1; + n_left_to_next -= 1; + + p0 = vlib_get_buffer (vm, pi0); + adj0 = ip_get_adjacency (lm, vnet_buffer (p0)->ip.adj_index[VLIB_TX]); + ad0 = (lb_adj_data_t *) &adj0->opaque; + vip0 = pool_elt_at_index (lbm->vips, ad0->vip_index); + + if (is_input_v4) { + ip4_header_t *ip40; + ip40 = vlib_buffer_get_current (p0); + len0 = clib_net_to_host_u16(ip40->length); + key0[0] = (u64) ip40->src_address.as_u32; + key0[1] = (u64) ip40->dst_address.as_u32; + key0[2] = 0; + key0[3] = 0; + key0[4] = ((u64)((udp_header_t *)(ip40 + 1))->src_port << 32) | + ((u64)((udp_header_t *)(ip40 + 1))->dst_port << 16); + + hash0 = lb_hash_hash(key0); + } else { + ip6_header_t *ip60; + ip60 = vlib_buffer_get_current (p0); + len0 = clib_net_to_host_u16(ip60->payload_length) + sizeof(ip6_header_t); + key0[0] = ip60->src_address.as_u64[0]; + key0[1] = ip60->src_address.as_u64[1]; + key0[2] = ip60->dst_address.as_u64[0]; + key0[3] = ip60->dst_address.as_u64[1]; + key0[4] = ((u64)((udp_header_t *)(ip60 + 1))->src_port << 32) | + ((u64)((udp_header_t *)(ip60 + 1))->dst_port << 16); + + hash0 = lb_hash_hash(key0); + } + + //NOTE: This is an ugly trick to not include the VIP index in the hash calculation + //but actually use it in the key determination. + key0[4] |= ((vip0 - lbm->vips)); + + lb_hash_get(sticky_ht, key0, hash0, lb_time, &available_index0, &value0); + if (PREDICT_TRUE(value0 != ~0)) { + //Found an existing entry + as0 = &lbm->ass[value0]; + } else if (PREDICT_TRUE(available_index0 != ~0)) { + //There is an available slot for a new flow + as0 = &lbm->ass[vip0->new_flow_table[hash0 & vip0->new_flow_table_mask].as_index]; + if (PREDICT_FALSE(as0 == lbm->ass)) { //Special first element + error0 = LB_ERROR_NO_SERVER; + next0 = LB_NEXT_DROP; + } else { + vlib_increment_simple_counter(&lbm->vip_counters[LB_VIP_COUNTER_TRACKED_SESSION], + cpu_index, vip0 - lbm->vips, 1); + } + + //TODO: There are race conditions with as0 and vip0 manipulation. + //Configuration may be changed, vectors resized, etc... + + //Dereference previously used + vlib_refcount_add(&lbm->as_refcount, cpu_index, lb_hash_available_value(sticky_ht, available_index0), -1); + vlib_refcount_add(&lbm->as_refcount, cpu_index, as0 - lbm->ass, 1); + + //Add sticky entry + //Note that when there is no AS configured, an entry is configured anyway. + //But no configured AS is not something that should happen + lb_hash_put(sticky_ht, key0, as0 - lbm->ass, available_index0, lb_time); + } else { + //Could not store new entry in the table + as0 = &lbm->ass[vip0->new_flow_table[hash0 & vip0->new_flow_table_mask].as_index]; + vlib_increment_simple_counter(&lbm->vip_counters[LB_VIP_COUNTER_UNTRACKED_PACKET], + cpu_index, vip0 - lbm->vips, 1); + } + + //Now let's encap + if (is_encap_v4) { + ip4_header_t *ip40; + vlib_buffer_advance(p0, - sizeof(ip4_header_t) - sizeof(gre_header_t)); + ip40 = vlib_buffer_get_current(p0); + gre0 = (gre_header_t *)(ip40 + 1); + ip40->src_address = lbm->ip4_src_address; + ip40->dst_address = as0->address.ip4; + ip40->ip_version_and_header_length = 0x45; + ip40->ttl = 128; + ip40->length = clib_host_to_net_u16(len0 + sizeof(gre_header_t) + sizeof(ip4_header_t)); + ip40->protocol = IP_PROTOCOL_GRE; + ip40->checksum = ip4_header_checksum (ip40); + } else { + ip6_header_t *ip60; + vlib_buffer_advance(p0, - sizeof(ip6_header_t) - sizeof(gre_header_t)); + ip60 = vlib_buffer_get_current(p0); + gre0 = (gre_header_t *)(ip60 + 1); + ip60->dst_address = as0->address.ip6; + ip60->src_address = lbm->ip6_src_address; + ip60->hop_limit = 128; + ip60->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 (0x6<<28); + ip60->payload_length = clib_host_to_net_u16(len0 + sizeof(gre_header_t)); + ip60->protocol = IP_PROTOCOL_GRE; + } + + gre0->flags_and_version = 0; + gre0->protocol = (is_input_v4)? + clib_host_to_net_u16(0x0800): + clib_host_to_net_u16(0x86DD); + + if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED)) + { + lb_trace_t *tr = vlib_add_trace (vm, node, p0, sizeof (*tr)); + tr->as_index = as0 - lbm->ass; + tr->vip_index = ad0->vip_index; + } + + p0->error = error_node->errors[error0]; + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, pi0, next0); + } + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + + return frame->n_vectors; +} + +static uword +lb6_gre6_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + return lb_node_fn(vm, node, frame, 0, 0); +} + +static uword +lb6_gre4_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + return lb_node_fn(vm, node, frame, 0, 1); +} + +static uword +lb4_gre6_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + return lb_node_fn(vm, node, frame, 1, 0); +} + +static uword +lb4_gre4_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + return lb_node_fn(vm, node, frame, 1, 1); +} + +VLIB_REGISTER_NODE (lb6_gre6_node) = +{ + .function = lb6_gre6_node_fn, + .name = "lb6-gre6", + .vector_size = sizeof (u32), + .format_trace = format_lb_trace, + + .n_errors = LB_N_ERROR, + .error_strings = lb_error_strings, + + .n_next_nodes = LB_N_NEXT, + .next_nodes = + { + [LB_NEXT_LOOKUP] = "ip6-lookup", + [LB_NEXT_DROP] = "error-drop" + }, +}; + +VNET_IP6_REGISTER_ADJACENCY(lb6_gre6) = { + .node_name = "lb6-gre6", + .fn = lb_format_adjacency, + .next_index = &lb_main.ip_lookup_next_index[LB_VIP_TYPE_IP6_GRE6] +}; + +VLIB_REGISTER_NODE (lb6_gre4_node) = +{ + .function = lb6_gre4_node_fn, + .name = "lb6-gre4", + .vector_size = sizeof (u32), + .format_trace = format_lb_trace, + + .n_errors = LB_N_ERROR, + .error_strings = lb_error_strings, + + .n_next_nodes = LB_N_NEXT, + .next_nodes = + { + [LB_NEXT_LOOKUP] = "ip4-lookup", + [LB_NEXT_DROP] = "error-drop" + }, +}; + +VNET_IP6_REGISTER_ADJACENCY(lb6_gre4) = { + .node_name = "lb6-gre4", + .fn = lb_format_adjacency, + .next_index = &lb_main.ip_lookup_next_index[LB_VIP_TYPE_IP6_GRE4] +}; + +VLIB_REGISTER_NODE (lb4_gre6_node) = +{ + .function = lb4_gre6_node_fn, + .name = "lb4-gre6", + .vector_size = sizeof (u32), + .format_trace = format_lb_trace, + + .n_errors = LB_N_ERROR, + .error_strings = lb_error_strings, + + .n_next_nodes = LB_N_NEXT, + .next_nodes = + { + [LB_NEXT_LOOKUP] = "ip6-lookup", + [LB_NEXT_DROP] = "error-drop" + }, +}; + +VNET_IP4_REGISTER_ADJACENCY(lb4_gre6) = { + .node_name = "lb4-gre6", + .fn = lb_format_adjacency, + .next_index = &lb_main.ip_lookup_next_index[LB_VIP_TYPE_IP4_GRE6] +}; + +VLIB_REGISTER_NODE (lb4_gre4_node) = +{ + .function = lb4_gre4_node_fn, + .name = "lb4-gre4", + .vector_size = sizeof (u32), + .format_trace = format_lb_trace, + + .n_errors = LB_N_ERROR, + .error_strings = lb_error_strings, + + .n_next_nodes = LB_N_NEXT, + .next_nodes = + { + [LB_NEXT_LOOKUP] = "ip4-lookup", + [LB_NEXT_DROP] = "error-drop" + }, +}; + +VNET_IP4_REGISTER_ADJACENCY(lb4_gre4) = { + .node_name = "lb4-gre4", + .fn = lb_format_adjacency, + .next_index = &lb_main.ip_lookup_next_index[LB_VIP_TYPE_IP4_GRE4] +}; |