diff options
Diffstat (limited to 'vnet/vnet/l2/l2_flood.c')
| -rw-r--r-- | vnet/vnet/l2/l2_flood.c | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/vnet/vnet/l2/l2_flood.c b/vnet/vnet/l2/l2_flood.c new file mode 100644 index 00000000000..8a702168715 --- /dev/null +++ b/vnet/vnet/l2/l2_flood.c @@ -0,0 +1,520 @@ +/* + * l2_flood.c : layer 2 flooding + * + * Copyright (c) 2013 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 <vlib/vlib.h> +#include <vnet/vnet.h> +#include <vnet/pg/pg.h> +#include <vnet/ethernet/ethernet.h> +#include <vlib/cli.h> +#include <vnet/l2/l2_input.h> +#include <vnet/l2/feat_bitmap.h> +#include <vnet/l2/l2_bvi.h> +#include <vnet/replication.h> +#include <vnet/l2/l2_fib.h> + +#include <vppinfra/error.h> +#include <vppinfra/hash.h> + + +/* + * Flooding uses the packet replication infrastructure to send a copy of the + * packet to each member interface. Logically the replication infrastructure + * expects two graph nodes: a prep node that initiates replication and sends the + * packet to the first destination, and a recycle node that is passed the packet + * after it has been transmitted. + * + * To decrease the amount of code, l2 flooding implements both functions in + * the same graph node. This node can tell if is it being called as the "prep" + * or "recycle" using replication_is_recycled(). + */ + + +typedef struct { + + // Next nodes for each feature + u32 feat_next_node_index[32]; + + // next node index for the L3 input node of each ethertype + next_by_ethertype_t l3_next; + + /* convenience variables */ + vlib_main_t * vlib_main; + vnet_main_t * vnet_main; +} l2flood_main_t; + +typedef struct { + u8 src[6]; + u8 dst[6]; + u32 sw_if_index; + u16 bd_index; +} l2flood_trace_t; + + +/* packet trace format function */ +static u8 * format_l2flood_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + l2flood_trace_t * t = va_arg (*args, l2flood_trace_t *); + + s = format (s, "l2-flood: sw_if_index %d dst %U src %U bd_index %d", + t->sw_if_index, + format_ethernet_address, t->dst, + format_ethernet_address, t->src, + t->bd_index); + return s; +} + +l2flood_main_t l2flood_main; + +static vlib_node_registration_t l2flood_node; + +#define foreach_l2flood_error \ +_(L2FLOOD, "L2 flood packets") \ +_(REPL_FAIL, "L2 replication failures") \ +_(NO_MEMBERS, "L2 replication complete") \ +_(BVI_TAGGED, "BVI packet with vlan tag") \ +_(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") + +typedef enum { +#define _(sym,str) L2FLOOD_ERROR_##sym, + foreach_l2flood_error +#undef _ + L2FLOOD_N_ERROR, +} l2flood_error_t; + +static char * l2flood_error_strings[] = { +#define _(sym,string) string, + foreach_l2flood_error +#undef _ +}; + +typedef enum { + L2FLOOD_NEXT_L2_OUTPUT, + L2FLOOD_NEXT_DROP, + L2FLOOD_N_NEXT, +} l2flood_next_t; + +/* + * Perform flooding on one packet + * + * Due to the way BVI processing can modify the packet, the BVI interface + * (if present) must be processed last in the replication. The member vector + * is arranged so that the BVI interface is always the first element. + * Flooding walks the vector in reverse. + * + * BVI processing causes the packet to go to L3 processing. This strips the + * L2 header, which is fine because the replication infrastructure restores + * it. However L3 processing can trigger larger changes to the packet. For + * example, an ARP request could be turned into an ARP reply, an ICMP request + * could be turned into an ICMP reply. If BVI processing is not performed + * last, the modified packet would be replicated to the remaining members. + */ + +static_always_inline void +l2flood_process (vlib_main_t * vm, + vlib_node_runtime_t * node, + l2flood_main_t * msm, + u64 * counter_base, + vlib_buffer_t * b0, + u32 sw_if_index0, + l2fib_entry_key_t * key0, + u32 * bucket0, + l2fib_entry_result_t * result0, + u32 * next0) +{ + u16 bd_index0; + l2_bridge_domain_t *bd_config; + l2_flood_member_t * members; + i32 current_member; // signed + replication_context_t * ctx; + u8 in_shg = vnet_buffer(b0)->l2.shg; + + if (!replication_is_recycled(b0)) { + + // Do flood "prep node" processing + + // Get config for the bridge domain interface + bd_index0 = vnet_buffer(b0)->l2.bd_index; + bd_config = vec_elt_at_index(l2input_main.bd_configs, bd_index0); + members = bd_config->members; + + // Find first member that passes the reflection and SHG checks + current_member = vec_len(members) - 1; + while ((current_member >= 0) && + ((members[current_member].sw_if_index == sw_if_index0) || + (in_shg && members[current_member].shg == in_shg))) { + current_member--; + } + + if (current_member < 0) { + // No members to flood to + *next0 = L2FLOOD_NEXT_DROP; + b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS]; + return; + } + + if ((current_member > 0) && + ((current_member > 1) || + ((members[0].sw_if_index != sw_if_index0) && + (!in_shg || members[0].shg != in_shg)))) { + // If more than one member then initiate replication + ctx = replication_prep (vm, b0, l2flood_node.index, 1 /* l2_packet */); + ctx->feature_replicas = (u64) members; + ctx->feature_counter = current_member; + } + + } else { + + // Do flood "recycle node" processing + + if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_REPL_FAIL)) + { + (void)replication_recycle (vm, b0, 1 /* is_last */); + *next0 = L2FLOOD_NEXT_DROP; + b0->error = node->errors[L2FLOOD_ERROR_REPL_FAIL]; + return; + } + + ctx = replication_get_ctx (b0); + replication_clear_recycled (b0); + + members = (l2_flood_member_t *) ctx->feature_replicas; + current_member = (i32)ctx->feature_counter - 1; + + // Find next member that passes the reflection and SHG check + while ((current_member >= 0) && + ((members[current_member].sw_if_index == sw_if_index0) || + (in_shg && members[current_member].shg == in_shg))) { + current_member--; + } + + if (current_member < 0) { + // No more members to flood to. + // Terminate replication and drop packet. + + replication_recycle (vm, b0, 1 /* is_last */); + + *next0 = L2FLOOD_NEXT_DROP; + // Ideally we woudn't bump a counter here, just silently complete + b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS]; + return; + } + + // Restore packet and context and continue replication + ctx->feature_counter = current_member; + replication_recycle (vm, b0, + ((current_member == 0) || /*is_last */ + ((current_member == 1) && + ((members[0].sw_if_index == sw_if_index0) || + (in_shg && members[0].shg == in_shg))))); + } + + // Forward packet to the current member + + if (PREDICT_TRUE(members[current_member].flags == L2_FLOOD_MEMBER_NORMAL)) { + // Do normal L2 forwarding + vnet_buffer(b0)->sw_if_index[VLIB_TX] = members[current_member].sw_if_index; + *next0 = L2FLOOD_NEXT_L2_OUTPUT; + + } else { + // Do BVI processing + u32 rc; + rc = l2_to_bvi (vm, + msm->vnet_main, + b0, + members[current_member].sw_if_index, + &msm->l3_next, + next0); + + if (PREDICT_FALSE(rc)) { + if (rc == TO_BVI_ERR_TAGGED) { + b0->error = node->errors[L2FLOOD_ERROR_BVI_TAGGED]; + *next0 = L2FLOOD_NEXT_DROP; + } else if (rc == TO_BVI_ERR_ETHERTYPE) { + b0->error = node->errors[L2FLOOD_ERROR_BVI_ETHERTYPE]; + *next0 = L2FLOOD_NEXT_DROP; + } + } + } + +} + + +static uword +l2flood_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + u32 n_left_from, * from, * to_next; + l2flood_next_t next_index; + l2flood_main_t * msm = &l2flood_main; + vlib_node_t *n = vlib_get_node (vm, l2flood_node.index); + u32 node_counter_base_index = n->error_heap_index; + vlib_error_main_t * em = &vm->error_main; + + from = vlib_frame_vector_args (frame); + n_left_from = frame->n_vectors; /* number of packets to process */ + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + u32 n_left_to_next; + + /* get space to enqueue frame to graph node "next_index" */ + vlib_get_next_frame (vm, node, next_index, + to_next, n_left_to_next); + + while (n_left_from >= 6 && n_left_to_next >= 2) + { + u32 bi0, bi1; + vlib_buffer_t * b0, * b1; + u32 next0, next1; + u32 sw_if_index0, sw_if_index1; + ethernet_header_t * h0, * h1; + l2fib_entry_key_t key0, key1; + l2fib_entry_result_t result0, result1; + u32 bucket0, bucket1; + + /* Prefetch next iteration. */ + { + vlib_buffer_t * p2, * p3, * p4, * p5; + + p2 = vlib_get_buffer (vm, from[2]); + p3 = vlib_get_buffer (vm, from[3]); + p4 = vlib_get_buffer (vm, from[4]); + p5 = vlib_get_buffer (vm, from[5]); + + // Prefetch the buffer header for the N+2 loop iteration + vlib_prefetch_buffer_header (p4, LOAD); + vlib_prefetch_buffer_header (p5, LOAD); + + // Prefetch the replication context for the N+1 loop iteration + // This depends on the buffer header above + replication_prefetch_ctx (p2); + replication_prefetch_ctx (p3); + + // Prefetch the packet for the N+1 loop iteration + CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE); + CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE); + } + + /* speculatively enqueue b0 and b1 to the current next frame */ + /* bi is "buffer index", b is pointer to the buffer */ + to_next[0] = bi0 = from[0]; + to_next[1] = bi1 = from[1]; + from += 2; + to_next += 2; + n_left_from -= 2; + n_left_to_next -= 2; + + b0 = vlib_get_buffer (vm, bi0); + b1 = vlib_get_buffer (vm, bi1); + + /* RX interface handles */ + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX]; + + /* Process 2 x pkts */ + + h0 = vlib_buffer_get_current (b0); + h1 = vlib_buffer_get_current (b1); + + /* process 2 pkts */ + em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 2; + + l2flood_process (vm, node, msm, &em->counters[node_counter_base_index], + b0, sw_if_index0, &key0, &bucket0, &result0, &next0); + + l2flood_process (vm, node, msm, &em->counters[node_counter_base_index], + b1, sw_if_index1, &key1, &bucket1, &result1, &next1); + + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE))) + { + if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) + { + l2flood_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->bd_index = vnet_buffer(b0)->l2.bd_index; + memcpy(t->src, h0->src_address, 6); + memcpy(t->dst, h0->dst_address, 6); + } + if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED)) + { + l2flood_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t)); + t->sw_if_index = sw_if_index1; + t->bd_index = vnet_buffer(b1)->l2.bd_index; + memcpy(t->src, h1->src_address, 6); + memcpy(t->dst, h1->dst_address, 6); + } + } + + /* verify speculative enqueues, maybe switch current next frame */ + /* if next0==next1==next_index then nothing special needs to be done */ + vlib_validate_buffer_enqueue_x2 (vm, node, next_index, + to_next, n_left_to_next, + bi0, bi1, next0, next1); + } + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t * b0; + u32 next0; + u32 sw_if_index0; + ethernet_header_t * h0; + l2fib_entry_key_t key0; + l2fib_entry_result_t result0; + u32 bucket0; + + /* speculatively enqueue b0 to the current next frame */ + bi0 = from[0]; + to_next[0] = bi0; + from += 1; + to_next += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + b0 = vlib_get_buffer (vm, bi0); + + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + + h0 = vlib_buffer_get_current (b0); + + /* process 1 pkt */ + em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 1; + + l2flood_process (vm, node, msm, &em->counters[node_counter_base_index], + b0, sw_if_index0, &key0, &bucket0, &result0, &next0); + + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) && + (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + l2flood_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->bd_index = vnet_buffer(b0)->l2.bd_index; + memcpy(t->src, h0->src_address, 6); + memcpy(t->dst, h0->dst_address, 6); + } + + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + + return frame->n_vectors; +} + + +VLIB_REGISTER_NODE (l2flood_node,static) = { + .function = l2flood_node_fn, + .name = "l2-flood", + .vector_size = sizeof (u32), + .format_trace = format_l2flood_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + + .n_errors = ARRAY_LEN(l2flood_error_strings), + .error_strings = l2flood_error_strings, + + .n_next_nodes = L2FLOOD_N_NEXT, + + /* edit / add dispositions here */ + .next_nodes = { + [L2FLOOD_NEXT_L2_OUTPUT] = "l2-output", + [L2FLOOD_NEXT_DROP] = "error-drop", + }, +}; + +clib_error_t *l2flood_init (vlib_main_t *vm) +{ + l2flood_main_t * mp = &l2flood_main; + + mp->vlib_main = vm; + mp->vnet_main = vnet_get_main(); + + // Initialize the feature next-node indexes + feat_bitmap_init_next_nodes(vm, + l2flood_node.index, + L2INPUT_N_FEAT, + l2input_get_feat_names(), + mp->feat_next_node_index); + + return 0; +} + +VLIB_INIT_FUNCTION (l2flood_init); + + + +// Add the L3 input node for this ethertype to the next nodes structure +void +l2flood_register_input_type (vlib_main_t * vm, + ethernet_type_t type, + u32 node_index) +{ + l2flood_main_t * mp = &l2flood_main; + u32 next_index; + + next_index = vlib_node_add_next (vm, + l2flood_node.index, + node_index); + + next_by_ethertype_register (&mp->l3_next, type, next_index); +} + + +// set subinterface flood enable/disable +// The CLI format is: +// set interface l2 flood <interface> [disable] +static clib_error_t * +int_flood (vlib_main_t * vm, + unformat_input_t * input, + vlib_cli_command_t * cmd) +{ + vnet_main_t * vnm = vnet_get_main(); + clib_error_t * error = 0; + u32 sw_if_index; + u32 enable; + + if (! unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index)) + { + error = clib_error_return (0, "unknown interface `%U'", + format_unformat_error, input); + goto done; + } + + enable = 1; + if (unformat (input, "disable")) { + enable = 0; + } + + // set the interface flag + l2input_intf_bitmap_enable(sw_if_index, L2INPUT_FEAT_FLOOD, enable); + + done: + return error; +} + +VLIB_CLI_COMMAND (int_flood_cli, static) = { + .path = "set interface l2 flood", + .short_help = "set interface l2 flood <interface> [disable]", + .function = int_flood, +}; 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