/* * 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 #include #include #include #include #include #include #include #include #include #include #include /* * 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 = (uword) members; ctx->feature_counter = current_member; } } else { vnet_buffer_opaque_t *vnet_buff_op; // 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 *)(intptr_t) ctx->feature_replicas; current_member = (i32)ctx->feature_counter - 1; // Need to update input index from saved packet context vnet_buff_op = (vnet_buffer_opaque_t *)ctx->vnet_buffer; *sw_if_index0 = vnet_buff_op->sw_if_index[VLIB_RX]; // 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; 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 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)); ethernet_header_t * h0 = vlib_buffer_get_current (b0); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer(b0)->l2.bd_index; clib_memcpy(t->src, h0->src_address, 6); clib_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)); ethernet_header_t * h1 = vlib_buffer_get_current (b1); t->sw_if_index = sw_if_index1; t->bd_index = vnet_buffer(b1)->l2.bd_index; clib_memcpy(t->src, h1->src_address, 6); clib_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; 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]; /* 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)); ethernet_header_t * h0 = vlib_buffer_get_current (b0); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer(b0)->l2.bd_index; clib_memcpy(t->src, h0->src_address, 6); clib_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 [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 [disable]", .function = int_flood, };