/* * l2_fwd.c : layer 2 forwarding using l2fib * * 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/l2_bvi.h> #include <vnet/l2/l2_fwd.h> #include <vnet/l2/l2_fib.h> #include <vnet/l2/feat_bitmap.h> #include <vppinfra/error.h> #include <vppinfra/hash.h> #include <vppinfra/sparse_vec.h> /** * @file * @brief Ethernet Forwarding. * * Code in this file handles forwarding Layer 2 packets. This file calls * the FIB lookup, packet learning and the packet flooding as necessary. * Packet is then sent to the next graph node. */ typedef struct { /* Hash table */ BVT (clib_bihash) * mac_table; /* next node index for the L3 input node of each ethertype */ next_by_ethertype_t l3_next; /* Next nodes for each feature */ u32 feat_next_node_index[32]; /* convenience variables */ vlib_main_t *vlib_main; vnet_main_t *vnet_main; } l2fwd_main_t; typedef struct { /* per-pkt trace data */ u8 dst_and_src[12]; u32 sw_if_index; u16 bd_index; l2fib_entry_result_t result; } l2fwd_trace_t; /* packet trace format function */ static u8 * format_l2fwd_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 *); l2fwd_trace_t *t = va_arg (*args, l2fwd_trace_t *); s = format (s, "l2-fwd: sw_if_index %d dst %U src %U bd_index %d result [0x%llx, %d] %U", t->sw_if_index, format_ethernet_address, t->dst_and_src, format_ethernet_address, t->dst_and_src + 6, t->bd_index, t->result.raw, t->result.fields.sw_if_index, format_l2fib_entry_result_flags, t->result.fields.flags); return s; } #ifndef CLIB_MARCH_VARIANT l2fwd_main_t l2fwd_main; #else extern l2fwd_main_t l2fwd_main; #endif extern vlib_node_registration_t l2fwd_node; #define foreach_l2fwd_error \ _(L2FWD, "L2 forward packets") \ _(FLOOD, "L2 forward misses") \ _(HIT, "L2 forward hits") \ _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \ _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \ _(FILTER_DROP, "Filter Mac Drop") \ _(REFLECT_DROP, "Reflection Drop") \ _(STALE_DROP, "Stale entry Drop") typedef enum { #define _(sym,str) L2FWD_ERROR_##sym, foreach_l2fwd_error #undef _ L2FWD_N_ERROR, } l2fwd_error_t; static char *l2fwd_error_strings[] = { #define _(sym,string) string, foreach_l2fwd_error #undef _ }; typedef enum { L2FWD_NEXT_L2_OUTPUT, L2FWD_NEXT_DROP, L2FWD_N_NEXT, } l2fwd_next_t; /** Forward one packet based on the mac table lookup result. */ static_always_inline void l2fwd_process (vlib_main_t * vm, vlib_node_runtime_t * node, l2fwd_main_t * msm, vlib_error_main_t * em, vlib_buffer_t * b0, u32 sw_if_index0, l2fib_entry_result_t * result0, u16 * next0) { int try_flood = result0->raw == ~0; int flood_error; if (PREDICT_FALSE (try_flood)) { flood_error = L2FWD_ERROR_FLOOD; } else { /* lookup hit, forward packet */ #ifdef COUNTERS em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1; #endif vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index; *next0 = L2FWD_NEXT_L2_OUTPUT; int l2fib_seq_num_valid = 1; /* check l2fib seq num for stale entries */ if (!l2fib_entry_result_is_set_AGE_NOT (result0)) { l2fib_seq_num_t in_sn = vnet_buffer (b0)->l2.l2fib_sn; l2fib_seq_num_t expected_sn = l2_fib_update_seq_num (in_sn, l2_input_seq_num (result0->fields.sw_if_index)); l2fib_seq_num_valid = expected_sn == result0->fields.sn; } if (PREDICT_FALSE (!l2fib_seq_num_valid)) { flood_error = L2FWD_ERROR_STALE_DROP; try_flood = 1; } /* perform reflection check */ else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index)) { b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP]; *next0 = L2FWD_NEXT_DROP; } /* perform filter check */ else if (PREDICT_FALSE (l2fib_entry_result_is_set_FILTER (result0))) { b0->error = node->errors[L2FWD_ERROR_FILTER_DROP]; *next0 = L2FWD_NEXT_DROP; } /* perform BVI check */ else if (PREDICT_FALSE (l2fib_entry_result_is_set_BVI (result0))) { u32 rc; rc = l2_to_bvi (vm, msm->vnet_main, b0, vnet_buffer (b0)->sw_if_index[VLIB_TX], &msm->l3_next, next0); if (PREDICT_FALSE (rc)) { if (rc == TO_BVI_ERR_BAD_MAC) { b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC]; *next0 = L2FWD_NEXT_DROP; } else if (rc == TO_BVI_ERR_ETHERTYPE) { b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE]; *next0 = L2FWD_NEXT_DROP; } } } } /* flood */ if (PREDICT_FALSE (try_flood)) { /* * lookup miss, so flood which is typically the next feature * unless some other feature is inserted before uu_flood */ if (vnet_buffer (b0)->l2.feature_bitmap & (L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_UU_FWD)) { *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index, L2INPUT_FEAT_FWD); } else { /* Flooding is disabled */ b0->error = node->errors[flood_error]; *next0 = L2FWD_NEXT_DROP; } } } static_always_inline uword l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, int do_trace) { u32 n_left, *from; l2fwd_main_t *msm = &l2fwd_main; vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index); CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index; vlib_error_main_t *em = &vm->error_main; l2fib_entry_key_t cached_key; l2fib_entry_result_t cached_result; vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b; u16 nexts[VLIB_FRAME_SIZE], *next; /* Clear the one-entry cache in case mac table was updated */ cached_key.raw = ~0; cached_result.raw = ~0; from = vlib_frame_vector_args (frame); n_left = frame->n_vectors; /* number of packets to process */ vlib_get_buffers (vm, from, bufs, n_left); next = nexts; b = bufs; while (n_left >= 8) { u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3; const ethernet_header_t *h0, *h1, *h2, *h3; l2fib_entry_key_t key0, key1, key2, key3; l2fib_entry_result_t result0, result1, result2, result3; /* Prefetch next iteration. */ { vlib_prefetch_buffer_header (b[4], LOAD); vlib_prefetch_buffer_header (b[5], LOAD); vlib_prefetch_buffer_header (b[6], LOAD); vlib_prefetch_buffer_header (b[7], LOAD); clib_prefetch_load (b[4]->data); clib_prefetch_load (b[5]->data); clib_prefetch_load (b[6]->data); clib_prefetch_load (b[7]->data); } /* RX interface handles */ sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX]; sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_RX]; sw_if_index2 = vnet_buffer (b[2])->sw_if_index[VLIB_RX]; sw_if_index3 = vnet_buffer (b[3])->sw_if_index[VLIB_RX]; h0 = vlib_buffer_get_current (b[0]); h1 = vlib_buffer_get_current (b[1]); h2 = vlib_buffer_get_current (b[2]); h3 = vlib_buffer_get_current (b[3]); #ifdef COUNTERS em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4; #endif /* *INDENT-OFF* */ l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, h1->dst_address, h2->dst_address, h3->dst_address, vnet_buffer (b[0])->l2.bd_index, vnet_buffer (b[1])->l2.bd_index, vnet_buffer (b[2])->l2.bd_index, vnet_buffer (b[3])->l2.bd_index, &key0, /* not used */ &key1, /* not used */ &key2, /* not used */ &key3, /* not used */ &result0, &result1, &result2, &result3); /* *INDENT-ON* */ l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next); l2fwd_process (vm, node, msm, em, b[1], sw_if_index1, &result1, next + 1); l2fwd_process (vm, node, msm, em, b[2], sw_if_index2, &result2, next + 2); l2fwd_process (vm, node, msm, em, b[3], sw_if_index3, &result3, next + 3); /* verify speculative enqueues, maybe switch current next frame */ /* if next0==next1==next_index then nothing special needs to be done */ if (do_trace) { if (b[0]->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t)); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer (b[0])->l2.bd_index; clib_memcpy_fast (t->dst_and_src, h0->dst_address, sizeof (h0->dst_address) + sizeof (h0->src_address)); t->result = result0; } if (b[1]->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t)); t->sw_if_index = sw_if_index1; t->bd_index = vnet_buffer (b[1])->l2.bd_index; clib_memcpy_fast (t->dst_and_src, h1->dst_address, sizeof (h1->dst_address) + sizeof (h1->src_address)); t->result = result1; } if (b[2]->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t)); t->sw_if_index = sw_if_index2; t->bd_index = vnet_buffer (b[2])->l2.bd_index; clib_memcpy_fast (t->dst_and_src, h2->dst_address, sizeof (h2->dst_address) + sizeof (h2->src_address)); t->result = result2; } if (b[3]->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t)); t->sw_if_index = sw_if_index3; t->bd_index = vnet_buffer (b[3])->l2.bd_index; clib_memcpy_fast (t->dst_and_src, h3->dst_address, sizeof (h3->dst_address) + sizeof (h3->src_address)); t->result = result3; } } next += 4; b += 4; n_left -= 4; } while (n_left > 0) { u32 sw_if_index0; ethernet_header_t *h0; l2fib_entry_key_t key0; l2fib_entry_result_t result0; sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX]; h0 = vlib_buffer_get_current (b[0]); /* process 1 pkt */ #ifdef COUNTERS em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1; #endif l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, vnet_buffer (b[0])->l2.bd_index, &key0, /* not used */ &result0); l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next); if (do_trace && PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED)) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t)); t->sw_if_index = sw_if_index0; t->bd_index = vnet_buffer (b[0])->l2.bd_index; clib_memcpy_fast (t->dst_and_src, h0->dst_address, sizeof (h0->dst_address) + sizeof (h0->src_address)); t->result = result0; } /* verify speculative enqueue, maybe switch current next frame */ next += 1; b += 1; n_left -= 1; } vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors); return frame->n_vectors; } VLIB_NODE_FN (l2fwd_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE))) return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ ); return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (l2fwd_node) = { .name = "l2-fwd", .vector_size = sizeof (u32), .format_trace = format_l2fwd_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(l2fwd_error_strings), .error_strings = l2fwd_error_strings, .n_next_nodes = L2FWD_N_NEXT, /* edit / add dispositions here */ .next_nodes = { [L2FWD_NEXT_L2_OUTPUT] = "l2-output", [L2FWD_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ #ifndef CLIB_MARCH_VARIANT clib_error_t * l2fwd_init (vlib_main_t * vm) { l2fwd_main_t *mp = &l2fwd_main; mp->vlib_main = vm; mp->vnet_main = vnet_get_main (); /* Initialize the feature next-node indexes */ feat_bitmap_init_next_nodes (vm, l2fwd_node.index, L2INPUT_N_FEAT, l2input_get_feat_names (), mp->feat_next_node_index); /* init the hash table ptr */ mp->mac_table = get_mac_table (); /* Initialize the next nodes for each ethertype */ next_by_ethertype_init (&mp->l3_next); return 0; } VLIB_INIT_FUNCTION (l2fwd_init); /** Add the L3 input node for this ethertype to the next nodes structure. */ void l2fwd_register_input_type (vlib_main_t * vm, ethernet_type_t type, u32 node_index) { l2fwd_main_t *mp = &l2fwd_main; u32 next_index; next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index); next_by_ethertype_register (&mp->l3_next, type, next_index); } /** * Set subinterface forward enable/disable. * The CLI format is: * set interface l2 forward <interface> [disable] */ static clib_error_t * int_fwd (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 */ if (l2input_intf_config (sw_if_index)) { l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable); } else { l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable); } done: return error; } /*? * Layer 2 unicast forwarding can be enabled and disabled on each * interface and on each bridge-domain. Use this command to * manage interfaces. It is enabled by default. * * @cliexpar * Example of how to enable forwarding: * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0} * Example of how to disable forwarding: * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable} ?*/ /* *INDENT-OFF* */ VLIB_CLI_COMMAND (int_fwd_cli, static) = { .path = "set interface l2 forward", .short_help = "set interface l2 forward <interface> [disable]", .function = int_fwd, }; /* *INDENT-ON* */ #endif /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */