/* * 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 <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; /* convenience variables */ vlib_main_t *vlib_main; vnet_main_t *vnet_main; } l2fwd_main_t; typedef struct { /* per-pkt trace data */ u8 src[6]; u8 dst[6]; u32 sw_if_index; u16 bd_index; } 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", t->sw_if_index, format_ethernet_address, t->dst, format_ethernet_address, t->src, t->bd_index); return s; } l2fwd_main_t l2fwd_main; static 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_FLOOD, 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, u32 * 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 (!result0->fields.age_not) { l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn }; l2fib_seq_num_t expected_sn = { .bd = in_sn.bd, .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index), }; l2fib_seq_num_valid = expected_sn.as_u16 == result0->fields.sn.as_u16; } 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 (result0->fields.filter)) { b0->error = node->errors[L2FWD_ERROR_FILTER_DROP]; *next0 = L2FWD_NEXT_DROP; } /* perform BVI check */ else if (PREDICT_FALSE (result0->fields.bvi)) { 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 * TODO:replicate packet to each intf in bridge-domain * For now just drop */ if (vnet_buffer (b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD) { *next0 = L2FWD_NEXT_FLOOD; } 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, *from, *to_next; l2fwd_next_t next_index; 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; /* 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_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 >= 8 && n_left_to_next >= 4) { u32 bi0, bi1, bi2, bi3; vlib_buffer_t *b0, *b1, *b2, *b3; u32 next0, next1, next2, next3; u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3; ethernet_header_t *h0, *h1, *h2, *h3; l2fib_entry_key_t key0, key1, key2, key3; l2fib_entry_result_t result0, result1, result2, result3; u32 bucket0, bucket1, bucket2, bucket3; /* Prefetch next iteration. */ { vlib_buffer_t *p4, *p5, *p6, *p7; p4 = vlib_get_buffer (vm, from[4]); p5 = vlib_get_buffer (vm, from[5]); p6 = vlib_get_buffer (vm, from[6]); p7 = vlib_get_buffer (vm, from[7]); vlib_prefetch_buffer_header (p4, LOAD); vlib_prefetch_buffer_header (p5, LOAD); vlib_prefetch_buffer_header (p6, LOAD); vlib_prefetch_buffer_header (p7, LOAD); CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE); CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE); CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE); CLIB_PREFETCH (p7->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]; to_next[2] = bi2 = from[2]; to_next[3] = bi3 = from[3]; from += 4; to_next += 4; n_left_from -= 4; n_left_to_next -= 4; b0 = vlib_get_buffer (vm, bi0); b1 = vlib_get_buffer (vm, bi1); b2 = vlib_get_buffer (vm, bi2); b3 = vlib_get_buffer (vm, bi3); /* 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]; sw_if_index2 = vnet_buffer (b2)->sw_if_index[VLIB_RX]; sw_if_index3 = vnet_buffer (b3)->sw_if_index[VLIB_RX]; h0 = vlib_buffer_get_current (b0); h1 = vlib_buffer_get_current (b1); h2 = vlib_buffer_get_current (b2); h3 = vlib_buffer_get_current (b3); if (do_trace) { if (b0->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_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; clib_memcpy (t->src, h0->src_address, 6); clib_memcpy (t->dst, h0->dst_address, 6); } if (b1->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_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; clib_memcpy (t->src, h1->src_address, 6); clib_memcpy (t->dst, h1->dst_address, 6); } if (b2->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b2, sizeof (*t)); t->sw_if_index = sw_if_index2; t->bd_index = vnet_buffer (b2)->l2.bd_index; clib_memcpy (t->src, h2->src_address, 6); clib_memcpy (t->dst, h2->dst_address, 6); } if (b3->flags & VLIB_BUFFER_IS_TRACED) { l2fwd_trace_t *t = vlib_add_trace (vm, node, b3, sizeof (*t)); t->sw_if_index = sw_if_index3; t->bd_index = vnet_buffer (b3)->l2.bd_index; clib_memcpy (t->src, h3->src_address, 6); clib_memcpy (t->dst, h3->dst_address, 6); } } /* process 2 pkts */ #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 (b0)->l2.bd_index, vnet_buffer (b1)->l2.bd_index, vnet_buffer (b2)->l2.bd_index, vnet_buffer (b3)->l2.bd_index, &key0, /* not used */ &key1, /* not used */ &key2, /* not used */ &key3, /* not used */ &bucket0, /* not used */ &bucket1, /* not used */ &bucket2, /* not used */ &bucket3, /* not used */ &result0, &result1, &result2, &result3); /* *INDENT-ON* */ l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0, &next0); l2fwd_process (vm, node, msm, em, b1, sw_if_index1, &result1, &next1); l2fwd_process (vm, node, msm, em, b2, sw_if_index2, &result2, &next2); l2fwd_process (vm, node, msm, em, b3, sw_if_index3, &result3, &next3); /* verify speculative enqueues, maybe switch current next frame */ /* if next0==next1==next_index then nothing special needs to be done */ vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next, n_left_to_next, bi0, bi1, bi2, bi3, next0, next1, next2, next3); } 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); if (do_trace && PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { l2fwd_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; clib_memcpy (t->src, h0->src_address, 6); clib_memcpy (t->dst, h0->dst_address, 6); } /* 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 (b0)->l2.bd_index, &key0, /* not used */ &bucket0, /* not used */ &result0); l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0, &next0); /* 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; } static uword l2fwd_node_fn (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,static) = { .function = l2fwd_node_fn, .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_FLOOD] = "l2-flood", [L2FWD_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ VLIB_NODE_FUNCTION_MULTIARCH (l2fwd_node, l2fwd_node_fn) 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 (); /* 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)->xconnect) { 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 fowarding: * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0} * Example of how to disable fowarding: * @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* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */