2 * l2_fwd.c : layer 2 forwarding using l2fib
4 * Copyright (c) 2013 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include <vlib/vlib.h>
19 #include <vnet/vnet.h>
20 #include <vnet/pg/pg.h>
21 #include <vnet/ethernet/ethernet.h>
24 #include <vnet/l2/l2_input.h>
25 #include <vnet/l2/l2_bvi.h>
26 #include <vnet/l2/l2_fwd.h>
27 #include <vnet/l2/l2_fib.h>
28 #include <vnet/l2/feat_bitmap.h>
30 #include <vppinfra/error.h>
31 #include <vppinfra/hash.h>
32 #include <vppinfra/sparse_vec.h>
37 * @brief Ethernet Forwarding.
39 * Code in this file handles forwarding Layer 2 packets. This file calls
40 * the FIB lookup, packet learning and the packet flooding as necessary.
41 * Packet is then sent to the next graph node.
48 BVT (clib_bihash) * mac_table;
50 /* next node index for the L3 input node of each ethertype */
51 next_by_ethertype_t l3_next;
53 /* Next nodes for each feature */
54 u32 feat_next_node_index[32];
56 /* convenience variables */
57 vlib_main_t *vlib_main;
58 vnet_main_t *vnet_main;
63 /* per-pkt trace data */
68 l2fib_entry_result_t result;
71 /* packet trace format function */
73 format_l2fwd_trace (u8 * s, va_list * args)
75 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
76 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
77 l2fwd_trace_t *t = va_arg (*args, l2fwd_trace_t *);
81 "l2-fwd: sw_if_index %d dst %U src %U bd_index %d result [0x%llx, %d] %U",
82 t->sw_if_index, format_ethernet_address, t->dst,
83 format_ethernet_address, t->src, t->bd_index, t->result.raw,
84 t->result.fields.sw_if_index, format_l2fib_entry_result_flags,
85 t->result.fields.flags);
89 #ifndef CLIB_MARCH_VARIANT
90 l2fwd_main_t l2fwd_main;
92 extern l2fwd_main_t l2fwd_main;
95 extern vlib_node_registration_t l2fwd_node;
97 #define foreach_l2fwd_error \
98 _(L2FWD, "L2 forward packets") \
99 _(FLOOD, "L2 forward misses") \
100 _(HIT, "L2 forward hits") \
101 _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \
102 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
103 _(FILTER_DROP, "Filter Mac Drop") \
104 _(REFLECT_DROP, "Reflection Drop") \
105 _(STALE_DROP, "Stale entry Drop")
109 #define _(sym,str) L2FWD_ERROR_##sym,
115 static char *l2fwd_error_strings[] = {
116 #define _(sym,string) string,
123 L2FWD_NEXT_L2_OUTPUT,
128 /** Forward one packet based on the mac table lookup result. */
130 static_always_inline void
131 l2fwd_process (vlib_main_t * vm,
132 vlib_node_runtime_t * node,
134 vlib_error_main_t * em,
136 u32 sw_if_index0, l2fib_entry_result_t * result0, u16 * next0)
138 int try_flood = result0->raw == ~0;
141 if (PREDICT_FALSE (try_flood))
143 flood_error = L2FWD_ERROR_FLOOD;
147 /* lookup hit, forward packet */
149 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
152 vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
153 *next0 = L2FWD_NEXT_L2_OUTPUT;
154 int l2fib_seq_num_valid = 1;
156 /* check l2fib seq num for stale entries */
157 if (!l2fib_entry_result_is_set_AGE_NOT (result0))
159 l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn };
160 l2fib_seq_num_t expected_sn = {
162 .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index),
164 l2fib_seq_num_valid =
165 expected_sn.as_u16 == result0->fields.sn.as_u16;
168 if (PREDICT_FALSE (!l2fib_seq_num_valid))
170 flood_error = L2FWD_ERROR_STALE_DROP;
173 /* perform reflection check */
174 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
176 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
177 *next0 = L2FWD_NEXT_DROP;
179 /* perform filter check */
180 else if (PREDICT_FALSE (l2fib_entry_result_is_set_FILTER (result0)))
182 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
183 *next0 = L2FWD_NEXT_DROP;
185 /* perform BVI check */
186 else if (PREDICT_FALSE (l2fib_entry_result_is_set_BVI (result0)))
192 vnet_buffer (b0)->sw_if_index[VLIB_TX],
193 &msm->l3_next, next0);
195 if (PREDICT_FALSE (rc))
197 if (rc == TO_BVI_ERR_BAD_MAC)
199 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
200 *next0 = L2FWD_NEXT_DROP;
202 else if (rc == TO_BVI_ERR_ETHERTYPE)
204 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
205 *next0 = L2FWD_NEXT_DROP;
212 if (PREDICT_FALSE (try_flood))
215 * lookup miss, so flood which is typically the next feature
216 * unless some other feature is inserted before uu_flood
218 if (vnet_buffer (b0)->l2.feature_bitmap &
219 (L2INPUT_FEAT_UU_FLOOD |
220 L2INPUT_FEAT_UU_FWD | L2INPUT_FEAT_GBP_FWD))
222 *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
227 /* Flooding is disabled */
228 b0->error = node->errors[flood_error];
229 *next0 = L2FWD_NEXT_DROP;
235 static_always_inline uword
236 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
237 vlib_frame_t * frame, int do_trace)
240 l2fwd_main_t *msm = &l2fwd_main;
241 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
242 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
243 vlib_error_main_t *em = &vm->error_main;
244 l2fib_entry_key_t cached_key;
245 l2fib_entry_result_t cached_result;
246 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
247 u16 nexts[VLIB_FRAME_SIZE], *next;
249 /* Clear the one-entry cache in case mac table was updated */
251 cached_result.raw = ~0;
253 from = vlib_frame_vector_args (frame);
254 n_left = frame->n_vectors; /* number of packets to process */
255 vlib_get_buffers (vm, from, bufs, n_left);
261 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
262 const ethernet_header_t *h0, *h1, *h2, *h3;
263 l2fib_entry_key_t key0, key1, key2, key3;
264 l2fib_entry_result_t result0, result1, result2, result3;
266 /* Prefetch next iteration. */
268 vlib_prefetch_buffer_header (b[4], LOAD);
269 vlib_prefetch_buffer_header (b[5], LOAD);
270 vlib_prefetch_buffer_header (b[6], LOAD);
271 vlib_prefetch_buffer_header (b[7], LOAD);
273 CLIB_PREFETCH (b[4]->data, CLIB_CACHE_LINE_BYTES, LOAD);
274 CLIB_PREFETCH (b[5]->data, CLIB_CACHE_LINE_BYTES, LOAD);
275 CLIB_PREFETCH (b[6]->data, CLIB_CACHE_LINE_BYTES, LOAD);
276 CLIB_PREFETCH (b[7]->data, CLIB_CACHE_LINE_BYTES, LOAD);
279 /* RX interface handles */
280 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
281 sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
282 sw_if_index2 = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
283 sw_if_index3 = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
285 h0 = vlib_buffer_get_current (b[0]);
286 h1 = vlib_buffer_get_current (b[1]);
287 h2 = vlib_buffer_get_current (b[2]);
288 h3 = vlib_buffer_get_current (b[3]);
291 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
294 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
295 h0->dst_address, h1->dst_address,
296 h2->dst_address, h3->dst_address,
297 vnet_buffer (b[0])->l2.bd_index,
298 vnet_buffer (b[1])->l2.bd_index,
299 vnet_buffer (b[2])->l2.bd_index,
300 vnet_buffer (b[3])->l2.bd_index,
301 &key0, /* not used */
302 &key1, /* not used */
303 &key2, /* not used */
304 &key3, /* not used */
310 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
311 l2fwd_process (vm, node, msm, em, b[1], sw_if_index1, &result1,
313 l2fwd_process (vm, node, msm, em, b[2], sw_if_index2, &result2,
315 l2fwd_process (vm, node, msm, em, b[3], sw_if_index3, &result3,
318 /* verify speculative enqueues, maybe switch current next frame */
319 /* if next0==next1==next_index then nothing special needs to be done */
322 if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
324 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
325 t->sw_if_index = sw_if_index0;
326 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
327 clib_memcpy_fast (t->dst, h0->dst_address,
328 sizeof (h0->dst_address) +
329 sizeof (h0->src_address));
332 if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
334 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t));
335 t->sw_if_index = sw_if_index1;
336 t->bd_index = vnet_buffer (b[1])->l2.bd_index;
337 clib_memcpy_fast (t->dst, h1->dst_address,
338 sizeof (h1->dst_address) +
339 sizeof (h1->src_address));
342 if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
344 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t));
345 t->sw_if_index = sw_if_index2;
346 t->bd_index = vnet_buffer (b[2])->l2.bd_index;
347 clib_memcpy_fast (t->dst, h2->dst_address,
348 sizeof (h2->dst_address) +
349 sizeof (h2->src_address));
352 if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
354 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t));
355 t->sw_if_index = sw_if_index3;
356 t->bd_index = vnet_buffer (b[3])->l2.bd_index;
357 clib_memcpy_fast (t->dst, h3->dst_address,
358 sizeof (h3->dst_address) +
359 sizeof (h3->src_address));
372 ethernet_header_t *h0;
373 l2fib_entry_key_t key0;
374 l2fib_entry_result_t result0;
376 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
378 h0 = vlib_buffer_get_current (b[0]);
382 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
384 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result,
385 h0->dst_address, vnet_buffer (b[0])->l2.bd_index, &key0,
386 /* not used */ &result0);
387 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
389 if (do_trace && PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
391 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
392 t->sw_if_index = sw_if_index0;
393 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
394 clib_memcpy_fast (t->dst, h0->dst_address,
395 sizeof (h0->dst_address) +
396 sizeof (h0->src_address));
400 /* verify speculative enqueue, maybe switch current next frame */
406 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
408 return frame->n_vectors;
411 VLIB_NODE_FN (l2fwd_node) (vlib_main_t * vm,
412 vlib_node_runtime_t * node, vlib_frame_t * frame)
414 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
415 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
416 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
420 VLIB_REGISTER_NODE (l2fwd_node) = {
422 .vector_size = sizeof (u32),
423 .format_trace = format_l2fwd_trace,
424 .type = VLIB_NODE_TYPE_INTERNAL,
426 .n_errors = ARRAY_LEN(l2fwd_error_strings),
427 .error_strings = l2fwd_error_strings,
429 .n_next_nodes = L2FWD_N_NEXT,
431 /* edit / add dispositions here */
433 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
434 [L2FWD_NEXT_DROP] = "error-drop",
439 #ifndef CLIB_MARCH_VARIANT
441 l2fwd_init (vlib_main_t * vm)
443 l2fwd_main_t *mp = &l2fwd_main;
446 mp->vnet_main = vnet_get_main ();
448 /* Initialize the feature next-node indexes */
449 feat_bitmap_init_next_nodes (vm,
452 l2input_get_feat_names (),
453 mp->feat_next_node_index);
455 /* init the hash table ptr */
456 mp->mac_table = get_mac_table ();
458 /* Initialize the next nodes for each ethertype */
459 next_by_ethertype_init (&mp->l3_next);
464 VLIB_INIT_FUNCTION (l2fwd_init);
467 /** Add the L3 input node for this ethertype to the next nodes structure. */
469 l2fwd_register_input_type (vlib_main_t * vm,
470 ethernet_type_t type, u32 node_index)
472 l2fwd_main_t *mp = &l2fwd_main;
475 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
477 next_by_ethertype_register (&mp->l3_next, type, next_index);
482 * Set subinterface forward enable/disable.
484 * set interface l2 forward <interface> [disable]
486 static clib_error_t *
487 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
489 vnet_main_t *vnm = vnet_get_main ();
490 clib_error_t *error = 0;
494 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
496 error = clib_error_return (0, "unknown interface `%U'",
497 format_unformat_error, input);
502 if (unformat (input, "disable"))
507 /* set the interface flag */
508 if (l2input_intf_config (sw_if_index)->xconnect)
510 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
514 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
522 * Layer 2 unicast forwarding can be enabled and disabled on each
523 * interface and on each bridge-domain. Use this command to
524 * manage interfaces. It is enabled by default.
527 * Example of how to enable forwarding:
528 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
529 * Example of how to disable forwarding:
530 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
533 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
534 .path = "set interface l2 forward",
535 .short_help = "set interface l2 forward <interface> [disable]",
543 * fd.io coding-style-patch-verification: ON
546 * eval: (c-set-style "gnu")