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 */
67 l2fib_entry_result_t result;
70 /* packet trace format function */
72 format_l2fwd_trace (u8 * s, va_list * args)
74 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
75 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
76 l2fwd_trace_t *t = va_arg (*args, l2fwd_trace_t *);
80 "l2-fwd: sw_if_index %d dst %U src %U bd_index %d result [0x%llx, %d] %U",
81 t->sw_if_index, format_ethernet_address, t->dst_and_src,
82 format_ethernet_address, t->dst_and_src + 6,
83 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 = vnet_buffer (b0)->l2.l2fib_sn;
160 l2fib_seq_num_t expected_sn = l2_fib_update_seq_num (in_sn,
162 (result0->fields.sw_if_index));
164 l2fib_seq_num_valid = expected_sn == result0->fields.sn;
167 if (PREDICT_FALSE (!l2fib_seq_num_valid))
169 flood_error = L2FWD_ERROR_STALE_DROP;
172 /* perform reflection check */
173 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
175 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
176 *next0 = L2FWD_NEXT_DROP;
178 /* perform filter check */
179 else if (PREDICT_FALSE (l2fib_entry_result_is_set_FILTER (result0)))
181 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
182 *next0 = L2FWD_NEXT_DROP;
184 /* perform BVI check */
185 else if (PREDICT_FALSE (l2fib_entry_result_is_set_BVI (result0)))
191 vnet_buffer (b0)->sw_if_index[VLIB_TX],
192 &msm->l3_next, next0);
194 if (PREDICT_FALSE (rc))
196 if (rc == TO_BVI_ERR_BAD_MAC)
198 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
199 *next0 = L2FWD_NEXT_DROP;
201 else if (rc == TO_BVI_ERR_ETHERTYPE)
203 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
204 *next0 = L2FWD_NEXT_DROP;
211 if (PREDICT_FALSE (try_flood))
214 * lookup miss, so flood which is typically the next feature
215 * unless some other feature is inserted before uu_flood
217 if (vnet_buffer (b0)->l2.feature_bitmap &
218 (L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_UU_FWD))
220 *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
225 /* Flooding is disabled */
226 b0->error = node->errors[flood_error];
227 *next0 = L2FWD_NEXT_DROP;
233 static_always_inline uword
234 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
235 vlib_frame_t * frame, int do_trace)
238 l2fwd_main_t *msm = &l2fwd_main;
239 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
240 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
241 vlib_error_main_t *em = &vm->error_main;
242 l2fib_entry_key_t cached_key;
243 l2fib_entry_result_t cached_result;
244 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
245 u16 nexts[VLIB_FRAME_SIZE], *next;
247 /* Clear the one-entry cache in case mac table was updated */
249 cached_result.raw = ~0;
251 from = vlib_frame_vector_args (frame);
252 n_left = frame->n_vectors; /* number of packets to process */
253 vlib_get_buffers (vm, from, bufs, n_left);
259 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
260 const ethernet_header_t *h0, *h1, *h2, *h3;
261 l2fib_entry_key_t key0, key1, key2, key3;
262 l2fib_entry_result_t result0, result1, result2, result3;
264 /* Prefetch next iteration. */
266 vlib_prefetch_buffer_header (b[4], LOAD);
267 vlib_prefetch_buffer_header (b[5], LOAD);
268 vlib_prefetch_buffer_header (b[6], LOAD);
269 vlib_prefetch_buffer_header (b[7], LOAD);
271 clib_prefetch_load (b[4]->data);
272 clib_prefetch_load (b[5]->data);
273 clib_prefetch_load (b[6]->data);
274 clib_prefetch_load (b[7]->data);
277 /* RX interface handles */
278 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
279 sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
280 sw_if_index2 = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
281 sw_if_index3 = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
283 h0 = vlib_buffer_get_current (b[0]);
284 h1 = vlib_buffer_get_current (b[1]);
285 h2 = vlib_buffer_get_current (b[2]);
286 h3 = vlib_buffer_get_current (b[3]);
289 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
292 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
293 h0->dst_address, h1->dst_address,
294 h2->dst_address, h3->dst_address,
295 vnet_buffer (b[0])->l2.bd_index,
296 vnet_buffer (b[1])->l2.bd_index,
297 vnet_buffer (b[2])->l2.bd_index,
298 vnet_buffer (b[3])->l2.bd_index,
299 &key0, /* not used */
300 &key1, /* not used */
301 &key2, /* not used */
302 &key3, /* not used */
308 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
309 l2fwd_process (vm, node, msm, em, b[1], sw_if_index1, &result1,
311 l2fwd_process (vm, node, msm, em, b[2], sw_if_index2, &result2,
313 l2fwd_process (vm, node, msm, em, b[3], sw_if_index3, &result3,
316 /* verify speculative enqueues, maybe switch current next frame */
317 /* if next0==next1==next_index then nothing special needs to be done */
320 if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
322 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
323 t->sw_if_index = sw_if_index0;
324 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
325 clib_memcpy_fast (t->dst_and_src, h0->dst_address,
326 sizeof (h0->dst_address) +
327 sizeof (h0->src_address));
330 if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
332 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t));
333 t->sw_if_index = sw_if_index1;
334 t->bd_index = vnet_buffer (b[1])->l2.bd_index;
335 clib_memcpy_fast (t->dst_and_src, h1->dst_address,
336 sizeof (h1->dst_address) +
337 sizeof (h1->src_address));
340 if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
342 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t));
343 t->sw_if_index = sw_if_index2;
344 t->bd_index = vnet_buffer (b[2])->l2.bd_index;
345 clib_memcpy_fast (t->dst_and_src, h2->dst_address,
346 sizeof (h2->dst_address) +
347 sizeof (h2->src_address));
350 if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
352 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t));
353 t->sw_if_index = sw_if_index3;
354 t->bd_index = vnet_buffer (b[3])->l2.bd_index;
355 clib_memcpy_fast (t->dst_and_src, h3->dst_address,
356 sizeof (h3->dst_address) +
357 sizeof (h3->src_address));
370 ethernet_header_t *h0;
371 l2fib_entry_key_t key0;
372 l2fib_entry_result_t result0;
374 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
376 h0 = vlib_buffer_get_current (b[0]);
380 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
382 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result,
383 h0->dst_address, vnet_buffer (b[0])->l2.bd_index, &key0,
384 /* not used */ &result0);
385 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
387 if (do_trace && PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
389 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
390 t->sw_if_index = sw_if_index0;
391 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
392 clib_memcpy_fast (t->dst_and_src, h0->dst_address,
393 sizeof (h0->dst_address) +
394 sizeof (h0->src_address));
398 /* verify speculative enqueue, maybe switch current next frame */
404 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
406 return frame->n_vectors;
409 VLIB_NODE_FN (l2fwd_node) (vlib_main_t * vm,
410 vlib_node_runtime_t * node, vlib_frame_t * frame)
412 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
413 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
414 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
418 VLIB_REGISTER_NODE (l2fwd_node) = {
420 .vector_size = sizeof (u32),
421 .format_trace = format_l2fwd_trace,
422 .type = VLIB_NODE_TYPE_INTERNAL,
424 .n_errors = ARRAY_LEN(l2fwd_error_strings),
425 .error_strings = l2fwd_error_strings,
427 .n_next_nodes = L2FWD_N_NEXT,
429 /* edit / add dispositions here */
431 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
432 [L2FWD_NEXT_DROP] = "error-drop",
437 #ifndef CLIB_MARCH_VARIANT
439 l2fwd_init (vlib_main_t * vm)
441 l2fwd_main_t *mp = &l2fwd_main;
444 mp->vnet_main = vnet_get_main ();
446 /* Initialize the feature next-node indexes */
447 feat_bitmap_init_next_nodes (vm,
450 l2input_get_feat_names (),
451 mp->feat_next_node_index);
453 /* init the hash table ptr */
454 mp->mac_table = get_mac_table ();
456 /* Initialize the next nodes for each ethertype */
457 next_by_ethertype_init (&mp->l3_next);
462 VLIB_INIT_FUNCTION (l2fwd_init);
465 /** Add the L3 input node for this ethertype to the next nodes structure. */
467 l2fwd_register_input_type (vlib_main_t * vm,
468 ethernet_type_t type, u32 node_index)
470 l2fwd_main_t *mp = &l2fwd_main;
473 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
475 next_by_ethertype_register (&mp->l3_next, type, next_index);
480 * Set subinterface forward enable/disable.
482 * set interface l2 forward <interface> [disable]
484 static clib_error_t *
485 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
487 vnet_main_t *vnm = vnet_get_main ();
488 clib_error_t *error = 0;
492 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
494 error = clib_error_return (0, "unknown interface `%U'",
495 format_unformat_error, input);
500 if (unformat (input, "disable"))
505 /* set the interface flag */
506 if (l2input_intf_config (sw_if_index))
508 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
512 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
520 * Layer 2 unicast forwarding can be enabled and disabled on each
521 * interface and on each bridge-domain. Use this command to
522 * manage interfaces. It is enabled by default.
525 * Example of how to enable forwarding:
526 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
527 * Example of how to disable forwarding:
528 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
531 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
532 .path = "set interface l2 forward",
533 .short_help = "set interface l2 forward <interface> [disable]",
541 * fd.io coding-style-patch-verification: ON
544 * eval: (c-set-style "gnu")