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>
29 #include <vppinfra/error.h>
30 #include <vppinfra/hash.h>
31 #include <vppinfra/sparse_vec.h>
36 * @brief Ethernet Forwarding.
38 * Code in this file handles forwarding Layer 2 packets. This file calls
39 * the FIB lookup, packet learning and the packet flooding as necessary.
40 * Packet is then sent to the next graph node.
47 BVT (clib_bihash) * mac_table;
49 /* next node index for the L3 input node of each ethertype */
50 next_by_ethertype_t l3_next;
52 /* Next nodes for each feature */
53 u32 feat_next_node_index[32];
55 /* convenience variables */
56 vlib_main_t *vlib_main;
57 vnet_main_t *vnet_main;
62 /* per-pkt trace data */
69 /* packet trace format function */
71 format_l2fwd_trace (u8 * s, va_list * args)
73 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
74 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
75 l2fwd_trace_t *t = va_arg (*args, l2fwd_trace_t *);
77 s = format (s, "l2-fwd: sw_if_index %d dst %U src %U bd_index %d",
79 format_ethernet_address, t->dst,
80 format_ethernet_address, t->src, t->bd_index);
84 l2fwd_main_t l2fwd_main;
86 static vlib_node_registration_t l2fwd_node;
88 #define foreach_l2fwd_error \
89 _(L2FWD, "L2 forward packets") \
90 _(FLOOD, "L2 forward misses") \
91 _(HIT, "L2 forward hits") \
92 _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \
93 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
94 _(FILTER_DROP, "Filter Mac Drop") \
95 _(REFLECT_DROP, "Reflection Drop") \
96 _(STALE_DROP, "Stale entry Drop")
100 #define _(sym,str) L2FWD_ERROR_##sym,
106 static char *l2fwd_error_strings[] = {
107 #define _(sym,string) string,
114 L2FWD_NEXT_L2_OUTPUT,
119 /** Forward one packet based on the mac table lookup result. */
121 static_always_inline void
122 l2fwd_process (vlib_main_t * vm,
123 vlib_node_runtime_t * node,
125 vlib_error_main_t * em,
127 u32 sw_if_index0, l2fib_entry_result_t * result0, u32 * next0)
129 int try_flood = result0->raw == ~0;
132 if (PREDICT_FALSE (try_flood))
134 flood_error = L2FWD_ERROR_FLOOD;
138 /* lookup hit, forward packet */
140 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
143 vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
144 *next0 = L2FWD_NEXT_L2_OUTPUT;
145 int l2fib_seq_num_valid = 1;
147 /* check l2fib seq num for stale entries */
148 if (!result0->fields.age_not)
150 l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn };
151 l2fib_seq_num_t expected_sn = {
153 .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index),
155 l2fib_seq_num_valid =
156 expected_sn.as_u16 == result0->fields.sn.as_u16;
159 if (PREDICT_FALSE (!l2fib_seq_num_valid))
161 flood_error = L2FWD_ERROR_STALE_DROP;
164 /* perform reflection check */
165 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
167 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
168 *next0 = L2FWD_NEXT_DROP;
170 /* perform filter check */
171 else if (PREDICT_FALSE (result0->fields.filter))
173 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
174 *next0 = L2FWD_NEXT_DROP;
176 /* perform BVI check */
177 else if (PREDICT_FALSE (result0->fields.bvi))
183 vnet_buffer (b0)->sw_if_index[VLIB_TX],
184 &msm->l3_next, next0);
186 if (PREDICT_FALSE (rc))
188 if (rc == TO_BVI_ERR_BAD_MAC)
190 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
191 *next0 = L2FWD_NEXT_DROP;
193 else if (rc == TO_BVI_ERR_ETHERTYPE)
195 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
196 *next0 = L2FWD_NEXT_DROP;
203 if (PREDICT_FALSE (try_flood))
206 * lookup miss, so flood which is typically the next feature
207 * unless some other feature is inserted before uu_flood
209 if (vnet_buffer (b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD)
211 *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
216 /* Flooding is disabled */
217 b0->error = node->errors[flood_error];
218 *next0 = L2FWD_NEXT_DROP;
225 static_always_inline uword
226 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
227 vlib_frame_t * frame, int do_trace)
229 u32 n_left_from, *from, *to_next;
230 l2fwd_next_t next_index;
231 l2fwd_main_t *msm = &l2fwd_main;
232 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
233 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
234 vlib_error_main_t *em = &vm->error_main;
235 l2fib_entry_key_t cached_key;
236 l2fib_entry_result_t cached_result;
238 /* Clear the one-entry cache in case mac table was updated */
240 cached_result.raw = ~0;
242 from = vlib_frame_vector_args (frame);
243 n_left_from = frame->n_vectors; /* number of packets to process */
244 next_index = node->cached_next_index;
246 while (n_left_from > 0)
250 /* get space to enqueue frame to graph node "next_index" */
251 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
253 while (n_left_from >= 8 && n_left_to_next >= 4)
255 u32 bi0, bi1, bi2, bi3;
256 vlib_buffer_t *b0, *b1, *b2, *b3;
257 u32 next0, next1, next2, next3;
258 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
259 ethernet_header_t *h0, *h1, *h2, *h3;
260 l2fib_entry_key_t key0, key1, key2, key3;
261 l2fib_entry_result_t result0, result1, result2, result3;
262 u32 bucket0, bucket1, bucket2, bucket3;
264 /* Prefetch next iteration. */
266 vlib_buffer_t *p4, *p5, *p6, *p7;
268 p4 = vlib_get_buffer (vm, from[4]);
269 p5 = vlib_get_buffer (vm, from[5]);
270 p6 = vlib_get_buffer (vm, from[6]);
271 p7 = vlib_get_buffer (vm, from[7]);
273 vlib_prefetch_buffer_header (p4, LOAD);
274 vlib_prefetch_buffer_header (p5, LOAD);
275 vlib_prefetch_buffer_header (p6, LOAD);
276 vlib_prefetch_buffer_header (p7, LOAD);
278 CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
279 CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
280 CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
281 CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
284 /* speculatively enqueue b0 and b1 to the current next frame */
285 /* bi is "buffer index", b is pointer to the buffer */
286 to_next[0] = bi0 = from[0];
287 to_next[1] = bi1 = from[1];
288 to_next[2] = bi2 = from[2];
289 to_next[3] = bi3 = from[3];
295 b0 = vlib_get_buffer (vm, bi0);
296 b1 = vlib_get_buffer (vm, bi1);
297 b2 = vlib_get_buffer (vm, bi2);
298 b3 = vlib_get_buffer (vm, bi3);
300 /* RX interface handles */
301 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
302 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
303 sw_if_index2 = vnet_buffer (b2)->sw_if_index[VLIB_RX];
304 sw_if_index3 = vnet_buffer (b3)->sw_if_index[VLIB_RX];
306 h0 = vlib_buffer_get_current (b0);
307 h1 = vlib_buffer_get_current (b1);
308 h2 = vlib_buffer_get_current (b2);
309 h3 = vlib_buffer_get_current (b3);
313 if (b0->flags & VLIB_BUFFER_IS_TRACED)
316 vlib_add_trace (vm, node, b0, sizeof (*t));
317 t->sw_if_index = sw_if_index0;
318 t->bd_index = vnet_buffer (b0)->l2.bd_index;
319 clib_memcpy (t->src, h0->src_address, 6);
320 clib_memcpy (t->dst, h0->dst_address, 6);
322 if (b1->flags & VLIB_BUFFER_IS_TRACED)
325 vlib_add_trace (vm, node, b1, sizeof (*t));
326 t->sw_if_index = sw_if_index1;
327 t->bd_index = vnet_buffer (b1)->l2.bd_index;
328 clib_memcpy (t->src, h1->src_address, 6);
329 clib_memcpy (t->dst, h1->dst_address, 6);
331 if (b2->flags & VLIB_BUFFER_IS_TRACED)
334 vlib_add_trace (vm, node, b2, sizeof (*t));
335 t->sw_if_index = sw_if_index2;
336 t->bd_index = vnet_buffer (b2)->l2.bd_index;
337 clib_memcpy (t->src, h2->src_address, 6);
338 clib_memcpy (t->dst, h2->dst_address, 6);
340 if (b3->flags & VLIB_BUFFER_IS_TRACED)
343 vlib_add_trace (vm, node, b3, sizeof (*t));
344 t->sw_if_index = sw_if_index3;
345 t->bd_index = vnet_buffer (b3)->l2.bd_index;
346 clib_memcpy (t->src, h3->src_address, 6);
347 clib_memcpy (t->dst, h3->dst_address, 6);
353 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
356 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
357 h0->dst_address, h1->dst_address,
358 h2->dst_address, h3->dst_address,
359 vnet_buffer (b0)->l2.bd_index,
360 vnet_buffer (b1)->l2.bd_index,
361 vnet_buffer (b2)->l2.bd_index,
362 vnet_buffer (b3)->l2.bd_index,
363 &key0, /* not used */
364 &key1, /* not used */
365 &key2, /* not used */
366 &key3, /* not used */
367 &bucket0, /* not used */
368 &bucket1, /* not used */
369 &bucket2, /* not used */
370 &bucket3, /* not used */
376 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
378 l2fwd_process (vm, node, msm, em, b1, sw_if_index1, &result1,
380 l2fwd_process (vm, node, msm, em, b2, sw_if_index2, &result2,
382 l2fwd_process (vm, node, msm, em, b3, sw_if_index3, &result3,
385 /* verify speculative enqueues, maybe switch current next frame */
386 /* if next0==next1==next_index then nothing special needs to be done */
387 vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
388 to_next, n_left_to_next,
390 next0, next1, next2, next3);
393 while (n_left_from > 0 && n_left_to_next > 0)
399 ethernet_header_t *h0;
400 l2fib_entry_key_t key0;
401 l2fib_entry_result_t result0;
404 /* speculatively enqueue b0 to the current next frame */
412 b0 = vlib_get_buffer (vm, bi0);
414 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
416 h0 = vlib_buffer_get_current (b0);
418 if (do_trace && PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
420 l2fwd_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
421 t->sw_if_index = sw_if_index0;
422 t->bd_index = vnet_buffer (b0)->l2.bd_index;
423 clib_memcpy (t->src, h0->src_address, 6);
424 clib_memcpy (t->dst, h0->dst_address, 6);
429 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
431 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, vnet_buffer (b0)->l2.bd_index, &key0, /* not used */
432 &bucket0, /* not used */
434 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
437 /* verify speculative enqueue, maybe switch current next frame */
438 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
439 to_next, n_left_to_next,
443 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
446 return frame->n_vectors;
450 l2fwd_node_fn (vlib_main_t * vm,
451 vlib_node_runtime_t * node, vlib_frame_t * frame)
453 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
454 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
455 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
459 VLIB_REGISTER_NODE (l2fwd_node,static) = {
460 .function = l2fwd_node_fn,
462 .vector_size = sizeof (u32),
463 .format_trace = format_l2fwd_trace,
464 .type = VLIB_NODE_TYPE_INTERNAL,
466 .n_errors = ARRAY_LEN(l2fwd_error_strings),
467 .error_strings = l2fwd_error_strings,
469 .n_next_nodes = L2FWD_N_NEXT,
471 /* edit / add dispositions here */
473 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
474 [L2FWD_NEXT_DROP] = "error-drop",
479 VLIB_NODE_FUNCTION_MULTIARCH (l2fwd_node, l2fwd_node_fn)
480 clib_error_t *l2fwd_init (vlib_main_t * vm)
482 l2fwd_main_t *mp = &l2fwd_main;
485 mp->vnet_main = vnet_get_main ();
487 /* Initialize the feature next-node indexes */
488 feat_bitmap_init_next_nodes (vm,
491 l2input_get_feat_names (),
492 mp->feat_next_node_index);
494 /* init the hash table ptr */
495 mp->mac_table = get_mac_table ();
497 /* Initialize the next nodes for each ethertype */
498 next_by_ethertype_init (&mp->l3_next);
503 VLIB_INIT_FUNCTION (l2fwd_init);
506 /** Add the L3 input node for this ethertype to the next nodes structure. */
508 l2fwd_register_input_type (vlib_main_t * vm,
509 ethernet_type_t type, u32 node_index)
511 l2fwd_main_t *mp = &l2fwd_main;
514 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
516 next_by_ethertype_register (&mp->l3_next, type, next_index);
521 * Set subinterface forward enable/disable.
523 * set interface l2 forward <interface> [disable]
525 static clib_error_t *
526 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
528 vnet_main_t *vnm = vnet_get_main ();
529 clib_error_t *error = 0;
533 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
535 error = clib_error_return (0, "unknown interface `%U'",
536 format_unformat_error, input);
541 if (unformat (input, "disable"))
546 /* set the interface flag */
547 if (l2input_intf_config (sw_if_index)->xconnect)
549 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
553 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
561 * Layer 2 unicast forwarding can be enabled and disabled on each
562 * interface and on each bridge-domain. Use this command to
563 * manage interfaces. It is enabled by default.
566 * Example of how to enable fowarding:
567 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
568 * Example of how to disable fowarding:
569 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
572 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
573 .path = "set interface l2 forward",
574 .short_help = "set interface l2 forward <interface> [disable]",
580 * fd.io coding-style-patch-verification: ON
583 * eval: (c-set-style "gnu")