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 */
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 *);
78 s = format (s, "l2-fwd: sw_if_index %d dst %U src %U bd_index %d",
80 format_ethernet_address, t->dst,
81 format_ethernet_address, t->src, t->bd_index);
85 l2fwd_main_t l2fwd_main;
87 static vlib_node_registration_t l2fwd_node;
89 #define foreach_l2fwd_error \
90 _(L2FWD, "L2 forward packets") \
91 _(FLOOD, "L2 forward misses") \
92 _(HIT, "L2 forward hits") \
93 _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \
94 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
95 _(FILTER_DROP, "Filter Mac Drop") \
96 _(REFLECT_DROP, "Reflection Drop") \
97 _(STALE_DROP, "Stale entry Drop")
101 #define _(sym,str) L2FWD_ERROR_##sym,
107 static char *l2fwd_error_strings[] = {
108 #define _(sym,string) string,
115 L2FWD_NEXT_L2_OUTPUT,
120 /** Forward one packet based on the mac table lookup result. */
122 static_always_inline void
123 l2fwd_process (vlib_main_t * vm,
124 vlib_node_runtime_t * node,
126 vlib_error_main_t * em,
128 u32 sw_if_index0, l2fib_entry_result_t * result0, u32 * next0)
130 int try_flood = result0->raw == ~0;
133 if (PREDICT_FALSE (try_flood))
135 flood_error = L2FWD_ERROR_FLOOD;
139 /* lookup hit, forward packet */
141 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
144 vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
145 *next0 = L2FWD_NEXT_L2_OUTPUT;
146 int l2fib_seq_num_valid = 1;
148 /* check l2fib seq num for stale entries */
149 if (!l2fib_entry_result_is_set_AGE_NOT (result0))
151 l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn };
152 l2fib_seq_num_t expected_sn = {
154 .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index),
156 l2fib_seq_num_valid =
157 expected_sn.as_u16 == result0->fields.sn.as_u16;
160 if (PREDICT_FALSE (!l2fib_seq_num_valid))
162 flood_error = L2FWD_ERROR_STALE_DROP;
165 /* perform reflection check */
166 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
168 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
169 *next0 = L2FWD_NEXT_DROP;
171 /* perform filter check */
172 else if (PREDICT_FALSE (l2fib_entry_result_is_set_FILTER (result0)))
174 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
175 *next0 = L2FWD_NEXT_DROP;
177 /* perform BVI check */
178 else if (PREDICT_FALSE (l2fib_entry_result_is_set_BVI (result0)))
184 vnet_buffer (b0)->sw_if_index[VLIB_TX],
185 &msm->l3_next, next0);
187 if (PREDICT_FALSE (rc))
189 if (rc == TO_BVI_ERR_BAD_MAC)
191 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
192 *next0 = L2FWD_NEXT_DROP;
194 else if (rc == TO_BVI_ERR_ETHERTYPE)
196 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
197 *next0 = L2FWD_NEXT_DROP;
204 if (PREDICT_FALSE (try_flood))
207 * lookup miss, so flood which is typically the next feature
208 * unless some other feature is inserted before uu_flood
210 if (vnet_buffer (b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD)
212 *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
217 /* Flooding is disabled */
218 b0->error = node->errors[flood_error];
219 *next0 = L2FWD_NEXT_DROP;
226 static_always_inline uword
227 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
228 vlib_frame_t * frame, int do_trace)
230 u32 n_left_from, *from, *to_next;
231 l2fwd_next_t next_index;
232 l2fwd_main_t *msm = &l2fwd_main;
233 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
234 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
235 vlib_error_main_t *em = &vm->error_main;
236 l2fib_entry_key_t cached_key;
237 l2fib_entry_result_t cached_result;
239 /* Clear the one-entry cache in case mac table was updated */
241 cached_result.raw = ~0;
243 from = vlib_frame_vector_args (frame);
244 n_left_from = frame->n_vectors; /* number of packets to process */
245 next_index = node->cached_next_index;
247 while (n_left_from > 0)
251 /* get space to enqueue frame to graph node "next_index" */
252 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
254 while (n_left_from >= 8 && n_left_to_next >= 4)
256 u32 bi0, bi1, bi2, bi3;
257 vlib_buffer_t *b0, *b1, *b2, *b3;
258 u32 next0, next1, next2, next3;
259 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
260 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;
263 u32 bucket0, bucket1, bucket2, bucket3;
265 /* Prefetch next iteration. */
267 vlib_buffer_t *p4, *p5, *p6, *p7;
269 p4 = vlib_get_buffer (vm, from[4]);
270 p5 = vlib_get_buffer (vm, from[5]);
271 p6 = vlib_get_buffer (vm, from[6]);
272 p7 = vlib_get_buffer (vm, from[7]);
274 vlib_prefetch_buffer_header (p4, LOAD);
275 vlib_prefetch_buffer_header (p5, LOAD);
276 vlib_prefetch_buffer_header (p6, LOAD);
277 vlib_prefetch_buffer_header (p7, LOAD);
279 CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
280 CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
281 CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
282 CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
285 /* speculatively enqueue b0 and b1 to the current next frame */
286 /* bi is "buffer index", b is pointer to the buffer */
287 to_next[0] = bi0 = from[0];
288 to_next[1] = bi1 = from[1];
289 to_next[2] = bi2 = from[2];
290 to_next[3] = bi3 = from[3];
296 b0 = vlib_get_buffer (vm, bi0);
297 b1 = vlib_get_buffer (vm, bi1);
298 b2 = vlib_get_buffer (vm, bi2);
299 b3 = vlib_get_buffer (vm, bi3);
301 /* RX interface handles */
302 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
303 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
304 sw_if_index2 = vnet_buffer (b2)->sw_if_index[VLIB_RX];
305 sw_if_index3 = vnet_buffer (b3)->sw_if_index[VLIB_RX];
307 h0 = vlib_buffer_get_current (b0);
308 h1 = vlib_buffer_get_current (b1);
309 h2 = vlib_buffer_get_current (b2);
310 h3 = vlib_buffer_get_current (b3);
314 if (b0->flags & VLIB_BUFFER_IS_TRACED)
317 vlib_add_trace (vm, node, b0, sizeof (*t));
318 t->sw_if_index = sw_if_index0;
319 t->bd_index = vnet_buffer (b0)->l2.bd_index;
320 clib_memcpy (t->src, h0->src_address, 6);
321 clib_memcpy (t->dst, h0->dst_address, 6);
323 if (b1->flags & VLIB_BUFFER_IS_TRACED)
326 vlib_add_trace (vm, node, b1, sizeof (*t));
327 t->sw_if_index = sw_if_index1;
328 t->bd_index = vnet_buffer (b1)->l2.bd_index;
329 clib_memcpy (t->src, h1->src_address, 6);
330 clib_memcpy (t->dst, h1->dst_address, 6);
332 if (b2->flags & VLIB_BUFFER_IS_TRACED)
335 vlib_add_trace (vm, node, b2, sizeof (*t));
336 t->sw_if_index = sw_if_index2;
337 t->bd_index = vnet_buffer (b2)->l2.bd_index;
338 clib_memcpy (t->src, h2->src_address, 6);
339 clib_memcpy (t->dst, h2->dst_address, 6);
341 if (b3->flags & VLIB_BUFFER_IS_TRACED)
344 vlib_add_trace (vm, node, b3, sizeof (*t));
345 t->sw_if_index = sw_if_index3;
346 t->bd_index = vnet_buffer (b3)->l2.bd_index;
347 clib_memcpy (t->src, h3->src_address, 6);
348 clib_memcpy (t->dst, h3->dst_address, 6);
354 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
357 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
358 h0->dst_address, h1->dst_address,
359 h2->dst_address, h3->dst_address,
360 vnet_buffer (b0)->l2.bd_index,
361 vnet_buffer (b1)->l2.bd_index,
362 vnet_buffer (b2)->l2.bd_index,
363 vnet_buffer (b3)->l2.bd_index,
364 &key0, /* not used */
365 &key1, /* not used */
366 &key2, /* not used */
367 &key3, /* not used */
368 &bucket0, /* not used */
369 &bucket1, /* not used */
370 &bucket2, /* not used */
371 &bucket3, /* not used */
377 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
379 l2fwd_process (vm, node, msm, em, b1, sw_if_index1, &result1,
381 l2fwd_process (vm, node, msm, em, b2, sw_if_index2, &result2,
383 l2fwd_process (vm, node, msm, em, b3, sw_if_index3, &result3,
386 /* verify speculative enqueues, maybe switch current next frame */
387 /* if next0==next1==next_index then nothing special needs to be done */
388 vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
389 to_next, n_left_to_next,
391 next0, next1, next2, next3);
394 while (n_left_from > 0 && n_left_to_next > 0)
400 ethernet_header_t *h0;
401 l2fib_entry_key_t key0;
402 l2fib_entry_result_t result0;
405 /* speculatively enqueue b0 to the current next frame */
413 b0 = vlib_get_buffer (vm, bi0);
415 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
417 h0 = vlib_buffer_get_current (b0);
419 if (do_trace && PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
421 l2fwd_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
422 t->sw_if_index = sw_if_index0;
423 t->bd_index = vnet_buffer (b0)->l2.bd_index;
424 clib_memcpy (t->src, h0->src_address, 6);
425 clib_memcpy (t->dst, h0->dst_address, 6);
430 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
432 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, vnet_buffer (b0)->l2.bd_index, &key0, /* not used */
433 &bucket0, /* not used */
435 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
438 /* verify speculative enqueue, maybe switch current next frame */
439 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
440 to_next, n_left_to_next,
444 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
447 return frame->n_vectors;
451 l2fwd_node_fn (vlib_main_t * vm,
452 vlib_node_runtime_t * node, vlib_frame_t * frame)
454 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
455 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
456 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
460 VLIB_REGISTER_NODE (l2fwd_node,static) = {
461 .function = l2fwd_node_fn,
463 .vector_size = sizeof (u32),
464 .format_trace = format_l2fwd_trace,
465 .type = VLIB_NODE_TYPE_INTERNAL,
467 .n_errors = ARRAY_LEN(l2fwd_error_strings),
468 .error_strings = l2fwd_error_strings,
470 .n_next_nodes = L2FWD_N_NEXT,
472 /* edit / add dispositions here */
474 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
475 [L2FWD_NEXT_DROP] = "error-drop",
480 VLIB_NODE_FUNCTION_MULTIARCH (l2fwd_node, l2fwd_node_fn)
481 clib_error_t *l2fwd_init (vlib_main_t * vm)
483 l2fwd_main_t *mp = &l2fwd_main;
486 mp->vnet_main = vnet_get_main ();
488 /* Initialize the feature next-node indexes */
489 feat_bitmap_init_next_nodes (vm,
492 l2input_get_feat_names (),
493 mp->feat_next_node_index);
495 /* init the hash table ptr */
496 mp->mac_table = get_mac_table ();
498 /* Initialize the next nodes for each ethertype */
499 next_by_ethertype_init (&mp->l3_next);
504 VLIB_INIT_FUNCTION (l2fwd_init);
507 /** Add the L3 input node for this ethertype to the next nodes structure. */
509 l2fwd_register_input_type (vlib_main_t * vm,
510 ethernet_type_t type, u32 node_index)
512 l2fwd_main_t *mp = &l2fwd_main;
515 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
517 next_by_ethertype_register (&mp->l3_next, type, next_index);
522 * Set subinterface forward enable/disable.
524 * set interface l2 forward <interface> [disable]
526 static clib_error_t *
527 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
529 vnet_main_t *vnm = vnet_get_main ();
530 clib_error_t *error = 0;
534 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
536 error = clib_error_return (0, "unknown interface `%U'",
537 format_unformat_error, input);
542 if (unformat (input, "disable"))
547 /* set the interface flag */
548 if (l2input_intf_config (sw_if_index)->xconnect)
550 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
554 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
562 * Layer 2 unicast forwarding can be enabled and disabled on each
563 * interface and on each bridge-domain. Use this command to
564 * manage interfaces. It is enabled by default.
567 * Example of how to enable fowarding:
568 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
569 * Example of how to disable fowarding:
570 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
573 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
574 .path = "set interface l2 forward",
575 .short_help = "set interface l2 forward <interface> [disable]",
581 * fd.io coding-style-patch-verification: ON
584 * eval: (c-set-style "gnu")