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 /* convenience variables */
53 vlib_main_t *vlib_main;
54 vnet_main_t *vnet_main;
59 /* per-pkt trace data */
66 /* packet trace format function */
68 format_l2fwd_trace (u8 * s, va_list * args)
70 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
71 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
72 l2fwd_trace_t *t = va_arg (*args, l2fwd_trace_t *);
74 s = format (s, "l2-fwd: sw_if_index %d dst %U src %U bd_index %d",
76 format_ethernet_address, t->dst,
77 format_ethernet_address, t->src, t->bd_index);
81 l2fwd_main_t l2fwd_main;
83 static vlib_node_registration_t l2fwd_node;
85 #define foreach_l2fwd_error \
86 _(L2FWD, "L2 forward packets") \
87 _(FLOOD, "L2 forward misses") \
88 _(HIT, "L2 forward hits") \
89 _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \
90 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
91 _(FILTER_DROP, "Filter Mac Drop") \
92 _(REFLECT_DROP, "Reflection Drop") \
93 _(STALE_DROP, "Stale entry Drop")
97 #define _(sym,str) L2FWD_ERROR_##sym,
103 static char *l2fwd_error_strings[] = {
104 #define _(sym,string) string,
111 L2FWD_NEXT_L2_OUTPUT,
117 /** Forward one packet based on the mac table lookup result. */
119 static_always_inline void
120 l2fwd_process (vlib_main_t * vm,
121 vlib_node_runtime_t * node,
123 vlib_error_main_t * em,
125 u32 sw_if_index0, l2fib_entry_result_t * result0, u32 * next0)
127 int try_flood = result0->raw == ~0;
130 if (PREDICT_FALSE (try_flood))
132 flood_error = L2FWD_ERROR_FLOOD;
136 /* lookup hit, forward packet */
138 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
141 vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
142 *next0 = L2FWD_NEXT_L2_OUTPUT;
143 int l2fib_seq_num_valid = 1;
145 /* check l2fib seq num for stale entries */
146 if (!result0->fields.age_not)
148 l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn };
149 l2fib_seq_num_t expected_sn = {
151 .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index),
153 l2fib_seq_num_valid =
154 expected_sn.as_u16 == result0->fields.sn.as_u16;
157 if (PREDICT_FALSE (!l2fib_seq_num_valid))
159 flood_error = L2FWD_ERROR_STALE_DROP;
162 /* perform reflection check */
163 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
165 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
166 *next0 = L2FWD_NEXT_DROP;
168 /* perform filter check */
169 else if (PREDICT_FALSE (result0->fields.filter))
171 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
172 *next0 = L2FWD_NEXT_DROP;
174 /* perform BVI check */
175 else if (PREDICT_FALSE (result0->fields.bvi))
181 vnet_buffer (b0)->sw_if_index[VLIB_TX],
182 &msm->l3_next, next0);
184 if (PREDICT_FALSE (rc))
186 if (rc == TO_BVI_ERR_BAD_MAC)
188 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
189 *next0 = L2FWD_NEXT_DROP;
191 else if (rc == TO_BVI_ERR_ETHERTYPE)
193 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
194 *next0 = L2FWD_NEXT_DROP;
201 if (PREDICT_FALSE (try_flood))
204 * lookup miss, so flood
205 * TODO:replicate packet to each intf in bridge-domain
208 if (vnet_buffer (b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD)
210 *next0 = L2FWD_NEXT_FLOOD;
214 /* Flooding is disabled */
215 b0->error = node->errors[flood_error];
216 *next0 = L2FWD_NEXT_DROP;
223 static_always_inline uword
224 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
225 vlib_frame_t * frame, int do_trace)
227 u32 n_left_from, *from, *to_next;
228 l2fwd_next_t next_index;
229 l2fwd_main_t *msm = &l2fwd_main;
230 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
231 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
232 vlib_error_main_t *em = &vm->error_main;
233 l2fib_entry_key_t cached_key;
234 l2fib_entry_result_t cached_result;
236 /* Clear the one-entry cache in case mac table was updated */
238 cached_result.raw = ~0;
240 from = vlib_frame_vector_args (frame);
241 n_left_from = frame->n_vectors; /* number of packets to process */
242 next_index = node->cached_next_index;
244 while (n_left_from > 0)
248 /* get space to enqueue frame to graph node "next_index" */
249 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
251 while (n_left_from >= 8 && n_left_to_next >= 4)
253 u32 bi0, bi1, bi2, bi3;
254 vlib_buffer_t *b0, *b1, *b2, *b3;
255 u32 next0, next1, next2, next3;
256 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
257 ethernet_header_t *h0, *h1, *h2, *h3;
258 l2fib_entry_key_t key0, key1, key2, key3;
259 l2fib_entry_result_t result0, result1, result2, result3;
260 u32 bucket0, bucket1, bucket2, bucket3;
262 /* Prefetch next iteration. */
264 vlib_buffer_t *p4, *p5, *p6, *p7;
266 p4 = vlib_get_buffer (vm, from[4]);
267 p5 = vlib_get_buffer (vm, from[5]);
268 p6 = vlib_get_buffer (vm, from[6]);
269 p7 = vlib_get_buffer (vm, from[7]);
271 vlib_prefetch_buffer_header (p4, LOAD);
272 vlib_prefetch_buffer_header (p5, LOAD);
273 vlib_prefetch_buffer_header (p6, LOAD);
274 vlib_prefetch_buffer_header (p7, LOAD);
276 CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
277 CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
278 CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
279 CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
282 /* speculatively enqueue b0 and b1 to the current next frame */
283 /* bi is "buffer index", b is pointer to the buffer */
284 to_next[0] = bi0 = from[0];
285 to_next[1] = bi1 = from[1];
286 to_next[2] = bi2 = from[2];
287 to_next[3] = bi3 = from[3];
293 b0 = vlib_get_buffer (vm, bi0);
294 b1 = vlib_get_buffer (vm, bi1);
295 b2 = vlib_get_buffer (vm, bi2);
296 b3 = vlib_get_buffer (vm, bi3);
298 /* RX interface handles */
299 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
300 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
301 sw_if_index2 = vnet_buffer (b2)->sw_if_index[VLIB_RX];
302 sw_if_index3 = vnet_buffer (b3)->sw_if_index[VLIB_RX];
304 h0 = vlib_buffer_get_current (b0);
305 h1 = vlib_buffer_get_current (b1);
306 h2 = vlib_buffer_get_current (b2);
307 h3 = vlib_buffer_get_current (b3);
311 if (b0->flags & VLIB_BUFFER_IS_TRACED)
314 vlib_add_trace (vm, node, b0, sizeof (*t));
315 t->sw_if_index = sw_if_index0;
316 t->bd_index = vnet_buffer (b0)->l2.bd_index;
317 clib_memcpy (t->src, h0->src_address, 6);
318 clib_memcpy (t->dst, h0->dst_address, 6);
320 if (b1->flags & VLIB_BUFFER_IS_TRACED)
323 vlib_add_trace (vm, node, b1, sizeof (*t));
324 t->sw_if_index = sw_if_index1;
325 t->bd_index = vnet_buffer (b1)->l2.bd_index;
326 clib_memcpy (t->src, h1->src_address, 6);
327 clib_memcpy (t->dst, h1->dst_address, 6);
329 if (b2->flags & VLIB_BUFFER_IS_TRACED)
332 vlib_add_trace (vm, node, b2, sizeof (*t));
333 t->sw_if_index = sw_if_index2;
334 t->bd_index = vnet_buffer (b2)->l2.bd_index;
335 clib_memcpy (t->src, h2->src_address, 6);
336 clib_memcpy (t->dst, h2->dst_address, 6);
338 if (b3->flags & VLIB_BUFFER_IS_TRACED)
341 vlib_add_trace (vm, node, b3, sizeof (*t));
342 t->sw_if_index = sw_if_index3;
343 t->bd_index = vnet_buffer (b3)->l2.bd_index;
344 clib_memcpy (t->src, h3->src_address, 6);
345 clib_memcpy (t->dst, h3->dst_address, 6);
351 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
354 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
355 h0->dst_address, h1->dst_address,
356 h2->dst_address, h3->dst_address,
357 vnet_buffer (b0)->l2.bd_index,
358 vnet_buffer (b1)->l2.bd_index,
359 vnet_buffer (b2)->l2.bd_index,
360 vnet_buffer (b3)->l2.bd_index,
361 &key0, /* not used */
362 &key1, /* not used */
363 &key2, /* not used */
364 &key3, /* not used */
365 &bucket0, /* not used */
366 &bucket1, /* not used */
367 &bucket2, /* not used */
368 &bucket3, /* not used */
374 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
376 l2fwd_process (vm, node, msm, em, b1, sw_if_index1, &result1,
378 l2fwd_process (vm, node, msm, em, b2, sw_if_index2, &result2,
380 l2fwd_process (vm, node, msm, em, b3, sw_if_index3, &result3,
383 /* verify speculative enqueues, maybe switch current next frame */
384 /* if next0==next1==next_index then nothing special needs to be done */
385 vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
386 to_next, n_left_to_next,
388 next0, next1, next2, next3);
391 while (n_left_from > 0 && n_left_to_next > 0)
397 ethernet_header_t *h0;
398 l2fib_entry_key_t key0;
399 l2fib_entry_result_t result0;
402 /* speculatively enqueue b0 to the current next frame */
410 b0 = vlib_get_buffer (vm, bi0);
412 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
414 h0 = vlib_buffer_get_current (b0);
416 if (do_trace && PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
418 l2fwd_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
419 t->sw_if_index = sw_if_index0;
420 t->bd_index = vnet_buffer (b0)->l2.bd_index;
421 clib_memcpy (t->src, h0->src_address, 6);
422 clib_memcpy (t->dst, h0->dst_address, 6);
427 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
429 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, vnet_buffer (b0)->l2.bd_index, &key0, /* not used */
430 &bucket0, /* not used */
432 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0,
435 /* verify speculative enqueue, maybe switch current next frame */
436 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
437 to_next, n_left_to_next,
441 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
444 return frame->n_vectors;
448 l2fwd_node_fn (vlib_main_t * vm,
449 vlib_node_runtime_t * node, vlib_frame_t * frame)
451 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
452 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
453 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
457 VLIB_REGISTER_NODE (l2fwd_node,static) = {
458 .function = l2fwd_node_fn,
460 .vector_size = sizeof (u32),
461 .format_trace = format_l2fwd_trace,
462 .type = VLIB_NODE_TYPE_INTERNAL,
464 .n_errors = ARRAY_LEN(l2fwd_error_strings),
465 .error_strings = l2fwd_error_strings,
467 .n_next_nodes = L2FWD_N_NEXT,
469 /* edit / add dispositions here */
471 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
472 [L2FWD_NEXT_FLOOD] = "l2-flood",
473 [L2FWD_NEXT_DROP] = "error-drop",
478 VLIB_NODE_FUNCTION_MULTIARCH (l2fwd_node, l2fwd_node_fn)
479 clib_error_t *l2fwd_init (vlib_main_t * vm)
481 l2fwd_main_t *mp = &l2fwd_main;
484 mp->vnet_main = vnet_get_main ();
486 /* init the hash table ptr */
487 mp->mac_table = get_mac_table ();
489 /* Initialize the next nodes for each ethertype */
490 next_by_ethertype_init (&mp->l3_next);
495 VLIB_INIT_FUNCTION (l2fwd_init);
498 /** Add the L3 input node for this ethertype to the next nodes structure. */
500 l2fwd_register_input_type (vlib_main_t * vm,
501 ethernet_type_t type, u32 node_index)
503 l2fwd_main_t *mp = &l2fwd_main;
506 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
508 next_by_ethertype_register (&mp->l3_next, type, next_index);
513 * Set subinterface forward enable/disable.
515 * set interface l2 forward <interface> [disable]
517 static clib_error_t *
518 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
520 vnet_main_t *vnm = vnet_get_main ();
521 clib_error_t *error = 0;
525 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
527 error = clib_error_return (0, "unknown interface `%U'",
528 format_unformat_error, input);
533 if (unformat (input, "disable"))
538 /* set the interface flag */
539 if (l2input_intf_config (sw_if_index)->xconnect)
541 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
545 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
553 * Layer 2 unicast forwarding can be enabled and disabled on each
554 * interface and on each bridge-domain. Use this command to
555 * manage interfaces. It is enabled by default.
558 * Example of how to enable fowarding:
559 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
560 * Example of how to disable fowarding:
561 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
564 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
565 .path = "set interface l2 forward",
566 .short_help = "set interface l2 forward <interface> [disable]",
572 * fd.io coding-style-patch-verification: ON
575 * eval: (c-set-style "gnu")