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 #ifndef CLIB_MARCH_VARIANT
86 l2fwd_main_t l2fwd_main;
88 extern l2fwd_main_t l2fwd_main;
91 static vlib_node_registration_t l2fwd_node;
93 #define foreach_l2fwd_error \
94 _(L2FWD, "L2 forward packets") \
95 _(FLOOD, "L2 forward misses") \
96 _(HIT, "L2 forward hits") \
97 _(BVI_BAD_MAC, "BVI L3 MAC mismatch") \
98 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
99 _(FILTER_DROP, "Filter Mac Drop") \
100 _(REFLECT_DROP, "Reflection Drop") \
101 _(STALE_DROP, "Stale entry Drop")
105 #define _(sym,str) L2FWD_ERROR_##sym,
111 static char *l2fwd_error_strings[] = {
112 #define _(sym,string) string,
119 L2FWD_NEXT_L2_OUTPUT,
124 /** Forward one packet based on the mac table lookup result. */
126 static_always_inline void
127 l2fwd_process (vlib_main_t * vm,
128 vlib_node_runtime_t * node,
130 vlib_error_main_t * em,
132 u32 sw_if_index0, l2fib_entry_result_t * result0, u16 * next0)
134 int try_flood = result0->raw == ~0;
137 if (PREDICT_FALSE (try_flood))
139 flood_error = L2FWD_ERROR_FLOOD;
143 /* lookup hit, forward packet */
145 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
148 vnet_buffer (b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
149 *next0 = L2FWD_NEXT_L2_OUTPUT;
150 int l2fib_seq_num_valid = 1;
152 /* check l2fib seq num for stale entries */
153 if (!l2fib_entry_result_is_set_AGE_NOT (result0))
155 l2fib_seq_num_t in_sn = {.as_u16 = vnet_buffer (b0)->l2.l2fib_sn };
156 l2fib_seq_num_t expected_sn = {
158 .swif = *l2fib_swif_seq_num (result0->fields.sw_if_index),
160 l2fib_seq_num_valid =
161 expected_sn.as_u16 == result0->fields.sn.as_u16;
164 if (PREDICT_FALSE (!l2fib_seq_num_valid))
166 flood_error = L2FWD_ERROR_STALE_DROP;
169 /* perform reflection check */
170 else if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index))
172 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
173 *next0 = L2FWD_NEXT_DROP;
175 /* perform filter check */
176 else if (PREDICT_FALSE (l2fib_entry_result_is_set_FILTER (result0)))
178 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
179 *next0 = L2FWD_NEXT_DROP;
181 /* perform BVI check */
182 else if (PREDICT_FALSE (l2fib_entry_result_is_set_BVI (result0)))
188 vnet_buffer (b0)->sw_if_index[VLIB_TX],
189 &msm->l3_next, next0);
191 if (PREDICT_FALSE (rc))
193 if (rc == TO_BVI_ERR_BAD_MAC)
195 b0->error = node->errors[L2FWD_ERROR_BVI_BAD_MAC];
196 *next0 = L2FWD_NEXT_DROP;
198 else if (rc == TO_BVI_ERR_ETHERTYPE)
200 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
201 *next0 = L2FWD_NEXT_DROP;
208 if (PREDICT_FALSE (try_flood))
211 * lookup miss, so flood which is typically the next feature
212 * unless some other feature is inserted before uu_flood
214 if (vnet_buffer (b0)->l2.feature_bitmap &
215 (L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_UU_FWD))
217 *next0 = vnet_l2_feature_next (b0, msm->feat_next_node_index,
222 /* Flooding is disabled */
223 b0->error = node->errors[flood_error];
224 *next0 = L2FWD_NEXT_DROP;
230 static_always_inline uword
231 l2fwd_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
232 vlib_frame_t * frame, int do_trace)
235 l2fwd_main_t *msm = &l2fwd_main;
236 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
237 CLIB_UNUSED (u32 node_counter_base_index) = n->error_heap_index;
238 vlib_error_main_t *em = &vm->error_main;
239 l2fib_entry_key_t cached_key;
240 l2fib_entry_result_t cached_result;
241 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
242 u16 nexts[VLIB_FRAME_SIZE], *next;
244 /* Clear the one-entry cache in case mac table was updated */
246 cached_result.raw = ~0;
248 from = vlib_frame_vector_args (frame);
249 n_left = frame->n_vectors; /* number of packets to process */
250 vlib_get_buffers (vm, from, bufs, n_left);
256 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
257 const 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_prefetch_buffer_header (b[4], LOAD);
265 vlib_prefetch_buffer_header (b[5], LOAD);
266 vlib_prefetch_buffer_header (b[6], LOAD);
267 vlib_prefetch_buffer_header (b[7], LOAD);
269 CLIB_PREFETCH (b[4]->data, CLIB_CACHE_LINE_BYTES, LOAD);
270 CLIB_PREFETCH (b[5]->data, CLIB_CACHE_LINE_BYTES, LOAD);
271 CLIB_PREFETCH (b[6]->data, CLIB_CACHE_LINE_BYTES, LOAD);
272 CLIB_PREFETCH (b[7]->data, CLIB_CACHE_LINE_BYTES, LOAD);
275 /* RX interface handles */
276 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
277 sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
278 sw_if_index2 = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
279 sw_if_index3 = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
281 h0 = vlib_buffer_get_current (b[0]);
282 h1 = vlib_buffer_get_current (b[1]);
283 h2 = vlib_buffer_get_current (b[2]);
284 h3 = vlib_buffer_get_current (b[3]);
288 if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
290 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
291 t->sw_if_index = sw_if_index0;
292 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
293 clib_memcpy (t->src, h0->src_address, 6);
294 clib_memcpy (t->dst, h0->dst_address, 6);
296 if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
298 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[1], sizeof (*t));
299 t->sw_if_index = sw_if_index1;
300 t->bd_index = vnet_buffer (b[1])->l2.bd_index;
301 clib_memcpy (t->src, h1->src_address, 6);
302 clib_memcpy (t->dst, h1->dst_address, 6);
304 if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
306 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[2], sizeof (*t));
307 t->sw_if_index = sw_if_index2;
308 t->bd_index = vnet_buffer (b[2])->l2.bd_index;
309 clib_memcpy (t->src, h2->src_address, 6);
310 clib_memcpy (t->dst, h2->dst_address, 6);
312 if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
314 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[3], sizeof (*t));
315 t->sw_if_index = sw_if_index3;
316 t->bd_index = vnet_buffer (b[3])->l2.bd_index;
317 clib_memcpy (t->src, h3->src_address, 6);
318 clib_memcpy (t->dst, h3->dst_address, 6);
323 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 4;
326 l2fib_lookup_4 (msm->mac_table, &cached_key, &cached_result,
327 h0->dst_address, h1->dst_address,
328 h2->dst_address, h3->dst_address,
329 vnet_buffer (b[0])->l2.bd_index,
330 vnet_buffer (b[1])->l2.bd_index,
331 vnet_buffer (b[2])->l2.bd_index,
332 vnet_buffer (b[3])->l2.bd_index,
333 &key0, /* not used */
334 &key1, /* not used */
335 &key2, /* not used */
336 &key3, /* not used */
337 &bucket0, /* not used */
338 &bucket1, /* not used */
339 &bucket2, /* not used */
340 &bucket3, /* not used */
346 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
347 l2fwd_process (vm, node, msm, em, b[1], sw_if_index1, &result1,
349 l2fwd_process (vm, node, msm, em, b[2], sw_if_index2, &result2,
351 l2fwd_process (vm, node, msm, em, b[3], sw_if_index3, &result3,
354 /* verify speculative enqueues, maybe switch current next frame */
355 /* if next0==next1==next_index then nothing special needs to be done */
364 ethernet_header_t *h0;
365 l2fib_entry_key_t key0;
366 l2fib_entry_result_t result0;
369 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
371 h0 = vlib_buffer_get_current (b[0]);
373 if (do_trace && PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
375 l2fwd_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
376 t->sw_if_index = sw_if_index0;
377 t->bd_index = vnet_buffer (b[0])->l2.bd_index;
378 clib_memcpy (t->src, h0->src_address, 6);
379 clib_memcpy (t->dst, h0->dst_address, 6);
384 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
386 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result, h0->dst_address, vnet_buffer (b[0])->l2.bd_index, &key0, /* not used */
387 &bucket0, /* not used */
389 l2fwd_process (vm, node, msm, em, b[0], sw_if_index0, &result0, next);
391 /* verify speculative enqueue, maybe switch current next frame */
397 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
399 return frame->n_vectors;
402 VLIB_NODE_FN (l2fwd_node) (vlib_main_t * vm,
403 vlib_node_runtime_t * node, vlib_frame_t * frame)
405 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
406 return l2fwd_node_inline (vm, node, frame, 1 /* do_trace */ );
407 return l2fwd_node_inline (vm, node, frame, 0 /* do_trace */ );
411 VLIB_REGISTER_NODE (l2fwd_node,static) = {
413 .vector_size = sizeof (u32),
414 .format_trace = format_l2fwd_trace,
415 .type = VLIB_NODE_TYPE_INTERNAL,
417 .n_errors = ARRAY_LEN(l2fwd_error_strings),
418 .error_strings = l2fwd_error_strings,
420 .n_next_nodes = L2FWD_N_NEXT,
422 /* edit / add dispositions here */
424 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
425 [L2FWD_NEXT_DROP] = "error-drop",
430 #ifndef CLIB_MARCH_VARIANT
432 l2fwd_init (vlib_main_t * vm)
434 l2fwd_main_t *mp = &l2fwd_main;
437 mp->vnet_main = vnet_get_main ();
439 /* Initialize the feature next-node indexes */
440 feat_bitmap_init_next_nodes (vm,
443 l2input_get_feat_names (),
444 mp->feat_next_node_index);
446 /* init the hash table ptr */
447 mp->mac_table = get_mac_table ();
449 /* Initialize the next nodes for each ethertype */
450 next_by_ethertype_init (&mp->l3_next);
455 VLIB_INIT_FUNCTION (l2fwd_init);
458 /** Add the L3 input node for this ethertype to the next nodes structure. */
460 l2fwd_register_input_type (vlib_main_t * vm,
461 ethernet_type_t type, u32 node_index)
463 l2fwd_main_t *mp = &l2fwd_main;
466 next_index = vlib_node_add_next (vm, l2fwd_node.index, node_index);
468 next_by_ethertype_register (&mp->l3_next, type, next_index);
473 * Set subinterface forward enable/disable.
475 * set interface l2 forward <interface> [disable]
477 static clib_error_t *
478 int_fwd (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd)
480 vnet_main_t *vnm = vnet_get_main ();
481 clib_error_t *error = 0;
485 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
487 error = clib_error_return (0, "unknown interface `%U'",
488 format_unformat_error, input);
493 if (unformat (input, "disable"))
498 /* set the interface flag */
499 if (l2input_intf_config (sw_if_index)->xconnect)
501 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
505 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FWD, enable);
513 * Layer 2 unicast forwarding can be enabled and disabled on each
514 * interface and on each bridge-domain. Use this command to
515 * manage interfaces. It is enabled by default.
518 * Example of how to enable forwarding:
519 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0}
520 * Example of how to disable forwarding:
521 * @cliexcmd{set interface l2 forward GigabitEthernet0/8/0 disable}
524 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
525 .path = "set interface l2 forward",
526 .short_help = "set interface l2 forward <interface> [disable]",
534 * fd.io coding-style-patch-verification: ON
537 * eval: (c-set-style "gnu")