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>
37 BVT(clib_bihash) *mac_table;
39 // next node index for the L3 input node of each ethertype
40 next_by_ethertype_t l3_next;
42 /* convenience variables */
43 vlib_main_t * vlib_main;
44 vnet_main_t * vnet_main;
48 /* per-pkt trace data */
55 /* packet trace format function */
56 static u8 * format_l2fwd_trace (u8 * s, va_list * args)
58 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
59 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
60 l2fwd_trace_t * t = va_arg (*args, l2fwd_trace_t *);
62 s = format (s, "l2-fwd: sw_if_index %d dst %U src %U bd_index %d",
64 format_ethernet_address, t->dst,
65 format_ethernet_address, t->src,
70 l2fwd_main_t l2fwd_main;
72 static vlib_node_registration_t l2fwd_node;
74 #define foreach_l2fwd_error \
75 _(L2FWD, "L2 forward packets") \
76 _(FLOOD, "L2 forward misses") \
77 _(HIT, "L2 forward hits") \
78 _(BVI_TAGGED, "BVI packet with vlan tag") \
79 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype") \
80 _(FILTER_DROP, "Filter Mac Drop") \
81 _(REFLECT_DROP, "Reflection Drop")
84 #define _(sym,str) L2FWD_ERROR_##sym,
90 static char * l2fwd_error_strings[] = {
91 #define _(sym,string) string,
103 // Forward one packet based on the mac table lookup result
105 static_always_inline void
106 l2fwd_process (vlib_main_t * vm,
107 vlib_node_runtime_t * node,
109 vlib_error_main_t * em,
112 l2fib_entry_result_t * result0,
115 if (PREDICT_FALSE (result0->raw == ~0)) {
116 // lookup miss, so flood
117 // TODO:replicate packet to each intf in bridge-domain
119 if (vnet_buffer(b0)->l2.feature_bitmap & L2INPUT_FEAT_UU_FLOOD) {
120 *next0 = L2FWD_NEXT_FLOOD;
122 // Flooding is disabled
123 b0->error = node->errors[L2FWD_ERROR_FLOOD];
124 *next0 = L2FWD_NEXT_DROP;
129 // lookup hit, forward packet
131 em->counters[node_counter_base_index + L2FWD_ERROR_HIT] += 1;
134 vnet_buffer(b0)->sw_if_index[VLIB_TX] = result0->fields.sw_if_index;
135 *next0 = L2FWD_NEXT_L2_OUTPUT;
137 // perform reflection check
138 if (PREDICT_FALSE (sw_if_index0 == result0->fields.sw_if_index)) {
139 b0->error = node->errors[L2FWD_ERROR_REFLECT_DROP];
140 *next0 = L2FWD_NEXT_DROP;
142 // perform filter check
143 } else if (PREDICT_FALSE (result0->fields.filter)) {
144 b0->error = node->errors[L2FWD_ERROR_FILTER_DROP];
145 *next0 = L2FWD_NEXT_DROP;
148 } else if (PREDICT_FALSE (result0->fields.bvi)) {
153 vnet_buffer(b0)->sw_if_index[VLIB_TX],
157 if (PREDICT_FALSE(rc)) {
158 if (rc == TO_BVI_ERR_TAGGED) {
159 b0->error = node->errors[L2FWD_ERROR_BVI_TAGGED];
160 *next0 = L2FWD_NEXT_DROP;
161 } else if (rc == TO_BVI_ERR_ETHERTYPE) {
162 b0->error = node->errors[L2FWD_ERROR_BVI_ETHERTYPE];
163 *next0 = L2FWD_NEXT_DROP;
172 l2fwd_node_fn (vlib_main_t * vm,
173 vlib_node_runtime_t * node,
174 vlib_frame_t * frame)
176 u32 n_left_from, * from, * to_next;
177 l2fwd_next_t next_index;
178 l2fwd_main_t * msm = &l2fwd_main;
179 vlib_node_t *n = vlib_get_node (vm, l2fwd_node.index);
180 CLIB_UNUSED(u32 node_counter_base_index) = n->error_heap_index;
181 vlib_error_main_t * em = &vm->error_main;
182 l2fib_entry_key_t cached_key;
183 l2fib_entry_result_t cached_result;
185 // Clear the one-entry cache in case mac table was updated
187 cached_result.raw = ~0;
189 from = vlib_frame_vector_args (frame);
190 n_left_from = frame->n_vectors; /* number of packets to process */
191 next_index = node->cached_next_index;
193 while (n_left_from > 0)
197 /* get space to enqueue frame to graph node "next_index" */
198 vlib_get_next_frame (vm, node, next_index,
199 to_next, n_left_to_next);
201 while (n_left_from >= 4 && n_left_to_next >= 2)
204 vlib_buffer_t * b0, * b1;
206 u32 sw_if_index0, sw_if_index1;
207 ethernet_header_t * h0, * h1;
208 l2fib_entry_key_t key0, key1;
209 l2fib_entry_result_t result0, result1;
210 u32 bucket0, bucket1;
212 /* Prefetch next iteration. */
214 vlib_buffer_t * p2, * p3;
216 p2 = vlib_get_buffer (vm, from[2]);
217 p3 = vlib_get_buffer (vm, from[3]);
219 vlib_prefetch_buffer_header (p2, LOAD);
220 vlib_prefetch_buffer_header (p3, LOAD);
222 CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
223 CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
226 /* speculatively enqueue b0 and b1 to the current next frame */
227 /* bi is "buffer index", b is pointer to the buffer */
228 to_next[0] = bi0 = from[0];
229 to_next[1] = bi1 = from[1];
235 b0 = vlib_get_buffer (vm, bi0);
236 b1 = vlib_get_buffer (vm, bi1);
238 /* RX interface handles */
239 sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
240 sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
242 h0 = vlib_buffer_get_current (b0);
243 h1 = vlib_buffer_get_current (b1);
245 if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)))
247 if (b0->flags & VLIB_BUFFER_IS_TRACED)
250 vlib_add_trace (vm, node, b0, sizeof (*t));
251 t->sw_if_index = sw_if_index0;
252 t->bd_index = vnet_buffer(b0)->l2.bd_index;
253 clib_memcpy(t->src, h0->src_address, 6);
254 clib_memcpy(t->dst, h0->dst_address, 6);
256 if (b1->flags & VLIB_BUFFER_IS_TRACED)
259 vlib_add_trace (vm, node, b1, sizeof (*t));
260 t->sw_if_index = sw_if_index1;
261 t->bd_index = vnet_buffer(b1)->l2.bd_index;
262 clib_memcpy(t->src, h1->src_address, 6);
263 clib_memcpy(t->dst, h1->dst_address, 6);
269 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 2;
271 l2fib_lookup_2 (msm->mac_table, &cached_key, &cached_result,
274 vnet_buffer(b0)->l2.bd_index,
275 vnet_buffer(b1)->l2.bd_index,
278 &bucket0, // not used
279 &bucket1, // not used
282 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0, &next0);
283 l2fwd_process (vm, node, msm, em, b1, sw_if_index1, &result1, &next1);
285 /* verify speculative enqueues, maybe switch current next frame */
286 /* if next0==next1==next_index then nothing special needs to be done */
287 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
288 to_next, n_left_to_next,
289 bi0, bi1, next0, next1);
292 while (n_left_from > 0 && n_left_to_next > 0)
298 ethernet_header_t * h0;
299 l2fib_entry_key_t key0;
300 l2fib_entry_result_t result0;
303 /* speculatively enqueue b0 to the current next frame */
311 b0 = vlib_get_buffer (vm, bi0);
313 sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
315 h0 = vlib_buffer_get_current (b0);
317 if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
318 && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
320 vlib_add_trace (vm, node, b0, sizeof (*t));
321 t->sw_if_index = sw_if_index0;
322 t->bd_index = vnet_buffer(b0)->l2.bd_index;
323 clib_memcpy(t->src, h0->src_address, 6);
324 clib_memcpy(t->dst, h0->dst_address, 6);
329 em->counters[node_counter_base_index + L2FWD_ERROR_L2FWD] += 1;
331 l2fib_lookup_1 (msm->mac_table, &cached_key, &cached_result,
332 h0->dst_address, vnet_buffer(b0)->l2.bd_index,
334 &bucket0, // not used
336 l2fwd_process (vm, node, msm, em, b0, sw_if_index0, &result0, &next0);
338 /* verify speculative enqueue, maybe switch current next frame */
339 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
340 to_next, n_left_to_next,
344 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
347 return frame->n_vectors;
350 VLIB_REGISTER_NODE (l2fwd_node,static) = {
351 .function = l2fwd_node_fn,
353 .vector_size = sizeof (u32),
354 .format_trace = format_l2fwd_trace,
355 .type = VLIB_NODE_TYPE_INTERNAL,
357 .n_errors = ARRAY_LEN(l2fwd_error_strings),
358 .error_strings = l2fwd_error_strings,
360 .n_next_nodes = L2FWD_N_NEXT,
362 /* edit / add dispositions here */
364 [L2FWD_NEXT_L2_OUTPUT] = "l2-output",
365 [L2FWD_NEXT_FLOOD] = "l2-flood",
366 [L2FWD_NEXT_DROP] = "error-drop",
370 VLIB_NODE_FUNCTION_MULTIARCH (l2fwd_node, l2fwd_node_fn)
372 clib_error_t *l2fwd_init (vlib_main_t *vm)
374 l2fwd_main_t * mp = &l2fwd_main;
377 mp->vnet_main = vnet_get_main();
379 /* init the hash table ptr */
380 mp->mac_table = get_mac_table();
382 // Initialize the next nodes for each ethertype
383 next_by_ethertype_init (&mp->l3_next);
388 VLIB_INIT_FUNCTION (l2fwd_init);
391 // Add the L3 input node for this ethertype to the next nodes structure
393 l2fwd_register_input_type (vlib_main_t * vm,
394 ethernet_type_t type,
397 l2fwd_main_t * mp = &l2fwd_main;
400 next_index = vlib_node_add_next (vm,
404 next_by_ethertype_register (&mp->l3_next, type, next_index);
408 // set subinterface forward enable/disable
409 // The CLI format is:
410 // set interface l2 forward <interface> [disable]
411 static clib_error_t *
412 int_fwd (vlib_main_t * vm,
413 unformat_input_t * input,
414 vlib_cli_command_t * cmd)
416 vnet_main_t * vnm = vnet_get_main();
417 clib_error_t * error = 0;
421 if (! unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
423 error = clib_error_return (0, "unknown interface `%U'",
424 format_unformat_error, input);
429 if (unformat (input, "disable")) {
433 // set the interface flag
434 if (l2input_intf_config(sw_if_index)->xconnect) {
435 l2input_intf_bitmap_enable(sw_if_index, L2INPUT_FEAT_XCONNECT, enable);
437 l2input_intf_bitmap_enable(sw_if_index, L2INPUT_FEAT_FWD, enable);
444 VLIB_CLI_COMMAND (int_fwd_cli, static) = {
445 .path = "set interface l2 forward",
446 .short_help = "set interface l2 forward <interface> [disable]",