2 * l2_output.c : layer 2 output packet processing
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 <vppinfra/error.h>
25 #include <vppinfra/hash.h>
26 #include <vnet/l2/feat_bitmap.h>
27 #include <vnet/l2/l2_output.h>
30 // Feature graph node names
31 static char * l2output_feat_names[] = {
32 #define _(sym,name) name,
37 char **l2output_get_feat_names(void) {
38 return l2output_feat_names;
41 l2output_main_t l2output_main;
44 /* per-pkt trace data */
50 /* packet trace format function */
51 static u8 * format_l2output_trace (u8 * s, va_list * args)
53 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
54 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
55 l2output_trace_t * t = va_arg (*args, l2output_trace_t *);
57 s = format (s, "l2-output: sw_if_index %d dst %U src %U",
59 format_ethernet_address, t->dst,
60 format_ethernet_address, t->src);
65 #define foreach_l2output_error \
66 _(L2OUTPUT, "L2 output packets") \
67 _(EFP_DROP, "L2 EFP filter pre-rewrite drops") \
68 _(VTR_DROP, "L2 output tag rewrite drops") \
69 _(SHG_DROP, "L2 split horizon drops") \
70 _(DROP, "L2 output drops")
73 #define _(sym,str) L2OUTPUT_ERROR_##sym,
74 foreach_l2output_error
79 static char * l2output_error_strings[] = {
80 #define _(sym,string) string,
81 foreach_l2output_error
90 // Return 0 if split horizon check passes, otherwise return non-zero
91 // Packets should not be transmitted out an interface with the same
92 // split-horizon group as the input interface, except if the shg is 0
93 // in which case the check always passes.
94 static_always_inline u32
95 split_horizon_violation (u8 shg1, u8 shg2)
97 if (PREDICT_TRUE (shg1 == 0)) {
105 static vlib_node_registration_t l2output_node;
108 l2output_node_fn (vlib_main_t * vm,
109 vlib_node_runtime_t * node,
110 vlib_frame_t * frame)
112 u32 n_left_from, * from, * to_next;
113 l2output_next_t next_index;
114 l2output_main_t * msm = &l2output_main;
115 vlib_node_t *n = vlib_get_node (vm, l2output_node.index);
116 u32 node_counter_base_index = n->error_heap_index;
117 vlib_error_main_t * em = &vm->error_main;
118 u32 cached_sw_if_index;
119 u32 cached_next_index;
121 /* Invalidate cache */
122 cached_sw_if_index = ~0;
123 cached_next_index = ~0; /* warning be gone */
125 from = vlib_frame_vector_args (frame);
126 n_left_from = frame->n_vectors; /* number of packets to process */
127 next_index = node->cached_next_index;
129 while (n_left_from > 0)
133 /* get space to enqueue frame to graph node "next_index" */
134 vlib_get_next_frame (vm, node, next_index,
135 to_next, n_left_to_next);
137 while (n_left_from >= 6 && n_left_to_next >= 2)
140 vlib_buffer_t * b0, * b1;
142 u32 sw_if_index0, sw_if_index1;
143 ethernet_header_t * h0, * h1;
144 l2_output_config_t * config0, * config1;
145 u32 feature_bitmap0, feature_bitmap1;
147 /* Prefetch next iteration. */
149 vlib_buffer_t * p2, * p3, * p4 , * p5;
150 u32 sw_if_index2, sw_if_index3;
152 p2 = vlib_get_buffer (vm, from[2]);
153 p3 = vlib_get_buffer (vm, from[3]);
154 p4 = vlib_get_buffer (vm, from[4]);
155 p5 = vlib_get_buffer (vm, from[5]);
157 // Prefetch the buffer header for the N+2 loop iteration
158 vlib_prefetch_buffer_header (p4, LOAD);
159 vlib_prefetch_buffer_header (p5, LOAD);
160 // Note: no need to prefetch packet data. This node doesn't reference it.
162 // Prefetch the input config for the N+1 loop iteration
163 // This depends on the buffer header above
164 sw_if_index2 = vnet_buffer(p2)->sw_if_index[VLIB_TX];
165 sw_if_index3 = vnet_buffer(p3)->sw_if_index[VLIB_TX];
166 CLIB_PREFETCH (&msm->configs[sw_if_index2], CLIB_CACHE_LINE_BYTES, LOAD);
167 CLIB_PREFETCH (&msm->configs[sw_if_index3], CLIB_CACHE_LINE_BYTES, LOAD);
170 /* speculatively enqueue b0 and b1 to the current next frame */
171 /* bi is "buffer index", b is pointer to the buffer */
172 to_next[0] = bi0 = from[0];
173 to_next[1] = bi1 = from[1];
179 b0 = vlib_get_buffer (vm, bi0);
180 b1 = vlib_get_buffer (vm, bi1);
182 /* TX interface handles */
183 sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
184 sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_TX];
186 if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)))
188 h0 = vlib_buffer_get_current (b0);
189 h1 = vlib_buffer_get_current (b1);
190 if (b0->flags & VLIB_BUFFER_IS_TRACED)
192 l2output_trace_t *t =
193 vlib_add_trace (vm, node, b0, sizeof (*t));
194 t->sw_if_index = sw_if_index0;
195 clib_memcpy(t->src, h0->src_address, 6);
196 clib_memcpy(t->dst, h0->dst_address, 6);
198 if (b1->flags & VLIB_BUFFER_IS_TRACED)
200 l2output_trace_t *t =
201 vlib_add_trace (vm, node, b1, sizeof (*t));
202 t->sw_if_index = sw_if_index1;
203 clib_memcpy(t->src, h1->src_address, 6);
204 clib_memcpy(t->dst, h1->dst_address, 6);
208 em->counters[node_counter_base_index + L2OUTPUT_ERROR_L2OUTPUT] += 2;
210 // Get config for the output interface
211 config0 = vec_elt_at_index(msm->configs, sw_if_index0);
212 config1 = vec_elt_at_index(msm->configs, sw_if_index1);
214 // Get features from the config
215 // TODO: mask out any non-applicable features
216 feature_bitmap0 = config0->feature_bitmap;
217 feature_bitmap1 = config1->feature_bitmap;
219 // Determine next node
220 l2_output_dispatch (msm->vlib_main,
232 l2_output_dispatch (msm->vlib_main,
244 // Perform output vlan tag rewrite and the pre-vtr EFP filter check.
245 // The EFP Filter only needs to be run if there is an output VTR
246 // configured. The flag for the post-vtr EFP Filter node is used
247 // to trigger the pre-vtr check as well.
249 if (PREDICT_FALSE (config0->output_vtr.push_and_pop_bytes)) {
250 // Perform pre-vtr EFP filter check if configured
251 u32 failed1 = (feature_bitmap0 & L2OUTPUT_FEAT_EFP_FILTER) &&
252 (l2_efp_filter_process(b0, &(config0->input_vtr)));
253 u32 failed2 = l2_vtr_process(b0, &(config0->output_vtr));
255 if (PREDICT_FALSE (failed1 | failed2)) {
256 next0 = L2OUTPUT_NEXT_DROP;
258 b0->error = node->errors[L2OUTPUT_ERROR_VTR_DROP];
261 b0->error = node->errors[L2OUTPUT_ERROR_EFP_DROP];
266 if (PREDICT_FALSE (config1->output_vtr.push_and_pop_bytes)) {
267 // Perform pre-vtr EFP filter check if configured
268 u32 failed1 = (feature_bitmap1 & L2OUTPUT_FEAT_EFP_FILTER) &&
269 (l2_efp_filter_process(b1, &(config1->input_vtr)));
270 u32 failed2 = l2_vtr_process(b1, &(config1->output_vtr));
272 if (PREDICT_FALSE (failed1 | failed2)) {
273 next1 = L2OUTPUT_NEXT_DROP;
275 b1->error = node->errors[L2OUTPUT_ERROR_VTR_DROP];
278 b1->error = node->errors[L2OUTPUT_ERROR_EFP_DROP];
283 // Perform the split horizon check
284 // The check can only fail for non-zero shg's
285 if (PREDICT_FALSE (config0->shg + config1->shg)) {
286 // one of the checks might fail, check both
287 if (split_horizon_violation (config0->shg, vnet_buffer(b0)->l2.shg)) {
288 next0 = L2OUTPUT_NEXT_DROP;
289 b0->error = node->errors[L2OUTPUT_ERROR_SHG_DROP];
291 if (split_horizon_violation (config1->shg, vnet_buffer(b1)->l2.shg)) {
292 next1 = L2OUTPUT_NEXT_DROP;
293 b1->error = node->errors[L2OUTPUT_ERROR_SHG_DROP];
297 /* verify speculative enqueues, maybe switch current next frame */
298 /* if next0==next1==next_index then nothing special needs to be done */
299 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
300 to_next, n_left_to_next,
301 bi0, bi1, next0, next1);
304 while (n_left_from > 0 && n_left_to_next > 0)
310 ethernet_header_t * h0;
311 l2_output_config_t *config0;
314 /* speculatively enqueue b0 to the current next frame */
322 b0 = vlib_get_buffer (vm, bi0);
324 sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
326 if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
327 && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
328 l2output_trace_t *t =
329 vlib_add_trace (vm, node, b0, sizeof (*t));
330 t->sw_if_index = sw_if_index0;
331 h0 = vlib_buffer_get_current (b0);
332 clib_memcpy(t->src, h0->src_address, 6);
333 clib_memcpy(t->dst, h0->dst_address, 6);
336 em->counters[node_counter_base_index + L2OUTPUT_ERROR_L2OUTPUT] += 1;
338 // Get config for the output interface
339 config0 = vec_elt_at_index(msm->configs, sw_if_index0);
341 // Get features from the config
342 // TODO: mask out any non-applicable features
343 feature_bitmap0 = config0->feature_bitmap;
345 // Determine next node
346 l2_output_dispatch (msm->vlib_main,
358 // Perform output vlan tag rewrite and the pre-vtr EFP filter check.
359 // The EFP Filter only needs to be run if there is an output VTR
360 // configured. The flag for the post-vtr EFP Filter node is used
361 // to trigger the pre-vtr check as well.
363 if (config0->output_vtr.push_and_pop_bytes) {
364 // Perform pre-vtr EFP filter check if configured
365 u32 failed1 = (feature_bitmap0 & L2OUTPUT_FEAT_EFP_FILTER) &&
366 (l2_efp_filter_process(b0, &(config0->input_vtr)));
367 u32 failed2 = l2_vtr_process(b0, &(config0->output_vtr));
369 if (PREDICT_FALSE (failed1 | failed2)) {
370 next0 = L2OUTPUT_NEXT_DROP;
372 b0->error = node->errors[L2OUTPUT_ERROR_VTR_DROP];
375 b0->error = node->errors[L2OUTPUT_ERROR_EFP_DROP];
380 // Perform the split horizon check
381 if (PREDICT_FALSE (split_horizon_violation (config0->shg, vnet_buffer(b0)->l2.shg))) {
382 next0 = L2OUTPUT_NEXT_DROP;
383 b0->error = node->errors[L2OUTPUT_ERROR_SHG_DROP];
386 /* verify speculative enqueue, maybe switch current next frame */
387 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
388 to_next, n_left_to_next,
392 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
395 return frame->n_vectors;
399 VLIB_REGISTER_NODE (l2output_node,static) = {
400 .function = l2output_node_fn,
402 .vector_size = sizeof (u32),
403 .format_trace = format_l2output_trace,
404 .type = VLIB_NODE_TYPE_INTERNAL,
406 .n_errors = ARRAY_LEN(l2output_error_strings),
407 .error_strings = l2output_error_strings,
409 .n_next_nodes = L2OUTPUT_N_NEXT,
411 /* edit / add dispositions here */
413 [L2OUTPUT_NEXT_DROP] = "error-drop",
417 VLIB_NODE_FUNCTION_MULTIARCH (l2output_node, l2output_node_fn)
419 clib_error_t *l2output_init (vlib_main_t *vm)
421 l2output_main_t * mp = &l2output_main;
424 mp->vnet_main = vnet_get_main();
426 // Create the config vector
427 vec_validate(mp->configs, 100);
428 // Until we hook up the CLI config, just create 100 sw interface entries and zero them
430 // Initialize the feature next-node indexes
431 feat_bitmap_init_next_nodes(vm,
434 l2output_get_feat_names(),
435 mp->next_nodes.feat_next_node_index);
437 // Initialize the output node mapping table
438 l2output_init_output_node_vec(&mp->next_nodes.output_node_index_vec);
443 VLIB_INIT_FUNCTION (l2output_init);
448 } output_node_mapping_rpc_args_t;
451 static void output_node_rpc_callback
452 ( output_node_mapping_rpc_args_t * a);
454 static void output_node_mapping_send_rpc
458 output_node_mapping_rpc_args_t args;
459 void vl_api_rpc_call_main_thread (void *fp, u8 * data, u32 data_length);
461 args.node_index = node_index;
462 args.sw_if_index = sw_if_index;
464 vl_api_rpc_call_main_thread (output_node_rpc_callback,
465 (u8 *) &args, sizeof (args));
470 // Create a mapping in the next node mapping table for the given sw_if_index
471 u32 l2output_create_output_node_mapping (
472 vlib_main_t * vlib_main,
473 vnet_main_t * vnet_main,
474 u32 node_index, // index of current node
475 u32 * output_node_index_vec,
478 u32 next; // index of next graph node
479 vnet_hw_interface_t *hw0;
482 hw0 = vnet_get_sup_hw_interface (vnet_main, sw_if_index);
487 cpu_number = os_get_cpu_number();
493 oldflags = __sync_fetch_and_or(&hw0->flags,
494 VNET_HW_INTERFACE_FLAG_L2OUTPUT_MAPPED);
496 if ((oldflags & VNET_HW_INTERFACE_FLAG_L2OUTPUT_MAPPED) )
497 return L2OUTPUT_NEXT_DROP;
499 output_node_mapping_send_rpc (node_index, sw_if_index);
500 return L2OUTPUT_NEXT_DROP;
504 // dynamically create graph node arc
505 next = vlib_node_add_next (vlib_main,
507 hw0->output_node_index);
509 // Initialize vector with the mapping
511 node = vec_elt_at_index(output_node_index_vec, sw_if_index);
518 void output_node_rpc_callback (output_node_mapping_rpc_args_t *a)
520 vlib_main_t * vm = vlib_get_main();
521 vnet_main_t * vnm = vnet_get_main();
522 l2output_main_t * mp = &l2output_main;
524 (void) l2output_create_output_node_mapping
525 (vm, vnm, a->node_index, mp->next_nodes.output_node_index_vec,
530 // Get a pointer to the config for the given interface
531 l2_output_config_t * l2output_intf_config (u32 sw_if_index)
533 l2output_main_t * mp = &l2output_main;
535 vec_validate(mp->configs, sw_if_index);
536 return vec_elt_at_index(mp->configs, sw_if_index);
539 // Enable (or disable) the feature in the bitmap for the given interface
540 void l2output_intf_bitmap_enable (u32 sw_if_index,
544 l2output_main_t * mp = &l2output_main;
545 l2_output_config_t *config;
547 vec_validate(mp->configs, sw_if_index);
548 config = vec_elt_at_index(mp->configs, sw_if_index);
551 config->feature_bitmap |= feature_bitmap;
553 config->feature_bitmap &= ~feature_bitmap;