2 * l2_flood.c : layer 2 flooding
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>
23 #include <vnet/l2/l2_input.h>
24 #include <vnet/l2/feat_bitmap.h>
25 #include <vnet/l2/l2_bvi.h>
26 #include <vnet/replication.h>
27 #include <vnet/l2/l2_fib.h>
29 #include <vppinfra/error.h>
30 #include <vppinfra/hash.h>
34 * Flooding uses the packet replication infrastructure to send a copy of the
35 * packet to each member interface. Logically the replication infrastructure
36 * expects two graph nodes: a prep node that initiates replication and sends the
37 * packet to the first destination, and a recycle node that is passed the packet
38 * after it has been transmitted.
40 * To decrease the amount of code, l2 flooding implements both functions in
41 * the same graph node. This node can tell if is it being called as the "prep"
42 * or "recycle" using replication_is_recycled().
49 /* Next nodes for each feature */
50 u32 feat_next_node_index[32];
52 /* next node index for the L3 input node of each ethertype */
53 next_by_ethertype_t l3_next;
55 /* convenience variables */
56 vlib_main_t *vlib_main;
57 vnet_main_t *vnet_main;
69 /* packet trace format function */
71 format_l2flood_trace (u8 * s, va_list * args)
73 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
74 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
75 l2flood_trace_t *t = va_arg (*args, l2flood_trace_t *);
77 s = format (s, "l2-flood: sw_if_index %d dst %U src %U bd_index %d",
79 format_ethernet_address, t->dst,
80 format_ethernet_address, t->src, t->bd_index);
84 l2flood_main_t l2flood_main;
86 static vlib_node_registration_t l2flood_node;
88 #define foreach_l2flood_error \
89 _(L2FLOOD, "L2 flood packets") \
90 _(REPL_FAIL, "L2 replication failures") \
91 _(NO_MEMBERS, "L2 replication complete") \
92 _(BVI_BAD_MAC, "BVI L3 mac mismatch") \
93 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype")
97 #define _(sym,str) L2FLOOD_ERROR_##sym,
103 static char *l2flood_error_strings[] = {
104 #define _(sym,string) string,
105 foreach_l2flood_error
111 L2FLOOD_NEXT_L2_OUTPUT,
117 * Perform flooding on one packet
119 * Due to the way BVI processing can modify the packet, the BVI interface
120 * (if present) must be processed last in the replication. The member vector
121 * is arranged so that the BVI interface is always the first element.
122 * Flooding walks the vector in reverse.
124 * BVI processing causes the packet to go to L3 processing. This strips the
125 * L2 header, which is fine because the replication infrastructure restores
126 * it. However L3 processing can trigger larger changes to the packet. For
127 * example, an ARP request could be turned into an ARP reply, an ICMP request
128 * could be turned into an ICMP reply. If BVI processing is not performed
129 * last, the modified packet would be replicated to the remaining members.
132 static_always_inline void
133 l2flood_process (vlib_main_t * vm,
134 vlib_node_runtime_t * node,
135 l2flood_main_t * msm,
139 l2fib_entry_key_t * key0,
140 u32 * bucket0, l2fib_entry_result_t * result0, u32 * next0)
143 l2_bridge_domain_t *bd_config;
144 l2_flood_member_t *members;
145 i32 current_member; /* signed */
146 replication_context_t *ctx;
147 u8 in_shg = vnet_buffer (b0)->l2.shg;
149 if (!replication_is_recycled (b0))
152 /* Do flood "prep node" processing */
154 /* Get config for the bridge domain interface */
155 bd_index0 = vnet_buffer (b0)->l2.bd_index;
156 bd_config = vec_elt_at_index (l2input_main.bd_configs, bd_index0);
157 members = bd_config->members;
159 /* Find first member that passes the reflection and SHG checks */
160 current_member = vec_len (members) - 1;
161 while ((current_member >= 0) &&
162 ((members[current_member].sw_if_index == *sw_if_index0) ||
163 (in_shg && members[current_member].shg == in_shg)))
168 if (current_member < 0)
170 /* No members to flood to */
171 *next0 = L2FLOOD_NEXT_DROP;
172 b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS];
176 if ((current_member > 0) &&
177 ((current_member > 1) ||
178 ((members[0].sw_if_index != *sw_if_index0) &&
179 (!in_shg || members[0].shg != in_shg))))
181 /* If more than one member then initiate replication */
183 replication_prep (vm, b0, l2flood_node.index, 1 /* l2_packet */ );
184 ctx->feature_replicas = (uword) members;
185 ctx->feature_counter = current_member;
191 vnet_buffer_opaque_t *vnet_buff_op;
193 /* Do flood "recycle node" processing */
195 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_REPL_FAIL))
197 (void) replication_recycle (vm, b0, 1 /* is_last */ );
198 *next0 = L2FLOOD_NEXT_DROP;
199 b0->error = node->errors[L2FLOOD_ERROR_REPL_FAIL];
203 ctx = replication_get_ctx (b0);
204 replication_clear_recycled (b0);
206 members = (l2_flood_member_t *) (intptr_t) ctx->feature_replicas;
207 current_member = (i32) ctx->feature_counter - 1;
209 /* Need to update input index from saved packet context */
210 vnet_buff_op = (vnet_buffer_opaque_t *) ctx->vnet_buffer;
211 *sw_if_index0 = vnet_buff_op->sw_if_index[VLIB_RX];
213 /* Find next member that passes the reflection and SHG check */
214 while ((current_member >= 0) &&
215 ((members[current_member].sw_if_index == *sw_if_index0) ||
216 (in_shg && members[current_member].shg == in_shg)))
221 if (current_member < 0)
224 * No more members to flood to.
225 * Terminate replication and drop packet.
228 replication_recycle (vm, b0, 1 /* is_last */ );
230 *next0 = L2FLOOD_NEXT_DROP;
231 /* Ideally we woudn't bump a counter here, just silently complete */
232 b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS];
236 /* Restore packet and context and continue replication */
237 ctx->feature_counter = current_member;
238 replication_recycle (vm, b0, ((current_member == 0) || /*is_last */
239 ((current_member == 1) &&
240 ((members[0].sw_if_index ==
241 *sw_if_index0) || (in_shg
246 /* Forward packet to the current member */
248 if (PREDICT_TRUE (members[current_member].flags == L2_FLOOD_MEMBER_NORMAL))
250 /* Do normal L2 forwarding */
251 vnet_buffer (b0)->sw_if_index[VLIB_TX] =
252 members[current_member].sw_if_index;
253 *next0 = L2FLOOD_NEXT_L2_OUTPUT;
258 /* Do BVI processing */
263 members[current_member].sw_if_index,
264 &msm->l3_next, next0);
266 if (PREDICT_FALSE (rc))
268 if (rc == TO_BVI_ERR_BAD_MAC)
270 b0->error = node->errors[L2FLOOD_ERROR_BVI_BAD_MAC];
271 *next0 = L2FLOOD_NEXT_DROP;
273 else if (rc == TO_BVI_ERR_ETHERTYPE)
275 b0->error = node->errors[L2FLOOD_ERROR_BVI_ETHERTYPE];
276 *next0 = L2FLOOD_NEXT_DROP;
285 l2flood_node_fn (vlib_main_t * vm,
286 vlib_node_runtime_t * node, vlib_frame_t * frame)
288 u32 n_left_from, *from, *to_next;
289 l2flood_next_t next_index;
290 l2flood_main_t *msm = &l2flood_main;
291 vlib_node_t *n = vlib_get_node (vm, l2flood_node.index);
292 u32 node_counter_base_index = n->error_heap_index;
293 vlib_error_main_t *em = &vm->error_main;
295 from = vlib_frame_vector_args (frame);
296 n_left_from = frame->n_vectors; /* number of packets to process */
297 next_index = node->cached_next_index;
299 while (n_left_from > 0)
303 /* get space to enqueue frame to graph node "next_index" */
304 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
306 while (n_left_from >= 6 && n_left_to_next >= 2)
309 vlib_buffer_t *b0, *b1;
311 u32 sw_if_index0, sw_if_index1;
312 l2fib_entry_key_t key0, key1;
313 l2fib_entry_result_t result0, result1;
314 u32 bucket0, bucket1;
316 /* Prefetch next iteration. */
318 vlib_buffer_t *p2, *p3, *p4, *p5;
320 p2 = vlib_get_buffer (vm, from[2]);
321 p3 = vlib_get_buffer (vm, from[3]);
322 p4 = vlib_get_buffer (vm, from[4]);
323 p5 = vlib_get_buffer (vm, from[5]);
325 /* Prefetch the buffer header for the N+2 loop iteration */
326 vlib_prefetch_buffer_header (p4, LOAD);
327 vlib_prefetch_buffer_header (p5, LOAD);
329 /* Prefetch the replication context for the N+1 loop iteration */
330 /* This depends on the buffer header above */
331 replication_prefetch_ctx (p2);
332 replication_prefetch_ctx (p3);
334 /* Prefetch the packet for the N+1 loop iteration */
335 CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
336 CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
339 /* speculatively enqueue b0 and b1 to the current next frame */
340 /* bi is "buffer index", b is pointer to the buffer */
341 to_next[0] = bi0 = from[0];
342 to_next[1] = bi1 = from[1];
348 b0 = vlib_get_buffer (vm, bi0);
349 b1 = vlib_get_buffer (vm, bi1);
351 /* RX interface handles */
352 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
353 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
356 em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 2;
358 l2flood_process (vm, node, msm,
359 &em->counters[node_counter_base_index], b0,
360 &sw_if_index0, &key0, &bucket0, &result0, &next0);
362 l2flood_process (vm, node, msm,
363 &em->counters[node_counter_base_index], b1,
364 &sw_if_index1, &key1, &bucket1, &result1, &next1);
366 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
368 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
371 vlib_add_trace (vm, node, b0, sizeof (*t));
372 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
373 t->sw_if_index = sw_if_index0;
374 t->bd_index = vnet_buffer (b0)->l2.bd_index;
375 clib_memcpy (t->src, h0->src_address, 6);
376 clib_memcpy (t->dst, h0->dst_address, 6);
378 if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
381 vlib_add_trace (vm, node, b1, sizeof (*t));
382 ethernet_header_t *h1 = vlib_buffer_get_current (b1);
383 t->sw_if_index = sw_if_index1;
384 t->bd_index = vnet_buffer (b1)->l2.bd_index;
385 clib_memcpy (t->src, h1->src_address, 6);
386 clib_memcpy (t->dst, h1->dst_address, 6);
390 /* verify speculative enqueues, maybe switch current next frame */
391 /* if next0==next1==next_index then nothing special needs to be done */
392 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
393 to_next, n_left_to_next,
394 bi0, bi1, next0, next1);
397 while (n_left_from > 0 && n_left_to_next > 0)
403 l2fib_entry_key_t key0;
404 l2fib_entry_result_t result0;
407 /* speculatively enqueue b0 to the current next frame */
415 b0 = vlib_get_buffer (vm, bi0);
417 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
420 em->counters[node_counter_base_index + L2FLOOD_ERROR_L2FLOOD] += 1;
422 l2flood_process (vm, node, msm,
423 &em->counters[node_counter_base_index], b0,
424 &sw_if_index0, &key0, &bucket0, &result0, &next0);
426 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
427 (b0->flags & VLIB_BUFFER_IS_TRACED)))
429 l2flood_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
430 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
431 t->sw_if_index = sw_if_index0;
432 t->bd_index = vnet_buffer (b0)->l2.bd_index;
433 clib_memcpy (t->src, h0->src_address, 6);
434 clib_memcpy (t->dst, h0->dst_address, 6);
437 /* verify speculative enqueue, maybe switch current next frame */
438 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
439 to_next, n_left_to_next,
443 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
446 return frame->n_vectors;
451 VLIB_REGISTER_NODE (l2flood_node,static) = {
452 .function = l2flood_node_fn,
454 .vector_size = sizeof (u32),
455 .format_trace = format_l2flood_trace,
456 .type = VLIB_NODE_TYPE_INTERNAL,
458 .n_errors = ARRAY_LEN(l2flood_error_strings),
459 .error_strings = l2flood_error_strings,
461 .n_next_nodes = L2FLOOD_N_NEXT,
463 /* edit / add dispositions here */
465 [L2FLOOD_NEXT_L2_OUTPUT] = "l2-output",
466 [L2FLOOD_NEXT_DROP] = "error-drop",
471 VLIB_NODE_FUNCTION_MULTIARCH (l2flood_node, l2flood_node_fn)
472 clib_error_t *l2flood_init (vlib_main_t * vm)
474 l2flood_main_t *mp = &l2flood_main;
477 mp->vnet_main = vnet_get_main ();
479 /* Initialize the feature next-node indexes */
480 feat_bitmap_init_next_nodes (vm,
483 l2input_get_feat_names (),
484 mp->feat_next_node_index);
489 VLIB_INIT_FUNCTION (l2flood_init);
493 /** Add the L3 input node for this ethertype to the next nodes structure */
495 l2flood_register_input_type (vlib_main_t * vm,
496 ethernet_type_t type, u32 node_index)
498 l2flood_main_t *mp = &l2flood_main;
501 next_index = vlib_node_add_next (vm, l2flood_node.index, node_index);
503 next_by_ethertype_register (&mp->l3_next, type, next_index);
508 * set subinterface flood enable/disable
510 * set interface l2 flood <interface> [disable]
512 static clib_error_t *
513 int_flood (vlib_main_t * vm,
514 unformat_input_t * input, vlib_cli_command_t * cmd)
516 vnet_main_t *vnm = vnet_get_main ();
517 clib_error_t *error = 0;
521 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
523 error = clib_error_return (0, "unknown interface `%U'",
524 format_unformat_error, input);
529 if (unformat (input, "disable"))
534 /* set the interface flag */
535 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FLOOD, enable);
542 VLIB_CLI_COMMAND (int_flood_cli, static) = {
543 .path = "set interface l2 flood",
544 .short_help = "set interface l2 flood <interface> [disable]",
545 .function = int_flood,
550 * fd.io coding-style-patch-verification: ON
553 * eval: (c-set-style "gnu")