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/l2/l2_fib.h>
28 #include <vppinfra/error.h>
29 #include <vppinfra/hash.h>
34 * @brief Ethernet Flooding.
36 * Flooding uses the packet replication infrastructure to send a copy of the
37 * packet to each member interface. Logically the replication infrastructure
38 * expects two graph nodes: a prep node that initiates replication and sends the
39 * packet to the first destination, and a recycle node that is passed the packet
40 * after it has been transmitted.
42 * To decrease the amount of code, l2 flooding implements both functions in
43 * the same graph node. This node can tell if is it being called as the "prep"
44 * or "recycle" using replication_is_recycled().
51 /* Next nodes for each feature */
52 u32 feat_next_node_index[32];
54 /* next node index for the L3 input node of each ethertype */
55 next_by_ethertype_t l3_next;
57 /* convenience variables */
58 vlib_main_t *vlib_main;
59 vnet_main_t *vnet_main;
61 /* per-cpu vector of cloned packets */
63 l2_flood_member_t ***members;
75 /* packet trace format function */
77 format_l2flood_trace (u8 * s, va_list * args)
79 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
80 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
81 l2flood_trace_t *t = va_arg (*args, l2flood_trace_t *);
83 s = format (s, "l2-flood: sw_if_index %d dst %U src %U bd_index %d",
85 format_ethernet_address, t->dst,
86 format_ethernet_address, t->src, t->bd_index);
90 l2flood_main_t l2flood_main;
92 static vlib_node_registration_t l2flood_node;
94 #define foreach_l2flood_error \
95 _(L2FLOOD, "L2 flood packets") \
96 _(REPL_FAIL, "L2 replication failures") \
97 _(NO_MEMBERS, "L2 replication complete") \
98 _(BVI_BAD_MAC, "BVI L3 mac mismatch") \
99 _(BVI_ETHERTYPE, "BVI packet with unhandled ethertype")
103 #define _(sym,str) L2FLOOD_ERROR_##sym,
104 foreach_l2flood_error
109 static char *l2flood_error_strings[] = {
110 #define _(sym,string) string,
111 foreach_l2flood_error
117 L2FLOOD_NEXT_L2_OUTPUT,
123 * Perform flooding on one packet
125 * Due to the way BVI processing can modify the packet, the BVI interface
126 * (if present) must be processed last in the replication. The member vector
127 * is arranged so that the BVI interface is always the first element.
128 * Flooding walks the vector in reverse.
130 * BVI processing causes the packet to go to L3 processing. This strips the
131 * L2 header, which is fine because the replication infrastructure restores
132 * it. However L3 processing can trigger larger changes to the packet. For
133 * example, an ARP request could be turned into an ARP reply, an ICMP request
134 * could be turned into an ICMP reply. If BVI processing is not performed
135 * last, the modified packet would be replicated to the remaining members.
138 l2flood_node_fn (vlib_main_t * vm,
139 vlib_node_runtime_t * node, vlib_frame_t * frame)
141 u32 n_left_from, *from, *to_next;
142 l2flood_next_t next_index;
143 l2flood_main_t *msm = &l2flood_main;
144 u32 thread_index = vm->thread_index;
146 from = vlib_frame_vector_args (frame);
147 n_left_from = frame->n_vectors;
148 next_index = node->cached_next_index;
150 while (n_left_from > 0)
154 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
156 while (n_left_from > 0 && n_left_to_next > 0)
158 u32 next0, sw_if_index0, bi0, ci0;
159 u16 n_clones, n_cloned, clone0;
160 l2_bridge_domain_t *bd_config;
161 l2_flood_member_t *member;
162 vlib_buffer_t *b0, *c0;
166 /* speculatively enqueue b0 to the current next frame */
170 next0 = L2FLOOD_NEXT_L2_OUTPUT;
172 b0 = vlib_get_buffer (vm, bi0);
174 /* Get config for the bridge domain interface */
175 bd_config = vec_elt_at_index (l2input_main.bd_configs,
176 vnet_buffer (b0)->l2.bd_index);
177 in_shg = vnet_buffer (b0)->l2.shg;
178 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
180 vec_validate (msm->members[thread_index],
181 vec_len (bd_config->members));
183 vec_reset_length (msm->members[thread_index]);
185 /* Find first members that passes the reflection and SHG checks */
186 for (mi = bd_config->flood_count - 1; mi >= 0; mi--)
188 member = &bd_config->members[mi];
189 if ((member->sw_if_index != sw_if_index0) &&
190 (!in_shg || (member->shg != in_shg)))
192 vec_add1 (msm->members[thread_index], member);
196 n_clones = vec_len (msm->members[thread_index]);
200 /* No members to flood to */
205 b0->error = node->errors[L2FLOOD_ERROR_NO_MEMBERS];
206 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
207 to_next, n_left_to_next,
208 bi0, L2FLOOD_NEXT_DROP);
212 vec_validate (msm->clones[thread_index], n_clones);
213 vec_reset_length (msm->clones[thread_index]);
216 * the header offset needs to be large enoguh to incorporate
217 * all the L3 headers that could be touched when doing BVI
218 * processing. So take the current l2 length plus 2 * IPv6
219 * headers (for tunnel encap)
221 n_cloned = vlib_buffer_clone (vm, bi0,
222 msm->clones[thread_index],
224 (vnet_buffer (b0)->l2.l2_len +
225 sizeof (udp_header_t) +
226 2 * sizeof (ip6_header_t)));
228 if (PREDICT_FALSE (n_cloned != n_clones))
230 b0->error = node->errors[L2FLOOD_ERROR_REPL_FAIL];
234 * for all but the last clone, these are not BVI bound
236 for (clone0 = 0; clone0 < n_cloned - 1; clone0++)
238 member = msm->members[thread_index][clone0];
239 ci0 = msm->clones[thread_index][clone0];
240 c0 = vlib_get_buffer (vm, ci0);
246 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
247 (b0->flags & VLIB_BUFFER_IS_TRACED)))
249 ethernet_header_t *h0;
253 vlib_buffer_copy_trace_flag (vm, b0, ci0);
255 t = vlib_add_trace (vm, node, c0, sizeof (*t));
256 h0 = vlib_buffer_get_current (c0);
257 t->sw_if_index = sw_if_index0;
258 t->bd_index = vnet_buffer (c0)->l2.bd_index;
259 clib_memcpy (t->src, h0->src_address, 6);
260 clib_memcpy (t->dst, h0->dst_address, 6);
263 /* Do normal L2 forwarding */
264 vnet_buffer (c0)->sw_if_index[VLIB_TX] = member->sw_if_index;
266 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
267 to_next, n_left_to_next,
269 if (PREDICT_FALSE (0 == n_left_to_next))
271 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
272 vlib_get_next_frame (vm, node, next_index,
273 to_next, n_left_to_next);
278 * the last clone that might go to a BVI
280 member = msm->members[thread_index][clone0];
281 ci0 = msm->clones[thread_index][clone0];
282 c0 = vlib_get_buffer (vm, ci0);
288 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
289 (b0->flags & VLIB_BUFFER_IS_TRACED)))
291 ethernet_header_t *h0;
295 vlib_buffer_copy_trace_flag (vm, b0, ci0);
297 t = vlib_add_trace (vm, node, c0, sizeof (*t));
298 h0 = vlib_buffer_get_current (c0);
299 t->sw_if_index = sw_if_index0;
300 t->bd_index = vnet_buffer (c0)->l2.bd_index;
301 clib_memcpy (t->src, h0->src_address, 6);
302 clib_memcpy (t->dst, h0->dst_address, 6);
306 /* Forward packet to the current member */
307 if (PREDICT_FALSE (member->flags & L2_FLOOD_MEMBER_BVI))
309 /* Do BVI processing */
313 c0, member->sw_if_index, &msm->l3_next, &next0);
315 if (PREDICT_FALSE (rc != TO_BVI_ERR_OK))
317 if (rc == TO_BVI_ERR_BAD_MAC)
319 c0->error = node->errors[L2FLOOD_ERROR_BVI_BAD_MAC];
321 else if (rc == TO_BVI_ERR_ETHERTYPE)
323 c0->error = node->errors[L2FLOOD_ERROR_BVI_ETHERTYPE];
325 next0 = L2FLOOD_NEXT_DROP;
330 /* Do normal L2 forwarding */
331 vnet_buffer (c0)->sw_if_index[VLIB_TX] = member->sw_if_index;
334 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
335 to_next, n_left_to_next,
337 if (PREDICT_FALSE (0 == n_left_to_next))
339 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
340 vlib_get_next_frame (vm, node, next_index,
341 to_next, n_left_to_next);
345 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
348 vlib_node_increment_counter (vm, node->node_index,
349 L2FLOOD_ERROR_L2FLOOD, frame->n_vectors);
351 return frame->n_vectors;
356 VLIB_REGISTER_NODE (l2flood_node,static) = {
357 .function = l2flood_node_fn,
359 .vector_size = sizeof (u32),
360 .format_trace = format_l2flood_trace,
361 .type = VLIB_NODE_TYPE_INTERNAL,
363 .n_errors = ARRAY_LEN(l2flood_error_strings),
364 .error_strings = l2flood_error_strings,
366 .n_next_nodes = L2FLOOD_N_NEXT,
368 /* edit / add dispositions here */
370 [L2FLOOD_NEXT_L2_OUTPUT] = "l2-output",
371 [L2FLOOD_NEXT_DROP] = "error-drop",
376 VLIB_NODE_FUNCTION_MULTIARCH (l2flood_node, l2flood_node_fn)
377 clib_error_t *l2flood_init (vlib_main_t * vm)
379 l2flood_main_t *mp = &l2flood_main;
382 mp->vnet_main = vnet_get_main ();
384 vec_validate (mp->clones, vlib_num_workers ());
385 vec_validate (mp->members, vlib_num_workers ());
387 /* Initialize the feature next-node indexes */
388 feat_bitmap_init_next_nodes (vm,
391 l2input_get_feat_names (),
392 mp->feat_next_node_index);
397 VLIB_INIT_FUNCTION (l2flood_init);
401 /** Add the L3 input node for this ethertype to the next nodes structure. */
403 l2flood_register_input_type (vlib_main_t * vm,
404 ethernet_type_t type, u32 node_index)
406 l2flood_main_t *mp = &l2flood_main;
409 next_index = vlib_node_add_next (vm, l2flood_node.index, node_index);
411 next_by_ethertype_register (&mp->l3_next, type, next_index);
416 * Set subinterface flood enable/disable.
418 * set interface l2 flood <interface> [disable]
420 static clib_error_t *
421 int_flood (vlib_main_t * vm,
422 unformat_input_t * input, vlib_cli_command_t * cmd)
424 vnet_main_t *vnm = vnet_get_main ();
425 clib_error_t *error = 0;
429 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
431 error = clib_error_return (0, "unknown interface `%U'",
432 format_unformat_error, input);
437 if (unformat (input, "disable"))
442 /* set the interface flag */
443 l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_FLOOD, enable);
450 * Layer 2 flooding can be enabled and disabled on each
451 * interface and on each bridge-domain. Use this command to
452 * manage interfaces. It is enabled by default.
455 * Example of how to enable flooding:
456 * @cliexcmd{set interface l2 flood GigabitEthernet0/8/0}
457 * Example of how to disable flooding:
458 * @cliexcmd{set interface l2 flood GigabitEthernet0/8/0 disable}
461 VLIB_CLI_COMMAND (int_flood_cli, static) = {
462 .path = "set interface l2 flood",
463 .short_help = "set interface l2 flood <interface> [disable]",
464 .function = int_flood,
469 * fd.io coding-style-patch-verification: ON
472 * eval: (c-set-style "gnu")