2 * l2_input.c : layer 2 input 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>
22 #include <vnet/ethernet/packet.h>
23 #include <vnet/ip/ip4.h>
24 #include <vnet/ip/ip6.h>
25 #include <vnet/fib/fib_node.h>
26 #include <vnet/ethernet/arp_packet.h>
28 #include <vnet/l2/l2_input.h>
29 #include <vnet/l2/l2_output.h>
30 #include <vnet/l2/feat_bitmap.h>
31 #include <vnet/l2/l2_bvi.h>
32 #include <vnet/l2/l2_fib.h>
33 #include <vnet/l2/l2_bd.h>
35 #include <vppinfra/error.h>
36 #include <vppinfra/hash.h>
37 #include <vppinfra/cache.h>
41 * @brief Interface Input Mode (Layer 2 Cross-Connect or Bridge / Layer 3).
43 * This file contains the CLI Commands that modify the input mode of an
44 * interface. For interfaces in a Layer 2 cross-connect, all packets
45 * received on one interface will be transmitted to the other. For
46 * interfaces in a bridge-domain, packets will be forwarded to other
47 * interfaces in the same bridge-domain based on destination mac address.
48 * For interfaces in Layer 3 mode, the packets will be routed.
53 /* per-pkt trace data */
59 /* packet trace format function */
61 format_l2input_trace (u8 * s, va_list * args)
63 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
64 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
65 l2input_trace_t *t = va_arg (*args, l2input_trace_t *);
67 s = format (s, "l2-input: sw_if_index %d dst %U src %U [%U]",
69 format_ethernet_address, t->dst_and_src,
70 format_ethernet_address, t->dst_and_src + 6,
71 format_l2_input_feature_bitmap, t->feat_mask, 0);
75 extern l2input_main_t l2input_main;
77 #ifndef CLIB_MARCH_VARIANT
78 l2input_main_t l2input_main;
79 #endif /* CLIB_MARCH_VARIANT */
81 #define foreach_l2input_error \
82 _(L2INPUT, "L2 input packets") \
83 _(DROP, "L2 input drops")
87 #define _(sym,str) L2INPUT_ERROR_##sym,
93 static char *l2input_error_strings[] = {
94 #define _(sym,string) string,
107 static_always_inline void
108 classify_and_dispatch (l2input_main_t * msm, vlib_buffer_t * b0, u16 * next0)
111 * Load L2 input feature struct
112 * Load bridge domain struct
113 * Parse ethernet header to determine unicast/mcast/broadcast
115 * classify packet as IP/UDP/TCP, control, other
116 * mask feature bitmap
117 * go to first node in bitmap
118 * Later: optimize VTM
121 * set tx sw-if-handle
125 u32 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
126 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
128 /* Get config for the input interface */
129 l2_input_config_t *config = vec_elt_at_index (msm->configs, sw_if_index0);
131 /* Save split horizon group */
132 vnet_buffer (b0)->l2.shg = config->shg;
134 /* determine layer2 kind for stat and mask */
135 if (PREDICT_FALSE (ethernet_address_cast (h0->dst_address)))
137 u8 *l3h0 = (u8 *) h0 + vnet_buffer (b0)->l2.l2_len;
139 #define get_u16(addr) ( *((u16 *)(addr)) )
140 u16 ethertype = clib_net_to_host_u16 (get_u16 (l3h0 - 2));
141 u8 protocol = ((ip6_header_t *) l3h0)->protocol;
143 /* Disable bridge forwarding (flooding will execute instead if not xconnect) */
144 feat_mask &= ~(L2INPUT_FEAT_FWD |
145 L2INPUT_FEAT_UU_FLOOD |
146 L2INPUT_FEAT_UU_FWD | L2INPUT_FEAT_GBP_FWD);
148 if (ethertype != ETHERNET_TYPE_ARP)
149 feat_mask &= ~(L2INPUT_FEAT_ARP_UFWD);
151 /* Disable ARP-term for non-ARP and non-ICMP6 packet */
152 if (ethertype != ETHERNET_TYPE_ARP &&
153 (ethertype != ETHERNET_TYPE_IP6 || protocol != IP_PROTOCOL_ICMP6))
154 feat_mask &= ~(L2INPUT_FEAT_ARP_TERM);
156 * For packet from BVI - set SHG of ARP request or ICMPv6 neighbor
157 * solicitation packet from BVI to 0 so it can also flood to VXLAN
158 * tunnels or other ports with the same SHG as that of the BVI.
160 else if (PREDICT_FALSE (vnet_buffer (b0)->sw_if_index[VLIB_TX] ==
163 if (ethertype == ETHERNET_TYPE_ARP)
165 ethernet_arp_header_t *arp0 = (ethernet_arp_header_t *) l3h0;
167 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request))
168 vnet_buffer (b0)->l2.shg = 0;
170 else /* must be ICMPv6 */
172 ip6_header_t *iph0 = (ip6_header_t *) l3h0;
173 icmp6_neighbor_solicitation_or_advertisement_header_t *ndh0;
174 ndh0 = ip6_next_header (iph0);
175 if (ndh0->icmp.type == ICMP6_neighbor_solicitation)
176 vnet_buffer (b0)->l2.shg = 0;
183 * For packet from BVI - set SHG of unicast packet from BVI to 0 so it
184 * is not dropped on output to VXLAN tunnels or other ports with the
185 * same SHG as that of the BVI.
187 if (PREDICT_FALSE (vnet_buffer (b0)->sw_if_index[VLIB_TX] ==
189 vnet_buffer (b0)->l2.shg = 0;
193 if (l2_input_is_bridge (config))
195 /* Do bridge-domain processing */
196 /* save BD ID for next feature graph nodes */
197 vnet_buffer (b0)->l2.bd_index = config->bd_index;
199 /* Save bridge domain and interface seq_num */
200 vnet_buffer (b0)->l2.l2fib_sn = l2_fib_mk_seq_num
201 (config->bd_seq_num, config->seq_num);
202 vnet_buffer (b0)->l2.bd_age = config->bd_mac_age;
205 * Process bridge domain feature enables.
206 * To perform learning/flooding/forwarding, the corresponding bit
207 * must be enabled in both the input interface config and in the
208 * bridge domain config. In the bd_bitmap, bits for features other
209 * than learning/flooding/forwarding should always be set.
211 feat_mask = feat_mask & config->bd_feature_bitmap;
213 else if (l2_input_is_xconnect (config))
215 /* Set the output interface */
216 vnet_buffer (b0)->sw_if_index[VLIB_TX] = config->output_sw_if_index;
219 feat_mask = L2INPUT_FEAT_DROP;
221 /* mask out features from bitmap using packet type and bd config */
222 u32 feature_bitmap = config->feature_bitmap & feat_mask;
224 /* save for next feature graph nodes */
225 vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap;
227 /* Determine the next node */
228 *next0 = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
232 static_always_inline uword
233 l2input_node_inline (vlib_main_t * vm,
234 vlib_node_runtime_t * node, vlib_frame_t * frame,
238 l2input_main_t *msm = &l2input_main;
239 vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
240 u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
242 from = vlib_frame_vector_args (frame);
243 n_left = frame->n_vectors; /* number of packets to process */
245 vlib_get_buffers (vm, from, bufs, n_left);
251 u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
253 /* Prefetch next iteration. */
255 /* Prefetch the buffer header and packet for the N+2 loop iteration */
256 vlib_prefetch_buffer_header (b[4], LOAD);
257 vlib_prefetch_buffer_header (b[5], LOAD);
258 vlib_prefetch_buffer_header (b[6], LOAD);
259 vlib_prefetch_buffer_header (b[7], LOAD);
261 CLIB_PREFETCH (b[4]->data, CLIB_CACHE_LINE_BYTES, STORE);
262 CLIB_PREFETCH (b[5]->data, CLIB_CACHE_LINE_BYTES, STORE);
263 CLIB_PREFETCH (b[6]->data, CLIB_CACHE_LINE_BYTES, STORE);
264 CLIB_PREFETCH (b[7]->data, CLIB_CACHE_LINE_BYTES, STORE);
267 classify_and_dispatch (msm, b[0], &next[0]);
268 classify_and_dispatch (msm, b[1], &next[1]);
269 classify_and_dispatch (msm, b[2], &next[2]);
270 classify_and_dispatch (msm, b[3], &next[3]);
274 /* RX interface handles */
275 sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
276 sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
277 sw_if_index2 = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
278 sw_if_index3 = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
280 if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
282 ethernet_header_t *h0 = vlib_buffer_get_current (b[0]);
284 vlib_add_trace (vm, node, b[0], sizeof (*t));
285 t->sw_if_index = sw_if_index0;
286 t->feat_mask = vnet_buffer (b[0])->l2.feature_bitmap;
287 clib_memcpy_fast (t->dst_and_src, h0->dst_address,
288 sizeof (h0->dst_address) +
289 sizeof (h0->src_address));
291 if (b[1]->flags & VLIB_BUFFER_IS_TRACED)
293 ethernet_header_t *h1 = vlib_buffer_get_current (b[1]);
295 vlib_add_trace (vm, node, b[1], sizeof (*t));
296 t->sw_if_index = sw_if_index1;
297 t->feat_mask = vnet_buffer (b[1])->l2.feature_bitmap;
298 clib_memcpy_fast (t->dst_and_src, h1->dst_address,
299 sizeof (h1->dst_address) +
300 sizeof (h1->src_address));
302 if (b[2]->flags & VLIB_BUFFER_IS_TRACED)
304 ethernet_header_t *h2 = vlib_buffer_get_current (b[2]);
306 vlib_add_trace (vm, node, b[2], sizeof (*t));
307 t->sw_if_index = sw_if_index2;
308 t->feat_mask = vnet_buffer (b[2])->l2.feature_bitmap;
309 clib_memcpy_fast (t->dst_and_src, h2->dst_address,
310 sizeof (h2->dst_address) +
311 sizeof (h2->src_address));
313 if (b[3]->flags & VLIB_BUFFER_IS_TRACED)
315 ethernet_header_t *h3 = vlib_buffer_get_current (b[3]);
317 vlib_add_trace (vm, node, b[3], sizeof (*t));
318 t->sw_if_index = sw_if_index3;
319 t->feat_mask = vnet_buffer (b[3])->l2.feature_bitmap;
320 clib_memcpy_fast (t->dst_and_src, h3->dst_address,
321 sizeof (h3->dst_address) +
322 sizeof (h3->src_address));
333 classify_and_dispatch (msm, b[0], &next[0]);
335 if (do_trace && PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
337 ethernet_header_t *h0 = vlib_buffer_get_current (b[0]);
339 vlib_add_trace (vm, node, b[0], sizeof (*t));
340 t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
341 t->feat_mask = vnet_buffer (b[0])->l2.feature_bitmap;
342 clib_memcpy_fast (t->dst_and_src, h0->dst_address,
343 sizeof (h0->dst_address) +
344 sizeof (h0->src_address));
353 vlib_node_increment_counter (vm, l2input_node.index,
354 L2INPUT_ERROR_L2INPUT, frame->n_vectors);
356 vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
358 return frame->n_vectors;
361 VLIB_NODE_FN (l2input_node) (vlib_main_t * vm,
362 vlib_node_runtime_t * node, vlib_frame_t * frame)
364 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
365 return l2input_node_inline (vm, node, frame, 1 /* do_trace */ );
366 return l2input_node_inline (vm, node, frame, 0 /* do_trace */ );
370 VLIB_REGISTER_NODE (l2input_node) = {
372 .vector_size = sizeof (u32),
373 .format_trace = format_l2input_trace,
374 .format_buffer = format_ethernet_header_with_length,
375 .type = VLIB_NODE_TYPE_INTERNAL,
377 .n_errors = ARRAY_LEN(l2input_error_strings),
378 .error_strings = l2input_error_strings,
380 .n_next_nodes = L2INPUT_N_NEXT,
382 /* edit / add dispositions here */
384 [L2INPUT_NEXT_LEARN] = "l2-learn",
385 [L2INPUT_NEXT_FWD] = "l2-fwd",
386 [L2INPUT_NEXT_DROP] = "error-drop",
392 * fd.io coding-style-patch-verification: ON
395 * eval: (c-set-style "gnu")