2 * l2_efp_filter.c : layer 2 egress EFP Filter 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/ethernet/ethernet.h>
21 #include <vnet/ethernet/packet.h>
22 #include <vnet/l2/feat_bitmap.h>
23 #include <vnet/l2/l2_output.h>
24 #include <vnet/ethernet/ethernet.h>
25 #include <vnet/l2/l2_efp_filter.h>
27 #include <vppinfra/error.h>
28 #include <vppinfra/cache.h>
32 * @brief EFP-filter - Ethernet Flow Point Filter.
34 * It is possible to transmit a packet out a subinterface with VLAN tags
35 * that are not compatible with that subinterface. In other words, if that
36 * packet arrived on the output port, it would not be classified as coming
37 * from the output subinterface. This can happen in various ways: through
38 * misconfiguration, by putting subinterfaces with different VLAN encaps in
39 * the same bridge-domain, etc. The EFP Filter Check detects such packets
40 * and drops them. It consists of two checks, one that verifies the packet
41 * prior to output VLAN tag rewrite and one that verifies the packet after
47 /* Next nodes for L2 output features */
48 u32 l2_out_feat_next[32];
50 /* convenience variables */
51 vlib_main_t *vlib_main;
52 vnet_main_t *vnet_main;
53 } l2_efp_filter_main_t;
58 /* per-pkt trace data */
61 u8 raw[12]; /* raw data (vlans) */
63 } l2_efp_filter_trace_t;
65 /* packet trace format function */
67 format_l2_efp_filter_trace (u8 * s, va_list * args)
69 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
70 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
71 l2_efp_filter_trace_t *t = va_arg (*args, l2_efp_filter_trace_t *);
73 s = format (s, "l2-output-vtr: sw_if_index %d dst %U src %U data "
74 "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
76 format_ethernet_address, t->dst,
77 format_ethernet_address, t->src,
78 t->raw[0], t->raw[1], t->raw[2], t->raw[3], t->raw[4],
79 t->raw[5], t->raw[6], t->raw[7], t->raw[8], t->raw[9],
80 t->raw[10], t->raw[11]);
84 extern l2_efp_filter_main_t l2_efp_filter_main;
86 #ifndef CLIB_MARCH_VARIANT
87 l2_efp_filter_main_t l2_efp_filter_main;
88 #endif /* CLIB_MARCH_VARIANT */
90 #define foreach_l2_efp_filter_error \
91 _(L2_EFP_FILTER, "L2 EFP filter packets") \
92 _(DROP, "L2 EFP filter post-rewrite drops")
96 #define _(sym,str) L2_EFP_FILTER_ERROR_##sym,
97 foreach_l2_efp_filter_error
99 L2_EFP_FILTER_N_ERROR,
100 } l2_efp_filter_error_t;
102 static char *l2_efp_filter_error_strings[] = {
103 #define _(sym,string) string,
104 foreach_l2_efp_filter_error
110 L2_EFP_FILTER_NEXT_DROP,
111 L2_EFP_FILTER_N_NEXT,
112 } l2_efp_filter_next_t;
116 * Extract fields from the packet that will be used in interface
119 static_always_inline void
120 extract_keys (vnet_main_t * vnet_main,
123 u32 * port_sw_if_index0,
124 u16 * first_ethertype0,
125 u16 * outer_id0, u16 * inner_id0, u32 * match_flags0)
127 ethernet_header_t *e0;
128 ethernet_vlan_header_t *h0;
133 vnet_get_sup_sw_interface (vnet_main, sw_if_index0)->sw_if_index;
135 e0 = vlib_buffer_get_current (b0);
136 h0 = (ethernet_vlan_header_t *) (e0 + 1);
138 *first_ethertype0 = clib_net_to_host_u16 (e0->type);
139 *outer_id0 = clib_net_to_host_u16 (h0[0].priority_cfi_and_id);
140 *inner_id0 = clib_net_to_host_u16 (h0[1].priority_cfi_and_id);
142 tag_len = vnet_buffer (b0)->l2.l2_len - sizeof (ethernet_header_t);
143 tag_num = tag_len / sizeof (ethernet_vlan_header_t);
144 *match_flags0 = eth_create_valid_subint_match_flags (tag_num);
148 * EFP filtering is a basic switch feature which prevents an interface from
149 * transmitting a packet that doesn't match the interface's ingress match
150 * criteria. The check has two parts, one performed before egress vlan tag
151 * rewrite and one after.
153 * The pre-rewrite check insures the packet matches what an ingress packet looks
154 * like after going through the interface's ingress tag rewrite operation. Only
155 * pushed tags are compared. So:
156 * - if the ingress vlan tag rewrite pushes no tags (or is not enabled),
157 * any packet passes the filter
158 * - if the ingress vlan tag rewrite pushes one tag,
159 * the packet must have at least one tag, and the outer tag must match the pushed tag
160 * - if the ingress vlan tag rewrite pushes two tags,
161 * the packet must have at least two tags, and the outer two tags must match the pushed tags
163 * The pre-rewrite check is performed in the l2-output node.
165 * The post-rewrite check insures the packet matches what an ingress packet looks
166 * like before going through the interface's ingress tag rewrite operation. It verifies
167 * that such a packet arriving on the wire at this port would be classified as arriving
168 * an input interface equal to the packet's output interface. This can be done by running
169 * the output packet's vlan tags and output port through the interface classification,
170 * and checking if the resulting interface matches the output interface.
172 * The post-rewrite check is performed here.
175 VLIB_NODE_FN (l2_efp_filter_node) (vlib_main_t * vm,
176 vlib_node_runtime_t * node,
177 vlib_frame_t * frame)
179 u32 n_left_from, *from, *to_next;
180 l2_efp_filter_next_t next_index;
181 l2_efp_filter_main_t *msm = &l2_efp_filter_main;
182 vlib_node_t *n = vlib_get_node (vm, l2_efp_filter_node.index);
183 u32 node_counter_base_index = n->error_heap_index;
184 vlib_error_main_t *em = &vm->error_main;
186 from = vlib_frame_vector_args (frame);
187 n_left_from = frame->n_vectors; /* number of packets to process */
188 next_index = node->cached_next_index;
190 while (n_left_from > 0)
194 /* get space to enqueue frame to graph node "next_index" */
195 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
197 while (n_left_from >= 6 && n_left_to_next >= 2)
200 vlib_buffer_t *b0, *b1;
202 u32 sw_if_index0, sw_if_index1;
203 u16 first_ethertype0, first_ethertype1;
204 u16 outer_id0, inner_id0, outer_id1, inner_id1;
205 u32 match_flags0, match_flags1;
206 u32 port_sw_if_index0, subint_sw_if_index0, port_sw_if_index1,
208 vnet_hw_interface_t *hi0, *hi1;
209 main_intf_t *main_intf0, *main_intf1;
210 vlan_intf_t *vlan_intf0, *vlan_intf1;
211 qinq_intf_t *qinq_intf0, *qinq_intf1;
213 __attribute__ ((unused)) u32 matched0, matched1;
216 /* Prefetch next iteration. */
218 vlib_buffer_t *p2, *p3, *p4, *p5;
219 __attribute__ ((unused)) u32 sw_if_index2, sw_if_index3;
221 p2 = vlib_get_buffer (vm, from[2]);
222 p3 = vlib_get_buffer (vm, from[3]);
223 p4 = vlib_get_buffer (vm, from[4]);
224 p5 = vlib_get_buffer (vm, from[5]);
226 /* Prefetch the buffer header and packet for the N+2 loop iteration */
227 vlib_prefetch_buffer_header (p4, LOAD);
228 vlib_prefetch_buffer_header (p5, LOAD);
230 CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
231 CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
234 * Prefetch the input config for the N+1 loop iteration
235 * This depends on the buffer header above
237 sw_if_index2 = vnet_buffer (p2)->sw_if_index[VLIB_TX];
238 sw_if_index3 = vnet_buffer (p3)->sw_if_index[VLIB_TX];
241 * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index2), CLIB_CACHE_LINE_BYTES, LOAD);
242 * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index3), CLIB_CACHE_LINE_BYTES, LOAD);
246 /* speculatively enqueue b0 and b1 to the current next frame */
247 /* bi is "buffer index", b is pointer to the buffer */
248 to_next[0] = bi0 = from[0];
249 to_next[1] = bi1 = from[1];
255 b0 = vlib_get_buffer (vm, bi0);
256 b1 = vlib_get_buffer (vm, bi1);
258 /* TX interface handles */
259 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
260 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX];
262 /* process 2 packets */
263 em->counters[node_counter_base_index +
264 L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 2;
266 /* Determine next node */
267 next0 = vnet_l2_feature_next (b0, msm->l2_out_feat_next,
268 L2OUTPUT_FEAT_EFP_FILTER);
269 next1 = vnet_l2_feature_next (b1, msm->l2_out_feat_next,
270 L2OUTPUT_FEAT_EFP_FILTER);
272 /* perform the efp filter check on two packets */
274 extract_keys (msm->vnet_main,
279 &outer_id0, &inner_id0, &match_flags0);
281 extract_keys (msm->vnet_main,
286 &outer_id1, &inner_id1, &match_flags1);
288 eth_vlan_table_lookups (ðernet_main,
295 &main_intf0, &vlan_intf0, &qinq_intf0);
297 eth_vlan_table_lookups (ðernet_main,
304 &main_intf1, &vlan_intf1, &qinq_intf1);
306 matched0 = eth_identify_subint (hi0,
311 &subint_sw_if_index0,
314 matched1 = eth_identify_subint (hi1,
319 &subint_sw_if_index1,
322 if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
325 next0 = L2_EFP_FILTER_NEXT_DROP;
326 b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
329 if (PREDICT_FALSE (sw_if_index1 != subint_sw_if_index1))
332 next1 = L2_EFP_FILTER_NEXT_DROP;
333 b1->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
336 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
338 if (b0->flags & VLIB_BUFFER_IS_TRACED)
340 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
341 l2_efp_filter_trace_t *t =
342 vlib_add_trace (vm, node, b0, sizeof (*t));
343 t->sw_if_index = sw_if_index0;
344 clib_memcpy_fast (t->src, h0->src_address, 6);
345 clib_memcpy_fast (t->dst, h0->dst_address, 6);
346 clib_memcpy_fast (t->raw, &h0->type, sizeof (t->raw));
348 if (b1->flags & VLIB_BUFFER_IS_TRACED)
350 ethernet_header_t *h1 = vlib_buffer_get_current (b1);
351 l2_efp_filter_trace_t *t =
352 vlib_add_trace (vm, node, b1, sizeof (*t));
353 t->sw_if_index = sw_if_index1;
354 clib_memcpy_fast (t->src, h1->src_address, 6);
355 clib_memcpy_fast (t->dst, h1->dst_address, 6);
356 clib_memcpy_fast (t->raw, &h1->type, sizeof (t->raw));
360 /* verify speculative enqueues, maybe switch current next frame */
361 /* if next0==next1==next_index then nothing special needs to be done */
362 vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
363 to_next, n_left_to_next,
364 bi0, bi1, next0, next1);
367 while (n_left_from > 0 && n_left_to_next > 0)
373 u16 first_ethertype0;
374 u16 outer_id0, inner_id0;
376 u32 port_sw_if_index0, subint_sw_if_index0;
377 vnet_hw_interface_t *hi0;
378 main_intf_t *main_intf0;
379 vlan_intf_t *vlan_intf0;
380 qinq_intf_t *qinq_intf0;
382 __attribute__ ((unused)) u32 matched0;
385 /* speculatively enqueue b0 to the current next frame */
393 b0 = vlib_get_buffer (vm, bi0);
394 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
396 /* process 1 packet */
397 em->counters[node_counter_base_index +
398 L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 1;
400 /* Determine next node */
401 next0 = vnet_l2_feature_next (b0, msm->l2_out_feat_next,
402 L2OUTPUT_FEAT_EFP_FILTER);
404 /* perform the efp filter check on one packet */
406 extract_keys (msm->vnet_main,
411 &outer_id0, &inner_id0, &match_flags0);
413 eth_vlan_table_lookups (ðernet_main,
420 &main_intf0, &vlan_intf0, &qinq_intf0);
422 matched0 = eth_identify_subint (hi0,
427 &subint_sw_if_index0,
430 if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
433 next0 = L2_EFP_FILTER_NEXT_DROP;
434 b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
437 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
438 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
440 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
441 l2_efp_filter_trace_t *t =
442 vlib_add_trace (vm, node, b0, sizeof (*t));
443 t->sw_if_index = sw_if_index0;
444 clib_memcpy_fast (t->src, h0->src_address, 6);
445 clib_memcpy_fast (t->dst, h0->dst_address, 6);
446 clib_memcpy_fast (t->raw, &h0->type, sizeof (t->raw));
449 /* verify speculative enqueue, maybe switch current next frame */
450 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
451 to_next, n_left_to_next,
455 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
458 return frame->n_vectors;
463 VLIB_REGISTER_NODE (l2_efp_filter_node) = {
464 .name = "l2-efp-filter",
465 .vector_size = sizeof (u32),
466 .format_trace = format_l2_efp_filter_trace,
467 .type = VLIB_NODE_TYPE_INTERNAL,
469 .n_errors = ARRAY_LEN(l2_efp_filter_error_strings),
470 .error_strings = l2_efp_filter_error_strings,
472 .n_next_nodes = L2_EFP_FILTER_N_NEXT,
474 /* edit / add dispositions here */
476 [L2_EFP_FILTER_NEXT_DROP] = "error-drop",
481 #ifndef CLIB_MARCH_VARIANT
483 l2_efp_filter_init (vlib_main_t * vm)
485 l2_efp_filter_main_t *mp = &l2_efp_filter_main;
488 mp->vnet_main = vnet_get_main ();
490 /* Initialize the feature next-node indexes */
491 feat_bitmap_init_next_nodes (vm,
492 l2_efp_filter_node.index,
494 l2output_get_feat_names (),
495 mp->l2_out_feat_next);
500 VLIB_INIT_FUNCTION (l2_efp_filter_init);
503 /** Enable/disable the EFP Filter check on the subinterface. */
505 l2_efp_filter_configure (vnet_main_t * vnet_main, u32 sw_if_index, u8 enable)
507 /* set the interface flag */
508 l2output_intf_bitmap_enable (sw_if_index, L2OUTPUT_FEAT_EFP_FILTER, enable);
513 * Set subinterface egress efp filter enable/disable.
515 * set interface l2 efp-filter <interface> [disable]]
517 static clib_error_t *
518 int_l2_efp_filter (vlib_main_t * vm,
519 unformat_input_t * input, vlib_cli_command_t * cmd)
521 vnet_main_t *vnm = vnet_get_main ();
522 clib_error_t *error = 0;
526 if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
528 error = clib_error_return (0, "unknown interface `%U'",
529 format_unformat_error, input);
534 if (unformat (input, "disable"))
539 /* enable/disable the feature */
540 l2_efp_filter_configure (vnm, sw_if_index, enable);
548 * EFP filtering is a basic switch feature which prevents an interface from
549 * transmitting a packet that doesn't match the interface's ingress match
550 * criteria. The check has two parts, one performed before egress vlan tag
551 * rewrite and one after. This command enables or disables the EFP filtering
552 * for a given sub-interface.
555 * Example of how to enable a Layer 2 efp-filter on a sub-interface:
556 * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200}
557 * Example of how to disable a Layer 2 efp-filter on a sub-interface:
558 * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200 disable}
561 VLIB_CLI_COMMAND (int_l2_efp_filter_cli, static) = {
562 .path = "set interface l2 efp-filter",
563 .short_help = "set interface l2 efp-filter <interface> [disable]",
564 .function = int_l2_efp_filter,
568 #endif /* CLIB_MARCH_VARIANT */
571 * fd.io coding-style-patch-verification: ON
574 * eval: (c-set-style "gnu")