vnet/vnet/l2/l2_efp_filter.c

   1 /*
   2  * l2_efp_filter.c : layer 2 egress EFP Filter processing
   3  *
   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:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  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.
  16  */
  17
  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
  26 #include <vppinfra/error.h>
  27 #include <vppinfra/cache.h>
  28
  29 /**
  30  * @file
  31  * @brief EFP-filter - Ethernet Flow Point Filter.
  32  *
  33  * It is possible to transmit a packet out a subinterface with VLAN tags
  34  * that are not compatible with that subinterface. In other words, if that
  35  * packet arrived on the output port, it would not be classified as coming
  36  * from the output subinterface. This can happen in various ways: through
  37  * misconfiguration, by putting subinterfaces with different VLAN encaps in
  38  * the same bridge-domain, etc. The EFP Filter Check detects such packets
  39  * and drops them. It consists of two checks, one that verifies the packet
  40  * prior to output VLAN tag rewrite and one that verifies the packet after
  41  * VLAN tag rewrite.
  42  *
  43  */
  44 typedef struct
  45 {
  46
  47   /* Next nodes for features and output interfaces */
  48   l2_output_next_nodes_st next_nodes;
  49
  50   /* convenience variables */
  51   vlib_main_t *vlib_main;
  52   vnet_main_t *vnet_main;
  53 } l2_efp_filter_main_t;
  54
  55
  56 typedef struct
  57 {
  58   /* per-pkt trace data */
  59   u8 src[6];
  60   u8 dst[6];
  61   u8 raw[12];                   /* raw data (vlans) */
  62   u32 sw_if_index;
  63 } l2_efp_filter_trace_t;
  64
  65 /* packet trace format function */
  66 static u8 *
  67 format_l2_efp_filter_trace (u8 * s, va_list * args)
  68 {
  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 *);
  72
  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",
  75               t->sw_if_index,
  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]);
  81   return s;
  82 }
  83
  84 l2_efp_filter_main_t l2_efp_filter_main;
  85
  86 static vlib_node_registration_t l2_efp_filter_node;
  87
  88 #define foreach_l2_efp_filter_error                     \
  89 _(L2_EFP_FILTER, "L2 EFP filter packets")               \
  90 _(DROP,          "L2 EFP filter post-rewrite drops")
  91
  92 typedef enum
  93 {
  94 #define _(sym,str) L2_EFP_FILTER_ERROR_##sym,
  95   foreach_l2_efp_filter_error
  96 #undef _
  97     L2_EFP_FILTER_N_ERROR,
  98 } l2_efp_filter_error_t;
  99
 100 static char *l2_efp_filter_error_strings[] = {
 101 #define _(sym,string) string,
 102   foreach_l2_efp_filter_error
 103 #undef _
 104 };
 105
 106 typedef enum
 107 {
 108   L2_EFP_FILTER_NEXT_DROP,
 109   L2_EFP_FILTER_N_NEXT,
 110 } l2_efp_filter_next_t;
 111
 112
 113 /**
 114  *  Extract fields from the packet that will be used in interface
 115  *  classification.
 116  */
 117 static_always_inline void
 118 extract_keys (vnet_main_t * vnet_main,
 119               u32 sw_if_index0,
 120               vlib_buffer_t * b0,
 121               u32 * port_sw_if_index0,
 122               u16 * first_ethertype0,
 123               u16 * outer_id0, u16 * inner_id0, u32 * match_flags0)
 124 {
 125   ethernet_header_t *e0;
 126   ethernet_vlan_header_t *h0;
 127   u32 tag_len;
 128   u32 tag_num;
 129
 130   *port_sw_if_index0 =
 131     vnet_get_sup_sw_interface (vnet_main, sw_if_index0)->sw_if_index;
 132
 133   e0 = vlib_buffer_get_current (b0);
 134   h0 = (ethernet_vlan_header_t *) (e0 + 1);
 135
 136   *first_ethertype0 = clib_net_to_host_u16 (e0->type);
 137   *outer_id0 = clib_net_to_host_u16 (h0[0].priority_cfi_and_id);
 138   *inner_id0 = clib_net_to_host_u16 (h0[1].priority_cfi_and_id);
 139
 140   tag_len = vnet_buffer (b0)->l2.l2_len - sizeof (ethernet_header_t);
 141   tag_num = tag_len / sizeof (ethernet_vlan_header_t);
 142   *match_flags0 = eth_create_valid_subint_match_flags (tag_num);
 143 }
 144
 145 /*
 146  * EFP filtering is a basic switch feature which prevents an interface from
 147  * transmitting a packet that doesn't match the interface's ingress match
 148  * criteria. The check has two parts, one performed before egress vlan tag
 149  * rewrite and one after.
 150  *
 151  * The pre-rewrite check insures the packet matches what an ingress packet looks
 152  * like after going through the interface's ingress tag rewrite operation. Only
 153  * pushed tags are compared. So:
 154  * - if the ingress vlan tag rewrite pushes no tags (or is not enabled),
 155  *   any packet passes the filter
 156  * - if the ingress vlan tag rewrite pushes one tag,
 157  *   the packet must have at least one tag, and the outer tag must match the pushed tag
 158  * - if the ingress vlan tag rewrite pushes two tags,
 159  *   the packet must have at least two tags, and the outer two tags must match the pushed tags
 160  *
 161  * The pre-rewrite check is performed in the l2-output node.
 162  *
 163  * The post-rewrite check insures the packet matches what an ingress packet looks
 164  * like before going through the interface's ingress tag rewrite operation. It verifies
 165  * that such a packet arriving on the wire at this port would be classified as arriving
 166  * an input interface equal to the packet's output interface. This can be done by running
 167  * the output packet's vlan tags and output port through the interface classification,
 168  * and checking if the resulting interface matches the output interface.
 169  *
 170  * The post-rewrite check is performed here.
 171  */
 172
 173 static uword
 174 l2_efp_filter_node_fn (vlib_main_t * vm,
 175                        vlib_node_runtime_t * node, vlib_frame_t * frame)
 176 {
 177   u32 n_left_from, *from, *to_next;
 178   l2_efp_filter_next_t next_index;
 179   l2_efp_filter_main_t *msm = &l2_efp_filter_main;
 180   vlib_node_t *n = vlib_get_node (vm, l2_efp_filter_node.index);
 181   u32 node_counter_base_index = n->error_heap_index;
 182   vlib_error_main_t *em = &vm->error_main;
 183   u32 cached_sw_if_index = ~0;
 184   u32 cached_next_index = ~0;
 185
 186   /* invalidate cache to begin with */
 187   cached_sw_if_index = ~0;
 188
 189   from = vlib_frame_vector_args (frame);
 190   n_left_from = frame->n_vectors;       /* number of packets to process */
 191   next_index = node->cached_next_index;
 192
 193   while (n_left_from > 0)
 194     {
 195       u32 n_left_to_next;
 196
 197       /* get space to enqueue frame to graph node "next_index" */
 198       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 199
 200       while (n_left_from >= 6 && n_left_to_next >= 2)
 201         {
 202           u32 bi0, bi1;
 203           vlib_buffer_t *b0, *b1;
 204           u32 next0, next1;
 205           u32 sw_if_index0, sw_if_index1;
 206           u32 feature_bitmap0, feature_bitmap1;
 207           u16 first_ethertype0, first_ethertype1;
 208           u16 outer_id0, inner_id0, outer_id1, inner_id1;
 209           u32 match_flags0, match_flags1;
 210           u32 port_sw_if_index0, subint_sw_if_index0, port_sw_if_index1,
 211             subint_sw_if_index1;
 212           vnet_hw_interface_t *hi0, *hi1;
 213           main_intf_t *main_intf0, *main_intf1;
 214           vlan_intf_t *vlan_intf0, *vlan_intf1;
 215           qinq_intf_t *qinq_intf0, *qinq_intf1;
 216           u32 is_l20, is_l21;
 217           __attribute__ ((unused)) u32 matched0, matched1;
 218           u8 error0, error1;
 219
 220           /* Prefetch next iteration. */
 221           {
 222             vlib_buffer_t *p2, *p3, *p4, *p5;
 223             __attribute__ ((unused)) u32 sw_if_index2, sw_if_index3;
 224
 225             p2 = vlib_get_buffer (vm, from[2]);
 226             p3 = vlib_get_buffer (vm, from[3]);
 227             p4 = vlib_get_buffer (vm, from[4]);
 228             p5 = vlib_get_buffer (vm, from[5]);
 229
 230             /* Prefetch the buffer header and packet for the N+2 loop iteration */
 231             vlib_prefetch_buffer_header (p4, LOAD);
 232             vlib_prefetch_buffer_header (p5, LOAD);
 233
 234             CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
 235             CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
 236
 237             /*
 238              * Prefetch the input config for the N+1 loop iteration
 239              * This depends on the buffer header above
 240              */
 241             sw_if_index2 = vnet_buffer (p2)->sw_if_index[VLIB_TX];
 242             sw_if_index3 = vnet_buffer (p3)->sw_if_index[VLIB_TX];
 243             /*
 244              * $$$ TODO
 245              * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index2), CLIB_CACHE_LINE_BYTES, LOAD);
 246              * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index3), CLIB_CACHE_LINE_BYTES, LOAD);
 247              */
 248           }
 249
 250           /* speculatively enqueue b0 and b1 to the current next frame */
 251           /* bi is "buffer index", b is pointer to the buffer */
 252           to_next[0] = bi0 = from[0];
 253           to_next[1] = bi1 = from[1];
 254           from += 2;
 255           to_next += 2;
 256           n_left_from -= 2;
 257           n_left_to_next -= 2;
 258
 259           b0 = vlib_get_buffer (vm, bi0);
 260           b1 = vlib_get_buffer (vm, bi1);
 261
 262           /* TX interface handles */
 263           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 264           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX];
 265
 266           /* process 2 packets */
 267           em->counters[node_counter_base_index +
 268                        L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 2;
 269
 270           /* Remove ourself from the feature bitmap */
 271           feature_bitmap0 =
 272             vnet_buffer (b0)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 273           feature_bitmap1 =
 274             vnet_buffer (b1)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 275
 276           /* Determine next node */
 277           l2_output_dispatch (msm->vlib_main,
 278                               msm->vnet_main,
 279                               node,
 280                               l2_efp_filter_node.index,
 281                               &cached_sw_if_index,
 282                               &cached_next_index,
 283                               &msm->next_nodes,
 284                               b0, sw_if_index0, feature_bitmap0, &next0);
 285           l2_output_dispatch (msm->vlib_main,
 286                               msm->vnet_main,
 287                               node,
 288                               l2_efp_filter_node.index,
 289                               &cached_sw_if_index,
 290                               &cached_next_index,
 291                               &msm->next_nodes,
 292                               b1, sw_if_index1, feature_bitmap1, &next1);
 293
 294           /* perform the efp filter check on two packets */
 295
 296           extract_keys (msm->vnet_main,
 297                         sw_if_index0,
 298                         b0,
 299                         &port_sw_if_index0,
 300                         &first_ethertype0,
 301                         &outer_id0, &inner_id0, &match_flags0);
 302
 303           extract_keys (msm->vnet_main,
 304                         sw_if_index1,
 305                         b1,
 306                         &port_sw_if_index1,
 307                         &first_ethertype1,
 308                         &outer_id1, &inner_id1, &match_flags1);
 309
 310           eth_vlan_table_lookups (&ethernet_main,
 311                                   msm->vnet_main,
 312                                   port_sw_if_index0,
 313                                   first_ethertype0,
 314                                   outer_id0,
 315                                   inner_id0,
 316                                   &hi0,
 317                                   &main_intf0, &vlan_intf0, &qinq_intf0);
 318
 319           eth_vlan_table_lookups (&ethernet_main,
 320                                   msm->vnet_main,
 321                                   port_sw_if_index1,
 322                                   first_ethertype1,
 323                                   outer_id1,
 324                                   inner_id1,
 325                                   &hi1,
 326                                   &main_intf1, &vlan_intf1, &qinq_intf1);
 327
 328           matched0 = eth_identify_subint (hi0,
 329                                           b0,
 330                                           match_flags0,
 331                                           main_intf0,
 332                                           vlan_intf0,
 333                                           qinq_intf0,
 334                                           &subint_sw_if_index0,
 335                                           &error0, &is_l20);
 336
 337           matched1 = eth_identify_subint (hi1,
 338                                           b1,
 339                                           match_flags1,
 340                                           main_intf1,
 341                                           vlan_intf1,
 342                                           qinq_intf1,
 343                                           &subint_sw_if_index1,
 344                                           &error1, &is_l21);
 345
 346           if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
 347             {
 348               /* Drop packet */
 349               next0 = L2_EFP_FILTER_NEXT_DROP;
 350               b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 351             }
 352
 353           if (PREDICT_FALSE (sw_if_index1 != subint_sw_if_index1))
 354             {
 355               /* Drop packet */
 356               next1 = L2_EFP_FILTER_NEXT_DROP;
 357               b1->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 358             }
 359
 360           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
 361             {
 362               if (b0->flags & VLIB_BUFFER_IS_TRACED)
 363                 {
 364                   ethernet_header_t *h0 = vlib_buffer_get_current (b0);
 365                   l2_efp_filter_trace_t *t =
 366                     vlib_add_trace (vm, node, b0, sizeof (*t));
 367                   t->sw_if_index = sw_if_index0;
 368                   clib_memcpy (t->src, h0->src_address, 6);
 369                   clib_memcpy (t->dst, h0->dst_address, 6);
 370                   clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
 371                 }
 372               if (b1->flags & VLIB_BUFFER_IS_TRACED)
 373                 {
 374                   ethernet_header_t *h1 = vlib_buffer_get_current (b1);
 375                   l2_efp_filter_trace_t *t =
 376                     vlib_add_trace (vm, node, b1, sizeof (*t));
 377                   t->sw_if_index = sw_if_index1;
 378                   clib_memcpy (t->src, h1->src_address, 6);
 379                   clib_memcpy (t->dst, h1->dst_address, 6);
 380                   clib_memcpy (t->raw, &h1->type, sizeof (t->raw));
 381                 }
 382             }
 383
 384           /* verify speculative enqueues, maybe switch current next frame */
 385           /* if next0==next1==next_index then nothing special needs to be done */
 386           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
 387                                            to_next, n_left_to_next,
 388                                            bi0, bi1, next0, next1);
 389         }
 390
 391       while (n_left_from > 0 && n_left_to_next > 0)
 392         {
 393           u32 bi0;
 394           vlib_buffer_t *b0;
 395           u32 next0;
 396           u32 sw_if_index0;
 397           u32 feature_bitmap0;
 398           u16 first_ethertype0;
 399           u16 outer_id0, inner_id0;
 400           u32 match_flags0;
 401           u32 port_sw_if_index0, subint_sw_if_index0;
 402           vnet_hw_interface_t *hi0;
 403           main_intf_t *main_intf0;
 404           vlan_intf_t *vlan_intf0;
 405           qinq_intf_t *qinq_intf0;
 406           u32 is_l20;
 407           __attribute__ ((unused)) u32 matched0;
 408           u8 error0;
 409
 410           /* speculatively enqueue b0 to the current next frame */
 411           bi0 = from[0];
 412           to_next[0] = bi0;
 413           from += 1;
 414           to_next += 1;
 415           n_left_from -= 1;
 416           n_left_to_next -= 1;
 417
 418           b0 = vlib_get_buffer (vm, bi0);
 419           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 420
 421           /* process 1 packet */
 422           em->counters[node_counter_base_index +
 423                        L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 1;
 424
 425           /* Remove ourself from the feature bitmap */
 426           feature_bitmap0 =
 427             vnet_buffer (b0)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 428
 429           /* Determine next node */
 430           l2_output_dispatch (msm->vlib_main,
 431                               msm->vnet_main,
 432                               node,
 433                               l2_efp_filter_node.index,
 434                               &cached_sw_if_index,
 435                               &cached_next_index,
 436                               &msm->next_nodes,
 437                               b0, sw_if_index0, feature_bitmap0, &next0);
 438
 439           /* perform the efp filter check on one packet */
 440
 441           extract_keys (msm->vnet_main,
 442                         sw_if_index0,
 443                         b0,
 444                         &port_sw_if_index0,
 445                         &first_ethertype0,
 446                         &outer_id0, &inner_id0, &match_flags0);
 447
 448           eth_vlan_table_lookups (&ethernet_main,
 449                                   msm->vnet_main,
 450                                   port_sw_if_index0,
 451                                   first_ethertype0,
 452                                   outer_id0,
 453                                   inner_id0,
 454                                   &hi0,
 455                                   &main_intf0, &vlan_intf0, &qinq_intf0);
 456
 457           matched0 = eth_identify_subint (hi0,
 458                                           b0,
 459                                           match_flags0,
 460                                           main_intf0,
 461                                           vlan_intf0,
 462                                           qinq_intf0,
 463                                           &subint_sw_if_index0,
 464                                           &error0, &is_l20);
 465
 466           if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
 467             {
 468               /* Drop packet */
 469               next0 = L2_EFP_FILTER_NEXT_DROP;
 470               b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 471             }
 472
 473           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 474                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 475             {
 476               ethernet_header_t *h0 = vlib_buffer_get_current (b0);
 477               l2_efp_filter_trace_t *t =
 478                 vlib_add_trace (vm, node, b0, sizeof (*t));
 479               t->sw_if_index = sw_if_index0;
 480               clib_memcpy (t->src, h0->src_address, 6);
 481               clib_memcpy (t->dst, h0->dst_address, 6);
 482               clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
 483             }
 484
 485           /* verify speculative enqueue, maybe switch current next frame */
 486           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 487                                            to_next, n_left_to_next,
 488                                            bi0, next0);
 489         }
 490
 491       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 492     }
 493
 494   return frame->n_vectors;
 495 }
 496
 497
 498 /* *INDENT-OFF* */
 499 VLIB_REGISTER_NODE (l2_efp_filter_node,static) = {
 500   .function = l2_efp_filter_node_fn,
 501   .name = "l2-efp-filter",
 502   .vector_size = sizeof (u32),
 503   .format_trace = format_l2_efp_filter_trace,
 504   .type = VLIB_NODE_TYPE_INTERNAL,
 505
 506   .n_errors = ARRAY_LEN(l2_efp_filter_error_strings),
 507   .error_strings = l2_efp_filter_error_strings,
 508
 509   .n_next_nodes = L2_EFP_FILTER_N_NEXT,
 510
 511   /* edit / add dispositions here */
 512   .next_nodes = {
 513        [L2_EFP_FILTER_NEXT_DROP]  = "error-drop",
 514   },
 515 };
 516 /* *INDENT-ON* */
 517
 518 VLIB_NODE_FUNCTION_MULTIARCH (l2_efp_filter_node, l2_efp_filter_node_fn)
 519      clib_error_t *l2_efp_filter_init (vlib_main_t * vm)
 520 {
 521   l2_efp_filter_main_t *mp = &l2_efp_filter_main;
 522
 523   mp->vlib_main = vm;
 524   mp->vnet_main = vnet_get_main ();
 525
 526   /* Initialize the feature next-node indexes */
 527   feat_bitmap_init_next_nodes (vm,
 528                                l2_efp_filter_node.index,
 529                                L2OUTPUT_N_FEAT,
 530                                l2output_get_feat_names (),
 531                                mp->next_nodes.feat_next_node_index);
 532
 533   /* Initialize the output node mapping table */
 534   l2output_init_output_node_vec (&mp->next_nodes.output_node_index_vec);
 535
 536   return 0;
 537 }
 538
 539 VLIB_INIT_FUNCTION (l2_efp_filter_init);
 540
 541
 542 /** Enable/disable the EFP Filter check on the subinterface. */
 543 void
 544 l2_efp_filter_configure (vnet_main_t * vnet_main, u32 sw_if_index, u32 enable)
 545 {
 546   /* set the interface flag */
 547   l2output_intf_bitmap_enable (sw_if_index, L2OUTPUT_FEAT_EFP_FILTER, enable);
 548 }
 549
 550
 551 /**
 552  * Set subinterface egress efp filter enable/disable.
 553  * The CLI format is:
 554  *    set interface l2 efp-filter <interface> [disable]]
 555  */
 556 static clib_error_t *
 557 int_l2_efp_filter (vlib_main_t * vm,
 558                    unformat_input_t * input, vlib_cli_command_t * cmd)
 559 {
 560   vnet_main_t *vnm = vnet_get_main ();
 561   clib_error_t *error = 0;
 562   u32 sw_if_index;
 563   u32 enable;
 564
 565   if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
 566     {
 567       error = clib_error_return (0, "unknown interface `%U'",
 568                                  format_unformat_error, input);
 569       goto done;
 570     }
 571
 572   enable = 1;
 573   if (unformat (input, "disable"))
 574     {
 575       enable = 0;
 576     }
 577
 578   /* enable/disable the feature */
 579   l2_efp_filter_configure (vnm, sw_if_index, enable);
 580
 581 done:
 582   return error;
 583 }
 584
 585
 586 /*?
 587  * EFP filtering is a basic switch feature which prevents an interface from
 588  * transmitting a packet that doesn't match the interface's ingress match
 589  * criteria. The check has two parts, one performed before egress vlan tag
 590  * rewrite and one after. This command enables or disables the EFP filtering
 591  * for a given sub-interface.
 592  *
 593  * @cliexpar
 594  * Example of how to enable a Layer 2 efp-filter on a sub-interface:
 595  * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200}
 596  * Example of how to disable a Layer 2 efp-filter on a sub-interface:
 597  * @cliexcmd{set interface l2 efp-filter GigabitEthernet0/8/0.200 disable}
 598 ?*/
 599 /* *INDENT-OFF* */
 600 VLIB_CLI_COMMAND (int_l2_efp_filter_cli, static) = {
 601   .path = "set interface l2 efp-filter",
 602   .short_help = "set interface l2 efp-filter <interface> [disable]",
 603   .function = int_l2_efp_filter,
 604 };
 605 /* *INDENT-ON* */
 606
 607
 608 /*
 609  * fd.io coding-style-patch-verification: ON
 610  *
 611  * Local Variables:
 612  * eval: (c-set-style "gnu")
 613  * End:
 614  */