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 typedef struct
  30 {
  31
  32   /* Next nodes for features and output interfaces */
  33   l2_output_next_nodes_st next_nodes;
  34
  35   /* convenience variables */
  36   vlib_main_t *vlib_main;
  37   vnet_main_t *vnet_main;
  38 } l2_efp_filter_main_t;
  39
  40
  41 typedef struct
  42 {
  43   /* per-pkt trace data */
  44   u8 src[6];
  45   u8 dst[6];
  46   u8 raw[12];                   /* raw data (vlans) */
  47   u32 sw_if_index;
  48 } l2_efp_filter_trace_t;
  49
  50 /* packet trace format function */
  51 static u8 *
  52 format_l2_efp_filter_trace (u8 * s, va_list * args)
  53 {
  54   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  55   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  56   l2_efp_filter_trace_t *t = va_arg (*args, l2_efp_filter_trace_t *);
  57
  58   s = format (s, "l2-output-vtr: sw_if_index %d dst %U src %U data "
  59               "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
  60               t->sw_if_index,
  61               format_ethernet_address, t->dst,
  62               format_ethernet_address, t->src,
  63               t->raw[0], t->raw[1], t->raw[2], t->raw[3], t->raw[4],
  64               t->raw[5], t->raw[6], t->raw[7], t->raw[8], t->raw[9],
  65               t->raw[10], t->raw[11]);
  66   return s;
  67 }
  68
  69 l2_efp_filter_main_t l2_efp_filter_main;
  70
  71 static vlib_node_registration_t l2_efp_filter_node;
  72
  73 #define foreach_l2_efp_filter_error                     \
  74 _(L2_EFP_FILTER, "L2 EFP filter packets")               \
  75 _(DROP,          "L2 EFP filter post-rewrite drops")
  76
  77 typedef enum
  78 {
  79 #define _(sym,str) L2_EFP_FILTER_ERROR_##sym,
  80   foreach_l2_efp_filter_error
  81 #undef _
  82     L2_EFP_FILTER_N_ERROR,
  83 } l2_efp_filter_error_t;
  84
  85 static char *l2_efp_filter_error_strings[] = {
  86 #define _(sym,string) string,
  87   foreach_l2_efp_filter_error
  88 #undef _
  89 };
  90
  91 typedef enum
  92 {
  93   L2_EFP_FILTER_NEXT_DROP,
  94   L2_EFP_FILTER_N_NEXT,
  95 } l2_efp_filter_next_t;
  96
  97
  98 /**
  99  *  Extract fields from the packet that will be used in interface
 100  *  classification.
 101  */
 102 static_always_inline void
 103 extract_keys (vnet_main_t * vnet_main,
 104               u32 sw_if_index0,
 105               vlib_buffer_t * b0,
 106               u32 * port_sw_if_index0,
 107               u16 * first_ethertype0,
 108               u16 * outer_id0, u16 * inner_id0, u32 * match_flags0)
 109 {
 110   ethernet_header_t *e0;
 111   ethernet_vlan_header_t *h0;
 112   u32 tag_len;
 113   u32 tag_num;
 114
 115   *port_sw_if_index0 =
 116     vnet_get_sup_sw_interface (vnet_main, sw_if_index0)->sw_if_index;
 117
 118   e0 = vlib_buffer_get_current (b0);
 119   h0 = (ethernet_vlan_header_t *) (e0 + 1);
 120
 121   *first_ethertype0 = clib_net_to_host_u16 (e0->type);
 122   *outer_id0 = clib_net_to_host_u16 (h0[0].priority_cfi_and_id);
 123   *inner_id0 = clib_net_to_host_u16 (h0[1].priority_cfi_and_id);
 124
 125   tag_len = vnet_buffer (b0)->l2.l2_len - sizeof (ethernet_header_t);
 126   tag_num = tag_len / sizeof (ethernet_vlan_header_t);
 127   *match_flags0 = eth_create_valid_subint_match_flags (tag_num);
 128 }
 129
 130 /*
 131  * EFP filtering is a basic switch feature which prevents an interface from
 132  * transmitting a packet that doesn't match the interface's ingress match
 133  * criteria. The check has two parts, one performed before egress vlan tag
 134  * rewrite and one after.
 135  *
 136  * The pre-rewrite check insures the packet matches what an ingress packet looks
 137  * like after going through the interface's ingress tag rewrite operation. Only
 138  * pushed tags are compared. So:
 139  * - if the ingress vlan tag rewrite pushes no tags (or is not enabled),
 140  *   any packet passes the filter
 141  * - if the ingress vlan tag rewrite pushes one tag,
 142  *   the packet must have at least one tag, and the outer tag must match the pushed tag
 143  * - if the ingress vlan tag rewrite pushes two tags,
 144  *   the packet must have at least two tags, and the outer two tags must match the pushed tags
 145  *
 146  * The pre-rewrite check is performed in the l2-output node.
 147  *
 148  * The post-rewrite check insures the packet matches what an ingress packet looks
 149  * like before going through the interface's ingress tag rewrite operation. It verifies
 150  * that such a packet arriving on the wire at this port would be classified as arriving
 151  * an input interface equal to the packet's output interface. This can be done by running
 152  * the output packet's vlan tags and output port through the interface classification,
 153  * and checking if the resulting interface matches the output interface.
 154  *
 155  * The post-rewrite check is performed here.
 156  */
 157
 158 static uword
 159 l2_efp_filter_node_fn (vlib_main_t * vm,
 160                        vlib_node_runtime_t * node, vlib_frame_t * frame)
 161 {
 162   u32 n_left_from, *from, *to_next;
 163   l2_efp_filter_next_t next_index;
 164   l2_efp_filter_main_t *msm = &l2_efp_filter_main;
 165   vlib_node_t *n = vlib_get_node (vm, l2_efp_filter_node.index);
 166   u32 node_counter_base_index = n->error_heap_index;
 167   vlib_error_main_t *em = &vm->error_main;
 168   u32 cached_sw_if_index = ~0;
 169   u32 cached_next_index = ~0;
 170
 171   /* invalidate cache to begin with */
 172   cached_sw_if_index = ~0;
 173
 174   from = vlib_frame_vector_args (frame);
 175   n_left_from = frame->n_vectors;       /* number of packets to process */
 176   next_index = node->cached_next_index;
 177
 178   while (n_left_from > 0)
 179     {
 180       u32 n_left_to_next;
 181
 182       /* get space to enqueue frame to graph node "next_index" */
 183       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 184
 185       while (n_left_from >= 6 && n_left_to_next >= 2)
 186         {
 187           u32 bi0, bi1;
 188           vlib_buffer_t *b0, *b1;
 189           u32 next0, next1;
 190           u32 sw_if_index0, sw_if_index1;
 191           u32 feature_bitmap0, feature_bitmap1;
 192           u16 first_ethertype0, first_ethertype1;
 193           u16 outer_id0, inner_id0, outer_id1, inner_id1;
 194           u32 match_flags0, match_flags1;
 195           u32 port_sw_if_index0, subint_sw_if_index0, port_sw_if_index1,
 196             subint_sw_if_index1;
 197           vnet_hw_interface_t *hi0, *hi1;
 198           main_intf_t *main_intf0, *main_intf1;
 199           vlan_intf_t *vlan_intf0, *vlan_intf1;
 200           qinq_intf_t *qinq_intf0, *qinq_intf1;
 201           u32 is_l20, is_l21;
 202           __attribute__ ((unused)) u32 matched0, matched1;
 203           u8 error0, error1;
 204
 205           /* Prefetch next iteration. */
 206           {
 207             vlib_buffer_t *p2, *p3, *p4, *p5;
 208             __attribute__ ((unused)) u32 sw_if_index2, sw_if_index3;
 209
 210             p2 = vlib_get_buffer (vm, from[2]);
 211             p3 = vlib_get_buffer (vm, from[3]);
 212             p4 = vlib_get_buffer (vm, from[4]);
 213             p5 = vlib_get_buffer (vm, from[5]);
 214
 215             /* Prefetch the buffer header and packet for the N+2 loop iteration */
 216             vlib_prefetch_buffer_header (p4, LOAD);
 217             vlib_prefetch_buffer_header (p5, LOAD);
 218
 219             CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
 220             CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
 221
 222             /*
 223              * Prefetch the input config for the N+1 loop iteration
 224              * This depends on the buffer header above
 225              */
 226             sw_if_index2 = vnet_buffer (p2)->sw_if_index[VLIB_TX];
 227             sw_if_index3 = vnet_buffer (p3)->sw_if_index[VLIB_TX];
 228             /*
 229              * $$$ TODO
 230              * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index2), CLIB_CACHE_LINE_BYTES, LOAD);
 231              * CLIB_PREFETCH (vec_elt_at_index(l2output_main.configs, sw_if_index3), CLIB_CACHE_LINE_BYTES, LOAD);
 232              */
 233           }
 234
 235           /* speculatively enqueue b0 and b1 to the current next frame */
 236           /* bi is "buffer index", b is pointer to the buffer */
 237           to_next[0] = bi0 = from[0];
 238           to_next[1] = bi1 = from[1];
 239           from += 2;
 240           to_next += 2;
 241           n_left_from -= 2;
 242           n_left_to_next -= 2;
 243
 244           b0 = vlib_get_buffer (vm, bi0);
 245           b1 = vlib_get_buffer (vm, bi1);
 246
 247           /* TX interface handles */
 248           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 249           sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX];
 250
 251           /* process 2 packets */
 252           em->counters[node_counter_base_index +
 253                        L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 2;
 254
 255           /* Remove ourself from the feature bitmap */
 256           feature_bitmap0 =
 257             vnet_buffer (b0)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 258           feature_bitmap1 =
 259             vnet_buffer (b1)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 260
 261           /* Determine next node */
 262           l2_output_dispatch (msm->vlib_main,
 263                               msm->vnet_main,
 264                               node,
 265                               l2_efp_filter_node.index,
 266                               &cached_sw_if_index,
 267                               &cached_next_index,
 268                               &msm->next_nodes,
 269                               b0, sw_if_index0, feature_bitmap0, &next0);
 270           l2_output_dispatch (msm->vlib_main,
 271                               msm->vnet_main,
 272                               node,
 273                               l2_efp_filter_node.index,
 274                               &cached_sw_if_index,
 275                               &cached_next_index,
 276                               &msm->next_nodes,
 277                               b1, sw_if_index1, feature_bitmap1, &next1);
 278
 279           /* perform the efp filter check on two packets */
 280
 281           extract_keys (msm->vnet_main,
 282                         sw_if_index0,
 283                         b0,
 284                         &port_sw_if_index0,
 285                         &first_ethertype0,
 286                         &outer_id0, &inner_id0, &match_flags0);
 287
 288           extract_keys (msm->vnet_main,
 289                         sw_if_index1,
 290                         b1,
 291                         &port_sw_if_index1,
 292                         &first_ethertype1,
 293                         &outer_id1, &inner_id1, &match_flags1);
 294
 295           eth_vlan_table_lookups (&ethernet_main,
 296                                   msm->vnet_main,
 297                                   port_sw_if_index0,
 298                                   first_ethertype0,
 299                                   outer_id0,
 300                                   inner_id0,
 301                                   &hi0,
 302                                   &main_intf0, &vlan_intf0, &qinq_intf0);
 303
 304           eth_vlan_table_lookups (&ethernet_main,
 305                                   msm->vnet_main,
 306                                   port_sw_if_index1,
 307                                   first_ethertype1,
 308                                   outer_id1,
 309                                   inner_id1,
 310                                   &hi1,
 311                                   &main_intf1, &vlan_intf1, &qinq_intf1);
 312
 313           matched0 = eth_identify_subint (hi0,
 314                                           b0,
 315                                           match_flags0,
 316                                           main_intf0,
 317                                           vlan_intf0,
 318                                           qinq_intf0,
 319                                           &subint_sw_if_index0,
 320                                           &error0, &is_l20);
 321
 322           matched1 = eth_identify_subint (hi1,
 323                                           b1,
 324                                           match_flags1,
 325                                           main_intf1,
 326                                           vlan_intf1,
 327                                           qinq_intf1,
 328                                           &subint_sw_if_index1,
 329                                           &error1, &is_l21);
 330
 331           if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
 332             {
 333               /* Drop packet */
 334               next0 = L2_EFP_FILTER_NEXT_DROP;
 335               b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 336             }
 337
 338           if (PREDICT_FALSE (sw_if_index1 != subint_sw_if_index1))
 339             {
 340               /* Drop packet */
 341               next1 = L2_EFP_FILTER_NEXT_DROP;
 342               b1->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 343             }
 344
 345           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
 346             {
 347               if (b0->flags & VLIB_BUFFER_IS_TRACED)
 348                 {
 349                   ethernet_header_t *h0 = vlib_buffer_get_current (b0);
 350                   l2_efp_filter_trace_t *t =
 351                     vlib_add_trace (vm, node, b0, sizeof (*t));
 352                   t->sw_if_index = sw_if_index0;
 353                   clib_memcpy (t->src, h0->src_address, 6);
 354                   clib_memcpy (t->dst, h0->dst_address, 6);
 355                   clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
 356                 }
 357               if (b1->flags & VLIB_BUFFER_IS_TRACED)
 358                 {
 359                   ethernet_header_t *h1 = vlib_buffer_get_current (b1);
 360                   l2_efp_filter_trace_t *t =
 361                     vlib_add_trace (vm, node, b1, sizeof (*t));
 362                   t->sw_if_index = sw_if_index1;
 363                   clib_memcpy (t->src, h1->src_address, 6);
 364                   clib_memcpy (t->dst, h1->dst_address, 6);
 365                   clib_memcpy (t->raw, &h1->type, sizeof (t->raw));
 366                 }
 367             }
 368
 369           /* verify speculative enqueues, maybe switch current next frame */
 370           /* if next0==next1==next_index then nothing special needs to be done */
 371           vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
 372                                            to_next, n_left_to_next,
 373                                            bi0, bi1, next0, next1);
 374         }
 375
 376       while (n_left_from > 0 && n_left_to_next > 0)
 377         {
 378           u32 bi0;
 379           vlib_buffer_t *b0;
 380           u32 next0;
 381           u32 sw_if_index0;
 382           u32 feature_bitmap0;
 383           u16 first_ethertype0;
 384           u16 outer_id0, inner_id0;
 385           u32 match_flags0;
 386           u32 port_sw_if_index0, subint_sw_if_index0;
 387           vnet_hw_interface_t *hi0;
 388           main_intf_t *main_intf0;
 389           vlan_intf_t *vlan_intf0;
 390           qinq_intf_t *qinq_intf0;
 391           u32 is_l20;
 392           __attribute__ ((unused)) u32 matched0;
 393           u8 error0;
 394
 395           /* speculatively enqueue b0 to the current next frame */
 396           bi0 = from[0];
 397           to_next[0] = bi0;
 398           from += 1;
 399           to_next += 1;
 400           n_left_from -= 1;
 401           n_left_to_next -= 1;
 402
 403           b0 = vlib_get_buffer (vm, bi0);
 404           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 405
 406           /* process 1 packet */
 407           em->counters[node_counter_base_index +
 408                        L2_EFP_FILTER_ERROR_L2_EFP_FILTER] += 1;
 409
 410           /* Remove ourself from the feature bitmap */
 411           feature_bitmap0 =
 412             vnet_buffer (b0)->l2.feature_bitmap & ~L2OUTPUT_FEAT_EFP_FILTER;
 413
 414           /* Determine next node */
 415           l2_output_dispatch (msm->vlib_main,
 416                               msm->vnet_main,
 417                               node,
 418                               l2_efp_filter_node.index,
 419                               &cached_sw_if_index,
 420                               &cached_next_index,
 421                               &msm->next_nodes,
 422                               b0, sw_if_index0, feature_bitmap0, &next0);
 423
 424           /* perform the efp filter check on one packet */
 425
 426           extract_keys (msm->vnet_main,
 427                         sw_if_index0,
 428                         b0,
 429                         &port_sw_if_index0,
 430                         &first_ethertype0,
 431                         &outer_id0, &inner_id0, &match_flags0);
 432
 433           eth_vlan_table_lookups (&ethernet_main,
 434                                   msm->vnet_main,
 435                                   port_sw_if_index0,
 436                                   first_ethertype0,
 437                                   outer_id0,
 438                                   inner_id0,
 439                                   &hi0,
 440                                   &main_intf0, &vlan_intf0, &qinq_intf0);
 441
 442           matched0 = eth_identify_subint (hi0,
 443                                           b0,
 444                                           match_flags0,
 445                                           main_intf0,
 446                                           vlan_intf0,
 447                                           qinq_intf0,
 448                                           &subint_sw_if_index0,
 449                                           &error0, &is_l20);
 450
 451           if (PREDICT_FALSE (sw_if_index0 != subint_sw_if_index0))
 452             {
 453               /* Drop packet */
 454               next0 = L2_EFP_FILTER_NEXT_DROP;
 455               b0->error = node->errors[L2_EFP_FILTER_ERROR_DROP];
 456             }
 457
 458           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 459                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 460             {
 461               ethernet_header_t *h0 = vlib_buffer_get_current (b0);
 462               l2_efp_filter_trace_t *t =
 463                 vlib_add_trace (vm, node, b0, sizeof (*t));
 464               t->sw_if_index = sw_if_index0;
 465               clib_memcpy (t->src, h0->src_address, 6);
 466               clib_memcpy (t->dst, h0->dst_address, 6);
 467               clib_memcpy (t->raw, &h0->type, sizeof (t->raw));
 468             }
 469
 470           /* verify speculative enqueue, maybe switch current next frame */
 471           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 472                                            to_next, n_left_to_next,
 473                                            bi0, next0);
 474         }
 475
 476       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 477     }
 478
 479   return frame->n_vectors;
 480 }
 481
 482
 483 /* *INDENT-OFF* */
 484 VLIB_REGISTER_NODE (l2_efp_filter_node,static) = {
 485   .function = l2_efp_filter_node_fn,
 486   .name = "l2-efp-filter",
 487   .vector_size = sizeof (u32),
 488   .format_trace = format_l2_efp_filter_trace,
 489   .type = VLIB_NODE_TYPE_INTERNAL,
 490
 491   .n_errors = ARRAY_LEN(l2_efp_filter_error_strings),
 492   .error_strings = l2_efp_filter_error_strings,
 493
 494   .n_next_nodes = L2_EFP_FILTER_N_NEXT,
 495
 496   /* edit / add dispositions here */
 497   .next_nodes = {
 498        [L2_EFP_FILTER_NEXT_DROP]  = "error-drop",
 499   },
 500 };
 501 /* *INDENT-ON* */
 502
 503 VLIB_NODE_FUNCTION_MULTIARCH (l2_efp_filter_node, l2_efp_filter_node_fn)
 504      clib_error_t *l2_efp_filter_init (vlib_main_t * vm)
 505 {
 506   l2_efp_filter_main_t *mp = &l2_efp_filter_main;
 507
 508   mp->vlib_main = vm;
 509   mp->vnet_main = vnet_get_main ();
 510
 511   /* Initialize the feature next-node indexes */
 512   feat_bitmap_init_next_nodes (vm,
 513                                l2_efp_filter_node.index,
 514                                L2OUTPUT_N_FEAT,
 515                                l2output_get_feat_names (),
 516                                mp->next_nodes.feat_next_node_index);
 517
 518   /* Initialize the output node mapping table */
 519   l2output_init_output_node_vec (&mp->next_nodes.output_node_index_vec);
 520
 521   return 0;
 522 }
 523
 524 VLIB_INIT_FUNCTION (l2_efp_filter_init);
 525
 526
 527 /** Enable/disable the EFP Filter check on the subinterface. */
 528 void
 529 l2_efp_filter_configure (vnet_main_t * vnet_main, u32 sw_if_index, u32 enable)
 530 {
 531   /* set the interface flag */
 532   l2output_intf_bitmap_enable (sw_if_index, L2OUTPUT_FEAT_EFP_FILTER, enable);
 533 }
 534
 535
 536 /**
 537  * Set subinterface egress efp filter enable/disable.
 538  * The CLI format is:
 539  *    set interface l2 efp-filter <interface> [disable]]
 540  */
 541 static clib_error_t *
 542 int_l2_efp_filter (vlib_main_t * vm,
 543                    unformat_input_t * input, vlib_cli_command_t * cmd)
 544 {
 545   vnet_main_t *vnm = vnet_get_main ();
 546   clib_error_t *error = 0;
 547   u32 sw_if_index;
 548   u32 enable;
 549
 550   if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
 551     {
 552       error = clib_error_return (0, "unknown interface `%U'",
 553                                  format_unformat_error, input);
 554       goto done;
 555     }
 556
 557   enable = 1;
 558   if (unformat (input, "disable"))
 559     {
 560       enable = 0;
 561     }
 562
 563   /* enable/disable the feature */
 564   l2_efp_filter_configure (vnm, sw_if_index, enable);
 565
 566 done:
 567   return error;
 568 }
 569
 570
 571 /* *INDENT-OFF* */
 572 VLIB_CLI_COMMAND (int_l2_efp_filter_cli, static) = {
 573   .path = "set interface l2 efp-filter",
 574   .short_help = "set interface l2 efp-filter <interface> [disable]",
 575   .function = int_l2_efp_filter,
 576 };
 577 /* *INDENT-ON* */
 578
 579
 580 /*
 581  * fd.io coding-style-patch-verification: ON
 582  *
 583  * Local Variables:
 584  * eval: (c-set-style "gnu")
 585  * End:
 586  */