src/plugins/srv6-as/node.c

   1 /*
   2  * Copyright (c) 2015 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 #include <vlib/vlib.h>
  16 #include <vnet/vnet.h>
  17 #include <vppinfra/error.h>
  18 #include <srv6-as/as.h>
  19
  20
  21 /******************************* Packet tracing *******************************/
  22
  23 typedef struct
  24 {
  25   u32 localsid_index;
  26 } srv6_as_localsid_trace_t;
  27
  28 typedef struct
  29 {
  30   u8 error;
  31   ip6_address_t src, dst;
  32 } srv6_as_rewrite_trace_t;
  33
  34 static u8 *
  35 format_srv6_as_localsid_trace (u8 * s, va_list * args)
  36 {
  37   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  38   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  39   srv6_as_localsid_trace_t *t = va_arg (*args, srv6_as_localsid_trace_t *);
  40
  41   return format (s, "SRv6-AS-localsid: localsid_index %d", t->localsid_index);
  42 }
  43
  44 static u8 *
  45 format_srv6_as_rewrite_trace (u8 * s, va_list * args)
  46 {
  47   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  48   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  49   srv6_as_rewrite_trace_t *t = va_arg (*args, srv6_as_rewrite_trace_t *);
  50
  51   if (PREDICT_FALSE (t->error != 0))
  52     {
  53       return format (s, "SRv6-AS-rewrite: cache is empty");
  54     }
  55
  56   return format (s, "SRv6-AS-rewrite: src %U dst %U",
  57                  format_ip6_address, &t->src, format_ip6_address, &t->dst);
  58 }
  59
  60
  61 /***************************** Nodes registration *****************************/
  62
  63 vlib_node_registration_t srv6_as4_rewrite_node;
  64 vlib_node_registration_t srv6_as6_rewrite_node;
  65
  66
  67 /****************************** Packet counters *******************************/
  68
  69 #define foreach_srv6_as_rewrite_counter \
  70 _(PROCESSED, "srv6-as rewritten packets") \
  71 _(NO_RW, "(Error) No header for rewriting.")
  72
  73 typedef enum
  74 {
  75 #define _(sym,str) SRV6_AS_REWRITE_COUNTER_##sym,
  76   foreach_srv6_as_rewrite_counter
  77 #undef _
  78     SRV6_AS_REWRITE_N_COUNTERS,
  79 } srv6_as_rewrite_counters;
  80
  81 static char *srv6_as_rewrite_counter_strings[] = {
  82 #define _(sym,string) string,
  83   foreach_srv6_as_rewrite_counter
  84 #undef _
  85 };
  86
  87
  88 /********************************* Next nodes *********************************/
  89
  90 typedef enum
  91 {
  92   SRV6_AS_LOCALSID_NEXT_ERROR,
  93   SRV6_AS_LOCALSID_NEXT_REWRITE4,
  94   SRV6_AS_LOCALSID_NEXT_REWRITE6,
  95   SRV6_AS_LOCALSID_NEXT_INTERFACE,
  96   SRV6_AS_LOCALSID_N_NEXT,
  97 } srv6_as_localsid_next_t;
  98
  99 typedef enum
 100 {
 101   SRV6_AS_REWRITE_NEXT_ERROR,
 102   SRV6_AS_REWRITE_NEXT_LOOKUP,
 103   SRV6_AS_REWRITE_N_NEXT,
 104 } srv6_as_rewrite_next_t;
 105
 106
 107 /******************************* Local SID node *******************************/
 108
 109 /**
 110  * @brief Function doing SRH processing for AS behavior
 111  */
 112 static_always_inline void
 113 end_as_processing (vlib_buffer_t * b0,
 114                    ip6_header_t * ip0,
 115                    srv6_as_localsid_t * ls0_mem, u32 * next0)
 116 {
 117   u16 encap_len;
 118   ip6_ext_header_t *ext_hdr;
 119   u8 hdr_type;
 120
 121   /* Compute encapsulation headers length */
 122   encap_len = sizeof (ip6_header_t);
 123   ext_hdr = (ip6_ext_header_t *) (ip0 + 1);
 124   hdr_type = ip0->protocol;
 125
 126   while (ip6_ext_hdr (hdr_type))
 127     {
 128       encap_len += ip6_ext_header_len (ext_hdr);
 129       hdr_type = ext_hdr->next_hdr;
 130       ext_hdr = ip6_ext_next_header (ext_hdr);
 131     }
 132
 133   /* Make sure next header is valid */
 134   if (PREDICT_FALSE (hdr_type != IP_PROTOCOL_IPV6 &&
 135                      hdr_type != IP_PROTOCOL_IP_IN_IP &&
 136                      hdr_type != IP_PROTOCOL_IP6_NONXT))
 137     {
 138       return;
 139     }
 140
 141   /* Remove IP header and extensions */
 142   vlib_buffer_advance (b0, encap_len);
 143
 144   if (hdr_type == IP_PROTOCOL_IP6_NONXT)
 145     {
 146       /* Set output interface */
 147       vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0_mem->sw_if_index_out;
 148
 149       /* Set next node to interface-output */
 150       *next0 = SRV6_AS_LOCALSID_NEXT_INTERFACE;
 151     }
 152   else
 153     {
 154       /* Set Xconnect adjacency to VNF */
 155       vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0_mem->nh_adj;
 156
 157       /* Set next node to ip-rewrite */
 158       *next0 = (hdr_type == IP_PROTOCOL_IPV6) ?
 159         SRV6_AS_LOCALSID_NEXT_REWRITE6 : SRV6_AS_LOCALSID_NEXT_REWRITE4;
 160     }
 161 }
 162
 163 /**
 164  * @brief SRv6 AS Localsid graph node
 165  */
 166 static uword
 167 srv6_as_localsid_fn (vlib_main_t * vm,
 168                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 169 {
 170   ip6_sr_main_t *sm = &sr_main;
 171   u32 n_left_from, next_index, *from, *to_next;
 172   u32 cnt_packets = 0;
 173
 174   from = vlib_frame_vector_args (frame);
 175   n_left_from = frame->n_vectors;
 176   next_index = node->cached_next_index;
 177
 178   while (n_left_from > 0)
 179     {
 180       u32 n_left_to_next;
 181
 182       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 183
 184       /* TODO: Dual/quad loop */
 185
 186       while (n_left_from > 0 && n_left_to_next > 0)
 187         {
 188           u32 bi0;
 189           vlib_buffer_t *b0;
 190           ip6_header_t *ip0 = 0;
 191           ip6_sr_localsid_t *ls0;
 192           u32 next0 = SRV6_AS_LOCALSID_NEXT_ERROR;
 193
 194           bi0 = from[0];
 195           to_next[0] = bi0;
 196           from += 1;
 197           to_next += 1;
 198           n_left_from -= 1;
 199           n_left_to_next -= 1;
 200
 201           b0 = vlib_get_buffer (vm, bi0);
 202           ip0 = vlib_buffer_get_current (b0);
 203
 204           /* Lookup the SR End behavior based on IP DA (adj) */
 205           ls0 = pool_elt_at_index (sm->localsids,
 206                                    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 207
 208           /* SRH processing */
 209           end_as_processing (b0, ip0, ls0->plugin_mem, &next0);
 210
 211           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 212             {
 213               srv6_as_localsid_trace_t *tr =
 214                 vlib_add_trace (vm, node, b0, sizeof *tr);
 215               tr->localsid_index = ls0 - sm->localsids;
 216             }
 217
 218           /* This increments the SRv6 per LocalSID counters. */
 219           vlib_increment_combined_counter (((next0 ==
 220                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 221                                             &(sm->sr_ls_invalid_counters) :
 222                                             &(sm->sr_ls_valid_counters)),
 223                                            vm->thread_index,
 224                                            ls0 - sm->localsids, 1,
 225                                            vlib_buffer_length_in_chain (vm,
 226                                                                         b0));
 227
 228           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 229                                            n_left_to_next, bi0, next0);
 230
 231           cnt_packets++;
 232         }
 233
 234       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 235     }
 236
 237   return frame->n_vectors;
 238 }
 239
 240 /* *INDENT-OFF* */
 241 VLIB_REGISTER_NODE (srv6_as_localsid_node) = {
 242   .function = srv6_as_localsid_fn,
 243   .name = "srv6-as-localsid",
 244   .vector_size = sizeof (u32),
 245   .format_trace = format_srv6_as_localsid_trace,
 246   .type = VLIB_NODE_TYPE_INTERNAL,
 247   .n_next_nodes = SRV6_AS_LOCALSID_N_NEXT,
 248   .next_nodes = {
 249     [SRV6_AS_LOCALSID_NEXT_REWRITE4] = "ip4-rewrite",
 250     [SRV6_AS_LOCALSID_NEXT_REWRITE6] = "ip6-rewrite",
 251     [SRV6_AS_LOCALSID_NEXT_INTERFACE] = "interface-output",
 252     [SRV6_AS_LOCALSID_NEXT_ERROR] = "error-drop",
 253   },
 254 };
 255 /* *INDENT-ON* */
 256
 257
 258 /******************************* Rewriting node *******************************/
 259
 260 /**
 261  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 262  */
 263 static uword
 264 srv6_as2_rewrite_fn (vlib_main_t * vm,
 265                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 266 {
 267   ip6_sr_main_t *srm = &sr_main;
 268   srv6_as_main_t *sm = &srv6_as_main;
 269   u32 n_left_from, next_index, *from, *to_next;
 270   u32 cnt_packets = 0;
 271
 272   from = vlib_frame_vector_args (frame);
 273   n_left_from = frame->n_vectors;
 274   next_index = node->cached_next_index;
 275
 276   while (n_left_from > 0)
 277     {
 278       u32 n_left_to_next;
 279
 280       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 281
 282       /* TODO: Dual/quad loop */
 283
 284       while (n_left_from > 0 && n_left_to_next > 0)
 285         {
 286           u32 bi0;
 287           vlib_buffer_t *b0;
 288           ethernet_header_t *en0;
 289           ip6_header_t *ip0 = 0;
 290           ip6_sr_localsid_t *ls0;
 291           srv6_as_localsid_t *ls0_mem;
 292           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 293
 294           bi0 = from[0];
 295           to_next[0] = bi0;
 296           from += 1;
 297           to_next += 1;
 298           n_left_from -= 1;
 299           n_left_to_next -= 1;
 300
 301           b0 = vlib_get_buffer (vm, bi0);
 302           en0 = vlib_buffer_get_current (b0);
 303           ls0 = pool_elt_at_index (srm->localsids,
 304                                    sm->sw_iface_localsid2[vnet_buffer
 305                                                           (b0)->sw_if_index
 306                                                           [VLIB_RX]]);
 307           ls0_mem = ls0->plugin_mem;
 308
 309           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 310             {
 311               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 312               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 313             }
 314           else
 315             {
 316               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 317                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 318
 319               clib_memcpy (((u8 *) en0) - vec_len (ls0_mem->rewrite),
 320                            ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 321               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 322
 323               ip0 = vlib_buffer_get_current (b0);
 324
 325               ip0->payload_length =
 326                 clib_host_to_net_u16 (b0->current_length -
 327                                       sizeof (ip6_header_t));
 328             }
 329
 330           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 331               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 332             {
 333               srv6_as_rewrite_trace_t *tr =
 334                 vlib_add_trace (vm, node, b0, sizeof *tr);
 335               tr->error = 0;
 336
 337               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 338                 {
 339                   tr->error = 1;
 340                 }
 341               else
 342                 {
 343                   clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
 344                                sizeof tr->src.as_u8);
 345                   clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
 346                                sizeof tr->dst.as_u8);
 347                 }
 348             }
 349
 350           /* Increment per-SID AS rewrite counters */
 351           vlib_increment_combined_counter (((next0 ==
 352                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 353                                             &(sm->invalid_counters) :
 354                                             &(sm->valid_counters)),
 355                                            vm->thread_index, ls0_mem->index,
 356                                            1, vlib_buffer_length_in_chain (vm,
 357                                                                            b0));
 358
 359           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 360                                            n_left_to_next, bi0, next0);
 361
 362           cnt_packets++;
 363         }
 364
 365       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 366     }
 367
 368   /* Update counters */
 369   vlib_node_increment_counter (vm, srv6_as4_rewrite_node.index,
 370                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 371                                cnt_packets);
 372
 373   return frame->n_vectors;
 374 }
 375
 376 /* *INDENT-OFF* */
 377 VLIB_REGISTER_NODE (srv6_as2_rewrite_node) = {
 378   .function = srv6_as2_rewrite_fn,
 379   .name = "srv6-as2-rewrite",
 380   .vector_size = sizeof (u32),
 381   .format_trace = format_srv6_as_rewrite_trace,
 382   .type = VLIB_NODE_TYPE_INTERNAL,
 383   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 384   .error_strings = srv6_as_rewrite_counter_strings,
 385   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 386   .next_nodes = {
 387     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 388     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 389   },
 390 };
 391 /* *INDENT-ON* */
 392
 393
 394 /**
 395  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 396  */
 397 static uword
 398 srv6_as4_rewrite_fn (vlib_main_t * vm,
 399                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 400 {
 401   ip6_sr_main_t *srm = &sr_main;
 402   srv6_as_main_t *sm = &srv6_as_main;
 403   u32 n_left_from, next_index, *from, *to_next;
 404   u32 cnt_packets = 0;
 405
 406   from = vlib_frame_vector_args (frame);
 407   n_left_from = frame->n_vectors;
 408   next_index = node->cached_next_index;
 409
 410   while (n_left_from > 0)
 411     {
 412       u32 n_left_to_next;
 413
 414       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 415
 416       /* TODO: Dual/quad loop */
 417
 418       while (n_left_from > 0 && n_left_to_next > 0)
 419         {
 420           u32 bi0;
 421           vlib_buffer_t *b0;
 422           ip4_header_t *ip0_encap = 0;
 423           ip6_header_t *ip0 = 0;
 424           ip6_sr_localsid_t *ls0;
 425           srv6_as_localsid_t *ls0_mem;
 426           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 427           u16 new_l0 = 0;
 428
 429           bi0 = from[0];
 430           to_next[0] = bi0;
 431           from += 1;
 432           to_next += 1;
 433           n_left_from -= 1;
 434           n_left_to_next -= 1;
 435
 436           b0 = vlib_get_buffer (vm, bi0);
 437           ip0_encap = vlib_buffer_get_current (b0);
 438           ls0 = pool_elt_at_index (srm->localsids,
 439                                    sm->sw_iface_localsid4[vnet_buffer
 440                                                           (b0)->sw_if_index
 441                                                           [VLIB_RX]]);
 442           ls0_mem = ls0->plugin_mem;
 443
 444           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 445             {
 446               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 447               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 448             }
 449           else
 450             {
 451               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 452                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 453
 454               clib_memcpy (((u8 *) ip0_encap) - vec_len (ls0_mem->rewrite),
 455                            ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 456               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 457
 458               ip0 = vlib_buffer_get_current (b0);
 459
 460               /* Update inner IPv4 TTL and checksum */
 461               u32 checksum0;
 462               ip0_encap->ttl -= 1;
 463               checksum0 = ip0_encap->checksum + clib_host_to_net_u16 (0x0100);
 464               checksum0 += checksum0 >= 0xffff;
 465               ip0_encap->checksum = checksum0;
 466
 467               /* Update outer IPv6 length (in case it has changed) */
 468               new_l0 = vec_len (ls0_mem->rewrite) - sizeof (ip6_header_t) +
 469                 clib_net_to_host_u16 (ip0_encap->length);
 470               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 471             }
 472
 473           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 474               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 475             {
 476               srv6_as_rewrite_trace_t *tr =
 477                 vlib_add_trace (vm, node, b0, sizeof *tr);
 478               tr->error = 0;
 479
 480               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 481                 {
 482                   tr->error = 1;
 483                 }
 484               else
 485                 {
 486                   clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
 487                                sizeof tr->src.as_u8);
 488                   clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
 489                                sizeof tr->dst.as_u8);
 490                 }
 491             }
 492
 493           /* Increment per-SID AS rewrite counters */
 494           vlib_increment_combined_counter (((next0 ==
 495                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 496                                             &(sm->invalid_counters) :
 497                                             &(sm->valid_counters)),
 498                                            vm->thread_index, ls0_mem->index,
 499                                            1, vlib_buffer_length_in_chain (vm,
 500                                                                            b0));
 501
 502           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 503                                            n_left_to_next, bi0, next0);
 504
 505           cnt_packets++;
 506         }
 507
 508       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 509     }
 510
 511   /* Update counters */
 512   vlib_node_increment_counter (vm, srv6_as4_rewrite_node.index,
 513                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 514                                cnt_packets);
 515
 516   return frame->n_vectors;
 517 }
 518
 519 /* *INDENT-OFF* */
 520 VLIB_REGISTER_NODE (srv6_as4_rewrite_node) = {
 521   .function = srv6_as4_rewrite_fn,
 522   .name = "srv6-as4-rewrite",
 523   .vector_size = sizeof (u32),
 524   .format_trace = format_srv6_as_rewrite_trace,
 525   .type = VLIB_NODE_TYPE_INTERNAL,
 526   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 527   .error_strings = srv6_as_rewrite_counter_strings,
 528   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 529   .next_nodes = {
 530     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 531     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 532   },
 533 };
 534 /* *INDENT-ON* */
 535
 536
 537 /**
 538  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 539  */
 540 static uword
 541 srv6_as6_rewrite_fn (vlib_main_t * vm,
 542                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 543 {
 544   ip6_sr_main_t *srm = &sr_main;
 545   srv6_as_main_t *sm = &srv6_as_main;
 546   u32 n_left_from, next_index, *from, *to_next;
 547   u32 cnt_packets = 0;
 548
 549   from = vlib_frame_vector_args (frame);
 550   n_left_from = frame->n_vectors;
 551   next_index = node->cached_next_index;
 552
 553   while (n_left_from > 0)
 554     {
 555       u32 n_left_to_next;
 556
 557       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 558
 559       /* TODO: Dual/quad loop */
 560
 561       while (n_left_from > 0 && n_left_to_next > 0)
 562         {
 563           u32 bi0;
 564           vlib_buffer_t *b0;
 565           ip6_header_t *ip0 = 0, *ip0_encap = 0;
 566           ip6_sr_localsid_t *ls0;
 567           srv6_as_localsid_t *ls0_mem;
 568           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 569           u16 new_l0 = 0;
 570
 571           bi0 = from[0];
 572           to_next[0] = bi0;
 573           from += 1;
 574           to_next += 1;
 575           n_left_from -= 1;
 576           n_left_to_next -= 1;
 577
 578           b0 = vlib_get_buffer (vm, bi0);
 579           ip0_encap = vlib_buffer_get_current (b0);
 580           ls0 = pool_elt_at_index (srm->localsids,
 581                                    sm->sw_iface_localsid6[vnet_buffer
 582                                                           (b0)->sw_if_index
 583                                                           [VLIB_RX]]);
 584           ls0_mem = ls0->plugin_mem;
 585
 586           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 587             {
 588               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 589               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 590             }
 591           else
 592             {
 593               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 594                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 595
 596               clib_memcpy (((u8 *) ip0_encap) - vec_len (ls0_mem->rewrite),
 597                            ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 598               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 599
 600               ip0 = vlib_buffer_get_current (b0);
 601
 602               /* Update inner IPv6 hop limit */
 603               ip0_encap->hop_limit -= 1;
 604
 605               /* Update outer IPv6 length (in case it has changed) */
 606               new_l0 = vec_len (ls0_mem->rewrite) +
 607                 clib_net_to_host_u16 (ip0_encap->payload_length);
 608               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 609             }
 610
 611           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 612               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 613             {
 614               srv6_as_rewrite_trace_t *tr =
 615                 vlib_add_trace (vm, node, b0, sizeof *tr);
 616               tr->error = 0;
 617
 618               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 619                 {
 620                   tr->error = 1;
 621                 }
 622               else
 623                 {
 624                   clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
 625                                sizeof tr->src.as_u8);
 626                   clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
 627                                sizeof tr->dst.as_u8);
 628                 }
 629             }
 630
 631           /* Increment per-SID AS rewrite counters */
 632           vlib_increment_combined_counter (((next0 ==
 633                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 634                                             &(sm->invalid_counters) :
 635                                             &(sm->valid_counters)),
 636                                            vm->thread_index, ls0_mem->index,
 637                                            1, vlib_buffer_length_in_chain (vm,
 638                                                                            b0));
 639
 640           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 641                                            n_left_to_next, bi0, next0);
 642
 643           cnt_packets++;
 644         }
 645
 646       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 647     }
 648
 649   /* Update counters */
 650   vlib_node_increment_counter (vm, srv6_as6_rewrite_node.index,
 651                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 652                                cnt_packets);
 653
 654   return frame->n_vectors;
 655 }
 656
 657 /* *INDENT-OFF* */
 658 VLIB_REGISTER_NODE (srv6_as6_rewrite_node) = {
 659   .function = srv6_as6_rewrite_fn,
 660   .name = "srv6-as6-rewrite",
 661   .vector_size = sizeof (u32),
 662   .format_trace = format_srv6_as_rewrite_trace,
 663   .type = VLIB_NODE_TYPE_INTERNAL,
 664   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 665   .error_strings = srv6_as_rewrite_counter_strings,
 666   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 667   .next_nodes = {
 668     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 669     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 670   },
 671 };
 672 /* *INDENT-ON* */
 673
 674 /*
 675 * fd.io coding-style-patch-verification: ON
 676 *
 677 * Local Variables:
 678 * eval: (c-set-style "gnu")
 679 * End:
 680 */