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_ETHERNET))
 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_ETHERNET)
 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
 173   from = vlib_frame_vector_args (frame);
 174   n_left_from = frame->n_vectors;
 175   next_index = node->cached_next_index;
 176
 177   while (n_left_from > 0)
 178     {
 179       u32 n_left_to_next;
 180
 181       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 182
 183       /* TODO: Dual/quad loop */
 184
 185       while (n_left_from > 0 && n_left_to_next > 0)
 186         {
 187           u32 bi0;
 188           vlib_buffer_t *b0;
 189           ip6_header_t *ip0 = 0;
 190           ip6_sr_localsid_t *ls0;
 191           u32 next0 = SRV6_AS_LOCALSID_NEXT_ERROR;
 192
 193           bi0 = from[0];
 194           to_next[0] = bi0;
 195           from += 1;
 196           to_next += 1;
 197           n_left_from -= 1;
 198           n_left_to_next -= 1;
 199
 200           b0 = vlib_get_buffer (vm, bi0);
 201           ip0 = vlib_buffer_get_current (b0);
 202
 203           /* Lookup the SR End behavior based on IP DA (adj) */
 204           ls0 = pool_elt_at_index (sm->localsids,
 205                                    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 206
 207           /* SRH processing */
 208           end_as_processing (b0, ip0, ls0->plugin_mem, &next0);
 209
 210           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 211             {
 212               srv6_as_localsid_trace_t *tr =
 213                 vlib_add_trace (vm, node, b0, sizeof *tr);
 214               tr->localsid_index = ls0 - sm->localsids;
 215             }
 216
 217           /* This increments the SRv6 per LocalSID counters. */
 218           vlib_increment_combined_counter (((next0 ==
 219                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 220                                             &(sm->sr_ls_invalid_counters) :
 221                                             &(sm->sr_ls_valid_counters)),
 222                                            vm->thread_index,
 223                                            ls0 - sm->localsids, 1,
 224                                            vlib_buffer_length_in_chain (vm,
 225                                                                         b0));
 226
 227           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 228                                            n_left_to_next, bi0, next0);
 229         }
 230
 231       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 232     }
 233
 234   return frame->n_vectors;
 235 }
 236
 237 /* *INDENT-OFF* */
 238 VLIB_REGISTER_NODE (srv6_as_localsid_node) = {
 239   .function = srv6_as_localsid_fn,
 240   .name = "srv6-as-localsid",
 241   .vector_size = sizeof (u32),
 242   .format_trace = format_srv6_as_localsid_trace,
 243   .type = VLIB_NODE_TYPE_INTERNAL,
 244   .n_next_nodes = SRV6_AS_LOCALSID_N_NEXT,
 245   .next_nodes = {
 246     [SRV6_AS_LOCALSID_NEXT_REWRITE4] = "ip4-rewrite",
 247     [SRV6_AS_LOCALSID_NEXT_REWRITE6] = "ip6-rewrite",
 248     [SRV6_AS_LOCALSID_NEXT_INTERFACE] = "interface-output",
 249     [SRV6_AS_LOCALSID_NEXT_ERROR] = "error-drop",
 250   },
 251 };
 252 /* *INDENT-ON* */
 253
 254
 255 /******************************* Rewriting node *******************************/
 256
 257 /**
 258  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 259  */
 260 static uword
 261 srv6_as2_rewrite_fn (vlib_main_t * vm,
 262                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 263 {
 264   ip6_sr_main_t *srm = &sr_main;
 265   srv6_as_main_t *sm = &srv6_as_main;
 266   u32 n_left_from, next_index, *from, *to_next;
 267   u32 cnt_packets = 0;
 268
 269   from = vlib_frame_vector_args (frame);
 270   n_left_from = frame->n_vectors;
 271   next_index = node->cached_next_index;
 272
 273   while (n_left_from > 0)
 274     {
 275       u32 n_left_to_next;
 276
 277       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 278
 279       /* TODO: Dual/quad loop */
 280
 281       while (n_left_from > 0 && n_left_to_next > 0)
 282         {
 283           u32 bi0;
 284           vlib_buffer_t *b0;
 285           ethernet_header_t *en0;
 286           ip6_header_t *ip0 = 0;
 287           ip6_sr_localsid_t *ls0;
 288           srv6_as_localsid_t *ls0_mem;
 289           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 290
 291           bi0 = from[0];
 292           to_next[0] = bi0;
 293           from += 1;
 294           to_next += 1;
 295           n_left_from -= 1;
 296           n_left_to_next -= 1;
 297
 298           b0 = vlib_get_buffer (vm, bi0);
 299           en0 = vlib_buffer_get_current (b0);
 300           ls0 = pool_elt_at_index (srm->localsids,
 301                                    sm->sw_iface_localsid2[vnet_buffer
 302                                                           (b0)->sw_if_index
 303                                                           [VLIB_RX]]);
 304           ls0_mem = ls0->plugin_mem;
 305
 306           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 307             {
 308               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 309               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 310             }
 311           else
 312             {
 313               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 314                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 315
 316               clib_memcpy_fast (((u8 *) en0) - vec_len (ls0_mem->rewrite),
 317                                 ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 318               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 319
 320               ip0 = vlib_buffer_get_current (b0);
 321
 322               ip0->payload_length =
 323                 clib_host_to_net_u16 (b0->current_length -
 324                                       sizeof (ip6_header_t));
 325             }
 326
 327           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 328               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 329             {
 330               srv6_as_rewrite_trace_t *tr =
 331                 vlib_add_trace (vm, node, b0, sizeof *tr);
 332               tr->error = 0;
 333
 334               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 335                 {
 336                   tr->error = 1;
 337                 }
 338               else
 339                 {
 340                   clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
 341                                     sizeof tr->src.as_u8);
 342                   clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
 343                                     sizeof tr->dst.as_u8);
 344                 }
 345             }
 346
 347           /* Increment per-SID AS rewrite counters */
 348           vlib_increment_combined_counter (((next0 ==
 349                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 350                                             &(sm->invalid_counters) :
 351                                             &(sm->valid_counters)),
 352                                            vm->thread_index, ls0_mem->index,
 353                                            1, vlib_buffer_length_in_chain (vm,
 354                                                                            b0));
 355
 356           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 357                                            n_left_to_next, bi0, next0);
 358
 359           cnt_packets++;
 360         }
 361
 362       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 363     }
 364
 365   /* Update counters */
 366   vlib_node_increment_counter (vm, srv6_as4_rewrite_node.index,
 367                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 368                                cnt_packets);
 369
 370   return frame->n_vectors;
 371 }
 372
 373 /* *INDENT-OFF* */
 374 VLIB_REGISTER_NODE (srv6_as2_rewrite_node) = {
 375   .function = srv6_as2_rewrite_fn,
 376   .name = "srv6-as2-rewrite",
 377   .vector_size = sizeof (u32),
 378   .format_trace = format_srv6_as_rewrite_trace,
 379   .type = VLIB_NODE_TYPE_INTERNAL,
 380   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 381   .error_strings = srv6_as_rewrite_counter_strings,
 382   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 383   .next_nodes = {
 384     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 385     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 386   },
 387 };
 388 /* *INDENT-ON* */
 389
 390
 391 /**
 392  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 393  */
 394 static uword
 395 srv6_as4_rewrite_fn (vlib_main_t * vm,
 396                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 397 {
 398   ip6_sr_main_t *srm = &sr_main;
 399   srv6_as_main_t *sm = &srv6_as_main;
 400   u32 n_left_from, next_index, *from, *to_next;
 401   u32 cnt_packets = 0;
 402
 403   from = vlib_frame_vector_args (frame);
 404   n_left_from = frame->n_vectors;
 405   next_index = node->cached_next_index;
 406
 407   while (n_left_from > 0)
 408     {
 409       u32 n_left_to_next;
 410
 411       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 412
 413       /* TODO: Dual/quad loop */
 414
 415       while (n_left_from > 0 && n_left_to_next > 0)
 416         {
 417           u32 bi0;
 418           vlib_buffer_t *b0;
 419           ip4_header_t *ip0_encap = 0;
 420           ip6_header_t *ip0 = 0;
 421           ip6_sr_localsid_t *ls0;
 422           srv6_as_localsid_t *ls0_mem;
 423           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 424           u16 new_l0 = 0;
 425
 426           bi0 = from[0];
 427           to_next[0] = bi0;
 428           from += 1;
 429           to_next += 1;
 430           n_left_from -= 1;
 431           n_left_to_next -= 1;
 432
 433           b0 = vlib_get_buffer (vm, bi0);
 434           ip0_encap = vlib_buffer_get_current (b0);
 435           ls0 = pool_elt_at_index (srm->localsids,
 436                                    sm->sw_iface_localsid4[vnet_buffer
 437                                                           (b0)->sw_if_index
 438                                                           [VLIB_RX]]);
 439           ls0_mem = ls0->plugin_mem;
 440
 441           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 442             {
 443               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 444               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 445             }
 446           else
 447             {
 448               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 449                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 450
 451               clib_memcpy_fast (((u8 *) ip0_encap) -
 452                                 vec_len (ls0_mem->rewrite), ls0_mem->rewrite,
 453                                 vec_len (ls0_mem->rewrite));
 454               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 455
 456               ip0 = vlib_buffer_get_current (b0);
 457
 458               /* Update inner IPv4 TTL and checksum */
 459               u32 checksum0;
 460               ip0_encap->ttl -= 1;
 461               checksum0 = ip0_encap->checksum + clib_host_to_net_u16 (0x0100);
 462               checksum0 += checksum0 >= 0xffff;
 463               ip0_encap->checksum = checksum0;
 464
 465               /* Update outer IPv6 length (in case it has changed) */
 466               new_l0 = vec_len (ls0_mem->rewrite) - sizeof (ip6_header_t) +
 467                 clib_net_to_host_u16 (ip0_encap->length);
 468               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 469             }
 470
 471           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 472               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 473             {
 474               srv6_as_rewrite_trace_t *tr =
 475                 vlib_add_trace (vm, node, b0, sizeof *tr);
 476               tr->error = 0;
 477
 478               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 479                 {
 480                   tr->error = 1;
 481                 }
 482               else
 483                 {
 484                   clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
 485                                     sizeof tr->src.as_u8);
 486                   clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
 487                                     sizeof tr->dst.as_u8);
 488                 }
 489             }
 490
 491           /* Increment per-SID AS rewrite counters */
 492           vlib_increment_combined_counter (((next0 ==
 493                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 494                                             &(sm->invalid_counters) :
 495                                             &(sm->valid_counters)),
 496                                            vm->thread_index, ls0_mem->index,
 497                                            1, vlib_buffer_length_in_chain (vm,
 498                                                                            b0));
 499
 500           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 501                                            n_left_to_next, bi0, next0);
 502
 503           cnt_packets++;
 504         }
 505
 506       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 507     }
 508
 509   /* Update counters */
 510   vlib_node_increment_counter (vm, srv6_as4_rewrite_node.index,
 511                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 512                                cnt_packets);
 513
 514   return frame->n_vectors;
 515 }
 516
 517 /* *INDENT-OFF* */
 518 VLIB_REGISTER_NODE (srv6_as4_rewrite_node) = {
 519   .function = srv6_as4_rewrite_fn,
 520   .name = "srv6-as4-rewrite",
 521   .vector_size = sizeof (u32),
 522   .format_trace = format_srv6_as_rewrite_trace,
 523   .type = VLIB_NODE_TYPE_INTERNAL,
 524   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 525   .error_strings = srv6_as_rewrite_counter_strings,
 526   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 527   .next_nodes = {
 528     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 529     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 530   },
 531 };
 532 /* *INDENT-ON* */
 533
 534
 535 /**
 536  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 537  */
 538 static uword
 539 srv6_as6_rewrite_fn (vlib_main_t * vm,
 540                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 541 {
 542   ip6_sr_main_t *srm = &sr_main;
 543   srv6_as_main_t *sm = &srv6_as_main;
 544   u32 n_left_from, next_index, *from, *to_next;
 545   u32 cnt_packets = 0;
 546
 547   from = vlib_frame_vector_args (frame);
 548   n_left_from = frame->n_vectors;
 549   next_index = node->cached_next_index;
 550
 551   while (n_left_from > 0)
 552     {
 553       u32 n_left_to_next;
 554
 555       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 556
 557       /* TODO: Dual/quad loop */
 558
 559       while (n_left_from > 0 && n_left_to_next > 0)
 560         {
 561           u32 bi0;
 562           vlib_buffer_t *b0;
 563           ip6_header_t *ip0 = 0, *ip0_encap = 0;
 564           ip6_sr_localsid_t *ls0;
 565           srv6_as_localsid_t *ls0_mem;
 566           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 567           u16 new_l0 = 0;
 568
 569           bi0 = from[0];
 570           to_next[0] = bi0;
 571           from += 1;
 572           to_next += 1;
 573           n_left_from -= 1;
 574           n_left_to_next -= 1;
 575
 576           b0 = vlib_get_buffer (vm, bi0);
 577           ip0_encap = vlib_buffer_get_current (b0);
 578           ls0 = pool_elt_at_index (srm->localsids,
 579                                    sm->sw_iface_localsid6[vnet_buffer
 580                                                           (b0)->sw_if_index
 581                                                           [VLIB_RX]]);
 582           ls0_mem = ls0->plugin_mem;
 583
 584           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 585             {
 586               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 587               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 588             }
 589           else
 590             {
 591               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 592                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 593
 594               clib_memcpy_fast (((u8 *) ip0_encap) -
 595                                 vec_len (ls0_mem->rewrite), ls0_mem->rewrite,
 596                                 vec_len (ls0_mem->rewrite));
 597               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 598
 599               ip0 = vlib_buffer_get_current (b0);
 600
 601               /* Update inner IPv6 hop limit */
 602               ip0_encap->hop_limit -= 1;
 603
 604               /* Update outer IPv6 length (in case it has changed) */
 605               new_l0 = vec_len (ls0_mem->rewrite) +
 606                 clib_net_to_host_u16 (ip0_encap->payload_length);
 607               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 608             }
 609
 610           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 611               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 612             {
 613               srv6_as_rewrite_trace_t *tr =
 614                 vlib_add_trace (vm, node, b0, sizeof *tr);
 615               tr->error = 0;
 616
 617               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 618                 {
 619                   tr->error = 1;
 620                 }
 621               else
 622                 {
 623                   clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
 624                                     sizeof tr->src.as_u8);
 625                   clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
 626                                     sizeof tr->dst.as_u8);
 627                 }
 628             }
 629
 630           /* Increment per-SID AS rewrite counters */
 631           vlib_increment_combined_counter (((next0 ==
 632                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 633                                             &(sm->invalid_counters) :
 634                                             &(sm->valid_counters)),
 635                                            vm->thread_index, ls0_mem->index,
 636                                            1, vlib_buffer_length_in_chain (vm,
 637                                                                            b0));
 638
 639           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 640                                            n_left_to_next, bi0, next0);
 641
 642           cnt_packets++;
 643         }
 644
 645       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 646     }
 647
 648   /* Update counters */
 649   vlib_node_increment_counter (vm, srv6_as6_rewrite_node.index,
 650                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 651                                cnt_packets);
 652
 653   return frame->n_vectors;
 654 }
 655
 656 /* *INDENT-OFF* */
 657 VLIB_REGISTER_NODE (srv6_as6_rewrite_node) = {
 658   .function = srv6_as6_rewrite_fn,
 659   .name = "srv6-as6-rewrite",
 660   .vector_size = sizeof (u32),
 661   .format_trace = format_srv6_as_rewrite_trace,
 662   .type = VLIB_NODE_TYPE_INTERNAL,
 663   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 664   .error_strings = srv6_as_rewrite_counter_strings,
 665   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 666   .next_nodes = {
 667     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 668     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 669   },
 670 };
 671 /* *INDENT-ON* */
 672
 673 /*
 674 * fd.io coding-style-patch-verification: ON
 675 *
 676 * Local Variables:
 677 * eval: (c-set-style "gnu")
 678 * End:
 679 */