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_N_NEXT,
  96 } srv6_as_localsid_next_t;
  97
  98 typedef enum
  99 {
 100   SRV6_AS_REWRITE_NEXT_ERROR,
 101   SRV6_AS_REWRITE_NEXT_LOOKUP,
 102   SRV6_AS_REWRITE_N_NEXT,
 103 } srv6_as_rewrite_next_t;
 104
 105
 106 /******************************* Local SID node *******************************/
 107
 108 /**
 109  * @brief Function doing SRH processing for AS behavior
 110  */
 111 static_always_inline void
 112 end_as_processing (vlib_buffer_t * b0,
 113                    ip6_header_t * ip0,
 114                    srv6_as_localsid_t * ls0_mem, u32 * next0)
 115 {
 116   u16 encap_len;
 117   ip6_ext_header_t *ext_hdr;
 118   u8 hdr_type;
 119
 120   /* Compute encapsulation headers length */
 121   encap_len = sizeof (ip6_header_t);
 122   ext_hdr = (ip6_ext_header_t *) (ip0 + 1);
 123   hdr_type = ip0->protocol;
 124
 125   while (ip6_ext_hdr (hdr_type))
 126     {
 127       encap_len += ip6_ext_header_len (ext_hdr);
 128       hdr_type = ext_hdr->next_hdr;
 129       ext_hdr = ip6_ext_next_header (ext_hdr);
 130     }
 131
 132   /* Make sure next header is IP */
 133   if (PREDICT_FALSE (hdr_type != IP_PROTOCOL_IPV6 &&
 134                      hdr_type != IP_PROTOCOL_IP_IN_IP))
 135     {
 136       return;
 137     }
 138
 139   /* Remove IP header and extensions */
 140   vlib_buffer_advance (b0, encap_len);
 141
 142   /* Set Xconnect adjacency to VNF */
 143   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0_mem->nh_adj;
 144
 145   if (ls0_mem->ip_version == DA_IP4)
 146     *next0 = SRV6_AS_LOCALSID_NEXT_REWRITE4;
 147   else if (ls0_mem->ip_version == DA_IP6)
 148     *next0 = SRV6_AS_LOCALSID_NEXT_REWRITE6;
 149 }
 150
 151 /**
 152  * @brief SRv6 AS Localsid graph node
 153  */
 154 static uword
 155 srv6_as_localsid_fn (vlib_main_t * vm,
 156                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 157 {
 158   ip6_sr_main_t *sm = &sr_main;
 159   u32 n_left_from, next_index, *from, *to_next;
 160   u32 cnt_packets = 0;
 161
 162   from = vlib_frame_vector_args (frame);
 163   n_left_from = frame->n_vectors;
 164   next_index = node->cached_next_index;
 165
 166   u32 thread_index = vlib_get_thread_index ();
 167
 168   while (n_left_from > 0)
 169     {
 170       u32 n_left_to_next;
 171
 172       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 173
 174       /* TODO: Dual/quad loop */
 175
 176       while (n_left_from > 0 && n_left_to_next > 0)
 177         {
 178           u32 bi0;
 179           vlib_buffer_t *b0;
 180           ip6_header_t *ip0 = 0;
 181           ip6_sr_localsid_t *ls0;
 182           u32 next0 = SRV6_AS_LOCALSID_NEXT_ERROR;
 183
 184           bi0 = from[0];
 185           to_next[0] = bi0;
 186           from += 1;
 187           to_next += 1;
 188           n_left_from -= 1;
 189           n_left_to_next -= 1;
 190
 191           b0 = vlib_get_buffer (vm, bi0);
 192           ip0 = vlib_buffer_get_current (b0);
 193
 194           /* Lookup the SR End behavior based on IP DA (adj) */
 195           ls0 = pool_elt_at_index (sm->localsids,
 196                                    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 197
 198           /* SRH processing */
 199           end_as_processing (b0, ip0, ls0->plugin_mem, &next0);
 200
 201           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 202             {
 203               srv6_as_localsid_trace_t *tr =
 204                 vlib_add_trace (vm, node, b0, sizeof *tr);
 205               tr->localsid_index = ls0 - sm->localsids;
 206             }
 207
 208           /* This increments the SRv6 per LocalSID counters. */
 209           vlib_increment_combined_counter (((next0 ==
 210                                              SRV6_AS_LOCALSID_NEXT_ERROR) ?
 211                                             &(sm->sr_ls_invalid_counters) :
 212                                             &(sm->sr_ls_valid_counters)),
 213                                            thread_index, ls0 - sm->localsids,
 214                                            1, vlib_buffer_length_in_chain (vm,
 215                                                                            b0));
 216
 217           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 218                                            n_left_to_next, bi0, next0);
 219
 220           cnt_packets++;
 221         }
 222
 223       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 224     }
 225
 226   return frame->n_vectors;
 227 }
 228
 229 /* *INDENT-OFF* */
 230 VLIB_REGISTER_NODE (srv6_as_localsid_node) = {
 231   .function = srv6_as_localsid_fn,
 232   .name = "srv6-as-localsid",
 233   .vector_size = sizeof (u32),
 234   .format_trace = format_srv6_as_localsid_trace,
 235   .type = VLIB_NODE_TYPE_INTERNAL,
 236   .n_next_nodes = SRV6_AS_LOCALSID_N_NEXT,
 237   .next_nodes = {
 238     [SRV6_AS_LOCALSID_NEXT_REWRITE4] = "ip4-rewrite",
 239     [SRV6_AS_LOCALSID_NEXT_REWRITE6] = "ip6-rewrite",
 240     [SRV6_AS_LOCALSID_NEXT_ERROR] = "error-drop",
 241   },
 242 };
 243 /* *INDENT-ON* */
 244
 245
 246 /******************************* Rewriting node *******************************/
 247
 248 /**
 249  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 250  */
 251 static uword
 252 srv6_as4_rewrite_fn (vlib_main_t * vm,
 253                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 254 {
 255   ip6_sr_main_t *srm = &sr_main;
 256   srv6_as_main_t *sm = &srv6_as_main;
 257   u32 n_left_from, next_index, *from, *to_next;
 258   u32 cnt_packets = 0;
 259
 260   from = vlib_frame_vector_args (frame);
 261   n_left_from = frame->n_vectors;
 262   next_index = node->cached_next_index;
 263
 264   while (n_left_from > 0)
 265     {
 266       u32 n_left_to_next;
 267
 268       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 269
 270       /* TODO: Dual/quad loop */
 271
 272       while (n_left_from > 0 && n_left_to_next > 0)
 273         {
 274           u32 bi0;
 275           vlib_buffer_t *b0;
 276           ip4_header_t *ip0_encap = 0;
 277           ip6_header_t *ip0 = 0;
 278           ip6_sr_localsid_t *ls0;
 279           srv6_as_localsid_t *ls0_mem;
 280           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 281           u16 new_l0 = 0;
 282
 283           bi0 = from[0];
 284           to_next[0] = bi0;
 285           from += 1;
 286           to_next += 1;
 287           n_left_from -= 1;
 288           n_left_to_next -= 1;
 289
 290           b0 = vlib_get_buffer (vm, bi0);
 291           ip0_encap = vlib_buffer_get_current (b0);
 292           ls0 = pool_elt_at_index (srm->localsids,
 293                                    sm->sw_iface_localsid4[vnet_buffer
 294                                                           (b0)->sw_if_index
 295                                                           [VLIB_RX]]);
 296           ls0_mem = ls0->plugin_mem;
 297
 298           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 299             {
 300               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 301               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 302             }
 303           else
 304             {
 305               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 306                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 307
 308               clib_memcpy (((u8 *) ip0_encap) - vec_len (ls0_mem->rewrite),
 309                            ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 310               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 311
 312               ip0 = vlib_buffer_get_current (b0);
 313
 314               /* Update inner IPv4 TTL and checksum */
 315               u32 checksum0;
 316               ip0_encap->ttl -= 1;
 317               checksum0 = ip0_encap->checksum + clib_host_to_net_u16 (0x0100);
 318               checksum0 += checksum0 >= 0xffff;
 319               ip0_encap->checksum = checksum0;
 320
 321               /* Update outer IPv6 length (in case it has changed) */
 322               new_l0 = vec_len (ls0_mem->rewrite) - sizeof (ip6_header_t) +
 323                 clib_net_to_host_u16 (ip0_encap->length);
 324               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 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 (tr->src.as_u8, ip0->src_address.as_u8,
 341                                sizeof tr->src.as_u8);
 342                   clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
 343                                sizeof tr->dst.as_u8);
 344                 }
 345             }
 346
 347           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 348                                            n_left_to_next, bi0, next0);
 349
 350           cnt_packets++;
 351         }
 352
 353       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 354     }
 355
 356   /* Update counters */
 357   vlib_node_increment_counter (vm, srv6_as4_rewrite_node.index,
 358                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 359                                cnt_packets);
 360
 361   return frame->n_vectors;
 362 }
 363
 364 /* *INDENT-OFF* */
 365 VLIB_REGISTER_NODE (srv6_as4_rewrite_node) = {
 366   .function = srv6_as4_rewrite_fn,
 367   .name = "srv6-as4-rewrite",
 368   .vector_size = sizeof (u32),
 369   .format_trace = format_srv6_as_rewrite_trace,
 370   .type = VLIB_NODE_TYPE_INTERNAL,
 371   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 372   .error_strings = srv6_as_rewrite_counter_strings,
 373   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 374   .next_nodes = {
 375     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 376     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 377   },
 378 };
 379 /* *INDENT-ON* */
 380
 381
 382 /**
 383  * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 384  */
 385 static uword
 386 srv6_as6_rewrite_fn (vlib_main_t * vm,
 387                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 388 {
 389   ip6_sr_main_t *srm = &sr_main;
 390   srv6_as_main_t *sm = &srv6_as_main;
 391   u32 n_left_from, next_index, *from, *to_next;
 392   u32 cnt_packets = 0;
 393
 394   from = vlib_frame_vector_args (frame);
 395   n_left_from = frame->n_vectors;
 396   next_index = node->cached_next_index;
 397
 398   while (n_left_from > 0)
 399     {
 400       u32 n_left_to_next;
 401
 402       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 403
 404       /* TODO: Dual/quad loop */
 405
 406       while (n_left_from > 0 && n_left_to_next > 0)
 407         {
 408           u32 bi0;
 409           vlib_buffer_t *b0;
 410           ip6_header_t *ip0 = 0, *ip0_encap = 0;
 411           ip6_sr_localsid_t *ls0;
 412           srv6_as_localsid_t *ls0_mem;
 413           u32 next0 = SRV6_AS_REWRITE_NEXT_LOOKUP;
 414           u16 new_l0 = 0;
 415
 416           bi0 = from[0];
 417           to_next[0] = bi0;
 418           from += 1;
 419           to_next += 1;
 420           n_left_from -= 1;
 421           n_left_to_next -= 1;
 422
 423           b0 = vlib_get_buffer (vm, bi0);
 424           ip0_encap = vlib_buffer_get_current (b0);
 425           ls0 = pool_elt_at_index (srm->localsids,
 426                                    sm->sw_iface_localsid6[vnet_buffer
 427                                                           (b0)->sw_if_index
 428                                                           [VLIB_RX]]);
 429           ls0_mem = ls0->plugin_mem;
 430
 431           if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
 432             {
 433               next0 = SRV6_AS_REWRITE_NEXT_ERROR;
 434               b0->error = node->errors[SRV6_AS_REWRITE_COUNTER_NO_RW];
 435             }
 436           else
 437             {
 438               ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
 439                       (vec_len (ls0_mem->rewrite) + b0->current_data));
 440
 441               clib_memcpy (((u8 *) ip0_encap) - vec_len (ls0_mem->rewrite),
 442                            ls0_mem->rewrite, vec_len (ls0_mem->rewrite));
 443               vlib_buffer_advance (b0, -(word) vec_len (ls0_mem->rewrite));
 444
 445               ip0 = vlib_buffer_get_current (b0);
 446
 447               /* Update inner IPv6 hop limit */
 448               ip0_encap->hop_limit -= 1;
 449
 450               /* Update outer IPv6 length (in case it has changed) */
 451               new_l0 = vec_len (ls0_mem->rewrite) +
 452                 clib_net_to_host_u16 (ip0_encap->payload_length);
 453               ip0->payload_length = clib_host_to_net_u16 (new_l0);
 454             }
 455
 456           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 457               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 458             {
 459               srv6_as_rewrite_trace_t *tr =
 460                 vlib_add_trace (vm, node, b0, sizeof *tr);
 461               tr->error = 0;
 462
 463               if (next0 == SRV6_AS_REWRITE_NEXT_ERROR)
 464                 {
 465                   tr->error = 1;
 466                 }
 467               else
 468                 {
 469                   clib_memcpy (tr->src.as_u8, ip0->src_address.as_u8,
 470                                sizeof tr->src.as_u8);
 471                   clib_memcpy (tr->dst.as_u8, ip0->dst_address.as_u8,
 472                                sizeof tr->dst.as_u8);
 473                 }
 474             }
 475
 476           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 477                                            n_left_to_next, bi0, next0);
 478
 479           cnt_packets++;
 480         }
 481
 482       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 483     }
 484
 485   /* Update counters */
 486   vlib_node_increment_counter (vm, srv6_as6_rewrite_node.index,
 487                                SRV6_AS_REWRITE_COUNTER_PROCESSED,
 488                                cnt_packets);
 489
 490   return frame->n_vectors;
 491 }
 492
 493 /* *INDENT-OFF* */
 494 VLIB_REGISTER_NODE (srv6_as6_rewrite_node) = {
 495   .function = srv6_as6_rewrite_fn,
 496   .name = "srv6-as6-rewrite",
 497   .vector_size = sizeof (u32),
 498   .format_trace = format_srv6_as_rewrite_trace,
 499   .type = VLIB_NODE_TYPE_INTERNAL,
 500   .n_errors = SRV6_AS_REWRITE_N_COUNTERS,
 501   .error_strings = srv6_as_rewrite_counter_strings,
 502   .n_next_nodes = SRV6_AS_REWRITE_N_NEXT,
 503   .next_nodes = {
 504     [SRV6_AS_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 505     [SRV6_AS_REWRITE_NEXT_ERROR] = "error-drop",
 506   },
 507 };
 508 /* *INDENT-ON* */
 509
 510 /*
 511 * fd.io coding-style-patch-verification: ON
 512 *
 513 * Local Variables:
 514 * eval: (c-set-style "gnu")
 515 * End:
 516 */