src/vnet/ipip/sixrd.c

   1 /*
   2  * sixrd.c - 6RD specific functions (RFC5969)
   3  *
   4  * Copyright (c) 2018 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 /**
  19  * This code supports the following sixrd modes:
  20  *
  21  * 32 EA bits (Complete IPv4 address is embedded):
  22  *   ea_bits_len = 32
  23  * IPv4 suffix is embedded:
  24  *   ea_bits_len = < 32
  25  * No embedded address bits (1:1 mode):
  26  *   ea_bits_len = 0
  27  */
  28
  29 #include "ipip.h"
  30 #include <vlibapi/api.h>
  31 #include <vlibmemory/api.h>
  32 #include <vnet/adj/adj.h>
  33 #include <vnet/adj/adj_delegate.h>
  34 #include <vnet/adj/adj_midchain.h>
  35 #include <vnet/dpo/lookup_dpo.h>
  36 #include <vnet/fib/fib_table.h>
  37 #include <vnet/fib/ip6_fib.h>
  38 #include <vnet/plugin/plugin.h>
  39 #include <vpp/app/version.h>    // Really needed?
  40
  41 extern vlib_node_registration_t ip4_sixrd_node;
  42
  43 /**
  44  * Adj delegate data
  45  */
  46 typedef struct sixrd_adj_delegate_t_
  47 {
  48   u32 adj_index;
  49   fib_node_t sixrd_node;
  50   fib_node_index_t sixrd_fib_entry_index;
  51   u32 sixrd_sibling;
  52 } sixrd_adj_delegate_t;
  53
  54 /**
  55  * Pool of delegate structs
  56  */
  57 static sixrd_adj_delegate_t *sixrd_adj_delegate_pool;
  58
  59 /**
  60  * Adj delegate registered type
  61  */
  62 static adj_delegate_type_t sixrd_adj_delegate_type;
  63
  64 /**
  65  * FIB node registered type
  66  */
  67 static fib_node_type_t sixrd_fib_node_type;
  68
  69 static inline sixrd_adj_delegate_t *
  70 sixrd_adj_from_base (adj_delegate_t * ad)
  71 {
  72   if (ad == NULL)
  73     return (NULL);
  74   return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
  75 }
  76
  77 static inline const sixrd_adj_delegate_t *
  78 sixrd_adj_from_const_base (const adj_delegate_t * ad)
  79 {
  80   if (ad == NULL)
  81     {
  82       return (NULL);
  83     }
  84   return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
  85 }
  86
  87 static void
  88 sixrd_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
  89              const void *data)
  90 {
  91   ip4_header_t *ip4 = vlib_buffer_get_current (b0);
  92   ip6_header_t *ip6 = vlib_buffer_get_current (b0) + sizeof (ip4_header_t);
  93   const ipip_tunnel_t *t = data;
  94
  95   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
  96   ip4->dst_address.as_u32 =
  97     sixrd_get_addr_net (t, ip6->dst_address.as_u64[0]);
  98   ip4->checksum = ip4_header_checksum (ip4);
  99 }
 100
 101 static void
 102 ip6ip_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
 103              const void *data)
 104 {
 105   const ipip_tunnel_t *t = data;
 106   ip4_header_t *ip4 = vlib_buffer_get_current (b0);
 107   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
 108   ip4->dst_address.as_u32 =
 109     sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
 110   ip4->checksum = ip4_header_checksum (ip4);
 111 }
 112
 113 static u8 *
 114 sixrd_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
 115                      vnet_link_t link_type, const void *dst_address)
 116 {
 117   u8 *rewrite = NULL;
 118   ipip_tunnel_t *t;
 119
 120   t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 121   if (!t)
 122     return 0;
 123
 124   vec_validate (rewrite, sizeof (ip4_header_t) - 1);
 125   ip4_header_t *ip4 = (ip4_header_t *) rewrite;
 126   ip4->ip_version_and_header_length = 0x45;
 127   ip4->ttl = 64;
 128   ip4->protocol = IP_PROTOCOL_IPV6;
 129   /* fixup ip4 header length and checksum after-the-fact */
 130   ip4->src_address.as_u32 = t->tunnel_src.ip4.as_u32;
 131   ip4->dst_address.as_u32 = 0;
 132   ip4->checksum = ip4_header_checksum (ip4);
 133
 134   return rewrite;
 135 }
 136
 137 static void
 138 ip6ip_tunnel_stack (adj_index_t ai, u32 fib_entry_index)
 139 {
 140   ip_adjacency_t *adj = adj_get (ai);
 141   ipip_tunnel_t *t;
 142   u32 sw_if_index = adj->rewrite_header.sw_if_index;
 143
 144   t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 145   if (!t)
 146     return;
 147
 148   /*
 149    * find the adjacency that is contributed by the FIB entry
 150    * that this tunnel resolves via, and use it as the next adj
 151    * in the midchain
 152    */
 153   if (vnet_hw_interface_get_flags (vnet_get_main (), t->hw_if_index) &
 154       VNET_HW_INTERFACE_FLAG_LINK_UP)
 155     {
 156       adj_nbr_midchain_stack (ai,
 157                               fib_entry_contribute_ip_forwarding
 158                               (fib_entry_index));
 159     }
 160   else
 161     {
 162       adj_nbr_midchain_unstack (ai);
 163     }
 164 }
 165
 166 static void
 167 sixrd_tunnel_stack (adj_index_t ai, u32 fib_index)
 168 {
 169   dpo_id_t dpo = DPO_INVALID;
 170   ip_adjacency_t *adj = adj_get (ai);
 171   u32 sw_if_index = adj->rewrite_header.sw_if_index;
 172
 173   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 174   if (!t)
 175     return;
 176
 177   lookup_dpo_add_or_lock_w_fib_index (fib_index, DPO_PROTO_IP4,
 178                                       LOOKUP_UNICAST, LOOKUP_INPUT_DST_ADDR,
 179                                       LOOKUP_TABLE_FROM_CONFIG, &dpo);
 180   adj_nbr_midchain_stack (ai, &dpo);
 181 }
 182
 183 const static ip46_address_t sixrd_special_nh = {
 184   .ip6 = {
 185           .as_u64 = {
 186                      [0] = 0xffffffffffffffff,
 187                      [1] = 0xffffffffffffffff,
 188                      },
 189           },
 190 };
 191
 192 static void
 193 sixrd_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 194 {
 195   ip_adjacency_t *adj = adj_get (ai);
 196   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 197
 198   if (!memcmp (&sixrd_special_nh, &adj->sub_type.nbr.next_hop,
 199                sizeof (sixrd_special_nh)))
 200     {
 201       adj_nbr_midchain_update_rewrite (ai, sixrd_fixup, t, ADJ_FLAG_NONE,
 202                                        sixrd_build_rewrite (vnm, sw_if_index,
 203                                                             adj_get_link_type
 204                                                             (ai), NULL));
 205       sixrd_tunnel_stack (ai, t->fib_index);
 206     }
 207   else
 208     {
 209       sixrd_adj_delegate_t *sixrd_ad;
 210       ip4_address_t da4;
 211
 212       da4.as_u32 =
 213         sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
 214
 215       fib_prefix_t pfx = {
 216         .fp_proto = FIB_PROTOCOL_IP4,
 217         .fp_len = 32,
 218         .fp_addr = {
 219                     .ip4 = da4,
 220                     }
 221         ,
 222       };
 223
 224       adj_nbr_midchain_update_rewrite (ai, ip6ip_fixup, t, ADJ_FLAG_NONE,
 225                                        sixrd_build_rewrite (vnm, sw_if_index,
 226                                                             adj_get_link_type
 227                                                             (ai), NULL));
 228
 229       sixrd_ad =
 230         sixrd_adj_from_base (adj_delegate_get (adj, sixrd_adj_delegate_type));
 231       if (sixrd_ad == NULL)
 232         {
 233           pool_get (sixrd_adj_delegate_pool, sixrd_ad);
 234           fib_node_init (&sixrd_ad->sixrd_node, sixrd_fib_node_type);
 235           sixrd_ad->adj_index = ai;
 236           sixrd_ad->sixrd_fib_entry_index =
 237             fib_table_entry_special_add (t->fib_index, &pfx, FIB_SOURCE_RR,
 238                                          FIB_ENTRY_FLAG_NONE);
 239           sixrd_ad->sixrd_sibling =
 240             fib_entry_child_add (sixrd_ad->sixrd_fib_entry_index,
 241                                  sixrd_fib_node_type,
 242                                  sixrd_ad - sixrd_adj_delegate_pool);
 243
 244           adj_delegate_add (adj, sixrd_adj_delegate_type,
 245                             sixrd_ad - sixrd_adj_delegate_pool);
 246
 247           ip6ip_tunnel_stack (ai, sixrd_ad->sixrd_fib_entry_index);
 248         }
 249     }
 250 }
 251
 252 clib_error_t *
 253 sixrd_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 254 {
 255   /* Always up */
 256   vnet_hw_interface_set_flags (vnm, hw_if_index,
 257                                VNET_HW_INTERFACE_FLAG_LINK_UP);
 258   return /* no error */ 0;
 259 }
 260
 261 /* *INDENT-OFF* */
 262 VNET_HW_INTERFACE_CLASS(sixrd_hw_interface_class) = {
 263     .name = "ip6ip-6rd",
 264     .build_rewrite = sixrd_build_rewrite,
 265     .update_adjacency = sixrd_update_adj,
 266 };
 267
 268 VNET_DEVICE_CLASS(sixrd_device_class) = {
 269     .name = "ip6ip-6rd",
 270     .admin_up_down_function = sixrd_interface_admin_up_down,
 271 #ifdef SOON
 272     .clear counter = 0;
 273 #endif
 274 }
 275 ;
 276 /* *INDENT-ON* */
 277
 278 int
 279 sixrd_add_tunnel (ip6_address_t * ip6_prefix, u8 ip6_prefix_len,
 280                   ip4_address_t * ip4_prefix, u8 ip4_prefix_len,
 281                   ip4_address_t * ip4_src, bool security_check,
 282                   u32 fib_index, u32 * sw_if_index)
 283 {
 284   ipip_main_t *gm = &ipip_main;
 285   ipip_tunnel_t *t;
 286
 287   if (fib_index == ~0)
 288     return VNET_API_ERROR_NO_SUCH_FIB;
 289
 290   if ((ip6_prefix_len + 32 - ip4_prefix_len) > 64)
 291     return VNET_API_ERROR_INVALID_VALUE;
 292
 293   /* Tunnel already configured */
 294   ip46_address_t src = ip46_address_initializer, dst =
 295     ip46_address_initializer;
 296   ip_set (&src, ip4_src, true);
 297   ipip_tunnel_key_t key = {.transport = IPIP_TRANSPORT_IP4,
 298     .fib_index = fib_index,
 299     .src = src,
 300     .dst = dst
 301   };
 302
 303   t = ipip_tunnel_db_find (&key);
 304   if (t)
 305     return VNET_API_ERROR_IF_ALREADY_EXISTS;
 306
 307   /* Get tunnel index */
 308   pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
 309   memset (t, 0, sizeof (*t));
 310   u32 t_idx = t - gm->tunnels;  /* tunnel index (or instance) */
 311
 312   /* Init tunnel struct */
 313   t->mode = IPIP_MODE_6RD;
 314   t->sixrd.ip4_prefix.as_u32 = ip4_prefix->as_u32;
 315   t->sixrd.ip4_prefix_len = ip4_prefix_len;
 316   t->sixrd.ip6_prefix = *ip6_prefix;
 317   t->sixrd.ip6_prefix_len = ip6_prefix_len;
 318   t->tunnel_src = src;
 319   t->sixrd.security_check = security_check;
 320   t->sixrd.shift =
 321     (ip4_prefix_len < 32) ? 64 - ip6_prefix_len - (32 - ip4_prefix_len) : 0;
 322
 323   /* Create interface */
 324   u32 hw_if_index =
 325     vnet_register_interface (vnet_get_main (), sixrd_device_class.index,
 326                              t_idx,
 327                              sixrd_hw_interface_class.index, t_idx);
 328
 329   /* Default the interface to up and enable IPv6 (payload) */
 330   vnet_hw_interface_t *hi =
 331     vnet_get_hw_interface (vnet_get_main (), hw_if_index);
 332   t->hw_if_index = hw_if_index;
 333   t->fib_index = fib_index;
 334   t->sw_if_index = hi->sw_if_index;
 335   t->dev_instance = t_idx;
 336   t->user_instance = t_idx;
 337
 338   hi->max_l3_packet_bytes[VLIB_RX] = hi->max_l3_packet_bytes[VLIB_TX] = 1480;
 339
 340   ipip_tunnel_db_add (t, &key);
 341
 342   vec_validate_init_empty (gm->tunnel_index_by_sw_if_index, hi->sw_if_index,
 343                            ~0);
 344   gm->tunnel_index_by_sw_if_index[hi->sw_if_index] = t_idx;
 345
 346   vnet_hw_interface_set_flags (vnet_get_main (), hw_if_index,
 347                                VNET_HW_INTERFACE_FLAG_LINK_UP);
 348   vnet_sw_interface_set_flags (vnet_get_main (), hi->sw_if_index,
 349                                VNET_SW_INTERFACE_FLAG_ADMIN_UP);
 350   ip6_sw_interface_enable_disable (hi->sw_if_index, true);
 351
 352   /* Create IPv6 route/adjacency */
 353   fib_prefix_t pfx6 = {
 354     .fp_proto = FIB_PROTOCOL_IP6,
 355     .fp_len = t->sixrd.ip6_prefix_len,
 356     .fp_addr = {
 357                 .ip6 = t->sixrd.ip6_prefix,
 358                 }
 359     ,
 360   };
 361
 362   fib_table_entry_update_one_path (fib_index, &pfx6, FIB_SOURCE_CLI,
 363                                    FIB_ENTRY_FLAG_ATTACHED, DPO_PROTO_IP6,
 364                                    &sixrd_special_nh, hi->sw_if_index, ~0, 1,
 365                                    NULL, FIB_ROUTE_PATH_FLAG_NONE);
 366
 367   *sw_if_index = hi->sw_if_index;
 368
 369   if (!gm->ip4_protocol_registered)
 370     {
 371       vlib_node_t *ipip4_input =
 372         vlib_get_node_by_name (gm->vlib_main, (u8 *) "ipip4-input");
 373       ASSERT (ipip4_input);
 374       ip4_register_protocol (IP_PROTOCOL_IPV6, ipip4_input->index);
 375     }
 376   return 0;
 377 }
 378
 379 /*
 380  * sixrd_del_tunnel
 381  */
 382 int
 383 sixrd_del_tunnel (u32 sw_if_index)
 384 {
 385   ipip_main_t *gm = &ipip_main;
 386   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 387
 388   if (!t)
 389     {
 390       clib_warning ("SIXRD tunnel delete: tunnel does not exist: %d",
 391                     sw_if_index);
 392       return -1;
 393     }
 394
 395   fib_prefix_t pfx6 = {
 396     .fp_proto = FIB_PROTOCOL_IP6,
 397     .fp_len = t->sixrd.ip6_prefix_len,
 398     .fp_addr = {
 399                 .ip6 = t->sixrd.ip6_prefix,
 400                 }
 401     ,
 402   };
 403   fib_table_entry_special_remove (0, &pfx6, FIB_SOURCE_CLI);
 404   vnet_sw_interface_set_flags (vnet_get_main (), t->sw_if_index,
 405                                0 /* down */ );
 406   ip6_sw_interface_enable_disable (t->sw_if_index, false);
 407   gm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0;
 408
 409   vnet_delete_hw_interface (vnet_get_main (), t->hw_if_index);
 410   ipip_tunnel_db_remove (t);
 411   pool_put (gm->tunnels, t);
 412
 413   return 0;
 414 }
 415
 416 static void
 417 sixrd_adj_delegate_adj_deleted (adj_delegate_t * aed)
 418 {
 419   sixrd_adj_delegate_t *sixrd_ad;
 420
 421   sixrd_ad = sixrd_adj_from_base (aed);
 422   fib_entry_child_remove (sixrd_ad->sixrd_fib_entry_index,
 423                           sixrd_ad->sixrd_sibling);
 424   fib_table_entry_delete_index (sixrd_ad->sixrd_fib_entry_index,
 425                                 FIB_SOURCE_RR);
 426   pool_put (sixrd_adj_delegate_pool, sixrd_ad);
 427 }
 428
 429 static u8 *
 430 sixrd_adj_delegate_format (const adj_delegate_t * aed, u8 * s)
 431 {
 432   const sixrd_adj_delegate_t *sixrd_ad;
 433
 434   sixrd_ad = sixrd_adj_from_const_base (aed);
 435   s = format (s, "SIXRD:[fib-entry:%d]", sixrd_ad->sixrd_fib_entry_index);
 436
 437   return (s);
 438 }
 439
 440 static void
 441 sixrd_fib_node_last_lock_gone (fib_node_t * node)
 442 {
 443   /* top of the dependency tree, locks not managed here. */
 444 }
 445
 446 static sixrd_adj_delegate_t *
 447 sixrd_adj_delegate_from_fib_node (fib_node_t * node)
 448 {
 449   return ((sixrd_adj_delegate_t *) (((char *) node) -
 450                                     STRUCT_OFFSET_OF (sixrd_adj_delegate_t,
 451                                                       sixrd_node)));
 452 }
 453
 454 static fib_node_back_walk_rc_t
 455 sixrd_fib_node_back_walk_notify (fib_node_t * node,
 456                                  fib_node_back_walk_ctx_t * ctx)
 457 {
 458   sixrd_adj_delegate_t *sixrd_ad;
 459
 460   sixrd_ad = sixrd_adj_delegate_from_fib_node (node);
 461   ip6ip_tunnel_stack (sixrd_ad->adj_index, sixrd_ad->sixrd_fib_entry_index);
 462
 463   return (FIB_NODE_BACK_WALK_CONTINUE);
 464 }
 465
 466 /**
 467  * Function definition to get a FIB node from its index
 468  */
 469 static fib_node_t *
 470 sixrd_fib_node_get (fib_node_index_t index)
 471 {
 472   sixrd_adj_delegate_t *sixrd_ad;
 473
 474   sixrd_ad = pool_elt_at_index (sixrd_adj_delegate_pool, index);
 475
 476   return (&sixrd_ad->sixrd_node);
 477 }
 478
 479 /**
 480  * VFT registered with the adjacency delegate
 481  */
 482 const static adj_delegate_vft_t sixrd_adj_delegate_vft = {
 483   .adv_adj_deleted = sixrd_adj_delegate_adj_deleted,
 484   .adv_format = sixrd_adj_delegate_format,
 485 };
 486
 487 /**
 488  * VFT registered with the FIB node for the adj delegate
 489  */
 490 const static fib_node_vft_t sixrd_fib_node_vft = {
 491   .fnv_get = sixrd_fib_node_get,
 492   .fnv_last_lock = sixrd_fib_node_last_lock_gone,
 493   .fnv_back_walk = sixrd_fib_node_back_walk_notify,
 494 };
 495
 496 static clib_error_t *
 497 sixrd_init (vlib_main_t * vm)
 498 {
 499   clib_error_t *error = 0;
 500
 501   /* Make sure the IPIP tunnel subsystem is initialised */
 502   vlib_call_init_function (vm, ipip_init);
 503
 504   sixrd_adj_delegate_type =
 505     adj_delegate_register_new_type (&sixrd_adj_delegate_vft);
 506   sixrd_fib_node_type = fib_node_register_new_type (&sixrd_fib_node_vft);
 507
 508   return error;
 509 }
 510
 511 VLIB_INIT_FUNCTION (sixrd_init);
 512
 513 /*
 514  * fd.io coding-style-patch-verification: ON
 515  *
 516  * Local Variables:
 517  * eval: (c-set-style "gnu")
 518  * End:
 519  */