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
  40 extern vlib_node_registration_t ip4_sixrd_node;
  41
  42 /**
  43  * Adj delegate data
  44  */
  45 typedef struct sixrd_adj_delegate_t_
  46 {
  47   u32 adj_index;
  48   fib_node_t sixrd_node;
  49   fib_node_index_t sixrd_fib_entry_index;
  50   u32 sixrd_sibling;
  51 } sixrd_adj_delegate_t;
  52
  53 /**
  54  * Pool of delegate structs
  55  */
  56 static sixrd_adj_delegate_t *sixrd_adj_delegate_pool;
  57
  58 /**
  59  * Adj delegate registered type
  60  */
  61 static adj_delegate_type_t sixrd_adj_delegate_type;
  62
  63 /**
  64  * FIB node registered type
  65  */
  66 static fib_node_type_t sixrd_fib_node_type;
  67
  68 static inline sixrd_adj_delegate_t *
  69 sixrd_adj_from_base (adj_delegate_t * ad)
  70 {
  71   if (ad == NULL)
  72     return (NULL);
  73   return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
  74 }
  75
  76 static inline const sixrd_adj_delegate_t *
  77 sixrd_adj_from_const_base (const adj_delegate_t * ad)
  78 {
  79   if (ad == NULL)
  80     {
  81       return (NULL);
  82     }
  83   return (pool_elt_at_index (sixrd_adj_delegate_pool, ad->ad_index));
  84 }
  85
  86 static void
  87 sixrd_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
  88              const void *data)
  89 {
  90   ip4_header_t *ip4 = vlib_buffer_get_current (b0);
  91   ip6_header_t *ip6 = vlib_buffer_get_current (b0) + sizeof (ip4_header_t);
  92   const ipip_tunnel_t *t = data;
  93
  94   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
  95   ip4->dst_address.as_u32 =
  96     sixrd_get_addr_net (t, ip6->dst_address.as_u64[0]);
  97   ip4->checksum = ip4_header_checksum (ip4);
  98 }
  99
 100 static void
 101 ip6ip_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0,
 102              const void *data)
 103 {
 104   const ipip_tunnel_t *t = data;
 105   ip4_header_t *ip4 = vlib_buffer_get_current (b0);
 106   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
 107   ip4->dst_address.as_u32 =
 108     sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
 109   ip4->checksum = ip4_header_checksum (ip4);
 110 }
 111
 112 static u8 *
 113 sixrd_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
 114                      vnet_link_t link_type, const void *dst_address)
 115 {
 116   u8 *rewrite = NULL;
 117   ipip_tunnel_t *t;
 118
 119   t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 120   if (!t)
 121     return 0;
 122
 123   vec_validate (rewrite, sizeof (ip4_header_t) - 1);
 124   ip4_header_t *ip4 = (ip4_header_t *) rewrite;
 125   ip4->ip_version_and_header_length = 0x45;
 126   ip4->ttl = 64;
 127   ip4->protocol = IP_PROTOCOL_IPV6;
 128   /* fixup ip4 header length and checksum after-the-fact */
 129   ip4->src_address.as_u32 = t->tunnel_src.ip4.as_u32;
 130   ip4->dst_address.as_u32 = 0;
 131   ip4->checksum = ip4_header_checksum (ip4);
 132
 133   return rewrite;
 134 }
 135
 136 static void
 137 ip6ip_tunnel_stack (adj_index_t ai, u32 fib_entry_index)
 138 {
 139   ip_adjacency_t *adj = adj_get (ai);
 140   ipip_tunnel_t *t;
 141   u32 sw_if_index = adj->rewrite_header.sw_if_index;
 142
 143   t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 144   if (!t)
 145     return;
 146
 147   /*
 148    * find the adjacency that is contributed by the FIB entry
 149    * that this tunnel resolves via, and use it as the next adj
 150    * in the midchain
 151    */
 152   if (vnet_hw_interface_get_flags (vnet_get_main (), t->hw_if_index) &
 153       VNET_HW_INTERFACE_FLAG_LINK_UP)
 154     {
 155       adj_nbr_midchain_stack (ai,
 156                               fib_entry_contribute_ip_forwarding
 157                               (fib_entry_index));
 158     }
 159   else
 160     {
 161       adj_nbr_midchain_unstack (ai);
 162     }
 163 }
 164
 165 static void
 166 sixrd_tunnel_stack (adj_index_t ai, u32 fib_index)
 167 {
 168   dpo_id_t dpo = DPO_INVALID;
 169   ip_adjacency_t *adj = adj_get (ai);
 170   u32 sw_if_index = adj->rewrite_header.sw_if_index;
 171
 172   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 173   if (!t)
 174     return;
 175
 176   lookup_dpo_add_or_lock_w_fib_index (fib_index, DPO_PROTO_IP4,
 177                                       LOOKUP_UNICAST, LOOKUP_INPUT_DST_ADDR,
 178                                       LOOKUP_TABLE_FROM_CONFIG, &dpo);
 179   adj_nbr_midchain_stack (ai, &dpo);
 180 }
 181
 182 const static ip46_address_t sixrd_special_nh = {
 183   .ip6 = {
 184           .as_u64 = {
 185                      [0] = 0xffffffffffffffff,
 186                      [1] = 0xffffffffffffffff,
 187                      },
 188           },
 189 };
 190
 191 static void
 192 sixrd_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 193 {
 194   ip_adjacency_t *adj = adj_get (ai);
 195   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 196
 197   /* Not our tunnel */
 198   if (!t)
 199     return;
 200   if (!memcmp (&sixrd_special_nh, &adj->sub_type.nbr.next_hop,
 201                sizeof (sixrd_special_nh)))
 202     {
 203       adj_nbr_midchain_update_rewrite (ai, sixrd_fixup, t, ADJ_FLAG_NONE,
 204                                        sixrd_build_rewrite (vnm, sw_if_index,
 205                                                             adj_get_link_type
 206                                                             (ai), NULL));
 207       sixrd_tunnel_stack (ai, t->fib_index);
 208     }
 209   else
 210     {
 211       sixrd_adj_delegate_t *sixrd_ad;
 212       ip4_address_t da4;
 213
 214       da4.as_u32 =
 215         sixrd_get_addr_net (t, adj->sub_type.nbr.next_hop.as_u64[0]);
 216
 217       fib_prefix_t pfx = {
 218         .fp_proto = FIB_PROTOCOL_IP4,
 219         .fp_len = 32,
 220         .fp_addr = {
 221                     .ip4 = da4,
 222                     }
 223         ,
 224       };
 225
 226       adj_nbr_midchain_update_rewrite (ai, ip6ip_fixup, t, ADJ_FLAG_NONE,
 227                                        sixrd_build_rewrite (vnm, sw_if_index,
 228                                                             adj_get_link_type
 229                                                             (ai), NULL));
 230
 231       sixrd_ad =
 232         sixrd_adj_from_base (adj_delegate_get (adj, sixrd_adj_delegate_type));
 233       if (sixrd_ad == NULL)
 234         {
 235           pool_get (sixrd_adj_delegate_pool, sixrd_ad);
 236           fib_node_init (&sixrd_ad->sixrd_node, sixrd_fib_node_type);
 237           sixrd_ad->adj_index = ai;
 238           sixrd_ad->sixrd_fib_entry_index =
 239             fib_table_entry_special_add (t->fib_index, &pfx, FIB_SOURCE_RR,
 240                                          FIB_ENTRY_FLAG_NONE);
 241           sixrd_ad->sixrd_sibling =
 242             fib_entry_child_add (sixrd_ad->sixrd_fib_entry_index,
 243                                  sixrd_fib_node_type,
 244                                  sixrd_ad - sixrd_adj_delegate_pool);
 245
 246           adj_delegate_add (adj, sixrd_adj_delegate_type,
 247                             sixrd_ad - sixrd_adj_delegate_pool);
 248
 249           ip6ip_tunnel_stack (ai, sixrd_ad->sixrd_fib_entry_index);
 250         }
 251     }
 252 }
 253
 254 clib_error_t *
 255 sixrd_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 256 {
 257   /* Always up */
 258   vnet_hw_interface_set_flags (vnm, hw_if_index,
 259                                VNET_HW_INTERFACE_FLAG_LINK_UP);
 260   return /* no error */ 0;
 261 }
 262
 263 /* *INDENT-OFF* */
 264 VNET_HW_INTERFACE_CLASS(sixrd_hw_interface_class) = {
 265     .name = "ip6ip-6rd",
 266     .build_rewrite = sixrd_build_rewrite,
 267     .update_adjacency = sixrd_update_adj,
 268 };
 269
 270 VNET_DEVICE_CLASS(sixrd_device_class) = {
 271     .name = "ip6ip-6rd",
 272     .admin_up_down_function = sixrd_interface_admin_up_down,
 273 #ifdef SOON
 274     .clear counter = 0;
 275 #endif
 276 }
 277 ;
 278 /* *INDENT-ON* */
 279
 280 int
 281 sixrd_add_tunnel (ip6_address_t * ip6_prefix, u8 ip6_prefix_len,
 282                   ip4_address_t * ip4_prefix, u8 ip4_prefix_len,
 283                   ip4_address_t * ip4_src, bool security_check,
 284                   u32 fib_index, u32 * sw_if_index)
 285 {
 286   ipip_main_t *gm = &ipip_main;
 287   ipip_tunnel_t *t;
 288
 289   if (fib_index == ~0)
 290     return VNET_API_ERROR_NO_SUCH_FIB;
 291
 292   if ((ip6_prefix_len + 32 - ip4_prefix_len) > 64)
 293     return VNET_API_ERROR_INVALID_VALUE;
 294
 295   /* Tunnel already configured */
 296   ip46_address_t src = ip46_address_initializer, dst =
 297     ip46_address_initializer;
 298   ip_set (&src, ip4_src, true);
 299   ipip_tunnel_key_t key = {.transport = IPIP_TRANSPORT_IP4,
 300     .fib_index = fib_index,
 301     .src = src,
 302     .dst = dst
 303   };
 304
 305   t = ipip_tunnel_db_find (&key);
 306   if (t)
 307     return VNET_API_ERROR_IF_ALREADY_EXISTS;
 308
 309   /* Get tunnel index */
 310   pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
 311   memset (t, 0, sizeof (*t));
 312   u32 t_idx = t - gm->tunnels;  /* tunnel index (or instance) */
 313
 314   /* Init tunnel struct */
 315   t->mode = IPIP_MODE_6RD;
 316   t->sixrd.ip4_prefix.as_u32 = ip4_prefix->as_u32;
 317   t->sixrd.ip4_prefix_len = ip4_prefix_len;
 318   t->sixrd.ip6_prefix = *ip6_prefix;
 319   t->sixrd.ip6_prefix_len = ip6_prefix_len;
 320   t->tunnel_src = src;
 321   t->sixrd.security_check = security_check;
 322   t->sixrd.shift =
 323     (ip4_prefix_len < 32) ? 64 - ip6_prefix_len - (32 - ip4_prefix_len) : 0;
 324
 325   /* Create interface */
 326   u32 hw_if_index =
 327     vnet_register_interface (vnet_get_main (), sixrd_device_class.index,
 328                              t_idx,
 329                              sixrd_hw_interface_class.index, t_idx);
 330
 331   /* Default the interface to up and enable IPv6 (payload) */
 332   vnet_hw_interface_t *hi =
 333     vnet_get_hw_interface (vnet_get_main (), hw_if_index);
 334   t->hw_if_index = hw_if_index;
 335   t->fib_index = fib_index;
 336   t->sw_if_index = hi->sw_if_index;
 337   t->dev_instance = t_idx;
 338   t->user_instance = t_idx;
 339
 340   vnet_sw_interface_set_mtu (vnet_get_main (), t->sw_if_index, 1480);
 341
 342   ipip_tunnel_db_add (t, &key);
 343
 344   vec_validate_init_empty (gm->tunnel_index_by_sw_if_index, hi->sw_if_index,
 345                            ~0);
 346   gm->tunnel_index_by_sw_if_index[hi->sw_if_index] = t_idx;
 347
 348   vnet_hw_interface_set_flags (vnet_get_main (), hw_if_index,
 349                                VNET_HW_INTERFACE_FLAG_LINK_UP);
 350   vnet_sw_interface_set_flags (vnet_get_main (), hi->sw_if_index,
 351                                VNET_SW_INTERFACE_FLAG_ADMIN_UP);
 352   ip6_sw_interface_enable_disable (hi->sw_if_index, true);
 353
 354   /* Create IPv6 route/adjacency */
 355   fib_prefix_t pfx6 = {
 356     .fp_proto = FIB_PROTOCOL_IP6,
 357     .fp_len = t->sixrd.ip6_prefix_len,
 358     .fp_addr = {
 359                 .ip6 = t->sixrd.ip6_prefix,
 360                 }
 361     ,
 362   };
 363
 364   fib_table_entry_update_one_path (fib_index, &pfx6, FIB_SOURCE_CLI,
 365                                    FIB_ENTRY_FLAG_ATTACHED, DPO_PROTO_IP6,
 366                                    &sixrd_special_nh, hi->sw_if_index, ~0, 1,
 367                                    NULL, FIB_ROUTE_PATH_FLAG_NONE);
 368
 369   *sw_if_index = hi->sw_if_index;
 370
 371   if (!gm->ip4_protocol_registered)
 372     {
 373       vlib_node_t *ipip4_input =
 374         vlib_get_node_by_name (gm->vlib_main, (u8 *) "ipip4-input");
 375       ASSERT (ipip4_input);
 376       ip4_register_protocol (IP_PROTOCOL_IPV6, ipip4_input->index);
 377     }
 378   return 0;
 379 }
 380
 381 /*
 382  * sixrd_del_tunnel
 383  */
 384 int
 385 sixrd_del_tunnel (u32 sw_if_index)
 386 {
 387   ipip_main_t *gm = &ipip_main;
 388   ipip_tunnel_t *t = ipip_tunnel_db_find_by_sw_if_index (sw_if_index);
 389
 390   if (!t)
 391     {
 392       clib_warning ("SIXRD tunnel delete: tunnel does not exist: %d",
 393                     sw_if_index);
 394       return -1;
 395     }
 396
 397   fib_prefix_t pfx6 = {
 398     .fp_proto = FIB_PROTOCOL_IP6,
 399     .fp_len = t->sixrd.ip6_prefix_len,
 400     .fp_addr = {
 401                 .ip6 = t->sixrd.ip6_prefix,
 402                 }
 403     ,
 404   };
 405   fib_table_entry_special_remove (0, &pfx6, FIB_SOURCE_CLI);
 406   vnet_sw_interface_set_flags (vnet_get_main (), t->sw_if_index,
 407                                0 /* down */ );
 408   ip6_sw_interface_enable_disable (t->sw_if_index, false);
 409   gm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0;
 410
 411   vnet_delete_hw_interface (vnet_get_main (), t->hw_if_index);
 412   ipip_tunnel_db_remove (t);
 413   pool_put (gm->tunnels, t);
 414
 415   return 0;
 416 }
 417
 418 static void
 419 sixrd_adj_delegate_adj_deleted (adj_delegate_t * aed)
 420 {
 421   sixrd_adj_delegate_t *sixrd_ad;
 422
 423   sixrd_ad = sixrd_adj_from_base (aed);
 424   fib_entry_child_remove (sixrd_ad->sixrd_fib_entry_index,
 425                           sixrd_ad->sixrd_sibling);
 426   fib_table_entry_delete_index (sixrd_ad->sixrd_fib_entry_index,
 427                                 FIB_SOURCE_RR);
 428   pool_put (sixrd_adj_delegate_pool, sixrd_ad);
 429 }
 430
 431 static u8 *
 432 sixrd_adj_delegate_format (const adj_delegate_t * aed, u8 * s)
 433 {
 434   const sixrd_adj_delegate_t *sixrd_ad;
 435
 436   sixrd_ad = sixrd_adj_from_const_base (aed);
 437   s = format (s, "SIXRD:[fib-entry:%d]", sixrd_ad->sixrd_fib_entry_index);
 438
 439   return (s);
 440 }
 441
 442 static void
 443 sixrd_fib_node_last_lock_gone (fib_node_t * node)
 444 {
 445   /* top of the dependency tree, locks not managed here. */
 446 }
 447
 448 static sixrd_adj_delegate_t *
 449 sixrd_adj_delegate_from_fib_node (fib_node_t * node)
 450 {
 451   return ((sixrd_adj_delegate_t *) (((char *) node) -
 452                                     STRUCT_OFFSET_OF (sixrd_adj_delegate_t,
 453                                                       sixrd_node)));
 454 }
 455
 456 static fib_node_back_walk_rc_t
 457 sixrd_fib_node_back_walk_notify (fib_node_t * node,
 458                                  fib_node_back_walk_ctx_t * ctx)
 459 {
 460   sixrd_adj_delegate_t *sixrd_ad;
 461
 462   sixrd_ad = sixrd_adj_delegate_from_fib_node (node);
 463   ip6ip_tunnel_stack (sixrd_ad->adj_index, sixrd_ad->sixrd_fib_entry_index);
 464
 465   return (FIB_NODE_BACK_WALK_CONTINUE);
 466 }
 467
 468 /**
 469  * Function definition to get a FIB node from its index
 470  */
 471 static fib_node_t *
 472 sixrd_fib_node_get (fib_node_index_t index)
 473 {
 474   sixrd_adj_delegate_t *sixrd_ad;
 475
 476   sixrd_ad = pool_elt_at_index (sixrd_adj_delegate_pool, index);
 477
 478   return (&sixrd_ad->sixrd_node);
 479 }
 480
 481 /**
 482  * VFT registered with the adjacency delegate
 483  */
 484 const static adj_delegate_vft_t sixrd_adj_delegate_vft = {
 485   .adv_adj_deleted = sixrd_adj_delegate_adj_deleted,
 486   .adv_format = sixrd_adj_delegate_format,
 487 };
 488
 489 /**
 490  * VFT registered with the FIB node for the adj delegate
 491  */
 492 const static fib_node_vft_t sixrd_fib_node_vft = {
 493   .fnv_get = sixrd_fib_node_get,
 494   .fnv_last_lock = sixrd_fib_node_last_lock_gone,
 495   .fnv_back_walk = sixrd_fib_node_back_walk_notify,
 496 };
 497
 498 static clib_error_t *
 499 sixrd_init (vlib_main_t * vm)
 500 {
 501   clib_error_t *error = 0;
 502
 503   /* Make sure the IPIP tunnel subsystem is initialised */
 504   error = vlib_call_init_function (vm, ipip_init);
 505
 506   sixrd_adj_delegate_type =
 507     adj_delegate_register_new_type (&sixrd_adj_delegate_vft);
 508   sixrd_fib_node_type = fib_node_register_new_type (&sixrd_fib_node_vft);
 509
 510   return error;
 511 }
 512
 513 VLIB_INIT_FUNCTION (sixrd_init);
 514
 515 /*
 516  * fd.io coding-style-patch-verification: ON
 517  *
 518  * Local Variables:
 519  * eval: (c-set-style "gnu")
 520  * End:
 521  */