src/vnet/ip6-nd/ip6_nd.c

   1 /*
   2  * ip/ip6_neighbor.c: IP6 neighbor handling
   3  *
   4  * Copyright (c) 2010 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 #include <vnet/ip6-nd/ip6_nd.h>
  19
  20 #include <vnet/ip-neighbor/ip_neighbor.h>
  21 #include <vnet/ip-neighbor/ip_neighbor_dp.h>
  22
  23 #include <vnet/fib/ip6_fib.h>
  24 #include <vnet/ip/ip6_link.h>
  25 #include <vnet/ip/ip6_ll_table.h>
  26
  27 /**
  28  * @file
  29  * @brief IPv6 Neighbor Adjacency and Neighbor Discovery.
  30  *
  31  * The files contains the API and CLI code for managing IPv6 neighbor
  32  * adjacency tables and neighbor discovery logic.
  33  */
  34
  35 #define DEF_MAX_RADV_INTERVAL 200
  36 #define DEF_MIN_RADV_INTERVAL .75 * DEF_MAX_RADV_INTERVAL
  37
  38 typedef struct ip6_nd_t_
  39 {
  40   /* local information */
  41   u32 sw_if_index;
  42
  43   /* stats */
  44   u32 n_solicitations_rcvd;
  45   u32 n_solicitations_dropped;
  46 } ip6_nd_t;
  47
  48 static ip6_link_delegate_id_t ip6_nd_delegate_id;
  49 static ip6_nd_t *ip6_nd_pool;
  50
  51
  52 typedef enum
  53 {
  54   ICMP6_NEIGHBOR_SOLICITATION_NEXT_DROP,
  55   ICMP6_NEIGHBOR_SOLICITATION_NEXT_REPLY,
  56   ICMP6_NEIGHBOR_SOLICITATION_N_NEXT,
  57 } icmp6_neighbor_solicitation_or_advertisement_next_t;
  58
  59 static_always_inline uword
  60 icmp6_neighbor_solicitation_or_advertisement (vlib_main_t * vm,
  61                                               vlib_node_runtime_t * node,
  62                                               vlib_frame_t * frame,
  63                                               uword is_solicitation)
  64 {
  65   vnet_main_t *vnm = vnet_get_main ();
  66   ip6_main_t *im = &ip6_main;
  67   uword n_packets = frame->n_vectors;
  68   u32 *from, *to_next;
  69   u32 n_left_from, n_left_to_next, next_index, n_advertisements_sent;
  70   icmp6_neighbor_discovery_option_type_t option_type;
  71   vlib_node_runtime_t *error_node =
  72     vlib_node_get_runtime (vm, ip6_icmp_input_node.index);
  73   int bogus_length;
  74
  75   from = vlib_frame_vector_args (frame);
  76   n_left_from = n_packets;
  77   next_index = node->cached_next_index;
  78
  79   if (node->flags & VLIB_NODE_FLAG_TRACE)
  80     vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
  81                                    /* stride */ 1,
  82                                    sizeof (icmp6_input_trace_t));
  83
  84   option_type =
  85     (is_solicitation
  86      ? ICMP6_NEIGHBOR_DISCOVERY_OPTION_source_link_layer_address
  87      : ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address);
  88   n_advertisements_sent = 0;
  89
  90   while (n_left_from > 0)
  91     {
  92       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  93
  94       while (n_left_from > 0 && n_left_to_next > 0)
  95         {
  96           vlib_buffer_t *p0;
  97           ip6_header_t *ip0;
  98           icmp6_neighbor_solicitation_or_advertisement_header_t *h0;
  99           icmp6_neighbor_discovery_ethernet_link_layer_address_option_t *o0;
 100           u32 bi0, options_len0, sw_if_index0, next0, error0;
 101           u32 ip6_sadd_link_local, ip6_sadd_unspecified;
 102           int is_rewrite0;
 103           u32 ni0;
 104
 105           bi0 = to_next[0] = from[0];
 106
 107           from += 1;
 108           to_next += 1;
 109           n_left_from -= 1;
 110           n_left_to_next -= 1;
 111
 112           p0 = vlib_get_buffer (vm, bi0);
 113           ip0 = vlib_buffer_get_current (p0);
 114           h0 = ip6_next_header (ip0);
 115           options_len0 =
 116             clib_net_to_host_u16 (ip0->payload_length) - sizeof (h0[0]);
 117
 118           error0 = ICMP6_ERROR_NONE;
 119           sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 120           ip6_sadd_link_local =
 121             ip6_address_is_link_local_unicast (&ip0->src_address);
 122           ip6_sadd_unspecified =
 123             ip6_address_is_unspecified (&ip0->src_address);
 124
 125           /* Check that source address is unspecified, link-local or else on-link. */
 126           if (!ip6_sadd_unspecified && !ip6_sadd_link_local)
 127             {
 128               u32 src_adj_index0 = ip6_src_lookup_for_packet (im, p0, ip0);
 129
 130               if (ADJ_INDEX_INVALID != src_adj_index0)
 131                 {
 132                   ip_adjacency_t *adj0 = adj_get (src_adj_index0);
 133
 134                   /* Allow all realistic-looking rewrite adjacencies to pass */
 135                   ni0 = adj0->lookup_next_index;
 136                   is_rewrite0 = (ni0 >= IP_LOOKUP_NEXT_ARP) &&
 137                     (ni0 < IP6_LOOKUP_N_NEXT);
 138
 139                   error0 = ((adj0->rewrite_header.sw_if_index != sw_if_index0
 140                              || !is_rewrite0)
 141                             ?
 142                             ICMP6_ERROR_NEIGHBOR_SOLICITATION_SOURCE_NOT_ON_LINK
 143                             : error0);
 144                 }
 145               else
 146                 {
 147                   error0 =
 148                     ICMP6_ERROR_NEIGHBOR_SOLICITATION_SOURCE_NOT_ON_LINK;
 149                 }
 150             }
 151
 152           o0 = (void *) (h0 + 1);
 153           o0 = ((options_len0 == 8 && o0->header.type == option_type
 154                  && o0->header.n_data_u64s == 1) ? o0 : 0);
 155
 156           /* If src address unspecified or link local, donot learn neighbor MAC */
 157           if (PREDICT_TRUE (error0 == ICMP6_ERROR_NONE && o0 != 0 &&
 158                             !ip6_sadd_unspecified))
 159             {
 160               ip_neighbor_learn_t learn = {
 161                 .sw_if_index = sw_if_index0,
 162                 .type = IP46_TYPE_IP6,
 163                 .ip.ip6 = (is_solicitation ?
 164                            ip0->src_address : h0->target_address),
 165               };
 166               memcpy (&learn.mac, o0->ethernet_address, sizeof (learn.mac));
 167               ip_neighbor_learn_dp (&learn);
 168             }
 169
 170           if (is_solicitation && error0 == ICMP6_ERROR_NONE)
 171             {
 172               /* Check that target address is local to this router. */
 173               fib_node_index_t fei;
 174               u32 fib_index;
 175
 176               fib_index =
 177                 ip6_fib_table_get_index_for_sw_if_index (sw_if_index0);
 178
 179               if (~0 == fib_index)
 180                 {
 181                   error0 = ICMP6_ERROR_NEIGHBOR_SOLICITATION_SOURCE_UNKNOWN;
 182                 }
 183               else
 184                 {
 185                   if (ip6_address_is_link_local_unicast (&h0->target_address))
 186                     {
 187                       fei = ip6_fib_table_lookup_exact_match
 188                         (ip6_ll_fib_get (sw_if_index0),
 189                          &h0->target_address, 128);
 190                     }
 191                   else
 192                     {
 193                       fei = ip6_fib_table_lookup_exact_match (fib_index,
 194                                                               &h0->target_address,
 195                                                               128);
 196                     }
 197
 198                   if (FIB_NODE_INDEX_INVALID == fei)
 199                     {
 200                       /* The target address is not in the FIB */
 201                       error0 =
 202                         ICMP6_ERROR_NEIGHBOR_SOLICITATION_SOURCE_UNKNOWN;
 203                     }
 204                   else
 205                     {
 206                       if (FIB_ENTRY_FLAG_LOCAL &
 207                           fib_entry_get_flags_for_source (fei,
 208                                                           FIB_SOURCE_INTERFACE))
 209                         {
 210                           /* It's an address that belongs to one of our interfaces
 211                            * that's good. */
 212                         }
 213                       else
 214                         if (fib_entry_is_sourced
 215                             (fei, FIB_SOURCE_IP6_ND_PROXY) ||
 216                             fib_entry_is_sourced (fei, FIB_SOURCE_IP6_ND))
 217                         {
 218                           /* The address was added by IPv6 Proxy ND config.
 219                            * We should only respond to these if the NS arrived on
 220                            * the link that has a matching covering prefix */
 221                         }
 222                       else
 223                         {
 224                           error0 =
 225                             ICMP6_ERROR_NEIGHBOR_SOLICITATION_SOURCE_UNKNOWN;
 226                         }
 227                     }
 228                 }
 229             }
 230
 231           if (is_solicitation)
 232             next0 = (error0 != ICMP6_ERROR_NONE
 233                      ? ICMP6_NEIGHBOR_SOLICITATION_NEXT_DROP
 234                      : ICMP6_NEIGHBOR_SOLICITATION_NEXT_REPLY);
 235           else
 236             {
 237               next0 = 0;
 238               error0 = error0 == ICMP6_ERROR_NONE ?
 239                 ICMP6_ERROR_NEIGHBOR_ADVERTISEMENTS_RX : error0;
 240             }
 241
 242           if (is_solicitation && error0 == ICMP6_ERROR_NONE)
 243             {
 244               vnet_sw_interface_t *sw_if0;
 245               ethernet_interface_t *eth_if0;
 246               ethernet_header_t *eth0;
 247
 248               /* dst address is either source address or the all-nodes mcast addr */
 249               if (!ip6_sadd_unspecified)
 250                 ip0->dst_address = ip0->src_address;
 251               else
 252                 ip6_set_reserved_multicast_address (&ip0->dst_address,
 253                                                     IP6_MULTICAST_SCOPE_link_local,
 254                                                     IP6_MULTICAST_GROUP_ID_all_hosts);
 255
 256               ip0->src_address = h0->target_address;
 257               ip0->hop_limit = 255;
 258               h0->icmp.type = ICMP6_neighbor_advertisement;
 259
 260               sw_if0 = vnet_get_sup_sw_interface (vnm, sw_if_index0);
 261               ASSERT (sw_if0->type == VNET_SW_INTERFACE_TYPE_HARDWARE);
 262               eth_if0 =
 263                 ethernet_get_interface (&ethernet_main, sw_if0->hw_if_index);
 264               if (eth_if0 && o0)
 265                 {
 266                   clib_memcpy (o0->ethernet_address, eth_if0->address, 6);
 267                   o0->header.type =
 268                     ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
 269                 }
 270
 271               h0->advertisement_flags = clib_host_to_net_u32
 272                 (ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED
 273                  | ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
 274
 275               h0->icmp.checksum = 0;
 276               h0->icmp.checksum =
 277                 ip6_tcp_udp_icmp_compute_checksum (vm, p0, ip0,
 278                                                    &bogus_length);
 279               ASSERT (bogus_length == 0);
 280
 281               /* Reuse current MAC header, copy SMAC to DMAC and
 282                * interface MAC to SMAC */
 283               vlib_buffer_advance (p0, -ethernet_buffer_header_size (p0));
 284               eth0 = vlib_buffer_get_current (p0);
 285               clib_memcpy (eth0->dst_address, eth0->src_address, 6);
 286               if (eth_if0)
 287                 clib_memcpy (eth0->src_address, eth_if0->address, 6);
 288
 289               /* Setup input and output sw_if_index for packet */
 290               ASSERT (vnet_buffer (p0)->sw_if_index[VLIB_RX] == sw_if_index0);
 291               vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
 292               vnet_buffer (p0)->sw_if_index[VLIB_RX] =
 293                 vnet_main.local_interface_sw_if_index;
 294
 295               n_advertisements_sent++;
 296             }
 297
 298           p0->error = error_node->errors[error0];
 299
 300           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 301                                            to_next, n_left_to_next,
 302                                            bi0, next0);
 303         }
 304
 305       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 306     }
 307
 308   /* Account for advertisements sent. */
 309   vlib_error_count (vm, error_node->node_index,
 310                     ICMP6_ERROR_NEIGHBOR_ADVERTISEMENTS_TX,
 311                     n_advertisements_sent);
 312
 313   return frame->n_vectors;
 314 }
 315
 316 static const ethernet_interface_t *
 317 ip6_nd_get_eth_itf (u32 sw_if_index)
 318 {
 319   const vnet_sw_interface_t *sw;
 320
 321   /* lookup radv container  - ethernet interfaces only */
 322   sw = vnet_get_sup_sw_interface (vnet_get_main (), sw_if_index);
 323   if (sw->type == VNET_SW_INTERFACE_TYPE_HARDWARE)
 324     return (ethernet_get_interface (&ethernet_main, sw->hw_if_index));
 325
 326   return (NULL);
 327 }
 328
 329 /**
 330  * @brief called when IP6 is enabled on a link.
 331  * create and initialize router advertisement parameters with default
 332  * values for this intfc
 333  */
 334 static void
 335 ip6_nd_link_enable (u32 sw_if_index)
 336 {
 337   const ethernet_interface_t *eth;
 338   ip6_nd_t *ind;
 339
 340   eth = ip6_nd_get_eth_itf (sw_if_index);
 341
 342   if (NULL == eth)
 343     return;
 344
 345   ASSERT (INDEX_INVALID == ip6_link_delegate_get (sw_if_index,
 346                                                   ip6_nd_delegate_id));
 347
 348   pool_get_zero (ip6_nd_pool, ind);
 349
 350   ind->sw_if_index = sw_if_index;
 351
 352   ip6_link_delegate_update (sw_if_index, ip6_nd_delegate_id,
 353                             ind - ip6_nd_pool);
 354 }
 355
 356 static void
 357 ip6_nd_delegate_disable (index_t indi)
 358 {
 359   ip6_nd_t *ind;
 360
 361   ind = pool_elt_at_index (ip6_nd_pool, indi);
 362
 363   pool_put (ip6_nd_pool, ind);
 364 }
 365
 366 static uword
 367 icmp6_neighbor_solicitation (vlib_main_t * vm,
 368                              vlib_node_runtime_t * node, vlib_frame_t * frame)
 369 {
 370   return icmp6_neighbor_solicitation_or_advertisement (vm, node, frame,
 371                                                        /* is_solicitation */
 372                                                        1);
 373 }
 374
 375 static uword
 376 icmp6_neighbor_advertisement (vlib_main_t * vm,
 377                               vlib_node_runtime_t * node,
 378                               vlib_frame_t * frame)
 379 {
 380   return icmp6_neighbor_solicitation_or_advertisement (vm, node, frame,
 381                                                        /* is_solicitation */
 382                                                        0);
 383 }
 384
 385 /* *INDENT-OFF* */
 386 VLIB_REGISTER_NODE (ip6_icmp_neighbor_solicitation_node,static) =
 387 {
 388   .function = icmp6_neighbor_solicitation,
 389   .name = "icmp6-neighbor-solicitation",
 390
 391   .vector_size = sizeof (u32),
 392
 393   .format_trace = format_icmp6_input_trace,
 394
 395   .n_next_nodes = ICMP6_NEIGHBOR_SOLICITATION_N_NEXT,
 396   .next_nodes = {
 397     [ICMP6_NEIGHBOR_SOLICITATION_NEXT_DROP] = "ip6-drop",
 398     [ICMP6_NEIGHBOR_SOLICITATION_NEXT_REPLY] = "interface-output",
 399   },
 400 };
 401
 402 VLIB_REGISTER_NODE (ip6_icmp_neighbor_advertisement_node,static) =
 403 {
 404   .function = icmp6_neighbor_advertisement,
 405   .name = "icmp6-neighbor-advertisement",
 406
 407   .vector_size = sizeof (u32),
 408
 409   .format_trace = format_icmp6_input_trace,
 410
 411   .n_next_nodes = 1,
 412   .next_nodes = {
 413     [0] = "ip6-drop",
 414   },
 415 };
 416 /* *INDENT-ON* */
 417
 418 static u8 *
 419 format_ip6_nd (u8 * s, va_list * args)
 420 {
 421   CLIB_UNUSED (index_t indi) = va_arg (*args, index_t);
 422   u32 indent = va_arg (*args, u32);
 423
 424   s = format (s, "%UNeighbor Discovery: enabled\n",
 425               format_white_space, indent);
 426
 427   s = format (s, "%UICMP redirects are disabled\n",
 428               format_white_space, indent + 2);
 429   s = format (s, "%UICMP unreachables are not sent\n",
 430               format_white_space, indent + 2);
 431   s = format (s, "%UND DAD is disabled\n", format_white_space, indent + 2);
 432   //s = format (s, "%UND reachable time is %d milliseconds\n",);
 433
 434   return (s);
 435 }
 436
 437 /**
 438  * VFT to act as an implementation of a neighbour protocol
 439  */
 440 const static ip_neighbor_vft_t ip6_nd_impl_vft = {
 441   .inv_proxy6_add = ip6_nd_proxy_add,
 442   .inv_proxy6_del = ip6_nd_proxy_del,
 443 };
 444
 445 /**
 446  * VFT for registering as a delegate to an IP6 link
 447  */
 448 const static ip6_link_delegate_vft_t ip6_nd_delegate_vft = {
 449   .ildv_disable = ip6_nd_delegate_disable,
 450   .ildv_enable = ip6_nd_link_enable,
 451   .ildv_format = format_ip6_nd,
 452 };
 453
 454 static clib_error_t *
 455 ip6_nd_init (vlib_main_t * vm)
 456 {
 457   icmp6_register_type (vm, ICMP6_neighbor_solicitation,
 458                        ip6_icmp_neighbor_solicitation_node.index);
 459   icmp6_register_type (vm, ICMP6_neighbor_advertisement,
 460                        ip6_icmp_neighbor_advertisement_node.index);
 461
 462   ip_neighbor_register (IP46_TYPE_IP6, &ip6_nd_impl_vft);
 463
 464   ip6_nd_delegate_id = ip6_link_delegate_register (&ip6_nd_delegate_vft);
 465
 466   return 0;
 467 }
 468
 469 /* *INDENT-OFF* */
 470 VLIB_INIT_FUNCTION (ip6_nd_init) =
 471 {
 472   .runs_after = VLIB_INITS("icmp6_init"),
 473 };
 474 /* *INDENT-ON* */
 475
 476 /*
 477  * fd.io coding-style-patch-verification: ON
 478  *
 479  * Local Variables:
 480  * eval: (c-set-style "gnu")
 481  * End:
 482  */