src/plugins/dhcp/dhcp6_client_common_dp.c

   1 /*
   2  * Copyright (c) 2018 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
  16 #include <vnet/ethernet/ethernet.h>
  17 #include <dhcp/dhcp6_packet.h>
  18 #include <dhcp/dhcp6_client_common_dp.h>
  19 #include <dhcp/dhcp6_ia_na_client_dp.h>
  20 #include <dhcp/dhcp6_pd_client_dp.h>
  21 #include <dhcp/dhcp6_packet.h>
  22 #include <vnet/udp/udp_local.h>
  23 #include <vnet/udp/udp_packet.h>
  24
  25 dhcp6_client_common_main_t dhcp6_client_common_main;
  26 dhcpv6_duid_ll_string_t client_duid;
  27
  28 u32
  29 server_index_get_or_create (u8 * data, u16 len)
  30 {
  31   dhcp6_client_common_main_t *ccm = &dhcp6_client_common_main;
  32   u32 i;
  33   server_id_t *se;
  34   server_id_t new_se;
  35
  36   for (i = 0; i < vec_len (ccm->server_ids); i++)
  37     {
  38       se = &ccm->server_ids[i];
  39       if (se->len == len && 0 == memcmp (se->data, data, len))
  40         return i;
  41     }
  42
  43   new_se.len = len;
  44   new_se.data = 0;
  45   vec_validate (new_se.data, len - 1);
  46   memcpy (new_se.data, data, len);
  47
  48   vec_add1 (ccm->server_ids, new_se);
  49
  50   return vec_len (ccm->server_ids) - 1;
  51 }
  52
  53 static void
  54 generate_client_duid (void)
  55 {
  56   client_duid.duid_type = clib_host_to_net_u16 (DHCPV6_DUID_LL);
  57   client_duid.hardware_type = clib_host_to_net_u16 (1);
  58
  59   vnet_main_t *vnm = vnet_get_main ();
  60   vnet_interface_main_t *im = &vnm->interface_main;
  61   vnet_hw_interface_t *hi;
  62   ethernet_interface_t *eth_if = 0;
  63
  64   /* *INDENT-OFF* */
  65   pool_foreach (hi, im->hw_interfaces)
  66    {
  67     eth_if = ethernet_get_interface (&ethernet_main, hi->hw_if_index);
  68     if (eth_if)
  69       break;
  70   }
  71   /* *INDENT-ON* */
  72
  73   if (eth_if)
  74     clib_memcpy (client_duid.lla, &eth_if->address, 6);
  75   else
  76     {
  77       clib_warning ("Failed to find any Ethernet interface, "
  78                     "setting DHCPv6 DUID link-layer address to random value");
  79       u32 seed = random_default_seed ();
  80       random_u32 (&seed);
  81       client_duid.lla[0] = 0xc2;        /* locally administered unicast */
  82       client_duid.lla[1] = 0x18;
  83       client_duid.lla[2] = 0x44;
  84       client_duid.lla[3] = random_u32 (&seed);
  85       client_duid.lla[4] = random_u32 (&seed);
  86       client_duid.lla[5] = random_u32 (&seed);
  87     }
  88 }
  89
  90 #define foreach_dhcpv6_client \
  91   _(DROP, "error-drop")       \
  92   _(LOOKUP, "ip6-lookup")
  93
  94 typedef enum
  95 {
  96 #define _(sym,str) DHCPV6_CLIENT_NEXT_##sym,
  97   foreach_dhcpv6_client
  98 #undef _
  99     DHCPV6_CLIENT_N_NEXT,
 100 } dhcpv6_client_next_t;
 101
 102 /**
 103  * per-packet trace data
 104  */
 105 typedef struct dhcpv6_client_trace_t_
 106 {
 107 } dhcpv6_client_trace_t;
 108
 109 static u8 *
 110 format_dhcpv6_client_trace (u8 * s, va_list * args)
 111 {
 112   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 113   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 114   //dhcpv6_client_trace_t *t = va_arg (*args, dhcpv6_client_trace_t *);
 115
 116   s = format (s, "nothing");
 117
 118   return s;
 119 }
 120
 121 static uword
 122 dhcpv6_client_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 123                        vlib_frame_t * frame)
 124 {
 125   dhcp6_ia_na_client_main_t *icm = &dhcp6_ia_na_client_main;
 126   dhcp6_pd_client_main_t *pcm = &dhcp6_pd_client_main;
 127
 128   dhcpv6_client_next_t next_index;
 129   u32 n_left_from, *from, *to_next;
 130   next_index = 0;
 131   n_left_from = frame->n_vectors;
 132   from = vlib_frame_vector_args (frame);
 133
 134   while (n_left_from > 0)
 135     {
 136       u32 n_left_to_next;
 137
 138       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 139
 140       while (n_left_from > 0 && n_left_to_next > 0)
 141         {
 142           ip6_header_t *ip0;
 143           u32 options_length;
 144           dhcpv6_header_t *dhcpv60;
 145           dhcpv6_option_t *option;
 146           vlib_buffer_t *b0;
 147           dhcp6_report_common_t report;
 148           dhcp6_address_info_t *addresses = 0;
 149           dhcp6_prefix_info_t *prefixes = 0;
 150           u32 next0 = DHCPV6_CLIENT_NEXT_DROP;
 151           u32 bi0;
 152           u32 xid;
 153           u32 sw_if_index;
 154           u32 iaid;
 155           u8 client_id_present = 0;
 156           u8 discard = 0;
 157           u8 is_pd_packet = 0;
 158
 159           dhcp6_ia_na_client_state_t *ia_na_client_state = NULL;
 160           dhcp6_pd_client_state_t *pd_client_state = NULL;
 161
 162           bi0 = from[0];
 163           to_next[0] = bi0;
 164           from += 1;
 165           to_next += 1;
 166           n_left_from -= 1;
 167           n_left_to_next -= 1;
 168
 169           b0 = vlib_get_buffer (vm, bi0);
 170
 171           dhcpv60 = vlib_buffer_get_current (b0);
 172           ip0 = (void *) (b0->data + vnet_buffer (b0)->l3_hdr_offset);
 173           u32 dhcpv6_ip6_payload_offset =
 174             (u8 *) dhcpv60 - ((u8 *) ip0 + sizeof (*ip0));
 175           options_length =
 176             clib_net_to_host_u16 (ip0->payload_length) -
 177             dhcpv6_ip6_payload_offset - sizeof (*dhcpv60);
 178
 179           clib_memset (&report, 0, sizeof (report));
 180
 181           sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 182           if (sw_if_index >= vec_len (icm->client_state_by_sw_if_index))
 183             ia_na_client_state = 0;
 184           else
 185             ia_na_client_state =
 186               &icm->client_state_by_sw_if_index[sw_if_index];
 187           if (sw_if_index >= vec_len (pcm->client_state_by_sw_if_index))
 188             pd_client_state = 0;
 189           else
 190             pd_client_state = &pcm->client_state_by_sw_if_index[sw_if_index];
 191
 192           xid =
 193             (dhcpv60->xid[0] << 16) + (dhcpv60->xid[1] << 8) +
 194             dhcpv60->xid[2];
 195           if (ia_na_client_state && ia_na_client_state->transaction_id == xid)
 196             is_pd_packet = 0;
 197           else if (pd_client_state && pd_client_state->transaction_id == xid)
 198             is_pd_packet = 1;
 199           else
 200             {
 201               clib_warning
 202                 ("Received DHCPv6 message with wrong Transaction ID");
 203               discard = 1;
 204             }
 205
 206           report.sw_if_index = sw_if_index;
 207           report.msg_type = dhcpv60->msg_type;
 208           report.server_index = ~0;
 209
 210           switch (dhcpv60->msg_type)
 211             {
 212             case DHCPV6_MSG_ADVERTISE:
 213             case DHCPV6_MSG_REPLY:
 214               option = (dhcpv6_option_t *) (dhcpv60 + 1);
 215               while (options_length > 0)
 216                 {
 217                   if (options_length <
 218                       clib_net_to_host_u16 (option->length) +
 219                       sizeof (*option))
 220                     {
 221                       clib_warning
 222                         ("remaining payload length < option length (%d < %d)",
 223                          options_length,
 224                          clib_net_to_host_u16 (option->length) +
 225                          sizeof (*option));
 226                       break;
 227                     }
 228                   u16 oo = clib_net_to_host_u16 (option->option);
 229                   if (oo == DHCPV6_OPTION_IA_NA || oo == DHCPV6_OPTION_IA_PD)
 230                     {
 231                       u8 discard_option = 0;
 232                       dhcpv6_ia_header_t *ia_header = (void *) option;
 233                       iaid = clib_net_to_host_u32 (ia_header->iaid);
 234                       u32 T1 = clib_net_to_host_u32 (ia_header->t1);
 235                       u32 T2 = clib_net_to_host_u32 (ia_header->t2);
 236                       if (iaid != DHCPV6_CLIENT_IAID)
 237                         discard_option = 1;
 238                       if (T1 != 0 && T2 != 0 && T1 > T2)
 239                         discard_option = 1;
 240                       if (!discard_option)
 241                         {
 242                           report.T1 = T1;
 243                           report.T2 = T2;
 244                         }
 245                       dhcpv6_option_t *inner_option =
 246                         (void *) ia_header->data;
 247                       u16 inner_options_length =
 248                         clib_net_to_host_u16 (option->length) -
 249                         (sizeof (*ia_header) - sizeof (dhcpv6_option_t));
 250                       while (inner_options_length > 0)
 251                         {
 252                           u16 inner_oo =
 253                             clib_net_to_host_u16 (inner_option->option);
 254                           if (discard_option)
 255                             ;
 256                           else if (inner_oo == DHCPV6_OPTION_IAADDR)
 257                             {
 258                               dhcpv6_ia_opt_addr_t *iaaddr =
 259                                 (void *) inner_option;
 260                               u32 n_addresses = vec_len (addresses);
 261                               vec_validate (addresses, n_addresses);
 262                               dhcp6_address_info_t *address_info =
 263                                 &addresses[n_addresses];
 264                               address_info->preferred_time =
 265                                 clib_net_to_host_u32 (iaaddr->preferred);
 266                               address_info->valid_time =
 267                                 clib_net_to_host_u32 (iaaddr->valid);
 268                               address_info->address = iaaddr->addr;
 269                             }
 270                           else if (inner_oo == DHCPV6_OPTION_IAPREFIX)
 271                             {
 272                               dhcpv6_ia_opt_pd_t *iaprefix =
 273                                 (void *) inner_option;
 274                               u32 n_prefixes = vec_len (prefixes);
 275                               vec_validate (prefixes, n_prefixes);
 276                               dhcp6_prefix_info_t *prefix_info =
 277                                 &prefixes[n_prefixes];
 278                               prefix_info->preferred_time =
 279                                 clib_net_to_host_u32 (iaprefix->preferred);
 280                               prefix_info->valid_time =
 281                                 clib_net_to_host_u32 (iaprefix->valid);
 282                               prefix_info->prefix_length = iaprefix->prefix;
 283                               prefix_info->prefix = iaprefix->addr;
 284                             }
 285                           else if (inner_oo == DHCPV6_OPTION_STATUS_CODE)
 286                             {
 287                               dhcpv6_status_code_t *sc =
 288                                 (void *) inner_option;
 289                               report.inner_status_code =
 290                                 clib_net_to_host_u16 (sc->status_code);
 291                             }
 292                           inner_options_length -=
 293                             sizeof (*inner_option) +
 294                             clib_net_to_host_u16 (inner_option->length);
 295                           inner_option =
 296                             (void *) ((u8 *) inner_option +
 297                                       sizeof (*inner_option) +
 298                                       clib_net_to_host_u16
 299                                       (inner_option->length));
 300                         }
 301                     }
 302                   else if (oo == DHCPV6_OPTION_CLIENTID)
 303                     {
 304                       if (client_id_present)
 305                         {
 306                           clib_warning
 307                             ("Duplicate Client ID in received DHVPv6 message");
 308                           discard = 1;
 309                         }
 310                       else
 311                         {
 312                           u16 len = clib_net_to_host_u16 (option->length);
 313                           client_id_present = 1;
 314                           if (len != CLIENT_DUID_LENGTH ||
 315                               0 != memcmp (option->data,
 316                                            client_duid.bin_string,
 317                                            CLIENT_DUID_LENGTH))
 318                             {
 319                               clib_warning
 320                                 ("Unrecognized client DUID inside received DHVPv6 message");
 321                               discard = 1;
 322                             }
 323                         }
 324                     }
 325                   else if (oo == DHCPV6_OPTION_SERVERID)
 326                     {
 327                       if (report.server_index != ~0)
 328                         {
 329                           clib_warning
 330                             ("Duplicate Server ID in received DHVPv6 message");
 331                           discard = 1;
 332                         }
 333                       else
 334                         {
 335                           u16 ol = clib_net_to_host_u16 (option->length);
 336                           if (ol - 2 /* 2 byte DUID type code */  > 128)
 337                             {
 338                               clib_warning
 339                                 ("Server DUID (without type code) is longer than 128 octets");
 340                               discard = 1;
 341                             }
 342                           else
 343                             {
 344                               report.server_index =
 345                                 server_index_get_or_create (option->data, ol);
 346                             }
 347                         }
 348                     }
 349                   else if (oo == DHCPV6_OPTION_PREFERENCE)
 350                     {
 351                       report.preference = option->data[0];
 352                     }
 353                   else if (oo == DHCPV6_OPTION_STATUS_CODE)
 354                     {
 355                       dhcpv6_status_code_t *sc = (void *) option;
 356                       report.status_code =
 357                         clib_net_to_host_u16 (sc->status_code);
 358                     }
 359                   options_length -=
 360                     sizeof (*option) + clib_net_to_host_u16 (option->length);
 361                   option =
 362                     (void *) ((u8 *) option + sizeof (*option) +
 363                               clib_net_to_host_u16 (option->length));
 364                 }
 365
 366               if (!client_id_present)
 367                 {
 368                   clib_warning
 369                     ("Missing Client ID in received DHVPv6 message");
 370                   discard = 1;
 371                 }
 372               if (report.server_index == ~0)
 373                 {
 374                   clib_warning
 375                     ("Missing Server ID in received DHVPv6 message");
 376                   discard = 1;
 377                 }
 378
 379               if (!discard)
 380                 {
 381                   if (!is_pd_packet)
 382                     {
 383                       address_report_t r;
 384                       r.body = report;
 385                       r.n_addresses = vec_len (addresses);
 386                       r.addresses = addresses;
 387                       dhcp6_publish_report (&r);
 388                       /* We just gave addresses to another process! */
 389                       addresses = 0;
 390                     }
 391                   else
 392                     {
 393                       prefix_report_t r;
 394                       r.body = report;
 395                       r.n_prefixes = vec_len (prefixes);
 396                       r.prefixes = prefixes;
 397                       dhcp6_pd_publish_report (&r);
 398                       /* We just gave prefixes to another process! */
 399                       prefixes = 0;
 400                     }
 401                 }
 402               vec_free (addresses);
 403               vec_free (prefixes);
 404
 405               break;
 406             default:
 407               break;
 408             }
 409
 410           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 411             {
 412               dhcpv6_client_trace_t *t =
 413                 vlib_add_trace (vm, node, b0, sizeof (*t));
 414             }
 415
 416           /* verify speculative enqueue, maybe switch current next frame */
 417           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 418                                            to_next, n_left_to_next,
 419                                            bi0, next0);
 420         }
 421
 422       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 423     }
 424
 425   return frame->n_vectors;
 426 }
 427
 428 /* *INDENT-OFF* */
 429 VLIB_REGISTER_NODE (dhcpv6_client_node, static) = {
 430     .function = dhcpv6_client_node_fn,
 431     .name = "dhcpv6-client",
 432     .vector_size = sizeof (u32),
 433
 434     .n_errors = 0,
 435
 436     .n_next_nodes = DHCPV6_CLIENT_N_NEXT,
 437     .next_nodes = {
 438   #define _(s,n) [DHCPV6_CLIENT_NEXT_##s] = n,
 439       foreach_dhcpv6_client
 440   #undef _
 441     },
 442
 443     .format_trace = format_dhcpv6_client_trace,
 444 };
 445 /* *INDENT-ON* */
 446
 447 void
 448 dhcp6_clients_enable_disable (u8 enable)
 449 {
 450   vlib_main_t *vm = vlib_get_main ();
 451
 452   if (enable)
 453     {
 454       if (client_duid.duid_type == 0)
 455         generate_client_duid ();
 456       udp_register_dst_port (vm, UDP_DST_PORT_dhcpv6_to_client,
 457                              dhcpv6_client_node.index, 0 /* is_ip6 */ );
 458     }
 459   else
 460     udp_unregister_dst_port (vm, UDP_DST_PORT_dhcpv6_to_client,
 461                              0 /* is_ip6 */ );
 462 }
 463
 464 /*
 465  * fd.io coding-style-patch-verification: ON
 466  *
 467  * Local Variables:
 468  * eval: (c-set-style "gnu")
 469  * End:
 470  */