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