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