src/plugins/dhcp/dhcp4_proxy_node.c

   1 /*
   2  * proxy_node.c: dhcp proxy node processing
   3  *
   4  * Copyright (c) 2013 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 <vlib/vlib.h>
  19 #include <dhcp/dhcp_proxy.h>
  20 #include <dhcp/client.h>
  21 #include <vnet/fib/ip4_fib.h>
  22
  23 static char *dhcp_proxy_error_strings[] = {
  24 #define dhcp_proxy_error(n,s) s,
  25 #include <dhcp/dhcp4_proxy_error.def>
  26 #undef dhcp_proxy_error
  27 };
  28
  29 #define foreach_dhcp_proxy_to_server_input_next \
  30   _ (DROP, "error-drop")                        \
  31   _ (LOOKUP, "ip4-lookup")                      \
  32   _ (SEND_TO_CLIENT, "dhcp-proxy-to-client")
  33
  34 typedef enum
  35 {
  36 #define _(s,n) DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s,
  37   foreach_dhcp_proxy_to_server_input_next
  38 #undef _
  39     DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
  40 } dhcp_proxy_to_server_input_next_t;
  41
  42 typedef struct
  43 {
  44   /* 0 => to server, 1 => to client */
  45   int which;
  46   ip4_address_t trace_ip4_address;
  47   u32 error;
  48   u32 sw_if_index;
  49   u32 original_sw_if_index;
  50
  51   /* enough space for the DHCP header plus some options */
  52   u8 packet_data[2 * sizeof (dhcp_header_t)];
  53 }
  54 dhcp_proxy_trace_t;
  55
  56 #define VPP_DHCP_OPTION82_SUB1_SIZE   6
  57 #define VPP_DHCP_OPTION82_SUB5_SIZE   6
  58 #define VPP_DHCP_OPTION82_VSS_SIZE    12
  59 #define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
  60                                 VPP_DHCP_OPTION82_SUB5_SIZE + \
  61                                 VPP_DHCP_OPTION82_VSS_SIZE +3)
  62
  63 static vlib_node_registration_t dhcp_proxy_to_server_node;
  64 static vlib_node_registration_t dhcp_proxy_to_client_node;
  65
  66 static u8 *
  67 format_dhcp_proxy_trace (u8 * s, va_list * args)
  68 {
  69   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  70   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  71   dhcp_proxy_trace_t *t = va_arg (*args, dhcp_proxy_trace_t *);
  72
  73   if (t->which == 0)
  74     s = format (s, "DHCP proxy: sent to server %U\n",
  75                 format_ip4_address, &t->trace_ip4_address, t->error);
  76   else
  77     s = format (s, "DHCP proxy: broadcast to client from %U\n",
  78                 format_ip4_address, &t->trace_ip4_address);
  79
  80   if (t->error != (u32) ~ 0)
  81     s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
  82
  83   s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
  84               t->original_sw_if_index, t->sw_if_index);
  85   s = format (s, "  %U",
  86               format_dhcp_header, t->packet_data, sizeof (t->packet_data));
  87
  88   return s;
  89 }
  90
  91 static u8 *
  92 format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
  93 {
  94   dhcp_header_t *h = va_arg (*args, dhcp_header_t *);
  95   u32 max_header_bytes = va_arg (*args, u32);
  96   u32 header_bytes;
  97
  98   header_bytes = sizeof (h[0]);
  99   if (max_header_bytes != 0 && header_bytes > max_header_bytes)
 100     return format (s, "dhcp header truncated");
 101
 102   s = format (s, "DHCP Proxy");
 103
 104   return s;
 105 }
 106
 107 static uword
 108 dhcp_proxy_to_server_input (vlib_main_t * vm,
 109                             vlib_node_runtime_t * node,
 110                             vlib_frame_t * from_frame)
 111 {
 112   u32 n_left_from, next_index, *from, *to_next;
 113   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 114   from = vlib_frame_vector_args (from_frame);
 115   n_left_from = from_frame->n_vectors;
 116   u32 pkts_to_server = 0, pkts_to_client = 0, pkts_no_server = 0;
 117   u32 pkts_no_interface_address = 0;
 118   u32 pkts_too_big = 0;
 119   ip4_main_t *im = &ip4_main;
 120
 121   next_index = node->cached_next_index;
 122
 123   while (n_left_from > 0)
 124     {
 125       u32 n_left_to_next;
 126
 127       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 128
 129       while (n_left_from > 0 && n_left_to_next > 0)
 130         {
 131           u32 bi0;
 132           vlib_buffer_t *b0;
 133           udp_header_t *u0;
 134           dhcp_header_t *h0;
 135           ip4_header_t *ip0;
 136           u32 next0;
 137           u32 old0, new0;
 138           ip_csum_t sum0;
 139           u32 error0 = (u32) ~ 0;
 140           u32 sw_if_index = 0;
 141           u32 original_sw_if_index = 0;
 142           u32 fib_index;
 143           dhcp_proxy_t *proxy;
 144           dhcp_server_t *server;
 145           u32 rx_sw_if_index;
 146           dhcp_option_t *o, *end;
 147           u32 len = 0;
 148           u8 is_discover = 0;
 149           int space_left;
 150
 151           bi0 = from[0];
 152           from += 1;
 153           n_left_from -= 1;
 154
 155           b0 = vlib_get_buffer (vm, bi0);
 156
 157           h0 = vlib_buffer_get_current (b0);
 158
 159           /*
 160            * udp_local hands us the DHCP header, need udp hdr,
 161            * ip hdr to relay to server
 162            */
 163           vlib_buffer_advance (b0, -(sizeof (*u0)));
 164           u0 = vlib_buffer_get_current (b0);
 165
 166           /* This blows. Return traffic has src_port = 67, dst_port = 67 */
 167           if (u0->src_port ==
 168               clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_server))
 169             {
 170               vlib_buffer_advance (b0, sizeof (*u0));
 171               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
 172               error0 = 0;
 173               pkts_to_client++;
 174               goto do_enqueue;
 175             }
 176
 177           rx_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 178           fib_index = im->fib_index_by_sw_if_index[rx_sw_if_index];
 179           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 180
 181           if (PREDICT_FALSE (NULL == proxy))
 182             {
 183               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 184               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 185               pkts_no_server++;
 186               goto do_trace;
 187             }
 188
 189           if (!vlib_buffer_chain_linearize (vm, b0))
 190             {
 191               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 192               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 193               pkts_too_big++;
 194               goto do_trace;
 195             }
 196           space_left = vlib_buffer_space_left_at_end (vm, b0);
 197           /* cant parse chains...
 198            * and we need some space for option 82*/
 199           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
 200               space_left < VPP_DHCP_OPTION82_SIZE)
 201             {
 202               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 203               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 204               pkts_too_big++;
 205               goto do_trace;
 206             }
 207
 208           server = &proxy->dhcp_servers[0];
 209           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 210           ip0 = vlib_buffer_get_current (b0);
 211
 212           /* disable UDP checksum */
 213           u0->checksum = 0;
 214           sum0 = ip0->checksum;
 215           old0 = ip0->dst_address.as_u32;
 216           new0 = server->dhcp_server.ip4.as_u32;
 217           ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 218           sum0 = ip_csum_update (sum0, old0, new0,
 219                                  ip4_header_t /* structure */ ,
 220                                  dst_address /* changed member */ );
 221           ip0->checksum = ip_csum_fold (sum0);
 222
 223           sum0 = ip0->checksum;
 224           old0 = ip0->src_address.as_u32;
 225           new0 = proxy->dhcp_src_address.ip4.as_u32;
 226           ip0->src_address.as_u32 = new0;
 227           sum0 = ip_csum_update (sum0, old0, new0,
 228                                  ip4_header_t /* structure */ ,
 229                                  src_address /* changed member */ );
 230           ip0->checksum = ip_csum_fold (sum0);
 231
 232           /* Send to DHCP server via the configured FIB */
 233           vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
 234
 235           h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
 236           pkts_to_server++;
 237
 238           o = h0->options;
 239           end = (void *) vlib_buffer_get_tail (b0);
 240
 241           /* TLVs are not performance-friendly... */
 242           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 243             {
 244               if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
 245                 {
 246                   if (DHCP_PACKET_DISCOVER == o->data[0])
 247                     {
 248                       is_discover = 1;
 249                     }
 250                 }
 251               o = (dhcp_option_t *) (o->data + o->length);
 252             }
 253
 254           if (o->option == DHCP_PACKET_OPTION_END && o <= end)
 255             {
 256               vnet_main_t *vnm = vnet_get_main ();
 257               u16 old_l0, new_l0;
 258               ip4_address_t _ia0, *ia0 = &_ia0;
 259               dhcp_vss_t *vss;
 260               vnet_sw_interface_t *swif;
 261
 262               original_sw_if_index = sw_if_index =
 263                 vnet_buffer (b0)->sw_if_index[VLIB_RX];
 264               swif = vnet_get_sw_interface (vnm, sw_if_index);
 265               if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 266                 sw_if_index = swif->unnumbered_sw_if_index;
 267
 268               /*
 269                * Get the first ip4 address on the [client-side]
 270                * RX interface, if not unnumbered. otherwise use
 271                * the loopback interface's ip address.
 272                */
 273               ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 274
 275               if (ia0 == 0)
 276                 {
 277                   error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 278                   next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 279                   pkts_no_interface_address++;
 280                   goto do_trace;
 281                 }
 282
 283               /* Add option 82 */
 284               o->option = 82;   /* option 82 */
 285               o->length = 12;   /* 12 octets to follow */
 286               o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
 287               o->data[1] = 4;   /* length of suboption */
 288               u32 *o_ifid = (u32 *) & o->data[2];
 289               *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
 290               o->data[6] = 5;   /* suboption 5 (client RX intfc address) */
 291               o->data[7] = 4;   /* length 4 */
 292               u32 *o_addr = (u32 *) & o->data[8];
 293               *o_addr = ia0->as_u32;
 294               o->data[12] = DHCP_PACKET_OPTION_END;
 295
 296               vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
 297               if (vss)
 298                 {
 299                   u32 id_len;   /* length of VPN ID */
 300
 301                   if (vss->vss_type == VSS_TYPE_VPN_ID)
 302                     {
 303                       id_len = sizeof (vss->vpn_id);    /* vpn_id is 7 bytes */
 304                       memcpy (&o->data[15], vss->vpn_id, id_len);
 305                     }
 306                   else if (vss->vss_type == VSS_TYPE_ASCII)
 307                     {
 308                       id_len = vec_len (vss->vpn_ascii_id);
 309                       memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
 310                     }
 311                   else          /* must be VSS_TYPE_DEFAULT, no VPN ID */
 312                     id_len = 0;
 313
 314                   o->data[12] = 151;    /* vss suboption */
 315                   o->data[13] = id_len + 1;     /* length: vss_type + id_len */
 316                   o->data[14] = vss->vss_type;  /* vss option type */
 317                   o->data[15 + id_len] = 152;   /* vss control suboption */
 318                   o->data[16 + id_len] = 0;     /* length */
 319                   o->data[17 + id_len] = DHCP_PACKET_OPTION_END;        /* "end-of-options" (0xFF) */
 320                   /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
 321                   o->length += id_len + 5;
 322                 }
 323
 324               len = o->length + 3;
 325               b0->current_length += len;
 326               /* Fix IP header length and checksum */
 327               old_l0 = ip0->length;
 328               new_l0 = clib_net_to_host_u16 (old_l0);
 329               new_l0 += len;
 330               new_l0 = clib_host_to_net_u16 (new_l0);
 331               ip0->length = new_l0;
 332               sum0 = ip0->checksum;
 333               sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
 334                                      length /* changed member */ );
 335               ip0->checksum = ip_csum_fold (sum0);
 336
 337               /* Fix UDP length */
 338               new_l0 = clib_net_to_host_u16 (u0->length);
 339               new_l0 += len;
 340               u0->length = clib_host_to_net_u16 (new_l0);
 341             }
 342           else
 343             {
 344               vlib_node_increment_counter
 345                 (vm, dhcp_proxy_to_server_node.index,
 346                  DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
 347             }
 348
 349           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 350
 351           /*
 352            * If we have multiple servers configured and this is the
 353            * client's discover message, then send copies to each of
 354            * those servers
 355            */
 356           if (is_discover && vec_len (proxy->dhcp_servers) > 1)
 357             {
 358               u32 ii;
 359
 360               for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
 361                 {
 362                   vlib_buffer_t *c0;
 363                   u32 ci0;
 364
 365                   c0 = vlib_buffer_copy (vm, b0);
 366                   if (c0 == NULL)
 367                     {
 368                       vlib_node_increment_counter
 369                         (vm, dhcp_proxy_to_server_node.index,
 370                          DHCP_PROXY_ERROR_ALLOC_FAIL, 1);
 371                       continue;
 372                     }
 373                   ci0 = vlib_get_buffer_index (vm, c0);
 374                   server = &proxy->dhcp_servers[ii];
 375
 376                   ip0 = vlib_buffer_get_current (c0);
 377
 378                   sum0 = ip0->checksum;
 379                   old0 = ip0->dst_address.as_u32;
 380                   new0 = server->dhcp_server.ip4.as_u32;
 381                   ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 382                   sum0 = ip_csum_update (sum0, old0, new0,
 383                                          ip4_header_t /* structure */ ,
 384                                          dst_address /* changed member */ );
 385                   ip0->checksum = ip_csum_fold (sum0);
 386
 387                   to_next[0] = ci0;
 388                   to_next += 1;
 389                   n_left_to_next -= 1;
 390
 391                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 392                                                    to_next, n_left_to_next,
 393                                                    ci0, next0);
 394
 395                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 396                     {
 397                       dhcp_proxy_trace_t *tr;
 398
 399                       tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
 400                       tr->which = 0;    /* to server */
 401                       tr->error = error0;
 402                       tr->original_sw_if_index = original_sw_if_index;
 403                       tr->sw_if_index = sw_if_index;
 404                       if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 405                         tr->trace_ip4_address.as_u32 =
 406                           server->dhcp_server.ip4.as_u32;
 407
 408                       clib_memcpy_fast (tr->packet_data, h0,
 409                                         sizeof (tr->packet_data));
 410
 411                     }
 412
 413                   if (PREDICT_FALSE (0 == n_left_to_next))
 414                     {
 415                       vlib_put_next_frame (vm, node, next_index,
 416                                            n_left_to_next);
 417                       vlib_get_next_frame (vm, node, next_index,
 418                                            to_next, n_left_to_next);
 419                     }
 420                 }
 421             }
 422         do_trace:
 423           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 424             {
 425               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 426                                                        b0, sizeof (*tr));
 427               tr->which = 0;    /* to server */
 428               tr->error = error0;
 429               tr->original_sw_if_index = original_sw_if_index;
 430               tr->sw_if_index = sw_if_index;
 431               if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 432                 tr->trace_ip4_address.as_u32 =
 433                   proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
 434               clib_memcpy_fast (tr->packet_data, h0,
 435                                 sizeof (tr->packet_data));
 436             }
 437
 438         do_enqueue:
 439           to_next[0] = bi0;
 440           to_next += 1;
 441           n_left_to_next -= 1;
 442
 443           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 444                                            to_next, n_left_to_next,
 445                                            bi0, next0);
 446         }
 447
 448       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 449     }
 450   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 451                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 452                                pkts_to_client);
 453   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 454                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 455                                pkts_to_server);
 456   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 457                                DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
 458   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 459                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 460                                pkts_no_interface_address);
 461   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 462                                DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
 463   return from_frame->n_vectors;
 464 }
 465
 466 /* *INDENT-OFF* */
 467 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
 468   .function = dhcp_proxy_to_server_input,
 469   .name = "dhcp-proxy-to-server",
 470   /* Takes a vector of packets. */
 471   .vector_size = sizeof (u32),
 472
 473   .n_errors = DHCP_PROXY_N_ERROR,
 474   .error_strings = dhcp_proxy_error_strings,
 475
 476   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 477   .next_nodes = {
 478 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 479     foreach_dhcp_proxy_to_server_input_next
 480 #undef _
 481   },
 482
 483   .format_buffer = format_dhcp_proxy_header_with_length,
 484   .format_trace = format_dhcp_proxy_trace,
 485 #if 0
 486   .unformat_buffer = unformat_dhcp_proxy_header,
 487 #endif
 488 };
 489 /* *INDENT-ON* */
 490
 491 typedef enum
 492 {
 493   DHCP4_PROXY_NEXT_DROP,
 494   DHCP4_PROXY_NEXT_TX,
 495   DHCP4_PROXY_N_NEXT,
 496 } dhcp4_next_t;
 497
 498 static uword
 499 dhcp_proxy_to_client_input (vlib_main_t * vm,
 500                             vlib_node_runtime_t * node,
 501                             vlib_frame_t * from_frame)
 502 {
 503   u32 n_left_from, *from, *to_next, n_left_to_next;
 504   ethernet_main_t *em = vnet_get_ethernet_main ();
 505   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 506   vnet_main_t *vnm = vnet_get_main ();
 507   ip4_main_t *im = &ip4_main;
 508   u32 next_index;
 509
 510   from = vlib_frame_vector_args (from_frame);
 511   n_left_from = from_frame->n_vectors;
 512   next_index = node->cached_next_index;
 513
 514   while (n_left_from > 0)
 515     {
 516       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 517
 518       while (n_left_from > 0 && n_left_to_next > 0)
 519         {
 520           u32 bi0;
 521           vlib_buffer_t *b0;
 522           udp_header_t *u0;
 523           dhcp_header_t *h0;
 524           ip4_header_t *ip0 = 0;
 525           ip4_address_t *ia0 = 0;
 526           u32 old0, new0;
 527           ip_csum_t sum0;
 528           ethernet_interface_t *ei0;
 529           ethernet_header_t *mac0;
 530           vnet_hw_interface_t *hi0;
 531           u32 sw_if_index = ~0;
 532           vnet_sw_interface_t *si0;
 533           u32 inner_vlan = (u32) ~ 0;
 534           u32 outer_vlan = (u32) ~ 0;
 535           u32 error0 = (u32) ~ 0;
 536           vnet_sw_interface_t *swif;
 537           u32 fib_index;
 538           dhcp_proxy_t *proxy;
 539           dhcp_server_t *server;
 540           u32 original_sw_if_index = (u32) ~ 0;
 541           dhcp4_next_t next0 = DHCP4_PROXY_NEXT_TX;
 542           ip4_address_t relay_addr = {
 543             .as_u32 = 0,
 544           };
 545
 546           bi0 = to_next[0] = from[0];
 547           from += 1;
 548           to_next += 1;
 549           n_left_from -= 1;
 550           n_left_to_next -= 1;
 551
 552           b0 = vlib_get_buffer (vm, bi0);
 553           h0 = vlib_buffer_get_current (b0);
 554
 555           /*
 556            * udp_local hands us the DHCP header, need udp hdr,
 557            * ip hdr to relay to client
 558            */
 559           vlib_buffer_advance (b0, -(sizeof (*u0)));
 560           u0 = vlib_buffer_get_current (b0);
 561
 562           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 563           ip0 = vlib_buffer_get_current (b0);
 564
 565           /* Consumed by dhcp client code? */
 566           if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 567             {
 568               error0 = DHCP_PROXY_ERROR_FOR_US;
 569               goto drop_packet;
 570             }
 571
 572           // if (1 /* dpm->insert_option_82 */ )
 573           /* linearize needed to "unclone" and scan options */
 574           int rv = vlib_buffer_chain_linearize (vm, b0);
 575           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
 576             {
 577               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 578               goto drop_packet;
 579             }
 580
 581           dhcp_option_t *o = h0->options, *end =
 582             (void *) vlib_buffer_get_tail (b0);
 583
 584           /* Parse through TLVs looking for option 82.
 585              The circuit-ID is the FIB number we need
 586              to track down the client-facing interface */
 587
 588           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 589             {
 590               if (o->option == 82)
 591                 {
 592                   u32 vss_exist = 0;
 593                   u32 vss_ctrl = 0;
 594                   dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
 595                   dhcp_option_t *subend =
 596                     (dhcp_option_t *) (o->data + o->length);
 597                   while (sub->option != DHCP_PACKET_OPTION_END
 598                          && sub < subend)
 599                     {
 600                       /* If this is one of ours, it will have
 601                          total length 12, circuit-id suboption type,
 602                          and the sw_if_index */
 603                       if (sub->option == 1 && sub->length == 4)
 604                         {
 605                           sw_if_index = ((sub->data[0] << 24) |
 606                                          (sub->data[1] << 16) |
 607                                          (sub->data[2] << 8) |
 608                                          (sub->data[3]));
 609                         }
 610                       else if (sub->option == 5 && sub->length == 4)
 611                         {
 612                           relay_addr.as_u8[0] = sub->data[0];
 613                           relay_addr.as_u8[1] = sub->data[1];
 614                           relay_addr.as_u8[2] = sub->data[2];
 615                           relay_addr.as_u8[3] = sub->data[3];
 616                         }
 617                       else if (sub->option == 151 &&
 618                                sub->length == 7 && sub->data[0] == 1)
 619                         vss_exist = 1;
 620                       else if (sub->option == 152 && sub->length == 0)
 621                         vss_ctrl = 1;
 622                       sub = (dhcp_option_t *) (sub->data + sub->length);
 623                     }
 624                   if (vss_ctrl && vss_exist)
 625                     vlib_node_increment_counter
 626                       (vm, dhcp_proxy_to_client_node.index,
 627                        DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 628
 629                 }
 630               o = (dhcp_option_t *) (o->data + o->length);
 631             }
 632
 633           if (sw_if_index == (u32) ~ 0)
 634             {
 635               error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 636
 637             drop_packet:
 638               vlib_node_increment_counter (vm,
 639                                            dhcp_proxy_to_client_node.index,
 640                                            error0, 1);
 641               b0->error = node->errors[error0];
 642               next0 = DHCP4_PROXY_NEXT_DROP;
 643               goto do_trace;
 644             }
 645
 646           if (relay_addr.as_u32 == 0)
 647             {
 648               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 649               goto drop_packet;
 650             }
 651
 652           if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 653             {
 654               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 655               goto drop_packet;
 656             }
 657
 658           fib_index = im->fib_index_by_sw_if_index[sw_if_index];
 659           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 660
 661           if (PREDICT_FALSE (NULL == proxy))
 662             {
 663               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 664               goto drop_packet;
 665             }
 666
 667           vec_foreach (server, proxy->dhcp_servers)
 668           {
 669             if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
 670               {
 671                 goto server_found;
 672               }
 673           }
 674
 675           error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 676           goto drop_packet;
 677
 678         server_found:
 679           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 680
 681           swif = vnet_get_sw_interface (vnm, sw_if_index);
 682           original_sw_if_index = sw_if_index;
 683           if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 684             sw_if_index = swif->unnumbered_sw_if_index;
 685
 686           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 687           if (ia0 == 0)
 688             {
 689               error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 690               goto drop_packet;
 691             }
 692
 693           if (relay_addr.as_u32 != ia0->as_u32)
 694             {
 695               error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 696               goto drop_packet;
 697             }
 698
 699           u0->checksum = 0;
 700           u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 701           sum0 = ip0->checksum;
 702           old0 = ip0->dst_address.as_u32;
 703           new0 = 0xFFFFFFFF;
 704           ip0->dst_address.as_u32 = new0;
 705           sum0 =
 706             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 707                             dst_address /* offset of changed member */ );
 708           ip0->checksum = ip_csum_fold (sum0);
 709
 710           sum0 = ip0->checksum;
 711           old0 = ip0->src_address.as_u32;
 712           new0 = ia0->as_u32;
 713           ip0->src_address.as_u32 = new0;
 714           sum0 =
 715             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 716                             src_address /* offset of changed member */ );
 717           ip0->checksum = ip_csum_fold (sum0);
 718
 719           vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
 720           si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 721           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 722             {
 723               if (si0->sub.eth.flags.one_tag == 1)
 724                 {
 725                   vlib_buffer_advance (b0, -4 /* space for 1 VLAN tag */ );
 726                   outer_vlan = (si0->sub.eth.outer_vlan_id << 16) | 0x0800;
 727                 }
 728               else if (si0->sub.eth.flags.two_tags == 1)
 729                 {
 730                   vlib_buffer_advance (b0, -8 /* space for 2 VLAN tag */ );
 731                   outer_vlan = (si0->sub.eth.outer_vlan_id << 16) | 0x8100;
 732                   inner_vlan = (si0->sub.eth.inner_vlan_id << 16) | 0x0800;
 733                 }
 734             }
 735
 736           mac0 = vlib_buffer_get_current (b0);
 737
 738           hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 739           ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 740           clib_memcpy (mac0->src_address, &ei0->address,
 741                        sizeof (mac0->src_address));
 742           clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 743
 744           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB
 745               && outer_vlan != (u32) ~ 0)
 746             {
 747               mac0->type = (si0->sub.eth.flags.dot1ad == 1) ?
 748                 clib_net_to_host_u16 (0x88a8) : clib_net_to_host_u16 (0x8100);
 749               u32 *vlan_tag = (u32 *) (mac0 + 1);
 750               *vlan_tag = clib_host_to_net_u32 (outer_vlan);
 751               if (inner_vlan != (u32) ~ 0)
 752                 {
 753                   u32 *inner_vlan_tag = (u32 *) (vlan_tag + 1);
 754                   *inner_vlan_tag = clib_host_to_net_u32 (inner_vlan);
 755                 }
 756             }
 757           else
 758             {
 759               mac0->type = clib_net_to_host_u16 (0x0800);
 760             }
 761
 762         do_trace:
 763           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 764             {
 765               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 766                                                        b0, sizeof (*tr));
 767               tr->which = 1;    /* to client */
 768               tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 769               tr->error = error0;
 770               tr->original_sw_if_index = original_sw_if_index;
 771               tr->sw_if_index = sw_if_index;
 772               clib_memcpy_fast (tr->packet_data, h0,
 773                                 sizeof (tr->packet_data));
 774             }
 775
 776           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 777                                            to_next, n_left_to_next,
 778                                            bi0, next0);
 779         }
 780       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 781     }
 782
 783   return from_frame->n_vectors;
 784 }
 785
 786 /* *INDENT-OFF* */
 787 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
 788   .function = dhcp_proxy_to_client_input,
 789   .name = "dhcp-proxy-to-client",
 790   /* Takes a vector of packets. */
 791   .vector_size = sizeof (u32),
 792
 793   .n_errors = DHCP_PROXY_N_ERROR,
 794   .error_strings = dhcp_proxy_error_strings,
 795   .format_buffer = format_dhcp_proxy_header_with_length,
 796   .format_trace = format_dhcp_proxy_trace,
 797 #if 0
 798   .unformat_buffer = unformat_dhcp_proxy_header,
 799 #endif
 800   .n_next_nodes = DHCP4_PROXY_N_NEXT,
 801   .next_nodes = {
 802     [DHCP4_PROXY_NEXT_DROP] = "error-drop",
 803     [DHCP4_PROXY_NEXT_TX] = "interface-output",
 804   },
 805 };
 806 /* *INDENT-ON* */
 807
 808 void
 809 dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
 810 {
 811   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 812   vlib_main_t *vm = dm->vlib_main;
 813   int port_regs_diff = dm->udp_ports_registered ^ ports;
 814
 815   if (!port_regs_diff)
 816     return;
 817
 818   if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
 819     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 820                            dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
 821
 822   if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
 823     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 824                            dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
 825
 826   dm->udp_ports_registered |= ports;
 827 }
 828
 829 static clib_error_t *
 830 dhcp4_proxy_init (vlib_main_t * vm)
 831 {
 832   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 833   vlib_node_t *error_drop_node;
 834
 835   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 836   dm->error_drop_node_index = error_drop_node->index;
 837   dm->vlib_main = vm;
 838
 839   return 0;
 840 }
 841
 842
 843 VLIB_INIT_FUNCTION (dhcp4_proxy_init);
 844
 845 int
 846 dhcp4_proxy_set_server (ip46_address_t * addr,
 847                         ip46_address_t * src_addr,
 848                         u32 rx_table_id, u32 server_table_id, int is_del)
 849 {
 850   u32 rx_fib_index = 0;
 851   int rc = 0;
 852
 853   const fib_prefix_t all_1s = {
 854     .fp_len = 32,
 855     .fp_addr.ip4.as_u32 = 0xffffffff,
 856     .fp_proto = FIB_PROTOCOL_IP4,
 857   };
 858
 859   if (ip46_address_is_zero (addr))
 860     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 861
 862   if (ip46_address_is_zero (src_addr))
 863     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 864
 865   dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
 866
 867   rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
 868                                                     rx_table_id,
 869                                                     FIB_SOURCE_DHCP);
 870
 871   if (is_del)
 872     {
 873       if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
 874                                  addr, server_table_id))
 875         {
 876           fib_table_entry_special_remove (rx_fib_index,
 877                                           &all_1s, FIB_SOURCE_DHCP);
 878           fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 879         }
 880     }
 881   else
 882     {
 883       if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
 884                                  addr, src_addr,
 885                                  rx_fib_index, server_table_id))
 886         {
 887           fib_table_entry_special_add (rx_fib_index,
 888                                        &all_1s,
 889                                        FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
 890           fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 891         }
 892     }
 893   fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 894
 895   return (rc);
 896 }
 897
 898 static clib_error_t *
 899 dhcp4_proxy_set_command_fn (vlib_main_t * vm,
 900                             unformat_input_t * input,
 901                             vlib_cli_command_t * cmd)
 902 {
 903   ip46_address_t server_addr, src_addr;
 904   u32 server_table_id = 0, rx_table_id = 0;
 905   int is_del = 0;
 906   int set_src = 0, set_server = 0;
 907
 908   clib_memset (&server_addr, 0, sizeof (server_addr));
 909   clib_memset (&src_addr, 0, sizeof (src_addr));
 910
 911   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 912     {
 913       if (unformat (input, "server %U",
 914                     unformat_ip4_address, &server_addr.ip4))
 915         set_server = 1;
 916       else if (unformat (input, "server-fib-id %d", &server_table_id))
 917         ;
 918       else if (unformat (input, "rx-fib-id %d", &rx_table_id))
 919         ;
 920       else if (unformat (input, "src-address %U",
 921                          unformat_ip4_address, &src_addr.ip4))
 922         set_src = 1;
 923       else if (unformat (input, "delete") || unformat (input, "del"))
 924         is_del = 1;
 925       else
 926         break;
 927     }
 928
 929   if (is_del || (set_server && set_src))
 930     {
 931       int rv;
 932
 933       rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
 934                                    server_table_id, is_del);
 935       switch (rv)
 936         {
 937         case 0:
 938           return 0;
 939
 940         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 941           return clib_error_return (0, "Invalid server address");
 942
 943         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 944           return clib_error_return (0, "Invalid src address");
 945
 946         case VNET_API_ERROR_NO_SUCH_ENTRY:
 947           return clib_error_return
 948             (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
 949
 950         default:
 951           return clib_error_return (0, "BUG: rv %d", rv);
 952         }
 953     }
 954   else
 955     return clib_error_return (0, "parse error`%U'",
 956                               format_unformat_error, input);
 957 }
 958
 959 /* *INDENT-OFF* */
 960 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 961   .path = "set dhcp proxy",
 962   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 963   .function = dhcp4_proxy_set_command_fn,
 964 };
 965 /* *INDENT-ON* */
 966
 967 static u8 *
 968 format_dhcp4_proxy_server (u8 * s, va_list * args)
 969 {
 970   dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
 971   ip4_fib_t *rx_fib, *server_fib;
 972   dhcp_server_t *server;
 973
 974   if (proxy == 0)
 975     {
 976       s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
 977                   "Servers FIB,Address");
 978       return s;
 979     }
 980
 981   rx_fib = ip4_fib_get (proxy->rx_fib_index);
 982
 983   s = format (s, "%=14u%=16U", rx_fib->hash.table_id, format_ip46_address,
 984               &proxy->dhcp_src_address, IP46_TYPE_ANY);
 985
 986   vec_foreach (server, proxy->dhcp_servers)
 987   {
 988     server_fib = ip4_fib_get (server->server_fib_index);
 989     s = format (s, "%u,%U  ", server_fib->hash.table_id, format_ip46_address,
 990                 &server->dhcp_server, IP46_TYPE_ANY);
 991   }
 992   return s;
 993 }
 994
 995 static int
 996 dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
 997 {
 998   vlib_main_t *vm = ctx;
 999
1000   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
1001
1002   return (1);
1003 }
1004
1005 static clib_error_t *
1006 dhcp4_proxy_show_command_fn (vlib_main_t * vm,
1007                              unformat_input_t * input,
1008                              vlib_cli_command_t * cmd)
1009 {
1010   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
1011                    NULL /* header line */ );
1012
1013   dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
1014
1015   return (NULL);
1016 }
1017
1018 /* *INDENT-OFF* */
1019 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
1020   .path = "show dhcp proxy",
1021   .short_help = "Display dhcp proxy server info",
1022   .function = dhcp4_proxy_show_command_fn,
1023 };
1024 /* *INDENT-ON* */
1025
1026 static clib_error_t *
1027 dhcp_option_82_vss_fn (vlib_main_t * vm,
1028                        unformat_input_t * input, vlib_cli_command_t * cmd)
1029 {
1030   u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
1031   u32 oui = 0, fib_id = 0, tbl_id = ~0;
1032   u8 *vpn_ascii_id = 0;
1033
1034   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1035     {
1036       if (unformat (input, "table %d", &tbl_id))
1037         ;
1038       else if (unformat (input, "oui %d", &oui))
1039         vss_type = VSS_TYPE_VPN_ID;
1040       else if (unformat (input, "vpn-id %d", &fib_id))
1041         vss_type = VSS_TYPE_VPN_ID;
1042       else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
1043         vss_type = VSS_TYPE_ASCII;
1044       else if (unformat (input, "delete") || unformat (input, "del"))
1045         is_del = 1;
1046       else
1047         break;
1048     }
1049
1050   if (tbl_id == ~0)
1051     return clib_error_return (0, "no table ID specified.");
1052
1053   int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
1054                                vpn_ascii_id, oui, fib_id, is_del);
1055   switch (rv)
1056     {
1057     case 0:
1058       return 0;
1059     case VNET_API_ERROR_NO_SUCH_ENTRY:
1060       return clib_error_return (0,
1061                                 "option 82 vss for table %d not found in in pool.",
1062                                 tbl_id);
1063     default:
1064       return clib_error_return (0, "BUG: rv %d", rv);
1065
1066     }
1067 }
1068
1069 /* *INDENT-OFF* */
1070 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1071   .path = "set dhcp option-82 vss",
1072   .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1073   .function = dhcp_option_82_vss_fn,
1074 };
1075 /* *INDENT-ON* */
1076
1077 static clib_error_t *
1078 dhcp_vss_show_command_fn (vlib_main_t * vm,
1079                           unformat_input_t * input, vlib_cli_command_t * cmd)
1080 {
1081   dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1082
1083   return (NULL);
1084 }
1085
1086 /* *INDENT-OFF* */
1087 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1088   .path = "show dhcp vss",
1089   .short_help = "show dhcp VSS",
1090   .function = dhcp_vss_show_command_fn,
1091 };
1092 /* *INDENT-ON* */
1093
1094 static clib_error_t *
1095 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1096                                         unformat_input_t * input,
1097                                         vlib_cli_command_t * cmd)
1098 {
1099   vnet_main_t *vnm = vnet_get_main ();
1100   u32 sw_if_index0 = 0, sw_if_index;
1101   vnet_sw_interface_t *swif;
1102   ip4_address_t *ia0;
1103
1104   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1105     {
1106
1107       if (unformat (input, "%U",
1108                     unformat_vnet_sw_interface, vnm, &sw_if_index0))
1109         {
1110           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1111           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1112             swif->unnumbered_sw_if_index : sw_if_index0;
1113           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1114           if (ia0)
1115             {
1116               vlib_cli_output (vm, "%=20s%=20s", "interface",
1117                                "source IP address");
1118
1119               vlib_cli_output (vm, "%=20U%=20U",
1120                                format_vnet_sw_if_index_name,
1121                                vnm, sw_if_index0, format_ip4_address, ia0);
1122             }
1123           else
1124             vlib_cli_output (vm, "%=34s %=20U",
1125                              "No IPv4 address configured on",
1126                              format_vnet_sw_if_index_name, vnm, sw_if_index);
1127         }
1128       else
1129         break;
1130     }
1131
1132   return 0;
1133 }
1134
1135 /* *INDENT-OFF* */
1136 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1137   .path = "show dhcp option-82-address interface",
1138   .short_help = "show dhcp option-82-address interface <interface>",
1139   .function = dhcp_option_82_address_show_command_fn,
1140 };
1141 /* *INDENT-ON* */
1142
1143 /*
1144  * fd.io coding-style-patch-verification: ON
1145  *
1146  * Local Variables:
1147  * eval: (c-set-style "gnu")
1148  * End:
1149  */