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                   VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
 374                   ci0 = vlib_get_buffer_index (vm, c0);
 375                   server = &proxy->dhcp_servers[ii];
 376
 377                   ip0 = vlib_buffer_get_current (c0);
 378
 379                   sum0 = ip0->checksum;
 380                   old0 = ip0->dst_address.as_u32;
 381                   new0 = server->dhcp_server.ip4.as_u32;
 382                   ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 383                   sum0 = ip_csum_update (sum0, old0, new0,
 384                                          ip4_header_t /* structure */ ,
 385                                          dst_address /* changed member */ );
 386                   ip0->checksum = ip_csum_fold (sum0);
 387
 388                   to_next[0] = ci0;
 389                   to_next += 1;
 390                   n_left_to_next -= 1;
 391
 392                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 393                                                    to_next, n_left_to_next,
 394                                                    ci0, next0);
 395
 396                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 397                     {
 398                       dhcp_proxy_trace_t *tr;
 399
 400                       tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
 401                       tr->which = 0;    /* to server */
 402                       tr->error = error0;
 403                       tr->original_sw_if_index = original_sw_if_index;
 404                       tr->sw_if_index = sw_if_index;
 405                       if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 406                         tr->trace_ip4_address.as_u32 =
 407                           server->dhcp_server.ip4.as_u32;
 408
 409                       clib_memcpy_fast (tr->packet_data, h0,
 410                                         sizeof (tr->packet_data));
 411
 412                     }
 413
 414                   if (PREDICT_FALSE (0 == n_left_to_next))
 415                     {
 416                       vlib_put_next_frame (vm, node, next_index,
 417                                            n_left_to_next);
 418                       vlib_get_next_frame (vm, node, next_index,
 419                                            to_next, n_left_to_next);
 420                     }
 421                 }
 422             }
 423         do_trace:
 424           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 425             {
 426               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 427                                                        b0, sizeof (*tr));
 428               tr->which = 0;    /* to server */
 429               tr->error = error0;
 430               tr->original_sw_if_index = original_sw_if_index;
 431               tr->sw_if_index = sw_if_index;
 432               if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 433                 tr->trace_ip4_address.as_u32 =
 434                   proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
 435               clib_memcpy_fast (tr->packet_data, h0,
 436                                 sizeof (tr->packet_data));
 437             }
 438
 439         do_enqueue:
 440           to_next[0] = bi0;
 441           to_next += 1;
 442           n_left_to_next -= 1;
 443
 444           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 445                                            to_next, n_left_to_next,
 446                                            bi0, next0);
 447         }
 448
 449       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 450     }
 451   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 452                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 453                                pkts_to_client);
 454   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 455                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 456                                pkts_to_server);
 457   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 458                                DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
 459   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 460                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 461                                pkts_no_interface_address);
 462   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 463                                DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
 464   return from_frame->n_vectors;
 465 }
 466
 467 /* *INDENT-OFF* */
 468 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
 469   .function = dhcp_proxy_to_server_input,
 470   .name = "dhcp-proxy-to-server",
 471   /* Takes a vector of packets. */
 472   .vector_size = sizeof (u32),
 473
 474   .n_errors = DHCP_PROXY_N_ERROR,
 475   .error_strings = dhcp_proxy_error_strings,
 476
 477   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 478   .next_nodes = {
 479 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 480     foreach_dhcp_proxy_to_server_input_next
 481 #undef _
 482   },
 483
 484   .format_buffer = format_dhcp_proxy_header_with_length,
 485   .format_trace = format_dhcp_proxy_trace,
 486 #if 0
 487   .unformat_buffer = unformat_dhcp_proxy_header,
 488 #endif
 489 };
 490 /* *INDENT-ON* */
 491
 492 typedef enum
 493 {
 494   DHCP4_PROXY_NEXT_DROP,
 495   DHCP4_PROXY_NEXT_TX,
 496   DHCP4_PROXY_N_NEXT,
 497 } dhcp4_next_t;
 498
 499 static uword
 500 dhcp_proxy_to_client_input (vlib_main_t * vm,
 501                             vlib_node_runtime_t * node,
 502                             vlib_frame_t * from_frame)
 503 {
 504   u32 n_left_from, *from, *to_next, n_left_to_next;
 505   ethernet_main_t *em = vnet_get_ethernet_main ();
 506   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 507   vnet_main_t *vnm = vnet_get_main ();
 508   ip4_main_t *im = &ip4_main;
 509   u32 next_index;
 510
 511   from = vlib_frame_vector_args (from_frame);
 512   n_left_from = from_frame->n_vectors;
 513   next_index = node->cached_next_index;
 514
 515   while (n_left_from > 0)
 516     {
 517       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 518
 519       while (n_left_from > 0 && n_left_to_next > 0)
 520         {
 521           u32 bi0;
 522           vlib_buffer_t *b0;
 523           udp_header_t *u0;
 524           dhcp_header_t *h0;
 525           ip4_header_t *ip0 = 0;
 526           ip4_address_t *ia0 = 0;
 527           u32 old0, new0;
 528           ip_csum_t sum0;
 529           ethernet_interface_t *ei0;
 530           ethernet_header_t *mac0;
 531           vnet_hw_interface_t *hi0;
 532           u32 sw_if_index = ~0;
 533           vnet_sw_interface_t *si0;
 534           u32 inner_vlan = (u32) ~ 0;
 535           u32 outer_vlan = (u32) ~ 0;
 536           u32 error0 = (u32) ~ 0;
 537           vnet_sw_interface_t *swif;
 538           u32 fib_index;
 539           dhcp_proxy_t *proxy;
 540           dhcp_server_t *server;
 541           u32 original_sw_if_index = (u32) ~ 0;
 542           dhcp4_next_t next0 = DHCP4_PROXY_NEXT_TX;
 543           ip4_address_t relay_addr = {
 544             .as_u32 = 0,
 545           };
 546
 547           bi0 = to_next[0] = from[0];
 548           from += 1;
 549           to_next += 1;
 550           n_left_from -= 1;
 551           n_left_to_next -= 1;
 552
 553           b0 = vlib_get_buffer (vm, bi0);
 554           h0 = vlib_buffer_get_current (b0);
 555
 556           /*
 557            * udp_local hands us the DHCP header, need udp hdr,
 558            * ip hdr to relay to client
 559            */
 560           vlib_buffer_advance (b0, -(sizeof (*u0)));
 561           u0 = vlib_buffer_get_current (b0);
 562
 563           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 564           ip0 = vlib_buffer_get_current (b0);
 565
 566           /* Consumed by dhcp client code? */
 567           if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 568             {
 569               error0 = DHCP_PROXY_ERROR_FOR_US;
 570               goto drop_packet;
 571             }
 572
 573           // if (1 /* dpm->insert_option_82 */ )
 574           /* linearize needed to "unclone" and scan options */
 575           int rv = vlib_buffer_chain_linearize (vm, b0);
 576           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
 577             {
 578               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 579               goto drop_packet;
 580             }
 581
 582           dhcp_option_t *o = h0->options, *end =
 583             (void *) vlib_buffer_get_tail (b0);
 584
 585           /* Parse through TLVs looking for option 82.
 586              The circuit-ID is the FIB number we need
 587              to track down the client-facing interface */
 588
 589           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 590             {
 591               if (o->option == 82)
 592                 {
 593                   u32 vss_exist = 0;
 594                   u32 vss_ctrl = 0;
 595                   dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
 596                   dhcp_option_t *subend =
 597                     (dhcp_option_t *) (o->data + o->length);
 598                   while (sub->option != DHCP_PACKET_OPTION_END
 599                          && sub < subend)
 600                     {
 601                       /* If this is one of ours, it will have
 602                          total length 12, circuit-id suboption type,
 603                          and the sw_if_index */
 604                       if (sub->option == 1 && sub->length == 4)
 605                         {
 606                           sw_if_index = ((sub->data[0] << 24) |
 607                                          (sub->data[1] << 16) |
 608                                          (sub->data[2] << 8) |
 609                                          (sub->data[3]));
 610                         }
 611                       else if (sub->option == 5 && sub->length == 4)
 612                         {
 613                           relay_addr.as_u8[0] = sub->data[0];
 614                           relay_addr.as_u8[1] = sub->data[1];
 615                           relay_addr.as_u8[2] = sub->data[2];
 616                           relay_addr.as_u8[3] = sub->data[3];
 617                         }
 618                       else if (sub->option == 151 &&
 619                                sub->length == 7 && sub->data[0] == 1)
 620                         vss_exist = 1;
 621                       else if (sub->option == 152 && sub->length == 0)
 622                         vss_ctrl = 1;
 623                       sub = (dhcp_option_t *) (sub->data + sub->length);
 624                     }
 625                   if (vss_ctrl && vss_exist)
 626                     vlib_node_increment_counter
 627                       (vm, dhcp_proxy_to_client_node.index,
 628                        DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 629
 630                 }
 631               o = (dhcp_option_t *) (o->data + o->length);
 632             }
 633
 634           if (sw_if_index == (u32) ~ 0)
 635             {
 636               error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 637
 638             drop_packet:
 639               vlib_node_increment_counter (vm,
 640                                            dhcp_proxy_to_client_node.index,
 641                                            error0, 1);
 642               b0->error = node->errors[error0];
 643               next0 = DHCP4_PROXY_NEXT_DROP;
 644               goto do_trace;
 645             }
 646
 647           if (relay_addr.as_u32 == 0)
 648             {
 649               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 650               goto drop_packet;
 651             }
 652
 653           if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 654             {
 655               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 656               goto drop_packet;
 657             }
 658
 659           fib_index = im->fib_index_by_sw_if_index[sw_if_index];
 660           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 661
 662           if (PREDICT_FALSE (NULL == proxy))
 663             {
 664               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 665               goto drop_packet;
 666             }
 667
 668           vec_foreach (server, proxy->dhcp_servers)
 669           {
 670             if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
 671               {
 672                 goto server_found;
 673               }
 674           }
 675
 676           error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 677           goto drop_packet;
 678
 679         server_found:
 680           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 681
 682           swif = vnet_get_sw_interface (vnm, sw_if_index);
 683           original_sw_if_index = sw_if_index;
 684           if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 685             sw_if_index = swif->unnumbered_sw_if_index;
 686
 687           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 688           if (ia0 == 0)
 689             {
 690               error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 691               goto drop_packet;
 692             }
 693
 694           if (relay_addr.as_u32 != ia0->as_u32)
 695             {
 696               error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 697               goto drop_packet;
 698             }
 699
 700           u0->checksum = 0;
 701           u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 702           sum0 = ip0->checksum;
 703           old0 = ip0->dst_address.as_u32;
 704           new0 = 0xFFFFFFFF;
 705           ip0->dst_address.as_u32 = new0;
 706           sum0 =
 707             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 708                             dst_address /* offset of changed member */ );
 709           ip0->checksum = ip_csum_fold (sum0);
 710
 711           sum0 = ip0->checksum;
 712           old0 = ip0->src_address.as_u32;
 713           new0 = ia0->as_u32;
 714           ip0->src_address.as_u32 = new0;
 715           sum0 =
 716             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 717                             src_address /* offset of changed member */ );
 718           ip0->checksum = ip_csum_fold (sum0);
 719
 720           vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
 721           si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 722           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 723             {
 724               if (si0->sub.eth.flags.one_tag == 1)
 725                 {
 726                   vlib_buffer_advance (b0, -4 /* space for 1 VLAN tag */ );
 727                   outer_vlan = (si0->sub.eth.outer_vlan_id << 16) | 0x0800;
 728                 }
 729               else if (si0->sub.eth.flags.two_tags == 1)
 730                 {
 731                   vlib_buffer_advance (b0, -8 /* space for 2 VLAN tag */ );
 732                   outer_vlan = (si0->sub.eth.outer_vlan_id << 16) | 0x8100;
 733                   inner_vlan = (si0->sub.eth.inner_vlan_id << 16) | 0x0800;
 734                 }
 735             }
 736
 737           mac0 = vlib_buffer_get_current (b0);
 738
 739           hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 740           ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 741           clib_memcpy (mac0->src_address, ei0->address,
 742                        sizeof (ei0->address));
 743           clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 744
 745           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB
 746               && outer_vlan != (u32) ~ 0)
 747             {
 748               mac0->type = (si0->sub.eth.flags.dot1ad == 1) ?
 749                 clib_net_to_host_u16 (0x88a8) : clib_net_to_host_u16 (0x8100);
 750               u32 *vlan_tag = (u32 *) (mac0 + 1);
 751               *vlan_tag = clib_host_to_net_u32 (outer_vlan);
 752               if (inner_vlan != (u32) ~ 0)
 753                 {
 754                   u32 *inner_vlan_tag = (u32 *) (vlan_tag + 1);
 755                   *inner_vlan_tag = clib_host_to_net_u32 (inner_vlan);
 756                 }
 757             }
 758           else
 759             {
 760               mac0->type = clib_net_to_host_u16 (0x0800);
 761             }
 762
 763         do_trace:
 764           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 765             {
 766               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 767                                                        b0, sizeof (*tr));
 768               tr->which = 1;    /* to client */
 769               tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 770               tr->error = error0;
 771               tr->original_sw_if_index = original_sw_if_index;
 772               tr->sw_if_index = sw_if_index;
 773               clib_memcpy_fast (tr->packet_data, h0,
 774                                 sizeof (tr->packet_data));
 775             }
 776
 777           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 778                                            to_next, n_left_to_next,
 779                                            bi0, next0);
 780         }
 781       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 782     }
 783
 784   return from_frame->n_vectors;
 785 }
 786
 787 /* *INDENT-OFF* */
 788 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
 789   .function = dhcp_proxy_to_client_input,
 790   .name = "dhcp-proxy-to-client",
 791   /* Takes a vector of packets. */
 792   .vector_size = sizeof (u32),
 793
 794   .n_errors = DHCP_PROXY_N_ERROR,
 795   .error_strings = dhcp_proxy_error_strings,
 796   .format_buffer = format_dhcp_proxy_header_with_length,
 797   .format_trace = format_dhcp_proxy_trace,
 798 #if 0
 799   .unformat_buffer = unformat_dhcp_proxy_header,
 800 #endif
 801   .n_next_nodes = DHCP4_PROXY_N_NEXT,
 802   .next_nodes = {
 803     [DHCP4_PROXY_NEXT_DROP] = "error-drop",
 804     [DHCP4_PROXY_NEXT_TX] = "interface-output",
 805   },
 806 };
 807 /* *INDENT-ON* */
 808
 809 void
 810 dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
 811 {
 812   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 813   vlib_main_t *vm = dm->vlib_main;
 814   int port_regs_diff = dm->udp_ports_registered ^ ports;
 815
 816   if (!port_regs_diff)
 817     return;
 818
 819   if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
 820     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 821                            dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
 822
 823   if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
 824     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 825                            dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
 826
 827   dm->udp_ports_registered |= ports;
 828 }
 829
 830 static clib_error_t *
 831 dhcp4_proxy_init (vlib_main_t * vm)
 832 {
 833   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 834   vlib_node_t *error_drop_node;
 835
 836   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 837   dm->error_drop_node_index = error_drop_node->index;
 838   dm->vlib_main = vm;
 839
 840   return 0;
 841 }
 842
 843
 844 VLIB_INIT_FUNCTION (dhcp4_proxy_init);
 845
 846 int
 847 dhcp4_proxy_set_server (ip46_address_t * addr,
 848                         ip46_address_t * src_addr,
 849                         u32 rx_table_id, u32 server_table_id, int is_del)
 850 {
 851   u32 rx_fib_index = 0;
 852   int rc = 0;
 853
 854   const fib_prefix_t all_1s = {
 855     .fp_len = 32,
 856     .fp_addr.ip4.as_u32 = 0xffffffff,
 857     .fp_proto = FIB_PROTOCOL_IP4,
 858   };
 859
 860   if (ip46_address_is_zero (addr))
 861     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 862
 863   if (ip46_address_is_zero (src_addr))
 864     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 865
 866   dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
 867
 868   rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
 869                                                     rx_table_id,
 870                                                     FIB_SOURCE_DHCP);
 871
 872   if (is_del)
 873     {
 874       if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
 875                                  addr, server_table_id))
 876         {
 877           fib_table_entry_special_remove (rx_fib_index,
 878                                           &all_1s, FIB_SOURCE_DHCP);
 879           fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 880         }
 881     }
 882   else
 883     {
 884       if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
 885                                  addr, src_addr,
 886                                  rx_fib_index, server_table_id))
 887         {
 888           fib_table_entry_special_add (rx_fib_index,
 889                                        &all_1s,
 890                                        FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
 891           fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 892         }
 893     }
 894   fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 895
 896   return (rc);
 897 }
 898
 899 static clib_error_t *
 900 dhcp4_proxy_set_command_fn (vlib_main_t * vm,
 901                             unformat_input_t * input,
 902                             vlib_cli_command_t * cmd)
 903 {
 904   ip46_address_t server_addr, src_addr;
 905   u32 server_table_id = 0, rx_table_id = 0;
 906   int is_del = 0;
 907   int set_src = 0, set_server = 0;
 908
 909   clib_memset (&server_addr, 0, sizeof (server_addr));
 910   clib_memset (&src_addr, 0, sizeof (src_addr));
 911
 912   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 913     {
 914       if (unformat (input, "server %U",
 915                     unformat_ip4_address, &server_addr.ip4))
 916         set_server = 1;
 917       else if (unformat (input, "server-fib-id %d", &server_table_id))
 918         ;
 919       else if (unformat (input, "rx-fib-id %d", &rx_table_id))
 920         ;
 921       else if (unformat (input, "src-address %U",
 922                          unformat_ip4_address, &src_addr.ip4))
 923         set_src = 1;
 924       else if (unformat (input, "delete") || unformat (input, "del"))
 925         is_del = 1;
 926       else
 927         break;
 928     }
 929
 930   if (is_del || (set_server && set_src))
 931     {
 932       int rv;
 933
 934       rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
 935                                    server_table_id, is_del);
 936       switch (rv)
 937         {
 938         case 0:
 939           return 0;
 940
 941         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 942           return clib_error_return (0, "Invalid server address");
 943
 944         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 945           return clib_error_return (0, "Invalid src address");
 946
 947         case VNET_API_ERROR_NO_SUCH_ENTRY:
 948           return clib_error_return
 949             (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
 950
 951         default:
 952           return clib_error_return (0, "BUG: rv %d", rv);
 953         }
 954     }
 955   else
 956     return clib_error_return (0, "parse error`%U'",
 957                               format_unformat_error, input);
 958 }
 959
 960 /* *INDENT-OFF* */
 961 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 962   .path = "set dhcp proxy",
 963   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 964   .function = dhcp4_proxy_set_command_fn,
 965 };
 966 /* *INDENT-ON* */
 967
 968 static u8 *
 969 format_dhcp4_proxy_server (u8 * s, va_list * args)
 970 {
 971   dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
 972   ip4_fib_t *rx_fib, *server_fib;
 973   dhcp_server_t *server;
 974
 975   if (proxy == 0)
 976     {
 977       s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
 978                   "Servers FIB,Address");
 979       return s;
 980     }
 981
 982   rx_fib = ip4_fib_get (proxy->rx_fib_index);
 983
 984   s = format (s, "%=14u%=16U",
 985               rx_fib->table_id,
 986               format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
 987
 988   vec_foreach (server, proxy->dhcp_servers)
 989   {
 990     server_fib = ip4_fib_get (server->server_fib_index);
 991     s = format (s, "%u,%U  ",
 992                 server_fib->table_id,
 993                 format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
 994   }
 995   return s;
 996 }
 997
 998 static int
 999 dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
1000 {
1001   vlib_main_t *vm = ctx;
1002
1003   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
1004
1005   return (1);
1006 }
1007
1008 static clib_error_t *
1009 dhcp4_proxy_show_command_fn (vlib_main_t * vm,
1010                              unformat_input_t * input,
1011                              vlib_cli_command_t * cmd)
1012 {
1013   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
1014                    NULL /* header line */ );
1015
1016   dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
1017
1018   return (NULL);
1019 }
1020
1021 /* *INDENT-OFF* */
1022 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
1023   .path = "show dhcp proxy",
1024   .short_help = "Display dhcp proxy server info",
1025   .function = dhcp4_proxy_show_command_fn,
1026 };
1027 /* *INDENT-ON* */
1028
1029 static clib_error_t *
1030 dhcp_option_82_vss_fn (vlib_main_t * vm,
1031                        unformat_input_t * input, vlib_cli_command_t * cmd)
1032 {
1033   u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
1034   u32 oui = 0, fib_id = 0, tbl_id = ~0;
1035   u8 *vpn_ascii_id = 0;
1036
1037   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1038     {
1039       if (unformat (input, "table %d", &tbl_id))
1040         ;
1041       else if (unformat (input, "oui %d", &oui))
1042         vss_type = VSS_TYPE_VPN_ID;
1043       else if (unformat (input, "vpn-id %d", &fib_id))
1044         vss_type = VSS_TYPE_VPN_ID;
1045       else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
1046         vss_type = VSS_TYPE_ASCII;
1047       else if (unformat (input, "delete") || unformat (input, "del"))
1048         is_del = 1;
1049       else
1050         break;
1051     }
1052
1053   if (tbl_id == ~0)
1054     return clib_error_return (0, "no table ID specified.");
1055
1056   int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
1057                                vpn_ascii_id, oui, fib_id, is_del);
1058   switch (rv)
1059     {
1060     case 0:
1061       return 0;
1062     case VNET_API_ERROR_NO_SUCH_ENTRY:
1063       return clib_error_return (0,
1064                                 "option 82 vss for table %d not found in in pool.",
1065                                 tbl_id);
1066     default:
1067       return clib_error_return (0, "BUG: rv %d", rv);
1068
1069     }
1070 }
1071
1072 /* *INDENT-OFF* */
1073 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1074   .path = "set dhcp option-82 vss",
1075   .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1076   .function = dhcp_option_82_vss_fn,
1077 };
1078 /* *INDENT-ON* */
1079
1080 static clib_error_t *
1081 dhcp_vss_show_command_fn (vlib_main_t * vm,
1082                           unformat_input_t * input, vlib_cli_command_t * cmd)
1083 {
1084   dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1085
1086   return (NULL);
1087 }
1088
1089 /* *INDENT-OFF* */
1090 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1091   .path = "show dhcp vss",
1092   .short_help = "show dhcp VSS",
1093   .function = dhcp_vss_show_command_fn,
1094 };
1095 /* *INDENT-ON* */
1096
1097 static clib_error_t *
1098 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1099                                         unformat_input_t * input,
1100                                         vlib_cli_command_t * cmd)
1101 {
1102   vnet_main_t *vnm = vnet_get_main ();
1103   u32 sw_if_index0 = 0, sw_if_index;
1104   vnet_sw_interface_t *swif;
1105   ip4_address_t *ia0;
1106
1107   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1108     {
1109
1110       if (unformat (input, "%U",
1111                     unformat_vnet_sw_interface, vnm, &sw_if_index0))
1112         {
1113           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1114           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1115             swif->unnumbered_sw_if_index : sw_if_index0;
1116           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1117           if (ia0)
1118             {
1119               vlib_cli_output (vm, "%=20s%=20s", "interface",
1120                                "source IP address");
1121
1122               vlib_cli_output (vm, "%=20U%=20U",
1123                                format_vnet_sw_if_index_name,
1124                                vnm, sw_if_index0, format_ip4_address, ia0);
1125             }
1126           else
1127             vlib_cli_output (vm, "%=34s %=20U",
1128                              "No IPv4 address configured on",
1129                              format_vnet_sw_if_index_name, vnm, sw_if_index);
1130         }
1131       else
1132         break;
1133     }
1134
1135   return 0;
1136 }
1137
1138 /* *INDENT-OFF* */
1139 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1140   .path = "show dhcp option-82-address interface",
1141   .short_help = "show dhcp option-82-address interface <interface>",
1142   .function = dhcp_option_82_address_show_command_fn,
1143 };
1144 /* *INDENT-ON* */
1145
1146 /*
1147  * fd.io coding-style-patch-verification: ON
1148  *
1149  * Local Variables:
1150  * eval: (c-set-style "gnu")
1151  * End:
1152  */