src/vnet/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 <vnet/pg/pg.h>
  20 #include <vnet/dhcp/dhcp_proxy.h>
  21 #include <vnet/dhcp/client.h>
  22 #include <vnet/fib/ip4_fib.h>
  23
  24 static char *dhcp_proxy_error_strings[] = {
  25 #define dhcp_proxy_error(n,s) s,
  26 #include <vnet/dhcp/dhcp4_proxy_error.def>
  27 #undef dhcp_proxy_error
  28 };
  29
  30 #define foreach_dhcp_proxy_to_server_input_next \
  31   _ (DROP, "error-drop")                        \
  32   _ (LOOKUP, "ip4-lookup")                      \
  33   _ (SEND_TO_CLIENT, "dhcp-proxy-to-client")
  34
  35 typedef enum
  36 {
  37 #define _(s,n) DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s,
  38   foreach_dhcp_proxy_to_server_input_next
  39 #undef _
  40     DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
  41 } dhcp_proxy_to_server_input_next_t;
  42
  43 typedef struct
  44 {
  45   /* 0 => to server, 1 => to client */
  46   int which;
  47   ip4_address_t trace_ip4_address;
  48   u32 error;
  49   u32 sw_if_index;
  50   u32 original_sw_if_index;
  51 } dhcp_proxy_trace_t;
  52
  53 #define VPP_DHCP_OPTION82_SUB1_SIZE   6
  54 #define VPP_DHCP_OPTION82_SUB5_SIZE   6
  55 #define VPP_DHCP_OPTION82_VSS_SIZE    12
  56 #define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
  57                                 VPP_DHCP_OPTION82_SUB5_SIZE + \
  58                                 VPP_DHCP_OPTION82_VSS_SIZE +3)
  59
  60 static vlib_node_registration_t dhcp_proxy_to_server_node;
  61 static vlib_node_registration_t dhcp_proxy_to_client_node;
  62
  63 static u8 *
  64 format_dhcp_proxy_trace (u8 * s, va_list * args)
  65 {
  66   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  67   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  68   dhcp_proxy_trace_t *t = va_arg (*args, dhcp_proxy_trace_t *);
  69
  70   if (t->which == 0)
  71     s = format (s, "DHCP proxy: sent to server %U\n",
  72                 format_ip4_address, &t->trace_ip4_address, t->error);
  73   else
  74     s = format (s, "DHCP proxy: broadcast to client from %U\n",
  75                 format_ip4_address, &t->trace_ip4_address);
  76
  77   if (t->error != (u32) ~ 0)
  78     s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
  79
  80   s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
  81               t->original_sw_if_index, t->sw_if_index);
  82
  83   return s;
  84 }
  85
  86 static u8 *
  87 format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
  88 {
  89   dhcp_header_t *h = va_arg (*args, dhcp_header_t *);
  90   u32 max_header_bytes = va_arg (*args, u32);
  91   u32 header_bytes;
  92
  93   header_bytes = sizeof (h[0]);
  94   if (max_header_bytes != 0 && header_bytes > max_header_bytes)
  95     return format (s, "dhcp header truncated");
  96
  97   s = format (s, "DHCP Proxy");
  98
  99   return s;
 100 }
 101
 102 static uword
 103 dhcp_proxy_to_server_input (vlib_main_t * vm,
 104                             vlib_node_runtime_t * node,
 105                             vlib_frame_t * from_frame)
 106 {
 107   u32 n_left_from, next_index, *from, *to_next;
 108   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 109   from = vlib_frame_vector_args (from_frame);
 110   n_left_from = from_frame->n_vectors;
 111   u32 pkts_to_server = 0, pkts_to_client = 0, pkts_no_server = 0;
 112   u32 pkts_no_interface_address = 0;
 113   u32 pkts_too_big = 0;
 114   ip4_main_t *im = &ip4_main;
 115
 116   next_index = node->cached_next_index;
 117
 118   while (n_left_from > 0)
 119     {
 120       u32 n_left_to_next;
 121
 122       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 123
 124       while (n_left_from > 0 && n_left_to_next > 0)
 125         {
 126           u32 bi0;
 127           vlib_buffer_t *b0;
 128           udp_header_t *u0;
 129           dhcp_header_t *h0;
 130           ip4_header_t *ip0;
 131           u32 next0;
 132           u32 old0, new0;
 133           ip_csum_t sum0;
 134           u32 error0 = (u32) ~ 0;
 135           u32 sw_if_index = 0;
 136           u32 original_sw_if_index = 0;
 137           u32 fib_index;
 138           dhcp_proxy_t *proxy;
 139           dhcp_server_t *server;
 140           u32 rx_sw_if_index;
 141           dhcp_option_t *o, *end;
 142           u32 len = 0;
 143           u8 is_discover = 0;
 144           int space_left;
 145
 146           bi0 = from[0];
 147           from += 1;
 148           n_left_from -= 1;
 149
 150           b0 = vlib_get_buffer (vm, bi0);
 151
 152           h0 = vlib_buffer_get_current (b0);
 153
 154           /*
 155            * udp_local hands us the DHCP header, need udp hdr,
 156            * ip hdr to relay to server
 157            */
 158           vlib_buffer_advance (b0, -(sizeof (*u0)));
 159           u0 = vlib_buffer_get_current (b0);
 160
 161           /* This blows. Return traffic has src_port = 67, dst_port = 67 */
 162           if (u0->src_port ==
 163               clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_server))
 164             {
 165               vlib_buffer_advance (b0, sizeof (*u0));
 166               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
 167               error0 = 0;
 168               pkts_to_client++;
 169               goto do_enqueue;
 170             }
 171
 172           rx_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 173           fib_index = im->fib_index_by_sw_if_index[rx_sw_if_index];
 174           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 175
 176           if (PREDICT_FALSE (NULL == proxy))
 177             {
 178               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 179               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 180               pkts_no_server++;
 181               goto do_trace;
 182             }
 183
 184           space_left = vlib_buffer_chain_linearize (vm, b0);
 185           /* cant parse chains...
 186            * and we need some space for option 82*/
 187           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
 188               space_left < VPP_DHCP_OPTION82_SIZE)
 189             {
 190               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 191               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 192               pkts_too_big++;
 193               goto do_trace;
 194             }
 195
 196           server = &proxy->dhcp_servers[0];
 197           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 198           ip0 = vlib_buffer_get_current (b0);
 199
 200           /* disable UDP checksum */
 201           u0->checksum = 0;
 202           sum0 = ip0->checksum;
 203           old0 = ip0->dst_address.as_u32;
 204           new0 = server->dhcp_server.ip4.as_u32;
 205           ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 206           sum0 = ip_csum_update (sum0, old0, new0,
 207                                  ip4_header_t /* structure */ ,
 208                                  dst_address /* changed member */ );
 209           ip0->checksum = ip_csum_fold (sum0);
 210
 211           sum0 = ip0->checksum;
 212           old0 = ip0->src_address.as_u32;
 213           new0 = proxy->dhcp_src_address.ip4.as_u32;
 214           ip0->src_address.as_u32 = new0;
 215           sum0 = ip_csum_update (sum0, old0, new0,
 216                                  ip4_header_t /* structure */ ,
 217                                  src_address /* changed member */ );
 218           ip0->checksum = ip_csum_fold (sum0);
 219
 220           /* Send to DHCP server via the configured FIB */
 221           vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
 222
 223           h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
 224           pkts_to_server++;
 225
 226           o = h0->options;
 227           end = (void *) vlib_buffer_get_tail (b0);
 228
 229           /* TLVs are not performance-friendly... */
 230           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 231             {
 232               if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
 233                 {
 234                   if (DHCP_PACKET_DISCOVER == o->data[0])
 235                     {
 236                       is_discover = 1;
 237                     }
 238                 }
 239               o = (dhcp_option_t *) (o->data + o->length);
 240             }
 241
 242           if (o->option == DHCP_PACKET_OPTION_END && o <= end)
 243             {
 244               vnet_main_t *vnm = vnet_get_main ();
 245               u16 old_l0, new_l0;
 246               ip4_address_t _ia0, *ia0 = &_ia0;
 247               dhcp_vss_t *vss;
 248               vnet_sw_interface_t *swif;
 249
 250               original_sw_if_index = sw_if_index =
 251                 vnet_buffer (b0)->sw_if_index[VLIB_RX];
 252               swif = vnet_get_sw_interface (vnm, sw_if_index);
 253               if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 254                 sw_if_index = swif->unnumbered_sw_if_index;
 255
 256               /*
 257                * Get the first ip4 address on the [client-side]
 258                * RX interface, if not unnumbered. otherwise use
 259                * the loopback interface's ip address.
 260                */
 261               ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 262
 263               if (ia0 == 0)
 264                 {
 265                   error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 266                   next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 267                   pkts_no_interface_address++;
 268                   goto do_trace;
 269                 }
 270
 271               /* Add option 82 */
 272               o->option = 82;   /* option 82 */
 273               o->length = 12;   /* 12 octets to follow */
 274               o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
 275               o->data[1] = 4;   /* length of suboption */
 276               u32 *o_ifid = (u32 *) & o->data[2];
 277               *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
 278               o->data[6] = 5;   /* suboption 5 (client RX intfc address) */
 279               o->data[7] = 4;   /* length 4 */
 280               u32 *o_addr = (u32 *) & o->data[8];
 281               *o_addr = ia0->as_u32;
 282               o->data[12] = DHCP_PACKET_OPTION_END;
 283
 284               vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
 285               if (vss)
 286                 {
 287                   u32 id_len;   /* length of VPN ID */
 288
 289                   if (vss->vss_type == VSS_TYPE_VPN_ID)
 290                     {
 291                       id_len = sizeof (vss->vpn_id);    /* vpn_id is 7 bytes */
 292                       memcpy (&o->data[15], vss->vpn_id, id_len);
 293                     }
 294                   else if (vss->vss_type == VSS_TYPE_ASCII)
 295                     {
 296                       id_len = vec_len (vss->vpn_ascii_id);
 297                       memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
 298                     }
 299                   else          /* must be VSS_TYPE_DEFAULT, no VPN ID */
 300                     id_len = 0;
 301
 302                   o->data[12] = 151;    /* vss suboption */
 303                   o->data[13] = id_len + 1;     /* length: vss_type + id_len */
 304                   o->data[14] = vss->vss_type;  /* vss option type */
 305                   o->data[15 + id_len] = 152;   /* vss control suboption */
 306                   o->data[16 + id_len] = 0;     /* length */
 307                   o->data[17 + id_len] = DHCP_PACKET_OPTION_END;        /* "end-of-options" (0xFF) */
 308                   /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
 309                   o->length += id_len + 5;
 310                 }
 311
 312               len = o->length + 3;
 313               b0->current_length += len;
 314               /* Fix IP header length and checksum */
 315               old_l0 = ip0->length;
 316               new_l0 = clib_net_to_host_u16 (old_l0);
 317               new_l0 += len;
 318               new_l0 = clib_host_to_net_u16 (new_l0);
 319               ip0->length = new_l0;
 320               sum0 = ip0->checksum;
 321               sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
 322                                      length /* changed member */ );
 323               ip0->checksum = ip_csum_fold (sum0);
 324
 325               /* Fix UDP length */
 326               new_l0 = clib_net_to_host_u16 (u0->length);
 327               new_l0 += len;
 328               u0->length = clib_host_to_net_u16 (new_l0);
 329             }
 330           else
 331             {
 332               vlib_node_increment_counter
 333                 (vm, dhcp_proxy_to_server_node.index,
 334                  DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
 335             }
 336
 337           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 338
 339           /*
 340            * If we have multiple servers configured and this is the
 341            * client's discover message, then send copies to each of
 342            * those servers
 343            */
 344           if (is_discover && vec_len (proxy->dhcp_servers) > 1)
 345             {
 346               u32 ii;
 347
 348               for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
 349                 {
 350                   vlib_buffer_t *c0;
 351                   u32 ci0;
 352
 353                   c0 = vlib_buffer_copy (vm, b0);
 354                   vlib_buffer_copy_trace_flag (vm, c0, bi0);
 355                   VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
 356                   ci0 = vlib_get_buffer_index (vm, c0);
 357                   server = &proxy->dhcp_servers[ii];
 358
 359                   ip0 = vlib_buffer_get_current (c0);
 360
 361                   sum0 = ip0->checksum;
 362                   old0 = ip0->dst_address.as_u32;
 363                   new0 = server->dhcp_server.ip4.as_u32;
 364                   ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 365                   sum0 = ip_csum_update (sum0, old0, new0,
 366                                          ip4_header_t /* structure */ ,
 367                                          dst_address /* changed member */ );
 368                   ip0->checksum = ip_csum_fold (sum0);
 369
 370                   to_next[0] = ci0;
 371                   to_next += 1;
 372                   n_left_to_next -= 1;
 373
 374                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 375                                                    to_next, n_left_to_next,
 376                                                    ci0, next0);
 377
 378                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 379                     {
 380                       dhcp_proxy_trace_t *tr;
 381
 382                       tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
 383                       tr->which = 0;    /* to server */
 384                       tr->error = error0;
 385                       tr->original_sw_if_index = original_sw_if_index;
 386                       tr->sw_if_index = sw_if_index;
 387                       if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 388                         tr->trace_ip4_address.as_u32 =
 389                           server->dhcp_server.ip4.as_u32;
 390                     }
 391
 392                   if (PREDICT_FALSE (0 == n_left_to_next))
 393                     {
 394                       vlib_put_next_frame (vm, node, next_index,
 395                                            n_left_to_next);
 396                       vlib_get_next_frame (vm, node, next_index,
 397                                            to_next, n_left_to_next);
 398                     }
 399                 }
 400             }
 401         do_trace:
 402           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 403             {
 404               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 405                                                        b0, sizeof (*tr));
 406               tr->which = 0;    /* to server */
 407               tr->error = error0;
 408               tr->original_sw_if_index = original_sw_if_index;
 409               tr->sw_if_index = sw_if_index;
 410               if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 411                 tr->trace_ip4_address.as_u32 =
 412                   proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
 413             }
 414
 415         do_enqueue:
 416           to_next[0] = bi0;
 417           to_next += 1;
 418           n_left_to_next -= 1;
 419
 420           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 421                                            to_next, n_left_to_next,
 422                                            bi0, next0);
 423         }
 424
 425       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 426     }
 427   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 428                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 429                                pkts_to_client);
 430   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 431                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 432                                pkts_to_server);
 433   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 434                                DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
 435   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 436                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 437                                pkts_no_interface_address);
 438   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 439                                DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
 440   return from_frame->n_vectors;
 441 }
 442
 443 /* *INDENT-OFF* */
 444 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
 445   .function = dhcp_proxy_to_server_input,
 446   .name = "dhcp-proxy-to-server",
 447   /* Takes a vector of packets. */
 448   .vector_size = sizeof (u32),
 449
 450   .n_errors = DHCP_PROXY_N_ERROR,
 451   .error_strings = dhcp_proxy_error_strings,
 452
 453   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 454   .next_nodes = {
 455 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 456     foreach_dhcp_proxy_to_server_input_next
 457 #undef _
 458   },
 459
 460   .format_buffer = format_dhcp_proxy_header_with_length,
 461   .format_trace = format_dhcp_proxy_trace,
 462 #if 0
 463   .unformat_buffer = unformat_dhcp_proxy_header,
 464 #endif
 465 };
 466 /* *INDENT-ON* */
 467
 468 static uword
 469 dhcp_proxy_to_client_input (vlib_main_t * vm,
 470                             vlib_node_runtime_t * node,
 471                             vlib_frame_t * from_frame)
 472 {
 473   u32 n_left_from, *from;
 474   ethernet_main_t *em = vnet_get_ethernet_main ();
 475   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 476   vnet_main_t *vnm = vnet_get_main ();
 477   ip4_main_t *im = &ip4_main;
 478
 479   from = vlib_frame_vector_args (from_frame);
 480   n_left_from = from_frame->n_vectors;
 481
 482   while (n_left_from > 0)
 483     {
 484       u32 bi0;
 485       vlib_buffer_t *b0;
 486       udp_header_t *u0;
 487       dhcp_header_t *h0;
 488       ip4_header_t *ip0 = 0;
 489       ip4_address_t *ia0 = 0;
 490       u32 old0, new0;
 491       ip_csum_t sum0;
 492       ethernet_interface_t *ei0;
 493       ethernet_header_t *mac0;
 494       vnet_hw_interface_t *hi0;
 495       vlib_frame_t *f0;
 496       u32 *to_next0;
 497       u32 sw_if_index = ~0;
 498       vnet_sw_interface_t *si0;
 499       u32 error0 = (u32) ~ 0;
 500       vnet_sw_interface_t *swif;
 501       u32 fib_index;
 502       dhcp_proxy_t *proxy;
 503       dhcp_server_t *server;
 504       u32 original_sw_if_index = (u32) ~ 0;
 505       ip4_address_t relay_addr = {
 506         .as_u32 = 0,
 507       };
 508
 509       bi0 = from[0];
 510       from += 1;
 511       n_left_from -= 1;
 512
 513       b0 = vlib_get_buffer (vm, bi0);
 514       h0 = vlib_buffer_get_current (b0);
 515
 516       /*
 517        * udp_local hands us the DHCP header, need udp hdr,
 518        * ip hdr to relay to client
 519        */
 520       vlib_buffer_advance (b0, -(sizeof (*u0)));
 521       u0 = vlib_buffer_get_current (b0);
 522
 523       vlib_buffer_advance (b0, -(sizeof (*ip0)));
 524       ip0 = vlib_buffer_get_current (b0);
 525
 526       /* Consumed by dhcp client code? */
 527       if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 528         continue;
 529
 530       if (1 /* dpm->insert_option_82 */ )
 531         {
 532           /* linearize needed to "unclone" and scan options */
 533           int space_left = vlib_buffer_chain_linearize (vm, b0);
 534           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || space_left < 0)
 535             {
 536               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 537               goto drop_packet;
 538             }
 539
 540           dhcp_option_t *o = h0->options, *end =
 541             (void *) vlib_buffer_get_tail (b0);
 542
 543           /* Parse through TLVs looking for option 82.
 544              The circuit-ID is the FIB number we need
 545              to track down the client-facing interface */
 546
 547           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 548             {
 549               if (o->option == 82)
 550                 {
 551                   u32 vss_exist = 0;
 552                   u32 vss_ctrl = 0;
 553                   dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
 554                   dhcp_option_t *subend =
 555                     (dhcp_option_t *) (o->data + o->length);
 556                   while (sub->option != DHCP_PACKET_OPTION_END
 557                          && sub < subend)
 558                     {
 559                       /* If this is one of ours, it will have
 560                          total length 12, circuit-id suboption type,
 561                          and the sw_if_index */
 562                       if (sub->option == 1 && sub->length == 4)
 563                         {
 564                           sw_if_index = ((sub->data[0] << 24) |
 565                                          (sub->data[1] << 16) |
 566                                          (sub->data[2] << 8) |
 567                                          (sub->data[3]));
 568                         }
 569                       else if (sub->option == 5 && sub->length == 4)
 570                         {
 571                           relay_addr.as_u8[0] = sub->data[0];
 572                           relay_addr.as_u8[1] = sub->data[1];
 573                           relay_addr.as_u8[2] = sub->data[2];
 574                           relay_addr.as_u8[3] = sub->data[3];
 575                         }
 576                       else if (sub->option == 151 &&
 577                                sub->length == 7 && sub->data[0] == 1)
 578                         vss_exist = 1;
 579                       else if (sub->option == 152 && sub->length == 0)
 580                         vss_ctrl = 1;
 581                       sub = (dhcp_option_t *) (sub->data + sub->length);
 582                     }
 583                   if (vss_ctrl && vss_exist)
 584                     vlib_node_increment_counter
 585                       (vm, dhcp_proxy_to_client_node.index,
 586                        DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 587
 588                 }
 589               o = (dhcp_option_t *) (o->data + o->length);
 590             }
 591         }
 592
 593       if (sw_if_index == (u32) ~ 0)
 594         {
 595           error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 596
 597         drop_packet:
 598           vlib_node_increment_counter (vm, dhcp_proxy_to_client_node.index,
 599                                        error0, 1);
 600           f0 = vlib_get_frame_to_node (vm, dpm->error_drop_node_index);
 601           to_next0 = vlib_frame_vector_args (f0);
 602           to_next0[0] = bi0;
 603           f0->n_vectors = 1;
 604           vlib_put_frame_to_node (vm, dpm->error_drop_node_index, f0);
 605           goto do_trace;
 606         }
 607
 608       if (relay_addr.as_u32 == 0)
 609         {
 610           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 611           goto drop_packet;
 612         }
 613
 614       if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 615         {
 616           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 617           goto drop_packet;
 618         }
 619
 620       fib_index = im->fib_index_by_sw_if_index[sw_if_index];
 621       proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 622
 623       if (PREDICT_FALSE (NULL == proxy))
 624         {
 625           error0 = DHCP_PROXY_ERROR_NO_SERVER;
 626           goto drop_packet;
 627         }
 628
 629       vec_foreach (server, proxy->dhcp_servers)
 630       {
 631         if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
 632           {
 633             goto server_found;
 634           }
 635       }
 636
 637       error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 638       goto drop_packet;
 639
 640     server_found:
 641       vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 642
 643       swif = vnet_get_sw_interface (vnm, sw_if_index);
 644       original_sw_if_index = sw_if_index;
 645       if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 646         sw_if_index = swif->unnumbered_sw_if_index;
 647
 648       ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 649       if (ia0 == 0)
 650         {
 651           error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 652           goto drop_packet;
 653         }
 654
 655       if (relay_addr.as_u32 != ia0->as_u32)
 656         {
 657           error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 658           goto drop_packet;
 659         }
 660
 661       u0->checksum = 0;
 662       u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 663       sum0 = ip0->checksum;
 664       old0 = ip0->dst_address.as_u32;
 665       new0 = 0xFFFFFFFF;
 666       ip0->dst_address.as_u32 = new0;
 667       sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 668                              dst_address /* offset of changed member */ );
 669       ip0->checksum = ip_csum_fold (sum0);
 670
 671       sum0 = ip0->checksum;
 672       old0 = ip0->src_address.as_u32;
 673       new0 = ia0->as_u32;
 674       ip0->src_address.as_u32 = new0;
 675       sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 676                              src_address /* offset of changed member */ );
 677       ip0->checksum = ip_csum_fold (sum0);
 678
 679       vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
 680       si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 681       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 682         vlib_buffer_advance (b0, -4 /* space for VLAN tag */ );
 683
 684       mac0 = vlib_buffer_get_current (b0);
 685
 686       hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 687       ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 688       clib_memcpy (mac0->src_address, ei0->address, sizeof (ei0->address));
 689       clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 690       mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
 691         clib_net_to_host_u16 (0x8100) : clib_net_to_host_u16 (0x0800);
 692
 693       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 694         {
 695           u32 *vlan_tag = (u32 *) (mac0 + 1);
 696           u32 tmp;
 697           tmp = (si0->sub.id << 16) | 0x0800;
 698           *vlan_tag = clib_host_to_net_u32 (tmp);
 699         }
 700
 701       /* $$$ This needs to be rewritten, for sure */
 702       f0 = vlib_get_frame_to_node (vm, hi0->output_node_index);
 703       to_next0 = vlib_frame_vector_args (f0);
 704       to_next0[0] = bi0;
 705       f0->n_vectors = 1;
 706       vlib_put_frame_to_node (vm, hi0->output_node_index, f0);
 707
 708     do_trace:
 709       if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 710         {
 711           dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 712                                                    b0, sizeof (*tr));
 713           tr->which = 1;        /* to client */
 714           tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 715           tr->error = error0;
 716           tr->original_sw_if_index = original_sw_if_index;
 717           tr->sw_if_index = sw_if_index;
 718         }
 719     }
 720
 721   return from_frame->n_vectors;
 722 }
 723
 724 /* *INDENT-OFF* */
 725 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
 726   .function = dhcp_proxy_to_client_input,
 727   .name = "dhcp-proxy-to-client",
 728   /* Takes a vector of packets. */
 729   .vector_size = sizeof (u32),
 730
 731   .n_errors = DHCP_PROXY_N_ERROR,
 732   .error_strings = dhcp_proxy_error_strings,
 733   .format_buffer = format_dhcp_proxy_header_with_length,
 734   .format_trace = format_dhcp_proxy_trace,
 735 #if 0
 736   .unformat_buffer = unformat_dhcp_proxy_header,
 737 #endif
 738 };
 739 /* *INDENT-ON* */
 740
 741 void
 742 dhcp_maybe_register_udp_ports (void)
 743 {
 744   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 745   vlib_main_t *vm = dm->vlib_main;
 746
 747   if (dm->udp_ports_registered)
 748     return;
 749
 750   udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 751                          dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
 752
 753   udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 754                          dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
 755
 756   dm->udp_ports_registered = 1;
 757 }
 758
 759 static clib_error_t *
 760 dhcp4_proxy_init (vlib_main_t * vm)
 761 {
 762   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 763   vlib_node_t *error_drop_node;
 764
 765   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 766   dm->error_drop_node_index = error_drop_node->index;
 767   dm->vlib_main = vm;
 768
 769   return 0;
 770 }
 771
 772
 773 VLIB_INIT_FUNCTION (dhcp4_proxy_init);
 774
 775 int
 776 dhcp4_proxy_set_server (ip46_address_t * addr,
 777                         ip46_address_t * src_addr,
 778                         u32 rx_table_id, u32 server_table_id, int is_del)
 779 {
 780   u32 rx_fib_index = 0;
 781   int rc = 0;
 782
 783   const fib_prefix_t all_1s = {
 784     .fp_len = 32,
 785     .fp_addr.ip4.as_u32 = 0xffffffff,
 786     .fp_proto = FIB_PROTOCOL_IP4,
 787   };
 788
 789   if (ip46_address_is_zero (addr))
 790     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 791
 792   if (ip46_address_is_zero (src_addr))
 793     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 794
 795   dhcp_maybe_register_udp_ports ();
 796
 797   rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
 798                                                     rx_table_id,
 799                                                     FIB_SOURCE_DHCP);
 800
 801   if (is_del)
 802     {
 803       if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
 804                                  addr, server_table_id))
 805         {
 806           fib_table_entry_special_remove (rx_fib_index,
 807                                           &all_1s, FIB_SOURCE_DHCP);
 808           fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 809         }
 810     }
 811   else
 812     {
 813       if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
 814                                  addr, src_addr,
 815                                  rx_fib_index, server_table_id))
 816         {
 817           fib_table_entry_special_add (rx_fib_index,
 818                                        &all_1s,
 819                                        FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
 820           fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 821         }
 822     }
 823   fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 824
 825   return (rc);
 826 }
 827
 828 static clib_error_t *
 829 dhcp4_proxy_set_command_fn (vlib_main_t * vm,
 830                             unformat_input_t * input,
 831                             vlib_cli_command_t * cmd)
 832 {
 833   ip46_address_t server_addr, src_addr;
 834   u32 server_table_id = 0, rx_table_id = 0;
 835   int is_del = 0;
 836   int set_src = 0, set_server = 0;
 837
 838   clib_memset (&server_addr, 0, sizeof (server_addr));
 839   clib_memset (&src_addr, 0, sizeof (src_addr));
 840
 841   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 842     {
 843       if (unformat (input, "server %U",
 844                     unformat_ip4_address, &server_addr.ip4))
 845         set_server = 1;
 846       else if (unformat (input, "server-fib-id %d", &server_table_id))
 847         ;
 848       else if (unformat (input, "rx-fib-id %d", &rx_table_id))
 849         ;
 850       else if (unformat (input, "src-address %U",
 851                          unformat_ip4_address, &src_addr.ip4))
 852         set_src = 1;
 853       else if (unformat (input, "delete") || unformat (input, "del"))
 854         is_del = 1;
 855       else
 856         break;
 857     }
 858
 859   if (is_del || (set_server && set_src))
 860     {
 861       int rv;
 862
 863       rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
 864                                    server_table_id, is_del);
 865       switch (rv)
 866         {
 867         case 0:
 868           return 0;
 869
 870         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 871           return clib_error_return (0, "Invalid server address");
 872
 873         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 874           return clib_error_return (0, "Invalid src address");
 875
 876         case VNET_API_ERROR_NO_SUCH_ENTRY:
 877           return clib_error_return
 878             (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
 879
 880         default:
 881           return clib_error_return (0, "BUG: rv %d", rv);
 882         }
 883     }
 884   else
 885     return clib_error_return (0, "parse error`%U'",
 886                               format_unformat_error, input);
 887 }
 888
 889 /* *INDENT-OFF* */
 890 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 891   .path = "set dhcp proxy",
 892   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 893   .function = dhcp4_proxy_set_command_fn,
 894 };
 895 /* *INDENT-ON* */
 896
 897 static u8 *
 898 format_dhcp4_proxy_server (u8 * s, va_list * args)
 899 {
 900   dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
 901   ip4_fib_t *rx_fib, *server_fib;
 902   dhcp_server_t *server;
 903
 904   if (proxy == 0)
 905     {
 906       s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
 907                   "Servers FIB,Address");
 908       return s;
 909     }
 910
 911   rx_fib = ip4_fib_get (proxy->rx_fib_index);
 912
 913   s = format (s, "%=14u%=16U",
 914               rx_fib->table_id,
 915               format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
 916
 917   vec_foreach (server, proxy->dhcp_servers)
 918   {
 919     server_fib = ip4_fib_get (server->server_fib_index);
 920     s = format (s, "%u,%U  ",
 921                 server_fib->table_id,
 922                 format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
 923   }
 924   return s;
 925 }
 926
 927 static int
 928 dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
 929 {
 930   vlib_main_t *vm = ctx;
 931
 932   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
 933
 934   return (1);
 935 }
 936
 937 static clib_error_t *
 938 dhcp4_proxy_show_command_fn (vlib_main_t * vm,
 939                              unformat_input_t * input,
 940                              vlib_cli_command_t * cmd)
 941 {
 942   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
 943                    NULL /* header line */ );
 944
 945   dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
 946
 947   return (NULL);
 948 }
 949
 950 /* *INDENT-OFF* */
 951 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
 952   .path = "show dhcp proxy",
 953   .short_help = "Display dhcp proxy server info",
 954   .function = dhcp4_proxy_show_command_fn,
 955 };
 956 /* *INDENT-ON* */
 957
 958 static clib_error_t *
 959 dhcp_option_82_vss_fn (vlib_main_t * vm,
 960                        unformat_input_t * input, vlib_cli_command_t * cmd)
 961 {
 962   u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
 963   u32 oui = 0, fib_id = 0, tbl_id = ~0;
 964   u8 *vpn_ascii_id = 0;
 965
 966   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 967     {
 968       if (unformat (input, "table %d", &tbl_id))
 969         ;
 970       else if (unformat (input, "oui %d", &oui))
 971         vss_type = VSS_TYPE_VPN_ID;
 972       else if (unformat (input, "vpn-id %d", &fib_id))
 973         vss_type = VSS_TYPE_VPN_ID;
 974       else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
 975         vss_type = VSS_TYPE_ASCII;
 976       else if (unformat (input, "delete") || unformat (input, "del"))
 977         is_del = 1;
 978       else
 979         break;
 980     }
 981
 982   if (tbl_id == ~0)
 983     return clib_error_return (0, "no table ID specified.");
 984
 985   int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
 986                                vpn_ascii_id, oui, fib_id, is_del);
 987   switch (rv)
 988     {
 989     case 0:
 990       return 0;
 991     case VNET_API_ERROR_NO_SUCH_ENTRY:
 992       return clib_error_return (0,
 993                                 "option 82 vss for table %d not found in in pool.",
 994                                 tbl_id);
 995     default:
 996       return clib_error_return (0, "BUG: rv %d", rv);
 997
 998     }
 999 }
1000
1001 /* *INDENT-OFF* */
1002 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1003   .path = "set dhcp option-82 vss",
1004   .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1005   .function = dhcp_option_82_vss_fn,
1006 };
1007 /* *INDENT-ON* */
1008
1009 static clib_error_t *
1010 dhcp_vss_show_command_fn (vlib_main_t * vm,
1011                           unformat_input_t * input, vlib_cli_command_t * cmd)
1012 {
1013   dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1014
1015   return (NULL);
1016 }
1017
1018 /* *INDENT-OFF* */
1019 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1020   .path = "show dhcp vss",
1021   .short_help = "show dhcp VSS",
1022   .function = dhcp_vss_show_command_fn,
1023 };
1024 /* *INDENT-ON* */
1025
1026 static clib_error_t *
1027 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1028                                         unformat_input_t * input,
1029                                         vlib_cli_command_t * cmd)
1030 {
1031   vnet_main_t *vnm = vnet_get_main ();
1032   u32 sw_if_index0 = 0, sw_if_index;
1033   vnet_sw_interface_t *swif;
1034   ip4_address_t *ia0;
1035
1036   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1037     {
1038
1039       if (unformat (input, "%U",
1040                     unformat_vnet_sw_interface, vnm, &sw_if_index0))
1041         {
1042           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1043           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1044             swif->unnumbered_sw_if_index : sw_if_index0;
1045           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1046           if (ia0)
1047             {
1048               vlib_cli_output (vm, "%=20s%=20s", "interface",
1049                                "source IP address");
1050
1051               vlib_cli_output (vm, "%=20U%=20U",
1052                                format_vnet_sw_if_index_name,
1053                                vnm, sw_if_index0, format_ip4_address, ia0);
1054             }
1055           else
1056             vlib_cli_output (vm, "%=34s %=20U",
1057                              "No IPv4 address configured on",
1058                              format_vnet_sw_if_index_name, vnm, sw_if_index);
1059         }
1060       else
1061         break;
1062     }
1063
1064   return 0;
1065 }
1066
1067 /* *INDENT-OFF* */
1068 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1069   .path = "show dhcp option-82-address interface",
1070   .short_help = "show dhcp option-82-address interface <interface>",
1071   .function = dhcp_option_82_address_show_command_fn,
1072 };
1073 /* *INDENT-ON* */
1074
1075 /*
1076  * fd.io coding-style-patch-verification: ON
1077  *
1078  * Local Variables:
1079  * eval: (c-set-style "gnu")
1080  * End:
1081  */