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           if (!vlib_buffer_chain_linearize (vm, b0))
 185             {
 186               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 187               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 188               pkts_too_big++;
 189               goto do_trace;
 190             }
 191           space_left = vlib_buffer_space_left_at_end (vm, b0);
 192           /* cant parse chains...
 193            * and we need some space for option 82*/
 194           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
 195               space_left < VPP_DHCP_OPTION82_SIZE)
 196             {
 197               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 198               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 199               pkts_too_big++;
 200               goto do_trace;
 201             }
 202
 203           server = &proxy->dhcp_servers[0];
 204           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 205           ip0 = vlib_buffer_get_current (b0);
 206
 207           /* disable UDP checksum */
 208           u0->checksum = 0;
 209           sum0 = ip0->checksum;
 210           old0 = ip0->dst_address.as_u32;
 211           new0 = server->dhcp_server.ip4.as_u32;
 212           ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 213           sum0 = ip_csum_update (sum0, old0, new0,
 214                                  ip4_header_t /* structure */ ,
 215                                  dst_address /* changed member */ );
 216           ip0->checksum = ip_csum_fold (sum0);
 217
 218           sum0 = ip0->checksum;
 219           old0 = ip0->src_address.as_u32;
 220           new0 = proxy->dhcp_src_address.ip4.as_u32;
 221           ip0->src_address.as_u32 = new0;
 222           sum0 = ip_csum_update (sum0, old0, new0,
 223                                  ip4_header_t /* structure */ ,
 224                                  src_address /* changed member */ );
 225           ip0->checksum = ip_csum_fold (sum0);
 226
 227           /* Send to DHCP server via the configured FIB */
 228           vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
 229
 230           h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
 231           pkts_to_server++;
 232
 233           o = h0->options;
 234           end = (void *) vlib_buffer_get_tail (b0);
 235
 236           /* TLVs are not performance-friendly... */
 237           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 238             {
 239               if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
 240                 {
 241                   if (DHCP_PACKET_DISCOVER == o->data[0])
 242                     {
 243                       is_discover = 1;
 244                     }
 245                 }
 246               o = (dhcp_option_t *) (o->data + o->length);
 247             }
 248
 249           if (o->option == DHCP_PACKET_OPTION_END && o <= end)
 250             {
 251               vnet_main_t *vnm = vnet_get_main ();
 252               u16 old_l0, new_l0;
 253               ip4_address_t _ia0, *ia0 = &_ia0;
 254               dhcp_vss_t *vss;
 255               vnet_sw_interface_t *swif;
 256
 257               original_sw_if_index = sw_if_index =
 258                 vnet_buffer (b0)->sw_if_index[VLIB_RX];
 259               swif = vnet_get_sw_interface (vnm, sw_if_index);
 260               if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 261                 sw_if_index = swif->unnumbered_sw_if_index;
 262
 263               /*
 264                * Get the first ip4 address on the [client-side]
 265                * RX interface, if not unnumbered. otherwise use
 266                * the loopback interface's ip address.
 267                */
 268               ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 269
 270               if (ia0 == 0)
 271                 {
 272                   error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 273                   next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 274                   pkts_no_interface_address++;
 275                   goto do_trace;
 276                 }
 277
 278               /* Add option 82 */
 279               o->option = 82;   /* option 82 */
 280               o->length = 12;   /* 12 octets to follow */
 281               o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
 282               o->data[1] = 4;   /* length of suboption */
 283               u32 *o_ifid = (u32 *) & o->data[2];
 284               *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
 285               o->data[6] = 5;   /* suboption 5 (client RX intfc address) */
 286               o->data[7] = 4;   /* length 4 */
 287               u32 *o_addr = (u32 *) & o->data[8];
 288               *o_addr = ia0->as_u32;
 289               o->data[12] = DHCP_PACKET_OPTION_END;
 290
 291               vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
 292               if (vss)
 293                 {
 294                   u32 id_len;   /* length of VPN ID */
 295
 296                   if (vss->vss_type == VSS_TYPE_VPN_ID)
 297                     {
 298                       id_len = sizeof (vss->vpn_id);    /* vpn_id is 7 bytes */
 299                       memcpy (&o->data[15], vss->vpn_id, id_len);
 300                     }
 301                   else if (vss->vss_type == VSS_TYPE_ASCII)
 302                     {
 303                       id_len = vec_len (vss->vpn_ascii_id);
 304                       memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
 305                     }
 306                   else          /* must be VSS_TYPE_DEFAULT, no VPN ID */
 307                     id_len = 0;
 308
 309                   o->data[12] = 151;    /* vss suboption */
 310                   o->data[13] = id_len + 1;     /* length: vss_type + id_len */
 311                   o->data[14] = vss->vss_type;  /* vss option type */
 312                   o->data[15 + id_len] = 152;   /* vss control suboption */
 313                   o->data[16 + id_len] = 0;     /* length */
 314                   o->data[17 + id_len] = DHCP_PACKET_OPTION_END;        /* "end-of-options" (0xFF) */
 315                   /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
 316                   o->length += id_len + 5;
 317                 }
 318
 319               len = o->length + 3;
 320               b0->current_length += len;
 321               /* Fix IP header length and checksum */
 322               old_l0 = ip0->length;
 323               new_l0 = clib_net_to_host_u16 (old_l0);
 324               new_l0 += len;
 325               new_l0 = clib_host_to_net_u16 (new_l0);
 326               ip0->length = new_l0;
 327               sum0 = ip0->checksum;
 328               sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
 329                                      length /* changed member */ );
 330               ip0->checksum = ip_csum_fold (sum0);
 331
 332               /* Fix UDP length */
 333               new_l0 = clib_net_to_host_u16 (u0->length);
 334               new_l0 += len;
 335               u0->length = clib_host_to_net_u16 (new_l0);
 336             }
 337           else
 338             {
 339               vlib_node_increment_counter
 340                 (vm, dhcp_proxy_to_server_node.index,
 341                  DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
 342             }
 343
 344           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 345
 346           /*
 347            * If we have multiple servers configured and this is the
 348            * client's discover message, then send copies to each of
 349            * those servers
 350            */
 351           if (is_discover && vec_len (proxy->dhcp_servers) > 1)
 352             {
 353               u32 ii;
 354
 355               for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
 356                 {
 357                   vlib_buffer_t *c0;
 358                   u32 ci0;
 359
 360                   c0 = vlib_buffer_copy (vm, b0);
 361                   VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
 362                   ci0 = vlib_get_buffer_index (vm, c0);
 363                   server = &proxy->dhcp_servers[ii];
 364
 365                   ip0 = vlib_buffer_get_current (c0);
 366
 367                   sum0 = ip0->checksum;
 368                   old0 = ip0->dst_address.as_u32;
 369                   new0 = server->dhcp_server.ip4.as_u32;
 370                   ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 371                   sum0 = ip_csum_update (sum0, old0, new0,
 372                                          ip4_header_t /* structure */ ,
 373                                          dst_address /* changed member */ );
 374                   ip0->checksum = ip_csum_fold (sum0);
 375
 376                   to_next[0] = ci0;
 377                   to_next += 1;
 378                   n_left_to_next -= 1;
 379
 380                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 381                                                    to_next, n_left_to_next,
 382                                                    ci0, next0);
 383
 384                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 385                     {
 386                       dhcp_proxy_trace_t *tr;
 387
 388                       vlib_buffer_copy_trace_flag (vm, b0, ci0);
 389                       tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
 390                       tr->which = 0;    /* to server */
 391                       tr->error = error0;
 392                       tr->original_sw_if_index = original_sw_if_index;
 393                       tr->sw_if_index = sw_if_index;
 394                       if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 395                         tr->trace_ip4_address.as_u32 =
 396                           server->dhcp_server.ip4.as_u32;
 397                     }
 398
 399                   if (PREDICT_FALSE (0 == n_left_to_next))
 400                     {
 401                       vlib_put_next_frame (vm, node, next_index,
 402                                            n_left_to_next);
 403                       vlib_get_next_frame (vm, node, next_index,
 404                                            to_next, n_left_to_next);
 405                     }
 406                 }
 407             }
 408         do_trace:
 409           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 410             {
 411               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 412                                                        b0, sizeof (*tr));
 413               tr->which = 0;    /* to server */
 414               tr->error = error0;
 415               tr->original_sw_if_index = original_sw_if_index;
 416               tr->sw_if_index = sw_if_index;
 417               if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 418                 tr->trace_ip4_address.as_u32 =
 419                   proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
 420             }
 421
 422         do_enqueue:
 423           to_next[0] = bi0;
 424           to_next += 1;
 425           n_left_to_next -= 1;
 426
 427           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 428                                            to_next, n_left_to_next,
 429                                            bi0, next0);
 430         }
 431
 432       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 433     }
 434   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 435                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 436                                pkts_to_client);
 437   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 438                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 439                                pkts_to_server);
 440   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 441                                DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
 442   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 443                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 444                                pkts_no_interface_address);
 445   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 446                                DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
 447   return from_frame->n_vectors;
 448 }
 449
 450 /* *INDENT-OFF* */
 451 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
 452   .function = dhcp_proxy_to_server_input,
 453   .name = "dhcp-proxy-to-server",
 454   /* Takes a vector of packets. */
 455   .vector_size = sizeof (u32),
 456
 457   .n_errors = DHCP_PROXY_N_ERROR,
 458   .error_strings = dhcp_proxy_error_strings,
 459
 460   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 461   .next_nodes = {
 462 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 463     foreach_dhcp_proxy_to_server_input_next
 464 #undef _
 465   },
 466
 467   .format_buffer = format_dhcp_proxy_header_with_length,
 468   .format_trace = format_dhcp_proxy_trace,
 469 #if 0
 470   .unformat_buffer = unformat_dhcp_proxy_header,
 471 #endif
 472 };
 473 /* *INDENT-ON* */
 474
 475 static uword
 476 dhcp_proxy_to_client_input (vlib_main_t * vm,
 477                             vlib_node_runtime_t * node,
 478                             vlib_frame_t * from_frame)
 479 {
 480   u32 n_left_from, *from;
 481   ethernet_main_t *em = vnet_get_ethernet_main ();
 482   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 483   vnet_main_t *vnm = vnet_get_main ();
 484   ip4_main_t *im = &ip4_main;
 485
 486   from = vlib_frame_vector_args (from_frame);
 487   n_left_from = from_frame->n_vectors;
 488
 489   while (n_left_from > 0)
 490     {
 491       u32 bi0;
 492       vlib_buffer_t *b0;
 493       udp_header_t *u0;
 494       dhcp_header_t *h0;
 495       ip4_header_t *ip0 = 0;
 496       ip4_address_t *ia0 = 0;
 497       u32 old0, new0;
 498       ip_csum_t sum0;
 499       ethernet_interface_t *ei0;
 500       ethernet_header_t *mac0;
 501       vnet_hw_interface_t *hi0;
 502       vlib_frame_t *f0;
 503       u32 *to_next0;
 504       u32 sw_if_index = ~0;
 505       vnet_sw_interface_t *si0;
 506       u32 error0 = (u32) ~ 0;
 507       vnet_sw_interface_t *swif;
 508       u32 fib_index;
 509       dhcp_proxy_t *proxy;
 510       dhcp_server_t *server;
 511       u32 original_sw_if_index = (u32) ~ 0;
 512       ip4_address_t relay_addr = {
 513         .as_u32 = 0,
 514       };
 515
 516       bi0 = from[0];
 517       from += 1;
 518       n_left_from -= 1;
 519
 520       b0 = vlib_get_buffer (vm, bi0);
 521       h0 = vlib_buffer_get_current (b0);
 522
 523       /*
 524        * udp_local hands us the DHCP header, need udp hdr,
 525        * ip hdr to relay to client
 526        */
 527       vlib_buffer_advance (b0, -(sizeof (*u0)));
 528       u0 = vlib_buffer_get_current (b0);
 529
 530       vlib_buffer_advance (b0, -(sizeof (*ip0)));
 531       ip0 = vlib_buffer_get_current (b0);
 532
 533       /* Consumed by dhcp client code? */
 534       if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 535         continue;
 536
 537       if (1 /* dpm->insert_option_82 */ )
 538         {
 539           /* linearize needed to "unclone" and scan options */
 540           int rv = vlib_buffer_chain_linearize (vm, b0);
 541           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
 542             {
 543               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 544               goto drop_packet;
 545             }
 546
 547           dhcp_option_t *o = h0->options, *end =
 548             (void *) vlib_buffer_get_tail (b0);
 549
 550           /* Parse through TLVs looking for option 82.
 551              The circuit-ID is the FIB number we need
 552              to track down the client-facing interface */
 553
 554           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 555             {
 556               if (o->option == 82)
 557                 {
 558                   u32 vss_exist = 0;
 559                   u32 vss_ctrl = 0;
 560                   dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
 561                   dhcp_option_t *subend =
 562                     (dhcp_option_t *) (o->data + o->length);
 563                   while (sub->option != DHCP_PACKET_OPTION_END
 564                          && sub < subend)
 565                     {
 566                       /* If this is one of ours, it will have
 567                          total length 12, circuit-id suboption type,
 568                          and the sw_if_index */
 569                       if (sub->option == 1 && sub->length == 4)
 570                         {
 571                           sw_if_index = ((sub->data[0] << 24) |
 572                                          (sub->data[1] << 16) |
 573                                          (sub->data[2] << 8) |
 574                                          (sub->data[3]));
 575                         }
 576                       else if (sub->option == 5 && sub->length == 4)
 577                         {
 578                           relay_addr.as_u8[0] = sub->data[0];
 579                           relay_addr.as_u8[1] = sub->data[1];
 580                           relay_addr.as_u8[2] = sub->data[2];
 581                           relay_addr.as_u8[3] = sub->data[3];
 582                         }
 583                       else if (sub->option == 151 &&
 584                                sub->length == 7 && sub->data[0] == 1)
 585                         vss_exist = 1;
 586                       else if (sub->option == 152 && sub->length == 0)
 587                         vss_ctrl = 1;
 588                       sub = (dhcp_option_t *) (sub->data + sub->length);
 589                     }
 590                   if (vss_ctrl && vss_exist)
 591                     vlib_node_increment_counter
 592                       (vm, dhcp_proxy_to_client_node.index,
 593                        DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 594
 595                 }
 596               o = (dhcp_option_t *) (o->data + o->length);
 597             }
 598         }
 599
 600       if (sw_if_index == (u32) ~ 0)
 601         {
 602           error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 603
 604         drop_packet:
 605           vlib_node_increment_counter (vm, dhcp_proxy_to_client_node.index,
 606                                        error0, 1);
 607           f0 = vlib_get_frame_to_node (vm, dpm->error_drop_node_index);
 608           to_next0 = vlib_frame_vector_args (f0);
 609           to_next0[0] = bi0;
 610           f0->n_vectors = 1;
 611           vlib_put_frame_to_node (vm, dpm->error_drop_node_index, f0);
 612           goto do_trace;
 613         }
 614
 615       if (relay_addr.as_u32 == 0)
 616         {
 617           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 618           goto drop_packet;
 619         }
 620
 621       if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 622         {
 623           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 624           goto drop_packet;
 625         }
 626
 627       fib_index = im->fib_index_by_sw_if_index[sw_if_index];
 628       proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 629
 630       if (PREDICT_FALSE (NULL == proxy))
 631         {
 632           error0 = DHCP_PROXY_ERROR_NO_SERVER;
 633           goto drop_packet;
 634         }
 635
 636       vec_foreach (server, proxy->dhcp_servers)
 637       {
 638         if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
 639           {
 640             goto server_found;
 641           }
 642       }
 643
 644       error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 645       goto drop_packet;
 646
 647     server_found:
 648       vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 649
 650       swif = vnet_get_sw_interface (vnm, sw_if_index);
 651       original_sw_if_index = sw_if_index;
 652       if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 653         sw_if_index = swif->unnumbered_sw_if_index;
 654
 655       ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 656       if (ia0 == 0)
 657         {
 658           error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 659           goto drop_packet;
 660         }
 661
 662       if (relay_addr.as_u32 != ia0->as_u32)
 663         {
 664           error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 665           goto drop_packet;
 666         }
 667
 668       u0->checksum = 0;
 669       u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 670       sum0 = ip0->checksum;
 671       old0 = ip0->dst_address.as_u32;
 672       new0 = 0xFFFFFFFF;
 673       ip0->dst_address.as_u32 = new0;
 674       sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 675                              dst_address /* offset of changed member */ );
 676       ip0->checksum = ip_csum_fold (sum0);
 677
 678       sum0 = ip0->checksum;
 679       old0 = ip0->src_address.as_u32;
 680       new0 = ia0->as_u32;
 681       ip0->src_address.as_u32 = new0;
 682       sum0 = ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 683                              src_address /* offset of changed member */ );
 684       ip0->checksum = ip_csum_fold (sum0);
 685
 686       vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
 687       si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 688       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 689         vlib_buffer_advance (b0, -4 /* space for VLAN tag */ );
 690
 691       mac0 = vlib_buffer_get_current (b0);
 692
 693       hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 694       ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 695       clib_memcpy (mac0->src_address, ei0->address, sizeof (ei0->address));
 696       clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 697       mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
 698         clib_net_to_host_u16 (0x8100) : clib_net_to_host_u16 (0x0800);
 699
 700       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 701         {
 702           u32 *vlan_tag = (u32 *) (mac0 + 1);
 703           u32 tmp;
 704           tmp = (si0->sub.id << 16) | 0x0800;
 705           *vlan_tag = clib_host_to_net_u32 (tmp);
 706         }
 707
 708       /* $$$ This needs to be rewritten, for sure */
 709       f0 = vlib_get_frame_to_node (vm, hi0->output_node_index);
 710       to_next0 = vlib_frame_vector_args (f0);
 711       to_next0[0] = bi0;
 712       f0->n_vectors = 1;
 713       vlib_put_frame_to_node (vm, hi0->output_node_index, f0);
 714
 715     do_trace:
 716       if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 717         {
 718           dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 719                                                    b0, sizeof (*tr));
 720           tr->which = 1;        /* to client */
 721           tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 722           tr->error = error0;
 723           tr->original_sw_if_index = original_sw_if_index;
 724           tr->sw_if_index = sw_if_index;
 725         }
 726     }
 727
 728   return from_frame->n_vectors;
 729 }
 730
 731 /* *INDENT-OFF* */
 732 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
 733   .function = dhcp_proxy_to_client_input,
 734   .name = "dhcp-proxy-to-client",
 735   /* Takes a vector of packets. */
 736   .vector_size = sizeof (u32),
 737
 738   .n_errors = DHCP_PROXY_N_ERROR,
 739   .error_strings = dhcp_proxy_error_strings,
 740   .format_buffer = format_dhcp_proxy_header_with_length,
 741   .format_trace = format_dhcp_proxy_trace,
 742 #if 0
 743   .unformat_buffer = unformat_dhcp_proxy_header,
 744 #endif
 745 };
 746 /* *INDENT-ON* */
 747
 748 void
 749 dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
 750 {
 751   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 752   vlib_main_t *vm = dm->vlib_main;
 753   int port_regs_diff = dm->udp_ports_registered ^ ports;
 754
 755   if (!port_regs_diff)
 756     return;
 757
 758   if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
 759     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 760                            dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
 761
 762   if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
 763     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 764                            dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
 765
 766   dm->udp_ports_registered |= ports;
 767 }
 768
 769 static clib_error_t *
 770 dhcp4_proxy_init (vlib_main_t * vm)
 771 {
 772   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 773   vlib_node_t *error_drop_node;
 774
 775   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 776   dm->error_drop_node_index = error_drop_node->index;
 777   dm->vlib_main = vm;
 778
 779   return 0;
 780 }
 781
 782
 783 VLIB_INIT_FUNCTION (dhcp4_proxy_init);
 784
 785 int
 786 dhcp4_proxy_set_server (ip46_address_t * addr,
 787                         ip46_address_t * src_addr,
 788                         u32 rx_table_id, u32 server_table_id, int is_del)
 789 {
 790   u32 rx_fib_index = 0;
 791   int rc = 0;
 792
 793   const fib_prefix_t all_1s = {
 794     .fp_len = 32,
 795     .fp_addr.ip4.as_u32 = 0xffffffff,
 796     .fp_proto = FIB_PROTOCOL_IP4,
 797   };
 798
 799   if (ip46_address_is_zero (addr))
 800     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 801
 802   if (ip46_address_is_zero (src_addr))
 803     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 804
 805   dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
 806
 807   rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
 808                                                     rx_table_id,
 809                                                     FIB_SOURCE_DHCP);
 810
 811   if (is_del)
 812     {
 813       if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
 814                                  addr, server_table_id))
 815         {
 816           fib_table_entry_special_remove (rx_fib_index,
 817                                           &all_1s, FIB_SOURCE_DHCP);
 818           fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 819         }
 820     }
 821   else
 822     {
 823       if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
 824                                  addr, src_addr,
 825                                  rx_fib_index, server_table_id))
 826         {
 827           fib_table_entry_special_add (rx_fib_index,
 828                                        &all_1s,
 829                                        FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
 830           fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 831         }
 832     }
 833   fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 834
 835   return (rc);
 836 }
 837
 838 static clib_error_t *
 839 dhcp4_proxy_set_command_fn (vlib_main_t * vm,
 840                             unformat_input_t * input,
 841                             vlib_cli_command_t * cmd)
 842 {
 843   ip46_address_t server_addr, src_addr;
 844   u32 server_table_id = 0, rx_table_id = 0;
 845   int is_del = 0;
 846   int set_src = 0, set_server = 0;
 847
 848   clib_memset (&server_addr, 0, sizeof (server_addr));
 849   clib_memset (&src_addr, 0, sizeof (src_addr));
 850
 851   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 852     {
 853       if (unformat (input, "server %U",
 854                     unformat_ip4_address, &server_addr.ip4))
 855         set_server = 1;
 856       else if (unformat (input, "server-fib-id %d", &server_table_id))
 857         ;
 858       else if (unformat (input, "rx-fib-id %d", &rx_table_id))
 859         ;
 860       else if (unformat (input, "src-address %U",
 861                          unformat_ip4_address, &src_addr.ip4))
 862         set_src = 1;
 863       else if (unformat (input, "delete") || unformat (input, "del"))
 864         is_del = 1;
 865       else
 866         break;
 867     }
 868
 869   if (is_del || (set_server && set_src))
 870     {
 871       int rv;
 872
 873       rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
 874                                    server_table_id, is_del);
 875       switch (rv)
 876         {
 877         case 0:
 878           return 0;
 879
 880         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 881           return clib_error_return (0, "Invalid server address");
 882
 883         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 884           return clib_error_return (0, "Invalid src address");
 885
 886         case VNET_API_ERROR_NO_SUCH_ENTRY:
 887           return clib_error_return
 888             (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
 889
 890         default:
 891           return clib_error_return (0, "BUG: rv %d", rv);
 892         }
 893     }
 894   else
 895     return clib_error_return (0, "parse error`%U'",
 896                               format_unformat_error, input);
 897 }
 898
 899 /* *INDENT-OFF* */
 900 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 901   .path = "set dhcp proxy",
 902   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 903   .function = dhcp4_proxy_set_command_fn,
 904 };
 905 /* *INDENT-ON* */
 906
 907 static u8 *
 908 format_dhcp4_proxy_server (u8 * s, va_list * args)
 909 {
 910   dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
 911   ip4_fib_t *rx_fib, *server_fib;
 912   dhcp_server_t *server;
 913
 914   if (proxy == 0)
 915     {
 916       s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
 917                   "Servers FIB,Address");
 918       return s;
 919     }
 920
 921   rx_fib = ip4_fib_get (proxy->rx_fib_index);
 922
 923   s = format (s, "%=14u%=16U",
 924               rx_fib->table_id,
 925               format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
 926
 927   vec_foreach (server, proxy->dhcp_servers)
 928   {
 929     server_fib = ip4_fib_get (server->server_fib_index);
 930     s = format (s, "%u,%U  ",
 931                 server_fib->table_id,
 932                 format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
 933   }
 934   return s;
 935 }
 936
 937 static int
 938 dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
 939 {
 940   vlib_main_t *vm = ctx;
 941
 942   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
 943
 944   return (1);
 945 }
 946
 947 static clib_error_t *
 948 dhcp4_proxy_show_command_fn (vlib_main_t * vm,
 949                              unformat_input_t * input,
 950                              vlib_cli_command_t * cmd)
 951 {
 952   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
 953                    NULL /* header line */ );
 954
 955   dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
 956
 957   return (NULL);
 958 }
 959
 960 /* *INDENT-OFF* */
 961 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
 962   .path = "show dhcp proxy",
 963   .short_help = "Display dhcp proxy server info",
 964   .function = dhcp4_proxy_show_command_fn,
 965 };
 966 /* *INDENT-ON* */
 967
 968 static clib_error_t *
 969 dhcp_option_82_vss_fn (vlib_main_t * vm,
 970                        unformat_input_t * input, vlib_cli_command_t * cmd)
 971 {
 972   u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
 973   u32 oui = 0, fib_id = 0, tbl_id = ~0;
 974   u8 *vpn_ascii_id = 0;
 975
 976   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 977     {
 978       if (unformat (input, "table %d", &tbl_id))
 979         ;
 980       else if (unformat (input, "oui %d", &oui))
 981         vss_type = VSS_TYPE_VPN_ID;
 982       else if (unformat (input, "vpn-id %d", &fib_id))
 983         vss_type = VSS_TYPE_VPN_ID;
 984       else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
 985         vss_type = VSS_TYPE_ASCII;
 986       else if (unformat (input, "delete") || unformat (input, "del"))
 987         is_del = 1;
 988       else
 989         break;
 990     }
 991
 992   if (tbl_id == ~0)
 993     return clib_error_return (0, "no table ID specified.");
 994
 995   int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
 996                                vpn_ascii_id, oui, fib_id, is_del);
 997   switch (rv)
 998     {
 999     case 0:
1000       return 0;
1001     case VNET_API_ERROR_NO_SUCH_ENTRY:
1002       return clib_error_return (0,
1003                                 "option 82 vss for table %d not found in in pool.",
1004                                 tbl_id);
1005     default:
1006       return clib_error_return (0, "BUG: rv %d", rv);
1007
1008     }
1009 }
1010
1011 /* *INDENT-OFF* */
1012 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1013   .path = "set dhcp option-82 vss",
1014   .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1015   .function = dhcp_option_82_vss_fn,
1016 };
1017 /* *INDENT-ON* */
1018
1019 static clib_error_t *
1020 dhcp_vss_show_command_fn (vlib_main_t * vm,
1021                           unformat_input_t * input, vlib_cli_command_t * cmd)
1022 {
1023   dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1024
1025   return (NULL);
1026 }
1027
1028 /* *INDENT-OFF* */
1029 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1030   .path = "show dhcp vss",
1031   .short_help = "show dhcp VSS",
1032   .function = dhcp_vss_show_command_fn,
1033 };
1034 /* *INDENT-ON* */
1035
1036 static clib_error_t *
1037 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1038                                         unformat_input_t * input,
1039                                         vlib_cli_command_t * cmd)
1040 {
1041   vnet_main_t *vnm = vnet_get_main ();
1042   u32 sw_if_index0 = 0, sw_if_index;
1043   vnet_sw_interface_t *swif;
1044   ip4_address_t *ia0;
1045
1046   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1047     {
1048
1049       if (unformat (input, "%U",
1050                     unformat_vnet_sw_interface, vnm, &sw_if_index0))
1051         {
1052           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1053           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1054             swif->unnumbered_sw_if_index : sw_if_index0;
1055           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1056           if (ia0)
1057             {
1058               vlib_cli_output (vm, "%=20s%=20s", "interface",
1059                                "source IP address");
1060
1061               vlib_cli_output (vm, "%=20U%=20U",
1062                                format_vnet_sw_if_index_name,
1063                                vnm, sw_if_index0, format_ip4_address, ia0);
1064             }
1065           else
1066             vlib_cli_output (vm, "%=34s %=20U",
1067                              "No IPv4 address configured on",
1068                              format_vnet_sw_if_index_name, vnm, sw_if_index);
1069         }
1070       else
1071         break;
1072     }
1073
1074   return 0;
1075 }
1076
1077 /* *INDENT-OFF* */
1078 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1079   .path = "show dhcp option-82-address interface",
1080   .short_help = "show dhcp option-82-address interface <interface>",
1081   .function = dhcp_option_82_address_show_command_fn,
1082 };
1083 /* *INDENT-ON* */
1084
1085 /*
1086  * fd.io coding-style-patch-verification: ON
1087  *
1088  * Local Variables:
1089  * eval: (c-set-style "gnu")
1090  * End:
1091  */