src/vnet/dhcp/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/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 "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 #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   /* 0 => to server, 1 => to client */
  44   int which;
  45   ip4_address_t trace_ip4_address;
  46   u32 error;
  47   u32 sw_if_index;
  48   u32 original_sw_if_index;
  49 } dhcp_proxy_trace_t;
  50
  51 #define VPP_DHCP_OPTION82_SUB1_SIZE   6
  52 #define VPP_DHCP_OPTION82_SUB5_SIZE   6
  53 #define VPP_DHCP_OPTION82_VSS_SIZE    12
  54 #define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
  55                                 VPP_DHCP_OPTION82_SUB5_SIZE + \
  56                                 VPP_DHCP_OPTION82_VSS_SIZE +3)
  57
  58 vlib_node_registration_t dhcp_proxy_to_server_node;
  59 vlib_node_registration_t dhcp_proxy_to_client_node;
  60
  61 dhcp_proxy_main_t dhcp_proxy_main;
  62
  63 u8 * format_dhcp_proxy_trace (u8 * s, va_list * args)
  64 {
  65   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  66   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  67   dhcp_proxy_trace_t * t = va_arg (*args, dhcp_proxy_trace_t *);
  68
  69   if (t->which == 0)
  70     s = format (s, "DHCP proxy: sent to server %U\n",
  71                 format_ip4_address, &t->trace_ip4_address, t->error);
  72   else
  73     s = format (s, "DHCP proxy: broadcast to client from %U\n",
  74                 format_ip4_address, &t->trace_ip4_address);
  75
  76   if (t->error != (u32)~0)
  77     s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
  78
  79   s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
  80               t->original_sw_if_index, t->sw_if_index);
  81
  82   return s;
  83 }
  84
  85 u8 * format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
  86 {
  87   dhcp_header_t * h = va_arg (*args, dhcp_header_t *);
  88   u32 max_header_bytes = va_arg (*args, u32);
  89   u32 header_bytes;
  90
  91   header_bytes = sizeof (h[0]);
  92   if (max_header_bytes != 0 && header_bytes > max_header_bytes)
  93     return format (s, "dhcp header truncated");
  94
  95   s = format (s, "DHCP Proxy");
  96
  97   return s;
  98 }
  99
 100 static inline vss_info *
 101 dhcp_get_vss_info (dhcp_proxy_main_t *dm,
 102                    u32 rx_fib_index)
 103 {
 104   vss_info *v;
 105
 106   if (vec_len(dm->vss_index_by_rx_fib_index) <= rx_fib_index ||
 107       dm->vss_index_by_rx_fib_index[rx_fib_index] == ~0)
 108   {
 109       v = NULL;
 110   }
 111   else
 112   {
 113       v = pool_elt_at_index (dm->vss,
 114                              dm->vss_index_by_rx_fib_index[rx_fib_index]);
 115   }
 116
 117   return (v);
 118 }
 119
 120 static inline dhcp_server_t *
 121 dhcp_get_server (dhcp_proxy_main_t *dm,
 122                  u32 rx_fib_index)
 123 {
 124   dhcp_server_t *s = NULL;
 125
 126   if (vec_len(dm->dhcp_server_index_by_rx_fib_index) > rx_fib_index &&
 127       dm->dhcp_server_index_by_rx_fib_index[rx_fib_index] != ~0)
 128   {
 129       s = pool_elt_at_index (dm->dhcp_servers,
 130                              dm->dhcp_server_index_by_rx_fib_index[rx_fib_index]);
 131   }
 132
 133   return (s);
 134 }
 135
 136 static uword
 137 dhcp_proxy_to_server_input (vlib_main_t * vm,
 138                             vlib_node_runtime_t * node,
 139                             vlib_frame_t * from_frame)
 140 {
 141   u32 n_left_from, next_index, * from, * to_next;
 142   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
 143   from = vlib_frame_vector_args (from_frame);
 144   n_left_from = from_frame->n_vectors;
 145   u32 pkts_to_server=0, pkts_to_client=0, pkts_no_server=0;
 146   u32 pkts_no_interface_address=0;
 147   u32 pkts_too_big=0;
 148   ip4_main_t * im = &ip4_main;
 149
 150   next_index = node->cached_next_index;
 151
 152   while (n_left_from > 0)
 153     {
 154       u32 n_left_to_next;
 155
 156       vlib_get_next_frame (vm, node, next_index,
 157                            to_next, n_left_to_next);
 158
 159       while (n_left_from > 0 && n_left_to_next > 0)
 160         {
 161           u32 bi0;
 162           vlib_buffer_t * b0;
 163           udp_header_t * u0;
 164           dhcp_header_t * h0;
 165           ip4_header_t * ip0;
 166           u32 next0;
 167           u32 old0, new0;
 168           ip_csum_t sum0;
 169           u32 error0 = (u32) ~0;
 170           u32 sw_if_index = 0;
 171           u32 original_sw_if_index = 0;
 172           u8  *end = NULL;
 173           u32 fib_index;
 174           dhcp_server_t * server;
 175           u32 rx_sw_if_index;
 176           dhcp_option_t *o;
 177           u32 len = 0;
 178           vlib_buffer_free_list_t *fl;
 179
 180           bi0 = from[0];
 181           to_next[0] = bi0;
 182           from += 1;
 183           to_next += 1;
 184           n_left_from -= 1;
 185           n_left_to_next -= 1;
 186
 187           b0 = vlib_get_buffer (vm, bi0);
 188
 189           h0 = vlib_buffer_get_current (b0);
 190
 191           /*
 192            * udp_local hands us the DHCP header, need udp hdr,
 193            * ip hdr to relay to server
 194            */
 195           vlib_buffer_advance (b0, -(sizeof(*u0)));
 196           u0 = vlib_buffer_get_current (b0);
 197
 198           /* This blows. Return traffic has src_port = 67, dst_port = 67 */
 199           if (u0->src_port == clib_net_to_host_u16(UDP_DST_PORT_dhcp_to_server))
 200             {
 201               vlib_buffer_advance (b0, sizeof(*u0));
 202               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
 203               error0 = 0;
 204               pkts_to_client++;
 205               goto do_enqueue;
 206             }
 207
 208           rx_sw_if_index = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 209
 210           fib_index = im->fib_index_by_sw_if_index [rx_sw_if_index];
 211           server = dhcp_get_server(dpm, fib_index);
 212
 213           if (PREDICT_FALSE (NULL == server))
 214             {
 215               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 216               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 217               pkts_no_server++;
 218               goto do_trace;
 219             }
 220
 221           vlib_buffer_advance (b0, -(sizeof(*ip0)));
 222           ip0 = vlib_buffer_get_current (b0);
 223
 224           /* disable UDP checksum */
 225           u0->checksum = 0;
 226           sum0 = ip0->checksum;
 227           old0 = ip0->dst_address.as_u32;
 228           new0 = server->dhcp_server.as_u32;
 229           ip0->dst_address.as_u32 = server->dhcp_server.as_u32;
 230           sum0 = ip_csum_update (sum0, old0, new0,
 231                                 ip4_header_t /* structure */,
 232                                 dst_address /* changed member */);
 233           ip0->checksum = ip_csum_fold (sum0);
 234
 235           sum0 = ip0->checksum;
 236           old0 = ip0->src_address.as_u32;
 237           new0 = server->dhcp_src_address.as_u32;
 238           ip0->src_address.as_u32 = new0;
 239           sum0 = ip_csum_update (sum0, old0, new0,
 240                                 ip4_header_t /* structure */,
 241                                 src_address /* changed member */);
 242           ip0->checksum = ip_csum_fold (sum0);
 243
 244           /* Send to DHCP server via the configured FIB */
 245           vnet_buffer(b0)->sw_if_index[VLIB_TX] =
 246             server->server_fib_index;
 247
 248           h0->gateway_ip_address.as_u32 = server->dhcp_src_address.as_u32;
 249           pkts_to_server++;
 250
 251           o = (dhcp_option_t *) h0->options;
 252
 253           fib_index = im->fib_index_by_sw_if_index
 254               [vnet_buffer(b0)->sw_if_index[VLIB_RX]];
 255
 256           end = b0->data + b0->current_data + b0->current_length;
 257           /* TLVs are not performance-friendly... */
 258           while  (o->option != 0xFF /* end of options */ && (u8 *)o < end)
 259               o = (dhcp_option_t *) (((uword) o) + (o->length + 2));
 260
 261           fl = vlib_buffer_get_free_list (vm, b0->free_list_index);
 262           // start write at (option*)o, some packets have padding
 263           if (((u8 *)o - (u8 *)b0->data + VPP_DHCP_OPTION82_SIZE) > fl->n_data_bytes)
 264           {
 265               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 266               pkts_too_big++;
 267               goto do_trace;
 268           }
 269
 270           if ((o->option == 0xFF)  && ((u8 *)o <= end))
 271           {
 272               vnet_main_t *vnm = vnet_get_main();
 273               u16 old_l0, new_l0;
 274               ip4_address_t _ia0, * ia0 = &_ia0;
 275               vss_info *vss;
 276               vnet_sw_interface_t *swif;
 277               sw_if_index = 0;
 278               original_sw_if_index = 0;
 279
 280               original_sw_if_index = sw_if_index =
 281                   vnet_buffer(b0)->sw_if_index[VLIB_RX];
 282               swif = vnet_get_sw_interface (vnm, sw_if_index);
 283               if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 284                   sw_if_index = swif->unnumbered_sw_if_index;
 285
 286               /*
 287                * Get the first ip4 address on the [client-side]
 288                * RX interface, if not unnumbered. otherwise use
 289                * the loopback interface's ip address.
 290                */
 291               ia0 = ip4_interface_first_address(&ip4_main, sw_if_index, 0);
 292
 293               if (ia0 == 0)
 294               {
 295                   error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 296                   next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 297                   pkts_no_interface_address++;
 298                   goto do_trace;
 299               }
 300
 301               /* Add option 82 */
 302               o->option = 82;   /* option 82 */
 303               o->length = 12;   /* 12 octets to follow */
 304               o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
 305               o->data[1] = 4;   /* length of suboption */
 306               o->data[2] = (original_sw_if_index >> 24) & 0xFF;
 307               o->data[3] = (original_sw_if_index >> 16) & 0xFF;
 308               o->data[4] = (original_sw_if_index >> 8)  & 0xFF;
 309               o->data[5] = (original_sw_if_index >> 0)  & 0xFF;
 310               o->data[6] = 5; /* suboption 5 (client RX intfc address) */
 311               o->data[7] = 4; /* length 4 */
 312               o->data[8] = ia0->as_u8[0];
 313               o->data[9] = ia0->as_u8[1];
 314               o->data[10] = ia0->as_u8[2];
 315               o->data[11] = ia0->as_u8[3];
 316               o->data[12] = 0xFF;
 317
 318               vss = dhcp_get_vss_info (dpm, fib_index);
 319               if (NULL != vss)
 320               {
 321                   u32 opt82_fib_id=0, opt82_oui=0;
 322
 323                   opt82_oui =  vss->vpn_id.oui;
 324                   opt82_fib_id =  vss->vpn_id.fib_id;
 325
 326                   o->data[12] = 151; /* vss suboption */
 327                   if (255 == opt82_fib_id) {
 328                       o->data[13] = 1;   /* length */
 329                       o->data[14] = 255;   /* vss option type */
 330                       o->data[15] = 152; /* vss control suboption */
 331                       o->data[16] = 0;   /* length */
 332                       /* and a new "end-of-options" option (0xff) */
 333                       o->data[17] = 0xFF;
 334                       o->length += 5;
 335                   } else {
 336                       o->data[13] = 8;   /* length */
 337                       o->data[14] = 1;   /* vss option type */
 338                       o->data[15] = (opt82_oui >> 16) & 0xff;
 339                       o->data[16] = (opt82_oui >> 8) & 0xff;
 340                       o->data[17] = (opt82_oui ) & 0xff;
 341                       o->data[18] = (opt82_fib_id >> 24) & 0xff;
 342                       o->data[19] = (opt82_fib_id >> 16) & 0xff;
 343                       o->data[20] = (opt82_fib_id >> 8) & 0xff;
 344                       o->data[21] = (opt82_fib_id) & 0xff;
 345                       o->data[22] = 152; /* vss control suboption */
 346                       o->data[23] = 0;   /* length */
 347
 348                       /* and a new "end-of-options" option (0xff) */
 349                       o->data[24] = 0xFF;
 350                       o->length += 12;
 351                   }
 352               }
 353
 354               len = o->length + 3;
 355               b0->current_length += len;
 356               /* Fix IP header length and checksum */
 357               old_l0 = ip0->length;
 358               new_l0 = clib_net_to_host_u16 (old_l0);
 359               new_l0 += len;
 360               new_l0 = clib_host_to_net_u16 (new_l0);
 361               ip0->length = new_l0;
 362               sum0 = ip0->checksum;
 363               sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
 364                                      length /* changed member */);
 365               ip0->checksum = ip_csum_fold (sum0);
 366
 367               /* Fix UDP length */
 368               new_l0 = clib_net_to_host_u16 (u0->length);
 369               new_l0 += len;
 370               u0->length = clib_host_to_net_u16 (new_l0);
 371           } else {
 372               vlib_node_increment_counter
 373                   (vm, dhcp_proxy_to_server_node.index,
 374                    DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
 375           }
 376
 377           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 378
 379         do_trace:
 380           if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
 381             {
 382                dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 383                                                         b0, sizeof (*tr));
 384                tr->which = 0; /* to server */
 385                tr->error = error0;
 386                tr->original_sw_if_index = original_sw_if_index;
 387                tr->sw_if_index = sw_if_index;
 388                if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 389                  tr->trace_ip4_address.as_u32 = server->dhcp_server.as_u32;
 390             }
 391
 392         do_enqueue:
 393           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 394                                            to_next, n_left_to_next,
 395                                            bi0, next0);
 396         }
 397
 398       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 399     }
 400
 401   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 402                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 403                                pkts_to_client);
 404   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 405                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 406                                pkts_to_server);
 407   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 408                                DHCP_PROXY_ERROR_NO_SERVER,
 409                                pkts_no_server);
 410   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 411                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 412                                pkts_no_interface_address);
 413  vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 414                               DHCP_PROXY_ERROR_PKT_TOO_BIG,
 415                               pkts_too_big);
 416   return from_frame->n_vectors;
 417 }
 418
 419 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node) = {
 420   .function = dhcp_proxy_to_server_input,
 421   .name = "dhcp-proxy-to-server",
 422   /* Takes a vector of packets. */
 423   .vector_size = sizeof (u32),
 424
 425   .n_errors = DHCP_PROXY_N_ERROR,
 426   .error_strings = dhcp_proxy_error_strings,
 427
 428   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 429   .next_nodes = {
 430 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 431     foreach_dhcp_proxy_to_server_input_next
 432 #undef _
 433   },
 434
 435   .format_buffer = format_dhcp_proxy_header_with_length,
 436   .format_trace = format_dhcp_proxy_trace,
 437 #if 0
 438   .unformat_buffer = unformat_dhcp_proxy_header,
 439 #endif
 440 };
 441
 442 static uword
 443 dhcp_proxy_to_client_input (vlib_main_t * vm,
 444                             vlib_node_runtime_t * node,
 445                             vlib_frame_t * from_frame)
 446 {
 447   u32 n_left_from, * from;
 448   ethernet_main_t *em = ethernet_get_main (vm);
 449   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
 450   vnet_main_t * vnm = vnet_get_main();
 451   ip4_main_t * im = &ip4_main;
 452
 453   from = vlib_frame_vector_args (from_frame);
 454   n_left_from = from_frame->n_vectors;
 455
 456   while (n_left_from > 0)
 457     {
 458       u32 bi0;
 459       vlib_buffer_t * b0;
 460       udp_header_t * u0;
 461       dhcp_header_t * h0;
 462       ip4_header_t * ip0 = 0;
 463       ip4_address_t * ia0 = 0;
 464       u32 old0, new0;
 465       ip_csum_t sum0;
 466       ethernet_interface_t *ei0;
 467       ethernet_header_t *mac0;
 468       vnet_hw_interface_t *hi0;
 469       vlib_frame_t *f0;
 470       u32 * to_next0;
 471       u32 sw_if_index = ~0;
 472       vnet_sw_interface_t *si0;
 473       u32 error0 = (u32)~0;
 474       vnet_sw_interface_t *swif;
 475       u32 fib_index;
 476       dhcp_server_t * server;
 477       u32 original_sw_if_index = (u32) ~0;
 478       ip4_address_t relay_addr = {
 479           .as_u32 = 0,
 480       };
 481
 482       bi0 = from[0];
 483       from += 1;
 484       n_left_from -= 1;
 485
 486       b0 = vlib_get_buffer (vm, bi0);
 487       h0 = vlib_buffer_get_current (b0);
 488
 489       /*
 490        * udp_local hands us the DHCP header, need udp hdr,
 491        * ip hdr to relay to client
 492        */
 493       vlib_buffer_advance (b0, -(sizeof(*u0)));
 494       u0 = vlib_buffer_get_current (b0);
 495
 496       vlib_buffer_advance (b0, -(sizeof(*ip0)));
 497       ip0 = vlib_buffer_get_current (b0);
 498
 499       /* Consumed by dhcp client code? */
 500       if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 501           continue;
 502
 503       if (1 /* dpm->insert_option_82 */)
 504         {
 505           dhcp_option_t *o = (dhcp_option_t *) h0->options;
 506           dhcp_option_t *sub;
 507
 508           /* Parse through TLVs looking for option 82.
 509              The circuit-ID is the FIB number we need
 510              to track down the client-facing interface */
 511
 512           while (o->option != 0xFF /* end of options */ &&
 513                  (u8 *) o < (b0->data + b0->current_data + b0->current_length))
 514             {
 515               if (o->option == 82)
 516                 {
 517                     u32 vss_exist = 0;
 518                     u32 vss_ctrl = 0;
 519                     sub = (dhcp_option_t *) &o->data[0];
 520                     while (sub->option != 0xFF /* end of options */ &&
 521                            (u8 *) sub < (u8 *)(o + o->length)) {
 522                         /* If this is one of ours, it will have
 523                            total length 12, circuit-id suboption type,
 524                            and the sw_if_index */
 525                         if (sub->option == 1 && sub->length == 4)
 526                           {
 527                             sw_if_index = ((sub->data[0] << 24) |
 528                                            (sub->data[1] << 16) |
 529                                            (sub->data[2] << 8)  |
 530                                            (sub->data[3]));
 531                           }
 532                         else if (sub->option == 5 && sub->length == 4)
 533                           {
 534                               relay_addr.as_u8[0] = sub->data[0];
 535                               relay_addr.as_u8[1] = sub->data[1];
 536                               relay_addr.as_u8[2] = sub->data[2];
 537                               relay_addr.as_u8[3] = sub->data[3];
 538                           }
 539                         else if (sub->option == 151 &&
 540                                  sub->length == 7 &&
 541                                  sub->data[0] == 1)
 542                             vss_exist = 1;
 543                         else if (sub->option == 152 && sub->length == 0)
 544                             vss_ctrl = 1;
 545                         sub = (dhcp_option_t *)
 546                           (((uword) sub) + (sub->length + 2));
 547                     }
 548                     if (vss_ctrl && vss_exist)
 549                       vlib_node_increment_counter
 550                         (vm, dhcp_proxy_to_client_node.index,
 551                          DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 552
 553                 }
 554               o = (dhcp_option_t *) (((uword) o) + (o->length + 2));
 555             }
 556         }
 557
 558       if (sw_if_index == (u32)~0)
 559         {
 560           error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 561
 562         drop_packet:
 563           vlib_node_increment_counter (vm, dhcp_proxy_to_client_node.index,
 564                                        error0, 1);
 565           f0 = vlib_get_frame_to_node (vm, dpm->error_drop_node_index);
 566           to_next0 = vlib_frame_vector_args (f0);
 567           to_next0[0] = bi0;
 568           f0->n_vectors = 1;
 569           vlib_put_frame_to_node (vm, dpm->error_drop_node_index, f0);
 570           goto do_trace;
 571         }
 572
 573       if (relay_addr.as_u32 == 0)
 574         {
 575           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 576           goto drop_packet;
 577         }
 578
 579       if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 580         {
 581           error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 582           goto drop_packet;
 583         }
 584
 585       fib_index = im->fib_index_by_sw_if_index [sw_if_index];
 586       server = dhcp_get_server(dpm, fib_index);
 587
 588       if (PREDICT_FALSE (NULL == server))
 589         {
 590           error0 = DHCP_PROXY_ERROR_NO_SERVER;
 591           goto drop_packet;
 592         }
 593
 594       if (ip0->src_address.as_u32 != server->dhcp_server.as_u32)
 595         {
 596           error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 597           goto drop_packet;
 598         }
 599
 600       vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 601
 602       swif = vnet_get_sw_interface (vnm, sw_if_index);
 603       original_sw_if_index = sw_if_index;
 604       if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 605           sw_if_index = swif->unnumbered_sw_if_index;
 606
 607       ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 608       if (ia0 == 0)
 609         {
 610           error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 611           goto drop_packet;
 612         }
 613
 614       if (relay_addr.as_u32 != ia0->as_u32)
 615         {
 616           error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 617           goto drop_packet;
 618         }
 619
 620       u0->checksum = 0;
 621       u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 622       sum0 = ip0->checksum;
 623       old0 = ip0->dst_address.as_u32;
 624       new0 = 0xFFFFFFFF;
 625       ip0->dst_address.as_u32 = new0;
 626       sum0 = ip_csum_update (sum0, old0, new0,
 627                             ip4_header_t /* structure */,
 628                             dst_address /* offset of changed member */);
 629       ip0->checksum = ip_csum_fold (sum0);
 630
 631       sum0 = ip0->checksum;
 632       old0 = ip0->src_address.as_u32;
 633       new0 = ia0->as_u32;
 634       ip0->src_address.as_u32 = new0;
 635       sum0 = ip_csum_update (sum0, old0, new0,
 636                             ip4_header_t /* structure */,
 637                             src_address /* offset of changed member */);
 638       ip0->checksum = ip_csum_fold (sum0);
 639
 640       vlib_buffer_advance (b0, -(sizeof(ethernet_header_t)));
 641       si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 642       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 643           vlib_buffer_advance (b0, -4 /* space for VLAN tag */);
 644
 645       mac0 = vlib_buffer_get_current (b0);
 646
 647       hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 648       ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 649       clib_memcpy (mac0->src_address, ei0->address, sizeof (ei0->address));
 650       memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 651       mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
 652         clib_net_to_host_u16(0x8100) : clib_net_to_host_u16 (0x0800);
 653
 654       if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 655         {
 656           u32 * vlan_tag = (u32 *)(mac0+1);
 657           u32 tmp;
 658           tmp = (si0->sub.id << 16) | 0x0800;
 659           *vlan_tag = clib_host_to_net_u32 (tmp);
 660         }
 661
 662       /* $$$ This needs to be rewritten, for sure */
 663       f0 = vlib_get_frame_to_node (vm, hi0->output_node_index);
 664       to_next0 = vlib_frame_vector_args (f0);
 665       to_next0[0] = bi0;
 666       f0->n_vectors = 1;
 667       vlib_put_frame_to_node (vm, hi0->output_node_index, f0);
 668
 669     do_trace:
 670       if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
 671         {
 672           dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 673                                                    b0, sizeof (*tr));
 674           tr->which = 1; /* to client */
 675           tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 676           tr->error = error0;
 677           tr->original_sw_if_index = original_sw_if_index;
 678           tr->sw_if_index = sw_if_index;
 679         }
 680     }
 681   return from_frame->n_vectors;
 682 }
 683
 684 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node) = {
 685   .function = dhcp_proxy_to_client_input,
 686   .name = "dhcp-proxy-to-client",
 687   /* Takes a vector of packets. */
 688   .vector_size = sizeof (u32),
 689
 690   .n_errors = DHCP_PROXY_N_ERROR,
 691   .error_strings = dhcp_proxy_error_strings,
 692   .format_buffer = format_dhcp_proxy_header_with_length,
 693   .format_trace = format_dhcp_proxy_trace,
 694 #if 0
 695   .unformat_buffer = unformat_dhcp_proxy_header,
 696 #endif
 697 };
 698
 699 clib_error_t * dhcp_proxy_init (vlib_main_t * vm)
 700 {
 701   dhcp_proxy_main_t * dm = &dhcp_proxy_main;
 702   vlib_node_t * error_drop_node;
 703   dhcp_server_t * server;
 704
 705   dm->vlib_main = vm;
 706   dm->vnet_main = vnet_get_main();
 707   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 708   dm->error_drop_node_index = error_drop_node->index;
 709
 710   dm->vss_index_by_rx_fib_index = NULL;
 711
 712   udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 713                          dhcp_proxy_to_client_node.index, 1 /* is_ip4 */);
 714
 715   udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 716                          dhcp_proxy_to_server_node.index, 1 /* is_ip4 */);
 717
 718   /* Create the default server, don't mark it valid */
 719   pool_get (dm->dhcp_servers, server);
 720   memset (server, 0, sizeof (*server));
 721
 722   return 0;
 723 }
 724
 725 VLIB_INIT_FUNCTION (dhcp_proxy_init);
 726
 727 int dhcp_proxy_set_server (ip4_address_t *addr,
 728                            ip4_address_t *src_address,
 729                            u32 rx_fib_id,
 730                            u32 server_fib_id,
 731                            int is_del)
 732 {
 733   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
 734   dhcp_server_t * server = 0;
 735   u32 server_index = 0;
 736   u32 rx_fib_index = 0;
 737
 738   const fib_prefix_t all_1s =
 739   {
 740       .fp_len = 32,
 741       .fp_addr.ip4.as_u32 = 0xffffffff,
 742       .fp_proto = FIB_PROTOCOL_IP4,
 743   };
 744
 745   if (addr->as_u32 == 0)
 746     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 747
 748   if (src_address->as_u32 == 0)
 749     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 750
 751   rx_fib_index = fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4,
 752                                                    rx_fib_id);
 753
 754   if (is_del)
 755     {
 756       if (rx_fib_index >= vec_len(dpm->dhcp_server_index_by_rx_fib_index))
 757         return VNET_API_ERROR_NO_SUCH_ENTRY;
 758
 759       server_index = dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index];
 760
 761       if (server_index == ~0)
 762         return VNET_API_ERROR_NO_SUCH_ENTRY;
 763
 764       /* Use the default server again.  */
 765       dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index] = ~0;
 766       server = pool_elt_at_index (dpm->dhcp_servers, server_index);
 767
 768       fib_table_entry_special_remove(rx_fib_index,
 769                                      &all_1s,
 770                                      FIB_SOURCE_DHCP);
 771       fib_table_unlock (rx_fib_index,
 772                         FIB_PROTOCOL_IP4);
 773       fib_table_unlock (server->server_fib_index,
 774                         FIB_PROTOCOL_IP4);
 775
 776       memset (server, 0, sizeof (*server));
 777       pool_put (dpm->dhcp_servers, server);
 778       return 0;
 779     }
 780   else
 781   {
 782       vec_validate_init_empty(dpm->dhcp_server_index_by_rx_fib_index,
 783                               rx_fib_index,
 784                               ~0);
 785
 786       pool_get (dpm->dhcp_servers, server);
 787
 788       server->dhcp_server.as_u32 = addr->as_u32;
 789       server->dhcp_src_address.as_u32 = src_address->as_u32;
 790
 791       fib_table_entry_special_add(rx_fib_index,
 792                                   &all_1s,
 793                                   FIB_SOURCE_DHCP,
 794                                   FIB_ENTRY_FLAG_LOCAL,
 795                                   ADJ_INDEX_INVALID);
 796       fib_table_lock (rx_fib_index,
 797                       FIB_PROTOCOL_IP4);
 798
 799       server->server_fib_index =
 800           fib_table_find_or_create_and_lock(FIB_PROTOCOL_IP4,
 801                                             server_fib_id);
 802
 803       vec_validate_init_empty (dpm->dhcp_server_index_by_rx_fib_index,
 804                                rx_fib_index,
 805                                ~0);
 806       dpm->dhcp_server_index_by_rx_fib_index[rx_fib_index] =
 807           server - dpm->dhcp_servers;
 808   }
 809
 810   fib_table_unlock (rx_fib_index,
 811                     FIB_PROTOCOL_IP4);
 812
 813   return 0;
 814 }
 815
 816 static clib_error_t *
 817 dhcp_proxy_set_command_fn (vlib_main_t * vm,
 818                            unformat_input_t * input,
 819                            vlib_cli_command_t * cmd)
 820 {
 821   ip4_address_t server_addr, src_addr;
 822   u32 server_fib_id = 0, rx_fib_id = 0;
 823   int is_del = 0;
 824   int set_src = 0, set_server = 0;
 825
 826   while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
 827     {
 828       if (unformat (input, "server %U",
 829                     unformat_ip4_address, &server_addr))
 830         set_server = 1;
 831       else if (unformat (input, "server-fib-id %d", &server_fib_id))
 832         ;
 833       else if (unformat (input, "rx-fib-id %d", &rx_fib_id))
 834         ;
 835       else if (unformat(input, "src-address %U",
 836                         unformat_ip4_address, &src_addr))
 837         set_src = 1;
 838       else if (unformat (input, "delete") ||
 839                unformat (input, "del"))
 840         is_del = 1;
 841       else
 842         break;
 843     }
 844
 845   if (is_del || (set_server && set_src))
 846     {
 847       int rv;
 848
 849       rv = dhcp_proxy_set_server (&server_addr, &src_addr, rx_fib_id,
 850                                   server_fib_id, is_del);
 851       switch (rv)
 852         {
 853         case 0:
 854           return 0;
 855
 856         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 857           return clib_error_return (0, "Invalid server address");
 858
 859         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 860           return clib_error_return (0, "Invalid src address");
 861
 862         case VNET_API_ERROR_NO_SUCH_INNER_FIB:
 863           return clib_error_return (0, "No such rx fib id %d", rx_fib_id);
 864
 865         case VNET_API_ERROR_NO_SUCH_FIB:
 866           return clib_error_return (0, "No such server fib id %d",
 867                                     server_fib_id);
 868
 869         case VNET_API_ERROR_NO_SUCH_ENTRY:
 870           return clib_error_return
 871             (0, "Fib id %d: no per-fib DHCP server configured", rx_fib_id);
 872
 873         default:
 874           return clib_error_return (0, "BUG: rv %d", rv);
 875         }
 876     }
 877   else
 878     return clib_error_return (0, "parse error`%U'",
 879                               format_unformat_error, input);
 880 }
 881
 882 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 883   .path = "set dhcp proxy",
 884   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 885   .function = dhcp_proxy_set_command_fn,
 886 };
 887
 888 u8 * format_dhcp_proxy_server (u8 * s, va_list * args)
 889 {
 890   dhcp_proxy_main_t * dm = va_arg (*args, dhcp_proxy_main_t *);
 891   dhcp_server_t * server = va_arg (*args, dhcp_server_t *);
 892   u32 rx_fib_index = va_arg (*args, u32);
 893   ip4_fib_t * rx_fib, * server_fib;
 894   u32 server_fib_id = ~0, rx_fib_id = ~0;
 895
 896   if (dm == 0)
 897     {
 898       s = format (s, "%=16s%=16s%=14s%=14s", "Server", "Src Address",
 899                   "Server FIB", "RX FIB");
 900       return s;
 901     }
 902
 903   server_fib = ip4_fib_get(server->server_fib_index);
 904
 905   if (server_fib)
 906     server_fib_id = server_fib->table_id;
 907
 908   rx_fib = ip4_fib_get(rx_fib_index);
 909
 910   if (rx_fib)
 911     rx_fib_id = rx_fib->table_id;
 912
 913   s = format (s, "%=16U%=16U%=14u%=14u",
 914               format_ip4_address, &server->dhcp_server,
 915               format_ip4_address, &server->dhcp_src_address,
 916               server_fib_id, rx_fib_id);
 917   return s;
 918 }
 919
 920 static clib_error_t *
 921 dhcp_proxy_show_command_fn (vlib_main_t * vm,
 922                             unformat_input_t * input,
 923                             vlib_cli_command_t * cmd)
 924 {
 925   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
 926   dhcp_server_t * server;
 927   u32 server_index, i;
 928
 929   vlib_cli_output (vm, "%U", format_dhcp_proxy_server, 0 /* header line */,
 930                    0, 0);
 931
 932   vec_foreach_index (i, dpm->dhcp_server_index_by_rx_fib_index)
 933   {
 934       server_index = dpm->dhcp_server_index_by_rx_fib_index[i];
 935       if (~0 == server_index)
 936           continue;
 937
 938       server = pool_elt_at_index (dpm->dhcp_servers, server_index);
 939
 940       vlib_cli_output (vm, "%U", format_dhcp_proxy_server, dpm,
 941                        server, i);
 942     }
 943
 944   return 0;
 945 }
 946
 947 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
 948   .path = "show dhcp proxy",
 949   .short_help = "Display dhcp proxy server info",
 950   .function = dhcp_proxy_show_command_fn,
 951 };
 952
 953 void
 954 dhcp_proxy_dump (void *opaque,
 955                  u32 context)
 956 {
 957   dhcp_proxy_main_t * dpm = &dhcp_proxy_main;
 958   ip4_fib_t *s_fib, *r_fib;
 959   dhcp_server_t * server;
 960   u32 server_index, i;
 961   vss_info *v;
 962
 963   vec_foreach_index (i, dpm->dhcp_server_index_by_rx_fib_index)
 964   {
 965       server_index = dpm->dhcp_server_index_by_rx_fib_index[i];
 966       if (~0 == server_index)
 967           continue;
 968
 969       server = pool_elt_at_index (dpm->dhcp_servers, server_index);
 970       v = dhcp_get_vss_info(dpm, i);
 971
 972       ip46_address_t src_addr = {
 973           .ip4 = server->dhcp_src_address,
 974       };
 975       ip46_address_t server_addr = {
 976           .ip4 = server->dhcp_server,
 977       };
 978
 979       s_fib = ip4_fib_get(server->server_fib_index);
 980       r_fib = ip4_fib_get(i);
 981
 982       dhcp_send_details(opaque,
 983                         context,
 984                         &server_addr,
 985                         &src_addr,
 986                         s_fib->table_id,
 987                         r_fib->table_id,
 988                         (v ? v->vpn_id.fib_id : 0),
 989                         (v ? v->vpn_id.oui : 0));
 990   }
 991 }
 992
 993 int dhcp_proxy_set_option82_vss(u32 tbl_id,
 994                                 u32 oui,
 995                                 u32 fib_id,
 996                                 int is_del)
 997 {
 998   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 999   vss_info *v = NULL;
1000   u32  rx_fib_index;
1001   int rc = 0;
1002
1003   rx_fib_index = ip4_fib_table_find_or_create_and_lock(tbl_id);
1004   v = dhcp_get_vss_info(dm, rx_fib_index);
1005
1006   if (NULL != v)
1007   {
1008       if (is_del)
1009       {
1010           /* release the lock held on the table when the VSS
1011            * info was created */
1012           fib_table_unlock (rx_fib_index,
1013                             FIB_PROTOCOL_IP4);
1014
1015           pool_put (dm->vss, v);
1016           dm->vss_index_by_rx_fib_index[rx_fib_index] = ~0;
1017       }
1018       else
1019       {
1020           /* this is a modify */
1021           v->vpn_id.fib_id = fib_id;
1022           v->vpn_id.oui = oui;
1023       }
1024   }
1025   else
1026   {
1027       if (is_del)
1028           rc = VNET_API_ERROR_NO_SUCH_ENTRY;
1029       else
1030       {
1031           /* create a new entry */
1032           vec_validate_init_empty(dm->vss_index_by_rx_fib_index,
1033                                   rx_fib_index, ~0);
1034
1035           /* hold a lock on the table whilst the VSS info exist */
1036           fib_table_lock (rx_fib_index,
1037                           FIB_PROTOCOL_IP4);
1038
1039           pool_get (dm->vss, v);
1040           v->vpn_id.fib_id = fib_id;
1041           v->vpn_id.oui = oui;
1042           dm->vss_index_by_rx_fib_index[rx_fib_index] = v - dm->vss;
1043       }
1044   }
1045
1046   /* Release the lock taken during the create_or_lock at the start */
1047   fib_table_unlock (rx_fib_index,
1048                     FIB_PROTOCOL_IP4);
1049
1050   return (rc);
1051 }
1052
1053 static clib_error_t *
1054 dhcp_option_82_vss_fn (vlib_main_t * vm,
1055                         unformat_input_t * input,
1056                         vlib_cli_command_t * cmd)
1057 {
1058   int is_del = 0, got_new_vpn_id=0;
1059   u32 oui=0, fib_id=0, tbl_id=~0;
1060
1061
1062   while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
1063     {
1064
1065       if (unformat(input, "delete") || unformat(input, "del"))
1066           is_del = 1;
1067       else if (unformat (input, "oui %d", &oui))
1068           got_new_vpn_id = 1;
1069       else if (unformat (input, "vpn-id %d", &fib_id))
1070           got_new_vpn_id = 1;
1071       else if (unformat (input, "table %d", &tbl_id))
1072           got_new_vpn_id = 1;
1073       else
1074           break;
1075   }
1076   if (tbl_id == ~0)
1077       return clib_error_return (0, "no table ID specified.");
1078
1079   if (is_del || got_new_vpn_id)
1080     {
1081       int rv;
1082       rv = dhcp_proxy_set_option82_vss(tbl_id, oui, fib_id, is_del);
1083       switch (rv)
1084         {
1085         case 0:
1086             return 0;
1087
1088         case VNET_API_ERROR_NO_SUCH_FIB:
1089             return clib_error_return (0, "option 82 vss(oui:%d, vpn-id:%d) not found in table %d",
1090                                       oui, fib_id, tbl_id);
1091
1092         case VNET_API_ERROR_NO_SUCH_ENTRY:
1093             return clib_error_return (0, "option 82 vss for table %d not found in in pool.",
1094                                       tbl_id);
1095         default:
1096           return clib_error_return (0, "BUG: rv %d", rv);
1097         }
1098     }
1099   else
1100       return clib_error_return (0, "parse error`%U'",
1101                                 format_unformat_error, input);
1102 }
1103
1104 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1105   .path = "set dhcp option-82 vss",
1106   .short_help = "set dhcp option-82 vss [del] table <table id> oui <oui> vpn-id <vpn-id>",
1107   .function = dhcp_option_82_vss_fn,
1108 };
1109
1110
1111 static clib_error_t *
1112 dhcp_vss_show_command_fn (vlib_main_t * vm,
1113                           unformat_input_t * input,
1114                           vlib_cli_command_t * cmd)
1115
1116 {
1117   dhcp_proxy_main_t * dm = &dhcp_proxy_main;
1118   ip4_fib_t *fib;
1119   u32 *fib_index;
1120   vss_info *v;
1121
1122   vlib_cli_output (vm, "%=9s%=11s%=12s","Table", "OUI", "VPN-ID");
1123   pool_foreach (fib_index, dm->vss_index_by_rx_fib_index,
1124   ({
1125       fib = ip4_fib_get (*fib_index);
1126       v = pool_elt_at_index (dm->vss, *fib_index);
1127
1128       vlib_cli_output (vm, "%=6d%=6d%=12d",
1129                        fib->table_id,
1130                        v->vpn_id.oui,
1131                        v->vpn_id.fib_id);
1132   }));
1133
1134   return 0;
1135 }
1136
1137 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1138   .path = "show dhcp vss",
1139   .short_help = "show dhcp VSS",
1140   .function = dhcp_vss_show_command_fn,
1141 };
1142
1143 static clib_error_t *
1144 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1145                                 unformat_input_t * input,
1146                                 vlib_cli_command_t * cmd)
1147
1148 {
1149   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
1150   vnet_main_t *vnm = vnet_get_main();
1151   u32 sw_if_index0=0, sw_if_index;
1152   ip4_address_t *ia0;
1153   vnet_sw_interface_t *swif;
1154
1155   while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
1156     {
1157
1158       if (unformat(input, "%U",
1159                    unformat_vnet_sw_interface, dm->vnet_main, &sw_if_index0))
1160         {
1161           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1162           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1163             swif->unnumbered_sw_if_index : sw_if_index0;
1164           ia0 = ip4_interface_first_address(&ip4_main, sw_if_index, 0);
1165           if (ia0)
1166             {
1167               vlib_cli_output (vm, "%=20s%=20s", "interface",
1168                                "source IP address");
1169
1170               vlib_cli_output (vm, "%=20U%=20U",
1171                                format_vnet_sw_if_index_name,
1172                                dm->vnet_main, sw_if_index0,
1173                                format_ip4_address, ia0);
1174             }
1175           else
1176             vlib_cli_output (vm, "%=34s %=20U",
1177                              "No IPv4 address configured on",
1178                              format_vnet_sw_if_index_name,
1179                              dm->vnet_main, sw_if_index);
1180         }
1181       else
1182         break;
1183     }
1184
1185   return 0;
1186 }
1187
1188 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1189   .path = "show dhcp option-82-address interface",
1190   .short_help = "show dhcp option-82-address interface <interface>",
1191   .function = dhcp_option_82_address_show_command_fn,
1192 };