src/plugins/dhcp/dhcp4_proxy_node.c

   1 /*
   2  * proxy_node.c: dhcp proxy node processing
   3  *
   4  * Copyright (c) 2013 Cisco and/or its affiliates.
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <vlib/vlib.h>
  19 #include <vnet/pg/pg.h>
  20 #include <dhcp/dhcp_proxy.h>
  21 #include <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 <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
  52   /* enough space for the DHCP header plus some options */
  53   u8 packet_data[2 * sizeof (dhcp_header_t)];
  54 }
  55 dhcp_proxy_trace_t;
  56
  57 #define VPP_DHCP_OPTION82_SUB1_SIZE   6
  58 #define VPP_DHCP_OPTION82_SUB5_SIZE   6
  59 #define VPP_DHCP_OPTION82_VSS_SIZE    12
  60 #define VPP_DHCP_OPTION82_SIZE (VPP_DHCP_OPTION82_SUB1_SIZE + \
  61                                 VPP_DHCP_OPTION82_SUB5_SIZE + \
  62                                 VPP_DHCP_OPTION82_VSS_SIZE +3)
  63
  64 static vlib_node_registration_t dhcp_proxy_to_server_node;
  65 static vlib_node_registration_t dhcp_proxy_to_client_node;
  66
  67 static u8 *
  68 format_dhcp_proxy_trace (u8 * s, va_list * args)
  69 {
  70   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  71   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  72   dhcp_proxy_trace_t *t = va_arg (*args, dhcp_proxy_trace_t *);
  73
  74   if (t->which == 0)
  75     s = format (s, "DHCP proxy: sent to server %U\n",
  76                 format_ip4_address, &t->trace_ip4_address, t->error);
  77   else
  78     s = format (s, "DHCP proxy: broadcast to client from %U\n",
  79                 format_ip4_address, &t->trace_ip4_address);
  80
  81   if (t->error != (u32) ~ 0)
  82     s = format (s, "  error: %s\n", dhcp_proxy_error_strings[t->error]);
  83
  84   s = format (s, "  original_sw_if_index: %d, sw_if_index: %d\n",
  85               t->original_sw_if_index, t->sw_if_index);
  86   s = format (s, "  %U",
  87               format_dhcp_header, t->packet_data, sizeof (t->packet_data));
  88
  89   return s;
  90 }
  91
  92 static u8 *
  93 format_dhcp_proxy_header_with_length (u8 * s, va_list * args)
  94 {
  95   dhcp_header_t *h = va_arg (*args, dhcp_header_t *);
  96   u32 max_header_bytes = va_arg (*args, u32);
  97   u32 header_bytes;
  98
  99   header_bytes = sizeof (h[0]);
 100   if (max_header_bytes != 0 && header_bytes > max_header_bytes)
 101     return format (s, "dhcp header truncated");
 102
 103   s = format (s, "DHCP Proxy");
 104
 105   return s;
 106 }
 107
 108 static uword
 109 dhcp_proxy_to_server_input (vlib_main_t * vm,
 110                             vlib_node_runtime_t * node,
 111                             vlib_frame_t * from_frame)
 112 {
 113   u32 n_left_from, next_index, *from, *to_next;
 114   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 115   from = vlib_frame_vector_args (from_frame);
 116   n_left_from = from_frame->n_vectors;
 117   u32 pkts_to_server = 0, pkts_to_client = 0, pkts_no_server = 0;
 118   u32 pkts_no_interface_address = 0;
 119   u32 pkts_too_big = 0;
 120   ip4_main_t *im = &ip4_main;
 121
 122   next_index = node->cached_next_index;
 123
 124   while (n_left_from > 0)
 125     {
 126       u32 n_left_to_next;
 127
 128       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 129
 130       while (n_left_from > 0 && n_left_to_next > 0)
 131         {
 132           u32 bi0;
 133           vlib_buffer_t *b0;
 134           udp_header_t *u0;
 135           dhcp_header_t *h0;
 136           ip4_header_t *ip0;
 137           u32 next0;
 138           u32 old0, new0;
 139           ip_csum_t sum0;
 140           u32 error0 = (u32) ~ 0;
 141           u32 sw_if_index = 0;
 142           u32 original_sw_if_index = 0;
 143           u32 fib_index;
 144           dhcp_proxy_t *proxy;
 145           dhcp_server_t *server;
 146           u32 rx_sw_if_index;
 147           dhcp_option_t *o, *end;
 148           u32 len = 0;
 149           u8 is_discover = 0;
 150           int space_left;
 151
 152           bi0 = from[0];
 153           from += 1;
 154           n_left_from -= 1;
 155
 156           b0 = vlib_get_buffer (vm, bi0);
 157
 158           h0 = vlib_buffer_get_current (b0);
 159
 160           /*
 161            * udp_local hands us the DHCP header, need udp hdr,
 162            * ip hdr to relay to server
 163            */
 164           vlib_buffer_advance (b0, -(sizeof (*u0)));
 165           u0 = vlib_buffer_get_current (b0);
 166
 167           /* This blows. Return traffic has src_port = 67, dst_port = 67 */
 168           if (u0->src_port ==
 169               clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_server))
 170             {
 171               vlib_buffer_advance (b0, sizeof (*u0));
 172               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_SEND_TO_CLIENT;
 173               error0 = 0;
 174               pkts_to_client++;
 175               goto do_enqueue;
 176             }
 177
 178           rx_sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 179           fib_index = im->fib_index_by_sw_if_index[rx_sw_if_index];
 180           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 181
 182           if (PREDICT_FALSE (NULL == proxy))
 183             {
 184               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 185               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 186               pkts_no_server++;
 187               goto do_trace;
 188             }
 189
 190           if (!vlib_buffer_chain_linearize (vm, b0))
 191             {
 192               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 193               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 194               pkts_too_big++;
 195               goto do_trace;
 196             }
 197           space_left = vlib_buffer_space_left_at_end (vm, b0);
 198           /* cant parse chains...
 199            * and we need some space for option 82*/
 200           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 ||
 201               space_left < VPP_DHCP_OPTION82_SIZE)
 202             {
 203               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 204               next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 205               pkts_too_big++;
 206               goto do_trace;
 207             }
 208
 209           server = &proxy->dhcp_servers[0];
 210           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 211           ip0 = vlib_buffer_get_current (b0);
 212
 213           /* disable UDP checksum */
 214           u0->checksum = 0;
 215           sum0 = ip0->checksum;
 216           old0 = ip0->dst_address.as_u32;
 217           new0 = server->dhcp_server.ip4.as_u32;
 218           ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 219           sum0 = ip_csum_update (sum0, old0, new0,
 220                                  ip4_header_t /* structure */ ,
 221                                  dst_address /* changed member */ );
 222           ip0->checksum = ip_csum_fold (sum0);
 223
 224           sum0 = ip0->checksum;
 225           old0 = ip0->src_address.as_u32;
 226           new0 = proxy->dhcp_src_address.ip4.as_u32;
 227           ip0->src_address.as_u32 = new0;
 228           sum0 = ip_csum_update (sum0, old0, new0,
 229                                  ip4_header_t /* structure */ ,
 230                                  src_address /* changed member */ );
 231           ip0->checksum = ip_csum_fold (sum0);
 232
 233           /* Send to DHCP server via the configured FIB */
 234           vnet_buffer (b0)->sw_if_index[VLIB_TX] = server->server_fib_index;
 235
 236           h0->gateway_ip_address = proxy->dhcp_src_address.ip4;
 237           pkts_to_server++;
 238
 239           o = h0->options;
 240           end = (void *) vlib_buffer_get_tail (b0);
 241
 242           /* TLVs are not performance-friendly... */
 243           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 244             {
 245               if (DHCP_PACKET_OPTION_MSG_TYPE == o->option)
 246                 {
 247                   if (DHCP_PACKET_DISCOVER == o->data[0])
 248                     {
 249                       is_discover = 1;
 250                     }
 251                 }
 252               o = (dhcp_option_t *) (o->data + o->length);
 253             }
 254
 255           if (o->option == DHCP_PACKET_OPTION_END && o <= end)
 256             {
 257               vnet_main_t *vnm = vnet_get_main ();
 258               u16 old_l0, new_l0;
 259               ip4_address_t _ia0, *ia0 = &_ia0;
 260               dhcp_vss_t *vss;
 261               vnet_sw_interface_t *swif;
 262
 263               original_sw_if_index = sw_if_index =
 264                 vnet_buffer (b0)->sw_if_index[VLIB_RX];
 265               swif = vnet_get_sw_interface (vnm, sw_if_index);
 266               if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 267                 sw_if_index = swif->unnumbered_sw_if_index;
 268
 269               /*
 270                * Get the first ip4 address on the [client-side]
 271                * RX interface, if not unnumbered. otherwise use
 272                * the loopback interface's ip address.
 273                */
 274               ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 275
 276               if (ia0 == 0)
 277                 {
 278                   error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 279                   next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_DROP;
 280                   pkts_no_interface_address++;
 281                   goto do_trace;
 282                 }
 283
 284               /* Add option 82 */
 285               o->option = 82;   /* option 82 */
 286               o->length = 12;   /* 12 octets to follow */
 287               o->data[0] = 1;   /* suboption 1, circuit ID (=FIB id) */
 288               o->data[1] = 4;   /* length of suboption */
 289               u32 *o_ifid = (u32 *) & o->data[2];
 290               *o_ifid = clib_host_to_net_u32 (original_sw_if_index);
 291               o->data[6] = 5;   /* suboption 5 (client RX intfc address) */
 292               o->data[7] = 4;   /* length 4 */
 293               u32 *o_addr = (u32 *) & o->data[8];
 294               *o_addr = ia0->as_u32;
 295               o->data[12] = DHCP_PACKET_OPTION_END;
 296
 297               vss = dhcp_get_vss_info (dpm, fib_index, FIB_PROTOCOL_IP4);
 298               if (vss)
 299                 {
 300                   u32 id_len;   /* length of VPN ID */
 301
 302                   if (vss->vss_type == VSS_TYPE_VPN_ID)
 303                     {
 304                       id_len = sizeof (vss->vpn_id);    /* vpn_id is 7 bytes */
 305                       memcpy (&o->data[15], vss->vpn_id, id_len);
 306                     }
 307                   else if (vss->vss_type == VSS_TYPE_ASCII)
 308                     {
 309                       id_len = vec_len (vss->vpn_ascii_id);
 310                       memcpy (&o->data[15], vss->vpn_ascii_id, id_len);
 311                     }
 312                   else          /* must be VSS_TYPE_DEFAULT, no VPN ID */
 313                     id_len = 0;
 314
 315                   o->data[12] = 151;    /* vss suboption */
 316                   o->data[13] = id_len + 1;     /* length: vss_type + id_len */
 317                   o->data[14] = vss->vss_type;  /* vss option type */
 318                   o->data[15 + id_len] = 152;   /* vss control suboption */
 319                   o->data[16 + id_len] = 0;     /* length */
 320                   o->data[17 + id_len] = DHCP_PACKET_OPTION_END;        /* "end-of-options" (0xFF) */
 321                   /* 5 bytes for suboption headers 151+len, 152+len and 0xFF */
 322                   o->length += id_len + 5;
 323                 }
 324
 325               len = o->length + 3;
 326               b0->current_length += len;
 327               /* Fix IP header length and checksum */
 328               old_l0 = ip0->length;
 329               new_l0 = clib_net_to_host_u16 (old_l0);
 330               new_l0 += len;
 331               new_l0 = clib_host_to_net_u16 (new_l0);
 332               ip0->length = new_l0;
 333               sum0 = ip0->checksum;
 334               sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
 335                                      length /* changed member */ );
 336               ip0->checksum = ip_csum_fold (sum0);
 337
 338               /* Fix UDP length */
 339               new_l0 = clib_net_to_host_u16 (u0->length);
 340               new_l0 += len;
 341               u0->length = clib_host_to_net_u16 (new_l0);
 342             }
 343           else
 344             {
 345               vlib_node_increment_counter
 346                 (vm, dhcp_proxy_to_server_node.index,
 347                  DHCP_PROXY_ERROR_OPTION_82_ERROR, 1);
 348             }
 349
 350           next0 = DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP;
 351
 352           /*
 353            * If we have multiple servers configured and this is the
 354            * client's discover message, then send copies to each of
 355            * those servers
 356            */
 357           if (is_discover && vec_len (proxy->dhcp_servers) > 1)
 358             {
 359               u32 ii;
 360
 361               for (ii = 1; ii < vec_len (proxy->dhcp_servers); ii++)
 362                 {
 363                   vlib_buffer_t *c0;
 364                   u32 ci0;
 365
 366                   c0 = vlib_buffer_copy (vm, b0);
 367                   VLIB_BUFFER_TRACE_TRAJECTORY_INIT (c0);
 368                   ci0 = vlib_get_buffer_index (vm, c0);
 369                   server = &proxy->dhcp_servers[ii];
 370
 371                   ip0 = vlib_buffer_get_current (c0);
 372
 373                   sum0 = ip0->checksum;
 374                   old0 = ip0->dst_address.as_u32;
 375                   new0 = server->dhcp_server.ip4.as_u32;
 376                   ip0->dst_address.as_u32 = server->dhcp_server.ip4.as_u32;
 377                   sum0 = ip_csum_update (sum0, old0, new0,
 378                                          ip4_header_t /* structure */ ,
 379                                          dst_address /* changed member */ );
 380                   ip0->checksum = ip_csum_fold (sum0);
 381
 382                   to_next[0] = ci0;
 383                   to_next += 1;
 384                   n_left_to_next -= 1;
 385
 386                   vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 387                                                    to_next, n_left_to_next,
 388                                                    ci0, next0);
 389
 390                   if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 391                     {
 392                       dhcp_proxy_trace_t *tr;
 393
 394                       tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
 395                       tr->which = 0;    /* to server */
 396                       tr->error = error0;
 397                       tr->original_sw_if_index = original_sw_if_index;
 398                       tr->sw_if_index = sw_if_index;
 399                       if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 400                         tr->trace_ip4_address.as_u32 =
 401                           server->dhcp_server.ip4.as_u32;
 402
 403                       clib_memcpy_fast (tr->packet_data, h0,
 404                                         sizeof (tr->packet_data));
 405
 406                     }
 407
 408                   if (PREDICT_FALSE (0 == n_left_to_next))
 409                     {
 410                       vlib_put_next_frame (vm, node, next_index,
 411                                            n_left_to_next);
 412                       vlib_get_next_frame (vm, node, next_index,
 413                                            to_next, n_left_to_next);
 414                     }
 415                 }
 416             }
 417         do_trace:
 418           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 419             {
 420               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 421                                                        b0, sizeof (*tr));
 422               tr->which = 0;    /* to server */
 423               tr->error = error0;
 424               tr->original_sw_if_index = original_sw_if_index;
 425               tr->sw_if_index = sw_if_index;
 426               if (next0 == DHCP_PROXY_TO_SERVER_INPUT_NEXT_LOOKUP)
 427                 tr->trace_ip4_address.as_u32 =
 428                   proxy->dhcp_servers[0].dhcp_server.ip4.as_u32;
 429               clib_memcpy_fast (tr->packet_data, h0,
 430                                 sizeof (tr->packet_data));
 431             }
 432
 433         do_enqueue:
 434           to_next[0] = bi0;
 435           to_next += 1;
 436           n_left_to_next -= 1;
 437
 438           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 439                                            to_next, n_left_to_next,
 440                                            bi0, next0);
 441         }
 442
 443       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 444     }
 445   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 446                                DHCP_PROXY_ERROR_RELAY_TO_CLIENT,
 447                                pkts_to_client);
 448   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 449                                DHCP_PROXY_ERROR_RELAY_TO_SERVER,
 450                                pkts_to_server);
 451   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 452                                DHCP_PROXY_ERROR_NO_SERVER, pkts_no_server);
 453   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 454                                DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS,
 455                                pkts_no_interface_address);
 456   vlib_node_increment_counter (vm, dhcp_proxy_to_server_node.index,
 457                                DHCP_PROXY_ERROR_PKT_TOO_BIG, pkts_too_big);
 458   return from_frame->n_vectors;
 459 }
 460
 461 /* *INDENT-OFF* */
 462 VLIB_REGISTER_NODE (dhcp_proxy_to_server_node, static) = {
 463   .function = dhcp_proxy_to_server_input,
 464   .name = "dhcp-proxy-to-server",
 465   /* Takes a vector of packets. */
 466   .vector_size = sizeof (u32),
 467
 468   .n_errors = DHCP_PROXY_N_ERROR,
 469   .error_strings = dhcp_proxy_error_strings,
 470
 471   .n_next_nodes = DHCP_PROXY_TO_SERVER_INPUT_N_NEXT,
 472   .next_nodes = {
 473 #define _(s,n) [DHCP_PROXY_TO_SERVER_INPUT_NEXT_##s] = n,
 474     foreach_dhcp_proxy_to_server_input_next
 475 #undef _
 476   },
 477
 478   .format_buffer = format_dhcp_proxy_header_with_length,
 479   .format_trace = format_dhcp_proxy_trace,
 480 #if 0
 481   .unformat_buffer = unformat_dhcp_proxy_header,
 482 #endif
 483 };
 484 /* *INDENT-ON* */
 485
 486 typedef enum
 487 {
 488   DHCP4_PROXY_NEXT_DROP,
 489   DHCP4_PROXY_NEXT_TX,
 490   DHCP4_PROXY_N_NEXT,
 491 } dhcp4_next_t;
 492
 493 static uword
 494 dhcp_proxy_to_client_input (vlib_main_t * vm,
 495                             vlib_node_runtime_t * node,
 496                             vlib_frame_t * from_frame)
 497 {
 498   u32 n_left_from, *from, *to_next, n_left_to_next;
 499   ethernet_main_t *em = vnet_get_ethernet_main ();
 500   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
 501   vnet_main_t *vnm = vnet_get_main ();
 502   ip4_main_t *im = &ip4_main;
 503   u32 next_index;
 504
 505   from = vlib_frame_vector_args (from_frame);
 506   n_left_from = from_frame->n_vectors;
 507   next_index = node->cached_next_index;
 508
 509   while (n_left_from > 0)
 510     {
 511       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 512
 513       while (n_left_from > 0 && n_left_to_next > 0)
 514         {
 515           u32 bi0;
 516           vlib_buffer_t *b0;
 517           udp_header_t *u0;
 518           dhcp_header_t *h0;
 519           ip4_header_t *ip0 = 0;
 520           ip4_address_t *ia0 = 0;
 521           u32 old0, new0;
 522           ip_csum_t sum0;
 523           ethernet_interface_t *ei0;
 524           ethernet_header_t *mac0;
 525           vnet_hw_interface_t *hi0;
 526           u32 sw_if_index = ~0;
 527           vnet_sw_interface_t *si0;
 528           u32 error0 = (u32) ~ 0;
 529           vnet_sw_interface_t *swif;
 530           u32 fib_index;
 531           dhcp_proxy_t *proxy;
 532           dhcp_server_t *server;
 533           u32 original_sw_if_index = (u32) ~ 0;
 534           dhcp4_next_t next0 = DHCP4_PROXY_NEXT_TX;
 535           ip4_address_t relay_addr = {
 536             .as_u32 = 0,
 537           };
 538
 539           bi0 = to_next[0] = from[0];
 540           from += 1;
 541           to_next += 1;
 542           n_left_from -= 1;
 543           n_left_to_next -= 1;
 544
 545           b0 = vlib_get_buffer (vm, bi0);
 546           h0 = vlib_buffer_get_current (b0);
 547
 548           /*
 549            * udp_local hands us the DHCP header, need udp hdr,
 550            * ip hdr to relay to client
 551            */
 552           vlib_buffer_advance (b0, -(sizeof (*u0)));
 553           u0 = vlib_buffer_get_current (b0);
 554
 555           vlib_buffer_advance (b0, -(sizeof (*ip0)));
 556           ip0 = vlib_buffer_get_current (b0);
 557
 558           /* Consumed by dhcp client code? */
 559           if (dhcp_client_for_us (bi0, b0, ip0, u0, h0))
 560             {
 561               error0 = DHCP_PROXY_ERROR_FOR_US;
 562               goto drop_packet;
 563             }
 564
 565           // if (1 /* dpm->insert_option_82 */ )
 566           /* linearize needed to "unclone" and scan options */
 567           int rv = vlib_buffer_chain_linearize (vm, b0);
 568           if ((b0->flags & VLIB_BUFFER_NEXT_PRESENT) != 0 || !rv)
 569             {
 570               error0 = DHCP_PROXY_ERROR_PKT_TOO_BIG;
 571               goto drop_packet;
 572             }
 573
 574           dhcp_option_t *o = h0->options, *end =
 575             (void *) vlib_buffer_get_tail (b0);
 576
 577           /* Parse through TLVs looking for option 82.
 578              The circuit-ID is the FIB number we need
 579              to track down the client-facing interface */
 580
 581           while (o->option != DHCP_PACKET_OPTION_END && o < end)
 582             {
 583               if (o->option == 82)
 584                 {
 585                   u32 vss_exist = 0;
 586                   u32 vss_ctrl = 0;
 587                   dhcp_option_t *sub = (dhcp_option_t *) & o->data[0];
 588                   dhcp_option_t *subend =
 589                     (dhcp_option_t *) (o->data + o->length);
 590                   while (sub->option != DHCP_PACKET_OPTION_END
 591                          && sub < subend)
 592                     {
 593                       /* If this is one of ours, it will have
 594                          total length 12, circuit-id suboption type,
 595                          and the sw_if_index */
 596                       if (sub->option == 1 && sub->length == 4)
 597                         {
 598                           sw_if_index = ((sub->data[0] << 24) |
 599                                          (sub->data[1] << 16) |
 600                                          (sub->data[2] << 8) |
 601                                          (sub->data[3]));
 602                         }
 603                       else if (sub->option == 5 && sub->length == 4)
 604                         {
 605                           relay_addr.as_u8[0] = sub->data[0];
 606                           relay_addr.as_u8[1] = sub->data[1];
 607                           relay_addr.as_u8[2] = sub->data[2];
 608                           relay_addr.as_u8[3] = sub->data[3];
 609                         }
 610                       else if (sub->option == 151 &&
 611                                sub->length == 7 && sub->data[0] == 1)
 612                         vss_exist = 1;
 613                       else if (sub->option == 152 && sub->length == 0)
 614                         vss_ctrl = 1;
 615                       sub = (dhcp_option_t *) (sub->data + sub->length);
 616                     }
 617                   if (vss_ctrl && vss_exist)
 618                     vlib_node_increment_counter
 619                       (vm, dhcp_proxy_to_client_node.index,
 620                        DHCP_PROXY_ERROR_OPTION_82_VSS_NOT_PROCESSED, 1);
 621
 622                 }
 623               o = (dhcp_option_t *) (o->data + o->length);
 624             }
 625
 626           if (sw_if_index == (u32) ~ 0)
 627             {
 628               error0 = DHCP_PROXY_ERROR_NO_OPTION_82;
 629
 630             drop_packet:
 631               vlib_node_increment_counter (vm,
 632                                            dhcp_proxy_to_client_node.index,
 633                                            error0, 1);
 634               b0->error = node->errors[error0];
 635               next0 = DHCP4_PROXY_NEXT_DROP;
 636               goto do_trace;
 637             }
 638
 639           if (relay_addr.as_u32 == 0)
 640             {
 641               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ADDR;
 642               goto drop_packet;
 643             }
 644
 645           if (sw_if_index >= vec_len (im->fib_index_by_sw_if_index))
 646             {
 647               error0 = DHCP_PROXY_ERROR_BAD_OPTION_82_ITF;
 648               goto drop_packet;
 649             }
 650
 651           fib_index = im->fib_index_by_sw_if_index[sw_if_index];
 652           proxy = dhcp_get_proxy (dpm, fib_index, FIB_PROTOCOL_IP4);
 653
 654           if (PREDICT_FALSE (NULL == proxy))
 655             {
 656               error0 = DHCP_PROXY_ERROR_NO_SERVER;
 657               goto drop_packet;
 658             }
 659
 660           vec_foreach (server, proxy->dhcp_servers)
 661           {
 662             if (ip0->src_address.as_u32 == server->dhcp_server.ip4.as_u32)
 663               {
 664                 goto server_found;
 665               }
 666           }
 667
 668           error0 = DHCP_PROXY_ERROR_BAD_SVR_FIB_OR_ADDRESS;
 669           goto drop_packet;
 670
 671         server_found:
 672           vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index;
 673
 674           swif = vnet_get_sw_interface (vnm, sw_if_index);
 675           original_sw_if_index = sw_if_index;
 676           if (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED)
 677             sw_if_index = swif->unnumbered_sw_if_index;
 678
 679           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
 680           if (ia0 == 0)
 681             {
 682               error0 = DHCP_PROXY_ERROR_NO_INTERFACE_ADDRESS;
 683               goto drop_packet;
 684             }
 685
 686           if (relay_addr.as_u32 != ia0->as_u32)
 687             {
 688               error0 = DHCP_PROXY_ERROR_BAD_YIADDR;
 689               goto drop_packet;
 690             }
 691
 692           u0->checksum = 0;
 693           u0->dst_port = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client);
 694           sum0 = ip0->checksum;
 695           old0 = ip0->dst_address.as_u32;
 696           new0 = 0xFFFFFFFF;
 697           ip0->dst_address.as_u32 = new0;
 698           sum0 =
 699             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 700                             dst_address /* offset of changed member */ );
 701           ip0->checksum = ip_csum_fold (sum0);
 702
 703           sum0 = ip0->checksum;
 704           old0 = ip0->src_address.as_u32;
 705           new0 = ia0->as_u32;
 706           ip0->src_address.as_u32 = new0;
 707           sum0 =
 708             ip_csum_update (sum0, old0, new0, ip4_header_t /* structure */ ,
 709                             src_address /* offset of changed member */ );
 710           ip0->checksum = ip_csum_fold (sum0);
 711
 712           vlib_buffer_advance (b0, -(sizeof (ethernet_header_t)));
 713           si0 = vnet_get_sw_interface (vnm, original_sw_if_index);
 714           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 715             vlib_buffer_advance (b0, -4 /* space for VLAN tag */ );
 716
 717           mac0 = vlib_buffer_get_current (b0);
 718
 719           hi0 = vnet_get_sup_hw_interface (vnm, original_sw_if_index);
 720           ei0 = pool_elt_at_index (em->interfaces, hi0->hw_instance);
 721           clib_memcpy (mac0->src_address, ei0->address,
 722                        sizeof (ei0->address));
 723           clib_memset (mac0->dst_address, 0xff, sizeof (mac0->dst_address));
 724           mac0->type = (si0->type == VNET_SW_INTERFACE_TYPE_SUB) ?
 725             clib_net_to_host_u16 (0x8100) : clib_net_to_host_u16 (0x0800);
 726
 727           if (si0->type == VNET_SW_INTERFACE_TYPE_SUB)
 728             {
 729               u32 *vlan_tag = (u32 *) (mac0 + 1);
 730               u32 tmp;
 731               tmp = (si0->sub.id << 16) | 0x0800;
 732               *vlan_tag = clib_host_to_net_u32 (tmp);
 733             }
 734
 735         do_trace:
 736           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 737             {
 738               dhcp_proxy_trace_t *tr = vlib_add_trace (vm, node,
 739                                                        b0, sizeof (*tr));
 740               tr->which = 1;    /* to client */
 741               tr->trace_ip4_address.as_u32 = ia0 ? ia0->as_u32 : 0;
 742               tr->error = error0;
 743               tr->original_sw_if_index = original_sw_if_index;
 744               tr->sw_if_index = sw_if_index;
 745               clib_memcpy_fast (tr->packet_data, h0,
 746                                 sizeof (tr->packet_data));
 747             }
 748
 749           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 750                                            to_next, n_left_to_next,
 751                                            bi0, next0);
 752         }
 753       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 754     }
 755
 756   return from_frame->n_vectors;
 757 }
 758
 759 /* *INDENT-OFF* */
 760 VLIB_REGISTER_NODE (dhcp_proxy_to_client_node, static) = {
 761   .function = dhcp_proxy_to_client_input,
 762   .name = "dhcp-proxy-to-client",
 763   /* Takes a vector of packets. */
 764   .vector_size = sizeof (u32),
 765
 766   .n_errors = DHCP_PROXY_N_ERROR,
 767   .error_strings = dhcp_proxy_error_strings,
 768   .format_buffer = format_dhcp_proxy_header_with_length,
 769   .format_trace = format_dhcp_proxy_trace,
 770 #if 0
 771   .unformat_buffer = unformat_dhcp_proxy_header,
 772 #endif
 773   .n_next_nodes = DHCP4_PROXY_N_NEXT,
 774   .next_nodes = {
 775     [DHCP4_PROXY_NEXT_DROP] = "error-drop",
 776     [DHCP4_PROXY_NEXT_TX] = "interface-output",
 777   },
 778 };
 779 /* *INDENT-ON* */
 780
 781 void
 782 dhcp_maybe_register_udp_ports (dhcp_port_reg_flags_t ports)
 783 {
 784   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 785   vlib_main_t *vm = dm->vlib_main;
 786   int port_regs_diff = dm->udp_ports_registered ^ ports;
 787
 788   if (!port_regs_diff)
 789     return;
 790
 791   if ((port_regs_diff & DHCP_PORT_REG_CLIENT) & ports)
 792     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_client,
 793                            dhcp_proxy_to_client_node.index, 1 /* is_ip4 */ );
 794
 795   if ((port_regs_diff & DHCP_PORT_REG_SERVER) & ports)
 796     udp_register_dst_port (vm, UDP_DST_PORT_dhcp_to_server,
 797                            dhcp_proxy_to_server_node.index, 1 /* is_ip4 */ );
 798
 799   dm->udp_ports_registered |= ports;
 800 }
 801
 802 static clib_error_t *
 803 dhcp4_proxy_init (vlib_main_t * vm)
 804 {
 805   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
 806   vlib_node_t *error_drop_node;
 807
 808   error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
 809   dm->error_drop_node_index = error_drop_node->index;
 810   dm->vlib_main = vm;
 811
 812   return 0;
 813 }
 814
 815
 816 VLIB_INIT_FUNCTION (dhcp4_proxy_init);
 817
 818 int
 819 dhcp4_proxy_set_server (ip46_address_t * addr,
 820                         ip46_address_t * src_addr,
 821                         u32 rx_table_id, u32 server_table_id, int is_del)
 822 {
 823   u32 rx_fib_index = 0;
 824   int rc = 0;
 825
 826   const fib_prefix_t all_1s = {
 827     .fp_len = 32,
 828     .fp_addr.ip4.as_u32 = 0xffffffff,
 829     .fp_proto = FIB_PROTOCOL_IP4,
 830   };
 831
 832   if (ip46_address_is_zero (addr))
 833     return VNET_API_ERROR_INVALID_DST_ADDRESS;
 834
 835   if (ip46_address_is_zero (src_addr))
 836     return VNET_API_ERROR_INVALID_SRC_ADDRESS;
 837
 838   dhcp_maybe_register_udp_ports (DHCP_PORT_REG_CLIENT | DHCP_PORT_REG_SERVER);
 839
 840   rx_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
 841                                                     rx_table_id,
 842                                                     FIB_SOURCE_DHCP);
 843
 844   if (is_del)
 845     {
 846       if (dhcp_proxy_server_del (FIB_PROTOCOL_IP4, rx_fib_index,
 847                                  addr, server_table_id))
 848         {
 849           fib_table_entry_special_remove (rx_fib_index,
 850                                           &all_1s, FIB_SOURCE_DHCP);
 851           fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 852         }
 853     }
 854   else
 855     {
 856       if (dhcp_proxy_server_add (FIB_PROTOCOL_IP4,
 857                                  addr, src_addr,
 858                                  rx_fib_index, server_table_id))
 859         {
 860           fib_table_entry_special_add (rx_fib_index,
 861                                        &all_1s,
 862                                        FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_LOCAL);
 863           fib_table_lock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 864         }
 865     }
 866   fib_table_unlock (rx_fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_DHCP);
 867
 868   return (rc);
 869 }
 870
 871 static clib_error_t *
 872 dhcp4_proxy_set_command_fn (vlib_main_t * vm,
 873                             unformat_input_t * input,
 874                             vlib_cli_command_t * cmd)
 875 {
 876   ip46_address_t server_addr, src_addr;
 877   u32 server_table_id = 0, rx_table_id = 0;
 878   int is_del = 0;
 879   int set_src = 0, set_server = 0;
 880
 881   clib_memset (&server_addr, 0, sizeof (server_addr));
 882   clib_memset (&src_addr, 0, sizeof (src_addr));
 883
 884   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 885     {
 886       if (unformat (input, "server %U",
 887                     unformat_ip4_address, &server_addr.ip4))
 888         set_server = 1;
 889       else if (unformat (input, "server-fib-id %d", &server_table_id))
 890         ;
 891       else if (unformat (input, "rx-fib-id %d", &rx_table_id))
 892         ;
 893       else if (unformat (input, "src-address %U",
 894                          unformat_ip4_address, &src_addr.ip4))
 895         set_src = 1;
 896       else if (unformat (input, "delete") || unformat (input, "del"))
 897         is_del = 1;
 898       else
 899         break;
 900     }
 901
 902   if (is_del || (set_server && set_src))
 903     {
 904       int rv;
 905
 906       rv = dhcp4_proxy_set_server (&server_addr, &src_addr, rx_table_id,
 907                                    server_table_id, is_del);
 908       switch (rv)
 909         {
 910         case 0:
 911           return 0;
 912
 913         case VNET_API_ERROR_INVALID_DST_ADDRESS:
 914           return clib_error_return (0, "Invalid server address");
 915
 916         case VNET_API_ERROR_INVALID_SRC_ADDRESS:
 917           return clib_error_return (0, "Invalid src address");
 918
 919         case VNET_API_ERROR_NO_SUCH_ENTRY:
 920           return clib_error_return
 921             (0, "Fib id %d: no per-fib DHCP server configured", rx_table_id);
 922
 923         default:
 924           return clib_error_return (0, "BUG: rv %d", rv);
 925         }
 926     }
 927   else
 928     return clib_error_return (0, "parse error`%U'",
 929                               format_unformat_error, input);
 930 }
 931
 932 /* *INDENT-OFF* */
 933 VLIB_CLI_COMMAND (dhcp_proxy_set_command, static) = {
 934   .path = "set dhcp proxy",
 935   .short_help = "set dhcp proxy [del] server <ip-addr> src-address <ip-addr> [server-fib-id <n>] [rx-fib-id <n>]",
 936   .function = dhcp4_proxy_set_command_fn,
 937 };
 938 /* *INDENT-ON* */
 939
 940 static u8 *
 941 format_dhcp4_proxy_server (u8 * s, va_list * args)
 942 {
 943   dhcp_proxy_t *proxy = va_arg (*args, dhcp_proxy_t *);
 944   ip4_fib_t *rx_fib, *server_fib;
 945   dhcp_server_t *server;
 946
 947   if (proxy == 0)
 948     {
 949       s = format (s, "%=14s%=16s%s", "RX FIB", "Src Address",
 950                   "Servers FIB,Address");
 951       return s;
 952     }
 953
 954   rx_fib = ip4_fib_get (proxy->rx_fib_index);
 955
 956   s = format (s, "%=14u%=16U",
 957               rx_fib->table_id,
 958               format_ip46_address, &proxy->dhcp_src_address, IP46_TYPE_ANY);
 959
 960   vec_foreach (server, proxy->dhcp_servers)
 961   {
 962     server_fib = ip4_fib_get (server->server_fib_index);
 963     s = format (s, "%u,%U  ",
 964                 server_fib->table_id,
 965                 format_ip46_address, &server->dhcp_server, IP46_TYPE_ANY);
 966   }
 967   return s;
 968 }
 969
 970 static int
 971 dhcp4_proxy_show_walk (dhcp_proxy_t * server, void *ctx)
 972 {
 973   vlib_main_t *vm = ctx;
 974
 975   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server, server);
 976
 977   return (1);
 978 }
 979
 980 static clib_error_t *
 981 dhcp4_proxy_show_command_fn (vlib_main_t * vm,
 982                              unformat_input_t * input,
 983                              vlib_cli_command_t * cmd)
 984 {
 985   vlib_cli_output (vm, "%U", format_dhcp4_proxy_server,
 986                    NULL /* header line */ );
 987
 988   dhcp_proxy_walk (FIB_PROTOCOL_IP4, dhcp4_proxy_show_walk, vm);
 989
 990   return (NULL);
 991 }
 992
 993 /* *INDENT-OFF* */
 994 VLIB_CLI_COMMAND (dhcp_proxy_show_command, static) = {
 995   .path = "show dhcp proxy",
 996   .short_help = "Display dhcp proxy server info",
 997   .function = dhcp4_proxy_show_command_fn,
 998 };
 999 /* *INDENT-ON* */
1000
1001 static clib_error_t *
1002 dhcp_option_82_vss_fn (vlib_main_t * vm,
1003                        unformat_input_t * input, vlib_cli_command_t * cmd)
1004 {
1005   u8 is_del = 0, vss_type = VSS_TYPE_DEFAULT;
1006   u32 oui = 0, fib_id = 0, tbl_id = ~0;
1007   u8 *vpn_ascii_id = 0;
1008
1009   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1010     {
1011       if (unformat (input, "table %d", &tbl_id))
1012         ;
1013       else if (unformat (input, "oui %d", &oui))
1014         vss_type = VSS_TYPE_VPN_ID;
1015       else if (unformat (input, "vpn-id %d", &fib_id))
1016         vss_type = VSS_TYPE_VPN_ID;
1017       else if (unformat (input, "vpn-ascii-id %s", &vpn_ascii_id))
1018         vss_type = VSS_TYPE_ASCII;
1019       else if (unformat (input, "delete") || unformat (input, "del"))
1020         is_del = 1;
1021       else
1022         break;
1023     }
1024
1025   if (tbl_id == ~0)
1026     return clib_error_return (0, "no table ID specified.");
1027
1028   int rv = dhcp_proxy_set_vss (FIB_PROTOCOL_IP4, tbl_id, vss_type,
1029                                vpn_ascii_id, oui, fib_id, is_del);
1030   switch (rv)
1031     {
1032     case 0:
1033       return 0;
1034     case VNET_API_ERROR_NO_SUCH_ENTRY:
1035       return clib_error_return (0,
1036                                 "option 82 vss for table %d not found in in pool.",
1037                                 tbl_id);
1038     default:
1039       return clib_error_return (0, "BUG: rv %d", rv);
1040
1041     }
1042 }
1043
1044 /* *INDENT-OFF* */
1045 VLIB_CLI_COMMAND (dhcp_proxy_vss_command,static) = {
1046   .path = "set dhcp option-82 vss",
1047   .short_help = "set dhcp option-82 vss [del] table <table id> [oui <n> vpn-id <n> | vpn-ascii-id <text>]",
1048   .function = dhcp_option_82_vss_fn,
1049 };
1050 /* *INDENT-ON* */
1051
1052 static clib_error_t *
1053 dhcp_vss_show_command_fn (vlib_main_t * vm,
1054                           unformat_input_t * input, vlib_cli_command_t * cmd)
1055 {
1056   dhcp_vss_walk (FIB_PROTOCOL_IP4, dhcp_vss_show_walk, vm);
1057
1058   return (NULL);
1059 }
1060
1061 /* *INDENT-OFF* */
1062 VLIB_CLI_COMMAND (dhcp_proxy_vss_show_command, static) = {
1063   .path = "show dhcp vss",
1064   .short_help = "show dhcp VSS",
1065   .function = dhcp_vss_show_command_fn,
1066 };
1067 /* *INDENT-ON* */
1068
1069 static clib_error_t *
1070 dhcp_option_82_address_show_command_fn (vlib_main_t * vm,
1071                                         unformat_input_t * input,
1072                                         vlib_cli_command_t * cmd)
1073 {
1074   vnet_main_t *vnm = vnet_get_main ();
1075   u32 sw_if_index0 = 0, sw_if_index;
1076   vnet_sw_interface_t *swif;
1077   ip4_address_t *ia0;
1078
1079   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1080     {
1081
1082       if (unformat (input, "%U",
1083                     unformat_vnet_sw_interface, vnm, &sw_if_index0))
1084         {
1085           swif = vnet_get_sw_interface (vnm, sw_if_index0);
1086           sw_if_index = (swif->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED) ?
1087             swif->unnumbered_sw_if_index : sw_if_index0;
1088           ia0 = ip4_interface_first_address (&ip4_main, sw_if_index, 0);
1089           if (ia0)
1090             {
1091               vlib_cli_output (vm, "%=20s%=20s", "interface",
1092                                "source IP address");
1093
1094               vlib_cli_output (vm, "%=20U%=20U",
1095                                format_vnet_sw_if_index_name,
1096                                vnm, sw_if_index0, format_ip4_address, ia0);
1097             }
1098           else
1099             vlib_cli_output (vm, "%=34s %=20U",
1100                              "No IPv4 address configured on",
1101                              format_vnet_sw_if_index_name, vnm, sw_if_index);
1102         }
1103       else
1104         break;
1105     }
1106
1107   return 0;
1108 }
1109
1110 /* *INDENT-OFF* */
1111 VLIB_CLI_COMMAND (dhcp_proxy_address_show_command,static) = {
1112   .path = "show dhcp option-82-address interface",
1113   .short_help = "show dhcp option-82-address interface <interface>",
1114   .function = dhcp_option_82_address_show_command_fn,
1115 };
1116 /* *INDENT-ON* */
1117
1118 /*
1119  * fd.io coding-style-patch-verification: ON
1120  *
1121  * Local Variables:
1122  * eval: (c-set-style "gnu")
1123  * End:
1124  */