NetworkPkg/DnsDxe/DnsImpl.h

   1 /** @file
   2 DnsDxe support functions implementation.
   3
   4 Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #ifndef __EFI_DNS_IMPL_H_
  16 #define __EFI_DNS_IMPL_H_
  17
  18 #include <Uefi.h>
  19
  20 //
  21 // Libraries classes
  22 //
  23 #include <Library/BaseLib.h>
  24 #include <Library/UefiLib.h>
  25 #include <Library/UefiBootServicesTableLib.h>
  26 #include <Library/UefiDriverEntryPoint.h>
  27 #include <Library/UefiRuntimeServicesTableLib.h>
  28 #include <Library/BaseMemoryLib.h>
  29 #include <Library/MemoryAllocationLib.h>
  30 #include <Library/NetLib.h>
  31 #include <Library/DebugLib.h>
  32 #include <Library/DpcLib.h>
  33 #include <Library/PrintLib.h>
  34 #include <Library/UdpIoLib.h>
  35
  36 //
  37 // UEFI Driver Model Protocols
  38 //
  39 #include <Protocol/DriverBinding.h>
  40 #include <Protocol/ComponentName2.h>
  41 #include <Protocol/ComponentName.h>
  42
  43 #include <Protocol/Udp4.h>
  44 #include <Protocol/Dhcp4.h>
  45 #include <Protocol/Dns4.h>
  46
  47 #include <Protocol/Udp6.h>
  48 #include <Protocol/Dhcp6.h>
  49 #include <Protocol/Dns6.h>
  50
  51 #include <Protocol/Ip4Config2.h>
  52
  53 #include "DnsDriver.h"
  54 #include "DnsDhcp.h"
  55
  56 //
  57 // Driver Version
  58 //
  59 #define DNS_VERSION  0x00000000
  60
  61 //
  62 // Protocol instances
  63 //
  64 extern EFI_COMPONENT_NAME_PROTOCOL   gDnsComponentName;
  65 extern EFI_COMPONENT_NAME2_PROTOCOL  gDnsComponentName2;
  66 extern EFI_UNICODE_STRING_TABLE      *gDnsControllerNameTable;
  67
  68 extern EFI_DRIVER_BINDING_PROTOCOL   gDns4DriverBinding;
  69 extern EFI_SERVICE_BINDING_PROTOCOL  mDns4ServiceBinding;
  70 extern EFI_DNS4_PROTOCOL             mDns4Protocol;
  71
  72 extern EFI_DRIVER_BINDING_PROTOCOL   gDns6DriverBinding;
  73 extern EFI_SERVICE_BINDING_PROTOCOL  mDns6ServiceBinding;
  74 extern EFI_DNS6_PROTOCOL             mDns6Protocol;
  75
  76 //
  77 // DNS related
  78 //
  79 #define DNS_SERVER_PORT   53
  80
  81 #define DNS_PROTOCOL_UDP   EFI_IP_PROTO_UDP
  82 #define DNS_PROTOCOL_TCP   EFI_IP_PROTO_TCP
  83
  84 #define DNS_STATE_UNCONFIGED     0
  85 #define DNS_STATE_CONFIGED       1
  86 #define DNS_STATE_DESTROY        2
  87
  88 #define DNS_DEFAULT_TIMEOUT      2
  89 #define DNS_DEFAULT_RETRY        3
  90
  91 #define DNS_TIME_TO_GETMAP       5
  92
  93 #pragma pack(1)
  94
  95 typedef union _DNS_FLAGS  DNS_FLAGS;
  96
  97 typedef struct {
  98   LIST_ENTRY             AllCacheLink;
  99   EFI_DNS4_CACHE_ENTRY   DnsCache;
 100 } DNS4_CACHE;
 101
 102 typedef struct {
 103   LIST_ENTRY             AllCacheLink;
 104   EFI_DNS6_CACHE_ENTRY   DnsCache;
 105 } DNS6_CACHE;
 106
 107 typedef struct {
 108   LIST_ENTRY             AllServerLink;
 109   EFI_IPv4_ADDRESS       Dns4ServerIp;
 110 } DNS4_SERVER_IP;
 111
 112 typedef struct {
 113   LIST_ENTRY             AllServerLink;
 114   EFI_IPv6_ADDRESS       Dns6ServerIp;
 115 } DNS6_SERVER_IP;
 116
 117 typedef struct {
 118   UINT32                     PacketToLive;
 119   CHAR16                     *QueryHostName;
 120   EFI_IPv4_ADDRESS           QueryIpAddress;
 121   BOOLEAN                    GeneralLookUp;
 122   EFI_DNS4_COMPLETION_TOKEN  *Token;
 123 } DNS4_TOKEN_ENTRY;
 124
 125 typedef struct {
 126   UINT32                     PacketToLive;
 127   CHAR16                     *QueryHostName;
 128   EFI_IPv6_ADDRESS           QueryIpAddress;
 129   BOOLEAN                    GeneralLookUp;
 130   EFI_DNS6_COMPLETION_TOKEN  *Token;
 131 } DNS6_TOKEN_ENTRY;
 132
 133 union _DNS_FLAGS{
 134   struct {
 135     UINT16     RCode:4;
 136     UINT16     Zero:3;
 137     UINT16     RA:1;
 138     UINT16     RD:1;
 139     UINT16     TC:1;
 140     UINT16     AA:1;
 141     UINT16     OpCode:4;
 142     UINT16     QR:1;
 143   } Bits;
 144   UINT16  Uint16;
 145 };
 146
 147 #define DNS_FLAGS_QR_QUERY     0
 148 #define DNS_FLAGS_QR_RESPONSE  1
 149
 150 #define DNS_FLAGS_OPCODE_STANDARD     0
 151 #define DNS_FLAGS_OPCODE_INVERSE      1
 152 #define DNS_FLAGS_OPCODE_SERVER_STATE 2
 153
 154 #define DNS_FLAGS_RCODE_NO_ERROR    0
 155 #define DNS_FLAGS_RCODE_NAME_ERROR  3
 156
 157 typedef struct {
 158   UINT16      Identification;
 159   DNS_FLAGS   Flags;
 160   UINT16      QuestionsNum;
 161   UINT16      AnswersNum;
 162   UINT16      AuthorityNum;
 163   UINT16      AditionalNum;
 164 } DNS_HEADER;
 165
 166 typedef struct {
 167   UINT16      Type;
 168   UINT16      Class;
 169 } DNS_QUERY_SECTION;
 170
 171 typedef struct {
 172   UINT16      Type;
 173   UINT16      Class;
 174   UINT32      Ttl;
 175   UINT16      DataLength;
 176 } DNS_ANSWER_SECTION;
 177
 178 #define DNS4_DOMAIN  L"in-addr.arpa"
 179 #define DNS6_DOMAIN  L"IP6.ARPA"
 180
 181
 182 #pragma pack()
 183
 184 /**
 185   Remove TokenEntry from TokenMap.
 186
 187   @param[in] TokenMap          All DNSv4 Token entrys.
 188   @param[in] TokenEntry        TokenEntry need to be removed.
 189
 190   @retval EFI_SUCCESS          Remove TokenEntry from TokenMap sucessfully.
 191   @retval EFI_NOT_FOUND        TokenEntry is not found in TokenMap.
 192
 193 **/
 194 EFI_STATUS
 195 Dns4RemoveTokenEntry (
 196   IN NET_MAP                    *TokenMap,
 197   IN DNS4_TOKEN_ENTRY           *TokenEntry
 198   );
 199
 200 /**
 201   Remove TokenEntry from TokenMap.
 202
 203   @param[in] TokenMap           All DNSv6 Token entrys.
 204   @param[in] TokenEntry         TokenEntry need to be removed.
 205
 206   @retval EFI_SUCCESS           Remove TokenEntry from TokenMap sucessfully.
 207   @retval EFI_NOT_FOUND         TokenEntry is not found in TokenMap.
 208
 209 **/
 210 EFI_STATUS
 211 Dns6RemoveTokenEntry (
 212   IN NET_MAP                    *TokenMap,
 213   IN DNS6_TOKEN_ENTRY           *TokenEntry
 214   );
 215
 216 /**
 217   This function cancle the token specified by Arg in the Map.
 218
 219   @param[in]  Map             Pointer to the NET_MAP.
 220   @param[in]  Item            Pointer to the NET_MAP_ITEM.
 221   @param[in]  Arg             Pointer to the token to be cancelled. If NULL, all
 222                               the tokens in this Map will be cancelled.
 223                               This parameter is optional and may be NULL.
 224
 225   @retval EFI_SUCCESS         The token is cancelled if Arg is NULL, or the token
 226                               is not the same as that in the Item, if Arg is not
 227                               NULL.
 228   @retval EFI_ABORTED         Arg is not NULL, and the token specified by Arg is
 229                               cancelled.
 230
 231 **/
 232 EFI_STATUS
 233 EFIAPI
 234 Dns4CancelTokens (
 235   IN NET_MAP       *Map,
 236   IN NET_MAP_ITEM  *Item,
 237   IN VOID          *Arg OPTIONAL
 238   );
 239
 240 /**
 241   This function cancle the token specified by Arg in the Map.
 242
 243   @param[in]  Map             Pointer to the NET_MAP.
 244   @param[in]  Item            Pointer to the NET_MAP_ITEM.
 245   @param[in]  Arg             Pointer to the token to be cancelled. If NULL, all
 246                               the tokens in this Map will be cancelled.
 247                               This parameter is optional and may be NULL.
 248
 249   @retval EFI_SUCCESS         The token is cancelled if Arg is NULL, or the token
 250                               is not the same as that in the Item, if Arg is not
 251                               NULL.
 252   @retval EFI_ABORTED         Arg is not NULL, and the token specified by Arg is
 253                               cancelled.
 254
 255 **/
 256 EFI_STATUS
 257 EFIAPI
 258 Dns6CancelTokens (
 259   IN NET_MAP       *Map,
 260   IN NET_MAP_ITEM  *Item,
 261   IN VOID          *Arg OPTIONAL
 262   );
 263
 264 /**
 265   Get the TokenEntry from the TokensMap.
 266
 267   @param[in]  TokensMap           All DNSv4 Token entrys
 268   @param[in]  Token               Pointer to the token to be get.
 269   @param[out] TokenEntry          Pointer to TokenEntry corresponding Token.
 270
 271   @retval EFI_SUCCESS             Get the TokenEntry from the TokensMap sucessfully.
 272   @retval EFI_NOT_FOUND           TokenEntry is not found in TokenMap.
 273
 274 **/
 275 EFI_STATUS
 276 EFIAPI
 277 GetDns4TokenEntry (
 278   IN     NET_MAP                   *TokensMap,
 279   IN     EFI_DNS4_COMPLETION_TOKEN *Token,
 280      OUT DNS4_TOKEN_ENTRY          **TokenEntry
 281   );
 282
 283 /**
 284   Get the TokenEntry from the TokensMap.
 285
 286   @param[in]  TokensMap           All DNSv6 Token entrys
 287   @param[in]  Token               Pointer to the token to be get.
 288   @param[out] TokenEntry          Pointer to TokenEntry corresponding Token.
 289
 290   @retval EFI_SUCCESS             Get the TokenEntry from the TokensMap sucessfully.
 291   @retval EFI_NOT_FOUND           TokenEntry is not found in TokenMap.
 292
 293 **/
 294 EFI_STATUS
 295 EFIAPI
 296 GetDns6TokenEntry (
 297   IN     NET_MAP                   *TokensMap,
 298   IN     EFI_DNS6_COMPLETION_TOKEN *Token,
 299      OUT DNS6_TOKEN_ENTRY          **TokenEntry
 300   );
 301
 302 /**
 303   Cancel DNS4 tokens from the DNS4 instance.
 304
 305   @param[in]  Instance           Pointer to the DNS instance context data.
 306   @param[in]  Token              Pointer to the token to be canceled. If NULL, all
 307                                  tokens in this instance will be cancelled.
 308                                  This parameter is optional and may be NULL.
 309
 310   @retval EFI_SUCCESS            The Token is cancelled.
 311   @retval EFI_NOT_FOUND          The Token is not found.
 312
 313 **/
 314 EFI_STATUS
 315 Dns4InstanceCancelToken (
 316   IN DNS_INSTANCE               *Instance,
 317   IN EFI_DNS4_COMPLETION_TOKEN  *Token
 318   );
 319
 320 /**
 321   Cancel DNS6 tokens from the DNS6 instance.
 322
 323   @param[in]  Instance           Pointer to the DNS instance context data.
 324   @param[in]  Token              Pointer to the token to be canceled. If NULL, all
 325                                  tokens in this instance will be cancelled.
 326                                  This parameter is optional and may be NULL.
 327
 328   @retval EFI_SUCCESS            The Token is cancelled.
 329   @retval EFI_NOT_FOUND          The Token is not found.
 330
 331 **/
 332 EFI_STATUS
 333 Dns6InstanceCancelToken (
 334   IN DNS_INSTANCE               *Instance,
 335   IN EFI_DNS6_COMPLETION_TOKEN  *Token
 336   );
 337
 338 /**
 339   Free the resource related to the configure parameters.
 340
 341   @param  Config                 The DNS configure data
 342
 343 **/
 344 VOID
 345 Dns4CleanConfigure (
 346   IN OUT EFI_DNS4_CONFIG_DATA  *Config
 347   );
 348
 349 /**
 350   Free the resource related to the configure parameters.
 351
 352   @param  Config                 The DNS configure data
 353
 354 **/
 355 VOID
 356 Dns6CleanConfigure (
 357   IN OUT EFI_DNS6_CONFIG_DATA  *Config
 358   );
 359
 360 /**
 361   Allocate memory for configure parameter such as timeout value for Dst,
 362   then copy the configure parameter from Src to Dst.
 363
 364   @param[out]  Dst               The destination DHCP configure data.
 365   @param[in]   Src               The source DHCP configure data.
 366
 367   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory.
 368   @retval EFI_SUCCESS            The configure is copied.
 369
 370 **/
 371 EFI_STATUS
 372 Dns4CopyConfigure (
 373   OUT EFI_DNS4_CONFIG_DATA  *Dst,
 374   IN  EFI_DNS4_CONFIG_DATA  *Src
 375   );
 376
 377 /**
 378   Allocate memory for configure parameter such as timeout value for Dst,
 379   then copy the configure parameter from Src to Dst.
 380
 381   @param[out]  Dst               The destination DHCP configure data.
 382   @param[in]   Src               The source DHCP configure data.
 383
 384   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory.
 385   @retval EFI_SUCCESS            The configure is copied.
 386
 387 **/
 388 EFI_STATUS
 389 Dns6CopyConfigure (
 390   OUT EFI_DNS6_CONFIG_DATA  *Dst,
 391   IN  EFI_DNS6_CONFIG_DATA  *Src
 392   );
 393
 394 /**
 395   Callback of Dns packet. Does nothing.
 396
 397   @param Arg           The context.
 398
 399 **/
 400 VOID
 401 EFIAPI
 402 DnsDummyExtFree (
 403   IN VOID                   *Arg
 404   );
 405
 406 /**
 407   Poll the UDP to get the IP4 default address, which may be retrieved
 408   by DHCP.
 409
 410   The default time out value is 5 seconds. If IP has retrieved the default address,
 411   the UDP is reconfigured.
 412
 413   @param  Instance               The DNS instance
 414   @param  UdpIo                  The UDP_IO to poll
 415   @param  UdpCfgData             The UDP configure data to reconfigure the UDP_IO
 416
 417   @retval TRUE                   The default address is retrieved and UDP is reconfigured.
 418   @retval FALSE                  Some error occured.
 419
 420 **/
 421 BOOLEAN
 422 Dns4GetMapping (
 423   IN DNS_INSTANCE           *Instance,
 424   IN UDP_IO                 *UdpIo,
 425   IN EFI_UDP4_CONFIG_DATA   *UdpCfgData
 426   );
 427
 428 /**
 429   Configure the opened Udp6 instance until the corresponding Ip6 instance
 430   has been configured.
 431
 432   @param  Instance               The DNS instance
 433   @param  UdpIo                  The UDP_IO to poll
 434   @param  UdpCfgData             The UDP configure data to reconfigure the UDP_IO
 435
 436   @retval TRUE                   Configure the Udp6 instance successfully.
 437   @retval FALSE                  Some error occured.
 438
 439 **/
 440 BOOLEAN
 441 Dns6GetMapping (
 442   IN DNS_INSTANCE           *Instance,
 443   IN UDP_IO                 *UdpIo,
 444   IN EFI_UDP6_CONFIG_DATA   *UdpCfgData
 445   );
 446
 447 /**
 448   Configure the UDP.
 449
 450   @param  Instance               The DNS session
 451   @param  UdpIo                  The UDP_IO instance
 452
 453   @retval EFI_SUCCESS            The UDP is successfully configured for the
 454                                  session.
 455
 456 **/
 457 EFI_STATUS
 458 Dns4ConfigUdp (
 459   IN DNS_INSTANCE           *Instance,
 460   IN UDP_IO                 *UdpIo
 461   );
 462
 463 /**
 464   Configure the UDP.
 465
 466   @param  Instance               The DNS session
 467   @param  UdpIo                  The UDP_IO instance
 468
 469   @retval EFI_SUCCESS            The UDP is successfully configured for the
 470                                  session.
 471
 472 **/
 473 EFI_STATUS
 474 Dns6ConfigUdp (
 475   IN DNS_INSTANCE           *Instance,
 476   IN UDP_IO                 *UdpIo
 477   );
 478
 479 /**
 480   Update Dns4 cache to shared list of caches of all DNSv4 instances.
 481
 482   @param  Dns4CacheList      All Dns4 cache list.
 483   @param  DeleteFlag         If FALSE, this function is to add one entry to the DNS Cache.
 484                              If TRUE, this function will delete matching DNS Cache entry.
 485   @param  Override           If TRUE, the matching DNS cache entry will be overwritten with the supplied parameter.
 486                              If FALSE, EFI_ACCESS_DENIED will be returned if the entry to be added is already exists.
 487   @param  DnsCacheEntry      Entry Pointer to DNS Cache entry.
 488
 489   @retval EFI_SUCCESS        Update Dns4 cache successfully.
 490   @retval Others             Failed to update Dns4 cache.
 491
 492 **/
 493 EFI_STATUS
 494 EFIAPI
 495 UpdateDns4Cache (
 496   IN LIST_ENTRY             *Dns4CacheList,
 497   IN BOOLEAN                DeleteFlag,
 498   IN BOOLEAN                Override,
 499   IN EFI_DNS4_CACHE_ENTRY   DnsCacheEntry
 500   );
 501
 502 /**
 503   Update Dns6 cache to shared list of caches of all DNSv6 instances.
 504
 505   @param  Dns6CacheList      All Dns6 cache list.
 506   @param  DeleteFlag         If FALSE, this function is to add one entry to the DNS Cache.
 507                              If TRUE, this function will delete matching DNS Cache entry.
 508   @param  Override           If TRUE, the matching DNS cache entry will be overwritten with the supplied parameter.
 509                              If FALSE, EFI_ACCESS_DENIED will be returned if the entry to be added is already exists.
 510   @param  DnsCacheEntry      Entry Pointer to DNS Cache entry.
 511
 512   @retval EFI_SUCCESS        Update Dns6 cache successfully.
 513   @retval Others             Failed to update Dns6 cache.
 514 **/
 515 EFI_STATUS
 516 EFIAPI
 517 UpdateDns6Cache (
 518   IN LIST_ENTRY             *Dns6CacheList,
 519   IN BOOLEAN                DeleteFlag,
 520   IN BOOLEAN                Override,
 521   IN EFI_DNS6_CACHE_ENTRY   DnsCacheEntry
 522   );
 523
 524 /**
 525   Add Dns4 ServerIp to common list of addresses of all configured DNSv4 server.
 526
 527   @param  Dns4ServerList    Common list of addresses of all configured DNSv4 server.
 528   @param  ServerIp          DNS server Ip.
 529
 530   @retval EFI_SUCCESS       Add Dns4 ServerIp to common list successfully.
 531   @retval Others            Failed to add Dns4 ServerIp to common list.
 532
 533 **/
 534 EFI_STATUS
 535 EFIAPI
 536 AddDns4ServerIp (
 537   IN LIST_ENTRY                *Dns4ServerList,
 538   IN EFI_IPv4_ADDRESS           ServerIp
 539   );
 540
 541 /**
 542   Add Dns6 ServerIp to common list of addresses of all configured DNSv6 server.
 543
 544   @param  Dns6ServerList    Common list of addresses of all configured DNSv6 server.
 545   @param  ServerIp          DNS server Ip.
 546
 547   @retval EFI_SUCCESS       Add Dns6 ServerIp to common list successfully.
 548   @retval Others            Failed to add Dns6 ServerIp to common list.
 549
 550 **/
 551 EFI_STATUS
 552 EFIAPI
 553 AddDns6ServerIp (
 554   IN LIST_ENTRY                *Dns6ServerList,
 555   IN EFI_IPv6_ADDRESS           ServerIp
 556   );
 557
 558 /**
 559   Find out whether the response is valid or invalid.
 560
 561   @param  TokensMap       All DNS transmittal Tokens entry.
 562   @param  Identification  Identification for queried packet.
 563   @param  Type            Type for queried packet.
 564   @param  Class           Class for queried packet.
 565   @param  Item            Return corresponding Token entry.
 566
 567   @retval TRUE            The response is valid.
 568   @retval FALSE           The response is invalid.
 569
 570 **/
 571 BOOLEAN
 572 IsValidDnsResponse (
 573   IN     NET_MAP      *TokensMap,
 574   IN     UINT16       Identification,
 575   IN     UINT16       Type,
 576   IN     UINT16       Class,
 577      OUT NET_MAP_ITEM **Item
 578   );
 579
 580 /**
 581   Parse Dns Response.
 582
 583   @param  Instance              The DNS instance
 584   @param  RxString              Received buffer.
 585   @param  Completed             Flag to indicate that Dns response is valid.
 586
 587   @retval EFI_SUCCESS           Parse Dns Response successfully.
 588   @retval Others                Failed to parse Dns Response.
 589
 590 **/
 591 EFI_STATUS
 592 ParseDnsResponse (
 593   IN OUT DNS_INSTANCE              *Instance,
 594   IN     UINT8                     *RxString,
 595      OUT BOOLEAN                   *Completed
 596   );
 597
 598 /**
 599   Parse response packet.
 600
 601   @param  Packet                The packets received.
 602   @param  EndPoint              The local/remote UDP access point
 603   @param  IoStatus              The status of the UDP receive
 604   @param  Context               The opaque parameter to the function.
 605
 606 **/
 607 VOID
 608 EFIAPI
 609 DnsOnPacketReceived (
 610   NET_BUF                   *Packet,
 611   UDP_END_POINT             *EndPoint,
 612   EFI_STATUS                IoStatus,
 613   VOID                      *Context
 614   );
 615
 616 /**
 617   Release the net buffer when packet is sent.
 618
 619   @param  Packet                The packets received.
 620   @param  EndPoint              The local/remote UDP access point
 621   @param  IoStatus              The status of the UDP receive
 622   @param  Context               The opaque parameter to the function.
 623
 624 **/
 625 VOID
 626 EFIAPI
 627 DnsOnPacketSent (
 628   NET_BUF                   *Packet,
 629   UDP_END_POINT             *EndPoint,
 630   EFI_STATUS                IoStatus,
 631   VOID                      *Context
 632   );
 633
 634 /**
 635   Query request information.
 636
 637   @param  Instance              The DNS instance
 638   @param  Packet                The packet for querying request information.
 639
 640   @retval EFI_SUCCESS           Query request information successfully.
 641   @retval Others                Failed to query request information.
 642
 643 **/
 644 EFI_STATUS
 645 DoDnsQuery (
 646   IN  DNS_INSTANCE              *Instance,
 647   IN  NET_BUF                   *Packet
 648   );
 649
 650 /**
 651   Construct the Packet according query section.
 652
 653   @param  Instance              The DNS instance
 654   @param  QueryName             Queried Name
 655   @param  Type                  Queried Type
 656   @param  Class                 Queried Class
 657   @param  Packet                The packet for query
 658
 659   @retval EFI_SUCCESS           The packet is constructed.
 660   @retval Others                Failed to construct the Packet.
 661
 662 **/
 663 EFI_STATUS
 664 ConstructDNSQuery (
 665   IN  DNS_INSTANCE              *Instance,
 666   IN  CHAR8                     *QueryName,
 667   IN  UINT16                    Type,
 668   IN  UINT16                    Class,
 669   OUT NET_BUF                   **Packet
 670   );
 671
 672 /**
 673   Retransmit the packet.
 674
 675   @param  Instance              The DNS instance
 676   @param  Packet                Retransmit the packet
 677
 678   @retval EFI_SUCCESS           The packet is retransmitted.
 679   @retval Others                Failed to retransmit.
 680
 681 **/
 682 EFI_STATUS
 683 DnsRetransmit (
 684   IN DNS_INSTANCE        *Instance,
 685   IN NET_BUF             *Packet
 686   );
 687
 688 /**
 689   The timer ticking function for the DNS service.
 690
 691   @param  Event                 The ticking event
 692   @param  Context               The DNS service instance
 693
 694 **/
 695 VOID
 696 EFIAPI
 697 DnsOnTimerRetransmit (
 698   IN EFI_EVENT              Event,
 699   IN VOID                   *Context
 700   );
 701
 702 /**
 703   The timer ticking function for the DNS driver.
 704
 705   @param  Event                 The ticking event
 706   @param  Context               NULL
 707
 708 **/
 709 VOID
 710 EFIAPI
 711 DnsOnTimerUpdate (
 712   IN EFI_EVENT              Event,
 713   IN VOID                   *Context
 714   );
 715
 716
 717 /**
 718   Retrieve mode data of this DNS instance.
 719
 720   This function is used to retrieve DNS mode data for this DNS instance.
 721
 722   @param[in]   This               Pointer to EFI_DNS4_PROTOCOL instance.
 723   @param[out]  DnsModeData        Point to the mode data.
 724
 725   @retval EFI_SUCCESS             The operation completed successfully.
 726   @retval EFI_NOT_STARTED         When DnsConfigData is queried, no configuration data
 727                                   is available because this instance has not been
 728                                   configured.
 729   @retval EFI_INVALID_PARAMETER   This is NULL or DnsModeData is NULL.
 730   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
 731 **/
 732 EFI_STATUS
 733 EFIAPI
 734 Dns4GetModeData (
 735   IN  EFI_DNS4_PROTOCOL          *This,
 736   OUT EFI_DNS4_MODE_DATA         *DnsModeData
 737   );
 738
 739 /**
 740   Configure this DNS instance.
 741
 742   This function is used to configure DNS mode data for this DNS instance.
 743
 744   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 745   @param[in]  DnsConfigData       Point to the Configuration data.
 746
 747   @retval EFI_SUCCESS             The operation completed successfully.
 748   @retval EFI_UNSUPPORTED         The designated protocol is not supported.
 749   @retval EFI_INVALID_PARAMTER    Thisis NULL.
 750                                   The StationIp address provided in DnsConfigData is not a
 751                                   valid unicast.
 752                                   DnsServerList is NULL while DnsServerListCount
 753                                   is not ZERO.
 754                                   DnsServerListCount is ZERO while DnsServerList
 755                                   is not NULL
 756   @retval EFI_OUT_OF_RESOURCES    The DNS instance data or required space could not be
 757                                   allocated.
 758   @retval EFI_DEVICE_ERROR        An unexpected system or network error occurred. The
 759                                   EFI DNSv4 Protocol instance is not configured.
 760   @retval EFI_ALREADY_STARTED     Second call to Configure() with DnsConfigData. To
 761                                   reconfigure the instance the caller must call Configure()
 762                                   with NULL first to return driver to unconfigured state.
 763 **/
 764 EFI_STATUS
 765 EFIAPI
 766 Dns4Configure (
 767   IN EFI_DNS4_PROTOCOL           *This,
 768   IN EFI_DNS4_CONFIG_DATA        *DnsConfigData
 769   );
 770
 771 /**
 772   Host name to host address translation.
 773
 774   The HostNameToIp () function is used to translate the host name to host IP address. A
 775   type A query is used to get the one or more IP addresses for this host.
 776
 777   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 778   @param[in]  HostName            Host name.
 779   @param[in]  Token               Point to the completion token to translate host name
 780                                   to host address.
 781
 782   @retval EFI_SUCCESS             The operation completed successfully.
 783   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
 784                                   This is NULL.
 785                                   Token is NULL.
 786                                   Token.Event is NULL.
 787                                   HostName is NULL. HostName string is unsupported format.
 788   @retval EFI_NO_MAPPING          There's no source address is available for use.
 789   @retval EFI_NOT_STARTED         This instance has not been started.
 790 **/
 791 EFI_STATUS
 792 EFIAPI
 793 Dns4HostNameToIp (
 794   IN  EFI_DNS4_PROTOCOL          *This,
 795   IN  CHAR16                    *HostName,
 796   IN  EFI_DNS4_COMPLETION_TOKEN  *Token
 797   );
 798
 799 /**
 800   IPv4 address to host name translation also known as Reverse DNS lookup.
 801
 802   The IpToHostName() function is used to translate the host address to host name. A type PTR
 803   query is used to get the primary name of the host. Support of this function is optional.
 804
 805   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 806   @param[in]  IpAddress           Ip Address.
 807   @param[in]  Token               Point to the completion token to translate host
 808                                   address to host name.
 809
 810   @retval EFI_SUCCESS             The operation completed successfully.
 811   @retval EFI_UNSUPPORTED         This function is not supported.
 812   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
 813                                   This is NULL.
 814                                   Token is NULL.
 815                                   Token.Event is NULL.
 816                                   IpAddress is not valid IP address .
 817   @retval EFI_NO_MAPPING          There's no source address is available for use.
 818   @retval EFI_ALREADY_STARTED     This Token is being used in another DNS session.
 819   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
 820 **/
 821 EFI_STATUS
 822 EFIAPI
 823 Dns4IpToHostName (
 824   IN  EFI_DNS4_PROTOCOL             *This,
 825   IN  EFI_IPv4_ADDRESS              IpAddress,
 826   IN  EFI_DNS4_COMPLETION_TOKEN     *Token
 827   );
 828
 829 /**
 830   Retrieve arbitrary information from the DNS server.
 831
 832   This GeneralLookup() function retrieves arbitrary information from the DNS. The caller
 833   supplies a QNAME, QTYPE, and QCLASS, and all of the matching RRs are returned. All
 834   RR content (e.g., TTL) was returned. The caller need parse the returned RR to get
 835   required information. The function is optional.
 836
 837   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 838   @param[in]  QName               Pointer to Query Name.
 839   @param[in]  QType               Query Type.
 840   @param[in]  QClass              Query Name.
 841   @param[in]  Token               Point to the completion token to retrieve arbitrary
 842                                   information.
 843
 844   @retval EFI_SUCCESS             The operation completed successfully.
 845   @retval EFI_UNSUPPORTED         This function is not supported. Or the requested
 846                                   QType is not supported
 847   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
 848                                   This is NULL.
 849                                   Token is NULL.
 850                                   Token.Event is NULL.
 851                                   QName is NULL.
 852   @retval EFI_NO_MAPPING          There's no source address is available for use.
 853   @retval EFI_ALREADY_STARTED     This Token is being used in another DNS session.
 854   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
 855 **/
 856 EFI_STATUS
 857 EFIAPI
 858 Dns4GeneralLookUp (
 859   IN  EFI_DNS4_PROTOCOL                *This,
 860   IN  CHAR8                            *QName,
 861   IN  UINT16                           QType,
 862   IN  UINT16                           QClass,
 863   IN  EFI_DNS4_COMPLETION_TOKEN        *Token
 864   );
 865
 866 /**
 867   This function is to update the DNS Cache.
 868
 869   The UpdateDnsCache() function is used to add/delete/modify DNS cache entry. DNS cache
 870   can be normally dynamically updated after the DNS resolve succeeds. This function
 871   provided capability to manually add/delete/modify the DNS cache.
 872
 873   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 874   @param[in]  DeleteFlag          If FALSE, this function is to add one entry to the
 875                                   DNS Cahce. If TRUE, this function will delete
 876                                   matching DNS Cache entry.
 877   @param[in]  Override            If TRUE, the maching DNS cache entry will be
 878                                   overwritten with the supplied parameter. If FALSE,
 879                                   EFI_ACCESS_DENIED will be returned if the entry to
 880                                   be added is already existed.
 881   @param[in]  DnsCacheEntry       Pointer to DNS Cache entry.
 882
 883   @retval EFI_SUCCESS             The operation completed successfully.
 884   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
 885                                   This is NULL.
 886                                   DnsCacheEntry.HostName is NULL.
 887                                   DnsCacheEntry.IpAddress is NULL.
 888                                   DnsCacheEntry.Timeout is zero.
 889   @retval EFI_ACCESS_DENIED       The DNS cache entry already exists and Override is
 890                                   not TRUE.
 891 **/
 892 EFI_STATUS
 893 EFIAPI
 894 Dns4UpdateDnsCache (
 895   IN EFI_DNS4_PROTOCOL      *This,
 896   IN BOOLEAN               DeleteFlag,
 897   IN BOOLEAN               Override,
 898   IN EFI_DNS4_CACHE_ENTRY   DnsCacheEntry
 899   );
 900
 901 /**
 902   Polls for incoming data packets and processes outgoing data packets.
 903
 904   The Poll() function can be used by network drivers and applications to increase the
 905   rate that data packets are moved between the communications device and the transmit
 906   and receive queues.
 907   In some systems, the periodic timer event in the managed network driver may not poll
 908   the underlying communications device fast enough to transmit and/or receive all data
 909   packets without missing incoming packets or dropping outgoing packets. Drivers and
 910   applications that are experiencing packet loss should try calling the Poll()
 911   function more often.
 912
 913   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 914
 915   @retval EFI_SUCCESS             Incoming or outgoing data was processed.
 916   @retval EFI_NOT_STARTED         This EFI DNS Protocol instance has not been started.
 917   @retval EFI_INVALID_PARAMETER   This is NULL.
 918   @retval EFI_DEVICE_ERROR        An unexpected system or network error occurred.
 919   @retval EFI_TIMEOUT             Data was dropped out of the transmit and/or receive
 920                                   queue. Consider increasing the polling rate.
 921 **/
 922 EFI_STATUS
 923 EFIAPI
 924 Dns4Poll (
 925   IN EFI_DNS4_PROTOCOL    *This
 926   );
 927
 928 /**
 929   Abort an asynchronous DNS operation, including translation between IP and Host, and
 930   general look up behavior.
 931
 932   The Cancel() function is used to abort a pending resolution request. After calling
 933   this function, Token.Status will be set to EFI_ABORTED and then Token.Event will be
 934   signaled. If the token is not in one of the queues, which usually means that the
 935   asynchronous operation has completed, this function will not signal the token and
 936   EFI_NOT_FOUND is returned.
 937
 938   @param[in]  This                Pointer to EFI_DNS4_PROTOCOL instance.
 939   @param[in]  Token               Pointer to a token that has been issued by
 940                                   EFI_DNS4_PROTOCOL.HostNameToIp (),
 941                                   EFI_DNS4_PROTOCOL.IpToHostName() or
 942                                   EFI_DNS4_PROTOCOL.GeneralLookup().
 943                                   If NULL, all pending tokens are aborted.
 944
 945   @retval EFI_SUCCESS             Incoming or outgoing data was processed.
 946   @retval EFI_NOT_STARTED         This EFI DNS4 Protocol instance has not been started.
 947   @retval EFI_INVALID_PARAMETER   This is NULL.
 948   @retval EFI_NOT_FOUND           When Token is not NULL, and the asynchronous DNS
 949                                   operation was not found in the transmit queue. It
 950                                   was either completed or was not issued by
 951                                   HostNameToIp(), IpToHostName() or GeneralLookup().
 952 **/
 953 EFI_STATUS
 954 EFIAPI
 955 Dns4Cancel (
 956   IN  EFI_DNS4_PROTOCOL          *This,
 957   IN  EFI_DNS4_COMPLETION_TOKEN  *Token
 958   );
 959
 960
 961 /**
 962   Retrieve mode data of this DNS instance.
 963
 964   This function is used to retrieve DNS mode data for this DNS instance.
 965
 966   @param[in]   This                Pointer to EFI_DNS6_PROTOCOL instance.
 967   @param[out]  DnsModeData         Pointer to the caller-allocated storage for the
 968                                    EFI_DNS6_MODE_DATA data.
 969
 970   @retval EFI_SUCCESS             The operation completed successfully.
 971   @retval EFI_NOT_STARTED         When DnsConfigData is queried, no configuration data
 972                                   is available because this instance has not been
 973                                   configured.
 974   @retval EFI_INVALID_PARAMETER   This is NULL or DnsModeData is NULL.
 975   @retval EFI_OUT_OF_RESOURCE     Failed to allocate needed resources.
 976 **/
 977 EFI_STATUS
 978 EFIAPI
 979 Dns6GetModeData (
 980   IN  EFI_DNS6_PROTOCOL          *This,
 981   OUT EFI_DNS6_MODE_DATA         *DnsModeData
 982   );
 983
 984 /**
 985   Configure this DNS instance.
 986
 987   The Configure() function is used to set and change the configuration data for this
 988   EFI DNSv6 Protocol driver instance. Reset the DNS instance if DnsConfigData is NULL.
 989
 990   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
 991   @param[in]  DnsConfigData       Pointer to the configuration data structure. All associated
 992                                   storage to be allocated and released by caller.
 993
 994   @retval EFI_SUCCESS             The operation completed successfully.
 995   @retval EFI_INVALID_PARAMTER    This is NULL.
 996                                   The StationIp address provided in DnsConfigData is not zero and not a valid unicast.
 997                                   DnsServerList is NULL while DnsServerList Count is not ZERO.
 998                                   DnsServerList Count is ZERO while DnsServerList is not NULL.
 999   @retval EFI_OUT_OF_RESOURCES    The DNS instance data or required space could not be allocated.
1000   @retval EFI_DEVICE_ERROR        An unexpected system or network error occurred. The
1001                                   EFI DNSv6 Protocol instance is not configured.
1002   @retval EFI_UNSUPPORTED         The designated protocol is not supported.
1003   @retval EFI_ALREADY_STARTED     Second call to Configure() with DnsConfigData. To
1004                                   reconfigure the instance the caller must call Configure() with
1005                                   NULL first to return driver to unconfigured state.
1006 **/
1007 EFI_STATUS
1008 EFIAPI
1009 Dns6Configure (
1010   IN EFI_DNS6_PROTOCOL           *This,
1011   IN EFI_DNS6_CONFIG_DATA        *DnsConfigData
1012   );
1013
1014 /**
1015   Host name to host address translation.
1016
1017   The HostNameToIp () function is used to translate the host name to host IP address. A
1018   type AAAA query is used to get the one or more IPv6 addresses for this host.
1019
1020   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1021   @param[in]  HostName            Host name.
1022   @param[in]  Token               Point to the completion token to translate host name
1023                                   to host address.
1024
1025   @retval EFI_SUCCESS             The operation completed successfully.
1026   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
1027                                   This is NULL.
1028                                   Token is NULL.
1029                                   Token.Event is NULL.
1030                                   HostName is NULL or buffer contained unsupported characters.
1031   @retval EFI_NO_MAPPING          There's no source address is available for use.
1032   @retval EFI_ALREADY_STARTED     This Token is being used in another DNS session.
1033   @retval EFI_NOT_STARTED         This instance has not been started.
1034   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
1035 **/
1036 EFI_STATUS
1037 EFIAPI
1038 Dns6HostNameToIp (
1039   IN  EFI_DNS6_PROTOCOL          *This,
1040   IN  CHAR16                     *HostName,
1041   IN  EFI_DNS6_COMPLETION_TOKEN  *Token
1042   );
1043
1044 /**
1045   Host address to host name translation.
1046
1047   The IpToHostName () function is used to translate the host address to host name. A
1048   type PTR query is used to get the primary name of the host. Implementation can choose
1049   to support this function or not.
1050
1051   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1052   @param[in]  IpAddress           Ip Address.
1053   @param[in]  Token               Point to the completion token to translate host
1054                                   address to host name.
1055
1056   @retval EFI_SUCCESS             The operation completed successfully.
1057   @retval EFI_UNSUPPORTED         This function is not supported.
1058   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
1059                                   This is NULL.
1060                                   Token is NULL.
1061                                   Token.Event is NULL.
1062                                   IpAddress is not valid IP address.
1063   @retval EFI_NO_MAPPING          There's no source address is available for use.
1064   @retval EFI_NOT_STARTED         This instance has not been started.
1065   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
1066 **/
1067 EFI_STATUS
1068 EFIAPI
1069 Dns6IpToHostName (
1070   IN  EFI_DNS6_PROTOCOL             *This,
1071   IN  EFI_IPv6_ADDRESS              IpAddress,
1072   IN  EFI_DNS6_COMPLETION_TOKEN     *Token
1073   );
1074
1075 /**
1076   This function provides capability to retrieve arbitrary information from the DNS
1077   server.
1078
1079   This GeneralLookup() function retrieves arbitrary information from the DNS. The caller
1080   supplies a QNAME, QTYPE, and QCLASS, and all of the matching RRs are returned. All
1081   RR content (e.g., TTL) was returned. The caller need parse the returned RR to get
1082   required information. The function is optional. Implementation can choose to support
1083   it or not.
1084
1085   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1086   @param[in]  QName               Pointer to Query Name.
1087   @param[in]  QType               Query Type.
1088   @param[in]  QClass              Query Name.
1089   @param[in]  Token               Point to the completion token to retrieve arbitrary
1090                                   information.
1091
1092   @retval EFI_SUCCESS             The operation completed successfully.
1093   @retval EFI_UNSUPPORTED         This function is not supported. Or the requested
1094                                   QType is not supported
1095   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
1096                                   This is NULL.
1097                                   Token is NULL.
1098                                   Token.Event is NULL.
1099                                   QName is NULL.
1100   @retval EFI_NO_MAPPING          There's no source address is available for use.
1101   @retval EFI_NOT_STARTED         This instance has not been started.
1102   @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
1103 **/
1104 EFI_STATUS
1105 EFIAPI
1106 Dns6GeneralLookUp (
1107   IN  EFI_DNS6_PROTOCOL                *This,
1108   IN  CHAR8                            *QName,
1109   IN  UINT16                           QType,
1110   IN  UINT16                           QClass,
1111   IN  EFI_DNS6_COMPLETION_TOKEN        *Token
1112   );
1113
1114 /**
1115   This function is to update the DNS Cache.
1116
1117   The UpdateDnsCache() function is used to add/delete/modify DNS cache entry. DNS cache
1118   can be normally dynamically updated after the DNS resolve succeeds. This function
1119   provided capability to manually add/delete/modify the DNS cache.
1120
1121   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1122   @param[in]  DeleteFlag          If FALSE, this function is to add one entry to the
1123                                   DNS Cahce. If TRUE, this function will delete
1124                                   matching DNS Cache entry.
1125   @param[in]  Override            If TRUE, the maching DNS cache entry will be
1126                                   overwritten with the supplied parameter. If FALSE,
1127                                   EFI_ACCESS_DENIED will be returned if the entry to
1128                                   be added is already existed.
1129   @param[in]  DnsCacheEntry       Pointer to DNS Cache entry.
1130
1131   @retval EFI_SUCCESS             The operation completed successfully.
1132   @retval EFI_INVALID_PARAMETER   One or more of the following conditions is TRUE:
1133                                   This is NULL.
1134                                   DnsCacheEntry.HostName is NULL.
1135                                   DnsCacheEntry.IpAddress is NULL.
1136                                   DnsCacheEntry.Timeout is zero.
1137   @retval EFI_ACCESS_DENIED       The DNS cache entry already exists and Override is
1138                                   not TRUE.
1139   @retval EFI_OUT_OF_RESOURCE     Failed to allocate needed resources.
1140 **/
1141 EFI_STATUS
1142 EFIAPI
1143 Dns6UpdateDnsCache (
1144   IN EFI_DNS6_PROTOCOL      *This,
1145   IN BOOLEAN               DeleteFlag,
1146   IN BOOLEAN               Override,
1147   IN EFI_DNS6_CACHE_ENTRY   DnsCacheEntry
1148   );
1149
1150 /**
1151   Polls for incoming data packets and processes outgoing data packets.
1152
1153   The Poll() function can be used by network drivers and applications to increase the
1154   rate that data packets are moved between the communications device and the transmit
1155   and receive queues.
1156
1157   In some systems, the periodic timer event in the managed network driver may not poll
1158   the underlying communications device fast enough to transmit and/or receive all data
1159   packets without missing incoming packets or dropping outgoing packets. Drivers and
1160   applications that are experiencing packet loss should try calling the Poll()
1161   function more often.
1162
1163   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1164
1165   @retval EFI_SUCCESS             Incoming or outgoing data was processed.
1166   @retval EFI_NOT_STARTED         This EFI DNS Protocol instance has not been started.
1167   @retval EFI_INVALID_PARAMETER   This is NULL.
1168   @retval EFI_NO_MAPPING          There is no source address is available for use.
1169   @retval EFI_DEVICE_ERROR        An unexpected system or network error occurred.
1170   @retval EFI_TIMEOUT             Data was dropped out of the transmit and/or receive
1171                                   queue. Consider increasing the polling rate.
1172 **/
1173 EFI_STATUS
1174 EFIAPI
1175 Dns6Poll (
1176   IN EFI_DNS6_PROTOCOL    *This
1177   );
1178
1179 /**
1180   Abort an asynchronous DNS operation, including translation between IP and Host, and
1181   general look up behavior.
1182
1183   The Cancel() function is used to abort a pending resolution request. After calling
1184   this function, Token.Status will be set to EFI_ABORTED and then Token.Event will be
1185   signaled. If the token is not in one of the queues, which usually means that the
1186   asynchronous operation has completed, this function will not signal the token and
1187   EFI_NOT_FOUND is returned.
1188
1189   @param[in]  This                Pointer to EFI_DNS6_PROTOCOL instance.
1190   @param[in]  Token               Pointer to a token that has been issued by
1191                                   EFI_DNS6_PROTOCOL.HostNameToIp (),
1192                                   EFI_DNS6_PROTOCOL.IpToHostName() or
1193                                   EFI_DNS6_PROTOCOL.GeneralLookup().
1194                                   If NULL, all pending tokens are aborted.
1195
1196   @retval EFI_SUCCESS             Incoming or outgoing data was processed.
1197   @retval EFI_NOT_STARTED         This EFI DNS6 Protocol instance has not been started.
1198   @retval EFI_INVALID_PARAMETER   This is NULL.
1199   @retval EFI_NO_MAPPING          There's no source address is available for use.
1200   @retval EFI_NOT_FOUND           When Token is not NULL, and the asynchronous DNS
1201                                   operation was not found in the transmit queue. It
1202                                   was either completed or was not issued by
1203                                   HostNameToIp(), IpToHostName() or GeneralLookup().
1204 **/
1205 EFI_STATUS
1206 EFIAPI
1207 Dns6Cancel (
1208   IN  EFI_DNS6_PROTOCOL          *This,
1209   IN  EFI_DNS6_COMPLETION_TOKEN  *Token
1210   );
1211
1212 #endif