NetworkPkg/Ip6Dxe/Ip6Common.c

   1 /** @file
   2   The implementation of common functions shared by IP6 driver.
   3
   4   Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php.
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include "Ip6Impl.h"
  17
  18 /**
  19   Build a array of EFI_IP6_ADDRESS_INFO to be returned to the caller. The number
  20   of EFI_IP6_ADDRESS_INFO is also returned. If AddressList is NULL,
  21   only the address count is returned.
  22
  23   @param[in]  IpSb              The IP6 service binding instance.
  24   @param[out] AddressCount      The number of returned addresses.
  25   @param[out] AddressList       The pointer to the array of EFI_IP6_ADDRESS_INFO.
  26                                 This is an optional parameter.
  27
  28
  29   @retval EFI_SUCCESS           The address array successfully built.
  30   @retval EFI_OUT_OF_RESOURCES  Failed to allocate the memory for the address info.
  31   @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
  32
  33 **/
  34 EFI_STATUS
  35 Ip6BuildEfiAddressList (
  36   IN IP6_SERVICE            *IpSb,
  37   OUT UINT32                *AddressCount,
  38   OUT EFI_IP6_ADDRESS_INFO  **AddressList OPTIONAL
  39   )
  40 {
  41   UINT32                Count;
  42   LIST_ENTRY            *Entry;
  43   EFI_IP6_ADDRESS_INFO  *EfiAddrInfo;
  44   IP6_ADDRESS_INFO      *AddrInfo;
  45
  46   if (AddressCount == NULL) {
  47     return EFI_INVALID_PARAMETER;
  48   }
  49
  50   if (IpSb->LinkLocalOk) {
  51     Count = 1 + IpSb->DefaultInterface->AddressCount;
  52   } else {
  53     Count = 0;
  54   }
  55
  56   *AddressCount = Count;
  57
  58   if ((AddressList == NULL) || (Count == 0)) {
  59     return EFI_SUCCESS;
  60   }
  61
  62   if (*AddressList == NULL) {
  63     *AddressList = AllocatePool (sizeof (EFI_IP6_ADDRESS_INFO) * Count);
  64     if (*AddressList == NULL) {
  65       return EFI_OUT_OF_RESOURCES;
  66     }
  67   }
  68
  69   EfiAddrInfo = *AddressList;
  70
  71   IP6_COPY_ADDRESS (&EfiAddrInfo->Address, &IpSb->LinkLocalAddr);
  72   EfiAddrInfo->PrefixLength = IP6_LINK_LOCAL_PREFIX_LENGTH;
  73
  74   EfiAddrInfo++;
  75   Count = 1;
  76
  77   NET_LIST_FOR_EACH (Entry, &IpSb->DefaultInterface->AddressList) {
  78     AddrInfo = NET_LIST_USER_STRUCT_S (Entry, IP6_ADDRESS_INFO, Link, IP6_ADDR_INFO_SIGNATURE);
  79
  80     IP6_COPY_ADDRESS (&EfiAddrInfo->Address, &AddrInfo->Address);
  81     EfiAddrInfo->PrefixLength = AddrInfo->PrefixLength;
  82
  83     EfiAddrInfo++;
  84     Count++;
  85   }
  86
  87   ASSERT (Count == *AddressCount);
  88
  89   return EFI_SUCCESS;
  90 }
  91
  92 /**
  93   Generate the multicast addresses identify the group of all IPv6 nodes or IPv6
  94   routers defined in RFC4291.
  95
  96   All Nodes Addresses: FF01::1, FF02::1.
  97   All Router Addresses: FF01::2, FF02::2, FF05::2.
  98
  99   @param[in]  Router            If TRUE, generate all routers addresses,
 100                                 else generate all node addresses.
 101   @param[in]  Scope             interface-local(1), link-local(2), or site-local(5)
 102   @param[out] Ip6Addr           The generated multicast address.
 103
 104   @retval EFI_INVALID_PARAMETER Any input parameter is invalid.
 105   @retval EFI_SUCCESS           The address is generated.
 106
 107 **/
 108 EFI_STATUS
 109 Ip6SetToAllNodeMulticast (
 110   IN  BOOLEAN          Router,
 111   IN  UINT8            Scope,
 112   OUT EFI_IPv6_ADDRESS *Ip6Addr
 113   )
 114 {
 115   if (Ip6Addr == NULL) {
 116     return EFI_INVALID_PARAMETER;
 117   }
 118
 119   if (!Router && Scope == IP6_SITE_LOCAL_SCOPE) {
 120     return EFI_INVALID_PARAMETER;
 121   }
 122
 123   ZeroMem (Ip6Addr, sizeof (EFI_IPv6_ADDRESS));
 124   Ip6Addr->Addr[0] = 0xFF;
 125   Ip6Addr->Addr[1] = Scope;
 126
 127   if (!Router) {
 128     Ip6Addr->Addr[15] = 0x1;
 129   } else {
 130     Ip6Addr->Addr[15] = 0x2;
 131   }
 132
 133   return EFI_SUCCESS;
 134 }
 135
 136 /**
 137   This function converts MAC address to 64 bits interface ID according to RFC4291
 138   and returns the interface ID. Currently only 48-bit MAC address is supported by
 139   this function.
 140
 141   @param[in, out]  IpSb      The IP6 service binding instance.
 142
 143   @retval          NULL      The operation fails.
 144   @return                    Pointer to the generated interface ID.
 145
 146 **/
 147 UINT8 *
 148 Ip6CreateInterfaceID (
 149   IN OUT IP6_SERVICE         *IpSb
 150   )
 151 {
 152   UINT8                      InterfaceId[8];
 153   UINT8                      Byte;
 154   EFI_MAC_ADDRESS            *MacAddr;
 155   UINT32                     AddrLen;
 156
 157   NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
 158
 159   AddrLen = IpSb->SnpMode.HwAddressSize;
 160
 161   //
 162   // Currently only IEEE 802 48-bit MACs are supported to create link local address.
 163   //
 164   if (AddrLen != IP6_MAC_LEN || IpSb->InterfaceIdLen != IP6_IF_ID_LEN) {
 165     return NULL;
 166   }
 167
 168   MacAddr = &IpSb->SnpMode.CurrentAddress;
 169
 170   //
 171   // Convert MAC address to 64 bits interface ID according to Appendix A of RFC4291:
 172   // 1. Insert 0xFFFE to the middle
 173   // 2. Invert the universal/local bit - bit 6 in network order
 174   //
 175   CopyMem (InterfaceId, MacAddr, 3);
 176   InterfaceId[3] = 0xFF;
 177   InterfaceId[4] = 0xFE;
 178   CopyMem (&InterfaceId[5], &MacAddr->Addr[3], 3);
 179
 180   Byte = (UINT8) (InterfaceId[0] & IP6_U_BIT);
 181   if (Byte == IP6_U_BIT) {
 182     InterfaceId[0] &= ~IP6_U_BIT;
 183   } else {
 184     InterfaceId[0] |= IP6_U_BIT;
 185   }
 186
 187   //
 188   // Return the interface ID.
 189   //
 190   return AllocateCopyPool (IpSb->InterfaceIdLen, InterfaceId);
 191 }
 192
 193 /**
 194   This function creates link-local address from interface identifier. The
 195   interface identifier is normally created from MAC address. It might be manually
 196   configured by administrator if the link-local address created from MAC address
 197   is a duplicate address.
 198
 199   @param[in, out]  IpSb      The IP6 service binding instance.
 200
 201   @retval          NULL      If the operation fails.
 202   @return                    The generated Link Local address, in network order.
 203
 204 **/
 205 EFI_IPv6_ADDRESS *
 206 Ip6CreateLinkLocalAddr (
 207   IN OUT IP6_SERVICE           *IpSb
 208   )
 209 {
 210   EFI_IPv6_ADDRESS             *Ip6Addr;
 211   EFI_IP6_CONFIG_PROTOCOL      *Ip6Config;
 212   UINTN                        DataSize;
 213   EFI_IP6_CONFIG_INTERFACE_ID  InterfaceId;
 214   EFI_STATUS                   Status;
 215
 216   NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
 217
 218   if (IpSb->InterfaceId != NULL) {
 219     FreePool (IpSb->InterfaceId);
 220   }
 221
 222   //
 223   // Get the interface id if it is manully configured.
 224   //
 225   Ip6Config = &IpSb->Ip6ConfigInstance.Ip6Config;
 226   DataSize  = sizeof (EFI_IP6_CONFIG_INTERFACE_ID);
 227   ZeroMem (&InterfaceId, DataSize);
 228
 229   Status = Ip6Config->GetData (
 230                         Ip6Config,
 231                         Ip6ConfigDataTypeAltInterfaceId,
 232                         &DataSize,
 233                         &InterfaceId
 234                         );
 235   if (Status == EFI_NOT_FOUND) {
 236     //
 237     // Since the interface id is not configured, generate the interface id from
 238     // MAC address.
 239     //
 240     IpSb->InterfaceId = Ip6CreateInterfaceID (IpSb);
 241     if (IpSb->InterfaceId == NULL) {
 242       return NULL;
 243     }
 244
 245     CopyMem (&InterfaceId, IpSb->InterfaceId, IpSb->InterfaceIdLen);
 246     //
 247     // Record the interface id.
 248     //
 249     Status = Ip6Config->SetData (
 250                           Ip6Config,
 251                           Ip6ConfigDataTypeAltInterfaceId,
 252                           DataSize,
 253                           &InterfaceId
 254                           );
 255     if (EFI_ERROR (Status)) {
 256       FreePool (IpSb->InterfaceId);
 257       IpSb->InterfaceId = NULL;
 258       return NULL;
 259     }
 260   } else if (!EFI_ERROR (Status)) {
 261     IpSb->InterfaceId = AllocateCopyPool (DataSize, &InterfaceId);
 262     if (IpSb->InterfaceId == NULL) {
 263       return NULL;
 264     }
 265   } else {
 266     return NULL;
 267   }
 268
 269   //
 270   // Append FE80::/64 to the left of IPv6 address then return.
 271   //
 272   Ip6Addr = AllocateZeroPool (sizeof (EFI_IPv6_ADDRESS));
 273   if (Ip6Addr == NULL) {
 274     FreePool (IpSb->InterfaceId);
 275     IpSb->InterfaceId = NULL;
 276     return NULL;
 277   }
 278
 279   CopyMem (&Ip6Addr->Addr[8], IpSb->InterfaceId, IpSb->InterfaceIdLen);
 280   Ip6Addr->Addr[1] = 0x80;
 281   Ip6Addr->Addr[0] = 0xFE;
 282
 283   return Ip6Addr;
 284 }
 285
 286 /**
 287   Compute the solicited-node multicast address for an unicast or anycast address,
 288   by taking the low-order 24 bits of this address, and appending those bits to
 289   the prefix FF02:0:0:0:0:1:FF00::/104.
 290
 291   @param[in]  Ip6Addr               The unicast or anycast address, in network order.
 292   @param[out] MulticastAddr         The generated solicited-node multicast address,
 293                                     in network order.
 294
 295 **/
 296 VOID
 297 Ip6CreateSNMulticastAddr (
 298   IN EFI_IPv6_ADDRESS  *Ip6Addr,
 299   OUT EFI_IPv6_ADDRESS *MulticastAddr
 300   )
 301 {
 302   ASSERT (Ip6Addr != NULL && MulticastAddr != NULL);
 303
 304   ZeroMem (MulticastAddr, sizeof (EFI_IPv6_ADDRESS));
 305
 306   MulticastAddr->Addr[0]  = 0xFF;
 307   MulticastAddr->Addr[1]  = 0x02;
 308   MulticastAddr->Addr[11] = 0x1;
 309   MulticastAddr->Addr[12] = 0xFF;
 310
 311   CopyMem (&MulticastAddr->Addr[13], &Ip6Addr->Addr[13], 3);
 312 }
 313
 314 /**
 315   Insert a node IP6_ADDRESS_INFO to an IP6 interface.
 316
 317   @param[in, out]  IpIf             Points to an IP6 interface.
 318   @param[in]       AddrInfo         Points to IP6_ADDRESS_INFO
 319
 320 **/
 321 VOID
 322 Ip6AddAddr (
 323   IN OUT IP6_INTERFACE *IpIf,
 324   IN IP6_ADDRESS_INFO  *AddrInfo
 325   )
 326 {
 327   InsertHeadList (&IpIf->AddressList, &AddrInfo->Link);
 328   IpIf->AddressCount++;
 329 }
 330
 331 /**
 332   Callback function which provided by user to remove one node in NetDestroyLinkList process.
 333
 334   @param[in]    Entry           The entry to be removed.
 335   @param[in]    Context         Pointer to the callback context corresponds to the Context in NetDestroyLinkList.
 336
 337   @retval EFI_SUCCESS           The entry has been removed successfully.
 338   @retval Others                Fail to remove the entry.
 339
 340 **/
 341 EFI_STATUS
 342 EFIAPI
 343 Ip6DestroyChildEntryByAddr (
 344   IN LIST_ENTRY         *Entry,
 345   IN VOID               *Context
 346   )
 347 {
 348   IP6_PROTOCOL                  *Instance;
 349   EFI_SERVICE_BINDING_PROTOCOL  *ServiceBinding;
 350   EFI_IPv6_ADDRESS              *Address;
 351
 352   Instance = NET_LIST_USER_STRUCT_S (Entry, IP6_PROTOCOL, Link, IP6_PROTOCOL_SIGNATURE);
 353   ServiceBinding = ((IP6_DESTROY_CHILD_BY_ADDR_CALLBACK_CONTEXT*) Context)->ServiceBinding;
 354   Address = ((IP6_DESTROY_CHILD_BY_ADDR_CALLBACK_CONTEXT*) Context)->Address;
 355
 356   if ((Instance->State == IP6_STATE_CONFIGED) && EFI_IP6_EQUAL (&Instance->ConfigData.StationAddress, Address)) {
 357     return ServiceBinding->DestroyChild (ServiceBinding, Instance->Handle);
 358   }
 359
 360   return EFI_SUCCESS;
 361 }
 362
 363 /**
 364   Destroy the IP instance if its StationAddress is removed. It is the help function
 365   for Ip6RemoveAddr().
 366
 367   @param[in, out]  IpSb             Points to an IP6 service binding instance.
 368   @param[in]       Address          The to be removed address
 369
 370 **/
 371 VOID
 372 Ip6DestroyInstanceByAddress (
 373   IN OUT IP6_SERVICE   *IpSb,
 374   IN EFI_IPv6_ADDRESS  *Address
 375   )
 376 {
 377   LIST_ENTRY                    *List;
 378   IP6_DESTROY_CHILD_BY_ADDR_CALLBACK_CONTEXT  Context;
 379
 380   NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
 381
 382   List = &IpSb->Children;
 383   Context.ServiceBinding = &IpSb->ServiceBinding;
 384   Context.Address = Address;
 385   NetDestroyLinkList (
 386     List,
 387     Ip6DestroyChildEntryByAddr,
 388     &Context,
 389     NULL
 390     );
 391 }
 392
 393 /**
 394   Remove the IPv6 address from the address list node points to IP6_ADDRESS_INFO.
 395
 396   This function removes the matching IPv6 addresses from the address list and
 397   adjusts the address count of the address list. If IpSb is not NULL, this function
 398   calls Ip6LeaveGroup to see whether it should call Mnp->Groups() to remove the
 399   its solicited-node multicast MAC address from the filter list and sends out
 400   a Multicast Listener Done. If Prefix is NULL, all address in the address list
 401   will be removed. If Prefix is not NULL, the address that matching the Prefix
 402   with PrefixLength in the address list will be removed.
 403
 404   @param[in]       IpSb             NULL or points to IP6 service binding instance.
 405   @param[in, out]  AddressList      Address list array.
 406   @param[in, out]  AddressCount     The count of addresses in address list array.
 407   @param[in]       Prefix           NULL or an IPv6 address prefix.
 408   @param[in]       PrefixLength     The length of Prefix.
 409
 410   @retval    EFI_SUCCESS            The operation completed successfully.
 411   @retval    EFI_NOT_FOUND          The address matching the Prefix with PrefixLength
 412                                     cannot be found in the address list.
 413   @retval    EFI_INVALID_PARAMETER  Any input parameter is invalid.
 414
 415 **/
 416 EFI_STATUS
 417 Ip6RemoveAddr (
 418   IN IP6_SERVICE       *IpSb          OPTIONAL,
 419   IN OUT LIST_ENTRY    *AddressList,
 420   IN OUT UINT32        *AddressCount,
 421   IN EFI_IPv6_ADDRESS  *Prefix        OPTIONAL,
 422   IN UINT8             PrefixLength
 423   )
 424 {
 425   EFI_STATUS           Status;
 426   LIST_ENTRY           *Entry;
 427   LIST_ENTRY           *Next;
 428   IP6_ADDRESS_INFO     *AddrInfo;
 429   EFI_IPv6_ADDRESS     SnMCastAddr;
 430
 431   if (IsListEmpty (AddressList) || *AddressCount < 1 || PrefixLength > IP6_PREFIX_MAX) {
 432     return EFI_INVALID_PARAMETER;
 433   }
 434
 435   Status = EFI_NOT_FOUND;
 436
 437   NET_LIST_FOR_EACH_SAFE (Entry, Next, AddressList) {
 438     AddrInfo = NET_LIST_USER_STRUCT_S (Entry, IP6_ADDRESS_INFO, Link, IP6_ADDR_INFO_SIGNATURE);
 439
 440     if (Prefix == NULL ||
 441         (PrefixLength == 128 && EFI_IP6_EQUAL (Prefix, &AddrInfo->Address)) ||
 442         (PrefixLength == AddrInfo->PrefixLength && NetIp6IsNetEqual (Prefix, &AddrInfo->Address, PrefixLength))
 443         ) {
 444       if (IpSb != NULL) {
 445         NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
 446         Ip6CreateSNMulticastAddr (&AddrInfo->Address, &SnMCastAddr);
 447         Ip6LeaveGroup (IpSb, &SnMCastAddr);
 448
 449         //
 450         // Destroy any instance who is using the dying address as the source address.
 451         //
 452         Ip6DestroyInstanceByAddress (IpSb, &AddrInfo->Address);
 453       }
 454
 455       RemoveEntryList (Entry);
 456       FreePool (AddrInfo);
 457       (*AddressCount)--;
 458
 459       Status = EFI_SUCCESS;
 460     }
 461   }
 462
 463   return Status;
 464 }
 465
 466 /**
 467   Check whether the incoming Ipv6 address is a solicited-node multicast address.
 468
 469   @param[in]  Ip6               Ip6 address, in network order.
 470
 471   @retval TRUE                  Yes, solicited-node multicast address
 472   @retval FALSE                 No
 473
 474 **/
 475 BOOLEAN
 476 Ip6IsSNMulticastAddr (
 477   IN EFI_IPv6_ADDRESS *Ip6
 478   )
 479 {
 480   EFI_IPv6_ADDRESS    Sn;
 481   BOOLEAN             Flag;
 482
 483   Ip6CreateSNMulticastAddr (Ip6, &Sn);
 484   Flag = FALSE;
 485
 486   if (CompareMem (Sn.Addr, Ip6->Addr, 13) == 0) {
 487     Flag = TRUE;
 488   }
 489
 490   return Flag;
 491 }
 492
 493 /**
 494   Check whether the incoming IPv6 address is one of the maintained addresses in
 495   the IP6 service binding instance.
 496
 497   @param[in]  IpSb              Points to a IP6 service binding instance.
 498   @param[in]  Address           The IP6 address to be checked.
 499   @param[out] Interface         If not NULL, output the IP6 interface which
 500                                 maintains the Address.
 501   @param[out] AddressInfo       If not NULL, output the IP6 address information
 502                                 of the Address.
 503
 504   @retval TRUE                  Yes, it is one of the maintained address.
 505   @retval FALSE                 No, it is not one of the maintained address.
 506
 507 **/
 508 BOOLEAN
 509 Ip6IsOneOfSetAddress (
 510   IN  IP6_SERVICE           *IpSb,
 511   IN  EFI_IPv6_ADDRESS      *Address,
 512   OUT IP6_INTERFACE         **Interface   OPTIONAL,
 513   OUT IP6_ADDRESS_INFO      **AddressInfo OPTIONAL
 514   )
 515 {
 516   LIST_ENTRY                *Entry;
 517   LIST_ENTRY                *Entry2;
 518   IP6_INTERFACE             *IpIf;
 519   IP6_ADDRESS_INFO          *TmpAddressInfo;
 520
 521   //
 522   // Check link-local address first
 523   //
 524   if (IpSb->LinkLocalOk && EFI_IP6_EQUAL (&IpSb->LinkLocalAddr, Address)) {
 525     if (Interface != NULL) {
 526       *Interface = IpSb->DefaultInterface;
 527     }
 528
 529     if (AddressInfo != NULL) {
 530       *AddressInfo = NULL;
 531     }
 532
 533     return TRUE;
 534   }
 535
 536   NET_LIST_FOR_EACH (Entry, &IpSb->Interfaces) {
 537     IpIf = NET_LIST_USER_STRUCT_S (Entry, IP6_INTERFACE, Link, IP6_INTERFACE_SIGNATURE);
 538
 539     NET_LIST_FOR_EACH (Entry2, &IpIf->AddressList) {
 540       TmpAddressInfo = NET_LIST_USER_STRUCT_S (Entry2, IP6_ADDRESS_INFO, Link, IP6_ADDR_INFO_SIGNATURE);
 541
 542       if (EFI_IP6_EQUAL (&TmpAddressInfo->Address, Address)) {
 543         if (Interface != NULL) {
 544           *Interface = IpIf;
 545         }
 546
 547         if (AddressInfo != NULL) {
 548           *AddressInfo = TmpAddressInfo;
 549         }
 550
 551         return TRUE;
 552       }
 553     }
 554   }
 555
 556   return FALSE;
 557 }
 558
 559 /**
 560   Check whether the incoming MAC address is valid.
 561
 562   @param[in]  IpSb              Points to a IP6 service binding instance.
 563   @param[in]  LinkAddress       The MAC address.
 564
 565   @retval TRUE                  Yes, it is valid.
 566   @retval FALSE                 No, it is not valid.
 567
 568 **/
 569 BOOLEAN
 570 Ip6IsValidLinkAddress (
 571   IN  IP6_SERVICE      *IpSb,
 572   IN  EFI_MAC_ADDRESS  *LinkAddress
 573   )
 574 {
 575   UINT32               Index;
 576
 577   //
 578   // TODO: might be updated later to be more acceptable.
 579   //
 580   for (Index = IpSb->SnpMode.HwAddressSize; Index < sizeof (EFI_MAC_ADDRESS); Index++) {
 581     if (LinkAddress->Addr[Index] != 0) {
 582       return FALSE;
 583     }
 584   }
 585
 586   return TRUE;
 587 }
 588
 589 /**
 590   Copy the PrefixLength bits from Src to Dest.
 591
 592   @param[out] Dest              A pointer to the buffer to copy to.
 593   @param[in]  Src               A pointer to the buffer to copy from.
 594   @param[in]  PrefixLength      The number of bits to copy.
 595
 596 **/
 597 VOID
 598 Ip6CopyAddressByPrefix (
 599   OUT EFI_IPv6_ADDRESS *Dest,
 600   IN  EFI_IPv6_ADDRESS *Src,
 601   IN  UINT8            PrefixLength
 602   )
 603 {
 604   UINT8 Byte;
 605   UINT8 Bit;
 606   UINT8 Mask;
 607
 608   ASSERT (Dest != NULL && Src != NULL);
 609   ASSERT (PrefixLength <= IP6_PREFIX_MAX);
 610
 611   Byte = (UINT8) (PrefixLength / 8);
 612   Bit  = (UINT8) (PrefixLength % 8);
 613
 614   ZeroMem (Dest, sizeof (EFI_IPv6_ADDRESS));
 615
 616   CopyMem (Dest, Src, Byte);
 617
 618   if (Bit > 0) {
 619     Mask = (UINT8) (0xFF << (8 - Bit));
 620     ASSERT (Byte < 16);
 621     Dest->Addr[Byte] = (UINT8) (Src->Addr[Byte] & Mask);
 622   }
 623 }
 624
 625 /**
 626   Get the MAC address for a multicast IP address. Call
 627   Mnp's McastIpToMac to find the MAC address instead of
 628   hard-coding the NIC to be Ethernet.
 629
 630   @param[in]  Mnp                   The Mnp instance to get the MAC address.
 631   @param[in]  Multicast             The multicast IP address to translate.
 632   @param[out] Mac                   The buffer to hold the translated address.
 633
 634   @retval EFI_SUCCESS               The multicast IP successfully
 635                                     translated to a multicast MAC address.
 636   @retval Other                     The address is not converted because an error occurred.
 637
 638 **/
 639 EFI_STATUS
 640 Ip6GetMulticastMac (
 641   IN  EFI_MANAGED_NETWORK_PROTOCOL *Mnp,
 642   IN  EFI_IPv6_ADDRESS             *Multicast,
 643   OUT EFI_MAC_ADDRESS              *Mac
 644   )
 645 {
 646   EFI_IP_ADDRESS        EfiIp;
 647
 648   IP6_COPY_ADDRESS (&EfiIp.v6, Multicast);
 649
 650   return Mnp->McastIpToMac (Mnp, TRUE, &EfiIp, Mac);
 651 }
 652
 653 /**
 654   Convert the multibyte field in IP header's byter order.
 655   In spite of its name, it can also be used to convert from
 656   host to network byte order.
 657
 658   @param[in, out]  Head                  The IP head to convert.
 659
 660   @return Point to the converted IP head.
 661
 662 **/
 663 EFI_IP6_HEADER *
 664 Ip6NtohHead (
 665   IN OUT EFI_IP6_HEADER *Head
 666   )
 667 {
 668   Head->FlowLabelL    = NTOHS (Head->FlowLabelL);
 669   Head->PayloadLength = NTOHS (Head->PayloadLength);
 670
 671   return Head;
 672 }
 673