/** @file
  Dhcp6 internal data structure and definition declaration.

  Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#ifndef __EFI_DHCP6_IMPL_H__
#define __EFI_DHCP6_IMPL_H__


#include <Uefi.h>

#include <Protocol/Dhcp6.h>
#include <Protocol/Udp6.h>
#include <Protocol/ServiceBinding.h>
#include <Protocol/DriverBinding.h>

#include <Library/UdpIoLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/BaseLib.h>
#include <Library/NetLib.h>


typedef struct _DHCP6_IA_CB    DHCP6_IA_CB;
typedef struct _DHCP6_INF_CB   DHCP6_INF_CB;
typedef struct _DHCP6_TX_CB    DHCP6_TX_CB;
typedef struct _DHCP6_SERVICE  DHCP6_SERVICE;
typedef struct _DHCP6_INSTANCE DHCP6_INSTANCE;

#include "Dhcp6Utility.h"
#include "Dhcp6Io.h"
#include "Dhcp6Driver.h"

#define DHCP6_SERVICE_SIGNATURE   SIGNATURE_32 ('D', 'H', '6', 'S')
#define DHCP6_INSTANCE_SIGNATURE  SIGNATURE_32 ('D', 'H', '6', 'I')

//
// Transmit parameters of solicit message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_SOL_MAX_DELAY       1
#define DHCP6_SOL_IRT             1
#define DHCP6_SOL_MRC             0
#define DHCP6_SOL_MRT             120
#define DHCP6_SOL_MRD             0
//
// Transmit parameters of request message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_REQ_IRT             1
#define DHCP6_REQ_MRC             10
#define DHCP6_REQ_MRT             30
#define DHCP6_REQ_MRD             0
//
// Transmit parameters of confirm message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_CNF_MAX_DELAY       1
#define DHCP6_CNF_IRT             1
#define DHCP6_CNF_MRC             0
#define DHCP6_CNF_MRT             4
#define DHCP6_CNF_MRD             10
//
// Transmit parameters of renew message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_REN_IRT             10
#define DHCP6_REN_MRC             0
#define DHCP6_REN_MRT             600
#define DHCP6_REN_MRD             0
//
// Transmit parameters of rebind message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_REB_IRT             10
#define DHCP6_REB_MRC             0
#define DHCP6_REB_MRT             600
#define DHCP6_REB_MRD             0
//
// Transmit parameters of information request message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_INF_MAX_DELAY       1
#define DHCP6_INF_IRT             1
#define DHCP6_INF_MRC             0
#define DHCP6_INF_MRT             120
#define DHCP6_INF_MRD             0
//
// Transmit parameters of release message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_REL_IRT             1
#define DHCP6_REL_MRC             5
#define DHCP6_REL_MRT             0
#define DHCP6_REL_MRD             0
//
// Transmit parameters of decline message, refers to section-5.5 of rfc-3315.
//
#define DHCP6_DEC_IRT             1
#define DHCP6_DEC_MRC             5
#define DHCP6_DEC_MRT             0
#define DHCP6_DEC_MRD             0

#define DHCP6_PACKET_ALL          0
#define DHCP6_PACKET_STATEFUL     1
#define DHCP6_PACKET_STATELESS    2

#define DHCP6_BASE_PACKET_SIZE    1024

#define DHCP6_PORT_CLIENT         546
#define DHCP6_PORT_SERVER         547

#define DHCP6_INSTANCE_FROM_THIS(Instance) CR ((Instance), DHCP6_INSTANCE, Dhcp6, DHCP6_INSTANCE_SIGNATURE)
#define DHCP6_SERVICE_FROM_THIS(Service)   CR ((Service), DHCP6_SERVICE, ServiceBinding, DHCP6_SERVICE_SIGNATURE)

extern EFI_IPv6_ADDRESS           mAllDhcpRelayAndServersAddress;
extern EFI_IPv6_ADDRESS           mAllDhcpServersAddress;
extern EFI_DHCP6_PROTOCOL         gDhcp6ProtocolTemplate;

//
// Enumeration of Dhcp6 message type, refers to section-5.3 of rfc-3315.
//
typedef enum {
  Dhcp6MsgSolicit               = 1,
  Dhcp6MsgAdvertise             = 2,
  Dhcp6MsgRequest               = 3,
  Dhcp6MsgConfirm               = 4,
  Dhcp6MsgRenew                 = 5,
  Dhcp6MsgRebind                = 6,
  Dhcp6MsgReply                 = 7,
  Dhcp6MsgRelease               = 8,
  Dhcp6MsgDecline               = 9,
  Dhcp6MsgReconfigure           = 10,
  Dhcp6MsgInfoRequest           = 11
} DHCP6_MSG_TYPE;

//
// Enumeration of option code in Dhcp6 packet, refers to section-24.3 of rfc-3315.
//
typedef enum {
  Dhcp6OptClientId              = 1,
  Dhcp6OptServerId              = 2,
  Dhcp6OptIana                  = 3,
  Dhcp6OptIata                  = 4,
  Dhcp6OptIaAddr                = 5,
  Dhcp6OptRequestOption         = 6,
  Dhcp6OptPreference            = 7,
  Dhcp6OptElapsedTime           = 8,
  Dhcp6OptReplayMessage         = 9,
  Dhcp6OptAuthentication        = 11,
  Dhcp6OptServerUnicast         = 12,
  Dhcp6OptStatusCode            = 13,
  Dhcp6OptRapidCommit           = 14,
  Dhcp6OptUserClass             = 15,
  Dhcp6OptVendorClass           = 16,
  Dhcp6OptVendorInfo            = 17,
  Dhcp6OptInterfaceId           = 18,
  Dhcp6OptReconfigMessage       = 19,
  Dhcp6OptReconfigureAccept     = 20
} DHCP6_OPT_CODE;

//
// Enumeration of status code recorded by IANA, refers to section-24.4 of rfc-3315.
//
typedef enum {
  Dhcp6StsSuccess               = 0,
  Dhcp6StsUnspecFail            = 1,
  Dhcp6StsNoAddrsAvail          = 2,
  Dhcp6StsNoBinding             = 3,
  Dhcp6StsNotOnLink             = 4,
  Dhcp6StsUseMulticast          = 5
} DHCP6_STS_CODE;

//
// Enumeration of Duid type recorded by IANA, refers to section-24.5 of rfc-3315.
//
typedef enum {
  Dhcp6DuidTypeLlt              = 1,
  Dhcp6DuidTypeEn               = 2,
  Dhcp6DuidTypeLl               = 3,
  Dhcp6DuidTypeUuid             = 4
} DHCP6_DUID_TYPE;

//
// Control block for each IA.
//
struct _DHCP6_IA_CB {
  EFI_DHCP6_IA                  *Ia;
  UINT32                        T1;
  UINT32                        T2;
  UINT32                        AllExpireTime;
  UINT32                        LeaseTime;
};

//
// Control block for each transmitted message.
//
struct _DHCP6_TX_CB {
  LIST_ENTRY                    Link;
  UINT32                        Xid;
  EFI_DHCP6_PACKET              *TxPacket;
  EFI_DHCP6_RETRANSMISSION      RetryCtl;
  UINT32                        RetryCnt;
  UINT32                        RetryExp;
  UINT32                        RetryLos;
  UINT32                        TickTime;
  UINT16                        *Elapsed;
  BOOLEAN                       SolicitRetry;
};

//
// Control block for each info-request message.
//
struct _DHCP6_INF_CB {
  LIST_ENTRY                    Link;
  UINT32                        Xid;
  EFI_DHCP6_INFO_CALLBACK       ReplyCallback;
  VOID                          *CallbackContext;
  EFI_EVENT                     TimeoutEvent;
};

//
// Control block for Dhcp6 instance, it's per configuration data.
//
struct _DHCP6_INSTANCE {
  UINT32                        Signature;
  EFI_HANDLE                    Handle;
  DHCP6_SERVICE                 *Service;
  LIST_ENTRY                    Link;
  EFI_DHCP6_PROTOCOL            Dhcp6;
  EFI_EVENT                     Timer;
  EFI_DHCP6_CONFIG_DATA         *Config;
  EFI_DHCP6_IA                  *CacheIa;
  DHCP6_IA_CB                   IaCb;
  LIST_ENTRY                    TxList;
  LIST_ENTRY                    InfList;
  EFI_DHCP6_PACKET              *AdSelect;
  UINT8                         AdPref;
  EFI_IPv6_ADDRESS              *Unicast;
  EFI_STATUS                    UdpSts;
  BOOLEAN                       InDestory;
  BOOLEAN                       MediaPresent;
  UINT64                        StartTime;
};

//
// Control block for Dhcp6 service, it's per Nic handle.
//
struct _DHCP6_SERVICE {
  UINT32                        Signature;
  EFI_HANDLE                    Controller;
  EFI_HANDLE                    Image;
  EFI_SERVICE_BINDING_PROTOCOL  ServiceBinding;
  EFI_SIMPLE_NETWORK_PROTOCOL   *Snp;
  EFI_DHCP6_DUID                *ClientId;
  UDP_IO                        *UdpIo;
  UINT32                        Xid;
  LIST_ENTRY                    Child;
  UINTN                         NumOfChild;
  BOOLEAN                       InDestory;
};

/**
  Starts the DHCPv6 standard S.A.R.R. process.

  The Start() function starts the DHCPv6 standard process. This function can
  be called only when the state of Dhcp6 instance is in the Dhcp6Init state.
  If the DHCP process completes successfully, the state of the Dhcp6 instance
  will be transferred through Dhcp6Selecting and Dhcp6Requesting to the
  Dhcp6Bound state.
  Refer to rfc-3315 for precise state transitions during this process. At the
  time when each event occurs in this process, the callback function that was set
  by EFI_DHCP6_PROTOCOL.Configure() will be called and the user can take this
  opportunity to control the process.

  @param[in]  This              The pointer to Dhcp6 protocol.

  @retval EFI_SUCCESS           The DHCPv6 standard process has started, or it
                                completed when CompletionEvent was NULL.
  @retval EFI_ACCESS_DENIED     The EFI DHCPv6 Child instance hasn't been configured.
  @retval EFI_INVALID_PARAMETER This is NULL.
  @retval EFI_OUT_OF_RESOURCES  Required system resources could not be allocated.
  @retval EFI_TIMEOUT           The DHCPv6 configuration process failed because no
                                response was received from the server within the
                                specified timeout value.
  @retval EFI_ABORTED           The user aborted the DHCPv6 process.
  @retval EFI_ALREADY_STARTED   Some other Dhcp6 instance already started the DHCPv6
                                standard process.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Start (
  IN EFI_DHCP6_PROTOCOL        *This
  );

/**
  Stops the DHCPv6 standard S.A.R.R. process.

  The Stop() function is used to stop the DHCPv6 standard process. After this
  function is called successfully, the state of Dhcp6 instance is transferred
  into the Dhcp6Init. EFI_DHCP6_PROTOCOL.Configure() needs to be called
  before DHCPv6 standard process can be started again. This function can be
  called when the Dhcp6 instance is in any state.

  @param[in]  This              The pointer to the Dhcp6 protocol.

  @retval EFI_SUCCESS           The Dhcp6 instance is now in the Dhcp6Init state.
  @retval EFI_INVALID_PARAMETER This is NULL.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Stop (
  IN EFI_DHCP6_PROTOCOL        *This
  );

/**
  Returns the current operating mode data for the Dhcp6 instance.

  The GetModeData() function returns the current operating mode and
  cached data packet for the Dhcp6 instance.

  @param[in]  This              The pointer to the Dhcp6 protocol.
  @param[out] Dhcp6ModeData     The pointer to the Dhcp6 mode data.
  @param[out] Dhcp6ConfigData   The pointer to the Dhcp6 configure data.

  @retval EFI_SUCCESS           The mode data was returned.
  @retval EFI_INVALID_PARAMETER This is NULL.
  @retval EFI_ACCESS_DENIED     The EFI DHCPv6 Protocol instance has not
                                been configured when Dhcp6ConfigData is
                                not NULL.
**/
EFI_STATUS
EFIAPI
EfiDhcp6GetModeData (
  IN  EFI_DHCP6_PROTOCOL       *This,
  OUT EFI_DHCP6_MODE_DATA      *Dhcp6ModeData      OPTIONAL,
  OUT EFI_DHCP6_CONFIG_DATA    *Dhcp6ConfigData    OPTIONAL
  );

/**
  Initializes, changes, or resets the operational settings for the Dhcp6 instance.

  The Configure() function is used to initialize or clean up the configuration
  data of the Dhcp6 instance:
  - When Dhcp6CfgData is not NULL and Configure() is called successfully, the
    configuration data will be initialized in the Dhcp6 instance and the state
    of the configured IA will be transferred into Dhcp6Init.
  - When Dhcp6CfgData is NULL and Configure() is called successfully, the
    configuration data will be cleaned up and no IA will be associated with
    the Dhcp6 instance.
  To update the configuration data for an Dhcp6 instance, the original data
  must be cleaned up before setting the new configuration data.

  @param[in]  This                   The pointer to the Dhcp6 protocol
  @param[in]  Dhcp6CfgData           The pointer to the EFI_DHCP6_CONFIG_DATA.

  @retval EFI_SUCCESS           The Dhcp6 is configured successfully with the
                                Dhcp6Init state, or cleaned up the original
                                configuration setting.
  @retval EFI_ACCESS_DENIED     The Dhcp6 instance has been already configured
                                when Dhcp6CfgData is not NULL.
                                The Dhcp6 instance has already started the
                                DHCPv6 S.A.R.R when Dhcp6CfgData is NULL.
  @retval EFI_INVALID_PARAMETER Some of the parameter is invalid.
  @retval EFI_OUT_OF_RESOURCES  Required system resources could not be allocated.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Configure (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN EFI_DHCP6_CONFIG_DATA     *Dhcp6CfgData    OPTIONAL
  );

/**
  Request configuration information without the assignment of any
  Ia addresses of the client.

  The InfoRequest() function is used to request configuration information
  without the assignment of any IPv6 address of the client. Client sends
  out Information Request packet to obtain the required configuration
  information, and DHCPv6 server responds with Reply packet containing
  the information for the client. The received Reply packet will be passed
  to the user by ReplyCallback function. If user returns EFI_NOT_READY from
  ReplyCallback, the Dhcp6 instance will continue to receive other Reply
  packets unless timeout according to the Retransmission parameter.
  Otherwise, the Information Request exchange process will be finished
  successfully if user returns EFI_SUCCESS from ReplyCallback.

  @param[in]  This              The pointer to the Dhcp6 protocol.
  @param[in]  SendClientId      If TRUE, the DHCPv6 protocol instance will build Client
                                Identifier option and include it into Information Request
                                packet. Otherwise, Client Identifier option will not be included.
  @param[in]  OptionRequest     The pointer to the buffer of option request options.
  @param[in]  OptionCount       The option number in the OptionList.
  @param[in]  OptionList        The list of appended options.
  @param[in]  Retransmission    The pointer to the retransmission of the message.
  @param[in]  TimeoutEvent      The event of timeout.
  @param[in]  ReplyCallback     The callback function when a reply was received.
  @param[in]  CallbackContext   The pointer to the parameter passed to the callback.

  @retval EFI_SUCCESS           The DHCPv6 information request exchange process
                                completed when TimeoutEvent is NULL. Information
                                Request packet has been sent to DHCPv6 server when
                                TimeoutEvent is not NULL.
  @retval EFI_NO_RESPONSE       The DHCPv6 information request exchange process failed
                                because of no response, or not all requested-options
                                are responded to by DHCPv6 servers when Timeout happened.
  @retval EFI_ABORTED           The DHCPv6 information request exchange process was aborted
                                by the user.
  @retval EFI_INVALID_PARAMETER Some parameter is NULL.
  @retval EFI_OUT_OF_RESOURCES  Required system resources could not be allocated.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6InfoRequest (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN BOOLEAN                   SendClientId,
  IN EFI_DHCP6_PACKET_OPTION   *OptionRequest,
  IN UINT32                    OptionCount,
  IN EFI_DHCP6_PACKET_OPTION   *OptionList[]    OPTIONAL,
  IN EFI_DHCP6_RETRANSMISSION  *Retransmission,
  IN EFI_EVENT                 TimeoutEvent     OPTIONAL,
  IN EFI_DHCP6_INFO_CALLBACK   ReplyCallback,
  IN VOID                      *CallbackContext OPTIONAL
  );

/**
  Manually extend the valid and preferred lifetimes for the IPv6 addresses
  of the configured IA and update other configuration parameters by sending
  Renew or Rebind packet.

  The RenewRebind() function is used to manually extend the valid and preferred
  lifetimes for the IPv6 addresses of the configured IA and update other
  configuration parameters by sending a Renew or Rebind packet.
  - When RebindRequest is FALSE and the state of the configured IA is Dhcp6Bound,
    it will send Renew packet to the previously DHCPv6 server and transfer the
    state of the configured IA to Dhcp6Renewing. If valid Reply packet received,
    the state transfers to Dhcp6Bound and the valid and preferred timer restarts.
    If fails, the state transfers to Dhcp6Bound but the timer continues.
  - When RebindRequest is TRUE and the state of the configured IA is Dhcp6Bound,
    it will send a Rebind packet. If a valid Reply packet is received, the state transfers
    to Dhcp6Bound, and the valid and preferred timer restarts. If it fails, the state
    transfers to Dhcp6Init, and the IA can't be used.

  @param[in]  This              The pointer to the Dhcp6 protocol.
  @param[in]  RebindRequest     If TRUE, Rebind packet will be sent and enter Dhcp6Rebinding state.
                                Otherwise, Renew packet will be sent and enter Dhcp6Renewing state.

  @retval EFI_SUCCESS           The DHCPv6 renew/rebind exchange process
                                completed and at least one IPv6 address of the
                                configured IA was bound again when
                                EFI_DHCP6_CONFIG_DATA.IaInfoEvent was NULL.
                                The EFI DHCPv6 Protocol instance has sent Renew
                                or Rebind packet when
                                EFI_DHCP6_CONFIG_DATA.IaInfoEvent is not NULL.
  @retval EFI_ACCESS_DENIED     The Dhcp6 instance hasn't been configured, or the
                                state of the configured IA is not in Dhcp6Bound.
  @retval EFI_ALREADY_STARTED   The state of the configured IA has already entered
                                Dhcp6Renewing when RebindRequest is FALSE.
                                The state of the configured IA has already entered
                                Dhcp6Rebinding when RebindRequest is TRUE.
  @retval EFI_ABORTED           The DHCPv6 renew/rebind exchange process aborted
                                by user.
  @retval EFI_NO_RESPONSE       The DHCPv6 renew/rebind exchange process failed
                                because of no response.
  @retval EFI_NO_MAPPING        No IPv6 address has been bound to the configured
                                IA after the DHCPv6 renew/rebind exchange process.
  @retval EFI_INVALID_PARAMETER Some parameter is NULL.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6RenewRebind (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN BOOLEAN                   RebindRequest
  );

/**
  Inform that one or more addresses assigned by a server are already
  in use by another node.

  The Decline() function is used to manually decline the assignment of
  IPv6 addresses, which have been already used by another node. If all
  IPv6 addresses of the configured IA are declined through this function,
  the state of the IA will switch through Dhcp6Declining to Dhcp6Init.
  Otherwise, the state of the IA will restore to Dhcp6Bound after the
  declining process. The Decline() can only be called when the IA is in
  Dhcp6Bound state. If the EFI_DHCP6_CONFIG_DATA.IaInfoEvent is NULL,
  this function is a blocking operation. It will return after the
  declining process finishes, or aborted by user.

  @param[in]  This              The pointer to the Dhcp6 protocol.
  @param[in]  AddressCount      The number of declining addresses.
  @param[in]  Addresses         The pointer to the buffer stored the declining
                                addresses.

  @retval EFI_SUCCESS           The DHCPv6 decline exchange process completed
                                when EFI_DHCP6_CONFIG_DATA.IaInfoEvent was NULL.
                                The Dhcp6 instance has sent Decline packet when
                                EFI_DHCP6_CONFIG_DATA.IaInfoEvent is not NULL.
  @retval EFI_ACCESS_DENIED     The Dhcp6 instance hasn't been configured, or the
                                state of the configured IA is not in Dhcp6Bound.
  @retval EFI_ABORTED           The DHCPv6 decline exchange process was aborted by the user.
  @retval EFI_NOT_FOUND         Any specified IPv6 address is not correlated with
                                the configured IA for this instance.
  @retval EFI_INVALID_PARAMETER Some parameter is NULL.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Decline (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN UINT32                    AddressCount,
  IN EFI_IPv6_ADDRESS          *Addresses
  );

/**
  Release one or more addresses associated with the configured Ia
  for the current instance.

  The Release() function is used to manually release the one or more
  IPv6 address. If AddressCount is zero, it will release all IPv6
  addresses of the configured IA. If all IPv6 addresses of the IA are
  released through this function, the state of the IA will switch
  through Dhcp6Releasing to Dhcp6Init, otherwise, the state of the
  IA will restore to Dhcp6Bound after the releasing process.
  The Release() can only be called when the IA is in a Dhcp6Bound state.
  If the EFI_DHCP6_CONFIG_DATA.IaInfoEvent is NULL, the function is
  a blocking operation. It will return after the releasing process
  finishes, or aborted by user.

  @param[in]  This              The pointer to the Dhcp6 protocol.
  @param[in]  AddressCount      The number of releasing addresses.
  @param[in]  Addresses         The pointer to the buffer stored the releasing
                                addresses.
  @retval EFI_SUCCESS           The DHCPv6 release exchange process has
                                completed when EFI_DHCP6_CONFIG_DATA.IaInfoEvent
                                is NULL. The Dhcp6 instance has sent Release
                                packet when EFI_DHCP6_CONFIG_DATA.IaInfoEvent
                                is not NULL.
  @retval EFI_ACCESS_DENIED     The Dhcp6 instance hasn't been configured, or the
                                state of the configured IA is not in Dhcp6Bound.
  @retval EFI_ABORTED           The DHCPv6 release exchange process was aborted by the user.
  @retval EFI_NOT_FOUND         Any specified IPv6 address is not correlated with
                                the configured IA for this instance.
  @retval EFI_INVALID_PARAMETER Some parameter is NULL.
  @retval EFI_DEVICE_ERROR      An unexpected system or network error occurred.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Release (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN UINT32                    AddressCount,
  IN EFI_IPv6_ADDRESS          *Addresses
  );

/**
  Parse the option data in the Dhcp6 packet.

  The Parse() function is used to retrieve the option list in the DHCPv6 packet.

  @param[in]      This              The pointer to the Dhcp6 protocol.
  @param[in]      Packet            The pointer to the Dhcp6 packet.
  @param[in, out] OptionCount       The number of option in the packet.
  @param[out]     PacketOptionList  The array of pointers to the each option in the packet.

  @retval EFI_SUCCESS           The packet was successfully parsed.
  @retval EFI_INVALID_PARAMETER Some parameter is NULL.
  @retval EFI_BUFFER_TOO_SMALL  *OptionCount is smaller than the number of options
                                that were found in the Packet.

**/
EFI_STATUS
EFIAPI
EfiDhcp6Parse (
  IN EFI_DHCP6_PROTOCOL        *This,
  IN EFI_DHCP6_PACKET          *Packet,
  IN OUT UINT32                *OptionCount,
  OUT EFI_DHCP6_PACKET_OPTION  *PacketOptionList[]  OPTIONAL
  );

#endif
