NetworkPkg/Dhcp4Dxe/Dhcp4Option.h - edk2 - Git at Google

 /** @file
   To validate, parse and process the DHCP options.

 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

 #ifndef __EFI_DHCP4_OPTION_H__
 #define __EFI_DHCP4_OPTION_H__

 ///
 /// DHCP option tags (types)
 ///

 #define DHCP_OPTION_MAGIC  0x63538263        // Network byte order
 #define DHCP_MAX_OPTIONS   256

 //
 // DHCP option types, this is used to validate the DHCP options.
 //
 #define DHCP_OPTION_SWITCH  1
 #define DHCP_OPTION_INT8    2
 #define DHCP_OPTION_INT16   3
 #define DHCP_OPTION_INT32   4
 #define DHCP_OPTION_IP      5
 #define DHCP_OPTION_IPPAIR  6

 //
 // Value of DHCP overload option
 //
 #define DHCP_OVERLOAD_FILENAME  1
 #define DHCP_OVERLOAD_SVRNAME   2
 #define DHCP_OVERLOAD_BOTH      3

 ///
 /// The DHCP option structure. This structure extends the EFI_DHCP_OPTION
 /// structure to support options longer than 255 bytes, such as classless route.
 ///
 typedef struct {
   UINT8     Tag;
   UINT16    Len;
   UINT8     *Data;
 } DHCP_OPTION;

 ///
 /// Structures used to parse the DHCP options with RFC3396 support.
 ///
 typedef struct {
   UINT8     Index;
   UINT16    Offset;
 } DHCP_OPTION_COUNT;

 typedef struct {
   DHCP_OPTION_COUNT    *OpCount;
   DHCP_OPTION          *Options;
   UINT8                *Buf;
 } DHCP_OPTION_CONTEXT;

 ///
 /// The options that matters to DHCP driver itself. The user of
 /// DHCP clients may be interested in other options, such as
 /// classless route, who can parse the DHCP offer to get them.
 ///
 typedef struct {
   IP4_ADDR    NetMask;                // DHCP4_TAG_NETMASK
   IP4_ADDR    Router;                 // DHCP4_TAG_ROUTER, only the first router is used

   //
   // DHCP specific options
   //
   UINT8       DhcpType;               // DHCP4_TAG_MSG_TYPE
   UINT8       Overload;               // DHCP4_TAG_OVERLOAD
   IP4_ADDR    ServerId;               // DHCP4_TAG_SERVER_ID
   UINT32      Lease;                  // DHCP4_TAG_LEASE
   UINT32      T1;                     // DHCP4_TAG_T1
   UINT32      T2;                     // DHCP4_TAG_T2
 } DHCP_PARAMETER;

 ///
 /// Structure used to describe and validate the format of DHCP options.
 /// Type is the options' data type, such as DHCP_OPTION_INT8. MinOccur
 /// is the minimum occurrence of this data type. MaxOccur is defined
 /// similarly. If MaxOccur is -1, it means that there is no limit on the
 /// maximum occurrence. Alert tells whether DHCP client should further
 /// inspect the option to parse DHCP_PARAMETER.
 ///
 typedef struct {
   UINT8      Tag;
   INTN       Type;
   INTN       MinOccur;
   INTN       MaxOccur;
   BOOLEAN    Alert;
 } DHCP_OPTION_FORMAT;

 typedef
 EFI_STATUS
 (*DHCP_CHECK_OPTION) (
   IN UINT8  Tag,
   IN UINT8  Len,
   IN UINT8  *Data,
   IN VOID   *Context
   );

 /**
   Iterate through a DHCP message to visit each option. First inspect
   all the options in the OPTION field. Then if overloaded, inspect
   the options in FILENAME and SERVERNAME fields. One option may be
   encoded in several places. See RFC 3396 Encoding Long Options in DHCP

   @param[in]  Packet                 The DHCP packet to check the options for
   @param[in]  Check                  The callback function to be called for each option
                                      found
   @param[in]  Context                The opaque parameter for Check

   @retval EFI_SUCCESS            The DHCP packet's options are well formatted
   @retval EFI_INVALID_PARAMETER  The DHCP packet's options are not well formatted

 **/
 EFI_STATUS
 DhcpIterateOptions (
   IN  EFI_DHCP4_PACKET   *Packet,
   IN  DHCP_CHECK_OPTION  Check         OPTIONAL,
   IN  VOID               *Context
   );

 /**
   Validate the packet's options. If necessary, allocate
   and fill in the interested parameters.

   @param[in]  Packet                 The packet to validate the options
   @param[out] Para                   The variable to save the DHCP parameters.

   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory to validate the packet.
   @retval EFI_INVALID_PARAMETER  The options are mal-formatted
   @retval EFI_SUCCESS            The options are parsed into OptionPoint

 **/
 EFI_STATUS
 DhcpValidateOptions (
   IN  EFI_DHCP4_PACKET  *Packet,
   OUT DHCP_PARAMETER    **Para       OPTIONAL
   );

 /**
   Parse the options of a DHCP packet. It supports RFC 3396: Encoding
   Long Options in DHCP. That is, it will combine all the option value
   of all the occurrences of each option.
   A little bit of implementation:
   It adopts the "Key indexed counting" algorithm. First, it allocates
   an array of 256 DHCP_OPTION_COUNTs because DHCP option tag is encoded
   as a UINT8. It then iterates the DHCP packet to get data length of
   each option by calling DhcpIterOptions with DhcpGetOptionLen. Now, it
   knows the number of present options and their length. It allocates a
   array of DHCP_OPTION and a continuous buffer after the array to put
   all the options' data. Each option's data is pointed to by the Data
   field in DHCP_OPTION structure. At last, it call DhcpIterateOptions
   with DhcpFillOption to fill each option's data to its position in the
   buffer.

   @param[in]  Packet                 The DHCP packet to parse the options
   @param[out] Count                  The number of valid dhcp options present in the
                                      packet
   @param[out] OptionPoint            The array that contains the DHCP options. Caller
                                      should free it.

   @retval EFI_NOT_FOUND          Cannot find any option.
   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory to parse the packet.
   @retval EFI_INVALID_PARAMETER  The options are mal-formatted
   @retval EFI_SUCCESS            The options are parsed into OptionPoint

 **/
 EFI_STATUS
 DhcpParseOption (
   IN  EFI_DHCP4_PACKET  *Packet,
   OUT INTN              *Count,
   OUT DHCP_OPTION       **OptionPoint
   );

 /**
   Append an option to the memory, if the option is longer than
   255 bytes, splits it into several options.

   @param[out] Buf                    The buffer to append the option to
   @param[in]  Tag                    The option's tag
   @param[in]  DataLen                The length of the option's data
   @param[in]  Data                   The option's data

   @return The position to append the next option

 **/
 UINT8 *
 DhcpAppendOption (
   OUT UINT8   *Buf,
   IN  UINT8   Tag,
   IN  UINT16  DataLen,
   IN  UINT8   *Data
   );

 /**
   Build a new DHCP packet from a seed packet. Options may be deleted or
   appended. The caller should free the NewPacket when finished using it.

   @param[in]  SeedPacket             The seed packet to start with
   @param[in]  DeleteCount            The number of options to delete
   @param[in]  DeleteList             The options to delete from the packet
   @param[in]  AppendCount            The number of options to append
   @param[in]  AppendList             The options to append to the packet
   @param[out] NewPacket              The new packet, allocated and built by this
                                      function.

   @retval EFI_OUT_OF_RESOURCES   Failed to allocate memory
   @retval EFI_INVALID_PARAMETER  The options in SeekPacket are mal-formatted
   @retval EFI_SUCCESS            The packet is build.

 **/
 EFI_STATUS
 DhcpBuild (
   IN  EFI_DHCP4_PACKET         *SeedPacket,
   IN  UINT32                   DeleteCount,
   IN  UINT8                    *DeleteList     OPTIONAL,
   IN  UINT32                   AppendCount,
   IN  EFI_DHCP4_PACKET_OPTION  *AppendList[]   OPTIONAL,
   OUT EFI_DHCP4_PACKET         **NewPacket
   );

 #endif
	/** @file
	To validate, parse and process the DHCP options.

	Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
	SPDX-License-Identifier: BSD-2-Clause-Patent

	**/

	#ifndef __EFI_DHCP4_OPTION_H__
	#define __EFI_DHCP4_OPTION_H__

	///
	/// DHCP option tags (types)
	///

	#define DHCP_OPTION_MAGIC 0x63538263 // Network byte order
	#define DHCP_MAX_OPTIONS 256

	//
	// DHCP option types, this is used to validate the DHCP options.
	//
	#define DHCP_OPTION_SWITCH 1
	#define DHCP_OPTION_INT8 2
	#define DHCP_OPTION_INT16 3
	#define DHCP_OPTION_INT32 4
	#define DHCP_OPTION_IP 5
	#define DHCP_OPTION_IPPAIR 6

	//
	// Value of DHCP overload option
	//
	#define DHCP_OVERLOAD_FILENAME 1
	#define DHCP_OVERLOAD_SVRNAME 2
	#define DHCP_OVERLOAD_BOTH 3

	///
	/// The DHCP option structure. This structure extends the EFI_DHCP_OPTION
	/// structure to support options longer than 255 bytes, such as classless route.
	///
	typedef struct {
	UINT8 Tag;
	UINT16 Len;
	UINT8 *Data;
	} DHCP_OPTION;

	///
	/// Structures used to parse the DHCP options with RFC3396 support.
	///
	typedef struct {
	UINT8 Index;
	UINT16 Offset;
	} DHCP_OPTION_COUNT;

	typedef struct {
	DHCP_OPTION_COUNT *OpCount;
	DHCP_OPTION *Options;
	UINT8 *Buf;
	} DHCP_OPTION_CONTEXT;

	///
	/// The options that matters to DHCP driver itself. The user of
	/// DHCP clients may be interested in other options, such as
	/// classless route, who can parse the DHCP offer to get them.
	///
	typedef struct {
	IP4_ADDR NetMask; // DHCP4_TAG_NETMASK
	IP4_ADDR Router; // DHCP4_TAG_ROUTER, only the first router is used

	//
	// DHCP specific options
	//
	UINT8 DhcpType; // DHCP4_TAG_MSG_TYPE
	UINT8 Overload; // DHCP4_TAG_OVERLOAD
	IP4_ADDR ServerId; // DHCP4_TAG_SERVER_ID
	UINT32 Lease; // DHCP4_TAG_LEASE
	UINT32 T1; // DHCP4_TAG_T1
	UINT32 T2; // DHCP4_TAG_T2
	} DHCP_PARAMETER;

	///
	/// Structure used to describe and validate the format of DHCP options.
	/// Type is the options' data type, such as DHCP_OPTION_INT8. MinOccur
	/// is the minimum occurrence of this data type. MaxOccur is defined
	/// similarly. If MaxOccur is -1, it means that there is no limit on the
	/// maximum occurrence. Alert tells whether DHCP client should further
	/// inspect the option to parse DHCP_PARAMETER.
	///
	typedef struct {
	UINT8 Tag;
	INTN Type;
	INTN MinOccur;
	INTN MaxOccur;
	BOOLEAN Alert;
	} DHCP_OPTION_FORMAT;

	typedef
	EFI_STATUS
	(*DHCP_CHECK_OPTION) (
	IN UINT8 Tag,
	IN UINT8 Len,
	IN UINT8 *Data,
	IN VOID *Context
	);

	/**
	Iterate through a DHCP message to visit each option. First inspect
	all the options in the OPTION field. Then if overloaded, inspect
	the options in FILENAME and SERVERNAME fields. One option may be
	encoded in several places. See RFC 3396 Encoding Long Options in DHCP

	@param[in] Packet The DHCP packet to check the options for
	@param[in] Check The callback function to be called for each option
	found
	@param[in] Context The opaque parameter for Check

	@retval EFI_SUCCESS The DHCP packet's options are well formatted
	@retval EFI_INVALID_PARAMETER The DHCP packet's options are not well formatted

	**/
	EFI_STATUS
	DhcpIterateOptions (
	IN EFI_DHCP4_PACKET *Packet,
	IN DHCP_CHECK_OPTION Check OPTIONAL,
	IN VOID *Context
	);

	/**
	Validate the packet's options. If necessary, allocate
	and fill in the interested parameters.

	@param[in] Packet The packet to validate the options
	@param[out] Para The variable to save the DHCP parameters.

	@retval EFI_OUT_OF_RESOURCES Failed to allocate memory to validate the packet.
	@retval EFI_INVALID_PARAMETER The options are mal-formatted
	@retval EFI_SUCCESS The options are parsed into OptionPoint

	**/
	EFI_STATUS
	DhcpValidateOptions (
	IN EFI_DHCP4_PACKET *Packet,
	OUT DHCP_PARAMETER **Para OPTIONAL
	);

	/**
	Parse the options of a DHCP packet. It supports RFC 3396: Encoding
	Long Options in DHCP. That is, it will combine all the option value
	of all the occurrences of each option.
	A little bit of implementation:
	It adopts the "Key indexed counting" algorithm. First, it allocates
	an array of 256 DHCP_OPTION_COUNTs because DHCP option tag is encoded
	as a UINT8. It then iterates the DHCP packet to get data length of
	each option by calling DhcpIterOptions with DhcpGetOptionLen. Now, it
	knows the number of present options and their length. It allocates a
	array of DHCP_OPTION and a continuous buffer after the array to put
	all the options' data. Each option's data is pointed to by the Data
	field in DHCP_OPTION structure. At last, it call DhcpIterateOptions
	with DhcpFillOption to fill each option's data to its position in the
	buffer.

	@param[in] Packet The DHCP packet to parse the options
	@param[out] Count The number of valid dhcp options present in the
	packet
	@param[out] OptionPoint The array that contains the DHCP options. Caller
	should free it.

	@retval EFI_NOT_FOUND Cannot find any option.
	@retval EFI_OUT_OF_RESOURCES Failed to allocate memory to parse the packet.
	@retval EFI_INVALID_PARAMETER The options are mal-formatted
	@retval EFI_SUCCESS The options are parsed into OptionPoint

	**/
	EFI_STATUS
	DhcpParseOption (
	IN EFI_DHCP4_PACKET *Packet,
	OUT INTN *Count,
	OUT DHCP_OPTION **OptionPoint
	);

	/**
	Append an option to the memory, if the option is longer than
	255 bytes, splits it into several options.

	@param[out] Buf The buffer to append the option to
	@param[in] Tag The option's tag
	@param[in] DataLen The length of the option's data
	@param[in] Data The option's data

	@return The position to append the next option

	**/
	UINT8 *
	DhcpAppendOption (
	OUT UINT8 *Buf,
	IN UINT8 Tag,
	IN UINT16 DataLen,
	IN UINT8 *Data
	);

	/**
	Build a new DHCP packet from a seed packet. Options may be deleted or
	appended. The caller should free the NewPacket when finished using it.

	@param[in] SeedPacket The seed packet to start with
	@param[in] DeleteCount The number of options to delete
	@param[in] DeleteList The options to delete from the packet
	@param[in] AppendCount The number of options to append
	@param[in] AppendList The options to append to the packet
	@param[out] NewPacket The new packet, allocated and built by this
	function.

	@retval EFI_OUT_OF_RESOURCES Failed to allocate memory
	@retval EFI_INVALID_PARAMETER The options in SeekPacket are mal-formatted
	@retval EFI_SUCCESS The packet is build.

	**/
	EFI_STATUS
	DhcpBuild (
	IN EFI_DHCP4_PACKET *SeedPacket,
	IN UINT32 DeleteCount,
	IN UINT8 *DeleteList OPTIONAL,
	IN UINT32 AppendCount,
	IN EFI_DHCP4_PACKET_OPTION *AppendList[] OPTIONAL,
	OUT EFI_DHCP4_PACKET **NewPacket
	);

	#endif