Data Structures
struct	DHCP_OPTION

struct	DHCP_OPTION_COUNT

struct	DHCP_OPTION_CONTEXT

struct	DHCP_PARAMETER

struct	DHCP_OPTION_FORMAT

Macros
#define	DHCP_OPTION_MAGIC 0x63538263

#define	DHCP_MAX_OPTIONS 256

#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

#define	DHCP_OVERLOAD_FILENAME 1

#define	DHCP_OVERLOAD_SVRNAME 2

#define	DHCP_OVERLOAD_BOTH 3

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

Functions
EFI_STATUS	DhcpIterateOptions (IN EFI_DHCP4_PACKET Packet, IN DHCP_CHECK_OPTION Check OPTIONAL, IN VOID Context)

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

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

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

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)

Detailed Description

To validate, parse and process the DHCP options.

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

Definition in file Dhcp4Option.h.

Macro Definition Documentation

◆ DHCP_MAX_OPTIONS

#define DHCP_MAX_OPTIONS 256

Definition at line 17 of file Dhcp4Option.h.

◆ DHCP_OPTION_INT16

#define DHCP_OPTION_INT16 3

Definition at line 24 of file Dhcp4Option.h.

◆ DHCP_OPTION_INT32

#define DHCP_OPTION_INT32 4

Definition at line 25 of file Dhcp4Option.h.

◆ DHCP_OPTION_INT8

#define DHCP_OPTION_INT8 2

Definition at line 23 of file Dhcp4Option.h.

◆ DHCP_OPTION_IP

#define DHCP_OPTION_IP 5

Definition at line 26 of file Dhcp4Option.h.

◆ DHCP_OPTION_IPPAIR

#define DHCP_OPTION_IPPAIR 6

Definition at line 27 of file Dhcp4Option.h.

◆ DHCP_OPTION_MAGIC

#define DHCP_OPTION_MAGIC 0x63538263

DHCP option tags (types)

Definition at line 16 of file Dhcp4Option.h.

◆ DHCP_OPTION_SWITCH

#define DHCP_OPTION_SWITCH 1

Definition at line 22 of file Dhcp4Option.h.

◆ DHCP_OVERLOAD_BOTH

#define DHCP_OVERLOAD_BOTH 3

Definition at line 34 of file Dhcp4Option.h.

◆ DHCP_OVERLOAD_FILENAME

#define DHCP_OVERLOAD_FILENAME 1

Definition at line 32 of file Dhcp4Option.h.

◆ DHCP_OVERLOAD_SVRNAME

#define DHCP_OVERLOAD_SVRNAME 2

Definition at line 33 of file Dhcp4Option.h.

Typedef Documentation

◆ DHCP_CHECK_OPTION

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

Definition at line 97 of file Dhcp4Option.h.

Function Documentation

◆ DhcpAppendOption()

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

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

Parameters

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

Returns: The position to append the next option

Definition at line 727 of file Dhcp4Option.c.

◆ DhcpBuild()

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
	)

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.

Parameters

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

Return values

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

Definition at line 770 of file Dhcp4Option.c.

◆ DhcpIterateOptions()

EFI_STATUS DhcpIterateOptions	(	IN EFI_DHCP4_PACKET *	Packet,
		IN DHCP_CHECK_OPTION Check	OPTIONAL,
		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

Parameters

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

Return values

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

Definition at line 382 of file Dhcp4Option.c.

◆ DhcpParseOption()

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

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.

Parameters

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

Return values

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

Definition at line 541 of file Dhcp4Option.c.

◆ DhcpValidateOptions()

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

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

Parameters

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

Return values

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

Definition at line 641 of file Dhcp4Option.c.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ DHCP_MAX_OPTIONS

◆ DHCP_OPTION_INT16

◆ DHCP_OPTION_INT32

◆ DHCP_OPTION_INT8

◆ DHCP_OPTION_IP

◆ DHCP_OPTION_IPPAIR

◆ DHCP_OPTION_MAGIC

◆ DHCP_OPTION_SWITCH

◆ DHCP_OVERLOAD_BOTH

◆ DHCP_OVERLOAD_FILENAME

◆ DHCP_OVERLOAD_SVRNAME

Typedef Documentation

◆ DHCP_CHECK_OPTION

Function Documentation

◆ DhcpAppendOption()

◆ DhcpBuild()

◆ DhcpIterateOptions()

◆ DhcpParseOption()

◆ DhcpValidateOptions()