#include "Dhcp4Impl.h"

Functions
EFI_STATUS	DhcpInitRequest (IN DHCP_SERVICE *DhcpSb)

EFI_STATUS	DhcpCallUser (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_EVENT Event, IN EFI_DHCP4_PACKET Packet OPTIONAL, OUT EFI_DHCP4_PACKET **NewPacket OPTIONAL)

VOID	DhcpNotifyUser (IN DHCP_SERVICE *DhcpSb, IN INTN Which)

EFI_STATUS	DhcpSetState (IN OUT DHCP_SERVICE *DhcpSb, IN INTN State, IN BOOLEAN CallUser)

VOID	DhcpSetTransmitTimer (IN OUT DHCP_SERVICE *DhcpSb)

VOID	DhcpComputeLease (IN OUT DHCP_SERVICE DhcpSb, IN DHCP_PARAMETER Para)

EFI_STATUS EFIAPI	DhcpConfigLeaseIoPort (IN UDP_IO UdpIo, IN VOID Context)

EFI_STATUS	DhcpLeaseAcquired (IN OUT DHCP_SERVICE *DhcpSb)

VOID	DhcpCleanLease (IN DHCP_SERVICE *DhcpSb)

EFI_STATUS	DhcpChooseOffer (IN DHCP_SERVICE *DhcpSb)

VOID	DhcpEndSession (IN DHCP_SERVICE *DhcpSb, IN EFI_STATUS Status)

EFI_STATUS	DhcpHandleSelect (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_PACKET Packet, IN DHCP_PARAMETER *Para)

EFI_STATUS	DhcpHandleRequest (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_PACKET Packet, IN DHCP_PARAMETER *Para)

EFI_STATUS	DhcpHandleRenewRebind (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_PACKET Packet, IN DHCP_PARAMETER *Para)

EFI_STATUS	DhcpHandleReboot (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_PACKET Packet, IN DHCP_PARAMETER *Para)

VOID EFIAPI	DhcpInput (NET_BUF UdpPacket, UDP_END_POINT EndPoint, EFI_STATUS IoStatus, VOID *Context)

VOID EFIAPI	DhcpOnPacketSent (NET_BUF Packet, UDP_END_POINT EndPoint, EFI_STATUS IoStatus, VOID *Context)

EFI_STATUS	DhcpSendMessage (IN DHCP_SERVICE DhcpSb, IN EFI_DHCP4_PACKET Seed, IN DHCP_PARAMETER Para, IN UINT8 Type, IN UINT8 Msg)

EFI_STATUS	DhcpRetransmit (IN DHCP_SERVICE *DhcpSb)

VOID EFIAPI	DhcpOnTimerTick (IN EFI_EVENT Event, IN VOID *Context)

Variables
UINT32	mDhcp4DefaultTimeout [4] = { 4, 8, 16, 32 }

Detailed Description

EFI DHCP protocol implementation.

Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file Dhcp4Io.c.

Function Documentation

◆ DhcpCallUser()

EFI_STATUS DhcpCallUser	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_EVENT	Event,
		IN EFI_DHCP4_PACKET *Packet	OPTIONAL,
		OUT EFI_DHCP4_PACKET **NewPacket	OPTIONAL
	)

Call user provided callback function, and return the value the function returns. If the user doesn't provide a callback, a proper return value is selected to let the caller continue the normal process.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Event	The event as defined in the spec
[in]	Packet	The current packet trigger the event
[out]	NewPacket	The user's return new packet

Return values

EFI_NOT_READY	Direct the caller to continue collecting the offer.
EFI_SUCCESS	The user function returns success.
EFI_ABORTED	The user function ask it to abort.

Definition at line 75 of file Dhcp4Io.c.

◆ DhcpChooseOffer()

EFI_STATUS DhcpChooseOffer ( IN DHCP_SERVICE * DhcpSb )

Select a offer among all the offers collected. If the offer selected is of BOOTP, the lease is recorded and user notified. If the offer is of DHCP, it will request the offer from the server.

Parameters

[in] DhcpSb The DHCP service instance.

Return values

EFI_SUCCESS One of the offer is selected.

Definition at line 487 of file Dhcp4Io.c.

◆ DhcpCleanLease()

VOID DhcpCleanLease ( IN DHCP_SERVICE * DhcpSb )

Clean up the DHCP related states, IoStatus isn't reset.

Parameters

DhcpSb The DHCP instance service.

Definition at line 424 of file Dhcp4Io.c.

◆ DhcpComputeLease()

VOID DhcpComputeLease	(	IN OUT DHCP_SERVICE *	DhcpSb,
		IN DHCP_PARAMETER *	Para
	)

Compute the lease. If the server grants a permanent lease, just process it as a normal timeout value since the lease will last more than 100 years.

Parameters

DhcpSb	The DHCP service instance
Para	The DHCP parameter extracted from the server's response.

Definition at line 267 of file Dhcp4Io.c.

◆ DhcpConfigLeaseIoPort()

EFI_STATUS EFIAPI DhcpConfigLeaseIoPort	(	IN UDP_IO *	UdpIo,
		IN VOID *	Context
	)

Configure a UDP IO port to use the acquired lease address. DHCP driver needs this port to unicast packet to the server such as DHCP release.

Parameters

[in]	UdpIo	The UDP IO to configure
[in]	Context	Dhcp service instance.

Return values

EFI_SUCCESS	The UDP IO port is successfully configured.
Others	It failed to configure the port.

Definition at line 305 of file Dhcp4Io.c.

◆ DhcpEndSession()

VOID DhcpEndSession	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_STATUS	Status
	)

Terminate the current address acquire. All the allocated resources are released. Be careful when calling this function. A rule related to this is: only call DhcpEndSession at the highest level, such as DhcpInput, DhcpOnTimerTick...At the other level, just return error.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Status	The result of the DHCP process.

Definition at line 565 of file Dhcp4Io.c.

◆ DhcpHandleReboot()

EFI_STATUS DhcpHandleReboot	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_PACKET *	Packet,
		IN DHCP_PARAMETER *	Para
	)

Handle packets in DHCP reboot state.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Packet	The DHCP packet received
[in]	Para	The DHCP parameter extracted from the packet. That is, all the option value that we care.

Return values

EFI_SUCCESS	The packet is successfully processed.
Others	Some error occurred.

Definition at line 843 of file Dhcp4Io.c.

◆ DhcpHandleRenewRebind()

EFI_STATUS DhcpHandleRenewRebind	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_PACKET *	Packet,
		IN DHCP_PARAMETER *	Para
	)

Handle packets in DHCP renew/rebound state.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Packet	The DHCP packet received
[in]	Para	The DHCP parameter extracted from the packet. That is, all the option value that we care.

Return values

EFI_SUCCESS	The packet is successfully processed.
Others	Some error occurred.

Definition at line 760 of file Dhcp4Io.c.

◆ DhcpHandleRequest()

EFI_STATUS DhcpHandleRequest	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_PACKET *	Packet,
		IN DHCP_PARAMETER *	Para
	)

Handle packets in DHCP request state.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Packet	The DHCP packet received
[in]	Para	The DHCP parameter extracted from the packet. That is, all the option value that we care.

Return values

EFI_SUCCESS	The packet is successfully processed.
Others	Some error occurred.

Definition at line 668 of file Dhcp4Io.c.

◆ DhcpHandleSelect()

EFI_STATUS DhcpHandleSelect	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_PACKET *	Packet,
		IN DHCP_PARAMETER *	Para
	)

Handle packets in DHCP select state.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Packet	The DHCP packet received
[in]	Para	The DHCP parameter extracted from the packet. That is, all the option value that we care.

Return values

EFI_SUCCESS	The packet is successfully processed.
Others	Some error occurred.

Definition at line 595 of file Dhcp4Io.c.

◆ DhcpInitRequest()

EFI_STATUS DhcpInitRequest ( IN DHCP_SERVICE * DhcpSb )

Send an initial DISCOVER or REQUEST message according to the DHCP service's current state.

Parameters

[in] DhcpSb The DHCP service instance

Return values

EFI_SUCCESS	The request has been sent
other	Some error occurs when sending the request.

Definition at line 24 of file Dhcp4Io.c.

◆ DhcpInput()

VOID EFIAPI DhcpInput	(	NET_BUF *	UdpPacket,
		UDP_END_POINT *	EndPoint,
		EFI_STATUS	IoStatus,
		VOID *	Context
	)

Handle the received DHCP packets. This function drives the DHCP state machine.

Parameters

UdpPacket	The UDP packets received.
EndPoint	The local/remote UDP access point
IoStatus	The status of the UDP receive
Context	The opaque parameter to the function.

Definition at line 927 of file Dhcp4Io.c.

◆ DhcpLeaseAcquired()

EFI_STATUS DhcpLeaseAcquired ( IN OUT DHCP_SERVICE * DhcpSb )

Update the lease states when a new lease is acquired. It will not only save the acquired the address and lease time, it will also create a UDP child to provide address resolution for the address.

Parameters

DhcpSb The DHCP service instance

Return values

EFI_OUT_OF_RESOURCES	Failed to allocate resources.
EFI_SUCCESS	The lease is recorded.

Definition at line 374 of file Dhcp4Io.c.

◆ DhcpNotifyUser()

VOID DhcpNotifyUser	(	IN DHCP_SERVICE *	DhcpSb,
		IN INTN	Which
	)

Notify the user about the operation result.

Parameters

DhcpSb	DHCP service instance
Which	Which notify function to signal

Definition at line 135 of file Dhcp4Io.c.

◆ DhcpOnPacketSent()

VOID EFIAPI DhcpOnPacketSent	(	NET_BUF *	Packet,
		UDP_END_POINT *	EndPoint,
		EFI_STATUS	IoStatus,
		VOID *	Context
	)

Release the net buffer when packet is sent.

Parameters

UdpPacket	The UDP packets received.
EndPoint	The local/remote UDP access point
IoStatus	The status of the UDP receive
Context	The opaque parameter to the function.

Definition at line 1084 of file Dhcp4Io.c.

◆ DhcpOnTimerTick()

VOID EFIAPI DhcpOnTimerTick	(	IN EFI_EVENT	Event,
		IN VOID *	Context
	)

Each DHCP service has three timer. Two of them are count down timer. One for the packet retransmission. The other is to collect the offers. The third timer increments the lease life which is compared to T1, T2, and lease to determine the time to renew and rebind the lease. DhcpOnTimerTick will be called once every second.

Parameters

[in]	Event	The timer event
[in]	Context	The context, which is the DHCP service instance.

Definition at line 1459 of file Dhcp4Io.c.

◆ DhcpRetransmit()

EFI_STATUS DhcpRetransmit ( IN DHCP_SERVICE * DhcpSb )

Retransmit a saved packet. Only DISCOVER and REQUEST messages will be retransmitted.

Parameters

[in] DhcpSb The DHCP service instance

Return values

EFI_ACCESS_DENIED	Failed to transmit packet through UDP port
EFI_SUCCESS	The packet is retransmitted.

Definition at line 1382 of file Dhcp4Io.c.

◆ DhcpSendMessage()

EFI_STATUS DhcpSendMessage	(	IN DHCP_SERVICE *	DhcpSb,
		IN EFI_DHCP4_PACKET *	Seed,
		IN DHCP_PARAMETER *	Para,
		IN UINT8	Type,
		IN UINT8 *	Msg
	)

Build and transmit a DHCP message according to the current states. This function implement the Table 5. of RFC 2131. Always transits the state (as defined in Figure 5. of the same RFC) before sending a DHCP message. The table is adjusted accordingly.

Parameters

[in]	DhcpSb	The DHCP service instance
[in]	Seed	The seed packet which the new packet is based on
[in]	Para	The DHCP parameter of the Seed packet
[in]	Type	The message type to send
[in]	Msg	The human readable message to include in the packet sent.

Return values

EFI_OUT_OF_RESOURCES	Failed to allocate resources for the packet
EFI_ACCESS_DENIED	Failed to transmit the packet through UDP
EFI_SUCCESS	The message is sent
other	Other error occurs

Definition at line 1114 of file Dhcp4Io.c.

◆ DhcpSetState()

EFI_STATUS DhcpSetState	(	IN OUT DHCP_SERVICE *	DhcpSb,
		IN INTN	State,
		IN BOOLEAN	CallUser
	)

Set the DHCP state. If CallUser is true, it will try to notify the user before change the state by DhcpNotifyUser. It returns EFI_ABORTED if the user return EFI_ABORTED, otherwise, it returns EFI_SUCCESS. If CallUser is FALSE, it isn't necessary to test the return value of this function.

Parameters

DhcpSb	The DHCP service instance
State	The new DHCP state to change to
CallUser	Whether we need to call user

Return values

EFI_SUCCESS	The state is changed
EFI_ABORTED	The user asks to abort the DHCP process.

Definition at line 179 of file Dhcp4Io.c.

◆ DhcpSetTransmitTimer()

VOID DhcpSetTransmitTimer ( IN OUT DHCP_SERVICE * DhcpSb )

Set the retransmit timer for the packet. It will select from either the discover timeouts/request timeouts or the default timeout values.

Parameters

DhcpSb The DHCP service instance.

Definition at line 233 of file Dhcp4Io.c.

Variable Documentation

◆ mDhcp4DefaultTimeout

UINT32 mDhcp4DefaultTimeout[4] = { 4, 8, 16, 32 }

Definition at line 11 of file Dhcp4Io.c.

Functions

Variables

Detailed Description

Function Documentation

◆ DhcpCallUser()

◆ DhcpChooseOffer()

◆ DhcpCleanLease()

◆ DhcpComputeLease()

◆ DhcpConfigLeaseIoPort()

◆ DhcpEndSession()

◆ DhcpHandleReboot()

◆ DhcpHandleRenewRebind()

◆ DhcpHandleRequest()

◆ DhcpHandleSelect()

◆ DhcpInitRequest()

◆ DhcpInput()

◆ DhcpLeaseAcquired()

◆ DhcpNotifyUser()

◆ DhcpOnPacketSent()

◆ DhcpOnTimerTick()

◆ DhcpRetransmit()

◆ DhcpSendMessage()

◆ DhcpSetState()

◆ DhcpSetTransmitTimer()

Variable Documentation

◆ mDhcp4DefaultTimeout