DHCP
[TCP/IP Stack from Microchip Version 4.50 (Modified)]

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Detailed Description

Dynamic Host Configuration Protocol (DHCP) is a protocol used by networked devices (clients) to obtain various parameters necessary for the clients to operate in an Internet Protocol (IP) network.

By using this protocol, system administration workload greatly decreases, and devices can be added to the network with minimal or no manual configurations (Source: Wikipedia).

Files
file	DHCP.c
	Dynamic Host Configuration Protocol (DHCP) Client Module for Microchip TCP/IP Stack.
file	DHCP.h
	DHCP Defs for Microchip TCP/IP Stack.
Defines
#define	DHCPIsBound()   (DHCPFlags.bits.bIsBound)
	Determines if the DHCP server is currently bound.
Functions
void	DHCPReset (void)
	Resets the DHCP Client.
void	DHCPTask (void)
	Performs periodic DHCP tasks.
void	DHCPDisable (void)
	Disables the DHCP client.
void	DHCPEnable (void)
	Enables the DHCP client.
BOOL	DHCPHasBoundStateChanged (void)
	This function checks whether the internal address bound state of thze DHCP client has changed.
void	DHCPGetIPParameterFromServer (IPConfig_t *pIPConfig)
	If DHCP client is bound this function fills the given IP structure with the current IP parameters obtained from DHCP server.
BOOL	DHCPIsEnabled (void)
	This function returns the enable state of the DHCP client.
BOOL	DHCPHasFailed (void)
	This function returns the failed state of the DHCP client.

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Define Documentation

 

#define DHCPIsBound

(

)

(DHCPFlags.bits.bIsBound)

Determines if the DHCP server is currently bound.

Return values:

	TRUE	DHCP is bound to given configuration.
	FALSE	DHCP has not yet been bound.

Remarks:

This function is a MACRO to DHCPFlags.bits.bIsBound.

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Function Documentation

void DHCPDisable

(

void

)

Disables the DHCP client.

Disables the DHCP client by sending the state machine to "SM_DHCP_DISABLED". If the board was previously configured by DHCP, the configuration will continue to be used but the module will no longer preform any renewals.

Precondition:

None

Returns:

None

Remarks:

Since the board continues using its old configuration, it is possible that the lease may expire and the DHCP server provide the IP to another client. The application should replace the current IP address and other configuration with static information following a call to this function.

void DHCPEnable

(

void

)

Enables the DHCP client.

Enables the DHCP client if it is disabled. If it is already enabled, nothing is done.

Precondition:

None

Returns:

None

void DHCPGetIPParameterFromServer

(

IPConfig_t *

pIPConfig

)

If DHCP client is bound this function fills the given IP structure with the current IP parameters obtained from DHCP server.

Those parameters which are not obtained by server stay zero. If the client is not bound then the structure is cleared only.

Parameters:

pIPConfig

Pointer to IP structure field.

BOOL DHCPHasBoundStateChanged

(

void

)

This function checks whether the internal address bound state of thze DHCP client has changed.

The bound state change is a semaphore and clears automatically with this function call (if set).

Return values:

	TRUE	State has changed (either got an IP address or lost the current IP due elapsed lease time. Check DHCPIsBound for more details.
	FALSE	State has not changed since last call.

BOOL DHCPHasFailed

(

void

)

This function returns the failed state of the DHCP client.

Return values:

	TRUE	Obtaining has failed for the first time - client tries later automatically.
	FALSE	The client has successfully obtained IP data or obtianing is currently in progress.

BOOL DHCPIsEnabled

(

void

)

This function returns the enable state of the DHCP client.

Return values:

	TRUE	The client is enabled.
	FALSE	The client is disabled.

void DHCPReset

(

void

)

Resets the DHCP Client.

Resets the DHCP Client, giving up any current lease, knowledge of DHCP servers, etc.

Precondition:

None

Returns:

None

void DHCPTask

(

void

)

Performs periodic DHCP tasks.

This function performs any periodic tasks requied by the DHCP module, such as sending and receiving messages involved with obtaining and maintaining a lease.

Precondition:

None

Returns:

None

MODIFIX: Added AutoIP support.

Todo:

Save the probed auto IP-Address in EEPROM