net/dhcp.h File Reference

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Detailed Description

DHCP client Module for Modtronix TCP/IP Stack.

Author:

Modtronix Engineering

Dependencies:

stacktsk.h, udp.h

Compiler:

MPLAB C18 v2.10 or higher
HITECH PICC-18 V8.35PL3 or higher

Description

This module implements a DHCP client.
For a detailed description, see the DHCP section of this document - in [Modules] [TCP/IP Stack] [TCP/IP User Protocols].

Configuration

The following defines are used to configure this module, and should be placed in the projdefs.h (or similar) file. For details, see Project Configuration. To configure the module, the required defines should be uncommended, and the rest commented out.

 //*********************************************************************
 //-------------------- DHCP Configuration --------------------
 //*********************************************************************
 //Defines DHCP ports
 #define DHCP_CLIENT_PORT    (68)
 #define DHCP_SERVER_PORT    (67)

 //The stack uses the macro STACK_IS_DHCP_ENABLED to determine if DHCP is enabled or not.
 //The user can for example assign this macro to check if a flag is set. If not defined
 //by the user, it will be set to true.
 //#define STACK_IS_DHCP_ENABLED   (netflags & 0x01)

 //Timeouts
 #define DHCP_TIMEOUT        (TICK)(5 * TICK_SECOND)

Data Structures
union	_DHCP_STATE
Defines
#define	DHCP_CLIENT_PORT   (68)
#define	DHCP_SERVER_PORT   (67)
#define	DHCP_TIMEOUT   ((TICK16)(2 * TICKS_PER_SECOND))
#define	DHCPDisable()   (smDHCPState = SM_DHCP_DISABLED)
#define	DHCPIsBound()   (DHCPState.bits.bIsBound)
#define	STACK_IS_DHCP_ENABLED   (1)
Typedefs
typedef _DHCP_STATE	DHCP_STATE
typedef enum _SM_DHCP	SM_DHCP
Enumerations
enum	_SM_DHCP {   SM_DHCP_INIT_FIRST_TIME, SM_DHCP_INIT, SM_DHCP_RESET_WAIT, SM_DHCP_BROADCAST,   SM_DHCP_DISCOVER, SM_DHCP_REQUEST, SM_DHCP_BIND, SM_DHCP_BOUND,   SM_DHCP_DISABLED }
Functions
void	DHCPReset (void)
void	DHCPTask (void)
Variables
DHCP_STATE	DHCPState
SM_DHCP	smDHCPState

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Define Documentation

#define DHCP_CLIENT_PORT   (68)

#define DHCP_SERVER_PORT   (67)

#define DHCP_TIMEOUT   ((TICK16)(2 * TICKS_PER_SECOND))

 

#define DHCPDisable

(

)

(smDHCPState = SM_DHCP_DISABLED)

Puts DHCPTask into unhandled state "SM_DHCP_DISABLED" and hence DHCP is effictively disabled. Note: This macro should be called before DHCPTask is called or else a UDP port will be kept open and there will be no task to process it.

 

#define DHCPIsBound

(

)

(DHCPState.bits.bIsBound)

Checks is DHCP is bound

Returns:

TRUE if DHCP is bound to given configuration FALSE if DHCP has yet to be bound.

#define STACK_IS_DHCP_ENABLED   (1)

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Typedef Documentation

typedef union _DHCP_STATE DHCP_STATE

typedef enum _SM_DHCP SM_DHCP

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Enumeration Type Documentation

enum _SM_DHCP

Enumerator:

SM_DHCP_INIT_FIRST_TIME
SM_DHCP_INIT
SM_DHCP_RESET_WAIT
SM_DHCP_BROADCAST
SM_DHCP_DISCOVER
SM_DHCP_REQUEST
SM_DHCP_BIND
SM_DHCP_BOUND
SM_DHCP_DISABLED

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Function Documentation

void DHCPReset

(

void

)

Closes any previously opened DHCP socket and resets DHCP state machine so that on next call to DHCPTask will result in new DHCP request.

void DHCPTask

(

void

)

Fetches pending UDP packet from MAC receive buffer and dispatches it appropriate UDP socket. If not UDP socket is matched, UDP packet is silently discarded. Note: Caller must make sure that MAC receive buffer access pointer is set to begining of UDP packet. Required steps before calling this function is:

If ( MACIsRxReady() ) { MACGetHeader() If MACFrameType == IP IPGetHeader() if ( IPFrameType == IP_PROT_UDP ) Call DHCPTask() ... }

Pre-Condition:

: DHCPInit() is already called AND IPGetHeader() is called with IPFrameType == IP_PROT_UDP

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Variable Documentation

DHCP_STATE DHCPState

SM_DHCP smDHCPState

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