Unit IGMP

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Description

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Ultibo IGMP (Internet Group Management Protocol) unit

To be documented

Constants

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IGMP specific constants IGMP_PROTOCOL_*

Note: Some IGMP definitions are in the Protocol or IP modules
IGMP_PROTOCOL_NAME = 'IGMP';

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IGMP constants IGMP_*

IGMP_TIMEOUT = 0;	Wait forever on a IGMP Read
IGMP_BUFFER_SIZE = 65536;	IGMP Receive Buffer Size
IGMP_HEADER_SIZE = 8;	SizeOf(TIGMPHeader);
IGMP_PACKET_SIZE = 8;	SizeOf(TIGMPPacket)
IGMP_QUERY_TIMEOUT = 5000;
IGMP_REPORT_TIMEOUT = 5000;
IGMP_TRANSMIT_COUNT = 3;

Type definitions

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IGMP header

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PIGMPHeader = ^TIGMPHeader;

TIGMPHeader = packed record

Note: Some IGMP definitions are in the Protocol or IP modules

IGMPType:Byte;	type of IGMP message
RespTime:Byte;	Query only otherwise 0 (Always zero in Version 1 (Assume 100))
Checksum:Word;	1s Compliment IP-style checksum
Address:TInAddr;	group address being reported or queried (zero for "General" queries)

IGMP packet

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PIGMPPacket = ^TIGMPPacket;

TIGMPPacket = record

Note: 8 Bytes (Used by IGMPBuffer)
Size:LongWord;	LongWord to keep size even
Next:PIGMPPacket;	Followed by RemoteAddress (4 or 16 Bytes)

Class definitions

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To be documented

Public variables

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None defined

Function declarations

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Initialization functions

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procedure IGMPInit;

Description: To be documented

Note	None documented

IGMP functions

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function CheckIGMP(AFamily:Word; ABuffer:Pointer):Boolean;

Description: Verify that the packet is a valid IGMP packet

Buffer	The complete packet including Transport header

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function GetIGMPHeaderOffset(AFamily:Word; ABuffer:Pointer):Word;

Description: To be documented

Buffer	The complete packet including Transport header

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function GetIGMPHeaderLength(AFamily:Word; ABuffer:Pointer):Word;

Description: To be documented

Buffer	The complete packet including Transport header

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function GetIGMPDataOffset(AFamily:Word; ABuffer:Pointer):Word;

Description: To be documented

Buffer	The complete packet including Transport header

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function GetIGMPDataLength(AFamily:Word; ABuffer:Pointer):Word;

Description: To be documented

Buffer	The complete packet including Transport header

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function ChecksumIGMP(AFamily:Word; ABuffer:Pointer; AOffset,ALength:Word):Word;

Description: Checksum the IGMP Header on Send / Validate the Checksum on Receive

Note	Checksum is calculated on the whole packet (Header and Data)

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