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Inside Macintosh: Networking /

Chapter 7 - Datagram Delivery Protocol (DDP) / DDP Reference

Data Structures

The Write-Data Structure

A write-data structure is of type WDSElement and contains a series of pairs of length words and pointers. Each pair indicates the length and location of a portion of the data, including the header information, that constitutes the packet to be sent over the network.

You pass the PWriteDDP function a pointer to a write-data structure to send a DDP packet to another socket. You can use the BuildDDPwds procedure described on page 7-42 to create a write-data structure.

TYPE  WDSElement = 
RECORD
   entryLength:   Integer;
   entryPtr:      Ptr;
END;

Field Description

entryLength

The length of the data pointed to by entryPtr.

entryPtr

A pointer to the DDP packet data to be sent using the PWriteDDP function.