Inside Macintosh: Networking With Open Transport / Part 2 - Open Transport Reference

Chapter 22 - Endpoints Reference / Constants and Data Types

The TUnitData Structure

You use the TUnitData structure to describe the data being sent with the OTSndUData function and the data being read with the OTRcvUData function; you pass this structure as a parameter to each of these functions. When sending data you must initialize the buf and len fields of all the TNetbufs. When receiving data, you must initialize the buf and maxlen fields of all the TNetbufs.

The TUnitData structure is defined by the TUnitData type.

struct TUnitData
   {  TNetbuf  addr;
      TNetbuf  opt;
      TNetbuf  udata;
   };
typedef struct TUnitData TUnitData;

Field Description

addr

A TNetbuf structure for address information.

opt

A TNetbuf structure for option information.

udata

A TNetbuf structure for data.