Legacy Document

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

Chapter 22 - Endpoints Reference / Constants and Data Types

The TUDErr Structure

The TUDErr structure points to information that explains why the OTSndUData function has failed. You pass this structure as a parameter to the OTRcvUDErr function.

The TUDErr structure is defined by the TUDErr type.

struct TUDErr
   {  
      TNetbuf  addr;
      TNetbuf  opt;
      SInt32   error;
   };
typedef struct TUDErr TUDErr;

Field descriptions

addr

A TNetbuf structure that contains information about the destination address of the data sent using the OTSndUData function. The OTRcvUDErr function fills in the buffer referenced by this structure when the function returns. You must allocate a buffer to contain the address, initialize the addr.buf field to point to it, and set the addr.maxlen field to specify its maximum size. If you are not interested in address information, set addr.maxlen to 0.

opt

A TNetbuf structure that contains information about the options associated with the data sent using the OTSndUData function. The OTRcvUDErr function fills in the buffer referenced by this structure when the function returns. If you want to know this information, you must allocate a buffer to contain the option data, initialize the opt.buf field to point to it, and initialize the opt.maxlen field to specify the maximum size of the buffer. If you are not interested in option information, set the opt.maxlen field to 0.

error

On return, this specifies a protocol-dependent error code for the OTSndUData function that failed.