Inside Macintosh: Open Transport /

Chapter 5 - Option Management / Option Management Reference

Constants and Data Types

Status Codes

Open Transport uses status codes to return information about the success of an option negotiation. For individual options, Open Transport returns a status code in the status field of the TOption structure (page 5-32) describing the option. For groups of options negotiated by a single call to the OTOptionManagement function, the function also returns a status code that specifies the single worst result of the negotiation in the flags field of the ret parameter.

The constant names that are used to specify information about the outcome of option negotiation are given by the following enumeration:

enum
   {
      T_SUCCESS      = 0x020,
      T_FAILURE      = 0x040,
      T_PARTSUCCESS  = 0x100,
      T_READONLY     = 0x200,
      T_NOTSUPPORT   = 0x400
   };

Constant descriptions

T_SUCCESS

The requested value was negotiated.

T_FAILURE

The negotiation failed.

T_PARTSUCCESS

A lower requested value was negotiated.

T_READONLY

The option was read-only.

T_NOTSUPPORT

The endpoint does not support the requested value.

In addition to the status codes given by the status codes enumeration, an option can also have the value T_UNSPEC in the status field. This indicates that the option does not have a fully specified value at this time. An endpoint provider might return this status code if it cannot currently access the option value. This might happen if the endpoint is in the state T_UNBND in systems where the protocol stack resides on a separate host.