ct_getloginfo

Description

Transfer TDS login response information from a CS_CONNECTION structure to a newly allocated CS_LOGINFO structure.

Syntax

CS_RETCODE ct_getloginfo (connection, logptr)
 
 CS_CONNECTION    *connection;
 CS_LOGINFO             **logptr;

Parameters

connection: A pointer to a CS_CONNECTION structure. A CS_CONNECTION structure contains information about a particular client/server connection.

logptr: A pointer to a program variable which ct_getloginfo sets to the address of a newly allocated CS_LOGINFO structure.

Returns

ct_getloginfo returns the following values:

Return value	Meaning
CS_SUCCEED	The routine completed successfully.
CS_FAIL	The routine failed.
CS_BUSY	An asynchronous operation is already pending for this connection. See “Asynchronous programming”.

Usage

TDS (Tabular Data Stream) is a communications protocol used for the transfer of requests and request results between clients and servers.
There are two reasons an application might call ct_getloginfo:
- If it is an Open Server gateway application using TDS passthrough.
- To copy login properties from an open connection to a newly allocated connection structure.
  
  Do not call ct_getloginfo from within a completion callback routine. ct_getloginfo calls system-level memory functions that may not be reentrant.

TDS passthrough

When a client connects directly to a server, the two programs negotiate the TDS format they will use to send and receive data. When a gateway application uses TDS passthrough, the gateway forwards TDS packets between the client and a remote server without examining or processing them. For this reason, the remote server and the client must agree on a TDS format to use.
ct_getloginfo is the third of four calls, two of them Server Library calls, that allow a client and a remote server to negotiate a TDS format. The calls, which can be made only in an Open Server SRV_CONNECT event handler, are:
1. srv_getloginfo to allocate a CS_LOGINFO structure and fill it with TDS information from a client login request.
2. ct_setloginfo to transfer the TDS information retrieved in step 1 from the CS_LOGINFO structure to a Client-Library CS_CONNECTION structure. The gateway uses this CS_CONNECTION structure in the ct_connect call which establishes its connection with the remote server.
3. ct_getloginfo to transfer the remote server’s response to the client’s TDS information from the CS_CONNECTION structure into a newly allocated CS_LOGINFO structure.
4. srv_setloginfo to send the remote server’s response, retrieved in step 3, to the client.

Copying login properties

For information about using ct_getloginfo to copy login properties from an open connection to a newly allocated connection structure, see “Properties”.