Telnet Server API

Setting up the Server

Callback Functions

Setting Server and Client Options

Other Telnet API Functions

Integrating a Telnet Server

Application Entry

TSInitServer(TS_ICONFIG_TYPE *ptr)

TSOpenPort(unsigned long *port,TS_UCONFIG_TYPE *ptr)

Structure that defines: • Telnet Port

• Login retries

• Client and server options TS_ECHO,TS_BINARY,TS_NOGA

• Callbacks for connect, login, disconnect, receive and buffer management

Structure that defines: • Number of ports to Listen on

Sample Telnet Port Setup

TS_UCONFIG_TYPE;Properties

&Callbacks

Setup Telnet Listener Using

Above Properties

Callback functions

int (*connect_callback) (unsigned int session_id)

int (*login_callback) (unsigned int session_id, int user_id)

int (*disconnect_callback) (unsigned int session_id)

int (*getbuf_callback) (unsigned int session_id, void **buf, int *bufSize)

int (*receive_callback) (unsigned int session_id, void *buf, int len)

Setting Server and Client Options

int TSSetServerOption( unsigned long session_id, unsigned long option, int mode)

int TSSetClientOption( unsigned long session_id, unsigned long option, int mode)

• mode – 0 off/1 on

• Option– TS_TXBINARY (xmit binary data)– TS_NOECHO (echo)– TS_NOGA (go-ahead characters)– TS_CAMOUFLAGE (server only – “camouflage” password)

(Note: “session_id” comes from connect or logon callback)

Other Telnet API Functions

int TSClosePort (unsigned long port_id)

int TSSendData (unsigned long session_id, char *buf, int len)

int TSSendString (unsigned long session_id, char *buf)

int TSCloseSession (unsigned long session_id)

char *TSGetSessionUserName (unsigned long session_id)

Telnet Server Summary

• Start with TSInitServer• Perform TSOpenPort for each port

– TS_UCONFIG_TYPE structure provides parameters (including callback addresses) on port-by-port basis

• Process client interaction via callbacks for connect, login, receive, disconnect and buffer acquisition

• Use TSSendData or TSSendString to transmit to client.

• Close session with TSCloseSession

• Close out port with TSClosePort