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Allow arbitrary connection protocols #26

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Allow arbitrary connection protocols #26

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32 changes: 12 additions & 20 deletions conn.go
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Original file line number Diff line number Diff line change
@@ -1,12 +1,10 @@
package telnet


import (
"crypto/tls"
"net"
)


type Conn struct {
conn interface {
Read(b []byte) (n int, err error)
Expand All @@ -19,7 +17,6 @@ type Conn struct {
dataWriter *internalDataWriter
}


// Dial makes a (un-secure) TELNET client connection to the system's 'loopback address'
// (also known as "localhost" or 127.0.0.1).
//
Expand All @@ -33,9 +30,10 @@ func Dial() (*Conn, error) {
//
// If a secure connection is desired, use `DialToTLS` instead.
func DialTo(addr string) (*Conn, error) {
return DialToNetwork("tcp", addr)
}

const network = "tcp"

func DialToNetwork(network string, addr string) (*Conn, error) {
if "" == addr {
addr = "127.0.0.1:telnet"
}
Expand All @@ -49,15 +47,14 @@ func DialTo(addr string) (*Conn, error) {
dataWriter := newDataWriter(conn)

clientConn := Conn{
conn:conn,
dataReader:dataReader,
dataWriter:dataWriter,
conn: conn,
dataReader: dataReader,
dataWriter: dataWriter,
}

return &clientConn, nil
}


// DialTLS makes a (secure) TELNETS client connection to the system's 'loopback address'
// (also known as "localhost" or 127.0.0.1).
func DialTLS(tlsConfig *tls.Config) (*Conn, error) {
Expand All @@ -67,9 +64,10 @@ func DialTLS(tlsConfig *tls.Config) (*Conn, error) {
// DialToTLS makes a (secure) TELNETS client connection to the the address specified by
// 'addr'.
func DialToTLS(addr string, tlsConfig *tls.Config) (*Conn, error) {
return DialToNetworkTLS("tcp", addr, tlsConfig)
}

const network = "tcp"

func DialToNetworkTLS(network string, addr string, tlsConfig *tls.Config) (*Conn, error) {
if "" == addr {
addr = "127.0.0.1:telnets"
}
Expand All @@ -83,16 +81,14 @@ func DialToTLS(addr string, tlsConfig *tls.Config) (*Conn, error) {
dataWriter := newDataWriter(conn)

clientConn := Conn{
conn:conn,
dataReader:dataReader,
dataWriter:dataWriter,
conn: conn,
dataReader: dataReader,
dataWriter: dataWriter,
}

return &clientConn, nil
}



// Close closes the client connection.
//
// Typical usage might look like:
Expand All @@ -107,7 +103,6 @@ func (clientConn *Conn) Close() error {
return clientConn.conn.Close()
}


// Read receives `n` bytes sent from the server to the client,
// and "returns" into `p`.
//
Expand All @@ -122,7 +117,6 @@ func (clientConn *Conn) Read(p []byte) (n int, err error) {
return clientConn.dataReader.Read(p)
}


// Write sends `n` bytes from 'p' to the server.
//
// Note that Write can only be used for sending TELNET (and TELNETS) data to the server.
Expand All @@ -135,13 +129,11 @@ func (clientConn *Conn) Write(p []byte) (n int, err error) {
return clientConn.dataWriter.Write(p)
}


// LocalAddr returns the local network address.
func (clientConn *Conn) LocalAddr() net.Addr {
return clientConn.conn.LocalAddr()
}


// RemoteAddr returns the remote network address.
func (clientConn *Conn) RemoteAddr() net.Addr {
return clientConn.conn.RemoteAddr()
Expand Down
11 changes: 2 additions & 9 deletions data_writer.go
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Original file line number Diff line number Diff line change
@@ -1,6 +1,5 @@
package telnet


import (
"github.com/reiver/go-oi"

Expand All @@ -9,13 +8,11 @@ import (
"io"
)


var iaciac []byte = []byte{255, 255}

var errOverflow = errors.New("Overflow")
var errPartialIACIACWrite = errors.New("Partial IAC IAC write.")


// An internalDataWriter deals with "escaping" according to the TELNET (and TELNETS) protocol.
//
// In the TELNET (and TELNETS) protocol byte value 255 is special.
Expand All @@ -24,7 +21,7 @@ var errPartialIACIACWrite = errors.New("Partial IAC IAC write.")
//
// The TELNET (and TELNETS) protocol also has a distinction between 'data' and 'commands'.
//
//(DataWriter is targetted toward TELNET (and TELNETS) 'data', not TELNET (and TELNETS) 'commands'.)
// (DataWriter is targeted toward TELNET (and TELNETS) 'data', not TELNET (and TELNETS) 'commands'.)
//
// If a byte with value 255 (=IAC) appears in the data, then it must be escaped.
//
Expand All @@ -49,7 +46,6 @@ type internalDataWriter struct {
wrapped io.Writer
}


// newDataWriter creates a new internalDataWriter writing to 'w'.
//
// 'w' receives what is written to the *internalDataWriter but escaped according to
Expand All @@ -70,13 +66,12 @@ type internalDataWriter struct {
// *internalDataWriter takes care of all this for you, so you do not have to do it.
func newDataWriter(w io.Writer) *internalDataWriter {
writer := internalDataWriter{
wrapped:w,
wrapped: w,
}

return &writer
}


// Write writes the TELNET (and TELNETS) escaped data for of the data in 'data' to the wrapped io.Writer.
func (w *internalDataWriter) Write(data []byte) (n int, err error) {
var n64 int64
Expand All @@ -90,7 +85,6 @@ func (w *internalDataWriter) Write(data []byte) (n int, err error) {
return n, err
}


func (w *internalDataWriter) write64(data []byte) (n int64, err error) {

if len(data) <= 0 {
Expand All @@ -115,7 +109,6 @@ func (w *internalDataWriter) write64(data []byte) (n int64, err error) {
buffer.Reset()
}


var numWritten int64
//@TODO: Should we worry about "iaciac" potentially being modified by the .Write()?
numWritten, err = oi.LongWrite(w.wrapped, iaciac)
Expand Down