Make requested TFTP transfer mode available to handlers. Resolves #2.

client.go

@@ -15,7 +15,7 @@ import (
 type Client struct {
 	log  *logger
 	net  string            // UDP network (ie, "udp", "udp4", "udp6")
-	mode transferMode      // TFTP transfer mode
+	mode TransferMode      // TFTP transfer mode
 	opts map[string]string // Map of TFTP options (RFC2347)
 
 	retransmit int // Per-packet retransmission limit
@@ -209,7 +209,7 @@ type ClientOpt func(*Client) error
 // ClientMode configures the mode.
 //
 // Valid options are ModeNetASCII and ModeOctet. Default is ModeNetASCII.
-func ClientMode(mode transferMode) ClientOpt {
+func ClientMode(mode TransferMode) ClientOpt {
 	return func(c *Client) error {
 		if mode != ModeNetASCII && mode != ModeOctet {
 			return ErrInvalidMode

client_test.go

@@ -37,7 +37,7 @@ func TestNewClient(t *testing.T) {
 
 		expectedError      error
 		expectedOpts       map[string]string
-		expectedMode       transferMode
+		expectedMode       TransferMode
 		expectedRetransmit int
 	}{
 		"default": {

conn.go

@@ -34,7 +34,7 @@ var defaultOptions = map[string]string{
 //
 // udpNet is one of "udp", "udp4", or "udp6"
 // addr is the address of the target client or server
-func newConn(udpNet string, mode transferMode, addr *net.UDPAddr) (*conn, error) {
+func newConn(udpNet string, mode TransferMode, addr *net.UDPAddr) (*conn, error) {
 	// Start listening, an empty UDPAddr will cause the system to assign a port
 	netConn, err := net.ListenUDP(udpNet, &net.UDPAddr{})
 	if err != nil {
@@ -56,7 +56,7 @@ func newConn(udpNet string, mode transferMode, addr *net.UDPAddr) (*conn, error)
 	return c, nil
 }
 
-func newSinglePortConn(addr *net.UDPAddr, mode transferMode, netConn *net.UDPConn, reqChan chan []byte) *conn {
+func newSinglePortConn(addr *net.UDPAddr, mode TransferMode, netConn *net.UDPConn, reqChan chan []byte) *conn {
 	return &conn{
 		log:        newLogger(addr.String()),
 		remoteAddr: addr,
@@ -74,7 +74,7 @@ func newSinglePortConn(addr *net.UDPAddr, mode transferMode, netConn *net.UDPCon
 // newConnFromHost wraps newConn and looks up the target's address from a string
 //
 // This function is used by Client
-func newConnFromHost(udpNet string, mode transferMode, host string) (*conn, error) {
+func newConnFromHost(udpNet string, mode TransferMode, host string) (*conn, error) {
 	// Resolve server
 	addr, err := net.ResolveUDPAddr(udpNet, host)
 	if err != nil {
@@ -102,7 +102,7 @@ type conn struct {
 	blksize    uint16        // Size of DATA payloads
 	timeout    time.Duration // How long to wait before resending packets
 	windowsize uint16        // Number of DATA packets between ACKs
-	mode       transferMode  // octet or netascii
+	mode       TransferMode  // octet or netascii
 	tsize      *int64        // Size of the file being sent/received
 
 	// Other, non-negotiable options

conn_test.go

@@ -23,11 +23,11 @@ func TestNewConn(t *testing.T) {
 
 	cases := map[string]struct {
 		net  string
-		mode transferMode
+		mode TransferMode
 		addr *net.UDPAddr
 
 		expectedAddr  *net.UDPAddr
-		expectedMode  transferMode
+		expectedMode  TransferMode
 		expectedError string
 	}{
 		"success": {
@@ -458,7 +458,7 @@ func TestConn_sendReadRequest(t *testing.T) {
 
 	cases := map[string]struct {
 		timeout  time.Duration
-		mode     transferMode
+		mode     TransferMode
 		connFunc func(string, *net.UDPConn, *net.UDPAddr)
 
 		expectedBuf        string

datagram.go

@@ -59,18 +59,19 @@ const (
 	ErrCodeNoSuchUser ErrorCode = 0x7
 
 	// ModeNetASCII is the string for netascii transfer mode
-	ModeNetASCII transferMode = "netascii"
+	ModeNetASCII TransferMode = "netascii"
 	// ModeOctet is the string for octet/binary transfer mode
-	ModeOctet transferMode = "octet"
-	modeMail  transferMode = "mail"
+	ModeOctet TransferMode = "octet"
+	modeMail  TransferMode = "mail"
 
 	optBlocksize    = "blksize"
 	optTimeout      = "timeout"
 	optTransferSize = "tsize"
 	optWindowSize   = "windowsize"
 )
 
-type transferMode string
+// TransferMode is a TFTP transer mode
+type TransferMode string
 
 var (
 	errorStrings = map[ErrorCode]string{
@@ -164,11 +165,11 @@ func (d *datagram) writeError(code ErrorCode, msg string) {
 	d.writeNull()
 }
 
-func (d *datagram) writeReadReq(filename string, mode transferMode, options map[string]string) {
+func (d *datagram) writeReadReq(filename string, mode TransferMode, options map[string]string) {
 	d.writeReq(opCodeRRQ, filename, mode, options)
 }
 
-func (d *datagram) writeWriteReq(filename string, mode transferMode, options map[string]string) {
+func (d *datagram) writeWriteReq(filename string, mode TransferMode, options map[string]string) {
 	d.writeReq(opCodeWRQ, filename, mode, options)
 }
 
@@ -187,7 +188,7 @@ func (d *datagram) writeOptionAck(options map[string]string) {
 }
 
 // Combines duplicate logic from RRQ and WRQ
-func (d *datagram) writeReq(o opcode, filename string, mode transferMode, options map[string]string) {
+func (d *datagram) writeReq(o opcode, filename string, mode TransferMode, options map[string]string) {
 	// This is ugly, could just set buf to 512
 	// or use a bytes buffer. Intend to switch to bytes buffer
 	// after implementing all RFCs so that perf can be compared
@@ -239,9 +240,9 @@ func (d *datagram) filename() string {
 }
 
 // Mode from RRQ and WRQ datagrams
-func (d *datagram) mode() transferMode {
+func (d *datagram) mode() TransferMode {
 	fields := bytes.Split(d.buf[2:], []byte{0x0})
-	return transferMode(fields[1])
+	return TransferMode(fields[1])
 }
 
 // Opcode from all datagrams

datagram_test.go

@@ -182,7 +182,7 @@ func TestDatagram(t *testing.T) {
 		code       opcode
 		block      uint16
 		filename   *string
-		mode       *transferMode
+		mode       *TransferMode
 		opts       options
 		errCode    *ErrorCode
 		errMessage *string
@@ -461,7 +461,7 @@ func ptrString(s string) *string {
 	return &s
 }
 
-func ptrMode(s transferMode) *transferMode {
+func ptrMode(s TransferMode) *TransferMode {
 	return &s
 }
 

handlers.go

@@ -48,6 +48,9 @@ type WriteRequest interface {
 	// connection. WriteError can only be called once. Read cannot
 	// be called after an error has been written.
 	WriteError(ErrorCode, string)
+
+	// TransferMode returns the TFTP transfer mode requested by the client.
+	TransferMode() TransferMode
 }
 
 // writeRequest implements WriteRequest.
@@ -80,6 +83,10 @@ func (w *writeRequest) WriteError(c ErrorCode, s string) {
 	w.conn.sendError(c, s)
 }
 
+func (w *writeRequest) TransferMode() TransferMode {
+	return w.conn.mode
+}
+
 // ReadRequest is provided to a ReadHandler's ServeTFTP method.
 type ReadRequest interface {
 	// Addr is the network address of the client.
@@ -99,6 +106,9 @@ type ReadRequest interface {
 	// WriteSize sets the transfer size (tsize) value to be sent to
 	// the client. It must be called before any calls to Write.
 	WriteSize(int64)
+
+	// TransferMode returns the TFTP transfer mode requested by the client.
+	TransferMode() TransferMode
 }
 
 // readRequest implements ReadRequest.
@@ -128,6 +138,10 @@ func (w *readRequest) WriteSize(i int64) {
 	w.conn.tsize = &i
 }
 
+func (w *readRequest) TransferMode() TransferMode {
+	return w.conn.mode
+}
+
 // FileServer creates a handler for sending and reciving files on the filesystem.
 func FileServer(dir string) ReadWriteHandler {
 	return &fileServer{path: dir, log: newLogger("fileserver")}

handlers_test.go

@@ -20,6 +20,7 @@ type readRequestMock struct {
 	errCode ErrorCode
 	errMsg  string
 	size    *int64
+	tmode   TransferMode
 }
 
 func (r *readRequestMock) Addr() *net.UDPAddr          { return r.addr }
@@ -30,6 +31,7 @@ func (r *readRequestMock) WriteError(c ErrorCode, m string) {
 	r.errCode = c
 	r.errMsg = m
 }
+func (r *readRequestMock) TransferMode() TransferMode { return r.tmode }
 
 func TestFileServer_ServeTFTP(t *testing.T) {
 	text := getTestData(t, "text")
@@ -96,6 +98,7 @@ type writeRequestMock struct {
 	errCode ErrorCode
 	errMsg  string
 	size    *int64
+	tmode   TransferMode
 }
 
 func (r *writeRequestMock) Addr() *net.UDPAddr         { return r.addr }
@@ -111,6 +114,7 @@ func (r *writeRequestMock) WriteError(c ErrorCode, m string) {
 	r.errCode = c
 	r.errMsg = m
 }
+func (r *writeRequestMock) TransferMode() TransferMode { return r.tmode }
 
 func TestFileServer_ReceiveTFTP(t *testing.T) {
 	text := getTestData(t, "text")