func GetFileCore(request *GetFileRequest) {
conn := request.Socket
file := request.File
commandParameters := request.FileName
if request.VerifyMode {
commandParameters = fmt.Sprintf("%s -v", commandParameters)
}
// Send the command
err := common.WriteMessage("get", commandParameters, conn)
if err != nil {
fmt.Println("Error writing command:", err)
return
}
// Read the status response
command, value, err := common.ReadMessage(conn.Reader)
if err != nil {
fmt.Println("Error reading status:", err)
return
}
if command == "error" {
fmt.Println("Server sent error:", value)
return
}
if command != "length" {
fmt.Printf("Unexpected message type '%s'\n", command)
return
}
segments := strings.Split(value, " ")
var hash string
if request.VerifyMode {
hash = segments[1]
}
length, err := strconv.Atoi(segments[0])
if err != nil {
fmt.Printf("Protocol error: %s. DEBUG: %s", err, segments[0])
return
}
fmt.Printf("Status OK, starting transfer of %d bytes\n", length)
hasher := md5.New()
totalRead := 0
buffer := make([]byte, 1024)
for totalRead < length {
read, err := conn.Read(buffer)
if err == io.EOF {
break
}
if err != nil {
fmt.Printf("Error reading from network: %s. Aborting transfer\n", err)
return
}
_, err = file.Write(buffer[:read])
if err != nil {
fmt.Println("Error writing to file; aborting transfer")
return
}
if request.Udp {
conn.Write([]byte("get-ack"))
}
hasher.Write(buffer[:read])
totalRead += read
}
if totalRead == length {
fmt.Println("Transfer complete")
realHash := hex.EncodeToString(hasher.Sum([]byte{}))
if request.VerifyMode && (len(realHash) == 0 || len(hash) == 0) {
fmt.Println("Checksum calculation failed")
} else if request.VerifyMode {
if realHash == hash {
fmt.Printf("Checksum OK")
} else {
fmt.Println("Checksum failed; file is corrupt")
fmt.Println("Expected: ", hash)
fmt.Println("Actual: ", realHash)
}
}
} else {
fmt.Println("Connection closed before transfer completed. File contents are likely incomplete.")
}
}
func ReadFileHandler(parameters string, connection io.ReadWriter) {
args := strings.Split(parameters, " ")
var verify bool
flagSet := flag.NewFlagSet("", flag.ContinueOnError)
flagSet.BoolVar(&verify, "v", false, "Verify")
flagSet.Parse(args[1:])
fileName := args[0]
log.Printf("Request for file '%s'", fileName)
file, err := os.Open(fileName)
if err != nil {
common.WriteError(connection, err)
return
}
stat, err := file.Stat()
if err != nil {
common.WriteError(connection, err)
file.Close()
return
}
hash, err := common.GetHash(file)
if err != nil {
log.Println("Hash calculation failed")
file.Close()
return
}
lengthParameters := fmt.Sprintf("%d", stat.Size())
if verify {
lengthParameters = fmt.Sprintf("%s %s", lengthParameters, hash)
}
common.WriteMessage("length", lengthParameters, connection)
buffer := make([]byte, 1024)
for {
// Read into buffer
len, err := file.Read(buffer)
// EOF?
if err == io.EOF {
log.Println("Transfer completed")
break
}
// Some other error
if err != nil {
log.Println("Error reading file; abandoning transfer")
break
}
// Write to socket
_, err = connection.Write(buffer[:len])
if err != nil {
log.Println("Failed to write data to socket; abandoning transfer")
}
}
file.Close()
}
func putFile(conn *bufio.ReadWriter, file *os.File, source string, conntype int) {
// Send the command
err := common.WriteMessage("put", source, conn)
if err != nil {
fmt.Println("Error writing command:", err)
return
}
// Read the status response
command, value, err := common.ReadMessage(conn.Reader)
if err != nil {
fmt.Println("Error reading status:", err)
return
}
if command == "ok" {
fmt.Printf("Status OK, starting transfer of %d bytes\n", source)
buffer := make([]byte, 1024)
if err != nil {
fmt.Println("Client file error:", file)
return
}
if conntype == 0 {
for {
n, err := file.Read(buffer)
if err == io.EOF {
fmt.Println("Transfer complete")
break
}
bytes := []byte(buffer)
_, err = conn.Write(bytes[0:n])
}
} else if conntype == 1 {
for {
file := context.file
buffer := make([]byte, 1024)
// Read into buffer
len, err := file.Read(buffer)
if len > 0 {
// Write to socket
bytes := []byte(buffer)
_, err = conn.Write(bytes[0:n])
if err != nil {
log.Println("Failed to write data to socket; abandoning transfer")
}
}
// EOF?
if err == io.EOF {
log.Println("Transfer completed")
break
}
// Some other error
if err != nil {
log.Println("Error reading file; abandoning transfer")
return
}
for {
if message != "put-ack" {
log.Println("Protocol error: expected get-ack")
continue
}
break
}
}
}
command, value, err := common.ReadMessage(conn.Reader)
if err != nil {
fmt.Println("Error reading status:", err)
return
}
if command == "error" {
fmt.Println("Server sent error:", value)
return
}
} else if command == "error" {
fmt.Println("Server sent error:", value)
return
} else {
fmt.Printf("Unexpected message type '%s'\n", command)
return
}
}