// checks request code and calls corresponding function
func (st StorageNode) handleCode(uuid uint64, code uint8, conn net.Conn, r *bufio.Reader, w *bufio.Writer) {
switch code {
case 1: // client is requesting a file
hash := utils.ReadHashAsString(r)
fmt.Println("Hash received: " + hash)
// check if file exists
var sendcode uint8
fp := st.getPath() + "files/" + hash
if _, err := os.Stat(fp); err == nil {
fmt.Println("File with hash " + hash + " exists")
sendcode = 3 // file available code
err := w.WriteByte(sendcode) // let client know
if err != nil {
panic(err)
}
w.Flush()
// send the file
fmt.Println("Sending file " + hash)
utils.SendFile(conn, w, fp)
} else {
fmt.Println("File with hash " + hash + " does not exist")
sendcode = 4
err := w.WriteByte(sendcode) // let client know
if err != nil {
panic(err)
}
w.Flush()
}
case 2: // receive file from client
fmt.Println("Receiving file")
hash := utils.ReadHashAsString(r)
output := st.getPath() + "files/" + hash
utils.ReceiveFile(conn, r, output)
fmt.Println("File received; md5 checksum of file is: " + hash)
}
fmt.Println()
conn.Close()
}
func request(r *bufio.Reader, w *bufio.Writer, currentDir string, args []string, thisUser *utils.User) (err error) {
// should have args format:
// request [remote filename] [local filename]
// currently:
// request [remote filename]
// Local filename can be a relative or absolute path
if len(args) < 2 {
return err
}
// START SENDCODE BLOCK
err = w.WriteByte(5)
w.Flush()
if err != nil {
panic(err)
}
// END SENDCODE BLOCK
// Send current dir
w.WriteString(currentDir + "\n")
w.Flush()
// Format the file to send
w.WriteString(args[1] + "\n")
w.Flush()
fmt.Println("Requesting: " + path.Join(currentDir, args[1]))
success, _ := r.ReadByte()
if success == 3 {
fmt.Println("You do not have permission to request this file")
return nil
} else if success != 4 {
fmt.Println("Invalid file request")
return nil
}
protected := false
enc, _ := r.ReadByte()
if enc == 1 {
protected = true
}
success, _ = r.ReadByte()
if success != 2 {
fmt.Println("No stnodes for your file")
return nil
}
hash, _ := r.ReadString('\n')
protocol, _ := r.ReadString('\n')
nAddress, _ := r.ReadString('\n')
hash = strings.TrimSpace(hash)
protocol = strings.TrimSpace(protocol)
nAddress = strings.TrimSpace(nAddress)
conn, err := net.Dial(protocol, nAddress)
if err != nil {
fmt.Println("Error connecting to stnode")
}
ws := bufio.NewWriter(conn)
rs := bufio.NewReader(conn)
ws.WriteByte(1)
bytehash, err := hex.DecodeString(hash)
if err != nil {
return err
}
err = utils.WriteHash(ws, bytehash)
if err != nil {
return err
}
success, _ = rs.ReadByte()
if success != 3 {
fmt.Println("File cannot be found on stnode")
return err
}
output := utils.GetUserHome() + "/.mdfs/client/" + thisUser.Uname + "/files/" + path.Base(args[1])
if protected {
encrypFile := os.TempDir() + "/" + path.Base(args[1])
utils.ReceiveFile(conn, rs, encrypFile)
err = utils.DecryptFile(encrypFile, output, *thisUser)
if err != nil {
fmt.Println("Your key does not match the lock for this file")
return nil
}
fmt.Println("Protected file successfully unlocked")
} else {
utils.ReceiveFile(conn, rs, output)
}
fmt.Println("Successfully received file")
fmt.Println("File stored at: " + output)
return
}