conn (net.Conn) does not write always on socket

I have done an application with a server and client to send information with a socket TCP

The problem is, if the function zfs.ReceiveSnapshot (in server side) does not return an error (err == nil), conn.Write([]byte("0")) does not work and the client does not receive any byte to continue and it cannot close the connection...

I show you the code of server and client

Server:

package main

import (
	"net"
	"github.com/mistifyio/go-zfs"
)

func main() {
	// Listen for incoming connections
	l, _ := net.Listen("tcp", ":7766")
	
	// Close the listener when the application closes
	defer l.Close()
	fmt.Println("Listening on port 7766...")
	for {
		// Listen for an incoming connection.
		conn, _ := l.Accept()
		// Handle connections in a new goroutine.
	    go handleRequest(conn)
	}
}

// Handles incoming requests
func handleRequest(conn net.Conn) {
	// Receive snapshot
	_, err := zfs.ReceiveSnapshot(conn, "tank/replication")
	if err != nil {
		conn.Write([]byte("1"))
		zfs.ReceiveSnapshot(conn, "tank/replication")
		conn.Close()
	} else {
		conn.Write([]byte("0"))
		conn.Close()
	}
}

Client:

package main

import (
	"net"
	"github.com/mistifyio/go-zfs"
)

func main() {
	conn, _ := net.Dial("tcp", "192.168.99.5:7766")

	for i := 0; i < 1; i++ {
		// Get all snapshots in tank/test
		take, _ := zfs.Snapshots("tank/test")

		// Select snapshots
		snap := take[0].Name
		ds1, _ := zfs.GetDataset(snap)

		// Send first snapshot
		ds1.SendSnapshot(conn)
		defer conn.Close()

		buff := make([]byte, 1024)
		n, _ := conn.Read(buff)

		if n != 0 {
			snap = take[1].Name
			ds2, _ := zfs.GetDataset(snap)
			zfs.SendSnapshotIncremental(conn, ds1, ds2, zfs.IncrementalStream)
			conn.Close()
		}
	}
}

[EDIT]:
If ReceiveSnapshots returns an error, conn.Write([]byte ) writes "1", the cliente receives it, execute SendSnapshotIncremental (it does if n != 0) and close the connection in client side... But, if ReceiveSnapshot does not return an error, conn.Write([]byte ) does not write "0" just only I close the connection in server side with ctrl+C

I believe the problem is in these lines:

buff := make([]byte, 1024)
n, _ := conn.Read(buff)

n in this case is the number of bytes read, not the value of any of them.

I'd do:

buff := make([]byte, 1)
n,err := conn.Read(buff)
buff = buff[:n]
if len(buff) == 0 {
   //error
}

if(buff[0] != 0){...

[Edit & Solved]

Several modifications to solve this...

Server:

func handleRequest(conn net.Conn) {
	// Number of snapshots in server side
	take, _ := zfs.Snapshots("tank/replication")
	count := len(take)
	if count < 1 {
		conn.Write([]byte("0"))
	} else {
		conn.Write([]byte("1"))
	}

	// Receive snapshot
	zfs.ReceiveSnapshot(conn, "tank/replication")
}

count returns the number of snapshots that server has, so if there are nothing, the client will execute the case, in other case the default.

Client:

func main() {
	// Get the last two snapshots
	take, _ := zfs.Snapshots("tank/test")
	snap := take[0].Name
	ds1, _ := zfs.GetDataset(snap)
	snap = take[1].Name
	ds2, _ := zfs.GetDataset(snap)

	// New server connection
	conn, _ := net.Dial("tcp", "192.168.99.5:7766")

	// Read data of server side
	buff := bufio.NewReader(conn)
	n, _ := buff.ReadByte()

	// Execute the correct case
	switch string(n) {
	case "0":
		ds1.SendSnapshot(conn)
		conn.Close()
	default :
		zfs.SendSnapshotIncremental(conn, ds1, ds2, zfs.IncrementalStream)
		conn.Close()
	}
}

I don't know if it's so good this solution but it works!