// TcpListen is listening for incoming IP packets which are being intercepted.
// In conflict to regular Listen mehtod the socket destination and source addresses
// are of the intercepted connection.
// Else then that it works exactly like net package net.Listen.
func TcpListen(listenAddr string) (listener net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET6, unix.SOCK_STREAM, 0)
if err != nil {
return nil, err
}
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
if err != nil {
return nil, err
}
sa, err := IPv6TcpAddrToUnixSocksAddr(listenAddr)
if err != nil {
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
return nil, err
}
err = unix.Listen(s, unix.SOMAXCONN)
if err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "TProxy")
defer f.Close()
return net.FileListener(f)
}
//network is useless ,it will always use tcp4
func TfoListen(network string, listenAddr string) (listener net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
if err != nil {
return nil, err
}
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, 10)
if err != nil {
return nil, err
}
err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
if err != nil {
return nil, err
}
sa, err := kmgUnix.IPv4TcpAddrToUnixSocksAddr(listenAddr)
if err != nil {
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
return nil, err
}
err = unix.Listen(s, 10)
if err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "TFOListen")
defer f.Close()
return net.FileListener(f)
}
// TfoListen announces on the local network address laddr using tcp protocol and fast open option.
// laddr must be in the form of "host:port".
// It returns a tfo-enabled listener and an error if any.
func tfoListen(laddr string) (lst net.Listener, err error) {
s, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
if err != nil {
return
}
defer unix.Close(s)
sa, err := tcpAddrToSockaddr(laddr)
if err != nil {
return
}
err = unix.Bind(s, sa)
if err != nil {
return
}
// set the socket to fast open mode
err = unix.SetsockoptInt(s, unix.SOL_TCP, 23, TCP_FASTOPEN_VAL)
if err != nil {
return
}
err = unix.Listen(s, 10)
if err != nil {
return
}
f := os.NewFile(uintptr(s), "TFOListen")
defer f.Close()
return net.FileListener(f)
}
func UdpTProxyConn(listenAddr string) (udp *net.UDPConn, err error) {
var c net.Conn
s, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, 0)
if err != nil {
return nil, err
}
//Why close here ???
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
if err != nil {
return nil, err
}
err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_BROADCAST, 1)
if err != nil {
return nil, err
}
err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
if err != nil {
return nil, err
}
err = unix.SetsockoptInt(s, unix.IPPROTO_IP, unix.IP_RECVORIGDSTADDR, 1)
if err != nil {
return nil, err
}
sa, err := IPv6TcpAddrToUnixSocksAddr(listenAddr)
if err != nil {
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "TProxy")
defer f.Close()
c, err = net.FileConn(f)
if err != nil {
return nil, err
}
var ok bool
if udp, ok = c.(*net.UDPConn); ok {
return
} else {
c.Close()
return nil, errors.New("type error")
}
}
func NewPacketSock(ifindex int) (*packetSock, error) {
fd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_DGRAM, int(swap16(unix.ETH_P_IP)))
if err != nil {
return nil, err
}
addr := unix.SockaddrLinklayer{
Ifindex: ifindex,
Protocol: swap16(unix.ETH_P_IP),
}
if err = unix.Bind(fd, &addr); err != nil {
return nil, err
}
return &packetSock{
fd: fd,
ifindex: ifindex,
}, nil
}
func open(fd, id int) (*Socket, error) {
// Reset the device in case previous session didn't cleanup properly.
if err := ioctl(uintptr(fd), hciDownDevice, uintptr(id)); err != nil {
return nil, errors.Wrap(err, "can't down device")
}
if err := ioctl(uintptr(fd), hciUpDevice, uintptr(id)); err != nil {
return nil, errors.Wrap(err, "can't up device")
}
// HCI User Channel requires exclusive access to the device.
// The device has to be down at the time of binding.
if err := ioctl(uintptr(fd), hciDownDevice, uintptr(id)); err != nil {
return nil, errors.Wrap(err, "can't down device")
}
// Bind the RAW socket to HCI User Channel
sa := unix.SockaddrHCI{Dev: uint16(id), Channel: unix.HCI_CHANNEL_USER}
if err := unix.Bind(fd, &sa); err != nil {
return nil, errors.Wrap(err, "can't bind socket to hci user channel")
}
return &Socket{fd: fd}, nil
}
// see also https://github.com/jbenet/go-reuseport/blob/master/impl_unix.go#L279
func NewSocket(addr *net.UDPAddr, recvBuf int) (net.PacketConn, error) {
sockFD, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM|syscall.SOCK_CLOEXEC|syscall.SOCK_NONBLOCK, 0)
if err != nil {
return nil, err
}
// unix.SO_REUSEPORT is not defined on linux 386/amd64, see
// https://github.com/golang/go/issues/16075
if err := unix.SetsockoptInt(sockFD, unix.SOL_SOCKET, 0xf, 1); err != nil {
return nil, err
}
if err := unix.SetsockoptInt(sockFD, unix.SOL_SOCKET, unix.SO_RCVBUF, recvBuf); err != nil {
return nil, err
}
sockaddr := unix.SockaddrInet4{
Port: addr.Port,
}
if copied := copy(sockaddr.Addr[:], addr.IP); copied != net.IPv4len {
panic("did not copy enough bytes of ip address")
}
if err := unix.Bind(sockFD, &sockaddr); err != nil {
return nil, err
}
osFD := os.NewFile(uintptr(sockFD), "veneursock")
// this will close the FD we passed to NewFile
defer osFD.Close()
// however, FilePacketConn duplicates the FD, so closing the File's FD does
// not affect this object's FD
ret, err := net.FilePacketConn(osFD)
if err != nil {
return nil, err
}
return ret, nil
}
func main() {
fmt.Println("Listening on port :", port)
counter := new(connCounter)
// create socket
fd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0)
if err != nil {
log.Fatal("socket-error: ", err)
}
// sa struct
sa := new(unix.SockaddrInet4)
sa.Port = 9090
// bind
err = unix.Bind(fd, sa)
if err != nil {
log.Fatal("bind: ", err)
}
// listen
err = unix.Listen(fd, 3)
if err != nil {
log.Fatal("listen: ", err)
}
for {
connInfo := new(connection)
// accept connection, discard SA struct
newFd, _, err := unix.Accept(fd)
connInfo.fd = newFd
if err != nil {
log.Fatal("accept: ", err)
}
// client reads until closes, adding
// a gorutine allows dealing with more
// requests.
counter.mu.Lock()
counter.num += 1
counter.mu.Unlock()
fmt.Println("Number of connections: ", counter.num)
go func(c *connection, counter *connCounter) {
fmt.Printf("Conn.fd=%d\n", c.fd)
for {
// read
c.buf = make([]byte, 50)
n, err := unix.Read(c.fd, c.buf)
if err != nil {
log.Fatal("read: ", err)
}
fmt.Printf("Read: %d Value: %s\n", n, string(c.buf[0:n]))
// close
if string(c.buf[0:5]) == "close" {
_, err = unix.Write(c.fd, []byte(`Bye bye buddy`))
if err != nil {
log.Fatal("close: ", err)
}
err = unix.Close(c.fd)
if err != nil {
log.Fatal("close: ", err)
}
counter.mu.Lock()
counter.num = counter.num - 1
counter.mu.Unlock()
return
}
}
}(connInfo, counter)
}
}
// TcpDial is a special tcp connection which binds a non local address as the source.
// Except then the option to bind to a specific local address which the machine doesn't posses
// it is exactly like any other net.Conn connection.
// It is advised to use port numbered 0 in the localAddr and leave the kernel to choose which
// Local port to use in order to avoid errors and binding conflicts.
func TcpDial(localAddr, remoteAddr string) (conn net.Conn, err error) {
fmt.Println(localAddr)
fmt.Println(remoteAddr)
s, err := unix.Socket(unix.AF_INET6, unix.SOCK_STREAM, 0)
//In a case there was a need for a non-blocking socket an example
//s, err := unix.Socket(unix.AF_INET6, unix.SOCK_STREAM |unix.SOCK_NONBLOCK, 0)
if err != nil {
fmt.Println(err)
return nil, err
}
defer unix.Close(s)
err = unix.SetsockoptInt(s, unix.SOL_IP, unix.IP_TRANSPARENT, 1)
if err != nil {
fmt.Println(err)
return nil, err
}
err = unix.SetsockoptInt(s, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
if err != nil {
fmt.Println(err)
return nil, err
}
rhost, rport, err := net.SplitHostPort(localAddr)
_ = rport
if err != nil {
fmt.Fprintln(os.Stderr, err)
}
sa, err := IPv6TcpAddrToUnixSocksAddr(rhost + ":0")
if err != nil {
fmt.Println(err)
return nil, err
}
remoteSocket, err := IPv6TcpAddrToUnixSocksAddr(remoteAddr)
if err != nil {
fmt.Println(err)
return nil, err
}
err = unix.Bind(s, sa)
if err != nil {
fmt.Println(err)
return nil, err
}
err = unix.Connect(s, remoteSocket)
if err != nil {
fmt.Println(err)
return nil, err
}
f := os.NewFile(uintptr(s), "TProxyTcpClient")
client, err := net.FileConn(f)
if err != nil {
fmt.Println(err)
return nil, err
}
fmt.Println(client.LocalAddr())
fmt.Println(client.RemoteAddr())
return client, err
}