forked from bettercap/bettercap
/
tcp_proxy.go
218 lines (177 loc) · 5.02 KB
/
tcp_proxy.go
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package modules
import (
"fmt"
"io"
"net"
"sync"
"github.com/bettercap/bettercap/firewall"
"github.com/bettercap/bettercap/log"
"github.com/bettercap/bettercap/session"
)
type TcpProxy struct {
session.SessionModule
Redirection *firewall.Redirection
localAddr *net.TCPAddr
remoteAddr *net.TCPAddr
listener *net.TCPListener
script *TcpProxyScript
}
func NewTcpProxy(s *session.Session) *TcpProxy {
p := &TcpProxy{
SessionModule: session.NewSessionModule("tcp.proxy", s),
}
p.AddParam(session.NewIntParameter("tcp.port",
"443",
"Remote port to redirect when the TCP proxy is activated."))
p.AddParam(session.NewStringParameter("tcp.address",
"",
session.IPv4Validator,
"Remote address of the TCP proxy."))
p.AddParam(session.NewStringParameter("tcp.proxy.address",
session.ParamIfaceAddress,
session.IPv4Validator,
"Address to bind the TCP proxy to."))
p.AddParam(session.NewIntParameter("tcp.proxy.port",
"8443",
"Port to bind the TCP proxy to."))
p.AddParam(session.NewStringParameter("tcp.proxy.script",
"",
"",
"Path of a TCP proxy JS script."))
p.AddHandler(session.NewModuleHandler("tcp.proxy on", "",
"Start TCP proxy.",
func(args []string) error {
return p.Start()
}))
p.AddHandler(session.NewModuleHandler("tcp.proxy off", "",
"Stop TCP proxy.",
func(args []string) error {
return p.Stop()
}))
return p
}
func (p *TcpProxy) Name() string {
return "tcp.proxy"
}
func (p *TcpProxy) Description() string {
return "A full featured TCP proxy, all TCP traffic to a given remote address and port will be redirected to it."
}
func (p *TcpProxy) Author() string {
return "Simone Margaritelli <evilsocket@protonmail.com>"
}
func (p *TcpProxy) Configure() error {
var err error
var port int
var proxyPort int
var address string
var proxyAddress string
var scriptPath string
if p.Running() == true {
return session.ErrAlreadyStarted
} else if err, address = p.StringParam("tcp.address"); err != nil {
return err
} else if err, proxyAddress = p.StringParam("tcp.proxy.address"); err != nil {
return err
} else if err, proxyPort = p.IntParam("tcp.proxy.port"); err != nil {
return err
} else if err, port = p.IntParam("tcp.port"); err != nil {
return err
} else if err, scriptPath = p.StringParam("tcp.proxy.script"); err != nil {
return err
} else if p.localAddr, err = net.ResolveTCPAddr("tcp", fmt.Sprintf("%s:%d", proxyAddress, proxyPort)); err != nil {
return err
} else if p.remoteAddr, err = net.ResolveTCPAddr("tcp", fmt.Sprintf("%s:%d", address, port)); err != nil {
return err
} else if p.listener, err = net.ListenTCP("tcp", p.localAddr); err != nil {
return err
}
if scriptPath != "" {
if err, p.script = LoadTcpProxyScript(scriptPath, p.Session); err != nil {
return err
} else {
log.Debug("TCP proxy script %s loaded.", scriptPath)
}
}
if p.Session.Firewall.IsForwardingEnabled() == false {
log.Info("Enabling forwarding.")
p.Session.Firewall.EnableForwarding(true)
}
p.Redirection = firewall.NewRedirection(p.Session.Interface.Name(),
"TCP",
port,
proxyAddress,
proxyPort)
p.Redirection.SrcAddress = address
if err := p.Session.Firewall.EnableRedirection(p.Redirection, true); err != nil {
return err
}
log.Debug("Applied redirection %s", p.Redirection.String())
return nil
}
func (p *TcpProxy) doPipe(from, to net.Addr, src, dst io.ReadWriter, wg *sync.WaitGroup) {
defer wg.Done()
buff := make([]byte, 0xffff)
for {
n, err := src.Read(buff)
if err != nil {
if err.Error() != "EOF" {
log.Warning("Read failed: %s", err)
}
return
}
b := buff[:n]
if p.script != nil {
ret := p.script.OnData(from, to, b)
if ret != nil {
nret := len(ret)
log.Info("Overriding %d bytes of data from %s to %s with %d bytes of new data.",
n, from.String(), to.String(), nret)
b = make([]byte, nret)
copy(b, ret)
}
}
n, err = dst.Write(b)
if err != nil {
log.Warning("Write failed: %s", err)
return
}
log.Debug("%s -> %s : %d bytes", from.String(), to.String(), n)
}
}
func (p *TcpProxy) handleConnection(c *net.TCPConn) {
defer c.Close()
log.Info("TCP proxy got a connection from %s", c.RemoteAddr().String())
remote, err := net.DialTCP("tcp", nil, p.remoteAddr)
if err != nil {
log.Warning("Error while connecting to remote %s: %s", p.remoteAddr.String(), err)
return
}
defer remote.Close()
wg := sync.WaitGroup{}
wg.Add(2)
// start pipeing
go p.doPipe(c.RemoteAddr(), p.remoteAddr, c, remote, &wg)
go p.doPipe(p.remoteAddr, c.RemoteAddr(), remote, c, &wg)
wg.Wait()
}
func (p *TcpProxy) Start() error {
if err := p.Configure(); err != nil {
return err
}
return p.SetRunning(true, func() {
log.Info("TCP proxy started ( x -> %s -> %s )", p.localAddr, p.remoteAddr)
for p.Running() {
conn, err := p.listener.AcceptTCP()
if err != nil {
log.Warning("Error while accepting TCP connection: %s", err)
continue
}
go p.handleConnection(conn)
}
})
}
func (p *TcpProxy) Stop() error {
return p.SetRunning(false, func() {
p.listener.Close()
})
}