79 lines
2.1 KiB
Go
79 lines
2.1 KiB
Go
package tunnel
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import (
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"fmt"
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"net"
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"git.xeserv.us/xena/route/lib/tunnel/proto"
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"github.com/koding/logging"
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)
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var (
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tpcLog = logging.NewLogger("tcp")
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)
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// TCPProxy forwards TCP streams.
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//
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// If port-based routing is used, LocalAddr or FetchLocalAddr field is required
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// for tunneling to function properly.
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// Otherwise you'll be forwarding traffic to random ports and this is usually not desired.
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//
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// If IP-based routing is used then tunnel server connection request is
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// proxied to 127.0.0.1:incomingPort where incomingPort is control message LocalPort.
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// Usually this is tunnel server's public exposed Port.
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// This behaviour can be changed by setting LocalAddr or FetchLocalAddr.
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// FetchLocalAddr takes precedence over LocalAddr.
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type TCPProxy struct {
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// LocalAddr defines the TCP address of the local server.
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// This is optional if you want to specify a single TCP address.
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LocalAddr string
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// FetchLocalAddr is used for looking up TCP address of the server.
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// This is optional if you want to specify a dynamic TCP address based on incommig port.
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FetchLocalAddr func(port int) (string, error)
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// Log is a custom logger that can be used for the proxy.
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// If not set a "tcp" logger is used.
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Log logging.Logger
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}
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// Proxy is a ProxyFunc.
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func (p *TCPProxy) Proxy(remote net.Conn, msg *proto.ControlMessage) {
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if msg.Protocol != proto.TCP {
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panic("Proxy mismatch")
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}
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var log = p.log()
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var port = msg.LocalPort
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if port == 0 {
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log.Warning("TCP proxy to port 0")
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}
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var localAddr = fmt.Sprintf("127.0.0.1:%d", port)
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if p.LocalAddr != "" {
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localAddr = p.LocalAddr
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} else if p.FetchLocalAddr != nil {
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l, err := p.FetchLocalAddr(msg.LocalPort)
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if err != nil {
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log.Warning("Failed to get custom local address: %s", err)
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return
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}
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localAddr = l
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}
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log.Debug("Dialing local server: %q", localAddr)
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local, err := net.DialTimeout("tcp", localAddr, defaultTimeout)
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if err != nil {
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log.Error("Dialing local server %q failed: %s", localAddr, err)
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return
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}
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Join(local, remote, log)
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}
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func (p *TCPProxy) log() logging.Logger {
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if p.Log != nil {
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return p.Log
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}
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return tpcLog
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}
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