116 lines
2.9 KiB
Go
116 lines
2.9 KiB
Go
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package tunnel
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import (
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"bytes"
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"fmt"
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"io"
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"io/ioutil"
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"net"
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"net/http"
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"github.com/koding/logging"
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"git.xeserv.us/xena/route/lib/tunnel/proto"
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)
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var (
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httpLog = logging.NewLogger("http")
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)
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// HTTPProxy forwards HTTP traffic.
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//
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// When tunnel server requests a connection it's proxied to 127.0.0.1:incomingPort
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// 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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//
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// When connection to local server cannot be established proxy responds with http error message.
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type HTTPProxy 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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// ErrorResp is custom response send to tunnel server when client cannot
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// establish connection to local server. If not set a default "no local server"
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// response is sent.
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ErrorResp *http.Response
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// Log is a custom logger that can be used for the proxy.
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// If not set a "http" 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 *HTTPProxy) Proxy(remote net.Conn, msg *proto.ControlMessage) {
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if msg.Protocol != proto.HTTP && msg.Protocol != proto.WS {
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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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port = 80
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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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p.sendError(remote)
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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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p.sendError(remote)
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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 *HTTPProxy) sendError(remote net.Conn) {
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var w = noLocalServer()
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if p.ErrorResp != nil {
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w = p.ErrorResp
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}
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buf := new(bytes.Buffer)
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w.Write(buf)
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if _, err := io.Copy(remote, buf); err != nil {
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var log = p.log()
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log.Debug("Copy in-mem response error: %s", err)
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}
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remote.Close()
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}
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func noLocalServer() *http.Response {
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body := bytes.NewBufferString("no local server")
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return &http.Response{
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Status: http.StatusText(http.StatusServiceUnavailable),
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StatusCode: http.StatusServiceUnavailable,
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Proto: "HTTP/1.1",
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ProtoMajor: 1,
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ProtoMinor: 1,
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Body: ioutil.NopCloser(body),
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ContentLength: int64(body.Len()),
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}
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}
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func (p *HTTPProxy) 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 httpLog
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}
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