57 lines
1.3 KiB
Go
57 lines
1.3 KiB
Go
package channel
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import (
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"fmt"
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"net"
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"time"
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"github.com/gorilla/websocket"
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)
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// ANSI "end of channel" code
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var eot = []byte{0x04}
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// An abstraction of gorilla's *websocket.Conn
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type Connection interface {
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UnderlyingConn() net.Conn
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ReadMessage() (int, []byte, error)
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WriteMessage(int, []byte) error
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WriteControl(int, []byte, time.Time) error
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}
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type Proxy struct {
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StopCh chan error
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}
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// stoppers is the number of goroutines that may attempt to call Stop()
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func NewProxy(stoppers int) *Proxy {
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return &Proxy{
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StopCh: make(chan error, stoppers+2), // each proxy() call is a stopper
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}
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}
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func (p *Proxy) Serve(upstream, downstream Connection, upstreamAddr, downstreamAddr string) error {
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// This signals the upstream channel to kill the exec'd process
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defer upstream.WriteMessage(websocket.BinaryMessage, eot)
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go p.proxy(upstream, downstream, upstreamAddr, downstreamAddr)
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go p.proxy(downstream, upstream, downstreamAddr, upstreamAddr)
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return <-p.StopCh
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}
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func (p *Proxy) proxy(to, from Connection, toAddr, fromAddr string) {
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for {
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messageType, data, err := from.ReadMessage()
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if err != nil {
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p.StopCh <- fmt.Errorf("reading from %s: %s", fromAddr, err)
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break
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}
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if err := to.WriteMessage(messageType, data); err != nil {
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p.StopCh <- fmt.Errorf("writing to %s: %s", toAddr, err)
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break
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}
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}
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}
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