-
-
Save NikitaDef/5ee453e27c685d853bc070ec75b056e7 to your computer and use it in GitHub Desktop.
Golang TCP Proxy
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| package proxy | |
| import ( | |
| "io" | |
| "net" | |
| "sync" | |
| log "github.com/Sirupsen/logrus" | |
| ) | |
| type Proxy struct { | |
| from string | |
| to string | |
| done chan struct{} | |
| log *log.Entry | |
| } | |
| func NewProxy(from, to string) *Proxy { | |
| return &Proxy{ | |
| from: from, | |
| to: to, | |
| done: make(chan struct{}), | |
| log: log.WithFields(log.Fields{ | |
| "from": from, | |
| "to": to, | |
| }), | |
| } | |
| } | |
| func (p *Proxy) Start() error { | |
| p.log.Infoln("Starting proxy") | |
| listener, err := net.Listen("tcp", p.from) | |
| if err != nil { | |
| return err | |
| } | |
| go p.run(listener) | |
| return nil | |
| } | |
| func (p *Proxy) Stop() { | |
| p.log.Infoln("Stopping proxy") | |
| if p.done == nil { | |
| return | |
| } | |
| close(p.done) | |
| p.done = nil | |
| } | |
| func (p *Proxy) run(listener net.Listener) { | |
| for { | |
| select { | |
| case <-p.done: | |
| return | |
| default: | |
| connection, err := listener.Accept() | |
| if err == nil { | |
| go p.handle(connection) | |
| } else { | |
| p.log.WithField("err", err).Errorln("Error accepting conn") | |
| } | |
| } | |
| } | |
| } | |
| func (p *Proxy) handle(connection net.Conn) { | |
| p.log.Debugln("Handling", connection) | |
| defer p.log.Debugln("Done handling", connection) | |
| defer connection.Close() | |
| remote, err := net.Dial("tcp", p.to) | |
| if err != nil { | |
| p.log.WithField("err", err).Errorln("Error dialing remote host") | |
| return | |
| } | |
| defer remote.Close() | |
| wg := &sync.WaitGroup{} | |
| wg.Add(2) | |
| go p.copy(remote, connection, wg) | |
| go p.copy(connection, remote, wg) | |
| wg.Wait() | |
| } | |
| func (p *Proxy) copy(from, to net.Conn, wg *sync.WaitGroup) { | |
| defer wg.Done() | |
| select { | |
| case <-p.done: | |
| return | |
| default: | |
| if _, err := io.Copy(to, from); err != nil { | |
| p.log.WithField("err", err).Errorln("Error from copy") | |
| p.Stop() | |
| return | |
| } | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment