93 lines
2.1 KiB
Go
93 lines
2.1 KiB
Go
package tcp
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import (
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"io"
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"net"
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"time"
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"github.com/traefik/traefik/v2/pkg/log"
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)
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// Proxy forwards a TCP request to a TCP service.
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type Proxy struct {
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address string
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target *net.TCPAddr
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terminationDelay time.Duration
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refreshTarget bool
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}
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// NewProxy creates a new Proxy.
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func NewProxy(address string, terminationDelay time.Duration) (*Proxy, error) {
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tcpAddr, err := net.ResolveTCPAddr("tcp", address)
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if err != nil {
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return nil, err
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}
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// enable the refresh of the target only if the address in an IP
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refreshTarget := false
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if host, _, err := net.SplitHostPort(address); err == nil && net.ParseIP(host) == nil {
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refreshTarget = true
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}
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return &Proxy{
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address: address,
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target: tcpAddr,
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refreshTarget: refreshTarget,
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terminationDelay: terminationDelay,
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}, nil
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}
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// ServeTCP forwards the connection to a service.
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func (p *Proxy) ServeTCP(conn WriteCloser) {
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log.Debugf("Handling connection from %s", conn.RemoteAddr())
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// needed because of e.g. server.trackedConnection
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defer conn.Close()
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if p.refreshTarget {
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tcpAddr, err := net.ResolveTCPAddr("tcp", p.address)
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if err != nil {
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log.Errorf("Error resolving tcp address: %v", err)
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return
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}
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p.target = tcpAddr
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}
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connBackend, err := net.DialTCP("tcp", nil, p.target)
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if err != nil {
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log.Errorf("Error while connection to backend: %v", err)
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return
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}
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// maybe not needed, but just in case
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defer connBackend.Close()
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errChan := make(chan error)
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go p.connCopy(conn, connBackend, errChan)
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go p.connCopy(connBackend, conn, errChan)
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err = <-errChan
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if err != nil {
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log.WithoutContext().Errorf("Error during connection: %v", err)
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}
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<-errChan
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}
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func (p Proxy) connCopy(dst, src WriteCloser, errCh chan error) {
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_, err := io.Copy(dst, src)
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errCh <- err
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errClose := dst.CloseWrite()
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if errClose != nil {
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log.WithoutContext().Debugf("Error while terminating connection: %v", errClose)
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return
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}
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if p.terminationDelay >= 0 {
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err := dst.SetReadDeadline(time.Now().Add(p.terminationDelay))
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if err != nil {
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log.WithoutContext().Debugf("Error while setting deadline: %v", err)
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}
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}
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}
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