conduit/tunnel/http_forwarder.go
Evan Reichard 7c1c22d214
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continuous-integration/drone/push Build is failing
feat: add tunnel monitor web ui
2025-10-12 14:55:27 -04:00

157 lines
3.5 KiB
Go

package tunnel
import (
"context"
"fmt"
"net"
"net/http"
"net/http/httputil"
"net/url"
"sync"
"reichard.io/conduit/store"
)
func newHTTPForwarder(targetURL *url.URL, tunnelStore store.TunnelStore) (Forwarder, error) {
return &httpConnBuilder{
multiConnListener: newMultiConnListener(),
tunnelStore: tunnelStore,
targetURL: targetURL,
}, nil
}
type httpConnBuilder struct {
multiConnListener *multiConnListener
tunnelStore store.TunnelStore
targetURL *url.URL
}
func (c *httpConnBuilder) Type() ForwarderType {
return ForwarderHTTP
}
func (c *httpConnBuilder) Start(ctx context.Context) error {
// Create Reverse Proxy Server
server := &http.Server{
ConnContext: func(ctx context.Context, c net.Conn) context.Context {
if wsConn, ok := c.(*wsConn); ok {
return context.WithValue(ctx, "sourceAddr", wsConn.sourceAddress)
}
return ctx
},
Handler: &httputil.ReverseProxy{
Director: func(req *http.Request) {
// Rewrite Request URL
req.Host = c.targetURL.Host
req.URL.Host = c.targetURL.Host
req.URL.Scheme = c.targetURL.Scheme
// Rewrite Referer
if referer := req.Header.Get("Referer"); referer != "" {
if refURL, err := url.Parse(referer); err == nil {
refURL.Host = c.targetURL.Host
refURL.Scheme = c.targetURL.Scheme
req.Header.Set("Referer", refURL.String())
}
}
// Extract Source Address & Record Request
sourceAddress, _ := req.Context().Value("sourceAddr").(string)
c.tunnelStore.RecordRequest(req, sourceAddress)
},
ModifyResponse: c.tunnelStore.RecordResponse,
ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
http.Error(w, fmt.Sprintf("Proxy error: %v", err), http.StatusBadGateway)
},
},
}
// Context & Cleanup
go func() {
<-ctx.Done()
server.Shutdown(ctx)
c.multiConnListener.Close()
}()
// Start HTTP Proxy
if err := server.Serve(c.multiConnListener); err != nil && err != http.ErrServerClosed {
return err
}
return nil
}
func (c *httpConnBuilder) Initialize(sourceAddress string) (Stream, error) {
clientConn, serverConn := net.Pipe()
if err := c.multiConnListener.addConn(&wsConn{serverConn, sourceAddress}); err != nil {
_ = clientConn.Close()
_ = serverConn.Close()
return nil, err
}
return &streamImpl{clientConn, sourceAddress, c.targetURL.String()}, nil
}
type multiConnListener struct {
connCh chan net.Conn
closed chan struct{}
once sync.Once
}
func newMultiConnListener() *multiConnListener {
return &multiConnListener{
connCh: make(chan net.Conn, 100),
closed: make(chan struct{}),
}
}
func (l *multiConnListener) Accept() (net.Conn, error) {
select {
case conn := <-l.connCh:
if conn == nil {
return nil, fmt.Errorf("listener closed")
}
return conn, nil
case <-l.closed:
return nil, fmt.Errorf("listener closed")
}
}
func (l *multiConnListener) Close() error {
l.once.Do(func() {
close(l.closed)
// Drain any remaining connections
go func() {
for conn := range l.connCh {
if conn != nil {
conn.Close()
}
}
}()
close(l.connCh)
})
return nil
}
func (l *multiConnListener) Addr() net.Addr {
return &net.TCPAddr{IP: net.IPv4(127, 0, 0, 1), Port: 0}
}
func (l *multiConnListener) addConn(conn net.Conn) error {
select {
case l.connCh <- conn:
return nil
case <-l.closed:
conn.Close()
return fmt.Errorf("listener is closed")
default:
conn.Close()
return fmt.Errorf("connection queue full")
}
}
type wsConn struct {
net.Conn
sourceAddress string
}