Add support for an HTTP reverse proxy

README.md

@@ -50,6 +50,26 @@ Configuration should look like this:
 ]
 ```
 
+There is also support for HTTP proxying:
+
+```json
+[
+ {
+ "from": 443,
+ "to": "http://127.0.0.1:8000/",
+ "tls": true,
+ "protocol": "http",
+ "http": {
+ "host": "localhost",
+ "headers": {
+ "User-Agent": "SomeAgent/2.0"
+ }
+ }
+ }
+]
+```
+
+
 ## Disclaimer
 
 THIS IS NOT OFFICIALLY ENDORSED BY TAILSCALE.

main.go

@@ -8,6 +8,9 @@ import (
  "io"
  "log"
  "net"
+ "net/http"
+ "net/http/httputil"
+ "net/url"
  "os"
  "sync"
 
@@ -16,9 +19,16 @@ import (
 )
 
 type Binding struct {
- From uint16 `json:"from"`
- To string `json:"to"`
- Tls bool `json:"tls"`
+ From uint16 `json:"from"`
+ To string `json:"to"`
+ Tls bool `json:"tls"`
+ Protocol string `json:"protocol"`
+ Http *HttpBinding `json:"http"`
+}
+
+type HttpBinding struct {
+ Host string `json:"host"`
+ Headers map[string]string `json:"headers"`
 }
 
 func loadBindings() ([]Binding, error) {
@@ -81,6 +91,60 @@ func proxyBind(s *tsnet.Server, b *Binding) {
  })
  }
 
+ if b.Protocol == "http" {
+ serveHTTP(b, ln)
+ } else if b.Protocol == "tcp" || b.Protocol == "" {
+ serveTCP(b, ln)
+ } else {
+ log.Printf("unknown protocol %q", b.Protocol)
+ }
+
+}
+
+func serveHTTP(b *Binding, ln net.Listener) {
+ uri, err := url.Parse(b.To)
+ if err != nil {
+ var err2 error
+ uri, err2 = url.Parse("http://" + b.To)
+ if err2 != nil {
+ log.Println(err)
+ return
+ }
+ }
+
+ proxy := httputil.NewSingleHostReverseProxy(uri)
+
+ if b.Http != nil {
+ originalDirector := proxy.Director
+ proxy.Director = func(req *http.Request) {
+ originalDirector(req)
+
+ for k, v := range b.Http.Headers {
+ req.Header.Set(k, v)
+ }
+
+ if b.Http.Host != "" {
+ req.Host = b.Http.Host
+ }
+ }
+ }
+
+ log.Printf("started proxy bind from %d to %v (tls: %t)", b.From, uri.String(), b.Tls)
+
+ mux := http.NewServeMux()
+
+ // handle all requests to your server using the proxy
+ mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+ proxy.ServeHTTP(w, r)
+ })
+
+ err = http.Serve(ln, mux)
+ if err != nil {
+ log.Println(err)
+ }
+}
+
+func serveTCP(b *Binding, ln net.Listener) {
  log.Printf("started proxy bind from %d to %v (tls: %t)", b.From, b.To, b.Tls)
 
  for {