Fix Jellyfin

Services like Jellyfin weren't working apparently because the upstream
requests were using chunked encoding. Reading the entire request body
and forwarding it on seems to fix it.

Also overriding the Host header for upstream requests.

boringproxy.go

@@ -2,11 +2,13 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/tls"
 	"flag"
 	"fmt"
 	"github.com/caddyserver/certmagic"
 	"io"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -156,7 +158,15 @@ func (p *BoringProxy) proxyRequest(w http.ResponseWriter, r *http.Request) {
 	upstreamAddr := fmt.Sprintf("localhost:%d", tunnel.TunnelPort)
 	upstreamUrl := fmt.Sprintf("http://%s%s", upstreamAddr, r.URL.RequestURI())
 
-	upstreamReq, err := http.NewRequest(r.Method, upstreamUrl, r.Body)
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		errMessage := fmt.Sprintf("%s", err)
+		w.WriteHeader(500)
+		io.WriteString(w, errMessage)
+		return
+	}
+
+	upstreamReq, err := http.NewRequest(r.Method, upstreamUrl, bytes.NewReader(body))
 	if err != nil {
 		errMessage := fmt.Sprintf("%s", err)
 		w.WriteHeader(500)
@@ -167,6 +177,7 @@ func (p *BoringProxy) proxyRequest(w http.ResponseWriter, r *http.Request) {
 	upstreamReq.Header = downstreamReqHeaders
 
 	upstreamReq.Header["X-Forwarded-Host"] = []string{r.Host}
+	upstreamReq.Host = fmt.Sprintf("%s:%d", tunnel.ClientAddress, tunnel.ClientPort)
 
 	upstreamRes, err := p.httpClient.Do(upstreamReq)
 	if err != nil {