From 5c6207debc89ada56a63dfa4e73bf875a91e132d Mon Sep 17 00:00:00 2001
From: Sudarsan Reddy <sreddy@cloudflare.com>
Date: Fri, 4 Mar 2022 11:35:57 +0000
Subject: [PATCH]  TUN-5696: HTTP/2 Configuration Update

---
 connection/connection.go |  1 +
 connection/http2.go      | 35 +++++++++++++++++++++++++++++++++++
 connection/http2_test.go | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+)

diff --git a/connection/connection.go b/connection/connection.go
index 525c1a6e..ad14a85c 100644
--- a/connection/connection.go
+++ b/connection/connection.go
@@ -80,6 +80,7 @@ const (
 	TypeTCP
 	TypeControlStream
 	TypeHTTP
+	TypeConfiguration
 )
 
 // ShouldFlush returns whether this kind of connection should actively flush data
diff --git a/connection/http2.go b/connection/http2.go
index b015117c..55e73ad3 100644
--- a/connection/http2.go
+++ b/connection/http2.go
@@ -2,6 +2,7 @@ package connection
 
 import (
 	"context"
+	gojson "encoding/json"
 	"fmt"
 	"io"
 	"net"
@@ -23,6 +24,7 @@ const (
 	InternalTCPProxySrcHeader = "Cf-Cloudflared-Proxy-Src"
 	WebsocketUpgrade          = "websocket"
 	ControlStreamUpgrade      = "control-stream"
+	ConfigurationUpdate       = "update-configuration"
 )
 
 var errEdgeConnectionClosed = fmt.Errorf("connection with edge closed")
@@ -120,6 +122,13 @@ func (c *HTTP2Connection) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			respWriter.WriteErrorResponse()
 		}
 
+	case TypeConfiguration:
+		fmt.Println("TYPE CONFIGURATION?")
+		if err := c.handleConfigurationUpdate(respWriter, r); err != nil {
+			c.log.Error().Err(err)
+			respWriter.WriteErrorResponse()
+		}
+
 	case TypeWebsocket, TypeHTTP:
 		stripWebsocketUpgradeHeader(r)
 		if err := originProxy.ProxyHTTP(respWriter, r, connType == TypeWebsocket); err != nil {
@@ -152,6 +161,26 @@ func (c *HTTP2Connection) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// ConfigurationUpdateBody is the representation followed by the edge to send updates to cloudflared.
+type ConfigurationUpdateBody struct {
+	Version int32             `json:"version"`
+	Config  gojson.RawMessage `json:"config"`
+}
+
+func (c *HTTP2Connection) handleConfigurationUpdate(respWriter *http2RespWriter, r *http.Request) error {
+	var configBody ConfigurationUpdateBody
+	if err := json.NewDecoder(r.Body).Decode(&configBody); err != nil {
+		return err
+	}
+	resp := c.orchestrator.UpdateConfig(configBody.Version, configBody.Config)
+	bdy, err := json.Marshal(resp)
+	if err != nil {
+		return err
+	}
+	_, err = respWriter.Write(bdy)
+	return err
+}
+
 func (c *HTTP2Connection) close() {
 	// Wait for all serve HTTP handlers to return
 	c.activeRequestsWG.Wait()
@@ -258,6 +287,8 @@ func (rp *http2RespWriter) Close() error {
 
 func determineHTTP2Type(r *http.Request) Type {
 	switch {
+	case isConfigurationUpdate(r):
+		return TypeConfiguration
 	case isWebsocketUpgrade(r):
 		return TypeWebsocket
 	case IsTCPStream(r):
@@ -291,6 +322,10 @@ func isWebsocketUpgrade(r *http.Request) bool {
 	return r.Header.Get(InternalUpgradeHeader) == WebsocketUpgrade
 }
 
+func isConfigurationUpdate(r *http.Request) bool {
+	return r.Header.Get(InternalUpgradeHeader) == ConfigurationUpdate
+}
+
 // IsTCPStream discerns if the connection request needs a tcp stream proxy.
 func IsTCPStream(r *http.Request) bool {
 	return r.Header.Get(InternalTCPProxySrcHeader) != ""
diff --git a/connection/http2_test.go b/connection/http2_test.go
index c067229c..384d29fb 100644
--- a/connection/http2_test.go
+++ b/connection/http2_test.go
@@ -1,6 +1,7 @@
 package connection
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -53,6 +54,41 @@ func newTestHTTP2Connection() (*HTTP2Connection, net.Conn) {
 	), edgeConn
 }
 
+func TestHTTP2ConfigurationSet(t *testing.T) {
+	http2Conn, edgeConn := newTestHTTP2Connection()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		http2Conn.Serve(ctx)
+	}()
+
+	edgeHTTP2Conn, err := testTransport.NewClientConn(edgeConn)
+	require.NoError(t, err)
+
+	endpoint := fmt.Sprintf("http://localhost:8080/ok")
+	reqBody := []byte(`{
+"version": 2, 
+"config": {"warp-routing": {"enabled": true},  "originRequest" : {"connectTimeout": 10}, "ingress" : [ {"hostname": "test", "service": "https://localhost:8000" } , {"service": "http_status:404"} ]}}
+`)
+	reader := bytes.NewReader(reqBody)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPut, endpoint, reader)
+	require.NoError(t, err)
+	req.Header.Set(InternalUpgradeHeader, ConfigurationUpdate)
+
+	resp, err := edgeHTTP2Conn.RoundTrip(req)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+	bdy, err := ioutil.ReadAll(resp.Body)
+	require.NoError(t, err)
+	assert.Equal(t, `{"lastAppliedVersion":2,"err":null}`, string(bdy))
+	cancel()
+	wg.Wait()
+
+}
+
 func TestServeHTTP(t *testing.T) {
 	tests := []testRequest{
 		{