From 9244f87dc1c8869a2632176f719e515217720a43 Mon Sep 17 00:00:00 2001
From: Tristan-Wilson <87238672+Tristan-Wilson@users.noreply.github.com>
Date: Wed, 3 Aug 2022 07:50:12 -0700
Subject: [PATCH] node, rpc: add ReadHeaderTimeout config option (#25338)

This change makes http.Server.ReadHeaderTimeout configurable separately
from ReadTimeout for RPC servers. The default is set to the same as
ReadTimeout, which in order to cause no change in existing deployments.
---
 node/endpoints.go | 13 +++++++++----
 node/rpcstack.go  |  1 +
 rpc/http.go       | 15 ++++++++++++---
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/node/endpoints.go b/node/endpoints.go
index efc311e7e3..14c12fd1f1 100644
--- a/node/endpoints.go
+++ b/node/endpoints.go
@@ -39,10 +39,11 @@ func StartHTTPEndpoint(endpoint string, timeouts rpc.HTTPTimeouts, handler http.
 	CheckTimeouts(&timeouts)
 	// Bundle and start the HTTP server
 	httpSrv := &http.Server{
-		Handler:      handler,
-		ReadTimeout:  timeouts.ReadTimeout,
-		WriteTimeout: timeouts.WriteTimeout,
-		IdleTimeout:  timeouts.IdleTimeout,
+		Handler:           handler,
+		ReadTimeout:       timeouts.ReadTimeout,
+		ReadHeaderTimeout: timeouts.ReadHeaderTimeout,
+		WriteTimeout:      timeouts.WriteTimeout,
+		IdleTimeout:       timeouts.IdleTimeout,
 	}
 	go httpSrv.Serve(listener)
 	return httpSrv, listener.Addr(), err
@@ -75,6 +76,10 @@ func CheckTimeouts(timeouts *rpc.HTTPTimeouts) {
 		log.Warn("Sanitizing invalid HTTP read timeout", "provided", timeouts.ReadTimeout, "updated", rpc.DefaultHTTPTimeouts.ReadTimeout)
 		timeouts.ReadTimeout = rpc.DefaultHTTPTimeouts.ReadTimeout
 	}
+	if timeouts.ReadHeaderTimeout < time.Second {
+		log.Warn("Sanitizing invalid HTTP read header timeout", "provided", timeouts.ReadHeaderTimeout, "updated", rpc.DefaultHTTPTimeouts.ReadHeaderTimeout)
+		timeouts.ReadHeaderTimeout = rpc.DefaultHTTPTimeouts.ReadHeaderTimeout
+	}
 	if timeouts.WriteTimeout < time.Second {
 		log.Warn("Sanitizing invalid HTTP write timeout", "provided", timeouts.WriteTimeout, "updated", rpc.DefaultHTTPTimeouts.WriteTimeout)
 		timeouts.WriteTimeout = rpc.DefaultHTTPTimeouts.WriteTimeout
diff --git a/node/rpcstack.go b/node/rpcstack.go
index 9b5873e90a..5d411fa61e 100644
--- a/node/rpcstack.go
+++ b/node/rpcstack.go
@@ -134,6 +134,7 @@ func (h *httpServer) start() error {
 	if h.timeouts != (rpc.HTTPTimeouts{}) {
 		CheckTimeouts(&h.timeouts)
 		h.server.ReadTimeout = h.timeouts.ReadTimeout
+		h.server.ReadHeaderTimeout = h.timeouts.ReadHeaderTimeout
 		h.server.WriteTimeout = h.timeouts.WriteTimeout
 		h.server.IdleTimeout = h.timeouts.IdleTimeout
 	}
diff --git a/rpc/http.go b/rpc/http.go
index 9f44649573..858d808586 100644
--- a/rpc/http.go
+++ b/rpc/http.go
@@ -87,6 +87,14 @@ type HTTPTimeouts struct {
 	// ReadHeaderTimeout. It is valid to use them both.
 	ReadTimeout time.Duration
 
+	// ReadHeaderTimeout is the amount of time allowed to read
+	// request headers. The connection's read deadline is reset
+	// after reading the headers and the Handler can decide what
+	// is considered too slow for the body. If ReadHeaderTimeout
+	// is zero, the value of ReadTimeout is used. If both are
+	// zero, there is no timeout.
+	ReadHeaderTimeout time.Duration
+
 	// WriteTimeout is the maximum duration before timing out
 	// writes of the response. It is reset whenever a new
 	// request's header is read. Like ReadTimeout, it does not
@@ -103,9 +111,10 @@ type HTTPTimeouts struct {
 // DefaultHTTPTimeouts represents the default timeout values used if further
 // configuration is not provided.
 var DefaultHTTPTimeouts = HTTPTimeouts{
-	ReadTimeout:  30 * time.Second,
-	WriteTimeout: 30 * time.Second,
-	IdleTimeout:  120 * time.Second,
+	ReadTimeout:       30 * time.Second,
+	ReadHeaderTimeout: 30 * time.Second,
+	WriteTimeout:      30 * time.Second,
+	IdleTimeout:       120 * time.Second,
 }
 
 // DialHTTPWithClient creates a new RPC client that connects to an RPC server over HTTP