diff --git a/vendor/golang.org/x/net/AUTHORS b/vendor/golang.org/x/net/AUTHORS
deleted file mode 100644
index 15167cd..0000000
--- a/vendor/golang.org/x/net/AUTHORS
+++ /dev/null
@@ -1,3 +0,0 @@
-# This source code refers to The Go Authors for copyright purposes.
-# The master list of authors is in the main Go distribution,
-# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/golang.org/x/net/CONTRIBUTORS b/vendor/golang.org/x/net/CONTRIBUTORS
deleted file mode 100644
index 1c4577e..0000000
--- a/vendor/golang.org/x/net/CONTRIBUTORS
+++ /dev/null
@@ -1,3 +0,0 @@
-# This source code was written by the Go contributors.
-# The master list of contributors is in the main Go distribution,
-# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/golang.org/x/net/http/httpguts/httplex.go b/vendor/golang.org/x/net/http/httpguts/httplex.go
index 3d7e0af..6e071e8 100644
--- a/vendor/golang.org/x/net/http/httpguts/httplex.go
+++ b/vendor/golang.org/x/net/http/httpguts/httplex.go
@@ -137,11 +137,13 @@
 // contains token amongst its comma-separated tokens, ASCII
 // case-insensitively.
 func headerValueContainsToken(v string, token string) bool {
-	v = trimOWS(v)
-	if comma := strings.IndexByte(v, ','); comma != -1 {
-		return tokenEqual(trimOWS(v[:comma]), token) || headerValueContainsToken(v[comma+1:], token)
+	for comma := strings.IndexByte(v, ','); comma != -1; comma = strings.IndexByte(v, ',') {
+		if tokenEqual(trimOWS(v[:comma]), token) {
+			return true
+		}
+		v = v[comma+1:]
 	}
-	return tokenEqual(v, token)
+	return tokenEqual(trimOWS(v), token)
 }
 
 // lowerASCII returns the ASCII lowercase version of b.
@@ -189,12 +191,13 @@
 // HTTP/2 imposes the additional restriction that uppercase ASCII
 // letters are not allowed.
 //
-//	RFC 7230 says:
-//	 header-field   = field-name ":" OWS field-value OWS
-//	 field-name     = token
-//	 token          = 1*tchar
-//	 tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." /
-//	         "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
+// RFC 7230 says:
+//
+//	header-field   = field-name ":" OWS field-value OWS
+//	field-name     = token
+//	token          = 1*tchar
+//	tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." /
+//	        "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
 func ValidHeaderFieldName(v string) bool {
 	if len(v) == 0 {
 		return false
diff --git a/vendor/golang.org/x/net/http2/Dockerfile b/vendor/golang.org/x/net/http2/Dockerfile
index 53fc525..8512245 100644
--- a/vendor/golang.org/x/net/http2/Dockerfile
+++ b/vendor/golang.org/x/net/http2/Dockerfile
@@ -38,7 +38,7 @@
 RUN make install
 
 WORKDIR /root
-RUN wget http://curl.haxx.se/download/curl-7.45.0.tar.gz
+RUN wget https://curl.se/download/curl-7.45.0.tar.gz
 RUN tar -zxvf curl-7.45.0.tar.gz
 WORKDIR /root/curl-7.45.0
 RUN ./configure --with-ssl --with-nghttp2=/usr/local
diff --git a/vendor/golang.org/x/net/http2/README b/vendor/golang.org/x/net/http2/README
deleted file mode 100644
index 360d5aa..0000000
--- a/vendor/golang.org/x/net/http2/README
+++ /dev/null
@@ -1,20 +0,0 @@
-This is a work-in-progress HTTP/2 implementation for Go.
-
-It will eventually live in the Go standard library and won't require
-any changes to your code to use.  It will just be automatic.
-
-Status:
-
-* The server support is pretty good. A few things are missing
-  but are being worked on.
-* The client work has just started but shares a lot of code
-  is coming along much quicker.
-
-Docs are at https://godoc.org/golang.org/x/net/http2
-
-Demo test server at https://http2.golang.org/
-
-Help & bug reports welcome!
-
-Contributing: https://golang.org/doc/contribute.html
-Bugs:         https://golang.org/issue/new?title=x/net/http2:+
diff --git a/vendor/golang.org/x/net/http2/ascii.go b/vendor/golang.org/x/net/http2/ascii.go
new file mode 100644
index 0000000..17caa20
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/ascii.go
@@ -0,0 +1,53 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import "strings"
+
+// The HTTP protocols are defined in terms of ASCII, not Unicode. This file
+// contains helper functions which may use Unicode-aware functions which would
+// otherwise be unsafe and could introduce vulnerabilities if used improperly.
+
+// asciiEqualFold is strings.EqualFold, ASCII only. It reports whether s and t
+// are equal, ASCII-case-insensitively.
+func asciiEqualFold(s, t string) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i := 0; i < len(s); i++ {
+		if lower(s[i]) != lower(t[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// lower returns the ASCII lowercase version of b.
+func lower(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+// isASCIIPrint returns whether s is ASCII and printable according to
+// https://tools.ietf.org/html/rfc20#section-4.2.
+func isASCIIPrint(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < ' ' || s[i] > '~' {
+			return false
+		}
+	}
+	return true
+}
+
+// asciiToLower returns the lowercase version of s if s is ASCII and printable,
+// and whether or not it was.
+func asciiToLower(s string) (lower string, ok bool) {
+	if !isASCIIPrint(s) {
+		return "", false
+	}
+	return strings.ToLower(s), true
+}
diff --git a/vendor/golang.org/x/net/http2/client_conn_pool.go b/vendor/golang.org/x/net/http2/client_conn_pool.go
index 3a67636..780968d 100644
--- a/vendor/golang.org/x/net/http2/client_conn_pool.go
+++ b/vendor/golang.org/x/net/http2/client_conn_pool.go
@@ -7,13 +7,21 @@
 package http2
 
 import (
+	"context"
 	"crypto/tls"
+	"errors"
 	"net/http"
 	"sync"
 )
 
 // ClientConnPool manages a pool of HTTP/2 client connections.
 type ClientConnPool interface {
+	// GetClientConn returns a specific HTTP/2 connection (usually
+	// a TLS-TCP connection) to an HTTP/2 server. On success, the
+	// returned ClientConn accounts for the upcoming RoundTrip
+	// call, so the caller should not omit it. If the caller needs
+	// to, ClientConn.RoundTrip can be called with a bogus
+	// new(http.Request) to release the stream reservation.
 	GetClientConn(req *http.Request, addr string) (*ClientConn, error)
 	MarkDead(*ClientConn)
 }
@@ -40,7 +48,7 @@
 	conns        map[string][]*ClientConn // key is host:port
 	dialing      map[string]*dialCall     // currently in-flight dials
 	keys         map[*ClientConn][]string
-	addConnCalls map[string]*addConnCall // in-flight addConnIfNeede calls
+	addConnCalls map[string]*addConnCall // in-flight addConnIfNeeded calls
 }
 
 func (p *clientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) {
@@ -52,88 +60,85 @@
 	noDialOnMiss = false
 )
 
-// shouldTraceGetConn reports whether getClientConn should call any
-// ClientTrace.GetConn hook associated with the http.Request.
-//
-// This complexity is needed to avoid double calls of the GetConn hook
-// during the back-and-forth between net/http and x/net/http2 (when the
-// net/http.Transport is upgraded to also speak http2), as well as support
-// the case where x/net/http2 is being used directly.
-func (p *clientConnPool) shouldTraceGetConn(st clientConnIdleState) bool {
-	// If our Transport wasn't made via ConfigureTransport, always
-	// trace the GetConn hook if provided, because that means the
-	// http2 package is being used directly and it's the one
-	// dialing, as opposed to net/http.
-	if _, ok := p.t.ConnPool.(noDialClientConnPool); !ok {
-		return true
-	}
-	// Otherwise, only use the GetConn hook if this connection has
-	// been used previously for other requests. For fresh
-	// connections, the net/http package does the dialing.
-	return !st.freshConn
-}
-
 func (p *clientConnPool) getClientConn(req *http.Request, addr string, dialOnMiss bool) (*ClientConn, error) {
+	// TODO(dneil): Dial a new connection when t.DisableKeepAlives is set?
 	if isConnectionCloseRequest(req) && dialOnMiss {
 		// It gets its own connection.
 		traceGetConn(req, addr)
 		const singleUse = true
-		cc, err := p.t.dialClientConn(addr, singleUse)
+		cc, err := p.t.dialClientConn(req.Context(), addr, singleUse)
 		if err != nil {
 			return nil, err
 		}
 		return cc, nil
 	}
-	p.mu.Lock()
-	for _, cc := range p.conns[addr] {
-		if st := cc.idleState(); st.canTakeNewRequest {
-			if p.shouldTraceGetConn(st) {
-				traceGetConn(req, addr)
+	for {
+		p.mu.Lock()
+		for _, cc := range p.conns[addr] {
+			if cc.ReserveNewRequest() {
+				// When a connection is presented to us by the net/http package,
+				// the GetConn hook has already been called.
+				// Don't call it a second time here.
+				if !cc.getConnCalled {
+					traceGetConn(req, addr)
+				}
+				cc.getConnCalled = false
+				p.mu.Unlock()
+				return cc, nil
 			}
+		}
+		if !dialOnMiss {
 			p.mu.Unlock()
+			return nil, ErrNoCachedConn
+		}
+		traceGetConn(req, addr)
+		call := p.getStartDialLocked(req.Context(), addr)
+		p.mu.Unlock()
+		<-call.done
+		if shouldRetryDial(call, req) {
+			continue
+		}
+		cc, err := call.res, call.err
+		if err != nil {
+			return nil, err
+		}
+		if cc.ReserveNewRequest() {
 			return cc, nil
 		}
 	}
-	if !dialOnMiss {
-		p.mu.Unlock()
-		return nil, ErrNoCachedConn
-	}
-	traceGetConn(req, addr)
-	call := p.getStartDialLocked(addr)
-	p.mu.Unlock()
-	<-call.done
-	return call.res, call.err
 }
 
 // dialCall is an in-flight Transport dial call to a host.
 type dialCall struct {
-	_    incomparable
-	p    *clientConnPool
+	_ incomparable
+	p *clientConnPool
+	// the context associated with the request
+	// that created this dialCall
+	ctx  context.Context
 	done chan struct{} // closed when done
 	res  *ClientConn   // valid after done is closed
 	err  error         // valid after done is closed
 }
 
 // requires p.mu is held.
-func (p *clientConnPool) getStartDialLocked(addr string) *dialCall {
+func (p *clientConnPool) getStartDialLocked(ctx context.Context, addr string) *dialCall {
 	if call, ok := p.dialing[addr]; ok {
 		// A dial is already in-flight. Don't start another.
 		return call
 	}
-	call := &dialCall{p: p, done: make(chan struct{})}
+	call := &dialCall{p: p, done: make(chan struct{}), ctx: ctx}
 	if p.dialing == nil {
 		p.dialing = make(map[string]*dialCall)
 	}
 	p.dialing[addr] = call
-	go call.dial(addr)
+	go call.dial(call.ctx, addr)
 	return call
 }
 
 // run in its own goroutine.
-func (c *dialCall) dial(addr string) {
+func (c *dialCall) dial(ctx context.Context, addr string) {
 	const singleUse = false // shared conn
-	c.res, c.err = c.p.t.dialClientConn(addr, singleUse)
-	close(c.done)
+	c.res, c.err = c.p.t.dialClientConn(ctx, addr, singleUse)
 
 	c.p.mu.Lock()
 	delete(c.p.dialing, addr)
@@ -141,6 +146,8 @@
 		c.p.addConnLocked(addr, c.res)
 	}
 	c.p.mu.Unlock()
+
+	close(c.done)
 }
 
 // addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't
@@ -195,6 +202,7 @@
 	if err != nil {
 		c.err = err
 	} else {
+		cc.getConnCalled = true // already called by the net/http package
 		p.addConnLocked(key, cc)
 	}
 	delete(p.addConnCalls, key)
@@ -276,3 +284,28 @@
 func (p noDialClientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) {
 	return p.getClientConn(req, addr, noDialOnMiss)
 }
+
+// shouldRetryDial reports whether the current request should
+// retry dialing after the call finished unsuccessfully, for example
+// if the dial was canceled because of a context cancellation or
+// deadline expiry.
+func shouldRetryDial(call *dialCall, req *http.Request) bool {
+	if call.err == nil {
+		// No error, no need to retry
+		return false
+	}
+	if call.ctx == req.Context() {
+		// If the call has the same context as the request, the dial
+		// should not be retried, since any cancellation will have come
+		// from this request.
+		return false
+	}
+	if !errors.Is(call.err, context.Canceled) && !errors.Is(call.err, context.DeadlineExceeded) {
+		// If the call error is not because of a context cancellation or a deadline expiry,
+		// the dial should not be retried.
+		return false
+	}
+	// Only retry if the error is a context cancellation error or deadline expiry
+	// and the context associated with the call was canceled or expired.
+	return call.ctx.Err() != nil
+}
diff --git a/vendor/golang.org/x/net/http2/errors.go b/vendor/golang.org/x/net/http2/errors.go
index 71f2c46..f2067da 100644
--- a/vendor/golang.org/x/net/http2/errors.go
+++ b/vendor/golang.org/x/net/http2/errors.go
@@ -53,6 +53,13 @@
 	return fmt.Sprintf("unknown error code 0x%x", uint32(e))
 }
 
+func (e ErrCode) stringToken() string {
+	if s, ok := errCodeName[e]; ok {
+		return s
+	}
+	return fmt.Sprintf("ERR_UNKNOWN_%d", uint32(e))
+}
+
 // ConnectionError is an error that results in the termination of the
 // entire connection.
 type ConnectionError ErrCode
@@ -67,6 +74,11 @@
 	Cause    error // optional additional detail
 }
 
+// errFromPeer is a sentinel error value for StreamError.Cause to
+// indicate that the StreamError was sent from the peer over the wire
+// and wasn't locally generated in the Transport.
+var errFromPeer = errors.New("received from peer")
+
 func streamError(id uint32, code ErrCode) StreamError {
 	return StreamError{StreamID: id, Code: code}
 }
@@ -124,7 +136,7 @@
 type headerFieldValueError string
 
 func (e headerFieldValueError) Error() string {
-	return fmt.Sprintf("invalid header field value %q", string(e))
+	return fmt.Sprintf("invalid header field value for %q", string(e))
 }
 
 var (
diff --git a/vendor/golang.org/x/net/http2/flow.go b/vendor/golang.org/x/net/http2/flow.go
index b51f0e0..b7dbd18 100644
--- a/vendor/golang.org/x/net/http2/flow.go
+++ b/vendor/golang.org/x/net/http2/flow.go
@@ -6,23 +6,91 @@
 
 package http2
 
-// flow is the flow control window's size.
-type flow struct {
+// inflowMinRefresh is the minimum number of bytes we'll send for a
+// flow control window update.
+const inflowMinRefresh = 4 << 10
+
+// inflow accounts for an inbound flow control window.
+// It tracks both the latest window sent to the peer (used for enforcement)
+// and the accumulated unsent window.
+type inflow struct {
+	avail  int32
+	unsent int32
+}
+
+// init sets the initial window.
+func (f *inflow) init(n int32) {
+	f.avail = n
+}
+
+// add adds n bytes to the window, with a maximum window size of max,
+// indicating that the peer can now send us more data.
+// For example, the user read from a {Request,Response} body and consumed
+// some of the buffered data, so the peer can now send more.
+// It returns the number of bytes to send in a WINDOW_UPDATE frame to the peer.
+// Window updates are accumulated and sent when the unsent capacity
+// is at least inflowMinRefresh or will at least double the peer's available window.
+func (f *inflow) add(n int) (connAdd int32) {
+	if n < 0 {
+		panic("negative update")
+	}
+	unsent := int64(f.unsent) + int64(n)
+	// "A sender MUST NOT allow a flow-control window to exceed 2^31-1 octets."
+	// RFC 7540 Section 6.9.1.
+	const maxWindow = 1<<31 - 1
+	if unsent+int64(f.avail) > maxWindow {
+		panic("flow control update exceeds maximum window size")
+	}
+	f.unsent = int32(unsent)
+	if f.unsent < inflowMinRefresh && f.unsent < f.avail {
+		// If there aren't at least inflowMinRefresh bytes of window to send,
+		// and this update won't at least double the window, buffer the update for later.
+		return 0
+	}
+	f.avail += f.unsent
+	f.unsent = 0
+	return int32(unsent)
+}
+
+// take attempts to take n bytes from the peer's flow control window.
+// It reports whether the window has available capacity.
+func (f *inflow) take(n uint32) bool {
+	if n > uint32(f.avail) {
+		return false
+	}
+	f.avail -= int32(n)
+	return true
+}
+
+// takeInflows attempts to take n bytes from two inflows,
+// typically connection-level and stream-level flows.
+// It reports whether both windows have available capacity.
+func takeInflows(f1, f2 *inflow, n uint32) bool {
+	if n > uint32(f1.avail) || n > uint32(f2.avail) {
+		return false
+	}
+	f1.avail -= int32(n)
+	f2.avail -= int32(n)
+	return true
+}
+
+// outflow is the outbound flow control window's size.
+type outflow struct {
 	_ incomparable
 
 	// n is the number of DATA bytes we're allowed to send.
-	// A flow is kept both on a conn and a per-stream.
+	// An outflow is kept both on a conn and a per-stream.
 	n int32
 
-	// conn points to the shared connection-level flow that is
-	// shared by all streams on that conn. It is nil for the flow
+	// conn points to the shared connection-level outflow that is
+	// shared by all streams on that conn. It is nil for the outflow
 	// that's on the conn directly.
-	conn *flow
+	conn *outflow
 }
 
-func (f *flow) setConnFlow(cf *flow) { f.conn = cf }
+func (f *outflow) setConnFlow(cf *outflow) { f.conn = cf }
 
-func (f *flow) available() int32 {
+func (f *outflow) available() int32 {
 	n := f.n
 	if f.conn != nil && f.conn.n < n {
 		n = f.conn.n
@@ -30,7 +98,7 @@
 	return n
 }
 
-func (f *flow) take(n int32) {
+func (f *outflow) take(n int32) {
 	if n > f.available() {
 		panic("internal error: took too much")
 	}
@@ -42,7 +110,7 @@
 
 // add adds n bytes (positive or negative) to the flow control window.
 // It returns false if the sum would exceed 2^31-1.
-func (f *flow) add(n int32) bool {
+func (f *outflow) add(n int32) bool {
 	sum := f.n + n
 	if (sum > n) == (f.n > 0) {
 		f.n = sum
diff --git a/vendor/golang.org/x/net/http2/frame.go b/vendor/golang.org/x/net/http2/frame.go
index 514c126..c1f6b90 100644
--- a/vendor/golang.org/x/net/http2/frame.go
+++ b/vendor/golang.org/x/net/http2/frame.go
@@ -23,7 +23,7 @@
 var padZeros = make([]byte, 255) // zeros for padding
 
 // A FrameType is a registered frame type as defined in
-// http://http2.github.io/http2-spec/#rfc.section.11.2
+// https://httpwg.org/specs/rfc7540.html#rfc.section.11.2
 type FrameType uint8
 
 const (
@@ -122,7 +122,7 @@
 // a frameParser parses a frame given its FrameHeader and payload
 // bytes. The length of payload will always equal fh.Length (which
 // might be 0).
-type frameParser func(fc *frameCache, fh FrameHeader, payload []byte) (Frame, error)
+type frameParser func(fc *frameCache, fh FrameHeader, countError func(string), payload []byte) (Frame, error)
 
 var frameParsers = map[FrameType]frameParser{
 	FrameData:         parseDataFrame,
@@ -146,7 +146,7 @@
 
 // A FrameHeader is the 9 byte header of all HTTP/2 frames.
 //
-// See http://http2.github.io/http2-spec/#FrameHeader
+// See https://httpwg.org/specs/rfc7540.html#FrameHeader
 type FrameHeader struct {
 	valid bool // caller can access []byte fields in the Frame
 
@@ -267,6 +267,11 @@
 	lastFrame Frame
 	errDetail error
 
+	// countError is a non-nil func that's called on a frame parse
+	// error with some unique error path token. It's initialized
+	// from Transport.CountError or Server.CountError.
+	countError func(errToken string)
+
 	// lastHeaderStream is non-zero if the last frame was an
 	// unfinished HEADERS/CONTINUATION.
 	lastHeaderStream uint32
@@ -426,6 +431,7 @@
 	fr := &Framer{
 		w:                 w,
 		r:                 r,
+		countError:        func(string) {},
 		logReads:          logFrameReads,
 		logWrites:         logFrameWrites,
 		debugReadLoggerf:  log.Printf,
@@ -500,7 +506,7 @@
 	if _, err := io.ReadFull(fr.r, payload); err != nil {
 		return nil, err
 	}
-	f, err := typeFrameParser(fh.Type)(fr.frameCache, fh, payload)
+	f, err := typeFrameParser(fh.Type)(fr.frameCache, fh, fr.countError, payload)
 	if err != nil {
 		if ce, ok := err.(connError); ok {
 			return nil, fr.connError(ce.Code, ce.Reason)
@@ -569,7 +575,7 @@
 
 // A DataFrame conveys arbitrary, variable-length sequences of octets
 // associated with a stream.
-// See http://http2.github.io/http2-spec/#rfc.section.6.1
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.1
 type DataFrame struct {
 	FrameHeader
 	data []byte
@@ -588,13 +594,14 @@
 	return f.data
 }
 
-func parseDataFrame(fc *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+func parseDataFrame(fc *frameCache, fh FrameHeader, countError func(string), payload []byte) (Frame, error) {
 	if fh.StreamID == 0 {
 		// DATA frames MUST be associated with a stream. If a
 		// DATA frame is received whose stream identifier
 		// field is 0x0, the recipient MUST respond with a
 		// connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
+		countError("frame_data_stream_0")
 		return nil, connError{ErrCodeProtocol, "DATA frame with stream ID 0"}
 	}
 	f := fc.getDataFrame()
@@ -605,6 +612,7 @@
 		var err error
 		payload, padSize, err = readByte(payload)
 		if err != nil {
+			countError("frame_data_pad_byte_short")
 			return nil, err
 		}
 	}
@@ -613,6 +621,7 @@
 		// length of the frame payload, the recipient MUST
 		// treat this as a connection error.
 		// Filed: https://github.com/http2/http2-spec/issues/610
+		countError("frame_data_pad_too_big")
 		return nil, connError{ErrCodeProtocol, "pad size larger than data payload"}
 	}
 	f.data = payload[:len(payload)-int(padSize)]
@@ -653,6 +662,15 @@
 // It is the caller's responsibility not to violate the maximum frame size
 // and to not call other Write methods concurrently.
 func (f *Framer) WriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error {
+	if err := f.startWriteDataPadded(streamID, endStream, data, pad); err != nil {
+		return err
+	}
+	return f.endWrite()
+}
+
+// startWriteDataPadded is WriteDataPadded, but only writes the frame to the Framer's internal buffer.
+// The caller should call endWrite to flush the frame to the underlying writer.
+func (f *Framer) startWriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error {
 	if !validStreamID(streamID) && !f.AllowIllegalWrites {
 		return errStreamID
 	}
@@ -682,20 +700,20 @@
 	}
 	f.wbuf = append(f.wbuf, data...)
 	f.wbuf = append(f.wbuf, pad...)
-	return f.endWrite()
+	return nil
 }
 
 // A SettingsFrame conveys configuration parameters that affect how
 // endpoints communicate, such as preferences and constraints on peer
 // behavior.
 //
-// See http://http2.github.io/http2-spec/#SETTINGS
+// See https://httpwg.org/specs/rfc7540.html#SETTINGS
 type SettingsFrame struct {
 	FrameHeader
 	p []byte
 }
 
-func parseSettingsFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseSettingsFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	if fh.Flags.Has(FlagSettingsAck) && fh.Length > 0 {
 		// When this (ACK 0x1) bit is set, the payload of the
 		// SETTINGS frame MUST be empty. Receipt of a
@@ -703,6 +721,7 @@
 		// field value other than 0 MUST be treated as a
 		// connection error (Section 5.4.1) of type
 		// FRAME_SIZE_ERROR.
+		countError("frame_settings_ack_with_length")
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	if fh.StreamID != 0 {
@@ -713,14 +732,17 @@
 		// field is anything other than 0x0, the endpoint MUST
 		// respond with a connection error (Section 5.4.1) of
 		// type PROTOCOL_ERROR.
+		countError("frame_settings_has_stream")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	if len(p)%6 != 0 {
+		countError("frame_settings_mod_6")
 		// Expecting even number of 6 byte settings.
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	f := &SettingsFrame{FrameHeader: fh, p: p}
 	if v, ok := f.Value(SettingInitialWindowSize); ok && v > (1<<31)-1 {
+		countError("frame_settings_window_size_too_big")
 		// Values above the maximum flow control window size of 2^31 - 1 MUST
 		// be treated as a connection error (Section 5.4.1) of type
 		// FLOW_CONTROL_ERROR.
@@ -824,7 +846,7 @@
 // A PingFrame is a mechanism for measuring a minimal round trip time
 // from the sender, as well as determining whether an idle connection
 // is still functional.
-// See http://http2.github.io/http2-spec/#rfc.section.6.7
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.7
 type PingFrame struct {
 	FrameHeader
 	Data [8]byte
@@ -832,11 +854,13 @@
 
 func (f *PingFrame) IsAck() bool { return f.Flags.Has(FlagPingAck) }
 
-func parsePingFrame(_ *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+func parsePingFrame(_ *frameCache, fh FrameHeader, countError func(string), payload []byte) (Frame, error) {
 	if len(payload) != 8 {
+		countError("frame_ping_length")
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	if fh.StreamID != 0 {
+		countError("frame_ping_has_stream")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	f := &PingFrame{FrameHeader: fh}
@@ -855,7 +879,7 @@
 }
 
 // A GoAwayFrame informs the remote peer to stop creating streams on this connection.
-// See http://http2.github.io/http2-spec/#rfc.section.6.8
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.8
 type GoAwayFrame struct {
 	FrameHeader
 	LastStreamID uint32
@@ -872,11 +896,13 @@
 	return f.debugData
 }
 
-func parseGoAwayFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseGoAwayFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	if fh.StreamID != 0 {
+		countError("frame_goaway_has_stream")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	if len(p) < 8 {
+		countError("frame_goaway_short")
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	return &GoAwayFrame{
@@ -912,19 +938,20 @@
 	return f.p
 }
 
-func parseUnknownFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseUnknownFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	return &UnknownFrame{fh, p}, nil
 }
 
 // A WindowUpdateFrame is used to implement flow control.
-// See http://http2.github.io/http2-spec/#rfc.section.6.9
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.9
 type WindowUpdateFrame struct {
 	FrameHeader
 	Increment uint32 // never read with high bit set
 }
 
-func parseWindowUpdateFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseWindowUpdateFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	if len(p) != 4 {
+		countError("frame_windowupdate_bad_len")
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	inc := binary.BigEndian.Uint32(p[:4]) & 0x7fffffff // mask off high reserved bit
@@ -936,8 +963,10 @@
 		// control window MUST be treated as a connection
 		// error (Section 5.4.1).
 		if fh.StreamID == 0 {
+			countError("frame_windowupdate_zero_inc_conn")
 			return nil, ConnectionError(ErrCodeProtocol)
 		}
+		countError("frame_windowupdate_zero_inc_stream")
 		return nil, streamError(fh.StreamID, ErrCodeProtocol)
 	}
 	return &WindowUpdateFrame{
@@ -988,7 +1017,7 @@
 	return f.FrameHeader.Flags.Has(FlagHeadersPriority)
 }
 
-func parseHeadersFrame(_ *frameCache, fh FrameHeader, p []byte) (_ Frame, err error) {
+func parseHeadersFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (_ Frame, err error) {
 	hf := &HeadersFrame{
 		FrameHeader: fh,
 	}
@@ -997,11 +1026,13 @@
 		// is received whose stream identifier field is 0x0, the recipient MUST
 		// respond with a connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
+		countError("frame_headers_zero_stream")
 		return nil, connError{ErrCodeProtocol, "HEADERS frame with stream ID 0"}
 	}
 	var padLength uint8
 	if fh.Flags.Has(FlagHeadersPadded) {
 		if p, padLength, err = readByte(p); err != nil {
+			countError("frame_headers_pad_short")
 			return
 		}
 	}
@@ -1009,16 +1040,19 @@
 		var v uint32
 		p, v, err = readUint32(p)
 		if err != nil {
+			countError("frame_headers_prio_short")
 			return nil, err
 		}
 		hf.Priority.StreamDep = v & 0x7fffffff
 		hf.Priority.Exclusive = (v != hf.Priority.StreamDep) // high bit was set
 		p, hf.Priority.Weight, err = readByte(p)
 		if err != nil {
+			countError("frame_headers_prio_weight_short")
 			return nil, err
 		}
 	}
-	if len(p)-int(padLength) <= 0 {
+	if len(p)-int(padLength) < 0 {
+		countError("frame_headers_pad_too_big")
 		return nil, streamError(fh.StreamID, ErrCodeProtocol)
 	}
 	hf.headerFragBuf = p[:len(p)-int(padLength)]
@@ -1098,7 +1132,7 @@
 }
 
 // A PriorityFrame specifies the sender-advised priority of a stream.
-// See http://http2.github.io/http2-spec/#rfc.section.6.3
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.3
 type PriorityFrame struct {
 	FrameHeader
 	PriorityParam
@@ -1125,11 +1159,13 @@
 	return p == PriorityParam{}
 }
 
-func parsePriorityFrame(_ *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+func parsePriorityFrame(_ *frameCache, fh FrameHeader, countError func(string), payload []byte) (Frame, error) {
 	if fh.StreamID == 0 {
+		countError("frame_priority_zero_stream")
 		return nil, connError{ErrCodeProtocol, "PRIORITY frame with stream ID 0"}
 	}
 	if len(payload) != 5 {
+		countError("frame_priority_bad_length")
 		return nil, connError{ErrCodeFrameSize, fmt.Sprintf("PRIORITY frame payload size was %d; want 5", len(payload))}
 	}
 	v := binary.BigEndian.Uint32(payload[:4])
@@ -1166,17 +1202,19 @@
 }
 
 // A RSTStreamFrame allows for abnormal termination of a stream.
-// See http://http2.github.io/http2-spec/#rfc.section.6.4
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.4
 type RSTStreamFrame struct {
 	FrameHeader
 	ErrCode ErrCode
 }
 
-func parseRSTStreamFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseRSTStreamFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	if len(p) != 4 {
+		countError("frame_rststream_bad_len")
 		return nil, ConnectionError(ErrCodeFrameSize)
 	}
 	if fh.StreamID == 0 {
+		countError("frame_rststream_zero_stream")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	return &RSTStreamFrame{fh, ErrCode(binary.BigEndian.Uint32(p[:4]))}, nil
@@ -1196,14 +1234,15 @@
 }
 
 // A ContinuationFrame is used to continue a sequence of header block fragments.
-// See http://http2.github.io/http2-spec/#rfc.section.6.10
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.10
 type ContinuationFrame struct {
 	FrameHeader
 	headerFragBuf []byte
 }
 
-func parseContinuationFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+func parseContinuationFrame(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (Frame, error) {
 	if fh.StreamID == 0 {
+		countError("frame_continuation_zero_stream")
 		return nil, connError{ErrCodeProtocol, "CONTINUATION frame with stream ID 0"}
 	}
 	return &ContinuationFrame{fh, p}, nil
@@ -1236,7 +1275,7 @@
 }
 
 // A PushPromiseFrame is used to initiate a server stream.
-// See http://http2.github.io/http2-spec/#rfc.section.6.6
+// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.6
 type PushPromiseFrame struct {
 	FrameHeader
 	PromiseID     uint32
@@ -1252,7 +1291,7 @@
 	return f.FrameHeader.Flags.Has(FlagPushPromiseEndHeaders)
 }
 
-func parsePushPromise(_ *frameCache, fh FrameHeader, p []byte) (_ Frame, err error) {
+func parsePushPromise(_ *frameCache, fh FrameHeader, countError func(string), p []byte) (_ Frame, err error) {
 	pp := &PushPromiseFrame{
 		FrameHeader: fh,
 	}
@@ -1263,6 +1302,7 @@
 		// with. If the stream identifier field specifies the value
 		// 0x0, a recipient MUST respond with a connection error
 		// (Section 5.4.1) of type PROTOCOL_ERROR.
+		countError("frame_pushpromise_zero_stream")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	// The PUSH_PROMISE frame includes optional padding.
@@ -1270,18 +1310,21 @@
 	var padLength uint8
 	if fh.Flags.Has(FlagPushPromisePadded) {
 		if p, padLength, err = readByte(p); err != nil {
+			countError("frame_pushpromise_pad_short")
 			return
 		}
 	}
 
 	p, pp.PromiseID, err = readUint32(p)
 	if err != nil {
+		countError("frame_pushpromise_promiseid_short")
 		return
 	}
 	pp.PromiseID = pp.PromiseID & (1<<31 - 1)
 
 	if int(padLength) > len(p) {
 		// like the DATA frame, error out if padding is longer than the body.
+		countError("frame_pushpromise_pad_too_big")
 		return nil, ConnectionError(ErrCodeProtocol)
 	}
 	pp.headerFragBuf = p[:len(p)-int(padLength)]
@@ -1498,7 +1541,8 @@
 			fr.debugReadLoggerf("http2: decoded hpack field %+v", hf)
 		}
 		if !httpguts.ValidHeaderFieldValue(hf.Value) {
-			invalid = headerFieldValueError(hf.Value)
+			// Don't include the value in the error, because it may be sensitive.
+			invalid = headerFieldValueError(hf.Name)
 		}
 		isPseudo := strings.HasPrefix(hf.Name, ":")
 		if isPseudo {
diff --git a/vendor/golang.org/x/net/http2/go115.go b/vendor/golang.org/x/net/http2/go115.go
new file mode 100644
index 0000000..908af1a
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/go115.go
@@ -0,0 +1,27 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.15
+// +build go1.15
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
+// connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	dialer := &tls.Dialer{
+		Config: cfg,
+	}
+	cn, err := dialer.DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, err
+	}
+	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
+	return tlsCn, nil
+}
diff --git a/vendor/golang.org/x/net/http2/go118.go b/vendor/golang.org/x/net/http2/go118.go
new file mode 100644
index 0000000..aca4b2b
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/go118.go
@@ -0,0 +1,17 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.18
+// +build go1.18
+
+package http2
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+func tlsUnderlyingConn(tc *tls.Conn) net.Conn {
+	return tc.NetConn()
+}
diff --git a/vendor/golang.org/x/net/http2/headermap.go b/vendor/golang.org/x/net/http2/headermap.go
index c3ff3fa..149b3dd 100644
--- a/vendor/golang.org/x/net/http2/headermap.go
+++ b/vendor/golang.org/x/net/http2/headermap.go
@@ -6,7 +6,6 @@
 
 import (
 	"net/http"
-	"strings"
 	"sync"
 )
 
@@ -28,7 +27,14 @@
 		"accept-language",
 		"accept-ranges",
 		"age",
+		"access-control-allow-credentials",
+		"access-control-allow-headers",
+		"access-control-allow-methods",
 		"access-control-allow-origin",
+		"access-control-expose-headers",
+		"access-control-max-age",
+		"access-control-request-headers",
+		"access-control-request-method",
 		"allow",
 		"authorization",
 		"cache-control",
@@ -54,6 +60,7 @@
 		"link",
 		"location",
 		"max-forwards",
+		"origin",
 		"proxy-authenticate",
 		"proxy-authorization",
 		"range",
@@ -69,6 +76,8 @@
 		"vary",
 		"via",
 		"www-authenticate",
+		"x-forwarded-for",
+		"x-forwarded-proto",
 	}
 	commonLowerHeader = make(map[string]string, len(common))
 	commonCanonHeader = make(map[string]string, len(common))
@@ -79,10 +88,18 @@
 	}
 }
 
-func lowerHeader(v string) string {
+func lowerHeader(v string) (lower string, ascii bool) {
 	buildCommonHeaderMapsOnce()
 	if s, ok := commonLowerHeader[v]; ok {
+		return s, true
+	}
+	return asciiToLower(v)
+}
+
+func canonicalHeader(v string) string {
+	buildCommonHeaderMapsOnce()
+	if s, ok := commonCanonHeader[v]; ok {
 		return s
 	}
-	return strings.ToLower(v)
+	return http.CanonicalHeaderKey(v)
 }
diff --git a/vendor/golang.org/x/net/http2/hpack/encode.go b/vendor/golang.org/x/net/http2/hpack/encode.go
index 97f1783..46219da 100644
--- a/vendor/golang.org/x/net/http2/hpack/encode.go
+++ b/vendor/golang.org/x/net/http2/hpack/encode.go
@@ -116,6 +116,11 @@
 	e.dynTab.setMaxSize(v)
 }
 
+// MaxDynamicTableSize returns the current dynamic header table size.
+func (e *Encoder) MaxDynamicTableSize() (v uint32) {
+	return e.dynTab.maxSize
+}
+
 // SetMaxDynamicTableSizeLimit changes the maximum value that can be
 // specified in SetMaxDynamicTableSize to v. By default, it is set to
 // 4096, which is the same size of the default dynamic header table
@@ -191,7 +196,7 @@
 // bit prefix, to dst and returns the extended buffer.
 //
 // See
-// http://http2.github.io/http2-spec/compression.html#integer.representation
+// https://httpwg.org/specs/rfc7541.html#integer.representation
 func appendVarInt(dst []byte, n byte, i uint64) []byte {
 	k := uint64((1 << n) - 1)
 	if i < k {
diff --git a/vendor/golang.org/x/net/http2/hpack/hpack.go b/vendor/golang.org/x/net/http2/hpack/hpack.go
index 85f18a2..7a1d976 100644
--- a/vendor/golang.org/x/net/http2/hpack/hpack.go
+++ b/vendor/golang.org/x/net/http2/hpack/hpack.go
@@ -59,7 +59,7 @@
 
 // Size returns the size of an entry per RFC 7541 section 4.1.
 func (hf HeaderField) Size() uint32 {
-	// http://http2.github.io/http2-spec/compression.html#rfc.section.4.1
+	// https://httpwg.org/specs/rfc7541.html#rfc.section.4.1
 	// "The size of the dynamic table is the sum of the size of
 	// its entries. The size of an entry is the sum of its name's
 	// length in octets (as defined in Section 5.2), its value's
@@ -158,7 +158,7 @@
 }
 
 type dynamicTable struct {
-	// http://http2.github.io/http2-spec/compression.html#rfc.section.2.3.2
+	// https://httpwg.org/specs/rfc7541.html#rfc.section.2.3.2
 	table          headerFieldTable
 	size           uint32 // in bytes
 	maxSize        uint32 // current maxSize
@@ -211,7 +211,7 @@
 	return dt.ents[dt.len()-(int(i)-staticTable.len())], true
 }
 
-// Decode decodes an entire block.
+// DecodeFull decodes an entire block.
 //
 // TODO: remove this method and make it incremental later? This is
 // easier for debugging now.
@@ -307,27 +307,27 @@
 	case b&128 != 0:
 		// Indexed representation.
 		// High bit set?
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.1
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.1
 		return d.parseFieldIndexed()
 	case b&192 == 64:
 		// 6.2.1 Literal Header Field with Incremental Indexing
 		// 0b10xxxxxx: top two bits are 10
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.1
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.1
 		return d.parseFieldLiteral(6, indexedTrue)
 	case b&240 == 0:
 		// 6.2.2 Literal Header Field without Indexing
 		// 0b0000xxxx: top four bits are 0000
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.2
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.2
 		return d.parseFieldLiteral(4, indexedFalse)
 	case b&240 == 16:
 		// 6.2.3 Literal Header Field never Indexed
 		// 0b0001xxxx: top four bits are 0001
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.3
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.3
 		return d.parseFieldLiteral(4, indexedNever)
 	case b&224 == 32:
 		// 6.3 Dynamic Table Size Update
 		// Top three bits are '001'.
-		// http://http2.github.io/http2-spec/compression.html#rfc.section.6.3
+		// https://httpwg.org/specs/rfc7541.html#rfc.section.6.3
 		return d.parseDynamicTableSizeUpdate()
 	}
 
@@ -359,6 +359,7 @@
 
 	var hf HeaderField
 	wantStr := d.emitEnabled || it.indexed()
+	var undecodedName undecodedString
 	if nameIdx > 0 {
 		ihf, ok := d.at(nameIdx)
 		if !ok {
@@ -366,15 +367,27 @@
 		}
 		hf.Name = ihf.Name
 	} else {
-		hf.Name, buf, err = d.readString(buf, wantStr)
+		undecodedName, buf, err = d.readString(buf)
 		if err != nil {
 			return err
 		}
 	}
-	hf.Value, buf, err = d.readString(buf, wantStr)
+	undecodedValue, buf, err := d.readString(buf)
 	if err != nil {
 		return err
 	}
+	if wantStr {
+		if nameIdx <= 0 {
+			hf.Name, err = d.decodeString(undecodedName)
+			if err != nil {
+				return err
+			}
+		}
+		hf.Value, err = d.decodeString(undecodedValue)
+		if err != nil {
+			return err
+		}
+	}
 	d.buf = buf
 	if it.indexed() {
 		d.dynTab.add(hf)
@@ -420,7 +433,7 @@
 
 // readVarInt reads an unsigned variable length integer off the
 // beginning of p. n is the parameter as described in
-// http://http2.github.io/http2-spec/compression.html#rfc.section.5.1.
+// https://httpwg.org/specs/rfc7541.html#rfc.section.5.1.
 //
 // n must always be between 1 and 8.
 //
@@ -459,46 +472,52 @@
 	return 0, origP, errNeedMore
 }
 
-// readString decodes an hpack string from p.
+// readString reads an hpack string from p.
 //
-// wantStr is whether s will be used. If false, decompression and
-// []byte->string garbage are skipped if s will be ignored
-// anyway. This does mean that huffman decoding errors for non-indexed
-// strings past the MAX_HEADER_LIST_SIZE are ignored, but the server
-// is returning an error anyway, and because they're not indexed, the error
-// won't affect the decoding state.
-func (d *Decoder) readString(p []byte, wantStr bool) (s string, remain []byte, err error) {
+// It returns a reference to the encoded string data to permit deferring decode costs
+// until after the caller verifies all data is present.
+func (d *Decoder) readString(p []byte) (u undecodedString, remain []byte, err error) {
 	if len(p) == 0 {
-		return "", p, errNeedMore
+		return u, p, errNeedMore
 	}
 	isHuff := p[0]&128 != 0
 	strLen, p, err := readVarInt(7, p)
 	if err != nil {
-		return "", p, err
+		return u, p, err
 	}
 	if d.maxStrLen != 0 && strLen > uint64(d.maxStrLen) {
-		return "", nil, ErrStringLength
+		// Returning an error here means Huffman decoding errors
+		// for non-indexed strings past the maximum string length
+		// are ignored, but the server is returning an error anyway
+		// and because the string is not indexed the error will not
+		// affect the decoding state.
+		return u, nil, ErrStringLength
 	}
 	if uint64(len(p)) < strLen {
-		return "", p, errNeedMore
+		return u, p, errNeedMore
 	}
-	if !isHuff {
-		if wantStr {
-			s = string(p[:strLen])
-		}
-		return s, p[strLen:], nil
-	}
+	u.isHuff = isHuff
+	u.b = p[:strLen]
+	return u, p[strLen:], nil
+}
 
-	if wantStr {
-		buf := bufPool.Get().(*bytes.Buffer)
-		buf.Reset() // don't trust others
-		defer bufPool.Put(buf)
-		if err := huffmanDecode(buf, d.maxStrLen, p[:strLen]); err != nil {
-			buf.Reset()
-			return "", nil, err
-		}
-		s = buf.String()
-		buf.Reset() // be nice to GC
+type undecodedString struct {
+	isHuff bool
+	b      []byte
+}
+
+func (d *Decoder) decodeString(u undecodedString) (string, error) {
+	if !u.isHuff {
+		return string(u.b), nil
 	}
-	return s, p[strLen:], nil
+	buf := bufPool.Get().(*bytes.Buffer)
+	buf.Reset() // don't trust others
+	var s string
+	err := huffmanDecode(buf, d.maxStrLen, u.b)
+	if err == nil {
+		s = buf.String()
+	}
+	buf.Reset() // be nice to GC
+	bufPool.Put(buf)
+	return s, err
 }
diff --git a/vendor/golang.org/x/net/http2/hpack/huffman.go b/vendor/golang.org/x/net/http2/hpack/huffman.go
index a1ab2f0..20d083a 100644
--- a/vendor/golang.org/x/net/http2/hpack/huffman.go
+++ b/vendor/golang.org/x/net/http2/hpack/huffman.go
@@ -140,50 +140,79 @@
 		panic("unexpected size")
 	}
 	lazyRootHuffmanNode = newInternalNode()
-	for i, code := range huffmanCodes {
-		addDecoderNode(byte(i), code, huffmanCodeLen[i])
-	}
-}
+	// allocate a leaf node for each of the 256 symbols
+	leaves := new([256]node)
 
-func addDecoderNode(sym byte, code uint32, codeLen uint8) {
-	cur := lazyRootHuffmanNode
-	for codeLen > 8 {
-		codeLen -= 8
-		i := uint8(code >> codeLen)
-		if cur.children[i] == nil {
-			cur.children[i] = newInternalNode()
+	for sym, code := range huffmanCodes {
+		codeLen := huffmanCodeLen[sym]
+
+		cur := lazyRootHuffmanNode
+		for codeLen > 8 {
+			codeLen -= 8
+			i := uint8(code >> codeLen)
+			if cur.children[i] == nil {
+				cur.children[i] = newInternalNode()
+			}
+			cur = cur.children[i]
 		}
-		cur = cur.children[i]
-	}
-	shift := 8 - codeLen
-	start, end := int(uint8(code<<shift)), int(1<<shift)
-	for i := start; i < start+end; i++ {
-		cur.children[i] = &node{sym: sym, codeLen: codeLen}
+		shift := 8 - codeLen
+		start, end := int(uint8(code<<shift)), int(1<<shift)
+
+		leaves[sym].sym = byte(sym)
+		leaves[sym].codeLen = codeLen
+		for i := start; i < start+end; i++ {
+			cur.children[i] = &leaves[sym]
+		}
 	}
 }
 
 // AppendHuffmanString appends s, as encoded in Huffman codes, to dst
 // and returns the extended buffer.
 func AppendHuffmanString(dst []byte, s string) []byte {
-	rembits := uint8(8)
-
+	// This relies on the maximum huffman code length being 30 (See tables.go huffmanCodeLen array)
+	// So if a uint64 buffer has less than 32 valid bits can always accommodate another huffmanCode.
+	var (
+		x uint64 // buffer
+		n uint   // number valid of bits present in x
+	)
 	for i := 0; i < len(s); i++ {
-		if rembits == 8 {
-			dst = append(dst, 0)
+		c := s[i]
+		n += uint(huffmanCodeLen[c])
+		x <<= huffmanCodeLen[c] % 64
+		x |= uint64(huffmanCodes[c])
+		if n >= 32 {
+			n %= 32             // Normally would be -= 32 but %= 32 informs compiler 0 <= n <= 31 for upcoming shift
+			y := uint32(x >> n) // Compiler doesn't combine memory writes if y isn't uint32
+			dst = append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
 		}
-		dst, rembits = appendByteToHuffmanCode(dst, rembits, s[i])
 	}
-
-	if rembits < 8 {
-		// special EOS symbol
-		code := uint32(0x3fffffff)
-		nbits := uint8(30)
-
-		t := uint8(code >> (nbits - rembits))
-		dst[len(dst)-1] |= t
+	// Add padding bits if necessary
+	if over := n % 8; over > 0 {
+		const (
+			eosCode    = 0x3fffffff
+			eosNBits   = 30
+			eosPadByte = eosCode >> (eosNBits - 8)
+		)
+		pad := 8 - over
+		x = (x << pad) | (eosPadByte >> over)
+		n += pad // 8 now divides into n exactly
 	}
-
-	return dst
+	// n in (0, 8, 16, 24, 32)
+	switch n / 8 {
+	case 0:
+		return dst
+	case 1:
+		return append(dst, byte(x))
+	case 2:
+		y := uint16(x)
+		return append(dst, byte(y>>8), byte(y))
+	case 3:
+		y := uint16(x >> 8)
+		return append(dst, byte(y>>8), byte(y), byte(x))
+	}
+	//	case 4:
+	y := uint32(x)
+	return append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
 }
 
 // HuffmanEncodeLength returns the number of bytes required to encode
@@ -195,35 +224,3 @@
 	}
 	return (n + 7) / 8
 }
-
-// appendByteToHuffmanCode appends Huffman code for c to dst and
-// returns the extended buffer and the remaining bits in the last
-// element. The appending is not byte aligned and the remaining bits
-// in the last element of dst is given in rembits.
-func appendByteToHuffmanCode(dst []byte, rembits uint8, c byte) ([]byte, uint8) {
-	code := huffmanCodes[c]
-	nbits := huffmanCodeLen[c]
-
-	for {
-		if rembits > nbits {
-			t := uint8(code << (rembits - nbits))
-			dst[len(dst)-1] |= t
-			rembits -= nbits
-			break
-		}
-
-		t := uint8(code >> (nbits - rembits))
-		dst[len(dst)-1] |= t
-
-		nbits -= rembits
-		rembits = 8
-
-		if nbits == 0 {
-			break
-		}
-
-		dst = append(dst, 0)
-	}
-
-	return dst, rembits
-}
diff --git a/vendor/golang.org/x/net/http2/hpack/static_table.go b/vendor/golang.org/x/net/http2/hpack/static_table.go
new file mode 100644
index 0000000..754a1eb
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/hpack/static_table.go
@@ -0,0 +1,188 @@
+// go generate gen.go
+// Code generated by the command above; DO NOT EDIT.
+
+package hpack
+
+var staticTable = &headerFieldTable{
+	evictCount: 0,
+	byName: map[string]uint64{
+		":authority":                  1,
+		":method":                     3,
+		":path":                       5,
+		":scheme":                     7,
+		":status":                     14,
+		"accept-charset":              15,
+		"accept-encoding":             16,
+		"accept-language":             17,
+		"accept-ranges":               18,
+		"accept":                      19,
+		"access-control-allow-origin": 20,
+		"age":                         21,
+		"allow":                       22,
+		"authorization":               23,
+		"cache-control":               24,
+		"content-disposition":         25,
+		"content-encoding":            26,
+		"content-language":            27,
+		"content-length":              28,
+		"content-location":            29,
+		"content-range":               30,
+		"content-type":                31,
+		"cookie":                      32,
+		"date":                        33,
+		"etag":                        34,
+		"expect":                      35,
+		"expires":                     36,
+		"from":                        37,
+		"host":                        38,
+		"if-match":                    39,
+		"if-modified-since":           40,
+		"if-none-match":               41,
+		"if-range":                    42,
+		"if-unmodified-since":         43,
+		"last-modified":               44,
+		"link":                        45,
+		"location":                    46,
+		"max-forwards":                47,
+		"proxy-authenticate":          48,
+		"proxy-authorization":         49,
+		"range":                       50,
+		"referer":                     51,
+		"refresh":                     52,
+		"retry-after":                 53,
+		"server":                      54,
+		"set-cookie":                  55,
+		"strict-transport-security":   56,
+		"transfer-encoding":           57,
+		"user-agent":                  58,
+		"vary":                        59,
+		"via":                         60,
+		"www-authenticate":            61,
+	},
+	byNameValue: map[pairNameValue]uint64{
+		{name: ":authority", value: ""}:                   1,
+		{name: ":method", value: "GET"}:                   2,
+		{name: ":method", value: "POST"}:                  3,
+		{name: ":path", value: "/"}:                       4,
+		{name: ":path", value: "/index.html"}:             5,
+		{name: ":scheme", value: "http"}:                  6,
+		{name: ":scheme", value: "https"}:                 7,
+		{name: ":status", value: "200"}:                   8,
+		{name: ":status", value: "204"}:                   9,
+		{name: ":status", value: "206"}:                   10,
+		{name: ":status", value: "304"}:                   11,
+		{name: ":status", value: "400"}:                   12,
+		{name: ":status", value: "404"}:                   13,
+		{name: ":status", value: "500"}:                   14,
+		{name: "accept-charset", value: ""}:               15,
+		{name: "accept-encoding", value: "gzip, deflate"}: 16,
+		{name: "accept-language", value: ""}:              17,
+		{name: "accept-ranges", value: ""}:                18,
+		{name: "accept", value: ""}:                       19,
+		{name: "access-control-allow-origin", value: ""}:  20,
+		{name: "age", value: ""}:                          21,
+		{name: "allow", value: ""}:                        22,
+		{name: "authorization", value: ""}:                23,
+		{name: "cache-control", value: ""}:                24,
+		{name: "content-disposition", value: ""}:          25,
+		{name: "content-encoding", value: ""}:             26,
+		{name: "content-language", value: ""}:             27,
+		{name: "content-length", value: ""}:               28,
+		{name: "content-location", value: ""}:             29,
+		{name: "content-range", value: ""}:                30,
+		{name: "content-type", value: ""}:                 31,
+		{name: "cookie", value: ""}:                       32,
+		{name: "date", value: ""}:                         33,
+		{name: "etag", value: ""}:                         34,
+		{name: "expect", value: ""}:                       35,
+		{name: "expires", value: ""}:                      36,
+		{name: "from", value: ""}:                         37,
+		{name: "host", value: ""}:                         38,
+		{name: "if-match", value: ""}:                     39,
+		{name: "if-modified-since", value: ""}:            40,
+		{name: "if-none-match", value: ""}:                41,
+		{name: "if-range", value: ""}:                     42,
+		{name: "if-unmodified-since", value: ""}:          43,
+		{name: "last-modified", value: ""}:                44,
+		{name: "link", value: ""}:                         45,
+		{name: "location", value: ""}:                     46,
+		{name: "max-forwards", value: ""}:                 47,
+		{name: "proxy-authenticate", value: ""}:           48,
+		{name: "proxy-authorization", value: ""}:          49,
+		{name: "range", value: ""}:                        50,
+		{name: "referer", value: ""}:                      51,
+		{name: "refresh", value: ""}:                      52,
+		{name: "retry-after", value: ""}:                  53,
+		{name: "server", value: ""}:                       54,
+		{name: "set-cookie", value: ""}:                   55,
+		{name: "strict-transport-security", value: ""}:    56,
+		{name: "transfer-encoding", value: ""}:            57,
+		{name: "user-agent", value: ""}:                   58,
+		{name: "vary", value: ""}:                         59,
+		{name: "via", value: ""}:                          60,
+		{name: "www-authenticate", value: ""}:             61,
+	},
+	ents: []HeaderField{
+		{Name: ":authority", Value: "", Sensitive: false},
+		{Name: ":method", Value: "GET", Sensitive: false},
+		{Name: ":method", Value: "POST", Sensitive: false},
+		{Name: ":path", Value: "/", Sensitive: false},
+		{Name: ":path", Value: "/index.html", Sensitive: false},
+		{Name: ":scheme", Value: "http", Sensitive: false},
+		{Name: ":scheme", Value: "https", Sensitive: false},
+		{Name: ":status", Value: "200", Sensitive: false},
+		{Name: ":status", Value: "204", Sensitive: false},
+		{Name: ":status", Value: "206", Sensitive: false},
+		{Name: ":status", Value: "304", Sensitive: false},
+		{Name: ":status", Value: "400", Sensitive: false},
+		{Name: ":status", Value: "404", Sensitive: false},
+		{Name: ":status", Value: "500", Sensitive: false},
+		{Name: "accept-charset", Value: "", Sensitive: false},
+		{Name: "accept-encoding", Value: "gzip, deflate", Sensitive: false},
+		{Name: "accept-language", Value: "", Sensitive: false},
+		{Name: "accept-ranges", Value: "", Sensitive: false},
+		{Name: "accept", Value: "", Sensitive: false},
+		{Name: "access-control-allow-origin", Value: "", Sensitive: false},
+		{Name: "age", Value: "", Sensitive: false},
+		{Name: "allow", Value: "", Sensitive: false},
+		{Name: "authorization", Value: "", Sensitive: false},
+		{Name: "cache-control", Value: "", Sensitive: false},
+		{Name: "content-disposition", Value: "", Sensitive: false},
+		{Name: "content-encoding", Value: "", Sensitive: false},
+		{Name: "content-language", Value: "", Sensitive: false},
+		{Name: "content-length", Value: "", Sensitive: false},
+		{Name: "content-location", Value: "", Sensitive: false},
+		{Name: "content-range", Value: "", Sensitive: false},
+		{Name: "content-type", Value: "", Sensitive: false},
+		{Name: "cookie", Value: "", Sensitive: false},
+		{Name: "date", Value: "", Sensitive: false},
+		{Name: "etag", Value: "", Sensitive: false},
+		{Name: "expect", Value: "", Sensitive: false},
+		{Name: "expires", Value: "", Sensitive: false},
+		{Name: "from", Value: "", Sensitive: false},
+		{Name: "host", Value: "", Sensitive: false},
+		{Name: "if-match", Value: "", Sensitive: false},
+		{Name: "if-modified-since", Value: "", Sensitive: false},
+		{Name: "if-none-match", Value: "", Sensitive: false},
+		{Name: "if-range", Value: "", Sensitive: false},
+		{Name: "if-unmodified-since", Value: "", Sensitive: false},
+		{Name: "last-modified", Value: "", Sensitive: false},
+		{Name: "link", Value: "", Sensitive: false},
+		{Name: "location", Value: "", Sensitive: false},
+		{Name: "max-forwards", Value: "", Sensitive: false},
+		{Name: "proxy-authenticate", Value: "", Sensitive: false},
+		{Name: "proxy-authorization", Value: "", Sensitive: false},
+		{Name: "range", Value: "", Sensitive: false},
+		{Name: "referer", Value: "", Sensitive: false},
+		{Name: "refresh", Value: "", Sensitive: false},
+		{Name: "retry-after", Value: "", Sensitive: false},
+		{Name: "server", Value: "", Sensitive: false},
+		{Name: "set-cookie", Value: "", Sensitive: false},
+		{Name: "strict-transport-security", Value: "", Sensitive: false},
+		{Name: "transfer-encoding", Value: "", Sensitive: false},
+		{Name: "user-agent", Value: "", Sensitive: false},
+		{Name: "vary", Value: "", Sensitive: false},
+		{Name: "via", Value: "", Sensitive: false},
+		{Name: "www-authenticate", Value: "", Sensitive: false},
+	},
+}
diff --git a/vendor/golang.org/x/net/http2/hpack/tables.go b/vendor/golang.org/x/net/http2/hpack/tables.go
index a66cfbe..8cbdf3f 100644
--- a/vendor/golang.org/x/net/http2/hpack/tables.go
+++ b/vendor/golang.org/x/net/http2/hpack/tables.go
@@ -96,8 +96,7 @@
 // meaning t.ents is reversed for dynamic tables. Hence, when t is a dynamic
 // table, the return value i actually refers to the entry t.ents[t.len()-i].
 //
-// All tables are assumed to be a dynamic tables except for the global
-// staticTable pointer.
+// All tables are assumed to be a dynamic tables except for the global staticTable.
 //
 // See Section 2.3.3.
 func (t *headerFieldTable) search(f HeaderField) (i uint64, nameValueMatch bool) {
@@ -125,81 +124,6 @@
 	return k + 1
 }
 
-// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07#appendix-B
-var staticTable = newStaticTable()
-var staticTableEntries = [...]HeaderField{
-	{Name: ":authority"},
-	{Name: ":method", Value: "GET"},
-	{Name: ":method", Value: "POST"},
-	{Name: ":path", Value: "/"},
-	{Name: ":path", Value: "/index.html"},
-	{Name: ":scheme", Value: "http"},
-	{Name: ":scheme", Value: "https"},
-	{Name: ":status", Value: "200"},
-	{Name: ":status", Value: "204"},
-	{Name: ":status", Value: "206"},
-	{Name: ":status", Value: "304"},
-	{Name: ":status", Value: "400"},
-	{Name: ":status", Value: "404"},
-	{Name: ":status", Value: "500"},
-	{Name: "accept-charset"},
-	{Name: "accept-encoding", Value: "gzip, deflate"},
-	{Name: "accept-language"},
-	{Name: "accept-ranges"},
-	{Name: "accept"},
-	{Name: "access-control-allow-origin"},
-	{Name: "age"},
-	{Name: "allow"},
-	{Name: "authorization"},
-	{Name: "cache-control"},
-	{Name: "content-disposition"},
-	{Name: "content-encoding"},
-	{Name: "content-language"},
-	{Name: "content-length"},
-	{Name: "content-location"},
-	{Name: "content-range"},
-	{Name: "content-type"},
-	{Name: "cookie"},
-	{Name: "date"},
-	{Name: "etag"},
-	{Name: "expect"},
-	{Name: "expires"},
-	{Name: "from"},
-	{Name: "host"},
-	{Name: "if-match"},
-	{Name: "if-modified-since"},
-	{Name: "if-none-match"},
-	{Name: "if-range"},
-	{Name: "if-unmodified-since"},
-	{Name: "last-modified"},
-	{Name: "link"},
-	{Name: "location"},
-	{Name: "max-forwards"},
-	{Name: "proxy-authenticate"},
-	{Name: "proxy-authorization"},
-	{Name: "range"},
-	{Name: "referer"},
-	{Name: "refresh"},
-	{Name: "retry-after"},
-	{Name: "server"},
-	{Name: "set-cookie"},
-	{Name: "strict-transport-security"},
-	{Name: "transfer-encoding"},
-	{Name: "user-agent"},
-	{Name: "vary"},
-	{Name: "via"},
-	{Name: "www-authenticate"},
-}
-
-func newStaticTable() *headerFieldTable {
-	t := &headerFieldTable{}
-	t.init()
-	for _, e := range staticTableEntries[:] {
-		t.addEntry(e)
-	}
-	return t
-}
-
 var huffmanCodes = [256]uint32{
 	0x1ff8,
 	0x7fffd8,
diff --git a/vendor/golang.org/x/net/http2/http2.go b/vendor/golang.org/x/net/http2/http2.go
index 4c5fb3a..6f2df28 100644
--- a/vendor/golang.org/x/net/http2/http2.go
+++ b/vendor/golang.org/x/net/http2/http2.go
@@ -55,14 +55,14 @@
 	ClientPreface = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
 
 	// SETTINGS_MAX_FRAME_SIZE default
-	// http://http2.github.io/http2-spec/#rfc.section.6.5.2
+	// https://httpwg.org/specs/rfc7540.html#rfc.section.6.5.2
 	initialMaxFrameSize = 16384
 
 	// NextProtoTLS is the NPN/ALPN protocol negotiated during
 	// HTTP/2's TLS setup.
 	NextProtoTLS = "h2"
 
-	// http://http2.github.io/http2-spec/#SettingValues
+	// https://httpwg.org/specs/rfc7540.html#SettingValues
 	initialHeaderTableSize = 4096
 
 	initialWindowSize = 65535 // 6.9.2 Initial Flow Control Window Size
@@ -111,7 +111,7 @@
 // Setting is a setting parameter: which setting it is, and its value.
 type Setting struct {
 	// ID is which setting is being set.
-	// See http://http2.github.io/http2-spec/#SettingValues
+	// See https://httpwg.org/specs/rfc7540.html#SettingFormat
 	ID SettingID
 
 	// Val is the value.
@@ -143,7 +143,7 @@
 }
 
 // A SettingID is an HTTP/2 setting as defined in
-// http://http2.github.io/http2-spec/#iana-settings
+// https://httpwg.org/specs/rfc7540.html#iana-settings
 type SettingID uint16
 
 const (
@@ -365,8 +365,8 @@
 // validPseudoPath reports whether v is a valid :path pseudo-header
 // value. It must be either:
 //
-//	*) a non-empty string starting with '/'
-//	*) the string '*', for OPTIONS requests.
+//   - a non-empty string starting with '/'
+//   - the string '*', for OPTIONS requests.
 //
 // For now this is only used a quick check for deciding when to clean
 // up Opaque URLs before sending requests from the Transport.
diff --git a/vendor/golang.org/x/net/http2/not_go115.go b/vendor/golang.org/x/net/http2/not_go115.go
new file mode 100644
index 0000000..e6c04cf
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/not_go115.go
@@ -0,0 +1,31 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.15
+// +build !go1.15
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+// dialTLSWithContext opens a TLS connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	cn, err := tls.Dial(network, addr, cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := cn.Handshake(); err != nil {
+		return nil, err
+	}
+	if cfg.InsecureSkipVerify {
+		return cn, nil
+	}
+	if err := cn.VerifyHostname(cfg.ServerName); err != nil {
+		return nil, err
+	}
+	return cn, nil
+}
diff --git a/vendor/golang.org/x/net/http2/not_go118.go b/vendor/golang.org/x/net/http2/not_go118.go
new file mode 100644
index 0000000..eab532c
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/not_go118.go
@@ -0,0 +1,17 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.18
+// +build !go1.18
+
+package http2
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+func tlsUnderlyingConn(tc *tls.Conn) net.Conn {
+	return nil
+}
diff --git a/vendor/golang.org/x/net/http2/pipe.go b/vendor/golang.org/x/net/http2/pipe.go
index 2a5399e..684d984 100644
--- a/vendor/golang.org/x/net/http2/pipe.go
+++ b/vendor/golang.org/x/net/http2/pipe.go
@@ -30,6 +30,17 @@
 	io.Reader
 }
 
+// setBuffer initializes the pipe buffer.
+// It has no effect if the pipe is already closed.
+func (p *pipe) setBuffer(b pipeBuffer) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.err != nil || p.breakErr != nil {
+		return
+	}
+	p.b = b
+}
+
 func (p *pipe) Len() int {
 	p.mu.Lock()
 	defer p.mu.Unlock()
@@ -77,13 +88,9 @@
 		p.c.L = &p.mu
 	}
 	defer p.c.Signal()
-	if p.err != nil {
+	if p.err != nil || p.breakErr != nil {
 		return 0, errClosedPipeWrite
 	}
-	if p.breakErr != nil {
-		p.unread += len(d)
-		return len(d), nil // discard when there is no reader
-	}
 	return p.b.Write(d)
 }
 
diff --git a/vendor/golang.org/x/net/http2/server.go b/vendor/golang.org/x/net/http2/server.go
index 193d7c6..cd057f3 100644
--- a/vendor/golang.org/x/net/http2/server.go
+++ b/vendor/golang.org/x/net/http2/server.go
@@ -98,6 +98,19 @@
 	// the HTTP/2 spec's recommendations.
 	MaxConcurrentStreams uint32
 
+	// MaxDecoderHeaderTableSize optionally specifies the http2
+	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
+	// informs the remote endpoint of the maximum size of the header compression
+	// table used to decode header blocks, in octets. If zero, the default value
+	// of 4096 is used.
+	MaxDecoderHeaderTableSize uint32
+
+	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
+	// header compression table used for encoding request headers. Received
+	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
+	// the default value of 4096 is used.
+	MaxEncoderHeaderTableSize uint32
+
 	// MaxReadFrameSize optionally specifies the largest frame
 	// this server is willing to read. A valid value is between
 	// 16k and 16M, inclusive. If zero or otherwise invalid, a
@@ -130,6 +143,12 @@
 	// If nil, a default scheduler is chosen.
 	NewWriteScheduler func() WriteScheduler
 
+	// CountError, if non-nil, is called on HTTP/2 server errors.
+	// It's intended to increment a metric for monitoring, such
+	// as an expvar or Prometheus metric.
+	// The errType consists of only ASCII word characters.
+	CountError func(errType string)
+
 	// Internal state. This is a pointer (rather than embedded directly)
 	// so that we don't embed a Mutex in this struct, which will make the
 	// struct non-copyable, which might break some callers.
@@ -137,7 +156,7 @@
 }
 
 func (s *Server) initialConnRecvWindowSize() int32 {
-	if s.MaxUploadBufferPerConnection > initialWindowSize {
+	if s.MaxUploadBufferPerConnection >= initialWindowSize {
 		return s.MaxUploadBufferPerConnection
 	}
 	return 1 << 20
@@ -164,6 +183,20 @@
 	return defaultMaxStreams
 }
 
+func (s *Server) maxDecoderHeaderTableSize() uint32 {
+	if v := s.MaxDecoderHeaderTableSize; v > 0 {
+		return v
+	}
+	return initialHeaderTableSize
+}
+
+func (s *Server) maxEncoderHeaderTableSize() uint32 {
+	if v := s.MaxEncoderHeaderTableSize; v > 0 {
+		return v
+	}
+	return initialHeaderTableSize
+}
+
 // maxQueuedControlFrames is the maximum number of control frames like
 // SETTINGS, PING and RST_STREAM that will be queued for writing before
 // the connection is closed to prevent memory exhaustion attacks.
@@ -231,13 +264,12 @@
 
 	if s.TLSConfig == nil {
 		s.TLSConfig = new(tls.Config)
-	} else if s.TLSConfig.CipherSuites != nil {
-		// If they already provided a CipherSuite list, return
-		// an error if it has a bad order or is missing
-		// ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
+	} else if s.TLSConfig.CipherSuites != nil && s.TLSConfig.MinVersion < tls.VersionTLS13 {
+		// If they already provided a TLS 1.0–1.2 CipherSuite list, return an
+		// error if it is missing ECDHE_RSA_WITH_AES_128_GCM_SHA256 or
+		// ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
 		haveRequired := false
-		sawBad := false
-		for i, cs := range s.TLSConfig.CipherSuites {
+		for _, cs := range s.TLSConfig.CipherSuites {
 			switch cs {
 			case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 				// Alternative MTI cipher to not discourage ECDSA-only servers.
@@ -245,14 +277,9 @@
 				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
 				haveRequired = true
 			}
-			if isBadCipher(cs) {
-				sawBad = true
-			} else if sawBad {
-				return fmt.Errorf("http2: TLSConfig.CipherSuites index %d contains an HTTP/2-approved cipher suite (%#04x), but it comes after unapproved cipher suites. With this configuration, clients that don't support previous, approved cipher suites may be given an unapproved one and reject the connection.", i, cs)
-			}
 		}
 		if !haveRequired {
-			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).")
+			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)")
 		}
 	}
 
@@ -265,16 +292,12 @@
 
 	s.TLSConfig.PreferServerCipherSuites = true
 
-	haveNPN := false
-	for _, p := range s.TLSConfig.NextProtos {
-		if p == NextProtoTLS {
-			haveNPN = true
-			break
-		}
-	}
-	if !haveNPN {
+	if !strSliceContains(s.TLSConfig.NextProtos, NextProtoTLS) {
 		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, NextProtoTLS)
 	}
+	if !strSliceContains(s.TLSConfig.NextProtos, "http/1.1") {
+		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "http/1.1")
+	}
 
 	if s.TLSNextProto == nil {
 		s.TLSNextProto = map[string]func(*http.Server, *tls.Conn, http.Handler){}
@@ -319,6 +342,20 @@
 	// requests. If nil, BaseConfig.Handler is used. If BaseConfig
 	// or BaseConfig.Handler is nil, http.DefaultServeMux is used.
 	Handler http.Handler
+
+	// UpgradeRequest is an initial request received on a connection
+	// undergoing an h2c upgrade. The request body must have been
+	// completely read from the connection before calling ServeConn,
+	// and the 101 Switching Protocols response written.
+	UpgradeRequest *http.Request
+
+	// Settings is the decoded contents of the HTTP2-Settings header
+	// in an h2c upgrade request.
+	Settings []byte
+
+	// SawClientPreface is set if the HTTP/2 connection preface
+	// has already been read from the connection.
+	SawClientPreface bool
 }
 
 func (o *ServeConnOpts) context() context.Context {
@@ -384,9 +421,9 @@
 		advMaxStreams:               s.maxConcurrentStreams(),
 		initialStreamSendWindowSize: initialWindowSize,
 		maxFrameSize:                initialMaxFrameSize,
-		headerTableSize:             initialHeaderTableSize,
 		serveG:                      newGoroutineLock(),
 		pushEnabled:                 true,
+		sawClientPreface:            opts.SawClientPreface,
 	}
 
 	s.state.registerConn(sc)
@@ -404,18 +441,22 @@
 	if s.NewWriteScheduler != nil {
 		sc.writeSched = s.NewWriteScheduler()
 	} else {
-		sc.writeSched = NewRandomWriteScheduler()
+		sc.writeSched = NewPriorityWriteScheduler(nil)
 	}
 
 	// These start at the RFC-specified defaults. If there is a higher
 	// configured value for inflow, that will be updated when we send a
 	// WINDOW_UPDATE shortly after sending SETTINGS.
 	sc.flow.add(initialWindowSize)
-	sc.inflow.add(initialWindowSize)
+	sc.inflow.init(initialWindowSize)
 	sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
+	sc.hpackEncoder.SetMaxDynamicTableSizeLimit(s.maxEncoderHeaderTableSize())
 
 	fr := NewFramer(sc.bw, c)
-	fr.ReadMetaHeaders = hpack.NewDecoder(initialHeaderTableSize, nil)
+	if s.CountError != nil {
+		fr.countError = s.CountError
+	}
+	fr.ReadMetaHeaders = hpack.NewDecoder(s.maxDecoderHeaderTableSize(), nil)
 	fr.MaxHeaderListSize = sc.maxHeaderListSize()
 	fr.SetMaxReadFrameSize(s.maxReadFrameSize())
 	sc.framer = fr
@@ -466,9 +507,27 @@
 		}
 	}
 
+	if opts.Settings != nil {
+		fr := &SettingsFrame{
+			FrameHeader: FrameHeader{valid: true},
+			p:           opts.Settings,
+		}
+		if err := fr.ForeachSetting(sc.processSetting); err != nil {
+			sc.rejectConn(ErrCodeProtocol, "invalid settings")
+			return
+		}
+		opts.Settings = nil
+	}
+
 	if hook := testHookGetServerConn; hook != nil {
 		hook(sc)
 	}
+
+	if opts.UpgradeRequest != nil {
+		sc.upgradeRequest(opts.UpgradeRequest)
+		opts.UpgradeRequest = nil
+	}
+
 	sc.serve()
 }
 
@@ -504,8 +563,8 @@
 	wroteFrameCh     chan frameWriteResult  // from writeFrameAsync -> serve, tickles more frame writes
 	bodyReadCh       chan bodyReadMsg       // from handlers -> serve
 	serveMsgCh       chan interface{}       // misc messages & code to send to / run on the serve loop
-	flow             flow                   // conn-wide (not stream-specific) outbound flow control
-	inflow           flow                   // conn-wide inbound flow control
+	flow             outflow                // conn-wide (not stream-specific) outbound flow control
+	inflow           inflow                 // conn-wide inbound flow control
 	tlsState         *tls.ConnectionState   // shared by all handlers, like net/http
 	remoteAddrStr    string
 	writeSched       WriteScheduler
@@ -513,6 +572,7 @@
 	// Everything following is owned by the serve loop; use serveG.check():
 	serveG                      goroutineLock // used to verify funcs are on serve()
 	pushEnabled                 bool
+	sawClientPreface            bool // preface has already been read, used in h2c upgrade
 	sawFirstSettings            bool // got the initial SETTINGS frame after the preface
 	needToSendSettingsAck       bool
 	unackedSettings             int    // how many SETTINGS have we sent without ACKs?
@@ -526,9 +586,9 @@
 	streams                     map[uint32]*stream
 	initialStreamSendWindowSize int32
 	maxFrameSize                int32
-	headerTableSize             uint32
 	peerMaxHeaderListSize       uint32            // zero means unknown (default)
 	canonHeader                 map[string]string // http2-lower-case -> Go-Canonical-Case
+	canonHeaderKeysSize         int               // canonHeader keys size in bytes
 	writingFrame                bool              // started writing a frame (on serve goroutine or separate)
 	writingFrameAsync           bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
 	needsFrameFlush             bool              // last frame write wasn't a flush
@@ -581,15 +641,17 @@
 	cancelCtx func()
 
 	// owned by serverConn's serve loop:
-	bodyBytes        int64 // body bytes seen so far
-	declBodyBytes    int64 // or -1 if undeclared
-	flow             flow  // limits writing from Handler to client
-	inflow           flow  // what the client is allowed to POST/etc to us
+	bodyBytes        int64   // body bytes seen so far
+	declBodyBytes    int64   // or -1 if undeclared
+	flow             outflow // limits writing from Handler to client
+	inflow           inflow  // what the client is allowed to POST/etc to us
 	state            streamState
 	resetQueued      bool        // RST_STREAM queued for write; set by sc.resetStream
 	gotTrailerHeader bool        // HEADER frame for trailers was seen
 	wroteHeaders     bool        // whether we wrote headers (not status 100)
+	readDeadline     *time.Timer // nil if unused
 	writeDeadline    *time.Timer // nil if unused
+	closeErr         error       // set before cw is closed
 
 	trailer    http.Header // accumulated trailers
 	reqTrailer http.Header // handler's Request.Trailer
@@ -705,6 +767,13 @@
 	}
 }
 
+// maxCachedCanonicalHeadersKeysSize is an arbitrarily-chosen limit on the size
+// of the entries in the canonHeader cache.
+// This should be larger than the size of unique, uncommon header keys likely to
+// be sent by the peer, while not so high as to permit unreasonable memory usage
+// if the peer sends an unbounded number of unique header keys.
+const maxCachedCanonicalHeadersKeysSize = 2048
+
 func (sc *serverConn) canonicalHeader(v string) string {
 	sc.serveG.check()
 	buildCommonHeaderMapsOnce()
@@ -720,7 +789,11 @@
 		sc.canonHeader = make(map[string]string)
 	}
 	cv = http.CanonicalHeaderKey(v)
-	sc.canonHeader[v] = cv
+	size := 100 + len(v)*2 // 100 bytes of map overhead + key + value
+	if sc.canonHeaderKeysSize+size <= maxCachedCanonicalHeadersKeysSize {
+		sc.canonHeader[v] = cv
+		sc.canonHeaderKeysSize += size
+	}
 	return cv
 }
 
@@ -770,8 +843,13 @@
 // and then reports when it's done.
 // At most one goroutine can be running writeFrameAsync at a time per
 // serverConn.
-func (sc *serverConn) writeFrameAsync(wr FrameWriteRequest) {
-	err := wr.write.writeFrame(sc)
+func (sc *serverConn) writeFrameAsync(wr FrameWriteRequest, wd *writeData) {
+	var err error
+	if wd == nil {
+		err = wr.write.writeFrame(sc)
+	} else {
+		err = sc.framer.endWrite()
+	}
 	sc.wroteFrameCh <- frameWriteResult{wr: wr, err: err}
 }
 
@@ -821,12 +899,13 @@
 			{SettingMaxFrameSize, sc.srv.maxReadFrameSize()},
 			{SettingMaxConcurrentStreams, sc.advMaxStreams},
 			{SettingMaxHeaderListSize, sc.maxHeaderListSize()},
+			{SettingHeaderTableSize, sc.srv.maxDecoderHeaderTableSize()},
 			{SettingInitialWindowSize, uint32(sc.srv.initialStreamRecvWindowSize())},
 		},
 	})
 	sc.unackedSettings++
 
-	// Each connection starts with intialWindowSize inflow tokens.
+	// Each connection starts with initialWindowSize inflow tokens.
 	// If a higher value is configured, we add more tokens.
 	if diff := sc.srv.initialConnRecvWindowSize() - initialWindowSize; diff > 0 {
 		sc.sendWindowUpdate(nil, int(diff))
@@ -866,6 +945,15 @@
 		case res := <-sc.wroteFrameCh:
 			sc.wroteFrame(res)
 		case res := <-sc.readFrameCh:
+			// Process any written frames before reading new frames from the client since a
+			// written frame could have triggered a new stream to be started.
+			if sc.writingFrameAsync {
+				select {
+				case wroteRes := <-sc.wroteFrameCh:
+					sc.wroteFrame(wroteRes)
+				default:
+				}
+			}
 			if !sc.processFrameFromReader(res) {
 				return
 			}
@@ -898,6 +986,8 @@
 				}
 			case *startPushRequest:
 				sc.startPush(v)
+			case func(*serverConn):
+				v(sc)
 			default:
 				panic(fmt.Sprintf("unexpected type %T", v))
 			}
@@ -958,6 +1048,9 @@
 // returns errPrefaceTimeout on timeout, or an error if the greeting
 // is invalid.
 func (sc *serverConn) readPreface() error {
+	if sc.sawClientPreface {
+		return nil
+	}
 	errc := make(chan error, 1)
 	go func() {
 		// Read the client preface
@@ -1163,9 +1256,16 @@
 		sc.writingFrameAsync = false
 		err := wr.write.writeFrame(sc)
 		sc.wroteFrame(frameWriteResult{wr: wr, err: err})
+	} else if wd, ok := wr.write.(*writeData); ok {
+		// Encode the frame in the serve goroutine, to ensure we don't have
+		// any lingering asynchronous references to data passed to Write.
+		// See https://go.dev/issue/58446.
+		sc.framer.startWriteDataPadded(wd.streamID, wd.endStream, wd.p, nil)
+		sc.writingFrameAsync = true
+		go sc.writeFrameAsync(wr, wd)
 	} else {
 		sc.writingFrameAsync = true
-		go sc.writeFrameAsync(wr)
+		go sc.writeFrameAsync(wr, nil)
 	}
 }
 
@@ -1318,6 +1418,9 @@
 func (sc *serverConn) goAway(code ErrCode) {
 	sc.serveG.check()
 	if sc.inGoAway {
+		if sc.goAwayCode == ErrCodeNo {
+			sc.goAwayCode = code
+		}
 		return
 	}
 	sc.inGoAway = true
@@ -1400,11 +1503,26 @@
 	// First frame received must be SETTINGS.
 	if !sc.sawFirstSettings {
 		if _, ok := f.(*SettingsFrame); !ok {
-			return ConnectionError(ErrCodeProtocol)
+			return sc.countError("first_settings", ConnectionError(ErrCodeProtocol))
 		}
 		sc.sawFirstSettings = true
 	}
 
+	// Discard frames for streams initiated after the identified last
+	// stream sent in a GOAWAY, or all frames after sending an error.
+	// We still need to return connection-level flow control for DATA frames.
+	// RFC 9113 Section 6.8.
+	if sc.inGoAway && (sc.goAwayCode != ErrCodeNo || f.Header().StreamID > sc.maxClientStreamID) {
+
+		if f, ok := f.(*DataFrame); ok {
+			if !sc.inflow.take(f.Length) {
+				return sc.countError("data_flow", streamError(f.Header().StreamID, ErrCodeFlowControl))
+			}
+			sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
+		}
+		return nil
+	}
+
 	switch f := f.(type) {
 	case *SettingsFrame:
 		return sc.processSettings(f)
@@ -1425,7 +1543,7 @@
 	case *PushPromiseFrame:
 		// A client cannot push. Thus, servers MUST treat the receipt of a PUSH_PROMISE
 		// frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("push_promise", ConnectionError(ErrCodeProtocol))
 	default:
 		sc.vlogf("http2: server ignoring frame: %v", f.Header())
 		return nil
@@ -1445,10 +1563,7 @@
 		// identifier field value other than 0x0, the recipient MUST
 		// respond with a connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR."
-		return ConnectionError(ErrCodeProtocol)
-	}
-	if sc.inGoAway && sc.goAwayCode != ErrCodeNo {
-		return nil
+		return sc.countError("ping_on_stream", ConnectionError(ErrCodeProtocol))
 	}
 	sc.writeFrame(FrameWriteRequest{write: writePingAck{f}})
 	return nil
@@ -1464,7 +1579,7 @@
 			// or PRIORITY on a stream in this state MUST be
 			// treated as a connection error (Section 5.4.1) of
 			// type PROTOCOL_ERROR."
-			return ConnectionError(ErrCodeProtocol)
+			return sc.countError("stream_idle", ConnectionError(ErrCodeProtocol))
 		}
 		if st == nil {
 			// "WINDOW_UPDATE can be sent by a peer that has sent a
@@ -1475,7 +1590,7 @@
 			return nil
 		}
 		if !st.flow.add(int32(f.Increment)) {
-			return streamError(f.StreamID, ErrCodeFlowControl)
+			return sc.countError("bad_flow", streamError(f.StreamID, ErrCodeFlowControl))
 		}
 	default: // connection-level flow control
 		if !sc.flow.add(int32(f.Increment)) {
@@ -1496,7 +1611,7 @@
 		// identifying an idle stream is received, the
 		// recipient MUST treat this as a connection error
 		// (Section 5.4.1) of type PROTOCOL_ERROR.
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("reset_idle_stream", ConnectionError(ErrCodeProtocol))
 	}
 	if st != nil {
 		st.cancelCtx()
@@ -1511,6 +1626,9 @@
 		panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state))
 	}
 	st.state = stateClosed
+	if st.readDeadline != nil {
+		st.readDeadline.Stop()
+	}
 	if st.writeDeadline != nil {
 		st.writeDeadline.Stop()
 	}
@@ -1536,6 +1654,14 @@
 
 		p.CloseWithError(err)
 	}
+	if e, ok := err.(StreamError); ok {
+		if e.Cause != nil {
+			err = e.Cause
+		} else {
+			err = errStreamClosed
+		}
+	}
+	st.closeErr = err
 	st.cw.Close() // signals Handler's CloseNotifier, unblocks writes, etc
 	sc.writeSched.CloseStream(st.id)
 }
@@ -1548,7 +1674,7 @@
 			// Why is the peer ACKing settings we never sent?
 			// The spec doesn't mention this case, but
 			// hang up on them anyway.
-			return ConnectionError(ErrCodeProtocol)
+			return sc.countError("ack_mystery", ConnectionError(ErrCodeProtocol))
 		}
 		return nil
 	}
@@ -1556,7 +1682,7 @@
 		// This isn't actually in the spec, but hang up on
 		// suspiciously large settings frames or those with
 		// duplicate entries.
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("settings_big_or_dups", ConnectionError(ErrCodeProtocol))
 	}
 	if err := f.ForeachSetting(sc.processSetting); err != nil {
 		return err
@@ -1578,7 +1704,6 @@
 	}
 	switch s.ID {
 	case SettingHeaderTableSize:
-		sc.headerTableSize = s.Val
 		sc.hpackEncoder.SetMaxDynamicTableSize(s.Val)
 	case SettingEnablePush:
 		sc.pushEnabled = s.Val != 0
@@ -1623,7 +1748,7 @@
 			// control window to exceed the maximum size as a
 			// connection error (Section 5.4.1) of type
 			// FLOW_CONTROL_ERROR."
-			return ConnectionError(ErrCodeFlowControl)
+			return sc.countError("setting_win_size", ConnectionError(ErrCodeFlowControl))
 		}
 	}
 	return nil
@@ -1632,16 +1757,6 @@
 func (sc *serverConn) processData(f *DataFrame) error {
 	sc.serveG.check()
 	id := f.Header().StreamID
-	if sc.inGoAway && (sc.goAwayCode != ErrCodeNo || id > sc.maxClientStreamID) {
-		// Discard all DATA frames if the GOAWAY is due to an
-		// error, or:
-		//
-		// Section 6.8: After sending a GOAWAY frame, the sender
-		// can discard frames for streams initiated by the
-		// receiver with identifiers higher than the identified
-		// last stream.
-		return nil
-	}
 
 	data := f.Data()
 	state, st := sc.state(id)
@@ -1656,7 +1771,7 @@
 		// or PRIORITY on a stream in this state MUST be
 		// treated as a connection error (Section 5.4.1) of
 		// type PROTOCOL_ERROR."
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("data_on_idle", ConnectionError(ErrCodeProtocol))
 	}
 
 	// "If a DATA frame is received whose stream is not in "open"
@@ -1672,21 +1787,16 @@
 		// But still enforce their connection-level flow control,
 		// and return any flow control bytes since we're not going
 		// to consume them.
-		if sc.inflow.available() < int32(f.Length) {
-			return streamError(id, ErrCodeFlowControl)
+		if !sc.inflow.take(f.Length) {
+			return sc.countError("data_flow", streamError(id, ErrCodeFlowControl))
 		}
-		// Deduct the flow control from inflow, since we're
-		// going to immediately add it back in
-		// sendWindowUpdate, which also schedules sending the
-		// frames.
-		sc.inflow.take(int32(f.Length))
 		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
 
 		if st != nil && st.resetQueued {
 			// Already have a stream error in flight. Don't send another.
 			return nil
 		}
-		return streamError(id, ErrCodeStreamClosed)
+		return sc.countError("closed", streamError(id, ErrCodeStreamClosed))
 	}
 	if st.body == nil {
 		panic("internal error: should have a body in this state")
@@ -1694,37 +1804,46 @@
 
 	// Sender sending more than they'd declared?
 	if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes {
+		if !sc.inflow.take(f.Length) {
+			return sc.countError("data_flow", streamError(id, ErrCodeFlowControl))
+		}
+		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
+
 		st.body.CloseWithError(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes))
 		// RFC 7540, sec 8.1.2.6: A request or response is also malformed if the
 		// value of a content-length header field does not equal the sum of the
 		// DATA frame payload lengths that form the body.
-		return streamError(id, ErrCodeProtocol)
+		return sc.countError("send_too_much", streamError(id, ErrCodeProtocol))
 	}
 	if f.Length > 0 {
 		// Check whether the client has flow control quota.
-		if st.inflow.available() < int32(f.Length) {
-			return streamError(id, ErrCodeFlowControl)
+		if !takeInflows(&sc.inflow, &st.inflow, f.Length) {
+			return sc.countError("flow_on_data_length", streamError(id, ErrCodeFlowControl))
 		}
-		st.inflow.take(int32(f.Length))
 
 		if len(data) > 0 {
+			st.bodyBytes += int64(len(data))
 			wrote, err := st.body.Write(data)
 			if err != nil {
+				// The handler has closed the request body.
+				// Return the connection-level flow control for the discarded data,
+				// but not the stream-level flow control.
 				sc.sendWindowUpdate(nil, int(f.Length)-wrote)
-				return streamError(id, ErrCodeStreamClosed)
+				return nil
 			}
 			if wrote != len(data) {
 				panic("internal error: bad Writer")
 			}
-			st.bodyBytes += int64(len(data))
 		}
 
 		// Return any padded flow control now, since we won't
 		// refund it later on body reads.
-		if pad := int32(f.Length) - int32(len(data)); pad > 0 {
-			sc.sendWindowUpdate32(nil, pad)
-			sc.sendWindowUpdate32(st, pad)
-		}
+		// Call sendWindowUpdate even if there is no padding,
+		// to return buffered flow control credit if the sent
+		// window has shrunk.
+		pad := int32(f.Length) - int32(len(data))
+		sc.sendWindowUpdate32(nil, pad)
+		sc.sendWindowUpdate32(st, pad)
 	}
 	if f.StreamEnded() {
 		st.endStream()
@@ -1778,26 +1897,34 @@
 	}
 }
 
+// onReadTimeout is run on its own goroutine (from time.AfterFunc)
+// when the stream's ReadTimeout has fired.
+func (st *stream) onReadTimeout() {
+	// Wrap the ErrDeadlineExceeded to avoid callers depending on us
+	// returning the bare error.
+	st.body.CloseWithError(fmt.Errorf("%w", os.ErrDeadlineExceeded))
+}
+
 // onWriteTimeout is run on its own goroutine (from time.AfterFunc)
 // when the stream's WriteTimeout has fired.
 func (st *stream) onWriteTimeout() {
-	st.sc.writeFrameFromHandler(FrameWriteRequest{write: streamError(st.id, ErrCodeInternal)})
+	st.sc.writeFrameFromHandler(FrameWriteRequest{write: StreamError{
+		StreamID: st.id,
+		Code:     ErrCodeInternal,
+		Cause:    os.ErrDeadlineExceeded,
+	}})
 }
 
 func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	sc.serveG.check()
 	id := f.StreamID
-	if sc.inGoAway {
-		// Ignore.
-		return nil
-	}
 	// http://tools.ietf.org/html/rfc7540#section-5.1.1
 	// Streams initiated by a client MUST use odd-numbered stream
 	// identifiers. [...] An endpoint that receives an unexpected
 	// stream identifier MUST respond with a connection error
 	// (Section 5.4.1) of type PROTOCOL_ERROR.
 	if id%2 != 1 {
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("headers_even", ConnectionError(ErrCodeProtocol))
 	}
 	// A HEADERS frame can be used to create a new stream or
 	// send a trailer for an open one. If we already have a stream
@@ -1814,7 +1941,7 @@
 		// this state, it MUST respond with a stream error (Section 5.4.2) of
 		// type STREAM_CLOSED.
 		if st.state == stateHalfClosedRemote {
-			return streamError(id, ErrCodeStreamClosed)
+			return sc.countError("headers_half_closed", streamError(id, ErrCodeStreamClosed))
 		}
 		return st.processTrailerHeaders(f)
 	}
@@ -1825,7 +1952,7 @@
 	// receives an unexpected stream identifier MUST respond with
 	// a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
 	if id <= sc.maxClientStreamID {
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("stream_went_down", ConnectionError(ErrCodeProtocol))
 	}
 	sc.maxClientStreamID = id
 
@@ -1842,14 +1969,14 @@
 	if sc.curClientStreams+1 > sc.advMaxStreams {
 		if sc.unackedSettings == 0 {
 			// They should know better.
-			return streamError(id, ErrCodeProtocol)
+			return sc.countError("over_max_streams", streamError(id, ErrCodeProtocol))
 		}
 		// Assume it's a network race, where they just haven't
 		// received our last SETTINGS update. But actually
 		// this can't happen yet, because we don't yet provide
 		// a way for users to adjust server parameters at
 		// runtime.
-		return streamError(id, ErrCodeRefusedStream)
+		return sc.countError("over_max_streams_race", streamError(id, ErrCodeRefusedStream))
 	}
 
 	initialState := stateOpen
@@ -1859,7 +1986,7 @@
 	st := sc.newStream(id, 0, initialState)
 
 	if f.HasPriority() {
-		if err := checkPriority(f.StreamID, f.Priority); err != nil {
+		if err := sc.checkPriority(f.StreamID, f.Priority); err != nil {
 			return err
 		}
 		sc.writeSched.AdjustStream(st.id, f.Priority)
@@ -1893,25 +2020,48 @@
 	// (in Go 1.8), though. That's a more sane option anyway.
 	if sc.hs.ReadTimeout != 0 {
 		sc.conn.SetReadDeadline(time.Time{})
+		if st.body != nil {
+			st.readDeadline = time.AfterFunc(sc.hs.ReadTimeout, st.onReadTimeout)
+		}
 	}
 
 	go sc.runHandler(rw, req, handler)
 	return nil
 }
 
+func (sc *serverConn) upgradeRequest(req *http.Request) {
+	sc.serveG.check()
+	id := uint32(1)
+	sc.maxClientStreamID = id
+	st := sc.newStream(id, 0, stateHalfClosedRemote)
+	st.reqTrailer = req.Trailer
+	if st.reqTrailer != nil {
+		st.trailer = make(http.Header)
+	}
+	rw := sc.newResponseWriter(st, req)
+
+	// Disable any read deadline set by the net/http package
+	// prior to the upgrade.
+	if sc.hs.ReadTimeout != 0 {
+		sc.conn.SetReadDeadline(time.Time{})
+	}
+
+	go sc.runHandler(rw, req, sc.handler.ServeHTTP)
+}
+
 func (st *stream) processTrailerHeaders(f *MetaHeadersFrame) error {
 	sc := st.sc
 	sc.serveG.check()
 	if st.gotTrailerHeader {
-		return ConnectionError(ErrCodeProtocol)
+		return sc.countError("dup_trailers", ConnectionError(ErrCodeProtocol))
 	}
 	st.gotTrailerHeader = true
 	if !f.StreamEnded() {
-		return streamError(st.id, ErrCodeProtocol)
+		return sc.countError("trailers_not_ended", streamError(st.id, ErrCodeProtocol))
 	}
 
 	if len(f.PseudoFields()) > 0 {
-		return streamError(st.id, ErrCodeProtocol)
+		return sc.countError("trailers_pseudo", streamError(st.id, ErrCodeProtocol))
 	}
 	if st.trailer != nil {
 		for _, hf := range f.RegularFields() {
@@ -1920,7 +2070,7 @@
 				// TODO: send more details to the peer somehow. But http2 has
 				// no way to send debug data at a stream level. Discuss with
 				// HTTP folk.
-				return streamError(st.id, ErrCodeProtocol)
+				return sc.countError("trailers_bogus", streamError(st.id, ErrCodeProtocol))
 			}
 			st.trailer[key] = append(st.trailer[key], hf.Value)
 		}
@@ -1929,22 +2079,19 @@
 	return nil
 }
 
-func checkPriority(streamID uint32, p PriorityParam) error {
+func (sc *serverConn) checkPriority(streamID uint32, p PriorityParam) error {
 	if streamID == p.StreamDep {
 		// Section 5.3.1: "A stream cannot depend on itself. An endpoint MUST treat
 		// this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR."
 		// Section 5.3.3 says that a stream can depend on one of its dependencies,
 		// so it's only self-dependencies that are forbidden.
-		return streamError(streamID, ErrCodeProtocol)
+		return sc.countError("priority", streamError(streamID, ErrCodeProtocol))
 	}
 	return nil
 }
 
 func (sc *serverConn) processPriority(f *PriorityFrame) error {
-	if sc.inGoAway {
-		return nil
-	}
-	if err := checkPriority(f.StreamID, f.PriorityParam); err != nil {
+	if err := sc.checkPriority(f.StreamID, f.PriorityParam); err != nil {
 		return err
 	}
 	sc.writeSched.AdjustStream(f.StreamID, f.PriorityParam)
@@ -1968,8 +2115,7 @@
 	st.cw.Init()
 	st.flow.conn = &sc.flow // link to conn-level counter
 	st.flow.add(sc.initialStreamSendWindowSize)
-	st.inflow.conn = &sc.inflow // link to conn-level counter
-	st.inflow.add(sc.srv.initialStreamRecvWindowSize())
+	st.inflow.init(sc.srv.initialStreamRecvWindowSize())
 	if sc.hs.WriteTimeout != 0 {
 		st.writeDeadline = time.AfterFunc(sc.hs.WriteTimeout, st.onWriteTimeout)
 	}
@@ -2001,7 +2147,7 @@
 	isConnect := rp.method == "CONNECT"
 	if isConnect {
 		if rp.path != "" || rp.scheme != "" || rp.authority == "" {
-			return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+			return nil, nil, sc.countError("bad_connect", streamError(f.StreamID, ErrCodeProtocol))
 		}
 	} else if rp.method == "" || rp.path == "" || (rp.scheme != "https" && rp.scheme != "http") {
 		// See 8.1.2.6 Malformed Requests and Responses:
@@ -2014,13 +2160,7 @@
 		// "All HTTP/2 requests MUST include exactly one valid
 		// value for the :method, :scheme, and :path
 		// pseudo-header fields"
-		return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
-	}
-
-	bodyOpen := !f.StreamEnded()
-	if rp.method == "HEAD" && bodyOpen {
-		// HEAD requests can't have bodies
-		return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+		return nil, nil, sc.countError("bad_path_method", streamError(f.StreamID, ErrCodeProtocol))
 	}
 
 	rp.header = make(http.Header)
@@ -2035,6 +2175,7 @@
 	if err != nil {
 		return nil, nil, err
 	}
+	bodyOpen := !f.StreamEnded()
 	if bodyOpen {
 		if vv, ok := rp.header["Content-Length"]; ok {
 			if cl, err := strconv.ParseUint(vv[0], 10, 63); err == nil {
@@ -2066,7 +2207,7 @@
 		tlsState = sc.tlsState
 	}
 
-	needsContinue := rp.header.Get("Expect") == "100-continue"
+	needsContinue := httpguts.HeaderValuesContainsToken(rp.header["Expect"], "100-continue")
 	if needsContinue {
 		rp.header.Del("Expect")
 	}
@@ -2103,7 +2244,7 @@
 		var err error
 		url_, err = url.ParseRequestURI(rp.path)
 		if err != nil {
-			return nil, nil, streamError(st.id, ErrCodeProtocol)
+			return nil, nil, sc.countError("bad_path", streamError(st.id, ErrCodeProtocol))
 		}
 		requestURI = rp.path
 	}
@@ -2129,6 +2270,11 @@
 	}
 	req = req.WithContext(st.ctx)
 
+	rw := sc.newResponseWriter(st, req)
+	return rw, req, nil
+}
+
+func (sc *serverConn) newResponseWriter(st *stream, req *http.Request) *responseWriter {
 	rws := responseWriterStatePool.Get().(*responseWriterState)
 	bwSave := rws.bw
 	*rws = responseWriterState{} // zero all the fields
@@ -2137,10 +2283,7 @@
 	rws.bw.Reset(chunkWriter{rws})
 	rws.stream = st
 	rws.req = req
-	rws.body = body
-
-	rw := &responseWriter{rws: rws}
-	return rw, req, nil
+	return &responseWriter{rws: rws}
 }
 
 // Run on its own goroutine.
@@ -2148,6 +2291,9 @@
 	didPanic := true
 	defer func() {
 		rw.rws.stream.cancelCtx()
+		if req.MultipartForm != nil {
+			req.MultipartForm.RemoveAll()
+		}
 		if didPanic {
 			e := recover()
 			sc.writeFrameFromHandler(FrameWriteRequest{
@@ -2251,47 +2397,28 @@
 }
 
 // st may be nil for conn-level
-func (sc *serverConn) sendWindowUpdate(st *stream, n int) {
-	sc.serveG.check()
-	// "The legal range for the increment to the flow control
-	// window is 1 to 2^31-1 (2,147,483,647) octets."
-	// A Go Read call on 64-bit machines could in theory read
-	// a larger Read than this. Very unlikely, but we handle it here
-	// rather than elsewhere for now.
-	const maxUint31 = 1<<31 - 1
-	for n >= maxUint31 {
-		sc.sendWindowUpdate32(st, maxUint31)
-		n -= maxUint31
-	}
-	sc.sendWindowUpdate32(st, int32(n))
+func (sc *serverConn) sendWindowUpdate32(st *stream, n int32) {
+	sc.sendWindowUpdate(st, int(n))
 }
 
 // st may be nil for conn-level
-func (sc *serverConn) sendWindowUpdate32(st *stream, n int32) {
+func (sc *serverConn) sendWindowUpdate(st *stream, n int) {
 	sc.serveG.check()
-	if n == 0 {
+	var streamID uint32
+	var send int32
+	if st == nil {
+		send = sc.inflow.add(n)
+	} else {
+		streamID = st.id
+		send = st.inflow.add(n)
+	}
+	if send == 0 {
 		return
 	}
-	if n < 0 {
-		panic("negative update")
-	}
-	var streamID uint32
-	if st != nil {
-		streamID = st.id
-	}
 	sc.writeFrame(FrameWriteRequest{
-		write:  writeWindowUpdate{streamID: streamID, n: uint32(n)},
+		write:  writeWindowUpdate{streamID: streamID, n: uint32(send)},
 		stream: st,
 	})
-	var ok bool
-	if st == nil {
-		ok = sc.inflow.add(n)
-	} else {
-		ok = st.inflow.add(n)
-	}
-	if !ok {
-		panic("internal error; sent too many window updates without decrements?")
-	}
 }
 
 // requestBody is the Handler's Request.Body type.
@@ -2300,17 +2427,18 @@
 	_             incomparable
 	stream        *stream
 	conn          *serverConn
-	closed        bool  // for use by Close only
-	sawEOF        bool  // for use by Read only
-	pipe          *pipe // non-nil if we have a HTTP entity message body
-	needsContinue bool  // need to send a 100-continue
+	closeOnce     sync.Once // for use by Close only
+	sawEOF        bool      // for use by Read only
+	pipe          *pipe     // non-nil if we have a HTTP entity message body
+	needsContinue bool      // need to send a 100-continue
 }
 
 func (b *requestBody) Close() error {
-	if b.pipe != nil && !b.closed {
-		b.pipe.BreakWithError(errClosedBody)
-	}
-	b.closed = true
+	b.closeOnce.Do(func() {
+		if b.pipe != nil {
+			b.pipe.BreakWithError(errClosedBody)
+		}
+	})
 	return nil
 }
 
@@ -2354,7 +2482,6 @@
 	// immutable within a request:
 	stream *stream
 	req    *http.Request
-	body   *requestBody // to close at end of request, if DATA frames didn't
 	conn   *serverConn
 
 	// TODO: adjust buffer writing sizes based on server config, frame size updates from peer, etc
@@ -2379,7 +2506,15 @@
 
 type chunkWriter struct{ rws *responseWriterState }
 
-func (cw chunkWriter) Write(p []byte) (n int, err error) { return cw.rws.writeChunk(p) }
+func (cw chunkWriter) Write(p []byte) (n int, err error) {
+	n, err = cw.rws.writeChunk(p)
+	if err == errStreamClosed {
+		// If writing failed because the stream has been closed,
+		// return the reason it was closed.
+		err = cw.rws.stream.closeErr
+	}
+	return n, err
+}
 
 func (rws *responseWriterState) hasTrailers() bool { return len(rws.trailers) > 0 }
 
@@ -2418,6 +2553,10 @@
 		rws.writeHeader(200)
 	}
 
+	if rws.handlerDone {
+		rws.promoteUndeclaredTrailers()
+	}
+
 	isHeadResp := rws.req.Method == "HEAD"
 	if !rws.sentHeader {
 		rws.sentHeader = true
@@ -2489,10 +2628,6 @@
 		return 0, nil
 	}
 
-	if rws.handlerDone {
-		rws.promoteUndeclaredTrailers()
-	}
-
 	// only send trailers if they have actually been defined by the
 	// server handler.
 	hasNonemptyTrailers := rws.hasNonemptyTrailers()
@@ -2573,23 +2708,85 @@
 	}
 }
 
+func (w *responseWriter) SetReadDeadline(deadline time.Time) error {
+	st := w.rws.stream
+	if !deadline.IsZero() && deadline.Before(time.Now()) {
+		// If we're setting a deadline in the past, reset the stream immediately
+		// so writes after SetWriteDeadline returns will fail.
+		st.onReadTimeout()
+		return nil
+	}
+	w.rws.conn.sendServeMsg(func(sc *serverConn) {
+		if st.readDeadline != nil {
+			if !st.readDeadline.Stop() {
+				// Deadline already exceeded, or stream has been closed.
+				return
+			}
+		}
+		if deadline.IsZero() {
+			st.readDeadline = nil
+		} else if st.readDeadline == nil {
+			st.readDeadline = time.AfterFunc(deadline.Sub(time.Now()), st.onReadTimeout)
+		} else {
+			st.readDeadline.Reset(deadline.Sub(time.Now()))
+		}
+	})
+	return nil
+}
+
+func (w *responseWriter) SetWriteDeadline(deadline time.Time) error {
+	st := w.rws.stream
+	if !deadline.IsZero() && deadline.Before(time.Now()) {
+		// If we're setting a deadline in the past, reset the stream immediately
+		// so writes after SetWriteDeadline returns will fail.
+		st.onWriteTimeout()
+		return nil
+	}
+	w.rws.conn.sendServeMsg(func(sc *serverConn) {
+		if st.writeDeadline != nil {
+			if !st.writeDeadline.Stop() {
+				// Deadline already exceeded, or stream has been closed.
+				return
+			}
+		}
+		if deadline.IsZero() {
+			st.writeDeadline = nil
+		} else if st.writeDeadline == nil {
+			st.writeDeadline = time.AfterFunc(deadline.Sub(time.Now()), st.onWriteTimeout)
+		} else {
+			st.writeDeadline.Reset(deadline.Sub(time.Now()))
+		}
+	})
+	return nil
+}
+
 func (w *responseWriter) Flush() {
+	w.FlushError()
+}
+
+func (w *responseWriter) FlushError() error {
 	rws := w.rws
 	if rws == nil {
 		panic("Header called after Handler finished")
 	}
+	var err error
 	if rws.bw.Buffered() > 0 {
-		if err := rws.bw.Flush(); err != nil {
-			// Ignore the error. The frame writer already knows.
-			return
-		}
+		err = rws.bw.Flush()
 	} else {
 		// The bufio.Writer won't call chunkWriter.Write
 		// (writeChunk with zero bytes, so we have to do it
 		// ourselves to force the HTTP response header and/or
 		// final DATA frame (with END_STREAM) to be sent.
-		rws.writeChunk(nil)
+		_, err = chunkWriter{rws}.Write(nil)
+		if err == nil {
+			select {
+			case <-rws.stream.cw:
+				err = rws.stream.closeErr
+			default:
+			}
+		}
 	}
+	return err
 }
 
 func (w *responseWriter) CloseNotify() <-chan bool {
@@ -2628,8 +2825,7 @@
 	// Issue 22880: require valid WriteHeader status codes.
 	// For now we only enforce that it's three digits.
 	// In the future we might block things over 599 (600 and above aren't defined
-	// at http://httpwg.org/specs/rfc7231.html#status.codes)
-	// and we might block under 200 (once we have more mature 1xx support).
+	// at http://httpwg.org/specs/rfc7231.html#status.codes).
 	// But for now any three digits.
 	//
 	// We used to send "HTTP/1.1 000 0" on the wire in responses but there's
@@ -2650,13 +2846,41 @@
 }
 
 func (rws *responseWriterState) writeHeader(code int) {
-	if !rws.wroteHeader {
-		checkWriteHeaderCode(code)
-		rws.wroteHeader = true
-		rws.status = code
-		if len(rws.handlerHeader) > 0 {
-			rws.snapHeader = cloneHeader(rws.handlerHeader)
+	if rws.wroteHeader {
+		return
+	}
+
+	checkWriteHeaderCode(code)
+
+	// Handle informational headers
+	if code >= 100 && code <= 199 {
+		// Per RFC 8297 we must not clear the current header map
+		h := rws.handlerHeader
+
+		_, cl := h["Content-Length"]
+		_, te := h["Transfer-Encoding"]
+		if cl || te {
+			h = h.Clone()
+			h.Del("Content-Length")
+			h.Del("Transfer-Encoding")
 		}
+
+		if rws.conn.writeHeaders(rws.stream, &writeResHeaders{
+			streamID:    rws.stream.id,
+			httpResCode: code,
+			h:           h,
+			endStream:   rws.handlerDone && !rws.hasTrailers(),
+		}) != nil {
+			rws.dirty = true
+		}
+
+		return
+	}
+
+	rws.wroteHeader = true
+	rws.status = code
+	if len(rws.handlerHeader) > 0 {
+		rws.snapHeader = cloneHeader(rws.handlerHeader)
 	}
 }
 
@@ -2790,8 +3014,12 @@
 		// but PUSH_PROMISE requests cannot have a body.
 		// http://tools.ietf.org/html/rfc7540#section-8.2
 		// Also disallow Host, since the promised URL must be absolute.
-		switch strings.ToLower(k) {
-		case "content-length", "content-encoding", "trailer", "te", "expect", "host":
+		if asciiEqualFold(k, "content-length") ||
+			asciiEqualFold(k, "content-encoding") ||
+			asciiEqualFold(k, "trailer") ||
+			asciiEqualFold(k, "te") ||
+			asciiEqualFold(k, "expect") ||
+			asciiEqualFold(k, "host") {
 			return fmt.Errorf("promised request headers cannot include %q", k)
 		}
 	}
@@ -2983,3 +3211,31 @@
 	}
 	return false
 }
+
+func (sc *serverConn) countError(name string, err error) error {
+	if sc == nil || sc.srv == nil {
+		return err
+	}
+	f := sc.srv.CountError
+	if f == nil {
+		return err
+	}
+	var typ string
+	var code ErrCode
+	switch e := err.(type) {
+	case ConnectionError:
+		typ = "conn"
+		code = ErrCode(e)
+	case StreamError:
+		typ = "stream"
+		code = ErrCode(e.Code)
+	default:
+		return err
+	}
+	codeStr := errCodeName[code]
+	if codeStr == "" {
+		codeStr = strconv.Itoa(int(code))
+	}
+	f(fmt.Sprintf("%s_%s_%s", typ, codeStr, name))
+	return err
+}
diff --git a/vendor/golang.org/x/net/http2/transport.go b/vendor/golang.org/x/net/http2/transport.go
index 7688d72..ac90a26 100644
--- a/vendor/golang.org/x/net/http2/transport.go
+++ b/vendor/golang.org/x/net/http2/transport.go
@@ -16,7 +16,7 @@
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"io/fs"
 	"log"
 	"math"
 	mathrand "math/rand"
@@ -24,6 +24,7 @@
 	"net/http"
 	"net/http/httptrace"
 	"net/textproto"
+	"os"
 	"sort"
 	"strconv"
 	"strings"
@@ -46,11 +47,16 @@
 	// we buffer per stream.
 	transportDefaultStreamFlow = 4 << 20
 
-	// transportDefaultStreamMinRefresh is the minimum number of bytes we'll send
-	// a stream-level WINDOW_UPDATE for at a time.
-	transportDefaultStreamMinRefresh = 4 << 10
-
 	defaultUserAgent = "Go-http-client/2.0"
+
+	// initialMaxConcurrentStreams is a connections maxConcurrentStreams until
+	// it's received servers initial SETTINGS frame, which corresponds with the
+	// spec's minimum recommended value.
+	initialMaxConcurrentStreams = 100
+
+	// defaultMaxConcurrentStreams is a connections default maxConcurrentStreams
+	// if the server doesn't include one in its initial SETTINGS frame.
+	defaultMaxConcurrentStreams = 1000
 )
 
 // Transport is an HTTP/2 Transport.
@@ -58,13 +64,23 @@
 // A Transport internally caches connections to servers. It is safe
 // for concurrent use by multiple goroutines.
 type Transport struct {
-	// DialTLS specifies an optional dial function for creating
-	// TLS connections for requests.
+	// DialTLSContext specifies an optional dial function with context for
+	// creating TLS connections for requests.
 	//
-	// If DialTLS is nil, tls.Dial is used.
+	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
 	//
 	// If the returned net.Conn has a ConnectionState method like tls.Conn,
 	// it will be used to set http.Response.TLS.
+	DialTLSContext func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error)
+
+	// DialTLS specifies an optional dial function for creating
+	// TLS connections for requests.
+	//
+	// If DialTLSContext and DialTLS is nil, tls.Dial is used.
+	//
+	// Deprecated: Use DialTLSContext instead, which allows the transport
+	// to cancel dials as soon as they are no longer needed.
+	// If both are set, DialTLSContext takes priority.
 	DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error)
 
 	// TLSClientConfig specifies the TLS configuration to use with
@@ -98,6 +114,28 @@
 	// to mean no limit.
 	MaxHeaderListSize uint32
 
+	// MaxReadFrameSize is the http2 SETTINGS_MAX_FRAME_SIZE to send in the
+	// initial settings frame. It is the size in bytes of the largest frame
+	// payload that the sender is willing to receive. If 0, no setting is
+	// sent, and the value is provided by the peer, which should be 16384
+	// according to the spec:
+	// https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2.
+	// Values are bounded in the range 16k to 16M.
+	MaxReadFrameSize uint32
+
+	// MaxDecoderHeaderTableSize optionally specifies the http2
+	// SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It
+	// informs the remote endpoint of the maximum size of the header compression
+	// table used to decode header blocks, in octets. If zero, the default value
+	// of 4096 is used.
+	MaxDecoderHeaderTableSize uint32
+
+	// MaxEncoderHeaderTableSize optionally specifies an upper limit for the
+	// header compression table used for encoding request headers. Received
+	// SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero,
+	// the default value of 4096 is used.
+	MaxEncoderHeaderTableSize uint32
+
 	// StrictMaxConcurrentStreams controls whether the server's
 	// SETTINGS_MAX_CONCURRENT_STREAMS should be respected
 	// globally. If false, new TCP connections are created to the
@@ -121,6 +159,17 @@
 	// Defaults to 15s.
 	PingTimeout time.Duration
 
+	// WriteByteTimeout is the timeout after which the connection will be
+	// closed no data can be written to it. The timeout begins when data is
+	// available to write, and is extended whenever any bytes are written.
+	WriteByteTimeout time.Duration
+
+	// CountError, if non-nil, is called on HTTP/2 transport errors.
+	// It's intended to increment a metric for monitoring, such
+	// as an expvar or Prometheus metric.
+	// The errType consists of only ASCII word characters.
+	CountError func(errType string)
+
 	// t1, if non-nil, is the standard library Transport using
 	// this transport. Its settings are used (but not its
 	// RoundTrip method, etc).
@@ -140,6 +189,19 @@
 	return t.MaxHeaderListSize
 }
 
+func (t *Transport) maxFrameReadSize() uint32 {
+	if t.MaxReadFrameSize == 0 {
+		return 0 // use the default provided by the peer
+	}
+	if t.MaxReadFrameSize < minMaxFrameSize {
+		return minMaxFrameSize
+	}
+	if t.MaxReadFrameSize > maxFrameSize {
+		return maxFrameSize
+	}
+	return t.MaxReadFrameSize
+}
+
 func (t *Transport) disableCompression() bool {
 	return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
 }
@@ -227,11 +289,13 @@
 // ClientConn is the state of a single HTTP/2 client connection to an
 // HTTP/2 server.
 type ClientConn struct {
-	t         *Transport
-	tconn     net.Conn             // usually *tls.Conn, except specialized impls
-	tlsState  *tls.ConnectionState // nil only for specialized impls
-	reused    uint32               // whether conn is being reused; atomic
-	singleUse bool                 // whether being used for a single http.Request
+	t             *Transport
+	tconn         net.Conn // usually *tls.Conn, except specialized impls
+	tconnClosed   bool
+	tlsState      *tls.ConnectionState // nil only for specialized impls
+	reused        uint32               // whether conn is being reused; atomic
+	singleUse     bool                 // whether being used for a single http.Request
+	getConnCalled bool                 // used by clientConnPool
 
 	// readLoop goroutine fields:
 	readerDone chan struct{} // closed on error
@@ -242,89 +306,97 @@
 
 	mu              sync.Mutex // guards following
 	cond            *sync.Cond // hold mu; broadcast on flow/closed changes
-	flow            flow       // our conn-level flow control quota (cs.flow is per stream)
-	inflow          flow       // peer's conn-level flow control
+	flow            outflow    // our conn-level flow control quota (cs.outflow is per stream)
+	inflow          inflow     // peer's conn-level flow control
+	doNotReuse      bool       // whether conn is marked to not be reused for any future requests
 	closing         bool
 	closed          bool
+	seenSettings    bool                     // true if we've seen a settings frame, false otherwise
 	wantSettingsAck bool                     // we sent a SETTINGS frame and haven't heard back
 	goAway          *GoAwayFrame             // if non-nil, the GoAwayFrame we received
 	goAwayDebug     string                   // goAway frame's debug data, retained as a string
 	streams         map[uint32]*clientStream // client-initiated
+	streamsReserved int                      // incr by ReserveNewRequest; decr on RoundTrip
 	nextStreamID    uint32
 	pendingRequests int                       // requests blocked and waiting to be sent because len(streams) == maxConcurrentStreams
 	pings           map[[8]byte]chan struct{} // in flight ping data to notification channel
-	bw              *bufio.Writer
 	br              *bufio.Reader
-	fr              *Framer
 	lastActive      time.Time
 	lastIdle        time.Time // time last idle
-	// Settings from peer: (also guarded by mu)
-	maxFrameSize          uint32
-	maxConcurrentStreams  uint32
-	peerMaxHeaderListSize uint64
-	initialWindowSize     uint32
+	// Settings from peer: (also guarded by wmu)
+	maxFrameSize           uint32
+	maxConcurrentStreams   uint32
+	peerMaxHeaderListSize  uint64
+	peerMaxHeaderTableSize uint32
+	initialWindowSize      uint32
 
-	hbuf    bytes.Buffer // HPACK encoder writes into this
-	henc    *hpack.Encoder
-	freeBuf [][]byte
+	// reqHeaderMu is a 1-element semaphore channel controlling access to sending new requests.
+	// Write to reqHeaderMu to lock it, read from it to unlock.
+	// Lock reqmu BEFORE mu or wmu.
+	reqHeaderMu chan struct{}
 
-	wmu  sync.Mutex // held while writing; acquire AFTER mu if holding both
-	werr error      // first write error that has occurred
+	// wmu is held while writing.
+	// Acquire BEFORE mu when holding both, to avoid blocking mu on network writes.
+	// Only acquire both at the same time when changing peer settings.
+	wmu  sync.Mutex
+	bw   *bufio.Writer
+	fr   *Framer
+	werr error        // first write error that has occurred
+	hbuf bytes.Buffer // HPACK encoder writes into this
+	henc *hpack.Encoder
 }
 
 // clientStream is the state for a single HTTP/2 stream. One of these
 // is created for each Transport.RoundTrip call.
 type clientStream struct {
-	cc            *ClientConn
-	req           *http.Request
+	cc *ClientConn
+
+	// Fields of Request that we may access even after the response body is closed.
+	ctx       context.Context
+	reqCancel <-chan struct{}
+
 	trace         *httptrace.ClientTrace // or nil
 	ID            uint32
-	resc          chan resAndError
 	bufPipe       pipe // buffered pipe with the flow-controlled response payload
-	startedWrite  bool // started request body write; guarded by cc.mu
 	requestedGzip bool
-	on100         func() // optional code to run if get a 100 continue response
+	isHead        bool
 
-	flow        flow  // guarded by cc.mu
-	inflow      flow  // guarded by cc.mu
-	bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read
-	readErr     error // sticky read error; owned by transportResponseBody.Read
-	stopReqBody error // if non-nil, stop writing req body; guarded by cc.mu
-	didReset    bool  // whether we sent a RST_STREAM to the server; guarded by cc.mu
+	abortOnce sync.Once
+	abort     chan struct{} // closed to signal stream should end immediately
+	abortErr  error         // set if abort is closed
 
-	peerReset chan struct{} // closed on peer reset
-	resetErr  error         // populated before peerReset is closed
+	peerClosed chan struct{} // closed when the peer sends an END_STREAM flag
+	donec      chan struct{} // closed after the stream is in the closed state
+	on100      chan struct{} // buffered; written to if a 100 is received
 
-	done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu
+	respHeaderRecv chan struct{}  // closed when headers are received
+	res            *http.Response // set if respHeaderRecv is closed
+
+	flow        outflow // guarded by cc.mu
+	inflow      inflow  // guarded by cc.mu
+	bytesRemain int64   // -1 means unknown; owned by transportResponseBody.Read
+	readErr     error   // sticky read error; owned by transportResponseBody.Read
+
+	reqBody              io.ReadCloser
+	reqBodyContentLength int64         // -1 means unknown
+	reqBodyClosed        chan struct{} // guarded by cc.mu; non-nil on Close, closed when done
+
+	// owned by writeRequest:
+	sentEndStream bool // sent an END_STREAM flag to the peer
+	sentHeaders   bool
 
 	// owned by clientConnReadLoop:
 	firstByte    bool  // got the first response byte
 	pastHeaders  bool  // got first MetaHeadersFrame (actual headers)
 	pastTrailers bool  // got optional second MetaHeadersFrame (trailers)
 	num1xx       uint8 // number of 1xx responses seen
+	readClosed   bool  // peer sent an END_STREAM flag
+	readAborted  bool  // read loop reset the stream
 
 	trailer    http.Header  // accumulated trailers
 	resTrailer *http.Header // client's Response.Trailer
 }
 
-// awaitRequestCancel waits for the user to cancel a request or for the done
-// channel to be signaled. A non-nil error is returned only if the request was
-// canceled.
-func awaitRequestCancel(req *http.Request, done <-chan struct{}) error {
-	ctx := req.Context()
-	if req.Cancel == nil && ctx.Done() == nil {
-		return nil
-	}
-	select {
-	case <-req.Cancel:
-		return errRequestCanceled
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-done:
-		return nil
-	}
-}
-
 var got1xxFuncForTests func(int, textproto.MIMEHeader) error
 
 // get1xxTraceFunc returns the value of request's httptrace.ClientTrace.Got1xxResponse func,
@@ -336,73 +408,75 @@
 	return traceGot1xxResponseFunc(cs.trace)
 }
 
-// awaitRequestCancel waits for the user to cancel a request, its context to
-// expire, or for the request to be done (any way it might be removed from the
-// cc.streams map: peer reset, successful completion, TCP connection breakage,
-// etc). If the request is canceled, then cs will be canceled and closed.
-func (cs *clientStream) awaitRequestCancel(req *http.Request) {
-	if err := awaitRequestCancel(req, cs.done); err != nil {
-		cs.cancelStream()
-		cs.bufPipe.CloseWithError(err)
+func (cs *clientStream) abortStream(err error) {
+	cs.cc.mu.Lock()
+	defer cs.cc.mu.Unlock()
+	cs.abortStreamLocked(err)
+}
+
+func (cs *clientStream) abortStreamLocked(err error) {
+	cs.abortOnce.Do(func() {
+		cs.abortErr = err
+		close(cs.abort)
+	})
+	if cs.reqBody != nil {
+		cs.closeReqBodyLocked()
+	}
+	// TODO(dneil): Clean up tests where cs.cc.cond is nil.
+	if cs.cc.cond != nil {
+		// Wake up writeRequestBody if it is waiting on flow control.
+		cs.cc.cond.Broadcast()
 	}
 }
 
-func (cs *clientStream) cancelStream() {
-	cc := cs.cc
-	cc.mu.Lock()
-	didReset := cs.didReset
-	cs.didReset = true
-	cc.mu.Unlock()
-
-	if !didReset {
-		cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
-		cc.forgetStreamID(cs.ID)
-	}
-}
-
-// checkResetOrDone reports any error sent in a RST_STREAM frame by the
-// server, or errStreamClosed if the stream is complete.
-func (cs *clientStream) checkResetOrDone() error {
-	select {
-	case <-cs.peerReset:
-		return cs.resetErr
-	case <-cs.done:
-		return errStreamClosed
-	default:
-		return nil
-	}
-}
-
-func (cs *clientStream) getStartedWrite() bool {
+func (cs *clientStream) abortRequestBodyWrite() {
 	cc := cs.cc
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
-	return cs.startedWrite
+	if cs.reqBody != nil && cs.reqBodyClosed == nil {
+		cs.closeReqBodyLocked()
+		cc.cond.Broadcast()
+	}
 }
 
-func (cs *clientStream) abortRequestBodyWrite(err error) {
-	if err == nil {
-		panic("nil error")
+func (cs *clientStream) closeReqBodyLocked() {
+	if cs.reqBodyClosed != nil {
+		return
 	}
-	cc := cs.cc
-	cc.mu.Lock()
-	cs.stopReqBody = err
-	cc.cond.Broadcast()
-	cc.mu.Unlock()
+	cs.reqBodyClosed = make(chan struct{})
+	reqBodyClosed := cs.reqBodyClosed
+	go func() {
+		cs.reqBody.Close()
+		close(reqBodyClosed)
+	}()
 }
 
 type stickyErrWriter struct {
-	w   io.Writer
-	err *error
+	conn    net.Conn
+	timeout time.Duration
+	err     *error
 }
 
 func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	if *sew.err != nil {
 		return 0, *sew.err
 	}
-	n, err = sew.w.Write(p)
-	*sew.err = err
-	return
+	for {
+		if sew.timeout != 0 {
+			sew.conn.SetWriteDeadline(time.Now().Add(sew.timeout))
+		}
+		nn, err := sew.conn.Write(p[n:])
+		n += nn
+		if n < len(p) && nn > 0 && errors.Is(err, os.ErrDeadlineExceeded) {
+			// Keep extending the deadline so long as we're making progress.
+			continue
+		}
+		if sew.timeout != 0 {
+			sew.conn.SetWriteDeadline(time.Time{})
+		}
+		*sew.err = err
+		return n, err
+	}
 }
 
 // noCachedConnError is the concrete type of ErrNoCachedConn, which
@@ -460,6 +534,15 @@
 	return net.JoinHostPort(host, port)
 }
 
+var retryBackoffHook func(time.Duration) *time.Timer
+
+func backoffNewTimer(d time.Duration) *time.Timer {
+	if retryBackoffHook != nil {
+		return retryBackoffHook(d)
+	}
+	return time.NewTimer(d)
+}
+
 // RoundTripOpt is like RoundTrip, but takes options.
 func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
 	if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) {
@@ -475,20 +558,26 @@
 		}
 		reused := !atomic.CompareAndSwapUint32(&cc.reused, 0, 1)
 		traceGotConn(req, cc, reused)
-		res, gotErrAfterReqBodyWrite, err := cc.roundTrip(req)
+		res, err := cc.RoundTrip(req)
 		if err != nil && retry <= 6 {
-			if req, err = shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil {
+			roundTripErr := err
+			if req, err = shouldRetryRequest(req, err); err == nil {
 				// After the first retry, do exponential backoff with 10% jitter.
 				if retry == 0 {
+					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
 					continue
 				}
 				backoff := float64(uint(1) << (uint(retry) - 1))
 				backoff += backoff * (0.1 * mathrand.Float64())
+				d := time.Second * time.Duration(backoff)
+				timer := backoffNewTimer(d)
 				select {
-				case <-time.After(time.Second * time.Duration(backoff)):
+				case <-timer.C:
+					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
 					continue
 				case <-req.Context().Done():
-					return nil, req.Context().Err()
+					timer.Stop()
+					err = req.Context().Err()
 				}
 			}
 		}
@@ -519,7 +608,7 @@
 // response headers. It is always called with a non-nil error.
 // It returns either a request to retry (either the same request, or a
 // modified clone), or an error if the request can't be replayed.
-func shouldRetryRequest(req *http.Request, err error, afterBodyWrite bool) (*http.Request, error) {
+func shouldRetryRequest(req *http.Request, err error) (*http.Request, error) {
 	if !canRetryError(err) {
 		return nil, err
 	}
@@ -532,7 +621,6 @@
 	// If the request body can be reset back to its original
 	// state via the optional req.GetBody, do that.
 	if req.GetBody != nil {
-		// TODO: consider a req.Body.Close here? or audit that all caller paths do?
 		body, err := req.GetBody()
 		if err != nil {
 			return nil, err
@@ -544,10 +632,8 @@
 
 	// The Request.Body can't reset back to the beginning, but we
 	// don't seem to have started to read from it yet, so reuse
-	// the request directly. The "afterBodyWrite" means the
-	// bodyWrite process has started, which becomes true before
-	// the first Read.
-	if !afterBodyWrite {
+	// the request directly.
+	if err == errClientConnUnusable {
 		return req, nil
 	}
 
@@ -559,17 +645,21 @@
 		return true
 	}
 	if se, ok := err.(StreamError); ok {
+		if se.Code == ErrCodeProtocol && se.Cause == errFromPeer {
+			// See golang/go#47635, golang/go#42777
+			return true
+		}
 		return se.Code == ErrCodeRefusedStream
 	}
 	return false
 }
 
-func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
+func (t *Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*ClientConn, error) {
 	host, _, err := net.SplitHostPort(addr)
 	if err != nil {
 		return nil, err
 	}
-	tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host))
+	tconn, err := t.dialTLS(ctx, "tcp", addr, t.newTLSConfig(host))
 	if err != nil {
 		return nil, err
 	}
@@ -590,34 +680,25 @@
 	return cfg
 }
 
-func (t *Transport) dialTLS() func(string, string, *tls.Config) (net.Conn, error) {
-	if t.DialTLS != nil {
-		return t.DialTLS
+func (t *Transport) dialTLS(ctx context.Context, network, addr string, tlsCfg *tls.Config) (net.Conn, error) {
+	if t.DialTLSContext != nil {
+		return t.DialTLSContext(ctx, network, addr, tlsCfg)
+	} else if t.DialTLS != nil {
+		return t.DialTLS(network, addr, tlsCfg)
 	}
-	return t.dialTLSDefault
-}
 
-func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) {
-	cn, err := tls.Dial(network, addr, cfg)
+	tlsCn, err := t.dialTLSWithContext(ctx, network, addr, tlsCfg)
 	if err != nil {
 		return nil, err
 	}
-	if err := cn.Handshake(); err != nil {
-		return nil, err
-	}
-	if !cfg.InsecureSkipVerify {
-		if err := cn.VerifyHostname(cfg.ServerName); err != nil {
-			return nil, err
-		}
-	}
-	state := cn.ConnectionState()
+	state := tlsCn.ConnectionState()
 	if p := state.NegotiatedProtocol; p != NextProtoTLS {
 		return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
 	}
 	if !state.NegotiatedProtocolIsMutual {
 		return nil, errors.New("http2: could not negotiate protocol mutually")
 	}
-	return cn, nil
+	return tlsCn, nil
 }
 
 // disableKeepAlives reports whether connections should be closed as
@@ -633,6 +714,20 @@
 	return t.t1.ExpectContinueTimeout
 }
 
+func (t *Transport) maxDecoderHeaderTableSize() uint32 {
+	if v := t.MaxDecoderHeaderTableSize; v > 0 {
+		return v
+	}
+	return initialHeaderTableSize
+}
+
+func (t *Transport) maxEncoderHeaderTableSize() uint32 {
+	if v := t.MaxEncoderHeaderTableSize; v > 0 {
+		return v
+	}
+	return initialHeaderTableSize
+}
+
 func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
 	return t.newClientConn(c, t.disableKeepAlives())
 }
@@ -643,14 +738,15 @@
 		tconn:                 c,
 		readerDone:            make(chan struct{}),
 		nextStreamID:          1,
-		maxFrameSize:          16 << 10,           // spec default
-		initialWindowSize:     65535,              // spec default
-		maxConcurrentStreams:  1000,               // "infinite", per spec. 1000 seems good enough.
-		peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead.
+		maxFrameSize:          16 << 10,                    // spec default
+		initialWindowSize:     65535,                       // spec default
+		maxConcurrentStreams:  initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.
+		peerMaxHeaderListSize: 0xffffffffffffffff,          // "infinite", per spec. Use 2^64-1 instead.
 		streams:               make(map[uint32]*clientStream),
 		singleUse:             singleUse,
 		wantSettingsAck:       true,
 		pings:                 make(map[[8]byte]chan struct{}),
+		reqHeaderMu:           make(chan struct{}, 1),
 	}
 	if d := t.idleConnTimeout(); d != 0 {
 		cc.idleTimeout = d
@@ -665,15 +761,26 @@
 
 	// TODO: adjust this writer size to account for frame size +
 	// MTU + crypto/tls record padding.
-	cc.bw = bufio.NewWriter(stickyErrWriter{c, &cc.werr})
+	cc.bw = bufio.NewWriter(stickyErrWriter{
+		conn:    c,
+		timeout: t.WriteByteTimeout,
+		err:     &cc.werr,
+	})
 	cc.br = bufio.NewReader(c)
 	cc.fr = NewFramer(cc.bw, cc.br)
-	cc.fr.ReadMetaHeaders = hpack.NewDecoder(initialHeaderTableSize, nil)
+	if t.maxFrameReadSize() != 0 {
+		cc.fr.SetMaxReadFrameSize(t.maxFrameReadSize())
+	}
+	if t.CountError != nil {
+		cc.fr.countError = t.CountError
+	}
+	maxHeaderTableSize := t.maxDecoderHeaderTableSize()
+	cc.fr.ReadMetaHeaders = hpack.NewDecoder(maxHeaderTableSize, nil)
 	cc.fr.MaxHeaderListSize = t.maxHeaderListSize()
 
-	// TODO: SetMaxDynamicTableSize, SetMaxDynamicTableSizeLimit on
-	// henc in response to SETTINGS frames?
 	cc.henc = hpack.NewEncoder(&cc.hbuf)
+	cc.henc.SetMaxDynamicTableSizeLimit(t.maxEncoderHeaderTableSize())
+	cc.peerMaxHeaderTableSize = initialHeaderTableSize
 
 	if t.AllowHTTP {
 		cc.nextStreamID = 3
@@ -688,14 +795,20 @@
 		{ID: SettingEnablePush, Val: 0},
 		{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
 	}
+	if max := t.maxFrameReadSize(); max != 0 {
+		initialSettings = append(initialSettings, Setting{ID: SettingMaxFrameSize, Val: max})
+	}
 	if max := t.maxHeaderListSize(); max != 0 {
 		initialSettings = append(initialSettings, Setting{ID: SettingMaxHeaderListSize, Val: max})
 	}
+	if maxHeaderTableSize != initialHeaderTableSize {
+		initialSettings = append(initialSettings, Setting{ID: SettingHeaderTableSize, Val: maxHeaderTableSize})
+	}
 
 	cc.bw.Write(clientPreface)
 	cc.fr.WriteSettings(initialSettings...)
 	cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow)
-	cc.inflow.add(transportDefaultConnFlow + initialWindowSize)
+	cc.inflow.init(transportDefaultConnFlow + initialWindowSize)
 	cc.bw.Flush()
 	if cc.werr != nil {
 		cc.Close()
@@ -712,14 +825,23 @@
 	// trigger the healthCheck again if there is no frame received.
 	ctx, cancel := context.WithTimeout(context.Background(), pingTimeout)
 	defer cancel()
+	cc.vlogf("http2: Transport sending health check")
 	err := cc.Ping(ctx)
 	if err != nil {
+		cc.vlogf("http2: Transport health check failure: %v", err)
 		cc.closeForLostPing()
-		cc.t.connPool().MarkDead(cc)
-		return
+	} else {
+		cc.vlogf("http2: Transport health check success")
 	}
 }
 
+// SetDoNotReuse marks cc as not reusable for future HTTP requests.
+func (cc *ClientConn) SetDoNotReuse() {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	cc.doNotReuse = true
+}
+
 func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
@@ -737,27 +859,94 @@
 	last := f.LastStreamID
 	for streamID, cs := range cc.streams {
 		if streamID > last {
-			select {
-			case cs.resc <- resAndError{err: errClientConnGotGoAway}:
-			default:
-			}
+			cs.abortStreamLocked(errClientConnGotGoAway)
 		}
 	}
 }
 
 // CanTakeNewRequest reports whether the connection can take a new request,
 // meaning it has not been closed or received or sent a GOAWAY.
+//
+// If the caller is going to immediately make a new request on this
+// connection, use ReserveNewRequest instead.
 func (cc *ClientConn) CanTakeNewRequest() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	return cc.canTakeNewRequestLocked()
 }
 
+// ReserveNewRequest is like CanTakeNewRequest but also reserves a
+// concurrent stream in cc. The reservation is decremented on the
+// next call to RoundTrip.
+func (cc *ClientConn) ReserveNewRequest() bool {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	if st := cc.idleStateLocked(); !st.canTakeNewRequest {
+		return false
+	}
+	cc.streamsReserved++
+	return true
+}
+
+// ClientConnState describes the state of a ClientConn.
+type ClientConnState struct {
+	// Closed is whether the connection is closed.
+	Closed bool
+
+	// Closing is whether the connection is in the process of
+	// closing. It may be closing due to shutdown, being a
+	// single-use connection, being marked as DoNotReuse, or
+	// having received a GOAWAY frame.
+	Closing bool
+
+	// StreamsActive is how many streams are active.
+	StreamsActive int
+
+	// StreamsReserved is how many streams have been reserved via
+	// ClientConn.ReserveNewRequest.
+	StreamsReserved int
+
+	// StreamsPending is how many requests have been sent in excess
+	// of the peer's advertised MaxConcurrentStreams setting and
+	// are waiting for other streams to complete.
+	StreamsPending int
+
+	// MaxConcurrentStreams is how many concurrent streams the
+	// peer advertised as acceptable. Zero means no SETTINGS
+	// frame has been received yet.
+	MaxConcurrentStreams uint32
+
+	// LastIdle, if non-zero, is when the connection last
+	// transitioned to idle state.
+	LastIdle time.Time
+}
+
+// State returns a snapshot of cc's state.
+func (cc *ClientConn) State() ClientConnState {
+	cc.wmu.Lock()
+	maxConcurrent := cc.maxConcurrentStreams
+	if !cc.seenSettings {
+		maxConcurrent = 0
+	}
+	cc.wmu.Unlock()
+
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	return ClientConnState{
+		Closed:               cc.closed,
+		Closing:              cc.closing || cc.singleUse || cc.doNotReuse || cc.goAway != nil,
+		StreamsActive:        len(cc.streams),
+		StreamsReserved:      cc.streamsReserved,
+		StreamsPending:       cc.pendingRequests,
+		LastIdle:             cc.lastIdle,
+		MaxConcurrentStreams: maxConcurrent,
+	}
+}
+
 // clientConnIdleState describes the suitability of a client
 // connection to initiate a new RoundTrip request.
 type clientConnIdleState struct {
 	canTakeNewRequest bool
-	freshConn         bool // whether it's unused by any previous request
 }
 
 func (cc *ClientConn) idleState() clientConnIdleState {
@@ -778,13 +967,13 @@
 		// writing it.
 		maxConcurrentOkay = true
 	} else {
-		maxConcurrentOkay = int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams)
+		maxConcurrentOkay = int64(len(cc.streams)+cc.streamsReserved+1) <= int64(cc.maxConcurrentStreams)
 	}
 
 	st.canTakeNewRequest = cc.goAway == nil && !cc.closed && !cc.closing && maxConcurrentOkay &&
+		!cc.doNotReuse &&
 		int64(cc.nextStreamID)+2*int64(cc.pendingRequests) < math.MaxInt32 &&
 		!cc.tooIdleLocked()
-	st.freshConn = cc.nextStreamID == 1 && st.canTakeNewRequest
 	return
 }
 
@@ -813,9 +1002,27 @@
 	cc.closeIfIdle()
 }
 
+func (cc *ClientConn) closeConn() {
+	t := time.AfterFunc(250*time.Millisecond, cc.forceCloseConn)
+	defer t.Stop()
+	cc.tconn.Close()
+}
+
+// A tls.Conn.Close can hang for a long time if the peer is unresponsive.
+// Try to shut it down more aggressively.
+func (cc *ClientConn) forceCloseConn() {
+	tc, ok := cc.tconn.(*tls.Conn)
+	if !ok {
+		return
+	}
+	if nc := tlsUnderlyingConn(tc); nc != nil {
+		nc.Close()
+	}
+}
+
 func (cc *ClientConn) closeIfIdle() {
 	cc.mu.Lock()
-	if len(cc.streams) > 0 {
+	if len(cc.streams) > 0 || cc.streamsReserved > 0 {
 		cc.mu.Unlock()
 		return
 	}
@@ -827,18 +1034,24 @@
 	if VerboseLogs {
 		cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, nextID-2)
 	}
-	cc.tconn.Close()
+	cc.closeConn()
+}
+
+func (cc *ClientConn) isDoNotReuseAndIdle() bool {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	return cc.doNotReuse && len(cc.streams) == 0
 }
 
 var shutdownEnterWaitStateHook = func() {}
 
-// Shutdown gracefully close the client connection, waiting for running streams to complete.
+// Shutdown gracefully closes the client connection, waiting for running streams to complete.
 func (cc *ClientConn) Shutdown(ctx context.Context) error {
 	if err := cc.sendGoAway(); err != nil {
 		return err
 	}
 	// Wait for all in-flight streams to complete or connection to close
-	done := make(chan error, 1)
+	done := make(chan struct{})
 	cancelled := false // guarded by cc.mu
 	go func() {
 		cc.mu.Lock()
@@ -846,7 +1059,7 @@
 		for {
 			if len(cc.streams) == 0 || cc.closed {
 				cc.closed = true
-				done <- cc.tconn.Close()
+				close(done)
 				break
 			}
 			if cancelled {
@@ -857,8 +1070,9 @@
 	}()
 	shutdownEnterWaitStateHook()
 	select {
-	case err := <-done:
-		return err
+	case <-done:
+		cc.closeConn()
+		return nil
 	case <-ctx.Done():
 		cc.mu.Lock()
 		// Free the goroutine above
@@ -871,15 +1085,18 @@
 
 func (cc *ClientConn) sendGoAway() error {
 	cc.mu.Lock()
-	defer cc.mu.Unlock()
-	cc.wmu.Lock()
-	defer cc.wmu.Unlock()
-	if cc.closing {
+	closing := cc.closing
+	cc.closing = true
+	maxStreamID := cc.nextStreamID
+	cc.mu.Unlock()
+	if closing {
 		// GOAWAY sent already
 		return nil
 	}
+
+	cc.wmu.Lock()
+	defer cc.wmu.Unlock()
 	// Send a graceful shutdown frame to server
-	maxStreamID := cc.nextStreamID
 	if err := cc.fr.WriteGoAway(maxStreamID, ErrCodeNo, nil); err != nil {
 		return err
 	}
@@ -887,26 +1104,20 @@
 		return err
 	}
 	// Prevent new requests
-	cc.closing = true
 	return nil
 }
 
 // closes the client connection immediately. In-flight requests are interrupted.
 // err is sent to streams.
-func (cc *ClientConn) closeForError(err error) error {
+func (cc *ClientConn) closeForError(err error) {
 	cc.mu.Lock()
-	defer cc.cond.Broadcast()
-	defer cc.mu.Unlock()
-	for id, cs := range cc.streams {
-		select {
-		case cs.resc <- resAndError{err: err}:
-		default:
-		}
-		cs.bufPipe.CloseWithError(err)
-		delete(cc.streams, id)
-	}
 	cc.closed = true
-	return cc.tconn.Close()
+	for _, cs := range cc.streams {
+		cs.abortStreamLocked(err)
+	}
+	cc.cond.Broadcast()
+	cc.mu.Unlock()
+	cc.closeConn()
 }
 
 // Close closes the client connection immediately.
@@ -914,53 +1125,17 @@
 // In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead.
 func (cc *ClientConn) Close() error {
 	err := errors.New("http2: client connection force closed via ClientConn.Close")
-	return cc.closeForError(err)
+	cc.closeForError(err)
+	return nil
 }
 
 // closes the client connection immediately. In-flight requests are interrupted.
-func (cc *ClientConn) closeForLostPing() error {
+func (cc *ClientConn) closeForLostPing() {
 	err := errors.New("http2: client connection lost")
-	return cc.closeForError(err)
-}
-
-const maxAllocFrameSize = 512 << 10
-
-// frameBuffer returns a scratch buffer suitable for writing DATA frames.
-// They're capped at the min of the peer's max frame size or 512KB
-// (kinda arbitrarily), but definitely capped so we don't allocate 4GB
-// bufers.
-func (cc *ClientConn) frameScratchBuffer() []byte {
-	cc.mu.Lock()
-	size := cc.maxFrameSize
-	if size > maxAllocFrameSize {
-		size = maxAllocFrameSize
+	if f := cc.t.CountError; f != nil {
+		f("conn_close_lost_ping")
 	}
-	for i, buf := range cc.freeBuf {
-		if len(buf) >= int(size) {
-			cc.freeBuf[i] = nil
-			cc.mu.Unlock()
-			return buf[:size]
-		}
-	}
-	cc.mu.Unlock()
-	return make([]byte, size)
-}
-
-func (cc *ClientConn) putFrameScratchBuffer(buf []byte) {
-	cc.mu.Lock()
-	defer cc.mu.Unlock()
-	const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
-	if len(cc.freeBuf) < maxBufs {
-		cc.freeBuf = append(cc.freeBuf, buf)
-		return
-	}
-	for i, old := range cc.freeBuf {
-		if old == nil {
-			cc.freeBuf[i] = buf
-			return
-		}
-	}
-	// forget about it.
+	cc.closeForError(err)
 }
 
 // errRequestCanceled is a copy of net/http's errRequestCanceled because it's not
@@ -970,7 +1145,7 @@
 func commaSeparatedTrailers(req *http.Request) (string, error) {
 	keys := make([]string, 0, len(req.Trailer))
 	for k := range req.Trailer {
-		k = http.CanonicalHeaderKey(k)
+		k = canonicalHeader(k)
 		switch k {
 		case "Transfer-Encoding", "Trailer", "Content-Length":
 			return "", fmt.Errorf("invalid Trailer key %q", k)
@@ -1005,7 +1180,7 @@
 	if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") {
 		return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv)
 	}
-	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !strings.EqualFold(vv[0], "close") && !strings.EqualFold(vv[0], "keep-alive")) {
+	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !asciiEqualFold(vv[0], "close") && !asciiEqualFold(vv[0], "keep-alive")) {
 		return fmt.Errorf("http2: invalid Connection request header: %q", vv)
 	}
 	return nil
@@ -1024,41 +1199,176 @@
 	return -1
 }
 
-func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
-	resp, _, err := cc.roundTrip(req)
-	return resp, err
+func (cc *ClientConn) decrStreamReservations() {
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	cc.decrStreamReservationsLocked()
 }
 
-func (cc *ClientConn) roundTrip(req *http.Request) (res *http.Response, gotErrAfterReqBodyWrite bool, err error) {
-	if err := checkConnHeaders(req); err != nil {
-		return nil, false, err
+func (cc *ClientConn) decrStreamReservationsLocked() {
+	if cc.streamsReserved > 0 {
+		cc.streamsReserved--
 	}
+}
+
+func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
+	ctx := req.Context()
+	cs := &clientStream{
+		cc:                   cc,
+		ctx:                  ctx,
+		reqCancel:            req.Cancel,
+		isHead:               req.Method == "HEAD",
+		reqBody:              req.Body,
+		reqBodyContentLength: actualContentLength(req),
+		trace:                httptrace.ContextClientTrace(ctx),
+		peerClosed:           make(chan struct{}),
+		abort:                make(chan struct{}),
+		respHeaderRecv:       make(chan struct{}),
+		donec:                make(chan struct{}),
+	}
+	go cs.doRequest(req)
+
+	waitDone := func() error {
+		select {
+		case <-cs.donec:
+			return nil
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-cs.reqCancel:
+			return errRequestCanceled
+		}
+	}
+
+	handleResponseHeaders := func() (*http.Response, error) {
+		res := cs.res
+		if res.StatusCode > 299 {
+			// On error or status code 3xx, 4xx, 5xx, etc abort any
+			// ongoing write, assuming that the server doesn't care
+			// about our request body. If the server replied with 1xx or
+			// 2xx, however, then assume the server DOES potentially
+			// want our body (e.g. full-duplex streaming:
+			// golang.org/issue/13444). If it turns out the server
+			// doesn't, they'll RST_STREAM us soon enough. This is a
+			// heuristic to avoid adding knobs to Transport. Hopefully
+			// we can keep it.
+			cs.abortRequestBodyWrite()
+		}
+		res.Request = req
+		res.TLS = cc.tlsState
+		if res.Body == noBody && actualContentLength(req) == 0 {
+			// If there isn't a request or response body still being
+			// written, then wait for the stream to be closed before
+			// RoundTrip returns.
+			if err := waitDone(); err != nil {
+				return nil, err
+			}
+		}
+		return res, nil
+	}
+
+	cancelRequest := func(cs *clientStream, err error) error {
+		cs.cc.mu.Lock()
+		defer cs.cc.mu.Unlock()
+		cs.abortStreamLocked(err)
+		if cs.ID != 0 {
+			// This request may have failed because of a problem with the connection,
+			// or for some unrelated reason. (For example, the user might have canceled
+			// the request without waiting for a response.) Mark the connection as
+			// not reusable, since trying to reuse a dead connection is worse than
+			// unnecessarily creating a new one.
+			//
+			// If cs.ID is 0, then the request was never allocated a stream ID and
+			// whatever went wrong was unrelated to the connection. We might have
+			// timed out waiting for a stream slot when StrictMaxConcurrentStreams
+			// is set, for example, in which case retrying on a different connection
+			// will not help.
+			cs.cc.doNotReuse = true
+		}
+		return err
+	}
+
+	for {
+		select {
+		case <-cs.respHeaderRecv:
+			return handleResponseHeaders()
+		case <-cs.abort:
+			select {
+			case <-cs.respHeaderRecv:
+				// If both cs.respHeaderRecv and cs.abort are signaling,
+				// pick respHeaderRecv. The server probably wrote the
+				// response and immediately reset the stream.
+				// golang.org/issue/49645
+				return handleResponseHeaders()
+			default:
+				waitDone()
+				return nil, cancelRequest(cs, cs.abortErr)
+			}
+		case <-ctx.Done():
+			return nil, cancelRequest(cs, ctx.Err())
+		case <-cs.reqCancel:
+			return nil, cancelRequest(cs, errRequestCanceled)
+		}
+	}
+}
+
+// doRequest runs for the duration of the request lifetime.
+//
+// It sends the request and performs post-request cleanup (closing Request.Body, etc.).
+func (cs *clientStream) doRequest(req *http.Request) {
+	err := cs.writeRequest(req)
+	cs.cleanupWriteRequest(err)
+}
+
+// writeRequest sends a request.
+//
+// It returns nil after the request is written, the response read,
+// and the request stream is half-closed by the peer.
+//
+// It returns non-nil if the request ends otherwise.
+// If the returned error is StreamError, the error Code may be used in resetting the stream.
+func (cs *clientStream) writeRequest(req *http.Request) (err error) {
+	cc := cs.cc
+	ctx := cs.ctx
+
+	if err := checkConnHeaders(req); err != nil {
+		return err
+	}
+
+	// Acquire the new-request lock by writing to reqHeaderMu.
+	// This lock guards the critical section covering allocating a new stream ID
+	// (requires mu) and creating the stream (requires wmu).
+	if cc.reqHeaderMu == nil {
+		panic("RoundTrip on uninitialized ClientConn") // for tests
+	}
+	select {
+	case cc.reqHeaderMu <- struct{}{}:
+	case <-cs.reqCancel:
+		return errRequestCanceled
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+
+	cc.mu.Lock()
 	if cc.idleTimer != nil {
 		cc.idleTimer.Stop()
 	}
-
-	trailers, err := commaSeparatedTrailers(req)
-	if err != nil {
-		return nil, false, err
-	}
-	hasTrailers := trailers != ""
-
-	cc.mu.Lock()
-	if err := cc.awaitOpenSlotForRequest(req); err != nil {
+	cc.decrStreamReservationsLocked()
+	if err := cc.awaitOpenSlotForStreamLocked(cs); err != nil {
 		cc.mu.Unlock()
-		return nil, false, err
+		<-cc.reqHeaderMu
+		return err
 	}
-
-	body := req.Body
-	contentLen := actualContentLength(req)
-	hasBody := contentLen != 0
+	cc.addStreamLocked(cs) // assigns stream ID
+	if isConnectionCloseRequest(req) {
+		cc.doNotReuse = true
+	}
+	cc.mu.Unlock()
 
 	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
-	var requestedGzip bool
 	if !cc.t.disableCompression() &&
 		req.Header.Get("Accept-Encoding") == "" &&
 		req.Header.Get("Range") == "" &&
-		req.Method != "HEAD" {
+		!cs.isHead {
 		// Request gzip only, not deflate. Deflate is ambiguous and
 		// not as universally supported anyway.
 		// See: https://zlib.net/zlib_faq.html#faq39
@@ -1071,195 +1381,232 @@
 		// We don't request gzip if the request is for a range, since
 		// auto-decoding a portion of a gzipped document will just fail
 		// anyway. See https://golang.org/issue/8923
-		requestedGzip = true
+		cs.requestedGzip = true
 	}
 
-	// we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is
-	// sent by writeRequestBody below, along with any Trailers,
-	// again in form HEADERS{1}, CONTINUATION{0,})
-	hdrs, err := cc.encodeHeaders(req, requestedGzip, trailers, contentLen)
+	continueTimeout := cc.t.expectContinueTimeout()
+	if continueTimeout != 0 {
+		if !httpguts.HeaderValuesContainsToken(req.Header["Expect"], "100-continue") {
+			continueTimeout = 0
+		} else {
+			cs.on100 = make(chan struct{}, 1)
+		}
+	}
+
+	// Past this point (where we send request headers), it is possible for
+	// RoundTrip to return successfully. Since the RoundTrip contract permits
+	// the caller to "mutate or reuse" the Request after closing the Response's Body,
+	// we must take care when referencing the Request from here on.
+	err = cs.encodeAndWriteHeaders(req)
+	<-cc.reqHeaderMu
 	if err != nil {
-		cc.mu.Unlock()
-		return nil, false, err
+		return err
 	}
 
-	cs := cc.newStream()
-	cs.req = req
-	cs.trace = httptrace.ContextClientTrace(req.Context())
-	cs.requestedGzip = requestedGzip
-	bodyWriter := cc.t.getBodyWriterState(cs, body)
-	cs.on100 = bodyWriter.on100
-
-	defer func() {
-		cc.wmu.Lock()
-		werr := cc.werr
-		cc.wmu.Unlock()
-		if werr != nil {
-			cc.Close()
+	hasBody := cs.reqBodyContentLength != 0
+	if !hasBody {
+		cs.sentEndStream = true
+	} else {
+		if continueTimeout != 0 {
+			traceWait100Continue(cs.trace)
+			timer := time.NewTimer(continueTimeout)
+			select {
+			case <-timer.C:
+				err = nil
+			case <-cs.on100:
+				err = nil
+			case <-cs.abort:
+				err = cs.abortErr
+			case <-ctx.Done():
+				err = ctx.Err()
+			case <-cs.reqCancel:
+				err = errRequestCanceled
+			}
+			timer.Stop()
+			if err != nil {
+				traceWroteRequest(cs.trace, err)
+				return err
+			}
 		}
-	}()
 
-	cc.wmu.Lock()
-	endStream := !hasBody && !hasTrailers
-	werr := cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs)
-	cc.wmu.Unlock()
-	traceWroteHeaders(cs.trace)
-	cc.mu.Unlock()
-
-	if werr != nil {
-		if hasBody {
-			req.Body.Close() // per RoundTripper contract
-			bodyWriter.cancel()
+		if err = cs.writeRequestBody(req); err != nil {
+			if err != errStopReqBodyWrite {
+				traceWroteRequest(cs.trace, err)
+				return err
+			}
+		} else {
+			cs.sentEndStream = true
 		}
-		cc.forgetStreamID(cs.ID)
-		// Don't bother sending a RST_STREAM (our write already failed;
-		// no need to keep writing)
-		traceWroteRequest(cs.trace, werr)
-		return nil, false, werr
 	}
 
+	traceWroteRequest(cs.trace, err)
+
 	var respHeaderTimer <-chan time.Time
-	if hasBody {
-		bodyWriter.scheduleBodyWrite()
-	} else {
-		traceWroteRequest(cs.trace, nil)
-		if d := cc.responseHeaderTimeout(); d != 0 {
-			timer := time.NewTimer(d)
-			defer timer.Stop()
-			respHeaderTimer = timer.C
-		}
+	var respHeaderRecv chan struct{}
+	if d := cc.responseHeaderTimeout(); d != 0 {
+		timer := time.NewTimer(d)
+		defer timer.Stop()
+		respHeaderTimer = timer.C
+		respHeaderRecv = cs.respHeaderRecv
 	}
-
-	readLoopResCh := cs.resc
-	bodyWritten := false
-	ctx := req.Context()
-
-	handleReadLoopResponse := func(re resAndError) (*http.Response, bool, error) {
-		res := re.res
-		if re.err != nil || res.StatusCode > 299 {
-			// On error or status code 3xx, 4xx, 5xx, etc abort any
-			// ongoing write, assuming that the server doesn't care
-			// about our request body. If the server replied with 1xx or
-			// 2xx, however, then assume the server DOES potentially
-			// want our body (e.g. full-duplex streaming:
-			// golang.org/issue/13444). If it turns out the server
-			// doesn't, they'll RST_STREAM us soon enough. This is a
-			// heuristic to avoid adding knobs to Transport. Hopefully
-			// we can keep it.
-			bodyWriter.cancel()
-			cs.abortRequestBodyWrite(errStopReqBodyWrite)
-			if hasBody && !bodyWritten {
-				<-bodyWriter.resc
-			}
-		}
-		if re.err != nil {
-			cc.forgetStreamID(cs.ID)
-			return nil, cs.getStartedWrite(), re.err
-		}
-		res.Request = req
-		res.TLS = cc.tlsState
-		return res, false, nil
-	}
-
+	// Wait until the peer half-closes its end of the stream,
+	// or until the request is aborted (via context, error, or otherwise),
+	// whichever comes first.
 	for {
 		select {
-		case re := <-readLoopResCh:
-			return handleReadLoopResponse(re)
+		case <-cs.peerClosed:
+			return nil
 		case <-respHeaderTimer:
-			if !hasBody || bodyWritten {
-				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
-			} else {
-				bodyWriter.cancel()
-				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
-				<-bodyWriter.resc
-			}
-			cc.forgetStreamID(cs.ID)
-			return nil, cs.getStartedWrite(), errTimeout
+			return errTimeout
+		case <-respHeaderRecv:
+			respHeaderRecv = nil
+			respHeaderTimer = nil // keep waiting for END_STREAM
+		case <-cs.abort:
+			return cs.abortErr
 		case <-ctx.Done():
-			if !hasBody || bodyWritten {
-				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
-			} else {
-				bodyWriter.cancel()
-				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
-				<-bodyWriter.resc
-			}
-			cc.forgetStreamID(cs.ID)
-			return nil, cs.getStartedWrite(), ctx.Err()
-		case <-req.Cancel:
-			if !hasBody || bodyWritten {
-				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
-			} else {
-				bodyWriter.cancel()
-				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
-				<-bodyWriter.resc
-			}
-			cc.forgetStreamID(cs.ID)
-			return nil, cs.getStartedWrite(), errRequestCanceled
-		case <-cs.peerReset:
-			// processResetStream already removed the
-			// stream from the streams map; no need for
-			// forgetStreamID.
-			return nil, cs.getStartedWrite(), cs.resetErr
-		case err := <-bodyWriter.resc:
-			bodyWritten = true
-			// Prefer the read loop's response, if available. Issue 16102.
-			select {
-			case re := <-readLoopResCh:
-				return handleReadLoopResponse(re)
-			default:
-			}
-			if err != nil {
-				cc.forgetStreamID(cs.ID)
-				return nil, cs.getStartedWrite(), err
-			}
-			if d := cc.responseHeaderTimeout(); d != 0 {
-				timer := time.NewTimer(d)
-				defer timer.Stop()
-				respHeaderTimer = timer.C
-			}
+			return ctx.Err()
+		case <-cs.reqCancel:
+			return errRequestCanceled
 		}
 	}
 }
 
-// awaitOpenSlotForRequest waits until len(streams) < maxConcurrentStreams.
+func (cs *clientStream) encodeAndWriteHeaders(req *http.Request) error {
+	cc := cs.cc
+	ctx := cs.ctx
+
+	cc.wmu.Lock()
+	defer cc.wmu.Unlock()
+
+	// If the request was canceled while waiting for cc.mu, just quit.
+	select {
+	case <-cs.abort:
+		return cs.abortErr
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-cs.reqCancel:
+		return errRequestCanceled
+	default:
+	}
+
+	// Encode headers.
+	//
+	// we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is
+	// sent by writeRequestBody below, along with any Trailers,
+	// again in form HEADERS{1}, CONTINUATION{0,})
+	trailers, err := commaSeparatedTrailers(req)
+	if err != nil {
+		return err
+	}
+	hasTrailers := trailers != ""
+	contentLen := actualContentLength(req)
+	hasBody := contentLen != 0
+	hdrs, err := cc.encodeHeaders(req, cs.requestedGzip, trailers, contentLen)
+	if err != nil {
+		return err
+	}
+
+	// Write the request.
+	endStream := !hasBody && !hasTrailers
+	cs.sentHeaders = true
+	err = cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs)
+	traceWroteHeaders(cs.trace)
+	return err
+}
+
+// cleanupWriteRequest performs post-request tasks.
+//
+// If err (the result of writeRequest) is non-nil and the stream is not closed,
+// cleanupWriteRequest will send a reset to the peer.
+func (cs *clientStream) cleanupWriteRequest(err error) {
+	cc := cs.cc
+
+	if cs.ID == 0 {
+		// We were canceled before creating the stream, so return our reservation.
+		cc.decrStreamReservations()
+	}
+
+	// TODO: write h12Compare test showing whether
+	// Request.Body is closed by the Transport,
+	// and in multiple cases: server replies <=299 and >299
+	// while still writing request body
+	cc.mu.Lock()
+	mustCloseBody := false
+	if cs.reqBody != nil && cs.reqBodyClosed == nil {
+		mustCloseBody = true
+		cs.reqBodyClosed = make(chan struct{})
+	}
+	bodyClosed := cs.reqBodyClosed
+	cc.mu.Unlock()
+	if mustCloseBody {
+		cs.reqBody.Close()
+		close(bodyClosed)
+	}
+	if bodyClosed != nil {
+		<-bodyClosed
+	}
+
+	if err != nil && cs.sentEndStream {
+		// If the connection is closed immediately after the response is read,
+		// we may be aborted before finishing up here. If the stream was closed
+		// cleanly on both sides, there is no error.
+		select {
+		case <-cs.peerClosed:
+			err = nil
+		default:
+		}
+	}
+	if err != nil {
+		cs.abortStream(err) // possibly redundant, but harmless
+		if cs.sentHeaders {
+			if se, ok := err.(StreamError); ok {
+				if se.Cause != errFromPeer {
+					cc.writeStreamReset(cs.ID, se.Code, err)
+				}
+			} else {
+				cc.writeStreamReset(cs.ID, ErrCodeCancel, err)
+			}
+		}
+		cs.bufPipe.CloseWithError(err) // no-op if already closed
+	} else {
+		if cs.sentHeaders && !cs.sentEndStream {
+			cc.writeStreamReset(cs.ID, ErrCodeNo, nil)
+		}
+		cs.bufPipe.CloseWithError(errRequestCanceled)
+	}
+	if cs.ID != 0 {
+		cc.forgetStreamID(cs.ID)
+	}
+
+	cc.wmu.Lock()
+	werr := cc.werr
+	cc.wmu.Unlock()
+	if werr != nil {
+		cc.Close()
+	}
+
+	close(cs.donec)
+}
+
+// awaitOpenSlotForStreamLocked waits until len(streams) < maxConcurrentStreams.
 // Must hold cc.mu.
-func (cc *ClientConn) awaitOpenSlotForRequest(req *http.Request) error {
-	var waitingForConn chan struct{}
-	var waitingForConnErr error // guarded by cc.mu
+func (cc *ClientConn) awaitOpenSlotForStreamLocked(cs *clientStream) error {
 	for {
 		cc.lastActive = time.Now()
 		if cc.closed || !cc.canTakeNewRequestLocked() {
-			if waitingForConn != nil {
-				close(waitingForConn)
-			}
 			return errClientConnUnusable
 		}
 		cc.lastIdle = time.Time{}
-		if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) {
-			if waitingForConn != nil {
-				close(waitingForConn)
-			}
+		if int64(len(cc.streams)) < int64(cc.maxConcurrentStreams) {
 			return nil
 		}
-		// Unfortunately, we cannot wait on a condition variable and channel at
-		// the same time, so instead, we spin up a goroutine to check if the
-		// request is canceled while we wait for a slot to open in the connection.
-		if waitingForConn == nil {
-			waitingForConn = make(chan struct{})
-			go func() {
-				if err := awaitRequestCancel(req, waitingForConn); err != nil {
-					cc.mu.Lock()
-					waitingForConnErr = err
-					cc.cond.Broadcast()
-					cc.mu.Unlock()
-				}
-			}()
-		}
 		cc.pendingRequests++
 		cc.cond.Wait()
 		cc.pendingRequests--
-		if waitingForConnErr != nil {
-			return waitingForConnErr
+		select {
+		case <-cs.abort:
+			return cs.abortErr
+		default:
 		}
 	}
 }
@@ -1286,10 +1633,6 @@
 			cc.fr.WriteContinuation(streamID, endHeaders, chunk)
 		}
 	}
-	// TODO(bradfitz): this Flush could potentially block (as
-	// could the WriteHeaders call(s) above), which means they
-	// wouldn't respond to Request.Cancel being readable. That's
-	// rare, but this should probably be in a goroutine.
 	cc.bw.Flush()
 	return cc.werr
 }
@@ -1305,32 +1648,59 @@
 	errReqBodyTooLong = errors.New("http2: request body larger than specified content length")
 )
 
-func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) {
+// frameScratchBufferLen returns the length of a buffer to use for
+// outgoing request bodies to read/write to/from.
+//
+// It returns max(1, min(peer's advertised max frame size,
+// Request.ContentLength+1, 512KB)).
+func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int {
+	const max = 512 << 10
+	n := int64(maxFrameSize)
+	if n > max {
+		n = max
+	}
+	if cl := cs.reqBodyContentLength; cl != -1 && cl+1 < n {
+		// Add an extra byte past the declared content-length to
+		// give the caller's Request.Body io.Reader a chance to
+		// give us more bytes than they declared, so we can catch it
+		// early.
+		n = cl + 1
+	}
+	if n < 1 {
+		return 1
+	}
+	return int(n) // doesn't truncate; max is 512K
+}
+
+var bufPool sync.Pool // of *[]byte
+
+func (cs *clientStream) writeRequestBody(req *http.Request) (err error) {
 	cc := cs.cc
+	body := cs.reqBody
 	sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
-	buf := cc.frameScratchBuffer()
-	defer cc.putFrameScratchBuffer(buf)
 
-	defer func() {
-		traceWroteRequest(cs.trace, err)
-		// TODO: write h12Compare test showing whether
-		// Request.Body is closed by the Transport,
-		// and in multiple cases: server replies <=299 and >299
-		// while still writing request body
-		cerr := bodyCloser.Close()
-		if err == nil {
-			err = cerr
-		}
-	}()
-
-	req := cs.req
 	hasTrailers := req.Trailer != nil
-	remainLen := actualContentLength(req)
+	remainLen := cs.reqBodyContentLength
 	hasContentLen := remainLen != -1
 
+	cc.mu.Lock()
+	maxFrameSize := int(cc.maxFrameSize)
+	cc.mu.Unlock()
+
+	// Scratch buffer for reading into & writing from.
+	scratchLen := cs.frameScratchBufferLen(maxFrameSize)
+	var buf []byte
+	if bp, ok := bufPool.Get().(*[]byte); ok && len(*bp) >= scratchLen {
+		defer bufPool.Put(bp)
+		buf = *bp
+	} else {
+		buf = make([]byte, scratchLen)
+		defer bufPool.Put(&buf)
+	}
+
 	var sawEOF bool
 	for !sawEOF {
-		n, err := body.Read(buf[:len(buf)-1])
+		n, err := body.Read(buf)
 		if hasContentLen {
 			remainLen -= int64(n)
 			if remainLen == 0 && err == nil {
@@ -1341,35 +1711,36 @@
 				// to send the END_STREAM bit early, double-check that we're actually
 				// at EOF. Subsequent reads should return (0, EOF) at this point.
 				// If either value is different, we return an error in one of two ways below.
+				var scratch [1]byte
 				var n1 int
-				n1, err = body.Read(buf[n:])
+				n1, err = body.Read(scratch[:])
 				remainLen -= int64(n1)
 			}
 			if remainLen < 0 {
 				err = errReqBodyTooLong
-				cc.writeStreamReset(cs.ID, ErrCodeCancel, err)
 				return err
 			}
 		}
-		if err == io.EOF {
-			sawEOF = true
-			err = nil
-		} else if err != nil {
-			cc.writeStreamReset(cs.ID, ErrCodeCancel, err)
-			return err
+		if err != nil {
+			cc.mu.Lock()
+			bodyClosed := cs.reqBodyClosed != nil
+			cc.mu.Unlock()
+			switch {
+			case bodyClosed:
+				return errStopReqBodyWrite
+			case err == io.EOF:
+				sawEOF = true
+				err = nil
+			default:
+				return err
+			}
 		}
 
 		remain := buf[:n]
 		for len(remain) > 0 && err == nil {
 			var allowed int32
 			allowed, err = cs.awaitFlowControl(len(remain))
-			switch {
-			case err == errStopReqBodyWrite:
-				return err
-			case err == errStopReqBodyWriteAndCancel:
-				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
-				return err
-			case err != nil:
+			if err != nil {
 				return err
 			}
 			cc.wmu.Lock()
@@ -1400,24 +1771,26 @@
 		return nil
 	}
 
-	var trls []byte
-	if hasTrailers {
-		cc.mu.Lock()
-		trls, err = cc.encodeTrailers(req)
-		cc.mu.Unlock()
-		if err != nil {
-			cc.writeStreamReset(cs.ID, ErrCodeInternal, err)
-			cc.forgetStreamID(cs.ID)
-			return err
-		}
-	}
-
+	// Since the RoundTrip contract permits the caller to "mutate or reuse"
+	// a request after the Response's Body is closed, verify that this hasn't
+	// happened before accessing the trailers.
 	cc.mu.Lock()
-	maxFrameSize := int(cc.maxFrameSize)
+	trailer := req.Trailer
+	err = cs.abortErr
 	cc.mu.Unlock()
+	if err != nil {
+		return err
+	}
 
 	cc.wmu.Lock()
 	defer cc.wmu.Unlock()
+	var trls []byte
+	if len(trailer) > 0 {
+		trls, err = cc.encodeTrailers(trailer)
+		if err != nil {
+			return err
+		}
+	}
 
 	// Two ways to send END_STREAM: either with trailers, or
 	// with an empty DATA frame.
@@ -1438,17 +1811,24 @@
 // if the stream is dead.
 func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) {
 	cc := cs.cc
+	ctx := cs.ctx
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	for {
 		if cc.closed {
 			return 0, errClientConnClosed
 		}
-		if cs.stopReqBody != nil {
-			return 0, cs.stopReqBody
+		if cs.reqBodyClosed != nil {
+			return 0, errStopReqBodyWrite
 		}
-		if err := cs.checkResetOrDone(); err != nil {
-			return 0, err
+		select {
+		case <-cs.abort:
+			return 0, cs.abortErr
+		case <-ctx.Done():
+			return 0, ctx.Err()
+		case <-cs.reqCancel:
+			return 0, errRequestCanceled
+		default:
 		}
 		if a := cs.flow.available(); a > 0 {
 			take := a
@@ -1466,9 +1846,14 @@
 	}
 }
 
-// requires cc.mu be held.
+var errNilRequestURL = errors.New("http2: Request.URI is nil")
+
+// requires cc.wmu be held.
 func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) {
 	cc.hbuf.Reset()
+	if req.URL == nil {
+		return nil, errNilRequestURL
+	}
 
 	host := req.Host
 	if host == "" {
@@ -1504,7 +1889,8 @@
 		}
 		for _, v := range vv {
 			if !httpguts.ValidHeaderFieldValue(v) {
-				return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, k)
+				// Don't include the value in the error, because it may be sensitive.
+				return nil, fmt.Errorf("invalid HTTP header value for header %q", k)
 			}
 		}
 	}
@@ -1531,19 +1917,21 @@
 
 		var didUA bool
 		for k, vv := range req.Header {
-			if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
+			if asciiEqualFold(k, "host") || asciiEqualFold(k, "content-length") {
 				// Host is :authority, already sent.
 				// Content-Length is automatic, set below.
 				continue
-			} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
-				strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
-				strings.EqualFold(k, "keep-alive") {
+			} else if asciiEqualFold(k, "connection") ||
+				asciiEqualFold(k, "proxy-connection") ||
+				asciiEqualFold(k, "transfer-encoding") ||
+				asciiEqualFold(k, "upgrade") ||
+				asciiEqualFold(k, "keep-alive") {
 				// Per 8.1.2.2 Connection-Specific Header
 				// Fields, don't send connection-specific
 				// fields. We have already checked if any
 				// are error-worthy so just ignore the rest.
 				continue
-			} else if strings.EqualFold(k, "user-agent") {
+			} else if asciiEqualFold(k, "user-agent") {
 				// Match Go's http1 behavior: at most one
 				// User-Agent. If set to nil or empty string,
 				// then omit it. Otherwise if not mentioned,
@@ -1556,7 +1944,7 @@
 				if vv[0] == "" {
 					continue
 				}
-			} else if strings.EqualFold(k, "cookie") {
+			} else if asciiEqualFold(k, "cookie") {
 				// Per 8.1.2.5 To allow for better compression efficiency, the
 				// Cookie header field MAY be split into separate header fields,
 				// each with one or more cookie-pairs.
@@ -1615,7 +2003,12 @@
 
 	// Header list size is ok. Write the headers.
 	enumerateHeaders(func(name, value string) {
-		name = strings.ToLower(name)
+		name, ascii := lowerHeader(name)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			return
+		}
 		cc.writeHeader(name, value)
 		if traceHeaders {
 			traceWroteHeaderField(trace, name, value)
@@ -1647,12 +2040,12 @@
 	}
 }
 
-// requires cc.mu be held.
-func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) {
+// requires cc.wmu be held.
+func (cc *ClientConn) encodeTrailers(trailer http.Header) ([]byte, error) {
 	cc.hbuf.Reset()
 
 	hlSize := uint64(0)
-	for k, vv := range req.Trailer {
+	for k, vv := range trailer {
 		for _, v := range vv {
 			hf := hpack.HeaderField{Name: k, Value: v}
 			hlSize += uint64(hf.Size())
@@ -1662,10 +2055,15 @@
 		return nil, errRequestHeaderListSize
 	}
 
-	for k, vv := range req.Trailer {
+	for k, vv := range trailer {
+		lowKey, ascii := lowerHeader(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		// Transfer-Encoding, etc.. have already been filtered at the
 		// start of RoundTrip
-		lowKey := strings.ToLower(k)
 		for _, v := range vv {
 			cc.writeHeader(lowKey, v)
 		}
@@ -1687,51 +2085,50 @@
 }
 
 // requires cc.mu be held.
-func (cc *ClientConn) newStream() *clientStream {
-	cs := &clientStream{
-		cc:        cc,
-		ID:        cc.nextStreamID,
-		resc:      make(chan resAndError, 1),
-		peerReset: make(chan struct{}),
-		done:      make(chan struct{}),
-	}
+func (cc *ClientConn) addStreamLocked(cs *clientStream) {
 	cs.flow.add(int32(cc.initialWindowSize))
 	cs.flow.setConnFlow(&cc.flow)
-	cs.inflow.add(transportDefaultStreamFlow)
-	cs.inflow.setConnFlow(&cc.inflow)
+	cs.inflow.init(transportDefaultStreamFlow)
+	cs.ID = cc.nextStreamID
 	cc.nextStreamID += 2
 	cc.streams[cs.ID] = cs
-	return cs
+	if cs.ID == 0 {
+		panic("assigned stream ID 0")
+	}
 }
 
 func (cc *ClientConn) forgetStreamID(id uint32) {
-	cc.streamByID(id, true)
-}
-
-func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream {
 	cc.mu.Lock()
-	defer cc.mu.Unlock()
-	cs := cc.streams[id]
-	if andRemove && cs != nil && !cc.closed {
-		cc.lastActive = time.Now()
-		delete(cc.streams, id)
-		if len(cc.streams) == 0 && cc.idleTimer != nil {
-			cc.idleTimer.Reset(cc.idleTimeout)
-			cc.lastIdle = time.Now()
-		}
-		close(cs.done)
-		// Wake up checkResetOrDone via clientStream.awaitFlowControl and
-		// wake up RoundTrip if there is a pending request.
-		cc.cond.Broadcast()
+	slen := len(cc.streams)
+	delete(cc.streams, id)
+	if len(cc.streams) != slen-1 {
+		panic("forgetting unknown stream id")
 	}
-	return cs
+	cc.lastActive = time.Now()
+	if len(cc.streams) == 0 && cc.idleTimer != nil {
+		cc.idleTimer.Reset(cc.idleTimeout)
+		cc.lastIdle = time.Now()
+	}
+	// Wake up writeRequestBody via clientStream.awaitFlowControl and
+	// wake up RoundTrip if there is a pending request.
+	cc.cond.Broadcast()
+
+	closeOnIdle := cc.singleUse || cc.doNotReuse || cc.t.disableKeepAlives() || cc.goAway != nil
+	if closeOnIdle && cc.streamsReserved == 0 && len(cc.streams) == 0 {
+		if VerboseLogs {
+			cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, cc.nextStreamID-2)
+		}
+		cc.closed = true
+		defer cc.closeConn()
+	}
+
+	cc.mu.Unlock()
 }
 
 // clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
 type clientConnReadLoop struct {
-	_             incomparable
-	cc            *ClientConn
-	closeWhenIdle bool
+	_  incomparable
+	cc *ClientConn
 }
 
 // readLoop runs in its own goroutine and reads and dispatches frames.
@@ -1769,8 +2166,8 @@
 
 func (rl *clientConnReadLoop) cleanup() {
 	cc := rl.cc
-	defer cc.tconn.Close()
-	defer cc.t.connPool().MarkDead(cc)
+	cc.t.connPool().MarkDead(cc)
+	defer cc.closeConn()
 	defer close(cc.readerDone)
 
 	if cc.idleTimer != nil {
@@ -1791,23 +2188,50 @@
 	} else if err == io.EOF {
 		err = io.ErrUnexpectedEOF
 	}
-	for _, cs := range cc.streams {
-		cs.bufPipe.CloseWithError(err) // no-op if already closed
-		select {
-		case cs.resc <- resAndError{err: err}:
-		default:
-		}
-		close(cs.done)
-	}
 	cc.closed = true
+
+	for _, cs := range cc.streams {
+		select {
+		case <-cs.peerClosed:
+			// The server closed the stream before closing the conn,
+			// so no need to interrupt it.
+		default:
+			cs.abortStreamLocked(err)
+		}
+	}
 	cc.cond.Broadcast()
 	cc.mu.Unlock()
 }
 
+// countReadFrameError calls Transport.CountError with a string
+// representing err.
+func (cc *ClientConn) countReadFrameError(err error) {
+	f := cc.t.CountError
+	if f == nil || err == nil {
+		return
+	}
+	if ce, ok := err.(ConnectionError); ok {
+		errCode := ErrCode(ce)
+		f(fmt.Sprintf("read_frame_conn_error_%s", errCode.stringToken()))
+		return
+	}
+	if errors.Is(err, io.EOF) {
+		f("read_frame_eof")
+		return
+	}
+	if errors.Is(err, io.ErrUnexpectedEOF) {
+		f("read_frame_unexpected_eof")
+		return
+	}
+	if errors.Is(err, ErrFrameTooLarge) {
+		f("read_frame_too_large")
+		return
+	}
+	f("read_frame_other")
+}
+
 func (rl *clientConnReadLoop) run() error {
 	cc := rl.cc
-	rl.closeWhenIdle = cc.t.disableKeepAlives() || cc.singleUse
-	gotReply := false // ever saw a HEADERS reply
 	gotSettings := false
 	readIdleTimeout := cc.t.ReadIdleTimeout
 	var t *time.Timer
@@ -1824,9 +2248,7 @@
 			cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err)
 		}
 		if se, ok := err.(StreamError); ok {
-			if cs := cc.streamByID(se.StreamID, false); cs != nil {
-				cs.cc.writeStreamReset(cs.ID, se.Code, err)
-				cs.cc.forgetStreamID(cs.ID)
+			if cs := rl.streamByID(se.StreamID); cs != nil {
 				if se.Cause == nil {
 					se.Cause = cc.fr.errDetail
 				}
@@ -1834,6 +2256,7 @@
 			}
 			continue
 		} else if err != nil {
+			cc.countReadFrameError(err)
 			return err
 		}
 		if VerboseLogs {
@@ -1846,22 +2269,16 @@
 			}
 			gotSettings = true
 		}
-		maybeIdle := false // whether frame might transition us to idle
 
 		switch f := f.(type) {
 		case *MetaHeadersFrame:
 			err = rl.processHeaders(f)
-			maybeIdle = true
-			gotReply = true
 		case *DataFrame:
 			err = rl.processData(f)
-			maybeIdle = true
 		case *GoAwayFrame:
 			err = rl.processGoAway(f)
-			maybeIdle = true
 		case *RSTStreamFrame:
 			err = rl.processResetStream(f)
-			maybeIdle = true
 		case *SettingsFrame:
 			err = rl.processSettings(f)
 		case *PushPromiseFrame:
@@ -1879,38 +2296,24 @@
 			}
 			return err
 		}
-		if rl.closeWhenIdle && gotReply && maybeIdle {
-			cc.closeIfIdle()
-		}
 	}
 }
 
 func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
-	cc := rl.cc
-	cs := cc.streamByID(f.StreamID, false)
+	cs := rl.streamByID(f.StreamID)
 	if cs == nil {
 		// We'd get here if we canceled a request while the
 		// server had its response still in flight. So if this
 		// was just something we canceled, ignore it.
 		return nil
 	}
-	if f.StreamEnded() {
-		// Issue 20521: If the stream has ended, streamByID() causes
-		// clientStream.done to be closed, which causes the request's bodyWriter
-		// to be closed with an errStreamClosed, which may be received by
-		// clientConn.RoundTrip before the result of processing these headers.
-		// Deferring stream closure allows the header processing to occur first.
-		// clientConn.RoundTrip may still receive the bodyWriter error first, but
-		// the fix for issue 16102 prioritises any response.
-		//
-		// Issue 22413: If there is no request body, we should close the
-		// stream before writing to cs.resc so that the stream is closed
-		// immediately once RoundTrip returns.
-		if cs.req.Body != nil {
-			defer cc.forgetStreamID(f.StreamID)
-		} else {
-			cc.forgetStreamID(f.StreamID)
-		}
+	if cs.readClosed {
+		rl.endStreamError(cs, StreamError{
+			StreamID: f.StreamID,
+			Code:     ErrCodeProtocol,
+			Cause:    errors.New("protocol error: headers after END_STREAM"),
+		})
+		return nil
 	}
 	if !cs.firstByte {
 		if cs.trace != nil {
@@ -1934,9 +2337,11 @@
 			return err
 		}
 		// Any other error type is a stream error.
-		cs.cc.writeStreamReset(f.StreamID, ErrCodeProtocol, err)
-		cc.forgetStreamID(cs.ID)
-		cs.resc <- resAndError{err: err}
+		rl.endStreamError(cs, StreamError{
+			StreamID: f.StreamID,
+			Code:     ErrCodeProtocol,
+			Cause:    err,
+		})
 		return nil // return nil from process* funcs to keep conn alive
 	}
 	if res == nil {
@@ -1944,7 +2349,11 @@
 		return nil
 	}
 	cs.resTrailer = &res.Trailer
-	cs.resc <- resAndError{res: res}
+	cs.res = res
+	close(cs.respHeaderRecv)
+	if f.StreamEnded() {
+		rl.endStream(cs)
+	}
 	return nil
 }
 
@@ -1979,7 +2388,7 @@
 		Status:     status + " " + http.StatusText(statusCode),
 	}
 	for _, hf := range regularFields {
-		key := http.CanonicalHeaderKey(hf.Name)
+		key := canonicalHeader(hf.Name)
 		if key == "Trailer" {
 			t := res.Trailer
 			if t == nil {
@@ -1987,7 +2396,7 @@
 				res.Trailer = t
 			}
 			foreachHeaderElement(hf.Value, func(v string) {
-				t[http.CanonicalHeaderKey(v)] = nil
+				t[canonicalHeader(v)] = nil
 			})
 		} else {
 			vv := header[key]
@@ -2006,6 +2415,9 @@
 	}
 
 	if statusCode >= 100 && statusCode <= 199 {
+		if f.StreamEnded() {
+			return nil, errors.New("1xx informational response with END_STREAM flag")
+		}
 		cs.num1xx++
 		const max1xxResponses = 5 // arbitrary bound on number of informational responses, same as net/http
 		if cs.num1xx > max1xxResponses {
@@ -2018,42 +2430,49 @@
 		}
 		if statusCode == 100 {
 			traceGot100Continue(cs.trace)
-			if cs.on100 != nil {
-				cs.on100() // forces any write delay timer to fire
+			select {
+			case cs.on100 <- struct{}{}:
+			default:
 			}
 		}
 		cs.pastHeaders = false // do it all again
 		return nil, nil
 	}
 
-	streamEnded := f.StreamEnded()
-	isHead := cs.req.Method == "HEAD"
-	if !streamEnded || isHead {
-		res.ContentLength = -1
-		if clens := res.Header["Content-Length"]; len(clens) == 1 {
-			if cl, err := strconv.ParseUint(clens[0], 10, 63); err == nil {
-				res.ContentLength = int64(cl)
-			} else {
-				// TODO: care? unlike http/1, it won't mess up our framing, so it's
-				// more safe smuggling-wise to ignore.
-			}
-		} else if len(clens) > 1 {
+	res.ContentLength = -1
+	if clens := res.Header["Content-Length"]; len(clens) == 1 {
+		if cl, err := strconv.ParseUint(clens[0], 10, 63); err == nil {
+			res.ContentLength = int64(cl)
+		} else {
 			// TODO: care? unlike http/1, it won't mess up our framing, so it's
 			// more safe smuggling-wise to ignore.
 		}
+	} else if len(clens) > 1 {
+		// TODO: care? unlike http/1, it won't mess up our framing, so it's
+		// more safe smuggling-wise to ignore.
+	} else if f.StreamEnded() && !cs.isHead {
+		res.ContentLength = 0
 	}
 
-	if streamEnded || isHead {
+	if cs.isHead {
 		res.Body = noBody
 		return res, nil
 	}
 
-	cs.bufPipe = pipe{b: &dataBuffer{expected: res.ContentLength}}
+	if f.StreamEnded() {
+		if res.ContentLength > 0 {
+			res.Body = missingBody{}
+		} else {
+			res.Body = noBody
+		}
+		return res, nil
+	}
+
+	cs.bufPipe.setBuffer(&dataBuffer{expected: res.ContentLength})
 	cs.bytesRemain = res.ContentLength
 	res.Body = transportResponseBody{cs}
-	go cs.awaitRequestCancel(cs.req)
 
-	if cs.requestedGzip && res.Header.Get("Content-Encoding") == "gzip" {
+	if cs.requestedGzip && asciiEqualFold(res.Header.Get("Content-Encoding"), "gzip") {
 		res.Header.Del("Content-Encoding")
 		res.Header.Del("Content-Length")
 		res.ContentLength = -1
@@ -2082,7 +2501,7 @@
 
 	trailer := make(http.Header)
 	for _, hf := range f.RegularFields() {
-		key := http.CanonicalHeaderKey(hf.Name)
+		key := canonicalHeader(hf.Name)
 		trailer[key] = append(trailer[key], hf.Value)
 	}
 	cs.trailer = trailer
@@ -2092,8 +2511,7 @@
 }
 
 // transportResponseBody is the concrete type of Transport.RoundTrip's
-// Response.Body. It is an io.ReadCloser. On Read, it reads from cs.body.
-// On Close it sends RST_STREAM if EOF wasn't already seen.
+// Response.Body. It is an io.ReadCloser.
 type transportResponseBody struct {
 	cs *clientStream
 }
@@ -2111,7 +2529,7 @@
 			n = int(cs.bytesRemain)
 			if err == nil {
 				err = errors.New("net/http: server replied with more than declared Content-Length; truncated")
-				cc.writeStreamReset(cs.ID, ErrCodeProtocol, err)
+				cs.abortStream(err)
 			}
 			cs.readErr = err
 			return int(cs.bytesRemain), err
@@ -2129,24 +2547,13 @@
 	}
 
 	cc.mu.Lock()
-	defer cc.mu.Unlock()
-
-	var connAdd, streamAdd int32
-	// Check the conn-level first, before the stream-level.
-	if v := cc.inflow.available(); v < transportDefaultConnFlow/2 {
-		connAdd = transportDefaultConnFlow - v
-		cc.inflow.add(connAdd)
-	}
+	connAdd := cc.inflow.add(n)
+	var streamAdd int32
 	if err == nil { // No need to refresh if the stream is over or failed.
-		// Consider any buffered body data (read from the conn but not
-		// consumed by the client) when computing flow control for this
-		// stream.
-		v := int(cs.inflow.available()) + cs.bufPipe.Len()
-		if v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh {
-			streamAdd = int32(transportDefaultStreamFlow - v)
-			cs.inflow.add(streamAdd)
-		}
+		streamAdd = cs.inflow.add(n)
 	}
+	cc.mu.Unlock()
+
 	if connAdd != 0 || streamAdd != 0 {
 		cc.wmu.Lock()
 		defer cc.wmu.Unlock()
@@ -2167,34 +2574,43 @@
 	cs := b.cs
 	cc := cs.cc
 
-	serverSentStreamEnd := cs.bufPipe.Err() == io.EOF
-	unread := cs.bufPipe.Len()
+	cs.bufPipe.BreakWithError(errClosedResponseBody)
+	cs.abortStream(errClosedResponseBody)
 
-	if unread > 0 || !serverSentStreamEnd {
+	unread := cs.bufPipe.Len()
+	if unread > 0 {
 		cc.mu.Lock()
-		cc.wmu.Lock()
-		if !serverSentStreamEnd {
-			cc.fr.WriteRSTStream(cs.ID, ErrCodeCancel)
-			cs.didReset = true
-		}
 		// Return connection-level flow control.
-		if unread > 0 {
-			cc.inflow.add(int32(unread))
-			cc.fr.WriteWindowUpdate(0, uint32(unread))
+		connAdd := cc.inflow.add(unread)
+		cc.mu.Unlock()
+
+		// TODO(dneil): Acquiring this mutex can block indefinitely.
+		// Move flow control return to a goroutine?
+		cc.wmu.Lock()
+		// Return connection-level flow control.
+		if connAdd > 0 {
+			cc.fr.WriteWindowUpdate(0, uint32(connAdd))
 		}
 		cc.bw.Flush()
 		cc.wmu.Unlock()
-		cc.mu.Unlock()
 	}
 
-	cs.bufPipe.BreakWithError(errClosedResponseBody)
-	cc.forgetStreamID(cs.ID)
+	select {
+	case <-cs.donec:
+	case <-cs.ctx.Done():
+		// See golang/go#49366: The net/http package can cancel the
+		// request context after the response body is fully read.
+		// Don't treat this as an error.
+		return nil
+	case <-cs.reqCancel:
+		return errRequestCanceled
+	}
 	return nil
 }
 
 func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 	cc := rl.cc
-	cs := cc.streamByID(f.StreamID, f.StreamEnded())
+	cs := rl.streamByID(f.StreamID)
 	data := f.Data()
 	if cs == nil {
 		cc.mu.Lock()
@@ -2213,16 +2629,29 @@
 		// But at least return their flow control:
 		if f.Length > 0 {
 			cc.mu.Lock()
-			cc.inflow.add(int32(f.Length))
+			ok := cc.inflow.take(f.Length)
+			connAdd := cc.inflow.add(int(f.Length))
 			cc.mu.Unlock()
-
-			cc.wmu.Lock()
-			cc.fr.WriteWindowUpdate(0, uint32(f.Length))
-			cc.bw.Flush()
-			cc.wmu.Unlock()
+			if !ok {
+				return ConnectionError(ErrCodeFlowControl)
+			}
+			if connAdd > 0 {
+				cc.wmu.Lock()
+				cc.fr.WriteWindowUpdate(0, uint32(connAdd))
+				cc.bw.Flush()
+				cc.wmu.Unlock()
+			}
 		}
 		return nil
 	}
+	if cs.readClosed {
+		cc.logf("protocol error: received DATA after END_STREAM")
+		rl.endStreamError(cs, StreamError{
+			StreamID: f.StreamID,
+			Code:     ErrCodeProtocol,
+		})
+		return nil
+	}
 	if !cs.firstByte {
 		cc.logf("protocol error: received DATA before a HEADERS frame")
 		rl.endStreamError(cs, StreamError{
@@ -2232,7 +2661,7 @@
 		return nil
 	}
 	if f.Length > 0 {
-		if cs.req.Method == "HEAD" && len(data) > 0 {
+		if cs.isHead && len(data) > 0 {
 			cc.logf("protocol error: received DATA on a HEAD request")
 			rl.endStreamError(cs, StreamError{
 				StreamID: f.StreamID,
@@ -2242,9 +2671,7 @@
 		}
 		// Check connection-level flow control.
 		cc.mu.Lock()
-		if cs.inflow.available() >= int32(f.Length) {
-			cs.inflow.take(int32(f.Length))
-		} else {
+		if !takeInflows(&cc.inflow, &cs.inflow, f.Length) {
 			cc.mu.Unlock()
 			return ConnectionError(ErrCodeFlowControl)
 		}
@@ -2254,30 +2681,40 @@
 		if pad := int(f.Length) - len(data); pad > 0 {
 			refund += pad
 		}
-		// Return len(data) now if the stream is already closed,
-		// since data will never be read.
-		didReset := cs.didReset
-		if didReset {
-			refund += len(data)
+
+		didReset := false
+		var err error
+		if len(data) > 0 {
+			if _, err = cs.bufPipe.Write(data); err != nil {
+				// Return len(data) now if the stream is already closed,
+				// since data will never be read.
+				didReset = true
+				refund += len(data)
+			}
 		}
-		if refund > 0 {
-			cc.inflow.add(int32(refund))
+
+		sendConn := cc.inflow.add(refund)
+		var sendStream int32
+		if !didReset {
+			sendStream = cs.inflow.add(refund)
+		}
+		cc.mu.Unlock()
+
+		if sendConn > 0 || sendStream > 0 {
 			cc.wmu.Lock()
-			cc.fr.WriteWindowUpdate(0, uint32(refund))
-			if !didReset {
-				cs.inflow.add(int32(refund))
-				cc.fr.WriteWindowUpdate(cs.ID, uint32(refund))
+			if sendConn > 0 {
+				cc.fr.WriteWindowUpdate(0, uint32(sendConn))
+			}
+			if sendStream > 0 {
+				cc.fr.WriteWindowUpdate(cs.ID, uint32(sendStream))
 			}
 			cc.bw.Flush()
 			cc.wmu.Unlock()
 		}
-		cc.mu.Unlock()
 
-		if len(data) > 0 && !didReset {
-			if _, err := cs.bufPipe.Write(data); err != nil {
-				rl.endStreamError(cs, err)
-				return err
-			}
+		if err != nil {
+			rl.endStreamError(cs, err)
+			return nil
 		}
 	}
 
@@ -2290,24 +2727,32 @@
 func (rl *clientConnReadLoop) endStream(cs *clientStream) {
 	// TODO: check that any declared content-length matches, like
 	// server.go's (*stream).endStream method.
-	rl.endStreamError(cs, nil)
+	if !cs.readClosed {
+		cs.readClosed = true
+		// Close cs.bufPipe and cs.peerClosed with cc.mu held to avoid a
+		// race condition: The caller can read io.EOF from Response.Body
+		// and close the body before we close cs.peerClosed, causing
+		// cleanupWriteRequest to send a RST_STREAM.
+		rl.cc.mu.Lock()
+		defer rl.cc.mu.Unlock()
+		cs.bufPipe.closeWithErrorAndCode(io.EOF, cs.copyTrailers)
+		close(cs.peerClosed)
+	}
 }
 
 func (rl *clientConnReadLoop) endStreamError(cs *clientStream, err error) {
-	var code func()
-	if err == nil {
-		err = io.EOF
-		code = cs.copyTrailers
-	}
-	if isConnectionCloseRequest(cs.req) {
-		rl.closeWhenIdle = true
-	}
-	cs.bufPipe.closeWithErrorAndCode(err, code)
+	cs.readAborted = true
+	cs.abortStream(err)
+}
 
-	select {
-	case cs.resc <- resAndError{err: err}:
-	default:
+func (rl *clientConnReadLoop) streamByID(id uint32) *clientStream {
+	rl.cc.mu.Lock()
+	defer rl.cc.mu.Unlock()
+	cs := rl.cc.streams[id]
+	if cs != nil && !cs.readAborted {
+		return cs
 	}
+	return nil
 }
 
 func (cs *clientStream) copyTrailers() {
@@ -2326,6 +2771,9 @@
 	if f.ErrCode != 0 {
 		// TODO: deal with GOAWAY more. particularly the error code
 		cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode)
+		if fn := cc.t.CountError; fn != nil {
+			fn("recv_goaway_" + f.ErrCode.stringToken())
+		}
 	}
 	cc.setGoAway(f)
 	return nil
@@ -2333,6 +2781,23 @@
 
 func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error {
 	cc := rl.cc
+	// Locking both mu and wmu here allows frame encoding to read settings with only wmu held.
+	// Acquiring wmu when f.IsAck() is unnecessary, but convenient and mostly harmless.
+	cc.wmu.Lock()
+	defer cc.wmu.Unlock()
+
+	if err := rl.processSettingsNoWrite(f); err != nil {
+		return err
+	}
+	if !f.IsAck() {
+		cc.fr.WriteSettingsAck()
+		cc.bw.Flush()
+	}
+	return nil
+}
+
+func (rl *clientConnReadLoop) processSettingsNoWrite(f *SettingsFrame) error {
+	cc := rl.cc
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 
@@ -2344,12 +2809,14 @@
 		return ConnectionError(ErrCodeProtocol)
 	}
 
+	var seenMaxConcurrentStreams bool
 	err := f.ForeachSetting(func(s Setting) error {
 		switch s.ID {
 		case SettingMaxFrameSize:
 			cc.maxFrameSize = s.Val
 		case SettingMaxConcurrentStreams:
 			cc.maxConcurrentStreams = s.Val
+			seenMaxConcurrentStreams = true
 		case SettingMaxHeaderListSize:
 			cc.peerMaxHeaderListSize = uint64(s.Val)
 		case SettingInitialWindowSize:
@@ -2371,8 +2838,10 @@
 			cc.cond.Broadcast()
 
 			cc.initialWindowSize = s.Val
+		case SettingHeaderTableSize:
+			cc.henc.SetMaxDynamicTableSize(s.Val)
+			cc.peerMaxHeaderTableSize = s.Val
 		default:
-			// TODO(bradfitz): handle more settings? SETTINGS_HEADER_TABLE_SIZE probably.
 			cc.vlogf("Unhandled Setting: %v", s)
 		}
 		return nil
@@ -2381,17 +2850,23 @@
 		return err
 	}
 
-	cc.wmu.Lock()
-	defer cc.wmu.Unlock()
+	if !cc.seenSettings {
+		if !seenMaxConcurrentStreams {
+			// This was the servers initial SETTINGS frame and it
+			// didn't contain a MAX_CONCURRENT_STREAMS field so
+			// increase the number of concurrent streams this
+			// connection can establish to our default.
+			cc.maxConcurrentStreams = defaultMaxConcurrentStreams
+		}
+		cc.seenSettings = true
+	}
 
-	cc.fr.WriteSettingsAck()
-	cc.bw.Flush()
-	return cc.werr
+	return nil
 }
 
 func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error {
 	cc := rl.cc
-	cs := cc.streamByID(f.StreamID, false)
+	cs := rl.streamByID(f.StreamID)
 	if f.StreamID != 0 && cs == nil {
 		return nil
 	}
@@ -2411,24 +2886,22 @@
 }
 
 func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error {
-	cs := rl.cc.streamByID(f.StreamID, true)
+	cs := rl.streamByID(f.StreamID)
 	if cs == nil {
-		// TODO: return error if server tries to RST_STEAM an idle stream
+		// TODO: return error if server tries to RST_STREAM an idle stream
 		return nil
 	}
-	select {
-	case <-cs.peerReset:
-		// Already reset.
-		// This is the only goroutine
-		// which closes this, so there
-		// isn't a race.
-	default:
-		err := streamError(cs.ID, f.ErrCode)
-		cs.resetErr = err
-		close(cs.peerReset)
-		cs.bufPipe.CloseWithError(err)
-		cs.cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
+	serr := streamError(cs.ID, f.ErrCode)
+	serr.Cause = errFromPeer
+	if f.ErrCode == ErrCodeProtocol {
+		rl.cc.SetDoNotReuse()
 	}
+	if fn := cs.cc.t.CountError; fn != nil {
+		fn("recv_rststream_" + f.ErrCode.stringToken())
+	}
+	cs.abortStream(serr)
+
+	cs.bufPipe.CloseWithError(serr)
 	return nil
 }
 
@@ -2450,19 +2923,24 @@
 		}
 		cc.mu.Unlock()
 	}
-	cc.wmu.Lock()
-	if err := cc.fr.WritePing(false, p); err != nil {
-		cc.wmu.Unlock()
-		return err
-	}
-	if err := cc.bw.Flush(); err != nil {
-		cc.wmu.Unlock()
-		return err
-	}
-	cc.wmu.Unlock()
+	errc := make(chan error, 1)
+	go func() {
+		cc.wmu.Lock()
+		defer cc.wmu.Unlock()
+		if err := cc.fr.WritePing(false, p); err != nil {
+			errc <- err
+			return
+		}
+		if err := cc.bw.Flush(); err != nil {
+			errc <- err
+			return
+		}
+	}()
 	select {
 	case <-c:
 		return nil
+	case err := <-errc:
+		return err
 	case <-ctx.Done():
 		return ctx.Err()
 	case <-cc.readerDone:
@@ -2537,7 +3015,17 @@
 	log.Printf(format, args...)
 }
 
-var noBody io.ReadCloser = ioutil.NopCloser(bytes.NewReader(nil))
+var noBody io.ReadCloser = noBodyReader{}
+
+type noBodyReader struct{}
+
+func (noBodyReader) Close() error             { return nil }
+func (noBodyReader) Read([]byte) (int, error) { return 0, io.EOF }
+
+type missingBody struct{}
+
+func (missingBody) Close() error             { return nil }
+func (missingBody) Read([]byte) (int, error) { return 0, io.ErrUnexpectedEOF }
 
 func strSliceContains(ss []string, s string) bool {
 	for _, v := range ss {
@@ -2577,94 +3065,17 @@
 }
 
 func (gz *gzipReader) Close() error {
-	return gz.body.Close()
+	if err := gz.body.Close(); err != nil {
+		return err
+	}
+	gz.zerr = fs.ErrClosed
+	return nil
 }
 
 type errorReader struct{ err error }
 
 func (r errorReader) Read(p []byte) (int, error) { return 0, r.err }
 
-// bodyWriterState encapsulates various state around the Transport's writing
-// of the request body, particularly regarding doing delayed writes of the body
-// when the request contains "Expect: 100-continue".
-type bodyWriterState struct {
-	cs     *clientStream
-	timer  *time.Timer   // if non-nil, we're doing a delayed write
-	fnonce *sync.Once    // to call fn with
-	fn     func()        // the code to run in the goroutine, writing the body
-	resc   chan error    // result of fn's execution
-	delay  time.Duration // how long we should delay a delayed write for
-}
-
-func (t *Transport) getBodyWriterState(cs *clientStream, body io.Reader) (s bodyWriterState) {
-	s.cs = cs
-	if body == nil {
-		return
-	}
-	resc := make(chan error, 1)
-	s.resc = resc
-	s.fn = func() {
-		cs.cc.mu.Lock()
-		cs.startedWrite = true
-		cs.cc.mu.Unlock()
-		resc <- cs.writeRequestBody(body, cs.req.Body)
-	}
-	s.delay = t.expectContinueTimeout()
-	if s.delay == 0 ||
-		!httpguts.HeaderValuesContainsToken(
-			cs.req.Header["Expect"],
-			"100-continue") {
-		return
-	}
-	s.fnonce = new(sync.Once)
-
-	// Arm the timer with a very large duration, which we'll
-	// intentionally lower later. It has to be large now because
-	// we need a handle to it before writing the headers, but the
-	// s.delay value is defined to not start until after the
-	// request headers were written.
-	const hugeDuration = 365 * 24 * time.Hour
-	s.timer = time.AfterFunc(hugeDuration, func() {
-		s.fnonce.Do(s.fn)
-	})
-	return
-}
-
-func (s bodyWriterState) cancel() {
-	if s.timer != nil {
-		if s.timer.Stop() {
-			s.resc <- nil
-		}
-	}
-}
-
-func (s bodyWriterState) on100() {
-	if s.timer == nil {
-		// If we didn't do a delayed write, ignore the server's
-		// bogus 100 continue response.
-		return
-	}
-	s.timer.Stop()
-	go func() { s.fnonce.Do(s.fn) }()
-}
-
-// scheduleBodyWrite starts writing the body, either immediately (in
-// the common case) or after the delay timeout. It should not be
-// called until after the headers have been written.
-func (s bodyWriterState) scheduleBodyWrite() {
-	if s.timer == nil {
-		// We're not doing a delayed write (see
-		// getBodyWriterState), so just start the writing
-		// goroutine immediately.
-		go s.fn()
-		return
-	}
-	traceWait100Continue(s.cs.trace)
-	if s.timer.Stop() {
-		s.timer.Reset(s.delay)
-	}
-}
-
 // isConnectionCloseRequest reports whether req should use its own
 // connection for a single request and then close the connection.
 func isConnectionCloseRequest(req *http.Request) bool {
@@ -2722,7 +3133,7 @@
 	cc.mu.Lock()
 	ci.WasIdle = len(cc.streams) == 0 && reused
 	if ci.WasIdle && !cc.lastActive.IsZero() {
-		ci.IdleTime = time.Now().Sub(cc.lastActive)
+		ci.IdleTime = time.Since(cc.lastActive)
 	}
 	cc.mu.Unlock()
 
diff --git a/vendor/golang.org/x/net/http2/write.go b/vendor/golang.org/x/net/http2/write.go
index 3849bc2..33f6139 100644
--- a/vendor/golang.org/x/net/http2/write.go
+++ b/vendor/golang.org/x/net/http2/write.go
@@ -341,7 +341,12 @@
 	}
 	for _, k := range keys {
 		vv := h[k]
-		k = lowerHeader(k)
+		k, ascii := lowerHeader(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		if !validWireHeaderFieldName(k) {
 			// Skip it as backup paranoia. Per
 			// golang.org/issue/14048, these should
diff --git a/vendor/golang.org/x/net/http2/writesched.go b/vendor/golang.org/x/net/http2/writesched.go
index f24d2b1..c7cd001 100644
--- a/vendor/golang.org/x/net/http2/writesched.go
+++ b/vendor/golang.org/x/net/http2/writesched.go
@@ -32,7 +32,8 @@
 
 	// Pop dequeues the next frame to write. Returns false if no frames can
 	// be written. Frames with a given wr.StreamID() are Pop'd in the same
-	// order they are Push'd. No frames should be discarded except by CloseStream.
+	// order they are Push'd, except RST_STREAM frames. No frames should be
+	// discarded except by CloseStream.
 	Pop() (wr FrameWriteRequest, ok bool)
 }
 
@@ -52,6 +53,7 @@
 
 	// stream is the stream on which this frame will be written.
 	// nil for non-stream frames like PING and SETTINGS.
+	// nil for RST_STREAM streams, which use the StreamError.StreamID field instead.
 	stream *stream
 
 	// done, if non-nil, must be a buffered channel with space for
diff --git a/vendor/golang.org/x/net/http2/writesched_priority.go b/vendor/golang.org/x/net/http2/writesched_priority.go
index 2618b2c..0a242c6 100644
--- a/vendor/golang.org/x/net/http2/writesched_priority.go
+++ b/vendor/golang.org/x/net/http2/writesched_priority.go
@@ -383,16 +383,15 @@
 
 func (ws *priorityWriteScheduler) Push(wr FrameWriteRequest) {
 	var n *priorityNode
-	if id := wr.StreamID(); id == 0 {
+	if wr.isControl() {
 		n = &ws.root
 	} else {
+		id := wr.StreamID()
 		n = ws.nodes[id]
 		if n == nil {
 			// id is an idle or closed stream. wr should not be a HEADERS or
-			// DATA frame. However, wr can be a RST_STREAM. In this case, we
-			// push wr onto the root, rather than creating a new priorityNode,
-			// since RST_STREAM is tiny and the stream's priority is unknown
-			// anyway. See issue #17919.
+			// DATA frame. In other case, we push wr onto the root, rather
+			// than creating a new priorityNode.
 			if wr.DataSize() > 0 {
 				panic("add DATA on non-open stream")
 			}
diff --git a/vendor/golang.org/x/net/http2/writesched_random.go b/vendor/golang.org/x/net/http2/writesched_random.go
index 9a7b9e5..f2e55e0 100644
--- a/vendor/golang.org/x/net/http2/writesched_random.go
+++ b/vendor/golang.org/x/net/http2/writesched_random.go
@@ -45,11 +45,11 @@
 }
 
 func (ws *randomWriteScheduler) Push(wr FrameWriteRequest) {
-	id := wr.StreamID()
-	if id == 0 {
+	if wr.isControl() {
 		ws.zero.push(wr)
 		return
 	}
+	id := wr.StreamID()
 	q, ok := ws.sq[id]
 	if !ok {
 		q = ws.queuePool.get()
@@ -59,7 +59,7 @@
 }
 
 func (ws *randomWriteScheduler) Pop() (FrameWriteRequest, bool) {
-	// Control frames first.
+	// Control and RST_STREAM frames first.
 	if !ws.zero.empty() {
 		return ws.zero.shift(), true
 	}
diff --git a/vendor/golang.org/x/net/idna/go118.go b/vendor/golang.org/x/net/idna/go118.go
new file mode 100644
index 0000000..c5c4338
--- /dev/null
+++ b/vendor/golang.org/x/net/idna/go118.go
@@ -0,0 +1,14 @@
+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.18
+// +build go1.18
+
+package idna
+
+// Transitional processing is disabled by default in Go 1.18.
+// https://golang.org/issue/47510
+const transitionalLookup = false
diff --git a/vendor/golang.org/x/net/idna/idna10.0.0.go b/vendor/golang.org/x/net/idna/idna10.0.0.go
index 7e69ee1..64ccf85 100644
--- a/vendor/golang.org/x/net/idna/idna10.0.0.go
+++ b/vendor/golang.org/x/net/idna/idna10.0.0.go
@@ -59,23 +59,22 @@
 // Transitional sets a Profile to use the Transitional mapping as defined in UTS
 // #46. This will cause, for example, "ß" to be mapped to "ss". Using the
 // transitional mapping provides a compromise between IDNA2003 and IDNA2008
-// compatibility. It is used by most browsers when resolving domain names. This
+// compatibility. It is used by some browsers when resolving domain names. This
 // option is only meaningful if combined with MapForLookup.
 func Transitional(transitional bool) Option {
-	return func(o *options) { o.transitional = true }
+	return func(o *options) { o.transitional = transitional }
 }
 
 // VerifyDNSLength sets whether a Profile should fail if any of the IDN parts
 // are longer than allowed by the RFC.
+//
+// This option corresponds to the VerifyDnsLength flag in UTS #46.
 func VerifyDNSLength(verify bool) Option {
 	return func(o *options) { o.verifyDNSLength = verify }
 }
 
 // RemoveLeadingDots removes leading label separators. Leading runes that map to
 // dots, such as U+3002 IDEOGRAPHIC FULL STOP, are removed as well.
-//
-// This is the behavior suggested by the UTS #46 and is adopted by some
-// browsers.
 func RemoveLeadingDots(remove bool) Option {
 	return func(o *options) { o.removeLeadingDots = remove }
 }
@@ -83,6 +82,8 @@
 // ValidateLabels sets whether to check the mandatory label validation criteria
 // as defined in Section 5.4 of RFC 5891. This includes testing for correct use
 // of hyphens ('-'), normalization, validity of runes, and the context rules.
+// In particular, ValidateLabels also sets the CheckHyphens and CheckJoiners flags
+// in UTS #46.
 func ValidateLabels(enable bool) Option {
 	return func(o *options) {
 		// Don't override existing mappings, but set one that at least checks
@@ -91,25 +92,48 @@
 			o.mapping = normalize
 		}
 		o.trie = trie
-		o.validateLabels = enable
-		o.fromPuny = validateFromPunycode
+		o.checkJoiners = enable
+		o.checkHyphens = enable
+		if enable {
+			o.fromPuny = validateFromPunycode
+		} else {
+			o.fromPuny = nil
+		}
+	}
+}
+
+// CheckHyphens sets whether to check for correct use of hyphens ('-') in
+// labels. Most web browsers do not have this option set, since labels such as
+// "r3---sn-apo3qvuoxuxbt-j5pe" are in common use.
+//
+// This option corresponds to the CheckHyphens flag in UTS #46.
+func CheckHyphens(enable bool) Option {
+	return func(o *options) { o.checkHyphens = enable }
+}
+
+// CheckJoiners sets whether to check the ContextJ rules as defined in Appendix
+// A of RFC 5892, concerning the use of joiner runes.
+//
+// This option corresponds to the CheckJoiners flag in UTS #46.
+func CheckJoiners(enable bool) Option {
+	return func(o *options) {
+		o.trie = trie
+		o.checkJoiners = enable
 	}
 }
 
 // StrictDomainName limits the set of permissible ASCII characters to those
 // allowed in domain names as defined in RFC 1034 (A-Z, a-z, 0-9 and the
-// hyphen). This is set by default for MapForLookup and ValidateForRegistration.
+// hyphen). This is set by default for MapForLookup and ValidateForRegistration,
+// but is only useful if ValidateLabels is set.
 //
 // This option is useful, for instance, for browsers that allow characters
 // outside this range, for example a '_' (U+005F LOW LINE). See
-// http://www.rfc-editor.org/std/std3.txt for more details This option
-// corresponds to the UseSTD3ASCIIRules option in UTS #46.
+// http://www.rfc-editor.org/std/std3.txt for more details.
+//
+// This option corresponds to the UseSTD3ASCIIRules flag in UTS #46.
 func StrictDomainName(use bool) Option {
-	return func(o *options) {
-		o.trie = trie
-		o.useSTD3Rules = use
-		o.fromPuny = validateFromPunycode
-	}
+	return func(o *options) { o.useSTD3Rules = use }
 }
 
 // NOTE: the following options pull in tables. The tables should not be linked
@@ -117,6 +141,8 @@
 
 // BidiRule enables the Bidi rule as defined in RFC 5893. Any application
 // that relies on proper validation of labels should include this rule.
+//
+// This option corresponds to the CheckBidi flag in UTS #46.
 func BidiRule() Option {
 	return func(o *options) { o.bidirule = bidirule.ValidString }
 }
@@ -152,7 +178,8 @@
 type options struct {
 	transitional      bool
 	useSTD3Rules      bool
-	validateLabels    bool
+	checkHyphens      bool
+	checkJoiners      bool
 	verifyDNSLength   bool
 	removeLeadingDots bool
 
@@ -225,8 +252,11 @@
 	if p.useSTD3Rules {
 		s += ":UseSTD3Rules"
 	}
-	if p.validateLabels {
-		s += ":ValidateLabels"
+	if p.checkHyphens {
+		s += ":CheckHyphens"
+	}
+	if p.checkJoiners {
+		s += ":CheckJoiners"
 	}
 	if p.verifyDNSLength {
 		s += ":VerifyDNSLength"
@@ -254,26 +284,29 @@
 
 	punycode = &Profile{}
 	lookup   = &Profile{options{
-		transitional:   true,
-		useSTD3Rules:   true,
-		validateLabels: true,
-		trie:           trie,
-		fromPuny:       validateFromPunycode,
-		mapping:        validateAndMap,
-		bidirule:       bidirule.ValidString,
+		transitional: transitionalLookup,
+		useSTD3Rules: true,
+		checkHyphens: true,
+		checkJoiners: true,
+		trie:         trie,
+		fromPuny:     validateFromPunycode,
+		mapping:      validateAndMap,
+		bidirule:     bidirule.ValidString,
 	}}
 	display = &Profile{options{
-		useSTD3Rules:   true,
-		validateLabels: true,
-		trie:           trie,
-		fromPuny:       validateFromPunycode,
-		mapping:        validateAndMap,
-		bidirule:       bidirule.ValidString,
+		useSTD3Rules: true,
+		checkHyphens: true,
+		checkJoiners: true,
+		trie:         trie,
+		fromPuny:     validateFromPunycode,
+		mapping:      validateAndMap,
+		bidirule:     bidirule.ValidString,
 	}}
 	registration = &Profile{options{
 		useSTD3Rules:    true,
-		validateLabels:  true,
 		verifyDNSLength: true,
+		checkHyphens:    true,
+		checkJoiners:    true,
 		trie:            trie,
 		fromPuny:        validateFromPunycode,
 		mapping:         validateRegistration,
@@ -340,7 +373,7 @@
 			}
 			isBidi = isBidi || bidirule.DirectionString(u) != bidi.LeftToRight
 			labels.set(u)
-			if err == nil && p.validateLabels {
+			if err == nil && p.fromPuny != nil {
 				err = p.fromPuny(p, u)
 			}
 			if err == nil {
@@ -681,16 +714,18 @@
 		}
 		return nil
 	}
-	if !p.validateLabels {
+	if p.checkHyphens {
+		if len(s) > 4 && s[2] == '-' && s[3] == '-' {
+			return &labelError{s, "V2"}
+		}
+		if s[0] == '-' || s[len(s)-1] == '-' {
+			return &labelError{s, "V3"}
+		}
+	}
+	if !p.checkJoiners {
 		return nil
 	}
-	trie := p.trie // p.validateLabels is only set if trie is set.
-	if len(s) > 4 && s[2] == '-' && s[3] == '-' {
-		return &labelError{s, "V2"}
-	}
-	if s[0] == '-' || s[len(s)-1] == '-' {
-		return &labelError{s, "V3"}
-	}
+	trie := p.trie // p.checkJoiners is only set if trie is set.
 	// TODO: merge the use of this in the trie.
 	v, sz := trie.lookupString(s)
 	x := info(v)
diff --git a/vendor/golang.org/x/net/idna/idna9.0.0.go b/vendor/golang.org/x/net/idna/idna9.0.0.go
index 7c74563..aae6aac 100644
--- a/vendor/golang.org/x/net/idna/idna9.0.0.go
+++ b/vendor/golang.org/x/net/idna/idna9.0.0.go
@@ -58,23 +58,22 @@
 // Transitional sets a Profile to use the Transitional mapping as defined in UTS
 // #46. This will cause, for example, "ß" to be mapped to "ss". Using the
 // transitional mapping provides a compromise between IDNA2003 and IDNA2008
-// compatibility. It is used by most browsers when resolving domain names. This
+// compatibility. It is used by some browsers when resolving domain names. This
 // option is only meaningful if combined with MapForLookup.
 func Transitional(transitional bool) Option {
-	return func(o *options) { o.transitional = true }
+	return func(o *options) { o.transitional = transitional }
 }
 
 // VerifyDNSLength sets whether a Profile should fail if any of the IDN parts
 // are longer than allowed by the RFC.
+//
+// This option corresponds to the VerifyDnsLength flag in UTS #46.
 func VerifyDNSLength(verify bool) Option {
 	return func(o *options) { o.verifyDNSLength = verify }
 }
 
 // RemoveLeadingDots removes leading label separators. Leading runes that map to
 // dots, such as U+3002 IDEOGRAPHIC FULL STOP, are removed as well.
-//
-// This is the behavior suggested by the UTS #46 and is adopted by some
-// browsers.
 func RemoveLeadingDots(remove bool) Option {
 	return func(o *options) { o.removeLeadingDots = remove }
 }
@@ -82,6 +81,8 @@
 // ValidateLabels sets whether to check the mandatory label validation criteria
 // as defined in Section 5.4 of RFC 5891. This includes testing for correct use
 // of hyphens ('-'), normalization, validity of runes, and the context rules.
+// In particular, ValidateLabels also sets the CheckHyphens and CheckJoiners flags
+// in UTS #46.
 func ValidateLabels(enable bool) Option {
 	return func(o *options) {
 		// Don't override existing mappings, but set one that at least checks
@@ -90,25 +91,48 @@
 			o.mapping = normalize
 		}
 		o.trie = trie
-		o.validateLabels = enable
-		o.fromPuny = validateFromPunycode
+		o.checkJoiners = enable
+		o.checkHyphens = enable
+		if enable {
+			o.fromPuny = validateFromPunycode
+		} else {
+			o.fromPuny = nil
+		}
+	}
+}
+
+// CheckHyphens sets whether to check for correct use of hyphens ('-') in
+// labels. Most web browsers do not have this option set, since labels such as
+// "r3---sn-apo3qvuoxuxbt-j5pe" are in common use.
+//
+// This option corresponds to the CheckHyphens flag in UTS #46.
+func CheckHyphens(enable bool) Option {
+	return func(o *options) { o.checkHyphens = enable }
+}
+
+// CheckJoiners sets whether to check the ContextJ rules as defined in Appendix
+// A of RFC 5892, concerning the use of joiner runes.
+//
+// This option corresponds to the CheckJoiners flag in UTS #46.
+func CheckJoiners(enable bool) Option {
+	return func(o *options) {
+		o.trie = trie
+		o.checkJoiners = enable
 	}
 }
 
 // StrictDomainName limits the set of permissable ASCII characters to those
 // allowed in domain names as defined in RFC 1034 (A-Z, a-z, 0-9 and the
-// hyphen). This is set by default for MapForLookup and ValidateForRegistration.
+// hyphen). This is set by default for MapForLookup and ValidateForRegistration,
+// but is only useful if ValidateLabels is set.
 //
 // This option is useful, for instance, for browsers that allow characters
 // outside this range, for example a '_' (U+005F LOW LINE). See
-// http://www.rfc-editor.org/std/std3.txt for more details This option
-// corresponds to the UseSTD3ASCIIRules option in UTS #46.
+// http://www.rfc-editor.org/std/std3.txt for more details.
+//
+// This option corresponds to the UseSTD3ASCIIRules flag in UTS #46.
 func StrictDomainName(use bool) Option {
-	return func(o *options) {
-		o.trie = trie
-		o.useSTD3Rules = use
-		o.fromPuny = validateFromPunycode
-	}
+	return func(o *options) { o.useSTD3Rules = use }
 }
 
 // NOTE: the following options pull in tables. The tables should not be linked
@@ -116,6 +140,8 @@
 
 // BidiRule enables the Bidi rule as defined in RFC 5893. Any application
 // that relies on proper validation of labels should include this rule.
+//
+// This option corresponds to the CheckBidi flag in UTS #46.
 func BidiRule() Option {
 	return func(o *options) { o.bidirule = bidirule.ValidString }
 }
@@ -152,7 +178,8 @@
 type options struct {
 	transitional      bool
 	useSTD3Rules      bool
-	validateLabels    bool
+	checkHyphens      bool
+	checkJoiners      bool
 	verifyDNSLength   bool
 	removeLeadingDots bool
 
@@ -225,8 +252,11 @@
 	if p.useSTD3Rules {
 		s += ":UseSTD3Rules"
 	}
-	if p.validateLabels {
-		s += ":ValidateLabels"
+	if p.checkHyphens {
+		s += ":CheckHyphens"
+	}
+	if p.checkJoiners {
+		s += ":CheckJoiners"
 	}
 	if p.verifyDNSLength {
 		s += ":VerifyDNSLength"
@@ -255,9 +285,10 @@
 	punycode = &Profile{}
 	lookup   = &Profile{options{
 		transitional:      true,
-		useSTD3Rules:      true,
-		validateLabels:    true,
 		removeLeadingDots: true,
+		useSTD3Rules:      true,
+		checkHyphens:      true,
+		checkJoiners:      true,
 		trie:              trie,
 		fromPuny:          validateFromPunycode,
 		mapping:           validateAndMap,
@@ -265,8 +296,9 @@
 	}}
 	display = &Profile{options{
 		useSTD3Rules:      true,
-		validateLabels:    true,
 		removeLeadingDots: true,
+		checkHyphens:      true,
+		checkJoiners:      true,
 		trie:              trie,
 		fromPuny:          validateFromPunycode,
 		mapping:           validateAndMap,
@@ -274,8 +306,9 @@
 	}}
 	registration = &Profile{options{
 		useSTD3Rules:    true,
-		validateLabels:  true,
 		verifyDNSLength: true,
+		checkHyphens:    true,
+		checkJoiners:    true,
 		trie:            trie,
 		fromPuny:        validateFromPunycode,
 		mapping:         validateRegistration,
@@ -339,7 +372,7 @@
 				continue
 			}
 			labels.set(u)
-			if err == nil && p.validateLabels {
+			if err == nil && p.fromPuny != nil {
 				err = p.fromPuny(p, u)
 			}
 			if err == nil {
@@ -629,16 +662,18 @@
 	if p.bidirule != nil && !p.bidirule(s) {
 		return &labelError{s, "B"}
 	}
-	if !p.validateLabels {
+	if p.checkHyphens {
+		if len(s) > 4 && s[2] == '-' && s[3] == '-' {
+			return &labelError{s, "V2"}
+		}
+		if s[0] == '-' || s[len(s)-1] == '-' {
+			return &labelError{s, "V3"}
+		}
+	}
+	if !p.checkJoiners {
 		return nil
 	}
-	trie := p.trie // p.validateLabels is only set if trie is set.
-	if len(s) > 4 && s[2] == '-' && s[3] == '-' {
-		return &labelError{s, "V2"}
-	}
-	if s[0] == '-' || s[len(s)-1] == '-' {
-		return &labelError{s, "V3"}
-	}
+	trie := p.trie // p.checkJoiners is only set if trie is set.
 	// TODO: merge the use of this in the trie.
 	v, sz := trie.lookupString(s)
 	x := info(v)
diff --git a/vendor/golang.org/x/net/idna/pre_go118.go b/vendor/golang.org/x/net/idna/pre_go118.go
new file mode 100644
index 0000000..3aaccab
--- /dev/null
+++ b/vendor/golang.org/x/net/idna/pre_go118.go
@@ -0,0 +1,12 @@
+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.18
+// +build !go1.18
+
+package idna
+
+const transitionalLookup = true
diff --git a/vendor/golang.org/x/net/idna/punycode.go b/vendor/golang.org/x/net/idna/punycode.go
index 02c7d59..e8e3ac1 100644
--- a/vendor/golang.org/x/net/idna/punycode.go
+++ b/vendor/golang.org/x/net/idna/punycode.go
@@ -49,6 +49,7 @@
 		}
 	}
 	i, n, bias := int32(0), initialN, initialBias
+	overflow := false
 	for pos < len(encoded) {
 		oldI, w := i, int32(1)
 		for k := base; ; k += base {
@@ -60,29 +61,32 @@
 				return "", punyError(encoded)
 			}
 			pos++
-			i += digit * w
-			if i < 0 {
+			i, overflow = madd(i, digit, w)
+			if overflow {
 				return "", punyError(encoded)
 			}
 			t := k - bias
-			if t < tmin {
+			if k <= bias {
 				t = tmin
-			} else if t > tmax {
+			} else if k >= bias+tmax {
 				t = tmax
 			}
 			if digit < t {
 				break
 			}
-			w *= base - t
-			if w >= math.MaxInt32/base {
+			w, overflow = madd(0, w, base-t)
+			if overflow {
 				return "", punyError(encoded)
 			}
 		}
+		if len(output) >= 1024 {
+			return "", punyError(encoded)
+		}
 		x := int32(len(output) + 1)
 		bias = adapt(i-oldI, x, oldI == 0)
 		n += i / x
 		i %= x
-		if n > utf8.MaxRune || len(output) >= 1024 {
+		if n < 0 || n > utf8.MaxRune {
 			return "", punyError(encoded)
 		}
 		output = append(output, 0)
@@ -115,6 +119,7 @@
 	if b > 0 {
 		output = append(output, '-')
 	}
+	overflow := false
 	for remaining != 0 {
 		m := int32(0x7fffffff)
 		for _, r := range s {
@@ -122,8 +127,8 @@
 				m = r
 			}
 		}
-		delta += (m - n) * (h + 1)
-		if delta < 0 {
+		delta, overflow = madd(delta, m-n, h+1)
+		if overflow {
 			return "", punyError(s)
 		}
 		n = m
@@ -141,9 +146,9 @@
 			q := delta
 			for k := base; ; k += base {
 				t := k - bias
-				if t < tmin {
+				if k <= bias {
 					t = tmin
-				} else if t > tmax {
+				} else if k >= bias+tmax {
 					t = tmax
 				}
 				if q < t {
@@ -164,6 +169,15 @@
 	return string(output), nil
 }
 
+// madd computes a + (b * c), detecting overflow.
+func madd(a, b, c int32) (next int32, overflow bool) {
+	p := int64(b) * int64(c)
+	if p > math.MaxInt32-int64(a) {
+		return 0, true
+	}
+	return a + int32(p), false
+}
+
 func decodeDigit(x byte) (digit int32, ok bool) {
 	switch {
 	case '0' <= x && x <= '9':
diff --git a/vendor/golang.org/x/net/trace/histogram.go b/vendor/golang.org/x/net/trace/histogram.go
index 9bf4286..d6c7110 100644
--- a/vendor/golang.org/x/net/trace/histogram.go
+++ b/vendor/golang.org/x/net/trace/histogram.go
@@ -32,7 +32,7 @@
 	valueCount   int64   // number of values recorded for single value
 }
 
-// AddMeasurement records a value measurement observation to the histogram.
+// addMeasurement records a value measurement observation to the histogram.
 func (h *histogram) addMeasurement(value int64) {
 	// TODO: assert invariant
 	h.sum += value
diff --git a/vendor/golang.org/x/net/trace/trace.go b/vendor/golang.org/x/net/trace/trace.go
index 3ebf6f2..eae2a99 100644
--- a/vendor/golang.org/x/net/trace/trace.go
+++ b/vendor/golang.org/x/net/trace/trace.go
@@ -395,7 +395,7 @@
 }
 
 func (tr *trace) Finish() {
-	elapsed := time.Now().Sub(tr.Start)
+	elapsed := time.Since(tr.Start)
 	tr.mu.Lock()
 	tr.Elapsed = elapsed
 	tr.mu.Unlock()