From 5bddd84faea6e9b2fabff92ac50773e0a3dd5246 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 18 Feb 2017 12:38:55 +0700
Subject: [PATCH] allow inter-frame padding

fixes #416
---
 packet_unpacker.go      |  6 +++---
 packet_unpacker_test.go | 20 +++++++++++++++++---
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/packet_unpacker.go b/packet_unpacker.go
index cec85ed7..f6fcc2cb 100644
--- a/packet_unpacker.go
+++ b/packet_unpacker.go
@@ -33,9 +33,11 @@ func (u *packetUnpacker) Unpack(publicHeaderBinary []byte, hdr *PublicHeader, da
 	fs := make([]frames.Frame, 0, 2)
 
 	// Read all frames in the packet
-ReadLoop:
 	for r.Len() > 0 {
 		typeByte, _ := r.ReadByte()
+		if typeByte == 0x0 { // PADDING frame
+			continue
+		}
 		r.UnreadByte()
 
 		var frame frames.Frame
@@ -53,8 +55,6 @@ ReadLoop:
 			err = errors.New("unimplemented: CONGESTION_FEEDBACK")
 		} else {
 			switch typeByte {
-			case 0x0: // PAD, end of frames
-				break ReadLoop
 			case 0x01:
 				frame, err = frames.ParseRstStreamFrame(r)
 				if err != nil {
diff --git a/packet_unpacker_test.go b/packet_unpacker_test.go
index f98a34ae..c0735bde 100644
--- a/packet_unpacker_test.go
+++ b/packet_unpacker_test.go
@@ -48,7 +48,7 @@ var _ = Describe("Packet unpacker", func() {
 		Expect(packet.frames).To(Equal([]frames.Frame{f}))
 	})
 
-	It("unpacks stream frames", func() {
+	It("unpacks STREAM frames", func() {
 		f := &frames.StreamFrame{
 			StreamID: 1,
 			Data:     []byte("foobar"),
@@ -84,13 +84,27 @@ var _ = Describe("Packet unpacker", func() {
 		Expect(err).To(MatchError("unimplemented: CONGESTION_FEEDBACK"))
 	})
 
-	It("handles pad frames", func() {
-		setData([]byte{0, 0, 0})
+	It("handles PADDING frames", func() {
+		setData([]byte{0, 0, 0}) // 3 bytes PADDING
 		packet, err := unpacker.Unpack(hdrBin, hdr, data)
 		Expect(err).ToNot(HaveOccurred())
 		Expect(packet.frames).To(BeEmpty())
 	})
 
+	It("handles PADDING between two other frames", func() {
+		f := &frames.PingFrame{}
+		err := f.Write(buf, protocol.VersionWhatever)
+		Expect(err).ToNot(HaveOccurred())
+		_, err = buf.Write(bytes.Repeat([]byte{0}, 10)) // 10 bytes PADDING
+		Expect(err).ToNot(HaveOccurred())
+		err = f.Write(buf, protocol.VersionWhatever)
+		Expect(err).ToNot(HaveOccurred())
+		setData(buf.Bytes())
+		packet, err := unpacker.Unpack(hdrBin, hdr, data)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(packet.frames).To(HaveLen(2))
+	})
+
 	It("unpacks RST_STREAM frames", func() {
 		setData([]byte{0x01, 0xEF, 0xBE, 0xAD, 0xDE, 0x44, 0x33, 0x22, 0x11, 0xAD, 0xFB, 0xCA, 0xDE, 0x34, 0x12, 0x37, 0x13})
 		packet, err := unpacker.Unpack(hdrBin, hdr, data)