From 513869008c56724f86f98f265ecfe744aff370d6 Mon Sep 17 00:00:00 2001
From: vearne <asdwoshiaotian@gmail.com>
Date: Mon, 11 Nov 2024 12:08:44 +0800
Subject: [PATCH] update http2/tcp_buffer.go

---
 Makefile                 |  2 +-
 http2/http2.go           |  4 ++--
 http2/tcp_buffer.go      | 28 ++++++++++++++++++++++++++++
 http2/tcp_buffer_test.go | 22 ++++++++++++++++++++++
 4 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index f84e2fd..33cff10 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-VERSION := v0.2.4
+VERSION := v0.2.5
 
 BIN_NAME = grpcr
 CONTAINER = grpcr
diff --git a/http2/http2.go b/http2/http2.go
index 20af38a..100063b 100644
--- a/http2/http2.go
+++ b/http2/http2.go
@@ -152,7 +152,7 @@ func (hc *Http2Conn) deal() {
 		buf := make([]byte, HeaderSize)
 		_, err = io.ReadFull(hc.Reader, buf)
 		if err != nil {
-			slog.Error("Http2Conn.deal, ReadFull:%v", err)
+			slog.Warn("Http2Conn.deal, ReadFull:%v", err)
 			break
 		}
 
@@ -170,7 +170,7 @@ func (hc *Http2Conn) deal() {
 		if fb.Length > 0 {
 			_, err = io.ReadFull(hc.Reader, buf)
 			if err != nil {
-				slog.Error("Http2Conn.deal, ReadFull:%v", err)
+				slog.Warn("Http2Conn.deal, ReadFull:%v", err)
 				break
 			}
 		}
diff --git a/http2/tcp_buffer.go b/http2/tcp_buffer.go
index 9dda887..1728b7a 100644
--- a/http2/tcp_buffer.go
+++ b/http2/tcp_buffer.go
@@ -9,6 +9,8 @@ import (
 	"sync/atomic"
 )
 
+const MaxWindowSize = 65536
+
 type TCPBuffer struct {
 	//The number of bytes of data currently cached
 	size              atomic.Int64
@@ -55,6 +57,14 @@ func (sb *TCPBuffer) AddTCP(tcpPkg *layers.TCP) {
 	slog.Debug("[start]SocketBuffer.addTCP, size:%v, actualCanReadSize:%v, expectedSeq:%v",
 		sb.size.Load(), sb.actualCanReadSize.Load(), sb.expectedSeq)
 
+	// Discard packets outside the sliding window
+	if !validPackage(sb.expectedSeq, MaxWindowSize, tcpPkg.Seq) {
+		slog.Debug("[end]SocketBuffer.addTCP-discard packets outside the sliding window, "+
+			"size:%v, actualCanReadSize:%v, expectedSeq:%v",
+			sb.size.Load(), sb.actualCanReadSize.Load(), sb.expectedSeq)
+		return
+	}
+
 	// duplicate package
 	if sb.List.Get(tcpPkg.Seq) != nil {
 		slog.Debug("[end]SocketBuffer.addTCP-duplicate package, size:%v, actualCanReadSize:%v, expectedSeq:%v",
@@ -91,3 +101,21 @@ func (sb *TCPBuffer) AddTCP(tcpPkg *layers.TCP) {
 	slog.Debug("[end]SocketBuffer.addTCP, size:%v, actualCanReadSize:%v, expectedSeq:%v",
 		sb.size.Load(), sb.actualCanReadSize.Load(), sb.expectedSeq)
 }
+
+func validPackage(expectedSeq uint32, maxWindowSize uint32, pkgSeq uint32) bool {
+	rightBorder := (expectedSeq + maxWindowSize) % math.MaxUint32
+	// case 1: sequence wrap around
+	if rightBorder < expectedSeq {
+		if (pkgSeq <= rightBorder) || (pkgSeq >= expectedSeq) {
+			return true
+		} else {
+			return false
+		}
+	} else { // case 2
+		if pkgSeq >= expectedSeq && pkgSeq <= expectedSeq+maxWindowSize {
+			return true
+		} else {
+			return false
+		}
+	}
+}
diff --git a/http2/tcp_buffer_test.go b/http2/tcp_buffer_test.go
index f8896c7..97005bc 100644
--- a/http2/tcp_buffer_test.go
+++ b/http2/tcp_buffer_test.go
@@ -200,3 +200,25 @@ func TestSocketBufferWrapAround3(t *testing.T) {
 	// assert for nil (good for errors)
 	assert.Nil(t, err)
 }
+
+func TestValidPackage(t *testing.T) {
+	testCases := []struct {
+		expectedSeq   uint32
+		maxWindowSize uint32
+		pkgSeq        uint32
+		expected      bool
+	}{
+		// case 1
+		{4294966995, 10000, 4294967095, true},
+		{4294966995, 10000, 9500, true},
+		{4294966995, 10000, 4294946995, false},
+		// case 2
+		{10000, 10000, 10200, true},
+		{10000, 10000, 3000, false},
+		{10000, 10000, 20300, false},
+	}
+	for _, testCase := range testCases {
+		actual := validPackage(testCase.expectedSeq, testCase.maxWindowSize, testCase.pkgSeq)
+		assert.Equal(t, testCase.expected, actual, "Not consistent with expectations")
+	}
+}