chore: go mod tidy

This is a more graceful way to disable ENOBUFS reporting than
bed34f94be

.github/workflows/release.yaml

@@ -1,6 +1,6 @@
 on:
   release:
-    types: [ created ]
+    types: [published]
 
 permissions:
   contents: write
@@ -12,8 +12,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        goos: [ linux ]
-        goarch: [ "386", amd64, arm64 ]
+        goos: [linux]
+        goarch: ["386", amd64, arm64]
     steps:
       - uses: actions/checkout@v4
       - uses: wangyoucao577/go-release-action@v1
@@ -21,6 +21,6 @@ jobs:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           goos: ${{ matrix.goos }}
           goarch: ${{ matrix.goarch }}
-          goversion: "https://go.dev/dl/go1.21.6.linux-amd64.tar.gz"
+          goversion: "https://go.dev/dl/go1.22.0.linux-amd64.tar.gz"
           binary_name: "OpenGFW"
-          extra_files: LICENSE README.md README.zh.md
+          extra_files: LICENSE README.md README.zh.md

README.ja.md

@@ -19,7 +19,7 @@ Telegram グループ: https://t.me/OpGFW
 
 - フル IP/TCP 再アセンブル、各種プロトコルアナライザー
   - HTTP、TLS、QUIC、DNS、SSH、SOCKS4/5、WireGuard、その他多数
-  - Shadowsocks の「完全に暗号化されたトラフィック」の検出など (https://gfw.report/publications/usenixsecurity23/data/paper/paper.pdf)
+  - Shadowsocks の「完全に暗号化されたトラフィック」の検出など (https://gfw.report/publications/usenixsecurity23/en/)
   - トロイの木馬キラー (https://github.com/XTLS/Trojan-killer) に基づくトロイの木馬 (プロキシプロトコル) 検出
   - [WIP] 機械学習に基づくトラフィック分類
 - IPv4 と IPv6 をフルサポート

README.md

@@ -23,7 +23,7 @@ Telegram group: https://t.me/OpGFW
 - Full IP/TCP reassembly, various protocol analyzers
   - HTTP, TLS, QUIC, DNS, SSH, SOCKS4/5, WireGuard, and many more to come
   - "Fully encrypted traffic" detection for Shadowsocks,
-    etc. (https://gfw.report/publications/usenixsecurity23/data/paper/paper.pdf)
+    etc. (https://gfw.report/publications/usenixsecurity23/en/)
   - Trojan (proxy protocol) detection based on Trojan-killer (https://github.com/XTLS/Trojan-killer)
   - [WIP] Machine learning based traffic classification
 - Full IPv4 and IPv6 support

README.zh.md

@@ -19,7 +19,7 @@ Telegram 群组： https://t.me/OpGFW
 
 - 完整的 IP/TCP 重组，各种协议解析器
   - HTTP, TLS, QUIC, DNS, SSH, SOCKS4/5, WireGuard, 更多协议正在开发中
-  - Shadowsocks 等 "全加密流量" 检测 (https://gfw.report/publications/usenixsecurity23/data/paper/paper.pdf)
+  - Shadowsocks 等 "全加密流量" 检测 (https://gfw.report/publications/usenixsecurity23/zh/)
   - 基于 Trojan-killer 的 Trojan 检测 (https://github.com/XTLS/Trojan-killer)
   - [开发中] 基于机器学习的流量分类
 - 同等支持 IPv4 和 IPv6

analyzer/tcp/fet.go

@@ -143,8 +143,11 @@ func isTLSorHTTP(bytes []byte) bool {
 	if len(bytes) < 3 {
 		return false
 	}
-	if bytes[0] == 0x16 && bytes[1] == 0x03 && bytes[2] <= 0x03 {
-		// TLS handshake for TLS 1.0-1.3
+	// "We observe that the GFW exempts any connection whose first
+	// three bytes match the following regular expression:
+	// [\x16-\x17]\x03[\x00-\x09]" - from the paper in Section 4.3
+	if bytes[0] >= 0x16 && bytes[0] <= 0x17 &&
+		bytes[1] == 0x03 && bytes[2] <= 0x09 {
 		return true
 	}
 	// HTTP request

io/nfqueue.go

@@ -127,6 +127,10 @@ func NewNFQueuePacketIO(config NFQueuePacketIOConfig) (PacketIO, error) {
 	if err != nil {
 		return nil, err
 	}
+	err = n.Con.SetOption(netlink.NoENOBUFS, true)
+	if err != nil {
+		return nil, fmt.Errorf("failed to set NoENOBUFS option: %w", err)
+	}
 	return &nfqueuePacketIO{
 		n:     n,
 		local: config.Local,
@@ -138,9 +142,10 @@ func NewNFQueuePacketIO(config NFQueuePacketIOConfig) (PacketIO, error) {
 func (n *nfqueuePacketIO) Register(ctx context.Context, cb PacketCallback) error {
 	err := n.n.RegisterWithErrorFunc(ctx,
 		func(a nfqueue.Attribute) int {
-			if a.PacketID == nil || a.Ct == nil || a.Payload == nil || len(*a.Payload) < 20 {
-				// Invalid packet, ignore
-				// 20 is the minimum possible size of an IP packet
+			if ok, verdict := n.packetAttributeSanityCheck(a); !ok {
+				if a.PacketID != nil {
+					_ = n.n.SetVerdict(*a.PacketID, verdict)
+				}
 				return 0
 			}
 			p := &nfqueuePacket{
@@ -170,6 +175,25 @@ func (n *nfqueuePacketIO) Register(ctx context.Context, cb PacketCallback) error
 	return nil
 }
 
+func (n *nfqueuePacketIO) packetAttributeSanityCheck(a nfqueue.Attribute) (ok bool, verdict int) {
+	if a.PacketID == nil {
+		// Re-inject to NFQUEUE is actually not possible in this condition
+		return false, -1
+	}
+	if a.Payload == nil || len(*a.Payload) < 20 {
+		// 20 is the minimum possible size of an IP packet
+		return false, nfqueue.NfDrop
+	}
+	if a.Ct == nil {
+		// Multicast packets may not have a conntrack, but only appear in local mode
+		if n.local {
+			return false, nfqueue.NfAccept
+		}
+		return false, nfqueue.NfDrop
+	}
+	return true, -1
+}
+
 func (n *nfqueuePacketIO) SetVerdict(p Packet, v Verdict, newPacket []byte) error {
 	nP, ok := p.(*nfqueuePacket)
 	if !ok {