Accept proxy protocol from other nodes

proxy/proxy_test.go

@@ -76,3 +76,44 @@ func TestBuildProxyProtocolHeaderUnknownType(t *testing.T) {
 		t.Errorf("Expected %q, got %q", expected, result)
 	}
 }
+
+func TestBuildProxyProtocolHeaderFromInfo(t *testing.T) {
+	proxy, err := NewSNIProxy(8443, "", "", "127.0.0.1", 443, nil, true, nil)
+	if err != nil {
+		t.Fatalf("Failed to create SNI proxy: %v", err)
+	}
+
+	// Test IPv4 case
+	proxyInfo := &ProxyProtocolInfo{
+		Protocol: "TCP4",
+		SrcIP:    "10.0.0.1",
+		DestIP:   "192.168.1.100",
+		SrcPort:  12345,
+		DestPort: 443,
+	}
+
+	targetAddr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:8080")
+	header := proxy.buildProxyProtocolHeaderFromInfo(proxyInfo, targetAddr)
+
+	expected := "PROXY TCP4 10.0.0.1 127.0.0.1 12345 8080\r\n"
+	if header != expected {
+		t.Errorf("Expected header '%s', got '%s'", expected, header)
+	}
+
+	// Test IPv6 case
+	proxyInfo = &ProxyProtocolInfo{
+		Protocol: "TCP6",
+		SrcIP:    "2001:db8::1",
+		DestIP:   "2001:db8::2",
+		SrcPort:  12345,
+		DestPort: 443,
+	}
+
+	targetAddr, _ = net.ResolveTCPAddr("tcp6", "[::1]:8080")
+	header = proxy.buildProxyProtocolHeaderFromInfo(proxyInfo, targetAddr)
+
+	expected = "PROXY TCP6 2001:db8::1 ::1 12345 8080\r\n"
+	if header != expected {
+		t.Errorf("Expected header '%s', got '%s'", expected, header)
+	}
+}