Move IP and IP tunnel code from Sessions into packet analyzers

src/packet_analysis/protocol/gre/GRE.h

@@ -0,0 +1,23 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#pragma once
+
+#include <packet_analysis/Analyzer.h>
+#include <packet_analysis/Component.h>
+
+namespace zeek::packet_analysis::GRE {
+
+class GREAnalyzer : public Analyzer {
+public:
+	GREAnalyzer();
+	~GREAnalyzer() override = default;
+
+	bool AnalyzePacket(size_t len, const uint8_t* data, Packet* packet) override;
+
+	static zeek::packet_analysis::AnalyzerPtr Instantiate()
+		{
+		return std::make_shared<GREAnalyzer>();
+		}
+};
+
+}