Keep vanetza-idf in obu-firmware, so a plain clone builds the firmware

obu-firmware builds against the vanetza-idf C-ITS library, which until now
came from the colleague's microbu-esp32c5 tree beside the repository and was
not tracked here, so a clone of this repository could not build the firmware
it ships. The library alone is now part of obu-firmware, as
obu-firmware/external/vanetza-idf: their external/vanetza-idf at commit
cf4b99f, unchanged (9775 files; see its PROVENANCE.md). CMake takes it from
there by default; -DVANETZA_IDF_DIR still points the build elsewhere.

The rest of the colleague's tree (their own VAM firmware, PKI tooling,
station-link Python tools, the V2X2MAP bridge) stays out of this repository
and gitignored; nothing is pushed to their repository. NOTES.md, docs/06,
TODO.md and the pcap verifier's usage line point at the new location.

obu-firmware/external/vanetza-idf/vanetza/btp/port_dispatcher.hpp

@@ -0,0 +1,86 @@
+#ifndef PORT_DISPATCHER_HPP_YZ0UTAUF
+#define PORT_DISPATCHER_HPP_YZ0UTAUF
+
+#include <vanetza/btp/data_interface.hpp>
+#include <vanetza/btp/header.hpp>
+#include <vanetza/common/hook.hpp>
+#include <vanetza/geonet/transport_interface.hpp>
+#include <vanetza/net/packet.hpp>
+#include <list>
+#include <unordered_map>
+
+namespace vanetza
+{
+
+namespace btp
+{
+
+class PortDispatcher : public geonet::TransportInterface
+{
+public:
+    class PromiscuousHook
+    {
+    public:
+        /**
+         * Called when a BTP packet is received, regardless of its destination port
+         * \param indication BTP data indication
+         * \param packet Read-only view of packet
+         */
+        virtual void tap_packet(const DataIndication&, const UpPacket&) = 0;
+        virtual ~PromiscuousHook() {}
+    };
+
+    /**
+     * Register a handler for incoming BTP-A (interactive) packets
+     * \param port BTP-A destination port
+     * \param interface Handler for given destination port
+     * \note Use a nullptr as handler to disable dispatching of destination port
+     * \note Only one handler can be registered per port
+     */
+    void set_interactive_handler(port_type, IndicationInterface*);
+
+    /**
+     * Register a handler for incoming BTP-B (non-interactive) packets
+     * \param port BTP-B destination port
+     * \param interface Handler for given destination port
+     * \note Use a nullptr as handler to disable dispatching of destination port
+     * \note Only one handler can be registered per port
+     */
+    void set_non_interactive_handler(port_type, IndicationInterface*);
+
+    /**
+     * Add a hook listening for all incoming BTP packets
+     * \param hook A hook implementing the promiscuous hook interface
+     * \note Each registered hook is invoked only once per indication
+     */
+    void add_promiscuous_hook(PromiscuousHook* hook);
+
+    /**
+     * Remove promiscuous hook
+     * \param hook pointer to previously added hook
+     */
+    void remove_promiscuous_hook(PromiscuousHook*);
+
+    // Implementation of geonet::TransportInterface
+    void indicate(const geonet::DataIndication&, std::unique_ptr<UpPacket>) override;
+
+    /**
+     * Hook invoked for all indicated but undispatched packets
+     * \note BTP data indication can be nullptr
+     */
+    Hook<const geonet::DataIndication&, const btp::DataIndication*> hook_undispatched;
+
+private:
+    typedef std::unordered_map<port_type, IndicationInterface*> port_map;
+    typedef std::list<PromiscuousHook*> hook_list;
+
+    port_map m_interactive_handlers;
+    port_map m_non_interactive_handlers;
+    hook_list m_promiscuous_hooks;
+};
+
+} // namespace btp
+} // namespace vanetza
+
+#endif /* PORT_DISPATCHER_HPP_YZ0UTAUF */
+