Keep the colleague's microbu-esp32c5 tree in this repository

obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).

microbu-esp32c5/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 */
+