Callback for ESP packets added to receiver.

src/libcharon/network/receiver.h

@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2005-2007 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -25,15 +26,28 @@
 typedef struct receiver_t receiver_t;
 
 #include <library.h>
+#include <network/packet.h>
 #include <utils/host.h>
 
+/**
+ * Callback called for any received UDP encapsulated ESP packet.
+ *
+ * Implementation should be quick as the receiver doesn't receive any packets
+ * while calling this function.
+ *
+ * @param data			data supplied during registration of the callback
+ * @param packet		decapsulated ESP packet
+ */
+typedef void (*receiver_esp_cb_t)(void *data, packet_t *packet);
+
 /**
  * Receives packets from the socket and adds them to the job queue.
  *
- * The receiver starts a thread, which reads on the blocking socket. A received
- * packet is preparsed and a process_message_job is queued in the job queue.
+ * The receiver uses a callback job, which reads on the blocking socket.
+ * A received packet is preparsed and a process_message_job is queued in the
+ * job queue.
  *
- * To endure DoS attacks, cookies are enabled when to many IKE_SAs are half
+ * To endure DoS attacks, cookies are enabled when too many IKE_SAs are half
  * open. The calculation of cookies is slightly different from the proposed
  * method in RFC4306. We do not include a nonce, because we think the advantage
  * we gain does not justify the overhead to parse the whole message.
@@ -47,14 +61,32 @@ typedef struct receiver_t receiver_t;
  * secret is stored to allow a clean migration between secret changes.
  *
  * Further, the number of half-initiated IKE_SAs is limited per peer. This
- * mades it impossible for a peer to flood the server with its real IP address.
+ * makes it impossible for a peer to flood the server with its real IP address.
  */
 struct receiver_t {
 
+	/**
+	 * Register a callback which is called for any incoming ESP packets.
+	 *
+	 * @note Only the last callback registered will receive any packets.
+	 *
+	 * @param callback		callback to register
+	 * @param data			data provided to callback
+	 */
+	void (*add_esp_cb)(receiver_t *this, receiver_esp_cb_t callback,
+					   void *data);
+
+	/**
+	 * Unregister a previously registered callback for ESP packets.
+	 *
+	 * @param callback		previously registered callback
+	 */
+	void (*del_esp_cb)(receiver_t *this, receiver_esp_cb_t callback);
+
 	/**
 	 * Destroys a receiver_t object.
 	 */
-	void (*destroy) (receiver_t *receiver);
+	void (*destroy)(receiver_t *this);
 };
 
 /**