103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 2012 Tobias Brunner
|
|
* Copyright (C) 2005-2007 Martin Willi
|
|
* Copyright (C) 2005 Jan Hutter
|
|
* Hochschule fuer Technik Rapperswil
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* for more details.
|
|
*/
|
|
|
|
/**
|
|
* @defgroup receiver receiver
|
|
* @{ @ingroup network
|
|
*/
|
|
|
|
#ifndef RECEIVER_H_
|
|
#define RECEIVER_H_
|
|
|
|
typedef struct receiver_t receiver_t;
|
|
|
|
#include <library.h>
|
|
#include <networking/host.h>
|
|
#include <networking/packet.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 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 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.
|
|
* Instead of VersionIdOfSecret, we include a timestamp. This allows us to
|
|
* find out which key was used for cookie creation. Further, we can set a
|
|
* lifetime for the cookie, which allows us to reuse the secret for a longer
|
|
* time.
|
|
* COOKIE = time | sha1( IPi | SPIi | time | secret )
|
|
*
|
|
* The secret is changed after a certain amount of cookies sent. The old
|
|
* secret is stored to allow a clean migration between secret changes.
|
|
*
|
|
* Further, the number of half-initiated IKE_SAs is limited per peer. This
|
|
* 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 *this);
|
|
};
|
|
|
|
/**
|
|
* Create a receiver_t object.
|
|
*
|
|
* The receiver thread will start working, get data
|
|
* from the socket and add those packets to the job queue.
|
|
*
|
|
* @return receiver_t object, NULL if initialization fails
|
|
*/
|
|
receiver_t * receiver_create(void);
|
|
|
|
#endif /** RECEIVER_H_ @}*/
|