Merge branch 'android-app'

This branch introduces a userland IPsec implementation (libipsec) and an
Android App which targets the VpnService API that is provided by Android 4+.

The implementation is based on the bachelor thesis 'Userland IPsec for
Android 4' by Giuliano Grassi and Ralf Sager.

src/libstrongswan/utils/blocking_queue.c

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2012 Giuliano Grassi
+ * Copyright (C) 2012 Ralf Sager
+ * 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.
+ */
+
+#include "blocking_queue.h"
+
+#include <threading/mutex.h>
+#include <threading/thread.h>
+#include <threading/condvar.h>
+#include <utils/linked_list.h>
+
+typedef struct private_blocking_queue_t private_blocking_queue_t;
+
+/**
+ * Private data of a blocking_queue_t object.
+ */
+struct private_blocking_queue_t {
+
+	/**
+	 * Public part
+	 */
+	blocking_queue_t public;
+
+	/**
+	 * Linked list containing all items in the queue
+	 */
+	linked_list_t *list;
+
+	/**
+	 * Mutex used to synchronize access to the queue
+	 */
+	mutex_t *mutex;
+
+	/**
+	 * Condvar used to wait for items
+	 */
+	condvar_t *condvar;
+
+};
+
+METHOD(blocking_queue_t, enqueue, void,
+	private_blocking_queue_t *this, void *item)
+{
+	this->mutex->lock(this->mutex);
+	this->list->insert_first(this->list, item);
+	this->condvar->signal(this->condvar);
+	this->mutex->unlock(this->mutex);
+}
+
+METHOD(blocking_queue_t, dequeue, void*,
+	private_blocking_queue_t *this)
+{
+	bool oldstate;
+	void *item;
+
+
+	this->mutex->lock(this->mutex);
+	thread_cleanup_push((thread_cleanup_t)this->mutex->unlock, this->mutex);
+	/* ensure that a canceled thread does not dequeue any items */
+	thread_cancellation_point();
+	while (this->list->remove_last(this->list, &item) != SUCCESS)
+	{
+		oldstate = thread_cancelability(TRUE);
+		this->condvar->wait(this->condvar, this->mutex);
+		thread_cancelability(oldstate);
+	}
+	thread_cleanup_pop(TRUE);
+	return item;
+}
+
+METHOD(blocking_queue_t, destroy, void,
+	private_blocking_queue_t *this)
+{
+	this->list->destroy(this->list);
+	this->condvar->destroy(this->condvar);
+	this->mutex->destroy(this->mutex);
+	free(this);
+}
+
+METHOD(blocking_queue_t, destroy_offset, void,
+	private_blocking_queue_t *this, size_t offset)
+{
+	this->list->invoke_offset(this->list, offset);
+	destroy(this);
+}
+
+METHOD(blocking_queue_t, destroy_function, void,
+	private_blocking_queue_t *this, void (*fn)(void*))
+{
+	this->list->invoke_function(this->list, (linked_list_invoke_t)fn);
+	destroy(this);
+}
+
+/*
+ * Described in header.
+ */
+blocking_queue_t *blocking_queue_create()
+{
+	private_blocking_queue_t *this;
+
+	INIT(this,
+		.public = {
+			.enqueue = _enqueue,
+			.dequeue = _dequeue,
+			.destroy = _destroy,
+			.destroy_offset = _destroy_offset,
+			.destroy_function = _destroy_function,
+		},
+		.list = linked_list_create(),
+		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
+		.condvar = condvar_create(CONDVAR_TYPE_DEFAULT),
+	);
+
+	return &this->public;
+}
+

src/libstrongswan/utils/blocking_queue.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2012 Giuliano Grassi
+ * Copyright (C) 2012 Ralf Sager
+ * 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 blocking_queue blocking_queue
+ * @{ @ingroup utils
+ */
+
+#ifndef BLOCKING_QUEUE_H_
+#define BLOCKING_QUEUE_H_
+
+typedef struct blocking_queue_t blocking_queue_t;
+
+#include <library.h>
+
+/**
+ * Class implementing a synchronized blocking queue based on linked_list_t
+ */
+struct blocking_queue_t {
+
+	/**
+	 * Inserts a new item at the tail of the queue
+	 *
+	 * @param item		item to insert in queue
+	 */
+	void (*enqueue)(blocking_queue_t *this, void *item);
+
+	/**
+	 * Removes the first item in the queue and returns its value.
+	 * If the queue is empty, this call blocks until a new item is inserted.
+	 *
+	 * @note This is a thread cancellation point
+	 *
+	 * @return			removed item
+	 */
+	void *(*dequeue)(blocking_queue_t *this);
+
+	/**
+	 * Destroys a blocking_queue_t object.
+	 *
+	 * @note No thread must wait in dequeue() when this function is called
+	 */
+	void (*destroy)(blocking_queue_t *this);
+
+	/**
+	 * Destroys a queue and its objects using the given destructor.
+	 *
+	 * If a queue and the contained objects should be destroyed, use
+	 * destroy_offset. The supplied offset specifies the destructor to
+	 * call on each object. The offset may be calculated using the offsetof
+	 * macro, e.g.: queue->destroy_offset(queue, offsetof(object_t, destroy));
+	 *
+	 * @note No thread must wait in dequeue() when this function is called
+	 *
+	 * @param offset	offset of the objects destructor
+	 */
+	void (*destroy_offset)(blocking_queue_t *this, size_t offset);
+
+	/**
+	 * Destroys a queue and its objects using a cleanup function.
+	 *
+	 * If a queue and its contents should get destroyed using a specific
+	 * cleanup function, use destroy_function. This is useful when the
+	 * list contains malloc()-ed blocks which should get freed,
+	 * e.g.: queue->destroy_function(queue, free);
+	 *
+	 * @note No thread must wait in dequeue() when this function is called
+	 *
+	 * @param function	function to call on each object
+	 */
+	void (*destroy_function)(blocking_queue_t *this, void (*)(void*));
+
+};
+
+/**
+ * Creates an empty queue object.
+ *
+ * @return		blocking_queue_t object.
+ */
+blocking_queue_t *blocking_queue_create();
+
+#endif /** BLOCKING_QUEUE_H_ @}*/
+

src/libstrongswan/utils/host.c

@@ -110,7 +110,7 @@ int host_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
 	{
 		snprintf(buffer, sizeof(buffer), "(null)");
 	}
-	else if (is_anyaddr(this))
+	else if (is_anyaddr(this) && !spec->plus)
 	{
 		snprintf(buffer, sizeof(buffer), "%%any%s",
 				 this->address.sa_family == AF_INET6 ? "6" : "");

src/libstrongswan/utils/host.h

@@ -155,7 +155,7 @@ struct host_t {
  *
  * @param string		string of an address, such as "152.96.193.130"
  * @param port			port number
- * @return 				host_t, NULL if string not an address.
+ * @return				host_t, NULL if string not an address.
  */
 host_t *host_create_from_string(char *string, u_int16_t port);
 
@@ -165,7 +165,7 @@ host_t *host_create_from_string(char *string, u_int16_t port);
  * @param string		hostname to resolve
  * @param family		family to prefer, 0 for first match
  * @param port			port number
- * @return 				host_t, NULL lookup failed
+ * @return				host_t, NULL lookup failed
  */
 host_t *host_create_from_dns(char *string, int family, u_int16_t port);
 
@@ -174,10 +174,10 @@ host_t *host_create_from_dns(char *string, int family, u_int16_t port);
  *
  * If family is AF_UNSPEC, it is guessed using address.len.
  *
- * @param family 		Address family, such as AF_INET or AF_INET6
+ * @param family		Address family, such as AF_INET or AF_INET6
  * @param address		address as chunk_t in network order
  * @param port			port number
- * @return 				host_t, NULL if family not supported/chunk invalid
+ * @return				host_t, NULL if family not supported/chunk invalid
  */
 host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port);
 
@@ -185,7 +185,7 @@ host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port);
  * Constructor to create a host_t object from a sockaddr struct
  *
  * @param sockaddr		sockaddr struct which contains family, address and port
- * @return 				host_t, NULL if family not supported
+ * @return				host_t, NULL if family not supported
  */
 host_t *host_create_from_sockaddr(sockaddr_t *sockaddr);
 
@@ -202,7 +202,7 @@ host_t *host_create_from_subnet(char *string, int *bits);
  * Create a host without an address, a "any" host.
  *
  * @param family		family of the any host
- * @return 				host_t, NULL if family not supported
+ * @return				host_t, NULL if family not supported
  */
 host_t *host_create_any(int family);
 
@@ -212,6 +212,7 @@ host_t *host_create_any(int family);
  * Arguments are:
  *	host_t *host
  * Use #-modifier to include port number
+ * Use +-modifier to force numeric representation (instead of e.g. %any)
  */
 int host_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
 					 const void *const *args);

src/libstrongswan/utils/packet.c

@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2005-2006 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.
+ */
+
+#include "packet.h"
+
+typedef struct private_packet_t private_packet_t;
+
+/**
+ * Private data of an packet_t object.
+ */
+struct private_packet_t {
+
+	/**
+	 * Public part of a packet_t object.
+	 */
+	packet_t public;
+
+	/**
+	 * source address
+	 */
+	host_t *source;
+
+	/**
+	 * destination address
+	 */
+	host_t *destination;
+
+	 /**
+	  * message data
+	  */
+	chunk_t data;
+
+	/**
+	 * actual chunk returned from get_data, adjusted when skip_bytes is called
+	 */
+	chunk_t adjusted_data;
+};
+
+METHOD(packet_t, set_source, void,
+	private_packet_t *this, host_t *source)
+{
+	DESTROY_IF(this->source);
+	this->source = source;
+}
+
+METHOD(packet_t, set_destination, void,
+	private_packet_t *this, host_t *destination)
+{
+	DESTROY_IF(this->destination);
+	this->destination = destination;
+}
+
+METHOD(packet_t, get_source, host_t*,
+	private_packet_t *this)
+{
+	return this->source;
+}
+
+METHOD(packet_t, get_destination, host_t*,
+	private_packet_t *this)
+{
+	return this->destination;
+}
+
+METHOD(packet_t, get_data, chunk_t,
+	private_packet_t *this)
+{
+	return this->adjusted_data;
+}
+
+METHOD(packet_t, set_data, void,
+	private_packet_t *this, chunk_t data)
+{
+	free(this->data.ptr);
+	this->adjusted_data = this->data = data;
+}
+
+METHOD(packet_t, skip_bytes, void,
+	private_packet_t *this, size_t bytes)
+{
+	this->adjusted_data = chunk_skip(this->adjusted_data, bytes);
+}
+
+METHOD(packet_t, destroy, void,
+	private_packet_t *this)
+{
+	DESTROY_IF(this->source);
+	DESTROY_IF(this->destination);
+	free(this->data.ptr);
+	free(this);
+}
+
+METHOD(packet_t, clone_, packet_t*,
+	private_packet_t *this)
+{
+	packet_t *other;
+
+	other = packet_create();
+	if (this->destination)
+	{
+		other->set_destination(other,
+							   this->destination->clone(this->destination));
+	}
+	if (this->source)
+	{
+		other->set_source(other, this->source->clone(this->source));
+	}
+	if (this->data.ptr)
+	{
+		other->set_data(other, chunk_clone(this->adjusted_data));
+	}
+	return other;
+}
+
+/**
+ * Described in header.
+ */
+packet_t *packet_create_from_data(host_t *src, host_t *dst, chunk_t data)
+{
+	private_packet_t *this;
+
+	INIT(this,
+		.public = {
+			.set_data = _set_data,
+			.get_data = _get_data,
+			.set_source = _set_source,
+			.get_source = _get_source,
+			.set_destination = _set_destination,
+			.get_destination = _get_destination,
+			.skip_bytes = _skip_bytes,
+			.clone = _clone_,
+			.destroy = _destroy,
+		},
+		.source = src,
+		.destination = dst,
+		.adjusted_data = data,
+		.data = data,
+	);
+
+	return &this->public;
+}
+
+/*
+ * Described in header.
+ */
+packet_t *packet_create()
+{
+	return packet_create_from_data(NULL, NULL, chunk_empty);
+}

src/libstrongswan/utils/packet.h

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2005-2006 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 packet packet
+ * @{ @ingroup utils
+ */
+
+#ifndef PACKET_H_
+#define PACKET_H_
+
+typedef struct packet_t packet_t;
+
+#include <library.h>
+#include <utils/host.h>
+
+/**
+ * Abstraction of an IP/UDP-Packet, contains data, sender and receiver.
+ */
+struct packet_t {
+
+	/**
+	 * Set the source address.
+	 *
+	 * @param source	address to set as source (gets owned)
+	 */
+	void (*set_source)(packet_t *packet, host_t *source);
+
+	/**
+	 * Set the destination address.
+	 *
+	 * @param source	address to set as destination (gets owned)
+	 */
+	void (*set_destination)(packet_t *packet, host_t *destination);
+
+	/**
+	 * Get the source address.
+	 *
+	 * @return			source address (internal data)
+	 */
+	host_t *(*get_source)(packet_t *packet);
+
+	/**
+	 * Get the destination address.
+	 *
+	 * @return			destination address (internal data)
+	 */
+	host_t *(*get_destination)(packet_t *packet);
+
+	/**
+	 * Get the data from the packet.
+	 *
+	 * @return			chunk containing the data (internal data)
+	 */
+	chunk_t (*get_data)(packet_t *packet);
+
+	/**
+	 * Set the data in the packet.
+	 *
+	 * @param data		chunk with data to set (gets owned)
+	 */
+	void (*set_data)(packet_t *packet, chunk_t data);
+
+	/**
+	 * Increase the offset where the actual packet data starts.
+	 *
+	 * The total offset applies to future calls of get_data() and clone().
+	 *
+	 * @note The offset is reset to 0 when set_data() is called.
+	 *
+	 * @param bytes		the number of additional bytes to skip
+	 */
+	void (*skip_bytes)(packet_t *packet, size_t bytes);
+
+	/**
+	 * Clones a packet_t object.
+	 *
+	 * @note Data is cloned without skipped bytes.
+	 *
+	 * @param clone		clone of the packet
+	 */
+	packet_t* (*clone)(packet_t *packet);
+
+	/**
+	 * Destroy the packet, freeing contained data.
+	 */
+	void (*destroy)(packet_t *packet);
+};
+
+/**
+ * Create an empty packet
+ *
+ * @return packet_t object
+ */
+packet_t *packet_create();
+
+/**
+ * Create a packet from the supplied data
+ *
+ * @param src			source address (gets owned)
+ * @param dst			destination address (gets owned)
+ * @param data			packet data (gets owned)
+ * @return packet_t object
+ */
+packet_t *packet_create_from_data(host_t *src, host_t *dst, chunk_t data);
+
+#endif /** PACKET_H_ @}*/

src/libstrongswan/utils/tun_device.c

@@ -0,0 +1,353 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2012 Giuliano Grassi
+ * Copyright (C) 2012 Ralf Sager
+ * 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.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+#include "tun_device.h"
+
+#include <library.h>
+#include <debug.h>
+#include <threading/thread.h>
+
+#define TUN_DEFAULT_MTU 1500
+
+typedef struct private_tun_device_t private_tun_device_t;
+
+struct private_tun_device_t {
+
+	/**
+	 * Public interface
+	 */
+	tun_device_t public;
+
+	/**
+	 * The TUN device's file descriptor
+	 */
+	int tunfd;
+
+	/**
+	 * Name of the TUN device
+	 */
+	char if_name[IFNAMSIZ];
+
+	/**
+	 * Socket used for ioctl() to set interface addr, ...
+	 */
+	int sock;
+
+	/**
+	 * The current MTU
+	 */
+	int mtu;
+};
+
+/**
+ * Set the sockaddr_t from the given netmask
+ */
+static void set_netmask(struct ifreq *ifr, int family, u_int8_t netmask)
+{
+	int len, bytes, bits;
+	char *target;
+
+	switch (family)
+	{
+		case AF_INET:
+		{
+			struct sockaddr_in *addr = (struct sockaddr_in*)&ifr->ifr_addr;
+			addr->sin_family = AF_INET;
+			target = (char*)&addr->sin_addr;
+			len = 4;
+			break;
+		}
+		case AF_INET6:
+		{
+			struct sockaddr_in6 *addr = (struct sockaddr_in6*)&ifr->ifr_addr;
+			addr->sin6_family = AF_INET6;
+			target = (char*)&addr->sin6_addr;
+			len = 16;
+			break;
+		}
+		default:
+			return;
+	}
+
+	bytes = (netmask + 7) / 8;
+	bits = (bytes * 8) - netmask;
+
+	memset(target, 0xff, bytes);
+	memset(target + bytes, 0x00, len - bytes);
+	target[bytes - 1] = bits ? (u_int8_t)(0xff << bits) : 0xff;
+}
+
+METHOD(tun_device_t, set_address, bool,
+	private_tun_device_t *this, host_t *addr, u_int8_t netmask)
+{
+	struct ifreq ifr;
+	int family;
+
+	family = addr->get_family(addr);
+	if ((netmask > 32 && family == AF_INET) || netmask > 128)
+	{
+		DBG1(DBG_LIB, "failed to set address on %s: invalid netmask",
+			 this->if_name);
+		return FALSE;
+	}
+
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_name, this->if_name, IFNAMSIZ);
+	memcpy(&ifr.ifr_addr, addr->get_sockaddr(addr), sizeof(sockaddr_t));
+
+	if (ioctl(this->sock, SIOCSIFADDR, &ifr) < 0)
+	{
+		DBG1(DBG_LIB, "failed to set address on %s: %s",
+			 this->if_name, strerror(errno));
+		return FALSE;
+	}
+
+	set_netmask(&ifr, family, netmask);
+
+	if (ioctl(this->sock, SIOCSIFNETMASK, &ifr) < 0)
+	{
+		DBG1(DBG_LIB, "failed to set netmask on %s: %s",
+			 this->if_name, strerror(errno));
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(tun_device_t, up, bool,
+	private_tun_device_t *this)
+{
+	struct ifreq ifr;
+
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_name, this->if_name, IFNAMSIZ);
+
+	if (ioctl(this->sock, SIOCGIFFLAGS, &ifr) < 0)
+	{
+		DBG1(DBG_LIB, "failed to get interface flags for %s: %s", this->if_name,
+			 strerror(errno));
+		return FALSE;
+	}
+
+	ifr.ifr_flags |= IFF_RUNNING | IFF_UP;
+
+	if (ioctl(this->sock, SIOCSIFFLAGS, &ifr) < 0)
+	{
+		DBG1(DBG_LIB, "failed to set interface flags on %s: %s", this->if_name,
+			 strerror(errno));
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(tun_device_t, set_mtu, bool,
+	private_tun_device_t *this, int mtu)
+{
+	struct ifreq ifr;
+
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_name, this->if_name, IFNAMSIZ);
+	ifr.ifr_mtu = mtu;
+
+	if (ioctl(this->sock, SIOCSIFMTU, &ifr) < 0)
+	{
+		return FALSE;
+	}
+	this->mtu = mtu;
+	return TRUE;
+}
+
+METHOD(tun_device_t, get_mtu, int,
+	private_tun_device_t *this)
+{
+	struct ifreq ifr;
+
+	if (this->mtu > 0)
+	{
+		return this->mtu;
+	}
+
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_name, this->if_name, IFNAMSIZ);
+	this->mtu = TUN_DEFAULT_MTU;
+
+	if (ioctl(this->sock, SIOCGIFMTU, &ifr) == 0)
+	{
+		this->mtu = ifr.ifr_mtu;
+	}
+	return this->mtu;
+}
+
+METHOD(tun_device_t, get_name, char*,
+	private_tun_device_t *this)
+{
+	return this->if_name;
+}
+
+METHOD(tun_device_t, write_packet, bool,
+	private_tun_device_t *this, chunk_t packet)
+{
+	ssize_t s;
+
+	s = write(this->tunfd, packet.ptr, packet.len);
+	if (s < 0)
+	{
+		DBG1(DBG_LIB, "failed to write packet to TUN device %s: %s",
+			 this->if_name, strerror(errno));
+		return FALSE;
+	}
+	else if (s != packet.len)
+	{
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(tun_device_t, read_packet, bool,
+	private_tun_device_t *this, chunk_t *packet)
+{
+	ssize_t len;
+	fd_set set;
+	bool old;
+
+	FD_ZERO(&set);
+	FD_SET(this->tunfd, &set);
+
+	old = thread_cancelability(TRUE);
+	len = select(this->tunfd + 1, &set, NULL, NULL, NULL);
+	thread_cancelability(old);
+
+	if (len < 0)
+	{
+		DBG1(DBG_LIB, "select on TUN device %s failed: %s", this->if_name,
+			 strerror(errno));
+		return FALSE;
+	}
+	/* FIXME: this is quite expensive for lots of small packets, copy from
+	 * local buffer instead? */
+	*packet = chunk_alloc(get_mtu(this));
+	len = read(this->tunfd, packet->ptr, packet->len);
+	if (len < 0)
+	{
+		DBG1(DBG_LIB, "reading from TUN device %s failed: %s", this->if_name,
+			 strerror(errno));
+		chunk_free(packet);
+		return FALSE;
+	}
+	packet->len = len;
+	return TRUE;
+}
+
+METHOD(tun_device_t, destroy, void,
+	private_tun_device_t *this)
+{
+	if (this->tunfd > 0)
+	{
+		close(this->tunfd);
+	}
+	if (this->sock > 0)
+	{
+		close(this->sock);
+	}
+	free(this);
+}
+
+/**
+ * Allocate a TUN device
+ */
+static int tun_alloc(char dev[IFNAMSIZ])
+{
+	struct ifreq ifr;
+	int fd;
+
+	fd = open("/dev/net/tun", O_RDWR);
+	if (fd < 0)
+	{
+		DBG1(DBG_LIB, "failed to open /dev/net/tun: %s", strerror(errno));
+		return fd;
+	}
+
+	memset(&ifr, 0, sizeof(ifr));
+
+	/* TUN device, no packet info */
+	ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+
+	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
+
+	if (ioctl(fd, TUNSETIFF, (void*)&ifr) < 0)
+	{
+		DBG1(DBG_LIB, "failed to configure TUN device: %s", strerror(errno));
+		close(fd);
+		return -1;
+	}
+	strncpy(dev, ifr.ifr_name, IFNAMSIZ);
+	return fd;
+}
+
+/*
+ * Described in header
+ */
+tun_device_t *tun_device_create(const char *name_tmpl)
+{
+	private_tun_device_t *this;
+
+	INIT(this,
+		.public = {
+			.read_packet = _read_packet,
+			.write_packet = _write_packet,
+			.get_mtu = _get_mtu,
+			.set_mtu = _set_mtu,
+			.get_name = _get_name,
+			.set_address = _set_address,
+			.up = _up,
+			.destroy = _destroy,
+		},
+		.tunfd = -1,
+		.sock = -1,
+	);
+
+	strncpy(this->if_name, name_tmpl ?: "tun%d", IFNAMSIZ);
+	this->if_name[IFNAMSIZ-1] = '\0';
+
+	this->tunfd = tun_alloc(this->if_name);
+	if (this->tunfd < 0)
+	{
+		destroy(this);
+		return NULL;
+	}
+	DBG1(DBG_LIB, "created TUN device: %s", this->if_name);
+
+	this->sock = socket(AF_INET, SOCK_DGRAM, 0);
+	if (this->sock < 0)
+	{
+		DBG1(DBG_LIB, "failed to open socket to configure TUN device");
+		destroy(this);
+		return NULL;
+	}
+	return &this->public;
+}

src/libstrongswan/utils/tun_device.h

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Copyright (C) 2012 Giuliano Grassi
+ * Copyright (C) 2012 Ralf Sager
+ * 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 tun_device tun_device
+ * @{ @ingroup utils
+ */
+
+#ifndef TUN_DEVICE_H_
+#define TUN_DEVICE_H_
+
+#include <library.h>
+#include <utils/host.h>
+
+typedef struct tun_device_t tun_device_t;
+
+/**
+ * Class to create TUN devices
+ *
+ * Creating such a device requires the CAP_NET_ADMIN capability.
+ *
+ * @note The implementation is currently very Linux specific
+ */
+struct tun_device_t {
+
+	/**
+	 * Read a packet from the TUN device
+	 *
+	 * @note This call blocks until a packet is available. It is a thread
+	 * cancellation point.
+	 *
+	 * @param packet		the packet read from the device
+	 * @return				TRUE if successful
+	 */
+	bool (*read_packet)(tun_device_t *this, chunk_t *packet);
+
+	/**
+	 * Write a packet to the TUN device
+	 *
+	 * @param packet		the packet to write to the TUN device
+	 * @return				TRUE if successful
+	 */
+	bool (*write_packet)(tun_device_t *this, chunk_t packet);
+
+	/**
+	 * Set the IP address of the device
+	 *
+	 * @param addr			the desired interface address
+	 * @param netmask		the netmask to use
+	 * @return				TRUE if operation successful
+	 */
+	bool (*set_address)(tun_device_t *this, host_t *addr, u_int8_t netmask);
+
+	/**
+	 * Bring the TUN device up
+	 *
+	 * @return				TRUE if operation successful
+	 */
+	bool (*up)(tun_device_t *this);
+
+	/**
+	 * Set the MTU for this TUN device
+	 *
+	 * @param mtu			new MTU
+	 * @return				TRUE if operation successful
+	 */
+	bool (*set_mtu)(tun_device_t *this, int mtu);
+
+	/**
+	 * Get the current MTU for this TUN device
+	 *
+	 * @return				current MTU
+	 */
+	int (*get_mtu)(tun_device_t *this);
+
+	/**
+	 * Get the interface name of this device
+	 *
+	 * @return				interface name
+	 */
+	char *(*get_name)(tun_device_t *this);
+
+	/**
+	 * Destroy a tun_device_t
+	 */
+	void (*destroy)(tun_device_t *this);
+
+};
+
+/**
+ * Create a TUN device using the given name template.
+ *
+ * @param name_tmpl			name template, defaults to "tun%d" if not given
+ * @return					TUN device
+ */
+tun_device_t *tun_device_create(const char *name_tmpl);
+
+#endif /** TUN_DEVICE_H_ @}*/