diff --git a/include/linux/connector.h b/include/linux/connector.h
index fc65d21..b9966e6 100644
--- a/include/linux/connector.h
+++ b/include/linux/connector.h
@@ -39,8 +39,10 @@
 #define CN_IDX_V86D			0x4
 #define CN_VAL_V86D_UVESAFB		0x1
 #define CN_IDX_BB			0x5	/* BlackBoard, from the TSP GPL sampling framework */
+#define CN_DST_IDX			0x6
+#define CN_DST_VAL			0x1
 
-#define CN_NETLINK_USERS		6
+#define CN_NETLINK_USERS		7
 
 /*
  * Maximum connector's message size.
diff --git a/include/linux/dst.h b/include/linux/dst.h
new file mode 100644
index 0000000..e26fed8
--- /dev/null
+++ b/include/linux/dst.h
@@ -0,0 +1,587 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifndef __DST_H
+#define __DST_H
+
+#include <linux/types.h>
+#include <linux/connector.h>
+
+#define DST_NAMELEN		32
+#define DST_NAME		"dst"
+
+enum {
+	/* Remove node with given id from storage */
+	DST_DEL_NODE	= 0,
+	/* Add remote node with given id to the storage */
+	DST_ADD_REMOTE,
+	/* Add local node with given id to the storage to be exported and used by remote peers */
+	DST_ADD_EXPORT,
+	/* Crypto initialization command (hash/cipher used to protect the connection) */
+	DST_CRYPTO,
+	/* Security attributes for given connection (permissions for example) */
+	DST_SECURITY,
+	/* Register given node in the block layer subsystem */
+	DST_START,
+	DST_CMD_MAX
+};
+
+struct dst_ctl
+{
+	/* Storage name */
+	char			name[DST_NAMELEN];
+	/* Command flags */
+	__u32			flags;
+	/* Command itself (see above) */
+	__u32			cmd;
+	/* Maximum number of pages per single request in this device */
+	__u32			max_pages;
+	/* Stale/error transaction scanning timeout in milliseconds */
+	__u32			trans_scan_timeout;
+	/* Maximum number of retry sends before completing transaction as broken */
+	__u32			trans_max_retries;
+	/* Storage size */
+	__u64			size;
+};
+
+/* Reply command carries completion status */
+struct dst_ctl_ack
+{
+	struct cn_msg		msg;
+	int			error;
+	int			unused[3];
+};
+
+/*
+ * Unfortunaltely socket address structure is not exported to userspace
+ * and is redefined there.
+ */
+#define SADDR_MAX_DATA	128
+
+struct saddr {
+	/* address family, AF_xxx	*/
+	unsigned short		sa_family;
+	/* 14 bytes of protocol address	*/
+	char			sa_data[SADDR_MAX_DATA];
+	/* Number of bytes used in sa_data */
+	unsigned short		sa_data_len;
+};
+
+/* Address structure */
+struct dst_network_ctl
+{
+	/* Socket type: datagram, stream...*/
+	unsigned int		type;
+	/* Let me guess, is it a Jupiter diameter? */
+	unsigned int		proto;
+	/* Peer's address */
+	struct saddr		addr;
+};
+
+struct dst_crypto_ctl
+{
+	/* Cipher and hash names */
+	char			cipher_algo[DST_NAMELEN];
+	char			hash_algo[DST_NAMELEN];
+
+	/* Key sizes. Can be zero for digest for example */
+	unsigned int		cipher_keysize, hash_keysize;
+	/* Alignment. Calculated by the DST itself. */
+	unsigned int		crypto_attached_size;
+	/* Number of threads to perform crypto operations */
+	int			thread_num;
+};
+
+/* Export security attributes have this bits checked in when client connects */
+#define DST_PERM_READ		(1<<0)
+#define DST_PERM_WRITE		(1<<1)
+
+/*
+ * Right now it is simple model, where each remote address
+ * is assigned to set of permissions it is allowed to perform.
+ * In real world block device does not know anything but
+ * reading and writing, so it should be more than enough.
+ */
+struct dst_secure_user
+{
+	unsigned int		permissions;
+	struct saddr		addr;
+};
+
+/*
+ * Export control command: device to export and network address to accept
+ * clients to work with given device
+ */
+struct dst_export_ctl
+{
+	char			device[DST_NAMELEN];
+	struct dst_network_ctl	ctl;
+};
+
+enum {
+	DST_CFG	= 1, 		/* Request remote configuration */
+	DST_IO,			/* IO command */
+	DST_IO_RESPONSE,	/* IO response */
+	DST_PING,		/* Keepalive message */
+	DST_NCMD_MAX,
+};
+
+struct dst_cmd
+{
+	/* Network command itself, see above */
+	__u32			cmd;
+	/*
+	 * Size of the attached data
+	 * (in most cases, for READ command it means how many bytes were requested)
+	 */
+	__u32			size;
+	/* Crypto size: number of attached bytes with digest/hmac */
+	__u32			csize;
+	/* Here we can carry secret data */
+	__u32			reserved;
+	/* Read/write bits, see how they are encoded in bio structure */
+	__u64			rw;
+	/* BIO flags */
+	__u64			flags;
+	/* Unique command id (like transaction ID) */
+	__u64			id;
+	/* Sector to start IO from */
+	__u64			sector;
+	/* Hash data is placed after this header */
+	__u8			hash[0];
+};
+
+/*
+ * Convert command to/from network byte order.
+ * We do not use hton*() functions, since there is
+ * no 64-bit implementation.
+ */
+static inline void dst_convert_cmd(struct dst_cmd *c)
+{
+	c->cmd = __cpu_to_be32(c->cmd);
+	c->csize = __cpu_to_be32(c->csize);
+	c->size = __cpu_to_be32(c->size);
+	c->sector = __cpu_to_be64(c->sector);
+	c->id = __cpu_to_be64(c->id);
+	c->flags = __cpu_to_be64(c->flags);
+	c->rw = __cpu_to_be64(c->rw);
+}
+
+/* Transaction id */
+typedef __u64 dst_gen_t;
+
+#ifdef __KERNEL__
+
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/device.h>
+#include <linux/mempool.h>
+#include <linux/net.h>
+#include <linux/poll.h>
+#include <linux/rbtree.h>
+
+#ifdef CONFIG_DST_DEBUG
+#define dprintk(f, a...) printk(KERN_NOTICE f, ##a)
+#else
+static inline void __attribute__ ((format (printf, 1, 2)))
+	dprintk(const char *fmt, ...) {}
+#endif
+
+struct dst_node;
+
+struct dst_trans
+{
+	/* DST node we are working with */
+	struct dst_node		*n;
+
+	/* Entry inside transaction tree */
+	struct rb_node		trans_entry;
+
+	/* Merlin kills this transaction when this memory cell equals zero */
+	atomic_t		refcnt;
+
+	/* How this transaction should be processed by crypto engine */
+	short			enc;
+	/* How many times this transaction was resent */
+	short			retries;
+	/* Completion status */
+	int			error;
+
+	/* When did we send it to the remote peer */
+	long			send_time;
+
+	/* My name is...
+	 * Well, computers does not speak, they have unique id instead */
+	dst_gen_t		gen;
+
+	/* Block IO we are working with */
+	struct bio		*bio;
+
+	/* Network command for above block IO request */
+	struct dst_cmd		cmd;
+};
+
+struct dst_crypto_engine
+{
+	/* What should we do with all block requests */
+	struct crypto_hash	*hash;
+	struct crypto_ablkcipher	*cipher;
+
+	/* Pool of pages used to encrypt data into before sending */
+	int			page_num;
+	struct page		**pages;
+
+	/* What to do with current request */
+	int			enc;
+	/* Who we are and where do we go */
+	struct scatterlist	*src, *dst;
+
+	/* Maximum timeout waiting for encryption to be completed */
+	long			timeout;
+	/* IV is a 64-bit sequential counter */
+	u64			iv;
+
+	/* Secret data */
+	void			*private;
+
+	/* Cached temporary data lives here */
+	int			size;
+	void			*data;
+};
+
+struct dst_state
+{
+	/* The main state protection */
+	struct mutex		state_lock;
+
+	/* Polling machinery for sockets */
+	wait_queue_t 		wait;
+	wait_queue_head_t 	*whead;
+	/* Most of events are being waited here */
+	wait_queue_head_t 	thread_wait;
+
+	/* Who owns this? */
+	struct dst_node		*node;
+
+	/* Network address for this state */
+	struct dst_network_ctl	ctl;
+
+	/* Permissions to work with: read-only or rw connection */
+	u32			permissions;
+
+	/* Called when we need to clean private data */
+	void			(* cleanup)(struct dst_state *st);
+
+	/* Used by the server: BIO completion queues BIOs here */
+	struct list_head	request_list;
+	spinlock_t		request_lock;
+
+	/* Guess what? No, it is not number of planets */
+	atomic_t		refcnt;
+
+	/* This flags is set when connection should be dropped */
+	int			need_exit;
+
+	/*
+	 * Socket to work with. Second pointer is used for
+	 * lockless check if socket was changed before performing
+	 * next action (like working with cached polling result)
+	 */
+	struct socket		*socket, *read_socket;
+
+	/* Cached preallocated data */
+	void			*data;
+	unsigned int		size;
+
+	/* Currently processed command */
+	struct dst_cmd		cmd;
+};
+
+struct dst_info
+{
+	/* Device size */
+	u64			size;
+
+	/* Local device name for export devices */
+	char			local[DST_NAMELEN];
+
+	/* Network setup */
+	struct dst_network_ctl	net;
+
+	/* Sysfs bits use this */
+	struct device		device;
+};
+
+struct dst_node
+{
+	struct list_head	node_entry;
+
+	/* Hi, my name is stored here */
+	char			name[DST_NAMELEN];
+	/* My cache name is stored here */
+	char			cache_name[DST_NAMELEN];
+
+	/* Block device attached to given node.
+	 * Only valid for exporting nodes */
+	struct block_device 	*bdev;
+	/* Network state machine for given peer */
+	struct dst_state	*state;
+
+	/* Block IO machinery */
+	struct request_queue	*queue;
+	struct gendisk		*disk;
+
+	/* Number of threads in processing pool */
+	int			thread_num;
+	/* Maximum number of pages in single IO */
+	int			max_pages;
+
+	/* I'm that big in bytes */
+	loff_t			size;
+
+	/* Exported to userspace node information */
+	struct dst_info		*info;
+
+	/*
+	 * Security attribute list.
+	 * Used only by exporting node currently.
+	 */
+	struct list_head	security_list;
+	struct mutex		security_lock;
+
+	/*
+	 * When this unerflows below zero, university collapses.
+	 * But this will not happen, since node will be freed,
+	 * when reference counter reaches zero.
+	 */
+	atomic_t		refcnt;
+
+	/* How precisely should I be started? */
+	int 			(*start)(struct dst_node *);
+
+	/* Crypto capabilities */
+	struct dst_crypto_ctl	crypto;
+	u8			*hash_key;
+	u8			*cipher_key;
+
+	/* Pool of processing thread */
+	struct thread_pool	*pool;
+
+	/* Transaction IDs live here */
+	atomic_long_t		gen;
+
+	/*
+	 * How frequently and how many times transaction
+	 * tree should be scanned to drop stale objects.
+	 */
+	long			trans_scan_timeout;
+	int			trans_max_retries;
+
+	/* Small gnomes live here */
+	struct rb_root		trans_root;
+	struct mutex		trans_lock;
+
+	/*
+	 * Transaction cache/memory pool.
+	 * It is big enough to contain not only transaction
+	 * itself, but additional crypto data (digest/hmac).
+	 */
+	struct kmem_cache	*trans_cache;
+	mempool_t		*trans_pool;
+
+	/* This entity scans transaction tree */
+	struct delayed_work 	trans_work;
+
+	wait_queue_head_t	wait;
+};
+
+/* Kernel representation of the security attribute */
+struct dst_secure
+{
+	struct list_head	sec_entry;
+	struct dst_secure_user	sec;
+};
+
+int dst_process_bio(struct dst_node *n, struct bio *bio);
+
+int dst_node_init_connected(struct dst_node *n, struct dst_network_ctl *r);
+int dst_node_init_listened(struct dst_node *n, struct dst_export_ctl *le);
+
+static inline struct dst_state *dst_state_get(struct dst_state *st)
+{
+	BUG_ON(atomic_read(&st->refcnt) == 0);
+	atomic_inc(&st->refcnt);
+	return st;
+}
+
+void dst_state_put(struct dst_state *st);
+
+struct dst_state *dst_state_alloc(struct dst_node *n);
+int dst_state_socket_create(struct dst_state *st);
+void dst_state_socket_release(struct dst_state *st);
+
+void dst_state_exit_connected(struct dst_state *st);
+
+int dst_state_schedule_receiver(struct dst_state *st);
+
+void dst_dump_addr(struct socket *sk, struct sockaddr *sa, char *str);
+
+static inline void dst_state_lock(struct dst_state *st)
+{
+	mutex_lock(&st->state_lock);
+}
+
+static inline void dst_state_unlock(struct dst_state *st)
+{
+	mutex_unlock(&st->state_lock);
+}
+
+void dst_poll_exit(struct dst_state *st);
+int dst_poll_init(struct dst_state *st);
+
+static inline unsigned int dst_state_poll(struct dst_state *st)
+{
+	unsigned int revents = POLLHUP | POLLERR;
+
+	dst_state_lock(st);
+	if (st->socket)
+		revents = st->socket->ops->poll(NULL, st->socket, NULL);
+	dst_state_unlock(st);
+
+	return revents;
+}
+
+static inline int dst_thread_setup(void *private, void *data)
+{
+	return 0;
+}
+
+void dst_node_put(struct dst_node *n);
+
+static inline struct dst_node *dst_node_get(struct dst_node *n)
+{
+	atomic_inc(&n->refcnt);
+	return n;
+}
+
+int dst_data_recv(struct dst_state *st, void *data, unsigned int size);
+int dst_recv_cdata(struct dst_state *st, void *cdata);
+int dst_data_send_header(struct socket *sock,
+		void *data, unsigned int size, int more);
+
+int dst_send_bio(struct dst_state *st, struct dst_cmd *cmd, struct bio *bio);
+
+int dst_process_io(struct dst_state *st);
+int dst_export_crypto(struct dst_node *n, struct bio *bio);
+int dst_export_send_bio(struct bio *bio);
+int dst_start_export(struct dst_node *n);
+
+int __init dst_export_init(void);
+void dst_export_exit(void);
+
+/* Private structure for export block IO requests */
+struct dst_export_priv
+{
+	struct list_head		request_entry;
+	struct dst_state		*state;
+	struct bio			*bio;
+	struct dst_cmd			cmd;
+};
+
+static inline void dst_trans_get(struct dst_trans *t)
+{
+	atomic_inc(&t->refcnt);
+}
+
+struct dst_trans *dst_trans_search(struct dst_node *node, dst_gen_t gen);
+int dst_trans_remove(struct dst_trans *t);
+int dst_trans_remove_nolock(struct dst_trans *t);
+void dst_trans_put(struct dst_trans *t);
+
+/*
+ * Convert bio into network command.
+ */
+static inline void dst_bio_to_cmd(struct bio *bio, struct dst_cmd *cmd,
+		u32 command, u64 id)
+{
+	cmd->cmd = command;
+	cmd->flags = (bio->bi_flags << BIO_POOL_BITS) >> BIO_POOL_BITS;
+	cmd->rw = bio->bi_rw;
+	cmd->size = bio->bi_size;
+	cmd->csize = 0;
+	cmd->id = id;
+	cmd->sector = bio->bi_sector;
+};
+
+int dst_trans_send(struct dst_trans *t);
+int dst_trans_crypto(struct dst_trans *t);
+
+int dst_node_crypto_init(struct dst_node *n, struct dst_crypto_ctl *ctl);
+void dst_node_crypto_exit(struct dst_node *n);
+
+static inline int dst_need_crypto(struct dst_node *n)
+{
+	struct dst_crypto_ctl *c = &n->crypto;
+	/*
+	 * Logical OR is appropriate here, but boolean one produces
+	 * more optimal code, so it is used instead.
+	 */
+	return (c->hash_algo[0] | c->cipher_algo[0]);
+}
+
+int dst_node_trans_init(struct dst_node *n, unsigned int size);
+void dst_node_trans_exit(struct dst_node *n);
+
+/*
+ * Pool of threads.
+ * Ready list contains threads currently free to be used,
+ * active one contains threads with some work scheduled for them.
+ * Caller can wait in given queue when thread is ready.
+ */
+struct thread_pool
+{
+	int			thread_num;
+	struct mutex		thread_lock;
+	struct list_head	ready_list, active_list;
+
+	wait_queue_head_t	wait;
+};
+
+void thread_pool_del_worker(struct thread_pool *p);
+void thread_pool_del_worker_id(struct thread_pool *p, unsigned int id);
+int thread_pool_add_worker(struct thread_pool *p,
+		char *name,
+		unsigned int id,
+		void *(* init)(void *data),
+		void (* cleanup)(void *data),
+		void *data);
+
+void thread_pool_destroy(struct thread_pool *p);
+struct thread_pool *thread_pool_create(int num, char *name,
+		void *(* init)(void *data),
+		void (* cleanup)(void *data),
+		void *data);
+
+int thread_pool_schedule(struct thread_pool *p,
+		int (* setup)(void *stored_private, void *setup_data),
+		int (* action)(void *stored_private, void *setup_data),
+		void *setup_data, long timeout);
+int thread_pool_schedule_private(struct thread_pool *p,
+		int (* setup)(void *private, void *data),
+		int (* action)(void *private, void *data),
+		void *data, long timeout, void *id);
+
+#endif /* __KERNEL__ */
+#endif /* __DST_H */