initial commit

10 files changed, 992 insertions, 0 deletions

diff --git a/src/client/client.bak b/src/client/client.bak
new file mode 100644
index 0000000..bacfa52
--- /dev/null
+++ b/src/client/client.bak
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+
+#include <math.h>
+
+#include "../include/types.h"
+
+#define FILE_SIZE 721127424
+
+int main(int argc, char *argv[])
+{
+	struct sockaddr_in server;
+	unsigned long addr;
+	int sock;
+
+	// Create socket
+	sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sock < 0)
+	{
+		printf("ERROR: Socket failure\n");
+		return EXIT_FAILURE;
+	}
+
+	addr = inet_addr(HOST);
+	memcpy((char *) &server.sin_addr, &addr, sizeof(addr));
+	server.sin_family = AF_INET; // IPv4
+	server.sin_port = htons(PORT); // set port number
+
+	// Connect to server
+	if (connect(sock, (struct sockaddr*) &server, sizeof(server)) < 0)
+	{
+		printf("ERROR: Connect failure\n");
+		return EXIT_FAILURE;
+	}
+
+	// Set data
+	struct dnbd3_request request;
+	struct dnbd3_reply reply;
+	request.num = 0;
+
+	// Send to server
+	int i;
+	off_t blocks = FILE_SIZE / DNBD3_BLOCK_SIZE;
+	int e = log(DNBD3_BLOCK_SIZE) / log(2); // logarithmus dualis
+
+
+	for (i = 0; i < blocks; i++)
+	{
+		request.num = i << e; // multiplie by e
+		send(sock, (char *) &request, sizeof(request), 0);
+		recv(sock, &reply, DNBD3_BLOCK_SIZE, MSG_WAITALL);
+		write(STDOUT_FILENO, reply.data, DNBD3_BLOCK_SIZE);
+	}
+
+	/* Fetch "rest" bytes */
+	int rest = FILE_SIZE % DNBD3_BLOCK_SIZE;
+	if (rest != 0)
+	{
+		request.num = i * DNBD3_BLOCK_SIZE;
+		send(sock, (char *) &request, sizeof(request), 0);
+		recv(sock, &reply, sizeof(struct dnbd3_reply), MSG_WAITALL);
+		write(STDOUT_FILENO, reply.data, rest);
+	}
+
+	close(sock);
+	return EXIT_SUCCESS;
+}
diff --git a/src/client/client.c b/src/client/client.c
new file mode 100644
index 0000000..87f20d5
--- /dev/null
+++ b/src/client/client.c
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+
+#include "../include/types.h"
+#include "../version.h"
+
+void print_help(char* argv_0)
+{
+	printf("Usage: %s -H <host> -p <port> -d <device>\n", argv_0);
+	printf("Start the DNBD3 client.\n");
+	printf("-H or --host \t\t Host running dnbd3-server.\n");
+	printf("-p or --port \t\t Port used by server.\n");
+	printf("-d or --device \t\t DNBD3 device name.\n");
+	printf("-h or --help \t\t Show this help text and quit.\n");
+	printf("-v or --version \t Show version and quit.\n");
+	exit(EXIT_SUCCESS);
+}
+
+void print_version()
+{
+	printf("Version: %s\n", VERSION_STRING);
+	exit(EXIT_SUCCESS);
+}
+
+int main(int argc, char *argv[])
+{
+	char *host = NULL;
+	char *port = NULL;
+	char *dev = NULL;
+
+	int opt = 0;
+	int longIndex = 0;
+	static const char *optString = "H:p:d:hv?";
+	static const struct option longOpts[] =
+	{
+	{ "host", required_argument, NULL, 'H' },
+	{ "port", required_argument, NULL, 'p' },
+	{ "device", required_argument, NULL, 'd' },
+	{ "help", no_argument, NULL, 'h' },
+	{ "version", no_argument, NULL, 'v' }, };
+
+	opt = getopt_long(argc, argv, optString, longOpts, &longIndex);
+
+	while (opt != -1)
+	{
+		switch (opt)
+		{
+		case 'H':
+			host = optarg;
+			break;
+		case 'p':
+			port = optarg;
+			break;
+		case 'd':
+			dev = optarg;
+			break;
+		case 'h':
+			print_help(argv[0]);
+			break;
+		case 'v':
+			print_version();
+			break;
+		case '?':
+			print_help(argv[0]);
+		}
+		opt = getopt_long(argc, argv, optString, longOpts, &longIndex);
+	}
+
+	if (!host || !port || !dev)
+	{
+		printf("FATAL: Not enough information specified\n");
+		exit(EXIT_FAILURE);
+	}
+
+	int fd;
+	fd = open(dev, O_RDONLY);
+
+	if (ioctl(fd, IOCTL_SET_HOST, host) < 0)
+		printf("ERROR: ioctl not successful\n");
+
+	if (ioctl(fd, IOCTL_SET_PORT, port) < 0)
+		printf("ERROR: ioctl not successful\n");
+
+	if (ioctl(fd, IOCTL_CONNECT) < 0)
+		printf("ERROR: ioctl not successful\n");
+
+	close(fd);
+
+	exit(EXIT_SUCCESS);
+}
diff --git a/src/config.h b/src/config.h
new file mode 100644
index 0000000..ec41da2
--- /dev/null
+++ b/src/config.h
@@ -0,0 +1,9 @@
+#ifndef CONFIG_H_
+#define CONFIG_H_
+
+#define PORT 5003 // TODO: make obsolete
+
+#define KERNEL_SECTOR_SIZE 512
+#define DNBD3_BLOCK_SIZE 4096
+
+#endif /* CONFIG_H_ */
diff --git a/src/include/types.h b/src/include/types.h
new file mode 100644
index 0000000..ea34616
--- /dev/null
+++ b/src/include/types.h
@@ -0,0 +1,30 @@
+#ifndef TYPES_H_
+#define TYPES_H_
+
+#include "../config.h"
+
+#define DNBD_MAGIC  'd'
+
+#define CMD_GET_BLOCK   1
+#define CMD_GET_SIZE    2
+
+#define IOCTL_SET_HOST	_IO(0xab, 1)
+#define IOCTL_SET_PORT	_IO(0xab, 2)
+#define IOCTL_CONNECT	_IO(0xab, 3)
+
+#pragma pack(1)
+typedef struct dnbd3_request {
+	uint16_t cmd;
+	uint64_t offset;
+	uint64_t size;
+} dnbd3_request_t;
+#pragma pack(0)
+
+#pragma pack(1)
+typedef struct dnbd3_reply {
+	uint16_t cmd;
+	uint64_t filesize;
+} dnbd3_reply_t;
+#pragma pack(0)
+
+#endif /* TYPES_H_ */
diff --git a/src/kernel/main.c b/src/kernel/main.c
new file mode 100644
index 0000000..1802b5f
--- /dev/null
+++ b/src/kernel/main.c
@@ -0,0 +1,216 @@
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <net/sock.h>
+
+// Own
+#include "config.h"
+#include "include/types.h"
+
+static int major;
+static struct gendisk *disk;
+static struct request_queue *dnbd3_queue;
+
+DEFINE_SPINLOCK( dnbd3_lock);
+
+static struct socket *_sock;
+static struct dnbd3_request _dnbd3_request;
+static struct dnbd3_reply _dnbd3_reply;
+
+static char* host;
+static char* port;
+
+unsigned int inet_addr(char *str)
+{
+	int a, b, c, d;
+	char arr[4];
+	sscanf(str, "%d.%d.%d.%d", &a, &b, &c, &d);
+	arr[0] = a;
+	arr[1] = b;
+	arr[2] = c;
+	arr[3] = d;
+	return *(unsigned int*) arr;
+}
+
+void connect(void)
+{
+	if (!host || !port)
+	{
+		printk("ERROR: Host or port not set.");
+		return;
+	}
+
+	// initialize socket
+	struct sockaddr_in sin;
+	if (sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &_sock) < 0)
+	{
+		printk("ERROR: dnbd3 couldn't create socket.\n");
+		return;
+	}
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = inet_addr(host);
+	sin.sin_port = htons(simple_strtol(port, NULL, 10));
+	if (kernel_connect(_sock, (struct sockaddr *) &sin, sizeof(sin), 0) < 0)
+	{
+		printk("ERROR: dnbd3 couldn't connect to given host.\n");
+		return;
+	}
+
+	// prepare message
+	struct msghdr msg;
+	struct kvec iov;
+	_sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
+
+	// send request
+	_dnbd3_request.cmd = CMD_GET_SIZE;
+	iov.iov_base = &_dnbd3_request;
+	iov.iov_len = sizeof(_dnbd3_request);
+	kernel_sendmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_request));
+
+	// receive replay
+	iov.iov_base = &_dnbd3_reply;
+	iov.iov_len = sizeof(_dnbd3_reply);
+	kernel_recvmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_reply), msg.msg_flags);
+
+	// set filesize
+	printk("INFO: dnbd3 filesize: %llu\n", _dnbd3_reply.filesize);
+	set_capacity(disk, _dnbd3_reply.filesize >> 9); /* 512 Byte blocks */
+}
+
+void dnbd3_request(struct request_queue *q)
+{
+	if (!_sock)
+		return;
+
+	struct request *req;
+	struct msghdr msg;
+	struct kvec iov;
+
+	_sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
+
+	while ((req = blk_fetch_request(q)) != NULL)
+	{
+		if (req->cmd_type != REQ_TYPE_FS)
+		{
+			if (!__blk_end_request_cur(req, 0))
+				req = blk_fetch_request(q);
+			continue;
+		}
+
+		spin_unlock_irq(q->queue_lock);
+		if (rq_data_dir(req) == READ)
+		{
+			_dnbd3_request.cmd = CMD_GET_BLOCK;
+			_dnbd3_request.offset = blk_rq_pos(req) << 9; // *512
+			_dnbd3_request.size = blk_rq_bytes(req); // blk_rq_bytes() Returns bytes left to complete in the entire request
+
+			// send request
+			iov.iov_base = &_dnbd3_request;
+			iov.iov_len = sizeof(_dnbd3_request);
+			kernel_sendmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_request));
+
+			// receive replay
+			struct req_iterator iter;
+			struct bio_vec *bvec;
+			rq_for_each_segment(bvec, req, iter)
+			{
+				iov.iov_base = kmap(bvec->bv_page) + bvec->bv_offset;
+				iov.iov_len = bvec->bv_len;
+				kernel_recvmsg(_sock, &msg, &iov, 1, bvec->bv_len, msg.msg_flags);
+				kunmap(bvec->bv_page);
+			}
+		}
+
+		spin_lock_irq(q->queue_lock);
+		__blk_end_request_all(req, 0);
+	}
+}
+
+int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
+		unsigned int cmd, unsigned long arg)
+{
+	switch (cmd)
+	{
+	case IOCTL_SET_HOST:
+		host = (char *) arg;
+		break;
+
+	case IOCTL_SET_PORT:
+		port = (char *) arg;
+		break;
+
+	case IOCTL_CONNECT:
+		connect();
+		break;
+	case BLKFLSBUF:
+		// TODO: if missing, hdparm tells "BLKFLSBUF failed: Operation not permitted". Figure out what this should do.
+		break;
+
+	default:
+		return -1;
+
+	}
+	return 0;
+}
+
+struct block_device_operations dnbd3_ops =
+{ .owner = THIS_MODULE, .ioctl = dnbd3_ioctl, };
+
+static int __init dnbd3_init(void)
+{
+	// Init blkdev
+	if ((major = register_blkdev(0, "dnbd")) == 0)
+	{
+		printk("ERROR: dnbd3 register_blkdev failed.\n");
+		return -EIO;
+	}
+	if (!(disk = alloc_disk(1)))
+	{
+		printk("ERROR: dnbd3 alloc_disk failed.\n");
+		return -EIO;
+	}
+	disk->major = major;
+	disk->first_minor = 0;
+	sprintf(disk->disk_name, "dnbd0");
+	set_capacity(disk, 0);
+	//set_disk_ro(disk, 1);
+	disk->fops = &dnbd3_ops;
+
+	if ((dnbd3_queue = blk_init_queue(&dnbd3_request, &dnbd3_lock)) == NULL)
+	{
+		printk("ERROR: dnbd3 blk_init_queue failed.\n");
+		return -EIO;
+	}
+
+	blk_queue_logical_block_size(dnbd3_queue, DNBD3_BLOCK_SIZE); // set logical block size for the queue
+	disk->queue = dnbd3_queue;
+
+	add_disk(disk);
+	printk("INFO: dnbd3 init successful.\n");
+	return 0;
+}
+
+static void __exit dnbd3_exit(void)
+{
+	if (_sock)
+		sock_release(_sock);
+	unregister_blkdev(major, "dnbd");
+	del_gendisk(disk);
+	put_disk(disk);
+	blk_cleanup_queue(dnbd3_queue);
+	printk("INFO: dnbd3 exit.\n");
+}
+
+module_init( dnbd3_init);
+module_exit( dnbd3_exit);
+MODULE_LICENSE("GPL");
diff --git a/src/kernel/main.c.bak b/src/kernel/main.c.bak
new file mode 100644
index 0000000..600ed3c
--- /dev/null
+++ b/src/kernel/main.c.bak
@@ -0,0 +1,322 @@
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+
+// Own
+#include "config.h"
+#include "include/types.h"
+
+// Network
+#include <net/sock.h>
+//#include <linux/net.h>
+//#include <net/ip.h>
+
+static int major;
+static struct gendisk *disk;
+static struct request_queue *dnbd3_queue;
+
+DEFINE_SPINLOCK( dnbd3_lock);
+
+struct socket *sock;
+struct dnbd3_request r;
+struct dnbd3_reply rp;
+
+uint64_t filesize;
+
+char* host;
+char* port;
+
+// TODO: schauen obs nicht eine fertige gibt
+static unsigned int inet_addr(char *str)
+{
+	int a, b, c, d;
+	char arr[4];
+	sscanf(str, "%d.%d.%d.%d", &a, &b, &c, &d);
+	arr[0] = a;
+	arr[1] = b;
+	arr[2] = c;
+	arr[3] = d;
+	return *(unsigned int*) arr;
+}
+
+static void connect()
+{
+	if (!host || !port)
+	{
+		printk("ERROR: Host or port not set.");
+		return;
+	}
+
+	// Init kernel-socket
+//	static unsigned char address[4] =
+//	{ 132, 230, 4, 29 };
+
+	struct sockaddr_in sin;
+
+	if (sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock) < 0)
+	{
+		printk("DNBD3: Couldn't create socket.\n");
+	}
+	sin.sin_family = AF_INET;
+	//memcpy(&sin.sin_addr.s_addr, address, 4);
+	sin.sin_addr.s_addr = inet_addr(host);
+	sin.sin_port = htons(simple_strtol(port, NULL, 10));
+	if (kernel_connect(sock, (struct sockaddr *) &sin, sizeof(sin), 0) < 0)
+	{
+		printk("DNBD3: Couldn't connect.\n");
+		return;
+	}
+
+	// Ask for filesize
+	struct msghdr msg;
+	struct kvec iov;
+	int size, result;
+	void *buf = &r;
+	r.cmd = CMD_GET_SIZE;
+	size = sizeof(r);
+	do
+	{
+		sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+		iov.iov_base = (char *) buf;
+		iov.iov_len = size;
+		msg.msg_name = NULL;
+		msg.msg_namelen = 0;
+		msg.msg_control = NULL;
+		msg.msg_controllen = 0;
+		msg.msg_flags = MSG_NOSIGNAL; // No SIGPIPE
+
+		result = kernel_sendmsg(sock, &msg, &iov, 1, size);
+
+		if (result <= 0)
+		{
+			if (result == 0)
+				result = -EPIPE; /* short read */
+			break;
+		}
+		size -= result;
+		buf += result;
+	} while (size > 0);
+	buf = &rp;
+	size = sizeof(rp);
+	do
+	{
+		sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+		iov.iov_base = (char *) buf;
+		iov.iov_len = size;
+		msg.msg_name = NULL;
+		msg.msg_namelen = 0;
+		msg.msg_control = NULL;
+		msg.msg_controllen = 0;
+		msg.msg_flags = MSG_NOSIGNAL; // No SIGPIPE
+
+		result = kernel_recvmsg(sock, &msg, &iov, 1, size, msg.msg_flags);
+
+		if (result <= 0)
+		{
+			if (result == 0)
+				result = -EPIPE; /* short read */
+			break;
+		}
+		size -= result;
+		buf += result;
+	} while (size > 0);
+
+	filesize = rp.num;
+	printk("Filesize: %llu\n", filesize);
+
+	//filesize = 721127424;
+	set_capacity(disk, filesize >> 9); /* 512 Byte blocks */
+
+}
+
+static void dnbd3_request(struct request_queue *q)
+{
+	if (!sock)
+		return;
+
+	struct request *req;
+	unsigned long start, to_copy;
+	int size, result;
+	void *buf;
+	struct msghdr msg;
+	struct kvec iov;
+
+	while ((req = blk_fetch_request(q)) != NULL)
+	{
+		if (req->cmd_type != REQ_TYPE_FS)
+		{
+			if (!__blk_end_request_cur(req, 0))
+				req = blk_fetch_request(q);
+			continue;
+		}
+		start = blk_rq_pos(req) << 9; // *512
+
+		//to_copy = blk_rq_cur_bytes(req);	// Returns bytes left to complete in the current segment
+		to_copy = blk_rq_bytes(req); // blk_rq_bytes() Returns bytes left to complete in the entire request
+
+		spin_unlock_irq(q->queue_lock);
+		if ((start + to_copy) <= filesize)
+		{
+			if (rq_data_dir(req) == READ)
+			{
+				// Send msg
+				//printk("Send...\n");
+				buf = &r;
+				r.cmd = CMD_GET_BLOCK;
+				r.num = start;
+				r.to_copy = to_copy;
+				size = sizeof(r);
+				do
+				{
+					sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+					iov.iov_base = (char *) buf;
+					iov.iov_len = size;
+					msg.msg_name = NULL;
+					msg.msg_namelen = 0;
+					msg.msg_control = NULL;
+					msg.msg_controllen = 0;
+					msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
+
+					result = kernel_sendmsg(sock, &msg, &iov, 1, size);
+
+					if (result <= 0)
+					{
+						if (result == 0)
+							result = -EPIPE; /* short read */
+						break;
+					}
+					size -= result;
+					buf += result;
+				} while (size > 0);
+
+				// Test - receive msg
+				struct req_iterator iter;
+				struct bio_vec *bvec;
+				rq_for_each_segment(bvec, req, iter)
+					{
+						void *kaddr = kmap(bvec->bv_page);
+						buf = kaddr + bvec->bv_offset;
+						size = bvec->bv_len;
+						do
+						{
+							sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed.
+							iov.iov_base = buf;
+							iov.iov_len = size;
+							msg.msg_name = NULL;
+							msg.msg_namelen = 0;
+							msg.msg_control = NULL;
+							msg.msg_controllen = 0;
+							msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
+
+							result = kernel_recvmsg(sock, &msg, &iov, 1, size,
+									msg.msg_flags);
+
+							if (result <= 0)
+							{
+								if (result == 0)
+									result = -EPIPE; /* short read */
+								break;
+							}
+							size -= result;
+							buf += result;
+
+							if (size > 0)
+								printk("SIZE > 0\n");
+
+						} while (size > 0);
+
+						kunmap(bvec->bv_page);
+					}
+
+			}
+			else
+			{
+				printk("ERROR: Write not supported.");
+			}
+		}
+		else
+		{
+			printk("ERROR: %ld not in range...\n", start + to_copy);
+		}
+		spin_lock_irq(q->queue_lock);
+		__blk_end_request_all(req, 0);
+	}
+}
+
+static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
+		unsigned int cmd, unsigned long arg)
+{
+	switch (cmd)
+	{
+
+	case IOCTL_SET_HOST:
+		host = (char *) arg;
+		break;
+
+	case IOCTL_SET_PORT:
+		port = (char *) arg;
+		break;
+
+	case IOCTL_CONNECT:
+		connect();
+		break;
+
+	default:
+		return -1;
+
+	}
+	return 0;
+}
+
+static struct block_device_operations dnbd3_ops =
+{ .owner = THIS_MODULE, .ioctl = dnbd3_ioctl, };
+
+static int __init dnbd3_init(void)
+{
+
+	// Init blkdev
+	if ((major = register_blkdev(0, "dnbd")) == 0)
+	{
+		printk("dnbd3: can't get majornumber\n");
+		return -EIO;
+	}
+	printk("major: %d\n", major);
+	if (!(disk = alloc_disk(1)))
+	{
+		printk("alloc_disk failed ...\n");
+		goto out;
+	}
+	disk->major = major;
+	disk->first_minor = 0;
+	sprintf(disk->disk_name, "dnbd0");
+	//set_capacity(disk, filesize >> 9); /* 512 Byte blocks */
+	set_capacity(disk, 0);
+	disk->fops = &dnbd3_ops;
+
+	if ((dnbd3_queue = blk_init_queue(&dnbd3_request, &dnbd3_lock)) == NULL)
+		goto out;
+
+	blk_queue_logical_block_size(dnbd3_queue, DNBD3_BLOCK_SIZE); // set logical block size for the queue
+//	blk_queue_max_hw_sectors(dnbd3_queue, DNBD3_BLOCK_SIZE / KERNEL_SECTOR_SIZE); // set max sectors for a request for this queue, min 8
+//	blk_queue_max_segments(dnbd3_queue, 1); // set max hw segments for a request for this queue
+//	blk_queue_max_segment_size(dnbd3_queue, DNBD3_BLOCK_SIZE); // set max segment size for blk_rq_map_sg, min 4096
+	disk->queue = dnbd3_queue;
+
+	add_disk(disk);
+	return 0;
+	out: return -EIO;
+}
+
+static void __exit dnbd3_exit(void)
+{
+	if (sock)
+		sock_release(sock);
+	unregister_blkdev(major, "dnbd");
+	del_gendisk(disk);
+	put_disk(disk);
+	blk_cleanup_queue(dnbd3_queue);
+}
+
+module_init( dnbd3_init);
+module_exit( dnbd3_exit);
+MODULE_LICENSE("GPL");
diff --git a/src/server/file.c b/src/server/file.c
new file mode 100644
index 0000000..c53ca15
--- /dev/null
+++ b/src/server/file.c
@@ -0,0 +1,58 @@
+#include <fcntl.h>
+#include <errno.h>
+#include "file.h"
+
+int file_open(char *filename)
+{
+	int fd = open(filename, O_RDONLY);
+	if (fd == -1)
+		return -1;
+
+	struct stat st;
+	if (fstat(fd, &st) == -1)
+		return -1;
+
+	return fd;
+}
+
+int file_getsize(int fd, off_t *size)
+{
+	*size = lseek64(fd, 0, SEEK_END);
+
+	if (*size == -1)
+		return -1;
+
+	return 0;
+}
+
+int file_read(int fd, void *buf, size_t size, off_t pos)
+{
+	off_t newpos = lseek(fd, pos, SEEK_SET);
+
+	if (newpos == -1)
+		return -1;
+
+	size_t nleft = size;
+	ssize_t nread;
+	char *ptr = buf;
+
+	while (nleft > 0)
+	{
+		if ((nread = read(fd, ptr, nleft)) < 0)
+		{
+			if (errno == EINTR)
+				continue;
+
+			return -1;
+		}
+		if (nread == 0)
+		{
+			break;
+		}
+
+		nleft -= nread;
+		ptr += nread;
+	}
+
+	return 0;
+}
diff --git a/src/server/file.h b/src/server/file.h
new file mode 100644
index 0000000..e61849a
--- /dev/null
+++ b/src/server/file.h
@@ -0,0 +1,7 @@
+#include <unistd.h>
+
+int file_open(char *filename);
+
+int file_getsize(int fd, off_t *size);
+
+int file_read(int fd, void *buf, size_t size, off_t pos);
diff --git a/src/server/server.c b/src/server/server.c
new file mode 100644
index 0000000..e38a0e3
--- /dev/null
+++ b/src/server/server.c
@@ -0,0 +1,173 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <signal.h>
+#include <getopt.h>
+#include <netinet/in.h>
+#include <sys/sendfile.h>
+
+#include <pthread.h>
+
+#include "../include/types.h"
+#include "../version.h"
+#include "file.h"
+
+int file;
+
+void print_help(char* argv_0)
+{
+
+	printf("Usage: %s [OPTIONS]...\n", argv_0);
+	printf("Start the DNBD3 server.\n");
+	printf("-f or --file \t\t File to export.\n");
+	printf("-h or --help \t\t Show this help text and quit.\n");
+	printf("-v or --version \t Show version and quit.\n");
+	exit(0);
+}
+
+void print_version()
+{
+	printf("Version: %s\n", VERSION_STRING);
+	exit(0);
+}
+
+void handle_sigpipe(int signum)
+{
+	printf("Program received signal SIGPIPE, Broken pipe (errno: %i)\n", errno);
+	return;
+}
+
+void *echo(void *client_socket)
+{
+	int sock = (int) client_socket;
+	struct dnbd3_request request;
+	struct dnbd3_reply reply;
+	uint16_t cmd;
+	off_t filesize;
+
+	while (recv(sock, &request, sizeof(struct dnbd3_request), MSG_WAITALL) > 0)
+	{
+		cmd = request.cmd;
+//		char buf[request.size];
+		switch (cmd)
+		{
+		case CMD_GET_SIZE:
+			reply.cmd = request.cmd;
+			file_getsize(file, &filesize);
+			reply.filesize = filesize;
+			send(sock, (char *) &reply, sizeof(struct dnbd3_reply), 0);
+			break;
+
+		case CMD_GET_BLOCK:
+//			printf("CMD: %i, Byte: %llu, Size: %llu\n",request.cmd, request.offset, request.size);
+//			file_read(file, buf, request.size, request.offset);
+//			send(sock, (char *) buf, request.size, 0);
+			sendfile(sock, file, (off_t *) &request.offset, request.size);
+			break;
+
+		default:
+			;
+		}
+
+	}
+	close(sock);
+	printf("Client exit.\n");
+	pthread_exit((void *)0);
+}
+
+int main(int argc, char* argv[])
+{
+	int opt = 0;
+	int longIndex = 0;
+	static const char *optString = "f:hv?";
+	static const struct option longOpts[] =
+	{
+	{ "file", required_argument, NULL, 'f' },
+	{ "help", no_argument, NULL, 'h' },
+	{ "version", no_argument, NULL, 'v' } };
+
+	opt = getopt_long(argc, argv, optString, longOpts, &longIndex);
+	if (opt == -1)
+		print_help(argv[0]);
+
+	while (opt != -1)
+	{
+		switch (opt)
+		{
+		case 'f':
+			file = file_open(optarg);
+			break;
+		case 'h':
+			print_help(argv[0]);
+			break;
+		case 'v':
+			print_version();
+			break;
+		case '?':
+			exit(1);
+		}
+		opt = getopt_long(argc, argv, optString, longOpts, &longIndex);
+	}
+
+	signal(SIGPIPE, handle_sigpipe);
+
+	struct sockaddr_in server;
+	struct sockaddr_in client[50];
+	int sock, fd;
+	unsigned int len;
+	pthread_t thread[50];
+	int i=1;
+
+	// Create socket
+	sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sock < 0)
+	{
+		printf("ERROR: Socket failure\n");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&server, 0, sizeof(server));
+	server.sin_family = AF_INET; // IPv4
+	server.sin_addr.s_addr = htonl(INADDR_ANY); // Take all IPs
+	server.sin_port = htons(PORT); // set port number
+
+	// Bind to socket
+	if (bind(sock, (struct sockaddr*) &server, sizeof(server)) < 0)
+	{
+		printf("ERROR: Bind failure\n");
+		exit(EXIT_FAILURE);
+	}
+
+	// Listen on socket
+	if (listen(sock, 50) == -1)
+	{
+		printf("ERROR: Listen failure\n");
+		exit(EXIT_FAILURE);
+	}
+
+	printf("INFO: Server is ready...\n");
+
+	// TODO: dyn threads
+	while (1)
+	{
+		len = sizeof(client);
+		fd = accept(sock, (struct sockaddr*) &client[i], &len);
+		if (fd < 0)
+		{
+			printf("ERROR: Accept failure\n");
+			exit(EXIT_FAILURE);
+		}
+
+		printf("INFO: Client: %s connected\n", inet_ntoa(client[i].sin_addr));
+		pthread_create(&(thread[i]), NULL, echo, (void *) fd);
+		pthread_detach(thread[i++]);
+	}
+	return EXIT_SUCCESS;
+}
diff --git a/src/version.h b/src/version.h
new file mode 100644
index 0000000..86e034a
--- /dev/null
+++ b/src/version.h
@@ -0,0 +1,7 @@
+#ifndef VERSION_H_
+#define VERSION_H_
+
+#define VERSION_STRING "0.1.0"
+#define VERSION_NUMBER 010
+
+#endif /* VERSION_H_ */