First working version :)

1 files changed, 206 insertions, 0 deletions

diff --git a/src/kernel/net.c b/src/kernel/net.c
new file mode 100644
index 0000000..0e7a871
--- /dev/null
+++ b/src/kernel/net.c
@@ -0,0 +1,206 @@
+/*
+ * This file is part of the Distributed Network Block Device 3
+ *
+ * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
+ *
+ * This file may be licensed under the terms of of the
+ * GNU General Public License Version 2 (the ``GPL'').
+ *
+ * Software distributed under the License is distributed
+ * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
+ * express or implied. See the GPL for the specific language
+ * governing rights and limitations.
+ *
+ * You should have received a copy of the GPL along with this
+ * program. If not, go to http://www.gnu.org/licenses/gpl.html
+ * or write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "net.h"
+#include "utils.h"
+
+void dnbd3_net_connect(void)
+{
+	struct sockaddr_in sin;
+	struct msghdr msg;
+	struct kvec iov;
+	struct dnbd3_request dnbd3_request;
+	struct dnbd3_reply dnbd3_reply;
+	struct task_struct *thread_send;
+	struct task_struct *thread_receive;
+
+	if (!_host || !_port)
+	{
+		printk("ERROR: Host or port not set.");
+		return;
+	}
+
+	// initialize socket
+	if (sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &_sock) < 0)
+	{
+		printk("ERROR: dnbd3 couldn't create socket.\n");
+		return;
+	}
+	_sock->sk->sk_allocation = GFP_NOIO;
+	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 and send request
+	dnbd3_request.cmd = CMD_GET_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
+
+	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
+	// FIXME: files > 4GB
+	printk("INFO: dnbd3 filesize: %llu\n", dnbd3_reply.filesize);
+	set_capacity(disk, dnbd3_reply.filesize >> 9); /* 512 Byte blocks */
+
+	// start sending thread
+	thread_send = kthread_create(dnbd3_net_send, NULL, "none");
+	wake_up_process(thread_send);
+
+	// start receiving thread
+	thread_receive = kthread_create(dnbd3_net_receive, NULL, "none");
+	wake_up_process(thread_receive);
+}
+
+int dnbd3_net_send(void *data)
+{
+	struct dnbd3_request dnbd3_request;
+	struct request *blk_request;
+	struct msghdr msg;
+	struct kvec iov;
+
+	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
+
+	set_user_nice(current, -20);
+
+	while (!kthread_should_stop() || !list_empty(&_request_queue_send))
+	{
+		wait_event_interruptible(_process_queue_send,
+				kthread_should_stop() || !list_empty(&_request_queue_send));
+
+		if (list_empty(&_request_queue_send))
+			continue;
+
+		// extract block request
+		spin_lock_irq(&dnbd3_lock);
+		blk_request = list_entry(_request_queue_send.next, struct request, queuelist);
+		list_del_init(&blk_request->queuelist);
+		spin_unlock_irq(&dnbd3_lock);
+
+		// prepare net request
+		dnbd3_request.cmd = CMD_GET_BLOCK;
+		dnbd3_request.offset = blk_rq_pos(blk_request) << 9; // *512
+		dnbd3_request.size = blk_rq_bytes(blk_request); // blk_rq_bytes() Returns bytes left to complete in the entire request
+		memcpy(dnbd3_request.handle, &blk_request, sizeof(blk_request));
+		iov.iov_base = &dnbd3_request;
+		iov.iov_len = sizeof(dnbd3_request);
+
+		// send net request
+		if (kernel_sendmsg(_sock, &msg, &iov, 1, sizeof(dnbd3_request)) <= 0)
+			printk("ERROR: kernel_sendmsg\n");
+
+		spin_lock_irq(&dnbd3_lock);
+		list_add_tail(&blk_request->queuelist, &_request_queue_receive);
+		spin_unlock_irq(&dnbd3_lock);
+		wake_up(&_process_queue_receive);
+	}
+	return 0;
+}
+
+int dnbd3_net_receive(void *data)
+{
+	struct dnbd3_reply dnbd3_reply;
+	struct request *blk_request;
+	struct msghdr msg;
+	struct kvec iov;
+	struct req_iterator iter;
+	struct bio_vec *bvec;
+	unsigned long flags;
+	sigset_t blocked, oldset;
+	struct request *tmp_request, *received_request;
+	void *kaddr;
+	int 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
+
+	set_user_nice(current, -20);
+
+	while (!kthread_should_stop() || !list_empty(&_request_queue_receive))
+	{
+		wait_event_interruptible(_process_queue_receive,
+				kthread_should_stop() || !list_empty(&_request_queue_receive));
+
+		// receive net replay
+		iov.iov_base = &dnbd3_reply;
+		iov.iov_len = sizeof(dnbd3_reply);
+		kernel_recvmsg(_sock, &msg, &iov, 1, sizeof(dnbd3_reply),
+				msg.msg_flags);
+
+		// search for replied request in queue
+		received_request = *(struct request **) dnbd3_reply.handle;
+		spin_lock_irq(&dnbd3_lock);
+		list_for_each_entry_safe(blk_request, tmp_request,
+				&_request_queue_receive, queuelist)
+		{
+			if (blk_request != received_request)
+				continue;
+
+			list_del_init(&blk_request->queuelist);
+			break;
+		}
+		spin_unlock_irq(&dnbd3_lock);
+
+		// receive data and answer to block layer
+		rq_for_each_segment(bvec, blk_request, iter)
+			{
+				siginitsetinv(&blocked, sigmask(SIGKILL));
+				sigprocmask(SIG_SETMASK, &blocked, &oldset);
+
+				kaddr = kmap(bvec->bv_page) + bvec->bv_offset;
+				size = bvec->bv_len;
+				iov.iov_base = kaddr;
+				iov.iov_len = size;
+				kernel_recvmsg(_sock, &msg, &iov, 1, size, msg.msg_flags);
+				kunmap(bvec->bv_page);
+
+				sigprocmask(SIG_SETMASK, &oldset, NULL);
+			}
+
+		spin_lock_irqsave(&dnbd3_lock, flags);
+		__blk_end_request_all(blk_request, 0);
+		spin_unlock_irqrestore(&dnbd3_lock, flags);
+	}
+
+	return 0;
+}
+