added code to connect to server

6 files changed, 248 insertions, 4 deletions

diff --git a/src/kernel/block.c b/src/kernel/block.c
index bd2f8d7..4eb52c5 100644
--- a/src/kernel/block.c
+++ b/src/kernel/block.c
@@ -5,11 +5,21 @@
  *      Author: fred
  */
 
+#include <net/sock.h>
 
 #include "dnbd3.h"
 #include "block.h"
+#include "clientconfig.h"
 
+#define dnbd3_sock_create(af,type,proto,sock) sock_create_kern(&init_net, (af) == HOST_IP4 ? AF_INET : AF_INET6, type, proto, sock)
 
+#define init_msghdr(h) do { \
+        h.msg_name = NULL; \
+        h.msg_namelen = 0; \
+        h.msg_control = NULL; \
+        h.msg_controllen = 0; \
+        h.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; \
+	} while (0)
 
 static int dnbd3_open(struct block_device *bdev, fmode_t mode)
 {
@@ -34,16 +44,236 @@ void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev)
 }
 
 
+
 int dnbd3_net_connect(dnbd3_device_t *dev)
 {
+	struct request *req1 = NULL;
+	struct timeval timeout;
+
 	printk(KERN_DEBUG "dnbd3: net connect device %i\n", dev->minor);
+
+	if (dev->disconnecting) {
+		printk(KERN_DEBUG "dnbd3: device still disconnecting\n");
+		while (dev->disconnecting)
+			schedule();
+	}
+	if (dev->request) {
+		printk(KERN_DEBUG "dnbd3: device still in request\n");
+		while (dev->disconnecting)
+			schedule();
+	}
+
+	timeout.tv_sec = SOCKET_TIMEOUT_CLIENT_DATA;
+	timeout.tv_usec = 0;
+
+	// do some checks before connecting
+
+	req1 = kmalloc(sizeof(*req1), GFP_ATOMIC );
+	if (!req1) {
+		printk(KERN_ERR "dnbd3: kmalloc failed\n");
+		goto error;
+	}
+	if (dev->cur_server.host.port == 0 || dev->cur_server.host.type == 0 || dev->imgname == NULL ) {
+		printk(KERN_ERR "dnbd3: host, port or image name not set\n");
+		goto error;
+	}
+	if (dev->sock) {
+		printk(KERN_WARNING "dnbd3: already connected\n");
+		goto error;
+	}
+
+	if (dev->cur_server.host.type != HOST_IP4 && dev->cur_server.host.type != HOST_IP6) {
+		printk(KERN_ERR "dnbd3: unknown address type %d\n", (int)dev->cur_server.host.type);
+		goto error;
+	}
+
+	if (dev->better_sock == NULL ) {
+		//  no established connection yet from discovery thread, start new one
+		dnbd3_request_t dnbd3_request;
+		dnbd3_reply_t dnbd3_reply;
+		struct msghdr msg;
+		struct kvec iov[2];
+		uint16_t rid;
+		char *name;
+		int mlen;
+		init_msghdr(msg);
+
+		if (dnbd3_sock_create(dev->cur_server.host.type, SOCK_STREAM, IPPROTO_TCP, &dev->sock) < 0) {
+			printk(KERN_ERR "dnbd3: could not create socket\n");
+			goto error;
+		}
+
+		kernel_setsockopt(dev->sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout));
+		kernel_setsockopt(dev->sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));
+		dev->sock->sk->sk_allocation = GFP_NOIO;
+		if (dev->cur_server.host.type == HOST_IP4) {
+			struct sockaddr_in sin;
+			memset(&sin, 0, sizeof(sin));
+			sin.sin_family = AF_INET;
+			memcpy(&(sin.sin_addr), dev->cur_server.host.addr, 4);
+			sin.sin_port = dev->cur_server.host.port;
+			if (kernel_connect(dev->sock, (struct sockaddr *)&sin, sizeof(sin), 0) != 0) {
+				printk(KERN_ERR "dnbd3: connection to host failed (ipv4)\n");
+				goto error;
+			}
+		} else {
+			struct sockaddr_in6 sin;
+			memset(&sin, 0, sizeof(sin));
+			sin.sin6_family = AF_INET6;
+			memcpy(&(sin.sin6_addr), dev->cur_server.host.addr, 16);
+			sin.sin6_port = dev->cur_server.host.port;
+			if (kernel_connect(dev->sock, (struct sockaddr *)&sin, sizeof(sin), 0) != 0){
+				printk(KERN_ERR "dnbd3: connection to host failed (ipv6)\n");
+				goto error;
+			}
+		}
+		// Request filesize
+		dnbd3_request.magic = dnbd3_packet_magic;
+		dnbd3_request.cmd = CMD_SELECT_IMAGE;
+		iov[0].iov_base = &dnbd3_request;
+		iov[0].iov_len = sizeof(dnbd3_request);
+		serializer_reset_write(&dev->payload_buffer);
+		serializer_put_uint16(&dev->payload_buffer, PROTOCOL_VERSION);
+		serializer_put_string(&dev->payload_buffer, dev->imgname);
+		serializer_put_uint16(&dev->payload_buffer, dev->rid);
+		serializer_put_uint8(&dev->payload_buffer, 0); // is_server = false
+		iov[1].iov_base = &dev->payload_buffer;
+		dnbd3_request.size = iov[1].iov_len = serializer_get_written_length(&dev->payload_buffer);
+		fixup_request(dnbd3_request);
+		mlen = sizeof(dnbd3_request) + iov[1].iov_len;
+		if (kernel_sendmsg(dev->sock, &msg, iov, 2, mlen) != mlen) {
+			printk(KERN_ERR "dnbd3: could not send CMD_SIZE_REQUEST\n");
+			goto error;
+		}
+		// receive reply header
+		iov[0].iov_base = &dnbd3_reply;
+		iov[0].iov_len = sizeof(dnbd3_reply);
+		if (kernel_recvmsg(dev->sock, &msg, iov, 1, sizeof(dnbd3_reply), msg.msg_flags) != sizeof(dnbd3_reply)) {
+			printk(KERN_ERR "dnbd3: received corrupted reply header after CMD_SIZE_REQUEST\n");
+			goto error;
+		}
+
+		// check reply header
+		fixup_reply(dnbd3_reply);
+		if (dnbd3_reply.cmd != CMD_SELECT_IMAGE ||
+				dnbd3_reply.size < 3 ||
+				dnbd3_reply.size > MAX_PAYLOAD ||
+				dnbd3_reply.magic != dnbd3_packet_magic) {
+			printk(KERN_ERR "dnbd3: received invalid reply to CMD_SIZE_REQUEST image does not exist on server\n");
+			goto error;
+		}
+
+		// receive reply payload
+		iov[0].iov_base = &dev->payload_buffer;
+		iov[0].iov_len = dnbd3_reply.size;
+		if (kernel_recvmsg(dev->sock, &msg, iov, 1, dnbd3_reply.size, msg.msg_flags) != dnbd3_reply.size) {
+			printk(KERN_ERR "dnbd3: could not read CMD_SELECT_IMAGE payload on handshake\n");
+			goto error;
+		}
+
+		// handle/check reply payload
+		serializer_reset_read(&dev->payload_buffer, dnbd3_reply.size);
+		dev->cur_server.protocol_version = serializer_get_uint16(&dev->payload_buffer);
+		if (dev->cur_server.protocol_version < MIN_SUPPORTED_SERVER) {
+			printk(KERN_ERR "dnbd3: server version is lower than min supported version\n");
+			goto error;
+		}
+
+		name = serializer_get_string(&dev->payload_buffer);
+		if (dev->rid != 0 && strcmp(name, dev->imgname) != 0) {
+			printk(KERN_ERR "dnbd3: server offers image '%s', requested '%s'\n", name, dev->imgname);
+			goto error;
+		}
+
+		if (strlen(dev->imgname) < strlen(name)) {
+			dev->imgname = krealloc(dev->imgname, strlen(name) + 1, GFP_ATOMIC );
+			if (dev->imgname == NULL ) {
+				printk(KERN_ERR "dnbd3: reallocating buffer for new image name failed\n");
+				goto error;
+			}
+		}
+		strcpy(dev->imgname, name);
+		rid = serializer_get_uint16(&dev->payload_buffer);
+		if (dev->rid != 0 && dev->rid != rid) {
+			printk(KERN_ERR "dnbd3: server provides rid %d, requested was %d\n", (int)rid, (int)dev->rid);
+			goto error;
+		}
+
+		dev->rid = rid;
+		dev->reported_size = serializer_get_uint64(&dev->payload_buffer);
+		if (dev->reported_size < 4096) {
+			printk(KERN_ERR "dnbd3: reported size by server is < 4096\n");
+			goto error;
+		}
+
+		// store image information
+		set_capacity(dev->disk, dev->reported_size >> 9); /* 512 Byte blocks */
+		printk(KERN_DEBUG "dnbd3: connected to image %s, filesize %llu\n", dev->imgname, dev->reported_size);
+		dev->update_available = 0;
+	} else { // Switching server, connection is already established and size request was executed
+
+		printk(KERN_DEBUG "dnbd3: changing server\n");
+		dev->sock = dev->better_sock;
+		dev->better_sock = NULL;
+		kernel_setsockopt(dev->sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout));
+		kernel_setsockopt(dev->sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));
+	}
+
+	dev->panic = 0;
+	dev->panic_count = 0;
+
+	// Enqueue request to request_queue_send for a fresh list of alt servers
+	//TODO refresh alt server list
+
+	// add heartbeat timer
+	//TODO needed anymore=
+//	dev->heartbeat_count = 0;
+//	timer_setup(&dev->hb_timer, dnbd3_net_heartbeat, 0);
+//	dev->hb_timer.expires = jiffies + HZ;
+//	add_timer(&dev->hb_timer);
 	return 0;
+error:
+	if (dev->sock) {
+		sock_release(dev->sock);
+		dev->sock = NULL;
+	}
+	dev->cur_server.host.type = 0;
+	dev->cur_server.host.port = 0;
+	if (req1) {
+		kfree(req1);
+	}
+	return -1;
 }
 
 
 int dnbd3_net_disconnect(dnbd3_device_t *dev)
 {
 	printk(KERN_DEBUG "dnbd3: net disconnect device %i\n", dev->minor);
+	if (dev->disconnecting)  {
+		return 0;
+	}
+
+	dev->disconnecting = 1;
+
+	// clear heartbeat timer
+//	del_timer(&dev->hb_timer);
+
+	dev->discover = 0;
+
+	if (dev->sock) {
+		kernel_sock_shutdown(dev->sock, SHUT_RDWR);
+	}
+
+	// clear socket
+	if (dev->sock) {
+		sock_release(dev->sock);
+		dev->sock = NULL;
+	}
+	dev->cur_server.host.type = 0;
+	dev->cur_server.host.port = 0;
+
+	dev->disconnecting = 0;
+
 	return 0;
 }
 
diff --git a/src/kernel/block.h b/src/kernel/block.h
index 5493a00..af99108 100644
--- a/src/kernel/block.h
+++ b/src/kernel/block.h
@@ -8,6 +8,11 @@
 #ifndef SRC_KERNEL_BLOCK_H_
 #define SRC_KERNEL_BLOCK_H_
 
+
+int dnbd3_net_connect(dnbd3_device_t *dev);
+
+int dnbd3_net_disconnect(dnbd3_device_t *dev);
+
 extern struct block_device_operations dnbd3_fops;
 
 
diff --git a/src/kernel/core.c b/src/kernel/core.c
index 7725a1d..3b30a11 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -427,6 +427,9 @@ static void dnbd3_dev_remove(struct dnbd3_device_t *dnbd3)
 		del_gendisk(disk);
 		blk_cleanup_queue(q);
 		blk_mq_free_tag_set(&dnbd3->tag_set);
+		if (dnbd3->sock) {
+			dnbd3_net_disconnect(dnbd3);
+		}
 		disk->private_data = NULL;
 		put_disk(disk);
 	}
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index b8b0f59..3fb625a 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -28,6 +28,7 @@
 
 #define KERNEL_MODULE
 #include "types.h"
+#include "serialize.h"
 
 typedef struct
 {
@@ -58,11 +59,11 @@ typedef struct dnbd3_device_t {
 	struct socket *sock;
 	dnbd3_server_t cur_server, initial_server;
 	uint64_t cur_rtt;
-//	serialized_buffer_t payload_buffer;
+	serialized_buffer_t payload_buffer;
 	dnbd3_server_t alt_servers[NUMBER_SERVERS]; // array of alt servers
 	int new_servers_num;	// number of new alt servers that are waiting to be copied to above array
 	dnbd3_server_entry_t new_servers[NUMBER_SERVERS]; // pending new alt servers
-	uint8_t discover, panic, disconnecting, update_available, panic_count;
+	uint8_t discover, panic, disconnecting, update_available, panic_count, request;
 	uint8_t use_server_provided_alts;
 	uint16_t rid;
 	uint32_t heartbeat_count;
diff --git a/src/kernel/mq.c b/src/kernel/mq.c
index d402ecf..ee60574 100644
--- a/src/kernel/mq.c
+++ b/src/kernel/mq.c
@@ -16,7 +16,7 @@ static int dnbd3_handle_cmd(struct dnbd3_cmd *cmd, int index)
 	struct request *req = blk_mq_rq_from_pdu(cmd);
 	struct dnbd3_device_t *dev = cmd->dnbd3;
 	struct dnbd3_sock *nsock;
-	int ret;
+	int ret = -1;
 
 	printk(KERN_DEBUG "dnbd3: handle command %i device %i\n", cmd->cmd_cookie, dev->minor);
 
@@ -46,7 +46,7 @@ static blk_status_t dnbd3_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_
 		ret = BLK_STS_OK;
 	mutex_unlock(&cmd->lock);
 
-	return -10;
+	return ret;
 }
 
 static void dnbd3_complete_rq(struct request *req)
diff --git a/src/kernel/serialize_kmod.c b/src/kernel/serialize_kmod.c
new file mode 100644
index 0000000..50746df
--- /dev/null
+++ b/src/kernel/serialize_kmod.c
@@ -0,0 +1,5 @@
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#define KERNEL_MODULE
+#include "serialize.c"