Staging: USB/IP: add common functions needed

This adds the common functions needed by both the host and client side
of the USB/IP code.

Brian Merrell cleaned up a lot of this code and submitted it for
inclusion.  Greg also did a lot of cleanup.

Signed-off-by: Brian G. Merrell <bgmerrell@novell.com>
Cc: Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

8 files changed, 1573 insertions, 0 deletions

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index f16bc9cdaf33..4dbf795df744 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -33,4 +33,6 @@ source "drivers/staging/me4000/Kconfig"
 
 source "drivers/staging/go7007/Kconfig"
 
+source "drivers/staging/usbip/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index aa61662e6321..be42c0d4db0e 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_SLICOSS)		+= slicoss/
 obj-$(CONFIG_SXG)		+= sxg/
 obj-$(CONFIG_ME4000)		+= me4000/
 obj-$(CONFIG_VIDEO_GO7007)	+= go7007/
+obj-$(CONFIG_USB_IP_COMMON)	+= usbip/
diff --git a/drivers/staging/usbip/Kconfig b/drivers/staging/usbip/Kconfig
new file mode 100644
index 000000000000..37efb5e1bb82
--- /dev/null
+++ b/drivers/staging/usbip/Kconfig
@@ -0,0 +1,14 @@
+config USB_IP_COMMON
+	tristate "USB IP support (EXPERIMENTAL)"
+	depends on USB && EXPERIMENTAL
+	default N
+	---help---
+	  This enables pushing USB packets over IP to allow remote
+	  machines access to USB devices directly.  For more details,
+	  and links to the userspace utility programs to let this work
+	  properly, see http://usbip.naist.jp/
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbip_common_mod.
+
+	  If unsure, say N.
diff --git a/drivers/staging/usbip/Makefile b/drivers/staging/usbip/Makefile
new file mode 100644
index 000000000000..ce925caa6083
--- /dev/null
+++ b/drivers/staging/usbip/Makefile
@@ -0,0 +1,6 @@
+obj-$(CONFIG_USB_IP_COMMON) += usbip_common_mod.o
+usbip_common_mod-objs := usbip_common.o usbip_event.o
+
+ifeq ($(CONFIG_USB_DEBUG),y)
+	EXTRA_CFLAGS += -DDEBUG
+endif
diff --git a/drivers/staging/usbip/README b/drivers/staging/usbip/README
new file mode 100644
index 000000000000..c11be5735485
--- /dev/null
+++ b/drivers/staging/usbip/README
@@ -0,0 +1,6 @@
+TODO:
+	- more discussion about the protocol
+	- testing
+	- review of the userspace interface
+
+Please send patches for this code to Greg Kroah-Hartman <greg@kroah.com>
diff --git a/drivers/staging/usbip/usbip_common.c b/drivers/staging/usbip/usbip_common.c
new file mode 100644
index 000000000000..e64918f42ff7
--- /dev/null
+++ b/drivers/staging/usbip/usbip_common.c
@@ -0,0 +1,997 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This 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 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/tcp.h>
+#include <linux/in.h>
+#include "usbip_common.h"
+
+/* version information */
+#define DRIVER_VERSION "1.0"
+#define DRIVER_AUTHOR "Takahiro Hirofuchi <hirofuchi _at_ users.sourceforge.net>"
+#define DRIVER_DESC "usbip common driver"
+
+/*-------------------------------------------------------------------------*/
+/* debug routines */
+
+#ifdef CONFIG_USB_DEBUG
+unsigned long usbip_debug_flag = 0xffffffff;
+#else
+unsigned long usbip_debug_flag;
+#endif
+EXPORT_SYMBOL_GPL(usbip_debug_flag);
+
+
+/* FIXME */
+struct device_attribute dev_attr_usbip_debug;
+EXPORT_SYMBOL_GPL(dev_attr_usbip_debug);
+
+
+static ssize_t show_flag(struct device *dev, struct device_attribute *attr,
+								char *buf)
+{
+	return sprintf(buf, "%lx\n", usbip_debug_flag);
+}
+
+static ssize_t store_flag(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	unsigned long flag;
+
+	sscanf(buf, "%lx", &flag);
+	usbip_debug_flag = flag;
+
+	return count;
+}
+DEVICE_ATTR(usbip_debug, (S_IRUGO | S_IWUSR), show_flag, store_flag);
+
+static void usbip_dump_buffer(char *buff, int bufflen)
+{
+	int i;
+
+	if (bufflen > 128) {
+		for (i = 0; i < 128; i++) {
+			if (i%24 == 0)
+				printk("   ");
+			printk("%02x ", (unsigned char) buff[i]);
+			if (i%4 == 3)
+				printk("| ");
+			if (i%24 == 23)
+				printk("\n");
+		}
+		printk("... (%d byte)\n", bufflen);
+		return;
+	}
+
+	for (i = 0; i < bufflen; i++) {
+		if (i%24 == 0)
+			printk("   ");
+		printk("%02x ", (unsigned char) buff[i]);
+		if (i%4 == 3)
+			printk("| ");
+		if (i%24 == 23)
+			printk("\n");
+	}
+	printk("\n");
+
+}
+
+static void usbip_dump_pipe(unsigned int p)
+{
+	unsigned char type = usb_pipetype(p);
+	unsigned char ep = usb_pipeendpoint(p);
+	unsigned char dev = usb_pipedevice(p);
+	unsigned char dir = usb_pipein(p);
+
+	printk("dev(%d) ", dev);
+	printk("ep(%d) ",  ep);
+	printk("%s ", dir ? "IN" : "OUT");
+
+	switch (type) {
+	case PIPE_ISOCHRONOUS:
+		printk("%s ", "ISO");
+		break;
+	case PIPE_INTERRUPT:
+		printk("%s ", "INT");
+		break;
+	case PIPE_CONTROL:
+		printk("%s ", "CTL");
+		break;
+	case PIPE_BULK:
+		printk("%s ", "BLK");
+		break;
+	default:
+		printk("ERR");
+	}
+
+	printk("\n");
+
+}
+
+static void usbip_dump_usb_device(struct usb_device *udev)
+{
+	struct device *dev = &udev->dev;
+	int i;
+
+	dev_dbg(dev, "       devnum(%d) devpath(%s)",
+		udev->devnum, udev->devpath);
+
+	switch (udev->speed) {
+	case USB_SPEED_HIGH:
+		printk(" SPD_HIGH");
+		break;
+	case USB_SPEED_FULL:
+		printk(" SPD_FULL");
+		break;
+	case USB_SPEED_LOW:
+		printk(" SPD_LOW");
+		break;
+	case USB_SPEED_UNKNOWN:
+		printk(" SPD_UNKNOWN");
+		break;
+	default:
+		printk(" SPD_ERROR");
+	}
+
+	printk(" tt %p, ttport %d", udev->tt, udev->ttport);
+	printk("\n");
+
+	dev_dbg(dev, "                    ");
+	for (i = 0; i < 16; i++)
+		printk(" %2u", i);
+	printk("\n");
+
+	dev_dbg(dev, "       toggle0(IN) :");
+	for (i = 0; i < 16; i++)
+		printk(" %2u", (udev->toggle[0] & (1 << i)) ? 1 : 0);
+	printk("\n");
+
+	dev_dbg(dev, "       toggle1(OUT):");
+	for (i = 0; i < 16; i++)
+		printk(" %2u", (udev->toggle[1] & (1 << i)) ? 1 : 0);
+	printk("\n");
+
+
+	dev_dbg(dev, "       epmaxp_in   :");
+	for (i = 0; i < 16; i++) {
+		if (udev->ep_in[i])
+			printk(" %2u",
+			     le16_to_cpu(udev->ep_in[i]->desc.wMaxPacketSize));
+	}
+	printk("\n");
+
+	dev_dbg(dev, "       epmaxp_out  :");
+	for (i = 0; i < 16; i++) {
+		if (udev->ep_out[i])
+			printk(" %2u",
+			     le16_to_cpu(udev->ep_out[i]->desc.wMaxPacketSize));
+	}
+	printk("\n");
+
+	dev_dbg(dev, "parent %p, bus %p\n", udev->parent, udev->bus);
+
+	dev_dbg(dev, "descriptor %p, config %p, actconfig %p, "
+		"rawdescriptors %p\n", &udev->descriptor, udev->config,
+		udev->actconfig, udev->rawdescriptors);
+
+	dev_dbg(dev, "have_langid %d, string_langid %d\n",
+		udev->have_langid, udev->string_langid);
+
+	dev_dbg(dev, "maxchild %d, children %p\n",
+		udev->maxchild, udev->children);
+}
+
+static void usbip_dump_request_type(__u8 rt)
+{
+	switch (rt & USB_RECIP_MASK) {
+	case USB_RECIP_DEVICE:
+		printk("DEVICE");
+		break;
+	case USB_RECIP_INTERFACE:
+		printk("INTERF");
+		break;
+	case USB_RECIP_ENDPOINT:
+		printk("ENDPOI");
+		break;
+	case USB_RECIP_OTHER:
+		printk("OTHER ");
+		break;
+	default:
+		printk("------");
+	}
+}
+
+static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
+{
+	if (!cmd) {
+		printk("      %s : null pointer\n", __FUNCTION__);
+		return;
+	}
+
+	printk("       ");
+	printk("bRequestType(%02X) ", cmd->bRequestType);
+	printk("bRequest(%02X) " , cmd->bRequest);
+	printk("wValue(%04X) ", cmd->wValue);
+	printk("wIndex(%04X) ", cmd->wIndex);
+	printk("wLength(%04X) ", cmd->wLength);
+
+	printk("\n       ");
+
+	if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
+		printk("STANDARD ");
+		switch (cmd->bRequest) {
+		case USB_REQ_GET_STATUS:
+			printk("GET_STATUS");
+			break;
+		case USB_REQ_CLEAR_FEATURE:
+			printk("CLEAR_FEAT");
+			break;
+		case USB_REQ_SET_FEATURE:
+			printk("SET_FEAT  ");
+			break;
+		case USB_REQ_SET_ADDRESS:
+			printk("SET_ADDRRS");
+			break;
+		case USB_REQ_GET_DESCRIPTOR:
+			printk("GET_DESCRI");
+			break;
+		case USB_REQ_SET_DESCRIPTOR:
+			printk("SET_DESCRI");
+			break;
+		case USB_REQ_GET_CONFIGURATION:
+			printk("GET_CONFIG");
+			break;
+		case USB_REQ_SET_CONFIGURATION:
+			printk("SET_CONFIG");
+			break;
+		case USB_REQ_GET_INTERFACE:
+			printk("GET_INTERF");
+			break;
+		case USB_REQ_SET_INTERFACE:
+			printk("SET_INTERF");
+			break;
+		case USB_REQ_SYNCH_FRAME:
+			printk("SYNC_FRAME");
+			break;
+		default:
+			printk("REQ(%02X) ", cmd->bRequest);
+		}
+
+		printk(" ");
+		usbip_dump_request_type(cmd->bRequestType);
+
+	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
+		printk("CLASS   ");
+
+	else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR)
+		printk("VENDOR  ");
+
+	else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED)
+		printk("RESERVED");
+
+	printk("\n");
+}
+
+void usbip_dump_urb(struct urb *urb)
+{
+	struct device *dev;
+
+	if (!urb) {
+		printk(KERN_DEBUG KBUILD_MODNAME
+		       ":%s: urb: null pointer!!\n", __func__);
+		return;
+	}
+
+	if (!urb->dev) {
+		printk(KERN_DEBUG KBUILD_MODNAME
+		       ":%s: urb->dev: null pointer!!\n", __func__);
+		return;
+	}
+	dev = &urb->dev->dev;
+
+	dev_dbg(dev, "   urb                   :%p\n", urb);
+	dev_dbg(dev, "   dev                   :%p\n", urb->dev);
+
+	usbip_dump_usb_device(urb->dev);
+
+	dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
+
+	usbip_dump_pipe(urb->pipe);
+
+	dev_dbg(dev, "   status                :%d\n", urb->status);
+	dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
+	dev_dbg(dev, "   transfer_buffer       :%p\n", urb->transfer_buffer);
+	dev_dbg(dev, "   transfer_buffer_length:%d\n", urb->transfer_buffer_length);
+	dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
+	dev_dbg(dev, "   setup_packet          :%p\n", urb->setup_packet);
+
+	if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
+			usbip_dump_usb_ctrlrequest(
+			(struct usb_ctrlrequest *)urb->setup_packet);
+
+	dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
+	dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
+	dev_dbg(dev, "   interval              :%d\n", urb->interval);
+	dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
+	dev_dbg(dev, "   context               :%p\n", urb->context);
+	dev_dbg(dev, "   complete              :%p\n", urb->complete);
+}
+EXPORT_SYMBOL_GPL(usbip_dump_urb);
+
+void usbip_dump_header(struct usbip_header *pdu)
+{
+	udbg("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
+			pdu->base.command,
+			pdu->base.seqnum,
+			pdu->base.devid,
+			pdu->base.direction,
+			pdu->base.ep);
+
+	switch (pdu->base.command) {
+	case USBIP_CMD_SUBMIT:
+		udbg("CMD_SUBMIT: x_flags %u x_len %u sf %u #p %u iv %u\n",
+				pdu->u.cmd_submit.transfer_flags,
+				pdu->u.cmd_submit.transfer_buffer_length,
+				pdu->u.cmd_submit.start_frame,
+				pdu->u.cmd_submit.number_of_packets,
+				pdu->u.cmd_submit.interval);
+				break;
+	case USBIP_CMD_UNLINK:
+		udbg("CMD_UNLINK: seq %u\n", pdu->u.cmd_unlink.seqnum);
+		break;
+	case USBIP_RET_SUBMIT:
+		udbg("RET_SUBMIT: st %d al %u sf %d ec %d\n",
+				pdu->u.ret_submit.status,
+				pdu->u.ret_submit.actual_length,
+				pdu->u.ret_submit.start_frame,
+				pdu->u.ret_submit.error_count);
+	case USBIP_RET_UNLINK:
+		udbg("RET_UNLINK: status %d\n", pdu->u.ret_unlink.status);
+		break;
+	default:
+		/* NOT REACHED */
+		udbg("UNKNOWN\n");
+	}
+}
+EXPORT_SYMBOL_GPL(usbip_dump_header);
+
+
+/*-------------------------------------------------------------------------*/
+/* thread routines */
+
+int usbip_thread(void *param)
+{
+	struct usbip_task *ut = param;
+
+	if (!ut)
+		return -EINVAL;
+
+	lock_kernel();
+	daemonize(ut->name);
+	allow_signal(SIGKILL);
+	ut->thread = current;
+	unlock_kernel();
+
+	/* srv.rb must wait for rx_thread starting */
+	complete(&ut->thread_done);
+
+	/* start of while loop */
+	ut->loop_ops(ut);
+
+	/* end of loop */
+	ut->thread = NULL;
+
+	complete_and_exit(&ut->thread_done, 0);
+}
+
+void usbip_start_threads(struct usbip_device *ud)
+{
+	/*
+	 * threads are invoked per one device (per one connection).
+	 */
+	kernel_thread(usbip_thread, (void *)&ud->tcp_rx, 0);
+	kernel_thread(usbip_thread, (void *)&ud->tcp_tx, 0);
+
+	/* confirm threads are starting */
+	wait_for_completion(&ud->tcp_rx.thread_done);
+	wait_for_completion(&ud->tcp_tx.thread_done);
+}
+EXPORT_SYMBOL_GPL(usbip_start_threads);
+
+void usbip_stop_threads(struct usbip_device *ud)
+{
+	/* kill threads related to this sdev, if v.c. exists */
+	if (ud->tcp_rx.thread != NULL) {
+		send_sig(SIGKILL, ud->tcp_rx.thread, 1);
+		wait_for_completion(&ud->tcp_rx.thread_done);
+		udbg("rx_thread for ud %p has finished\n", ud);
+	}
+
+	if (ud->tcp_tx.thread != NULL) {
+		send_sig(SIGKILL, ud->tcp_tx.thread, 1);
+		wait_for_completion(&ud->tcp_tx.thread_done);
+		udbg("tx_thread for ud %p has finished\n", ud);
+	}
+}
+EXPORT_SYMBOL_GPL(usbip_stop_threads);
+
+void usbip_task_init(struct usbip_task *ut, char *name,
+		void (*loop_ops)(struct usbip_task *))
+{
+	ut->thread = NULL;
+	init_completion(&ut->thread_done);
+	ut->name = name;
+	ut->loop_ops = loop_ops;
+}
+EXPORT_SYMBOL_GPL(usbip_task_init);
+
+
+/*-------------------------------------------------------------------------*/
+/* socket routines */
+
+ /*  Send/receive messages over TCP/IP. I refer drivers/block/nbd.c */
+int usbip_xmit(int send, struct socket *sock, char *buf,
+	       int size, int msg_flags)
+{
+	int result;
+	struct msghdr msg;
+	struct kvec iov;
+	int total = 0;
+
+	/* for blocks of if (dbg_flag_xmit) */
+	char *bp = buf;
+	int osize = size;
+
+	dbg_xmit("enter\n");
+
+	if (!sock || !buf || !size) {
+		printk(KERN_ERR "%s: invalid arg, sock %p buff %p size %d\n",
+		       __func__, sock, buf, size);
+		return -EINVAL;
+	}
+
+
+	if (dbg_flag_xmit) {
+		if (send) {
+			if (!in_interrupt())
+				printk(KERN_DEBUG "%-10s:", current->comm);
+			else
+				printk(KERN_DEBUG "interupt  :");
+
+			printk("%s: sending... , sock %p, buf %p, "
+			       "size %d, msg_flags %d\n", __func__,
+			       sock, buf, size, msg_flags);
+			usbip_dump_buffer(buf, size);
+		}
+	}
+
+
+	do {
+		sock->sk->sk_allocation = GFP_NOIO;
+		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_namelen    = 0;
+		msg.msg_flags      = msg_flags | MSG_NOSIGNAL;
+
+		if (send)
+			result = kernel_sendmsg(sock, &msg, &iov, 1, size);
+		else
+			result = kernel_recvmsg(sock, &msg, &iov, 1, size,
+								MSG_WAITALL);
+
+		if (result <= 0) {
+			udbg("usbip_xmit: %s sock %p buf %p size %u ret %d"
+					" total %d\n",
+					send ? "send" : "receive", sock, buf,
+					size, result, total);
+			goto err;
+		}
+
+		size -= result;
+		buf += result;
+		total += result;
+
+	} while (size > 0);
+
+
+	if (dbg_flag_xmit) {
+		if (!send) {
+			if (!in_interrupt())
+				printk(KERN_DEBUG "%-10s:", current->comm);
+			else
+				printk(KERN_DEBUG "interupt  :");
+
+			printk("usbip_xmit: receiving....\n");
+			usbip_dump_buffer(bp, osize);
+			printk("usbip_xmit: received, osize %d ret %d size %d "
+					"total %d\n", osize, result, size,
+					total);
+		}
+
+		if (send)
+			printk("usbip_xmit: send, total %d\n", total);
+	}
+
+	return total;
+
+err:
+	return result;
+}
+EXPORT_SYMBOL_GPL(usbip_xmit);
+
+
+/* now a usrland utility should set options. */
+#if 0
+int setquickack(struct socket *socket)
+{
+	mm_segment_t oldfs;
+	int val = 1;
+	int ret;
+
+	oldfs = get_fs();
+	set_fs(get_ds());
+	ret = socket->ops->setsockopt(socket, SOL_TCP, TCP_QUICKACK,
+			(char __user *) &val, sizeof(ret));
+	set_fs(oldfs);
+
+	return ret;
+}
+
+int setnodelay(struct socket *socket)
+{
+	mm_segment_t oldfs;
+	int val = 1;
+	int ret;
+
+	oldfs = get_fs();
+	set_fs(get_ds());
+	ret = socket->ops->setsockopt(socket, SOL_TCP, TCP_NODELAY,
+			(char __user *) &val, sizeof(ret));
+	set_fs(oldfs);
+
+	return ret;
+}
+
+int setkeepalive(struct socket *socket)
+{
+	mm_segment_t oldfs;
+	int val = 1;
+	int ret;
+
+	oldfs = get_fs();
+	set_fs(get_ds());
+	ret = socket->ops->setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE,
+			(char __user *) &val, sizeof(ret));
+	set_fs(oldfs);
+
+	return ret;
+}
+
+void setreuse(struct socket *socket)
+{
+	socket->sk->sk_reuse = 1;
+}
+#endif
+
+struct socket *sockfd_to_socket(unsigned int sockfd)
+{
+	struct socket *socket;
+	struct file *file;
+	struct inode *inode;
+
+	file = fget(sockfd);
+	if (!file) {
+		printk(KERN_ERR "%s: invalid sockfd\n", __func__);
+		return NULL;
+	}
+
+	inode = file->f_dentry->d_inode;
+
+	if (!inode || !S_ISSOCK(inode->i_mode))
+		return NULL;
+
+	socket = SOCKET_I(inode);
+
+	return socket;
+}
+EXPORT_SYMBOL_GPL(sockfd_to_socket);
+
+
+
+/*-------------------------------------------------------------------------*/
+/* pdu routines */
+
+/* there may be more cases to tweak the flags. */
+static unsigned int tweak_transfer_flags(unsigned int flags)
+{
+
+	if (flags & URB_NO_TRANSFER_DMA_MAP)
+		/*
+		 * vhci_hcd does not provide DMA-mapped I/O. The upper
+		 * driver does not need to set this flag. The remote
+		 * usbip.ko does not still perform DMA-mapped I/O for
+		 * DMA-caplable host controllers. So, clear this flag.
+		 */
+		flags &= ~URB_NO_TRANSFER_DMA_MAP;
+
+	if (flags & URB_NO_SETUP_DMA_MAP)
+		flags &= ~URB_NO_SETUP_DMA_MAP;
+
+	return flags;
+}
+
+static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
+								int pack)
+{
+	struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
+
+	/*
+	 * Some members are not still implemented in usbip. I hope this issue
+	 * will be discussed when usbip is ported to other operating systems.
+	 */
+	if (pack) {
+		/* vhci_tx.c */
+		spdu->transfer_flags =
+				tweak_transfer_flags(urb->transfer_flags);
+		spdu->transfer_buffer_length	= urb->transfer_buffer_length;
+		spdu->start_frame		= urb->start_frame;
+		spdu->number_of_packets		= urb->number_of_packets;
+		spdu->interval			= urb->interval;
+	} else  {
+		/* stub_rx.c */
+		urb->transfer_flags         = spdu->transfer_flags;
+
+		urb->transfer_buffer_length = spdu->transfer_buffer_length;
+		urb->start_frame            = spdu->start_frame;
+		urb->number_of_packets      = spdu->number_of_packets;
+		urb->interval               = spdu->interval;
+	}
+}
+
+static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
+								int pack)
+{
+	struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
+
+	if (pack) {
+		/* stub_tx.c */
+
+		rpdu->status		= urb->status;
+		rpdu->actual_length	= urb->actual_length;
+		rpdu->start_frame	= urb->start_frame;
+		rpdu->error_count	= urb->error_count;
+	} else {
+		/* vhci_rx.c */
+
+		urb->status		= rpdu->status;
+		urb->actual_length	= rpdu->actual_length;
+		urb->start_frame	= rpdu->start_frame;
+		urb->error_count	= rpdu->error_count;
+	}
+}
+
+
+void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
+								int pack)
+{
+	switch (cmd) {
+	case USBIP_CMD_SUBMIT:
+		usbip_pack_cmd_submit(pdu, urb, pack);
+		break;
+	case USBIP_RET_SUBMIT:
+		usbip_pack_ret_submit(pdu, urb, pack);
+		break;
+	default:
+		err("unknown command");
+		/* NOTREACHED */
+		/* BUG(); */
+	}
+}
+EXPORT_SYMBOL_GPL(usbip_pack_pdu);
+
+
+static void correct_endian_basic(struct usbip_header_basic *base, int send)
+{
+	if (send) {
+		base->command	= cpu_to_be32(base->command);
+		base->seqnum	= cpu_to_be32(base->seqnum);
+		base->devid	= cpu_to_be32(base->devid);
+		base->direction	= cpu_to_be32(base->direction);
+		base->ep	= cpu_to_be32(base->ep);
+	} else {
+		base->command	= be32_to_cpu(base->command);
+		base->seqnum	= be32_to_cpu(base->seqnum);
+		base->devid	= be32_to_cpu(base->devid);
+		base->direction	= be32_to_cpu(base->direction);
+		base->ep	= be32_to_cpu(base->ep);
+	}
+}
+
+static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
+								int send)
+{
+	if (send) {
+		pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
+
+		cpu_to_be32s(&pdu->transfer_buffer_length);
+		cpu_to_be32s(&pdu->start_frame);
+		cpu_to_be32s(&pdu->number_of_packets);
+		cpu_to_be32s(&pdu->interval);
+	} else {
+		pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
+
+		be32_to_cpus(&pdu->transfer_buffer_length);
+		be32_to_cpus(&pdu->start_frame);
+		be32_to_cpus(&pdu->number_of_packets);
+		be32_to_cpus(&pdu->interval);
+	}
+}
+
+static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
+								int send)
+{
+	if (send) {
+		cpu_to_be32s(&pdu->status);
+		cpu_to_be32s(&pdu->actual_length);
+		cpu_to_be32s(&pdu->start_frame);
+		cpu_to_be32s(&pdu->error_count);
+	} else {
+		be32_to_cpus(&pdu->status);
+		be32_to_cpus(&pdu->actual_length);
+		be32_to_cpus(&pdu->start_frame);
+		be32_to_cpus(&pdu->error_count);
+	}
+}
+
+static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
+								int send)
+{
+	if (send)
+		pdu->seqnum = cpu_to_be32(pdu->seqnum);
+	else
+		pdu->seqnum = be32_to_cpu(pdu->seqnum);
+}
+
+static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
+								int send)
+{
+	if (send)
+		cpu_to_be32s(&pdu->status);
+	else
+		be32_to_cpus(&pdu->status);
+}
+
+void usbip_header_correct_endian(struct usbip_header *pdu, int send)
+{
+	__u32 cmd = 0;
+
+	if (send)
+		cmd = pdu->base.command;
+
+	correct_endian_basic(&pdu->base, send);
+
+	if (!send)
+		cmd = pdu->base.command;
+
+	switch (cmd) {
+	case USBIP_CMD_SUBMIT:
+		correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
+		break;
+	case USBIP_RET_SUBMIT:
+		correct_endian_ret_submit(&pdu->u.ret_submit, send);
+		break;
+	case USBIP_CMD_UNLINK:
+		correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
+		break;
+	case USBIP_RET_UNLINK:
+		correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
+		break;
+	default:
+		/* NOTREACHED */
+		err("unknown command in pdu header: %d", cmd);
+		/* BUG(); */
+	}
+}
+EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
+
+static void usbip_iso_pakcet_correct_endian(
+				struct usbip_iso_packet_descriptor *iso,
+				int send)
+{
+	/* does not need all members. but copy all simply. */
+	if (send) {
+		iso->offset	= cpu_to_be32(iso->offset);
+		iso->length	= cpu_to_be32(iso->length);
+		iso->status	= cpu_to_be32(iso->status);
+		iso->actual_length = cpu_to_be32(iso->actual_length);
+	} else {
+		iso->offset	= be32_to_cpu(iso->offset);
+		iso->length	= be32_to_cpu(iso->length);
+		iso->status	= be32_to_cpu(iso->status);
+		iso->actual_length = be32_to_cpu(iso->actual_length);
+	}
+}
+
+static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
+		struct usb_iso_packet_descriptor *uiso, int pack)
+{
+	if (pack) {
+		iso->offset		= uiso->offset;
+		iso->length		= uiso->length;
+		iso->status		= uiso->status;
+		iso->actual_length	= uiso->actual_length;
+	} else {
+		uiso->offset		= iso->offset;
+		uiso->length		= iso->length;
+		uiso->status		= iso->status;
+		uiso->actual_length	= iso->actual_length;
+	}
+}
+
+
+/* must free buffer */
+void *usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
+{
+	void *buff;
+	struct usbip_iso_packet_descriptor *iso;
+	int np = urb->number_of_packets;
+	ssize_t size = np * sizeof(*iso);
+	int i;
+
+	buff = kzalloc(size, GFP_KERNEL);
+	if (!buff)
+		return NULL;
+
+	for (i = 0; i < np; i++) {
+		iso = buff + (i * sizeof(*iso));
+
+		usbip_pack_iso(iso, &urb->iso_frame_desc[i], 1);
+		usbip_iso_pakcet_correct_endian(iso, 1);
+	}
+
+	*bufflen = size;
+
+	return buff;
+}
+EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
+
+/* some members of urb must be substituted before. */
+int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
+{
+	void *buff;
+	struct usbip_iso_packet_descriptor *iso;
+	int np = urb->number_of_packets;
+	int size = np * sizeof(*iso);
+	int i;
+	int ret;
+
+	if (!usb_pipeisoc(urb->pipe))
+		return 0;
+
+	/* my Bluetooth dongle gets ISO URBs which are np = 0 */
+	if (np == 0) {
+		/* uinfo("iso np == 0\n"); */
+		/* usbip_dump_urb(urb); */
+		return 0;
+	}
+
+	buff = kzalloc(size, GFP_KERNEL);
+	if (!buff)
+		return -ENOMEM;
+
+	ret = usbip_xmit(0, ud->tcp_socket, buff, size, 0);
+	if (ret != size) {
+		dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
+			ret);
+		kfree(buff);
+
+		if (ud->side == USBIP_STUB)
+			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+		else
+			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+
+		return -EPIPE;
+	}
+
+	for (i = 0; i < np; i++) {
+		iso = buff + (i * sizeof(*iso));
+
+		usbip_iso_pakcet_correct_endian(iso, 0);
+		usbip_pack_iso(iso, &urb->iso_frame_desc[i], 0);
+	}
+
+
+	kfree(buff);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usbip_recv_iso);
+
+
+/* some members of urb must be substituted before. */
+int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
+{
+	int ret;
+	int size;
+
+	if (ud->side == USBIP_STUB) {
+		/* stub_rx.c */
+		/* the direction of urb must be OUT. */
+		if (usb_pipein(urb->pipe))
+			return 0;
+
+		size = urb->transfer_buffer_length;
+	} else {
+		/* vhci_rx.c */
+		/* the direction of urb must be IN. */
+		if (usb_pipeout(urb->pipe))
+			return 0;
+
+		size = urb->actual_length;
+	}
+
+	/* no need to recv xbuff */
+	if (!(size > 0))
+		return 0;
+
+	ret = usbip_xmit(0, ud->tcp_socket, (char *)urb->transfer_buffer,
+			 size, 0);
+	if (ret != size) {
+		dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
+		if (ud->side == USBIP_STUB) {
+			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+		} else {
+			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+			return -EPIPE;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
+
+
+/*-------------------------------------------------------------------------*/
+
+static int __init usbip_common_init(void)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "" DRIVER_VERSION);
+
+	return 0;
+}
+
+static void __exit usbip_common_exit(void)
+{
+	return;
+}
+
+
+
+
+module_init(usbip_common_init);
+module_exit(usbip_common_exit);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/usbip/usbip_common.h b/drivers/staging/usbip/usbip_common.h
new file mode 100644
index 000000000000..b0186b766375
--- /dev/null
+++ b/drivers/staging/usbip/usbip_common.h
@@ -0,0 +1,406 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This 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 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#ifndef __VHCI_COMMON_H
+#define __VHCI_COMMON_H
+
+
+#include <linux/version.h>
+#include <linux/usb.h>
+#include <asm/byteorder.h>
+#include <net/sock.h>
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * define macros to print messages
+ */
+
+/**
+ * udbg - print debug messages if CONFIG_USB_DEBUG is defined
+ * @fmt:
+ * @args:
+ */
+
+#ifdef CONFIG_USB_DEBUG
+
+#define udbg(fmt, args...)						\
+	do {								\
+		printk(KERN_DEBUG "%-10s:(%s,%d) %s: " fmt,		\
+			(in_interrupt() ? "interrupt" : (current)->comm),\
+			__FILE__, __LINE__, __func__, ##args);	\
+	} while (0)
+
+#else  /* CONFIG_USB_DEBUG */
+
+#define udbg(fmt, args...)		do { } while (0)
+
+#endif /* CONFIG_USB_DEBUG */
+
+
+enum {
+	usbip_debug_xmit	= (1 << 0),
+	usbip_debug_sysfs	= (1 << 1),
+	usbip_debug_urb		= (1 << 2),
+	usbip_debug_eh		= (1 << 3),
+
+	usbip_debug_stub_cmp	= (1 << 8),
+	usbip_debug_stub_dev	= (1 << 9),
+	usbip_debug_stub_rx	= (1 << 10),
+	usbip_debug_stub_tx	= (1 << 11),
+
+	usbip_debug_vhci_rh	= (1 << 8),
+	usbip_debug_vhci_hc	= (1 << 9),
+	usbip_debug_vhci_rx	= (1 << 10),
+	usbip_debug_vhci_tx	= (1 << 11),
+	usbip_debug_vhci_sysfs  = (1 << 12)
+};
+
+#define dbg_flag_xmit		(usbip_debug_flag & usbip_debug_xmit)
+#define dbg_flag_vhci_rh	(usbip_debug_flag & usbip_debug_vhci_rh)
+#define dbg_flag_vhci_hc	(usbip_debug_flag & usbip_debug_vhci_hc)
+#define dbg_flag_vhci_rx	(usbip_debug_flag & usbip_debug_vhci_rx)
+#define dbg_flag_vhci_tx	(usbip_debug_flag & usbip_debug_vhci_tx)
+#define dbg_flag_vhci_sysfs	(usbip_debug_flag & usbip_debug_vhci_sysfs)
+#define dbg_flag_stub_rx	(usbip_debug_flag & usbip_debug_stub_rx)
+#define dbg_flag_stub_tx	(usbip_debug_flag & usbip_debug_stub_tx)
+
+extern unsigned long usbip_debug_flag;
+extern struct device_attribute dev_attr_usbip_debug;
+
+#define dbg_with_flag(flag, fmt, args...)		\
+	do {						\
+		if (flag & usbip_debug_flag)		\
+			udbg(fmt , ##args);		\
+	} while (0)
+
+#define dbg_sysfs(fmt, args...)		\
+	dbg_with_flag(usbip_debug_sysfs, fmt , ##args)
+#define dbg_xmit(fmt, args...)		\
+	dbg_with_flag(usbip_debug_xmit, fmt , ##args)
+#define dbg_urb(fmt, args...)		\
+	dbg_with_flag(usbip_debug_urb, fmt , ##args)
+#define dbg_eh(fmt, args...)		\
+	dbg_with_flag(usbip_debug_eh, fmt , ##args)
+
+#define dbg_vhci_rh(fmt, args...)	\
+	dbg_with_flag(usbip_debug_vhci_rh, fmt , ##args)
+#define dbg_vhci_hc(fmt, args...)	\
+	dbg_with_flag(usbip_debug_vhci_hc, fmt , ##args)
+#define dbg_vhci_rx(fmt, args...)	\
+	dbg_with_flag(usbip_debug_vhci_rx, fmt , ##args)
+#define dbg_vhci_tx(fmt, args...)	\
+	dbg_with_flag(usbip_debug_vhci_tx, fmt , ##args)
+#define dbg_vhci_sysfs(fmt, args...)	\
+	dbg_with_flag(usbip_debug_vhci_sysfs, fmt , ##args)
+
+#define dbg_stub_cmp(fmt, args...)	\
+	dbg_with_flag(usbip_debug_stub_cmp, fmt , ##args)
+#define dbg_stub_rx(fmt, args...)	\
+	dbg_with_flag(usbip_debug_stub_rx, fmt , ##args)
+#define dbg_stub_tx(fmt, args...)	\
+	dbg_with_flag(usbip_debug_stub_tx, fmt , ##args)
+
+
+/**
+ * uerr - print error messages
+ * @fmt:
+ * @args:
+ */
+#define uerr(fmt, args...)						\
+	do {								\
+		printk(KERN_ERR "%-10s: ***ERROR*** (%s,%d) %s: " fmt,	\
+			(in_interrupt() ? "interrupt" : (current)->comm),\
+			__FILE__, __LINE__, __func__, ##args);	\
+	} while (0)
+
+/**
+ * uinfo - print information messages
+ * @fmt:
+ * @args:
+ */
+#define uinfo(fmt, args...)					\
+	do {							\
+		printk(KERN_INFO "usbip: " fmt , ## args);	\
+	} while (0)
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * USB/IP request headers.
+ * Currently, we define 4 request types:
+ *
+ *  - CMD_SUBMIT transfers a USB request, corresponding to usb_submit_urb().
+ *    (client to server)
+ *  - RET_RETURN transfers the result of CMD_SUBMIT.
+ *    (server to client)
+ *  - CMD_UNLINK transfers an unlink request of a pending USB request.
+ *    (client to server)
+ *  - RET_UNLINK transfers the result of CMD_UNLINK.
+ *    (server to client)
+ *
+ * Note: The below request formats are based on the USB subsystem of Linux. Its
+ * details will be defined when other implementations come.
+ *
+ *
+ */
+
+/*
+ * A basic header followed by other additional headers.
+ */
+struct usbip_header_basic {
+#define USBIP_CMD_SUBMIT	0x0001
+#define USBIP_CMD_UNLINK	0x0002
+#define USBIP_RET_SUBMIT	0x0003
+#define USBIP_RET_UNLINK	0x0004
+	__u32 command;
+
+	 /* sequencial number which identifies requests.
+	  * incremented per connections */
+	__u32 seqnum;
+
+	/* devid is used to specify a remote USB device uniquely instead
+	 * of busnum and devnum in Linux. In the case of Linux stub_driver,
+	 * this value is ((busnum << 16) | devnum) */
+	__u32 devid;
+
+#define USBIP_DIR_OUT	0
+#define USBIP_DIR_IN 	1
+	__u32 direction;
+	__u32 ep;     /* endpoint number */
+} __attribute__ ((packed));
+
+/*
+ * An additional header for a CMD_SUBMIT packet.
+ */
+struct usbip_header_cmd_submit {
+	/* these values are basically the same as in a URB. */
+
+	/* the same in a URB. */
+	__u32 transfer_flags;
+
+	/* set the following data size (out),
+	 * or expected reading data size (in) */
+	__s32 transfer_buffer_length;
+
+	/* it is difficult for usbip to sync frames (reserved only?) */
+	__s32 start_frame;
+
+	/* the number of iso descriptors that follows this header */
+	__s32 number_of_packets;
+
+	/* the maximum time within which this request works in a host
+	 * controller of a server side */
+	__s32 interval;
+
+	/* set setup packet data for a CTRL request */
+	unsigned char setup[8];
+} __attribute__ ((packed));
+
+/*
+ * An additional header for a RET_SUBMIT packet.
+ */
+struct usbip_header_ret_submit {
+	__s32 status;
+	__s32 actual_length; /* returned data length */
+	__s32 start_frame; /* ISO and INT */
+	__s32 number_of_packets;  /* ISO only */
+	__s32 error_count; /* ISO only */
+} __attribute__ ((packed));
+
+/*
+ * An additional header for a CMD_UNLINK packet.
+ */
+struct usbip_header_cmd_unlink {
+	__u32 seqnum; /* URB's seqnum which will be unlinked */
+} __attribute__ ((packed));
+
+
+/*
+ * An additional header for a RET_UNLINK packet.
+ */
+struct usbip_header_ret_unlink {
+	__s32 status;
+} __attribute__ ((packed));
+
+
+/* the same as usb_iso_packet_descriptor but packed for pdu */
+struct usbip_iso_packet_descriptor {
+	__u32 offset;
+	__u32 length;            /* expected length */
+	__u32 actual_length;
+	__u32 status;
+} __attribute__ ((packed));
+
+
+/*
+ * All usbip packets use a common header to keep code simple.
+ */
+struct usbip_header {
+	struct usbip_header_basic base;
+
+	union {
+		struct usbip_header_cmd_submit	cmd_submit;
+		struct usbip_header_ret_submit	ret_submit;
+		struct usbip_header_cmd_unlink	cmd_unlink;
+		struct usbip_header_ret_unlink	ret_unlink;
+	} u;
+} __attribute__ ((packed));
+
+
+
+
+/*-------------------------------------------------------------------------*/
+
+
+int usbip_xmit(int, struct socket *, char *, int, int);
+int usbip_sendmsg(struct socket *, struct msghdr *, int);
+
+
+static inline int interface_to_busnum(struct usb_interface *interface)
+{
+	struct usb_device *udev = interface_to_usbdev(interface);
+	return udev->bus->busnum;
+}
+
+static inline int interface_to_devnum(struct usb_interface *interface)
+{
+	struct usb_device *udev = interface_to_usbdev(interface);
+	return udev->devnum;
+}
+
+static inline int interface_to_infnum(struct usb_interface *interface)
+{
+	return interface->cur_altsetting->desc.bInterfaceNumber;
+}
+
+#if 0
+int setnodelay(struct socket *);
+int setquickack(struct socket *);
+int setkeepalive(struct socket *socket);
+void setreuse(struct socket *);
+#endif
+
+struct socket *sockfd_to_socket(unsigned int);
+int set_sockaddr(struct socket *socket, struct sockaddr_storage *ss);
+
+void usbip_dump_urb(struct urb *purb);
+void usbip_dump_header(struct usbip_header *pdu);
+
+
+struct usbip_device;
+
+struct usbip_task {
+	struct task_struct *thread;
+	struct completion thread_done;
+	char *name;
+	void (*loop_ops)(struct usbip_task *);
+};
+
+enum usbip_side {
+	USBIP_VHCI,
+	USBIP_STUB,
+};
+
+enum usbip_status {
+	/* sdev is available. */
+	SDEV_ST_AVAILABLE = 0x01,
+	/* sdev is now used. */
+	SDEV_ST_USED,
+	/* sdev is unusable because of a fatal error. */
+	SDEV_ST_ERROR,
+
+	/* vdev does not connect a remote device. */
+	VDEV_ST_NULL,
+	/* vdev is used, but the USB address is not assigned yet */
+	VDEV_ST_NOTASSIGNED,
+	VDEV_ST_USED,
+	VDEV_ST_ERROR
+};
+
+/* a common structure for stub_device and vhci_device */
+struct usbip_device {
+	enum usbip_side side;
+
+	enum usbip_status status;
+
+	/* lock for status */
+	spinlock_t lock;
+
+	struct socket *tcp_socket;
+
+	struct usbip_task tcp_rx;
+	struct usbip_task tcp_tx;
+
+	/* event handler */
+#define USBIP_EH_SHUTDOWN	(1 << 0)
+#define USBIP_EH_BYE		(1 << 1)
+#define USBIP_EH_RESET		(1 << 2)
+#define USBIP_EH_UNUSABLE	(1 << 3)
+
+#define SDEV_EVENT_REMOVED	(USBIP_EH_SHUTDOWN | USBIP_EH_RESET | USBIP_EH_BYE)
+#define	SDEV_EVENT_DOWN		(USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
+#define	SDEV_EVENT_ERROR_TCP	(USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
+#define	SDEV_EVENT_ERROR_SUBMIT	(USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
+#define	SDEV_EVENT_ERROR_MALLOC	(USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)
+
+#define	VDEV_EVENT_REMOVED	(USBIP_EH_SHUTDOWN | USBIP_EH_BYE)
+#define	VDEV_EVENT_DOWN		(USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
+#define	VDEV_EVENT_ERROR_TCP	(USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
+#define	VDEV_EVENT_ERROR_MALLOC	(USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)
+
+	unsigned long event;
+	struct usbip_task eh;
+	wait_queue_head_t eh_waitq;
+
+	struct eh_ops {
+		void (*shutdown)(struct usbip_device *);
+		void (*reset)(struct usbip_device *);
+		void (*unusable)(struct usbip_device *);
+	} eh_ops;
+};
+
+
+void usbip_task_init(struct usbip_task *ut, char *,
+				void (*loop_ops)(struct usbip_task *));
+
+void usbip_start_threads(struct usbip_device *ud);
+void usbip_stop_threads(struct usbip_device *ud);
+int usbip_thread(void *param);
+
+void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
+								int pack);
+
+void usbip_header_correct_endian(struct usbip_header *pdu, int send);
+/* some members of urb must be substituted before. */
+int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb);
+/* some members of urb must be substituted before. */
+int usbip_recv_iso(struct usbip_device *ud, struct urb *urb);
+void *usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen);
+
+
+/* usbip_event.c */
+void usbip_start_eh(struct usbip_device *ud);
+void usbip_stop_eh(struct usbip_device *ud);
+void usbip_event_add(struct usbip_device *ud, unsigned long event);
+int usbip_event_happend(struct usbip_device *ud);
+
+
+#endif
diff --git a/drivers/staging/usbip/usbip_event.c b/drivers/staging/usbip/usbip_event.c
new file mode 100644
index 000000000000..4318553ab20c
--- /dev/null
+++ b/drivers/staging/usbip/usbip_event.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This 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 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include "usbip_common.h"
+
+static int event_handler(struct usbip_device *ud)
+{
+	dbg_eh("enter\n");
+
+	/*
+	 * Events are handled by only this thread.
+	 */
+	while (usbip_event_happend(ud)) {
+		dbg_eh("pending event %lx\n", ud->event);
+
+		/*
+		 * NOTE: shutdown must come first.
+		 * Shutdown the device.
+		 */
+		if (ud->event & USBIP_EH_SHUTDOWN) {
+			ud->eh_ops.shutdown(ud);
+
+			ud->event &= ~USBIP_EH_SHUTDOWN;
+
+			break;
+		}
+
+		/* Stop the error handler. */
+		if (ud->event & USBIP_EH_BYE)
+			return -1;
+
+		/* Reset the device. */
+		if (ud->event & USBIP_EH_RESET) {
+			ud->eh_ops.reset(ud);
+
+			ud->event &= ~USBIP_EH_RESET;
+
+			break;
+		}
+
+		/* Mark the device as unusable. */
+		if (ud->event & USBIP_EH_UNUSABLE) {
+			ud->eh_ops.unusable(ud);
+
+			ud->event &= ~USBIP_EH_UNUSABLE;
+
+			break;
+		}
+
+		/* NOTREACHED */
+		printk(KERN_ERR "%s: unknown event\n", __func__);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void event_handler_loop(struct usbip_task *ut)
+{
+	struct usbip_device *ud = container_of(ut, struct usbip_device, eh);
+
+	while (1) {
+		if (signal_pending(current)) {
+			dbg_eh("signal catched!\n");
+			break;
+		}
+
+		if (event_handler(ud) < 0)
+			break;
+
+		wait_event_interruptible(ud->eh_waitq, usbip_event_happend(ud));
+		dbg_eh("wakeup\n");
+	}
+}
+
+void usbip_start_eh(struct usbip_device *ud)
+{
+	struct usbip_task *eh = &ud->eh;
+
+	init_waitqueue_head(&ud->eh_waitq);
+	ud->event = 0;
+
+	usbip_task_init(eh, "usbip_eh", event_handler_loop);
+
+	kernel_thread(usbip_thread, (void *)eh, 0);
+
+	wait_for_completion(&eh->thread_done);
+}
+EXPORT_SYMBOL_GPL(usbip_start_eh);
+
+void usbip_stop_eh(struct usbip_device *ud)
+{
+	struct usbip_task *eh = &ud->eh;
+
+	wait_for_completion(&eh->thread_done);
+	dbg_eh("usbip_eh has finished\n");
+}
+EXPORT_SYMBOL_GPL(usbip_stop_eh);
+
+void usbip_event_add(struct usbip_device *ud, unsigned long event)
+{
+	spin_lock(&ud->lock);
+
+	ud->event |= event;
+
+	wake_up(&ud->eh_waitq);
+
+	spin_unlock(&ud->lock);
+}
+EXPORT_SYMBOL_GPL(usbip_event_add);
+
+int usbip_event_happend(struct usbip_device *ud)
+{
+	int happend = 0;
+
+	spin_lock(&ud->lock);
+
+	if (ud->event != 0)
+		happend = 1;
+
+	spin_unlock(&ud->lock);
+
+	return happend;
+}
+EXPORT_SYMBOL_GPL(usbip_event_happend);