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

drivers/staging/Kconfig

@@ -33,4 +33,6 @@ source "drivers/staging/me4000/Kconfig"
 
 source "drivers/staging/go7007/Kconfig"
 
+source "drivers/staging/usbip/Kconfig"
+
 endif # STAGING

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/

drivers/staging/usbip/Kconfig

+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.

drivers/staging/usbip/Makefile

+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

drivers/staging/usbip/README

+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>

drivers/staging/usbip/usbip_common.h

+/*
+ * 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

drivers/staging/usbip/usbip_event.c

+/*
+ * 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);