linux/drivers/usb/mon/mon_main.c

// SPDX-License-Identifier: GPL-2.0
/*
 * The USB Monitor, inspired by Dave Harding's USBMon.
 *
 * mon_main.c: Main file, module initiation and exit, registrations, etc.
 *
 * Copyright (C) 2005 Pete Zaitcev ([email protected])
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/slab.h>
#include <linux/notifier.h>
#include <linux/mutex.h>

#include "usb_mon.h"


static void mon_stop(struct mon_bus *mbus);
static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus);
static void mon_bus_drop(struct kref *r);
static void mon_bus_init(struct usb_bus *ubus);

DEFINE_MUTEX(…) …;

struct mon_bus mon_bus0;		/* Pseudo bus meaning "all buses" */
static LIST_HEAD(mon_buses);		/* All buses we know: struct mon_bus */

/*
 * Link a reader into the bus.
 *
 * This must be called with mon_lock taken because of mbus->ref.
 */
void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r)
{ … }

/*
 * Unlink reader from the bus.
 *
 * This is called with mon_lock taken, so we can decrement mbus->ref.
 */
void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r)
{ … }

/*
 */
static void mon_bus_submit(struct mon_bus *mbus, struct urb *urb)
{ … }

static void mon_submit(struct usb_bus *ubus, struct urb *urb)
{ … }

/*
 */
static void mon_bus_submit_error(struct mon_bus *mbus, struct urb *urb, int error)
{ … }

static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
{ … }

/*
 */
static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb, int status)
{ … }

static void mon_complete(struct usb_bus *ubus, struct urb *urb, int status)
{ … }

/* int (*unlink_urb) (struct urb *urb, int status); */

/*
 * Stop monitoring.
 */
static void mon_stop(struct mon_bus *mbus)
{ … }

/*
 * Add a USB bus (usually by a modprobe foo-hcd)
 *
 * This does not return an error code because the core cannot care less
 * if monitoring is not established.
 */
static void mon_bus_add(struct usb_bus *ubus)
{ … }

/*
 * Remove a USB bus (either from rmmod foo-hcd or from a hot-remove event).
 */
static void mon_bus_remove(struct usb_bus *ubus)
{ … }

static int mon_notify(struct notifier_block *self, unsigned long action,
		      void *dev)
{ … }

static struct notifier_block mon_nb = …;

/*
 * Ops
 */
static const struct usb_mon_operations mon_ops_0 = …;

/*
 * Tear usb_bus and mon_bus apart.
 */
static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus)
{ … }

/*
 */
static void mon_bus_drop(struct kref *r)
{ … }

/*
 * Initialize a bus for us:
 *  - allocate mon_bus
 *  - refcount USB bus struct
 *  - link
 */
static void mon_bus_init(struct usb_bus *ubus)
{ … }

static void mon_bus0_init(void)
{ … }

/*
 * Search a USB bus by number. Notice that USB bus numbers start from one,
 * which we may later use to identify "all" with zero.
 *
 * This function must be called with mon_lock held.
 *
 * This is obviously inefficient and may be revised in the future.
 */
struct mon_bus *mon_bus_lookup(unsigned int num)
{ … }

static int __init mon_init(void)
{ … }

static void __exit mon_exit(void)
{ … }

module_init(…) …;
module_exit(mon_exit);

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;