2 * The USB Monitor, inspired by Dave Harding's USBMon.
4 * mon_main.c: Main file, module initiation and exit, registrations, etc.
6 * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/usb.h>
12 #include <linux/notifier.h>
13 #include <linux/mutex.h>
16 #include "../core/hcd.h"
18 static void mon_stop(struct mon_bus
*mbus
);
19 static void mon_dissolve(struct mon_bus
*mbus
, struct usb_bus
*ubus
);
20 static void mon_bus_drop(struct kref
*r
);
21 static void mon_bus_init(struct usb_bus
*ubus
);
23 DEFINE_MUTEX(mon_lock
);
25 struct mon_bus mon_bus0
; /* Pseudo bus meaning "all buses" */
26 static LIST_HEAD(mon_buses
); /* All buses we know: struct mon_bus */
29 * Link a reader into the bus.
31 * This must be called with mon_lock taken because of mbus->ref.
33 void mon_reader_add(struct mon_bus
*mbus
, struct mon_reader
*r
)
38 spin_lock_irqsave(&mbus
->lock
, flags
);
39 if (mbus
->nreaders
== 0) {
40 if (mbus
== &mon_bus0
) {
41 list_for_each (p
, &mon_buses
) {
43 m1
= list_entry(p
, struct mon_bus
, bus_link
);
44 m1
->u_bus
->monitored
= 1;
47 mbus
->u_bus
->monitored
= 1;
51 list_add_tail(&r
->r_link
, &mbus
->r_list
);
52 spin_unlock_irqrestore(&mbus
->lock
, flags
);
58 * Unlink reader from the bus.
60 * This is called with mon_lock taken, so we can decrement mbus->ref.
62 void mon_reader_del(struct mon_bus
*mbus
, struct mon_reader
*r
)
66 spin_lock_irqsave(&mbus
->lock
, flags
);
69 if (mbus
->nreaders
== 0)
71 spin_unlock_irqrestore(&mbus
->lock
, flags
);
73 kref_put(&mbus
->ref
, mon_bus_drop
);
78 static void mon_bus_submit(struct mon_bus
*mbus
, struct urb
*urb
)
81 struct list_head
*pos
;
84 spin_lock_irqsave(&mbus
->lock
, flags
);
86 list_for_each (pos
, &mbus
->r_list
) {
87 r
= list_entry(pos
, struct mon_reader
, r_link
);
88 r
->rnf_submit(r
->r_data
, urb
);
90 spin_unlock_irqrestore(&mbus
->lock
, flags
);
94 static void mon_submit(struct usb_bus
*ubus
, struct urb
*urb
)
98 if ((mbus
= ubus
->mon_bus
) != NULL
)
99 mon_bus_submit(mbus
, urb
);
100 mon_bus_submit(&mon_bus0
, urb
);
105 static void mon_bus_submit_error(struct mon_bus
*mbus
, struct urb
*urb
, int error
)
108 struct list_head
*pos
;
109 struct mon_reader
*r
;
111 spin_lock_irqsave(&mbus
->lock
, flags
);
113 list_for_each (pos
, &mbus
->r_list
) {
114 r
= list_entry(pos
, struct mon_reader
, r_link
);
115 r
->rnf_error(r
->r_data
, urb
, error
);
117 spin_unlock_irqrestore(&mbus
->lock
, flags
);
121 static void mon_submit_error(struct usb_bus
*ubus
, struct urb
*urb
, int error
)
123 struct mon_bus
*mbus
;
125 if ((mbus
= ubus
->mon_bus
) != NULL
)
126 mon_bus_submit_error(mbus
, urb
, error
);
127 mon_bus_submit_error(&mon_bus0
, urb
, error
);
132 static void mon_bus_complete(struct mon_bus
*mbus
, struct urb
*urb
)
135 struct list_head
*pos
;
136 struct mon_reader
*r
;
138 spin_lock_irqsave(&mbus
->lock
, flags
);
140 list_for_each (pos
, &mbus
->r_list
) {
141 r
= list_entry(pos
, struct mon_reader
, r_link
);
142 r
->rnf_complete(r
->r_data
, urb
);
144 spin_unlock_irqrestore(&mbus
->lock
, flags
);
147 static void mon_complete(struct usb_bus
*ubus
, struct urb
*urb
)
149 struct mon_bus
*mbus
;
151 mbus
= ubus
->mon_bus
;
154 * This should not happen.
155 * At this point we do not even know the bus number...
157 printk(KERN_ERR TAG
": Null mon bus in URB, pipe 0x%x\n",
162 mon_bus_complete(mbus
, urb
);
163 mon_bus_complete(&mon_bus0
, urb
);
166 /* int (*unlink_urb) (struct urb *urb, int status); */
171 static void mon_stop(struct mon_bus
*mbus
)
173 struct usb_bus
*ubus
= mbus
->u_bus
;
176 if (mbus
== &mon_bus0
) {
177 list_for_each (p
, &mon_buses
) {
178 mbus
= list_entry(p
, struct mon_bus
, bus_link
);
180 * We do not change nreaders here, so rely on mon_lock.
182 if (mbus
->nreaders
== 0 && (ubus
= mbus
->u_bus
) != NULL
)
187 * A stop can be called for a dissolved mon_bus in case of
188 * a reader staying across an rmmod foo_hcd, so test ->u_bus.
190 if (mon_bus0
.nreaders
== 0 && (ubus
= mbus
->u_bus
) != NULL
) {
198 * Add a USB bus (usually by a modprobe foo-hcd)
200 * This does not return an error code because the core cannot care less
201 * if monitoring is not established.
203 static void mon_bus_add(struct usb_bus
*ubus
)
206 mutex_lock(&mon_lock
);
207 if (mon_bus0
.nreaders
!= 0)
209 mutex_unlock(&mon_lock
);
213 * Remove a USB bus (either from rmmod foo-hcd or from a hot-remove event).
215 static void mon_bus_remove(struct usb_bus
*ubus
)
217 struct mon_bus
*mbus
= ubus
->mon_bus
;
219 mutex_lock(&mon_lock
);
220 list_del(&mbus
->bus_link
);
221 if (mbus
->text_inited
)
223 if (mbus
->bin_inited
)
226 mon_dissolve(mbus
, ubus
);
227 kref_put(&mbus
->ref
, mon_bus_drop
);
228 mutex_unlock(&mon_lock
);
231 static int mon_notify(struct notifier_block
*self
, unsigned long action
,
244 static struct notifier_block mon_nb
= {
245 .notifier_call
= mon_notify
,
251 static struct usb_mon_operations mon_ops_0
= {
252 .urb_submit
= mon_submit
,
253 .urb_submit_error
= mon_submit_error
,
254 .urb_complete
= mon_complete
,
258 * Tear usb_bus and mon_bus apart.
260 static void mon_dissolve(struct mon_bus
*mbus
, struct usb_bus
*ubus
)
263 if (ubus
->monitored
) {
268 ubus
->mon_bus
= NULL
;
272 /* We want synchronize_irq() here, but that needs an argument. */
277 static void mon_bus_drop(struct kref
*r
)
279 struct mon_bus
*mbus
= container_of(r
, struct mon_bus
, ref
);
284 * Initialize a bus for us:
286 * - refcount USB bus struct
289 static void mon_bus_init(struct usb_bus
*ubus
)
291 struct mon_bus
*mbus
;
293 if ((mbus
= kzalloc(sizeof(struct mon_bus
), GFP_KERNEL
)) == NULL
)
295 kref_init(&mbus
->ref
);
296 spin_lock_init(&mbus
->lock
);
297 INIT_LIST_HEAD(&mbus
->r_list
);
300 * We don't need to take a reference to ubus, because we receive
301 * a notification if the bus is about to be removed.
304 ubus
->mon_bus
= mbus
;
306 mbus
->text_inited
= mon_text_add(mbus
, ubus
);
307 mbus
->bin_inited
= mon_bin_add(mbus
, ubus
);
309 mutex_lock(&mon_lock
);
310 list_add_tail(&mbus
->bus_link
, &mon_buses
);
311 mutex_unlock(&mon_lock
);
318 static void mon_bus0_init(void)
320 struct mon_bus
*mbus
= &mon_bus0
;
322 kref_init(&mbus
->ref
);
323 spin_lock_init(&mbus
->lock
);
324 INIT_LIST_HEAD(&mbus
->r_list
);
326 mbus
->text_inited
= mon_text_add(mbus
, NULL
);
327 mbus
->bin_inited
= mon_bin_add(mbus
, NULL
);
331 * Search a USB bus by number. Notice that USB bus numbers start from one,
332 * which we may later use to identify "all" with zero.
334 * This function must be called with mon_lock held.
336 * This is obviously inefficient and may be revised in the future.
338 struct mon_bus
*mon_bus_lookup(unsigned int num
)
341 struct mon_bus
*mbus
;
346 list_for_each (p
, &mon_buses
) {
347 mbus
= list_entry(p
, struct mon_bus
, bus_link
);
348 if (mbus
->u_bus
->busnum
== num
) {
355 static int __init
mon_init(void)
357 struct usb_bus
*ubus
;
360 if ((rc
= mon_text_init()) != 0)
362 if ((rc
= mon_bin_init()) != 0)
367 if (usb_mon_register(&mon_ops_0
) != 0) {
368 printk(KERN_NOTICE TAG
": unable to register with the core\n");
372 // MOD_INC_USE_COUNT(which_module?);
374 usb_register_notify(&mon_nb
);
376 mutex_lock(&usb_bus_list_lock
);
377 list_for_each_entry (ubus
, &usb_bus_list
, bus_list
) {
380 mutex_unlock(&usb_bus_list_lock
);
391 static void __exit
mon_exit(void)
393 struct mon_bus
*mbus
;
396 usb_unregister_notify(&mon_nb
);
397 usb_mon_deregister();
399 mutex_lock(&mon_lock
);
401 while (!list_empty(&mon_buses
)) {
403 mbus
= list_entry(p
, struct mon_bus
, bus_link
);
406 if (mbus
->text_inited
)
408 if (mbus
->bin_inited
)
412 * This never happens, because the open/close paths in
413 * file level maintain module use counters and so rmmod fails
414 * before reaching here. However, better be safe...
416 if (mbus
->nreaders
) {
418 ": Outstanding opens (%d) on usb%d, leaking...\n",
419 mbus
->nreaders
, mbus
->u_bus
->busnum
);
420 atomic_set(&mbus
->ref
.refcount
, 2); /* Force leak */
423 mon_dissolve(mbus
, mbus
->u_bus
);
424 kref_put(&mbus
->ref
, mon_bus_drop
);
428 if (mbus
->text_inited
)
430 if (mbus
->bin_inited
)
433 mutex_unlock(&mon_lock
);
439 module_init(mon_init
);
440 module_exit(mon_exit
);
442 MODULE_LICENSE("GPL");