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1/*
2 * The USB Monitor, inspired by Dave Harding's USBMon.
3 *
4 * This is a text format reader.
5 */
6
7#include <linux/kernel.h>
8#include <linux/list.h>
9#include <linux/usb.h>
10#include <linux/slab.h>
11#include <linux/time.h>
12#include <linux/mutex.h>
13#include <linux/debugfs.h>
14#include <linux/scatterlist.h>
15#include <asm/uaccess.h>
16
17#include "usb_mon.h"
18
19/*
20 * No, we do not want arbitrarily long data strings.
21 * Use the binary interface if you want to capture bulk data!
22 */
23#define DATA_MAX 32
24
25/*
26 * Defined by USB 2.0 clause 9.3, table 9.2.
27 */
28#define SETUP_MAX 8
29
30/*
31 * This limit exists to prevent OOMs when the user process stops reading.
32 * If usbmon were available to unprivileged processes, it might be open
33 * to a local DoS. But we have to keep to root in order to prevent
34 * password sniffing from HID devices.
35 */
36#define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text))
37
38/*
39 * Potentially unlimited number; we limit it for similar allocations.
40 * The usbfs limits this to 128, but we're not quite as generous.
41 */
42#define ISODESC_MAX 5
43
44#define PRINTF_DFL 250 /* with 5 ISOs segs */
45
46struct mon_iso_desc {
47 int status;
48 unsigned int offset;
49 unsigned int length; /* Unsigned here, signed in URB. Historic. */
50};
51
52struct mon_event_text {
53 struct list_head e_link;
54 int type; /* submit, complete, etc. */
55 unsigned long id; /* From pointer, most of the time */
56 unsigned int tstamp;
57 int busnum;
58 char devnum;
59 char epnum;
60 char is_in;
61 char xfertype;
62 int length; /* Depends on type: xfer length or act length */
63 int status;
64 int interval;
65 int start_frame;
66 int error_count;
67 char setup_flag;
68 char data_flag;
69 int numdesc; /* Full number */
70 struct mon_iso_desc isodesc[ISODESC_MAX];
71 unsigned char setup[SETUP_MAX];
72 unsigned char data[DATA_MAX];
73};
74
75#define SLAB_NAME_SZ 30
76struct mon_reader_text {
77 struct kmem_cache *e_slab;
78 int nevents;
79 struct list_head e_list;
80 struct mon_reader r; /* In C, parent class can be placed anywhere */
81
82 wait_queue_head_t wait;
83 int printf_size;
84 char *printf_buf;
85 struct mutex printf_lock;
86
87 char slab_name[SLAB_NAME_SZ];
88};
89
90static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */
91
92static void mon_text_ctor(void *);
93
94struct mon_text_ptr {
95 int cnt, limit;
96 char *pbuf;
97};
98
99static struct mon_event_text *
100 mon_text_read_wait(struct mon_reader_text *rp, struct file *file);
101static void mon_text_read_head_t(struct mon_reader_text *rp,
102 struct mon_text_ptr *p, const struct mon_event_text *ep);
103static void mon_text_read_head_u(struct mon_reader_text *rp,
104 struct mon_text_ptr *p, const struct mon_event_text *ep);
105static void mon_text_read_statset(struct mon_reader_text *rp,
106 struct mon_text_ptr *p, const struct mon_event_text *ep);
107static void mon_text_read_intstat(struct mon_reader_text *rp,
108 struct mon_text_ptr *p, const struct mon_event_text *ep);
109static void mon_text_read_isostat(struct mon_reader_text *rp,
110 struct mon_text_ptr *p, const struct mon_event_text *ep);
111static void mon_text_read_isodesc(struct mon_reader_text *rp,
112 struct mon_text_ptr *p, const struct mon_event_text *ep);
113static void mon_text_read_data(struct mon_reader_text *rp,
114 struct mon_text_ptr *p, const struct mon_event_text *ep);
115
116/*
117 * mon_text_submit
118 * mon_text_complete
119 *
120 * May be called from an interrupt.
121 *
122 * This is called with the whole mon_bus locked, so no additional lock.
123 */
124
125static inline char mon_text_get_setup(struct mon_event_text *ep,
126 struct urb *urb, char ev_type, struct mon_bus *mbus)
127{
128
129 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S')
130 return '-';
131
132 if (urb->setup_packet == NULL)
133 return 'Z'; /* '0' would be not as pretty. */
134
135 memcpy(ep->setup, urb->setup_packet, SETUP_MAX);
136 return 0;
137}
138
139static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
140 int len, char ev_type, struct mon_bus *mbus)
141{
142 void *src;
143
144 if (len <= 0)
145 return 'L';
146 if (len >= DATA_MAX)
147 len = DATA_MAX;
148
149 if (ep->is_in) {
150 if (ev_type != 'C')
151 return '<';
152 } else {
153 if (ev_type != 'S')
154 return '>';
155 }
156
157 if (urb->num_sgs == 0) {
158 src = urb->transfer_buffer;
159 if (src == NULL)
160 return 'Z'; /* '0' would be not as pretty. */
161 } else {
162 struct scatterlist *sg = urb->sg;
163
164 if (PageHighMem(sg_page(sg)))
165 return 'D';
166
167 /* For the text interface we copy only the first sg buffer */
168 len = min_t(int, sg->length, len);
169 src = sg_virt(sg);
170 }
171
172 memcpy(ep->data, src, len);
173 return 0;
174}
175
176static inline unsigned int mon_get_timestamp(void)
177{
178 struct timeval tval;
179 unsigned int stamp;
180
181 do_gettimeofday(&tval);
182 stamp = tval.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */
183 stamp = stamp * 1000000 + tval.tv_usec;
184 return stamp;
185}
186
187static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
188 char ev_type, int status)
189{
190 struct mon_event_text *ep;
191 unsigned int stamp;
192 struct usb_iso_packet_descriptor *fp;
193 struct mon_iso_desc *dp;
194 int i, ndesc;
195
196 stamp = mon_get_timestamp();
197
198 if (rp->nevents >= EVENT_MAX ||
199 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
200 rp->r.m_bus->cnt_text_lost++;
201 return;
202 }
203
204 ep->type = ev_type;
205 ep->id = (unsigned long) urb;
206 ep->busnum = urb->dev->bus->busnum;
207 ep->devnum = urb->dev->devnum;
208 ep->epnum = usb_endpoint_num(&urb->ep->desc);
209 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
210 ep->is_in = usb_urb_dir_in(urb);
211 ep->tstamp = stamp;
212 ep->length = (ev_type == 'S') ?
213 urb->transfer_buffer_length : urb->actual_length;
214 /* Collecting status makes debugging sense for submits, too */
215 ep->status = status;
216
217 if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
218 ep->interval = urb->interval;
219 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
220 ep->interval = urb->interval;
221 ep->start_frame = urb->start_frame;
222 ep->error_count = urb->error_count;
223 }
224 ep->numdesc = urb->number_of_packets;
225 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC &&
226 urb->number_of_packets > 0) {
227 if ((ndesc = urb->number_of_packets) > ISODESC_MAX)
228 ndesc = ISODESC_MAX;
229 fp = urb->iso_frame_desc;
230 dp = ep->isodesc;
231 for (i = 0; i < ndesc; i++) {
232 dp->status = fp->status;
233 dp->offset = fp->offset;
234 dp->length = (ev_type == 'S') ?
235 fp->length : fp->actual_length;
236 fp++;
237 dp++;
238 }
239 /* Wasteful, but simple to understand: ISO 'C' is sparse. */
240 if (ev_type == 'C')
241 ep->length = urb->transfer_buffer_length;
242 }
243
244 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus);
245 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type,
246 rp->r.m_bus);
247
248 rp->nevents++;
249 list_add_tail(&ep->e_link, &rp->e_list);
250 wake_up(&rp->wait);
251}
252
253static void mon_text_submit(void *data, struct urb *urb)
254{
255 struct mon_reader_text *rp = data;
256 mon_text_event(rp, urb, 'S', -EINPROGRESS);
257}
258
259static void mon_text_complete(void *data, struct urb *urb, int status)
260{
261 struct mon_reader_text *rp = data;
262 mon_text_event(rp, urb, 'C', status);
263}
264
265static void mon_text_error(void *data, struct urb *urb, int error)
266{
267 struct mon_reader_text *rp = data;
268 struct mon_event_text *ep;
269
270 if (rp->nevents >= EVENT_MAX ||
271 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
272 rp->r.m_bus->cnt_text_lost++;
273 return;
274 }
275
276 ep->type = 'E';
277 ep->id = (unsigned long) urb;
278 ep->busnum = urb->dev->bus->busnum;
279 ep->devnum = urb->dev->devnum;
280 ep->epnum = usb_endpoint_num(&urb->ep->desc);
281 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
282 ep->is_in = usb_urb_dir_in(urb);
283 ep->tstamp = mon_get_timestamp();
284 ep->length = 0;
285 ep->status = error;
286
287 ep->setup_flag = '-';
288 ep->data_flag = 'E';
289
290 rp->nevents++;
291 list_add_tail(&ep->e_link, &rp->e_list);
292 wake_up(&rp->wait);
293}
294
295/*
296 * Fetch next event from the circular buffer.
297 */
298static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp,
299 struct mon_bus *mbus)
300{
301 struct list_head *p;
302 unsigned long flags;
303
304 spin_lock_irqsave(&mbus->lock, flags);
305 if (list_empty(&rp->e_list)) {
306 spin_unlock_irqrestore(&mbus->lock, flags);
307 return NULL;
308 }
309 p = rp->e_list.next;
310 list_del(p);
311 --rp->nevents;
312 spin_unlock_irqrestore(&mbus->lock, flags);
313 return list_entry(p, struct mon_event_text, e_link);
314}
315
316/*
317 */
318static int mon_text_open(struct inode *inode, struct file *file)
319{
320 struct mon_bus *mbus;
321 struct mon_reader_text *rp;
322 int rc;
323
324 mutex_lock(&mon_lock);
325 mbus = inode->i_private;
326
327 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
328 if (rp == NULL) {
329 rc = -ENOMEM;
330 goto err_alloc;
331 }
332 INIT_LIST_HEAD(&rp->e_list);
333 init_waitqueue_head(&rp->wait);
334 mutex_init(&rp->printf_lock);
335
336 rp->printf_size = PRINTF_DFL;
337 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL);
338 if (rp->printf_buf == NULL) {
339 rc = -ENOMEM;
340 goto err_alloc_pr;
341 }
342
343 rp->r.m_bus = mbus;
344 rp->r.r_data = rp;
345 rp->r.rnf_submit = mon_text_submit;
346 rp->r.rnf_error = mon_text_error;
347 rp->r.rnf_complete = mon_text_complete;
348
349 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp);
350 rp->e_slab = kmem_cache_create(rp->slab_name,
351 sizeof(struct mon_event_text), sizeof(long), 0,
352 mon_text_ctor);
353 if (rp->e_slab == NULL) {
354 rc = -ENOMEM;
355 goto err_slab;
356 }
357
358 mon_reader_add(mbus, &rp->r);
359
360 file->private_data = rp;
361 mutex_unlock(&mon_lock);
362 return 0;
363
364// err_busy:
365// kmem_cache_destroy(rp->e_slab);
366err_slab:
367 kfree(rp->printf_buf);
368err_alloc_pr:
369 kfree(rp);
370err_alloc:
371 mutex_unlock(&mon_lock);
372 return rc;
373}
374
375/*
376 * For simplicity, we read one record in one system call and throw out
377 * what does not fit. This means that the following does not work:
378 * dd if=/dbg/usbmon/0t bs=10
379 * Also, we do not allow seeks and do not bother advancing the offset.
380 */
381static ssize_t mon_text_read_t(struct file *file, char __user *buf,
382 size_t nbytes, loff_t *ppos)
383{
384 struct mon_reader_text *rp = file->private_data;
385 struct mon_event_text *ep;
386 struct mon_text_ptr ptr;
387
388 if (IS_ERR(ep = mon_text_read_wait(rp, file)))
389 return PTR_ERR(ep);
390 mutex_lock(&rp->printf_lock);
391 ptr.cnt = 0;
392 ptr.pbuf = rp->printf_buf;
393 ptr.limit = rp->printf_size;
394
395 mon_text_read_head_t(rp, &ptr, ep);
396 mon_text_read_statset(rp, &ptr, ep);
397 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
398 " %d", ep->length);
399 mon_text_read_data(rp, &ptr, ep);
400
401 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
402 ptr.cnt = -EFAULT;
403 mutex_unlock(&rp->printf_lock);
404 kmem_cache_free(rp->e_slab, ep);
405 return ptr.cnt;
406}
407
408static ssize_t mon_text_read_u(struct file *file, char __user *buf,
409 size_t nbytes, loff_t *ppos)
410{
411 struct mon_reader_text *rp = file->private_data;
412 struct mon_event_text *ep;
413 struct mon_text_ptr ptr;
414
415 if (IS_ERR(ep = mon_text_read_wait(rp, file)))
416 return PTR_ERR(ep);
417 mutex_lock(&rp->printf_lock);
418 ptr.cnt = 0;
419 ptr.pbuf = rp->printf_buf;
420 ptr.limit = rp->printf_size;
421
422 mon_text_read_head_u(rp, &ptr, ep);
423 if (ep->type == 'E') {
424 mon_text_read_statset(rp, &ptr, ep);
425 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
426 mon_text_read_isostat(rp, &ptr, ep);
427 mon_text_read_isodesc(rp, &ptr, ep);
428 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
429 mon_text_read_intstat(rp, &ptr, ep);
430 } else {
431 mon_text_read_statset(rp, &ptr, ep);
432 }
433 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
434 " %d", ep->length);
435 mon_text_read_data(rp, &ptr, ep);
436
437 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
438 ptr.cnt = -EFAULT;
439 mutex_unlock(&rp->printf_lock);
440 kmem_cache_free(rp->e_slab, ep);
441 return ptr.cnt;
442}
443
444static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
445 struct file *file)
446{
447 struct mon_bus *mbus = rp->r.m_bus;
448 DECLARE_WAITQUEUE(waita, current);
449 struct mon_event_text *ep;
450
451 add_wait_queue(&rp->wait, &waita);
452 set_current_state(TASK_INTERRUPTIBLE);
453 while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
454 if (file->f_flags & O_NONBLOCK) {
455 set_current_state(TASK_RUNNING);
456 remove_wait_queue(&rp->wait, &waita);
457 return ERR_PTR(-EWOULDBLOCK);
458 }
459 /*
460 * We do not count nwaiters, because ->release is supposed
461 * to be called when all openers are gone only.
462 */
463 schedule();
464 if (signal_pending(current)) {
465 remove_wait_queue(&rp->wait, &waita);
466 return ERR_PTR(-EINTR);
467 }
468 set_current_state(TASK_INTERRUPTIBLE);
469 }
470 set_current_state(TASK_RUNNING);
471 remove_wait_queue(&rp->wait, &waita);
472 return ep;
473}
474
475static void mon_text_read_head_t(struct mon_reader_text *rp,
476 struct mon_text_ptr *p, const struct mon_event_text *ep)
477{
478 char udir, utype;
479
480 udir = (ep->is_in ? 'i' : 'o');
481 switch (ep->xfertype) {
482 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
483 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
484 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
485 default: /* PIPE_BULK */ utype = 'B';
486 }
487 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
488 "%lx %u %c %c%c:%03u:%02u",
489 ep->id, ep->tstamp, ep->type,
490 utype, udir, ep->devnum, ep->epnum);
491}
492
493static void mon_text_read_head_u(struct mon_reader_text *rp,
494 struct mon_text_ptr *p, const struct mon_event_text *ep)
495{
496 char udir, utype;
497
498 udir = (ep->is_in ? 'i' : 'o');
499 switch (ep->xfertype) {
500 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
501 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
502 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
503 default: /* PIPE_BULK */ utype = 'B';
504 }
505 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
506 "%lx %u %c %c%c:%d:%03u:%u",
507 ep->id, ep->tstamp, ep->type,
508 utype, udir, ep->busnum, ep->devnum, ep->epnum);
509}
510
511static void mon_text_read_statset(struct mon_reader_text *rp,
512 struct mon_text_ptr *p, const struct mon_event_text *ep)
513{
514
515 if (ep->setup_flag == 0) { /* Setup packet is present and captured */
516 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
517 " s %02x %02x %04x %04x %04x",
518 ep->setup[0],
519 ep->setup[1],
520 (ep->setup[3] << 8) | ep->setup[2],
521 (ep->setup[5] << 8) | ep->setup[4],
522 (ep->setup[7] << 8) | ep->setup[6]);
523 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
524 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
525 " %c __ __ ____ ____ ____", ep->setup_flag);
526 } else { /* No setup for this kind of URB */
527 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
528 " %d", ep->status);
529 }
530}
531
532static void mon_text_read_intstat(struct mon_reader_text *rp,
533 struct mon_text_ptr *p, const struct mon_event_text *ep)
534{
535 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
536 " %d:%d", ep->status, ep->interval);
537}
538
539static void mon_text_read_isostat(struct mon_reader_text *rp,
540 struct mon_text_ptr *p, const struct mon_event_text *ep)
541{
542 if (ep->type == 'S') {
543 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
544 " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
545 } else {
546 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
547 " %d:%d:%d:%d",
548 ep->status, ep->interval, ep->start_frame, ep->error_count);
549 }
550}
551
552static void mon_text_read_isodesc(struct mon_reader_text *rp,
553 struct mon_text_ptr *p, const struct mon_event_text *ep)
554{
555 int ndesc; /* Display this many */
556 int i;
557 const struct mon_iso_desc *dp;
558
559 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
560 " %d", ep->numdesc);
561 ndesc = ep->numdesc;
562 if (ndesc > ISODESC_MAX)
563 ndesc = ISODESC_MAX;
564 if (ndesc < 0)
565 ndesc = 0;
566 dp = ep->isodesc;
567 for (i = 0; i < ndesc; i++) {
568 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
569 " %d:%u:%u", dp->status, dp->offset, dp->length);
570 dp++;
571 }
572}
573
574static void mon_text_read_data(struct mon_reader_text *rp,
575 struct mon_text_ptr *p, const struct mon_event_text *ep)
576{
577 int data_len, i;
578
579 if ((data_len = ep->length) > 0) {
580 if (ep->data_flag == 0) {
581 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
582 " =");
583 if (data_len >= DATA_MAX)
584 data_len = DATA_MAX;
585 for (i = 0; i < data_len; i++) {
586 if (i % 4 == 0) {
587 p->cnt += snprintf(p->pbuf + p->cnt,
588 p->limit - p->cnt,
589 " ");
590 }
591 p->cnt += snprintf(p->pbuf + p->cnt,
592 p->limit - p->cnt,
593 "%02x", ep->data[i]);
594 }
595 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
596 "\n");
597 } else {
598 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
599 " %c\n", ep->data_flag);
600 }
601 } else {
602 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n");
603 }
604}
605
606static int mon_text_release(struct inode *inode, struct file *file)
607{
608 struct mon_reader_text *rp = file->private_data;
609 struct mon_bus *mbus;
610 /* unsigned long flags; */
611 struct list_head *p;
612 struct mon_event_text *ep;
613
614 mutex_lock(&mon_lock);
615 mbus = inode->i_private;
616
617 if (mbus->nreaders <= 0) {
618 printk(KERN_ERR TAG ": consistency error on close\n");
619 mutex_unlock(&mon_lock);
620 return 0;
621 }
622 mon_reader_del(mbus, &rp->r);
623
624 /*
625 * In theory, e_list is protected by mbus->lock. However,
626 * after mon_reader_del has finished, the following is the case:
627 * - we are not on reader list anymore, so new events won't be added;
628 * - whole mbus may be dropped if it was orphaned.
629 * So, we better not touch mbus.
630 */
631 /* spin_lock_irqsave(&mbus->lock, flags); */
632 while (!list_empty(&rp->e_list)) {
633 p = rp->e_list.next;
634 ep = list_entry(p, struct mon_event_text, e_link);
635 list_del(p);
636 --rp->nevents;
637 kmem_cache_free(rp->e_slab, ep);
638 }
639 /* spin_unlock_irqrestore(&mbus->lock, flags); */
640
641 kmem_cache_destroy(rp->e_slab);
642 kfree(rp->printf_buf);
643 kfree(rp);
644
645 mutex_unlock(&mon_lock);
646 return 0;
647}
648
649static const struct file_operations mon_fops_text_t = {
650 .owner = THIS_MODULE,
651 .open = mon_text_open,
652 .llseek = no_llseek,
653 .read = mon_text_read_t,
654 .release = mon_text_release,
655};
656
657static const struct file_operations mon_fops_text_u = {
658 .owner = THIS_MODULE,
659 .open = mon_text_open,
660 .llseek = no_llseek,
661 .read = mon_text_read_u,
662 .release = mon_text_release,
663};
664
665int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
666{
667 struct dentry *d;
668 enum { NAMESZ = 10 };
669 char name[NAMESZ];
670 int busnum = ubus? ubus->busnum: 0;
671 int rc;
672
673 if (mon_dir == NULL)
674 return 0;
675
676 if (ubus != NULL) {
677 rc = snprintf(name, NAMESZ, "%dt", busnum);
678 if (rc <= 0 || rc >= NAMESZ)
679 goto err_print_t;
680 d = debugfs_create_file(name, 0600, mon_dir, mbus,
681 &mon_fops_text_t);
682 if (d == NULL)
683 goto err_create_t;
684 mbus->dent_t = d;
685 }
686
687 rc = snprintf(name, NAMESZ, "%du", busnum);
688 if (rc <= 0 || rc >= NAMESZ)
689 goto err_print_u;
690 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
691 if (d == NULL)
692 goto err_create_u;
693 mbus->dent_u = d;
694
695 rc = snprintf(name, NAMESZ, "%ds", busnum);
696 if (rc <= 0 || rc >= NAMESZ)
697 goto err_print_s;
698 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat);
699 if (d == NULL)
700 goto err_create_s;
701 mbus->dent_s = d;
702
703 return 1;
704
705err_create_s:
706err_print_s:
707 debugfs_remove(mbus->dent_u);
708 mbus->dent_u = NULL;
709err_create_u:
710err_print_u:
711 if (ubus != NULL) {
712 debugfs_remove(mbus->dent_t);
713 mbus->dent_t = NULL;
714 }
715err_create_t:
716err_print_t:
717 return 0;
718}
719
720void mon_text_del(struct mon_bus *mbus)
721{
722 debugfs_remove(mbus->dent_u);
723 if (mbus->dent_t != NULL)
724 debugfs_remove(mbus->dent_t);
725 debugfs_remove(mbus->dent_s);
726}
727
728/*
729 * Slab interface: constructor.
730 */
731static void mon_text_ctor(void *mem)
732{
733 /*
734 * Nothing to initialize. No, really!
735 * So, we fill it with garbage to emulate a reused object.
736 */
737 memset(mem, 0xe5, sizeof(struct mon_event_text));
738}
739
740int __init mon_text_init(void)
741{
742 struct dentry *mondir;
743
744 mondir = debugfs_create_dir("usbmon", usb_debug_root);
745 if (IS_ERR(mondir)) {
746 /* debugfs not available, but we can use usbmon without it */
747 return 0;
748 }
749 if (mondir == NULL) {
750 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n");
751 return -ENOMEM;
752 }
753 mon_dir = mondir;
754 return 0;
755}
756
757void mon_text_exit(void)
758{
759 debugfs_remove(mon_dir);
760}
1/*
2 * The USB Monitor, inspired by Dave Harding's USBMon.
3 *
4 * This is a text format reader.
5 */
6
7#include <linux/kernel.h>
8#include <linux/list.h>
9#include <linux/usb.h>
10#include <linux/slab.h>
11#include <linux/time.h>
12#include <linux/export.h>
13#include <linux/mutex.h>
14#include <linux/debugfs.h>
15#include <linux/scatterlist.h>
16#include <asm/uaccess.h>
17
18#include "usb_mon.h"
19
20/*
21 * No, we do not want arbitrarily long data strings.
22 * Use the binary interface if you want to capture bulk data!
23 */
24#define DATA_MAX 32
25
26/*
27 * Defined by USB 2.0 clause 9.3, table 9.2.
28 */
29#define SETUP_MAX 8
30
31/*
32 * This limit exists to prevent OOMs when the user process stops reading.
33 * If usbmon were available to unprivileged processes, it might be open
34 * to a local DoS. But we have to keep to root in order to prevent
35 * password sniffing from HID devices.
36 */
37#define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text))
38
39/*
40 * Potentially unlimited number; we limit it for similar allocations.
41 * The usbfs limits this to 128, but we're not quite as generous.
42 */
43#define ISODESC_MAX 5
44
45#define PRINTF_DFL 250 /* with 5 ISOs segs */
46
47struct mon_iso_desc {
48 int status;
49 unsigned int offset;
50 unsigned int length; /* Unsigned here, signed in URB. Historic. */
51};
52
53struct mon_event_text {
54 struct list_head e_link;
55 int type; /* submit, complete, etc. */
56 unsigned long id; /* From pointer, most of the time */
57 unsigned int tstamp;
58 int busnum;
59 char devnum;
60 char epnum;
61 char is_in;
62 char xfertype;
63 int length; /* Depends on type: xfer length or act length */
64 int status;
65 int interval;
66 int start_frame;
67 int error_count;
68 char setup_flag;
69 char data_flag;
70 int numdesc; /* Full number */
71 struct mon_iso_desc isodesc[ISODESC_MAX];
72 unsigned char setup[SETUP_MAX];
73 unsigned char data[DATA_MAX];
74};
75
76#define SLAB_NAME_SZ 30
77struct mon_reader_text {
78 struct kmem_cache *e_slab;
79 int nevents;
80 struct list_head e_list;
81 struct mon_reader r; /* In C, parent class can be placed anywhere */
82
83 wait_queue_head_t wait;
84 int printf_size;
85 char *printf_buf;
86 struct mutex printf_lock;
87
88 char slab_name[SLAB_NAME_SZ];
89};
90
91static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */
92
93static void mon_text_ctor(void *);
94
95struct mon_text_ptr {
96 int cnt, limit;
97 char *pbuf;
98};
99
100static struct mon_event_text *
101 mon_text_read_wait(struct mon_reader_text *rp, struct file *file);
102static void mon_text_read_head_t(struct mon_reader_text *rp,
103 struct mon_text_ptr *p, const struct mon_event_text *ep);
104static void mon_text_read_head_u(struct mon_reader_text *rp,
105 struct mon_text_ptr *p, const struct mon_event_text *ep);
106static void mon_text_read_statset(struct mon_reader_text *rp,
107 struct mon_text_ptr *p, const struct mon_event_text *ep);
108static void mon_text_read_intstat(struct mon_reader_text *rp,
109 struct mon_text_ptr *p, const struct mon_event_text *ep);
110static void mon_text_read_isostat(struct mon_reader_text *rp,
111 struct mon_text_ptr *p, const struct mon_event_text *ep);
112static void mon_text_read_isodesc(struct mon_reader_text *rp,
113 struct mon_text_ptr *p, const struct mon_event_text *ep);
114static void mon_text_read_data(struct mon_reader_text *rp,
115 struct mon_text_ptr *p, const struct mon_event_text *ep);
116
117/*
118 * mon_text_submit
119 * mon_text_complete
120 *
121 * May be called from an interrupt.
122 *
123 * This is called with the whole mon_bus locked, so no additional lock.
124 */
125
126static inline char mon_text_get_setup(struct mon_event_text *ep,
127 struct urb *urb, char ev_type, struct mon_bus *mbus)
128{
129
130 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S')
131 return '-';
132
133 if (urb->setup_packet == NULL)
134 return 'Z'; /* '0' would be not as pretty. */
135
136 memcpy(ep->setup, urb->setup_packet, SETUP_MAX);
137 return 0;
138}
139
140static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
141 int len, char ev_type, struct mon_bus *mbus)
142{
143 void *src;
144
145 if (len <= 0)
146 return 'L';
147 if (len >= DATA_MAX)
148 len = DATA_MAX;
149
150 if (ep->is_in) {
151 if (ev_type != 'C')
152 return '<';
153 } else {
154 if (ev_type != 'S')
155 return '>';
156 }
157
158 if (urb->num_sgs == 0) {
159 src = urb->transfer_buffer;
160 if (src == NULL)
161 return 'Z'; /* '0' would be not as pretty. */
162 } else {
163 struct scatterlist *sg = urb->sg;
164
165 if (PageHighMem(sg_page(sg)))
166 return 'D';
167
168 /* For the text interface we copy only the first sg buffer */
169 len = min_t(int, sg->length, len);
170 src = sg_virt(sg);
171 }
172
173 memcpy(ep->data, src, len);
174 return 0;
175}
176
177static inline unsigned int mon_get_timestamp(void)
178{
179 struct timeval tval;
180 unsigned int stamp;
181
182 do_gettimeofday(&tval);
183 stamp = tval.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */
184 stamp = stamp * 1000000 + tval.tv_usec;
185 return stamp;
186}
187
188static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
189 char ev_type, int status)
190{
191 struct mon_event_text *ep;
192 unsigned int stamp;
193 struct usb_iso_packet_descriptor *fp;
194 struct mon_iso_desc *dp;
195 int i, ndesc;
196
197 stamp = mon_get_timestamp();
198
199 if (rp->nevents >= EVENT_MAX ||
200 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
201 rp->r.m_bus->cnt_text_lost++;
202 return;
203 }
204
205 ep->type = ev_type;
206 ep->id = (unsigned long) urb;
207 ep->busnum = urb->dev->bus->busnum;
208 ep->devnum = urb->dev->devnum;
209 ep->epnum = usb_endpoint_num(&urb->ep->desc);
210 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
211 ep->is_in = usb_urb_dir_in(urb);
212 ep->tstamp = stamp;
213 ep->length = (ev_type == 'S') ?
214 urb->transfer_buffer_length : urb->actual_length;
215 /* Collecting status makes debugging sense for submits, too */
216 ep->status = status;
217
218 if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
219 ep->interval = urb->interval;
220 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
221 ep->interval = urb->interval;
222 ep->start_frame = urb->start_frame;
223 ep->error_count = urb->error_count;
224 }
225 ep->numdesc = urb->number_of_packets;
226 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC &&
227 urb->number_of_packets > 0) {
228 if ((ndesc = urb->number_of_packets) > ISODESC_MAX)
229 ndesc = ISODESC_MAX;
230 fp = urb->iso_frame_desc;
231 dp = ep->isodesc;
232 for (i = 0; i < ndesc; i++) {
233 dp->status = fp->status;
234 dp->offset = fp->offset;
235 dp->length = (ev_type == 'S') ?
236 fp->length : fp->actual_length;
237 fp++;
238 dp++;
239 }
240 /* Wasteful, but simple to understand: ISO 'C' is sparse. */
241 if (ev_type == 'C')
242 ep->length = urb->transfer_buffer_length;
243 }
244
245 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus);
246 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type,
247 rp->r.m_bus);
248
249 rp->nevents++;
250 list_add_tail(&ep->e_link, &rp->e_list);
251 wake_up(&rp->wait);
252}
253
254static void mon_text_submit(void *data, struct urb *urb)
255{
256 struct mon_reader_text *rp = data;
257 mon_text_event(rp, urb, 'S', -EINPROGRESS);
258}
259
260static void mon_text_complete(void *data, struct urb *urb, int status)
261{
262 struct mon_reader_text *rp = data;
263 mon_text_event(rp, urb, 'C', status);
264}
265
266static void mon_text_error(void *data, struct urb *urb, int error)
267{
268 struct mon_reader_text *rp = data;
269 struct mon_event_text *ep;
270
271 if (rp->nevents >= EVENT_MAX ||
272 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
273 rp->r.m_bus->cnt_text_lost++;
274 return;
275 }
276
277 ep->type = 'E';
278 ep->id = (unsigned long) urb;
279 ep->busnum = urb->dev->bus->busnum;
280 ep->devnum = urb->dev->devnum;
281 ep->epnum = usb_endpoint_num(&urb->ep->desc);
282 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
283 ep->is_in = usb_urb_dir_in(urb);
284 ep->tstamp = mon_get_timestamp();
285 ep->length = 0;
286 ep->status = error;
287
288 ep->setup_flag = '-';
289 ep->data_flag = 'E';
290
291 rp->nevents++;
292 list_add_tail(&ep->e_link, &rp->e_list);
293 wake_up(&rp->wait);
294}
295
296/*
297 * Fetch next event from the circular buffer.
298 */
299static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp,
300 struct mon_bus *mbus)
301{
302 struct list_head *p;
303 unsigned long flags;
304
305 spin_lock_irqsave(&mbus->lock, flags);
306 if (list_empty(&rp->e_list)) {
307 spin_unlock_irqrestore(&mbus->lock, flags);
308 return NULL;
309 }
310 p = rp->e_list.next;
311 list_del(p);
312 --rp->nevents;
313 spin_unlock_irqrestore(&mbus->lock, flags);
314 return list_entry(p, struct mon_event_text, e_link);
315}
316
317/*
318 */
319static int mon_text_open(struct inode *inode, struct file *file)
320{
321 struct mon_bus *mbus;
322 struct mon_reader_text *rp;
323 int rc;
324
325 mutex_lock(&mon_lock);
326 mbus = inode->i_private;
327
328 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
329 if (rp == NULL) {
330 rc = -ENOMEM;
331 goto err_alloc;
332 }
333 INIT_LIST_HEAD(&rp->e_list);
334 init_waitqueue_head(&rp->wait);
335 mutex_init(&rp->printf_lock);
336
337 rp->printf_size = PRINTF_DFL;
338 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL);
339 if (rp->printf_buf == NULL) {
340 rc = -ENOMEM;
341 goto err_alloc_pr;
342 }
343
344 rp->r.m_bus = mbus;
345 rp->r.r_data = rp;
346 rp->r.rnf_submit = mon_text_submit;
347 rp->r.rnf_error = mon_text_error;
348 rp->r.rnf_complete = mon_text_complete;
349
350 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp);
351 rp->e_slab = kmem_cache_create(rp->slab_name,
352 sizeof(struct mon_event_text), sizeof(long), 0,
353 mon_text_ctor);
354 if (rp->e_slab == NULL) {
355 rc = -ENOMEM;
356 goto err_slab;
357 }
358
359 mon_reader_add(mbus, &rp->r);
360
361 file->private_data = rp;
362 mutex_unlock(&mon_lock);
363 return 0;
364
365// err_busy:
366// kmem_cache_destroy(rp->e_slab);
367err_slab:
368 kfree(rp->printf_buf);
369err_alloc_pr:
370 kfree(rp);
371err_alloc:
372 mutex_unlock(&mon_lock);
373 return rc;
374}
375
376/*
377 * For simplicity, we read one record in one system call and throw out
378 * what does not fit. This means that the following does not work:
379 * dd if=/dbg/usbmon/0t bs=10
380 * Also, we do not allow seeks and do not bother advancing the offset.
381 */
382static ssize_t mon_text_read_t(struct file *file, char __user *buf,
383 size_t nbytes, loff_t *ppos)
384{
385 struct mon_reader_text *rp = file->private_data;
386 struct mon_event_text *ep;
387 struct mon_text_ptr ptr;
388
389 if (IS_ERR(ep = mon_text_read_wait(rp, file)))
390 return PTR_ERR(ep);
391 mutex_lock(&rp->printf_lock);
392 ptr.cnt = 0;
393 ptr.pbuf = rp->printf_buf;
394 ptr.limit = rp->printf_size;
395
396 mon_text_read_head_t(rp, &ptr, ep);
397 mon_text_read_statset(rp, &ptr, ep);
398 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
399 " %d", ep->length);
400 mon_text_read_data(rp, &ptr, ep);
401
402 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
403 ptr.cnt = -EFAULT;
404 mutex_unlock(&rp->printf_lock);
405 kmem_cache_free(rp->e_slab, ep);
406 return ptr.cnt;
407}
408
409static ssize_t mon_text_read_u(struct file *file, char __user *buf,
410 size_t nbytes, loff_t *ppos)
411{
412 struct mon_reader_text *rp = file->private_data;
413 struct mon_event_text *ep;
414 struct mon_text_ptr ptr;
415
416 if (IS_ERR(ep = mon_text_read_wait(rp, file)))
417 return PTR_ERR(ep);
418 mutex_lock(&rp->printf_lock);
419 ptr.cnt = 0;
420 ptr.pbuf = rp->printf_buf;
421 ptr.limit = rp->printf_size;
422
423 mon_text_read_head_u(rp, &ptr, ep);
424 if (ep->type == 'E') {
425 mon_text_read_statset(rp, &ptr, ep);
426 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
427 mon_text_read_isostat(rp, &ptr, ep);
428 mon_text_read_isodesc(rp, &ptr, ep);
429 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
430 mon_text_read_intstat(rp, &ptr, ep);
431 } else {
432 mon_text_read_statset(rp, &ptr, ep);
433 }
434 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
435 " %d", ep->length);
436 mon_text_read_data(rp, &ptr, ep);
437
438 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
439 ptr.cnt = -EFAULT;
440 mutex_unlock(&rp->printf_lock);
441 kmem_cache_free(rp->e_slab, ep);
442 return ptr.cnt;
443}
444
445static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
446 struct file *file)
447{
448 struct mon_bus *mbus = rp->r.m_bus;
449 DECLARE_WAITQUEUE(waita, current);
450 struct mon_event_text *ep;
451
452 add_wait_queue(&rp->wait, &waita);
453 set_current_state(TASK_INTERRUPTIBLE);
454 while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
455 if (file->f_flags & O_NONBLOCK) {
456 set_current_state(TASK_RUNNING);
457 remove_wait_queue(&rp->wait, &waita);
458 return ERR_PTR(-EWOULDBLOCK);
459 }
460 /*
461 * We do not count nwaiters, because ->release is supposed
462 * to be called when all openers are gone only.
463 */
464 schedule();
465 if (signal_pending(current)) {
466 remove_wait_queue(&rp->wait, &waita);
467 return ERR_PTR(-EINTR);
468 }
469 set_current_state(TASK_INTERRUPTIBLE);
470 }
471 set_current_state(TASK_RUNNING);
472 remove_wait_queue(&rp->wait, &waita);
473 return ep;
474}
475
476static void mon_text_read_head_t(struct mon_reader_text *rp,
477 struct mon_text_ptr *p, const struct mon_event_text *ep)
478{
479 char udir, utype;
480
481 udir = (ep->is_in ? 'i' : 'o');
482 switch (ep->xfertype) {
483 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
484 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
485 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
486 default: /* PIPE_BULK */ utype = 'B';
487 }
488 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
489 "%lx %u %c %c%c:%03u:%02u",
490 ep->id, ep->tstamp, ep->type,
491 utype, udir, ep->devnum, ep->epnum);
492}
493
494static void mon_text_read_head_u(struct mon_reader_text *rp,
495 struct mon_text_ptr *p, const struct mon_event_text *ep)
496{
497 char udir, utype;
498
499 udir = (ep->is_in ? 'i' : 'o');
500 switch (ep->xfertype) {
501 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
502 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
503 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
504 default: /* PIPE_BULK */ utype = 'B';
505 }
506 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
507 "%lx %u %c %c%c:%d:%03u:%u",
508 ep->id, ep->tstamp, ep->type,
509 utype, udir, ep->busnum, ep->devnum, ep->epnum);
510}
511
512static void mon_text_read_statset(struct mon_reader_text *rp,
513 struct mon_text_ptr *p, const struct mon_event_text *ep)
514{
515
516 if (ep->setup_flag == 0) { /* Setup packet is present and captured */
517 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
518 " s %02x %02x %04x %04x %04x",
519 ep->setup[0],
520 ep->setup[1],
521 (ep->setup[3] << 8) | ep->setup[2],
522 (ep->setup[5] << 8) | ep->setup[4],
523 (ep->setup[7] << 8) | ep->setup[6]);
524 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
525 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
526 " %c __ __ ____ ____ ____", ep->setup_flag);
527 } else { /* No setup for this kind of URB */
528 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
529 " %d", ep->status);
530 }
531}
532
533static void mon_text_read_intstat(struct mon_reader_text *rp,
534 struct mon_text_ptr *p, const struct mon_event_text *ep)
535{
536 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
537 " %d:%d", ep->status, ep->interval);
538}
539
540static void mon_text_read_isostat(struct mon_reader_text *rp,
541 struct mon_text_ptr *p, const struct mon_event_text *ep)
542{
543 if (ep->type == 'S') {
544 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
545 " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
546 } else {
547 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
548 " %d:%d:%d:%d",
549 ep->status, ep->interval, ep->start_frame, ep->error_count);
550 }
551}
552
553static void mon_text_read_isodesc(struct mon_reader_text *rp,
554 struct mon_text_ptr *p, const struct mon_event_text *ep)
555{
556 int ndesc; /* Display this many */
557 int i;
558 const struct mon_iso_desc *dp;
559
560 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
561 " %d", ep->numdesc);
562 ndesc = ep->numdesc;
563 if (ndesc > ISODESC_MAX)
564 ndesc = ISODESC_MAX;
565 if (ndesc < 0)
566 ndesc = 0;
567 dp = ep->isodesc;
568 for (i = 0; i < ndesc; i++) {
569 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
570 " %d:%u:%u", dp->status, dp->offset, dp->length);
571 dp++;
572 }
573}
574
575static void mon_text_read_data(struct mon_reader_text *rp,
576 struct mon_text_ptr *p, const struct mon_event_text *ep)
577{
578 int data_len, i;
579
580 if ((data_len = ep->length) > 0) {
581 if (ep->data_flag == 0) {
582 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
583 " =");
584 if (data_len >= DATA_MAX)
585 data_len = DATA_MAX;
586 for (i = 0; i < data_len; i++) {
587 if (i % 4 == 0) {
588 p->cnt += snprintf(p->pbuf + p->cnt,
589 p->limit - p->cnt,
590 " ");
591 }
592 p->cnt += snprintf(p->pbuf + p->cnt,
593 p->limit - p->cnt,
594 "%02x", ep->data[i]);
595 }
596 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
597 "\n");
598 } else {
599 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
600 " %c\n", ep->data_flag);
601 }
602 } else {
603 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n");
604 }
605}
606
607static int mon_text_release(struct inode *inode, struct file *file)
608{
609 struct mon_reader_text *rp = file->private_data;
610 struct mon_bus *mbus;
611 /* unsigned long flags; */
612 struct list_head *p;
613 struct mon_event_text *ep;
614
615 mutex_lock(&mon_lock);
616 mbus = inode->i_private;
617
618 if (mbus->nreaders <= 0) {
619 printk(KERN_ERR TAG ": consistency error on close\n");
620 mutex_unlock(&mon_lock);
621 return 0;
622 }
623 mon_reader_del(mbus, &rp->r);
624
625 /*
626 * In theory, e_list is protected by mbus->lock. However,
627 * after mon_reader_del has finished, the following is the case:
628 * - we are not on reader list anymore, so new events won't be added;
629 * - whole mbus may be dropped if it was orphaned.
630 * So, we better not touch mbus.
631 */
632 /* spin_lock_irqsave(&mbus->lock, flags); */
633 while (!list_empty(&rp->e_list)) {
634 p = rp->e_list.next;
635 ep = list_entry(p, struct mon_event_text, e_link);
636 list_del(p);
637 --rp->nevents;
638 kmem_cache_free(rp->e_slab, ep);
639 }
640 /* spin_unlock_irqrestore(&mbus->lock, flags); */
641
642 kmem_cache_destroy(rp->e_slab);
643 kfree(rp->printf_buf);
644 kfree(rp);
645
646 mutex_unlock(&mon_lock);
647 return 0;
648}
649
650static const struct file_operations mon_fops_text_t = {
651 .owner = THIS_MODULE,
652 .open = mon_text_open,
653 .llseek = no_llseek,
654 .read = mon_text_read_t,
655 .release = mon_text_release,
656};
657
658static const struct file_operations mon_fops_text_u = {
659 .owner = THIS_MODULE,
660 .open = mon_text_open,
661 .llseek = no_llseek,
662 .read = mon_text_read_u,
663 .release = mon_text_release,
664};
665
666int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
667{
668 struct dentry *d;
669 enum { NAMESZ = 10 };
670 char name[NAMESZ];
671 int busnum = ubus? ubus->busnum: 0;
672 int rc;
673
674 if (mon_dir == NULL)
675 return 0;
676
677 if (ubus != NULL) {
678 rc = snprintf(name, NAMESZ, "%dt", busnum);
679 if (rc <= 0 || rc >= NAMESZ)
680 goto err_print_t;
681 d = debugfs_create_file(name, 0600, mon_dir, mbus,
682 &mon_fops_text_t);
683 if (d == NULL)
684 goto err_create_t;
685 mbus->dent_t = d;
686 }
687
688 rc = snprintf(name, NAMESZ, "%du", busnum);
689 if (rc <= 0 || rc >= NAMESZ)
690 goto err_print_u;
691 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
692 if (d == NULL)
693 goto err_create_u;
694 mbus->dent_u = d;
695
696 rc = snprintf(name, NAMESZ, "%ds", busnum);
697 if (rc <= 0 || rc >= NAMESZ)
698 goto err_print_s;
699 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat);
700 if (d == NULL)
701 goto err_create_s;
702 mbus->dent_s = d;
703
704 return 1;
705
706err_create_s:
707err_print_s:
708 debugfs_remove(mbus->dent_u);
709 mbus->dent_u = NULL;
710err_create_u:
711err_print_u:
712 if (ubus != NULL) {
713 debugfs_remove(mbus->dent_t);
714 mbus->dent_t = NULL;
715 }
716err_create_t:
717err_print_t:
718 return 0;
719}
720
721void mon_text_del(struct mon_bus *mbus)
722{
723 debugfs_remove(mbus->dent_u);
724 if (mbus->dent_t != NULL)
725 debugfs_remove(mbus->dent_t);
726 debugfs_remove(mbus->dent_s);
727}
728
729/*
730 * Slab interface: constructor.
731 */
732static void mon_text_ctor(void *mem)
733{
734 /*
735 * Nothing to initialize. No, really!
736 * So, we fill it with garbage to emulate a reused object.
737 */
738 memset(mem, 0xe5, sizeof(struct mon_event_text));
739}
740
741int __init mon_text_init(void)
742{
743 struct dentry *mondir;
744
745 mondir = debugfs_create_dir("usbmon", usb_debug_root);
746 if (IS_ERR(mondir)) {
747 /* debugfs not available, but we can use usbmon without it */
748 return 0;
749 }
750 if (mondir == NULL) {
751 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n");
752 return -ENOMEM;
753 }
754 mon_dir = mondir;
755 return 0;
756}
757
758void mon_text_exit(void)
759{
760 debugfs_remove(mon_dir);
761}