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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/ktime.h>
13#include <linux/export.h>
14#include <linux/mutex.h>
15#include <linux/debugfs.h>
16#include <linux/scatterlist.h>
17#include <asm/uaccess.h>
18
19#include "usb_mon.h"
20
21/*
22 * No, we do not want arbitrarily long data strings.
23 * Use the binary interface if you want to capture bulk data!
24 */
25#define DATA_MAX 32
26
27/*
28 * Defined by USB 2.0 clause 9.3, table 9.2.
29 */
30#define SETUP_MAX 8
31
32/*
33 * This limit exists to prevent OOMs when the user process stops reading.
34 * If usbmon were available to unprivileged processes, it might be open
35 * to a local DoS. But we have to keep to root in order to prevent
36 * password sniffing from HID devices.
37 */
38#define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text))
39
40/*
41 * Potentially unlimited number; we limit it for similar allocations.
42 * The usbfs limits this to 128, but we're not quite as generous.
43 */
44#define ISODESC_MAX 5
45
46#define PRINTF_DFL 250 /* with 5 ISOs segs */
47
48struct mon_iso_desc {
49 int status;
50 unsigned int offset;
51 unsigned int length; /* Unsigned here, signed in URB. Historic. */
52};
53
54struct mon_event_text {
55 struct list_head e_link;
56 int type; /* submit, complete, etc. */
57 unsigned long id; /* From pointer, most of the time */
58 unsigned int tstamp;
59 int busnum;
60 char devnum;
61 char epnum;
62 char is_in;
63 char xfertype;
64 int length; /* Depends on type: xfer length or act length */
65 int status;
66 int interval;
67 int start_frame;
68 int error_count;
69 char setup_flag;
70 char data_flag;
71 int numdesc; /* Full number */
72 struct mon_iso_desc isodesc[ISODESC_MAX];
73 unsigned char setup[SETUP_MAX];
74 unsigned char data[DATA_MAX];
75};
76
77#define SLAB_NAME_SZ 30
78struct mon_reader_text {
79 struct kmem_cache *e_slab;
80 int nevents;
81 struct list_head e_list;
82 struct mon_reader r; /* In C, parent class can be placed anywhere */
83
84 wait_queue_head_t wait;
85 int printf_size;
86 char *printf_buf;
87 struct mutex printf_lock;
88
89 char slab_name[SLAB_NAME_SZ];
90};
91
92static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */
93
94static void mon_text_ctor(void *);
95
96struct mon_text_ptr {
97 int cnt, limit;
98 char *pbuf;
99};
100
101static struct mon_event_text *
102 mon_text_read_wait(struct mon_reader_text *rp, struct file *file);
103static void mon_text_read_head_t(struct mon_reader_text *rp,
104 struct mon_text_ptr *p, const struct mon_event_text *ep);
105static void mon_text_read_head_u(struct mon_reader_text *rp,
106 struct mon_text_ptr *p, const struct mon_event_text *ep);
107static void mon_text_read_statset(struct mon_reader_text *rp,
108 struct mon_text_ptr *p, const struct mon_event_text *ep);
109static void mon_text_read_intstat(struct mon_reader_text *rp,
110 struct mon_text_ptr *p, const struct mon_event_text *ep);
111static void mon_text_read_isostat(struct mon_reader_text *rp,
112 struct mon_text_ptr *p, const struct mon_event_text *ep);
113static void mon_text_read_isodesc(struct mon_reader_text *rp,
114 struct mon_text_ptr *p, const struct mon_event_text *ep);
115static void mon_text_read_data(struct mon_reader_text *rp,
116 struct mon_text_ptr *p, const struct mon_event_text *ep);
117
118/*
119 * mon_text_submit
120 * mon_text_complete
121 *
122 * May be called from an interrupt.
123 *
124 * This is called with the whole mon_bus locked, so no additional lock.
125 */
126
127static inline char mon_text_get_setup(struct mon_event_text *ep,
128 struct urb *urb, char ev_type, struct mon_bus *mbus)
129{
130
131 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S')
132 return '-';
133
134 if (urb->setup_packet == NULL)
135 return 'Z'; /* '0' would be not as pretty. */
136
137 memcpy(ep->setup, urb->setup_packet, SETUP_MAX);
138 return 0;
139}
140
141static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
142 int len, char ev_type, struct mon_bus *mbus)
143{
144 void *src;
145
146 if (len <= 0)
147 return 'L';
148 if (len >= DATA_MAX)
149 len = DATA_MAX;
150
151 if (ep->is_in) {
152 if (ev_type != 'C')
153 return '<';
154 } else {
155 if (ev_type != 'S')
156 return '>';
157 }
158
159 if (urb->num_sgs == 0) {
160 src = urb->transfer_buffer;
161 if (src == NULL)
162 return 'Z'; /* '0' would be not as pretty. */
163 } else {
164 struct scatterlist *sg = urb->sg;
165
166 if (PageHighMem(sg_page(sg)))
167 return 'D';
168
169 /* For the text interface we copy only the first sg buffer */
170 len = min_t(int, sg->length, len);
171 src = sg_virt(sg);
172 }
173
174 memcpy(ep->data, src, len);
175 return 0;
176}
177
178static inline unsigned int mon_get_timestamp(void)
179{
180 struct timespec64 now;
181 unsigned int stamp;
182
183 ktime_get_ts64(&now);
184 stamp = now.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */
185 stamp = stamp * USEC_PER_SEC + now.tv_nsec / NSEC_PER_USEC;
186 return stamp;
187}
188
189static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
190 char ev_type, int status)
191{
192 struct mon_event_text *ep;
193 unsigned int stamp;
194 struct usb_iso_packet_descriptor *fp;
195 struct mon_iso_desc *dp;
196 int i, ndesc;
197
198 stamp = mon_get_timestamp();
199
200 if (rp->nevents >= EVENT_MAX ||
201 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
202 rp->r.m_bus->cnt_text_lost++;
203 return;
204 }
205
206 ep->type = ev_type;
207 ep->id = (unsigned long) urb;
208 ep->busnum = urb->dev->bus->busnum;
209 ep->devnum = urb->dev->devnum;
210 ep->epnum = usb_endpoint_num(&urb->ep->desc);
211 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
212 ep->is_in = usb_urb_dir_in(urb);
213 ep->tstamp = stamp;
214 ep->length = (ev_type == 'S') ?
215 urb->transfer_buffer_length : urb->actual_length;
216 /* Collecting status makes debugging sense for submits, too */
217 ep->status = status;
218
219 if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
220 ep->interval = urb->interval;
221 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
222 ep->interval = urb->interval;
223 ep->start_frame = urb->start_frame;
224 ep->error_count = urb->error_count;
225 }
226 ep->numdesc = urb->number_of_packets;
227 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC &&
228 urb->number_of_packets > 0) {
229 if ((ndesc = urb->number_of_packets) > ISODESC_MAX)
230 ndesc = ISODESC_MAX;
231 fp = urb->iso_frame_desc;
232 dp = ep->isodesc;
233 for (i = 0; i < ndesc; i++) {
234 dp->status = fp->status;
235 dp->offset = fp->offset;
236 dp->length = (ev_type == 'S') ?
237 fp->length : fp->actual_length;
238 fp++;
239 dp++;
240 }
241 /* Wasteful, but simple to understand: ISO 'C' is sparse. */
242 if (ev_type == 'C')
243 ep->length = urb->transfer_buffer_length;
244 }
245
246 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus);
247 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type,
248 rp->r.m_bus);
249
250 rp->nevents++;
251 list_add_tail(&ep->e_link, &rp->e_list);
252 wake_up(&rp->wait);
253}
254
255static void mon_text_submit(void *data, struct urb *urb)
256{
257 struct mon_reader_text *rp = data;
258 mon_text_event(rp, urb, 'S', -EINPROGRESS);
259}
260
261static void mon_text_complete(void *data, struct urb *urb, int status)
262{
263 struct mon_reader_text *rp = data;
264 mon_text_event(rp, urb, 'C', status);
265}
266
267static void mon_text_error(void *data, struct urb *urb, int error)
268{
269 struct mon_reader_text *rp = data;
270 struct mon_event_text *ep;
271
272 if (rp->nevents >= EVENT_MAX ||
273 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) {
274 rp->r.m_bus->cnt_text_lost++;
275 return;
276 }
277
278 ep->type = 'E';
279 ep->id = (unsigned long) urb;
280 ep->busnum = urb->dev->bus->busnum;
281 ep->devnum = urb->dev->devnum;
282 ep->epnum = usb_endpoint_num(&urb->ep->desc);
283 ep->xfertype = usb_endpoint_type(&urb->ep->desc);
284 ep->is_in = usb_urb_dir_in(urb);
285 ep->tstamp = mon_get_timestamp();
286 ep->length = 0;
287 ep->status = error;
288
289 ep->setup_flag = '-';
290 ep->data_flag = 'E';
291
292 rp->nevents++;
293 list_add_tail(&ep->e_link, &rp->e_list);
294 wake_up(&rp->wait);
295}
296
297/*
298 * Fetch next event from the circular buffer.
299 */
300static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp,
301 struct mon_bus *mbus)
302{
303 struct list_head *p;
304 unsigned long flags;
305
306 spin_lock_irqsave(&mbus->lock, flags);
307 if (list_empty(&rp->e_list)) {
308 spin_unlock_irqrestore(&mbus->lock, flags);
309 return NULL;
310 }
311 p = rp->e_list.next;
312 list_del(p);
313 --rp->nevents;
314 spin_unlock_irqrestore(&mbus->lock, flags);
315 return list_entry(p, struct mon_event_text, e_link);
316}
317
318/*
319 */
320static int mon_text_open(struct inode *inode, struct file *file)
321{
322 struct mon_bus *mbus;
323 struct mon_reader_text *rp;
324 int rc;
325
326 mutex_lock(&mon_lock);
327 mbus = inode->i_private;
328
329 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
330 if (rp == NULL) {
331 rc = -ENOMEM;
332 goto err_alloc;
333 }
334 INIT_LIST_HEAD(&rp->e_list);
335 init_waitqueue_head(&rp->wait);
336 mutex_init(&rp->printf_lock);
337
338 rp->printf_size = PRINTF_DFL;
339 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL);
340 if (rp->printf_buf == NULL) {
341 rc = -ENOMEM;
342 goto err_alloc_pr;
343 }
344
345 rp->r.m_bus = mbus;
346 rp->r.r_data = rp;
347 rp->r.rnf_submit = mon_text_submit;
348 rp->r.rnf_error = mon_text_error;
349 rp->r.rnf_complete = mon_text_complete;
350
351 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp);
352 rp->e_slab = kmem_cache_create(rp->slab_name,
353 sizeof(struct mon_event_text), sizeof(long), 0,
354 mon_text_ctor);
355 if (rp->e_slab == NULL) {
356 rc = -ENOMEM;
357 goto err_slab;
358 }
359
360 mon_reader_add(mbus, &rp->r);
361
362 file->private_data = rp;
363 mutex_unlock(&mon_lock);
364 return 0;
365
366// err_busy:
367// kmem_cache_destroy(rp->e_slab);
368err_slab:
369 kfree(rp->printf_buf);
370err_alloc_pr:
371 kfree(rp);
372err_alloc:
373 mutex_unlock(&mon_lock);
374 return rc;
375}
376
377/*
378 * For simplicity, we read one record in one system call and throw out
379 * what does not fit. This means that the following does not work:
380 * dd if=/dbg/usbmon/0t bs=10
381 * Also, we do not allow seeks and do not bother advancing the offset.
382 */
383static ssize_t mon_text_read_t(struct file *file, char __user *buf,
384 size_t nbytes, loff_t *ppos)
385{
386 struct mon_reader_text *rp = file->private_data;
387 struct mon_event_text *ep;
388 struct mon_text_ptr ptr;
389
390 ep = mon_text_read_wait(rp, file);
391 if (IS_ERR(ep))
392 return PTR_ERR(ep);
393 mutex_lock(&rp->printf_lock);
394 ptr.cnt = 0;
395 ptr.pbuf = rp->printf_buf;
396 ptr.limit = rp->printf_size;
397
398 mon_text_read_head_t(rp, &ptr, ep);
399 mon_text_read_statset(rp, &ptr, ep);
400 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
401 " %d", ep->length);
402 mon_text_read_data(rp, &ptr, ep);
403
404 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
405 ptr.cnt = -EFAULT;
406 mutex_unlock(&rp->printf_lock);
407 kmem_cache_free(rp->e_slab, ep);
408 return ptr.cnt;
409}
410
411static ssize_t mon_text_read_u(struct file *file, char __user *buf,
412 size_t nbytes, loff_t *ppos)
413{
414 struct mon_reader_text *rp = file->private_data;
415 struct mon_event_text *ep;
416 struct mon_text_ptr ptr;
417
418 ep = mon_text_read_wait(rp, file);
419 if (IS_ERR(ep))
420 return PTR_ERR(ep);
421 mutex_lock(&rp->printf_lock);
422 ptr.cnt = 0;
423 ptr.pbuf = rp->printf_buf;
424 ptr.limit = rp->printf_size;
425
426 mon_text_read_head_u(rp, &ptr, ep);
427 if (ep->type == 'E') {
428 mon_text_read_statset(rp, &ptr, ep);
429 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) {
430 mon_text_read_isostat(rp, &ptr, ep);
431 mon_text_read_isodesc(rp, &ptr, ep);
432 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) {
433 mon_text_read_intstat(rp, &ptr, ep);
434 } else {
435 mon_text_read_statset(rp, &ptr, ep);
436 }
437 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
438 " %d", ep->length);
439 mon_text_read_data(rp, &ptr, ep);
440
441 if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
442 ptr.cnt = -EFAULT;
443 mutex_unlock(&rp->printf_lock);
444 kmem_cache_free(rp->e_slab, ep);
445 return ptr.cnt;
446}
447
448static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
449 struct file *file)
450{
451 struct mon_bus *mbus = rp->r.m_bus;
452 DECLARE_WAITQUEUE(waita, current);
453 struct mon_event_text *ep;
454
455 add_wait_queue(&rp->wait, &waita);
456 set_current_state(TASK_INTERRUPTIBLE);
457 while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
458 if (file->f_flags & O_NONBLOCK) {
459 set_current_state(TASK_RUNNING);
460 remove_wait_queue(&rp->wait, &waita);
461 return ERR_PTR(-EWOULDBLOCK);
462 }
463 /*
464 * We do not count nwaiters, because ->release is supposed
465 * to be called when all openers are gone only.
466 */
467 schedule();
468 if (signal_pending(current)) {
469 remove_wait_queue(&rp->wait, &waita);
470 return ERR_PTR(-EINTR);
471 }
472 set_current_state(TASK_INTERRUPTIBLE);
473 }
474 set_current_state(TASK_RUNNING);
475 remove_wait_queue(&rp->wait, &waita);
476 return ep;
477}
478
479static void mon_text_read_head_t(struct mon_reader_text *rp,
480 struct mon_text_ptr *p, const struct mon_event_text *ep)
481{
482 char udir, utype;
483
484 udir = (ep->is_in ? 'i' : 'o');
485 switch (ep->xfertype) {
486 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
487 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
488 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
489 default: /* PIPE_BULK */ utype = 'B';
490 }
491 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
492 "%lx %u %c %c%c:%03u:%02u",
493 ep->id, ep->tstamp, ep->type,
494 utype, udir, ep->devnum, ep->epnum);
495}
496
497static void mon_text_read_head_u(struct mon_reader_text *rp,
498 struct mon_text_ptr *p, const struct mon_event_text *ep)
499{
500 char udir, utype;
501
502 udir = (ep->is_in ? 'i' : 'o');
503 switch (ep->xfertype) {
504 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break;
505 case USB_ENDPOINT_XFER_INT: utype = 'I'; break;
506 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break;
507 default: /* PIPE_BULK */ utype = 'B';
508 }
509 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
510 "%lx %u %c %c%c:%d:%03u:%u",
511 ep->id, ep->tstamp, ep->type,
512 utype, udir, ep->busnum, ep->devnum, ep->epnum);
513}
514
515static void mon_text_read_statset(struct mon_reader_text *rp,
516 struct mon_text_ptr *p, const struct mon_event_text *ep)
517{
518
519 if (ep->setup_flag == 0) { /* Setup packet is present and captured */
520 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
521 " s %02x %02x %04x %04x %04x",
522 ep->setup[0],
523 ep->setup[1],
524 (ep->setup[3] << 8) | ep->setup[2],
525 (ep->setup[5] << 8) | ep->setup[4],
526 (ep->setup[7] << 8) | ep->setup[6]);
527 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
528 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
529 " %c __ __ ____ ____ ____", ep->setup_flag);
530 } else { /* No setup for this kind of URB */
531 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
532 " %d", ep->status);
533 }
534}
535
536static void mon_text_read_intstat(struct mon_reader_text *rp,
537 struct mon_text_ptr *p, const struct mon_event_text *ep)
538{
539 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
540 " %d:%d", ep->status, ep->interval);
541}
542
543static void mon_text_read_isostat(struct mon_reader_text *rp,
544 struct mon_text_ptr *p, const struct mon_event_text *ep)
545{
546 if (ep->type == 'S') {
547 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
548 " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
549 } else {
550 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
551 " %d:%d:%d:%d",
552 ep->status, ep->interval, ep->start_frame, ep->error_count);
553 }
554}
555
556static void mon_text_read_isodesc(struct mon_reader_text *rp,
557 struct mon_text_ptr *p, const struct mon_event_text *ep)
558{
559 int ndesc; /* Display this many */
560 int i;
561 const struct mon_iso_desc *dp;
562
563 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
564 " %d", ep->numdesc);
565 ndesc = ep->numdesc;
566 if (ndesc > ISODESC_MAX)
567 ndesc = ISODESC_MAX;
568 if (ndesc < 0)
569 ndesc = 0;
570 dp = ep->isodesc;
571 for (i = 0; i < ndesc; i++) {
572 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
573 " %d:%u:%u", dp->status, dp->offset, dp->length);
574 dp++;
575 }
576}
577
578static void mon_text_read_data(struct mon_reader_text *rp,
579 struct mon_text_ptr *p, const struct mon_event_text *ep)
580{
581 int data_len, i;
582
583 if ((data_len = ep->length) > 0) {
584 if (ep->data_flag == 0) {
585 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
586 " =");
587 if (data_len >= DATA_MAX)
588 data_len = DATA_MAX;
589 for (i = 0; i < data_len; i++) {
590 if (i % 4 == 0) {
591 p->cnt += snprintf(p->pbuf + p->cnt,
592 p->limit - p->cnt,
593 " ");
594 }
595 p->cnt += snprintf(p->pbuf + p->cnt,
596 p->limit - p->cnt,
597 "%02x", ep->data[i]);
598 }
599 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
600 "\n");
601 } else {
602 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
603 " %c\n", ep->data_flag);
604 }
605 } else {
606 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n");
607 }
608}
609
610static int mon_text_release(struct inode *inode, struct file *file)
611{
612 struct mon_reader_text *rp = file->private_data;
613 struct mon_bus *mbus;
614 /* unsigned long flags; */
615 struct list_head *p;
616 struct mon_event_text *ep;
617
618 mutex_lock(&mon_lock);
619 mbus = inode->i_private;
620
621 if (mbus->nreaders <= 0) {
622 printk(KERN_ERR TAG ": consistency error on close\n");
623 mutex_unlock(&mon_lock);
624 return 0;
625 }
626 mon_reader_del(mbus, &rp->r);
627
628 /*
629 * In theory, e_list is protected by mbus->lock. However,
630 * after mon_reader_del has finished, the following is the case:
631 * - we are not on reader list anymore, so new events won't be added;
632 * - whole mbus may be dropped if it was orphaned.
633 * So, we better not touch mbus.
634 */
635 /* spin_lock_irqsave(&mbus->lock, flags); */
636 while (!list_empty(&rp->e_list)) {
637 p = rp->e_list.next;
638 ep = list_entry(p, struct mon_event_text, e_link);
639 list_del(p);
640 --rp->nevents;
641 kmem_cache_free(rp->e_slab, ep);
642 }
643 /* spin_unlock_irqrestore(&mbus->lock, flags); */
644
645 kmem_cache_destroy(rp->e_slab);
646 kfree(rp->printf_buf);
647 kfree(rp);
648
649 mutex_unlock(&mon_lock);
650 return 0;
651}
652
653static const struct file_operations mon_fops_text_t = {
654 .owner = THIS_MODULE,
655 .open = mon_text_open,
656 .llseek = no_llseek,
657 .read = mon_text_read_t,
658 .release = mon_text_release,
659};
660
661static const struct file_operations mon_fops_text_u = {
662 .owner = THIS_MODULE,
663 .open = mon_text_open,
664 .llseek = no_llseek,
665 .read = mon_text_read_u,
666 .release = mon_text_release,
667};
668
669int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
670{
671 struct dentry *d;
672 enum { NAMESZ = 10 };
673 char name[NAMESZ];
674 int busnum = ubus? ubus->busnum: 0;
675 int rc;
676
677 if (mon_dir == NULL)
678 return 0;
679
680 if (ubus != NULL) {
681 rc = snprintf(name, NAMESZ, "%dt", busnum);
682 if (rc <= 0 || rc >= NAMESZ)
683 goto err_print_t;
684 d = debugfs_create_file(name, 0600, mon_dir, mbus,
685 &mon_fops_text_t);
686 if (d == NULL)
687 goto err_create_t;
688 mbus->dent_t = d;
689 }
690
691 rc = snprintf(name, NAMESZ, "%du", busnum);
692 if (rc <= 0 || rc >= NAMESZ)
693 goto err_print_u;
694 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
695 if (d == NULL)
696 goto err_create_u;
697 mbus->dent_u = d;
698
699 rc = snprintf(name, NAMESZ, "%ds", busnum);
700 if (rc <= 0 || rc >= NAMESZ)
701 goto err_print_s;
702 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat);
703 if (d == NULL)
704 goto err_create_s;
705 mbus->dent_s = d;
706
707 return 1;
708
709err_create_s:
710err_print_s:
711 debugfs_remove(mbus->dent_u);
712 mbus->dent_u = NULL;
713err_create_u:
714err_print_u:
715 if (ubus != NULL) {
716 debugfs_remove(mbus->dent_t);
717 mbus->dent_t = NULL;
718 }
719err_create_t:
720err_print_t:
721 return 0;
722}
723
724void mon_text_del(struct mon_bus *mbus)
725{
726 debugfs_remove(mbus->dent_u);
727 if (mbus->dent_t != NULL)
728 debugfs_remove(mbus->dent_t);
729 debugfs_remove(mbus->dent_s);
730}
731
732/*
733 * Slab interface: constructor.
734 */
735static void mon_text_ctor(void *mem)
736{
737 /*
738 * Nothing to initialize. No, really!
739 * So, we fill it with garbage to emulate a reused object.
740 */
741 memset(mem, 0xe5, sizeof(struct mon_event_text));
742}
743
744int __init mon_text_init(void)
745{
746 struct dentry *mondir;
747
748 mondir = debugfs_create_dir("usbmon", usb_debug_root);
749 if (IS_ERR(mondir)) {
750 /* debugfs not available, but we can use usbmon without it */
751 return 0;
752 }
753 if (mondir == NULL) {
754 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n");
755 return -ENOMEM;
756 }
757 mon_dir = mondir;
758 return 0;
759}
760
761void mon_text_exit(void)
762{
763 debugfs_remove(mon_dir);
764}
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}