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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/ktime.h>
13#include <linux/export.h>
14#include <linux/mutex.h>
15#include <linux/debugfs.h>
16#include <linux/scatterlist.h>
17#include <linux/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}