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 46 struct mon_iso_desc { 47 int status; 48 unsigned int offset; 49 unsigned int length; /* Unsigned here, signed in URB. Historic. */ 50 }; 51 52 struct 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 76 struct 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 90 static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ 91 92 static void mon_text_ctor(void *); 93 94 struct mon_text_ptr { 95 int cnt, limit; 96 char *pbuf; 97 }; 98 99 static struct mon_event_text * 100 mon_text_read_wait(struct mon_reader_text *rp, struct file *file); 101 static void mon_text_read_head_t(struct mon_reader_text *rp, 102 struct mon_text_ptr *p, const struct mon_event_text *ep); 103 static void mon_text_read_head_u(struct mon_reader_text *rp, 104 struct mon_text_ptr *p, const struct mon_event_text *ep); 105 static void mon_text_read_statset(struct mon_reader_text *rp, 106 struct mon_text_ptr *p, const struct mon_event_text *ep); 107 static void mon_text_read_intstat(struct mon_reader_text *rp, 108 struct mon_text_ptr *p, const struct mon_event_text *ep); 109 static void mon_text_read_isostat(struct mon_reader_text *rp, 110 struct mon_text_ptr *p, const struct mon_event_text *ep); 111 static void mon_text_read_isodesc(struct mon_reader_text *rp, 112 struct mon_text_ptr *p, const struct mon_event_text *ep); 113 static 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 */ 124 125 static 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 } 138 139 static 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 } 175 176 static 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 } 186 187 static 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 } 252 253 static 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 } 258 259 static 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 } 264 265 static 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 */ 298 static 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 */ 318 static 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); 366 err_slab: 367 kfree(rp->printf_buf); 368 err_alloc_pr: 369 kfree(rp); 370 err_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 */ 381 static 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 } 407 408 static 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 } 443 444 static 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 } 474 475 static 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 } 492 493 static 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 } 510 511 static 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 } 531 532 static 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 } 538 539 static 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 } 551 552 static 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 } 573 574 static 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 } 605 606 static 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 } 648 649 static 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 }; 656 657 static 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 }; 664 665 int 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 (ubus != NULL) { 674 rc = snprintf(name, NAMESZ, "%dt", busnum); 675 if (rc <= 0 || rc >= NAMESZ) 676 goto err_print_t; 677 d = debugfs_create_file(name, 0600, mon_dir, mbus, 678 &mon_fops_text_t); 679 if (d == NULL) 680 goto err_create_t; 681 mbus->dent_t = d; 682 } 683 684 rc = snprintf(name, NAMESZ, "%du", busnum); 685 if (rc <= 0 || rc >= NAMESZ) 686 goto err_print_u; 687 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u); 688 if (d == NULL) 689 goto err_create_u; 690 mbus->dent_u = d; 691 692 rc = snprintf(name, NAMESZ, "%ds", busnum); 693 if (rc <= 0 || rc >= NAMESZ) 694 goto err_print_s; 695 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat); 696 if (d == NULL) 697 goto err_create_s; 698 mbus->dent_s = d; 699 700 return 1; 701 702 err_create_s: 703 err_print_s: 704 debugfs_remove(mbus->dent_u); 705 mbus->dent_u = NULL; 706 err_create_u: 707 err_print_u: 708 if (ubus != NULL) { 709 debugfs_remove(mbus->dent_t); 710 mbus->dent_t = NULL; 711 } 712 err_create_t: 713 err_print_t: 714 return 0; 715 } 716 717 void mon_text_del(struct mon_bus *mbus) 718 { 719 debugfs_remove(mbus->dent_u); 720 if (mbus->dent_t != NULL) 721 debugfs_remove(mbus->dent_t); 722 debugfs_remove(mbus->dent_s); 723 } 724 725 /* 726 * Slab interface: constructor. 727 */ 728 static void mon_text_ctor(void *mem) 729 { 730 /* 731 * Nothing to initialize. No, really! 732 * So, we fill it with garbage to emulate a reused object. 733 */ 734 memset(mem, 0xe5, sizeof(struct mon_event_text)); 735 } 736 737 int __init mon_text_init(void) 738 { 739 struct dentry *mondir; 740 741 mondir = debugfs_create_dir("usbmon", usb_debug_root); 742 if (IS_ERR(mondir)) { 743 printk(KERN_NOTICE TAG ": debugfs is not available\n"); 744 return -ENODEV; 745 } 746 if (mondir == NULL) { 747 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); 748 return -ENODEV; 749 } 750 mon_dir = mondir; 751 return 0; 752 } 753 754 void mon_text_exit(void) 755 { 756 debugfs_remove(mon_dir); 757 } 758