Updated Kamvas Pro 19 descriptor check
This fixes #43 (closed) for me, works a treat, and should also still work for the older firmware with the smaller descriptor.
To duplicate some info in that issue for context:
It seems newer firmware has a hid descriptor that is 438 bytes long, not the 328 the check is looking for, I don't know how to dump the firmware version on linux, but I suspect because my units hardware is newer that it's running an updated firmware.
Comparing against the hid recording in #36 (closed), it seems the following has been added:
# 0x05, 0x01, // Usage Page (Generic Desktop) 328
# 0x09, 0x01, // Usage (Pointer) 330
# 0xa1, 0x01, // Collection (Application) 332
# 0x09, 0x01, // Usage (Pointer) 334
# 0xa1, 0x00, // Collection (Physical) 336
# 0x05, 0x09, // Usage Page (Button) 338
# 0x19, 0x01, // UsageMinimum (1) 340
# 0x29, 0x03, // UsageMaximum (3) 342
# 0x15, 0x00, // Logical Minimum (0) 344
# 0x25, 0x01, // Logical Maximum (1) 346
# ┅ 0x85, 0x02, // Report ID (2) 348
# 0x95, 0x03, // Report Count (3) 350
# 0x75, 0x01, // Report Size (1) 352
# ┇ 0x81, 0x02, // Input (Data,Var,Abs) 354
# 0x95, 0x01, // Report Count (1) 356
# 0x75, 0x05, // Report Size (5) 358
# ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 360
# 0x05, 0x01, // Usage Page (Generic Desktop) 362
# 0x09, 0x30, // Usage (X) 364
# 0x09, 0x31, // Usage (Y) 366
# 0x15, 0x81, // Logical Minimum (-127) 368
# 0x25, 0x7f, // Logical Maximum (127) 370
# 0x75, 0x08, // Report Size (8) 372
# 0x95, 0x02, // Report Count (2) 374
# ┇ 0x81, 0x06, // Input (Data,Var,Rel) 376
# 0x95, 0x04, // Report Count (4) 378
# 0x75, 0x08, // Report Size (8) 380
# ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 382
# 0xc0, // End Collection 384
# 0xc0, // End Collection 385
# 0x05, 0x0d, // Usage Page (Digitizers) 386
# 0x09, 0x05, // Usage (Touch Pad) 388
# 0xa1, 0x01, // Collection (Application) 390
# 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page FF00) 392
# 0x09, 0x0c, // Usage (Vendor Usage 0x0c) 395
# 0x15, 0x00, // Logical Minimum (0) 397
# 0x26, 0xff, 0x00, // Logical Maximum (255) 399
# 0x75, 0x08, // Report Size (8) 402
# 0x95, 0x10, // Report Count (16) 404
# ┅ 0x85, 0x3f, // Report ID (63) 406
# ┇ 0x81, 0x22, // Input (Data,Var,Abs,NoPref) 408
# 0xc0, // End Collection 410
# 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page FF00) 411
# 0x09, 0x0c, // Usage (Vendor Usage 0x0c) 414
# 0xa1, 0x01, // Collection (Application) 416
# 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page FF00) 418
# 0x09, 0x0c, // Usage (Vendor Usage 0x0c) 421
# 0x15, 0x00, // Logical Minimum (0) 423
# 0x26, 0xff, 0x00, // Logical Maximum (255) 425
# ┅ 0x85, 0x44, // Report ID (68) 428
# 0x75, 0x08, // Report Size (8) 430
# 0x96, 0x6b, 0x05, // Report Count (1387) 432
# ┇ 0x81, 0x00, // Input (Data,Arr,Abs) 435
# 0xc0, // End Collection 437This PR updates the descriptor check to look for both the 328 and the 438 length descriptors, I'm not 100% sure the proper way to cross the probe boundary into the bpf machinery with the info needed, so i'm just using a bool, extended_descriptor which is used to control the memcpy size to truncate the descriptor if it's not the extended variant.
Anynyan, let me know if this looks decent or not~
Closes #43 (closed)
edit by @whot: add closes tag