Hi Adam, On Sat, Mar 1, 2014 at 5:34 AM, Adam Warski <adam@xxxxxxxxxx> wrote: >> Can you save the raw dump using "hcidump -w output.dump" (or using >> btmon -w) and send to the list? It is easier to analyze, as the parser >> may be bogus. > > Sure. The problems start at 63.120548. > The dump is here: http://www.warski.org/btmon_ibeacons.dat Maybe you already did your own investigation, but here goes my findings: When opening the dump file on a hex editor, we can see that this first bogus packet starts (skipping BTSnoop's own header) at offset 0x45a4 (with bytes "3E 2A 02 01 ..."). At offset 0x45b4 we can see that the packet becomes truncated by missing these bytes (based on previous correct packets): 1A FF 4C 00 02 15 B9 40 7F 30 F5 F8 46 6E AF F9 >From now on, the packets become garbage because they are "shifted" due to these missing bytes. I think we can rule out any problems on the hcidump/btmon tools (as the raw logs come directly from the kernel), so I see two possibilities here: 1) There might be a bug in HCI packet reassembly logic (either in hci_core.c or btusb.c). 2) (most likely) your BT dongle may be broken (i.e. generating truncated USB packets from time to time) So my suggestion would be to try with a different dongle, preferably of a different chipset vendor. Note that "TP-Link" is just the brand name, you can confirm the chipset using lsusb or (even better) "hciconfig hci0 -a" (check "Manufacturer" field). Can you also provide the "lsusb" and "hciconfig hci0 -a" output (feel free to modify the BT address for privacy reasons)? I think it is important to have this archived so similar reports can be traced to this hardware and firmware. Another good source of information is the kernel debug logs. Collect it by enabling dynamic debugging: # dmesg -c # just to clear the kernel log buffer # echo 'module bluetooth +pf' | cat > /sys/kernel/debug/dynamic_debug/control # echo 'module btusb +pf' | cat > /sys/kernel/debug/dynamic_debug/control # btmon -w lescan.dump # So we can correlate the kernel log with the actual packets # hcitool lescan --duplicates # Run on another terminal, until packets become corrupt # dmesg > dmesg.txt # echo 'module bluetooth -pf' | cat > /sys/kernel/debug/dynamic_debug/control # echo 'module btusb -pf' | cat > /sys/kernel/debug/dynamic_debug/control # gzip dmesg.txt (if it is too big) Then send dmesg.txt.gz + lescan.dump to the list. You may want to mask out your BT address on the log as well. > > Thanks, > Adam Best Regards, -- Anderson Lizardo http://www.indt.org/?lang=en INdT - Manaus - Brazil -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
