Bluetooth

Bluetooth is a family of protocols that are popular for building wireless accessories. A common use for Bluetooth is for connecting mobile phone accessories, but other applications also exist, such as wireless mice and keyboards for computers; some of the applications for Bluetooth are:

  1. Handsfree headsets for mobile phones - for phone calls (not for music)
  2. A2DP Headsets - for good quality music (often have support for phone calls too)
  3. Carkit - multiprofiles device to be used in your car (various functionality, for example: phone calls, SMS/MMS/Email notifications…)
  4. Low Energy Devices - healthly, proximity…
  5. HID devices - mice, keyboards, gamepads…
  6. Network Access Point (aka tethering) - provide internet connection to device or to other device
  7. Serial port - there is a possibility to use RFCOMM profile to pass any type of data using bluetooth
  8. File sharing through OBEX - used in phones, tablets, computers

History

XXX - add a brief description of Bluetooth history

Protocol dependencies

  • HCI_H4: This is not a protocol but more an encapsulation format that wireshark implements.

At the lowest layer implemented in Wireshark, Bluetooth consists of 4 different types of frames:

Example traffic

No.     Time        Source                Destination           Protocol Info
     11 5.731294                                                L2CAP    Sent Echo Request

Frame 11 (57 bytes on wire, 57 bytes captured)
Bluetooth HCI H4 Sent ACL Data
    Direction: Sent (0x00)
    HCI Packet Type: ACL Data (0x02)
Bluetooth HCI ACL Packet
    .... 0000 0010 1001 = Connection Handle: 0x0029
    ..10 .... .... .... = PB Flag: Start Fragment (2)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 52
Bluetooth L2CAP Packet
    Length: 48
    CID: 0x0001
    Command: Echo Request
        Command Code: Echo Request (0x08)
        Command Identifier: 0xc8
        Command Length: 44

Wireshark

The Bluetooth stack is partially implemented and Wireshark can dissect several of the layers and protocols of the stack.

There is a libpcap format defined for Bluetooth frames, and support in libpcap 1.0.0 and later for capturing on Bluetooth devices in Linux; Wireshark, if linked with that version of libpcap, is able to capture on Bluetooth devices. (In Linux distributions that come with pre-1.0.0 versions of libpcap, libpcap doesn't support capturing on Bluetooth devices, so you would have to get libpcap 1.0.0 or later from tcpdump.org, install it, and build Wireshark with that version of libpcap in order to capture on Bluetooth devices. As of 2009-01-27, Gentoo Linux has libpcap with Bluetooth support in its mainline repository (portage).) Wireshark can also read captures in that format.

The original pcap format didn't store whether the packet was being sent or received (bug 1751). A newer file format includes the direction information as a 4-byte field where bit0 is set if the packet was 'received', see LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR at LINK-LAYER HEADER TYPES. Note that this field is big-endian even if the pcap file has been written in little-endian everywhere else (Development/LibpcapFileFormat). The original format uses protocol id LINKTYPE_BLUETOOTH_HCI_H4 and the new format uses LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR (LINK-LAYER HEADER TYPES).

In addition, Wireshark can read capture files created by the HCIDUMP utility that is available with the Linux and (I think) the BSD Bluetooth stack, and can also read capture files from the macOS PacketLogger Bluetooth logger application. Other platforms that can create capture files include the following. The .NET library 32feet.NET produces libpcap captures when using the Stonestreet One Bluetopia stack on Windows Mobile, see the Diagnostics section in its documentation at 32feet.NET: Stonestreet One Bluetopia stack.

Supported profiles and protocols

In version 1.10, Wireshark supports most Bluetooth profiles and protocols. The development version 1.11 (or later), is quite stable and can be used for Bluetooth purposes. It contains better Bluetooth support.

Profile/Protocol Filter name
Bluetooth HCI H1 hci_h1
Bluetooth HCI H4 hci_h4
Bluetooth HCI USB Transport hci_usb
Bluetooth Linux Monitor Transport hci_mon
Bluetooth 3DS Profile bt3ds
Bluetooth AMP Packet btamp
Bluetooth Attribute Protocol btatt
Bluetooth AVCTP Protocol btavctp
Bluetooth AVDTP Protocol btavdtp
Bluetooth A2DP Profile bta2dp
Bluetooth VDP Profile btvdp
Bluetooth AVRCP Profile btavrcp
Bluetooth BNEP Protocol btbnep
Bluetooth HCI ACL Packet bthci_acl
Bluetooth HCI Command bthci_cmd
Bluetooth HCI Event bthci_evt
Bluetooth HCI SCO Packet bthci_sco
Bluetooth HCRP Profile bthcrp
Bluetooth HFP Profile bthfp
Bluetooth HID Profile bthid
Bluetooth HSP Profile bthsp
Bluetooth L2CAP Protocol btl2cap
Bluetooth Low Energy Link Layer btle
Bluetooth Low Energy RF Info btle_rf
Bluetooth MCAP Protocol btmcap
Bluetooth OBEX Protocol btobex
Bluetooth RFCOMM Protocol btrfcomm
Bluetooth DUN Packet btdun
Bluetooth SPP Packet btspp
Bluetooth GNSS Profile btgnss
Bluetooth SAP Profile btsap
Bluetooth SDP Protocol btsdp
Bluetooth Security Manager Protocol btsmp
Related dissectors Filter name
Bluetooth Common btcommon
Bluetooth SBC Codec sbc
APT-X Codec aptx
Bluetooth A2DP Content Protection Header SCMS-T bta2dp_content_protection_header_scms_t
Bluetooth VDP Content Protection Header SCMS-T btvdp_content_protection_header_scms_t
Ubertooth ubertooth

Example capture file

External links


Imported from https://wiki.wireshark.org/Bluetooth on 2020-08-11 23:11:34 UTC