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blePCAPWriter

PCAP or PCAPNG file writer of Bluetooth LE LL packets

Since R2020b

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    Description

    The blePCAPWriter object writes generated and recovered Bluetooth® low energy (LE) link layer (LL) packets to a packet capture (PCAP) or packet capture next generation (PCAPNG) file (.pcap or .pcapng, respectively).

    Creation

    Syntax

    obj = blePCAPWriter
    obj = blePCAPWriter(Name,Value)

    Description

    obj = blePCAPWriter creates a default Bluetooth LE PCAP or PCAPNG file writer object that writes Bluetooth LE LL packets to a PCAP or PCAPNG file, respectively.

    obj = blePCAPWriter(Name,Value) sets properties using one or more name-value pairs. Enclose each property name in quotes. For example, ('FileExtension','pcapng') sets the extension of the file as .pcapng.

    example

    Properties

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    Note

    The blePCAPWriter object does not overwrite the existing PCAP or PCAPNG file. Each time when you create this object, specify a unique PCAP or PCAPNG file name.

    Name of the PCAP or PCAPNG file, specified as a character row vector or a string scalar.

    Data Types: char | string

    Byte order, specified as 'little-endian' or 'big-endian'.

    Data Types: char | string

    Type of file, specified as 'pcap' or 'pcapng'.

    Data Types: char | string

    Comment for the PCAPNG file, specified as a character row vector or a string scalar.

    Dependencies

    To enable this property, set the FileExtension property to 'pcapng'.

    Data Types: char | string

    Name of the device that captures Bluetooth LE packets, specified as a character row vector or a string scalar.

    Dependencies

    To enable this property, set the FileExtension property to 'pcapng'.

    Data Types: char | string

    Flag to indicate the presence of physical layer (PHY) header, specified as a logical 1 (true) or 0 (false).

    Data Types: logical

    PCAP or PCAPNG file writer object, specified as pcapWriter or pcapngWriter object.

    Object Functions

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    writeWrite Bluetooth LE LL protocol packet data to PCAP or PCAPNG file

    Examples

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    Open Live Script

    Create a Bluetooth LE PCAP file writer object, specifying the name of the PCAP file.

    pcapObj = blePCAPWriter('FileName','writeblepacket');

    Generate a Bluetooth LE LL packet.

    cfgLLData = bleLLDataChannelPDUConfig('LLID', ...
    'Data (start fragment/complete)');
payload = '0E00050014010A001F004000170017000000';
llDataPDU = bleLLDataChannelPDU(cfgLLData,payload);
connAccessAddress = int2bit(hex2dec('E213BC42'),32,false);
llpacket = [connAccessAddress; llDataPDU];

    Write the Bluetooth LE LL packet to the PCAP file.

    timestamp = 0;                                           % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
write(pcapObj,llpacket,timestamp,'PacketFormat','bits');
    Open Live Script

    Create a Bluetooth LE PCAPNG file writer object, specifying the name and extension of the PCAPNG file.

    pcapObj = blePCAPWriter('FileName','sampleBLELL', ...
    'FileExtension','pcapng');

    Generate a Bluetooth LE LL packet.

    cfgLLData = bleLLDataChannelPDUConfig('LLID', ...
    'Data (start fragment/complete)');
payload = '0E00050014010A001F004000170017000000';
llDataPDU = bleLLDataChannelPDU(cfgLLData,payload);
connAccessAddress = int2bit(hex2dec('E213BC42'),32,false);
llpacket = [connAccessAddress; llDataPDU];

    Write the Bluetooth LE LL packet to the PCAPNG file.

    timestamp = 12800000;                                   % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
write(pcapObj,llpacket,timestamp,'PacketFormat','bits');
    Open Live Script

    Create a PCAPNG file writer object, specifying the name of the PCAPNG file.

    pcapObj = pcapngWriter('FileName','sampleBLELL', ...
    'FileComment','This is a sample file');

    Create a Bluetooth LE PCAP file writer object, specifying the PCAPNG file writer and the presence of PHY header.

    blePCAP = blePCAPWriter('PCAPWriter',pcapObj,'PhyHeaderPresent',true);

    Generate a Bluetooth LE LL packet.

    cfgLLAdv = bleLLAdvertisingChannelPDUConfig;
cfgLLAdv.PDUType = 'Advertising indication';
cfgLLAdv.AdvertisingData = '020106';
llDataPDU = bleLLAdvertisingChannelPDU(cfgLLAdv);
connAccessAddress = int2bit(hex2dec('E213BC42'),32,false);
llpacket = [connAccessAddress;llDataPDU];

    Write the Bluetooth LE LL packet to the PCAPNG file.

    PhyHeaderBytes = [39 10 8 1 10 10 10 10 15 00];
timestamp = 18912345;                                       % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
write(blePCAP,llpacket,timestamp,'PacketFormat','bits', ...
    'PhyHeader',PhyHeaderBytes, ...
    'PacketComment','This is the first packet');

    References

    [1] Tuexen, M. “PCAP Next Generation (Pcapng) Capture File Format.” 2020. https://www.ietf.org/.

    [2] Group, The Tcpdump. “Tcpdump/Libpcap Public Repository.” Accessed May 20, 2020. https://www.tcpdump.org.

    [3] “Development/LibpcapFileFormat - The Wireshark Wiki.” Accessed May 20, 2020. https://www.wireshark.org.

    Extended Capabilities

    C/C++ Code Generation
    Generate C and C++ code using MATLAB® Coder™.

    Version History

    Introduced in R2020b

    See Also

    Objects

    Topics