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wlanPCAPWriter

PCAP or PCAPNG file writer of WLAN MAC packets

    Description

    The wlanPCAPWriter object writes generated and recovered WLAN medium access control (MAC) packets to a packet capture (PCAP) or packet capture next generation (PCAPNG) file (.pcap or .pcapng, respectively).

    Creation

    Description

    obj = wlanPCAPWriter creates a default WLAN PCAP or PCAPNG file writer object that writes WLAN MAC packets to a PCAP or PCAPNG file, respectively.

    example

    obj = wlanPCAPWriter(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.

    Properties

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    Note

    The wlanPCAPWriter object does not overwrite the existing PCAP or PCAPNG file. During each call of 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 vector or a string scalar.

    Data Types: char | string

    Name of the interface on which WLAN packets are captured, specified as a character vector or a string scalar.

    Data Types: char | string

    Flag to indicate the presence of radiotap, 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 protocol packet data to PCAP or PCAPNG file

    Examples

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

    pcapObj = wlanPCAPWriter('FileName','wlanExample', ...
        'FileExtension','pcap');

    Generate a WLAN MAC packet of type QoS Data.

    macConfig = wlanMACFrameConfig('FrameType','QoS Data');
    payload ='00576000103afffe80';
    mpdu = wlanMACFrame(payload,macConfig);

    Write the WLAN MAC packet to the PCAP file.

    timestamp = 0; % Number of microseconds
    write(pcapObj,mpdu,timestamp);

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

    pcapObj = wlanPCAPWriter('FileName','wlanExample2', ...
        'FileExtension','pcapng');

    Generate a WLAN MAC packet of type QoS Data.

    macConfig = wlanMACFrameConfig('FrameType','QoS Data');
    payload = '00576000103afffe80';
    mpdu = wlanMACFrame(payload,macConfig,'OutputFormat','bits');

    Write the WLAN MAC packet to the PCAPNG format file.

    timestamp = 12800000; % Number of microseconds
    write(pcapObj,mpdu,timestamp,'PacketFormat','bits');

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

    pcapObj = pcapngWriter('FileName','wlanExample3', ...
        'FileComment','This is a sample file');

    Create a WLAN PCAP file writer object, specifying the PCAP file writer and the presence of radiotap header.

    wlanPCAP = wlanPCAPWriter('PCAPWriter',pcapObj,'RadiotapPresent', ...
        true);

    Generate a WLAN MAC packet of type QoS Data.

    macConfig = wlanMACFrameConfig('FrameType','QoS Data');
    payload = '00576000103afffe80';
    mpdu = hex2dec(wlanMACFrame(payload,macConfig));

    Write the WLAN MAC packet to the PCAPNG file.

    radiotapBytes = [0 0 24 0 2 0 40 0 16 3 0 0 2 192 0 0 0 0 63 1 19 0 0 0];
    timestamp = 18912345; % Number of microseconds
    write(wlanPCAP,mpdu,timestamp,'Radiotap',radiotapBytes, ...
        'PacketComment','This is the first packet');

    References

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

    [2] “Radiotap - Introduction.” Accessed May 20, 2020. https://www.radiotap.org/.

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

    [4] “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™.

    See Also

    Objects

    Introduced in R2021a