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pcapngWriter

PCAPNG file writer of protocol packets

Since R2020b

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    Description

    The pcapngWriter object writes generated and recovered protocol packets to a packet capture next generation (PCAPNG) file (.pcapng).

    You can write these packet types to a PCAPNG file:

    • Generated and recovered WLAN protocol packets

    • Generated and recovered 5G NR protocol packets (requires 5G Toolbox™)

    • Generated and recovered Bluetooth low energy (LE) link layer (LL) packets (requires Bluetooth® Toolbox)

    Creation

    Syntax

    pcapngObj = pcapngWriter
    pcapngObj = pcapngWriter(Name,Value)

    Description

    pcapngObj = pcapngWriter creates a default PCAPNG file writer object.

    pcapngObj = pcapngWriter(Name,Value) sets properties using one or more name-value pair arguments. Enclose each property name in quotes. For example, 'ByteOrder','big-endian' specifies the byte order as big-endian.

    example

    Properties

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    Note

    The pcapngWriter object does not overwrite the existing PCAPNG file. During each call of this object, specify a unique PCAPNG file name.

    Name of the 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

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

    Data Types: char | string

    Object Functions

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    writeWrite protocol packet data to PCAP or PCAPNG file
    writeCustomBlockWrite custom block to PCAPNG file
    writeInterfaceDescriptionBlockWrite interface description block to PCAPNG file

    Examples

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    Open Live Script

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

    pcapngObj = pcapngWriter('FileName','writeWLANpacket');

    Write the interface block for WLAN.

    interfaceName = 'WLAN';
wlanLinkType = 105;
interfaceId = writeInterfaceDescriptionBlock(pcapngObj,wlanLinkType, ...
    interfaceName);

    Specify a WLAN packet.

    mpdu = 'B4000000FFFFFFFFFFFF00123456789BA79A5B28';

    Specify the packet comment. Write the WLAN packet to the PCAPNG file, specifying the packet comment.

    timestamp = 0; % Number of microseconds
packetComment = 'This is the first packet';
write(pcapngObj,mpdu,timestamp,interfaceId,'PacketComment', ...
    packetComment);
    Open Live Script

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

    pcapngObj = pcapngWriter('FileName','writeWLANBLEpackets');

    Write the interface block for WLAN.

    interfaceName = 'WLAN';
wlanLinkType = 105;
interfaceId = writeInterfaceDescriptionBlock(pcapngObj,wlanLinkType, ...
    interfaceName);

    Specify a WLAN packet.

    mpdu = 'B4000000FFFFFFFFFFFF00123456789BA79A5B28';

    Specify the packet comment. Write the WLAN packet to the PCAPNG file, specifying the packet comment.

    timestamp = 0; % Number of microseconds
packetComment = 'This is a WLAN packet';
write(pcapngObj,mpdu,timestamp,interfaceId,'PacketComment', ...
    packetComment);

    Write the interface block for Bluetooth low energy (BLE).

    interfaceName = 'BLE';
bleLinkType = 251;
interfaceId = writeInterfaceDescriptionBlock(pcapngObj,bleLinkType, ...
    interfaceName);

    Specify a BLE packet.

    llpacket = '42BC13E206120E00050014010A001F0040001700170000007D47C0';

    Specify the packet comment. Write the BLE packet to the PCAPNG file, specifying the packet comment.

    timestamp = 0; % Number of microseconds
packetComment = 'This is a BLE packet';
write(pcapngObj,llpacket,timestamp,interfaceId,'PacketComment', ...
    packetComment);

    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™.

    Version History

    Introduced in R2020b

    See Also

    Objects