pcapWriter

PCAP file writer of protocol packets

Since R2020b

Description

The pcapWriter object writes generated and recovered protocol packets to a packet capture (PCAP) file (.pcap).

You can write these packet types to a PCAP file:

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

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

• Generated and recovered WLAN protocol packets (requires WLAN Toolbox™)

Creation

Syntax

pcapObj = pcapWriter

pcapObj = pcapWriter(Name,Value)

Description

pcapObj = pcapWriter creates a default PCAP file writer object.

pcapObj = pcapWriter(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.

Properties

Note

The pcapWriter object does not overwrite the existing PCAP file. Each time when you call this object, specify a unique PCAP file name.

FileName — Name of the PCAP file

'capture' (default) | character row vector | string scalar

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

Data Types: char | string

ByteOrder — Byte order

'little-endian' (default) | 'big-endian'

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

Data Types: char | string

Object Functions

Specific to This Object

write	Write protocol packet data to PCAP or PCAPNG file
writeGlobalHeader	Write global header to PCAP file

Examples

Write Bluetooth LE Link Layer Packet to PCAP File

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

pcapObj = pcapWriter('FileName','writeBluetoothLE');
bleLinkType = 251;

Write a global header to the PCAP file.

writeGlobalHeader(pcapObj,bleLinkType);

Specify a Bluetooth LE LL packet.

llpacket = '42BC13E206120E00050014010A001F0040001700170000007D47C0';

Write the Bluetooth LE LL packet to the PCAP file.

timestamp = 129100;                % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
write(pcapObj,llpacket,timestamp);

References

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

[2] “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