packetdumper

A kotlin / android compatible buffer / packet dumper.

Usage

Add the dependency to your project:

implementation("com.jasonernst.packetdumper:packetdumper:<version>")

pcapng tcp server

This will start a TCP server on port 19000 that will accept connections from wireshark as follows:

wireshark -k -i TCP@<ip>:19000

val dumper = PcapNgTcpServerPacketDumper()
dumper.start()
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
dumper.dumpBuffer(buffer, 0, buffer.limit(), false, null)

//    ...

dumper.stop()

pcapng file

Note that the file will actually be created with timestamps in the filename so that multiple runs will not overwrite each other.

val dumper = PcapNgFilePacketDumper("/tmp", "test", "pcapng")
dumper.open()
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
dumper.dumpBuffer(buffer, 0, buffer.limit(), false, null)
dumper.close()

hexdump to file

The following will dump in a format which is compatible with a wireshark hexdump import. This assumes that the buffer contains an ipv4 packet. If your buffer has an ethernet frame already just leave this as null.

val dumper = TextFilePacketDumper("/tmp", "test", "txt")
dumper.open()
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
dumper.dumpBuffer(buffer, 0, buffer.limit(), true, EtherType.IPv4)
dumper.close()

hexdump to stdout

val dumper = StringPacketDumper(writeToStdOut = true)
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
dumper.dumpBuffer(buffer, 0, buffer.limit(), true, EtherType.IPv4)

hexdump to slf4j logger

This will log at the info level to the slf4j logger provided.

val logger = LoggerFactor.getLogger("somelogger")
val dumper = StringPacketDumper(logger)
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
dumper.dumpBuffer(buffer, 0, buffer.limit(), true, EtherType.IPv4)

hexdump to string

val dumper = StringPacketDumper()
val buffer = ByteBuffer.wrap(byteArrayOf(0x01, 0x02, 0x03, 0x04))
val hexString = dumper.dumpBufferToString(buffer, 0, buffer.limit(), true, EtherType.IPv4)
println(hexString)

TODO

• Support options for pcap blocks