pktdev: Packet Character Device

Under development

Pktdev is a virtual network device for Shell/Command-based packet processing with high performance. Pktdev abstracts each NIC port as a common character device such as /dev/pkt/p2p1 and APIs for receiving and sending packets are only read(2) and write(2) system calls in the same manner a serial device. Packet processing applications is developed combining with 1. OS commands(dd, cat, etc), 2. UNIX PIPE(|), 3. Redirections(<, >) and 4. Pktdev.

Features

Support Linux 3.16 and newer kernel
Running on vanilla kernel and NIC driver
Multiple core packet sending
TX performance (2014/8, Intel Core i7 3770 + Intel 82599 NIC)
- Multiple core (best case): 12.5 Mpps using 4 CPU core
- Single core: XX Mpps
RX performance
- Multiple core: XX Gbps (XX Mpps)

Development platform

Linux (David Miller's -next networking tree)

Install

$ git clone git@github.com:sora/pktdev.git
$ cd pktdev
$ make
$ sudo insmod ./pktdev.ko interface="p2p1" tx_cpus="4" txring_size="32"
$ sudo chmod 777 /dev/pkt/p2p1
$ (cd cmd; make)
$ cmd/pktgen_stdout -s 60 -n 10 -m 10 > /dev/pkt/p2p1

Parameters

Name	about
interface	Target network interface
tx_cpus	Number of CPU cores for transmission
txring_size	Tx buffer size for each CPU cores

Applications

# one-way bridging (todo)
$ dd if=/dev/pkt/p2p1 of=/dev/pkt/p2p2

# capture (todo)
$ dd if=/dev/pkt/p2p1 of=recv.pkt

# traffic replay (todo)
$ dd if=./recv.pkt of=/dev/pkt/p2p1

# pktgen (64byte, 14880950 pkts)
$ cmd/pktgen_stdout -s 60 -n 41 -m 36295 > /dev/pkt/p2p1

# mirroring (todo)
$ cmd/btoa /dev/pkt/p2p1 | tee cmd/atob /dev/pkt/p2p1 | cmd/atob dev/pkt/p2p2

# One-liner VLAN packet filtering (todo)
$ cmd/btoa /dev/pkt/p2p1 | grep '8100 00 02' | cmd/atob /dev/pkt/p2p2

# capture traffic with pcapng format (todo)
$ cmd/pktdump -i /dev/rpkt/p2p1 -o recv.pcapng

packet format (version 1)

0                      16 (bit)
+-----------------------+
|  Magic code (0x3776)  |
+-----------------------+
|      Frame length     |
+-----------------------+
|                       |
|      Packet data      |
|                       |
+-----------------------+