/Elastic-Sketch-P4

A P4 implementation of Elastic Sketch

Primary LanguagePythonApache License 2.0Apache-2.0

Implementing Elastic Sketch with P4

Introduction

This project is to implement a simple version of Elastic Sketch in SIGCOMM 2018 with P4.

Description of each file

  1. Makefile: the compiling file. Note that the program is running under the enviornment of P4 tutorial.

  2. receive_caida.py: using Scapy to receive CAIDA trace packets.

  3. receive_query.py: using Scapy to receive query packets (something like In-band Telemetry).

  4. s1-runtime.py: config the routing in s1, which need to seperate the flow of CAIDA trace and query.

  5. splitted: pcap file with 15M.

  6. test10P: pcap file with 10 packets, 8 packet with 1 occurence, 1 packet with 2 occurence

  7. test1M: pcap file with 1M.

  8. topology.json: topology file for mininet, the net has 4 hosts (h1, h2, h11, h22) and 1 switch (s1).

    • h1: send CAIDA trace, using tcpreply -i h1-eth0 -K test10P
    • h2: receive CAIDA trace, using ./receive_caida.py
    • h3: send query trace, using ./send_query.py
    • h4: receive query trace, using ./receive_query.py

  9. ES_heavy.p4: implement of Elastic Sketch.

The framework

Currently, I use BMV2 to run the test. The sketches is saved in extern Register. Unfortunately, P4 Runtime does not support acquire Register state. Therefore, I use a way like In-band Telemetry (INT) to query the state of Elastic Sketch in the P4 switch.

Another issue is that CAIDA traces do not have Ethernet packet. This is not a problem for software switch like OVS used by mininet. I can also send the packets in CAIDA traces withour adding a fake Ethernet header. Thus, when I process packets from CAIDA traces, I ignore the Ethernet header. However, everything is not OK. When I send a query packet with Scapy, I attach an Ethernet header for easy processing. This time the query packet cannot be processed using the CAIDA packet processing pipeline.

I find a wayout with the help of P4 community. P4 can parse packet based on ingress_port. So I send CAIDA packet to s1 from port s1-eth2 (connect to h1), and send query packet to s1 from s1-eth1 (connected to h11). In deparsing phrase, I simply send all headers (Ethernet, IPv4, ...) all to the egress_port.

I manually set the ip_protocol of query packets. If it is a query packet, it will send to s1-eth3 (connect to h22). otherwise it will go to s1-eth4 (connect to h2).

Query packet

In query packet, I manually set the ip_protocol to 63, and push the real ip_protocol to a field in IP_option. The count value is also saved in IP_option.

got a packet
###[ Ethernet ]###
  dst       = ff:ff:ff:ff:ff:ff
  src       = 00:00:00:00:01:0b
  type      = 0x800
###[ IP ]###
     version   = 4L
     ihl       = 6L
     tos       = 0x0
     len       = 24
     id        = 1
     flags     = 
     frag      = 0L
     ttl       = 64
     proto     = 63
     chksum    = 0xc450
     src       = 16.241.200.171
     dst       = 64.5.155.180
     \options   \
      |###[ QUERY ]###
      |  copy_flag = 0L
      |  optclass  = control
      |  option    = 31L
      |  count     = 2
      |  flow_proto= 6