libvnf

• libvnf is a library to easily build custom, scalable, high-performance, virtual network functions
• This is an implementation of paper libVNF: Building Virtual Network Functions Made Easy accepted in SoCC 2018
• Refer to release-socc branch for the above version

Features

• Written entirely in C++
• Aims to reduce lines of code without compromising on performance
• Has a non-blocking event-driven architecture
• Supports building of transport layer end-point VNFs as well as L2/L3 VNFs
• Supports kernel, kernel-bypass and L3 stacks [chosen at compile time]
• APIs are stack agnostic

Navigating Repo

• The headers are in include directory
• The implementations are in src directory
• Example VNFs that use libvnf are provided in examples dir
• Custom dependencies are listed in dependencies dir

Dependencies

• Before installation, the following dependencies need to be satisfied
  • cmake version >= 3.5.0
  • spdlog (https://github.com/gabime/spdlog)
  • boost (libboost-all-dev)
  • Kernel Stack
    • Install libsctp using sudo apt install libsctp-dev
    • While compiling the VNF, "-lsctp" flag needs to be used
  • Kernel-bypass stack
    • mTCP
    • netmap + vale switch
    • dpdk
    • numa (libnuma-dev)
    • Installation instructions can be found at dependencies/kernel_bypass_stack
  • Layer3 VNF
    • Netmap uses vale as the software switch. Follow steps (1-4) from here

Installation

• libvnf can be installed directly into the system using cmake
• In project root directory execute the following
  • mkdir build
  • cd build
  • cmake .. -DSTACK=KERNEL or cmake .. -DSTACK=KERNEL_BYPASS or cmake .. -DSTACK=L3VNF
  • make
  • sudo make install
• This creates and installs
  • a shared object (.so) version for of libvnf dynamic linking
  • an archive (.a) version of libvnf for static linking
• Dynamically linkable version of library will be named libvnf-{kernel/kernelbypass/l3}-dynamic.so
• Statically linkable version will be named libvnf-{kernel/kernelbypass/l3}-static.a
• CMake caches the options passed to it, so once passed there is no need to pass the option (-DSTACK=...) from second time
• If you want to change the stack, delete all files in build dir and run cmake again with required stack

How to use?

• Use #include <libvnf/core.hpp> header
• Refer to the abc example for a gentle introduction to APIs
• For compilation of your VNF you can just use -lvnf-kernel-static if you are using library compiled for kernel stack with static linkage. The other variants of linkage include flags -lvnf-{kernel,kernel-bypass,kernel-l3}-{static,dynamic}.

Optional Configuration

• While building I/O intensive applications on kernel stack run
  • ulimit -n 65535 as root
  • echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse as root

Notes on Optimization

• To achieve maximum possible performance make sure to use -O3 when compiling your VNF

Collaborators

1. Priyanka Naik
2. Yashasvi Sriram Patkuri
3. Sai Sandeep Moparthi
4. Akash Kanase
5. Trishal Patel
6. Sagar Tikore
7. Vaishali Jhalani
8. Prof. Mythili Vutukuru