This commit includes example tutorials and solutions for P4D2 2017. (#29)

- Added example P4 programs for ipv4_forwarding, mri, arp, calc
- Added python code to invoke compiler, start bmv2, run mininet
- Added solutions to above programs
- Added README files that describe exercises

P4D2_2017/exercises/README.md

@@ -0,0 +1,63 @@
+# P4 Tutorial
+
+## Introduction
+
+Welcome to the P4 Tutorial!
+
+We've prepared a set of four exercises that will help you get started
+with P4 programming:
+
+1.  [L3 forwarding](./ipv4_forward)
+
+2.  [Multi-Hop Route Inspection](./mri)
+
+3.  [ARP/ICMP Responder](./arp)
+
+4.  [Calculator](./calc)
+
+## Obtaining required software
+
+If you are starting this tutorial as part of the P4 Developer Day, then
+we've already provided you with a virtual machine that has all of the
+required software installed.
+
+Otherwise, to complete the exercises, you will need to clone two p4lang Github repositories
+and install their dependencies. To clonde the repositories:
+
+- `git clone https://github.com/p4lang/behavioral-model.git bmv2`
+- `git clone https://github.com/p4lang/p4c-bm.git p4c-bmv2`
+
+The first repository ([bmv2](https://github.com/p4lang/behavioral-model)) is the
+second version of the behavioral model. It is a C++ software switch that will
+behave according to your P4 program. The second repository
+([p4c-bmv2](https://github.com/p4lang/p4c-bm)) is the compiler for the
+behavioral model: it takes P4 program and output a JSON file which can be loaded
+by the behavioral model.
+
+Each of these repositories come with dependencies. `p4c-bmv2` is a Python
+repository and installing the required Python dependencies is very easy to do
+using `pip`: `sudo pip install -r requirements.txt`.
+
+`bmv2` is a C++ repository and has more external dependencies. They are listed
+in the
+[README](https://github.com/p4lang/behavioral-model/blob/master/README.md). If
+you are running Ubuntu 14.04+, the dependencies should be easy to install (you
+can use the `install_deps.sh` script that comes with `bmv2`). Do not forget to
+build the code once all the dependencies have been installed:
+
+```
+$ ./autogen.sh
+$ ./configure
+$ make
+```
+
+
+You will also need to install `mininet`, as well as the following Python
+packages: `scapy`, `thrift` (>= 0.9.2) and `networkx`. On Ubuntu, it would look
+like this:
+
+```
+$ sudo apt-get install mininet
+$ sudo pip install scapy thrift networkx
+```
+