62 lines
2.5 KiB
Markdown
62 lines
2.5 KiB
Markdown
# P4 Code Samples
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## Introduction
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This directory includes P4 code samples, meant to be run on bmv2, which
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illustrates several more advanced features of P4. The following samples are
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included:
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- `copy_to_cpu`: how to use the `clone_ingress_to_egress primitive` to clone the
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packet, encapsulate it and send it to a special port.
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- `meter`: how to use indirect meters in P4.
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- `TLV_parsing`: how to parse IPv4 options
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- `register`: how to use registers in P4 and read / write the state from the
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control plane
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All examples are orgranized the same way, with a `p4src` directory containing
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the P4 source code, and a `README` file describing the P4 program and explaining
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how to run a quick demonstration.
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## Obtaining required software
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To complete the exercises, you will need to clone 2 p4lang Github repositories
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and install their dependencies. To clonde the repositories:
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- `git clone https://github.com/p4lang/behavioral-model.git bmv2`
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- `git clone https://github.com/p4lang/p4c-bm.git p4c-bmv2`
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The first repository ([bmv2](https://github.com/p4lang/behavioral-model)) is the
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second version of the behavioral model. It is a C++ software switch that will
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behave according to your P4 program. The second repository
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([p4c-bmv2](https://github.com/p4lang/p4c-bm)) is the compiler for the
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behavioral model: it takes P4 program and output a JSON file which can be loaded
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by the behavioral model.
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Each of these repositories come with dependencies. `p4c-bmv2` is a Python
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repository and installing the required Python dependencies is very easy to do
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using `pip`: `sudo pip install -r requirements.txt`.
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`bmv2` is a C++ repository and has more external dependencies. They are listed
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in the
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[README](https://github.com/p4lang/behavioral-model/blob/master/README.md). If
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you are running Ubuntu 14.04+, the dependencies should be easy to install (you
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can use the `install_deps.sh` script that comes with `bmv2`). Do not forget to
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build the code once all the dependencies have been installed:
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- `./autogen.sh`
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- `./configure`
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- `make`
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## Before starting the exercises
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You need to tell us where you cloned the `bmv2` and `p4c-bm` repositories
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:). Please update the values of the shell variables `BMV2_PATH` and
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`P4C_BM_PATH` in the `env.sh` file - located in this directory. Note that if you
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cloned both repositories in the same directory as this one (`tutorials`), you
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will not need to change the value of the variables.
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You will also need to run the `veth_setup.sh` script included in this directory
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as `sudo` to setup the veth interfaces needed by the switch.
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That's all :)
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