README.md

Behavioral Model Backend

This is a back-end which generates code for the Behavioral Model version 2 (BMv2). https://github.com/p4lang/behavioral-model.git

It can accept either P4_14 programs, or P4_16 programs written for the v1model.p4 switch model.

Dependencies

To run and test this back-end you need some additional tools:

• the BMv2 behavioral model itself. Installation instructions are available at https://github.com/p4lang/behavioral-model.git. You may need to update your dynamic libraries after installing bmv2: sudo ldconfig

• the Python scapy and ipaddr libraries sudo pip3 install scapy ipaddr

Unsupported P4_16 language features

Here are some unsupported features we are aware of. We will update this list as more features get supported in the bmv2 compiler backend and as we discover more issues.

• explicit transition to reject in parse state

• compound action parameters (can only be bit<> or int<>)

• functions or methods with a compound return type

struct s_t {
    bit<8> f0;
    bit<8> f1;
};

extern s_t my_extern_function();

controlc c() {
    apply { s_t s1 = my_extern_function(); }
}

• user-defined extern types / methods which are not defined in v1model.p4

• stacks of header unions