Crate pktbuilder 

pktbuilder

A safe builder for building network packets.

A simple way to build packets is to give a buffer to Builder and use it’s methods to populate buffer with values.

use std::net::Ipv4Addr;
use pktbuilder::Builder;

fn example1() -> Result<(), pktbuilder::Error> {
    let mut buffer = [0u8; 6];
    let mut builder = Builder::new(&mut buffer);

    let ip = Ipv4Addr::new(192, 0, 2, 42);

    builder
        .add_byte(0x01)?
        .add_ipv4_address_be(ip)?
        .add_byte(0x02)?;

    assert_eq!(buffer, [0x01_u8, 192, 0, 2, 42, 0x02]);
    Ok(())
}

But for most cases we already have e.g. a struct that should be encoded so we can implement Buildable trait for the struct and use Buildable::build method to write into Builder:

use std::net::Ipv4Addr;
use pktbuilder::{Builder, Buildable};

struct Foo {
    foo: u8,
    ip: Ipv4Addr,
    bar: u8,
}

impl Buildable for Foo {
    fn build(&self, builder: &mut Builder<'_>) -> Result<(), pktbuilder::Error> {
        builder
            .add_byte(self.foo)?
            .add_ipv4_address_be(self.ip)?
            .add_byte(self.bar)?;
        Ok(())
    }
}


fn example2() -> Result<(), pktbuilder::Error> {
    let mut buffer = [0u8; 6];
    let mut builder = Builder::new(&mut buffer);

    let foo = Foo {
        foo: 0x01,
        ip: Ipv4Addr::new(192, 0, 2, 42),
        bar: 0x02,
    };

    foo.build(&mut builder)?;

    assert_eq!(buffer, [0x01_u8, 192, 0, 2, 42, 0x02]);
    Ok(())
}

Structs

Builder

Builder can be used to build packet into given buffer. Builder keeps internal index into the underlying buffer and all operations will advance this index.

Offset

Offset represents offset in a buffer.

Enums

Error

Error type for builder operations

Traits

Buildable

A data structure which can be encoded into byte array using Builder.