//! A message body behind a correct header, so that the fuzzer spends its
//! time in the OPEN, UPDATE and NOTIFICATION parsers and not on guessing
//! the marker and length. The first byte picks the message type and what
//! the session settled: see `bgp_fuzz::Session`.
#![no_main]

use libfuzzer_sys::fuzz_target;

/// The longest body that fits a BGP message (4096 less the 19-byte header).
const MAX_BODY: usize = 4096 - 19;

fuzz_target!(|data: &[u8]| {
    let Some((selector, body)) = data.split_first() else {
        return;
    };
    let body = &body[..body.len().min(MAX_BODY)];
    // Bits 1 to 3; the others pick the session.
    let msg_type = 1 + ((selector >> 1) & 0x07) % 5;

    let mut wire = vec![0xff; 16];
    wire.extend_from_slice(&((19 + body.len()) as u16).to_be_bytes());
    wire.push(msg_type);
    wire.extend_from_slice(body);
    bgp_fuzz::decode_and_check(bgp_fuzz::Session::from_bits(*selector), &wire);
});