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use crate::{bindings::bpf_cpumap_val, btf_maps::btf_map_def};
btf_map_def!(
/// A BTF-compatible array of CPUs available for XDP redirect.
///
/// XDP programs use this map to redirect packets to a target CPU for
/// processing via [`CpuMap::redirect`]. Userspace populates each slot
/// with a `struct bpf_cpumap_val` carrying the per-CPU queue size and
/// an optional chained XDP program; on kernels older than 5.9 only the
/// `qsize` field is honoured and aya truncates the value size to 4
/// bytes at map creation.
///
/// # Minimum kernel version
///
/// The minimum kernel version required to use this feature is 4.15.
///
/// # Example
///
/// ```rust
/// use aya_ebpf::{btf_maps::CpuMap, macros::btf_map};
///
/// #[btf_map]
/// static CPUS: CpuMap<8> = CpuMap::new();
/// ```
pub struct CpuMap<; const MAX_ENTRIES: usize, const FLAGS: usize = 0>,
map_type: BPF_MAP_TYPE_CPUMAP,
max_entries: MAX_ENTRIES,
map_flags: FLAGS,
key_type: u32,
value_type: bpf_cpumap_val,
);
impl<const MAX_ENTRIES: usize, const FLAGS: usize> CpuMap<MAX_ENTRIES, FLAGS> {
const _CHECK: () = {
assert!(
MAX_ENTRIES > 0,
"CpuMap max_entries must be greater than zero.",
);
};
/// Redirects the current packet to the CPU at `index`.
///
/// On lookup miss the kernel encodes the fallback XDP action in the
/// lower two bits of `flags`, propagated as the `Err` variant.
#[inline(always)]
pub fn redirect(&self, index: u32, flags: u64) -> Result<u32, u32> {
let () = Self::_CHECK;
super::try_redirect_map(self.as_ptr(), index, flags)
}
}