Recent changes[0][1] have broken compatibility with macOS; add a patch
to conditionally compile these snippets.
Patch and compile the source unconditionally; caching only the network
portion is good enough and less error prone.
[0] ae18b94099
[1] 97169cd6d9
Before this change, Aya supported only legacy BPF map definitions, which
are instances of the `bpf_map_def` struct and end up in the `maps` ELF
section.
This change introduces a BTF map definition for arrays, with custom
structs indicating the metadata of the map, which end up in the `.maps`
section.
Co-authored-by: Tamir Duberstein <tamird@gmail.com>
eBPF verifier in recent kernels should be smart enough to track map
map types and catch invalid pointer casts. Rust type system makes sure
that the `get` method can return only the same type the map was created
with. Therefore, safe usage of Aya map types shouldn't cause element
type mismatches.
Manual alignment checks (`pointer::is_aligned` or manual pointer
arithmetic operations) cause the following verifier error:
```
bitwise operator &= on pointer prohibited
```
And it extremely unlikely `bpf_map_lookup_elem` ever returns a
misaligned pointer.
`bpf_map_def` is a legacy map definition. To be able to introduce BTF
map definitions, make the `lookup` and `remove` helpers work with
`c_void` and let the callers cast the map types to it.
Enables creation of Map enum variants directly from MapData instances,
allowing user-space handles to pinned BPF maps without requiring the
original BPF object.
Supports multiple BPF map types.
Motivation:
- Simplifies accessing pinned maps from user space applications.
- Avoids full BPF reloads and potential deadlocks.
- Matches existing ergonomic APIs like LruHashMap::try_from.
- Keeps user code safe and idiomatic.
Closes https://github.com/aya-rs/aya/issues/1305.
Includes test coverage to validate the new API.