5894c4ce82
* use the hdr_len of BTF.ext sections rather than size of struct Otherwise this will erroneously fail on older btf_ext_header that have less fields than the bindgen'd struct * do not attempt to load a BTF object that has no types * add tests * fix: hdr_len i32 -> u32 * guard against a bigger header in the future * use separate unsafe blocks * simplify writing to zero'd out header * merge safe block and address typo |
1 year ago | |
|---|---|---|
| .. | ||
| include | 2 years ago | |
| src | 1 year ago | |
| Cargo.toml | 1 year ago | |
| README.md | 2 years ago | |
README.md
aya-obj
Status
This crate includes code that started as internal API used by the aya crate. It has been split out so that it can be used by other projects that deal with eBPF object files. Unless you're writing low level eBPF plumbing tools, you should not need to use this crate but see the aya crate instead.
The API as it is today has a few rough edges and is generally not as polished nor stable as the main aya crate API. As always, improvements welcome!
Overview
eBPF programs written with libbpf or aya-bpf are usually compiled into an ELF object file, using various sections to store information about the eBPF programs.
aya-obj is a library for parsing such eBPF object files, with BTF and
relocation support.
Example
This example loads a simple eBPF program and runs it with rbpf.
use aya_obj::{generated::bpf_insn, Object};
// Parse the object file
let bytes = std::fs::read("program.o").unwrap();
let mut object = Object::parse(&bytes).unwrap();
// Relocate the programs
object.relocate_calls().unwrap();
object.relocate_maps(std::iter::empty()).unwrap();
// Run with rbpf
let instructions = &object.programs["prog_name"].function.instructions;
let data = unsafe {
core::slice::from_raw_parts(
instructions.as_ptr() as *const u8,
instructions.len() * core::mem::size_of::<bpf_insn>(),
)
};
let vm = rbpf::EbpfVmNoData::new(Some(data)).unwrap();
let _return = vm.execute_program().unwrap();