bf7fdff1ce
This makes a few changes to the way that Aya reads the ELF object
files.
1. To find programs in a section, we use the symbols table. This allows
for cases where multiple programs could appear in the same section.
2. When parsing our ELF file we build symbols_by_section_index as an
optimization as we use it for legacy maps, BTF maps and now programs.
As a result of theses changes the "NAME" used in `bpf.prog_mut("NAME")`
is now ALWAYS the same as the function name in the eBPF code, making the
user experience more consistent.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
|
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();