ad1636d2e7
This changes PerfBuffer::read_events() to call BytesMut::reserve()
internally, and deprecates PerfBufferError::MoreSpaceNeeded.
This makes for a more ergonomic API, and allows for a more idiomatic
usage of BytesMut. For example consider:
let mut buffers = vec![BytesMut::with_capacity(N), ...];
loop {
let events = oob_cpu_buf.read_events(&mut buffers).unwrap();
for buf in &mut buffers[..events.read] {
let sub: Bytes = buf.split_off(n).into();
process_sub_buf(sub);
}
...
}
This is a common way to process perf bufs, where a sub buffer is split
off from the original buffer and then processed. In the next iteration
of the loop when it's time to read again, two things can happen:
- if processing of the sub buffer is complete and `sub` has been
dropped, read_events() will call buf.reserve(sample_size) and hit a fast
path in BytesMut that will just restore the original capacity of the
buffer (assuming sample_size <= N).
- if processing of the sub buffer hasn't ended (eg the buffer has been
stored or is being processed in another thread),
buf.reserve(sample_size) will actually allocate the new memory required
to read the sample.
In other words, calling buf.reserve(sample_size) inside read_events()
simplifies doing zero-copy processing of buffers in many cases.
|
3 years ago | |
|---|---|---|
| .cargo | 4 years ago | |
| .github | 3 years ago | |
| .vim | 4 years ago | |
| .vscode | 4 years ago | |
| aya | 3 years ago | |
| aya-gen | 3 years ago | |
| bpf | 3 years ago | |
| images | 3 years ago | |
| test | 3 years ago | |
| xtask | 3 years ago | |
| .gitignore | 4 years ago | |
| CONTRIBUTING.md | 4 years ago | |
| Cargo.toml | 4 years ago | |
| LICENSE-APACHE | 4 years ago | |
| LICENSE-MIT | 4 years ago | |
| README.md | 3 years ago | |
| rustfmt.toml | 4 years ago | |
README.md
Aya
API docs | Chat | Aya-Related Projects
Overview
eBPF is a technology that allows running user-supplied programs inside the Linux kernel. For more info see https://ebpf.io/what-is-ebpf.
Aya is an eBPF library built with a focus on operability and developer experience. It does not rely on libbpf nor bcc - it's built from the ground up purely in Rust, using only the libc crate to execute syscalls. With BTF support and when linked with musl, it offers a true compile once, run everywhere solution, where a single self-contained binary can be deployed on many linux distributions and kernel versions.
Some of the major features provided include:
- Support for the BPF Type Format (BTF), which is transparently enabled when supported by the target kernel. This allows eBPF programs compiled against one kernel version to run on different kernel versions without the need to recompile.
- Support for function call relocation and global data maps, which allows eBPF programs to make function calls and use global variables and initializers.
- Async support with both tokio and async-std.
- Easy to deploy and fast to build: aya doesn't require a kernel build or compiled headers, and not even a C toolchain; a release build completes in a matter of seconds.
Example
Aya supports a large chunk of the eBPF API. The following example shows how to use a
BPF_PROG_TYPE_CGROUP_SKB program with aya:
use std::fs::File;
use std::convert::TryInto;
use aya::Bpf;
use aya::programs::{CgroupSkb, CgroupSkbAttachType};
// load the BPF code
let mut bpf = Bpf::load_file("bpf.o")?;
// get the `ingress_filter` program compiled into `bpf.o`.
let ingress: &mut CgroupSkb = bpf.program_mut("ingress_filter")?.try_into()?;
// load the program into the kernel
ingress.load()?;
// attach the program to the root cgroup. `ingress_filter` will be called for all
// incoming packets.
let cgroup = File::open("/sys/fs/cgroup/unified")?;
ingress.attach(cgroup, CgroupSkbAttachType::Ingress)?;
Community
Join the conversation on Discord to discuss anything related to aya.
Contributing
Please see the contributing guide.
License
Aya is distributed under the terms of either the MIT license or the Apache License (version 2.0), at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.