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aya/README.md

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+# Aya
+
+[![Crates.io][crates-badge]][crates-url]
+![License][license-badge]
+![Build status][build-badge]
+
+[crates-badge]: https://img.shields.io/crates/v/aya.svg
+[crates-url]: https://crates.io/crates/aya
+[license-badge]: https://img.shields.io/badge/license-MIT%2FApache--2.0-blue
+[build-badge]: https://github.com/alessandrod/aya/actions/workflows/build-test.yml/badge.svg 
+
+[API docs][api-docs]
+
+## 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][co-re], 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.
+
+[api-docs]: https://docs.rs/aya
+[libbpf]: https://github.com/libbpf/libbpf
+[bcc]: https://github.com/iovisor/bcc
+[libc]: https://docs.rs/libc
+[co-re]: https://facebookmicrosites.github.io/bpf/blog/2020/02/19/bpf-portability-and-co-re.html 
+[tokio]: https://docs.rs/tokio
+[async-std]: https://docs.rs/async-std
+
+### 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:
+
+
+```rust
+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 th 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)?;
+```
+
+## 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. 
+
+[MIT license]: https://github.com/alessandrod/aya/blob/main/LICENSE-MIT
+[Apache license]: https://github.com/alessandrod/aya/blob/main/LICENSE-APACHE