#![cfg(target_os = "linux")]

//! Rust bindings for working with XDP programs & eBPF maps.
//!
//! This library has bindings for some of the common, basic operations needed when working with
//! XDP programs & eBPF maps from user-space. It is built on top of [libbpf-sys][1]. At the time
//! of writing, it supports only a subset of all the possibe eBPF map types (see tests directory
//! for a good indication of which maps are supported).
//!
//! ## Prerequisites
//! * Linux OS
//! * libbpf-sys [dependencies][2]
//!
//! [1]: https://github.com/alexforster/libbpf-sys
//! [2]: https://github.com/alexforster/libbpf-sys#building
//!
//! ## Examples
//! ### Create an object from an ELF file
//! ```no_run
//! use rxdp;
//!
//! let obj_path = "/path/to/elf/file";
//! let obj = match rxdp::XDPObject::new(obj_path) {
//!     Ok(obj) => {
//!         println!("Successfully created object from {}", obj_path);
//!         obj
//!     },
//!     Err(err) => panic!("{:?}", err),
//! };
//! ```
//!
//! ### Set the pinned maps.
//! Maps that have already been pinned will be loaded from the fs, provided the map name
//! matches the name in the fs. Any new maps in the HashSet will set the pin path so that
//! once the program is loaded, they will get automatically pinned.
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap();
//! # use std::collections::HashSet;
//!
//! let mut pinned_maps = HashSet::new();
//! let pin_path = None; // Will default to /sys/fs/bpf
//! pinned_maps.insert("my_map_name".to_string());
//! obj.pinned_maps(&pinned_maps, pin_path).unwrap();
//! ```
//!
//! ### Load the object (programs + maps) into the kernel.
//! This will consume the [`XDPObject`](crate::object::XDPObject) created above and return
//! an [`XDPLoadedObject`](crate::object::XDPLoadedObject).
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap();
//! let obj = obj.load().unwrap();
//! ```
//!
//! ### Get a reference to a specific XDP program and attach it to an interface
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! let dev = "eth0";
//! let flags = rxdp::AttachFlags::SKB_MODE;
//!
//! let prog = obj.get_program("prog_name").unwrap();
//! match prog.attach_to_interface(dev, flags) {
//!     Ok(_) => println!("Successfully attached to {}", dev),
//!     Err(e) => panic!("{:?}", e),
//! }
//!```
//!
//! ### Get access to an underlying eBPF [`Map`](crate::Map)
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! use rxdp::MapLike;
//!
//! let m: rxdp::Map<u32, u64> = rxdp::Map::new(&obj, "map_name").unwrap();
//!```
//! **NOTE**: the key/value sizes **MUST** match the key/value sizes defined in the eBPF code,
//! otherwise creating the map will fail.
//!
//! ### Perform map operations
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! # let m: rxdp::Map<u32, u64> = rxdp::Map::new(&obj, "map_name").unwrap();
//! use rxdp::MapLike;
//!
//! let key = 0u32;
//! let value = 1000u64;
//! m.update(&key, &value, rxdp::MapFlags::BpfAny).unwrap();
//! let got = m.lookup(&key).unwrap();
//! assert_eq!(value, got.into_single());
//!
//! // iterate through all items
//! for kv in m.items().unwrap() {
//!     println!("key: {}, value: {}", kv.key, kv.value.into_single());
//! }
//!```
//!
//! ### For per-cpu maps, use [`PerCpuMap`](crate::PerCpumap)
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! let m: rxdp::PerCpuMap<u32, u64> = rxdp::PerCpuMap::new(&obj, "map_name").unwrap();
//! ```
//! **NOTE**: the key size **MUST** match the key size defined in the eBPF code, otherwise creating the map will fail.

//! ### Per CPU map operations
//! Per CPU maps return the [`MapValue::Multi(Vec<T>)`](crate::MapValue) variant during lookup,
//! one for each possible CPU:
//! ```no_run
//! # use rxdp;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! # let m = rxdp::PerCpuMap::<u32, u64>::new(&obj, "map_name").unwrap();
//! use rxdp::MapLike;
//!
//! let key = 0u32;
//! let value = 1000u64;
//! m.update(&key, &value, rxdp::MapFlags::BpfAny).unwrap();
//! let got = m.lookup(&key).unwrap();
//! assert_eq!(got.into_vec(), vec![value; rxdp::num_cpus()]);

//! // iterate through all items
//! for kv in m.items().unwrap() {
//!     println!("key: {}", kv.key);
//!     for v in kv.value.into_vec() {
//!         println!("value: {}", v);
//!     }
//! }
//! ```
//!
//! ### Perf event Map
//! Perf events sent from eBPF can be retrieved via [`PerfMap`](crate::PerfMap).
//! ```no_run
//! # use rxdp;
//! # use crossbeam_channel::Receiver;
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! let mut perfmap = rxdp::PerfMap::<u32>::new(&obj, "map_name").unwrap();
//! let r: Receiver<rxdp::PerfEvent<u32>> = perfmap.start_polling(10000);
//!
//! // Wait for events on the receiver side of the channel
//! loop {
//!     r.recv().map_or_else(
//!         |e| println!("error: {:?}", e),
//!         |event| println!("event: {:?}", event),
//!     );
//! }
//!
//! ```
//! ### Batching support (kernel dependent)
//! If the kernel supports it, you can do batch operations for update/lookups:
//! ```no_run
//! # let obj = rxdp::XDPObject::new("/tmp/foo").unwrap().load().unwrap();
//! # let m: rxdp::Map<u32, u64> = rxdp::Map::new(&obj, "map_name").unwrap();
//! use rxdp::MapLike;
//!
//! if rxdp::is_batching_supported() {
//!     let mut next_key = None;
//!     let r = m.lookup_batch(10u32, next_key).unwrap();
//!     // do something with r.items...
//!     next_key = r.next_key;
//! }
//! ```
//!

#![doc(html_root_url = "https://docs.rs/rxdp/0.3.1")]
mod macros;

mod error;
mod map;
mod map_batch;
mod map_common;
mod map_flags;
mod map_types;
mod object;
mod percpu_map;
mod perf_event_handler;
mod perf_map;
mod program;
mod result;
mod utils;

pub use error::XDPError;
pub use map::Map;
pub use map_batch::{is_batching_supported, BatchResult};
pub use map_common::{KeyValue, MapLike, MapValue};
pub use map_flags::MapFlags;
pub use map_types::MapType;
pub use object::{load_pinned_object, XDPLoadedObject, XDPObject};
pub use percpu_map::{num_cpus, ByteAligned, PerCpuMap};
pub use perf_map::{EventType, PerfEvent, PerfMap};
pub use program::{AttachFlags, XDPProgram};
pub use result::XDPResult;