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use std::{
borrow::Cow,
collections::HashMap,
error::Error,
fs, io,
os::{raw::c_int, unix::io::RawFd},
path::{Path, PathBuf},
};
use thiserror::Error;
use crate::{
generated::{
bpf_map_type::BPF_MAP_TYPE_PERF_EVENT_ARRAY, AYA_PERF_EVENT_IOC_DISABLE,
AYA_PERF_EVENT_IOC_ENABLE, AYA_PERF_EVENT_IOC_SET_BPF,
},
maps::{Map, MapError, MapLock, MapRef, MapRefMut},
obj::{
btf::{Btf, BtfError},
Object, ParseError, ProgramSection,
},
programs::{
CgroupSkb, CgroupSkbAttachType, KProbe, LircMode2, PerfEvent, ProbeKind, Program,
ProgramData, ProgramError, SchedClassifier, SkMsg, SkSkb, SkSkbKind, SockOps, SocketFilter,
TracePoint, UProbe, Xdp,
},
sys::bpf_map_update_elem_ptr,
util::{possible_cpus, POSSIBLE_CPUS},
};
pub(crate) const BPF_OBJ_NAME_LEN: usize = 16;
pub(crate) const PERF_EVENT_IOC_ENABLE: c_int = AYA_PERF_EVENT_IOC_ENABLE;
pub(crate) const PERF_EVENT_IOC_DISABLE: c_int = AYA_PERF_EVENT_IOC_DISABLE;
pub(crate) const PERF_EVENT_IOC_SET_BPF: c_int = AYA_PERF_EVENT_IOC_SET_BPF;
/// Marker trait for types that can safely be converted to and from byte slices.
pub unsafe trait Pod: Copy + 'static {}
macro_rules! unsafe_impl_pod {
($($struct_name:ident),+ $(,)?) => {
$(
unsafe impl Pod for $struct_name { }
)+
}
}
unsafe_impl_pod!(i8, u8, i16, u16, i32, u32, i64, u64);
#[allow(non_camel_case_types)]
#[repr(C)]
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub(crate) struct bpf_map_def {
// minimum features required by old BPF programs
pub(crate) map_type: u32,
pub(crate) key_size: u32,
pub(crate) value_size: u32,
pub(crate) max_entries: u32,
pub(crate) map_flags: u32,
// optional features
pub(crate) id: u32,
pub(crate) pinning: PinningType,
}
#[repr(u32)]
#[derive(Copy, Clone, Debug, PartialEq)]
pub(crate) enum PinningType {
None = 0,
#[allow(dead_code)] // ByName is constructed from the BPF side
ByName = 1,
}
impl Default for PinningType {
fn default() -> Self {
PinningType::None
}
}
/// Builder style API for advanced loading of eBPF programs.
///
/// Loading eBPF code involves a few steps, including loading maps and applying
/// relocations. You can use `BpfLoader` to customize some of the loading
/// options.
///
/// # Examples
///
/// ```no_run
/// use aya::{BpfLoader, Btf};
/// use std::fs;
///
/// let bpf = BpfLoader::new()
/// // load the BTF data from /sys/kernel/btf/vmlinux
/// .btf(Btf::from_sys_fs().ok().as_ref())
/// // load pinned maps from /sys/fs/bpf/my-program
/// .map_pin_path("/sys/fs/bpf/my-program")
/// // finally load the code
/// .load_file("file.o")?;
/// # Ok::<(), aya::BpfError>(())
/// ```
#[derive(Debug)]
pub struct BpfLoader<'a> {
btf: Option<Cow<'a, Btf>>,
map_pin_path: Option<PathBuf>,
}
impl<'a> BpfLoader<'a> {
/// Creates a new loader instance.
pub fn new() -> BpfLoader<'a> {
BpfLoader {
btf: Btf::from_sys_fs().ok().map(Cow::Owned),
map_pin_path: None,
}
}
/// Sets the target [BTF](Btf) info.
///
/// The loader defaults to loading `BTF` info using [Btf::from_sys_fs].
/// Use this method if you want to load `BTF` from a custom location or
/// pass `None` to disable `BTF` relocations entirely.
/// # Example
///
/// ```no_run
/// use aya::{BpfLoader, Btf, Endianness};
///
/// let bpf = BpfLoader::new()
/// // load the BTF data from a custom location
/// .btf(Btf::parse_file("/custom_btf_file", Endianness::default()).ok().as_ref())
/// .load_file("file.o")?;
///
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn btf(&mut self, btf: Option<&'a Btf>) -> &mut BpfLoader<'a> {
self.btf = btf.map(Cow::Borrowed);
self
}
/// Sets the base directory path for pinned maps.
///
/// Pinned maps will be loaded from `path/MAP_NAME`.
///
/// # Example
///
/// ```no_run
/// use aya::BpfLoader;
///
/// let bpf = BpfLoader::new()
/// .map_pin_path("/sys/fs/bpf/my-program")
/// .load_file("file.o")?;
/// # Ok::<(), aya::BpfError>(())
/// ```
///
pub fn map_pin_path<P: AsRef<Path>>(&mut self, path: P) -> &mut BpfLoader<'a> {
self.map_pin_path = Some(path.as_ref().to_owned());
self
}
/// Loads eBPF bytecode from a file.
///
/// # Examples
///
/// ```no_run
/// use aya::BpfLoader;
///
/// let bpf = BpfLoader::new().load_file("file.o")?;
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn load_file<P: AsRef<Path>>(&mut self, path: P) -> Result<Bpf, BpfError> {
let path = path.as_ref();
self.load(&fs::read(path).map_err(|error| BpfError::FileError {
path: path.to_owned(),
error,
})?)
}
/// Loads eBPF bytecode from a buffer.
///
/// # Examples
///
/// ```no_run
/// use aya::BpfLoader;
/// use std::fs;
///
/// let data = fs::read("file.o").unwrap();
/// let bpf = BpfLoader::new().load(&data)?;
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn load(&mut self, data: &[u8]) -> Result<Bpf, BpfError> {
let mut obj = Object::parse(data)?;
if let Some(btf) = &self.btf {
obj.relocate_btf(btf)?;
}
let mut maps = Vec::new();
for (_, mut obj) in obj.maps.drain() {
if obj.def.map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY as u32 && obj.def.max_entries == 0
{
obj.def.max_entries = possible_cpus()
.map_err(|error| BpfError::FileError {
path: PathBuf::from(POSSIBLE_CPUS),
error,
})?
.len() as u32;
}
let mut map = Map {
obj,
fd: None,
pinned: false,
};
let fd = match map.obj.def.pinning {
PinningType::ByName => {
let path = match &self.map_pin_path {
Some(p) => p,
None => return Err(BpfError::NoPinPath),
};
// try to open map in case it's already pinned
match map.from_pinned(path) {
Ok(fd) => {
map.pinned = true;
fd as RawFd
}
Err(_) => {
let fd = map.create()?;
map.pin(path)?;
fd
}
}
}
PinningType::None => map.create()?,
};
if !map.obj.data.is_empty() && map.obj.name != ".bss" {
bpf_map_update_elem_ptr(fd, &0 as *const _, map.obj.data.as_mut_ptr(), 0).map_err(
|(code, io_error)| MapError::SyscallError {
call: "bpf_map_update_elem".to_owned(),
code,
io_error,
},
)?;
}
maps.push(map);
}
obj.relocate_maps(maps.as_slice())?;
obj.relocate_calls()?;
let programs = obj
.programs
.drain()
.map(|(name, obj)| {
let section = obj.section.clone();
let data = ProgramData {
obj,
name: name.clone(),
fd: None,
links: Vec::new(),
};
let program = match section {
ProgramSection::KProbe { .. } => Program::KProbe(KProbe {
data,
kind: ProbeKind::KProbe,
}),
ProgramSection::KRetProbe { .. } => Program::KProbe(KProbe {
data,
kind: ProbeKind::KRetProbe,
}),
ProgramSection::UProbe { .. } => Program::UProbe(UProbe {
data,
kind: ProbeKind::UProbe,
}),
ProgramSection::URetProbe { .. } => Program::UProbe(UProbe {
data,
kind: ProbeKind::URetProbe,
}),
ProgramSection::TracePoint { .. } => Program::TracePoint(TracePoint { data }),
ProgramSection::SocketFilter { .. } => {
Program::SocketFilter(SocketFilter { data })
}
ProgramSection::Xdp { .. } => Program::Xdp(Xdp { data }),
ProgramSection::SkMsg { .. } => Program::SkMsg(SkMsg { data }),
ProgramSection::SkSkbStreamParser { .. } => Program::SkSkb(SkSkb {
data,
kind: SkSkbKind::StreamParser,
}),
ProgramSection::SkSkbStreamVerdict { .. } => Program::SkSkb(SkSkb {
data,
kind: SkSkbKind::StreamVerdict,
}),
ProgramSection::SockOps { .. } => Program::SockOps(SockOps { data }),
ProgramSection::SchedClassifier { .. } => {
Program::SchedClassifier(SchedClassifier { data })
}
ProgramSection::CgroupSkbIngress { .. } => Program::CgroupSkb(CgroupSkb {
data,
expected_attach_type: Some(CgroupSkbAttachType::Ingress),
}),
ProgramSection::CgroupSkbEgress { .. } => Program::CgroupSkb(CgroupSkb {
data,
expected_attach_type: Some(CgroupSkbAttachType::Egress),
}),
ProgramSection::LircMode2 { .. } => Program::LircMode2(LircMode2 { data }),
ProgramSection::PerfEvent { .. } => Program::PerfEvent(PerfEvent { data }),
};
(name, program)
})
.collect();
Ok(Bpf {
maps: maps
.drain(..)
.map(|map| (map.obj.name.clone(), MapLock::new(map)))
.collect(),
programs,
})
}
}
impl<'a> Default for BpfLoader<'a> {
fn default() -> Self {
BpfLoader::new()
}
}
/// The main entry point into the library, used to work with eBPF programs and maps.
#[derive(Debug)]
pub struct Bpf {
maps: HashMap<String, MapLock>,
programs: HashMap<String, Program>,
}
impl Bpf {
/// Loads eBPF bytecode from a file.
///
/// Parses the given object code file and initializes the [maps](crate::maps) defined in it. If
/// the kernel supports [BTF](Btf) debug info, it is automatically loaded from
/// `/sys/kernel/btf/vmlinux`.
///
/// For more loading options, see [BpfLoader].
///
/// # Examples
///
/// ```no_run
/// use aya::Bpf;
///
/// let bpf = Bpf::load_file("file.o")?;
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn load_file<P: AsRef<Path>>(path: P) -> Result<Bpf, BpfError> {
BpfLoader::new()
.btf(Btf::from_sys_fs().ok().as_ref())
.load_file(path)
}
/// Loads eBPF bytecode from a buffer.
///
/// Parses the object code contained in `data` and initializes the
/// [maps](crate::maps) defined in it. If the kernel supports [BTF](Btf)
/// debug info, it is automatically loaded from `/sys/kernel/btf/vmlinux`.
///
/// For more loading options, see [BpfLoader].
///
/// # Examples
///
/// ```no_run
/// use aya::{Bpf, Btf};
/// use std::fs;
///
/// let data = fs::read("file.o").unwrap();
/// // load the BTF data from /sys/kernel/btf/vmlinux
/// let bpf = Bpf::load(&data)?;
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn load(data: &[u8]) -> Result<Bpf, BpfError> {
BpfLoader::new()
.btf(Btf::from_sys_fs().ok().as_ref())
.load(data)
}
/// Returns a reference to the map with the given name.
///
/// The returned type is mostly opaque. In order to do anything useful with it you need to
/// convert it to a [typed map](crate::maps).
///
/// For more details and examples on maps and their usage, see the [maps module
/// documentation][crate::maps].
///
/// # Errors
///
/// Returns [`MapError::MapNotFound`] if the map does not exist. If the map is already borrowed
/// mutably with [map_mut](Self::map_mut) then [`MapError::BorrowError`] is returned.
pub fn map(&self, name: &str) -> Result<MapRef, MapError> {
self.maps
.get(name)
.ok_or_else(|| MapError::MapNotFound {
name: name.to_owned(),
})
.and_then(|lock| {
lock.try_read().map_err(|_| MapError::BorrowError {
name: name.to_owned(),
})
})
}
/// Returns a mutable reference to the map with the given name.
///
/// The returned type is mostly opaque. In order to do anything useful with it you need to
/// convert it to a [typed map](crate::maps).
///
/// For more details and examples on maps and their usage, see the [maps module
/// documentation][crate::maps].
///
/// # Errors
///
/// Returns [`MapError::MapNotFound`] if the map does not exist. If the map is already borrowed
/// mutably with [map_mut](Self::map_mut) then [`MapError::BorrowError`] is returned.
pub fn map_mut(&self, name: &str) -> Result<MapRefMut, MapError> {
self.maps
.get(name)
.ok_or_else(|| MapError::MapNotFound {
name: name.to_owned(),
})
.and_then(|lock| {
lock.try_write().map_err(|_| MapError::BorrowError {
name: name.to_owned(),
})
})
}
/// An iterator over all the maps.
///
/// # Examples
/// ```no_run
/// # let mut bpf = aya::Bpf::load(&[])?;
/// for (name, map) in bpf.maps() {
/// println!(
/// "found map `{}` of type `{:?}`",
/// name,
/// map?.map_type().unwrap()
/// );
/// }
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn maps(&self) -> impl Iterator<Item = (&str, Result<MapRef, MapError>)> {
let ret = self.maps.iter().map(|(name, lock)| {
(
name.as_str(),
lock.try_read()
.map_err(|_| MapError::BorrowError { name: name.clone() }),
)
});
ret
}
/// Returns a reference to the program with the given name.
///
/// You can use this to inspect a program and its properties. To load and attach a program, use
/// [program_mut](Self::program_mut) instead.
///
/// For more details on programs and their usage, see the [programs module
/// documentation](crate::programs).
///
/// # Errors
///
/// Returns [`ProgramError::NotFound`] if the program does not exist.
///
/// # Examples
///
/// ```no_run
/// # let bpf = aya::Bpf::load(&[])?;
/// let program = bpf.program("SSL_read")?;
/// println!("program SSL_read is of type {:?}", program.prog_type());
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn program(&self, name: &str) -> Result<&Program, ProgramError> {
self.programs
.get(name)
.ok_or_else(|| ProgramError::NotFound {
name: name.to_owned(),
})
}
/// Returns a mutable reference to the program with the given name.
///
/// Used to get a program before loading and attaching it. For more details on programs and
/// their usage, see the [programs module documentation](crate::programs).
///
/// # Errors
///
/// Returns [`ProgramError::NotFound`] if the program does not exist.
///
/// # Examples
///
/// ```no_run
/// # let mut bpf = aya::Bpf::load(&[])?;
/// use aya::programs::UProbe;
/// use std::convert::TryInto;
///
/// let program: &mut UProbe = bpf.program_mut("SSL_read")?.try_into()?;
/// program.load()?;
/// program.attach(Some("SSL_read"), 0, "libssl", None)?;
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn program_mut(&mut self, name: &str) -> Result<&mut Program, ProgramError> {
self.programs
.get_mut(name)
.ok_or_else(|| ProgramError::NotFound {
name: name.to_owned(),
})
}
/// An iterator over all the programs.
///
/// # Examples
/// ```no_run
/// # let mut bpf = aya::Bpf::load(&[])?;
/// for program in bpf.programs() {
/// println!(
/// "found program `{}` of type `{:?}`",
/// program.name(),
/// program.prog_type()
/// );
/// }
/// # Ok::<(), aya::BpfError>(())
/// ```
pub fn programs(&self) -> impl Iterator<Item = &Program> {
self.programs.values()
}
}
/// The error type returned by [`Bpf::load_file`] and [`Bpf::load`].
#[derive(Debug, Error)]
pub enum BpfError {
#[error("error loading {path}")]
FileError {
path: PathBuf,
#[source]
error: io::Error,
},
#[error("pinning requested but no path provided")]
NoPinPath,
#[error("unexpected pinning type {name}")]
UnexpectedPinningType { name: u32 },
#[error("invalid path `{error}`")]
InvalidPath { error: String },
#[error("error parsing BPF object")]
ParseError(#[from] ParseError),
#[error("BTF error")]
BtfError(#[from] BtfError),
#[error("error relocating `{function}`")]
RelocationError {
function: String,
#[source]
error: Box<dyn Error + Send + Sync>,
},
#[error("map error")]
MapError(#[from] MapError),
#[error("program error")]
ProgramError(#[from] ProgramError),
}