FExit

Struct FExit 

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pub struct FExit { /* private fields */ }
Expand description

A program that can be attached to the exit point of (almost) anny kernel function.

FExit programs are similar to kretprobes, but the difference is that fexit has practically zero overhead to call before kernel function. Fexit programs can be also attached to other eBPF programs.

§Minimum kernel version

The minimum kernel version required to use this feature is 5.5.

§Examples

use aya::{Ebpf, programs::FExit, BtfError, Btf};

let btf = Btf::from_sys_fs()?;
let program: &mut FExit = bpf.program_mut("filename_lookup").unwrap().try_into()?;
program.load("filename_lookup", &btf)?;
program.attach()?;

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impl FExit

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pub fn load(&mut self, fn_name: &str, btf: &Btf) -> Result<(), ProgramError>

Loads the program inside the kernel.

Loads the program so it’s executed when the kernel function fn_name is exited. The btf argument must contain the BTF info for the running kernel.

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pub fn attach(&mut self) -> Result<FExitLinkId, ProgramError>

Attaches the program.

The returned value can be used to detach, see FExit::detach.

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pub fn detach(&mut self, link_id: FExitLinkId) -> Result<(), ProgramError>

Detaches the program.

See FExit::attach.

Takes ownership of the link referenced by the provided link_id.

The link will be detached on Drop and the caller is now responsible for managing its lifetime.

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impl FExit

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pub fn unload(&mut self) -> Result<(), ProgramError>

Unloads the program from the kernel.

Links will be detached before unloading the program. Note that owned links obtained using take_link() will not be detached.

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impl FExit

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pub fn fd(&self) -> Result<&ProgramFd, ProgramError>

Returns the file descriptor of this Program.

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impl FExit

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pub fn pin<P: AsRef<Path>>(&mut self, path: P) -> Result<(), PinError>

Pins the program to a BPF filesystem.

When a BPF object is pinned to a BPF filesystem it will remain loaded after Aya has unloaded the program. To remove the program, the file on the BPF filesystem must be removed. Any directories in the the path provided should have been created by the caller.

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pub fn unpin(self) -> Result<(), Error>

Removes the pinned link from the filesystem.

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impl FExit

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pub fn from_pin<P: AsRef<Path>>(path: P) -> Result<Self, ProgramError>

Creates a program from a pinned entry on a bpffs.

Existing links will not be populated. To work with existing links you should use crate::programs::links::PinnedLink.

On drop, any managed links are detached and the program is unloaded. This will not result in the program being unloaded from the kernel if it is still pinned.

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impl FExit

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pub fn info(&self) -> Result<ProgramInfo, ProgramError>

Returns metadata information of this program.

Uses kernel v4.13 features.

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impl Debug for FExit

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl Drop for FExit

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fn drop(&mut self)

Executes the destructor for this type. Read more
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impl<'a> TryFrom<&'a Program> for &'a FExit

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type Error = ProgramError

The type returned in the event of a conversion error.
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fn try_from(program: &'a Program) -> Result<&'a FExit, ProgramError>

Performs the conversion.
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impl<'a> TryFrom<&'a mut Program> for &'a mut FExit

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type Error = ProgramError

The type returned in the event of a conversion error.
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fn try_from(program: &'a mut Program) -> Result<&'a mut FExit, ProgramError>

Performs the conversion.

Auto Trait Implementations§

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impl Freeze for FExit

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impl RefUnwindSafe for FExit

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impl Send for FExit

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impl Sync for FExit

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impl Unpin for FExit

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impl UnwindSafe for FExit

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.