Struct xsk_rs::umem::FrameDesc

pub struct FrameDesc<'umem> { /* fields omitted */ }

Describes a UMEM frame's address and size of its current contents.

The addr field is an offset in bytes from the start of the UMEM and corresponds to some point within a frame. The len field describes the length (in bytes) of any data stored in that frame, starting from addr.

If sending data, the len field will need to be set by the user before transmitting via the TxQueue. Otherwise when reading received frames using the RxQueue, the len field will be set by the kernel and dictates the number of bytes the user should read from the UMEM.

Implementations

impl FrameDesc<'_>

pub fn addr(&self) -> usize

pub fn len(&self) -> usize

pub fn options(&self) -> u32

pub fn set_addr(&mut self, addr: usize)

Set the frame descriptor's address. This determines where in the UMEM it references.

Manual setting shouldn't generally be required is likely best avoided since the setting of addresses is handled by the library, however it may be needed if writing straight to a region in UMEM via umem_region_mut or umem_region_mut_checked

pub fn set_len(&mut self, len: usize)

Set the frame descriptor's length. This should equal the length of the data stored at addr.

Once data has been written to the UMEM region starting at addr, this FrameDesc's length must be updated before handing it over to the kernel to be transmitted to ensure the correct number of bytes are sent.

Manual setting shouldn't generally be required and if copying packets to UMEM it's better to use write_to_umem or write_to_umem_checked which will handle setting the frame descriptor length, however it may be needed if writing to a UMEM region manually (see set_addr) or if, for example, the data you want to send is already at addr and you just need to set the length before transmission.

pub fn set_options(&mut self, options: u32)

Set the frame descriptor options.

Trait Implementations

impl<'umem> Clone for FrameDesc<'umem>

fn clone(&self) -> FrameDesc<'umem>

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'umem> Debug for FrameDesc<'umem>

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

Formats the value using the given formatter.

impl<'umem> PartialEq<FrameDesc<'umem>> for FrameDesc<'umem>

fn eq(&self, other: &FrameDesc<'umem>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &FrameDesc<'umem>) -> bool

This method tests for !=.

impl<'umem> StructuralPartialEq for FrameDesc<'umem>