virtio_drivers/device/net/
net_buf.rs

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1use super::{VirtioNetHdr, NET_HDR_SIZE};
2use alloc::{vec, vec::Vec};
3use core::{convert::TryInto, mem::size_of};
4use zerocopy::AsBytes;
5
6/// A buffer used for transmitting.
7pub struct TxBuffer(pub(crate) Vec<u8>);
8
9/// A buffer used for receiving.
10pub struct RxBuffer {
11    pub(crate) buf: Vec<usize>, // for alignment
12    pub(crate) packet_len: usize,
13    pub(crate) idx: u16,
14}
15
16impl TxBuffer {
17    /// Constructs the buffer from the given slice.
18    pub fn from(buf: &[u8]) -> Self {
19        Self(Vec::from(buf))
20    }
21
22    /// Returns the network packet length.
23    pub fn packet_len(&self) -> usize {
24        self.0.len()
25    }
26
27    /// Returns the network packet as a slice.
28    pub fn packet(&self) -> &[u8] {
29        self.0.as_slice()
30    }
31
32    /// Returns the network packet as a mutable slice.
33    pub fn packet_mut(&mut self) -> &mut [u8] {
34        self.0.as_mut_slice()
35    }
36}
37
38impl RxBuffer {
39    /// Allocates a new buffer with length `buf_len`.
40    pub(crate) fn new(idx: usize, buf_len: usize) -> Self {
41        Self {
42            buf: vec![0; buf_len / size_of::<usize>()],
43            packet_len: 0,
44            idx: idx.try_into().unwrap(),
45        }
46    }
47
48    /// Set the network packet length.
49    pub(crate) fn set_packet_len(&mut self, packet_len: usize) {
50        self.packet_len = packet_len
51    }
52
53    /// Returns the network packet length (witout header).
54    pub const fn packet_len(&self) -> usize {
55        self.packet_len
56    }
57
58    /// Returns all data in the buffer, including both the header and the packet.
59    pub fn as_bytes(&self) -> &[u8] {
60        self.buf.as_bytes()
61    }
62
63    /// Returns all data in the buffer with the mutable reference,
64    /// including both the header and the packet.
65    pub fn as_bytes_mut(&mut self) -> &mut [u8] {
66        self.buf.as_bytes_mut()
67    }
68
69    /// Returns the reference of the header.
70    pub fn header(&self) -> &VirtioNetHdr {
71        unsafe { &*(self.buf.as_ptr() as *const VirtioNetHdr) }
72    }
73
74    /// Returns the network packet as a slice.
75    pub fn packet(&self) -> &[u8] {
76        &self.buf.as_bytes()[NET_HDR_SIZE..NET_HDR_SIZE + self.packet_len]
77    }
78
79    /// Returns the network packet as a mutable slice.
80    pub fn packet_mut(&mut self) -> &mut [u8] {
81        &mut self.buf.as_bytes_mut()[NET_HDR_SIZE..NET_HDR_SIZE + self.packet_len]
82    }
83}
virtio_drivers/device/net/net_buf.rs

virtio_drivers/device/net/
net_buf.rs
