netlink_packet_route/link/
header.rs

1// SPDX-License-Identifier: MIT
2
3use netlink_packet_core::{
4    DecodeError, Emitable, NlaBuffer, NlasIterator, Parseable,
5};
6
7use super::link_flag::LinkFlags;
8use crate::{link::LinkLayerType, AddressFamily};
9
10const LINK_HEADER_LEN: usize = 16;
11
12buffer!(LinkMessageBuffer(LINK_HEADER_LEN) {
13    interface_family: (u8, 0),
14    reserved_1: (u8, 1),
15    link_layer_type: (u16, 2..4),
16    link_index: (u32, 4..8),
17    flags: (u32, 8..12),
18    change_mask: (u32, 12..LINK_HEADER_LEN),
19    payload: (slice, LINK_HEADER_LEN..),
20});
21
22impl<'a, T: AsRef<[u8]> + ?Sized> LinkMessageBuffer<&'a T> {
23    pub fn attributes(
24        &self,
25    ) -> impl Iterator<Item = Result<NlaBuffer<&'a [u8]>, DecodeError>> {
26        NlasIterator::new(self.payload())
27    }
28}
29
30/// High level representation of `RTM_GETLINK`, `RTM_SETLINK`, `RTM_NEWLINK` and
31/// `RTM_DELLINK` messages headers.
32///
33/// These headers have the following structure:
34///
35/// ```no_rust
36/// 0                8                16              24               32
37/// +----------------+----------------+----------------+----------------+
38/// |interface family|    reserved    |         link layer type         |
39/// +----------------+----------------+----------------+----------------+
40/// |                             link index                            |
41/// +----------------+----------------+----------------+----------------+
42/// |                               flags                               |
43/// +----------------+----------------+----------------+----------------+
44/// |                            change mask                            |
45/// +----------------+----------------+----------------+----------------+
46/// ```
47///
48/// `LinkHeader` exposes all these fields except for the "reserved" one.
49#[derive(Debug, PartialEq, Eq, Clone, Default)]
50pub struct LinkHeader {
51    /// Address family: one of the `AF_*` constants.
52    /// The [AddressFamily] has `From<u8>` and `From<AddressFamily> for u8`
53    /// implemented.
54    pub interface_family: AddressFamily,
55    /// Link index.
56    pub index: u32,
57    /// Link type. It should be set to one of the `ARPHRD_*`
58    /// constants. The most common value is [LinkLayerType::Ether] for
59    /// Ethernet.
60    /// The LinkLayerType has `From<u16>` and `From<LinkLayerType> for u16`
61    /// implemented.
62    pub link_layer_type: LinkLayerType,
63    /// State of the link, described by a combinations of `IFF_*`
64    /// constants.
65    pub flags: LinkFlags,
66    /// Change mask for the `flags` field.
67    pub change_mask: LinkFlags,
68}
69
70impl Emitable for LinkHeader {
71    fn buffer_len(&self) -> usize {
72        LINK_HEADER_LEN
73    }
74
75    fn emit(&self, buffer: &mut [u8]) {
76        let mut packet = LinkMessageBuffer::new(buffer);
77        packet.set_interface_family(u8::from(self.interface_family));
78        packet.set_link_index(self.index);
79        packet.set_change_mask(self.change_mask.bits());
80        packet.set_link_layer_type(u16::from(self.link_layer_type));
81        packet.set_flags(self.flags.bits());
82    }
83}
84
85impl<T: AsRef<[u8]>> Parseable<LinkMessageBuffer<T>> for LinkHeader {
86    fn parse(buf: &LinkMessageBuffer<T>) -> Result<Self, DecodeError> {
87        Ok(Self {
88            interface_family: buf.interface_family().into(),
89            link_layer_type: buf.link_layer_type().into(),
90            index: buf.link_index(),
91            change_mask: LinkFlags::from_bits_retain(buf.change_mask()),
92            flags: LinkFlags::from_bits_retain(buf.flags()),
93        })
94    }
95}
netlink_packet_route/link/header.rs

netlink_packet_route/link/
header.rs
