netlink_packet_route/link/
header.rs

1// SPDX-License-Identifier: MIT
2
3use netlink_packet_utils::{
4    nla::{NlaBuffer, NlasIterator},
5    traits::{Emitable, Parseable},
6    DecodeError,
7};
8
9use crate::{link::LinkLayerType, AddressFamily};
10
11use super::link_flag::LinkFlags;
12
13const LINK_HEADER_LEN: usize = 16;
14
15buffer!(LinkMessageBuffer(LINK_HEADER_LEN) {
16    interface_family: (u8, 0),
17    reserved_1: (u8, 1),
18    link_layer_type: (u16, 2..4),
19    link_index: (u32, 4..8),
20    flags: (u32, 8..12),
21    change_mask: (u32, 12..LINK_HEADER_LEN),
22    payload: (slice, LINK_HEADER_LEN..),
23});
24
25impl<'a, T: AsRef<[u8]> + ?Sized> LinkMessageBuffer<&'a T> {
26    pub fn attributes(
27        &self,
28    ) -> impl Iterator<Item = Result<NlaBuffer<&'a [u8]>, DecodeError>> {
29        NlasIterator::new(self.payload())
30    }
31}
32
33/// High level representation of `RTM_GETLINK`, `RTM_SETLINK`, `RTM_NEWLINK` and
34/// `RTM_DELLINK` messages headers.
35///
36/// These headers have the following structure:
37///
38/// ```no_rust
39/// 0                8                16              24               32
40/// +----------------+----------------+----------------+----------------+
41/// |interface family|    reserved    |         link layer type         |
42/// +----------------+----------------+----------------+----------------+
43/// |                             link index                            |
44/// +----------------+----------------+----------------+----------------+
45/// |                               flags                               |
46/// +----------------+----------------+----------------+----------------+
47/// |                            change mask                            |
48/// +----------------+----------------+----------------+----------------+
49/// ```
50///
51/// `LinkHeader` exposes all these fields except for the "reserved" one.
52#[derive(Debug, PartialEq, Eq, Clone, Default)]
53pub struct LinkHeader {
54    /// Address family: one of the `AF_*` constants.
55    /// The [AddressFamily] has `From<u8>` and `From<AddressFamily> for u8`
56    /// implemented.
57    pub interface_family: AddressFamily,
58    /// Link index.
59    pub index: u32,
60    /// Link type. It should be set to one of the `ARPHRD_*`
61    /// constants. The most common value is [LinkLayerType::Ether] for
62    /// Ethernet.
63    /// The LinkLayerType has `From<u16>` and `From<LinkLayerType> for u16`
64    /// implemented.
65    pub link_layer_type: LinkLayerType,
66    /// State of the link, described by a combinations of `IFF_*`
67    /// constants.
68    pub flags: LinkFlags,
69    /// Change mask for the `flags` field.
70    pub change_mask: LinkFlags,
71}
72
73impl Emitable for LinkHeader {
74    fn buffer_len(&self) -> usize {
75        LINK_HEADER_LEN
76    }
77
78    fn emit(&self, buffer: &mut [u8]) {
79        let mut packet = LinkMessageBuffer::new(buffer);
80        packet.set_interface_family(u8::from(self.interface_family));
81        packet.set_link_index(self.index);
82        packet.set_change_mask(self.change_mask.bits());
83        packet.set_link_layer_type(u16::from(self.link_layer_type));
84        packet.set_flags(self.flags.bits());
85    }
86}
87
88impl<T: AsRef<[u8]>> Parseable<LinkMessageBuffer<T>> for LinkHeader {
89    fn parse(buf: &LinkMessageBuffer<T>) -> Result<Self, DecodeError> {
90        Ok(Self {
91            interface_family: buf.interface_family().into(),
92            link_layer_type: buf.link_layer_type().into(),
93            index: buf.link_index(),
94            change_mask: LinkFlags::from_bits_retain(buf.change_mask()),
95            flags: LinkFlags::from_bits_retain(buf.flags()),
96        })
97    }
98}
netlink_packet_route/link/header.rs

netlink_packet_route/link/
header.rs
