1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
use crate::*;
use core::slice::from_raw_parts;
///A slice containing an ethernet 2 header of a network package.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Ethernet2HeaderSlice<'a> {
pub(crate) slice: &'a [u8],
}
impl<'a> Ethernet2HeaderSlice<'a> {
/// Creates a ethernet slice from an other slice.
pub fn from_slice(slice: &'a [u8]) -> Result<Ethernet2HeaderSlice<'a>, err::LenError> {
//check length
if slice.len() < Ethernet2Header::LEN {
return Err(err::LenError {
required_len: Ethernet2Header::LEN,
len: slice.len(),
len_source: LenSource::Slice,
layer: err::Layer::Ethernet2Header,
layer_start_offset: 0,
});
}
//all done
Ok(Ethernet2HeaderSlice {
// SAFETY:
// Safe as slice length is checked to be at least
// Ethernet2Header::LEN (14) before this.
slice: unsafe { from_raw_parts(slice.as_ptr(), Ethernet2Header::LEN) },
})
}
/// Converts the given slice into a ethernet 2 header slice WITHOUT any
/// checks to ensure that the data present is an ethernet 2 header or that the
/// slice length is matching the header length.
///
/// If you are not sure what this means, use [`Ethernet2HeaderSlice::from_slice`]
/// instead.
///
/// # Safety
///
/// The caller must ensured that the given slice has the length of
/// [`Ethernet2Header::LEN`]
#[inline]
#[cfg(feature = "std")]
pub(crate) unsafe fn from_slice_unchecked(slice: &[u8]) -> Ethernet2HeaderSlice {
debug_assert!(slice.len() == Ethernet2Header::LEN);
Ethernet2HeaderSlice { slice }
}
/// Returns the slice containing the ethernet 2 header
#[inline]
pub fn slice(&self) -> &'a [u8] {
self.slice
}
/// Read the destination MAC address
#[inline]
pub fn destination(&self) -> [u8; 6] {
// SAFETY:
// Safe as the contructor checks that the slice has
// at least the length of Ethernet2Header::LEN (14).
unsafe { get_unchecked_6_byte_array(self.slice.as_ptr()) }
}
/// Read the source MAC address
#[inline]
pub fn source(&self) -> [u8; 6] {
// SAFETY:
// Safe as the contructor checks that the slice has
// at least the length of Ethernet2Header::LEN (14).
unsafe { get_unchecked_6_byte_array(self.slice.as_ptr().add(6)) }
}
/// Read the ether_type field of the header indicating the protocol
/// after the header.
#[inline]
pub fn ether_type(&self) -> EtherType {
// SAFETY:
// Safe as the contructor checks that the slice has
// at least the length of Ethernet2Header::LEN (14).
EtherType(unsafe { get_unchecked_be_u16(self.slice.as_ptr().add(12)) })
}
/// Decode all the fields and copy the results to a [`Ethernet2Header`] struct
pub fn to_header(&self) -> Ethernet2Header {
Ethernet2Header {
source: self.source(),
destination: self.destination(),
ether_type: self.ether_type(),
}
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::test_gens::*;
use alloc::{format, vec::Vec};
use proptest::prelude::*;
proptest! {
#[test]
fn from_slice(
input in ethernet_2_any(),
dummy_data in proptest::collection::vec(any::<u8>(), 0..20)
) {
// serialize
let mut buffer: Vec<u8> = Vec::with_capacity(14 + dummy_data.len());
input.write(&mut buffer).unwrap();
buffer.extend(&dummy_data[..]);
// calls with a valid result
{
let result = Ethernet2HeaderSlice::from_slice(&buffer[..]).unwrap();
assert_eq!(&buffer[..14], result.slice());
}
// call with not enough data in the slice
for len in 0..=13 {
assert_eq!(
Ethernet2HeaderSlice::from_slice(&buffer[..len]),
Err(err::LenError{
required_len: Ethernet2Header::LEN,
len: len,
len_source: LenSource::Slice,
layer: err::Layer::Ethernet2Header,
layer_start_offset: 0,
})
);
}
}
}
proptest! {
#[test]
fn getters(input in ethernet_2_any()) {
let buffer = input.to_bytes();
let slice = Ethernet2HeaderSlice::from_slice(&buffer).unwrap();
assert_eq!(input.destination, slice.destination());
assert_eq!(input.source, slice.source());
assert_eq!(input.ether_type, slice.ether_type());
}
}
proptest! {
#[test]
fn to_header(input in ethernet_2_any()) {
let buffer = input.to_bytes();
let slice = Ethernet2HeaderSlice::from_slice(&buffer).unwrap();
assert_eq!(input, slice.to_header());
}
}
proptest! {
#[test]
fn clone_eq(input in ethernet_2_any()) {
let buffer = input.to_bytes();
let slice = Ethernet2HeaderSlice::from_slice(&buffer).unwrap();
assert_eq!(slice, slice.clone());
}
}
proptest! {
#[test]
fn dbg(input in ethernet_2_any()) {
let buffer = input.to_bytes();
let slice = Ethernet2HeaderSlice::from_slice(&buffer).unwrap();
assert_eq!(
&format!(
"Ethernet2HeaderSlice {{ slice: {:?} }}",
slice.slice()
),
&format!("{:?}", slice)
);
}
}
}