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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252
use crate::err::ValueTooBigError;
/// 6 bit unsigned integer containing the "Differentiated Services
/// Code Point" (present in the [`crate::Ipv4Header`]).
#[derive(Copy, Clone, Default, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct Ipv4Dscp(u8);
impl Ipv4Dscp {
/// Ipv4Dscp with value 0.
pub const ZERO: Ipv4Dscp = Ipv4Dscp(0);
/// Maximum value of an IPv4 header DSCP.
pub const MAX_U8: u8 = 0b0011_1111;
/// Tries to create an [`Ipv4Dscp`] and checks that the passed value
/// is smaller or equal than [`Ipv4Dscp::MAX_U8`] (6 bit unsigned integer).
///
/// In case the passed value is bigger then what can be represented in an 6 bit
/// integer an error is returned. Otherwise an `Ok` containing the [`Ipv4Dscp`].
///
/// ```
/// use etherparse::Ipv4Dscp;
///
/// let dscp = Ipv4Dscp::try_new(32).unwrap();
/// assert_eq!(dscp.value(), 32);
///
/// // if a number that can not be represented in an 6 bit integer
/// // gets passed in an error is returned
/// use etherparse::err::{ValueTooBigError, ValueType};
/// assert_eq!(
/// Ipv4Dscp::try_new(Ipv4Dscp::MAX_U8 + 1),
/// Err(ValueTooBigError{
/// actual: Ipv4Dscp::MAX_U8 + 1,
/// max_allowed: Ipv4Dscp::MAX_U8,
/// value_type: ValueType::Ipv4Dscp,
/// })
/// );
/// ```
#[inline]
pub const fn try_new(value: u8) -> Result<Ipv4Dscp, ValueTooBigError<u8>> {
use crate::err::ValueType;
if value <= Ipv4Dscp::MAX_U8 {
Ok(Ipv4Dscp(value))
} else {
Err(ValueTooBigError {
actual: value,
max_allowed: Ipv4Dscp::MAX_U8,
value_type: ValueType::Ipv4Dscp,
})
}
}
/// Creates an [`Ipv4Dscp`] without checking that the value
/// is smaller or equal than [`Ipv4Dscp::MAX_U8`] (6 bit unsigned integer).
/// The caller must guarantee that `value <= Ipv4Dscp::MAX_U8`.
///
/// # Safety
///
/// `value` must be smaller or equal than [`Ipv4Dscp::MAX_U8`]
/// otherwise the behavior of functions or data structures relying
/// on this pre-requirement is undefined.
#[inline]
pub const unsafe fn new_unchecked(value: u8) -> Ipv4Dscp {
debug_assert!(value <= Ipv4Dscp::MAX_U8);
Ipv4Dscp(value)
}
/// Returns the underlying unsigned 6 bit value as an `u8` value.
#[inline]
pub const fn value(self) -> u8 {
self.0
}
}
impl core::fmt::Display for Ipv4Dscp {
#[inline]
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
self.0.fmt(f)
}
}
impl From<Ipv4Dscp> for u8 {
#[inline]
fn from(value: Ipv4Dscp) -> Self {
value.0
}
}
impl TryFrom<u8> for Ipv4Dscp {
type Error = ValueTooBigError<u8>;
#[inline]
fn try_from(value: u8) -> Result<Self, Self::Error> {
use crate::err::ValueType;
if value <= Ipv4Dscp::MAX_U8 {
Ok(Ipv4Dscp(value))
} else {
Err(Self::Error {
actual: value,
max_allowed: Ipv4Dscp::MAX_U8,
value_type: ValueType::Ipv4Dscp,
})
}
}
}
#[cfg(test)]
mod test {
use super::*;
use core::hash::{Hash, Hasher};
use proptest::prelude::*;
use std::format;
#[test]
fn derived_traits() {
// copy & clone
{
let a = Ipv4Dscp(32);
let b = a;
assert_eq!(a, b);
assert_eq!(a.clone(), a);
}
// default
{
let actual: Ipv4Dscp = Default::default();
assert_eq!(actual.value(), 0);
}
// debug
{
let a = Ipv4Dscp(32);
assert_eq!(format!("{:?}", a), format!("Ipv4Dscp(32)"));
}
// ord & partial ord
{
use core::cmp::Ordering;
let a = Ipv4Dscp(32);
let b = a;
assert_eq!(a.cmp(&b), Ordering::Equal);
assert_eq!(a.partial_cmp(&b), Some(Ordering::Equal));
}
// hash
{
use std::collections::hash_map::DefaultHasher;
let a = {
let mut hasher = DefaultHasher::new();
Ipv4Dscp(64).hash(&mut hasher);
hasher.finish()
};
let b = {
let mut hasher = DefaultHasher::new();
Ipv4Dscp(64).hash(&mut hasher);
hasher.finish()
};
assert_eq!(a, b);
}
}
proptest! {
#[test]
fn try_new(
valid_value in 0..=0b0011_1111u8,
invalid_value in 0b0100_0000u8..=u8::MAX
) {
use crate::err::{ValueType, ValueTooBigError};
assert_eq!(
valid_value,
Ipv4Dscp::try_new(valid_value).unwrap().value()
);
assert_eq!(
Ipv4Dscp::try_new(invalid_value).unwrap_err(),
ValueTooBigError{
actual: invalid_value,
max_allowed: 0b0011_1111,
value_type: ValueType::Ipv4Dscp
}
);
}
}
proptest! {
#[test]
fn try_from(
valid_value in 0..=0b0011_1111u8,
invalid_value in 0b0100_0000u8..=u8::MAX
) {
use crate::err::{ValueType, ValueTooBigError};
// try_into
{
let actual: Ipv4Dscp = valid_value.try_into().unwrap();
assert_eq!(actual.value(), valid_value);
let err: Result<Ipv4Dscp, ValueTooBigError<u8>> = invalid_value.try_into();
assert_eq!(
err.unwrap_err(),
ValueTooBigError{
actual: invalid_value,
max_allowed: 0b0011_1111,
value_type: ValueType::Ipv4Dscp
}
);
}
// try_from
{
assert_eq!(
Ipv4Dscp::try_from(valid_value).unwrap().value(),
valid_value
);
assert_eq!(
Ipv4Dscp::try_from(invalid_value).unwrap_err(),
ValueTooBigError{
actual: invalid_value,
max_allowed: 0b0011_1111,
value_type: ValueType::Ipv4Dscp
}
);
}
}
}
proptest! {
#[test]
fn new_unchecked(valid_value in 0..=0b0011_1111u8) {
assert_eq!(
valid_value,
unsafe {
Ipv4Dscp::new_unchecked(valid_value).value()
}
);
}
}
proptest! {
#[test]
fn fmt(valid_value in 0..=0b0011_1111u8) {
assert_eq!(format!("{}", Ipv4Dscp(valid_value)), format!("{}", valid_value));
}
}
proptest! {
#[test]
fn from(valid_value in 0..=0b0011_1111u8,) {
let dscp = Ipv4Dscp::try_new(valid_value).unwrap();
let actual: u8 = dscp.into();
assert_eq!(actual, valid_value);
}
}
}