domain/rdata/svcb/params.rs
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//! Handling of service binding parameters.
//!
//! This is a private module. It’s public types are re-exported by the
//! parent.
// Currently a false positive on SvcParams. We cannot apply it there because
// the allow attribute doesn't get copied to the code generated by serde.
#![allow(clippy::needless_maybe_sized)]
use super::value::AllValues;
use crate::base::cmp::CanonicalOrd;
use crate::base::iana::SvcParamKey;
use crate::base::scan::Symbol;
use crate::base::wire::{Compose, Parse, ParseError};
use octseq::builder::{EmptyBuilder, FromBuilder, OctetsBuilder, ShortBuf};
use octseq::octets::{Octets, OctetsFrom, OctetsInto};
use octseq::parse::{Parser, ShortInput};
use core::{cmp, fmt, hash, mem};
use core::cmp::Ordering;
use core::marker::PhantomData;
//------------ SvcParams -----------------------------------------------------
/// A sequence of service binding parameters.
///
/// These parameters provide information helpful when trying to connect to an
/// endpoint offering a service. They consist of a sequence of parameter
/// values. Each value has a type and some data specific to that type. The
/// type is provided through a `u16` key with values assigned via an IANA
/// registry. The key and registry are available through
/// [`SvcParamKey`]. Each key is only allowed to appear at most once in the
/// parameter sequence. Values need to be ordered by their key’s integer value.
///
/// A value of the `SvcParams` type contains a sequence of values in their
/// wire-format encoded form. It guarantees that this content is correctly
/// encoded. It does not guarantee that the content of the individual
/// parameter value is correct. It also does not guarantee any size limit
/// to the octets sequence.
///
/// You can create a value of this type through parsing or manually via
/// [`from_octets`][Self::from_octets] or [`from_slice`][Self::from_slice].
/// You can also build a new value from scratch via the [`SvcParamsBuilder`].
/// The [`from_values`][Self::from_values] function provides a shortcut that
/// crates the builder, passes it to a closure, and returns the finished
/// parameter sequence.
///
/// Access to the values of the parameter sequence happens through a mechanism
/// similar to record data: Various types exist that implement either a
/// specific value type or a group of types. These types need to implement the
/// [`SvcParamValue`] and [`ParseSvcParamValue`] traits to be used to access
/// values. They can be used as a type parameter to the [`iter`][Self::iter]
/// method to acquire an iterator over all the values that they understand.
/// Since every concrete value can only be present once, the
/// [`first`][Self::first] method can be used together with a value type
/// implementing that concrete value to get the value if present. As a
/// convenience, methods exist for every currently defined value type which
/// return a value of that type if present.
///
/// The type [`UnknownSvcParam`] can be used to represent any value type with
/// the value as a octets sequence. The [`AllValues`] enum provides typed
/// access to all known value types.
///
/// # Wire Format
///
/// The wire format of a parameter sequence consists of a sequence of
/// values. Each value is encoded as a 16 bit parameter key – represented
/// by [`SvcParamKey`] in this crate –, followed by an unsigned 16 bit length
/// value, followed by this many octets. Since the sequence is the last element
/// in the record data, it is limited by the length of the record data only.
#[derive(Clone, Default)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[repr(transparent)]
pub struct SvcParams<Octs: ?Sized> {
#[cfg_attr(
feature = "serde",
serde(
serialize_with =
"octseq::serde::SerializeOctets::serialize_octets",
deserialize_with =
"octseq::serde::DeserializeOctets::deserialize_octets",
bound(
serialize = "Octs: octseq::serde::SerializeOctets",
deserialize =
"Octs: octseq::serde::DeserializeOctets<'de> + Sized",
)
)
)]
octets: Octs,
}
impl<Octs> SvcParams<Octs> {
/// Creates a parameter sequence from an octets sequence.
///
/// The method checks that `octets` contains a parameter sequence that is
/// correctly encoded in wire format. It does not check that the
/// individual values are correctly encoded. It also does not check for
/// any length limit.
pub fn from_octets(octets: Octs) -> Result<Self, SvcParamsError>
where Octs: AsRef<[u8]> {
SvcParams::check_slice(octets.as_ref())?;
Ok(unsafe { Self::from_octets_unchecked(octets) })
}
/// Creates a new value from an octets sequence without checking.
///
/// # Safety
///
/// The caller has to ensure that `octets` contains a properly formatted
/// parameter sequence.
pub unsafe fn from_octets_unchecked(octets: Octs) -> Self {
SvcParams { octets }
}
}
impl SvcParams<[u8]> {
/// Creates a parameter sequence from an octets slice.
///
/// The method checks that `slice` contains a parameter sequence that is
/// correctly encoded in wire format. It does not check that the
/// individual values are correctly encoded. It also does not check for
/// any length limit.
pub fn from_slice(slice: &[u8]) -> Result<&Self, SvcParamsError> {
SvcParams::check_slice(slice)?;
Ok(unsafe { Self::from_slice_unchecked(slice) })
}
/// Creates a new value from a slice without checking.
///
/// # Safety
///
/// The caller has to ensure that `slice` contains a properly formatted
/// parameter sequence.
#[must_use]
pub unsafe fn from_slice_unchecked(slice: &[u8]) -> &Self {
// SAFETY: SvcParams has repr(transparent)
mem::transmute(slice)
}
/// Checks that a slice contains a correctly encoded parameters sequence.
fn check_slice(slice: &[u8]) -> Result<(), SvcParamsError> {
let mut parser = Parser::from_ref(slice);
let mut last_key = None;
while parser.remaining() > 0 {
let key = u16::parse(&mut parser)?;
if let Some(last_key) = last_key {
if key <= last_key {
Err(ParseError::form_error("unordered SVCB params"))?;
}
}
last_key = Some(key);
let len = u16::parse(&mut parser)?;
parser.advance(len.into())?;
}
Ok(())
}
}
impl<Octs> SvcParams<Octs> {
/// Creates a parameter sequence by constructing it from values.
///
/// The method expects a closure that receives an [`SvcParamsBuilder`]
/// which it should push all the required values to. Once it returns,
/// this builder is frozen into an `SvcParams` value and returned.
pub fn from_values<F>(op: F) -> Result<Self, PushError>
where
Octs: FromBuilder,
<Octs as FromBuilder>::Builder:
AsRef<[u8]> + OctetsBuilder + EmptyBuilder,
F: FnOnce(
&mut SvcParamsBuilder<<Octs as FromBuilder>::Builder>
) -> Result<(), PushError>,
{
let mut res = SvcParamsBuilder::empty();
op(&mut res)?;
res.freeze().map_err(Into::into)
}
}
impl<Octs: AsRef<[u8]>> SvcParams<Octs> {
/// Parses a parameter sequence from its wire format.
pub fn parse<'a, Src: Octets<Range<'a> = Octs> + ?Sized + 'a>(
parser: &mut Parser<'a, Src>
) -> Result<Self, ParseError> {
Self::from_octets(
parser.parse_octets(parser.remaining())?
).map_err(Into::into)
}
}
impl<Octs: ?Sized> SvcParams<Octs> {
/// Returns a reference to the underlying octets sequence.
pub fn as_octets(&self) -> &Octs {
&self.octets
}
}
impl<Octs: AsRef<[u8]> + ?Sized> SvcParams<Octs> {
/// Returns a slice of the underlying octets sequence.
pub fn as_slice(&self) -> &[u8] {
self.octets.as_ref()
}
/// Returns a parameter sequence atop a slice of this value’s octets.
pub fn for_slice(&self) -> &SvcParams<[u8]> {
unsafe { SvcParams::from_slice_unchecked(self.octets.as_ref()) }
}
/// Returns the length of the parameter sequence in octets.
pub fn len(&self) -> usize {
self.octets.as_ref().len()
}
/// Returns whether the parameters sequences is empty.
pub fn is_empty(&self) -> bool {
self.octets.as_ref().is_empty()
}
/// Returns the first value of type `Value`.
///
/// This method is intended to be used with value types implementing a
/// specific type. Since only one instance is allowed to be present,
/// this method also returns `None` if the first value fails parsing,
/// assuming that the value is unusable and should be ignored.
///
/// This may not be the correct behaviour in all cases. Please use
/// `self.iter::<Value>().next()` to get an optional parsing result.
pub fn first<'s, Value>(&'s self) -> Option<Value>
where
Octs: Octets,
Value: ParseSvcParamValue<'s, Octs>,
{
self.iter::<Value>().next().and_then(Result::ok)
}
/// Returns an iterator over all values accepted by `Value`.
pub fn iter<Value>(&self) -> ValueIter<Octs, Value> {
ValueIter::new(self.as_octets())
}
/// Returns an iterator over all values.
pub fn iter_all(&self) -> ValueIter<Octs, AllValues<Octs>>
where Octs: Sized {
self.iter()
}
/// Returns an iterator over all values in their raw form.
pub fn iter_raw(
&self
) -> impl Iterator<Item = UnknownSvcParam<Octs::Range<'_>>>
where Octs: Octets + Sized {
self.iter().map(|item| item.expect("parsing cannot have failed"))
}
/// Composes the wire-format of the parameter sequence.
pub fn compose<Target: OctetsBuilder + ?Sized>(
&self, target: &mut Target
) -> Result<(), Target::AppendError> {
target.append_slice(self.octets.as_ref())
}
}
//--- OctetsFrom
impl<SrcOcts, Octs> OctetsFrom<SvcParams<SrcOcts>> for SvcParams<Octs>
where Octs: OctetsFrom<SrcOcts> {
type Error = Octs::Error;
fn try_octets_from(
src: SvcParams<SrcOcts>
) -> Result<Self, Self::Error> {
Ok(unsafe {
SvcParams::from_octets_unchecked(src.octets.try_octets_into()?)
})
}
}
//--- PartialEq and Eq
impl<Octs, OtherOcts> PartialEq<SvcParams<OtherOcts>> for SvcParams<Octs>
where
Octs: AsRef<[u8]> + ?Sized,
OtherOcts: AsRef<[u8]> + ?Sized,
{
fn eq(&self, other: &SvcParams<OtherOcts>) -> bool {
self.as_slice().eq(other.as_slice())
}
}
impl<Octs: AsRef<[u8]> + ?Sized> Eq for SvcParams<Octs> { }
//--- Hash
impl<Octs: AsRef<[u8]> + ?Sized> hash::Hash for SvcParams<Octs> {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.as_slice().hash(state)
}
}
//--- PartialOrd Ord, and CanonicalOrd
impl<Octs, OtherOcts> PartialOrd<SvcParams<OtherOcts>> for SvcParams<Octs>
where
Octs: AsRef<[u8]> + ?Sized,
OtherOcts: AsRef<[u8]> + ?Sized,
{
fn partial_cmp(
&self, other: &SvcParams<OtherOcts>
) -> Option<cmp::Ordering> {
self.as_slice().partial_cmp(other.as_slice())
}
}
impl<Octs: AsRef<[u8]> + ?Sized> Ord for SvcParams<Octs> {
fn cmp(&self, other: &Self) -> cmp::Ordering {
self.as_slice().cmp(other.as_slice())
}
}
impl<Octs, OtherOcts> CanonicalOrd<SvcParams<OtherOcts>> for SvcParams<Octs>
where
Octs: AsRef<[u8]> + ?Sized,
OtherOcts: AsRef<[u8]> + ?Sized,
{
fn canonical_cmp(
&self, other: &SvcParams<OtherOcts>
) -> cmp::Ordering {
self.as_slice().cmp(other.as_slice())
}
}
//--- Display and Debug
impl<Octs: Octets + ?Sized> fmt::Display for SvcParams<Octs> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut parser = Parser::from_ref(self.as_slice());
let mut first = true;
while parser.remaining() > 0 {
let key = SvcParamKey::parse(
&mut parser
).expect("invalid SvcbParam");
let len = usize::from(
u16::parse(&mut parser).expect("invalid SvcParam")
);
let mut parser = parser.parse_parser(
len
).expect("invalid SvcParam");
if first {
first = false;
}
else {
f.write_str(" ")?;
}
write!(
f, "{}", super::value::AllValues::parse_any(key, &mut parser)
)?;
};
Ok(())
}
}
impl<Octs: Octets + ?Sized> fmt::Debug for SvcParams<Octs> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("SvcParams").field(
&format_args!("{}", self)
).finish()
}
}
//------------ ValueIter -----------------------------------------------------
/// An iterator over the values in a parameter sequence.
///
/// The iterator skips over those values that `Value` does not accept. It
/// returns the result of trying to parse the value into `Value`.
#[derive(Clone, Debug)]
pub struct ValueIter<'a, Octs: ?Sized, Value> {
parser: Parser<'a, Octs>,
marker: PhantomData<Value>,
}
impl<'a, Octs: AsRef<[u8]> + ?Sized, Value> ValueIter<'a, Octs, Value> {
fn new(octets: &'a Octs) -> Self {
ValueIter {
parser: Parser::from_ref(octets),
marker: PhantomData,
}
}
fn next_step(&mut self) -> Result<Option<Value>, ParseError>
where
Octs: Octets,
Value: ParseSvcParamValue<'a, Octs>,
{
let key = SvcParamKey::parse(&mut self.parser)?;
let len = usize::from(u16::parse(&mut self.parser)?);
let mut parser = self.parser.parse_parser(len)?;
let res = Value::parse_value(key, &mut parser)?;
if res.is_some() && parser.remaining() > 0 {
return Err(ParseError::form_error(
"trailing data in SVCB parameter",
));
}
Ok(res)
}
}
impl<'a, Octs, Value> Iterator for ValueIter<'a, Octs, Value>
where
Octs: Octets + ?Sized,
Value: ParseSvcParamValue<'a, Octs>,
{
type Item = Result<Value, ParseError>;
fn next(&mut self) -> Option<Self::Item> {
while self.parser.remaining() > 0 {
match self.next_step() {
Ok(Some(res)) => return Some(Ok(res)),
Ok(None) => { }
Err(err) => {
// Advance to end so we’ll return None from now on.
self.parser.advance_to_end();
return Some(Err(err));
}
}
}
None
}
}
//------------ SvcParamValue, ParseSvcParamValue, ComposeSvcParamValue -------
/// A type representing a service binding parameter value.
pub trait SvcParamValue {
/// Returns the parameter key of the value.
fn key(&self) -> SvcParamKey;
}
/// A service binding parameter value that can be parse from wire format.
pub trait ParseSvcParamValue<'a, Octs: ?Sized>: SvcParamValue + Sized {
/// Parse a parameter value from wire format.
///
/// The method should return `Ok(None)` if the type cannot parse values
/// with `key`. It should return an error if parsing fails.
fn parse_value(
key: SvcParamKey, parser: &mut Parser<'a, Octs>,
) -> Result<Option<Self>, ParseError>;
}
/// A service binding parameter value that can be composed into wire format.
///
/// All value types need to be able to calculate the length of their
/// wire format. This length needs to fit into a `u16`. It is the
/// responsibility of the value type to ensure that it will not grow too
/// large.
pub trait ComposeSvcParamValue: SvcParamValue {
/// Returns the length of the composed value.
fn compose_len(&self) -> u16;
/// Appends the wire format of the value to the end of `target`.
fn compose_value<Target: OctetsBuilder + ?Sized>(
&self, target: &mut Target,
) -> Result<(), Target::AppendError>;
}
//------------ UnknownSvcParam -----------------------------------------------
/// A service binding parameter value in its raw form.
///
/// This type can be used for any value type. It keeps the value’s data in
/// its raw wire format.
#[derive(Clone, Debug)]
pub struct UnknownSvcParam<Octs> {
/// The key of the value.
key: SvcParamKey,
/// The octets of the value.
value: Octs,
}
impl<Octs> UnknownSvcParam<Octs> {
/// Creates a new parameter value from the given key and data.
///
/// The function returns an error if `value` is longer than 65,535 octets.
pub fn new(key: SvcParamKey, value: Octs) -> Result<Self, LongSvcParam>
where Octs: AsRef<[u8]> {
LongSvcParam::check_len(value.as_ref().len())?;
Ok(unsafe { Self::new_unchecked(key, value) })
}
/// Creates a new SVCB parameter value without checking.
///
/// # Safety
///
/// The caller needs to make sure that `value` is not longer than
/// 65,535 octets.
pub unsafe fn new_unchecked(key: SvcParamKey, value: Octs) -> Self {
Self { key, value }
}
}
impl<Octs: AsRef<[u8]>> UnknownSvcParam<Octs> {
/// Parses a parameter value’s data from its wire format.
pub fn parse<'a, Src: Octets<Range<'a> = Octs> + ?Sized>(
key: SvcParamKey,
parser: &mut Parser<'a, Src>,
) -> Result<Self, ParseError> {
Self::new(
key, parser.parse_octets(parser.remaining())?
).map_err(Into::into)
}
/// Parses a full parameter from the wire format.
///
/// This function parses the key, length, and data of the parameter.
pub fn parse_param<'a, Src: Octets<Range<'a> = Octs> + ?Sized>(
parser: &mut Parser<'a, Src>,
) -> Result<Self, ParseError> {
let key = SvcParamKey::parse(parser)?;
let len = usize::from(u16::parse(parser)?);
let value = parser.parse_octets(len)?;
Ok(unsafe { Self::new_unchecked(key, value) })
}
/// Appends the wire format of the full parameter to the target.
///
/// This includes the key and length of the parameter.
pub fn compose_param<Target: OctetsBuilder + ?Sized>(
&self, target: &mut Target
) -> Result<(), Target::AppendError> {
self.key.compose(target)?;
self.compose_len().compose(target)?;
self.compose_value(target)
}
}
impl<Octs> UnknownSvcParam<Octs> {
/// Returns the key of the value.
pub fn key(&self) -> SvcParamKey {
self.key
}
/// Returns a reference to the value octets.
pub fn value(&self) -> &Octs {
&self.value
}
/// Returns a slice of the value.
pub fn as_slice(&self) -> &[u8]
where Octs: AsRef<[u8]> {
self.value.as_ref()
}
/// Returns a mutable slice of the value.
pub fn as_slice_mut(&mut self) -> &mut [u8]
where Octs: AsMut<[u8]> {
self.value.as_mut()
}
}
//--- AsRef and AsMut
impl<Octs> AsRef<Octs> for UnknownSvcParam<Octs> {
fn as_ref(&self) -> &Octs {
self.value()
}
}
impl<Octs: AsRef<[u8]>> AsRef<[u8]> for UnknownSvcParam<Octs> {
fn as_ref(&self) -> &[u8] {
self.as_slice()
}
}
impl<Octs: AsMut<[u8]>> AsMut<[u8]> for UnknownSvcParam<Octs> {
fn as_mut(&mut self) -> &mut [u8] {
self.as_slice_mut()
}
}
//--- PartialEq and Eq
impl<Octs, OtherOcts> PartialEq<UnknownSvcParam<OtherOcts>>
for UnknownSvcParam<Octs>
where
Octs: AsRef<[u8]>,
OtherOcts: AsRef<[u8]>,
{
fn eq(&self, other: &UnknownSvcParam<OtherOcts>) -> bool {
self.as_slice().eq(other.as_slice())
}
}
impl<Octs: AsRef<[u8]>> Eq for UnknownSvcParam<Octs> { }
//--- Hash
impl<Octs: AsRef<[u8]>> hash::Hash for UnknownSvcParam<Octs> {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.as_slice().hash(state)
}
}
//--- SvcParamValue et al.
impl<Octs> SvcParamValue for UnknownSvcParam<Octs> {
fn key(&self) -> SvcParamKey {
self.key
}
}
impl<'a, Octs: Octets + ?Sized> ParseSvcParamValue<'a, Octs>
for UnknownSvcParam<Octs::Range<'a>> {
fn parse_value(
key: SvcParamKey,
parser: &mut Parser<'a, Octs>,
) -> Result<Option<Self>, ParseError> {
Self::new(
key, parser.parse_octets(parser.remaining())?
).map(Some).map_err(Into::into)
}
}
impl<Octs: AsRef<[u8]>> ComposeSvcParamValue for UnknownSvcParam<Octs> {
fn compose_len(&self) -> u16 {
u16::try_from(self.as_slice().len()).expect("long value")
}
fn compose_value<Target: OctetsBuilder + ?Sized>(
&self, target: &mut Target,
) -> Result<(), Target::AppendError> {
target.append_slice(self.as_slice())
}
}
//--- Display and Debug
impl<Octs: AsRef<[u8]>> fmt::Display for UnknownSvcParam<Octs> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.key)?;
let slice = self.value.as_ref();
if !slice.is_empty() {
f.write_str("=")?;
for &ch in slice {
Symbol::from_octet(ch).fmt(f)?;
}
}
Ok(())
}
}
//------------ SvcParamsBuilder ----------------------------------------------
/// A builder for a service parameter sequence.
///
/// This type wraps an octets builder and allows appending parameter values.
/// You can create a new empty builder using the [`empty`][Self::empty]
/// function or copy an existing value through
/// [`from_params`][Self::from_params].
///
/// You can add additional values using the [`push`][Self::push] method.
/// There are also dedicated methods for all known value types. The builder
/// will make sure that each parameter key can only appear once. Thus,
/// pushing values may fail if a value is already present.
///
/// The builder also takes care of sorting the values into their correct
/// order. So you can push them in any order.
///
/// It only sorts the items when producing a frozen value via the
/// [`freeze`][Self::freeze] method.
#[derive(Clone, Debug)]
pub struct SvcParamsBuilder<Octs> {
/// The octets builder.
octets: Octs,
}
impl<Octs> SvcParamsBuilder<Octs> {
/// Creates an empty parameter builder.
#[must_use]
pub fn empty() -> Self
where Octs: EmptyBuilder {
Self { octets: Octs::empty() }
}
/// Creates a parameter builder from an existing parameter sequence.
///
/// The function creates a new empty builder and copies over the content
/// of `params`. It can fail if the octets builder is not capable of
/// providing enough space to hold the content of `params`.
pub fn from_params<Src: Octets + ?Sized>(
params: &SvcParams<Src>
) -> Result<Self, ShortBuf>
where Octs: AsRef<[u8]> + OctetsBuilder + EmptyBuilder {
let mut octets = Octs::empty();
for item in params.iter::<UnknownSvcParam<_>>() {
let item = item.expect("invalid SvcParams");
let start = u32::try_from(
octets.as_ref().len()
).map_err(|_| ShortBuf)?.checked_add(
u32::from(u32::COMPOSE_LEN)
).ok_or(ShortBuf)?;
octets.append_slice(
start.to_ne_bytes().as_ref()
).map_err(Into::into)?;
item.compose_param(&mut octets).map_err(Into::into)?;
}
octets.append_slice(
u32::MAX.to_be_bytes().as_ref()
).map_err(Into::into)?;
Ok(Self { octets })
}
/// Adds a new value to the builder.
///
/// The method will return an error if a value with this key is already
/// present or if there isn’t enough space left in the builder’s buffer.
pub fn push<Value: ComposeSvcParamValue + ?Sized>(
&mut self, value: &Value
) -> Result<(), PushError>
where Octs: OctetsBuilder + AsRef<[u8]> + AsMut<[u8]> {
self.push_raw(
value.key(), value.compose_len(), |octs| value.compose_value(octs)
)
}
pub(super) fn push_raw(
&mut self,
key: SvcParamKey,
value_len: u16,
value: impl FnOnce(&mut Octs) -> Result<(), Octs::AppendError>
) -> Result<(), PushError>
where Octs: OctetsBuilder + AsRef<[u8]> + AsMut<[u8]> {
// If octets is emtpy, we can just append ourselves and be done.
if self.octets.as_ref().is_empty() {
self.octets.append_slice(
&u32::from(u32::COMPOSE_LEN).to_ne_bytes()
)?;
key.compose(&mut self.octets)?;
value_len.compose(&mut self.octets)?;
(value)(&mut self.octets)?;
u32::MAX.compose(&mut self.octets)?;
return Ok(())
}
// Where will this value start? This also serves as a check whether
// we have become too long.
let start = u32::try_from(self.octets.as_ref().len()).map_err(|_|
PushError::ShortBuf
)?;
// Go over the values and find the predecessor and successor.
let mut pre = None;
let mut next = None;
let mut parser = Parser::from_ref(self.octets.as_ref());
// Skip the first pointer.
parser.advance(u32::COMPOSE_LEN.into()).unwrap();
while parser.remaining() > 0 {
let tmp_start = u32::try_from(parser.pos()).unwrap();
let tmp = UnknownSvcParam::parse_param(&mut parser).unwrap();
let tmp_end = u32::try_from(parser.pos()).unwrap();
let tmp_key = tmp.key();
match tmp_key.cmp(&key) {
Ordering::Equal => return Err(PushError::DuplicateKey),
Ordering::Less => {
match pre {
Some((key, _)) => {
if tmp_key > key {
pre = Some((tmp_key, tmp_end));
}
}
None => {
pre = Some((tmp_key, tmp_end))
}
}
}
Ordering::Greater => {
match next {
Some((key, _)) => {
if tmp_key < key {
next = Some((tmp_key, tmp_start));
}
}
None => {
next = Some((tmp_key, tmp_start))
}
}
}
}
parser.advance(u32::COMPOSE_LEN.into()).unwrap();
}
// Append the value.
key.compose(&mut self.octets)?;
value_len.compose(&mut self.octets)?;
(value)(&mut self.octets)?;
// Append the pointer to the next value. MAX means none.
self.octets.append_slice(
&next.map(|(_, pos)| pos).unwrap_or(u32::MAX).to_ne_bytes()
)?;
// Replace the predecessor’s point with our start. If there is no
// predecessor, we are the first item.
let pos = pre.map(|(_, pos)| {
// The u32 here was made from a usize so converting it back has to
// work.
usize::try_from(pos).unwrap()
}).unwrap_or(0);
self.octets.as_mut()[
pos..pos + usize::from(u32::COMPOSE_LEN)
].copy_from_slice(
&start.to_ne_bytes()
);
Ok(())
}
/// Freezes the builder to a parameter sequence.
///
/// Because the values may need to be resorted, this method actually
/// produces a new octets sequence. This is why it doesn’t consume the
/// builder and may fail if the target octet’s builder can’t provide
/// enough space.
pub fn freeze<Target>(
&self
) -> Result<
SvcParams<Target>,
<<Target as FromBuilder>::Builder as OctetsBuilder>::AppendError
>
where
Octs: AsRef<[u8]>,
Target: FromBuilder,
<Target as FromBuilder>::Builder: OctetsBuilder + EmptyBuilder
{
let mut target = <Target as FromBuilder>::Builder::empty();
if !self.octets.as_ref().is_empty() {
let mut parser = Parser::from_ref(self.octets.as_ref());
loop {
let pos = u32::from_ne_bytes(
Parse::parse(&mut parser).unwrap()
);
if pos == u32::MAX {
break;
}
let pos = usize::try_from(pos).unwrap();
parser.seek(pos).unwrap();
let param = UnknownSvcParam::parse_param(&mut parser).unwrap();
param.compose_param(&mut target)?;
}
}
Ok(unsafe {
SvcParams::from_octets_unchecked(
Target::from_builder(target)
)
})
}
}
//============ Error Types ===================================================
//------------ SvcParamsError -----------------------------------------------
/// An octets sequence was not a valid service bindings parameter sequence.
pub struct SvcParamsError(ParseError);
impl From<ShortInput> for SvcParamsError {
fn from(err: ShortInput) -> Self {
ParseError::from(err).into()
}
}
impl From<ParseError> for SvcParamsError {
fn from(err: ParseError) -> Self {
SvcParamsError(err)
}
}
impl From<SvcParamsError> for ParseError {
fn from(err: SvcParamsError) -> Self {
err.0
}
}
//------------ LongSvcParam --------------------------------------------------
/// The octets sequence to be used for record data is too long.
#[derive(Clone, Copy, Debug)]
pub struct LongSvcParam(());
impl LongSvcParam {
#[must_use]
pub fn as_str(self) -> &'static str {
"service parameter too long"
}
pub fn check_len(len: usize) -> Result<(), Self> {
if len > usize::from(u16::MAX) {
Err(LongSvcParam(()))
} else {
Ok(())
}
}
}
impl From<LongSvcParam> for ParseError {
fn from(src: LongSvcParam) -> Self {
ParseError::form_error(src.as_str())
}
}
impl fmt::Display for LongSvcParam {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(self.as_str())
}
}
#[cfg(feature = "std")]
impl std::error::Error for LongSvcParam {}
//------------ PushError -----------------------------------------------------
/// An error happened when pushing values to a parameters builder.
#[derive(Clone, Copy, Debug)]
#[non_exhaustive]
pub enum PushError {
/// A value with this key is already present.
DuplicateKey,
/// The octets builder does not have enough space to append the value.
ShortBuf,
}
impl<T: Into<ShortBuf>> From<T> for PushError {
fn from(_: T) -> Self {
PushError::ShortBuf
}
}
impl fmt::Display for PushError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
PushError::DuplicateKey => f.write_str("duplicate key"),
PushError::ShortBuf => ShortBuf.fmt(f)
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for PushError {}
//============ Tests =========================================================
#[cfg(test)]
mod test {
use super::*;
use super::super::value;
use octseq::array::Array;
type Octets512 = Array<512>;
type Params512 = SvcParams<Array<512>>;
type Builder512 = SvcParamsBuilder<Array<512>>;
fn octets512(slice: impl AsRef<[u8]>) -> Octets512 {
Octets512::try_from(slice.as_ref()).unwrap()
}
//--- Test vectors from the draft.
//
// We’re only testing the parameter portion here.
macro_rules! parse_compose {
( $rdata:expr, [ $( $value:expr )* ] ) => {
// parse test
let mut parser = Parser::from_ref($rdata.as_ref());
let params = SvcParams::parse(&mut parser).unwrap();
let mut param_iter = params.iter_all();
$(
assert_eq!(
param_iter.next().unwrap().unwrap(),
AllValues::<Octets512>::from($value)
);
)*
assert_eq!(None, param_iter.next());
// compose test
let built = Params512::from_values(|_builder| {
$(
_builder.push(&$value).unwrap();
)*
Ok(())
}).unwrap();
let mut buf = Octets512::new();
built.compose(&mut buf).unwrap();
assert_eq!($rdata.as_ref(), buf.as_ref());
}
}
#[test]
fn test_vectors_alias() {
parse_compose!(b"", []);
}
#[test]
fn test_vectors_port_only() {
parse_compose!(
b"\x00\x03\
\x00\x02\
\x00\x35",
[ value::Port::new(53) ]
);
}
#[test]
fn test_vectors_unknown_param() {
parse_compose!(
b"\x02\x9b\
\x00\x05\
\x68\x65\x6c\x6c\x6f",
[
UnknownSvcParam::new(
0x029b.into(),
octets512(b"hello")
).unwrap()
]
);
}
#[test]
fn test_vectors_unknown_param_quote() {
parse_compose!(
b"\x02\x9b\
\x00\x09\
\x68\x65\x6c\x6c\x6f\xd2\x71\x6f\x6f",
[
UnknownSvcParam::new(
0x029b.into(),
octets512(b"\x68\x65\x6c\x6c\x6f\xd2\x71\x6f\x6f"),
).unwrap()
]
);
}
#[test]
fn test_vectors_ipv6hint() {
use crate::base::net::Ipv6Addr;
use core::str::FromStr;
parse_compose!(
b"\x00\x06\
\x00\x20\
\x20\x01\x0d\xb8\x00\x00\x00\x00\
\x00\x00\x00\x00\x00\x00\x00\x01\
\x20\x01\x0d\xb8\x00\x00\x00\x00\
\x00\x00\x00\x00\x00\x53\x00\x01",
[
value::Ipv6Hint::<Octets512>::from_addrs([
Ipv6Addr::from_str("2001:db8::1").unwrap(),
Ipv6Addr::from_str("2001:db8::53:1").unwrap(),
]).unwrap()
]
);
}
#[test]
fn test_vectors_ipv6hint_v4mapped() {
use crate::base::net::Ipv6Addr;
use core::str::FromStr;
parse_compose!(
b"\x00\x06\
\x00\x10\
\x00\x00\x00\x00\x00\x00\x00\x00\
\x00\x00\xff\xff\xc6\x33\x64\x64",
[
value::Ipv6Hint::<Octets512>::from_addrs([
Ipv6Addr::from_str("::ffff:198.51.100.100").unwrap(),
]).unwrap()
]
);
}
// test vector key_sorting: see builder tests below
// test vector alpn_escape: see super::value::test
#[cfg(feature = "std")]
#[test]
fn test_representation() {
let mandatory = value::Mandatory::<Octets512>::from_keys(
[
SvcParamKey::ALPN,
SvcParamKey::IPV4HINT,
SvcParamKey::PRIVATE_RANGE_BEGIN.into()
].into_iter()
).unwrap();
assert_eq!(
"mandatory=alpn,ipv4hint,key65280",
format!("{}", mandatory)
);
let mut alpn_builder = value::AlpnBuilder::<Octets512>::empty();
alpn_builder.push("h2").unwrap();
alpn_builder.push("h3-19").unwrap();
assert_eq!(
"alpn=h2,h3-19",
format!("{}", alpn_builder.freeze())
);
assert_eq!("nodefaultalpn", format!("{}", value::NoDefaultAlpn));
assert_eq!(
"ech",
format!(
"{}",
value::Ech::from_octets(Octets512::new()).unwrap()
)
);
assert_eq!(
"ipv4hint=192.0.2.1,192.0.2.2",
format!(
"{}",
value::Ipv4Hint::<Octets512>::from_addrs(
[
[192, 0, 2, 1].into(), [192, 0, 2, 2].into()
]
).unwrap()
)
);
}
//--- Builder
#[test]
fn empty_builder() {
assert_eq!(
Builder512::empty().freeze::<Octets512>().unwrap().as_slice(),
b""
);
}
#[test]
fn one_value() {
let mut builder = Builder512::empty();
builder.push(&value::Port::new(53)).unwrap();
assert_eq!(
builder.freeze::<Octets512>().unwrap().as_slice(),
b"\x00\x03\x00\x02\x00\x35"
);
}
#[test]
fn three_values_in_order() {
let mut builder = Builder512::empty();
builder.push(
&UnknownSvcParam::new(1.into(), b"223").unwrap()
).unwrap();
builder.push(
&UnknownSvcParam::new(2.into(), b"224").unwrap()
).unwrap();
builder.push(
&UnknownSvcParam::new(8.into(), b"225").unwrap()
).unwrap();
assert_eq!(
builder.freeze::<Octets512>().unwrap().as_slice(),
b"\x00\x01\x00\x03223\
\x00\x02\x00\x03224\
\x00\x08\x00\x03225"
);
}
#[test]
fn three_values_out_of_order() {
let mut builder = Builder512::empty();
builder.push(
&UnknownSvcParam::new(1.into(), b"223").unwrap()
).unwrap();
builder.push(
&UnknownSvcParam::new(8.into(), b"225").unwrap()
).unwrap();
builder.push(
&UnknownSvcParam::new(2.into(), b"224").unwrap()
).unwrap();
assert_eq!(
builder.freeze::<Octets512>().unwrap().as_slice(),
b"\x00\x01\x00\x03223\
\x00\x02\x00\x03224\
\x00\x08\x00\x03225"
);
}
#[test]
fn three_values_with_collision() {
let mut builder = Builder512::empty();
builder.push(
&UnknownSvcParam::new(1.into(), b"223").unwrap()
).unwrap();
builder.push(
&UnknownSvcParam::new(8.into(), b"225").unwrap()
).unwrap();
assert!(
builder.push(
&UnknownSvcParam::new(8.into(), b"224").unwrap()
).is_err()
);
}
}