[new/rdata] Add Srv

src/new/rdata/mod.rs

@@ -43,6 +43,7 @@
 //! - [`Mx`]
 //! - [`Txt`]
 //! - [`Rp`]
+//! - [`Srv`]
 //!
 //! Indirection types:
 //! - [`CName`]
@@ -115,6 +116,9 @@ pub use edns::{EdnsOptionsIter, Opt};
 mod rp;
 pub use rp::Rp;
 
+mod srv;
+pub use srv::Srv;
+
 mod dnssec;
 pub use dnssec::{
     DNSKey, DNSKeyFlags, DigestType, Ds, NSec, NSec3, NSec3Flags,
@@ -280,6 +284,9 @@ define_record_data! {
         /// Identification of the person/party responsible for this domain.
         Rp(Rp<N>) = RP,
 
+        /// The locations of services associated with this domain.
+        Srv(&'a Srv) = SRV,
+
         /// The IPv6 address of a host responsible for this domain.
         Aaaa(Aaaa) = AAAA,
 
@@ -331,6 +338,7 @@ impl<'a, N> RecordData<'a, N> {
             Self::Txt(r) => RecordData::Txt(r),
             Self::Rp(r) => RecordData::Rp(r.map_names(f)),
             Self::Aaaa(r) => RecordData::Aaaa(r),
+            Self::Srv(r) => RecordData::Srv(r),
             Self::DName(r) => RecordData::DName(r),
             Self::Opt(r) => RecordData::Opt(r),
             Self::Ds(r) => RecordData::Ds(r),
@@ -360,6 +368,7 @@ impl<'a, N> RecordData<'a, N> {
             Self::Txt(r) => RecordData::Txt(r),
             Self::Rp(r) => RecordData::Rp(r.map_names_by_ref(f)),
             Self::Aaaa(r) => RecordData::Aaaa(*r),
+            Self::Srv(r) => RecordData::Srv(r),
             Self::DName(r) => RecordData::DName(r),
             Self::Opt(r) => RecordData::Opt(r),
             Self::Ds(r) => RecordData::Ds(r),
@@ -395,6 +404,7 @@ impl<'a, N> RecordData<'a, N> {
             Self::Txt(r) => RecordData::Txt(copy_to_bump(*r, bump)),
             Self::Rp(r) => RecordData::Rp(r.clone()),
             Self::Aaaa(r) => RecordData::Aaaa(*r),
+            Self::Srv(r) => RecordData::Srv(copy_to_bump(*r, bump)),
             Self::DName(r) => RecordData::DName(copy_to_bump(*r, bump)),
             Self::Opt(r) => RecordData::Opt(copy_to_bump(*r, bump)),
             Self::Ds(r) => RecordData::Ds(copy_to_bump(*r, bump)),
@@ -450,6 +460,9 @@ impl<'a, N: SplitMessageBytes<'a>> ParseRecordData<'a> for RecordData<'a, N> {
             RType::AAAA => {
                 Aaaa::parse_bytes(&contents[start..]).map(Self::Aaaa)
             }
+            RType::SRV => {
+                <&Srv>::parse_bytes(&contents[start..]).map(Self::Srv)
+            }
             RType::DNAME => {
                 <&DName>::parse_bytes(&contents[start..]).map(Self::DName)
             }

src/new/rdata/srv.rs

@@ -0,0 +1,112 @@
+//! The SRV record data type.
+//!
+//! See [RFC 2782](https://datatracker.ietf.org/doc/html/rfc2782).
+
+use core::cmp::Ordering;
+
+use crate::new::base::build::{
+    AsBytes, BuildBytes, BuildInMessage, NameCompressor,
+};
+use crate::new::base::name::{CanonicalName, Name};
+use crate::new::base::wire::*;
+use crate::new::base::{
+    CanonicalRecordData, ParseRecordData, ParseRecordDataBytes, RType,
+};
+use crate::utils::dst::UnsizedCopy;
+
+//----------- Srv ------------------------------------------------------------
+
+/// The locations of services associated with this domain.
+//
+// TODO: Documentation.
+#[derive(
+    Debug,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    Hash,
+    AsBytes,
+    BuildBytes,
+    ParseBytesZC,
+    SplitBytesZC,
+    UnsizedCopy,
+)]
+#[repr(C)]
+pub struct Srv {
+    /// The priority of this host.
+    pub priority: U16,
+
+    /// The relative weight for selection of this host.
+    pub weight: U16,
+
+    /// The port number on which the service is provided.
+    pub port: U16,
+
+    /// The domain name of the target host.
+    pub name: Name,
+}
+
+//--- Canonical operations
+
+impl CanonicalRecordData for Srv {
+    fn build_canonical_bytes<'b>(
+        &self,
+        bytes: &'b mut [u8],
+    ) -> Result<&'b mut [u8], TruncationError> {
+        let bytes = self.priority.build_bytes(bytes)?;
+        let bytes = self.weight.build_bytes(bytes)?;
+        let bytes = self.port.build_bytes(bytes)?;
+        let bytes = self.name.build_lowercased_bytes(bytes)?;
+        Ok(bytes)
+    }
+
+    fn cmp_canonical(&self, other: &Self) -> Ordering {
+        // `Srv` uses canonical comparisons by default.
+        self.cmp(other)
+    }
+}
+
+//--- Building into DNS messages
+
+impl BuildInMessage for Srv {
+    fn build_in_message(
+        &self,
+        contents: &mut [u8],
+        start: usize,
+        _compressor: &mut NameCompressor,
+    ) -> Result<usize, TruncationError> {
+        let bytes = self.as_bytes();
+        let end = start + bytes.len();
+        contents
+            .get_mut(start..end)
+            .ok_or(TruncationError)?
+            .copy_from_slice(bytes);
+        Ok(end)
+    }
+}
+
+//--- Cloning
+
+#[cfg(feature = "alloc")]
+impl Clone for alloc::boxed::Box<Srv> {
+    fn clone(&self) -> Self {
+        (*self).unsized_copy_into()
+    }
+}
+
+//--- Parsing record data
+
+impl<'a> ParseRecordData<'a> for &'a Srv {}
+
+impl<'a> ParseRecordDataBytes<'a> for &'a Srv {
+    fn parse_record_data_bytes(
+        bytes: &'a [u8],
+        rtype: RType,
+    ) -> Result<Self, ParseError> {
+        match rtype {
+            RType::SRV => Self::parse_bytes(bytes),
+            _ => Err(ParseError),
+        }
+    }
+}