feat: add socket address and simplify parse errors

crates/scion/src/address.rs

@@ -1,5 +1,3 @@
-use thiserror;
-
 mod asn;
 pub use asn::Asn;
 
@@ -10,21 +8,13 @@ mod ia;
 pub use ia::IsdAsn;
 
 mod service;
-pub use service::{ParseServiceAddressError, ServiceAddress};
+pub use service::ServiceAddress;
 
 mod host;
 pub use host::{Host, HostAddress, HostType};
 
-#[derive(Eq, PartialEq, Clone, Debug, thiserror::Error)]
-pub enum AddressParseError {
-    #[error("AS number out of range, expected at most 2^48 - 1")]
-    AsnOutOfRange,
-    #[error("AS string contains a part that is not a 2-byte HEX")]
-    InvalidAsnPart(String),
-    #[error("invalid AS number string (expected format xxxx:xxxx:xxxx, found {0})")]
-    InvalidAsnString(String),
-    #[error("ISD number not parsable as u16")]
-    InvalidIsdString(String),
-    #[error("invalid string (expected format d-xxxx:xxxx:xxxx, found {0})")]
-    InvalidIaString(String),
-}
+mod socket_address;
+pub use socket_address::{SocketAddr, SocketAddrSvc, SocketAddrV4, SocketAddrV6};
+
+mod error;
+pub use error::AddressParseError;

crates/scion/src/address/asn.rs

@@ -3,7 +3,7 @@ use std::{
     str::FromStr,
 };
 
-use super::AddressParseError;
+use super::{error::AddressKind, AddressParseError};
 
 /// A SCION autonomous system (AS) number
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
@@ -77,7 +77,7 @@ impl TryFrom<u64> for Asn {
 
     fn try_from(value: u64) -> Result<Self, Self::Error> {
         if value > Asn::MAX_VALUE {
-            Err(AddressParseError::AsnOutOfRange)
+            Err(AddressKind::Asn.into())
         } else {
             Ok(Asn(value))
         }
@@ -93,34 +93,28 @@ impl FromStr for Asn {
             return if bgp_asn <= u16::MAX.into() {
                 Ok(Self(bgp_asn))
             } else {
-                Err(Self::Err::InvalidAsnString(asn_string.into()))
+                Err(AddressKind::Asn.into())
             };
         }
 
-        let mut result = 0u64;
-        let mut n_parts = 0;
-
-        for asn_part in asn_string.split(':') {
-            n_parts += 1;
-            if n_parts > Asn::NUMBER_PARTS {
-                return Err(AddressParseError::InvalidAsnString(asn_string.into()));
-            }
-
-            match u16::from_str_radix(asn_part, 16) {
-                Ok(value) => {
-                    result <<= Asn::BITS_PER_PART;
-                    result |= u64::from(value);
-                }
-                Err(_) => return Err(AddressParseError::InvalidAsnPart(asn_string.into())),
-            }
-        }
+        let max_splits = usize::try_from(Asn::NUMBER_PARTS).expect("few parts");
+        let result = asn_string.splitn(max_splits, ':').try_fold(
+            (0u64, 0u32),
+            |(asn_value, n_parts), asn_part| {
+                u16::from_str_radix(asn_part, 16).map(|value| {
+                    (
+                        (asn_value << Asn::BITS_PER_PART) | u64::from(value),
+                        n_parts + 1,
+                    )
+                })
+            },
+        );
 
-        if n_parts != Asn::NUMBER_PARTS {
-            return Err(AddressParseError::InvalidAsnString(asn_string.into()));
+        if let Ok((value, Asn::NUMBER_PARTS)) = result {
+            Ok(Asn::new(value))
+        } else {
+            Err(AddressKind::Asn.into())
         }
-
-        // Can not panic as the result is at most 48 bits (exactly 3 parts, 16 bits each)
-        Ok(Asn::new(result))
     }
 }
 
@@ -148,7 +142,7 @@ mod tests {
         fn out_of_range() {
             assert_eq!(
                 Asn::try_from(Asn::MAX_VALUE + 1).unwrap_err(),
-                AddressParseError::AsnOutOfRange
+                AddressParseError(AddressKind::Asn)
             );
         }
     }
@@ -173,54 +167,25 @@ mod tests {
         test_success!(bgp_asn, "65535", Asn(65535));
 
         macro_rules! test_error {
-            ($name:ident, $input:expr, $expected:expr) => {
+            ($name:ident, $input:expr) => {
                 #[test]
                 fn $name() {
-                    assert_eq!(Asn::from_str($input).unwrap_err(), $expected);
+                    assert_eq!(
+                        Asn::from_str($input).unwrap_err(),
+                        AddressParseError(AddressKind::Asn)
+                    );
                 }
             };
         }
 
-        test_error!(
-            errs_large_decimal_format,
-            "65536",
-            AddressParseError::InvalidAsnString("65536".into())
-        );
-        test_error!(
-            errs_on_only_colon,
-            ":",
-            AddressParseError::InvalidAsnPart(":".into())
-        );
-        test_error!(
-            errs_extra_colon,
-            "0:0:0:",
-            AddressParseError::InvalidAsnString("0:0:0:".into())
-        );
-        test_error!(
-            errs_too_few,
-            "0:0",
-            AddressParseError::InvalidAsnString("0:0".into())
-        );
-        test_error!(
-            errs_invalid_part,
-            ":0:0",
-            AddressParseError::InvalidAsnPart(":0:0".into())
-        );
-        test_error!(
-            errs_out_of_range,
-            "10000:0:0",
-            AddressParseError::InvalidAsnPart("10000:0:0".into())
-        );
-        test_error!(
-            errs_out_of_range2,
-            "0:0:10000",
-            AddressParseError::InvalidAsnPart("0:0:10000".into())
-        );
-        test_error!(
-            errs_invalid_format,
-            "0:0x0:0",
-            AddressParseError::InvalidAsnPart("0:0x0:0".into())
-        );
+        test_error!(errs_large_decimal_format, "65536");
+        test_error!(errs_on_only_colon, ":");
+        test_error!(errs_extra_colon, "0:0:0:");
+        test_error!(errs_too_few, "0:0");
+        test_error!(errs_invalid_part, ":0:0");
+        test_error!(errs_out_of_range, "10000:0:0");
+        test_error!(errs_out_of_range2, "0:0:10000");
+        test_error!(errs_invalid_format, "0:0x0:0");
     }
 
     mod display {

crates/scion/src/address/error.rs

@@ -0,0 +1,41 @@
+use std::fmt::Display;
+
+/// An error which can be returned when parsing a SCION socket address, host address, or
+/// ISD identifier, AS number, or ISD-AS number.
+#[derive(Eq, PartialEq, Clone, Debug, thiserror::Error)]
+pub struct AddressParseError(pub(super) AddressKind);
+
+impl Display for AddressParseError {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let description = match self.0 {
+            AddressKind::Isd => "invalid ISD number syntax",
+            AddressKind::Asn => "invalid AS number syntax",
+            AddressKind::IsdAsn => "invalid ISD-AS number syntax",
+            AddressKind::Service => "invalid service address syntax",
+            AddressKind::SocketV4 => "invalid SCION-IPv4 socket address syntax",
+            AddressKind::SocketV6 => "invalid SCION-IPv6 socket address syntax",
+            AddressKind::SocketSvc => "invalid service socket address syntax",
+            AddressKind::Socket => "invalid socket address syntax",
+        };
+
+        fmt.write_str(description)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(super) enum AddressKind {
+    Isd,
+    Asn,
+    IsdAsn,
+    Service,
+    Socket,
+    SocketV4,
+    SocketV6,
+    SocketSvc,
+}
+
+impl From<AddressKind> for AddressParseError {
+    fn from(value: AddressKind) -> Self {
+        Self(value)
+    }
+}

crates/scion/src/address/ia.rs

@@ -5,10 +5,10 @@ use std::{
 
 use serde::Deserialize;
 
-use super::{AddressParseError, Asn, Isd};
+use super::{error::AddressKind, AddressParseError, Asn, Isd};
 
 /// The combined ISD and AS identifier of a SCION AS (sometimes abbreviated as IA).
-#[derive(Copy, Clone, Eq, PartialEq, Deserialize, Hash)]
+#[derive(Copy, Clone, Eq, PartialEq, Deserialize, Hash, PartialOrd, Ord)]
 #[serde(try_from = "String")]
 #[repr(transparent)]
 pub struct IsdAsn(pub u64);
@@ -73,16 +73,18 @@ impl FromStr for IsdAsn {
     fn from_str(string: &str) -> Result<Self, Self::Err> {
         let n_separators = string.chars().filter(|c| *c == '-').take(2).count();
         if n_separators != 1 {
-            return Err(Self::Err::InvalidIaString(string.into()));
+            return Err(AddressKind::IsdAsn.into());
         }
 
         let (isd_str, asn_str) = string
             .split_once('-')
             .expect("already checked that the string contains exactly one '-'");
-        Ok(IsdAsn::new(
-            Isd::from_str(isd_str)?,
-            Asn::from_str(asn_str)?,
-        ))
+
+        if let (Ok(isd), Ok(asn)) = (Isd::from_str(isd_str), Asn::from_str(asn_str)) {
+            Ok(IsdAsn::new(isd, asn))
+        } else {
+            Err(AddressKind::IsdAsn.into())
+        }
     }
 }
 
@@ -230,15 +232,15 @@ mod tests {
         fn invalid() {
             assert_eq!(
                 IsdAsn::from_str("a-0:0:1").unwrap_err(),
-                AddressParseError::InvalidIsdString("a".into())
+                AddressParseError(AddressKind::IsdAsn)
             );
         }
 
         #[test]
         fn invalid_parts() {
             assert_eq!(
                 IsdAsn::from_str("1-1-0:0:1").unwrap_err(),
-                AddressParseError::InvalidIaString("1-1-0:0:1".into())
+                AddressParseError(AddressKind::IsdAsn)
             );
         }
     }

crates/scion/src/address/isd.rs

@@ -3,7 +3,7 @@ use std::{
     str::FromStr,
 };
 
-use super::AddressParseError;
+use super::{error::AddressKind, AddressParseError};
 
 /// Identifier of a SCION Isolation Domain
 ///
@@ -55,11 +55,9 @@ impl FromStr for Isd {
     ///
     /// ISD 0 is parsed without any errors.
     fn from_str(string: &str) -> Result<Self, Self::Err> {
-        if let Ok(value) = u16::from_str(string) {
-            Ok(Isd::new(value))
-        } else {
-            Err(Self::Err::InvalidIsdString(string.into()))
-        }
+        u16::from_str(string)
+            .map(Isd::new)
+            .or(Err(AddressKind::Isd.into()))
     }
 }
 

crates/scion/src/address/service.rs

@@ -3,9 +3,7 @@ use std::{
     str::FromStr,
 };
 
-use thiserror;
-
-use super::{Host, HostAddress, HostType};
+use super::{error::AddressKind, AddressParseError, Host, HostAddress, HostType};
 
 /// A SCION service address.
 ///
@@ -17,7 +15,7 @@ use super::{Host, HostAddress, HostType};
 /// Service addresses can also be represented as strings, for example CS and CS_A
 /// both represent the anycast service address ServiceAddress::CONTROL. The
 /// corresponding multicast service address would be CS_M.
-#[derive(Eq, PartialEq, Copy, Clone, Debug)]
+#[derive(Eq, PartialEq, Copy, Clone, Debug, PartialOrd, Ord, Hash)]
 pub struct ServiceAddress(pub u16);
 
 impl ServiceAddress {
@@ -82,12 +80,8 @@ impl ServiceAddress {
     }
 }
 
-#[derive(Eq, PartialEq, Clone, Debug, thiserror::Error)]
-#[error("invalid service address string: {0}")]
-pub struct ParseServiceAddressError(String);
-
 impl FromStr for ServiceAddress {
-    type Err = ParseServiceAddressError;
+    type Err = AddressParseError;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let (service, suffix) = s.split_once('_').unwrap_or((s, "A"));
@@ -96,12 +90,12 @@ impl FromStr for ServiceAddress {
             "CS" => ServiceAddress::CONTROL,
             "DS" => ServiceAddress::DAEMON,
             "Wildcard" => ServiceAddress::WILDCARD,
-            _ => return Err(ParseServiceAddressError(s.into())),
+            _ => return Err(AddressKind::Service.into()),
         };
         match suffix {
             "A" => Ok(address),
             "M" => Ok(address.multicast()),
-            _ => Err(ParseServiceAddressError(s.into())),
+            _ => Err(AddressKind::Service.into()),
         }
     }
 }
@@ -187,7 +181,7 @@ mod tests {
                 fn $name() {
                     assert_eq!(
                         ServiceAddress::from_str($str).unwrap_err(),
-                        ParseServiceAddressError($str.into())
+                        AddressParseError(AddressKind::Service)
                     );
                 }
             };