feat(scmp): add enums for error and info messages

crates/scion-proto/src/packet/scmp.rs

@@ -6,6 +6,7 @@ use super::{
     error::ScmpEncodeError,
     FlowId,
     InadequateBufferSize,
+    MessageChecksum,
     ScionHeaders,
     ScionPacket,
     ScionPacketRaw,
@@ -14,7 +15,14 @@ use crate::{
     address::ScionAddr,
     packet::ByEndpoint,
     path::{DataplanePath, Path},
-    scmp::{ScmpDecodeError, ScmpMessage, ScmpTracerouteRequest, ScmpType, SCMP_PROTOCOL_NUMBER},
+    scmp::{
+        ScmpDecodeError,
+        ScmpMessage,
+        ScmpMessageBase,
+        ScmpTracerouteRequest,
+        ScmpType,
+        SCMP_PROTOCOL_NUMBER,
+    },
     wire_encoding::{WireDecode, WireEncodeVec},
 };
 
@@ -27,11 +35,14 @@ pub struct ScionPacketScmp {
     pub message: ScmpMessage,
 }
 
-impl ScionPacketScmp {
-    /// Returns the SCMP message type.
-    pub fn get_type(&self) -> ScmpType {
+impl ScmpMessageBase for ScionPacketScmp {
+    fn get_type(&self) -> ScmpType {
         self.message.get_type()
     }
+
+    fn code(&self) -> u8 {
+        self.message.code()
+    }
 }
 
 impl ScionPacketScmp {

crates/scion-proto/src/scmp.rs

@@ -23,6 +23,16 @@ pub trait ScmpMessageBase {
     fn code(&self) -> u8 {
         0
     }
+
+    /// Returns true iff `self` is an error message.
+    fn is_error(&self) -> bool {
+        self.get_type().is_error()
+    }
+
+    /// Returns true iff `self` is an informational message.
+    fn is_informational(&self) -> bool {
+        self.get_type().is_informational()
+    }
 }
 
 /// SCION protocol number for SCMP.