Refactored client binary.

crates/bgp_packet/src/traits.rs

@@ -0,0 +1,81 @@
+// Copyright 2021 Rayhaan Jaufeerally.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Implements high level abstractions for use in the BGP parser.
+
+use crate::constants::AddressFamilyIdentifier;
+use nom::error::ErrorKind;
+use nom::error::ParseError;
+use nom::IResult;
+
+// ParserContext contains information pertinent to configurations which affect
+// how message parsing is to be handled.
+#[derive(Debug, PartialEq, Clone)]
+pub struct ParserContext {
+    // Whether the peer is RFC6793 compliant.
+    pub four_octet_asn: Option<bool>,
+    // nlri_mode specifies if a parsed NLRI prefix should be a IPv4 or IPv6 address.
+    pub nlri_mode: Option<AddressFamilyIdentifier>,
+}
+
+impl ParserContext {
+    pub fn new() -> ParserContext {
+        ParserContext {
+            four_octet_asn: None,
+            nlri_mode: None,
+        }
+    }
+
+    pub fn four_octet_asn(mut self, v: bool) -> Self {
+        self.four_octet_asn = Some(v);
+        self
+    }
+
+    pub fn nlri_mode(mut self, v: AddressFamilyIdentifier) -> Self {
+        self.nlri_mode = Some(v);
+        self
+    }
+}
+
+// Custom error type for the parser.
+#[derive(Debug, PartialEq)]
+pub enum BGPParserError<I> {
+    CustomText(String),
+    Nom(I, ErrorKind),
+}
+
+impl<I> ParseError<I> for BGPParserError<I> {
+    fn from_error_kind(input: I, kind: ErrorKind) -> Self {
+        BGPParserError::Nom(input, kind)
+    }
+    fn append(_: I, _: ErrorKind, other: Self) -> Self {
+        other
+    }
+}
+
+pub trait WritablePacket {
+    /// to_wire serializes the packet to the wire format bytes.
+    fn to_wire(&self, ctx: &ParserContext) -> Result<Vec<u8>, &'static str>;
+    /// wire_len is the length of the message in bytes as would be on the wire.
+    fn wire_len(&self, ctx: &ParserContext) -> Result<u16, &'static str>;
+}
+
+pub trait ReadablePacket {
+    fn from_wire<'a>(
+        ctx: &ParserContext,
+        i: &'a [u8],
+    ) -> IResult<&'a [u8], Self, BGPParserError<&'a [u8]>>
+    where
+        Self: Sized;
+}