Not reparsing version (#39)

Co-authored-by: Michael Mileusnich <[email protected]>

Author: mikemiles-dev

RELEASES.md

@@ -1,4 +1,5 @@
 # 0.2.3
+  * Small performance improvement by not parsing netflow version twice each packet.
   * General Code cleanup for field_types and DataNumbers.
 
 # 0.2.2

src/lib.rs

@@ -160,13 +160,13 @@ impl NetflowParser {
         packet: &'a [u8],
     ) -> Result<ParsedNetflow, Box<dyn std::error::Error>> {
         match NetflowHeader::parse_be(packet) {
-            Ok((_, netflow_header)) if netflow_header.version == 5 => V5::parse_bytes(packet),
-            Ok((_, netflow_header)) if netflow_header.version == 7 => V7::parse_bytes(packet),
-            Ok((_, netflow_header)) if netflow_header.version == 9 => {
-                self.v9_parser.parse_bytes(packet)
+            Ok((i, netflow_header)) if netflow_header.version == 5 => V5::parse_bytes(i),
+            Ok((i, netflow_header)) if netflow_header.version == 7 => V7::parse_bytes(i),
+            Ok((i, netflow_header)) if netflow_header.version == 9 => {
+                self.v9_parser.parse_bytes(i)
             }
-            Ok((_, netflow_header)) if netflow_header.version == 10 => {
-                self.ipfix_parser.parse_bytes(packet)
+            Ok((i, netflow_header)) if netflow_header.version == 10 => {
+                self.ipfix_parser.parse_bytes(i)
             }
             _ => Err("Not Supported".to_string().into()),
         }

src/static_versions/v5.rs

@@ -38,6 +38,7 @@ impl NetflowByteParserStatic for V5 {
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Serialize, Nom)]
 pub struct Header {
     /// NetFlow export format version number
+    #[nom(Value = "5")]
     pub version: u16,
     /// Number of flows exported in this packet (1-30)
     pub count: u16,

src/static_versions/v7.rs

@@ -38,6 +38,7 @@ impl NetflowByteParserStatic for V7 {
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Nom, Serialize)]
 pub struct Header {
     /// NetFlow export format version number
+    #[nom(Value = "7")]
     pub version: u16,
     /// Number of flows exported in this flow frame (protocol data unit, or PDU)
     pub count: u16,

src/variable_versions/common.rs

@@ -8,6 +8,7 @@ use nom::IResult;
 use nom_derive::*;
 use serde::Serialize;
 
+use std::convert::Into;
 use std::net::{Ipv4Addr, Ipv6Addr};
 use std::time::Duration;
 
@@ -25,11 +26,6 @@ pub enum DataNumber {
 
 /// Convert into usize, mainly for serialization purposes
 impl DataNumber {
-    pub fn get_value(self) -> usize {
-        let result: usize = self.into();
-        result
-    }
-
     /// Parse bytes into DataNumber Type
     pub fn parse(i: &[u8], field_length: u16, signed: bool) -> IResult<&[u8], DataNumber> {
         match field_length {
@@ -78,28 +74,36 @@ impl DataNumber {
                 let (i, data_number) = DataNumber::parse(remaining, field_length, false)?;
                 (
                     i,
-                    FieldValue::Duration(Duration::from_secs(data_number.get_value() as u64)),
+                    FieldValue::Duration(Duration::from_secs(
+                        <DataNumber as Into<usize>>::into(data_number) as u64,
+                    )),
                 )
             }
             FieldDataType::DurationMillis => {
                 let (i, data_number) = DataNumber::parse(remaining, field_length, false)?;
                 (
                     i,
-                    FieldValue::Duration(Duration::from_millis(data_number.get_value() as u64)),
+                    FieldValue::Duration(Duration::from_millis(
+                        <DataNumber as Into<usize>>::into(data_number) as u64,
+                    )),
                 )
             }
             FieldDataType::DurationMicros => {
                 let (i, data_number) = DataNumber::parse(remaining, field_length, false)?;
                 (
                     i,
-                    FieldValue::Duration(Duration::from_micros(data_number.get_value() as u64)),
+                    FieldValue::Duration(Duration::from_micros(
+                        <DataNumber as Into<usize>>::into(data_number) as u64,
+                    )),
                 )
             }
             FieldDataType::DurationNanos => {
                 let (i, data_number) = DataNumber::parse(remaining, field_length, false)?;
                 (
                     i,
-                    FieldValue::Duration(Duration::from_nanos(data_number.get_value() as u64)),
+                    FieldValue::Duration(Duration::from_nanos(
+                        <DataNumber as Into<usize>>::into(data_number) as u64,
+                    )),
                 )
             }
             FieldDataType::ProtocolType => {

src/variable_versions/ipfix.rs

@@ -46,6 +46,7 @@ pub struct IPFix {
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Serialize, Nom)]
 pub struct Header {
     /// Version of Flow Record format that is exported in this message. The value of this field is 0x000a for the current version, incrementing by one the version that is used in the NetFlow services export version 9
+    #[nom(Value = "10")]
     pub version: u16,
     /// Total length of the IPFIX Message, which is measured in octets, including Message Header and Sets.
     pub length: u16,

src/variable_versions/v9.rs

@@ -70,6 +70,7 @@ fn parse_flowsets<'a>(
 #[derive(Debug, PartialEq, Clone, Copy, Serialize, Nom)]
 pub struct Header {
     /// The version of NetFlow records exported in this packet; for Version 9, this value is 9
+    #[nom(Value = "9")]
     pub version: u16,
     /// Number of FlowSet records (both template and data) contained within this packet
     pub count: u16,