Use constants.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/vrrpv2.rs b/src/vrrpv2.rs
index fa41696..bcb2315 100644
--- a/src/vrrpv2.rs
+++ b/src/vrrpv2.rs
@@ -25,6 +25,11 @@ use std::net::Ipv4Addr;
 /// |                     Authentication Data (2)                   |
 /// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 /// ```
+
+const VERSION: u8 = 2;
+const TYPE: u8 = 1;
+const VERSION_TYPE: u8 = (VERSION << 4) | TYPE; // 0x21
+
 #[derive(Debug, PartialEq)]
 pub struct VRRPv2 {
     pub virtual_router_id: u8,
@@ -106,7 +111,7 @@ impl VRRPv2 {
         let mut wr = Cursor::new(bytes);
         wr.write_all(
             [
-                0x21,
+                VERSION_TYPE,
                 self.virtual_router_id,
                 self.priority,
                 self.ip_addrs.len() as u8,
@@ -132,8 +137,8 @@ impl VRRPv2 {
 fn parse(bytes: &[u8]) -> Result<VRRPv2, VRRPv2Error> {
     let mut rdr = Cursor::new(bytes);
     match rdr.read_u8()? {
-        i if (i & 0xF) != 1 => return Err(VRRPv2Error::InvalidType),
-        i if (i >> 4) != 2 => return Err(VRRPv2Error::InvalidVersion),
+        i if (i & 0xF) != TYPE => return Err(VRRPv2Error::InvalidType),
+        i if (i >> 4) != VERSION => return Err(VRRPv2Error::InvalidVersion),
         _ => {}
     };
     let virtual_router_id = rdr.read_u8()?;