Write directly to the buffer instead of cursor.

1 files changed, 24 insertions, 22 deletions

diff --git a/src/vrrpv2.rs b/src/vrrpv2.rs
index 0845eee..748f266 100644
--- a/src/vrrpv2.rs
+++ b/src/vrrpv2.rs
@@ -1,4 +1,4 @@
-use std::io::{self, Cursor, Read, Write};
+use std::io::{self, Cursor, Read};
 use std::net::Ipv4Addr;
 
 /// A VRRP version 2 packet.
@@ -112,29 +112,31 @@ impl<T: AsRef<[u8]>> BytesReader for Cursor<T> {
 impl VRRPv2 {
     pub fn to_bytes(&self) -> Result<Vec<u8>, std::io::Error> {
         let sz = MIN_PACKET_SIZE + (self.ip_addrs.len() * 4);
-        let bytes: Vec<u8> = Vec::with_capacity(sz);
-        let mut wr = Cursor::new(bytes);
-        wr.write_all(
-            [
-                VERSION_TYPE,
-                self.virtual_router_id,
-                self.priority,
-                self.ip_addrs.len() as u8,
-                self.auth_type as u8,
-                self.advertisement_interval,
-                0x0, // checksum bits
-                0x0, // checksum bits
-            ]
-            .as_ref(),
-        )?;
-        for ip in self.ip_addrs.iter() {
-            wr.write_all(&ip.to_bits().to_be_bytes())?;
+        let mut bytes: Vec<u8> = Vec::with_capacity(sz);
+
+        // Write header
+        bytes.push(VERSION_TYPE);
+        bytes.push(self.virtual_router_id);
+        bytes.push(self.priority);
+        bytes.push(self.ip_addrs.len() as u8);
+        bytes.push(self.auth_type as u8);
+        bytes.push(self.advertisement_interval);
+        bytes.extend_from_slice(&[0, 0]); // Placeholder for checksum
+
+        // Write IP addresses
+        for ip in &self.ip_addrs {
+            bytes.extend_from_slice(&ip.to_bits().to_be_bytes());
         }
-        wr.write_all([0; 8].as_ref())?; // Authentication Data
-        let mut bytes = wr.into_inner();
-        // Calculate the checksum and set the respective bits
+
+        // Write auth data
+        bytes.extend_from_slice(&[0; 8]);
+
+        // Calculate and set checksum
         let cksum = checksum(&bytes);
-        [bytes[6], bytes[7]] = cksum.to_be_bytes();
+        let cksum_bytes = cksum.to_be_bytes();
+        bytes[6] = cksum_bytes[0];
+        bytes[7] = cksum_bytes[1];
+
         Ok(bytes)
     }
 }