Fix: don't use mutable borrows when we don't need it

2 files changed, 5 insertions, 5 deletions

diff --git a/src/eth.rs b/src/eth.rs
index 5518e9a..cf1f0a9 100644
--- a/src/eth.rs
+++ b/src/eth.rs
@@ -6,11 +6,11 @@ use crate::error::ParseError;
 
 /// A valid Ethernet Header
 #[derive(Debug)]
-pub struct Header<'a>(&'a mut [u8]);
+pub struct Header<'a>(&'a [u8]);
 
 impl<'a> Header<'a> {
     /// Parse a buffer and create a Ethernet Header from it.
-    pub fn with_buffer(buffer: &'a mut [u8]) -> Result<Self, ParseError> {
+    pub fn with_buffer(buffer: &'a [u8]) -> Result<Self, ParseError> {
         if buffer.len() < 14 {
             return Err(ParseError::BufferTooSmall(buffer.len()));
         }
diff --git a/src/packet.rs b/src/packet.rs
index 6cefe64..f45000b 100644
--- a/src/packet.rs
+++ b/src/packet.rs
@@ -6,7 +6,7 @@ use std::slice;
 pub const PPPOE_DISCOVERY: u16 = 0x8863;
 pub const PPPOE_SESSION: u16 = 0x8864;
 
-fn ensure_minimal_buffer_size(buffer: &mut [u8]) -> Result<(), ParseError> {
+fn ensure_minimal_buffer_size(buffer: &[u8]) -> Result<(), ParseError> {
     // minimal eth + pppoe header size
     if buffer.len() < 20 {
         return Err(ParseError::BufferTooSmall(buffer.len()));
@@ -26,9 +26,9 @@ impl<'a> Packet<'a> {
     ///
     /// The buffer is expected contain a valid Ethernet Packet (with an ethertype for PPPoE) and a
     /// PPPoE Packet.  Therefore the buffer must be greater than 20 bytes.
-    pub fn with_buffer(buffer: &'a mut [u8]) -> Result<Self, Error> {
+    pub fn with_buffer(buffer: &'a [u8]) -> Result<Self, Error> {
         ensure_minimal_buffer_size(buffer)?;
-        let (eth_buf, pppoe_buf) = buffer.split_at_mut(14);
+        let (eth_buf, pppoe_buf) = buffer.split_at(14);
 
         Ok(Self {
             ethernet: eth::Header::with_buffer(eth_buf)?,