fix panics

azalea-protocol/src/packets/game/clientbound_recipe_packet.rs

@@ -1,8 +1,6 @@
-use azalea_buf::{BufReadError, McBuf};
+use azalea_buf::McBuf;
-use azalea_buf::{McBufReadable, McBufWritable, Readable, Writable};
 use azalea_core::ResourceLocation;
 use packet_macros::ClientboundGamePacket;
-use std::io::{Read, Write};
 
 #[derive(Clone, Debug, McBuf, ClientboundGamePacket)]
 pub struct ClientboundRecipePacket {
@@ -27,27 +25,9 @@ pub struct RecipeBookSettings {
     pub smoker_filtering_craftable: bool,
 }
 
-#[derive(Clone, Debug, Copy)]
+#[derive(Clone, Debug, Copy, McBuf)]
 pub enum State {
     Init = 0,
     Add = 1,
     Remove = 2,
 }
-
-impl McBufWritable for State {
-    fn write_into(&self, buf: &mut impl Write) -> Result<(), std::io::Error> {
-        buf.write_varint(*self as i32)?;
-        Ok(())
-    }
-}
-impl McBufReadable for State {
-    fn read_from(buf: &mut impl Read) -> Result<Self, BufReadError> {
-        let state = buf.read_varint()?;
-        Ok(match state {
-            0 => State::Init,
-            1 => State::Add,
-            2 => State::Remove,
-            _ => panic!("Invalid state: {}", state),
-        })
-    }
-}

azalea-protocol/src/read.rs

@@ -50,6 +50,8 @@ pub enum FrameSplitterError {
         #[from]
         source: std::io::Error,
     },
+    #[error("Packet is longer than {max} bytes (is {size})")]
+    BadLength { max: u32, size: u32 },
 }
 
 async fn frame_splitter<R: ?Sized>(mut stream: &mut R) -> Result<Vec<u8>, FrameSplitterError>
@@ -57,7 +59,16 @@ where
     R: AsyncRead + std::marker::Unpin + std::marker::Send,
 {
     // Packet Length
-    let length = read_varint_async(&mut stream).await?;
+    let length = read_varint_async(&mut stream).await? as u32;
+
+    let max_length: u32 = 2u32.pow(20u32); // 1mb, arbitrary
+    if length > max_length {
+        // minecraft *probably* won't send packets bigger than this
+        return Err(FrameSplitterError::BadLength {
+            max: max_length,
+            size: length,
+        });
+    }
 
     let mut buf = vec![0; length as usize];
     stream.read_exact(&mut buf).await?;