1 files changed, 62 insertions, 0 deletions
diff --git a/third_party/rust/neqo-http3/src/frames/wtframe.rs b/third_party/rust/neqo-http3/src/frames/wtframe.rs
new file mode 100644
index 0000000000..deb7a026a0
--- /dev/null
+++ b/third_party/rust/neqo-http3/src/frames/wtframe.rs
@@ -0,0 +1,62 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::convert::TryFrom;
+
+use neqo_common::{Decoder, Encoder};
+
+use crate::{frames::reader::FrameDecoder, Error, Res};
+
+pub(crate) type WebTransportFrameType = u64;
+
+const WT_FRAME_CLOSE_SESSION: WebTransportFrameType = 0x2843;
+const WT_FRAME_CLOSE_MAX_MESSAGE_SIZE: u64 = 1024;
+
+#[derive(PartialEq, Eq, Debug)]
+pub enum WebTransportFrame {
+    CloseSession { error: u32, message: String },
+}
+
+impl WebTransportFrame {
+    pub fn encode(&self, enc: &mut Encoder) {
+        enc.encode_varint(WT_FRAME_CLOSE_SESSION);
+        let WebTransportFrame::CloseSession { error, message } = &self;
+        enc.encode_varint(4 + message.len() as u64);
+        enc.encode_uint(4, *error);
+        enc.encode(message.as_bytes());
+    }
+}
+
+impl FrameDecoder<WebTransportFrame> for WebTransportFrame {
+    fn decode(
+        frame_type: u64,
+        frame_len: u64,
+        data: Option<&[u8]>,
+    ) -> Res<Option<WebTransportFrame>> {
+        if let Some(payload) = data {
+            let mut dec = Decoder::from(payload);
+            if frame_type == WT_FRAME_CLOSE_SESSION {
+                if frame_len > WT_FRAME_CLOSE_MAX_MESSAGE_SIZE + 4 {
+                    return Err(Error::HttpMessageError);
+                }
+                let error =
+                    u32::try_from(dec.decode_uint(4).ok_or(Error::HttpMessageError)?).unwrap();
+                let Ok(message) = String::from_utf8(dec.decode_remainder().to_vec()) else {
+                    return Err(Error::HttpMessageError);
+                };
+                Ok(Some(WebTransportFrame::CloseSession { error, message }))
+            } else {
+                Ok(None)
+            }
+        } else {
+            Ok(None)
+        }
+    }
+
+    fn is_known_type(frame_type: u64) -> bool {
+        frame_type == WT_FRAME_CLOSE_SESSION
+    }
+}