Encode And Parse Version Information Transport Parameter

hawkinsw · hawkinsw · commit d11097cad58b · 2025-10-15T15:12:14.000-04:00
Does not (yet!) incorporate parsed Version Information Transport Parameter
into version negotiotiation.
diff --git a/quiche/src/lib.rs b/quiche/src/lib.rs
@@ -8909,6 +8909,8 @@ pub struct TransportParams {
     pub retry_source_connection_id: Option<ConnectionId<'static>>,
     /// DATAGRAM frame extension parameter, if any.
     pub max_datagram_frame_size: Option<u64>,
+    /// Information for version negotiation, if any.
+    pub version_information: Option<(u32, Option<Vec<u32>>)>,
     /// Unknown peer transport parameters and values, if any.
     pub unknown_params: Option<UnknownTransportParameters>,
     // pub preferred_address: ...,
@@ -8934,6 +8936,7 @@ impl Default for TransportParams {
             initial_source_connection_id: None,
             retry_source_connection_id: None,
             max_datagram_frame_size: None,
+            version_information: None,
             unknown_params: Default::default(),
         }
     }
@@ -9094,6 +9097,18 @@ impl TransportParams {
                     tp.max_datagram_frame_size = Some(val.get_varint()?);
                 },
 
+                0x0011 => {
+                    let chosen_version = val.get_u32()?;
+
+                    let mut available_versions: Option<Vec<u32>> = None;
+                    while val.off() < val.len() {
+                        let version = val.get_u32()?;
+                        available_versions.get_or_insert_default().push(version);
+                    }
+                    tp.version_information =
+                        Some((chosen_version, available_versions));
+                },
+
                 // Track unknown transport parameters specially.
                 unknown_tp_id => {
                     if let Some(unknown_params) = &mut tp.unknown_params {
@@ -9279,6 +9294,20 @@ impl TransportParams {
             b.put_varint(max_datagram_frame_size)?;
         }
 
+        if let Some((left, right)) = &tp.version_information {
+            TransportParams::encode_param(
+                &mut b,
+                0x0011,
+                4 + 4 * right.as_ref().map(|r| r.len()).unwrap_or_default(),
+            )?;
+            b.put_u32(*left)?;
+            if let Some(available_versions) = &right {
+                for available_version in available_versions {
+                    b.put_u32(*available_version)?;
+                }
+            }
+        }
+
         let out_len = b.off();
 
         Ok(&mut out[..out_len])
diff --git a/quiche/src/tests.rs b/quiche/src/tests.rs
@@ -51,12 +51,13 @@ fn transport_params() {
         initial_source_connection_id: Some(b"woot woot".to_vec().into()),
         retry_source_connection_id: Some(b"retry".to_vec().into()),
         max_datagram_frame_size: Some(32),
+        version_information: Some((72, Some(vec![81, 5, 9]))),
         unknown_params: Default::default(),
     };
 
     let mut raw_params = [42; 256];
     let raw_params = TransportParams::encode(&tp, true, &mut raw_params).unwrap();
-    assert_eq!(raw_params.len(), 94);
+    assert_eq!(raw_params.len(), 112);
 
     let new_tp = TransportParams::decode(raw_params, false, None).unwrap();
 
@@ -81,13 +82,14 @@ fn transport_params() {
         initial_source_connection_id: Some(b"woot woot".to_vec().into()),
         retry_source_connection_id: None,
         max_datagram_frame_size: Some(32),
+        version_information: Some((72, None)),
         unknown_params: Default::default(),
     };
 
     let mut raw_params = [42; 256];
     let raw_params =
         TransportParams::encode(&tp, false, &mut raw_params).unwrap();
-    assert_eq!(raw_params.len(), 69);
+    assert_eq!(raw_params.len(), 75);
 
     let new_tp = TransportParams::decode(raw_params, true, None).unwrap();
 
