WIP: Support variable-length connection IDs

quinn-rs · May 23, 2024 · 7479835 · 7479835
1 parent 1eb96dc
commit 7479835
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Showing 5 changed files with 6 additions and 21 deletions.
diff --git a/quinn-proto/src/cid_generator.rs b/quinn-proto/src/cid_generator.rs
@@ -24,8 +24,6 @@ pub trait ConnectionIdGenerator: Send + Sync + ConnectionIdParser {
         Ok(())
     }
 
-    /// Returns the length of a CID for connections created by this generator
-    fn cid_len(&self) -> usize;
     /// Returns the lifetime of generated Connection IDs
     ///
     /// Connection IDs will be retired after the returned `Duration`, if any. Assumed to be constant.
@@ -90,11 +88,6 @@ impl ConnectionIdGenerator for RandomConnectionIdGenerator {
         ConnectionId::new(&bytes_arr[..self.cid_len])
     }
 
-    /// Provide the length of dst_cid in short header packet
-    fn cid_len(&self) -> usize {
-        self.cid_len
-    }
-
     fn cid_lifetime(&self) -> Option<Duration> {
         self.lifetime
     }
@@ -171,10 +164,6 @@ impl ConnectionIdGenerator for HashedConnectionIdGenerator {
         }
     }
 
-    fn cid_len(&self) -> usize {
-        HASHED_CID_LEN
-    }
-
     fn cid_lifetime(&self) -> Option<Duration> {
         self.lifetime
     }

diff --git a/quinn-proto/src/config.rs b/quinn-proto/src/config.rs
@@ -620,7 +620,7 @@ pub struct EndpointConfig {
     ///
     /// Create a cid generator for local cid in Endpoint struct
     pub(crate) connection_id_generator_factory:
-        Arc<dyn Fn() -> Arc<dyn ConnectionIdGenerator> + Send + Sync>,
+        Option<Arc<dyn Fn() -> Arc<dyn ConnectionIdGenerator> + Send + Sync>>,
     pub(crate) supported_versions: Vec<u32>,
     pub(crate) grease_quic_bit: bool,
     /// Minimum interval between outgoing stateless reset packets
@@ -635,7 +635,7 @@ impl EndpointConfig {
         Self {
             reset_key,
             max_udp_payload_size: (1500u32 - 28).into(), // Ethernet MTU minus IP + UDP headers
-            connection_id_generator_factory: Arc::new(cid_factory),
+            connection_id_generator_factory: Some(Arc::new(cid_factory)),
             supported_versions: DEFAULT_SUPPORTED_VERSIONS.to_vec(),
             grease_quic_bit: true,
             min_reset_interval: Duration::from_millis(20),

diff --git a/quinn-proto/src/connection/mod.rs b/quinn-proto/src/connection/mod.rs
@@ -253,7 +253,7 @@ impl Connection {
         remote: SocketAddr,
         local_ip: Option<IpAddr>,
         crypto: Box<dyn crypto::Session>,
-        cid_gen: Arc<dyn ConnectionIdGenerator>,
+        cid_gen: Option<Arc<dyn ConnectionIdGenerator>>,
         now: Instant,
         version: u32,
         allow_mtud: bool,

diff --git a/quinn-proto/src/endpoint.rs b/quinn-proto/src/endpoint.rs
@@ -676,10 +676,7 @@ impl Endpoint {
         // bytes. If this is a Retry packet, then the length must instead match our usual CID
         // length. If we ever issue non-Retry address validation tokens via `NEW_TOKEN`, then we'll
         // also need to validate CID length for those after decoding the token.
-        if header.dst_cid.len() < 8
-            && (!header.token_pos.is_empty()
-                && header.dst_cid.len() != self.local_cid_generator.cid_len())
-        {
+        if header.dst_cid.len() < 8 && !header.token_pos.is_empty() {
             debug!(
                 "rejecting connection due to invalid DCID length {}",
                 header.dst_cid.len()

diff --git a/quinn-proto/src/transport_parameters.rs b/quinn-proto/src/transport_parameters.rs
@@ -15,7 +15,6 @@ use bytes::{Buf, BufMut};
 use thiserror::Error;
 
 use crate::{
-    cid_generator::ConnectionIdGenerator,
     cid_queue::CidQueue,
     coding::{BufExt, BufMutExt, UnexpectedEnd},
     config::{EndpointConfig, ServerConfig, TransportConfig},
@@ -132,7 +131,7 @@ impl TransportParameters {
     pub(crate) fn new(
         config: &TransportConfig,
         endpoint_config: &EndpointConfig,
-        cid_gen: &dyn ConnectionIdGenerator,
+        use_cids: bool,
         initial_src_cid: ConnectionId,
         server_config: Option<&ServerConfig>,
     ) -> Self {
@@ -147,7 +146,7 @@ impl TransportParameters {
             max_udp_payload_size: endpoint_config.max_udp_payload_size,
             max_idle_timeout: config.max_idle_timeout.unwrap_or(VarInt(0)),
             disable_active_migration: server_config.map_or(false, |c| !c.migration),
-            active_connection_id_limit: if cid_gen.cid_len() == 0 {
+            active_connection_id_limit: if !use_cids {
                 2 // i.e. default, i.e. unsent
             } else {
                 CidQueue::LEN as u32