feat: Option for no zero-len CIDs for client

neqo-bin/src/client/http09.rs

@@ -20,8 +20,8 @@ use std::{
 use neqo_common::{event::Provider, qdebug, qinfo, qwarn, Datagram};
 use neqo_crypto::{AuthenticationStatus, ResumptionToken};
 use neqo_transport::{
-    CloseReason, Connection, ConnectionEvent, EmptyConnectionIdGenerator, Error, Output, State,
-    StreamId, StreamType,
+    CloseReason, Connection, ConnectionEvent, ConnectionIdGenerator, EmptyConnectionIdGenerator,
+    Error, Output, RandomConnectionIdGenerator, State, StreamId, StreamType,
 };
 use url::Url;
 
@@ -133,11 +133,17 @@ pub fn create_client(
         "hq-29" | "hq-30" | "hq-31" | "hq-32" => args.shared.alpn.as_str(),
         _ => "hq-interop",
     };
-
+    let cid_generator: Rc<RefCell<dyn ConnectionIdGenerator>> = if args.cid_len == 0 {
+        Rc::new(RefCell::new(EmptyConnectionIdGenerator::default()))
+    } else {
+        Rc::new(RefCell::new(RandomConnectionIdGenerator::new(
+            args.cid_len.into(),
+        )))
+    };
     let mut client = Connection::new_client(
         hostname,
         &[alpn],
-        Rc::new(RefCell::new(EmptyConnectionIdGenerator::default())),
+        cid_generator,
         local_addr,
         remote_addr,
         args.shared.quic_parameters.get(alpn),

neqo-bin/src/client/http3.rs

@@ -23,7 +23,7 @@ use neqo_crypto::{AuthenticationStatus, ResumptionToken};
 use neqo_http3::{Error, Http3Client, Http3ClientEvent, Http3Parameters, Http3State, Priority};
 use neqo_transport::{
     AppError, CloseReason, Connection, EmptyConnectionIdGenerator, Error as TransportError, Output,
-    StreamId,
+    RandomConnectionIdGenerator, StreamId,
 };
 use url::Url;
 
@@ -69,10 +69,18 @@ pub fn create_client(
     hostname: &str,
     resumption_token: Option<ResumptionToken>,
 ) -> Res<Http3Client> {
+    let cid_generator: Rc<RefCell<dyn neqo_transport::ConnectionIdGenerator>> = if args.cid_len == 0
+    {
+        Rc::new(RefCell::new(EmptyConnectionIdGenerator::default()))
+    } else {
+        Rc::new(RefCell::new(RandomConnectionIdGenerator::new(
+            args.cid_len.into(),
+        )))
+    };
     let mut transport = Connection::new_client(
         hostname,
         &[&args.shared.alpn],
-        Rc::new(RefCell::new(EmptyConnectionIdGenerator::default())),
+        cid_generator,
         local_addr,
         remote_addr,
         args.shared.quic_parameters.get(args.shared.alpn.as_str()),

neqo-bin/src/client/mod.rs

@@ -169,6 +169,11 @@ pub struct Args {
     /// Print connection stats after close.
     #[arg(name = "stats", long)]
     stats: bool,
+
+    /// The length of the local connection ID.
+    #[arg(name = "cid-length", short = 'l', long, default_value = "0",
+          value_parser = clap::value_parser!(u8).range(..=20))]
+    cid_len: u8,
 }
 
 impl Args {
@@ -198,6 +203,7 @@ impl Args {
             test: None,
             upload_size: 100,
             stats: false,
+            cid_len: 0,
         }
     }
 
@@ -245,13 +251,13 @@ impl Args {
                     self.method = String::from("POST");
                 }
             }
-            "handshake"
-            | "transfer"
-            | "retry"
-            | "ecn"
-            | "rebind-port"
-            | "rebind-addr"
-            | "connectionmigration" => {}
+            "handshake" | "transfer" | "retry" | "ecn" => {}
+            "rebind-port" | "rebind-addr" | "connectionmigration" => {
+                if self.cid_len == 0 {
+                    qinfo!("Rebind/migration test won't work with len-0 CID; overwriting to 8");
+                    self.cid_len = 8;
+                }
+            }
             "resumption" => {
                 if self.urls.len() < 2 {
                     qerror!("Warning: resumption test won't work without >1 URL");