fix(proto): reject packet lengths usize cannot represent

crates/irtt-client/src/client/tests/support.rs

@@ -1,8 +1,8 @@
 use super::*;
-pub(crate) use irtt_proto::echo_packet_len;
 use irtt_proto::{
-    encode_echo_reply, encode_open_reply, flags::FLAG_OPEN, flags::FLAG_REPLY,
-    layout::PacketLayout, Clock, EchoReply, OpenReply, ReceivedStats, StampAt,
+    echo_packet_len as checked_echo_packet_len, encode_echo_reply, encode_open_reply,
+    flags::FLAG_OPEN, flags::FLAG_REPLY, layout::PacketLayout, Clock, EchoReply, OpenReply,
+    ReceivedStats, StampAt,
 };
 use std::{
     net::UdpSocket,
@@ -72,6 +72,12 @@ pub(super) fn open_reply(
     .unwrap()
 }
 
+/// Test params always name a representable length, so the platform
+/// representability check cannot fire here.
+pub(crate) fn echo_packet_len(hmac: bool, params: &Params) -> usize {
+    checked_echo_packet_len(hmac, params).expect("test params must have a representable length")
+}
+
 pub(super) fn echo_reply_packet(
     token: u64,
     seq: u32,