From 803de68fdcfe4097e78920e8545b2947d04dd6a7 Mon Sep 17 00:00:00 2001
From: Momics <momics.eu@gmail.com>
Date: Mon, 20 Jul 2026 14:42:21 +0200
Subject: [PATCH 1/2] fix(core): disable QUIC GSO on Android

---
 crates/iroh-http-core/src/endpoint/bind.rs | 45 +++++++++++++++++-----
 1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/crates/iroh-http-core/src/endpoint/bind.rs b/crates/iroh-http-core/src/endpoint/bind.rs
index 41461d45..f025637f 100644
--- a/crates/iroh-http-core/src/endpoint/bind.rs
+++ b/crates/iroh-http-core/src/endpoint/bind.rs
@@ -25,6 +25,16 @@ use super::{
     EndpointInner, IrohEndpoint,
 };
 
+/// Whether QUIC may batch UDP datagrams using segmentation offload.
+///
+/// Android kernels can advertise this capability and then reject batched sends.
+/// Until noq retries rejected batches as individual datagrams, disabling the
+/// optimization avoids losing the affected packets on Android. Remove this
+/// policy after <https://github.com/n0-computer/noq/pull/746> is released.
+fn segmentation_offload_enabled(target_os: &str) -> bool {
+    target_os != "android"
+}
+
 impl IrohEndpoint {
     /// Bind an Iroh endpoint with the supplied options.
     pub async fn bind(opts: NodeOptions) -> Result<Self, crate::CoreError> {
@@ -142,21 +152,16 @@ impl IrohEndpoint {
             builder = builder.secret_key(SecretKey::from_bytes(&key_bytes));
         }
 
+        let mut transport = QuicTransportConfig::builder()
+            .max_concurrent_bidi_streams(128u32.into())
+            .enable_segmentation_offload(segmentation_offload_enabled(std::env::consts::OS));
         if let Some(ms) = opts.networking.idle_timeout_ms {
             let timeout = IdleTimeout::try_from(Duration::from_millis(ms)).map_err(|e| {
                 crate::CoreError::invalid_input(format!("idle_timeout_ms out of range: {e}"))
             })?;
-            let transport = QuicTransportConfig::builder()
-                .max_idle_timeout(Some(timeout))
-                .max_concurrent_bidi_streams(128u32.into())
-                .build();
-            builder = builder.transport_config(transport);
-        } else {
-            let transport = QuicTransportConfig::builder()
-                .max_concurrent_bidi_streams(128u32.into())
-                .build();
-            builder = builder.transport_config(transport);
+            transport = transport.max_idle_timeout(Some(timeout));
         }
+        builder = builder.transport_config(transport.build());
 
         // Bind address(es).
         for addr_str in &opts.networking.bind_addrs {
@@ -567,3 +572,23 @@ mod direct_addr_tests {
         }
     }
 }
+
+#[cfg(test)]
+mod transport_policy_tests {
+    use super::segmentation_offload_enabled;
+
+    #[test]
+    fn android_disables_udp_segmentation_offload() {
+        assert!(!segmentation_offload_enabled("android"));
+    }
+
+    #[test]
+    fn non_android_platforms_keep_udp_segmentation_offload() {
+        for target in ["ios", "macos", "linux", "windows"] {
+            assert!(
+                segmentation_offload_enabled(target),
+                "{target} should retain the upstream default"
+            );
+        }
+    }
+}

From b9e7a507805d28e8f067e58952e01e045f79fc2d Mon Sep 17 00:00:00 2001
From: Momics <momics.eu@gmail.com>
Date: Mon, 20 Jul 2026 15:39:50 +0200
Subject: [PATCH 2/2] docs(core): link Android GSO removal tracker

---
 crates/iroh-http-core/src/endpoint/bind.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crates/iroh-http-core/src/endpoint/bind.rs b/crates/iroh-http-core/src/endpoint/bind.rs
index f025637f..e04a40d7 100644
--- a/crates/iroh-http-core/src/endpoint/bind.rs
+++ b/crates/iroh-http-core/src/endpoint/bind.rs
@@ -29,8 +29,10 @@ use super::{
 ///
 /// Android kernels can advertise this capability and then reject batched sends.
 /// Until noq retries rejected batches as individual datagrams, disabling the
-/// optimization avoids losing the affected packets on Android. Remove this
-/// policy after <https://github.com/n0-computer/noq/pull/746> is released.
+/// optimization avoids losing the affected packets on Android. Removal is
+/// tracked in <https://github.com/momics/iroh-http/issues/388>; wait until
+/// <https://github.com/n0-computer/noq/pull/746> ships through a released iroh
+/// version and the physical-device matrix passes.
 fn segmentation_offload_enabled(target_os: &str) -> bool {
     target_os != "android"
 }