ci: run on Android API Level 25

.github/workflows/rust-android-run-tests-on-emulator.sh

@@ -8,7 +8,7 @@ any_failures=0
 for test in $(find target/$TARGET/debug/deps/ -type f -executable ! -name "*.so" -name "*-*"); do
     adb push "$test" /data/local/tmp/
     adb shell chmod +x /data/local/tmp/$(basename "$test")
-    adb shell /data/local/tmp/$(basename "$test") || any_failures=1
+    adb shell API_LEVEL=$API_LEVEL /data/local/tmp/$(basename "$test") || any_failures=1
 done
 
 exit $any_failures

.github/workflows/rust.yml

@@ -222,17 +222,19 @@ jobs:
 
     strategy:
       matrix:
-        include:
+        target: [x86_64-linux-android, i686-linux-android]
+        emulator-arch: [x86_64, x86]
+        api-level: [26, 25]
+        exclude:
           - target: x86_64-linux-android
-            emulator-arch: x86_64
-            # Note that x86_64 image is only available for API 21+. See
-            # https://github.com/ReactiveCircus/android-emulator-runner?tab=readme-ov-file#configurations.
-            api-level: 26
-          - target: i686-linux-android
             emulator-arch: x86
-            api-level: 26
+          - target: i686-linux-android
+            emulator-arch: x86_64
 
     steps:
+    - name: Set API level environment variable
+      run: echo "API_LEVEL=${{ matrix.api-level }}" >> $GITHUB_ENV
+
     - name: Checkout code
       uses: actions/checkout@v4
 

quinn-udp/src/lib.rs

@@ -106,8 +106,8 @@ pub struct RecvMeta {
     pub ecn: Option<EcnCodepoint>,
     /// The destination IP address which was encoded in this datagram
     ///
-    /// Populated on platforms: Windows, Linux, Android, FreeBSD, OpenBSD, NetBSD, macOS,
-    /// and iOS.
+    /// Populated on platforms: Windows, Linux, Android (API level > 25),
+    /// FreeBSD, OpenBSD, NetBSD, macOS, and iOS.
     pub dst_ip: Option<IpAddr>,
 }
 

quinn-udp/tests/tests.rs

@@ -225,9 +225,12 @@ fn test_send_recv(send: &Socket, recv: &Socket, transmit: Transmit) {
         );
         let send_v6 = send.local_addr().unwrap().as_socket().unwrap().is_ipv6();
         let recv_v6 = recv.local_addr().unwrap().as_socket().unwrap().is_ipv6();
-        let src = meta.addr.ip();
-        let dst = meta.dst_ip.unwrap();
-        for addr in [src, dst] {
+        let mut addresses = vec![meta.addr.ip()];
+        // Not populated on every OS. See `RecvMeta::dst_ip` for details.
+        if let Some(addr) = meta.dst_ip {
+            addresses.push(addr);
+        }
+        for addr in addresses {
             match (send_v6, recv_v6) {
                 (_, false) => assert_eq!(addr, Ipv4Addr::LOCALHOST),
                 // Windows gives us real IPv4 addrs, whereas *nix use IPv6-mapped IPv4
@@ -240,7 +243,23 @@ fn test_send_recv(send: &Socket, recv: &Socket, transmit: Transmit) {
                 ),
             }
         }
-        assert_eq!(meta.ecn, transmit.ecn);
+
+        if match transmit.destination.ip() {
+            IpAddr::V4(_) => true,
+            IpAddr::V6(a) => a.to_ipv4_mapped().is_some(),
+        } && cfg!(target_os = "android")
+            && std::env::var("API_LEVEL")
+                .ok()
+                .and_then(|v| v.parse::<u32>().ok())
+                .expect("API_LEVEL environment variable to be set on Android")
+                <= 25
+        {
+            // On Android API level <= 25 the IPv4 `IP_TOS` control message is
+            // not supported and thus ECN bits can not be received.
+            assert_eq!(meta.ecn, None);
+        } else {
+            assert_eq!(meta.ecn, transmit.ecn);
+        }
     }
     assert_eq!(datagrams, expected_datagrams);
 }