Mdns issue

Author: ismartcoding

app/build.gradle.kts

@@ -81,9 +81,9 @@ android {
                 else -> 0
             }
 
-        val vCode = 538
+        val vCode = 541
         versionCode = vCode - singleAbiNum
-        versionName = "3.0.13"
+        versionName = "3.0.14"
 
         ndk {
             //noinspection ChromeOsAbiSupport

app/src/main/java/com/ismartcoding/plain/mdns/MdnsHostResponder.kt

@@ -6,6 +6,7 @@ import com.ismartcoding.lib.logcat.LogCat
 import java.net.DatagramPacket
 import java.net.DatagramSocket
 import java.net.Inet4Address
+import java.net.Inet6Address
 import java.net.InetAddress
 import java.net.InetSocketAddress
 import java.net.MulticastSocket
@@ -62,12 +63,21 @@ object MdnsHostResponder {
                 MulticastSocket(null).apply {
                     reuseAddress = true
                     soTimeout = 1000
-                    bind(InetSocketAddress(MDNS_PORT))
+                    // Explicitly bind to the IPv4 wildcard.
+                    // InetSocketAddress(port) resolves to the system-preferred wildcard, which on
+                    // Samsung Android 13+ (preferIPv6Addresses=true) becomes [::]:5353 — an IPv6
+                    // socket. Joining an IPv4 multicast group on an IPv6 socket silently fails,
+                    // leaving this socket unable to receive any mDNS queries.
+                    bind(InetSocketAddress(InetAddress.getByName("0.0.0.0"), MDNS_PORT))
+                    var joinCount = 0
                     for ((iface, ip) in candidates) {
                         runCatching { joinGroup(groupSockAddr, iface) }
-                            .onSuccess { LogCat.d("mDNS joined ${iface.name} (${ip.hostAddress})") }
+                            .onSuccess { joinCount++; LogCat.d("mDNS joined ${iface.name} (${ip.hostAddress})") }
                             .onFailure { LogCat.e("mDNS joinGroup ${iface.name}: ${it.message}") }
                     }
+                    if (joinCount == 0) {
+                        LogCat.e("mDNS: no interface joined multicast group — responder will not receive queries")
+                    }
                 }
             }.getOrElse {
                 lock?.let { l -> runCatching { l.release() } }
@@ -103,7 +113,9 @@ object MdnsHostResponder {
             val packet = DatagramPacket(buf, buf.size)
             try {
                 s.receive(packet)
-                val senderIp = packet.address as? Inet4Address ?: continue
+                // extractInet4Address handles both plain Inet4Address and IPv4-mapped IPv6
+                // addresses (::ffff:x.x.x.x) that a dual-stack socket may report.
+                val senderIp = extractInet4Address(packet.address) ?: continue
                 val fresh = candidateInterfaces()
                 if (fresh.isEmpty()) continue
                 val (_, localIp) = findResponseIface(senderIp, fresh)
@@ -129,6 +141,24 @@ object MdnsHostResponder {
         }.onFailure { LogCat.e("mDNS send to ${dest.hostAddress}: ${it.message}") }
     }
 
+    /**
+     * Returns the IPv4 address from [addr], unwrapping IPv4-mapped IPv6 addresses
+     * (::ffff:x.x.x.x) that a dual-stack socket reports for IPv4 senders.
+     */
+    internal fun extractInet4Address(addr: InetAddress): Inet4Address? {
+        if (addr is Inet4Address) return addr
+        if (addr is Inet6Address) {
+            val b = addr.address
+            // IPv4-mapped format: 10 zero bytes + 0xFF 0xFF + 4 IPv4 bytes
+            if (b.size == 16 && b[0] == 0.toByte() && b[10] == 0xFF.toByte() && b[11] == 0xFF.toByte() &&
+                b.take(10).all { it == 0.toByte() }
+            ) {
+                return runCatching { InetAddress.getByAddress(b.copyOfRange(12, 16)) as? Inet4Address }.getOrNull()
+            }
+        }
+        return null
+    }
+
     internal fun normalizeHostname(value: String): String {
         val trimmed = value.trim().trim('.').lowercase()
         if (trimmed.isEmpty()) return ""

app/src/main/java/com/ismartcoding/plain/mdns/MdnsIfaceSelector.kt

@@ -20,9 +20,17 @@ internal fun candidateInterfaces(): List<Pair<NetworkInterface, Inet4Address>> {
     runCatching {
         val ifaces = NetworkInterface.getNetworkInterfaces() ?: return result
         for (iface in ifaces.asSequence()) {
-            if (!iface.isUp || iface.isLoopback || !iface.supportsMulticast()) continue
+            if (!iface.isUp || iface.isLoopback) continue
             if (NetworkHelper.isVpnInterface(iface.name)) continue
             if (isMobileDataInterface(iface.name)) continue
+            // Samsung's Wi-Fi driver sometimes omits IFF_MULTICAST on wlan0/ap0, causing
+            // supportsMulticast() to return false even though the interface is perfectly
+            // capable of multicast. Accept any interface with a Wi-Fi/Ethernet-like name
+            // regardless of the flag, since those are always LAN interfaces.
+            val isLanLike = iface.name.startsWith("wlan") || iface.name.startsWith("ap") ||
+                iface.name.startsWith("eth") || iface.name.startsWith("swlan") ||
+                iface.name.startsWith("wl") || iface.name.startsWith("p2p")
+            if (!iface.supportsMulticast() && !isLanLike) continue
             val ip = iface.inetAddresses.asSequence()
                 .filterIsInstance<Inet4Address>()
                 .firstOrNull { !it.isLoopbackAddress } ?: continue

app/src/main/java/com/ismartcoding/plain/mdns/MdnsPacketCodec.kt

@@ -18,6 +18,10 @@ internal object MdnsPacketCodec {
     ): ByteArray? {
         if (query.size < 12 || ips.isEmpty()) return null
 
+        val flags = readU16(query, 2)
+        // Bit 15 (QR) = 1 means this is a response, not a query. Ignore it.
+        if (flags and 0x8000 != 0) return null
+
         val qdCount = readU16(query, 4)
         if (qdCount <= 0) return null
 

app/src/main/java/com/ismartcoding/plain/ui/page/audio/components/AudioActionButtons.kt

@@ -7,7 +7,6 @@ import com.ismartcoding.plain.enums.AppFeatureType
 import com.ismartcoding.plain.features.media.AudioMediaStoreHelper
 import com.ismartcoding.plain.helpers.ShareHelper
 import com.ismartcoding.plain.ui.base.ActionButtons
-import com.ismartcoding.plain.ui.base.IconTextCastButton
 import com.ismartcoding.plain.ui.base.IconTextDeleteButton
 import com.ismartcoding.plain.ui.base.IconTextOpenWithButton
 import com.ismartcoding.plain.ui.base.IconTextRenameButton
@@ -29,7 +28,6 @@ internal fun AudioActionButtons(
     dragSelectState: DragSelectState,
     context: android.content.Context,
     onDismiss: () -> Unit,
-    castVM: CastViewModel? = null,
 ) {
     ActionButtons {
         if (!audioVM.showSearchBar.value) {
@@ -43,12 +41,6 @@ internal fun AudioActionButtons(
             ShareHelper.shareUris(context, listOf(AudioMediaStoreHelper.getItemUri(m.id)))
             onDismiss()
         }
-        if (castVM != null && !m.path.isUrl()) {
-            IconTextCastButton {
-                castVM.showCastDialog.value = true
-                onDismiss()
-            }
-        }
         if (!m.path.isUrl()) {
             IconTextOpenWithButton {
                 ShareHelper.openPathWith(context, m.path)

app/src/main/java/com/ismartcoding/plain/ui/page/audio/components/ViewAudioBottomSheet.kt

@@ -74,7 +74,6 @@ fun ViewAudioBottomSheet(
                     dragSelectState = dragSelectState,
                     context = context,
                     onDismiss = onDismiss,
-                    castVM = castVM,
                 )
             }
             if (!audioVM.trash.value) {