Initial emulator packet support

gradle.properties

@@ -1,5 +1,5 @@
 kotlin.code.style=official
 
 group=io.rebble.libpebblecommon
-version=0.0.16
+version=0.0.17
 org.gradle.jvmargs=-Xms1G

src/commonMain/kotlin/io/rebble/libpebblecommon/packets/Emulator.kt

@@ -0,0 +1,44 @@
+package io.rebble.libpebblecommon.packets
+
+import io.rebble.libpebblecommon.exceptions.PacketDecodeException
+import io.rebble.libpebblecommon.protocolhelpers.PebblePacket
+import io.rebble.libpebblecommon.structmapper.SBytes
+import io.rebble.libpebblecommon.structmapper.SUShort
+import io.rebble.libpebblecommon.structmapper.StructMapper
+import io.rebble.libpebblecommon.util.DataBuffer
+
+const val HEADER_SIGNATURE = 0xFEEDU
+const val FOOTER_SIGNATURE = 0xBEEFU
+
+open class QemuInboundPacket {
+    val m = StructMapper()
+    val signature = SUShort(m, HEADER_SIGNATURE.toUShort())
+    val protocol = SUShort(m)
+    val length = SUShort(m)
+
+    class QemuSPP: QemuInboundPacket() {
+        val payload = SBytes(m)
+        val footer = SUShort(m, FOOTER_SIGNATURE.toUShort())
+
+        init {
+            payload.linkWithSize(length)
+        }
+    }
+
+    companion object {
+        fun deserialize(packet: UByteArray): QemuInboundPacket {
+            val buf = DataBuffer(packet)
+            val meta = StructMapper()
+            val header = SUShort(meta)
+            val protocol = SUShort(meta)
+            meta.fromBytes(buf)
+            return when (protocol.get()) {
+                1u.toUShort() -> QemuSPP().also { it.m.fromBytes(buf) }
+                else -> {
+                    println("Warning: QEMU packet left generic")
+                    QemuInboundPacket().also { it.m.fromBytes(buf) }
+                }
+            }
+        }
+    }
+}

src/commonMain/kotlin/io/rebble/libpebblecommon/structmapper/types.kt

@@ -267,21 +267,21 @@ class SFixedString(mapper: StructMapper, size: Int, default: String = "") :
 
 /**
  * Represents arbitrary bytes in a struct
- * @param length the number of bytes, when serializing this is used to pad/truncate the provided value to ensure it's 'length' bytes long
+ * @param length the number of bytes, when serializing this is used to pad/truncate the provided value to ensure it's 'length' bytes long (-1 to disable this)
  */
 class SBytes(
     mapper: StructMapper,
-    length: Int,
+    length: Int = -1,
     default: UByteArray = ubyteArrayOf(),
     endianness: Char = '|'
 ) :
     StructElement<UByteArray>(
         { buf, el ->
             if (el.size != 0) {
                 var mValue = el.get()
-                if (mValue.size > el.size) {
+                if (el.size != -1 && mValue.size > el.size) {
                     mValue = el.get().sliceArray(0 until length - 1) // Truncate if too long
-                } else if (mValue.size < length) {
+                } else if (el.size != -1 && mValue.size < length) {
                     mValue += UByteArray(length - el.size)// Pad if too short
                 }
                 buf.putBytes(if (el.isLittleEndian) mValue.reversedArray() else mValue)