prevent padding end with zero's if the limit more than actually remai…

…ning in the transport header / payload
compscidr · Oct 31, 2024 · f08897d · f08897d
1 parent bb122fe
commit f08897d
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/main/kotlin/com/jasonernst/kanonproxy/icmp/IcmpFactory.kt b/src/main/kotlin/com/jasonernst/kanonproxy/icmp/IcmpFactory.kt
@@ -19,6 +19,7 @@ import com.jasonernst.knet.transport.TransportHeader
 import java.net.Inet6Address
 import java.net.InetAddress
 import java.nio.ByteBuffer
+import kotlin.math.min
 
 object IcmpFactory {
     /**
@@ -71,8 +72,9 @@ object IcmpFactory {
                 // IPv6 header length, ICMPv6 destination unreachable min header length, IPv6 header length (the one that generated this to happen)
                 (mtu.toUInt() - IP6_HEADER_SIZE - DESTINATION_UNREACHABLE_HEADER_MIN_LENGTH - IP6_HEADER_SIZE).toInt()
             }
-        val reducedTransportBuffer = ByteArray(limit)
-        System.arraycopy(originalTransportBufferAndPayloadBuffer.array(), 0, reducedTransportBuffer, 0, limit)
+        val actualLimit = min(limit, originalTransportBufferAndPayloadBuffer.limit())
+        val reducedTransportBuffer = ByteArray(actualLimit)
+        System.arraycopy(originalTransportBufferAndPayloadBuffer.array(), 0, reducedTransportBuffer, 0, actualLimit)
         originalRequestBuffer.put(reducedTransportBuffer)
         originalRequestBuffer.rewind()