[CONTROLLER-806] ICMP.computeChecksum() may cause ArrayIndexOutOfBoundsException.

Thu, 19 Oct 2017 22:13:14 +0000

ICMP.computeChecksum() causes ArrayIndexOutOfBoundsException if the size of
payload is odd.

java.lang.ArrayIndexOutOfBoundsException: 49
at org.opendaylight.controller.sal.packet.ICMP.computeChecksum(ICMP.java:199)
at org.opendaylight.controller.sal.packet.ICMP.postSerializeCustomOperation(ICMP.java:210)
at org.opendaylight.controller.sal.packet.Packet.serialize(Packet.java:194)

In this case the payload needs to be padded with a zero octet for computing
the checksum.

In addition, ICMP.computeChecksum() clears carry bits of the 16-bit checksum
incorrectly.

carry = (sum >> 16) & 0xFF; <===
finalSum = (sum & 0xFFFF) + carry;
return (short) ~((short) finalSum & 0xFFFF);

So it generates incorrect checksum if the 16-bit checksum overflows
more than 255 times.

OpenDaylight JIRA

[CONTROLLER-806] ICMP.computeChecksum() may cause ArrayIndexOutOfBoundsException.