diff options
| -rw-r--r-- | ryu/lib/packet/ipv4.py | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/ryu/lib/packet/ipv4.py b/ryu/lib/packet/ipv4.py index e4f87782..2adf6895 100644 --- a/ryu/lib/packet/ipv4.py +++ b/ryu/lib/packet/ipv4.py @@ -14,6 +14,7 @@ # limitations under the License. import struct +import socket from . import packet_base from . import packet_utils from . import udp @@ -69,8 +70,13 @@ class ipv4(packet_base.PacketBase): struct.pack_into(ipv4._PACK_STR, hdr, 0, version, self.tos, self.total_length, self.identification, flags, self.ttl, self.proto, 0, self.src, self.dst) - self.csum = packet_utils.checksum(hdr) - struct.pack_into('H', hdr, 10, self.csum) + + if self.option: + assert struct.calcsize('I') >= len(self.option) + hdr[ipv4._MIN_LEN:ipv4._MIN_LEN + len(self.option)] = self.option + + self.csum = socket.htons(packet_utils.checksum(hdr)) + struct.pack_into('!H', hdr, 10, self.csum) return hdr ipv4.register_packet_type(tcp.tcp, inet.IPPROTO_TCP) |