diff options
| -rw-r--r-- | ryu/lib/packet/tcp.py | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/ryu/lib/packet/tcp.py b/ryu/lib/packet/tcp.py index 73e700db..ec177f03 100644 --- a/ryu/lib/packet/tcp.py +++ b/ryu/lib/packet/tcp.py @@ -25,7 +25,7 @@ class tcp(packet_base.PacketBase): _MIN_LEN = struct.calcsize(_PACK_STR) def __init__(self, src_port, dst_port, seq, ack, offset, - bits, window_size, csum, urgent): + bits, window_size, csum, urgent, option=None): super(tcp, self).__init__() self.src_port = src_port self.dst_port = dst_port @@ -37,6 +37,7 @@ class tcp(packet_base.PacketBase): self.csum = csum self.urgent = urgent self.length = self.offset * 4 + self.option = option @classmethod def parser(cls, buf): @@ -46,13 +47,23 @@ class tcp(packet_base.PacketBase): bits = bits & 0x3f msg = cls(src_port, dst_port, seq, ack, offset, bits, window_size, csum, urgent) + + if msg.length > tcp._MIN_LEN: + msg.option = buf[tcp._MIN_LEN:msg.length] + return msg, None def serialize(self, payload, prev): + h = bytearray().zfill(self.length) offset = self.offset << 4 - h = struct.pack(tcp._PACK_STR, self.src_port, self.dst_port, - self.seq, self.ack, offset, self.bits, - self.window_size, self.csum, self.urgent) + struct.pack_into(tcp._PACK_STR, h, 0, self.src_port, self.dst_port, + self.seq, self.ack, offset, self.bits, + self.window_size, self.csum, self.urgent) + + if self.option: + assert (self.length - tcp._MIN_LEN) >= len(self.option) + h[tcp._MIN_LEN:tcp._MIN_LEN + len(self.option)] = self.option + if self.csum == 0: length = self.length + len(payload) ph = struct.pack('!IIBBH', prev.src, prev.dst, 0, 6, length) @@ -60,7 +71,5 @@ class tcp(packet_base.PacketBase): if len(f) % 2: f += '\0' self.csum = socket.htons(packet_utils.checksum(f)) - h = struct.pack(tcp._PACK_STR, self.src_port, self.dst_port, - self.seq, self.ack, offset, self.bits, - self.window_size, self.csum, self.urgent) + struct.pack_into('!H', h, 16, self.csum) return h |