Signed-off-by: Yuichi Ito <[email protected]>
---
ryu/lib/packet/tcp.py | 35 +++++++++++++++++++----------
ryu/tests/unit/packet/test_tcp.py | 45 +++++++++++++++++++++++++++++++++++++
2 files changed, 68 insertions(+), 12 deletions(-)
diff --git a/ryu/lib/packet/tcp.py b/ryu/lib/packet/tcp.py
index e6932ae..a6f0167 100644
--- a/ryu/lib/packet/tcp.py
+++ b/ryu/lib/packet/tcp.py
@@ -33,7 +33,8 @@ class tcp(packet_base.PacketBase):
dst_port Destination Port
seq Sequence Number
ack Acknowledgement Number
- offset Data Offset
+ offset Data Offset \
+ (0 means automatically-calculate when encoding)
bits Control Bits
window_size Window
csum Checksum \
@@ -47,8 +48,8 @@ class tcp(packet_base.PacketBase):
_PACK_STR = '!HHIIBBHHH'
_MIN_LEN = struct.calcsize(_PACK_STR)
- def __init__(self, src_port, dst_port, seq, ack, offset,
- bits, window_size, csum, urgent, option=None):
+ def __init__(self, src_port=0, dst_port=0, seq=0, ack=0, offset=0,
+ bits=0, window_size=0, csum=0, urgent=0, option=None):
super(tcp, self).__init__()
self.src_port = src_port
self.dst_port = dst_port
@@ -81,20 +82,30 @@ class tcp(packet_base.PacketBase):
return msg, None, buf[length:]
def serialize(self, payload, prev):
- length = len(self)
- h = bytearray(length)
offset = self.offset << 4
- 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)
+ h = bytearray(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))
if self.option:
- assert (length - tcp._MIN_LEN) >= len(self.option)
- h[tcp._MIN_LEN:tcp._MIN_LEN + len(self.option)] = self.option
+ h.extend(self.option)
+ mod = len(self.option) % 4
+ if mod:
+ h.extend(bytearray(4 - mod))
+ if self.offset:
+ offset = self.offset << 2
+ if len(h) < offset:
+ h.extend(bytearray(offset - len(h)))
+
+ if 0 == self.offset:
+ self.offset = len(h) >> 2
+ offset = self.offset << 4
+ struct.pack_into('!B', h, 12, offset)
if self.csum == 0:
- total_length = length + len(payload)
+ total_length = len(h) + len(payload)
self.csum = packet_utils.checksum_ip(prev, total_length,
h + payload)
struct.pack_into('!H', h, 16, self.csum)
- return h
+ return str(h)
diff --git a/ryu/tests/unit/packet/test_tcp.py
b/ryu/tests/unit/packet/test_tcp.py
index 5618652..4168902 100644
--- a/ryu/tests/unit/packet/test_tcp.py
+++ b/ryu/tests/unit/packet/test_tcp.py
@@ -138,3 +138,48 @@ class Test_tcp(unittest.TestCase):
def test_malformed_tcp(self):
m_short_buf = self.buf[1:tcp._MIN_LEN]
tcp.parser(m_short_buf)
+
+ def test_default_args(self):
+ prev = ipv4(proto=inet.IPPROTO_TCP)
+ t = tcp()
+ buf = t.serialize(bytearray(), prev)
+ res = struct.unpack(tcp._PACK_STR, buf)
+
+ eq_(res[0], 0)
+ eq_(res[1], 0)
+ eq_(res[2], 0)
+ eq_(res[3], 0)
+ eq_(res[4], 5 << 4)
+ eq_(res[5], 0)
+ eq_(res[6], 0)
+ eq_(res[8], 0)
+
+ # with option, without offset
+ t = tcp(option='\x01\x02\x03')
+ buf = t.serialize(bytearray(), prev)
+ res = struct.unpack(tcp._PACK_STR + '4s', buf)
+
+ eq_(res[0], 0)
+ eq_(res[1], 0)
+ eq_(res[2], 0)
+ eq_(res[3], 0)
+ eq_(res[4], 6 << 4)
+ eq_(res[5], 0)
+ eq_(res[6], 0)
+ eq_(res[8], 0)
+ eq_(res[9], '\x01\x02\x03\x00')
+
+ # with option, with long offset
+ t = tcp(offset=7, option='\x01\x02\x03')
+ buf = t.serialize(bytearray(), prev)
+ res = struct.unpack(tcp._PACK_STR + '8s', buf)
+
+ eq_(res[0], 0)
+ eq_(res[1], 0)
+ eq_(res[2], 0)
+ eq_(res[3], 0)
+ eq_(res[4], 7 << 4)
+ eq_(res[5], 0)
+ eq_(res[6], 0)
+ eq_(res[8], 0)
+ eq_(res[9], '\x01\x02\x03\x00\x00\x00\x00\x00')
--
1.7.10.4
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