openstack
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deb-ryu
Code Issues Proposed changes

packet/bgp: Properly calculate length for FlowSpec 

RFC 5575 says the 'len' field in numeric or bitmask operators
represents that the length of the value field is [1 << 'len'].
But, in serializing FlowSpec messages, the packet library uses
the `len` field as the length of the value field itself.
This patch fixes it to serialize FlowSpec messages properly.

Signed-off-by: Satoshi Fujimoto <satoshi.fujimoto7@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
This commit is contained in:
Satoshi Fujimoto 2017-05-09 16:09:53 +09:00 committed by FUJITA Tomonori
parent 9a4e8968ed
commit b327981534
1 changed files with 5 additions and 4 deletions
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9
ryu/lib/packet/bgp.py
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@ -2661,11 +2661,12 @@ class _FlowSpecOperatorBase(_FlowSpecComponentBase):
return cls(operator, value), rest
def serialize_body(self):
length = (self.value.bit_length() + 7) // 8 or 1
self.operator |= int(math.log(length, 2)) << 4
byte_length = (self.value.bit_length() + 7) // 8 or 1
length = int(math.ceil(math.log(byte_length, 2)))
self.operator |= length << 4
buf = struct.pack(self._OPE_PACK_STR, self.operator)
value_type = type_desc.IntDescr(length)
buf += struct.pack(self._VAL_PACK_STR % length,
value_type = type_desc.IntDescr(1 << length)
buf += struct.pack(self._VAL_PACK_STR % (1 << length),
value_type.from_user(self.value))
return buf