Signed-off-by: Shinpei Muraoka <[email protected]>
---
ryu/lib/packet/bgp.py | 247 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 244 insertions(+), 3 deletions(-)
diff --git a/ryu/lib/packet/bgp.py b/ryu/lib/packet/bgp.py
index cfe8cff..47feeb3 100644
--- a/ryu/lib/packet/bgp.py
+++ b/ryu/lib/packet/bgp.py
@@ -29,6 +29,7 @@ import functools
import io
import itertools
import math
+import re
import socket
import struct
@@ -2059,6 +2060,16 @@ class _FlowSpecNLRIBase(StringifyMixin, TypeDisp):
return buf + rules_bin
+ @classmethod
+ def _from_user(cls, **kwargs):
+ rules = []
+ for k, v in kwargs.items():
+ subcls = _FlowSpecComponentBase.lookup_type_name(k)
+ rule = subcls.from_str(str(v))
+ rules.extend(rule)
+ rules.sort(key=lambda x: x.type)
+ return cls(rules=rules)
+
class FlowSpecIPv4NLRI(_FlowSpecNLRIBase):
"""
@@ -2066,18 +2077,119 @@ class FlowSpecIPv4NLRI(_FlowSpecNLRIBase):
"""
ROUTE_FAMILY = RF_IPv4_FLOW_SPEC
+ @classmethod
+ def from_user(cls, **kwargs):
+ """
+ Utility method for creating a NLRI instance.
+
+ This function returns a NLRI instance from human readable format value.
+
+ :param kwargs: The following arguments are available.
+
+ =========== ============= ========= ==============================
+ Argument Value Operator Description
+ =========== ============= ========= ==============================
+ dst_prefix IPv4 Prefix Nothing Destination Prefix.
+ src_prefix IPv4 Prefix Nothing Source Prefix.
+ ip_proto Integer Numeric IP Protocol.
+ port Integer Numeric Port number.
+ dst_port Integer Numeric Destination port number.
+ src_port Integer Numeric Source port number.
+ icmp_type Integer Numeric ICMP type.
+ icmp_code Integer Numeric ICMP code.
+ tcp_flags Fixed string Bitmask TCP flags.
+ Supported values are
+ ``CWR``, ``ECN``, ``URGENT``,
+ ``ACK``, ``PUSH``, ``RST``,
+ ``SYN`` and ``FIN``.
+ packet_len Integer Numeric Packet length.
+ dscp Integer Numeric Differentiated Services
+ Code Point.
+ fragment Fixed string Bitmask Fragment.
+ Supported values are
+ ``DF`` (Don't fragment),
+ ``ISF`` (Is a fragment),
+ ``FF`` (First fragment) and
+ ``LF`` (Last fragment)
+ =========== ============= ========= ==============================
+
+ Example::
+ >>> msg = bgp.FlowSpecIPv4NLRI.from_user(
+ ... dst_prefix='10.0.0.0/24',
+ ... src_prefix='20.0.0.1/24',
+ ... ip_proto='==6',
+ ... port='==80 | ==8000',
+ ... dst_port='>9000 & <9050',
+ ... src_port='>=8500 & <=9000',
+ ... icmp_type='==0',
+ ... icmp_code='==6',
+ ... tcp_flags='SYN+ACK & !=URGENT',
+ ... packet_len='==1000',
+ ... dscp='==22 | ==24',
+ ... fragment='LF | ==FF')
+ >>>
+
+ You can specify conditions with the following keywords.
+
+ The following keywords can be used when the operator type is Numeric.
+
+ ========== ============================================================
+ Keyword Description
+ ========== ============================================================
+ < Less than comparison between data and value.
+ <= Less than or equal to comparison between data and value.
+ > Greater than comparison between data and value.
+ >= Greater than or equal to comparison between data and value.
+ == Equality between data and value.
+ This operator can be omitted.
+ ========== ============================================================
+
+ The following keywords can be used when the operator type is Bitmask.
+
+ ========== ================================================
+ Keyword Description
+ ========== ================================================
+ != Not equal operation.
+ == Exact match operation if specified.
+ Otherwise partial match operation.
+ `+` Used for the summation of bitmask values.
+ (e.g., SYN+ACK)
+ ========== ================================================
+
+ You can combine the multiple conditions with the following operators.
+
+ ========== =======================================
+ Keyword Description
+ ========== =======================================
+ `|` Logical OR operation
+ & Logical AND operation
+ ========== =======================================
+
+ :return: A instance of FlowSpecVPNv4NLRI.
+ """
+ return cls._from_user(**kwargs)
+
class FlowSpecVPNv4NLRI(_FlowSpecNLRIBase):
"""
Flow Specification NLRI class for VPNv4 [RFC 5575]
+
+ See :py:mod:`ryu.lib.packet.bgp.FlowSpecIPv4NLRI`
"""
ROUTE_FAMILY = RF_VPNv4_FLOW_SPEC
+ @classmethod
+ def from_user(cls, **kwargs):
+
+ return cls._from_user(**kwargs)
+
class _FlowSpecComponentBase(StringifyMixin, TypeDisp):
"""
Base class for Flow Specification NLRI component
"""
+ COMPONENT_NAME = None
+
_BASE_STR = '!B'
_BASE_STR_SIZE = struct.calcsize(_BASE_STR)
@@ -2094,12 +2206,34 @@ class _FlowSpecComponentBase(StringifyMixin, TypeDisp):
TYPE_DIFFSERV_CODE_POINT = 0x0b
TYPE_FRAGMENT = 0x0c
+ # Dictionary of COMPONENT_NAME to subclass.
+ # e.g.)
+ # _NAMES = {'dst_prefix': FlowSpecDestPrefix, ...}
+ _NAMES = {}
+
def __init__(self, type_=None):
if type_ is None:
type_ = self._rev_lookup_type(self.__class__)
self.type = type_
@classmethod
+ def register_type(cls, type_):
+ cls._TYPES = cls._TYPES.copy()
+ cls._NAMES = cls._NAMES.copy()
+
+ def _register_type(subcls):
+ cls._TYPES[type_] = subcls
+ cls._NAMES[subcls.COMPONENT_NAME] = subcls
+ cls._REV_TYPES = None
+ return subcls
+
+ return _register_type
+
+ @classmethod
+ def lookup_type_name(cls, type_name):
+ return cls._NAMES[type_name]
+
+ @classmethod
def parse_header(cls, rest):
(type_,) = struct.unpack_from(
cls._BASE_STR, six.binary_type(rest))
@@ -2145,6 +2279,13 @@ class _FlowSpecPrefixBase(_FlowSpecComponentBase,
IPAddrPrefix):
def serialize_body(self):
return self.serialize()
+ @classmethod
+ def from_str(cls, value):
+ rule = []
+ addr, length = value.split('/')
+ rule.append(cls(int(length), addr))
+ return rule
+
@_FlowSpecComponentBase.register_type(
_FlowSpecComponentBase.TYPE_DESTINATION_PREFIX)
@@ -2152,6 +2293,7 @@ class FlowSpecDestPrefix(_FlowSpecPrefixBase):
"""
Destination Prefix for Flow Specification NLRI component
"""
+ COMPONENT_NAME = 'dst_prefix'
@_FlowSpecComponentBase.register_type(
@@ -2160,6 +2302,7 @@ class FlowSpecSrcPrefix(_FlowSpecPrefixBase):
"""
Source Prefix for Flow Specification NLRI component
"""
+ COMPONENT_NAME = 'src_prefix'
class _FlowSpecOperatorBase(_FlowSpecComponentBase):
@@ -2172,15 +2315,21 @@ class _FlowSpecOperatorBase(_FlowSpecComponentBase):
value Value of component.
===================== ===============================================
"""
-
_OPE_PACK_STR = '!B'
_OPE_PACK_STR_SIZE = struct.calcsize(_OPE_PACK_STR)
_VAL_PACK_STR = '!%ds'
END_OF_LIST = 1 << 7 # END OF LIST bit
AND = 1 << 6 # AND bit
+ OR = 0 # OR
_LENGTH_BIT_MASK = 0x30 # The mask for length of the value
+ _logical_conditions = {
+ "|": OR,
+ "&": AND,
+ }
+ _comparison_conditions = {}
+
def __init__(self, operator, value, type_=None):
super(_FlowSpecOperatorBase, self).__init__(type_)
self.operator = operator
@@ -2208,6 +2357,52 @@ class _FlowSpecOperatorBase(_FlowSpecComponentBase):
return buf
+ @classmethod
+ def from_str(cls, val):
+ operator = 0
+ rules = []
+
+ # e.g.)
+ # value = '80 | ==90|>=8000&<=9000 | <100 & >110'
+ # elements = ['80', '|', '==', '90', '|', '>=', '8000', '&',
+ # '<=', '9000', '|', '<', '100', '&', '>', '110']
+ elements = [v.strip() for v in re.split(
+ r'([0-9]+)|([A-Z]+)|(\|&\+)|([!=<>]+)', val) if v and v.strip()]
+
+ elms_iter = iter(elements)
+
+ for elm in elms_iter:
+ if elm in cls._logical_conditions:
+ # ['&', '|']
+ operator |= cls._logical_conditions[elm]
+ continue
+ elif elm in cls._comparison_conditions:
+ # ['=', '<', '>', '<=', '>=' ] or ['=', '!=']
+ operator |= cls._comparison_conditions[elm]
+ continue
+ elif elm == '+':
+ # If keyword "+" is used, add the value to the previous rule.
+ # e.g.) 'SYN+ACK' or '!=SYN+ACK'
+ rules[-1].value |= cls._to_value(next(elms_iter))
+ continue
+
+ value = cls._to_value(elm)
+
+ operator = cls.normalize_operator(operator)
+
+ rules.append(cls(operator, value))
+ operator = 0
+
+ return rules
+
+ @classmethod
+ def _to_value(cls, value):
+ return value
+
+ @classmethod
+ def normalize_operator(cls, operator):
+ return operator
+
class _FlowSpecNumeric(_FlowSpecOperatorBase):
"""
@@ -2223,6 +2418,29 @@ class _FlowSpecNumeric(_FlowSpecOperatorBase):
GT = 1 << 1 # Greater than comparison bit
EQ = 1 << 0 # Equality bit
+ _comparison_conditions = {
+ '==': EQ,
+ '<': LT,
+ '>': GT,
+ '<=': LT | EQ,
+ '>=': GT | EQ
+ }
+
+ @classmethod
+ def _to_value(cls, value):
+ try:
+ return int(str(value), 0)
+ except ValueError:
+ raise ValueError('Invalid params: %s="%s"' % (
+ cls.COMPONENT_NAME, value))
+
+ @classmethod
+ def normalize_operator(cls, operator):
+ if operator & (cls.LT | cls.GT | cls.EQ):
+ return operator
+ else:
+ return operator | cls.EQ
+
class _FlowSpecBitmask(_FlowSpecOperatorBase):
"""
@@ -2237,6 +2455,19 @@ class _FlowSpecBitmask(_FlowSpecOperatorBase):
NOT = 1 << 1 # NOT bit
MATCH = 1 << 0 # MATCH bit
+ _comparison_conditions = {
+ '!=': NOT,
+ '==': MATCH,
+ }
+
+ @classmethod
+ def _to_value(cls, value):
+ try:
+ return cls.__dict__[value]
+ except KeyError:
+ raise ValueError('Invalid params: %s="%s"' % (
+ cls.COMPONENT_NAME, value))
+
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_PROTOCOL)
class FlowSpecIPProtocol(_FlowSpecNumeric):
@@ -2244,6 +2475,7 @@ class FlowSpecIPProtocol(_FlowSpecNumeric):
Set the IP protocol number at value.
"""
+ COMPONENT_NAME = 'ip_proto'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_PORT)
@@ -2252,6 +2484,7 @@ class FlowSpecPort(_FlowSpecNumeric):
Set the source or destination TCP/UDP ports at value.
"""
+ COMPONENT_NAME = 'port'
@_FlowSpecComponentBase.register_type(
@@ -2261,6 +2494,7 @@ class FlowSpecDestPort(_FlowSpecNumeric):
Set the destination port of a TCP or UDP packet at value.
"""
+ COMPONENT_NAME = 'dst_port'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_SOURCE_PORT)
@@ -2269,6 +2503,7 @@ class FlowSpecSrcPort(_FlowSpecNumeric):
Set the source port of a TCP or UDP packet at value.
"""
+ COMPONENT_NAME = 'src_port'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_ICMP)
@@ -2277,6 +2512,7 @@ class FlowSpecIcmpType(_FlowSpecNumeric):
Set the type field of an ICMP packet at value.
"""
+ COMPONENT_NAME = 'icmp_type'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_ICMP_CODE)
@@ -2285,6 +2521,7 @@ class FlowSpecIcmpCode(_FlowSpecNumeric):
Set the code field of an ICMP packet at value.
"""
+ COMPONENT_NAME = 'icmp_code'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_TCP_FLAGS)
@@ -2293,6 +2530,7 @@ class FlowSpecTCPFlags(_FlowSpecBitmask):
Supported TCP flags are CWR, ECN, URGENT, ACK, PUSH, RST, SYN and FIN.
"""
+ COMPONENT_NAME = 'tcp_flags'
# bitmask format
# 0 1 2 3 4 5 6 7
@@ -2300,8 +2538,8 @@ class FlowSpecTCPFlags(_FlowSpecBitmask):
# |CWR |ECN |URG |ACK |PSH |RST |SYN |FIN |
# +----+----+----+----+----+----+----+----+
- CWR = 1 << 6
- ECN = 1 << 5
+ CWR = 1 << 7
+ ECN = 1 << 6
URGENT = 1 << 5
ACK = 1 << 4
PUSH = 1 << 3
@@ -2317,6 +2555,7 @@ class FlowSpecPacketLen(_FlowSpecNumeric):
Set the total IP packet length at value.
"""
+ COMPONENT_NAME = 'packet_len'
@_FlowSpecComponentBase.register_type(
@@ -2326,6 +2565,7 @@ class FlowSpecDSCP(_FlowSpecNumeric):
Set the 6-bit DSCP field at value. [RFC2474]
"""
+ COMPONENT_NAME = 'dscp'
@_FlowSpecComponentBase.register_type(_FlowSpecComponentBase.TYPE_FRAGMENT)
@@ -2344,6 +2584,7 @@ class FlowSpecFragment(_FlowSpecBitmask):
DF Don't fragment
========== ===============================================
"""
+ COMPONENT_NAME = 'fragment'
# bitmask format
# 0 1 2 3 4 5 6 7
--
2.7.4
------------------------------------------------------------------------------
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