Add more decoders that can be used by KVParser.
For IPv4 and IPv6 addresses, create a new class that wraps
netaddr.IPAddress.
For Ethernet addresses, create a new class that wraps netaddr.EUI.
For Integers, create a new class that performs basic bitwise mask
comparisons
Acked-by: Eelco Chaudron <echau...@redhat.com>
Signed-off-by: Adrian Moreno <amore...@redhat.com>
---
python/ovs/flows/decoders.py | 398 +++++++++++++++++++++++++++++++++++
python/setup.py | 2 +-
2 files changed, 399 insertions(+), 1 deletion(-)
diff --git a/python/ovs/flows/decoders.py b/python/ovs/flows/decoders.py
index 0c2259c76..883e61acf 100644
--- a/python/ovs/flows/decoders.py
+++ b/python/ovs/flows/decoders.py
@@ -5,6 +5,15 @@ A decoder is generally a callable that accepts a string and
returns the value
object.
"""
+import netaddr
+
+
+class Decoder(object):
+ """Base class for all decoder classes."""
+
+ def to_json(self):
+ raise NotImplementedError()
+
def decode_default(value):
"""Default decoder.
@@ -16,3 +25,392 @@ def decode_default(value):
return int(value, 0)
except ValueError:
return value
+
+
+def decode_flag(value):
+ """Decode a flag. It's existence is just flagged by returning True."""
+ return True
+
+
+def decode_int(value):
+ """Integer decoder.
+
+ Both base10 and base16 integers are supported.
+
+ Used for fields such as:
+ n_bytes=34
+ metadata=0x4
+ """
+ return int(value, 0)
+
+
+def decode_time(value):
+ """Time decoder.
+
+ Used for fields such as:
+ duration=1234.123s
+ """
+ if value == "never":
+ return value
+
+ time_str = value.rstrip("s")
+ return float(time_str)
+
+
+class IntMask(Decoder):
+ """Base class for Integer Mask decoder classes.
+
+ It supports decoding a value/mask pair. The class has to be derived,
+ and the size attribute must be set.
+ """
+
+ size = None # Size in bits.
+
+ def __init__(self, string):
+ if not self.size:
+ raise NotImplementedError(
+ "IntMask should be derived and size should be fixed"
+ )
+
+ parts = string.split("/")
+ if len(parts) > 1:
+ self._value = int(parts[0], 0)
+ self._mask = int(parts[1], 0)
+ if self._mask.bit_length() > self.size:
+ raise ValueError(
+ "Integer mask {} is bigger than size {}".format(
+ self._mask, self.size
+ )
+ )
+ else:
+ self._value = int(parts[0], 0)
+ self._mask = self.max_mask()
+
+ if self._value.bit_length() > self.size:
+ raise ValueError(
+ "Integer value {} is bigger than size {}".format(
+ self._value, self.size
+ )
+ )
+
+ @property
+ def value(self):
+ return self._value
+
+ @property
+ def mask(self):
+ return self._mask
+
+ def max_mask(self):
+ return 2 ** self.size - 1
+
+ def fully(self):
+ """Returns True if it's fully masked."""
+ return self._mask == self.max_mask()
+
+ def __str__(self):
+ if self.fully():
+ return str(self._value)
+ else:
+ return "{}/{}".format(hex(self._value), hex(self._mask))
+
+ def __repr__(self):
+ return "%s('%s')" % (self.__class__.__name__, self)
+
+ def __eq__(self, other):
+ """Equality operator.
+
+ Both value and mask must be the same for the comparison to result True.
+ This can be used to implement filters that expect a specific mask,
+ e.g: ct.state = 0x1/0xff.
+
+ Args:
+ other (IntMask): Another IntMask to compare against.
+
+ Returns:
+ True if the other IntMask is the same as this one.
+ """
+ if isinstance(other, IntMask):
+ return self.value == other.value and self.mask == other.mask
+ elif isinstance(other, int):
+ return self.value == other and self.mask == self.max_mask()
+ else:
+ raise ValueError("Cannot compare against ", other)
+
+ def __contains__(self, other):
+ """Contains operator.
+
+ Args:
+ other (int or IntMask): Another integer or fully-masked IntMask
+ to compare against.
+
+ Returns:
+ True if the other integer or fully-masked IntMask is
+ contained in this IntMask.
+
+ Example:
+ 0x1 in IntMask("0xf1/0xff"): True
+ 0x1 in IntMask("0xf1/0x0f"): True
+ 0x1 in IntMask("0xf1/0xf0"): False
+ """
+ if isinstance(other, IntMask):
+ if other.fully():
+ return other.value in self
+ else:
+ raise ValueError(
+ "Comparing non fully-masked IntMasks is not supported"
+ )
+ else:
+ return other & self._mask == self._value & self._mask
+
+ def dict(self):
+ return {"value": self._value, "mask": self._mask}
+
+ def to_json(self):
+ return self.dict()
+
+
+class Mask8(IntMask):
+ size = 8
+
+
+class Mask16(IntMask):
+ size = 16
+
+
+class Mask32(IntMask):
+ size = 32
+
+
+class Mask64(IntMask):
+ size = 64
+
+
+class Mask128(IntMask):
+ size = 128
+
+
+class Mask992(IntMask):
+ size = 992
+
+
+def decode_mask(mask_size):
+ """Value/Mask decoder for values of specific size (bits).
+
+ Used for fields such as:
+ reg0=0x248/0xff
+ """
+
+ class Mask(IntMask):
+ size = mask_size
+ __name__ = "Mask{}".format(size)
+
+ return Mask
+
+
+class EthMask(Decoder):
+ """EthMask represents an Ethernet address with optional mask.
+
+ It uses netaddr.EUI.
+
+ Attributes:
+ eth (netaddr.EUI): The Ethernet address.
+ mask (netaddr.EUI): Optional, the Ethernet address mask.
+
+ Args:
+ string (str): A string representing the masked Ethernet address
+ e.g: 00.11:22:33:44:55 or 01:00:22:00:33:00/01:00:00:00:00:00
+ """
+
+ def __init__(self, string):
+ mask_parts = string.split("/")
+ self._eth = netaddr.EUI(mask_parts[0])
+ if len(mask_parts) == 2:
+ self._mask = netaddr.EUI(mask_parts[1])
+ else:
+ self._mask = None
+
+ @property
+ def eth(self):
+ """The Ethernet address."""
+ return self._eth
+
+ @property
+ def mask(self):
+ """The Ethernet address mask."""
+ return self._mask
+
+ def __eq__(self, other):
+ """Equality operator.
+
+ Both the Ethernet address and the mask are compared. This can be used
+ to implement filters where we expect a specific mask to be present,
+ e.g: dl_dst=01:00:00:00:00:00/01:00:00:00:00:00.
+
+ Args:
+ other (EthMask): Another EthMask to compare against.
+
+ Returns:
+ True if this EthMask is the same as the other.
+ """
+ return self._mask == other._mask and self._eth == other._eth
+
+ def __contains__(self, other):
+ """Contains operator.
+
+ Args:
+ other (netaddr.EUI or EthMask): An Ethernet address.
+
+ Returns:
+ True if the other netaddr.EUI or fully-masked EthMask is
+ contained in this EthMask's address range.
+ """
+ if isinstance(other, EthMask):
+ if other._mask:
+ raise ValueError(
+ "Comparing non fully-masked EthMask is not supported"
+ )
+ return other._eth in self
+
+ if self._mask:
+ return (other.value & self._mask.value) == (
+ self._eth.value & self._mask.value
+ )
+ else:
+ return other == self._eth
+
+ def __str__(self):
+ if self._mask:
+ return "/".join(
+ [
+ self._eth.format(netaddr.mac_unix),
+ self._mask.format(netaddr.mac_unix),
+ ]
+ )
+ else:
+ return self._eth.format(netaddr.mac_unix)
+
+ def __repr__(self):
+ return "%s('%s')" % (self.__class__.__name__, self)
+
+ def to_json(self):
+ return str(self)
+
+
+class IPMask(Decoder):
+ """IPMask stores an IPv6 or IPv4 and a mask.
+
+ It uses netaddr.IPAddress.
+
+ IPMasks can represent valid CIDRs or randomly masked IP Addresses.
+
+ Args:
+ string (str): A string representing the ip/mask.
+ """
+
+ def __init__(self, string):
+ self._ipnet = None
+ self._ip = None
+ self._mask = None
+ try:
+ self._ipnet = netaddr.IPNetwork(string)
+ except netaddr.AddrFormatError:
+ pass
+
+ if not self._ipnet:
+ # It's not a valid CIDR. Store ip and mask independently.
+ parts = string.split("/")
+ if len(parts) != 2:
+ raise ValueError(
+ "value {}: is not an ipv4 or ipv6 address".format(string)
+ )
+ try:
+ self._ip = netaddr.IPAddress(parts[0])
+ self._mask = netaddr.IPAddress(parts[1])
+ except netaddr.AddrFormatError as exc:
+ raise ValueError(
+ "value {}: is not an ipv4 or ipv6 address".format(string)
+ ) from exc
+
+ def __eq__(self, other):
+ """Equality operator.
+
+ Both the IPAddress and the mask are compared. This can be used
+ to implement filters where a specific mask is expected, e.g:
+ nw_src=192.168.1.0/24.
+
+ Args:
+ other (IPMask or netaddr.IPNetwork or netaddr.IPAddress):
+ Another IPAddress or IPNetwork to compare against.
+
+ Returns:
+ True if this IPMask is the same as the other.
+ """
+ if isinstance(other, netaddr.IPNetwork):
+ return self._ipnet and self._ipnet == other
+ if isinstance(other, netaddr.IPAddress):
+ return self._ipnet and self._ipnet.ip == other
+ elif isinstance(other, IPMask):
+ if self._ipnet:
+ return self._ipnet == other._ipnet
+
+ return self._ip == other._ip and self._mask == other._mask
+ else:
+ return False
+
+ def __contains__(self, other):
+ """Contains operator.
+
+ Only comparing valid CIDRs is supported.
+
+ Args:
+ other (netaddr.IPAddress or IPMask): An IP address.
+
+ Returns:
+ True if the other IPAddress is contained in this IPMask's address
+ range.
+ """
+ if isinstance(other, IPMask):
+ if not other._ipnet:
+ raise ValueError("Only comparing valid CIDRs is supported")
+
+ return (
+ netaddr.IPAddress(other._ipnet.first) in self
+ and netaddr.IPAddress(other._ipnet.last) in self
+ )
+
+ elif isinstance(other, netaddr.IPAddress):
+ if self._ipnet:
+ return other in self._ipnet
+ return (other & self._mask) == (self._ip & self._mask)
+
+ def cidr(self):
+ """
+ Returns True if the IPMask is a valid CIDR.
+ """
+ return self._ipnet is not None
+
+ @property
+ def ip(self):
+ """The IP address."""
+ if self._ipnet:
+ return self._ipnet.ip
+ return self._ip
+
+ @property
+ def mask(self):
+ """The IP mask."""
+ if self._ipnet:
+ return self._ipnet.netmask
+ return self._mask
+
+ def __str__(self):
+ if self._ipnet:
+ return str(self._ipnet)
+ return "/".join([str(self._ip), str(self._mask)])
+
+ def __repr__(self):
+ return "%s('%s')" % (self.__class__.__name__, self)
+
+ def to_json(self):
+ return str(self)
diff --git a/python/setup.py b/python/setup.py
index 0e6b0ea39..b06370bd9 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -87,7 +87,7 @@ setup_args = dict(
ext_modules=[setuptools.Extension("ovs._json", sources=["ovs/_json.c"],
libraries=['openvswitch'])],
cmdclass={'build_ext': try_build_ext},
- install_requires=['sortedcontainers'],
+ install_requires=['sortedcontainers', 'netaddr'],
extras_require={':sys_platform == "win32"': ['pywin32 >= 1.0']},
)
--
2.34.1
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