From fc6a4caaf1f7da48cb63e3906d5a07de6d49c977 Mon Sep 17 00:00:00 2001
From: Pierre LALET <pierre.lalet@cea.fr>
Date: Tue, 17 Jan 2017 02:04:07 +0100
Subject: [PATCH] Introduce FlagValue(int) objects to represent FlagsField()
values
This makes it possible to write `if pkt[TCP].flags.S: [...]`.
---
scapy/base_classes.py | 4 +--
scapy/fields.py | 82 ++++++++++++++++++++++++++++---------------
test/regression.uts | 40 +++++++++++++++++----
3 files changed, 90 insertions(+), 36 deletions(-)
diff --git a/scapy/base_classes.py b/scapy/base_classes.py
index 636f28d1..9e4ee778 100644
--- a/scapy/base_classes.py
+++ b/scapy/base_classes.py
@@ -24,8 +24,8 @@ class SetGen(Gen):
self._iterpacket=_iterpacket
if isinstance(values, (list, BasePacketList)):
self.values = list(values)
- elif (type(values) is tuple) and (2 <= len(values) <= 3) and \
- all(type(i) is int for i in values):
+ elif (isinstance(values, tuple) and (2 <= len(values) <= 3) and \
+ all(isinstance(i, int) for i in values)):
# We use values[1] + 1 as stop value for xrange to maintain
# the behavior of using tuples as field `values`
self.values = [xrange(*((values[0], values[1] + 1) + values[2:]))]
diff --git a/scapy/fields.py b/scapy/fields.py
index cbe15534..ca0ebb59 100644
--- a/scapy/fields.py
+++ b/scapy/fields.py
@@ -934,6 +934,49 @@ class LEFieldLenField(FieldLenField):
FieldLenField.__init__(self, name, default, length_of=length_of, fmt=fmt, count_of=count_of, fld=fld, adjust=adjust)
+class FlagValue(int):
+ __slots__ = ["names", "multi"]
+ @staticmethod
+ def __fixvalue(value, names):
+ if isinstance(value, basestring):
+ if isinstance(names, list):
+ value = value.split('+')
+ else:
+ value = list(value)
+ if isinstance(value, list):
+ y = 0
+ for i in value:
+ y |= 1 << names.index(i)
+ value = y
+ return value
+ def __new__(cls, value, names):
+ return super(FlagValue, cls).__new__(cls, cls.__fixvalue(value, names))
+ def __init__(self, value, names):
+ super(FlagValue, self).__init__(value)
+ self.multi = isinstance(names, list)
+ self.names = names
+ def flagrepr(self):
+ i = 0
+ r = []
+ x = int(self)
+ while x:
+ if x & 1:
+ r.append(self.names[i])
+ i += 1
+ x >>= 1
+ return ("+" if self.multi else "").join(r)
+ def __repr__(self):
+ return "<Flag %r (%s)>" % (int(self),
+ self.flagrepr())
+ def __deepcopy__(self, memo):
+ return self.__class__(int(self), self.names)
+ def __getattr__(self, attr):
+ try:
+ return bool((2 ** self.names.index(attr)) & int(self))
+ except ValueError:
+ return super(FlagValue, self).__getattr__(attr)
+
+
class FlagsField(BitField):
""" Handle Flag type field
@@ -957,37 +1000,20 @@ class FlagsField(BitField):
"""
__slots__ = ["multi", "names"]
def __init__(self, name, default, size, names):
- self.multi = type(names) is list
- if self.multi:
- self.names = map(lambda x:[x], names)
- else:
- self.names = names
+ self.multi = isinstance(names, list)
+ self.names = names
BitField.__init__(self, name, default, size)
def any2i(self, pkt, x):
- if type(x) is str:
- if self.multi:
- x = map(lambda y:[y], x.split("+"))
- y = 0
- for i in x:
- y |= 1 << self.names.index(i)
- x = y
- return x
+ if isinstance(x, (list, tuple)):
+ return type(x)(None if v is None else FlagValue(v, self.names)
+ for v in x)
+ return None if x is None else FlagValue(x, self.names)
def i2repr(self, pkt, x):
- if type(x) is list or type(x) is tuple:
- return repr(x)
- if self.multi:
- r = []
- else:
- r = ""
- i=0
- while x:
- if x & 1:
- r += self.names[i]
- i += 1
- x >>= 1
- if self.multi:
- r = "+".join(r)
- return r
+ if isinstance(x, (list, tuple)):
+ return repr(type(x)(
+ None if v is None else FlagValue(v, self.names).flagrepr()
+ for v in x))
+ return None if x is None else FlagValue(x, self.names).flagrepr()
MultiFlagsEntry = collections.namedtuple('MultiFlagEntry', ['short', 'long'])
diff --git a/test/regression.uts b/test/regression.uts
index 11052b84..e08eabc3 100644
--- a/test/regression.uts
+++ b/test/regression.uts
@@ -7143,7 +7143,9 @@ assert(re.match(r'^.*Star \(\*\).*$', x) is not None)
assert(re.match(r'^.*Plus \(\+\).*$', x) is not None)
assert(re.match(r'^.*bit 2.*$', x) is not None)
-###########################################################################################################
+
+############
+############
+ Test correct conversion from binary to string of IPv6 addresses
= IPv6 bin to string conversion - all zero bytes
@@ -7222,7 +7224,6 @@ assert(compressed1 == compressed2 == '1000:200:30:4:5:60:700:8000')
############
############
-
+ VRRP tests
= VRRP - build
@@ -7236,7 +7237,6 @@ VRRP in p and p[VRRP].chksum == 0x7afd
############
############
-
+ L2TP tests
= L2TP - build
@@ -7250,7 +7250,6 @@ L2TP in p and p[L2TP].len == 14 and p.tunnel_id == 0 and p[UDP].chksum == 0xf465
############
############
-
+ HSRP tests
= HSRP - build & dissection
@@ -7263,7 +7262,6 @@ assert pkt[HSRPmd5].type == 4 and pkt[HSRPmd5].sourceip == defaddr
############
############
-
+ RIP tests
= RIP - build
@@ -7277,7 +7275,6 @@ RIPEntry in p and RIPAuth in p and p[RIPAuth].password.startswith("scapy")
############
############
-
+ Radius tests
= Radius - build
@@ -7487,3 +7484,34 @@ rek == 'b'
random.seed(0x2807)
rts = RandTermString(4, "scapy")
sane(str(rts)) == "...[scapy"
+
+
+############
+############
++ Flags
+
+= IP flags
+~ IP
+
+pkt = IP(flags="MF")
+assert pkt.flags.MF
+assert not pkt.flags.DF
+assert not pkt.flags.evil
+
+pkt = IP(flags=3)
+assert pkt.flags.MF
+assert pkt.flags.DF
+assert not pkt.flags.evil
+
+= TCP flags
+~ TCP
+
+pkt = TCP(flags="SA")
+assert pkt.flags == 18
+assert pkt.flags.S
+assert pkt.flags.A
+assert not any(getattr(pkt.flags, f) for f in 'FRPUECN')
+
+pkt = TCP(flags=56)
+assert all(getattr(pkt.flags, f) for f in 'PAU')
+assert not any(getattr(pkt.flags, f) for f in 'FSRECN')
--
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