From 1d1768bb80b6c23361f91fa65b5a2e496c715c37 Mon Sep 17 00:00:00 2001
From: Phil <phil@secdev.org>
Date: Thu, 14 Aug 2008 02:09:49 +0200
Subject: [PATCH] Renamed FloatField into FixedPointField and fixed it
(inspired by wam patch, ticket #119)
---
scapy/fields.py | 29 +++++++++++++++++++----------
scapy/layers/ntp.py | 4 ++--
2 files changed, 21 insertions(+), 12 deletions(-)
diff --git a/scapy/fields.py b/scapy/fields.py
index cb8bbbf4..4ea72db7 100644
--- a/scapy/fields.py
+++ b/scapy/fields.py
@@ -803,13 +803,22 @@ class FlagsField(BitField):
-class FloatField(BitField):
- def getfield(self, pkt, s):
- s,b = BitField.getfield(self, pkt, s)
-
- # fraction point between bits 15 and 16.
- sec = b >> 16
- frac = b & (1L << (32+1)) - 1
- frac /= 65536.0
- b = sec+frac
- return s,b
+class FixedPointField(BitField):
+ def __init__(self, name, default, size, frac_bits=16):
+ self.frac_bits = frac_bits
+ BitField.__init__(self, name, default, size)
+
+ def any2i(self, pkt, val):
+ if val is None:
+ return val
+ ival = int(val)
+ fract = int( (val-ival) * 2**self.frac_bits )
+ return (ival << self.frac_bits) | fract
+
+ def i2h(self, pkt, val):
+ int_part = val >> self.frac_bits
+ frac_part = val & (1L << self.frac_bits) - 1
+ frac_part /= 2.0**self.frac_bits
+ return int_part+frac_part
+ def i2repr(self, pkt, val):
+ return self.i2h(pkt, val)
diff --git a/scapy/layers/ntp.py b/scapy/layers/ntp.py
index bd143483..996d1727 100644
--- a/scapy/layers/ntp.py
+++ b/scapy/layers/ntp.py
@@ -67,8 +67,8 @@ class NTP(Packet):
BitField('stratum', 2, 8),
BitField('poll', 0xa, 8), ### XXX : it's a signed int
BitField('precision', 0, 8), ### XXX : it's a signed int
- FloatField('delay', 0, 32),
- FloatField('dispersion', 0, 32),
+ FixedPointField('delay', 0, size=32, frac_bits=16),
+ FixedPointField('dispersion', 0, size=32, frac_bits=16),
IPField('id', "127.0.0.1"),
TimeStampField('ref', 0, 64),
TimeStampField('orig', -1, 64), # -1 means current time
--
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