laforge has uploaded this change for review. (
https://gerrit.osmocom.org/c/pysim/+/33249 )
Change subject: 31.102: Fix EF.Routing_Indicator for odd number of digits
......................................................................
31.102: Fix EF.Routing_Indicator for odd number of digits
The routing indicator is BCD-encoded but has an arbitrary length of
1, 2, 3 or 4 digits.
In order to support the odd lengths of 1 or 3, we must not pad on the
byte level, but on the nibble level. This requires a slight extension of
the Rpad() Adapter.
Change-Id: I6c26dccdd570de7b7a4cd48338068e230340ec7c
Fixes: OS#6054
---
M pySim/construct.py
M pySim/ts_31_102.py
2 files changed, 28 insertions(+), 7 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/49/33249/1
diff --git a/pySim/construct.py b/pySim/construct.py
index 20a6946..ab44a63 100644
--- a/pySim/construct.py
+++ b/pySim/construct.py
@@ -66,26 +66,29 @@
class Rpad(Adapter):
"""
- Encoder appends padding bytes (b'\\xff') up to target size.
- Decoder removes trailing padding bytes.
+ Encoder appends padding bytes (b'\\xff') or characters up to target size.
+ Decoder removes trailing padding bytes/characters.
Parameters:
subcon: Subconstruct as defined by construct library
pattern: set padding pattern (default: b'\\xff')
+ num_per_byte: number of 'elements' per byte. E.g. for hex nibbles: 2
"""
- def __init__(self, subcon, pattern=b'\xff'):
+ def __init__(self, subcon, pattern=b'\xff', num_per_byte=1):
super().__init__(subcon)
self.pattern = pattern
+ self.num_per_byte = num_per_byte
def _decode(self, obj, context, path):
return obj.rstrip(self.pattern)
def _encode(self, obj, context, path):
- if len(obj) > self.sizeof():
+ target_size = self.sizeof() * self.num_per_byte
+ if len(obj) > target_size:
raise SizeofError("Input ({}) exceeds target size ({})".format(
- len(obj), self.sizeof()))
- return obj + self.pattern * (self.sizeof() - len(obj))
+ len(obj), target_size))
+ return obj + self.pattern * (target_size - len(obj))
class MultiplyAdapter(Adapter):
"""
diff --git a/pySim/ts_31_102.py b/pySim/ts_31_102.py
index 81b671e..e7ae8f0 100644
--- a/pySim/ts_31_102.py
+++ b/pySim/ts_31_102.py
@@ -1089,7 +1089,8 @@
# responsibility of home network operator but BCD coding shall be
used. If a network
# operator decides to assign less than 4 digits to Routing Indicator,
the remaining digits
# shall be coded as "1111" to fill the 4 digits coding of Routing
Indicator
- self._construct =
Struct('routing_indicator'/BcdAdapter(Rpad(Bytes(2))),
'rfu'/HexAdapter(Bytes(2)))
+ self._construct =
Struct('routing_indicator'/Rpad(BcdAdapter(Bytes(2)), 'f', 2),
+ 'rfu'/HexAdapter(Bytes(2)))
# TS 31.102 Section 4.4.11.13
class EF_TN3GPPSNN(TransparentEF):
--
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Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: I6c26dccdd570de7b7a4cd48338068e230340ec7c
Gerrit-Change-Number: 33249
Gerrit-PatchSet: 1
Gerrit-Owner: laforge <lafo...@osmocom.org>
Gerrit-MessageType: newchange
