fixeria has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmocom-bb/+/23136 )
Change subject: trx_toolkit/codec.py: implement check() API for Envelope
......................................................................
trx_toolkit/codec.py: implement check() API for Envelope
Change-Id: I8258504493cf85c401677866fe8474de2e49786b
Related: OS#4006, SYS#4895
---
M src/target/trx_toolkit/codec.py
M src/target/trx_toolkit/test_codec.py
2 files changed, 28 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/36/23136/1
diff --git a/src/target/trx_toolkit/codec.py b/src/target/trx_toolkit/codec.py
index e3cd600..cc3b5ed 100644
--- a/src/target/trx_toolkit/codec.py
+++ b/src/target/trx_toolkit/codec.py
@@ -271,6 +271,15 @@
def __delitem__(self, key: str) -> None:
del self.content[key]
+ def check(self) -> None:
+ ''' Check the content before encoding and after decoding.
+ Raise exceptions (e.g. ValueError) if something is wrong.
+
+ Do not assert for every possible error (e.g. a negative
value
+ for a Uint field) if an exception will be thrown by the
field's
+ to_bytes() method anyway. Only additional constraints here.
+ '''
+
def from_bytes(self, data: bytes, offset: int = 0) -> int:
self.content = { } # forget the old content
try: # Fields throw exceptions
@@ -282,6 +291,7 @@
if self.check_len and len(data) != offset:
raise DecodeError(self, 'Unhandled tail octets: %s'
% data[offset:].hex())
+ self.check() # Check the content after decoding (raises
exceptions)
return offset
def to_bytes(self) -> bytes:
@@ -291,4 +301,5 @@
except Exception as e:
# Add contextual info
raise EncodeError(self, f) from e
+ self.check() # Check the content before encoding (raises
exceptions)
return b''.join([proc(f) for f in self.STRUCT])
diff --git a/src/target/trx_toolkit/test_codec.py
b/src/target/trx_toolkit/test_codec.py
index 0499f3a..287be92 100644
--- a/src/target/trx_toolkit/test_codec.py
+++ b/src/target/trx_toolkit/test_codec.py
@@ -419,6 +419,10 @@
self.STRUCT[-1].get_pres_dec = lambda v, _: bool(v['flag'])
self.STRUCT[-1].get_pres_enc = lambda v: bool(v['flag'])
+ def check(self) -> None:
+ if not self['ver'] in (0, 1, 2):
+ raise ValueError('Unknown version %d' % self['ver'])
+
class Envelope(unittest.TestCase):
def test_rest_octets(self):
pdu = TestPDU(check_len=False)
@@ -467,5 +471,18 @@
pdu.from_bytes(b'\x28\x00\x00\x01\xf0\xbe\xed')
self.assertEqual(pdu.content, content)
+ def test_to_bytes_check(self):
+ pdu = TestPDU()
+
+ pdu.content = { 'ver' : 8, 'flag' : 1, 'data' : b'', 'tail' :
b'\xde\xbe' }
+ with self.assertRaises(ValueError):
+ pdu.to_bytes()
+
+ def test_from_bytes_check(self):
+ pdu = TestPDU()
+
+ with self.assertRaises(ValueError):
+ pdu.from_bytes(b'\xf0\x00\x00\x00')
+
if __name__ == '__main__':
unittest.main()
--
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: I8258504493cf85c401677866fe8474de2e49786b
Gerrit-Change-Number: 23136
Gerrit-PatchSet: 1
Gerrit-Owner: fixeria <[email protected]>
Gerrit-MessageType: newchange
