From 17287069aac820fe01813fa673fb5227ae5dfc8b Mon Sep 17 00:00:00 2001
From: Max Chen <falay@users.noreply.github.com>
Date: Sat, 1 Oct 2022 05:34:22 +0800
Subject: [PATCH] Fixed TLV decoder issue (#22948)

* Fixed TLV decoder issue

Fixed issue of the TLV decoder:

When giving tlv_bytes = b"\0256\001\0255\001&\000\031\346x\2077\001$\002\001$\003\006$\004\000\030(\002\030\030\030\030", the following errors occur:

Traceback (most recent call last):
  File "/home/chingtzuchen/exp/tlv2.py", line 743, in <module>
    out = reader.get()
  File "/home/chingtzuchen/exp/tlv2.py", line 459, in get
    self._get(self._tlv, self._decodings, out)
  File "/home/chingtzuchen/exp/tlv2.py", line 674, in _get
    self._decodeVal(tlv, decoding)
  File "/home/chingtzuchen/exp/tlv2.py", line 574, in _decodeVal
    self._get(tlv, decoding["Structure"], decoding["value"])
  File "/home/chingtzuchen/exp/tlv2.py", line 674, in _get
    self._decodeVal(tlv, decoding)
  File "/home/chingtzuchen/exp/tlv2.py", line 578, in _decodeVal
    self._get(tlv, decoding["Array"], decoding["value"])
  File "/home/chingtzuchen/exp/tlv2.py", line 674, in _get
    self._decodeVal(tlv, decoding)
  File "/home/chingtzuchen/exp/tlv2.py", line 574, in _decodeVal
    self._get(tlv, decoding["Structure"], decoding["value"])
  File "/home/chingtzuchen/exp/tlv2.py", line 674, in _get
    self._decodeVal(tlv, decoding)
  File "/home/chingtzuchen/exp/tlv2.py", line 574, in _decodeVal
    self._get(tlv, decoding["Structure"], decoding["value"])
  File "/home/chingtzuchen/exp/tlv2.py", line 674, in _get
    self._decodeVal(tlv, decoding)
  File "/home/chingtzuchen/exp/tlv2.py", line 582, in _decodeVal
    self._get(tlv, decoding["Path"], decoding["value"])
  File "/home/chingtzuchen/exp/tlv2.py", line 685, in _get
    out[decoding["tag"]] = decoding["value"]
IndexError: list assignment index out of range

Added condition and made it more clean to fix the issue, after this fix the bytes can be decoded:

{'Any': {1: [{1: {'Any': 2272847385, 1: [1, 6, 0], 2: False}}]}}

* Update __init__.py

* Add unit test case

Add unit test case for structure TLV bytes input

Test result:

```
$ python test_tlv.py
.....
----------------------------------------------------------------------
Ran 5 tests in 0.000s

OK
```

* Update test_tlv.py

Update style
---
 src/controller/python/chip/tlv/__init__.py        | 10 ++++------
 src/controller/python/test/unit_tests/test_tlv.py | 12 ++++++++++++
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/controller/python/chip/tlv/__init__.py b/src/controller/python/chip/tlv/__init__.py
index 20f2bfebd2f2dd..5665c5e2a4f46b 100644
--- a/src/controller/python/chip/tlv/__init__.py
+++ b/src/controller/python/chip/tlv/__init__.py
@@ -680,13 +680,11 @@ def _get(self, tlv, decodings, out):
                 if "profileTag" in list(decoding.keys()):
                     out[decoding["profileTag"]] = decoding["value"]
                 elif "tag" in list(decoding.keys()):
-                    if decoding["tag"] is not None:
-                        out[decoding["tag"]] = decoding["value"]
+                    if isinstance(out, Mapping):
+                        tag = decoding["tag"] if decoding["tag"] is not None else "Any"
+                        out[tag] = decoding["value"]
                     else:
-                        if isinstance(out, Mapping):
-                            out["Any"] = decoding["value"]
-                        elif isinstance(out, Sequence):
-                            out.append(decoding["value"])
+                        out.append(decoding["value"])
                 else:
                     raise ValueError("Attempt to decode unsupported TLV tag")
 
diff --git a/src/controller/python/test/unit_tests/test_tlv.py b/src/controller/python/test/unit_tests/test_tlv.py
index 7e83f9c26863f2..901197b4ea4742 100644
--- a/src/controller/python/test/unit_tests/test_tlv.py
+++ b/src/controller/python/test/unit_tests/test_tlv.py
@@ -148,6 +148,18 @@ def test_uint(self):
         self._read_case([0b00000101, 0xab, 0xaa], tlvUint(0xaaab))
         self._read_case([0b00000100, 0xab], tlvUint(0xab))
 
+    def test_structure(self):
+        test_cases = [
+            (b'\x15\x36\x01\x15\x35\x01\x26\x00\xBF\xA2\x55\x16\x37\x01\x24\x02\x00\x24\x03\x28\x24\x04\x00\x18\x24\x02\x01\x18\x18\x18\x18',
+             {1: [{1: {0: 374710975, 1: [0, 40, 0], 2: 1}}]}),
+            (b'\x156\x01\x155\x01&\x00\xBF\xA2U\x167\x01$\x02\x00$\x03($\x04\x01\x18,\x02\x18Nordic Semiconductor ASA\x18\x18\x18\x18',
+             {1: [{1: {0: 374710975, 1: [0, 40, 1], 2: 'Nordic Semiconductor ASA'}}]}),
+            (b"\0256\001\0255\001&\000\031\346x\2077\001$\002\001$\003\006$\004\000\030(\002\030\030\030\030",
+             {1: [{1: {0: 2272847385, 1: [1, 6, 0], 2: False}}]})
+        ]
+        for tlv_bytes, answer in test_cases:
+            self._read_case(tlv_bytes, answer)
+
 
 if __name__ == '__main__':
     unittest.main()