[PATCH net-next v1 03/13] tools: ynl: fix pylint exception warnings

[Donald Hunter <donald.hunter@gmail.com>]

Fix pylint warnings for:

- broad-exception-raised
- broad-exception-caught
- raise-missing-from

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
---
 tools/net/ynl/pyynl/cli.py          |  6 +--
 tools/net/ynl/pyynl/lib/__init__.py |  8 ++--
 tools/net/ynl/pyynl/lib/nlspec.py   | 11 ++++--
 tools/net/ynl/pyynl/lib/ynl.py      | 59 +++++++++++++++++------------
 4 files changed, 50 insertions(+), 34 deletions(-)

diff --git a/tools/net/ynl/pyynl/cli.py b/tools/net/ynl/pyynl/cli.py
index 41c20162f951..5fee45e48bbf 100755
--- a/tools/net/ynl/pyynl/cli.py
+++ b/tools/net/ynl/pyynl/cli.py
@@ -15,7 +15,7 @@ import textwrap
 
 # pylint: disable=no-name-in-module,wrong-import-position
 sys.path.append(pathlib.Path(__file__).resolve().parent.as_posix())
-from lib import YnlFamily, Netlink, NlError, SpecFamily
+from lib import YnlFamily, Netlink, NlError, SpecFamily, SpecException, YnlException
 
 SYS_SCHEMA_DIR='/usr/share/ynl'
 RELATIVE_SCHEMA_DIR='../../../../Documentation/netlink'
@@ -189,12 +189,12 @@ def main():
     else:
         spec = args.spec
     if not os.path.isfile(spec):
-        raise Exception(f"Spec file {spec} does not exist")
+        raise YnlException(f"Spec file {spec} does not exist")
 
     if args.validate:
         try:
             SpecFamily(spec, args.schema)
-        except Exception as error:
+        except SpecException as error:
             print(error)
             sys.exit(1)
         return
diff --git a/tools/net/ynl/pyynl/lib/__init__.py b/tools/net/ynl/pyynl/lib/__init__.py
index c40dd788fe8a..33a96155fb3b 100644
--- a/tools/net/ynl/pyynl/lib/__init__.py
+++ b/tools/net/ynl/pyynl/lib/__init__.py
@@ -3,11 +3,13 @@
 """ YNL library """
 
 from .nlspec import SpecAttr, SpecAttrSet, SpecEnumEntry, SpecEnumSet, \
-    SpecFamily, SpecOperation, SpecSubMessage, SpecSubMessageFormat
-from .ynl import YnlFamily, Netlink, NlError
+    SpecFamily, SpecOperation, SpecSubMessage, SpecSubMessageFormat, \
+    SpecException
+from .ynl import YnlFamily, Netlink, NlError, YnlException
 
 from .doc_generator import YnlDocGenerator
 
 __all__ = ["SpecAttr", "SpecAttrSet", "SpecEnumEntry", "SpecEnumSet",
            "SpecFamily", "SpecOperation", "SpecSubMessage", "SpecSubMessageFormat",
-           "YnlFamily", "Netlink", "NlError", "YnlDocGenerator"]
+           "SpecException",
+           "YnlFamily", "Netlink", "NlError", "YnlDocGenerator", "YnlException"]
diff --git a/tools/net/ynl/pyynl/lib/nlspec.py b/tools/net/ynl/pyynl/lib/nlspec.py
index c3113952c417..a35f827f09e3 100644
--- a/tools/net/ynl/pyynl/lib/nlspec.py
+++ b/tools/net/ynl/pyynl/lib/nlspec.py
@@ -17,6 +17,11 @@ import yaml as pyyaml
 jsonschema = None
 
 
+class SpecException(Exception):
+    """Netlink spec exception.
+    """
+
+
 class SpecElement:
     """Netlink spec element.
 
@@ -385,7 +390,7 @@ class SpecOperation(SpecElement):
         elif self.is_resv:
             attr_set_name = ''
         else:
-            raise Exception(f"Can't resolve attribute set for op '{self.name}'")
+            raise SpecException(f"Can't resolve attribute set for op '{self.name}'")
         if attr_set_name:
             self.attr_set = self.family.attr_sets[attr_set_name]
 
@@ -440,7 +445,7 @@ class SpecFamily(SpecElement):
             prefix = '# SPDX-License-Identifier: '
             first = stream.readline().strip()
             if not first.startswith(prefix):
-                raise Exception('SPDX license tag required in the spec')
+                raise SpecException('SPDX license tag required in the spec')
             self.license = first[len(prefix):]
 
             stream.seek(0)
@@ -555,7 +560,7 @@ class SpecFamily(SpecElement):
                 req_val_next = req_val + 1
                 rsp_val_next = rsp_val + rsp_inc
             else:
-                raise Exception("Can't parse directional ops")
+                raise SpecException("Can't parse directional ops")
 
             if req_val == req_val_next:
                 req_val = None
diff --git a/tools/net/ynl/pyynl/lib/ynl.py b/tools/net/ynl/pyynl/lib/ynl.py
index 8689ad25055b..97229330c6c9 100644
--- a/tools/net/ynl/pyynl/lib/ynl.py
+++ b/tools/net/ynl/pyynl/lib/ynl.py
@@ -32,6 +32,10 @@ from .nlspec import SpecFamily
 #
 
 
+class YnlException(Exception):
+    pass
+
+
 # pylint: disable=too-few-public-methods
 class Netlink:
     # Netlink socket
@@ -167,7 +171,7 @@ class NlAttr:
 
     def as_auto_scalar(self, attr_type, byte_order=None):
         if len(self.raw) != 4 and len(self.raw) != 8:
-            raise Exception(f"Auto-scalar len payload be 4 or 8 bytes, got {len(self.raw)}")
+            raise YnlException(f"Auto-scalar len payload be 4 or 8 bytes, got {len(self.raw)}")
         real_type = attr_type[0] + str(len(self.raw) * 8)
         format_ = self.get_format(real_type, byte_order)
         return format_.unpack(self.raw)[0]
@@ -425,7 +429,7 @@ class NetlinkProtocol:
 
     def get_mcast_id(self, mcast_name, mcast_groups):
         if mcast_name not in mcast_groups:
-            raise Exception(f'Multicast group "{mcast_name}" not present in the spec')
+            raise YnlException(f'Multicast group "{mcast_name}" not present in the spec')
         return mcast_groups[mcast_name].value
 
     def msghdr_size(self):
@@ -453,7 +457,7 @@ class GenlProtocol(NetlinkProtocol):
 
     def get_mcast_id(self, mcast_name, mcast_groups):
         if mcast_name not in self.genl_family['mcast']:
-            raise Exception(f'Multicast group "{mcast_name}" not present in the family')
+            raise YnlException(f'Multicast group "{mcast_name}" not present in the family')
         return self.genl_family['mcast'][mcast_name]
 
     def msghdr_size(self):
@@ -475,9 +479,9 @@ class SpaceAttrs:
                 if name in scope.values:
                     return scope.values[name]
                 spec_name = scope.spec.yaml['name']
-                raise Exception(
+                raise YnlException(
                     f"No value for '{name}' in attribute space '{spec_name}'")
-        raise Exception(f"Attribute '{name}' not defined in any attribute-set")
+        raise YnlException(f"Attribute '{name}' not defined in any attribute-set")
 
 
 #
@@ -499,8 +503,8 @@ class YnlFamily(SpecFamily):
                                                self.yaml['protonum'])
             else:
                 self.nlproto = GenlProtocol(self.yaml['name'])
-        except KeyError:
-            raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel")
+        except KeyError as err:
+            raise YnlException(f"Family '{self.yaml['name']}' not supported by the kernel") from err
 
         self._recv_dbg = False
         # Note that netlink will use conservative (min) message size for
@@ -573,8 +577,8 @@ class YnlFamily(SpecFamily):
     def _add_attr(self, space, name, value, search_attrs):
         try:
             attr = self.attr_sets[space][name]
-        except KeyError:
-            raise Exception(f"Space '{space}' has no attribute '{name}'")
+        except KeyError as err:
+            raise YnlException(f"Space '{space}' has no attribute '{name}'") from err
         nl_type = attr.value
 
         if attr.is_multi and isinstance(value, list):
@@ -615,7 +619,7 @@ class YnlFamily(SpecFamily):
                 format_ = NlAttr.get_format(attr.sub_type)
                 attr_payload = b''.join([format_.pack(x) for x in value])
             else:
-                raise Exception(f'Unknown type for binary attribute, value: {value}')
+                raise YnlException(f'Unknown type for binary attribute, value: {value}')
         elif attr['type'] in NlAttr.type_formats or attr.is_auto_scalar:
             scalar = self._get_scalar(attr, value)
             if attr.is_auto_scalar:
@@ -641,9 +645,9 @@ class YnlFamily(SpecFamily):
                         attr_payload += self._add_attr(msg_format.attr_set,
                                                        subname, subvalue, sub_attrs)
                 else:
-                    raise Exception(f"Unknown attribute-set '{msg_format.attr_set}'")
+                    raise YnlException(f"Unknown attribute-set '{msg_format.attr_set}'")
         else:
-            raise Exception(f'Unknown type at {space} {name} {value} {attr["type"]}')
+            raise YnlException(f'Unknown type at {space} {name} {value} {attr["type"]}')
 
         return self._add_attr_raw(nl_type, attr_payload)
 
@@ -730,7 +734,7 @@ class YnlFamily(SpecFamily):
                     subattr = self._formatted_string(subattr, attr_spec.display_hint)
                 decoded.append(subattr)
             else:
-                raise Exception(f'Unknown {attr_spec["sub-type"]} with name {attr_spec["name"]}')
+                raise YnlException(f'Unknown {attr_spec["sub-type"]} with name {attr_spec["name"]}')
         return decoded
 
     def _decode_nest_type_value(self, attr, attr_spec):
@@ -767,13 +771,13 @@ class YnlFamily(SpecFamily):
     def _resolve_selector(self, attr_spec, search_attrs):
         sub_msg = attr_spec.sub_message
         if sub_msg not in self.sub_msgs:
-            raise Exception(f"No sub-message spec named {sub_msg} for {attr_spec.name}")
+            raise YnlException(f"No sub-message spec named {sub_msg} for {attr_spec.name}")
         sub_msg_spec = self.sub_msgs[sub_msg]
 
         selector = attr_spec.selector
         value = search_attrs.lookup(selector)
         if value not in sub_msg_spec.formats:
-            raise Exception(f"No message format for '{value}' in sub-message spec '{sub_msg}'")
+            raise YnlException(f"No message format for '{value}' in sub-message spec '{sub_msg}'")
 
         spec = sub_msg_spec.formats[value]
         return spec, value
@@ -790,7 +794,8 @@ class YnlFamily(SpecFamily):
                 subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set)
                 decoded.update(subdict)
             else:
-                raise Exception(f"Unknown attribute-set '{msg_format.attr_set}' when decoding '{attr_spec.name}'")
+                raise YnlException(f"Unknown attribute-set '{msg_format.attr_set}' "
+                                   f"when decoding '{attr_spec.name}'")
         return decoded
 
     # pylint: disable=too-many-statements
@@ -803,9 +808,10 @@ class YnlFamily(SpecFamily):
         for attr in attrs:
             try:
                 attr_spec = attr_space.attrs_by_val[attr.type]
-            except (KeyError, UnboundLocalError):
+            except (KeyError, UnboundLocalError) as err:
                 if not self.process_unknown:
-                    raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")
+                    raise YnlException(f"Space '{space}' has no attribute "
+                                       f"with value '{attr.type}'") from err
                 attr_name = f"UnknownAttr({attr.type})"
                 self._rsp_add(rsp, attr_name, None, self._decode_unknown(attr))
                 continue
@@ -844,7 +850,8 @@ class YnlFamily(SpecFamily):
                     decoded = self._decode_nest_type_value(attr, attr_spec)
                 else:
                     if not self.process_unknown:
-                        raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')
+                        raise YnlException(f'Unknown {attr_spec["type"]} '
+                                           f'with name {attr_spec["name"]}')
                     decoded = self._decode_unknown(attr)
 
                 self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)
@@ -859,8 +866,9 @@ class YnlFamily(SpecFamily):
         for attr in attrs:
             try:
                 attr_spec = attr_set.attrs_by_val[attr.type]
-            except KeyError:
-                raise Exception(f"Space '{attr_set.name}' has no attribute with value '{attr.type}'")
+            except KeyError as err:
+                raise YnlException(
+                    f"Space '{attr_set.name}' has no attribute with value '{attr.type}'") from err
             if offset > target:
                 break
             if offset == target:
@@ -877,11 +885,12 @@ class YnlFamily(SpecFamily):
             elif attr_spec['type'] == 'sub-message':
                 msg_format, value = self._resolve_selector(attr_spec, search_attrs)
                 if msg_format is None:
-                    raise Exception(f"Can't resolve sub-message of {attr_spec['name']} for extack")
+                    raise YnlException(f"Can't resolve sub-message of "
+                                       f"{attr_spec['name']} for extack")
                 sub_attrs = self.attr_sets[msg_format.attr_set]
                 pathname += f"({value})"
             else:
-                raise Exception(f"Can't dive into {attr.type} ({attr_spec['name']}) for extack")
+                raise YnlException(f"Can't dive into {attr.type} ({attr_spec['name']}) for extack")
             offset += 4
             subpath = self._decode_extack_path(NlAttrs(attr.raw), sub_attrs,
                                                offset, target, search_attrs)
@@ -1008,11 +1017,11 @@ class YnlFamily(SpecFamily):
                 mac_bytes = [int(x, 16) for x in string.split(':')]
             else:
                 if len(string) % 2 != 0:
-                    raise Exception(f"Invalid MAC address format: {string}")
+                    raise YnlException(f"Invalid MAC address format: {string}")
                 mac_bytes = [int(string[i:i+2], 16) for i in range(0, len(string), 2)]
             raw = bytes(mac_bytes)
         else:
-            raise Exception(f"Display hint '{attr_spec.display_hint}' not implemented"
+            raise YnlException(f"Display hint '{attr_spec.display_hint}' not implemented"
                             f" when parsing '{attr_spec['name']}'")
         return raw
 
-- 
2.52.0