diff mbox series

[net-next,2/3] tools: ynl: print some information about attribute we can't parse

Message ID 20250105012523.1722231-3-kuba@kernel.org (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series tools: ynl: decode link types present in tests | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl fail Tree is dirty after regen; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success Errors and warnings before: 0 (+23) this patch: 0 (+23)
netdev/cc_maintainers warning 2 maintainers not CCed: jiri@resnulli.us horms@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 80 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-01-05--09-00 (tests: 887)

Commit Message

Jakub Kicinski Jan. 5, 2025, 1:25 a.m. UTC
When parsing throws an exception one often has to figure out which
attribute couldn't be parsed from first principles. For families
with large message parsing trees like rtnetlink guessing the
attribute can be hard.

Print a bit of information as the exception travels out, e.g.:

  # when dumping rt links
  Error decoding 'flags' from 'linkinfo-ip6tnl-attrs'
  Error decoding 'data' from 'linkinfo-attrs'
  Error decoding 'linkinfo' from 'link-attrs'
  Traceback (most recent call last):
    File "/home/kicinski/linux/./tools/net/ynl/cli.py", line 119, in <module>
      main()
    File "/home/kicinski/linux/./tools/net/ynl/cli.py", line 100, in main
      reply = ynl.dump(args.dump, attrs)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1064, in dump
      return self._op(method, vals, dump=True)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1058, in _op
      return self._ops(ops)[0]
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1045, in _ops
      rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 738, in _decode
      subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 763, in _decode
      decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 714, in _decode_sub_msg
      subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 749, in _decode
      decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
    File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 147, in as_scalar
      return format.unpack(self.raw)[0]
  struct.error: unpack requires a buffer of 2 bytes

The Traceback is what we would previously see, the "Error..."
messages are new. We print a message per level (in the stack
order). Printing single combined message gets tricky quickly
given sub-messages etc.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/net/ynl/lib/ynl.py | 72 +++++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 34 deletions(-)

Comments

Donald Hunter Jan. 6, 2025, 1:30 p.m. UTC | #1
Jakub Kicinski <kuba@kernel.org> writes:

> When parsing throws an exception one often has to figure out which
> attribute couldn't be parsed from first principles. For families
> with large message parsing trees like rtnetlink guessing the
> attribute can be hard.
>
> Print a bit of information as the exception travels out, e.g.:
>
>   # when dumping rt links
>   Error decoding 'flags' from 'linkinfo-ip6tnl-attrs'
>   Error decoding 'data' from 'linkinfo-attrs'
>   Error decoding 'linkinfo' from 'link-attrs'
>   Traceback (most recent call last):
>     File "/home/kicinski/linux/./tools/net/ynl/cli.py", line 119, in <module>
>       main()
>     File "/home/kicinski/linux/./tools/net/ynl/cli.py", line 100, in main
>       reply = ynl.dump(args.dump, attrs)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1064, in dump
>       return self._op(method, vals, dump=True)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1058, in _op
>       return self._ops(ops)[0]
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 1045, in _ops
>       rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 738, in _decode
>       subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 763, in _decode
>       decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 714, in _decode_sub_msg
>       subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 749, in _decode
>       decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
>     File "/home/kicinski/linux/tools/net/ynl/lib/ynl.py", line 147, in as_scalar
>       return format.unpack(self.raw)[0]
>   struct.error: unpack requires a buffer of 2 bytes
>
> The Traceback is what we would previously see, the "Error..."
> messages are new. We print a message per level (in the stack
> order). Printing single combined message gets tricky quickly
> given sub-messages etc.
>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
diff mbox series

Patch

diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index eea29359a899..08f8bf89cfc2 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -733,41 +733,45 @@  genl_family_name_to_id = None
                 self._rsp_add(rsp, attr_name, None, self._decode_unknown(attr))
                 continue
 
-            if attr_spec["type"] == 'nest':
-                subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
-                decoded = subdict
-            elif attr_spec["type"] == 'string':
-                decoded = attr.as_strz()
-            elif attr_spec["type"] == 'binary':
-                decoded = self._decode_binary(attr, attr_spec)
-            elif attr_spec["type"] == 'flag':
-                decoded = True
-            elif attr_spec.is_auto_scalar:
-                decoded = attr.as_auto_scalar(attr_spec['type'], attr_spec.byte_order)
-            elif attr_spec["type"] in NlAttr.type_formats:
-                decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
-                if 'enum' in attr_spec:
-                    decoded = self._decode_enum(decoded, attr_spec)
-                elif attr_spec.display_hint:
-                    decoded = self._formatted_string(decoded, attr_spec.display_hint)
-            elif attr_spec["type"] == 'indexed-array':
-                decoded = self._decode_array_attr(attr, attr_spec)
-            elif attr_spec["type"] == 'bitfield32':
-                value, selector = struct.unpack("II", attr.raw)
-                if 'enum' in attr_spec:
-                    value = self._decode_enum(value, attr_spec)
-                    selector = self._decode_enum(selector, attr_spec)
-                decoded = {"value": value, "selector": selector}
-            elif attr_spec["type"] == 'sub-message':
-                decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
-            elif attr_spec["type"] == 'nest-type-value':
-                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"]}')
-                decoded = self._decode_unknown(attr)
+            try:
+                if attr_spec["type"] == 'nest':
+                    subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
+                    decoded = subdict
+                elif attr_spec["type"] == 'string':
+                    decoded = attr.as_strz()
+                elif attr_spec["type"] == 'binary':
+                    decoded = self._decode_binary(attr, attr_spec)
+                elif attr_spec["type"] == 'flag':
+                    decoded = True
+                elif attr_spec.is_auto_scalar:
+                    decoded = attr.as_auto_scalar(attr_spec['type'], attr_spec.byte_order)
+                elif attr_spec["type"] in NlAttr.type_formats:
+                    decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
+                    if 'enum' in attr_spec:
+                        decoded = self._decode_enum(decoded, attr_spec)
+                    elif attr_spec.display_hint:
+                        decoded = self._formatted_string(decoded, attr_spec.display_hint)
+                elif attr_spec["type"] == 'indexed-array':
+                    decoded = self._decode_array_attr(attr, attr_spec)
+                elif attr_spec["type"] == 'bitfield32':
+                    value, selector = struct.unpack("II", attr.raw)
+                    if 'enum' in attr_spec:
+                        value = self._decode_enum(value, attr_spec)
+                        selector = self._decode_enum(selector, attr_spec)
+                    decoded = {"value": value, "selector": selector}
+                elif attr_spec["type"] == 'sub-message':
+                    decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
+                elif attr_spec["type"] == 'nest-type-value':
+                    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"]}')
+                    decoded = self._decode_unknown(attr)
 
-            self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)
+                self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)
+            except:
+                print(f"Error decoding '{attr_spec.name}' from '{space}'")
+                raise
 
         return rsp