[PATCH net-next 3/4] ynl: replace print with NlError

[Stanislav Fomichev <sdf@google.com>]

Instead of dumping the error on the stdout, make the callee and
opportunity to decide what to do with it. This is mostly for the
ethtool testing.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 tools/net/ynl/lib/ynl.py | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 21c015911803..6c1a59cef957 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -67,6 +67,13 @@ from .nlspec import SpecFamily
     NLMSGERR_ATTR_MISS_NEST = 6
 
 
+class NlError(Exception):
+  def __init__(self, nl_msg):
+    self.nl_msg = nl_msg
+
+  def __str__(self):
+    return f"Netlink error: {os.strerror(-self.nl_msg.error)}\n{self.nl_msg}"
+
 class NlAttr:
     def __init__(self, raw, offset):
         self._len, self._type = struct.unpack("HH", raw[offset:offset + 4])
@@ -495,9 +502,7 @@ genl_family_name_to_id = None
                     self._decode_extack(msg, op.attr_set, nl_msg.extack)
 
                 if nl_msg.error:
-                    print("Netlink error:", os.strerror(-nl_msg.error))
-                    print(nl_msg)
-                    return
+                    raise NlError(nl_msg)
                 if nl_msg.done:
                     if nl_msg.extack:
                         print("Netlink warning:")
-- 
2.40.0.rc1.284.g88254d51c5-goog