From 34164142b5fd6878cd487f531ae074e3227031ac Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 27 Oct 2025 12:29:58 -0700 Subject: [PATCH] tools: ynl: rework the string representation of NlError In early days of YNL development dumping the NlMsg on errors was quite useful, as the library itself could have been buggy. These days increasingly the NlMsg is just taking up screen space and means nothing to a typical user. Try to format the errors more in line with how YNL C formats its errors strings. Before: $ ynl --family ethtool --do channels-set --json '{}' Netlink error: Invalid argument nl_len = 44 (28) nl_flags = 0x300 nl_type = 2 error: -22 extack: {'miss-type': 'header'} $ ynl --family ethtool --do channels-set --json '{..., "tx-count": 999}' Netlink error: Invalid argument nl_len = 88 (72) nl_flags = 0x300 nl_type = 2 error: -22 extack: {'msg': 'requested channel count exceeds maximum', 'bad-attr': '.tx-count'} After: $ ynl --family ethtool --do channels-set --json '{}' Netlink error: Invalid argument {'miss-type': 'header'} $ ynl --family ethtool --do channels-set --json '{..., "tx-count": 999}' Netlink error: requested channel count exceeds maximum: Invalid argument {'bad-attr': '.tx-count'} Reviewed-by: Donald Hunter Link: https://patch.msgid.link/20251027192958.2058340-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- tools/net/ynl/pyynl/lib/ynl.py | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/tools/net/ynl/pyynl/lib/ynl.py b/tools/net/ynl/pyynl/lib/ynl.py index bdcc4f031d394..225baad3c8f8b 100644 --- a/tools/net/ynl/pyynl/lib/ynl.py +++ b/tools/net/ynl/pyynl/lib/ynl.py @@ -105,7 +105,16 @@ class NlError(Exception): self.error = -nl_msg.error def __str__(self): - return f"Netlink error: {os.strerror(self.error)}\n{self.nl_msg}" + msg = "Netlink error: " + + extack = self.nl_msg.extack.copy() if self.nl_msg.extack else {} + if 'msg' in extack: + msg += extack['msg'] + ': ' + del extack['msg'] + msg += os.strerror(self.error) + if extack: + msg += ' ' + str(extack) + return msg class ConfigError(Exception): -- 2.47.3