netdev - Re: [PATCH net 2/2] net: enhance error message for 'netns local' iface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0c1499c1-565c-4b11-98e7-6b12c1e04081@6wind.com>
Date: Fri, 7 Feb 2025 10:08:09 +0100
From: Nicolas Dichtel <nicolas.dichtel@...nd.com>
To: Andrew Lunn <andrew@...n.ch>
Cc: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski
 <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
 Eric Dumazet <edumazet@...gle.com>,
 Alexander Lobakin <aleksander.lobakin@...el.com>, netdev@...r.kernel.org
Subject: Re: [PATCH net 2/2] net: enhance error message for 'netns local'
 iface

Le 07/02/2025 à 00:02, Andrew Lunn a écrit :
> On Thu, Feb 06, 2025 at 05:50:27PM +0100, Nicolas Dichtel wrote:
>> The current message is "Invalid argument". Let's help the user by
>> explaining the error.
>>
>> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@...nd.com>
>> ---
>>  net/core/rtnetlink.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
>> index 5032e65b8faa..91b358bdfe5c 100644
>> --- a/net/core/rtnetlink.c
>> +++ b/net/core/rtnetlink.c
>> @@ -3024,8 +3024,12 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev,
>>  		new_ifindex = nla_get_s32_default(tb[IFLA_NEW_IFINDEX], 0);
>>  
>>  		err = __dev_change_net_namespace(dev, tgt_net, pat, new_ifindex);
>> -		if (err)
>> +		if (err) {
>> +			if (dev->netns_local)
>> +				NL_SET_ERR_MSG(extack,
>> +					       "The interface has the 'netns local' property");
> 
> This seems to have the wrong order. Why even try calling
> __dev_change_net_namespace() if you know it is going to fail?
> 
> Maybe this NL_SET_ERR_MSG() should be pushed into
> __dev_change_net_namespace()? You could then return useful messages if
> the altnames conflict, the ifindex is already in use, etc.
Users of dev_change_net_namespace() are not netlink users, so I kept the same
API. I will plumb the extack into __dev_change_net_namespace().


Thanks,
Nicolas