From: David Miller <davem@davemloft.net>
To: michellammertink@gmail.com
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH] netlink: fix append of whole original message on negative ack.
Date: Thu, 23 Oct 2008 13:45:13 -0700 (PDT) [thread overview]
Message-ID: <20081023.134513.267548182.davem@davemloft.net> (raw)
In-Reply-To: <4900BFCF.2030707@gmail.com>
From: M Lammertink <michellammertink@gmail.com>
Date: Thu, 23 Oct 2008 20:17:51 +0200
You'll get a much better review of this if you send it to
the netdev mailing list, which is where all the networking
developers are subscribed. They don't read linux-kernel
Added to CC:
> From: Michel Lammertink <mlammertink <at> ti-wmc.nl>
> Signed-off-by: Michel Lammertink <mlammertink <at> ti-wmc.nl>
>
> Netlink can return an negative acknowledgement, which AFAICT should include an error code and the whole original message. This patch fixes the size argument given to the __nlmsg_put call. Without this patch only the original header was attached.
> ---
>
> Can anyone explain to me why struct nlmsgerr contains an int error and the nlmsghdr struct. The comment in netlink_ack states that the whole message should be appended. Why not only include an int error in struct nlmsgerr and just append the original message?
>
> Comments appreciated.
>
> diff -uprN linux-2.6.27.3.orig/net/netlink/af_netlink.c linux-2.6.27.3/net/netlink/af_netlink.c
> --- linux-2.6.27.3.orig/net/netlink/af_netlink.c 2008-10-23 18:01:54.000000000 +0200
> +++ linux-2.6.27.3/net/netlink/af_netlink.c 2008-10-23 18:04:22.000000000 +0200
> @@ -1656,7 +1656,7 @@ void netlink_ack(struct sk_buff *in_skb,
> }
>
> rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
> - NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
> + NLMSG_ERROR, payload, 0);
> errmsg = nlmsg_data(rep);
> errmsg->error = err;
> memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
> --
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next parent reply other threads:[~2008-10-23 20:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4900BFCF.2030707@gmail.com>
2008-10-23 20:45 ` David Miller [this message]
2008-10-23 20:55 ` [PATCH] netlink: fix append of whole original message on negative ack Evgeniy Polyakov
2008-10-23 21:02 ` Patrick McHardy
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