Date: Wed, 21 Dec 2005 13:25:27 -0800
From: Stephen Hemminger <shemminger@osdl.org>
To: mikukkon@iki.fi
Cc: bridge@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] BRIDGE: Fix faulty check in
 br_stp_recalculate_bridge_id()
Message-ID: <20051221132527.1ef12bcf@dxpl.pdx.osdl.net>
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On Wed, 21 Dec 2005 21:55:27 +0200
mikukkon@iki.fi wrote:

> I did a compile with extra gcc warnings, and found a bug in
> net/bridge/br_stp_if.c function br_stp_recalculate_bridge_id():
> compare_ether_addr() returns 0 if match, positive if not, so
> checking it for negative is wrong. 
> 
> Signed-of-by: Mika Kukkonen <mikukkon@iki.fi>
> 
> ---
> 
>  net/bridge/br_stp_if.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
> index ac09b6a..08c52c2 100644
> --- a/net/bridge/br_stp_if.c
> +++ b/net/bridge/br_stp_if.c
> @@ -158,7 +158,7 @@ void br_stp_recalculate_bridge_id(struct
>  
>  	list_for_each_entry(p, &br->port_list, list) {
>  		if (addr == br_mac_zero ||
> -		    compare_ether_addr(p->dev->dev_addr, addr) < 0)
> +		    compare_ether_addr(p->dev->dev_addr, addr))
>  			addr = p->dev->dev_addr;
>  
>  	}

Actually that compare_ether_addr needs to be replaced by memcmp again.
Because for bridge id calc it wants the min() of all the device addresses.

-- 
Stephen Hemminger <shemminger@osdl.org>
OSDL http://developer.osdl.org/~shemminger
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