Re: [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

On Samstag, 28. Januar 2017 10:25:25 CET Sven Eckelmann wrote:

The net_xmit_eval has side effects because it is not making sure that e isn't evaluated twice.

#define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))

The code proposed by David Miller

return net_xmit_eval(dev_queue_xmit(skb));

will therefore get transformed into

return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))

dev_queue_xmit will therefore be tried again (with an already consumed skb) whenever the return code is not NET_XMIT_CN.

Fixes: 17efab9867c5 ("batman-adv: Simplify handling of NET_XMIT_CN") Signed-off-by: Sven Eckelmann sven@narfation.org

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net/batman-adv/send.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

I was so embarrassed about not catching these two that I've already applied them an prepared the changes for net-next.

Kind regards, Sven