Re: [PATCH net] net/ipv6: don't return positive numbers when nothing was dumped

[David Ahern]

On 1/22/19 2:40 PM, Jakub Kicinski wrote:
> in6_dump_addrs() returns a positive 1 if there was nothing to dump.
> This return value can not be passed as return from inet6_dump_addr()
> as is, because it will confuse rtnetlink, resulting in NLMSG_DONE
> never getting set:
> 
> $ ip addr list dev lo
> EOF on netlink
> Dump terminated
> 
> Fixes: 7c1e8a3817c5 ("netlink: fixup regression in RTM_GETADDR")
> Reported-by: Brendan Galloway <brendan.gallo...@netronome.com>
> Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
> ---
>  net/ipv6/addrconf.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index 93d5ad2b1a69..87c98f7fe997 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -5120,6 +5120,9 @@ static int inet6_dump_addr(struct sk_buff *skb, struct 
> netlink_callback *cb,
>                       if (idev) {
>                               err = in6_dump_addrs(idev, skb, cb, s_ip_idx,
>                                                    &fillargs);
> +                             if (err < 0)
> +                                     goto put_tgt_net;
> +                             err = 0;

Rather than have 2 goto's to the same target why not just:

                                if (err > 0)
                                        err = 0;
>                       }
>                       goto put_tgt_net;
>               }
> 

Thanks for the path.