Subject: Re: [PATCH] ipv6: reallocate addrconf router for ipv6 address when lo device up

From: Sergei Shtylyov <[email-masked]>
Date: Fri, 24 Jan 2014 01:13:56 +0400

Hello.

On 23-01-2014 10:57, Gao feng wrote:

> commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f
> "net IPv6 : Fix broken IPv6 routing table after loopback down-up"
> allocates addrconf router for ipv6 address when lo device up.
> but commit a881ae1f625c599b460cc8f8a7fcb1c438f699ad
> "ipv6:don't call addrconf_dst_alloc again when enable lo" breaks
> this behavior.

> Since the addrconf router is moved to the garbage list when
> lo device down, we should delete this router and rellocate
> a new one for ipv6 address when lo device up.

> This patch solves bug 67951 on bugzilla
> https://bugzilla.kernel.org/show_bug.cgi?id=67951

> CC: Sabrina Dubroca <[email-masked]>
> CC: Hannes Frederic Sowa <[email-masked]>
> Reported-by: Weilong Chen <[email-masked]>
> Signed-off-by: Weilong Chen <[email-masked]>
> Signed-off-by: Gao feng <[email-masked]>
> ---
>   net/ipv6/addrconf.c | 13 +++++++++++--
>   1 file changed, 11 insertions(+), 2 deletions(-)

> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index 4b6b720..6eecd9d 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -2611,8 +2611,17 @@ static void init_loopback(struct net_device *dev)
>   			if (sp_ifa->flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE))
>   				continue;
>
> -			if (sp_ifa->rt)
> -				continue;
> +			if (sp_ifa->rt) {
> +				/* This dst has been added to garbage list when
> +				 * lo device down, delete this obsolete dst and
> +				 * reallocate a new router for ifa.
> +				 */
> +				if (sp_ifa->rt->dst.obsolete > 0) {
> +					ip6_del_rt(sp_ifa->rt);
> +					sp_ifa->rt = NULL;
> +				} else
> +					continue;

    *else* arm should have {} when the other arm of *if* statement has it -- 
see Documentation/CodingStyle.

WBR, Sergei