Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <ba4d41bc-ec24-f4b4-e4d5-f9db51fed071@kernel.org>
Date:   Thu, 24 Nov 2022 20:00:24 -0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.13.1
Subject: Re: [PATCH] net: setsockopt: fix IPV6_UNICAST_IF option for connected
 sockets
Content-Language: en-US
To:     Richard Gobert <richardbgobert@gmail.com>, davem@davemloft.net,
        yoshfuji@linux-ipv6.org, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20221124114713.GA73129@debian>
From:   David Ahern <dsahern@kernel.org>
In-Reply-To: <20221124114713.GA73129@debian>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 11/24/22 4:48 AM, Richard Gobert wrote:
> Change the behaviour of ip6_datagram_connect to consider the interface
> set by the IPV6_UNICAST_IF socket option, similarly to udpv6_sendmsg.
> 
> This change is the IPv6 counterpart of the fix for IP_UNICAST_IF.
> The tests introduced by that patch showed that the incorrect
> behavior is present in IPv6 as well.
> This patch fixes the broken test.
> 
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Link: https://lore.kernel.org/r/202210062117.c7eef1a3-oliver.sang@intel.com
> 

Fixes tag here.

> Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
> ---
>  net/ipv6/datagram.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
> index 7c7155b48f17..c3999f9e3545 100644
> --- a/net/ipv6/datagram.c
> +++ b/net/ipv6/datagram.c
> @@ -42,24 +42,30 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
>  {
>  	struct inet_sock *inet = inet_sk(sk);
>  	struct ipv6_pinfo *np = inet6_sk(sk);
> +	int oif;

	int oif = sk->sk_bound_dev_if;
>  
>  	memset(fl6, 0, sizeof(*fl6));
>  	fl6->flowi6_proto = sk->sk_protocol;
>  	fl6->daddr = sk->sk_v6_daddr;
>  	fl6->saddr = np->saddr;
> -	fl6->flowi6_oif = sk->sk_bound_dev_if;
> +	oif = sk->sk_bound_dev_if;

and then drop this line in the middle of all of the fl6 setup.

>  	fl6->flowi6_mark = sk->sk_mark;
>  	fl6->fl6_dport = inet->inet_dport;
>  	fl6->fl6_sport = inet->inet_sport;
>  	fl6->flowlabel = np->flow_label;
>  	fl6->flowi6_uid = sk->sk_uid;
>  
> -	if (!fl6->flowi6_oif)
> -		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
> +	if (!oif)
> +		oif = np->sticky_pktinfo.ipi6_ifindex;
>  
> -	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
> -		fl6->flowi6_oif = np->mcast_oif;
> +	if (!oif) {
> +		if (ipv6_addr_is_multicast(&fl6->daddr))
> +			oif = np->mcast_oif;
> +		else
> +			oif = np->ucast_oif;
> +	}
>  
> +	fl6->flowi6_oif = oif;
>  	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
>  }
>  

thanks for the fix.

Besides the nit,
Reviewed-by: David Ahern <dsahern@kernel.org>