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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Hangbin Liu <liuhangbin@gmail.com>, netdev@vger.kernel.org
Cc: Stefano Brivio <sbrivio@redhat.com>,
	"David S . Miller" <davem@davemloft.net>,
	David Ahern <dsa@cumulusnetworks.com>
Subject: Re: [PATCH net] sit: use ipv6_mod_enabled to check if ipv6 is disabled
Date: Sun, 24 Feb 2019 20:24:51 -0800	[thread overview]
Message-ID: <7c0f5c9c-d918-de27-643d-416509576be4@gmail.com> (raw)
In-Reply-To: <20190225041243.9753-1-liuhangbin@gmail.com>



On 02/24/2019 08:12 PM, Hangbin Liu wrote:
> ipv6_mod_enabled() is more safe and gentle to check if ipv6 is disabled
> at running time.
> 


Why is it better exactly ?

IPv6 can be enabled on the host, but disabled per device

/proc/sys/net/ipv6/conf/{name}/disable_ipv6


> Fixes: 173656accaf5 ("sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()")
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  net/ipv6/sit.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
> index e8a1dabef803..eea1f19985a7 100644
> --- a/net/ipv6/sit.c
> +++ b/net/ipv6/sit.c
> @@ -546,7 +546,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
>  	}
>  
>  	err = 0;
> -	if (__in6_dev_get(skb->dev) &&
> +	if (ipv6_mod_enabled() &&
>  	    !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
>  		goto out;
>  
> 

  reply	other threads:[~2019-02-25  4:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-25  4:12 [PATCH net] sit: use ipv6_mod_enabled to check if ipv6 is disabled Hangbin Liu
2019-02-25  4:24 ` Eric Dumazet [this message]
2019-02-25  8:17   ` Hangbin Liu
2019-02-25 16:39     ` Eric Dumazet
2019-02-25 16:57       ` David Ahern
2019-02-26  1:55         ` Hangbin Liu
2019-02-26  2:15           ` David Ahern
2019-02-26  4:08             ` Hangbin Liu
2019-02-26  4:36               ` Eric Dumazet
2019-02-26  1:43       ` Hangbin Liu

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