[Devel] [PATCH vz7] net: Skip IP_FREEBIND for ipv6 SOCK_RAW sockets

[Kirill Tkhai]

On 21.03.2018 07:43, Andrei Vagin wrote:
> On Wed, Mar 21, 2018 at 03:07:12AM +0300, Kirill Tkhai wrote:
>> On 21.03.2018 02:18, Andrei Vagin wrote:
>>> On Tue, Mar 20, 2018 at 02:07:51PM +0300, Kirill Tkhai wrote:
>>>> IP_FREEBIND is not supported for SOCK_RAW ipv6 sockets.
>>>> See kernel rawv6_setsockopt() for the details.
>>>
>>> inet_bind() can fail for ipv6 addresses without this option:
>>>
>>> /*
>>>  * ipv6 addresses go through a “tentative” phase and
>>>  * sockets could not be bound to them in this moment
>>>  * without setting IP_FREEBIND.
>>>  */
>>>
>>> Maybe we need to add support of this option for raw socket in the kernel?
>>
>> There are already: net->ipv4.sysctl_ip_nonlocal_bind and net->ipv6.sysctl.ip_nonlocal_bind.
>> Don't they fulfill our requirements?
> 
> Yes, they do.
> 
>> We just need to use them in code in general,
>> when we port vz7 functionality to ml criu.
> 
> When are you going to do this?

I'm not going to port raw socket functionality to vz7, since this is Cyrill's patch.

I can replace IP_FREEBIND workarounds with sysctl.ip_nonlocal_bind in vanila criu instead.

Kirill

>>
>>>>
>>>> JFI:
>>>> For the rest of sockets, where they begin to support it:
>>>> the actual magic happens in do_ipv6_setsockopt(), and
>>>> IPV6_ADDRFORM optname changes sk->sk_prot to refer
>>>> to tcp_prot, udp_prot and udplite_prot, which contains
>>>> link to ip_setsockopt().
>>>>
>>>> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>>>> ---
>>>>  criu/sk-inet.c |    2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/criu/sk-inet.c b/criu/sk-inet.c
>>>> index 941de1863..4fccda48c 100644
>>>> --- a/criu/sk-inet.c
>>>> +++ b/criu/sk-inet.c
>>>> @@ -813,7 +813,7 @@ int inet_bind(int sk, struct inet_sk_info *ii)
>>>>  	 * sockets could not be bound to them in this moment
>>>>  	 * without setting IP_FREEBIND.
>>>>  	 */
>>>> -	if (ii->ie->family == AF_INET6 && ii->ie->proto != IPPROTO_RAW) {
>>>> +	if (ii->ie->family == AF_INET6 && ii->ie->type != SOCK_RAW) {
>>>>  		int yes = 1;
>>>>  
>>>>  		if (restore_opt(sk, SOL_IP, IP_FREEBIND, &yes))
>>>>
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>>