Re: [PATCH v01] net/af_packet: don't specify protocol on socket create

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 10/26/2024 12:10 AM, Ferruh Yigit wrote:
> On 10/17/2024 2:38 AM, Stephen Hemminger wrote:
>> On Sun, 13 Oct 2024 16:59:47 +0300
>> Gur Stavi <gur.stavi@huawei.com> wrote:
>>
>>> When creating AF_PACKET socket with specified protocol it is
>>> immediately implicitly bound to any existing interface and
>>> becomes RUNNING. Calling bind on such socket is affectively unbind
>>> from "any interface", then bind to the specific interface.
>>>
>>> When creating socket with 0 as protocol, it is created in non-RUNNING
>>> state, then it can be bound to interface and protocol in a single bind
>>> call and switch to RUNNING state.
>>>
>>> Especially with ETH_P_ALL, binding to any interface is not a good idea.
>>> It is safer and faster to use the 2nd approach.
>>>
>>> This patch replaces protocol in socket creation from ETH_P_ALL to 0.
>>>
>>> Signed-off-by: Gur Stavi <gur.stavi@huawei.com>
>>
>> This makes sense see packet(7) man page:
>>
>>        By default, all packets of the specified protocol type are passed  to  a
>>        packet  socket.   To  get  packets  only  from  a specific interface use
>>        bind(2) specifying an address in a struct sockaddr_ll to bind the packet
>>        socket to an interface.  Fields used for binding are sll_family  (should
>>        be AF_PACKET), sll_protocol, and sll_ifindex.
>>
>> So there is a small window where the packet socket could pick up junk before
>> the bind from other interfaces.
>>
> 
> Thanks, this answers some of my questions in this thread, also I did
> some experiment and verified the same.
> 
> I agree this change is more close the intention of the driver (driver is
> not to get packets from all interfaces), hence:
> 
> Acked-by: Ferruh Yigit <ferruh.yigit@amd.com>
> 

Series applied to dpdk-next-net/main, thanks.