Re: [PATCH] selftests: mptcp: add comment for getaddrinfo

[Paolo Abeni]

On 4/8/25 5:09 AM, zhenwei pi wrote:
> On 4/8/25 09:43, Geliang Tang wrote:
>> On Mon, 2025-04-07 at 16:51 +0800, zhenwei pi wrote:
>>> mptcp_connect.c is a startup tutorial of MPTCP programming, however
>>> there is a lack of ai_protocol(IPPROTO_MPTCP) usage. Add comment for
>>> getaddrinfo MPTCP support.
>>>
>>> Signed-off-by: zhenwei pi <zhenwei.pi@xxxxxxxxx>
>>> Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
>>> ---
>>>   tools/testing/selftests/net/mptcp/mptcp_connect.c | 12 ++++++++++++
>>>   1 file changed, 12 insertions(+)
>>>
>>> diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c
>>> b/tools/testing/selftests/net/mptcp/mptcp_connect.c
>>> index c83a8b47bbdf..6b9031273964 100644
>>> --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
>>> +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
>>> @@ -179,6 +179,18 @@ static void xgetnameinfo(const struct sockaddr
>>> *addr, socklen_t addrlen,
>>>   	}
>>>   }
>>>   
>>> +/* There is a lack of MPTCP support from glibc, these code leads
>>> error:
>>> + *	struct addrinfo hints = {
>>> + *		.ai_protocol = IPPROTO_MPTCP,
>>> + *		...
>>> + *	};
>>> + *	err = getaddrinfo(node, service, &hints, res);
>>> + *	...
>>> + * So using IPPROTO_TCP to resolve, and use TCP/MPTCP to create
>>> socket.
>>> + *
>>> + * glibc starts to support MPTCP since v2.42.
>>> + * Link:
>>> https://sourceware.org/git/?p=glibc.git;a=commit;h=a8e9022e0f82
>>
>> Thanks for adding getaddrinfo mptcp support to glibc. I think we should
>> not only add a comment for getaddrinfo mptcp here, but also add an
>> example of using it in mptcp_connect.c. I will work with you to
>> implement this example in v2.

While at that, please also clean-up the tag area: only a single SoB is
required. If you submit using a different mail address WRT the SoB tag,
you should add a 'From: ' header. See
Documentation/process/submitting-patches.rst for the details.

Thanks,

Paolo