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

[zhenwei pi]

On 4/8/25 09:43, Geliang Tang wrote:
> Hi zhenwei,
>
> 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.
>
> Thanks,
> -Geliang

Good idea, thank you Geliang!

> > + */
> >   static void xgetaddrinfo(const char *node, const char *service,
> >   			 const struct addrinfo *hints,
> >   			 struct addrinfo **res)