Re: [PATCH mptcp-next 4/4] selftests: mptcp: pm: get server-side flag

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 11/09/2025 10:16, Geliang Tang wrote:
> Hi Matt,
> 
> On Tue, 2025-09-09 at 18:30 +0200, Matthieu Baerts (NGI0) wrote:
>> server-side info linked to the MPTCP connect/established events can
>> now
>> come from the flags, in addition to the dedicated attribute.
>>
>> The attribute is now deprecated -- in favour of the new flag, and
>> will
>> be removed later on.
>>
>> Print this info only once.
>>
>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>> ---
>>  tools/testing/selftests/net/mptcp/pm_nl_ctl.c | 9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
>> b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
>> index
>> 93fea3442216c8fef43731a99c1d5710f234b150..d4981b76693bbddca74169437a5
>> 40ad6294cf1d5 100644
>> --- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
>> +++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
>> @@ -2,6 +2,7 @@
>>  
>>  #include <errno.h>
>>  #include <error.h>
>> +#include <stdbool.h>
>>  #include <stdio.h>
>>  #include <stdlib.h>
>>  #include <string.h>
>> @@ -113,6 +114,8 @@ static int capture_events(int fd, int
>> event_group)
>>  		error(1, errno, "could not join the "
>> MPTCP_PM_EV_GRP_NAME " mcast group");
>>  
>>  	do {
>> +		bool server_side = false;
>> +
>>  		FD_ZERO(&rfds);
>>  		FD_SET(fd, &rfds);
>>  		res_len = NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
>> @@ -187,18 +190,22 @@ static int capture_events(int fd, int
>> event_group)
>>  				else if (attrs->rta_type ==
>> MPTCP_ATTR_ERROR)
>>  					fprintf(stderr, ",error:%u",
>> *(__u8 *)RTA_DATA(attrs));
>>  				else if (attrs->rta_type ==
>> MPTCP_ATTR_SERVER_SIDE)
>> -					fprintf(stderr,
>> ",server_side:%u", *(__u8 *)RTA_DATA(attrs));
> 
> It is a little strange that server_side is displayed at the end. It
> changes the original display order.  It is better to display it in the
> original position, but check whether the server_side flag is false:

I'm not sure to understand why it is strange: the output is read by
scripts, the order should not matter, right?

Plus the order depends on what was received by the kernel, not where
they are printed here.

Do you really think it is worth it changing this patch and making longer
just to keep an order that we don't currently fully control here?

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.