[PATCH v2 iproute2 1/1] ss: add missing path MTU parameter

[PATCH v2 iproute2 1/1] ss: add missing path MTU parameter

[Roman Mashak]

v2:
   Print the path MTU immediately after the MSS, as it is easier to parse
   for humans (suggested by Neal Cardwell).

Signed-off-by: Roman Mashak <mrv@mojatatu.com>
---
 man/man8/ss.8 | 4 ++++
 misc/ss.c     | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/man/man8/ss.8 b/man/man8/ss.8
index 6d06383..0d52673 100644
--- a/man/man8/ss.8
+++ b/man/man8/ss.8
@@ -184,6 +184,10 @@ max segment size
 congestion window size
 .P
 .TP
+.B pmtu:<pmtu>
+path MTU value
+.P
+.TP
 .B ssthresh:<ssthresh>
 tcp congestion window slow start threshold
 .P
diff --git a/misc/ss.c b/misc/ss.c
index da52d5e..b43bd0b 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -727,6 +727,7 @@ struct tcpstat {
 	int		    mss;
 	int		    rcv_mss;
 	int		    advmss;
+	unsigned int	    pmtu;
 	unsigned int	    cwnd;
 	unsigned int	    lastsnd;
 	unsigned int	    lastrcv;
@@ -1959,6 +1960,8 @@ static void tcp_stats_print(struct tcpstat *s)
 
 	if (s->mss)
 		printf(" mss:%d", s->mss);
+	if (s->pmtu)
+		printf(" pmtu:%u", s->pmtu);
 	if (s->rcv_mss)
 		printf(" rcvmss:%d", s->rcv_mss);
 	if (s->advmss)
@@ -2308,6 +2311,7 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r,
 		s.reordering	 = info->tcpi_reordering;
 		s.rcv_ssthresh   = info->tcpi_rcv_ssthresh;
 		s.cwnd		 = info->tcpi_snd_cwnd;
+		s.pmtu		 = info->tcpi_pmtu;
 
 		if (info->tcpi_snd_ssthresh < 0xFFFF)
 			s.ssthresh = info->tcpi_snd_ssthresh;
-- 
2.7.4

Re: [PATCH v2 iproute2 1/1] ss: add missing path MTU parameter

[Stephen Hemminger]

On Thu, 14 Dec 2017 14:59:11 -0500
Roman Mashak <mrv@mojatatu.com> wrote:

> v2:
>    Print the path MTU immediately after the MSS, as it is easier to parse
>    for humans (suggested by Neal Cardwell).
> 
> Signed-off-by: Roman Mashak <mrv@mojatatu.com>

Thanks for the patch, it looks like a good field to show.

Unfortunately, it does not apply cleanly to current iproute2 master.
Please rebase and resubmit.

Re: [PATCH v2 iproute2 1/1] ss: add missing path MTU parameter

[Stefano Brivio]

Hi Roman,

On Thu, 14 Dec 2017 14:59:11 -0500
Roman Mashak <mrv@mojatatu.com> wrote:

> @@ -1959,6 +1960,8 @@ static void tcp_stats_print(struct tcpstat *s)
>  
>  	if (s->mss)
>  		printf(" mss:%d", s->mss);
> +	if (s->pmtu)
> +		printf(" pmtu:%u", s->pmtu);

You'll simply need to change this to out() now, as this print will be
buffered.

-- 
Stefano

Re: [PATCH v2 iproute2 1/1] ss: add missing path MTU parameter

[Roman Mashak]

Stefano Brivio <sbrivio@redhat.com> writes:

> On Thu, 14 Dec 2017 14:59:11 -0500
> Roman Mashak <mrv@mojatatu.com> wrote:
>
>> @@ -1959,6 +1960,8 @@ static void tcp_stats_print(struct tcpstat *s)
>>  
>>  	if (s->mss)
>>  		printf(" mss:%d", s->mss);
>> +	if (s->pmtu)
>> +		printf(" pmtu:%u", s->pmtu);
>
> You'll simply need to change this to out() now, as this print will be
> buffered.

Oh I see why it does not apply, I'll resubmit. Thanks Stefano.