Description of problem:
tcp->snd_cwd is a u32, but ss treats it like a signed int.  This results in negative bandwidth calculations.


src/include/linux/tcp.h

202:            is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
232:    u32     snd_cwnd;       /* Sending congestion window            */ 
233:    u32     snd_cwnd_cnt;   /* Linear increase counter              */
234:    u32     snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
235:    u32     snd_cwnd_used;
236:    u32     snd_cwnd_stamp;

>>> Probably need to change this %d to a %u, and deal with the casting to double below. <<<<


iproute2-3.10.0/misc/ss.c

1270         if (s.cwnd != 2)
1271             printf(" cwnd:%d", s.cwnd);

1416         if (info->tcpi_snd_cwnd != 2)
1417             printf(" cwnd:%d", info->tcpi_snd_cwnd);

1431         if (rtt > 0 && info->tcpi_snd_mss && info->tcpi_snd_cwnd) {
1432             printf(" send %sbps",
1433                    sprint_bw(b1, (double) info->tcpi_snd_cwnd *
1434                      (double) info->tcpi_snd_mss * 8000000.
1435                      / rtt));



Sample data (DCTCP):

[root@tesla02 ~]# /usr/lpp/mmfs/bin/mmdsh -F host.list 'ss -e -t -o -i | grep -A 1 gpfs | grep -A 1 10.219.31.131 | grep alpha' | grep -v tesla02 | sort | column -t
tesla11:  ts  sack  ecn  ecnseen  dctcp  wscale:1,1  rto:11  rtt:0.144/0.047  ato:40  mss:1448  cwnd:1187830594  dctcp:(ce_state:0,alpha:15,ab_ecn:0,ab_tot:0)      send  95554372228.4Mbps   lastrcv:2    unacked:10          retrans:0/21231546  reordering:40       rcv_rtt:11.375    rcv_space:262236
tesla12:  ts  sack  ecn  ecnseen  dctcp  wscale:1,1  rto:11  rtt:0.109/0.028  ato:40  mss:1448  cwnd:-679123792  dctcp:(ce_state:0,alpha:15,ab_ecn:0,ab_tot:0)      send  384274597709.5Mbps  lastrcv:1    unacked:13          retrans:0/11495136  sacked:2            reordering:38     rcv_rtt:12.375    rcv_space:262236
tesla13:  ts  sack  ecn  ecnseen  dctcp  wscale:1,1  rto:11  rtt:0.095/0.035  ato:40  mss:1448  cwnd:28          dctcp:



Version-Release number of selected component (if applicable):
iproute-3.10.0-54.el7_2.1

How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info: