Add detail explains of -m, -o, -e and -i options, which are not documented anywhere
Signed-off-by: yupeng <yupeng0...@gmail.com> --- man/man8/ss.8 | 185 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 181 insertions(+), 4 deletions(-) diff --git a/man/man8/ss.8 b/man/man8/ss.8 index 3bec97f..8565ccb 100644 --- a/man/man8/ss.8 +++ b/man/man8/ss.8 @@ -37,19 +37,196 @@ Display both listening and non-listening (for TCP this means established connect Display only listening sockets (these are omitted by default). .TP .B \-o, \-\-options -Show timer information. +Show timer information. For tcp protocol, the output format is: +.RS +.P +timer:(<timer_name>,<expire_time>,<retrans>) +.P +.TP +.B <timer_name> +the name of the timer, there are five kind of timer names: +.RS +.P +.BR on ": means one of these timers: tcp retrans timer, tcp early retrans timer and tail loss probe timer" +.P +.BR keepalive ": tcp keep alive timer" +.P +.BR timewait ": timewait stage timer" +.P +.BR persist ": zero window probe timer" +.P +.BR unknown ": none of the above timers" +.RE +.TP +.B <expire_time> +how long time the timer will expire +.P +.TP +.B <retrans> +how many times the retran occurs +.RE .TP .B \-e, \-\-extended -Show detailed socket information +Show detailed socket information. The output format is: +.RS +.P +uid:<uid_number> ino:<inode_number> sk:<cookie> +.P +.TP +.B <uid_number> +the user id the socket belongs to +.P +.TP +.B <inode_number> +the socket's inode number in VFS +.P +.TP +.B <cookie> +an uuid of the socket +.RE .TP .B \-m, \-\-memory -Show socket memory usage. +Show socket memory usage. The output format is: +.RS +.P +skmem:(r<rmem_alloc>,rb<rcv_buf>,t<wmem_alloc>,tb<snd_buf>,f<fwd_alloc>,w<wmem_queued>,o<opt_mem>,bl<back_log>) +.P +.TP +.B <rmem_alloc> +the memory allocated for receiving packet +.P +.TP +.B <rcv_buf> +the total memory can be allocated for receiving packet +.P +.TP +.B <wmem_alloc> +the memory used for sending packet (which has been sent to layer 3) +.P +.TP +.B <snd_buf> +the total memory can be allocated for sending packet +.P +.TP +.B <fwd_alloc> +the memory allocated by the socket as cache, but not used for receiving/sending packet yet. If need memory to send/receive packet, the memory in this cache will be used before allocate additional memory. +.P +.TP +.B <wmem_queued> +The memory allocated for sending packet (which has not been sent to layer 3) +.P +.TP +.B <opt_mem> +The memory used for storing socket option, e.g., the key for TCP MD5 signature +.P +.TP +.B <back_log> +The memory used for the sk backlog queue. On a process context, if the process is receiving packet, and a new packet is received, it will be put into the sk backlog queue, so it can be received by the process immediately +.RE .TP .B \-p, \-\-processes Show process using socket. .TP .B \-i, \-\-info -Show internal TCP information. +Show internal TCP information. Below fields may appear: +.RS +.P +.TP +.B ts +show string "ts" if the timestamp option is set +.P +.TP +.B sack +show string "sack" if the sack option is set +.P +.TP +.B ecn +show string "ecn" if the explicit congestion notification option is set +.P +.TP +.B ecnseen +show string "ecnseen" if the saw ecn flag is found in received packets +.P +.TP +.B fastopen +show string "fastopen" if the fastopen option is set +.P +.TP +.B cong_alg +the congestion algorithm name, the default congestion algorithm is "cubic" +.P +.TP +.B wscale:<snd_wscale>:<rcv_wscale> +if window scale option is used, this field shows the send scale factory and receive scale factory +.P +.TP +.B rto:<icsk_rto> +tcp re-transmission timeout value, the unit is millisecond +.P +.TP +.B backoff:<icsk_backoff> +used for exponential backoff re-transmission, the actual re-transmission timeout value is icsk_rto << icsk_backoff +.P +.TP +.B rtt:<rtt>/<rttvar> +rtt is the average round trip time, rttvar is the mean deviation of rtt, their units are millisecond +.P +.TP +.B ato:<ato> +ack timeout, unit is millisecond, used for delay ack mode +.P +.TP +.B mss:<mss> +max segment size +.P +.TP +.B cwnd:<cwnd> +congestion window size +.P +.TP +.B ssthresh:<ssthresh> +tcp congestion window slow start threshold +.P +.TP +.B bytes_acked:<bytes_acked> +bytes acked +.P +.TP +.B bytes_received:<bytes_received> +bytes received +.P +.TP +.B segs_out:<segs_out> +segments sent out +.P +.TP +.B segs_in:<segs_in> +segments received +.P +.TP +.B send <send_bps>bps +egress bps +.P +.TP +.B lastsnd:<lastsnd> +how long time since the last packet sent, the unit is millisecond +.P +.TP +.B lastrcv:<lastrcv> +how long time since the last packet received, the unit is millisecond +.P +.TP +.B lastack:<lastack> +how long time since the last ack received, the unit is millisecond +.P +.TP +.B pacing_rate <pacing_rate>bps/<max_pacing_rate>bps +the pacing rate and max pacing rate +.P +.TP +.B rcv_space:<rcv_space> +a helper variable for TCP internal auto tuning socket receive buffer +.RE .TP .B \-K, \-\-kill Attempts to forcibly close sockets. This option displays sockets that are -- 2.7.4
