Add netbw option to systat

[John Baldwin]

On Wednesday, July 02, 2014 8:54:41 pm hiren panchasara wrote:
> On Wed, Jul 2, 2014 at 4:50 PM, Bryan Venteicher
> <bryanv at daemoninthecloset.org> wrote:
> > Awhile back, DragonlyFlyBSD added a netbw option to systat that I've 
ported
> > to FreeBSD and found handy at various times:
> >
> >    netbw      Display aggregate and per-connection TCP receive and 
transmit
> >                       rates.  Only active TCP connections are shown.
> >
> > Leading to output such as:
> >
> > tcp accepts        connects                 rcv 1.192G snd 15.77K rexmit
> >
> >   192.168.10.80:22      192.168.10.20:23103 rcv        snd 415.7  [  NTSX 
]
> >   192.168.10.80:22      192.168.10.20:46560 rcv 19.80M snd 14.47K [  NTSX 
]
> >   192.168.10.80:22      192.168.10.20:60699 rcv        snd 886.3  [  NTSX 
]
> >   192.168.10.81:5201    192.168.10.51:60844 rcv 293.2M snd        [R  TSX 
]
> >   192.168.10.81:5201    192.168.10.51:60845 rcv 293.5M snd        [R  TSX 
]
> >   192.168.10.81:5201    192.168.10.51:60846 rcv 293.2M snd        [R  TSX 
]
> >   192.168.10.81:5201    192.168.10.51:60847 rcv 292.9M snd        [R  TSX 
]
> >
> > It uses the sequences number from the 'struct tcpcb' to derive the rates,
> > which is usually good but certainly not perfect (i.e., don't set the
> > interval too long).
> >
> > I'd like to commit this if anybody else thinks they'd find it useful.
> >
> > http://people.freebsd.org/~bryanv/patches/systat-netbw.patch
> 
> I like the idea.

I also like the idea.

> A few things about the patch:
> 1) You may want to remove the code hidden behind "#if 0" at 2 places.
> 2) I am not entirely clear on why/if we need the last column with
> flags but if we keep it (for compatibility of any other reason), It
> would be nice to have those flags explained in the manpage:
> 
> + mvwprintw(wnd, LINES-2, 0,
> +  "Rate/sec, "
> +  "R=rxpend T=txpend N=nodelay T=tstmp "
> +  "S=sack X=winscale F=fastrec");
> 3) I feel that the header line for o/p (specially 'tcp accepts and
> connects' terminology) can be improved but I do not have a better
> suggestion :-)

4) Should numtok() just be humanize_number?  Or rather, would it simplify
   the code to use humanize_number?  (It might not, but if it does, I
   think that would be preferable.)

-- 
John Baldwin