[ECOS] changing tcp_maxidle?

[Grant Edwards]

Leaving aside the debate on whether TCP keepalive is
intrinsically evil or not, I find that not only do I need to
enable it, I need to control the timing parameters at runtime.

These parameters are controlled by five global variables in
tcp_timer.c:

  int     tcp_keepidle = TCPTV_KEEP_IDLE;
  int     tcp_keepintvl = TCPTV_KEEPINTVL;
  int     tcp_maxpersistidle = TCPTV_KEEP_IDLE;   /* max idle time in persist */
  int     tcp_maxidle;

The first four are no problem.  Since they are globally
visible, and statically initialized, my appication can modify
them as needed.  However, the fifth one (tcp_maxidle) is not
initialized statically.  Rather, it is initialized every 500ms
inside tcp_slowtimo():

  void
  tcp_slowtimo()
  {
  [...]
     s = splsoftnet();
     tcp_maxidle = TCPTV_KEEPCNT * tcp_keepintvl;

I can find no other place where tcp_maxidle is set, and it
doesn't appear that its value ever changes.  Is there any
reason not to initialize tcp_maxidle statically?  Something
like:

  int     tcp_keepidle = TCPTV_KEEP_IDLE;
  int     tcp_keepintvl = TCPTV_KEEPINTVL;
  int     tcp_maxpersistidle = TCPTV_KEEP_IDLE;   /* max idle time in persist */
  int     tcp_maxidle = TCPTV_KEEPCNT * TCPTV_KEEPINTVL;;

That would allow me a much cleaner way to dig a hole into which
I may later fall...

-- 
Grant Edwards
grante@visi.com