It is common case when modem hangs with carier on but don't
receive anything from another side.
This thing commonly healed with hangup and redialing.
Enhancements below allows to determine when such action
is needed and inform attach program with SIGURG signal.
There two ioctls set: outfill and keepalive, used from both
sides of connection. Outfill repeatedly sends FRAME_END with
specified timeout (i.e. 40 seconds). It is needed to get input on
other side even if no user activity on slip line currently.
Keepalive checks FRAME_ENDs from other side, and if no one
got in specified timeout (i.e. 60 seconds, max modem retrain time),
send SIGURG to attach program.
I plan to add code to slattach to handle this thing too.
Reviewed by: wollman
operation of each clist. Limit the growth of each clist. Clists
can only grow larger than the reserved minimum if there are free
cblocks in a shared pool. The size of this pool is now fixed
(this could be improved). The reserved and maximum sizes are more
carefully allocated for slip and ppp, depending on the mtu. A maximum
MTU of 16384 is now enforced for ppp.
- Delete redundant declarations.
- Add -Wredundant-declarations to Makefile.i386 so they don't come back.
- Delete sloppy COMMON-style declarations of uninitialized data in
header files.
- Add a few prototypes.
- Clean up warnings resulting from the above.
NB: ioconf.c will still generate a redundant-declaration warning, which
is unavoidable unless somebody volunteers to make `config' smarter.
