Remove nullmodem().
It may be useful to have a null modem routine, but nullmodem()
wasn't one. nullmodem() was identical to ttymodem() except it
didn't implement MDMBUF (carrier) flow control, didn't do any
wakeups for off to on carrier transitions, and didn't flush the
i/o queues for on to off carrier transitions (flushing has the side
effect of waking up readers and writers) although it did generate
SIGHUPs. The wakeups must normally be done even if nullmodem() is
null in case something is sleeping waiting for a carrier transition.
In any case, the wakeups should be harmless. They may cause bogus
results for select(), but select() is already bogus for nonstandard
line disciplines.
Kernel PPP doesn't pay attention to IPTOS_LOWDELAY, but uses
a table of port numbers, which isn't a generic method. The following
patch fixes this (the table is still used, but in addition
PPP queues the packet in fastq if IPTOS_LOWDELAY is set.
Obtained from: Tatu Ylonen <ylo@cs.hut.fi>
Submitted by: Heikki Suonsivu <hsu@clinet.fi>
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.
- Allow PPP to run multicasts natively.
- Deal properly with lots of similarly-named interfaces.
- Don't sign-extend if_flags.
NB: the last fix (to rtsock.c) must be reversed when we expand if_flags to a
reasonable size.
Submitted by: Mark Treacy
