Default use_mq to off

In some hardware configurations, unconditionally using cake_mq is
problematic. In particular, some SoCs have 16 TX queues but only two
CPUs, and 16 cake instances can end up taking up quite a bit of memory.

To be cautious, default use_mq to off for now. Users can still opt in if
they want to try out cake_mq on their hardware.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

sqm: gate USE_MQ after loading the selected qdisc script

start-sqm sources defaults.sh before the selected *.qos script, so SUPPORT_MQ is not yet set at that point. This can force USE_MQ=0 even for scripts that declare SUPPORT_MQ=1 (e.g. piece_of_cake.qos).

Move the SUPPORT_MQ gate to start-sqm after loading the selected script, and keep per-interface cake_mq selection in select_cake().

Signed-off-by: Andrea Pesaresi <andreapesaresi82@gmail.com>

Support cake_mq in the CAKE-based QoS scripts

Support automatically selecting cake_mq in the layer_cake and
piece_of_cake QoS scripts. On egress, cake_mq will be used if the device
has multiple queues. On ingress, set MQ_IFB to ensure that the IFB
devices are created as multi-queue, which will also allow us to use
cake_mq there.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

Update simplest_tbf.qos.help

Signed-off-by: diogosena <diogosena@gmail.com>

runners: Expose a 'cleanup' action for silent cleanup of an interface

If a network interface is removed before SQM is stopped on that interface,
removing the qdisc from that interface will result in errors in the log.
Whereas not running the 'stop' action will result in leftover state
files (and possibly an IFB interface).

While the right thing to do would be to stop SQM before removing the
interface, this is not always possible; for instance, pppd doesn't have a
'pre-down' hook. So to accommodate this use case, add a new 'cleanup'
action, which just unwinds the firewall rules, removes the IFB
interface (but silently in case it does not exist), and deletes the state
file.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

Merge pull request #147 from tohojo/iptables-compat

Iptables compat fixes

defaults.sh: Don't override INSMOD variable if it is already set

@SpareSimian noticed that sqm-scripts would always use 'insmod' to load
modules on CentOS even though modprobe was also available. @gordonmessmer
noticed that this was due to the way the shell chains '&&' and '||'
operators, which would evaluate the second assignment if the first
zero-length check fails. And since defaults.sh is included from both
'start-sqm' and the .qos scripts, this double-evaluation always happens on
non-OpenWrt installations.

Fix this by properly grouping the assignment operators so they are
evaluated together if the variable is unset.

Fixes #133.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

Sqm-Scripts 1.5.0

Sqm-Scripts 1.4.0

Explain why we are reseting the SILENT variable

Also make ERRLOG a local var, and collaps the two identical tests into a
single if block.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>