Add ability to add the netfilter connmark support.
Typical usage:
...lets tag outgoing icmp with mark 0x10..
iptables -tmangle -A PREROUTING -p icmp -j CONNMARK --set-mark 0x10
..add on ingress of $ETH an extractor for connmark...
tc filter add dev $ETH parent ffff: prio 4 protocol ip \
u32 match ip protocol 1 0xff \
flowid 1:1 \
action connmark continue
...if the connmark was 0x11, we police to a ridic rate of 10Kbps
tc filter add dev $ETH parent ffff: prio 5 protocol ip \
handle 0x11 fw flowid 1:1 \
action police rate 10kbit burst 10k
Other ways to use the connmark is to supply the zone, index and
branching choice. Refer to help.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Kernel code and interface.
--------------------------
* Compile time switches
There is only one, but very important, compile time switch.
It is not settable by "make config", but should be selected
manually and after a bit of thinking in <include/net/pkt_sched.h>
PSCHED_CLOCK_SOURCE can take three values:
PSCHED_GETTIMEOFDAY
PSCHED_JIFFIES
PSCHED_CPU
PSCHED_GETTIMEOFDAY
Default setting is the most conservative PSCHED_GETTIMEOFDAY.
It is very slow both because of weird slowness of do_gettimeofday()
and because it forces code to use unnatural "timeval" format,
where microseconds and seconds fields are separate.
Besides that, it will misbehave, when delays exceed 2 seconds
(f.e. very slow links or classes bounded to small slice of bandwidth)
To resume: as only you will get it working, select correct clock
source and forget about PSCHED_GETTIMEOFDAY forever.
PSCHED_JIFFIES
Clock is derived from jiffies. On architectures with HZ=100
granularity of this clock is not enough to make reasonable
bindings to real time. However, taking into account Linux
architecture problems, which force us to use artificial
integrated clock in any case, this switch is not so bad
for schduling even on high speed networks, though policing
is not reliable.
PSCHED_CPU
It is available only for alpha and pentiums with correct
CPU timestamp. It is the fastest way, use it when it is available,
but remember: not all pentiums have this facility, and
a lot of them have clock, broken by APM etc. etc.