Correct two errors which cancel each other out:
* Do not send twice the length of the actual provided by the user to the kernel
* Do not dump half the length of the cookie provided by the kernel
As the cookie is now stored in the kernel at its correct length rather
than double the that length cookies of up to the maximum size of 16 bytes
may now be stored rather than a maximum of half that length.
Output of dump is the same before and after this change,
but the data stored in the kernel is now exactly the cookie
rather than the cookie + as many trailing zeros.
Before:
# tc filter add dev eth0 protocol ip parent ffff: \
flower ip_proto udp action drop \
cookie 0123456789abcdef0123456789abcdef
RTNETLINK answers: Invalid argument
After:
# tc filter add dev eth0 protocol ip parent ffff: \
flower ip_proto udp action drop \
cookie 0123456789abcdef0123456789abcdef
# tc filter show dev eth0 ingress
eth_type ipv4
ip_proto udp
not_in_hw
action order 1: gact action drop
random type none pass val 0
index 1 ref 1 bind 1 installed 1 sec used 1 sec
Action statistics:
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
cookie len 16 0123456789abcdef0123456789abcdef
Fixes: fd8b3d2c1b ("actions: Add support for user cookies")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Simon Horman <simon.horman@netronome.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.
b75e0f6f4b