[ Upstream commit 8ffb055beae58574d3e77b4bf9d4d15eace1ca27 ]
The recent commit 5c72299fba ("net: sched: cls_flower: Classify
packets using port ranges") had added filtering based on port ranges
to tc flower. However the commit missed necessary changes in hw-offload
code, so the feature gave rise to generating incorrect offloaded flow
keys in NIC.
One more detailed example is below:
$ tc qdisc add dev eth0 ingress
$ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \
dst_port 100-200 action drop
With the setup above, an exact match filter with dst_port == 0 will be
installed in NIC by hw-offload. IOW, the NIC will have a rule which is
equivalent to the following one.
$ tc qdisc add dev eth0 ingress
$ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \
dst_port 0 action drop
The behavior was caused by the flow dissector which extracts packet
data into the flow key in the tc flower. More specifically, regardless
of exact match or specified port ranges, fl_init_dissector() set the
FLOW_DISSECTOR_KEY_PORTS flag in struct flow_dissector to extract port
numbers from skb in skb_flow_dissect() called by fl_classify(). Note
that device drivers received the same struct flow_dissector object as
used in skb_flow_dissect(). Thus, offloaded drivers could not identify
which of these is used because the FLOW_DISSECTOR_KEY_PORTS flag was
set to struct flow_dissector in either case.
This patch adds the new FLOW_DISSECTOR_KEY_PORTS_RANGE flag and the new
tp_range field in struct fl_flow_key to recognize which filters are applied
to offloaded drivers. At this point, when filters based on port ranges
passed to drivers, drivers return the EOPNOTSUPP error because they do
not support the feature (the newly created FLOW_DISSECTOR_KEY_PORTS_RANGE
flag).
Fixes: 5c72299fba ("net: sched: cls_flower: Classify packets using port ranges")
Signed-off-by: Yoshiki Komachi <komachi.yoshiki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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