Add, and use in generic netlink, helpers to dump out a netlink
policy to userspace, including all the range validation data,
nested policies etc.

This lets userspace discover what the kernel understands.

For families/commands other than generic netlink, the helpers
need to be used directly in an appropriate command, or we can
add some infrastructure (a new netlink family) that those can
register their policies with for introspection. I'm not that
familiar with non-generic netlink, so that's left out for now.

The data exposed to userspace also includes min and max length
for binary/string data, I've done that instead of letting the
userspace tools figure out whether min/max is intended based
on the type so that we can extend this later in the kernel, we
might want to just use the range data for example.

Because of this, I opted to not directly expose the NLA_*
values, even if some of them are already exposed via BPF, as
with min/max length we don't need to have different types here
for NLA_BINARY/NLA_MIN_LEN/NLA_EXACT_LEN, we just make them
all NL_ATTR_TYPE_BINARY with min/max length optionally set.

Similarly, we don't really need NLA_MSECS, and perhaps can
remove it in the future - but not if we encode it into the
userspace API now. It gets mapped to NL_ATTR_TYPE_U64 here.

Note that the exposing here corresponds to the strict policy
interpretation, and NLA_UNSPEC items are omitted entirely.
To get those, change them to NLA_MIN_LEN which behaves in
exactly the same way, but is exposed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add helpers to get the policy's signed/unsigned range
validation data.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use a validation type instead, so we can later expose
the NLA_* values to userspace for policy descriptions.

Some transformations were done with this spatch:

    @@
    identifier p;
    expression X, L, A;
    @@
    struct nla_policy p[X] = {
    [A] =
    -{ .type = NLA_EXACT_LEN_WARN, .len = L },
    +NLA_POLICY_EXACT_LEN_WARN(L),
    ...
    };
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since NLA_MSECS is really equivalent to NLA_U64, allow
it to have range validation as well.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using a pointer to a struct indicating the min/max values,
extend the ability to do range validation for arbitrary
values. Small values in the s16 range can be kept in the
policy directly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that we have limited recursive policy validation to avoid
stack overflows, change nl80211 to actually link the nested
policy (linking back to itself eventually), which allows some
code cleanups.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that we have nested policies, we can theoretically
recurse forever parsing attributes if a (sub-)policy
refers back to a higher level one. This is a situation
that has happened in nl80211, and we've avoided it there
by not linking it.

Add some code to netlink parsing to limit recursion depth.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the netlink policy, we currently have a void *validation_data
that's pointing to different things:
 * a u32 value for bitfield32,
 * the netlink policy for nested/nested array
 * the string for NLA_REJECT

Remove the pointer and place appropriate type-safe items in the
union instead.

While at it, completely dissolve the pointer for the bitfield32
case and just put the value there directly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: dsa: b53: ARL improvements

This patch series improves the b53 driver ARL search code by
renaming the ARL entries to be reflective of what they are: bins, and
then introduce the number of buckets so we can properly bound check ARL
searches.

The final patch removes an unused argument.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This argument is not used.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

ARL searches are done by reading two ARL entries at a time, do not cap
the search at 1024 which would only limit us to half of the possible ARL
capacity, but use b53_max_arl_entries() instead which does the right
multiplication between bins and indexes.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation for doing proper upper bound checking of FDB/MDB entries
being added to the ARL, provide the number of ARL buckets for each
switch chip we support. All chips have 1024 buckets, except 7278 which
has only 256.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The variable currently holds the number of ARL bins per ARL buckets,
which is different from the number of ARL entries which would be bins
times buckets. We will be adding a num_arl_buckets in a subsequent patch
so get variables straight now.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Heiner Kallweit says:

====================
r8169: refactor and improve interrupt coalescing

Refactor and improve interrupt coalescing.
====================
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Realtek provided information about a HW constraint that time limit must
not be set to 0 if the frame limit is >0. Add a check for this and
reject invalid parameter combinations.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use FIELD_PREP() to make the code better readable, and avoid the loop.
No functional change intended.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The chip supports only frame limits 0, 4, 8, .. 60 internally.
Returning EINVAL for all val % 4 != 0 seems to be a little bit too
unfriendly to the user. Therefore round up the frame limit to the next
supported value. In addition round up the time limit, else a very low
limit could be rounded down to 0, and interpreted as "ignore value"
by the chip.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The time limit provided by userspace is multiplied with 1000,
what could result in an overflow. Therefore change the time limit
parameter unit from ns to us, and avoid the problematic operation.
If there's no matching scale because provided time limit is too big,
return ERANGE instead of EINVAL to provide a hint to the user what's
wrong.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use FIELD_GET() macro to make the code better readable. In addition
change the logic to round the time limit up, not down. Reason is that
a time limit <1us would be rounded to 0 currently, what would be
interpreted as "no time limit set".
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rx and tx scale are the same always. Simplify the code by using one
scale for rx and tx only.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The net_device argument is just used to get a struct rtl8169_private
pointer via netdev_priv(). Therefore pass the struct rtl8169_private
pointer directly.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When all hsr slave interfaces are removed, hsr interface doesn't work.
At that moment, it's fine to remove an unused hsr interface automatically
for saving resources.
That's a common behavior of virtual interfaces.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: sack compression changes

Patch series refines SACK compression.

We had issues with missing SACK when TCP option space is tight.

Uses hrtimer slack to improve performance.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a sysctl to control hrtimer slack, default of 100 usec.

This gives the opportunity to reduce system overhead,
and help very short RTT flows.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, tcp_sack_new_ofo_skb() sends an ack if prior
acks were 'compressed', if room has to be made in tp->selective_acks[]

But there is no guarantee all four sack ranges can be included
in SACK option. As a matter of fact, when TCP timestamps option
is used, only three SACK ranges can be included.

Lets assume only two ranges can be included, and force the ack:

- When we touch more than 2 ranges in the reordering
  done if tcp_sack_extend() could be done.

- If we have at least 2 ranges when adding a new one.

This enforces that before a range is in third or fourth
position, at least one ACK packet included it in first/second
position.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit 86de5921 ("tcp: defer SACK compression after DupThresh")
I added a TCP_FASTRETRANS_THRESH bias to tp->compressed_ack in order
to enable sack compression only after 3 dupacks.

Since we plan to relax this rule for flows that involve
stacks not requiring this old rule, this patch adds
a distinct tp->dup_ack_counter.

This means the TCP_FASTRETRANS_THRESH value is now used
in a single location that a future patch can adjust:

	if (tp->dup_ack_counter < TCP_FASTRETRANS_THRESH) {
		tp->dup_ack_counter++;
		goto send_now;
	}

This patch also introduces tcp_sack_compress_send_ack()
helper to ease following patch comprehension.

This patch refines LINUX_MIB_TCPACKCOMPRESSED to not
count the acks that we had to send if the timer expires
or tcp_sack_compress_send_ack() is sending an ack.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2020-04-30

1) Add release all pages support, From Eran.
   to release all FW pages at once on driver unload, when supported by FW.

2) From Maxim and Tariq, Trivial Data path cleanup and code improvements
   in preparation for their next features, TLS offload and TX performance
    improvements

3) Multiple cleanups.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Prepare SPAN API for upcoming changes

Switched port analyzer (SPAN) is used for packet mirroring. Over mlxsw
this is achieved by attaching tc-mirred action to either matchall or
flower classifier.

The current API used to configure SPAN consists of two functions:
mlxsw_sp_span_mirror_add() and mlxsw_sp_span_mirror_del().

These two functions pack a lot of different operations:

* SPAN agent configuration: Determining the egress port and optional
  headers that need to encapsulate the mirrored packet (when mirroring
  to a gretap, for example)

* Egress mirror buffer configuration: Allocating / freeing a buffer when
  port is analyzed (inspected) at egress

* SPAN agent binding: Binding the SPAN agent to a trigger, if any. The
  current triggers are incoming / outgoing packet and they are only used
  for matchall-based mirroring

This non-modular design makes it difficult to extend the API for future
changes, such as new mirror targets (CPU) and new global triggers (early
dropped packets, for example).

Therefore, this patch set gradually adds APIs for above mentioned
operations and then converts the two existing users to use it instead of
the old API. No functional changes intended. Tested with existing
mirroring selftests.

Patch set overview:

Patches #1-#5 gradually add the new API
Patches #6-#8 convert existing users to use the new API
Patch #9 removes the old API
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the old SPAN API now that matchall-based and flower-based
mirroring were converted to use the new API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As previously explained, each port whose outgoing traffic is analyzed
needs to have an egress mirror buffer.

The size of the egress mirror buffer is calculated based on various
parameters, two of which are the speed and the MTU of the port.

Therefore, when the MTU or the speed of a port change, the SPAN code is
called to see if the egress mirror buffer of the port needs to be
adjusted.

Currently, this is done by traversing all the SPAN agents and for each
SPAN agent the list of bound ports is traversed.

Instead of the above, traverse the recently added list of analyzed
ports.

This will later allow us to remove the old SPAN API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In flower-based mirroring, mirroring is done with ACLs and the SPAN
agent is not bound to a port. Instead its identifier is specified in an
ACL action.

Convert this type of mirroring to use the new API.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In matchall-based mirroring, mirroring is not done with ACLs, but a SPAN
agent is bound to the ingress / egress of a port and all incoming /
outgoing traffic is mirrored.

Convert this type of mirroring to use the new API.

First the SPAN agent is resolved, then the port is marked as analyzed
and its egress mirror buffer is potentially allocated. Lastly, the
binding is performed.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, a SPAN agent can only be bound to a per-port trigger where
the trigger is either an incoming packet (INGRESS) or an outgoing packet
(EGRESS) to / from the port.

A follow-up patch set will introduce the concept of global triggers and
per-{port, TC} enablement. With global triggers, the trigger entry is
only keyed by a trigger and not by a port and a trigger. The trigger can
be, for example, a packet that was early dropped.

While the binding between the SPAN agent and the trigger is performed
only once, the trigger entry needs to be reference counted, as the
trigger can be enabled on multiple ports.

Add APIs to bind / unbind a SPAN agent to a trigger and reference count
the trigger entry in preparation for global triggers.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code that adjusts the egress buffer size is not symmetric at the
moment. The update is done via a call to
mlxsw_sp_span_port_buffer_update(), but the disablement is done inline
by invoking the write to SBIB register directly.

Wrap the disablement code in mlxsw_sp_span_port_buffer_disable().
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Suggested-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Next patch will introduce mlxsw_sp_span_port_buffer_disable() function
that disables the egress buffer on an analyzed port. Rename the opposite
function that updates the buffer on an analyzed port accordingly.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Suggested-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

An analyzed port is a port whose incoming / outgoing traffic is mirrored
to a SPAN agent and analyzed on a remote server.

A port can be analyzed by multiple tc filters and therefore the
corresponding analyzed port entry needs to be reference counted. This is
significant because ports whose outgoing traffic is analyzed need to
have an egress mirror buffer.

Add APIs to get / put an analyzed port. Allocate an egress mirror buffer
on a port when it is first inspected at egress and free the buffer when
it is no longer inspected at egress.

Protect the list of analyzed ports with a mutex, as a later patch will
traverse it from a context in which RTNL lock is not held.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Given a netdev that packets should be mirrored to, create a SPAN agent
and return its identifier to the caller.

The SPAN agent is reference counted, as multiple tc-mirred actions can
point to the same destination netdev.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mauro Carvalho Chehab says:

====================
net: manually convert files to ReST format - part 2

That's the second part of my work to convert the networking
text files into ReST. it is based on today's linux-next (next-20200430).

The full series (including those ones) are at:

	https://git.linuxtv.org/mchehab/experimental.git/log/?h=net-docs

I should be sending the remaining patches (another /38 series)
after getting those merged at -next.

The documents, converted to HTML via the building system are at:

	https://www.infradead.org/~mchehab/kernel_docs/networking/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

- add SPDX header;
- add a document title;
- adjust titles and chapters, adding proper markups;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>