ethtool: netlink: always pass genl_info to .prepare_data

We had a number of bugs in the past because developers forgot
to fully test dumps, which pass NULL as info to .prepare_data.
.prepare_data implementations would try to access info->extack
leading to a null-deref.

Now that dumps and notifications can access struct genl_info
we can pass it in, and remove the info null checks.

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # pause
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ethtool: netlink: convert commands to common SET

Convert all SET commands where new common code is applicable.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: use ethnl_parse_header_dev_put()

It seems I missed that most ethnl_parse_header_dev_get() callers
declare an on-stack struct ethnl_req_info, and that they simply call
dev_put(req_info.dev) when about to return.

Add ethnl_parse_header_dev_put() helper to properly untrack
reference taken by ethnl_parse_header_dev_get().

Fixes: e4b8954074f6 ("netlink: add net device refcount tracker to struct ethnl_req_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: link up ethnl_header_policy as a nested policy

To get the most out of parsing by the core, and to allow dumping
full policies we need to specify which policy applies to nested
attrs. For headers it's ethnl_header_policy.

$ sed -i 's@\(ETHTOOL_A_.*HEADER\].*=\) { .type = NLA_NESTED },@\1\n\t\tNLA_POLICY_NESTED(ethnl_header_policy),@' net/ethtool/*

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: trim policy tables

Since ethtool uses strict attribute validation there's no need
to initialize all attributes in policy tables. 0 is NLA_UNSPEC
which is going to be rejected. Remove the NLA_REJECTs.

Similarly attributes above maxattrs are rejected, so there's
no need to always size the policy tables to ETHTOOL_A_..._MAX.

v2: - new patch

Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: wire up set policies to ops

Similarly to get commands wire up the policies of set commands
to get parsing by the core and policy dumps.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: wire up get policies to ops

Wire up policies for get commands in struct nla_policy of the ethtool
family. Make use of genetlink code attr validation and parsing, as well
as allow dumping policies to user space.

For every ETHTOOL_MSG_*_GET:
- add 'ethnl_' prefix to policy name
- add extern declaration in net/ethtool/netlink.h
- wire up the policy & attr in ethtool_genl_ops[].
- remove .request_policy and .max_attr from ethnl_request_ops.

Obviously core only records the first "layer" of parsed attrs
so we still need to parse the sub-attrs of the nested header
attribute.

v2:
- merge of patches 1 and 2 from v1
- remove stray empty lines in ops
- also remove .max_attr

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: fix reference leak in some *_SET handlers

Andrew noticed that some handlers for *_SET commands leak a netdev
reference if required ethtool_ops callbacks do not exist. A simple
reproducer would be e.g.

ip link add veth1 type veth peer name veth2
ethtool -s veth1 wol g
ip link del veth1

Make sure dev_put() is called when ethtool_ops check fails.

v2: add Fixes tags

Fixes: a53f3d41e4d3 ("ethtool: set link settings with LINKINFO_SET request")
Fixes: bfbcfe2032e7 ("ethtool: set link modes related data with LINKMODES_SET request")
Fixes: e54d04e3afea ("ethtool: set message mask with DEBUG_SET request")
Fixes: 8d425b19b305 ("ethtool: set wake-on-lan settings with WOL_SET request")
Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: rename ethnl_parse_header() to ethnl_parse_header_dev_get()

Andrew Lunn pointed out that even if it's documented that
ethnl_parse_header() takes reference to network device if it fills it
into the target structure, its name doesn't make it apparent so that
corresponding dev_put() looks like mismatched.

Rename the function ethnl_parse_header_dev_get() to indicate that it
takes a reference.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: add WOL_NTF notification

Send ETHTOOL_MSG_WOL_NTF notification whenever wake-on-lan settings of
a device are modified using ETHTOOL_MSG_WOL_SET netlink message or
ETHTOOL_SWOL ioctl request.

As notifications can be received by anyone, do not include SecureOn(tm)
password in notification messages.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: set wake-on-lan settings with WOL_SET request

Implement WOL_SET netlink request to set wake-on-lan settings. This is
equivalent to ETHTOOL_SWOL ioctl request.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

ethtool: provide WoL settings with WOL_GET request

Implement WOL_GET request to get wake-on-lan settings for a device,
traditionally available via ETHTOOL_GWOL ioctl request.

As part of the implementation, provide symbolic names for wake-on-line
modes as ETH_SS_WOL_MODES string set.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>