linux-toradex.git/include/net/netlink.h, branch v5.0

netlink: replace __NLA_ENSURE implementation

2018-10-12T18:00:22+00:00

We already have BUILD_BUG_ON_ZERO() which I just hadn't found
before, so we should use it here instead of open-coding another
implementation thereof.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: Add strict version of nlmsg_parse and nla_parse

2018-10-08T17:39:04+00:00

nla_parse is currently lenient on message parsing, allowing type to be 0
or greater than max expected and only logging a message

    "netlink: %d bytes leftover after parsing attributes in process `%s'."

if the netlink message has unknown data at the end after parsing. What this
could mean is that the header at the front of the attributes is actually
wrong and the parsing is shifted from what is expected.

Add a new strict version that actually fails with EINVAL if there are any
bytes remaining after the parsing loop completes, if the atttrbitue type
is 0 or greater than max expected.

Signed-off-by: David Ahern 
Acked-by: Christian Brauner 
Signed-off-by: David S. Miller

netlink: Add extack message to nlmsg_parse for invalid header length

2018-10-08T17:39:03+00:00

Give a user a reason why EINVAL is returned in nlmsg_parse.

Signed-off-by: David Ahern 
Acked-by: Christian Brauner 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-10-04T04:00:17+00:00

Minor conflict in net/core/rtnetlink.c, David Ahern's bug fix in 'net'
overlapped the renaming of a netlink attribute in net-next.

Signed-off-by: David S. Miller

netlink: add validation function to policy

2018-10-02T06:05:31+00:00

Add the ability to have an arbitrary validation function attached
to a netlink policy that doesn't already use the validation_data
pointer in another way.

This can be useful to validate for example the content of a binary
attribute, like in nl80211 the "(information) elements", which must
be valid streams of "u8 type, u8 length, u8 value[length]".

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: add attribute range validation to policy

2018-10-02T06:05:31+00:00

Without further bloating the policy structs, we can overload
the `validation_data' pointer with a struct of s16 min, max
and use those to validate ranges in NLA_{U,S}{8,16,32,64}
attributes.

It may sound strange to validate NLA_U32 with a s16 max, but
in many cases NLA_U32 is used for enums etc. since there's no
size benefit in using a smaller attribute width anyway, due
to netlink attribute alignment; in cases like that it's still
useful, particularly when the attribute really transports an
enum value.

Doing so lets us remove quite a bit of validation code, if we
can be sure that these attributes aren't used by userspace in
places where they're ignored today.

To achieve all this, split the 'type' field and introduce a
new 'validation_type' field which indicates what further
validation (beyond the validation prescribed by the type of
the attribute) is done. This currently allows for no further
validation (the default), as well as min, max and range checks.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: fix typo in nla_parse_nested() comment

2018-09-29T18:48:26+00:00

Fix a simple typo: attribuets -> attributes

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: add nested array policy validation

2018-09-28T17:24:39+00:00

Sometimes nested netlink attributes are just used as arrays, with
the nla_type() of each not being used; we have this in nl80211 and
e.g. NFTA_SET_ELEM_LIST_ELEMENTS.

Add the ability to validate this type of message directly in the
policy, by adding the type NLA_NESTED_ARRAY which does exactly
this: require a first level of nesting but ignore the attribute
type, and then inside each require a second level of nested and
validate those attributes against a given policy (if present).

Note that some nested array types actually require that all of
the entries have the same index, this is possible to express in
a nested policy already, apart from the validation that only the
one allowed type is used.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: allow NLA_NESTED to specify nested policy to validate

2018-09-28T17:24:39+00:00

Now that we have a validation_data pointer, and the len field in
the policy is unused for NLA_NESTED, we can allow using them both
to have nested validation. This can be nice in code, although we
still have to use nla_parse_nested() or similar which would also
take a policy; however, it also serves as documentation in the
policy without requiring a look at the code.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

netlink: make validation_data const

2018-09-28T17:24:39+00:00

The validation data is only used within the policy that
should usually already be const, and isn't changed in any
code that uses it. Therefore, make the validation_data
pointer const.

While at it, remove the duplicate variable in the bitfield
validation that I'd otherwise have to change to const.

Reviewed-by: David Ahern 
Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller