linux.git/include/net/netlink.h, branch v6.1

netlink: introduce bigendian integer types

2022-11-02T04:29:06+00:00

Jakub reported that the addition of the "network_byte_order"
member in struct nla_policy increases size of 32bit platforms.

Instead of scraping the bit from elsewhere Johannes suggested
to add explicit NLA_BE types instead, so do this here.

NLA_POLICY_MAX_BE() macro is removed again, there is no need
for it: NLA_POLICY_MAX(NLA_BE.., ..) will do the right thing.

NLA_BE64 can be added later.

Fixes: 08724ef69907 ("netlink: introduce NLA_POLICY_MAX_BE")
Reported-by: Jakub Kicinski 
Suggested-by: Johannes Berg 
Signed-off-by: Florian Westphal 
Link: https://lore.kernel.org/r/20221031123407.9158-1-fw@strlen.de
Signed-off-by: Jakub Kicinski

netlink: hide validation union fields from kdoc

2022-10-29T03:19:15+00:00

Mark the validation fields as private, users shouldn't set
them directly and they are too complicated to explain in
a more succinct way (there's already a long explanation
in the comment above).

The strict_start_type field is set directly and has a dedicated
comment so move that above the "private" section.

Link: https://lore.kernel.org/r/20221027212107.2639255-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

netlink: introduce NLA_POLICY_MAX_BE

2022-09-07T11:33:43+00:00

netlink allows to specify allowed ranges for integer types.
Unfortunately, nfnetlink passes integers in big endian, so the existing
NLA_POLICY_MAX() cannot be used.

At the moment, nfnetlink users, such as nf_tables, need to resort to
programmatic checking via helpers such as nft_parse_u32_check().

This is both cumbersome and error prone.  This adds NLA_POLICY_MAX_BE
which adds range check support for BE16, BE32 and BE64 integers.

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

netlink: fix some kernel-doc comments

2022-08-25T01:46:16+00:00

Modify the comment of input parameter of nlmsg_ and nla_ function.

Signed-off-by: Zhengchao Shao 
Link: https://lore.kernel.org/r/20220824013621.365103-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski

net: netlink: add the case when nlh is NULL

2021-07-27T10:43:50+00:00

Add the case when nlh is NULL in nlmsg_report(),
so that the caller doesn't need to deal with this case.

Signed-off-by: Yajun Deng 
Signed-off-by: David S. Miller

treewide: rename nla_strlcpy to nla_strscpy.

2020-11-16T16:08:54+00:00

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.

Signed-off-by: Francis Laniel 
Reviewed-by: Kees Cook 
Signed-off-by: Jakub Kicinski

Modify return value of nla_strlcpy to match that of strscpy.

2020-11-16T16:08:54+00:00

nla_strlcpy now returns -E2BIG if src was truncated when written to dst.
It also returns this error value if dstsize is 0 or higher than INT_MAX.

For example, if src is "foo\0" and dst is 3 bytes long, the result will be:
1. "foG" after memcpy (G means garbage).
2. "fo\0" after memset.
3. -E2BIG is returned because src was not completely written into dst.

The callers of nla_strlcpy were modified to take into account this modification.

Signed-off-by: Francis Laniel 
Reviewed-by: Kees Cook 
Signed-off-by: Jakub Kicinski

netlink: export policy in extended ACK

2020-10-10T03:22:32+00:00

Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK
to advertise the policy, e.g. if an attribute was out of range,
you'll know the range that's permissible.

Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL()
macros to set this, since realistically it's only useful to do
this when the bad attribute (offset) is also returned.

Use it in lib/nlattr.c which practically does all the policy
validation.

v2:
 - add and use netlink_policy_dump_attr_size_estimate()
v3:
 - remove redundant break
v4:
 - really remove redundant break ... sorry

Reviewed-by: Jakub Kicinski 
Signed-off-by: Johannes Berg 
Signed-off-by: Jakub Kicinski

netlink: add mask validation

2020-10-06T13:25:55+00:00

We don't have good validation policy for existing unsigned int attrs
which serve as flags (for new ones we could use NLA_BITFIELD32).
With increased use of policy dumping having the validation be
expressed as part of the policy is important. Add validation
policy in form of a mask of supported/valid bits.

Support u64 in the uAPI to be future-proof, but really for now
the embedded mask member can only hold 32 bits, so anything with
bit 32+ set will always fail validation.

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

netlink: create helpers for checking type is an int

2020-10-06T13:25:55+00:00

There's a number of policies which check if type is a uint or sint.
Factor the checking against the list of value sizes to a helper
for easier reuse.

v2: - new patch

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller