diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2018-09-17 11:57:29 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-09-18 19:51:29 -0700 |
| commit | b60b87fc2996240e298529a46e122ef62ef9c27f (patch) | |
| tree | a39a2b84798368f1c53b412586eff77e6e3b1673 /include/net/netlink.h | |
| parent | 568b742a9d9888aca876b6ad9fa45490f18bee0a (diff) | |
netlink: add ethernet address policy types
Commonly, ethernet addresses are just using a policy of
{ .len = ETH_ALEN }
which leaves userspace free to send more data than it should,
which may hide bugs.
Introduce NLA_EXACT_LEN which checks for exact size, rejecting
the attribute if it's not exactly that length. Also add
NLA_EXACT_LEN_WARN which requires the minimum length and will
warn on longer attributes, for backward compatibility.
Use these to define NLA_POLICY_ETH_ADDR (new strict policy) and
NLA_POLICY_ETH_ADDR_COMPAT (compatible policy with warning);
these are used like this:
static const struct nla_policy <name>[...] = {
[NL_ATTR_NAME] = NLA_POLICY_ETH_ADDR,
...
};
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/netlink.h')
| -rw-r--r-- | include/net/netlink.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index b318b0a9f6c3..318b1ded3833 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -181,6 +181,8 @@ enum { NLA_S64, NLA_BITFIELD32, NLA_REJECT, + NLA_EXACT_LEN, + NLA_EXACT_LEN_WARN, __NLA_TYPE_MAX, }; @@ -211,6 +213,10 @@ enum { * just like "All other" * NLA_BITFIELD32 Unused * NLA_REJECT Unused + * NLA_EXACT_LEN Attribute must have exactly this length, otherwise + * it is rejected. + * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning + * is logged if it is longer, shorter is rejected. * All other Minimum length of attribute payload * * Meaning of `validation_data' field: @@ -236,6 +242,13 @@ struct nla_policy { void *validation_data; }; +#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } +#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \ + .len = _len } + +#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) +#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) + /** * struct nl_info - netlink source information * @nlh: Netlink message header of original request |