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author | Johannes Berg <johannes.berg@intel.com> | 2018-09-26 12:15:34 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-09-28 20:24:39 +0300 |
commit | 1501d13596b92d6d1f0ea5e104be838188b6e026 (patch) | |
tree | 8cce360cee760f94af43ef1c236cdbbbbf57a4d3 /include | |
parent | 9a659a35ba177cec30676e170fb6ed98157bcb0d (diff) | |
download | linux-1501d13596b92d6d1f0ea5e104be838188b6e026.tar.xz |
netlink: add nested array policy validation
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 <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r-- | include/net/netlink.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 91907852da1c..3698ca8ff92c 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -172,6 +172,7 @@ enum { NLA_FLAG, NLA_MSECS, NLA_NESTED, + NLA_NESTED_ARRAY, NLA_NUL_STRING, NLA_BINARY, NLA_S8, @@ -200,7 +201,8 @@ enum { * NLA_NUL_STRING Maximum length of string (excluding NUL) * NLA_FLAG Unused * NLA_BINARY Maximum length of attribute payload - * NLA_NESTED Length verification is done by checking len of + * NLA_NESTED, + * NLA_NESTED_ARRAY Length verification is done by checking len of * nested header (or empty); len field is used if * validation_data is also used, for the max attr * number in the nested policy. @@ -230,6 +232,12 @@ enum { * `len' to the max attribute number. * Note that nla_parse() will validate, but of course not * parse, the nested sub-policies. + * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set + * `len' to the max attribute number. The difference to + * NLA_NESTED is the structure - NLA_NESTED has the + * nested attributes directly inside, while an array has + * the nested attributes at another level down and the + * attributes directly in the nesting don't matter. * All other Unused * * Example: @@ -255,6 +263,8 @@ struct nla_policy { #define NLA_POLICY_NESTED(maxattr, policy) \ { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } +#define NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ + { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } /** * struct nl_info - netlink source information |