diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netlink.h | 67 |
1 files changed, 64 insertions, 3 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 3698ca8ff92c..d34ceeba82a8 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -188,9 +188,19 @@ enum { #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) +enum nla_policy_validation { + NLA_VALIDATE_NONE, + NLA_VALIDATE_RANGE, + NLA_VALIDATE_MIN, + NLA_VALIDATE_MAX, +}; + /** * struct nla_policy - attribute validation policy * @type: Type of attribute or NLA_UNSPEC + * @validation_type: type of attribute validation done in addition to + * type-specific validation (e.g. range), see + * &enum nla_policy_validation * @len: Type specific length of payload * * Policies are defined as arrays of this struct, the array must be @@ -238,7 +248,26 @@ enum { * 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 + * All other Unused - but note that it's a union + * + * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX + * and NLA_POLICY_RANGE: + * NLA_U8, + * NLA_U16, + * NLA_U32, + * NLA_U64, + * NLA_S8, + * NLA_S16, + * NLA_S32, + * NLA_S64 These are used depending on the validation_type + * field, if that is min/max/range then the minimum, + * maximum and both are used (respectively) to check + * the value of the integer attribute. + * Note that in the interest of code simplicity and + * struct size both limits are s16, so you cannot + * enforce a range that doesn't fall within the range + * of s16 - do that as usual in the code instead. + * All other Unused - but note that it's a union * * Example: * static const struct nla_policy my_policy[ATTR_MAX+1] = { @@ -249,9 +278,15 @@ enum { * }; */ struct nla_policy { - u16 type; + u8 type; + u8 validation_type; u16 len; - const void *validation_data; + union { + const void *validation_data; + struct { + s16 min, max; + }; + }; }; #define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len } @@ -266,6 +301,32 @@ struct nla_policy { #define NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } +#define __NLA_ENSURE(condition) (sizeof(char[1 - 2*!(condition)]) - 1) +#define NLA_ENSURE_INT_TYPE(tp) \ + (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ + tp == NLA_S16 || tp == NLA_U16 || \ + tp == NLA_S32 || tp == NLA_U32 || \ + tp == NLA_S64 || tp == NLA_U64) + tp) + +#define NLA_POLICY_RANGE(tp, _min, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_RANGE, \ + .min = _min, \ + .max = _max \ +} + +#define NLA_POLICY_MIN(tp, _min) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MIN, \ + .min = _min, \ +} + +#define NLA_POLICY_MAX(tp, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MAX, \ + .max = _max, \ +} + /** * struct nl_info - netlink source information * @nlh: Netlink message header of original request |