netlink: extend policy range validation
Using a pointer to a struct indicating the min/max values,
extend the ability to do range validation for arbitrary
values. Small values in the s16 range can be kept in the
policy directly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/nlattr.c b/lib/nlattr.c
index 7f7ebd8..a8beb17 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -111,17 +111,34 @@ static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
return 0;
}
-static int nla_validate_int_range(const struct nla_policy *pt,
- const struct nlattr *nla,
- struct netlink_ext_ack *extack)
+static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
{
- bool validate_min, validate_max;
- s64 value;
+ struct netlink_range_validation _range = {
+ .min = 0,
+ .max = U64_MAX,
+ }, *range = &_range;
+ u64 value;
- validate_min = pt->validation_type == NLA_VALIDATE_RANGE ||
- pt->validation_type == NLA_VALIDATE_MIN;
- validate_max = pt->validation_type == NLA_VALIDATE_RANGE ||
- pt->validation_type == NLA_VALIDATE_MAX;
+ WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
+ (pt->min < 0 || pt->max < 0));
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ range = pt->range;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ }
switch (pt->type) {
case NLA_U8:
@@ -133,6 +150,49 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_U32:
value = nla_get_u32(nla);
break;
+ case NLA_U64:
+ value = nla_get_u64(nla);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (value < range->min || value > range->max) {
+ NL_SET_ERR_MSG_ATTR(extack, nla,
+ "integer out of range");
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+static int nla_validate_int_range_signed(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct netlink_range_validation_signed _range = {
+ .min = S64_MIN,
+ .max = S64_MAX,
+ }, *range = &_range;
+ s64 value;
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ range = pt->range_signed;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ }
+
+ switch (pt->type) {
case NLA_S8:
value = nla_get_s8(nla);
break;
@@ -145,22 +205,11 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_S64:
value = nla_get_s64(nla);
break;
- case NLA_U64:
- /* treat this one specially, since it may not fit into s64 */
- if ((validate_min && nla_get_u64(nla) < pt->min) ||
- (validate_max && nla_get_u64(nla) > pt->max)) {
- NL_SET_ERR_MSG_ATTR(extack, nla,
- "integer out of range");
- return -ERANGE;
- }
- return 0;
default:
- WARN_ON(1);
return -EINVAL;
}
- if ((validate_min && value < pt->min) ||
- (validate_max && value > pt->max)) {
+ if (value < range->min || value > range->max) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"integer out of range");
return -ERANGE;
@@ -169,6 +218,27 @@ static int nla_validate_int_range(const struct nla_policy *pt,
return 0;
}
+static int nla_validate_int_range(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ switch (pt->type) {
+ case NLA_U8:
+ case NLA_U16:
+ case NLA_U32:
+ case NLA_U64:
+ return nla_validate_int_range_unsigned(pt, nla, extack);
+ case NLA_S8:
+ case NLA_S16:
+ case NLA_S32:
+ case NLA_S64:
+ return nla_validate_int_range_signed(pt, nla, extack);
+ default:
+ WARN_ON(1);
+ return -EINVAL;
+ }
+}
+
static int validate_nla(const struct nlattr *nla, int maxtype,
const struct nla_policy *policy, unsigned int validate,
struct netlink_ext_ack *extack, unsigned int depth)
@@ -348,6 +418,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
case NLA_VALIDATE_NONE:
/* nothing to do */
break;
+ case NLA_VALIDATE_RANGE_PTR:
case NLA_VALIDATE_RANGE:
case NLA_VALIDATE_MIN:
case NLA_VALIDATE_MAX: