2020-04-30 20:14:35

by Johannes Berg

[permalink] [raw]
Subject: [PATCH v2 7/8] netlink: factor out policy range helpers

From: Johannes Berg <[email protected]>

Add helpers to get the policy's signed/unsigned range
validation data.

Signed-off-by: Johannes Berg <[email protected]>
---
v2:
- context-only conflict fix for the warn condition change
---
include/net/netlink.h | 5 +++
lib/nlattr.c | 95 +++++++++++++++++++++++++++++++++----------
2 files changed, 79 insertions(+), 21 deletions(-)

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 4d4a733f1e8d..557b67f1db99 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -1928,4 +1928,9 @@ static inline bool nla_is_last(const struct nlattr *nla, int rem)
return nla->nla_len == rem;
}

+void nla_get_range_unsigned(const struct nla_policy *pt,
+ struct netlink_range_validation *range);
+void nla_get_range_signed(const struct nla_policy *pt,
+ struct netlink_range_validation_signed *range);
+
#endif
diff --git a/lib/nlattr.c b/lib/nlattr.c
index 6dcbe1bedd3b..bc5b5cf608c4 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -111,26 +111,40 @@ static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
return 0;
}

-static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
- const struct nlattr *nla,
- struct netlink_ext_ack *extack)
+void nla_get_range_unsigned(const struct nla_policy *pt,
+ struct netlink_range_validation *range)
{
- struct netlink_range_validation _range = {
- .min = 0,
- .max = U64_MAX,
- }, *range = &_range;
- u64 value;
-
WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
(pt->min < 0 || pt->max < 0));

+ range->min = 0;
+
+ switch (pt->type) {
+ case NLA_U8:
+ range->max = U8_MAX;
+ break;
+ case NLA_U16:
+ range->max = U16_MAX;
+ break;
+ case NLA_U32:
+ range->max = U32_MAX;
+ break;
+ case NLA_U64:
+ case NLA_MSECS:
+ range->max = U64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
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;
+ *range = *pt->range;
break;
case NLA_VALIDATE_MIN:
range->min = pt->min;
@@ -138,7 +152,17 @@ static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
case NLA_VALIDATE_MAX:
range->max = pt->max;
break;
+ default:
+ break;
}
+}
+
+static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct netlink_range_validation range;
+ u64 value;

switch (pt->type) {
case NLA_U8:
@@ -158,7 +182,9 @@ static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
return -EINVAL;
}

- if (value < range->min || value > range->max) {
+ nla_get_range_unsigned(pt, &range);
+
+ if (value < range.min || value > range.max) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"integer out of range");
return -ERANGE;
@@ -167,15 +193,30 @@ static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
return 0;
}

-static int nla_validate_int_range_signed(const struct nla_policy *pt,
- const struct nlattr *nla,
- struct netlink_ext_ack *extack)
+void nla_get_range_signed(const struct nla_policy *pt,
+ struct netlink_range_validation_signed *range)
{
- struct netlink_range_validation_signed _range = {
- .min = S64_MIN,
- .max = S64_MAX,
- }, *range = &_range;
- s64 value;
+ switch (pt->type) {
+ case NLA_S8:
+ range->min = S8_MIN;
+ range->max = S8_MAX;
+ break;
+ case NLA_S16:
+ range->min = S16_MIN;
+ range->max = S16_MAX;
+ break;
+ case NLA_S32:
+ range->min = S32_MIN;
+ range->max = S32_MAX;
+ break;
+ case NLA_S64:
+ range->min = S64_MIN;
+ range->max = S64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }

switch (pt->validation_type) {
case NLA_VALIDATE_RANGE:
@@ -183,7 +224,7 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt,
range->max = pt->max;
break;
case NLA_VALIDATE_RANGE_PTR:
- range = pt->range_signed;
+ *range = *pt->range_signed;
break;
case NLA_VALIDATE_MIN:
range->min = pt->min;
@@ -191,7 +232,17 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt,
case NLA_VALIDATE_MAX:
range->max = pt->max;
break;
+ default:
+ break;
}
+}
+
+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;
+ s64 value;

switch (pt->type) {
case NLA_S8:
@@ -210,7 +261,9 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt,
return -EINVAL;
}

- if (value < range->min || value > range->max) {
+ nla_get_range_signed(pt, &range);
+
+ if (value < range.min || value > range.max) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"integer out of range");
return -ERANGE;
--
2.25.1