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-rw-r--r--Documentation/userspace-api/netlink/specs.rst18
-rw-r--r--include/net/netlink.h69
-rw-r--r--include/uapi/linux/netlink.h5
-rw-r--r--lib/nlattr.c22
-rw-r--r--net/netlink/policy.c14
5 files changed, 121 insertions, 7 deletions
diff --git a/Documentation/userspace-api/netlink/specs.rst b/Documentation/userspace-api/netlink/specs.rst
index 40dd7442d2c3..c1b951649113 100644
--- a/Documentation/userspace-api/netlink/specs.rst
+++ b/Documentation/userspace-api/netlink/specs.rst
@@ -403,10 +403,21 @@ This section describes the attribute types supported by the ``genetlink``
compatibility level. Refer to documentation of different levels for additional
attribute types.
-Scalar integer types
+Common integer types
--------------------
-Fixed-width integer types:
+``sint`` and ``uint`` represent signed and unsigned 64 bit integers.
+If the value can fit on 32 bits only 32 bits are carried in netlink
+messages, otherwise full 64 bits are carried. Note that the payload
+is only aligned to 4B, so the full 64 bit value may be unaligned!
+
+Common integer types should be preferred over fix-width types in majority
+of cases.
+
+Fix-width integer types
+-----------------------
+
+Fixed-width integer types include:
``u8``, ``u16``, ``u32``, ``u64``, ``s8``, ``s16``, ``s32``, ``s64``.
Note that types smaller than 32 bit should be avoided as using them
@@ -416,6 +427,9 @@ See :ref:`pad_type` for padding of 64 bit attributes.
The payload of the attribute is the integer in host order unless ``byte-order``
specifies otherwise.
+64 bit values are usually aligned by the kernel but it is recommended
+that the user space is able to deal with unaligned values.
+
.. _pad_type:
pad
diff --git a/include/net/netlink.h b/include/net/netlink.h
index 8a7cd1170e1f..aba2b162a226 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -128,6 +128,8 @@
* nla_len(nla) length of attribute payload
*
* Attribute Payload Access for Basic Types:
+ * nla_get_uint(nla) get payload for a uint attribute
+ * nla_get_sint(nla) get payload for a sint attribute
* nla_get_u8(nla) get payload for a u8 attribute
* nla_get_u16(nla) get payload for a u16 attribute
* nla_get_u32(nla) get payload for a u32 attribute
@@ -183,6 +185,8 @@ enum {
NLA_REJECT,
NLA_BE16,
NLA_BE32,
+ NLA_SINT,
+ NLA_UINT,
__NLA_TYPE_MAX,
};
@@ -229,6 +233,7 @@ enum nla_policy_validation {
* nested header (or empty); len field is used if
* nested_policy is also used, for the max attr
* number in the nested policy.
+ * NLA_SINT, NLA_UINT,
* NLA_U8, NLA_U16,
* NLA_U32, NLA_U64,
* NLA_S8, NLA_S16,
@@ -260,12 +265,14 @@ enum nla_policy_validation {
* while an array has the nested attributes at another
* level down and the attribute types directly in the
* nesting don't matter.
+ * NLA_UINT,
* NLA_U8,
* NLA_U16,
* NLA_U32,
* NLA_U64,
* NLA_BE16,
* NLA_BE32,
+ * NLA_SINT,
* NLA_S8,
* NLA_S16,
* NLA_S32,
@@ -280,6 +287,7 @@ enum nla_policy_validation {
* or NLA_POLICY_FULL_RANGE_SIGNED() macros instead.
* Use the NLA_POLICY_MIN(), NLA_POLICY_MAX() and
* NLA_POLICY_RANGE() macros.
+ * NLA_UINT,
* NLA_U8,
* NLA_U16,
* NLA_U32,
@@ -288,6 +296,7 @@ enum nla_policy_validation {
* to a struct netlink_range_validation that indicates
* the min/max values.
* Use NLA_POLICY_FULL_RANGE().
+ * NLA_SINT,
* NLA_S8,
* NLA_S16,
* NLA_S32,
@@ -377,9 +386,11 @@ struct nla_policy {
#define __NLA_IS_UINT_TYPE(tp) \
(tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || \
- tp == NLA_U64 || tp == NLA_BE16 || tp == NLA_BE32)
+ tp == NLA_U64 || tp == NLA_UINT || \
+ tp == NLA_BE16 || tp == NLA_BE32)
#define __NLA_IS_SINT_TYPE(tp) \
- (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
+ (tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64 || \
+ tp == NLA_SINT)
#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
#define NLA_ENSURE_UINT_TYPE(tp) \
@@ -1358,6 +1369,22 @@ static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
}
/**
+ * nla_put_uint - Add a variable-size unsigned int to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @value: numeric value
+ */
+static inline int nla_put_uint(struct sk_buff *skb, int attrtype, u64 value)
+{
+ u64 tmp64 = value;
+ u32 tmp32 = value;
+
+ if (tmp64 == tmp32)
+ return nla_put_u32(skb, attrtype, tmp32);
+ return nla_put(skb, attrtype, sizeof(u64), &tmp64);
+}
+
+/**
* nla_put_be32 - Add a __be32 netlink attribute to a socket buffer
* @skb: socket buffer to add attribute to
* @attrtype: attribute type
@@ -1512,6 +1539,22 @@ static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value,
}
/**
+ * nla_put_sint - Add a variable-size signed int to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @value: numeric value
+ */
+static inline int nla_put_sint(struct sk_buff *skb, int attrtype, s64 value)
+{
+ s64 tmp64 = value;
+ s32 tmp32 = value;
+
+ if (tmp64 == tmp32)
+ return nla_put_s32(skb, attrtype, tmp32);
+ return nla_put(skb, attrtype, sizeof(s64), &tmp64);
+}
+
+/**
* nla_put_string - Add a string netlink attribute to a socket buffer
* @skb: socket buffer to add attribute to
* @attrtype: attribute type
@@ -1668,6 +1711,17 @@ static inline u64 nla_get_u64(const struct nlattr *nla)
}
/**
+ * nla_get_uint - return payload of uint attribute
+ * @nla: uint netlink attribute
+ */
+static inline u64 nla_get_uint(const struct nlattr *nla)
+{
+ if (nla_len(nla) == sizeof(u32))
+ return nla_get_u32(nla);
+ return nla_get_u64(nla);
+}
+
+/**
* nla_get_be64 - return payload of __be64 attribute
* @nla: __be64 netlink attribute
*/
@@ -1730,6 +1784,17 @@ static inline s64 nla_get_s64(const struct nlattr *nla)
}
/**
+ * nla_get_sint - return payload of uint attribute
+ * @nla: uint netlink attribute
+ */
+static inline s64 nla_get_sint(const struct nlattr *nla)
+{
+ if (nla_len(nla) == sizeof(s32))
+ return nla_get_s32(nla);
+ return nla_get_s64(nla);
+}
+
+/**
* nla_get_flag - return payload of flag attribute
* @nla: flag netlink attribute
*/
diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index e2ae82e3f9f7..f87aaf28a649 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -298,6 +298,8 @@ struct nla_bitfield32 {
* entry has attributes again, the policy for those inner ones
* and the corresponding maxtype may be specified.
* @NL_ATTR_TYPE_BITFIELD32: &struct nla_bitfield32 attribute
+ * @NL_ATTR_TYPE_SINT: 32-bit or 64-bit signed attribute, aligned to 4B
+ * @NL_ATTR_TYPE_UINT: 32-bit or 64-bit unsigned attribute, aligned to 4B
*/
enum netlink_attribute_type {
NL_ATTR_TYPE_INVALID,
@@ -322,6 +324,9 @@ enum netlink_attribute_type {
NL_ATTR_TYPE_NESTED_ARRAY,
NL_ATTR_TYPE_BITFIELD32,
+
+ NL_ATTR_TYPE_SINT,
+ NL_ATTR_TYPE_UINT,
};
/**
diff --git a/lib/nlattr.c b/lib/nlattr.c
index 7a2b6c38fd59..dc15e7888fc1 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -134,6 +134,7 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
range->max = U32_MAX;
break;
case NLA_U64:
+ case NLA_UINT:
case NLA_MSECS:
range->max = U64_MAX;
break;
@@ -183,6 +184,9 @@ static int nla_validate_range_unsigned(const struct nla_policy *pt,
case NLA_U64:
value = nla_get_u64(nla);
break;
+ case NLA_UINT:
+ value = nla_get_uint(nla);
+ break;
case NLA_MSECS:
value = nla_get_u64(nla);
break;
@@ -248,6 +252,7 @@ void nla_get_range_signed(const struct nla_policy *pt,
range->max = S32_MAX;
break;
case NLA_S64:
+ case NLA_SINT:
range->min = S64_MIN;
range->max = S64_MAX;
break;
@@ -295,6 +300,9 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt,
case NLA_S64:
value = nla_get_s64(nla);
break;
+ case NLA_SINT:
+ value = nla_get_sint(nla);
+ break;
default:
return -EINVAL;
}
@@ -320,6 +328,7 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_U16:
case NLA_U32:
case NLA_U64:
+ case NLA_UINT:
case NLA_MSECS:
case NLA_BINARY:
case NLA_BE16:
@@ -329,6 +338,7 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_S16:
case NLA_S32:
case NLA_S64:
+ case NLA_SINT:
return nla_validate_int_range_signed(pt, nla, extack);
default:
WARN_ON(1);
@@ -355,6 +365,9 @@ static int nla_validate_mask(const struct nla_policy *pt,
case NLA_U64:
value = nla_get_u64(nla);
break;
+ case NLA_UINT:
+ value = nla_get_uint(nla);
+ break;
case NLA_BE16:
value = ntohs(nla_get_be16(nla));
break;
@@ -433,6 +446,15 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
goto out_err;
break;
+ case NLA_SINT:
+ case NLA_UINT:
+ if (attrlen != sizeof(u32) && attrlen != sizeof(u64)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+ break;
+
case NLA_BITFIELD32:
if (attrlen != sizeof(struct nla_bitfield32))
goto out_err;
diff --git a/net/netlink/policy.c b/net/netlink/policy.c
index e2f111edf66c..1f8909c16f14 100644
--- a/net/netlink/policy.c
+++ b/net/netlink/policy.c
@@ -230,6 +230,8 @@ int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt)
case NLA_S16:
case NLA_S32:
case NLA_S64:
+ case NLA_SINT:
+ case NLA_UINT:
/* maximum is common, u64 min/max with padding */
return common +
2 * (nla_attr_size(0) + nla_attr_size(sizeof(u64)));
@@ -288,6 +290,7 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state,
case NLA_U16:
case NLA_U32:
case NLA_U64:
+ case NLA_UINT:
case NLA_MSECS: {
struct netlink_range_validation range;
@@ -297,8 +300,10 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state,
type = NL_ATTR_TYPE_U16;
else if (pt->type == NLA_U32)
type = NL_ATTR_TYPE_U32;
- else
+ else if (pt->type == NLA_U64)
type = NL_ATTR_TYPE_U64;
+ else
+ type = NL_ATTR_TYPE_UINT;
if (pt->validation_type == NLA_VALIDATE_MASK) {
if (nla_put_u64_64bit(skb, NL_POLICY_TYPE_ATTR_MASK,
@@ -320,7 +325,8 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state,
case NLA_S8:
case NLA_S16:
case NLA_S32:
- case NLA_S64: {
+ case NLA_S64:
+ case NLA_SINT: {
struct netlink_range_validation_signed range;
if (pt->type == NLA_S8)
@@ -329,8 +335,10 @@ __netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state,
type = NL_ATTR_TYPE_S16;
else if (pt->type == NLA_S32)
type = NL_ATTR_TYPE_S32;
- else
+ else if (pt->type == NLA_S64)
type = NL_ATTR_TYPE_S64;
+ else
+ type = NL_ATTR_TYPE_SINT;
nla_get_range_signed(pt, &range);
generated by cgit (git 2.34.1) at 2024-05-27 19:10:07 +0000