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) \ @@ -1357,6 +1368,22 @@ static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) return nla_put(skb, attrtype, sizeof(u32), &tmp); } +/** + * 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 @@ -1511,6 +1538,22 @@ static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); } +/** + * 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 @@ -1667,6 +1710,17 @@ static inline u64 nla_get_u64(const struct nlattr *nla) return tmp; } +/** + * 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 @@ -1729,6 +1783,17 @@ static inline s64 nla_get_s64(const struct nlattr *nla) return tmp; } +/** + * 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);