[PATCH 5.15 341/570] netlink: introduce bigendian integer types

Greg Kroah-Hartman
2026-04-13T16:32:43Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit ecaf75ffd5f5db320d8b1da0198eef5a5ce64a3f ]

Jakub reported that the addition of the "network_byte_order"
member in struct nla_policy increases size of 32bit platforms.

Instead of scraping the bit from elsewhere Johannes suggested
to add explicit NLA_BE types instead, so do this here.

NLA_POLICY_MAX_BE() macro is removed again, there is no need
for it: NLA_POLICY_MAX(NLA_BE.., ..) will do the right thing.

NLA_BE64 can be added later.

Fixes: 08724ef69907 ("netlink: introduce NLA_POLICY_MAX_BE")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20221031123407.9158-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 8f15b5071b45 ("netfilter: ctnetlink: use netlink policy range checks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/netlink.h | 19 +++++++++--------
lib/nlattr.c | 41 ++++++++++++++-----------------------
net/netfilter/nft_payload.c | 6 +++---
3 files changed, 28 insertions(+), 38 deletions(-)

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 8c67db47556e2..356b805f50151 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -181,6 +181,8 @@ enum {
NLA_S64,
NLA_BITFIELD32,
NLA_REJECT,
+ NLA_BE16,
+ NLA_BE32,
__NLA_TYPE_MAX,
};

@@ -231,6 +233,7 @@ enum nla_policy_validation {
* NLA_U32, NLA_U64,
* NLA_S8, NLA_S16,
* NLA_S32, NLA_S64,
+ * NLA_BE16, NLA_BE32,
* NLA_MSECS Leaving the length field zero will verify the
* given type fits, using it verifies minimum length
* just like "All other"
@@ -261,6 +264,8 @@ enum nla_policy_validation {
* NLA_U16,
* NLA_U32,
* NLA_U64,
+ * NLA_BE16,
+ * NLA_BE32,
* NLA_S8,
* NLA_S16,
* NLA_S32,
@@ -349,7 +354,6 @@ struct nla_policy {
struct netlink_range_validation_signed *range_signed;
struct {
s16 min, max;
- u8 network_byte_order:1;
};
int (*validate)(const struct nlattr *attr,
struct netlink_ext_ack *extack);
@@ -374,6 +378,8 @@ struct nla_policy {
(tp == NLA_U8 || tp == NLA_U16 || tp == NLA_U32 || tp == NLA_U64)
#define __NLA_IS_SINT_TYPE(tp) \
(tp == NLA_S8 || tp == NLA_S16 || tp == NLA_S32 || tp == NLA_S64)
+#define __NLA_IS_BEINT_TYPE(tp) \
+ (tp == NLA_BE16 || tp == NLA_BE32)

#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
#define NLA_ENSURE_UINT_TYPE(tp) \
@@ -387,6 +393,7 @@ struct nla_policy {
#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp) \
(__NLA_ENSURE(__NLA_IS_UINT_TYPE(tp) || \
__NLA_IS_SINT_TYPE(tp) || \
+ __NLA_IS_BEINT_TYPE(tp) || \
tp == NLA_MSECS || \
tp == NLA_BINARY) + tp)
#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \
@@ -394,6 +401,8 @@ struct nla_policy {
tp != NLA_REJECT && \
tp != NLA_NESTED && \
tp != NLA_NESTED_ARRAY) + tp)
+#define NLA_ENSURE_BEINT_TYPE(tp) \
+ (__NLA_ENSURE(__NLA_IS_BEINT_TYPE(tp)) + tp)

#define NLA_POLICY_RANGE(tp, _min, _max) { \
.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
@@ -424,14 +433,6 @@ struct nla_policy {
.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp), \
.validation_type = NLA_VALIDATE_MAX, \
.max = _max, \
- .network_byte_order = 0, \
-}
-
-#define NLA_POLICY_MAX_BE(tp, _max) { \
- .type = NLA_ENSURE_UINT_TYPE(tp), \
- .validation_type = NLA_VALIDATE_MAX, \
- .max = _max, \
- .network_byte_order = 1, \
}

#define NLA_POLICY_MASK(tp, _mask) { \
diff --git a/lib/nlattr.c b/lib/nlattr.c
index a0c80fbf71895..dffd60e4065fd 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -125,10 +125,12 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
range->max = U8_MAX;
break;
case NLA_U16:
+ case NLA_BE16:
case NLA_BINARY:
range->max = U16_MAX;
break;
case NLA_U32:
+ case NLA_BE32:
range->max = U32_MAX;
break;
case NLA_U64:
@@ -160,31 +162,6 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
}
}

-static u64 nla_get_attr_bo(const struct nla_policy *pt,
- const struct nlattr *nla)
-{
- switch (pt->type) {
- case NLA_U16:
- if (pt->network_byte_order)
- return ntohs(nla_get_be16(nla));
-
- return nla_get_u16(nla);
- case NLA_U32:
- if (pt->network_byte_order)
- return ntohl(nla_get_be32(nla));
-
- return nla_get_u32(nla);
- case NLA_U64:
- if (pt->network_byte_order)
- return be64_to_cpu(nla_get_be64(nla));
-
- return nla_get_u64(nla);
- }
-
- WARN_ON_ONCE(1);
- return 0;
-}
-
static int nla_validate_range_unsigned(const struct nla_policy *pt,
const struct nlattr *nla,
struct netlink_ext_ack *extack,
@@ -198,9 +175,13 @@ static int nla_validate_range_unsigned(const struct nla_policy *pt,
value = nla_get_u8(nla);
break;
case NLA_U16:
+ value = nla_get_u16(nla);
+ break;
case NLA_U32:
+ value = nla_get_u32(nla);
+ break;
case NLA_U64:
- value = nla_get_attr_bo(pt, nla);
+ value = nla_get_u64(nla);
break;
case NLA_MSECS:
value = nla_get_u64(nla);
@@ -208,6 +189,12 @@ static int nla_validate_range_unsigned(const struct nla_policy *pt,
case NLA_BINARY:
value = nla_len(nla);
break;
+ case NLA_BE16:
+ value = ntohs(nla_get_be16(nla));
+ break;
+ case NLA_BE32:
+ value = ntohl(nla_get_be32(nla));
+ break;
default:
return -EINVAL;
}
@@ -335,6 +322,8 @@ static int nla_validate_int_range(const struct nla_policy *pt,
case NLA_U64:
case NLA_MSECS:
case NLA_BINARY:
+ case NLA_BE16:
+ case NLA_BE32:
return nla_validate_range_unsigned(pt, nla, extack, validate);
case NLA_S8:
case NLA_S16:
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index cb6ee00bbc09b..dbafb964bd706 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -176,10 +176,10 @@ static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
[NFTA_PAYLOAD_SREG] = { .type = NLA_U32 },
[NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
[NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
- [NFTA_PAYLOAD_OFFSET] = NLA_POLICY_MAX_BE(NLA_U32, 255),
- [NFTA_PAYLOAD_LEN] = NLA_POLICY_MAX_BE(NLA_U32, 255),
+ [NFTA_PAYLOAD_OFFSET] = NLA_POLICY_MAX(NLA_BE32, 255),
+ [NFTA_PAYLOAD_LEN] = NLA_POLICY_MAX(NLA_BE32, 255),
[NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 },
- [NFTA_PAYLOAD_CSUM_OFFSET] = NLA_POLICY_MAX_BE(NLA_U32, 255),
+ [NFTA_PAYLOAD_CSUM_OFFSET] = NLA_POLICY_MAX(NLA_BE32, 255),
[NFTA_PAYLOAD_CSUM_FLAGS] = { .type = NLA_U32 },
};

--
2.51.0