netlink: introduce bigendian integer types

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>

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 7db13b3..6bfa972 100644 (file)
--- 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 40f22b1..b67a53e 100644 (file)
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -124,10 +124,12 @@ 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:
@@ -159,31 +161,6 @@ 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,
@@ -197,9 +174,13 @@ 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);
@@ -207,6 +188,12 @@ 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;
        }
@@ -334,6 +321,8 @@ 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 088244f..4edd899 100644 (file)
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -173,10 +173,10 @@ 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 },
 };