netfilter: nft_meta: split nft_meta_init() into two functions for get/set

For value spanning multiple registers, we need to validate the length
of data loads. In order to add this to nft_meta, we need the length from
key validation. Split the nft_meta_init() function into two functions
for the get and set operations as preparation for that.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>

diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 425cf39af8907f1d0618b0904121073ea4dc116a..6d0b8cc27f2af3a68bca055b7bc23181234ad8ca 100644 (file)
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -170,21 +170,15 @@ static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
        [NFTA_META_SREG]        = { .type = NLA_U32 },
 };
 
-static int nft_meta_init_validate_set(uint32_t key)
+static int nft_meta_get_init(const struct nft_ctx *ctx,
+                            const struct nft_expr *expr,
+                            const struct nlattr * const tb[])
 {
-       switch (key) {
-       case NFT_META_MARK:
-       case NFT_META_PRIORITY:
-       case NFT_META_NFTRACE:
-               return 0;
-       default:
-               return -EOPNOTSUPP;
-       }
-}
+       struct nft_meta *priv = nft_expr_priv(expr);
+       int err;
 
-static int nft_meta_init_validate_get(uint32_t key)
-{
-       switch (key) {
+       priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
+       switch (priv->key) {
        case NFT_META_LEN:
        case NFT_META_PROTOCOL:
        case NFT_META_NFPROTO:
@@ -205,39 +199,40 @@ static int nft_meta_init_validate_get(uint32_t key)
 #ifdef CONFIG_NETWORK_SECMARK
        case NFT_META_SECMARK:
 #endif
-               return 0;
+               break;
        default:
                return -EOPNOTSUPP;
        }
 
+       priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG]));
+       err = nft_validate_output_register(priv->dreg);
+       if (err < 0)
+               return err;
+
+       err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
+       if (err < 0)
+               return err;
+
+       return 0;
 }
 
-static int nft_meta_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
-                        const struct nlattr * const tb[])
+static int nft_meta_set_init(const struct nft_ctx *ctx,
+                            const struct nft_expr *expr,
+                            const struct nlattr * const tb[])
 {
        struct nft_meta *priv = nft_expr_priv(expr);
        int err;
 
        priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
-
-       if (tb[NFTA_META_DREG]) {
-               err = nft_meta_init_validate_get(priv->key);
-               if (err < 0)
-                       return err;
-
-               priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG]));
-               err = nft_validate_output_register(priv->dreg);
-               if (err < 0)
-                       return err;
-
-               return nft_validate_data_load(ctx, priv->dreg, NULL,
-                                             NFT_DATA_VALUE);
+       switch (priv->key) {
+       case NFT_META_MARK:
+       case NFT_META_PRIORITY:
+       case NFT_META_NFTRACE:
+               break;
+       default:
+               return -EOPNOTSUPP;
        }
 
-       err = nft_meta_init_validate_set(priv->key);
-       if (err < 0)
-               return err;
-
        priv->sreg = ntohl(nla_get_be32(tb[NFTA_META_SREG]));
        err = nft_validate_input_register(priv->sreg);
        if (err < 0)
@@ -282,7 +277,7 @@ static const struct nft_expr_ops nft_meta_get_ops = {
        .type           = &nft_meta_type,
        .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
        .eval           = nft_meta_get_eval,
-       .init           = nft_meta_init,
+       .init           = nft_meta_get_init,
        .dump           = nft_meta_get_dump,
 };
 
@@ -290,7 +285,7 @@ static const struct nft_expr_ops nft_meta_set_ops = {
        .type           = &nft_meta_type,
        .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
        .eval           = nft_meta_set_eval,
-       .init           = nft_meta_init,
+       .init           = nft_meta_set_init,
        .dump           = nft_meta_set_dump,
 };