netfilter: bitwise: add helper for initializing boolean operations.

Split the code specific to initializing bitwise boolean operations out
into a separate function.  A similar function will be added later for
shift operations.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Jeremy Sowden 2020-01-15 20:05:52 +00:00 committed by Pablo Neira Ayuso
parent 9d1f979986
commit 3f8d9eb032

View File

@ -45,20 +45,53 @@ static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
[NFTA_BITWISE_OP] = { .type = NLA_U32 },
};
static int nft_bitwise_init_bool(struct nft_bitwise *priv,
const struct nlattr *const tb[])
{
struct nft_data_desc d1, d2;
int err;
if (!tb[NFTA_BITWISE_MASK] ||
!tb[NFTA_BITWISE_XOR])
return -EINVAL;
err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
if (d1.type != NFT_DATA_VALUE || d1.len != priv->len) {
err = -EINVAL;
goto err1;
}
err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
tb[NFTA_BITWISE_XOR]);
if (err < 0)
goto err1;
if (d2.type != NFT_DATA_VALUE || d2.len != priv->len) {
err = -EINVAL;
goto err2;
}
return 0;
err2:
nft_data_release(&priv->xor, d2.type);
err1:
nft_data_release(&priv->mask, d1.type);
return err;
}
static int nft_bitwise_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_bitwise *priv = nft_expr_priv(expr);
struct nft_data_desc d1, d2;
u32 len;
int err;
if (!tb[NFTA_BITWISE_SREG] ||
!tb[NFTA_BITWISE_DREG] ||
!tb[NFTA_BITWISE_LEN] ||
!tb[NFTA_BITWISE_MASK] ||
!tb[NFTA_BITWISE_XOR])
!tb[NFTA_BITWISE_LEN])
return -EINVAL;
err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
@ -90,29 +123,12 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
priv->op = NFT_BITWISE_BOOL;
}
err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
if (d1.type != NFT_DATA_VALUE || d1.len != priv->len) {
err = -EINVAL;
goto err1;
switch(priv->op) {
case NFT_BITWISE_BOOL:
err = nft_bitwise_init_bool(priv, tb);
break;
}
err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
tb[NFTA_BITWISE_XOR]);
if (err < 0)
goto err1;
if (d2.type != NFT_DATA_VALUE || d2.len != priv->len) {
err = -EINVAL;
goto err2;
}
return 0;
err2:
nft_data_release(&priv->xor, d2.type);
err1:
nft_data_release(&priv->mask, d1.type);
return err;
}