netfilter: bitwise: add NFTA_BITWISE_OP netlink attribute.

Add a new bitwise netlink attribute, NFTA_BITWISE_OP, which is set to a
value of a new enum, nft_bitwise_ops.  It describes the type of
operation an expression contains.  Currently, it only has one value:
NFT_BITWISE_BOOL.  More values will be added later to implement shifts.

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 20:05:51 +00:00 committed by Pablo Neira Ayuso
parent 577c734a81
commit 9d1f979986
2 changed files with 28 additions and 0 deletions

View File

@ -484,6 +484,16 @@ enum nft_immediate_attributes {
};
#define NFTA_IMMEDIATE_MAX (__NFTA_IMMEDIATE_MAX - 1)
/**
* enum nft_bitwise_ops - nf_tables bitwise operations
*
* @NFT_BITWISE_BOOL: mask-and-xor operation used to implement NOT, AND, OR and
* XOR boolean operations
*/
enum nft_bitwise_ops {
NFT_BITWISE_BOOL,
};
/**
* enum nft_bitwise_attributes - nf_tables bitwise expression netlink attributes
*
@ -492,6 +502,7 @@ enum nft_immediate_attributes {
* @NFTA_BITWISE_LEN: length of operands (NLA_U32)
* @NFTA_BITWISE_MASK: mask value (NLA_NESTED: nft_data_attributes)
* @NFTA_BITWISE_XOR: xor value (NLA_NESTED: nft_data_attributes)
* @NFTA_BITWISE_OP: type of operation (NLA_U32: nft_bitwise_ops)
*
* The bitwise expression performs the following operation:
*
@ -512,6 +523,7 @@ enum nft_bitwise_attributes {
NFTA_BITWISE_LEN,
NFTA_BITWISE_MASK,
NFTA_BITWISE_XOR,
NFTA_BITWISE_OP,
__NFTA_BITWISE_MAX
};
#define NFTA_BITWISE_MAX (__NFTA_BITWISE_MAX - 1)

View File

@ -18,6 +18,7 @@
struct nft_bitwise {
enum nft_registers sreg:8;
enum nft_registers dreg:8;
enum nft_bitwise_ops op:8;
u8 len;
struct nft_data mask;
struct nft_data xor;
@ -41,6 +42,7 @@ static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
[NFTA_BITWISE_LEN] = { .type = NLA_U32 },
[NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
[NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
[NFTA_BITWISE_OP] = { .type = NLA_U32 },
};
static int nft_bitwise_init(const struct nft_ctx *ctx,
@ -76,6 +78,18 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
if (err < 0)
return err;
if (tb[NFTA_BITWISE_OP]) {
priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
switch (priv->op) {
case NFT_BITWISE_BOOL:
break;
default:
return -EOPNOTSUPP;
}
} else {
priv->op = NFT_BITWISE_BOOL;
}
err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
@ -112,6 +126,8 @@ static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op)))
return -1;
if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
NFT_DATA_VALUE, priv->len) < 0)