netfilter: nft_payload: add optimized payload implementation for small loads
Add an optimized payload expression implementation for small (up to 4 bytes)
aligned data loads from the linear packet area.
This patch also includes original Patrick McHardy's entitled (nf_tables:
inline nft_payload_fast_eval() into main evaluation loop).
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index d99db6e..7cf13f7 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -17,13 +17,6 @@
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
-struct nft_payload {
- enum nft_payload_bases base:8;
- u8 offset;
- u8 len;
- enum nft_registers dreg:8;
-};
-
static void nft_payload_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
@@ -71,27 +64,9 @@
struct nft_payload *priv = nft_expr_priv(expr);
int err;
- if (tb[NFTA_PAYLOAD_DREG] == NULL ||
- tb[NFTA_PAYLOAD_BASE] == NULL ||
- tb[NFTA_PAYLOAD_OFFSET] == NULL ||
- tb[NFTA_PAYLOAD_LEN] == NULL)
- return -EINVAL;
-
- priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
- switch (priv->base) {
- case NFT_PAYLOAD_LL_HEADER:
- case NFT_PAYLOAD_NETWORK_HEADER:
- case NFT_PAYLOAD_TRANSPORT_HEADER:
- break;
- default:
- return -EOPNOTSUPP;
- }
-
+ priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
- if (priv->len == 0 ||
- priv->len > FIELD_SIZEOF(struct nft_data, data))
- return -EINVAL;
priv->dreg = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_DREG]));
err = nft_validate_output_register(priv->dreg);
@@ -124,9 +99,49 @@
.dump = nft_payload_dump,
};
+const struct nft_expr_ops nft_payload_fast_ops = {
+ .type = &nft_payload_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
+ .eval = nft_payload_eval,
+ .init = nft_payload_init,
+ .dump = nft_payload_dump,
+};
+
+static const struct nft_expr_ops *nft_payload_select_ops(const struct nlattr * const tb[])
+{
+ enum nft_payload_bases base;
+ unsigned int offset, len;
+
+ if (tb[NFTA_PAYLOAD_DREG] == NULL ||
+ tb[NFTA_PAYLOAD_BASE] == NULL ||
+ tb[NFTA_PAYLOAD_OFFSET] == NULL ||
+ tb[NFTA_PAYLOAD_LEN] == NULL)
+ return ERR_PTR(-EINVAL);
+
+ base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
+ switch (base) {
+ case NFT_PAYLOAD_LL_HEADER:
+ case NFT_PAYLOAD_NETWORK_HEADER:
+ case NFT_PAYLOAD_TRANSPORT_HEADER:
+ break;
+ default:
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+
+ offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
+ len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
+ if (len == 0 || len > FIELD_SIZEOF(struct nft_data, data))
+ return ERR_PTR(-EINVAL);
+
+ if (len <= 4 && IS_ALIGNED(offset, len) && base != NFT_PAYLOAD_LL_HEADER)
+ return &nft_payload_fast_ops;
+ else
+ return &nft_payload_ops;
+}
+
static struct nft_expr_type nft_payload_type __read_mostly = {
.name = "payload",
- .ops = &nft_payload_ops,
+ .select_ops = nft_payload_select_ops,
.policy = nft_payload_policy,
.maxattr = NFTA_PAYLOAD_MAX,
.owner = THIS_MODULE,