From: Patrick McHardy <kaber@xxxxxxxxx>
Add an optimized version of nft_data_cmp() that only handles values of to
4 bytes length.
This patch includes original Patrick McHardy's patch entitled (nf_tables:
inline nft_cmp_fast_eval() into main evaluation loop).
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_tables_core.h | 8 +++
net/netfilter/nf_tables_core.c | 18 ++++-
net/netfilter/nft_cmp.c | 116 +++++++++++++++++++++++++-------
3 files changed, 118 insertions(+), 24 deletions(-)
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h
index 283396c..3df6a9b 100644
--- a/include/net/netfilter/nf_tables_core.h
+++ b/include/net/netfilter/nf_tables_core.h
@@ -7,6 +7,14 @@ extern void nf_tables_core_module_exit(void);
extern int nft_immediate_module_init(void);
extern void nft_immediate_module_exit(void);
+struct nft_cmp_fast_expr {
+ u32 data;
+ enum nft_registers sreg:8;
+ u8 len;
+};
+
+extern const struct nft_expr_ops nft_cmp_fast_ops;
+
extern int nft_cmp_module_init(void);
extern void nft_cmp_module_exit(void);
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index fd0ecd3..2400018 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -20,6 +20,18 @@
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
+static void nft_cmp_fast_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1])
+{
+ const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+ u32 mask;
+
+ mask = ~0U >> (sizeof(priv->data) * BITS_PER_BYTE - priv->len);
+ if ((data[priv->sreg].data[0] & mask) == priv->data)
+ return;
+ data[NFT_REG_VERDICT].verdict = NFT_BREAK;
+}
+
unsigned int nft_do_chain(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
@@ -48,7 +60,11 @@ next_rule:
data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
list_for_each_entry_continue_rcu(rule, &chain->rules, list) {
nft_rule_for_each_expr(expr, last, rule) {
- expr->ops->eval(expr, data, &pkt);
+ if (expr->ops == &nft_cmp_fast_ops)
+ nft_cmp_fast_eval(expr, data);
+ else
+ expr->ops->eval(expr, data, &pkt);
+
if (data[NFT_REG_VERDICT].verdict != NFT_CONTINUE)
break;
}
diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index 2c9d5fe..37134f3 100644
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -75,32 +75,11 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
struct nft_data_desc desc;
int err;
- if (tb[NFTA_CMP_SREG] == NULL ||
- tb[NFTA_CMP_OP] == NULL ||
- tb[NFTA_CMP_DATA] == NULL)
- return -EINVAL;
-
priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
- err = nft_validate_input_register(priv->sreg);
- if (err < 0)
- return err;
-
priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
- switch (priv->op) {
- case NFT_CMP_EQ:
- case NFT_CMP_NEQ:
- case NFT_CMP_LT:
- case NFT_CMP_LTE:
- case NFT_CMP_GT:
- case NFT_CMP_GTE:
- break;
- default:
- return -EINVAL;
- }
err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);
- if (err < 0)
- return err;
+ BUG_ON(err < 0);
priv->len = desc.len;
return 0;
@@ -133,9 +112,100 @@ static const struct nft_expr_ops nft_cmp_ops = {
.dump = nft_cmp_dump,
};
+static int nft_cmp_fast_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_data_desc desc;
+ struct nft_data data;
+ u32 mask;
+ int err;
+
+ priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
+
+ err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
+ BUG_ON(err < 0);
+ desc.len *= BITS_PER_BYTE;
+
+ mask = ~0U >> (sizeof(priv->data) * BITS_PER_BYTE - desc.len);
+ priv->data = data.data[0] & mask;
+ priv->len = desc.len;
+ return 0;
+}
+
+static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_data data;
+
+ if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
+ goto nla_put_failure;
+
+ data.data[0] = priv->data;
+ if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
+ NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+const struct nft_expr_ops nft_cmp_fast_ops = {
+ .type = &nft_cmp_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
+ .eval = NULL, /* inlined */
+ .init = nft_cmp_fast_init,
+ .dump = nft_cmp_fast_dump,
+};
+
+static const struct nft_expr_ops *nft_cmp_select_ops(const struct nlattr * const tb[])
+{
+ struct nft_data_desc desc;
+ struct nft_data data;
+ enum nft_registers sreg;
+ enum nft_cmp_ops op;
+ int err;
+
+ if (tb[NFTA_CMP_SREG] == NULL ||
+ tb[NFTA_CMP_OP] == NULL ||
+ tb[NFTA_CMP_DATA] == NULL)
+ return ERR_PTR(-EINVAL);
+
+ sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
+ err = nft_validate_input_register(sreg);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
+ switch (op) {
+ case NFT_CMP_EQ:
+ case NFT_CMP_NEQ:
+ case NFT_CMP_LT:
+ case NFT_CMP_LTE:
+ case NFT_CMP_GT:
+ case NFT_CMP_GTE:
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
+ return &nft_cmp_fast_ops;
+ else
+ return &nft_cmp_ops;
+}
+
static struct nft_expr_type nft_cmp_type __read_mostly = {
.name = "cmp",
- .ops = &nft_cmp_ops,
+ .select_ops = nft_cmp_select_ops,
.policy = nft_cmp_policy,
.maxattr = NFTA_CMP_MAX,
.owner = THIS_MODULE,
--
1.7.10.4
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