From cb7dbfd0390c9e244339f3270fe8649568241812 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 10 Oct 2013 23:35:40 +0200 Subject: [PATCH] netfilter: nf_tables: add optimized data comparison for small values 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 Signed-off-by: Pablo Neira Ayuso --- 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 283396c916e0..3df6a9be3bdd 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 fd0ecd3255c1..24000182c8e7 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -20,6 +20,18 @@ #include #include +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 2c9d5fef2e63..37134f3e84fb 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, -- 2.20.1