From c29b72e02573b8fe5e6cae5d192a6a4772e7bbd6 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 10 Oct 2013 11:06:41 +0200 Subject: [PATCH] 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 Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables_core.h | 9 ++++ net/netfilter/nf_tables_core.c | 31 +++++++++++- net/netfilter/nft_payload.c | 69 ++++++++++++++++---------- 3 files changed, 81 insertions(+), 28 deletions(-) diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h index 3df6a9be3bdd..fe7b16206a4e 100644 --- a/include/net/netfilter/nf_tables_core.h +++ b/include/net/netfilter/nf_tables_core.h @@ -27,6 +27,15 @@ extern void nft_bitwise_module_exit(void); extern int nft_byteorder_module_init(void); extern void nft_byteorder_module_exit(void); +struct nft_payload { + enum nft_payload_bases base:8; + u8 offset; + u8 len; + enum nft_registers dreg:8; +}; + +extern const struct nft_expr_ops nft_payload_fast_ops; + extern int nft_payload_module_init(void); extern void nft_payload_module_exit(void); diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 24000182c8e7..9aede59ed2d7 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -32,6 +32,34 @@ static void nft_cmp_fast_eval(const struct nft_expr *expr, data[NFT_REG_VERDICT].verdict = NFT_BREAK; } +static bool nft_payload_fast_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_payload *priv = nft_expr_priv(expr); + const struct sk_buff *skb = pkt->skb; + struct nft_data *dest = &data[priv->dreg]; + unsigned char *ptr; + + if (priv->base == NFT_PAYLOAD_NETWORK_HEADER) + ptr = skb_network_header(skb); + else + ptr = skb_transport_header(skb); + + ptr += priv->offset; + + if (unlikely(ptr + priv->len >= skb_tail_pointer(skb))) + return false; + + if (priv->len == 2) + *(u16 *)dest->data = *(u16 *)ptr; + else if (priv->len == 4) + *(u32 *)dest->data = *(u32 *)ptr; + else + *(u8 *)dest->data = *(u8 *)ptr; + return true; +} + unsigned int nft_do_chain(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct net_device *in, @@ -62,7 +90,8 @@ next_rule: nft_rule_for_each_expr(expr, last, rule) { if (expr->ops == &nft_cmp_fast_ops) nft_cmp_fast_eval(expr, data); - else + else if (expr->ops != &nft_payload_fast_ops || + !nft_payload_fast_eval(expr, data, &pkt)) expr->ops->eval(expr, data, &pkt); if (data[NFT_REG_VERDICT].verdict != NFT_CONTINUE) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index d99db6e37fb1..7cf13f7e1e94 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -17,13 +17,6 @@ #include #include -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 @@ static int nft_payload_init(const struct nft_ctx *ctx, 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 @@ static const struct nft_expr_ops nft_payload_ops = { .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,