From: Patrick McHardy <kaber@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
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 3df6a9b..fe7b162 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 2400018..9aede59 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 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 @@ 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,
--
1.7.10.4
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