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netfilter: nf_tables: add direct calls for all builtin expressions 

With CONFIG_RETPOLINE its faster to add an if (ptr == &foo_func)
check and and use direct calls for all the built-in expressions.

~15% improvement in pathological cases.

checkpatch doesn't like the X macro due to the embedded return statement,
but the macro has a very limited scope so I don't think its a problem.

I would like to avoid bugs of the form
  If (e->ops->eval == (unsigned long)nft_foo_eval)
	 nft_bar_eval();

and open-coded if ()/else if()/else cascade, thus the macro.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2019-01-08 17:35:34 +01:00 committed by Pablo Neira Ayuso
parent 4d44175aa5
commit 10870dd89e
10 changed files with 54 additions and 30 deletions
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16
include/net/netfilter/nf_tables_core.h
View File

@ -80,6 +80,22 @@ struct nft_regs;
struct nft_pktinfo;
void nft_meta_get_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_cmp_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_lookup_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_payload_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_immediate_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_range_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_byteorder_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_dynset_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_rt_get_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
#endif /* _NET_NF_TABLES_CORE_H */

23
net/netfilter/nf_tables_core.c
View File

@ -124,14 +124,25 @@ static void expr_call_ops_eval(const struct nft_expr *expr,
struct nft_regs *regs,
struct nft_pktinfo *pkt)
{
#ifdef CONFIG_RETPOLINE
unsigned long e = (unsigned long)expr->ops->eval;
#define X(e, fun) \
do { if ((e) == (unsigned long)(fun)) \
return fun(expr, regs, pkt); } while (0)
if (e == (unsigned long)nft_meta_get_eval)
nft_meta_get_eval(expr, regs, pkt);
else if (e == (unsigned long)nft_lookup_eval)
nft_lookup_eval(expr, regs, pkt);
else
expr->ops->eval(expr, regs, pkt);
X(e, nft_payload_eval);
X(e, nft_cmp_eval);
X(e, nft_meta_get_eval);
X(e, nft_lookup_eval);
X(e, nft_range_eval);
X(e, nft_immediate_eval);
X(e, nft_byteorder_eval);
X(e, nft_dynset_eval);
X(e, nft_rt_get_eval);
X(e, nft_bitwise_eval);
#undef X
#endif /* CONFIG_RETPOLINE */
expr->ops->eval(expr, regs, pkt);
}
unsigned int

5
net/netfilter/nft_bitwise.c
View File

@ -25,9 +25,8 @@ struct nft_bitwise {
struct nft_data xor;
};
static void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
const u32 *src = &regs->data[priv->sreg];

6
net/netfilter/nft_byteorder.c
View File

@ -26,9 +26,9 @@ struct nft_byteorder {
u8 size;
};
static void nft_byteorder_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_byteorder_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_byteorder *priv = nft_expr_priv(expr);
u32 *src = &regs->data[priv->sreg];

6
net/netfilter/nft_cmp.c
View File

@ -24,9 +24,9 @@ struct nft_cmp_expr {
enum nft_cmp_ops op:8;
};
static void nft_cmp_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_cmp_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_cmp_expr *priv = nft_expr_priv(expr);
int d;

5
net/netfilter/nft_dynset.c
View File

@ -62,9 +62,8 @@ err1:
return NULL;
}
static void nft_dynset_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_dynset_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
const struct nft_dynset *priv = nft_expr_priv(expr);
struct nft_set *set = priv->set;

6
net/netfilter/nft_immediate.c
View File

@ -17,9 +17,9 @@
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
static void nft_immediate_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_immediate_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_immediate_expr *priv = nft_expr_priv(expr);

6
net/netfilter/nft_payload.c
View File

@ -70,9 +70,9 @@ nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
}
static void nft_payload_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_payload_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_payload *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;

5
net/netfilter/nft_range.c
View File

@ -23,9 +23,8 @@ struct nft_range_expr {
enum nft_range_ops op:8;
};
static void nft_range_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_range_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
const struct nft_range_expr *priv = nft_expr_priv(expr);
int d1, d2;

6
net/netfilter/nft_rt.c
View File

@ -53,9 +53,9 @@ static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skb
return mtu - minlen;
}
static void nft_rt_get_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
void nft_rt_get_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_rt *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;