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Commit 10870dd8 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
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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: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 4d44175a

include/net/netfilter/nf_tables_core.h

+16 −0
Original line number Diff line number Diff line
@@ -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 */

net/netfilter/nf_tables_core.c

+18 −7
Original line number Diff line number Diff line
@@ -124,13 +124,24 @@ 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;



	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

#define X(e, fun) \

	do { if ((e) == (unsigned long)(fun)) \

		return fun(expr, regs, pkt); } while (0)



	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);

}

net/netfilter/nft_bitwise.c

+2 −3
Original line number Diff line number Diff line
@@ -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];

net/netfilter/nft_byteorder.c

+3 −3
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ struct nft_byteorder { 
	u8			size;

};



static void nft_byteorder_eval(const struct nft_expr *expr,

void nft_byteorder_eval(const struct nft_expr *expr,

			struct nft_regs *regs,

			const struct nft_pktinfo *pkt)

{

net/netfilter/nft_cmp.c

+3 −3
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ struct nft_cmp_expr { 
	enum nft_cmp_ops	op:8;

};



static void nft_cmp_eval(const struct nft_expr *expr,

void nft_cmp_eval(const struct nft_expr *expr,

		  struct nft_regs *regs,

		  const struct nft_pktinfo *pkt)

{