netfilter: nf_tables: remove register tracking infrastructure

This facility was disabled in commit
9e539c5b6d9c ("netfilter: nf_tables: disable expression reduction infra"),
because not all nft_exprs guarantee they will update the destination
register: some may set NFT_BREAK instead to cancel evaluation of the
rule.

This has been dead code ever since.
There are no plans to salvage this at this time, so remove this.

Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260224205048.4718-10-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 0 insertions, 37 deletions

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 426534a711b0..40e8106e71f0 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -122,17 +122,6 @@ struct nft_regs {
 	};
 };
 
-struct nft_regs_track {
-	struct {
-		const struct nft_expr		*selector;
-		const struct nft_expr		*bitwise;
-		u8				num_reg;
-	} regs[NFT_REG32_NUM];
-
-	const struct nft_expr			*cur;
-	const struct nft_expr			*last;
-};
-
 /* Store/load an u8, u16 or u64 integer to/from the u32 data register.
  *
  * Note, when using concatenations, register allocation happens at 32-bit
@@ -427,8 +416,6 @@ int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src, gfp_t gfp);
 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 		  const struct nft_expr *expr, bool reset);
-bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
-			     const struct nft_expr *expr);
 
 struct nft_set_ext;
 
@@ -941,7 +928,6 @@ struct nft_offload_ctx;
  *	@destroy_clone: destruction clone function
  *	@dump: function to dump parameters
  *	@validate: validate expression, called during loop detection
- *	@reduce: reduce expression
  *	@gc: garbage collection expression
  *	@offload: hardware offload expression
  *	@offload_action: function to report true/false to allocate one slot or not in the flow
@@ -975,8 +961,6 @@ struct nft_expr_ops {
 						bool reset);
 	int				(*validate)(const struct nft_ctx *ctx,
 						    const struct nft_expr *expr);
-	bool				(*reduce)(struct nft_regs_track *track,
-						  const struct nft_expr *expr);
 	bool				(*gc)(struct net *net,
 					      const struct nft_expr *expr);
 	int				(*offload)(struct nft_offload_ctx *ctx,
@@ -1954,20 +1938,4 @@ static inline u64 nft_net_tstamp(const struct net *net)
 	return nft_pernet(net)->tstamp;
 }
 
-#define __NFT_REDUCE_READONLY	1UL
-#define NFT_REDUCE_READONLY	(void *)__NFT_REDUCE_READONLY
-
-void nft_reg_track_update(struct nft_regs_track *track,
-			  const struct nft_expr *expr, u8 dreg, u8 len);
-void nft_reg_track_cancel(struct nft_regs_track *track, u8 dreg, u8 len);
-void __nft_reg_track_cancel(struct nft_regs_track *track, u8 dreg);
-
-static inline bool nft_reg_track_cmp(struct nft_regs_track *track,
-				     const struct nft_expr *expr, u8 dreg)
-{
-	return track->regs[dreg].selector &&
-	       track->regs[dreg].selector->ops == expr->ops &&
-	       track->regs[dreg].num_reg == 0;
-}
-
 #endif /* _NET_NF_TABLES_H */
diff --git a/include/net/netfilter/nft_fib.h b/include/net/netfilter/nft_fib.h
index 7370fba844ef..e0422456f27b 100644
--- a/include/net/netfilter/nft_fib.h
+++ b/include/net/netfilter/nft_fib.h
@@ -66,6 +66,4 @@ void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
 void nft_fib_store_result(void *reg, const struct nft_fib *priv,
 			  const struct net_device *dev);
 
-bool nft_fib_reduce(struct nft_regs_track *track,
-		    const struct nft_expr *expr);
 #endif
diff --git a/include/net/netfilter/nft_meta.h b/include/net/netfilter/nft_meta.h
index d602263590fe..f74e63290603 100644
--- a/include/net/netfilter/nft_meta.h
+++ b/include/net/netfilter/nft_meta.h
@@ -43,9 +43,6 @@ void nft_meta_set_destroy(const struct nft_ctx *ctx,
 int nft_meta_set_validate(const struct nft_ctx *ctx,
 			  const struct nft_expr *expr);
 
-bool nft_meta_get_reduce(struct nft_regs_track *track,
-			 const struct nft_expr *expr);
-
 struct nft_inner_tun_ctx;
 void nft_meta_inner_eval(const struct nft_expr *expr,
 			 struct nft_regs *regs, const struct nft_pktinfo *pkt,