netfilter: nf_tables: restore context for expression destructors

In order to fix set destruction notifications and get rid of unnecessary
members in private data structures, pass the context to expressions'
destructor functions again.

In order to do so, replace various members in the nft_rule_trans structure
by the full context.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables.h

@@ -289,7 +289,8 @@ struct nft_expr_ops {
 	int				(*init)(const struct nft_ctx *ctx,
 						const struct nft_expr *expr,
 						const struct nlattr * const tb[]);
-	void				(*destroy)(const struct nft_expr *expr);
+	void				(*destroy)(const struct nft_ctx *ctx,
+						   const struct nft_expr *expr);
 	int				(*dump)(struct sk_buff *skb,
 						const struct nft_expr *expr);
 	int				(*validate)(const struct nft_ctx *ctx,
@@ -343,19 +344,13 @@ struct nft_rule {
  *	struct nft_rule_trans - nf_tables rule update in transaction
  *
  *	@list: used internally
+ *	@ctx: rule context
  *	@rule: rule that needs to be updated
- *	@chain: chain that this rule belongs to
- *	@table: table for which this chain applies
- *	@nlh: netlink header of the message that contain this update
- *	@family: family expressesed as AF_*
  */
 struct nft_rule_trans {
 	struct list_head		list;
+	struct nft_ctx			ctx;
 	struct nft_rule			*rule;
-	const struct nft_chain		*chain;
-	const struct nft_table		*table;
-	const struct nlmsghdr		*nlh;
-	u8				family;
 };
 
 static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)

net/netfilter/nf_tables_api.c

@@ -1253,10 +1253,11 @@ err1:
 	return err;
 }
 
-static void nf_tables_expr_destroy(struct nft_expr *expr)
+static void nf_tables_expr_destroy(const struct nft_ctx *ctx,
+				   struct nft_expr *expr)
 {
 	if (expr->ops->destroy)
-		expr->ops->destroy(expr);
+		expr->ops->destroy(ctx, expr);
 	module_put(expr->ops->type->owner);
 }
 
@@ -1536,7 +1537,8 @@ err:
 	return err;
 }
 
-static void nf_tables_rule_destroy(struct nft_rule *rule)
+static void nf_tables_rule_destroy(const struct nft_ctx *ctx,
+				   struct nft_rule *rule)
 {
 	struct nft_expr *expr;
 
@@ -1546,7 +1548,7 @@ static void nf_tables_rule_destroy(struct nft_rule *rule)
 	 */
 	expr = nft_expr_first(rule);
 	while (expr->ops && expr != nft_expr_last(rule)) {
-		nf_tables_expr_destroy(expr);
+		nf_tables_expr_destroy(ctx, expr);
 		expr = nft_expr_next(expr);
 	}
 	kfree(rule);
@@ -1565,11 +1567,8 @@ nf_tables_trans_add(struct nft_ctx *ctx, struct nft_rule *rule)
 	if (rupd == NULL)
 	       return NULL;
 
-	rupd->chain = ctx->chain;
-	rupd->table = ctx->table;
+	rupd->ctx = *ctx;
 	rupd->rule = rule;
-	rupd->family = ctx->afi->family;
-	rupd->nlh = ctx->nlh;
 	list_add_tail(&rupd->list, &ctx->net->nft.commit_list);
 
 	return rupd;
@@ -1721,7 +1720,7 @@ err3:
 		kfree(repl);
 	}
 err2:
-	nf_tables_rule_destroy(rule);
+	nf_tables_rule_destroy(&ctx, rule);
 err1:
 	for (i = 0; i < n; i++) {
 		if (info[i].ops != NULL)
@@ -1831,10 +1830,10 @@ static int nf_tables_commit(struct sk_buff *skb)
 		 */
 		if (nft_rule_is_active(net, rupd->rule)) {
 			nft_rule_clear(net, rupd->rule);
-			nf_tables_rule_notify(skb, rupd->nlh, rupd->table,
-					      rupd->chain, rupd->rule,
-					      NFT_MSG_NEWRULE, 0,
-					      rupd->family);
+			nf_tables_rule_notify(skb, rupd->ctx.nlh,
+					      rupd->ctx.table, rupd->ctx.chain,
+					      rupd->rule, NFT_MSG_NEWRULE, 0,
+					      rupd->ctx.afi->family);
 			list_del(&rupd->list);
 			kfree(rupd);
 			continue;
@@ -1842,9 +1841,10 @@ static int nf_tables_commit(struct sk_buff *skb)
 
 		/* This rule is in the past, get rid of it */
 		list_del_rcu(&rupd->rule->list);
-		nf_tables_rule_notify(skb, rupd->nlh, rupd->table, rupd->chain,
+		nf_tables_rule_notify(skb, rupd->ctx.nlh,
+				      rupd->ctx.table, rupd->ctx.chain,
 				      rupd->rule, NFT_MSG_DELRULE, 0,
-				      rupd->family);
+				      rupd->ctx.afi->family);
 	}
 
 	/* Make sure we don't see any packet traversing old rules */
@@ -1852,7 +1852,7 @@ static int nf_tables_commit(struct sk_buff *skb)
 
 	/* Now we can safely release unused old rules */
 	list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
-		nf_tables_rule_destroy(rupd->rule);
+		nf_tables_rule_destroy(&rupd->ctx, rupd->rule);
 		list_del(&rupd->list);
 		kfree(rupd);
 	}
@@ -1881,7 +1881,7 @@ static int nf_tables_abort(struct sk_buff *skb)
 	synchronize_rcu();
 
 	list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
-		nf_tables_rule_destroy(rupd->rule);
+		nf_tables_rule_destroy(&rupd->ctx, rupd->rule);
 		list_del(&rupd->list);
 		kfree(rupd);
 	}

net/netfilter/nft_compat.c

@@ -192,7 +192,7 @@ err:
 }
 
 static void
-nft_target_destroy(const struct nft_expr *expr)
+nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
 {
 	struct xt_target *target = expr->ops->data;
 
@@ -379,7 +379,7 @@ err:
 }
 
 static void
-nft_match_destroy(const struct nft_expr *expr)
+nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
 {
 	struct xt_match *match = expr->ops->data;
 

net/netfilter/nft_ct.c

@@ -321,7 +321,8 @@ static int nft_ct_init(const struct nft_ctx *ctx,
 	return 0;
 }
 
-static void nft_ct_destroy(const struct nft_expr *expr)
+static void nft_ct_destroy(const struct nft_ctx *ctx,
+			   const struct nft_expr *expr)
 {
 	struct nft_ct *priv = nft_expr_priv(expr);
 

net/netfilter/nft_immediate.c

@@ -70,7 +70,8 @@ err1:
 	return err;
 }
 
-static void nft_immediate_destroy(const struct nft_expr *expr)
+static void nft_immediate_destroy(const struct nft_ctx *ctx,
+				  const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg));

net/netfilter/nft_log.c

@@ -74,7 +74,8 @@ static int nft_log_init(const struct nft_ctx *ctx,
 	return 0;
 }
 
-static void nft_log_destroy(const struct nft_expr *expr)
+static void nft_log_destroy(const struct nft_ctx *ctx,
+			    const struct nft_expr *expr)
 {
 	struct nft_log *priv = nft_expr_priv(expr);
 

net/netfilter/nft_lookup.c

@@ -89,7 +89,8 @@ static int nft_lookup_init(const struct nft_ctx *ctx,
 	return 0;
 }
 
-static void nft_lookup_destroy(const struct nft_expr *expr)
+static void nft_lookup_destroy(const struct nft_ctx *ctx,
+			       const struct nft_expr *expr)
 {
 	struct nft_lookup *priv = nft_expr_priv(expr);