netfilter: nf_tables: Carry reset flag in nft_rule_dump_ctx

This relieves the dump callback from having to check nlmsg_type upon
each call and instead performs the check once in .start callback.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>

net/netfilter/nf_tables_api.c

@@ -3443,15 +3443,16 @@ static void audit_log_rule_reset(const struct nft_table *table,
 struct nft_rule_dump_ctx {
 	char *table;
 	char *chain;
+	bool reset;
 };
 
 static int __nf_tables_dump_rules(struct sk_buff *skb,
 				  unsigned int *idx,
 				  struct netlink_callback *cb,
 				  const struct nft_table *table,
-				  const struct nft_chain *chain,
-				  bool reset)
+				  const struct nft_chain *chain)
 {
+	struct nft_rule_dump_ctx *ctx = cb->data;
 	struct net *net = sock_net(skb->sk);
 	const struct nft_rule *rule, *prule;
 	unsigned int s_idx = cb->args[0];
@@ -3475,7 +3476,7 @@ static int __nf_tables_dump_rules(struct sk_buff *skb,
 					NFT_MSG_NEWRULE,
 					NLM_F_MULTI | NLM_F_APPEND,
 					table->family,
-					table, chain, rule, handle, reset) < 0) {
+					table, chain, rule, handle, ctx->reset) < 0) {
 			ret = 1;
 			break;
 		}
@@ -3487,7 +3488,7 @@ static int __nf_tables_dump_rules(struct sk_buff *skb,
 		(*idx)++;
 	}
 
-	if (reset && entries)
+	if (ctx->reset && entries)
 		audit_log_rule_reset(table, cb->seq, entries);
 
 	return ret;
@@ -3504,10 +3505,6 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
 	struct net *net = sock_net(skb->sk);
 	int family = nfmsg->nfgen_family;
 	struct nftables_pernet *nft_net;
-	bool reset = false;
-
-	if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) == NFT_MSG_GETRULE_RESET)
-		reset = true;
 
 	rcu_read_lock();
 	nft_net = nft_pernet(net);
@@ -3532,7 +3529,7 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
 				if (!nft_is_active(net, chain))
 					continue;
 				__nf_tables_dump_rules(skb, &idx,
-						       cb, table, chain, reset);
+						       cb, table, chain);
 				break;
 			}
 			goto done;
@@ -3540,7 +3537,7 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
 
 		list_for_each_entry_rcu(chain, &table->chains, list) {
 			if (__nf_tables_dump_rules(skb, &idx,
-						   cb, table, chain, reset))
+						   cb, table, chain))
 				goto done;
 		}
 
@@ -3578,6 +3575,8 @@ static int nf_tables_dump_rules_start(struct netlink_callback *cb)
 			return -ENOMEM;
 		}
 	}
+	if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) == NFT_MSG_GETRULE_RESET)
+		ctx->reset = true;
 
 	cb->data = ctx;
 	return 0;