netfilter: nf_tables: delete flowtable hooks via transaction list

Remove inactive bool field in nft_hook object that was introduced in
abadb2f ("netfilter: nf_tables: delete devices from flowtable").
Move stale flowtable hooks to transaction list instead.

Deleting twice the same device does not result in ENOENT.

Fixes: abadb2f ("netfilter: nf_tables: delete devices from flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Author: ummakynes

include/net/netfilter/nf_tables.h

@@ -1090,7 +1090,6 @@ struct nft_stats {
 
 struct nft_hook {
 	struct list_head	list;
-	bool			inactive;
 	struct nf_hook_ops	ops;
 	struct rcu_head		rcu;
 };

net/netfilter/nf_tables_api.c

@@ -1914,7 +1914,6 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net,
 		goto err_hook_dev;
 	}
 	hook->ops.dev = dev;
-	hook->inactive = false;
 
 	return hook;
 
@@ -7618,6 +7617,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 {
 	const struct nlattr * const *nla = ctx->nla;
 	struct nft_flowtable_hook flowtable_hook;
+	LIST_HEAD(flowtable_del_list);
 	struct nft_hook *this, *hook;
 	struct nft_trans *trans;
 	int err;
@@ -7633,7 +7633,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 			err = -ENOENT;
 			goto err_flowtable_del_hook;
 		}
-		hook->inactive = true;
+		list_move(&hook->list, &flowtable_del_list);
 	}
 
 	trans = nft_trans_alloc(ctx, NFT_MSG_DELFLOWTABLE,
@@ -7646,20 +7646,15 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 	nft_trans_flowtable(trans) = flowtable;
 	nft_trans_flowtable_update(trans) = true;
 	INIT_LIST_HEAD(&nft_trans_flowtable_hooks(trans));
+	list_splice(&flowtable_del_list, &nft_trans_flowtable_hooks(trans));
 	nft_flowtable_hook_release(&flowtable_hook);
 
 	nft_trans_commit_list_add_tail(ctx->net, trans);
 
 	return 0;
 
 err_flowtable_del_hook:
-	list_for_each_entry(this, &flowtable_hook.list, list) {
-		hook = nft_hook_list_find(&flowtable->hook_list, this);
-		if (!hook)
-			break;
-
-		hook->inactive = false;
-	}
+	list_splice(&flowtable_del_list, &flowtable->hook_list);
 	nft_flowtable_hook_release(&flowtable_hook);
 
 	return err;
@@ -8563,17 +8558,6 @@ void nft_chain_del(struct nft_chain *chain)
 	list_del_rcu(&chain->list);
 }
 
-static void nft_flowtable_hooks_del(struct nft_flowtable *flowtable,
-				    struct list_head *hook_list)
-{
-	struct nft_hook *hook, *next;
-
-	list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) {
-		if (hook->inactive)
-			list_move(&hook->list, hook_list);
-	}
-}
-
 static void nf_tables_module_autoload_cleanup(struct net *net)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
@@ -8918,8 +8902,6 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 			break;
 		case NFT_MSG_DELFLOWTABLE:
 			if (nft_trans_flowtable_update(trans)) {
-				nft_flowtable_hooks_del(nft_trans_flowtable(trans),
-							&nft_trans_flowtable_hooks(trans));
 				nf_tables_flowtable_notify(&trans->ctx,
 							   nft_trans_flowtable(trans),
 							   &nft_trans_flowtable_hooks(trans),
@@ -9000,7 +8982,6 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 	struct nftables_pernet *nft_net = nft_pernet(net);
 	struct nft_trans *trans, *next;
 	struct nft_trans_elem *te;
-	struct nft_hook *hook;
 
 	if (action == NFNL_ABORT_VALIDATE &&
 	    nf_tables_validate(net) < 0)
@@ -9131,8 +9112,8 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 			break;
 		case NFT_MSG_DELFLOWTABLE:
 			if (nft_trans_flowtable_update(trans)) {
-				list_for_each_entry(hook, &nft_trans_flowtable(trans)->hook_list, list)
-					hook->inactive = false;
+				list_splice(&nft_trans_flowtable_hooks(trans),
+					    &nft_trans_flowtable(trans)->hook_list);
 			} else {
 				trans->ctx.table->use++;
 				nft_clear(trans->ctx.net, nft_trans_flowtable(trans));