[PATCH 3/2,v2] netfilter: nf_tables: delete flowtable hooks via transaction list

[Pablo Neira Ayuso <pablo@netfilter.org>]

Remove inactive bool field in nft_hook object that was introduced in
abadb2f865d7 ("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: abadb2f865d7 ("netfilter: nf_tables: delete devices from flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v2: add Fixes: tag

 include/net/netfilter/nf_tables.h |  1 -
 net/netfilter/nf_tables_api.c     | 40 ++++++++-----------------------
 2 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 20af9d3557b9..279ae0fff7ad 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/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;
 };
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 7c9eb8e42ea6..5c28b298c201 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/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;
 
@@ -7602,7 +7601,8 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 {
 	const struct nlattr * const *nla = ctx->nla;
 	struct nft_flowtable_hook flowtable_hook;
-	struct nft_hook *this, *hook;
+	struct nft_hook *this, *next, *hook;
+	LIST_HEAD(flowtable_del_list);
 	struct nft_trans *trans;
 	int err;
 
@@ -7611,13 +7611,13 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 	if (err < 0)
 		return err;
 
-	list_for_each_entry(this, &flowtable_hook.list, list) {
+	list_for_each_entry_safe(this, next, &flowtable_hook.list, list) {
 		hook = nft_hook_list_find(&flowtable->hook_list, this);
 		if (!hook) {
 			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,
@@ -7630,6 +7630,7 @@ 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);
@@ -7637,13 +7638,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
 	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;
@@ -8327,9 +8322,8 @@ static void nft_commit_release(struct nft_trans *trans)
 		nft_obj_destroy(&trans->ctx, nft_trans_obj(trans));
 		break;
 	case NFT_MSG_DELFLOWTABLE:
-		if (nft_trans_flowtable_update(trans))
-			nft_flowtable_hooks_destroy(&nft_trans_flowtable_hooks(trans));
-		else
+		nft_flowtable_hooks_destroy(&nft_trans_flowtable_hooks(trans));
+		if (!nft_trans_flowtable_update(trans))
 			nf_tables_flowtable_destroy(nft_trans_flowtable(trans));
 		break;
 	}
@@ -8549,17 +8543,6 @@ 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);
@@ -8904,8 +8887,6 @@ 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),
@@ -8986,7 +8967,6 @@ 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)
@@ -9117,8 +9097,8 @@ 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));
-- 
2.30.2