[nf-next PATCH v4 07/16] netfilter: nf_tables: Introduce nft_hook_find_ops()

[Phil Sutter <phil@nwl.cc>]

Also a pretty dull wrapper around the hook->ops.dev comparison for now.
Will search the embedded nf_hook_ops list in future. The ugly cast to
eliminate the const qualifier will vanish then, too.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 include/net/netfilter/nf_tables.h |  3 +++
 net/netfilter/nf_tables_api.c     | 14 +++++++++++++-
 net/netfilter/nf_tables_offload.c |  2 +-
 net/netfilter/nft_chain_filter.c  |  6 ++++--
 net/netfilter/nft_flow_offload.c  |  2 +-
 5 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 6aa39c4a8c3c..37d1110ccfd9 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1196,6 +1196,9 @@ struct nft_hook {
 	u8			ifnamelen;
 };
 
+struct nf_hook_ops *nft_hook_find_ops(const struct nft_hook *hook,
+				      const struct net_device *dev);
+
 /**
  *	struct nft_base_chain - nf_tables base chain
  *
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a0482c7fc659..8326395c5752 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9253,13 +9253,25 @@ static int nf_tables_fill_gen_info(struct sk_buff *skb, struct net *net,
 	return -EMSGSIZE;
 }
 
+struct nf_hook_ops *nft_hook_find_ops(const struct nft_hook *hook,
+				      const struct net_device *dev)
+{
+	if (hook->ops.dev == dev)
+		return (struct nf_hook_ops *)&hook->ops;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(nft_hook_find_ops);
+
 static void nft_flowtable_event(unsigned long event, struct net_device *dev,
 				struct nft_flowtable *flowtable)
 {
+	struct nf_hook_ops *ops;
 	struct nft_hook *hook;
 
 	list_for_each_entry(hook, &flowtable->hook_list, list) {
-		if (hook->ops.dev != dev)
+		ops = nft_hook_find_ops(hook, dev);
+		if (!ops)
 			continue;
 
 		/* flow_offload_netdev_event() cleans up entries for us. */
diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index 64675f1c7f29..75b756f0b9f0 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -638,7 +638,7 @@ static struct nft_chain *__nft_offload_get_chain(const struct nftables_pernet *n
 			found = NULL;
 			basechain = nft_base_chain(chain);
 			list_for_each_entry(hook, &basechain->hook_list, list) {
-				if (hook->ops.dev != dev)
+				if (!nft_hook_find_ops(hook, dev))
 					continue;
 
 				found = hook;
diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
index 543f258b7c6b..d34c6fe7ba72 100644
--- a/net/netfilter/nft_chain_filter.c
+++ b/net/netfilter/nft_chain_filter.c
@@ -322,14 +322,16 @@ static void nft_netdev_event(unsigned long event, struct net_device *dev,
 			     struct nft_ctx *ctx)
 {
 	struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
+	struct nf_hook_ops *ops;
 	struct nft_hook *hook;
 
 	list_for_each_entry(hook, &basechain->hook_list, list) {
-		if (hook->ops.dev != dev)
+		ops = nft_hook_find_ops(hook, dev);
+		if (!ops)
 			continue;
 
 		if (!(ctx->chain->table->flags & NFT_TABLE_F_DORMANT))
-			nf_unregister_net_hook(ctx->net, &hook->ops);
+			nf_unregister_net_hook(ctx->net, ops);
 
 		list_del_rcu(&hook->list);
 		kfree_rcu(hook, rcu);
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 2f732fae5a83..83415d7aadda 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -175,7 +175,7 @@ static bool nft_flowtable_find_dev(const struct net_device *dev,
 	bool found = false;
 
 	list_for_each_entry_rcu(hook, &ft->hook_list, list) {
-		if (hook->ops.dev != dev)
+		if (!nft_hook_find_ops(hook, dev))
 			continue;
 
 		found = true;
-- 
2.43.0