[PATCH nf-next] netfilter: nf_tables_offload: Fix unbind devices when subsequent device bind failed

[PATCH nf-next] netfilter: nf_tables_offload: Fix unbind devices when subsequent device bind failed

[wenxu]

From: wenxu <wenxu@ucloud.cn>

In the nft_flow_block_chain some devices bind success, but the subsequent
device failed. It should unbind the successful devices.

Fixes: bbaef955af6e ("netfilter: nf_tables: support for multiple devices per netdev hook")
Signed-off-by: wenxu <wenxu@ucloud.cn>
---
 net/netfilter/nf_tables_offload.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index beeb74f..037c6bd 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -322,8 +322,9 @@ static int nft_flow_block_chain(struct nft_base_chain *basechain,
 {
 	struct net_device *dev;
 	struct nft_hook *hook;
-	int err;
+	int err, i;
 
+	i = 0;
 	list_for_each_entry(hook, &basechain->hook_list, list) {
 		dev = hook->ops.dev;
 		if (this_dev && this_dev != dev)
@@ -333,12 +334,28 @@ static int nft_flow_block_chain(struct nft_base_chain *basechain,
 			err = nft_block_offload_cmd(basechain, dev, cmd);
 		else
 			err = nft_indr_block_offload_cmd(basechain, dev, cmd);
-
-		if (err < 0)
-			return err;
+
+		if (err < 0) {
+			if (this_dev)
+				return err;
+			else if (cmd == FLOW_BLOCK_BIND)
+				goto err_unbind;
+		}
+		i++;
 	}
 
 	return 0;
+
+err_unbind:
+	list_for_each_entry(hook, &basechain->hook_list, list) {
+		if (i-- <= 0)
+			break;
+
+		dev = hook->ops.dev;
+		nft_flow_block_chain(basechain, dev, FLOW_BLOCK_UNBIND);
+	}
+
+	return err;
 }
 
 static int nft_flow_offload_chain(struct nft_chain *chain, u8 *ppolicy,
-- 
1.8.3.1

Re: [PATCH nf-next] netfilter: nf_tables_offload: Fix unbind devices when subsequent device bind failed

[Pablo Neira Ayuso]

On Thu, Oct 24, 2019 at 11:55:22AM +0800, wenxu@ucloud.cn wrote:
> From: wenxu <wenxu@ucloud.cn>
> 
> In the nft_flow_block_chain some devices bind success, but the subsequent
> device failed. It should unbind the successful devices.

Thank you for you patch, although I decided to follow a different path:

https://patchwork.ozlabs.org/patch/1182733/