netfilter: nf_tables: allow to create netdev chain without device

Relax netdev chain creation to allow for loading the ruleset, then
adding/deleting devices at a later stage. Hardware offload does not
support for this feature yet.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c55ac3d..0954295 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2023,10 +2023,9 @@ struct nft_chain_hook {
        struct list_head                list;
 };
 
-static int nft_chain_parse_netdev(struct net *net,
-                                 struct nlattr *tb[],
+static int nft_chain_parse_netdev(struct net *net, struct nlattr *tb[],
                                  struct list_head *hook_list,
-                                 struct netlink_ext_ack *extack)
+                                 struct netlink_ext_ack *extack, u32 flags)
 {
        struct nft_hook *hook;
        int err;
@@ -2045,12 +2044,12 @@ static int nft_chain_parse_netdev(struct net *net,
                if (err < 0)
                        return err;
 
-               if (list_empty(hook_list))
-                       return -EINVAL;
-       } else {
-               return -EINVAL;
        }
 
+       if (flags & NFT_CHAIN_HW_OFFLOAD &&
+           list_empty(hook_list))
+               return -EINVAL;
+
        return 0;
 }
 
@@ -2058,7 +2057,7 @@ static int nft_chain_parse_hook(struct net *net,
                                struct nft_base_chain *basechain,
                                const struct nlattr * const nla[],
                                struct nft_chain_hook *hook, u8 family,
-                               struct netlink_ext_ack *extack)
+                               u32 flags, struct netlink_ext_ack *extack)
 {
        struct nftables_pernet *nft_net = nft_pernet(net);
        struct nlattr *ha[NFTA_HOOK_MAX + 1];
@@ -2125,7 +2124,7 @@ static int nft_chain_parse_hook(struct net *net,
 
        INIT_LIST_HEAD(&hook->list);
        if (nft_base_chain_netdev(family, hook->num)) {
-               err = nft_chain_parse_netdev(net, ha, &hook->list, extack);
+               err = nft_chain_parse_netdev(net, ha, &hook->list, extack, flags);
                if (err < 0) {
                        module_put(type->owner);
                        return err;
@@ -2263,7 +2262,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
                if (flags & NFT_CHAIN_BINDING)
                        return -EOPNOTSUPP;
 
-               err = nft_chain_parse_hook(net, NULL, nla, &hook, family,
+               err = nft_chain_parse_hook(net, NULL, nla, &hook, family, flags,
                                           extack);
                if (err < 0)
                        return err;
@@ -2407,7 +2406,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 
                basechain = nft_base_chain(chain);
                err = nft_chain_parse_hook(ctx->net, basechain, nla, &hook,
-                                          ctx->family, extack);
+                                          ctx->family, flags, extack);
                if (err < 0)
                        return err;
 
@@ -2683,7 +2682,7 @@ static int nft_delchain_hook(struct nft_ctx *ctx, struct nft_chain *chain,
 
        basechain = nft_base_chain(chain);
        err = nft_chain_parse_hook(ctx->net, basechain, nla, &chain_hook,
-                                  ctx->family, extack);
+                                  ctx->family, chain->flags, extack);
        if (err < 0)
                return err;