netfilter: nf_tables: add AF specific expression support

For the reject module, we need to add AF-specific implementations to
get rid of incorrect module dependencies. Try to load an AF-specific
module first and fall back to generic modules.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 16 insertions, 6 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3c5a219f4242..113c469c7579 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1114,35 +1114,45 @@ void nft_unregister_expr(struct nft_expr_type *type)
 }
 EXPORT_SYMBOL_GPL(nft_unregister_expr);
 
-static const struct nft_expr_type *__nft_expr_type_get(struct nlattr *nla)
+static const struct nft_expr_type *__nft_expr_type_get(u8 family,
+                                                       struct nlattr *nla)
 {
         const struct nft_expr_type *type;
 
         list_for_each_entry(type, &nf_tables_expressions, list) {
-                if (!nla_strcmp(nla, type->name))
+                if (!nla_strcmp(nla, type->name) &&
+                    (!type->family || type->family == family))
                         return type;
         }
         return NULL;
 }
 
-static const struct nft_expr_type *nft_expr_type_get(struct nlattr *nla)
+static const struct nft_expr_type *nft_expr_type_get(u8 family,
+                                                     struct nlattr *nla)
 {
         const struct nft_expr_type *type;
 
         if (nla == NULL)
                 return ERR_PTR(-EINVAL);
 
-        type = __nft_expr_type_get(nla);
+        type = __nft_expr_type_get(family, nla);
         if (type != NULL && try_module_get(type->owner))
                 return type;
 
 #ifdef CONFIG_MODULES
         if (type == NULL) {
                 nfnl_unlock(NFNL_SUBSYS_NFTABLES);
+                request_module("nft-expr-%u-%.*s", family,
+                               nla_len(nla), (char *)nla_data(nla));
+                nfnl_lock(NFNL_SUBSYS_NFTABLES);
+                if (__nft_expr_type_get(family, nla))
+                        return ERR_PTR(-EAGAIN);
+
+                nfnl_unlock(NFNL_SUBSYS_NFTABLES);
                 request_module("nft-expr-%.*s",
                                nla_len(nla), (char *)nla_data(nla));
                 nfnl_lock(NFNL_SUBSYS_NFTABLES);
-                if (__nft_expr_type_get(nla))
+                if (__nft_expr_type_get(family, nla))
                         return ERR_PTR(-EAGAIN);
         }
 #endif
@@ -1193,7 +1203,7 @@ static int nf_tables_expr_parse(const struct nft_ctx *ctx,
         if (err < 0)
                 return err;
 
-        type = nft_expr_type_get(tb[NFTA_EXPR_NAME]);
+        type = nft_expr_type_get(ctx->afi->family, tb[NFTA_EXPR_NAME]);
         if (IS_ERR(type))
                 return PTR_ERR(type);