netfilter: nf_tables: simplify NLM_F_CREATE handling

* From nf_tables_newchain(), codepath provides context that allows us to
  infer if we are updating a chain (in that case, no module autoload is
  required) or adding a new one (then, module autoload is indeed
  needed).
* We only need it in one single spot in nf_tables_newrule().
* Not needed for nf_tables_newset() at all.

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 debc168..67cdd5c 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1442,7 +1442,7 @@ struct nft_chain_hook {
 static int nft_chain_parse_hook(struct net *net,
                                const struct nlattr * const nla[],
                                struct nft_chain_hook *hook, u8 family,
-                               bool create)
+                               bool autoload)
 {
        struct nlattr *ha[NFTA_HOOK_MAX + 1];
        const struct nft_chain_type *type;
@@ -1467,7 +1467,7 @@ static int nft_chain_parse_hook(struct net *net,
        type = chain_type[family][NFT_CHAIN_T_DEFAULT];
        if (nla[NFTA_CHAIN_TYPE]) {
                type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE],
-                                                  family, create);
+                                                  family, autoload);
                if (IS_ERR(type))
                        return PTR_ERR(type);
        }
@@ -1534,7 +1534,7 @@ static struct nft_rule **nf_tables_chain_alloc_rules(const struct nft_chain *cha
 }
 
 static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
-                             u8 policy, bool create)
+                             u8 policy)
 {
        const struct nlattr * const *nla = ctx->nla;
        struct nft_table *table = ctx->table;
@@ -1552,7 +1552,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
                struct nft_chain_hook hook;
                struct nf_hook_ops *ops;
 
-               err = nft_chain_parse_hook(net, nla, &hook, family, create);
+               err = nft_chain_parse_hook(net, nla, &hook, family, true);
                if (err < 0)
                        return err;
 
@@ -1643,8 +1643,7 @@ err1:
        return err;
 }
 
-static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
-                             bool create)
+static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy)
 {
        const struct nlattr * const *nla = ctx->nla;
        struct nft_table *table = ctx->table;
@@ -1661,7 +1660,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
                        return -EBUSY;
 
                err = nft_chain_parse_hook(ctx->net, nla, &hook, ctx->family,
-                                          create);
+                                          false);
                if (err < 0)
                        return err;
 
@@ -1761,9 +1760,6 @@ static int nf_tables_newchain(struct net *net, struct sock *nlsk,
        u8 policy = NF_ACCEPT;
        struct nft_ctx ctx;
        u64 handle = 0;
-       bool create;
-
-       create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false;
 
        lockdep_assert_held(&net->nft.commit_mutex);
 
@@ -1828,10 +1824,10 @@ static int nf_tables_newchain(struct net *net, struct sock *nlsk,
                if (nlh->nlmsg_flags & NLM_F_REPLACE)
                        return -EOPNOTSUPP;
 
-               return nf_tables_updchain(&ctx, genmask, policy, create);
+               return nf_tables_updchain(&ctx, genmask, policy);
        }
 
-       return nf_tables_addchain(&ctx, family, genmask, policy, create);
+       return nf_tables_addchain(&ctx, family, genmask, policy);
 }
 
 static int nf_tables_delchain(struct net *net, struct sock *nlsk,
@@ -2529,13 +2525,10 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
        struct nlattr *tmp;
        unsigned int size, i, n, ulen = 0, usize = 0;
        int err, rem;
-       bool create;
        u64 handle, pos_handle;
 
        lockdep_assert_held(&net->nft.commit_mutex);
 
-       create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false;
-
        table = nft_table_lookup(net, nla[NFTA_RULE_TABLE], family, genmask);
        if (IS_ERR(table)) {
                NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_TABLE]);
@@ -2565,7 +2558,8 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
                else
                        return -EOPNOTSUPP;
        } else {
-               if (!create || nlh->nlmsg_flags & NLM_F_REPLACE)
+               if (!(nlh->nlmsg_flags & NLM_F_CREATE) ||
+                   nlh->nlmsg_flags & NLM_F_REPLACE)
                        return -EINVAL;
                handle = nf_tables_alloc_handle(table);
 
@@ -3361,7 +3355,6 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
        struct nft_ctx ctx;
        char *name;
        unsigned int size;
-       bool create;
        u64 timeout;
        u32 ktype, dtype, flags, policy, gc_int, objtype;
        struct nft_set_desc desc;
@@ -3462,8 +3455,6 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
                        return err;
        }
 
-       create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false;
-
        table = nft_table_lookup(net, nla[NFTA_SET_TABLE], family, genmask);
        if (IS_ERR(table)) {
                NL_SET_BAD_ATTR(extack, nla[NFTA_SET_TABLE]);