netfilter: add helper function to set up the nfnetlink header and use it

This patch adds a helper function to set up the netlink and nfnetlink headers.
Update existing codebase to use it.

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

1 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index f6267e2883f2..791d516e1e88 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -57,6 +57,33 @@ static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
 	return subsys << 8 | msg_type;
 }
 
+static inline void nfnl_fill_hdr(struct nlmsghdr *nlh, u8 family, u8 version,
+				 __be16 res_id)
+{
+	struct nfgenmsg *nfmsg;
+
+	nfmsg = nlmsg_data(nlh);
+	nfmsg->nfgen_family = family;
+	nfmsg->version = version;
+	nfmsg->res_id = res_id;
+}
+
+static inline struct nlmsghdr *nfnl_msg_put(struct sk_buff *skb, u32 portid,
+					    u32 seq, int type, int flags,
+					    u8 family, u8 version,
+					    __be16 res_id)
+{
+	struct nlmsghdr *nlh;
+
+	nlh = nlmsg_put(skb, portid, seq, type, sizeof(struct nfgenmsg), flags);
+	if (!nlh)
+		return NULL;
+
+	nfnl_fill_hdr(nlh, family, version, res_id);
+
+	return nlh;
+}
+
 void nfnl_lock(__u8 subsys_id);
 void nfnl_unlock(__u8 subsys_id);
 #ifdef CONFIG_PROVE_LOCKING