netlink: constify nlmsghdr arguments
Consitfy nlmsghdr arguments to a couple of functions as preparation
for the next patch, which will constify the netlink message data in
all nfnetlink users.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 3c1895e..85ba560 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -14,7 +14,7 @@
extern int rtnl_unregister(int protocol, int msgtype);
extern void rtnl_unregister_all(int protocol);
-static inline int rtnl_msg_family(struct nlmsghdr *nlh)
+static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
{
if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;