[NET]: unify netlink kernel socket recognition

There are currently two ways to determine whether the netlink socket is a
kernel one or a user one. This patch creates a single inline call for
this purpose and unifies all the calls in the af_netlink.c

No similar calls are found outside af_netlink.c.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 4 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a5bd63ca86bc..4ce7dcbcb6ef 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -92,6 +92,11 @@ static inline struct netlink_sock *nlk_sk(struct sock *sk)
         return container_of(sk, struct netlink_sock, sk);
 }
 
+static inline int netlink_is_kernel(struct sock *sk)
+{
+        return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
+}
+
 struct nl_pid_hash {
         struct hlist_head *table;
         unsigned long rehash_time;
@@ -489,7 +494,7 @@ static int netlink_release(struct socket *sock)
         module_put(nlk->module);
 
         netlink_table_grab();
-        if (nlk->flags & NETLINK_KERNEL_SOCKET) {
+        if (netlink_is_kernel(sk)) {
                 kfree(nl_table[sk->sk_protocol].listeners);
                 nl_table[sk->sk_protocol].module = NULL;
                 nl_table[sk->sk_protocol].registered = 0;
@@ -716,7 +721,7 @@ static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
 
         /* Don't bother queuing skb if kernel socket has no input function */
         nlk = nlk_sk(sock);
-        if ((nlk->pid == 0 && !nlk->data_ready) ||
+        if ((netlink_is_kernel(sock) && !nlk->data_ready) ||
             (sock->sk_state == NETLINK_CONNECTED &&
              nlk->dst_pid != nlk_sk(ssk)->pid)) {
                 sock_put(sock);
@@ -762,7 +767,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
             test_bit(0, &nlk->state)) {
                 DECLARE_WAITQUEUE(wait, current);
                 if (!timeo) {
-                        if (!ssk || nlk_sk(ssk)->pid == 0)
+                        if (!ssk || netlink_is_kernel(ssk))
                                 netlink_overrun(sk);
                         sock_put(sk);
                         kfree_skb(skb);
@@ -861,7 +866,7 @@ int netlink_has_listeners(struct sock *sk, unsigned int group)
         int res = 0;
         unsigned long *listeners;
 
-        BUG_ON(!(nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET));
+        BUG_ON(!netlink_is_kernel(sk));
 
         rcu_read_lock();
         listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);