[NET]: Introduce the sk_detach_filter() call

Filter is attached in a separate function, so do the
same for filter detaching.

This also removes one variable sock_setsockopt().

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 17 insertions, 11 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index bd903aaf7aa7..fd607581ab50 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -433,5 +433,21 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
         return err;
 }
 
+int sk_detach_filter(struct sock *sk)
+{
+        int ret = -ENOENT;
+        struct sk_filter *filter;
+
+        rcu_read_lock_bh();
+        filter = rcu_dereference(sk->sk_filter);
+        if (filter) {
+                rcu_assign_pointer(sk->sk_filter, NULL);
+                sk_filter_release(sk, filter);
+                ret = 0;
+        }
+        rcu_read_unlock_bh();
+        return ret;
+}
+
 EXPORT_SYMBOL(sk_chk_filter);
 EXPORT_SYMBOL(sk_run_filter);
diff --git a/net/core/sock.c b/net/core/sock.c
index d45ecdccc6a1..07101381b8b7 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -428,7 +428,6 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
                     char __user *optval, int optlen)
 {
         struct sock *sk=sock->sk;
-        struct sk_filter *filter;
         int val;
         int valbool;
         struct linger ling;
@@ -652,16 +651,7 @@ set_rcvbuf:
                 break;
 
         case SO_DETACH_FILTER:
-                rcu_read_lock_bh();
-                filter = rcu_dereference(sk->sk_filter);
-                if (filter) {
-                        rcu_assign_pointer(sk->sk_filter, NULL);
-                        sk_filter_release(sk, filter);
-                        rcu_read_unlock_bh();
-                        break;
-                }
-                rcu_read_unlock_bh();
-                ret = -ENONET;
+                ret = sk_detach_filter(sk);
                 break;
 
         case SO_PASSSEC: