Merge remote-tracking branch 'regulator/topic/tps6507x' into regulator-next

[platform/adaptation/renesas_rcar/renesas_kernel.git] / net / l2tp / l2tp_core.c

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 1a9f372..2ac884d 100644 (file)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -168,6 +168,51 @@ l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id)
 
 }
 
+/* Lookup the tunnel socket, possibly involving the fs code if the socket is
+ * owned by userspace.  A struct sock returned from this function must be
+ * released using l2tp_tunnel_sock_put once you're done with it.
+ */
+struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel)
+{
+       int err = 0;
+       struct socket *sock = NULL;
+       struct sock *sk = NULL;
+
+       if (!tunnel)
+               goto out;
+
+       if (tunnel->fd >= 0) {
+               /* Socket is owned by userspace, who might be in the process
+                * of closing it.  Look the socket up using the fd to ensure
+                * consistency.
+                */
+               sock = sockfd_lookup(tunnel->fd, &err);
+               if (sock)
+                       sk = sock->sk;
+       } else {
+               /* Socket is owned by kernelspace */
+               sk = tunnel->sock;
+       }
+
+out:
+       return sk;
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_lookup);
+
+/* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */
+void l2tp_tunnel_sock_put(struct sock *sk)
+{
+       struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
+       if (tunnel) {
+               if (tunnel->fd >= 0) {
+                       /* Socket is owned by userspace */
+                       sockfd_put(sk->sk_socket);
+               }
+               sock_put(sk);
+       }
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put);
+
 /* Lookup a session by id in the global session list
  */
 static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
@@ -1123,8 +1168,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
        struct udphdr *uh;
        struct inet_sock *inet;
        __wsum csum;
-       int old_headroom;
-       int new_headroom;
        int headroom;
        int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
        int udp_len;
@@ -1136,16 +1179,12 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
         */
        headroom = NET_SKB_PAD + sizeof(struct iphdr) +
                uhlen + hdr_len;
-       old_headroom = skb_headroom(skb);
        if (skb_cow_head(skb, headroom)) {
                kfree_skb(skb);
                return NET_XMIT_DROP;
        }
 
-       new_headroom = skb_headroom(skb);
        skb_orphan(skb);
-       skb->truesize += new_headroom - old_headroom;
-
        /* Setup L2TP header */
        session->build_header(session, __skb_push(skb, hdr_len));
 
@@ -1607,6 +1646,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
        tunnel->old_sk_destruct = sk->sk_destruct;
        sk->sk_destruct = &l2tp_tunnel_destruct;
        tunnel->sock = sk;
+       tunnel->fd = fd;
        lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock");
 
        sk->sk_allocation = GFP_ATOMIC;
@@ -1642,24 +1682,32 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create);
  */
 int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
-       int err = 0;
-       struct socket *sock = tunnel->sock ? tunnel->sock->sk_socket : NULL;
+       int err = -EBADF;
+       struct socket *sock = NULL;
+       struct sock *sk = NULL;
+
+       sk = l2tp_tunnel_sock_lookup(tunnel);
+       if (!sk)
+               goto out;
+
+       sock = sk->sk_socket;
+       BUG_ON(!sock);
 
        /* Force the tunnel socket to close. This will eventually
         * cause the tunnel to be deleted via the normal socket close
         * mechanisms when userspace closes the tunnel socket.
         */
-       if (sock != NULL) {
-               err = inet_shutdown(sock, 2);
+       err = inet_shutdown(sock, 2);
 
-               /* If the tunnel's socket was created by the kernel,
-                * close the socket here since the socket was not
-                * created by userspace.
-                */
-               if (sock->file == NULL)
-                       err = inet_release(sock);
-       }
+       /* If the tunnel's socket was created by the kernel,
+        * close the socket here since the socket was not
+        * created by userspace.
+        */
+       if (sock->file == NULL)
+               err = inet_release(sock);
 
+       l2tp_tunnel_sock_put(sk);
+out:
        return err;
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);