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Diffstat (limited to 'net/l2tp/l2tp_core.c')
-rw-r--r--net/l2tp/l2tp_core.c82
1 files changed, 65 insertions, 17 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 1a9f3723c13..2ac884d0e89 100644
--- 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);