3 files changed, 126 insertions, 14 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 473cf2d6390..13ed85baf4e 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1218,6 +1218,82 @@ void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_free);
 
+/* Create a socket for the tunnel, if one isn't set up by
+ * userspace. This is used for static tunnels where there is no
+ * managing L2TP daemon.
+ */
+static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct socket **sockp)
+{
+	int err = -EINVAL;
+	struct sockaddr_in udp_addr;
+	struct sockaddr_l2tpip ip_addr;
+	struct socket *sock;
+
+	switch (cfg->encap) {
+	case L2TP_ENCAPTYPE_UDP:
+		err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp);
+		if (err < 0)
+			goto out;
+
+		sock = *sockp;
+
+		memset(&udp_addr, 0, sizeof(udp_addr));
+		udp_addr.sin_family = AF_INET;
+		udp_addr.sin_addr = cfg->local_ip;
+		udp_addr.sin_port = htons(cfg->local_udp_port);
+		err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr));
+		if (err < 0)
+			goto out;
+
+		udp_addr.sin_family = AF_INET;
+		udp_addr.sin_addr = cfg->peer_ip;
+		udp_addr.sin_port = htons(cfg->peer_udp_port);
+		err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0);
+		if (err < 0)
+			goto out;
+
+		if (!cfg->use_udp_checksums)
+			sock->sk->sk_no_check = UDP_CSUM_NOXMIT;
+
+		break;
+
+	case L2TP_ENCAPTYPE_IP:
+		err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp);
+		if (err < 0)
+			goto out;
+
+		sock = *sockp;
+
+		memset(&ip_addr, 0, sizeof(ip_addr));
+		ip_addr.l2tp_family = AF_INET;
+		ip_addr.l2tp_addr = cfg->local_ip;
+		ip_addr.l2tp_conn_id = tunnel_id;
+		err = kernel_bind(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr));
+		if (err < 0)
+			goto out;
+
+		ip_addr.l2tp_family = AF_INET;
+		ip_addr.l2tp_addr = cfg->peer_ip;
+		ip_addr.l2tp_conn_id = peer_tunnel_id;
+		err = kernel_connect(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr), 0);
+		if (err < 0)
+			goto out;
+
+		break;
+
+	default:
+		goto out;
+	}
+
+out:
+	if ((err < 0) && sock) {
+		sock_release(sock);
+		*sockp = NULL;
+	}
+
+	return err;
+}
+
 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp)
 {
 	struct l2tp_tunnel *tunnel = NULL;
@@ -1228,14 +1304,21 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP;
 
 	/* Get the tunnel socket from the fd, which was opened by
-	 * the userspace L2TP daemon.
+	 * the userspace L2TP daemon. If not specified, create a
+	 * kernel socket.
 	 */
-	err = -EBADF;
-	sock = sockfd_lookup(fd, &err);
-	if (!sock) {
-		printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
-		       tunnel_id, fd, err);
-		goto err;
+	if (fd < 0) {
+		err = l2tp_tunnel_sock_create(tunnel_id, peer_tunnel_id, cfg, &sock);
+		if (err < 0)
+			goto err;
+	} else {
+		err = -EBADF;
+		sock = sockfd_lookup(fd, &err);
+		if (!sock) {
+			printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
+			       tunnel_id, fd, err);
+			goto err;
+		}
 	}
 
 	sk = sock->sk;
@@ -1329,7 +1412,10 @@ err:
 	if (tunnelp)
 		*tunnelp = tunnel;
 
-	if (sock)
+	/* If tunnel's socket was created by the kernel, it doesn't
+	 *  have a file.
+	 */
+	if (sock && sock->file)
 		sockfd_put(sock);
 
 	return err;
@@ -1341,13 +1427,22 @@ 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;
 
 	/* 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 ((tunnel->sock != NULL) && (tunnel->sock->sk_socket != NULL))
-		err = inet_shutdown(tunnel->sock->sk_socket, 2);
+	if (sock != NULL) {
+		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);
+	}
 
 	return err;
 }
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 571335530c6..a961c77e086 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -146,6 +146,13 @@ struct l2tp_tunnel_cfg {
 	int			debug;		/* bitmask of debug message
 						 * categories */
 	enum l2tp_encap_type	encap;
+
+	/* Used only for kernel-created sockets */
+	struct in_addr		local_ip;
+	struct in_addr		peer_ip;
+	u16			local_udp_port;
+	u16			peer_udp_port;
+	int			use_udp_checksums:1;
 };
 
 struct l2tp_tunnel {
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 3d0f7f6f748..12341a6cc70 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -129,11 +129,21 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info
 	}
 	cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 
-	if (!info->attrs[L2TP_ATTR_FD]) {
-		ret = -EINVAL;
-		goto out;
+	fd = -1;
+	if (info->attrs[L2TP_ATTR_FD]) {
+		fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
+	} else {
+		if (info->attrs[L2TP_ATTR_IP_SADDR])
+			cfg.local_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_SADDR]);
+		if (info->attrs[L2TP_ATTR_IP_DADDR])
+			cfg.peer_ip.s_addr = nla_get_be32(info->attrs[L2TP_ATTR_IP_DADDR]);
+		if (info->attrs[L2TP_ATTR_UDP_SPORT])
+			cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
+		if (info->attrs[L2TP_ATTR_UDP_DPORT])
+			cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
+		if (info->attrs[L2TP_ATTR_UDP_CSUM])
+			cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
 	}
-	fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 
 	if (info->attrs[L2TP_ATTR_DEBUG])
 		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);