3 files changed, 126 insertions, 14 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 473cf2d63905..13ed85baf4e9 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 571335530c6f..a961c77e0867 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 3d0f7f6f7488..12341a6cc70e 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]);