l2tp: let iproute2 create L2TPv3 IP tunnels using IPv6

The netlink API lets users create unmanaged L2TPv3 tunnels using
iproute2. Until now, a request to create an unmanaged L2TPv3 IP
encapsulation tunnel over IPv6 would be rejected with
EPROTONOSUPPORT. Now that l2tp_ip6 implements sockets for L2TP IP
encapsulation over IPv6, we can add support for that tunnel type.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 55fc569c8170c22270111b22729dfa1aead909c8..456b52d8f6d893ecd0ef112d2024eeda43b2d3d5 100644 (file)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1368,6 +1368,7 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
        struct sockaddr_in udp_addr;
 #if IS_ENABLED(CONFIG_IPV6)
        struct sockaddr_in6 udp6_addr;
+       struct sockaddr_l2tpip6 ip6_addr;
 #endif
        struct sockaddr_l2tpip ip_addr;
        struct socket *sock = NULL;
@@ -1437,32 +1438,59 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
        case L2TP_ENCAPTYPE_IP:
 #if IS_ENABLED(CONFIG_IPV6)
                if (cfg->local_ip6 && cfg->peer_ip6) {
-                       /* IP encap over IPv6 not yet supported */
-                       err = -EPROTONOSUPPORT;
-                       goto out;
-               }
-#endif
-               err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp);
-               if (err < 0)
-                       goto out;
+                       err = sock_create(AF_INET6, SOCK_DGRAM, IPPROTO_L2TP,
+                                         sockp);
+                       if (err < 0)
+                               goto out;
 
-               sock = *sockp;
+                       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;
+                       memset(&ip6_addr, 0, sizeof(ip6_addr));
+                       ip6_addr.l2tp_family = AF_INET6;
+                       memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6,
+                              sizeof(ip6_addr.l2tp_addr));
+                       ip6_addr.l2tp_conn_id = tunnel_id;
+                       err = kernel_bind(sock, (struct sockaddr *) &ip6_addr,
+                                         sizeof(ip6_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;
+                       ip6_addr.l2tp_family = AF_INET6;
+                       memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6,
+                              sizeof(ip6_addr.l2tp_addr));
+                       ip6_addr.l2tp_conn_id = peer_tunnel_id;
+                       err = kernel_connect(sock,
+                                            (struct sockaddr *) &ip6_addr,
+                                            sizeof(ip6_addr), 0);
+                       if (err < 0)
+                               goto out;
+               } else
+#endif
+               {
+                       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: