--- ppp-2.4.5/include/linux/if_pppol2tp.h       2009-11-16 22:26:07.000000000 +0000
+++ ppp-2.4.5/include/linux/if_pppol2tp.h       2010-07-16 22:35:22.000000000 +0100
@@ -32,6 +32,20 @@
  	__u16 d_tunnel, d_session;	/* For sending outgoing packets */
 };

+/* The L2TPv3 protocol changes tunnel and session ids from 16 to 32
+ * bits. So we need a different sockaddr structure.
+ */
+struct pppol2tpv3_addr {
+       pid_t   pid;                    /* pid that owns the fd.
+                                        * 0 => current */
+       int     fd;                     /* FD of UDP or IP socket to use */
+
+       struct sockaddr_in addr;        /* IP address and port to send to */
+
+       __u32 s_tunnel, s_session;      /* For matching incoming packets */
+       __u32 d_tunnel, d_session;      /* For sending outgoing packets */
+};
+
 /* Socket options:
  * DEBUG	- bitmask of debug message categories
  * SENDSEQ	- 0 => don't send packets with sequence numbers