[L2TP]: Changes to existing ppp and socket kernel headers for L2TP

Add struct sockaddr_pppol2tp to carry L2TP-specific address
information for the PPPoX (PPPoL2TP) socket. Unfortunately we can't
use the union inside struct sockaddr_pppox because the L2TP-specific
data is larger than the current size of the union and we must preserve
the size of struct sockaddr_pppox for binary compatibility.

Also add a PPPIOCGL2TPSTATS ioctl to allow userspace to obtain
L2TP counters and state from the kernel.

Add new if_pppol2tp.h header.

[ Modified to use aligned_u64 in statistics structure -DaveM ]

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

1 files changed, 69 insertions, 0 deletions

diff --git a/include/linux/if_pppol2tp.h b/include/linux/if_pppol2tp.h
new file mode 100644
index 00000000000..516203b6fde
--- /dev/null
+++ b/include/linux/if_pppol2tp.h
@@ -0,0 +1,69 @@
+/***************************************************************************
+ * Linux PPP over L2TP (PPPoL2TP) Socket Implementation (RFC 2661)
+ *
+ * This file supplies definitions required by the PPP over L2TP driver
+ * (pppol2tp.c).  All version information wrt this file is located in pppol2tp.c
+ *
+ * License:
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ */
+
+#ifndef __LINUX_IF_PPPOL2TP_H
+#define __LINUX_IF_PPPOL2TP_H
+
+#include <asm/types.h>
+
+#ifdef __KERNEL__
+#include <linux/in.h>
+#endif
+
+/* Structure used to connect() the socket to a particular tunnel UDP
+ * socket.
+ */
+struct pppol2tp_addr
+{
+        pid_t   pid;                    /* pid that owns the fd.
+                                         * 0 => current */
+        int     fd;                     /* FD of UDP socket to use */
+
+        struct sockaddr_in addr;        /* IP address and port to send to */
+
+        __be16 s_tunnel, s_session;     /* For matching incoming packets */
+        __be16 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
+ *                1 => send packets with sequence numbers
+ * RECVSEQ      - 0 => receive packet sequence numbers are optional
+ *                1 => drop receive packets without sequence numbers
+ * LNSMODE      - 0 => act as LAC.
+ *                1 => act as LNS.
+ * REORDERTO    - reorder timeout (in millisecs). If 0, don't try to reorder.
+ */
+enum {
+        PPPOL2TP_SO_DEBUG       = 1,
+        PPPOL2TP_SO_RECVSEQ     = 2,
+        PPPOL2TP_SO_SENDSEQ     = 3,
+        PPPOL2TP_SO_LNSMODE     = 4,
+        PPPOL2TP_SO_REORDERTO   = 5,
+};
+
+/* Debug message categories for the DEBUG socket option */
+enum {
+        PPPOL2TP_MSG_DEBUG      = (1 << 0),     /* verbose debug (if
+                                                 * compiled in) */
+        PPPOL2TP_MSG_CONTROL    = (1 << 1),     /* userspace - kernel
+                                                 * interface */
+        PPPOL2TP_MSG_SEQ        = (1 << 2),     /* sequence numbers */
+        PPPOL2TP_MSG_DATA       = (1 << 3),     /* data packets */
+};
+
+
+
+#endif