netlink: mmaped netlink: ring setup

Add support for mmap'ed RX and TX ring setup and teardown based on the
af_packet.c code. The following patches will use this to add the real
mmap'ed receive and transmit functionality.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 32a354f67ba4..1a85940f8ab7 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -1,6 +1,7 @@
 #ifndef _UAPI__LINUX_NETLINK_H
 #define _UAPI__LINUX_NETLINK_H
 
+#include <linux/kernel.h>
 #include <linux/socket.h> /* for __kernel_sa_family_t */
 #include <linux/types.h>
 
@@ -105,11 +106,42 @@ struct nlmsgerr {
 #define NETLINK_PKTINFO         3
 #define NETLINK_BROADCAST_ERROR 4
 #define NETLINK_NO_ENOBUFS      5
+#define NETLINK_RX_RING         6
+#define NETLINK_TX_RING         7
 
 struct nl_pktinfo {
         __u32   group;
 };
 
+struct nl_mmap_req {
+        unsigned int    nm_block_size;
+        unsigned int    nm_block_nr;
+        unsigned int    nm_frame_size;
+        unsigned int    nm_frame_nr;
+};
+
+struct nl_mmap_hdr {
+        unsigned int    nm_status;
+        unsigned int    nm_len;
+        __u32           nm_group;
+        /* credentials */
+        __u32           nm_pid;
+        __u32           nm_uid;
+        __u32           nm_gid;
+};
+
+enum nl_mmap_status {
+        NL_MMAP_STATUS_UNUSED,
+        NL_MMAP_STATUS_RESERVED,
+        NL_MMAP_STATUS_VALID,
+        NL_MMAP_STATUS_COPY,
+        NL_MMAP_STATUS_SKIP,
+};
+
+#define NL_MMAP_MSG_ALIGNMENT           NLMSG_ALIGNTO
+#define NL_MMAP_MSG_ALIGN(sz)           __ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
+#define NL_MMAP_HDRLEN                  NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
+
 #define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 
 enum {