nfsd: add a header describing upcall to nfsdcld

The daemon takes a versioned binary struct. Hopefully this should allow
us to revise the struct later if it becomes necessary.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/include/linux/nfsd/cld.h b/include/linux/nfsd/cld.h
new file mode 100644
index 000000000000..f14a9ab06f1f
--- /dev/null
+++ b/include/linux/nfsd/cld.h
@@ -0,0 +1,56 @@
+/*
+ * Upcall description for nfsdcld communication
+ *
+ * Copyright (c) 2012 Red Hat, Inc.
+ * Author(s): Jeff Layton <jlayton@redhat.com>
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _NFSD_CLD_H
+#define _NFSD_CLD_H
+
+/* latest upcall version available */
+#define CLD_UPCALL_VERSION 1
+
+/* defined by RFC3530 */
+#define NFS4_OPAQUE_LIMIT 1024
+
+enum cld_command {
+        Cld_Create,             /* create a record for this cm_id */
+        Cld_Remove,             /* remove record of this cm_id */
+        Cld_Check,              /* is this cm_id allowed? */
+        Cld_GraceDone,          /* grace period is complete */
+};
+
+/* representation of long-form NFSv4 client ID */
+struct cld_name {
+        uint16_t        cn_len;                         /* length of cm_id */
+        unsigned char   cn_id[NFS4_OPAQUE_LIMIT];       /* client-provided */
+} __attribute__((packed));
+
+/* message struct for communication with userspace */
+struct cld_msg {
+        uint8_t         cm_vers;                /* upcall version */
+        uint8_t         cm_cmd;                 /* upcall command */
+        int16_t         cm_status;              /* return code */
+        uint32_t        cm_xid;                 /* transaction id */
+        union {
+                int64_t         cm_gracetime;   /* grace period start time */
+                struct cld_name cm_name;
+        } __attribute__((packed)) cm_u;
+} __attribute__((packed));
+
+#endif /* !_NFSD_CLD_H */