/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
/*
* 1999 Copyright (C) Pavel Machek, [email protected]. This code is GPL.
* 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
* Made nbd_end_request() use the io_request_lock
* 2001 Copyright (C) Steven Whitehouse
* New nbd_end_request() for compatibility with new linux block
* layer code.
* 2003/06/24 Louis D. Langholtz <[email protected]>
* Removed unneeded blksize_bits field from nbd_device struct.
* Cleanup PARANOIA usage & code.
* 2004/02/19 Paul Clements
* Removed PARANOIA, plus various cleanup and comments
* 2023 Copyright Red Hat
* Link to userspace extensions, favor cookie over handle.
*/
#ifndef LINUX_NBD_H
#define LINUX_NBD_H
#include <linux/types.h>
#define NBD_SET_SOCK _IO( 0xab, 0 )
#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
#define NBD_SET_SIZE _IO( 0xab, 2 )
#define NBD_DO_IT _IO( 0xab, 3 )
#define NBD_CLEAR_SOCK _IO( 0xab, 4 )
#define NBD_CLEAR_QUE _IO( 0xab, 5 )
#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
#define NBD_DISCONNECT _IO( 0xab, 8 )
#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
#define NBD_SET_FLAGS _IO( 0xab, 10)
/*
* See also https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md
* for additional userspace extensions not yet utilized in the kernel module.
*/
enum {
NBD_CMD_READ = 0,
NBD_CMD_WRITE = 1,
NBD_CMD_DISC = 2,
NBD_CMD_FLUSH = 3,
NBD_CMD_TRIM = 4,
/* userspace defines additional extension commands */
NBD_CMD_WRITE_ZEROES = 6,
};
/* values for flags field, these are server interaction specific. */
#define NBD_FLAG_HAS_FLAGS (1 << 0) /* nbd-server supports flags */
#define NBD_FLAG_READ_ONLY (1 << 1) /* device is read-only */
#define NBD_FLAG_SEND_FLUSH (1 << 2) /* can flush writeback cache */
#define NBD_FLAG_SEND_FUA (1 << 3) /* send FUA (forced unit access) */
#define NBD_FLAG_ROTATIONAL (1 << 4) /* device is rotational */
#define NBD_FLAG_SEND_TRIM (1 << 5) /* send trim/discard */
#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* supports WRITE_ZEROES */
/* there is a gap here to match userspace */
#define NBD_FLAG_CAN_MULTI_CONN (1 << 8) /* Server supports multiple connections per export. */
/* values for cmd flags in the upper 16 bits of request type */
#define NBD_CMD_FLAG_FUA (1 << 16) /* FUA (forced unit access) op */
#define NBD_CMD_FLAG_NO_HOLE (1 << 17) /* Do not punch a hole for WRITE_ZEROES */
/* These are client behavior specific flags. */
#define NBD_CFLAG_DESTROY_ON_DISCONNECT (1 << 0) /* delete the nbd device on
disconnect. */
#define NBD_CFLAG_DISCONNECT_ON_CLOSE (1 << 1) /* disconnect the nbd device on
* close by last opener.
*/
/* userspace doesn't need the nbd_device structure */
/* These are sent over the network in the request/reply magic fields */
#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
/* Do *not* use magics: 0x12560953 0x96744668. */
/* magic 0x668e33ef for structured reply not supported by kernel yet */
/*
* This is the packet used for communication between client and
* server. All data are in network byte order.
*/
struct nbd_request {
__be32 magic; /* NBD_REQUEST_MAGIC */
__be32 type; /* See NBD_CMD_* */
union {
__be64 cookie; /* Opaque identifier for request */
char handle[8]; /* older spelling of cookie */
};
__be64 from;
__be32 len;
} __attribute__((packed));
/*
* This is the reply packet that nbd-server sends back to the client after
* it has completed an I/O request (or an error occurs).
*/
struct nbd_reply {
__be32 magic; /* NBD_REPLY_MAGIC */
__be32 error; /* 0 = ok, else error */
union {
__be64 cookie; /* Opaque identifier from request */
char handle[8]; /* older spelling of cookie */
};
};
#endif /* LINUX_NBD_H */
All system for education purposes only. For more tools: Telegram @jackleet