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1/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */2/*3 * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.4 * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)5 * Made nbd_end_request() use the io_request_lock6 * 2001 Copyright (C) Steven Whitehouse7 * New nbd_end_request() for compatibility with new linux block8 * layer code.9 * 2003/06/24 Louis D. Langholtz <ldl@aros.net>10 * Removed unneeded blksize_bits field from nbd_device struct.11 * Cleanup PARANOIA usage & code.12 * 2004/02/19 Paul Clements13 * Removed PARANOIA, plus various cleanup and comments14 * 2023 Copyright Red Hat15 * Link to userspace extensions, favor cookie over handle.16 */17 18#ifndef _UAPILINUX_NBD_H19#define _UAPILINUX_NBD_H20 21#include <linux/types.h>22 23#define NBD_SET_SOCK _IO( 0xab, 0 )24#define NBD_SET_BLKSIZE _IO( 0xab, 1 )25#define NBD_SET_SIZE _IO( 0xab, 2 )26#define NBD_DO_IT _IO( 0xab, 3 )27#define NBD_CLEAR_SOCK _IO( 0xab, 4 )28#define NBD_CLEAR_QUE _IO( 0xab, 5 )29#define NBD_PRINT_DEBUG _IO( 0xab, 6 )30#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )31#define NBD_DISCONNECT _IO( 0xab, 8 )32#define NBD_SET_TIMEOUT _IO( 0xab, 9 )33#define NBD_SET_FLAGS _IO( 0xab, 10)34 35/*36 * See also https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md37 * for additional userspace extensions not yet utilized in the kernel module.38 */39 40enum {41 NBD_CMD_READ = 0,42 NBD_CMD_WRITE = 1,43 NBD_CMD_DISC = 2,44 NBD_CMD_FLUSH = 3,45 NBD_CMD_TRIM = 4,46 /* userspace defines additional extension commands */47 NBD_CMD_WRITE_ZEROES = 6,48};49 50/* values for flags field, these are server interaction specific. */51#define NBD_FLAG_HAS_FLAGS (1 << 0) /* nbd-server supports flags */52#define NBD_FLAG_READ_ONLY (1 << 1) /* device is read-only */53#define NBD_FLAG_SEND_FLUSH (1 << 2) /* can flush writeback cache */54#define NBD_FLAG_SEND_FUA (1 << 3) /* send FUA (forced unit access) */55#define NBD_FLAG_ROTATIONAL (1 << 4) /* device is rotational */56#define NBD_FLAG_SEND_TRIM (1 << 5) /* send trim/discard */57#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* supports WRITE_ZEROES */58/* there is a gap here to match userspace */59#define NBD_FLAG_CAN_MULTI_CONN (1 << 8) /* Server supports multiple connections per export. */60 61/* values for cmd flags in the upper 16 bits of request type */62#define NBD_CMD_FLAG_FUA (1 << 16) /* FUA (forced unit access) op */63#define NBD_CMD_FLAG_NO_HOLE (1 << 17) /* Do not punch a hole for WRITE_ZEROES */64 65/* These are client behavior specific flags. */66#define NBD_CFLAG_DESTROY_ON_DISCONNECT (1 << 0) /* delete the nbd device on67 disconnect. */68#define NBD_CFLAG_DISCONNECT_ON_CLOSE (1 << 1) /* disconnect the nbd device on69 * close by last opener.70 */71 72/* userspace doesn't need the nbd_device structure */73 74/* These are sent over the network in the request/reply magic fields */75 76#define NBD_REQUEST_MAGIC 0x2560951377#define NBD_REPLY_MAGIC 0x6744669878/* Do *not* use magics: 0x12560953 0x96744668. */79/* magic 0x668e33ef for structured reply not supported by kernel yet */80 81/*82 * This is the packet used for communication between client and83 * server. All data are in network byte order.84 */85struct nbd_request {86 __be32 magic; /* NBD_REQUEST_MAGIC */87 __be32 type; /* See NBD_CMD_* */88 union {89 __be64 cookie; /* Opaque identifier for request */90 char handle[8]; /* older spelling of cookie */91 };92 __be64 from;93 __be32 len;94} __attribute__((packed));95 96/*97 * This is the reply packet that nbd-server sends back to the client after98 * it has completed an I/O request (or an error occurs).99 */100struct nbd_reply {101 __be32 magic; /* NBD_REPLY_MAGIC */102 __be32 error; /* 0 = ok, else error */103 union {104 __be64 cookie; /* Opaque identifier from request */105 char handle[8]; /* older spelling of cookie */106 };107};108#endif /* _UAPILINUX_NBD_H */109