qemu-e2k/include/block/nbd.h
Max Reitz 1ce52846d3 nbd: Improve error messages
This patch makes use of the Error object for nbd_receive_negotiate() so
that errors during negotiation look nicer.

Furthermore, this patch adds an additional error message if the received
magic was wrong, but would be correct for the other protocol version,
respectively: So if an export name was specified, but the NBD server
magic corresponds to an old handshake, this condition is explicitly
signaled to the user, and vice versa.

As these messages are now part of the "Could not open image" error
message, additional filtering has to be employed in iotest 083, which
this patch does as well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06 17:24:22 +01:00

107 lines
3.5 KiB
C

/*
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
*
* 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; under version 2 of the License.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef NBD_H
#define NBD_H
#include <sys/types.h>
#include "qemu-common.h"
#include "qemu/option.h"
struct nbd_request {
uint32_t magic;
uint32_t type;
uint64_t handle;
uint64_t from;
uint32_t len;
} QEMU_PACKED;
struct nbd_reply {
uint32_t magic;
uint32_t error;
uint64_t handle;
} QEMU_PACKED;
#define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */
#define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */
#define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */
#define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */
#define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */
#define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */
/* New-style global flags. */
#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
/* New-style client flags. */
#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
/* Reply types. */
#define NBD_REP_ACK (1) /* Data sending finished. */
#define NBD_REP_SERVER (2) /* Export description. */
#define NBD_REP_ERR_UNSUP ((1 << 31) | 1) /* Unknown option. */
#define NBD_REP_ERR_INVALID ((1 << 31) | 3) /* Invalid length. */
#define NBD_CMD_MASK_COMMAND 0x0000ffff
#define NBD_CMD_FLAG_FUA (1 << 16)
enum {
NBD_CMD_READ = 0,
NBD_CMD_WRITE = 1,
NBD_CMD_DISC = 2,
NBD_CMD_FLUSH = 3,
NBD_CMD_TRIM = 4
};
#define NBD_DEFAULT_PORT 10809
/* Maximum size of a single READ/WRITE data buffer */
#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
off_t *size, size_t *blocksize, Error **errp);
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize);
ssize_t nbd_send_request(int csock, struct nbd_request *request);
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply);
int nbd_client(int fd);
int nbd_disconnect(int fd);
typedef struct NBDExport NBDExport;
typedef struct NBDClient NBDClient;
NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
uint32_t nbdflags, void (*close)(NBDExport *));
void nbd_export_close(NBDExport *exp);
void nbd_export_get(NBDExport *exp);
void nbd_export_put(NBDExport *exp);
BlockBackend *nbd_export_get_blockdev(NBDExport *exp);
NBDExport *nbd_export_find(const char *name);
void nbd_export_set_name(NBDExport *exp, const char *name);
void nbd_export_close_all(void);
NBDClient *nbd_client_new(NBDExport *exp, int csock,
void (*close)(NBDClient *));
void nbd_client_close(NBDClient *client);
void nbd_client_get(NBDClient *client);
void nbd_client_put(NBDClient *client);
#endif