qemu/nbd.h
Paolo Bonzini 185b43386a nbd: consistently return negative errno values
In the next patch we need to look at the return code of nbd_wr_sync.
To avoid percolating the socket_error() ugliness all around, let's
handle errors by returning negative errno values.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 16:36:43 +02:00

87 lines
2.8 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"
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) */
#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
#define NBD_BUFFER_SIZE (1024*1024)
ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int tcp_socket_outgoing(const char *address, uint16_t port);
int tcp_socket_incoming(const char *address, uint16_t port);
int tcp_socket_outgoing_spec(const char *address_and_port);
int tcp_socket_incoming_spec(const char *address_and_port);
int unix_socket_outgoing(const char *path);
int unix_socket_incoming(const char *path);
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
off_t *size, size_t *blocksize);
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(BlockDriverState *bs, off_t dev_offset,
off_t size, uint32_t nbdflags);
void nbd_export_close(NBDExport *exp);
NBDClient *nbd_client_new(NBDExport *exp, int csock,
void (*close)(NBDClient *));
#endif