nbd.h

   1 /*
   2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
   3  *
   4  *  Network Block Device
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; under version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef NBD_H
  20 #define NBD_H
  21
  22 #include <sys/types.h>
  23
  24 #include "qemu-common.h"
  25
  26 struct nbd_request {
  27     uint32_t magic;
  28     uint32_t type;
  29     uint64_t handle;
  30     uint64_t from;
  31     uint32_t len;
  32 } QEMU_PACKED;
  33
  34 struct nbd_reply {
  35     uint32_t magic;
  36     uint32_t error;
  37     uint64_t handle;
  38 } QEMU_PACKED;
  39
  40 #define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
  41 #define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
  42 #define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
  43 #define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
  44 #define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
  45 #define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
  46
  47 #define NBD_CMD_MASK_COMMAND    0x0000ffff
  48 #define NBD_CMD_FLAG_FUA        (1 << 16)
  49
  50 enum {
  51     NBD_CMD_READ = 0,
  52     NBD_CMD_WRITE = 1,
  53     NBD_CMD_DISC = 2,
  54     NBD_CMD_FLUSH = 3,
  55     NBD_CMD_TRIM = 4
  56 };
  57
  58 #define NBD_DEFAULT_PORT        10809
  59
  60 #define NBD_BUFFER_SIZE (1024*1024)
  61
  62 ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
  63 int tcp_socket_outgoing(const char *address, uint16_t port);
  64 int tcp_socket_incoming(const char *address, uint16_t port);
  65 int tcp_socket_outgoing_spec(const char *address_and_port);
  66 int tcp_socket_incoming_spec(const char *address_and_port);
  67 int unix_socket_outgoing(const char *path);
  68 int unix_socket_incoming(const char *path);
  69
  70 int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
  71                           off_t *size, size_t *blocksize);
  72 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize);
  73 ssize_t nbd_send_request(int csock, struct nbd_request *request);
  74 ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply);
  75 int nbd_client(int fd);
  76 int nbd_disconnect(int fd);
  77
  78 typedef struct NBDExport NBDExport;
  79 typedef struct NBDClient NBDClient;
  80
  81 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
  82                           off_t size, uint32_t nbdflags);
  83 void nbd_export_close(NBDExport *exp);
  84 NBDClient *nbd_client_new(NBDExport *exp, int csock,
  85                           void (*close)(NBDClient *));
  86
  87 #endif