LXR qemu/include/block/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
  23#include "qemu-common.h"
  24#include "qemu/option.h"
  25#include "io/channel-socket.h"
  26#include "crypto/tlscreds.h"
  27
  28/* Note: these are _NOT_ the same as the network representation of an NBD
  29 * request and reply!
  30 */
  31struct nbd_request {
  32    uint64_t handle;
  33    uint64_t from;
  34    uint32_t len;
  35    uint32_t type;
  36};
  37
  38struct nbd_reply {
  39    uint64_t handle;
  40    uint32_t error;
  41};
  42
  43#define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
  44#define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
  45#define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
  46#define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
  47#define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
  48#define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
  49
  50/* New-style global flags. */
  51#define NBD_FLAG_FIXED_NEWSTYLE     (1 << 0)    /* Fixed newstyle protocol. */
  52
  53/* New-style client flags. */
  54#define NBD_FLAG_C_FIXED_NEWSTYLE   (1 << 0)    /* Fixed newstyle protocol. */
  55
  56/* Reply types. */
  57#define NBD_REP_ACK             (1)             /* Data sending finished. */
  58#define NBD_REP_SERVER          (2)             /* Export description. */
  59#define NBD_REP_ERR_UNSUP       ((UINT32_C(1) << 31) | 1) /* Unknown option. */
  60#define NBD_REP_ERR_POLICY      ((UINT32_C(1) << 31) | 2) /* Server denied */
  61#define NBD_REP_ERR_INVALID     ((UINT32_C(1) << 31) | 3) /* Invalid length. */
  62#define NBD_REP_ERR_TLS_REQD    ((UINT32_C(1) << 31) | 5) /* TLS required */
  63
  64
  65#define NBD_CMD_MASK_COMMAND    0x0000ffff
  66#define NBD_CMD_FLAG_FUA        (1 << 16)
  67
  68enum {
  69    NBD_CMD_READ = 0,
  70    NBD_CMD_WRITE = 1,
  71    NBD_CMD_DISC = 2,
  72    NBD_CMD_FLUSH = 3,
  73    NBD_CMD_TRIM = 4
  74};
  75
  76#define NBD_DEFAULT_PORT        10809
  77
  78/* Maximum size of a single READ/WRITE data buffer */
  79#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
  80
  81/* Maximum size of an export name. The NBD spec requires 256 and
  82 * suggests that servers support up to 4096, but we stick to only the
  83 * required size so that we can stack-allocate the names, and because
  84 * going larger would require an audit of more code to make sure we
  85 * aren't overflowing some other buffer. */
  86#define NBD_MAX_NAME_SIZE 256
  87
  88ssize_t nbd_wr_syncv(QIOChannel *ioc,
  89                     struct iovec *iov,
  90                     size_t niov,
  91                     size_t length,
  92                     bool do_read);
  93int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
  94                          QCryptoTLSCreds *tlscreds, const char *hostname,
  95                          QIOChannel **outioc,
  96                          off_t *size, Error **errp);
  97int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size);
  98ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request);
  99ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply);
 100int nbd_client(int fd);
 101int nbd_disconnect(int fd);
 102
 103typedef struct NBDExport NBDExport;
 104typedef struct NBDClient NBDClient;
 105
 106NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
 107                          uint16_t nbdflags, void (*close)(NBDExport *),
 108                          Error **errp);
 109void nbd_export_close(NBDExport *exp);
 110void nbd_export_get(NBDExport *exp);
 111void nbd_export_put(NBDExport *exp);
 112
 113BlockBackend *nbd_export_get_blockdev(NBDExport *exp);
 114
 115NBDExport *nbd_export_find(const char *name);
 116void nbd_export_set_name(NBDExport *exp, const char *name);
 117void nbd_export_close_all(void);
 118
 119void nbd_client_new(NBDExport *exp,
 120                    QIOChannelSocket *sioc,
 121                    QCryptoTLSCreds *tlscreds,
 122                    const char *tlsaclname,
 123                    void (*close)(NBDClient *));
 124void nbd_client_get(NBDClient *client);
 125void nbd_client_put(NBDClient *client);
 126
 127#endif
 128