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 #include "qemu/option.h" 26 27 struct nbd_request { 28 uint32_t magic; 29 uint32_t type; 30 uint64_t handle; 31 uint64_t from; 32 uint32_t len; 33 } QEMU_PACKED; 34 35 struct nbd_reply { 36 uint32_t magic; 37 uint32_t error; 38 uint64_t handle; 39 } QEMU_PACKED; 40 41 #define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */ 42 #define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */ 43 #define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */ 44 #define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */ 45 #define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */ 46 #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ 47 48 #define NBD_CMD_MASK_COMMAND 0x0000ffff 49 #define NBD_CMD_FLAG_FUA (1 << 16) 50 51 enum { 52 NBD_CMD_READ = 0, 53 NBD_CMD_WRITE = 1, 54 NBD_CMD_DISC = 2, 55 NBD_CMD_FLUSH = 3, 56 NBD_CMD_TRIM = 4 57 }; 58 59 #define NBD_DEFAULT_PORT 10809 60 61 /* Maximum size of a single READ/WRITE data buffer */ 62 #define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024) 63 64 ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read); 65 int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, 66 off_t *size, size_t *blocksize); 67 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize); 68 ssize_t nbd_send_request(int csock, struct nbd_request *request); 69 ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply); 70 int nbd_client(int fd); 71 int nbd_disconnect(int fd); 72 73 typedef struct NBDExport NBDExport; 74 typedef struct NBDClient NBDClient; 75 76 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, 77 off_t size, uint32_t nbdflags, 78 void (*close)(NBDExport *)); 79 void nbd_export_close(NBDExport *exp); 80 void nbd_export_get(NBDExport *exp); 81 void nbd_export_put(NBDExport *exp); 82 83 BlockDriverState *nbd_export_get_blockdev(NBDExport *exp); 84 85 NBDExport *nbd_export_find(const char *name); 86 void nbd_export_set_name(NBDExport *exp, const char *name); 87 void nbd_export_close_all(void); 88 89 NBDClient *nbd_client_new(NBDExport *exp, int csock, 90 void (*close)(NBDClient *)); 91 void nbd_client_close(NBDClient *client); 92 void nbd_client_get(NBDClient *client); 93 void nbd_client_put(NBDClient *client); 94 95 #endif 96