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 struct nbd_request { 29 uint32_t magic; 30 uint32_t type; 31 uint64_t handle; 32 uint64_t from; 33 uint32_t len; 34 } QEMU_PACKED; 35 36 struct nbd_reply { 37 uint32_t magic; 38 uint32_t error; 39 uint64_t handle; 40 } QEMU_PACKED; 41 42 #define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */ 43 #define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */ 44 #define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */ 45 #define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */ 46 #define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */ 47 #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ 48 49 /* New-style global flags. */ 50 #define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ 51 52 /* New-style client flags. */ 53 #define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ 54 55 /* Reply types. */ 56 #define NBD_REP_ACK (1) /* Data sending finished. */ 57 #define NBD_REP_SERVER (2) /* Export description. */ 58 #define NBD_REP_ERR_UNSUP ((UINT32_C(1) << 31) | 1) /* Unknown option. */ 59 #define NBD_REP_ERR_POLICY ((UINT32_C(1) << 31) | 2) /* Server denied */ 60 #define NBD_REP_ERR_INVALID ((UINT32_C(1) << 31) | 3) /* Invalid length. */ 61 #define NBD_REP_ERR_TLS_REQD ((UINT32_C(1) << 31) | 5) /* TLS required */ 62 63 64 #define NBD_CMD_MASK_COMMAND 0x0000ffff 65 #define NBD_CMD_FLAG_FUA (1 << 16) 66 67 enum { 68 NBD_CMD_READ = 0, 69 NBD_CMD_WRITE = 1, 70 NBD_CMD_DISC = 2, 71 NBD_CMD_FLUSH = 3, 72 NBD_CMD_TRIM = 4 73 }; 74 75 #define NBD_DEFAULT_PORT 10809 76 77 /* Maximum size of a single READ/WRITE data buffer */ 78 #define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024) 79 80 ssize_t nbd_wr_syncv(QIOChannel *ioc, 81 struct iovec *iov, 82 size_t niov, 83 size_t offset, 84 size_t length, 85 bool do_read); 86 int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, 87 QCryptoTLSCreds *tlscreds, const char *hostname, 88 QIOChannel **outioc, 89 off_t *size, Error **errp); 90 int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size); 91 ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request); 92 ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply); 93 int nbd_client(int fd); 94 int nbd_disconnect(int fd); 95 96 typedef struct NBDExport NBDExport; 97 typedef struct NBDClient NBDClient; 98 99 NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size, 100 uint32_t nbdflags, void (*close)(NBDExport *), 101 Error **errp); 102 void nbd_export_close(NBDExport *exp); 103 void nbd_export_get(NBDExport *exp); 104 void nbd_export_put(NBDExport *exp); 105 106 BlockBackend *nbd_export_get_blockdev(NBDExport *exp); 107 108 NBDExport *nbd_export_find(const char *name); 109 void nbd_export_set_name(NBDExport *exp, const char *name); 110 void nbd_export_close_all(void); 111 112 void nbd_client_new(NBDExport *exp, 113 QIOChannelSocket *sioc, 114 QCryptoTLSCreds *tlscreds, 115 const char *tlsaclname, 116 void (*close)(NBDClient *)); 117 void nbd_client_get(NBDClient *client); 118 void nbd_client_put(NBDClient *client); 119 120 #endif 121