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 */ 31 struct nbd_request { 32 uint64_t handle; 33 uint64_t from; 34 uint32_t len; 35 uint32_t type; 36 }; 37 38 struct 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 68 enum { 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 /* Maximum size of an export name. The NBD spec requires 256 and 81 * suggests that servers support up to 4096, but we stick to only the 82 * required size so that we can stack-allocate the names, and because 83 * going larger would require an audit of more code to make sure we 84 * aren't overflowing some other buffer. */ 85 #define NBD_MAX_NAME_SIZE 256 86 87 ssize_t nbd_wr_syncv(QIOChannel *ioc, 88 struct iovec *iov, 89 size_t niov, 90 size_t offset, 91 size_t length, 92 bool do_read); 93 int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, 94 QCryptoTLSCreds *tlscreds, const char *hostname, 95 QIOChannel **outioc, 96 off_t *size, Error **errp); 97 int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size); 98 ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request); 99 ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply); 100 int nbd_client(int fd); 101 int nbd_disconnect(int fd); 102 103 typedef struct NBDExport NBDExport; 104 typedef struct NBDClient NBDClient; 105 106 NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size, 107 uint32_t nbdflags, void (*close)(NBDExport *), 108 Error **errp); 109 void nbd_export_close(NBDExport *exp); 110 void nbd_export_get(NBDExport *exp); 111 void nbd_export_put(NBDExport *exp); 112 113 BlockBackend *nbd_export_get_blockdev(NBDExport *exp); 114 115 NBDExport *nbd_export_find(const char *name); 116 void nbd_export_set_name(NBDExport *exp, const char *name); 117 void nbd_export_close_all(void); 118 119 void nbd_client_new(NBDExport *exp, 120 QIOChannelSocket *sioc, 121 QCryptoTLSCreds *tlscreds, 122 const char *tlsaclname, 123 void (*close)(NBDClient *)); 124 void nbd_client_get(NBDClient *client); 125 void nbd_client_put(NBDClient *client); 126 127 #endif 128