1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* Copyright (C) 2016-2017 Red Hat, Inc.
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; under version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef NBD_H
#define NBD_H
#include "qemu-common.h"
#include "qemu/option.h"
#include "io/channel-socket.h"
#include "crypto/tlscreds.h"
/* Handshake phase structs - this struct is passed on the wire */
struct nbd_option {
uint64_t magic; /* NBD_OPTS_MAGIC */
uint32_t option; /* NBD_OPT_* */
uint32_t length;
} QEMU_PACKED;
typedef struct nbd_option nbd_option;
struct nbd_opt_reply {
uint64_t magic; /* NBD_REP_MAGIC */
uint32_t option; /* NBD_OPT_* */
uint32_t type; /* NBD_REP_* */
uint32_t length;
} QEMU_PACKED;
typedef struct nbd_opt_reply nbd_opt_reply;
/* Transmission phase structs
*
* Note: these are _NOT_ the same as the network representation of an NBD
* request and reply!
*/
struct NBDRequest {
uint64_t handle;
uint64_t from;
uint32_t len;
uint16_t flags; /* NBD_CMD_FLAG_* */
uint16_t type; /* NBD_CMD_* */
};
typedef struct NBDRequest NBDRequest;
struct NBDReply {
uint64_t handle;
uint32_t error;
};
typedef struct NBDReply NBDReply;
typedef struct NBDSimpleReply {
uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */
uint32_t error;
uint64_t handle;
} QEMU_PACKED NBDSimpleReply;
/* Transmission (export) flags: sent from server to client during handshake,
but describe what will happen during transmission */
#define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */
#define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */
#define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */
#define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */
#define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm -
rotational media */
#define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */
#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */
/* New-style handshake (global) flags, sent from server to client, and
control what will happen during handshake phase. */
#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
#define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
/* New-style client flags, sent from client to server to control what happens
during handshake phase. */
#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
#define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
/* Option requests. */
#define NBD_OPT_EXPORT_NAME (1)
#define NBD_OPT_ABORT (2)
#define NBD_OPT_LIST (3)
/* #define NBD_OPT_PEEK_EXPORT (4) not in use */
#define NBD_OPT_STARTTLS (5)
#define NBD_OPT_INFO (6)
#define NBD_OPT_GO (7)
#define NBD_OPT_STRUCTURED_REPLY (8)
/* Option reply types. */
#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) | (value))
#define NBD_REP_ACK (1) /* Data sending finished. */
#define NBD_REP_SERVER (2) /* Export description. */
#define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */
#define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */
#define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */
#define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */
#define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */
#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */
#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */
/* Info types, used during NBD_REP_INFO */
#define NBD_INFO_EXPORT 0
#define NBD_INFO_NAME 1
#define NBD_INFO_DESCRIPTION 2
#define NBD_INFO_BLOCK_SIZE 3
/* Request flags, sent from client to server during transmission phase */
#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
/* Supported request types */
enum {
NBD_CMD_READ = 0,
NBD_CMD_WRITE = 1,
NBD_CMD_DISC = 2,
NBD_CMD_FLUSH = 3,
NBD_CMD_TRIM = 4,
/* 5 reserved for failed experiment NBD_CMD_CACHE */
NBD_CMD_WRITE_ZEROES = 6,
};
#define NBD_DEFAULT_PORT 10809
/* Maximum size of a single READ/WRITE data buffer */
#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
/* Maximum size of an export name. The NBD spec requires 256 and
* suggests that servers support up to 4096, but we stick to only the
* required size so that we can stack-allocate the names, and because
* going larger would require an audit of more code to make sure we
* aren't overflowing some other buffer. */
#define NBD_MAX_NAME_SIZE 256
/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
* but only a limited set of errno values is specified in the protocol.
* Everything else is squashed to EINVAL.
*/
#define NBD_SUCCESS 0
#define NBD_EPERM 1
#define NBD_EIO 5
#define NBD_ENOMEM 12
#define NBD_EINVAL 22
#define NBD_ENOSPC 28
#define NBD_ESHUTDOWN 108
/* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */
struct NBDExportInfo {
/* Set by client before nbd_receive_negotiate() */
bool request_sizes;
/* Set by server results during nbd_receive_negotiate() */
uint64_t size;
uint16_t flags;
uint32_t min_block;
uint32_t opt_block;
uint32_t max_block;
};
typedef struct NBDExportInfo NBDExportInfo;
int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
QCryptoTLSCreds *tlscreds, const char *hostname,
QIOChannel **outioc, NBDExportInfo *info,
Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp);
int nbd_client(int fd);
int nbd_disconnect(int fd);
int nbd_errno_to_system_errno(int err);
typedef struct NBDExport NBDExport;
typedef struct NBDClient NBDClient;
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
uint16_t nbdflags, void (*close)(NBDExport *),
bool writethrough, BlockBackend *on_eject_blk,
Error **errp);
void nbd_export_close(NBDExport *exp);
void nbd_export_get(NBDExport *exp);
void nbd_export_put(NBDExport *exp);
BlockBackend *nbd_export_get_blockdev(NBDExport *exp);
NBDExport *nbd_export_find(const char *name);
void nbd_export_set_name(NBDExport *exp, const char *name);
void nbd_export_set_description(NBDExport *exp, const char *description);
void nbd_export_close_all(void);
void nbd_client_new(NBDExport *exp,
QIOChannelSocket *sioc,
QCryptoTLSCreds *tlscreds,
const char *tlsaclname,
void (*close_fn)(NBDClient *, bool));
void nbd_client_get(NBDClient *client);
void nbd_client_put(NBDClient *client);
void nbd_server_start(SocketAddress *addr, const char *tls_creds,
Error **errp);
#endif
|