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io: Add new qio_channel_read{, v}_all_eof functions
[mirror_qemu.git] / nbd / nbd-internal.h
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1/*
2 * NBD Internal Declarations
3 *
4 * Copyright (C) 2016 Red Hat, Inc.
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 */
9
10#ifndef NBD_INTERNAL_H
11#define NBD_INTERNAL_H
12#include "block/nbd.h"
13#include "sysemu/block-backend.h"
f95910fe 14#include "io/channel-tls.h"
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15
16#include "qemu/coroutine.h"
1c778ef7 17#include "qemu/iov.h"
798bfe00 18
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19#ifndef _WIN32
20#include <sys/ioctl.h>
21#endif
22#if defined(__sun__) || defined(__HAIKU__)
23#include <sys/ioccom.h>
24#endif
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25
26#ifdef __linux__
27#include <linux/fs.h>
28#endif
29
58369e22 30#include "qemu/bswap.h"
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31#include "qemu/queue.h"
32#include "qemu/main-loop.h"
33
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34/* This is all part of the "official" NBD API.
35 *
36 * The most up-to-date documentation is available at:
b626b51a 37 * https://github.com/yoe/nbd/blob/master/doc/proto.md
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38 */
39
8ecaeae8 40/* Size of all NBD_OPT_*, without payload */
5f66d060 41#define NBD_REQUEST_SIZE (4 + 2 + 2 + 8 + 8 + 4)
8ecaeae8 42/* Size of all NBD_REP_* sent in answer to most NBD_OPT_*, without payload */
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43#define NBD_REPLY_SIZE (4 + 4 + 8)
44/* Size of reply to NBD_OPT_EXPORT_NAME */
45#define NBD_REPLY_EXPORT_NAME_SIZE (8 + 2 + 124)
46/* Size of oldstyle negotiation */
47#define NBD_OLDSTYLE_NEGOTIATE_SIZE (8 + 8 + 8 + 4 + 124)
8ecaeae8 48
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49#define NBD_REQUEST_MAGIC 0x25609513
50#define NBD_REPLY_MAGIC 0x67446698
51#define NBD_OPTS_MAGIC 0x49484156454F5054LL
52#define NBD_CLIENT_MAGIC 0x0000420281861253LL
c8a3a1b6 53#define NBD_REP_MAGIC 0x0003e889045565a9LL
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54
55#define NBD_SET_SOCK _IO(0xab, 0)
56#define NBD_SET_BLKSIZE _IO(0xab, 1)
57#define NBD_SET_SIZE _IO(0xab, 2)
58#define NBD_DO_IT _IO(0xab, 3)
59#define NBD_CLEAR_SOCK _IO(0xab, 4)
60#define NBD_CLEAR_QUE _IO(0xab, 5)
61#define NBD_PRINT_DEBUG _IO(0xab, 6)
62#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
63#define NBD_DISCONNECT _IO(0xab, 8)
64#define NBD_SET_TIMEOUT _IO(0xab, 9)
65#define NBD_SET_FLAGS _IO(0xab, 10)
66
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67/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
68 * but only a limited set of errno values is specified in the protocol.
69 * Everything else is squashed to EINVAL.
70 */
71#define NBD_SUCCESS 0
72#define NBD_EPERM 1
73#define NBD_EIO 5
74#define NBD_ENOMEM 12
75#define NBD_EINVAL 22
76#define NBD_ENOSPC 28
b6f5d3b5 77#define NBD_ESHUTDOWN 108
798bfe00 78
d1fdf257 79/* nbd_read_eof
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80 * Tries to read @size bytes from @ioc.
81 * Returns 1 on success
82 * 0 on eof, when no data was read (errp is not set)
83 * negative errno on failure (errp is set)
f5d406fe 84 */
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85static inline int nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size,
86 Error **errp)
798bfe00 87{
1c778ef7 88 struct iovec iov = { .iov_base = buffer, .iov_len = size };
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89 ssize_t ret;
90
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91 /* Sockets are kept in blocking mode in the negotiation phase. After
92 * that, a non-readable socket simply means that another thread stole
93 * our request/reply. Synchronization is done with recv_coroutine, so
94 * that this is coroutine-safe.
95 */
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96
97 assert(size);
98
99 ret = nbd_rwv(ioc, &iov, 1, size, true, errp);
100 if (ret <= 0) {
101 return ret;
102 }
103
104 if (ret != size) {
105 error_setg(errp, "End of file");
106 return -EINVAL;
107 }
108
109 return 1;
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110}
111
d1fdf257 112/* nbd_read
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113 * Reads @size bytes from @ioc. Returns 0 on success.
114 */
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115static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,
116 Error **errp)
f5d406fe 117{
ab01df1f 118 int ret = nbd_read_eof(ioc, buffer, size, errp);
f5d406fe 119
ab01df1f 120 if (ret == 0) {
f5d406fe 121 ret = -EINVAL;
e44ed99d 122 error_setg(errp, "End of file");
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123 }
124
125 return ret < 0 ? ret : 0;
126}
127
d1fdf257 128/* nbd_write
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129 * Writes @size bytes to @ioc. Returns 0 on success.
130 */
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131static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size,
132 Error **errp)
798bfe00 133{
b1a75b33 134 struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size };
1c778ef7 135
d1fdf257 136 ssize_t ret = nbd_rwv(ioc, &iov, 1, size, false, errp);
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137
138 assert(ret < 0 || ret == size);
139
140 return ret < 0 ? ret : 0;
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141}
142
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143struct NBDTLSHandshakeData {
144 GMainLoop *loop;
145 bool complete;
146 Error *error;
147};
148
149
60e705c5 150void nbd_tls_handshake(QIOTask *task,
f95910fe 151 void *opaque);
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152const char *nbd_opt_lookup(uint32_t opt);
153const char *nbd_rep_lookup(uint32_t rep);
154const char *nbd_info_lookup(uint16_t info);
155const char *nbd_cmd_lookup(uint16_t info);
f95910fe 156
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157int nbd_drop(QIOChannel *ioc, size_t size, Error **errp);
158
798bfe00 159#endif