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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"
14
15#include "qemu/coroutine.h"
16
17#include <errno.h>
18#include <string.h>
19#ifndef _WIN32
20#include <sys/ioctl.h>
21#endif
22#if defined(__sun__) || defined(__HAIKU__)
23#include <sys/ioccom.h>
24#endif
25#include <ctype.h>
26#include <inttypes.h>
27
28#ifdef __linux__
29#include <linux/fs.h>
30#endif
31
32#include "qemu/sockets.h"
33#include "qemu/queue.h"
34#include "qemu/main-loop.h"
35
36/* #define DEBUG_NBD */
37
38#ifdef DEBUG_NBD
39#define TRACE(msg, ...) do { \
40 LOG(msg, ## __VA_ARGS__); \
41} while(0)
42#else
43#define TRACE(msg, ...) \
44 do { } while (0)
45#endif
46
47#define LOG(msg, ...) do { \
48 fprintf(stderr, "%s:%s():L%d: " msg "\n", \
49 __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
50} while(0)
51
52/* This is all part of the "official" NBD API.
53 *
54 * The most up-to-date documentation is available at:
55 * https://github.com/yoe/nbd/blob/master/doc/proto.txt
56 */
57
58#define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4)
59#define NBD_REPLY_SIZE (4 + 4 + 8)
60#define NBD_REQUEST_MAGIC 0x25609513
61#define NBD_REPLY_MAGIC 0x67446698
62#define NBD_OPTS_MAGIC 0x49484156454F5054LL
63#define NBD_CLIENT_MAGIC 0x0000420281861253LL
64#define NBD_REP_MAGIC 0x3e889045565a9LL
65
66#define NBD_SET_SOCK _IO(0xab, 0)
67#define NBD_SET_BLKSIZE _IO(0xab, 1)
68#define NBD_SET_SIZE _IO(0xab, 2)
69#define NBD_DO_IT _IO(0xab, 3)
70#define NBD_CLEAR_SOCK _IO(0xab, 4)
71#define NBD_CLEAR_QUE _IO(0xab, 5)
72#define NBD_PRINT_DEBUG _IO(0xab, 6)
73#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
74#define NBD_DISCONNECT _IO(0xab, 8)
75#define NBD_SET_TIMEOUT _IO(0xab, 9)
76#define NBD_SET_FLAGS _IO(0xab, 10)
77
78#define NBD_OPT_EXPORT_NAME (1)
79#define NBD_OPT_ABORT (2)
80#define NBD_OPT_LIST (3)
81
82/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
83 * but only a limited set of errno values is specified in the protocol.
84 * Everything else is squashed to EINVAL.
85 */
86#define NBD_SUCCESS 0
87#define NBD_EPERM 1
88#define NBD_EIO 5
89#define NBD_ENOMEM 12
90#define NBD_EINVAL 22
91#define NBD_ENOSPC 28
92
93static inline ssize_t read_sync(int fd, void *buffer, size_t size)
94{
95 /* Sockets are kept in blocking mode in the negotiation phase. After
96 * that, a non-readable socket simply means that another thread stole
97 * our request/reply. Synchronization is done with recv_coroutine, so
98 * that this is coroutine-safe.
99 */
100 return nbd_wr_sync(fd, buffer, size, true);
101}
102
103static inline ssize_t write_sync(int fd, void *buffer, size_t size)
104{
105 int ret;
106 do {
107 /* For writes, we do expect the socket to be writable. */
108 ret = nbd_wr_sync(fd, buffer, size, false);
109 } while (ret == -EAGAIN);
110 return ret;
111}
112
113#endif