xref: /openbmc/qemu/nbd/nbd-internal.h (revision a8583393)
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 #include "io/channel-tls.h"
15 
16 #include "qemu/coroutine.h"
17 #include "qemu/iov.h"
18 
19 #ifndef _WIN32
20 #include <sys/ioctl.h>
21 #endif
22 #if defined(__sun__) || defined(__HAIKU__)
23 #include <sys/ioccom.h>
24 #endif
25 
26 #ifdef __linux__
27 #include <linux/fs.h>
28 #endif
29 
30 #include "qemu/bswap.h"
31 #include "qemu/queue.h"
32 #include "qemu/main-loop.h"
33 
34 /* This is all part of the "official" NBD API.
35  *
36  * The most up-to-date documentation is available at:
37  * https://github.com/yoe/nbd/blob/master/doc/proto.md
38  */
39 
40 /* Size of all NBD_OPT_*, without payload */
41 #define NBD_REQUEST_SIZE            (4 + 2 + 2 + 8 + 8 + 4)
42 /* Size of all NBD_REP_* sent in answer to most NBD_OPT_*, without payload */
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)
48 
49 #define NBD_REQUEST_MAGIC       0x25609513
50 #define NBD_REPLY_MAGIC         0x67446698
51 #define NBD_OPTS_MAGIC          0x49484156454F5054LL
52 #define NBD_CLIENT_MAGIC        0x0000420281861253LL
53 #define NBD_REP_MAGIC           0x0003e889045565a9LL
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 
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
77 #define NBD_ESHUTDOWN  108
78 
79 /* nbd_read_eof
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)
84  */
85 static inline int nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size,
86                                Error **errp)
87 {
88     int ret;
89 
90     assert(size);
91     ret = qio_channel_read_all_eof(ioc, buffer, size, errp);
92     if (ret < 0) {
93         ret = -EIO;
94     }
95     return ret;
96 }
97 
98 /* nbd_read
99  * Reads @size bytes from @ioc. Returns 0 on success.
100  */
101 static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,
102                            Error **errp)
103 {
104     return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
105 }
106 
107 /* nbd_write
108  * Writes @size bytes to @ioc. Returns 0 on success.
109  */
110 static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size,
111                             Error **errp)
112 {
113     return qio_channel_write_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
114 }
115 
116 struct NBDTLSHandshakeData {
117     GMainLoop *loop;
118     bool complete;
119     Error *error;
120 };
121 
122 
123 void nbd_tls_handshake(QIOTask *task,
124                        void *opaque);
125 const char *nbd_opt_lookup(uint32_t opt);
126 const char *nbd_rep_lookup(uint32_t rep);
127 const char *nbd_info_lookup(uint16_t info);
128 const char *nbd_cmd_lookup(uint16_t info);
129 
130 int nbd_drop(QIOChannel *ioc, size_t size, Error **errp);
131 
132 #endif
133