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
|
/*
FUSE fioc: FUSE ioctl example
Copyright (C) 2008 SUSE Linux Products GmbH
Copyright (C) 2008 Tejun Heo <teheo@suse.de>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
gcc -Wall fioc.c `pkg-config fuse --cflags --libs` -o fioc
*/
#define FUSE_USE_VERSION 26
#include <fuse.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>
#include "fioc.h"
#define FIOC_NAME "fioc"
enum {
FIOC_NONE,
FIOC_ROOT,
FIOC_FILE,
};
static void *fioc_buf;
static size_t fioc_size;
static int fioc_resize(size_t new_size)
{
void *new_buf;
if (new_size == fioc_size)
return 0;
new_buf = realloc(fioc_buf, new_size);
if (!new_buf && new_size)
return -ENOMEM;
if (new_size > fioc_size)
memset(new_buf + fioc_size, 0, new_size - fioc_size);
fioc_buf = new_buf;
fioc_size = new_size;
return 0;
}
static int fioc_expand(size_t new_size)
{
if (new_size > fioc_size)
return fioc_resize(new_size);
return 0;
}
static int fioc_file_type(const char *path)
{
if (strcmp(path, "/") == 0)
return FIOC_ROOT;
if (strcmp(path, "/" FIOC_NAME) == 0)
return FIOC_FILE;
return FIOC_NONE;
}
static int fioc_getattr(const char *path, struct stat *stbuf)
{
stbuf->st_uid = getuid();
stbuf->st_gid = getgid();
stbuf->st_atime = stbuf->st_mtime = time(NULL);
switch (fioc_file_type(path)) {
case FIOC_ROOT:
stbuf->st_mode = S_IFDIR | 0755;
stbuf->st_nlink = 2;
break;
case FIOC_FILE:
stbuf->st_mode = S_IFREG | 0644;
stbuf->st_nlink = 1;
stbuf->st_size = fioc_size;
break;
case FIOC_NONE:
return -ENOENT;
}
return 0;
}
static int fioc_open(const char *path, struct fuse_file_info *fi)
{
(void) fi;
if (fioc_file_type(path) != FIOC_NONE)
return 0;
return -ENOENT;
}
static int fioc_do_read(char *buf, size_t size, off_t offset)
{
if (offset >= fioc_size)
return 0;
if (size > fioc_size - offset)
size = fioc_size - offset;
memcpy(buf, fioc_buf + offset, size);
return size;
}
static int fioc_read(const char *path, char *buf, size_t size,
off_t offset, struct fuse_file_info *fi)
{
(void) fi;
if (fioc_file_type(path) != FIOC_FILE)
return -EINVAL;
return fioc_do_read(buf, size, offset);
}
static int fioc_do_write(const char *buf, size_t size, off_t offset)
{
if (fioc_expand(offset + size))
return -ENOMEM;
memcpy(fioc_buf + offset, buf, size);
return size;
}
static int fioc_write(const char *path, const char *buf, size_t size,
off_t offset, struct fuse_file_info *fi)
{
(void) fi;
if (fioc_file_type(path) != FIOC_FILE)
return -EINVAL;
return fioc_do_write(buf, size, offset);
}
static int fioc_truncate(const char *path, off_t size)
{
if (fioc_file_type(path) != FIOC_FILE)
return -EINVAL;
return fioc_resize(size);
}
static int fioc_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
off_t offset, struct fuse_file_info *fi)
{
(void) fi;
(void) offset;
if (fioc_file_type(path) != FIOC_ROOT)
return -ENOENT;
filler(buf, ".", NULL, 0);
filler(buf, "..", NULL, 0);
filler(buf, FIOC_NAME, NULL, 0);
return 0;
}
static int fioc_ioctl(const char *path, int cmd, void *arg,
struct fuse_file_info *fi, unsigned int flags, void *data)
{
(void) arg;
(void) fi;
(void) flags;
if (fioc_file_type(path) != FIOC_FILE)
return -EINVAL;
if (flags & FUSE_IOCTL_COMPAT)
return -ENOSYS;
switch (cmd) {
case FIOC_GET_SIZE:
*(size_t *)data = fioc_size;
return 0;
case FIOC_SET_SIZE:
fioc_resize(*(size_t *)data);
return 0;
}
return -EINVAL;
}
static struct fuse_operations fioc_oper = {
.getattr = fioc_getattr,
.readdir = fioc_readdir,
.truncate = fioc_truncate,
.open = fioc_open,
.read = fioc_read,
.write = fioc_write,
.ioctl = fioc_ioctl,
};
int main(int argc, char *argv[])
{
return fuse_main(argc, argv, &fioc_oper, NULL);
}
|
