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
|
/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* io_file.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#define SQFS_BUILDING_DLL
#include "config.h"
#include "sqfs/io.h"
#include "sqfs/error.h"
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
typedef struct {
sqfs_file_t base;
uint64_t size;
int fd;
} sqfs_file_stdio_t;
static void stdio_destroy(sqfs_file_t *base)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
close(file->fd);
free(file);
}
static int stdio_read_at(sqfs_file_t *base, uint64_t offset,
void *buffer, size_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
ssize_t ret;
while (size > 0) {
ret = pread(file->fd, buffer, size, offset);
if (ret < 0) {
if (errno == EINTR)
continue;
return SQFS_ERROR_IO;
}
if (ret == 0)
return SQFS_ERROR_OUT_OF_BOUNDS;
buffer = (char *)buffer + ret;
size -= ret;
offset += ret;
}
return 0;
}
static int stdio_write_at(sqfs_file_t *base, uint64_t offset,
const void *buffer, size_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
ssize_t ret;
while (size > 0) {
ret = pwrite(file->fd, buffer, size, offset);
if (ret < 0) {
if (errno == EINTR)
continue;
return SQFS_ERROR_IO;
}
if (ret == 0)
return SQFS_ERROR_OUT_OF_BOUNDS;
buffer = (const char *)buffer + ret;
size -= ret;
offset += ret;
}
if (offset >= file->size)
file->size = offset;
return 0;
}
static uint64_t stdio_get_size(const sqfs_file_t *base)
{
const sqfs_file_stdio_t *file = (const sqfs_file_stdio_t *)base;
return file->size;
}
static int stdio_truncate(sqfs_file_t *base, uint64_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
if (ftruncate(file->fd, size))
return SQFS_ERROR_IO;
file->size = size;
return 0;
}
sqfs_file_t *sqfs_open_file(const char *filename, int flags)
{
sqfs_file_stdio_t *file;
int open_mode, temp;
sqfs_file_t *base;
struct stat sb;
if (flags & ~SQFS_FILE_OPEN_ALL_FLAGS) {
errno = EINVAL;
return NULL;
}
file = calloc(1, sizeof(*file));
base = (sqfs_file_t *)file;
if (file == NULL)
return NULL;
if (flags & SQFS_FILE_OPEN_READ_ONLY) {
open_mode = O_RDONLY;
} else {
open_mode = O_CREAT | O_RDWR;
if (flags & SQFS_FILE_OPEN_OVERWRITE) {
open_mode |= O_TRUNC;
} else {
open_mode |= O_EXCL;
}
}
file->fd = open(filename, open_mode, 0600);
if (file->fd < 0) {
temp = errno;
free(file);
errno = temp;
return NULL;
}
if (fstat(file->fd, &sb)) {
temp = errno;
close(file->fd);
free(file);
errno = temp;
return NULL;
}
file->size = sb.st_size;
base->destroy = stdio_destroy;
base->read_at = stdio_read_at;
base->write_at = stdio_write_at;
base->get_size = stdio_get_size;
base->truncate = stdio_truncate;
return base;
}
|
