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
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* io_stdin.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "common.h"
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
typedef struct {
sqfs_file_t base;
const sparse_map_t *map;
sqfs_u64 offset;
sqfs_u64 size;
FILE *fp;
} sqfs_file_stdinout_t;
static void stdinout_destroy(sqfs_file_t *base)
{
free(base);
}
static sqfs_u64 stdinout_get_size(const sqfs_file_t *base)
{
return ((const sqfs_file_stdinout_t *)base)->size;
}
static int stdinout_truncate(sqfs_file_t *base, sqfs_u64 size)
{
(void)base; (void)size;
return SQFS_ERROR_IO;
}
static int stdin_read_at(sqfs_file_t *base, sqfs_u64 offset,
void *buffer, size_t size)
{
sqfs_file_stdinout_t *file = (sqfs_file_stdinout_t *)base;
size_t temp_size = 0;
sqfs_u8 *temp = NULL;
sqfs_u64 diff;
size_t ret;
if (offset < file->offset)
return SQFS_ERROR_IO;
if (offset > file->offset) {
temp_size = 1024;
temp = alloca(temp_size);
}
if (offset >= file->size || (offset + size) > file->size)
return SQFS_ERROR_OUT_OF_BOUNDS;
while (size > 0) {
if (ferror(file->fp))
return SQFS_ERROR_IO;
if (feof(file->fp))
return SQFS_ERROR_OUT_OF_BOUNDS;
if (offset > file->offset) {
diff = file->offset - offset;
diff = diff > (sqfs_u64)temp_size ? temp_size : diff;
ret = fread(temp, 1, diff, file->fp);
} else {
ret = fread(buffer, 1, size, file->fp);
}
if (offset <= file->offset) {
buffer = (char *)buffer + ret;
size -= ret;
offset += ret;
}
file->offset += ret;
}
return 0;
}
static int stdin_read_condensed(sqfs_file_t *base, sqfs_u64 offset,
void *buffer, size_t size)
{
sqfs_file_stdinout_t *file = (sqfs_file_stdinout_t *)base;
sqfs_u64 poffset = 0, src_start;
size_t dst_start, diff, count;
const sparse_map_t *it;
int err;
memset(buffer, 0, size);
for (it = file->map; it != NULL; it = it->next) {
if (it->offset + it->count <= offset) {
poffset += it->count;
continue;
}
if (it->offset >= offset + size) {
poffset += it->count;
continue;
}
count = size;
if (offset + count >= it->offset + it->count)
count = it->offset + it->count - offset;
if (it->offset < offset) {
diff = offset - it->offset;
src_start = poffset + diff;
dst_start = 0;
count -= diff;
} else if (it->offset > offset) {
diff = it->offset - offset;
src_start = poffset;
dst_start = diff;
} else {
src_start = poffset;
dst_start = 0;
}
err = stdin_read_at(base, src_start,
(char *)buffer + dst_start, count);
if (err)
return err;
poffset += it->count;
}
return 0;
}
static int stdin_write_at(sqfs_file_t *base, sqfs_u64 offset,
const void *buffer, size_t size)
{
(void)base; (void)offset; (void)buffer; (void)size;
return SQFS_ERROR_IO;
}
sqfs_file_t *sqfs_get_stdin_file(FILE *fp, const sparse_map_t *map,
sqfs_u64 size)
{
sqfs_file_stdinout_t *file = calloc(1, sizeof(*file));
sqfs_file_t *base = (sqfs_file_t *)file;
if (file == NULL)
return NULL;
file->size = size;
file->map = map;
file->fp = fp;
base->destroy = stdinout_destroy;
base->write_at = stdin_write_at;
base->get_size = stdinout_get_size;
base->truncate = stdinout_truncate;
if (map == NULL) {
base->read_at = stdin_read_at;
} else {
base->read_at = stdin_read_condensed;
}
return base;
}
|
