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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* istream.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "internal.h"
#include <string.h>
#include <stdlib.h>
typedef struct {
sqfs_u64 offset;
sqfs_u64 count;
} sparse_ent_t;
typedef struct {
istream_t base;
istream_t *parent;
char *filename;
sparse_ent_t *sparse;
size_t num_sparse;
sqfs_u64 record_size;
sqfs_u64 file_size;
sqfs_u64 offset;
size_t padding;
size_t last_chunk;
bool last_sparse;
sqfs_u8 buffer[4096];
} tar_istream_t;
static bool is_sparse_region(tar_istream_t *tar, sqfs_u64 *count)
{
size_t i;
*count = tar->file_size - tar->offset;
if (tar->num_sparse == 0)
return false;
for (i = 0; i < tar->num_sparse; ++i) {
if (tar->offset >= tar->sparse[i].offset) {
sqfs_u64 diff = tar->offset - tar->sparse[i].offset;
if (diff < tar->sparse[i].count) {
*count = tar->sparse[i].count - diff;
return false;
}
}
}
for (i = 0; i < tar->num_sparse; ++i) {
if (tar->offset < tar->sparse[i].offset) {
sqfs_u64 diff = tar->sparse[i].offset - tar->offset;
if (diff < *count)
*count = diff;
}
}
return true;
}
static int precache(istream_t *strm)
{
tar_istream_t *tar = (tar_istream_t *)strm;
sqfs_u64 diff, avail;
tar->offset += tar->last_chunk;
if (!tar->last_sparse) {
tar->parent->buffer_offset += tar->last_chunk;
tar->record_size -= tar->last_chunk;
}
if (tar->offset >= tar->file_size) {
strm->eof = true;
strm->buffer_used = 0;
strm->buffer = tar->buffer;
if (tar->record_size > 0)
goto fail_rec_sz;
if (istream_skip(tar->parent, tar->padding))
goto fail;
tar->padding = 0;
return 0;
}
if (is_sparse_region(tar, &diff)) {
if (diff > sizeof(tar->buffer))
diff = sizeof(tar->buffer);
strm->buffer = tar->buffer;
strm->buffer_used = diff;
tar->last_chunk = diff;
tar->last_sparse = true;
memset(tar->buffer, 0, diff);
} else {
if (diff > tar->record_size)
goto fail_rec_sz;
avail = tar->parent->buffer_used - tar->parent->buffer_offset;
if ((diff > avail) &&
((tar->parent->buffer_offset > 0) || avail == 0)) {
if (istream_precache(tar->parent))
goto fail;
if (tar->parent->buffer_used == 0 && tar->parent->eof)
goto fail_eof;
avail = tar->parent->buffer_used;
}
if (diff > avail)
diff = avail;
strm->buffer = tar->parent->buffer + tar->parent->buffer_offset;
strm->buffer_used = diff;
tar->last_chunk = diff;
tar->last_sparse = false;
}
return 0;
fail_rec_sz:
fprintf(stderr,
"%s: missmatch in tar record size vs file size for `%s`.\n",
istream_get_filename(tar->parent), istream_get_filename(strm));
goto fail;
fail_eof:
fprintf(stderr, "%s: unexpected end-of-file while reading `%s`\n",
istream_get_filename(tar->parent), istream_get_filename(strm));
goto fail;
fail:
tar->record_size = 0;
tar->padding = 0;
return -1;
}
static const char *get_filename(istream_t *strm)
{
return ((tar_istream_t *)strm)->filename;
}
static void tar_istream_destroy(sqfs_object_t *obj)
{
tar_istream_t *strm = (tar_istream_t *)obj;
if (strm->record_size > 0)
istream_skip(strm->parent, strm->record_size);
if (strm->padding > 0)
istream_skip(strm->parent, strm->padding);
sqfs_drop(strm->parent);
free(strm->sparse);
free(strm->filename);
free(strm);
}
istream_t *tar_record_istream_create(istream_t *parent,
const tar_header_decoded_t *hdr)
{
tar_istream_t *strm;
sparse_map_t *it;
sqfs_u64 diff;
size_t idx;
strm = calloc(1, sizeof(*strm));
if (strm == NULL)
goto fail_oom;
sqfs_object_init(strm, tar_istream_destroy, NULL);
strm->filename = strdup(hdr->name);
if (strm->filename == NULL)
goto fail_oom;
strm->num_sparse = 0;
for (it = hdr->sparse; it != NULL; it = it->next)
strm->num_sparse += 1;
if (strm->num_sparse > 0) {
strm->sparse = alloc_array(sizeof(strm->sparse[0]),
strm->num_sparse);
if (strm->sparse == NULL)
goto fail_oom;
idx = 0;
it = hdr->sparse;
while (it != NULL && idx < strm->num_sparse) {
strm->sparse[idx].offset = it->offset;
strm->sparse[idx].count = it->count;
++idx;
it = it->next;
}
}
for (idx = 1; idx < strm->num_sparse; ++idx) {
if (strm->sparse[idx].offset <= strm->sparse[idx - 1].offset)
goto fail_sparse;
diff = strm->sparse[idx].offset - strm->sparse[idx - 1].offset;
if (diff < strm->sparse[idx - 1].count)
goto fail_sparse;
}
strm->padding = hdr->record_size % 512;
if (strm->padding > 0)
strm->padding = 512 - strm->padding;
strm->record_size = hdr->record_size;
strm->file_size = hdr->actual_size;
strm->parent = sqfs_grab(parent);
((istream_t *)strm)->precache = precache;
((istream_t *)strm)->get_filename = get_filename;
((istream_t *)strm)->buffer = strm->buffer;
((istream_t *)strm)->eof = false;
return (istream_t *)strm;
fail_sparse:
fprintf(stderr, "%s: sparse map is not ordered or overlapping!\n",
hdr->name);
goto fail;
fail_oom:
fputs("tar istream create: out-of-memory\n", stderr);
goto fail;
fail:
if (strm != NULL) {
free(strm->filename);
free(strm);
}
return NULL;
}
|
