57cea04f1ae96442be014cfa8f9559924be01ecc
[wimlib] / src / header.c
1 /*
2  * header.c
3  *
4  * Read, write, or create a WIM header.
5  */
6
7 /*
8  * Copyright (C) 2012, 2013 Eric Biggers
9  *
10  * This file is part of wimlib, a library for working with WIM files.
11  *
12  * wimlib is free software; you can redistribute it and/or modify it under the
13  * terms of the GNU General Public License as published by the Free
14  * Software Foundation; either version 3 of the License, or (at your option)
15  * any later version.
16  *
17  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
18  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
19  * A PARTICULAR PURPOSE. See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with wimlib; if not, see http://www.gnu.org/licenses/.
24  */
25
26 #ifdef HAVE_CONFIG_H
27 #  include "config.h"
28 #endif
29
30 #include "wimlib.h"
31 #include "wimlib/assert.h"
32 #include "wimlib/endianness.h"
33 #include "wimlib/error.h"
34 #include "wimlib/file_io.h"
35 #include "wimlib/header.h"
36 #include "wimlib/util.h"
37 #include "wimlib/wim.h"
38
39 #include <limits.h>
40 #include <string.h>
41 #include <unistd.h>
42 #ifdef HAVE_ALLOCA_H
43 #  include <alloca.h>
44 #else
45 #  include <stdlib.h>
46 #endif
47
48 /*
49  * Reads the header from a WIM file.
50  *
51  * @wim
52  *      WIM to read the header from.  @wim->in_fd must be positioned at the
53  *      beginning of the file.
54  *
55  * @hdr
56  *      Structure to read the header into.
57  *
58  * Return values:
59  *      WIMLIB_ERR_SUCCESS (0)
60  *      WIMLIB_ERR_IMAGE_COUNT
61  *      WIMLIB_ERR_INVALID_PART_NUMBER
62  *      WIMLIB_ERR_NOT_A_WIM_FILE
63  *      WIMLIB_ERR_READ
64  *      WIMLIB_ERR_UNEXPECTED_END_OF_FILE
65  *      WIMLIB_ERR_UNKNOWN_VERSION
66  */
67 int
68 read_wim_header(WIMStruct *wim, struct wim_header *hdr)
69 {
70         struct wim_header_disk disk_hdr _aligned_attribute(8);
71         struct filedes *in_fd = &wim->in_fd;
72         const tchar *filename = wim->filename;
73         int ret;
74         tchar *pipe_str;
75
76         wimlib_assert(in_fd->offset == 0);
77
78         if (filename == NULL) {
79                 pipe_str = alloca(40);
80                 tsprintf(pipe_str, T("[fd %d]"), in_fd->fd);
81                 filename = pipe_str;
82         }
83
84         BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE);
85
86         DEBUG("Reading WIM header from \"%"TS"\"", filename);
87
88         ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
89         if (ret)
90                 goto read_error;
91
92         hdr->magic = le64_to_cpu(disk_hdr.magic);
93
94         if (hdr->magic != WIM_MAGIC) {
95                 if (hdr->magic == PWM_MAGIC) {
96                         /* Pipable WIM:  Use header at end instead, unless
97                          * actually reading from a pipe.  */
98                         if (!in_fd->is_pipe) {
99                                 lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END);
100                                 ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
101                                 if (ret)
102                                         goto read_error;
103                         }
104                 } else {
105                         ERROR("\"%"TS"\": Invalid magic characters in header", filename);
106                         return WIMLIB_ERR_NOT_A_WIM_FILE;
107                 }
108         }
109
110         if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
111                 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
112                       filename, le32_to_cpu(disk_hdr.hdr_size));
113                 return WIMLIB_ERR_INVALID_HEADER;
114         }
115
116         hdr->wim_version = le32_to_cpu(disk_hdr.wim_version);
117         if (hdr->wim_version != WIM_VERSION_DEFAULT &&
118             hdr->wim_version != WIM_VERSION_PACKED_STREAMS)
119         {
120                 ERROR("\"%"TS"\": Unknown WIM version: %u",
121                       filename, hdr->wim_version);
122                 return WIMLIB_ERR_UNKNOWN_VERSION;
123         }
124
125         hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
126         hdr->chunk_size = le32_to_cpu(disk_hdr.chunk_size);
127         memcpy(hdr->guid, disk_hdr.guid, WIM_GUID_LEN);
128         hdr->part_number = le16_to_cpu(disk_hdr.part_number);
129         hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
130
131         if (hdr->total_parts == 0 || hdr->part_number == 0 ||
132             hdr->part_number > hdr->total_parts)
133         {
134                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
135                       filename, hdr->part_number, hdr->total_parts);
136                 return WIMLIB_ERR_INVALID_PART_NUMBER;
137         }
138
139         hdr->image_count = le32_to_cpu(disk_hdr.image_count);
140
141         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
142               hdr->part_number, hdr->total_parts, hdr->image_count);
143
144         if (unlikely(hdr->image_count > MAX_IMAGES)) {
145                 ERROR("\"%"TS"\": Invalid image count (%u)",
146                       filename, hdr->image_count);
147                 return WIMLIB_ERR_IMAGE_COUNT;
148         }
149
150         get_wim_reshdr(&disk_hdr.lookup_table_reshdr, &hdr->lookup_table_reshdr);
151         get_wim_reshdr(&disk_hdr.xml_data_reshdr, &hdr->xml_data_reshdr);
152         get_wim_reshdr(&disk_hdr.boot_metadata_reshdr, &hdr->boot_metadata_reshdr);
153         hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
154         get_wim_reshdr(&disk_hdr.integrity_table_reshdr, &hdr->integrity_table_reshdr);
155         return 0;
156
157 read_error:
158         ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
159         return ret;
160 }
161
162 /* Writes the header for a WIM file at the specified offset.  If the offset
163  * specified is the current one, the position is advanced by the size of the
164  * header.  */
165 int
166 write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd,
167                            off_t offset)
168 {
169         struct wim_header_disk disk_hdr _aligned_attribute(8);
170         int ret;
171
172         DEBUG("Writing %sWIM header at offset %"PRIu64,
173               ((hdr->magic == PWM_MAGIC) ? "pipable " : ""),
174               offset);
175
176         disk_hdr.magic = cpu_to_le64(hdr->magic);
177         disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
178         disk_hdr.wim_version = cpu_to_le32(hdr->wim_version);
179         disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
180         if (hdr->flags & WIM_HDR_FLAG_COMPRESSION)
181                 disk_hdr.chunk_size = cpu_to_le32(hdr->chunk_size);
182         else
183                 disk_hdr.chunk_size = 0;
184         memcpy(disk_hdr.guid, hdr->guid, WIM_GUID_LEN);
185
186         disk_hdr.part_number = cpu_to_le16(hdr->part_number);
187         disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
188         disk_hdr.image_count = cpu_to_le32(hdr->image_count);
189         put_wim_reshdr(&hdr->lookup_table_reshdr, &disk_hdr.lookup_table_reshdr);
190         put_wim_reshdr(&hdr->xml_data_reshdr, &disk_hdr.xml_data_reshdr);
191         put_wim_reshdr(&hdr->boot_metadata_reshdr, &disk_hdr.boot_metadata_reshdr);
192         disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
193         put_wim_reshdr(&hdr->integrity_table_reshdr, &disk_hdr.integrity_table_reshdr);
194         memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
195
196         if (offset == out_fd->offset)
197                 ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr));
198         else
199                 ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset);
200         if (ret)
201                 ERROR_WITH_ERRNO("Failed to write WIM header");
202         return ret;
203 }
204
205 /* Writes the header for a WIM file at the output file descriptor's current
206  * offset.  */
207 int
208 write_wim_header(const struct wim_header *hdr, struct filedes *out_fd)
209 {
210         return write_wim_header_at_offset(hdr, out_fd, out_fd->offset);
211 }
212
213 /* Update just the wim_flags field. */
214 int
215 write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd)
216 {
217         le32 flags = cpu_to_le32(hdr_flags);
218
219         return full_pwrite(out_fd, &flags, sizeof(flags),
220                            offsetof(struct wim_header_disk, wim_flags));
221 }
222
223 int
224 set_wim_hdr_cflags(int ctype, struct wim_header *hdr)
225 {
226         hdr->flags &= ~(WIM_HDR_FLAG_COMPRESSION |
227                         WIM_HDR_FLAG_COMPRESS_LZX |
228                         WIM_HDR_FLAG_COMPRESS_RESERVED |
229                         WIM_HDR_FLAG_COMPRESS_XPRESS |
230                         WIM_HDR_FLAG_COMPRESS_LZMS |
231                         WIM_HDR_FLAG_COMPRESS_XPRESS_2);
232         switch (ctype) {
233
234         case WIMLIB_COMPRESSION_TYPE_NONE:
235                 return 0;
236
237         case WIMLIB_COMPRESSION_TYPE_LZX:
238                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZX;
239                 return 0;
240
241         case WIMLIB_COMPRESSION_TYPE_XPRESS:
242                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_XPRESS;
243                 return 0;
244
245         case WIMLIB_COMPRESSION_TYPE_LZMS:
246                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZMS;
247                 return 0;
248
249         default:
250                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
251         }
252 }
253
254 /*
255  * Initializes the header for a WIM file.
256  */
257 int
258 init_wim_header(struct wim_header *hdr, int ctype, u32 chunk_size)
259 {
260         memset(hdr, 0, sizeof(struct wim_header));
261         hdr->magic = WIM_MAGIC;
262
263         if (ctype == WIMLIB_COMPRESSION_TYPE_LZMS)
264                 hdr->wim_version = WIM_VERSION_PACKED_STREAMS;
265         else
266                 hdr->wim_version = WIM_VERSION_DEFAULT;
267         if (set_wim_hdr_cflags(ctype, hdr)) {
268                 ERROR("Invalid compression type specified (%d)", ctype);
269                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
270         }
271         hdr->chunk_size = chunk_size;
272         hdr->total_parts = 1;
273         hdr->part_number = 1;
274         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
275         return 0;
276 }
277
278 struct hdr_flag {
279         u32 flag;
280         const char *name;
281 };
282 struct hdr_flag hdr_flags[] = {
283         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
284         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
285         {WIM_HDR_FLAG_READONLY,         "READONLY"},
286         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
287         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
288         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
289         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
290         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
291         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
292         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
293         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
294         {WIM_HDR_FLAG_COMPRESS_LZMS,    "COMPRESS_LZMS"},
295         {WIM_HDR_FLAG_COMPRESS_XPRESS_2,"COMPRESS_XPRESS_2"},
296 };
297
298 /* API function documented in wimlib.h  */
299 WIMLIBAPI void
300 wimlib_print_header(const WIMStruct *wim)
301 {
302         const struct wim_header *hdr = &wim->hdr;
303
304         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
305         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
306         tprintf(T("Version                     = 0x%x\n"), hdr->wim_version);
307
308         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
309         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
310                 if (hdr_flags[i].flag & hdr->flags)
311                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
312
313         tprintf(T("Chunk Size                  = %u\n"), hdr->chunk_size);
314         tfputs (T("GUID                        = "), stdout);
315         print_byte_field(hdr->guid, WIM_GUID_LEN, stdout);
316         tputchar(T('\n'));
317         tprintf(T("Part Number                 = %hu\n"), hdr->part_number);
318         tprintf(T("Total Parts                 = %hu\n"), hdr->total_parts);
319         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
320         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
321                                 (u64)hdr->lookup_table_reshdr.size_in_wim);
322         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
323                                 (u8)hdr->lookup_table_reshdr.flags);
324         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
325                                 hdr->lookup_table_reshdr.offset_in_wim);
326         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
327                                 hdr->lookup_table_reshdr.uncompressed_size);
328         tprintf(T("XML Data Size               = %"PRIu64"\n"),
329                                 (u64)hdr->xml_data_reshdr.size_in_wim);
330         tprintf(T("XML Data Flags              = 0x%hhx\n"),
331                                 (u8)hdr->xml_data_reshdr.flags);
332         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
333                                 hdr->xml_data_reshdr.offset_in_wim);
334         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
335                                 hdr->xml_data_reshdr.uncompressed_size);
336         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
337                                 (u64)hdr->boot_metadata_reshdr.size_in_wim);
338         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
339                                 (u8)hdr->boot_metadata_reshdr.flags);
340         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
341                                 hdr->boot_metadata_reshdr.offset_in_wim);
342         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
343                                 hdr->boot_metadata_reshdr.uncompressed_size);
344         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
345         tprintf(T("Integrity Size              = %"PRIu64"\n"),
346                                 (u64)hdr->integrity_table_reshdr.size_in_wim);
347         tprintf(T("Integrity Flags             = 0x%hhx\n"),
348                                 (u8)hdr->integrity_table_reshdr.flags);
349         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
350                                 hdr->integrity_table_reshdr.offset_in_wim);
351         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
352                                 hdr->integrity_table_reshdr.uncompressed_size);
353 }