4 * Read, write, or create a WIM header.
8 * Copyright (C) 2012, 2013 Eric Biggers
10 * This file is part of wimlib, a library for working with WIM files.
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)
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
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/.
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"
42 /* WIM magic characters, translated to a single 64-bit little endian number. */
44 cpu_to_le64(((u64)'M' << 0) | \
53 /* On-disk format of the WIM header. */
54 struct wim_header_disk {
56 /* Magic characters "MSWIM\0\0\0" */
59 /* Size of the WIM header, in bytes; WIM_HEADER_DISK_SIZE expected
60 * (currently the only supported value). */
63 /* Version of the WIM file; WIM_VERSION expected (currently the only
64 * supported value). */
67 /* Flags for the WIM file (WIM_HDR_FLAG_*) */
70 /* Uncompressed chunk size of resources in the WIM. 0 if the WIM is
71 * uncompressed. If compressed, WIM_CHUNK_SIZE is expected (currently
72 * the only supported value). */
75 /* Globally unique identifier for the WIM file. Basically a bunch of
79 /* Number of this WIM part in the split WIM file, indexed from 1, or 1
80 * if the WIM is not split. */
83 /* Total number of parts of the split WIM file, or 1 if the WIM is not
87 /* Number of images in the WIM. */
90 /* Location and size of the WIM's lookup table. */
91 struct resource_entry_disk lookup_table_res_entry;
93 /* Location and size of the WIM's XML data. */
94 struct resource_entry_disk xml_data_res_entry;
96 /* Location and size of metadata resource for the bootable image of the
97 * WIM, or all zeroes if no image is bootable. */
98 struct resource_entry_disk boot_metadata_res_entry;
100 /* 1-based index of the bootable image of the WIM, or 0 if no image is
104 /* Location and size of the WIM's integrity table, or all zeroes if the
105 * WIM has no integrity table.
107 * Note the integrity_table_res_entry here is 4-byte aligned even though
108 * it would ordinarily be 8-byte aligned--- hence, the _packed_attribute
109 * on the `struct wim_header_disk' is essential. */
110 struct resource_entry_disk integrity_table_res_entry;
116 /* Reads the header from a WIM file. */
118 read_header(const tchar *filename, int in_fd, struct wim_header *hdr)
120 struct wim_header_disk disk_hdr _aligned_attribute(8);
122 BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE);
124 DEBUG("Reading WIM header from \"%"TS"\"", filename);
126 if (full_pread(in_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) {
127 ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
128 return WIMLIB_ERR_READ;
131 if (disk_hdr.magic != WIM_MAGIC) {
132 ERROR("\"%"TS"\": Invalid magic characters in header", filename);
133 return WIMLIB_ERR_NOT_A_WIM_FILE;
136 if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
137 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
138 filename, le32_to_cpu(disk_hdr.hdr_size));
139 return WIMLIB_ERR_INVALID_HEADER_SIZE;
142 if (le32_to_cpu(disk_hdr.wim_version) != WIM_VERSION) {
143 ERROR("\"%"TS"\": The WIM header says the WIM version is %u, "
144 "but wimlib only knows about version %u",
145 filename, le32_to_cpu(disk_hdr.wim_version), WIM_VERSION);
146 return WIMLIB_ERR_UNKNOWN_VERSION;
149 hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
150 if (le32_to_cpu(disk_hdr.chunk_size) != WIM_CHUNK_SIZE &&
151 (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
152 ERROR("\"%"TS"\": Unexpected chunk size of %u! Ask the author to "
153 "implement support for other chunk sizes.",
154 filename, le32_to_cpu(disk_hdr.chunk_size));
155 ERROR("(Or it might just be that the WIM header is invalid.)");
156 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
159 memcpy(hdr->guid, disk_hdr.guid, WIM_GID_LEN);
161 hdr->part_number = le16_to_cpu(disk_hdr.part_number);
162 hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
164 if (hdr->total_parts == 0 || hdr->part_number == 0 ||
165 hdr->part_number > hdr->total_parts)
167 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
168 filename, hdr->part_number, hdr->total_parts);
169 return WIMLIB_ERR_INVALID_PART_NUMBER;
172 hdr->image_count = le32_to_cpu(disk_hdr.image_count);
174 DEBUG("part_number = %u, total_parts = %u, image_count = %u",
175 hdr->part_number, hdr->total_parts, hdr->image_count);
177 if (hdr->image_count >= INT_MAX) {
178 ERROR("\"%"TS"\": Invalid image count (%u)",
179 filename, hdr->image_count);
180 return WIMLIB_ERR_IMAGE_COUNT;
183 get_resource_entry(&disk_hdr.lookup_table_res_entry, &hdr->lookup_table_res_entry);
184 get_resource_entry(&disk_hdr.xml_data_res_entry, &hdr->xml_res_entry);
185 get_resource_entry(&disk_hdr.boot_metadata_res_entry, &hdr->boot_metadata_res_entry);
186 hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
187 get_resource_entry(&disk_hdr.integrity_table_res_entry, &hdr->integrity);
192 * Writes the header for a WIM file.
194 * @hdr: A pointer to a struct wim_header structure that describes the header.
195 * @out_fd: The file descriptor to the WIM file, opened for writing.
197 * Returns zero on success, nonzero on failure.
200 write_header(const struct wim_header *hdr, int out_fd)
202 struct wim_header_disk disk_hdr _aligned_attribute(8);
203 DEBUG("Writing WIM header.");
205 disk_hdr.magic = WIM_MAGIC;
206 disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
207 disk_hdr.wim_version = cpu_to_le32(WIM_VERSION);
208 disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
209 disk_hdr.chunk_size = cpu_to_le32((hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
211 memcpy(disk_hdr.guid, hdr->guid, WIM_GID_LEN);
213 disk_hdr.part_number = cpu_to_le16(hdr->part_number);
214 disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
215 disk_hdr.image_count = cpu_to_le32(hdr->image_count);
216 put_resource_entry(&hdr->lookup_table_res_entry, &disk_hdr.lookup_table_res_entry);
217 put_resource_entry(&hdr->xml_res_entry, &disk_hdr.xml_data_res_entry);
218 put_resource_entry(&hdr->boot_metadata_res_entry, &disk_hdr.boot_metadata_res_entry);
219 disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
220 put_resource_entry(&hdr->integrity, &disk_hdr.integrity_table_res_entry);
221 memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
223 if (full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) {
224 ERROR_WITH_ERRNO("Failed to write WIM header");
225 return WIMLIB_ERR_WRITE;
227 DEBUG("Done writing WIM header");
231 /* Update just the wim_flags field. */
233 write_header_flags(u32 hdr_flags, int out_fd)
235 le32 flags = cpu_to_le32(hdr_flags);
236 if (full_pwrite(out_fd, &flags, sizeof(flags),
237 offsetof(struct wim_header_disk, wim_flags)) != sizeof(flags))
239 return WIMLIB_ERR_WRITE;
246 /* Update just the part_number and total_parts fields. */
248 write_header_part_data(u16 part_number, u16 total_parts, int out_fd)
250 le16 part_data[2] = {
251 cpu_to_le16(part_number),
252 cpu_to_le16(total_parts),
254 if (full_pwrite(out_fd, &part_data, sizeof(part_data),
255 offsetof(struct wim_header_disk, part_number)) != sizeof(part_data))
257 return WIMLIB_ERR_WRITE;
264 * Initializes the header for a WIM file.
267 init_header(struct wim_header *hdr, int ctype)
269 memset(hdr, 0, sizeof(struct wim_header));
271 case WIMLIB_COMPRESSION_TYPE_NONE:
274 case WIMLIB_COMPRESSION_TYPE_LZX:
275 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
276 WIM_HDR_FLAG_COMPRESS_LZX;
278 case WIMLIB_COMPRESSION_TYPE_XPRESS:
279 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
280 WIM_HDR_FLAG_COMPRESS_XPRESS;
283 ERROR("Invalid compression type specified (%d)", ctype);
284 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
286 hdr->total_parts = 1;
287 hdr->part_number = 1;
288 randomize_byte_array(hdr->guid, sizeof(hdr->guid));
296 struct hdr_flag hdr_flags[] = {
297 {WIM_HDR_FLAG_RESERVED, "RESERVED"},
298 {WIM_HDR_FLAG_COMPRESSION, "COMPRESSION"},
299 {WIM_HDR_FLAG_READONLY, "READONLY"},
300 {WIM_HDR_FLAG_SPANNED, "SPANNED"},
301 {WIM_HDR_FLAG_RESOURCE_ONLY, "RESOURCE_ONLY"},
302 {WIM_HDR_FLAG_METADATA_ONLY, "METADATA_ONLY"},
303 {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
304 {WIM_HDR_FLAG_RP_FIX, "RP_FIX"},
305 {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
306 {WIM_HDR_FLAG_COMPRESS_LZX, "COMPRESS_LZX"},
307 {WIM_HDR_FLAG_COMPRESS_XPRESS, "COMPRESS_XPRESS"},
310 /* Prints information from the header of the WIM file associated with @wim. */
312 wimlib_print_header(const WIMStruct *wim)
314 const struct wim_header *hdr = &wim->hdr;
316 tprintf(T("Magic Characters = MSWIM\\000\\000\\000\n"));
317 tprintf(T("Header Size = %u\n"), WIM_HEADER_DISK_SIZE);
318 tprintf(T("Version = 0x%x\n"), WIM_VERSION);
320 tprintf(T("Flags = 0x%x\n"), hdr->flags);
321 for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
322 if (hdr_flags[i].flag & hdr->flags)
323 tprintf(T(" WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
325 tprintf(T("Chunk Size = %u\n"), WIM_CHUNK_SIZE);
326 tfputs (T("GUID = "), stdout);
327 print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
329 tprintf(T("Part Number = %hu\n"), wim->hdr.part_number);
330 tprintf(T("Total Parts = %hu\n"), wim->hdr.total_parts);
331 tprintf(T("Image Count = %u\n"), hdr->image_count);
332 tprintf(T("Lookup Table Size = %"PRIu64"\n"),
333 (u64)hdr->lookup_table_res_entry.size);
334 tprintf(T("Lookup Table Flags = 0x%hhx\n"),
335 (u8)hdr->lookup_table_res_entry.flags);
336 tprintf(T("Lookup Table Offset = %"PRIu64"\n"),
337 hdr->lookup_table_res_entry.offset);
338 tprintf(T("Lookup Table Original_size = %"PRIu64"\n"),
339 hdr->lookup_table_res_entry.original_size);
340 tprintf(T("XML Data Size = %"PRIu64"\n"),
341 (u64)hdr->xml_res_entry.size);
342 tprintf(T("XML Data Flags = 0x%hhx\n"),
343 (u8)hdr->xml_res_entry.flags);
344 tprintf(T("XML Data Offset = %"PRIu64"\n"),
345 hdr->xml_res_entry.offset);
346 tprintf(T("XML Data Original Size = %"PRIu64"\n"),
347 hdr->xml_res_entry.original_size);
348 tprintf(T("Boot Metadata Size = %"PRIu64"\n"),
349 (u64)hdr->boot_metadata_res_entry.size);
350 tprintf(T("Boot Metadata Flags = 0x%hhx\n"),
351 (u8)hdr->boot_metadata_res_entry.flags);
352 tprintf(T("Boot Metadata Offset = %"PRIu64"\n"),
353 hdr->boot_metadata_res_entry.offset);
354 tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
355 hdr->boot_metadata_res_entry.original_size);
356 tprintf(T("Boot Index = %u\n"), hdr->boot_idx);
357 tprintf(T("Integrity Size = %"PRIu64"\n"),
358 (u64)hdr->integrity.size);
359 tprintf(T("Integrity Flags = 0x%hhx\n"),
360 (u8)hdr->integrity.flags);
361 tprintf(T("Integrity Offset = %"PRIu64"\n"),
362 hdr->integrity.offset);
363 tprintf(T("Integrity Original_size = %"PRIu64"\n"),
364 hdr->integrity.original_size);