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,
119 struct wim_header *hdr, int open_flags)
121 struct wim_header_disk disk_hdr _aligned_attribute(8);
123 BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE);
125 DEBUG("Reading WIM header from \"%"TS"\"", filename);
127 if (full_pread(in_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) {
128 ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
129 return WIMLIB_ERR_READ;
132 if (disk_hdr.magic != WIM_MAGIC) {
133 ERROR("\"%"TS"\": Invalid magic characters in header", filename);
134 return WIMLIB_ERR_NOT_A_WIM_FILE;
137 if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
138 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
139 filename, le32_to_cpu(disk_hdr.hdr_size));
140 return WIMLIB_ERR_INVALID_HEADER_SIZE;
143 if (le32_to_cpu(disk_hdr.wim_version) != WIM_VERSION) {
144 ERROR("\"%"TS"\": The WIM header says the WIM version is %u, "
145 "but wimlib only knows about version %u",
146 filename, le32_to_cpu(disk_hdr.wim_version), WIM_VERSION);
147 return WIMLIB_ERR_UNKNOWN_VERSION;
150 hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
151 if (le32_to_cpu(disk_hdr.chunk_size) != WIM_CHUNK_SIZE &&
152 (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
153 ERROR("\"%"TS"\": Unexpected chunk size of %u! Ask the author to "
154 "implement support for other chunk sizes.",
155 filename, le32_to_cpu(disk_hdr.chunk_size));
156 ERROR("(Or it might just be that the WIM header is invalid.)");
157 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
160 memcpy(hdr->guid, disk_hdr.guid, WIM_GID_LEN);
162 hdr->part_number = le16_to_cpu(disk_hdr.part_number);
163 hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
165 if (hdr->total_parts == 0 || hdr->part_number == 0 ||
166 hdr->part_number > hdr->total_parts)
168 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
169 filename, hdr->part_number, hdr->total_parts);
170 return WIMLIB_ERR_INVALID_PART_NUMBER;
173 if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) && hdr->total_parts != 1)
175 ERROR("\"%"TS"\": This WIM is part %u of a %u-part WIM",
176 filename, hdr->part_number, hdr->total_parts);
177 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
180 hdr->image_count = le32_to_cpu(disk_hdr.image_count);
182 DEBUG("part_number = %u, total_parts = %u, image_count = %u",
183 hdr->part_number, hdr->total_parts, hdr->image_count);
185 if (hdr->image_count >= INT_MAX) {
186 ERROR("\"%"TS"\": Invalid image count (%u)",
187 filename, hdr->image_count);
188 return WIMLIB_ERR_IMAGE_COUNT;
191 get_resource_entry(&disk_hdr.lookup_table_res_entry, &hdr->lookup_table_res_entry);
192 get_resource_entry(&disk_hdr.xml_data_res_entry, &hdr->xml_res_entry);
193 get_resource_entry(&disk_hdr.boot_metadata_res_entry, &hdr->boot_metadata_res_entry);
194 hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
195 get_resource_entry(&disk_hdr.integrity_table_res_entry, &hdr->integrity);
200 * Writes the header for a WIM file.
202 * @hdr: A pointer to a struct wim_header structure that describes the header.
203 * @out_fd: The file descriptor to the WIM file, opened for writing.
205 * Returns zero on success, nonzero on failure.
208 write_header(const struct wim_header *hdr, int out_fd)
210 struct wim_header_disk disk_hdr _aligned_attribute(8);
211 DEBUG("Writing WIM header.");
213 disk_hdr.magic = WIM_MAGIC;
214 disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
215 disk_hdr.wim_version = cpu_to_le32(WIM_VERSION);
216 disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
217 disk_hdr.chunk_size = cpu_to_le32((hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
219 memcpy(disk_hdr.guid, hdr->guid, WIM_GID_LEN);
221 disk_hdr.part_number = cpu_to_le16(hdr->part_number);
222 disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
223 disk_hdr.image_count = cpu_to_le32(hdr->image_count);
224 put_resource_entry(&hdr->lookup_table_res_entry, &disk_hdr.lookup_table_res_entry);
225 put_resource_entry(&hdr->xml_res_entry, &disk_hdr.xml_data_res_entry);
226 put_resource_entry(&hdr->boot_metadata_res_entry, &disk_hdr.boot_metadata_res_entry);
227 disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
228 put_resource_entry(&hdr->integrity, &disk_hdr.integrity_table_res_entry);
229 memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
231 if (full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) {
232 ERROR_WITH_ERRNO("Failed to write WIM header");
233 return WIMLIB_ERR_WRITE;
235 DEBUG("Done writing WIM header");
240 * Initializes the header for a WIM file.
243 init_header(struct wim_header *hdr, int ctype)
245 memset(hdr, 0, sizeof(struct wim_header));
247 case WIMLIB_COMPRESSION_TYPE_NONE:
250 case WIMLIB_COMPRESSION_TYPE_LZX:
251 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
252 WIM_HDR_FLAG_COMPRESS_LZX;
254 case WIMLIB_COMPRESSION_TYPE_XPRESS:
255 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
256 WIM_HDR_FLAG_COMPRESS_XPRESS;
259 ERROR("Invalid compression type specified (%d)", ctype);
260 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
262 hdr->total_parts = 1;
263 hdr->part_number = 1;
264 randomize_byte_array(hdr->guid, sizeof(hdr->guid));
272 struct hdr_flag hdr_flags[] = {
273 {WIM_HDR_FLAG_RESERVED, "RESERVED"},
274 {WIM_HDR_FLAG_COMPRESSION, "COMPRESSION"},
275 {WIM_HDR_FLAG_READONLY, "READONLY"},
276 {WIM_HDR_FLAG_SPANNED, "SPANNED"},
277 {WIM_HDR_FLAG_RESOURCE_ONLY, "RESOURCE_ONLY"},
278 {WIM_HDR_FLAG_METADATA_ONLY, "METADATA_ONLY"},
279 {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
280 {WIM_HDR_FLAG_RP_FIX, "RP_FIX"},
281 {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
282 {WIM_HDR_FLAG_COMPRESS_LZX, "COMPRESS_LZX"},
283 {WIM_HDR_FLAG_COMPRESS_XPRESS, "COMPRESS_XPRESS"},
286 /* Prints information from the header of the WIM file associated with @w. */
288 wimlib_print_header(const WIMStruct *w)
290 const struct wim_header *hdr = &w->hdr;
292 tprintf(T("Magic Characters = MSWIM\\000\\000\\000\n"));
293 tprintf(T("Header Size = %u\n"), WIM_HEADER_DISK_SIZE);
294 tprintf(T("Version = 0x%x\n"), WIM_VERSION);
296 tprintf(T("Flags = 0x%x\n"), hdr->flags);
297 for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
298 if (hdr_flags[i].flag & hdr->flags)
299 tprintf(T(" WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
301 tprintf(T("Chunk Size = %u\n"), WIM_CHUNK_SIZE);
302 tfputs (T("GUID = "), stdout);
303 print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
305 tprintf(T("Part Number = %hu\n"), w->hdr.part_number);
306 tprintf(T("Total Parts = %hu\n"), w->hdr.total_parts);
307 tprintf(T("Image Count = %u\n"), hdr->image_count);
308 tprintf(T("Lookup Table Size = %"PRIu64"\n"),
309 (u64)hdr->lookup_table_res_entry.size);
310 tprintf(T("Lookup Table Flags = 0x%hhx\n"),
311 (u8)hdr->lookup_table_res_entry.flags);
312 tprintf(T("Lookup Table Offset = %"PRIu64"\n"),
313 hdr->lookup_table_res_entry.offset);
314 tprintf(T("Lookup Table Original_size = %"PRIu64"\n"),
315 hdr->lookup_table_res_entry.original_size);
316 tprintf(T("XML Data Size = %"PRIu64"\n"),
317 (u64)hdr->xml_res_entry.size);
318 tprintf(T("XML Data Flags = 0x%hhx\n"),
319 (u8)hdr->xml_res_entry.flags);
320 tprintf(T("XML Data Offset = %"PRIu64"\n"),
321 hdr->xml_res_entry.offset);
322 tprintf(T("XML Data Original Size = %"PRIu64"\n"),
323 hdr->xml_res_entry.original_size);
324 tprintf(T("Boot Metadata Size = %"PRIu64"\n"),
325 (u64)hdr->boot_metadata_res_entry.size);
326 tprintf(T("Boot Metadata Flags = 0x%hhx\n"),
327 (u8)hdr->boot_metadata_res_entry.flags);
328 tprintf(T("Boot Metadata Offset = %"PRIu64"\n"),
329 hdr->boot_metadata_res_entry.offset);
330 tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
331 hdr->boot_metadata_res_entry.original_size);
332 tprintf(T("Boot Index = %u\n"), hdr->boot_idx);
333 tprintf(T("Integrity Size = %"PRIu64"\n"),
334 (u64)hdr->integrity.size);
335 tprintf(T("Integrity Flags = 0x%hhx\n"),
336 (u8)hdr->integrity.flags);
337 tprintf(T("Integrity Offset = %"PRIu64"\n"),
338 hdr->integrity.offset);
339 tprintf(T("Integrity Original_size = %"PRIu64"\n"),
340 hdr->integrity.original_size);