wimlib.net Git - wimlib/blob - 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/buffer_io.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
  41 /* First 8 bytes in every WIM file. */
  42 static const u8 wim_magic_chars[WIM_MAGIC_LEN] = {
  43                         'M', 'S', 'W', 'I', 'M', '\0', '\0', '\0' };
  44
  45 /* Reads the header from a WIM file.  */
  46 int
  47 read_header(const tchar *filename, int in_fd,
  48             struct wim_header *hdr, int open_flags)
  49 {
  50         size_t bytes_read;
  51         u8 buf[WIM_HEADER_DISK_SIZE];
  52         const void *p;
  53
  54         u32 hdr_size;
  55         u32 wim_version;
  56         u32 chunk_size;
  57
  58         DEBUG("Reading WIM header from \"%"TS"\".", filename);
  59
  60         bytes_read = full_pread(in_fd, buf, WIM_HEADER_DISK_SIZE, 0);
  61
  62         if (bytes_read != WIM_HEADER_DISK_SIZE) {
  63                 ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
  64                 return WIMLIB_ERR_READ;
  65         }
  66
  67         p = buf;
  68         if (memcmp(p, wim_magic_chars, WIM_MAGIC_LEN)) {
  69                 ERROR("\"%"TS"\": Invalid magic characters in header", filename);
  70                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  71         }
  72
  73         /* Byte 8 */
  74         p = get_u32(p + 8, &hdr_size);
  75         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  76                 ERROR("\"%"TS"\": Header is %u bytes (expected %u bytes)",
  77                       filename, hdr_size, WIM_HEADER_DISK_SIZE);
  78                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  79         }
  80
  81         /* Byte 12 */
  82         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  83         if (wim_version != WIM_VERSION) {
  84                 ERROR("\"%"TS"\": The WIM header says the WIM version is %u, "
  85                       "but wimlib only knows about version %u",
  86                       filename, wim_version, WIM_VERSION);
  87                 return WIMLIB_ERR_UNKNOWN_VERSION;
  88         }
  89
  90         p = get_u32(p, &hdr->flags);
  91         p = get_u32(p, &chunk_size);
  92         if (chunk_size != WIM_CHUNK_SIZE &&
  93             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  94                 ERROR("\"%"TS"\": Unexpected chunk size of %u! Ask the author to "
  95                       "implement support for other chunk sizes.",
  96                       filename, chunk_size);
  97                 ERROR("(Or it might just be that the WIM header is invalid.)");
  98                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
  99         }
 100
 101         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
 102         p = get_u16(p, &hdr->part_number);
 103         p = get_u16(p, &hdr->total_parts);
 104
 105         if (hdr->total_parts == 0 ||
 106             hdr->part_number == 0 ||
 107             hdr->part_number > hdr->total_parts)
 108         {
 109                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
 110                       filename, hdr->part_number, hdr->total_parts);
 111                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 112         }
 113
 114         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) &&
 115             hdr->total_parts != 1)
 116         {
 117                 ERROR("\"%"TS"\": This WIM is part %u of a %u-part WIM",
 118                       filename, hdr->part_number, hdr->total_parts);
 119                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 120         }
 121
 122         p = get_u32(p, &hdr->image_count);
 123
 124         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 125               hdr->part_number, hdr->total_parts, hdr->image_count);
 126
 127         if (hdr->image_count >= INT_MAX) {
 128                 ERROR("\"%"TS"\": Invalid image count (%u)",
 129                       filename, hdr->image_count);
 130                 return WIMLIB_ERR_IMAGE_COUNT;
 131         }
 132
 133         /* Byte 48 */
 134
 135         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 136         p = get_resource_entry(p, &hdr->xml_res_entry);
 137         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 138
 139         /* Byte 120 */
 140
 141         p = get_u32(p, &hdr->boot_idx);
 142
 143         /* Byte 124 */
 144
 145         p = get_resource_entry(p, &hdr->integrity);
 146
 147         /* Byte 148 */
 148
 149         /* 60 bytes of unused stuff. */
 150
 151         /* Byte 208 */
 152
 153         return 0;
 154 }
 155
 156 /*
 157  * Writes the header for a WIM file.
 158  *
 159  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 160  * @out_fd:     The file descriptor to the WIM file, opened for writing.
 161  *
 162  * Returns zero on success, nonzero on failure.
 163  */
 164 int
 165 write_header(const struct wim_header *hdr, int out_fd)
 166 {
 167         u8 buf[WIM_HEADER_DISK_SIZE];
 168         u8 *p;
 169         DEBUG("Writing WIM header.");
 170
 171         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 172         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 173         p = put_u32(p, WIM_VERSION);
 174         p = put_u32(p, hdr->flags);
 175         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 176                                 WIM_CHUNK_SIZE : 0);
 177         /* Byte 24 */
 178
 179         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 180         p = put_u16(p, hdr->part_number);
 181
 182         /* Byte 40 */
 183
 184         p = put_u16(p, hdr->total_parts);
 185         p = put_u32(p, hdr->image_count);
 186         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 187         p = put_resource_entry(p, &hdr->xml_res_entry);
 188         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 189         p = put_u32(p, hdr->boot_idx);
 190         p = put_resource_entry(p, &hdr->integrity);
 191         p = put_zeroes(p, WIM_UNUSED_LEN);
 192         wimlib_assert(p - buf == sizeof(buf));
 193
 194         if (full_pwrite(out_fd, buf, sizeof(buf), 0) != sizeof(buf)) {
 195                 ERROR_WITH_ERRNO("Failed to write WIM header");
 196                 return WIMLIB_ERR_WRITE;
 197         }
 198         DEBUG("Done writing WIM header");
 199         return 0;
 200 }
 201
 202 /*
 203  * Initializes the header for a WIM file.
 204  */
 205 int
 206 init_header(struct wim_header *hdr, int ctype)
 207 {
 208         memset(hdr, 0, sizeof(struct wim_header));
 209         switch (ctype) {
 210         case WIMLIB_COMPRESSION_TYPE_NONE:
 211                 hdr->flags = 0;
 212                 break;
 213         case WIMLIB_COMPRESSION_TYPE_LZX:
 214                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 215                              WIM_HDR_FLAG_COMPRESS_LZX;
 216                 break;
 217         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 218                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 219                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 220                 break;
 221         default:
 222                 ERROR("Invalid compression type specified (%d)", ctype);
 223                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 224         }
 225         hdr->total_parts = 1;
 226         hdr->part_number = 1;
 227         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 228         return 0;
 229 }
 230
 231 struct hdr_flag {
 232         u32 flag;
 233         const char *name;
 234 };
 235 struct hdr_flag hdr_flags[] = {
 236         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 237         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 238         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 239         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 240         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 241         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 242         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 243         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 244         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 245         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 246         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 247 };
 248
 249 /* Prints information from the header of the WIM file associated with @w. */
 250 WIMLIBAPI void
 251 wimlib_print_header(const WIMStruct *w)
 252 {
 253         const struct wim_header *hdr = &w->hdr;
 254
 255         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 256         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 257         tprintf(T("Version                     = 0x%x\n"), WIM_VERSION);
 258
 259         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 260         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 261                 if (hdr_flags[i].flag & hdr->flags)
 262                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 263
 264         tprintf(T("Chunk Size                  = %u\n"), WIM_CHUNK_SIZE);
 265         tfputs (T("GUID                        = "), stdout);
 266         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 267         tputchar(T('\n'));
 268         tprintf(T("Part Number                 = %hu\n"), w->hdr.part_number);
 269         tprintf(T("Total Parts                 = %hu\n"), w->hdr.total_parts);
 270         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 271         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 272                                 (u64)hdr->lookup_table_res_entry.size);
 273         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 274                                 (u8)hdr->lookup_table_res_entry.flags);
 275         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 276                                 hdr->lookup_table_res_entry.offset);
 277         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 278                                 hdr->lookup_table_res_entry.original_size);
 279         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 280                                 (u64)hdr->xml_res_entry.size);
 281         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 282                                 (u8)hdr->xml_res_entry.flags);
 283         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 284                                 hdr->xml_res_entry.offset);
 285         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 286                                 hdr->xml_res_entry.original_size);
 287         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 288                                 (u64)hdr->boot_metadata_res_entry.size);
 289         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 290                                 (u8)hdr->boot_metadata_res_entry.flags);
 291         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 292                                 hdr->boot_metadata_res_entry.offset);
 293         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 294                                 hdr->boot_metadata_res_entry.original_size);
 295         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 296         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 297                                 (u64)hdr->integrity.size);
 298         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 299                                 (u8)hdr->integrity.flags);
 300         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 301                                 hdr->integrity.offset);
 302         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 303                                 hdr->integrity.original_size);
 304 }