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) 2010 Carl Thijssen
   9  * Copyright (C) 2012 Eric Biggers
  10  *
  11  * This file is part of wimlib, a library for working with WIM files.
  12  *
  13  * wimlib is free software; you can redistribute it and/or modify it under the
  14  * terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 3 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  25  */
  26
  27 #include "wimlib_internal.h"
  28 #include "io.h"
  29 #include <limits.h>
  30
  31 /* First 8 bytes in every WIM file. */
  32 static const u8 wim_magic_chars[WIM_MAGIC_LEN] = {
  33                         'M', 'S', 'W', 'I', 'M', '\0', '\0', '\0' };
  34
  35 /* Reads the header for a WIM file.  */
  36 int read_header(FILE *fp, struct wim_header *hdr, int open_flags)
  37 {
  38         size_t bytes_read;
  39         u8 buf[WIM_HEADER_DISK_SIZE];
  40         size_t hdr_rem_size;
  41         const u8 *p;
  42
  43         u32 hdr_size;
  44         u32 wim_version;
  45         u32 chunk_size;
  46
  47         DEBUG("Reading WIM header.");
  48
  49         bytes_read = fread(buf, 1, WIM_MAGIC_LEN, fp);
  50
  51         if (bytes_read != WIM_MAGIC_LEN)
  52                 goto err;
  53
  54         /* Byte 8 */
  55
  56         if (memcmp(buf, wim_magic_chars, WIM_MAGIC_LEN) != 0) {
  57                 ERROR("Invalid magic characters in WIM header");
  58                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  59         }
  60
  61         bytes_read = fread(&hdr_size, 1, sizeof(u32), fp);
  62         if (bytes_read != sizeof(u32))
  63                 goto err;
  64
  65         hdr_size = le32_to_cpu(hdr_size);
  66
  67         /* Byte 12 */
  68
  69         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  70                 ERROR("Header is %u bytes (expected %u bytes)",
  71                       hdr_size, WIM_HEADER_DISK_SIZE);
  72                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  73         }
  74
  75         /* Read the rest of the header into a buffer. */
  76
  77         hdr_rem_size = WIM_HEADER_DISK_SIZE - WIM_MAGIC_LEN - sizeof(u32);
  78
  79         bytes_read = fread(buf + WIM_MAGIC_LEN + sizeof(u32), 1,
  80                            hdr_rem_size, fp);
  81         if (bytes_read != hdr_rem_size)
  82                 goto err;
  83
  84         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  85
  86         if (wim_version != WIM_VERSION) {
  87                 ERROR("The WIM header says the WIM version is %u, but wimlib "
  88                       "only knows about version %u",
  89                       wim_version, WIM_VERSION);
  90                 return WIMLIB_ERR_UNKNOWN_VERSION;
  91         }
  92
  93         p = get_u32(p, &hdr->flags);
  94         p = get_u32(p, &chunk_size);
  95         if (chunk_size != WIM_CHUNK_SIZE &&
  96             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  97                 ERROR("Unexpected chunk size of %u! Ask the author to "
  98                       "implement support for other chunk sizes.",
  99                       chunk_size);
 100                 ERROR("(Or it might just be that the WIM header is invalid.)");
 101                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 102         }
 103
 104         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
 105         p = get_u16(p, &hdr->part_number);
 106         p = get_u16(p, &hdr->total_parts);
 107
 108         if (hdr->total_parts == 0 ||
 109             hdr->part_number == 0 ||
 110             hdr->part_number > hdr->total_parts)
 111         {
 112                 ERROR("Invalid WIM part number: %hu of %hu",
 113                       hdr->part_number, hdr->total_parts);
 114                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 115         }
 116
 117         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK)
 118             && (hdr->part_number != 1 || hdr->total_parts != 1))
 119         {
 120                 ERROR("This WIM is part %u of a %u-part WIM",
 121                       hdr->part_number, hdr->total_parts);
 122                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 123         }
 124
 125         p = get_u32(p, &hdr->image_count);
 126
 127         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 128               hdr->part_number, hdr->total_parts, hdr->image_count);
 129
 130         if (hdr->image_count >= INT_MAX) {
 131                 ERROR("Invalid image count (%u)", hdr->image_count);
 132                 return WIMLIB_ERR_IMAGE_COUNT;
 133         }
 134
 135         /* Byte 48 */
 136
 137         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 138         p = get_resource_entry(p, &hdr->xml_res_entry);
 139         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 140
 141         /* Byte 120 */
 142
 143         p = get_u32(p, &hdr->boot_idx);
 144
 145         /* Byte 124 */
 146
 147         p = get_resource_entry(p, &hdr->integrity);
 148
 149         /* Byte 148 */
 150
 151         /* 60 bytes of unused stuff. */
 152
 153         /* Byte 208 */
 154
 155         return 0;
 156
 157 err:
 158         if (feof(fp))
 159                 ERROR("Unexpected EOF while reading WIM header");
 160         else
 161                 ERROR_WITH_ERRNO("Error reading WIM header");
 162         return WIMLIB_ERR_READ;
 163 }
 164
 165 /*
 166  * Writes the header for a WIM file.
 167  *
 168  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 169  * @out:        The FILE* for the output file, positioned at the appropriate
 170  *              place (the beginning of the file).
 171  * @return:     Zero on success, nonzero on failure.
 172  */
 173 int write_header(const struct wim_header *hdr, FILE *out_fp)
 174 {
 175         u8 buf[WIM_HEADER_DISK_SIZE];
 176         u8 *p;
 177         DEBUG("Writing WIM header.");
 178
 179         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 180         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 181         p = put_u32(p, WIM_VERSION);
 182         p = put_u32(p, hdr->flags);
 183         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 184                                 WIM_CHUNK_SIZE : 0);
 185         /* byte 24 */
 186
 187         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 188         p = put_u16(p, hdr->part_number);
 189
 190         /* byte 40 */
 191
 192         p = put_u16(p, hdr->total_parts);
 193         p = put_u32(p, hdr->image_count);
 194         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 195         p = put_resource_entry(p, &hdr->xml_res_entry);
 196         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 197         p = put_u32(p, hdr->boot_idx);
 198         p = put_resource_entry(p, &hdr->integrity);
 199         memset(p, 0, WIM_UNUSED_LEN);
 200         if (fwrite(buf, 1, sizeof(buf), out_fp) != sizeof(buf)) {
 201                 ERROR_WITH_ERRNO("Failed to write WIM header");
 202                 return WIMLIB_ERR_WRITE;
 203         }
 204         DEBUG("Done writing WIM header");
 205         return 0;
 206 }
 207
 208 /*
 209  * Initializes the header for a WIM file.
 210  */
 211 int init_header(struct wim_header *hdr, int ctype)
 212 {
 213         memset(hdr, 0, sizeof(struct wim_header));
 214         switch (ctype) {
 215         case WIMLIB_COMPRESSION_TYPE_NONE:
 216                 hdr->flags = 0;
 217                 break;
 218         case WIMLIB_COMPRESSION_TYPE_LZX:
 219                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 220                              WIM_HDR_FLAG_COMPRESS_LZX;
 221                 break;
 222         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 223                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 224                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 225                 break;
 226         default:
 227                 ERROR("Invalid compression type specified (%d)", ctype);
 228                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 229         }
 230         hdr->total_parts = 1;
 231         hdr->part_number = 1;
 232         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 233         return 0;
 234 }
 235
 236 struct hdr_flag {
 237         u32 flag;
 238         const char *name;
 239 };
 240 struct hdr_flag hdr_flags[] = {
 241         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 242         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 243         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 244         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 245         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 246         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 247         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 248         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 249         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 250         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 251         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 252 };
 253
 254 /* Prints information from the header of the WIM file associated with @w. */
 255 WIMLIBAPI void wimlib_print_header(const WIMStruct *w)
 256 {
 257         const struct wim_header *hdr = &w->hdr;
 258
 259         printf("Magic Characters            = MSWIM\\000\\000\\000\n");
 260         printf("Header Size                 = %u\n", WIM_HEADER_DISK_SIZE);
 261         printf("Version                     = 0x%x\n", WIM_VERSION);
 262
 263         printf("Flags                       = 0x%x\n", hdr->flags);
 264         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 265                 if (hdr_flags[i].flag & hdr->flags)
 266                         printf("    WIM_HDR_FLAG_%s is set\n", hdr_flags[i].name);
 267
 268         printf("Chunk Size                  = %u\n", WIM_CHUNK_SIZE);
 269         fputs ("GUID                        = ", stdout);
 270         print_byte_field(hdr->guid, WIM_GID_LEN);
 271         putchar('\n');
 272         printf("Part Number                 = %hu\n", w->hdr.part_number);
 273         printf("Total Parts                 = %hu\n", w->hdr.total_parts);
 274         printf("Image Count                 = %u\n", hdr->image_count);
 275         printf("Lookup Table Size           = %"PRIu64"\n",
 276                                 (u64)hdr->lookup_table_res_entry.size);
 277         printf("Lookup Table Flags          = 0x%hhx\n",
 278                                 hdr->lookup_table_res_entry.flags);
 279         printf("Lookup Table Offset         = %"PRIu64"\n",
 280                                 hdr->lookup_table_res_entry.offset);
 281         printf("Lookup Table Original_size  = %"PRIu64"\n",
 282                                 hdr->lookup_table_res_entry.original_size);
 283         printf("XML Data Size               = %"PRIu64"\n",
 284                                 (u64)hdr->xml_res_entry.size);
 285         printf("XML Data Flags              = 0x%hhx\n",
 286                                 hdr->xml_res_entry.flags);
 287         printf("XML Data Offset             = %"PRIu64"\n",
 288                                 hdr->xml_res_entry.offset);
 289         printf("XML Data Original Size      = %"PRIu64"\n",
 290                                 hdr->xml_res_entry.original_size);
 291         printf("Boot Metadata Size          = %"PRIu64"\n",
 292                                 (u64)hdr->boot_metadata_res_entry.size);
 293         printf("Boot Metadata Flags         = 0x%hhx\n",
 294                                 hdr->boot_metadata_res_entry.flags);
 295         printf("Boot Metadata Offset        = %"PRIu64"\n",
 296                                 hdr->boot_metadata_res_entry.offset);
 297         printf("Boot Metadata Original Size = %"PRIu64"\n",
 298                                 hdr->boot_metadata_res_entry.original_size);
 299         printf("Boot Index                  = %u\n", hdr->boot_idx);
 300         printf("Integrity Size              = %"PRIu64"\n",
 301                                         (u64)hdr->integrity.size);
 302         printf("Integrity Flags             = 0x%hhx\n",
 303                                         hdr->integrity.flags);
 304         printf("Integrity Offset            = %"PRIu64"\n",
 305                                         hdr->integrity.offset);
 306         printf("Integrity Original_size     = %"PRIu64"\n",
 307                                         hdr->integrity.original_size);
 308 }