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 Lesser General Public License as published by the Free
  15  * Software Foundation; either version 2.1 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 Lesser General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU Lesser 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
  30 /* First 8 bytes in every WIM file. */
  31 static const u8 wim_magic_chars[WIM_MAGIC_LEN] = {
  32                         'M', 'S', 'W', 'I', 'M', '\0', '\0', '\0' };
  33
  34 /* Reads the header for a WIM file.  */
  35 int read_header(FILE *fp, struct wim_header *hdr, int split_ok)
  36 {
  37         size_t bytes_read;
  38         u8 buf[WIM_HEADER_DISK_SIZE];
  39         size_t hdr_rem_size;
  40         const u8 *p;
  41
  42         u32 hdr_size;
  43         u32 wim_version;
  44         u32 chunk_size;
  45
  46         DEBUG("Reading WIM header.");
  47
  48         bytes_read = fread(buf, 1, WIM_MAGIC_LEN, fp);
  49
  50         if (bytes_read != WIM_MAGIC_LEN)
  51                 goto err;
  52
  53         /* Byte 8 */
  54
  55         if (memcmp(buf, wim_magic_chars, WIM_MAGIC_LEN) != 0) {
  56                 ERROR("Invalid magic characters in WIM header");
  57                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  58         }
  59
  60         bytes_read = fread(&hdr_size, 1, sizeof(u32), fp);
  61         if (bytes_read != sizeof(u32))
  62                 goto err;
  63
  64         TO_LE32(hdr_size);
  65
  66         /* Byte 12 */
  67
  68         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  69                 DEBUG("ERROR: Header is size %u (expected %u)",
  70                       hdr_size, WIM_HEADER_DISK_SIZE);
  71                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  72         }
  73
  74         /* Read the rest of the header into a buffer. */
  75
  76         hdr_rem_size = WIM_HEADER_DISK_SIZE - WIM_MAGIC_LEN - sizeof(u32);
  77
  78         bytes_read = fread(buf + WIM_MAGIC_LEN + sizeof(u32), 1,
  79                            hdr_rem_size, fp);
  80         if (bytes_read != hdr_rem_size)
  81                 goto err;
  82
  83         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  84
  85         if (wim_version != WIM_VERSION) {
  86                 ERROR("The WIM header says the WIM version is %u, but wimlib "
  87                       "only knows about version %u",
  88                       wim_version, WIM_VERSION);
  89                 return WIMLIB_ERR_UNKNOWN_VERSION;
  90         }
  91
  92         p = get_u32(p, &hdr->flags);
  93         p = get_u32(p, &chunk_size);
  94         if (chunk_size != WIM_CHUNK_SIZE &&
  95             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  96                 ERROR("Unexpected chunk size of %u! Ask the author to "
  97                       "implement support for other chunk sizes.",
  98                       chunk_size);
  99                 ERROR("(Or it might just be that the WIM header is invalid.)");
 100                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 101         }
 102
 103         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
 104         p = get_u16(p, &hdr->part_number);
 105         p = get_u16(p, &hdr->total_parts);
 106
 107         if (!split_ok && (hdr->part_number != 1 || hdr->total_parts != 1)) {
 108                 ERROR("This WIM is part %u of a %u-part WIM",
 109                       hdr->part_number, hdr->total_parts);
 110                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 111         }
 112
 113         p = get_u32(p, &hdr->image_count);
 114
 115         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 116               hdr->part_number, hdr->total_parts, hdr->image_count);
 117
 118         /* Byte 48 */
 119
 120         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 121         p = get_resource_entry(p, &hdr->xml_res_entry);
 122         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 123
 124         /* Byte 120 */
 125
 126         p = get_u32(p, &hdr->boot_idx);
 127
 128         /* Byte 124 */
 129
 130         p = get_resource_entry(p, &hdr->integrity);
 131
 132         /* Byte 148 */
 133
 134         /* 60 bytes of unused stuff. */
 135
 136         /* Byte 208 */
 137
 138         return 0;
 139
 140 err:
 141         if (feof(fp))
 142                 ERROR("Unexpected EOF while reading WIM header");
 143         else
 144                 ERROR_WITH_ERRNO("Error reading WIM header");
 145         return WIMLIB_ERR_READ;
 146 }
 147
 148 /*
 149  * Writes the header for a WIM file.
 150  *
 151  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 152  * @out:        The FILE* for the output file, positioned at the appropriate
 153  *              place (the beginning of the file).
 154  * @return:     Zero on success, nonzero on failure.
 155  */
 156 int write_header(const struct wim_header *hdr, FILE *out_fp)
 157 {
 158         u8 buf[WIM_HEADER_DISK_SIZE];
 159         u8 *p;
 160         DEBUG("Writing WIM header.");
 161
 162         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 163         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 164         p = put_u32(p, WIM_VERSION);
 165         p = put_u32(p, hdr->flags);
 166         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 167                                 WIM_CHUNK_SIZE : 0);
 168         /* byte 24 */
 169
 170         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 171         p = put_u16(p, hdr->part_number);
 172
 173         /* byte 40 */
 174
 175         p = put_u16(p, hdr->total_parts);
 176         p = put_u32(p, hdr->image_count);
 177         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 178         p = put_resource_entry(p, &hdr->xml_res_entry);
 179         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 180         p = put_u32(p, hdr->boot_idx);
 181         p = put_resource_entry(p, &hdr->integrity);
 182         memset(p, 0, WIM_UNUSED_LEN);
 183         if (fwrite(buf, 1, sizeof(buf), out_fp) != sizeof(buf)) {
 184                 ERROR_WITH_ERRNO("Failed to write WIM header");
 185                 return WIMLIB_ERR_WRITE;
 186         }
 187         return 0;
 188 }
 189
 190 /*
 191  * Initializes the header for a WIM file.
 192  */
 193 int init_header(struct wim_header *hdr, int ctype)
 194 {
 195         memset(hdr, 0, sizeof(struct wim_header));
 196         switch (ctype) {
 197         case WIM_COMPRESSION_TYPE_NONE:
 198                 hdr->flags = 0;
 199                 break;
 200         case WIM_COMPRESSION_TYPE_LZX:
 201                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 202                              WIM_HDR_FLAG_COMPRESS_LZX;
 203                 break;
 204         case WIM_COMPRESSION_TYPE_XPRESS:
 205                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 206                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 207                 break;
 208         default:
 209                 ERROR("Invalid compression type specified (%d)", ctype);
 210                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 211         }
 212         hdr->total_parts = 1;
 213         hdr->part_number = 1;
 214         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 215         return 0;
 216 }
 217
 218 struct hdr_flag {
 219         u32 flag;
 220         const char *name;
 221 };
 222 struct hdr_flag hdr_flags[] = {
 223         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 224         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 225         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 226         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 227         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 228         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 229         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 230         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 231         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 232         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 233         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 234 };
 235
 236 /* Prints information from the header of the WIM file associated with @w. */
 237 WIMLIBAPI void wimlib_print_header(const WIMStruct *w)
 238 {
 239         const struct wim_header *hdr = &w->hdr;
 240         uint i;
 241
 242         printf("Magic Characters            = MSWIM\\000\\000\\000\n");
 243         printf("Header Size                 = %u\n", WIM_HEADER_DISK_SIZE);
 244         printf("Version                     = 0x%x\n", WIM_VERSION);
 245
 246         printf("Flags                       = 0x%x\n", hdr->flags);
 247         for (i = 0; i < ARRAY_LEN(hdr_flags); i++)
 248                 if (hdr_flags[i].flag & hdr->flags)
 249                         printf("    WIM_HDR_FLAG_%s is set\n", hdr_flags[i].name);
 250
 251         printf("Chunk Size                  = %u\n", WIM_CHUNK_SIZE);
 252         fputs ("GUID                        = ", stdout);
 253         print_byte_field(hdr->guid, WIM_GID_LEN);
 254         putchar('\n');
 255         printf("Part Number                 = %hu\n", 1);
 256         printf("Total Parts                 = %hu\n", 1);
 257         printf("Image Count                 = %u\n", hdr->image_count);
 258         printf("Lookup Table Size           = %"PRIu64"\n",
 259                                 (u64)hdr->lookup_table_res_entry.size);
 260         printf("Lookup Table Flags          = 0x%hhx\n",
 261                                 hdr->lookup_table_res_entry.flags);
 262         printf("Lookup Table Offset         = %"PRIu64"\n",
 263                                 hdr->lookup_table_res_entry.offset);
 264         printf("Lookup Table Original_size  = %"PRIu64"\n",
 265                                 hdr->lookup_table_res_entry.original_size);
 266         printf("XML Data Size               = %"PRIu64"\n",
 267                                 (u64)hdr->xml_res_entry.size);
 268         printf("XML Data Flags              = 0x%hhx\n",
 269                                 hdr->xml_res_entry.flags);
 270         printf("XML Data Offset             = %"PRIu64"\n",
 271                                 hdr->xml_res_entry.offset);
 272         printf("XML Data Original Size      = %"PRIu64"\n",
 273                                 hdr->xml_res_entry.original_size);
 274         printf("Boot Metadata Size          = %"PRIu64"\n",
 275                                 (u64)hdr->boot_metadata_res_entry.size);
 276         printf("Boot Metadata Flags         = 0x%hhx\n",
 277                                 hdr->boot_metadata_res_entry.flags);
 278         printf("Boot Metadata Offset        = %"PRIu64"\n",
 279                                 hdr->boot_metadata_res_entry.offset);
 280         printf("Boot Metadata Original Size = %"PRIu64"\n",
 281                                 hdr->boot_metadata_res_entry.original_size);
 282         printf("Boot Index                  = %u\n", hdr->boot_idx);
 283         printf("Integrity Size              = %"PRIu64"\n",
 284                                         (u64)hdr->integrity.size);
 285         printf("Integrity Flags             = 0x%hhx\n",
 286                                         hdr->integrity.flags);
 287         printf("Integrity Offset            = %"PRIu64"\n",
 288                                         hdr->integrity.offset);
 289         printf("Integrity Original_size     = %"PRIu64"\n",
 290                                         hdr->integrity.original_size);
 291 }