wimlib.net Git - wimlib/blob - src/header.c

   1 /*
   2  * header.c
   3  *
   4  * Read, write, or create a WIM header.
   5  *
   6  * Copyright (C) 2010 Carl Thijssen
   7  * Copyright (C) 2012 Eric Biggers
   8  *
   9  * wimlib - Library for working with WIM files
  10  *
  11  * This library is free software; you can redistribute it and/or modify it under
  12  * the terms of the GNU Lesser General Public License as published by the Free
  13  * Software Foundation; either version 2.1 of the License, or (at your option) any
  14  * later version.
  15  *
  16  * This library is distributed in the hope that it will be useful, but WITHOUT ANY
  17  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
  18  * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License along
  21  * with this library; if not, write to the Free Software Foundation, Inc., 59
  22  * Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24
  25 #include "wimlib_internal.h"
  26 #include "io.h"
  27
  28 /* First 8 bytes in every WIM file. */
  29 static const u8 wim_magic_chars[WIM_MAGIC_LEN] = {
  30                         'M', 'S', 'W', 'I', 'M', '\0', '\0', '\0' };
  31
  32 /* Reads the header for a WIM file.  */
  33 int read_header(FILE *fp, struct wim_header *hdr)
  34 {
  35         size_t bytes_read;
  36         u8 buf[WIM_HEADER_DISK_SIZE];
  37         size_t hdr_rem_size;
  38         const u8 *p;
  39
  40         u32 hdr_size;
  41         u32 wim_version;
  42         u32 chunk_size;
  43         u16 part_number;
  44         u16 total_parts;
  45
  46         DEBUG("Reading WIM header.\n");
  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\n");
  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)\n",
  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.\n", wim_version,
  88                                                                 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                                 "(Or it might just be that the WIM header is "
  99                                 "invalid.)\n", chunk_size);
 100                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 101         }
 102
 103         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
 104         p = get_u16(p, &part_number);
 105         p = get_u16(p, &total_parts);
 106
 107         if (part_number != 1 || total_parts != 1) {
 108                 ERROR("Error: This WIM is part %u of a %u-part WIM.  Wimlib "
 109                                 "does not support multi-part (split/spanned) "
 110                                 "WIMs.\n", part_number, total_parts);
 111                 return WIMLIB_ERR_SPLIT;
 112         }
 113
 114         p = get_u32(p, &hdr->image_count);
 115
 116         /* Byte 48 */
 117
 118         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 119         p = get_resource_entry(p, &hdr->xml_res_entry);
 120         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 121
 122         /* Byte 120 */
 123
 124         p = get_u32(p, &hdr->boot_idx);
 125
 126         /* Byte 124 */
 127
 128         p = get_resource_entry(p, &hdr->integrity);
 129
 130         /* Byte 148 */
 131
 132         /* 60 bytes of unused stuff. */
 133
 134         /* Byte 208 */
 135
 136         return 0;
 137
 138 err:
 139         if (feof(fp))
 140                 ERROR("Unexpected EOF while reading WIM header!\n");
 141         else
 142                 ERROR("Error reading WIM header: %m\n");
 143         return WIMLIB_ERR_READ;
 144 }
 145
 146 /*
 147  * Writes the header for a WIM file.
 148  *
 149  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 150  * @out:        The FILE* for the output file, positioned at the appropriate
 151  *              place (the beginning of the file).
 152  * @return:     True on success, false on failure.
 153  */
 154 int write_header(const struct wim_header *hdr, FILE *out)
 155 {
 156         u8 buf[WIM_HEADER_DISK_SIZE];
 157         u8 *p;
 158         DEBUG("Writing WIM header.\n");
 159
 160         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 161         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 162         p = put_u32(p, WIM_VERSION);
 163         p = put_u32(p, hdr->flags);
 164         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 165                                 WIM_CHUNK_SIZE : 0);
 166         randomize_byte_array(p, WIM_GID_LEN);
 167         p += WIM_GID_LEN;
 168         p = put_u16(p, 1);
 169         p = put_u16(p, 1);
 170         p = put_u32(p, hdr->image_count);
 171         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 172         p = put_resource_entry(p, &hdr->xml_res_entry);
 173         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 174         p = put_u32(p, hdr->boot_idx);
 175         p = put_resource_entry(p, &hdr->integrity);
 176         memset(p, 0, WIM_UNUSED_LEN);
 177         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 178                 DEBUG("Failed to write WIM header: %m\n");
 179                 return WIMLIB_ERR_WRITE;
 180         }
 181         return 0;
 182 }
 183
 184 /*
 185  * Initializes the header for a WIM file.
 186  */
 187 int init_header(struct wim_header *hdr, int ctype)
 188 {
 189         memset(hdr, 0, sizeof(struct wim_header));
 190         switch (ctype) {
 191         case WIM_COMPRESSION_TYPE_NONE:
 192                 hdr->flags = 0;
 193                 break;
 194         case WIM_COMPRESSION_TYPE_LZX:
 195                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 196                         WIM_HDR_FLAG_COMPRESS_LZX;
 197                 break;
 198         case WIM_COMPRESSION_TYPE_XPRESS:
 199                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 200                         WIM_HDR_FLAG_COMPRESS_XPRESS;
 201                 break;
 202         default:
 203                 ERROR("Invalid compression type specified (%d)!\n", ctype);
 204                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 205         }
 206         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 207         return 0;
 208 }
 209
 210 /* Prints information from the header of the WIM file associated with @w. */
 211 WIMLIBAPI void wimlib_print_header(const WIMStruct *w)
 212 {
 213         const struct wim_header *hdr = &w->hdr;
 214         printf("Magic Characters            = MSWIM\\000\\000\\000\n");
 215         printf("Header Size                 = %u\n", WIM_HEADER_DISK_SIZE);
 216         printf("Version                     = 0x%x\n", WIM_VERSION);
 217         printf("Flags                       = 0x%x\n", hdr->flags);
 218
 219         if (hdr->flags & WIM_HDR_FLAG_COMPRESS_XPRESS)
 220                 printf("    COMPRESS XPRESS FLAG is set\n");
 221
 222         if (hdr->flags & WIM_HDR_FLAG_COMPRESS_LZX)
 223                 printf("    COMPRESS LZX FLAG is set\n");
 224
 225         printf("Chunk Size                  = %u\n", WIM_CHUNK_SIZE);
 226         fputs ("GUID                        = ", stdout);
 227         print_byte_field(hdr->guid, WIM_GID_LEN);
 228         putchar('\n');
 229         printf("Part Number                 = %hu\n", 1);
 230         printf("Total Parts                 = %hu\n", 1);
 231         printf("Image Count                 = %u\n", hdr->image_count);
 232         printf("Lookup Table Size           = %"PRIu64"\n",
 233                                 (u64)hdr->lookup_table_res_entry.size);
 234         printf("Lookup Table Flags          = 0x%hhx\n",
 235                                 hdr->lookup_table_res_entry.flags);
 236         printf("Lookup Table Offset         = %"PRIu64"\n",
 237                                 hdr->lookup_table_res_entry.offset);
 238         printf("Lookup Table Original_size  = %"PRIu64"\n",
 239                                 hdr->lookup_table_res_entry.original_size);
 240         printf("XML Data Size               = %"PRIu64"\n",
 241                                 (u64)hdr->xml_res_entry.size);
 242         printf("XML Data Flags              = 0x%hhx\n",
 243                                 hdr->xml_res_entry.flags);
 244         printf("XML Data Offset             = %"PRIu64"\n",
 245                                 hdr->xml_res_entry.offset);
 246         printf("XML Data Original Size      = %"PRIu64"\n",
 247                                 hdr->xml_res_entry.original_size);
 248         printf("Boot Metadata Size          = %"PRIu64"\n",
 249                                 (u64)hdr->boot_metadata_res_entry.size);
 250         printf("Boot Metadata Flags         = 0x%hhx\n",
 251                                 hdr->boot_metadata_res_entry.flags);
 252         printf("Boot Metadata Offset        = %"PRIu64"\n",
 253                                 hdr->boot_metadata_res_entry.offset);
 254         printf("Boot Metadata Original Size = %"PRIu64"\n",
 255                                 hdr->boot_metadata_res_entry.original_size);
 256         printf("Boot Index                  = %u\n", hdr->boot_idx);
 257         printf("Integrity Size              = %"PRIu64"\n",
 258                                         (u64)hdr->integrity.size);
 259         printf("Integrity Flags             = 0x%hhx\n",
 260                                         hdr->integrity.flags);
 261         printf("Integrity Offset            = %"PRIu64"\n",
 262                                         hdr->integrity.offset);
 263         printf("Integrity Original_size     = %"PRIu64"\n",
 264                                         hdr->integrity.original_size);
 265 }