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         u16 part_number;
  46         u16 total_parts;
  47
  48         DEBUG("Reading WIM header.\n");
  49
  50         bytes_read = fread(buf, 1, WIM_MAGIC_LEN, fp);
  51
  52         if (bytes_read != WIM_MAGIC_LEN)
  53                 goto err;
  54
  55         /* Byte 8 */
  56
  57         if (memcmp(buf, wim_magic_chars, WIM_MAGIC_LEN) != 0) {
  58                 ERROR("Invalid magic characters in WIM header\n");
  59                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  60         }
  61
  62         bytes_read = fread(&hdr_size, 1, sizeof(u32), fp);
  63         if (bytes_read != sizeof(u32))
  64                 goto err;
  65
  66         TO_LE32(hdr_size);
  67
  68         /* Byte 12 */
  69
  70         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  71                 DEBUG("ERROR: Header is size %u (expected %u)\n",
  72                                 hdr_size, WIM_HEADER_DISK_SIZE);
  73                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  74         }
  75
  76         /* Read the rest of the header into a buffer. */
  77
  78         hdr_rem_size = WIM_HEADER_DISK_SIZE - WIM_MAGIC_LEN - sizeof(u32);
  79
  80         bytes_read = fread(buf + WIM_MAGIC_LEN + sizeof(u32), 1,
  81                            hdr_rem_size, fp);
  82         if (bytes_read != hdr_rem_size)
  83                 goto err;
  84
  85         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  86
  87         if (wim_version != WIM_VERSION) {
  88                 ERROR("The WIM header says the WIM version is %u, but Wimlib "
  89                         "only knows about version %u.\n", wim_version,
  90                                                                 WIM_VERSION);
  91                 return WIMLIB_ERR_UNKNOWN_VERSION;
  92         }
  93
  94         p = get_u32(p, &hdr->flags);
  95         p = get_u32(p, &chunk_size);
  96         if (chunk_size != WIM_CHUNK_SIZE &&
  97                         (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  98                 ERROR("Unexpected chunk size of %u! Ask the author to "
  99                                 "implement support for other chunk sizes. "
 100                                 "(Or it might just be that the WIM header is "
 101                                 "invalid.)\n", chunk_size);
 102                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
 103         }
 104
 105         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
 106         p = get_u16(p, &hdr->part_number);
 107         p = get_u16(p, &hdr->total_parts);
 108
 109         if (!split_ok && (hdr->part_number != 1 || hdr->total_parts != 1)) {
 110                 ERROR("This WIM is part %u of a %u-part WIM.\n",
 111                         hdr->part_number, hdr->total_parts);
 112                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 113         }
 114
 115         p = get_u32(p, &hdr->image_count);
 116
 117         DEBUG("part_number = %u, total_parts = %u, image_count = %u\n",
 118                         hdr->part_number, hdr->total_parts, hdr->image_count);
 119
 120         /* Byte 48 */
 121
 122         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 123         p = get_resource_entry(p, &hdr->xml_res_entry);
 124         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 125
 126         /* Byte 120 */
 127
 128         p = get_u32(p, &hdr->boot_idx);
 129
 130         /* Byte 124 */
 131
 132         p = get_resource_entry(p, &hdr->integrity);
 133
 134         /* Byte 148 */
 135
 136         /* 60 bytes of unused stuff. */
 137
 138         /* Byte 208 */
 139
 140         return 0;
 141
 142 err:
 143         if (feof(fp))
 144                 ERROR("Unexpected EOF while reading WIM header!\n");
 145         else
 146                 ERROR("Error reading WIM header: %m\n");
 147         return WIMLIB_ERR_READ;
 148 }
 149
 150 /*
 151  * Writes the header for a WIM file.
 152  *
 153  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 154  * @out:        The FILE* for the output file, positioned at the appropriate
 155  *              place (the beginning of the file).
 156  * @return:     True on success, false on failure.
 157  */
 158 int write_header(const struct wim_header *hdr, FILE *out)
 159 {
 160         u8 buf[WIM_HEADER_DISK_SIZE];
 161         u8 *p;
 162         DEBUG("Writing WIM header.\n");
 163
 164         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 165         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 166         p = put_u32(p, WIM_VERSION);
 167         p = put_u32(p, hdr->flags);
 168         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 169                                 WIM_CHUNK_SIZE : 0);
 170         /* byte 24 */
 171
 172         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 173         p = put_u16(p, hdr->part_number);
 174
 175         /* byte 40 */
 176
 177         p = put_u16(p, hdr->total_parts);
 178         p = put_u32(p, hdr->image_count);
 179         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 180         p = put_resource_entry(p, &hdr->xml_res_entry);
 181         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 182         p = put_u32(p, hdr->boot_idx);
 183         p = put_resource_entry(p, &hdr->integrity);
 184         memset(p, 0, WIM_UNUSED_LEN);
 185         if (fwrite(buf, 1, sizeof(buf), out) != sizeof(buf)) {
 186                 DEBUG("Failed to write WIM header: %m\n");
 187                 return WIMLIB_ERR_WRITE;
 188         }
 189         return 0;
 190 }
 191
 192 /*
 193  * Initializes the header for a WIM file.
 194  */
 195 int init_header(struct wim_header *hdr, int ctype)
 196 {
 197         memset(hdr, 0, sizeof(struct wim_header));
 198         switch (ctype) {
 199         case WIM_COMPRESSION_TYPE_NONE:
 200                 hdr->flags = 0;
 201                 break;
 202         case WIM_COMPRESSION_TYPE_LZX:
 203                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 204                         WIM_HDR_FLAG_COMPRESS_LZX;
 205                 break;
 206         case WIM_COMPRESSION_TYPE_XPRESS:
 207                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 208                         WIM_HDR_FLAG_COMPRESS_XPRESS;
 209                 break;
 210         default:
 211                 ERROR("Invalid compression type specified (%d)!\n", ctype);
 212                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 213         }
 214         hdr->total_parts = 1;
 215         hdr->part_number = 1;
 216         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 217         return 0;
 218 }
 219
 220 struct hdr_flag {
 221         u32 flag;
 222         const char *name;
 223 };
 224 struct hdr_flag hdr_flags[] = {
 225         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 226         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 227         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 228         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 229         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 230         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 231         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 232         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 233         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 234         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 235         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 236 };
 237
 238 /* Prints information from the header of the WIM file associated with @w. */
 239 WIMLIBAPI void wimlib_print_header(const WIMStruct *w)
 240 {
 241         const struct wim_header *hdr = &w->hdr;
 242         uint i;
 243
 244         printf("Magic Characters            = MSWIM\\000\\000\\000\n");
 245         printf("Header Size                 = %u\n", WIM_HEADER_DISK_SIZE);
 246         printf("Version                     = 0x%x\n", WIM_VERSION);
 247
 248         printf("Flags                       = 0x%x\n", hdr->flags);
 249         for (i = 0; i < ARRAY_LEN(hdr_flags); i++)
 250                 if (hdr_flags[i].flag & hdr->flags)
 251                         printf("    WIM_HDR_FLAG_%s is set\n", hdr_flags[i].name);
 252
 253         printf("Chunk Size                  = %u\n", WIM_CHUNK_SIZE);
 254         fputs ("GUID                        = ", stdout);
 255         print_byte_field(hdr->guid, WIM_GID_LEN);
 256         putchar('\n');
 257         printf("Part Number                 = %hu\n", 1);
 258         printf("Total Parts                 = %hu\n", 1);
 259         printf("Image Count                 = %u\n", hdr->image_count);
 260         printf("Lookup Table Size           = %"PRIu64"\n",
 261                                 (u64)hdr->lookup_table_res_entry.size);
 262         printf("Lookup Table Flags          = 0x%hhx\n",
 263                                 hdr->lookup_table_res_entry.flags);
 264         printf("Lookup Table Offset         = %"PRIu64"\n",
 265                                 hdr->lookup_table_res_entry.offset);
 266         printf("Lookup Table Original_size  = %"PRIu64"\n",
 267                                 hdr->lookup_table_res_entry.original_size);
 268         printf("XML Data Size               = %"PRIu64"\n",
 269                                 (u64)hdr->xml_res_entry.size);
 270         printf("XML Data Flags              = 0x%hhx\n",
 271                                 hdr->xml_res_entry.flags);
 272         printf("XML Data Offset             = %"PRIu64"\n",
 273                                 hdr->xml_res_entry.offset);
 274         printf("XML Data Original Size      = %"PRIu64"\n",
 275                                 hdr->xml_res_entry.original_size);
 276         printf("Boot Metadata Size          = %"PRIu64"\n",
 277                                 (u64)hdr->boot_metadata_res_entry.size);
 278         printf("Boot Metadata Flags         = 0x%hhx\n",
 279                                 hdr->boot_metadata_res_entry.flags);
 280         printf("Boot Metadata Offset        = %"PRIu64"\n",
 281                                 hdr->boot_metadata_res_entry.offset);
 282         printf("Boot Metadata Original Size = %"PRIu64"\n",
 283                                 hdr->boot_metadata_res_entry.original_size);
 284         printf("Boot Index                  = %u\n", hdr->boot_idx);
 285         printf("Integrity Size              = %"PRIu64"\n",
 286                                         (u64)hdr->integrity.size);
 287         printf("Integrity Flags             = 0x%hhx\n",
 288                                         hdr->integrity.flags);
 289         printf("Integrity Offset            = %"PRIu64"\n",
 290                                         hdr->integrity.offset);
 291         printf("Integrity Original_size     = %"PRIu64"\n",
 292                                         hdr->integrity.original_size);
 293 }