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 #include "wimlib_internal.h"
  27 #include "buffer_io.h"
  28 #include <limits.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 open_flags)
  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         hdr_size = le32_to_cpu(hdr_size);
  65
  66         /* Byte 12 */
  67
  68         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  69                 ERROR("Header is %u bytes (expected %u bytes)",
  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 (hdr->total_parts == 0 ||
 108             hdr->part_number == 0 ||
 109             hdr->part_number > hdr->total_parts)
 110         {
 111                 ERROR("Invalid WIM part number: %hu of %hu",
 112                       hdr->part_number, hdr->total_parts);
 113                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 114         }
 115
 116         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) &&
 117             hdr->total_parts != 1)
 118         {
 119                 ERROR("This WIM is part %u of a %u-part WIM",
 120                       hdr->part_number, hdr->total_parts);
 121                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 122         }
 123
 124         p = get_u32(p, &hdr->image_count);
 125
 126         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 127               hdr->part_number, hdr->total_parts, hdr->image_count);
 128
 129         if (hdr->image_count >= INT_MAX) {
 130                 ERROR("Invalid image count (%u)", hdr->image_count);
 131                 return WIMLIB_ERR_IMAGE_COUNT;
 132         }
 133
 134         /* Byte 48 */
 135
 136         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 137         p = get_resource_entry(p, &hdr->xml_res_entry);
 138         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 139
 140         /* Byte 120 */
 141
 142         p = get_u32(p, &hdr->boot_idx);
 143
 144         /* Byte 124 */
 145
 146         p = get_resource_entry(p, &hdr->integrity);
 147
 148         /* Byte 148 */
 149
 150         /* 60 bytes of unused stuff. */
 151
 152         /* Byte 208 */
 153
 154         return 0;
 155
 156 err:
 157         if (feof(fp))
 158                 ERROR("Unexpected EOF while reading WIM header");
 159         else
 160                 ERROR_WITH_ERRNO("Error reading WIM header");
 161         return WIMLIB_ERR_READ;
 162 }
 163
 164 /*
 165  * Writes the header for a WIM file.
 166  *
 167  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 168  * @out:        The FILE* for the output file, positioned at the appropriate
 169  *              place (the beginning of the file).
 170  * @return:     Zero on success, nonzero on failure.
 171  */
 172 int write_header(const struct wim_header *hdr, FILE *out_fp)
 173 {
 174         u8 buf[WIM_HEADER_DISK_SIZE];
 175         u8 *p;
 176         DEBUG("Writing WIM header.");
 177
 178         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 179         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 180         p = put_u32(p, WIM_VERSION);
 181         p = put_u32(p, hdr->flags);
 182         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 183                                 WIM_CHUNK_SIZE : 0);
 184         /* byte 24 */
 185
 186         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 187         p = put_u16(p, hdr->part_number);
 188
 189         /* byte 40 */
 190
 191         p = put_u16(p, hdr->total_parts);
 192         p = put_u32(p, hdr->image_count);
 193         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 194         p = put_resource_entry(p, &hdr->xml_res_entry);
 195         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 196         p = put_u32(p, hdr->boot_idx);
 197         p = put_resource_entry(p, &hdr->integrity);
 198         memset(p, 0, WIM_UNUSED_LEN);
 199         if (fwrite(buf, 1, sizeof(buf), out_fp) != sizeof(buf)) {
 200                 ERROR_WITH_ERRNO("Failed to write WIM header");
 201                 return WIMLIB_ERR_WRITE;
 202         }
 203         DEBUG("Done writing WIM header");
 204         return 0;
 205 }
 206
 207 /*
 208  * Initializes the header for a WIM file.
 209  */
 210 int init_header(struct wim_header *hdr, int ctype)
 211 {
 212         memset(hdr, 0, sizeof(struct wim_header));
 213         switch (ctype) {
 214         case WIMLIB_COMPRESSION_TYPE_NONE:
 215                 hdr->flags = 0;
 216                 break;
 217         case WIMLIB_COMPRESSION_TYPE_LZX:
 218                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 219                              WIM_HDR_FLAG_COMPRESS_LZX;
 220                 break;
 221         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 222                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 223                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 224                 break;
 225         default:
 226                 ERROR("Invalid compression type specified (%d)", ctype);
 227                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 228         }
 229         hdr->total_parts = 1;
 230         hdr->part_number = 1;
 231         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 232         return 0;
 233 }
 234
 235 struct hdr_flag {
 236         u32 flag;
 237         const char *name;
 238 };
 239 struct hdr_flag hdr_flags[] = {
 240         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 241         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 242         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 243         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 244         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 245         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 246         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 247         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 248         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 249         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 250         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 251 };
 252
 253 /* Prints information from the header of the WIM file associated with @w. */
 254 WIMLIBAPI void wimlib_print_header(const WIMStruct *w)
 255 {
 256         const struct wim_header *hdr = &w->hdr;
 257
 258         printf("Magic Characters            = MSWIM\\000\\000\\000\n");
 259         printf("Header Size                 = %u\n", WIM_HEADER_DISK_SIZE);
 260         printf("Version                     = 0x%x\n", WIM_VERSION);
 261
 262         printf("Flags                       = 0x%x\n", hdr->flags);
 263         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 264                 if (hdr_flags[i].flag & hdr->flags)
 265                         printf("    WIM_HDR_FLAG_%s is set\n", hdr_flags[i].name);
 266
 267         printf("Chunk Size                  = %u\n", WIM_CHUNK_SIZE);
 268         fputs ("GUID                        = ", stdout);
 269         print_byte_field(hdr->guid, WIM_GID_LEN);
 270         putchar('\n');
 271         printf("Part Number                 = %hu\n", w->hdr.part_number);
 272         printf("Total Parts                 = %hu\n", w->hdr.total_parts);
 273         printf("Image Count                 = %u\n", hdr->image_count);
 274         printf("Lookup Table Size           = %"PRIu64"\n",
 275                                 (u64)hdr->lookup_table_res_entry.size);
 276         printf("Lookup Table Flags          = 0x%hhx\n",
 277                                 hdr->lookup_table_res_entry.flags);
 278         printf("Lookup Table Offset         = %"PRIu64"\n",
 279                                 hdr->lookup_table_res_entry.offset);
 280         printf("Lookup Table Original_size  = %"PRIu64"\n",
 281                                 hdr->lookup_table_res_entry.original_size);
 282         printf("XML Data Size               = %"PRIu64"\n",
 283                                 (u64)hdr->xml_res_entry.size);
 284         printf("XML Data Flags              = 0x%hhx\n",
 285                                 hdr->xml_res_entry.flags);
 286         printf("XML Data Offset             = %"PRIu64"\n",
 287                                 hdr->xml_res_entry.offset);
 288         printf("XML Data Original Size      = %"PRIu64"\n",
 289                                 hdr->xml_res_entry.original_size);
 290         printf("Boot Metadata Size          = %"PRIu64"\n",
 291                                 (u64)hdr->boot_metadata_res_entry.size);
 292         printf("Boot Metadata Flags         = 0x%hhx\n",
 293                                 hdr->boot_metadata_res_entry.flags);
 294         printf("Boot Metadata Offset        = %"PRIu64"\n",
 295                                 hdr->boot_metadata_res_entry.offset);
 296         printf("Boot Metadata Original Size = %"PRIu64"\n",
 297                                 hdr->boot_metadata_res_entry.original_size);
 298         printf("Boot Index                  = %u\n", hdr->boot_idx);
 299         printf("Integrity Size              = %"PRIu64"\n",
 300                                         (u64)hdr->integrity.size);
 301         printf("Integrity Flags             = 0x%hhx\n",
 302                                         hdr->integrity.flags);
 303         printf("Integrity Offset            = %"PRIu64"\n",
 304                                         hdr->integrity.offset);
 305         printf("Integrity Original_size     = %"PRIu64"\n",
 306                                         hdr->integrity.original_size);
 307 }