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
  36 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->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
 174 write_header(const struct wim_header *hdr, FILE *out_fp)
 175 {
 176         u8 buf[WIM_HEADER_DISK_SIZE];
 177         u8 *p;
 178         DEBUG("Writing WIM header.");
 179
 180         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 181         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 182         p = put_u32(p, WIM_VERSION);
 183         p = put_u32(p, hdr->flags);
 184         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 185                                 WIM_CHUNK_SIZE : 0);
 186         /* byte 24 */
 187
 188         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 189         p = put_u16(p, hdr->part_number);
 190
 191         /* byte 40 */
 192
 193         p = put_u16(p, hdr->total_parts);
 194         p = put_u32(p, hdr->image_count);
 195         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 196         p = put_resource_entry(p, &hdr->xml_res_entry);
 197         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 198         p = put_u32(p, hdr->boot_idx);
 199         p = put_resource_entry(p, &hdr->integrity);
 200         memset(p, 0, WIM_UNUSED_LEN);
 201         if (fwrite(buf, 1, sizeof(buf), out_fp) != sizeof(buf)) {
 202                 ERROR_WITH_ERRNO("Failed to write WIM header");
 203                 return WIMLIB_ERR_WRITE;
 204         }
 205         DEBUG("Done writing WIM header");
 206         return 0;
 207 }
 208
 209 /*
 210  * Initializes the header for a WIM file.
 211  */
 212 int
 213 init_header(struct wim_header *hdr, int ctype)
 214 {
 215         memset(hdr, 0, sizeof(struct wim_header));
 216         switch (ctype) {
 217         case WIMLIB_COMPRESSION_TYPE_NONE:
 218                 hdr->flags = 0;
 219                 break;
 220         case WIMLIB_COMPRESSION_TYPE_LZX:
 221                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 222                              WIM_HDR_FLAG_COMPRESS_LZX;
 223                 break;
 224         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 225                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 226                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 227                 break;
 228         default:
 229                 ERROR("Invalid compression type specified (%d)", ctype);
 230                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 231         }
 232         hdr->total_parts = 1;
 233         hdr->part_number = 1;
 234         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 235         return 0;
 236 }
 237
 238 struct hdr_flag {
 239         u32 flag;
 240         const char *name;
 241 };
 242 struct hdr_flag hdr_flags[] = {
 243         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 244         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 245         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 246         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 247         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 248         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 249         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 250         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 251         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 252         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 253         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 254 };
 255
 256 /* Prints information from the header of the WIM file associated with @w. */
 257 WIMLIBAPI void
 258 wimlib_print_header(const WIMStruct *w)
 259 {
 260         const struct wim_header *hdr = &w->hdr;
 261
 262         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 263         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 264         tprintf(T("Version                     = 0x%x\n"), WIM_VERSION);
 265
 266         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 267         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 268                 if (hdr_flags[i].flag & hdr->flags)
 269                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 270
 271         tprintf(T("Chunk Size                  = %u\n"), WIM_CHUNK_SIZE);
 272         tfputs (T("GUID                        = "), stdout);
 273         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 274         tputchar(T('\n'));
 275         tprintf(T("Part Number                 = %hu\n"), w->hdr.part_number);
 276         tprintf(T("Total Parts                 = %hu\n"), w->hdr.total_parts);
 277         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 278         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 279                                 (u64)hdr->lookup_table_res_entry.size);
 280         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 281                                 (u8)hdr->lookup_table_res_entry.flags);
 282         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 283                                 hdr->lookup_table_res_entry.offset);
 284         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 285                                 hdr->lookup_table_res_entry.original_size);
 286         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 287                                 (u64)hdr->xml_res_entry.size);
 288         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 289                                 (u8)hdr->xml_res_entry.flags);
 290         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 291                                 hdr->xml_res_entry.offset);
 292         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 293                                 hdr->xml_res_entry.original_size);
 294         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 295                                 (u64)hdr->boot_metadata_res_entry.size);
 296         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 297                                 (u8)hdr->boot_metadata_res_entry.flags);
 298         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 299                                 hdr->boot_metadata_res_entry.offset);
 300         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 301                                 hdr->boot_metadata_res_entry.original_size);
 302         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 303         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 304                                 (u64)hdr->integrity.size);
 305         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 306                                 (u8)hdr->integrity.flags);
 307         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 308                                 hdr->integrity.offset);
 309         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 310                                 hdr->integrity.original_size);
 311 }