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 from a WIM file.  */
  35 int
  36 read_header(filedes_t in_fd, struct wim_header *hdr, int open_flags)
  37 {
  38         size_t bytes_read;
  39         u8 buf[WIM_HEADER_DISK_SIZE];
  40         const void *p;
  41
  42         u32 hdr_size;
  43         u32 wim_version;
  44         u32 chunk_size;
  45
  46         DEBUG("Reading WIM header.");
  47
  48         bytes_read = full_pread(in_fd, buf, WIM_HEADER_DISK_SIZE, 0);
  49
  50         if (bytes_read != WIM_HEADER_DISK_SIZE) {
  51                 ERROR_WITH_ERRNO("Error reading WIM header");
  52                 return WIMLIB_ERR_READ;
  53         }
  54
  55         p = buf;
  56         if (memcmp(p, wim_magic_chars, WIM_MAGIC_LEN)) {
  57                 ERROR("Invalid magic characters in WIM header");
  58                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  59         }
  60
  61         /* Byte 8 */
  62         p = get_u32(p + 8, &hdr_size);
  63         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  64                 ERROR("Header is %u bytes (expected %u bytes)",
  65                       hdr_size, WIM_HEADER_DISK_SIZE);
  66                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  67         }
  68
  69         /* Byte 12 */
  70         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  71         if (wim_version != WIM_VERSION) {
  72                 ERROR("The WIM header says the WIM version is %u, but wimlib "
  73                       "only knows about version %u",
  74                       wim_version, WIM_VERSION);
  75                 return WIMLIB_ERR_UNKNOWN_VERSION;
  76         }
  77
  78         p = get_u32(p, &hdr->flags);
  79         p = get_u32(p, &chunk_size);
  80         if (chunk_size != WIM_CHUNK_SIZE &&
  81             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  82                 ERROR("Unexpected chunk size of %u! Ask the author to "
  83                       "implement support for other chunk sizes.",
  84                       chunk_size);
  85                 ERROR("(Or it might just be that the WIM header is invalid.)");
  86                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
  87         }
  88
  89         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
  90         p = get_u16(p, &hdr->part_number);
  91         p = get_u16(p, &hdr->total_parts);
  92
  93         if (hdr->total_parts == 0 ||
  94             hdr->part_number == 0 ||
  95             hdr->part_number > hdr->total_parts)
  96         {
  97                 ERROR("Invalid WIM part number: %hu of %hu",
  98                       hdr->part_number, hdr->total_parts);
  99                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 100         }
 101
 102         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) &&
 103             hdr->total_parts != 1)
 104         {
 105                 ERROR("This WIM is part %u of a %u-part WIM",
 106                       hdr->part_number, hdr->total_parts);
 107                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 108         }
 109
 110         p = get_u32(p, &hdr->image_count);
 111
 112         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 113               hdr->part_number, hdr->total_parts, hdr->image_count);
 114
 115         if (hdr->image_count >= INT_MAX) {
 116                 ERROR("Invalid image count (%u)", hdr->image_count);
 117                 return WIMLIB_ERR_IMAGE_COUNT;
 118         }
 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
 143 /*
 144  * Writes the header for a WIM file.
 145  *
 146  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 147  * @out_fd:     The file descriptor to the WIM file, opened for writing.
 148  *
 149  * Returns zero on success, nonzero on failure.
 150  */
 151 int
 152 write_header(const struct wim_header *hdr, int out_fd)
 153 {
 154         u8 buf[WIM_HEADER_DISK_SIZE];
 155         u8 *p;
 156         DEBUG("Writing WIM header.");
 157
 158         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 159         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 160         p = put_u32(p, WIM_VERSION);
 161         p = put_u32(p, hdr->flags);
 162         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 163                                 WIM_CHUNK_SIZE : 0);
 164         /* Byte 24 */
 165
 166         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 167         p = put_u16(p, hdr->part_number);
 168
 169         /* Byte 40 */
 170
 171         p = put_u16(p, hdr->total_parts);
 172         p = put_u32(p, hdr->image_count);
 173         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 174         p = put_resource_entry(p, &hdr->xml_res_entry);
 175         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 176         p = put_u32(p, hdr->boot_idx);
 177         p = put_resource_entry(p, &hdr->integrity);
 178         p = put_zeroes(p, WIM_UNUSED_LEN);
 179         wimlib_assert(p - buf == sizeof(buf));
 180
 181         if (full_pwrite(out_fd, buf, sizeof(buf), 0) != sizeof(buf)) {
 182                 ERROR_WITH_ERRNO("Failed to write WIM header");
 183                 return WIMLIB_ERR_WRITE;
 184         }
 185         DEBUG("Done writing WIM header");
 186         return 0;
 187 }
 188
 189 /*
 190  * Initializes the header for a WIM file.
 191  */
 192 int
 193 init_header(struct wim_header *hdr, int ctype)
 194 {
 195         memset(hdr, 0, sizeof(struct wim_header));
 196         switch (ctype) {
 197         case WIMLIB_COMPRESSION_TYPE_NONE:
 198                 hdr->flags = 0;
 199                 break;
 200         case WIMLIB_COMPRESSION_TYPE_LZX:
 201                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 202                              WIM_HDR_FLAG_COMPRESS_LZX;
 203                 break;
 204         case WIMLIB_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
 238 wimlib_print_header(const WIMStruct *w)
 239 {
 240         const struct wim_header *hdr = &w->hdr;
 241
 242         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 243         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 244         tprintf(T("Version                     = 0x%x\n"), WIM_VERSION);
 245
 246         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 247         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 248                 if (hdr_flags[i].flag & hdr->flags)
 249                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 250
 251         tprintf(T("Chunk Size                  = %u\n"), WIM_CHUNK_SIZE);
 252         tfputs (T("GUID                        = "), stdout);
 253         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 254         tputchar(T('\n'));
 255         tprintf(T("Part Number                 = %hu\n"), w->hdr.part_number);
 256         tprintf(T("Total Parts                 = %hu\n"), w->hdr.total_parts);
 257         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 258         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 259                                 (u64)hdr->lookup_table_res_entry.size);
 260         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 261                                 (u8)hdr->lookup_table_res_entry.flags);
 262         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 263                                 hdr->lookup_table_res_entry.offset);
 264         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 265                                 hdr->lookup_table_res_entry.original_size);
 266         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 267                                 (u64)hdr->xml_res_entry.size);
 268         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 269                                 (u8)hdr->xml_res_entry.flags);
 270         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 271                                 hdr->xml_res_entry.offset);
 272         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 273                                 hdr->xml_res_entry.original_size);
 274         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 275                                 (u64)hdr->boot_metadata_res_entry.size);
 276         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 277                                 (u8)hdr->boot_metadata_res_entry.flags);
 278         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 279                                 hdr->boot_metadata_res_entry.offset);
 280         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 281                                 hdr->boot_metadata_res_entry.original_size);
 282         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 283         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 284                                 (u64)hdr->integrity.size);
 285         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 286                                 (u8)hdr->integrity.flags);
 287         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 288                                 hdr->integrity.offset);
 289         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 290                                 hdr->integrity.original_size);
 291 }