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(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 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 = full_read(in_fd, buf, WIM_HEADER_DISK_SIZE);
  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         /* Byte 8 */
  56
  57         p = buf;
  58
  59         if (memcmp(p, wim_magic_chars, WIM_MAGIC_LEN)) {
  60                 ERROR("Invalid magic characters in WIM header");
  61                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  62         }
  63
  64         p += 8;
  65         p = get_u32(p, &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         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  76
  77         if (wim_version != WIM_VERSION) {
  78                 ERROR("The WIM header says the WIM version is %u, but wimlib "
  79                       "only knows about version %u",
  80                       wim_version, WIM_VERSION);
  81                 return WIMLIB_ERR_UNKNOWN_VERSION;
  82         }
  83
  84         p = get_u32(p, &hdr->flags);
  85         p = get_u32(p, &chunk_size);
  86         if (chunk_size != WIM_CHUNK_SIZE &&
  87             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  88                 ERROR("Unexpected chunk size of %u! Ask the author to "
  89                       "implement support for other chunk sizes.",
  90                       chunk_size);
  91                 ERROR("(Or it might just be that the WIM header is invalid.)");
  92                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
  93         }
  94
  95         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
  96         p = get_u16(p, &hdr->part_number);
  97         p = get_u16(p, &hdr->total_parts);
  98
  99         if (hdr->total_parts == 0 ||
 100             hdr->part_number == 0 ||
 101             hdr->part_number > hdr->total_parts)
 102         {
 103                 ERROR("Invalid WIM part number: %hu of %hu",
 104                       hdr->part_number, hdr->total_parts);
 105                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 106         }
 107
 108         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) &&
 109             hdr->total_parts != 1)
 110         {
 111                 ERROR("This WIM is part %u of a %u-part WIM",
 112                       hdr->part_number, hdr->total_parts);
 113                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 114         }
 115
 116         p = get_u32(p, &hdr->image_count);
 117
 118         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 119               hdr->part_number, hdr->total_parts, hdr->image_count);
 120
 121         if (hdr->image_count >= INT_MAX) {
 122                 ERROR("Invalid image count (%u)", hdr->image_count);
 123                 return WIMLIB_ERR_IMAGE_COUNT;
 124         }
 125
 126         /* Byte 48 */
 127
 128         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 129         p = get_resource_entry(p, &hdr->xml_res_entry);
 130         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 131
 132         /* Byte 120 */
 133
 134         p = get_u32(p, &hdr->boot_idx);
 135
 136         /* Byte 124 */
 137
 138         p = get_resource_entry(p, &hdr->integrity);
 139
 140         /* Byte 148 */
 141
 142         /* 60 bytes of unused stuff. */
 143
 144         /* Byte 208 */
 145
 146         return 0;
 147 }
 148
 149 /*
 150  * Writes the header for a WIM file.
 151  *
 152  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 153  * @out_fd:     The file descriptor to the WIM file, opened for writing.
 154  * @return:     Zero on success, nonzero on failure.
 155  */
 156 int
 157 write_header(const struct wim_header *hdr, int out_fd)
 158 {
 159         u8 buf[WIM_HEADER_DISK_SIZE];
 160         u8 *p;
 161         DEBUG("Writing WIM header.");
 162
 163         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 164         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 165         p = put_u32(p, WIM_VERSION);
 166         p = put_u32(p, hdr->flags);
 167         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 168                                 WIM_CHUNK_SIZE : 0);
 169         /* byte 24 */
 170
 171         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 172         p = put_u16(p, hdr->part_number);
 173
 174         /* byte 40 */
 175
 176         p = put_u16(p, hdr->total_parts);
 177         p = put_u32(p, hdr->image_count);
 178         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 179         p = put_resource_entry(p, &hdr->xml_res_entry);
 180         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 181         p = put_u32(p, hdr->boot_idx);
 182         p = put_resource_entry(p, &hdr->integrity);
 183         p = put_zeroes(p, WIM_UNUSED_LEN);
 184         assert(p - buf == sizeof(buf));
 185
 186         if (full_pwrite(out_fd, buf, sizeof(buf), 0) != sizeof(buf)) {
 187                 ERROR_WITH_ERRNO("Failed to write WIM header");
 188                 return WIMLIB_ERR_WRITE;
 189         }
 190         DEBUG("Done writing WIM header");
 191         return 0;
 192 }
 193
 194 /*
 195  * Initializes the header for a WIM file.
 196  */
 197 int
 198 init_header(struct wim_header *hdr, int ctype)
 199 {
 200         memset(hdr, 0, sizeof(struct wim_header));
 201         switch (ctype) {
 202         case WIMLIB_COMPRESSION_TYPE_NONE:
 203                 hdr->flags = 0;
 204                 break;
 205         case WIMLIB_COMPRESSION_TYPE_LZX:
 206                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 207                              WIM_HDR_FLAG_COMPRESS_LZX;
 208                 break;
 209         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 210                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 211                              WIM_HDR_FLAG_COMPRESS_XPRESS;
 212                 break;
 213         default:
 214                 ERROR("Invalid compression type specified (%d)", ctype);
 215                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 216         }
 217         hdr->total_parts = 1;
 218         hdr->part_number = 1;
 219         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 220         return 0;
 221 }
 222
 223 struct hdr_flag {
 224         u32 flag;
 225         const char *name;
 226 };
 227 struct hdr_flag hdr_flags[] = {
 228         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 229         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 230         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 231         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 232         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 233         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 234         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 235         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 236         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 237         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 238         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 239 };
 240
 241 /* Prints information from the header of the WIM file associated with @w. */
 242 WIMLIBAPI void
 243 wimlib_print_header(const WIMStruct *w)
 244 {
 245         const struct wim_header *hdr = &w->hdr;
 246
 247         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 248         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 249         tprintf(T("Version                     = 0x%x\n"), WIM_VERSION);
 250
 251         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 252         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 253                 if (hdr_flags[i].flag & hdr->flags)
 254                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 255
 256         tprintf(T("Chunk Size                  = %u\n"), WIM_CHUNK_SIZE);
 257         tfputs (T("GUID                        = "), stdout);
 258         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 259         tputchar(T('\n'));
 260         tprintf(T("Part Number                 = %hu\n"), w->hdr.part_number);
 261         tprintf(T("Total Parts                 = %hu\n"), w->hdr.total_parts);
 262         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 263         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 264                                 (u64)hdr->lookup_table_res_entry.size);
 265         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 266                                 (u8)hdr->lookup_table_res_entry.flags);
 267         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 268                                 hdr->lookup_table_res_entry.offset);
 269         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 270                                 hdr->lookup_table_res_entry.original_size);
 271         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 272                                 (u64)hdr->xml_res_entry.size);
 273         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 274                                 (u8)hdr->xml_res_entry.flags);
 275         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 276                                 hdr->xml_res_entry.offset);
 277         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 278                                 hdr->xml_res_entry.original_size);
 279         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 280                                 (u64)hdr->boot_metadata_res_entry.size);
 281         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 282                                 (u8)hdr->boot_metadata_res_entry.flags);
 283         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 284                                 hdr->boot_metadata_res_entry.offset);
 285         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 286                                 hdr->boot_metadata_res_entry.original_size);
 287         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 288         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 289                                 (u64)hdr->integrity.size);
 290         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 291                                 (u8)hdr->integrity.flags);
 292         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 293                                 hdr->integrity.offset);
 294         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 295                                 hdr->integrity.original_size);
 296 }