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(const tchar *filename, int in_fd,
  37             struct wim_header *hdr, int open_flags)
  38 {
  39         size_t bytes_read;
  40         u8 buf[WIM_HEADER_DISK_SIZE];
  41         const void *p;
  42
  43         u32 hdr_size;
  44         u32 wim_version;
  45         u32 chunk_size;
  46
  47         DEBUG("Reading WIM header from \"%"TS"\".", filename);
  48
  49         bytes_read = full_pread(in_fd, buf, WIM_HEADER_DISK_SIZE, 0);
  50
  51         if (bytes_read != WIM_HEADER_DISK_SIZE) {
  52                 ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
  53                 return WIMLIB_ERR_READ;
  54         }
  55
  56         p = buf;
  57         if (memcmp(p, wim_magic_chars, WIM_MAGIC_LEN)) {
  58                 ERROR("\"%"TS"\": Invalid magic characters in header", filename);
  59                 return WIMLIB_ERR_NOT_A_WIM_FILE;
  60         }
  61
  62         /* Byte 8 */
  63         p = get_u32(p + 8, &hdr_size);
  64         if (hdr_size != WIM_HEADER_DISK_SIZE) {
  65                 ERROR("\"%"TS"\": Header is %u bytes (expected %u bytes)",
  66                       filename, hdr_size, WIM_HEADER_DISK_SIZE);
  67                 return WIMLIB_ERR_INVALID_HEADER_SIZE;
  68         }
  69
  70         /* Byte 12 */
  71         p = get_u32(buf + WIM_MAGIC_LEN + sizeof(u32), &wim_version);
  72         if (wim_version != WIM_VERSION) {
  73                 ERROR("\"%"TS"\": The WIM header says the WIM version is %u, "
  74                       "but wimlib only knows about version %u",
  75                       filename, wim_version, WIM_VERSION);
  76                 return WIMLIB_ERR_UNKNOWN_VERSION;
  77         }
  78
  79         p = get_u32(p, &hdr->flags);
  80         p = get_u32(p, &chunk_size);
  81         if (chunk_size != WIM_CHUNK_SIZE &&
  82             (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) {
  83                 ERROR("\"%"TS"\": Unexpected chunk size of %u! Ask the author to "
  84                       "implement support for other chunk sizes.",
  85                       filename, chunk_size);
  86                 ERROR("(Or it might just be that the WIM header is invalid.)");
  87                 return WIMLIB_ERR_INVALID_CHUNK_SIZE;
  88         }
  89
  90         p = get_bytes(p, WIM_GID_LEN, hdr->guid);
  91         p = get_u16(p, &hdr->part_number);
  92         p = get_u16(p, &hdr->total_parts);
  93
  94         if (hdr->total_parts == 0 ||
  95             hdr->part_number == 0 ||
  96             hdr->part_number > hdr->total_parts)
  97         {
  98                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
  99                       filename, hdr->part_number, hdr->total_parts);
 100                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 101         }
 102
 103         if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) &&
 104             hdr->total_parts != 1)
 105         {
 106                 ERROR("\"%"TS"\": This WIM is part %u of a %u-part WIM",
 107                       filename, hdr->part_number, hdr->total_parts);
 108                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
 109         }
 110
 111         p = get_u32(p, &hdr->image_count);
 112
 113         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 114               hdr->part_number, hdr->total_parts, hdr->image_count);
 115
 116         if (hdr->image_count >= INT_MAX) {
 117                 ERROR("\"%"TS"\": Invalid image count (%u)",
 118                       filename, hdr->image_count);
 119                 return WIMLIB_ERR_IMAGE_COUNT;
 120         }
 121
 122         /* Byte 48 */
 123
 124         p = get_resource_entry(p, &hdr->lookup_table_res_entry);
 125         p = get_resource_entry(p, &hdr->xml_res_entry);
 126         p = get_resource_entry(p, &hdr->boot_metadata_res_entry);
 127
 128         /* Byte 120 */
 129
 130         p = get_u32(p, &hdr->boot_idx);
 131
 132         /* Byte 124 */
 133
 134         p = get_resource_entry(p, &hdr->integrity);
 135
 136         /* Byte 148 */
 137
 138         /* 60 bytes of unused stuff. */
 139
 140         /* Byte 208 */
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * Writes the header for a WIM file.
 147  *
 148  * @hdr:        A pointer to a struct wim_header structure that describes the header.
 149  * @out_fd:     The file descriptor to the WIM file, opened for writing.
 150  *
 151  * Returns zero on success, nonzero on failure.
 152  */
 153 int
 154 write_header(const struct wim_header *hdr, int out_fd)
 155 {
 156         u8 buf[WIM_HEADER_DISK_SIZE];
 157         u8 *p;
 158         DEBUG("Writing WIM header.");
 159
 160         p = put_bytes(buf, WIM_MAGIC_LEN, wim_magic_chars);
 161         p = put_u32(p, WIM_HEADER_DISK_SIZE);
 162         p = put_u32(p, WIM_VERSION);
 163         p = put_u32(p, hdr->flags);
 164         p = put_u32(p, (hdr->flags & WIM_HDR_FLAG_COMPRESSION) ?
 165                                 WIM_CHUNK_SIZE : 0);
 166         /* Byte 24 */
 167
 168         p = put_bytes(p, WIM_GID_LEN, hdr->guid);
 169         p = put_u16(p, hdr->part_number);
 170
 171         /* Byte 40 */
 172
 173         p = put_u16(p, hdr->total_parts);
 174         p = put_u32(p, hdr->image_count);
 175         p = put_resource_entry(p, &hdr->lookup_table_res_entry);
 176         p = put_resource_entry(p, &hdr->xml_res_entry);
 177         p = put_resource_entry(p, &hdr->boot_metadata_res_entry);
 178         p = put_u32(p, hdr->boot_idx);
 179         p = put_resource_entry(p, &hdr->integrity);
 180         p = put_zeroes(p, WIM_UNUSED_LEN);
 181         wimlib_assert(p - buf == sizeof(buf));
 182
 183         if (full_pwrite(out_fd, buf, sizeof(buf), 0) != sizeof(buf)) {
 184                 ERROR_WITH_ERRNO("Failed to write WIM header");
 185                 return WIMLIB_ERR_WRITE;
 186         }
 187         DEBUG("Done writing WIM header");
 188         return 0;
 189 }
 190
 191 /*
 192  * Initializes the header for a WIM file.
 193  */
 194 int
 195 init_header(struct wim_header *hdr, int ctype)
 196 {
 197         memset(hdr, 0, sizeof(struct wim_header));
 198         switch (ctype) {
 199         case WIMLIB_COMPRESSION_TYPE_NONE:
 200                 hdr->flags = 0;
 201                 break;
 202         case WIMLIB_COMPRESSION_TYPE_LZX:
 203                 hdr->flags = WIM_HDR_FLAG_COMPRESSION |
 204                              WIM_HDR_FLAG_COMPRESS_LZX;
 205                 break;
 206         case WIMLIB_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)", 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
 240 wimlib_print_header(const WIMStruct *w)
 241 {
 242         const struct wim_header *hdr = &w->hdr;
 243
 244         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 245         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 246         tprintf(T("Version                     = 0x%x\n"), WIM_VERSION);
 247
 248         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 249         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 250                 if (hdr_flags[i].flag & hdr->flags)
 251                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 252
 253         tprintf(T("Chunk Size                  = %u\n"), WIM_CHUNK_SIZE);
 254         tfputs (T("GUID                        = "), stdout);
 255         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 256         tputchar(T('\n'));
 257         tprintf(T("Part Number                 = %hu\n"), w->hdr.part_number);
 258         tprintf(T("Total Parts                 = %hu\n"), w->hdr.total_parts);
 259         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 260         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 261                                 (u64)hdr->lookup_table_res_entry.size);
 262         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 263                                 (u8)hdr->lookup_table_res_entry.flags);
 264         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 265                                 hdr->lookup_table_res_entry.offset);
 266         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 267                                 hdr->lookup_table_res_entry.original_size);
 268         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 269                                 (u64)hdr->xml_res_entry.size);
 270         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 271                                 (u8)hdr->xml_res_entry.flags);
 272         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 273                                 hdr->xml_res_entry.offset);
 274         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 275                                 hdr->xml_res_entry.original_size);
 276         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 277                                 (u64)hdr->boot_metadata_res_entry.size);
 278         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 279                                 (u8)hdr->boot_metadata_res_entry.flags);
 280         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 281                                 hdr->boot_metadata_res_entry.offset);
 282         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 283                                 hdr->boot_metadata_res_entry.original_size);
 284         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 285         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 286                                 (u64)hdr->integrity.size);
 287         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 288                                 (u8)hdr->integrity.flags);
 289         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 290                                 hdr->integrity.offset);
 291         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 292                                 hdr->integrity.original_size);
 293 }