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   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 #ifdef HAVE_CONFIG_H
  27 #  include "config.h"
  28 #endif
  29
  30 #include "wimlib.h"
  31 #include "wimlib/assert.h"
  32 #include "wimlib/endianness.h"
  33 #include "wimlib/error.h"
  34 #include "wimlib/file_io.h"
  35 #include "wimlib/header.h"
  36 #include "wimlib/util.h"
  37 #include "wimlib/wim.h"
  38
  39 #include <limits.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42 #ifdef HAVE_ALLOCA_H
  43 #  include <alloca.h>
  44 #else
  45 #  include <stdlib.h>
  46 #endif
  47
  48 /*
  49  * Reads the header from a WIM file.
  50  *
  51  * @wim
  52  *      WIM to read the header from.  @wim->in_fd must be positioned at the
  53  *      beginning of the file.
  54  *
  55  * @hdr
  56  *      Structure to read the header into.
  57  *
  58  * Return values:
  59  *      WIMLIB_ERR_SUCCESS (0)
  60  *      WIMLIB_ERR_IMAGE_COUNT
  61  *      WIMLIB_ERR_INVALID_PART_NUMBER
  62  *      WIMLIB_ERR_NOT_A_WIM_FILE
  63  *      WIMLIB_ERR_READ
  64  *      WIMLIB_ERR_UNEXPECTED_END_OF_FILE
  65  *      WIMLIB_ERR_UNKNOWN_VERSION
  66  */
  67 int
  68 read_wim_header(WIMStruct *wim, struct wim_header *hdr)
  69 {
  70         struct wim_header_disk disk_hdr _aligned_attribute(8);
  71         struct filedes *in_fd = &wim->in_fd;
  72         const tchar *filename = wim->filename;
  73         int ret;
  74         tchar *pipe_str;
  75
  76         wimlib_assert(in_fd->offset == 0);
  77
  78         if (filename == NULL) {
  79                 pipe_str = alloca(40);
  80                 tsprintf(pipe_str, T("[fd %d]"), in_fd->fd);
  81                 filename = pipe_str;
  82         }
  83
  84         BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE);
  85
  86         DEBUG("Reading WIM header from \"%"TS"\"", filename);
  87
  88         ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
  89         if (ret)
  90                 goto read_error;
  91
  92         hdr->magic = le64_to_cpu(disk_hdr.magic);
  93
  94         if (hdr->magic != WIM_MAGIC) {
  95                 if (hdr->magic == PWM_MAGIC) {
  96                         /* Pipable WIM:  Use header at end instead, unless
  97                          * actually reading from a pipe.  */
  98                         if (!in_fd->is_pipe) {
  99                                 ret = WIMLIB_ERR_READ;
 100                                 if (-1 == lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END))
 101                                         goto read_error;
 102                                 ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
 103                                 if (ret)
 104                                         goto read_error;
 105                         }
 106                 } else {
 107                         ERROR("\"%"TS"\": Invalid magic characters in header", filename);
 108                         return WIMLIB_ERR_NOT_A_WIM_FILE;
 109                 }
 110         }
 111
 112         if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
 113                 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
 114                       filename, le32_to_cpu(disk_hdr.hdr_size));
 115                 return WIMLIB_ERR_INVALID_HEADER;
 116         }
 117
 118         hdr->wim_version = le32_to_cpu(disk_hdr.wim_version);
 119         if (hdr->wim_version != WIM_VERSION_DEFAULT &&
 120             hdr->wim_version != WIM_VERSION_PACKED_STREAMS)
 121         {
 122                 ERROR("\"%"TS"\": Unknown WIM version: %u",
 123                       filename, hdr->wim_version);
 124                 return WIMLIB_ERR_UNKNOWN_VERSION;
 125         }
 126
 127         hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
 128         hdr->chunk_size = le32_to_cpu(disk_hdr.chunk_size);
 129         memcpy(hdr->guid, disk_hdr.guid, WIM_GUID_LEN);
 130         hdr->part_number = le16_to_cpu(disk_hdr.part_number);
 131         hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
 132
 133         if (hdr->total_parts == 0 || hdr->part_number == 0 ||
 134             hdr->part_number > hdr->total_parts)
 135         {
 136                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
 137                       filename, hdr->part_number, hdr->total_parts);
 138                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 139         }
 140
 141         hdr->image_count = le32_to_cpu(disk_hdr.image_count);
 142
 143         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 144               hdr->part_number, hdr->total_parts, hdr->image_count);
 145
 146         if (unlikely(hdr->image_count > MAX_IMAGES)) {
 147                 ERROR("\"%"TS"\": Invalid image count (%u)",
 148                       filename, hdr->image_count);
 149                 return WIMLIB_ERR_IMAGE_COUNT;
 150         }
 151
 152         get_wim_reshdr(&disk_hdr.lookup_table_reshdr, &hdr->lookup_table_reshdr);
 153         get_wim_reshdr(&disk_hdr.xml_data_reshdr, &hdr->xml_data_reshdr);
 154         get_wim_reshdr(&disk_hdr.boot_metadata_reshdr, &hdr->boot_metadata_reshdr);
 155         hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
 156         get_wim_reshdr(&disk_hdr.integrity_table_reshdr, &hdr->integrity_table_reshdr);
 157         return 0;
 158
 159 read_error:
 160         ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
 161         return ret;
 162 }
 163
 164 /* Writes the header for a WIM file at the specified offset.  If the offset
 165  * specified is the current one, the position is advanced by the size of the
 166  * header.  */
 167 int
 168 write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd,
 169                            off_t offset)
 170 {
 171         struct wim_header_disk disk_hdr _aligned_attribute(8);
 172         int ret;
 173
 174         DEBUG("Writing %sWIM header at offset %"PRIu64,
 175               ((hdr->magic == PWM_MAGIC) ? "pipable " : ""),
 176               offset);
 177
 178         disk_hdr.magic = cpu_to_le64(hdr->magic);
 179         disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
 180         disk_hdr.wim_version = cpu_to_le32(hdr->wim_version);
 181         disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
 182         if (hdr->flags & WIM_HDR_FLAG_COMPRESSION)
 183                 disk_hdr.chunk_size = cpu_to_le32(hdr->chunk_size);
 184         else
 185                 disk_hdr.chunk_size = 0;
 186         memcpy(disk_hdr.guid, hdr->guid, WIM_GUID_LEN);
 187
 188         disk_hdr.part_number = cpu_to_le16(hdr->part_number);
 189         disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
 190         disk_hdr.image_count = cpu_to_le32(hdr->image_count);
 191         put_wim_reshdr(&hdr->lookup_table_reshdr, &disk_hdr.lookup_table_reshdr);
 192         put_wim_reshdr(&hdr->xml_data_reshdr, &disk_hdr.xml_data_reshdr);
 193         put_wim_reshdr(&hdr->boot_metadata_reshdr, &disk_hdr.boot_metadata_reshdr);
 194         disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
 195         put_wim_reshdr(&hdr->integrity_table_reshdr, &disk_hdr.integrity_table_reshdr);
 196         memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
 197
 198         if (offset == out_fd->offset)
 199                 ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr));
 200         else
 201                 ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset);
 202         if (ret)
 203                 ERROR_WITH_ERRNO("Failed to write WIM header");
 204         return ret;
 205 }
 206
 207 /* Writes the header for a WIM file at the output file descriptor's current
 208  * offset.  */
 209 int
 210 write_wim_header(const struct wim_header *hdr, struct filedes *out_fd)
 211 {
 212         return write_wim_header_at_offset(hdr, out_fd, out_fd->offset);
 213 }
 214
 215 /* Update just the wim_flags field. */
 216 int
 217 write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd)
 218 {
 219         le32 flags = cpu_to_le32(hdr_flags);
 220
 221         return full_pwrite(out_fd, &flags, sizeof(flags),
 222                            offsetof(struct wim_header_disk, wim_flags));
 223 }
 224
 225 int
 226 set_wim_hdr_cflags(int ctype, struct wim_header *hdr)
 227 {
 228         hdr->flags &= ~(WIM_HDR_FLAG_COMPRESSION |
 229                         WIM_HDR_FLAG_COMPRESS_LZX |
 230                         WIM_HDR_FLAG_COMPRESS_RESERVED |
 231                         WIM_HDR_FLAG_COMPRESS_XPRESS |
 232                         WIM_HDR_FLAG_COMPRESS_LZMS |
 233                         WIM_HDR_FLAG_COMPRESS_XPRESS_2);
 234         switch (ctype) {
 235
 236         case WIMLIB_COMPRESSION_TYPE_NONE:
 237                 return 0;
 238
 239         case WIMLIB_COMPRESSION_TYPE_LZX:
 240                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZX;
 241                 return 0;
 242
 243         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 244                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_XPRESS;
 245                 return 0;
 246
 247         case WIMLIB_COMPRESSION_TYPE_LZMS:
 248                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZMS;
 249                 return 0;
 250
 251         default:
 252                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 253         }
 254 }
 255
 256 /*
 257  * Initializes the header for a WIM file.
 258  */
 259 int
 260 init_wim_header(struct wim_header *hdr, int ctype, u32 chunk_size)
 261 {
 262         memset(hdr, 0, sizeof(struct wim_header));
 263         hdr->magic = WIM_MAGIC;
 264
 265         if (ctype == WIMLIB_COMPRESSION_TYPE_LZMS)
 266                 hdr->wim_version = WIM_VERSION_PACKED_STREAMS;
 267         else
 268                 hdr->wim_version = WIM_VERSION_DEFAULT;
 269         if (set_wim_hdr_cflags(ctype, hdr)) {
 270                 ERROR("Invalid compression type specified (%d)", ctype);
 271                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 272         }
 273         hdr->chunk_size = chunk_size;
 274         hdr->total_parts = 1;
 275         hdr->part_number = 1;
 276         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 277         return 0;
 278 }
 279
 280 struct hdr_flag {
 281         u32 flag;
 282         const char *name;
 283 };
 284 struct hdr_flag hdr_flags[] = {
 285         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 286         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 287         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 288         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 289         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 290         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 291         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 292         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 293         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 294         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 295         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 296         {WIM_HDR_FLAG_COMPRESS_LZMS,    "COMPRESS_LZMS"},
 297         {WIM_HDR_FLAG_COMPRESS_XPRESS_2,"COMPRESS_XPRESS_2"},
 298 };
 299
 300 /* API function documented in wimlib.h  */
 301 WIMLIBAPI void
 302 wimlib_print_header(const WIMStruct *wim)
 303 {
 304         const struct wim_header *hdr = &wim->hdr;
 305
 306         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 307         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 308         tprintf(T("Version                     = 0x%x\n"), hdr->wim_version);
 309
 310         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 311         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 312                 if (hdr_flags[i].flag & hdr->flags)
 313                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 314
 315         tprintf(T("Chunk Size                  = %u\n"), hdr->chunk_size);
 316         tfputs (T("GUID                        = "), stdout);
 317         print_byte_field(hdr->guid, WIM_GUID_LEN, stdout);
 318         tputchar(T('\n'));
 319         tprintf(T("Part Number                 = %hu\n"), hdr->part_number);
 320         tprintf(T("Total Parts                 = %hu\n"), hdr->total_parts);
 321         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 322         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 323                                 (u64)hdr->lookup_table_reshdr.size_in_wim);
 324         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 325                                 (u8)hdr->lookup_table_reshdr.flags);
 326         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 327                                 hdr->lookup_table_reshdr.offset_in_wim);
 328         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 329                                 hdr->lookup_table_reshdr.uncompressed_size);
 330         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 331                                 (u64)hdr->xml_data_reshdr.size_in_wim);
 332         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 333                                 (u8)hdr->xml_data_reshdr.flags);
 334         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 335                                 hdr->xml_data_reshdr.offset_in_wim);
 336         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 337                                 hdr->xml_data_reshdr.uncompressed_size);
 338         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 339                                 (u64)hdr->boot_metadata_reshdr.size_in_wim);
 340         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 341                                 (u8)hdr->boot_metadata_reshdr.flags);
 342         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 343                                 hdr->boot_metadata_reshdr.offset_in_wim);
 344         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 345                                 hdr->boot_metadata_reshdr.uncompressed_size);
 346         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 347         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 348                                 (u64)hdr->integrity_table_reshdr.size_in_wim);
 349         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 350                                 (u8)hdr->integrity_table_reshdr.flags);
 351         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 352                                 hdr->integrity_table_reshdr.offset_in_wim);
 353         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 354                                 hdr->integrity_table_reshdr.uncompressed_size);
 355 }