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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  *      offset at which to read the header.
  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         if (disk_hdr.magic != WIM_MAGIC) {
  93                 if (disk_hdr.magic == PWM_MAGIC) {
  94                         /* Pipable WIM:  Use header at end instead, unless
  95                          * actually reading from a pipe.  */
  96                         if (!in_fd->is_pipe) {
  97                                 lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END);
  98                                 ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
  99                                 if (ret)
 100                                         goto read_error;
 101                         }
 102                 } else {
 103                         ERROR("\"%"TS"\": Invalid magic characters in header", filename);
 104                         return WIMLIB_ERR_NOT_A_WIM_FILE;
 105                 }
 106         }
 107         hdr->magic = disk_hdr.magic;
 108
 109         if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
 110                 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
 111                       filename, le32_to_cpu(disk_hdr.hdr_size));
 112                 return WIMLIB_ERR_INVALID_HEADER;
 113         }
 114
 115         hdr->wim_version = le32_to_cpu(disk_hdr.wim_version);
 116         if (hdr->wim_version != WIM_VERSION_DEFAULT &&
 117             hdr->wim_version != WIM_VERSION_STREAM_CONCAT)
 118         {
 119                 ERROR("\"%"TS"\": Unknown WIM version: %u", hdr->wim_version);
 120                 return WIMLIB_ERR_UNKNOWN_VERSION;
 121         }
 122
 123         hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
 124         hdr->chunk_size = le32_to_cpu(disk_hdr.chunk_size);
 125         memcpy(hdr->guid, disk_hdr.guid, WIM_GID_LEN);
 126         hdr->part_number = le16_to_cpu(disk_hdr.part_number);
 127         hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
 128
 129         if (hdr->total_parts == 0 || hdr->part_number == 0 ||
 130             hdr->part_number > hdr->total_parts)
 131         {
 132                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
 133                       filename, hdr->part_number, hdr->total_parts);
 134                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 135         }
 136
 137         hdr->image_count = le32_to_cpu(disk_hdr.image_count);
 138
 139         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 140               hdr->part_number, hdr->total_parts, hdr->image_count);
 141
 142         if (hdr->image_count >= INT_MAX) {
 143                 ERROR("\"%"TS"\": Invalid image count (%u)",
 144                       filename, hdr->image_count);
 145                 return WIMLIB_ERR_IMAGE_COUNT;
 146         }
 147
 148         get_wim_reshdr(&disk_hdr.lookup_table_reshdr, &hdr->lookup_table_reshdr);
 149         get_wim_reshdr(&disk_hdr.xml_data_reshdr, &hdr->xml_data_reshdr);
 150         get_wim_reshdr(&disk_hdr.boot_metadata_reshdr, &hdr->boot_metadata_reshdr);
 151         hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
 152         get_wim_reshdr(&disk_hdr.integrity_table_reshdr, &hdr->integrity_table_reshdr);
 153         return 0;
 154
 155 read_error:
 156         ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
 157         return ret;
 158 }
 159
 160 /* Writes the header for a WIM file at the specified offset.  If the offset
 161  * specified is the current one, the position is advanced by the size of the
 162  * header.  */
 163 int
 164 write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd,
 165                            off_t offset)
 166 {
 167         struct wim_header_disk disk_hdr _aligned_attribute(8);
 168         int ret;
 169
 170         DEBUG("Writing %sWIM header at offset %"PRIu64,
 171               ((hdr->magic == PWM_MAGIC) ? "pipable " : ""),
 172               offset);
 173
 174         disk_hdr.magic = hdr->magic;
 175         disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
 176         disk_hdr.wim_version = cpu_to_le32(hdr->wim_version);
 177         disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
 178         if (hdr->flags & WIM_HDR_FLAG_COMPRESSION)
 179                 disk_hdr.chunk_size = cpu_to_le32(hdr->chunk_size);
 180         else
 181                 disk_hdr.chunk_size = 0;
 182         memcpy(disk_hdr.guid, hdr->guid, WIM_GID_LEN);
 183
 184         disk_hdr.part_number = cpu_to_le16(hdr->part_number);
 185         disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
 186         disk_hdr.image_count = cpu_to_le32(hdr->image_count);
 187         put_wim_reshdr(&hdr->lookup_table_reshdr, &disk_hdr.lookup_table_reshdr);
 188         put_wim_reshdr(&hdr->xml_data_reshdr, &disk_hdr.xml_data_reshdr);
 189         put_wim_reshdr(&hdr->boot_metadata_reshdr, &disk_hdr.boot_metadata_reshdr);
 190         disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
 191         put_wim_reshdr(&hdr->integrity_table_reshdr, &disk_hdr.integrity_table_reshdr);
 192         memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
 193
 194         if (offset == out_fd->offset)
 195                 ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr));
 196         else
 197                 ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset);
 198         if (ret)
 199                 ERROR_WITH_ERRNO("Failed to write WIM header");
 200         return ret;
 201 }
 202
 203 /* Writes the header for a WIM file at the output file descriptor's current
 204  * offset.  */
 205 int
 206 write_wim_header(const struct wim_header *hdr, struct filedes *out_fd)
 207 {
 208         return write_wim_header_at_offset(hdr, out_fd, out_fd->offset);
 209 }
 210
 211 /* Update just the wim_flags field. */
 212 int
 213 write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd)
 214 {
 215         le32 flags = cpu_to_le32(hdr_flags);
 216
 217         return full_pwrite(out_fd, &flags, sizeof(flags),
 218                            offsetof(struct wim_header_disk, wim_flags));
 219 }
 220
 221 int
 222 set_wim_hdr_cflags(int ctype, struct wim_header *hdr)
 223 {
 224         hdr->flags &= ~(WIM_HDR_FLAG_COMPRESSION |
 225                         WIM_HDR_FLAG_COMPRESS_LZX |
 226                         WIM_HDR_FLAG_COMPRESS_RESERVED |
 227                         WIM_HDR_FLAG_COMPRESS_XPRESS |
 228                         WIM_HDR_FLAG_COMPRESS_LZMS);
 229         switch (ctype) {
 230
 231         case WIMLIB_COMPRESSION_TYPE_NONE:
 232                 return 0;
 233
 234         case WIMLIB_COMPRESSION_TYPE_LZX:
 235                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZX;
 236                 return 0;
 237
 238         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 239                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_XPRESS;
 240                 return 0;
 241
 242         case WIMLIB_COMPRESSION_TYPE_LZMS:
 243                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZMS;
 244                 return 0;
 245
 246         default:
 247                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 248         }
 249 }
 250
 251 /*
 252  * Initializes the header for a WIM file.
 253  */
 254 int
 255 init_wim_header(struct wim_header *hdr, int ctype, u32 chunk_size)
 256 {
 257         memset(hdr, 0, sizeof(struct wim_header));
 258         hdr->magic = WIM_MAGIC;
 259         hdr->wim_version = WIM_VERSION_DEFAULT;
 260         if (set_wim_hdr_cflags(ctype, hdr)) {
 261                 ERROR("Invalid compression type specified (%d)", ctype);
 262                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 263         }
 264         hdr->chunk_size = chunk_size;
 265         hdr->total_parts = 1;
 266         hdr->part_number = 1;
 267         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 268         return 0;
 269 }
 270
 271 struct hdr_flag {
 272         u32 flag;
 273         const char *name;
 274 };
 275 struct hdr_flag hdr_flags[] = {
 276         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 277         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 278         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 279         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 280         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 281         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 282         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 283         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 284         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 285         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 286         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 287 };
 288
 289 /* API function documented in wimlib.h  */
 290 WIMLIBAPI void
 291 wimlib_print_header(const WIMStruct *wim)
 292 {
 293         const struct wim_header *hdr = &wim->hdr;
 294
 295         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 296         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 297         tprintf(T("Version                     = 0x%x\n"), hdr->wim_version);
 298
 299         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 300         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 301                 if (hdr_flags[i].flag & hdr->flags)
 302                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 303
 304         tprintf(T("Chunk Size                  = %u\n"), hdr->chunk_size);
 305         tfputs (T("GUID                        = "), stdout);
 306         print_byte_field(hdr->guid, WIM_GID_LEN, stdout);
 307         tputchar(T('\n'));
 308         tprintf(T("Part Number                 = %hu\n"), hdr->part_number);
 309         tprintf(T("Total Parts                 = %hu\n"), hdr->total_parts);
 310         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 311         tprintf(T("Lookup Table Size           = %"PRIu64"\n"),
 312                                 (u64)hdr->lookup_table_reshdr.size_in_wim);
 313         tprintf(T("Lookup Table Flags          = 0x%hhx\n"),
 314                                 (u8)hdr->lookup_table_reshdr.flags);
 315         tprintf(T("Lookup Table Offset         = %"PRIu64"\n"),
 316                                 hdr->lookup_table_reshdr.offset_in_wim);
 317         tprintf(T("Lookup Table Original_size  = %"PRIu64"\n"),
 318                                 hdr->lookup_table_reshdr.uncompressed_size);
 319         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 320                                 (u64)hdr->xml_data_reshdr.size_in_wim);
 321         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 322                                 (u8)hdr->xml_data_reshdr.flags);
 323         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 324                                 hdr->xml_data_reshdr.offset_in_wim);
 325         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 326                                 hdr->xml_data_reshdr.uncompressed_size);
 327         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 328                                 (u64)hdr->boot_metadata_reshdr.size_in_wim);
 329         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 330                                 (u8)hdr->boot_metadata_reshdr.flags);
 331         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 332                                 hdr->boot_metadata_reshdr.offset_in_wim);
 333         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 334                                 hdr->boot_metadata_reshdr.uncompressed_size);
 335         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 336         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 337                                 (u64)hdr->integrity_table_reshdr.size_in_wim);
 338         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 339                                 (u8)hdr->integrity_table_reshdr.flags);
 340         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 341                                 hdr->integrity_table_reshdr.offset_in_wim);
 342         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 343                                 hdr->integrity_table_reshdr.uncompressed_size);
 344 }