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 free software; you can redistribute it and/or modify it under
  11  * the terms of the GNU Lesser General Public License as published by the Free
  12  * Software Foundation; either version 3 of the License, or (at your option) any
  13  * later version.
  14  *
  15  * This file is distributed in the hope that it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this file; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include "config.h"
  26 #endif
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31
  32 #include "wimlib.h"
  33 #include "wimlib/alloca.h"
  34 #include "wimlib/assert.h"
  35 #include "wimlib/endianness.h"
  36 #include "wimlib/error.h"
  37 #include "wimlib/file_io.h"
  38 #include "wimlib/header.h"
  39 #include "wimlib/util.h"
  40 #include "wimlib/wim.h"
  41
  42 /*
  43  * Reads the header from a WIM file.
  44  *
  45  * @wim
  46  *      WIM to read the header from.  @wim->in_fd must be positioned at the
  47  *      beginning of the file.
  48  *
  49  * @hdr
  50  *      Structure to read the header into.
  51  *
  52  * Return values:
  53  *      WIMLIB_ERR_SUCCESS (0)
  54  *      WIMLIB_ERR_IMAGE_COUNT
  55  *      WIMLIB_ERR_INVALID_PART_NUMBER
  56  *      WIMLIB_ERR_NOT_A_WIM_FILE
  57  *      WIMLIB_ERR_READ
  58  *      WIMLIB_ERR_UNEXPECTED_END_OF_FILE
  59  *      WIMLIB_ERR_UNKNOWN_VERSION
  60  */
  61 int
  62 read_wim_header(WIMStruct *wim, struct wim_header *hdr)
  63 {
  64         struct wim_header_disk disk_hdr _aligned_attribute(8);
  65         struct filedes *in_fd = &wim->in_fd;
  66         const tchar *filename = wim->filename;
  67         int ret;
  68         tchar *pipe_str;
  69
  70         wimlib_assert(in_fd->offset == 0);
  71
  72         if (filename == NULL) {
  73                 pipe_str = alloca(40);
  74                 tsprintf(pipe_str, T("[fd %d]"), in_fd->fd);
  75                 filename = pipe_str;
  76         }
  77
  78         BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE);
  79
  80         DEBUG("Reading WIM header from \"%"TS"\"", filename);
  81
  82         ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
  83         if (ret)
  84                 goto read_error;
  85
  86         hdr->magic = le64_to_cpu(disk_hdr.magic);
  87
  88         if (hdr->magic != WIM_MAGIC) {
  89                 if (hdr->magic == PWM_MAGIC) {
  90                         /* Pipable WIM:  Use header at end instead, unless
  91                          * actually reading from a pipe.  */
  92                         if (!in_fd->is_pipe) {
  93                                 ret = WIMLIB_ERR_READ;
  94                                 if (-1 == lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END))
  95                                         goto read_error;
  96                                 ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr));
  97                                 if (ret)
  98                                         goto read_error;
  99                         }
 100                 } else {
 101                         ERROR("\"%"TS"\": Invalid magic characters in header", filename);
 102                         return WIMLIB_ERR_NOT_A_WIM_FILE;
 103                 }
 104         }
 105
 106         if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) {
 107                 ERROR("\"%"TS"\": Header size is invalid (%u bytes)",
 108                       filename, le32_to_cpu(disk_hdr.hdr_size));
 109                 return WIMLIB_ERR_INVALID_HEADER;
 110         }
 111
 112         hdr->wim_version = le32_to_cpu(disk_hdr.wim_version);
 113         if (hdr->wim_version != WIM_VERSION_DEFAULT &&
 114             hdr->wim_version != WIM_VERSION_SOLID)
 115         {
 116                 ERROR("\"%"TS"\": Unknown WIM version: %u",
 117                       filename, hdr->wim_version);
 118                 return WIMLIB_ERR_UNKNOWN_VERSION;
 119         }
 120
 121         hdr->flags = le32_to_cpu(disk_hdr.wim_flags);
 122         hdr->chunk_size = le32_to_cpu(disk_hdr.chunk_size);
 123         memcpy(hdr->guid, disk_hdr.guid, WIM_GUID_LEN);
 124         hdr->part_number = le16_to_cpu(disk_hdr.part_number);
 125         hdr->total_parts = le16_to_cpu(disk_hdr.total_parts);
 126
 127         if (hdr->total_parts == 0 || hdr->part_number == 0 ||
 128             hdr->part_number > hdr->total_parts)
 129         {
 130                 ERROR("\"%"TS"\": Invalid WIM part number: %hu of %hu",
 131                       filename, hdr->part_number, hdr->total_parts);
 132                 return WIMLIB_ERR_INVALID_PART_NUMBER;
 133         }
 134
 135         hdr->image_count = le32_to_cpu(disk_hdr.image_count);
 136
 137         DEBUG("part_number = %u, total_parts = %u, image_count = %u",
 138               hdr->part_number, hdr->total_parts, hdr->image_count);
 139
 140         if (unlikely(hdr->image_count > MAX_IMAGES)) {
 141                 ERROR("\"%"TS"\": Invalid image count (%u)",
 142                       filename, hdr->image_count);
 143                 return WIMLIB_ERR_IMAGE_COUNT;
 144         }
 145
 146         get_wim_reshdr(&disk_hdr.blob_table_reshdr, &hdr->blob_table_reshdr);
 147         get_wim_reshdr(&disk_hdr.xml_data_reshdr, &hdr->xml_data_reshdr);
 148         get_wim_reshdr(&disk_hdr.boot_metadata_reshdr, &hdr->boot_metadata_reshdr);
 149         hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx);
 150         get_wim_reshdr(&disk_hdr.integrity_table_reshdr, &hdr->integrity_table_reshdr);
 151         return 0;
 152
 153 read_error:
 154         ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename);
 155         return ret;
 156 }
 157
 158 /* Writes the header for a WIM file at the specified offset.  If the offset
 159  * specified is the current one, the position is advanced by the size of the
 160  * header.  */
 161 int
 162 write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd,
 163                            off_t offset)
 164 {
 165         struct wim_header_disk disk_hdr _aligned_attribute(8);
 166         int ret;
 167
 168         DEBUG("Writing %sWIM header at offset %"PRIu64,
 169               ((hdr->magic == PWM_MAGIC) ? "pipable " : ""),
 170               offset);
 171
 172         disk_hdr.magic = cpu_to_le64(hdr->magic);
 173         disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk));
 174         disk_hdr.wim_version = cpu_to_le32(hdr->wim_version);
 175         disk_hdr.wim_flags = cpu_to_le32(hdr->flags);
 176         if (hdr->flags & WIM_HDR_FLAG_COMPRESSION)
 177                 disk_hdr.chunk_size = cpu_to_le32(hdr->chunk_size);
 178         else
 179                 disk_hdr.chunk_size = 0;
 180         memcpy(disk_hdr.guid, hdr->guid, WIM_GUID_LEN);
 181
 182         disk_hdr.part_number = cpu_to_le16(hdr->part_number);
 183         disk_hdr.total_parts = cpu_to_le16(hdr->total_parts);
 184         disk_hdr.image_count = cpu_to_le32(hdr->image_count);
 185         put_wim_reshdr(&hdr->blob_table_reshdr, &disk_hdr.blob_table_reshdr);
 186         put_wim_reshdr(&hdr->xml_data_reshdr, &disk_hdr.xml_data_reshdr);
 187         put_wim_reshdr(&hdr->boot_metadata_reshdr, &disk_hdr.boot_metadata_reshdr);
 188         disk_hdr.boot_idx = cpu_to_le32(hdr->boot_idx);
 189         put_wim_reshdr(&hdr->integrity_table_reshdr, &disk_hdr.integrity_table_reshdr);
 190         memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused));
 191
 192         if (offset == out_fd->offset)
 193                 ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr));
 194         else
 195                 ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset);
 196         if (ret)
 197                 ERROR_WITH_ERRNO("Failed to write WIM header");
 198         return ret;
 199 }
 200
 201 /* Writes the header for a WIM file at the output file descriptor's current
 202  * offset.  */
 203 int
 204 write_wim_header(const struct wim_header *hdr, struct filedes *out_fd)
 205 {
 206         return write_wim_header_at_offset(hdr, out_fd, out_fd->offset);
 207 }
 208
 209 /* Update just the wim_flags field. */
 210 int
 211 write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd)
 212 {
 213         le32 flags = cpu_to_le32(hdr_flags);
 214
 215         return full_pwrite(out_fd, &flags, sizeof(flags),
 216                            offsetof(struct wim_header_disk, wim_flags));
 217 }
 218
 219 void
 220 set_wim_hdr_cflags(enum wimlib_compression_type ctype, struct wim_header *hdr)
 221 {
 222         hdr->flags &= ~(WIM_HDR_FLAG_COMPRESSION |
 223                         WIM_HDR_FLAG_COMPRESS_RESERVED |
 224                         WIM_HDR_FLAG_COMPRESS_XPRESS |
 225                         WIM_HDR_FLAG_COMPRESS_LZX |
 226                         WIM_HDR_FLAG_COMPRESS_LZMS |
 227                         WIM_HDR_FLAG_COMPRESS_XPRESS_2);
 228         switch (ctype) {
 229         case WIMLIB_COMPRESSION_TYPE_NONE:
 230                 return;
 231         case WIMLIB_COMPRESSION_TYPE_XPRESS:
 232                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_XPRESS;
 233                 return;
 234         case WIMLIB_COMPRESSION_TYPE_LZX:
 235                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZX;
 236                 return;
 237         case WIMLIB_COMPRESSION_TYPE_LZMS:
 238                 hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZMS;
 239                 return;
 240         }
 241         wimlib_assert(0);
 242 }
 243
 244 /* Initialize the header for a WIM file.  */
 245 void
 246 init_wim_header(struct wim_header *hdr,
 247                 enum wimlib_compression_type ctype, u32 chunk_size)
 248 {
 249         memset(hdr, 0, sizeof(struct wim_header));
 250         hdr->magic = WIM_MAGIC;
 251         if (ctype == WIMLIB_COMPRESSION_TYPE_LZMS)
 252                 hdr->wim_version = WIM_VERSION_SOLID;
 253         else
 254                 hdr->wim_version = WIM_VERSION_DEFAULT;
 255         set_wim_hdr_cflags(ctype, hdr);
 256         hdr->chunk_size = chunk_size;
 257         hdr->total_parts = 1;
 258         hdr->part_number = 1;
 259         randomize_byte_array(hdr->guid, sizeof(hdr->guid));
 260 }
 261
 262 static const struct {
 263         u32 flag;
 264         const char *name;
 265 } hdr_flags[] = {
 266         {WIM_HDR_FLAG_RESERVED,         "RESERVED"},
 267         {WIM_HDR_FLAG_COMPRESSION,      "COMPRESSION"},
 268         {WIM_HDR_FLAG_READONLY,         "READONLY"},
 269         {WIM_HDR_FLAG_SPANNED,          "SPANNED"},
 270         {WIM_HDR_FLAG_RESOURCE_ONLY,    "RESOURCE_ONLY"},
 271         {WIM_HDR_FLAG_METADATA_ONLY,    "METADATA_ONLY"},
 272         {WIM_HDR_FLAG_WRITE_IN_PROGRESS,"WRITE_IN_PROGRESS"},
 273         {WIM_HDR_FLAG_RP_FIX,           "RP_FIX"},
 274         {WIM_HDR_FLAG_COMPRESS_RESERVED,"COMPRESS_RESERVED"},
 275         {WIM_HDR_FLAG_COMPRESS_LZX,     "COMPRESS_LZX"},
 276         {WIM_HDR_FLAG_COMPRESS_XPRESS,  "COMPRESS_XPRESS"},
 277         {WIM_HDR_FLAG_COMPRESS_LZMS,    "COMPRESS_LZMS"},
 278         {WIM_HDR_FLAG_COMPRESS_XPRESS_2,"COMPRESS_XPRESS_2"},
 279 };
 280
 281 /* API function documented in wimlib.h  */
 282 WIMLIBAPI void
 283 wimlib_print_header(const WIMStruct *wim)
 284 {
 285         const struct wim_header *hdr = &wim->hdr;
 286
 287         tprintf(T("Magic Characters            = MSWIM\\000\\000\\000\n"));
 288         tprintf(T("Header Size                 = %u\n"), WIM_HEADER_DISK_SIZE);
 289         tprintf(T("Version                     = 0x%x\n"), hdr->wim_version);
 290
 291         tprintf(T("Flags                       = 0x%x\n"), hdr->flags);
 292         for (size_t i = 0; i < ARRAY_LEN(hdr_flags); i++)
 293                 if (hdr_flags[i].flag & hdr->flags)
 294                         tprintf(T("    WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name);
 295
 296         tprintf(T("Chunk Size                  = %u\n"), hdr->chunk_size);
 297         tfputs (T("GUID                        = "), stdout);
 298         print_byte_field(hdr->guid, WIM_GUID_LEN, stdout);
 299         tputchar(T('\n'));
 300         tprintf(T("Part Number                 = %hu\n"), hdr->part_number);
 301         tprintf(T("Total Parts                 = %hu\n"), hdr->total_parts);
 302         tprintf(T("Image Count                 = %u\n"), hdr->image_count);
 303         tprintf(T("Blob Table Size             = %"PRIu64"\n"),
 304                                 (u64)hdr->blob_table_reshdr.size_in_wim);
 305         tprintf(T("Blob Table Flags            = 0x%hhx\n"),
 306                                 (u8)hdr->blob_table_reshdr.flags);
 307         tprintf(T("Blob Table Offset           = %"PRIu64"\n"),
 308                                 hdr->blob_table_reshdr.offset_in_wim);
 309         tprintf(T("Blob Table Original_size    = %"PRIu64"\n"),
 310                                 hdr->blob_table_reshdr.uncompressed_size);
 311         tprintf(T("XML Data Size               = %"PRIu64"\n"),
 312                                 (u64)hdr->xml_data_reshdr.size_in_wim);
 313         tprintf(T("XML Data Flags              = 0x%hhx\n"),
 314                                 (u8)hdr->xml_data_reshdr.flags);
 315         tprintf(T("XML Data Offset             = %"PRIu64"\n"),
 316                                 hdr->xml_data_reshdr.offset_in_wim);
 317         tprintf(T("XML Data Original Size      = %"PRIu64"\n"),
 318                                 hdr->xml_data_reshdr.uncompressed_size);
 319         tprintf(T("Boot Metadata Size          = %"PRIu64"\n"),
 320                                 (u64)hdr->boot_metadata_reshdr.size_in_wim);
 321         tprintf(T("Boot Metadata Flags         = 0x%hhx\n"),
 322                                 (u8)hdr->boot_metadata_reshdr.flags);
 323         tprintf(T("Boot Metadata Offset        = %"PRIu64"\n"),
 324                                 hdr->boot_metadata_reshdr.offset_in_wim);
 325         tprintf(T("Boot Metadata Original Size = %"PRIu64"\n"),
 326                                 hdr->boot_metadata_reshdr.uncompressed_size);
 327         tprintf(T("Boot Index                  = %u\n"), hdr->boot_idx);
 328         tprintf(T("Integrity Size              = %"PRIu64"\n"),
 329                                 (u64)hdr->integrity_table_reshdr.size_in_wim);
 330         tprintf(T("Integrity Flags             = 0x%hhx\n"),
 331                                 (u8)hdr->integrity_table_reshdr.flags);
 332         tprintf(T("Integrity Offset            = %"PRIu64"\n"),
 333                                 hdr->integrity_table_reshdr.offset_in_wim);
 334         tprintf(T("Integrity Original_size     = %"PRIu64"\n"),
 335                                 hdr->integrity_table_reshdr.uncompressed_size);
 336 }