github.com/westcoastroms/westcoastroms-build@v0.0.0-20190928114312-2350e5a73030/build/make/tools/ziptime/ZipEntry.cpp (about)

     1  /*
     2   * Copyright (C) 2006 The Android Open Source Project
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *      http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  //
    18  // Access to entries in a Zip archive.
    19  //
    20  
    21  #include "ZipEntry.h"
    22  
    23  #include <stdio.h>
    24  #include <string.h>
    25  #include <assert.h>
    26  #include <inttypes.h>
    27  
    28  using namespace android;
    29  
    30  #define LOG(...) fprintf(stderr, __VA_ARGS__)
    31  
    32  /* Jan 01 2008 */
    33  #define STATIC_DATE (28 << 9 | 1 << 5 | 1)
    34  #define STATIC_TIME 0
    35  
    36  /*
    37   * Initialize a new ZipEntry structure from a FILE* positioned at a
    38   * CentralDirectoryEntry. Rewrites the headers to remove the dynamic
    39   * timestamps.
    40   *
    41   * On exit, the file pointer will be at the start of the next CDE or
    42   * at the EOCD.
    43   */
    44  status_t ZipEntry::initAndRewriteFromCDE(FILE* fp)
    45  {
    46      status_t result;
    47      long posn;
    48  
    49      /* read the CDE */
    50      result = mCDE.rewrite(fp);
    51      if (result != 0) {
    52          LOG("mCDE.rewrite failed\n");
    53          return result;
    54      }
    55  
    56      /* using the info in the CDE, go load up the LFH */
    57      posn = ftell(fp);
    58      if (fseek(fp, mCDE.mLocalHeaderRelOffset, SEEK_SET) != 0) {
    59          LOG("local header seek failed (%" PRIu32 ")\n",
    60              mCDE.mLocalHeaderRelOffset);
    61          return -1;
    62      }
    63  
    64      result = mLFH.rewrite(fp);
    65      if (result != 0) {
    66          LOG("mLFH.rewrite failed\n");
    67          return result;
    68      }
    69  
    70      if (fseek(fp, posn, SEEK_SET) != 0)
    71          return -1;
    72  
    73      return 0;
    74  }
    75  
    76  /*
    77   * ===========================================================================
    78   *      ZipEntry::LocalFileHeader
    79   * ===========================================================================
    80   */
    81  
    82  /*
    83   * Rewrite a local file header.
    84   *
    85   * On entry, "fp" points to the signature at the start of the header.
    86   */
    87  status_t ZipEntry::LocalFileHeader::rewrite(FILE* fp)
    88  {
    89      uint8_t buf[kLFHLen];
    90  
    91      if (fread(buf, 1, kLFHLen, fp) != kLFHLen)
    92          return -1;
    93  
    94      if (ZipEntry::getLongLE(&buf[0x00]) != kSignature) {
    95          LOG("whoops: didn't find expected signature\n");
    96          return -1;
    97      }
    98  
    99      ZipEntry::putShortLE(&buf[0x0a], STATIC_TIME);
   100      ZipEntry::putShortLE(&buf[0x0c], STATIC_DATE);
   101  
   102      if (fseek(fp, -kLFHLen, SEEK_CUR) != 0)
   103          return -1;
   104  
   105      if (fwrite(buf, 1, kLFHLen, fp) != kLFHLen)
   106          return -1;
   107  
   108      return 0;
   109  }
   110  
   111  /*
   112   * ===========================================================================
   113   *      ZipEntry::CentralDirEntry
   114   * ===========================================================================
   115   */
   116  
   117  /*
   118   * Read and rewrite the central dir entry that appears next in the file.
   119   *
   120   * On entry, "fp" should be positioned on the signature bytes for the
   121   * entry.  On exit, "fp" will point at the signature word for the next
   122   * entry or for the EOCD.
   123   */
   124  status_t ZipEntry::CentralDirEntry::rewrite(FILE* fp)
   125  {
   126      uint8_t buf[kCDELen];
   127      uint16_t fileNameLength, extraFieldLength, fileCommentLength;
   128  
   129      if (fread(buf, 1, kCDELen, fp) != kCDELen)
   130          return -1;
   131  
   132      if (ZipEntry::getLongLE(&buf[0x00]) != kSignature) {
   133          LOG("Whoops: didn't find expected signature\n");
   134          return -1;
   135      }
   136  
   137      ZipEntry::putShortLE(&buf[0x0c], STATIC_TIME);
   138      ZipEntry::putShortLE(&buf[0x0e], STATIC_DATE);
   139  
   140      fileNameLength = ZipEntry::getShortLE(&buf[0x1c]);
   141      extraFieldLength = ZipEntry::getShortLE(&buf[0x1e]);
   142      fileCommentLength = ZipEntry::getShortLE(&buf[0x20]);
   143      mLocalHeaderRelOffset = ZipEntry::getLongLE(&buf[0x2a]);
   144  
   145      if (fseek(fp, -kCDELen, SEEK_CUR) != 0)
   146          return -1;
   147  
   148      if (fwrite(buf, 1, kCDELen, fp) != kCDELen)
   149          return -1;
   150  
   151      if (fseek(fp, fileNameLength + extraFieldLength + fileCommentLength, SEEK_CUR) != 0)
   152          return -1;
   153  
   154      return 0;
   155  }