build/android/rezip/rezip.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // rezip is a tool which is used to modify zip files. It reads in a
   6 // zip file and outputs a new zip file after applying various
   7 // transforms. The tool is used in the Android Chromium build process
   8 // to modify an APK file (which are zip files). The main application
   9 // of this is to modify the APK so that the shared library is no
  10 // longer compressed. Ironically, this saves both transmission and
  11 // device drive space. It saves transmission space because
  12 // uncompressed libraries make much smaller deltas with previous
  13 // versions. It saves device drive space because it is no longer
  14 // necessary to have both a compressed and uncompressed shared library
  15 // on the device. To achieve this the uncompressed library is opened
  16 // directly from within the APK using the "crazy" linker.
  17
  18 #include <assert.h>
  19 #include <string.h>
  20
  21 #include <iostream>
  22 #include <sstream>
  23 #include <string>
  24
  25 #include "third_party/zlib/contrib/minizip/unzip.h"
  26 #include "third_party/zlib/contrib/minizip/zip.h"
  27
  28 const int kMaxFilenameInZip = 256;
  29 const int kMaxExtraFieldInZip = 8192;
  30 const int kBufferSize = 4096;
  31 // Note do not use sysconf(_SC_PAGESIZE) here as that will give you the
  32 // page size of the host, this should be the page size of the target.
  33 const int kPageSizeOnDevice = 4096;
  34
  35 // This is done to avoid having to make a dependency on all of base.
  36 class LogStream {
  37  public:
  38   ~LogStream() {
  39     stream_.flush();
  40     std::cerr << stream_.str() << std::endl;
  41   }
  42   std::ostream& stream() {
  43     return stream_;
  44   }
  45  private:
  46   std::ostringstream stream_;
  47 };
  48
  49 #define LOG(tag) (LogStream().stream() << #tag << ":")
  50
  51 // Copy the data from the currently opened file in the zipfile we are unzipping
  52 // into the currently opened file of the zipfile we are zipping.
  53 static bool CopySubfile(unzFile in_file,
  54                         zipFile out_file,
  55                         const char* in_zip_filename,
  56                         const char* out_zip_filename,
  57                         const char* in_filename,
  58                         const char* out_filename) {
  59   char buf[kBufferSize];
  60
  61   int bytes = 0;
  62   while (true) {
  63     bytes = unzReadCurrentFile(in_file, buf, sizeof(buf));
  64     if (bytes < 0) {
  65       LOG(ERROR) << "failed to read from " << in_filename << " in zipfile "
  66                  << in_zip_filename;
  67       return false;
  68     }
  69
  70     if (bytes == 0) {
  71       break;
  72     }
  73
  74     if (ZIP_OK != zipWriteInFileInZip(out_file, buf, bytes)) {
  75       LOG(ERROR) << "failed to write from " << out_filename << " in zipfile "
  76                  << out_zip_filename;
  77       return false;
  78     }
  79   }
  80
  81   return true;
  82 }
  83
  84 static zip_fileinfo BuildOutInfo(const unz_file_info& in_info) {
  85   zip_fileinfo out_info;
  86   out_info.tmz_date.tm_sec = in_info.tmu_date.tm_sec;
  87   out_info.tmz_date.tm_min = in_info.tmu_date.tm_min;
  88   out_info.tmz_date.tm_hour = in_info.tmu_date.tm_hour;
  89   out_info.tmz_date.tm_mday = in_info.tmu_date.tm_mday;
  90   out_info.tmz_date.tm_mon = in_info.tmu_date.tm_mon;
  91   out_info.tmz_date.tm_year = in_info.tmu_date.tm_year;
  92
  93   out_info.dosDate = in_info.dosDate;
  94   out_info.internal_fa = in_info.internal_fa;
  95   out_info.external_fa = in_info.external_fa;
  96   return out_info;
  97 }
  98
  99 // RAII pattern for closing the unzip file.
 100 class ScopedUnzip {
 101  public:
 102   ScopedUnzip(const char* z_filename)
 103       : z_file_(NULL), z_filename_(z_filename) {}
 104
 105   unzFile OpenOrDie() {
 106     z_file_ = unzOpen(z_filename_);
 107     if (z_file_ == NULL) {
 108       LOG(ERROR) << "failed to open zipfile " << z_filename_;
 109       exit(1);
 110     }
 111     return z_file_;
 112   }
 113
 114   ~ScopedUnzip() {
 115     if (z_file_ != NULL && unzClose(z_file_) != UNZ_OK) {
 116       LOG(ERROR) << "failed to close input zipfile " << z_filename_;
 117       exit(1);
 118     }
 119   }
 120
 121  private:
 122   const char* z_filename_;
 123   unzFile z_file_;
 124 };
 125
 126 // RAII pattern for closing the out zip file.
 127 class ScopedZip {
 128  public:
 129   ScopedZip(const char* z_filename)
 130       : z_file_(NULL), z_filename_(z_filename) {}
 131
 132   zipFile OpenOrDie() {
 133     z_file_ = zipOpen(z_filename_, APPEND_STATUS_CREATE);
 134     if (z_file_ == NULL) {
 135       LOG(ERROR) << "failed to open zipfile " << z_filename_;
 136       exit(1);
 137     }
 138     return z_file_;
 139   }
 140
 141   ~ScopedZip() {
 142     if (z_file_ != NULL && zipClose(z_file_, NULL) != ZIP_OK) {
 143       LOG(ERROR) << "failed to close output zipfile" << z_filename_;
 144       exit(1);
 145     }
 146   }
 147
 148  private:
 149   const char* z_filename_;
 150   zipFile z_file_;
 151 };
 152
 153 typedef std::string (*RenameFun)(const char* in_filename);
 154 typedef int (*AlignFun)(const char* in_filename,
 155                         unzFile in_file,
 156                         char* extra_buffer,
 157                         int size);
 158 typedef bool (*InflatePredicateFun)(const char* filename);
 159
 160 static bool IsPrefixLibraryFilename(const char* filename,
 161                                     const char* base_prefix) {
 162   // We are basically matching "lib/[^/]*/<base_prefix>lib.*[.]so".
 163   // However, we don't have C++11 regex, so we just handroll the test.
 164   // Also we exclude "libchromium_android_linker.so" as a match.
 165   const std::string filename_str = filename;
 166   const std::string prefix = "lib/";
 167   const std::string suffix = ".so";
 168
 169   if (filename_str.length() < suffix.length() + prefix.length()) {
 170     // too short
 171     return false;
 172   }
 173
 174   if (filename_str.compare(0, prefix.size(), prefix) != 0) {
 175     // does not start with "lib/"
 176     return false;
 177   }
 178
 179   if (filename_str.compare(filename_str.length() - suffix.length(),
 180                            suffix.length(),
 181                            suffix) != 0) {
 182     // does not end with ".so"
 183     return false;
 184   }
 185
 186   const size_t last_slash = filename_str.find_last_of('/');
 187   if (last_slash < prefix.length()) {
 188     // Only one slash
 189     return false;
 190   }
 191
 192   const size_t second_slash = filename_str.find_first_of('/', prefix.length());
 193   if (second_slash != last_slash) {
 194     // filename_str contains more than two slashes.
 195     return false;
 196   }
 197
 198   const std::string libprefix = std::string(base_prefix) + "lib";
 199   if (filename_str.compare(last_slash + 1, libprefix.length(), libprefix) !=
 200       0) {
 201     // basename piece does not start with <base_prefix>"lib"
 202     return false;
 203   }
 204
 205   const std::string linker = "libchromium_android_linker.so";
 206   if (last_slash + 1 + linker.length() == filename_str.length() &&
 207       filename_str.compare(last_slash + 1, linker.length(), linker) == 0) {
 208     // Do not match the linker.
 209     return false;
 210   }
 211   return true;
 212 }
 213
 214 static bool IsLibraryFilename(const char* filename) {
 215   return IsPrefixLibraryFilename(filename, "");
 216 }
 217
 218 static bool IsCrazyLibraryFilename(const char* filename) {
 219   return IsPrefixLibraryFilename(filename, "crazy.");
 220 }
 221
 222 static std::string RenameLibraryForCrazyLinker(const char* in_filename) {
 223   if (!IsLibraryFilename(in_filename)) {
 224     // Don't rename
 225     return in_filename;
 226   }
 227
 228   std::string filename_str = in_filename;
 229   size_t last_slash = filename_str.find_last_of('/');
 230   if (last_slash == std::string::npos ||
 231       last_slash == filename_str.length() - 1) {
 232     return in_filename;
 233   }
 234
 235   // We rename the library, so that the Android Package Manager
 236   // no longer extracts the library.
 237   const std::string basename_prefix = "crazy.";
 238   return filename_str.substr(0, last_slash + 1) + basename_prefix +
 239          filename_str.substr(last_slash + 1);
 240 }
 241
 242 // For any file which matches the crazy library pattern "lib/../crazy.lib*.so"
 243 // add sufficient padding to the header that the start of the file will be
 244 // page aligned on the target device.
 245 static int PageAlignCrazyLibrary(const char* in_filename,
 246                                  unzFile in_file,
 247                                  char* extra_buffer,
 248                                  int extra_size) {
 249   if (!IsCrazyLibraryFilename(in_filename)) {
 250     return extra_size;
 251   }
 252   const ZPOS64_T pos = unzGetCurrentFileZStreamPos64(in_file);
 253   const int padding = kPageSizeOnDevice - (pos % kPageSizeOnDevice);
 254   if (padding == kPageSizeOnDevice) {
 255     return extra_size;
 256   }
 257
 258   assert(extra_size < kMaxExtraFieldInZip - padding);
 259   memset(extra_buffer + extra_size, 0, padding);
 260   return extra_size + padding;
 261 }
 262
 263 // As only the read side API provides offsets, we check that we added the
 264 // correct amount of padding by reading the zip file we just generated.
 265 static bool CheckPageAlign(const char* out_zip_filename) {
 266   ScopedUnzip scoped_unzip(out_zip_filename);
 267   unzFile in_file = scoped_unzip.OpenOrDie();
 268
 269   int err = 0;
 270   bool checked = false;
 271   while (true) {
 272     char in_filename[kMaxFilenameInZip + 1];
 273     // Get info and extra field for current file.
 274     unz_file_info in_info;
 275     err = unzGetCurrentFileInfo(in_file,
 276                                 &in_info,
 277                                 in_filename,
 278                                 sizeof(in_filename) - 1,
 279                                 NULL,
 280                                 0,
 281                                 NULL,
 282                                 0);
 283     if (err != UNZ_OK) {
 284       LOG(ERROR) << "failed to get filename" << out_zip_filename;
 285       return false;
 286     }
 287     assert(in_info.size_filename <= kMaxFilenameInZip);
 288     in_filename[in_info.size_filename] = '\0';
 289
 290     if (IsCrazyLibraryFilename(in_filename)) {
 291       err = unzOpenCurrentFile(in_file);
 292       if (err != UNZ_OK) {
 293         LOG(ERROR) << "failed to open subfile" << out_zip_filename << " "
 294                    << in_filename;
 295         return false;
 296       }
 297
 298       const ZPOS64_T pos = unzGetCurrentFileZStreamPos64(in_file);
 299       const int alignment = pos % kPageSizeOnDevice;
 300       checked = (alignment == 0);
 301       if (!checked) {
 302         LOG(ERROR) << "Failed to page align library " << in_filename
 303                    << ", position " << pos << " alignment " << alignment;
 304       }
 305
 306       err = unzCloseCurrentFile(in_file);
 307       if (err != UNZ_OK) {
 308         LOG(ERROR) << "failed to close subfile" << out_zip_filename << " "
 309                    << in_filename;
 310         return false;
 311       }
 312     }
 313
 314     const int next = unzGoToNextFile(in_file);
 315     if (next == UNZ_END_OF_LIST_OF_FILE) {
 316       break;
 317     }
 318     if (next != UNZ_OK) {
 319       LOG(ERROR) << "failed to go to next file" << out_zip_filename;
 320       return false;
 321     }
 322   }
 323   return checked;
 324 }
 325
 326 // Copy files from one archive to another applying alignment, rename and
 327 // inflate transformations if given.
 328 static bool Rezip(const char* in_zip_filename,
 329                   const char* out_zip_filename,
 330                   AlignFun align_fun,
 331                   RenameFun rename_fun,
 332                   InflatePredicateFun inflate_predicate_fun) {
 333   ScopedUnzip scoped_unzip(in_zip_filename);
 334   unzFile in_file = scoped_unzip.OpenOrDie();
 335
 336   ScopedZip scoped_zip(out_zip_filename);
 337   zipFile out_file = scoped_zip.OpenOrDie();
 338   if (unzGoToFirstFile(in_file) != UNZ_OK) {
 339     LOG(ERROR) << "failed to go to first file in " << in_zip_filename;
 340     return false;
 341   }
 342
 343   int err = 0;
 344   while (true) {
 345     char in_filename[kMaxFilenameInZip + 1];
 346     // Get info and extra field for current file.
 347     char extra_buffer[kMaxExtraFieldInZip];
 348     unz_file_info in_info;
 349     err = unzGetCurrentFileInfo(in_file,
 350                                 &in_info,
 351                                 in_filename,
 352                                 sizeof(in_filename) - 1,
 353                                 &extra_buffer,
 354                                 sizeof(extra_buffer),
 355                                 NULL,
 356                                 0);
 357     if (err != UNZ_OK) {
 358       LOG(ERROR) << "failed to get filename " << in_zip_filename;
 359       return false;
 360     }
 361     assert(in_info.size_filename <= kMaxFilenameInZip);
 362     in_filename[in_info.size_filename] = '\0';
 363
 364     std::string out_filename = in_filename;
 365     if (rename_fun != NULL) {
 366       out_filename = rename_fun(in_filename);
 367     }
 368
 369     bool inflate = false;
 370     if (inflate_predicate_fun != NULL) {
 371       inflate = inflate_predicate_fun(in_filename);
 372     }
 373
 374     // Open the current file.
 375     int method = 0;
 376     int level = 0;
 377     int raw = !inflate;
 378     err = unzOpenCurrentFile2(in_file, &method, &level, raw);
 379     if (inflate) {
 380       method = Z_NO_COMPRESSION;
 381       level = 0;
 382     }
 383
 384     if (err != UNZ_OK) {
 385       LOG(ERROR) << "failed to open subfile " << in_zip_filename << " "
 386                  << in_filename;
 387       return false;
 388     }
 389
 390     // Get the extra field from the local header.
 391     char local_extra_buffer[kMaxExtraFieldInZip];
 392     int local_extra_size = unzGetLocalExtrafield(
 393         in_file, &local_extra_buffer, sizeof(local_extra_buffer));
 394
 395     if (align_fun != NULL) {
 396       local_extra_size =
 397           align_fun(in_filename, in_file, local_extra_buffer, local_extra_size);
 398     }
 399
 400     const char* local_extra = local_extra_size > 0 ? local_extra_buffer : NULL;
 401     const char* extra = in_info.size_file_extra > 0 ? extra_buffer : NULL;
 402
 403     // Build the output info structure from the input info structure.
 404     const zip_fileinfo out_info = BuildOutInfo(in_info);
 405
 406     const int ret = zipOpenNewFileInZip4(out_file,
 407                                          out_filename.c_str(),
 408                                          &out_info,
 409                                          local_extra,
 410                                          local_extra_size,
 411                                          extra,
 412                                          in_info.size_file_extra,
 413                                          /* comment */ NULL,
 414                                          method,
 415                                          level,
 416                                          /* raw */ 1,
 417                                          /* windowBits */ 0,
 418                                          /* memLevel */ 0,
 419                                          /* strategy */ 0,
 420                                          /* password */ NULL,
 421                                          /* crcForCrypting */ 0,
 422                                          in_info.version,
 423                                          /* flagBase */ 0);
 424
 425     if (ZIP_OK != ret) {
 426       LOG(ERROR) << "failed to open subfile " << out_zip_filename << " "
 427                  << out_filename;
 428       return false;
 429     }
 430
 431     if (!CopySubfile(in_file,
 432                      out_file,
 433                      in_zip_filename,
 434                      out_zip_filename,
 435                      in_filename,
 436                      out_filename.c_str())) {
 437       return false;
 438     }
 439
 440     if (ZIP_OK != zipCloseFileInZipRaw(
 441                       out_file, in_info.uncompressed_size, in_info.crc)) {
 442       LOG(ERROR) << "failed to close subfile " << out_zip_filename << " "
 443                  << out_filename;
 444       return false;
 445     }
 446
 447     err = unzCloseCurrentFile(in_file);
 448     if (err != UNZ_OK) {
 449       LOG(ERROR) << "failed to close subfile " << in_zip_filename << " "
 450                  << in_filename;
 451       return false;
 452     }
 453     const int next = unzGoToNextFile(in_file);
 454     if (next == UNZ_END_OF_LIST_OF_FILE) {
 455       break;
 456     }
 457     if (next != UNZ_OK) {
 458       LOG(ERROR) << "failed to go to next file" << in_zip_filename;
 459       return false;
 460     }
 461   }
 462
 463   return true;
 464 }
 465
 466 int main(int argc, const char* argv[]) {
 467   if (argc != 4) {
 468     LOG(ERROR) << "Usage: <action> <in_zipfile> <out_zipfile>";
 469     LOG(ERROR) << " <action> is 'inflatealign', 'dropdescriptors' or 'rename'";
 470     LOG(ERROR) << " 'inflatealign'";
 471     LOG(ERROR) << "   inflate and page aligns files of the form "
 472         "lib/*/crazy.lib*.so";
 473     LOG(ERROR) << " 'dropdescriptors':";
 474     LOG(ERROR) << "   remove zip data descriptors from the zip file";
 475     LOG(ERROR) << " 'rename':";
 476     LOG(ERROR) << "   renames files of the form lib/*/lib*.so to "
 477         "lib/*/crazy.lib*.so. Note libchromium_android_linker.so is "
 478         "not renamed as the crazy linker can not load itself.";
 479     exit(1);
 480   }
 481
 482   const char* action = argv[1];
 483   const char* in_zip_filename = argv[2];
 484   const char* out_zip_filename = argv[3];
 485
 486   InflatePredicateFun inflate_predicate_fun = NULL;
 487   AlignFun align_fun = NULL;
 488   RenameFun rename_fun = NULL;
 489   bool check_page_align = false;
 490   if (strcmp("inflatealign", action) == 0) {
 491     inflate_predicate_fun = &IsCrazyLibraryFilename;
 492     align_fun = &PageAlignCrazyLibrary;
 493     check_page_align = true;
 494   } else if (strcmp("rename", action) == 0) {
 495     rename_fun = &RenameLibraryForCrazyLinker;
 496   } else if (strcmp("dropdescriptors", action) == 0) {
 497     // Minizip does not know about data descriptors, so the default
 498     // copying action will drop the descriptors. This should be fine
 499     // as data descriptors are redundant information.
 500     // Note we need to explicitly drop the descriptors before trying to
 501     // do alignment otherwise we will miscalculate the position because
 502     // we don't know about the data descriptors.
 503   } else {
 504     LOG(ERROR) << "Usage: <action> should be 'inflatealign', "
 505                   "'dropdescriptors' or 'rename'";
 506     exit(1);
 507   }
 508
 509   if (!Rezip(in_zip_filename,
 510              out_zip_filename,
 511              align_fun,
 512              rename_fun,
 513              inflate_predicate_fun)) {
 514     exit(1);
 515   }
 516   if (check_page_align && !CheckPageAlign(out_zip_filename)) {
 517     exit(1);
 518   }
 519   return 0;
 520 }