1/*
2 * Copyright (C) 2015 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#include "entry_name_utils-inl.h"
18#include "zip_archive_common.h"
19#include "ziparchive/zip_writer.h"
20
21#include <utils/Log.h>
22
23#include <sys/param.h>
24
25#include <cassert>
26#include <cstdio>
27#include <memory>
28#include <vector>
29#include <zlib.h>
30#define DEF_MEM_LEVEL 8                // normally in zutil.h?
31
32#if !defined(powerof2)
33#define powerof2(x) ((((x)-1)&(x))==0)
34#endif
35
36/* Zip compression methods we support */
37enum {
38  kCompressStored     = 0,        // no compression
39  kCompressDeflated   = 8,        // standard deflate
40};
41
42// Size of the output buffer used for compression.
43static const size_t kBufSize = 32768u;
44
45// No error, operation completed successfully.
46static const int32_t kNoError = 0;
47
48// The ZipWriter is in a bad state.
49static const int32_t kInvalidState = -1;
50
51// There was an IO error while writing to disk.
52static const int32_t kIoError = -2;
53
54// The zip entry name was invalid.
55static const int32_t kInvalidEntryName = -3;
56
57// An error occurred in zlib.
58static const int32_t kZlibError = -4;
59
60// The start aligned function was called with the aligned flag.
61static const int32_t kInvalidAlign32Flag = -5;
62
63// The alignment parameter is not a power of 2.
64static const int32_t kInvalidAlignment = -6;
65
66static const char* sErrorCodes[] = {
67    "Invalid state",
68    "IO error",
69    "Invalid entry name",
70    "Zlib error",
71};
72
73const char* ZipWriter::ErrorCodeString(int32_t error_code) {
74  if (error_code < 0 && (-error_code) < static_cast<int32_t>(arraysize(sErrorCodes))) {
75    return sErrorCodes[-error_code];
76  }
77  return nullptr;
78}
79
80static void DeleteZStream(z_stream* stream) {
81  deflateEnd(stream);
82  delete stream;
83}
84
85ZipWriter::ZipWriter(FILE* f) : file_(f), current_offset_(0), state_(State::kWritingZip),
86                                z_stream_(nullptr, DeleteZStream), buffer_(kBufSize) {
87}
88
89ZipWriter::ZipWriter(ZipWriter&& writer) : file_(writer.file_),
90                                           current_offset_(writer.current_offset_),
91                                           state_(writer.state_),
92                                           files_(std::move(writer.files_)),
93                                           z_stream_(std::move(writer.z_stream_)),
94                                           buffer_(std::move(writer.buffer_)){
95  writer.file_ = nullptr;
96  writer.state_ = State::kError;
97}
98
99ZipWriter& ZipWriter::operator=(ZipWriter&& writer) {
100  file_ = writer.file_;
101  current_offset_ = writer.current_offset_;
102  state_ = writer.state_;
103  files_ = std::move(writer.files_);
104  z_stream_ = std::move(writer.z_stream_);
105  buffer_ = std::move(writer.buffer_);
106  writer.file_ = nullptr;
107  writer.state_ = State::kError;
108  return *this;
109}
110
111int32_t ZipWriter::HandleError(int32_t error_code) {
112  state_ = State::kError;
113  z_stream_.reset();
114  return error_code;
115}
116
117int32_t ZipWriter::StartEntry(const char* path, size_t flags) {
118  uint32_t alignment = 0;
119  if (flags & kAlign32) {
120    flags &= ~kAlign32;
121    alignment = 4;
122  }
123  return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
124}
125
126int32_t ZipWriter::StartAlignedEntry(const char* path, size_t flags, uint32_t alignment) {
127  return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
128}
129
130int32_t ZipWriter::StartEntryWithTime(const char* path, size_t flags, time_t time) {
131  uint32_t alignment = 0;
132  if (flags & kAlign32) {
133    flags &= ~kAlign32;
134    alignment = 4;
135  }
136  return StartAlignedEntryWithTime(path, flags, time, alignment);
137}
138
139static void ExtractTimeAndDate(time_t when, uint16_t* out_time, uint16_t* out_date) {
140  /* round up to an even number of seconds */
141  when = static_cast<time_t>((static_cast<unsigned long>(when) + 1) & (~1));
142
143  struct tm* ptm;
144#if !defined(_WIN32)
145    struct tm tm_result;
146    ptm = localtime_r(&when, &tm_result);
147#else
148    ptm = localtime(&when);
149#endif
150
151  int year = ptm->tm_year;
152  if (year < 80) {
153    year = 80;
154  }
155
156  *out_date = (year - 80) << 9 | (ptm->tm_mon + 1) << 5 | ptm->tm_mday;
157  *out_time = ptm->tm_hour << 11 | ptm->tm_min << 5 | ptm->tm_sec >> 1;
158}
159
160int32_t ZipWriter::StartAlignedEntryWithTime(const char* path, size_t flags,
161                                             time_t time, uint32_t alignment) {
162  if (state_ != State::kWritingZip) {
163    return kInvalidState;
164  }
165
166  if (flags & kAlign32) {
167    return kInvalidAlign32Flag;
168  }
169
170  if (powerof2(alignment) == 0) {
171    return kInvalidAlignment;
172  }
173
174  FileInfo fileInfo = {};
175  fileInfo.path = std::string(path);
176  fileInfo.local_file_header_offset = current_offset_;
177
178  if (!IsValidEntryName(reinterpret_cast<const uint8_t*>(fileInfo.path.data()),
179                       fileInfo.path.size())) {
180    return kInvalidEntryName;
181  }
182
183  LocalFileHeader header = {};
184  header.lfh_signature = LocalFileHeader::kSignature;
185
186  // Set this flag to denote that a DataDescriptor struct will appear after the data,
187  // containing the crc and size fields.
188  header.gpb_flags |= kGPBDDFlagMask;
189
190  if (flags & ZipWriter::kCompress) {
191    fileInfo.compression_method = kCompressDeflated;
192
193    int32_t result = PrepareDeflate();
194    if (result != kNoError) {
195      return result;
196    }
197  } else {
198    fileInfo.compression_method = kCompressStored;
199  }
200  header.compression_method = fileInfo.compression_method;
201
202  ExtractTimeAndDate(time, &fileInfo.last_mod_time, &fileInfo.last_mod_date);
203  header.last_mod_time = fileInfo.last_mod_time;
204  header.last_mod_date = fileInfo.last_mod_date;
205
206  header.file_name_length = fileInfo.path.size();
207
208  off64_t offset = current_offset_ + sizeof(header) + fileInfo.path.size();
209  std::vector<char> zero_padding;
210  if (alignment != 0 && (offset & (alignment - 1))) {
211    // Pad the extra field so the data will be aligned.
212    uint16_t padding = alignment - (offset % alignment);
213    header.extra_field_length = padding;
214    offset += padding;
215    zero_padding.resize(padding);
216    memset(zero_padding.data(), 0, zero_padding.size());
217  }
218
219  if (fwrite(&header, sizeof(header), 1, file_) != 1) {
220    return HandleError(kIoError);
221  }
222
223  if (fwrite(path, sizeof(*path), fileInfo.path.size(), file_) != fileInfo.path.size()) {
224    return HandleError(kIoError);
225  }
226
227  if (header.extra_field_length != 0 &&
228      fwrite(zero_padding.data(), 1, header.extra_field_length, file_)
229      != header.extra_field_length) {
230    return HandleError(kIoError);
231  }
232
233  files_.emplace_back(std::move(fileInfo));
234
235  current_offset_ = offset;
236  state_ = State::kWritingEntry;
237  return kNoError;
238}
239
240int32_t ZipWriter::PrepareDeflate() {
241  assert(state_ == State::kWritingZip);
242
243  // Initialize the z_stream for compression.
244  z_stream_ = std::unique_ptr<z_stream, void(*)(z_stream*)>(new z_stream(), DeleteZStream);
245
246  int zerr = deflateInit2(z_stream_.get(), Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS,
247                          DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
248  if (zerr != Z_OK) {
249    if (zerr == Z_VERSION_ERROR) {
250      ALOGE("Installed zlib is not compatible with linked version (%s)", ZLIB_VERSION);
251      return HandleError(kZlibError);
252    } else {
253      ALOGE("deflateInit2 failed (zerr=%d)", zerr);
254      return HandleError(kZlibError);
255    }
256  }
257
258  z_stream_->next_out = buffer_.data();
259  z_stream_->avail_out = buffer_.size();
260  return kNoError;
261}
262
263int32_t ZipWriter::WriteBytes(const void* data, size_t len) {
264  if (state_ != State::kWritingEntry) {
265    return HandleError(kInvalidState);
266  }
267
268  FileInfo& currentFile = files_.back();
269  int32_t result = kNoError;
270  if (currentFile.compression_method & kCompressDeflated) {
271    result = CompressBytes(&currentFile, data, len);
272  } else {
273    result = StoreBytes(&currentFile, data, len);
274  }
275
276  if (result != kNoError) {
277    return result;
278  }
279
280  currentFile.crc32 = crc32(currentFile.crc32, reinterpret_cast<const Bytef*>(data), len);
281  currentFile.uncompressed_size += len;
282  return kNoError;
283}
284
285int32_t ZipWriter::StoreBytes(FileInfo* file, const void* data, size_t len) {
286  assert(state_ == State::kWritingEntry);
287
288  if (fwrite(data, 1, len, file_) != len) {
289    return HandleError(kIoError);
290  }
291  file->compressed_size += len;
292  current_offset_ += len;
293  return kNoError;
294}
295
296int32_t ZipWriter::CompressBytes(FileInfo* file, const void* data, size_t len) {
297  assert(state_ == State::kWritingEntry);
298  assert(z_stream_);
299  assert(z_stream_->next_out != nullptr);
300  assert(z_stream_->avail_out != 0);
301
302  // Prepare the input.
303  z_stream_->next_in = reinterpret_cast<const uint8_t*>(data);
304  z_stream_->avail_in = len;
305
306  while (z_stream_->avail_in > 0) {
307    // We have more data to compress.
308    int zerr = deflate(z_stream_.get(), Z_NO_FLUSH);
309    if (zerr != Z_OK) {
310      return HandleError(kZlibError);
311    }
312
313    if (z_stream_->avail_out == 0) {
314      // The output is full, let's write it to disk.
315      size_t write_bytes = z_stream_->next_out - buffer_.data();
316      if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
317        return HandleError(kIoError);
318      }
319      file->compressed_size += write_bytes;
320      current_offset_ += write_bytes;
321
322      // Reset the output buffer for the next input.
323      z_stream_->next_out = buffer_.data();
324      z_stream_->avail_out = buffer_.size();
325    }
326  }
327  return kNoError;
328}
329
330int32_t ZipWriter::FlushCompressedBytes(FileInfo* file) {
331  assert(state_ == State::kWritingEntry);
332  assert(z_stream_);
333  assert(z_stream_->next_out != nullptr);
334  assert(z_stream_->avail_out != 0);
335
336  // Keep deflating while there isn't enough space in the buffer to
337  // to complete the compress.
338  int zerr;
339  while ((zerr = deflate(z_stream_.get(), Z_FINISH)) == Z_OK) {
340    assert(z_stream_->avail_out == 0);
341    size_t write_bytes = z_stream_->next_out - buffer_.data();
342    if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
343      return HandleError(kIoError);
344    }
345    file->compressed_size += write_bytes;
346    current_offset_ += write_bytes;
347
348    z_stream_->next_out = buffer_.data();
349    z_stream_->avail_out = buffer_.size();
350  }
351  if (zerr != Z_STREAM_END) {
352    return HandleError(kZlibError);
353  }
354
355  size_t write_bytes = z_stream_->next_out - buffer_.data();
356  if (write_bytes != 0) {
357    if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
358      return HandleError(kIoError);
359    }
360    file->compressed_size += write_bytes;
361    current_offset_ += write_bytes;
362  }
363  z_stream_.reset();
364  return kNoError;
365}
366
367int32_t ZipWriter::FinishEntry() {
368  if (state_ != State::kWritingEntry) {
369    return kInvalidState;
370  }
371
372  FileInfo& currentFile = files_.back();
373  if (currentFile.compression_method & kCompressDeflated) {
374    int32_t result = FlushCompressedBytes(&currentFile);
375    if (result != kNoError) {
376      return result;
377    }
378  }
379
380  const uint32_t sig = DataDescriptor::kOptSignature;
381  if (fwrite(&sig, sizeof(sig), 1, file_) != 1) {
382    state_ = State::kError;
383    return kIoError;
384  }
385
386  DataDescriptor dd = {};
387  dd.crc32 = currentFile.crc32;
388  dd.compressed_size = currentFile.compressed_size;
389  dd.uncompressed_size = currentFile.uncompressed_size;
390  if (fwrite(&dd, sizeof(dd), 1, file_) != 1) {
391    return HandleError(kIoError);
392  }
393
394  current_offset_ += sizeof(DataDescriptor::kOptSignature) + sizeof(dd);
395  state_ = State::kWritingZip;
396  return kNoError;
397}
398
399int32_t ZipWriter::Finish() {
400  if (state_ != State::kWritingZip) {
401    return kInvalidState;
402  }
403
404  off64_t startOfCdr = current_offset_;
405  for (FileInfo& file : files_) {
406    CentralDirectoryRecord cdr = {};
407    cdr.record_signature = CentralDirectoryRecord::kSignature;
408    cdr.gpb_flags |= kGPBDDFlagMask;
409    cdr.compression_method = file.compression_method;
410    cdr.last_mod_time = file.last_mod_time;
411    cdr.last_mod_date = file.last_mod_date;
412    cdr.crc32 = file.crc32;
413    cdr.compressed_size = file.compressed_size;
414    cdr.uncompressed_size = file.uncompressed_size;
415    cdr.file_name_length = file.path.size();
416    cdr.local_file_header_offset = file.local_file_header_offset;
417    if (fwrite(&cdr, sizeof(cdr), 1, file_) != 1) {
418      return HandleError(kIoError);
419    }
420
421    if (fwrite(file.path.data(), 1, file.path.size(), file_) != file.path.size()) {
422      return HandleError(kIoError);
423    }
424
425    current_offset_ += sizeof(cdr) + file.path.size();
426  }
427
428  EocdRecord er = {};
429  er.eocd_signature = EocdRecord::kSignature;
430  er.disk_num = 0;
431  er.cd_start_disk = 0;
432  er.num_records_on_disk = files_.size();
433  er.num_records = files_.size();
434  er.cd_size = current_offset_ - startOfCdr;
435  er.cd_start_offset = startOfCdr;
436
437  if (fwrite(&er, sizeof(er), 1, file_) != 1) {
438    return HandleError(kIoError);
439  }
440
441  if (fflush(file_) != 0) {
442    return HandleError(kIoError);
443  }
444
445  current_offset_ += sizeof(er);
446  state_ = State::kDone;
447  return kNoError;
448}
449