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 "ziparchive/zip_writer.h"
18
19 #include <cstdio>
20 #include <sys/param.h>
21 #include <sys/stat.h>
22 #include <zlib.h>
23 #define DEF_MEM_LEVEL 8 // normally in zutil.h?
24
25 #include <memory>
26 #include <vector>
27
28 #include "android-base/logging.h"
29 #include "utils/Compat.h"
30 #include "utils/Log.h"
31
32 #include "entry_name_utils-inl.h"
33 #include "zip_archive_common.h"
34
35 #if !defined(powerof2)
36 #define powerof2(x) ((((x)-1)&(x))==0)
37 #endif
38
39 /* Zip compression methods we support */
40 enum {
41 kCompressStored = 0, // no compression
42 kCompressDeflated = 8, // standard deflate
43 };
44
45 // Size of the output buffer used for compression.
46 static const size_t kBufSize = 32768u;
47
48 // No error, operation completed successfully.
49 static const int32_t kNoError = 0;
50
51 // The ZipWriter is in a bad state.
52 static const int32_t kInvalidState = -1;
53
54 // There was an IO error while writing to disk.
55 static const int32_t kIoError = -2;
56
57 // The zip entry name was invalid.
58 static const int32_t kInvalidEntryName = -3;
59
60 // An error occurred in zlib.
61 static const int32_t kZlibError = -4;
62
63 // The start aligned function was called with the aligned flag.
64 static const int32_t kInvalidAlign32Flag = -5;
65
66 // The alignment parameter is not a power of 2.
67 static const int32_t kInvalidAlignment = -6;
68
69 static const char* sErrorCodes[] = {
70 "Invalid state",
71 "IO error",
72 "Invalid entry name",
73 "Zlib error",
74 };
75
ErrorCodeString(int32_t error_code)76 const char* ZipWriter::ErrorCodeString(int32_t error_code) {
77 if (error_code < 0 && (-error_code) < static_cast<int32_t>(arraysize(sErrorCodes))) {
78 return sErrorCodes[-error_code];
79 }
80 return nullptr;
81 }
82
DeleteZStream(z_stream * stream)83 static void DeleteZStream(z_stream* stream) {
84 deflateEnd(stream);
85 delete stream;
86 }
87
ZipWriter(FILE * f)88 ZipWriter::ZipWriter(FILE* f) : file_(f), seekable_(false), current_offset_(0),
89 state_(State::kWritingZip), z_stream_(nullptr, DeleteZStream),
90 buffer_(kBufSize) {
91 // Check if the file is seekable (regular file). If fstat fails, that's fine, subsequent calls
92 // will fail as well.
93 struct stat file_stats;
94 if (fstat(fileno(f), &file_stats) == 0) {
95 seekable_ = S_ISREG(file_stats.st_mode);
96 }
97 }
98
ZipWriter(ZipWriter && writer)99 ZipWriter::ZipWriter(ZipWriter&& writer) : file_(writer.file_),
100 seekable_(writer.seekable_),
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 }
109
operator =(ZipWriter && writer)110 ZipWriter& ZipWriter::operator=(ZipWriter&& writer) {
111 file_ = writer.file_;
112 seekable_ = writer.seekable_;
113 current_offset_ = writer.current_offset_;
114 state_ = writer.state_;
115 files_ = std::move(writer.files_);
116 z_stream_ = std::move(writer.z_stream_);
117 buffer_ = std::move(writer.buffer_);
118 writer.file_ = nullptr;
119 writer.state_ = State::kError;
120 return *this;
121 }
122
HandleError(int32_t error_code)123 int32_t ZipWriter::HandleError(int32_t error_code) {
124 state_ = State::kError;
125 z_stream_.reset();
126 return error_code;
127 }
128
StartEntry(const char * path,size_t flags)129 int32_t ZipWriter::StartEntry(const char* path, size_t flags) {
130 uint32_t alignment = 0;
131 if (flags & kAlign32) {
132 flags &= ~kAlign32;
133 alignment = 4;
134 }
135 return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
136 }
137
StartAlignedEntry(const char * path,size_t flags,uint32_t alignment)138 int32_t ZipWriter::StartAlignedEntry(const char* path, size_t flags, uint32_t alignment) {
139 return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
140 }
141
StartEntryWithTime(const char * path,size_t flags,time_t time)142 int32_t ZipWriter::StartEntryWithTime(const char* path, size_t flags, time_t time) {
143 uint32_t alignment = 0;
144 if (flags & kAlign32) {
145 flags &= ~kAlign32;
146 alignment = 4;
147 }
148 return StartAlignedEntryWithTime(path, flags, time, alignment);
149 }
150
ExtractTimeAndDate(time_t when,uint16_t * out_time,uint16_t * out_date)151 static void ExtractTimeAndDate(time_t when, uint16_t* out_time, uint16_t* out_date) {
152 /* round up to an even number of seconds */
153 when = static_cast<time_t>((static_cast<unsigned long>(when) + 1) & (~1));
154
155 struct tm* ptm;
156 #if !defined(_WIN32)
157 struct tm tm_result;
158 ptm = localtime_r(&when, &tm_result);
159 #else
160 ptm = localtime(&when);
161 #endif
162
163 int year = ptm->tm_year;
164 if (year < 80) {
165 year = 80;
166 }
167
168 *out_date = (year - 80) << 9 | (ptm->tm_mon + 1) << 5 | ptm->tm_mday;
169 *out_time = ptm->tm_hour << 11 | ptm->tm_min << 5 | ptm->tm_sec >> 1;
170 }
171
CopyFromFileEntry(const ZipWriter::FileEntry & src,bool use_data_descriptor,LocalFileHeader * dst)172 static void CopyFromFileEntry(const ZipWriter::FileEntry& src, bool use_data_descriptor,
173 LocalFileHeader* dst) {
174 dst->lfh_signature = LocalFileHeader::kSignature;
175 if (use_data_descriptor) {
176 // Set this flag to denote that a DataDescriptor struct will appear after the data,
177 // containing the crc and size fields.
178 dst->gpb_flags |= kGPBDDFlagMask;
179
180 // The size and crc fields must be 0.
181 dst->compressed_size = 0u;
182 dst->uncompressed_size = 0u;
183 dst->crc32 = 0u;
184 } else {
185 dst->compressed_size = src.compressed_size;
186 dst->uncompressed_size = src.uncompressed_size;
187 dst->crc32 = src.crc32;
188 }
189 dst->compression_method = src.compression_method;
190 dst->last_mod_time = src.last_mod_time;
191 dst->last_mod_date = src.last_mod_date;
192 dst->file_name_length = src.path.size();
193 dst->extra_field_length = src.padding_length;
194 }
195
StartAlignedEntryWithTime(const char * path,size_t flags,time_t time,uint32_t alignment)196 int32_t ZipWriter::StartAlignedEntryWithTime(const char* path, size_t flags,
197 time_t time, uint32_t alignment) {
198 if (state_ != State::kWritingZip) {
199 return kInvalidState;
200 }
201
202 if (flags & kAlign32) {
203 return kInvalidAlign32Flag;
204 }
205
206 if (powerof2(alignment) == 0) {
207 return kInvalidAlignment;
208 }
209
210 FileEntry file_entry = {};
211 file_entry.local_file_header_offset = current_offset_;
212 file_entry.path = path;
213
214 if (!IsValidEntryName(reinterpret_cast<const uint8_t*>(file_entry.path.data()),
215 file_entry.path.size())) {
216 return kInvalidEntryName;
217 }
218
219 if (flags & ZipWriter::kCompress) {
220 file_entry.compression_method = kCompressDeflated;
221
222 int32_t result = PrepareDeflate();
223 if (result != kNoError) {
224 return result;
225 }
226 } else {
227 file_entry.compression_method = kCompressStored;
228 }
229
230 ExtractTimeAndDate(time, &file_entry.last_mod_time, &file_entry.last_mod_date);
231
232 off_t offset = current_offset_ + sizeof(LocalFileHeader) + file_entry.path.size();
233 std::vector<char> zero_padding;
234 if (alignment != 0 && (offset & (alignment - 1))) {
235 // Pad the extra field so the data will be aligned.
236 uint16_t padding = alignment - (offset % alignment);
237 file_entry.padding_length = padding;
238 offset += padding;
239 zero_padding.resize(padding, 0);
240 }
241
242 LocalFileHeader header = {};
243 // Always start expecting a data descriptor. When the data has finished being written,
244 // if it is possible to seek back, the GPB flag will reset and the sizes written.
245 CopyFromFileEntry(file_entry, true /*use_data_descriptor*/, &header);
246
247 if (fwrite(&header, sizeof(header), 1, file_) != 1) {
248 return HandleError(kIoError);
249 }
250
251 if (fwrite(path, sizeof(*path), file_entry.path.size(), file_) != file_entry.path.size()) {
252 return HandleError(kIoError);
253 }
254
255 if (file_entry.padding_length != 0 &&
256 fwrite(zero_padding.data(), 1, file_entry.padding_length, file_)
257 != file_entry.padding_length) {
258 return HandleError(kIoError);
259 }
260
261 current_file_entry_ = std::move(file_entry);
262 current_offset_ = offset;
263 state_ = State::kWritingEntry;
264 return kNoError;
265 }
266
DiscardLastEntry()267 int32_t ZipWriter::DiscardLastEntry() {
268 if (state_ != State::kWritingZip || files_.empty()) {
269 return kInvalidState;
270 }
271
272 FileEntry& last_entry = files_.back();
273 current_offset_ = last_entry.local_file_header_offset;
274 if (fseeko(file_, current_offset_, SEEK_SET) != 0) {
275 return HandleError(kIoError);
276 }
277 files_.pop_back();
278 return kNoError;
279 }
280
GetLastEntry(FileEntry * out_entry)281 int32_t ZipWriter::GetLastEntry(FileEntry* out_entry) {
282 CHECK(out_entry != nullptr);
283
284 if (files_.empty()) {
285 return kInvalidState;
286 }
287 *out_entry = files_.back();
288 return kNoError;
289 }
290
PrepareDeflate()291 int32_t ZipWriter::PrepareDeflate() {
292 CHECK(state_ == State::kWritingZip);
293
294 // Initialize the z_stream for compression.
295 z_stream_ = std::unique_ptr<z_stream, void(*)(z_stream*)>(new z_stream(), DeleteZStream);
296
297 #pragma GCC diagnostic push
298 #pragma GCC diagnostic ignored "-Wold-style-cast"
299 int zerr = deflateInit2(z_stream_.get(), Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS,
300 DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
301 #pragma GCC diagnostic pop
302
303 if (zerr != Z_OK) {
304 if (zerr == Z_VERSION_ERROR) {
305 ALOGE("Installed zlib is not compatible with linked version (%s)", ZLIB_VERSION);
306 return HandleError(kZlibError);
307 } else {
308 ALOGE("deflateInit2 failed (zerr=%d)", zerr);
309 return HandleError(kZlibError);
310 }
311 }
312
313 z_stream_->next_out = buffer_.data();
314 z_stream_->avail_out = buffer_.size();
315 return kNoError;
316 }
317
WriteBytes(const void * data,size_t len)318 int32_t ZipWriter::WriteBytes(const void* data, size_t len) {
319 if (state_ != State::kWritingEntry) {
320 return HandleError(kInvalidState);
321 }
322
323 int32_t result = kNoError;
324 if (current_file_entry_.compression_method & kCompressDeflated) {
325 result = CompressBytes(¤t_file_entry_, data, len);
326 } else {
327 result = StoreBytes(¤t_file_entry_, data, len);
328 }
329
330 if (result != kNoError) {
331 return result;
332 }
333
334 current_file_entry_.crc32 = crc32(current_file_entry_.crc32,
335 reinterpret_cast<const Bytef*>(data), len);
336 current_file_entry_.uncompressed_size += len;
337 return kNoError;
338 }
339
StoreBytes(FileEntry * file,const void * data,size_t len)340 int32_t ZipWriter::StoreBytes(FileEntry* file, const void* data, size_t len) {
341 CHECK(state_ == State::kWritingEntry);
342
343 if (fwrite(data, 1, len, file_) != len) {
344 return HandleError(kIoError);
345 }
346 file->compressed_size += len;
347 current_offset_ += len;
348 return kNoError;
349 }
350
CompressBytes(FileEntry * file,const void * data,size_t len)351 int32_t ZipWriter::CompressBytes(FileEntry* file, const void* data, size_t len) {
352 CHECK(state_ == State::kWritingEntry);
353 CHECK(z_stream_);
354 CHECK(z_stream_->next_out != nullptr);
355 CHECK(z_stream_->avail_out != 0);
356
357 // Prepare the input.
358 z_stream_->next_in = reinterpret_cast<const uint8_t*>(data);
359 z_stream_->avail_in = len;
360
361 while (z_stream_->avail_in > 0) {
362 // We have more data to compress.
363 int zerr = deflate(z_stream_.get(), Z_NO_FLUSH);
364 if (zerr != Z_OK) {
365 return HandleError(kZlibError);
366 }
367
368 if (z_stream_->avail_out == 0) {
369 // The output is full, let's write it to disk.
370 size_t write_bytes = z_stream_->next_out - buffer_.data();
371 if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
372 return HandleError(kIoError);
373 }
374 file->compressed_size += write_bytes;
375 current_offset_ += write_bytes;
376
377 // Reset the output buffer for the next input.
378 z_stream_->next_out = buffer_.data();
379 z_stream_->avail_out = buffer_.size();
380 }
381 }
382 return kNoError;
383 }
384
FlushCompressedBytes(FileEntry * file)385 int32_t ZipWriter::FlushCompressedBytes(FileEntry* file) {
386 CHECK(state_ == State::kWritingEntry);
387 CHECK(z_stream_);
388 CHECK(z_stream_->next_out != nullptr);
389 CHECK(z_stream_->avail_out != 0);
390
391 // Keep deflating while there isn't enough space in the buffer to
392 // to complete the compress.
393 int zerr;
394 while ((zerr = deflate(z_stream_.get(), Z_FINISH)) == Z_OK) {
395 CHECK(z_stream_->avail_out == 0);
396 size_t write_bytes = z_stream_->next_out - buffer_.data();
397 if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
398 return HandleError(kIoError);
399 }
400 file->compressed_size += write_bytes;
401 current_offset_ += write_bytes;
402
403 z_stream_->next_out = buffer_.data();
404 z_stream_->avail_out = buffer_.size();
405 }
406 if (zerr != Z_STREAM_END) {
407 return HandleError(kZlibError);
408 }
409
410 size_t write_bytes = z_stream_->next_out - buffer_.data();
411 if (write_bytes != 0) {
412 if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
413 return HandleError(kIoError);
414 }
415 file->compressed_size += write_bytes;
416 current_offset_ += write_bytes;
417 }
418 z_stream_.reset();
419 return kNoError;
420 }
421
FinishEntry()422 int32_t ZipWriter::FinishEntry() {
423 if (state_ != State::kWritingEntry) {
424 return kInvalidState;
425 }
426
427 if (current_file_entry_.compression_method & kCompressDeflated) {
428 int32_t result = FlushCompressedBytes(¤t_file_entry_);
429 if (result != kNoError) {
430 return result;
431 }
432 }
433
434 if ((current_file_entry_.compression_method & kCompressDeflated) || !seekable_) {
435 // Some versions of ZIP don't allow STORED data to have a trailing DataDescriptor.
436 // If this file is not seekable, or if the data is compressed, write a DataDescriptor.
437 const uint32_t sig = DataDescriptor::kOptSignature;
438 if (fwrite(&sig, sizeof(sig), 1, file_) != 1) {
439 return HandleError(kIoError);
440 }
441
442 DataDescriptor dd = {};
443 dd.crc32 = current_file_entry_.crc32;
444 dd.compressed_size = current_file_entry_.compressed_size;
445 dd.uncompressed_size = current_file_entry_.uncompressed_size;
446 if (fwrite(&dd, sizeof(dd), 1, file_) != 1) {
447 return HandleError(kIoError);
448 }
449 current_offset_ += sizeof(DataDescriptor::kOptSignature) + sizeof(dd);
450 } else {
451 // Seek back to the header and rewrite to include the size.
452 if (fseeko(file_, current_file_entry_.local_file_header_offset, SEEK_SET) != 0) {
453 return HandleError(kIoError);
454 }
455
456 LocalFileHeader header = {};
457 CopyFromFileEntry(current_file_entry_, false /*use_data_descriptor*/, &header);
458
459 if (fwrite(&header, sizeof(header), 1, file_) != 1) {
460 return HandleError(kIoError);
461 }
462
463 if (fseeko(file_, current_offset_, SEEK_SET) != 0) {
464 return HandleError(kIoError);
465 }
466 }
467
468 files_.emplace_back(std::move(current_file_entry_));
469 state_ = State::kWritingZip;
470 return kNoError;
471 }
472
Finish()473 int32_t ZipWriter::Finish() {
474 if (state_ != State::kWritingZip) {
475 return kInvalidState;
476 }
477
478 off_t startOfCdr = current_offset_;
479 for (FileEntry& file : files_) {
480 CentralDirectoryRecord cdr = {};
481 cdr.record_signature = CentralDirectoryRecord::kSignature;
482 if ((file.compression_method & kCompressDeflated) || !seekable_) {
483 cdr.gpb_flags |= kGPBDDFlagMask;
484 }
485 cdr.compression_method = file.compression_method;
486 cdr.last_mod_time = file.last_mod_time;
487 cdr.last_mod_date = file.last_mod_date;
488 cdr.crc32 = file.crc32;
489 cdr.compressed_size = file.compressed_size;
490 cdr.uncompressed_size = file.uncompressed_size;
491 cdr.file_name_length = file.path.size();
492 cdr.local_file_header_offset = static_cast<uint32_t>(file.local_file_header_offset);
493 if (fwrite(&cdr, sizeof(cdr), 1, file_) != 1) {
494 return HandleError(kIoError);
495 }
496
497 if (fwrite(file.path.data(), 1, file.path.size(), file_) != file.path.size()) {
498 return HandleError(kIoError);
499 }
500
501 current_offset_ += sizeof(cdr) + file.path.size();
502 }
503
504 EocdRecord er = {};
505 er.eocd_signature = EocdRecord::kSignature;
506 er.disk_num = 0;
507 er.cd_start_disk = 0;
508 er.num_records_on_disk = files_.size();
509 er.num_records = files_.size();
510 er.cd_size = current_offset_ - startOfCdr;
511 er.cd_start_offset = startOfCdr;
512
513 if (fwrite(&er, sizeof(er), 1, file_) != 1) {
514 return HandleError(kIoError);
515 }
516
517 current_offset_ += sizeof(er);
518
519 // Since we can BackUp() and potentially finish writing at an offset less than one we had
520 // already written at, we must truncate the file.
521
522 if (ftruncate(fileno(file_), current_offset_) != 0) {
523 return HandleError(kIoError);
524 }
525
526 if (fflush(file_) != 0) {
527 return HandleError(kIoError);
528 }
529
530 state_ = State::kDone;
531 return kNoError;
532 }
533