net/filter/gzip_filter_unittest.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 #include <fstream>
   6 #include <ostream>
   7
   8 #include "base/files/file_util.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/path_service.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/filter/gzip_filter.h"
  13 #include "net/filter/mock_filter_context.h"
  14 #include "testing/gtest/include/gtest/gtest.h"
  15 #include "testing/platform_test.h"
  16 #include "third_party/zlib/zlib.h"
  17
  18 namespace {
  19
  20 const int kDefaultBufferSize = 4096;
  21 const int kSmallBufferSize = 128;
  22
  23 // The GZIP header (see RFC 1952):
  24 //   +---+---+---+---+---+---+---+---+---+---+
  25 //   |ID1|ID2|CM |FLG|     MTIME     |XFL|OS |
  26 //   +---+---+---+---+---+---+---+---+---+---+
  27 //     ID1     \037
  28 //     ID2     \213
  29 //     CM      \010 (compression method == DEFLATE)
  30 //     FLG     \000 (special flags that we do not support)
  31 //     MTIME   Unix format modification time (0 means not available)
  32 //     XFL     2-4? DEFLATE flags
  33 //     OS      ???? Operating system indicator (255 means unknown)
  34 //
  35 // Header value we generate:
  36 const char kGZipHeader[] = { '\037', '\213', '\010', '\000', '\000',
  37                              '\000', '\000', '\000', '\002', '\377' };
  38
  39 enum EncodeMode {
  40   ENCODE_GZIP,      // Wrap the deflate with a GZip header.
  41   ENCODE_DEFLATE    // Raw deflate.
  42 };
  43
  44 }  // namespace
  45
  46 namespace net {
  47
  48 // These tests use the path service, which uses autoreleased objects on the
  49 // Mac, so this needs to be a PlatformTest.
  50 class GZipUnitTest : public PlatformTest {
  51  protected:
  52   void SetUp() override {
  53     PlatformTest::SetUp();
  54
  55     deflate_encode_buffer_ = NULL;
  56     gzip_encode_buffer_ = NULL;
  57
  58     // Get the path of source data file.
  59     base::FilePath file_path;
  60     PathService::Get(base::DIR_SOURCE_ROOT, &file_path);
  61     file_path = file_path.AppendASCII("net");
  62     file_path = file_path.AppendASCII("data");
  63     file_path = file_path.AppendASCII("filter_unittests");
  64     file_path = file_path.AppendASCII("google.txt");
  65
  66     // Read data from the file into buffer.
  67     ASSERT_TRUE(base::ReadFileToString(file_path, &source_buffer_));
  68
  69     // Encode the data with deflate
  70     deflate_encode_buffer_ = new char[kDefaultBufferSize];
  71     ASSERT_TRUE(deflate_encode_buffer_ != NULL);
  72
  73     deflate_encode_len_ = kDefaultBufferSize;
  74     int code = CompressAll(ENCODE_DEFLATE , source_buffer(), source_len(),
  75                            deflate_encode_buffer_, &deflate_encode_len_);
  76     ASSERT_TRUE(code == Z_STREAM_END);
  77     ASSERT_GT(deflate_encode_len_, 0);
  78     ASSERT_TRUE(deflate_encode_len_ <= kDefaultBufferSize);
  79
  80     // Encode the data with gzip
  81     gzip_encode_buffer_ = new char[kDefaultBufferSize];
  82     ASSERT_TRUE(gzip_encode_buffer_ != NULL);
  83
  84     gzip_encode_len_ = kDefaultBufferSize;
  85     code = CompressAll(ENCODE_GZIP, source_buffer(), source_len(),
  86                            gzip_encode_buffer_, &gzip_encode_len_);
  87     ASSERT_TRUE(code == Z_STREAM_END);
  88     ASSERT_GT(gzip_encode_len_, 0);
  89     ASSERT_TRUE(gzip_encode_len_ <= kDefaultBufferSize);
  90   }
  91
  92   void TearDown() override {
  93     delete[] deflate_encode_buffer_;
  94     deflate_encode_buffer_ = NULL;
  95
  96     delete[] gzip_encode_buffer_;
  97     gzip_encode_buffer_ = NULL;
  98
  99     PlatformTest::TearDown();
 100   }
 101
 102   // Compress the data in source with deflate encoding and write output to the
 103   // buffer provided by dest. The function returns Z_OK if success, and returns
 104   // other zlib error code if fail.
 105   // The parameter mode specifies the encoding mechanism.
 106   // The dest buffer should be large enough to hold all the output data.
 107   int CompressAll(EncodeMode mode, const char* source, int source_size,
 108                   char* dest, int* dest_len) {
 109     z_stream zlib_stream;
 110     memset(&zlib_stream, 0, sizeof(zlib_stream));
 111     int code;
 112
 113     // Initialize zlib
 114     if (mode == ENCODE_GZIP) {
 115       code = deflateInit2(&zlib_stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
 116                           -MAX_WBITS,
 117                           8,  // DEF_MEM_LEVEL
 118                           Z_DEFAULT_STRATEGY);
 119     } else {
 120       code = deflateInit(&zlib_stream, Z_DEFAULT_COMPRESSION);
 121     }
 122
 123     if (code != Z_OK)
 124       return code;
 125
 126     // Fill in zlib control block
 127     zlib_stream.next_in = bit_cast<Bytef*>(source);
 128     zlib_stream.avail_in = source_size;
 129     zlib_stream.next_out = bit_cast<Bytef*>(dest);
 130     zlib_stream.avail_out = *dest_len;
 131
 132     // Write header if needed
 133     if (mode == ENCODE_GZIP) {
 134       if (zlib_stream.avail_out < sizeof(kGZipHeader))
 135         return Z_BUF_ERROR;
 136       memcpy(zlib_stream.next_out, kGZipHeader, sizeof(kGZipHeader));
 137       zlib_stream.next_out += sizeof(kGZipHeader);
 138       zlib_stream.avail_out -= sizeof(kGZipHeader);
 139     }
 140
 141     // Do deflate
 142     code = deflate(&zlib_stream, Z_FINISH);
 143     *dest_len = *dest_len - zlib_stream.avail_out;
 144
 145     deflateEnd(&zlib_stream);
 146     return code;
 147   }
 148
 149   // Use filter to decode compressed data, and compare the decoding result with
 150   // the orginal Data.
 151   // Parameters: Source and source_len are original data and its size.
 152   // Encoded_source and encoded_source_len are compressed data and its size.
 153   // Output_buffer_size specifies the size of buffer to read out data from
 154   // filter.
 155   void DecodeAndCompareWithFilter(Filter* filter,
 156                                   const char* source,
 157                                   int source_len,
 158                                   const char* encoded_source,
 159                                   int encoded_source_len,
 160                                   int output_buffer_size) {
 161     // Make sure we have enough space to hold the decoding output.
 162     ASSERT_TRUE(source_len <= kDefaultBufferSize);
 163     ASSERT_TRUE(output_buffer_size <= kDefaultBufferSize);
 164
 165     char decode_buffer[kDefaultBufferSize];
 166     char* decode_next = decode_buffer;
 167     int decode_avail_size = kDefaultBufferSize;
 168
 169     const char* encode_next = encoded_source;
 170     int encode_avail_size = encoded_source_len;
 171
 172     int code = Filter::FILTER_OK;
 173     while (code != Filter::FILTER_DONE) {
 174       int encode_data_len;
 175       encode_data_len = std::min(encode_avail_size,
 176                                  filter->stream_buffer_size());
 177       memcpy(filter->stream_buffer()->data(), encode_next, encode_data_len);
 178       filter->FlushStreamBuffer(encode_data_len);
 179       encode_next += encode_data_len;
 180       encode_avail_size -= encode_data_len;
 181
 182       while (1) {
 183         int decode_data_len = std::min(decode_avail_size, output_buffer_size);
 184
 185         code = filter->ReadData(decode_next, &decode_data_len);
 186         decode_next += decode_data_len;
 187         decode_avail_size -= decode_data_len;
 188
 189         ASSERT_TRUE(code != Filter::FILTER_ERROR);
 190
 191         if (code == Filter::FILTER_NEED_MORE_DATA ||
 192             code == Filter::FILTER_DONE) {
 193           break;
 194         }
 195       }
 196     }
 197
 198     // Compare the decoding result with source data
 199     int decode_total_data_len = kDefaultBufferSize - decode_avail_size;
 200     EXPECT_TRUE(decode_total_data_len == source_len);
 201     EXPECT_EQ(memcmp(source, decode_buffer, source_len), 0);
 202   }
 203
 204   // Unsafe function to use filter to decode compressed data.
 205   // Parameters: Source and source_len are compressed data and its size.
 206   // Dest is the buffer for decoding results. Upon entry, *dest_len is the size
 207   // of the dest buffer. Upon exit, *dest_len is the number of chars written
 208   // into the buffer.
 209   int DecodeAllWithFilter(Filter* filter, const char* source, int source_len,
 210                           char* dest, int* dest_len) {
 211     memcpy(filter->stream_buffer()->data(), source, source_len);
 212     filter->FlushStreamBuffer(source_len);
 213     return filter->ReadData(dest, dest_len);
 214   }
 215
 216   void InitFilter(Filter::FilterType type) {
 217     std::vector<Filter::FilterType> filter_types;
 218     filter_types.push_back(type);
 219     filter_.reset(Filter::Factory(filter_types, filter_context_));
 220     ASSERT_TRUE(filter_.get());
 221     ASSERT_GE(filter_->stream_buffer_size(), kDefaultBufferSize);
 222   }
 223
 224   void InitFilterWithBufferSize(Filter::FilterType type, int buffer_size) {
 225     std::vector<Filter::FilterType> filter_types;
 226     filter_types.push_back(type);
 227     filter_.reset(Filter::FactoryForTests(filter_types, filter_context_,
 228                                           buffer_size));
 229     ASSERT_TRUE(filter_.get());
 230   }
 231
 232   const char* source_buffer() const { return source_buffer_.data(); }
 233   int source_len() const { return static_cast<int>(source_buffer_.size()); }
 234
 235   scoped_ptr<Filter> filter_;
 236
 237   std::string source_buffer_;
 238
 239   char* deflate_encode_buffer_;
 240   int deflate_encode_len_;
 241
 242   char* gzip_encode_buffer_;
 243   int gzip_encode_len_;
 244
 245  private:
 246   MockFilterContext filter_context_;
 247 };
 248
 249 // Basic scenario: decoding deflate data with big enough buffer.
 250 TEST_F(GZipUnitTest, DecodeDeflate) {
 251   // Decode the compressed data with filter
 252   InitFilter(Filter::FILTER_TYPE_DEFLATE);
 253   memcpy(filter_->stream_buffer()->data(), deflate_encode_buffer_,
 254          deflate_encode_len_);
 255   filter_->FlushStreamBuffer(deflate_encode_len_);
 256
 257   char deflate_decode_buffer[kDefaultBufferSize];
 258   int deflate_decode_size = kDefaultBufferSize;
 259   filter_->ReadData(deflate_decode_buffer, &deflate_decode_size);
 260
 261   // Compare the decoding result with source data
 262   EXPECT_TRUE(deflate_decode_size == source_len());
 263   EXPECT_EQ(memcmp(source_buffer(), deflate_decode_buffer, source_len()), 0);
 264 }
 265
 266 // Basic scenario: decoding gzip data with big enough buffer.
 267 TEST_F(GZipUnitTest, DecodeGZip) {
 268   // Decode the compressed data with filter
 269   InitFilter(Filter::FILTER_TYPE_GZIP);
 270   memcpy(filter_->stream_buffer()->data(), gzip_encode_buffer_,
 271          gzip_encode_len_);
 272   filter_->FlushStreamBuffer(gzip_encode_len_);
 273
 274   char gzip_decode_buffer[kDefaultBufferSize];
 275   int gzip_decode_size = kDefaultBufferSize;
 276   filter_->ReadData(gzip_decode_buffer, &gzip_decode_size);
 277
 278   // Compare the decoding result with source data
 279   EXPECT_TRUE(gzip_decode_size == source_len());
 280   EXPECT_EQ(memcmp(source_buffer(), gzip_decode_buffer, source_len()), 0);
 281 }
 282
 283 // Tests we can call filter repeatedly to get all the data decoded.
 284 // To do that, we create a filter with a small buffer that can not hold all
 285 // the input data.
 286 TEST_F(GZipUnitTest, DecodeWithSmallBuffer) {
 287   InitFilterWithBufferSize(Filter::FILTER_TYPE_DEFLATE, kSmallBufferSize);
 288   EXPECT_EQ(kSmallBufferSize, filter_->stream_buffer_size());
 289   DecodeAndCompareWithFilter(filter_.get(), source_buffer(), source_len(),
 290                              deflate_encode_buffer_, deflate_encode_len_,
 291                              kDefaultBufferSize);
 292 }
 293
 294 // Tests we can still decode with just 1 byte buffer in the filter.
 295 // The purpose of this tests are two: (1) Verify filter can parse partial GZip
 296 // header correctly. (2) Sometimes the filter will consume input without
 297 // generating output. Verify filter can handle it correctly.
 298 TEST_F(GZipUnitTest, DecodeWithOneByteBuffer) {
 299   InitFilterWithBufferSize(Filter::FILTER_TYPE_GZIP, 1);
 300   EXPECT_EQ(1, filter_->stream_buffer_size());
 301   DecodeAndCompareWithFilter(filter_.get(), source_buffer(), source_len(),
 302                              gzip_encode_buffer_, gzip_encode_len_,
 303                              kDefaultBufferSize);
 304 }
 305
 306 // Tests we can decode when caller has small buffer to read out from filter.
 307 TEST_F(GZipUnitTest, DecodeWithSmallOutputBuffer) {
 308   InitFilter(Filter::FILTER_TYPE_DEFLATE);
 309   DecodeAndCompareWithFilter(filter_.get(), source_buffer(), source_len(),
 310                              deflate_encode_buffer_, deflate_encode_len_,
 311                              kSmallBufferSize);
 312 }
 313
 314 // Tests we can still decode with just 1 byte buffer in the filter and just 1
 315 // byte buffer in the caller.
 316 TEST_F(GZipUnitTest, DecodeWithOneByteInputAndOutputBuffer) {
 317   InitFilterWithBufferSize(Filter::FILTER_TYPE_GZIP, 1);
 318   EXPECT_EQ(1, filter_->stream_buffer_size());
 319   DecodeAndCompareWithFilter(filter_.get(), source_buffer(), source_len(),
 320                              gzip_encode_buffer_, gzip_encode_len_, 1);
 321 }
 322
 323 // Decoding deflate stream with corrupted data.
 324 TEST_F(GZipUnitTest, DecodeCorruptedData) {
 325   char corrupt_data[kDefaultBufferSize];
 326   int corrupt_data_len = deflate_encode_len_;
 327   memcpy(corrupt_data, deflate_encode_buffer_, deflate_encode_len_);
 328
 329   int pos = corrupt_data_len / 2;
 330   corrupt_data[pos] = !corrupt_data[pos];
 331
 332   // Decode the corrupted data with filter
 333   InitFilter(Filter::FILTER_TYPE_DEFLATE);
 334   char corrupt_decode_buffer[kDefaultBufferSize];
 335   int corrupt_decode_size = kDefaultBufferSize;
 336
 337   int code = DecodeAllWithFilter(filter_.get(), corrupt_data, corrupt_data_len,
 338                                  corrupt_decode_buffer, &corrupt_decode_size);
 339
 340   // Expect failures
 341   EXPECT_TRUE(code == Filter::FILTER_ERROR);
 342 }
 343
 344 // Decoding deflate stream with missing data.
 345 TEST_F(GZipUnitTest, DecodeMissingData) {
 346   char corrupt_data[kDefaultBufferSize];
 347   int corrupt_data_len = deflate_encode_len_;
 348   memcpy(corrupt_data, deflate_encode_buffer_, deflate_encode_len_);
 349
 350   int pos = corrupt_data_len / 2;
 351   int len = corrupt_data_len - pos - 1;
 352   memmove(&corrupt_data[pos], &corrupt_data[pos+1], len);
 353   --corrupt_data_len;
 354
 355   // Decode the corrupted data with filter
 356   InitFilter(Filter::FILTER_TYPE_DEFLATE);
 357   char corrupt_decode_buffer[kDefaultBufferSize];
 358   int corrupt_decode_size = kDefaultBufferSize;
 359
 360   int code = DecodeAllWithFilter(filter_.get(), corrupt_data, corrupt_data_len,
 361                                  corrupt_decode_buffer, &corrupt_decode_size);
 362
 363   // Expect failures
 364   EXPECT_EQ(Filter::FILTER_ERROR, code);
 365 }
 366
 367 // Decoding gzip stream with corrupted header.
 368 TEST_F(GZipUnitTest, DecodeCorruptedHeader) {
 369   char corrupt_data[kDefaultBufferSize];
 370   int corrupt_data_len = gzip_encode_len_;
 371   memcpy(corrupt_data, gzip_encode_buffer_, gzip_encode_len_);
 372
 373   corrupt_data[2] = !corrupt_data[2];
 374
 375   // Decode the corrupted data with filter
 376   InitFilter(Filter::FILTER_TYPE_GZIP);
 377   char corrupt_decode_buffer[kDefaultBufferSize];
 378   int corrupt_decode_size = kDefaultBufferSize;
 379
 380   int code = DecodeAllWithFilter(filter_.get(), corrupt_data, corrupt_data_len,
 381                                  corrupt_decode_buffer, &corrupt_decode_size);
 382
 383   // Expect failures
 384   EXPECT_TRUE(code == Filter::FILTER_ERROR);
 385 }
 386
 387 }  // namespace net