add mkvparser_fuzzer.cc

this isn't hooked up to cmake, but can be built similarly to webm_parser
webm_fuzzer.cc

PiperOrigin-RevId: 415639383
PiperOrigin-RevId: 416349966
Change-Id: I89b744e129442321a15b623ebc04811ca629d5b6

1 files changed, 111 insertions, 0 deletions

diff --git a/testing/mkvparser_fuzzer.cc b/testing/mkvparser_fuzzer.cc
new file mode 100644
index 0000000..a1a47b8
--- /dev/null
+++ b/testing/mkvparser_fuzzer.cc
@@ -0,0 +1,111 @@
+// Copyright (c) 2022 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <memory>
+#include <new>
+
+#include "mkvparser/mkvparser.h"
+#include "mkvparser/mkvreader.h"
+
+namespace {
+
+class MemoryReader : public mkvparser::IMkvReader {
+ public:
+  MemoryReader(const uint8_t* data, size_t size) : data_(data), size_(size) {}
+
+  int Read(long long pos, long len, unsigned char* buf) override {
+    if (pos < 0 || len < 0) {
+      abort();
+    }
+    if (pos >= size_ || size_ - pos < len) {
+      return -1;
+    }
+    memcpy(buf, data_ + pos, len);
+    return 0;
+  }
+
+  int Length(long long* total, long long* available) override {
+    if (total != nullptr) {
+      *total = size_;
+    }
+    if (available != nullptr) {
+      *available = size_;
+    }
+    return 0;
+  }
+
+ private:
+  const uint8_t* data_;
+  size_t size_;
+};
+
+void ParseCues(const mkvparser::Segment& segment) {
+  const mkvparser::Cues* const cues = segment.GetCues();
+  if (cues == nullptr) {
+    return;
+  }
+
+  while (!cues->DoneParsing()) {
+    cues->LoadCuePoint();
+  }
+}
+
+void ParseCluster(const mkvparser::Cluster& cluster) {
+  const mkvparser::BlockEntry* block_entry;
+  long status = cluster.GetFirst(block_entry);
+  if (status != 0) {
+    return;
+  }
+
+  while (block_entry != nullptr && !block_entry->EOS()) {
+    const mkvparser::Block* const block = block_entry->GetBlock();
+    if (block == nullptr) {
+      return;
+    }
+
+    status = cluster.GetNext(block_entry, block_entry);
+    if (status != 0) {
+      return;
+    }
+  }
+}
+
+}  // namespace
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  MemoryReader reader(data, size);
+
+  long long int pos = 0;
+  std::unique_ptr<mkvparser::EBMLHeader> ebml_header(
+      new (std::nothrow) mkvparser::EBMLHeader());  // NOLINT
+  if (ebml_header->Parse(&reader, pos) < 0) {
+    return 0;
+  }
+
+  mkvparser::Segment* temp_segment;
+  if (mkvparser::Segment::CreateInstance(&reader, pos, temp_segment) != 0) {
+    return 0;
+  }
+  std::unique_ptr<mkvparser::Segment> segment(temp_segment);
+
+  if (segment->Load() < 0) {
+    return 0;
+  }
+
+  const mkvparser::Cluster* cluster = segment->GetFirst();
+  while (cluster != nullptr && !cluster->EOS()) {
+    ParseCluster(*cluster);
+    cluster = segment->GetNext(cluster);
+  }
+  ParseCues(*segment);
+
+  return 0;
+}