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-rw-r--r--tools/fuzzing/nyx/Nyx.cpp206
1 files changed, 206 insertions, 0 deletions
diff --git a/tools/fuzzing/nyx/Nyx.cpp b/tools/fuzzing/nyx/Nyx.cpp
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+++ b/tools/fuzzing/nyx/Nyx.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Unused.h"
+#include "mozilla/Vector.h"
+#include "mozilla/fuzzing/Nyx.h"
+#include "prinrval.h"
+#include "prthread.h"
+
+#include <algorithm>
+#include <fstream>
+
+#include <unistd.h>
+
+namespace mozilla {
+namespace fuzzing {
+
+Nyx::Nyx() {}
+
+// static
+Nyx& Nyx::instance() {
+ static Nyx nyx;
+ return nyx;
+}
+
+extern "C" {
+MOZ_EXPORT __attribute__((weak)) void nyx_start(void);
+MOZ_EXPORT __attribute__((weak)) uint32_t nyx_get_next_fuzz_data(void*,
+ uint32_t);
+MOZ_EXPORT __attribute__((weak)) void nyx_release(uint32_t);
+MOZ_EXPORT __attribute__((weak)) void nyx_handle_event(const char*, const char*,
+ int, const char*);
+MOZ_EXPORT __attribute__((weak)) void nyx_puts(const char*);
+}
+
+/*
+ * In this macro, we must avoid calling MOZ_CRASH and friends, as these
+ * calls will redirect to the Nyx event handler routines. If the library
+ * is not properly preloaded, we will crash in the process. Instead, emit
+ * a descriptive error and then force a crash that won't be redirected.
+ */
+#define NYX_CHECK_API(func) \
+ if (!func) { \
+ fprintf( \
+ stderr, \
+ "Error: Nyx library must be in LD_PRELOAD. Missing function \"%s\"\n", \
+ #func); \
+ MOZ_REALLY_CRASH(__LINE__); \
+ }
+
+void Nyx::start(void) {
+ MOZ_RELEASE_ASSERT(!mInited);
+ mInited = true;
+
+ // Check if we are in replay mode.
+ char* testFilePtr = getenv("MOZ_FUZZ_TESTFILE");
+ if (testFilePtr) {
+ mReplayMode = true;
+
+ MOZ_FUZZING_NYX_PRINT("[Replay Mode] Reading data file...\n");
+
+ std::string testFile(testFilePtr);
+ std::ifstream is;
+ is.open(testFile, std::ios::binary);
+
+ uint64_t chksum, num_ops, num_data, op_offset, data_offset;
+
+ // If only C++ supported streaming operators on binary files...
+ is.read(reinterpret_cast<char*>(&chksum), sizeof(uint64_t));
+ is.read(reinterpret_cast<char*>(&num_ops), sizeof(uint64_t));
+ is.read(reinterpret_cast<char*>(&num_data), sizeof(uint64_t));
+ is.read(reinterpret_cast<char*>(&op_offset), sizeof(uint64_t));
+ is.read(reinterpret_cast<char*>(&data_offset), sizeof(uint64_t));
+
+ if (!is.good()) {
+ MOZ_FUZZING_NYX_PRINT("[Replay Mode] Error reading input file.\n");
+ _exit(1);
+ }
+
+ is.seekg(data_offset);
+
+ // The data chunks we receive through Nyx are stored in the data
+ // section of the testfile as chunks prefixed with a 16-bit data
+ // length. We read all chunks and store them away to simulate how
+ // we originally received the data via Nyx.
+
+ while (is.good()) {
+ uint16_t pktsize;
+ is.read(reinterpret_cast<char*>(&pktsize), sizeof(uint16_t));
+
+ if (!is.good()) {
+ break;
+ }
+
+ auto buffer = new Vector<uint8_t>();
+
+ mozilla::Unused << buffer->initLengthUninitialized(pktsize);
+ is.read(reinterpret_cast<char*>(buffer->begin()), buffer->length());
+
+ MOZ_FUZZING_NYX_PRINTF("[Replay Mode] Read data packet of size %zu\n",
+ buffer->length());
+
+ mReplayBuffers.push_back(buffer);
+ }
+
+ if (!mReplayBuffers.size()) {
+ MOZ_FUZZING_NYX_PRINT("[Replay Mode] Error: No buffers read.\n");
+ _exit(1);
+ }
+
+ is.close();
+
+ if (!!getenv("MOZ_FUZZ_WAIT_BEFORE_REPLAY")) {
+ // This can be useful in some cases to reproduce intermittent issues.
+ PR_Sleep(PR_MillisecondsToInterval(5000));
+ }
+
+ return;
+ }
+
+ NYX_CHECK_API(nyx_start);
+ NYX_CHECK_API(nyx_get_next_fuzz_data);
+ NYX_CHECK_API(nyx_release);
+ NYX_CHECK_API(nyx_handle_event);
+ NYX_CHECK_API(nyx_puts);
+
+ nyx_start();
+}
+
+bool Nyx::started(void) { return mInited; }
+
+bool Nyx::is_enabled(const char* identifier) {
+ static char* fuzzer = getenv("NYX_FUZZER");
+ if (!fuzzer || strcmp(fuzzer, identifier)) {
+ return false;
+ }
+ return true;
+}
+
+bool Nyx::is_replay() { return mReplayMode; }
+
+uint32_t Nyx::get_data(uint8_t* data, uint32_t size) {
+ MOZ_RELEASE_ASSERT(mInited);
+
+ if (mReplayMode) {
+ if (!mReplayBuffers.size()) {
+ return 0xFFFFFFFF;
+ }
+
+ Vector<uint8_t>* buffer = mReplayBuffers.front();
+ mReplayBuffers.pop_front();
+
+ size = std::min(size, (uint32_t)buffer->length());
+ memcpy(data, buffer->begin(), size);
+
+ delete buffer;
+
+ return size;
+ }
+
+ return nyx_get_next_fuzz_data(data, size);
+}
+
+void Nyx::release(uint32_t iterations) {
+ MOZ_RELEASE_ASSERT(mInited);
+
+ if (mReplayMode) {
+ MOZ_FUZZING_NYX_PRINT("[Replay Mode] Nyx::release() called.\n");
+
+ // If we reach this point in replay mode, we are essentially done.
+ // Let's wait a bit further for things to settle and then exit.
+ PR_Sleep(PR_MillisecondsToInterval(5000));
+ _exit(1);
+ }
+
+ MOZ_FUZZING_NYX_DEBUG("[DEBUG] Nyx::release() called.\n");
+
+ nyx_release(iterations);
+}
+
+void Nyx::handle_event(const char* type, const char* file, int line,
+ const char* reason) {
+ if (mReplayMode) {
+ MOZ_FUZZING_NYX_PRINTF(
+ "[Replay Mode] Nyx::handle_event() called: %s at %s:%d : %s\n", type,
+ file, line, reason);
+ return;
+ }
+
+ if (mInited) {
+ nyx_handle_event(type, file, line, reason);
+ } else {
+ // We can have events such as MOZ_CRASH even before we snapshot.
+ // Output some useful information to make it clear where it happened.
+ MOZ_FUZZING_NYX_PRINTF(
+ "[ERROR] PRE SNAPSHOT Nyx::handle_event() called: %s at %s:%d : %s\n",
+ type, file, line, reason);
+ }
+}
+
+} // namespace fuzzing
+} // namespace mozilla