Upstream WebAssembly VM and Null VM from envoyproxy/envoy-wasm. (#8020)

Description: Upstream from envoyproxy/envoy-wasm the WebAssembly VM support along with the Null VM support and tests. This is the first PR dealing with WebAssembly filter support in envoy.  See https://github.com/envoyproxy/envoy-wasm/blob/master/WASM.md and https://github.com/envoyproxy/envoy-wasm/blob/master/docs/root/api-v2/config/wasm/wasm.rst for details.
Risk Level: Medium
Testing: Unit tests.
Docs Changes: N/A
Release Notes: N/A
Part of #4272 

Signed-off-by: John Plevyak <jplevyak@gmail.com>

CODEOWNERS

@@ -55,3 +55,5 @@ extensions/filters/common/original_src @snowp @klarose
 /*/extensions/filters/listener/http_inspector @crazyxy @PiotrSikora @lizan
 # attribute context
 /*/extensions/filters/common/expr @kyessenov @yangminzhu
+# webassembly common extension
+/*/extensions/common/wasm @jplevyak @PiotrSikora

source/common/common/logger.h

@@ -60,7 +60,8 @@ namespace Logger {
   FUNCTION(thrift)               \
   FUNCTION(tracing)              \
   FUNCTION(upstream)             \
-  FUNCTION(udp)           
+  FUNCTION(udp)                  \
+  FUNCTION(wasm)
 
 enum class Id {
   ALL_LOGGER_IDS(GENERATE_ENUM)

source/extensions/common/wasm/BUILD

@@ -0,0 +1,36 @@
+licenses(["notice"])  # Apache 2
+
+load(
+    "//bazel:envoy_build_system.bzl",
+    "envoy_cc_library",
+    "envoy_package",
+)
+
+envoy_package()
+
+envoy_cc_library(
+    name = "well_known_names",
+    hdrs = ["well_known_names.h"],
+    deps = [
+        "//source/common/singleton:const_singleton",
+    ],
+)
+
+envoy_cc_library(
+    name = "wasm_vm_interface",
+    hdrs = ["wasm_vm.h"],
+    deps = [
+        ":well_known_names",
+        "//source/common/common:minimal_logger_lib",
+    ],
+)
+
+envoy_cc_library(
+    name = "wasm_vm_lib",
+    srcs = ["wasm_vm.cc"],
+    deps = [
+        ":wasm_vm_interface",
+        "//source/common/common:assert_lib",
+        "//source/extensions/common/wasm/null:null_lib",
+    ],
+)

source/extensions/common/wasm/null/BUILD

@@ -0,0 +1,47 @@
+licenses(["notice"])  # Apache 2
+
+load(
+    "//bazel:envoy_build_system.bzl",
+    "envoy_cc_library",
+    "envoy_package",
+)
+
+envoy_package()
+
+envoy_cc_library(
+    name = "null_vm_plugin_interface",
+    hdrs = ["null_vm_plugin.h"],
+    deps = [
+        "//source/extensions/common/wasm:wasm_vm_interface",
+        "//source/extensions/common/wasm:well_known_names",
+    ],
+)
+
+envoy_cc_library(
+    name = "null_vm_lib",
+    srcs = ["null_vm.cc"],
+    hdrs = ["null_vm.h"],
+    deps = [
+        ":null_vm_plugin_interface",
+        "//external:abseil_node_hash_map",
+        "//include/envoy/registry",
+        "//source/common/common:assert_lib",
+        "//source/extensions/common/wasm:wasm_vm_interface",
+        "//source/extensions/common/wasm:well_known_names",
+    ],
+)
+
+envoy_cc_library(
+    name = "null_lib",
+    srcs = ["null.cc"],
+    hdrs = ["null.h"],
+    deps = [
+        ":null_vm_lib",
+        ":null_vm_plugin_interface",
+        "//external:abseil_node_hash_map",
+        "//include/envoy/registry",
+        "//source/common/common:assert_lib",
+        "//source/extensions/common/wasm:wasm_vm_interface",
+        "//source/extensions/common/wasm:well_known_names",
+    ],
+)

source/extensions/common/wasm/null/null.cc

@@ -0,0 +1,27 @@
+#include "extensions/common/wasm/null/null.h"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "envoy/registry/registry.h"
+
+#include "common/common/assert.h"
+
+#include "extensions/common/wasm/null/null_vm.h"
+#include "extensions/common/wasm/null/null_vm_plugin.h"
+#include "extensions/common/wasm/well_known_names.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Common {
+namespace Wasm {
+namespace Null {
+
+WasmVmPtr createVm() { return std::make_unique<NullVm>(); }
+
+} // namespace Null
+} // namespace Wasm
+} // namespace Common
+} // namespace Extensions
+} // namespace Envoy

source/extensions/common/wasm/null/null.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <memory>
+
+#include "extensions/common/wasm/null/null_vm_plugin.h"
+#include "extensions/common/wasm/wasm_vm.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Common {
+namespace Wasm {
+namespace Null {
+
+WasmVmPtr createVm();
+
+} // namespace Null
+} // namespace Wasm
+} // namespace Common
+} // namespace Extensions
+} // namespace Envoy

source/extensions/common/wasm/null/null_vm.cc

@@ -0,0 +1,104 @@
+#include "extensions/common/wasm/null/null_vm.h"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "envoy/registry/registry.h"
+
+#include "common/common/assert.h"
+
+#include "extensions/common/wasm/null/null_vm_plugin.h"
+#include "extensions/common/wasm/well_known_names.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Common {
+namespace Wasm {
+namespace Null {
+
+WasmVmPtr NullVm::clone() {
+  auto cloned_null_vm = std::make_unique<NullVm>(*this);
+  cloned_null_vm->load(plugin_name_, false /* unused */);
+  return cloned_null_vm;
+}
+
+// "Load" the plugin by obtaining a pointer to it from the factory.
+bool NullVm::load(const std::string& name, bool /* allow_precompiled */) {
+  auto factory = Registry::FactoryRegistry<NullVmPluginFactory>::getFactory(name);
+  if (!factory) {
+    return false;
+  }
+  plugin_name_ = name;
+  plugin_ = factory->create();
+  return true;
+}
+
+void NullVm::link(absl::string_view /* name */, bool /* needs_emscripten */) {}
+
+void NullVm::makeModule(absl::string_view /* name */) {
+  // NullVm does not advertise code as emscripten so this will not get called.
+  NOT_REACHED_GCOVR_EXCL_LINE;
+}
+
+void NullVm::start(Common::Wasm::Context* context) {
+  SaveRestoreContext saved_context(context);
+  plugin_->start();
+}
+
+uint64_t NullVm::getMemorySize() { return std::numeric_limits<uint64_t>::max(); }
+
+// NulVm pointers are just native pointers.
+absl::optional<absl::string_view> NullVm::getMemory(uint64_t pointer, uint64_t size) {
+  if (pointer == 0 && size != 0) {
+    return absl::nullopt;
+  }
+  return absl::string_view(reinterpret_cast<char*>(pointer), static_cast<size_t>(size));
+}
+
+bool NullVm::getMemoryOffset(void* host_pointer, uint64_t* vm_pointer) {
+  *vm_pointer = reinterpret_cast<uint64_t>(host_pointer);
+  return true;
+}
+
+bool NullVm::setMemory(uint64_t pointer, uint64_t size, const void* data) {
+  if ((pointer == 0 || data == nullptr)) {
+    if (size != 0) {
+      return false;
+    } else {
+      return true;
+    }
+  }
+  auto p = reinterpret_cast<char*>(pointer);
+  memcpy(p, data, size);
+  return true;
+}
+
+bool NullVm::setWord(uint64_t pointer, Word data) {
+  if (pointer == 0) {
+    return false;
+  }
+  auto p = reinterpret_cast<char*>(pointer);
+  memcpy(p, &data.u64_, sizeof(data.u64_));
+  return true;
+}
+
+bool NullVm::getWord(uint64_t pointer, Word* data) {
+  if (pointer == 0) {
+    return false;
+  }
+  auto p = reinterpret_cast<char*>(pointer);
+  memcpy(&data->u64_, p, sizeof(data->u64_));
+  return true;
+}
+
+absl::string_view NullVm::getUserSection(absl::string_view /* name */) {
+  // Return nothing: there is no WASM file.
+  return {};
+}
+
+} // namespace Null
+} // namespace Wasm
+} // namespace Common
+} // namespace Extensions
+} // namespace Envoy

source/extensions/common/wasm/null/null_vm.h

@@ -0,0 +1,75 @@
+#pragma once
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "envoy/registry/registry.h"
+
+#include "common/common/assert.h"
+
+#include "extensions/common/wasm/null/null_vm_plugin.h"
+#include "extensions/common/wasm/well_known_names.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Common {
+namespace Wasm {
+namespace Null {
+
+// The NullVm wraps a C++ WASM plugin which has been compiled with the WASM API
+// and linked directly into the Envoy process. This is useful for development
+// in that it permits the debugger to set breakpoints in both Envoy and the plugin.
+struct NullVm : public WasmVm {
+  NullVm() = default;
+  NullVm(const NullVm& other) : plugin_name_(other.plugin_name_) {}
+
+  // WasmVm
+  absl::string_view vm() override { return WasmVmNames::get().Null; }
+  bool cloneable() override { return true; };
+  WasmVmPtr clone() override;
+  bool load(const std::string& code, bool allow_precompiled) override;
+  void link(absl::string_view debug_name, bool needs_emscripten) override;
+  void setMemoryLayout(uint64_t, uint64_t, uint64_t) override {}
+  void start(Common::Wasm::Context* context) override;
+  uint64_t getMemorySize() override;
+  absl::optional<absl::string_view> getMemory(uint64_t pointer, uint64_t size) override;
+  bool getMemoryOffset(void* host_pointer, uint64_t* vm_pointer) override;
+  bool setMemory(uint64_t pointer, uint64_t size, const void* data) override;
+  bool setWord(uint64_t pointer, Word data) override;
+  bool getWord(uint64_t pointer, Word* data) override;
+  void makeModule(absl::string_view name) override;
+  absl::string_view getUserSection(absl::string_view name) override;
+
+#define _FORWARD_GET_FUNCTION(_T)                                                                  \
+  void getFunction(absl::string_view function_name, _T* f) override {                              \
+    plugin_->getFunction(function_name, f);                                                        \
+  }
+  FOR_ALL_WASM_VM_EXPORTS(_FORWARD_GET_FUNCTION)
+#undef _FORWARD_GET_FUNCTION
+
+  // These are not needed for NullVm which invokes the handlers directly.
+#define _REGISTER_CALLBACK(_T)                                                                     \
+  void registerCallback(absl::string_view, absl::string_view, _T,                                  \
+                        typename ConvertFunctionTypeWordToUint32<_T>::type) override{};
+  FOR_ALL_WASM_VM_IMPORTS(_REGISTER_CALLBACK)
+#undef _REGISTER_CALLBACK
+
+  // NullVm does not advertise code as emscripten so this will not get called.
+  std::unique_ptr<Global<double>> makeGlobal(absl::string_view, absl::string_view,
+                                             double) override {
+    NOT_REACHED_GCOVR_EXCL_LINE;
+  };
+  std::unique_ptr<Global<Word>> makeGlobal(absl::string_view, absl::string_view, Word) override {
+    NOT_REACHED_GCOVR_EXCL_LINE;
+  };
+
+  std::string plugin_name_;
+  std::unique_ptr<NullVmPlugin> plugin_;
+};
+
+} // namespace Null
+} // namespace Wasm
+} // namespace Common
+} // namespace Extensions
+} // namespace Envoy

source/extensions/common/wasm/null/null_vm_plugin.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "extensions/common/wasm/wasm_vm.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Common {
+namespace Wasm {
+namespace Null {
+
+// A wrapper for the natively compiled NullVm plugin which implements the WASM ABI.
+class NullVmPlugin {
+public:
+  NullVmPlugin() = default;
+  virtual ~NullVmPlugin() = default;
+
+  // NB: These are defined rather than declared PURE because gmock uses __LINE__ internally for
+  // uniqueness, making it impossible to use FOR_ALL_WASM_VM_EXPORTS with MOCK_METHOD2.
+#define _DEFINE_GET_FUNCTION(_T)                                                                   \
+  virtual void getFunction(absl::string_view, _T* f) { *f = nullptr; }
+  FOR_ALL_WASM_VM_EXPORTS(_DEFINE_GET_FUNCTION)
+#undef _DEFIN_GET_FUNCTIONE
+
+  virtual void start() PURE;
+};
+
+/**
+ * Pseudo-WASM plugins using the NullVM should implement this factory and register via
+ * Registry::registerFactory or the convenience class RegisterFactory.
+ */
+class NullVmPluginFactory {
+public:
+  virtual ~NullVmPluginFactory() = default;
+
+  /**
+   * Name of the plugin.
+   */
+  virtual const std::string name() const PURE;
+
+  /**
+   * Create an instance of the plugin.
+   */
+  virtual std::unique_ptr<NullVmPlugin> create() const PURE;
+};
+
+} // namespace Null
+} // namespace Wasm
+} // namespace Common
+} // namespace Extensions
+} // namespace Envoy