Add plugins (#27)

plugins/wasm-cpp/extensions/bot_detect/plugin.h

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2022 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+
+#include <string>
+#include <unordered_map>
+
+#include "common/http_util.h"
+#include "common/regex.h"
+#include "common/route_rule_matcher.h"
+#define ASSERT(_X) assert(_X)
+
+#ifndef NULL_PLUGIN
+
+#include "proxy_wasm_intrinsics.h"
+
+#else
+
+#include "include/proxy-wasm/null_plugin.h"
+
+namespace proxy_wasm {
+namespace null_plugin {
+namespace bot_detect {
+
+#endif
+
+using ReMatcher = Wasm::Common::Regex::CompiledGoogleReMatcher;
+using ReMatcherPtr = std::unique_ptr<ReMatcher>;
+
+struct BotDetectConfigRule {
+  int blocked_code = 403;
+  std::string blocked_message;
+  std::vector<ReMatcherPtr> allow;
+  std::vector<ReMatcherPtr> deny;
+};
+
+// PluginRootContext is the root context for all streams processed by the
+// thread. It has the same lifetime as the worker thread and acts as target for
+// interactions that outlives individual stream, e.g. timer, async calls.
+class PluginRootContext : public RootContext,
+                          public RouteRuleMatcher<BotDetectConfigRule> {
+ public:
+  PluginRootContext(uint32_t id, std::string_view root_id)
+      : RootContext(id, root_id) {}
+  ~PluginRootContext() {}
+  bool onConfigure(size_t) override;
+  bool checkHeader(const BotDetectConfigRule&);
+  bool configure(size_t);
+
+ private:
+  bool parsePluginConfig(const json&, BotDetectConfigRule&) override;
+
+  std::vector<ReMatcherPtr> default_matchers_;
+};
+
+// Per-stream context.
+class PluginContext : public Context {
+ public:
+  explicit PluginContext(uint32_t id, RootContext* root) : Context(id, root) {}
+  FilterHeadersStatus onRequestHeaders(uint32_t, bool) override;
+
+ private:
+  inline PluginRootContext* rootContext() {
+    return dynamic_cast<PluginRootContext*>(this->root());
+  }
+};
+
+#ifdef NULL_PLUGIN
+
+}  // namespace bot_detect
+}  // namespace null_plugin
+}  // namespace proxy_wasm
+
+#endif