Add TopicTree fuzz target

fuzzing/Makefile

@@ -10,6 +10,7 @@ oss-fuzz:
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 WebSocket.cpp -o $(OUT)/WebSocket $(LIB_FUZZING_ENGINE)
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 Http.cpp -o $(OUT)/Http $(LIB_FUZZING_ENGINE)
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 PerMessageDeflate.cpp -o $(OUT)/PerMessageDeflate $(LIB_FUZZING_ENGINE) -lz
+	$(CXX) $(CXXFLAGS) -std=c++17 -O3 TopicTree.cpp -o $(OUT)/TopicTree $(LIB_FUZZING_ENGINE)
 # "Integration tests"
 	$(CC) $(CFLAGS) -DLIBUS_NO_SSL -c -O3 uSocketsMock.c
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 -DLIBUS_NO_SSL -I../src -I../uSockets/src MockedHelloWorld.cpp uSocketsMock.o -lz -o $(OUT)/MockedHelloWorld $(LIB_FUZZING_ENGINE)

fuzzing/TopicTree.cpp

@@ -0,0 +1,67 @@
+#define WIN32_EXPORT
+
+#include "helpers.h"
+
+/* Test for the topic tree */
+#include "../src/TopicTree.h"
+
+#include <memory>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    /* Create topic tree */
+    uWS::TopicTree topicTree([](uWS::Subscriber *s, std::string_view message) {
+        /* We assume sane output */
+        if (!s || !message.length()) {
+            free((void *) -1);
+        }
+
+        return 0;
+    });
+
+    /* Holder for all manually allocated subscribers */
+    std::map<uint32_t, std::unique_ptr<uWS::Subscriber>> subscribers;
+
+    /* Iterate the padded fuzz as chunks */
+    makeChunked(makePadded(data, size), size, [&topicTree, &subscribers](const uint8_t *data, size_t size) {
+        /* We need at least 5 bytes */
+        if (size > 4) {
+            /* Last of all is a string */
+            std::string_view lastString((char *) data + 5, size - 5);
+
+            /* First 4 bytes is the subscriber id */
+            uint32_t id;
+            memcpy(&id, data, 4);
+
+            /* Then one byte action */
+            if (data[4] == 'S') {
+                /* Subscribe */
+                if (subscribers.find(id) != subscribers.end()) {
+                    uWS::Subscriber *subscriber = new uWS::Subscriber(nullptr);
+                    subscribers[id] = std::unique_ptr<uWS::Subscriber>(subscriber);
+                    topicTree.subscribe(lastString, subscriber);
+                }
+            } else if (data[4] == 'U') {
+                /* Unsubscribe */
+                auto it = subscribers.find(id);
+                if (it != subscribers.end()) {
+                    topicTree.unsubscribe(lastString, it->second.get());
+                }
+            } else if (data[4] == 'A') {
+                /* Unsubscribe from all */
+                auto it = subscribers.find(id);
+                if (it != subscribers.end()) {
+                    topicTree.unsubscribeAll(it->second.get());
+                }
+            } else if (data[4] == 'P') {
+                /* Publish */
+                topicTree.publish(lastString, lastString);
+            } else if (data[4] == 'D') {
+                /* Drain */
+                topicTree.drain();
+            }
+        }
+    });
+
+    return 0;
+}
+