Add libEpollFuzzer and a new fuzz target

fuzzing/EpollHelloWorld.cpp

@@ -0,0 +1,69 @@
+/* We rely on wrapped syscalls */
+#include "libEpollFuzzer/epoll_fuzzer.h"
+
+#include "App.h"
+
+/* We keep this one for teardown later on */
+struct us_listen_socket_t *listen_socket;
+
+/* This test is run by libEpollFuzzer */
+void test() {
+	/* ws->getUserData returns one of these */
+    struct PerSocketData {
+        /* Fill with user data */
+    };
+
+    /* Keep in mind that uWS::SSLApp({options}) is the same as uWS::App() when compiled without SSL support.
+     * You may swap to using uWS:App() if you don't need SSL */
+    uWS::App({
+        /* There are example certificates in uWebSockets.js repo */
+	    .key_file_name = "../misc/key.pem",
+	    .cert_file_name = "../misc/cert.pem",
+	    .passphrase = "1234"
+	}).ws<PerSocketData>("/*", {
+        /* Settings */
+        .compression = uWS::SHARED_COMPRESSOR,
+        .maxPayloadLength = 16 * 1024,
+        .idleTimeout = 10,
+        .maxBackpressure = 1 * 1024 * 1024,
+        /* Handlers */
+        .open = [](auto *ws) {
+            /* Open event here, you may access ws->getUserData() which points to a PerSocketData struct */
+        },
+        .message = [](auto *ws, std::string_view message, uWS::OpCode opCode) {
+            ws->send(message, opCode, true);
+        },
+        .drain = [](auto *ws) {
+            /* Check ws->getBufferedAmount() here */
+        },
+        .ping = [](auto *ws) {
+            /* Not implemented yet */
+        },
+        .pong = [](auto *ws) {
+            /* Not implemented yet */
+        },
+        .close = [](auto *ws, int code, std::string_view message) {
+            /* You may access ws->getUserData() here */
+        }
+    }).listen(9001, [](auto *listenSocket) {
+		listen_socket = listenSocket;
+    }).run();
+
+	uWS::Loop::get()->free();
+}
+
+/* Thus function should shutdown the event-loop and let the test fall through */
+void teardown() {
+	/* If we are called twice there's a bug (it potentially could if
+	 * all open sockets cannot be error-closed in one epoll_wait call).
+	 * But we only allow 1k FDs and we have a buffer of 1024 from epoll_wait */
+	if (!listen_socket) {
+		exit(-1);
+	}
+
+	/* We might have open sockets still, and these will be error-closed by epoll_wait */
+	// us_socket_context_close - close all open sockets created with this socket context
+
+	us_listen_socket_close(0, listen_socket);
+	listen_socket = NULL;
+}