qemu ld_preload support and added socket_fuzzing ld_preload library

experimental/socket_fuzzing/socketfuzz.c

@@ -0,0 +1,90 @@
+/*
+ * This is desock_dup.c from the amazing preeny project
+ * https://github.com/zardus/preeny
+ *
+ * It is packaged in afl++ to have it at hand if needed
+ *
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>   //
+#include <sys/socket.h>  //
+#include <sys/stat.h>    //
+#include <fcntl.h>       //
+#include <netinet/in.h>
+#include <pthread.h>
+#include <signal.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <stdio.h>
+#include <poll.h>
+//#include "logging.h" // switche from preeny_info() to fprintf(stderr, "Info: "
+
+//
+// originals
+//
+int (*original_close)(int);
+int (*original_dup2)(int, int);
+__attribute__((constructor)) void preeny_desock_dup_orig() {
+
+  original_close = dlsym(RTLD_NEXT, "close");
+  original_dup2 = dlsym(RTLD_NEXT, "dup2");
+
+}
+
+int close(int sockfd) {
+
+  if (sockfd <= 2) {
+
+    fprintf(stderr, "Info: Disabling close on %d\n", sockfd);
+    return 0;
+
+  } else {
+
+    return original_close(sockfd);
+
+  }
+
+}
+
+int dup2(int old, int new) {
+
+  if (new <= 2) {
+
+    fprintf(stderr, "Info: Disabling dup from %d to %d\n", old, new);
+    return 0;
+
+  } else {
+
+    return original_dup2(old, new);
+
+  }
+
+}
+
+int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
+
+  fprintf(stderr, "Info: Emulating accept on %d\n", sockfd);
+  return 0;
+
+}
+
+int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen) {
+
+  fprintf(stderr, "Info: Emulating bind on port %d\n",
+          ntohs(((struct sockaddr_in *)addr)->sin_port));
+  return 0;
+
+}
+
+int listen(int sockfd, int backlog) {
+
+  return 0;
+
+}
+