1 files changed, 374 insertions, 0 deletions
diff --git a/utils/aflpp_driver/aflpp_driver.c b/utils/aflpp_driver/aflpp_driver.c
new file mode 100644
index 00000000..7289c845
--- /dev/null
+++ b/utils/aflpp_driver/aflpp_driver.c
@@ -0,0 +1,374 @@
+//===- afl_driver.cpp - a glue between AFL++ and libFuzzer ------*- C++ -* ===//
+//===----------------------------------------------------------------------===//
+
+/* This file allows to fuzz libFuzzer-style target functions
+ (LLVMFuzzerTestOneInput) with AFL++ using persistent in-memory fuzzing.
+
+Usage:
+################################################################################
+cat << EOF > test_fuzzer.cc
+#include <stddef.h>
+#include <stdint.h>
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+
+  if (size > 0 && data[0] == 'H')
+    if (size > 1 && data[1] == 'I')
+       if (size > 2 && data[2] == '!')
+       __builtin_trap();
+  return 0;
+
+}
+
+EOF
+# Build your target with -fsanitize-coverage=trace-pc-guard using fresh clang.
+clang -c aflpp_driver.c
+# Build afl-compiler-rt.o.c from the AFL distribution.
+clang -c $AFL_HOME/instrumentation/afl-compiler-rt.o.c
+# Build this file, link it with afl-compiler-rt.o.o and the target code.
+afl-clang-fast -o test_fuzzer test_fuzzer.cc afl-compiler-rt.o aflpp_driver.o
+# Run AFL:
+rm -rf IN OUT; mkdir IN OUT; echo z > IN/z;
+$AFL_HOME/afl-fuzz -i IN -o OUT ./a.out
+################################################################################
+*/
+
+#include <assert.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#ifndef __HAIKU__
+  #include <sys/syscall.h>
+#endif
+
+#include "config.h"
+#include "types.h"
+#include "cmplog.h"
+
+#ifdef _DEBUG
+  #include "hash.h"
+#endif
+
+int                   __afl_sharedmem_fuzzing = 1;
+extern unsigned int * __afl_fuzz_len;
+extern unsigned char *__afl_fuzz_ptr;
+
+// libFuzzer interface is thin, so we don't include any libFuzzer headers.
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
+__attribute__((weak)) int LLVMFuzzerInitialize(int *argc, char ***argv);
+
+// Default nop ASan hooks for manual posisoning when not linking the ASan
+// runtime
+// https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning
+__attribute__((weak)) void __asan_poison_memory_region(
+    void const volatile *addr, size_t size) {
+
+  (void)addr;
+  (void)size;
+
+}
+
+__attribute__((weak)) void __asan_unpoison_memory_region(
+    void const volatile *addr, size_t size) {
+
+  (void)addr;
+  (void)size;
+
+}
+
+__attribute__((weak)) void *__asan_region_is_poisoned(void *beg, size_t size);
+
+// Notify AFL about persistent mode.
+static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##";
+int                  __afl_persistent_loop(unsigned int);
+
+// Notify AFL about deferred forkserver.
+static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##";
+void                 __afl_manual_init();
+
+// Use this optionally defined function to output sanitizer messages even if
+// user asks to close stderr.
+__attribute__((weak)) void __sanitizer_set_report_fd(void *);
+
+// Keep track of where stderr content is being written to, so that
+// dup_and_close_stderr can use the correct one.
+static FILE *output_file;
+
+// Experimental feature to use afl_driver without AFL's deferred mode.
+// Needs to run before __afl_auto_init.
+__attribute__((constructor(0))) static void __decide_deferred_forkserver(void) {
+
+  if (getenv("AFL_DRIVER_DONT_DEFER")) {
+
+    if (unsetenv("__AFL_DEFER_FORKSRV")) {
+
+      perror("Failed to unset __AFL_DEFER_FORKSRV");
+      abort();
+
+    }
+
+  }
+
+}
+
+// If the user asks us to duplicate stderr, then do it.
+static void maybe_duplicate_stderr() {
+
+  char *stderr_duplicate_filename =
+      getenv("AFL_DRIVER_STDERR_DUPLICATE_FILENAME");
+
+  if (!stderr_duplicate_filename) return;
+
+  FILE *stderr_duplicate_stream =
+      freopen(stderr_duplicate_filename, "a+", stderr);
+
+  if (!stderr_duplicate_stream) {
+
+    fprintf(
+        stderr,
+        "Failed to duplicate stderr to AFL_DRIVER_STDERR_DUPLICATE_FILENAME");
+    abort();
+
+  }
+
+  output_file = stderr_duplicate_stream;
+
+}
+
+// Most of these I/O functions were inspired by/copied from libFuzzer's code.
+static void discard_output(int fd) {
+
+  FILE *temp = fopen("/dev/null", "w");
+  if (!temp) abort();
+  dup2(fileno(temp), fd);
+  fclose(temp);
+
+}
+
+static void close_stdout() {
+
+  discard_output(STDOUT_FILENO);
+
+}
+
+// Prevent the targeted code from writing to "stderr" but allow sanitizers and
+// this driver to do so.
+static void dup_and_close_stderr() {
+
+  int output_fileno = fileno(output_file);
+  int output_fd = dup(output_fileno);
+  if (output_fd <= 0) abort();
+  FILE *new_output_file = fdopen(output_fd, "w");
+  if (!new_output_file) abort();
+  if (!__sanitizer_set_report_fd) return;
+  __sanitizer_set_report_fd((void *)(long int)output_fd);
+  discard_output(output_fileno);
+
+}
+
+// Close stdout and/or stderr if user asks for it.
+static void maybe_close_fd_mask() {
+
+  char *fd_mask_str = getenv("AFL_DRIVER_CLOSE_FD_MASK");
+  if (!fd_mask_str) return;
+  int fd_mask = atoi(fd_mask_str);
+  if (fd_mask & 2) dup_and_close_stderr();
+  if (fd_mask & 1) close_stdout();
+
+}
+
+// Define LLVMFuzzerMutate to avoid link failures for targets that use it
+// with libFuzzer's LLVMFuzzerCustomMutator.
+size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize) {
+
+  // assert(false && "LLVMFuzzerMutate should not be called from afl_driver");
+  return 0;
+
+}
+
+// Execute any files provided as parameters.
+static int ExecuteFilesOnyByOne(int argc, char **argv) {
+
+  unsigned char *buf = (unsigned char *)malloc(MAX_FILE);
+
+  __asan_poison_memory_region(buf, MAX_FILE);
+  ssize_t prev_length = 0;
+
+  for (int i = 1; i < argc; i++) {
+
+    int fd = 0;
+
+    if (strcmp(argv[i], "-") != 0) { fd = open(argv[i], O_RDONLY); }
+
+    if (fd == -1) { continue; }
+
+#ifndef __HAIKU__
+    ssize_t length = syscall(SYS_read, fd, buf, MAX_FILE);
+#else
+    ssize_t length = _kern_read(fd, buf, MAX_FILE);
+#endif  // HAIKU
+
+    if (length > 0) {
+
+      if (length < prev_length) {
+
+        __asan_poison_memory_region(buf + length, prev_length - length);
+
+      } else {
+
+        __asan_unpoison_memory_region(buf + prev_length, length - prev_length);
+
+      }
+
+      prev_length = length;
+
+      printf("Reading %zu bytes from %s\n", length, argv[i]);
+      LLVMFuzzerTestOneInput(buf, length);
+      printf("Execution successful.\n");
+
+    }
+
+    if (fd > 0) { close(fd); }
+
+  }
+
+  free(buf);
+  return 0;
+
+}
+
+int main(int argc, char **argv) {
+
+  if (argc < 2 || strncmp(argv[1], "-h", 2) == 0)
+    printf(
+        "============================== INFO ================================\n"
+        "This binary is built for afl++.\n"
+        "To run the target function on individual input(s) execute:\n"
+        "  %s INPUT_FILE1 [INPUT_FILE2 ... ]\n"
+        "To fuzz with afl-fuzz execute:\n"
+        "  afl-fuzz [afl-flags] -- %s [-N]\n"
+        "afl-fuzz will run N iterations before re-spawning the process "
+        "(default: "
+        "INT_MAX)\n"
+        "For stdin input processing, pass '-' as single command line option.\n"
+        "For file input processing, pass '@@' as single command line option.\n"
+        "To use with afl-cmin or afl-cmin.bash pass '-' as single command line "
+        "option\n"
+        "===================================================================\n",
+        argv[0], argv[0]);
+
+  if (getenv("AFL_GDB")) {
+
+    char cmd[64];
+    snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps", getpid());
+    system(cmd);
+    fprintf(stderr, "DEBUG: aflpp_driver pid is %d\n", getpid());
+    sleep(1);
+
+  }
+
+  output_file = stderr;
+  maybe_duplicate_stderr();
+  maybe_close_fd_mask();
+  if (LLVMFuzzerInitialize) {
+
+    fprintf(stderr, "Running LLVMFuzzerInitialize ...\n");
+    LLVMFuzzerInitialize(&argc, &argv);
+    fprintf(stderr, "continue...\n");
+
+  }
+
+  // Do any other expensive one-time initialization here.
+
+  uint8_t dummy_input[64] = {0};
+  memcpy(dummy_input, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT));
+  memcpy(dummy_input + 32, (void *)AFL_DEFER_FORKSVR,
+         sizeof(AFL_DEFER_FORKSVR));
+
+  int N = INT_MAX;
+
+  if (argc == 2 && !strcmp(argv[1], "-")) {
+
+    __afl_sharedmem_fuzzing = 0;
+    __afl_manual_init();
+    return ExecuteFilesOnyByOne(argc, argv);
+
+  } else if (argc == 2 && argv[1][0] == '-') {
+
+    N = atoi(argv[1] + 1);
+
+  } else if (argc == 2 && (N = atoi(argv[1])) > 0) {
+
+    printf("WARNING: using the deprecated call style `%s %d`\n", argv[0], N);
+
+  } else if (argc > 1) {
+
+    __afl_sharedmem_fuzzing = 0;
+
+    if (argc == 2) { __afl_manual_init(); }
+
+    return ExecuteFilesOnyByOne(argc, argv);
+
+  }
+
+  assert(N > 0);
+
+  __afl_manual_init();
+
+  // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization
+  // on the first execution of LLVMFuzzerTestOneInput is ignored.
+  LLVMFuzzerTestOneInput(dummy_input, 4);
+
+  __asan_poison_memory_region(__afl_fuzz_ptr, MAX_FILE);
+  size_t prev_length = 0;
+
+  // for speed only insert asan functions if the target is linked with asan
+  if (__asan_region_is_poisoned) {
+
+    while (__afl_persistent_loop(N)) {
+
+      size_t length = *__afl_fuzz_len;
+
+      if (likely(length)) {
+
+        if (length < prev_length) {
+
+          __asan_poison_memory_region(__afl_fuzz_ptr + length,
+                                      prev_length - length);
+
+        } else if (length > prev_length) {
+
+          __asan_unpoison_memory_region(__afl_fuzz_ptr + prev_length,
+                                        length - prev_length);
+
+        }
+
+        prev_length = length;
+        LLVMFuzzerTestOneInput(__afl_fuzz_ptr, length);
+
+      }
+
+    }
+
+  } else {
+
+    while (__afl_persistent_loop(N)) {
+
+      LLVMFuzzerTestOneInput(__afl_fuzz_ptr, *__afl_fuzz_len);
+
+    }
+
+  }
+
+  return 0;
+
+}
+