3 files changed, 90 insertions, 5 deletions

diff --git a/src/afl-fuzz-mutators.c b/src/afl-fuzz-mutators.c
index b9daebfa..f3d0bc96 100644
--- a/src/afl-fuzz-mutators.c
+++ b/src/afl-fuzz-mutators.c
@@ -314,6 +314,14 @@ struct custom_mutator *load_custom_mutator(afl_state_t *afl, const char *fn) {
 
   }
 
+  /* "afl_custom_fuzz_send", optional */
+  mutator->afl_custom_fuzz_send = dlsym(dh, "afl_custom_fuzz_send");
+  if (!mutator->afl_custom_fuzz_send) {
+
+    ACTF("optional symbol 'afl_custom_fuzz_send' not found.");
+
+  }
+
   /* "afl_custom_queue_new_entry", optional */
   mutator->afl_custom_queue_new_entry = dlsym(dh, "afl_custom_queue_new_entry");
   if (!mutator->afl_custom_queue_new_entry) {
diff --git a/src/afl-fuzz-python.c b/src/afl-fuzz-python.c
index a43d80bb..54b05978 100644
--- a/src/afl-fuzz-python.c
+++ b/src/afl-fuzz-python.c
@@ -246,6 +246,8 @@ static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) {
         PyObject_GetAttrString(py_module, "havoc_mutation_probability");
     py_functions[PY_FUNC_QUEUE_GET] =
         PyObject_GetAttrString(py_module, "queue_get");
+    py_functions[PY_FUNC_FUZZ_SEND] =
+        PyObject_GetAttrString(py_module, "fuzz_send");
     py_functions[PY_FUNC_QUEUE_NEW_ENTRY] =
         PyObject_GetAttrString(py_module, "queue_new_entry");
     py_functions[PY_FUNC_INTROSPECTION] =
@@ -466,6 +468,12 @@ struct custom_mutator *load_custom_mutator_py(afl_state_t *afl,
 
   }
 
+  if (py_functions[PY_FUNC_FUZZ_SEND]) {
+
+    mutator->afl_custom_fuzz_send = fuzz_send_py;
+
+  }
+
   if (py_functions[PY_FUNC_QUEUE_NEW_ENTRY]) {
 
     mutator->afl_custom_queue_new_entry = queue_new_entry_py;
@@ -893,6 +901,43 @@ u8 queue_get_py(void *py_mutator, const u8 *filename) {
 
 }
 
+void fuzz_send_py(void *py_mutator, const u8 *buf, size_t buf_size) {
+
+  PyObject *py_args, *py_value;
+
+  py_args = PyTuple_New(1);
+  py_value = PyByteArray_FromStringAndSize(buf, buf_size);
+  if (!py_value) {
+
+    Py_DECREF(py_args);
+    FATAL("Failed to convert arguments");
+
+  }
+
+  PyTuple_SetItem(py_args, 0, py_value);
+
+  py_value = PyObject_CallObject(
+      ((py_mutator_t *)py_mutator)->py_functions[PY_FUNC_FUZZ_SEND], py_args);
+  Py_DECREF(py_args);
+
+  if (py_value != NULL) {
+
+  #if PY_MAJOR_VERSION >= 3
+    u32 retcnt = (u32)PyLong_AsLong(py_value);
+  #else
+    u32 retcnt = PyInt_AsLong(py_value);
+  #endif
+    Py_DECREF(py_value);
+
+  } else {
+
+    PyErr_Print();
+    FATAL("Call failed");
+
+  }
+
+}
+
 u8 queue_new_entry_py(void *py_mutator, const u8 *filename_new_queue,
                       const u8 *filename_orig_queue) {
 
diff --git a/src/afl-fuzz-run.c b/src/afl-fuzz-run.c
index ee4a3298..a680228d 100644
--- a/src/afl-fuzz-run.c
+++ b/src/afl-fuzz-run.c
@@ -133,9 +133,25 @@ write_to_testcase(afl_state_t *afl, void **mem, u32 len, u32 fix) {
 
     if (new_mem != *mem) { *mem = new_mem; }
 
-    /* everything as planned. use the potentially new data. */
-    afl_fsrv_write_to_testcase(&afl->fsrv, *mem, new_size);
-    len = new_size;
+    if (unlikely(afl->custom_mutators_count)) {
+
+      LIST_FOREACH(&afl->custom_mutator_list, struct custom_mutator, {
+
+        if (el->afl_custom_fuzz_send) {
+
+          el->afl_custom_fuzz_send(el->data, *mem, new_size);
+
+        }
+
+      });
+
+    } else {
+
+      /* everything as planned. use the potentially new data. */
+      afl_fsrv_write_to_testcase(&afl->fsrv, *mem, new_size);
+      len = new_size;
+
+    }
 
   } else {
 
@@ -149,8 +165,24 @@ write_to_testcase(afl_state_t *afl, void **mem, u32 len, u32 fix) {
 
     }
 
-    /* boring uncustom. */
-    afl_fsrv_write_to_testcase(&afl->fsrv, *mem, len);
+    if (unlikely(afl->custom_mutators_count)) {
+
+      LIST_FOREACH(&afl->custom_mutator_list, struct custom_mutator, {
+
+        if (el->afl_custom_fuzz_send) {
+
+          el->afl_custom_fuzz_send(el->data, *mem, len);
+
+        }
+
+      });
+
+    } else {
+
+      /* boring uncustom. */
+      afl_fsrv_write_to_testcase(&afl->fsrv, *mem, len);
+
+    }
 
   }