fuzz: try to be a little bit faster (#2559)

Some fuzzers don't really need a real and complete local context.
Try to avoid setting it up, creating a simpler fake version with only the
features really needed.
That is a kind of experiment: if it works, we can extend the same logic
to other fuzzers

2 files changed, 25 insertions, 7 deletions

diff --git a/example/reader_util.c b/example/reader_util.c
index 71f5ed39d..d38850fc4 100644
--- a/example/reader_util.c
+++ b/example/reader_util.c
@@ -372,6 +372,9 @@ int parse_proto_name_list(char *str, NDPI_PROTOCOL_BITMASK *bitmask, int inverte
     return 1;
   NDPI_BITMASK_SET_ALL(all);
   ndpi_set_protocol_detection_bitmask2(module, &all);
+  /* Try to be fast: we need only the protocol name -> protocol id mapping! */
+  ndpi_set_config(module, "any", "ip_list.load", "0");
+  ndpi_set_config(module, NULL, "flow_risk_lists.load", "0");
   ndpi_finalize_initialization(module);
 
   for(n = strtok(str,_proto_delim); n && *n; n = strtok(NULL,_proto_delim)) {
diff --git a/fuzz/fuzz_filecfg_malicious_sha1.c b/fuzz/fuzz_filecfg_malicious_sha1.c
index 6685b5d6e..5940dd7af 100644
--- a/fuzz/fuzz_filecfg_malicious_sha1.c
+++ b/fuzz/fuzz_filecfg_malicious_sha1.c
@@ -2,26 +2,41 @@
 #include "ndpi_private.h"
 #include "fuzz_common_code.h"
 
+#ifdef NDPI_ENABLE_DEBUG_MESSAGES
+void ndpi_debug_printf(unsigned int proto, struct ndpi_detection_module_struct *ndpi_str, ndpi_log_level_t log_level,
+                       const char *file_name, const char *func_name, unsigned int line_number, const char *format, ...);
+#endif
+
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   struct ndpi_detection_module_struct *ndpi_struct;
   FILE *fd;
-  NDPI_PROTOCOL_BITMASK all;
 
   /* To allow memory allocation failures */
   fuzz_set_alloc_callbacks_and_seed(size);
 
-  ndpi_struct = ndpi_init_detection_module(NULL);
-  NDPI_BITMASK_SET_ALL(all);
-  ndpi_set_protocol_detection_bitmask2(ndpi_struct, &all);
+  /* We don't need a complete (and costly to set up) context!
+     Setting up manually only what is really needed is complex (and error prone!)
+     but allow us to be significant faster and to have better coverage */
+
+  /* TODO: if it works, we can extend the same logic to other fuzzers */
 
-  ndpi_set_config(ndpi_struct, NULL, "log.level", "3");
-  ndpi_set_config(ndpi_struct, "all", "log", "1");
+  ndpi_struct = ndpi_calloc(1, sizeof(struct ndpi_detection_module_struct));
+
+#ifdef NDPI_ENABLE_DEBUG_MESSAGES
+  set_ndpi_debug_function(ndpi_struct, (ndpi_debug_function_ptr)ndpi_debug_printf);
+#endif
+  if(ndpi_struct)
+    ndpi_struct->cfg.log_level = NDPI_LOG_DEBUG_EXTRA;
 
   fd = buffer_to_file(data, size);
   load_malicious_sha1_file_fd(ndpi_struct, fd);
   if(fd)
     fclose(fd);
 
-  ndpi_exit_detection_module(ndpi_struct);
+  /* We also need to manually free anything! */
+  if(ndpi_struct && ndpi_struct->malicious_sha1_hashmap)
+    ndpi_hash_free(&ndpi_struct->malicious_sha1_hashmap);
+  ndpi_free(ndpi_struct);
+
   return 0;
 }