Dissectors shouldn't update `flow->guessed_host_protocol_id`

The field `flow->guessed_host_protocol_id` is set at the beginning of
the flow analysis and it represents the "classification by ip" of the flow
itself.

This field should never be changed. Dissectors which want to provide an
"hint" about the classification, should update `flow->guessed_protocol_id`
instead. Such "hint" is useless if the dissector set the "extra-dissection"
data-path.

Rename such field to `guessed_protocol_id_by_ip` to better describe its
role.

Preliminary work necessary for #1687

1 files changed, 21 insertions, 21 deletions

diff --git a/src/lib/ndpi_main.c b/src/lib/ndpi_main.c
index 3922b0517..c44391c85 100644
--- a/src/lib/ndpi_main.c
+++ b/src/lib/ndpi_main.c
@@ -2270,7 +2270,7 @@ u_int8_t ndpi_is_tor_flow(struct ndpi_detection_module_struct *ndpi_str, struct
 
   if(packet->tcp != NULL) {
     if(packet->iph) {
-      if(flow->guessed_host_protocol_id == NDPI_PROTOCOL_TOR)
+      if(flow->guessed_protocol_id_by_ip == NDPI_PROTOCOL_TOR)
 	return(1);
     }
   }
@@ -5072,7 +5072,7 @@ static int ndpi_init_packet(struct ndpi_detection_module_struct *ndpi_str,
        */
       if(packet->tcp->syn != 0 && packet->tcp->ack == 0 && flow->init_finished != 0 &&
 	 flow->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN) {
-	u_int16_t guessed_protocol_id, guessed_host_protocol_id;
+	u_int16_t guessed_protocol_id, guessed_protocol_id_by_ip;
 	u_int16_t packet_direction_counter[2];
         u_int8_t num_processed_pkts;
 
@@ -5083,7 +5083,7 @@ static int ndpi_init_packet(struct ndpi_detection_module_struct *ndpi_str,
 	flow_save(packet_direction_counter[1]);
 	flow_save(num_processed_pkts);
 	flow_save(guessed_protocol_id);
-	flow_save(guessed_host_protocol_id);
+	flow_save(guessed_protocol_id_by_ip);
 
         ndpi_free_flow_data(flow);
         memset(flow, 0, sizeof(*(flow)));
@@ -5095,7 +5095,7 @@ static int ndpi_init_packet(struct ndpi_detection_module_struct *ndpi_str,
 	flow_restore(packet_direction_counter[1]);
 	flow_restore(num_processed_pkts);
 	flow_restore(guessed_protocol_id);
-	flow_restore(guessed_host_protocol_id);
+	flow_restore(guessed_protocol_id_by_ip);
 
 #undef flow_save
 #undef flow_restore
@@ -5758,13 +5758,13 @@ ndpi_protocol ndpi_detection_giveup(struct ndpi_detection_module_struct *ndpi_st
     ndpi_set_detected_protocol(ndpi_str, flow, flow->guessed_protocol_id, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI_PARTIAL);
   } else if(enable_guess) {
 
-    guessed_protocol_id = flow->guessed_protocol_id, guessed_host_protocol_id = flow->guessed_host_protocol_id;
+    guessed_protocol_id = flow->guessed_protocol_id, guessed_host_protocol_id = flow->guessed_protocol_id_by_ip;
 
     if((guessed_host_protocol_id != NDPI_PROTOCOL_UNKNOWN) &&
        ((flow->l4_proto == IPPROTO_UDP) &&
         NDPI_ISSET(&flow->excluded_protocol_bitmask, guessed_host_protocol_id) &&
         is_udp_guessable_protocol(guessed_host_protocol_id)))
-      flow->guessed_host_protocol_id = guessed_host_protocol_id = NDPI_PROTOCOL_UNKNOWN;
+      guessed_host_protocol_id = NDPI_PROTOCOL_UNKNOWN;
 
     /* Ignore guessed protocol if they have been discarded */
     if((guessed_protocol_id != NDPI_PROTOCOL_UNKNOWN)
@@ -5811,16 +5811,16 @@ ndpi_protocol ndpi_detection_giveup(struct ndpi_detection_module_struct *ndpi_st
       flow->confidence = NDPI_CONFIDENCE_MATCH_BY_PORT;
     }
 
-    if(flow->guessed_host_protocol_id != NDPI_PROTOCOL_UNKNOWN) {
+    if(flow->guessed_protocol_id_by_ip != NDPI_PROTOCOL_UNKNOWN) {
       *protocol_was_guessed = 1;
-      flow->detected_protocol_stack[0] = flow->guessed_host_protocol_id;
+      flow->detected_protocol_stack[0] = flow->guessed_protocol_id_by_ip;
       flow->confidence = NDPI_CONFIDENCE_MATCH_BY_IP;
     }
 
     if((flow->detected_protocol_stack[1] == flow->detected_protocol_stack[0]) &&
        (flow->detected_protocol_stack[1] != NDPI_PROTOCOL_UNKNOWN)) {
       *protocol_was_guessed = 1;
-      flow->detected_protocol_stack[1] = flow->guessed_host_protocol_id;
+      flow->detected_protocol_stack[1] = flow->guessed_protocol_id_by_ip;
       flow->confidence = NDPI_CONFIDENCE_MATCH_BY_IP;
     }
   }
@@ -5829,7 +5829,7 @@ ndpi_protocol ndpi_detection_giveup(struct ndpi_detection_module_struct *ndpi_st
      (flow->guessed_protocol_id == NDPI_PROTOCOL_STUN)) {
   check_stun_export:
     *protocol_was_guessed = 1;
-    ndpi_set_detected_protocol(ndpi_str, flow, flow->guessed_host_protocol_id, NDPI_PROTOCOL_STUN, NDPI_CONFIDENCE_DPI_PARTIAL);
+    ndpi_set_detected_protocol(ndpi_str, flow, flow->guessed_protocol_id_by_ip, NDPI_PROTOCOL_STUN, NDPI_CONFIDENCE_DPI_PARTIAL);
   }
 
   ret.master_protocol = flow->detected_protocol_stack[1], ret.app_protocol = flow->detected_protocol_stack[0];
@@ -6174,7 +6174,7 @@ static int ndpi_do_guess(struct ndpi_detection_module_struct *ndpi_str, struct n
 
     /* guess protocol */
     flow->guessed_protocol_id      = (int16_t) ndpi_guess_protocol_id(ndpi_str, flow, flow->l4_proto, ntohs(flow->c_port), ntohs(flow->s_port), &user_defined_proto);
-    flow->guessed_host_protocol_id = ndpi_guess_host_protocol_id(ndpi_str, flow);
+    flow->guessed_protocol_id_by_ip = ndpi_guess_host_protocol_id(ndpi_str, flow);
 
     if(ndpi_str->custom_categories.categories_loaded && packet->iph) {
       if(ndpi_str->ndpi_num_custom_protocols != 0)
@@ -6186,17 +6186,17 @@ static int ndpi_do_guess(struct ndpi_detection_module_struct *ndpi_str, struct n
     if(flow->guessed_protocol_id >= NDPI_MAX_SUPPORTED_PROTOCOLS) {
       /* This is a custom protocol and it has priority over everything else */
       ret->master_protocol = NDPI_PROTOCOL_UNKNOWN,
-      ret->app_protocol = flow->guessed_protocol_id ? flow->guessed_protocol_id : flow->guessed_host_protocol_id;
+      ret->app_protocol = flow->guessed_protocol_id ? flow->guessed_protocol_id : flow->guessed_protocol_id_by_ip;
       flow->confidence = NDPI_CONFIDENCE_MATCH_BY_PORT; /* TODO */
       ndpi_fill_protocol_category(ndpi_str, flow, ret);
       return(-1);
     }
 
     if(user_defined_proto && flow->guessed_protocol_id != NDPI_PROTOCOL_UNKNOWN) {
-      if(flow->guessed_host_protocol_id != NDPI_PROTOCOL_UNKNOWN) {
+      if(flow->guessed_protocol_id_by_ip != NDPI_PROTOCOL_UNKNOWN) {
         u_int8_t protocol_was_guessed;
 
-        /* ret->master_protocol = flow->guessed_protocol_id , ret->app_protocol = flow->guessed_host_protocol_id; /\* ****** *\/ */
+        /* ret->master_protocol = flow->guessed_protocol_id , ret->app_protocol = flow->guessed_protocol_id_by_ip; /\* ****** *\/ */
         *ret = ndpi_detection_giveup(ndpi_str, flow, 0, &protocol_was_guessed);
       }
 
@@ -6205,11 +6205,11 @@ static int ndpi_do_guess(struct ndpi_detection_module_struct *ndpi_str, struct n
     }
   }
 
-  if(flow->guessed_host_protocol_id >= NDPI_MAX_SUPPORTED_PROTOCOLS) {
+  if(flow->guessed_protocol_id_by_ip >= NDPI_MAX_SUPPORTED_PROTOCOLS) {
     NDPI_SELECTION_BITMASK_PROTOCOL_SIZE ndpi_selection_packet = {0};
 
     /* This is a custom protocol and it has priority over everything else */
-    ret->master_protocol = flow->guessed_protocol_id, ret->app_protocol = flow->guessed_host_protocol_id;
+    ret->master_protocol = flow->guessed_protocol_id, ret->app_protocol = flow->guessed_protocol_id_by_ip;
 
     flow->num_dissector_calls += ndpi_check_flow_func(ndpi_str, flow, &ndpi_selection_packet);
 
@@ -6339,9 +6339,9 @@ ndpi_protocol ndpi_detection_process_packet(struct ndpi_detection_module_struct
 #if 0
   /* See https://github.com/ntop/nDPI/pull/1425 */
     if((ret.master_protocol == NDPI_PROTOCOL_UNKNOWN) && (ret.app_protocol != NDPI_PROTOCOL_UNKNOWN) &&
-       (flow->guessed_host_protocol_id != NDPI_PROTOCOL_UNKNOWN)) {
+       (flow->guessed_protocol_id_by_ip != NDPI_PROTOCOL_UNKNOWN)) {
       ret.master_protocol = ret.app_protocol;
-      ret.app_protocol = flow->guessed_host_protocol_id;
+      ret.app_protocol = flow->guessed_protocol_id_by_ip;
     }
 #endif
 
@@ -7147,11 +7147,11 @@ static void ndpi_int_change_protocol(struct ndpi_detection_module_struct *ndpi_s
     lower_detected_protocol = NDPI_PROTOCOL_UNKNOWN;
 
   if((upper_detected_protocol != NDPI_PROTOCOL_UNKNOWN) && (lower_detected_protocol == NDPI_PROTOCOL_UNKNOWN)) {
-    if((flow->guessed_host_protocol_id != NDPI_PROTOCOL_UNKNOWN) &&
-       (upper_detected_protocol != flow->guessed_host_protocol_id)) {
+    if((flow->guessed_protocol_id_by_ip != NDPI_PROTOCOL_UNKNOWN) &&
+       (upper_detected_protocol != flow->guessed_protocol_id_by_ip)) {
       if(ndpi_str->proto_defaults[upper_detected_protocol].subprotocol_count > 0) {
 	lower_detected_protocol = upper_detected_protocol;
-	upper_detected_protocol = flow->guessed_host_protocol_id;
+	upper_detected_protocol = flow->guessed_protocol_id_by_ip;
       }
     }
   }