2 files changed, 32 insertions, 25 deletions
diff --git a/src/include/ndpi_typedefs.h b/src/include/ndpi_typedefs.h
index ffc98ecd1..a2e10878f 100644
--- a/src/include/ndpi_typedefs.h
+++ b/src/include/ndpi_typedefs.h
@@ -835,9 +835,6 @@ struct ndpi_flow_tcp_struct {
   /* NDPI_PROTOCOL_SSH */
   u_int32_t ssh_stage:3;
 
-  /* NDPI_PROTOCOL_KAFKA */
-  u_int32_t kafka_stage:1;
-
   /* NDPI_PROTOCOL_VNC */
   u_int32_t vnc_stage:2;			// 0 - 3
 
@@ -891,9 +888,6 @@ struct ndpi_flow_tcp_struct {
 
   /* NDPI_PROTOCOL_RADMIN */
   u_int32_t radmin_stage:1;
-
-  /* NDPI_PROTOCOL_KAFKA */
-  u_int32_t kafka_correlation_id;
 };
 
 /* ************************************************** */
diff --git a/src/lib/protocols/kafka.c b/src/lib/protocols/kafka.c
index cffd1f32f..abf0ae3ca 100644
--- a/src/lib/protocols/kafka.c
+++ b/src/lib/protocols/kafka.c
@@ -29,6 +29,14 @@
 #include "ndpi_api.h"
 #include "ndpi_private.h"
 
+static void ndpi_int_kafka_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
+                                          struct ndpi_flow_struct *flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found Apache Kafka\n");
+  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_APACHE_KAFKA,
+                             NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+}
+
 static void ndpi_search_kafka(struct ndpi_detection_module_struct *ndpi_struct,
                               struct ndpi_flow_struct *flow)
 {
@@ -41,32 +49,37 @@ static void ndpi_search_kafka(struct ndpi_detection_module_struct *ndpi_struct,
    * API keys: https://kafka.apache.org/protocol.html#protocol_api_keys
    * API versions: https://cwiki.apache.org/confluence/display/KAFKA/Kafka+APIs
    */
-  if (packet->payload_packet_len > 40 &&
-      ntohl(get_u_int32_t(packet->payload, 0)) == (u_int32_t)(packet->payload_packet_len-4))
+  if (packet->payload_packet_len < 8 /* min. required packet length */ ||
+      ntohl(get_u_int32_t(packet->payload, 0)) != (uint32_t)(packet->payload_packet_len - 4))
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  /* Request */
+  if (ntohs(get_u_int16_t(packet->payload, 4)) < 75 && /* API key */
+      ntohs(get_u_int16_t(packet->payload, 6)) < 16    /* API version */)
   {
-    /* Request */
-    if (!flow->l4.tcp.kafka_stage &&
-        current_pkt_from_client_to_server(ndpi_struct, flow) &&
-        ntohs(get_u_int16_t(packet->payload, 4)) < 75 && /* API key */
-        ntohs(get_u_int16_t(packet->payload, 6)) < 16    /* API version */)
+    if (packet->payload_packet_len < 14)
     {
-      flow->l4.tcp.kafka_correlation_id = ntohl(get_u_int16_t(packet->payload, 8));
-      flow->l4.tcp.kafka_stage = 1;
-      return;
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
     }
 
-    /* Response */
-    if (flow->l4.tcp.kafka_stage == 1 && 
-        current_pkt_from_server_to_client(ndpi_struct, flow))
+    const uint16_t client_id_len = ntohs(get_u_int16_t(packet->payload, 12));
+    if (client_id_len + 12 + 2 > packet->payload_packet_len)
     {
-      if (ntohl(get_u_int16_t(packet->payload, 4)) == flow->l4.tcp.kafka_correlation_id)
-      {
-        NDPI_LOG_INFO(ndpi_struct, "found Apache Kafka\n");
-        ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_APACHE_KAFKA,
-                                   NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
         return;
-      }
     }
+    if (ndpi_is_printable_buffer(&packet->payload[14], client_id_len) == 0)
+    {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return;
+    }
+
+    ndpi_int_kafka_add_connection(ndpi_struct, flow);
+    return;
   }
 
   NDPI_EXCLUDE_PROTO(ndpi_struct, flow);