diff --git a/include/stellar/packet.h b/include/stellar/packet.h
index d3132df..bf3c54a 100644
--- a/include/stellar/packet.h
+++ b/include/stellar/packet.h
@@ -47,10 +47,6 @@ struct packet *packet_build_tcp(const struct packet *origin_pkt, uint32_t tcp_se
 struct packet *packet_build_udp(const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len);
 struct packet *packet_build_l3(const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
 
-struct tcp_segment;
-const char *tcp_segment_get_data(const struct tcp_segment *seg);
-uint16_t tcp_segment_get_len(const struct tcp_segment *seg);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/stellar/stellar.h b/include/stellar/stellar.h
index ed204dc..efd542f 100644
--- a/include/stellar/stellar.h
+++ b/include/stellar/stellar.h
@@ -32,10 +32,14 @@ int stellar_session_plugin_register(struct stellar *st,
 
 void stellar_session_plugin_dettach_current_session(struct session *sess);
 
+// TOPIC_TCP_STREAM return msg need convert to (const struct tcp_segment *)
+struct tcp_segment;
+const char *tcp_segment_get_data(const struct tcp_segment *seg);
+uint16_t tcp_segment_get_len(const struct tcp_segment *seg);
 
-
+// TOPIC_UDP or TOPIC_TCP return msg need convert to (const struct packet *)
 struct packet;
-typedef void plugin_on_packet_func(struct packet *pkt,  unsigned char ip_protocol, void *plugin_env);
+typedef void plugin_on_packet_func(struct packet *pkt, unsigned char ip_protocol, void *plugin_env);
 
 //return packet plugin_id
 int stellar_packet_plugin_register(struct stellar *st, unsigned char ip_protocol, plugin_on_packet_func on_packet, void *plugin_env);