diff --git a/src/packet/tcp_helpers.h b/src/packet/tcp_helpers.h
index b238131..f8fa560 100644
--- a/src/packet/tcp_helpers.h
+++ b/src/packet/tcp_helpers.h
@@ -129,6 +129,16 @@ static inline const uint8_t *tcp_hdr_get_opt_ptr(const struct tcphdr *hdr)
     return ((const uint8_t *)hdr) + sizeof(struct tcphdr);
 }
 
+static inline void tcp_hdr_set_flags(struct tcphdr *hdr, uint8_t flags)
+{
+    hdr->th_flags = flags;
+}
+
+static inline void tcp_hdr_set_flag_rst(struct tcphdr *hdr)
+{
+    hdr->th_flags |= TH_RST;
+}
+
 #ifdef __cpluscplus
 }
 #endif
diff --git a/src/session/session_manager.cpp b/src/session/session_manager.cpp
index 98e8fb3..51eec9a 100644
--- a/src/session/session_manager.cpp
+++ b/src/session/session_manager.cpp
@@ -107,7 +107,10 @@ static void tcp_init_timeout_cb(struct session *sess, void *arg)
      struct session_manager *mgr = (struct session_manager *)arg;
      assert(mgr != NULL);
 
-     session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     if (session_get_closing_reasion(sess) == 0)
+     {
+          session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     }
      session_manager_update_tcp_to_closing(mgr, sess, 1);
 }
 
@@ -117,7 +120,10 @@ static void tcp_handshake_timeout_cb(struct session *sess, void *arg)
      struct session_manager *mgr = (struct session_manager *)arg;
      assert(mgr != NULL);
 
-     session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     if (session_get_closing_reasion(sess) == 0)
+     {
+          session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     }
      session_manager_update_tcp_to_closing(mgr, sess, 1);
 }
 
@@ -127,7 +133,10 @@ static void tcp_data_timeout_cb(struct session *sess, void *arg)
      struct session_manager *mgr = (struct session_manager *)arg;
      assert(mgr != NULL);
 
-     session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     if (session_get_closing_reasion(sess) == 0)
+     {
+          session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     }
      session_manager_update_tcp_to_closing(mgr, sess, 1);
 }
 
@@ -137,7 +146,10 @@ static void tcp_half_closed_timeout_cb(struct session *sess, void *arg)
      struct session_manager *mgr = (struct session_manager *)arg;
      assert(mgr != NULL);
 
-     session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     if (session_get_closing_reasion(sess) == 0)
+     {
+          session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     }
      session_manager_update_tcp_to_closing(mgr, sess, 1);
 }
 
@@ -156,7 +168,10 @@ static void udp_data_timeout_cb(struct session *sess, void *arg)
      struct session_manager *mgr = (struct session_manager *)arg;
      assert(mgr != NULL);
 
-     session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     if (session_get_closing_reasion(sess) == 0)
+     {
+          session_set_closing_reasion(sess, CLOSING_BY_TIMEOUT);
+     }
      session_manager_update_udp_to_closing(mgr, sess);
 }
 
@@ -734,7 +749,7 @@ static void session_manager_handle_tcp_on_opening(struct session_manager *mgr, s
 static void session_manager_handle_tcp_on_active(struct session_manager *mgr, struct session *sess, enum tcp_state tcp_old_state, enum tcp_state tcp_curr_state)
 {
      // active -> closing
-     if ((tcp_curr_state & TCP_C2S_FIN_RECVED) && (tcp_curr_state | TCP_S2C_FIN_RECVED))
+     if ((tcp_curr_state & TCP_C2S_FIN_RECVED) && (tcp_curr_state & TCP_S2C_FIN_RECVED))
      {
           SESSION_LOG_DEBUG("TCP FIN-FIN received, session %lu active -> closing", session_get_id(sess));
           session_manager_update_tcp_to_closing(mgr, sess, 1);
diff --git a/src/session/test/CMakeLists.txt b/src/session/test/CMakeLists.txt
index c86773e..8670376 100644
--- a/src/session/test/CMakeLists.txt
+++ b/src/session/test/CMakeLists.txt
@@ -23,6 +23,9 @@ target_link_libraries(gtest_tcp_init_to_opening session_manager gtest)
 add_executable(gtest_tcp_opening_to_active gtest_tcp_opening_to_active.cpp)
 target_link_libraries(gtest_tcp_opening_to_active session_manager gtest)
 
+add_executable(gtest_tcp_active_to_closing gtest_tcp_active_to_closing.cpp)
+target_link_libraries(gtest_tcp_active_to_closing session_manager gtest)
+
 include(GoogleTest)
 gtest_discover_tests(gtest_session)
 gtest_discover_tests(gtest_session_pool)
@@ -30,4 +33,5 @@ gtest_discover_tests(gtest_session_table)
 gtest_discover_tests(gtest_session_timer)
 gtest_discover_tests(gtest_session_queue)
 gtest_discover_tests(gtest_tcp_init_to_opening)
-gtest_discover_tests(gtest_tcp_opening_to_active)
\ No newline at end of file
+gtest_discover_tests(gtest_tcp_opening_to_active)
+gtest_discover_tests(gtest_tcp_active_to_closing)
\ No newline at end of file
diff --git a/src/session/test/gtest_tcp_active_to_closing.cpp b/src/session/test/gtest_tcp_active_to_closing.cpp
new file mode 100644
index 0000000..907a0fb
--- /dev/null
+++ b/src/session/test/gtest_tcp_active_to_closing.cpp
@@ -0,0 +1,443 @@
+// TCP state machine test: active -> closing
+
+#include "test_state_machine.h"
+
+static void build_active_tcp_session(struct session_manager *mgr, struct session *sess)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+
+    // SYN Packet
+    printf("=> packet parse: TCP C2S SYN packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt1_c2s_syn, sizeof(tcp_pkt1_c2s_syn));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_OPENING);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 0);
+    EXPECT_TRUE(session_get_create_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_tcp_state(sess) == TCP_SYN_RECVED);
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
+    EXPECT_TRUE(session_get0_1st_pkt(sess) == session_get0_c2s_1st_pkt(sess));
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+
+    sleep(1);
+    timestamp_update();
+
+    // C2S DATA Packet
+    printf("=> packet parse: TCP C2S DATA packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt4_c2s_http_req, sizeof(tcp_pkt4_c2s_http_req));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_ACTIVE);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 0);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_C2S_DATA_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+
+    sleep(1);
+    timestamp_update();
+}
+
+/******************************************************************************
+ * case: TCP active -> closing (by FIN-FIN)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_FIN_FIN)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    // C2S FIN Packet
+    printf("=> packet parse: TCP C2S FIN packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt9_c2s_fin, sizeof(tcp_pkt9_c2s_fin));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_ACTIVE);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_CLIENT_FIN);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145 + 66);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 0);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_C2S_FIN_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+
+    sleep(1);
+    timestamp_update();
+
+    // S2C FIN Packet
+    printf("=> packet parse: TCP S2C FIN packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt10_s2c_fin, sizeof(tcp_pkt10_s2c_fin));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_CLOSING);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_CLIENT_FIN);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145 + 66);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 66);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 1);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_S2C);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_S2C_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_C2S_FIN_RECVED | TCP_S2C_FIN_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) != NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 0, 1, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_CLIENT_FIN);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+/******************************************************************************
+ * case: TCP active -> closing (by C2S RST)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_C2S_RST)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    // C2S RST Packet
+    printf("=> packet parse: TCP C2S RST packet\n");
+    char tcp_pkt_c2s_rst[1500] = {0};
+    memcpy(tcp_pkt_c2s_rst, tcp_pkt9_c2s_fin, sizeof(tcp_pkt9_c2s_fin));
+    packet_parse(&pkt, (const char *)tcp_pkt_c2s_rst, sizeof(tcp_pkt9_c2s_fin));
+    const struct layer_record *tcp_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_TCP);
+    EXPECT_TRUE(tcp_layer);
+    struct tcphdr *hdr = (struct tcphdr *)tcp_layer->hdr_ptr;
+    tcp_hdr_set_flags(hdr, 0);
+    tcp_hdr_set_flag_rst(hdr);
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_CLOSING);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_CLIENT_RST);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145 + 66);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 0);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_C2S_RST_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 0, 1, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_CLIENT_RST);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+/******************************************************************************
+ * case: TCP active -> closing (by S2C RST)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_S2C_RST)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    // S2C RST Packet
+    printf("=> packet parse: TCP S2C RST packet\n");
+    char tcp_pkt_s2c_rst[1500] = {0};
+    memcpy(tcp_pkt_s2c_rst, tcp_pkt10_s2c_fin, sizeof(tcp_pkt10_s2c_fin));
+    packet_parse(&pkt, (const char *)tcp_pkt_s2c_rst, sizeof(tcp_pkt10_s2c_fin));
+    const struct layer_record *tcp_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_TCP);
+    EXPECT_TRUE(tcp_layer);
+    struct tcphdr *hdr = (struct tcphdr *)tcp_layer->hdr_ptr;
+    tcp_hdr_set_flags(hdr, 0);
+    tcp_hdr_set_flag_rst(hdr);
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_CLOSING);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_SERVER_RST);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 66);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 1);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_S2C);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_S2C_RST_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) != NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 0, 1, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_SERVER_RST);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+/******************************************************************************
+ * case: TCP active -> closing (by date timeout)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_DATA_TIMEOUT)
+{
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+/******************************************************************************
+ * case: TCP active -> closing (by C2S half closed timeout)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_C2S_HALF_CLOSED_TIMEOUT)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    // C2S FIN Packet
+    printf("=> packet parse: TCP C2S FIN packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt9_c2s_fin, sizeof(tcp_pkt9_c2s_fin));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_ACTIVE);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_CLIENT_FIN);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145 + 66);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 0);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 0);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_C2S_FIN_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_CLIENT_FIN);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+/******************************************************************************
+ * case: TCP active -> closing (by S2C half closed timeout)
+ ******************************************************************************/
+
+#if 1
+TEST(TCP_ACTIVE_TO_CLOSING, BY_S2C_HALF_CLOSED_TIMEOUT)
+{
+    char buffer[1024] = {0};
+    struct packet pkt;
+    struct session *sess = NULL;
+    struct session_manager *mgr = NULL;
+
+    timestamp_update();
+
+    mgr = session_manager_create(&config);
+    EXPECT_TRUE(mgr != NULL);
+
+    // SYN Packet & C2S DATA Packet
+    build_active_tcp_session(mgr, sess);
+
+    // S2C FIN Packet
+    printf("=> packet parse: TCP S2C FIN packet\n");
+    packet_parse(&pkt, (const char *)tcp_pkt10_s2c_fin, sizeof(tcp_pkt10_s2c_fin));
+    printf("<= packet parse\n\n");
+    sess = session_manager_update_session(mgr, &pkt);
+    EXPECT_TRUE(sess);
+
+    EXPECT_TRUE(session_get_id(sess) == 0);
+    tuple6_tostring(session_get0_key(sess), buffer, sizeof(buffer));
+    EXPECT_STREQ(buffer, "192.168.38.105:60111 -> 93.184.216.34:80, proto: 6, domain: 0");
+    EXPECT_TRUE(session_get_key_dir(sess) == SESSION_DIR_C2S);
+    EXPECT_TRUE(session_get_state(sess) == SESSION_STATE_ACTIVE);
+    EXPECT_TRUE(session_get_type(sess) == SESSION_TYPE_TCP);
+    EXPECT_TRUE(session_get_dup_traffic_flag(sess) == 0);
+    EXPECT_TRUE(session_get_closing_reasion(sess) == CLOSING_BY_SERVER_FIN);
+    EXPECT_TRUE(session_get_c2s_bytes(sess) == 78 + 145);
+    EXPECT_TRUE(session_get_s2c_bytes(sess) == 66);
+    EXPECT_TRUE(session_get_c2s_packets(sess) == 1 + 1);
+    EXPECT_TRUE(session_get_s2c_packets(sess) == 1);
+    EXPECT_TRUE(session_get_create_time(sess) < timestamp_get_msec());
+    EXPECT_TRUE(session_get_last_time(sess) == timestamp_get_msec());
+    EXPECT_TRUE(session_get0_cur_pkt(sess) == &pkt);
+    EXPECT_TRUE(session_get_cur_dir(sess) == SESSION_DIR_S2C);
+    EXPECT_TRUE(session_get_tcp_state(sess) == (TCP_SYN_RECVED | TCP_C2S_ACK_RECVED | TCP_S2C_ACK_RECVED | TCP_C2S_DATA_RECVED | TCP_S2C_FIN_RECVED));
+    EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
+    EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) != NULL);
+
+    __session_dispatch(sess);
+
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_SERVER_FIN);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
+
+    session_manager_destroy(mgr);
+}
+#endif
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
diff --git a/src/session/test/gtest_tcp_init_to_opening.cpp b/src/session/test/gtest_tcp_init_to_opening.cpp
index 6c8faea..a88f10a 100644
--- a/src/session/test/gtest_tcp_init_to_opening.cpp
+++ b/src/session/test/gtest_tcp_init_to_opening.cpp
@@ -1,58 +1,6 @@
 // TCP state machine test: init -> opening
 
-#include <gtest/gtest.h>
-
-#include "session_private.h"
-#include "timestamp.h"
-#include "session_manager.h"
-#include "ipv4_helpers.h"
-#include "test_packets.h"
-
-struct session_manager_config config = {
-    // max session number
-    .max_tcp_session_num = 3,
-    .max_udp_session_num = 3,
-
-    // tcp timeout
-    .tcp_timeout_init = 2,
-    .tcp_timeout_handshake = 2,
-    .tcp_timeout_data = 2,
-    .tcp_timeout_half_closed = 2,
-    .tcp_timeout_time_wait = 2,
-    .tcp_timeout_discard = 2,
-
-    // udp timeout
-    .udp_timeout_data = 1,
-
-    // tcp duplicate packet filter
-    .tcp_dupkt_filter_enable = 1,
-    .tcp_dupkt_filter_capacity = 1000,
-    .tcp_dupkt_filter_timeout = 10,
-    .tcp_dupkt_filter_error_rate = 0.0001,
-
-    // udp eviction filter
-    .udp_eviction_filter_enable = 1,
-    .udp_eviction_filter_capacity = 1000,
-    .udp_eviction_filter_timeout = 10,
-    .udp_eviction_filter_error_rate = 0.0001,
-};
-
-static void __session_dispatch(struct session *sess)
-{
-    if (sess == NULL)
-    {
-        return;
-    }
-
-    printf("\n");
-    printf("=> session dispatch: %p\n", sess);
-    session_dump(sess);
-    printf("<= session dispatch\n");
-    printf("\n");
-
-    session_set0_cur_pkt(sess, NULL);
-    session_set_cur_dir(sess, SESSION_DIR_NONE);
-}
+#include "test_state_machine.h"
 
 /******************************************************************************
  * case: TCP init -> opening (by SYN)
@@ -101,27 +49,9 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -174,27 +104,9 @@ TEST(TCP_INIT_TO_OPENING, BY_SYNACK)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -247,12 +159,7 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_SYNACK)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -287,27 +194,9 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_SYNACK)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -360,12 +249,7 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_SYNACK_ACK)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -400,12 +284,7 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_SYNACK_ACK)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -437,27 +316,11 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_SYNACK_ACK)
     EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
     EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) != NULL);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_dispatch(sess);
 
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -512,19 +375,16 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_RETRANSMISSION)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
 
     // SYN Packet retransmission
     printf("=> packet parse: TCP C2S SYN retransmission packet\n");
-    packet_parse(&pkt, (const char *)tcp_pkt1_c2s_syn, sizeof(tcp_pkt1_c2s_syn));
+    char tcp_pkt_c2s_syn_retransmission[1500] = {0};
+    memcpy(tcp_pkt_c2s_syn_retransmission, tcp_pkt1_c2s_syn, sizeof(tcp_pkt1_c2s_syn));
+    packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
     const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
@@ -556,27 +416,9 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_RETRANSMISSION)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -631,19 +473,16 @@ TEST(TCP_INIT_TO_OPENING, BY_SYNACK_RETRANSMISSION)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
 
     // SYNACK Packet retransmission
     printf("=> packet parse: TCP S2C SYNACK retransmission packet\n");
-    packet_parse(&pkt, (const char *)tcp_pkt2_s2c_syn_ack, sizeof(tcp_pkt2_s2c_syn_ack));
+    char tcp_pkt_s2c_synack_retransmission[1500] = {0};
+    memcpy(tcp_pkt_s2c_synack_retransmission, tcp_pkt2_s2c_syn_ack, sizeof(tcp_pkt2_s2c_syn_ack));
+    packet_parse(&pkt, (const char *)tcp_pkt_s2c_synack_retransmission, sizeof(tcp_pkt2_s2c_syn_ack));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
     const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
@@ -675,27 +514,9 @@ TEST(TCP_INIT_TO_OPENING, BY_SYNACK_RETRANSMISSION)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -748,12 +569,7 @@ TEST(TCP_INIT_TO_OPENING, BY_C2S_ASMMETRIC)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -786,27 +602,11 @@ TEST(TCP_INIT_TO_OPENING, BY_C2S_ASMMETRIC)
     EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
     EXPECT_TRUE(session_get0_1st_pkt(sess) == session_get0_c2s_1st_pkt(sess));
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_dispatch(sess);
 
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -859,12 +659,7 @@ TEST(TCP_INIT_TO_OPENING, BY_S2C_ASMMETRIC)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -899,27 +694,9 @@ TEST(TCP_INIT_TO_OPENING, BY_S2C_ASMMETRIC)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
diff --git a/src/session/test/gtest_tcp_opening_to_active.cpp b/src/session/test/gtest_tcp_opening_to_active.cpp
index 1e3e068..c2e6643 100644
--- a/src/session/test/gtest_tcp_opening_to_active.cpp
+++ b/src/session/test/gtest_tcp_opening_to_active.cpp
@@ -1,58 +1,6 @@
 // TCP state machine test: opening -> active
 
-#include <gtest/gtest.h>
-
-#include "session_private.h"
-#include "timestamp.h"
-#include "session_manager.h"
-#include "ipv4_helpers.h"
-#include "test_packets.h"
-
-struct session_manager_config config = {
-    // max session number
-    .max_tcp_session_num = 3,
-    .max_udp_session_num = 3,
-
-    // tcp timeout
-    .tcp_timeout_init = 2,
-    .tcp_timeout_handshake = 2,
-    .tcp_timeout_data = 2,
-    .tcp_timeout_half_closed = 2,
-    .tcp_timeout_time_wait = 2,
-    .tcp_timeout_discard = 2,
-
-    // udp timeout
-    .udp_timeout_data = 1,
-
-    // tcp duplicate packet filter
-    .tcp_dupkt_filter_enable = 1,
-    .tcp_dupkt_filter_capacity = 1000,
-    .tcp_dupkt_filter_timeout = 10,
-    .tcp_dupkt_filter_error_rate = 0.0001,
-
-    // udp eviction filter
-    .udp_eviction_filter_enable = 1,
-    .udp_eviction_filter_capacity = 1000,
-    .udp_eviction_filter_timeout = 10,
-    .udp_eviction_filter_error_rate = 0.0001,
-};
-
-static void __session_dispatch(struct session *sess)
-{
-    if (sess == NULL)
-    {
-        return;
-    }
-
-    printf("\n");
-    printf("=> session dispatch: %p\n", sess);
-    session_dump(sess);
-    printf("<= session dispatch\n");
-    printf("\n");
-
-    session_set0_cur_pkt(sess, NULL);
-    session_set_cur_dir(sess, SESSION_DIR_NONE);
-}
+#include "test_state_machine.h"
 
 /******************************************************************************
  * case: TCP opening -> active (by C2S DATA)
@@ -101,12 +49,7 @@ TEST(TCP_OPENING_TO_ACTIVE, BY_SYN_C2S_DATA)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -138,27 +81,11 @@ TEST(TCP_OPENING_TO_ACTIVE, BY_SYN_C2S_DATA)
     EXPECT_TRUE(session_get0_c2s_1st_pkt(sess) != NULL);
     EXPECT_TRUE(session_get0_s2c_1st_pkt(sess) == NULL);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_dispatch(sess);
 
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
@@ -211,12 +138,7 @@ TEST(TCP_OPENING_TO_ACTIVE, BY_SYNACK_S2C_DATA)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 1, 0, 0, 0, 0, 0);
 
     sleep(1);
     timestamp_update();
@@ -250,27 +172,9 @@ TEST(TCP_OPENING_TO_ACTIVE, BY_SYNACK_S2C_DATA)
 
     __session_dispatch(sess);
 
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 1);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
-
-    for (int i = 0; i < 3; i++)
-    {
-        timestamp_update();
-        __session_dispatch(session_manager_get_expired_session(mgr));
-        __session_dispatch(session_manager_get_evicted_session(mgr));
-        sleep(1);
-    }
-
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == 0);
-    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == 0);
+    __session_manager_count(mgr, 0, 1, 0, 0, 0, 0);
+    __session_manager_dispatch(mgr, CLOSING_BY_TIMEOUT);
+    __session_manager_count(mgr, 0, 0, 0, 0, 0, 0);
 
     session_manager_destroy(mgr);
 }
diff --git a/src/session/test/test_state_machine.h b/src/session/test/test_state_machine.h
new file mode 100644
index 0000000..591a9db
--- /dev/null
+++ b/src/session/test/test_state_machine.h
@@ -0,0 +1,101 @@
+#ifndef _TEST_STATE_MACHINE_H
+#define _TEST_STATE_MACHINE_H
+
+#ifdef __cpluscplus
+extern "C"
+{
+#endif
+
+#include <gtest/gtest.h>
+
+#include "session_private.h"
+#include "timestamp.h"
+#include "session_manager.h"
+#include "ipv4_helpers.h"
+#include "tcp_helpers.h"
+#include "test_packets.h"
+
+struct session_manager_config config = {
+    // max session number
+    .max_tcp_session_num = 3,
+    .max_udp_session_num = 3,
+
+    // tcp timeout
+    .tcp_timeout_init = 2,
+    .tcp_timeout_handshake = 2,
+    .tcp_timeout_data = 2,
+    .tcp_timeout_half_closed = 2,
+    .tcp_timeout_time_wait = 2,
+    .tcp_timeout_discard = 2,
+
+    // udp timeout
+    .udp_timeout_data = 1,
+
+    // tcp duplicate packet filter
+    .tcp_dupkt_filter_enable = 1,
+    .tcp_dupkt_filter_capacity = 1000,
+    .tcp_dupkt_filter_timeout = 10,
+    .tcp_dupkt_filter_error_rate = 0.0001,
+
+    // udp eviction filter
+    .udp_eviction_filter_enable = 1,
+    .udp_eviction_filter_capacity = 1000,
+    .udp_eviction_filter_timeout = 10,
+    .udp_eviction_filter_error_rate = 0.0001,
+};
+
+static void __session_dispatch(struct session *sess)
+{
+    if (sess == NULL)
+    {
+        return;
+    }
+
+    printf("\n");
+    printf("=> session dispatch: %p\n", sess);
+    session_dump(sess);
+    printf("<= session dispatch\n");
+    printf("\n");
+
+    session_set0_cur_pkt(sess, NULL);
+    session_set_cur_dir(sess, SESSION_DIR_NONE);
+}
+
+static void __session_manager_dispatch(struct session_manager *mgr, enum closing_reasion reason)
+{
+    struct session *sess;
+    for (int i = 0; i < 3; i++)
+    {
+        timestamp_update();
+        sess = session_manager_get_expired_session(mgr);
+        __session_dispatch(sess);
+        if (sess && session_get_state(sess) == SESSION_STATE_CLOSING)
+        {
+            EXPECT_TRUE(session_get_closing_reasion(sess) == reason);
+        }
+        sess = session_manager_get_evicted_session(mgr);
+        __session_dispatch(sess);
+        if (sess && session_get_state(sess) == SESSION_STATE_CLOSING)
+        {
+            EXPECT_TRUE(session_get_closing_reasion(sess) == reason);
+        }
+        sleep(1);
+    }
+}
+
+static void __session_manager_count(struct session_manager *mgr, uint64_t tcp_opening_num, uint64_t tcp_active_num, uint64_t tcp_closing_num, uint64_t udp_opening_num, uint64_t udp_active_num, uint64_t udp_closing_num)
+{
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_OPENING) == tcp_opening_num);
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_ACTIVE) == tcp_active_num);
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_TCP, SESSION_STATE_CLOSING) == tcp_closing_num);
+
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_OPENING) == udp_opening_num);
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_ACTIVE) == udp_active_num);
+    EXPECT_TRUE(session_manager_get_session_number(mgr, SESSION_TYPE_UDP, SESSION_STATE_CLOSING) == udp_closing_num);
+}
+
+#ifdef __cpluscplus
+}
+#endif
+
+#endif