[PACKET_IO]format api style

25 files changed, 1167 insertions, 688 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f11277d..2549c33 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,10 @@ add_definitions(-D_GNU_SOURCE)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_C_STANDARD 11)
 
+SET(CMAKE_BUILD_TYPE "Debug")
+SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
+SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")
+
 if(NOT CMAKE_BUILD_TYPE)
 	set(CMAKE_BUILD_TYPE RelWithDebInfo)
 endif()
diff --git a/sdk/include/packet.h b/sdk/include/packet.h
index 8ffe7c2..3b64d74 100644
--- a/sdk/include/packet.h
+++ b/sdk/include/packet.h
@@ -1,3 +1,16 @@
 #pragma once
 
-struct stellar_packet;
\ No newline at end of file
+#include <stddef.h>
+
+struct stellar_packet;
+
+/**
+ * @brief get stellar_packet's ctrlzone 
+ * @note ctrlzone's memory is 64 bytes, do not exceed it
+ */
+char *get_stellar_packet_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len);
+
+/**
+ * @brief get stellar_packet's data pointer
+ */
+char *get_stellar_packet_data(struct stellar_packet *p, size_t *data_len);
\ No newline at end of file
diff --git a/sdk/include/util_errors.h b/sdk/include/util_errors.h
index 1426a06..53997fa 100644
--- a/sdk/include/util_errors.h
+++ b/sdk/include/util_errors.h
@@ -39,6 +39,7 @@ typedef enum {
     ST_ERR_PCAP_SET_PROMISC,
     ST_ERR_PCAP_SET_TIMEOUT,
     ST_ERR_PCAP_ACTIVATE_HANDLE,
+    ST_ERR_PIO_CONFIG,
     ST_ERR_FOPEN,
     ST_ERR_BPF,
     ST_ERR_MAX
diff --git a/src/app.toml b/src/app.toml
index 83a8f4b..83a1eb4 100644
--- a/src/app.toml
+++ b/src/app.toml
@@ -1,19 +1,24 @@
-[THREAD]
-
-thread_num = 1
-
 [PACKET_IO]
-"""
-example1:
-run_mode = pcap_live
-interface = [eth0, eth1]
+# example1:
+# RUN_MODE="PCAP_LIVE_MODE"
+# WORKER_THREAD_NUM=10                   # Prompt marsio how many threads to start to receive packets
+# INTERFACE=["eth0", "eth1"]
+# SNAP_LEN=65535                         # default 65535
+# PROMISC=1                              # 0(disable) 1(enable), if enable nic promisc mode, default 0(disable)
+# BPF_FILTER="port 80 and udp"           # default null
+
+# example2:
+# RUN_MODE="MARSIO_MODE"
+# WORKER_THREAD_NUM=10                   # Prompt marsio how many threads to start to receive packets
+# INTERFACE=["eth0", "eth1"]
 
-example2:
-run_mode = marsio
-work_thread_num = 10  # Prompt marsio how many threads to start to receive packets
-interface = [eth0]
+# example3:
+# RUN_MODE="PCAP_FILE_MODE"
+# WORKER_THREAD_NUM=10                    # Prompt marsio how many threads to start to receive packets
+# PCAP_FILE_PATH="/tmp/pcapfile/001.pcap" # if single file, specify dir+filename; if pcapfile directory, specify dir
+# DELETE_WHEN_DONE=0                      # 0(false) 1(true), default 0, if delete it when the pcapfile is processed
+# BPF_FILTER="port 80 and udp"            # default null
 
-example3:
-run_mode = pcap_file
-pcap_file_path = /tmp/pcapfile/001.pcap # if single file, specify dir+filename; if pcapfile directory, specify dir
-"""
\ No newline at end of file
+RUN_MODE="PCAP_LIVE_MODE"
+WORKER_THREAD_NUM=3                      # Prompt marsio how many threads to start to receive packets
+INTERFACE=["eth0"]
\ No newline at end of file
diff --git a/src/common/global_var.cpp b/src/common/global_var.cpp
deleted file mode 100644
index 4a63b76..0000000
--- a/src/common/global_var.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
-**********************************************************************************************
-*	File: global_var.cpp
-*   Description:
-*	Authors: Liu WenTan <[email protected]>
-*	Date:    2022-07-15
-*   Copyright: (c) 2018-2022 Geedge Networks, Inc. All rights reserved.
-***********************************************************************************************
-*/
-
-#include "global_var.h"
-
-struct stellar_engine g_engine_instance;
\ No newline at end of file
diff --git a/src/common/global_var.h b/src/common/global_var.h
deleted file mode 100644
index 5484363..0000000
--- a/src/common/global_var.h
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
-**********************************************************************************************
-*	File: global_var.h
-*   Description: global variable and data structure
-*	Authors: Liu WenTan <[email protected]>
-*	Date:    2022-07-15
-*   Copyright: (c) 2018-2022 Geedge Networks, Inc. All rights reserved.
-***********************************************************************************************
-*/
-
-#ifndef _GLOBAL_VAR_H_
-#define _GLOBAL_VAR_H_
-
-#ifdef __cpluscplus
-extern "C"
-{
-#endif
-
-#include <limits.h>
-#include <stdint.h>
-#include <time.h>
-
-#define DEV_MAX_CNT 64
-#define STR_MAX_LEN 1024
-
-enum packet_io_run_mode {
-	PACKET_IO_RUN_MODE_PCAP_FILE,
-	PACKET_IO_RUN_MODE_PCAP_LIVE,
-	PACKET_IO_RUN_MODE_MARSIO,
-	PACKET_IO_RUN_MODE_MAX,
-};
-
-struct cpu_config {};
-struct mem_config {};
-
-struct system_config {
-    char instance_name[NAME_MAX];
-};
-
-/* store packet_io config */
-struct packet_io_config {
-	/* packet_io run mode */
-	enum packet_io_run_mode mode;
-
-    /* worker thread num */
-    uint32_t thread_num;
-
-	/* device name list */
-	char dev_name[DEV_MAX_CNT][NAME_MAX];
-
-	/* device counts */
-	uint32_t dev_cnt;
-
-    /* bpf filter string, such as "tcp and port 25"*/
-    char bpf_string[STR_MAX_LEN];
-
-    /* delete after the pcap file is read */
-    bool should_delete;
-
-    time_t delay;
-
-    /* snapshot length */
-    int snaplen;
-
-    /* promiscuous value */
-    int promisc;
-
-    /* marsio ctrlzone id */
-    int mr_ctrlzone_id;
-};
-
-struct lib_config {
-    const char *libmarsio_path;
-};
-
-struct stellar_config {
-    struct cpu_config cpu;
-    struct mem_config mem;
-    struct system_config system;
-    struct packet_io_config packet_io;
-    struct lib_config lib;
-};
-
-struct stellar_engine {
-    struct stellar_config config;
-};
-
-extern struct stellar_engine g_engine_instance;
-
-#ifdef __cpluscplus
-}
-#endif
-
-#endif /* _GLOBAL_VAR_H_ */
\ No newline at end of file
diff --git a/src/common/time_helper.cpp b/src/common/time_helper.cpp
index 2545ba7..2eb2399 100644
--- a/src/common/time_helper.cpp
+++ b/src/common/time_helper.cpp
@@ -21,7 +21,7 @@ void get_current_timespec(struct timespec *tm)
     }
 }
 
-int compare_timespec(struct timespec *left, struct timespec *right)
+ssize_t compare_timespec(struct timespec *left, struct timespec *right)
 {
     if (left->tv_sec < right->tv_sec) {
         return -1;
diff --git a/src/common/time_helper.h b/src/common/time_helper.h
index 55e7e60..fd1073a 100644
--- a/src/common/time_helper.h
+++ b/src/common/time_helper.h
@@ -18,10 +18,11 @@ extern "C"
 
 #include <time.h>
 #include <stdint.h>
+#include <sys/types.h>
 
 void get_current_timespec(struct timespec *tm);
 
-int compare_timespec(struct timespec *left, struct timespec *right);
+ssize_t compare_timespec(struct timespec *left, struct timespec *right);
 
 void copy_timespec(struct timespec *from, struct timespec *to);
 
diff --git a/src/main.cpp b/src/main.cpp
index 4b56e52..615e046 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -7,6 +7,8 @@
 ***********************************************************************************************
 */
 
+#include <limits.h>
+#include <stdio.h>
 #include <pthread.h>
 #include <unistd.h>
 #include <netinet/ether.h>
@@ -15,13 +17,13 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
-#include "global_var.h"
 #include "logger.h"
 #include "packet_io.h"
 #include "packet_io_util.h"
 #include "session_manager.h"
 #include "plugin_manager.h"
 #include "http.h"
+#include "utils.h"
 #include "util_errors.h"
 
 struct worker_thread_ctx
@@ -59,6 +61,7 @@ void *worker_thread_cycle(void *arg)
 			// dispatch to trigger polling event
 		}
 #endif
+		}
 	}
 	return nullptr;
 }
diff --git a/src/packet_io/CMakeLists.txt b/src/packet_io/CMakeLists.txt
index d84f4ac..bc0f786 100644
--- a/src/packet_io/CMakeLists.txt
+++ b/src/packet_io/CMakeLists.txt
@@ -1,9 +1,8 @@
 
 add_library(packet_io
-	../common/global_var.cpp
 	../common/time_helper.cpp
-	packet_io.cpp
 	packet_io_util.cpp
+	packet_io_internal.cpp
 	pcap_live_mode/pio_pcap_live.cpp
 	pcap_file_mode/pio_pcap_file.cpp
 	marsio_mode/pio_marsio.cpp
diff --git a/src/packet_io/marsio_mode/pio_marsio.cpp b/src/packet_io/marsio_mode/pio_marsio.cpp
index 8a95266..a867ab2 100644
--- a/src/packet_io/marsio_mode/pio_marsio.cpp
+++ b/src/packet_io/marsio_mode/pio_marsio.cpp
@@ -11,12 +11,12 @@
 #include <dlfcn.h>
 #include <string.h>
 
-#include "global_var.h"
 #include "logger.h"
 #include "utils.h"
 #include "util_errors.h"
 #include "pio_marsio.h"
 #include "packet_io.h"
+#include "packet_io_internal.h"
 
 #define MARSIO_BURST_PKT_MAX (256)
 
@@ -28,14 +28,14 @@ static void fake_marsio_buff_set_rehash_index(marsio_buff_t *m, uint32_t hash)
 	return;
 }
 
-static int pio_get_marsio_dll_function_entries(void) 
+static ssize_t pio_get_marsio_dll_function_entries(void) 
 {
 	
-    void *marsio_so_handle = dlopen(g_engine_instance.config.lib.libmarsio_path, 
+    void *marsio_so_handle = dlopen(g_packet_io_config.marsio.libmarsio_path, 
 									RTLD_NOW | RTLD_LOCAL | RTLD_NODELETE);
     if (nullptr == marsio_so_handle) {
         printf("\033[1;31;40m[Error]dlopen '%s' failed, %s\033[0m\n", 
-				g_engine_instance.config.lib.libmarsio_path, dlerror());
+				g_packet_io_config.marsio.libmarsio_path, dlerror());
 		return -1;
     }
 	
@@ -43,7 +43,7 @@ static int pio_get_marsio_dll_function_entries(void)
 		(struct mr_instance *(*)(void))dlsym(marsio_so_handle, "marsio_create");
     if (nullptr == g_marsio_dll_func.marsio_create) {
         printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_create", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
     }
 
@@ -51,7 +51,7 @@ static int pio_get_marsio_dll_function_entries(void)
 		(int (*)(struct mr_instance *, const char *))dlsym(marsio_so_handle, "marsio_init");
 	if (nullptr == g_marsio_dll_func.marsio_init) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_init", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -59,7 +59,7 @@ static int pio_get_marsio_dll_function_entries(void)
 		(int (*)(struct mr_instance *))dlsym(marsio_so_handle, "marsio_destory");
 	if (nullptr == g_marsio_dll_func.marsio_destroy) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_destory", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -68,7 +68,7 @@ static int pio_get_marsio_dll_function_entries(void)
 							 unsigned int, unsigned int))dlsym(marsio_so_handle, "marsio_open_device");
 	if (nullptr == g_marsio_dll_func.marsio_open_device) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_open_device", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -76,7 +76,7 @@ static int pio_get_marsio_dll_function_entries(void)
 		(void (*)(struct mr_vdev *))dlsym(marsio_so_handle, "marsio_close_device");
 	if (nullptr ==g_marsio_dll_func.marsio_close_device) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_close_device", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -84,7 +84,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (int (*)(struct mr_instance *, marsio_opt_type_t, void *, size_t))dlsym(marsio_so_handle, "marsio_option_set");
     if (nullptr == g_marsio_dll_func.marsio_option_set) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_option_set", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -92,7 +92,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (struct mr_sendpath *(*)(struct mr_vdev *))dlsym(marsio_so_handle, "marsio_sendpath_create_by_vdev");
 	if (nullptr == g_marsio_dll_func.marsio_sendpath_create_by_vdev) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_sendpath_create_by_vdev", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -100,14 +100,14 @@ static int pio_get_marsio_dll_function_entries(void)
         (void (*)(struct mr_sendpath *))dlsym(marsio_so_handle, "marsio_sendpath_destory");
 	if (nullptr == g_marsio_dll_func.marsio_sendpath_destroy) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_sendpath_destory", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 	
 	g_marsio_dll_func.marsio_thread_init = (int (*)(struct mr_instance *))dlsym(marsio_so_handle, "marsio_thread_init");
 	if (nullptr == g_marsio_dll_func.marsio_thread_init) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_thread_init", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -115,7 +115,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (int (*)(struct mr_vdev *, queue_id_t, marsio_buff_t **, int))dlsym(marsio_so_handle, "marsio_recv_burst");
 	if (nullptr == g_marsio_dll_func.marsio_recv_burst) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_recv_burst", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -123,7 +123,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (int (*)(struct mr_sendpath *,  queue_id_t, marsio_buff_t **, int))dlsym(marsio_so_handle, "marsio_send_burst");
 	if (nullptr == g_marsio_dll_func.marsio_send_burst) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_send_burst", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -132,7 +132,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				 marsio_buff_t **, int, uint16_t))dlsym(marsio_so_handle, "marsio_send_burst_with_options");
 	if (nullptr == g_marsio_dll_func.marsio_send_burst_with_options) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_send_burst_with_options", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -141,7 +141,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				 unsigned int, int, int))dlsym(marsio_so_handle, "marsio_buff_malloc_global");
 	if (nullptr == g_marsio_dll_func.marsio_buff_malloc_global) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_malloc_global", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -150,7 +150,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				  unsigned int, int, int))dlsym(marsio_so_handle, "marsio_buff_free");
 	if (nullptr == g_marsio_dll_func.marsio_buff_free) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_free", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -158,7 +158,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (char * (*)(marsio_buff_t *, uint16_t))dlsym(marsio_so_handle, "marsio_buff_append");
 	if (nullptr == g_marsio_dll_func.marsio_buff_append) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_append", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -166,7 +166,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (void * (*)(marsio_buff_t *, uint8_t))dlsym(marsio_so_handle, "marsio_buff_ctrlzone");
 	if (nullptr == g_marsio_dll_func.marsio_buff_ctrlzone) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_ctrlzone", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -175,7 +175,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				  void *, uint8_t))dlsym(marsio_so_handle, "marsio_buff_ctrlzone_set");
 	if (nullptr == g_marsio_dll_func.marsio_buff_ctrlzone_set) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_ctrlzone_set", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -183,28 +183,28 @@ static int pio_get_marsio_dll_function_entries(void)
         (void (*)(marsio_buff_t *, uint32_t))dlsym(marsio_so_handle, "marsio_buff_set_rehash_index");
 	if (nullptr == g_marsio_dll_func.marsio_buff_set_rehash_index) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_set_rehash_index", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		g_marsio_dll_func.marsio_buff_set_rehash_index = fake_marsio_buff_set_rehash_index;
 	}
 
 	g_marsio_dll_func.marsio_buff_mtod = (char * (*)(marsio_buff_t *))dlsym(marsio_so_handle, "marsio_buff_mtod");
 	if (nullptr == g_marsio_dll_func.marsio_buff_mtod) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_mtod", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
 	g_marsio_dll_func.marsio_buff_datalen = (uint32_t (*)(marsio_buff_t *))dlsym(marsio_so_handle, "marsio_buff_datalen");
 	if (nullptr == g_marsio_dll_func.marsio_buff_datalen) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_datalen", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
 	g_marsio_dll_func.marsio_buff_buflen = (uint32_t (*)(marsio_buff_t *))dlsym(marsio_so_handle, "marsio_buff_buflen");
 	if (nullptr == g_marsio_dll_func.marsio_buff_buflen) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_buflen", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -213,7 +213,7 @@ static int pio_get_marsio_dll_function_entries(void)
 							int, int, uint16_t))dlsym(marsio_so_handle, "marsio_buff_clone_with_options");
 	if (nullptr == g_marsio_dll_func.marsio_buff_clone_with_options) {
 		printf("\033[1;31;40m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_clone_with_options", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 		return -1;
 	}
 
@@ -222,7 +222,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (void (*)(struct mr_sendpath *, queue_id_t))dlsym(marsio_so_handle, "marsio_send_burst_flush");
 	if (nullptr == g_marsio_dll_func.marsio_send_burst_flush) {
 		printf("\033[33m[Warning]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_send_burst_flush", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
 	}
 
     /* for vlan flipping */
@@ -231,7 +231,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				 void *, unsigned int))dlsym(marsio_so_handle, "marsio_buff_get_metadata");
     if (nullptr == g_marsio_dll_func.marsio_buff_get_metadata) {
         printf("\033[33m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_get_metadata", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
         /* 
 			in order to be forward compatible with the previous version of mrzcpd, no error is returned here. 
 			vlan_flipping will become invalid 
@@ -243,7 +243,7 @@ static int pio_get_marsio_dll_function_entries(void)
 				 void *, unsigned int))dlsym(marsio_so_handle, "marsio_buff_set_metadata");
     if (nullptr == g_marsio_dll_func.marsio_buff_get_metadata) {
         printf("\033[33m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_set_metadata", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
         /* 
 			in order to be forward compatible with the previous version of mrzcpd, no error is returned here. 
 			vlan_flipping will become invalid 
@@ -254,7 +254,7 @@ static int pio_get_marsio_dll_function_entries(void)
         (int (*)(marsio_buff_t *, enum mr_buff_metadata_type))dlsym(marsio_so_handle, "marsio_buff_unset_metadata");
     if (nullptr == g_marsio_dll_func.marsio_buff_unset_metadata) {
         printf("\033[33m[Error]dlsym function '%s' from '%s' failed!\033[0m\n", "marsio_buff_unset_metadata", 
-				g_engine_instance.config.lib.libmarsio_path);
+				g_packet_io_config.marsio.libmarsio_path);
         /* 
 			in order to be forward compatible with the previous version of mrzcpd, no error is returned here. 
 			vlan_flipping will become invalid 
@@ -264,7 +264,7 @@ static int pio_get_marsio_dll_function_entries(void)
     return 0;
 }
 
-int pio_marsio_device_open(struct packet_io_device *pdev) 
+ssize_t pio_marsio_device_open(struct packet_io_device *pdev) 
 {
 	if (nullptr == pdev) {
 		log_error(ST_ERR_PIO_MARSIO_DEVICE, "invalid packet_io_device pointer.");
@@ -282,7 +282,7 @@ int pio_marsio_device_open(struct packet_io_device *pdev)
 		return -1;
 	}
 
-	pdev->entity.marsio_dev_ctx->pio_dev = pdev;
+	pdev->entity.marsio_dev_ctx->pdev = pdev;
 
 	struct mr_instance *mr_inst_handle = pdev->ppio_inst->entity.marsio_inst_ctx->mr_inst_handle;
 	/* marsio_open_device() return marsio device handle*/
@@ -304,7 +304,7 @@ int pio_marsio_device_open(struct packet_io_device *pdev)
     return 0;
 }
 
-int pio_marsio_device_close(struct packet_io_device *pdev) 
+ssize_t pio_marsio_device_close(struct packet_io_device *pdev) 
 {
 	if (nullptr == pdev) {
 		log_error(ST_ERR_PIO_MARSIO_DEVICE, "invalid pdev pointer so close marsio device failed!");
@@ -319,12 +319,12 @@ int pio_marsio_device_close(struct packet_io_device *pdev)
     return 0;
 }
 
-int pio_marsio_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts) 
+ssize_t pio_marsio_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts) 
 {
 	struct mr_vdev *mr_dev_handle = pdev->entity.marsio_dev_ctx->mr_dev_handle;
 	marsio_buff_t *rx_buff[MARSIO_BURST_PKT_MAX];
 
-	int recv_res = g_marsio_dll_func.marsio_recv_burst(mr_dev_handle, rxq_id, rx_buff, nr_pkts);
+	ssize_t recv_res = g_marsio_dll_func.marsio_recv_burst(mr_dev_handle, rxq_id, rx_buff, nr_pkts);
 	/* receive some pkts, copy mbuf pointer to packet structure */
 	if (recv_res > 0) {
 		for (int i = 0; i < recv_res; i++) {
@@ -335,10 +335,10 @@ int pio_marsio_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, st
 	return recv_res;
 }
 
-int pio_marsio_device_send(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts) 
+ssize_t pio_marsio_device_send(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts) 
 {
 	struct mr_sendpath *sendpath_handle = pdev->entity.marsio_dev_ctx->mr_sendpath_handle;
-	int ret = g_marsio_dll_func.marsio_send_burst(sendpath_handle, txq_id, (marsio_buff_t **)pkts, nr_pkts);
+	ssize_t ret = g_marsio_dll_func.marsio_send_burst(sendpath_handle, txq_id, (marsio_buff_t **)pkts, nr_pkts);
 	if (ret < 0) {
 		g_marsio_dll_func.marsio_buff_free(pdev->ppio_inst->entity.marsio_inst_ctx->mr_inst_handle, 
 				(marsio_buff_t **)pkts, nr_pkts, MARSIO_SOCKET_ID_ANY, txq_id);
@@ -347,15 +347,15 @@ int pio_marsio_device_send(struct packet_io_device *pdev, uint16_t txq_id, struc
 	return ret;
 }
 
-void pio_marsio_device_pkt_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts)
+void pio_marsio_device_pkt_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts)
 {
 	struct mr_instance *mr_inst = pdev->ppio_inst->entity.marsio_inst_ctx->mr_inst_handle;
 	g_marsio_dll_func.marsio_buff_free(mr_inst, (marsio_buff_t **)pkts, nr_pkts, MARSIO_SOCKET_ID_ANY, qid);
 }
 
-static int marsio_instance_init(struct packet_io_instance *pinst) 
+static ssize_t marsio_instance_init(struct packet_io_instance *pinst) 
 {
-	int ret = -1;
+	ssize_t ret = -1;
 	ret = pio_get_marsio_dll_function_entries();
     if (ret < 0) {
         printf("\033[1;31;40m[Error]dlopen marsio.so symbol failed!\033[0m\n");
@@ -368,7 +368,7 @@ static int marsio_instance_init(struct packet_io_instance *pinst)
 		return -1;
 	}
 
-	int wrk_thread_num = g_engine_instance.config.packet_io.thread_num;
+	int wrk_thread_num = g_packet_io_config.common.thread_num;
 	/* TODO: MARSIO_OPT_THREAD_NUM */
 	ret = g_marsio_dll_func.marsio_option_set(pinst->entity.marsio_inst_ctx->mr_inst_handle, 
 											  MARSIO_OPT_THREAD_NUM, 
@@ -390,7 +390,7 @@ static int marsio_instance_init(struct packet_io_instance *pinst)
     return 0;
 }
 
-int pio_marsio_instance_create(struct packet_io_instance *pinst) 
+ssize_t pio_marsio_instance_create(struct packet_io_instance *pinst) 
 {
 	if (nullptr == pinst) {
 		log_error(ST_ERR_PIO_MARSIO_INSTANCE, "invalid marsio instance pointer.");
@@ -404,7 +404,7 @@ int pio_marsio_instance_create(struct packet_io_instance *pinst)
 	}
 
 	/* instance init */
-    int ret = marsio_instance_init(pinst);
+    ssize_t ret = marsio_instance_init(pinst);
     if (ret < 0) {
         log_error(ST_ERR_PIO_MARSIO_INSTANCE, "marsio instance init failed.");
         return -1;
@@ -418,30 +418,24 @@ void pio_marsio_instance_destroy(struct packet_io_instance *pinst)
 	g_marsio_dll_func.marsio_destroy(pinst->entity.marsio_inst_ctx->mr_inst_handle);
 	FREE(pinst->entity.marsio_inst_ctx);
 
-	for (uint32_t i = 0; i < pinst->dev_cnt; i++) {
-		pio_marsio_device_close(pinst->devices[i]);
-		FREE(pinst->devices[i]);
+	struct packet_io_device *node = nullptr;
+    while ((node = TAILQ_FIRST(&pinst->device_queue_head)) != nullptr) {
+		TAILQ_REMOVE(&pinst->device_queue_head, node, next);
+		pinst->dev_cnt--;
+        pio_marsio_device_close(node);
+		FREE(node);
 	}
 }
 
-void *pio_marsio_device_buff_ctrlzone(struct stellar_packet *p)
+char *pio_marsio_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len)
 {
 	int zone_id = 0;
-
-	return g_marsio_dll_func.marsio_buff_ctrlzone((marsio_buff_t *)p, zone_id);
+	*ctrlzone_len = (size_t)g_marsio_dll_func.marsio_buff_buflen((marsio_buff_t *)p);
+	return (char *)g_marsio_dll_func.marsio_buff_ctrlzone((marsio_buff_t *)p, zone_id);
 }
 
-char *pio_marsio_device_buff_mtod(struct stellar_packet *p)
+char *pio_marsio_device_buff_mtod(struct stellar_packet *p, size_t *data_len)
 {
+	*data_len = (size_t)g_marsio_dll_func.marsio_buff_datalen((marsio_buff_t *)p);
 	return g_marsio_dll_func.marsio_buff_mtod((marsio_buff_t *)p);
-}
-
-uint32_t pio_marsio_device_buff_buflen(struct stellar_packet *p)
-{
-	return g_marsio_dll_func.marsio_buff_buflen((marsio_buff_t *)p);
-}
-
-uint32_t pio_marsio_device_buff_datalen(struct stellar_packet *p)
-{
-	return g_marsio_dll_func.marsio_buff_datalen((marsio_buff_t *)p);
-}
+}
\ No newline at end of file
diff --git a/src/packet_io/marsio_mode/pio_marsio.h b/src/packet_io/marsio_mode/pio_marsio.h
index 0e4814a..cf640d6 100644
--- a/src/packet_io/marsio_mode/pio_marsio.h
+++ b/src/packet_io/marsio_mode/pio_marsio.h
@@ -98,7 +98,7 @@ struct pio_marsio_device_context {
     struct mr_vdev *mr_dev_handle;
     struct mr_sendpath * mr_sendpath_handle;
 
-    struct packet_io_device *pio_dev;
+    struct packet_io_device *pdev;
 };
 
 /**
@@ -107,7 +107,7 @@ struct pio_marsio_device_context {
  * @param pinst 
  * @return int 
  */
-int pio_marsio_instance_create(struct packet_io_instance *pinst);
+ssize_t pio_marsio_instance_create(struct packet_io_instance *pinst);
 
 /**
  * @brief 
@@ -124,12 +124,12 @@ void pio_marsio_instance_destroy(struct packet_io_instance *pinst);
  *        pdev->rxq_num:  number of the packet receiving queues for the device
  *        pdev->txq_num:  number of the packet sending queues for the device
  */
-int pio_marsio_device_open(struct packet_io_device *pdev);
+ssize_t pio_marsio_device_open(struct packet_io_device *pdev);
 
 /**
  * @brief close pcap_live device
  */
-int pio_marsio_device_close(struct packet_io_device *pdev);
+ssize_t pio_marsio_device_close(struct packet_io_device *pdev);
 
 /**
  * @brief receive packets from device's single rx queue which specified by rxq_id
@@ -141,7 +141,7 @@ int pio_marsio_device_close(struct packet_io_device *pdev);
  * 
  * @retval number of packets actually received
  */
-int pio_marsio_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t pio_marsio_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
 /**
  * @brief send packets by device's single tx queue which specified by txq_id
@@ -153,7 +153,7 @@ int pio_marsio_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, st
  * 
  * @retval if ret<0, means the sending fails; if ret==0 means the sending succeeds
  */
-int pio_marsio_device_send(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t pio_marsio_device_send(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
 /**
  * @brief manually free packet's memory
@@ -163,15 +163,11 @@ int pio_marsio_device_send(struct packet_io_device *pdev, uint16_t txq_id, struc
  * @param pkts:
  * @param nr_pkts:
  */
-void pio_marsio_device_pkt_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts);
+void pio_marsio_device_pkt_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts);
 
-void *pio_marsio_device_buff_ctrlzone(struct stellar_packet *p);
+char *pio_marsio_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len);
 
-char *pio_marsio_device_buff_mtod(struct stellar_packet *p);
-
-uint32_t pio_marsio_device_buff_buflen(struct stellar_packet *p);
-
-uint32_t pio_marsio_device_buff_datalen(struct stellar_packet *p);
+char *pio_marsio_device_buff_mtod(struct stellar_packet *p, size_t *data_len);
 
 #ifdef __cpluscplus
 }
diff --git a/src/packet_io/packet_io.cpp b/src/packet_io/packet_io.cpp
deleted file mode 100644
index 957034b..0000000
--- a/src/packet_io/packet_io.cpp
+++ /dev/null
@@ -1,203 +0,0 @@
-/*
-**********************************************************************************************
-*	File: packet_io.cpp
-*   Description: 
-*	Authors: Liu WenTan <[email protected]>
-*	Date:    2022-07-15
-*   Copyright: (c) 2018-2022 Geedge Networks, Inc. All rights reserved.
-***********************************************************************************************
-*/
-
-#include <string.h>
-
-#include "logger.h"
-#include "utils.h"
-#include "util_errors.h"
-#include "packet_io.h"
-
-struct pio_device_operations pio_device_ops_array[PACKET_IO_RUN_MODE_MAX] = 
-{
-	{
-		.open = pio_pcap_file_device_open,
-		.close = pio_pcap_file_device_close,
-		.recv = pio_pcap_file_device_receive,
-		.send = nullptr,
-		.pkt_free = pio_pcap_file_device_pkt_free,
-		.buff_ctrlzone = pio_pcap_file_device_buff_ctrlzone,
-		.buff_mtod = pio_pcap_file_device_buff_mtod,
-		.buff_buflen = pio_pcap_file_device_buff_buflen,
-		.buff_datalen = pio_pcap_file_device_buff_datalen,
-	},
-
-	{
-		.open = pio_pcap_live_device_open,
-		.close = pio_pcap_live_device_close,
-		.recv = pio_pcap_live_device_receive,
-		.send = pio_pcap_live_device_send,
-		.pkt_free = pio_pcap_live_device_pkt_free,
-		.buff_ctrlzone = pio_pcap_live_device_buff_ctrlzone,
-		.buff_mtod = pio_pcap_live_device_buff_mtod,
-		.buff_buflen = pio_pcap_live_device_buff_buflen,
-		.buff_datalen = pio_pcap_live_device_buff_datalen,
-	},
-	
-	{
-		.open = pio_marsio_device_open,
-		.close = pio_marsio_device_close,
-		.recv = pio_marsio_device_receive,
-		.send = pio_marsio_device_send,
-		.pkt_free = pio_marsio_device_pkt_free,
-		.buff_ctrlzone = pio_marsio_device_buff_ctrlzone,
-		.buff_mtod = pio_marsio_device_buff_mtod,
-		.buff_buflen = pio_marsio_device_buff_buflen,
-		.buff_datalen = pio_marsio_device_buff_datalen,
-	}
-};
-
-struct pio_instance_operations pio_instance_ops_array[PACKET_IO_RUN_MODE_MAX] = 
-{
-	{
-		.create = pio_pcap_file_instance_create,
-		.destroy = pio_pcap_file_instance_destroy,
-	},
-
-	{
-		.create = pio_pcap_live_instance_create,
-		.destroy = pio_pcap_live_instance_destroy,
-	},
-
-	{
-		.create = pio_marsio_instance_create,
-		.destroy = pio_marsio_instance_destroy,
-	}
-};
-
-struct packet_io_instance *
-packet_io_instance_create(const char *inst_name, const enum packet_io_run_mode mode) 
-{
-	if (nullptr == inst_name || mode < PACKET_IO_RUN_MODE_PCAP_FILE || mode >= PACKET_IO_RUN_MODE_MAX) {
-		return nullptr;
-	}
-
-	struct packet_io_instance *pio_instance = CALLOC(struct packet_io_instance, 1);
-	if (nullptr == pio_instance) {
-		log_error(ST_ERR_MEM_ALLOC, "packet_io instance alloc failed.");
-		return nullptr;
-	}
-
-	int ret = strncpy_safe(pio_instance->inst_name, inst_name, sizeof(pio_instance->inst_name));
-	if (ret < 0) {
-		log_error(ST_ERR_STR_COPY, "packet_io instance name copy failed.");
-		return nullptr;
-	}
-
-	pio_instance->mode = mode;
-	pio_instance->inst_ops = &pio_instance_ops_array[mode];
-	
-	ret = pio_instance->inst_ops->create(pio_instance);
-	if (ret < 0) {
-		log_error(ST_ERR_PIO_INSTANCE, "packet_io instance create failed.");
-		return nullptr;
-	}
-	
-	return pio_instance;
-}
-
-void packet_io_instance_destroy(struct packet_io_instance *pinst) {
-	if (nullptr == pinst) {
-		return;
-	}
-
-	pinst->inst_ops->destroy(pinst);
-	FREE(pinst);
-}
-
-struct packet_io_device *
-packet_io_device_open(struct packet_io_instance *pinst, const char *dev_name, uint16_t nr_rxq, uint16_t nr_txq)
-{
-	struct packet_io_device *ppio_dev = CALLOC(struct packet_io_device, 1);
-	if (nullptr == ppio_dev) {
-		log_error(ST_ERR_MEM_ALLOC, "packet_io device alloc failed.");
-		return nullptr;
-	}
-
-	int ret = strncpy_safe(ppio_dev->dev_name, dev_name, sizeof(ppio_dev->dev_name));
-	if (ret < 0) {
-		log_error(ST_ERR_STR_COPY, "packet_io device name copy failed.");
-		return nullptr;
-	}
-
-	ppio_dev->rxq_num = nr_rxq;
-	ppio_dev->txq_num = nr_txq;
-	ppio_dev->ppio_inst = pinst;
-	ppio_dev->dev_ops = &pio_device_ops_array[pinst->mode];
-
-	/* 
-	 * ppio_inst->devices  -->  | struct packet_io_device * | struct packet_io_device * | struct packet_io_device * |
-										array[0]                     array[1]                    array[2]
-	**/
-	pinst->devices[pinst->dev_cnt++] = ppio_dev;
-
-	ret = ppio_dev->dev_ops->open(ppio_dev);
-	if (ret < 0) {
-		log_error(ST_ERR_PIO_DEVICE, "packet_io device open failed.");
-		FREE(ppio_dev);
-		return nullptr;
-	}
-	
-	return ppio_dev;
-}
-
-void packet_io_device_close(struct packet_io_device *pdev)
-{
-	if (nullptr == pdev) {
-		return;
-	}
-
-	if (nullptr == pdev->dev_ops) {
-		FREE(pdev);
-		return;
-	}
-
-	int ret = pdev->dev_ops->close(pdev);
-	if (ret < 0) {
-		log_error(ST_ERR_PIO_DEVICE, "packet_io device close failed.");
-	}
-
-	FREE(pdev);
-}
-
-int packet_io_device_rx(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts)
-{
-	return pdev->dev_ops->recv(pdev, rxq_id, pkts, nr_pkts);
-}
-
-int packet_io_device_tx(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts)
-{
-	return pdev->dev_ops->send(pdev, txq_id, pkts, nr_pkts);
-}
-
-void packet_io_pkts_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts)
-{
-	return pdev->dev_ops->pkt_free(pdev, qid, pkts, nr_pkts);
-}
-
-void *packet_io_buff_ctrlzone(struct packet_io_device *pdev, struct stellar_packet *p)
-{
-	return pdev->dev_ops->buff_ctrlzone(p);
-}
-
-char *packet_io_buff_mtod(struct packet_io_device *pdev, struct stellar_packet *p)
-{
-	return pdev->dev_ops->buff_mtod(p);
-}
-
-uint32_t packet_io_buff_buflen(struct packet_io_device *pdev, struct stellar_packet *p)
-{
-	return pdev->dev_ops->buff_buflen(p);
-}
-
-uint32_t packet_io_buff_datalen(struct packet_io_device *pdev, struct stellar_packet *p)
-{
-	return pdev->dev_ops->buff_datalen(p);
-}
diff --git a/src/packet_io/packet_io.h b/src/packet_io/packet_io.h
index fc55082..868bb15 100644
--- a/src/packet_io/packet_io.h
+++ b/src/packet_io/packet_io.h
@@ -17,119 +17,50 @@ extern "C"
 #endif
 
 #include <stdint.h>
-#include <limits.h>
-#include <sys/queue.h>
+#include <stddef.h>
+#include <sys/types.h>
+
+enum packet_io_run_mode {
+	PACKET_IO_RUN_MODE_PCAP_FILE,
+	PACKET_IO_RUN_MODE_PCAP_LIVE,
+	PACKET_IO_RUN_MODE_MARSIO,
+	PACKET_IO_RUN_MODE_MAX,
+};
 
-#include "global_var.h"
-#include "./pcap_live_mode/pio_pcap_live.h"
-#include "./pcap_file_mode/pio_pcap_file.h"
-#include "./marsio_mode/pio_marsio.h"
+struct packet_io_instance;
+struct packet_io_device;
 
 /**
- * note:
- *	1. packet_io_XXX function is supported by packet_io.h
- *	2. pio_XXX function is supported by pio_pcap_live.h/pio_pcap_file.h/pio_marsio.h
+ * @brief 
+ * 
+ * @param instance_name:   packet_io instance's name 
+ * @param filename:        packet_io config file's name 
+ * @param devices(in/out): return packet_io_device pointer array, each pointer stands for an opened packet_io device 
+ * @param dev_num:         the num of opened packet_io_device's pointer
+ * @return struct packet_io_instance* 
  */
+struct packet_io_instance *
+packet_io_init(const char *instance_name, const char *filename, struct packet_io_device *devices[], size_t *dev_num);
 
-struct pio_instance_operations {
-	int (*create)(struct packet_io_instance *pinst);
-
-	void (*destroy)(struct packet_io_instance *pinst);
-};
-
-struct packet_io_instance {
-	/* packet_io instance name */
-	char inst_name[NAME_MAX];
-
-	/* packet_io run mode of the instance */
-	enum packet_io_run_mode mode;
-
-	/* device handle set in this instance */
-	struct packet_io_device *devices[DEV_MAX_CNT];
-
-	/* device's exactly count */
-	uint32_t dev_cnt;
-
-	/* instance operations */
-	struct pio_instance_operations *inst_ops;
-
-	union 
-	{
-		struct pio_pcap_file_instance_context *pcap_file_inst_ctx;
-		struct pio_pcap_live_instance_context *pcap_live_inst_ctx;
-		struct pio_marsio_instance_context *marsio_inst_ctx;
-	} entity;
-};
-
-struct pio_device_operations {
-	int (*open)(struct packet_io_device *pdev);
-
-	int (*close)(struct packet_io_device *pdev);
-
-	int (*recv)(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts);
-
-	int (*send)(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts);
-
-	void (*pkt_free)(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts);
-
-	void *(*buff_ctrlzone)(struct stellar_packet *p);
-
-	char *(*buff_mtod)(struct stellar_packet *p);
-
-	uint32_t (*buff_buflen)(struct stellar_packet *p);
-
-	uint32_t (*buff_datalen)(struct stellar_packet *p);
-};
-
-struct packet_io_device {
-	/* device name */
-	char dev_name[NAME_MAX];
-
-	/* device operations */
-	struct pio_device_operations *dev_ops;
-
-	/* number of receive queue */
-	uint16_t rxq_num;
-
-	/* number of send queue */
-	uint16_t txq_num;
-
-	/* packet io device context */
-	union {
-		struct pio_pcap_file_device_context *pcap_file_dev_ctx;
-		struct pio_pcap_live_device_context *pcap_live_dev_ctx;
-		struct pio_marsio_device_context *marsio_dev_ctx;
-	} entity;
-
-	/* packet_io instance which the device belongs to */
-	struct packet_io_instance *ppio_inst;
-};
+/* destroy packet_io instance */
+void packet_io_fini(struct packet_io_instance *pinst);
 
 /**
- * @brief create packet_io instance which will manage packet_io device
- *
- * @param instance_name:     packet_io instance name
- * @param mode:              packet_io run mode
+ * @brief 
+ * 
+ * @param inst_name 
+ * @param mode 
+ * @return struct packet_io_instance* 
  */
 struct packet_io_instance *
-packet_io_instance_create(const char *instance_name, const enum packet_io_run_mode mode);
+packet_io_instance_create(const char *inst_name, const enum packet_io_run_mode mode);
 
-/* destroy packet_io instance */
 void packet_io_instance_destroy(struct packet_io_instance *pinst);
 
-/**
- * @brief open packet_io device for send/receive packets
- *
- * @param pinst:    packet_io instance pointer
- * @param dev_name: packet_io device name
- * @param nr_rxq:   number of receive queue for the device
- * @param nr_txq:   number of send queue for the device
- */
 struct packet_io_device *
-packet_io_device_open(struct packet_io_instance *pinst, const char *dev_name, uint16_t nr_rxq, uint16_t nr_txq);
+packet_io_device_open(struct packet_io_instance *pinst, const char *dev_name, size_t nr_rxq, size_t nr_txq);
 
-/** close packet_io device */
-void packet_io_device_close(struct packet_io_device *dev);
+void packet_io_device_close(struct packet_io_device *pdev);
 
 /**
  * @brief packet_io device receive function
@@ -139,7 +70,7 @@ void packet_io_device_close(struct packet_io_device *dev);
  * @param p:      received packet's pointer array
  * @param nr_p:   number of received packets
  */
-int packet_io_device_rx(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t packet_io_device_rx(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
 /**
  * @brief packet_io device send function
@@ -149,33 +80,12 @@ int packet_io_device_rx(struct packet_io_device *pdev, uint16_t rxq_id, struct s
  * @param p:      prepare to send packet's pointer array
  * @param nr_p:   number of packets which prepare to send
  */
-int packet_io_device_tx(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t packet_io_device_tx(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
 /*
  * @brief packet_io free packet buff
  */
-void packet_io_pkts_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts);
-
-/**
- * @brief get packet_io packet's ctrlzone 
- * @note ctrlzone's memory is 64 bytes, do not exceed it
- */
-void *packet_io_buff_ctrlzone(struct packet_io_device *pdev, struct stellar_packet *p);
-
-/**
- * @brief get packet_io packet's data pointer
- */
-char *packet_io_buff_mtod(struct packet_io_device *pdev, struct stellar_packet *p);
-
-/**
- * @brief get packet_io packet's buffer length
- */
-uint32_t packet_io_buff_buflen(struct packet_io_device *pdev, struct stellar_packet *p);
-
-/**
- * @brief get packet_io packet's data length
- */
-uint32_t packet_io_buff_datalen(struct packet_io_device *pdev, struct stellar_packet *p);
+void packet_io_pkts_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts);
 
 #ifdef __cpluscplus
 }
diff --git a/src/packet_io/packet_io_internal.cpp b/src/packet_io/packet_io_internal.cpp
new file mode 100644
index 0000000..0a9e78e
--- /dev/null
+++ b/src/packet_io/packet_io_internal.cpp
@@ -0,0 +1,461 @@
+/*
+**********************************************************************************************
+*	File: packet_io_internal.cpp
+*   Description:
+*	Authors: Liu WenTan <[email protected]>
+*	Date:    2022-07-15
+*   Copyright: (c) 2018-2022 Geedge Networks, Inc. All rights reserved.
+***********************************************************************************************
+*/
+
+#include <string.h>
+
+#include "logger.h"
+#include "utils.h"
+#include "util_errors.h"
+#include "packet_io.h"
+#include "packet_io_util.h"
+#include "packet_io_internal.h"
+#include "toml/toml.h"
+#include "./pcap_live_mode/pio_pcap_live.h"
+#include "./pcap_file_mode/pio_pcap_file.h"
+#include "./marsio_mode/pio_marsio.h"
+
+struct packet_io_config g_packet_io_config;
+
+struct pio_device_operations pio_device_ops_array[PACKET_IO_RUN_MODE_MAX] = 
+{
+	{
+		.open = pio_pcap_file_device_open,
+		.close = pio_pcap_file_device_close,
+		.recv = pio_pcap_file_device_receive,
+		.send = nullptr,
+		.pkt_free = pio_pcap_file_device_pkt_free,
+		.buff_ctrlzone = pio_pcap_file_device_buff_ctrlzone,
+		.buff_mtod = pio_pcap_file_device_buff_mtod,
+	},
+
+	{
+		.open = pio_pcap_live_device_open,
+		.close = pio_pcap_live_device_close,
+		.recv = pio_pcap_live_device_receive,
+		.send = pio_pcap_live_device_send,
+		.pkt_free = pio_pcap_live_device_pkt_free,
+		.buff_ctrlzone = pio_pcap_live_device_buff_ctrlzone,
+		.buff_mtod = pio_pcap_live_device_buff_mtod,
+	},
+	
+	{
+		.open = pio_marsio_device_open,
+		.close = pio_marsio_device_close,
+		.recv = pio_marsio_device_receive,
+		.send = pio_marsio_device_send,
+		.pkt_free = pio_marsio_device_pkt_free,
+		.buff_ctrlzone = pio_marsio_device_buff_ctrlzone,
+		.buff_mtod = pio_marsio_device_buff_mtod,
+	}
+};
+
+struct pio_instance_operations pio_instance_ops_array[PACKET_IO_RUN_MODE_MAX] = 
+{
+	{
+		.create = pio_pcap_file_instance_create,
+		.destroy = pio_pcap_file_instance_destroy,
+	},
+
+	{
+		.create = pio_pcap_live_instance_create,
+		.destroy = pio_pcap_live_instance_destroy,
+	},
+
+	{
+		.create = pio_marsio_instance_create,
+		.destroy = pio_marsio_instance_destroy,
+	}
+};
+
+struct packet_io_instance *
+packet_io_instance_create(const char *inst_name, const enum packet_io_run_mode mode) 
+{
+	if (nullptr == inst_name || mode < PACKET_IO_RUN_MODE_PCAP_FILE || mode >= PACKET_IO_RUN_MODE_MAX) {
+		return nullptr;
+	}
+
+	struct packet_io_instance *pio_instance = CALLOC(struct packet_io_instance, 1);
+	if (nullptr == pio_instance) {
+		log_error(ST_ERR_MEM_ALLOC, "packet_io instance alloc failed.");
+		return nullptr;
+	}
+
+	ssize_t ret = strncpy_safe(pio_instance->inst_name, inst_name, sizeof(pio_instance->inst_name));
+	if (ret < 0) {
+		log_error(ST_ERR_STR_COPY, "packet_io instance name copy failed.");
+		return nullptr;
+	}
+
+	TAILQ_INIT(&pio_instance->device_queue_head);
+	pio_instance->mode = mode;
+	pio_instance->inst_ops = &pio_instance_ops_array[mode];
+	
+	ret = pio_instance->inst_ops->create(pio_instance);
+	if (ret < 0) {
+		log_error(ST_ERR_PIO_INSTANCE, "packet_io instance create failed.");
+		return nullptr;
+	}
+	
+	return pio_instance;
+}
+
+static ssize_t toml_parse_table(toml_table_t *table, const char *string_key, const char *file_name, toml_table_t **out)
+{
+	*out = toml_table_in(table, string_key);
+	if (nullptr == *out) {
+		log_error(ST_ERR_PIO_CONFIG, "can't find '%s' section in %s", string_key, file_name);
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t toml_parse_string(toml_table_t *table, const char *string_key, const char *file_name, char *out)
+{
+    toml_datum_t string_val = toml_string_in(table, string_key);
+    if (!string_val.ok) {
+        log_error(ST_ERR_PIO_CONFIG, "can't find '%s' configuration iterm in %s", string_key, file_name);
+        return -1;
+    }
+
+    if (strlen(string_val.u.s) <= 0) {
+        log_error(ST_ERR_PIO_CONFIG, "invalid value for '%s' configuration item in %s", string_key, file_name);
+        FREE(string_val.u.s);
+        return -1;
+    }
+
+	strncpy_safe(out, string_val.u.s, strlen(string_val.u.s));
+    FREE(string_val.u.s);
+
+    return 0;
+}
+
+static ssize_t toml_parse_int(toml_table_t *table, const char *int_key, const char *file_name, int *out)
+{
+    toml_datum_t int_val = toml_int_in(table, int_key);
+    if (!int_val.ok) {
+        log_error(ST_ERR_PIO_CONFIG, "can't find '%s' configuration iterm in %s", int_key, file_name);
+        return -1;
+    }
+	*out = int_val.u.i;
+
+    return 0;
+}
+
+enum packet_io_run_mode pio_run_mode_str2int(const char *mode_str)
+{
+	enum packet_io_run_mode mode_int = PACKET_IO_RUN_MODE_MAX;
+	if (strncmp("PCAP_FILE_MODE", mode_str, strlen(mode_str)) == 0) {
+		mode_int = PACKET_IO_RUN_MODE_PCAP_FILE;
+	} else if (strncmp("PCAP_LIVE_MODE", mode_str, strlen(mode_str)) == 0) {
+		mode_int = PACKET_IO_RUN_MODE_PCAP_LIVE;
+	} else if (strncmp("MARSIO_MODE", mode_str, strlen(mode_str)) == 0) {
+		mode_int = PACKET_IO_RUN_MODE_MARSIO;
+	} else {
+		log_error(ST_ERR_RUN_MODE, "unknown run mode '%s'", mode_str);
+	}
+
+	return mode_int;
+}
+
+static ssize_t toml_parse_pcap_file_mode(toml_table_t *tab, struct packet_io_config *config, const char *file_name)
+{
+	if (toml_parse_string(tab, "PCAP_FILE_PATH", file_name, config->pcap.path) < 0) {
+		log_error(ST_ERR_PIO_CONFIG, "can't parse 'PCAP_FILE_PATH' config iterm in 'PACKET_IO' section of %s", file_name);
+		return -1;
+	}
+
+	if (toml_parse_int(tab, "DELETE_WHEN_DONE", file_name, &config->pcap.should_delete) < 0) {
+		log_notice("can't parse 'DELETE_WHEN_DONE' config iterm in 'PACKET_IO' section of %s", file_name);
+	}
+
+	if (toml_parse_string(tab, "BPF_FILTER", file_name, config->pcap.bpf_string) < 0) {
+		log_notice("can't parse 'BPF_FILTER' config iterm in 'PACKET_IO' section of %s", file_name);
+	}
+
+	return 0;
+}
+
+static ssize_t toml_parse_pcap_live_mode(toml_table_t *tab, struct packet_io_config *config, const char *file_name)
+{
+	toml_array_t *interface_array = nullptr;
+	toml_datum_t interface_str;
+
+	interface_array = toml_array_in(tab, "INTERFACE");
+	if (nullptr == interface_array) {
+		log_error(ST_ERR_PIO_CONFIG, "can't find 'INTERFACE' config iterm in 'PACKET_IO' section of %s", file_name);
+		return -1;
+	}
+
+	for (ssize_t i = 0; i < toml_array_nelem(interface_array); i++) {
+		interface_str = toml_string_at(interface_array, i);
+		if (!interface_str.ok) {
+			log_error(ST_ERR_PIO_CONFIG, "can't parse 'INTERFACE' config iterm in 'PACKET_IO' section of %s", file_name);
+			return -1;
+		}
+
+		strncpy_safe(config->common.dev_name[i], interface_str.u.s, sizeof(config->common.dev_name[i]));
+		config->common.dev_cnt++;
+	}
+
+	if (toml_parse_int(tab, "SNAP_LEN", file_name, &config->pcap.snaplen) < 0) {
+		log_notice("can't parse 'SNAP_LEN' config iterm in 'PACKET_IO' section of %s", file_name);
+	}
+
+	if (toml_parse_int(tab, "PROMISC", file_name, &config->pcap.promisc) < 0) {
+		log_notice("can't parse 'PROMISC' config iterm in 'PACKET_IO' section of %s", file_name);
+	}
+
+	if (toml_parse_string(tab, "BPF_FILTER", file_name, config->pcap.bpf_string) < 0) {
+		log_notice("can't parse 'BPF_FILTER' config iterm in 'PACKET_IO' section of %s", file_name);
+	}
+
+	return 0;
+}
+
+static ssize_t toml_parse_marsio_mode(toml_table_t *tab, struct packet_io_config *config, const char *file_name)
+{
+	toml_array_t *interface_array = nullptr;
+	toml_datum_t interface_str;
+
+	interface_array = toml_array_in(tab, "INTERFACE");
+	if (nullptr == interface_array) {
+		log_error(ST_ERR_PIO_CONFIG, "can't find 'INTERFACE' config iterm in 'PACKET_IO' section of %s", file_name);
+		return -1;
+	}
+
+	for (int i = 0; i < toml_array_nelem(interface_array); i++) {
+		interface_str = toml_string_at(interface_array, i);
+		if (!interface_str.ok) {
+			log_error(ST_ERR_PIO_CONFIG, "can't parse 'INTERFACE' config iterm in 'PACKET_IO' section of %s", file_name);
+			return -1;
+		}
+		strncpy_safe(config->common.dev_name[i], interface_str.u.s, sizeof(config->common.dev_name[i]));
+		config->common.dev_cnt++;
+	}
+
+	return 0;
+}
+
+static ssize_t toml_parse_packet_io_section(toml_table_t *root, struct packet_io_config *config, const char *file_name)
+{
+	toml_table_t *packet_io_section = nullptr;
+
+	if (toml_parse_table(root, "PACKET_IO", file_name, &packet_io_section) < 0) {
+		return -1;
+	}
+
+	char run_mode[STR_MAX_LEN] = {0};
+	if (toml_parse_string(packet_io_section, "RUN_MODE", file_name, run_mode) < 0) {
+		return -1;
+	}
+
+	config->common.mode = pio_run_mode_str2int(run_mode);
+	if (config->common.mode == PACKET_IO_RUN_MODE_MAX) {
+		return -1;
+	}
+
+	if (toml_parse_int(packet_io_section, "WORKER_THREAD_NUM", file_name, &config->common.thread_num) < 0) {
+		return -1;
+	}
+
+	if (config->common.mode == PACKET_IO_RUN_MODE_PCAP_FILE) {
+		if (toml_parse_pcap_file_mode(packet_io_section, config, file_name) < 0) {
+			return -1;
+		}
+	} else if (config->common.mode == PACKET_IO_RUN_MODE_PCAP_LIVE) {
+		if (toml_parse_pcap_live_mode(packet_io_section, config, file_name) < 0) {
+			return -1;
+		}
+	} else {
+		if (toml_parse_marsio_mode(packet_io_section, config, file_name) < 0) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+ssize_t packet_io_config_parse(struct packet_io_config *config, const char *file_name)
+{
+	char errbuf[BUFSIZ] = {0};
+
+	FILE *fp = fopen(file_name, "r");
+	if (nullptr == fp) {
+		log_error(ST_ERR_FOPEN, "open packet_io config file failed.");
+		return -1;
+	}
+	
+	toml_table_t *root = nullptr;
+	root = toml_parse_file(fp, errbuf, sizeof(errbuf));
+	if (nullptr == root) {
+		goto err;
+	}
+
+	if (toml_parse_packet_io_section(root, config, file_name) < 0) {
+		goto err;
+	}
+
+	toml_free(root);
+	fclose(fp);
+	log_info("packet_io config file '%s' parse success", file_name);
+
+	return 0;
+err:
+	if (root) {
+		toml_free(root);
+	}
+
+	if (fp) {
+		fclose(fp);
+		fp = nullptr;
+	}
+
+	return -1;
+}
+
+struct packet_io_device *
+packet_io_device_open(struct packet_io_instance *pinst, const char *dev_name, size_t nr_rxq, size_t nr_txq)
+{
+	if (nullptr == pinst || nullptr == dev_name) {
+		return nullptr;
+	}
+
+	struct packet_io_device *pdev = CALLOC(struct packet_io_device, 1);
+	if (nullptr == pdev) {
+		log_error(ST_ERR_MEM_ALLOC, "packet_io device alloc failed.");
+		return nullptr;
+	}
+
+	ssize_t ret = strncpy_safe(pdev->dev_name, dev_name, sizeof(pdev->dev_name));
+	if (ret < 0) {
+		log_error(ST_ERR_STR_COPY, "packet_io device name copy failed.");
+		return nullptr;
+	}
+
+	pdev->rxq_num = nr_rxq;
+	pdev->txq_num = nr_txq;
+	pdev->ppio_inst = pinst;
+	pdev->dev_ops = &pio_device_ops_array[pinst->mode];
+
+	TAILQ_INSERT_TAIL(&pinst->device_queue_head, pdev, next);
+	pinst->dev_cnt++;
+	
+	ret = pdev->dev_ops->open(pdev);
+	if (ret < 0) {
+		log_error(ST_ERR_PIO_DEVICE, "packet_io device open failed.");
+		return nullptr;
+	}
+
+	return pdev;
+}
+
+void packet_io_device_close(struct packet_io_device *pdev)
+{
+	ssize_t ret = pdev->dev_ops->close(pdev);
+	if (ret < 0) {
+		log_error(ST_ERR_PIO_DEVICE, "packet_io device close failed.");
+		return;
+	}
+
+	struct packet_io_device *node = nullptr;
+    struct packet_io_device *next_node = nullptr;
+    for (node = TAILQ_FIRST(&pdev->ppio_inst->device_queue_head); node != nullptr; node = next_node) {
+		next_node = TAILQ_NEXT(node, next);
+		if (node == pdev) {
+			pdev->ppio_inst->dev_cnt--;
+			/* Remove the item from the tail queue. */
+			TAILQ_REMOVE(&pdev->ppio_inst->device_queue_head, node, next);
+
+			/* Free the item as we don't need it anymore. */
+			FREE(node);
+			break;
+		}
+	}
+}
+
+struct packet_io_instance *
+packet_io_init(const char *instance_name, const char *file_name, struct packet_io_device *devices[], size_t *dev_num)
+{
+	/* parse config file */
+	memset(&g_packet_io_config, 0, sizeof(g_packet_io_config));
+	ssize_t ret = packet_io_config_parse(&g_packet_io_config, file_name);
+	if (ret < 0) {
+		log_error(ST_ERR_PIO_CONFIG, "packet_io config parse failed.");
+		return nullptr;
+	}
+
+	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", g_packet_io_config.common.mode);
+	if (nullptr == ppio_inst) {
+		log_error(ST_ERR_PIO_INSTANCE, "packet_io instance init failed.");
+		return nullptr;
+	}
+
+	size_t thread_num = g_packet_io_config.common.thread_num;
+	if (g_packet_io_config.common.mode == PACKET_IO_RUN_MODE_PCAP_FILE) {
+		devices[0] = packet_io_device_open(ppio_inst, g_packet_io_config.pcap.path, thread_num, thread_num);
+		if (nullptr == devices[0]) {
+			log_error(ST_ERR_PIO_DEVICE, "packet_io device '%s' open failed.", g_packet_io_config.pcap.path);
+			return nullptr;
+		}
+		*dev_num = 1;
+	} else {
+		*dev_num = g_packet_io_config.common.dev_cnt;
+		for (size_t i = 0; i < *dev_num; i++) {
+			devices[i] = packet_io_device_open(ppio_inst, g_packet_io_config.common.dev_name[i], thread_num, thread_num);
+			if (nullptr == devices[i]) {
+				log_error(ST_ERR_PIO_DEVICE, "packet_io device '%s' open failed.", g_packet_io_config.common.dev_name[i]);
+				return nullptr;
+			}
+		}
+	}
+
+	return ppio_inst;
+}
+
+void packet_io_fini(struct packet_io_instance *pinst)
+{
+	packet_io_instance_destroy(pinst);
+}
+
+void packet_io_instance_destroy(struct packet_io_instance *pinst)
+{
+	if (nullptr == pinst) {
+		return;
+	}
+
+	pinst->inst_ops->destroy(pinst);
+	FREE(pinst);
+}
+
+ssize_t packet_io_device_rx(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts)
+{
+	return pdev->dev_ops->recv(pdev, rxq_id, pkts, nr_pkts);
+}
+
+ssize_t packet_io_device_tx(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts)
+{
+	return pdev->dev_ops->send(pdev, txq_id, pkts, nr_pkts);
+}
+
+void packet_io_pkts_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts)
+{
+	return pdev->dev_ops->pkt_free(pdev, qid, pkts, nr_pkts);
+}
+
+char *get_stellar_packet_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len)
+{
+	return pio_device_ops_array[g_packet_io_config.common.mode].buff_ctrlzone(p, ctrlzone_len);
+}
+
+char *get_stellar_packet_data(struct stellar_packet *p, size_t *data_len)
+{
+	return pio_device_ops_array[g_packet_io_config.common.mode].buff_mtod(p, data_len);
+}
\ No newline at end of file
diff --git a/src/packet_io/packet_io_internal.h b/src/packet_io/packet_io_internal.h
new file mode 100644
index 0000000..e52dd7c
--- /dev/null
+++ b/src/packet_io/packet_io_internal.h
@@ -0,0 +1,155 @@
+/*
+**********************************************************************************************
+*	File: packet_io_internal.h
+*   Description: packet_io internal api 
+*	Authors: Liu WenTan <[email protected]>
+*	Date:    2022-07-15
+*   Copyright: (c) 2018-2022 Geedge Networks, Inc. All rights reserved.
+***********************************************************************************************
+*/
+
+#ifndef _PACKET_IO_INTERNAL_H_
+#define _PACKET_IO_INTERNAL_H_
+
+#ifdef __cpluscplus
+extern "C"
+{
+#endif
+
+#include <limits.h>
+#include <sys/queue.h>
+
+#include "packet_io_util.h"
+
+#define DEV_MAX_CNT 64
+
+/**
+ * note:
+ *	1. packet_io_XXX function is supported by packet_io.h
+ *	2. pio_XXX function is supported by pio_pcap_live.h/pio_pcap_file.h/pio_marsio.h
+ */
+
+struct pio_instance_operations {
+	ssize_t (*create)(struct packet_io_instance *pinst);
+
+	void (*destroy)(struct packet_io_instance *pinst);
+};
+
+struct packet_io_instance {
+	/* packet_io instance name */
+	char inst_name[NAME_MAX];
+
+	/* packet_io run mode of the instance */
+	enum packet_io_run_mode mode;
+
+	/* device handle set in this instance */
+	TAILQ_HEAD(pio_device_queue, packet_io_device) device_queue_head;
+
+	/* device's exactly count */
+	uint32_t dev_cnt;
+
+	/* instance operations */
+	struct pio_instance_operations *inst_ops;
+
+	union 
+	{
+		struct pio_pcap_file_instance_context *pcap_file_inst_ctx;
+		struct pio_pcap_live_instance_context *pcap_live_inst_ctx;
+		struct pio_marsio_instance_context *marsio_inst_ctx;
+	} entity;
+};
+
+struct pio_device_operations {
+	ssize_t (*open)(struct packet_io_device *pdev);
+
+	ssize_t (*close)(struct packet_io_device *pdev);
+
+	ssize_t (*recv)(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts);
+
+	ssize_t (*send)(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts);
+
+	void (*pkt_free)(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts);
+
+	char *(*buff_ctrlzone)(struct stellar_packet *p, size_t *ctrlzone_len);
+
+	char *(*buff_mtod)(struct stellar_packet *p, size_t *data_len);
+};
+
+struct packet_io_device {
+	/* device name */
+	char dev_name[NAME_MAX];
+
+	/* device operations */
+	struct pio_device_operations *dev_ops;
+
+	/* number of receive queue */
+	uint16_t rxq_num;
+
+	/* number of send queue */
+	uint16_t txq_num;
+
+	/* packet io device context */
+	union {
+		struct pio_pcap_file_device_context *pcap_file_dev_ctx;
+		struct pio_pcap_live_device_context *pcap_live_dev_ctx;
+		struct pio_marsio_device_context *marsio_dev_ctx;
+	} entity;
+
+	/* packet_io instance which the device belongs to */
+	struct packet_io_instance *ppio_inst;
+
+	TAILQ_ENTRY(packet_io_device) next;
+};
+
+struct pio_marsio_config {
+    /* marsio ctrlzone id */
+    int mr_ctrlzone_id;
+
+    const char *libmarsio_path;
+};
+
+struct pio_pcap_config {
+	char path[PATH_MAX];
+    /* bpf filter string, such as "tcp and port 25"*/
+    char bpf_string[STR_MAX_LEN];
+
+    /* delete after the pcap file is processed */
+    int should_delete;
+
+    //time_t delay;
+
+    /* snapshot length */
+    int snaplen;
+
+    /* promiscuous value */
+    int promisc;
+};
+
+struct pio_common_config {
+    /* packet_io run mode */
+	enum packet_io_run_mode mode;
+
+    /* worker thread num */
+    int thread_num;
+
+	/* device name list */
+	char dev_name[DEV_MAX_CNT][NAME_MAX];
+
+	/* device counts */
+	uint32_t dev_cnt;
+};
+
+/* store packet_io configuration */
+struct packet_io_config {
+	struct pio_common_config common;
+	struct pio_pcap_config pcap;
+	struct pio_marsio_config marsio;
+};
+
+extern struct packet_io_config g_packet_io_config;
+
+#ifdef __cpluscplus
+}
+#endif
+
+#endif /* _PACKET_IO_INTERNAL_H_ */
\ No newline at end of file
diff --git a/src/packet_io/packet_io_util.cpp b/src/packet_io/packet_io_util.cpp
index c5cc4ac..e94237f 100644
--- a/src/packet_io/packet_io_util.cpp
+++ b/src/packet_io/packet_io_util.cpp
@@ -16,14 +16,14 @@
 #include "utils.h"
 #include "packet_io_util.h"
 
-static int packet_copy_data_offset(uint8_t *ptr, uint32_t offset, const uint8_t *data, uint32_t data_len)
+static ssize_t packet_copy_data_offset(uint8_t *ptr, uint32_t offset, const uint8_t *data, uint32_t data_len)
 {
 	memcpy(ptr + offset, data, data_len);
 	
 	return 0;
 }
 
-int packet_copy_data(uint8_t *ptr, const uint8_t *pkt_data, uint32_t pkt_len)
+ssize_t packet_copy_data(uint8_t *ptr, const uint8_t *pkt_data, uint32_t pkt_len)
 {   
 	return packet_copy_data_offset(ptr, 0, pkt_data, pkt_len);
 }
@@ -99,12 +99,11 @@ void release_pio_packet_queue(struct pio_packet_queue *q)
 
     while (q->len != 0) {
         struct pio_packet *p = pio_packet_dequeue(q);
-        q->len--;
         FREE(p);
     }
 }
 
-int strncpy_safe(char *dst, const char *src, size_t dst_size)
+ssize_t strncpy_safe(char *dst, const char *src, size_t dst_size)
 {
 	if (nullptr == dst || nullptr == src || dst_size == 0) {
         return -1;
@@ -173,7 +172,7 @@ static uint64_t generic_2tuple_hash(uint8_t *src, uint8_t *dst, size_t n)
     uint64_t key1 = simple_murmur_hash(src, n);
     uint64_t key2 = simple_murmur_hash(dst, n);
 
-    return (key1 | key2);
+    return (key1 ^ key2);
 }
 
 uint64_t pio_packet_hash(struct pio_packet *p)
diff --git a/src/packet_io/packet_io_util.h b/src/packet_io/packet_io_util.h
index ddd2422..15cc1df 100644
--- a/src/packet_io/packet_io_util.h
+++ b/src/packet_io/packet_io_util.h
@@ -19,6 +19,8 @@ extern "C"
 #include <stdint.h>
 #include <pthread.h>
 
+#define STR_MAX_LEN 1024
+
 #ifndef DLT_EN10MB
 #define DLT_EN10MB 1
 #endif
@@ -82,9 +84,9 @@ struct pio_packet_queue {
  * 
  * @retval  -1(failed), 0(success)
  */
-int strncpy_safe(char *dst, const char *src, size_t dst_size);
+ssize_t strncpy_safe(char *dst, const char *src, size_t dst_size);
 
-int packet_copy_data(uint8_t *ptr, const uint8_t *pkt_data, uint32_t pkt_len);
+ssize_t packet_copy_data(uint8_t *ptr, const uint8_t *pkt_data, uint32_t pkt_len);
 
 /**
  * @brief ip hash function for struct pio_packet, 2 tuple(sip/dip) hash
diff --git a/src/packet_io/pcap_file_mode/pio_pcap_file.cpp b/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
index 024634b..17c3dce 100644
--- a/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
+++ b/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
@@ -22,6 +22,7 @@
 #include "pio_pcap_file.h"
 #include "packet_io.h"
 #include "packet_io_util.h"
+#include "packet_io_internal.h"
 
 /**
  * @brief validate path is a valid plain file or directory
@@ -30,10 +31,10 @@
  *         if success, dir == nullptr <---> means path is plain file
  *                     dir != nullptr <---> means path is directory
  */
-static int validate_directory_or_file(const char *path, DIR **dir) 
+static ssize_t validate_directory_or_file(const char *path, DIR **dir) 
 {
     DIR *temp_dir = nullptr;
-    int ret = -1;
+    ssize_t ret = -1;
 
     temp_dir = opendir(path);
     if (nullptr == temp_dir) {
@@ -79,7 +80,7 @@ static bool peek_first_packet_timestamp(struct pcap_plain_file_info *pfile_info)
     return true;
 }
 
-static int init_pcap_file(struct pcap_plain_file_info *pfile_info) 
+static ssize_t init_pcap_file(struct pcap_plain_file_info *pfile_info) 
 {
     char errbuf[PCAP_ERRBUF_SIZE] = "";
 
@@ -121,7 +122,7 @@ static int init_pcap_file(struct pcap_plain_file_info *pfile_info)
     return 0;
 }
 
-static int pcap_plain_file_init(struct pio_pcap_file_device_context *pfile_dev_ctx, const char *file_name) 
+static ssize_t pcap_plain_file_init(struct pio_pcap_file_device_context *pfile_dev_ctx, const char *file_name) 
 {
     if (nullptr == pfile_dev_ctx) {
         return -1;
@@ -154,7 +155,7 @@ static int pcap_plain_file_init(struct pio_pcap_file_device_context *pfile_dev_c
     return 0;
 }
 
-static int pcap_directory_file_init(struct pio_pcap_file_device_context *pfile_dev_ctx, const char *dir_name, DIR *directory) 
+static ssize_t pcap_directory_file_init(struct pio_pcap_file_device_context *pfile_dev_ctx, const char *dir_name, DIR *directory) 
 {
     if (nullptr == pfile_dev_ctx) {
         return -1;
@@ -173,7 +174,8 @@ static int pcap_directory_file_init(struct pio_pcap_file_device_context *pfile_d
 		return -1;
     }
 
-    //pdir_info->delay = 30;
+    /* TODO: if should configurable */
+    pdir_info->delay = 30;
     pdir_info->shared = &pfile_dev_ctx->shared;
     pdir_info->directory = directory;
     TAILQ_INIT(&pdir_info->file_queue_head);
@@ -184,17 +186,17 @@ static int pcap_directory_file_init(struct pio_pcap_file_device_context *pfile_d
     return 0;
 }
 
-static int pcap_file_shared_init(struct pio_pcap_file_device_context *pfile_dev_ctx) 
+static ssize_t pcap_file_shared_init(struct pio_pcap_file_device_context *pfile_dev_ctx) 
 {
     if (nullptr == pfile_dev_ctx) {
         return -1;
     }
 
     /* TODO: get conf and assign pfile_dev_ctx->shared */
-    if ((g_engine_instance.config.packet_io.mode == PACKET_IO_RUN_MODE_PCAP_FILE) &&
-        g_engine_instance.config.packet_io.bpf_string != nullptr) {
+    if ((g_packet_io_config.common.mode == PACKET_IO_RUN_MODE_PCAP_FILE) &&
+        g_packet_io_config.pcap.bpf_string != nullptr) {
         memset(pfile_dev_ctx->shared.bpf_string, 0, sizeof(pfile_dev_ctx->shared.bpf_string));
-        int ret = strncpy_safe(pfile_dev_ctx->shared.bpf_string, g_engine_instance.config.packet_io.bpf_string, 
+        ssize_t ret = strncpy_safe(pfile_dev_ctx->shared.bpf_string, g_packet_io_config.pcap.bpf_string, 
                           sizeof(pfile_dev_ctx->shared.bpf_string));
         if (ret < 0) {
             log_error(ST_ERR_STR_COPY, "pcap file bpf string copy failed.");
@@ -202,7 +204,7 @@ static int pcap_file_shared_init(struct pio_pcap_file_device_context *pfile_dev_
         }
     }
     
-    pfile_dev_ctx->shared.should_delete = g_engine_instance.config.packet_io.should_delete;
+    pfile_dev_ctx->shared.should_delete = g_packet_io_config.pcap.should_delete;
 
     /* init pcap file device packet queue */
 
@@ -239,9 +241,9 @@ static void cleanup_pcap_directory_info(struct pcap_file_directory_info *pdir_in
 
 }
 
-int pio_pcap_file_device_open(struct packet_io_device *pdev) 
+ssize_t pio_pcap_file_device_open(struct packet_io_device *pdev) 
 {
-    int status = -1;
+    ssize_t status = -1;
     DIR *directory = nullptr;
 
     if (nullptr == pdev) {
@@ -255,7 +257,7 @@ int pio_pcap_file_device_open(struct packet_io_device *pdev)
         return -1;
     }
 
-    pdev->entity.pcap_file_dev_ctx->pio_dev = pdev;
+    pdev->entity.pcap_file_dev_ctx->pdev = pdev;
 
     status = pcap_file_shared_init(pdev->entity.pcap_file_dev_ctx);
     if (status < 0) {
@@ -287,24 +289,26 @@ int pio_pcap_file_device_open(struct packet_io_device *pdev)
     return 0;
 }
 
-int pio_pcap_file_device_close(struct packet_io_device *pdev) 
+ssize_t pio_pcap_file_device_close(struct packet_io_device *pdev) 
 {
     if (nullptr == pdev) {
         log_error(ST_ERR_PIO_PCAP_FILE_DEVICE, "invalid pdev pointer so close pcap file device failed!");
         return -1;
     }
 
-    if (pdev->entity.pcap_file_dev_ctx->entity.file != nullptr) {
-        cleanup_pcap_plain_file_info(pdev->entity.pcap_file_dev_ctx->entity.file);
-    }
+    if (pdev->entity.pcap_file_dev_ctx != nullptr) {
+        if (pdev->entity.pcap_file_dev_ctx->entity.file != nullptr) {
+            cleanup_pcap_plain_file_info(pdev->entity.pcap_file_dev_ctx->entity.file);
+        }
 
-    if (pdev->entity.pcap_file_dev_ctx->entity.dir != nullptr) {
-        cleanup_pcap_directory_info(pdev->entity.pcap_file_dev_ctx->entity.dir);
-    }
+        if (pdev->entity.pcap_file_dev_ctx->entity.dir != nullptr) {
+            cleanup_pcap_directory_info(pdev->entity.pcap_file_dev_ctx->entity.dir);
+        }
 
-    for (uint32_t i = 0; i < PKT_QUEUE_MAX_NUM; i++) {
-        if (pdev->entity.pcap_file_dev_ctx->pkt_queues[i].len != 0) {
-            release_pio_packet_queue(&pdev->entity.pcap_file_dev_ctx->pkt_queues[i]);
+        for (uint32_t i = 0; i < PKT_QUEUE_MAX_NUM; i++) {
+            if (pdev->entity.pcap_file_dev_ctx->pkt_queues[i].len != 0) {
+                release_pio_packet_queue(&pdev->entity.pcap_file_dev_ctx->pkt_queues[i]);
+            }
         }
     }
 
@@ -341,7 +345,7 @@ void pcap_file_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_hdr, u_c
     }
 
     /* nr_rxq <= PKT_QUEUE_MAX_NUM */
-    uint16_t nr_rxq = pfile_dev_ctx->pio_dev->rxq_num;
+    uint16_t nr_rxq = pfile_dev_ctx->pdev->rxq_num;
     uint16_t rxq_id = pio_packet_hash(p) % nr_rxq;
 
     /* hash to specific queue id and enqueue */
@@ -350,8 +354,8 @@ void pcap_file_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_hdr, u_c
     pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
 }
 
-static int pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint16_t rxq_id, 
-                              struct stellar_packet **pkts, int nr_pkts) 
+static ssize_t pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id, 
+                              struct stellar_packet **pkts, size_t nr_pkts) 
 {
     if (pfile_dev_ctx->entity.file->first_pkt_hdr != nullptr) {
         pthread_mutex_lock(&pfile_dev_ctx->entity.file->handle_mutex);
@@ -365,7 +369,7 @@ static int pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx
     }
 
     int packet_q_len = nr_pkts;
-    int res = -1;
+    ssize_t res = -1;
 
     pthread_mutex_lock(&pfile_dev_ctx->entity.file->handle_mutex);
     res = pcap_dispatch(pfile_dev_ctx->entity.file->pcap_handle, packet_q_len,
@@ -380,17 +384,19 @@ static int pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx
     } else {
         // success
         struct pio_packet *p = nullptr;
-        int i = 0;
+        size_t i = 0;
+        uint32_t q_len = 0;
         pthread_mutex_lock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
         do {
             p = pio_packet_dequeue(&pfile_dev_ctx->pkt_queues[rxq_id]);
+            q_len = pfile_dev_ctx->pkt_queues[rxq_id].len;
             pkts[i] = (struct stellar_packet *)p;
             i++;
-        } while (p != nullptr && (i < nr_pkts));
+        } while ((q_len != 0) && (i < nr_pkts));
         pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
 
-        if (nullptr == p) {
-            res = i - 1;
+        if (q_len == 0) {
+            res = i;
         } else {
             res = nr_pkts;
         }
@@ -399,10 +405,10 @@ static int pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx
     return res;
 }
 
-static int pcap_directory_get_modified_time(char *pfile, struct timespec *out)
+static ssize_t pcap_directory_get_modified_time(char *pfile, struct timespec *out)
 {
     struct stat buf;
-    int ret = -1;
+    ssize_t ret = -1;
 
     if (nullptr == pfile) {
         return ret;
@@ -443,7 +449,7 @@ find_pending_file_to_add(struct pio_pcap_file_device_context *pfile_dev_ctx, str
     }
 
     struct pending_file *file_to_add = CALLOC(struct pending_file, 1);
-    int ret = strncpy_safe(file_to_add->file_name, abs_path, sizeof(file_to_add->file_name));
+    ssize_t ret = strncpy_safe(file_to_add->file_name, abs_path, sizeof(file_to_add->file_name));
     if (ret < 0) {
         log_error(ST_ERR_STR_COPY, "file_to_add file name copy failed.");
 		return nullptr;
@@ -456,7 +462,7 @@ find_pending_file_to_add(struct pio_pcap_file_device_context *pfile_dev_ctx, str
     return file_to_add;
 }
 
-static int pcap_directory_insert_file(struct pio_pcap_file_device_context *pfile_dev_ctx, struct pending_file *file_to_add)
+static ssize_t pcap_directory_insert_file(struct pio_pcap_file_device_context *pfile_dev_ctx, struct pending_file *file_to_add)
 {
     if (nullptr == pfile_dev_ctx ||  file_to_add) {
         log_error(ST_ERR_PCAP_FILE_COLLECT_FAILED, "invalid directory or file parameters.");
@@ -486,7 +492,7 @@ static int pcap_directory_insert_file(struct pio_pcap_file_device_context *pfile
     return 0;
 }
 
-static int pcap_directory_collect_pending_files(struct pio_pcap_file_device_context *pfile_dev_ctx, struct timespec *deadline)
+static ssize_t pcap_directory_collect_pending_files(struct pio_pcap_file_device_context *pfile_dev_ctx, struct timespec *deadline)
 {
     if (nullptr == pfile_dev_ctx) {
         return -1;
@@ -526,10 +532,10 @@ static int pcap_directory_collect_pending_files(struct pio_pcap_file_device_cont
     return 0;
 }
 
-static int pcap_directory_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint16_t rxq_id, 
-                                   struct stellar_packet **pkts, int nr_pkts) 
+static ssize_t pcap_directory_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id, 
+                                   struct stellar_packet **pkts, size_t nr_pkts) 
 {
-    int res = -1;
+    ssize_t res = -1;
     struct timespec deadline;
 
     memset(&deadline, 0, sizeof(struct timespec));
@@ -611,7 +617,7 @@ static int pcap_directory_dispatch(struct pio_pcap_file_device_context *pfile_de
     return res;
 }
 
-int pio_pcap_file_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts) 
+ssize_t pio_pcap_file_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts) 
 {
     struct pio_pcap_file_device_context *pfile_dev_ctx = pdev->entity.pcap_file_dev_ctx;
     if (nullptr == pfile_dev_ctx) {
@@ -619,7 +625,7 @@ int pio_pcap_file_device_receive(struct packet_io_device *pdev, uint16_t rxq_id,
         return -1;
     }
 
-    int res = -1;
+    ssize_t res = -1;
     if (pfile_dev_ctx->is_dir == 0) {
         log_info("Start reading file:%s", pfile_dev_ctx->entity.file->file_name);
         res = pcap_file_dispatch(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
@@ -631,15 +637,15 @@ int pio_pcap_file_device_receive(struct packet_io_device *pdev, uint16_t rxq_id,
     return res;
 }
 
-void pio_pcap_file_device_pkt_free(__unused struct packet_io_device *pdev, __unused uint16_t qid, struct stellar_packet **pkts, int nr_pkts) 
+void pio_pcap_file_device_pkt_free(__unused struct packet_io_device *pdev, __unused uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts) 
 {
-    for (int i = 0; i < nr_pkts; i++) {
+    for (size_t i = 0; i < nr_pkts; i++) {
         struct pio_packet *p = (struct pio_packet *)pkts[i];
         FREE(p);
     }
 }
 
-int pio_pcap_file_instance_create(struct packet_io_instance *pinst) 
+ssize_t pio_pcap_file_instance_create(struct packet_io_instance *pinst) 
 {
     if (nullptr == pinst) {
         log_error(ST_ERR_PIO_PCAP_FILE_INSTANCE, "invalid pcap file instance pointer.");
@@ -661,34 +667,29 @@ void pio_pcap_file_instance_destroy(struct packet_io_instance *pinst)
         return;
     }
 
-    FREE(pinst->entity.pcap_file_inst_ctx);
-
-    for (uint32_t i = 0; i < pinst->dev_cnt; i++) {
-        pio_pcap_file_device_close(pinst->devices[i]);
-        FREE(pinst->devices[i]);
+    if (pinst->entity.pcap_file_inst_ctx != nullptr) {
+        FREE(pinst->entity.pcap_file_inst_ctx);
     }
+
+    struct packet_io_device *node = nullptr;
+    while ((node = TAILQ_FIRST(&pinst->device_queue_head)) != nullptr) {
+		TAILQ_REMOVE(&pinst->device_queue_head, node, next);
+        pinst->dev_cnt--;
+        pio_pcap_file_device_close(node);
+		FREE(node);
+	}
 }
 
-void *pio_pcap_file_device_buff_ctrlzone(struct stellar_packet *p)
+char *pio_pcap_file_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len)
 {
     struct pio_packet *pkt = (struct pio_packet *)p;
-    return pkt->pkt_hdr;
+    *ctrlzone_len = CUSTOM_ZONE_LEN;
+    return (char *)pkt->pkt_hdr;
 }
 
-char *pio_pcap_file_device_buff_mtod(struct stellar_packet *p)
+char *pio_pcap_file_device_buff_mtod(struct stellar_packet *p, size_t *data_len)
 {   
     struct pio_packet *pkt = (struct pio_packet *)p;
+    *data_len = pkt->pkt_len;
     return (char *)pkt->pkt_payload;
-}
-
-uint32_t pio_pcap_file_device_buff_buflen(struct stellar_packet *p)
-{
-    struct pio_packet *pkt = (struct pio_packet *)p;
-    return (pkt->pkt_len + CUSTOM_ZONE_LEN);
-}
-
-uint32_t pio_pcap_file_device_buff_datalen(struct stellar_packet *p)
-{
-    struct pio_packet *pkt = (struct pio_packet *)p;
-    return (pkt->pkt_len);
-}
+}
\ No newline at end of file
diff --git a/src/packet_io/pcap_file_mode/pio_pcap_file.h b/src/packet_io/pcap_file_mode/pio_pcap_file.h
index e72781d..6bce0d9 100644
--- a/src/packet_io/pcap_file_mode/pio_pcap_file.h
+++ b/src/packet_io/pcap_file_mode/pio_pcap_file.h
@@ -21,7 +21,6 @@ extern "C"
 #include <pcap/pcap.h>
 #include <sys/queue.h>
 
-#include "global_var.h"
 #include "packet_io_util.h"
 
 struct pio_pcap_file_instance_context {
@@ -38,8 +37,8 @@ struct pcap_file_shared_info {
     /* bpf filter string, such as "tcp and port 25"*/
     char bpf_string[STR_MAX_LEN];
     
-    /* delete after the pcap file is read */
-    bool should_delete;
+    /* if delete when pcapfile is processed */
+    int should_delete;
 
     /* the timestamp of the last process */
     struct timespec last_processed_ts;
@@ -100,7 +99,7 @@ struct pio_pcap_file_device_context {
     struct pcap_file_shared_info shared;
 
     /* point to packet_io device it belongs to */
-    struct packet_io_device *pio_dev;
+    struct packet_io_device *pdev;
 };
 
 /**
@@ -109,7 +108,7 @@ struct pio_pcap_file_device_context {
  * @param pinst 
  * @return int 
  */
-int pio_pcap_file_instance_create(struct packet_io_instance *pinst);
+ssize_t pio_pcap_file_instance_create(struct packet_io_instance *pinst);
 
 /**
  * @brief 
@@ -126,24 +125,20 @@ void pio_pcap_file_instance_destroy(struct packet_io_instance *pinst);
  *        pdev->rxq_num:  number of the packet receiving queues for the device
  *        pdev->txq_num:  number of the packet sending queues for the device
  */
-int pio_pcap_file_device_open(struct packet_io_device *pdev);
+ssize_t pio_pcap_file_device_open(struct packet_io_device *pdev);
 
 /**
  * @brief close pcap_live device
  */
-int pio_pcap_file_device_close(struct packet_io_device *pdev);
+ssize_t pio_pcap_file_device_close(struct packet_io_device *pdev);
 
-int pio_pcap_file_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t pio_pcap_file_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
-void pio_pcap_file_device_pkt_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts);
+void pio_pcap_file_device_pkt_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts);
 
-void *pio_pcap_file_device_buff_ctrlzone(struct stellar_packet *p);
+char *pio_pcap_file_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len);
 
-char *pio_pcap_file_device_buff_mtod(struct stellar_packet *p);
-
-uint32_t pio_pcap_file_device_buff_buflen(struct stellar_packet *p);
-
-uint32_t pio_pcap_file_device_buff_datalen(struct stellar_packet *p);
+char *pio_pcap_file_device_buff_mtod(struct stellar_packet *p, size_t *data_len);
 
 #ifdef __cpluscplus
 }
diff --git a/src/packet_io/pcap_live_mode/pio_pcap_live.cpp b/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
index 73f6a72..0ccc804 100644
--- a/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
+++ b/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
@@ -18,11 +18,12 @@
 #include "pio_pcap_live.h"
 #include "packet_io.h"
 #include "packet_io_util.h"
+#include "packet_io_internal.h"
 
 #define DEFAULT_MAX_PACKET_SIZE 65535
 #define TIMEOUT_MS 500
 
-static int pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, const char *dev_name)
+static ssize_t pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, const char *dev_name)
 {
     if (nullptr == plive_dev_ctx) {
         return -1;
@@ -36,14 +37,14 @@ static int pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, co
         return -1;
     }
 
-    if (g_engine_instance.config.packet_io.snaplen == 0) {
+    if (g_packet_io_config.pcap.snaplen == 0) {
         plive_dev_ctx->pcap_snaplen = DEFAULT_MAX_PACKET_SIZE;
     } else {
-        plive_dev_ctx->pcap_snaplen = g_engine_instance.config.packet_io.snaplen;
+        plive_dev_ctx->pcap_snaplen = g_packet_io_config.pcap.snaplen;
     }
 
     /* set snaplen */
-    int res = pcap_set_snaplen(plive_dev_ctx->pcap_handle, plive_dev_ctx->pcap_snaplen);
+    ssize_t res = pcap_set_snaplen(plive_dev_ctx->pcap_handle, plive_dev_ctx->pcap_snaplen);
     if (res != 0) {
         log_error(ST_ERR_PCAP_SET_SNAPLEN, "could not set snaplen, error:%s", 
                   pcap_geterr(plive_dev_ctx->pcap_handle));
@@ -52,7 +53,7 @@ static int pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, co
     log_info("set snaplen to %d for %s", plive_dev_ctx->pcap_snaplen, dev_name);
 
     /* set promisc */
-    res = pcap_set_promisc(plive_dev_ctx->pcap_handle, g_engine_instance.config.packet_io.promisc);
+    res = pcap_set_promisc(plive_dev_ctx->pcap_handle, g_packet_io_config.pcap.promisc);
     if (res != 0) {
         log_error(ST_ERR_PCAP_SET_PROMISC, "could not set promisc mode, error:%s",
                   pcap_geterr(plive_dev_ctx->pcap_handle));
@@ -76,8 +77,8 @@ static int pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, co
     plive_dev_ctx->pcap_state = PCAP_STATE_UP;
 
     /* set bpf filter */
-    if (strlen(g_engine_instance.config.packet_io.bpf_string) != 0) {
-        res = strncpy_safe(plive_dev_ctx->bpf_string, g_engine_instance.config.packet_io.bpf_string, 
+    if (strlen(g_packet_io_config.pcap.bpf_string) != 0) {
+        res = strncpy_safe(plive_dev_ctx->bpf_string, g_packet_io_config.pcap.bpf_string, 
                            sizeof(plive_dev_ctx->bpf_string));
         if (res < 0) {
             log_error(ST_ERR_STR_COPY, "plive_dev_ctx bpf string copy failed.");
@@ -107,9 +108,9 @@ static int pcap_live_init(struct pio_pcap_live_device_context *plive_dev_ctx, co
     return res;
 }
 
-int pio_pcap_live_device_open(struct packet_io_device *pdev)
+ssize_t pio_pcap_live_device_open(struct packet_io_device *pdev)
 {
-    int res = -1;
+    ssize_t res = -1;
 
     if (nullptr == pdev) {
         log_error(ST_ERR_PIO_PCAP_LIVE_DEVICE, "invalid packet_io_device pointer.");
@@ -124,7 +125,7 @@ int pio_pcap_live_device_open(struct packet_io_device *pdev)
 
     pthread_mutex_init(&pdev->entity.pcap_live_dev_ctx->handle_mutex, nullptr);
 
-    pdev->entity.pcap_live_dev_ctx->pio_dev = pdev;
+    pdev->entity.pcap_live_dev_ctx->pdev = pdev;
 
     res = pcap_live_init(pdev->entity.pcap_live_dev_ctx, pdev->dev_name);
     if (res < 0) {
@@ -136,7 +137,7 @@ int pio_pcap_live_device_open(struct packet_io_device *pdev)
     return res;
 }
 
-int pio_pcap_live_device_close(struct packet_io_device *pdev)
+ssize_t pio_pcap_live_device_close(struct packet_io_device *pdev)
 {
     if (nullptr == pdev) {
         log_error(ST_ERR_PIO_PCAP_FILE_DEVICE, "invalid pdev pointer, so close pcap live device failed.");
@@ -182,7 +183,7 @@ static void pcap_live_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_h
     }
 
     /* nr_rxq <= PKT_QUEUE_MAX_NUM */
-    uint16_t nr_rxq = plive_dev_ctx->pio_dev->rxq_num;
+    uint16_t nr_rxq = plive_dev_ctx->pdev->rxq_num;
     uint16_t rxq_id = pio_packet_hash(p) % nr_rxq;
 
     /* hash to specific queue id and enqueue */
@@ -191,9 +192,9 @@ static void pcap_live_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_h
     pthread_mutex_unlock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
 }
 
-int pio_pcap_live_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts)
+ssize_t pio_pcap_live_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts)
 {
-    int res = -1;
+    ssize_t res = -1;
 
     struct pio_pcap_live_device_context *plive_dev_ctx = pdev->entity.pcap_live_dev_ctx;
     if (nullptr == plive_dev_ctx) {
@@ -201,7 +202,7 @@ int pio_pcap_live_device_receive(struct packet_io_device *pdev, uint16_t rxq_id,
         return res;
     }
 
-    int packet_q_len = nr_pkts;
+    size_t packet_q_len = nr_pkts;
     pthread_mutex_lock(&plive_dev_ctx->handle_mutex);
     res = pcap_dispatch(plive_dev_ctx->pcap_handle, packet_q_len,
                         (pcap_handler)pcap_live_pkt_callback_oneshot, (u_char *)plive_dev_ctx);
@@ -213,17 +214,19 @@ int pio_pcap_live_device_receive(struct packet_io_device *pdev, uint16_t rxq_id,
 
     } else {
         struct pio_packet *p = nullptr;
-        int i = 0;
+        size_t i = 0;
         uint32_t q_len = 0;
-        pthread_mutex_lock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
-        do {
-            p = pio_packet_dequeue(&plive_dev_ctx->pkt_queues[rxq_id]);
-            q_len = plive_dev_ctx->pkt_queues[rxq_id].len;
-            pkts[i] = (struct stellar_packet *)p;
-            printf("rxq_id:%d, i:%d, pkts[i]:%p\n", rxq_id, i, pkts[i]);
-            i++;
-        } while ((q_len != 0) && (i < nr_pkts));
-        pthread_mutex_unlock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
+
+        if (plive_dev_ctx->pkt_queues[rxq_id].len > 0) {
+            pthread_mutex_lock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
+            do {
+                p = pio_packet_dequeue(&plive_dev_ctx->pkt_queues[rxq_id]);
+                q_len = plive_dev_ctx->pkt_queues[rxq_id].len;
+                pkts[i] = (struct stellar_packet *)p;
+                i++;
+            } while ((q_len != 0) && (i < nr_pkts));
+            pthread_mutex_unlock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
+        }
 
         if (q_len == 0) {
             res = i;
@@ -235,9 +238,9 @@ int pio_pcap_live_device_receive(struct packet_io_device *pdev, uint16_t rxq_id,
     return res;
 }
 
-int pio_pcap_live_device_send(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts)
+ssize_t pio_pcap_live_device_send(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts)
 {
-    int res = -1;
+    ssize_t res = -1;
 
     struct pio_pcap_live_device_context *plive_dev_ctx = pdev->entity.pcap_live_dev_ctx;
     if (nullptr == plive_dev_ctx) {
@@ -246,7 +249,7 @@ int pio_pcap_live_device_send(struct packet_io_device *pdev, uint16_t txq_id, st
     }
 
     pthread_mutex_lock(&plive_dev_ctx->handle_mutex);
-    for (int i = 0; i < nr_pkts; i++) {
+    for (size_t i = 0; i < nr_pkts; i++) {
         struct pio_packet *p = (struct pio_packet *)pkts[i];
         res = pcap_sendpacket(plive_dev_ctx->pcap_handle, (u_char *)p->pkt_payload, p->pkt_len);
     }
@@ -256,17 +259,15 @@ int pio_pcap_live_device_send(struct packet_io_device *pdev, uint16_t txq_id, st
     return 0;
 }
 
-void pio_pcap_live_device_pkt_free(__unused struct packet_io_device *pdev, __unused uint16_t qid, struct stellar_packet **pkts, int nr_pkts)
+void pio_pcap_live_device_pkt_free(__unused struct packet_io_device *pdev, __unused uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts)
 {
     void **pptr_pkts = (void **)pkts;
-    for (int i = 0; i < nr_pkts; i++) {
-        printf("before free pptr_pkts[%d]:%p\n", i, pptr_pkts[i]);
+    for (size_t i = 0; i < nr_pkts; i++) {
         FREE(pptr_pkts[i]);
-        printf("after free pptr_pkts[%d]:%p\n", i, pptr_pkts[i]);
     }
 }
 
-int pio_pcap_live_instance_create(struct packet_io_instance *pinst)
+ssize_t pio_pcap_live_instance_create(struct packet_io_instance *pinst)
 {
     if (nullptr == pinst) {
         log_error(ST_ERR_PIO_PCAP_LIVE_INSTANCE, "invalid pcap live instance pointer.");
@@ -290,32 +291,25 @@ void pio_pcap_live_instance_destroy(struct packet_io_instance *pinst)
 
     FREE(pinst->entity.pcap_live_inst_ctx);
 
-    for (uint32_t i = 0; i < pinst->dev_cnt; i++) {
-        pio_pcap_live_device_close(pinst->devices[i]);
-        FREE(pinst->devices[i]);
-    }
+    struct packet_io_device *node = nullptr;
+    while ((node = TAILQ_FIRST(&pinst->device_queue_head)) != nullptr) {
+		TAILQ_REMOVE(&pinst->device_queue_head, node, next);
+        pinst->dev_cnt--;
+        pio_pcap_live_device_close(node);
+		FREE(node);
+	}
 }
 
-void *pio_pcap_live_device_buff_ctrlzone(struct stellar_packet *p)
+char *pio_pcap_live_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len)
 {
     struct pio_packet *pkt = (struct pio_packet *)p;
-    return pkt->pkt_hdr;
+    *ctrlzone_len = CUSTOM_ZONE_LEN;
+    return (char *)pkt->pkt_hdr;
 }
 
-char *pio_pcap_live_device_buff_mtod(struct stellar_packet *p)
+char *pio_pcap_live_device_buff_mtod(struct stellar_packet *p, size_t *data_len)
 {
     struct pio_packet *pkt = (struct pio_packet *)p;
+    *data_len = pkt->pkt_len;
     return (char *)pkt->pkt_payload;
-}
-
-uint32_t pio_pcap_live_device_buff_buflen(struct stellar_packet *p)
-{
-    struct pio_packet *pkt = (struct pio_packet *)p;
-    return (pkt->pkt_len + CUSTOM_ZONE_LEN);
-}
-
-uint32_t pio_pcap_live_device_buff_datalen(struct stellar_packet *p)
-{
-    struct pio_packet *pkt = (struct pio_packet *)p;
-    return (pkt->pkt_len);
-}
+}
\ No newline at end of file
diff --git a/src/packet_io/pcap_live_mode/pio_pcap_live.h b/src/packet_io/pcap_live_mode/pio_pcap_live.h
index 6e0e9bb..ed89e4b 100644
--- a/src/packet_io/pcap_live_mode/pio_pcap_live.h
+++ b/src/packet_io/pcap_live_mode/pio_pcap_live.h
@@ -19,7 +19,6 @@ extern "C"
 #include <stdint.h>
 #include <pcap/pcap.h>
 
-#include "global_var.h"
 #include "packet_io_util.h"
 
 #define PCAP_STATE_UP 1
@@ -59,7 +58,7 @@ struct pio_pcap_live_device_context {
     /* rx packet queue */
     struct pio_packet_queue pkt_queues[PKT_QUEUE_MAX_NUM];
 
-    struct packet_io_device *pio_dev;
+    struct packet_io_device *pdev;
 };
 
 /**
@@ -69,7 +68,7 @@ struct pio_pcap_live_device_context {
  * @param wrk_thread_num 
  * @return int 
  */
-int pio_pcap_live_instance_create(struct packet_io_instance *pinst);
+ssize_t pio_pcap_live_instance_create(struct packet_io_instance *pinst);
 
 /**
  * @brief 
@@ -86,26 +85,22 @@ void pio_pcap_live_instance_destroy(struct packet_io_instance *pinst);
  *        pdev->rxq_num:  number of the packet receiving queues for the device
  *        pdev->txq_num:  number of the packet sending queues for the device
  */
-int pio_pcap_live_device_open(struct packet_io_device *pdev);
+ssize_t pio_pcap_live_device_open(struct packet_io_device *pdev);
 
 /**
  * @brief close pcap_live device
  */
-int pio_pcap_live_device_close(struct packet_io_device *pdev);
+ssize_t pio_pcap_live_device_close(struct packet_io_device *pdev);
 
-int pio_pcap_live_device_receive(struct packet_io_device *pdev, uint16_t rxq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t pio_pcap_live_device_receive(struct packet_io_device *pdev, uint32_t rxq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
-int pio_pcap_live_device_send(struct packet_io_device *pdev, uint16_t txq_id, struct stellar_packet **pkts, int nr_pkts);
+ssize_t pio_pcap_live_device_send(struct packet_io_device *pdev, uint32_t txq_id, struct stellar_packet **pkts, size_t nr_pkts);
 
-void pio_pcap_live_device_pkt_free(struct packet_io_device *pdev, uint16_t qid, struct stellar_packet **pkts, int nr_pkts);
+void pio_pcap_live_device_pkt_free(struct packet_io_device *pdev, uint32_t qid, struct stellar_packet **pkts, size_t nr_pkts);
 
-void *pio_pcap_live_device_buff_ctrlzone(struct stellar_packet *p);
+char *pio_pcap_live_device_buff_ctrlzone(struct stellar_packet *p, size_t *ctrlzone_len);
 
-char *pio_pcap_live_device_buff_mtod(struct stellar_packet *p);
-
-uint32_t pio_pcap_live_device_buff_buflen(struct stellar_packet *p);
-
-uint32_t pio_pcap_live_device_buff_datalen(struct stellar_packet *p);
+char *pio_pcap_live_device_buff_mtod(struct stellar_packet *p, size_t *data_len);
 
 #ifdef __cpluscplus
 }
diff --git a/src/packet_io/test/CMakeLists.txt b/src/packet_io/test/CMakeLists.txt
index 949e697..e5ff651 100644
--- a/src/packet_io/test/CMakeLists.txt
+++ b/src/packet_io/test/CMakeLists.txt
@@ -8,6 +8,7 @@ target_link_libraries(
   packet_io
   dl
   pcap
+  toml
 )
 
 include(GoogleTest)
diff --git a/src/packet_io/test/gtest_packet_io.cpp b/src/packet_io/test/gtest_packet_io.cpp
index 70ccff4..97993d8 100644
--- a/src/packet_io/test/gtest_packet_io.cpp
+++ b/src/packet_io/test/gtest_packet_io.cpp
@@ -1,15 +1,275 @@
 #include <gtest/gtest.h>
 
+#include "utils.h"
+#include "packet.h"
 #include "packet_io.h"
+#include "packet_io_util.h"
 
-TEST(PACKET_IO_Test, packet_io_instance_create) {
+TEST(PACKET_IO_Test, packet_io_instance_create_and_destroy) {
+	struct packet_io_instance *ppio_inst = packet_io_instance_create(nullptr, PACKET_IO_RUN_MODE_PCAP_FILE);
+	EXPECT_EQ(ppio_inst, nullptr);
+	ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_MAX);
+  	EXPECT_EQ(ppio_inst, nullptr);
+	ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_FILE);
+	EXPECT_NE(ppio_inst, nullptr);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_Test, packet_io_device_open_and_close) {
+	struct packet_io_device *pdev = packet_io_device_open(nullptr, nullptr, 1, 1);
+	EXPECT_EQ(pdev, nullptr);
+	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_LIVE);
+	EXPECT_NE(ppio_inst, nullptr);
+	pdev = packet_io_device_open(ppio_inst, nullptr, 1, 1);
+  	EXPECT_EQ(pdev, nullptr);
+	pdev = packet_io_device_open(ppio_inst, "lo", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_Test, packet_io_device_rx) {
+	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_FILE);
+	struct packet_io_device *pdev = packet_io_device_open(ppio_inst, "./src/packet_io/test/test-64.pcapng", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	struct stellar_packet *rx_pkts[64];
+	ssize_t fetch_num = packet_io_device_rx(pdev, 0, rx_pkts, 1);
+	EXPECT_EQ(fetch_num, 1);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_Test, packet_io_device_tx) {
+	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_LIVE);
+	struct packet_io_device *pdev = packet_io_device_open(ppio_inst, "lo", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	struct stellar_packet *rx_pkts[64];
+	ssize_t send_num = packet_io_device_tx(pdev, 0, rx_pkts, 1);
+	EXPECT_EQ(send_num, 0);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_Test, packet_io_pkts_free) {
 	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_FILE);
-  	EXPECT_NE(ppio_inst, nullptr);
+	struct packet_io_device *pdev = packet_io_device_open(ppio_inst, "./src/packet_io/test/test-64.pcapng", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	struct stellar_packet *rx_pkts[64];
+	ssize_t fetch_num = packet_io_device_rx(pdev, 0, rx_pkts, 1);
+	EXPECT_EQ(fetch_num, 1);
+	packet_io_pkts_free(pdev, 0, rx_pkts, 1);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
 }
 
-TEST(PACKET_IO_Test, packet_io_open_device) {
+TEST(PACKET_IO_Test, get_stellar_packet_ctrlzone) {
 	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_FILE);
-  	EXPECT_EQ(packet_io_device_open(ppio_inst, NULL, 1, 1), nullptr);
+	struct packet_io_device *pdev = packet_io_device_open(ppio_inst, "./src/packet_io/test/test-64.pcapng", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	struct stellar_packet *rx_pkts[64];
+	ssize_t fetch_num = packet_io_device_rx(pdev, 0, rx_pkts, 1);
+	EXPECT_EQ(fetch_num, 1);
+	size_t ctrlzone_len = 0;
+	void *buff_ctrlzone = get_stellar_packet_ctrlzone(rx_pkts[0], &ctrlzone_len);
+	EXPECT_EQ(buff_ctrlzone, rx_pkts[0]);
+
+	packet_io_pkts_free(pdev, 0, rx_pkts, 1);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_Test, get_stellar_packet_data) {
+	struct packet_io_instance *ppio_inst = packet_io_instance_create("stellar", PACKET_IO_RUN_MODE_PCAP_FILE);
+	struct packet_io_device *pdev = packet_io_device_open(ppio_inst, "./src/packet_io/test/test-64.pcapng", 1, 1);
+	EXPECT_NE(pdev, nullptr);
+	struct stellar_packet *rx_pkts[64];
+	ssize_t fetch_num = packet_io_device_rx(pdev, 0, rx_pkts, 1);
+	EXPECT_EQ(fetch_num, 1);
+	size_t data_len = 0;
+	void *buff_ctrlzone = get_stellar_packet_data(rx_pkts[0], &data_len);
+	EXPECT_EQ(buff_ctrlzone, (uint8_t *)rx_pkts[0]+64);
+
+	packet_io_pkts_free(pdev, 0, rx_pkts, 1);
+	packet_io_device_close(pdev);
+	packet_io_fini(ppio_inst);
+}
+
+TEST(PACKET_IO_UTIL_Test, strncpy_safe) {
+	ssize_t res = strncpy_safe(nullptr, nullptr, 0);
+	EXPECT_EQ(res, -1);
+
+	char dst[5];
+	res = strncpy_safe(dst, "hello", sizeof(dst));
+	EXPECT_STREQ(dst, "hell");
+	EXPECT_EQ(res, 0);
+
+	memset(dst, 0, sizeof(dst));
+	res = strncpy_safe(dst, "he", sizeof(dst));
+	EXPECT_STREQ(dst, "he");
+	EXPECT_EQ(res, 0);
+}
+
+TEST(PACKET_IO_UTIL_Test, packet_copy_data) {
+	uint8_t dst[5];
+	uint8_t src[4] = {0x12, 0x34, 0x56, 0x78};
+	ssize_t res = packet_copy_data(dst, src, sizeof(src));
+	EXPECT_EQ(res, 0);
+	EXPECT_EQ(dst[0], 0x12);
+	EXPECT_EQ(dst[1], 0x34);
+	EXPECT_EQ(dst[2], 0x56);
+	EXPECT_EQ(dst[3], 0x78);
+}
+
+TEST(PACKET_IO_UTIL_Test, pio_packet_hash) {
+	struct pio_packet *p = (struct pio_packet *)malloc(MAX_SIZE_OF_PIO_PACKET);
+	memset(p, 0, MAX_SIZE_OF_PIO_PACKET);
+	uint64_t res = pio_packet_hash(p);
+	EXPECT_EQ(res, 0);
+	FREE(p);
+}
+
+TEST(PACKET_IO_UTIL_Test, pio_packet_queue_init) {
+
+}
+
+TEST(PACKET_IO_UTIL_Test, pio_packet_enqueue) {
+
+}
+
+TEST(PACKET_IO_UTIL_Test, pio_packet_dequeue) {
+
+}
+
+TEST(PACKET_IO_UTIL_Test, release_pio_packet_queue) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_instance_create) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_instance_destroy) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_open) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_close) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_receive) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_send) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_pkt_free) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_buff_ctrlzone) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_buff_mtod) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_buff_buflen) {
+
+}
+
+TEST(PACKET_IO_PIO_MARSIO_Test, pio_marsio_device_buff_datalen) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_instance_create) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_instance_destroy) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_open) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_close) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_receive) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_pkt_free) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_buff_ctrlzone) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_buff_mtod) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_buff_buflen) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_FILE_Test, pio_pcap_file_device_buff_datalen) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_instance_create) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_instance_destroy) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_open) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_close) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_receive) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_send) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_pkt_free) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_buff_ctrlzone) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_buff_mtod) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_buff_buflen) {
+
+}
+
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_buff_datalen) {
+
 }
 
 int main(int argc, char ** argv)
diff --git a/src/packet_io/test/test-64.pcapng b/src/packet_io/test/test-64.pcapng
new file mode 100644
index 0000000..eb87132
--- /dev/null
+++ b/src/packet_io/test/test-64.pcapng