diff --git a/include/common.h b/include/common.h
index 532c8ef..6e6b71c 100644
--- a/include/common.h
+++ b/include/common.h
@@ -21,4 +21,7 @@
 
 //void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug);
 
+char* show_bool(int value);
+char** command_init(char *bin);
+
 #endif
diff --git a/include/dnsproxy.h b/include/dnsproxy.h
index 286446f..484c347 100644
--- a/include/dnsproxy.h
+++ b/include/dnsproxy.h
@@ -15,4 +15,8 @@ typedef struct {
 dnsproxy* dnsproxy_init(int port);
 void dnsproxy_dump(char *caption, dnsproxy *info);
 
+void dnsproxy_add_primary(dnsproxy *info, char *server);
+void dnsproxy_add_fallback(dnsproxy *info, char *server);
+void dnsproxy_add_bootstrap(dnsproxy *info, char *server);
+
 #endif
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a2d0262..027989b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,5 +5,5 @@ include_directories(${PROJECT_SOURCE_DIR}/include/utils)
 
 add_subdirectory(utils)
 
-add_executable(cleardns cleardns.c dnsproxy.c)
+add_executable(cleardns cleardns.c dnsproxy.c common.c)
 target_link_libraries(cleardns utils)
diff --git a/src/cleardns.c b/src/cleardns.c
index 01b7c43..32a3264 100644
--- a/src/cleardns.c
+++ b/src/cleardns.c
@@ -2,6 +2,8 @@
 #include "common.h"
 #include "dnsproxy.h"
 
+#include "strList.h"
+
 //#include <stdio.h>
 //#include <string.h>
 //#include "common.h"
@@ -33,6 +35,16 @@ int main(int argc, char *argv[]) { // ClearDNS server
     log_info("ClearDNS server start (%s)", VERSION);
 
     dnsproxy *domestic = dnsproxy_init(DOMESTIC_PORT);
+
+    dnsproxy_add_bootstrap(domestic, "1.1.1.1");
+    dnsproxy_add_bootstrap(domestic, "8.8.8.8");
+
+    dnsproxy_add_primary(domestic, "223.5.5.5");
+    dnsproxy_add_primary(domestic, "tls://dns.pub");
+
+    dnsproxy_add_fallback(domestic, "tls://223.6.6.6");
+    dnsproxy_add_fallback(domestic, "tls://120.53.53.53");
+
     dnsproxy_dump("Domestic", domestic);
 
 //    int debug_mode = 0;
diff --git a/src/common.c b/src/common.c
index 0803a4e..e09e394 100644
--- a/src/common.c
+++ b/src/common.c
@@ -1,171 +1,14 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <strList.bak>
-#include "cJSON.h"
-#include "flag.h"
+#include "common.h"
+#include "strList.h"
 
-char **adguard_command = NULL;
-char **overture_command = NULL;
-char **domestic_dnsproxy_command = NULL;
-char **foreign_dnsproxy_command = NULL;
-
-void error_exit(char *message);
-char* read_file(char *file_name);
-char** command_add_field(char **command_list, char *field);
-char** dnsproxy_config(char *port, cJSON *json, int is_debug);
-void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug);
-
-void error_exit(char *message) { // exit with code 1
-    fprintf(stderr, "[ClearDNS] %s\n", message);
-    exit(EXIT_FILE_ERROR);
-}
-
-char* read_file(char *file_name) { // read file content
-    FILE *pfile = fopen(file_name, "rb");
-    if (pfile == NULL) { // open failed
-        error_exit("File open failed.");
-    }
-    fseek(pfile, 0, SEEK_END);
-    long file_length = ftell(pfile); // get file length
-    char *file_content = (char*)malloc(file_length + 1); // malloc new memory
-    if (file_content == NULL) {
-        error_exit("No enough memory."); // file too large
-    }
-    rewind(pfile);
-    fread(file_content, 1, file_length, pfile); // read file stream
-    file_content[file_length] = '\0'; // set end flag
-    fclose(pfile);
-    return file_content;
-}
-
-char** command_add_field(char **command_list, char *field) { // add field into command
-    int num = 0;
-    while(command_list[num++] != NULL); // get options number
-    command_list = (char**)realloc(command_list, sizeof(char**) * (num + 1));
-    command_list[num - 1] = strcpy((char*)malloc(strlen(field) + 1), field);
-    command_list[num] = NULL; // end sign
-    return command_list;
-}
-
-char** dnsproxy_config(char *port, cJSON *json, int is_debug) { // generate dnsproxy command
-    char *bootstrap_dns = NULL;
-    cJSON *primary_dns = NULL;
-    cJSON *fallback_dns = NULL;
-    char **command_list = (char**)malloc(sizeof(char*) * 9);
-
-    command_list[0] = "dnsproxy";
-    command_list[1] = "--port";
-    command_list[2] = port; // listen port
-    command_list[3] = "--all-servers"; // parallel queries to all servers
-    command_list[4] = "--cache"; // enable DNS cache
-    command_list[5] = "--cache-size";
-    command_list[6] = "4194304"; // cache size -> 4MiB
-    command_list[7] = "--cache-optimistic"; // optimistic DNS cache
-    command_list[8] = NULL; // end sign
-
-    while (json != NULL) {
-        if (!strcmp(json->string, "bootstrap")) { // bootstrap DNS server
-            if (!cJSON_IsString(json)) {
-                error_exit("`bootstrap` must be a string.");
-            }
-            bootstrap_dns = json->valuestring;
-        } else if (!strcmp(json->string, "primary")) { // primary DNS server
-            if (!cJSON_IsArray(json)) {
-                error_exit("`primary` must be a array.");
-            }
-            primary_dns = json->child;
-        } else if (!strcmp(json->string, "fallback")) { // fallback DNS server
-            if (!cJSON_IsArray(json)) {
-                error_exit("`fallback` must be a array.");
-            }
-            fallback_dns = json->child;
-        }
-        json = json->next; // next field
-    }
-
-    if (bootstrap_dns != NULL) { // add bootstrap DNS server
-        command_list = command_add_field(command_list, "--bootstrap");
-        command_list = command_add_field(command_list, bootstrap_dns);
-    }
-
-    if (primary_dns == NULL) { // primary DNS server required
-        error_exit("Miss primary DNS server.");
-    }
-    while (primary_dns != NULL) { // iterate over primary DNS server list
-        if (!cJSON_IsString(primary_dns)) {
-            error_exit("DNS Server should be a string.");
-        }
-        command_list = command_add_field(command_list, "--upstream");
-        command_list = command_add_field(command_list, primary_dns->valuestring);
-        primary_dns = primary_dns->next;
-    }
-
-    while (fallback_dns != NULL) { // iterate over fallback DNS server list
-        if (!cJSON_IsString(fallback_dns)) {
-            error_exit("DNS Server should be a string.");
-        }
-        command_list = command_add_field(command_list, "--fallback");
-        command_list = command_add_field(command_list, fallback_dns->valuestring);
-        fallback_dns = fallback_dns->next;
-    }
-
-    if (is_debug) { // debug mode
-        command_list = command_add_field(command_list, "--verbose");
+char* show_bool(int value) {
+    if (value) {
+        return "true";
+    } else {
+        return "false";
     }
-    return command_list;
 }
 
-void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug) {
-    // AdGuardHome command
-    adguard_command = (char**)malloc(sizeof(char*) * 7);
-    adguard_command[0] = "AdGuardHome";
-    adguard_command[1] = "-w";
-    adguard_command[2] = adguard_workdir; // workdir for AdGuardHome
-    adguard_command[3] = "-p";
-    adguard_command[4] = "80"; // port for web manage
-    adguard_command[5] = "--no-check-update"; // skip check update (invalid in docker)
-    adguard_command[6] = NULL; // end sign
-    if (is_debug) { // debug mode
-        adguard_command = command_add_field(adguard_command, "--verbose");
-    }
-
-    // overture command
-    overture_command = (char**)malloc(sizeof(char*) * 4);
-    overture_command[0] = "overture";
-    overture_command[1] = "-c";
-    overture_command[2] = overture_config;
-    overture_command[3] = NULL; // end sign
-    if (is_debug) { // debug mode
-        overture_command = command_add_field(overture_command, "-v");
-    }
-
-    // dnsproxy command
-    cJSON *json = NULL;
-    cJSON *json_root = cJSON_Parse(read_file(upstream_config));
-    if (json_root == NULL) {
-        error_exit("JSON format error.");
-    } else {
-        json = json_root->child;
-    }
-    while (json != NULL) {
-        if (!strcmp(json->string, "domestic")) { // domestic dnsproxy config
-            if (!cJSON_IsObject(json)) {
-                error_exit("`domestic` must be a object.");
-            }
-            domestic_dnsproxy_command = dnsproxy_config("4053", json->child, is_debug);
-        } else if (!strcmp(json->string, "foreign")) { // foreign dnsproxy config
-            if (!cJSON_IsObject(json)) {
-                error_exit("`foreign` must be a object.");
-            }
-            foreign_dnsproxy_command = dnsproxy_config("6053", json->child, is_debug);
-        }
-        json = json->next; // next field
-    }
-    if (domestic_dnsproxy_command == NULL) {
-        error_exit("Miss domestic DNS settings.");
-    }
-    if (foreign_dnsproxy_command == NULL) {
-        error_exit("Miss foreign DNS settings.");
-    }
-    cJSON_free(json_root); // free cJSON object
+char** command_init(char *bin) {
+    return string_list_append(string_list_init(), bin);
 }
diff --git a/src/common_legacy.c b/src/common_legacy.c
new file mode 100644
index 0000000..0803a4e
--- /dev/null
+++ b/src/common_legacy.c
@@ -0,0 +1,171 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <strList.bak>
+#include "cJSON.h"
+#include "flag.h"
+
+char **adguard_command = NULL;
+char **overture_command = NULL;
+char **domestic_dnsproxy_command = NULL;
+char **foreign_dnsproxy_command = NULL;
+
+void error_exit(char *message);
+char* read_file(char *file_name);
+char** command_add_field(char **command_list, char *field);
+char** dnsproxy_config(char *port, cJSON *json, int is_debug);
+void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug);
+
+void error_exit(char *message) { // exit with code 1
+    fprintf(stderr, "[ClearDNS] %s\n", message);
+    exit(EXIT_FILE_ERROR);
+}
+
+char* read_file(char *file_name) { // read file content
+    FILE *pfile = fopen(file_name, "rb");
+    if (pfile == NULL) { // open failed
+        error_exit("File open failed.");
+    }
+    fseek(pfile, 0, SEEK_END);
+    long file_length = ftell(pfile); // get file length
+    char *file_content = (char*)malloc(file_length + 1); // malloc new memory
+    if (file_content == NULL) {
+        error_exit("No enough memory."); // file too large
+    }
+    rewind(pfile);
+    fread(file_content, 1, file_length, pfile); // read file stream
+    file_content[file_length] = '\0'; // set end flag
+    fclose(pfile);
+    return file_content;
+}
+
+char** command_add_field(char **command_list, char *field) { // add field into command
+    int num = 0;
+    while(command_list[num++] != NULL); // get options number
+    command_list = (char**)realloc(command_list, sizeof(char**) * (num + 1));
+    command_list[num - 1] = strcpy((char*)malloc(strlen(field) + 1), field);
+    command_list[num] = NULL; // end sign
+    return command_list;
+}
+
+char** dnsproxy_config(char *port, cJSON *json, int is_debug) { // generate dnsproxy command
+    char *bootstrap_dns = NULL;
+    cJSON *primary_dns = NULL;
+    cJSON *fallback_dns = NULL;
+    char **command_list = (char**)malloc(sizeof(char*) * 9);
+
+    command_list[0] = "dnsproxy";
+    command_list[1] = "--port";
+    command_list[2] = port; // listen port
+    command_list[3] = "--all-servers"; // parallel queries to all servers
+    command_list[4] = "--cache"; // enable DNS cache
+    command_list[5] = "--cache-size";
+    command_list[6] = "4194304"; // cache size -> 4MiB
+    command_list[7] = "--cache-optimistic"; // optimistic DNS cache
+    command_list[8] = NULL; // end sign
+
+    while (json != NULL) {
+        if (!strcmp(json->string, "bootstrap")) { // bootstrap DNS server
+            if (!cJSON_IsString(json)) {
+                error_exit("`bootstrap` must be a string.");
+            }
+            bootstrap_dns = json->valuestring;
+        } else if (!strcmp(json->string, "primary")) { // primary DNS server
+            if (!cJSON_IsArray(json)) {
+                error_exit("`primary` must be a array.");
+            }
+            primary_dns = json->child;
+        } else if (!strcmp(json->string, "fallback")) { // fallback DNS server
+            if (!cJSON_IsArray(json)) {
+                error_exit("`fallback` must be a array.");
+            }
+            fallback_dns = json->child;
+        }
+        json = json->next; // next field
+    }
+
+    if (bootstrap_dns != NULL) { // add bootstrap DNS server
+        command_list = command_add_field(command_list, "--bootstrap");
+        command_list = command_add_field(command_list, bootstrap_dns);
+    }
+
+    if (primary_dns == NULL) { // primary DNS server required
+        error_exit("Miss primary DNS server.");
+    }
+    while (primary_dns != NULL) { // iterate over primary DNS server list
+        if (!cJSON_IsString(primary_dns)) {
+            error_exit("DNS Server should be a string.");
+        }
+        command_list = command_add_field(command_list, "--upstream");
+        command_list = command_add_field(command_list, primary_dns->valuestring);
+        primary_dns = primary_dns->next;
+    }
+
+    while (fallback_dns != NULL) { // iterate over fallback DNS server list
+        if (!cJSON_IsString(fallback_dns)) {
+            error_exit("DNS Server should be a string.");
+        }
+        command_list = command_add_field(command_list, "--fallback");
+        command_list = command_add_field(command_list, fallback_dns->valuestring);
+        fallback_dns = fallback_dns->next;
+    }
+
+    if (is_debug) { // debug mode
+        command_list = command_add_field(command_list, "--verbose");
+    }
+    return command_list;
+}
+
+void load_start_command(char *adguard_workdir, char *overture_config, char *upstream_config, int is_debug) {
+    // AdGuardHome command
+    adguard_command = (char**)malloc(sizeof(char*) * 7);
+    adguard_command[0] = "AdGuardHome";
+    adguard_command[1] = "-w";
+    adguard_command[2] = adguard_workdir; // workdir for AdGuardHome
+    adguard_command[3] = "-p";
+    adguard_command[4] = "80"; // port for web manage
+    adguard_command[5] = "--no-check-update"; // skip check update (invalid in docker)
+    adguard_command[6] = NULL; // end sign
+    if (is_debug) { // debug mode
+        adguard_command = command_add_field(adguard_command, "--verbose");
+    }
+
+    // overture command
+    overture_command = (char**)malloc(sizeof(char*) * 4);
+    overture_command[0] = "overture";
+    overture_command[1] = "-c";
+    overture_command[2] = overture_config;
+    overture_command[3] = NULL; // end sign
+    if (is_debug) { // debug mode
+        overture_command = command_add_field(overture_command, "-v");
+    }
+
+    // dnsproxy command
+    cJSON *json = NULL;
+    cJSON *json_root = cJSON_Parse(read_file(upstream_config));
+    if (json_root == NULL) {
+        error_exit("JSON format error.");
+    } else {
+        json = json_root->child;
+    }
+    while (json != NULL) {
+        if (!strcmp(json->string, "domestic")) { // domestic dnsproxy config
+            if (!cJSON_IsObject(json)) {
+                error_exit("`domestic` must be a object.");
+            }
+            domestic_dnsproxy_command = dnsproxy_config("4053", json->child, is_debug);
+        } else if (!strcmp(json->string, "foreign")) { // foreign dnsproxy config
+            if (!cJSON_IsObject(json)) {
+                error_exit("`foreign` must be a object.");
+            }
+            foreign_dnsproxy_command = dnsproxy_config("6053", json->child, is_debug);
+        }
+        json = json->next; // next field
+    }
+    if (domestic_dnsproxy_command == NULL) {
+        error_exit("Miss domestic DNS settings.");
+    }
+    if (foreign_dnsproxy_command == NULL) {
+        error_exit("Miss foreign DNS settings.");
+    }
+    cJSON_free(json_root); // free cJSON object
+}
diff --git a/src/dnsproxy.c b/src/dnsproxy.c
index e4b9fdd..fefcf2a 100644
--- a/src/dnsproxy.c
+++ b/src/dnsproxy.c
@@ -4,18 +4,6 @@
 #include "common.h"
 #include "strList.h"
 
-char* show_bool(int value) {
-    if (value) {
-        return "true";
-    } else {
-        return "false";
-    }
-}
-
-char** command_init(char *file) {
-    return string_list_append(string_list_init(), file);
-}
-
 dnsproxy* dnsproxy_init(int port) {
     dnsproxy *info = (dnsproxy*)malloc(sizeof(dnsproxy));
     info->port = port;
@@ -34,21 +22,20 @@ void dnsproxy_dump(char *caption, dnsproxy *info) {
     log_debug("%s verify -> %s", caption, show_bool(info->verify));
     log_debug("%s parallel -> %s", caption, show_bool(info->parallel));
     log_debug("%s optimistic -> %s", caption, show_bool(info->optimistic));
-
     log_debug("%s bootstrap -> %s", caption, string_list_dump(info->bootstrap));
     log_debug("%s fallback -> %s", caption, string_list_dump(info->fallback));
     log_debug("%s primary -> %s", caption, string_list_dump(info->primary));
-
     log_debug("%s cache -> %s", caption, info->cache);
+}
 
-    char **test = string_list_init();
-    test = string_list_append(test, "0");
-    test = string_list_append(test, "1");
-    test = string_list_append(test, "2");
+void dnsproxy_add_primary(dnsproxy *info, char *server) {
+    info->primary = string_list_append(info->primary, server);
+}
 
-//    char *test[] = {NULL};
-//    char *test[] = {"dnomd343", "2333", NULL};
-    log_warn("%s", string_list_dump(test));
-    log_warn("%d", string_list_len(test));
+void dnsproxy_add_fallback(dnsproxy *info, char *server) {
+    info->fallback = string_list_append(info->fallback, server);
+}
 
+void dnsproxy_add_bootstrap(dnsproxy *info, char *server) {
+    info->bootstrap = string_list_append(info->bootstrap, server);
 }