diff --git a/default.config b/default.config
index 10057eb..f443241 100644
--- a/default.config
+++ b/default.config
@@ -68,7 +68,7 @@ case "$TASK" in
         ;;
     # creates executable with debug info and no optimizations
     build_exec_dbg)
-        C_ARGS="-O0 -g3"
+        C_ARGS="-O0 -g3 -DDEBUG"
         CPP_ARGS="$C_ARGS"
         LINKER_ARGS="$CPP_ARGS $LINKER_LIBS"
         PRE_TASK_SCRIPT=
diff --git a/src/Connectors.c b/src/Connectors.c
new file mode 100644
index 0000000..e949772
--- /dev/null
+++ b/src/Connectors.c
@@ -0,0 +1,67 @@
+#include "port-tunnel.h"
+
+////////////////////////////////////////
+//            ConnectorUDP            //
+////////////////////////////////////////
+
+void ConnectorUDP_construct(ConnectorUDP* ptr, knIPV4Endpoint listener_end, knIPV4Endpoint connector_end, OutputMode out_mode){
+    __PipeStorage_construct(&ptr->pipes);
+
+    if(out_mode == OutputMode_Bind){
+        tryLast(knSocketUDP_open(true), m_s, ;);
+        ptr->main_sock = m_s.value.VoidPtr;
+        tryLast(knSocketUDP_bind(ptr->main_sock, connector_end), _m7u7, ;);
+    }
+    else if(out_mode == OutputMode_Send){
+        tryLast(knSocketUDP_open(false), m_s, ;);
+        ptr->main_sock = m_s.value.VoidPtr;
+    }
+    else throw("no output mode has been selected");
+
+    ptr->listener_end = listener_end;
+    ptr->connector_end = connector_end;
+    ptr->out_mode = out_mode;
+}
+
+void ConnectorUDP_destruct(ConnectorUDP* ptr){
+    __PipeStorage_destruct(&ptr->pipes);
+    tryLast(knSocketUDP_close(ptr->main_sock), _m864, ;);
+}
+
+void ConnectorUDP_start(ConnectorUDP* ptr){
+    __PipeStorage_startGCAsync(&ptr->pipes);
+
+}
+
+////////////////////////////////////////
+//            ConnectorTCP            //
+////////////////////////////////////////
+
+void ConnectorTCP_construct(ConnectorTCP* ptr, knIPV4Endpoint listener_end, knIPV4Endpoint connector_end, OutputMode out_mode){
+    __PipeStorage_construct(&ptr->pipes);
+    
+    if(out_mode == OutputMode_Bind){
+        tryLast(knSocketTCP_open(true), m_s, ;);
+        ptr->main_sock = m_s.value.VoidPtr;
+        tryLast(knSocketTCP_bindAndListen(ptr->main_sock, connector_end), _m7u7, ;);
+    }
+    else if(out_mode == OutputMode_Send){
+        tryLast(knSocketTCP_open(false), m_s, ;);
+        ptr->main_sock = m_s.value.VoidPtr;
+    }
+    else throw("no output mode has been selected");
+
+    ptr->listener_end = listener_end;
+    ptr->connector_end = connector_end;
+    ptr->out_mode = out_mode;
+}
+
+void ConnectorTCP_destruct(ConnectorTCP* ptr){
+    __PipeStorage_destruct(&ptr->pipes);
+    tryLast(knSocketTCP_close(ptr->main_sock), _m864, ;);
+}
+
+void ConnectorTCP_start(ConnectorTCP* ptr){
+    __PipeStorage_startGCAsync(&ptr->pipes);
+
+}
diff --git a/src/Listeners.c b/src/Listeners.c
new file mode 100644
index 0000000..a6dddc4
--- /dev/null
+++ b/src/Listeners.c
@@ -0,0 +1,43 @@
+#include "port-tunnel.h"
+
+////////////////////////////////////////
+//            ListenerUDP             //
+////////////////////////////////////////
+
+void ListenerUDP_construct(ListenerUDP* ptr, knIPV4Endpoint listener_end){
+    __PipeStorage_construct(&ptr->pipes);
+    tryLast(knSocketUDP_open(true), m_s, ;);
+    ptr->main_sock = m_s.value.VoidPtr;
+    tryLast(knSocketUDP_bind(ptr->main_sock, listener_end), _m7u7, ;);
+    ptr->connector_end = knIPV4Endpoint_INVALID;
+}
+
+void ListenerUDP_start(ListenerUDP* ptr){
+
+}
+
+void ListenerUDP_destruct(ListenerUDP* ptr){
+    __PipeStorage_destruct(&ptr->pipes);
+    tryLast(knSocketUDP_close(ptr->main_sock), _m864, ;);
+}
+
+////////////////////////////////////////
+//            ListenerTCP             //
+////////////////////////////////////////
+
+void ListenerTCP_construct(ListenerTCP* ptr, knIPV4Endpoint listener_end){
+    __PipeStorage_construct(&ptr->pipes);
+    tryLast(knSocketTCP_open(true), m_s, ;);
+    ptr->main_sock = m_s.value.VoidPtr;
+    tryLast(knSocketTCP_bindAndListen(ptr->main_sock, listener_end), _m7u7, ;);
+    ptr->connector_end = knIPV4Endpoint_INVALID;
+}
+
+void ListenerTCP_destruct(ListenerTCP* ptr){
+    __PipeStorage_destruct(&ptr->pipes);
+    tryLast(knSocketTCP_close(ptr->main_sock), _m864, ;);
+}
+
+void ListenerTCP_start(ListenerTCP* ptr){
+    
+}
diff --git a/src/PipeStorage.c b/src/PipeStorage.c
new file mode 100644
index 0000000..4b979a0
--- /dev/null
+++ b/src/PipeStorage.c
@@ -0,0 +1,22 @@
+#include "port-tunnel.h"
+
+
+void __PipeStorage_construct(PipeStorage* s){
+    s->is_gc_stopped = true;
+    s->last_check_time = 0;
+    s->table = Hashtable_create();
+}
+
+void __PipeStorage_destruct(PipeStorage* s){
+    __PipeStorage_stopGCAsync(s);
+    Hashtable_free(s->table);
+}
+
+void __PipeStorage_startGCAsync(PipeStorage* s){
+
+}
+
+void __PipeStorage_stopGCAsync(PipeStorage* s){
+    s->is_gc_stopped = true;
+    s->last_check_time = 0;
+}
diff --git a/src/Pipes.c b/src/Pipes.c
new file mode 100644
index 0000000..b331ed7
--- /dev/null
+++ b/src/Pipes.c
@@ -0,0 +1,65 @@
+#include "port-tunnel.h"
+
+////////////////////////////////////////
+//              PipeBase              //
+////////////////////////////////////////
+
+static void PipeBase_construct(PipeBase* pipe){
+    pipe->is_closed = false;
+    pipe->is_transmitting = false;
+    pipe->last_transmit_time = getTimeUsec();
+}
+
+////////////////////////////////////////
+//              PipeUDP               //
+////////////////////////////////////////
+
+void PipeUDP_construct(PipeUDP* pipe, knSocketUDP* pipe_in_sock, knIPV4Endpoint pipe_out_end){
+    PipeBase_construct(&pipe->base);
+    pipe->pipe_in_sock = pipe_in_sock;
+    pipe->pipe_out_end = pipe_out_end;
+}
+
+void PipeUDP_destruct(PipeUDP* pipe){
+    Maybe m = knSocketUDP_shutdown(pipe->pipe_in_sock, knShutdownType_Both);
+    if(m.errmsg)
+        logError("%s", m.errmsg);
+    m = knSocketUDP_close(pipe->pipe_in_sock);
+    if(m.errmsg)
+        logError("%s", m.errmsg);
+}
+
+void PipeUDP_startAsync(PipeUDP* pipe){
+
+}
+
+void PipeUDP_stop(PipeUDP* pipe){
+
+}
+
+////////////////////////////////////////
+//              PipeTCP               //
+////////////////////////////////////////
+
+void PipeTCP_construct(PipeTCP* pipe, knSocketTCP* pipe_in_sock, knIPV4Endpoint pipe_out_end){
+    PipeBase_construct(&pipe->base);
+    pipe->pipe_in_sock = pipe_in_sock;
+    pipe->pipe_out_end = pipe_out_end;
+}
+
+void PipeTCP_destruct(PipeTCP* pipe){
+    Maybe m = knSocketTCP_shutdown(pipe->pipe_in_sock, knShutdownType_Both);
+    if(m.errmsg)
+        logError("%s", m.errmsg);
+    m = knSocketTCP_close(pipe->pipe_in_sock);
+    if(m.errmsg)
+        logError("%s", m.errmsg);
+}
+
+void PipeTCP_startAsync(PipeTCP* pipe){
+
+}
+
+void PipeTCP_stop(PipeTCP* pipe){
+    
+}
diff --git a/src/help_message.c b/src/help_message.c
index a5f7316..e76d148 100644
--- a/src/help_message.c
+++ b/src/help_message.c
@@ -2,19 +2,25 @@
 
 // option help definition
 #define HELP_OPT(ALIASES, PARAMS, DESCRIPTION...) \
-    FWHI "    " ALIASES " " PARAMS FGRY "\n" DESCRIPTION
+    FWHI"    " ALIASES " " PARAMS FGRY "\n" DESCRIPTION
 
 // option parameter help definition
 #define HELP_PRM(PNAME) \
-    FWHI "[" FCYN PNAME FWHI "]"
+    FWHI"[" FCYN PNAME FWHI"]"
 
 // option nullable parameter help definition
 #define HELP_PRMN(PNAME) \
-    FWHI "[" FCYN PNAME FWHI "?]"
+    FWHI"[" FCYN PNAME FWHI"?]"
 
 // option parameter1/parameter2 help definition
 #define HELP_PRM2(PNAME1, PNAME2) \
-    FWHI "[" FCYN PNAME1 FWHI "/" FCYN PNAME2 FWHI "]"
+    FWHI"[" FCYN PNAME1 FWHI"/" FCYN PNAME2 FWHI"]"
+
+#define HELP_PRM3(PNAME1, PNAME2, PNAME3) \
+    FWHI"[" FCYN PNAME1 FWHI"/" FCYN PNAME2 FWHI"/" FCYN PNAME3 FWHI"]"
+
+#define HELP_PRM4(PNAME1, PNAME2, PNAME3, PNAME4) \
+    FWHI"[" FCYN PNAME1 FWHI"/" FCYN PNAME2 FWHI"/" FCYN PNAME3 FWHI"/" FCYN PNAME4 FWHI"]"
 
 const char* help_message = (
     FWHI"Usage: port-tunnel " 
@@ -72,4 +78,8 @@ const char* help_message = (
     HELP_OPT("-e, --encrypt",
         HELP_PRM("key"),
         "      Encrypt outgoing packets with a key.\n")
+
+    HELP_OPT("-v, --verbosity, --log-level",
+        HELP_PRM4("debug", "info", "warning", "error"),
+        "      Sets log verbocity level (default=info).\n")
 );
diff --git a/src/main.c b/src/main.c
deleted file mode 100644
index fc8b350..0000000
--- a/src/main.c
+++ /dev/null
@@ -1,153 +0,0 @@
-#include "../kerep/src/base/base.h"
-#include "../kerep/src/Network/network.h"
-
-extern const char* help_message;
-
-int errs(char* err_msg){
-    throw(err_msg);
-    return -1;
-}
-
-#define argIs(STR) cptr_equals(arg, STR)
-
-#define argNext() argv[++argi < argc ? argi : errs(cptr_concat("option '",arg,"' must have a parameter"))]
-
-typedef enum {
-    TunnelProtocol_None,
-    TunnelProtocol_TCP,
-    TunnelProtocol_UDP
-} TunnelProtocol;
-
-typedef enum {
-    InputMode_None,
-    InputMode_Listen,
-    InputMode_Connect
-} InputMode;
-
-typedef enum {
-    OutputMode_None,
-    OutputMode_Bind,
-    OutputMode_Send
-} OutputMode;
-
-int main(int argc, const char* const* argv){
-    kt_beginInit(false);
-    kt_initKerepTypes();
-    // kt_register(...);
-    kt_endInit();
-
-    TunnelProtocol tunnel_protocol = TunnelProtocol_None;
-    InputMode input_mode = InputMode_None;
-    OutputMode output_mode = OutputMode_None;
-    knIPV4Endpoint input_end = knIPV4Endpoint_INVALID;
-    knIPV4Endpoint output_end = knIPV4Endpoint_INVALID;
-    const char* encryption_key = NULL;
-    const char* decryption_key = NULL;
-
-    if(argc < 2)
-        throw("No arguments provided. Run the program with argument -h to see help message");
-
-    for(int argi = 1; argi < argc; argi++){
-        const char* arg = argv[argi];
-        if(argIs("-h") || argIs("--help") || argIs("/?")){
-            kprintf("%s"FGRY"\n", help_message);
-            return 0;
-        }
-        else if(argIs("-p") || argIs("--protocol")){
-            if(tunnel_protocol != TunnelProtocol_None)
-                throw(cptr_concat("invalid option '",arg,"': tunnel protocol has been set already"));
-            
-            const char* protocol_str = argNext();
-            char* protocol_str_lower = cptr_toLower(protocol_str);
-            if(cptr_equals(protocol_str_lower, "tcp"))
-                tunnel_protocol = TunnelProtocol_TCP;
-            else if(cptr_equals(protocol_str_lower, "udp"))
-                tunnel_protocol = TunnelProtocol_UDP;
-            else throw(cptr_concat("invalid parameter '",protocol_str,"': unknown protocol"));
-            free(protocol_str_lower);
-        }
-        else if(argIs("-l") || argIs("--listen")){
-            if(input_mode != InputMode_None)
-                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
-            
-            input_mode = InputMode_Listen;
-            const char* input_end_str = argNext();
-            tryLast(knIPV4Endpoint_fromStr(input_end_str, &input_end), _m8612, ;);
-        }
-        else if(argIs("-c") || argIs("--connect")){
-            if(input_mode != InputMode_None)
-                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
-            
-            input_mode = InputMode_Connect;
-            const char* input_end_str = argNext();
-            tryLast(knIPV4Endpoint_fromStr(input_end_str, &input_end), _m2612, ;);
-        }
-        else if(argIs("-s") || argIs("--send-to")){
-            if(output_mode != OutputMode_None)
-                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
-            if(input_mode != InputMode_Connect)
-                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
-            
-            output_mode = OutputMode_Send;
-            const char* output_end_str = argNext();
-            tryLast(knIPV4Endpoint_fromStr(output_end_str, &output_end), _m8613, ;);
-        }
-        else if(argIs("-b") || argIs("--bind-to")){
-            if(output_mode != OutputMode_None)
-                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
-            if(input_mode != InputMode_Connect)
-                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
-            
-            output_mode = OutputMode_Bind;
-            const char* output_end_str = argNext();
-            tryLast(knIPV4Endpoint_fromStr(output_end_str, &output_end), _m2613, ;);
-        }
-        else if(argIs("-e") || argIs("--encrypt")){
-            if(encryption_key != NULL)
-                throw(cptr_concat("invalid option '",arg,"': encryption key has been set already"));
-            
-            encryption_key = argNext();
-            if(cptr_length(encryption_key) < 16)
-                throw("too short encryption key (min length 16)");
-            if(cptr_length(encryption_key) > 512)
-                throw("too long encryption key (max length 512)");
-        }
-        else if(argIs("-d") || argIs("--decrypt")){
-            if(decryption_key != NULL)
-                throw(cptr_concat("invalid option '",arg,"': decryption key has been set already"));
-            
-            decryption_key = argNext();
-            if(cptr_length(decryption_key) < 16)
-                throw("too short decryption key (min length 16)");
-            if(cptr_length(decryption_key) > 512)
-                throw("too long decryption key (max length 512)");
-        }
-        else {
-            throw(cptr_concat("invalid argument: ", arg));
-        }
-    }
-
-    kprintf("tunnel_protocol: %i\n", tunnel_protocol);
-    kprintf("input_mode: %i\n", input_mode);
-    kprintf("output_mode: %i\n", output_mode);
-
-    char* temps;
-    if(!knIPV4Endpoint_isINVALID(input_end)){
-        temps = knIPV4Endpoint_toString(&input_end);
-        kprintf("input_end: %s\n", temps);
-        free(temps);
-    }
-    else kprintf("input_end: INVALID\n");
-
-    if(!knIPV4Endpoint_isINVALID(output_end)){
-        temps = knIPV4Endpoint_toString(&output_end);
-        kprintf("output_end: %s\n", temps);
-        free(temps);
-    }
-    else kprintf("output_end: INVALID\n");
-
-    kprintf("encryption_key: %s\n", encryption_key ? encryption_key : "NULL");
-    kprintf("decryption_key: %s\n", decryption_key ? decryption_key : "NULL");
-
-    return 0;
-}
diff --git a/src/port-tunnel.c b/src/port-tunnel.c
new file mode 100644
index 0000000..1d726ee
--- /dev/null
+++ b/src/port-tunnel.c
@@ -0,0 +1,213 @@
+#include "port-tunnel.h"
+
+kt_define(PipeBase, NULL, NULL)
+kt_define(PipeUDP, (freeMembers_t)PipeUDP_destruct, NULL)
+kt_define(PipeTCP, (freeMembers_t)PipeTCP_destruct, NULL)
+kt_define(PipeStorage, (freeMembers_t)__PipeStorage_destruct, NULL)
+kt_define(ListenerUDP, (freeMembers_t)ListenerUDP_destruct, NULL)
+kt_define(ListenerTCP, (freeMembers_t)ListenerTCP_destruct, NULL)
+kt_define(ConnectorUDP, (freeMembers_t)ConnectorUDP_destruct, NULL)
+kt_define(ConnectorTCP, (freeMembers_t)ConnectorTCP_destruct, NULL)
+
+LogLevel _log_level = LogLevel_Info;
+
+int errs(char* err_msg){
+    throw(err_msg);
+    return -1;
+}
+
+#define argIs(STR) cptr_equals(arg, STR)
+
+#define argNext() argv[++argi < argc ? argi : errs(cptr_concat("option '",arg,"' must have a parameter"))]
+
+int main(int argc, const char* const* argv){
+#ifdef DEBUG
+    kt_beginInit(true);
+#else
+    kt_beginInit(false);
+#endif
+    kt_initKerepTypes();
+    kt_register(PipeBase);
+    kt_register(PipeUDP);
+    kt_register(PipeTCP);
+    kt_register(PipeStorage);
+    kt_register(ListenerUDP);
+    kt_register(ListenerTCP);
+    kt_register(ConnectorUDP);
+    kt_register(ConnectorTCP);
+    kt_endInit();
+
+    tryLast(kn_tryInit(), _m11257, ;)
+
+    TunnelProtocol tunnel_protocol = TunnelProtocol_None;
+    InputMode input_mode = InputMode_None;
+    OutputMode output_mode = OutputMode_None;
+    knIPV4Endpoint listener_end = knIPV4Endpoint_INVALID;
+    knIPV4Endpoint connector_end = knIPV4Endpoint_INVALID;
+    const char* encryption_key = NULL;
+    const char* decryption_key = NULL;
+
+    LogLevel log_level =
+#ifdef DEBUG
+        LogLevel_Debug;
+#else
+        LogLevel_Info;
+#endif
+
+    // parse args
+    if(argc < 2)
+        throw("No arguments provided. Run the program with argument -h to see help message");
+
+    for(int argi = 1; argi < argc; argi++){
+        const char* arg = argv[argi];
+        if(argIs("-h") || argIs("--help") || argIs("/?")){
+            kprintf("%s"FGRY"", help_message);
+            return 0;
+        }
+        else if(argIs("-p") || argIs("--protocol")){
+            if(tunnel_protocol != TunnelProtocol_None)
+                throw(cptr_concat("invalid option '",arg,"': tunnel protocol has been set already"));
+            
+            const char* protocol_str = argNext();
+            char* protocol_str_lower = cptr_toLower(protocol_str);
+            if(cptr_equals(protocol_str_lower, "tcp"))
+                tunnel_protocol = TunnelProtocol_TCP;
+            else if(cptr_equals(protocol_str_lower, "udp"))
+                tunnel_protocol = TunnelProtocol_UDP;
+            else throw(cptr_concat("invalid parameter '",protocol_str,"': unknown protocol"));
+            free(protocol_str_lower);
+        }
+        else if(argIs("-l") || argIs("--listen")){
+            if(input_mode != InputMode_None)
+                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
+            
+            input_mode = InputMode_Listen;
+            const char* input_end_str = argNext();
+            tryLast(knIPV4Endpoint_fromStr(input_end_str, &listener_end), _m8612, ;);
+        }
+        else if(argIs("-c") || argIs("--connect")){
+            if(input_mode != InputMode_None)
+                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
+            
+            input_mode = InputMode_Connect;
+            const char* input_end_str = argNext();
+            tryLast(knIPV4Endpoint_fromStr(input_end_str, &listener_end), _m2612, ;);
+        }
+        else if(argIs("-s") || argIs("--send-to")){
+            if(output_mode != OutputMode_None)
+                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
+            if(input_mode != InputMode_Connect)
+                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
+            
+            output_mode = OutputMode_Send;
+            const char* output_end_str = argNext();
+            tryLast(knIPV4Endpoint_fromStr(output_end_str, &connector_end), _m8613, ;);
+        }
+        else if(argIs("-b") || argIs("--bind-to")){
+            if(output_mode != OutputMode_None)
+                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
+            if(input_mode != InputMode_Connect)
+                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
+            
+            output_mode = OutputMode_Bind;
+            const char* output_end_str = argNext();
+            tryLast(knIPV4Endpoint_fromStr(output_end_str, &connector_end), _m2613, ;);
+        }
+        else if(argIs("-e") || argIs("--encrypt")){
+            if(encryption_key != NULL)
+                throw(cptr_concat("invalid option '",arg,"': encryption key has been set already"));
+            
+            encryption_key = argNext();
+            if(cptr_length(encryption_key) < 16)
+                throw("too short encryption key (min length 16)");
+            if(cptr_length(encryption_key) > 512)
+                throw("too long encryption key (max length 512)");
+        }
+        else if(argIs("-d") || argIs("--decrypt")){
+            if(decryption_key != NULL)
+                throw(cptr_concat("invalid option '",arg,"': decryption key has been set already"));
+            
+            decryption_key = argNext();
+            if(cptr_length(decryption_key) < 16)
+                throw("too short decryption key (min length 16)");
+            if(cptr_length(decryption_key) > 512)
+                throw("too long decryption key (max length 512)");
+        }
+        else if(argIs("-v") || argIs("--verbosity") || argIs("--log-level")){
+            char* log_level_str = argNext();
+            char* opt = cptr_toLower(log_level_str);
+            if(cptr_equals(opt, "debug"))
+                log_level = LogLevel_Debug;
+            else if(cptr_equals(opt, "info"))
+                log_level = LogLevel_Info;
+            else if(cptr_equals(opt, "warning"))
+                log_level = LogLevel_Warning;
+            else if(cptr_equals(opt, "error"))
+                log_level = LogLevel_Error;
+            else throw(cptr_concat("invalid parameter '",log_level_str,"': unknown log_level"));
+            free(opt);
+        }
+        else {
+            throw(cptr_concat("invalid argument: ", arg));
+        }
+    }
+
+    setLogLevel(log_level);
+
+    // print parsed args
+    logDebug("tunnel_protocol: %i", tunnel_protocol);
+    logDebug("input_mode: %i", input_mode);
+    logDebug("output_mode: %i", output_mode);
+    char* temps;
+    if(!knIPV4Endpoint_isINVALID(listener_end)){
+        temps = knIPV4Endpoint_toString(&listener_end);
+        logDebug("listener_end: %s", temps);
+        free(temps);
+    }
+    else logDebug("listener_end: INVALID");
+    if(!knIPV4Endpoint_isINVALID(connector_end)){
+        temps = knIPV4Endpoint_toString(&connector_end);
+        logDebug("connector_end: %s", temps);
+        free(temps);
+    }
+    else logDebug("connector_end: INVALID");
+    logDebug("encryption_key: %s", encryption_key ? encryption_key : "NULL");
+    logDebug("decryption_key: %s", decryption_key ? decryption_key : "NULL");
+    logDebug("log_level: %i", log_level);
+
+    // create and run Listener or Connector
+    if(input_mode == InputMode_Connect){
+        if(tunnel_protocol == TunnelProtocol_UDP){
+            ConnectorUDP connector;
+            ConnectorUDP_construct(&connector, listener_end, connector_end, output_mode);
+            ConnectorUDP_start(&connector);
+            ConnectorUDP_destruct(&connector);
+        }
+        else if(tunnel_protocol == TunnelProtocol_TCP){
+            ConnectorTCP connector;
+            ConnectorTCP_construct(&connector, listener_end, connector_end, output_mode);
+            ConnectorTCP_start(&connector);
+            ConnectorTCP_destruct(&connector);
+        }
+        else throw("no tunnel protocol has been selected");
+    }
+    else if(input_mode == InputMode_Listen){
+        if(tunnel_protocol == TunnelProtocol_UDP){
+            ListenerUDP listener;
+            ListenerUDP_construct(&listener, listener_end);
+            ListenerUDP_start(&listener);
+            ListenerUDP_destruct(&listener);
+        }
+        else if(tunnel_protocol == TunnelProtocol_TCP){
+            ListenerTCP listener;
+            ListenerTCP_construct(&listener, listener_end);
+            ListenerTCP_start(&listener);
+            ListenerTCP_destruct(&listener);
+        }
+        else throw("no tunnel protocol has been selected");
+    }
+    else throw("no input mode has been selected");
+
+    tryLast(kt_tryDispose(), _m11258, ;)
+    return 0;
+}
diff --git a/src/port-tunnel.h b/src/port-tunnel.h
new file mode 100644
index 0000000..cb4caa1
--- /dev/null
+++ b/src/port-tunnel.h
@@ -0,0 +1,189 @@
+#pragma once
+
+#if __cplusplus
+extern "C" {
+#endif
+
+#include <pthread.h>
+#include "../kerep/src/Network/network.h"
+#include "../kerep/src/Hashtable/Hashtable.h"
+
+/// defined in help_message.c
+extern const char* help_message;
+
+////////////////////////////////////////
+//                Time                //
+////////////////////////////////////////
+
+/// nanoseconds
+typedef u64 nsec_t;
+
+/// miliseconds
+typedef u64 usec_t;
+
+/// system time now in nanoseconds
+///@return u64 will overflow in 13 years
+nsec_t getTimeNsec();
+
+/// system time now in microseconds
+///@return u64 will overflow in 58494 years
+usec_t getTimeUsec();
+
+////////////////////////////////////////
+//               Enums                //
+////////////////////////////////////////
+
+typedef enum {
+    TunnelProtocol_None,
+    TunnelProtocol_TCP,
+    TunnelProtocol_UDP
+} TunnelProtocol;
+
+typedef enum {
+    InputMode_None,
+    InputMode_Listen,
+    InputMode_Connect
+} InputMode;
+
+typedef enum {
+    OutputMode_None,
+    OutputMode_Bind,
+    OutputMode_Send
+} OutputMode;
+
+////////////////////////////////////////
+//               Logging              //
+////////////////////////////////////////
+
+typedef enum LogLevel {
+    LogLevel_Error = 1,
+    LogLevel_Warning = 2,
+    LogLevel_Info = 3,
+    LogLevel_Debug = 4
+} LogLevel;
+
+extern LogLevel _log_level;
+
+#define __logTryPrint(minimumLogLevel, format, args...)\
+    if(_log_level >= minimumLogLevel) \
+        kprintf(format "\n" ,##args)
+
+#define logDebug(format, args...) __logTryPrint(LogLevel_Debug, FGRY format ,##args)
+
+#define logInfo(format, args...) __logTryPrint(LogLevel_Info, FWHI format ,##args)
+
+#define logWarning(format, args...) __logTryPrint(LogLevel_Warning, FYEL format ,##args)
+
+#define logError(format, args...) __logTryPrint(LogLevel_Error, FRED format ,##args)
+
+#define setLogLevel(l) _log_level = l
+
+////////////////////////////////////////
+//               Pipes                //
+////////////////////////////////////////
+
+STRUCT(PipeBase,
+    usec_t last_transmit_time;
+    bool is_transmitting;
+    bool is_closed;
+)
+
+STRUCT(PipeUDP,
+    PipeBase base;
+    knIPV4Endpoint pipe_out_end;
+    knSocketUDP* pipe_in_sock;
+)
+
+void PipeUDP_construct(PipeUDP* pipe, knSocketUDP* pipe_in_sock, knIPV4Endpoint pipe_out_end);
+void PipeUDP_destruct(PipeUDP* pipe);
+void PipeUDP_startAsync(PipeUDP* pipe);
+void PipeUDP_stopAsync(PipeUDP* pipe);
+
+STRUCT(PipeTCP,
+    PipeBase base;
+    knIPV4Endpoint pipe_out_end;
+    knSocketTCP* pipe_in_sock;
+)
+
+void PipeTCP_construct(PipeTCP* pipe, knSocketTCP* pipe_in_sock, knIPV4Endpoint pipe_out_end);
+void PipeTCP_destruct(PipeTCP* pipe);
+void PipeTCP_startAsync(PipeTCP* pipe);
+void PipeTCP_stopAsync(PipeTCP* pipe);
+
+////////////////////////////////////////
+//            Pipe Storage            //
+////////////////////////////////////////
+
+STRUCT(PipeStorage,
+    /* Hashtable<EndpointString, PipeBase*> */
+    Hashtable* table;
+    usec_t last_check_time;
+    bool is_gc_stopped;
+)
+
+void __PipeStorage_construct(PipeStorage* s);
+void __PipeStorage_destruct(PipeStorage* s);
+void __PipeStorage_startGCAsync(PipeStorage* s);
+void __PipeStorage_stopGCAsync(PipeStorage* s);
+
+////////////////////////////////////////
+//             Listeners              //
+////////////////////////////////////////
+
+STRUCT(ListenerUDP,
+    /* Hashtable<EndpointString, PipeUDP*> pipes.table */
+    PipeStorage pipes;
+    knIPV4Endpoint connector_end;
+    knSocketUDP* main_sock;
+)
+
+void ListenerUDP_construct(ListenerUDP* ptr, knIPV4Endpoint listener_end);
+void ListenerUDP_destruct(ListenerUDP* ptr);
+void ListenerUDP_start(ListenerUDP* ptr);
+
+STRUCT(ListenerTCP,
+    /* Hashtable<EndpointString, PipeUDP*> pipes.table */
+    PipeStorage pipes;
+    knIPV4Endpoint connector_end;
+    knSocketTCP* main_sock;
+)
+
+void ListenerTCP_construct(ListenerTCP* ptr, knIPV4Endpoint listener_end);
+void ListenerTCP_destruct(ListenerTCP* ptr);
+void ListenerTCP_start(ListenerTCP* ptr);
+
+////////////////////////////////////////
+//             Connectors             //
+////////////////////////////////////////
+
+STRUCT(ConnectorUDP,
+    /* Hashtable<EndpointString, PipeUDP*> */
+    PipeStorage pipes;
+    knIPV4Endpoint listener_end;
+    knIPV4Endpoint connector_end;
+    knSocketUDP* main_sock;
+    OutputMode out_mode;
+)
+
+void ConnectorUDP_construct(ConnectorUDP* ptr, knIPV4Endpoint listener_end, knIPV4Endpoint connector_end, OutputMode out_mode);
+void ConnectorUDP_destruct(ConnectorUDP* ptr);
+///@return doesn't return, INFINITE LOOP
+void ConnectorUDP_start(ConnectorUDP* ptr);
+
+STRUCT(ConnectorTCP,
+    /* Hashtable<EndpointString, PipeTCP*> */
+    PipeStorage pipes;
+    knIPV4Endpoint listener_end;
+    knIPV4Endpoint connector_end;
+    knSocketTCP* main_sock;
+    OutputMode out_mode;
+)
+
+void ConnectorTCP_construct(ConnectorTCP* ptr, knIPV4Endpoint listener_end, knIPV4Endpoint connector_end, OutputMode out_mode);
+void ConnectorTCP_destruct(ConnectorTCP* ptr);
+///@return doesn't return, INFINITE LOOP
+void ConnectorTCP_start(ConnectorTCP* ptr);
+
+#if __cplusplus
+}
+#endif
diff --git a/src/time.c b/src/time.c
new file mode 100644
index 0000000..f8b23ee
--- /dev/null
+++ b/src/time.c
@@ -0,0 +1,17 @@
+#include "port-tunnel.h"
+
+nsec_t getTimeNsec(){
+    struct timespec t;
+    if(clock_gettime(CLOCK_REALTIME, &t) != 0)
+        throw(ERR_UNEXPECTEDVAL);
+    u64 n = t.tv_sec * 10e9 + t.tv_nsec;
+    return n;
+}
+
+usec_t getTimeUsec(){
+    struct timespec t;
+    if(clock_gettime(CLOCK_REALTIME, &t) != 0)
+        throw(ERR_UNEXPECTEDVAL);
+    u64 n = t.tv_sec * 10e6 + t.tv_nsec / 10e3;
+    return n;
+}