Index: uspace/srv/net/tl/tcp/tcp.c
===================================================================
--- uspace/srv/net/tl/tcp/tcp.c	(revision 7bf123871317a0c9460ed9b58b81cba56a85baae)
+++ uspace/srv/net/tl/tcp/tcp.c	(revision 0743493a4e08f4592e45edfc40bfa33c3c4bacde)
@@ -476,5 +476,5 @@
 	old_incoming = socket_data->next_incoming;
 
-	if (header->finalize) {
+	if (GET_TCP_HEADER_FINALIZE(header)) {
 		socket_data->fin_incoming = new_sequence_number +
 		    total_length - TCP_HEADER_LENGTH(header);
@@ -838,5 +838,5 @@
 	assert(packet);
 
-	if (!header->synchronize)
+	if (!GET_TCP_HEADER_SYNCHRONIZE(header))
 		return tcp_release_and_return(packet, EINVAL);
 	
@@ -903,5 +903,5 @@
 	assert(packet);
 
-	if (!header->synchronize)
+	if (!GET_TCP_HEADER_SYNCHRONIZE(header))
 		return tcp_release_and_return(packet, EINVAL);
 
@@ -1057,5 +1057,5 @@
 	assert(packet);
 
-	if (!header->acknowledge)
+	if (!GET_TCP_HEADER_ACKNOWLEDGE(header))
 		return tcp_release_and_return(packet, EINVAL);
 
@@ -1126,5 +1126,5 @@
 	assert(header);
 
-	if (!header->acknowledge)
+	if (!GET_TCP_HEADER_ACKNOWLEDGE(header))
 		return;
 
@@ -1833,5 +1833,5 @@
 
 	/* Remember the outgoing FIN */
-	if (header->finalize) 
+	if (GET_TCP_HEADER_FINALIZE(header))
 		socket_data->fin_outgoing = socket_data->next_outgoing;
 	
@@ -1952,5 +1952,5 @@
 		header->acknowledgement_number =
 		    htonl(socket_data->next_incoming);
-		header->acknowledge = 1;
+		SET_TCP_HEADER_ACKNOWLEDGE(header, 1);
 	}
 	header->window = htons(socket_data->window);
@@ -2024,7 +2024,8 @@
 	header->source_port = htons(socket->port);
 	header->source_port = htons(socket_data->dest_port);
-	header->header_length = TCP_COMPUTE_HEADER_LENGTH(sizeof(*header));
-	header->synchronize = synchronize;
-	header->finalize = finalize;
+	SET_TCP_HEADER_LENGTH(header,
+	    TCP_COMPUTE_HEADER_LENGTH(sizeof(*header)));
+	SET_TCP_HEADER_SYNCHRONIZE(header, synchronize);
+	SET_TCP_HEADER_FINALIZE(header, finalize);
 }
 
Index: uspace/srv/net/tl/tcp/tcp_header.h
===================================================================
--- uspace/srv/net/tl/tcp/tcp_header.h	(revision 7bf123871317a0c9460ed9b58b81cba56a85baae)
+++ uspace/srv/net/tl/tcp/tcp_header.h	(revision 0743493a4e08f4592e45edfc40bfa33c3c4bacde)
@@ -47,5 +47,5 @@
  * @param[in] header The TCP packet header.
  */
-#define TCP_HEADER_LENGTH(header)		((header)->header_length * 4U)
+#define TCP_HEADER_LENGTH(header)		(GET_TCP_HEADER_LENGTH(header) * 4U)
 
 /** Returns the TCP header length.
@@ -73,30 +73,63 @@
 	uint32_t sequence_number;
 	uint32_t acknowledgement_number;
-	
-#ifdef ARCH_IS_BIG_ENDIAN
-	uint8_t header_length:4;
-	uint8_t reserved1:4;
-#else
-	uint8_t reserved1:4;
-	uint8_t header_length:4;
-#endif
 
-#ifdef ARCH_IS_BIG_ENDIAN
-	uint8_t reserved2:2;
-	uint8_t urgent:1;
-	uint8_t acknowledge:1;
-	uint8_t push:1;
-	uint8_t reset:1;
-	uint8_t synchronize:1;
-	uint8_t finalize:1;
-#else
-	uint8_t finalize:1;
-	uint8_t synchronize:1;
-	uint8_t reset:1;
-	uint8_t push:1;
-	uint8_t acknowledge:1;
-	uint8_t urgent:1;
-	uint8_t reserved2:2;
-#endif
+	uint8_t hlr; /* header length, reserved1 */
+
+#define GET_TCP_HEADER_LENGTH(header) \
+	(((header)->hlr & 0xf0) >> 4)
+#define SET_TCP_HEADER_LENGTH(header, length) \
+	((header)->hlr = \
+	 ((length & 0x0f) << 4) | ((header)->hlr & 0x0f))
+
+#define GET_TCP_HEADER_RESERVED1(header) \
+	((header)->hlr & 0x0f)
+#define SET_TCP_HEADER_RESERVED1(header, reserved1) \
+	((header)->hlr = \
+	 (reserved1 & 0x0f) | ((header)->hlr & 0xf0))
+
+	/* reserved2, urgent, acknowledge, push, reset, synchronize, finalize */
+	uint8_t ruaprsf;  
+
+#define GET_TCP_HEADER_RESERVED2(header) \
+	(((header)->ruaprsf & 0xc0) >> 6)
+#define SET_TCP_HEADER_RESERVED2(header, reserved2) \
+	((header)->ruaprsf = \
+	 ((reserved2 & 0x03) << 6) | ((header)->ruaprsf & 0x3f))
+
+#define GET_TCP_HEADER_URGENT(header) \
+	(((header)->ruaprsf & 0x20) >> 5)
+#define SET_TCP_HEADER_URGENT(header, urgent) \
+	((header)->ruaprsf = \
+	 ((urgent & 0x01) << 5) | ((header)->ruaprsf & 0xdf))
+
+#define GET_TCP_HEADER_ACKNOWLEDGE(header) \
+	(((header)->ruaprsf & 0x10) >> 4)
+#define SET_TCP_HEADER_ACKNOWLEDGE(header, acknowledge) \
+	((header)->ruaprsf = \
+	 ((acknowledge & 0x01) << 4) | ((header)->ruaprsf & 0xef))
+
+#define GET_TCP_HEADER_PUSH(header) \
+	(((header)->ruaprsf & 0x08) >> 3)
+#define SET_TCP_HEADER_PUSH(header, push) \
+	((header)->ruaprsf = \
+	 ((push & 0x01) << 3) | ((header)->ruaprsf & 0xf7))
+
+#define GET_TCP_HEADER_RESET(header) \
+	(((header)->ruaprsf & 0x04) >> 2)
+#define SET_TCP_HEADER_RESET(header, reset) \
+	((header)->ruaprsf = \
+	 ((reset & 0x01) << 2) | ((header)->ruaprsf & 0xfb))
+
+#define GET_TCP_HEADER_SYNCHRONIZE(header) \
+	(((header)->ruaprsf & 0x02) >> 1)
+#define SET_TCP_HEADER_SYNCHRONIZE(header, synchronize) \
+	((header)->ruaprsf = \
+	 ((synchronize & 0x01) << 1) | ((header)->ruaprsf & 0xfd))
+
+#define GET_TCP_HEADER_FINALIZE(header) \
+	((header)->ruaprsf & 0x01)
+#define SET_TCP_HEADER_FINALIZE(header, finalize) \
+	((header)->ruaprsf = \
+	 (finalize & 0x01) | ((header)->ruaprsf & 0xfe))
 
 	uint16_t window;