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source: trunk/kernel/devices/dev_nic.c @ 672

Last change on this file since 672 was 668, checked in by alain, 4 years ago
typos...
File size: 118.1 KB

Rev	Line
[663]	1
[1]	2	/*
	3	* dev_nic.c - NIC (Network Controler) generic device API implementation.
	4	*
[657]	5	* Author Alain Greiner (2016,2017,2018,2019,2020)
[1]	6	*
	7	* Copyright (c) UPMC Sorbonne Universites
	8	*
	9	* This file is part of ALMOS-MKH.
	10	*
	11	* ALMOS-MKH is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by
	13	* the Free Software Foundation; version 2.0 of the License.
	14	*
	15	* ALMOS-MKH is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with ALMOS-MKH; if not, write to the Free Software Foundation,
	22	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	23	*/
	24
[457]	25	#include <hal_kernel_types.h>
[1]	26	#include <hal_special.h>
[657]	27	#include <hal_uspace.h>
	28	#include <remote_buf.h>
[663]	29	#include <memcpy.h>
[1]	30	#include <printk.h>
[3]	31	#include <chdev.h>
[1]	32	#include <thread.h>
[663]	33	#include <ksocket.h>
[259]	34	#include <hal_drivers.h>
[1]	35	#include <dev_nic.h>
[657]	36	#include <vfs.h>
	37	#include <shared_socket.h>
[1]	38
	39	/////////////////////////////////////////////////////////////////////////////////////////
[657]	40	// Extern global variables
[1]	41	/////////////////////////////////////////////////////////////////////////////////////////
	42
[3]	43	extern chdev_directory_t chdev_dir; // allocated in kernel_init.c
[1]	44
[663]	45	////////////////////////////////////
	46	void dev_nic_init( chdev_t * chdev )
	47	{
	48	thread_t * new_thread;
	49	error_t error;
	50
	51	// get "channel" & "is_rx" fields from chdev descriptor
	52	uint32_t channel = chdev->channel;
	53	bool_t is_rx = chdev->is_rx;
	54
	55	// set chdev name
	56	if( is_rx ) snprintf( chdev->name , 16 , "nic%d_rx" , channel );
	57	else snprintf( chdev->name , 16 , "nic%d_tx" , channel );
	58
	59	// initialize the root of the listening sockets list
	60	xlist_root_init( XPTR( local_cxy , &chdev->ext.nic.root ) );
	61
	62	// initialize the lock protecting this list
	63	remote_busylock_init( XPTR( local_cxy , &chdev->ext.nic.lock ),
	64	LOCK_LISTEN_SOCKET );
	65
	66	// call driver init function for this chdev
	67	hal_drivers_nic_init( chdev );
	68
	69	// select a core to execute the NIC server thread
	70	lid_t lid = cluster_select_local_core( local_cxy );
	71
	72	// bind the NIC IRQ to the selected core
	73	dev_pic_bind_irq( lid , chdev );
	74
	75	// build pointer on server function
	76	void * func = is_rx ? &dev_nic_rx_server : &dev_nic_tx_server;
	77
	78	// create server thread
	79	error = thread_kernel_create( &new_thread,
	80	THREAD_DEV,
	81	func,
	82	chdev,
	83	lid );
	84	if( error )
	85	{
	86	printk("\n[PANIC] in %s : cannot create server thread\n", __FUNCTION__ );
	87	return;
	88	}
	89
	90	// set "server" field in chdev descriptor
	91	chdev->server = new_thread;
	92
	93	// set "chdev" field in thread descriptor
	94	new_thread->chdev = chdev;
	95
	96	// unblock server thread
	97	thread_unblock( XPTR( local_cxy , new_thread ) , THREAD_BLOCKED_GLOBAL );
	98
	99	#if (DEBUG_DEV_NIC_TX \|\| DEBUG_DEV_NIC_RX)
	100	thread_t * this = CURRENT_THREAD;
	101	if( is_rx )
	102	printk("\n[%s] thread[%x,%x] initialized NIC_RX[%d] / server %x\n",
	103	__FUNCTION__, this->process->pid, this->trdid, channel, new_thread->trdid );
	104	else
	105	printk("\n[%s] thread[%x,%x] initialized NIC_TX[%d] / server %x\n",
	106	__FUNCTION__, this->process->pid, this->trdid, channel, new_thread->trdid );
	107	#endif
	108
	109	} // end dev_nic_init()
	110
	111
	112	///////////////////////////////////////////////////////////////////////////////////////////
	113	// Functions directly called by the client threads
	114	///////////////////////////////////////////////////////////////////////////////////////////
	115
	116	////////////////////////////////////////
	117	uint32_t dev_nic_get_key( uint32_t addr,
	118	uint16_t port )
	119	{
	120	thread_t * this = CURRENT_THREAD;
	121
	122	xptr_t dev_xp = chdev_dir.nic_tx[0];
	123	chdev_t * dev_ptr = GET_PTR( dev_xp );
	124
	125	if( dev_xp == XPTR_NULL ) return -1;
	126
	127	// set command arguments in client thread descriptor
	128	this->nic_cmd.buffer = (uint8_t *)addr;
	129	this->nic_cmd.length = (uint32_t)port;
	130	this->nic_cmd.dev_xp = dev_xp;
	131	this->nic_cmd.type = NIC_CMD_GET_KEY;
	132
	133	// call driver
	134	dev_ptr->cmd( XPTR( local_cxy , this ) );
	135
	136	// get "status"
	137	return this->nic_cmd.status;
	138	}
	139
	140	//////////////////////////////////////////
	141	error_t dev_nic_set_run( uint32_t channel,
	142	uint32_t run )
	143	{
	144	thread_t * this = CURRENT_THREAD;
	145
	146	if( channel >= LOCAL_CLUSTER->nb_nic_channels ) return -1;
	147
	148	xptr_t dev_xp = chdev_dir.nic_tx[0];
	149	chdev_t * dev_ptr = GET_PTR( dev_xp );
	150
	151	if( dev_xp == XPTR_NULL ) return -1;
	152
	153	// set command arguments in client thread descriptor
	154	this->nic_cmd.dev_xp = dev_xp;
	155	this->nic_cmd.type = NIC_CMD_SET_RUN;
	156	this->nic_cmd.length = channel;
	157	this->nic_cmd.status = run;
	158
	159	// call driver
	160	dev_ptr->cmd( XPTR( local_cxy , this ) );
	161
	162	// return "error"
	163	return this->nic_cmd.error;
	164	}
	165
	166	//////////////////////////////////
	167	error_t dev_nic_get_instru( void )
	168	{
	169	thread_t * this = CURRENT_THREAD;
	170
	171	xptr_t dev_xp = chdev_dir.nic_tx[0];
	172	chdev_t * dev_ptr = GET_PTR( dev_xp );
	173
	174	if( dev_xp == XPTR_NULL ) return -1;
	175
	176	// set command arguments in client thread descriptor
	177	this->nic_cmd.dev_xp = dev_xp;
	178	this->nic_cmd.type = NIC_CMD_GET_INSTRU;
	179
	180	// call driver
	181	dev_ptr->cmd( XPTR( local_cxy , this ) );
	182
	183	// return "error"
	184	return this->nic_cmd.error;
	185	}
	186
	187	////////////////////////////////////
	188	error_t dev_nic_clear_instru( void )
	189	{
	190	thread_t * this = CURRENT_THREAD;
	191
	192	xptr_t dev_xp = chdev_dir.nic_tx[0];
	193	chdev_t * dev_ptr = GET_PTR( dev_xp );
	194
	195	if( dev_xp == XPTR_NULL ) return -1;
	196
	197	// set command arguments in client thread descriptor
	198	this->nic_cmd.dev_xp = dev_xp;
	199	this->nic_cmd.type = NIC_CMD_GET_INSTRU;
	200
	201	// call driver
	202	dev_ptr->cmd( XPTR( local_cxy , this ) );
	203
	204	// return "error"
	205	return this->nic_cmd.error;
	206	}
	207
	208
[657]	209	////////////////////////////////////////////////////////////////////////////////////////////
[663]	210	// Static functions called by the NIC_RX server & NIC_TX server threads
[657]	211	////////////////////////////////////////////////////////////////////////////////////////////
[663]	212
	213	////////////////////////////////////////////////////////////////////////////////////////////
	214	// This static function is used by the dev_nic_rx_handle_tcp() function
	215	// to check acceptability of a given sequence number. It returns true when
	216	// the <seq> argument is contained in a wrap-around window defined by the
	217	// <min> and <max> arguments. The window wrap-around when (min > max).
	218	////////////////////////////////////////////////////////////////////////////////////////////
[657]	219	// @ seq : [in] value to be checked.
	220	// @ min : [in] first base.
	221	// @ max : [in] window size.
	222	////////////////////////////////////////////////////////////////////////////////////////////
	223	static inline bool_t is_in_window( uint32_t seq,
	224	uint32_t min,
	225	uint32_t max )
	226	{
	227	if( max >= min ) // no wrap_around => only one window [min,max]
	228	{
	229	return( (seq >= min) && (seq <= max) );
	230	}
	231	else // window wrap-around => two windows [min,0xFFFFFFFF] and [0,max]
	232	{
	233	return( (seq <= max) \|\| (seq >= min) );
	234	}
	235	}
	236
	237	////////////////////////////////////////////////////////////////////////////////////////
	238	// This static function computes the checksum for an IP packet header.
	239	// The "checksum" field itself is not taken into account for this computation.
	240	////////////////////////////////////////////////////////////////////////////////////////
	241	// @ buffer : [in] pointer on IP packet header (20 bytes)
	242	// @ return the checksum value on 16 bits
	243	////////////////////////////////////////////////////////////////////////////////////////
[663]	244	static uint16_t dev_nic_ip_checksum( uint8_t * buffer )
[657]	245	{
	246	uint32_t i;
	247	uint32_t cs; // 32 bits accumulator
	248	uint16_t * buf;
	249
	250	buf = (uint16_t *)buffer;
	251
	252	// compute checksum
	253	for( i = 0 , cs = 0 ; i < 10 ; i++ )
	254	{
	255	if( i != 5 ) cs += buf[i];
	256	}
	257
	258	// one's complement
	259	return ~cs;
	260	}
	261
	262	////////////////////////////////////////////////////////////////////////////////////////
	263	// This static function computes the checksum for an UDP packet defined by
	264	// the <buffer> and <size> arguments.
	265	////////////////////////////////////////////////////////////////////////////////////////
	266	// @ buffer : [in] pointer on UDP packet base.
	267	// @ size : [in] number of bytes in this packet (including header).
	268	// @ return the checksum value on 16 bits
	269	////////////////////////////////////////////////////////////////////////////////////////
[663]	270	static uint16_t dev_nic_udp_checksum( uint8_t * buffer,
	271	uint32_t size )
[657]	272	{
	273	uint32_t i;
	274	uint32_t carry;
	275	uint32_t cs; // 32 bits accumulator
	276	uint16_t * buf;
	277	uint32_t max; // number of uint16_t in packet
	278
	279	// compute max & buf
	280	buf = (uint16_t *)buffer;
	281	max = size >> 1;
	282
	283	// extend buffer[] if required
	284	if( size & 1 )
	285	{
	286	max++;
	287	buffer[size] = 0;
	288	}
	289
	290	// compute checksum for UDP packet
	291	for( i = 0 , cs = 0 ; i < size ; i++ ) cs += buf[i];
	292
	293	// handle carry
	294	carry = (cs >> 16);
	295	if( carry )
	296	{
	297	cs += carry;
	298	carry = (cs >> 16);
	299	if( carry ) cs += carry;
	300	}
	301
	302	// one's complement
	303	return ~cs;
	304	}
	305
	306	////////////////////////////////////////////////////////////////////////////////////////
[663]	307	// This static function computes the checksum for a TCP segment defined by the <buffer>
	308	// and <size> arguments. It includes the pseudo header defined by the <src_ip_addr>,
	309	// <dst_ip_addr>, <size> arguments, and by the TCP_PROTOCOL code.
[657]	310	////////////////////////////////////////////////////////////////////////////////////////
	311	// @ buffer : [in] pointer on TCP segment base.
[663]	312	// @ tcp_length : [in] number of bytes in this TCP segment (including header).
[657]	313	// @ src_ip_addr : [in] source IP address (pseudo header)
	314	// @ dst_ip_addr : [in] destination IP address (pseudo header)
	315	// @ return the checksum value on 16 bits
	316	////////////////////////////////////////////////////////////////////////////////////////
[663]	317	static uint16_t dev_nic_tcp_checksum( uint8_t * buffer,
	318	uint32_t tcp_length,
	319	uint32_t src_ip_addr,
	320	uint32_t dst_ip_addr )
[657]	321	{
	322	uint32_t i;
	323	uint32_t carry;
	324	uint32_t cs; // 32 bits accumulator
	325	uint16_t * buf;
	326	uint32_t max; // number of uint16_t in segment
	327
	328	// compute max & buf
	329	buf = (uint16_t *)buffer;
[663]	330	max = tcp_length >> 1;
[657]	331
	332	// extend buffer[] if required
[663]	333	if( tcp_length & 1 )
[657]	334	{
	335	max++;
[663]	336	buffer[tcp_length] = 0;
[657]	337	}
	338
	339	// compute checksum for TCP segment
[663]	340	for( i = 0 , cs = 0 ; i < tcp_length ; i++ ) cs += buf[i];
[657]	341
	342	// complete checksum for pseudo-header
	343	cs += src_ip_addr;
	344	cs += dst_ip_addr;
	345	cs += PROTOCOL_TCP;
[663]	346	cs += tcp_length;
[657]	347
	348	// handle carry
	349	carry = (cs >> 16);
	350	if( carry )
	351	{
	352	cs += carry;
	353	carry = (cs >> 16);
	354	if( carry ) cs += carry;
	355	}
	356
	357	// one's complement
	358	return ~cs;
	359	}
	360
[663]	361	///////////////////////////////////////////////////////////////////////////////////////////
	362	// This static function can be called by the NIC_TX or NIC_RX server threads to unblock
	363	// the TX client thread after completion (success or error) of a TX command registered
	364	// in a socket identified by the <socket_xp> argument. The <status> argument defines
	365	// the command success/failure status: a null value signals a success, a non-null value
	366	// signals a failure. For all commands, it copies the status value in the tx_sts field,
	367	// and print an error message on TXT0 in case of failure.
	368	///////////////////////////////////////////////////////////////////////////////////////////
	369	// @ socket_xp : [in] extended pointer on socket
	370	// @ status : [in] command status (see above)
	371	///////////////////////////////////////////////////////////////////////////////////////////
	372	static void dev_nic_unblock_tx_client( xptr_t socket_xp,
	373	int32_t status )
[1]	374	{
[663]	375	// get socket thread cluster and local pointer
	376	socket_t * socket_ptr = GET_PTR( socket_xp );
	377	cxy_t socket_cxy = GET_CXY( socket_xp );
[1]	378
[663]	379	if( status != CMD_STS_SUCCESS )
[657]	380	{
[663]	381	uint32_t sock_state = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->state ));
	382	uint32_t cmd_type = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->tx_cmd ));
	383	pid_t pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ));
	384	fdid_t fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ));
[657]	385
[668]	386	printk("\n[WARNING] reported by %s : socket[%x,%d] / %s / cmd %s / status %s \n",
[663]	387	__FUNCTION__, pid, fdid, socket_state_str(sock_state),
	388	socket_cmd_type_str(cmd_type), socket_cmd_sts_str(status) );
[657]	389	}
	390
[663]	391	// set tx_sts field in socket descriptor
	392	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_sts ) , status );
[657]	393
[663]	394	// get extended point on TX client thread
	395	xptr_t client_xp = hal_remote_l64( XPTR( socket_cxy , &socket_ptr->tx_client ));
[657]	396
[663]	397	// unblock the client thread
	398	thread_unblock( client_xp , THREAD_BLOCKED_IO );
[657]	399
[663]	400	} // end dev_nic_unblock_tx_client()
[657]	401
[663]	402	///////////////////////////////////////////////////////////////////////////////////////////
	403	// This static function can be called by the NIC_TX or NIC_RX server threads to unblock
	404	// the RX client thread after completion (success or error) of an RX command registered
	405	// in a socket identified by the <socket_xp> argument. The <status> argument defines
	406	// the command success/failure status: a null value signals a success, a non-null value
	407	// signals a failure. For all commands, it copies the status value in the rx_sts field,
	408	// and print an error message on TXT0 in case of failure.
	409	///////////////////////////////////////////////////////////////////////////////////////////
	410	// @ socket_xp : [in] extended pointer on socket
	411	// @ status : [in] command status (see above)
	412	///////////////////////////////////////////////////////////////////////////////////////////
	413	static void dev_nic_unblock_rx_client( xptr_t socket_xp,
	414	int32_t status )
[657]	415	{
[663]	416	// get socket thread cluster and local pointer
	417	socket_t * socket_ptr = GET_PTR( socket_xp );
	418	cxy_t socket_cxy = GET_CXY( socket_xp );
[657]	419
[663]	420	if( status != CMD_STS_SUCCESS )
[657]	421	{
[663]	422	uint32_t sock_state = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->state ));
	423	uint32_t cmd_type = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->rx_cmd ));
	424	pid_t pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ));
	425	fdid_t fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ));
[657]	426
[668]	427	printk("\n[WARNING] reported by %s : socket[%x,%d] / %s / cmd %s / status %s\n",
[663]	428	__FUNCTION__, pid, fdid, socket_state_str(sock_state),
	429	socket_cmd_type_str(cmd_type), socket_cmd_sts_str(status) );
[657]	430	}
	431
[663]	432	// set rx_sts field in socket descriptor
	433	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_sts ) , status );
[657]	434
[663]	435	// get extended point on RX client thread
	436	xptr_t client_xp = hal_remote_l64( XPTR( socket_cxy , &socket_ptr->rx_client ));
[657]	437
[663]	438	// unblock the client thread
	439	thread_unblock( client_xp , THREAD_BLOCKED_IO );
[657]	440
[663]	441	} // end dev_nic_unblock_rx_client()
[657]	442
	443
	444
	445	///////////////////////////////////////////////////////////////////////////////////////////
	446	// Functions called by the NIC_RX server thread
	447	///////////////////////////////////////////////////////////////////////////////////////////
	448
	449	///////////////////////////////////////////////////////////////////////////////////////////
	450	// This static function is called by the dev_nic_rx_server() function.
	451	// It analyses an Ethernet frame contained in the kernel buffer defined
	452	// by the <buffer> argument, and returns in the <ip_length> argument the length
	453	// of the IP packet contained in the Ethernet packet payload.
	454	///////////////////////////////////////////////////////////////////////////////////////////
	455	// @ buffer : [in] pointer on a received Ethernet packet
	456	// @ ip_length : [out] length of IP packet (in bytes).
	457	// @ return 0 if success / return -1 if illegal packet length.
	458	///////////////////////////////////////////////////////////////////////////////////////////
	459	static error_t dev_nic_rx_check_eth( uint8_t * buffer,
	460	uint32_t * ip_length )
	461	{
	462	uint32_t length = ((uint32_t)buffer[12] << 8) \| (uint32_t)buffer[13];
	463
	464	*ip_length = length;
	465
[1]	466	return 0;
[657]	467	}
	468
	469	///////////////////////////////////////////////////////////////////////////////////////////
	470	// This static function analyses the IP packet contained in the kernel buffer
	471	// defined by the <buffer> argument, and returns in the <ip_src_addr>, <ip_dst_addr>,
	472	// <header_length> and <protocol> arguments the informations contained in the IP header.
	473	// It checks the IP packet length versus the value contained in Ethernet header.
	474	// It checks the IP header checksum.
	475	///////////////////////////////////////////////////////////////////////////////////////////
	476	// @ buffer : [in] pointer on the IP packet.
	477	// @ expected_length : [in] expected IP packet length (from Ethernet header).
	478	// @ ip_src_addr : [out] source IP address.
	479	// @ ip_dst_addr : [out] destination IP address.
	480	// @ protocol : [out] transport protocol type.
	481	// @ return 0 if success / return -1 if illegal packet.
	482	///////////////////////////////////////////////////////////////////////////////////////////
	483	static error_t dev_nic_rx_check_ip( uint8_t * buffer,
	484	uint32_t expected_length,
	485	uint32_t * ip_src_addr,
	486	uint32_t * ip_dst_addr,
	487	uint32_t * trsp_protocol )
	488	{
[663]	489
	490	#if DEBUG_DEV_NIC_RX
	491	thread_t * this = CURRENT_THREAD;
	492	uint32_t cycle = (uint32_t)hal_get_cycles();
	493	#endif
	494
	495	// get packet length
[657]	496	uint32_t length = ((uint32_t)buffer[2] << 8) \| (uint32_t)buffer[3];
[1]	497
[663]	498	// discard packet if eth_payload_length != ip_length
[657]	499	if( length != expected_length )
	500	{
[1]	501
[663]	502	#if DEBUG_DEV_NIC_RX
	503	if( DEBUG_DEV_NIC_RX < cycle )
	504	printk("\n[%s] thread[%x,%x] failure : length (%d) != expected_length (%d)\n",
[657]	505	__FUNCTION__, this->process->pid, this->trdid, length, expected_length );
	506	#endif
[663]	507	return -1;
	508	}
[1]	509
[663]	510	// get transport protocol type
	511	uint8_t protocol = buffer[9];
	512
	513	// discard packet if unsupported protocol
	514	if( (protocol != PROTOCOL_TCP) && (protocol != PROTOCOL_UDP) )
	515	{
	516
	517	#if DEBUG_DEV_NIC_RX
	518	if( DEBUG_DEV_NIC_RX < cycle )
	519	printk("\n[%s] thread[%x,%x] failure : unsupported transport protocol (%d)\n",
	520	__FUNCTION__, this->process->pid, this->trdid, protocol );
	521	#endif
[657]	522	return -1;
[663]	523
[657]	524	}
	525	// compute IP header checksum
[663]	526	uint32_t computed_cs = (uint32_t)dev_nic_ip_checksum( buffer );
[657]	527
	528	// extract IP header checksum
[663]	529	uint32_t received_cs = ((uint32_t)buffer[10] << 8) \| ((uint32_t)buffer[11]);
[657]	530
	531	// discard packet if bad checksum
	532	if( received_cs != computed_cs )
	533	{
	534
[663]	535	#if DEBUG_DEV_NIC_RX
	536	if( DEBUG_DEV_NIC_RX < cycle )
	537	printk("\n[%s] thread[%x,%x] failure : computed checksum (%d) != received checksum (%d)\n",
[657]	538	__FUNCTION__, this->process->pid, this->trdid, computed_cs, received_cs );
	539	#endif
	540	return -1;
	541	}
	542
	543
	544	*ip_src_addr = ((uint32_t)buffer[12] << 24) \|
	545	((uint32_t)buffer[13] << 16) \|
	546	((uint32_t)buffer[14] << 8) \|
	547	((uint32_t)buffer[15] ) ;
	548
	549	*ip_dst_addr = ((uint32_t)buffer[16] << 24) \|
	550	((uint32_t)buffer[17] << 16) \|
	551	((uint32_t)buffer[18] << 8) \|
	552	((uint32_t)buffer[19] ) ;
	553
[663]	554	*trsp_protocol = protocol;
[657]	555
	556	return 0;
	557	}
	558
	559	///////////////////////////////////////////////////////////////////////////////////////////
	560	// This static function analyses the UDP packet contained in the kernel buffer
	561	// defined by the <k_buf> and <k_length> arguments.
	562	// It checks the UDP checksum, and discard corrupted packets.
	563	// It scans the list of sockets attached to the NIC_RX chdev to find a matching socket,
	564	// and discard the received packet if no UDP socket found.
	565	// Finally, it copies the payload to the socket "rx_buf", as long as the packet payload
	566	// is not larger than the rx_buf.
	567	// It set the "rx_valid" flip-flop, and unblock the client thread when the last expected
	568	// byte has been received.
	569	///////////////////////////////////////////////////////////////////////////////////////////
	570	// @ chdev : [in] local pointer on local NIC_RX chdev descriptor.
	571	// @ k_buf : [in] pointer on the UDP packet in local kernel buffer.
	572	// @ k_length : [in] number of bytes in buffer (including UDP header).
	573	// @ pkt_src_addr : [in] source IP address (from IP packet header).
	574	// @ pkt_dst_addr : [in] destination IP address (from IP packet header).
	575	///////////////////////////////////////////////////////////////////////////////////////////
	576	static void dev_nic_rx_handle_udp_packet( chdev_t * chdev,
	577	uint8_t * k_buf,
	578	uint32_t k_length,
	579	uint32_t pkt_src_addr,
	580	uint32_t pkt_dst_addr )
[1]	581	{
[657]	582	xptr_t root_xp; // extended pointer on attached sockets list root
	583	xptr_t lock_xp; // extended pointer on chdev lock
	584	xptr_t iter_xp; // iterator on socket list
	585	xptr_t socket_xp; // extended pointer on socket descriptor
	586	cxy_t socket_cxy;
	587	socket_t * socket_ptr;
	588	uint32_t socket_type; // socket type
	589	uint32_t socket_state; // socket state
	590	uint32_t local_addr; // local IP address from socket
	591	uint32_t local_port; // local port from socket
	592	uint32_t remote_addr; // remote IP address from socket
	593	uint32_t remote_port; // remote port from socket
	594	bool_t match_socket; // matching socket found
	595	uint16_t checksum; // computed checksum
	596	uint16_t pkt_checksum; // received checksum
	597	xptr_t socket_rbuf_xp; // extended pointer on socket rx_buf
	598	xptr_t socket_lock_xp; // extended pointer on socket lock
	599	xptr_t socket_client_xp; // extended pointer on socket rx_client field
	600	xptr_t client_xp; // extended pointer on client thread descriptor
	601	uint32_t payload; // number of bytes in payload
	602	uint32_t status; // number of bytes in rx_buf
	603	uint32_t space; // number of free slots in rx_buf
	604	uint32_t moved_bytes; // number of bytes actually moved to rx_buf
[1]	605
[657]	606	// build extended pointers on list of sockets attached to NIC_RX chdev
	607	root_xp = XPTR( local_cxy , &chdev->wait_root );
	608	lock_xp = XPTR( local_cxy , &chdev->wait_lock );
[1]	609
[657]	610	// compute UDP packet checksum
	611	checksum = dev_nic_udp_checksum( k_buf , k_length );
[1]	612
[657]	613	// get checksum from received packet header
	614	pkt_checksum = ((uint16_t)k_buf[6] << 8) \| (uint16_t)k_buf[7];
	615
	616	// discard corrupted packet
	617	if( pkt_checksum != checksum ) return;
	618
	619	// get src_port and dst_port from UDP header
	620	uint32_t pkt_src_port = ((uint32_t)k_buf[0] << 8) \| (uint32_t)k_buf[1];
	621	uint32_t pkt_dst_port = ((uint32_t)k_buf[2] << 8) \| (uint32_t)k_buf[3];
	622
	623	// discard unexpected packet
	624	if( xlist_is_empty( root_xp ) ) return;
	625
[663]	626	// take the lock protecting the sockets list
[657]	627	remote_busylock_acquire( lock_xp );
	628
	629	match_socket = false;
	630
	631	// scan sockets list to find a match
	632	XLIST_FOREACH( root_xp , iter_xp )
	633	{
	634	// get socket cluster and local pointer
	635	socket_xp = XLIST_ELEMENT( iter_xp , socket_t , rx_list );
	636	socket_ptr = GET_PTR( socket_xp );
	637	socket_cxy = GET_CXY( socket_xp );
	638
	639	// get socket type
	640	socket_type = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->type ));
	641	socket_state = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->state ));
	642
	643	// skip TCP socket
	644	if( socket_type == SOCK_STREAM ) continue;
	645
	646	// get relevant info from socket descriptor
	647	local_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_addr ));
	648	remote_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_addr ));
	649	local_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_port ));
	650	remote_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_port ));
	651
	652	// compute matching
	653	bool_t local_match = (local_addr == pkt_dst_addr) &&
	654	(local_port == pkt_dst_port);
	655
	656	bool_t remote_match = (remote_addr == pkt_src_addr) &&
	657	(remote_port == pkt_src_port);
	658
[663]	659	if (socket_state == UDP_STATE_ESTAB ) match_socket = local_match && remote_match;
	660	else match_socket = local_match;
[657]	661
	662	// exit loop when socket found
	663	if( match_socket ) break;
	664	}
	665
	666	// release the lock protecting the sockets list
	667	remote_busylock_release( lock_xp );
	668
	669	// discard unexpected packet
	670	if( match_socket == false ) return;
	671
	672	// build extended pointers on various socket fields
	673	socket_rbuf_xp = XPTR( socket_cxy , &socket_ptr->rx_buf );
	674	socket_lock_xp = XPTR( socket_cxy , &socket_ptr->lock );
	675	socket_client_xp = XPTR( socket_cxy , &socket_ptr->rx_client );
	676
	677	// take the lock protecting the socket
[663]	678	remote_queuelock_acquire( socket_lock_xp );
[657]	679
	680	// get status & space from rx_buf
	681	status = remote_buf_status( socket_rbuf_xp );
	682	space = NIC_RX_BUF_SIZE - status;
	683
	684	// get client thread
	685	client_xp = hal_remote_l64( socket_client_xp );
	686
	687	// get number of bytes in payload
	688	payload = k_length - UDP_HEAD_LEN;
	689
	690	// compute number of bytes to move : min (space , seg_payload)
	691	moved_bytes = ( space < payload ) ? space : payload;
	692
	693	// move payload from kernel buffer to socket rx_buf
	694	remote_buf_put_from_kernel( socket_rbuf_xp,
	695	k_buf + UDP_HEAD_LEN,
	696	moved_bytes );
[663]	697	// unblock client thread
[657]	698	if( client_xp != XPTR_NULL )
	699	{
	700	thread_unblock( client_xp , THREAD_BLOCKED_IO );
	701	}
	702
	703	// release the lock protecting the socket
[663]	704	remote_queuelock_release( socket_lock_xp );
[657]	705
	706	} // end dev_nic_rx_handle_udp_packet()
	707
	708	///////////////////////////////////////////////////////////////////////////////////////////
	709	// This static function is called by the dev_nic_rx_server() function to handle one RX
	710	// TCP segment contained in a kernel buffer defined by the <k_buf> & <k_length> arguments.
[663]	711	// The <seg_remote_addr> and <seg_local_addr> arguments are obtained from the received
	712	// IP packet header. It the received segment doesn't match any connected socket attached
	713	// to the selected chdev[k], or any listening socket waiting connection, or if the segment
	714	// is corrupted, this segment is discarded.
	715	// If required by the TCP flags, it registers an R2T request in the socket R2T queue
	716	// to implement the TCP handcheck for close and connect.
[657]	717	///////////////////////////////////////////////////////////////////////////////////////////
	718	// Implementation note:
[663]	719	// A "connected" socket is actually a TCP socket already attached to a given NIC_RX[k]
	720	// chdev, and can therefore receive a TCP segment on the NIC channel <k>. A "listening"
	721	// socket is a TCP socket in the LISTEN state. This function operates in 6 steps:
	722	// 1) It checks the TCP checksum, and discard the corrupted segment if corrupted.
	723	// 2) It scans the list of sockets attached to the NIC_RX[k] chdev, to find one TCP
	724	// socket matching the TCP segment header.
	725	// 3) When a matching connected socket is found, it handles the received segment, including
	726	// the SYN, FIN, ACK and RST flags. It updates the socket state when required, moves
	727	// data to the rx_buf when possible, and return. It takes the lock protecting the socket,
	728	// because an connected socket is accessed by both the NIC_TX and NIC_RX server threads.
	729	// 4) If no matching connected socket has been found, it scans the list of listening
	730	// sockets to find a matching listening socket.
	731	// 5) When a matching listening socket is found, it simply registers a new connection
	732	// request in the listening socket CRQ queue, when the SYN flag is set, and insert
	733	// a SYN-ACK request in the socket R2T queue.
	734	// 6) It discards the packet if no connected or listening socket has been found.
[657]	735	///////////////////////////////////////////////////////////////////////////////////////////
[663]	736	// @ chdev : [in] local pointer on local NIC_RX chdev descriptor.
	737	// @ k_buf : [in] pointer on the TCP packet in local kernel buffer.
	738	// @ k_length : [in] number of bytes in buffer (including TCP header).
	739	// @ seg_remote_addr : [in] remote IP address (from IP packet header).
	740	// @ seg_local_addr : [in] local IP address (from IP packet header).
[657]	741	///////////////////////////////////////////////////////////////////////////////////////////
	742	static void dev_nic_rx_handle_tcp_segment( chdev_t * chdev,
	743	uint8_t * k_buf,
	744	uint32_t k_length,
[663]	745	uint32_t seg_remote_addr,
	746	uint32_t seg_local_addr )
[657]	747	{
[663]	748	xptr_t root_xp; // extended pointer on connected sockets list root
	749	xptr_t lock_xp; // extended pointer on chdev lock
	750	xptr_t iter_xp; // iterator for these queues
	751	bool_t attached_match; // true if one attached socket match
	752	bool_t listening_match; // true if one listening socket match
	753	xptr_t socket_xp; // extended pointer on matching socket
	754	cxy_t socket_cxy; // cluster identifier of matching socket
	755	socket_t * socket_ptr; // local pointer on matching socket
	756	uint32_t socket_local_addr; // local IP address from socket
	757	uint32_t socket_local_port; // local port from socket
	758	uint32_t socket_remote_addr; // remote IP address from socket
	759	uint32_t socket_remote_port; // remote port from socket
	760	uint32_t socket_state; // socket state
	761	uint32_t socket_type; // socket type
	762	bool_t socket_tx_valid; // TX command valid
	763	uint32_t socket_tx_cmd; // TX command type
	764	uint32_t socket_tx_todo; // number of TX bytes not sent yet
	765	uint32_t socket_tx_nxt; // next byte to send in TX stream
	766	uint32_t socket_tx_una; // first unacknowledged byte in TX stream
	767	bool_t socket_rx_valid; // RX command valid
	768	uint32_t socket_rx_cmd; // TX command type
	769	uint32_t socket_rx_nxt; // next expected byte in RX stream
	770	uint32_t socket_rx_wnd; // current window value in RX stream
	771	uint32_t socket_rx_irs; // initial sequence index in RX stream
	772	xptr_t socket_lock_xp; // extended pointer on lock protecting socket state
	773	xptr_t socket_rx_buf_xp; // extended pointer on socket rx_buf
	774	xptr_t socket_r2tq_xp; // extended pointer on socket R2T queue
	775	xptr_t socket_crqq_xp; // extended pointer on socket CRQ queue
	776	uint16_t checksum; // computed TCP segment chechsum
	777	error_t error;
[657]	778
	779	// get relevant infos from TCP segment header
[663]	780	uint32_t seg_remote_port = ((uint32_t)k_buf[0] << 8) \| (uint32_t)k_buf[1];
	781	uint32_t seg_local_port = ((uint32_t)k_buf[2] << 8) \| (uint32_t)k_buf[3];
[657]	782
	783	uint32_t seg_seq_num = ((uint32_t)k_buf[4] << 24) \|
	784	((uint32_t)k_buf[5] << 16) \|
	785	((uint32_t)k_buf[6] << 8) \|
	786	((uint32_t)k_buf[7] );
	787
	788	uint32_t seg_ack_num = ((uint32_t)k_buf[8] << 24) \|
	789	((uint32_t)k_buf[9] << 16) \|
	790	((uint32_t)k_buf[10] << 8) \|
	791	((uint32_t)k_buf[11] );
	792
[663]	793	uint8_t seg_hlen = k_buf[12] << 2; // TCP header length in bytes
[657]	794
	795	uint8_t seg_flags = k_buf[13];
	796
	797	bool_t seg_ack_set = ((seg_flags & TCP_FLAG_ACK) != 0);
	798	bool_t seg_syn_set = ((seg_flags & TCP_FLAG_SYN) != 0);
	799	bool_t seg_fin_set = ((seg_flags & TCP_FLAG_FIN) != 0);
	800	bool_t seg_rst_set = ((seg_flags & TCP_FLAG_RST) != 0);
	801
	802	uint16_t seg_window = ((uint32_t)k_buf[14] << 8) \| (uint32_t)k_buf[15];
	803
	804	uint16_t seg_checksum = ((uint32_t)k_buf[16] << 8) \| (uint32_t)k_buf[17];
	805
[663]	806	uint32_t seg_data_len = k_length - seg_hlen; // number of bytes in payload
[657]	807
[663]	808	#if DEBUG_DEV_NIC_RX
	809	thread_t * this = CURRENT_THREAD;
	810	uint32_t cycle;
	811	uint32_t fdid;
	812	pid_t pid;
	813	#endif
	814
	815	#if DEBUG_DEV_NIC_RX
	816	cycle = (uint32_t)hal_get_cycles();
	817	if( cycle > DEBUG_DEV_NIC_RX )
	818	printk("\n[%s] thread[%x,%x] enters / tcp_length %d / tcp_flags %x / cycle %d\n",
	819	__FUNCTION__, this->process->pid, this->trdid, k_length, seg_flags , cycle );
	820	#endif
	821
	822	// compute and check TCP checksum
	823	k_buf[16] = 0;
	824	k_buf[17] = 0;
[657]	825	checksum = dev_nic_tcp_checksum( k_buf,
	826	k_length,
[663]	827	seg_remote_addr,
	828	seg_local_addr );
[657]	829
	830	// discard segment if corrupted
[663]	831	if( seg_checksum != checksum )
	832	{
	833
	834	#if DEBUG_DEV_NIC_RX
	835	if( cycle > DEBUG_DEV_NIC_RX )
	836	printk("\n[%s] thread[%x,%x] tcp checksum failure : received %x / computed %x\n",
	837	__FUNCTION__, this->process->pid, this->trdid, seg_checksum, checksum );
	838	#endif
	839	return;
	840	}
[657]	841
[663]	842	// scan list of attached sockets to find a matching TCP socket
	843	attached_match = false;
[657]	844
[663]	845	// build extended pointer on xlist of sockets attached to NIC_RX chdev
	846	root_xp = XPTR( local_cxy , &chdev->wait_root );
	847	lock_xp = XPTR( local_cxy , &chdev->wait_lock );
	848
	849	// take the lock protecting the list of attached sockets
[657]	850	remote_busylock_acquire( lock_xp );
	851
	852	XLIST_FOREACH( root_xp , iter_xp )
	853	{
	854	// get socket cluster and local pointer
	855	socket_xp = XLIST_ELEMENT( iter_xp , socket_t , rx_list );
	856	socket_ptr = GET_PTR( socket_xp );
	857	socket_cxy = GET_CXY( socket_xp );
	858
	859	// get socket type and state
	860	socket_type = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->type ));
	861	socket_state = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->state ));
	862
	863	// skip UDP socket
	864	if( socket_type == SOCK_DGRAM ) continue;
	865
	866	// get relevant socket infos for matching
[663]	867	socket_local_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_addr ));
	868	socket_remote_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_addr ));
	869	socket_local_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_port ));
	870	socket_remote_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_port ));
[657]	871
[663]	872	// compute matching condition for a connected socket
	873	attached_match = (socket_local_addr == seg_local_addr) &&
	874	(socket_local_port == seg_local_port) &&
	875	(socket_remote_addr == seg_remote_addr) &&
	876	(socket_remote_port == seg_remote_port) ;
	877
	878	// exit loop if matching
	879	if( attached_match )
[657]	880	{
[663]	881
	882	#if DEBUG_DEV_NIC_RX
	883	fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ) );
	884	pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ) );
	885	if( cycle > DEBUG_DEV_NIC_RX )
	886	printk("\n[%s] thread[%x,%x] matching attached socket[%d,%d] / state %s\n",
	887	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state) );
	888	#endif
	889	break;
[657]	890	}
	891
[663]	892	} // end loop on attached sockets
[657]	893
[663]	894	// release the lock protecting the list of attached sockets
[657]	895	remote_busylock_release( lock_xp );
	896
[663]	897	// handle TCP segment for an attached socket
	898	if( attached_match )
	899	{
	900	// The actions depend on both the socket state and the received segment flags :
	901	// - update socket state,
	902	// - move data to rx_buf,
	903	// - register a request in R2T queue when required
	904
	905	// build extended pointers on various socket fields
	906	socket_lock_xp = XPTR( socket_cxy , &socket_ptr->lock );
	907	socket_rx_buf_xp = XPTR( socket_cxy , &socket_ptr->rx_buf );
	908	socket_r2tq_xp = XPTR( socket_cxy , &socket_ptr->r2tq );
[657]	909
[663]	910	// take the lock protecting the matching socket
	911	remote_queuelock_acquire( socket_lock_xp );
[657]	912
[663]	913	// get relevant socket infos from socket descriptor
	914	socket_tx_valid = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->tx_valid ));
	915	socket_tx_cmd = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->tx_cmd ));
	916	socket_tx_todo = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->tx_todo ));
	917	socket_tx_nxt = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->tx_nxt ));
	918	socket_tx_una = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->tx_una ));
[657]	919
[663]	920	socket_rx_valid = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->rx_valid ));
	921	socket_rx_cmd = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->rx_cmd ));
	922	socket_rx_nxt = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->rx_nxt ));
	923	socket_rx_wnd = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->rx_wnd ));
	924	socket_rx_irs = hal_remote_l32(XPTR( socket_cxy , &socket_ptr->rx_irs ));
[657]	925
[663]	926	// handle the received segment, depending on the matching socket state
	927	switch( socket_state )
[657]	928	{
[663]	929	////////////////////////
	930	case TCP_STATE_SYN_SENT: // TCP client waiting for SYN-ACK in connect handshake
[657]	931	{
[663]	932	// [1] check ACK flag
	933	if( seg_ack_set )
	934	{
	935	if( seg_ack_num != TCP_ISS_CLIENT + 1 ) // bad ACK => report error
	936	{
[657]	937
[663]	938	#if DEBUG_DEV_NIC_RX
	939	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : expect ack_num %x / get %x\n",
	940	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	941	socket_state_str(socket_state), TCP_ISS_CLIENT + 1, seg_ack_num );
	942	#endif
	943	// make an RST request to R2T queue
	944	socket_put_r2t_request( socket_r2tq_xp,
	945	TCP_FLAG_RST,
	946	chdev->channel );
	947
	948	// report error to local TX client thread
	949	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADACK );
	950
	951	break;
	952	}
[657]	953	}
	954
[663]	955	// [2] check RST flag // receive RST => report error
	956	if( seg_rst_set )
[657]	957	{
	958
[663]	959	#if DEBUG_DEV_NIC_RX
	960	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received RST flag\n",
	961	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state) );
	962	#endif
	963	// update socket state
	964	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	965	TCP_STATE_BOUND );
[657]	966
[663]	967	// signal error to local TX client thread
	968	dev_nic_unblock_tx_client( socket_xp , CMD_STS_RST );
[657]	969
[663]	970	break;
	971	}
[657]	972
[663]	973	// [3] handle security & precedence TODO ... someday
	974
	975	// [4] handle SYN-ACK
	976	if( seg_syn_set && seg_ack_set ) // received SYN and ACK => report success
	977	{
	978
	979	#if DEBUG_DEV_NIC_RX
	980	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received expected SYN-ACK\n",
	981	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	982	#endif
	983	// set socket.tx_una
	984	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_una), seg_ack_num );
	985
	986	// set socket.rx_irs
	987	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->rx_irs), seg_seq_num );
	988
	989	// set socket.rx_nxt
	990	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->rx_nxt), seg_seq_num + 1 );
	991
[657]	992	// update socket.state
[663]	993	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->state), TCP_STATE_ESTAB );
[657]	994
[663]	995	// make an ACK request to R2T queue
	996	socket_put_r2t_request( socket_r2tq_xp,
	997	TCP_FLAG_ACK,
	998	chdev->channel );
[657]	999
[663]	1000	// report succes to local TX client thread
	1001	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
	1002	}
	1003	else // received SYN without ACK => client becomes server
	1004	{
	1005
	1006	#if DEBUG_DEV_NIC_RX
	1007	printk("\n[%s] thread[%x,%x] for socket[%x,%d] %s : received SYN-ACK => become server\n",
	1008	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1009	#endif
	1010	// update socket.state
	1011	hal_remote_s32( XPTR(socket_cxy,&socket_ptr->state), TCP_STATE_SYN_RCVD );
	1012
	1013	// set socket.tx_nxt
	1014	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_nxt), TCP_ISS_SERVER );
	1015
	1016	// set socket.rx_nxt to seg_seq_num + 1
	1017	hal_remote_s32( XPTR(socket_cxy,&socket_ptr->rx_nxt), seg_seq_num + 1 );
	1018
	1019	// make a SYN.ACK request to R2T queue
	1020	socket_put_r2t_request( socket_r2tq_xp,
	1021	TCP_FLAG_SYN \| TCP_FLAG_ACK,
	1022	chdev->channel );
	1023	}
[657]	1024	break;
	1025	}
	1026	////////////////////////
[663]	1027	case TCP_STATE_SYN_RCVD: // TCP server waiting last ACK in connect handshake
[657]	1028	{
[663]	1029	// [1] check sequence number
	1030	if( seg_seq_num != socket_rx_nxt ) // unexpected SEQ_NUM => discard
[657]	1031	{
	1032
[663]	1033	#if DEBUG_DEV_NIC_RX
	1034	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : expect seq_num %x / get %x\n",
	1035	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1036	socket_state_str(socket_state), socket_rx_nxt, seg_seq_num );
	1037	#endif
	1038	// discard segment without reporting
	1039	break;
	1040	}
[657]	1041
[663]	1042	// [2] handle RST flag // received RST => report error
[657]	1043	if( seg_rst_set )
	1044	{
	1045
[663]	1046	#if DEBUG_DEV_NIC_RX
	1047	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received RST flag\n",
	1048	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1049	#endif
	1050	// update socket state
	1051	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ), TCP_STATE_BOUND );
[657]	1052
[663]	1053	// report error to local TX client thread
	1054	dev_nic_unblock_tx_client( socket_xp , CMD_STS_RST );
	1055
[657]	1056	break;
	1057	}
	1058
[663]	1059	// [3] handle security & precedence TODO ... someday
	1060
	1061	// [4] handle SYN flag
	1062	if( seg_syn_set ) // received SYN => discard
[657]	1063	{
	1064
[663]	1065	#if DEBUG_DEV_NIC_RX
	1066	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received SYN flag\n",
	1067	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1068	#endif
	1069	// discard segment without reporting
	1070	break;
	1071	}
[657]	1072
[663]	1073	// [5] handle ACK flag
	1074	if( seg_ack_set == false ) // missing ACK => discard
	1075	{
[657]	1076
[663]	1077	#if DEBUG_DEV_NIC_RX
	1078	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : no ACK in TCP segment\n",
	1079	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1080	#endif
	1081	// discard segment without reporting
	1082	break;
	1083	}
	1084	else if( seg_ack_num != (TCP_ISS_SERVER + 1) ) // unacceptable ACK
	1085	{
[657]	1086
[663]	1087	#if DEBUG_DEV_NIC_RX
	1088	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : expect ack_num %x / get %x\n",
	1089	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1090	socket_state_str(socket_state), TCP_ISS_SERVER + 1, seg_ack_num );
	1091	#endif
[657]	1092
[663]	1093	// register an RST request to R2TQ for remote TCP client
	1094	socket_put_r2t_request( socket_r2tq_xp,
	1095	TCP_FLAG_RST,
	1096	chdev->channel );
[657]	1097
[663]	1098	// report error to local TX client thread
	1099	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADACK );
	1100	}
	1101	else // acceptable ACK
	1102	{
[657]	1103
[663]	1104	#if DEBUG_DEV_NIC_RX
	1105	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received expected ACK\n",
	1106	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1107	#endif
	1108	// set socket.tx_una
	1109	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_una), seg_ack_num );
	1110
	1111	// update socket.state
	1112	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->state),
	1113	TCP_STATE_ESTAB );
	1114
	1115	// report success to local TX client thread
	1116	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
[657]	1117	}
	1118	break;
	1119	}
[663]	1120	/////////////////////
[657]	1121	case TCP_STATE_ESTAB:
	1122	case TCP_STATE_FIN_WAIT1:
	1123	case TCP_STATE_FIN_WAIT2:
	1124	case TCP_STATE_CLOSE_WAIT:
	1125	case TCP_STATE_CLOSING:
	1126	case TCP_STATE_LAST_ACK:
	1127	case TCP_STATE_TIME_WAIT:
	1128	{
[663]	1129	// [1] check sequence number : out_of_order segments not accepted
	1130	if( seg_seq_num != socket_rx_nxt )
	1131	{
[657]	1132
[663]	1133	#if DEBUG_DEV_NIC_RX
	1134	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : illegal SEQ_NUM %x / expected %x\n",
	1135	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1136	socket_state_str(socket_state), seg_seq_num, socket_rx_nxt );
	1137	#endif
	1138	// discard segment
	1139	break;
	1140	}
[657]	1141
[663]	1142	// check all bytes in window when the payload exist
	1143	// TODO : we could accept bytes that are in window,
	1144	// but this implementation reject all bytes in segment
	1145	if( seg_data_len > 0 )
	1146	{
	1147	// compute min & max acceptable sequence numbers
	1148	uint32_t seq_min = socket_rx_nxt;
	1149	uint32_t seq_max = socket_rx_nxt + socket_rx_wnd - 1;
[657]	1150
[663]	1151	// compute sequence number for last byte in segment
	1152	uint32_t seg_seq_last = seg_seq_num + seg_data_len - 1;
	1153
	1154	if( is_in_window( seg_seq_last, seq_min, seq_max ) == false )
	1155	{
	1156
	1157	#if DEBUG_DEV_NIC_RX
	1158	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : last SEQ_NUM %x not in [%x,%x]\n",
	1159	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1160	socket_state_str(socket_state), seg_seq_last, seq_min, seq_max );
	1161	#endif
	1162	// discard segment
	1163	break;
	1164	}
[657]	1165	}
	1166
	1167	// [2] handle RST flag
	1168	if( seg_rst_set )
	1169	{
	1170
[663]	1171	#if DEBUG_DEV_NIC_RX
	1172	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received RST flag\n",
	1173	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state) );
	1174	#endif
	1175	if( (socket_state == TCP_STATE_ESTAB ) \|\|
	1176	(socket_state == TCP_STATE_FIN_WAIT1 ) \|\|
	1177	(socket_state == TCP_STATE_FIN_WAIT2 ) \|\|
	1178	(socket_state == TCP_STATE_CLOSE_WAIT) )
	1179	{
	1180	// TODO all pending send & received commands
	1181	// must receive "reset" responses
[657]	1182
[663]	1183	// TODO destroy the socket
	1184	}
	1185	else // states CLOSING / LAST_ACK / TIME_WAIT
	1186	{
	1187	// TODO
	1188	}
	1189	break;
[657]	1190	}
	1191
	1192	// [3] handle security & precedence TODO ... someday
	1193
[663]	1194	// [4] check SYN flag
	1195	if( seg_syn_set ) // received SYN => ERROR
	1196	{
[657]	1197
[663]	1198	#if DEBUG_DEV_NIC_RX
	1199	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : received unexpected SYN\n",
	1200	__FUNCTION__, this->process->pid, this->trdid, pid, fdid , socket_state_str(socket_state) );
	1201	#endif
[657]	1202	// TODO signal error to user
	1203
	1204	// make an RST request to R2T queue
[663]	1205	socket_put_r2t_request( socket_r2tq_xp,
	1206	TCP_FLAG_RST,
	1207	chdev->channel );
	1208
[657]	1209	// update socket state
[663]	1210	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->state), TCP_STATE_BOUND );
	1211
	1212	break;
[657]	1213	}
	1214
[663]	1215	// [5] check ACK
	1216	if( seg_ack_set == false ) // missing ACK
	1217	{
[657]	1218
[663]	1219	#if DEBUG_DEV_NIC_RX
	1220	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : no ACK flag\n",
	1221	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state) );
	1222	#endif
	1223	// discard segment
[657]	1224	break;
	1225	}
[663]	1226	else if( is_in_window( seg_ack_num,
	1227	socket_tx_una,
	1228	socket_tx_nxt ) == false ) // unacceptable ACK
[657]	1229	{
	1230
[663]	1231	#if DEBUG_DEV_NIC_RX
	1232	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : ACK_NUM %x not in [%x,%x]\n",
	1233	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state),
	1234	seg_ack_num, socket_tx_una, socket_tx_nxt );
	1235	#endif
	1236	// discard segment
	1237	break;
[657]	1238	}
[663]	1239	else // acceptable ack
[657]	1240	{
[663]	1241	// update socket.tx_una
	1242	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_una), seg_ack_num );
[657]	1243
[663]	1244	// update socket.tx_wnd
	1245	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_wnd), seg_window );
[657]	1246
[663]	1247	// check last data byte acknowledged for a SEND command
	1248	if( (socket_tx_todo == 0) &&
	1249	(seg_ack_num == socket_tx_nxt) &&
	1250	(socket_tx_cmd == CMD_TX_SEND) )
[657]	1251	{
[663]	1252	// signal success to TX client thread
	1253	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
[657]	1254	}
	1255	}
	1256
[663]	1257	// [7] handle URG flag TODO ... someday
[657]	1258
[663]	1259	// [8] Move DATA to rx_buf / ACK request to R2T queue / unblock rx_client
	1260	if( seg_data_len )
[657]	1261	{
	1262	if( (socket_state == TCP_STATE_ESTAB) \|\|
	1263	(socket_state == TCP_STATE_FIN_WAIT1) \|\|
	1264	(socket_state == TCP_STATE_FIN_WAIT2) )
	1265	{
	1266	// get number of bytes already stored in rx_buf
	1267	uint32_t status = remote_buf_status( socket_rx_buf_xp );
	1268
	1269	// compute empty space in rx_buf
	1270	uint32_t space = NIC_RX_BUF_SIZE - status;
	1271
[663]	1272	// compute number of bytes to move : min (space , seg_data_len)
	1273	uint32_t nbytes = ( space < seg_data_len ) ? space : seg_data_len;
[657]	1274
	1275	// move payload from k_buf to rx_buf
	1276	remote_buf_put_from_kernel( socket_rx_buf_xp,
	1277	k_buf + seg_hlen,
	1278	nbytes );
[663]	1279	#if DEBUG_DEV_NIC_RX
	1280	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : move %d bytes to rx_buf\n",
	1281	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1282	socket_state_str(socket_state), nbytes );
	1283	#endif
[657]	1284	// update socket.rx_nxt
	1285	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_nxt ),
	1286	socket_rx_nxt + nbytes );
	1287
	1288	// update socket.rx_wnd
	1289	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_wnd ),
[663]	1290	socket_rx_wnd - nbytes );
[657]	1291
[663]	1292	// make an ACK request to R2T queue
	1293	socket_put_r2t_request( socket_r2tq_xp,
	1294	TCP_FLAG_ACK,
	1295	chdev->channel );
[657]	1296
[663]	1297	// check pending RX_RECV command
	1298	if( (socket_rx_valid == true) &&
	1299	(socket_rx_cmd == CMD_RX_RECV) )
[657]	1300	{
[663]	1301	// reset rx_valid
	1302	hal_remote_s32( XPTR(socket_cxy,&socket_ptr->rx_valid), false );
	1303
	1304	// report success to RX client thread
	1305	dev_nic_unblock_rx_client( socket_xp , CMD_STS_SUCCESS );
	1306	#if DEBUG_DEV_NIC_RX
	1307	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : unblock waiting RX client thread\n",
	1308	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1309	socket_state_str(socket_state) );
	1310	#endif
[657]	1311	}
	1312	}
	1313	}
	1314
[663]	1315	// [9] handle FIN flag
	1316	if( socket_state == TCP_STATE_ESTAB )
[657]	1317	{
[663]	1318	if( seg_fin_set ) // received ACK & FIN
[657]	1319	{
[663]	1320
	1321	#if DEBUG_DEV_NIC_RX
	1322	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : FIN-ACK => goes CLOSE_WAIT\n",
	1323	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1324	socket_state_str(socket_state) );
	1325	#endif
	1326	// update socket.rx_nxt when FIN received
	1327	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_nxt ),
	1328	socket_rx_nxt + 1 );
	1329
	1330	// update socket state
	1331	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1332	TCP_STATE_CLOSE_WAIT );
	1333
	1334	// make an ACK request to R2T queue
	1335	socket_put_r2t_request( socket_r2tq_xp,
	1336	TCP_FLAG_ACK,
	1337	chdev->channel );
	1338
	1339	// check pending RX_RECV command
	1340	if( (socket_rx_valid == true) &&
	1341	(socket_rx_cmd == CMD_RX_RECV) )
	1342	{
	1343	// reset rx_valid
	1344	hal_remote_s32( XPTR(socket_cxy,&socket_ptr->rx_valid), false );
	1345
	1346	// report error to RX client thread
	1347	dev_nic_unblock_rx_client( socket_xp , CMD_STS_EOF );
	1348	#if DEBUG_DEV_NIC_RX
	1349	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : unblock RX client waiting on RECV\n",
	1350	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1351	socket_state_str(socket_state) );
	1352	#endif
	1353	}
[657]	1354	}
[663]	1355	}
	1356	else if( socket_state == TCP_STATE_FIN_WAIT1 )
	1357	{
	1358	if( seg_fin_set ) // received ACK & FIN
	1359	{
[657]	1360
[663]	1361	#if DEBUG_DEV_NIC_RX
	1362	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : FIN-ACK => goes CLOSING\n",
	1363	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1364	socket_state_str(socket_state) );
	1365	#endif
	1366	// update socket.rx_nxt when FIN received
	1367	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_nxt ),
	1368	socket_rx_nxt + 1 );
	1369
	1370	// update socket state
	1371	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1372	TCP_STATE_CLOSING );
	1373
[657]	1374	// make an ACK request to R2T queue
[663]	1375	socket_put_r2t_request( socket_r2tq_xp,
	1376	TCP_FLAG_ACK,
	1377	chdev->channel );
	1378	}
	1379	else // received ACK only
	1380	{
[657]	1381
[663]	1382	#if DEBUG_DEV_NIC_RX
	1383	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : only ACK => goes FIN_WAIT2\n",
	1384	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1385	socket_state_str(socket_state) );
	1386	#endif
	1387	// update socket state
	1388	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1389	TCP_STATE_FIN_WAIT2 );
	1390	}
	1391	}
	1392	else if( socket_state == TCP_STATE_FIN_WAIT2 )
	1393	{
	1394	if( seg_fin_set ) // received ACK & FIN
	1395	{
	1396
	1397	#if DEBUG_DEV_NIC_RX
	1398	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s : FIN-ACK => goes CLOSED / unblock client\n",
	1399	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	1400	socket_state_str(socket_state) );
	1401	#endif
	1402	// update socket.rx_nxt when FIN received
[657]	1403	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_nxt ),
	1404	socket_rx_nxt + 1 );
	1405
[663]	1406	// update socket.state
	1407	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1408	TCP_STATE_CLOSED ); // TODO change to TIME_WAIT
[657]	1409
[663]	1410	// make an ACK request to R2T queue
	1411	socket_put_r2t_request( socket_r2tq_xp,
	1412	TCP_FLAG_ACK,
	1413	chdev->channel );
	1414
	1415	// report success to TX client thread
	1416	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
[657]	1417
[663]	1418	// TODO start the MSL timer / turn off others timers
	1419
[657]	1420	}
[663]	1421	}
	1422	else if( socket_state == TCP_STATE_CLOSING ) // received ACK
	1423	{
	1424	// update socket.state
	1425	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1426	TCP_STATE_CLOSED ); // todo change to TIME_WAIT
	1427
	1428	// TODO start the MSL timer / turn off others timers
	1429
	1430	}
	1431	else if( socket_state == TCP_STATE_TIME_WAIT )
	1432	{
	1433	// TODO wait msl_time_out before unblocking TX thread
	1434
	1435	// update socket.state when ACK received
	1436	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1437	TCP_STATE_CLOSED );
	1438
	1439	// unblock TX client thead for success
	1440	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
	1441	}
	1442	else if( socket_state == TCP_STATE_CLOSE_WAIT )
	1443	{
	1444	// do nothing
	1445	}
	1446	else if( socket_state == TCP_STATE_LAST_ACK )
	1447	{
	1448	// update socket.state when ACK received
	1449	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	1450	TCP_STATE_CLOSED );
	1451
	1452	// unblock TX client thead for success
	1453	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
	1454	}
	1455	} // end case connecteded states
[657]	1456	} // end switch socket state
	1457
[663]	1458	// release the lock protecting socket state
	1459	remote_queuelock_release( socket_lock_xp );
[657]	1460
[663]	1461	return;
[657]	1462
[663]	1463	} // end if attached socket
	1464
	1465	// 4. scan the list of listening sockets
	1466	listening_match = false;
	1467
	1468	// get pointers on NIC_RX[0] chdev
	1469	xptr_t rx0_chdev_xp = chdev_dir.nic_rx[0];
	1470	chdev_t * rx0_chdev_ptr = GET_PTR( rx0_chdev_xp );
	1471	cxy_t rx0_chdev_cxy = GET_CXY( rx0_chdev_xp );
	1472
	1473	// build extended pointers on list of listening sockets
	1474	xptr_t rx0_root_xp = XPTR( rx0_chdev_cxy , &rx0_chdev_ptr->ext.nic.root );
	1475	xptr_t rx0_lock_xp = XPTR( rx0_chdev_cxy , &rx0_chdev_ptr->ext.nic.lock );
	1476
	1477	// take the lock protecting the list of listening sockets
	1478	remote_busylock_acquire( rx0_lock_xp );
	1479
	1480	// scan the xlist of listening socket
	1481	XLIST_FOREACH( rx0_root_xp , iter_xp )
	1482	{
	1483	// get socket cluster and local pointer
	1484	socket_xp = XLIST_ELEMENT( iter_xp , socket_t , rx_list );
	1485	socket_ptr = GET_PTR( socket_xp );
	1486	socket_cxy = GET_CXY( socket_xp );
	1487
	1488	// get relevant socket type and state
	1489	socket_type = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->type ));
	1490	socket_state = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->state ));
	1491
	1492	// check socket type and state
	1493	assert( (socket_type == SOCK_STREAM ) , "illegal socket type" );
	1494	assert( (socket_state == TCP_STATE_LISTEN ) , "illegal socket state" );
	1495
	1496	// get relevant socket infos for matching
	1497	socket_local_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_addr ));
	1498	socket_local_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_port ));
	1499
	1500	// compute matching condition for a listening socket
	1501	listening_match = (socket_local_addr == seg_local_addr) &&
	1502	(socket_local_port == seg_local_port);
	1503
	1504	// exit loop if matching
	1505	if( listening_match )
	1506	{
	1507
	1508	#if DEBUG_DEV_NIC_RX
	1509	fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ) );
	1510	pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ) );
	1511	if( cycle > DEBUG_DEV_NIC_RX )
	1512	printk("\n[%s] thread[%x,%x] matching listening socket[%d,%d] / state %s\n",
	1513	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, socket_state_str(socket_state) );
	1514	#endif
	1515	break;
	1516	}
	1517	} // end loop on listening sockets
	1518
	1519	// release the lock protecting the list of listening sockets
	1520	remote_busylock_release( rx0_lock_xp );
	1521
	1522	// 5. handle TCP segment for a matching listening socket
	1523	if( listening_match )
	1524	{
	1525	// The actions depend on the received segment flags
	1526	// - discard segment for RST or ACK
	1527	// - update socket state & remote IP address,
	1528	// register connect request in socket CRQ queue,
	1529	// and unblock client thread for SYN
	1530
	1531	// discard segment if RST flag
	1532	if( seg_rst_set )
	1533	{
	1534
	1535	#if DEBUG_DEV_NIC_RX
	1536	if( cycle > DEBUG_DEV_NIC_RX )
	1537	printk("\n[%s] thread[%x,%x] for listening socket[%x,%d] : received RST\n",
	1538	__FUNCTION__, this->process->pid, this->trdid, pid, fdid );
	1539	#endif
	1540	return;
	1541	}
	1542
	1543	// discard segment if ACK flag
	1544	if( seg_ack_set )
	1545	{
	1546
	1547	#if DEBUG_DEV_NIC_RX
	1548	if( cycle > DEBUG_DEV_NIC_RX )
	1549	printk("\n[%s] thread[%x,%x] for listening socket[%x,%d] : received ACK\n",
	1550	__FUNCTION__, this->process->pid, this->trdid, pid, fdid );
	1551	#endif
	1552	return;
	1553	}
	1554
	1555	// SYN flag == CONNECT request / seq_num cannot be wrong
	1556	if( seg_syn_set )
	1557	{
	1558	// build extended pointer on listening socket CRQ
	1559	socket_crqq_xp = XPTR( socket_cxy , &socket_ptr->crqq );
	1560
	1561	// try to register request into CRQ queue
	1562	error = socket_put_crq_request( socket_crqq_xp,
	1563	seg_remote_addr,
	1564	seg_remote_port,
	1565	seg_seq_num,
	1566	seg_window );
	1567
	1568	if ( error ) // CRQ full
	1569	{
	1570
	1571	#if DEBUG_DEV_NIC_RX
	1572	if( cycle > DEBUG_DEV_NIC_RX )
	1573	printk("\n[%s] thread[%x,%x] listening socket[%x,%d] CRQ full => send RST\n",
	1574	__FUNCTION__, this->process->pid, this->trdid, pid, fdid );
	1575	#endif
	1576	// make an RST request to R2T queue
	1577	socket_put_r2t_request( socket_r2tq_xp,
	1578	TCP_FLAG_RST,
	1579	chdev->channel );
	1580	}
	1581	else // new connection request registered in CRQ
	1582	{
	1583
	1584	#if DEBUG_DEV_NIC_RX
	1585	if( cycle > DEBUG_DEV_NIC_RX )
	1586	printk("\n[%s] thread[%x,%x] for listening socket[%x,%d] : register request in CRQ\n",
	1587	__FUNCTION__, this->process->pid, this->trdid, pid, fdid );
	1588	#endif
	1589	// check pending RX_ACCEPT command
	1590	if( (hal_remote_l32(XPTR(socket_cxy,&socket_ptr->rx_valid)) == true) &&
	1591	(hal_remote_l32(XPTR(socket_cxy,&socket_ptr->rx_cmd)) == CMD_RX_ACCEPT) )
	1592	{
	1593	// reset rx_valid
	1594	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->rx_valid ), false );
	1595
	1596	// report success to RX client thread
	1597	dev_nic_unblock_rx_client( socket_xp , CMD_STS_SUCCESS );
	1598
	1599	#if DEBUG_DEV_NIC_RX
	1600	if( cycle > DEBUG_DEV_NIC_RX )
	1601	printk("\n[%s] thread[%x,%x] for listening socket[%x,%d] unblock RX client thread\n",
	1602	__FUNCTION__, this->process->pid, this->trdid, pid, fdid );
	1603	#endif
	1604	}
	1605	} // end register request in CRQ
	1606	} // end if SYN
	1607
	1608	return;
	1609
	1610	} // end if listening_match
	1611
	1612	// 6. no socket found => discard segment
	1613
	1614	#if DEBUG_DEV_NIC_RX
	1615	if( cycle > DEBUG_DEV_NIC_RX )
	1616	printk("\n[%s] thread[%x,%x] exit failure : no socket found => discard segment\n",
	1617	__FUNCTION__, this->process->pid, this->trdid );
	1618	#endif
	1619
[657]	1620	} // end dev_nic_rx_handle_tcp_segment()
	1621
	1622
	1623	/////////////////////////////////////////
	1624	void dev_nic_rx_server( chdev_t * chdev )
	1625	{
	1626	uint8_t k_buf[2048]; // kernel buffer for one ETH/IP/UDP packet
	1627	uint32_t pkt_src_addr; // packet source IP address
	1628	uint32_t pkt_dst_addr; // packet destination IP address
	1629	uint32_t trsp_protocol; // transport protocol (TCP / UDP)
	1630	uint32_t eth_length; // size of Ethernet packet (bytes)
	1631	uint32_t ip_length; // size of IP packet in bytes
	1632	error_t error;
	1633
[663]	1634	thread_t * this = CURRENT_THREAD;
[657]	1635
[663]	1636	// check thread can yield
	1637	thread_assert_can_yield( this , __FUNCTION__ );
	1638
[657]	1639	// check chdev direction and type
	1640	assert( (chdev->func == DEV_FUNC_NIC) && (chdev->is_rx == true) ,
	1641	"illegal chdev type or direction" );
	1642
[663]	1643	#if DEBUG_DEV_NIC_RX
	1644	uint32_t cycle = (uint32_t)hal_get_cycles();
	1645	if( cycle > DEBUG_DEV_NIC_RX )
	1646	printk("\n[%s] thread[%x,%x] starts / cycle %d\n",
	1647	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1648	#endif
[565]	1649
[663]	1650	// get extended pointers on server tread and chdev
	1651	xptr_t thread_xp = XPTR( local_cxy , this );
	1652	xptr_t chdev_xp = XPTR( local_cxy , chdev );
	1653
[657]	1654	while( 1 )
	1655	{
[663]	1656	// call NIC driver to move one packet from NIC_RX queue to kernel buffer
	1657	this->nic_cmd.dev_xp = chdev_xp;
	1658	this->nic_cmd.type = NIC_CMD_READ;
	1659	this->nic_cmd.buffer = k_buf;
	1660	chdev->cmd( XPTR( local_cxy , this ) );
	1661
	1662	// get packet length
	1663	eth_length = this->nic_cmd.status;
	1664
	1665	// check success
	1666	if( eth_length == 0 ) // queue empty => block and deschedule
[657]	1667	{
[663]	1668
	1669	#if DEBUG_DEV_NIC_RX
	1670	cycle = (uint32_t)hal_get_cycles();
	1671	if( DEBUG_DEV_NIC_RX < cycle )
	1672	printk("\n[%s] thread[%x,%x] NIC_RX_QUEUE empty => blocks on <ISR> / cycle %d\n",
	1673	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1674	#endif
	1675	// enable NIC_RX IRQ
	1676	dev_pic_enable_irq( this->core->lid , chdev_xp );
	1677
	1678	// block and deschedule
	1679	thread_block( thread_xp , THREAD_BLOCKED_ISR );
	1680	sched_yield("client blocked on NIC_TX queue full");
	1681
	1682	// disable NIC-RX IRQ
	1683	dev_pic_disable_irq( this->core->lid , chdev_xp );
	1684
	1685	#if DEBUG_DEV_NIC_RX
	1686	cycle = (uint32_t)hal_get_cycles();
	1687	if( DEBUG_DEV_NIC_RX < cycle )
	1688	printk("\n[%s] thread[%x,%x] resumes / cycle %d\n",
	1689	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1690	#endif
	1691
[657]	1692	}
[663]	1693	else // success => handle packet
[657]	1694	{
[1]	1695
[663]	1696	#if DEBUG_DEV_NIC_RX
	1697	cycle = (uint32_t)hal_get_cycles();
	1698	if( DEBUG_DEV_NIC_RX < cycle )
	1699	dev_nic_packet_display( false, // is_tx
	1700	this->process->pid,
	1701	this->trdid,
	1702	cycle,
	1703	k_buf );
	1704	#endif
	1705
[657]	1706	// analyse the ETH header
	1707	error = dev_nic_rx_check_eth( k_buf,
	1708	&ip_length );
[1]	1709
[657]	1710	// discard packet if error reported by Ethernet layer
[663]	1711	if( error )
	1712	{
[1]	1713
[663]	1714	#if DEBUG_DEV_NIC_RX
	1715	cycle = (uint32_t)hal_get_cycles();
	1716	if( DEBUG_DEV_NIC_RX < cycle )
	1717	printk("\n[%s] thread[%x,%x] discard ETH packet / cycle %d\n",
	1718	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1719	#endif
	1720	continue;
	1721	}
	1722
	1723	#if (DEBUG_DEV_NIC_RX & 1)
	1724	cycle = (uint32_t)hal_get_cycles();
	1725	if( DEBUG_DEV_NIC_RX < cycle )
	1726	printk("\n[%s] thread[%x,%x] successfully checked ETH packet / cycle %d\n",
	1727	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1728	#endif
[657]	1729	// analyse the IP header
	1730	error = dev_nic_rx_check_ip( k_buf + ETH_HEAD_LEN,
	1731	ip_length,
	1732	&pkt_src_addr,
	1733	&pkt_dst_addr,
	1734	&trsp_protocol );
[1]	1735
[657]	1736	// discard packet if error reported by IP layer
[663]	1737	if( error )
	1738	{
[1]	1739
[663]	1740	#if DEBUG_DEV_NIC_RX
	1741	cycle = (uint32_t)hal_get_cycles();
	1742	if( DEBUG_DEV_NIC_RX < cycle )
	1743	printk("\n[%s] thread[%x,%x] discarded IP packet / cycle %d\n",
	1744	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1745	#endif
	1746	continue;
	1747	}
	1748
	1749	#if (DEBUG_DEV_NIC_RX & 1 )
	1750	cycle = (uint32_t)hal_get_cycles();
	1751	if( (DEBUG_DEV_NIC_RX < cycle) && (trsp_protocol == PROTOCOL_UDP) )
	1752	printk("\n[%s] thread[%x,%x] successfully checked UDP packet / cycle %d\n",
	1753	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1754	if( (DEBUG_DEV_NIC_RX < cycle) && (trsp_protocol == PROTOCOL_TCP) )
	1755	printk("\n[%s] thread[%x,%x] successfully checked TCP segment / cycle %d\n",
	1756	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1757	#endif
	1758
[657]	1759	// call relevant transport protocol
	1760	if( trsp_protocol == PROTOCOL_UDP )
	1761	{
	1762	dev_nic_rx_handle_udp_packet( chdev,
	1763	k_buf + ETH_HEAD_LEN + IP_HEAD_LEN,
	1764	ip_length - IP_HEAD_LEN,
	1765	pkt_src_addr,
	1766	pkt_dst_addr );
	1767	}
	1768	else if ( trsp_protocol == PROTOCOL_TCP)
	1769	{
	1770	dev_nic_rx_handle_tcp_segment( chdev,
	1771	k_buf + ETH_HEAD_LEN + IP_HEAD_LEN,
	1772	ip_length - IP_HEAD_LEN,
	1773	pkt_src_addr,
	1774	pkt_dst_addr );
	1775	}
[663]	1776	else // discard packet if unsupported transport protocol
	1777	{
	1778
	1779	#if DEBUG_DEV_NIC_RX
	1780	cycle = (uint32_t)hal_get_cycles();
	1781	if( DEBUG_DEV_NIC_RX < cycle )
	1782	printk("\n[%s] thread[%x,%x] discarded unsupported transport protocol %d\n",
	1783	__FUNCTION__, this->process->pid, this->trdid, trsp_protocol, cycle );
	1784	#endif
	1785	continue;
	1786	}
[657]	1787	}
	1788	} // end of while loop
	1789	} // end dev_nic_rx_server()
	1790
	1791
	1792
	1793
	1794	///////////////////////////////////////////////////////////////////////////////////////////
	1795	// Functions used by the NIC_TX server thread
	1796	///////////////////////////////////////////////////////////////////////////////////////////
	1797
	1798	///////////////////////////////////////////////////////////////////////////////////////////
[663]	1799	// This static function is called by the dev_nic_tx_build_packet() function.
[657]	1800	// It moves one ETH/IP/UDP packet from the kernel buffer identified by the <buffer> and
	1801	// <length> arguments to the NIC_TX_QUEUE identified the <chdev> argument.
[663]	1802	// It blocks and deschedules on the BLOCKED_ISR condition if the queue is full.
[657]	1803	///////////////////////////////////////////////////////////////////////////////////////////
	1804	// @ chdev : [in] local pointer on NIC_TX chdev.
[663]	1805	// @ k_buf : [in] pointer on a local kernel buffer (2K bytes).
[657]	1806	// @ length : [in] actual Ethernet packet length in bytes.
	1807	///////////////////////////////////////////////////////////////////////////////////////////
[663]	1808	static void dev_nic_tx_move_packet( chdev_t * chdev,
	1809	uint8_t * k_buf,
	1810	uint32_t length )
[657]	1811	{
	1812	thread_t * this = CURRENT_THREAD;
	1813
	1814	// get extended pointers on server tread and chdev
	1815	xptr_t thread_xp = XPTR( local_cxy , this );
	1816	xptr_t chdev_xp = XPTR( local_cxy , chdev );
	1817
	1818	// check thread can yield
[663]	1819	thread_assert_can_yield( this , __FUNCTION__ );
[657]	1820
[663]	1821	#if (DEBUG_DEV_NIC_TX & 1)
[657]	1822	uint32_t cycle = (uint32_t)hal_get_cycles();
[663]	1823	if( DEBUG_DEV_NIC_TX < cycle )
	1824	printk("\n[%s] thread[%x,%x] enter / buf %x / length %d / cycle %d\n",
	1825	__FUNCTION__, this->process->pid, this->trdid, k_buf, length, cycle );
[657]	1826	#endif
	1827
[663]	1828	// initialize WRITE command in server thread descriptor
	1829	this->nic_cmd.dev_xp = chdev_xp;
	1830	this->nic_cmd.type = NIC_CMD_WRITE;
	1831	this->nic_cmd.buffer = k_buf;
	1832	this->nic_cmd.length = length;
	1833
[657]	1834	while( 1 )
[1]	1835	{
[663]	1836	// call driver to move TX packet
	1837	chdev->cmd( thread_xp );
	1838
	1839	// exit while if success
	1840	if( this->nic_cmd.status == length ) // exit while & return if success
[657]	1841	{
[663]	1842
	1843	#if (DEBUG_DEV_NIC_TX & 1)
	1844	cycle = (uint32_t)hal_get_cycles();
	1845	if( DEBUG_DEV_NIC_TX < cycle )
	1846	printk("\n[%s] thread[%x,%x] exit SUCCESS / cycle %d\n",
	1847	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1848	#endif
	1849	break;
[657]	1850	}
[663]	1851	else // block and deschedule if queue full
[657]	1852	{
[1]	1853
[663]	1854	#if (DEBUG_DEV_NIC_TX & 1)
	1855	cycle = (uint32_t)hal_get_cycles();
	1856	if( DEBUG_DEV_NIC_TX < cycle )
	1857	printk("\n[%s] thread[%x,%x] NIC_TX_QUEUE full => blocks on ISR / cycle %d\n",
	1858	__FUNCTION__, this->process->pid, this->trdid, cycle );
	1859	#endif
	1860	// enable NIC_TX IRQ
	1861	dev_pic_enable_irq( this->core->lid , chdev_xp );
	1862
	1863	// TX server thread blocks and deschedules
[657]	1864	thread_block( thread_xp , THREAD_BLOCKED_ISR );
	1865	sched_yield("client blocked on NIC_TX queue full");
[1]	1866
[657]	1867	// disable NIC-TX IRQ
[663]	1868	dev_pic_disable_irq( this->core->lid , chdev_xp );
[1]	1869
[663]	1870	#if (DEBUG_DEV_NIC_TX & 1)
[437]	1871	cycle = (uint32_t)hal_get_cycles();
[663]	1872	if( DEBUG_DEV_NIC_TX < cycle )
	1873	printk("\n[%s] thread[%x,%x] resumes / cycle %d\n",
	1874	__FUNCTION__, this->process->pid, this->trdid, cycle );
[437]	1875	#endif
[663]	1876	}
	1877	}
[657]	1878	} // end dev_nic_tx_move_packet()
[1]	1879
[657]	1880	///////////////////////////////////////////////////////////////////////////////////////////
	1881	// This static function is called by the dev_nic_tx_server() function to build an UDP
	1882	// header in the kernel buffer defined by the <k_buf> arguement, as specified by the
	1883	// <socket_xp> argument. The <length> argument defines the number of bytes in payload.
	1884	// It set the "src_port", "dst_port", "total_length" and "checksum" fields in UDP header.
	1885	// The payload must be previouly loaded in the pernel buffer.
	1886	///////////////////////////////////////////////////////////////////////////////////////////
	1887	// @ k_buf : [in] pointer on first byte of UDP header in kernel buffer.
	1888	// @ socket_xp : [in] extended pointer on socket.
	1889	// @ length : [in] number of bytes in payload.
	1890	///////////////////////////////////////////////////////////////////////////////////////////
[663]	1891	static void dev_nic_tx_build_udp_header( uint8_t * k_buf,
	1892	xptr_t socket_xp,
	1893	uint32_t length )
[657]	1894	{
	1895	uint16_t checksum; // checksum value
	1896	uint32_t total_length; // total UDP packet length
	1897	uint32_t local_addr; // local IP address
	1898	uint32_t remote_addr; // remote IP address
	1899	uint32_t local_port; // local port
	1900	uint32_t remote_port; // remote port
[1]	1901
[657]	1902	// get socket cluster an local pointer
	1903	socket_t * socket_ptr = GET_PTR( socket_xp );
	1904	cxy_t socket_cxy = GET_CXY( socket_xp );
	1905
	1906	// get relevant infos from socket
	1907	local_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_addr ));
	1908	remote_addr = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_addr ));
	1909	local_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->local_port ));
	1910	remote_port = hal_remote_l32(XPTR(socket_cxy , &socket_ptr->remote_port ));
	1911
	1912	// compute UDP packet total length
	1913	total_length = length + UDP_HEAD_LEN;
	1914
	1915	// set src_port and dst_port in header
	1916	k_buf[0] = local_port >> 8;
	1917	k_buf[1] = local_port;
	1918	k_buf[2] = remote_port >> 8;
	1919	k_buf[3] = remote_port;
	1920
	1921	// set packet length in header
	1922	k_buf[4] = total_length >> 8;
	1923	k_buf[5] = total_length;
	1924
	1925	// compute UDP packet checksum
	1926	checksum = dev_nic_udp_checksum( k_buf , total_length );
	1927
	1928	// set checksum
	1929	k_buf[6] = checksum >> 8;
	1930	k_buf[7] = checksum;
	1931
	1932	} // end dev_nic_tx_build_udp_header()
	1933
	1934	///////////////////////////////////////////////////////////////////////////////////////////
	1935	// This static function is called by the dev_nic_tx_server() function.
	1936	// It builds a TCP header in the kernel buffer defined by the <k_buf> argument.
	1937	// The payload must have been previouly registered in this buffer.
	1938	// The "local_addr", "local_port", "remote_addr", "remote_port", seq_num", "ack_num",
	1939	// and "window" fields are obtained from the <socket_xp> argument.
	1940	// The <length> argument defines the number of bytes in payload, and the <flags> argument
	1941	// defines the flags to be set in TCP header.
	1942	///////////////////////////////////////////////////////////////////////////////////////////
	1943	// @ k_buf : [in] pointer on first byte of TCP header in kernel buffer.
[663]	1944	// @ socket_xp : [in] extended pointer on socket.
[657]	1945	// @ length : [in] number of bytes in payload.
	1946	// @ flags : [in] flags to be set in TCP header.
	1947	///////////////////////////////////////////////////////////////////////////////////////////
[663]	1948	static void dev_nic_tx_build_tcp_header( uint8_t * k_buf,
	1949	xptr_t socket_xp,
	1950	uint32_t length,
	1951	uint8_t flags )
[657]	1952	{
	1953	uint16_t checksum; // global segment checksum
	1954	uint32_t total_length; // total UDP packet length
	1955	uint32_t src_addr; // local IP address
	1956	uint32_t dst_addr; // remote IP address
	1957	uint16_t src_port; // local port
	1958	uint16_t dst_port; // remote port
	1959	uint32_t seq_num; // first byte of segment in TX stream
	1960	uint32_t ack_num; // next expected byte in RX stream
[663]	1961	uint32_t window; // window of accepted segments in RX stream
[657]	1962
	1963	// get socket cluster an local pointer
	1964	socket_t * sock_ptr = GET_PTR( socket_xp );
	1965	cxy_t sock_cxy = GET_CXY( socket_xp );
	1966
	1967	// get relevant infos from socket
	1968	src_addr = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->local_addr ));
	1969	dst_addr = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->remote_addr ));
	1970	src_port = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->local_port ));
	1971	dst_port = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->remote_port ));
	1972	seq_num = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->tx_nxt ));
	1973	ack_num = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->rx_nxt ));
	1974	window = hal_remote_l32(XPTR( sock_cxy , &sock_ptr->rx_wnd ));
	1975
	1976	// compute TCP segment total length
	1977	total_length = length + TCP_HEAD_LEN;
	1978
	1979	// set "src_port" and "dst_port"
	1980	k_buf[0] = src_port >> 8;
	1981	k_buf[1] = src_port;
	1982	k_buf[2] = dst_port >> 8;
	1983	k_buf[3] = dst_port;
	1984
	1985	// set "seq_num"
	1986	k_buf[4] = seq_num >> 24;
	1987	k_buf[5] = seq_num >> 16;
	1988	k_buf[6] = seq_num >> 8;
	1989	k_buf[7] = seq_num;
	1990
	1991	// set "ack_num"
	1992	k_buf[8] = ack_num >> 24;
	1993	k_buf[9] = ack_num >> 16;
	1994	k_buf[10] = ack_num >> 8;
	1995	k_buf[11] = ack_num;
	1996
	1997	// set "hlen"
	1998	k_buf[12] = 5;
	1999
	2000	// set "flags"
	2001	k_buf[13] = flags & 0x3F;
	2002
	2003	// set "window"
	2004	k_buf[14] = window >> 8;
	2005	k_buf[15] = window;
	2006
	2007	// reset "checksum"
	2008	k_buf[16] = 0;
	2009	k_buf[17] = 0;
	2010
	2011	// set "urgent_ptr"
	2012	k_buf[18] = 0;
	2013	k_buf[19] = 0;
	2014
	2015	// compute TCP segment checksum
	2016	checksum = dev_nic_tcp_checksum( k_buf,
	2017	total_length,
	2018	src_addr,
	2019	dst_addr );
	2020	// set "checksum"
	2021	k_buf[16] = checksum >> 8;
	2022	k_buf[17] = checksum;
	2023
	2024	} // end dev_nic_tx_build_tcp_header()
	2025
	2026
	2027	///////////////////////////////////////////////////////////////////////////////////////////
	2028	// This static function is called by the dev_nic_tx_server() function.
	2029	// It builds the IP header in the 20 first bytes of <buffer>.
	2030	///////////////////////////////////////////////////////////////////////////////////////////
	2031	// @ buffer : pointer on first byte of IP header in kernel buffer
	2032	// @ src_addr : source IP address.
	2033	// @ dst_addr : destination IP address.
	2034	// @ length : number of bytes in IP packet payload.
	2035	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2036	static void dev_nic_tx_build_ip_header( uint8_t * buffer,
	2037	uint32_t src_addr,
	2038	uint32_t dst_addr,
	2039	uint8_t protocol,
	2040	uint16_t length )
[657]	2041	{
	2042	uint16_t hcs;
	2043
	2044	uint16_t total = length + IP_HEAD_LEN;
	2045
	2046	buffer[0] = 0x45; // IPV4 / IHL = 20 bytes
	2047	buffer[1] = 0; // DSCP / ECN
	2048	buffer[2] = total >> 8;
	2049	buffer[3] = total;
	2050
	2051	buffer[4] = 0x40; // Don't Fragment
	2052	buffer[5] = 0;
	2053	buffer[6] = 0;
	2054	buffer[7] = 0;
	2055
	2056	buffer[8] = 0xFF; // TTL
[663]	2057	buffer[9] = protocol; // transport protocol
[657]	2058
	2059	buffer[12] = src_addr >> 24;
	2060	buffer[13] = src_addr >> 16;
	2061	buffer[14] = src_addr >> 8;
	2062	buffer[15] = src_addr;
	2063
	2064	buffer[16] = dst_addr >> 24;
	2065	buffer[17] = dst_addr >> 16;
	2066	buffer[18] = dst_addr >> 8;
	2067	buffer[19] = dst_addr;
	2068
	2069	// compute IP header checksum
	2070	hcs = dev_nic_ip_checksum( buffer );
	2071
	2072	// set checksum
	2073	buffer[10] = hcs >> 8;
	2074	buffer[11] = hcs;
	2075
	2076	} // end dev_nic_tx_build_ip_header
	2077
	2078	///////////////////////////////////////////////////////////////////////////////////////////
	2079	// This static function is called by the dev_nic_tx_server() function.
	2080	// It builds the Ethernet header in the 14 first bytes of <buffer>.
	2081	///////////////////////////////////////////////////////////////////////////////////////////
	2082	// @ buffer : pointer on first byte of Ethernet header in kernel buffer
	2083	// @ src_mac_54 : two MSB bytes in source MAC address.
	2084	// @ src_mac_32 : two MED bytes in source MAC address.
	2085	// @ src_mac_10 : two LSB bytes in source MAC address.
	2086	// @ dst_mac_54 : two MSB bytes in destination MAC address.
	2087	// @ dst_mac_32 : two MED bytes in destination MAC address.
	2088	// @ dst_mac_10 : two LSB bytes in destination MAC address.
	2089	// @ length : number of bytes in Ethernet frame payload.
	2090	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2091	static void dev_nic_tx_build_eth_header( uint8_t * buffer,
	2092	uint8_t src_mac_5,
	2093	uint8_t src_mac_4,
	2094	uint8_t src_mac_3,
	2095	uint8_t src_mac_2,
	2096	uint8_t src_mac_1,
	2097	uint8_t src_mac_0,
	2098	uint8_t dst_mac_5,
	2099	uint8_t dst_mac_4,
	2100	uint8_t dst_mac_3,
	2101	uint8_t dst_mac_2,
	2102	uint8_t dst_mac_1,
	2103	uint8_t dst_mac_0,
	2104	uint32_t length )
[657]	2105	{
[663]	2106	buffer[0] = dst_mac_5;
	2107	buffer[1] = dst_mac_4;
	2108	buffer[2] = dst_mac_3;
	2109	buffer[3] = dst_mac_2;
	2110	buffer[4] = dst_mac_1;
	2111	buffer[5] = dst_mac_0;
[657]	2112
[663]	2113	buffer[6] = src_mac_5;
	2114	buffer[7] = src_mac_4;
	2115	buffer[8] = src_mac_3;
	2116	buffer[9] = src_mac_2;
	2117	buffer[10] = src_mac_1;
	2118	buffer[11] = src_mac_0;
[657]	2119
	2120	buffer[12] = length >> 8;
	2121	buffer[13] = length;
	2122
	2123	} // end dev_nic_tx_build_eth_header()
	2124
	2125	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2126	// This static function is called by the dev_nic_tx_server() function to handle one TX
	2127	// command, or one R2T request, as defined by the <cmd_valid> and <r2t_valid> arguments,
	2128	// for the socket identified by the <socket_xp> argument. It builds an ETH/IP/UDP packet
	2129	// or ETH/IP/TCP segment, in the buffer defined by the <k_buf> argument, and registers
	2130	// it in the NIC_TX queue defined by the <chdev> argument.
	2131	// For a TCP header, the "seq_num", ack_num", and "window" fiels are defined by the
	2132	// "socket.tx_next", "socket.rx_next" and "socket.rx_wnd" fields respectively.
	2133	// It updates the "socket.state", "socket.tx_nxt", "socket.r2tq", and "socket.crqq"
	2134	// The supported TX command types are CONNECT / ACCEPT / SEND / CLOSE.
	2135	// fields as required by the command type.
	2136	// - For an UDP socket, it reset the "socket.tx_valid" field, and unblock the client
	2137	// thread when the packet has been sent, or when an error must be reported.
	2138	// - For a TCP socket, it reset the "socket.tx_valid" field when the segment has been
	2139	// sent, but does not unblocks the client thread, that will be unblocqued by the
	2140	// NIC_RX thread when the TX command is fully completed.
[657]	2141	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2142	// To build a packet, it makes the following actions:
[657]	2143	// 1) it takes the lock protecting the socket state.
[663]	2144	// 2) it get the command arguments from socket descriptor.
	2145	// 3) it build an UDP packet or a TCP segment, depending on command type and socket state.
	2146	// 4) it updates the socket state.
	2147	// 5) it releases the lock protecting the socket.
	2148	// 6) it build the IP header.
	2149	// 7) it build the ETH header.
	2150	// 8) it copies the packet in the NIC_TX queue.
[657]	2151	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2152	// @ cmd_state : [in] TX command valid in socket descriptor.
	2153	// @ r2t_valid : [in] R2T request valid in command descriptor.
[657]	2154	// @ socket_xp : [in] extended pointer on client socket.
	2155	// @ k_buf : [in] local pointer on kernel buffer (2 Kbytes).
	2156	// @ chdev : [in] local pointer on NIC_RX chdev.
	2157	///////////////////////////////////////////////////////////////////////////////////////////
[663]	2158	static void dev_nic_tx_build_packet( bool_t cmd_valid,
	2159	bool_t r2t_valid,
	2160	xptr_t socket_xp,
	2161	uint8_t * k_buf,
	2162	chdev_t * chdev )
[657]	2163	{
	2164	socket_t * socket_ptr;
	2165	cxy_t socket_cxy;
	2166	xptr_t client_xp; // extended pointer on client thread
[663]	2167	uint32_t cmd_type; // NIC command type
	2168	uint8_t * tx_buf; // local pointer on kernel buffer for payload
	2169	uint32_t len; // tx_buf length (bytes)
[657]	2170	uint32_t todo; // number of bytes not yet sent
	2171	uint32_t socket_type; // socket type (UDP/TCP)
	2172	uint32_t socket_state; // socket state
	2173	xptr_t socket_lock_xp; // extended pointer on socket lock
	2174	xptr_t socket_r2tq_xp; // extended pointer on R2T queue
	2175	uint32_t src_ip_addr; // source IP address
	2176	uint32_t dst_ip_addr; // destination IP address
[663]	2177	uint32_t tx_nxt; // next sequence number in TX stream
[657]	2178	uint32_t nbytes; // number of bytes in UDP/TCP packet payload
[663]	2179	uint8_t * k_trsp_base; // pointer on UDP/TCP packet in kernel buffer
[657]	2180	uint32_t trsp_length; // length of TCP/UDP packet
[663]	2181	uint8_t trsp_protocol; // transport protocol type (UDP/TCP)
[657]	2182	uint8_t r2t_flags; // flags defined by one R2T queue request
	2183	bool_t do_send; // build & send a packet when true
	2184
	2185	// get socket cluster and local pointer
	2186	socket_cxy = GET_CXY( socket_xp );
	2187	socket_ptr = GET_PTR( socket_xp );
[663]	2188
	2189	#if DEBUG_DEV_NIC_TX
	2190	thread_t * this = CURRENT_THREAD;;
	2191	uint32_t cycle = (uint32_t)hal_get_cycles();
	2192	uint32_t fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ));
	2193	uint32_t pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ));
	2194	if( cycle > DEBUG_DEV_NIC_TX )
	2195	printk("\n[%s] thread[%x,%x] enter for socket[%x,%d] : cmd_valid %d / r2t_valid %d / cycle %d\n",
	2196	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, cmd_valid, r2t_valid, cycle );
	2197	#endif
	2198
	2199	// build extended pointers on socket lock and r2t queue
	2200	socket_lock_xp = XPTR( socket_cxy , &socket_ptr->lock );
[657]	2201	socket_r2tq_xp = XPTR( socket_cxy , &socket_ptr->r2tq );
	2202
	2203	// 1. take lock protecting this socket
[663]	2204	remote_queuelock_acquire( socket_lock_xp );
[657]	2205
[663]	2206	// get relevant socket infos
	2207	socket_type = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->type ));
	2208	socket_state = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->state ));
	2209	src_ip_addr = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->local_addr ));
	2210	dst_ip_addr = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->remote_addr ));
[657]	2211
[663]	2212	// compute UDP/TCP packet base in kernel buffer
	2213	k_trsp_base = k_buf + ETH_HEAD_LEN + IP_HEAD_LEN;
	2214
	2215	// set default values
	2216	do_send = false;
	2217	trsp_length = 0;
	2218	nbytes = 0;
	2219
	2220	if( cmd_valid ) // handle TX command
[657]	2221	{
	2222	// 2. get command arguments from socket
[663]	2223	cmd_type = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->tx_cmd ));
	2224	tx_buf = hal_remote_lpt( XPTR( socket_cxy , &socket_ptr->tx_buf ));
	2225	len = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->tx_len ));
	2226	todo = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->tx_todo ));
	2227	client_xp = hal_remote_l64( XPTR( socket_cxy , &socket_ptr->tx_client ));
[657]	2228
[663]	2229	#if DEBUG_DEV_NIC_TX
	2230	cycle = (uint32_t)hal_get_cycles();
	2231	if( cycle > DEBUG_DEV_NIC_TX )
	2232	printk("\n[%s] thread[%x,%x] cmd_valid for socket[%x,%d] : %s / %s / cycle %d\n",
	2233	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2234	socket_cmd_type_str(cmd_type), socket_state_str(socket_state), cycle );
	2235	#endif
[657]	2236
[663]	2237	//////////////////////////////////////////////////////////
[657]	2238	// 3. UDP : build UDP packet and update UDP socket state
	2239	if( socket_type == SOCK_DGRAM )
	2240	{
[663]	2241	trsp_protocol = PROTOCOL_UDP;
	2242
	2243	if( socket_state != UDP_STATE_ESTAB )
[657]	2244	{
[663]	2245	// reset tx_valid
	2246	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ) , false );
[657]	2247
[663]	2248	// unblock client thread / report error
	2249	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADSTATE );
[657]	2250	}
[663]	2251	else
[657]	2252	{
[663]	2253	if( cmd_type == CMD_TX_SEND )
[657]	2254	{
	2255	// compute payload length
	2256	nbytes = ( PAYLOAD_MAX_LEN < todo ) ? PAYLOAD_MAX_LEN : todo;
	2257
[663]	2258	// move payload from tx_buf to 2 Kbytes kernel buffer
	2259	memcpy( k_trsp_base + UDP_HEAD_LEN,
	2260	tx_buf + (len - todo),
	2261	nbytes );
[657]	2262
	2263	// build UDP header
[663]	2264	dev_nic_tx_build_udp_header( k_trsp_base,
[657]	2265	socket_xp,
	2266	nbytes );
	2267
	2268	// update "tx_todo" in socket descriptor
[663]	2269	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_todo), todo - nbytes );
[657]	2270
[663]	2271	// send UDP packet
	2272	trsp_length = UDP_HEAD_LEN + nbytes;
	2273	do_send = true;
	2274
	2275	#if( DEBUG_DEV_NIC_TX & 1)
	2276	cycle = (uint32_t)hal_get_cycles();
	2277	if( cycle > DEBUG_DEV_NIC_TX )
	2278	printk("\n[%s] thread[%x,%x] socket[%x,%d] UDP packet build / length %d / cycle %d\n",
	2279	__FUNCTION__, this->process->pid, this->trdid, trsp_length , cycle );
	2280	#endif
	2281	if( nbytes == todo ) // last byte sent
[657]	2282	{
[663]	2283	// reset tx_valid
	2284	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ) , false );
	2285
	2286	// report success to TX client
	2287	dev_nic_unblock_tx_client( socket_xp , CMD_STS_SUCCESS );
[657]	2288	}
	2289	}
[663]	2290	else // CONNECT, ACCEPT, or CLOSE commands are illegal for UDP
[657]	2291	{
[663]	2292	// reset tx_valid
	2293	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ) , false );
[657]	2294
[663]	2295	// report error
	2296	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADCMD );
[657]	2297	}
	2298	}
	2299	} // end UDP
	2300
[663]	2301	///////////////////////////////////////////////////////////
[657]	2302	// 3. TCP : build TCP segment and update TCP socket state
[663]	2303	else if( socket_type == SOCK_STREAM )
[657]	2304	{
[663]	2305	trsp_protocol = PROTOCOL_TCP;
	2306
	2307	// handle R2T request / initialize r2t_flags
	2308	if( r2t_valid )
[657]	2309	{
[663]	2310	// build extended pointers on r2t queue
	2311	socket_r2tq_xp = XPTR( socket_cxy , &socket_ptr->r2tq );
	2312
	2313	// get one request from R2T queue
[657]	2314	remote_buf_get_to_kernel( socket_r2tq_xp , &r2t_flags , 1 );
	2315	}
	2316	else
	2317	{
	2318	r2t_flags = 0;
	2319	}
	2320
[663]	2321	////////////////////////////////
	2322	if( cmd_type == CMD_TX_CONNECT ) // always executed by a TCP client
[657]	2323	{
[663]	2324	if( (socket_state == TCP_STATE_BOUND) \|\|
	2325	(socket_state == TCP_STATE_LISTEN) ) // send a SYN segment
[657]	2326	{
[663]	2327	// initialises socket tx_nxt, and rx_wnd
	2328	hal_remote_s32(XPTR(socket_cxy , &socket_ptr->tx_nxt), TCP_ISS_CLIENT );
	2329	hal_remote_s32(XPTR(socket_cxy , &socket_ptr->rx_wnd), TCP_MAX_WINDOW );
[657]	2330
[663]	2331	// build TCP SYN segment
	2332	dev_nic_tx_build_tcp_header( k_trsp_base,
[657]	2333	socket_xp,
[663]	2334	0, // length
	2335	TCP_FLAG_SYN );
	2336	// send segment
	2337	trsp_length = TCP_HEAD_LEN;
	2338	do_send = true;
[657]	2339
[663]	2340	#if DEBUG_DEV_NIC_TX
	2341	cycle = (uint32_t)hal_get_cycles();
	2342	if( cycle > DEBUG_DEV_NIC_TX )
	2343	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s / CONNECT / "
	2344	"TCP SYN build / cycle %d\n",
	2345	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2346	socket_state_str( socket_state ), cycle );
	2347	#endif
	2348	// update socket.state
	2349	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
	2350	TCP_STATE_SYN_SENT );
[657]	2351
[663]	2352	// update socket.tx_nxt
[657]	2353	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_nxt ),
[663]	2354	TCP_ISS_CLIENT + 1 );
[657]	2355
[663]	2356	// reset tx_valid but do not unblock client thread
	2357	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
	2358	}
	2359	else // report error for all other socket states
[657]	2360	{
[663]	2361	// reset tx_valid
	2362	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ) , false );
	2363
	2364	// report error
	2365	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADSTATE );
[657]	2366	}
	2367	}
[663]	2368	////////////////////////////////////
	2369	else if( cmd_type == CMD_TX_ACCEPT ) // always executed by a TCP server
[657]	2370	{
[663]	2371
	2372	if( socket_state == TCP_STATE_SYN_RCVD ) // send a SYN-ACK segment
[657]	2373	{
[663]	2374	// initialize socket tx_nxt, and rx_wnd
	2375	hal_remote_s32(XPTR(socket_cxy , &socket_ptr->tx_nxt), TCP_ISS_SERVER );
	2376	hal_remote_s32(XPTR(socket_cxy , &socket_ptr->rx_wnd), NIC_RX_BUF_SIZE);
	2377
	2378	// build TCP ACK-SYN segment
	2379	dev_nic_tx_build_tcp_header( k_trsp_base,
	2380	socket_xp,
	2381	0, // length
	2382	TCP_FLAG_SYN \| TCP_FLAG_ACK );
	2383	// send segment
	2384	trsp_length = TCP_HEAD_LEN;
	2385	do_send = true;
	2386
	2387	#if DEBUG_DEV_NIC_TX
	2388	cycle = (uint32_t)hal_get_cycles();
	2389	if( cycle > DEBUG_DEV_NIC_TX )
	2390	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s / ACCEPT / send SYN-ACK / cycle %d\n",
	2391	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2392	socket_state_str( socket_state ), cycle );
	2393	#endif
	2394	// update socket.state
[657]	2395	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ),
[663]	2396	TCP_STATE_SYN_RCVD );
[657]	2397
[663]	2398	// update socket.tx_nxt
	2399	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_nxt ),
	2400	TCP_ISS_SERVER + 1 );
	2401
	2402	// reset tx_valid but do not unblock client thread
	2403	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
[657]	2404	}
[663]	2405	else // report error in all other socket states
[657]	2406	{
[663]	2407	// reset tx_valid
	2408	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
[657]	2409
[663]	2410	// report error to TX client thread
	2411	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADSTATE );
[657]	2412	}
	2413	}
[663]	2414	///////////////////////////////////
	2415	else if( cmd_type == CMD_TX_CLOSE )
[657]	2416	{
[663]	2417	if( (socket_state == TCP_STATE_SYN_RCVD ) \|\|
	2418	(socket_state == TCP_STATE_ESTAB ) \|\|
	2419	(socket_state == TCP_STATE_CLOSE_WAIT) ) // send a FIN-ACK segment
[657]	2420	{
[663]	2421	// get "tx_nxt" from socket descriptor
	2422	tx_nxt = hal_remote_l32( XPTR(socket_cxy , &socket_ptr->tx_nxt ));
[657]	2423
[663]	2424	// compute next state
	2425	uint32_t state = (socket_state == TCP_STATE_CLOSE_WAIT) ?
	2426	TCP_STATE_LAST_ACK : TCP_STATE_FIN_WAIT1;
[657]	2427
[663]	2428	// update socket state
	2429	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->state ), state );
[657]	2430
	2431	// build TCP FIN segment
[663]	2432	dev_nic_tx_build_tcp_header( k_trsp_base,
[657]	2433	socket_xp,
[663]	2434	0, // length
	2435	TCP_FLAG_FIN \| TCP_FLAG_ACK );
[657]	2436
[663]	2437	// update "tx_nxt" in socket descriptor
	2438	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_nxt), tx_nxt + 1 );
	2439
	2440	// send segment
	2441	trsp_length = TCP_HEAD_LEN;
	2442	do_send = true;
	2443
	2444	#if DEBUG_DEV_NIC_TX
	2445	cycle = (uint32_t)hal_get_cycles();
	2446	if( cycle > DEBUG_DEV_NIC_TX )
	2447	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s / CLOSE / send FIN-ACK / cycle %d\n",
	2448	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2449	socket_state_str( socket_state ), cycle );
	2450	#endif
	2451	// reset tx_valid but do not unblock client thread
	2452	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
[657]	2453	}
[663]	2454	else // all other states => signal error
[657]	2455	{
	2456
[663]	2457	#if DEBUG_DEV_NIC_TX
	2458	cycle = (uint32_t)hal_get_cycles();
	2459	if( cycle > DEBUG_DEV_NIC_TX )
	2460	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s / CLOSE / error BADSTATE / cycle %d\n",
	2461	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2462	socket_state_str( socket_state ), cycle );
	2463	#endif
	2464	// reset tx_valid
	2465	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
	2466
	2467	// report error
	2468	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADSTATE );
[657]	2469	}
	2470	}
[663]	2471	/////////////////////////////////////
	2472	else if( cmd_type == CMD_TX_SEND )
[657]	2473	{
[663]	2474	if( (socket_state == TCP_STATE_ESTAB ) \|\|
	2475	(socket_state == TCP_STATE_CLOSE_WAIT) )
[657]	2476	{
[663]	2477	// get "tx_nxt" from socket descriptor
	2478	tx_nxt = hal_remote_l32( XPTR(socket_cxy , &socket_ptr->tx_nxt ));
	2479
	2480	// compute actual payload length
	2481	nbytes = ( PAYLOAD_MAX_LEN < todo ) ? PAYLOAD_MAX_LEN : todo;
	2482
	2483	// compute TCP segment base in kernel buffer
	2484	k_trsp_base = k_buf + ETH_HEAD_LEN + IP_HEAD_LEN;
	2485
	2486	// move payload to k_buf
	2487	memcpy( k_trsp_base + TCP_HEAD_LEN,
	2488	tx_buf + (len - todo),
	2489	nbytes );
	2490
	2491	// build TCP header
	2492	dev_nic_tx_build_tcp_header( k_trsp_base,
[657]	2493	socket_xp,
[663]	2494	nbytes, // payload
	2495	TCP_FLAG_ACK \| r2t_flags ); // flags
[657]	2496
[663]	2497	// update "tx_todo" in socket descriptor
	2498	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_todo), todo - nbytes );
	2499
	2500	// update "tx_nxt" in socket descriptor
	2501	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_nxt), tx_nxt + nbytes );
	2502
	2503	// send TCP segment
	2504	trsp_length = TCP_HEAD_LEN + nbytes;
	2505	do_send = true;
	2506
	2507	if( todo == nbytes ) // last byte sent
	2508	{
	2509	// reset tx_valid when last byte has been sent
	2510	hal_remote_s32( XPTR(socket_cxy , &socket_ptr->tx_valid), false );
	2511	}
	2512
	2513	#if DEBUG_DEV_NIC_TX
	2514	cycle = (uint32_t)hal_get_cycles();
	2515	if( cycle > DEBUG_DEV_NIC_TX )
	2516	printk("\n[%s] thread[%x,%x] socket[%x,%d] %s / SEND / "
	2517	"TCP DATA build / payload %d / cycle %d\n",
	2518	__FUNCTION__, this->process->pid, this->trdid, pid, fdid,
	2519	socket_state_str( socket_state ), nbytes, cycle );
	2520	#endif
[657]	2521	}
[663]	2522	else // all other socket states
[657]	2523	{
[663]	2524	// reset tx_valid
	2525	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
[657]	2526
[663]	2527	// report error to TX client thread
	2528	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADSTATE );
[657]	2529	}
	2530	}
[663]	2531	///////////////////////////////////
	2532	else // undefined TX command type
[657]	2533	{
[663]	2534	// reset tx_valid
	2535	hal_remote_s32( XPTR( socket_cxy , &socket_ptr->tx_valid ), false );
[657]	2536
[663]	2537	// report error to TX client thread
	2538	dev_nic_unblock_tx_client( socket_xp , CMD_STS_BADCMD );
[657]	2539	}
[663]	2540	} // end TCP
	2541	}
	2542	else // no valid TX command => handle R2T request only
[657]	2543	{
[663]	2544	// get one request from R2T queue
	2545	remote_buf_get_to_kernel( socket_r2tq_xp , &r2t_flags , 1 );
[657]	2546
[663]	2547	#if DEBUG_DEV_NIC_TX
	2548	cycle = (uint32_t)hal_get_cycles();
	2549	if( cycle > DEBUG_DEV_NIC_TX )
	2550	printk("\n[%s] thread[%x,%x] only r2t_valid for socket[%x,%d] / flags %x / cycle %d\n",
	2551	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, r2t_flags, cycle );
	2552	#endif
	2553
	2554	// build TCP header
	2555	dev_nic_tx_build_tcp_header( k_trsp_base,
	2556	socket_xp,
	2557	0, // payload length
	2558	r2t_flags ); // flags
	2559	// send TCP segment
	2560	trsp_protocol = PROTOCOL_TCP;
	2561	trsp_length = TCP_HEAD_LEN;
	2562	do_send = true;
[657]	2563	}
	2564
	2565	// 4. release the lock protecting the socket
[663]	2566	remote_queuelock_release( socket_lock_xp );
[657]	2567
	2568	// return if no packet to send
	2569	if( do_send == false ) return;
	2570
	2571	// 5. build IP header
	2572	dev_nic_tx_build_ip_header( k_buf + ETH_HEAD_LEN,
	2573	src_ip_addr,
	2574	dst_ip_addr,
[663]	2575	trsp_protocol,
	2576	trsp_length );
[657]	2577
[663]	2578	#if( DEBUG_DEV_NIC_TX & 1)
	2579	cycle = (uint32_t)hal_get_cycles();
	2580	if( cycle > DEBUG_DEV_NIC_TX )
	2581	printk("\n[%s] thread[%x,%x] IP header build / length %d / cycle %d\n",
	2582	__FUNCTION__, this->process->pid, this->trdid, IP_HEAD_LEN + trsp_length , cycle );
	2583	#endif
	2584
[657]	2585	// 6. build ETH header
	2586	dev_nic_tx_build_eth_header( k_buf,
[663]	2587	(uint8_t)DST_MAC_5,
	2588	(uint8_t)DST_MAC_4,
	2589	(uint8_t)DST_MAC_3,
	2590	(uint8_t)DST_MAC_2,
	2591	(uint8_t)DST_MAC_1,
	2592	(uint8_t)DST_MAC_0,
	2593	(uint8_t)SRC_MAC_5,
	2594	(uint8_t)SRC_MAC_4,
	2595	(uint8_t)SRC_MAC_3,
	2596	(uint8_t)SRC_MAC_2,
	2597	(uint8_t)SRC_MAC_1,
	2598	(uint8_t)SRC_MAC_0,
	2599	IP_HEAD_LEN + trsp_length );
[657]	2600
[663]	2601	#if( DEBUG_DEV_NIC_TX & 1)
	2602	cycle = (uint32_t)hal_get_cycles();
	2603	if( cycle > DEBUG_DEV_NIC_TX )
	2604	printk("\n[%s] thread[%x,%x] ETH header build / cycle %d\n",
	2605	__FUNCTION__, this->process->pid, this->trdid, cycle );
	2606	#endif
	2607
	2608	// 7. move packet to NIC_TX queue (blocking function)
[657]	2609	dev_nic_tx_move_packet( chdev,
	2610	k_buf,
	2611	ETH_HEAD_LEN + IP_HEAD_LEN + trsp_length );
	2612
[663]	2613	#if DEBUG_DEV_NIC_TX
	2614	cycle = (uint32_t)hal_get_cycles();
	2615	if( cycle > DEBUG_DEV_NIC_TX )
	2616	printk("\n[%s] thread[%x,%x] for socket[%x,%d] moved packet to NIC_TX / cycle %d\n",
	2617	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, cycle );
	2618	#endif
[657]	2619
[663]	2620	} // end dev_nic_tx_build_packet()
	2621
	2622
[657]	2623	/////////////////////////////////////////
	2624	void dev_nic_tx_server( chdev_t * chdev )
	2625	{
	2626	uint8_t k_buf[NIC_KERNEL_BUF_SIZE]; // buffer for one packet
	2627
[663]	2628	xptr_t queue_root_xp; // extended pointer on sockets list root
	2629	xptr_t queue_lock_xp; // extended pointer on lock protecting this list
	2630	xptr_t socket_xp; // extended pointer on on registered socket
[657]	2631	socket_t * socket_ptr;
	2632	cxy_t socket_cxy;
[663]	2633	xptr_t iter_xp; // iterator for loop on registered sockets
	2634	xlist_entry_t temp_root; // root of temporary list of sockets
	2635	xptr_t temp_root_xp; // extended pointer on temporary list of sockets
	2636	uint32_t temp_nr; // number of active registered sockets
	2637	bool_t cmd_valid; // TX command valid in socket descriptor
	2638	bool_t r2t_valid; // valid R2T request in socket descriptor
[657]	2639
	2640	thread_t * this = CURRENT_THREAD;
	2641
[663]	2642	#if DEBUG_DEV_NIC_TX
	2643	uint32_t cycle = (uint32_t)hal_get_cycles();
	2644	uint32_t pid;
	2645	uint32_t fdid;
	2646	if( cycle > DEBUG_DEV_NIC_TX )
	2647	printk("\n[%s] thread[%x,%x] starts / cycle %d\n",
	2648	__FUNCTION__, this->process->pid, this->trdid, cycle );
	2649	#endif
	2650
[657]	2651	// check chdev direction and type
	2652	assert( (chdev->func == DEV_FUNC_NIC) && (chdev->is_rx == false) ,
	2653	"illegal chdev type or direction" );
	2654
	2655	// check thread can yield
[663]	2656	thread_assert_can_yield( this , __FUNCTION__ );
[657]	2657
[663]	2658	// build extended pointer on temporary list
	2659	temp_root_xp = XPTR( local_cxy , &temp_root );
	2660
	2661	// build extended pointer on client sockets queue (lock & root)
	2662	queue_lock_xp = XPTR( local_cxy , &chdev->wait_lock );
	2663	queue_root_xp = XPTR( local_cxy , &chdev->wait_root );
[657]	2664
	2665	while( 1 ) // TX server infinite loop
	2666	{
[663]	2667	// initialize temporary list of registered sockets as empty
	2668	xlist_root_init( temp_root_xp );
	2669	temp_nr = 0;
	2670
[657]	2671	// take the lock protecting the client sockets queue
[663]	2672	remote_busylock_acquire( queue_lock_xp );
[657]	2673
[663]	2674	// build temporary list of all registered sockets
	2675	if( xlist_is_empty( queue_root_xp ) == false )
[657]	2676	{
[663]	2677	XLIST_FOREACH( queue_root_xp , iter_xp )
	2678	{
	2679	// get client socket cluster and local pointer
	2680	socket_xp = XLIST_ELEMENT( iter_xp , socket_t , tx_list );
	2681	socket_ptr = GET_PTR( socket_xp );
	2682	socket_cxy = GET_CXY( socket_xp );
	2683
	2684	// register socket in temporary list
	2685	xlist_add_last( temp_root_xp , XPTR( socket_cxy , &socket_ptr->tx_temp ));
	2686	temp_nr++;
	2687	}
	2688	}
	2689
	2690	// release the lock protecting the client sockets queue
	2691	remote_busylock_release( queue_lock_xp );
	2692
	2693	if( temp_nr > 0 )
	2694	{
	2695	// loop on temporary list
	2696	XLIST_FOREACH( temp_root_xp , iter_xp )
	2697	{
	2698	// get client socket cluster and local pointer
	2699	socket_xp = XLIST_ELEMENT( iter_xp , socket_t , tx_temp );
	2700	socket_ptr = GET_PTR( socket_xp );
	2701	socket_cxy = GET_CXY( socket_xp );
	2702
	2703	// get cmd_valid & t2t_valid from socket descriptor
	2704	cmd_valid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->tx_valid ));
	2705
	2706	// get r2t_valid from socket descriptor
	2707	r2t_valid = (bool_t)remote_buf_status( XPTR( socket_cxy , &socket_ptr->r2tq ));
	2708
	2709	// test if socket is active
	2710	if( cmd_valid \|\| r2t_valid ) // active socket
	2711	{
	2712
	2713	#if DEBUG_DEV_NIC_TX
	2714	cycle = (uint32_t)hal_get_cycles();
	2715	pid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->pid ));
	2716	fdid = hal_remote_l32( XPTR( socket_cxy , &socket_ptr->fdid ));
	2717	if( cycle > DEBUG_DEV_NIC_TX )
	2718	printk("\n[%s] thread[%x,%x] found socket[%x,%d] / cmd_valid %d / r2t_valid %d / cycle %d\n",
	2719	__FUNCTION__, this->process->pid, this->trdid, pid, fdid, cmd_valid, r2t_valid, cycle );
	2720	#endif
	2721	// build and send one packet/segment for this socket
	2722	dev_nic_tx_build_packet( cmd_valid,
	2723	r2t_valid,
	2724	socket_xp,
	2725	k_buf,
	2726	chdev );
	2727	#if DEBUG_DEV_NIC_TX
	2728	cycle = (uint32_t)hal_get_cycles();
	2729	if( cycle > DEBUG_DEV_NIC_TX )
	2730	dev_nic_packet_display( true, // is_tx
	2731	this->process->pid,
	2732	this->trdid,
	2733	cycle,
	2734	k_buf );
	2735	#endif
	2736	}
	2737	else // inactive socket
	2738	{
	2739	temp_nr--;
	2740	}
	2741	} // end loop on temporary list
	2742	}
	2743
	2744	// block & deschedule if no active socket found in current iteration
	2745	if( temp_nr == 0 )
	2746	{
[657]	2747
[663]	2748	#if DEBUG_DEV_NIC_TX
	2749	cycle = (uint32_t)hal_get_cycles();
	2750	if( cycle > DEBUG_DEV_NIC_TX )
	2751	printk("\n[%s] thread[%x,%x] no active socket => blocks on <CLIENT> / cycle %d\n",
	2752	__FUNCTION__, this->process->pid, this->trdid, cycle );
	2753	#endif
	2754
[657]	2755	// block and deschedule
	2756	thread_block( XPTR( local_cxy , this ) , THREAD_BLOCKED_CLIENT );
	2757	sched_yield( "waiting client" );
[663]	2758
	2759	#if DEBUG_DEV_NIC_TX
	2760	cycle = (uint32_t)hal_get_cycles();
	2761	if( cycle > DEBUG_DEV_NIC_TX )
	2762	printk("\n[%s] thread[%x,%x] resumes / cycle %d\n",
	2763	__FUNCTION__, this->process->pid, this->trdid, cycle );
	2764	#endif
[657]	2765	}
[663]	2766	} // end infinite while loop
	2767	} // end dev_nic_tx_server()
[657]	2768
	2769
[663]	2770	/////////////////////////////////////////////
	2771	void dev_nic_packet_display( bool_t is_tx,
	2772	pid_t thread_pid,
	2773	trdid_t thread_trdid,
	2774	uint32_t cycle,
	2775	uint8_t * buf )
	2776	{
	2777	// get ETH header fields
	2778	uint64_t eth_dst_mac = ((uint64_t)buf[5] << 40) \|
	2779	((uint64_t)buf[4] << 32) \|
	2780	((uint64_t)buf[3] << 24) \|
	2781	((uint64_t)buf[2] << 16) \|
	2782	((uint64_t)buf[1] << 8) \|
	2783	((uint64_t)buf[0] ) ;
[657]	2784
[663]	2785	uint64_t eth_src_mac = ((uint64_t)buf[11] << 40) \|
	2786	((uint64_t)buf[10] << 32) \|
	2787	((uint64_t)buf[9] << 24) \|
	2788	((uint64_t)buf[8] << 16) \|
	2789	((uint64_t)buf[7] << 8) \|
	2790	((uint64_t)buf[6] ) ;
[657]	2791
[663]	2792	uint16_t eth_length = ((uint16_t)buf[12] << 8) \|
	2793	((uint16_t)buf[13] ) ;
[657]	2794
[663]	2795	// get IP header fields
	2796	uint8_t ip_version = buf[14];
	2797	uint8_t ip_tos = buf[15];
	2798	uint16_t ip_length = ((uint16_t)buf[16] << 8) \|
	2799	((uint16_t)buf[17] ) ;
[657]	2800
[663]	2801	uint16_t ip_ident = ((uint16_t)buf[18] << 8) \|
	2802	((uint16_t)buf[19] ) ;
	2803	uint16_t ip_offset = ((uint16_t)buf[20] << 8) \|
	2804	((uint16_t)buf[21] ) ;
[657]	2805
[663]	2806	uint8_t ip_ttl = buf[22];
	2807	uint8_t ip_protocol = buf[23];
	2808	uint16_t ip_checksum = ((uint16_t)buf[24] << 8) \|
	2809	((uint16_t)buf[25] ) ;
[657]	2810
[663]	2811	uint32_t ip_src_addr = ((uint32_t)buf[26] << 24) \|
	2812	((uint32_t)buf[27] << 16) \|
	2813	((uint32_t)buf[28] << 8) \|
	2814	((uint32_t)buf[29] ) ;
	2815
	2816	uint32_t ip_dst_addr = ((uint32_t)buf[30] << 24) \|
	2817	((uint32_t)buf[31] << 16) \|
	2818	((uint32_t)buf[32] << 8) \|
	2819	((uint32_t)buf[33] ) ;
	2820
	2821	// get pointers on TXT0 chdev
	2822	xptr_t txt0_xp = chdev_dir.txt_tx[0];
	2823	cxy_t txt0_cxy = GET_CXY( txt0_xp );
	2824	chdev_t * txt0_ptr = GET_PTR( txt0_xp );
	2825
	2826	// get extended pointer on remote TXT0 chdev lock
	2827	xptr_t lock_xp = XPTR( txt0_cxy , &txt0_ptr->wait_lock );
	2828
	2829	// get TXT0 lock
	2830	remote_busylock_acquire( lock_xp );
	2831
	2832	if( is_tx )
	2833	{
	2834	nolock_printk("\n*** NIC_TX server thread[%x,%x] send packet / cycle %d\n",
	2835	thread_pid, thread_trdid, cycle );
	2836	}
	2837	else
	2838	{
	2839	nolock_printk("\n*** NIC_RX server thread[%x,%x] get packet / cycle %d\n",
	2840	thread_pid, thread_trdid, cycle );
	2841	}
	2842
	2843	nolock_printk("\n*** ETH header ***\n");
	2844	nolock_printk(" - dst_mac [6] = %l\n" , eth_dst_mac );
	2845	nolock_printk(" - src_mac [6] = %l\n" , eth_src_mac );
	2846	nolock_printk(" - length [2] = %d\n" , (uint32_t)eth_length );
	2847	nolock_printk("*** IP header ***\n");
	2848	nolock_printk(" - version [1] = %x\n" , (uint32_t)ip_version );
	2849	nolock_printk(" - tos [1] = %x\n" , (uint32_t)ip_tos );
	2850	nolock_printk(" - length [2] = %d\n" , (uint32_t)ip_length );
	2851	nolock_printk(" - ident [2] = %x\n" , (uint32_t)ip_ident );
	2852	nolock_printk(" - offset [2] = %x\n" , (uint32_t)ip_offset );
	2853	nolock_printk(" - ttl [1] = %x\n" , (uint32_t)ip_ttl );
	2854	nolock_printk(" - protocol [1] = %x\n" , (uint32_t)ip_protocol );
	2855	nolock_printk(" - checksum [2] = %x\n" , (uint32_t)ip_checksum );
	2856	nolock_printk(" - src_addr [4] = %x\n" , (uint32_t)ip_src_addr );
	2857	nolock_printk(" - dst_addr [4] = %x\n" , (uint32_t)ip_dst_addr );
	2858
	2859	// get UDP / TCP fields
	2860	if ( ip_protocol == PROTOCOL_UDP )
	2861	{
	2862	uint16_t udp_src_port = ((uint16_t)buf[34] << 8) \|
	2863	((uint16_t)buf[35] ) ;
	2864	uint16_t udp_dst_port = ((uint16_t)buf[36] << 8) \|
	2865	((uint16_t)buf[37] ) ;
	2866
	2867	nolock_printk("*** UDP header ***\n");
	2868	nolock_printk(" - src_port [2] = %d\n" , (uint32_t)udp_src_port );
	2869	nolock_printk(" - dst_port [2] = %d\n" , (uint32_t)udp_dst_port );
	2870	}
	2871	else if( ip_protocol == PROTOCOL_TCP )
	2872	{
	2873	uint16_t tcp_src_port = ((uint16_t)buf[34] << 8) \|
	2874	((uint16_t)buf[35] ) ;
	2875	uint16_t tcp_dst_port = ((uint16_t)buf[36] << 8) \|
	2876	((uint16_t)buf[37] ) ;
	2877
	2878	uint32_t tcp_seq_num = ((uint32_t)buf[38] << 24) \|
	2879	((uint32_t)buf[39] << 16) \|
	2880	((uint32_t)buf[40] << 8) \|
	2881	((uint32_t)buf[41] ) ;
	2882
	2883	uint32_t tcp_ack_num = ((uint32_t)buf[42] << 24) \|
	2884	((uint32_t)buf[43] << 16) \|
	2885	((uint32_t)buf[44] << 8) \|
	2886	((uint32_t)buf[45] ) ;
	2887
	2888	uint8_t tcp_hlen = buf[46];
	2889	uint8_t tcp_flags = buf[47];
	2890	uint16_t tcp_window = ((uint16_t)buf[48] << 8) \|
	2891	((uint16_t)buf[49] ) ;
	2892
	2893	uint16_t tcp_checksum = ((uint16_t)buf[50] << 8) \|
	2894	((uint16_t)buf[51] ) ;
	2895	uint16_t tcp_urgent = ((uint16_t)buf[52] << 8) \|
	2896	((uint16_t)buf[53] ) ;
	2897
	2898	nolock_printk("*** TCP header ***\n");
	2899	nolock_printk(" - src_port [2] = %x\n" , (uint32_t)tcp_src_port );
	2900	nolock_printk(" - dst_port [2] = %x\n" , (uint32_t)tcp_dst_port );
	2901	nolock_printk(" - seq_num [4] = %x\n" , (uint32_t)tcp_seq_num );
	2902	nolock_printk(" - ack_num [4] = %x\n" , (uint32_t)tcp_ack_num );
	2903	nolock_printk(" - hlen [1] = %d\n" , (uint32_t)tcp_hlen );
	2904	nolock_printk(" - flags [1] = %x\n" , (uint32_t)tcp_flags );
	2905	nolock_printk(" - window [2] = %x\n" , (uint32_t)tcp_window );
	2906	nolock_printk(" - checksum [2] = %x\n" , (uint32_t)tcp_checksum );
	2907	nolock_printk(" - urgent [2] = %x\n" , (uint32_t)tcp_urgent );
	2908	}
	2909	else
	2910	{
	2911	nolock_printk("!!!!! undefined transport protocol !!!!!\n");
	2912	}
	2913
	2914	// release TXT0 lock
	2915	remote_busylock_release( lock_xp );
	2916
	2917	} // end dev_nic_packet_display()
	2918

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