SVN Repository / Prohlížení

enc28j60_tcp.c

   1  /*******************************************************************************
   2  
   3     Copyright (C) 2010 Brno University of Technology,
   4                        Faculty of Information Technology
   5     Author(s): Martin Musil <xmusil34 AT fit.vutbr.cz>
   6  
   7     LICENSE TERMS
   8  
   9     Redistribution and use in source and binary forms, with or without
  10     modification, are permitted provided that the following conditions
  11     are met:
  12     1. Redistributions of source code must retain the above copyright
  13        notice, this list of conditions and the following disclaimer.
  14     2. Redistributions in binary form must reproduce the above copyright
  15        notice, this list of conditions and the following disclaimer in
  16        the documentation and/or other materials provided with the
  17        distribution.
  18     3. All advertising materials mentioning features or use of this software
  19        or firmware must display the following acknowledgement:
  20  
  21          This product includes software developed by the University of
  22          Technology, Faculty of Information Technology, Brno and its
  23          contributors.
  24  
  25     4. Neither the name of the Company nor the names of its contributors
  26        may be used to endorse or promote products derived from this
  27        software without specific prior written permission.
  28  
  29     This software or firmware is provided ``as is'', and any express or implied
  30     warranties, including, but not limited to, the implied warranties of
  31     merchantability and fitness for a particular purpose are disclaimed.
  32     In no event shall the company or contributors be liable for any
  33     direct, indirect, incidental, special, exemplary, or consequential
  34     damages (including, but not limited to, procurement of substitute
  35     goods or services; loss of use, data, or profits; or business
  36     interruption) however caused and on any theory of liability, whether
  37     in contract, strict liability, or tort (including negligence or
  38     otherwise) arising in any way out of the use of this software, even
  39     if advised of the possibility of such damage.
  40  
  41     $Id$
  42  
  43  *******************************************************************************/
  44  
  45  #include "enc28j60_spi.h"
  46  #include "enc28j60_eth.h"
  47  #include "enc28j60_ip.h"
  48  #include "enc28j60_tcp.h"
  49  
  50  
  51  unsigned long dest_seq_num = 0;
  52  unsigned long local_seq_num = 0;
  53  unsigned long expected_ack_num = 0;
  54  
  55  struct ip_h* ip_header_ptr;
  56  
  57  extern unsigned long local_ip;
  58  extern unsigned int tcp_fsm_timer;
  59  
  60  struct tcp_socket socket;
  61  
  62  
  63  /**
  64  
  65   **/
  66  void tcp_recv(struct ip_h* ip_header){
  67  
  68  	struct tcp_h tcp_header;
  69  
  70  	if(rx_read(&tcp_header, TCP_HEADER_LEN) != TCP_HEADER_LEN)
  71  		return;
  72  
  73  	//port filtr
  74  	if( HTONS(tcp_header.dest_port) != socket.src_port)
  75  		return;
  76  
  77  	//IP filtr
  78  	if(socket.state != FSM_LISTEN){
  79  
  80  		if(socket.dest_port != NTOHS(tcp_header.src_port))
  81  			return;
  82  
  83  		if(socket.dest_ip != NTOHL(ip_header->src_ip))
  84  			return;
  85  	}
  86  
  87  	//pokud je hlavicka delsi nez obvyklych 20B (volitelne polozky), zahodime je
  88  	if( ( ((unsigned char)tcp_header.data_offset) <<2) > TCP_HEADER_LEN){		//header_len *4
  89  		rx_skip ( ( ((unsigned char)tcp_header.data_offset) <<2) - TCP_HEADER_LEN);
  90  	}
  91  
  92  	ip_header_ptr = ip_header;
  93  
  94  	//volani konecneho automatu
  95  	tcp_fsm(&tcp_header);
  96  
  97  return;
  98  }
  99  
 100  
 101  
 102  /**
 103  
 104   **/
 105  char tcp_send(){
 106  
 107  	if(tcp_connected()){
 108  		tx_seek(TCP_HEADER);
 109  		tx_save(TX3);
 110  		expected_ack_num = local_seq_num + tx_data_len() - TCP_HEADER_LEN;
 111  
 112  		if(tcp_fsm(NULL) == -1){
 113  			return -1;
 114  		}
 115  		else{
 116  			return 0;
 117  		}
 118  	}
 119  return -1;
 120  }
 121  
 122  
 123  /**
 124  
 125   **/
 126  char tcp_out(unsigned long seq, unsigned long ack, unsigned char flags){
 127  /*
 128  	if(!link_up())			//kabel odpojen,nebudeme odesilat
 129  		return -1;
 130  */
 131  	struct tcp_h tcp_header;
 132  
 133  	tcp_header.src_port = HTONS(socket.src_port);
 134  	tcp_header.dest_port = HTONS(socket.dest_port);
 135  	tcp_header.seq_num = HTONL(seq);
 136  
 137  	if((flags & TCP_ACK) != 0)
 138  		tcp_header.ack_num = HTONL(ack);
 139  	else
 140  		tcp_header.ack_num = 0;
 141  
 142  	tcp_header.reserved = 0;
 143  	tcp_header.data_offset = TCP_HEADER_LEN >> 2;
 144  	tcp_header.flags = flags;
 145  	tcp_header.window_size = HTONS(WINDOW_SIZE);
 146  	tcp_header.checksum = 0;
 147  	tcp_header.urgent_ptr = 0;
 148  
 149  	tx_seek(TCP_HEADER);
 150  	tx_write(&tcp_header, TCP_HEADER_LEN);
 151  
 152  	tx_seek(TCP_HEADER);
 153  	tcp_header.checksum = HTONS(tcp_checksum(socket.dest_ip, tx_data_len()));
 154  
 155  	tx_write(&tcp_header, TCP_HEADER_LEN);
 156  
 157  
 158  
 159  return ip_send(socket.dest_ip,IP_PROTO_TCP);
 160  }
 161  
 162  
 163  /**
 164  
 165   **/
 166  unsigned int tcp_checksum(unsigned long dest_ip,unsigned int length){
 167  
 168  	unsigned long sum = 0;
 169  	unsigned int* ptr;
 170  
 171  	ptr = (unsigned int*)&local_ip;
 172  	sum += *ptr;
 173  	ptr++;
 174  	sum += *ptr;
 175  
 176  	ptr = (unsigned int*)&dest_ip;
 177  	sum += *ptr;
 178  	ptr++;
 179  	sum += *ptr;
 180  
 181  	sum += IP_PROTO_TCP;
 182  	sum += length;
 183  
 184  	sum += (unsigned int) ~tx_checksum();
 185  
 186  	while(sum >>16)
 187  		sum = (sum & 0xFFFF) + (sum >> 16);
 188  
 189  return (unsigned int) ~sum;
 190  }
 191  
 192  /**
 193  
 194   **/
 195  char tcp_send_header(unsigned char flags){
 196  
 197  	if( tx_init(TCP_PROTO_HEADER_ONLY) < 0)
 198  		return -1;
 199  	tx_close();
 200  
 201  return tcp_out(local_seq_num,dest_seq_num, flags);
 202  }
 203  
 204  /**
 205  
 206   **/
 207  void tcp_fsm_reset(){
 208  
 209  	tx_unlock(TX3);
 210  
 211  	if(socket.type == TCP_SERVER)
 212  		socket.state = FSM_LISTEN;
 213  	else
 214  		socket.state = FSM_IDLE;
 215  }
 216  
 217  /**
 218  
 219  
 220   **/
 221  unsigned char create_tcp_socket(unsigned int src_port, void* handler){
 222  
 223  	if(src_port != 0){
 224  		socket.src_port = src_port;
 225  		socket.app_handler = handler;
 226  		socket.state = FSM_IDLE;
 227  		return src_port;
 228  	}
 229  	else
 230  		return 0;
 231  }
 232  
 233  /**
 234  
 235  
 236  
 237   **/
 238  char delete_tcp_socket(){
 239  
 240  	if(tcp_is_idle()){
 241  		socket.src_port = 0;
 242  		socket.app_handler = NULL;
 243  		socket.state = FSM_IDLE;
 244  		return 0;
 245  	}
 246  	else
 247  		return -1;
 248  }
 249  
 250  
 251  /**
 252  
 253   **/
 254  void change_tcp_handler(void* new_handler){
 255  
 256  	socket.app_handler = new_handler;
 257  
 258  return;
 259  }
 260  
 261  /**
 262  
 263   **/
 264  char tcp_connect(unsigned long ip, unsigned int port){
 265  
 266  	if(socket.state == FSM_IDLE){
 267  	socket.dest_ip = ip;
 268  	socket.dest_port = port;
 269  	socket.state = FSM_NOT_CONNECTED;
 270  	socket.type = TCP_CLIENT;
 271  	tcp_fsm(NULL);
 272  	return 0;
 273  	}
 274  	else return -1;
 275  }
 276  
 277  /**
 278  
 279   **/
 280  char tcp_bind(){
 281  
 282  	if((socket.state == FSM_IDLE) | ( socket.state == FSM_LISTEN)){
 283  		socket.state = FSM_LISTEN;
 284  		socket.type = TCP_SERVER;
 285  		return 1;
 286  	}
 287  
 288  return 0;
 289  }
 290  
 291  /**
 292  
 293   **/
 294  char tcp_unbind(){
 295  	if(( socket.state == FSM_LISTEN)){
 296  		socket.dest_port = 0;
 297  		socket.state = FSM_IDLE;
 298  		socket.type = TCP_SERVER;
 299  		return 1;
 300  	}
 301  return 0;
 302  }
 303  
 304  /**
 305  
 306   **/
 307  inline void tcp_disconnect(){
 308  	if(socket.state == FSM_ESTABILISHED){
 309  		tcp_fsm_timer = FIN_WAIT1_TIMEOUT;
 310  		socket.state = FSM_HALF_OPEN;
 311  		expected_ack_num++;				//+1 za FIN
 312  		tcp_fsm(NULL);
 313  	}
 314  }
 315  
 316  /**
 317  
 318   **/
 319  char tcp_connected(){
 320  
 321  	if(socket.state == FSM_ESTABILISHED)
 322  		return 1;
 323  
 324  else return 0;
 325  }
 326  
 327  /**
 328  
 329   **/
 330  char tcp_is_idle(){
 331  
 332  	if((socket.state == FSM_IDLE) | ( socket.state == FSM_LISTEN)){
 333  		return 1;
 334  	}
 335  
 336  return 0;
 337  
 338  }
 339  /**
 340  
 341  
 342   **/
 343  inline void tcp_timer(){
 344  
 345  tcp_fsm(NULL);
 346  }
 347