SVN Repository / Prohlížení

enc28j60_ip.c

   1  /*******************************************************************************
   2     enc28j60_ip.c: Sitova vrstva modelu TCP/IP
   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_arp.h"
  48  #include "enc28j60_ip.h"
  49  #include "enc28j60_icmp.h"
  50  #include "enc28j60_tcp.h"
  51  #include "enc28j60_udp.h"
  52  
  53  // pro prevod 4xchar na 1 long, pro IP adresy, v "net order"
  54  #define CHAR_TO_LONG(x0,x1,x2,x3) ( ((unsigned long)x0<<24)|((unsigned long)x1<<16)|((unsigned int)x2<<8)|x3)
  55  
  56  
  57  extern unsigned char broadcast_mac[MAC_LEN];
  58  
  59  unsigned long local_ip = 0;
  60  unsigned long ip_netmask = 0;
  61  unsigned long default_gateway = 0;
  62  unsigned long dns_server = 0;
  63  unsigned int ip_seq_num = 1;
  64  
  65  
  66  /**
  67  
  68   **/
  69  void ip_recv(void){
  70  
  71  	struct ip_h ip_header;
  72  
  73  	if(rx_read(&ip_header,IP_HEADER_LEN) != IP_HEADER_LEN)
  74  		return;
  75  
  76  	//kontrola verze IP a minimalni delky hlavicky
  77  	if((ip_header.ipv != IPv4) | (ip_header.header_len < 4))
  78  		return;
  79  
  80  	//kontrola fragmentacnich flagu
  81  	if(ip_header.fragment & NTOHS(IP_FRAG_OFFSET|IP_FRAG_MORE))		//fragmentovany paket,zahodit
  82  		return;
  83  
  84  	//kontrola IP adresy
  85  	if(NTOHL(ip_header.dest_ip) != local_ip && (NTOHL(ip_header.dest_ip)|ip_netmask) != IP_BROADCAST )
  86  		return;
  87  
  88  
  89  	//pokud je hlavicka delsi nez obvyklych 20B (volitelne polozky), zahodime je
  90  	if( ( ((unsigned char)ip_header.header_len) <<2) > IP_HEADER_LEN){		//header_len *4
  91  		rx_skip ( ( ((unsigned char)ip_header.header_len) <<2) - IP_HEADER_LEN);
  92  	}
  93  
  94  	//odstraneni paddingu
  95  	if(NTOHS(ip_header.length) < MIN_IP_LEN){
  96  		rx_cut_padding(MIN_IP_LEN - NTOHS(ip_header.length));
  97  
  98  	}
  99  
 100  
 101  	switch(ip_header.protocol){
 102  		case IP_PROTO_ICMP:
 103  			icmp_recv(&ip_header);
 104  			break;
 105  		case IP_PROTO_TCP:
 106  			tcp_recv(&ip_header);
 107  			break;
 108  		case IP_PROTO_UDP:
 109  			udp_recv(&ip_header);
 110  			break;
 111  	}
 112  
 113  return;
 114  }
 115  
 116  /**
 117  
 118   **/
 119  char ip_send(unsigned long dest_addr,unsigned char protocol){
 120  
 121  	struct ip_h ip_header;
 122  
 123  	tx_seek(IP_HEADER);								//jiz zde kvuli volani tx_data_len() nize
 124  
 125  	ip_header.ipv = IPv4;
 126  	ip_header.header_len = IP_HEADER_LEN >> 2;		// deleno ctyrmi, udava se totiz v DWORD
 127  	ip_header.tos = 0;
 128  	ip_header.length = HTONS(tx_data_len());
 129  	ip_header.identification = HTONS(ip_seq_num);
 130  	ip_seq_num++;
 131  
 132  	ip_header.fragment = 0;
 133  	ip_header.ttl = DEFAULT_TTL;
 134  	ip_header.protocol = protocol;
 135  	ip_header.checksum = 0;
 136  	ip_header.src_ip = HTONL(local_ip);
 137  	ip_header.dest_ip = HTONL(dest_addr);
 138  
 139  		//pri pocitani checksumu z hlavicky, ktera je big endian, jiz nemusime checksum prevadet pomoci HTONS
 140  	ip_header.checksum = count_checksum(&ip_header,IP_HEADER_LEN);
 141  
 142  
 143  	tx_write(&ip_header,IP_HEADER_LEN);
 144  
 145  
 146  	//*****************************
 147  	//cil nelezi ve stejne podsiti
 148  	//*****************************
 149  	if(default_gateway != 0){
 150  		if((local_ip & ip_netmask) != (dest_addr & ip_netmask)){
 151  			dest_addr = default_gateway;
 152  		}
 153  	}
 154  
 155  	//********
 156  	//ARP
 157  	//*********
 158  	char * dest_mac;
 159  
 160  	if(dest_addr == IP_BROADCAST){			//IP broadcast se posila na broadcastovou mac
 161  		dest_mac = broadcast_mac;
 162  	}
 163  	else{
 164  		dest_mac = arp_table_find(dest_addr);
 165  	}
 166  
 167  	if(dest_mac == NULL){						//neexistuje arp zaznam
 168  
 169  		//ulozeni ukazatelu do bufferu behem vyrizovani ARP dotazu
 170  		unsigned char last_act = tx_act();
 171  
 172  		tx_save(last_act);
 173  
 174  		//odeslani ARP dotazu
 175  		arp_send(dest_addr);
 176  
 177  		unsigned int timer = ARP_TIMEOUT;		//timeout
 178  
 179  		//cekani na ARP odpoved
 180  		while((arp_table_find(dest_addr) == NULL) & (timer-- > 0) ){ //az dojde odpoved, zapise se do arp tabulky
 181  			ENC28J60_idle();						//obsluha prichozich paketu
 182  		};
 183  
 184  		dest_mac = arp_table_find(dest_addr);
 185  
 186  		if( dest_mac == NULL){						//odpoved na arp nedosla do timeoutu
 187  			if(last_act == TX1)
 188  				tx_unlock(TX1);							//vypnuti ochrany proti prepsani tx bufferu
 189  			else if(last_act == TX2)
 190  				tx_unlock(TX2);
 191  
 192  
 193  			return -2;
 194  		}
 195  		else{
 196  			tx_load(last_act);
 197  			return eth_send(dest_mac,ETH_PROTO_IP);		//odeslani paketu na ziskanou mac adresu
 198  		}
 199  
 200  	}
 201  
 202  return eth_send(dest_mac,ETH_PROTO_IP);
 203  }
 204  
 205  
 206  /**
 207  
 208   **/
 209  unsigned int count_checksum(void* pointer,int count){	//vypocet CRC souctu,podle RFC 1071
 210  
 211    unsigned long sum = 0;
 212    unsigned int* ptr = (unsigned int*)pointer;
 213  
 214          while( count > 1 ){
 215  			sum += *(ptr++);
 216  			count -=2;
 217  		}
 218  
 219  		if(count == 1)
 220  			sum += *((unsigned char*) ptr);
 221  
 222  		while(sum >> 16){
 223  	        sum = (sum & 0xFFFF) + (sum >> 16);
 224  		}
 225  
 226  return (unsigned int) ~sum;
 227  }
 228  
 229  
 230  
 231  /**
 232  
 233   **/
 234  inline void set_ip(unsigned char a0,unsigned char a1,unsigned char a2, unsigned char a3){
 235  	local_ip = CHAR_TO_LONG(a0,a1,a2,a3);
 236  }
 237  
 238  /**
 239  
 240   **/
 241  inline void set_ip_l(unsigned long ip){
 242  	local_ip = ip;
 243  }
 244  /**
 245  
 246   **/
 247  inline unsigned long get_ip(){
 248  	return local_ip;
 249  }
 250  
 251  /**
 252  
 253   **/
 254  inline void set_netmask(unsigned char m0,unsigned char m1,unsigned char m2, unsigned char m3){
 255  	ip_netmask = CHAR_TO_LONG(m0,m1,m2,m3);
 256  }
 257  /**
 258  
 259   **/
 260  inline void set_netmask_l(unsigned long netmask){
 261  	ip_netmask = netmask;
 262  }
 263  /**
 264  
 265   **/
 266  inline unsigned long get_netmask(){
 267  	return ip_netmask;
 268  }
 269  
 270  /**
 271  
 272   **/
 273  inline void set_gateway(unsigned char g0,unsigned char g1,unsigned char g2, unsigned char g3){
 274  	default_gateway = CHAR_TO_LONG(g0,g1,g2,g3);
 275  }
 276  /**
 277  
 278   **/
 279  inline void set_gateway_l(unsigned long gateway){
 280  	default_gateway = gateway;
 281  }
 282  /**
 283  
 284   **/
 285  inline unsigned long get_gateway(){
 286  	return default_gateway;
 287  }
 288  
 289  /**
 290  
 291   **/
 292  inline void set_dns_server(unsigned char d0,unsigned char d1,unsigned char d2, unsigned char d3){
 293  	dns_server = CHAR_TO_LONG(d0,d1,d2,d3);
 294  }
 295  /**
 296  
 297   **/
 298  inline void set_dns_server_l(unsigned long dns){
 299  	dns_server = dns;
 300  }
 301  /**
 302  
 303   **/
 304  inline unsigned long get_dns_server(){
 305  	return dns_server;
 306  }
 307  
 308