eth.c

实用的程序代码

/*
 * Ethernet functions
 */

#include <string.h>
#include <net/xilsock.h>

struct xilnet_hw_addr_table xilnet_hw_tbl[HW_ADDR_TBL_ENTRIES];
unsigned char ishwaddrinit = 0;

/* 
 * initialize xilnet hardware address
 */
void xilnet_eth_init_hw_addr(unsigned char* addr) {
   int k = 0;
   int j;
   int sum = 0;
   int val = 0;
   
   for (j = 0; j < 5; j++) {
   
      // parse input for colon separated hw address 
      while(addr[k] != ':') {
         if (addr[k] >= 'a' && addr[k] <= 'f') 
            val = addr[k] - 'a' + 10;
         else if (addr[k] >= 'A' && addr[k] <= 'F')
            val = addr[k] - 'A' + 10;
         else
            val = addr[k] - '0';
         sum = sum * 16 + val;
         k++;
      }
    
      k++; // move over the colon
      mb_hw_addr[j] = (unsigned char) sum;
      sum = 0;    
   }
   
   // read last byte of hw address
   while (addr[k] != '\0') {
      if (addr[k] >= 'a' && addr[k] <= 'f') 
         val = addr[k] - 'a' + 10;
      else if (addr[k] >= 'A' && addr[k] <= 'F')
         val = addr[k] - 'A' + 10;
      else
         val = addr[k] - '0';
      sum = sum * 16 + val;
      k++;
   }  
   mb_hw_addr[5] = (unsigned char) sum;
}


/*
 * Receive frame 
 */
int xilnet_eth_recv_frame(unsigned char *buf, int len) {

   struct xilnet_eth_hdr *eth;
  
   //device specific routine for getting a frame
#ifdef _CONFIG_EMAC_
   int size = XEmac_RecvFrame(MYMAC_BASEADDR, buf);
#else 
#ifdef _CONFIG_EMACLITE_
   int size = XEmacLite_RecvFrame(MYMAC_BASEADDR, buf);
#endif
#endif

   // Strip off the FCS(or CRC) from the received frame
   buf[size-1] = 0;
   buf[size-2] = 0;
   buf[size-3] = 0;
   buf[size-4] = 0;

   size -= 4;

   eth = (struct xilnet_eth_hdr*) buf;  
   
   switch (eth->type) {
   case ETH_PROTO_IP:
      return (xilnet_ip(buf, size));
   case ETH_PROTO_ARP:
      return (xilnet_arp(buf, size));
   default:
      break;
   }
   return -1;
}


/*
 * Send frame to peer ip addr, peer hw addr
 */
  

int xilnet_eth_send_frame(unsigned char *pkt, int len, unsigned char *dip_addr, void *dhw_addr, unsigned short type) {
   
   int i;
   int hw_tbl_index = 0;

   for (i = 0; i < ETH_ADDR_LEN; i++) {
      ((struct xilnet_eth_hdr*)pkt)->src_addr[i] = mb_hw_addr[i];
   }	       
   
   if (dhw_addr) 
      memcpy(((struct xilnet_eth_hdr*)pkt)->dest_addr, dhw_addr, ETH_ADDR_LEN);
   else {
      // find the hw tbl entry index corr to dip_addr
      hw_tbl_index = xilnet_eth_get_hw_addr(dip_addr);
      
      for (i = 0; i < ETH_ADDR_LEN; i++) {
         ((struct xilnet_eth_hdr*)pkt)->dest_addr[i] = xilnet_hw_tbl[hw_tbl_index].hw_addr[i];
      }
   }
   ((struct xilnet_eth_hdr*)pkt)->type = type;
   
   // pad the ethernet frame if < 60 bytes
   if (len < 60) { 
      for(i = len; i < ETH_MIN_FRAME_LEN; i++) {
         pkt[i] = 0;
      }
      len = ETH_MIN_FRAME_LEN;
   }
   
   // Write to MAC
#ifdef _CONFIG_EMAC_
   XEmac_SendFrame(MYMAC_BASEADDR, pkt, len);
#else 
#ifdef _CONFIG_EMACLITE_
   XEmacLite_SendFrame(MYMAC_BASEADDR, pkt, len);
#endif
#endif
   return len;
}


/*
 * Update Hardware Address Table
 */

void xilnet_eth_update_hw_tbl(unsigned char *buf, int proto) {

   unsigned char ip[IP_VERSION];
   unsigned char hw[ETH_ADDR_LEN];
   int i, j;
   struct xilnet_eth_hdr *eth = (struct xilnet_eth_hdr*) buf;

   // get hw addr
   for (i = 0; i < ETH_ADDR_LEN; i++) {
      hw[i] = ((struct xilnet_eth_hdr*)buf)->src_addr[i];
   }	 

   // get ip addr
   switch (proto) {
   case ETH_PROTO_ARP:
      for (i = 0; i < IP_VERSION; i++) {
         ip[i] = (buf+ETH_HDR_LEN)[ARP_SIP_OFFSET+i];
      }
      break;
   case ETH_PROTO_IP:
      for (i = 0; i < IP_VERSION; i++) {
         ip[i] = (buf+ETH_HDR_LEN)[IP_SADDR_BASE+i];
      }
      break;
   }

   // update the hw addr table

   for (i = 0; i < HW_ADDR_TBL_ENTRIES; i++) {
      if (xilnet_hw_tbl[i].flag) {
         if ( (hw[0] == xilnet_hw_tbl[i].hw_addr[0]) && (hw[1] == xilnet_hw_tbl[i].hw_addr[1]) &&
              (hw[2] == xilnet_hw_tbl[i].hw_addr[2]) && (hw[3] == xilnet_hw_tbl[i].hw_addr[3]) &&
              (hw[4] == xilnet_hw_tbl[i].hw_addr[4]) && (hw[5] == xilnet_hw_tbl[i].hw_addr[5])
              ) {
            for (j = 0; j < IP_VERSION; j++)
               xilnet_hw_tbl[i].ip_addr[j] = ip[j];;
            xilnet_hw_tbl[i].flag = HW_ADDR_ENTRY_IS_TRUE;
            return;
         }
      }
   }
   xilnet_add_hw_tbl_entry(ip, hw);
}


/*
 * Add an entry into Hw Addr table
 */

void xilnet_add_hw_tbl_entry(unsigned char *ip, unsigned char *hw) {

   int i, j;

   for (i = 0; i < HW_ADDR_TBL_ENTRIES; i++) {
      if (!xilnet_hw_tbl[i].flag) {
         for (j = 0; j < ETH_ADDR_LEN; j++) {
            xilnet_hw_tbl[i].hw_addr[j] = hw[j];
         }
         for (j = 0; j < IP_VERSION; j++)  {
            xilnet_hw_tbl[i].ip_addr[j] = ip[j];
         }
         xilnet_hw_tbl[i].flag = HW_ADDR_ENTRY_IS_TRUE;
         return;
      }
   }
   
   print("Add entry in Hw tbl Error \n");
   exit(1);
   
}


/*
 * Get index into hw tbl for ip_addr
 */

int xilnet_eth_get_hw_addr(unsigned char *ip) {

   int i;

   for (i = 0; i < HW_ADDR_TBL_ENTRIES; i++) {
      if (xilnet_hw_tbl[i].flag) 
         if ( (ip[0] == xilnet_hw_tbl[i].ip_addr[0]) && (ip[1] == xilnet_hw_tbl[i].ip_addr[1]) &&
              (ip[2] == xilnet_hw_tbl[i].ip_addr[2]) && (ip[3] == xilnet_hw_tbl[i].ip_addr[3]) ) {
	     return i;
	 }
   }
   print("Hw Addr Not found for IP \n");
   return -1;
   
}


/*	
 * Init the hw addr table
 */

void xilnet_eth_init_hw_addr_tbl() {

  int i;

  for (i = 0; i < HW_ADDR_TBL_ENTRIES; i++) {
    xilnet_hw_tbl[i].flag = HW_ADDR_ENTRY_IS_FALSE;
   }
  ishwaddrinit = 1;
}