ip_addr.c

RTL-lwIP is the porting of the lwIP TCP/IP stack to RTLinux-GPL.The focus of the RTL-lwIP stack is

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <[e-mail]>
 *
 */

#include "lwip/ip_addr.h"
#include "lwip/inet.h"
#include "lwip/netif.h"
#include <string.h>

#define htons HTONS
#define htonl HTONL
#define ntohl NTOHL

/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
const struct ip_addr ip_addr_any = { 0x00000000UL };
const struct ip_addr ip_addr_broadcast = { 0xffffffffUL };


/*-----------------------------------------------------------------------------------*/
int get_int_from_char(char c){

  /* 0-9 */
  if((c >= 48) && (c <= 57)) return (c-48);
  return -1;
}


/*-----------------------------------------------------------------------------------*/
void string2ip_addr(struct ip_addr *ip, char *name, int size){
  int i, index=0, sum[4]={0,0,0,0}, ciphers[3]={0,0,0},cont=0;

  if(name != NULL){
    for(i=0; i<3; i++){
      do{
        ciphers[cont]=get_int_from_char(name[index]);
        index++;
        cont++;
      }while(name[index] != 0x2e); //0x2e is the hex ascii code for '.'
      if(cont==3)
        sum[i] = ciphers[0]*100 + ciphers[1]*10 + ciphers[2];
      else if(cont==2)
        sum[i] = ciphers[0]*10 + ciphers[1];
      else
        sum[i] = ciphers[0];
      index++;
      ciphers[0] = 0; ciphers[1]= 0; ciphers[2] = 0; cont = 0;
    }
    while(name[index]!='\0'){
      ciphers[cont]= get_int_from_char(name[index]);
      index++;
      cont++;
    }
    if(cont==3)
      sum[3] = ciphers[0]*100 + ciphers[1]*10 + ciphers[2];
    else if(cont==2)
      sum[3] = ciphers[0]*10 + ciphers[1];
    else
      sum[3] = ciphers[0];

    IP4_ADDR(ip, sum[0],sum[1],sum[2],sum[3]);
  }
}

/* Determine if an address is a broadcast address on a network interface 
 * 
 * @param addr address to be checked
 * @param netif the network interface against which the address is checked
 * @return returns non-zero if the address is a broadcast address
 *
 */

u8_t ip_addr_isbroadcast(struct ip_addr *addr, struct netif *netif)
{
  /* all ones (broadcast) or all zeroes (old skool broadcast) */
  if ((addr->addr == ip_addr_broadcast.addr) ||
      (addr->addr == ip_addr_any.addr))
    return 1;
  /* no broadcast support on this network interface? */
  else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0)
    /* the given address cannot be a broadcast address
     * nor can we check against any broadcast addresses */
    return 0;
  /* address matches network interface address exactly? => no broadcast */
  else if (addr->addr == netif->ip_addr.addr)
    return 0;
  /* host identifier bits are all ones? => network broadcast address */
  else if ((addr->addr & ~netif->netmask.addr) ==
           (ip_addr_broadcast.addr & ~netif->netmask.addr))
    return 1;
  else
    return 0;
}