utils.c

无线网络路有协议aodv的 linux的实现

/***************************************************************************
                          utils.c  -  description
                             -------------------
    begin                : Wed Jul 30 2003
    copyright            : (C) 2003 by Luke Klein-Berndt
    email                : [e-mail]
 ***************************************************************************/

 #include "utils.h"

u_int64_t getcurrtime()
{
    struct timeval tv;
    u_int64_t result;

    do_gettimeofday(&tv);

    //This is a fix for an error that occurs on ARM Linux Kernels because they do 64bits differently
    //Thanks to S. Peter Li for coming up with this fix!

    result = (u_int64_t) tv.tv_usec;
    do_div(result, 1000);
    return ((u_int64_t) tv.tv_sec) * 1000 + result;
}


char *inet_ntoa(u_int32_t ina)
{
    static char buf[4 * sizeof "123"];
    unsigned char *ucp = (unsigned char *) &ina;
    sprintf(buf, "%d.%d.%d.%d", ucp[0] & 0xff, ucp[1] & 0xff, ucp[2] & 0xff, ucp[3] & 0xff);
    return buf;
}

int inet_aton(const char *cp, u_int32_t * addr)
{
    unsigned int val;
    int base, n;
    char c;
    u_int parts[4];
    u_int *pp = parts;

    for (;;)
    {

        //Collect number up to ``.''. Values are specified as for C:
        // 0x=hex, 0=octal, other=decimal.

        val = 0;
        base = 10;
        if (*cp == '0')
        {
            if (*++cp == 'x' || *cp == 'X')
                base = 16, cp++;
            else
                base = 8;
        }
        while ((c = *cp) != '\0')
        {
            if (isascii(c) && isdigit(c))
            {
                val = (val * base) + (c - '0');
                cp++;
                continue;

            }
            if (base == 16 && isascii(c) && isxdigit(c))
            {
                val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
                cp++;
                continue;
            }
            break;
        }
        if (*cp == '.')
        {
            // Internet format: a.b.c.d a.b.c       (with c treated as
            // 16-bits) a.b         (with b treated as 24 bits)

            if (pp >= parts + 3 || val > 0xff)
                return (0);
            *pp++ = val, cp++;
        } else
            break;
    }

    // Check for trailing characters.

    if (*cp && (!isascii(*cp) || !isspace(*cp)))
        return (0);


    // Concoct the address according to the number of parts specified.

    n = pp - parts + 1;
    switch (n)
    {

    case 1:                    // a -- 32 bits
        break;

    case 2:                    //a.b -- 8.24 bits
        if (val > 0xffffff)
            return (0);
        val |= parts[0] << 24;
        break;

    case 3:                    //a.b.c -- 8.8.16 bits
        if (val > 0xffff)
            return (0);
        val |= (parts[0] << 24) | (parts[1] << 16);
        break;

    case 4:                    // a.b.c.d -- 8.8.8.8 bits
        if (val > 0xff)
            return (0);
        val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
        break;
    }
    if (addr)
        *addr = htonl(val);
    return (1);
}

int local_subnet_test(u_int32_t tmp_ip)
{
//printk("Comparing route: %s ",inet_ntoa(tmp_route->ip & tmp_route->netmask));
//printk(" to ip: %s\n", inet_ntoa(target_ip & tmp_route->netmask));




   /* if ((tmp_dev->ip & tmp_dev->netmask)  == (tmp_dev->netmask & tmp_ip ))
        return 1;
*/
//		    		printk("Comparing route: %s ",inet_ntoa(tmp_dev->ip & tmp_dev->netmask));
//		printk(" to ip: %s\n", inet_ntoa(tmp_ip & tmp_dev->netmask));

  return 0;
}


int aodv_subnet_test(u_int32_t tmp_ip)
{
    aodv_dev *tmp_dev;
//printk("Comparing route: %s ",inet_ntoa(tmp_route->ip & tmp_route->netmask));
//printk(" to ip: %s\n", inet_ntoa(target_ip & tmp_route->netmask));

    tmp_dev = first_aodv_dev();
 
    while (tmp_dev != NULL)
    {


    if ((tmp_dev->ip & tmp_dev->netmask)  == (tmp_dev->netmask & tmp_ip ))
        return 1;

         tmp_dev = tmp_dev->next;
		}
//		    		printk("Comparing route: %s ",inet_ntoa(tmp_dev->ip & tmp_dev->netmask));
//		printk(" to ip: %s\n", inet_ntoa(tmp_ip & tmp_dev->netmask));

  return 0;
}

u_int32_t calculate_netmask(int t)
{
    int i;
    uint32_t final = 0;

    for (i = 0; i < 32 - t; i++)
    {
        final = final + 1;
        final = final << 1;
    }

    final = final + 1;
    final = ~final;
    return final;

}

int calculate_prefix(u_int32_t t)
{
    int i = 1;

    while (t != 0)
    {
        t = t << 1;
        i++;
    }
    return i;
}

int seq_less_or_equal(u_int32_t seq_one,u_int32_t seq_two)
{
    int *comp_seq_one = &seq_one;
    int *comp_seq_two = &seq_two;

    if (  ( *comp_seq_one - *comp_seq_two ) > 0 )
    {
        return 0;
    }
    else
        return 1;
}

int seq_greater(u_int32_t seq_one,u_int32_t seq_two)
{
    int *comp_seq_one = &seq_one;
    int *comp_seq_two = &seq_two;

    if (  ( *comp_seq_one - *comp_seq_two ) < 0 )
        return 0;
    else
        return 1;
}