Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <ip.h>

/*
 *  well known IP addresses
 */
uchar IPv4bcast[IPaddrlen] = {
        0, 0, 0, 0,
        0, 0, 0, 0,
        0, 0, 0xff, 0xff,
        0xff, 0xff, 0xff, 0xff
};
uchar IPv4allsys[IPaddrlen] = {
        0, 0, 0, 0,
        0, 0, 0, 0,
        0, 0, 0xff, 0xff,
        0xe0, 0, 0, 0x01
};
uchar IPv4allrouter[IPaddrlen] = {
        0, 0, 0, 0,
        0, 0, 0, 0,
        0, 0, 0xff, 0xff,
        0xe0, 0, 0, 0x02
};
uchar IPallbits[IPaddrlen] = {
        0xff, 0xff, 0xff, 0xff,
        0xff, 0xff, 0xff, 0xff,
        0xff, 0xff, 0xff, 0xff,
        0xff, 0xff, 0xff, 0xff
};
uchar IPnoaddr[IPaddrlen];

/*
 *  prefix of all v4 addresses
 */
uchar v4prefix[IPaddrlen] = {
        0, 0, 0, 0,
        0, 0, 0, 0,
        0, 0, 0xff, 0xff,
        0, 0, 0, 0
};

int
isv4(uchar *ip)
{
        return memcmp(ip, v4prefix, IPv4off) == 0;
}

/*
 *  the following routines are unrolled with no memset's to speed
 *  up the usual case
 */
void
v4tov6(uchar *v6, uchar *v4)
{
        v6[0] = 0;
        v6[1] = 0;
        v6[2] = 0;
        v6[3] = 0;
        v6[4] = 0;
        v6[5] = 0;
        v6[6] = 0;
        v6[7] = 0;
        v6[8] = 0;
        v6[9] = 0;
        v6[10] = 0xff;
        v6[11] = 0xff;
        v6[12] = v4[0];
        v6[13] = v4[1];
        v6[14] = v4[2];
        v6[15] = v4[3];
}

int
v6tov4(uchar *v4, uchar *v6)
{
        if(v6[0] == 0
        && v6[1] == 0
        && v6[2] == 0
        && v6[3] == 0
        && v6[4] == 0
        && v6[5] == 0
        && v6[6] == 0
        && v6[7] == 0
        && v6[8] == 0
        && v6[9] == 0
        && v6[10] == 0xff
        && v6[11] == 0xff)
        {
                v4[0] = v6[12];
                v4[1] = v6[13];
                v4[2] = v6[14];
                v4[3] = v6[15];
                return 0;
        } else {
                memset(v4, 0, 4);
                if(memcmp(v6, IPnoaddr, IPaddrlen) == 0)
                        return 0;
                return -1;
        }
}