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/*
* Copyright (c) 2019 Nikos Mavrogiannopoulos
* Copyright 1991-1997, 1999-2014 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
/* Adds the two IP addresses and places the output in ap. This is based
* on Niels Moeller's mini-gmp. */
void ipv6_add(struct in6_addr *ap, const struct in6_addr *bp)
{
int i;
uint8_t cy;
for (i = 15, cy = 0; i >= 0; i--) {
uint8_t a, b, r;
a = ap->s6_addr[i];
b = bp->s6_addr[i];
r = a + cy;
cy = (r < cy);
r += b;
cy += (r < b);
ap->s6_addr[i] = r;
}
return;
}
/* Sets the "bit" of the IPv6 address to one */
void ipv6_or1(struct in6_addr *a, unsigned bit)
{
unsigned byte = bit / 8;
unsigned shift = bit % 8;
assert(bit < 128);
a->s6_addr[15 - byte] |= 1 << shift;
}
/* Sets all bits below "bits" to one */
void ipv6_orm(struct in6_addr *a, unsigned bits)
{
int i;
unsigned bytes = bits / 8;
assert(bits < 128);
for (i = 0; i < bytes; i++)
a->s6_addr[15 - i] |= 0xff;
for (i = bytes * 8; i < bits; i++)
ipv6_or1(a, i);
}
/* Returns 1 if IP a is greater than IP b, 0 if equal, -1 if less */
int ipv6_cmp(struct in6_addr *a, struct in6_addr *b)
{
unsigned i;
for (i = 0; i < 16; i++) {
if (a->s6_addr[i] != b->s6_addr[i])
return a->s6_addr[i] > b->s6_addr[i] ? 1 : -1;
}
return 0;
}
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