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#include <errno.h>
#include <string.h>
#include <arpa/inet.h>
#include <linux/types.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/rtnetlink.h>
#include <syslog.h>
#include "netlink_utils.hh"
/* Maskbit. */
static u_char maskbit[] = {0x00, 0x80, 0xc0, 0xe0, 0xf0,
0xf8, 0xfc, 0xfe, 0xff};
/* Convert masklen into IP address's netmask. */
void
masklen2ip (int masklen, struct in_addr *netmask)
{
u_char *pnt;
int bit;
int offset;
memset (netmask, 0, sizeof (struct in_addr));
pnt = (unsigned char *) netmask;
offset = masklen / 8;
bit = masklen % 8;
while (offset--)
*pnt++ = 0xff;
if (bit)
*pnt = maskbit[bit];
}
in_addr_t
ipv4_broadcast_addr (in_addr_t hostaddr, int masklen)
{
struct in_addr mask;
masklen2ip (masklen, &mask);
return (masklen != 32-1) ?
/* normal case */
(hostaddr | ~mask.s_addr) :
/* special case for /31 */
(hostaddr ^ ~mask.s_addr);
}
in_addr_t
ipv4_first_addr (in_addr_t hostaddr, int masklen)
{
struct in_addr mask;
masklen2ip (masklen, &mask);
return (hostaddr & mask.s_addr);
}
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