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/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2006-2008 Roy Marples <roy@marples.name>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*/
#define THIRTY_YEARS_IN_SECONDS 946707779
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "common.h"
#include "duid.h"
#include "net.h"
size_t
get_duid(unsigned char *duid, const struct interface *iface)
{
FILE *f;
uint16_t type = 0;
uint16_t hw = 0;
uint32_t ul;
time_t t;
int x = 0;
unsigned char *p = duid;
size_t len = 0;
char *line;
/* If we already have a DUID then use it as it's never supposed
* to change once we have one even if the interfaces do */
if ((f = fopen(DUID, "r"))) {
while ((line = get_line(f))) {
len = hwaddr_aton(NULL, line);
if (len && len <= DUID_LEN) {
hwaddr_aton(duid, line);
break;
}
len = 0;
}
fclose(f);
if (len)
return len;
} else {
if (errno != ENOENT)
return 0;
}
/* No file? OK, lets make one based on our interface */
if (!(f = fopen(DUID, "w")))
return 0;
type = htons(1); /* DUI-D-LLT */
memcpy(p, &type, 2);
p += 2;
hw = htons(iface->family);
memcpy(p, &hw, 2);
p += 2;
/* time returns seconds from jan 1 1970, but DUID-LLT is
* seconds from jan 1 2000 modulo 2^32 */
t = time(NULL) - THIRTY_YEARS_IN_SECONDS;
ul = htonl(t & 0xffffffff);
memcpy(p, &ul, 4);
p += 4;
/* Finally, add the MAC address of the interface */
memcpy(p, iface->hwaddr, iface->hwlen);
p += iface->hwlen;
len = p - duid;
x = fprintf(f, "%s\n", hwaddr_ntoa(duid, len));
fclose(f);
/* Failed to write the duid? scrub it, we cannot use it */
if (x < 1) {
len = 0;
unlink(DUID);
}
return len;
}
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