diff options
Diffstat (limited to 'duid.c')
| -rw-r--r-- | duid.c | 100 |
1 files changed, 100 insertions, 0 deletions
@@ -0,0 +1,100 @@ +/* + * 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; +} |