| Dmitry Shmidt | e86eee1 | 2011-01-24 16:27:51 -0800 | [diff] [blame] | 1 | /* |
| 2 | * dhcpcd - DHCP client daemon |
| 3 | * Copyright (c) 2006-2008 Roy Marples <roy@marples.name> |
| 4 | * All rights reserved |
| 5 | |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 16 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 19 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 20 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 21 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 22 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 23 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 24 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 25 | * SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #define THIRTY_YEARS_IN_SECONDS 946707779 |
| 29 | |
| 30 | #include <errno.h> |
| 31 | #include <stdio.h> |
| 32 | #include <stdlib.h> |
| 33 | #include <string.h> |
| 34 | #include <time.h> |
| 35 | #include <unistd.h> |
| 36 | |
| 37 | #include "common.h" |
| 38 | #include "duid.h" |
| 39 | #include "net.h" |
| 40 | |
| 41 | size_t |
| 42 | get_duid(unsigned char *duid, const struct interface *iface) |
| 43 | { |
| 44 | FILE *f; |
| 45 | uint16_t type = 0; |
| 46 | uint16_t hw = 0; |
| 47 | uint32_t ul; |
| 48 | time_t t; |
| 49 | int x = 0; |
| 50 | unsigned char *p = duid; |
| 51 | size_t len = 0; |
| 52 | char *line; |
| 53 | |
| 54 | /* If we already have a DUID then use it as it's never supposed |
| 55 | * to change once we have one even if the interfaces do */ |
| 56 | if ((f = fopen(DUID, "r"))) { |
| 57 | while ((line = get_line(f))) { |
| 58 | len = hwaddr_aton(NULL, line); |
| 59 | if (len && len <= DUID_LEN) { |
| 60 | hwaddr_aton(duid, line); |
| 61 | break; |
| 62 | } |
| 63 | len = 0; |
| 64 | } |
| 65 | fclose(f); |
| 66 | if (len) |
| 67 | return len; |
| 68 | } else { |
| 69 | if (errno != ENOENT) |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | /* No file? OK, lets make one based on our interface */ |
| 74 | if (!(f = fopen(DUID, "w"))) |
| 75 | return 0; |
| 76 | type = htons(1); /* DUI-D-LLT */ |
| 77 | memcpy(p, &type, 2); |
| 78 | p += 2; |
| 79 | hw = htons(iface->family); |
| 80 | memcpy(p, &hw, 2); |
| 81 | p += 2; |
| 82 | /* time returns seconds from jan 1 1970, but DUID-LLT is |
| 83 | * seconds from jan 1 2000 modulo 2^32 */ |
| 84 | t = time(NULL) - THIRTY_YEARS_IN_SECONDS; |
| 85 | ul = htonl(t & 0xffffffff); |
| 86 | memcpy(p, &ul, 4); |
| 87 | p += 4; |
| 88 | /* Finally, add the MAC address of the interface */ |
| 89 | memcpy(p, iface->hwaddr, iface->hwlen); |
| 90 | p += iface->hwlen; |
| 91 | len = p - duid; |
| 92 | x = fprintf(f, "%s\n", hwaddr_ntoa(duid, len)); |
| 93 | fclose(f); |
| 94 | /* Failed to write the duid? scrub it, we cannot use it */ |
| 95 | if (x < 1) { |
| 96 | len = 0; |
| 97 | unlink(DUID); |
| 98 | } |
| 99 | return len; |
| 100 | } |