Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1 | /* |
| 2 | * dhcpcd - DHCP client daemon |
| 3 | * Copyright (c) 2006-2015 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 DUID_TIME_EPOCH 946684800 |
| 29 | #define DUID_LLT 1 |
| 30 | #define DUID_LL 3 |
| 31 | |
| 32 | #include <sys/socket.h> |
| 33 | #include <sys/types.h> |
| 34 | |
| 35 | #include <net/if.h> |
| 36 | #include <net/if_arp.h> |
| 37 | |
| 38 | #include <errno.h> |
| 39 | #include <stdio.h> |
| 40 | #include <stdlib.h> |
| 41 | #include <string.h> |
| 42 | #include <time.h> |
| 43 | #include <unistd.h> |
| 44 | |
| 45 | #ifndef ARPHRD_NETROM |
| 46 | # define ARPHRD_NETROM 0 |
| 47 | #endif |
| 48 | |
| 49 | #include "common.h" |
| 50 | #include "dhcpcd.h" |
| 51 | #include "duid.h" |
| 52 | |
| 53 | static size_t |
| 54 | duid_make(unsigned char *d, const struct interface *ifp, uint16_t type) |
| 55 | { |
| 56 | unsigned char *p; |
| 57 | uint16_t u16; |
| 58 | time_t t; |
| 59 | uint32_t u32; |
| 60 | |
| 61 | p = d; |
| 62 | u16 = htons(type); |
| 63 | memcpy(p, &u16, 2); |
| 64 | p += 2; |
| 65 | u16 = htons(ifp->family); |
| 66 | memcpy(p, &u16, 2); |
| 67 | p += 2; |
| 68 | if (type == DUID_LLT) { |
| 69 | /* time returns seconds from jan 1 1970, but DUID-LLT is |
| 70 | * seconds from jan 1 2000 modulo 2^32 */ |
| 71 | t = time(NULL) - DUID_TIME_EPOCH; |
| 72 | u32 = htonl((uint32_t)t & 0xffffffff); |
| 73 | memcpy(p, &u32, 4); |
| 74 | p += 4; |
| 75 | } |
| 76 | /* Finally, add the MAC address of the interface */ |
| 77 | memcpy(p, ifp->hwaddr, ifp->hwlen); |
| 78 | p += ifp->hwlen; |
| 79 | return (size_t)(p - d); |
| 80 | } |
| 81 | |
| 82 | #define DUID_STRLEN DUID_LEN * 3 |
| 83 | static size_t |
| 84 | duid_get(unsigned char *d, const struct interface *ifp) |
| 85 | { |
| 86 | FILE *fp; |
| 87 | int x = 0; |
| 88 | size_t len = 0; |
| 89 | char line[DUID_STRLEN]; |
| 90 | const struct interface *ifp2; |
| 91 | |
| 92 | /* If we already have a DUID then use it as it's never supposed |
| 93 | * to change once we have one even if the interfaces do */ |
| 94 | if ((fp = fopen(DUID, "r"))) { |
| 95 | while (fgets(line, DUID_STRLEN, fp)) { |
| 96 | len = strlen(line); |
| 97 | if (len) { |
| 98 | if (line[len - 1] == '\n') |
| 99 | line[len - 1] = '\0'; |
| 100 | } |
| 101 | len = hwaddr_aton(NULL, line); |
| 102 | if (len && len <= DUID_LEN) { |
| 103 | hwaddr_aton(d, line); |
| 104 | break; |
| 105 | } |
| 106 | len = 0; |
| 107 | } |
| 108 | fclose(fp); |
| 109 | if (len) |
| 110 | return len; |
| 111 | } else { |
| 112 | if (errno != ENOENT) |
| 113 | logger(ifp->ctx, LOG_ERR, |
| 114 | "error reading DUID: %s: %m", DUID); |
| 115 | } |
| 116 | |
| 117 | /* No file? OK, lets make one based on our interface */ |
| 118 | if (ifp->family == ARPHRD_NETROM) { |
| 119 | logger(ifp->ctx, LOG_WARNING, |
| 120 | "%s: is a NET/ROM psuedo interface", ifp->name); |
| 121 | TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) { |
| 122 | if (ifp2->family != ARPHRD_NETROM) |
| 123 | break; |
| 124 | } |
| 125 | if (ifp2) { |
| 126 | ifp = ifp2; |
| 127 | logger(ifp->ctx, LOG_WARNING, |
| 128 | "picked interface %s to generate a DUID", |
| 129 | ifp->name); |
| 130 | } else { |
| 131 | logger(ifp->ctx, LOG_WARNING, |
| 132 | "no interfaces have a fixed hardware address"); |
| 133 | return duid_make(d, ifp, DUID_LL); |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | if (!(fp = fopen(DUID, "w"))) { |
| 138 | logger(ifp->ctx, LOG_ERR, "error writing DUID: %s: %m", DUID); |
| 139 | return duid_make(d, ifp, DUID_LL); |
| 140 | } |
| 141 | len = duid_make(d, ifp, DUID_LLT); |
| 142 | x = fprintf(fp, "%s\n", hwaddr_ntoa(d, len, line, sizeof(line))); |
| 143 | fclose(fp); |
| 144 | /* Failed to write the duid? scrub it, we cannot use it */ |
| 145 | if (x < 1) { |
| 146 | logger(ifp->ctx, LOG_ERR, "error writing DUID: %s: %m", DUID); |
| 147 | unlink(DUID); |
| 148 | return duid_make(d, ifp, DUID_LL); |
| 149 | } |
| 150 | return len; |
| 151 | } |
| 152 | |
| 153 | size_t duid_init(const struct interface *ifp) |
| 154 | { |
| 155 | |
| 156 | if (ifp->ctx->duid == NULL) { |
| 157 | ifp->ctx->duid = malloc(DUID_LEN); |
| 158 | if (ifp->ctx->duid == NULL) { |
| 159 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 160 | return 0; |
| 161 | } |
| 162 | ifp->ctx->duid_len = duid_get(ifp->ctx->duid, ifp); |
| 163 | } |
| 164 | return ifp->ctx->duid_len; |
| 165 | } |