diff options
Diffstat (limited to 'dhcpcd/duid.c')
| -rw-r--r-- | dhcpcd/duid.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/dhcpcd/duid.c b/dhcpcd/duid.c new file mode 100644 index 00000000..a119828f --- /dev/null +++ b/dhcpcd/duid.c @@ -0,0 +1,162 @@ +/* + * dhcpcd - DHCP client daemon + * Copyright (c) 2006-2013 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 DUID_TIME_EPOCH 946684800 +#define DUID_LLT 1 +#define DUID_LL 3 + +#include <sys/socket.h> +#include <sys/types.h> + +#include <net/if.h> +#include <net/if_arp.h> + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syslog.h> +#include <time.h> +#include <unistd.h> + +#ifndef ARPHRD_NETROM +# define ARPHRD_NETROM 0 +#endif + +#include "common.h" +#include "duid.h" +#include "net.h" + +unsigned char *duid = NULL; +size_t duid_len = 0; + +static size_t +duid_make(unsigned char *d, const struct interface *ifp, uint16_t type) +{ + unsigned char *p; + uint16_t u16; + time_t t; + uint32_t u32; + + p = d; + u16 = htons(type); + memcpy(p, &u16, 2); + p += 2; + u16 = htons(ifp->family); + memcpy(p, &u16, 2); + p += 2; + if (type == DUID_LLT) { + /* time returns seconds from jan 1 1970, but DUID-LLT is + * seconds from jan 1 2000 modulo 2^32 */ + t = time(NULL) - DUID_TIME_EPOCH; + u32 = htonl(t & 0xffffffff); + memcpy(p, &u32, 4); + p += 4; + } + /* Finally, add the MAC address of the interface */ + memcpy(p, ifp->hwaddr, ifp->hwlen); + p += ifp->hwlen; + return p - d; +} + +static size_t +duid_get(unsigned char *d, const struct interface *ifp) +{ + FILE *f; + int x = 0; + size_t len = 0; + char *line; + const struct interface *ifp2; + + /* 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(d, line); + break; + } + len = 0; + } + fclose(f); + if (len) + return len; + } else { + if (errno != ENOENT) + syslog(LOG_ERR, "error reading DUID: %s: %m", DUID); + } + + /* No file? OK, lets make one based on our interface */ + if (ifp->family == ARPHRD_NETROM) { + syslog(LOG_WARNING, "%s: is a NET/ROM psuedo interface", + ifp->name); + TAILQ_FOREACH(ifp2, ifaces, next) { + if (ifp2->family != ARPHRD_NETROM) + break; + } + if (ifp2) { + ifp = ifp2; + syslog(LOG_WARNING, + "picked interface %s to generate a DUID", + ifp->name); + } else { + syslog(LOG_WARNING, + "no interfaces have a fixed hardware address"); + return duid_make(d, ifp, DUID_LL); + } + } + + if (!(f = fopen(DUID, "w"))) { + syslog(LOG_ERR, "error writing DUID: %s: %m", DUID); + return duid_make(d, ifp, DUID_LL); + } + len = duid_make(d, ifp, DUID_LLT); + x = fprintf(f, "%s\n", hwaddr_ntoa(d, len)); + fclose(f); + /* Failed to write the duid? scrub it, we cannot use it */ + if (x < 1) { + syslog(LOG_ERR, "error writing DUID: %s: %m", DUID); + unlink(DUID); + return duid_make(d, ifp, DUID_LL); + } + return len; +} + +size_t duid_init(const struct interface *ifp) +{ + + if (duid == NULL) { + duid = malloc(DUID_LEN); + if (duid == NULL) { + syslog(LOG_ERR, "%s: %m", __func__); + return 0; + } + duid_len = duid_get(duid, ifp); + } + return duid_len; +} |