/* $NetBSD: wakeonlan.c,v 1.2 2012/12/15 04:40:33 jakllsch Exp $ */

/* $NetBSD: wakeonlan.c,v 1.2 2012/12/15 04:40:33 jakllsch Exp $ */

/*
* Copyright (C) 2006, 2007, 2008, 2009, 2010 Marc Balmer <[email protected]>
* Copyright (C) 2000 Eugene M. Kim. 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. Author's name may not be used endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/

/* Send Wake on LAN packets to hosts on a local Ethernet network */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <net/bpf.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <ifaddrs.h>
#include <limits.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#ifndef SYNC_LEN
#define SYNC_LEN 6
#endif

#ifndef DESTADDR_COUNT
#define DESTADDR_COUNT 16
#endif

__dead static void usage(void);
static int wake(int, const char *);
static int bind_if_to_bpf(char const *, int);
static int find_ether(char *, size_t);
static int get_ether(char const *, struct ether_addr *);
static int send_wakeup(int, struct ether_addr const *);

static void
usage(void)
{
fprintf(stderr, "usage: %s [interface] lladdr [lladdr ...]\n",
getprogname());
exit(EXIT_FAILURE);
}

static int
wake(int bpf, const char *host)
{
struct ether_addr macaddr;

if (get_ether(host, &macaddr) == -1)
return -1;

return send_wakeup(bpf, &macaddr);
}

static int
bind_if_to_bpf(char const *ifname, int bpf)
{
struct ifreq ifr;
u_int dlt;

if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
sizeof(ifr.ifr_name)) {
errno = ENAMETOOLONG;
return -1;
}
if (ioctl(bpf, BIOCSETIF, &ifr) == -1)
return -1;
if (ioctl(bpf, BIOCGDLT, &dlt) == -1)
return -1;
if (dlt != DLT_EN10MB) {
errno = EOPNOTSUPP;
return -1;
}
return 0;
}

static int
find_ether(char *dst, size_t len)
{
struct ifaddrs *ifap, *ifa;
struct sockaddr_dl *sdl = NULL;
int nifs;

if (dst == NULL || len == 0)
return 0;

if (getifaddrs(&ifap) != 0)
return -1;

/* XXX also check the link state */
for (nifs = 0, ifa = ifap; ifa; ifa = ifa->ifa_next)
if (ifa->ifa_addr->sa_family == AF_LINK &&
ifa->ifa_flags & IFF_UP && ifa->ifa_flags & IFF_RUNNING) {
sdl = (struct sockaddr_dl *)ifa->ifa_addr;
if (sdl->sdl_type == IFT_ETHER) {
strlcpy(dst, ifa->ifa_name, len);
nifs++;
}
}

freeifaddrs(ifap);
return nifs == 1 ? 0 : -1;
}

static int
get_ether(char const *text, struct ether_addr *addr)
{
struct ether_addr *paddr;

paddr = ether_aton(text);
if (paddr != NULL) {
*addr = *paddr;
return 0;
}
if (ether_hostton(text, addr))
return -1;
return 0;
}

static int
send_wakeup(int bpf, struct ether_addr const *addr)
{
struct {
struct ether_header hdr;
u_char data[SYNC_LEN + ETHER_ADDR_LEN * DESTADDR_COUNT];
} pkt;
u_char *p;
int i;
ssize_t bw, len;

memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
memset(pkt.hdr.ether_shost, 0x00, sizeof(pkt.hdr.ether_shost));
pkt.hdr.ether_type = htons(0);
memset(pkt.data, 0xff, SYNC_LEN);
for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT;
p += ETHER_ADDR_LEN, i++)
memcpy(p, addr->ether_addr_octet, ETHER_ADDR_LEN);
p = (u_char *)(void *)&pkt;
len = sizeof(pkt);
bw = 0;
while (len) {
if ((bw = write(bpf, p, len)) == -1)
return -1;
len -= bw;
p += bw;
}
return 0;
}

int
main(int argc, char *argv[])
{
int bpf, n;
char ifname[IF_NAMESIZE];

if (argc < 2)
usage();

if ((bpf = open(_PATH_BPF, O_RDWR)) == -1)
err(EXIT_FAILURE, "Cannot open bpf interface");

n = 2;
if (bind_if_to_bpf(argv[1], bpf) == -1) {
if (find_ether(ifname, sizeof(ifname)))
err(EXIT_FAILURE, "Failed to determine ethernet "
"interface");
if (bind_if_to_bpf(ifname, bpf) == -1)
err(EXIT_FAILURE, "Cannot bind to interface `%s'",
ifname);
--n;
} else
strlcpy(ifname, argv[1], sizeof(ifname));

if (n >= argc)
usage();
for (; n < argc; n++)
if (wake(bpf, argv[n]))
warn("Cannot send Wake on LAN frame over `%s' to `%s'",
ifname, argv[n]);
return EXIT_SUCCESS;
}