text: /*
   * Copyright (C) 2006, 2007, 2008, 2009, 2010 Marc Balmer <marc@msys.ch>
   * 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.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD$");
  
  #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 <fcntl.h>
  #include <ifaddrs.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #define	_PATH_BPF	"/dev/bpf"
  
  #ifndef SYNC_LEN
  #define	SYNC_LEN	6
  #endif
  
  #ifndef DESTADDR_COUNT
  #define	DESTADDR_COUNT	16
  #endif
  
  static int	bind_if_to_bpf(char const *ifname, int bpf);
  static int	find_ether(char *dst, size_t len);
  static int	get_ether(char const *text, struct ether_addr *addr);
  static int	send_wakeup(int bpf, struct ether_addr const *addr);
  static void	usage(void);
  static int	wake(int bpf, const char *host);
  
  static void
  usage(void)
  {
  
  	(void)fprintf(stderr, "usage: wake [interface] lladdr [lladdr ...]\n");
  	exit(1);
  }
  
  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))
  		return (-1);
  
  	if (ioctl(bpf, BIOCSETIF, &ifr) == -1)
  		return (-1);
  
  	if (ioctl(bpf, BIOCGDLT, &dlt) == -1)
  		return (-1);
  
  	if (dlt != DLT_EN10MB)
  		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)) {
  		warnx("no match for host %s found", text);
  		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];
  	} __packed pkt;
  	u_char *p;
  	ssize_t bw;
  	ssize_t len;
  	int i;
  
  	(void)memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
  	pkt.hdr.ether_type = htons(0);
  	(void)memset(pkt.data, 0xff, SYNC_LEN);
  	for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT;
  	    p += ETHER_ADDR_LEN, i++)
  		bcopy(addr->octet, p, ETHER_ADDR_LEN);
  	p = (u_char *)&pkt;
  	len = sizeof(pkt);
  	bw = 0;
  	while (len) {
  		if ((bw = write(bpf, p, len)) == -1) {
  			warn("write()");
  			return (-1);
  		}
  		len -= bw;
  		p += bw;
  	}
  	return (0);
  }
  
  int
  main(int argc, char *argv[])
  {
  	int bpf, n, rval;
  	char ifname[IF_NAMESIZE];
  
  	if (argc < 2)
  		usage();
  
  	if ((bpf = open(_PATH_BPF, O_RDWR)) == -1)
  		err(1, "Cannot open bpf interface");
  
  	n = 2;
  	if (bind_if_to_bpf(argv[1], bpf) == -1) {
  		if (find_ether(ifname, sizeof(ifname)))
  			err(1, "Failed to determine ethernet interface");
  		if (bind_if_to_bpf(ifname, bpf) == -1)
  			err(1, "Cannot bind to interface `%s'", ifname);
  		--n;
  	} else
  		strlcpy(ifname, argv[1], sizeof(ifname));
  
  	if (n >= argc)
  		usage();
  	rval = 0;
  	for (; n < argc; n++) {
  		if (wake(bpf, argv[n]) != 0) {
  			rval = 1;
  			warn("Cannot send Wake on LAN frame over `%s' to `%s'",
  			    ifname, argv[n]);
  		}
  	}
  	exit(rval);
  }
  