wake.c revision 201024 
1/*
2 * Copyright (C) 2006, 2007, 2008, 2009 Marc Balmer <marc@msys.ch>
3 * Copyright (C) 2000 Eugene M. Kim.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Author's name may not be used endorse or promote products derived
12 *    from this software without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
18 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/usr.sbin/wake/wake.c 201024 2009-12-26 18:03:16Z rwatson $");
29
30#include <sys/ioctl.h>
31#include <sys/socket.h>
32#include <sys/time.h>
33#include <net/bpf.h>
34#include <net/if.h>
35#include <netinet/in.h>
36#include <netinet/if_ether.h>
37
38#include <err.h>
39#include <fcntl.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44
45#define	_PATH_BPF	"/dev/bpf"
46
47#ifndef SYNC_LEN
48#define	SYNC_LEN	6
49#endif
50
51#ifndef DESTADDR_COUNT
52#define	DESTADDR_COUNT	16
53#endif
54
55static int	bind_if_to_bpf(char const *ifname, int bpf);
56static int	get_ether(char const *text, struct ether_addr *addr);
57static int	send_wakeup(int bpf, struct ether_addr const *addr);
58static void	usage(void);
59static int	wake(const char *iface, const char *host);
60
61static void
62usage(void)
63{
64
65	(void)fprintf(stderr, "usage: wake interface lladdr [lladdr ...]\n");
66	exit(1);
67}
68
69static int
70wake(const char *iface, const char *host)
71{
72	struct ether_addr macaddr;
73	int bpf, res;
74
75	bpf = open(_PATH_BPF, O_RDWR);
76	if (bpf == -1) {
77		warn("no bpf");
78		return (-1);
79	}
80	if (bind_if_to_bpf(iface, bpf) == -1 ||
81	    get_ether(host, &macaddr) == -1) {
82		(void)close(bpf);
83		return (-1);
84	}
85	res = send_wakeup(bpf, &macaddr);
86	(void)close(bpf);
87	return (res);
88}
89
90static int
91bind_if_to_bpf(char const *ifname, int bpf)
92{
93	struct ifreq ifr;
94	u_int dlt;
95
96	if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
97	    sizeof(ifr.ifr_name)) {
98		warnx("interface name too long: %s", ifname);
99		return (-1);
100	}
101	if (ioctl(bpf, BIOCSETIF, &ifr) == -1) {
102		warn("ioctl(%s)", "BIOCSETIF");
103		return (-1);
104	}
105	if (ioctl(bpf, BIOCGDLT, &dlt) == -1) {
106		warn("ioctl(%s)", "BIOCGDLT");
107		return (-1);
108	}
109	if (dlt != DLT_EN10MB) {
110		warnx("incompatible media");
111		return (-1);
112	}
113	return (0);
114}
115
116static int
117get_ether(char const *text, struct ether_addr *addr)
118{
119	struct ether_addr *paddr;
120
121	paddr = ether_aton(text);
122	if (paddr != NULL) {
123		*addr = *paddr;
124		return (0);
125	}
126	if (ether_hostton(text, addr)) {
127		warnx("no match for host %s found", text);
128		return (-1);
129	}
130	return (0);
131}
132
133static int
134send_wakeup(int bpf, struct ether_addr const *addr)
135{
136	struct {
137		struct ether_header hdr;
138		u_char data[SYNC_LEN + ETHER_ADDR_LEN * DESTADDR_COUNT];
139	} __packed pkt;
140	u_char *p;
141	ssize_t bw;
142	ssize_t len;
143	int i;
144
145	(void)memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
146	pkt.hdr.ether_type = htons(0);
147	(void)memset(pkt.data, 0xff, SYNC_LEN);
148	for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT;
149	    p += ETHER_ADDR_LEN, i++)
150		bcopy(addr->octet, p, ETHER_ADDR_LEN);
151	p = (u_char *)&pkt;
152	len = sizeof(pkt);
153	bw = 0;
154	while (len) {
155		if ((bw = write(bpf, p, len)) == -1) {
156			warn("write()");
157			return (-1);
158		}
159		len -= bw;
160		p += bw;
161	}
162	return (0);
163}
164
165int
166main(int argc, char *argv[])
167{
168	int n;
169
170	if (argc < 3)
171		usage();
172
173	for (n = 2; n < argc; n++)
174		if (wake(argv[1], argv[n]))
175			warnx("error sending Wake on LAN frame over %s to %s",
176			    argv[1], argv[n]);
177	return (0);
178}
179