xref: /freebsd/usr.sbin/wake/wake.c (revision 409a390c3341fb4f162cd7de1fd595a323ebbfd8)
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("$FreeBSD$");
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 
55 static int	bind_if_to_bpf(char const *ifname, int bpf);
56 static int	get_ether(char const *text, struct ether_addr *addr);
57 static int	send_wakeup(int bpf, struct ether_addr const *addr);
58 static void	usage(void);
59 static int	wake(const char *iface, const char *host);
60 
61 static void
62 usage(void)
63 {
64 
65 	(void)fprintf(stderr, "usage: wake interface lladdr [lladdr ...]\n");
66 	exit(1);
67 }
68 
69 static int
70 wake(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 
90 static int
91 bind_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 
116 static int
117 get_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 
133 static int
134 send_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 
165 int
166 main(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