xref: /freebsd/usr.sbin/wake/wake.c (revision cf7d8dea39cb00887476ad1a42480bce00b0b842)
1 /*
2  * Copyright (C) 2006, 2007, 2008, 2009, 2010 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 <net/if_dl.h>
36 #include <net/if_types.h>
37 #include <netinet/in.h>
38 #include <netinet/if_ether.h>
39 
40 #include <err.h>
41 #include <fcntl.h>
42 #include <ifaddrs.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #define	_PATH_BPF	"/dev/bpf"
49 
50 #ifndef SYNC_LEN
51 #define	SYNC_LEN	6
52 #endif
53 
54 #ifndef DESTADDR_COUNT
55 #define	DESTADDR_COUNT	16
56 #endif
57 
58 static int	bind_if_to_bpf(char const *ifname, int bpf);
59 static int	find_ether(char *dst, size_t len);
60 static int	get_ether(char const *text, struct ether_addr *addr);
61 static int	send_wakeup(int bpf, struct ether_addr const *addr);
62 static void	usage(void);
63 static int	wake(int bpf, const char *host);
64 
65 static void
66 usage(void)
67 {
68 
69 	(void)fprintf(stderr, "usage: wake [interface] lladdr [lladdr ...]\n");
70 	exit(1);
71 }
72 
73 static int
74 wake(int bpf, const char *host)
75 {
76 	struct ether_addr macaddr;
77 
78 	if (get_ether(host, &macaddr) == -1)
79 		return (-1);
80 
81 	return send_wakeup(bpf, &macaddr);
82 }
83 
84 static int
85 bind_if_to_bpf(char const *ifname, int bpf)
86 {
87 	struct ifreq ifr;
88 	u_int dlt;
89 
90 	if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
91 	    sizeof(ifr.ifr_name))
92 		return (-1);
93 
94 	if (ioctl(bpf, BIOCSETIF, &ifr) == -1)
95 		return (-1);
96 
97 	if (ioctl(bpf, BIOCGDLT, &dlt) == -1)
98 		return (-1);
99 
100 	if (dlt != DLT_EN10MB)
101 		return (-1);
102 
103 	return (0);
104 }
105 
106 static int
107 find_ether(char *dst, size_t len)
108 {
109 	struct ifaddrs *ifap, *ifa;
110 	struct sockaddr_dl *sdl = NULL;
111 	int nifs;
112 
113 	if (dst == NULL || len == 0)
114 		return 0;
115 
116 	if (getifaddrs(&ifap) != 0)
117 		return -1;
118 
119 	/* XXX also check the link state */
120 	for (nifs = 0, ifa = ifap; ifa; ifa = ifa->ifa_next)
121 		if (ifa->ifa_addr->sa_family == AF_LINK &&
122 		    ifa->ifa_flags & IFF_UP && ifa->ifa_flags & IFF_RUNNING) {
123 			sdl = (struct sockaddr_dl *)ifa->ifa_addr;
124 			if (sdl->sdl_type == IFT_ETHER) {
125 				strlcpy(dst, ifa->ifa_name, len);
126 				nifs++;
127 			}
128 		}
129 
130 	freeifaddrs(ifap);
131 	return nifs == 1 ? 0 : -1;
132 }
133 
134 static int
135 get_ether(char const *text, struct ether_addr *addr)
136 {
137 	struct ether_addr *paddr;
138 
139 	paddr = ether_aton(text);
140 	if (paddr != NULL) {
141 		*addr = *paddr;
142 		return (0);
143 	}
144 	if (ether_hostton(text, addr)) {
145 		warnx("no match for host %s found", text);
146 		return (-1);
147 	}
148 	return (0);
149 }
150 
151 static int
152 send_wakeup(int bpf, struct ether_addr const *addr)
153 {
154 	struct {
155 		struct ether_header hdr;
156 		u_char data[SYNC_LEN + ETHER_ADDR_LEN * DESTADDR_COUNT];
157 	} __packed pkt;
158 	u_char *p;
159 	ssize_t bw;
160 	ssize_t len;
161 	int i;
162 
163 	(void)memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
164 	pkt.hdr.ether_type = htons(0);
165 	(void)memset(pkt.data, 0xff, SYNC_LEN);
166 	for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT;
167 	    p += ETHER_ADDR_LEN, i++)
168 		bcopy(addr->octet, p, ETHER_ADDR_LEN);
169 	p = (u_char *)&pkt;
170 	len = sizeof(pkt);
171 	bw = 0;
172 	while (len) {
173 		if ((bw = write(bpf, p, len)) == -1) {
174 			warn("write()");
175 			return (-1);
176 		}
177 		len -= bw;
178 		p += bw;
179 	}
180 	return (0);
181 }
182 
183 int
184 main(int argc, char *argv[])
185 {
186 	int bpf, n;
187 	char ifname[IF_NAMESIZE];
188 
189 	if (argc < 2)
190 		usage();
191 
192 	if ((bpf = open(_PATH_BPF, O_RDWR)) == -1)
193 		err(1, "Cannot open bpf interface");
194 
195 	n = 2;
196 	if (bind_if_to_bpf(argv[1], bpf) == -1) {
197 		if (find_ether(ifname, sizeof(ifname)))
198 			err(1, "Failed to determine ethernet interface");
199 		if (bind_if_to_bpf(ifname, bpf) == -1)
200 			err(1, "Cannot bind to interface `%s'", ifname);
201 		--n;
202 	} else
203 		strlcpy(ifname, argv[1], sizeof(ifname));
204 
205 	if (n >= argc)
206 		usage();
207 	for (; n < argc; n++)
208 		if (wake(bpf, argv[n]))
209 			warn("Cannot send Wake on LAN frame over `%s' to `%s'",
210 			    ifname, argv[n]);
211 
212 	return (0);
213 }
214