xref: /freebsd/usr.sbin/wake/wake.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Marc Balmer <marc@msys.ch>
5  * Copyright (C) 2000 Eugene M. Kim.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Author's name may not be used endorse or promote products derived
14  *    from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/ioctl.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35 #include <net/bpf.h>
36 #include <net/if.h>
37 #include <net/if_dl.h>
38 #include <net/if_types.h>
39 #include <netinet/in.h>
40 #include <netinet/if_ether.h>
41 
42 #include <err.h>
43 #include <fcntl.h>
44 #include <ifaddrs.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #define	_PATH_BPF	"/dev/bpf"
51 
52 #ifndef SYNC_LEN
53 #define	SYNC_LEN	6
54 #endif
55 
56 #ifndef DESTADDR_COUNT
57 #define	DESTADDR_COUNT	16
58 #endif
59 
60 static int	bind_if_to_bpf(char const *ifname, int bpf);
61 static int	find_ether(char *dst, size_t len);
62 static int	get_ether(char const *text, struct ether_addr *addr);
63 static int	send_wakeup(int bpf, struct ether_addr const *addr);
64 static void	usage(void);
65 static int	wake(int bpf, const char *host);
66 
67 static void
68 usage(void)
69 {
70 
71 	(void)fprintf(stderr, "usage: wake [interface] lladdr [lladdr ...]\n");
72 	exit(1);
73 }
74 
75 static int
76 wake(int bpf, const char *host)
77 {
78 	struct ether_addr macaddr;
79 
80 	if (get_ether(host, &macaddr) == -1)
81 		return (-1);
82 
83 	return (send_wakeup(bpf, &macaddr));
84 }
85 
86 static int
87 bind_if_to_bpf(char const *ifname, int bpf)
88 {
89 	struct ifreq ifr;
90 	u_int dlt;
91 
92 	if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
93 	    sizeof(ifr.ifr_name))
94 		return (-1);
95 
96 	if (ioctl(bpf, BIOCSETIF, &ifr) == -1)
97 		return (-1);
98 
99 	if (ioctl(bpf, BIOCGDLT, &dlt) == -1)
100 		return (-1);
101 
102 	if (dlt != DLT_EN10MB)
103 		return (-1);
104 
105 	return (0);
106 }
107 
108 static int
109 find_ether(char *dst, size_t len)
110 {
111 	struct ifaddrs *ifap, *ifa;
112 	struct sockaddr_dl *sdl = NULL;
113 	int nifs;
114 
115 	if (dst == NULL || len == 0)
116 		return (0);
117 
118 	if (getifaddrs(&ifap) != 0)
119 		return (-1);
120 
121 	/* XXX also check the link state */
122 	for (nifs = 0, ifa = ifap; ifa; ifa = ifa->ifa_next)
123 		if (ifa->ifa_addr->sa_family == AF_LINK &&
124 		    ifa->ifa_flags & IFF_UP && ifa->ifa_flags & IFF_RUNNING) {
125 			sdl = (struct sockaddr_dl *)ifa->ifa_addr;
126 			if (sdl->sdl_type == IFT_ETHER) {
127 				strlcpy(dst, ifa->ifa_name, len);
128 				nifs++;
129 			}
130 		}
131 
132 	freeifaddrs(ifap);
133 	return (nifs == 1 ? 0 : -1);
134 }
135 
136 static int
137 get_ether(char const *text, struct ether_addr *addr)
138 {
139 	struct ether_addr *paddr;
140 
141 	paddr = ether_aton(text);
142 	if (paddr != NULL) {
143 		*addr = *paddr;
144 		return (0);
145 	}
146 	if (ether_hostton(text, addr)) {
147 		warnx("no match for host %s found", text);
148 		return (-1);
149 	}
150 	return (0);
151 }
152 
153 static int
154 send_wakeup(int bpf, struct ether_addr const *addr)
155 {
156 	struct {
157 		struct ether_header hdr;
158 		u_char data[SYNC_LEN + ETHER_ADDR_LEN * DESTADDR_COUNT];
159 	} __packed pkt;
160 	u_char *p;
161 	ssize_t bw;
162 	ssize_t len;
163 	int i;
164 
165 	(void)memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost));
166 	pkt.hdr.ether_type = htons(0);
167 	(void)memset(pkt.data, 0xff, SYNC_LEN);
168 	for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT;
169 	    p += ETHER_ADDR_LEN, i++)
170 		bcopy(addr->octet, p, ETHER_ADDR_LEN);
171 	p = (u_char *)&pkt;
172 	len = sizeof(pkt);
173 	bw = 0;
174 	while (len) {
175 		if ((bw = write(bpf, p, len)) == -1) {
176 			warn("write()");
177 			return (-1);
178 		}
179 		len -= bw;
180 		p += bw;
181 	}
182 	return (0);
183 }
184 
185 int
186 main(int argc, char *argv[])
187 {
188 	int bpf, n, rval;
189 	char ifname[IF_NAMESIZE];
190 
191 	if (argc < 2)
192 		usage();
193 
194 	if ((bpf = open(_PATH_BPF, O_RDWR)) == -1)
195 		err(1, "Cannot open bpf interface");
196 
197 	n = 2;
198 	if (bind_if_to_bpf(argv[1], bpf) == -1) {
199 		if (find_ether(ifname, sizeof(ifname)))
200 			err(1, "Failed to determine ethernet interface");
201 		if (bind_if_to_bpf(ifname, bpf) == -1)
202 			err(1, "Cannot bind to interface `%s'", ifname);
203 		--n;
204 	} else
205 		strlcpy(ifname, argv[1], sizeof(ifname));
206 
207 	if (n >= argc)
208 		usage();
209 	rval = 0;
210 	for (; n < argc; n++) {
211 		if (wake(bpf, argv[n]) != 0) {
212 			rval = 1;
213 			warn("Cannot send Wake on LAN frame over `%s' to `%s'",
214 			    ifname, argv[n]);
215 		}
216 	}
217 	exit(rval);
218 }
219