1 /* $NetBSD: wakeonlan.c,v 1.2 2012/12/15 04:40:33 jakllsch Exp $ */ 2 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 /* Send Wake on LAN packets to hosts on a local Ethernet network */ 30 31 #include <sys/types.h> 32 #include <sys/param.h> 33 #include <sys/queue.h> 34 #include <sys/ioctl.h> 35 #include <sys/socket.h> 36 #include <sys/time.h> 37 38 #include <net/bpf.h> 39 #include <net/if.h> 40 #include <net/if_dl.h> 41 #include <net/if_types.h> 42 43 #include <netinet/in.h> 44 #include <netinet/if_ether.h> 45 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <ifaddrs.h> 50 #include <limits.h> 51 #include <paths.h> 52 #include <stdarg.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <sysexits.h> 57 #include <unistd.h> 58 59 #ifndef SYNC_LEN 60 #define SYNC_LEN 6 61 #endif 62 63 #ifndef DESTADDR_COUNT 64 #define DESTADDR_COUNT 16 65 #endif 66 67 __dead static void usage(void); 68 static int wake(int, const char *); 69 static int bind_if_to_bpf(char const *, int); 70 static int find_ether(char *, size_t); 71 static int get_ether(char const *, struct ether_addr *); 72 static int send_wakeup(int, struct ether_addr const *); 73 74 static void 75 usage(void) 76 { 77 fprintf(stderr, "usage: %s [interface] lladdr [lladdr ...]\n", 78 getprogname()); 79 exit(EXIT_FAILURE); 80 } 81 82 static int 83 wake(int bpf, const char *host) 84 { 85 struct ether_addr macaddr; 86 87 if (get_ether(host, &macaddr) == -1) 88 return -1; 89 90 return send_wakeup(bpf, &macaddr); 91 } 92 93 static int 94 bind_if_to_bpf(char const *ifname, int bpf) 95 { 96 struct ifreq ifr; 97 u_int dlt; 98 99 if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >= 100 sizeof(ifr.ifr_name)) { 101 errno = ENAMETOOLONG; 102 return -1; 103 } 104 if (ioctl(bpf, BIOCSETIF, &ifr) == -1) 105 return -1; 106 if (ioctl(bpf, BIOCGDLT, &dlt) == -1) 107 return -1; 108 if (dlt != DLT_EN10MB) { 109 errno = EOPNOTSUPP; 110 return -1; 111 } 112 return 0; 113 } 114 115 static int 116 find_ether(char *dst, size_t len) 117 { 118 struct ifaddrs *ifap, *ifa; 119 struct sockaddr_dl *sdl = NULL; 120 int nifs; 121 122 if (dst == NULL || len == 0) 123 return 0; 124 125 if (getifaddrs(&ifap) != 0) 126 return -1; 127 128 /* XXX also check the link state */ 129 for (nifs = 0, ifa = ifap; ifa; ifa = ifa->ifa_next) 130 if (ifa->ifa_addr->sa_family == AF_LINK && 131 ifa->ifa_flags & IFF_UP && ifa->ifa_flags & IFF_RUNNING) { 132 sdl = (struct sockaddr_dl *)ifa->ifa_addr; 133 if (sdl->sdl_type == IFT_ETHER) { 134 strlcpy(dst, ifa->ifa_name, len); 135 nifs++; 136 } 137 } 138 139 freeifaddrs(ifap); 140 return nifs == 1 ? 0 : -1; 141 } 142 143 static int 144 get_ether(char const *text, struct ether_addr *addr) 145 { 146 struct ether_addr *paddr; 147 148 paddr = ether_aton(text); 149 if (paddr != NULL) { 150 *addr = *paddr; 151 return 0; 152 } 153 if (ether_hostton(text, addr)) 154 return -1; 155 return 0; 156 } 157 158 static int 159 send_wakeup(int bpf, struct ether_addr const *addr) 160 { 161 struct { 162 struct ether_header hdr; 163 u_char data[SYNC_LEN + ETHER_ADDR_LEN * DESTADDR_COUNT]; 164 } pkt; 165 u_char *p; 166 int i; 167 ssize_t bw, len; 168 169 memset(pkt.hdr.ether_dhost, 0xff, sizeof(pkt.hdr.ether_dhost)); 170 memset(pkt.hdr.ether_shost, 0x00, sizeof(pkt.hdr.ether_shost)); 171 pkt.hdr.ether_type = htons(0); 172 memset(pkt.data, 0xff, SYNC_LEN); 173 for (p = pkt.data + SYNC_LEN, i = 0; i < DESTADDR_COUNT; 174 p += ETHER_ADDR_LEN, i++) 175 memcpy(p, addr->ether_addr_octet, ETHER_ADDR_LEN); 176 p = (u_char *)(void *)&pkt; 177 len = sizeof(pkt); 178 bw = 0; 179 while (len) { 180 if ((bw = write(bpf, p, len)) == -1) 181 return -1; 182 len -= bw; 183 p += bw; 184 } 185 return 0; 186 } 187 188 int 189 main(int argc, char *argv[]) 190 { 191 int bpf, n; 192 char ifname[IF_NAMESIZE]; 193 194 if (argc < 2) 195 usage(); 196 197 if ((bpf = open(_PATH_BPF, O_RDWR)) == -1) 198 err(EXIT_FAILURE, "Cannot open bpf interface"); 199 200 n = 2; 201 if (bind_if_to_bpf(argv[1], bpf) == -1) { 202 if (find_ether(ifname, sizeof(ifname))) 203 err(EXIT_FAILURE, "Failed to determine ethernet " 204 "interface"); 205 if (bind_if_to_bpf(ifname, bpf) == -1) 206 err(EXIT_FAILURE, "Cannot bind to interface `%s'", 207 ifname); 208 --n; 209 } else 210 strlcpy(ifname, argv[1], sizeof(ifname)); 211 212 if (n >= argc) 213 usage(); 214 for (; n < argc; n++) 215 if (wake(bpf, argv[n])) 216 warn("Cannot send Wake on LAN frame over `%s' to `%s'", 217 ifname, argv[n]); 218 return EXIT_SUCCESS; 219 } 220