wake.c revision 203686
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: head/usr.sbin/wake/wake.c 203686 2010-02-08 20:57:49Z mbr $"); 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 58static int bind_if_to_bpf(char const *ifname, int bpf); 59static int find_ether(char *dst, size_t len); 60static int get_ether(char const *text, struct ether_addr *addr); 61static int send_wakeup(int bpf, struct ether_addr const *addr); 62static void usage(void); 63static int wake(int bpf, const char *host); 64 65static void 66usage(void) 67{ 68 69 (void)fprintf(stderr, "usage: wake [interface] lladdr [lladdr ...]\n"); 70 exit(1); 71} 72 73static int 74wake(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 84static int 85bind_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 106static int 107find_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 134static int 135get_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 151static int 152send_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 183int 184main(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