release/src/router/busybox/networking/ether-wake.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ether-wake.c - Send a magic packet to wake up sleeping machines.
   4  *
   5  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   6  *
   7  * Author:      Donald Becker, http://www.scyld.com/"; http://www.scyld.com/wakeonlan.html
   8  * Busybox port: Christian Volkmann <haveaniceday@online.de>
   9  *               Used version of ether-wake.c: v1.09 11/12/2003 Donald Becker, http://www.scyld.com/";
  10  */
  11
  12 /* full usage according Donald Becker
  13  * usage: ether-wake [-i <ifname>] [-p aa:bb:cc:dd[:ee:ff]] 00:11:22:33:44:55\n"
  14  *
  15  *      This program generates and transmits a Wake-On-LAN (WOL)\n"
  16  *      \"Magic Packet\", used for restarting machines that have been\n"
  17  *      soft-powered-down (ACPI D3-warm state).\n"
  18  *      It currently generates the standard AMD Magic Packet format, with\n"
  19  *      an optional password appended.\n"
  20  *
  21  *      The single required parameter is the Ethernet MAC (station) address\n"
  22  *      of the machine to wake or a host ID with known NSS 'ethers' entry.\n"
  23  *      The MAC address may be found with the 'arp' program while the target\n"
  24  *      machine is awake.\n"
  25  *
  26  *      Options:\n"
  27  *              -b      Send wake-up packet to the broadcast address.\n"
  28  *              -D      Increase the debug level.\n"
  29  *              -i ifname       Use interface IFNAME instead of the default 'eth0'.\n"
  30  *              -p <pw>         Append the four or six byte password PW to the packet.\n"
  31  *                                      A password is only required for a few adapter types.\n"
  32  *                                      The password may be specified in ethernet hex format\n"
  33  *                                      or dotted decimal (Internet address)\n"
  34  *              -p 00:22:44:66:88:aa\n"
  35  *              -p 192.168.1.1\n";
  36  *
  37  *
  38  *      This program generates and transmits a Wake-On-LAN (WOL) "Magic Packet",
  39  *      used for restarting machines that have been soft-powered-down
  40  *      (ACPI D3-warm state).  It currently generates the standard AMD Magic Packet
  41  *      format, with an optional password appended.
  42  *
  43  *      This software may be used and distributed according to the terms
  44  *      of the GNU Public License, incorporated herein by reference.
  45  *      Contact the author for use under other terms.
  46  *
  47  *      This source file was originally part of the network tricks package, and
  48  *      is now distributed to support the Scyld Beowulf system.
  49  *      Copyright 1999-2003 Donald Becker and Scyld Computing Corporation.
  50  *
  51  *      The author may be reached as becker@scyld, or C/O
  52  *       Scyld Computing Corporation
  53  *       914 Bay Ridge Road, Suite 220
  54  *       Annapolis MD 21403
  55  *
  56  *   Notes:
  57  *   On some systems dropping root capability allows the process to be
  58  *   dumped, traced or debugged.
  59  *   If someone traces this program, they get control of a raw socket.
  60  *   Linux handles this safely, but beware when porting this program.
  61  *
  62  *   An alternative to needing 'root' is using a UDP broadcast socket, however
  63  *   doing so only works with adapters configured for unicast+broadcast Rx
  64  *   filter.  That configuration consumes more power.
  65 */
  66
  67 //usage:#define ether_wake_trivial_usage
  68 //usage:       "[-b] [-i iface] [-p aa:bb:cc:dd[:ee:ff]] MAC"
  69 //usage:#define ether_wake_full_usage "\n\n"
  70 //usage:       "Send a magic packet to wake up sleeping machines.\n"
  71 //usage:       "MAC must be a station address (00:11:22:33:44:55) or\n"
  72 //usage:       "a hostname with a known 'ethers' entry.\n"
  73 //usage:     "\n        -b              Send wake-up packet to the broadcast address"
  74 //usage:     "\n        -i iface        Interface to use (default eth0)"
  75 //usage:     "\n        -p pass         Append four or six byte password PW to the packet"
  76
  77 #include "libbb.h"
  78 #include <netpacket/packet.h>
  79 #include <netinet/ether.h>
  80 #include <linux/if.h>
  81
  82 /* Note: PF_INET, SOCK_DGRAM, IPPROTO_UDP would allow SIOCGIFHWADDR to
  83  * work as non-root, but we need SOCK_PACKET to specify the Ethernet
  84  * destination address.
  85  */
  86 #ifdef PF_PACKET
  87 # define whereto_t sockaddr_ll
  88 # define make_socket() xsocket(PF_PACKET, SOCK_RAW, 0)
  89 #else
  90 # define whereto_t sockaddr
  91 # define make_socket() xsocket(AF_INET, SOCK_PACKET, SOCK_PACKET)
  92 #endif
  93
  94 #ifdef DEBUG
  95 # define bb_debug_msg(fmt, args...) fprintf(stderr, fmt, ## args)
  96 void bb_debug_dump_packet(unsigned char *outpack, int pktsize)
  97 {
  98         int i;
  99         printf("packet dump:\n");
 100         for (i = 0; i < pktsize; ++i) {
 101                 printf("%2.2x ", outpack[i]);
 102                 if (i % 20 == 19) bb_putchar('\n');
 103         }
 104         printf("\n\n");
 105 }
 106 #else
 107 # define bb_debug_msg(fmt, args...)             ((void)0)
 108 # define bb_debug_dump_packet(outpack, pktsize) ((void)0)
 109 #endif
 110
 111 /* Convert the host ID string to a MAC address.
 112  * The string may be a:
 113  *    Host name
 114  *    IP address string
 115  *    MAC address string
 116 */
 117 static void get_dest_addr(const char *hostid, struct ether_addr *eaddr)
 118 {
 119         struct ether_addr *eap;
 120
 121         eap = ether_aton_r(hostid, eaddr);
 122         if (eap) {
 123                 bb_debug_msg("The target station address is %s\n\n", ether_ntoa(eap));
 124 #if !defined(__UCLIBC_MAJOR__) \
 125  || __UCLIBC_MAJOR__ > 0 \
 126  || __UCLIBC_MINOR__ > 9 \
 127  || (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ >= 30)
 128         } else if (ether_hostton(hostid, eaddr) == 0) {
 129                 bb_debug_msg("Station address for hostname %s is %s\n\n", hostid, ether_ntoa(eaddr));
 130 #endif
 131         } else {
 132                 bb_show_usage();
 133         }
 134 }
 135
 136 static int get_fill(unsigned char *pkt, struct ether_addr *eaddr, int broadcast)
 137 {
 138         int i;
 139         unsigned char *station_addr = eaddr->ether_addr_octet;
 140
 141         memset(pkt, 0xff, 6);
 142         if (!broadcast)
 143                 memcpy(pkt, station_addr, 6);
 144         pkt += 6;
 145
 146         memcpy(pkt, station_addr, 6); /* 6 */
 147         pkt += 6;
 148
 149         *pkt++ = 0x08; /* 12 */ /* Or 0x0806 for ARP, 0x8035 for RARP */
 150         *pkt++ = 0x42; /* 13 */
 151
 152         memset(pkt, 0xff, 6); /* 14 */
 153
 154         for (i = 0; i < 16; ++i) {
 155                 pkt += 6;
 156                 memcpy(pkt, station_addr, 6); /* 20,26,32,... */
 157         }
 158
 159         return 20 + 16*6; /* length of packet */
 160 }
 161
 162 static int get_wol_pw(const char *ethoptarg, unsigned char *wol_passwd)
 163 {
 164         unsigned passwd[6];
 165         int byte_cnt, i;
 166
 167         /* handle MAC format */
 168         byte_cnt = sscanf(ethoptarg, "%2x:%2x:%2x:%2x:%2x:%2x",
 169                           &passwd[0], &passwd[1], &passwd[2],
 170                           &passwd[3], &passwd[4], &passwd[5]);
 171         /* handle IP format */
 172 // FIXME: why < 4?? should it be < 6?
 173         if (byte_cnt < 4)
 174                 byte_cnt = sscanf(ethoptarg, "%u.%u.%u.%u",
 175                                   &passwd[0], &passwd[1], &passwd[2], &passwd[3]);
 176         if (byte_cnt < 4) {
 177                 bb_error_msg("can't read Wake-On-LAN pass");
 178                 return 0;
 179         }
 180 // TODO: check invalid numbers >255??
 181         for (i = 0; i < byte_cnt; ++i)
 182                 wol_passwd[i] = passwd[i];
 183
 184         bb_debug_msg("password: %2.2x %2.2x %2.2x %2.2x (%d)\n\n",
 185                      wol_passwd[0], wol_passwd[1], wol_passwd[2], wol_passwd[3],
 186                      byte_cnt);
 187
 188         return byte_cnt;
 189 }
 190
 191 int ether_wake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 192 int ether_wake_main(int argc UNUSED_PARAM, char **argv)
 193 {
 194         const char *ifname = "eth0";
 195         char *pass;
 196         unsigned flags;
 197         unsigned char wol_passwd[6];
 198         int wol_passwd_sz = 0;
 199         int s;  /* Raw socket */
 200         int pktsize;
 201         unsigned char outpack[1000];
 202
 203         struct ether_addr eaddr;
 204         struct whereto_t whereto;  /* who to wake up */
 205
 206         /* handle misc user options */
 207         opt_complementary = "=1";
 208         flags = getopt32(argv, "bi:p:", &ifname, &pass);
 209         if (flags & 4) /* -p */
 210                 wol_passwd_sz = get_wol_pw(pass, wol_passwd);
 211         flags &= 1; /* we further interested only in -b [bcast] flag */
 212
 213         /* create the raw socket */
 214         s = make_socket();
 215
 216         /* now that we have a raw socket we can drop root */
 217         /* xsetuid(getuid()); - but save on code size... */
 218
 219         /* look up the dest mac address */
 220         get_dest_addr(argv[optind], &eaddr);
 221
 222         /* fill out the header of the packet */
 223         pktsize = get_fill(outpack, &eaddr, flags /* & 1 OPT_BROADCAST */);
 224
 225         bb_debug_dump_packet(outpack, pktsize);
 226
 227         /* Fill in the source address, if possible. */
 228 #ifdef __linux__
 229         {
 230                 struct ifreq if_hwaddr;
 231
 232                 strncpy_IFNAMSIZ(if_hwaddr.ifr_name, ifname);
 233                 ioctl_or_perror_and_die(s, SIOCGIFHWADDR, &if_hwaddr, "SIOCGIFHWADDR on %s failed", ifname);
 234
 235                 memcpy(outpack+6, if_hwaddr.ifr_hwaddr.sa_data, 6);
 236
 237 # ifdef DEBUG
 238                 {
 239                         unsigned char *hwaddr = if_hwaddr.ifr_hwaddr.sa_data;
 240                         printf("The hardware address (SIOCGIFHWADDR) of %s is type %d  "
 241                                    "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x\n\n", ifname,
 242                                    if_hwaddr.ifr_hwaddr.sa_family, hwaddr[0], hwaddr[1],
 243                                    hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]);
 244                 }
 245 # endif
 246         }
 247 #endif /* __linux__ */
 248
 249         bb_debug_dump_packet(outpack, pktsize);
 250
 251         /* append the password if specified */
 252         if (wol_passwd_sz > 0) {
 253                 memcpy(outpack+pktsize, wol_passwd, wol_passwd_sz);
 254                 pktsize += wol_passwd_sz;
 255         }
 256
 257         bb_debug_dump_packet(outpack, pktsize);
 258
 259         /* This is necessary for broadcasts to work */
 260         if (flags /* & 1 OPT_BROADCAST */) {
 261                 if (setsockopt_broadcast(s) != 0)
 262                         bb_perror_msg("SO_BROADCAST");
 263         }
 264
 265 #if defined(PF_PACKET)
 266         {
 267                 struct ifreq ifr;
 268                 strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
 269                 xioctl(s, SIOCGIFINDEX, &ifr);
 270                 memset(&whereto, 0, sizeof(whereto));
 271                 whereto.sll_family = AF_PACKET;
 272                 whereto.sll_ifindex = ifr.ifr_ifindex;
 273                 /* The manual page incorrectly claims the address must be filled.
 274                    We do so because the code may change to match the docs. */
 275                 whereto.sll_halen = ETH_ALEN;
 276                 memcpy(whereto.sll_addr, outpack, ETH_ALEN);
 277         }
 278 #else
 279         whereto.sa_family = 0;
 280         strcpy(whereto.sa_data, ifname);
 281 #endif
 282         xsendto(s, outpack, pktsize, (struct sockaddr *)&whereto, sizeof(whereto));
 283         if (ENABLE_FEATURE_CLEAN_UP)
 284                 close(s);
 285         return EXIT_SUCCESS;
 286 }