busybox/networking/ether-wake.c
Rob Landley d921b2ecc0 Remove bb_ prefixes from xfuncs.c (and a few other places), consolidate
things like xasprintf() into xfuncs.c, remove xprint_file_by_name() (it only
had one user), clean up lots of #includes...  General cleanup pass.  What I've
been doing for the last couple days.

And it conflicts!  I've removed httpd.c from this checkin due to somebody else
touching that file.  It builds for me.  I have to catch a bus.  (Now you know
why I'm looking forward to Mercurial.)
2006-08-03 15:41:12 +00:00

286 lines
8.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* ether-wake.c - Send a magic packet to wake up sleeping machines.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* Author: Donald Becker, http://www.scyld.com/"; http://www.scyld.com/wakeonlan.html
* Busybox port: Christian Volkmann <haveaniceday@online.de>
* Used version of ether-wake.c: v1.09 11/12/2003 Donald Becker, http://www.scyld.com/";
*/
/* full usage according Donald Becker
* usage: ether-wake [-i <ifname>] [-p aa:bb:cc:dd[:ee:ff]] 00:11:22:33:44:55\n"
*
* This program generates and transmits a Wake-On-LAN (WOL)\n"
* \"Magic Packet\", used for restarting machines that have been\n"
* soft-powered-down (ACPI D3-warm state).\n"
* It currently generates the standard AMD Magic Packet format, with\n"
* an optional password appended.\n"
*
* The single required parameter is the Ethernet MAC (station) address\n"
* of the machine to wake or a host ID with known NSS 'ethers' entry.\n"
* The MAC address may be found with the 'arp' program while the target\n"
* machine is awake.\n"
*
* Options:\n"
* -b Send wake-up packet to the broadcast address.\n"
* -D Increase the debug level.\n"
* -i ifname Use interface IFNAME instead of the default 'eth0'.\n"
* -p <pw> Append the four or six byte password PW to the packet.\n"
* A password is only required for a few adapter types.\n"
* The password may be specified in ethernet hex format\n"
* or dotted decimal (Internet address)\n"
* -p 00:22:44:66:88:aa\n"
* -p 192.168.1.1\n";
*
*
* This program generates and transmits a Wake-On-LAN (WOL) "Magic Packet",
* used for restarting machines that have been soft-powered-down
* (ACPI D3-warm state). It currently generates the standard AMD Magic Packet
* format, with an optional password appended.
*
* This software may be used and distributed according to the terms
* of the GNU Public License, incorporated herein by reference.
* Contact the author for use under other terms.
*
* This source file was originally part of the network tricks package, and
* is now distributed to support the Scyld Beowulf system.
* Copyright 1999-2003 Donald Becker and Scyld Computing Corporation.
*
* The author may be reached as becker@scyld, or C/O
* Scyld Computing Corporation
* 914 Bay Ridge Road, Suite 220
* Annapolis MD 21403
*
* Notes:
* On some systems dropping root capability allows the process to be
* dumped, traced or debugged.
* If someone traces this program, they get control of a raw socket.
* Linux handles this safely, but beware when porting this program.
*
* An alternative to needing 'root' is using a UDP broadcast socket, however
* doing so only works with adapters configured for unicast+broadcast Rx
* filter. That configuration consumes more power.
*/
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <netinet/ether.h>
#include <linux/if.h>
#include "busybox.h"
/* Note: PF_INET, SOCK_DGRAM, IPPROTO_UDP would allow SIOCGIFHWADDR to
* work as non-root, but we need SOCK_PACKET to specify the Ethernet
* destination address.
*/
#ifdef PF_PACKET
# define whereto_t sockaddr_ll
# define make_socket() xsocket(PF_PACKET, SOCK_RAW, 0)
#else
# define whereto_t sockaddr
# define make_socket() xsocket(AF_INET, SOCK_PACKET, SOCK_PACKET)
#endif
#ifdef DEBUG
# define bb_debug_msg(fmt, args...) fprintf(stderr, fmt, ## args)
void bb_debug_dump_packet(unsigned char *outpack, int pktsize)
{
int i;
printf("packet dump:\n");
for (i = 0; i < pktsize; ++i) {
printf("%2.2x ", outpack[i]);
if (i % 20 == 19) printf("\n");
}
printf("\n\n");
}
#else
# define bb_debug_msg(fmt, args...)
# define bb_debug_dump_packet(outpack, pktsize)
#endif
static inline void get_dest_addr(const char *arg, struct ether_addr *eaddr);
static inline int get_fill(unsigned char *pkt, struct ether_addr *eaddr, int broadcast);
static inline int get_wol_pw(const char *ethoptarg, unsigned char *wol_passwd);
int etherwake_main(int argc, char *argv[])
{
char *ifname = "eth0", *pass = NULL;
unsigned long flags;
unsigned char wol_passwd[6];
int wol_passwd_sz = 0;
int s; /* Raw socket */
int pktsize;
unsigned char outpack[1000];
struct ether_addr eaddr;
struct whereto_t whereto; /* who to wake up */
/* handle misc user options */
flags = bb_getopt_ulflags(argc, argv, "bi:p:", &ifname, &pass);
if (optind == argc)
bb_show_usage();
if (pass)
wol_passwd_sz = get_wol_pw(pass, wol_passwd);
/* create the raw socket */
s = make_socket();
/* now that we have a raw socket we can drop root */
xsetuid(getuid());
/* look up the dest mac address */
get_dest_addr(argv[optind], &eaddr);
/* fill out the header of the packet */
pktsize = get_fill(outpack, &eaddr, flags /*& 1 [OPT_BROADCAST]*/);
bb_debug_dump_packet(outpack, pktsize);
/* Fill in the source address, if possible. */
#ifdef __linux__
{
struct ifreq if_hwaddr;
strcpy(if_hwaddr.ifr_name, ifname);
if (ioctl(s, SIOCGIFHWADDR, &if_hwaddr) < 0)
bb_perror_msg_and_die("SIOCGIFHWADDR on %s failed", ifname);
memcpy(outpack+6, if_hwaddr.ifr_hwaddr.sa_data, 6);
# ifdef DEBUG
{
unsigned char *hwaddr = if_hwaddr.ifr_hwaddr.sa_data;
printf("The hardware address (SIOCGIFHWADDR) of %s is type %d "
"%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x\n\n", ifname,
if_hwaddr.ifr_hwaddr.sa_family, hwaddr[0], hwaddr[1],
hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]);
}
# endif
}
#endif /* __linux__ */
bb_debug_dump_packet(outpack, pktsize);
/* append the password if specified */
if (wol_passwd_sz > 0) {
memcpy(outpack+pktsize, wol_passwd, wol_passwd_sz);
pktsize += wol_passwd_sz;
}
bb_debug_dump_packet(outpack, pktsize);
/* This is necessary for broadcasts to work */
if (flags /*& 1 [OPT_BROADCAST]*/) {
int one = 1;
if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (void *)&one, sizeof(one)) < 0)
bb_perror_msg("SO_BROADCAST");
}
#if defined(PF_PACKET)
{
struct ifreq ifr;
strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(s, SIOCGIFINDEX, &ifr) == -1)
bb_perror_msg_and_die("SIOCGIFINDEX");
memset(&whereto, 0, sizeof(whereto));
whereto.sll_family = AF_PACKET;
whereto.sll_ifindex = ifr.ifr_ifindex;
/* The manual page incorrectly claims the address must be filled.
We do so because the code may change to match the docs. */
whereto.sll_halen = ETH_ALEN;
memcpy(whereto.sll_addr, outpack, ETH_ALEN);
}
#else
whereto.sa_family = 0;
strcpy(whereto.sa_data, ifname);
#endif
if (sendto(s, outpack, pktsize, 0, (struct sockaddr *)&whereto, sizeof(whereto)) < 0)
bb_perror_msg(bb_msg_write_error);
close(s);
return EXIT_SUCCESS;
}
/* Convert the host ID string to a MAC address.
* The string may be a:
* Host name
* IP address string
* MAC address string
*/
static inline void get_dest_addr(const char *hostid, struct ether_addr *eaddr)
{
struct ether_addr *eap;
eap = ether_aton(hostid);
if (eap) {
*eaddr = *eap;
bb_debug_msg("The target station address is %s\n\n", ether_ntoa(eaddr));
#if !defined(__UCLIBC__)
} else if (ether_hostton(hostid, eaddr) == 0) {
bb_debug_msg("Station address for hostname %s is %s\n\n", hostid, ether_ntoa(eaddr));
#else
# warning Need to implement ether_hostton() for uClibc
#endif
} else
bb_show_usage();
}
static inline int get_fill(unsigned char *pkt, struct ether_addr *eaddr, int broadcast)
{
int offset, i;
unsigned char *station_addr = eaddr->ether_addr_octet;
if (broadcast)
memset(pkt+0, 0xff, 6);
else
memcpy(pkt, station_addr, 6);
memcpy(pkt+6, station_addr, 6);
pkt[12] = 0x08; /* Or 0x0806 for ARP, 0x8035 for RARP */
pkt[13] = 0x42;
offset = 14;
memset(pkt+offset, 0xff, 6);
offset += 6;
for (i = 0; i < 16; ++i) {
memcpy(pkt+offset, station_addr, 6);
offset += 6;
}
return offset;
}
static inline int get_wol_pw(const char *ethoptarg, unsigned char *wol_passwd)
{
int passwd[6];
int byte_cnt, i;
/* handle MAC format */
byte_cnt = sscanf(ethoptarg, "%2x:%2x:%2x:%2x:%2x:%2x",
&passwd[0], &passwd[1], &passwd[2],
&passwd[3], &passwd[4], &passwd[5]);
/* handle IP format */
if (byte_cnt < 4)
byte_cnt = sscanf(ethoptarg, "%d.%d.%d.%d",
&passwd[0], &passwd[1], &passwd[2], &passwd[3]);
if (byte_cnt < 4) {
bb_error_msg("Unable to read the Wake-On-LAN pass");
return 0;
}
for (i = 0; i < byte_cnt; ++i)
wol_passwd[i] = passwd[i];
bb_debug_msg("password: %2.2x %2.2x %2.2x %2.2x (%d)\n\n",
wol_passwd[0], wol_passwd[1], wol_passwd[2], wol_passwd[3],
byte_cnt);
return byte_cnt;
}