busybox/networking/ether-wake.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) puts("");
	}
	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 ether_wake_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 = getopt32(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;

		strncpy(if_hwaddr.ifr_name, ifname, sizeof(if_hwaddr.ifr_name));
		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]*/) {
		if (setsockopt_broadcast(s) < 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("cannot read 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;
}
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 tarball for details.
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
68	#include <netpacket/packet.h>
69	#include <net/ethernet.h>
70	#include <netinet/ether.h>
71	#include <linux/if.h>
72
73	#include "busybox.h"
74
75	/* Note: PF_INET, SOCK_DGRAM, IPPROTO_UDP would allow SIOCGIFHWADDR to
76	* work as non-root, but we need SOCK_PACKET to specify the Ethernet
77	* destination address.
78	*/
79	#ifdef PF_PACKET
80	# define whereto_t sockaddr_ll
81	# define make_socket() xsocket(PF_PACKET, SOCK_RAW, 0)
82	#else
83	# define whereto_t sockaddr
84	# define make_socket() xsocket(AF_INET, SOCK_PACKET, SOCK_PACKET)
85	#endif
86
87	#ifdef DEBUG
88	# define bb_debug_msg(fmt, args...) fprintf(stderr, fmt, ## args)
89	void bb_debug_dump_packet(unsigned char *outpack, int pktsize)
90	{
91	int i;
92	printf("packet dump:\n");
93	for (i = 0; i < pktsize; ++i) {
94	printf("%2.2x ", outpack[i]);
95	if (i % 20 == 19) puts("");
96	}
97	printf("\n\n");
98	}
99	#else
100	# define bb_debug_msg(fmt, args...)
101	# define bb_debug_dump_packet(outpack, pktsize)
102	#endif
103
104	static inline void get_dest_addr(const char arg, struct ether_addr eaddr);
105	static inline int get_fill(unsigned char pkt, struct ether_addr eaddr, int broadcast);
106	static inline int get_wol_pw(const char ethoptarg, unsigned char wol_passwd);
107
108	int ether_wake_main(int argc, char *argv[])
109	{
110	char ifname = "eth0", pass = NULL;
111	unsigned long flags;
112	unsigned char wol_passwd[6];
113	int wol_passwd_sz = 0;
114
115	int s; /* Raw socket */
116	int pktsize;
117	unsigned char outpack[1000];
118
119	struct ether_addr eaddr;
120	struct whereto_t whereto; /* who to wake up */
121
122	/* handle misc user options */
123	flags = getopt32(argc, argv, "bi:p:", &ifname, &pass);
124	if (optind == argc)
125	bb_show_usage();
126	if (pass)
127	wol_passwd_sz = get_wol_pw(pass, wol_passwd);
128
129	/* create the raw socket */
130	s = make_socket();
131
132	/* now that we have a raw socket we can drop root */
133	xsetuid(getuid());
134
135	/* look up the dest mac address */
136	get_dest_addr(argv[optind], &eaddr);
137
138	/* fill out the header of the packet */
139	pktsize = get_fill(outpack, &eaddr, flags /& 1 [OPT_BROADCAST]/);
140
141	bb_debug_dump_packet(outpack, pktsize);
142
143	/* Fill in the source address, if possible. */
144	#ifdef __linux__
145	{
146	struct ifreq if_hwaddr;
147
148	strncpy(if_hwaddr.ifr_name, ifname, sizeof(if_hwaddr.ifr_name));
149	if (ioctl(s, SIOCGIFHWADDR, &if_hwaddr) < 0)
150	bb_perror_msg_and_die("SIOCGIFHWADDR on %s failed", ifname);
151
152	memcpy(outpack+6, if_hwaddr.ifr_hwaddr.sa_data, 6);
153
154	# ifdef DEBUG
155	{
156	unsigned char *hwaddr = if_hwaddr.ifr_hwaddr.sa_data;
157	printf("The hardware address (SIOCGIFHWADDR) of %s is type %d "
158	"%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x\n\n", ifname,
159	if_hwaddr.ifr_hwaddr.sa_family, hwaddr[0], hwaddr[1],
160	hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]);
161	}
162	# endif
163	}
164	#endif /* __linux__ */
165
166	bb_debug_dump_packet(outpack, pktsize);
167
168	/* append the password if specified */
169	if (wol_passwd_sz > 0) {
170	memcpy(outpack+pktsize, wol_passwd, wol_passwd_sz);
171	pktsize += wol_passwd_sz;
172	}
173
174	bb_debug_dump_packet(outpack, pktsize);
175
176	/* This is necessary for broadcasts to work */
177	if (flags /& 1 [OPT_BROADCAST]/) {
178	if (setsockopt_broadcast(s) < 0)
179	bb_perror_msg("SO_BROADCAST");
180	}
181
182	#if defined(PF_PACKET)
183	{
184	struct ifreq ifr;
185	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
186	if (ioctl(s, SIOCGIFINDEX, &ifr) == -1)
187	bb_perror_msg_and_die("SIOCGIFINDEX");
188	memset(&whereto, 0, sizeof(whereto));
189	whereto.sll_family = AF_PACKET;
190	whereto.sll_ifindex = ifr.ifr_ifindex;
191	/* The manual page incorrectly claims the address must be filled.
192	We do so because the code may change to match the docs. */
193	whereto.sll_halen = ETH_ALEN;
194	memcpy(whereto.sll_addr, outpack, ETH_ALEN);
195	}
196	#else
197	whereto.sa_family = 0;
198	strcpy(whereto.sa_data, ifname);
199	#endif
200
201	if (sendto(s, outpack, pktsize, 0, (struct sockaddr *)&whereto, sizeof(whereto)) < 0)
202	bb_perror_msg(bb_msg_write_error);
203
204	close(s);
205
206	return EXIT_SUCCESS;
207	}
208
209	/* Convert the host ID string to a MAC address.
210	* The string may be a:
211	* Host name
212	* IP address string
213	* MAC address string
214	*/
215	static inline void get_dest_addr(const char hostid, struct ether_addr eaddr)
216	{
217	struct ether_addr *eap;
218
219	eap = ether_aton(hostid);
220	if (eap) {
221	eaddr = eap;
222	bb_debug_msg("The target station address is %s\n\n", ether_ntoa(eaddr));
223	#if !defined(__UCLIBC__)
224	} else if (ether_hostton(hostid, eaddr) == 0) {
225	bb_debug_msg("Station address for hostname %s is %s\n\n", hostid, ether_ntoa(eaddr));
226	#else
227	# warning Need to implement ether_hostton() for uClibc
228	#endif
229	} else
230	bb_show_usage();
231	}
232
233	static inline int get_fill(unsigned char pkt, struct ether_addr eaddr, int broadcast)
234	{
235	int offset, i;
236	unsigned char *station_addr = eaddr->ether_addr_octet;
237
238	if (broadcast)
239	memset(pkt+0, 0xff, 6);
240	else
241	memcpy(pkt, station_addr, 6);
242	memcpy(pkt+6, station_addr, 6);
243	pkt[12] = 0x08; /* Or 0x0806 for ARP, 0x8035 for RARP */
244	pkt[13] = 0x42;
245	offset = 14;
246
247	memset(pkt+offset, 0xff, 6);
248	offset += 6;
249
250	for (i = 0; i < 16; ++i) {
251	memcpy(pkt+offset, station_addr, 6);
252	offset += 6;
253	}
254
255	return offset;
256	}
257
258	static inline int get_wol_pw(const char ethoptarg, unsigned char wol_passwd)
259	{
260	int passwd[6];
261	int byte_cnt, i;
262
263	/* handle MAC format */
264	byte_cnt = sscanf(ethoptarg, "%2x:%2x:%2x:%2x:%2x:%2x",
265	&passwd[0], &passwd[1], &passwd[2],
266	&passwd[3], &passwd[4], &passwd[5]);
267	/* handle IP format */
268	if (byte_cnt < 4)
269	byte_cnt = sscanf(ethoptarg, "%d.%d.%d.%d",
270	&passwd[0], &passwd[1], &passwd[2], &passwd[3]);
271	if (byte_cnt < 4) {
272	bb_error_msg("cannot read Wake-On-LAN pass");
273	return 0;
274	}
275
276	for (i = 0; i < byte_cnt; ++i)
277	wol_passwd[i] = passwd[i];
278
279	bb_debug_msg("password: %2.2x %2.2x %2.2x %2.2x (%d)\n\n",
280	wol_passwd[0], wol_passwd[1], wol_passwd[2], wol_passwd[3],
281	byte_cnt);
282
283	return byte_cnt;
284	}