blob: d7d691772ecdbea5073a70ac4c57fe8622c6e715
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 | //config:config ETHER_WAKE |
67 | //config: bool "ether-wake" |
68 | //config: default y |
69 | //config: select PLATFORM_LINUX |
70 | //config: help |
71 | //config: Send a magic packet to wake up sleeping machines. |
72 | |
73 | //applet:IF_ETHER_WAKE(APPLET_ODDNAME(ether-wake, ether_wake, BB_DIR_USR_SBIN, BB_SUID_DROP, ether_wake)) |
74 | |
75 | //kbuild:lib-$(CONFIG_ETHER_WAKE) += ether-wake.o |
76 | |
77 | //usage:#define ether_wake_trivial_usage |
78 | //usage: "[-b] [-i IFACE] [-p aa:bb:cc:dd[:ee:ff]/a.b.c.d] MAC" |
79 | //usage:#define ether_wake_full_usage "\n\n" |
80 | //usage: "Send a magic packet to wake up sleeping machines.\n" |
81 | //usage: "MAC must be a station address (00:11:22:33:44:55) or\n" |
82 | //usage: "a hostname with a known 'ethers' entry.\n" |
83 | //usage: "\n -b Broadcast the packet" |
84 | //usage: "\n -i IFACE Interface to use (default eth0)" |
85 | //usage: "\n -p PASSWORD Append four or six byte PASSWORD to the packet" |
86 | |
87 | #include "libbb.h" |
88 | #include <netpacket/packet.h> |
89 | #include <netinet/ether.h> |
90 | #include <linux/if.h> |
91 | |
92 | /* Note: PF_INET, SOCK_DGRAM, IPPROTO_UDP would allow SIOCGIFHWADDR to |
93 | * work as non-root, but we need SOCK_PACKET to specify the Ethernet |
94 | * destination address. |
95 | */ |
96 | #ifdef PF_PACKET |
97 | # define whereto_t sockaddr_ll |
98 | # define make_socket() xsocket(PF_PACKET, SOCK_RAW, 0) |
99 | #else |
100 | # define whereto_t sockaddr |
101 | # define make_socket() xsocket(AF_INET, SOCK_PACKET, SOCK_PACKET) |
102 | #endif |
103 | |
104 | #ifdef DEBUG |
105 | # define bb_debug_msg(fmt, args...) fprintf(stderr, fmt, ## args) |
106 | void bb_debug_dump_packet(unsigned char *outpack, int pktsize) |
107 | { |
108 | int i; |
109 | printf("packet dump:\n"); |
110 | for (i = 0; i < pktsize; ++i) { |
111 | printf("%2.2x ", outpack[i]); |
112 | if (i % 20 == 19) bb_putchar('\n'); |
113 | } |
114 | printf("\n\n"); |
115 | } |
116 | #else |
117 | # define bb_debug_msg(fmt, args...) ((void)0) |
118 | # define bb_debug_dump_packet(outpack, pktsize) ((void)0) |
119 | #endif |
120 | |
121 | /* Convert the host ID string to a MAC address. |
122 | * The string may be a: |
123 | * Host name |
124 | * IP address string |
125 | * MAC address string |
126 | */ |
127 | static void get_dest_addr(const char *hostid, struct ether_addr *eaddr) |
128 | { |
129 | struct ether_addr *eap; |
130 | |
131 | eap = ether_aton_r(hostid, eaddr); |
132 | if (eap) { |
133 | bb_debug_msg("The target station address is %s\n\n", ether_ntoa(eap)); |
134 | #if !defined(__UCLIBC__) || UCLIBC_VERSION >= KERNEL_VERSION(0, 9, 30) |
135 | } else if (ether_hostton(hostid, eaddr) == 0) { |
136 | bb_debug_msg("Station address for hostname %s is %s\n\n", hostid, ether_ntoa(eaddr)); |
137 | #endif |
138 | } else { |
139 | bb_show_usage(); |
140 | } |
141 | } |
142 | |
143 | #define PKT_HEADER_SIZE (20 + 16*6) |
144 | static int fill_pkt_header(unsigned char *pkt, struct ether_addr *eaddr, int broadcast) |
145 | { |
146 | int i; |
147 | unsigned char *station_addr = eaddr->ether_addr_octet; |
148 | |
149 | memset(pkt, 0xff, 6); |
150 | if (!broadcast) |
151 | memcpy(pkt, station_addr, 6); |
152 | pkt += 6; |
153 | |
154 | memcpy(pkt, station_addr, 6); /* 6 */ |
155 | pkt += 6; |
156 | |
157 | *pkt++ = 0x08; /* 12 */ /* Or 0x0806 for ARP, 0x8035 for RARP */ |
158 | *pkt++ = 0x42; /* 13 */ |
159 | |
160 | memset(pkt, 0xff, 6); /* 14 */ |
161 | |
162 | for (i = 0; i < 16; ++i) { |
163 | pkt += 6; |
164 | memcpy(pkt, station_addr, 6); /* 20,26,32,... */ |
165 | } |
166 | |
167 | return PKT_HEADER_SIZE; /* length of packet */ |
168 | } |
169 | |
170 | static int get_wol_pw(const char *ethoptarg, unsigned char *wol_passwd) |
171 | { |
172 | unsigned passwd[6]; |
173 | int byte_cnt, i; |
174 | |
175 | /* handle MAC format */ |
176 | byte_cnt = sscanf(ethoptarg, "%2x:%2x:%2x:%2x:%2x:%2x", |
177 | &passwd[0], &passwd[1], &passwd[2], |
178 | &passwd[3], &passwd[4], &passwd[5]); |
179 | /* handle IP format */ |
180 | // FIXME: why < 4?? should it be < 6? |
181 | if (byte_cnt < 4) |
182 | byte_cnt = sscanf(ethoptarg, "%u.%u.%u.%u", |
183 | &passwd[0], &passwd[1], &passwd[2], &passwd[3]); |
184 | if (byte_cnt < 4) { |
185 | bb_error_msg("can't read Wake-On-LAN pass"); |
186 | return 0; |
187 | } |
188 | // TODO: check invalid numbers >255?? |
189 | for (i = 0; i < byte_cnt; ++i) |
190 | wol_passwd[i] = passwd[i]; |
191 | |
192 | bb_debug_msg("password: %2.2x %2.2x %2.2x %2.2x (%d)\n\n", |
193 | wol_passwd[0], wol_passwd[1], wol_passwd[2], wol_passwd[3], |
194 | byte_cnt); |
195 | |
196 | return byte_cnt; |
197 | } |
198 | |
199 | int ether_wake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
200 | int ether_wake_main(int argc UNUSED_PARAM, char **argv) |
201 | { |
202 | const char *ifname = "eth0"; |
203 | char *pass; |
204 | unsigned flags; |
205 | unsigned char wol_passwd[6]; |
206 | int wol_passwd_sz = 0; |
207 | int s; /* Raw socket */ |
208 | int pktsize; |
209 | unsigned char outpack[PKT_HEADER_SIZE + 6 /* max passwd size */ + 16 /* paranoia */]; |
210 | |
211 | struct ether_addr eaddr; |
212 | struct whereto_t whereto; /* who to wake up */ |
213 | |
214 | /* handle misc user options */ |
215 | opt_complementary = "=1"; |
216 | flags = getopt32(argv, "bi:p:", &ifname, &pass); |
217 | if (flags & 4) /* -p */ |
218 | wol_passwd_sz = get_wol_pw(pass, wol_passwd); |
219 | flags &= 1; /* we further interested only in -b [bcast] flag */ |
220 | |
221 | /* create the raw socket */ |
222 | s = make_socket(); |
223 | |
224 | /* now that we have a raw socket we can drop root */ |
225 | /* xsetuid(getuid()); - but save on code size... */ |
226 | |
227 | /* look up the dest mac address */ |
228 | get_dest_addr(argv[optind], &eaddr); |
229 | |
230 | /* fill out the header of the packet */ |
231 | pktsize = fill_pkt_header(outpack, &eaddr, flags /* & 1 OPT_BROADCAST */); |
232 | |
233 | bb_debug_dump_packet(outpack, pktsize); |
234 | |
235 | /* Fill in the source address, if possible. */ |
236 | #ifdef __linux__ |
237 | { |
238 | struct ifreq if_hwaddr; |
239 | |
240 | strncpy_IFNAMSIZ(if_hwaddr.ifr_name, ifname); |
241 | ioctl_or_perror_and_die(s, SIOCGIFHWADDR, &if_hwaddr, "SIOCGIFHWADDR on %s failed", ifname); |
242 | |
243 | memcpy(outpack+6, if_hwaddr.ifr_hwaddr.sa_data, 6); |
244 | |
245 | # ifdef DEBUG |
246 | { |
247 | unsigned char *hwaddr = if_hwaddr.ifr_hwaddr.sa_data; |
248 | printf("The hardware address (SIOCGIFHWADDR) of %s is type %d " |
249 | "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x\n\n", ifname, |
250 | if_hwaddr.ifr_hwaddr.sa_family, hwaddr[0], hwaddr[1], |
251 | hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]); |
252 | } |
253 | # endif |
254 | } |
255 | #endif /* __linux__ */ |
256 | |
257 | bb_debug_dump_packet(outpack, pktsize); |
258 | |
259 | /* append the password if specified */ |
260 | if (wol_passwd_sz > 0) { |
261 | memcpy(outpack+pktsize, wol_passwd, wol_passwd_sz); |
262 | pktsize += wol_passwd_sz; |
263 | } |
264 | |
265 | bb_debug_dump_packet(outpack, pktsize); |
266 | |
267 | /* This is necessary for broadcasts to work */ |
268 | if (flags /* & 1 OPT_BROADCAST */) { |
269 | if (setsockopt_broadcast(s) != 0) |
270 | bb_perror_msg("SO_BROADCAST"); |
271 | } |
272 | |
273 | #if defined(PF_PACKET) |
274 | { |
275 | struct ifreq ifr; |
276 | strncpy_IFNAMSIZ(ifr.ifr_name, ifname); |
277 | xioctl(s, SIOCGIFINDEX, &ifr); |
278 | memset(&whereto, 0, sizeof(whereto)); |
279 | whereto.sll_family = AF_PACKET; |
280 | whereto.sll_ifindex = ifr.ifr_ifindex; |
281 | /* The manual page incorrectly claims the address must be filled. |
282 | We do so because the code may change to match the docs. */ |
283 | whereto.sll_halen = ETH_ALEN; |
284 | memcpy(whereto.sll_addr, outpack, ETH_ALEN); |
285 | } |
286 | #else |
287 | whereto.sa_family = 0; |
288 | strcpy(whereto.sa_data, ifname); |
289 | #endif |
290 | xsendto(s, outpack, pktsize, (struct sockaddr *)&whereto, sizeof(whereto)); |
291 | if (ENABLE_FEATURE_CLEAN_UP) |
292 | close(s); |
293 | return EXIT_SUCCESS; |
294 | } |
295 |