1 /* vi: set sw=4 ts=4: */
2 /*
3  * simple ACPI events listener
4  *
5  * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
6  *
7  * Licensed under GPLv2, see file LICENSE in this source tree.
8  */
9 //config:config ACPID
10 //config:	bool "acpid (9 kb)"
11 //config:	default y
12 //config:	help
13 //config:	acpid listens to ACPI events coming either in textual form from
14 //config:	/proc/acpi/event (though it is marked deprecated it is still widely
15 //config:	used and _is_ a standard) or in binary form from specified evdevs
16 //config:	(just use /dev/input/event*).
17 //config:
18 //config:	It parses the event to retrieve ACTION and a possible PARAMETER.
19 //config:	It then spawns /etc/acpi/<ACTION>[/<PARAMETER>] either via run-parts
20 //config:	(if the resulting path is a directory) or directly as an executable.
21 //config:
22 //config:	N.B. acpid relies on run-parts so have the latter installed.
23 //config:
24 //config:config FEATURE_ACPID_COMPAT
25 //config:	bool "Accept and ignore redundant options"
26 //config:	default y
27 //config:	depends on ACPID
28 //config:	help
29 //config:	Accept and ignore compatibility options -g -m -s -S -v.
30 
31 //applet:IF_ACPID(APPLET(acpid, BB_DIR_SBIN, BB_SUID_DROP))
32 
33 //kbuild:lib-$(CONFIG_ACPID) += acpid.o
34 
35 //usage:#define acpid_trivial_usage
36 //usage:       "[-df] [-c CONFDIR] [-l LOGFILE] [-a ACTIONFILE] [-M MAPFILE] [-e PROC_EVENT_FILE] [-p PIDFILE]"
37 //usage:#define acpid_full_usage "\n\n"
38 //usage:       "Listen to ACPI events and spawn specific helpers on event arrival\n"
39 //usage:     "\n	-d	Log to stderr, not log file (implies -f)"
40 //usage:     "\n	-f	Run in foreground"
41 //usage:     "\n	-c DIR	Config directory [/etc/acpi]"
42 //usage:     "\n	-e FILE	/proc event file [/proc/acpi/event]"
43 //usage:     "\n	-l FILE	Log file [/var/log/acpid.log]"
44 //usage:	IF_FEATURE_PIDFILE(
45 //usage:     "\n	-p FILE	Pid file [" CONFIG_PID_FILE_PATH "/acpid.pid]"
46 //usage:	)
47 //usage:     "\n	-a FILE	Action file [/etc/acpid.conf]"
48 //usage:     "\n	-M FILE Map file [/etc/acpi.map]"
49 //usage:	IF_FEATURE_ACPID_COMPAT(
50 //usage:     "\n\nAccept and ignore compatibility options -g -m -s -S -v"
51 //usage:	)
52 //usage:
53 //usage:#define acpid_example_usage
54 //usage:       "Without -e option, acpid uses all /dev/input/event* files\n"
55 //usage:       "# acpid\n"
56 //usage:       "# acpid -l /var/log/my-acpi-log\n"
57 //usage:       "# acpid -e /proc/acpi/event\n"
58 
59 #include "libbb.h"
60 #include <syslog.h>
61 #include <linux/input.h>
62 
63 #ifndef EV_SW
64 # define EV_SW         0x05
65 #endif
66 #ifndef EV_KEY
67 # define EV_KEY        0x01
68 #endif
69 #ifndef SW_LID
70 # define SW_LID        0x00
71 #endif
72 #ifndef SW_RFKILL_ALL
73 # define SW_RFKILL_ALL 0x03
74 #endif
75 #ifndef KEY_POWER
76 # define KEY_POWER      116     /* SC System Power Down */
77 #endif
78 #ifndef KEY_SLEEP
79 # define KEY_SLEEP      142     /* SC System Sleep */
80 #endif
81 
82 enum {
83 	OPT_c = (1 << 0),
84 	OPT_d = (1 << 1),
85 	OPT_e = (1 << 2),
86 	OPT_f = (1 << 3),
87 	OPT_l = (1 << 4),
88 	OPT_a = (1 << 5),
89 	OPT_M = (1 << 6),
90 	OPT_p = (1 << 7) * ENABLE_FEATURE_PIDFILE,
91 };
92 
93 struct acpi_event {
94 	const char *s_type;
95 	uint16_t n_type;
96 	const char *s_code;
97 	uint16_t n_code;
98 	uint32_t value;
99 	const char *desc;
100 };
101 
102 static const struct acpi_event f_evt_tab[] ALIGN_PTR = {
103 	{ "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRF 00000080" },
104 	{ "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRB 00000080" },
105 	{ "EV_SW", 0x05, "SW_LID", 0x00, 1, "button/lid LID0 00000080" },
106 };
107 
108 struct acpi_action {
109 	const char *key;
110 	const char *action;
111 };
112 
113 static const struct acpi_action f_act_tab[] ALIGN_PTR = {
114 	{ "PWRF", "PWRF/00000080" },
115 	{ "LID0", "LID/00000080" },
116 };
117 
118 struct globals {
119 	struct acpi_action *act_tab;
120 	int n_act;
121 	struct acpi_event *evt_tab;
122 	int n_evt;
123 } FIX_ALIASING;
124 #define G (*ptr_to_globals)
125 #define act_tab         (G.act_tab)
126 #define n_act           (G.n_act  )
127 #define evt_tab         (G.evt_tab)
128 #define n_evt           (G.n_evt  )
129 #define INIT_G() do { \
130 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
131 } while (0)
132 
133 /*
134  * acpid listens to ACPI events coming either in textual form
135  * from /proc/acpi/event (though it is marked deprecated,
136  * it is still widely used and _is_ a standard) or in binary form
137  * from specified evdevs (just use /dev/input/event*).
138  * It parses the event to retrieve ACTION and a possible PARAMETER.
139  * It then spawns /etc/acpi/<ACTION>[/<PARAMETER>] either via run-parts
140  * (if the resulting path is a directory) or directly.
141  * If the resulting path does not exist it logs it via perror
142  * and continues listening.
143  */
144 
process_event(const char * event)145 static void process_event(const char *event)
146 {
147 	struct stat st;
148 	char *handler = xasprintf("./%s", event);
149 	const char *args[] = { "run-parts", handler, NULL };
150 
151 	// log the event
152 	bb_simple_error_msg(event);
153 
154 	// spawn handler
155 	// N.B. run-parts would require scripts to have #!/bin/sh
156 	// handler is directory? -> use run-parts
157 	// handler is file? -> run it directly
158 	if (0 == stat(event, &st))
159 		spawn((char **)args + (0==(st.st_mode & S_IFDIR)));
160 	else
161 		bb_simple_perror_msg(event);
162 
163 	free(handler);
164 }
165 
find_action(struct input_event * ev,const char * buf)166 static const char *find_action(struct input_event *ev, const char *buf)
167 {
168 	const char *action = NULL;
169 	int i;
170 
171 	// map event
172 	for (i = 0; i < n_evt; i++) {
173 		if (ev) {
174 			if (ev->type == evt_tab[i].n_type && ev->code == evt_tab[i].n_code && ev->value == evt_tab[i].value) {
175 				action = evt_tab[i].desc;
176 				break;
177 			}
178 		}
179 
180 		if (buf) {
181 			if (is_prefixed_with(evt_tab[i].desc, buf)) {
182 				action = evt_tab[i].desc;
183 				break;
184 			}
185 		}
186 	}
187 
188 	// get action
189 	if (action) {
190 		for (i = 0; i < n_act; i++) {
191 			if (strstr(action, act_tab[i].key)) {
192 				action = act_tab[i].action;
193 				break;
194 			}
195 		}
196 	}
197 
198 	return action;
199 }
200 
parse_conf_file(const char * filename)201 static void parse_conf_file(const char *filename)
202 {
203 	parser_t *parser;
204 	char *tokens[2];
205 
206 	parser = config_open2(filename, fopen_for_read);
207 
208 	if (parser) {
209 		while (config_read(parser, tokens, 2, 2, "# \t", PARSE_NORMAL)) {
210 			act_tab = xrealloc_vector(act_tab, 1, n_act);
211 			act_tab[n_act].key = xstrdup(tokens[0]);
212 			act_tab[n_act].action = xstrdup(tokens[1]);
213 			n_act++;
214 		}
215 		config_close(parser);
216 	} else {
217 		act_tab = (void*)f_act_tab;
218 		n_act = ARRAY_SIZE(f_act_tab);
219 	}
220 }
221 
parse_map_file(const char * filename)222 static void parse_map_file(const char *filename)
223 {
224 	parser_t *parser;
225 	char *tokens[6];
226 
227 	parser = config_open2(filename, fopen_for_read);
228 
229 	if (parser) {
230 		while (config_read(parser, tokens, 6, 6, "# \t", PARSE_NORMAL)) {
231 			evt_tab = xrealloc_vector(evt_tab, 1, n_evt);
232 			evt_tab[n_evt].s_type = xstrdup(tokens[0]);
233 			evt_tab[n_evt].n_type = xstrtou(tokens[1], 16);
234 			evt_tab[n_evt].s_code = xstrdup(tokens[2]);
235 			evt_tab[n_evt].n_code = xatou16(tokens[3]);
236 			evt_tab[n_evt].value = xatoi_positive(tokens[4]);
237 			evt_tab[n_evt].desc = xstrdup(tokens[5]);
238 			n_evt++;
239 		}
240 		config_close(parser);
241 	} else {
242 		evt_tab = (void*)f_evt_tab;
243 		n_evt = ARRAY_SIZE(f_evt_tab);
244 	}
245 }
246 
247 /*
248  * acpid [-c conf_dir] [-r conf_file ] [-a map_file ] [-l log_file] [-e proc_event_file]
249  */
250 
251 int acpid_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
acpid_main(int argc UNUSED_PARAM,char ** argv)252 int acpid_main(int argc UNUSED_PARAM, char **argv)
253 {
254 	int nfd;
255 	int opts;
256 	struct pollfd *pfd;
257 	const char *opt_dir = "/etc/acpi";
258 	const char *opt_input = "/dev/input/event";
259 	const char *opt_logfile = "/var/log/acpid.log";
260 	const char *opt_action = "/etc/acpid.conf";
261 	const char *opt_map = "/etc/acpi.map";
262 #if ENABLE_FEATURE_PIDFILE
263 	const char *opt_pidfile = CONFIG_PID_FILE_PATH "/acpid.pid";
264 #endif
265 
266 	INIT_G();
267 
268 	opts = getopt32(argv, "^"
269 		"c:de:fl:a:M:"
270 		IF_FEATURE_PIDFILE("p:")
271 		IF_FEATURE_ACPID_COMPAT("g:m:s:S:v")
272 		"\0"
273 		"df:e--e",
274 		&opt_dir, &opt_input, &opt_logfile, &opt_action, &opt_map
275 		IF_FEATURE_PIDFILE(, &opt_pidfile)
276 		IF_FEATURE_ACPID_COMPAT(, NULL, NULL, NULL, NULL)
277 	);
278 
279 	if (!(opts & OPT_f)) {
280 		/* No -f "Foreground", we go to background */
281 		bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
282 	}
283 
284 	if (!(opts & OPT_d)) {
285 		/* No -d "Debug", we log to log file.
286 		 * This includes any output from children.
287 		 */
288 		xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_APPEND), STDOUT_FILENO);
289 		xdup2(STDOUT_FILENO, STDERR_FILENO);
290 		/* Also, acpid's messages (but not children) will go to syslog too */
291 		openlog(applet_name, LOG_PID, LOG_DAEMON);
292 		logmode = LOGMODE_SYSLOG | LOGMODE_STDIO;
293 	}
294 	/* else: -d "Debug", log is not redirected */
295 
296 	parse_conf_file(opt_action);
297 	parse_map_file(opt_map);
298 
299 	xchdir(opt_dir);
300 
301 	/* We spawn children but don't wait for them. Prevent zombies: */
302 	bb_signals((1 << SIGCHLD), SIG_IGN);
303 	// If you enable this, (1) explain why, (2)
304 	// make sure while(poll) loop below is still interruptible
305 	// by SIGTERM et al:
306 	//bb_signals(BB_FATAL_SIGS, record_signo);
307 
308 	pfd = NULL;
309 	nfd = 0;
310 	while (1) {
311 		int fd;
312 		char *dev_event;
313 
314 		dev_event = xasprintf((opts & OPT_e) ? "%s" : "%s%u", opt_input, nfd);
315 		fd = open(dev_event, O_RDONLY | O_NONBLOCK);
316 		if (fd < 0) {
317 			if (nfd == 0)
318 				bb_simple_perror_msg_and_die(dev_event);
319 			break;
320 		}
321 		free(dev_event);
322 		pfd = xrealloc_vector(pfd, 1, nfd);
323 		pfd[nfd].fd = fd;
324 		pfd[nfd].events = POLLIN;
325 		nfd++;
326 	}
327 
328 	write_pidfile(opt_pidfile);
329 
330 	while (safe_poll(pfd, nfd, -1) > 0) {
331 		int i;
332 		for (i = 0; i < nfd; i++) {
333 			const char *event;
334 
335 			if (!(pfd[i].revents & POLLIN)) {
336 				if (pfd[i].revents == 0)
337 					continue; /* this fd has nothing */
338 
339 				/* Likely POLLERR, POLLHUP, POLLNVAL.
340 				 * Do not listen on this fd anymore.
341 				 */
342 				close(pfd[i].fd);
343 				nfd--;
344 				for (; i < nfd; i++)
345 					pfd[i].fd = pfd[i + 1].fd;
346 				break; /* do poll() again */
347 			}
348 
349 			event = NULL;
350 			if (option_mask32 & OPT_e) {
351 				char *buf;
352 				int len;
353 
354 				buf = xmalloc_reads(pfd[i].fd, NULL);
355 				/* buf = "button/power PWRB 00000080 00000000" */
356 				len = strlen(buf) - 9;
357 				if (len >= 0)
358 					buf[len] = '\0';
359 				event = find_action(NULL, buf);
360 				free(buf);
361 			} else {
362 				struct input_event ev;
363 
364 				if (sizeof(ev) != full_read(pfd[i].fd, &ev, sizeof(ev)))
365 					continue;
366 
367 				if (ev.value != 1 && ev.value != 0)
368 					continue;
369 
370 				event = find_action(&ev, NULL);
371 			}
372 			if (!event)
373 				continue;
374 			/* spawn event handler */
375 			process_event(event);
376 		}
377 	}
378 
379 	if (ENABLE_FEATURE_CLEAN_UP) {
380 		while (nfd--)
381 			close(pfd[nfd].fd);
382 		free(pfd);
383 	}
384 	remove_pidfile(opt_pidfile);
385 
386 	return EXIT_SUCCESS;
387 }
388