1 /*
2  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "config.h"
18 
19 #include <sys/socket.h>
20 #include <sys/stat.h>
21 #include <sys/wait.h>
22 
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <limits.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <stdint.h>
30 #include <string.h>
31 #include <syslog.h>
32 #include <unistd.h>
33 
34 #include "amused.h"
35 #include "control.h"
36 #include "log.h"
37 #include "playlist.h"
38 #include "xmalloc.h"
39 
40 char		*csock = NULL;
41 int		 debug;
42 int		 verbose;
43 struct imsgev	*iev_player;
44 
45 const char	*argv0;
46 pid_t		 player_pid;
47 struct event	 ev_sigint;
48 struct event	 ev_sigterm;
49 
50 static int	 notify_seek;
51 
52 enum amused_process {
53 	PROC_MAIN,
54 	PROC_PLAYER,
55 };
56 
57 static __dead void
58 main_shutdown(void)
59 {
60 	pid_t	pid;
61 	int	status;
62 
63 	/* close pipes. */
64 	msgbuf_clear(&iev_player->ibuf.w);
65 	close(iev_player->ibuf.fd);
66 	free(iev_player);
67 
68 	log_debug("waiting for children to terminate");
69 	do {
70 		pid = wait(&status);
71 		if (pid == -1) {
72 			if (errno != EINTR && errno != ECHILD)
73 				fatal("wait");
74 		} else if (WIFSIGNALED(status))
75 			log_warnx("player terminated; signal %d",
76 			    WTERMSIG(status));
77 	} while (pid != -1 || (pid == -1 && errno == EINTR));
78 
79 	log_info("terminating");
80 	exit(0);
81 }
82 
83 static void
84 main_sig_handler(int sig, short event, void *arg)
85 {
86 	/*
87 	 * Normal signal handler rules don't apply because libevent
88 	 * decouples for us.
89 	 */
90 
91 	switch (sig) {
92 	case SIGTERM:
93 	case SIGINT:
94 		main_shutdown();
95 		break;
96 	default:
97 		fatalx("unexpected signal %d", sig);
98 	}
99 }
100 
101 static void
102 main_dispatch_player(int sig, short event, void *d)
103 {
104 	char		*errstr;
105 	struct imsgev	*iev = d;
106 	struct imsgbuf	*ibuf = &iev->ibuf;
107 	struct imsg	 imsg;
108 	size_t		 datalen;
109 	ssize_t		 n;
110 	int		 shut = 0;
111 
112 	if (event & EV_READ) {
113 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
114 			fatal("imsg_read error");
115 		if (n == 0)	/* Connection closed */
116 			shut = 1;
117 	}
118 	if (event & EV_WRITE) {
119 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
120 			fatal("msgbuf_write");
121 		if (n == 0)	/* Connection closed */
122 			shut = 1;
123 	}
124 
125 	for (;;) {
126 		if ((n = imsg_get(ibuf, &imsg)) == -1)
127 			fatal("imsg_get");
128 		if (n == 0)	/* No more messages. */
129 			break;
130 
131 		datalen = IMSG_DATA_SIZE(imsg);
132 		switch (imsg.hdr.type) {
133 		case IMSG_POS:
134 			if (datalen != sizeof(current_position))
135 				fatalx("IMSG_POS: got wrong size (%zu vs %zu)",
136 				    datalen, sizeof(current_position));
137 			memcpy(&current_position, imsg.data,
138 			    sizeof(current_position));
139 			if (current_position < 0)
140 				current_position = -1;
141 			if (notify_seek) {
142 				notify_seek = 0;
143 				control_notify(IMSG_CTL_SEEK);
144 			}
145 			break;
146 		case IMSG_LEN:
147 			if (datalen != sizeof(current_duration))
148 				fatalx("IMSG_LEN: got wrong size (%zu vs %zu)",
149 				    datalen, sizeof(current_duration));
150 			memcpy(&current_duration, imsg.data,
151 			    sizeof(current_duration));
152 			if (current_duration < 0)
153 				current_duration = -1;
154 			break;
155 		case IMSG_ERR:
156 			if (datalen == 0)
157 				errstr = "unknown error";
158 			else {
159 				errstr = imsg.data;
160 				errstr[datalen-1] = '\0';
161 			}
162 			log_warnx("%s; skipping %s", errstr, current_song);
163 			playlist_dropcurrent();
164 			/* fallthrough */
165 		case IMSG_EOF:
166 			if (repeat_one && current_song != NULL) {
167 				if (main_play_song(current_song))
168 					break;
169 				playlist_dropcurrent();
170 			}
171 			main_playlist_advance();
172 			if (play_state == STATE_PLAYING)
173 				control_notify(IMSG_CTL_NEXT);
174 			else
175 				control_notify(IMSG_CTL_STOP);
176 			break;
177 		default:
178 			log_debug("%s: error handling imsg %d", __func__,
179 			    imsg.hdr.type);
180 			break;
181 		}
182 		imsg_free(&imsg);
183 	}
184 
185 	if (!shut)
186 		imsg_event_add(iev);
187 	else {
188 		/* This pipe is dead.  Remove its event handler. */
189 		event_del(&iev->ev);
190 		event_loopexit(NULL);
191 	}
192 }
193 
194 static pid_t
195 start_child(enum amused_process proc, int fd)
196 {
197 	const char	*argv[7];
198 	int		 argc = 0;
199 	pid_t		 pid;
200 
201 	if (fd == -1 && debug)
202 		goto exec;
203 
204 	switch (pid = fork()) {
205 	case -1:
206 		fatal("cannot fork");
207 	case 0:
208 		break;
209 	default:
210 		close(fd);
211 		return pid;
212 	}
213 
214 	if (fd != 3) {
215 		if (fd != -1 && dup2(fd, 3) == -1)
216 			fatal("cannot setup imsg fd");
217 	} else if (fcntl(F_SETFD, 0) == -1)
218 		fatal("cannot setup imsg fd");
219 
220 exec:
221 	argv[argc++] = argv0;
222 
223 	switch (proc) {
224 	case PROC_MAIN:
225 		argv[argc++] = "-s";
226 		argv[argc++] = csock;
227 		argv[argc++] = "-Tm";
228 		break;
229 	case PROC_PLAYER:
230 		argv[argc++] = "-Tp";
231 		break;
232 	}
233 
234 	if (debug)
235 		argv[argc++] = "-d";
236 	if (verbose)
237 		argv[argc++] = "-v";
238 	argv[argc++] = NULL;
239 
240 	/* obnoxious casts */
241 	execvp(argv0, (char *const *)argv);
242 	fatal("execvp %s", argv0);
243 }
244 
245 /* daemon main routine */
246 static __dead void
247 amused_main(void)
248 {
249 	int	 pipe_main2player[2];
250 	int	 control_fd;
251 
252 	log_init(debug, LOG_DAEMON);
253 	log_setverbose(verbose);
254 	log_procinit("main");
255 
256 	if (!debug)
257 		daemon(1, 0);
258 
259 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
260 	    PF_UNSPEC, pipe_main2player) == -1)
261 		fatal("socketpair");
262 
263 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
264 
265 	event_init();
266 
267 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
268 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
269 
270 	signal_add(&ev_sigint, NULL);
271 	signal_add(&ev_sigterm, NULL);
272 
273 	signal(SIGHUP, SIG_IGN);
274 	signal(SIGCHLD, SIG_IGN);
275 	signal(SIGPIPE, SIG_IGN);
276 
277 	iev_player = xmalloc(sizeof(*iev_player));
278 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
279 	iev_player->handler = main_dispatch_player;
280 	iev_player->events = EV_READ;
281 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
282 	    iev_player->handler, iev_player);
283 	event_add(&iev_player->ev, NULL);
284 
285 	if ((control_fd = control_init(csock)) == -1)
286 		fatal("control socket setup failed %s", csock);
287 	control_listen(control_fd);
288 
289 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
290 		fatal("pledge");
291 
292 	log_info("startup");
293 	event_dispatch();
294 	main_shutdown();
295 }
296 
297 int
298 main(int argc, char **argv)
299 {
300 	int ch, proc = -1;
301 
302 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
303 	log_setverbose(1);
304 
305 	argv0 = argv[0];
306 	if (argv0 == NULL)
307 		argv0 = "amused";
308 
309 	while ((ch = getopt(argc, argv, "ds:T:v")) != -1) {
310 		switch (ch) {
311 		case 'd':
312 			debug = 1;
313 			break;
314 		case 's':
315 			free(csock);
316 			csock = xstrdup(optarg);
317 			break;
318 		case 'T':
319 			switch (*optarg) {
320 			case 'm':
321 				proc = PROC_MAIN;
322 				break;
323 			case 'p':
324 				proc = PROC_PLAYER;
325 				break;
326 			default:
327 				usage();
328 			}
329 			break;
330 		case 'v':
331 			verbose++;
332 			break;
333 		default:
334 			usage();
335 		}
336 	}
337 	argv += optind;
338 	argc -= optind;
339 
340 	if (proc == PROC_MAIN)
341 		amused_main();
342 	if (proc == PROC_PLAYER)
343 		exit(player(debug, verbose));
344 
345 	if (csock == NULL)
346 		xasprintf(&csock, "/tmp/amused-%d", getuid());
347 
348 	if (argc > 0)
349 		debug = 0;
350 
351 	ctl(argc, argv);
352 }
353 
354 void
355 spawn_daemon(void)
356 {
357 	start_child(PROC_MAIN, -1);
358 }
359 
360 void
361 imsg_event_add(struct imsgev *iev)
362 {
363 	iev->events = EV_READ;
364 	if (iev->ibuf.w.queued)
365 		iev->events |= EV_WRITE;
366 
367 	event_del(&iev->ev);
368 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
369 	event_add(&iev->ev, NULL);
370 }
371 
372 int
373 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
374     pid_t pid, int fd, const void *data, uint16_t datalen)
375 {
376 	int ret;
377 
378 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
379 	    datalen)) != -1)
380 		imsg_event_add(iev);
381 
382 	return ret;
383 }
384 
385 int
386 main_send_player(uint16_t type, int fd, const void *data, size_t len)
387 {
388 	return imsg_compose_event(iev_player, type, 0, 0, fd, data, len);
389 }
390 
391 int
392 main_play_song(const char *path)
393 {
394 	struct stat sb;
395 	int fd;
396 
397 	if ((fd = open(path, O_RDONLY)) == -1) {
398 		log_warn("open %s", path);
399 		return 0;
400 	}
401 
402 	if (fstat(fd, &sb) == -1) {
403 		log_warn("failed to stat %s", path);
404 		close(fd);
405 		return 0;
406 	}
407 
408 	if (!S_ISREG(sb.st_mode)) {
409 		log_info("skipping non-regular file: %s", path);
410 		close(fd);
411 		return 0;
412 	}
413 
414 	play_state = STATE_PLAYING;
415 	main_send_player(IMSG_PLAY, fd, NULL, 0);
416 	return 1;
417 }
418 
419 void
420 main_playlist_jump(struct imsgev *iev, struct imsg *imsg)
421 {
422 	size_t datalen;
423 	char arg[PATH_MAX];
424 	const char *song;
425 
426 	datalen = IMSG_DATA_SIZE(*imsg);
427 	if (datalen != sizeof(arg)) {
428 		main_senderr(iev, "wrong size");
429 		return;
430 	}
431 
432 	memcpy(arg, imsg->data, sizeof(arg));
433 	if (arg[sizeof(arg)-1] != '\0') {
434 		main_senderr(iev, "data corrupted");
435 		return;
436 	}
437 
438 	song = playlist_jump(arg);
439 	if (song == NULL) {
440 		main_senderr(iev, "not found");
441 		return;
442 	}
443 
444 	control_notify(IMSG_CTL_JUMP);
445 
446 	main_send_player(IMSG_STOP, -1, NULL, 0);
447 	if (!main_play_song(song)) {
448 		main_senderr(iev, "can't play");
449 		playlist_dropcurrent();
450 		main_playlist_advance();
451 		return;
452 	}
453 
454 	main_send_status(iev);
455 }
456 
457 void
458 main_playlist_resume(void)
459 {
460 	const char *song;
461 
462 	if ((song = current_song) == NULL)
463 		song = playlist_advance();
464 
465 	for (; song != NULL; song = playlist_advance()) {
466 		if (main_play_song(song))
467 			return;
468 
469 		playlist_dropcurrent();
470 	}
471 }
472 
473 void
474 main_playlist_advance(void)
475 {
476 	const char *song;
477 
478 	for (;;) {
479 		song = playlist_advance();
480 		if (song == NULL)
481 			return;
482 
483 		if (main_play_song(song))
484 			break;
485 
486 		playlist_dropcurrent();
487 	}
488 }
489 
490 void
491 main_playlist_previous(void)
492 {
493 	const char *song;
494 
495 	for (;;) {
496 		song = playlist_previous();
497 		if (song == NULL)
498 			return;
499 
500 		if (main_play_song(song))
501 			break;
502 
503 		playlist_dropcurrent();
504 	}
505 }
506 
507 void
508 main_senderr(struct imsgev *iev, const char *msg)
509 {
510 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1,
511 	    msg, strlen(msg)+1);
512 }
513 
514 void
515 main_enqueue(int tx, struct playlist *px, struct imsgev *iev,
516     struct imsg *imsg)
517 {
518 	size_t datalen;
519 	char path[PATH_MAX];
520 	const char *err = NULL;
521 
522 	datalen = IMSG_DATA_SIZE(*imsg);
523 	if (datalen != sizeof(path)) {
524 		err = "data size mismatch";
525 		goto err;
526 	}
527 
528 	memcpy(path, imsg->data, sizeof(path));
529 	if (path[datalen-1] != '\0') {
530 		err = "malformed data";
531 		goto err;
532 	}
533 
534 	if (tx)
535 		playlist_push(px, path);
536 	else
537 		playlist_enqueue(path);
538 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
539 	return;
540 err:
541 	main_senderr(iev, err);
542 }
543 
544 void
545 main_send_playlist(struct imsgev *iev)
546 {
547 	struct player_status s;
548 	size_t i;
549 
550 	for (i = 0; i < playlist.len; ++i) {
551 		memset(&s, 0, sizeof(s));
552 		strlcpy(s.path, playlist.songs[i], sizeof(s.path));
553 		s.status = play_off == i ? STATE_PLAYING : STATE_STOPPED;
554 		imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, &s,
555 		    sizeof(s));
556 	}
557 
558 	imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, NULL, 0);
559 }
560 
561 void
562 main_send_status(struct imsgev *iev)
563 {
564 	struct player_status s;
565 
566 	memset(&s, 0, sizeof(s));
567 
568 	if (current_song != NULL)
569 		strlcpy(s.path, current_song, sizeof(s.path));
570 	s.status = play_state;
571 	s.position = current_position;
572 	s.duration = current_duration;
573 	s.rp.repeat_all = repeat_all;
574 	s.rp.repeat_one = repeat_one;
575 
576 	imsg_compose_event(iev, IMSG_CTL_STATUS, 0, 0, -1, &s, sizeof(s));
577 }
578 
579 void
580 main_seek(struct player_seek *s)
581 {
582 	switch (play_state) {
583 	case STATE_STOPPED:
584 		main_playlist_resume();
585 		break;
586 	case STATE_PLAYING:
587 		break;
588 	case STATE_PAUSED:
589 		play_state = STATE_PLAYING;
590 		break;
591 	}
592 
593 	notify_seek = 1;
594 	main_send_player(IMSG_CTL_SEEK, -1, s, sizeof(*s));
595 }