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