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 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, short event, void *arg)
83 {
84 	/*
85 	 * Normal signal handler rules don't apply because libevent
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, short 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 & EV_READ) {
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 & EV_WRITE) {
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 			break;
140 		case IMSG_LEN:
141 			if (datalen != sizeof(current_duration))
142 				fatalx("IMSG_LEN: got wrong size (%zu vs %zu)",
143 				    datalen, sizeof(current_duration));
144 			memcpy(&current_duration, imsg.data,
145 			    sizeof(current_duration));
146 			if (current_duration < 0)
147 				current_duration = -1;
148 			break;
149 		case IMSG_ERR:
150 			if (datalen == 0)
151 				errstr = "unknown error";
152 			else {
153 				errstr = imsg.data;
154 				errstr[datalen-1] = '\0';
155 			}
156 			log_warnx("%s; skipping %s", errstr, current_song);
157 			playlist_dropcurrent();
158 			/* fallthrough */
159 		case IMSG_EOF:
160 			if (repeat_one && current_song != NULL) {
161 				if (main_play_song(current_song))
162 					break;
163 				playlist_dropcurrent();
164 			}
165 			main_playlist_advance();
166 			if (play_state == STATE_PLAYING)
167 				control_notify(NULL, IMSG_CTL_NEXT);
168 			else
169 				control_notify(NULL, IMSG_CTL_STOP);
170 			break;
171 		default:
172 			log_debug("%s: error handling imsg %d", __func__,
173 			    imsg.hdr.type);
174 			break;
175 		}
176 		imsg_free(&imsg);
177 	}
178 
179 	if (!shut)
180 		imsg_event_add(iev);
181 	else {
182 		/* This pipe is dead.  Remove its event handler. */
183 		event_del(&iev->ev);
184 		event_loopexit(NULL);
185 	}
186 }
187 
188 static pid_t
189 start_child(enum amused_process proc, int fd)
190 {
191 	const char	*argv[7];
192 	int		 argc = 0;
193 	pid_t		 pid;
194 
195 	if (fd == -1 && debug)
196 		goto exec;
197 
198 	switch (pid = fork()) {
199 	case -1:
200 		fatal("cannot fork");
201 	case 0:
202 		break;
203 	default:
204 		close(fd);
205 		return pid;
206 	}
207 
208 	if (fd != 3) {
209 		if (fd != -1 && dup2(fd, 3) == -1)
210 			fatal("cannot setup imsg fd");
211 	} else if (fcntl(F_SETFD, 0) == -1)
212 		fatal("cannot setup imsg fd");
213 
214 exec:
215 	argv[argc++] = argv0;
216 
217 	switch (proc) {
218 	case PROC_MAIN:
219 		argv[argc++] = "-s";
220 		argv[argc++] = csock;
221 		argv[argc++] = "-Tm";
222 		break;
223 	case PROC_PLAYER:
224 		argv[argc++] = "-Tp";
225 		break;
226 	}
227 
228 	if (debug)
229 		argv[argc++] = "-d";
230 	if (verbose)
231 		argv[argc++] = "-v";
232 	argv[argc++] = NULL;
233 
234 	/* obnoxious casts */
235 	execvp(argv0, (char *const *)argv);
236 	fatal("execvp %s", argv0);
237 }
238 
239 /* daemon main routine */
240 static __dead void
241 amused_main(void)
242 {
243 	int	 pipe_main2player[2];
244 	int	 control_fd;
245 
246 	log_init(debug, LOG_DAEMON);
247 	log_setverbose(verbose);
248 	log_procinit("main");
249 
250 	if (!debug)
251 		daemon(1, 0);
252 
253 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
254 	    PF_UNSPEC, pipe_main2player) == -1)
255 		fatal("socketpair");
256 
257 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
258 
259 	event_init();
260 
261 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
262 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
263 
264 	signal_add(&ev_sigint, NULL);
265 	signal_add(&ev_sigterm, NULL);
266 
267 	signal(SIGHUP, SIG_IGN);
268 	signal(SIGCHLD, SIG_IGN);
269 	signal(SIGPIPE, SIG_IGN);
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 = EV_READ;
275 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
276 	    iev_player->handler, iev_player);
277 	event_add(&iev_player->ev, NULL);
278 
279 	if ((control_fd = control_init(csock)) == -1)
280 		fatal("control socket setup failed %s", csock);
281 	control_listen(control_fd);
282 
283 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
284 		fatal("pledge");
285 
286 	log_info("startup");
287 	event_dispatch();
288 	main_shutdown();
289 }
290 
291 int
292 main(int argc, char **argv)
293 {
294 	int ch, proc = -1;
295 
296 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
297 	log_setverbose(1);
298 
299 	argv0 = argv[0];
300 	if (argv0 == NULL)
301 		argv0 = "amused";
302 
303 	while ((ch = getopt(argc, argv, "ds:T:v")) != -1) {
304 		switch (ch) {
305 		case 'd':
306 			debug = 1;
307 			break;
308 		case 's':
309 			free(csock);
310 			csock = xstrdup(optarg);
311 			break;
312 		case 'T':
313 			switch (*optarg) {
314 			case 'm':
315 				proc = PROC_MAIN;
316 				break;
317 			case 'p':
318 				proc = PROC_PLAYER;
319 				break;
320 			default:
321 				usage();
322 			}
323 			break;
324 		case 'v':
325 			verbose++;
326 			break;
327 		default:
328 			usage();
329 		}
330 	}
331 	argv += optind;
332 	argc -= optind;
333 
334 	if (proc == PROC_MAIN)
335 		amused_main();
336 	if (proc == PROC_PLAYER)
337 		exit(player(debug, verbose));
338 
339 	if (csock == NULL)
340 		xasprintf(&csock, "/tmp/amused-%d", getuid());
341 
342 	if (argc > 0)
343 		debug = 0;
344 
345 	ctl(argc, argv);
346 }
347 
348 void
349 spawn_daemon(void)
350 {
351 	start_child(PROC_MAIN, -1);
352 }
353 
354 void
355 imsg_event_add(struct imsgev *iev)
356 {
357 	iev->events = EV_READ;
358 	if (iev->ibuf.w.queued)
359 		iev->events |= EV_WRITE;
360 
361 	event_del(&iev->ev);
362 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
363 	event_add(&iev->ev, NULL);
364 }
365 
366 int
367 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
368     pid_t pid, int fd, const void *data, uint16_t datalen)
369 {
370 	int ret;
371 
372 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
373 	    datalen)) != -1)
374 		imsg_event_add(iev);
375 
376 	return ret;
377 }
378 
379 int
380 main_send_player(uint16_t type, int fd, const void *data, size_t len)
381 {
382 	return imsg_compose_event(iev_player, type, 0, 0, fd, data, len);
383 }
384 
385 int
386 main_play_song(const char *path)
387 {
388 	struct stat sb;
389 	int fd;
390 
391 	if ((fd = open(path, O_RDONLY)) == -1) {
392 		log_warn("open %s", path);
393 		return 0;
394 	}
395 
396 	if (fstat(fd, &sb) == -1) {
397 		log_warn("failed to stat %s", path);
398 		close(fd);
399 		return 0;
400 	}
401 
402 	if (!S_ISREG(sb.st_mode)) {
403 		log_info("skipping non-regular file: %s", path);
404 		close(fd);
405 		return 0;
406 	}
407 
408 	play_state = STATE_PLAYING;
409 	main_send_player(IMSG_PLAY, fd, NULL, 0);
410 	return 1;
411 }
412 
413 void
414 main_playlist_jump(struct imsgev *iev, struct imsg *imsg)
415 {
416 	size_t datalen;
417 	char arg[PATH_MAX];
418 	const char *song;
419 
420 	datalen = IMSG_DATA_SIZE(*imsg);
421 	if (datalen != sizeof(arg)) {
422 		main_senderr(iev, "wrong size");
423 		return;
424 	}
425 
426 	memcpy(arg, imsg->data, sizeof(arg));
427 	if (arg[sizeof(arg)-1] != '\0') {
428 		main_senderr(iev, "data corrupted");
429 		return;
430 	}
431 
432 	song = playlist_jump(arg);
433 	if (song == NULL) {
434 		main_senderr(iev, "not found");
435 		return;
436 	}
437 
438 	main_send_player(IMSG_STOP, -1, NULL, 0);
439 	if (!main_play_song(song)) {
440 		main_senderr(iev, "can't play");
441 		playlist_dropcurrent();
442 		main_playlist_advance();
443 		return;
444 	}
445 
446 	main_send_status(iev);
447 }
448 
449 void
450 main_playlist_resume(void)
451 {
452 	const char *song;
453 
454 	if ((song = current_song) == NULL)
455 		song = playlist_advance();
456 
457 	for (; song != NULL; song = playlist_advance()) {
458 		if (main_play_song(song))
459 			return;
460 
461 		playlist_dropcurrent();
462 	}
463 }
464 
465 void
466 main_playlist_advance(void)
467 {
468 	const char *song;
469 
470 	for (;;) {
471 		song = playlist_advance();
472 		if (song == NULL)
473 			return;
474 
475 		if (main_play_song(song))
476 			break;
477 
478 		playlist_dropcurrent();
479 	}
480 }
481 
482 void
483 main_playlist_previous(void)
484 {
485 	const char *song;
486 
487 	for (;;) {
488 		song = playlist_previous();
489 		if (song == NULL)
490 			return;
491 
492 		if (main_play_song(song))
493 			break;
494 
495 		playlist_dropcurrent();
496 	}
497 }
498 
499 void
500 main_restart_track(void)
501 {
502 	if (current_song == NULL)
503 		return;
504 
505 	if (main_play_song(current_song))
506 		return;
507 
508 	playlist_dropcurrent();
509 	main_playlist_advance();
510 }
511 
512 void
513 main_senderr(struct imsgev *iev, const char *msg)
514 {
515 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1,
516 	    msg, strlen(msg)+1);
517 }
518 
519 void
520 main_enqueue(int tx, struct playlist *px, struct imsgev *iev,
521     struct imsg *imsg)
522 {
523 	size_t datalen;
524 	char path[PATH_MAX];
525 	const char *err = NULL;
526 
527 	datalen = IMSG_DATA_SIZE(*imsg);
528 	if (datalen != sizeof(path)) {
529 		err = "data size mismatch";
530 		goto err;
531 	}
532 
533 	memcpy(path, imsg->data, sizeof(path));
534 	if (path[datalen-1] != '\0') {
535 		err = "malformed data";
536 		goto err;
537 	}
538 
539 	if (tx)
540 		playlist_push(px, path);
541 	else
542 		playlist_enqueue(path);
543 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
544 	return;
545 err:
546 	main_senderr(iev, err);
547 }
548 
549 void
550 main_send_playlist(struct imsgev *iev)
551 {
552 	struct player_status s;
553 	size_t i;
554 
555 	for (i = 0; i < playlist.len; ++i) {
556 		memset(&s, 0, sizeof(s));
557 		strlcpy(s.path, playlist.songs[i], sizeof(s.path));
558 		s.status = play_off == i ? STATE_PLAYING : STATE_STOPPED;
559 		imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, &s,
560 		    sizeof(s));
561 	}
562 
563 	imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, NULL, 0);
564 }
565 
566 void
567 main_send_status(struct imsgev *iev)
568 {
569 	struct player_status s;
570 
571 	memset(&s, 0, sizeof(s));
572 
573 	if (current_song != NULL)
574 		strlcpy(s.path, current_song, sizeof(s.path));
575 	s.status = play_state;
576 	s.position = current_position;
577 	s.duration = current_duration;
578 	s.rp.repeat_all = repeat_all;
579 	s.rp.repeat_one = repeat_one;
580 
581 	imsg_compose_event(iev, IMSG_CTL_STATUS, 0, 0, -1, &s, sizeof(s));
582 }