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 <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/socket.h>
20 #include <sys/uio.h>
21 #include <sys/wait.h>
22 
23 #include <event.h>
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <limits.h>
27 #include <sndio.h>
28 #include <signal.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <stdint.h>
32 #include <string.h>
33 #include <syslog.h>
34 #include <unistd.h>
35 #include <imsg.h>
36 
37 #include "amused.h"
38 #include "control.h"
39 #include "log.h"
40 #include "playlist.h"
41 #include "xmalloc.h"
42 
43 struct sio_hdl	*hdl;
44 char		*csock = NULL;
45 int		 debug;
46 int		 verbose;
47 struct imsgev	*iev_player;
48 
49 const char	*argv0;
50 pid_t		 player_pid;
51 struct event	 ev_sigint;
52 struct event	 ev_sigterm;
53 struct event	 ev_siginfo;
54 
55 enum amused_process {
56 	PROC_MAIN,
57 	PROC_PLAYER,
58 };
59 
60 __dead void
61 main_shutdown(void)
62 {
63 	pid_t	pid;
64 	int	status;
65 
66 	/* close pipes. */
67 	msgbuf_clear(&iev_player->ibuf.w);
68 	close(iev_player->ibuf.fd);
69 	free(iev_player);
70 
71 	log_debug("waiting for children to terminate");
72 	do {
73 		pid = wait(&status);
74 		if (pid == -1) {
75 			if (errno != EINTR && errno != ECHILD)
76 				fatal("wait");
77 		} else if (WIFSIGNALED(status))
78 			log_warnx("player terminated; signal %d",
79 			    WTERMSIG(status));
80 	} while (pid != -1 || (pid == -1 && errno == EINTR));
81 
82 	log_info("terminating");
83 	exit(0);
84 }
85 
86 static void
87 main_status(void)
88 {
89 	const char *cur;
90 
91 	switch (play_state) {
92 	case STATE_STOPPED:
93 		log_info("status: stopped");
94 		break;
95 	case STATE_PLAYING:
96 		log_info("status: playing");
97 		break;
98 	case STATE_PAUSED:
99 		log_info("status: paused");
100 		break;
101 	default:
102 		log_info("status: unknown");
103 		break;
104 	}
105 
106 	if ((cur = current_song) != NULL)
107 		log_info("playing %s", cur);
108 	else
109 		log_info("not playing anything");
110 }
111 
112 static void
113 main_sig_handler(int sig, short event, void *arg)
114 {
115 	/*
116 	 * Normal signal handler rules don't apply because libevent
117 	 * decouples for us.
118 	 */
119 
120 	switch (sig) {
121 	case SIGTERM:
122 	case SIGINT:
123 		main_shutdown();
124 		break;
125 	case SIGINFO:
126 		main_status();
127 		break;
128 	default:
129 		fatalx("unexpected signal %d", sig);
130 	}
131 }
132 
133 static void
134 main_dispatch_player(int sig, short event, void *d)
135 {
136 	struct imsgev	*iev = d;
137 	struct imsgbuf	*ibuf = &iev->ibuf;
138 	struct imsg	 imsg;
139 	ssize_t		 n;
140 	int		 shut = 0;
141 
142 	if (event & EV_READ) {
143 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
144 			fatal("imsg_read error");
145 		if (n == 0)	/* Connection closed */
146 			shut = 1;
147 	}
148 	if (event & EV_WRITE) {
149 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
150 			fatal("msgbuf_write");
151 		if (n == 0)	/* Connection closed */
152 			shut = 1;
153 	}
154 
155 	for (;;) {
156 		if ((n = imsg_get(ibuf, &imsg)) == -1)
157 			fatal("imsg_get");
158 		if (n == 0)	/* No more messages. */
159 			break;
160 
161 		switch (imsg.hdr.type) {
162 		case IMSG_ERR:
163 			playlist_dropcurrent();
164 			main_playlist_advance();
165 			break;
166 		case IMSG_EOF:
167 			if (repeat_one && current_song != NULL)
168 				if (main_play_song(current_song))
169 					break;
170 			main_playlist_advance();
171 			break;
172 
173 		default:
174 			log_debug("%s: error handling imsg %d", __func__,
175 			    imsg.hdr.type);
176 			break;
177 		}
178 		imsg_free(&imsg);
179 	}
180 
181 	if (!shut)
182 		imsg_event_add(iev);
183 	else {
184 		/* This pipe is dead.  Remove its event handler. */
185 		event_del(&iev->ev);
186 		event_loopexit(NULL);
187 	}
188 }
189 
190 static pid_t
191 start_child(enum amused_process proc, int fd)
192 {
193 	const char	*argv[6];
194 	int		 argc = 0;
195 	pid_t		 pid;
196 
197 	switch (pid = fork()) {
198 	case -1:
199 		fatal("cannot fork");
200 	case 0:
201 		break;
202 	default:
203 		close(fd);
204 		return pid;
205 	}
206 
207 	if (fd != 3) {
208 		if (fd != -1 && dup2(fd, 3) == -1)
209 			fatal("cannot setup imsg fd");
210 	} else if (fcntl(F_SETFD, 0) == -1)
211 		fatal("cannot setup imsg fd");
212 
213 	argv[argc++] = argv0;
214 
215 	switch (proc) {
216 	case PROC_MAIN:
217 		argv[argc++] = "-s";
218 		argv[argc++] = csock;
219 		break;
220 	case PROC_PLAYER:
221 		argv[argc++] = "-Tp";
222 		break;
223 	}
224 
225 	if (debug)
226 		argv[argc++] = "-d";
227 	if (verbose)
228 		argv[argc++] = "-v";
229 	argv[argc++] = NULL;
230 
231 	/* obnoxious casts */
232 	execvp(argv0, (char *const *)argv);
233 	fatal("execvp %s", argv0);
234 }
235 
236 /* daemon main routine */
237 static __dead int
238 amused_main(void)
239 {
240 	int	 pipe_main2player[2];
241 	int	 control_fd;
242 
243 	log_init(debug, LOG_DAEMON);
244 	log_setverbose(verbose);
245 	log_procinit("main");
246 
247 	if (!debug)
248 		daemon(1, 0);
249 
250 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
251 	    PF_UNSPEC, pipe_main2player) == -1)
252 		fatal("socketpair");
253 
254 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
255 
256 	event_init();
257 
258 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
259 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
260 	signal_set(&ev_siginfo, SIGINFO, main_sig_handler, NULL);
261 
262 	signal_add(&ev_sigint, NULL);
263 	signal_add(&ev_sigterm, NULL);
264 	signal_add(&ev_siginfo, NULL);
265 
266 	signal(SIGHUP, SIG_IGN);
267 	signal(SIGCHLD, SIG_IGN);
268 	signal(SIGPIPE, SIG_IGN);
269 
270 	iev_player = xmalloc(sizeof(*iev_player));
271 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
272 	iev_player->handler = main_dispatch_player;
273 	iev_player->events = EV_READ;
274 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
275 	    iev_player->handler, iev_player);
276 	event_add(&iev_player->ev, NULL);
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 	event_dispatch();
287 	main_shutdown();
288 }
289 
290 int
291 main(int argc, char **argv)
292 {
293 	int ch, proc = PROC_MAIN;
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:vV")) != -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 'p':
314 				proc = PROC_PLAYER;
315 				break;
316 			default:
317 				usage();
318 			}
319 			break;
320 		case 'v':
321 			verbose++;
322 			break;
323 		case 'V':
324 			printf("%s version %s\n", getprogname(),
325 			    AMUSED_VERSION);
326 			exit(0);
327 		default:
328 			usage();
329 		}
330 	}
331 	argv += optind;
332 	argc -= optind;
333 
334 	if (proc == PROC_PLAYER)
335 		exit(player(debug, verbose));
336 
337 	if (csock == NULL)
338 		xasprintf(&csock, "/tmp/amused-%d", getuid());
339 
340 	if (argc == 0)
341 		amused_main();
342 	else
343 		ctl(argc, argv);
344 	return 0;
345 }
346 
347 void
348 spawn_daemon(void)
349 {
350 	debug = 0;
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, uint16_t datalen)
381 {
382 	return imsg_compose_event(iev_player, type, 0, 0, fd, data, datalen);
383 }
384 
385 int
386 main_play_song(const char *song)
387 {
388 	char path[PATH_MAX] = { 0 };
389 	int fd;
390 
391 	strlcpy(path, song, sizeof(path));
392 	if ((fd = open(path, O_RDONLY)) == -1) {
393 		log_warn("open %s", path);
394 		return 0;
395 	}
396 
397 	play_state = STATE_PLAYING;
398 	imsg_compose_event(iev_player, IMSG_PLAY, 0, 0, fd,
399 	    path, sizeof(path));
400 	return 1;
401 }
402 
403 void
404 main_playlist_jump(struct imsgev *iev, struct imsg *imsg)
405 {
406 	size_t datalen;
407 	char arg[PATH_MAX];
408 	const char *song;
409 
410 	datalen = IMSG_DATA_SIZE(*imsg);
411 	if (datalen != sizeof(arg)) {
412 		main_senderr(iev, "wrong size");
413 		return;
414 	}
415 
416 	memcpy(arg, imsg->data, sizeof(arg));
417 	if (arg[sizeof(arg)-1] != '\0') {
418 		main_senderr(iev, "data corrupted");
419 		return;
420 	}
421 
422 	song = playlist_jump(arg);
423 	if (song == NULL) {
424 		main_senderr(iev, "not found");
425 		return;
426 	}
427 
428 	main_send_player(IMSG_STOP, -1, NULL, 0);
429 	if (!main_play_song(song)) {
430 		main_senderr(iev, "can't play");
431 		playlist_dropcurrent();
432 		main_playlist_advance();
433 		return;
434 	}
435 
436 	main_send_status(iev);
437 }
438 
439 void
440 main_playlist_resume(void)
441 {
442 	const char *song;
443 
444 	if ((song = current_song) == NULL)
445 		song = playlist_advance();
446 
447 	for (; song != NULL; song = playlist_advance()) {
448 		if (main_play_song(song))
449 			return;
450 
451 		playlist_dropcurrent();
452 	}
453 }
454 
455 void
456 main_playlist_advance(void)
457 {
458 	const char *song;
459 
460 	for (;;) {
461 		song = playlist_advance();
462 		if (song == NULL)
463 			return;
464 
465 		if (main_play_song(song))
466 			break;
467 
468 		playlist_dropcurrent();
469 	}
470 }
471 
472 void
473 main_playlist_previous(void)
474 {
475 	const char *song;
476 
477 	for (;;) {
478 		song = playlist_previous();
479 		if (song == NULL)
480 			return;
481 
482 		if (main_play_song(song))
483 			break;
484 
485 		playlist_dropcurrent();
486 	}
487 }
488 
489 void
490 main_restart_track(void)
491 {
492 	const char *song;
493 
494 	song = current_song;
495 	if (song == NULL)
496 		return;
497 
498 	if (main_play_song(song))
499 		return;
500 
501 	playlist_dropcurrent();
502 	main_playlist_advance();
503 }
504 
505 void
506 main_senderr(struct imsgev *iev, const char *msg)
507 {
508 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1,
509 	    msg, strlen(msg)+1);
510 }
511 
512 void
513 main_enqueue(int tx, struct playlist *px, struct imsgev *iev,
514     struct imsg *imsg)
515 {
516 	size_t datalen;
517 	char path[PATH_MAX] = { 0 };
518 	const char *err = NULL;
519 
520 	datalen = IMSG_DATA_SIZE(*imsg);
521 	if (datalen != sizeof(path)) {
522 		err = "data size mismatch";
523 		goto err;
524 	}
525 
526 	memcpy(path, imsg->data, sizeof(path));
527 	if (path[datalen-1] != '\0') {
528 		err = "malformed data";
529 		goto err;
530 	}
531 
532 	if (tx)
533 		playlist_push(px, path);
534 	else
535 		playlist_enqueue(path);
536 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
537 	return;
538 err:
539 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1, err, strlen(err)+1);
540 }
541 
542 void
543 main_send_playlist(struct imsgev *iev)
544 {
545 	struct player_status s;
546 	size_t i;
547 
548 	for (i = 0; i < playlist.len; ++i) {
549 		memset(&s, 0, sizeof(s));
550 		strlcpy(s.path, playlist.songs[i], sizeof(s.path));
551 		s.status = play_off == i ? STATE_PLAYING : STATE_STOPPED;
552 		imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, &s,
553 		    sizeof(s));
554 	}
555 
556 	imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, NULL, 0);
557 }
558 
559 void
560 main_send_status(struct imsgev *iev)
561 {
562 	struct player_status s;
563 
564 	memset(&s, 0, sizeof(s));
565 
566 	if (current_song != NULL)
567 		strlcpy(s.path, current_song, sizeof(s.path));
568 	s.status = play_state;
569 
570 	imsg_compose_event(iev, IMSG_CTL_STATUS, 0, 0, -1, &s, sizeof(s));
571 }