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 
54 enum amused_process {
55 	PROC_MAIN,
56 	PROC_PLAYER,
57 };
58 
59 __dead void
60 main_shutdown(void)
61 {
62 	pid_t	pid;
63 	int	status;
64 
65 	/* close pipes. */
66 	msgbuf_clear(&iev_player->ibuf.w);
67 	close(iev_player->ibuf.fd);
68 	free(iev_player);
69 
70 	log_debug("waiting for children to terminate");
71 	do {
72 		pid = wait(&status);
73 		if (pid == -1) {
74 			if (errno != EINTR && errno != ECHILD)
75 				fatal("wait");
76 		} else if (WIFSIGNALED(status))
77 			log_warnx("player terminated; signal %d",
78 			    WTERMSIG(status));
79 	} while (pid != -1 || (pid == -1 && errno == EINTR));
80 
81 	log_info("terminating");
82 	exit(0);
83 }
84 
85 static void
86 main_sig_handler(int sig, short event, void *arg)
87 {
88 	/*
89 	 * Normal signal handler rules don't apply because libevent
90 	 * decouples for us.
91 	 */
92 
93 	switch (sig) {
94 	case SIGTERM:
95 	case SIGINT:
96 		main_shutdown();
97 		break;
98 	default:
99 		fatalx("unexpected signal %d", sig);
100 	}
101 }
102 
103 static void
104 main_dispatch_player(int sig, short event, void *d)
105 {
106 	struct imsgev	*iev = d;
107 	struct imsgbuf	*ibuf = &iev->ibuf;
108 	struct imsg	 imsg;
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 		switch (imsg.hdr.type) {
132 		case IMSG_ERR:
133 			playlist_dropcurrent();
134 			/* fallthrough */
135 		case IMSG_EOF:
136 			if (repeat_one && current_song != NULL) {
137 				if (main_play_song(current_song))
138 					break;
139 				playlist_dropcurrent();
140 			}
141 			main_playlist_advance();
142 			if (play_state == STATE_PLAYING)
143 				control_notify(NULL, IMSG_CTL_NEXT);
144 			else
145 				control_notify(NULL, IMSG_CTL_STOP);
146 			break;
147 		default:
148 			log_debug("%s: error handling imsg %d", __func__,
149 			    imsg.hdr.type);
150 			break;
151 		}
152 		imsg_free(&imsg);
153 	}
154 
155 	if (!shut)
156 		imsg_event_add(iev);
157 	else {
158 		/* This pipe is dead.  Remove its event handler. */
159 		event_del(&iev->ev);
160 		event_loopexit(NULL);
161 	}
162 }
163 
164 static pid_t
165 start_child(enum amused_process proc, int fd)
166 {
167 	const char	*argv[6];
168 	int		 argc = 0;
169 	pid_t		 pid;
170 
171 	switch (pid = fork()) {
172 	case -1:
173 		fatal("cannot fork");
174 	case 0:
175 		break;
176 	default:
177 		close(fd);
178 		return pid;
179 	}
180 
181 	if (fd != 3) {
182 		if (fd != -1 && dup2(fd, 3) == -1)
183 			fatal("cannot setup imsg fd");
184 	} else if (fcntl(F_SETFD, 0) == -1)
185 		fatal("cannot setup imsg fd");
186 
187 	argv[argc++] = argv0;
188 
189 	switch (proc) {
190 	case PROC_MAIN:
191 		argv[argc++] = "-s";
192 		argv[argc++] = csock;
193 		break;
194 	case PROC_PLAYER:
195 		argv[argc++] = "-Tp";
196 		break;
197 	}
198 
199 	if (debug)
200 		argv[argc++] = "-d";
201 	if (verbose)
202 		argv[argc++] = "-v";
203 	argv[argc++] = NULL;
204 
205 	/* obnoxious casts */
206 	execvp(argv0, (char *const *)argv);
207 	fatal("execvp %s", argv0);
208 }
209 
210 /* daemon main routine */
211 static __dead int
212 amused_main(void)
213 {
214 	int	 pipe_main2player[2];
215 	int	 control_fd;
216 
217 	log_init(debug, LOG_DAEMON);
218 	log_setverbose(verbose);
219 	log_procinit("main");
220 
221 	if (!debug)
222 		daemon(1, 0);
223 
224 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
225 	    PF_UNSPEC, pipe_main2player) == -1)
226 		fatal("socketpair");
227 
228 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
229 
230 	event_init();
231 
232 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
233 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
234 
235 	signal_add(&ev_sigint, NULL);
236 	signal_add(&ev_sigterm, NULL);
237 
238 	signal(SIGHUP, SIG_IGN);
239 	signal(SIGCHLD, SIG_IGN);
240 	signal(SIGPIPE, SIG_IGN);
241 
242 	iev_player = xmalloc(sizeof(*iev_player));
243 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
244 	iev_player->handler = main_dispatch_player;
245 	iev_player->events = EV_READ;
246 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
247 	    iev_player->handler, iev_player);
248 	event_add(&iev_player->ev, NULL);
249 
250 	if ((control_fd = control_init(csock)) == -1)
251 		fatal("control socket setup failed %s", csock);
252 	control_listen(control_fd);
253 
254 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
255 		fatal("pledge");
256 
257 	log_info("startup");
258 	event_dispatch();
259 	main_shutdown();
260 }
261 
262 int
263 main(int argc, char **argv)
264 {
265 	int ch, proc = PROC_MAIN;
266 
267 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
268 	log_setverbose(1);
269 
270 	argv0 = argv[0];
271 	if (argv0 == NULL)
272 		argv0 = "amused";
273 
274 	while ((ch = getopt(argc, argv, "ds:T:v")) != -1) {
275 		switch (ch) {
276 		case 'd':
277 			debug = 1;
278 			break;
279 		case 's':
280 			free(csock);
281 			csock = xstrdup(optarg);
282 			break;
283 		case 'T':
284 			switch (*optarg) {
285 			case 'p':
286 				proc = PROC_PLAYER;
287 				break;
288 			default:
289 				usage();
290 			}
291 			break;
292 		case 'v':
293 			verbose++;
294 			break;
295 		default:
296 			usage();
297 		}
298 	}
299 	argv += optind;
300 	argc -= optind;
301 
302 	if (proc == PROC_PLAYER)
303 		exit(player(debug, verbose));
304 
305 	if (csock == NULL)
306 		xasprintf(&csock, "/tmp/amused-%d", getuid());
307 
308 	if (argc == 0)
309 		amused_main();
310 	else
311 		ctl(argc, argv);
312 	return 0;
313 }
314 
315 void
316 spawn_daemon(void)
317 {
318 	debug = 0;
319 	start_child(PROC_MAIN, -1);
320 }
321 
322 void
323 imsg_event_add(struct imsgev *iev)
324 {
325 	iev->events = EV_READ;
326 	if (iev->ibuf.w.queued)
327 		iev->events |= EV_WRITE;
328 
329 	event_del(&iev->ev);
330 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
331 	event_add(&iev->ev, NULL);
332 }
333 
334 int
335 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
336     pid_t pid, int fd, const void *data, uint16_t datalen)
337 {
338 	int ret;
339 
340 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
341 	    datalen)) != -1)
342 		imsg_event_add(iev);
343 
344 	return ret;
345 }
346 
347 int
348 main_send_player(uint16_t type, int fd, const void *data, uint16_t datalen)
349 {
350 	return imsg_compose_event(iev_player, type, 0, 0, fd, data, datalen);
351 }
352 
353 int
354 main_play_song(const char *song)
355 {
356 	char path[PATH_MAX] = { 0 };
357 	int fd;
358 
359 	strlcpy(path, song, sizeof(path));
360 	if ((fd = open(path, O_RDONLY)) == -1) {
361 		log_warn("open %s", path);
362 		return 0;
363 	}
364 
365 	play_state = STATE_PLAYING;
366 	imsg_compose_event(iev_player, IMSG_PLAY, 0, 0, fd,
367 	    path, sizeof(path));
368 	return 1;
369 }
370 
371 void
372 main_playlist_jump(struct imsgev *iev, struct imsg *imsg)
373 {
374 	size_t datalen;
375 	char arg[PATH_MAX];
376 	const char *song;
377 
378 	datalen = IMSG_DATA_SIZE(*imsg);
379 	if (datalen != sizeof(arg)) {
380 		main_senderr(iev, "wrong size");
381 		return;
382 	}
383 
384 	memcpy(arg, imsg->data, sizeof(arg));
385 	if (arg[sizeof(arg)-1] != '\0') {
386 		main_senderr(iev, "data corrupted");
387 		return;
388 	}
389 
390 	song = playlist_jump(arg);
391 	if (song == NULL) {
392 		main_senderr(iev, "not found");
393 		return;
394 	}
395 
396 	main_send_player(IMSG_STOP, -1, NULL, 0);
397 	if (!main_play_song(song)) {
398 		main_senderr(iev, "can't play");
399 		playlist_dropcurrent();
400 		main_playlist_advance();
401 		return;
402 	}
403 
404 	main_send_status(iev);
405 }
406 
407 void
408 main_playlist_resume(void)
409 {
410 	const char *song;
411 
412 	if ((song = current_song) == NULL)
413 		song = playlist_advance();
414 
415 	for (; song != NULL; song = playlist_advance()) {
416 		if (main_play_song(song))
417 			return;
418 
419 		playlist_dropcurrent();
420 	}
421 }
422 
423 void
424 main_playlist_advance(void)
425 {
426 	const char *song;
427 
428 	for (;;) {
429 		song = playlist_advance();
430 		if (song == NULL)
431 			return;
432 
433 		if (main_play_song(song))
434 			break;
435 
436 		playlist_dropcurrent();
437 	}
438 }
439 
440 void
441 main_playlist_previous(void)
442 {
443 	const char *song;
444 
445 	for (;;) {
446 		song = playlist_previous();
447 		if (song == NULL)
448 			return;
449 
450 		if (main_play_song(song))
451 			break;
452 
453 		playlist_dropcurrent();
454 	}
455 }
456 
457 void
458 main_restart_track(void)
459 {
460 	const char *song;
461 
462 	song = current_song;
463 	if (song == NULL)
464 		return;
465 
466 	if (main_play_song(song))
467 		return;
468 
469 	playlist_dropcurrent();
470 	main_playlist_advance();
471 }
472 
473 void
474 main_senderr(struct imsgev *iev, const char *msg)
475 {
476 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1,
477 	    msg, strlen(msg)+1);
478 }
479 
480 void
481 main_enqueue(int tx, struct playlist *px, struct imsgev *iev,
482     struct imsg *imsg)
483 {
484 	size_t datalen;
485 	char path[PATH_MAX] = { 0 };
486 	const char *err = NULL;
487 
488 	datalen = IMSG_DATA_SIZE(*imsg);
489 	if (datalen != sizeof(path)) {
490 		err = "data size mismatch";
491 		goto err;
492 	}
493 
494 	memcpy(path, imsg->data, sizeof(path));
495 	if (path[datalen-1] != '\0') {
496 		err = "malformed data";
497 		goto err;
498 	}
499 
500 	if (tx)
501 		playlist_push(px, path);
502 	else
503 		playlist_enqueue(path);
504 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
505 	return;
506 err:
507 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1, err, strlen(err)+1);
508 }
509 
510 void
511 main_send_playlist(struct imsgev *iev)
512 {
513 	struct player_status s;
514 	size_t i;
515 
516 	for (i = 0; i < playlist.len; ++i) {
517 		memset(&s, 0, sizeof(s));
518 		strlcpy(s.path, playlist.songs[i], sizeof(s.path));
519 		s.status = play_off == i ? STATE_PLAYING : STATE_STOPPED;
520 		imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, &s,
521 		    sizeof(s));
522 	}
523 
524 	imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, NULL, 0);
525 }
526 
527 void
528 main_send_status(struct imsgev *iev)
529 {
530 	struct player_status s;
531 
532 	memset(&s, 0, sizeof(s));
533 
534 	if (current_song != NULL)
535 		strlcpy(s.path, current_song, sizeof(s.path));
536 	s.status = play_state;
537 	s.rp.repeat_all = repeat_all;
538 	s.rp.repeat_one = repeat_one;
539 
540 	imsg_compose_event(iev, IMSG_CTL_STATUS, 0, 0, -1, &s, sizeof(s));
541 }