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