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 = playlist_current()) != 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 			/* fallthrough */
165 		case IMSG_EOF:
166 			main_playlist_advance();
167 			break;
168 
169 		default:
170 			log_debug("%s: error handling imsg %d", __func__,
171 			    imsg.hdr.type);
172 			break;
173 		}
174 		imsg_free(&imsg);
175 	}
176 
177 	if (!shut)
178 		imsg_event_add(iev);
179 	else {
180 		/* This pipe is dead.  Remove its event handler. */
181 		event_del(&iev->ev);
182 		event_loopexit(NULL);
183 	}
184 }
185 
186 static pid_t
187 start_child(enum amused_process proc, int fd)
188 {
189 	const char	*argv[5];
190 	int		 argc = 0;
191 	pid_t		 pid;
192 
193 	switch (pid = fork()) {
194 	case -1:
195 		fatal("cannot fork");
196 	case 0:
197 		break;
198 	default:
199 		close(fd);
200 		return pid;
201 	}
202 
203 	if (fd != 3) {
204 		if (fd != -1 && dup2(fd, 3) == -1)
205 			fatal("cannot setup imsg fd");
206 	} else if (fcntl(F_SETFD, 0) == -1)
207 		fatal("cannot setup imsg fd");
208 
209 	argv[argc++] = argv0;
210 	switch (proc) {
211 	case PROC_MAIN:
212 		break;
213 	case PROC_PLAYER:
214 		argv[argc++] = "-Tp";
215 		break;
216 	}
217 
218 	if (debug)
219 		argv[argc++] = "-d";
220 	if (verbose)
221 		argv[argc++] = "-v";
222 	argv[argc++] = NULL;
223 
224 	/* obnoxious casts */
225 	execvp(argv0, (char *const *)argv);
226 	fatal("execvp %s", argv0);
227 }
228 
229 /* daemon main routine */
230 static __dead int
231 amused_main(void)
232 {
233 	int	 pipe_main2player[2];
234 	int	 control_fd;
235 
236 	log_init(debug, LOG_DAEMON);
237 	log_setverbose(verbose);
238 	log_procinit("main");
239 
240 	if (!debug)
241 		daemon(1, 0);
242 
243 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
244 	    PF_UNSPEC, pipe_main2player) == -1)
245 		fatal("socketpair");
246 
247 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
248 
249 	event_init();
250 
251 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
252 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
253 	signal_set(&ev_siginfo, SIGINFO, main_sig_handler, NULL);
254 
255 	signal_add(&ev_sigint, NULL);
256 	signal_add(&ev_sigterm, NULL);
257 	signal_add(&ev_siginfo, NULL);
258 
259 	signal(SIGHUP, SIG_IGN);
260 	signal(SIGCHLD, SIG_IGN);
261 	signal(SIGPIPE, SIG_IGN);
262 
263 	iev_player = xmalloc(sizeof(*iev_player));
264 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
265 	iev_player->handler = main_dispatch_player;
266 	iev_player->events = EV_READ;
267 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
268 	    iev_player->handler, iev_player);
269 	event_add(&iev_player->ev, NULL);
270 
271 	if ((control_fd = control_init(csock)) == -1)
272 		fatal("control socket setup failed %s", csock);
273 	control_listen(control_fd);
274 
275 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
276 		fatal("pledge");
277 
278 	log_info("startup");
279 	event_dispatch();
280 	main_shutdown();
281 }
282 
283 int
284 main(int argc, char **argv)
285 {
286 	int ch, proc = PROC_MAIN;
287 
288 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
289 	log_setverbose(1);
290 
291 	argv0 = argv[0];
292 	if (argv0 == NULL)
293 		argv0 = "amused";
294 
295 	while ((ch = getopt(argc, argv, "ds:T:vV")) != -1) {
296 		switch (ch) {
297 		case 'd':
298 			debug = 1;
299 			break;
300 		case 's':
301 			free(csock);
302 			csock = xstrdup(optarg);
303 			break;
304 		case 'T':
305 			switch (*optarg) {
306 			case 'p':
307 				proc = PROC_PLAYER;
308 				break;
309 			default:
310 				usage();
311 			}
312 			break;
313 		case 'v':
314 			verbose++;
315 			break;
316 		case 'V':
317 			printf("%s version %s\n", getprogname(),
318 			    AMUSED_VERSION);
319 			exit(0);
320 		default:
321 			usage();
322 		}
323 	}
324 	argv += optind;
325 	argc -= optind;
326 
327 	if (proc == PROC_PLAYER)
328 		exit(player(debug, verbose));
329 
330 	if (csock == NULL)
331 		xasprintf(&csock, "/tmp/amused-%d", getuid());
332 
333 	if (argc == 0)
334 		amused_main();
335 	else
336 		ctl(argc, argv);
337 	return 0;
338 }
339 
340 void
341 spawn_daemon(void)
342 {
343 	debug = 0;
344 	start_child(PROC_MAIN, -1);
345 }
346 
347 void
348 imsg_event_add(struct imsgev *iev)
349 {
350 	iev->events = EV_READ;
351 	if (iev->ibuf.w.queued)
352 		iev->events |= EV_WRITE;
353 
354 	event_del(&iev->ev);
355 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
356 	event_add(&iev->ev, NULL);
357 }
358 
359 int
360 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
361     pid_t pid, int fd, const void *data, uint16_t datalen)
362 {
363 	int ret;
364 
365 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
366 	    datalen)) != -1)
367 		imsg_event_add(iev);
368 
369 	return ret;
370 }
371 
372 int
373 main_send_player(uint16_t type, int fd, const void *data, uint16_t datalen)
374 {
375 	return imsg_compose_event(iev_player, type, 0, 0, fd, data, datalen);
376 }
377 
378 int
379 main_play_song(const char *song)
380 {
381 	char path[PATH_MAX] = { 0 };
382 	int fd;
383 
384 	strlcpy(path, song, sizeof(path));
385 	if ((fd = open(path, O_RDONLY)) == -1) {
386 		log_warn("open %s", path);
387 		return 0;
388 	}
389 
390 	play_state = STATE_PLAYING;
391 	imsg_compose_event(iev_player, IMSG_PLAY, 0, 0, fd,
392 	    path, sizeof(path));
393 	return 1;
394 }
395 
396 void
397 main_playlist_advance(void)
398 {
399 	const char *song;
400 
401 	for (;;) {
402 		song = playlist_advance();
403 		if (song == NULL)
404 			return;
405 
406 		if (main_play_song(song))
407 			break;
408 
409 		playlist_dropcurrent();
410 	}
411 }
412 
413 void
414 main_restart_track(void)
415 {
416 	const char *song;
417 
418 	song = playlist_current();
419 	if (song == NULL)
420 		return;
421 
422 	if (main_play_song(song))
423 		return;
424 
425 	playlist_dropcurrent();
426 	main_playlist_advance();
427 }
428 
429 void
430 main_enqueue(struct imsgev *iev, struct imsg *imsg)
431 {
432 	size_t datalen;
433 	char path[PATH_MAX] = { 0 };
434 	const char *err = NULL;
435 
436 	datalen = IMSG_DATA_SIZE(*imsg);
437 	if (datalen != sizeof(path)) {
438 		err = "data size mismatch";
439 		goto err;
440 	}
441 
442 	memcpy(path, imsg->data, sizeof(path));
443 	if (path[datalen-1] != '\0') {
444 		err = "malformed data";
445 		goto err;
446 	}
447 
448 	playlist_enqueue(path);
449 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
450 	return;
451 err:
452 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1, err, strlen(err)+1);
453 }
454 
455 void
456 main_send_playlist(struct imsgev *iev)
457 {
458 	char path[PATH_MAX];
459 	size_t i;
460 
461 	for (i = 0; i < playlist.len; ++i) {
462 		strlcpy(path, playlist.songs[i], sizeof(path));
463 		imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, path,
464 		    sizeof(path));
465 	}
466 
467 	imsg_compose_event(iev, IMSG_CTL_SHOW, 0, 0, -1, NULL, 0);
468 }
469 
470 void
471 main_send_status(struct imsgev *iev)
472 {
473 	struct player_status s;
474 	const char *song;
475 
476 	memset(&s, 0, sizeof(s));
477 
478 	song = playlist_current();
479 	if (song != NULL)
480 		strlcpy(s.path, song, sizeof(s.path));
481 	s.status = play_state;
482 
483 	imsg_compose_event(iev, IMSG_CTL_STATUS, 0, 0, -1, &s, sizeof(s));
484 }