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