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 	const char	*song;
142 
143 	if (event & EV_READ) {
144 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
145 			fatal("imsg_read error");
146 		if (n == 0)	/* Connection closed */
147 			shut = 1;
148 	}
149 	if (event & EV_WRITE) {
150 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
151 			fatal("msgbuf_write");
152 		if (n == 0)	/* Connection closed */
153 			shut = 1;
154 	}
155 
156 	for (;;) {
157 		if ((n = imsg_get(ibuf, &imsg)) == -1)
158 			fatal("imsg_get");
159 		if (n == 0)	/* No more messages. */
160 			break;
161 
162 		switch (imsg.hdr.type) {
163 		case IMSG_EOF:
164 		case IMSG_ERR:
165 			song = playlist_advance();
166 			if (song == NULL)
167 				break;
168 			/* XXX: watch out for failures! */
169 			main_play_song(song);
170 			break;
171 		default:
172 			log_debug("%s: error handling imsg %d", __func__,
173 			    imsg.hdr.type);
174 			break;
175 		}
176 		imsg_free(&imsg);
177 	}
178 
179 	if (!shut)
180 		imsg_event_add(iev);
181 	else {
182 		/* This pipe is dead.  Remove its event handler. */
183 		event_del(&iev->ev);
184 		event_loopexit(NULL);
185 	}
186 }
187 
188 static pid_t
189 start_child(enum amused_process proc, int fd)
190 {
191 	const char	*argv[5];
192 	int		 argc = 0;
193 	pid_t		 pid;
194 
195 	switch (pid = fork()) {
196 	case -1:
197 		fatal("cannot fork");
198 	case 0:
199 		break;
200 	default:
201 		close(fd);
202 		return pid;
203 	}
204 
205 	if (fd != 3) {
206 		if (dup2(fd, 3) == -1)
207 			fatal("cannot setup imsg fd");
208 	} else if (fcntl(F_SETFD, 0) == -1)
209 		fatal("cannot setup imsg fd");
210 
211 	argv[argc++] = argv0;
212 	switch (proc) {
213 	case PROC_MAIN:
214 		fatal("can not start main process");
215 	case PROC_PLAYER:
216 		argv[argc++] = "-Tp";
217 		break;
218 	}
219 
220 	if (debug)
221 		argv[argc++] = "-d";
222 	if (verbose)
223 		argv[argc++] = "-v";
224 	argv[argc++] = NULL;
225 
226 	/* obnoxious casts */
227 	execvp(argv0, (char *const *)argv);
228 	fatal("execvp %s", argv0);
229 }
230 
231 /* daemon main routine */
232 static __dead int
233 amused_main(void)
234 {
235 	int	 pipe_main2player[2];
236 	int	 control_fd;
237 
238 	log_init(debug, LOG_DAEMON);
239 	log_setverbose(verbose);
240 	log_procinit("main");
241 
242 	if (!debug)
243 		daemon(1, 0);
244 
245 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
246 	    PF_UNSPEC, pipe_main2player) == -1)
247 		fatal("socketpair");
248 
249 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
250 
251 	event_init();
252 
253 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
254 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
255 	signal_set(&ev_siginfo, SIGINFO, main_sig_handler, NULL);
256 
257 	signal_add(&ev_sigint, NULL);
258 	signal_add(&ev_sigterm, NULL);
259 	signal_add(&ev_siginfo, NULL);
260 
261 	signal(SIGHUP, SIG_IGN);
262 	signal(SIGCHLD, SIG_IGN);
263 	signal(SIGPIPE, SIG_IGN);
264 
265 	iev_player = xmalloc(sizeof(*iev_player));
266 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
267 	iev_player->handler = main_dispatch_player;
268 	iev_player->events = EV_READ;
269 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
270 	    iev_player->handler, iev_player);
271 	event_add(&iev_player->ev, NULL);
272 
273 	if ((control_fd = control_init(csock)) == -1)
274 		fatal("control socket setup failed %s", csock);
275 	control_listen(control_fd);
276 
277 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
278 		fatal("pledge");
279 
280 	log_info("startup");
281 	event_dispatch();
282 	main_shutdown();
283 }
284 
285 int
286 main(int argc, char **argv)
287 {
288 	int ch, proc = PROC_MAIN;
289 
290 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
291 	log_setverbose(1);
292 
293 	argv0 = argv[0];
294 	if (argv0 == NULL)
295 		argv0 = "amused";
296 
297 	while ((ch = getopt(argc, argv, "ds:T:vV")) != -1) {
298 		switch (ch) {
299 		case 'd':
300 			debug = 1;
301 			break;
302 		case 's':
303 			free(csock);
304 			csock = xstrdup(optarg);
305 			break;
306 		case 'T':
307 			switch (*optarg) {
308 			case 'p':
309 				proc = PROC_PLAYER;
310 				break;
311 			default:
312 				usage();
313 			}
314 			break;
315 		case 'v':
316 			verbose++;
317 			break;
318 		case 'V':
319 			printf("%s version %s\n", getprogname(),
320 			    AMUSED_VERSION);
321 			exit(0);
322 		default:
323 			usage();
324 		}
325 	}
326 	argv += optind;
327 	argc -= optind;
328 
329 	if (proc == PROC_PLAYER)
330 		exit(player(debug, verbose));
331 
332 	if (csock == NULL)
333 		xasprintf(&csock, "/tmp/amused-%d", getuid());
334 
335 	if (argc == 0)
336 		amused_main();
337 	else
338 		ctl(argc, argv);
339 	return 0;
340 }
341 
342 void
343 imsg_event_add(struct imsgev *iev)
344 {
345 	iev->events = EV_READ;
346 	if (iev->ibuf.w.queued)
347 		iev->events |= EV_WRITE;
348 
349 	event_del(&iev->ev);
350 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
351 	event_add(&iev->ev, NULL);
352 }
353 
354 int
355 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
356     pid_t pid, int fd, const void *data, uint16_t datalen)
357 {
358 	int ret;
359 
360 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
361 	    datalen)) != -1)
362 		imsg_event_add(iev);
363 
364 	return ret;
365 }
366 
367 int
368 main_play_song(const char *song)
369 {
370 	char path[PATH_MAX] = { 0 };
371 	int fd;
372 
373 	strlcpy(path, song, sizeof(path));
374 	if ((fd = open(path, O_RDONLY)) == -1) {
375 #if todo
376 		log_warn("open %s", path);
377 		return -1;
378 #else
379 		fatal("open %s", path);
380 #endif
381 	}
382 
383 	imsg_compose_event(iev_player, IMSG_PLAY, 0, 0, fd,
384 	    path, sizeof(path));
385 	return 0;
386 }
387 
388 void
389 main_enqueue(struct imsgev *iev, struct imsg *imsg)
390 {
391 	size_t datalen;
392 	char path[PATH_MAX] = { 0 };
393 	const char *err = NULL;
394 
395 	datalen = IMSG_DATA_SIZE(*imsg);
396 	if (datalen != sizeof(path)) {
397 		err = "data size mismatch";
398 		goto err;
399 	}
400 
401 	memcpy(path, imsg->data, sizeof(path));
402 	if (path[datalen-1] != '\0') {
403 		err = "malformed data";
404 		goto err;
405 	}
406 
407 	playlist_enqueue(path);
408 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
409 	return;
410 err:
411 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1, err, strlen(err)+1);
412 }