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 	const char	*song;
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 		switch (imsg.hdr.type) {
133 		case IMSG_EOF:
134 		case IMSG_ERR:
135 			song = playlist_advance();
136 			if (song == NULL)
137 				break;
138 			/* XXX: watch out for failures! */
139 			main_play_song(song);
140 			break;
141 		default:
142 			log_debug("%s: error handling imsg %d", __func__,
143 			    imsg.hdr.type);
144 			break;
145 		}
146 		imsg_free(&imsg);
147 	}
148 
149 	if (!shut)
150 		imsg_event_add(iev);
151 	else {
152 		/* This pipe is dead.  Remove its event handler. */
153 		event_del(&iev->ev);
154 		event_loopexit(NULL);
155 	}
156 }
157 
158 static pid_t
159 start_child(enum amused_process proc, int fd)
160 {
161 	const char	*argv[5];
162 	int		 argc = 0;
163 	pid_t		 pid;
164 
165 	switch (pid = fork()) {
166 	case -1:
167 		fatal("cannot fork");
168 	case 0:
169 		break;
170 	default:
171 		close(fd);
172 		return pid;
173 	}
174 
175 	if (fd != 3) {
176 		if (dup2(fd, 3) == -1)
177 			fatal("cannot setup imsg fd");
178 	} else if (fcntl(F_SETFD, 0) == -1)
179 		fatal("cannot setup imsg fd");
180 
181 	argv[argc++] = argv0;
182 	switch (proc) {
183 	case PROC_MAIN:
184 		fatal("can not start main process");
185 	case PROC_PLAYER:
186 		argv[argc++] = "-Tp";
187 		break;
188 	}
189 
190 	if (debug)
191 		argv[argc++] = "-d";
192 	if (verbose)
193 		argv[argc++] = "-v";
194 	argv[argc++] = NULL;
195 
196 	/* obnoxious casts */
197 	execvp(argv0, (char *const *)argv);
198 	fatal("execvp %s", argv0);
199 }
200 
201 /* daemon main routine */
202 static __dead int
203 amused_main(void)
204 {
205 	int	 pipe_main2player[2];
206 	int	 control_fd;
207 
208 	log_init(debug, LOG_DAEMON);
209 	log_setverbose(verbose);
210 	log_procinit("main");
211 
212 	if (!debug)
213 		daemon(1, 0);
214 
215 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
216 	    PF_UNSPEC, pipe_main2player) == -1)
217 		fatal("socketpair");
218 
219 	player_pid = start_child(PROC_PLAYER, pipe_main2player[1]);
220 
221 	event_init();
222 
223 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
224 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
225 
226 	signal_add(&ev_sigint, NULL);
227 	signal_add(&ev_sigterm, NULL);
228 
229 	signal(SIGHUP, SIG_IGN);
230 	signal(SIGCHLD, SIG_IGN);
231 	signal(SIGPIPE, SIG_IGN);
232 
233 	iev_player = xmalloc(sizeof(*iev_player));
234 	imsg_init(&iev_player->ibuf, pipe_main2player[0]);
235 	iev_player->handler = main_dispatch_player;
236 	iev_player->events = EV_READ;
237 	event_set(&iev_player->ev, iev_player->ibuf.fd, iev_player->events,
238 	    iev_player->handler, iev_player);
239 	event_add(&iev_player->ev, NULL);
240 
241 	if ((control_fd = control_init(csock)) == -1)
242 		fatal("control socket setup failed %s", csock);
243 	control_listen(control_fd);
244 
245 	if (pledge("stdio rpath unix sendfd", NULL) == -1)
246 		fatal("pledge");
247 
248 	log_info("startup");
249 	event_dispatch();
250 	main_shutdown();
251 }
252 
253 int
254 main(int argc, char **argv)
255 {
256 	int ch, proc = PROC_MAIN;
257 
258 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized */
259 	log_setverbose(1);
260 
261 	argv0 = argv[0];
262 	if (argv0 == NULL)
263 		argv0 = "amused";
264 
265 	while ((ch = getopt(argc, argv, "ds:T:vV")) != -1) {
266 		switch (ch) {
267 		case 'd':
268 			debug = 1;
269 			break;
270 		case 's':
271 			free(csock);
272 			csock = xstrdup(optarg);
273 			break;
274 		case 'T':
275 			switch (*optarg) {
276 			case 'p':
277 				proc = PROC_PLAYER;
278 				break;
279 			default:
280 				usage();
281 			}
282 			break;
283 		case 'v':
284 			verbose++;
285 			break;
286 		case 'V':
287 			printf("%s version %s\n", getprogname(),
288 			    AMUSED_VERSION);
289 			exit(0);
290 		default:
291 			usage();
292 		}
293 	}
294 	argv += optind;
295 	argc -= optind;
296 
297 	if (proc == PROC_PLAYER)
298 		exit(player(debug, verbose));
299 
300 	if (csock == NULL)
301 		xasprintf(&csock, "/tmp/amused-%d", getuid());
302 
303 	if (argc == 0)
304 		amused_main();
305 	else
306 		ctl(argc, argv);
307 	return 0;
308 }
309 
310 void
311 imsg_event_add(struct imsgev *iev)
312 {
313 	iev->events = EV_READ;
314 	if (iev->ibuf.w.queued)
315 		iev->events |= EV_WRITE;
316 
317 	event_del(&iev->ev);
318 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
319 	event_add(&iev->ev, NULL);
320 }
321 
322 int
323 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
324     pid_t pid, int fd, const void *data, uint16_t datalen)
325 {
326 	int ret;
327 
328 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
329 	    datalen)) != -1)
330 		imsg_event_add(iev);
331 
332 	return ret;
333 }
334 
335 int
336 main_play_song(const char *song)
337 {
338 	char path[PATH_MAX] = { 0 };
339 	int fd;
340 
341 	strlcpy(path, song, sizeof(path));
342 	if ((fd = open(path, O_RDONLY)) == -1) {
343 #if todo
344 		log_warn("open %s", path);
345 		return -1;
346 #else
347 		fatal("open %s", path);
348 #endif
349 	}
350 
351 	imsg_compose_event(iev_player, IMSG_PLAY, 0, 0, fd,
352 	    path, sizeof(path));
353 	return 0;
354 }
355 
356 void
357 main_enqueue(struct imsgev *iev, struct imsg *imsg)
358 {
359 	size_t datalen;
360 	char path[PATH_MAX] = { 0 };
361 	const char *err = NULL;
362 
363 	datalen = IMSG_DATA_SIZE(*imsg);
364 	if (datalen != sizeof(path)) {
365 		err = "data size mismatch";
366 		goto err;
367 	}
368 
369 	memcpy(path, imsg->data, sizeof(path));
370 	if (path[datalen-1] != '\0') {
371 		err = "malformed data";
372 		goto err;
373 	}
374 
375 	playlist_enqueue(path);
376 	imsg_compose_event(iev, IMSG_CTL_ADD, 0, 0, -1, path, sizeof(path));
377 	return;
378 err:
379 	imsg_compose_event(iev, IMSG_CTL_ERR, 0, 0, -1, err, strlen(err)+1);
380 }