build: Compile with -Wdiscarded-qualifiers.
[paraslash.git] / afs.c
1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file afs.c Paraslash's audio file selector. */
4
5 #include <netinet/in.h>
6 #include <sys/socket.h>
7 #include <regex.h>
8 #include <signal.h>
9 #include <fnmatch.h>
10 #include <osl.h>
11 #include <lopsub.h>
12 #include <arpa/inet.h>
13 #include <sys/un.h>
14 #include <netdb.h>
15 #include <lopsub.h>
16
17 #include "server.lsg.h"
18 #include "server_cmd.lsg.h"
19 #include "para.h"
20 #include "error.h"
21 #include "crypt.h"
22 #include "string.h"
23 #include "afh.h"
24 #include "afs.h"
25 #include "server.h"
26 #include "net.h"
27 #include "ipc.h"
28 #include "list.h"
29 #include "sched.h"
30 #include "fd.h"
31 #include "signal.h"
32 #include "mood.h"
33 #include "sideband.h"
34 #include "command.h"
35
36 /** The osl tables used by afs. \sa \ref blob.c. */
37 enum afs_table_num {
38 /** Contains audio file information. See \ref aft.c. */
39 TBLNUM_AUDIO_FILES,
40 /** The table for the paraslash attributes. See \ref attribute.c. */
41 TBLNUM_ATTRIBUTES,
42 /**
43 * Paraslash's scoring system is based on Gaussian normal
44 * distributions, and the relevant data is stored in the rbtrees of an
45 * osl table containing only volatile columns. See \ref score.c for
46 * details.
47 */
48 TBLNUM_SCORES,
49 /**
50 * A standard blob table containing the mood definitions. For details
51 * see \ref mood.c.
52 */
53 TBLNUM_MOODS,
54 /** A blob table containing lyrics on a per-song basis. */
55 TBLNUM_LYRICS,
56 /** Another blob table for images (for example album cover art). */
57 TBLNUM_IMAGES,
58 /** Yet another blob table for storing standard playlists. */
59 TBLNUM_PLAYLIST,
60 /** How many tables are in use? */
61 NUM_AFS_TABLES
62 };
63
64 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
65 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
66 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
67 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
68 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
69 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
70 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
71 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
72 };
73
74 struct command_task {
75 /** The file descriptor for the local socket. */
76 int fd;
77 /** The associated task structure. */
78 struct task *task;
79 };
80
81 extern int mmd_mutex;
82 extern struct misc_meta_data *mmd;
83
84 static int server_socket;
85 static struct command_task command_task_struct;
86 static struct signal_task *signal_task;
87
88 static enum play_mode current_play_mode;
89 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
90
91 extern uint32_t afs_socket_cookie;
92
93 /**
94 * Struct to let command handlers execute a callback in afs context.
95 *
96 * Commands that need to change the state of afs can't change the relevant data
97 * structures directly because commands are executed in a child process, i.e.
98 * they get their own virtual address space.
99 *
100 * This structure is used by \p send_callback_request() (executed from handler
101 * context) in order to let the afs process call the specified function. An
102 * instance of that structure is written to a shared memory area together with
103 * the arguments to the callback function. The identifier of the shared memory
104 * area is written to the command socket.
105 *
106 * The afs process accepts connections on the command socket and reads the
107 * shared memory id, attaches the corresponding area, calls the given handler to
108 * perform the desired action and to optionally compute a result.
109 *
110 * The result and a \p callback_result structure is then written to another
111 * shared memory area. The identifier for that area is written to the handler's
112 * command socket, so that the handler process can read the id, attach the
113 * shared memory area and use the result.
114 *
115 * \sa \ref struct callback_result.
116 */
117 struct callback_query {
118 /** The function to be called. */
119 afs_callback *handler;
120 /** The number of bytes of the query */
121 size_t query_size;
122 };
123
124 /**
125 * Structure embedded in the result of a callback.
126 *
127 * If the callback produced a result, an instance of that structure is embedded
128 * into the shared memory area holding the result, mainly to let the command
129 * handler know the size of the result.
130 *
131 * \sa \ref struct callback_query.
132 */
133 struct callback_result {
134 /** The number of bytes of the result. */
135 size_t result_size;
136 /** The band designator (loglevel for the result). */
137 uint8_t band;
138 };
139
140 static int dispatch_result(int result_shmid, callback_result_handler *handler,
141 void *private_result_data)
142 {
143 struct osl_object result;
144 void *result_shm;
145 /* must attach r/w as result.data might get encrypted in-place. */
146 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
147 struct callback_result *cr = result_shm;
148
149 if (ret < 0) {
150 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
151 return ret;
152 }
153 result.size = cr->result_size;
154 result.data = result_shm + sizeof(*cr);
155 assert(handler);
156 ret = handler(&result, cr->band, private_result_data);
157 ret2 = shm_detach(result_shm);
158 if (ret2 < 0) {
159 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
160 if (ret >= 0)
161 ret = ret2;
162 }
163 return ret;
164 }
165
166 /**
167 * Ask the afs process to call a given function.
168 *
169 * \param f The function to be called.
170 * \param query Pointer to arbitrary data for the callback.
171 * \param result_handler Called for each shm area sent by the callback.
172 * \param private_result_data Passed verbatim to \a result_handler.
173 *
174 * This function creates a socket for communication with the afs process and a
175 * shared memory area (sma) to which the buffer pointed to by \a query is
176 * copied. It then notifies the afs process that the callback function \a f
177 * should be executed by sending the shared memory identifier (shmid) to the
178 * socket.
179 *
180 * If the callback produces a result, it sends any number of shared memory
181 * identifiers back via the socket. For each such identifier received, \a
182 * result_handler is called. The contents of the sma identified by the received
183 * shmid are passed to that function as an osl object. The private_result_data
184 * pointer is passed as the second argument to \a result_handler.
185 *
186 * \return Number of shared memory areas dispatched on success, negative on
187 * errors.
188 */
189 int send_callback_request(afs_callback *f, struct osl_object *query,
190 callback_result_handler *result_handler,
191 void *private_result_data)
192 {
193 struct callback_query *cq;
194 int ret, fd = -1, query_shmid, result_shmid;
195 void *query_shm;
196 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
197 size_t query_shm_size = sizeof(*cq);
198 int dispatch_error = 0, num_dispatched = 0;
199
200 if (query)
201 query_shm_size += query->size;
202 ret = shm_new(query_shm_size);
203 if (ret < 0)
204 return ret;
205 query_shmid = ret;
206 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
207 if (ret < 0)
208 goto out;
209 cq = query_shm;
210 cq->handler = f;
211 cq->query_size = query_shm_size - sizeof(*cq);
212
213 if (query)
214 memcpy(query_shm + sizeof(*cq), query->data, query->size);
215 ret = shm_detach(query_shm);
216 if (ret < 0)
217 goto out;
218
219 *(uint32_t *)buf = afs_socket_cookie;
220 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
221
222 ret = connect_local_socket(OPT_STRING_VAL(AFS_SOCKET));
223 if (ret < 0)
224 goto out;
225 fd = ret;
226 ret = write_all(fd, buf, sizeof(buf));
227 if (ret < 0)
228 goto out;
229 /*
230 * Read all shmids from afs.
231 *
232 * Even if the dispatcher returns an error we _must_ continue to read
233 * shmids from fd so that we can destroy all shared memory areas that
234 * have been created for us by the afs process.
235 */
236 for (;;) {
237 ret = recv_bin_buffer(fd, buf, sizeof(int));
238 if (ret <= 0)
239 goto out;
240 assert(ret == sizeof(int));
241 ret = *(int *) buf;
242 assert(ret > 0);
243 result_shmid = ret;
244 ret = dispatch_result(result_shmid, result_handler,
245 private_result_data);
246 if (ret < 0 && dispatch_error >= 0)
247 dispatch_error = ret;
248 ret = shm_destroy(result_shmid);
249 if (ret < 0)
250 PARA_CRIT_LOG("destroy result failed: %s\n",
251 para_strerror(-ret));
252 num_dispatched++;
253 }
254 out:
255 if (shm_destroy(query_shmid) < 0)
256 PARA_CRIT_LOG("shm destroy error\n");
257 if (fd >= 0)
258 close(fd);
259 if (dispatch_error < 0)
260 return dispatch_error;
261 if (ret < 0)
262 return ret;
263 return num_dispatched;
264 }
265
266 /**
267 * Wrapper for send_callback_request() which passes a lopsub parse result.
268 *
269 * \param f The callback function.
270 * \param cmd Needed for (de-)serialization.
271 * \param lpr Must match cmd.
272 * \param private_result_data Passed to send_callback_request().
273 *
274 * This function serializes the parse result given by the lpr pointer into a
275 * buffer. The buffer is sent as the query to the afs process with the callback
276 * mechanism.
277 *
278 * \return The return value of the underlying call to send_callback_request().
279 */
280 int send_lls_callback_request(afs_callback *f,
281 const struct lls_command * const cmd,
282 struct lls_parse_result *lpr, void *private_result_data)
283 {
284 struct osl_object query;
285 char *buf = NULL;
286 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
287
288 assert(ret >= 0);
289 query.data = buf;
290 ret = send_callback_request(f, &query, afs_cb_result_handler,
291 private_result_data);
292 free(buf);
293 return ret;
294 }
295
296 static int action_if_pattern_matches(struct osl_row *row, void *data)
297 {
298 struct pattern_match_data *pmd = data;
299 struct osl_object name_obj;
300 const char *p, *name;
301 int i, ret;
302
303 ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num,
304 &name_obj));
305 if (ret < 0)
306 return ret;
307 name = (char *)name_obj.data;
308 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
309 return 1;
310 if (lls_num_inputs(pmd->lpr) == 0) {
311 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
312 pmd->num_matches++;
313 return pmd->action(pmd->table, row, name, pmd->data);
314 }
315 }
316 i = pmd->input_skip;
317 for (;;) {
318 if (i >= lls_num_inputs(pmd->lpr))
319 break;
320 p = lls_input(i, pmd->lpr);
321 ret = fnmatch(p, name, pmd->fnmatch_flags);
322 if (ret != FNM_NOMATCH) {
323 if (ret != 0)
324 return -E_FNMATCH;
325 ret = pmd->action(pmd->table, row, name, pmd->data);
326 if (ret >= 0)
327 pmd->num_matches++;
328 return ret;
329
330 }
331 i++;
332 }
333 return 1;
334 }
335
336 /**
337 * Execute the given function for each matching row.
338 *
339 * \param pmd Describes what to match and how.
340 *
341 * \return Standard.
342 */
343 int for_each_matching_row(struct pattern_match_data *pmd)
344 {
345 if (pmd->pm_flags & PM_REVERSE_LOOP)
346 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
347 action_if_pattern_matches));
348 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
349 action_if_pattern_matches));
350 }
351
352 /**
353 * Compare two osl objects of string type.
354 *
355 * \param obj1 Pointer to the first object.
356 * \param obj2 Pointer to the second object.
357 *
358 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
359 * are taken into account.
360 *
361 * \return It returns an integer less than, equal to, or greater than zero if
362 * \a obj1 is found, respectively, to be less than, to match, or be greater than
363 * obj2.
364 *
365 * \sa strcmp(3), strncmp(3).
366 */
367 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
368 {
369 const char *str1 = (const char *)obj1->data;
370 const char *str2 = (const char *)obj2->data;
371 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
372 }
373
374 static int pass_afd(int fd, char *buf, size_t size)
375 {
376 struct msghdr msg = {.msg_iov = NULL};
377 struct cmsghdr *cmsg;
378 char control[255] __a_aligned(8);
379 int ret;
380 struct iovec iov;
381
382 iov.iov_base = buf;
383 iov.iov_len = size;
384
385 msg.msg_iov = &iov;
386 msg.msg_iovlen = 1;
387
388 msg.msg_control = control;
389 msg.msg_controllen = sizeof(control);
390
391 cmsg = CMSG_FIRSTHDR(&msg);
392 cmsg->cmsg_level = SOL_SOCKET;
393 cmsg->cmsg_type = SCM_RIGHTS;
394 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
395 *(int *)CMSG_DATA(cmsg) = fd;
396
397 /* Sum of the length of all control messages in the buffer */
398 msg.msg_controllen = cmsg->cmsg_len;
399 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
400 ret = sendmsg(server_socket, &msg, 0);
401 if (ret < 0) {
402 ret = -ERRNO_TO_PARA_ERROR(errno);
403 return ret;
404 }
405 return 1;
406 }
407
408 /**
409 * Pass the fd of the next audio file to the server process.
410 *
411 * This stores all information for streaming the "best" audio file in a shared
412 * memory area. The id of that area and an open file descriptor for the next
413 * audio file are passed to the server process.
414 *
415 * \return Standard.
416 *
417 * \sa \ref open_and_update_audio_file().
418 */
419 static int open_next_audio_file(void)
420 {
421 struct audio_file_data afd;
422 int ret, shmid;
423 char buf[8];
424
425 ret = open_and_update_audio_file(&afd);
426 if (ret < 0) {
427 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
428 goto no_admissible_files;
429 }
430 shmid = ret;
431 if (!write_ok(server_socket)) {
432 ret = -E_AFS_SOCKET;
433 goto destroy;
434 }
435 *(uint32_t *)buf = NEXT_AUDIO_FILE;
436 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
437 ret = pass_afd(afd.fd, buf, 8);
438 close(afd.fd);
439 if (ret >= 0)
440 return ret;
441 destroy:
442 shm_destroy(shmid);
443 return ret;
444 no_admissible_files:
445 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
446 *(uint32_t *)(buf + 4) = (uint32_t)0;
447 return write_all(server_socket, buf, 8);
448 }
449
450 /* Never fails if arg == NULL */
451 static int activate_mood_or_playlist(const char *arg, int *num_admissible,
452 char **errmsg)
453 {
454 enum play_mode mode;
455 int ret;
456
457 if (!arg) {
458 ret = change_current_mood(NULL, NULL); /* always successful */
459 mode = PLAY_MODE_MOOD;
460 } else {
461 if (!strncmp(arg, "p/", 2)) {
462 ret = playlist_open(arg + 2);
463 if (ret < 0 && errmsg)
464 *errmsg = make_message( "could not open %s",
465 arg);
466 mode = PLAY_MODE_PLAYLIST;
467 } else if (!strncmp(arg, "m/", 2)) {
468 ret = change_current_mood(arg + 2, errmsg);
469 mode = PLAY_MODE_MOOD;
470 } else {
471 if (errmsg)
472 *errmsg = make_message("%s: parse error", arg);
473 return -ERRNO_TO_PARA_ERROR(EINVAL);
474 }
475 if (ret < 0)
476 return ret;
477 }
478 if (num_admissible)
479 *num_admissible = ret;
480 current_play_mode = mode;
481 if (arg != current_mop) {
482 free(current_mop);
483 if (arg) {
484 current_mop = para_strdup(arg);
485 mutex_lock(mmd_mutex);
486 strncpy(mmd->afs_mode_string, arg,
487 sizeof(mmd->afs_mode_string));
488 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
489 mmd->events++;
490 mutex_unlock(mmd_mutex);
491 } else {
492 mutex_lock(mmd_mutex);
493 strcpy(mmd->afs_mode_string, "dummy");
494 mmd->events++;
495 mutex_unlock(mmd_mutex);
496 current_mop = NULL;
497 }
498 }
499 return 1;
500 }
501
502 /**
503 * Result handler for sending data to the para_client process.
504 *
505 * \param result The data to be sent.
506 * \param band The band designator.
507 * \param private Pointer to the command context.
508 *
509 * \return The return value of the underlying call to \ref command.c::send_sb.
510 *
511 * \sa \ref callback_result_handler, \ref command.c::send_sb.
512 */
513 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
514 void *private)
515 {
516 struct command_context *cc = private;
517
518 assert(cc);
519 switch (band) {
520 case SBD_OUTPUT:
521 case SBD_DEBUG_LOG:
522 case SBD_INFO_LOG:
523 case SBD_NOTICE_LOG:
524 case SBD_WARNING_LOG:
525 case SBD_ERROR_LOG:
526 case SBD_CRIT_LOG:
527 case SBD_EMERG_LOG:
528 assert(result->size > 0);
529 return send_sb(&cc->scc, result->data, result->size, band, true);
530 case SBD_AFS_CB_FAILURE:
531 return *(int *)(result->data);
532 default:
533 return -E_BAD_BAND;
534 }
535 }
536
537 static void flush_and_free_pb(struct para_buffer *pb)
538 {
539 int ret;
540 struct afs_max_size_handler_data *amshd = pb->private_data;
541
542 if (pb->buf && pb->size > 0) {
543 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
544 pb->offset);
545 if (ret < 0)
546 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
547 }
548 free(pb->buf);
549 }
550
551 static int com_select_callback(struct afs_callback_arg *aca)
552 {
553 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
554 const char *arg;
555 int num_admissible, ret;
556 char *errmsg;
557
558 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
559 assert(ret >= 0);
560 arg = lls_input(0, aca->lpr);
561 ret = clear_score_table();
562 if (ret < 0) {
563 para_printf(&aca->pbout, "could not clear score table\n");
564 goto free_lpr;
565 }
566 if (current_play_mode == PLAY_MODE_MOOD)
567 close_current_mood();
568 else
569 playlist_close();
570 ret = activate_mood_or_playlist(arg, &num_admissible, &errmsg);
571 if (ret >= 0)
572 goto out;
573 /* ignore subsequent errors (but log them) */
574 para_printf(&aca->pbout, "%s\n", errmsg);
575 free(errmsg);
576 para_printf(&aca->pbout, "could not activate %s\n", arg);
577 if (current_mop && strcmp(current_mop, arg) != 0) {
578 int ret2;
579 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
580 ret2 = activate_mood_or_playlist(current_mop, &num_admissible,
581 &errmsg);
582 if (ret2 >= 0)
583 goto out;
584 para_printf(&aca->pbout, "%s\n", errmsg);
585 free(errmsg);
586 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
587 current_mop, para_strerror(-ret2));
588 }
589 para_printf(&aca->pbout, "activating dummy mood\n");
590 activate_mood_or_playlist(NULL, &num_admissible, NULL);
591 out:
592 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
593 current_mop? current_mop : "dummy mood", num_admissible);
594 free_lpr:
595 lls_free_parse_result(aca->lpr, cmd);
596 return ret;
597 }
598
599 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
600 {
601 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
602 char *errctx;
603 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
604
605 if (ret < 0) {
606 send_errctx(cc, errctx);
607 return ret;
608 }
609 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
610 }
611 EXPORT_SERVER_CMD_HANDLER(select);
612
613 static void init_admissible_files(const char *arg)
614 {
615 int ret = activate_mood_or_playlist(arg, NULL, NULL);
616 if (ret < 0) {
617 assert(arg);
618 PARA_WARNING_LOG("could not activate %s: %s\n", arg,
619 para_strerror(-ret));
620 activate_mood_or_playlist(NULL, NULL, NULL);
621 }
622 }
623
624 static int setup_command_socket_or_die(void)
625 {
626 int ret, socket_fd;
627 const char *socket_name = OPT_STRING_VAL(AFS_SOCKET);
628
629 unlink(socket_name);
630 ret = create_local_socket(socket_name);
631 if (ret < 0) {
632 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
633 exit(EXIT_FAILURE);
634 }
635 socket_fd = ret;
636 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
637 socket_fd);
638 return socket_fd;
639 }
640
641 static void close_afs_tables(void)
642 {
643 int i;
644 PARA_NOTICE_LOG("closing afs_tables\n");
645 for (i = 0; i < NUM_AFS_TABLES; i++)
646 afs_tables[i].close();
647 }
648
649 static char *database_dir;
650
651 static void get_database_dir(void)
652 {
653 if (!database_dir) {
654 if (OPT_GIVEN(AFS_DATABASE_DIR))
655 database_dir = para_strdup(OPT_STRING_VAL(AFS_DATABASE_DIR));
656 else {
657 char *home = para_homedir();
658 database_dir = make_message(
659 "%s/.paraslash/afs_database-0.4", home);
660 free(home);
661 }
662 }
663 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
664 }
665
666 static int make_database_dir(void)
667 {
668 int ret;
669
670 get_database_dir();
671 ret = para_mkdir(database_dir, 0777);
672 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
673 return 1;
674 return ret;
675 }
676
677 static int open_afs_tables(void)
678 {
679 int i, ret;
680
681 get_database_dir();
682 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
683 database_dir);
684 for (i = 0; i < NUM_AFS_TABLES; i++) {
685 ret = afs_tables[i].open(database_dir);
686 if (ret >= 0)
687 continue;
688 PARA_ERROR_LOG("%s open: %s\n", afs_tables[i].name,
689 para_strerror(-ret));
690 break;
691 }
692 if (ret >= 0)
693 return ret;
694 while (i)
695 afs_tables[--i].close();
696 return ret;
697 }
698
699 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
700 {
701 int signum, ret;
702
703 if (getppid() == 1) {
704 PARA_EMERG_LOG("para_server died\n");
705 goto shutdown;
706 }
707 signum = para_next_signal(&s->rfds);
708 if (signum == 0)
709 return 0;
710 if (signum == SIGHUP) {
711 close_afs_tables();
712 parse_config_or_die(1);
713 ret = open_afs_tables();
714 if (ret < 0)
715 return ret;
716 init_admissible_files(current_mop);
717 return 0;
718 }
719 PARA_EMERG_LOG("terminating on signal %d\n", signum);
720 shutdown:
721 task_notify_all(s, E_AFS_SIGNAL);
722 return -E_AFS_SIGNAL;
723 }
724
725 static void register_signal_task(struct sched *s)
726 {
727 para_sigaction(SIGPIPE, SIG_IGN);
728 signal_task = signal_init_or_die();
729 para_install_sighandler(SIGINT);
730 para_install_sighandler(SIGTERM);
731 para_install_sighandler(SIGHUP);
732
733 signal_task->task = task_register(&(struct task_info) {
734 .name = "signal",
735 .pre_select = signal_pre_select,
736 .post_select = afs_signal_post_select,
737 .context = signal_task,
738
739 }, s);
740 }
741
742 static struct list_head afs_client_list;
743
744 /** Describes one connected afs client. */
745 struct afs_client {
746 /** Position in the afs client list. */
747 struct list_head node;
748 /** The socket file descriptor for this client. */
749 int fd;
750 /** The time the client connected. */
751 struct timeval connect_time;
752 };
753
754 static void command_pre_select(struct sched *s, void *context)
755 {
756 struct command_task *ct = context;
757 struct afs_client *client;
758
759 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
760 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
761 list_for_each_entry(client, &afs_client_list, node)
762 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
763 }
764
765 /**
766 * Send data as shared memory to a file descriptor.
767 *
768 * \param fd File descriptor to send the shmid to.
769 * \param band The band designator for this data.
770 * \param buf The buffer holding the data to be sent.
771 * \param size The size of \a buf.
772 *
773 * This function creates a shared memory area large enough to hold
774 * the content given by \a buf and \a size and sends the identifier
775 * of this area to the file descriptor \a fd.
776 *
777 * It is called by the AFS max_size handler as well as directly by the AFS
778 * command callbacks to send command output to the command handlers.
779 *
780 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
781 * and positive on success.
782 */
783 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
784 {
785 int ret, shmid;
786 void *shm;
787 struct callback_result *cr;
788
789 if (size == 0)
790 assert(band != SBD_OUTPUT);
791 ret = shm_new(size + sizeof(*cr));
792 if (ret < 0)
793 return ret;
794 shmid = ret;
795 ret = shm_attach(shmid, ATTACH_RW, &shm);
796 if (ret < 0)
797 goto err;
798 cr = shm;
799 cr->result_size = size;
800 cr->band = band;
801 if (size > 0)
802 memcpy(shm + sizeof(*cr), buf, size);
803 ret = shm_detach(shm);
804 if (ret < 0)
805 goto err;
806 ret = write_all(fd, (char *)&shmid, sizeof(int));
807 if (ret >= 0)
808 return ret;
809 err:
810 if (shm_destroy(shmid) < 0)
811 PARA_ERROR_LOG("destroy result failed\n");
812 return ret;
813 }
814
815 static int call_callback(int fd, int query_shmid)
816 {
817 void *query_shm;
818 struct callback_query *cq;
819 int ret, ret2;
820 struct afs_callback_arg aca = {.fd = fd};
821
822 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
823 if (ret < 0)
824 return ret;
825 cq = query_shm;
826 aca.query.data = (char *)query_shm + sizeof(*cq);
827 aca.query.size = cq->query_size;
828 aca.pbout.max_size = shm_get_shmmax();
829 aca.pbout.max_size_handler = afs_max_size_handler;
830 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
831 .fd = fd,
832 .band = SBD_OUTPUT
833 };
834 ret = cq->handler(&aca);
835 ret2 = shm_detach(query_shm);
836 if (ret2 < 0) {
837 if (ret < 0) /* ignore (but log) detach error */
838 PARA_ERROR_LOG("could not detach sma: %s\n",
839 para_strerror(-ret2));
840 else
841 ret = ret2;
842 }
843 flush_and_free_pb(&aca.pbout);
844 if (ret < 0) {
845 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
846 (const char *)&ret, sizeof(ret));
847 if (ret2 < 0)
848 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
849 para_strerror(-ret));
850 }
851 return ret;
852 }
853
854 static int execute_server_command(fd_set *rfds)
855 {
856 char buf[8];
857 size_t n;
858 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
859
860 if (ret < 0 || n == 0)
861 return ret;
862 buf[n] = '\0';
863 if (strcmp(buf, "new"))
864 return -ERRNO_TO_PARA_ERROR(EINVAL);
865 return open_next_audio_file();
866 }
867
868 /* returns 0 if no data available, 1 else */
869 static int execute_afs_command(int fd, fd_set *rfds)
870 {
871 uint32_t cookie;
872 int query_shmid;
873 char buf[sizeof(cookie) + sizeof(query_shmid)];
874 size_t n;
875 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
876
877 if (ret < 0)
878 goto err;
879 if (n == 0)
880 return 0;
881 if (n != sizeof(buf)) {
882 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
883 ret, (long unsigned) sizeof(buf));
884 return 1;
885 }
886 cookie = *(uint32_t *)buf;
887 if (cookie != afs_socket_cookie) {
888 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
889 (unsigned)cookie, (unsigned)afs_socket_cookie);
890 return 1;
891 }
892 query_shmid = *(int *)(buf + sizeof(cookie));
893 if (query_shmid < 0) {
894 PARA_WARNING_LOG("received invalid query shmid %d)\n",
895 query_shmid);
896 return 1;
897 }
898 ret = call_callback(fd, query_shmid);
899 if (ret >= 0)
900 return 1;
901 err:
902 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
903 return 1;
904 }
905
906 /** Shutdown connection if query has not arrived until this many seconds. */
907 #define AFS_CLIENT_TIMEOUT 3
908
909 static int command_post_select(struct sched *s, void *context)
910 {
911 struct command_task *ct = context;
912 struct sockaddr_un unix_addr;
913 struct afs_client *client, *tmp;
914 int fd, ret;
915
916 ret = task_get_notification(ct->task);
917 if (ret < 0)
918 return ret;
919 ret = execute_server_command(&s->rfds);
920 if (ret < 0) {
921 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
922 task_notify_all(s, -ret);
923 return ret;
924 }
925 /* Check the list of connected clients. */
926 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
927 ret = execute_afs_command(client->fd, &s->rfds);
928 if (ret == 0) { /* prevent bogus connection flooding */
929 struct timeval diff;
930 tv_diff(now, &client->connect_time, &diff);
931 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
932 continue;
933 PARA_WARNING_LOG("connection timeout\n");
934 }
935 close(client->fd);
936 list_del(&client->node);
937 free(client);
938 }
939 /* Accept connections on the local socket. */
940 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
941 if (ret < 0)
942 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
943 if (ret <= 0)
944 return 0;
945 ret = mark_fd_nonblocking(fd);
946 if (ret < 0) {
947 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
948 close(fd);
949 return 0;
950 }
951 client = para_malloc(sizeof(*client));
952 client->fd = fd;
953 client->connect_time = *now;
954 para_list_add(&client->node, &afs_client_list);
955 return 0;
956 }
957
958 static void register_command_task(struct sched *s)
959 {
960 struct command_task *ct = &command_task_struct;
961 ct->fd = setup_command_socket_or_die();
962
963 ct->task = task_register(&(struct task_info) {
964 .name = "afs command",
965 .pre_select = command_pre_select,
966 .post_select = command_post_select,
967 .context = ct,
968 }, s);
969 }
970
971 /**
972 * Initialize the audio file selector process.
973 *
974 * \param socket_fd File descriptor used for communication with the server.
975 */
976 __noreturn void afs_init(int socket_fd)
977 {
978 static struct sched s;
979 int i, ret;
980
981 register_signal_task(&s);
982 INIT_LIST_HEAD(&afs_client_list);
983 for (i = 0; i < NUM_AFS_TABLES; i++)
984 afs_tables[i].init(&afs_tables[i]);
985 ret = open_afs_tables();
986 if (ret < 0)
987 goto out;
988 server_socket = socket_fd;
989 ret = mark_fd_nonblocking(server_socket);
990 if (ret < 0)
991 goto out_close;
992 PARA_INFO_LOG("server_socket: %d\n", server_socket);
993 init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
994 register_command_task(&s);
995 s.default_timeout.tv_sec = 0;
996 s.default_timeout.tv_usec = 999 * 1000;
997 ret = write(socket_fd, "\0", 1);
998 if (ret != 1) {
999 if (ret == 0)
1000 errno = EINVAL;
1001 ret = -ERRNO_TO_PARA_ERROR(errno);
1002 goto out_close;
1003 }
1004 ret = schedule(&s);
1005 sched_shutdown(&s);
1006 out_close:
1007 close_afs_tables();
1008 out:
1009 if (ret < 0)
1010 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1011 exit(EXIT_FAILURE);
1012 }
1013
1014 static int com_init_callback(struct afs_callback_arg *aca)
1015 {
1016 uint32_t table_mask = *(uint32_t *)aca->query.data;
1017 int i, ret;
1018
1019 close_afs_tables();
1020 for (i = 0; i < NUM_AFS_TABLES; i++) {
1021 struct afs_table *t = &afs_tables[i];
1022
1023 if (!(table_mask & (1 << i)))
1024 continue;
1025 if (!t->create)
1026 continue;
1027 ret = t->create(database_dir);
1028 if (ret < 0) {
1029 para_printf(&aca->pbout, "cannot create table %s\n",
1030 t->name);
1031 goto out;
1032 }
1033 para_printf(&aca->pbout, "successfully created %s table\n",
1034 t->name);
1035 }
1036 ret = open_afs_tables();
1037 if (ret < 0)
1038 para_printf(&aca->pbout, "cannot open afs tables\n");
1039 out:
1040 return ret;
1041 }
1042
1043 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1044 {
1045 int i, j, ret;
1046 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1047 struct osl_object query = {.data = &table_mask,
1048 .size = sizeof(table_mask)};
1049 unsigned num_inputs = lls_num_inputs(lpr);
1050
1051 ret = make_database_dir();
1052 if (ret < 0)
1053 return ret;
1054 if (num_inputs > 0) {
1055 table_mask = 0;
1056 for (i = 0; i < num_inputs; i++) {
1057 for (j = 0; j < NUM_AFS_TABLES; j++) {
1058 struct afs_table *t = &afs_tables[j];
1059
1060 if (strcmp(lls_input(i, lpr), t->name))
1061 continue;
1062 table_mask |= (1 << j);
1063 break;
1064 }
1065 if (j == NUM_AFS_TABLES)
1066 return -E_BAD_TABLE_NAME;
1067 }
1068 }
1069 return send_callback_request(com_init_callback, &query,
1070 afs_cb_result_handler, cc);
1071 }
1072 EXPORT_SERVER_CMD_HANDLER(init);
1073
1074 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1075 {
1076 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1077 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1078 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1079 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1080 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1081 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1082 int ret;
1083
1084 if (noopt || lls_opt_given(r_a)) {
1085 ret = send_callback_request(aft_check_callback, NULL,
1086 afs_cb_result_handler, cc);
1087 if (ret < 0)
1088 return ret;
1089 }
1090 if (noopt || lls_opt_given(r_A)) {
1091 ret = send_callback_request(attribute_check_callback, NULL,
1092 afs_cb_result_handler, cc);
1093 if (ret < 0)
1094 return ret;
1095 }
1096 if (noopt || lls_opt_given(r_p)) {
1097 ret = send_callback_request(playlist_check_callback,
1098 NULL, afs_cb_result_handler, cc);
1099 if (ret < 0)
1100 return ret;
1101 }
1102 if (noopt || lls_opt_given(r_m)) {
1103 ret = send_callback_request(mood_check_callback, NULL,
1104 afs_cb_result_handler, cc);
1105 if (ret < 0)
1106 return ret;
1107 }
1108 return 1;
1109 }
1110 EXPORT_SERVER_CMD_HANDLER(check);
1111
1112 /**
1113 * The afs event dispatcher.
1114 *
1115 * \param event Type of the event.
1116 * \param pb May be \p NULL.
1117 * \param data Type depends on \a event.
1118 *
1119 * This function calls each table event handler, passing \a pb and \a data
1120 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1121 * handler returns negative, the loop is aborted.
1122 *
1123 * \return The (negative) error code of the first handler that failed, or non-negative
1124 * if all handlers succeeded.
1125 */
1126 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1127 void *data)
1128 {
1129 int i, ret;
1130
1131 for (i = 0; i < NUM_AFS_TABLES; i++) {
1132 struct afs_table *t = &afs_tables[i];
1133 if (!t->event_handler)
1134 continue;
1135 ret = t->event_handler(event, pb, data);
1136 if (ret < 0) {
1137 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1138 event, para_strerror(-ret));
1139 return ret;
1140 }
1141 }
1142 return 1;
1143 }
1144
1145 /**
1146 * Dummy event handler for the images table.
1147 *
1148 * \param event Unused.
1149 * \param pb Unused.
1150 * \param data Unused.
1151 *
1152 * \return The images table does not honor events, so this handler always
1153 * returns success.
1154 */
1155 __a_const int images_event_handler(__a_unused enum afs_events event,
1156 __a_unused struct para_buffer *pb, __a_unused void *data)
1157 {
1158 return 1;
1159 }
1160
1161 /**
1162 * Dummy event handler for the lyrics table.
1163 *
1164 * \param event Unused.
1165 * \param pb Unused.
1166 * \param data Unused.
1167 *
1168 * \return The lyrics table does not honor events, so this handler always
1169 * returns success.
1170 */
1171 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1172 __a_unused struct para_buffer *pb, __a_unused void *data)
1173 {
1174 return 1;
1175 }