Minor log severity adjustments.
[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 "net.h"
26 #include "server.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 * Moods and playlists organize the current set of admissible files in
44 * an osl table which contains only volatile columns. Each row consists
45 * of a pointer to an audio file and the score value of this file.
46 */
47 TBLNUM_SCORES,
48 /**
49 * A standard blob table containing the mood definitions. For details
50 * see \ref mood.c.
51 */
52 TBLNUM_MOODS,
53 /** A blob table containing lyrics on a per-song basis. */
54 TBLNUM_LYRICS,
55 /** Another blob table for images (for example album cover art). */
56 TBLNUM_IMAGES,
57 /** Yet another blob table for storing standard playlists. */
58 TBLNUM_PLAYLIST,
59 /** How many tables are in use? */
60 NUM_AFS_TABLES
61 };
62
63 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
64 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
65 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
66 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
67 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
68 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
69 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
70 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
71 };
72
73 struct command_task {
74 /** The file descriptor for the local socket. */
75 int fd;
76 /** The associated task structure. */
77 struct task *task;
78 };
79
80 extern int mmd_mutex;
81 extern struct misc_meta_data *mmd;
82
83 static int server_socket;
84 static struct command_task command_task_struct;
85 static struct signal_task *signal_task;
86
87 static enum play_mode current_play_mode;
88 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
89
90 extern uint32_t afs_socket_cookie;
91
92 /**
93 * Passed from command handlers to afs.
94 *
95 * Command handlers cannot change the afs database directly because they run in
96 * a separate process. The callback query structure circumvents this
97 * restriction as follows. To instruct the afs process to execute a particular
98 * function, the command hander writes an instance of this structure to a
99 * shared memory area, along with the arguments to the callback function. The
100 * identifier of the shared memory area is transferred to the afs process via
101 * the command socket.
102 *
103 * The afs process reads the shared memory id from the command socket, attaches
104 * the corresponding area, and calls the callback function whose address is
105 * stored in the area.
106 *
107 * The command output, if any, is transferred back to the command handler in
108 * the same way: The afs process writes the output to a second shared memory
109 * area together with a fixed size metadata header whose format corresponds to
110 * the \ref callback_result structure. The identifier of this area is sent back
111 * to the command handler which attaches the area and forwards the output to
112 * the remote client.
113 *
114 * \sa \ref struct callback_result.
115 */
116 struct callback_query {
117 /** The function to be called. */
118 afs_callback *handler;
119 /** The number of bytes of the query */
120 size_t query_size;
121 };
122
123 /**
124 * Structure embedded in the result of a callback.
125 *
126 * If the callback produced a result, an instance of that structure is embedded
127 * into the shared memory area holding the result, mainly to let the command
128 * handler know the size of the result.
129 *
130 * \sa \ref struct callback_query.
131 */
132 struct callback_result {
133 /** The number of bytes of the result. */
134 size_t result_size;
135 /** The band designator (loglevel for the result). */
136 uint8_t band;
137 };
138
139 static int dispatch_result(int result_shmid, callback_result_handler *handler,
140 void *private_result_data)
141 {
142 struct osl_object result;
143 void *result_shm;
144 /* must attach r/w as result.data might get encrypted in-place. */
145 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
146 struct callback_result *cr = result_shm;
147
148 if (ret < 0) {
149 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
150 return ret;
151 }
152 result.size = cr->result_size;
153 result.data = result_shm + sizeof(*cr);
154 assert(handler);
155 ret = handler(&result, cr->band, private_result_data);
156 ret2 = shm_detach(result_shm);
157 if (ret2 < 0) {
158 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
159 if (ret >= 0)
160 ret = ret2;
161 }
162 return ret;
163 }
164
165 /**
166 * Ask the afs process to call a given function.
167 *
168 * \param f The function to be called.
169 * \param query Pointer to arbitrary data for the callback.
170 * \param result_handler Called for each shm area sent by the callback.
171 * \param private_result_data Passed verbatim to \a result_handler.
172 *
173 * This function creates a socket for communication with the afs process and a
174 * shared memory area (sma) to which the buffer pointed to by \a query is
175 * copied. It then notifies the afs process that the callback function \a f
176 * should be executed by sending the shared memory identifier (shmid) to the
177 * socket.
178 *
179 * If the callback produces a result, it sends any number of shared memory
180 * identifiers back via the socket. For each such identifier received, \a
181 * result_handler is called. The contents of the sma identified by the received
182 * shmid are passed to that function as an osl object. The private_result_data
183 * pointer is passed as the second argument to \a result_handler.
184 *
185 * \return Number of shared memory areas dispatched on success, negative on
186 * errors.
187 */
188 int send_callback_request(afs_callback *f, struct osl_object *query,
189 callback_result_handler *result_handler,
190 void *private_result_data)
191 {
192 struct callback_query *cq;
193 int ret, fd = -1, query_shmid, result_shmid;
194 void *query_shm;
195 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
196 size_t query_shm_size = sizeof(*cq);
197 int dispatch_error = 0, num_dispatched = 0;
198
199 if (query)
200 query_shm_size += query->size;
201 ret = shm_new(query_shm_size);
202 if (ret < 0)
203 return ret;
204 query_shmid = ret;
205 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
206 if (ret < 0)
207 goto out;
208 cq = query_shm;
209 cq->handler = f;
210 cq->query_size = query_shm_size - sizeof(*cq);
211
212 if (query)
213 memcpy(query_shm + sizeof(*cq), query->data, query->size);
214 ret = shm_detach(query_shm);
215 if (ret < 0)
216 goto out;
217
218 *(uint32_t *)buf = afs_socket_cookie;
219 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
220
221 ret = connect_local_socket(OPT_STRING_VAL(AFS_SOCKET));
222 if (ret < 0)
223 goto out;
224 fd = ret;
225 ret = write_all(fd, buf, sizeof(buf));
226 if (ret < 0)
227 goto out;
228 /*
229 * Read all shmids from afs.
230 *
231 * Even if the dispatcher returns an error we _must_ continue to read
232 * shmids from fd so that we can destroy all shared memory areas that
233 * have been created for us by the afs process.
234 */
235 for (;;) {
236 ret = recv_bin_buffer(fd, buf, sizeof(int));
237 if (ret <= 0)
238 goto out;
239 assert(ret == sizeof(int));
240 ret = *(int *) buf;
241 assert(ret > 0);
242 result_shmid = ret;
243 ret = dispatch_result(result_shmid, result_handler,
244 private_result_data);
245 if (ret < 0 && dispatch_error >= 0)
246 dispatch_error = ret;
247 ret = shm_destroy(result_shmid);
248 if (ret < 0)
249 PARA_CRIT_LOG("destroy result failed: %s\n",
250 para_strerror(-ret));
251 num_dispatched++;
252 }
253 out:
254 if (shm_destroy(query_shmid) < 0)
255 PARA_CRIT_LOG("shm destroy error\n");
256 if (fd >= 0)
257 close(fd);
258 if (dispatch_error < 0)
259 return dispatch_error;
260 if (ret < 0)
261 return ret;
262 return num_dispatched;
263 }
264
265 /**
266 * Wrapper for send_callback_request() which passes a lopsub parse result.
267 *
268 * \param f The callback function.
269 * \param cmd Needed for (de-)serialization.
270 * \param lpr Must match cmd.
271 * \param private_result_data Passed to send_callback_request().
272 *
273 * This function serializes the parse result given by the lpr pointer into a
274 * buffer. The buffer is sent as the query to the afs process with the callback
275 * mechanism.
276 *
277 * \return The return value of the underlying call to send_callback_request().
278 */
279 int send_lls_callback_request(afs_callback *f,
280 const struct lls_command * const cmd,
281 struct lls_parse_result *lpr, void *private_result_data)
282 {
283 struct osl_object query;
284 char *buf = NULL;
285 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
286
287 assert(ret >= 0);
288 query.data = buf;
289 ret = send_callback_request(f, &query, afs_cb_result_handler,
290 private_result_data);
291 free(buf);
292 return ret;
293 }
294
295 static int action_if_pattern_matches(struct osl_row *row, void *data)
296 {
297 struct pattern_match_data *pmd = data;
298 struct osl_object name_obj;
299 const char *p, *name;
300 int i, ret;
301
302 ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num,
303 &name_obj));
304 if (ret < 0)
305 return ret;
306 name = (char *)name_obj.data;
307 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
308 return 1;
309 if (lls_num_inputs(pmd->lpr) == 0) {
310 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
311 pmd->num_matches++;
312 return pmd->action(pmd->table, row, name, pmd->data);
313 }
314 }
315 i = pmd->input_skip;
316 for (;;) {
317 if (i >= lls_num_inputs(pmd->lpr))
318 break;
319 p = lls_input(i, pmd->lpr);
320 ret = fnmatch(p, name, pmd->fnmatch_flags);
321 if (ret != FNM_NOMATCH) {
322 if (ret != 0)
323 return -E_FNMATCH;
324 ret = pmd->action(pmd->table, row, name, pmd->data);
325 if (ret >= 0)
326 pmd->num_matches++;
327 return ret;
328
329 }
330 i++;
331 }
332 return 1;
333 }
334
335 /**
336 * Execute the given function for each matching row.
337 *
338 * \param pmd Describes what to match and how.
339 *
340 * \return Standard.
341 */
342 int for_each_matching_row(struct pattern_match_data *pmd)
343 {
344 if (pmd->pm_flags & PM_REVERSE_LOOP)
345 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
346 action_if_pattern_matches));
347 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
348 action_if_pattern_matches));
349 }
350
351 /**
352 * Compare two osl objects of string type.
353 *
354 * \param obj1 Pointer to the first object.
355 * \param obj2 Pointer to the second object.
356 *
357 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
358 * are taken into account.
359 *
360 * \return It returns an integer less than, equal to, or greater than zero if
361 * \a obj1 is found, respectively, to be less than, to match, or be greater than
362 * obj2.
363 *
364 * \sa strcmp(3), strncmp(3).
365 */
366 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
367 {
368 const char *str1 = obj1->data;
369 const char *str2 = obj2->data;
370 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
371 }
372
373 static int pass_afd(int fd, char *buf, size_t size)
374 {
375 struct msghdr msg = {.msg_iov = NULL};
376 struct cmsghdr *cmsg;
377 char control[255] __a_aligned(8);
378 int ret;
379 struct iovec iov;
380
381 iov.iov_base = buf;
382 iov.iov_len = size;
383
384 msg.msg_iov = &iov;
385 msg.msg_iovlen = 1;
386
387 msg.msg_control = control;
388 msg.msg_controllen = sizeof(control);
389
390 cmsg = CMSG_FIRSTHDR(&msg);
391 cmsg->cmsg_level = SOL_SOCKET;
392 cmsg->cmsg_type = SCM_RIGHTS;
393 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
394 *(int *)CMSG_DATA(cmsg) = fd;
395
396 /* Sum of the length of all control messages in the buffer */
397 msg.msg_controllen = cmsg->cmsg_len;
398 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
399 ret = sendmsg(server_socket, &msg, 0);
400 if (ret < 0) {
401 ret = -ERRNO_TO_PARA_ERROR(errno);
402 return ret;
403 }
404 return 1;
405 }
406
407 /**
408 * Pass the fd of the next audio file to the server process.
409 *
410 * This stores all information for streaming the "best" audio file in a shared
411 * memory area. The id of that area and an open file descriptor for the next
412 * audio file are passed to the server process.
413 *
414 * \return Standard.
415 *
416 * \sa \ref open_and_update_audio_file().
417 */
418 static int open_next_audio_file(void)
419 {
420 int ret, shmid, fd;
421 char buf[8];
422
423 ret = open_and_update_audio_file(&fd);
424 if (ret < 0) {
425 if (ret != -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
426 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
427 goto no_admissible_files;
428 }
429 shmid = ret;
430 if (!write_ok(server_socket)) {
431 ret = -E_AFS_SOCKET;
432 goto destroy;
433 }
434 *(uint32_t *)buf = NEXT_AUDIO_FILE;
435 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
436 ret = pass_afd(fd, buf, 8);
437 close(fd);
438 if (ret >= 0)
439 return ret;
440 destroy:
441 shm_destroy(shmid);
442 return ret;
443 no_admissible_files:
444 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
445 *(uint32_t *)(buf + 4) = (uint32_t)0;
446 return write_all(server_socket, buf, 8);
447 }
448
449 static int activate_mood_or_playlist(const char *arg, int *num_admissible,
450 char **errmsg)
451 {
452 enum play_mode mode;
453 int ret;
454
455 if (!arg) {
456 mode = PLAY_MODE_MOOD;
457 ret = change_current_mood(NULL, errmsg);
458 if (ret < 0) {
459 if (num_admissible)
460 *num_admissible = 0;
461 return ret;
462 }
463 } else {
464 if (!strncmp(arg, "p/", 2)) {
465 ret = playlist_open(arg + 2);
466 if (ret < 0 && errmsg)
467 *errmsg = make_message( "could not open %s",
468 arg);
469 mode = PLAY_MODE_PLAYLIST;
470 } else if (!strncmp(arg, "m/", 2)) {
471 ret = change_current_mood(arg + 2, errmsg);
472 mode = PLAY_MODE_MOOD;
473 } else {
474 if (errmsg)
475 *errmsg = make_message("%s: parse error", arg);
476 return -ERRNO_TO_PARA_ERROR(EINVAL);
477 }
478 if (ret < 0)
479 return ret;
480 }
481 if (num_admissible)
482 *num_admissible = ret;
483 current_play_mode = mode;
484 /*
485 * We get called with arg == current_mop from the signal dispatcher
486 * after SIGHUP and from the error path of the select command to
487 * re-select the current mood or playlist. In this case the assignment
488 * to current_mop below would result in a use-after-free condition.
489 */
490 if (arg != current_mop) {
491 free(current_mop);
492 if (arg) {
493 current_mop = para_strdup(arg);
494 mutex_lock(mmd_mutex);
495 strncpy(mmd->afs_mode_string, arg,
496 sizeof(mmd->afs_mode_string));
497 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
498 mmd->events++;
499 mutex_unlock(mmd_mutex);
500 } else {
501 mutex_lock(mmd_mutex);
502 strcpy(mmd->afs_mode_string, "dummy");
503 mmd->events++;
504 mutex_unlock(mmd_mutex);
505 current_mop = NULL;
506 }
507 }
508 return 1;
509 }
510
511 /**
512 * Result handler for sending data to the para_client process.
513 *
514 * \param result The data to be sent.
515 * \param band The band designator.
516 * \param private Pointer to the command context.
517 *
518 * \return The return value of the underlying call to \ref command.c::send_sb.
519 *
520 * \sa \ref callback_result_handler, \ref command.c::send_sb.
521 */
522 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
523 void *private)
524 {
525 struct command_context *cc = private;
526
527 assert(cc);
528 switch (band) {
529 case SBD_OUTPUT:
530 case SBD_DEBUG_LOG:
531 case SBD_INFO_LOG:
532 case SBD_NOTICE_LOG:
533 case SBD_WARNING_LOG:
534 case SBD_ERROR_LOG:
535 case SBD_CRIT_LOG:
536 case SBD_EMERG_LOG:
537 assert(result->size > 0);
538 return send_sb(&cc->scc, result->data, result->size, band, true);
539 case SBD_AFS_CB_FAILURE:
540 return *(int *)(result->data);
541 default:
542 return -E_BAD_BAND;
543 }
544 }
545
546 static void flush_and_free_pb(struct para_buffer *pb)
547 {
548 int ret;
549 struct afs_max_size_handler_data *amshd = pb->private_data;
550
551 if (pb->buf && pb->size > 0) {
552 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
553 pb->offset);
554 if (ret < 0)
555 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
556 }
557 free(pb->buf);
558 }
559
560 static int com_select_callback(struct afs_callback_arg *aca)
561 {
562 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
563 const char *arg;
564 int num_admissible, ret;
565 char *errmsg;
566
567 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
568 assert(ret >= 0);
569 arg = lls_input(0, aca->lpr);
570 ret = clear_score_table();
571 if (ret < 0) {
572 para_printf(&aca->pbout, "could not clear score table\n");
573 goto free_lpr;
574 }
575 if (current_play_mode == PLAY_MODE_MOOD)
576 close_current_mood();
577 else
578 playlist_close();
579 ret = activate_mood_or_playlist(arg, &num_admissible, &errmsg);
580 if (ret >= 0)
581 goto out;
582 /* ignore subsequent errors (but log them) */
583 para_printf(&aca->pbout, "%s\n", errmsg);
584 free(errmsg);
585 para_printf(&aca->pbout, "could not activate %s\n", arg);
586 if (current_mop && strcmp(current_mop, arg) != 0) {
587 int ret2;
588 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
589 ret2 = activate_mood_or_playlist(current_mop, &num_admissible,
590 &errmsg);
591 if (ret2 >= 0)
592 goto out;
593 para_printf(&aca->pbout, "%s\n", errmsg);
594 free(errmsg);
595 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
596 current_mop, para_strerror(-ret2));
597 }
598 para_printf(&aca->pbout, "activating dummy mood\n");
599 activate_mood_or_playlist(NULL, &num_admissible, NULL);
600 out:
601 para_printf(&aca->pbout, "activated %s (%d admissible file%s)\n",
602 current_mop? current_mop : "dummy mood", num_admissible,
603 num_admissible == 1? "" : "s");
604 free_lpr:
605 lls_free_parse_result(aca->lpr, cmd);
606 return ret;
607 }
608
609 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
610 {
611 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
612 char *errctx;
613 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
614
615 if (ret < 0) {
616 send_errctx(cc, errctx);
617 return ret;
618 }
619 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
620 }
621 EXPORT_SERVER_CMD_HANDLER(select);
622
623 static void init_admissible_files(const char *arg)
624 {
625 int ret = activate_mood_or_playlist(arg, NULL, NULL);
626 if (ret < 0) {
627 PARA_WARNING_LOG("could not activate %s: %s\n", arg,
628 para_strerror(-ret));
629 if (arg)
630 activate_mood_or_playlist(NULL, NULL, NULL);
631 }
632 }
633
634 static int setup_command_socket_or_die(void)
635 {
636 int ret, socket_fd;
637 const char *socket_name = OPT_STRING_VAL(AFS_SOCKET);
638
639 unlink(socket_name);
640 ret = create_local_socket(socket_name);
641 if (ret < 0) {
642 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
643 exit(EXIT_FAILURE);
644 }
645 socket_fd = ret;
646 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
647 socket_fd);
648 return socket_fd;
649 }
650
651 static char *database_dir;
652
653 static void close_afs_tables(void)
654 {
655 int i;
656 PARA_NOTICE_LOG("closing afs tables\n");
657 for (i = 0; i < NUM_AFS_TABLES; i++)
658 afs_tables[i].close();
659 free(database_dir);
660 database_dir = NULL;
661 }
662
663 static void get_database_dir(void)
664 {
665 if (!database_dir) {
666 if (OPT_GIVEN(AFS_DATABASE_DIR))
667 database_dir = para_strdup(OPT_STRING_VAL(AFS_DATABASE_DIR));
668 else {
669 char *home = para_homedir();
670 database_dir = make_message(
671 "%s/.paraslash/afs_database-0.7", home);
672 free(home);
673 }
674 }
675 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
676 }
677
678 static int make_database_dir(void)
679 {
680 int ret;
681
682 get_database_dir();
683 ret = para_mkdir(database_dir, 0777);
684 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
685 return 1;
686 return ret;
687 }
688
689 static int open_afs_tables(void)
690 {
691 int i, ret;
692
693 get_database_dir();
694 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
695 database_dir);
696 for (i = 0; i < NUM_AFS_TABLES; i++) {
697 ret = afs_tables[i].open(database_dir);
698 if (ret >= 0)
699 continue;
700 PARA_ERROR_LOG("could not open %s\n", afs_tables[i].name);
701 break;
702 }
703 if (ret >= 0)
704 return ret;
705 while (i)
706 afs_tables[--i].close();
707 return ret;
708 }
709
710 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
711 {
712 int signum, ret;
713
714 if (getppid() == 1) {
715 PARA_EMERG_LOG("para_server died\n");
716 goto shutdown;
717 }
718 signum = para_next_signal(&s->rfds);
719 if (signum == 0)
720 return 0;
721 if (signum == SIGHUP) {
722 close_afs_tables();
723 parse_config_or_die(1);
724 ret = open_afs_tables();
725 if (ret < 0)
726 return ret;
727 init_admissible_files(current_mop);
728 return 0;
729 }
730 PARA_EMERG_LOG("terminating on signal %d\n", signum);
731 shutdown:
732 task_notify_all(s, E_AFS_SIGNAL);
733 return -E_AFS_SIGNAL;
734 }
735
736 static void register_signal_task(struct sched *s)
737 {
738 para_sigaction(SIGPIPE, SIG_IGN);
739 signal_task = signal_init_or_die();
740 para_install_sighandler(SIGINT);
741 para_install_sighandler(SIGTERM);
742 para_install_sighandler(SIGHUP);
743
744 signal_task->task = task_register(&(struct task_info) {
745 .name = "signal",
746 .pre_select = signal_pre_select,
747 .post_select = afs_signal_post_select,
748 .context = signal_task,
749
750 }, s);
751 }
752
753 static struct list_head afs_client_list;
754
755 /** Describes one connected afs client. */
756 struct afs_client {
757 /** Position in the afs client list. */
758 struct list_head node;
759 /** The socket file descriptor for this client. */
760 int fd;
761 /** The time the client connected. */
762 struct timeval connect_time;
763 };
764
765 static void command_pre_select(struct sched *s, void *context)
766 {
767 struct command_task *ct = context;
768 struct afs_client *client;
769
770 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
771 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
772 list_for_each_entry(client, &afs_client_list, node)
773 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
774 }
775
776 /**
777 * Send data as shared memory to a file descriptor.
778 *
779 * \param fd File descriptor to send the shmid to.
780 * \param band The band designator for this data.
781 * \param buf The buffer holding the data to be sent.
782 * \param size The size of \a buf.
783 *
784 * This function creates a shared memory area large enough to hold
785 * the content given by \a buf and \a size and sends the identifier
786 * of this area to the file descriptor \a fd.
787 *
788 * It is called by the AFS max_size handler as well as directly by the AFS
789 * command callbacks to send command output to the command handlers.
790 *
791 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
792 * and positive on success.
793 */
794 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
795 {
796 int ret, shmid;
797 void *shm;
798 struct callback_result *cr;
799
800 if (size == 0)
801 assert(band != SBD_OUTPUT);
802 ret = shm_new(size + sizeof(*cr));
803 if (ret < 0)
804 return ret;
805 shmid = ret;
806 ret = shm_attach(shmid, ATTACH_RW, &shm);
807 if (ret < 0)
808 goto err;
809 cr = shm;
810 cr->result_size = size;
811 cr->band = band;
812 if (size > 0)
813 memcpy(shm + sizeof(*cr), buf, size);
814 ret = shm_detach(shm);
815 if (ret < 0)
816 goto err;
817 ret = write_all(fd, (char *)&shmid, sizeof(int));
818 if (ret >= 0)
819 return ret;
820 err:
821 if (shm_destroy(shmid) < 0)
822 PARA_ERROR_LOG("destroy result failed\n");
823 return ret;
824 }
825
826 static int call_callback(int fd, int query_shmid)
827 {
828 void *query_shm;
829 struct callback_query *cq;
830 int ret, ret2;
831 struct afs_callback_arg aca = {.fd = fd};
832
833 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
834 if (ret < 0)
835 return ret;
836 cq = query_shm;
837 aca.query.data = (char *)query_shm + sizeof(*cq);
838 aca.query.size = cq->query_size;
839 aca.pbout.max_size = shm_get_shmmax();
840 aca.pbout.max_size_handler = afs_max_size_handler;
841 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
842 .fd = fd,
843 .band = SBD_OUTPUT
844 };
845 ret = cq->handler(&aca);
846 ret2 = shm_detach(query_shm);
847 if (ret2 < 0) {
848 if (ret < 0) /* ignore (but log) detach error */
849 PARA_ERROR_LOG("could not detach sma: %s\n",
850 para_strerror(-ret2));
851 else
852 ret = ret2;
853 }
854 flush_and_free_pb(&aca.pbout);
855 if (ret < 0) {
856 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
857 (const char *)&ret, sizeof(ret));
858 if (ret2 < 0)
859 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
860 para_strerror(-ret));
861 }
862 return ret;
863 }
864
865 static int execute_server_command(fd_set *rfds)
866 {
867 char buf[8];
868 size_t n;
869 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
870
871 if (ret < 0 || n == 0)
872 return ret;
873 buf[n] = '\0';
874 if (strcmp(buf, "new"))
875 return -ERRNO_TO_PARA_ERROR(EINVAL);
876 return open_next_audio_file();
877 }
878
879 /* returns 0 if no data available, 1 else */
880 static int execute_afs_command(int fd, fd_set *rfds)
881 {
882 uint32_t cookie;
883 int query_shmid;
884 char buf[sizeof(cookie) + sizeof(query_shmid)];
885 size_t n;
886 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
887
888 if (ret < 0)
889 goto err;
890 if (n == 0)
891 return 0;
892 if (n != sizeof(buf)) {
893 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
894 ret, (long unsigned) sizeof(buf));
895 return 1;
896 }
897 cookie = *(uint32_t *)buf;
898 if (cookie != afs_socket_cookie) {
899 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
900 (unsigned)cookie, (unsigned)afs_socket_cookie);
901 return 1;
902 }
903 query_shmid = *(int *)(buf + sizeof(cookie));
904 if (query_shmid < 0) {
905 PARA_WARNING_LOG("received invalid query shmid %d)\n",
906 query_shmid);
907 return 1;
908 }
909 ret = call_callback(fd, query_shmid);
910 if (ret >= 0)
911 return 1;
912 err:
913 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
914 return 1;
915 }
916
917 /** Shutdown connection if query has not arrived until this many seconds. */
918 #define AFS_CLIENT_TIMEOUT 3
919
920 static int command_post_select(struct sched *s, void *context)
921 {
922 struct command_task *ct = context;
923 struct sockaddr_un unix_addr;
924 struct afs_client *client, *tmp;
925 int fd, ret;
926
927 ret = task_get_notification(ct->task);
928 if (ret < 0)
929 return ret;
930 ret = execute_server_command(&s->rfds);
931 if (ret < 0) {
932 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
933 task_notify_all(s, -ret);
934 return ret;
935 }
936 /* Check the list of connected clients. */
937 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
938 ret = execute_afs_command(client->fd, &s->rfds);
939 if (ret == 0) { /* prevent bogus connection flooding */
940 struct timeval diff;
941 tv_diff(now, &client->connect_time, &diff);
942 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
943 continue;
944 PARA_WARNING_LOG("connection timeout\n");
945 }
946 close(client->fd);
947 list_del(&client->node);
948 free(client);
949 }
950 /* Accept connections on the local socket. */
951 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
952 if (ret < 0)
953 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
954 if (ret <= 0)
955 return 0;
956 ret = mark_fd_nonblocking(fd);
957 if (ret < 0) {
958 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
959 close(fd);
960 return 0;
961 }
962 client = para_malloc(sizeof(*client));
963 client->fd = fd;
964 client->connect_time = *now;
965 para_list_add(&client->node, &afs_client_list);
966 return 0;
967 }
968
969 static void register_command_task(struct sched *s)
970 {
971 struct command_task *ct = &command_task_struct;
972 ct->fd = setup_command_socket_or_die();
973
974 ct->task = task_register(&(struct task_info) {
975 .name = "afs command",
976 .pre_select = command_pre_select,
977 .post_select = command_post_select,
978 .context = ct,
979 }, s);
980 }
981
982 /**
983 * Initialize the audio file selector process.
984 *
985 * \param socket_fd File descriptor used for communication with the server.
986 */
987 __noreturn void afs_init(int socket_fd)
988 {
989 static struct sched s;
990 int i, ret;
991
992 register_signal_task(&s);
993 init_list_head(&afs_client_list);
994 for (i = 0; i < NUM_AFS_TABLES; i++)
995 afs_tables[i].init(&afs_tables[i]);
996 ret = open_afs_tables();
997 if (ret < 0)
998 goto out;
999 server_socket = socket_fd;
1000 ret = mark_fd_nonblocking(server_socket);
1001 if (ret < 0)
1002 goto out_close;
1003 PARA_INFO_LOG("server_socket: %d\n", server_socket);
1004 init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
1005 register_command_task(&s);
1006 s.default_timeout.tv_sec = 0;
1007 s.default_timeout.tv_usec = 999 * 1000;
1008 ret = write(socket_fd, "\0", 1);
1009 if (ret != 1) {
1010 if (ret == 0)
1011 errno = EINVAL;
1012 ret = -ERRNO_TO_PARA_ERROR(errno);
1013 goto out_close;
1014 }
1015 ret = schedule(&s);
1016 sched_shutdown(&s);
1017 close_current_mood();
1018 out_close:
1019 close_afs_tables();
1020 out:
1021 signal_shutdown(signal_task);
1022 free_status_items();
1023 free(current_mop);
1024 free_lpr();
1025 if (ret < 0)
1026 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1027 exit(EXIT_FAILURE);
1028 }
1029
1030 static int com_init_callback(struct afs_callback_arg *aca)
1031 {
1032 uint32_t table_mask = *(uint32_t *)aca->query.data;
1033 int i, ret;
1034
1035 close_afs_tables();
1036 get_database_dir();
1037 for (i = 0; i < NUM_AFS_TABLES; i++) {
1038 struct afs_table *t = &afs_tables[i];
1039
1040 if (!(table_mask & (1 << i)))
1041 continue;
1042 if (!t->create)
1043 continue;
1044 ret = t->create(database_dir);
1045 if (ret < 0) {
1046 para_printf(&aca->pbout, "cannot create table %s\n",
1047 t->name);
1048 goto out;
1049 }
1050 para_printf(&aca->pbout, "successfully created %s table\n",
1051 t->name);
1052 }
1053 ret = open_afs_tables();
1054 if (ret < 0)
1055 para_printf(&aca->pbout, "cannot open afs tables: %s\n",
1056 para_strerror(-ret));
1057 out:
1058 return ret;
1059 }
1060
1061 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1062 {
1063 int i, j, ret;
1064 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1065 struct osl_object query = {.data = &table_mask,
1066 .size = sizeof(table_mask)};
1067 unsigned num_inputs = lls_num_inputs(lpr);
1068
1069 ret = make_database_dir();
1070 if (ret < 0)
1071 return ret;
1072 if (num_inputs > 0) {
1073 table_mask = 0;
1074 for (i = 0; i < num_inputs; i++) {
1075 for (j = 0; j < NUM_AFS_TABLES; j++) {
1076 struct afs_table *t = &afs_tables[j];
1077
1078 if (strcmp(lls_input(i, lpr), t->name))
1079 continue;
1080 table_mask |= (1 << j);
1081 break;
1082 }
1083 if (j == NUM_AFS_TABLES)
1084 return -E_BAD_TABLE_NAME;
1085 }
1086 }
1087 return send_callback_request(com_init_callback, &query,
1088 afs_cb_result_handler, cc);
1089 }
1090 EXPORT_SERVER_CMD_HANDLER(init);
1091
1092 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1093 {
1094 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1095 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1096 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1097 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1098 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1099 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1100 int ret;
1101
1102 if (noopt || lls_opt_given(r_a)) {
1103 ret = send_callback_request(aft_check_callback, NULL,
1104 afs_cb_result_handler, cc);
1105 if (ret < 0)
1106 return ret;
1107 }
1108 if (noopt || lls_opt_given(r_A)) {
1109 ret = send_callback_request(attribute_check_callback, NULL,
1110 afs_cb_result_handler, cc);
1111 if (ret < 0)
1112 return ret;
1113 }
1114 if (noopt || lls_opt_given(r_p)) {
1115 ret = send_callback_request(playlist_check_callback,
1116 NULL, afs_cb_result_handler, cc);
1117 if (ret < 0)
1118 return ret;
1119 }
1120 if (noopt || lls_opt_given(r_m)) {
1121 ret = send_callback_request(mood_check_callback, NULL,
1122 afs_cb_result_handler, cc);
1123 if (ret < 0)
1124 return ret;
1125 }
1126 return 1;
1127 }
1128 EXPORT_SERVER_CMD_HANDLER(check);
1129
1130 /**
1131 * The afs event dispatcher.
1132 *
1133 * \param event Type of the event.
1134 * \param pb May be \p NULL.
1135 * \param data Type depends on \a event.
1136 *
1137 * This function calls each table event handler, passing \a pb and \a data
1138 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1139 * handler returns negative, the loop is aborted.
1140 *
1141 * \return The (negative) error code of the first handler that failed, or non-negative
1142 * if all handlers succeeded.
1143 */
1144 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1145 void *data)
1146 {
1147 int i, ret;
1148
1149 for (i = 0; i < NUM_AFS_TABLES; i++) {
1150 struct afs_table *t = &afs_tables[i];
1151 if (!t->event_handler)
1152 continue;
1153 ret = t->event_handler(event, pb, data);
1154 if (ret < 0) {
1155 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1156 event, para_strerror(-ret));
1157 return ret;
1158 }
1159 }
1160 return 1;
1161 }
1162
1163 /**
1164 * Dummy event handler for the images table.
1165 *
1166 * \param event Unused.
1167 * \param pb Unused.
1168 * \param data Unused.
1169 *
1170 * \return The images table does not honor events, so this handler always
1171 * returns success.
1172 */
1173 __a_const int images_event_handler(__a_unused enum afs_events event,
1174 __a_unused struct para_buffer *pb, __a_unused void *data)
1175 {
1176 return 1;
1177 }
1178
1179 /**
1180 * Dummy event handler for the lyrics table.
1181 *
1182 * \param event Unused.
1183 * \param pb Unused.
1184 * \param data Unused.
1185 *
1186 * \return The lyrics table does not honor events, so this handler always
1187 * returns success.
1188 */
1189 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1190 __a_unused struct para_buffer *pb, __a_unused void *data)
1191 {
1192 return 1;
1193 }