Version 2 moods.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.c Paraslash's audio file selector. */
8
9 #include <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <lopsub.h>
16 #include <arpa/inet.h>
17 #include <sys/un.h>
18 #include <netdb.h>
19 #include <lopsub.h>
20
21 #include "server.lsg.h"
22 #include "server_cmd.lsg.h"
23 #include "para.h"
24 #include "error.h"
25 #include "crypt.h"
26 #include "string.h"
27 #include "afh.h"
28 #include "afs.h"
29 #include "server.h"
30 #include "net.h"
31 #include "ipc.h"
32 #include "list.h"
33 #include "sched.h"
34 #include "fd.h"
35 #include "signal.h"
36 #include "mood.h"
37 #include "sideband.h"
38 #include "command.h"
39
40 /** The osl tables used by afs. \sa \ref blob.c. */
41 enum afs_table_num {
42 /** Contains audio file information. See \ref aft.c. */
43 TBLNUM_AUDIO_FILES,
44 /** The table for the paraslash attributes. See \ref attribute.c. */
45 TBLNUM_ATTRIBUTES,
46 /**
47 * Paraslash's scoring system is based on Gaussian normal
48 * distributions, and the relevant data is stored in the rbtrees of an
49 * osl table containing only volatile columns. See \ref score.c for
50 * details.
51 */
52 TBLNUM_SCORES,
53 /**
54 * A standard blob table containing the mood definitions. For details
55 * see \ref mood.c.
56 */
57 TBLNUM_MOODS,
58 /** A blob table containing lyrics on a per-song basis. */
59 TBLNUM_LYRICS,
60 /** Another blob table for images (for example album cover art). */
61 TBLNUM_IMAGES,
62 /** Yet another blob table for storing standard playlists. */
63 TBLNUM_PLAYLIST,
64 /** How many tables are in use? */
65 NUM_AFS_TABLES
66 };
67
68 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
69 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
70 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
71 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
72 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
73 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
74 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
75 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
76 };
77
78 struct command_task {
79 /** The file descriptor for the local socket. */
80 int fd;
81 /**
82 * Value sent by the command handlers to identify themselves as
83 * children of the running para_server.
84 */
85 uint32_t cookie;
86 /** The associated task structure. */
87 struct task *task;
88 };
89
90 extern int mmd_mutex;
91 extern struct misc_meta_data *mmd;
92
93 static int server_socket;
94 static struct command_task command_task_struct;
95 static struct signal_task *signal_task;
96
97 static enum play_mode current_play_mode;
98 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
99
100 /**
101 * A random number used to "authenticate" the connection.
102 *
103 * para_server picks this number by random before it forks the afs process. The
104 * command handlers know this number as well and write it to the afs socket,
105 * together with the id of the shared memory area which contains the payload of
106 * the afs command. A local process has to know this number to abuse the afs
107 * service provided by the local socket.
108 */
109 extern uint32_t afs_socket_cookie;
110
111 /**
112 * Struct to let command handlers execute a callback in afs context.
113 *
114 * Commands that need to change the state of afs can't change the relevant data
115 * structures directly because commands are executed in a child process, i.e.
116 * they get their own virtual address space.
117 *
118 * This structure is used by \p send_callback_request() (executed from handler
119 * context) in order to let the afs process call the specified function. An
120 * instance of that structure is written to a shared memory area together with
121 * the arguments to the callback function. The identifier of the shared memory
122 * area is written to the command socket.
123 *
124 * The afs process accepts connections on the command socket and reads the
125 * shared memory id, attaches the corresponding area, calls the given handler to
126 * perform the desired action and to optionally compute a result.
127 *
128 * The result and a \p callback_result structure is then written to another
129 * shared memory area. The identifier for that area is written to the handler's
130 * command socket, so that the handler process can read the id, attach the
131 * shared memory area and use the result.
132 *
133 * \sa \ref struct callback_result.
134 */
135 struct callback_query {
136 /** The function to be called. */
137 afs_callback *handler;
138 /** The number of bytes of the query */
139 size_t query_size;
140 };
141
142 /**
143 * Structure embedded in the result of a callback.
144 *
145 * If the callback produced a result, an instance of that structure is embedded
146 * into the shared memory area holding the result, mainly to let the command
147 * handler know the size of the result.
148 *
149 * \sa \ref struct callback_query.
150 */
151 struct callback_result {
152 /** The number of bytes of the result. */
153 size_t result_size;
154 /** The band designator (loglevel for the result). */
155 uint8_t band;
156 };
157
158 static int dispatch_result(int result_shmid, callback_result_handler *handler,
159 void *private_result_data)
160 {
161 struct osl_object result;
162 void *result_shm;
163 /* must attach r/w as result.data might get encrypted in-place. */
164 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
165 struct callback_result *cr = result_shm;
166
167 if (ret < 0) {
168 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
169 return ret;
170 }
171 result.size = cr->result_size;
172 result.data = result_shm + sizeof(*cr);
173 assert(handler);
174 ret = handler(&result, cr->band, private_result_data);
175 ret2 = shm_detach(result_shm);
176 if (ret2 < 0) {
177 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
178 if (ret >= 0)
179 ret = ret2;
180 }
181 return ret;
182 }
183
184 /**
185 * Ask the afs process to call a given function.
186 *
187 * \param f The function to be called.
188 * \param query Pointer to arbitrary data for the callback.
189 * \param result_handler Called for each shm area sent by the callback.
190 * \param private_result_data Passed verbatim to \a result_handler.
191 *
192 * This function creates a socket for communication with the afs process and a
193 * shared memory area (sma) to which the buffer pointed to by \a query is
194 * copied. It then notifies the afs process that the callback function \a f
195 * should be executed by sending the shared memory identifier (shmid) to the
196 * socket.
197 *
198 * If the callback produces a result, it sends any number of shared memory
199 * identifiers back via the socket. For each such identifier received, \a
200 * result_handler is called. The contents of the sma identified by the received
201 * shmid are passed to that function as an osl object. The private_result_data
202 * pointer is passed as the second argument to \a result_handler.
203 *
204 * \return Number of shared memory areas dispatched on success, negative on
205 * errors.
206 */
207 int send_callback_request(afs_callback *f, struct osl_object *query,
208 callback_result_handler *result_handler,
209 void *private_result_data)
210 {
211 struct callback_query *cq;
212 int ret, fd = -1, query_shmid, result_shmid;
213 void *query_shm;
214 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
215 size_t query_shm_size = sizeof(*cq);
216 int dispatch_error = 0, num_dispatched = 0;
217
218 if (query)
219 query_shm_size += query->size;
220 ret = shm_new(query_shm_size);
221 if (ret < 0)
222 return ret;
223 query_shmid = ret;
224 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
225 if (ret < 0)
226 goto out;
227 cq = query_shm;
228 cq->handler = f;
229 cq->query_size = query_shm_size - sizeof(*cq);
230
231 if (query)
232 memcpy(query_shm + sizeof(*cq), query->data, query->size);
233 ret = shm_detach(query_shm);
234 if (ret < 0)
235 goto out;
236
237 *(uint32_t *)buf = afs_socket_cookie;
238 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
239
240 ret = connect_local_socket(OPT_STRING_VAL(AFS_SOCKET));
241 if (ret < 0)
242 goto out;
243 fd = ret;
244 ret = write_all(fd, buf, sizeof(buf));
245 if (ret < 0)
246 goto out;
247 /*
248 * Read all shmids from afs.
249 *
250 * Even if the dispatcher returns an error we _must_ continue to read
251 * shmids from fd so that we can destroy all shared memory areas that
252 * have been created for us by the afs process.
253 */
254 for (;;) {
255 ret = recv_bin_buffer(fd, buf, sizeof(int));
256 if (ret <= 0)
257 goto out;
258 assert(ret == sizeof(int));
259 ret = *(int *) buf;
260 assert(ret > 0);
261 result_shmid = ret;
262 ret = dispatch_result(result_shmid, result_handler,
263 private_result_data);
264 if (ret < 0 && dispatch_error >= 0)
265 dispatch_error = ret;
266 ret = shm_destroy(result_shmid);
267 if (ret < 0)
268 PARA_CRIT_LOG("destroy result failed: %s\n",
269 para_strerror(-ret));
270 num_dispatched++;
271 }
272 out:
273 if (shm_destroy(query_shmid) < 0)
274 PARA_CRIT_LOG("shm destroy error\n");
275 if (fd >= 0)
276 close(fd);
277 if (dispatch_error < 0)
278 return dispatch_error;
279 if (ret < 0)
280 return ret;
281 return num_dispatched;
282 }
283
284 /**
285 * Wrapper for send_callback_request() which passes a lopsub parse result.
286 *
287 * \param f The callback function.
288 * \param cmd Needed for (de-)serialization.
289 * \param lpr Must match cmd.
290 * \param private_result_data Passed to send_callback_request().
291 *
292 * This function serializes the parse result given by the lpr pointer into a
293 * buffer. The buffer is sent as the query to the afs process with the callback
294 * mechanism.
295 *
296 * \return The return value of the underlying call to send_callback_request().
297 */
298 int send_lls_callback_request(afs_callback *f,
299 const struct lls_command * const cmd,
300 struct lls_parse_result *lpr, void *private_result_data)
301 {
302 struct osl_object query;
303 char *buf = NULL;
304 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
305
306 assert(ret >= 0);
307 query.data = buf;
308 ret = send_callback_request(f, &query, afs_cb_result_handler,
309 private_result_data);
310 free(buf);
311 return ret;
312 }
313
314 static int action_if_pattern_matches(struct osl_row *row, void *data)
315 {
316 struct pattern_match_data *pmd = data;
317 struct osl_object name_obj;
318 const char *p, *name;
319 int i, ret;
320
321 ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num,
322 &name_obj));
323 if (ret < 0)
324 return ret;
325 name = (char *)name_obj.data;
326 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
327 return 1;
328 if (lls_num_inputs(pmd->lpr) == 0) {
329 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
330 pmd->num_matches++;
331 return pmd->action(pmd->table, row, name, pmd->data);
332 }
333 }
334 i = pmd->input_skip;
335 for (;;) {
336 if (i >= lls_num_inputs(pmd->lpr))
337 break;
338 p = lls_input(i, pmd->lpr);
339 ret = fnmatch(p, name, pmd->fnmatch_flags);
340 if (ret != FNM_NOMATCH) {
341 if (ret != 0)
342 return -E_FNMATCH;
343 ret = pmd->action(pmd->table, row, name, pmd->data);
344 if (ret >= 0)
345 pmd->num_matches++;
346 return ret;
347
348 }
349 i++;
350 }
351 return 1;
352 }
353
354 /**
355 * Execute the given function for each matching row.
356 *
357 * \param pmd Describes what to match and how.
358 *
359 * \return Standard.
360 */
361 int for_each_matching_row(struct pattern_match_data *pmd)
362 {
363 if (pmd->pm_flags & PM_REVERSE_LOOP)
364 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
365 action_if_pattern_matches));
366 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
367 action_if_pattern_matches));
368 }
369
370 /**
371 * Compare two osl objects of string type.
372 *
373 * \param obj1 Pointer to the first object.
374 * \param obj2 Pointer to the second object.
375 *
376 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
377 * are taken into account.
378 *
379 * \return It returns an integer less than, equal to, or greater than zero if
380 * \a obj1 is found, respectively, to be less than, to match, or be greater than
381 * obj2.
382 *
383 * \sa strcmp(3), strncmp(3).
384 */
385 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
386 {
387 const char *str1 = (const char *)obj1->data;
388 const char *str2 = (const char *)obj2->data;
389 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
390 }
391
392 static int pass_afd(int fd, char *buf, size_t size)
393 {
394 struct msghdr msg = {.msg_iov = NULL};
395 struct cmsghdr *cmsg;
396 char control[255] __a_aligned(8);
397 int ret;
398 struct iovec iov;
399
400 iov.iov_base = buf;
401 iov.iov_len = size;
402
403 msg.msg_iov = &iov;
404 msg.msg_iovlen = 1;
405
406 msg.msg_control = control;
407 msg.msg_controllen = sizeof(control);
408
409 cmsg = CMSG_FIRSTHDR(&msg);
410 cmsg->cmsg_level = SOL_SOCKET;
411 cmsg->cmsg_type = SCM_RIGHTS;
412 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
413 *(int *)CMSG_DATA(cmsg) = fd;
414
415 /* Sum of the length of all control messages in the buffer */
416 msg.msg_controllen = cmsg->cmsg_len;
417 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
418 ret = sendmsg(server_socket, &msg, 0);
419 if (ret < 0) {
420 ret = -ERRNO_TO_PARA_ERROR(errno);
421 return ret;
422 }
423 return 1;
424 }
425
426 /**
427 * Pass the fd of the next audio file to the server process.
428 *
429 * This stores all information for streaming the "best" audio file in a shared
430 * memory area. The id of that area and an open file descriptor for the next
431 * audio file are passed to the server process.
432 *
433 * \return Standard.
434 *
435 * \sa \ref open_and_update_audio_file().
436 */
437 static int open_next_audio_file(void)
438 {
439 struct audio_file_data afd;
440 int ret, shmid;
441 char buf[8];
442
443 ret = open_and_update_audio_file(&afd);
444 if (ret < 0) {
445 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
446 goto no_admissible_files;
447 }
448 shmid = ret;
449 if (!write_ok(server_socket)) {
450 ret = -E_AFS_SOCKET;
451 goto destroy;
452 }
453 *(uint32_t *)buf = NEXT_AUDIO_FILE;
454 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
455 ret = pass_afd(afd.fd, buf, 8);
456 close(afd.fd);
457 if (ret >= 0)
458 return ret;
459 destroy:
460 shm_destroy(shmid);
461 return ret;
462 no_admissible_files:
463 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
464 *(uint32_t *)(buf + 4) = (uint32_t)0;
465 return write_all(server_socket, buf, 8);
466 }
467
468 /* Never fails if arg == NULL */
469 static int activate_mood_or_playlist(const char *arg, int *num_admissible,
470 char **errmsg)
471 {
472 enum play_mode mode;
473 int ret;
474
475 if (!arg) {
476 ret = change_current_mood(NULL, NULL); /* always successful */
477 mode = PLAY_MODE_MOOD;
478 } else {
479 if (!strncmp(arg, "p/", 2)) {
480 ret = playlist_open(arg + 2);
481 if (ret < 0 && errmsg)
482 *errmsg = make_message( "could not open %s",
483 arg);
484 mode = PLAY_MODE_PLAYLIST;
485 } else if (!strncmp(arg, "m/", 2)) {
486 ret = change_current_mood(arg + 2, errmsg);
487 mode = PLAY_MODE_MOOD;
488 } else {
489 if (errmsg)
490 *errmsg = make_message("%s: parse error", arg);
491 return -ERRNO_TO_PARA_ERROR(EINVAL);
492 }
493 if (ret < 0)
494 return ret;
495 }
496 if (num_admissible)
497 *num_admissible = ret;
498 current_play_mode = mode;
499 if (arg != current_mop) {
500 free(current_mop);
501 if (arg) {
502 current_mop = para_strdup(arg);
503 mutex_lock(mmd_mutex);
504 strncpy(mmd->afs_mode_string, arg,
505 sizeof(mmd->afs_mode_string));
506 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
507 mmd->events++;
508 mutex_unlock(mmd_mutex);
509 } else {
510 mutex_lock(mmd_mutex);
511 strcpy(mmd->afs_mode_string, "dummy");
512 mmd->events++;
513 mutex_unlock(mmd_mutex);
514 current_mop = NULL;
515 }
516 }
517 return 1;
518 }
519
520 /**
521 * Result handler for sending data to the para_client process.
522 *
523 * \param result The data to be sent.
524 * \param band The band designator.
525 * \param private Pointer to the command context.
526 *
527 * \return The return value of the underlying call to \ref command.c::send_sb.
528 *
529 * \sa \ref callback_result_handler, \ref command.c::send_sb.
530 */
531 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
532 void *private)
533 {
534 struct command_context *cc = private;
535
536 assert(cc);
537 switch (band) {
538 case SBD_OUTPUT:
539 case SBD_DEBUG_LOG:
540 case SBD_INFO_LOG:
541 case SBD_NOTICE_LOG:
542 case SBD_WARNING_LOG:
543 case SBD_ERROR_LOG:
544 case SBD_CRIT_LOG:
545 case SBD_EMERG_LOG:
546 assert(result->size > 0);
547 return send_sb(&cc->scc, result->data, result->size, band, true);
548 case SBD_AFS_CB_FAILURE:
549 return *(int *)(result->data);
550 default:
551 return -E_BAD_BAND;
552 }
553 }
554
555 static void flush_and_free_pb(struct para_buffer *pb)
556 {
557 int ret;
558 struct afs_max_size_handler_data *amshd = pb->private_data;
559
560 if (pb->buf && pb->size > 0) {
561 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
562 pb->offset);
563 if (ret < 0)
564 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
565 }
566 free(pb->buf);
567 }
568
569 static int com_select_callback(struct afs_callback_arg *aca)
570 {
571 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
572 const char *arg;
573 int num_admissible, ret;
574 char *errmsg;
575
576 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
577 assert(ret >= 0);
578 arg = lls_input(0, aca->lpr);
579 ret = clear_score_table();
580 if (ret < 0) {
581 para_printf(&aca->pbout, "could not clear score table\n");
582 goto free_lpr;
583 }
584 if (current_play_mode == PLAY_MODE_MOOD)
585 close_current_mood();
586 else
587 playlist_close();
588 ret = activate_mood_or_playlist(arg, &num_admissible, &errmsg);
589 if (ret >= 0)
590 goto out;
591 /* ignore subsequent errors (but log them) */
592 para_printf(&aca->pbout, "%s\n", errmsg);
593 free(errmsg);
594 para_printf(&aca->pbout, "could not activate %s\n", arg);
595 if (current_mop && strcmp(current_mop, arg) != 0) {
596 int ret2;
597 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
598 ret2 = activate_mood_or_playlist(current_mop, &num_admissible,
599 &errmsg);
600 if (ret2 >= 0)
601 goto out;
602 para_printf(&aca->pbout, "%s\n", errmsg);
603 free(errmsg);
604 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
605 current_mop, para_strerror(-ret2));
606 }
607 para_printf(&aca->pbout, "activating dummy mood\n");
608 activate_mood_or_playlist(NULL, &num_admissible, NULL);
609 out:
610 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
611 current_mop? current_mop : "dummy mood", num_admissible);
612 free_lpr:
613 lls_free_parse_result(aca->lpr, cmd);
614 return ret;
615 }
616
617 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
618 {
619 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
620 char *errctx;
621 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
622
623 if (ret < 0) {
624 send_errctx(cc, errctx);
625 return ret;
626 }
627 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
628 }
629 EXPORT_SERVER_CMD_HANDLER(select);
630
631 static void init_admissible_files(const char *arg)
632 {
633 int ret = activate_mood_or_playlist(arg, NULL, NULL);
634 if (ret < 0) {
635 assert(arg);
636 PARA_WARNING_LOG("could not activate %s: %s\n", arg,
637 para_strerror(-ret));
638 activate_mood_or_playlist(NULL, NULL, NULL);
639 }
640 }
641
642 static int setup_command_socket_or_die(void)
643 {
644 int ret, socket_fd;
645 const char *socket_name = OPT_STRING_VAL(AFS_SOCKET);
646
647 unlink(socket_name);
648 ret = create_local_socket(socket_name);
649 if (ret < 0) {
650 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
651 exit(EXIT_FAILURE);
652 }
653 socket_fd = ret;
654 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
655 socket_fd);
656 return socket_fd;
657 }
658
659 static void close_afs_tables(void)
660 {
661 int i;
662 PARA_NOTICE_LOG("closing afs_tables\n");
663 for (i = 0; i < NUM_AFS_TABLES; i++)
664 afs_tables[i].close();
665 }
666
667 static char *database_dir;
668
669 static void get_database_dir(void)
670 {
671 if (!database_dir) {
672 if (OPT_GIVEN(AFS_DATABASE_DIR))
673 database_dir = para_strdup(OPT_STRING_VAL(AFS_DATABASE_DIR));
674 else {
675 char *home = para_homedir();
676 database_dir = make_message(
677 "%s/.paraslash/afs_database-0.4", home);
678 free(home);
679 }
680 }
681 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
682 }
683
684 static int make_database_dir(void)
685 {
686 int ret;
687
688 get_database_dir();
689 ret = para_mkdir(database_dir, 0777);
690 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
691 return 1;
692 return ret;
693 }
694
695 static int open_afs_tables(void)
696 {
697 int i, ret;
698
699 get_database_dir();
700 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
701 database_dir);
702 for (i = 0; i < NUM_AFS_TABLES; i++) {
703 ret = afs_tables[i].open(database_dir);
704 if (ret >= 0)
705 continue;
706 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
707 para_strerror(-ret));
708 break;
709 }
710 if (ret >= 0)
711 return ret;
712 while (i)
713 afs_tables[--i].close();
714 return ret;
715 }
716
717 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
718 {
719 int signum, ret;
720
721 if (getppid() == 1) {
722 PARA_EMERG_LOG("para_server died\n");
723 goto shutdown;
724 }
725 signum = para_next_signal(&s->rfds);
726 if (signum == 0)
727 return 0;
728 if (signum == SIGHUP) {
729 close_afs_tables();
730 parse_config_or_die(1);
731 ret = open_afs_tables();
732 if (ret < 0)
733 return ret;
734 init_admissible_files(current_mop);
735 return 0;
736 }
737 PARA_EMERG_LOG("terminating on signal %d\n", signum);
738 shutdown:
739 task_notify_all(s, E_AFS_SIGNAL);
740 return -E_AFS_SIGNAL;
741 }
742
743 static void register_signal_task(struct sched *s)
744 {
745 para_sigaction(SIGPIPE, SIG_IGN);
746 signal_task = signal_init_or_die();
747 para_install_sighandler(SIGINT);
748 para_install_sighandler(SIGTERM);
749 para_install_sighandler(SIGHUP);
750
751 signal_task->task = task_register(&(struct task_info) {
752 .name = "signal",
753 .pre_select = signal_pre_select,
754 .post_select = afs_signal_post_select,
755 .context = signal_task,
756
757 }, s);
758 }
759
760 static struct list_head afs_client_list;
761
762 /** Describes one connected afs client. */
763 struct afs_client {
764 /** Position in the afs client list. */
765 struct list_head node;
766 /** The socket file descriptor for this client. */
767 int fd;
768 /** The time the client connected. */
769 struct timeval connect_time;
770 };
771
772 static void command_pre_select(struct sched *s, void *context)
773 {
774 struct command_task *ct = context;
775 struct afs_client *client;
776
777 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
778 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
779 list_for_each_entry(client, &afs_client_list, node)
780 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
781 }
782
783 /**
784 * Send data as shared memory to a file descriptor.
785 *
786 * \param fd File descriptor to send the shmid to.
787 * \param band The band designator for this data.
788 * \param buf The buffer holding the data to be sent.
789 * \param size The size of \a buf.
790 *
791 * This function creates a shared memory area large enough to hold
792 * the content given by \a buf and \a size and sends the identifier
793 * of this area to the file descriptor \a fd.
794 *
795 * It is called by the AFS max_size handler as well as directly by the AFS
796 * command callbacks to send command output to the command handlers.
797 *
798 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
799 * and positive on success.
800 */
801 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
802 {
803 int ret, shmid;
804 void *shm;
805 struct callback_result *cr;
806
807 if (size == 0)
808 assert(band != SBD_OUTPUT);
809 ret = shm_new(size + sizeof(*cr));
810 if (ret < 0)
811 return ret;
812 shmid = ret;
813 ret = shm_attach(shmid, ATTACH_RW, &shm);
814 if (ret < 0)
815 goto err;
816 cr = shm;
817 cr->result_size = size;
818 cr->band = band;
819 if (size > 0)
820 memcpy(shm + sizeof(*cr), buf, size);
821 ret = shm_detach(shm);
822 if (ret < 0)
823 goto err;
824 ret = write_all(fd, (char *)&shmid, sizeof(int));
825 if (ret >= 0)
826 return ret;
827 err:
828 if (shm_destroy(shmid) < 0)
829 PARA_ERROR_LOG("destroy result failed\n");
830 return ret;
831 }
832
833 static int call_callback(int fd, int query_shmid)
834 {
835 void *query_shm;
836 struct callback_query *cq;
837 int ret, ret2;
838 struct afs_callback_arg aca = {.fd = fd};
839
840 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
841 if (ret < 0)
842 return ret;
843 cq = query_shm;
844 aca.query.data = (char *)query_shm + sizeof(*cq);
845 aca.query.size = cq->query_size;
846 aca.pbout.max_size = shm_get_shmmax();
847 aca.pbout.max_size_handler = afs_max_size_handler;
848 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
849 .fd = fd,
850 .band = SBD_OUTPUT
851 };
852 ret = cq->handler(&aca);
853 ret2 = shm_detach(query_shm);
854 if (ret2 < 0) {
855 if (ret < 0) /* ignore (but log) detach error */
856 PARA_ERROR_LOG("could not detach sma: %s\n",
857 para_strerror(-ret2));
858 else
859 ret = ret2;
860 }
861 flush_and_free_pb(&aca.pbout);
862 if (ret < 0) {
863 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
864 (const char *)&ret, sizeof(ret));
865 if (ret2 < 0)
866 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
867 para_strerror(-ret));
868 }
869 return ret;
870 }
871
872 static int execute_server_command(fd_set *rfds)
873 {
874 char buf[8];
875 size_t n;
876 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
877
878 if (ret < 0 || n == 0)
879 return ret;
880 buf[n] = '\0';
881 if (strcmp(buf, "new"))
882 return -ERRNO_TO_PARA_ERROR(EINVAL);
883 return open_next_audio_file();
884 }
885
886 /* returns 0 if no data available, 1 else */
887 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
888 {
889 uint32_t cookie;
890 int query_shmid;
891 char buf[sizeof(cookie) + sizeof(query_shmid)];
892 size_t n;
893 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
894
895 if (ret < 0)
896 goto err;
897 if (n == 0)
898 return 0;
899 if (n != sizeof(buf)) {
900 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
901 ret, (long unsigned) sizeof(buf));
902 return 1;
903 }
904 cookie = *(uint32_t *)buf;
905 if (cookie != expected_cookie) {
906 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
907 (unsigned)cookie, (unsigned)expected_cookie);
908 return 1;
909 }
910 query_shmid = *(int *)(buf + sizeof(cookie));
911 if (query_shmid < 0) {
912 PARA_WARNING_LOG("received invalid query shmid %d)\n",
913 query_shmid);
914 return 1;
915 }
916 ret = call_callback(fd, query_shmid);
917 if (ret >= 0)
918 return 1;
919 err:
920 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
921 return 1;
922 }
923
924 /** Shutdown connection if query has not arrived until this many seconds. */
925 #define AFS_CLIENT_TIMEOUT 3
926
927 static int command_post_select(struct sched *s, void *context)
928 {
929 struct command_task *ct = context;
930 struct sockaddr_un unix_addr;
931 struct afs_client *client, *tmp;
932 int fd, ret;
933
934 ret = task_get_notification(ct->task);
935 if (ret < 0)
936 return ret;
937 ret = execute_server_command(&s->rfds);
938 if (ret < 0) {
939 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
940 task_notify_all(s, -ret);
941 return ret;
942 }
943 /* Check the list of connected clients. */
944 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
945 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
946 if (ret == 0) { /* prevent bogus connection flooding */
947 struct timeval diff;
948 tv_diff(now, &client->connect_time, &diff);
949 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
950 continue;
951 PARA_WARNING_LOG("connection timeout\n");
952 }
953 close(client->fd);
954 list_del(&client->node);
955 free(client);
956 }
957 /* Accept connections on the local socket. */
958 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
959 if (ret < 0)
960 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
961 if (ret <= 0)
962 return 0;
963 ret = mark_fd_nonblocking(fd);
964 if (ret < 0) {
965 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
966 close(fd);
967 return 0;
968 }
969 client = para_malloc(sizeof(*client));
970 client->fd = fd;
971 client->connect_time = *now;
972 para_list_add(&client->node, &afs_client_list);
973 return 0;
974 }
975
976 static void register_command_task(uint32_t cookie, struct sched *s)
977 {
978 struct command_task *ct = &command_task_struct;
979 ct->fd = setup_command_socket_or_die();
980 ct->cookie = cookie;
981
982 ct->task = task_register(&(struct task_info) {
983 .name = "afs command",
984 .pre_select = command_pre_select,
985 .post_select = command_post_select,
986 .context = ct,
987 }, s);
988 }
989
990 /**
991 * Initialize the audio file selector process.
992 *
993 * \param cookie The value used for "authentication".
994 * \param socket_fd File descriptor used for communication with the server.
995 */
996 __noreturn void afs_init(uint32_t cookie, int socket_fd)
997 {
998 static struct sched s;
999 int i, ret;
1000
1001 register_signal_task(&s);
1002 INIT_LIST_HEAD(&afs_client_list);
1003 for (i = 0; i < NUM_AFS_TABLES; i++)
1004 afs_tables[i].init(&afs_tables[i]);
1005 ret = open_afs_tables();
1006 if (ret < 0)
1007 goto out;
1008 server_socket = socket_fd;
1009 ret = mark_fd_nonblocking(server_socket);
1010 if (ret < 0)
1011 goto out_close;
1012 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1013 server_socket, (unsigned) cookie);
1014 init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
1015 register_command_task(cookie, &s);
1016 s.default_timeout.tv_sec = 0;
1017 s.default_timeout.tv_usec = 999 * 1000;
1018 ret = write(socket_fd, "\0", 1);
1019 if (ret != 1) {
1020 if (ret == 0)
1021 errno = EINVAL;
1022 ret = -ERRNO_TO_PARA_ERROR(errno);
1023 goto out_close;
1024 }
1025 ret = schedule(&s);
1026 sched_shutdown(&s);
1027 out_close:
1028 close_afs_tables();
1029 out:
1030 if (ret < 0)
1031 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1032 exit(EXIT_FAILURE);
1033 }
1034
1035 static int com_init_callback(struct afs_callback_arg *aca)
1036 {
1037 uint32_t table_mask = *(uint32_t *)aca->query.data;
1038 int i, ret;
1039
1040 close_afs_tables();
1041 for (i = 0; i < NUM_AFS_TABLES; i++) {
1042 struct afs_table *t = &afs_tables[i];
1043
1044 if (!(table_mask & (1 << i)))
1045 continue;
1046 if (!t->create)
1047 continue;
1048 ret = t->create(database_dir);
1049 if (ret < 0) {
1050 para_printf(&aca->pbout, "cannot create table %s\n",
1051 t->name);
1052 goto out;
1053 }
1054 para_printf(&aca->pbout, "successfully created %s table\n",
1055 t->name);
1056 }
1057 ret = open_afs_tables();
1058 if (ret < 0)
1059 para_printf(&aca->pbout, "cannot open afs tables\n");
1060 out:
1061 return ret;
1062 }
1063
1064 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1065 {
1066 int i, j, ret;
1067 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1068 struct osl_object query = {.data = &table_mask,
1069 .size = sizeof(table_mask)};
1070 unsigned num_inputs = lls_num_inputs(lpr);
1071
1072 ret = make_database_dir();
1073 if (ret < 0)
1074 return ret;
1075 if (num_inputs > 0) {
1076 table_mask = 0;
1077 for (i = 0; i < num_inputs; i++) {
1078 for (j = 0; j < NUM_AFS_TABLES; j++) {
1079 struct afs_table *t = &afs_tables[j];
1080
1081 if (strcmp(lls_input(i, lpr), t->name))
1082 continue;
1083 table_mask |= (1 << j);
1084 break;
1085 }
1086 if (j == NUM_AFS_TABLES)
1087 return -E_BAD_TABLE_NAME;
1088 }
1089 }
1090 return send_callback_request(com_init_callback, &query,
1091 afs_cb_result_handler, cc);
1092 }
1093 EXPORT_SERVER_CMD_HANDLER(init);
1094
1095 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1096 {
1097 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1098 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1099 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1100 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1101 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1102 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1103 int ret;
1104
1105 if (noopt || lls_opt_given(r_a)) {
1106 ret = send_callback_request(aft_check_callback, NULL,
1107 afs_cb_result_handler, cc);
1108 if (ret < 0)
1109 return ret;
1110 }
1111 if (noopt || lls_opt_given(r_A)) {
1112 ret = send_callback_request(attribute_check_callback, NULL,
1113 afs_cb_result_handler, cc);
1114 if (ret < 0)
1115 return ret;
1116 }
1117 if (noopt || lls_opt_given(r_p)) {
1118 ret = send_callback_request(playlist_check_callback,
1119 NULL, afs_cb_result_handler, cc);
1120 if (ret < 0)
1121 return ret;
1122 }
1123 if (noopt || lls_opt_given(r_m)) {
1124 ret = send_callback_request(mood_check_callback, NULL,
1125 afs_cb_result_handler, cc);
1126 if (ret < 0)
1127 return ret;
1128 }
1129 return 1;
1130 }
1131 EXPORT_SERVER_CMD_HANDLER(check);
1132
1133 /**
1134 * The afs event dispatcher.
1135 *
1136 * \param event Type of the event.
1137 * \param pb May be \p NULL.
1138 * \param data Type depends on \a event.
1139 *
1140 * This function calls each table event handler, passing \a pb and \a data
1141 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1142 * handler returns negative, the loop is aborted.
1143 *
1144 * \return The (negative) error code of the first handler that failed, or non-negative
1145 * if all handlers succeeded.
1146 */
1147 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1148 void *data)
1149 {
1150 int i, ret;
1151
1152 for (i = 0; i < NUM_AFS_TABLES; i++) {
1153 struct afs_table *t = &afs_tables[i];
1154 if (!t->event_handler)
1155 continue;
1156 ret = t->event_handler(event, pb, data);
1157 if (ret < 0) {
1158 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1159 event, para_strerror(-ret));
1160 return ret;
1161 }
1162 }
1163 return 1;
1164 }
1165
1166 /**
1167 * Dummy event handler for the images table.
1168 *
1169 * \param event Unused.
1170 * \param pb Unused.
1171 * \param data Unused.
1172 *
1173 * \return The images table does not honor events, so this handler always
1174 * returns success.
1175 */
1176 __a_const int images_event_handler(__a_unused enum afs_events event,
1177 __a_unused struct para_buffer *pb, __a_unused void *data)
1178 {
1179 return 1;
1180 }
1181
1182 /**
1183 * Dummy event handler for the lyrics table.
1184 *
1185 * \param event Unused.
1186 * \param pb Unused.
1187 * \param data Unused.
1188 *
1189 * \return The lyrics table does not honor events, so this handler always
1190 * returns success.
1191 */
1192 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1193 __a_unused struct para_buffer *pb, __a_unused void *data)
1194 {
1195 return 1;
1196 }