afs: Remove unused call_callback helpers.
[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_cmd.lsg.h"
22 #include "server.cmdline.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 blob.c. */
41 enum afs_table_num {
42 /** Contains audio file information. See aft.c. */
43 TBLNUM_AUDIO_FILES,
44 /** The table for the paraslash attributes. See 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 score.c for
50 * details.
51 */
52 TBLNUM_SCORES,
53 /**
54 * A standard blob table containing the mood definitions. For details
55 * see 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 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 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 errors.
205 *
206 * \sa send_option_arg_callback_request(), send_standard_callback_request().
207 */
208 int send_callback_request(afs_callback *f, struct osl_object *query,
209 callback_result_handler *result_handler,
210 void *private_result_data)
211 {
212 struct callback_query *cq;
213 int ret, fd = -1, query_shmid, result_shmid;
214 void *query_shm;
215 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
216 size_t query_shm_size = sizeof(*cq);
217 int dispatch_error = 0, num_dispatched = 0;
218
219 if (query)
220 query_shm_size += query->size;
221 ret = shm_new(query_shm_size);
222 if (ret < 0)
223 return ret;
224 query_shmid = ret;
225 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
226 if (ret < 0)
227 goto out;
228 cq = query_shm;
229 cq->handler = f;
230 cq->query_size = query_shm_size - sizeof(*cq);
231
232 if (query)
233 memcpy(query_shm + sizeof(*cq), query->data, query->size);
234 ret = shm_detach(query_shm);
235 if (ret < 0)
236 goto out;
237
238 *(uint32_t *)buf = afs_socket_cookie;
239 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
240
241 ret = connect_local_socket(conf.afs_socket_arg);
242 if (ret < 0)
243 goto out;
244 fd = ret;
245 ret = write_all(fd, buf, sizeof(buf));
246 if (ret < 0)
247 goto out;
248 /*
249 * Read all shmids from afs.
250 *
251 * Even if the dispatcher returns an error we _must_ continue to read
252 * shmids from fd so that we can destroy all shared memory areas that
253 * have been created for us by the afs process.
254 */
255 for (;;) {
256 ret = recv_bin_buffer(fd, buf, sizeof(int));
257 if (ret <= 0)
258 goto out;
259 assert(ret == sizeof(int));
260 ret = *(int *) buf;
261 assert(ret > 0);
262 result_shmid = ret;
263 ret = dispatch_result(result_shmid, result_handler,
264 private_result_data);
265 if (ret < 0 && dispatch_error >= 0)
266 dispatch_error = ret;
267 ret = shm_destroy(result_shmid);
268 if (ret < 0)
269 PARA_CRIT_LOG("destroy result failed: %s\n",
270 para_strerror(-ret));
271 num_dispatched++;
272 }
273 out:
274 if (shm_destroy(query_shmid) < 0)
275 PARA_CRIT_LOG("shm destroy error\n");
276 if (fd >= 0)
277 close(fd);
278 if (dispatch_error < 0)
279 return dispatch_error;
280 if (ret < 0)
281 return ret;
282 return num_dispatched;
283 }
284
285 /**
286 * Wrapper for send_callback_request() which passes a lopsub parse result.
287 *
288 * \param f The callback function.
289 * \param cmd Needed for (de-)serialization.
290 * \param lpr Must match cmd.
291 * \param private_result_data Passed to send_callback_request().
292 *
293 * This function serializes the parse result given by the lpr pointer into a
294 * buffer. The buffer is sent as the query to the afs process with the callback
295 * mechanism.
296 *
297 * \return The return value of the underlying call to send_callback_request().
298 */
299 int send_lls_callback_request(afs_callback *f,
300 const struct lls_command * const cmd,
301 struct lls_parse_result *lpr, void *private_result_data)
302 {
303 struct osl_object query;
304 char *buf = NULL;
305 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
306
307 assert(ret >= 0);
308 query.data = buf;
309 ret = send_callback_request(f, &query, afs_cb_result_handler,
310 private_result_data);
311 free(buf);
312 return ret;
313 }
314
315 static int action_if_pattern_matches(struct osl_row *row, void *data)
316 {
317 struct pattern_match_data *pmd = data;
318 struct osl_object name_obj;
319 const char *p, *name;
320 int i, ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
321 const char *pattern_txt = (const char *)pmd->patterns.data;
322
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 ((pmd->lpr && lls_num_inputs(pmd->lpr) == 0) || pmd->patterns.size == 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 p = pattern_txt;
335 i = pmd->input_skip;
336 for (;;) {
337 if (pmd->lpr) {
338 if (i >= lls_num_inputs(pmd->lpr))
339 break;
340 p = lls_input(i, pmd->lpr);
341 } else {
342 if (p >= pattern_txt + pmd->patterns.size)
343 break;
344 }
345 ret = fnmatch(p, name, pmd->fnmatch_flags);
346 if (ret != FNM_NOMATCH) {
347 if (ret != 0)
348 return -E_FNMATCH;
349 ret = pmd->action(pmd->table, row, name, pmd->data);
350 if (ret >= 0)
351 pmd->num_matches++;
352 return ret;
353
354 }
355 if (pmd->lpr)
356 i++;
357 else
358 p += strlen(p) + 1;
359 }
360 return 1;
361 }
362
363 /**
364 * Execute the given function for each matching row.
365 *
366 * \param pmd Describes what to match and how.
367 *
368 * \return Standard.
369 */
370 int for_each_matching_row(struct pattern_match_data *pmd)
371 {
372 if (pmd->pm_flags & PM_REVERSE_LOOP)
373 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
374 action_if_pattern_matches));
375 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
376 action_if_pattern_matches));
377 }
378
379 /**
380 * Compare two osl objects of string type.
381 *
382 * \param obj1 Pointer to the first object.
383 * \param obj2 Pointer to the second object.
384 *
385 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
386 * are taken into account.
387 *
388 * \return It returns an integer less than, equal to, or greater than zero if
389 * \a obj1 is found, respectively, to be less than, to match, or be greater than
390 * obj2.
391 *
392 * \sa strcmp(3), strncmp(3), osl_compare_func.
393 */
394 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
395 {
396 const char *str1 = (const char *)obj1->data;
397 const char *str2 = (const char *)obj2->data;
398 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
399 }
400
401 static int pass_afd(int fd, char *buf, size_t size)
402 {
403 struct msghdr msg = {.msg_iov = NULL};
404 struct cmsghdr *cmsg;
405 char control[255] __a_aligned(8);
406 int ret;
407 struct iovec iov;
408
409 iov.iov_base = buf;
410 iov.iov_len = size;
411
412 msg.msg_iov = &iov;
413 msg.msg_iovlen = 1;
414
415 msg.msg_control = control;
416 msg.msg_controllen = sizeof(control);
417
418 cmsg = CMSG_FIRSTHDR(&msg);
419 cmsg->cmsg_level = SOL_SOCKET;
420 cmsg->cmsg_type = SCM_RIGHTS;
421 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
422 *(int *)CMSG_DATA(cmsg) = fd;
423
424 /* Sum of the length of all control messages in the buffer */
425 msg.msg_controllen = cmsg->cmsg_len;
426 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
427 ret = sendmsg(server_socket, &msg, 0);
428 if (ret < 0) {
429 ret = -ERRNO_TO_PARA_ERROR(errno);
430 return ret;
431 }
432 return 1;
433 }
434
435 /**
436 * Pass the fd of the next audio file to the server process.
437 *
438 * This stores all information for streaming the "best" audio file in a shared
439 * memory area. The id of that area and an open file descriptor for the next
440 * audio file are passed to the server process.
441 *
442 * \return Standard.
443 *
444 * \sa open_and_update_audio_file().
445 */
446 static int open_next_audio_file(void)
447 {
448 struct audio_file_data afd;
449 int ret, shmid;
450 char buf[8];
451
452 ret = open_and_update_audio_file(&afd);
453 if (ret < 0) {
454 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
455 goto no_admissible_files;
456 }
457 shmid = ret;
458 if (!write_ok(server_socket)) {
459 ret = -E_AFS_SOCKET;
460 goto destroy;
461 }
462 *(uint32_t *)buf = NEXT_AUDIO_FILE;
463 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
464 ret = pass_afd(afd.fd, buf, 8);
465 close(afd.fd);
466 if (ret >= 0)
467 return ret;
468 destroy:
469 shm_destroy(shmid);
470 return ret;
471 no_admissible_files:
472 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
473 *(uint32_t *)(buf + 4) = (uint32_t)0;
474 return write_all(server_socket, buf, 8);
475 }
476
477 /* Never fails if arg == NULL */
478 static int activate_mood_or_playlist(const char *arg, int *num_admissible)
479 {
480 enum play_mode mode;
481 int ret;
482
483 if (!arg) {
484 ret = change_current_mood(NULL); /* always successful */
485 mode = PLAY_MODE_MOOD;
486 } else {
487 if (!strncmp(arg, "p/", 2)) {
488 ret = playlist_open(arg + 2);
489 mode = PLAY_MODE_PLAYLIST;
490 } else if (!strncmp(arg, "m/", 2)) {
491 ret = change_current_mood(arg + 2);
492 mode = PLAY_MODE_MOOD;
493 } else
494 return -E_AFS_SYNTAX;
495 if (ret < 0)
496 return ret;
497 }
498 if (num_admissible)
499 *num_admissible = ret;
500 current_play_mode = mode;
501 if (arg != current_mop) {
502 free(current_mop);
503 if (arg) {
504 current_mop = para_strdup(arg);
505 mutex_lock(mmd_mutex);
506 strncpy(mmd->afs_mode_string, arg,
507 sizeof(mmd->afs_mode_string));
508 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
509 mutex_unlock(mmd_mutex);
510 } else {
511 mutex_lock(mmd_mutex);
512 strcpy(mmd->afs_mode_string, "dummy");
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
575 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
576 assert(ret >= 0);
577 arg = lls_input(0, aca->lpr);
578 ret = clear_score_table();
579 if (ret < 0) {
580 para_printf(&aca->pbout, "could not clear score table\n");
581 goto free_lpr;
582 }
583 if (current_play_mode == PLAY_MODE_MOOD)
584 close_current_mood();
585 else
586 playlist_close();
587 ret = activate_mood_or_playlist(arg, &num_admissible);
588 if (ret >= 0)
589 goto out;
590 /* ignore subsequent errors (but log them) */
591 para_printf(&aca->pbout, "could not activate %s\n", arg);
592 if (current_mop) {
593 int ret2;
594 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
595 ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
596 if (ret2 >= 0)
597 goto out;
598 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
599 current_mop, para_strerror(-ret2));
600 }
601 para_printf(&aca->pbout, "activating dummy mood\n");
602 activate_mood_or_playlist(NULL, &num_admissible);
603 out:
604 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
605 current_mop? current_mop : "dummy mood", num_admissible);
606 free_lpr:
607 lls_free_parse_result(aca->lpr, cmd);
608 return ret;
609 }
610
611 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
612 {
613 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
614 char *errctx;
615 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
616
617 if (ret < 0) {
618 send_errctx(cc, errctx);
619 return ret;
620 }
621 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
622 }
623 EXPORT_SERVER_CMD_HANDLER(select);
624
625 static void init_admissible_files(char *arg)
626 {
627 if (activate_mood_or_playlist(arg, NULL) < 0)
628 activate_mood_or_playlist(NULL, NULL); /* always successful */
629 }
630
631 static int setup_command_socket_or_die(void)
632 {
633 int ret, socket_fd;
634 char *socket_name = conf.afs_socket_arg;
635
636 unlink(socket_name);
637 ret = create_local_socket(socket_name, 0);
638 if (ret < 0) {
639 ret = create_local_socket(socket_name,
640 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IROTH);
641 if (ret < 0) {
642 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
643 socket_name);
644 exit(EXIT_FAILURE);
645 }
646 }
647 socket_fd = ret;
648 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
649 socket_fd);
650 return socket_fd;
651 }
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 }
660
661 static char *database_dir;
662
663 static void get_database_dir(void)
664 {
665 if (!database_dir) {
666 if (conf.afs_database_dir_given)
667 database_dir = para_strdup(conf.afs_database_dir_arg);
668 else {
669 char *home = para_homedir();
670 database_dir = make_message(
671 "%s/.paraslash/afs_database-0.4", 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("%s init: %s\n", afs_tables[i].name,
701 para_strerror(-ret));
702 break;
703 }
704 if (ret >= 0)
705 return ret;
706 while (i)
707 afs_tables[--i].close();
708 return ret;
709 }
710
711 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
712 {
713 int signum, ret;
714
715 if (getppid() == 1) {
716 PARA_EMERG_LOG("para_server died\n");
717 goto shutdown;
718 }
719 signum = para_next_signal(&s->rfds);
720 if (signum == 0)
721 return 0;
722 if (signum == SIGHUP) {
723 close_afs_tables();
724 parse_config_or_die(1);
725 ret = open_afs_tables();
726 if (ret < 0)
727 return ret;
728 init_admissible_files(current_mop);
729 return 0;
730 }
731 PARA_EMERG_LOG("terminating on signal %d\n", signum);
732 shutdown:
733 task_notify_all(s, E_AFS_SIGNAL);
734 return -E_AFS_SIGNAL;
735 }
736
737 static void register_signal_task(struct sched *s)
738 {
739 para_sigaction(SIGPIPE, SIG_IGN);
740 signal_task = signal_init_or_die();
741 para_install_sighandler(SIGINT);
742 para_install_sighandler(SIGTERM);
743 para_install_sighandler(SIGHUP);
744
745 signal_task->task = task_register(&(struct task_info) {
746 .name = "signal",
747 .pre_select = signal_pre_select,
748 .post_select = afs_signal_post_select,
749 .context = signal_task,
750
751 }, s);
752 }
753
754 static struct list_head afs_client_list;
755
756 /** Describes one connected afs client. */
757 struct afs_client {
758 /** Position in the afs client list. */
759 struct list_head node;
760 /** The socket file descriptor for this client. */
761 int fd;
762 /** The time the client connected. */
763 struct timeval connect_time;
764 };
765
766 static void command_pre_select(struct sched *s, void *context)
767 {
768 struct command_task *ct = context;
769 struct afs_client *client;
770
771 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
772 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
773 list_for_each_entry(client, &afs_client_list, node)
774 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
775 }
776
777 /**
778 * Send data as shared memory to a file descriptor.
779 *
780 * \param fd File descriptor to send the shmid to.
781 * \param band The band designator for this data.
782 * \param buf The buffer holding the data to be sent.
783 * \param size The size of \a buf.
784 *
785 * This function creates a shared memory area large enough to hold
786 * the content given by \a buf and \a size and sends the identifier
787 * of this area to the file descriptor \a fd.
788 *
789 * It is called by the AFS max_size handler as well as directly by the AFS
790 * command callbacks to send command output to the command handlers.
791 *
792 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
793 * and positive on success.
794 */
795 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
796 {
797 int ret, shmid;
798 void *shm;
799 struct callback_result *cr;
800
801 if (size == 0)
802 assert(band != SBD_OUTPUT);
803 ret = shm_new(size + sizeof(*cr));
804 if (ret < 0)
805 return ret;
806 shmid = ret;
807 ret = shm_attach(shmid, ATTACH_RW, &shm);
808 if (ret < 0)
809 goto err;
810 cr = shm;
811 cr->result_size = size;
812 cr->band = band;
813 if (size > 0)
814 memcpy(shm + sizeof(*cr), buf, size);
815 ret = shm_detach(shm);
816 if (ret < 0)
817 goto err;
818 ret = write_all(fd, (char *)&shmid, sizeof(int));
819 if (ret >= 0)
820 return ret;
821 err:
822 if (shm_destroy(shmid) < 0)
823 PARA_ERROR_LOG("destroy result failed\n");
824 return ret;
825 }
826
827 static int call_callback(int fd, int query_shmid)
828 {
829 void *query_shm;
830 struct callback_query *cq;
831 int ret, ret2;
832 struct afs_callback_arg aca = {.fd = fd};
833
834 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
835 if (ret < 0)
836 return ret;
837 cq = query_shm;
838 aca.query.data = (char *)query_shm + sizeof(*cq);
839 aca.query.size = cq->query_size;
840 aca.pbout.max_size = shm_get_shmmax();
841 aca.pbout.max_size_handler = afs_max_size_handler;
842 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
843 .fd = fd,
844 .band = SBD_OUTPUT
845 };
846 ret = cq->handler(&aca);
847 ret2 = shm_detach(query_shm);
848 if (ret2 < 0) {
849 if (ret < 0) /* ignore (but log) detach error */
850 PARA_ERROR_LOG("could not detach sma: %s\n",
851 para_strerror(-ret2));
852 else
853 ret = ret2;
854 }
855 flush_and_free_pb(&aca.pbout);
856 if (ret < 0) {
857 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
858 (const char *)&ret, sizeof(ret));
859 if (ret2 < 0)
860 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
861 para_strerror(-ret));
862 }
863 return ret;
864 }
865
866 static int execute_server_command(fd_set *rfds)
867 {
868 char buf[8];
869 size_t n;
870 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
871
872 if (ret < 0 || n == 0)
873 return ret;
874 buf[n] = '\0';
875 if (strcmp(buf, "new"))
876 return -ERRNO_TO_PARA_ERROR(EINVAL);
877 return open_next_audio_file();
878 }
879
880 /* returns 0 if no data available, 1 else */
881 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
882 {
883 uint32_t cookie;
884 int query_shmid;
885 char buf[sizeof(cookie) + sizeof(query_shmid)];
886 size_t n;
887 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
888
889 if (ret < 0)
890 goto err;
891 if (n == 0)
892 return 0;
893 if (n != sizeof(buf)) {
894 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
895 ret, (long unsigned) sizeof(buf));
896 return 1;
897 }
898 cookie = *(uint32_t *)buf;
899 if (cookie != expected_cookie) {
900 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
901 (unsigned)cookie, (unsigned)expected_cookie);
902 return 1;
903 }
904 query_shmid = *(int *)(buf + sizeof(cookie));
905 if (query_shmid < 0) {
906 PARA_WARNING_LOG("received invalid query shmid %d)\n",
907 query_shmid);
908 return 1;
909 }
910 ret = call_callback(fd, query_shmid);
911 if (ret >= 0)
912 return 1;
913 err:
914 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
915 return 1;
916 }
917
918 /** Shutdown connection if query has not arrived until this many seconds. */
919 #define AFS_CLIENT_TIMEOUT 3
920
921 static int command_post_select(struct sched *s, void *context)
922 {
923 struct command_task *ct = context;
924 struct sockaddr_un unix_addr;
925 struct afs_client *client, *tmp;
926 int fd, ret;
927
928 ret = task_get_notification(ct->task);
929 if (ret < 0)
930 return ret;
931 ret = execute_server_command(&s->rfds);
932 if (ret < 0) {
933 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
934 task_notify_all(s, -ret);
935 return ret;
936 }
937 /* Check the list of connected clients. */
938 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
939 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
940 if (ret == 0) { /* prevent bogus connection flooding */
941 struct timeval diff;
942 tv_diff(now, &client->connect_time, &diff);
943 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
944 continue;
945 PARA_WARNING_LOG("connection timeout\n");
946 }
947 close(client->fd);
948 list_del(&client->node);
949 free(client);
950 }
951 /* Accept connections on the local socket. */
952 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
953 if (ret < 0)
954 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
955 if (ret <= 0)
956 return 0;
957 ret = mark_fd_nonblocking(fd);
958 if (ret < 0) {
959 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
960 close(fd);
961 return 0;
962 }
963 client = para_malloc(sizeof(*client));
964 client->fd = fd;
965 client->connect_time = *now;
966 para_list_add(&client->node, &afs_client_list);
967 return 0;
968 }
969
970 static void register_command_task(uint32_t cookie, struct sched *s)
971 {
972 struct command_task *ct = &command_task_struct;
973 ct->fd = setup_command_socket_or_die();
974 ct->cookie = cookie;
975
976 ct->task = task_register(&(struct task_info) {
977 .name = "afs command",
978 .pre_select = command_pre_select,
979 .post_select = command_post_select,
980 .context = ct,
981 }, s);
982 }
983
984 /**
985 * Initialize the audio file selector process.
986 *
987 * \param cookie The value used for "authentication".
988 * \param socket_fd File descriptor used for communication with the server.
989 */
990 __noreturn void afs_init(uint32_t cookie, int socket_fd)
991 {
992 static struct sched s;
993 int i, ret;
994
995 register_signal_task(&s);
996 INIT_LIST_HEAD(&afs_client_list);
997 for (i = 0; i < NUM_AFS_TABLES; i++)
998 afs_tables[i].init(&afs_tables[i]);
999 ret = open_afs_tables();
1000 if (ret < 0)
1001 goto out;
1002 server_socket = socket_fd;
1003 ret = mark_fd_nonblocking(server_socket);
1004 if (ret < 0)
1005 goto out_close;
1006 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1007 server_socket, (unsigned) cookie);
1008 init_admissible_files(conf.afs_initial_mode_arg);
1009 register_command_task(cookie, &s);
1010 s.default_timeout.tv_sec = 0;
1011 s.default_timeout.tv_usec = 999 * 1000;
1012 ret = write(socket_fd, "\0", 1);
1013 if (ret != 1) {
1014 if (ret == 0)
1015 errno = EINVAL;
1016 ret = -ERRNO_TO_PARA_ERROR(errno);
1017 goto out_close;
1018 }
1019 ret = schedule(&s);
1020 sched_shutdown(&s);
1021 out_close:
1022 close_afs_tables();
1023 out:
1024 if (ret < 0)
1025 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1026 exit(EXIT_FAILURE);
1027 }
1028
1029 static int com_init_callback(struct afs_callback_arg *aca)
1030 {
1031 uint32_t table_mask = *(uint32_t *)aca->query.data;
1032 int i, ret;
1033
1034 close_afs_tables();
1035 for (i = 0; i < NUM_AFS_TABLES; i++) {
1036 struct afs_table *t = &afs_tables[i];
1037
1038 if (!(table_mask & (1 << i)))
1039 continue;
1040 if (!t->create)
1041 continue;
1042 ret = t->create(database_dir);
1043 if (ret < 0) {
1044 para_printf(&aca->pbout, "cannot create table %s\n",
1045 t->name);
1046 goto out;
1047 }
1048 para_printf(&aca->pbout, "successfully created %s table\n",
1049 t->name);
1050 }
1051 ret = open_afs_tables();
1052 if (ret < 0)
1053 para_printf(&aca->pbout, "cannot open afs tables\n");
1054 out:
1055 return ret;
1056 }
1057
1058 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1059 {
1060 int i, j, ret;
1061 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1062 struct osl_object query = {.data = &table_mask,
1063 .size = sizeof(table_mask)};
1064 unsigned num_inputs = lls_num_inputs(lpr);
1065
1066 ret = make_database_dir();
1067 if (ret < 0)
1068 return ret;
1069 if (num_inputs > 0) {
1070 table_mask = 0;
1071 for (i = 0; i < num_inputs; i++) {
1072 for (j = 0; j < NUM_AFS_TABLES; j++) {
1073 struct afs_table *t = &afs_tables[j];
1074
1075 if (strcmp(lls_input(i, lpr), t->name))
1076 continue;
1077 table_mask |= (1 << j);
1078 break;
1079 }
1080 if (j == NUM_AFS_TABLES)
1081 return -E_BAD_TABLE_NAME;
1082 }
1083 }
1084 return send_callback_request(com_init_callback, &query,
1085 afs_cb_result_handler, cc);
1086 }
1087 EXPORT_SERVER_CMD_HANDLER(init);
1088
1089 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1090 {
1091 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1092 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1093 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1094 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1095 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1096 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1097 int ret;
1098
1099 if (noopt || lls_opt_given(r_a)) {
1100 ret = send_callback_request(aft_check_callback, NULL,
1101 afs_cb_result_handler, cc);
1102 if (ret < 0)
1103 return ret;
1104 }
1105 if (noopt || lls_opt_given(r_A)) {
1106 ret = send_callback_request(attribute_check_callback, NULL,
1107 afs_cb_result_handler, cc);
1108 if (ret < 0)
1109 return ret;
1110 }
1111 if (noopt || lls_opt_given(r_p)) {
1112 ret = send_callback_request(playlist_check_callback,
1113 NULL, afs_cb_result_handler, cc);
1114 if (ret < 0)
1115 return ret;
1116 }
1117 if (noopt || lls_opt_given(r_m)) {
1118 ret = send_callback_request(mood_check_callback, NULL,
1119 afs_cb_result_handler, cc);
1120 if (ret < 0)
1121 return ret;
1122 }
1123 return 1;
1124 }
1125 EXPORT_SERVER_CMD_HANDLER(check);
1126
1127 /**
1128 * The afs event dispatcher.
1129 *
1130 * \param event Type of the event.
1131 * \param pb May be \p NULL.
1132 * \param data Type depends on \a event.
1133 *
1134 * This function calls each table event handler, passing \a pb and \a data
1135 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1136 * handler returns negative, the loop is aborted.
1137 *
1138 * \return The (negative) error code of the first handler that failed, or non-negative
1139 * if all handlers succeeded.
1140 */
1141 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1142 void *data)
1143 {
1144 int i, ret;
1145
1146 for (i = 0; i < NUM_AFS_TABLES; i++) {
1147 struct afs_table *t = &afs_tables[i];
1148 if (!t->event_handler)
1149 continue;
1150 ret = t->event_handler(event, pb, data);
1151 if (ret < 0) {
1152 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1153 event, para_strerror(-ret));
1154 return ret;
1155 }
1156 }
1157 return 1;
1158 }
1159
1160 /**
1161 * Dummy event handler for the images table.
1162 *
1163 * \param event Unused.
1164 * \param pb Unused.
1165 * \param data Unused.
1166 *
1167 * \return The images table does not honor events, so this handler always
1168 * returns success.
1169 */
1170 __a_const int images_event_handler(__a_unused enum afs_events event,
1171 __a_unused struct para_buffer *pb, __a_unused void *data)
1172 {
1173 return 1;
1174 }
1175
1176 /**
1177 * Dummy event handler for the lyrics table.
1178 *
1179 * \param event Unused.
1180 * \param pb Unused.
1181 * \param data Unused.
1182 *
1183 * \return The lyrics table does not honor events, so this handler always
1184 * returns success.
1185 */
1186 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1187 __a_unused struct para_buffer *pb, __a_unused void *data)
1188 {
1189 return 1;
1190 }