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