Simplify init_admissible_files().
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
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 <signal.h>
10 #include <fnmatch.h>
11 #include "server.cmdline.h"
12 #include "para.h"
13 #include "error.h"
14 #include "string.h"
15 #include "afh.h"
16 #include "afs.h"
17 #include "server.h"
18 #include <dirent.h> /* readdir() */
19 #include <sys/mman.h>
20 #include <sys/time.h>
21 #include "net.h"
22 #include "ipc.h"
23 #include "list.h"
24 #include "sched.h"
25 #include "signal.h"
26 #include "fd.h"
27
28 /** The osl tables used by afs. \sa blob.c. */
29 enum afs_table_num {
30 /** Contains audio file information. See aft.c. */
31 TBLNUM_AUDIO_FILES,
32 /** The table for the paraslash attributes. See attribute.c. */
33 TBLNUM_ATTRIBUTES,
34 /**
35 * Paraslash's scoring system is based on Gaussian normal
36 * distributions, and the relevant data is stored in the rbtrees of an
37 * osl table containing only volatile columns. See score.c for
38 * details.
39 */
40 TBLNUM_SCORES,
41 /**
42 * A standard blob table containing the mood definitions. For details
43 * see mood.c.
44 */
45 TBLNUM_MOODS,
46 /** A blob table containing lyrics on a per-song basis. */
47 TBLNUM_LYRICS,
48 /** Another blob table for images (for example album cover art). */
49 TBLNUM_IMAGES,
50 /** Yet another blob table for storing standard playlists. */
51 TBLNUM_PLAYLIST,
52 /** How many tables are in use? */
53 NUM_AFS_TABLES
54 };
55
56 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
57 [TBLNUM_AUDIO_FILES] = {.init = aft_init},
58 [TBLNUM_ATTRIBUTES] = {.init = attribute_init},
59 [TBLNUM_SCORES] = {.init = score_init},
60 [TBLNUM_MOODS] = {.init = moods_init},
61 [TBLNUM_LYRICS] = {.init = lyrics_init},
62 [TBLNUM_IMAGES] = {.init = images_init},
63 [TBLNUM_PLAYLIST] = {.init = playlists_init},
64 };
65
66 struct command_task {
67 /** The file descriptor for the local socket. */
68 int fd;
69 /**
70 * Value sent by the command handlers to identify themselves as
71 * children of the running para_server.
72 */
73 uint32_t cookie;
74 /** The associated task structure. */
75 struct task task;
76 };
77
78 extern struct misc_meta_data *mmd;
79
80 static int server_socket;
81 static struct command_task command_task_struct;
82 static struct signal_task signal_task_struct;
83
84 static enum play_mode current_play_mode;
85 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
86
87
88 /**
89 * A random number used to "authenticate" the connection.
90 *
91 * para_server picks this number by random before forking the afs process. The
92 * command handlers write this number together with the id of the shared memory
93 * area containing the query. This way, a malicious local user has to know this
94 * number to be able to cause the afs process to crash by sending fake queries.
95 */
96 extern uint32_t afs_socket_cookie;
97
98 /**
99 * Struct to let command handlers execute a callback in afs context.
100 *
101 * Commands that need to change the state of afs can't change the relevant data
102 * structures directly because commands are executed in a child process, i.e.
103 * they get their own virtual address space.
104 *
105 * This structure is used by \p send_callback_request() (executed from handler
106 * context) in order to let the afs process call the specified function. An
107 * instance of that structure is written to a shared memory area together with
108 * the arguments to the callback function. The identifier of the shared memory
109 * area is written to the command socket.
110 *
111 * The afs process accepts connections on the command socket and reads the
112 * shared memory id, attaches the corresponing area, calls the given handler to
113 * perform the desired action and to optionally compute a result.
114 *
115 * The result and a \p callback_result structure is then written to another
116 * shared memory area. The identifier for that area is written to the handler's
117 * command socket, so that the handler process can read the id, attach the
118 * shared memory area and use the result.
119 *
120 * \sa struct callback_result.
121 */
122 struct callback_query {
123 /** The function to be called. */
124 callback_function *handler;
125 /** The number of bytes of the query */
126 size_t query_size;
127 };
128
129 /**
130 * Structure embedded in the result of a callback.
131 *
132 * If the callback produced a result, an instance of that structure is embeeded
133 * into the shared memory area holding the result, mainly to let the command
134 * handler know the size of the result.
135 *
136 * \sa struct callback_query.
137 */
138 struct callback_result {
139 /** The number of bytes of the result. */
140 size_t result_size;
141 };
142
143 /**
144 * Ask the afs process to call a given function.
145 *
146 * \param f The function to be called.
147 * \param query Pointer to arbitrary data for the callback.
148 * \param result Callback result will be stored here.
149 *
150 * This function creates a shared memory area, copies the buffer pointed to by
151 * query to that area and notifies the afs process that \a f should be
152 * called ASAP.
153 *
154 * \return Negative, on errors, the return value of the callback function
155 * otherwise.
156 *
157 * \sa send_option_arg_callback_request(), send_standard_callback_request().
158 */
159 int send_callback_request(callback_function *f, struct osl_object *query,
160 struct osl_object *result)
161 {
162 struct callback_query *cq;
163 struct callback_result *cr;
164 int ret, fd = -1, query_shmid, result_shmid;
165 void *query_shm, *result_shm;
166 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
167 struct sockaddr_un unix_addr;
168 size_t query_shm_size = sizeof(*cq);
169
170 if (query)
171 query_shm_size += query->size;
172 ret = shm_new(query_shm_size);
173 if (ret < 0)
174 return ret;
175 query_shmid = ret;
176 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
177 if (ret < 0)
178 goto out;
179 cq = query_shm;
180 cq->handler = f;
181 cq->query_size = query_shm_size - sizeof(*cq);
182
183 if (query)
184 memcpy(query_shm + sizeof(*cq), query->data, query->size);
185 ret = shm_detach(query_shm);
186 if (ret < 0)
187 goto out;
188
189 *(uint32_t *) buf = afs_socket_cookie;
190 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
191
192 ret = get_stream_socket(PF_UNIX);
193 if (ret < 0)
194 goto out;
195 fd = ret;
196 ret = init_unix_addr(&unix_addr, conf.afs_socket_arg);
197 if (ret < 0)
198 goto out;
199 ret = PARA_CONNECT(fd, &unix_addr);
200 if (ret < 0)
201 goto out;
202 ret = send_bin_buffer(fd, buf, sizeof(buf));
203 if (ret < 0)
204 goto out;
205 ret = recv_bin_buffer(fd, buf, sizeof(buf));
206 if (ret < 0)
207 goto out;
208 if (ret != sizeof(int)) {
209 ret = -E_RECV;
210 goto out;
211 }
212 ret = *(int *) buf;
213 if (ret <= 0)
214 goto out;
215 result_shmid = ret;
216 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
217 if (ret >= 0) {
218 assert(result);
219 cr = result_shm;
220 result->size = cr->result_size;
221 result->data = para_malloc(result->size);
222 memcpy(result->data, result_shm + sizeof(*cr), result->size);
223 ret = shm_detach(result_shm);
224 if (ret < 0)
225 PARA_ERROR_LOG("can not detach result\n");
226 } else
227 PARA_ERROR_LOG("attach result failed: %d\n", ret);
228 if (shm_destroy(result_shmid) < 0)
229 PARA_ERROR_LOG("destroy result failed\n");
230 ret = 1;
231 out:
232 if (shm_destroy(query_shmid) < 0)
233 PARA_ERROR_LOG("%s\n", "shm destroy error");
234 if (fd >= 0)
235 close(fd);
236 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
237 return ret;
238 }
239
240 /**
241 * Send a callback request passing an options structure and an argument vector.
242 *
243 * \param options pointer to an arbitrary data structure.
244 * \param argc Argument count.
245 * \param argv Standard argument vector.
246 * \param f The callback function.
247 * \param result The result of the query is stored here.
248 *
249 * Some commands have a couple of options that are parsed in child context for
250 * syntactic correctness and are stored in a special options structure for that
251 * command. This function allows to pass such a structure together with a list
252 * of further arguments (often a list of audio files) to the parent process.
253 *
254 * \sa send_standard_callback_request(), send_callback_request().
255 */
256 int send_option_arg_callback_request(struct osl_object *options,
257 int argc, char * const * const argv, callback_function *f,
258 struct osl_object *result)
259 {
260 char *p;
261 int i, ret;
262 struct osl_object query = {.size = options? options->size : 0};
263
264 for (i = 0; i < argc; i++)
265 query.size += strlen(argv[i]) + 1;
266 query.data = para_malloc(query.size);
267 p = query.data;
268 if (options) {
269 memcpy(query.data, options->data, options->size);
270 p += options->size;
271 }
272 for (i = 0; i < argc; i++) {
273 strcpy(p, argv[i]); /* OK */
274 p += strlen(argv[i]) + 1;
275 }
276 ret = send_callback_request(f, &query, result);
277 free(query.data);
278 return ret;
279 }
280
281 /**
282 * Send a callback request with an argument vector only.
283 *
284 * \param argc The same meaning as in send_option_arg_callback_request().
285 * \param argv The same meaning as in send_option_arg_callback_request().
286 * \param f The same meaning as in send_option_arg_callback_request().
287 * \param result The same meaning as in send_option_arg_callback_request().
288 *
289 * This is similar to send_option_arg_callback_request(), but no options buffer
290 * is passed to the parent process.
291 *
292 * \return The return value of the underlying call to
293 * send_option_arg_callback_request().
294 */
295 int send_standard_callback_request(int argc, char * const * const argv,
296 callback_function *f, struct osl_object *result)
297 {
298 return send_option_arg_callback_request(NULL, argc, argv, f, result);
299 }
300
301 static int action_if_pattern_matches(struct osl_row *row, void *data)
302 {
303 struct pattern_match_data *pmd = data;
304 struct osl_object name_obj;
305 const char *p, *name;
306 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
307 const char *pattern_txt = (const char *)pmd->patterns.data;
308
309 if (ret < 0)
310 return ret;
311 name = (char *)name_obj.data;
312 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
313 return 1;
314 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
315 return pmd->action(pmd->table, row, name, pmd->data);
316 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
317 p += strlen(p) + 1) {
318 ret = fnmatch(p, name, pmd->fnmatch_flags);
319 if (ret == FNM_NOMATCH)
320 continue;
321 if (ret)
322 return -E_FNMATCH;
323 return pmd->action(pmd->table, row, name, pmd->data);
324 }
325 return 1;
326 }
327
328 /**
329 * Execute the given function for each matching row.
330 *
331 * \param pmd Describes what to match and how.
332 *
333 * \return The return value of the underlying call to osl_rbtree_loop()
334 * or osl_rbtree_loop_reverse().
335 */
336 int for_each_matching_row(struct pattern_match_data *pmd)
337 {
338 if (pmd->pm_flags & PM_REVERSE_LOOP)
339 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
340 action_if_pattern_matches);
341 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
342 action_if_pattern_matches);
343 }
344
345 /**
346 * Compare two osl objects of string type.
347 *
348 * \param obj1 Pointer to the first object.
349 * \param obj2 Pointer to the second object.
350 *
351 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
352 * are taken into account.
353 *
354 * \return It returns an integer less than, equal to, or greater than zero if
355 * \a obj1 is found, respectively, to be less than, to match, or be greater than
356 * obj2.
357 *
358 * \sa strcmp(3), strncmp(3), osl_compare_func.
359 */
360 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
361 {
362 const char *str1 = (const char *)obj1->data;
363 const char *str2 = (const char *)obj2->data;
364 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
365 }
366
367 /*
368 * write input from fd to dynamically allocated buffer,
369 * but maximal max_size byte.
370 */
371 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
372 {
373 const size_t chunk_size = 1024;
374 size_t size = 2048, received = 0;
375 int ret;
376 char *buf = para_malloc(size);
377
378 for (;;) {
379 ret = recv_bin_buffer(fd, buf + received, chunk_size);
380 if (ret <= 0)
381 break;
382 received += ret;
383 if (received + chunk_size >= size) {
384 size *= 2;
385 ret = -E_INPUT_TOO_LARGE;
386 if (size > max_size)
387 break;
388 buf = para_realloc(buf, size);
389 }
390 }
391 obj->data = buf;
392 obj->size = received;
393 if (ret < 0)
394 free(buf);
395 return ret;
396 }
397
398 /**
399 * Read data from a file descriptor, and send it to the afs process.
400 *
401 * \param fd File descriptor to read data from.
402 * \param arg_obj Pointer to the arguments to \a f.
403 * \param f The callback function.
404 * \param max_len Don't read more than that many bytes from stdin.
405 * \param result The result of the query is stored here.
406 *
407 * This function is used by commands that wish to let para_server store
408 * arbitrary data specified by the user (for instance the add_blob family of
409 * commands). First, at most \a max_len bytes are read from \a fd, the result
410 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
411 * is made available to the parent process via shared memory.
412 *
413 * \return Negative on errors, the return value of the underlying call to
414 * send_callback_request() otherwise.
415 */
416 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
417 unsigned max_len, struct osl_object *result)
418 {
419 struct osl_object query, stdin_obj;
420 int ret;
421
422 ret = send_buffer(fd, AWAITING_DATA_MSG);
423 if (ret < 0)
424 return ret;
425 ret = fd2buf(fd, max_len, &stdin_obj);
426 if (ret < 0)
427 return ret;
428 query.size = arg_obj->size + stdin_obj.size;
429 query.data = para_malloc(query.size);
430 memcpy(query.data, arg_obj->data, arg_obj->size);
431 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
432 free(stdin_obj.data);
433 ret = send_callback_request(f, &query, result);
434 free(query.data);
435 return ret;
436 }
437
438 static int pass_afd(int fd, char *buf, size_t size)
439 {
440 struct msghdr msg = {.msg_iov = NULL};
441 struct cmsghdr *cmsg;
442 char control[255];
443 int ret;
444 struct iovec iov;
445
446 iov.iov_base = buf;
447 iov.iov_len = size;
448
449 msg.msg_iov = &iov;
450 msg.msg_iovlen = 1;
451
452 msg.msg_control = control;
453 msg.msg_controllen = sizeof(control);
454
455 cmsg = CMSG_FIRSTHDR(&msg);
456 cmsg->cmsg_level = SOL_SOCKET;
457 cmsg->cmsg_type = SCM_RIGHTS;
458 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
459 *(int *)CMSG_DATA(cmsg) = fd;
460
461 /* Sum of the length of all control messages in the buffer */
462 msg.msg_controllen = cmsg->cmsg_len;
463 PARA_NOTICE_LOG("passing %zu bytes and fd %d\n", size, fd);
464 ret = sendmsg(server_socket, &msg, 0);
465 if (ret < 0) {
466 ret = -ERRNO_TO_PARA_ERROR(errno);
467 return ret;
468 }
469 return 1;
470 }
471
472 /**
473 * Open the audio file with highest score.
474 *
475 * This stores all information for streaming the "best" audio file in a shared
476 * memory area. The id of that area and an open file descriptor for the next
477 * audio file are passed to the server process.
478 *
479 * \return Standard.
480 *
481 * \sa open_and_update_audio_file().
482 */
483 int open_next_audio_file(void)
484 {
485 struct osl_row *aft_row;
486 struct audio_file_data afd;
487 int ret, shmid;
488 char buf[8];
489
490 PARA_NOTICE_LOG("getting next af\n");
491 ret = score_get_best(&aft_row, &afd.score);
492 if (ret < 0)
493 return ret;
494 ret = open_and_update_audio_file(aft_row, &afd);
495 if (ret < 0)
496 return ret;
497 shmid = ret;
498 PARA_NOTICE_LOG("shmid: %u\n", shmid);
499 if (!write_ok(server_socket)) {
500 PARA_EMERG_LOG("afs_socket not writable\n");
501 goto destroy;
502 }
503 *(uint32_t *)buf = NEXT_AUDIO_FILE;
504 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
505 ret = pass_afd(afd.fd, buf, 8);
506 close(afd.fd);
507 if (ret >= 0)
508 return ret;
509 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
510 destroy:
511 shm_destroy(shmid);
512 return ret;
513 }
514
515 /* Never fails if arg == NULL */
516 static int activate_mood_or_playlist(char *arg, int *num_admissible)
517 {
518 enum play_mode mode;
519 int ret;
520
521 if (!arg) {
522 ret = change_current_mood(NULL); /* always successful */
523 mode = PLAY_MODE_MOOD;
524 } else {
525 if (!strncmp(arg, "p:", 2)) {
526 ret = playlist_open(arg + 2);
527 mode = PLAY_MODE_PLAYLIST;
528 } else if (!strncmp(arg, "m:", 2)) {
529 ret = change_current_mood(arg + 2);
530 mode = PLAY_MODE_MOOD;
531 } else
532 ret = -E_AFS_SYNTAX;
533 if (ret < 0)
534 return ret;
535 }
536 if (num_admissible)
537 *num_admissible = ret;
538 current_play_mode = mode;
539 if (arg != current_mop) {
540 free(current_mop);
541 if (arg) {
542 current_mop = para_strdup(arg);
543 mmd_lock();
544 strcpy(mmd->afs_mode_string, arg); /* FIXME: check length */
545 mmd_unlock();
546 } else {
547 mmd_lock();
548 strcpy(mmd->afs_mode_string, "dummy");
549 mmd_unlock();
550 current_mop = NULL;
551 }
552 }
553 return 1;
554 }
555
556 static int com_select_callback(const struct osl_object *query,
557 struct osl_object *result)
558 {
559 struct para_buffer pb = {.buf = NULL};
560 char *arg = query->data;
561 int num_admissible, ret;
562
563 ret = clear_score_table();
564 if (ret < 0)
565 return ret;
566 if (current_play_mode == PLAY_MODE_MOOD)
567 close_current_mood();
568 else
569 playlist_close();
570 ret = activate_mood_or_playlist(arg, &num_admissible);
571 if (ret < 0) {
572 para_printf(&pb, "%s\n", PARA_STRERROR(-ret));
573 para_printf(&pb, "switching back to %s\n", current_mop?
574 current_mop : "dummy");
575 ret = activate_mood_or_playlist(current_mop, &num_admissible);
576 if (ret < 0) {
577 para_printf(&pb, "failed, switching to dummy\n");
578 activate_mood_or_playlist(NULL, &num_admissible);
579 }
580 }
581 para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
582 current_mop : "dummy mood", num_admissible);
583 result->data = pb.buf;
584 result->size = pb.size;
585 return 1;
586 }
587
588 int com_select(int fd, int argc, char * const * const argv)
589 {
590 int ret;
591 struct osl_object query, result;
592
593 if (argc != 2)
594 return -E_AFS_SYNTAX;
595 query.data = argv[1];
596 query.size = strlen(argv[1]) + 1;
597 ret = send_callback_request(com_select_callback, &query,
598 &result);
599 if (ret > 0 && result.data && result.size) {
600 ret = send_va_buffer(fd, "%s", (char *)result.data);
601 free(result.data);
602 }
603 return ret;
604 }
605
606 static void init_admissible_files(char *arg)
607 {
608 if (activate_mood_or_playlist(arg, NULL) < 0)
609 activate_mood_or_playlist(NULL, NULL); /* always successful */
610 }
611
612 static int setup_command_socket_or_die(void)
613 {
614 int ret;
615 char *socket_name = conf.afs_socket_arg;
616 struct sockaddr_un unix_addr;
617
618 unlink(socket_name);
619 ret = create_local_socket(socket_name, &unix_addr,
620 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
621 if (ret < 0) {
622 PARA_EMERG_LOG("%s: %s\n", PARA_STRERROR(-ret), socket_name);
623 exit(EXIT_FAILURE);
624 }
625 if (listen(ret , 5) < 0) {
626 PARA_EMERG_LOG("%s", "can not listen on socket\n");
627 exit(EXIT_FAILURE);
628 }
629 PARA_INFO_LOG("listening on command socket %s (fd %d)\n", socket_name,
630 ret);
631 return ret;
632 }
633
634 static void close_afs_tables(void)
635 {
636 int i;
637 PARA_NOTICE_LOG("closing afs_tables\n");
638 for (i = 0; i < NUM_AFS_TABLES; i++)
639 afs_tables[i].close();
640 }
641
642 static char *database_dir;
643
644 static void get_database_dir(void)
645 {
646 if (!database_dir) {
647 if (conf.afs_database_dir_given)
648 database_dir = para_strdup(conf.afs_database_dir_arg);
649 else {
650 char *home = para_homedir();
651 database_dir = make_message(
652 "%s/.paraslash/afs_database", home);
653 free(home);
654 }
655 }
656 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
657 }
658
659 static int make_database_dir(void)
660 {
661 int ret;
662
663 get_database_dir();
664 ret = para_mkdir(database_dir, 0777);
665 if (ret >= 0 || is_errno(-ret, EEXIST))
666 return 1;
667 return ret;
668 }
669
670 static int open_afs_tables(void)
671 {
672 int i, ret;
673
674 get_database_dir();
675 for (i = 0; i < NUM_AFS_TABLES; i++) {
676 ret = afs_tables[i].open(database_dir);
677 if (ret >= 0)
678 continue;
679 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
680 PARA_STRERROR(-ret));
681 break;
682 }
683 if (ret >= 0)
684 return ret;
685 while (i)
686 afs_tables[--i].close();
687 return ret;
688 }
689
690 static void unregister_tasks(void)
691 {
692 unregister_task(&command_task_struct.task);
693 unregister_task(&signal_task_struct.task);
694 }
695
696 static void signal_pre_select(struct sched *s, struct task *t)
697 {
698 struct signal_task *st = t->private_data;
699 t->ret = 1;
700 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
701 }
702
703 static void signal_post_select(struct sched *s, struct task *t)
704 {
705 struct signal_task *st = t->private_data;
706 t->ret = -E_AFS_PARENT_DIED;
707 if (getppid() == 1)
708 goto err;
709 t->ret = 1;
710 if (!FD_ISSET(st->fd, &s->rfds))
711 return;
712 st->signum = para_next_signal();
713 t->ret = 1;
714 if (st->signum == SIGUSR1)
715 return; /* ignore SIGUSR1 */
716 if (st->signum == SIGHUP) {
717 close_afs_tables();
718 t->ret = open_afs_tables();
719 /* FIXME: Restore current mood or playlist */
720 if (t->ret < 0)
721 goto err;
722 return;
723 }
724 t->ret = -E_AFS_SIGNAL;
725 err:
726 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
727 unregister_tasks();
728 }
729
730 static void register_signal_task(void)
731 {
732 struct signal_task *st = &signal_task_struct;
733 st->fd = para_signal_init();
734 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
735 para_install_sighandler(SIGINT);
736 para_install_sighandler(SIGTERM);
737 para_install_sighandler(SIGPIPE);
738 para_install_sighandler(SIGHUP);
739
740 st->task.pre_select = signal_pre_select;
741 st->task.post_select = signal_post_select;
742 st->task.private_data = st;
743 sprintf(st->task.status, "signal task");
744 register_task(&st->task);
745 }
746
747 static struct list_head afs_client_list;
748
749 struct afs_client {
750 struct list_head node;
751 int fd;
752 struct timeval connect_time;
753 };
754
755 static void command_pre_select(struct sched *s, struct task *t)
756 {
757 struct command_task *ct = t->private_data;
758 struct afs_client *client;
759
760 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
761 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
762 list_for_each_entry(client, &afs_client_list, node)
763 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
764 t->ret = 1;
765 }
766
767 /*
768 * On errors, negative value is written to fd.
769 * On success: If query produced a result, the result_shmid is written to fd.
770 * Otherwise, zero is written.
771 */
772 static int call_callback(int fd, int query_shmid)
773 {
774 void *query_shm, *result_shm;
775 struct callback_query *cq;
776 struct callback_result *cr;
777 struct osl_object query, result = {.data = NULL};
778 int result_shmid = -1, ret, ret2;
779
780 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
781 if (ret < 0)
782 goto out;
783 cq = query_shm;
784 query.data = (char *)query_shm + sizeof(*cq);
785 query.size = cq->query_size;
786 ret = cq->handler(&query, &result);
787 ret2 = shm_detach(query_shm);
788 if (ret2 < 0 && ret >= 0)
789 ret = ret2;
790 if (ret < 0)
791 goto out;
792 ret = 0;
793 if (!result.data || !result.size)
794 goto out;
795 ret = shm_new(result.size + sizeof(struct callback_result));
796 if (ret < 0)
797 goto out;
798 result_shmid = ret;
799 ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
800 if (ret < 0)
801 goto out;
802 cr = result_shm;
803 cr->result_size = result.size;
804 memcpy(result_shm + sizeof(*cr), result.data, result.size);
805 ret = shm_detach(result_shm);
806 if (ret < 0)
807 goto out;
808 ret = result_shmid;
809 out:
810 free(result.data);
811 ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int));
812 if (ret < 0 || ret2 < 0) {
813 if (result_shmid >= 0)
814 if (shm_destroy(result_shmid) < 0)
815 PARA_ERROR_LOG("destroy result failed\n");
816 if (ret >= 0)
817 ret = ret2;
818 }
819 return ret;
820 }
821
822 static void execute_server_command(void)
823 {
824 char buf[8];
825 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
826
827 if (ret <= 0) {
828 if (ret < 0)
829 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
830 return;
831 }
832 buf[ret] = '\0';
833 PARA_NOTICE_LOG("received: %s\n", buf);
834 if (!strcmp(buf, "new")) {
835 ret = open_next_audio_file();
836 PARA_NOTICE_LOG("ret: %d\n", ret);
837 return;
838 }
839 PARA_ERROR_LOG("unknown command\n");
840
841 }
842
843 static void execute_afs_command(int fd, uint32_t expected_cookie)
844 {
845 uint32_t cookie;
846 int query_shmid;
847 char buf[sizeof(cookie) + sizeof(query_shmid)];
848 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
849
850 if (ret < 0) {
851 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
852 return;
853 }
854 if (ret != sizeof(buf)) {
855 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
856 ret, (long unsigned) sizeof(buf));
857 return;
858 }
859 cookie = *(uint32_t *)buf;
860 if (cookie != expected_cookie) {
861 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
862 (unsigned)cookie, (unsigned)expected_cookie);
863 return;
864 }
865 query_shmid = *(int *)(buf + sizeof(cookie));
866 if (query_shmid < 0) {
867 PARA_WARNING_LOG("received invalid query shmid %d)\n",
868 query_shmid);
869 return;
870 }
871 /* Ignore return value: Errors might be OK here. */
872 call_callback(fd, query_shmid);
873 }
874
875 /** Shutdown connection if query has not arrived until this many seconds. */
876 #define AFS_CLIENT_TIMEOUT 3
877
878 static void command_post_select(struct sched *s, struct task *t)
879 {
880 struct command_task *ct = t->private_data;
881 struct sockaddr_un unix_addr;
882 struct afs_client *client, *tmp;
883
884 if (FD_ISSET(server_socket, &s->rfds))
885 execute_server_command();
886
887 /* Check the list of connected clients. */
888 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
889 if (FD_ISSET(client->fd, &s->rfds))
890 execute_afs_command(client->fd, ct->cookie);
891 else { /* prevent bogus connection flooding */
892 struct timeval diff;
893 tv_diff(now, &client->connect_time, &diff);
894 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
895 continue;
896 PARA_WARNING_LOG("connection timeout\n");
897 }
898 close(client->fd);
899 list_del(&client->node);
900 free(client);
901 }
902 /* Accept connections on the local socket. */
903 if (!FD_ISSET(ct->fd, &s->rfds))
904 goto out;
905 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
906 if (t->ret < 0) {
907 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
908 goto out;
909 }
910 client = para_malloc(sizeof(*client));
911 client->fd = t->ret;
912 client->connect_time = *now;
913 para_list_add(&client->node, &afs_client_list);
914 out:
915 t->ret = 1;
916 }
917
918 static void register_command_task(uint32_t cookie)
919 {
920 struct command_task *ct = &command_task_struct;
921 ct->fd = setup_command_socket_or_die();
922 ct->cookie = cookie;
923
924 ct->task.pre_select = command_pre_select;
925 ct->task.post_select = command_post_select;
926 ct->task.private_data = ct;
927 sprintf(ct->task.status, "command task");
928 register_task(&ct->task);
929 }
930
931 static void register_tasks(uint32_t cookie)
932 {
933 register_signal_task();
934 register_command_task(cookie);
935 }
936
937 /**
938 * Initialize the audio file selector process.
939 *
940 * \param cookie The value used for "authentication".
941 * \param socket_fd File descriptor used for communication with the server.
942 */
943 __noreturn void afs_init(uint32_t cookie, int socket_fd)
944 {
945 struct sched s;
946 int i, ret;
947
948 INIT_LIST_HEAD(&afs_client_list);
949 for (i = 0; i < NUM_AFS_TABLES; i++)
950 afs_tables[i].init(&afs_tables[i]);
951 ret = open_afs_tables();
952
953 if (ret < 0) {
954 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
955 exit(EXIT_FAILURE);
956 }
957 server_socket = socket_fd;
958 ret = mark_fd_nonblock(server_socket);
959 if (ret < 0)
960 exit(EXIT_FAILURE);
961 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
962 server_socket, (unsigned) cookie);
963 init_admissible_files(conf.afs_initial_mode_arg);
964 register_tasks(cookie);
965 s.default_timeout.tv_sec = 0;
966 s.default_timeout.tv_usec = 999 * 1000;
967 ret = sched(&s);
968 if (ret < 0)
969 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
970 close_afs_tables();
971 exit(EXIT_FAILURE);
972 }
973
974 static int create_tables_callback(const struct osl_object *query,
975 __a_unused struct osl_object *result)
976 {
977 uint32_t table_mask = *(uint32_t *)query->data;
978 int i, ret;
979
980 close_afs_tables();
981 for (i = 0; i < NUM_AFS_TABLES; i++) {
982 struct afs_table *t = &afs_tables[i];
983
984 if (!(table_mask & (1 << i)))
985 continue;
986 if (!t->create)
987 continue;
988 ret = t->create(database_dir);
989 if (ret < 0)
990 return ret;
991 }
992 ret = open_afs_tables();
993 return ret < 0? ret: 0;
994 }
995
996 int com_init(int fd, int argc, char * const * const argv)
997 {
998 int i, j, ret;
999 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1000 struct osl_object query = {.data = &table_mask,
1001 .size = sizeof(table_mask)};
1002
1003 ret = make_database_dir();
1004 if (ret < 0)
1005 return ret;
1006 if (argc != 1) {
1007 table_mask = 0;
1008 for (i = 1; i < argc; i++) {
1009 for (j = 0; j < NUM_AFS_TABLES; j++) {
1010 struct afs_table *t = &afs_tables[j];
1011
1012 if (strcmp(argv[i], t->name))
1013 continue;
1014 table_mask |= (1 << j);
1015 break;
1016 }
1017 if (j == NUM_AFS_TABLES)
1018 return -E_BAD_TABLE_NAME;
1019 }
1020 }
1021 ret = send_callback_request(create_tables_callback, &query, NULL);
1022 if (ret < 0)
1023 return ret;
1024 return send_va_buffer(fd, "successfully created afs table(s)\n");
1025 }
1026
1027 /**
1028 * Flags for the check command.
1029 *
1030 * \sa com_check().
1031 */
1032 enum com_check_flags {
1033 /** Check the audio file table. */
1034 CHECK_AFT = 1,
1035 /** Check the mood table. */
1036 CHECK_MOODS = 2,
1037 /** Check the playlist table. */
1038 CHECK_PLAYLISTS = 4
1039 };
1040
1041 int com_check(int fd, int argc, char * const * const argv)
1042 {
1043 unsigned flags = 0;
1044 int i, ret;
1045 struct osl_object result;
1046
1047 for (i = 1; i < argc; i++) {
1048 const char *arg = argv[i];
1049 if (arg[0] != '-')
1050 break;
1051 if (!strcmp(arg, "--")) {
1052 i++;
1053 break;
1054 }
1055 if (!strcmp(arg, "-a")) {
1056 flags |= CHECK_AFT;
1057 continue;
1058 }
1059 if (!strcmp(arg, "-p")) {
1060 flags |= CHECK_PLAYLISTS;
1061 continue;
1062 }
1063 if (!strcmp(arg, "-m")) {
1064 flags |= CHECK_MOODS;
1065 continue;
1066 }
1067 return -E_AFS_SYNTAX;
1068 }
1069 if (i < argc)
1070 return -E_AFS_SYNTAX;
1071 if (!flags)
1072 flags = ~0U;
1073 if (flags & CHECK_AFT) {
1074 ret = send_callback_request(aft_check_callback, NULL, &result);
1075 if (ret < 0)
1076 return ret;
1077 if (ret > 0) {
1078 ret = send_buffer(fd, (char *) result.data);
1079 free(result.data);
1080 if (ret < 0)
1081 return ret;
1082 }
1083 }
1084 if (flags & CHECK_PLAYLISTS) {
1085 ret = send_callback_request(playlist_check_callback, NULL, &result);
1086 if (ret < 0)
1087 return ret;
1088 if (ret > 0) {
1089 ret = send_buffer(fd, (char *) result.data);
1090 free(result.data);
1091 if (ret < 0)
1092 return ret;
1093 }
1094 }
1095 if (flags & CHECK_MOODS) {
1096 ret = send_callback_request(mood_check_callback, NULL, &result);
1097 if (ret < 0)
1098 return ret;
1099 if (ret > 0) {
1100 ret = send_buffer(fd, (char *) result.data);
1101 free(result.data);
1102 if (ret < 0)
1103 return ret;
1104 }
1105 }
1106 return 1;
1107 }
1108
1109 void afs_event(enum afs_events event, struct para_buffer *pb,
1110 void *data)
1111 {
1112 int i, ret;
1113
1114 for (i = 0; i < NUM_AFS_TABLES; i++) {
1115 struct afs_table *t = &afs_tables[i];
1116 if (!t->event_handler)
1117 continue;
1118 ret = t->event_handler(event, pb, data);
1119 if (ret < 0)
1120 PARA_CRIT_LOG("%s\n", PARA_STRERROR(-ret));
1121 }
1122 }
1123
1124 int images_event_handler(__a_unused enum afs_events event,
1125 __a_unused struct para_buffer *pb, __a_unused void *data)
1126 {
1127 return 1;
1128 }
1129
1130 int lyrics_event_handler(__a_unused enum afs_events event,
1131 __a_unused struct para_buffer *pb, __a_unused void *data)
1132 {
1133 return 1;
1134 }