doxify acl.c.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2008 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 size_t query_shm_size = sizeof(*cq);
168
169 if (query)
170 query_shm_size += query->size;
171 ret = shm_new(query_shm_size);
172 if (ret < 0)
173 return ret;
174 query_shmid = ret;
175 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
176 if (ret < 0)
177 goto out;
178 cq = query_shm;
179 cq->handler = f;
180 cq->query_size = query_shm_size - sizeof(*cq);
181
182 if (query)
183 memcpy(query_shm + sizeof(*cq), query->data, query->size);
184 ret = shm_detach(query_shm);
185 if (ret < 0)
186 goto out;
187
188 *(uint32_t *) buf = afs_socket_cookie;
189 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
190
191 ret = create_remote_socket(conf.afs_socket_arg);
192 if (ret < 0)
193 goto out;
194 fd = ret;
195 ret = send_bin_buffer(fd, buf, sizeof(buf));
196 if (ret < 0)
197 goto out;
198 ret = recv_bin_buffer(fd, buf, sizeof(buf));
199 if (ret < 0)
200 goto out;
201 if (ret != sizeof(int)) {
202 ret = -E_AFS_SHORT_READ;
203 goto out;
204 }
205 ret = *(int *) buf;
206 if (ret <= 0)
207 goto out;
208 result_shmid = ret;
209 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
210 if (ret >= 0) {
211 assert(result);
212 cr = result_shm;
213 result->size = cr->result_size;
214 result->data = para_malloc(result->size);
215 memcpy(result->data, result_shm + sizeof(*cr), result->size);
216 ret = shm_detach(result_shm);
217 if (ret < 0)
218 PARA_ERROR_LOG("can not detach result\n");
219 } else
220 PARA_ERROR_LOG("attach result failed: %d\n", ret);
221 if (shm_destroy(result_shmid) < 0)
222 PARA_ERROR_LOG("destroy result failed\n");
223 ret = 1;
224 out:
225 if (shm_destroy(query_shmid) < 0)
226 PARA_ERROR_LOG("%s\n", "shm destroy error");
227 if (fd >= 0)
228 close(fd);
229 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
230 return ret;
231 }
232
233 /**
234 * Send a callback request passing an options structure and an argument vector.
235 *
236 * \param options pointer to an arbitrary data structure.
237 * \param argc Argument count.
238 * \param argv Standard argument vector.
239 * \param f The callback function.
240 * \param result The result of the query is stored here.
241 *
242 * Some commands have a couple of options that are parsed in child context for
243 * syntactic correctness and are stored in a special options structure for that
244 * command. This function allows to pass such a structure together with a list
245 * of further arguments (often a list of audio files) to the parent process.
246 *
247 * \sa send_standard_callback_request(), send_callback_request().
248 */
249 int send_option_arg_callback_request(struct osl_object *options,
250 int argc, char * const * const argv, callback_function *f,
251 struct osl_object *result)
252 {
253 char *p;
254 int i, ret;
255 struct osl_object query = {.size = options? options->size : 0};
256
257 for (i = 0; i < argc; i++)
258 query.size += strlen(argv[i]) + 1;
259 query.data = para_malloc(query.size);
260 p = query.data;
261 if (options) {
262 memcpy(query.data, options->data, options->size);
263 p += options->size;
264 }
265 for (i = 0; i < argc; i++) {
266 strcpy(p, argv[i]); /* OK */
267 p += strlen(argv[i]) + 1;
268 }
269 ret = send_callback_request(f, &query, result);
270 free(query.data);
271 return ret;
272 }
273
274 /**
275 * Send a callback request with an argument vector only.
276 *
277 * \param argc The same meaning as in send_option_arg_callback_request().
278 * \param argv The same meaning as in send_option_arg_callback_request().
279 * \param f The same meaning as in send_option_arg_callback_request().
280 * \param result The same meaning as in send_option_arg_callback_request().
281 *
282 * This is similar to send_option_arg_callback_request(), but no options buffer
283 * is passed to the parent process.
284 *
285 * \return The return value of the underlying call to
286 * send_option_arg_callback_request().
287 */
288 int send_standard_callback_request(int argc, char * const * const argv,
289 callback_function *f, struct osl_object *result)
290 {
291 return send_option_arg_callback_request(NULL, argc, argv, f, result);
292 }
293
294 static int action_if_pattern_matches(struct osl_row *row, void *data)
295 {
296 struct pattern_match_data *pmd = data;
297 struct osl_object name_obj;
298 const char *p, *name;
299 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
300 const char *pattern_txt = (const char *)pmd->patterns.data;
301
302 if (ret < 0)
303 return ret;
304 name = (char *)name_obj.data;
305 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
306 return 1;
307 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
308 return pmd->action(pmd->table, row, name, pmd->data);
309 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
310 p += strlen(p) + 1) {
311 ret = fnmatch(p, name, pmd->fnmatch_flags);
312 if (ret == FNM_NOMATCH)
313 continue;
314 if (ret)
315 return -E_FNMATCH;
316 return pmd->action(pmd->table, row, name, pmd->data);
317 }
318 return 1;
319 }
320
321 /**
322 * Execute the given function for each matching row.
323 *
324 * \param pmd Describes what to match and how.
325 *
326 * \return The return value of the underlying call to osl_rbtree_loop()
327 * or osl_rbtree_loop_reverse().
328 */
329 int for_each_matching_row(struct pattern_match_data *pmd)
330 {
331 if (pmd->pm_flags & PM_REVERSE_LOOP)
332 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
333 action_if_pattern_matches);
334 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
335 action_if_pattern_matches);
336 }
337
338 /**
339 * Compare two osl objects of string type.
340 *
341 * \param obj1 Pointer to the first object.
342 * \param obj2 Pointer to the second object.
343 *
344 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
345 * are taken into account.
346 *
347 * \return It returns an integer less than, equal to, or greater than zero if
348 * \a obj1 is found, respectively, to be less than, to match, or be greater than
349 * obj2.
350 *
351 * \sa strcmp(3), strncmp(3), osl_compare_func.
352 */
353 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
354 {
355 const char *str1 = (const char *)obj1->data;
356 const char *str2 = (const char *)obj2->data;
357 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
358 }
359
360 /*
361 * write input from fd to dynamically allocated buffer,
362 * but maximal max_size byte.
363 */
364 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
365 {
366 const size_t chunk_size = 1024;
367 size_t size = 2048, received = 0;
368 int ret;
369 char *buf = para_malloc(size);
370
371 for (;;) {
372 ret = recv_bin_buffer(fd, buf + received, chunk_size);
373 if (ret <= 0)
374 break;
375 received += ret;
376 if (received + chunk_size >= size) {
377 size *= 2;
378 ret = -E_INPUT_TOO_LARGE;
379 if (size > max_size)
380 break;
381 buf = para_realloc(buf, size);
382 }
383 }
384 obj->data = buf;
385 obj->size = received;
386 if (ret < 0)
387 free(buf);
388 return ret;
389 }
390
391 /**
392 * Read data from a file descriptor, and send it to the afs process.
393 *
394 * \param fd File descriptor to read data from.
395 * \param arg_obj Pointer to the arguments to \a f.
396 * \param f The callback function.
397 * \param max_len Don't read more than that many bytes from stdin.
398 * \param result The result of the query is stored here.
399 *
400 * This function is used by commands that wish to let para_server store
401 * arbitrary data specified by the user (for instance the add_blob family of
402 * commands). First, at most \a max_len bytes are read from \a fd, the result
403 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
404 * is made available to the parent process via shared memory.
405 *
406 * \return Negative on errors, the return value of the underlying call to
407 * send_callback_request() otherwise.
408 */
409 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
410 unsigned max_len, struct osl_object *result)
411 {
412 struct osl_object query, stdin_obj;
413 int ret;
414
415 ret = send_buffer(fd, AWAITING_DATA_MSG);
416 if (ret < 0)
417 return ret;
418 ret = fd2buf(fd, max_len, &stdin_obj);
419 if (ret < 0)
420 return ret;
421 query.size = arg_obj->size + stdin_obj.size;
422 query.data = para_malloc(query.size);
423 memcpy(query.data, arg_obj->data, arg_obj->size);
424 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
425 free(stdin_obj.data);
426 ret = send_callback_request(f, &query, result);
427 free(query.data);
428 return ret;
429 }
430
431 static int pass_afd(int fd, char *buf, size_t size)
432 {
433 struct msghdr msg = {.msg_iov = NULL};
434 struct cmsghdr *cmsg;
435 char control[255];
436 int ret;
437 struct iovec iov;
438
439 iov.iov_base = buf;
440 iov.iov_len = size;
441
442 msg.msg_iov = &iov;
443 msg.msg_iovlen = 1;
444
445 msg.msg_control = control;
446 msg.msg_controllen = sizeof(control);
447
448 cmsg = CMSG_FIRSTHDR(&msg);
449 cmsg->cmsg_level = SOL_SOCKET;
450 cmsg->cmsg_type = SCM_RIGHTS;
451 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
452 *(int *)CMSG_DATA(cmsg) = fd;
453
454 /* Sum of the length of all control messages in the buffer */
455 msg.msg_controllen = cmsg->cmsg_len;
456 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
457 ret = sendmsg(server_socket, &msg, 0);
458 if (ret < 0) {
459 ret = -ERRNO_TO_PARA_ERROR(errno);
460 return ret;
461 }
462 return 1;
463 }
464
465 /**
466 * Open the audio file with highest score.
467 *
468 * This stores all information for streaming the "best" audio file in a shared
469 * memory area. The id of that area and an open file descriptor for the next
470 * audio file are passed to the server process.
471 *
472 * \return Standard.
473 *
474 * \sa open_and_update_audio_file().
475 */
476 int open_next_audio_file(void)
477 {
478 struct osl_row *aft_row;
479 struct audio_file_data afd;
480 int ret, shmid;
481 char buf[8];
482 long score;
483 again:
484 PARA_NOTICE_LOG("getting next audio file\n");
485 ret = score_get_best(&aft_row, &score);
486 if (ret < 0) {
487 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
488 goto no_admissible_files;
489 }
490 ret = open_and_update_audio_file(aft_row, score, &afd);
491 if (ret < 0) {
492 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
493 ret = score_delete(aft_row);
494 if (ret < 0) {
495 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
496 goto no_admissible_files;
497 }
498 goto again;
499 }
500 shmid = ret;
501 if (!write_ok(server_socket)) {
502 ret = -E_AFS_SOCKET;
503 goto destroy;
504 }
505 *(uint32_t *)buf = NEXT_AUDIO_FILE;
506 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
507 ret = pass_afd(afd.fd, buf, 8);
508 close(afd.fd);
509 if (ret >= 0)
510 return ret;
511 destroy:
512 shm_destroy(shmid);
513 return ret;
514 no_admissible_files:
515 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
516 *(uint32_t *)(buf + 4) = (uint32_t)0;
517 return send_bin_buffer(server_socket, buf, 8);
518 }
519
520 /* Never fails if arg == NULL */
521 static int activate_mood_or_playlist(char *arg, int *num_admissible)
522 {
523 enum play_mode mode;
524 int ret;
525
526 if (!arg) {
527 ret = change_current_mood(NULL); /* always successful */
528 mode = PLAY_MODE_MOOD;
529 } else {
530 if (!strncmp(arg, "p/", 2)) {
531 ret = playlist_open(arg + 2);
532 mode = PLAY_MODE_PLAYLIST;
533 } else if (!strncmp(arg, "m/", 2)) {
534 ret = change_current_mood(arg + 2);
535 mode = PLAY_MODE_MOOD;
536 } else
537 return -E_AFS_SYNTAX;
538 if (ret < 0)
539 return ret;
540 }
541 if (num_admissible)
542 *num_admissible = ret;
543 current_play_mode = mode;
544 if (arg != current_mop) {
545 free(current_mop);
546 if (arg) {
547 current_mop = para_strdup(arg);
548 mmd_lock();
549 strncpy(mmd->afs_mode_string, arg,
550 sizeof(mmd->afs_mode_string));
551 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
552 mmd_unlock();
553 } else {
554 mmd_lock();
555 strcpy(mmd->afs_mode_string, "dummy");
556 mmd_unlock();
557 current_mop = NULL;
558 }
559 }
560 return 1;
561 }
562
563 static int com_select_callback(const struct osl_object *query,
564 struct osl_object *result)
565 {
566 struct para_buffer pb = {.buf = NULL};
567 char *arg = query->data;
568 int num_admissible, ret;
569
570 ret = clear_score_table();
571 if (ret < 0)
572 return ret;
573 if (current_play_mode == PLAY_MODE_MOOD)
574 close_current_mood();
575 else
576 playlist_close();
577 ret = activate_mood_or_playlist(arg, &num_admissible);
578 if (ret < 0) {
579 para_printf(&pb, "%s\n", para_strerror(-ret));
580 para_printf(&pb, "switching back to %s\n", current_mop?
581 current_mop : "dummy");
582 ret = activate_mood_or_playlist(current_mop, &num_admissible);
583 if (ret < 0) {
584 para_printf(&pb, "failed, switching to dummy\n");
585 activate_mood_or_playlist(NULL, &num_admissible);
586 }
587 }
588 para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
589 current_mop : "dummy mood", num_admissible);
590 result->data = pb.buf;
591 result->size = pb.size;
592 return 1;
593 }
594
595 int com_select(int fd, int argc, char * const * const argv)
596 {
597 int ret;
598 struct osl_object query, result;
599
600 if (argc != 2)
601 return -E_AFS_SYNTAX;
602 query.data = argv[1];
603 query.size = strlen(argv[1]) + 1;
604 ret = send_callback_request(com_select_callback, &query,
605 &result);
606 if (ret > 0 && result.data && result.size) {
607 ret = send_va_buffer(fd, "%s", (char *)result.data);
608 free(result.data);
609 }
610 return ret;
611 }
612
613 static void init_admissible_files(char *arg)
614 {
615 if (activate_mood_or_playlist(arg, NULL) < 0)
616 activate_mood_or_playlist(NULL, NULL); /* always successful */
617 }
618
619 static int setup_command_socket_or_die(void)
620 {
621 int ret, socket_fd;
622 char *socket_name = conf.afs_socket_arg;
623 struct sockaddr_un unix_addr;
624
625 unlink(socket_name);
626 ret = create_local_socket(socket_name, &unix_addr,
627 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
628 if (ret < 0) {
629 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
630 exit(EXIT_FAILURE);
631 }
632 socket_fd = ret;
633 if (listen(socket_fd , 5) < 0) {
634 PARA_EMERG_LOG("can not listen on socket\n");
635 exit(EXIT_FAILURE);
636 }
637 ret = mark_fd_nonblocking(socket_fd);
638 if (ret < 0) {
639 close(socket_fd);
640 return ret;
641 }
642 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name, ret);
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", 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 void unregister_tasks(void)
705 {
706 unregister_task(&command_task_struct.task);
707 unregister_task(&signal_task_struct.task);
708 }
709
710 static void signal_pre_select(struct sched *s, struct task *t)
711 {
712 struct signal_task *st = t->private_data;
713 t->ret = 1;
714 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
715 }
716
717 static void signal_post_select(struct sched *s, struct task *t)
718 {
719 struct signal_task *st = t->private_data;
720 t->ret = -E_AFS_PARENT_DIED;
721 if (getppid() == 1)
722 goto err;
723 t->ret = 1;
724 if (!FD_ISSET(st->fd, &s->rfds))
725 return;
726 st->signum = para_next_signal();
727 t->ret = 1;
728 if (st->signum == SIGUSR1)
729 return; /* ignore SIGUSR1 */
730 if (st->signum == SIGHUP) {
731 close_afs_tables();
732 t->ret = open_afs_tables();
733 if (t->ret < 0)
734 goto err;
735 init_admissible_files(current_mop);
736 return;
737 }
738 t->ret = -E_AFS_SIGNAL;
739 err:
740 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
741 unregister_tasks();
742 }
743
744 static void register_signal_task(void)
745 {
746 struct signal_task *st = &signal_task_struct;
747 st->fd = para_signal_init();
748 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
749 para_install_sighandler(SIGINT);
750 para_install_sighandler(SIGTERM);
751 para_install_sighandler(SIGPIPE);
752 para_install_sighandler(SIGHUP);
753
754 st->task.pre_select = signal_pre_select;
755 st->task.post_select = signal_post_select;
756 st->task.private_data = st;
757 sprintf(st->task.status, "signal task");
758 register_task(&st->task);
759 }
760
761 static struct list_head afs_client_list;
762
763 /** Describes on connected afs client. */
764 struct afs_client {
765 /** Position in the afs client list. */
766 struct list_head node;
767 /** The socket file descriptor for this client. */
768 int fd;
769 /** The time the client connected. */
770 struct timeval connect_time;
771 };
772
773 static void command_pre_select(struct sched *s, struct task *t)
774 {
775 struct command_task *ct = t->private_data;
776 struct afs_client *client;
777
778 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
779 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
780 list_for_each_entry(client, &afs_client_list, node)
781 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
782 t->ret = 1;
783 }
784
785 /*
786 * On errors, negative value is written to fd.
787 * On success: If query produced a result, the result_shmid is written to fd.
788 * Otherwise, zero is written.
789 */
790 static int call_callback(int fd, int query_shmid)
791 {
792 void *query_shm, *result_shm;
793 struct callback_query *cq;
794 struct callback_result *cr;
795 struct osl_object query, result = {.data = NULL};
796 int result_shmid = -1, ret, ret2;
797
798 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
799 if (ret < 0)
800 goto out;
801 cq = query_shm;
802 query.data = (char *)query_shm + sizeof(*cq);
803 query.size = cq->query_size;
804 ret = cq->handler(&query, &result);
805 ret2 = shm_detach(query_shm);
806 if (ret2 < 0 && ret >= 0)
807 ret = ret2;
808 if (ret < 0)
809 goto out;
810 ret = 0;
811 if (!result.data || !result.size)
812 goto out;
813 ret = shm_new(result.size + sizeof(struct callback_result));
814 if (ret < 0)
815 goto out;
816 result_shmid = ret;
817 ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
818 if (ret < 0)
819 goto out;
820 cr = result_shm;
821 cr->result_size = result.size;
822 memcpy(result_shm + sizeof(*cr), result.data, result.size);
823 ret = shm_detach(result_shm);
824 if (ret < 0)
825 goto out;
826 ret = result_shmid;
827 out:
828 free(result.data);
829 ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int));
830 if (ret < 0 || ret2 < 0) {
831 if (result_shmid >= 0)
832 if (shm_destroy(result_shmid) < 0)
833 PARA_ERROR_LOG("destroy result failed\n");
834 if (ret >= 0)
835 ret = ret2;
836 }
837 return ret;
838 }
839
840 static void execute_server_command(void)
841 {
842 char buf[8];
843 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
844
845 if (ret <= 0) {
846 if (ret < 0)
847 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
848 return;
849 }
850 buf[ret] = '\0';
851 PARA_DEBUG_LOG("received: %s\n", buf);
852 if (!strcmp(buf, "new")) {
853 ret = open_next_audio_file();
854 if (ret < 0) {
855 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
856 unregister_tasks();
857 }
858 return;
859 }
860 PARA_ERROR_LOG("unknown command\n");
861
862 }
863
864 static void execute_afs_command(int fd, uint32_t expected_cookie)
865 {
866 uint32_t cookie;
867 int query_shmid;
868 char buf[sizeof(cookie) + sizeof(query_shmid)];
869 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
870
871 if (ret < 0) {
872 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
873 return;
874 }
875 if (ret != sizeof(buf)) {
876 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
877 ret, (long unsigned) sizeof(buf));
878 return;
879 }
880 cookie = *(uint32_t *)buf;
881 if (cookie != expected_cookie) {
882 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
883 (unsigned)cookie, (unsigned)expected_cookie);
884 return;
885 }
886 query_shmid = *(int *)(buf + sizeof(cookie));
887 if (query_shmid < 0) {
888 PARA_WARNING_LOG("received invalid query shmid %d)\n",
889 query_shmid);
890 return;
891 }
892 /* Ignore return value: Errors might be OK here. */
893 call_callback(fd, query_shmid);
894 }
895
896 /** Shutdown connection if query has not arrived until this many seconds. */
897 #define AFS_CLIENT_TIMEOUT 3
898
899 static void command_post_select(struct sched *s, struct task *t)
900 {
901 struct command_task *ct = t->private_data;
902 struct sockaddr_un unix_addr;
903 struct afs_client *client, *tmp;
904 int fd;
905 if (FD_ISSET(server_socket, &s->rfds))
906 execute_server_command();
907
908 /* Check the list of connected clients. */
909 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
910 if (FD_ISSET(client->fd, &s->rfds))
911 execute_afs_command(client->fd, ct->cookie);
912 else { /* prevent bogus connection flooding */
913 struct timeval diff;
914 tv_diff(now, &client->connect_time, &diff);
915 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
916 continue;
917 PARA_WARNING_LOG("connection timeout\n");
918 }
919 close(client->fd);
920 list_del(&client->node);
921 free(client);
922 }
923 /* Accept connections on the local socket. */
924 if (!FD_ISSET(ct->fd, &s->rfds))
925 goto out;
926 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
927 if (t->ret < 0) {
928 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
929 goto out;
930 }
931 fd = t->ret;
932 t->ret = mark_fd_nonblocking(fd);
933 if (t->ret < 0) {
934 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
935 close(fd);
936 goto out;
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 out:
943 t->ret = 1;
944 }
945
946 static void register_command_task(uint32_t cookie)
947 {
948 struct command_task *ct = &command_task_struct;
949 ct->fd = setup_command_socket_or_die();
950 ct->cookie = cookie;
951
952 ct->task.pre_select = command_pre_select;
953 ct->task.post_select = command_post_select;
954 ct->task.private_data = ct;
955 sprintf(ct->task.status, "command task");
956 register_task(&ct->task);
957 }
958
959 static void register_tasks(uint32_t cookie)
960 {
961 register_signal_task();
962 register_command_task(cookie);
963 }
964
965 /**
966 * Initialize the audio file selector process.
967 *
968 * \param cookie The value used for "authentication".
969 * \param socket_fd File descriptor used for communication with the server.
970 */
971 __noreturn void afs_init(uint32_t cookie, int socket_fd)
972 {
973 struct sched s;
974 int i, ret;
975
976 INIT_LIST_HEAD(&afs_client_list);
977 for (i = 0; i < NUM_AFS_TABLES; i++)
978 afs_tables[i].init(&afs_tables[i]);
979 ret = open_afs_tables();
980
981 if (ret < 0) {
982 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
983 exit(EXIT_FAILURE);
984 }
985 server_socket = socket_fd;
986 ret = mark_fd_nonblocking(server_socket);
987 if (ret < 0)
988 exit(EXIT_FAILURE);
989 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
990 server_socket, (unsigned) cookie);
991 init_admissible_files(conf.afs_initial_mode_arg);
992 register_tasks(cookie);
993 s.default_timeout.tv_sec = 0;
994 s.default_timeout.tv_usec = 999 * 1000;
995 ret = schedule(&s);
996 if (ret < 0)
997 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
998 close_afs_tables();
999 exit(EXIT_FAILURE);
1000 }
1001
1002 static int create_tables_callback(const struct osl_object *query,
1003 __a_unused struct osl_object *result)
1004 {
1005 uint32_t table_mask = *(uint32_t *)query->data;
1006 int i, ret;
1007
1008 close_afs_tables();
1009 for (i = 0; i < NUM_AFS_TABLES; i++) {
1010 struct afs_table *t = &afs_tables[i];
1011
1012 if (!(table_mask & (1 << i)))
1013 continue;
1014 if (!t->create)
1015 continue;
1016 ret = t->create(database_dir);
1017 if (ret < 0)
1018 return ret;
1019 }
1020 ret = open_afs_tables();
1021 return ret < 0? ret: 0;
1022 }
1023
1024 int com_init(int fd, int argc, char * const * const argv)
1025 {
1026 int i, j, ret;
1027 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1028 struct osl_object query = {.data = &table_mask,
1029 .size = sizeof(table_mask)};
1030
1031 ret = make_database_dir();
1032 if (ret < 0)
1033 return ret;
1034 if (argc != 1) {
1035 table_mask = 0;
1036 for (i = 1; i < argc; i++) {
1037 for (j = 0; j < NUM_AFS_TABLES; j++) {
1038 struct afs_table *t = &afs_tables[j];
1039
1040 if (strcmp(argv[i], t->name))
1041 continue;
1042 table_mask |= (1 << j);
1043 break;
1044 }
1045 if (j == NUM_AFS_TABLES)
1046 return -E_BAD_TABLE_NAME;
1047 }
1048 }
1049 ret = send_callback_request(create_tables_callback, &query, NULL);
1050 if (ret < 0)
1051 return ret;
1052 return send_va_buffer(fd, "successfully created afs table(s)\n");
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(int fd, int argc, char * const * const argv)
1070 {
1071 unsigned flags = 0;
1072 int i, ret;
1073 struct osl_object result;
1074
1075 for (i = 1; i < argc; i++) {
1076 const char *arg = argv[i];
1077 if (arg[0] != '-')
1078 break;
1079 if (!strcmp(arg, "--")) {
1080 i++;
1081 break;
1082 }
1083 if (!strcmp(arg, "-a")) {
1084 flags |= CHECK_AFT;
1085 continue;
1086 }
1087 if (!strcmp(arg, "-p")) {
1088 flags |= CHECK_PLAYLISTS;
1089 continue;
1090 }
1091 if (!strcmp(arg, "-m")) {
1092 flags |= CHECK_MOODS;
1093 continue;
1094 }
1095 return -E_AFS_SYNTAX;
1096 }
1097 if (i < argc)
1098 return -E_AFS_SYNTAX;
1099 if (!flags)
1100 flags = ~0U;
1101 if (flags & CHECK_AFT) {
1102 ret = send_callback_request(aft_check_callback, NULL, &result);
1103 if (ret < 0)
1104 return ret;
1105 if (ret > 0) {
1106 ret = send_buffer(fd, (char *) result.data);
1107 free(result.data);
1108 if (ret < 0)
1109 return ret;
1110 }
1111 }
1112 if (flags & CHECK_PLAYLISTS) {
1113 ret = send_callback_request(playlist_check_callback, NULL, &result);
1114 if (ret < 0)
1115 return ret;
1116 if (ret > 0) {
1117 ret = send_buffer(fd, (char *) result.data);
1118 free(result.data);
1119 if (ret < 0)
1120 return ret;
1121 }
1122 }
1123 if (flags & CHECK_MOODS) {
1124 ret = send_callback_request(mood_check_callback, NULL, &result);
1125 if (ret < 0)
1126 return ret;
1127 if (ret > 0) {
1128 ret = send_buffer(fd, (char *) result.data);
1129 free(result.data);
1130 if (ret < 0)
1131 return ret;
1132 }
1133 }
1134 return 1;
1135 }
1136
1137 void afs_event(enum afs_events event, struct para_buffer *pb,
1138 void *data)
1139 {
1140 int i, ret;
1141
1142 for (i = 0; i < NUM_AFS_TABLES; i++) {
1143 struct afs_table *t = &afs_tables[i];
1144 if (!t->event_handler)
1145 continue;
1146 ret = t->event_handler(event, pb, data);
1147 if (ret < 0)
1148 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1149 }
1150 }
1151
1152 int images_event_handler(__a_unused enum afs_events event,
1153 __a_unused struct para_buffer *pb, __a_unused void *data)
1154 {
1155 return 1;
1156 }
1157
1158 int lyrics_event_handler(__a_unused enum afs_events event,
1159 __a_unused struct para_buffer *pb, __a_unused void *data)
1160 {
1161 return 1;
1162 }