Complete the afs callback conversion.
[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 * \a 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 callback_result_handler *result_handler,
161 void *private_result_data)
162 {
163 struct callback_query *cq;
164 int num_results = 0, 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 for (;;) {
199 ret = recv_bin_buffer(fd, buf, sizeof(int));
200 if (ret <= 0)
201 goto out;
202 if (ret != sizeof(int)) {
203 ret = -E_AFS_SHORT_READ;
204 goto out;
205 }
206 ret = *(int *) buf;
207 if (ret <= 0)
208 goto out;
209 result_shmid = ret;
210 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
211 if (ret >= 0) {
212 struct callback_result *cr = result_shm;
213 struct osl_object result;
214 num_results++;
215 result.size = cr->result_size;
216 result.data = result_shm + sizeof(*cr);
217 if (result.size) {
218 assert(result_handler);
219 ret = result_handler(&result, private_result_data);
220 if (shm_detach(result_shm) < 0)
221 PARA_ERROR_LOG("can not detach result\n");
222 }
223 } else
224 PARA_ERROR_LOG("attach result failed: %d\n", ret);
225 if (shm_destroy(result_shmid) < 0)
226 PARA_ERROR_LOG("destroy result failed\n");
227 if (ret < 0)
228 break;
229 }
230 out:
231 if (shm_destroy(query_shmid) < 0)
232 PARA_ERROR_LOG("%s\n", "shm destroy error");
233 if (fd >= 0)
234 close(fd);
235 if (ret >= 0)
236 ret = num_results;
237 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
238 return ret;
239 }
240
241 /**
242 * Send a callback request passing an options structure and an argument vector.
243 *
244 * \param options pointer to an arbitrary data structure.
245 * \param argc Argument count.
246 * \param argv Standard argument vector.
247 * \param f The callback function.
248 * \param result The result of the query is stored here.
249 *
250 * Some commands have a couple of options that are parsed in child context for
251 * syntactic correctness and are stored in a special options structure for that
252 * command. This function allows to pass such a structure together with a list
253 * of further arguments (often a list of audio files) to the parent process.
254 *
255 * \sa send_standard_callback_request(), send_callback_request().
256 */
257 int send_option_arg_callback_request(struct osl_object *options,
258 int argc, char * const * const argv, callback_function *f,
259 callback_result_handler *result_handler,
260 void *private_result_data)
261 {
262 char *p;
263 int i, ret;
264 struct osl_object query = {.size = options? options->size : 0};
265
266 for (i = 0; i < argc; i++)
267 query.size += strlen(argv[i]) + 1;
268 query.data = para_malloc(query.size);
269 p = query.data;
270 if (options) {
271 memcpy(query.data, options->data, options->size);
272 p += options->size;
273 }
274 for (i = 0; i < argc; i++) {
275 strcpy(p, argv[i]); /* OK */
276 p += strlen(argv[i]) + 1;
277 }
278 ret = send_callback_request(f, &query, result_handler,
279 private_result_data);
280 free(query.data);
281 return ret;
282 }
283
284 /**
285 * Send a callback request with an argument vector only.
286 *
287 * \param argc The same meaning as in send_option_arg_callback_request().
288 * \param argv The same meaning as in send_option_arg_callback_request().
289 * \param f The same meaning as in send_option_arg_callback_request().
290 * \param result The same meaning as in send_option_arg_callback_request().
291 *
292 * This is similar to send_option_arg_callback_request(), but no options buffer
293 * is passed to the parent process.
294 *
295 * \return The return value of the underlying call to
296 * send_option_arg_callback_request().
297 */
298 int send_standard_callback_request(int argc, char * const * const argv,
299 callback_function *f, callback_result_handler *result_handler,
300 void *private_result_data)
301 {
302 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
303 private_result_data);
304 }
305
306 static int action_if_pattern_matches(struct osl_row *row, void *data)
307 {
308 struct pattern_match_data *pmd = data;
309 struct osl_object name_obj;
310 const char *p, *name;
311 int ret = osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj);
312 const char *pattern_txt = (const char *)pmd->patterns.data;
313
314 if (ret < 0)
315 return ret;
316 name = (char *)name_obj.data;
317 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
318 return 1;
319 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
320 return pmd->action(pmd->table, row, name, pmd->data);
321 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
322 p += strlen(p) + 1) {
323 ret = fnmatch(p, name, pmd->fnmatch_flags);
324 if (ret == FNM_NOMATCH)
325 continue;
326 if (ret)
327 return -E_FNMATCH;
328 return pmd->action(pmd->table, row, name, pmd->data);
329 }
330 return 1;
331 }
332
333 /**
334 * Execute the given function for each matching row.
335 *
336 * \param pmd Describes what to match and how.
337 *
338 * \return The return value of the underlying call to osl_rbtree_loop()
339 * or osl_rbtree_loop_reverse().
340 */
341 int for_each_matching_row(struct pattern_match_data *pmd)
342 {
343 if (pmd->pm_flags & PM_REVERSE_LOOP)
344 return osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
345 action_if_pattern_matches);
346 return osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
347 action_if_pattern_matches);
348 }
349
350 /**
351 * Compare two osl objects of string type.
352 *
353 * \param obj1 Pointer to the first object.
354 * \param obj2 Pointer to the second object.
355 *
356 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
357 * are taken into account.
358 *
359 * \return It returns an integer less than, equal to, or greater than zero if
360 * \a obj1 is found, respectively, to be less than, to match, or be greater than
361 * obj2.
362 *
363 * \sa strcmp(3), strncmp(3), osl_compare_func.
364 */
365 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
366 {
367 const char *str1 = (const char *)obj1->data;
368 const char *str2 = (const char *)obj2->data;
369 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
370 }
371
372 /*
373 * write input from fd to dynamically allocated buffer,
374 * but maximal max_size byte.
375 */
376 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
377 {
378 const size_t chunk_size = 1024;
379 size_t size = 2048, received = 0;
380 int ret;
381 char *buf = para_malloc(size);
382
383 for (;;) {
384 ret = recv_bin_buffer(fd, buf + received, chunk_size);
385 if (ret <= 0)
386 break;
387 received += ret;
388 if (received + chunk_size >= size) {
389 size *= 2;
390 ret = -E_INPUT_TOO_LARGE;
391 if (size > max_size)
392 break;
393 buf = para_realloc(buf, size);
394 }
395 }
396 obj->data = buf;
397 obj->size = received;
398 if (ret < 0)
399 free(buf);
400 return ret;
401 }
402
403 /**
404 * Read data from a file descriptor, and send it to the afs process.
405 *
406 * \param fd File descriptor to read data from.
407 * \param arg_obj Pointer to the arguments to \a f.
408 * \param f The callback function.
409 * \param max_len Don't read more than that many bytes from stdin.
410 * \param result The result of the query is stored here.
411 *
412 * This function is used by commands that wish to let para_server store
413 * arbitrary data specified by the user (for instance the add_blob family of
414 * commands). First, at most \a max_len bytes are read from \a fd, the result
415 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
416 * is made available to the parent process via shared memory.
417 *
418 * \return Negative on errors, the return value of the underlying call to
419 * send_callback_request() otherwise.
420 */
421 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
422 unsigned max_len, callback_result_handler *result_handler,
423 void *private_result_data)
424 {
425 struct osl_object query, stdin_obj;
426 int ret;
427
428 ret = send_buffer(fd, AWAITING_DATA_MSG);
429 if (ret < 0)
430 return ret;
431 ret = fd2buf(fd, max_len, &stdin_obj);
432 if (ret < 0)
433 return ret;
434 query.size = arg_obj->size + stdin_obj.size;
435 query.data = para_malloc(query.size);
436 memcpy(query.data, arg_obj->data, arg_obj->size);
437 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
438 free(stdin_obj.data);
439 ret = send_callback_request(f, &query, result_handler, private_result_data);
440 free(query.data);
441 return ret;
442 }
443
444 static int pass_afd(int fd, char *buf, size_t size)
445 {
446 struct msghdr msg = {.msg_iov = NULL};
447 struct cmsghdr *cmsg;
448 char control[255];
449 int ret;
450 struct iovec iov;
451
452 iov.iov_base = buf;
453 iov.iov_len = size;
454
455 msg.msg_iov = &iov;
456 msg.msg_iovlen = 1;
457
458 msg.msg_control = control;
459 msg.msg_controllen = sizeof(control);
460
461 cmsg = CMSG_FIRSTHDR(&msg);
462 cmsg->cmsg_level = SOL_SOCKET;
463 cmsg->cmsg_type = SCM_RIGHTS;
464 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
465 *(int *)CMSG_DATA(cmsg) = fd;
466
467 /* Sum of the length of all control messages in the buffer */
468 msg.msg_controllen = cmsg->cmsg_len;
469 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
470 ret = sendmsg(server_socket, &msg, 0);
471 if (ret < 0) {
472 ret = -ERRNO_TO_PARA_ERROR(errno);
473 return ret;
474 }
475 return 1;
476 }
477
478 /**
479 * Open the audio file with highest score.
480 *
481 * This stores all information for streaming the "best" audio file in a shared
482 * memory area. The id of that area and an open file descriptor for the next
483 * audio file are passed to the server process.
484 *
485 * \return Standard.
486 *
487 * \sa open_and_update_audio_file().
488 */
489 int open_next_audio_file(void)
490 {
491 struct osl_row *aft_row;
492 struct audio_file_data afd;
493 int ret, shmid;
494 char buf[8];
495 long score;
496 again:
497 PARA_NOTICE_LOG("getting next audio file\n");
498 ret = score_get_best(&aft_row, &score);
499 if (ret < 0) {
500 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
501 goto no_admissible_files;
502 }
503 ret = open_and_update_audio_file(aft_row, score, &afd);
504 if (ret < 0) {
505 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
506 ret = score_delete(aft_row);
507 if (ret < 0) {
508 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
509 goto no_admissible_files;
510 }
511 goto again;
512 }
513 shmid = ret;
514 if (!write_ok(server_socket)) {
515 ret = -E_AFS_SOCKET;
516 goto destroy;
517 }
518 *(uint32_t *)buf = NEXT_AUDIO_FILE;
519 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
520 ret = pass_afd(afd.fd, buf, 8);
521 close(afd.fd);
522 if (ret >= 0)
523 return ret;
524 destroy:
525 shm_destroy(shmid);
526 return ret;
527 no_admissible_files:
528 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
529 *(uint32_t *)(buf + 4) = (uint32_t)0;
530 return send_bin_buffer(server_socket, buf, 8);
531 }
532
533 /* Never fails if arg == NULL */
534 static int activate_mood_or_playlist(char *arg, int *num_admissible)
535 {
536 enum play_mode mode;
537 int ret;
538
539 if (!arg) {
540 ret = change_current_mood(NULL); /* always successful */
541 mode = PLAY_MODE_MOOD;
542 } else {
543 if (!strncmp(arg, "p/", 2)) {
544 ret = playlist_open(arg + 2);
545 mode = PLAY_MODE_PLAYLIST;
546 } else if (!strncmp(arg, "m/", 2)) {
547 ret = change_current_mood(arg + 2);
548 mode = PLAY_MODE_MOOD;
549 } else
550 return -E_AFS_SYNTAX;
551 if (ret < 0)
552 return ret;
553 }
554 if (num_admissible)
555 *num_admissible = ret;
556 current_play_mode = mode;
557 if (arg != current_mop) {
558 free(current_mop);
559 if (arg) {
560 current_mop = para_strdup(arg);
561 mmd_lock();
562 strncpy(mmd->afs_mode_string, arg,
563 sizeof(mmd->afs_mode_string));
564 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
565 mmd_unlock();
566 } else {
567 mmd_lock();
568 strcpy(mmd->afs_mode_string, "dummy");
569 mmd_unlock();
570 current_mop = NULL;
571 }
572 }
573 return 1;
574 }
575
576 static void com_select_callback(int fd, const struct osl_object *query)
577 {
578 struct para_buffer pb = {
579 .max_size = SHMMAX,
580 .private_data = &fd,
581 .max_size_handler = pass_buffer_as_shm
582 };
583 char *arg = query->data;
584 int num_admissible, ret, ret2;
585
586 ret = clear_score_table();
587 if (ret < 0) {
588 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
589 goto out;
590 }
591 if (current_play_mode == PLAY_MODE_MOOD)
592 close_current_mood();
593 else
594 playlist_close();
595 ret = activate_mood_or_playlist(arg, &num_admissible);
596 if (ret < 0) {
597 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
598 para_strerror(-ret), current_mop?
599 current_mop : "dummy");
600 ret = activate_mood_or_playlist(current_mop, &num_admissible);
601 if (ret < 0) {
602 if (ret2 >= 0)
603 ret2 = para_printf(&pb, "failed, switching to dummy\n");
604 activate_mood_or_playlist(NULL, &num_admissible);
605 }
606 } else
607 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
608 current_mop : "dummy mood", num_admissible);
609 out:
610 if (ret2 >= 0 && pb.offset)
611 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
612 free(pb.buf);
613 }
614
615 int send_result(struct osl_object *result, void *private_result_data)
616 {
617 int fd = *(int *)private_result_data;
618 if (!result->size)
619 return 1;
620 return send_bin_buffer(fd, result->data, result->size);
621 }
622
623 int com_select(int fd, int argc, char * const * const argv)
624 {
625 struct osl_object query;
626
627 if (argc != 2)
628 return -E_AFS_SYNTAX;
629 query.data = argv[1];
630 query.size = strlen(argv[1]) + 1;
631 return send_callback_request(com_select_callback, &query,
632 &send_result, &fd);
633 }
634
635 static void init_admissible_files(char *arg)
636 {
637 if (activate_mood_or_playlist(arg, NULL) < 0)
638 activate_mood_or_playlist(NULL, NULL); /* always successful */
639 }
640
641 static int setup_command_socket_or_die(void)
642 {
643 int ret, socket_fd;
644 char *socket_name = conf.afs_socket_arg;
645 struct sockaddr_un unix_addr;
646
647 unlink(socket_name);
648 ret = create_local_socket(socket_name, &unix_addr,
649 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
650 if (ret < 0) {
651 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
652 exit(EXIT_FAILURE);
653 }
654 socket_fd = ret;
655 if (listen(socket_fd , 5) < 0) {
656 PARA_EMERG_LOG("can not listen on socket\n");
657 exit(EXIT_FAILURE);
658 }
659 ret = mark_fd_nonblocking(socket_fd);
660 if (ret < 0) {
661 close(socket_fd);
662 return ret;
663 }
664 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
665 socket_fd);
666 return socket_fd;
667 }
668
669 static void close_afs_tables(void)
670 {
671 int i;
672 PARA_NOTICE_LOG("closing afs_tables\n");
673 for (i = 0; i < NUM_AFS_TABLES; i++)
674 afs_tables[i].close();
675 }
676
677 static char *database_dir;
678
679 static void get_database_dir(void)
680 {
681 if (!database_dir) {
682 if (conf.afs_database_dir_given)
683 database_dir = para_strdup(conf.afs_database_dir_arg);
684 else {
685 char *home = para_homedir();
686 database_dir = make_message(
687 "%s/.paraslash/afs_database", home);
688 free(home);
689 }
690 }
691 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
692 }
693
694 static int make_database_dir(void)
695 {
696 int ret;
697
698 get_database_dir();
699 ret = para_mkdir(database_dir, 0777);
700 if (ret >= 0 || is_errno(-ret, EEXIST))
701 return 1;
702 return ret;
703 }
704
705 static int open_afs_tables(void)
706 {
707 int i, ret;
708
709 get_database_dir();
710 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
711 database_dir);
712 for (i = 0; i < NUM_AFS_TABLES; i++) {
713 ret = afs_tables[i].open(database_dir);
714 if (ret >= 0)
715 continue;
716 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
717 para_strerror(-ret));
718 break;
719 }
720 if (ret >= 0)
721 return ret;
722 while (i)
723 afs_tables[--i].close();
724 return ret;
725 }
726
727 static void unregister_tasks(void)
728 {
729 unregister_task(&command_task_struct.task);
730 unregister_task(&signal_task_struct.task);
731 }
732
733 static void signal_pre_select(struct sched *s, struct task *t)
734 {
735 struct signal_task *st = t->private_data;
736 t->ret = 1;
737 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
738 }
739
740 static void signal_post_select(struct sched *s, struct task *t)
741 {
742 struct signal_task *st = t->private_data;
743 t->ret = -E_AFS_PARENT_DIED;
744 if (getppid() == 1)
745 goto err;
746 t->ret = 1;
747 if (!FD_ISSET(st->fd, &s->rfds))
748 return;
749 st->signum = para_next_signal();
750 t->ret = 1;
751 if (st->signum == SIGUSR1)
752 return; /* ignore SIGUSR1 */
753 if (st->signum == SIGHUP) {
754 close_afs_tables();
755 t->ret = open_afs_tables();
756 if (t->ret < 0)
757 goto err;
758 init_admissible_files(current_mop);
759 return;
760 }
761 t->ret = -E_AFS_SIGNAL;
762 err:
763 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
764 unregister_tasks();
765 }
766
767 static void register_signal_task(void)
768 {
769 struct signal_task *st = &signal_task_struct;
770 st->fd = para_signal_init();
771 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
772 para_install_sighandler(SIGINT);
773 para_install_sighandler(SIGTERM);
774 para_install_sighandler(SIGPIPE);
775 para_install_sighandler(SIGHUP);
776
777 st->task.pre_select = signal_pre_select;
778 st->task.post_select = signal_post_select;
779 st->task.private_data = st;
780 sprintf(st->task.status, "signal task");
781 register_task(&st->task);
782 }
783
784 static struct list_head afs_client_list;
785
786 /** Describes on connected afs client. */
787 struct afs_client {
788 /** Position in the afs client list. */
789 struct list_head node;
790 /** The socket file descriptor for this client. */
791 int fd;
792 /** The time the client connected. */
793 struct timeval connect_time;
794 };
795
796 static void command_pre_select(struct sched *s, struct task *t)
797 {
798 struct command_task *ct = t->private_data;
799 struct afs_client *client;
800
801 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
802 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
803 list_for_each_entry(client, &afs_client_list, node)
804 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
805 t->ret = 1;
806 }
807
808 int pass_buffer_as_shm(char *buf, size_t size, void *private_data)
809 {
810 int ret, shmid, fd = *(int *)private_data;
811 void *shm;
812 struct callback_result *cr;
813
814 if (!buf || !size)
815 return 0;
816 ret = shm_new(size + sizeof(struct callback_result));
817 if (ret < 0)
818 return ret;
819 shmid = ret;
820 ret = shm_attach(shmid, ATTACH_RW, &shm);
821 if (ret < 0)
822 goto err;
823 cr = shm;
824 cr->result_size = size;
825 memcpy(shm + sizeof(*cr), buf, size);
826 ret = shm_detach(shm);
827 if (ret < 0)
828 goto err;
829 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
830 if (ret >= 0)
831 return ret;
832 err:
833 if (shm_destroy(shmid) < 0)
834 PARA_ERROR_LOG("destroy result failed\n");
835 return ret;
836 }
837
838 /*
839 * On errors, negative value is written to fd.
840 * On success: If query produced a result, the result_shmid is written to fd.
841 * Otherwise, zero is written.
842 */
843 static int call_callback(int fd, int query_shmid)
844 {
845 void *query_shm;
846 struct callback_query *cq;
847 struct osl_object query;
848 int ret;
849
850 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
851 if (ret < 0)
852 return ret;
853 cq = query_shm;
854 query.data = (char *)query_shm + sizeof(*cq);
855 query.size = cq->query_size;
856 cq->handler(fd, &query);
857 return 1;
858 }
859
860 static void execute_server_command(void)
861 {
862 char buf[8];
863 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
864
865 if (ret <= 0) {
866 if (ret < 0)
867 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
868 return;
869 }
870 buf[ret] = '\0';
871 PARA_DEBUG_LOG("received: %s\n", buf);
872 if (!strcmp(buf, "new")) {
873 ret = open_next_audio_file();
874 if (ret < 0) {
875 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
876 unregister_tasks();
877 }
878 return;
879 }
880 PARA_ERROR_LOG("unknown command\n");
881
882 }
883
884 static void execute_afs_command(int fd, uint32_t expected_cookie)
885 {
886 uint32_t cookie;
887 int query_shmid;
888 char buf[sizeof(cookie) + sizeof(query_shmid)];
889 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
890
891 if (ret < 0)
892 goto err;
893 if (ret != sizeof(buf)) {
894 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
895 ret, (long unsigned) sizeof(buf));
896 return;
897 }
898 cookie = *(uint32_t *)buf;
899 if (cookie != expected_cookie) {
900 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
901 (unsigned)cookie, (unsigned)expected_cookie);
902 return;
903 }
904 query_shmid = *(int *)(buf + sizeof(cookie));
905 if (query_shmid < 0) {
906 PARA_WARNING_LOG("received invalid query shmid %d)\n",
907 query_shmid);
908 return;
909 }
910 ret = call_callback(fd, query_shmid);
911 if (ret >= 0)
912 return;
913 err:
914 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
915 }
916
917 /** Shutdown connection if query has not arrived until this many seconds. */
918 #define AFS_CLIENT_TIMEOUT 3
919
920 static void command_post_select(struct sched *s, struct task *t)
921 {
922 struct command_task *ct = t->private_data;
923 struct sockaddr_un unix_addr;
924 struct afs_client *client, *tmp;
925 int fd;
926 if (FD_ISSET(server_socket, &s->rfds))
927 execute_server_command();
928
929 /* Check the list of connected clients. */
930 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
931 if (FD_ISSET(client->fd, &s->rfds))
932 execute_afs_command(client->fd, ct->cookie);
933 else { /* prevent bogus connection flooding */
934 struct timeval diff;
935 tv_diff(now, &client->connect_time, &diff);
936 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
937 continue;
938 PARA_WARNING_LOG("connection timeout\n");
939 }
940 close(client->fd);
941 list_del(&client->node);
942 free(client);
943 }
944 /* Accept connections on the local socket. */
945 if (!FD_ISSET(ct->fd, &s->rfds))
946 goto out;
947 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
948 if (t->ret < 0) {
949 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
950 goto out;
951 }
952 fd = t->ret;
953 t->ret = mark_fd_nonblocking(fd);
954 if (t->ret < 0) {
955 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
956 close(fd);
957 goto out;
958 }
959 client = para_malloc(sizeof(*client));
960 client->fd = fd;
961 client->connect_time = *now;
962 para_list_add(&client->node, &afs_client_list);
963 out:
964 t->ret = 1;
965 }
966
967 static void register_command_task(uint32_t cookie)
968 {
969 struct command_task *ct = &command_task_struct;
970 ct->fd = setup_command_socket_or_die();
971 ct->cookie = cookie;
972
973 ct->task.pre_select = command_pre_select;
974 ct->task.post_select = command_post_select;
975 ct->task.private_data = ct;
976 sprintf(ct->task.status, "command task");
977 register_task(&ct->task);
978 }
979
980 static void register_tasks(uint32_t cookie)
981 {
982 register_signal_task();
983 register_command_task(cookie);
984 }
985
986 /**
987 * Initialize the audio file selector process.
988 *
989 * \param cookie The value used for "authentication".
990 * \param socket_fd File descriptor used for communication with the server.
991 */
992 __noreturn void afs_init(uint32_t cookie, int socket_fd)
993 {
994 struct sched s;
995 int i, ret;
996
997 INIT_LIST_HEAD(&afs_client_list);
998 for (i = 0; i < NUM_AFS_TABLES; i++)
999 afs_tables[i].init(&afs_tables[i]);
1000 ret = open_afs_tables();
1001
1002 if (ret < 0) {
1003 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1004 exit(EXIT_FAILURE);
1005 }
1006 server_socket = socket_fd;
1007 ret = mark_fd_nonblocking(server_socket);
1008 if (ret < 0)
1009 exit(EXIT_FAILURE);
1010 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1011 server_socket, (unsigned) cookie);
1012 init_admissible_files(conf.afs_initial_mode_arg);
1013 register_tasks(cookie);
1014 s.default_timeout.tv_sec = 0;
1015 s.default_timeout.tv_usec = 999 * 1000;
1016 ret = schedule(&s);
1017 if (ret < 0)
1018 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1019 close_afs_tables();
1020 exit(EXIT_FAILURE);
1021 }
1022
1023 static void create_tables_callback(int fd, const struct osl_object *query)
1024 {
1025 uint32_t table_mask = *(uint32_t *)query->data;
1026 int i, ret;
1027 char *buf;
1028
1029 close_afs_tables();
1030 for (i = 0; i < NUM_AFS_TABLES; i++) {
1031 struct afs_table *t = &afs_tables[i];
1032
1033 if (!(table_mask & (1 << i)))
1034 continue;
1035 if (!t->create)
1036 continue;
1037 ret = t->create(database_dir);
1038 if (ret < 0)
1039 goto out;
1040 }
1041 ret = open_afs_tables();
1042 out:
1043 if (ret >= 0)
1044 buf = make_message("successfully created afs table(s)\n");
1045 else
1046 buf = make_message("%s\n", para_strerror(-ret));
1047 pass_buffer_as_shm(buf, strlen(buf), &fd);
1048 free(buf);
1049 }
1050
1051 int com_init(int fd, int argc, char * const * const argv)
1052 {
1053 int i, j, ret;
1054 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1055 struct osl_object query = {.data = &table_mask,
1056 .size = sizeof(table_mask)};
1057
1058 ret = make_database_dir();
1059 if (ret < 0)
1060 return ret;
1061 if (argc != 1) {
1062 table_mask = 0;
1063 for (i = 1; i < argc; i++) {
1064 for (j = 0; j < NUM_AFS_TABLES; j++) {
1065 struct afs_table *t = &afs_tables[j];
1066
1067 if (strcmp(argv[i], t->name))
1068 continue;
1069 table_mask |= (1 << j);
1070 break;
1071 }
1072 if (j == NUM_AFS_TABLES)
1073 return -E_BAD_TABLE_NAME;
1074 }
1075 }
1076 ret = send_callback_request(create_tables_callback, &query, NULL, NULL);
1077 if (ret < 0)
1078 return send_va_buffer(fd, "%s\n", para_strerror(-ret));
1079 return ret;
1080 }
1081
1082 /**
1083 * Flags for the check command.
1084 *
1085 * \sa com_check().
1086 */
1087 enum com_check_flags {
1088 /** Check the audio file table. */
1089 CHECK_AFT = 1,
1090 /** Check the mood table. */
1091 CHECK_MOODS = 2,
1092 /** Check the playlist table. */
1093 CHECK_PLAYLISTS = 4
1094 };
1095
1096 int com_check(int fd, int argc, char * const * const argv)
1097 {
1098 unsigned flags = 0;
1099 int i, ret;
1100
1101 for (i = 1; i < argc; i++) {
1102 const char *arg = argv[i];
1103 if (arg[0] != '-')
1104 break;
1105 if (!strcmp(arg, "--")) {
1106 i++;
1107 break;
1108 }
1109 if (!strcmp(arg, "-a")) {
1110 flags |= CHECK_AFT;
1111 continue;
1112 }
1113 if (!strcmp(arg, "-p")) {
1114 flags |= CHECK_PLAYLISTS;
1115 continue;
1116 }
1117 if (!strcmp(arg, "-m")) {
1118 flags |= CHECK_MOODS;
1119 continue;
1120 }
1121 return -E_AFS_SYNTAX;
1122 }
1123 if (i < argc)
1124 return -E_AFS_SYNTAX;
1125 if (!flags)
1126 flags = ~0U;
1127 if (flags & CHECK_AFT) {
1128 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1129 if (ret < 0)
1130 return ret;
1131 }
1132 if (flags & CHECK_PLAYLISTS) {
1133 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1134 if (ret < 0)
1135 return ret;
1136 }
1137 if (flags & CHECK_MOODS) {
1138 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1139 if (ret < 0)
1140 return ret;
1141 }
1142 return 1;
1143 }
1144
1145 void afs_event(enum afs_events event, struct para_buffer *pb,
1146 void *data)
1147 {
1148 int i, ret;
1149
1150 for (i = 0; i < NUM_AFS_TABLES; i++) {
1151 struct afs_table *t = &afs_tables[i];
1152 if (!t->event_handler)
1153 continue;
1154 ret = t->event_handler(event, pb, data);
1155 if (ret < 0)
1156 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1157 }
1158 }
1159
1160 int images_event_handler(__a_unused enum afs_events event,
1161 __a_unused struct para_buffer *pb, __a_unused void *data)
1162 {
1163 return 1;
1164 }
1165
1166 int lyrics_event_handler(__a_unused enum afs_events event,
1167 __a_unused struct para_buffer *pb, __a_unused void *data)
1168 {
1169 return 1;
1170 }