Introduce pass_object_as_shm().
[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 int com_select_callback(const struct osl_object *query,
577 struct osl_object *result)
578 {
579 struct para_buffer pb = {.buf = NULL};
580 char *arg = query->data;
581 int num_admissible, ret;
582
583 ret = clear_score_table();
584 if (ret < 0)
585 return ret;
586 if (current_play_mode == PLAY_MODE_MOOD)
587 close_current_mood();
588 else
589 playlist_close();
590 ret = activate_mood_or_playlist(arg, &num_admissible);
591 if (ret < 0) {
592 para_printf(&pb, "%s\n", para_strerror(-ret));
593 para_printf(&pb, "switching back to %s\n", current_mop?
594 current_mop : "dummy");
595 ret = activate_mood_or_playlist(current_mop, &num_admissible);
596 if (ret < 0) {
597 para_printf(&pb, "failed, switching to dummy\n");
598 activate_mood_or_playlist(NULL, &num_admissible);
599 }
600 }
601 para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
602 current_mop : "dummy mood", num_admissible);
603 result->data = pb.buf;
604 result->size = pb.offset;
605 return 1;
606 }
607
608 int send_result(struct osl_object *result, void *private_result_data)
609 {
610 int fd = *(int *)private_result_data;
611 if (!result->size)
612 return 1;
613 return send_bin_buffer(fd, result->data, result->size);
614 }
615
616 int com_select(int fd, int argc, char * const * const argv)
617 {
618 struct osl_object query;
619
620 if (argc != 2)
621 return -E_AFS_SYNTAX;
622 query.data = argv[1];
623 query.size = strlen(argv[1]) + 1;
624 return send_callback_request(com_select_callback, &query,
625 &send_result, &fd);
626 }
627
628 static void init_admissible_files(char *arg)
629 {
630 if (activate_mood_or_playlist(arg, NULL) < 0)
631 activate_mood_or_playlist(NULL, NULL); /* always successful */
632 }
633
634 static int setup_command_socket_or_die(void)
635 {
636 int ret, socket_fd;
637 char *socket_name = conf.afs_socket_arg;
638 struct sockaddr_un unix_addr;
639
640 unlink(socket_name);
641 ret = create_local_socket(socket_name, &unix_addr,
642 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
643 if (ret < 0) {
644 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
645 exit(EXIT_FAILURE);
646 }
647 socket_fd = ret;
648 if (listen(socket_fd , 5) < 0) {
649 PARA_EMERG_LOG("can not listen on socket\n");
650 exit(EXIT_FAILURE);
651 }
652 ret = mark_fd_nonblocking(socket_fd);
653 if (ret < 0) {
654 close(socket_fd);
655 return ret;
656 }
657 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
658 socket_fd);
659 return socket_fd;
660 }
661
662 static void close_afs_tables(void)
663 {
664 int i;
665 PARA_NOTICE_LOG("closing afs_tables\n");
666 for (i = 0; i < NUM_AFS_TABLES; i++)
667 afs_tables[i].close();
668 }
669
670 static char *database_dir;
671
672 static void get_database_dir(void)
673 {
674 if (!database_dir) {
675 if (conf.afs_database_dir_given)
676 database_dir = para_strdup(conf.afs_database_dir_arg);
677 else {
678 char *home = para_homedir();
679 database_dir = make_message(
680 "%s/.paraslash/afs_database", home);
681 free(home);
682 }
683 }
684 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
685 }
686
687 static int make_database_dir(void)
688 {
689 int ret;
690
691 get_database_dir();
692 ret = para_mkdir(database_dir, 0777);
693 if (ret >= 0 || is_errno(-ret, EEXIST))
694 return 1;
695 return ret;
696 }
697
698 static int open_afs_tables(void)
699 {
700 int i, ret;
701
702 get_database_dir();
703 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
704 database_dir);
705 for (i = 0; i < NUM_AFS_TABLES; i++) {
706 ret = afs_tables[i].open(database_dir);
707 if (ret >= 0)
708 continue;
709 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
710 para_strerror(-ret));
711 break;
712 }
713 if (ret >= 0)
714 return ret;
715 while (i)
716 afs_tables[--i].close();
717 return ret;
718 }
719
720 static void unregister_tasks(void)
721 {
722 unregister_task(&command_task_struct.task);
723 unregister_task(&signal_task_struct.task);
724 }
725
726 static void signal_pre_select(struct sched *s, struct task *t)
727 {
728 struct signal_task *st = t->private_data;
729 t->ret = 1;
730 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
731 }
732
733 static void signal_post_select(struct sched *s, struct task *t)
734 {
735 struct signal_task *st = t->private_data;
736 t->ret = -E_AFS_PARENT_DIED;
737 if (getppid() == 1)
738 goto err;
739 t->ret = 1;
740 if (!FD_ISSET(st->fd, &s->rfds))
741 return;
742 st->signum = para_next_signal();
743 t->ret = 1;
744 if (st->signum == SIGUSR1)
745 return; /* ignore SIGUSR1 */
746 if (st->signum == SIGHUP) {
747 close_afs_tables();
748 t->ret = open_afs_tables();
749 if (t->ret < 0)
750 goto err;
751 init_admissible_files(current_mop);
752 return;
753 }
754 t->ret = -E_AFS_SIGNAL;
755 err:
756 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
757 unregister_tasks();
758 }
759
760 static void register_signal_task(void)
761 {
762 struct signal_task *st = &signal_task_struct;
763 st->fd = para_signal_init();
764 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
765 para_install_sighandler(SIGINT);
766 para_install_sighandler(SIGTERM);
767 para_install_sighandler(SIGPIPE);
768 para_install_sighandler(SIGHUP);
769
770 st->task.pre_select = signal_pre_select;
771 st->task.post_select = signal_post_select;
772 st->task.private_data = st;
773 sprintf(st->task.status, "signal task");
774 register_task(&st->task);
775 }
776
777 static struct list_head afs_client_list;
778
779 /** Describes on connected afs client. */
780 struct afs_client {
781 /** Position in the afs client list. */
782 struct list_head node;
783 /** The socket file descriptor for this client. */
784 int fd;
785 /** The time the client connected. */
786 struct timeval connect_time;
787 };
788
789 static void command_pre_select(struct sched *s, struct task *t)
790 {
791 struct command_task *ct = t->private_data;
792 struct afs_client *client;
793
794 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
795 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
796 list_for_each_entry(client, &afs_client_list, node)
797 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
798 t->ret = 1;
799 }
800
801 int pass_object_as_shm(int fd, struct osl_object *obj)
802 {
803 int ret, shmid;
804 void *shm;
805 struct callback_result *cr;
806
807 if (!obj->data || !obj->size)
808 return 0;
809 ret = shm_new(obj->size + sizeof(struct callback_result));
810 if (ret < 0)
811 return ret;
812 shmid = ret;
813 ret = shm_attach(shmid, ATTACH_RW, &shm);
814 if (ret < 0)
815 goto err;
816 cr = shm;
817 cr->result_size = obj->size;
818 memcpy(shm + sizeof(*cr), obj->data, obj->size);
819 ret = shm_detach(shm);
820 if (ret < 0)
821 goto err;
822 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
823 if (ret >= 0)
824 return ret;
825 err:
826 if (shm_destroy(shmid) < 0)
827 PARA_ERROR_LOG("destroy result failed\n");
828 return ret;
829 }
830
831 /*
832 * On errors, negative value is written to fd.
833 * On success: If query produced a result, the result_shmid is written to fd.
834 * Otherwise, zero is written.
835 */
836 static void call_callback(int fd, int query_shmid)
837 {
838 void *query_shm;
839 struct callback_query *cq;
840 struct osl_object query, result = {.data = NULL};
841 int ret;
842
843 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
844 if (ret < 0)
845 goto out;
846 cq = query_shm;
847 query.data = (char *)query_shm + sizeof(*cq);
848 query.size = cq->query_size;
849 ret = cq->handler(&query, &result);
850 if (ret < 0)
851 goto out;
852 ret = pass_object_as_shm(fd, &result);
853 out:
854 free(result.data);
855 if (ret < 0)
856 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
857 }
858
859 static void execute_server_command(void)
860 {
861 char buf[8];
862 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
863
864 if (ret <= 0) {
865 if (ret < 0)
866 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
867 return;
868 }
869 buf[ret] = '\0';
870 PARA_DEBUG_LOG("received: %s\n", buf);
871 if (!strcmp(buf, "new")) {
872 ret = open_next_audio_file();
873 if (ret < 0) {
874 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
875 unregister_tasks();
876 }
877 return;
878 }
879 PARA_ERROR_LOG("unknown command\n");
880
881 }
882
883 static void execute_afs_command(int fd, uint32_t expected_cookie)
884 {
885 uint32_t cookie;
886 int query_shmid;
887 char buf[sizeof(cookie) + sizeof(query_shmid)];
888 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
889
890 if (ret < 0) {
891 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
892 return;
893 }
894 if (ret != sizeof(buf)) {
895 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
896 ret, (long unsigned) sizeof(buf));
897 return;
898 }
899 cookie = *(uint32_t *)buf;
900 if (cookie != expected_cookie) {
901 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
902 (unsigned)cookie, (unsigned)expected_cookie);
903 return;
904 }
905 query_shmid = *(int *)(buf + sizeof(cookie));
906 if (query_shmid < 0) {
907 PARA_WARNING_LOG("received invalid query shmid %d)\n",
908 query_shmid);
909 return;
910 }
911 call_callback(fd, query_shmid);
912 }
913
914 /** Shutdown connection if query has not arrived until this many seconds. */
915 #define AFS_CLIENT_TIMEOUT 3
916
917 static void command_post_select(struct sched *s, struct task *t)
918 {
919 struct command_task *ct = t->private_data;
920 struct sockaddr_un unix_addr;
921 struct afs_client *client, *tmp;
922 int fd;
923 if (FD_ISSET(server_socket, &s->rfds))
924 execute_server_command();
925
926 /* Check the list of connected clients. */
927 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
928 if (FD_ISSET(client->fd, &s->rfds))
929 execute_afs_command(client->fd, ct->cookie);
930 else { /* prevent bogus connection flooding */
931 struct timeval diff;
932 tv_diff(now, &client->connect_time, &diff);
933 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
934 continue;
935 PARA_WARNING_LOG("connection timeout\n");
936 }
937 close(client->fd);
938 list_del(&client->node);
939 free(client);
940 }
941 /* Accept connections on the local socket. */
942 if (!FD_ISSET(ct->fd, &s->rfds))
943 goto out;
944 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
945 if (t->ret < 0) {
946 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
947 goto out;
948 }
949 fd = t->ret;
950 t->ret = mark_fd_nonblocking(fd);
951 if (t->ret < 0) {
952 PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
953 close(fd);
954 goto out;
955 }
956 client = para_malloc(sizeof(*client));
957 client->fd = fd;
958 client->connect_time = *now;
959 para_list_add(&client->node, &afs_client_list);
960 out:
961 t->ret = 1;
962 }
963
964 static void register_command_task(uint32_t cookie)
965 {
966 struct command_task *ct = &command_task_struct;
967 ct->fd = setup_command_socket_or_die();
968 ct->cookie = cookie;
969
970 ct->task.pre_select = command_pre_select;
971 ct->task.post_select = command_post_select;
972 ct->task.private_data = ct;
973 sprintf(ct->task.status, "command task");
974 register_task(&ct->task);
975 }
976
977 static void register_tasks(uint32_t cookie)
978 {
979 register_signal_task();
980 register_command_task(cookie);
981 }
982
983 /**
984 * Initialize the audio file selector process.
985 *
986 * \param cookie The value used for "authentication".
987 * \param socket_fd File descriptor used for communication with the server.
988 */
989 __noreturn void afs_init(uint32_t cookie, int socket_fd)
990 {
991 struct sched s;
992 int i, ret;
993
994 INIT_LIST_HEAD(&afs_client_list);
995 for (i = 0; i < NUM_AFS_TABLES; i++)
996 afs_tables[i].init(&afs_tables[i]);
997 ret = open_afs_tables();
998
999 if (ret < 0) {
1000 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1001 exit(EXIT_FAILURE);
1002 }
1003 server_socket = socket_fd;
1004 ret = mark_fd_nonblocking(server_socket);
1005 if (ret < 0)
1006 exit(EXIT_FAILURE);
1007 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1008 server_socket, (unsigned) cookie);
1009 init_admissible_files(conf.afs_initial_mode_arg);
1010 register_tasks(cookie);
1011 s.default_timeout.tv_sec = 0;
1012 s.default_timeout.tv_usec = 999 * 1000;
1013 ret = schedule(&s);
1014 if (ret < 0)
1015 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1016 close_afs_tables();
1017 exit(EXIT_FAILURE);
1018 }
1019
1020 static int create_tables_callback(const struct osl_object *query,
1021 __a_unused struct osl_object *result)
1022 {
1023 uint32_t table_mask = *(uint32_t *)query->data;
1024 int i, ret;
1025
1026 close_afs_tables();
1027 for (i = 0; i < NUM_AFS_TABLES; i++) {
1028 struct afs_table *t = &afs_tables[i];
1029
1030 if (!(table_mask & (1 << i)))
1031 continue;
1032 if (!t->create)
1033 continue;
1034 ret = t->create(database_dir);
1035 if (ret < 0)
1036 return ret;
1037 }
1038 ret = open_afs_tables();
1039 return ret < 0? ret: 0;
1040 }
1041
1042 int com_init(int fd, int argc, char * const * const argv)
1043 {
1044 int i, j, ret;
1045 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1046 struct osl_object query = {.data = &table_mask,
1047 .size = sizeof(table_mask)};
1048
1049 ret = make_database_dir();
1050 if (ret < 0)
1051 return ret;
1052 if (argc != 1) {
1053 table_mask = 0;
1054 for (i = 1; i < argc; i++) {
1055 for (j = 0; j < NUM_AFS_TABLES; j++) {
1056 struct afs_table *t = &afs_tables[j];
1057
1058 if (strcmp(argv[i], t->name))
1059 continue;
1060 table_mask |= (1 << j);
1061 break;
1062 }
1063 if (j == NUM_AFS_TABLES)
1064 return -E_BAD_TABLE_NAME;
1065 }
1066 }
1067 ret = send_callback_request(create_tables_callback, &query, NULL, NULL);
1068 if (ret < 0)
1069 return ret;
1070 return send_va_buffer(fd, "successfully created afs table(s)\n");
1071 }
1072
1073 /**
1074 * Flags for the check command.
1075 *
1076 * \sa com_check().
1077 */
1078 enum com_check_flags {
1079 /** Check the audio file table. */
1080 CHECK_AFT = 1,
1081 /** Check the mood table. */
1082 CHECK_MOODS = 2,
1083 /** Check the playlist table. */
1084 CHECK_PLAYLISTS = 4
1085 };
1086
1087 int com_check(int fd, int argc, char * const * const argv)
1088 {
1089 unsigned flags = 0;
1090 int i, ret;
1091
1092 for (i = 1; i < argc; i++) {
1093 const char *arg = argv[i];
1094 if (arg[0] != '-')
1095 break;
1096 if (!strcmp(arg, "--")) {
1097 i++;
1098 break;
1099 }
1100 if (!strcmp(arg, "-a")) {
1101 flags |= CHECK_AFT;
1102 continue;
1103 }
1104 if (!strcmp(arg, "-p")) {
1105 flags |= CHECK_PLAYLISTS;
1106 continue;
1107 }
1108 if (!strcmp(arg, "-m")) {
1109 flags |= CHECK_MOODS;
1110 continue;
1111 }
1112 return -E_AFS_SYNTAX;
1113 }
1114 if (i < argc)
1115 return -E_AFS_SYNTAX;
1116 if (!flags)
1117 flags = ~0U;
1118 if (flags & CHECK_AFT) {
1119 ret = send_callback_request(aft_check_callback, NULL, send_result, &fd);
1120 if (ret < 0)
1121 return ret;
1122 }
1123 if (flags & CHECK_PLAYLISTS) {
1124 ret = send_callback_request(playlist_check_callback, NULL, send_result, &fd);
1125 if (ret < 0)
1126 return ret;
1127 }
1128 if (flags & CHECK_MOODS) {
1129 ret = send_callback_request(mood_check_callback, NULL, send_result, &fd);
1130 if (ret < 0)
1131 return ret;
1132 }
1133 return 1;
1134 }
1135
1136 void afs_event(enum afs_events event, struct para_buffer *pb,
1137 void *data)
1138 {
1139 int i, ret;
1140
1141 for (i = 0; i < NUM_AFS_TABLES; i++) {
1142 struct afs_table *t = &afs_tables[i];
1143 if (!t->event_handler)
1144 continue;
1145 ret = t->event_handler(event, pb, data);
1146 if (ret < 0)
1147 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1148 }
1149 }
1150
1151 int images_event_handler(__a_unused enum afs_events event,
1152 __a_unused struct para_buffer *pb, __a_unused void *data)
1153 {
1154 return 1;
1155 }
1156
1157 int lyrics_event_handler(__a_unused enum afs_events event,
1158 __a_unused struct para_buffer *pb, __a_unused void *data)
1159 {
1160 return 1;
1161 }