gui: Use variable-sized input buffer for the audiod pipe.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2009 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 <openssl/rc4.h>
12 #include <osl.h>
13
14 #include "server.cmdline.h"
15 #include "para.h"
16 #include "error.h"
17 #include "crypt.h"
18 #include "string.h"
19 #include "afh.h"
20 #include "afs.h"
21 #include "server.h"
22 #include <dirent.h> /* readdir() */
23 #include <sys/mman.h>
24 #include <sys/time.h>
25 #include "net.h"
26 #include "ipc.h"
27 #include "list.h"
28 #include "sched.h"
29 #include "signal.h"
30 #include "fd.h"
31
32 /** The osl tables used by afs. \sa blob.c. */
33 enum afs_table_num {
34 /** Contains audio file information. See aft.c. */
35 TBLNUM_AUDIO_FILES,
36 /** The table for the paraslash attributes. See attribute.c. */
37 TBLNUM_ATTRIBUTES,
38 /**
39 * Paraslash's scoring system is based on Gaussian normal
40 * distributions, and the relevant data is stored in the rbtrees of an
41 * osl table containing only volatile columns. See score.c for
42 * details.
43 */
44 TBLNUM_SCORES,
45 /**
46 * A standard blob table containing the mood definitions. For details
47 * see mood.c.
48 */
49 TBLNUM_MOODS,
50 /** A blob table containing lyrics on a per-song basis. */
51 TBLNUM_LYRICS,
52 /** Another blob table for images (for example album cover art). */
53 TBLNUM_IMAGES,
54 /** Yet another blob table for storing standard playlists. */
55 TBLNUM_PLAYLIST,
56 /** How many tables are in use? */
57 NUM_AFS_TABLES
58 };
59
60 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
61 [TBLNUM_AUDIO_FILES] = {.init = aft_init},
62 [TBLNUM_ATTRIBUTES] = {.init = attribute_init},
63 [TBLNUM_SCORES] = {.init = score_init},
64 [TBLNUM_MOODS] = {.init = moods_init},
65 [TBLNUM_LYRICS] = {.init = lyrics_init},
66 [TBLNUM_IMAGES] = {.init = images_init},
67 [TBLNUM_PLAYLIST] = {.init = playlists_init},
68 };
69
70 struct command_task {
71 /** The file descriptor for the local socket. */
72 int fd;
73 /**
74 * Value sent by the command handlers to identify themselves as
75 * children of the running para_server.
76 */
77 uint32_t cookie;
78 /** The associated task structure. */
79 struct task task;
80 };
81
82 extern int mmd_mutex;
83 extern struct misc_meta_data *mmd;
84
85 static int server_socket;
86 static struct command_task command_task_struct;
87 static struct signal_task signal_task_struct;
88
89 static enum play_mode current_play_mode;
90 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
91
92 /**
93 * A random number used to "authenticate" the connection.
94 *
95 * para_server picks this number by random before forking the afs process. The
96 * command handlers write this number together with the id of the shared memory
97 * area containing the query. This way, a malicious local user has to know this
98 * number to be able to cause the afs process to crash by sending fake queries.
99 */
100 extern uint32_t afs_socket_cookie;
101
102 /**
103 * Struct to let command handlers execute a callback in afs context.
104 *
105 * Commands that need to change the state of afs can't change the relevant data
106 * structures directly because commands are executed in a child process, i.e.
107 * they get their own virtual address space.
108 *
109 * This structure is used by \p send_callback_request() (executed from handler
110 * context) in order to let the afs process call the specified function. An
111 * instance of that structure is written to a shared memory area together with
112 * the arguments to the callback function. The identifier of the shared memory
113 * area is written to the command socket.
114 *
115 * The afs process accepts connections on the command socket and reads the
116 * shared memory id, attaches the corresponing area, calls the given handler to
117 * perform the desired action and to optionally compute a result.
118 *
119 * The result and a \p callback_result structure is then written to another
120 * shared memory area. The identifier for that area is written to the handler's
121 * command socket, so that the handler process can read the id, attach the
122 * shared memory area and use the result.
123 *
124 * \sa struct callback_result.
125 */
126 struct callback_query {
127 /** The function to be called. */
128 callback_function *handler;
129 /** The number of bytes of the query */
130 size_t query_size;
131 };
132
133 /**
134 * Structure embedded in the result of a callback.
135 *
136 * If the callback produced a result, an instance of that structure is embeeded
137 * into the shared memory area holding the result, mainly to let the command
138 * handler know the size of the result.
139 *
140 * \sa struct callback_query.
141 */
142 struct callback_result {
143 /** The number of bytes of the result. */
144 size_t result_size;
145 };
146
147 static int dispatch_result(int result_shmid, callback_result_handler *handler,
148 void *private_result_data)
149 {
150 struct osl_object result;
151 void *result_shm;
152 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
153 struct callback_result *cr = result_shm;
154
155 if (ret < 0) {
156 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
157 return ret;
158 }
159 result.size = cr->result_size;
160 result.data = result_shm + sizeof(*cr);
161 if (result.size) {
162 assert(handler);
163 ret = handler(&result, private_result_data);
164 if (ret < 0)
165 PARA_NOTICE_LOG("result handler error: %s\n",
166 para_strerror(-ret));
167 }
168 ret2 = shm_detach(result_shm);
169 if (ret2 < 0) {
170 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
171 if (ret >= 0)
172 ret = ret2;
173 }
174 return ret;
175 }
176
177 /**
178 * Ask the afs process to call a given function.
179 *
180 * \param f The function to be called.
181 * \param query Pointer to arbitrary data for the callback.
182 * \param result_handler Called for each shm area sent by the callback.
183 * \param private_result_data Passed verbatim to \a result_handler.
184 *
185 * This function creates a socket for communication with the afs process and a
186 * shared memory area (sma) to which the buffer pointed to by \a query is
187 * copied. It then notifies the afs process that the callback function \a f
188 * should be executed by sending the shared memory identifier (shmid) to the
189 * socket.
190
191 * If the callback produces a result, it sends any number of shared memory
192 * identifiers back via the socket. For each such identifier received, \a
193 * result_handler is called. The contents of the sma identified by the received
194 * shmid are passed to that function as an osl object. The private_result_data
195 * pointer is passed as the second argument to \a result_handler.
196 *
197 * \return Standard.
198 *
199 * \sa send_option_arg_callback_request(), send_standard_callback_request().
200 */
201 int send_callback_request(callback_function *f, struct osl_object *query,
202 callback_result_handler *result_handler,
203 void *private_result_data)
204 {
205 struct callback_query *cq;
206 int ret, fd = -1, query_shmid, result_shmid;
207 void *query_shm;
208 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
209 size_t query_shm_size = sizeof(*cq);
210 int dispatch_error = 0;
211
212 if (query)
213 query_shm_size += query->size;
214 ret = shm_new(query_shm_size);
215 if (ret < 0)
216 return ret;
217 query_shmid = ret;
218 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
219 if (ret < 0)
220 goto out;
221 cq = query_shm;
222 cq->handler = f;
223 cq->query_size = query_shm_size - sizeof(*cq);
224
225 if (query)
226 memcpy(query_shm + sizeof(*cq), query->data, query->size);
227 ret = shm_detach(query_shm);
228 if (ret < 0)
229 goto out;
230
231 *(uint32_t *) buf = afs_socket_cookie;
232 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
233
234 ret = create_remote_socket(conf.afs_socket_arg);
235 if (ret < 0)
236 goto out;
237 fd = ret;
238 ret = send_bin_buffer(fd, buf, sizeof(buf));
239 if (ret < 0)
240 goto out;
241 /*
242 * Read all shmids from afs.
243 *
244 * Even if the dispatcher returns an error we _must_ continue to read
245 * shmids from fd so that we can destroy all shared memory areas that
246 * have been created for us by the afs process.
247 */
248 for (;;) {
249 ret = recv_bin_buffer(fd, buf, sizeof(int));
250 if (ret <= 0)
251 goto out;
252 assert(ret == sizeof(int));
253 ret = *(int *) buf;
254 assert(ret > 0);
255 result_shmid = ret;
256 if (!dispatch_error) {
257 ret = dispatch_result(result_shmid, result_handler,
258 private_result_data);
259 if (ret < 0)
260 dispatch_error = 1;
261 }
262 ret = shm_destroy(result_shmid);
263 if (ret < 0)
264 PARA_CRIT_LOG("destroy result failed: %s\n",
265 para_strerror(-ret));
266 }
267 out:
268 if (shm_destroy(query_shmid) < 0)
269 PARA_CRIT_LOG("shm destroy error\n");
270 if (fd >= 0)
271 close(fd);
272 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
273 return ret;
274 }
275
276 /**
277 * Send a callback request passing an options structure and an argument vector.
278 *
279 * \param options pointer to an arbitrary data structure.
280 * \param argc Argument count.
281 * \param argv Standard argument vector.
282 * \param f The callback function.
283 * \param result_handler See \ref send_callback_request.
284 * \param private_result_data See \ref send_callback_request.
285 *
286 * Some commands have a couple of options that are parsed in child context for
287 * syntactic correctness and are stored in a special options structure for that
288 * command. This function allows to pass such a structure together with a list
289 * of further arguments (often a list of audio files) to the parent process.
290 *
291 * \sa send_standard_callback_request(), send_callback_request().
292 */
293 int send_option_arg_callback_request(struct osl_object *options,
294 int argc, char * const * const argv, callback_function *f,
295 callback_result_handler *result_handler,
296 void *private_result_data)
297 {
298 char *p;
299 int i, ret;
300 struct osl_object query = {.size = options? options->size : 0};
301
302 for (i = 0; i < argc; i++)
303 query.size += strlen(argv[i]) + 1;
304 query.data = para_malloc(query.size);
305 p = query.data;
306 if (options) {
307 memcpy(query.data, options->data, options->size);
308 p += options->size;
309 }
310 for (i = 0; i < argc; i++) {
311 strcpy(p, argv[i]); /* OK */
312 p += strlen(argv[i]) + 1;
313 }
314 ret = send_callback_request(f, &query, result_handler,
315 private_result_data);
316 free(query.data);
317 return ret;
318 }
319
320 /**
321 * Send a callback request with an argument vector only.
322 *
323 * \param argc The same meaning as in send_option_arg_callback_request().
324 * \param argv The same meaning as in send_option_arg_callback_request().
325 * \param f The same meaning as in send_option_arg_callback_request().
326 * \param result_handler See \ref send_callback_request.
327 * \param private_result_data See \ref send_callback_request.
328 *
329 * This is similar to send_option_arg_callback_request(), but no options buffer
330 * is passed to the parent process.
331 *
332 * \return The return value of the underlying call to
333 * send_option_arg_callback_request().
334 */
335 int send_standard_callback_request(int argc, char * const * const argv,
336 callback_function *f, callback_result_handler *result_handler,
337 void *private_result_data)
338 {
339 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
340 private_result_data);
341 }
342
343 static int action_if_pattern_matches(struct osl_row *row, void *data)
344 {
345 struct pattern_match_data *pmd = data;
346 struct osl_object name_obj;
347 const char *p, *name;
348 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
349 const char *pattern_txt = (const char *)pmd->patterns.data;
350
351 if (ret < 0)
352 return ret;
353 name = (char *)name_obj.data;
354 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
355 return 1;
356 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
357 return pmd->action(pmd->table, row, name, pmd->data);
358 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
359 p += strlen(p) + 1) {
360 ret = fnmatch(p, name, pmd->fnmatch_flags);
361 if (ret == FNM_NOMATCH)
362 continue;
363 if (ret)
364 return -E_FNMATCH;
365 return pmd->action(pmd->table, row, name, pmd->data);
366 }
367 return 1;
368 }
369
370 /**
371 * Execute the given function for each matching row.
372 *
373 * \param pmd Describes what to match and how.
374 *
375 * \return Standard.
376 */
377 int for_each_matching_row(struct pattern_match_data *pmd)
378 {
379 if (pmd->pm_flags & PM_REVERSE_LOOP)
380 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
381 action_if_pattern_matches));
382 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
383 action_if_pattern_matches));
384 }
385
386 /**
387 * Compare two osl objects of string type.
388 *
389 * \param obj1 Pointer to the first object.
390 * \param obj2 Pointer to the second object.
391 *
392 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
393 * are taken into account.
394 *
395 * \return It returns an integer less than, equal to, or greater than zero if
396 * \a obj1 is found, respectively, to be less than, to match, or be greater than
397 * obj2.
398 *
399 * \sa strcmp(3), strncmp(3), osl_compare_func.
400 */
401 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
402 {
403 const char *str1 = (const char *)obj1->data;
404 const char *str2 = (const char *)obj2->data;
405 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
406 }
407
408 static int pass_afd(int fd, char *buf, size_t size)
409 {
410 struct msghdr msg = {.msg_iov = NULL};
411 struct cmsghdr *cmsg;
412 char control[255];
413 int ret;
414 struct iovec iov;
415
416 iov.iov_base = buf;
417 iov.iov_len = size;
418
419 msg.msg_iov = &iov;
420 msg.msg_iovlen = 1;
421
422 msg.msg_control = control;
423 msg.msg_controllen = sizeof(control);
424
425 cmsg = CMSG_FIRSTHDR(&msg);
426 cmsg->cmsg_level = SOL_SOCKET;
427 cmsg->cmsg_type = SCM_RIGHTS;
428 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
429 *(int *)CMSG_DATA(cmsg) = fd;
430
431 /* Sum of the length of all control messages in the buffer */
432 msg.msg_controllen = cmsg->cmsg_len;
433 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
434 ret = sendmsg(server_socket, &msg, 0);
435 if (ret < 0) {
436 ret = -ERRNO_TO_PARA_ERROR(errno);
437 return ret;
438 }
439 return 1;
440 }
441
442 /**
443 * Open the audio file with highest score.
444 *
445 * This stores all information for streaming the "best" audio file in a shared
446 * memory area. The id of that area and an open file descriptor for the next
447 * audio file are passed to the server process.
448 *
449 * \return Standard.
450 *
451 * \sa open_and_update_audio_file().
452 */
453 static int open_next_audio_file(void)
454 {
455 struct osl_row *aft_row;
456 struct audio_file_data afd;
457 int ret, shmid;
458 char buf[8];
459 long score;
460 again:
461 PARA_NOTICE_LOG("getting next audio file\n");
462 ret = score_get_best(&aft_row, &score);
463 if (ret < 0) {
464 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
465 goto no_admissible_files;
466 }
467 ret = open_and_update_audio_file(aft_row, score, &afd);
468 if (ret < 0) {
469 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
470 ret = score_delete(aft_row);
471 if (ret < 0) {
472 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
473 goto no_admissible_files;
474 }
475 goto again;
476 }
477 shmid = ret;
478 if (!write_ok(server_socket)) {
479 ret = -E_AFS_SOCKET;
480 goto destroy;
481 }
482 *(uint32_t *)buf = NEXT_AUDIO_FILE;
483 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
484 ret = pass_afd(afd.fd, buf, 8);
485 close(afd.fd);
486 if (ret >= 0)
487 return ret;
488 destroy:
489 shm_destroy(shmid);
490 return ret;
491 no_admissible_files:
492 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
493 *(uint32_t *)(buf + 4) = (uint32_t)0;
494 return send_bin_buffer(server_socket, buf, 8);
495 }
496
497 /* Never fails if arg == NULL */
498 static int activate_mood_or_playlist(char *arg, int *num_admissible)
499 {
500 enum play_mode mode;
501 int ret;
502
503 if (!arg) {
504 ret = change_current_mood(NULL); /* always successful */
505 mode = PLAY_MODE_MOOD;
506 } else {
507 if (!strncmp(arg, "p/", 2)) {
508 ret = playlist_open(arg + 2);
509 mode = PLAY_MODE_PLAYLIST;
510 } else if (!strncmp(arg, "m/", 2)) {
511 ret = change_current_mood(arg + 2);
512 mode = PLAY_MODE_MOOD;
513 } else
514 return -E_AFS_SYNTAX;
515 if (ret < 0)
516 return ret;
517 }
518 if (num_admissible)
519 *num_admissible = ret;
520 current_play_mode = mode;
521 if (arg != current_mop) {
522 free(current_mop);
523 if (arg) {
524 current_mop = para_strdup(arg);
525 mutex_lock(mmd_mutex);
526 strncpy(mmd->afs_mode_string, arg,
527 sizeof(mmd->afs_mode_string));
528 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
529 mutex_unlock(mmd_mutex);
530 } else {
531 mutex_lock(mmd_mutex);
532 strcpy(mmd->afs_mode_string, "dummy");
533 mutex_unlock(mmd_mutex);
534 current_mop = NULL;
535 }
536 }
537 return 1;
538 }
539
540 static void com_select_callback(int fd, const struct osl_object *query)
541 {
542 struct para_buffer pb = {
543 .max_size = SHMMAX,
544 .private_data = &fd,
545 .max_size_handler = pass_buffer_as_shm
546 };
547 char *arg = query->data;
548 int num_admissible, ret, ret2;
549
550 ret = clear_score_table();
551 if (ret < 0) {
552 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
553 goto out;
554 }
555 if (current_play_mode == PLAY_MODE_MOOD)
556 close_current_mood();
557 else
558 playlist_close();
559 ret = activate_mood_or_playlist(arg, &num_admissible);
560 if (ret < 0) {
561 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
562 para_strerror(-ret), current_mop?
563 current_mop : "dummy");
564 ret = activate_mood_or_playlist(current_mop, &num_admissible);
565 if (ret < 0) {
566 if (ret2 >= 0)
567 ret2 = para_printf(&pb, "failed, switching to dummy\n");
568 activate_mood_or_playlist(NULL, &num_admissible);
569 }
570 } else
571 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
572 current_mop : "dummy mood", num_admissible);
573 out:
574 if (ret2 >= 0 && pb.offset)
575 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
576 free(pb.buf);
577 }
578
579 /**
580 * Result handler for sending data to the para_client process.
581 *
582 * \param result The data to be sent.
583 * \param private Pointer to rc4 context.
584 *
585 * \return The return value of the underlying call to rc4_send_bin_buffer().
586 *
587 * \sa \ref callback_result_handler, \ref rc4_send_bin_buffer().
588 */
589 int rc4_send_result(struct osl_object *result, void *private)
590 {
591 struct rc4_context *rc4c = private;
592
593 if (!result->size)
594 return 1;
595 return rc4_send_bin_buffer(rc4c, result->data, result->size);
596 }
597
598 int com_select(struct rc4_context *rc4c, int argc, char * const * const argv)
599 {
600 struct osl_object query;
601
602 if (argc != 2)
603 return -E_AFS_SYNTAX;
604 query.data = argv[1];
605 query.size = strlen(argv[1]) + 1;
606 return send_callback_request(com_select_callback, &query,
607 &rc4_send_result, rc4c);
608 }
609
610 static void init_admissible_files(char *arg)
611 {
612 if (activate_mood_or_playlist(arg, NULL) < 0)
613 activate_mood_or_playlist(NULL, NULL); /* always successful */
614 }
615
616 static int setup_command_socket_or_die(void)
617 {
618 int ret, socket_fd;
619 char *socket_name = conf.afs_socket_arg;
620 struct sockaddr_un unix_addr;
621
622 unlink(socket_name);
623 ret = create_local_socket(socket_name, &unix_addr,
624 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
625 if (ret < 0) {
626 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
627 exit(EXIT_FAILURE);
628 }
629 socket_fd = ret;
630 if (listen(socket_fd , 5) < 0) {
631 PARA_EMERG_LOG("can not listen on socket\n");
632 exit(EXIT_FAILURE);
633 }
634 ret = mark_fd_nonblocking(socket_fd);
635 if (ret < 0) {
636 close(socket_fd);
637 return ret;
638 }
639 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
640 socket_fd);
641 return socket_fd;
642 }
643
644 static void close_afs_tables(void)
645 {
646 int i;
647 PARA_NOTICE_LOG("closing afs_tables\n");
648 for (i = 0; i < NUM_AFS_TABLES; i++)
649 afs_tables[i].close();
650 }
651
652 static char *database_dir;
653
654 static void get_database_dir(void)
655 {
656 if (!database_dir) {
657 if (conf.afs_database_dir_given)
658 database_dir = para_strdup(conf.afs_database_dir_arg);
659 else {
660 char *home = para_homedir();
661 database_dir = make_message(
662 "%s/.paraslash/afs_database-0.4", home);
663 free(home);
664 }
665 }
666 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
667 }
668
669 static int make_database_dir(void)
670 {
671 int ret;
672
673 get_database_dir();
674 ret = para_mkdir(database_dir, 0777);
675 if (ret >= 0 || is_errno(-ret, EEXIST))
676 return 1;
677 return ret;
678 }
679
680 static int open_afs_tables(void)
681 {
682 int i, ret;
683
684 get_database_dir();
685 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
686 database_dir);
687 for (i = 0; i < NUM_AFS_TABLES; i++) {
688 ret = afs_tables[i].open(database_dir);
689 if (ret >= 0)
690 continue;
691 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
692 para_strerror(-ret));
693 break;
694 }
695 if (ret >= 0)
696 return ret;
697 while (i)
698 afs_tables[--i].close();
699 return ret;
700 }
701
702 static void signal_pre_select(struct sched *s, struct task *t)
703 {
704 struct signal_task *st = container_of(t, struct signal_task, task);
705 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
706 }
707
708 static void afs_signal_post_select(struct sched *s, struct task *t)
709 {
710 struct signal_task *st = container_of(t, struct signal_task, task);
711 if (getppid() == 1) {
712 PARA_EMERG_LOG("para_server died\n");
713 goto shutdown;
714 }
715 if (!FD_ISSET(st->fd, &s->rfds))
716 return;
717 st->signum = para_next_signal();
718 if (st->signum == SIGHUP) {
719 close_afs_tables();
720 parse_config_or_die(1);
721 t->error = open_afs_tables();
722 if (t->error < 0)
723 return;
724 init_admissible_files(current_mop);
725 return;
726 }
727 PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
728 shutdown:
729 sched_shutdown();
730 t->error = -E_AFS_SIGNAL;
731 }
732
733 static void register_signal_task(void)
734 {
735 struct signal_task *st = &signal_task_struct;
736
737 para_sigaction(SIGPIPE, SIG_IGN);
738 st->fd = para_signal_init();
739 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
740 para_install_sighandler(SIGINT);
741 para_install_sighandler(SIGTERM);
742 para_install_sighandler(SIGHUP);
743
744 st->task.pre_select = signal_pre_select;
745 st->task.post_select = afs_signal_post_select;
746 sprintf(st->task.status, "signal task");
747 register_task(&st->task);
748 }
749
750 static struct list_head afs_client_list;
751
752 /** Describes on connected afs client. */
753 struct afs_client {
754 /** Position in the afs client list. */
755 struct list_head node;
756 /** The socket file descriptor for this client. */
757 int fd;
758 /** The time the client connected. */
759 struct timeval connect_time;
760 };
761
762 static void command_pre_select(struct sched *s, struct task *t)
763 {
764 struct command_task *ct = container_of(t, struct command_task, task);
765 struct afs_client *client;
766
767 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
768 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
769 list_for_each_entry(client, &afs_client_list, node)
770 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
771 }
772
773 /**
774 * Send data as shared memory to a file descriptor.
775 *
776 * \param buf The buffer holding the data to be sent.
777 * \param size The size of \a buf.
778 * \param fd_ptr A pointer to the file descriptor.
779 *
780 * This function is used as the \a max_size handler in a \ref para_buffer
781 * structure. If used this way, it is called by \ref para_printf() whenever
782 * the buffer passed to para_printf() is about to exceed its maximal size.
783 *
784 * This function creates a shared memory area large enough to hold
785 * the content given by \a buf and \a size and sends the identifier
786 * of this area to the file descriptor given by \a fd_ptr.
787 *
788 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
789 * and positive on success.
790 */
791 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
792 {
793 int ret, shmid, fd = *(int *)fd_ptr;
794 void *shm;
795 struct callback_result *cr;
796
797 if (!buf || !size)
798 return 0;
799 ret = shm_new(size + sizeof(struct callback_result));
800 if (ret < 0)
801 return ret;
802 shmid = ret;
803 ret = shm_attach(shmid, ATTACH_RW, &shm);
804 if (ret < 0)
805 goto err;
806 cr = shm;
807 cr->result_size = size;
808 memcpy(shm + sizeof(*cr), buf, size);
809 ret = shm_detach(shm);
810 if (ret < 0)
811 goto err;
812 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
813 if (ret >= 0)
814 return ret;
815 err:
816 if (shm_destroy(shmid) < 0)
817 PARA_ERROR_LOG("destroy result failed\n");
818 return ret;
819 }
820
821 /*
822 * On errors, negative value is written to fd.
823 * On success: If query produced a result, the result_shmid is written to fd.
824 * Otherwise, zero is written.
825 */
826 static int call_callback(int fd, int query_shmid)
827 {
828 void *query_shm;
829 struct callback_query *cq;
830 struct osl_object query;
831 int ret;
832
833 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
834 if (ret < 0)
835 return ret;
836 cq = query_shm;
837 query.data = (char *)query_shm + sizeof(*cq);
838 query.size = cq->query_size;
839 cq->handler(fd, &query);
840 return shm_detach(query_shm);
841 }
842
843 static int execute_server_command(void)
844 {
845 char buf[8];
846 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
847
848 if (ret <= 0) {
849 if (!ret)
850 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
851 goto err;
852 }
853 buf[ret] = '\0';
854 PARA_DEBUG_LOG("received: %s\n", buf);
855 ret = -E_BAD_CMD;
856 if (strcmp(buf, "new"))
857 goto err;
858 ret = open_next_audio_file();
859 err:
860 return ret;
861 }
862
863 static void execute_afs_command(int fd, uint32_t expected_cookie)
864 {
865 uint32_t cookie;
866 int query_shmid;
867 char buf[sizeof(cookie) + sizeof(query_shmid)];
868 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
869
870 if (ret < 0)
871 goto err;
872 if (ret != sizeof(buf)) {
873 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
874 ret, (long unsigned) sizeof(buf));
875 return;
876 }
877 cookie = *(uint32_t *)buf;
878 if (cookie != expected_cookie) {
879 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
880 (unsigned)cookie, (unsigned)expected_cookie);
881 return;
882 }
883 query_shmid = *(int *)(buf + sizeof(cookie));
884 if (query_shmid < 0) {
885 PARA_WARNING_LOG("received invalid query shmid %d)\n",
886 query_shmid);
887 return;
888 }
889 ret = call_callback(fd, query_shmid);
890 if (ret >= 0)
891 return;
892 err:
893 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
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 = container_of(t, struct command_task, task);
902 struct sockaddr_un unix_addr;
903 struct afs_client *client, *tmp;
904 int fd, ret;
905
906 if (FD_ISSET(server_socket, &s->rfds)) {
907 ret = execute_server_command();
908 if (ret < 0) {
909 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
910 sched_shutdown();
911 return;
912 }
913 }
914
915 /* Check the list of connected clients. */
916 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
917 if (FD_ISSET(client->fd, &s->rfds))
918 execute_afs_command(client->fd, ct->cookie);
919 else { /* prevent bogus connection flooding */
920 struct timeval diff;
921 tv_diff(now, &client->connect_time, &diff);
922 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
923 continue;
924 PARA_WARNING_LOG("connection timeout\n");
925 }
926 close(client->fd);
927 list_del(&client->node);
928 free(client);
929 }
930 /* Accept connections on the local socket. */
931 if (!FD_ISSET(ct->fd, &s->rfds))
932 return;
933 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
934 if (ret < 0) {
935 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
936 return;
937 }
938 fd = ret;
939 ret = mark_fd_nonblocking(fd);
940 if (ret < 0) {
941 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
942 close(fd);
943 return;
944 }
945 client = para_malloc(sizeof(*client));
946 client->fd = fd;
947 client->connect_time = *now;
948 para_list_add(&client->node, &afs_client_list);
949 }
950
951 static void register_command_task(uint32_t cookie)
952 {
953 struct command_task *ct = &command_task_struct;
954 ct->fd = setup_command_socket_or_die();
955 ct->cookie = cookie;
956
957 ct->task.pre_select = command_pre_select;
958 ct->task.post_select = command_post_select;
959 sprintf(ct->task.status, "command task");
960 register_task(&ct->task);
961 }
962
963 /**
964 * Initialize the audio file selector process.
965 *
966 * \param cookie The value used for "authentication".
967 * \param socket_fd File descriptor used for communication with the server.
968 */
969 __noreturn void afs_init(uint32_t cookie, int socket_fd)
970 {
971 static struct sched s;
972 int i, ret;
973
974 register_signal_task();
975 INIT_LIST_HEAD(&afs_client_list);
976 for (i = 0; i < NUM_AFS_TABLES; i++)
977 afs_tables[i].init(&afs_tables[i]);
978 ret = open_afs_tables();
979 if (ret < 0)
980 goto out;
981 server_socket = socket_fd;
982 ret = mark_fd_nonblocking(server_socket);
983 if (ret < 0)
984 goto out_close;
985 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
986 server_socket, (unsigned) cookie);
987 init_admissible_files(conf.afs_initial_mode_arg);
988 register_command_task(cookie);
989 s.default_timeout.tv_sec = 0;
990 s.default_timeout.tv_usec = 999 * 1000;
991 ret = schedule(&s);
992 out_close:
993 close_afs_tables();
994 out:
995 if (ret < 0)
996 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
997 exit(EXIT_FAILURE);
998 }
999
1000 static void create_tables_callback(int fd, const struct osl_object *query)
1001 {
1002 uint32_t table_mask = *(uint32_t *)query->data;
1003 int i, ret;
1004 char *buf;
1005
1006 close_afs_tables();
1007 for (i = 0; i < NUM_AFS_TABLES; i++) {
1008 struct afs_table *t = &afs_tables[i];
1009
1010 if (!(table_mask & (1 << i)))
1011 continue;
1012 if (!t->create)
1013 continue;
1014 ret = t->create(database_dir);
1015 if (ret < 0)
1016 goto out;
1017 }
1018 ret = open_afs_tables();
1019 out:
1020 if (ret >= 0)
1021 buf = make_message("successfully created afs table(s)\n");
1022 else
1023 buf = make_message("%s\n", para_strerror(-ret));
1024 pass_buffer_as_shm(buf, strlen(buf), &fd);
1025 free(buf);
1026 }
1027
1028 int com_init(struct rc4_context *rc4c, int argc, char * const * const argv)
1029 {
1030 int i, j, ret;
1031 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1032 struct osl_object query = {.data = &table_mask,
1033 .size = sizeof(table_mask)};
1034
1035 ret = make_database_dir();
1036 if (ret < 0)
1037 return ret;
1038 if (argc != 1) {
1039 table_mask = 0;
1040 for (i = 1; i < argc; i++) {
1041 for (j = 0; j < NUM_AFS_TABLES; j++) {
1042 struct afs_table *t = &afs_tables[j];
1043
1044 if (strcmp(argv[i], t->name))
1045 continue;
1046 table_mask |= (1 << j);
1047 break;
1048 }
1049 if (j == NUM_AFS_TABLES)
1050 return -E_BAD_TABLE_NAME;
1051 }
1052 }
1053 ret = send_callback_request(create_tables_callback, &query,
1054 rc4_send_result, rc4c);
1055 if (ret < 0)
1056 return rc4_send_va_buffer(rc4c, "%s\n", para_strerror(-ret));
1057 return ret;
1058 }
1059
1060 /**
1061 * Flags for the check command.
1062 *
1063 * \sa com_check().
1064 */
1065 enum com_check_flags {
1066 /** Check the audio file table. */
1067 CHECK_AFT = 1,
1068 /** Check the mood table. */
1069 CHECK_MOODS = 2,
1070 /** Check the playlist table. */
1071 CHECK_PLAYLISTS = 4
1072 };
1073
1074 int com_check(struct rc4_context *rc4c, int argc, char * const * const argv)
1075 {
1076 unsigned flags = 0;
1077 int i, ret;
1078
1079 for (i = 1; i < argc; i++) {
1080 const char *arg = argv[i];
1081 if (arg[0] != '-')
1082 break;
1083 if (!strcmp(arg, "--")) {
1084 i++;
1085 break;
1086 }
1087 if (!strcmp(arg, "-a")) {
1088 flags |= CHECK_AFT;
1089 continue;
1090 }
1091 if (!strcmp(arg, "-p")) {
1092 flags |= CHECK_PLAYLISTS;
1093 continue;
1094 }
1095 if (!strcmp(arg, "-m")) {
1096 flags |= CHECK_MOODS;
1097 continue;
1098 }
1099 return -E_AFS_SYNTAX;
1100 }
1101 if (i < argc)
1102 return -E_AFS_SYNTAX;
1103 if (!flags)
1104 flags = ~0U;
1105 if (flags & CHECK_AFT) {
1106 ret = send_callback_request(aft_check_callback, NULL,
1107 rc4_send_result, rc4c);
1108 if (ret < 0)
1109 return ret;
1110 }
1111 if (flags & CHECK_PLAYLISTS) {
1112 ret = send_callback_request(playlist_check_callback,
1113 NULL, rc4_send_result, rc4c);
1114 if (ret < 0)
1115 return ret;
1116 }
1117 if (flags & CHECK_MOODS) {
1118 ret = send_callback_request(mood_check_callback, NULL,
1119 rc4_send_result, rc4c);
1120 if (ret < 0)
1121 return ret;
1122 }
1123 return 1;
1124 }
1125
1126 /**
1127 * The afs event dispatcher.
1128 *
1129 * \param event Type of the event.
1130 * \param pb May be \p NULL.
1131 * \param data Type depends on \a event.
1132 *
1133 * This function calls the table handlers of all tables and passes \a pb and \a
1134 * data verbatim. It's up to the handlers to interpret the \a data pointer.
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("table %s, event %d: %s\n", t->name,
1148 event, 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 }