Merge branch 't/audioc_cleanups'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2012 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 <regex.h>
10 #include <signal.h>
11 #include <fnmatch.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 "net.h"
23 #include "ipc.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "signal.h"
27 #include "fd.h"
28 #include "mood.h"
29 #include "command.h"
30
31 /** The osl tables used by afs. \sa blob.c. */
32 enum afs_table_num {
33 /** Contains audio file information. See aft.c. */
34 TBLNUM_AUDIO_FILES,
35 /** The table for the paraslash attributes. See attribute.c. */
36 TBLNUM_ATTRIBUTES,
37 /**
38 * Paraslash's scoring system is based on Gaussian normal
39 * distributions, and the relevant data is stored in the rbtrees of an
40 * osl table containing only volatile columns. See score.c for
41 * details.
42 */
43 TBLNUM_SCORES,
44 /**
45 * A standard blob table containing the mood definitions. For details
46 * see mood.c.
47 */
48 TBLNUM_MOODS,
49 /** A blob table containing lyrics on a per-song basis. */
50 TBLNUM_LYRICS,
51 /** Another blob table for images (for example album cover art). */
52 TBLNUM_IMAGES,
53 /** Yet another blob table for storing standard playlists. */
54 TBLNUM_PLAYLIST,
55 /** How many tables are in use? */
56 NUM_AFS_TABLES
57 };
58
59 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
60 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
61 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
62 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
63 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
64 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
65 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
66 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
67 };
68
69 struct command_task {
70 /** The file descriptor for the local socket. */
71 int fd;
72 /**
73 * Value sent by the command handlers to identify themselves as
74 * children of the running para_server.
75 */
76 uint32_t cookie;
77 /** The associated task structure. */
78 struct task task;
79 };
80
81 extern int mmd_mutex;
82 extern struct misc_meta_data *mmd;
83
84 static int server_socket;
85 static struct command_task command_task_struct;
86 static struct signal_task signal_task_struct;
87
88 static enum play_mode current_play_mode;
89 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
90
91 /**
92 * A random number used to "authenticate" the connection.
93 *
94 * para_server picks this number by random before forking the afs process. The
95 * command handlers write this number together with the id of the shared memory
96 * area containing the query. This way, a malicious local user has to know this
97 * number to be able to cause the afs process to crash by sending fake queries.
98 */
99 extern uint32_t afs_socket_cookie;
100
101 /**
102 * Struct to let command handlers execute a callback in afs context.
103 *
104 * Commands that need to change the state of afs can't change the relevant data
105 * structures directly because commands are executed in a child process, i.e.
106 * they get their own virtual address space.
107 *
108 * This structure is used by \p send_callback_request() (executed from handler
109 * context) in order to let the afs process call the specified function. An
110 * instance of that structure is written to a shared memory area together with
111 * the arguments to the callback function. The identifier of the shared memory
112 * area is written to the command socket.
113 *
114 * The afs process accepts connections on the command socket and reads the
115 * shared memory id, attaches the corresponing area, calls the given handler to
116 * perform the desired action and to optionally compute a result.
117 *
118 * The result and a \p callback_result structure is then written to another
119 * shared memory area. The identifier for that area is written to the handler's
120 * command socket, so that the handler process can read the id, attach the
121 * shared memory area and use the result.
122 *
123 * \sa struct callback_result.
124 */
125 struct callback_query {
126 /** The function to be called. */
127 callback_function *handler;
128 /** The number of bytes of the query */
129 size_t query_size;
130 };
131
132 /**
133 * Structure embedded in the result of a callback.
134 *
135 * If the callback produced a result, an instance of that structure is embeeded
136 * into the shared memory area holding the result, mainly to let the command
137 * handler know the size of the result.
138 *
139 * \sa struct callback_query.
140 */
141 struct callback_result {
142 /** The number of bytes of the result. */
143 size_t result_size;
144 };
145
146 static int dispatch_result(int result_shmid, callback_result_handler *handler,
147 void *private_result_data)
148 {
149 struct osl_object result;
150 void *result_shm;
151 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
152 struct callback_result *cr = result_shm;
153
154 if (ret < 0) {
155 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
156 return ret;
157 }
158 result.size = cr->result_size;
159 result.data = result_shm + sizeof(*cr);
160 if (result.size) {
161 assert(handler);
162 ret = handler(&result, private_result_data);
163 if (ret < 0)
164 PARA_NOTICE_LOG("result handler error: %s\n",
165 para_strerror(-ret));
166 }
167 ret2 = shm_detach(result_shm);
168 if (ret2 < 0) {
169 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
170 if (ret >= 0)
171 ret = ret2;
172 }
173 return ret;
174 }
175
176 /**
177 * Ask the afs process to call a given function.
178 *
179 * \param f The function to be called.
180 * \param query Pointer to arbitrary data for the callback.
181 * \param result_handler Called for each shm area sent by the callback.
182 * \param private_result_data Passed verbatim to \a result_handler.
183 *
184 * This function creates a socket for communication with the afs process and a
185 * shared memory area (sma) to which the buffer pointed to by \a query is
186 * copied. It then notifies the afs process that the callback function \a f
187 * should be executed by sending the shared memory identifier (shmid) to the
188 * socket.
189
190 * If the callback produces a result, it sends any number of shared memory
191 * identifiers back via the socket. For each such identifier received, \a
192 * result_handler is called. The contents of the sma identified by the received
193 * shmid are passed to that function as an osl object. The private_result_data
194 * pointer is passed as the second argument to \a result_handler.
195 *
196 * \return Number of shared memory areas dispatched on success, negative on errors.
197 *
198 * \sa send_option_arg_callback_request(), send_standard_callback_request().
199 */
200 int send_callback_request(callback_function *f, struct osl_object *query,
201 callback_result_handler *result_handler,
202 void *private_result_data)
203 {
204 struct callback_query *cq;
205 int ret, fd = -1, query_shmid, result_shmid;
206 void *query_shm;
207 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
208 size_t query_shm_size = sizeof(*cq);
209 int dispatch_error = 0, num_dispatched = 0;
210
211 if (query)
212 query_shm_size += query->size;
213 ret = shm_new(query_shm_size);
214 if (ret < 0)
215 return ret;
216 query_shmid = ret;
217 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
218 if (ret < 0)
219 goto out;
220 cq = query_shm;
221 cq->handler = f;
222 cq->query_size = query_shm_size - sizeof(*cq);
223
224 if (query)
225 memcpy(query_shm + sizeof(*cq), query->data, query->size);
226 ret = shm_detach(query_shm);
227 if (ret < 0)
228 goto out;
229
230 *(uint32_t *) buf = afs_socket_cookie;
231 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
232
233 ret = connect_local_socket(conf.afs_socket_arg);
234 if (ret < 0)
235 goto out;
236 fd = ret;
237 ret = write_all(fd, buf, sizeof(buf));
238 if (ret < 0)
239 goto out;
240 /*
241 * Read all shmids from afs.
242 *
243 * Even if the dispatcher returns an error we _must_ continue to read
244 * shmids from fd so that we can destroy all shared memory areas that
245 * have been created for us by the afs process.
246 */
247 for (;;) {
248 ret = recv_bin_buffer(fd, buf, sizeof(int));
249 if (ret <= 0)
250 goto out;
251 assert(ret == sizeof(int));
252 ret = *(int *) buf;
253 assert(ret > 0);
254 result_shmid = ret;
255 if (!dispatch_error) {
256 ret = dispatch_result(result_shmid, result_handler,
257 private_result_data);
258 if (ret < 0)
259 dispatch_error = 1;
260 }
261 ret = shm_destroy(result_shmid);
262 if (ret < 0)
263 PARA_CRIT_LOG("destroy result failed: %s\n",
264 para_strerror(-ret));
265 num_dispatched++;
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 < 0? ret : num_dispatched;
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 * \return The return value of the underlying call to \ref
292 * send_callback_request().
293 *
294 * \sa send_standard_callback_request(), send_callback_request().
295 */
296 int send_option_arg_callback_request(struct osl_object *options,
297 int argc, char * const * const argv, callback_function *f,
298 callback_result_handler *result_handler,
299 void *private_result_data)
300 {
301 char *p;
302 int i, ret;
303 struct osl_object query = {.size = options? options->size : 0};
304
305 for (i = 0; i < argc; i++)
306 query.size += strlen(argv[i]) + 1;
307 query.data = para_malloc(query.size);
308 p = query.data;
309 if (options) {
310 memcpy(query.data, options->data, options->size);
311 p += options->size;
312 }
313 for (i = 0; i < argc; i++) {
314 strcpy(p, argv[i]); /* OK */
315 p += strlen(argv[i]) + 1;
316 }
317 ret = send_callback_request(f, &query, result_handler,
318 private_result_data);
319 free(query.data);
320 return ret;
321 }
322
323 /**
324 * Send a callback request with an argument vector only.
325 *
326 * \param argc The same meaning as in send_option_arg_callback_request().
327 * \param argv The same meaning as in send_option_arg_callback_request().
328 * \param f The same meaning as in send_option_arg_callback_request().
329 * \param result_handler See \ref send_callback_request.
330 * \param private_result_data See \ref send_callback_request.
331 *
332 * This is similar to send_option_arg_callback_request(), but no options buffer
333 * is passed to the parent process.
334 *
335 * \return The return value of the underlying call to
336 * send_option_arg_callback_request().
337 */
338 int send_standard_callback_request(int argc, char * const * const argv,
339 callback_function *f, callback_result_handler *result_handler,
340 void *private_result_data)
341 {
342 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
343 private_result_data);
344 }
345
346 static int action_if_pattern_matches(struct osl_row *row, void *data)
347 {
348 struct pattern_match_data *pmd = data;
349 struct osl_object name_obj;
350 const char *p, *name;
351 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
352 const char *pattern_txt = (const char *)pmd->patterns.data;
353
354 if (ret < 0)
355 return ret;
356 name = (char *)name_obj.data;
357 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
358 return 1;
359 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
360 return pmd->action(pmd->table, row, name, pmd->data);
361 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
362 p += strlen(p) + 1) {
363 ret = fnmatch(p, name, pmd->fnmatch_flags);
364 if (ret == FNM_NOMATCH)
365 continue;
366 if (ret)
367 return -E_FNMATCH;
368 ret = pmd->action(pmd->table, row, name, pmd->data);
369 if (ret >= 0)
370 pmd->num_matches++;
371 return ret;
372 }
373 return 1;
374 }
375
376 /**
377 * Execute the given function for each matching row.
378 *
379 * \param pmd Describes what to match and how.
380 *
381 * \return Standard.
382 */
383 int for_each_matching_row(struct pattern_match_data *pmd)
384 {
385 if (pmd->pm_flags & PM_REVERSE_LOOP)
386 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
387 action_if_pattern_matches));
388 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
389 action_if_pattern_matches));
390 }
391
392 /**
393 * Compare two osl objects of string type.
394 *
395 * \param obj1 Pointer to the first object.
396 * \param obj2 Pointer to the second object.
397 *
398 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
399 * are taken into account.
400 *
401 * \return It returns an integer less than, equal to, or greater than zero if
402 * \a obj1 is found, respectively, to be less than, to match, or be greater than
403 * obj2.
404 *
405 * \sa strcmp(3), strncmp(3), osl_compare_func.
406 */
407 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
408 {
409 const char *str1 = (const char *)obj1->data;
410 const char *str2 = (const char *)obj2->data;
411 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
412 }
413
414 static int pass_afd(int fd, char *buf, size_t size)
415 {
416 struct msghdr msg = {.msg_iov = NULL};
417 struct cmsghdr *cmsg;
418 char control[255];
419 int ret;
420 struct iovec iov;
421
422 iov.iov_base = buf;
423 iov.iov_len = size;
424
425 msg.msg_iov = &iov;
426 msg.msg_iovlen = 1;
427
428 msg.msg_control = control;
429 msg.msg_controllen = sizeof(control);
430
431 cmsg = CMSG_FIRSTHDR(&msg);
432 cmsg->cmsg_level = SOL_SOCKET;
433 cmsg->cmsg_type = SCM_RIGHTS;
434 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
435 *(int *)CMSG_DATA(cmsg) = fd;
436
437 /* Sum of the length of all control messages in the buffer */
438 msg.msg_controllen = cmsg->cmsg_len;
439 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
440 ret = sendmsg(server_socket, &msg, 0);
441 if (ret < 0) {
442 ret = -ERRNO_TO_PARA_ERROR(errno);
443 return ret;
444 }
445 return 1;
446 }
447
448 /**
449 * Open the audio file with highest score.
450 *
451 * This stores all information for streaming the "best" audio file in a shared
452 * memory area. The id of that area and an open file descriptor for the next
453 * audio file are passed to the server process.
454 *
455 * \return Standard.
456 *
457 * \sa open_and_update_audio_file().
458 */
459 static int open_next_audio_file(void)
460 {
461 struct osl_row *aft_row;
462 struct audio_file_data afd;
463 int ret, shmid;
464 char buf[8];
465 long score;
466 again:
467 PARA_NOTICE_LOG("getting next audio file\n");
468 ret = score_get_best(&aft_row, &score);
469 if (ret < 0) {
470 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
471 goto no_admissible_files;
472 }
473 ret = open_and_update_audio_file(aft_row, score, &afd);
474 if (ret < 0) {
475 ret = score_delete(aft_row);
476 if (ret < 0) {
477 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
478 goto no_admissible_files;
479 }
480 goto again;
481 }
482 shmid = ret;
483 if (!write_ok(server_socket)) {
484 ret = -E_AFS_SOCKET;
485 goto destroy;
486 }
487 *(uint32_t *)buf = NEXT_AUDIO_FILE;
488 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
489 ret = pass_afd(afd.fd, buf, 8);
490 close(afd.fd);
491 if (ret >= 0)
492 return ret;
493 destroy:
494 shm_destroy(shmid);
495 return ret;
496 no_admissible_files:
497 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
498 *(uint32_t *)(buf + 4) = (uint32_t)0;
499 return write_all(server_socket, buf, 8);
500 }
501
502 /* Never fails if arg == NULL */
503 static int activate_mood_or_playlist(char *arg, int *num_admissible)
504 {
505 enum play_mode mode;
506 int ret;
507
508 if (!arg) {
509 ret = change_current_mood(NULL); /* always successful */
510 mode = PLAY_MODE_MOOD;
511 } else {
512 if (!strncmp(arg, "p/", 2)) {
513 ret = playlist_open(arg + 2);
514 mode = PLAY_MODE_PLAYLIST;
515 } else if (!strncmp(arg, "m/", 2)) {
516 ret = change_current_mood(arg + 2);
517 mode = PLAY_MODE_MOOD;
518 } else
519 return -E_AFS_SYNTAX;
520 if (ret < 0)
521 return ret;
522 }
523 if (num_admissible)
524 *num_admissible = ret;
525 current_play_mode = mode;
526 if (arg != current_mop) {
527 free(current_mop);
528 if (arg) {
529 current_mop = para_strdup(arg);
530 mutex_lock(mmd_mutex);
531 strncpy(mmd->afs_mode_string, arg,
532 sizeof(mmd->afs_mode_string));
533 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
534 mutex_unlock(mmd_mutex);
535 } else {
536 mutex_lock(mmd_mutex);
537 strcpy(mmd->afs_mode_string, "dummy");
538 mutex_unlock(mmd_mutex);
539 current_mop = NULL;
540 }
541 }
542 return 1;
543 }
544
545 static void com_select_callback(int fd, const struct osl_object *query)
546 {
547 struct para_buffer pb = {
548 .max_size = shm_get_shmmax(),
549 .private_data = &fd,
550 .max_size_handler = pass_buffer_as_shm
551 };
552 char *arg = query->data;
553 int num_admissible, ret, ret2;
554
555 ret = clear_score_table();
556 if (ret < 0) {
557 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
558 goto out;
559 }
560 if (current_play_mode == PLAY_MODE_MOOD)
561 close_current_mood();
562 else
563 playlist_close();
564 ret = activate_mood_or_playlist(arg, &num_admissible);
565 if (ret < 0) {
566 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
567 para_strerror(-ret), current_mop?
568 current_mop : "dummy");
569 ret = activate_mood_or_playlist(current_mop, &num_admissible);
570 if (ret < 0) {
571 if (ret2 >= 0)
572 ret2 = para_printf(&pb, "failed, switching to dummy\n");
573 activate_mood_or_playlist(NULL, &num_admissible);
574 }
575 } else
576 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
577 current_mop : "dummy mood", num_admissible);
578 out:
579 if (ret2 >= 0 && pb.offset)
580 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
581 free(pb.buf);
582 }
583
584 /**
585 * Result handler for sending data to the para_client process.
586 *
587 * \param result The data to be sent.
588 * \param private Pointer to the context.
589 *
590 * \return The return value of the underlying call to sc_send_bin_buffer().
591 *
592 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
593 */
594 int sc_send_result(struct osl_object *result, void *private)
595 {
596 struct command_context *cc = private;
597 int ret;
598
599 if (!result->size)
600 return 1;
601 ret = sc_send_bin_buffer(&cc->scc, result->data, result->size);
602 if (ret < 0 || ret == result->size)
603 return ret;
604 return -E_SHORT_WRITE;
605 }
606
607 int com_select(struct command_context *cc)
608 {
609 struct osl_object query;
610
611 if (cc->argc != 2)
612 return -E_AFS_SYNTAX;
613 query.data = cc->argv[1];
614 query.size = strlen(cc->argv[1]) + 1;
615 return send_callback_request(com_select_callback, &query,
616 &sc_send_result, cc);
617 }
618
619 static void init_admissible_files(char *arg)
620 {
621 if (activate_mood_or_playlist(arg, NULL) < 0)
622 activate_mood_or_playlist(NULL, NULL); /* always successful */
623 }
624
625 static int setup_command_socket_or_die(void)
626 {
627 int ret, socket_fd;
628 char *socket_name = conf.afs_socket_arg;
629 struct sockaddr_un unix_addr;
630
631 unlink(socket_name);
632 ret = create_local_socket(socket_name, &unix_addr,
633 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
634 if (ret < 0) {
635 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
636 exit(EXIT_FAILURE);
637 }
638 socket_fd = ret;
639 if (listen(socket_fd , 5) < 0) {
640 PARA_EMERG_LOG("can not listen on socket\n");
641 exit(EXIT_FAILURE);
642 }
643 ret = mark_fd_nonblocking(socket_fd);
644 if (ret < 0) {
645 close(socket_fd);
646 return ret;
647 }
648 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
649 socket_fd);
650 return socket_fd;
651 }
652
653 static void close_afs_tables(void)
654 {
655 int i;
656 PARA_NOTICE_LOG("closing afs_tables\n");
657 for (i = 0; i < NUM_AFS_TABLES; i++)
658 afs_tables[i].close();
659 }
660
661 static char *database_dir;
662
663 static void get_database_dir(void)
664 {
665 if (!database_dir) {
666 if (conf.afs_database_dir_given)
667 database_dir = para_strdup(conf.afs_database_dir_arg);
668 else {
669 char *home = para_homedir();
670 database_dir = make_message(
671 "%s/.paraslash/afs_database-0.4", home);
672 free(home);
673 }
674 }
675 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
676 }
677
678 static int make_database_dir(void)
679 {
680 int ret;
681
682 get_database_dir();
683 ret = para_mkdir(database_dir, 0777);
684 if (ret >= 0 || is_errno(-ret, EEXIST))
685 return 1;
686 return ret;
687 }
688
689 static int open_afs_tables(void)
690 {
691 int i, ret;
692
693 get_database_dir();
694 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
695 database_dir);
696 for (i = 0; i < NUM_AFS_TABLES; i++) {
697 ret = afs_tables[i].open(database_dir);
698 if (ret >= 0)
699 continue;
700 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
701 para_strerror(-ret));
702 break;
703 }
704 if (ret >= 0)
705 return ret;
706 while (i)
707 afs_tables[--i].close();
708 return ret;
709 }
710
711 static void signal_pre_select(struct sched *s, struct task *t)
712 {
713 struct signal_task *st = container_of(t, struct signal_task, task);
714 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
715 }
716
717 static void afs_signal_post_select(struct sched *s, struct task *t)
718 {
719 int signum;
720
721 if (getppid() == 1) {
722 PARA_EMERG_LOG("para_server died\n");
723 goto shutdown;
724 }
725 signum = para_next_signal(&s->rfds);
726 if (signum == 0)
727 return;
728 if (signum == SIGHUP) {
729 close_afs_tables();
730 parse_config_or_die(1);
731 t->error = open_afs_tables();
732 if (t->error < 0)
733 return;
734 init_admissible_files(current_mop);
735 return;
736 }
737 PARA_EMERG_LOG("terminating on signal %d\n", signum);
738 shutdown:
739 sched_shutdown(s);
740 t->error = -E_AFS_SIGNAL;
741 }
742
743 static void register_signal_task(struct sched *s)
744 {
745 struct signal_task *st = &signal_task_struct;
746
747 para_sigaction(SIGPIPE, SIG_IGN);
748 st->fd = para_signal_init();
749 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
750 para_install_sighandler(SIGINT);
751 para_install_sighandler(SIGTERM);
752 para_install_sighandler(SIGHUP);
753
754 st->task.pre_select = signal_pre_select;
755 st->task.post_select = afs_signal_post_select;
756 sprintf(st->task.status, "signal task");
757 register_task(s, &st->task);
758 }
759
760 static struct list_head afs_client_list;
761
762 /** Describes on connected afs client. */
763 struct afs_client {
764 /** Position in the afs client list. */
765 struct list_head node;
766 /** The socket file descriptor for this client. */
767 int fd;
768 /** The time the client connected. */
769 struct timeval connect_time;
770 };
771
772 static void command_pre_select(struct sched *s, struct task *t)
773 {
774 struct command_task *ct = container_of(t, struct command_task, task);
775 struct afs_client *client;
776
777 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
778 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
779 list_for_each_entry(client, &afs_client_list, node)
780 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
781 }
782
783 /**
784 * Send data as shared memory to a file descriptor.
785 *
786 * \param buf The buffer holding the data to be sent.
787 * \param size The size of \a buf.
788 * \param fd_ptr A pointer to the file descriptor.
789 *
790 * This function is used as the \a max_size handler in a \ref para_buffer
791 * structure. If used this way, it is called by \ref para_printf() whenever
792 * the buffer passed to para_printf() is about to exceed its maximal size.
793 *
794 * This function creates a shared memory area large enough to hold
795 * the content given by \a buf and \a size and sends the identifier
796 * of this area to the file descriptor given by \a fd_ptr.
797 *
798 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
799 * and positive on success.
800 */
801 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
802 {
803 int ret, shmid, fd = *(int *)fd_ptr;
804 void *shm;
805 struct callback_result *cr;
806
807 if (!buf || !size)
808 return 0;
809 ret = shm_new(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 = size;
818 memcpy(shm + sizeof(*cr), buf, size);
819 ret = shm_detach(shm);
820 if (ret < 0)
821 goto err;
822 ret = write_all(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 int call_callback(int fd, int query_shmid)
837 {
838 void *query_shm;
839 struct callback_query *cq;
840 struct osl_object query;
841 int ret;
842
843 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
844 if (ret < 0)
845 return ret;
846 cq = query_shm;
847 query.data = (char *)query_shm + sizeof(*cq);
848 query.size = cq->query_size;
849 cq->handler(fd, &query);
850 return shm_detach(query_shm);
851 }
852
853 static int execute_server_command(fd_set *rfds)
854 {
855 char buf[8];
856 size_t n;
857 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
858
859 if (ret < 0 || n == 0)
860 return ret;
861 buf[n] = '\0';
862 if (strcmp(buf, "new"))
863 return -E_BAD_CMD;
864 return open_next_audio_file();
865 }
866
867 /* returns 0 if no data available, 1 else */
868 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
869 {
870 uint32_t cookie;
871 int query_shmid;
872 char buf[sizeof(cookie) + sizeof(query_shmid)];
873 size_t n;
874 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
875
876 if (ret < 0)
877 goto err;
878 if (n == 0)
879 return 0;
880 if (n != sizeof(buf)) {
881 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
882 ret, (long unsigned) sizeof(buf));
883 return 1;
884 }
885 cookie = *(uint32_t *)buf;
886 if (cookie != expected_cookie) {
887 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
888 (unsigned)cookie, (unsigned)expected_cookie);
889 return 1;
890 }
891 query_shmid = *(int *)(buf + sizeof(cookie));
892 if (query_shmid < 0) {
893 PARA_WARNING_LOG("received invalid query shmid %d)\n",
894 query_shmid);
895 return 1;
896 }
897 ret = call_callback(fd, query_shmid);
898 if (ret >= 0)
899 return 1;
900 err:
901 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
902 return 1;
903 }
904
905 /** Shutdown connection if query has not arrived until this many seconds. */
906 #define AFS_CLIENT_TIMEOUT 3
907
908 static void command_post_select(struct sched *s, struct task *t)
909 {
910 struct command_task *ct = container_of(t, struct command_task, task);
911 struct sockaddr_un unix_addr;
912 struct afs_client *client, *tmp;
913 int fd, ret;
914
915 ret = execute_server_command(&s->rfds);
916 if (ret < 0) {
917 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
918 sched_shutdown(s);
919 return;
920 }
921 /* Check the list of connected clients. */
922 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
923 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
924 if (ret == 0) { /* prevent bogus connection flooding */
925 struct timeval diff;
926 tv_diff(now, &client->connect_time, &diff);
927 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
928 continue;
929 PARA_WARNING_LOG("connection timeout\n");
930 }
931 close(client->fd);
932 list_del(&client->node);
933 free(client);
934 }
935 /* Accept connections on the local socket. */
936 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
937 if (ret < 0)
938 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
939 if (ret <= 0)
940 return;
941 ret = mark_fd_nonblocking(fd);
942 if (ret < 0) {
943 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
944 close(fd);
945 return;
946 }
947 client = para_malloc(sizeof(*client));
948 client->fd = fd;
949 client->connect_time = *now;
950 para_list_add(&client->node, &afs_client_list);
951 }
952
953 static void register_command_task(uint32_t cookie, struct sched *s)
954 {
955 struct command_task *ct = &command_task_struct;
956 ct->fd = setup_command_socket_or_die();
957 ct->cookie = cookie;
958
959 ct->task.pre_select = command_pre_select;
960 ct->task.post_select = command_post_select;
961 sprintf(ct->task.status, "afs command task");
962 register_task(s, &ct->task);
963 }
964
965 /**
966 * Initialize the audio file selector process.
967 *
968 * \param cookie The value used for "authentication".
969 * \param socket_fd File descriptor used for communication with the server.
970 */
971 __noreturn void afs_init(uint32_t cookie, int socket_fd)
972 {
973 static struct sched s;
974 int i, ret;
975
976 register_signal_task(&s);
977 INIT_LIST_HEAD(&afs_client_list);
978 for (i = 0; i < NUM_AFS_TABLES; i++)
979 afs_tables[i].init(&afs_tables[i]);
980 ret = open_afs_tables();
981 if (ret < 0)
982 goto out;
983 server_socket = socket_fd;
984 ret = mark_fd_nonblocking(server_socket);
985 if (ret < 0)
986 goto out_close;
987 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
988 server_socket, (unsigned) cookie);
989 init_admissible_files(conf.afs_initial_mode_arg);
990 register_command_task(cookie, &s);
991 s.default_timeout.tv_sec = 0;
992 s.default_timeout.tv_usec = 999 * 1000;
993 ret = schedule(&s);
994 out_close:
995 close_afs_tables();
996 out:
997 if (ret < 0)
998 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
999 exit(EXIT_FAILURE);
1000 }
1001
1002 static void create_tables_callback(int fd, const struct osl_object *query)
1003 {
1004 uint32_t table_mask = *(uint32_t *)query->data;
1005 int i, ret;
1006 struct para_buffer pb = {.buf = NULL};
1007
1008 close_afs_tables();
1009 for (i = 0; i < NUM_AFS_TABLES; i++) {
1010 struct afs_table *t = &afs_tables[i];
1011
1012 if (!(table_mask & (1 << i)))
1013 continue;
1014 if (!t->create)
1015 continue;
1016 ret = t->create(database_dir);
1017 if (ret < 0)
1018 goto out;
1019 para_printf(&pb, "successfully created %s table\n", t->name);
1020 }
1021 ret = open_afs_tables();
1022 out:
1023 if (ret < 0)
1024 para_printf(&pb, "%s\n", para_strerror(-ret));
1025 if (pb.buf)
1026 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1027 free(pb.buf);
1028 }
1029
1030 int com_init(struct command_context *cc)
1031 {
1032 int i, j, ret;
1033 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1034 struct osl_object query = {.data = &table_mask,
1035 .size = sizeof(table_mask)};
1036
1037 ret = make_database_dir();
1038 if (ret < 0)
1039 return ret;
1040 if (cc->argc != 1) {
1041 table_mask = 0;
1042 for (i = 1; i < cc->argc; i++) {
1043 for (j = 0; j < NUM_AFS_TABLES; j++) {
1044 struct afs_table *t = &afs_tables[j];
1045
1046 if (strcmp(cc->argv[i], t->name))
1047 continue;
1048 table_mask |= (1 << j);
1049 break;
1050 }
1051 if (j == NUM_AFS_TABLES)
1052 return -E_BAD_TABLE_NAME;
1053 }
1054 }
1055 ret = send_callback_request(create_tables_callback, &query,
1056 sc_send_result, cc);
1057 if (ret < 0)
1058 /* ignore return value */
1059 sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(-ret));
1060 return ret;
1061 }
1062
1063 /**
1064 * Flags for the check command.
1065 *
1066 * \sa com_check().
1067 */
1068 enum com_check_flags {
1069 /** Check the audio file table. */
1070 CHECK_AFT = 1,
1071 /** Check the mood table. */
1072 CHECK_MOODS = 2,
1073 /** Check the playlist table. */
1074 CHECK_PLAYLISTS = 4
1075 };
1076
1077 int com_check(struct command_context *cc)
1078 {
1079 unsigned flags = 0;
1080 int i, ret;
1081
1082 for (i = 1; i < cc->argc; i++) {
1083 const char *arg = cc->argv[i];
1084 if (arg[0] != '-')
1085 break;
1086 if (!strcmp(arg, "--")) {
1087 i++;
1088 break;
1089 }
1090 if (!strcmp(arg, "-a")) {
1091 flags |= CHECK_AFT;
1092 continue;
1093 }
1094 if (!strcmp(arg, "-p")) {
1095 flags |= CHECK_PLAYLISTS;
1096 continue;
1097 }
1098 if (!strcmp(arg, "-m")) {
1099 flags |= CHECK_MOODS;
1100 continue;
1101 }
1102 return -E_AFS_SYNTAX;
1103 }
1104 if (i < cc->argc)
1105 return -E_AFS_SYNTAX;
1106 if (!flags)
1107 flags = ~0U;
1108 if (flags & CHECK_AFT) {
1109 ret = send_callback_request(aft_check_callback, NULL,
1110 sc_send_result, cc);
1111 if (ret < 0)
1112 return ret;
1113 }
1114 if (flags & CHECK_PLAYLISTS) {
1115 ret = send_callback_request(playlist_check_callback,
1116 NULL, sc_send_result, cc);
1117 if (ret < 0)
1118 return ret;
1119 }
1120 if (flags & CHECK_MOODS) {
1121 ret = send_callback_request(mood_check_callback, NULL,
1122 sc_send_result, cc);
1123 if (ret < 0)
1124 return ret;
1125 }
1126 return 1;
1127 }
1128
1129 /**
1130 * The afs event dispatcher.
1131 *
1132 * \param event Type of the event.
1133 * \param pb May be \p NULL.
1134 * \param data Type depends on \a event.
1135 *
1136 * This function calls the table handlers of all tables and passes \a pb and \a
1137 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1138 */
1139 void afs_event(enum afs_events event, struct para_buffer *pb,
1140 void *data)
1141 {
1142 int i, ret;
1143
1144 for (i = 0; i < NUM_AFS_TABLES; i++) {
1145 struct afs_table *t = &afs_tables[i];
1146 if (!t->event_handler)
1147 continue;
1148 ret = t->event_handler(event, pb, data);
1149 if (ret < 0)
1150 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1151 event, para_strerror(-ret));
1152 }
1153 }
1154
1155 /**
1156 * Dummy event handler for the images table.
1157 *
1158 * \param event Unused.
1159 * \param pb Unused.
1160 * \param data Unused.
1161 *
1162 * \return The images table does not honor events, so this handler always
1163 * returns success.
1164 */
1165 __a_const int images_event_handler(__a_unused enum afs_events event,
1166 __a_unused struct para_buffer *pb, __a_unused void *data)
1167 {
1168 return 1;
1169 }
1170
1171 /**
1172 * Dummy event handler for the lyrics table.
1173 *
1174 * \param event Unused.
1175 * \param pb Unused.
1176 * \param data Unused.
1177 *
1178 * \return The lyrics table does not honor events, so this handler always
1179 * returns success.
1180 */
1181 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1182 __a_unused struct para_buffer *pb, __a_unused void *data)
1183 {
1184 return 1;
1185 }