Improve signal init and shutdown.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18
19 #include "server.cmdline.h"
20 #include "para.h"
21 #include "error.h"
22 #include "crypt.h"
23 #include "string.h"
24 #include "afh.h"
25 #include "afs.h"
26 #include "server.h"
27 #include "net.h"
28 #include "ipc.h"
29 #include "list.h"
30 #include "sched.h"
31 #include "fd.h"
32 #include "signal.h"
33 #include "mood.h"
34 #include "sideband.h"
35 #include "command.h"
36
37 /** The osl tables used by afs. \sa blob.c. */
38 enum afs_table_num {
39 /** Contains audio file information. See aft.c. */
40 TBLNUM_AUDIO_FILES,
41 /** The table for the paraslash attributes. See attribute.c. */
42 TBLNUM_ATTRIBUTES,
43 /**
44 * Paraslash's scoring system is based on Gaussian normal
45 * distributions, and the relevant data is stored in the rbtrees of an
46 * osl table containing only volatile columns. See score.c for
47 * details.
48 */
49 TBLNUM_SCORES,
50 /**
51 * A standard blob table containing the mood definitions. For details
52 * see mood.c.
53 */
54 TBLNUM_MOODS,
55 /** A blob table containing lyrics on a per-song basis. */
56 TBLNUM_LYRICS,
57 /** Another blob table for images (for example album cover art). */
58 TBLNUM_IMAGES,
59 /** Yet another blob table for storing standard playlists. */
60 TBLNUM_PLAYLIST,
61 /** How many tables are in use? */
62 NUM_AFS_TABLES
63 };
64
65 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
66 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
67 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
68 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
69 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
70 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
71 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
72 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
73 };
74
75 struct command_task {
76 /** The file descriptor for the local socket. */
77 int fd;
78 /**
79 * Value sent by the command handlers to identify themselves as
80 * children of the running para_server.
81 */
82 uint32_t cookie;
83 /** The associated task structure. */
84 struct task *task;
85 };
86
87 extern int mmd_mutex;
88 extern struct misc_meta_data *mmd;
89
90 static int server_socket;
91 static struct command_task command_task_struct;
92 static struct signal_task *signal_task;
93
94 static enum play_mode current_play_mode;
95 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
96
97 /**
98 * A random number used to "authenticate" the connection.
99 *
100 * para_server picks this number by random before forking the afs process. The
101 * command handlers write this number together with the id of the shared memory
102 * area containing the query. This way, a malicious local user has to know this
103 * number to be able to cause the afs process to crash by sending fake queries.
104 */
105 extern uint32_t afs_socket_cookie;
106
107 /**
108 * Struct to let command handlers execute a callback in afs context.
109 *
110 * Commands that need to change the state of afs can't change the relevant data
111 * structures directly because commands are executed in a child process, i.e.
112 * they get their own virtual address space.
113 *
114 * This structure is used by \p send_callback_request() (executed from handler
115 * context) in order to let the afs process call the specified function. An
116 * instance of that structure is written to a shared memory area together with
117 * the arguments to the callback function. The identifier of the shared memory
118 * area is written to the command socket.
119 *
120 * The afs process accepts connections on the command socket and reads the
121 * shared memory id, attaches the corresponding area, calls the given handler to
122 * perform the desired action and to optionally compute a result.
123 *
124 * The result and a \p callback_result structure is then written to another
125 * shared memory area. The identifier for that area is written to the handler's
126 * command socket, so that the handler process can read the id, attach the
127 * shared memory area and use the result.
128 *
129 * \sa struct callback_result.
130 */
131 struct callback_query {
132 /** The function to be called. */
133 callback_function *handler;
134 /** The number of bytes of the query */
135 size_t query_size;
136 };
137
138 /**
139 * Structure embedded in the result of a callback.
140 *
141 * If the callback produced a result, an instance of that structure is embedded
142 * into the shared memory area holding the result, mainly to let the command
143 * handler know the size of the result.
144 *
145 * \sa struct callback_query.
146 */
147 struct callback_result {
148 /** The number of bytes of the result. */
149 size_t result_size;
150 /** The band designator (loglevel for the result). */
151 uint8_t band;
152 };
153
154 static int dispatch_result(int result_shmid, callback_result_handler *handler,
155 void *private_result_data)
156 {
157 struct osl_object result;
158 void *result_shm;
159 /* must attach r/w as result.data might get encrypted in-place. */
160 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
161 struct callback_result *cr = result_shm;
162
163 if (ret < 0) {
164 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
165 return ret;
166 }
167 result.size = cr->result_size;
168 result.data = result_shm + sizeof(*cr);
169 if (result.size) {
170 assert(handler);
171 ret = handler(&result, cr->band, private_result_data);
172 if (ret < 0)
173 PARA_NOTICE_LOG("result handler error: %s\n",
174 para_strerror(-ret));
175 }
176 ret2 = shm_detach(result_shm);
177 if (ret2 < 0) {
178 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
179 if (ret >= 0)
180 ret = ret2;
181 }
182 return ret;
183 }
184
185 /**
186 * Ask the afs process to call a given function.
187 *
188 * \param f The function to be called.
189 * \param query Pointer to arbitrary data for the callback.
190 * \param result_handler Called for each shm area sent by the callback.
191 * \param private_result_data Passed verbatim to \a result_handler.
192 *
193 * This function creates a socket for communication with the afs process and a
194 * shared memory area (sma) to which the buffer pointed to by \a query is
195 * copied. It then notifies the afs process that the callback function \a f
196 * should be executed by sending the shared memory identifier (shmid) to the
197 * socket.
198
199 * If the callback produces a result, it sends any number of shared memory
200 * identifiers back via the socket. For each such identifier received, \a
201 * result_handler is called. The contents of the sma identified by the received
202 * shmid are passed to that function as an osl object. The private_result_data
203 * pointer is passed as the second argument to \a result_handler.
204 *
205 * \return Number of shared memory areas dispatched on success, negative on errors.
206 *
207 * \sa send_option_arg_callback_request(), send_standard_callback_request().
208 */
209 int send_callback_request(callback_function *f, struct osl_object *query,
210 callback_result_handler *result_handler,
211 void *private_result_data)
212 {
213 struct callback_query *cq;
214 int ret, fd = -1, query_shmid, result_shmid;
215 void *query_shm;
216 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
217 size_t query_shm_size = sizeof(*cq);
218 int dispatch_error = 0, num_dispatched = 0;
219
220 if (query)
221 query_shm_size += query->size;
222 ret = shm_new(query_shm_size);
223 if (ret < 0)
224 return ret;
225 query_shmid = ret;
226 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
227 if (ret < 0)
228 goto out;
229 cq = query_shm;
230 cq->handler = f;
231 cq->query_size = query_shm_size - sizeof(*cq);
232
233 if (query)
234 memcpy(query_shm + sizeof(*cq), query->data, query->size);
235 ret = shm_detach(query_shm);
236 if (ret < 0)
237 goto out;
238
239 *(uint32_t *) buf = afs_socket_cookie;
240 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
241
242 ret = connect_local_socket(conf.afs_socket_arg);
243 if (ret < 0)
244 goto out;
245 fd = ret;
246 ret = write_all(fd, buf, sizeof(buf));
247 if (ret < 0)
248 goto out;
249 /*
250 * Read all shmids from afs.
251 *
252 * Even if the dispatcher returns an error we _must_ continue to read
253 * shmids from fd so that we can destroy all shared memory areas that
254 * have been created for us by the afs process.
255 */
256 for (;;) {
257 ret = recv_bin_buffer(fd, buf, sizeof(int));
258 if (ret <= 0)
259 goto out;
260 assert(ret == sizeof(int));
261 ret = *(int *) buf;
262 assert(ret > 0);
263 result_shmid = ret;
264 if (!dispatch_error) {
265 ret = dispatch_result(result_shmid, result_handler,
266 private_result_data);
267 if (ret < 0)
268 dispatch_error = 1;
269 }
270 ret = shm_destroy(result_shmid);
271 if (ret < 0)
272 PARA_CRIT_LOG("destroy result failed: %s\n",
273 para_strerror(-ret));
274 num_dispatched++;
275 }
276 out:
277 if (shm_destroy(query_shmid) < 0)
278 PARA_CRIT_LOG("shm destroy error\n");
279 if (fd >= 0)
280 close(fd);
281 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
282 return ret < 0? ret : num_dispatched;
283 }
284
285 /**
286 * Send a callback request passing an options structure and an argument vector.
287 *
288 * \param options pointer to an arbitrary data structure.
289 * \param argc Argument count.
290 * \param argv Standard argument vector.
291 * \param f The callback function.
292 * \param result_handler See \ref send_callback_request.
293 * \param private_result_data See \ref send_callback_request.
294 *
295 * Some command handlers pass command-specific options to a callback, together
296 * with a list of further arguments (often a list of audio files). This
297 * function allows to pass an arbitrary structure (given as an osl object) and
298 * a usual argument vector to the specified callback.
299 *
300 * \return The return value of the underlying call to \ref
301 * send_callback_request().
302 *
303 * \sa send_standard_callback_request(), send_callback_request().
304 */
305 int send_option_arg_callback_request(struct osl_object *options,
306 int argc, char * const * const argv, callback_function *f,
307 callback_result_handler *result_handler,
308 void *private_result_data)
309 {
310 char *p;
311 int i, ret;
312 struct osl_object query = {.size = options? options->size : 0};
313
314 for (i = 0; i < argc; i++)
315 query.size += strlen(argv[i]) + 1;
316 query.data = para_malloc(query.size);
317 p = query.data;
318 if (options) {
319 memcpy(query.data, options->data, options->size);
320 p += options->size;
321 }
322 for (i = 0; i < argc; i++) {
323 strcpy(p, argv[i]); /* OK */
324 p += strlen(argv[i]) + 1;
325 }
326 ret = send_callback_request(f, &query, result_handler,
327 private_result_data);
328 free(query.data);
329 return ret;
330 }
331
332 /**
333 * Send a callback request with an argument vector only.
334 *
335 * \param argc The same meaning as in send_option_arg_callback_request().
336 * \param argv The same meaning as in send_option_arg_callback_request().
337 * \param f The same meaning as in send_option_arg_callback_request().
338 * \param result_handler See \ref send_callback_request.
339 * \param private_result_data See \ref send_callback_request.
340 *
341 * This is similar to send_option_arg_callback_request(), but no options buffer
342 * is passed to the parent process.
343 *
344 * \return The return value of the underlying call to
345 * send_option_arg_callback_request().
346 */
347 int send_standard_callback_request(int argc, char * const * const argv,
348 callback_function *f, callback_result_handler *result_handler,
349 void *private_result_data)
350 {
351 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
352 private_result_data);
353 }
354
355 static int action_if_pattern_matches(struct osl_row *row, void *data)
356 {
357 struct pattern_match_data *pmd = data;
358 struct osl_object name_obj;
359 const char *p, *name;
360 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
361 const char *pattern_txt = (const char *)pmd->patterns.data;
362
363 if (ret < 0)
364 return ret;
365 name = (char *)name_obj.data;
366 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
367 return 1;
368 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
369 return pmd->action(pmd->table, row, name, pmd->data);
370 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
371 p += strlen(p) + 1) {
372 ret = fnmatch(p, name, pmd->fnmatch_flags);
373 if (ret == FNM_NOMATCH)
374 continue;
375 if (ret)
376 return -E_FNMATCH;
377 ret = pmd->action(pmd->table, row, name, pmd->data);
378 if (ret >= 0)
379 pmd->num_matches++;
380 return ret;
381 }
382 return 1;
383 }
384
385 /**
386 * Execute the given function for each matching row.
387 *
388 * \param pmd Describes what to match and how.
389 *
390 * \return Standard.
391 */
392 int for_each_matching_row(struct pattern_match_data *pmd)
393 {
394 if (pmd->pm_flags & PM_REVERSE_LOOP)
395 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
396 action_if_pattern_matches));
397 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
398 action_if_pattern_matches));
399 }
400
401 /**
402 * Compare two osl objects of string type.
403 *
404 * \param obj1 Pointer to the first object.
405 * \param obj2 Pointer to the second object.
406 *
407 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
408 * are taken into account.
409 *
410 * \return It returns an integer less than, equal to, or greater than zero if
411 * \a obj1 is found, respectively, to be less than, to match, or be greater than
412 * obj2.
413 *
414 * \sa strcmp(3), strncmp(3), osl_compare_func.
415 */
416 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
417 {
418 const char *str1 = (const char *)obj1->data;
419 const char *str2 = (const char *)obj2->data;
420 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
421 }
422
423 static int pass_afd(int fd, char *buf, size_t size)
424 {
425 struct msghdr msg = {.msg_iov = NULL};
426 struct cmsghdr *cmsg;
427 char control[255];
428 int ret;
429 struct iovec iov;
430
431 iov.iov_base = buf;
432 iov.iov_len = size;
433
434 msg.msg_iov = &iov;
435 msg.msg_iovlen = 1;
436
437 msg.msg_control = control;
438 msg.msg_controllen = sizeof(control);
439
440 cmsg = CMSG_FIRSTHDR(&msg);
441 cmsg->cmsg_level = SOL_SOCKET;
442 cmsg->cmsg_type = SCM_RIGHTS;
443 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
444 *(int *)CMSG_DATA(cmsg) = fd;
445
446 /* Sum of the length of all control messages in the buffer */
447 msg.msg_controllen = cmsg->cmsg_len;
448 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
449 ret = sendmsg(server_socket, &msg, 0);
450 if (ret < 0) {
451 ret = -ERRNO_TO_PARA_ERROR(errno);
452 return ret;
453 }
454 return 1;
455 }
456
457 /**
458 * Open the audio file with highest score.
459 *
460 * This stores all information for streaming the "best" audio file in a shared
461 * memory area. The id of that area and an open file descriptor for the next
462 * audio file are passed to the server process.
463 *
464 * \return Standard.
465 *
466 * \sa open_and_update_audio_file().
467 */
468 static int open_next_audio_file(void)
469 {
470 struct osl_row *aft_row;
471 struct audio_file_data afd;
472 int ret, shmid;
473 char buf[8];
474 long score;
475 again:
476 PARA_NOTICE_LOG("getting next audio file\n");
477 ret = score_get_best(&aft_row, &score);
478 if (ret < 0) {
479 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
480 goto no_admissible_files;
481 }
482 ret = open_and_update_audio_file(aft_row, score, &afd);
483 if (ret < 0) {
484 ret = score_delete(aft_row);
485 if (ret < 0) {
486 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
487 goto no_admissible_files;
488 }
489 goto again;
490 }
491 shmid = ret;
492 if (!write_ok(server_socket)) {
493 ret = -E_AFS_SOCKET;
494 goto destroy;
495 }
496 *(uint32_t *)buf = NEXT_AUDIO_FILE;
497 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
498 ret = pass_afd(afd.fd, buf, 8);
499 close(afd.fd);
500 if (ret >= 0)
501 return ret;
502 destroy:
503 shm_destroy(shmid);
504 return ret;
505 no_admissible_files:
506 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
507 *(uint32_t *)(buf + 4) = (uint32_t)0;
508 return write_all(server_socket, buf, 8);
509 }
510
511 /* Never fails if arg == NULL */
512 static int activate_mood_or_playlist(char *arg, int *num_admissible)
513 {
514 enum play_mode mode;
515 int ret;
516
517 if (!arg) {
518 ret = change_current_mood(NULL); /* always successful */
519 mode = PLAY_MODE_MOOD;
520 } else {
521 if (!strncmp(arg, "p/", 2)) {
522 ret = playlist_open(arg + 2);
523 mode = PLAY_MODE_PLAYLIST;
524 } else if (!strncmp(arg, "m/", 2)) {
525 ret = change_current_mood(arg + 2);
526 mode = PLAY_MODE_MOOD;
527 } else
528 return -E_AFS_SYNTAX;
529 if (ret < 0)
530 return ret;
531 }
532 if (num_admissible)
533 *num_admissible = ret;
534 current_play_mode = mode;
535 if (arg != current_mop) {
536 free(current_mop);
537 if (arg) {
538 current_mop = para_strdup(arg);
539 mutex_lock(mmd_mutex);
540 strncpy(mmd->afs_mode_string, arg,
541 sizeof(mmd->afs_mode_string));
542 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
543 mutex_unlock(mmd_mutex);
544 } else {
545 mutex_lock(mmd_mutex);
546 strcpy(mmd->afs_mode_string, "dummy");
547 mutex_unlock(mmd_mutex);
548 current_mop = NULL;
549 }
550 }
551 return 1;
552 }
553
554 /**
555 * Result handler for sending data to the para_client process.
556 *
557 * \param result The data to be sent.
558 * \param band The band designator.
559 * \param private Pointer to the command context.
560 *
561 * \return The return value of the underlying call to \ref command.c::send_sb.
562 *
563 * \sa \ref callback_result_handler, \ref command.c::send_sb.
564 */
565 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
566 void *private)
567 {
568 struct command_context *cc = private;
569
570 assert(cc);
571 if (!result->size)
572 return 1;
573 return send_sb(&cc->scc, result->data, result->size, band, true);
574 }
575
576 static void com_select_callback(int fd, const struct osl_object *query)
577 {
578 struct para_buffer pb = {
579 .max_size = shm_get_shmmax(),
580 .private_data = &(struct afs_max_size_handler_data) {
581 .fd = fd,
582 .band = SBD_OUTPUT
583 },
584 .max_size_handler = afs_max_size_handler,
585 };
586 char *arg = query->data;
587 int num_admissible, ret, ret2;
588
589 ret = clear_score_table();
590 if (ret < 0) {
591 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
592 goto out;
593 }
594 if (current_play_mode == PLAY_MODE_MOOD)
595 close_current_mood();
596 else
597 playlist_close();
598 ret = activate_mood_or_playlist(arg, &num_admissible);
599 if (ret < 0) {
600 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
601 para_strerror(-ret), current_mop?
602 current_mop : "dummy");
603 ret = activate_mood_or_playlist(current_mop, &num_admissible);
604 if (ret < 0) {
605 if (ret2 >= 0)
606 ret2 = para_printf(&pb, "failed, switching to dummy\n");
607 activate_mood_or_playlist(NULL, &num_admissible);
608 }
609 } else
610 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
611 current_mop : "dummy mood", num_admissible);
612 out:
613 if (ret2 >= 0 && pb.offset)
614 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
615 free(pb.buf);
616 }
617
618 int com_select(struct command_context *cc)
619 {
620 struct osl_object query;
621
622 if (cc->argc != 2)
623 return -E_AFS_SYNTAX;
624 query.data = cc->argv[1];
625 query.size = strlen(cc->argv[1]) + 1;
626 return send_callback_request(com_select_callback, &query,
627 &afs_cb_result_handler, cc);
628 }
629
630 static void init_admissible_files(char *arg)
631 {
632 if (activate_mood_or_playlist(arg, NULL) < 0)
633 activate_mood_or_playlist(NULL, NULL); /* always successful */
634 }
635
636 static int setup_command_socket_or_die(void)
637 {
638 int ret, socket_fd;
639 char *socket_name = conf.afs_socket_arg;
640 struct sockaddr_un unix_addr;
641
642 unlink(socket_name);
643 ret = create_local_socket(socket_name, &unix_addr,
644 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
645 if (ret < 0) {
646 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
647 exit(EXIT_FAILURE);
648 }
649 socket_fd = ret;
650 if (listen(socket_fd , 5) < 0) {
651 PARA_EMERG_LOG("can not listen on socket\n");
652 exit(EXIT_FAILURE);
653 }
654 ret = mark_fd_nonblocking(socket_fd);
655 if (ret < 0) {
656 close(socket_fd);
657 return ret;
658 }
659 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
660 socket_fd);
661 return socket_fd;
662 }
663
664 static void close_afs_tables(void)
665 {
666 int i;
667 PARA_NOTICE_LOG("closing afs_tables\n");
668 for (i = 0; i < NUM_AFS_TABLES; i++)
669 afs_tables[i].close();
670 }
671
672 static char *database_dir;
673
674 static void get_database_dir(void)
675 {
676 if (!database_dir) {
677 if (conf.afs_database_dir_given)
678 database_dir = para_strdup(conf.afs_database_dir_arg);
679 else {
680 char *home = para_homedir();
681 database_dir = make_message(
682 "%s/.paraslash/afs_database-0.4", home);
683 free(home);
684 }
685 }
686 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
687 }
688
689 static int make_database_dir(void)
690 {
691 int ret;
692
693 get_database_dir();
694 ret = para_mkdir(database_dir, 0777);
695 if (ret >= 0 || is_errno(-ret, EEXIST))
696 return 1;
697 return ret;
698 }
699
700 static int open_afs_tables(void)
701 {
702 int i, ret;
703
704 get_database_dir();
705 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
706 database_dir);
707 for (i = 0; i < NUM_AFS_TABLES; i++) {
708 ret = afs_tables[i].open(database_dir);
709 if (ret >= 0)
710 continue;
711 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
712 para_strerror(-ret));
713 break;
714 }
715 if (ret >= 0)
716 return ret;
717 while (i)
718 afs_tables[--i].close();
719 return ret;
720 }
721
722 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
723 {
724 int signum, ret;
725
726 if (getppid() == 1) {
727 PARA_EMERG_LOG("para_server died\n");
728 goto shutdown;
729 }
730 signum = para_next_signal(&s->rfds);
731 if (signum == 0)
732 return 0;
733 if (signum == SIGHUP) {
734 close_afs_tables();
735 parse_config_or_die(1);
736 ret = open_afs_tables();
737 if (ret < 0)
738 return ret;
739 init_admissible_files(current_mop);
740 return 0;
741 }
742 PARA_EMERG_LOG("terminating on signal %d\n", signum);
743 shutdown:
744 task_notify_all(s, E_AFS_SIGNAL);
745 return -E_AFS_SIGNAL;
746 }
747
748 static void register_signal_task(struct sched *s)
749 {
750 para_sigaction(SIGPIPE, SIG_IGN);
751 signal_task = signal_init_or_die();
752 para_install_sighandler(SIGINT);
753 para_install_sighandler(SIGTERM);
754 para_install_sighandler(SIGHUP);
755
756 signal_task->task = task_register(&(struct task_info) {
757 .name = "signal",
758 .pre_select = signal_pre_select,
759 .post_select = afs_signal_post_select,
760 .context = signal_task,
761
762 }, s);
763 }
764
765 static struct list_head afs_client_list;
766
767 /** Describes one connected afs client. */
768 struct afs_client {
769 /** Position in the afs client list. */
770 struct list_head node;
771 /** The socket file descriptor for this client. */
772 int fd;
773 /** The time the client connected. */
774 struct timeval connect_time;
775 };
776
777 static void command_pre_select(struct sched *s, void *context)
778 {
779 struct command_task *ct = context;
780 struct afs_client *client;
781
782 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
783 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
784 list_for_each_entry(client, &afs_client_list, node)
785 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
786 }
787
788 /**
789 * Send data as shared memory to a file descriptor.
790 *
791 * \param fd File descriptor to send the shmid to.
792 * \param band The band designator for this data.
793 * \param buf The buffer holding the data to be sent.
794 * \param size The size of \a buf.
795 *
796 * This function creates a shared memory area large enough to hold
797 * the content given by \a buf and \a size and sends the identifier
798 * of this area to the file descriptor \a fd.
799 *
800 * It is called by the AFS max_size handler as well as directly by the AFS
801 * command callbacks to send command output to the command handlers.
802 *
803 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
804 * and positive on success.
805 */
806 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
807 {
808 int ret, shmid;
809 void *shm;
810 struct callback_result *cr;
811
812 if (!buf || !size)
813 return 0;
814 ret = shm_new(size + sizeof(*cr));
815 if (ret < 0)
816 return ret;
817 shmid = ret;
818 ret = shm_attach(shmid, ATTACH_RW, &shm);
819 if (ret < 0)
820 goto err;
821 cr = shm;
822 cr->result_size = size;
823 cr->band = band;
824 memcpy(shm + sizeof(*cr), buf, size);
825 ret = shm_detach(shm);
826 if (ret < 0)
827 goto err;
828 ret = write_all(fd, (char *)&shmid, sizeof(int));
829 if (ret >= 0)
830 return ret;
831 err:
832 if (shm_destroy(shmid) < 0)
833 PARA_ERROR_LOG("destroy result failed\n");
834 return ret;
835 }
836
837 /*
838 * On errors, negative value is written to fd.
839 * On success: If query produced a result, the result_shmid is written to fd.
840 * Otherwise, zero is written.
841 */
842 static int call_callback(int fd, int query_shmid)
843 {
844 void *query_shm;
845 struct callback_query *cq;
846 struct osl_object query;
847 int ret;
848
849 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
850 if (ret < 0)
851 return ret;
852 cq = query_shm;
853 query.data = (char *)query_shm + sizeof(*cq);
854 query.size = cq->query_size;
855 cq->handler(fd, &query);
856 return shm_detach(query_shm);
857 }
858
859 static int execute_server_command(fd_set *rfds)
860 {
861 char buf[8];
862 size_t n;
863 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
864
865 if (ret < 0 || n == 0)
866 return ret;
867 buf[n] = '\0';
868 if (strcmp(buf, "new"))
869 return -E_BAD_CMD;
870 return open_next_audio_file();
871 }
872
873 /* returns 0 if no data available, 1 else */
874 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
875 {
876 uint32_t cookie;
877 int query_shmid;
878 char buf[sizeof(cookie) + sizeof(query_shmid)];
879 size_t n;
880 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
881
882 if (ret < 0)
883 goto err;
884 if (n == 0)
885 return 0;
886 if (n != sizeof(buf)) {
887 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
888 ret, (long unsigned) sizeof(buf));
889 return 1;
890 }
891 cookie = *(uint32_t *)buf;
892 if (cookie != expected_cookie) {
893 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
894 (unsigned)cookie, (unsigned)expected_cookie);
895 return 1;
896 }
897 query_shmid = *(int *)(buf + sizeof(cookie));
898 if (query_shmid < 0) {
899 PARA_WARNING_LOG("received invalid query shmid %d)\n",
900 query_shmid);
901 return 1;
902 }
903 ret = call_callback(fd, query_shmid);
904 if (ret >= 0)
905 return 1;
906 err:
907 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
908 return 1;
909 }
910
911 /** Shutdown connection if query has not arrived until this many seconds. */
912 #define AFS_CLIENT_TIMEOUT 3
913
914 static int command_post_select(struct sched *s, void *context)
915 {
916 struct command_task *ct = context;
917 struct sockaddr_un unix_addr;
918 struct afs_client *client, *tmp;
919 int fd, ret;
920
921 ret = task_get_notification(ct->task);
922 if (ret < 0)
923 return ret;
924 ret = execute_server_command(&s->rfds);
925 if (ret < 0) {
926 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
927 task_notify_all(s, -ret);
928 return ret;
929 }
930 /* Check the list of connected clients. */
931 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
932 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
933 if (ret == 0) { /* prevent bogus connection flooding */
934 struct timeval diff;
935 tv_diff(now, &client->connect_time, &diff);
936 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
937 continue;
938 PARA_WARNING_LOG("connection timeout\n");
939 }
940 close(client->fd);
941 list_del(&client->node);
942 free(client);
943 }
944 /* Accept connections on the local socket. */
945 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
946 if (ret < 0)
947 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
948 if (ret <= 0)
949 return 0;
950 ret = mark_fd_nonblocking(fd);
951 if (ret < 0) {
952 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
953 close(fd);
954 return 0;
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 return 0;
961 }
962
963 static void register_command_task(uint32_t cookie, struct sched *s)
964 {
965 struct command_task *ct = &command_task_struct;
966 ct->fd = setup_command_socket_or_die();
967 ct->cookie = cookie;
968
969 ct->task = task_register(&(struct task_info) {
970 .name = "afs command",
971 .pre_select = command_pre_select,
972 .post_select = command_post_select,
973 .context = ct,
974 }, s);
975 }
976
977 /**
978 * Initialize the audio file selector process.
979 *
980 * \param cookie The value used for "authentication".
981 * \param socket_fd File descriptor used for communication with the server.
982 */
983 __noreturn void afs_init(uint32_t cookie, int socket_fd)
984 {
985 static struct sched s;
986 int i, ret;
987
988 register_signal_task(&s);
989 INIT_LIST_HEAD(&afs_client_list);
990 for (i = 0; i < NUM_AFS_TABLES; i++)
991 afs_tables[i].init(&afs_tables[i]);
992 ret = open_afs_tables();
993 if (ret < 0)
994 goto out;
995 server_socket = socket_fd;
996 ret = mark_fd_nonblocking(server_socket);
997 if (ret < 0)
998 goto out_close;
999 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1000 server_socket, (unsigned) cookie);
1001 init_admissible_files(conf.afs_initial_mode_arg);
1002 register_command_task(cookie, &s);
1003 s.default_timeout.tv_sec = 0;
1004 s.default_timeout.tv_usec = 999 * 1000;
1005 ret = schedule(&s);
1006 sched_shutdown(&s);
1007 out_close:
1008 close_afs_tables();
1009 out:
1010 if (ret < 0)
1011 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1012 exit(EXIT_FAILURE);
1013 }
1014
1015 static void create_tables_callback(int fd, const struct osl_object *query)
1016 {
1017 uint32_t table_mask = *(uint32_t *)query->data;
1018 int i, ret;
1019 struct para_buffer pb = {.buf = NULL};
1020
1021 close_afs_tables();
1022 for (i = 0; i < NUM_AFS_TABLES; i++) {
1023 struct afs_table *t = &afs_tables[i];
1024
1025 if (!(table_mask & (1 << i)))
1026 continue;
1027 if (!t->create)
1028 continue;
1029 ret = t->create(database_dir);
1030 if (ret < 0)
1031 goto out;
1032 para_printf(&pb, "successfully created %s table\n", t->name);
1033 }
1034 ret = open_afs_tables();
1035 out:
1036 if (ret < 0)
1037 para_printf(&pb, "%s\n", para_strerror(-ret));
1038 if (pb.buf)
1039 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
1040 free(pb.buf);
1041 }
1042
1043 int com_init(struct command_context *cc)
1044 {
1045 int i, j, ret;
1046 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1047 struct osl_object query = {.data = &table_mask,
1048 .size = sizeof(table_mask)};
1049
1050 ret = make_database_dir();
1051 if (ret < 0)
1052 return ret;
1053 if (cc->argc != 1) {
1054 table_mask = 0;
1055 for (i = 1; i < cc->argc; i++) {
1056 for (j = 0; j < NUM_AFS_TABLES; j++) {
1057 struct afs_table *t = &afs_tables[j];
1058
1059 if (strcmp(cc->argv[i], t->name))
1060 continue;
1061 table_mask |= (1 << j);
1062 break;
1063 }
1064 if (j == NUM_AFS_TABLES)
1065 return -E_BAD_TABLE_NAME;
1066 }
1067 }
1068 ret = send_callback_request(create_tables_callback, &query,
1069 afs_cb_result_handler, cc);
1070 return ret;
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(struct command_context *cc)
1088 {
1089 unsigned flags = 0;
1090 int i, ret;
1091
1092 for (i = 1; i < cc->argc; i++) {
1093 const char *arg = cc->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 < cc->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,
1120 afs_cb_result_handler, cc);
1121 if (ret < 0)
1122 return ret;
1123 }
1124 if (flags & CHECK_PLAYLISTS) {
1125 ret = send_callback_request(playlist_check_callback,
1126 NULL, afs_cb_result_handler, cc);
1127 if (ret < 0)
1128 return ret;
1129 }
1130 if (flags & CHECK_MOODS) {
1131 ret = send_callback_request(mood_check_callback, NULL,
1132 afs_cb_result_handler, cc);
1133 if (ret < 0)
1134 return ret;
1135 }
1136 return 1;
1137 }
1138
1139 /**
1140 * The afs event dispatcher.
1141 *
1142 * \param event Type of the event.
1143 * \param pb May be \p NULL.
1144 * \param data Type depends on \a event.
1145 *
1146 * This function calls the table handlers of all tables and passes \a pb and \a
1147 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1148 */
1149 void afs_event(enum afs_events event, struct para_buffer *pb,
1150 void *data)
1151 {
1152 int i, ret;
1153
1154 for (i = 0; i < NUM_AFS_TABLES; i++) {
1155 struct afs_table *t = &afs_tables[i];
1156 if (!t->event_handler)
1157 continue;
1158 ret = t->event_handler(event, pb, data);
1159 if (ret < 0)
1160 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1161 event, para_strerror(-ret));
1162 }
1163 }
1164
1165 /**
1166 * Dummy event handler for the images table.
1167 *
1168 * \param event Unused.
1169 * \param pb Unused.
1170 * \param data Unused.
1171 *
1172 * \return The images table does not honor events, so this handler always
1173 * returns success.
1174 */
1175 __a_const int images_event_handler(__a_unused enum afs_events event,
1176 __a_unused struct para_buffer *pb, __a_unused void *data)
1177 {
1178 return 1;
1179 }
1180
1181 /**
1182 * Dummy event handler for the lyrics table.
1183 *
1184 * \param event Unused.
1185 * \param pb Unused.
1186 * \param data Unused.
1187 *
1188 * \return The lyrics table does not honor events, so this handler always
1189 * returns success.
1190 */
1191 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1192 __a_unused struct para_buffer *pb, __a_unused void *data)
1193 {
1194 return 1;
1195 }