com_init: Remove pointless initialization.
[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 == 0 &&
369 (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING)) {
370 pmd->num_matches++;
371 return pmd->action(pmd->table, row, name, pmd->data);
372 }
373 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
374 p += strlen(p) + 1) {
375 ret = fnmatch(p, name, pmd->fnmatch_flags);
376 if (ret == FNM_NOMATCH)
377 continue;
378 if (ret)
379 return -E_FNMATCH;
380 ret = pmd->action(pmd->table, row, name, pmd->data);
381 if (ret >= 0)
382 pmd->num_matches++;
383 return ret;
384 }
385 return 1;
386 }
387
388 /**
389 * Execute the given function for each matching row.
390 *
391 * \param pmd Describes what to match and how.
392 *
393 * \return Standard.
394 */
395 int for_each_matching_row(struct pattern_match_data *pmd)
396 {
397 if (pmd->pm_flags & PM_REVERSE_LOOP)
398 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
399 action_if_pattern_matches));
400 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
401 action_if_pattern_matches));
402 }
403
404 /**
405 * Compare two osl objects of string type.
406 *
407 * \param obj1 Pointer to the first object.
408 * \param obj2 Pointer to the second object.
409 *
410 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
411 * are taken into account.
412 *
413 * \return It returns an integer less than, equal to, or greater than zero if
414 * \a obj1 is found, respectively, to be less than, to match, or be greater than
415 * obj2.
416 *
417 * \sa strcmp(3), strncmp(3), osl_compare_func.
418 */
419 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
420 {
421 const char *str1 = (const char *)obj1->data;
422 const char *str2 = (const char *)obj2->data;
423 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
424 }
425
426 static int pass_afd(int fd, char *buf, size_t size)
427 {
428 struct msghdr msg = {.msg_iov = NULL};
429 struct cmsghdr *cmsg;
430 char control[255];
431 int ret;
432 struct iovec iov;
433
434 iov.iov_base = buf;
435 iov.iov_len = size;
436
437 msg.msg_iov = &iov;
438 msg.msg_iovlen = 1;
439
440 msg.msg_control = control;
441 msg.msg_controllen = sizeof(control);
442
443 cmsg = CMSG_FIRSTHDR(&msg);
444 cmsg->cmsg_level = SOL_SOCKET;
445 cmsg->cmsg_type = SCM_RIGHTS;
446 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
447 *(int *)CMSG_DATA(cmsg) = fd;
448
449 /* Sum of the length of all control messages in the buffer */
450 msg.msg_controllen = cmsg->cmsg_len;
451 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
452 ret = sendmsg(server_socket, &msg, 0);
453 if (ret < 0) {
454 ret = -ERRNO_TO_PARA_ERROR(errno);
455 return ret;
456 }
457 return 1;
458 }
459
460 /**
461 * Pass the fd of the next audio file to the server process.
462 *
463 * This stores all information for streaming the "best" audio file in a shared
464 * memory area. The id of that area and an open file descriptor for the next
465 * audio file are passed to the server process.
466 *
467 * \return Standard.
468 *
469 * \sa open_and_update_audio_file().
470 */
471 static int open_next_audio_file(void)
472 {
473 struct audio_file_data afd;
474 int ret, shmid;
475 char buf[8];
476
477 ret = open_and_update_audio_file(&afd);
478 if (ret < 0) {
479 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
480 goto no_admissible_files;
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 /**
546 * Result handler for sending data to the para_client process.
547 *
548 * \param result The data to be sent.
549 * \param band The band designator.
550 * \param private Pointer to the command context.
551 *
552 * \return The return value of the underlying call to \ref command.c::send_sb.
553 *
554 * \sa \ref callback_result_handler, \ref command.c::send_sb.
555 */
556 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
557 void *private)
558 {
559 struct command_context *cc = private;
560
561 assert(cc);
562 if (!result->size)
563 return 1;
564 return send_sb(&cc->scc, result->data, result->size, band, true);
565 }
566
567 static void com_select_callback(int fd, const struct osl_object *query)
568 {
569 struct para_buffer pb = {
570 .max_size = shm_get_shmmax(),
571 .private_data = &(struct afs_max_size_handler_data) {
572 .fd = fd,
573 .band = SBD_OUTPUT
574 },
575 .max_size_handler = afs_max_size_handler,
576 };
577 char *arg = query->data;
578 int num_admissible, ret, ret2;
579
580 ret = clear_score_table();
581 if (ret < 0) {
582 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
583 goto out;
584 }
585 if (current_play_mode == PLAY_MODE_MOOD)
586 close_current_mood();
587 else
588 playlist_close();
589 ret = activate_mood_or_playlist(arg, &num_admissible);
590 if (ret < 0) {
591 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
592 para_strerror(-ret), current_mop?
593 current_mop : "dummy");
594 ret = activate_mood_or_playlist(current_mop, &num_admissible);
595 if (ret < 0) {
596 if (ret2 >= 0)
597 ret2 = para_printf(&pb, "failed, switching to dummy\n");
598 activate_mood_or_playlist(NULL, &num_admissible);
599 }
600 } else
601 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n",
602 current_mop? current_mop : "dummy mood",
603 num_admissible);
604 out:
605 if (ret2 >= 0 && pb.offset)
606 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
607 free(pb.buf);
608 }
609
610 int com_select(struct command_context *cc)
611 {
612 struct osl_object query;
613
614 if (cc->argc != 2)
615 return -E_AFS_SYNTAX;
616 query.data = cc->argv[1];
617 query.size = strlen(cc->argv[1]) + 1;
618 return send_callback_request(com_select_callback, &query,
619 &afs_cb_result_handler, cc);
620 }
621
622 static void init_admissible_files(char *arg)
623 {
624 if (activate_mood_or_playlist(arg, NULL) < 0)
625 activate_mood_or_playlist(NULL, NULL); /* always successful */
626 }
627
628 static int setup_command_socket_or_die(void)
629 {
630 int ret, socket_fd;
631 char *socket_name = conf.afs_socket_arg;
632
633 unlink(socket_name);
634 ret = create_local_socket(socket_name, 0);
635 if (ret < 0) {
636 ret = create_local_socket(socket_name,
637 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
638 if (ret < 0) {
639 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
640 socket_name);
641 exit(EXIT_FAILURE);
642 }
643 }
644 socket_fd = ret;
645 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
646 socket_fd);
647 return socket_fd;
648 }
649
650 static void close_afs_tables(void)
651 {
652 int i;
653 PARA_NOTICE_LOG("closing afs_tables\n");
654 for (i = 0; i < NUM_AFS_TABLES; i++)
655 afs_tables[i].close();
656 }
657
658 static char *database_dir;
659
660 static void get_database_dir(void)
661 {
662 if (!database_dir) {
663 if (conf.afs_database_dir_given)
664 database_dir = para_strdup(conf.afs_database_dir_arg);
665 else {
666 char *home = para_homedir();
667 database_dir = make_message(
668 "%s/.paraslash/afs_database-0.4", home);
669 free(home);
670 }
671 }
672 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
673 }
674
675 static int make_database_dir(void)
676 {
677 int ret;
678
679 get_database_dir();
680 ret = para_mkdir(database_dir, 0777);
681 if (ret >= 0 || is_errno(-ret, EEXIST))
682 return 1;
683 return ret;
684 }
685
686 static int open_afs_tables(void)
687 {
688 int i, ret;
689
690 get_database_dir();
691 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
692 database_dir);
693 for (i = 0; i < NUM_AFS_TABLES; i++) {
694 ret = afs_tables[i].open(database_dir);
695 if (ret >= 0)
696 continue;
697 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
698 para_strerror(-ret));
699 break;
700 }
701 if (ret >= 0)
702 return ret;
703 while (i)
704 afs_tables[--i].close();
705 return ret;
706 }
707
708 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
709 {
710 int signum, ret;
711
712 if (getppid() == 1) {
713 PARA_EMERG_LOG("para_server died\n");
714 goto shutdown;
715 }
716 signum = para_next_signal(&s->rfds);
717 if (signum == 0)
718 return 0;
719 if (signum == SIGHUP) {
720 close_afs_tables();
721 parse_config_or_die(1);
722 ret = open_afs_tables();
723 if (ret < 0)
724 return ret;
725 init_admissible_files(current_mop);
726 return 0;
727 }
728 PARA_EMERG_LOG("terminating on signal %d\n", signum);
729 shutdown:
730 task_notify_all(s, E_AFS_SIGNAL);
731 return -E_AFS_SIGNAL;
732 }
733
734 static void register_signal_task(struct sched *s)
735 {
736 para_sigaction(SIGPIPE, SIG_IGN);
737 signal_task = signal_init_or_die();
738 para_install_sighandler(SIGINT);
739 para_install_sighandler(SIGTERM);
740 para_install_sighandler(SIGHUP);
741
742 signal_task->task = task_register(&(struct task_info) {
743 .name = "signal",
744 .pre_select = signal_pre_select,
745 .post_select = afs_signal_post_select,
746 .context = signal_task,
747
748 }, s);
749 }
750
751 static struct list_head afs_client_list;
752
753 /** Describes one connected afs client. */
754 struct afs_client {
755 /** Position in the afs client list. */
756 struct list_head node;
757 /** The socket file descriptor for this client. */
758 int fd;
759 /** The time the client connected. */
760 struct timeval connect_time;
761 };
762
763 static void command_pre_select(struct sched *s, void *context)
764 {
765 struct command_task *ct = context;
766 struct afs_client *client;
767
768 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
769 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
770 list_for_each_entry(client, &afs_client_list, node)
771 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
772 }
773
774 /**
775 * Send data as shared memory to a file descriptor.
776 *
777 * \param fd File descriptor to send the shmid to.
778 * \param band The band designator for this data.
779 * \param buf The buffer holding the data to be sent.
780 * \param size The size of \a buf.
781 *
782 * This function creates a shared memory area large enough to hold
783 * the content given by \a buf and \a size and sends the identifier
784 * of this area to the file descriptor \a fd.
785 *
786 * It is called by the AFS max_size handler as well as directly by the AFS
787 * command callbacks to send command output to the command handlers.
788 *
789 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
790 * and positive on success.
791 */
792 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
793 {
794 int ret, shmid;
795 void *shm;
796 struct callback_result *cr;
797
798 if (!buf || !size)
799 return 0;
800 ret = shm_new(size + sizeof(*cr));
801 if (ret < 0)
802 return ret;
803 shmid = ret;
804 ret = shm_attach(shmid, ATTACH_RW, &shm);
805 if (ret < 0)
806 goto err;
807 cr = shm;
808 cr->result_size = size;
809 cr->band = band;
810 memcpy(shm + sizeof(*cr), buf, size);
811 ret = shm_detach(shm);
812 if (ret < 0)
813 goto err;
814 ret = write_all(fd, (char *)&shmid, sizeof(int));
815 if (ret >= 0)
816 return ret;
817 err:
818 if (shm_destroy(shmid) < 0)
819 PARA_ERROR_LOG("destroy result failed\n");
820 return ret;
821 }
822
823 /*
824 * On errors, negative value is written to fd.
825 * On success: If query produced a result, the result_shmid is written to fd.
826 * Otherwise, zero is written.
827 */
828 static int call_callback(int fd, int query_shmid)
829 {
830 void *query_shm;
831 struct callback_query *cq;
832 struct osl_object query;
833 int ret;
834
835 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
836 if (ret < 0)
837 return ret;
838 cq = query_shm;
839 query.data = (char *)query_shm + sizeof(*cq);
840 query.size = cq->query_size;
841 cq->handler(fd, &query);
842 return shm_detach(query_shm);
843 }
844
845 static int execute_server_command(fd_set *rfds)
846 {
847 char buf[8];
848 size_t n;
849 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
850
851 if (ret < 0 || n == 0)
852 return ret;
853 buf[n] = '\0';
854 if (strcmp(buf, "new"))
855 return -E_BAD_CMD;
856 return open_next_audio_file();
857 }
858
859 /* returns 0 if no data available, 1 else */
860 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
861 {
862 uint32_t cookie;
863 int query_shmid;
864 char buf[sizeof(cookie) + sizeof(query_shmid)];
865 size_t n;
866 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
867
868 if (ret < 0)
869 goto err;
870 if (n == 0)
871 return 0;
872 if (n != sizeof(buf)) {
873 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
874 ret, (long unsigned) sizeof(buf));
875 return 1;
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 1;
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 1;
888 }
889 ret = call_callback(fd, query_shmid);
890 if (ret >= 0)
891 return 1;
892 err:
893 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
894 return 1;
895 }
896
897 /** Shutdown connection if query has not arrived until this many seconds. */
898 #define AFS_CLIENT_TIMEOUT 3
899
900 static int command_post_select(struct sched *s, void *context)
901 {
902 struct command_task *ct = context;
903 struct sockaddr_un unix_addr;
904 struct afs_client *client, *tmp;
905 int fd, ret;
906
907 ret = task_get_notification(ct->task);
908 if (ret < 0)
909 return ret;
910 ret = execute_server_command(&s->rfds);
911 if (ret < 0) {
912 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
913 task_notify_all(s, -ret);
914 return ret;
915 }
916 /* Check the list of connected clients. */
917 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
918 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
919 if (ret == 0) { /* 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 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
932 if (ret < 0)
933 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
934 if (ret <= 0)
935 return 0;
936 ret = mark_fd_nonblocking(fd);
937 if (ret < 0) {
938 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
939 close(fd);
940 return 0;
941 }
942 client = para_malloc(sizeof(*client));
943 client->fd = fd;
944 client->connect_time = *now;
945 para_list_add(&client->node, &afs_client_list);
946 return 0;
947 }
948
949 static void register_command_task(uint32_t cookie, struct sched *s)
950 {
951 struct command_task *ct = &command_task_struct;
952 ct->fd = setup_command_socket_or_die();
953 ct->cookie = cookie;
954
955 ct->task = task_register(&(struct task_info) {
956 .name = "afs command",
957 .pre_select = command_pre_select,
958 .post_select = command_post_select,
959 .context = ct,
960 }, s);
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(&s);
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, &s);
989 s.default_timeout.tv_sec = 0;
990 s.default_timeout.tv_usec = 999 * 1000;
991 ret = schedule(&s);
992 sched_shutdown(&s);
993 out_close:
994 close_afs_tables();
995 out:
996 if (ret < 0)
997 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
998 exit(EXIT_FAILURE);
999 }
1000
1001 static void create_tables_callback(int fd, const struct osl_object *query)
1002 {
1003 uint32_t table_mask = *(uint32_t *)query->data;
1004 int i, ret;
1005 struct para_buffer pb = {
1006 .max_size = shm_get_shmmax(),
1007 .private_data = &(struct afs_max_size_handler_data) {
1008 .fd = fd,
1009 .band = SBD_OUTPUT
1010 }
1011 };
1012
1013 close_afs_tables();
1014 for (i = 0; i < NUM_AFS_TABLES; i++) {
1015 struct afs_table *t = &afs_tables[i];
1016
1017 if (!(table_mask & (1 << i)))
1018 continue;
1019 if (!t->create)
1020 continue;
1021 ret = t->create(database_dir);
1022 if (ret < 0)
1023 goto out;
1024 para_printf(&pb, "successfully created %s table\n", t->name);
1025 }
1026 ret = open_afs_tables();
1027 out:
1028 if (ret < 0)
1029 para_printf(&pb, "%s\n", para_strerror(-ret));
1030 if (pb.buf)
1031 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
1032 free(pb.buf);
1033 }
1034
1035 int com_init(struct command_context *cc)
1036 {
1037 int i, j, ret;
1038 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1039 struct osl_object query = {.data = &table_mask,
1040 .size = sizeof(table_mask)};
1041
1042 ret = make_database_dir();
1043 if (ret < 0)
1044 return ret;
1045 if (cc->argc != 1) {
1046 table_mask = 0;
1047 for (i = 1; i < cc->argc; i++) {
1048 for (j = 0; j < NUM_AFS_TABLES; j++) {
1049 struct afs_table *t = &afs_tables[j];
1050
1051 if (strcmp(cc->argv[i], t->name))
1052 continue;
1053 table_mask |= (1 << j);
1054 break;
1055 }
1056 if (j == NUM_AFS_TABLES)
1057 return -E_BAD_TABLE_NAME;
1058 }
1059 }
1060 return send_callback_request(create_tables_callback, &query,
1061 afs_cb_result_handler, cc);
1062 }
1063
1064 /**
1065 * Flags for the check command.
1066 *
1067 * \sa com_check().
1068 */
1069 enum com_check_flags {
1070 /** Check the audio file table. */
1071 CHECK_AFT = 1,
1072 /** Check the mood table. */
1073 CHECK_MOODS = 2,
1074 /** Check the playlist table. */
1075 CHECK_PLAYLISTS = 4
1076 };
1077
1078 int com_check(struct command_context *cc)
1079 {
1080 unsigned flags = 0;
1081 int i, ret;
1082
1083 for (i = 1; i < cc->argc; i++) {
1084 const char *arg = cc->argv[i];
1085 if (arg[0] != '-')
1086 break;
1087 if (!strcmp(arg, "--")) {
1088 i++;
1089 break;
1090 }
1091 if (!strcmp(arg, "-a")) {
1092 flags |= CHECK_AFT;
1093 continue;
1094 }
1095 if (!strcmp(arg, "-p")) {
1096 flags |= CHECK_PLAYLISTS;
1097 continue;
1098 }
1099 if (!strcmp(arg, "-m")) {
1100 flags |= CHECK_MOODS;
1101 continue;
1102 }
1103 return -E_AFS_SYNTAX;
1104 }
1105 if (i < cc->argc)
1106 return -E_AFS_SYNTAX;
1107 if (!flags)
1108 flags = ~0U;
1109 if (flags & CHECK_AFT) {
1110 ret = send_callback_request(aft_check_callback, NULL,
1111 afs_cb_result_handler, cc);
1112 if (ret < 0)
1113 return ret;
1114 }
1115 if (flags & CHECK_PLAYLISTS) {
1116 ret = send_callback_request(playlist_check_callback,
1117 NULL, afs_cb_result_handler, cc);
1118 if (ret < 0)
1119 return ret;
1120 }
1121 if (flags & CHECK_MOODS) {
1122 ret = send_callback_request(mood_check_callback, NULL,
1123 afs_cb_result_handler, cc);
1124 if (ret < 0)
1125 return ret;
1126 }
1127 return 1;
1128 }
1129
1130 /**
1131 * The afs event dispatcher.
1132 *
1133 * \param event Type of the event.
1134 * \param pb May be \p NULL.
1135 * \param data Type depends on \a event.
1136 *
1137 * This function calls the table handlers of all tables and passes \a pb and \a
1138 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1139 */
1140 void afs_event(enum afs_events event, struct para_buffer *pb,
1141 void *data)
1142 {
1143 int i, ret;
1144
1145 for (i = 0; i < NUM_AFS_TABLES; i++) {
1146 struct afs_table *t = &afs_tables[i];
1147 if (!t->event_handler)
1148 continue;
1149 ret = t->event_handler(event, pb, data);
1150 if (ret < 0)
1151 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1152 event, para_strerror(-ret));
1153 }
1154 }
1155
1156 /**
1157 * Dummy event handler for the images table.
1158 *
1159 * \param event Unused.
1160 * \param pb Unused.
1161 * \param data Unused.
1162 *
1163 * \return The images table does not honor events, so this handler always
1164 * returns success.
1165 */
1166 __a_const int images_event_handler(__a_unused enum afs_events event,
1167 __a_unused struct para_buffer *pb, __a_unused void *data)
1168 {
1169 return 1;
1170 }
1171
1172 /**
1173 * Dummy event handler for the lyrics table.
1174 *
1175 * \param event Unused.
1176 * \param pb Unused.
1177 * \param data Unused.
1178 *
1179 * \return The lyrics table does not honor events, so this handler always
1180 * returns success.
1181 */
1182 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1183 __a_unused struct para_buffer *pb, __a_unused void *data)
1184 {
1185 return 1;
1186 }