Introduce afs_max_size_handler_data and afs_max_size_handler().
[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 = &(struct afs_max_size_handler_data) {
550 .fd = fd,
551 },
552 .max_size_handler = afs_max_size_handler,
553 };
554 char *arg = query->data;
555 int num_admissible, ret, ret2;
556
557 ret = clear_score_table();
558 if (ret < 0) {
559 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
560 goto out;
561 }
562 if (current_play_mode == PLAY_MODE_MOOD)
563 close_current_mood();
564 else
565 playlist_close();
566 ret = activate_mood_or_playlist(arg, &num_admissible);
567 if (ret < 0) {
568 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
569 para_strerror(-ret), current_mop?
570 current_mop : "dummy");
571 ret = activate_mood_or_playlist(current_mop, &num_admissible);
572 if (ret < 0) {
573 if (ret2 >= 0)
574 ret2 = para_printf(&pb, "failed, switching to dummy\n");
575 activate_mood_or_playlist(NULL, &num_admissible);
576 }
577 } else
578 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
579 current_mop : "dummy mood", num_admissible);
580 out:
581 if (ret2 >= 0 && pb.offset)
582 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
583 free(pb.buf);
584 }
585
586 /**
587 * Result handler for sending data to the para_client process.
588 *
589 * \param result The data to be sent.
590 * \param private Pointer to the context.
591 *
592 * \return The return value of the underlying call to sc_send_bin_buffer().
593 *
594 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
595 */
596 int sc_send_result(struct osl_object *result, void *private)
597 {
598 struct command_context *cc = private;
599 int ret;
600
601 if (!result->size)
602 return 1;
603 ret = sc_send_bin_buffer(&cc->scc, result->data, result->size);
604 if (ret < 0 || ret == result->size)
605 return ret;
606 return -E_SHORT_WRITE;
607 }
608
609 int com_select(struct command_context *cc)
610 {
611 struct osl_object query;
612
613 if (cc->argc != 2)
614 return -E_AFS_SYNTAX;
615 query.data = cc->argv[1];
616 query.size = strlen(cc->argv[1]) + 1;
617 return send_callback_request(com_select_callback, &query,
618 &sc_send_result, cc);
619 }
620
621 static void init_admissible_files(char *arg)
622 {
623 if (activate_mood_or_playlist(arg, NULL) < 0)
624 activate_mood_or_playlist(NULL, NULL); /* always successful */
625 }
626
627 static int setup_command_socket_or_die(void)
628 {
629 int ret, socket_fd;
630 char *socket_name = conf.afs_socket_arg;
631 struct sockaddr_un unix_addr;
632
633 unlink(socket_name);
634 ret = create_local_socket(socket_name, &unix_addr,
635 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
636 if (ret < 0) {
637 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
638 exit(EXIT_FAILURE);
639 }
640 socket_fd = ret;
641 if (listen(socket_fd , 5) < 0) {
642 PARA_EMERG_LOG("can not listen on socket\n");
643 exit(EXIT_FAILURE);
644 }
645 ret = mark_fd_nonblocking(socket_fd);
646 if (ret < 0) {
647 close(socket_fd);
648 return ret;
649 }
650 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
651 socket_fd);
652 return socket_fd;
653 }
654
655 static void close_afs_tables(void)
656 {
657 int i;
658 PARA_NOTICE_LOG("closing afs_tables\n");
659 for (i = 0; i < NUM_AFS_TABLES; i++)
660 afs_tables[i].close();
661 }
662
663 static char *database_dir;
664
665 static void get_database_dir(void)
666 {
667 if (!database_dir) {
668 if (conf.afs_database_dir_given)
669 database_dir = para_strdup(conf.afs_database_dir_arg);
670 else {
671 char *home = para_homedir();
672 database_dir = make_message(
673 "%s/.paraslash/afs_database-0.4", home);
674 free(home);
675 }
676 }
677 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
678 }
679
680 static int make_database_dir(void)
681 {
682 int ret;
683
684 get_database_dir();
685 ret = para_mkdir(database_dir, 0777);
686 if (ret >= 0 || is_errno(-ret, EEXIST))
687 return 1;
688 return ret;
689 }
690
691 static int open_afs_tables(void)
692 {
693 int i, ret;
694
695 get_database_dir();
696 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
697 database_dir);
698 for (i = 0; i < NUM_AFS_TABLES; i++) {
699 ret = afs_tables[i].open(database_dir);
700 if (ret >= 0)
701 continue;
702 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
703 para_strerror(-ret));
704 break;
705 }
706 if (ret >= 0)
707 return ret;
708 while (i)
709 afs_tables[--i].close();
710 return ret;
711 }
712
713 static void signal_pre_select(struct sched *s, struct task *t)
714 {
715 struct signal_task *st = container_of(t, struct signal_task, task);
716 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
717 }
718
719 static void afs_signal_post_select(struct sched *s, struct task *t)
720 {
721 int signum;
722
723 if (getppid() == 1) {
724 PARA_EMERG_LOG("para_server died\n");
725 goto shutdown;
726 }
727 signum = para_next_signal(&s->rfds);
728 if (signum == 0)
729 return;
730 if (signum == SIGHUP) {
731 close_afs_tables();
732 parse_config_or_die(1);
733 t->error = open_afs_tables();
734 if (t->error < 0)
735 return;
736 init_admissible_files(current_mop);
737 return;
738 }
739 PARA_EMERG_LOG("terminating on signal %d\n", signum);
740 shutdown:
741 sched_shutdown(s);
742 t->error = -E_AFS_SIGNAL;
743 }
744
745 static void register_signal_task(struct sched *s)
746 {
747 struct signal_task *st = &signal_task_struct;
748
749 para_sigaction(SIGPIPE, SIG_IGN);
750 st->fd = para_signal_init();
751 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
752 para_install_sighandler(SIGINT);
753 para_install_sighandler(SIGTERM);
754 para_install_sighandler(SIGHUP);
755
756 st->task.pre_select = signal_pre_select;
757 st->task.post_select = afs_signal_post_select;
758 sprintf(st->task.status, "signal task");
759 register_task(s, &st->task);
760 }
761
762 static struct list_head afs_client_list;
763
764 /** Describes on connected afs client. */
765 struct afs_client {
766 /** Position in the afs client list. */
767 struct list_head node;
768 /** The socket file descriptor for this client. */
769 int fd;
770 /** The time the client connected. */
771 struct timeval connect_time;
772 };
773
774 static void command_pre_select(struct sched *s, struct task *t)
775 {
776 struct command_task *ct = container_of(t, struct command_task, task);
777 struct afs_client *client;
778
779 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
780 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
781 list_for_each_entry(client, &afs_client_list, node)
782 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
783 }
784
785 /**
786 * Send data as shared memory to a file descriptor.
787 *
788 * \param buf The buffer holding the data to be sent.
789 * \param size The size of \a buf.
790 * \param fd_ptr A pointer to the file descriptor.
791 *
792 * This function creates a shared memory area large enough to hold
793 * the content given by \a buf and \a size and sends the identifier
794 * of this area to the file descriptor given by \a fd_ptr.
795 *
796 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
797 * and positive on success.
798 */
799 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
800 {
801 int ret, shmid, fd = *(int *)fd_ptr;
802 void *shm;
803 struct callback_result *cr;
804
805 if (!buf || !size)
806 return 0;
807 ret = shm_new(size + sizeof(struct callback_result));
808 if (ret < 0)
809 return ret;
810 shmid = ret;
811 ret = shm_attach(shmid, ATTACH_RW, &shm);
812 if (ret < 0)
813 goto err;
814 cr = shm;
815 cr->result_size = size;
816 memcpy(shm + sizeof(*cr), buf, size);
817 ret = shm_detach(shm);
818 if (ret < 0)
819 goto err;
820 ret = write_all(fd, (char *)&shmid, sizeof(int));
821 if (ret >= 0)
822 return ret;
823 err:
824 if (shm_destroy(shmid) < 0)
825 PARA_ERROR_LOG("destroy result failed\n");
826 return ret;
827 }
828
829 /*
830 * On errors, negative value is written to fd.
831 * On success: If query produced a result, the result_shmid is written to fd.
832 * Otherwise, zero is written.
833 */
834 static int call_callback(int fd, int query_shmid)
835 {
836 void *query_shm;
837 struct callback_query *cq;
838 struct osl_object query;
839 int ret;
840
841 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
842 if (ret < 0)
843 return ret;
844 cq = query_shm;
845 query.data = (char *)query_shm + sizeof(*cq);
846 query.size = cq->query_size;
847 cq->handler(fd, &query);
848 return shm_detach(query_shm);
849 }
850
851 static int execute_server_command(fd_set *rfds)
852 {
853 char buf[8];
854 size_t n;
855 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
856
857 if (ret < 0 || n == 0)
858 return ret;
859 buf[n] = '\0';
860 if (strcmp(buf, "new"))
861 return -E_BAD_CMD;
862 return open_next_audio_file();
863 }
864
865 /* returns 0 if no data available, 1 else */
866 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
867 {
868 uint32_t cookie;
869 int query_shmid;
870 char buf[sizeof(cookie) + sizeof(query_shmid)];
871 size_t n;
872 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
873
874 if (ret < 0)
875 goto err;
876 if (n == 0)
877 return 0;
878 if (n != sizeof(buf)) {
879 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
880 ret, (long unsigned) sizeof(buf));
881 return 1;
882 }
883 cookie = *(uint32_t *)buf;
884 if (cookie != expected_cookie) {
885 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
886 (unsigned)cookie, (unsigned)expected_cookie);
887 return 1;
888 }
889 query_shmid = *(int *)(buf + sizeof(cookie));
890 if (query_shmid < 0) {
891 PARA_WARNING_LOG("received invalid query shmid %d)\n",
892 query_shmid);
893 return 1;
894 }
895 ret = call_callback(fd, query_shmid);
896 if (ret >= 0)
897 return 1;
898 err:
899 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
900 return 1;
901 }
902
903 /** Shutdown connection if query has not arrived until this many seconds. */
904 #define AFS_CLIENT_TIMEOUT 3
905
906 static void command_post_select(struct sched *s, struct task *t)
907 {
908 struct command_task *ct = container_of(t, struct command_task, task);
909 struct sockaddr_un unix_addr;
910 struct afs_client *client, *tmp;
911 int fd, ret;
912
913 ret = execute_server_command(&s->rfds);
914 if (ret < 0) {
915 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
916 sched_shutdown(s);
917 return;
918 }
919 /* Check the list of connected clients. */
920 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
921 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
922 if (ret == 0) { /* prevent bogus connection flooding */
923 struct timeval diff;
924 tv_diff(now, &client->connect_time, &diff);
925 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
926 continue;
927 PARA_WARNING_LOG("connection timeout\n");
928 }
929 close(client->fd);
930 list_del(&client->node);
931 free(client);
932 }
933 /* Accept connections on the local socket. */
934 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
935 if (ret < 0)
936 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
937 if (ret <= 0)
938 return;
939 ret = mark_fd_nonblocking(fd);
940 if (ret < 0) {
941 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
942 close(fd);
943 return;
944 }
945 client = para_malloc(sizeof(*client));
946 client->fd = fd;
947 client->connect_time = *now;
948 para_list_add(&client->node, &afs_client_list);
949 }
950
951 static void register_command_task(uint32_t cookie, struct sched *s)
952 {
953 struct command_task *ct = &command_task_struct;
954 ct->fd = setup_command_socket_or_die();
955 ct->cookie = cookie;
956
957 ct->task.pre_select = command_pre_select;
958 ct->task.post_select = command_post_select;
959 sprintf(ct->task.status, "afs command task");
960 register_task(s, &ct->task);
961 }
962
963 /**
964 * Initialize the audio file selector process.
965 *
966 * \param cookie The value used for "authentication".
967 * \param socket_fd File descriptor used for communication with the server.
968 */
969 __noreturn void afs_init(uint32_t cookie, int socket_fd)
970 {
971 static struct sched s;
972 int i, ret;
973
974 register_signal_task(&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 out_close:
993 close_afs_tables();
994 out:
995 if (ret < 0)
996 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
997 exit(EXIT_FAILURE);
998 }
999
1000 static void create_tables_callback(int fd, const struct osl_object *query)
1001 {
1002 uint32_t table_mask = *(uint32_t *)query->data;
1003 int i, ret;
1004 struct para_buffer pb = {.buf = NULL};
1005
1006 close_afs_tables();
1007 for (i = 0; i < NUM_AFS_TABLES; i++) {
1008 struct afs_table *t = &afs_tables[i];
1009
1010 if (!(table_mask & (1 << i)))
1011 continue;
1012 if (!t->create)
1013 continue;
1014 ret = t->create(database_dir);
1015 if (ret < 0)
1016 goto out;
1017 para_printf(&pb, "successfully created %s table\n", t->name);
1018 }
1019 ret = open_afs_tables();
1020 out:
1021 if (ret < 0)
1022 para_printf(&pb, "%s\n", para_strerror(-ret));
1023 if (pb.buf)
1024 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1025 free(pb.buf);
1026 }
1027
1028 int com_init(struct command_context *cc)
1029 {
1030 int i, j, ret;
1031 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1032 struct osl_object query = {.data = &table_mask,
1033 .size = sizeof(table_mask)};
1034
1035 ret = make_database_dir();
1036 if (ret < 0)
1037 return ret;
1038 if (cc->argc != 1) {
1039 table_mask = 0;
1040 for (i = 1; i < cc->argc; i++) {
1041 for (j = 0; j < NUM_AFS_TABLES; j++) {
1042 struct afs_table *t = &afs_tables[j];
1043
1044 if (strcmp(cc->argv[i], t->name))
1045 continue;
1046 table_mask |= (1 << j);
1047 break;
1048 }
1049 if (j == NUM_AFS_TABLES)
1050 return -E_BAD_TABLE_NAME;
1051 }
1052 }
1053 ret = send_callback_request(create_tables_callback, &query,
1054 sc_send_result, cc);
1055 if (ret < 0)
1056 /* ignore return value */
1057 sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(-ret));
1058 return ret;
1059 }
1060
1061 /**
1062 * Flags for the check command.
1063 *
1064 * \sa com_check().
1065 */
1066 enum com_check_flags {
1067 /** Check the audio file table. */
1068 CHECK_AFT = 1,
1069 /** Check the mood table. */
1070 CHECK_MOODS = 2,
1071 /** Check the playlist table. */
1072 CHECK_PLAYLISTS = 4
1073 };
1074
1075 int com_check(struct command_context *cc)
1076 {
1077 unsigned flags = 0;
1078 int i, ret;
1079
1080 for (i = 1; i < cc->argc; i++) {
1081 const char *arg = cc->argv[i];
1082 if (arg[0] != '-')
1083 break;
1084 if (!strcmp(arg, "--")) {
1085 i++;
1086 break;
1087 }
1088 if (!strcmp(arg, "-a")) {
1089 flags |= CHECK_AFT;
1090 continue;
1091 }
1092 if (!strcmp(arg, "-p")) {
1093 flags |= CHECK_PLAYLISTS;
1094 continue;
1095 }
1096 if (!strcmp(arg, "-m")) {
1097 flags |= CHECK_MOODS;
1098 continue;
1099 }
1100 return -E_AFS_SYNTAX;
1101 }
1102 if (i < cc->argc)
1103 return -E_AFS_SYNTAX;
1104 if (!flags)
1105 flags = ~0U;
1106 if (flags & CHECK_AFT) {
1107 ret = send_callback_request(aft_check_callback, NULL,
1108 sc_send_result, cc);
1109 if (ret < 0)
1110 return ret;
1111 }
1112 if (flags & CHECK_PLAYLISTS) {
1113 ret = send_callback_request(playlist_check_callback,
1114 NULL, sc_send_result, cc);
1115 if (ret < 0)
1116 return ret;
1117 }
1118 if (flags & CHECK_MOODS) {
1119 ret = send_callback_request(mood_check_callback, NULL,
1120 sc_send_result, cc);
1121 if (ret < 0)
1122 return ret;
1123 }
1124 return 1;
1125 }
1126
1127 /**
1128 * The afs event dispatcher.
1129 *
1130 * \param event Type of the event.
1131 * \param pb May be \p NULL.
1132 * \param data Type depends on \a event.
1133 *
1134 * This function calls the table handlers of all tables and passes \a pb and \a
1135 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1136 */
1137 void afs_event(enum afs_events event, struct para_buffer *pb,
1138 void *data)
1139 {
1140 int i, ret;
1141
1142 for (i = 0; i < NUM_AFS_TABLES; i++) {
1143 struct afs_table *t = &afs_tables[i];
1144 if (!t->event_handler)
1145 continue;
1146 ret = t->event_handler(event, pb, data);
1147 if (ret < 0)
1148 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1149 event, para_strerror(-ret));
1150 }
1151 }
1152
1153 /**
1154 * Dummy event handler for the images table.
1155 *
1156 * \param event Unused.
1157 * \param pb Unused.
1158 * \param data Unused.
1159 *
1160 * \return The images table does not honor events, so this handler always
1161 * returns success.
1162 */
1163 __a_const int images_event_handler(__a_unused enum afs_events event,
1164 __a_unused struct para_buffer *pb, __a_unused void *data)
1165 {
1166 return 1;
1167 }
1168
1169 /**
1170 * Dummy event handler for the lyrics table.
1171 *
1172 * \param event Unused.
1173 * \param pb Unused.
1174 * \param data Unused.
1175 *
1176 * \return The lyrics table does not honor events, so this handler always
1177 * returns success.
1178 */
1179 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1180 __a_unused struct para_buffer *pb, __a_unused void *data)
1181 {
1182 return 1;
1183 }