Merge branch 't/uptime_cleanup'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2011 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
30 /** The osl tables used by afs. \sa blob.c. */
31 enum afs_table_num {
32 /** Contains audio file information. See aft.c. */
33 TBLNUM_AUDIO_FILES,
34 /** The table for the paraslash attributes. See attribute.c. */
35 TBLNUM_ATTRIBUTES,
36 /**
37 * Paraslash's scoring system is based on Gaussian normal
38 * distributions, and the relevant data is stored in the rbtrees of an
39 * osl table containing only volatile columns. See score.c for
40 * details.
41 */
42 TBLNUM_SCORES,
43 /**
44 * A standard blob table containing the mood definitions. For details
45 * see mood.c.
46 */
47 TBLNUM_MOODS,
48 /** A blob table containing lyrics on a per-song basis. */
49 TBLNUM_LYRICS,
50 /** Another blob table for images (for example album cover art). */
51 TBLNUM_IMAGES,
52 /** Yet another blob table for storing standard playlists. */
53 TBLNUM_PLAYLIST,
54 /** How many tables are in use? */
55 NUM_AFS_TABLES
56 };
57
58 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
59 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
60 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
61 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
62 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
63 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
64 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
65 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
66 };
67
68 struct command_task {
69 /** The file descriptor for the local socket. */
70 int fd;
71 /**
72 * Value sent by the command handlers to identify themselves as
73 * children of the running para_server.
74 */
75 uint32_t cookie;
76 /** The associated task structure. */
77 struct task task;
78 };
79
80 extern int mmd_mutex;
81 extern struct misc_meta_data *mmd;
82
83 static int server_socket;
84 static struct command_task command_task_struct;
85 static struct signal_task signal_task_struct;
86
87 static enum play_mode current_play_mode;
88 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
89
90 /**
91 * A random number used to "authenticate" the connection.
92 *
93 * para_server picks this number by random before forking the afs process. The
94 * command handlers write this number together with the id of the shared memory
95 * area containing the query. This way, a malicious local user has to know this
96 * number to be able to cause the afs process to crash by sending fake queries.
97 */
98 extern uint32_t afs_socket_cookie;
99
100 /**
101 * Struct to let command handlers execute a callback in afs context.
102 *
103 * Commands that need to change the state of afs can't change the relevant data
104 * structures directly because commands are executed in a child process, i.e.
105 * they get their own virtual address space.
106 *
107 * This structure is used by \p send_callback_request() (executed from handler
108 * context) in order to let the afs process call the specified function. An
109 * instance of that structure is written to a shared memory area together with
110 * the arguments to the callback function. The identifier of the shared memory
111 * area is written to the command socket.
112 *
113 * The afs process accepts connections on the command socket and reads the
114 * shared memory id, attaches the corresponing area, calls the given handler to
115 * perform the desired action and to optionally compute a result.
116 *
117 * The result and a \p callback_result structure is then written to another
118 * shared memory area. The identifier for that area is written to the handler's
119 * command socket, so that the handler process can read the id, attach the
120 * shared memory area and use the result.
121 *
122 * \sa struct callback_result.
123 */
124 struct callback_query {
125 /** The function to be called. */
126 callback_function *handler;
127 /** The number of bytes of the query */
128 size_t query_size;
129 };
130
131 /**
132 * Structure embedded in the result of a callback.
133 *
134 * If the callback produced a result, an instance of that structure is embeeded
135 * into the shared memory area holding the result, mainly to let the command
136 * handler know the size of the result.
137 *
138 * \sa struct callback_query.
139 */
140 struct callback_result {
141 /** The number of bytes of the result. */
142 size_t result_size;
143 };
144
145 static int dispatch_result(int result_shmid, callback_result_handler *handler,
146 void *private_result_data)
147 {
148 struct osl_object result;
149 void *result_shm;
150 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
151 struct callback_result *cr = result_shm;
152
153 if (ret < 0) {
154 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
155 return ret;
156 }
157 result.size = cr->result_size;
158 result.data = result_shm + sizeof(*cr);
159 if (result.size) {
160 assert(handler);
161 ret = handler(&result, private_result_data);
162 if (ret < 0)
163 PARA_NOTICE_LOG("result handler error: %s\n",
164 para_strerror(-ret));
165 }
166 ret2 = shm_detach(result_shm);
167 if (ret2 < 0) {
168 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
169 if (ret >= 0)
170 ret = ret2;
171 }
172 return ret;
173 }
174
175 /**
176 * Ask the afs process to call a given function.
177 *
178 * \param f The function to be called.
179 * \param query Pointer to arbitrary data for the callback.
180 * \param result_handler Called for each shm area sent by the callback.
181 * \param private_result_data Passed verbatim to \a result_handler.
182 *
183 * This function creates a socket for communication with the afs process and a
184 * shared memory area (sma) to which the buffer pointed to by \a query is
185 * copied. It then notifies the afs process that the callback function \a f
186 * should be executed by sending the shared memory identifier (shmid) to the
187 * socket.
188
189 * If the callback produces a result, it sends any number of shared memory
190 * identifiers back via the socket. For each such identifier received, \a
191 * result_handler is called. The contents of the sma identified by the received
192 * shmid are passed to that function as an osl object. The private_result_data
193 * pointer is passed as the second argument to \a result_handler.
194 *
195 * \return Standard.
196 *
197 * \sa send_option_arg_callback_request(), send_standard_callback_request().
198 */
199 int send_callback_request(callback_function *f, struct osl_object *query,
200 callback_result_handler *result_handler,
201 void *private_result_data)
202 {
203 struct callback_query *cq;
204 int ret, fd = -1, query_shmid, result_shmid;
205 void *query_shm;
206 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
207 size_t query_shm_size = sizeof(*cq);
208 int dispatch_error = 0;
209
210 if (query)
211 query_shm_size += query->size;
212 ret = shm_new(query_shm_size);
213 if (ret < 0)
214 return ret;
215 query_shmid = ret;
216 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
217 if (ret < 0)
218 goto out;
219 cq = query_shm;
220 cq->handler = f;
221 cq->query_size = query_shm_size - sizeof(*cq);
222
223 if (query)
224 memcpy(query_shm + sizeof(*cq), query->data, query->size);
225 ret = shm_detach(query_shm);
226 if (ret < 0)
227 goto out;
228
229 *(uint32_t *) buf = afs_socket_cookie;
230 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
231
232 ret = connect_local_socket(conf.afs_socket_arg);
233 if (ret < 0)
234 goto out;
235 fd = ret;
236 ret = send_bin_buffer(fd, buf, sizeof(buf));
237 if (ret < 0)
238 goto out;
239 /*
240 * Read all shmids from afs.
241 *
242 * Even if the dispatcher returns an error we _must_ continue to read
243 * shmids from fd so that we can destroy all shared memory areas that
244 * have been created for us by the afs process.
245 */
246 for (;;) {
247 ret = recv_bin_buffer(fd, buf, sizeof(int));
248 if (ret <= 0)
249 goto out;
250 assert(ret == sizeof(int));
251 ret = *(int *) buf;
252 assert(ret > 0);
253 result_shmid = ret;
254 if (!dispatch_error) {
255 ret = dispatch_result(result_shmid, result_handler,
256 private_result_data);
257 if (ret < 0)
258 dispatch_error = 1;
259 }
260 ret = shm_destroy(result_shmid);
261 if (ret < 0)
262 PARA_CRIT_LOG("destroy result failed: %s\n",
263 para_strerror(-ret));
264 }
265 out:
266 if (shm_destroy(query_shmid) < 0)
267 PARA_CRIT_LOG("shm destroy error\n");
268 if (fd >= 0)
269 close(fd);
270 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
271 return ret;
272 }
273
274 /**
275 * Send a callback request passing an options structure and an argument vector.
276 *
277 * \param options pointer to an arbitrary data structure.
278 * \param argc Argument count.
279 * \param argv Standard argument vector.
280 * \param f The callback function.
281 * \param result_handler See \ref send_callback_request.
282 * \param private_result_data See \ref send_callback_request.
283 *
284 * Some commands have a couple of options that are parsed in child context for
285 * syntactic correctness and are stored in a special options structure for that
286 * command. This function allows to pass such a structure together with a list
287 * of further arguments (often a list of audio files) to the parent process.
288 *
289 * \sa send_standard_callback_request(), send_callback_request().
290 */
291 int send_option_arg_callback_request(struct osl_object *options,
292 int argc, char * const * const argv, callback_function *f,
293 callback_result_handler *result_handler,
294 void *private_result_data)
295 {
296 char *p;
297 int i, ret;
298 struct osl_object query = {.size = options? options->size : 0};
299
300 for (i = 0; i < argc; i++)
301 query.size += strlen(argv[i]) + 1;
302 query.data = para_malloc(query.size);
303 p = query.data;
304 if (options) {
305 memcpy(query.data, options->data, options->size);
306 p += options->size;
307 }
308 for (i = 0; i < argc; i++) {
309 strcpy(p, argv[i]); /* OK */
310 p += strlen(argv[i]) + 1;
311 }
312 ret = send_callback_request(f, &query, result_handler,
313 private_result_data);
314 free(query.data);
315 return ret;
316 }
317
318 /**
319 * Send a callback request with an argument vector only.
320 *
321 * \param argc The same meaning as in send_option_arg_callback_request().
322 * \param argv The same meaning as in send_option_arg_callback_request().
323 * \param f The same meaning as in send_option_arg_callback_request().
324 * \param result_handler See \ref send_callback_request.
325 * \param private_result_data See \ref send_callback_request.
326 *
327 * This is similar to send_option_arg_callback_request(), but no options buffer
328 * is passed to the parent process.
329 *
330 * \return The return value of the underlying call to
331 * send_option_arg_callback_request().
332 */
333 int send_standard_callback_request(int argc, char * const * const argv,
334 callback_function *f, callback_result_handler *result_handler,
335 void *private_result_data)
336 {
337 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
338 private_result_data);
339 }
340
341 static int action_if_pattern_matches(struct osl_row *row, void *data)
342 {
343 struct pattern_match_data *pmd = data;
344 struct osl_object name_obj;
345 const char *p, *name;
346 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
347 const char *pattern_txt = (const char *)pmd->patterns.data;
348
349 if (ret < 0)
350 return ret;
351 name = (char *)name_obj.data;
352 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
353 return 1;
354 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
355 return pmd->action(pmd->table, row, name, pmd->data);
356 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
357 p += strlen(p) + 1) {
358 ret = fnmatch(p, name, pmd->fnmatch_flags);
359 if (ret == FNM_NOMATCH)
360 continue;
361 if (ret)
362 return -E_FNMATCH;
363 return pmd->action(pmd->table, row, name, pmd->data);
364 }
365 return 1;
366 }
367
368 /**
369 * Execute the given function for each matching row.
370 *
371 * \param pmd Describes what to match and how.
372 *
373 * \return Standard.
374 */
375 int for_each_matching_row(struct pattern_match_data *pmd)
376 {
377 if (pmd->pm_flags & PM_REVERSE_LOOP)
378 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
379 action_if_pattern_matches));
380 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
381 action_if_pattern_matches));
382 }
383
384 /**
385 * Compare two osl objects of string type.
386 *
387 * \param obj1 Pointer to the first object.
388 * \param obj2 Pointer to the second object.
389 *
390 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
391 * are taken into account.
392 *
393 * \return It returns an integer less than, equal to, or greater than zero if
394 * \a obj1 is found, respectively, to be less than, to match, or be greater than
395 * obj2.
396 *
397 * \sa strcmp(3), strncmp(3), osl_compare_func.
398 */
399 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
400 {
401 const char *str1 = (const char *)obj1->data;
402 const char *str2 = (const char *)obj2->data;
403 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
404 }
405
406 static int pass_afd(int fd, char *buf, size_t size)
407 {
408 struct msghdr msg = {.msg_iov = NULL};
409 struct cmsghdr *cmsg;
410 char control[255];
411 int ret;
412 struct iovec iov;
413
414 iov.iov_base = buf;
415 iov.iov_len = size;
416
417 msg.msg_iov = &iov;
418 msg.msg_iovlen = 1;
419
420 msg.msg_control = control;
421 msg.msg_controllen = sizeof(control);
422
423 cmsg = CMSG_FIRSTHDR(&msg);
424 cmsg->cmsg_level = SOL_SOCKET;
425 cmsg->cmsg_type = SCM_RIGHTS;
426 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
427 *(int *)CMSG_DATA(cmsg) = fd;
428
429 /* Sum of the length of all control messages in the buffer */
430 msg.msg_controllen = cmsg->cmsg_len;
431 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
432 ret = sendmsg(server_socket, &msg, 0);
433 if (ret < 0) {
434 ret = -ERRNO_TO_PARA_ERROR(errno);
435 return ret;
436 }
437 return 1;
438 }
439
440 /**
441 * Open the audio file with highest score.
442 *
443 * This stores all information for streaming the "best" audio file in a shared
444 * memory area. The id of that area and an open file descriptor for the next
445 * audio file are passed to the server process.
446 *
447 * \return Standard.
448 *
449 * \sa open_and_update_audio_file().
450 */
451 static int open_next_audio_file(void)
452 {
453 struct osl_row *aft_row;
454 struct audio_file_data afd;
455 int ret, shmid;
456 char buf[8];
457 long score;
458 again:
459 PARA_NOTICE_LOG("getting next audio file\n");
460 ret = score_get_best(&aft_row, &score);
461 if (ret < 0) {
462 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
463 goto no_admissible_files;
464 }
465 ret = open_and_update_audio_file(aft_row, score, &afd);
466 if (ret < 0) {
467 ret = score_delete(aft_row);
468 if (ret < 0) {
469 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
470 goto no_admissible_files;
471 }
472 goto again;
473 }
474 shmid = ret;
475 if (!write_ok(server_socket)) {
476 ret = -E_AFS_SOCKET;
477 goto destroy;
478 }
479 *(uint32_t *)buf = NEXT_AUDIO_FILE;
480 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
481 ret = pass_afd(afd.fd, buf, 8);
482 close(afd.fd);
483 if (ret >= 0)
484 return ret;
485 destroy:
486 shm_destroy(shmid);
487 return ret;
488 no_admissible_files:
489 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
490 *(uint32_t *)(buf + 4) = (uint32_t)0;
491 return send_bin_buffer(server_socket, buf, 8);
492 }
493
494 /* Never fails if arg == NULL */
495 static int activate_mood_or_playlist(char *arg, int *num_admissible)
496 {
497 enum play_mode mode;
498 int ret;
499
500 if (!arg) {
501 ret = change_current_mood(NULL); /* always successful */
502 mode = PLAY_MODE_MOOD;
503 } else {
504 if (!strncmp(arg, "p/", 2)) {
505 ret = playlist_open(arg + 2);
506 mode = PLAY_MODE_PLAYLIST;
507 } else if (!strncmp(arg, "m/", 2)) {
508 ret = change_current_mood(arg + 2);
509 mode = PLAY_MODE_MOOD;
510 } else
511 return -E_AFS_SYNTAX;
512 if (ret < 0)
513 return ret;
514 }
515 if (num_admissible)
516 *num_admissible = ret;
517 current_play_mode = mode;
518 if (arg != current_mop) {
519 free(current_mop);
520 if (arg) {
521 current_mop = para_strdup(arg);
522 mutex_lock(mmd_mutex);
523 strncpy(mmd->afs_mode_string, arg,
524 sizeof(mmd->afs_mode_string));
525 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
526 mutex_unlock(mmd_mutex);
527 } else {
528 mutex_lock(mmd_mutex);
529 strcpy(mmd->afs_mode_string, "dummy");
530 mutex_unlock(mmd_mutex);
531 current_mop = NULL;
532 }
533 }
534 return 1;
535 }
536
537 static void com_select_callback(int fd, const struct osl_object *query)
538 {
539 struct para_buffer pb = {
540 .max_size = shm_get_shmmax(),
541 .private_data = &fd,
542 .max_size_handler = pass_buffer_as_shm
543 };
544 char *arg = query->data;
545 int num_admissible, ret, ret2;
546
547 ret = clear_score_table();
548 if (ret < 0) {
549 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
550 goto out;
551 }
552 if (current_play_mode == PLAY_MODE_MOOD)
553 close_current_mood();
554 else
555 playlist_close();
556 ret = activate_mood_or_playlist(arg, &num_admissible);
557 if (ret < 0) {
558 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
559 para_strerror(-ret), current_mop?
560 current_mop : "dummy");
561 ret = activate_mood_or_playlist(current_mop, &num_admissible);
562 if (ret < 0) {
563 if (ret2 >= 0)
564 ret2 = para_printf(&pb, "failed, switching to dummy\n");
565 activate_mood_or_playlist(NULL, &num_admissible);
566 }
567 } else
568 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
569 current_mop : "dummy mood", num_admissible);
570 out:
571 if (ret2 >= 0 && pb.offset)
572 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
573 free(pb.buf);
574 }
575
576 /**
577 * Result handler for sending data to the para_client process.
578 *
579 * \param result The data to be sent.
580 * \param private Pointer to the context.
581 *
582 * \return The return value of the underlying call to sc_send_bin_buffer().
583 *
584 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
585 */
586 int sc_send_result(struct osl_object *result, void *private)
587 {
588 struct stream_cipher_context *scc = private;
589
590 if (!result->size)
591 return 1;
592 return sc_send_bin_buffer(scc, result->data, result->size);
593 }
594
595 int com_select(struct stream_cipher_context *scc, int argc, char * const * const argv)
596 {
597 struct osl_object query;
598
599 if (argc != 2)
600 return -E_AFS_SYNTAX;
601 query.data = argv[1];
602 query.size = strlen(argv[1]) + 1;
603 return send_callback_request(com_select_callback, &query,
604 &sc_send_result, scc);
605 }
606
607 static void init_admissible_files(char *arg)
608 {
609 if (activate_mood_or_playlist(arg, NULL) < 0)
610 activate_mood_or_playlist(NULL, NULL); /* always successful */
611 }
612
613 static int setup_command_socket_or_die(void)
614 {
615 int ret, socket_fd;
616 char *socket_name = conf.afs_socket_arg;
617 struct sockaddr_un unix_addr;
618
619 unlink(socket_name);
620 ret = create_local_socket(socket_name, &unix_addr,
621 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
622 if (ret < 0) {
623 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
624 exit(EXIT_FAILURE);
625 }
626 socket_fd = ret;
627 if (listen(socket_fd , 5) < 0) {
628 PARA_EMERG_LOG("can not listen on socket\n");
629 exit(EXIT_FAILURE);
630 }
631 ret = mark_fd_nonblocking(socket_fd);
632 if (ret < 0) {
633 close(socket_fd);
634 return ret;
635 }
636 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
637 socket_fd);
638 return socket_fd;
639 }
640
641 static void close_afs_tables(void)
642 {
643 int i;
644 PARA_NOTICE_LOG("closing afs_tables\n");
645 for (i = 0; i < NUM_AFS_TABLES; i++)
646 afs_tables[i].close();
647 }
648
649 static char *database_dir;
650
651 static void get_database_dir(void)
652 {
653 if (!database_dir) {
654 if (conf.afs_database_dir_given)
655 database_dir = para_strdup(conf.afs_database_dir_arg);
656 else {
657 char *home = para_homedir();
658 database_dir = make_message(
659 "%s/.paraslash/afs_database-0.4", home);
660 free(home);
661 }
662 }
663 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
664 }
665
666 static int make_database_dir(void)
667 {
668 int ret;
669
670 get_database_dir();
671 ret = para_mkdir(database_dir, 0777);
672 if (ret >= 0 || is_errno(-ret, EEXIST))
673 return 1;
674 return ret;
675 }
676
677 static int open_afs_tables(void)
678 {
679 int i, ret;
680
681 get_database_dir();
682 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
683 database_dir);
684 for (i = 0; i < NUM_AFS_TABLES; i++) {
685 ret = afs_tables[i].open(database_dir);
686 if (ret >= 0)
687 continue;
688 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
689 para_strerror(-ret));
690 break;
691 }
692 if (ret >= 0)
693 return ret;
694 while (i)
695 afs_tables[--i].close();
696 return ret;
697 }
698
699 static void signal_pre_select(struct sched *s, struct task *t)
700 {
701 struct signal_task *st = container_of(t, struct signal_task, task);
702 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
703 }
704
705 static void afs_signal_post_select(struct sched *s, struct task *t)
706 {
707 int signum;
708
709 if (getppid() == 1) {
710 PARA_EMERG_LOG("para_server died\n");
711 goto shutdown;
712 }
713 signum = para_next_signal(&s->rfds);
714 if (signum == 0)
715 return;
716 if (signum == SIGHUP) {
717 close_afs_tables();
718 parse_config_or_die(1);
719 t->error = open_afs_tables();
720 if (t->error < 0)
721 return;
722 init_admissible_files(current_mop);
723 return;
724 }
725 PARA_EMERG_LOG("terminating on signal %d\n", signum);
726 shutdown:
727 sched_shutdown();
728 t->error = -E_AFS_SIGNAL;
729 }
730
731 static void register_signal_task(void)
732 {
733 struct signal_task *st = &signal_task_struct;
734
735 para_sigaction(SIGPIPE, SIG_IGN);
736 st->fd = para_signal_init();
737 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
738 para_install_sighandler(SIGINT);
739 para_install_sighandler(SIGTERM);
740 para_install_sighandler(SIGHUP);
741
742 st->task.pre_select = signal_pre_select;
743 st->task.post_select = afs_signal_post_select;
744 sprintf(st->task.status, "signal task");
745 register_task(&st->task);
746 }
747
748 static struct list_head afs_client_list;
749
750 /** Describes on connected afs client. */
751 struct afs_client {
752 /** Position in the afs client list. */
753 struct list_head node;
754 /** The socket file descriptor for this client. */
755 int fd;
756 /** The time the client connected. */
757 struct timeval connect_time;
758 };
759
760 static void command_pre_select(struct sched *s, struct task *t)
761 {
762 struct command_task *ct = container_of(t, struct command_task, task);
763 struct afs_client *client;
764
765 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
766 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
767 list_for_each_entry(client, &afs_client_list, node)
768 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
769 }
770
771 /**
772 * Send data as shared memory to a file descriptor.
773 *
774 * \param buf The buffer holding the data to be sent.
775 * \param size The size of \a buf.
776 * \param fd_ptr A pointer to the file descriptor.
777 *
778 * This function is used as the \a max_size handler in a \ref para_buffer
779 * structure. If used this way, it is called by \ref para_printf() whenever
780 * the buffer passed to para_printf() is about to exceed its maximal size.
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 given by \a fd_ptr.
785 *
786 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
787 * and positive on success.
788 */
789 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
790 {
791 int ret, shmid, fd = *(int *)fd_ptr;
792 void *shm;
793 struct callback_result *cr;
794
795 if (!buf || !size)
796 return 0;
797 ret = shm_new(size + sizeof(struct callback_result));
798 if (ret < 0)
799 return ret;
800 shmid = ret;
801 ret = shm_attach(shmid, ATTACH_RW, &shm);
802 if (ret < 0)
803 goto err;
804 cr = shm;
805 cr->result_size = size;
806 memcpy(shm + sizeof(*cr), buf, size);
807 ret = shm_detach(shm);
808 if (ret < 0)
809 goto err;
810 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
811 if (ret >= 0)
812 return ret;
813 err:
814 if (shm_destroy(shmid) < 0)
815 PARA_ERROR_LOG("destroy result failed\n");
816 return ret;
817 }
818
819 /*
820 * On errors, negative value is written to fd.
821 * On success: If query produced a result, the result_shmid is written to fd.
822 * Otherwise, zero is written.
823 */
824 static int call_callback(int fd, int query_shmid)
825 {
826 void *query_shm;
827 struct callback_query *cq;
828 struct osl_object query;
829 int ret;
830
831 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
832 if (ret < 0)
833 return ret;
834 cq = query_shm;
835 query.data = (char *)query_shm + sizeof(*cq);
836 query.size = cq->query_size;
837 cq->handler(fd, &query);
838 return shm_detach(query_shm);
839 }
840
841 static int execute_server_command(fd_set *rfds)
842 {
843 char buf[8];
844 size_t n;
845 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
846
847 if (ret < 0 || n == 0)
848 return ret;
849 buf[n] = '\0';
850 if (strcmp(buf, "new"))
851 return -E_BAD_CMD;
852 return open_next_audio_file();
853 }
854
855 /* returns 0 if no data available, 1 else */
856 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
857 {
858 uint32_t cookie;
859 int query_shmid;
860 char buf[sizeof(cookie) + sizeof(query_shmid)];
861 size_t n;
862 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
863
864 if (ret < 0)
865 goto err;
866 if (n == 0)
867 return 0;
868 if (n != sizeof(buf)) {
869 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
870 ret, (long unsigned) sizeof(buf));
871 return 1;
872 }
873 cookie = *(uint32_t *)buf;
874 if (cookie != expected_cookie) {
875 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
876 (unsigned)cookie, (unsigned)expected_cookie);
877 return 1;
878 }
879 query_shmid = *(int *)(buf + sizeof(cookie));
880 if (query_shmid < 0) {
881 PARA_WARNING_LOG("received invalid query shmid %d)\n",
882 query_shmid);
883 return 1;
884 }
885 ret = call_callback(fd, query_shmid);
886 if (ret >= 0)
887 return 1;
888 err:
889 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
890 return 1;
891 }
892
893 /** Shutdown connection if query has not arrived until this many seconds. */
894 #define AFS_CLIENT_TIMEOUT 3
895
896 static void command_post_select(struct sched *s, struct task *t)
897 {
898 struct command_task *ct = container_of(t, struct command_task, task);
899 struct sockaddr_un unix_addr;
900 struct afs_client *client, *tmp;
901 int fd, ret;
902
903 ret = execute_server_command(&s->rfds);
904 if (ret < 0) {
905 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
906 sched_shutdown();
907 return;
908 }
909 /* Check the list of connected clients. */
910 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
911 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
912 if (ret == 0) { /* prevent bogus connection flooding */
913 struct timeval diff;
914 tv_diff(now, &client->connect_time, &diff);
915 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
916 continue;
917 PARA_WARNING_LOG("connection timeout\n");
918 }
919 close(client->fd);
920 list_del(&client->node);
921 free(client);
922 }
923 /* Accept connections on the local socket. */
924 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
925 if (ret < 0)
926 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
927 if (ret <= 0)
928 return;
929 ret = mark_fd_nonblocking(fd);
930 if (ret < 0) {
931 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
932 close(fd);
933 return;
934 }
935 client = para_malloc(sizeof(*client));
936 client->fd = fd;
937 client->connect_time = *now;
938 para_list_add(&client->node, &afs_client_list);
939 }
940
941 static void register_command_task(uint32_t cookie)
942 {
943 struct command_task *ct = &command_task_struct;
944 ct->fd = setup_command_socket_or_die();
945 ct->cookie = cookie;
946
947 ct->task.pre_select = command_pre_select;
948 ct->task.post_select = command_post_select;
949 sprintf(ct->task.status, "afs command task");
950 register_task(&ct->task);
951 }
952
953 /**
954 * Initialize the audio file selector process.
955 *
956 * \param cookie The value used for "authentication".
957 * \param socket_fd File descriptor used for communication with the server.
958 */
959 __noreturn void afs_init(uint32_t cookie, int socket_fd)
960 {
961 static struct sched s;
962 int i, ret;
963
964 register_signal_task();
965 INIT_LIST_HEAD(&afs_client_list);
966 for (i = 0; i < NUM_AFS_TABLES; i++)
967 afs_tables[i].init(&afs_tables[i]);
968 ret = open_afs_tables();
969 if (ret < 0)
970 goto out;
971 server_socket = socket_fd;
972 ret = mark_fd_nonblocking(server_socket);
973 if (ret < 0)
974 goto out_close;
975 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
976 server_socket, (unsigned) cookie);
977 init_admissible_files(conf.afs_initial_mode_arg);
978 register_command_task(cookie);
979 s.default_timeout.tv_sec = 0;
980 s.default_timeout.tv_usec = 999 * 1000;
981 ret = schedule(&s);
982 out_close:
983 close_afs_tables();
984 out:
985 if (ret < 0)
986 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
987 exit(EXIT_FAILURE);
988 }
989
990 static void create_tables_callback(int fd, const struct osl_object *query)
991 {
992 uint32_t table_mask = *(uint32_t *)query->data;
993 int i, ret;
994 struct para_buffer pb = {.buf = NULL};
995
996 close_afs_tables();
997 for (i = 0; i < NUM_AFS_TABLES; i++) {
998 struct afs_table *t = &afs_tables[i];
999
1000 if (!(table_mask & (1 << i)))
1001 continue;
1002 if (!t->create)
1003 continue;
1004 ret = t->create(database_dir);
1005 if (ret < 0)
1006 goto out;
1007 para_printf(&pb, "successfully created %s table\n", t->name);
1008 }
1009 ret = open_afs_tables();
1010 out:
1011 if (ret < 0)
1012 para_printf(&pb, "%s\n", para_strerror(-ret));
1013 if (pb.buf)
1014 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1015 free(pb.buf);
1016 }
1017
1018 int com_init(struct stream_cipher_context *scc, int argc, char * const * const argv)
1019 {
1020 int i, j, ret;
1021 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1022 struct osl_object query = {.data = &table_mask,
1023 .size = sizeof(table_mask)};
1024
1025 ret = make_database_dir();
1026 if (ret < 0)
1027 return ret;
1028 if (argc != 1) {
1029 table_mask = 0;
1030 for (i = 1; i < argc; i++) {
1031 for (j = 0; j < NUM_AFS_TABLES; j++) {
1032 struct afs_table *t = &afs_tables[j];
1033
1034 if (strcmp(argv[i], t->name))
1035 continue;
1036 table_mask |= (1 << j);
1037 break;
1038 }
1039 if (j == NUM_AFS_TABLES)
1040 return -E_BAD_TABLE_NAME;
1041 }
1042 }
1043 ret = send_callback_request(create_tables_callback, &query,
1044 sc_send_result, scc);
1045 if (ret < 0)
1046 return sc_send_va_buffer(scc, "%s\n", para_strerror(-ret));
1047 return ret;
1048 }
1049
1050 /**
1051 * Flags for the check command.
1052 *
1053 * \sa com_check().
1054 */
1055 enum com_check_flags {
1056 /** Check the audio file table. */
1057 CHECK_AFT = 1,
1058 /** Check the mood table. */
1059 CHECK_MOODS = 2,
1060 /** Check the playlist table. */
1061 CHECK_PLAYLISTS = 4
1062 };
1063
1064 int com_check(struct stream_cipher_context *scc, int argc, char * const * const argv)
1065 {
1066 unsigned flags = 0;
1067 int i, ret;
1068
1069 for (i = 1; i < argc; i++) {
1070 const char *arg = argv[i];
1071 if (arg[0] != '-')
1072 break;
1073 if (!strcmp(arg, "--")) {
1074 i++;
1075 break;
1076 }
1077 if (!strcmp(arg, "-a")) {
1078 flags |= CHECK_AFT;
1079 continue;
1080 }
1081 if (!strcmp(arg, "-p")) {
1082 flags |= CHECK_PLAYLISTS;
1083 continue;
1084 }
1085 if (!strcmp(arg, "-m")) {
1086 flags |= CHECK_MOODS;
1087 continue;
1088 }
1089 return -E_AFS_SYNTAX;
1090 }
1091 if (i < argc)
1092 return -E_AFS_SYNTAX;
1093 if (!flags)
1094 flags = ~0U;
1095 if (flags & CHECK_AFT) {
1096 ret = send_callback_request(aft_check_callback, NULL,
1097 sc_send_result, scc);
1098 if (ret < 0)
1099 return ret;
1100 }
1101 if (flags & CHECK_PLAYLISTS) {
1102 ret = send_callback_request(playlist_check_callback,
1103 NULL, sc_send_result, scc);
1104 if (ret < 0)
1105 return ret;
1106 }
1107 if (flags & CHECK_MOODS) {
1108 ret = send_callback_request(mood_check_callback, NULL,
1109 sc_send_result, scc);
1110 if (ret < 0)
1111 return ret;
1112 }
1113 return 1;
1114 }
1115
1116 /**
1117 * The afs event dispatcher.
1118 *
1119 * \param event Type of the event.
1120 * \param pb May be \p NULL.
1121 * \param data Type depends on \a event.
1122 *
1123 * This function calls the table handlers of all tables and passes \a pb and \a
1124 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1125 */
1126 void afs_event(enum afs_events event, struct para_buffer *pb,
1127 void *data)
1128 {
1129 int i, ret;
1130
1131 for (i = 0; i < NUM_AFS_TABLES; i++) {
1132 struct afs_table *t = &afs_tables[i];
1133 if (!t->event_handler)
1134 continue;
1135 ret = t->event_handler(event, pb, data);
1136 if (ret < 0)
1137 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1138 event, para_strerror(-ret));
1139 }
1140 }
1141
1142 /**
1143 * Dummy event handler for the images table.
1144 *
1145 * \param event Unused.
1146 * \param pb Unused.
1147 * \param data Unused.
1148 *
1149 * This table does not honor events.
1150 */
1151 __a_const int images_event_handler(__a_unused enum afs_events event,
1152 __a_unused struct para_buffer *pb, __a_unused void *data)
1153 {
1154 return 1;
1155 }
1156
1157 /**
1158 * Dummy event handler for the lyrics table.
1159 *
1160 * \param event Unused.
1161 * \param pb Unused.
1162 * \param data Unused.
1163 *
1164 * This table does not honor events.
1165 */
1166 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1167 __a_unused struct para_buffer *pb, __a_unused void *data)
1168 {
1169 return 1;
1170 }