Change year in copyright message to 2012.
[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
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 * \return The return value of the underlying call to \ref
290 * send_callback_request().
291 *
292 * \sa send_standard_callback_request(), send_callback_request().
293 */
294 int send_option_arg_callback_request(struct osl_object *options,
295 int argc, char * const * const argv, callback_function *f,
296 callback_result_handler *result_handler,
297 void *private_result_data)
298 {
299 char *p;
300 int i, ret;
301 struct osl_object query = {.size = options? options->size : 0};
302
303 for (i = 0; i < argc; i++)
304 query.size += strlen(argv[i]) + 1;
305 query.data = para_malloc(query.size);
306 p = query.data;
307 if (options) {
308 memcpy(query.data, options->data, options->size);
309 p += options->size;
310 }
311 for (i = 0; i < argc; i++) {
312 strcpy(p, argv[i]); /* OK */
313 p += strlen(argv[i]) + 1;
314 }
315 ret = send_callback_request(f, &query, result_handler,
316 private_result_data);
317 free(query.data);
318 return ret;
319 }
320
321 /**
322 * Send a callback request with an argument vector only.
323 *
324 * \param argc The same meaning as in send_option_arg_callback_request().
325 * \param argv The same meaning as in send_option_arg_callback_request().
326 * \param f The same meaning as in send_option_arg_callback_request().
327 * \param result_handler See \ref send_callback_request.
328 * \param private_result_data See \ref send_callback_request.
329 *
330 * This is similar to send_option_arg_callback_request(), but no options buffer
331 * is passed to the parent process.
332 *
333 * \return The return value of the underlying call to
334 * send_option_arg_callback_request().
335 */
336 int send_standard_callback_request(int argc, char * const * const argv,
337 callback_function *f, callback_result_handler *result_handler,
338 void *private_result_data)
339 {
340 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
341 private_result_data);
342 }
343
344 static int action_if_pattern_matches(struct osl_row *row, void *data)
345 {
346 struct pattern_match_data *pmd = data;
347 struct osl_object name_obj;
348 const char *p, *name;
349 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
350 const char *pattern_txt = (const char *)pmd->patterns.data;
351
352 if (ret < 0)
353 return ret;
354 name = (char *)name_obj.data;
355 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
356 return 1;
357 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
358 return pmd->action(pmd->table, row, name, pmd->data);
359 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
360 p += strlen(p) + 1) {
361 ret = fnmatch(p, name, pmd->fnmatch_flags);
362 if (ret == FNM_NOMATCH)
363 continue;
364 if (ret)
365 return -E_FNMATCH;
366 ret = pmd->action(pmd->table, row, name, pmd->data);
367 if (ret >= 0)
368 pmd->num_matches++;
369 return ret;
370 }
371 return 1;
372 }
373
374 /**
375 * Execute the given function for each matching row.
376 *
377 * \param pmd Describes what to match and how.
378 *
379 * \return Standard.
380 */
381 int for_each_matching_row(struct pattern_match_data *pmd)
382 {
383 if (pmd->pm_flags & PM_REVERSE_LOOP)
384 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
385 action_if_pattern_matches));
386 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
387 action_if_pattern_matches));
388 }
389
390 /**
391 * Compare two osl objects of string type.
392 *
393 * \param obj1 Pointer to the first object.
394 * \param obj2 Pointer to the second object.
395 *
396 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
397 * are taken into account.
398 *
399 * \return It returns an integer less than, equal to, or greater than zero if
400 * \a obj1 is found, respectively, to be less than, to match, or be greater than
401 * obj2.
402 *
403 * \sa strcmp(3), strncmp(3), osl_compare_func.
404 */
405 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
406 {
407 const char *str1 = (const char *)obj1->data;
408 const char *str2 = (const char *)obj2->data;
409 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
410 }
411
412 static int pass_afd(int fd, char *buf, size_t size)
413 {
414 struct msghdr msg = {.msg_iov = NULL};
415 struct cmsghdr *cmsg;
416 char control[255];
417 int ret;
418 struct iovec iov;
419
420 iov.iov_base = buf;
421 iov.iov_len = size;
422
423 msg.msg_iov = &iov;
424 msg.msg_iovlen = 1;
425
426 msg.msg_control = control;
427 msg.msg_controllen = sizeof(control);
428
429 cmsg = CMSG_FIRSTHDR(&msg);
430 cmsg->cmsg_level = SOL_SOCKET;
431 cmsg->cmsg_type = SCM_RIGHTS;
432 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
433 *(int *)CMSG_DATA(cmsg) = fd;
434
435 /* Sum of the length of all control messages in the buffer */
436 msg.msg_controllen = cmsg->cmsg_len;
437 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
438 ret = sendmsg(server_socket, &msg, 0);
439 if (ret < 0) {
440 ret = -ERRNO_TO_PARA_ERROR(errno);
441 return ret;
442 }
443 return 1;
444 }
445
446 /**
447 * Open the audio file with highest score.
448 *
449 * This stores all information for streaming the "best" audio file in a shared
450 * memory area. The id of that area and an open file descriptor for the next
451 * audio file are passed to the server process.
452 *
453 * \return Standard.
454 *
455 * \sa open_and_update_audio_file().
456 */
457 static int open_next_audio_file(void)
458 {
459 struct osl_row *aft_row;
460 struct audio_file_data afd;
461 int ret, shmid;
462 char buf[8];
463 long score;
464 again:
465 PARA_NOTICE_LOG("getting next audio file\n");
466 ret = score_get_best(&aft_row, &score);
467 if (ret < 0) {
468 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
469 goto no_admissible_files;
470 }
471 ret = open_and_update_audio_file(aft_row, score, &afd);
472 if (ret < 0) {
473 ret = score_delete(aft_row);
474 if (ret < 0) {
475 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
476 goto no_admissible_files;
477 }
478 goto again;
479 }
480 shmid = ret;
481 if (!write_ok(server_socket)) {
482 ret = -E_AFS_SOCKET;
483 goto destroy;
484 }
485 *(uint32_t *)buf = NEXT_AUDIO_FILE;
486 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
487 ret = pass_afd(afd.fd, buf, 8);
488 close(afd.fd);
489 if (ret >= 0)
490 return ret;
491 destroy:
492 shm_destroy(shmid);
493 return ret;
494 no_admissible_files:
495 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
496 *(uint32_t *)(buf + 4) = (uint32_t)0;
497 return send_bin_buffer(server_socket, buf, 8);
498 }
499
500 /* Never fails if arg == NULL */
501 static int activate_mood_or_playlist(char *arg, int *num_admissible)
502 {
503 enum play_mode mode;
504 int ret;
505
506 if (!arg) {
507 ret = change_current_mood(NULL); /* always successful */
508 mode = PLAY_MODE_MOOD;
509 } else {
510 if (!strncmp(arg, "p/", 2)) {
511 ret = playlist_open(arg + 2);
512 mode = PLAY_MODE_PLAYLIST;
513 } else if (!strncmp(arg, "m/", 2)) {
514 ret = change_current_mood(arg + 2);
515 mode = PLAY_MODE_MOOD;
516 } else
517 return -E_AFS_SYNTAX;
518 if (ret < 0)
519 return ret;
520 }
521 if (num_admissible)
522 *num_admissible = ret;
523 current_play_mode = mode;
524 if (arg != current_mop) {
525 free(current_mop);
526 if (arg) {
527 current_mop = para_strdup(arg);
528 mutex_lock(mmd_mutex);
529 strncpy(mmd->afs_mode_string, arg,
530 sizeof(mmd->afs_mode_string));
531 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
532 mutex_unlock(mmd_mutex);
533 } else {
534 mutex_lock(mmd_mutex);
535 strcpy(mmd->afs_mode_string, "dummy");
536 mutex_unlock(mmd_mutex);
537 current_mop = NULL;
538 }
539 }
540 return 1;
541 }
542
543 static void com_select_callback(int fd, const struct osl_object *query)
544 {
545 struct para_buffer pb = {
546 .max_size = shm_get_shmmax(),
547 .private_data = &fd,
548 .max_size_handler = pass_buffer_as_shm
549 };
550 char *arg = query->data;
551 int num_admissible, ret, ret2;
552
553 ret = clear_score_table();
554 if (ret < 0) {
555 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
556 goto out;
557 }
558 if (current_play_mode == PLAY_MODE_MOOD)
559 close_current_mood();
560 else
561 playlist_close();
562 ret = activate_mood_or_playlist(arg, &num_admissible);
563 if (ret < 0) {
564 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
565 para_strerror(-ret), current_mop?
566 current_mop : "dummy");
567 ret = activate_mood_or_playlist(current_mop, &num_admissible);
568 if (ret < 0) {
569 if (ret2 >= 0)
570 ret2 = para_printf(&pb, "failed, switching to dummy\n");
571 activate_mood_or_playlist(NULL, &num_admissible);
572 }
573 } else
574 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
575 current_mop : "dummy mood", num_admissible);
576 out:
577 if (ret2 >= 0 && pb.offset)
578 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
579 free(pb.buf);
580 }
581
582 /**
583 * Result handler for sending data to the para_client process.
584 *
585 * \param result The data to be sent.
586 * \param private Pointer to the context.
587 *
588 * \return The return value of the underlying call to sc_send_bin_buffer().
589 *
590 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
591 */
592 int sc_send_result(struct osl_object *result, void *private)
593 {
594 struct stream_cipher_context *scc = private;
595
596 if (!result->size)
597 return 1;
598 return sc_send_bin_buffer(scc, result->data, result->size);
599 }
600
601 int com_select(struct stream_cipher_context *scc, int argc, char * const * const argv)
602 {
603 struct osl_object query;
604
605 if (argc != 2)
606 return -E_AFS_SYNTAX;
607 query.data = argv[1];
608 query.size = strlen(argv[1]) + 1;
609 return send_callback_request(com_select_callback, &query,
610 &sc_send_result, scc);
611 }
612
613 static void init_admissible_files(char *arg)
614 {
615 if (activate_mood_or_playlist(arg, NULL) < 0)
616 activate_mood_or_playlist(NULL, NULL); /* always successful */
617 }
618
619 static int setup_command_socket_or_die(void)
620 {
621 int ret, socket_fd;
622 char *socket_name = conf.afs_socket_arg;
623 struct sockaddr_un unix_addr;
624
625 unlink(socket_name);
626 ret = create_local_socket(socket_name, &unix_addr,
627 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
628 if (ret < 0) {
629 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
630 exit(EXIT_FAILURE);
631 }
632 socket_fd = ret;
633 if (listen(socket_fd , 5) < 0) {
634 PARA_EMERG_LOG("can not listen on socket\n");
635 exit(EXIT_FAILURE);
636 }
637 ret = mark_fd_nonblocking(socket_fd);
638 if (ret < 0) {
639 close(socket_fd);
640 return ret;
641 }
642 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
643 socket_fd);
644 return socket_fd;
645 }
646
647 static void close_afs_tables(void)
648 {
649 int i;
650 PARA_NOTICE_LOG("closing afs_tables\n");
651 for (i = 0; i < NUM_AFS_TABLES; i++)
652 afs_tables[i].close();
653 }
654
655 static char *database_dir;
656
657 static void get_database_dir(void)
658 {
659 if (!database_dir) {
660 if (conf.afs_database_dir_given)
661 database_dir = para_strdup(conf.afs_database_dir_arg);
662 else {
663 char *home = para_homedir();
664 database_dir = make_message(
665 "%s/.paraslash/afs_database-0.4", home);
666 free(home);
667 }
668 }
669 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
670 }
671
672 static int make_database_dir(void)
673 {
674 int ret;
675
676 get_database_dir();
677 ret = para_mkdir(database_dir, 0777);
678 if (ret >= 0 || is_errno(-ret, EEXIST))
679 return 1;
680 return ret;
681 }
682
683 static int open_afs_tables(void)
684 {
685 int i, ret;
686
687 get_database_dir();
688 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
689 database_dir);
690 for (i = 0; i < NUM_AFS_TABLES; i++) {
691 ret = afs_tables[i].open(database_dir);
692 if (ret >= 0)
693 continue;
694 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
695 para_strerror(-ret));
696 break;
697 }
698 if (ret >= 0)
699 return ret;
700 while (i)
701 afs_tables[--i].close();
702 return ret;
703 }
704
705 static void signal_pre_select(struct sched *s, struct task *t)
706 {
707 struct signal_task *st = container_of(t, struct signal_task, task);
708 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
709 }
710
711 static void afs_signal_post_select(struct sched *s, struct task *t)
712 {
713 int signum;
714
715 if (getppid() == 1) {
716 PARA_EMERG_LOG("para_server died\n");
717 goto shutdown;
718 }
719 signum = para_next_signal(&s->rfds);
720 if (signum == 0)
721 return;
722 if (signum == SIGHUP) {
723 close_afs_tables();
724 parse_config_or_die(1);
725 t->error = open_afs_tables();
726 if (t->error < 0)
727 return;
728 init_admissible_files(current_mop);
729 return;
730 }
731 PARA_EMERG_LOG("terminating on signal %d\n", signum);
732 shutdown:
733 sched_shutdown(s);
734 t->error = -E_AFS_SIGNAL;
735 }
736
737 static void register_signal_task(struct sched *s)
738 {
739 struct signal_task *st = &signal_task_struct;
740
741 para_sigaction(SIGPIPE, SIG_IGN);
742 st->fd = para_signal_init();
743 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
744 para_install_sighandler(SIGINT);
745 para_install_sighandler(SIGTERM);
746 para_install_sighandler(SIGHUP);
747
748 st->task.pre_select = signal_pre_select;
749 st->task.post_select = afs_signal_post_select;
750 sprintf(st->task.status, "signal task");
751 register_task(s, &st->task);
752 }
753
754 static struct list_head afs_client_list;
755
756 /** Describes on connected afs client. */
757 struct afs_client {
758 /** Position in the afs client list. */
759 struct list_head node;
760 /** The socket file descriptor for this client. */
761 int fd;
762 /** The time the client connected. */
763 struct timeval connect_time;
764 };
765
766 static void command_pre_select(struct sched *s, struct task *t)
767 {
768 struct command_task *ct = container_of(t, struct command_task, task);
769 struct afs_client *client;
770
771 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
772 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
773 list_for_each_entry(client, &afs_client_list, node)
774 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
775 }
776
777 /**
778 * Send data as shared memory to a file descriptor.
779 *
780 * \param buf The buffer holding the data to be sent.
781 * \param size The size of \a buf.
782 * \param fd_ptr A pointer to the file descriptor.
783 *
784 * This function is used as the \a max_size handler in a \ref para_buffer
785 * structure. If used this way, it is called by \ref para_printf() whenever
786 * the buffer passed to para_printf() is about to exceed its maximal size.
787 *
788 * This function creates a shared memory area large enough to hold
789 * the content given by \a buf and \a size and sends the identifier
790 * of this area to the file descriptor given by \a fd_ptr.
791 *
792 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
793 * and positive on success.
794 */
795 int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
796 {
797 int ret, shmid, fd = *(int *)fd_ptr;
798 void *shm;
799 struct callback_result *cr;
800
801 if (!buf || !size)
802 return 0;
803 ret = shm_new(size + sizeof(struct callback_result));
804 if (ret < 0)
805 return ret;
806 shmid = ret;
807 ret = shm_attach(shmid, ATTACH_RW, &shm);
808 if (ret < 0)
809 goto err;
810 cr = shm;
811 cr->result_size = size;
812 memcpy(shm + sizeof(*cr), buf, size);
813 ret = shm_detach(shm);
814 if (ret < 0)
815 goto err;
816 ret = send_bin_buffer(fd, (char *)&shmid, sizeof(int));
817 if (ret >= 0)
818 return ret;
819 err:
820 if (shm_destroy(shmid) < 0)
821 PARA_ERROR_LOG("destroy result failed\n");
822 return ret;
823 }
824
825 /*
826 * On errors, negative value is written to fd.
827 * On success: If query produced a result, the result_shmid is written to fd.
828 * Otherwise, zero is written.
829 */
830 static int call_callback(int fd, int query_shmid)
831 {
832 void *query_shm;
833 struct callback_query *cq;
834 struct osl_object query;
835 int ret;
836
837 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
838 if (ret < 0)
839 return ret;
840 cq = query_shm;
841 query.data = (char *)query_shm + sizeof(*cq);
842 query.size = cq->query_size;
843 cq->handler(fd, &query);
844 return shm_detach(query_shm);
845 }
846
847 static int execute_server_command(fd_set *rfds)
848 {
849 char buf[8];
850 size_t n;
851 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
852
853 if (ret < 0 || n == 0)
854 return ret;
855 buf[n] = '\0';
856 if (strcmp(buf, "new"))
857 return -E_BAD_CMD;
858 return open_next_audio_file();
859 }
860
861 /* returns 0 if no data available, 1 else */
862 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
863 {
864 uint32_t cookie;
865 int query_shmid;
866 char buf[sizeof(cookie) + sizeof(query_shmid)];
867 size_t n;
868 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
869
870 if (ret < 0)
871 goto err;
872 if (n == 0)
873 return 0;
874 if (n != sizeof(buf)) {
875 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
876 ret, (long unsigned) sizeof(buf));
877 return 1;
878 }
879 cookie = *(uint32_t *)buf;
880 if (cookie != expected_cookie) {
881 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
882 (unsigned)cookie, (unsigned)expected_cookie);
883 return 1;
884 }
885 query_shmid = *(int *)(buf + sizeof(cookie));
886 if (query_shmid < 0) {
887 PARA_WARNING_LOG("received invalid query shmid %d)\n",
888 query_shmid);
889 return 1;
890 }
891 ret = call_callback(fd, query_shmid);
892 if (ret >= 0)
893 return 1;
894 err:
895 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
896 return 1;
897 }
898
899 /** Shutdown connection if query has not arrived until this many seconds. */
900 #define AFS_CLIENT_TIMEOUT 3
901
902 static void command_post_select(struct sched *s, struct task *t)
903 {
904 struct command_task *ct = container_of(t, struct command_task, task);
905 struct sockaddr_un unix_addr;
906 struct afs_client *client, *tmp;
907 int fd, ret;
908
909 ret = execute_server_command(&s->rfds);
910 if (ret < 0) {
911 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
912 sched_shutdown(s);
913 return;
914 }
915 /* Check the list of connected clients. */
916 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
917 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
918 if (ret == 0) { /* prevent bogus connection flooding */
919 struct timeval diff;
920 tv_diff(now, &client->connect_time, &diff);
921 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
922 continue;
923 PARA_WARNING_LOG("connection timeout\n");
924 }
925 close(client->fd);
926 list_del(&client->node);
927 free(client);
928 }
929 /* Accept connections on the local socket. */
930 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
931 if (ret < 0)
932 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
933 if (ret <= 0)
934 return;
935 ret = mark_fd_nonblocking(fd);
936 if (ret < 0) {
937 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
938 close(fd);
939 return;
940 }
941 client = para_malloc(sizeof(*client));
942 client->fd = fd;
943 client->connect_time = *now;
944 para_list_add(&client->node, &afs_client_list);
945 }
946
947 static void register_command_task(uint32_t cookie, struct sched *s)
948 {
949 struct command_task *ct = &command_task_struct;
950 ct->fd = setup_command_socket_or_die();
951 ct->cookie = cookie;
952
953 ct->task.pre_select = command_pre_select;
954 ct->task.post_select = command_post_select;
955 sprintf(ct->task.status, "afs command task");
956 register_task(s, &ct->task);
957 }
958
959 /**
960 * Initialize the audio file selector process.
961 *
962 * \param cookie The value used for "authentication".
963 * \param socket_fd File descriptor used for communication with the server.
964 */
965 __noreturn void afs_init(uint32_t cookie, int socket_fd)
966 {
967 static struct sched s;
968 int i, ret;
969
970 register_signal_task(&s);
971 INIT_LIST_HEAD(&afs_client_list);
972 for (i = 0; i < NUM_AFS_TABLES; i++)
973 afs_tables[i].init(&afs_tables[i]);
974 ret = open_afs_tables();
975 if (ret < 0)
976 goto out;
977 server_socket = socket_fd;
978 ret = mark_fd_nonblocking(server_socket);
979 if (ret < 0)
980 goto out_close;
981 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
982 server_socket, (unsigned) cookie);
983 init_admissible_files(conf.afs_initial_mode_arg);
984 register_command_task(cookie, &s);
985 s.default_timeout.tv_sec = 0;
986 s.default_timeout.tv_usec = 999 * 1000;
987 ret = schedule(&s);
988 out_close:
989 close_afs_tables();
990 out:
991 if (ret < 0)
992 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
993 exit(EXIT_FAILURE);
994 }
995
996 static void create_tables_callback(int fd, const struct osl_object *query)
997 {
998 uint32_t table_mask = *(uint32_t *)query->data;
999 int i, ret;
1000 struct para_buffer pb = {.buf = NULL};
1001
1002 close_afs_tables();
1003 for (i = 0; i < NUM_AFS_TABLES; i++) {
1004 struct afs_table *t = &afs_tables[i];
1005
1006 if (!(table_mask & (1 << i)))
1007 continue;
1008 if (!t->create)
1009 continue;
1010 ret = t->create(database_dir);
1011 if (ret < 0)
1012 goto out;
1013 para_printf(&pb, "successfully created %s table\n", t->name);
1014 }
1015 ret = open_afs_tables();
1016 out:
1017 if (ret < 0)
1018 para_printf(&pb, "%s\n", para_strerror(-ret));
1019 if (pb.buf)
1020 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
1021 free(pb.buf);
1022 }
1023
1024 int com_init(struct stream_cipher_context *scc, int argc, char * const * const argv)
1025 {
1026 int i, j, ret;
1027 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1028 struct osl_object query = {.data = &table_mask,
1029 .size = sizeof(table_mask)};
1030
1031 ret = make_database_dir();
1032 if (ret < 0)
1033 return ret;
1034 if (argc != 1) {
1035 table_mask = 0;
1036 for (i = 1; i < argc; i++) {
1037 for (j = 0; j < NUM_AFS_TABLES; j++) {
1038 struct afs_table *t = &afs_tables[j];
1039
1040 if (strcmp(argv[i], t->name))
1041 continue;
1042 table_mask |= (1 << j);
1043 break;
1044 }
1045 if (j == NUM_AFS_TABLES)
1046 return -E_BAD_TABLE_NAME;
1047 }
1048 }
1049 ret = send_callback_request(create_tables_callback, &query,
1050 sc_send_result, scc);
1051 if (ret < 0)
1052 /* ignore return value */
1053 sc_send_va_buffer(scc, "%s\n", para_strerror(-ret));
1054 return ret;
1055 }
1056
1057 /**
1058 * Flags for the check command.
1059 *
1060 * \sa com_check().
1061 */
1062 enum com_check_flags {
1063 /** Check the audio file table. */
1064 CHECK_AFT = 1,
1065 /** Check the mood table. */
1066 CHECK_MOODS = 2,
1067 /** Check the playlist table. */
1068 CHECK_PLAYLISTS = 4
1069 };
1070
1071 int com_check(struct stream_cipher_context *scc, int argc, char * const * const argv)
1072 {
1073 unsigned flags = 0;
1074 int i, ret;
1075
1076 for (i = 1; i < argc; i++) {
1077 const char *arg = argv[i];
1078 if (arg[0] != '-')
1079 break;
1080 if (!strcmp(arg, "--")) {
1081 i++;
1082 break;
1083 }
1084 if (!strcmp(arg, "-a")) {
1085 flags |= CHECK_AFT;
1086 continue;
1087 }
1088 if (!strcmp(arg, "-p")) {
1089 flags |= CHECK_PLAYLISTS;
1090 continue;
1091 }
1092 if (!strcmp(arg, "-m")) {
1093 flags |= CHECK_MOODS;
1094 continue;
1095 }
1096 return -E_AFS_SYNTAX;
1097 }
1098 if (i < argc)
1099 return -E_AFS_SYNTAX;
1100 if (!flags)
1101 flags = ~0U;
1102 if (flags & CHECK_AFT) {
1103 ret = send_callback_request(aft_check_callback, NULL,
1104 sc_send_result, scc);
1105 if (ret < 0)
1106 return ret;
1107 }
1108 if (flags & CHECK_PLAYLISTS) {
1109 ret = send_callback_request(playlist_check_callback,
1110 NULL, sc_send_result, scc);
1111 if (ret < 0)
1112 return ret;
1113 }
1114 if (flags & CHECK_MOODS) {
1115 ret = send_callback_request(mood_check_callback, NULL,
1116 sc_send_result, scc);
1117 if (ret < 0)
1118 return ret;
1119 }
1120 return 1;
1121 }
1122
1123 /**
1124 * The afs event dispatcher.
1125 *
1126 * \param event Type of the event.
1127 * \param pb May be \p NULL.
1128 * \param data Type depends on \a event.
1129 *
1130 * This function calls the table handlers of all tables and passes \a pb and \a
1131 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1132 */
1133 void afs_event(enum afs_events event, struct para_buffer *pb,
1134 void *data)
1135 {
1136 int i, ret;
1137
1138 for (i = 0; i < NUM_AFS_TABLES; i++) {
1139 struct afs_table *t = &afs_tables[i];
1140 if (!t->event_handler)
1141 continue;
1142 ret = t->event_handler(event, pb, data);
1143 if (ret < 0)
1144 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1145 event, para_strerror(-ret));
1146 }
1147 }
1148
1149 /**
1150 * Dummy event handler for the images table.
1151 *
1152 * \param event Unused.
1153 * \param pb Unused.
1154 * \param data Unused.
1155 *
1156 * \return The images table does not honor events, so this handler always
1157 * returns success.
1158 */
1159 __a_const int images_event_handler(__a_unused enum afs_events event,
1160 __a_unused struct para_buffer *pb, __a_unused void *data)
1161 {
1162 return 1;
1163 }
1164
1165 /**
1166 * Dummy event handler for the lyrics table.
1167 *
1168 * \param event Unused.
1169 * \param pb Unused.
1170 * \param data Unused.
1171 *
1172 * \return The lyrics table does not honor events, so this handler always
1173 * returns success.
1174 */
1175 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1176 __a_unused struct para_buffer *pb, __a_unused void *data)
1177 {
1178 return 1;
1179 }