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