Introduce para_regcomp.
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2009 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 <openssl/rc4.h>
13 #include <osl.h>
14
15 #include "server.cmdline.h"
16 #include "para.h"
17 #include "error.h"
18 #include "crypt.h"
19 #include "string.h"
20 #include "afh.h"
21 #include "afs.h"
22 #include "server.h"
23 #include <dirent.h> /* readdir() */
24 #include <sys/mman.h>
25 #include <sys/time.h>
26 #include "net.h"
27 #include "ipc.h"
28 #include "list.h"
29 #include "sched.h"
30 #include "signal.h"
31 #include "fd.h"
32
33 /** The osl tables used by afs. \sa blob.c. */
34 enum afs_table_num {
35 /** Contains audio file information. See aft.c. */
36 TBLNUM_AUDIO_FILES,
37 /** The table for the paraslash attributes. See attribute.c. */
38 TBLNUM_ATTRIBUTES,
39 /**
40 * Paraslash's scoring system is based on Gaussian normal
41 * distributions, and the relevant data is stored in the rbtrees of an
42 * osl table containing only volatile columns. See score.c for
43 * details.
44 */
45 TBLNUM_SCORES,
46 /**
47 * A standard blob table containing the mood definitions. For details
48 * see mood.c.
49 */
50 TBLNUM_MOODS,
51 /** A blob table containing lyrics on a per-song basis. */
52 TBLNUM_LYRICS,
53 /** Another blob table for images (for example album cover art). */
54 TBLNUM_IMAGES,
55 /** Yet another blob table for storing standard playlists. */
56 TBLNUM_PLAYLIST,
57 /** How many tables are in use? */
58 NUM_AFS_TABLES
59 };
60
61 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
62 [TBLNUM_AUDIO_FILES] = {.init = aft_init},
63 [TBLNUM_ATTRIBUTES] = {.init = attribute_init},
64 [TBLNUM_SCORES] = {.init = score_init},
65 [TBLNUM_MOODS] = {.init = moods_init},
66 [TBLNUM_LYRICS] = {.init = lyrics_init},
67 [TBLNUM_IMAGES] = {.init = images_init},
68 [TBLNUM_PLAYLIST] = {.init = playlists_init},
69 };
70
71 struct command_task {
72 /** The file descriptor for the local socket. */
73 int fd;
74 /**
75 * Value sent by the command handlers to identify themselves as
76 * children of the running para_server.
77 */
78 uint32_t cookie;
79 /** The associated task structure. */
80 struct task task;
81 };
82
83 extern int mmd_mutex;
84 extern struct misc_meta_data *mmd;
85
86 static int server_socket;
87 static struct command_task command_task_struct;
88 static struct signal_task signal_task_struct;
89
90 static enum play_mode current_play_mode;
91 static char *current_mop; /* mode or playlist specifier. NULL means dummy mooe */
92
93 /**
94 * A random number used to "authenticate" the connection.
95 *
96 * para_server picks this number by random before forking the afs process. The
97 * command handlers write this number together with the id of the shared memory
98 * area containing the query. This way, a malicious local user has to know this
99 * number to be able to cause the afs process to crash by sending fake queries.
100 */
101 extern uint32_t afs_socket_cookie;
102
103 /**
104 * Struct to let command handlers execute a callback in afs context.
105 *
106 * Commands that need to change the state of afs can't change the relevant data
107 * structures directly because commands are executed in a child process, i.e.
108 * they get their own virtual address space.
109 *
110 * This structure is used by \p send_callback_request() (executed from handler
111 * context) in order to let the afs process call the specified function. An
112 * instance of that structure is written to a shared memory area together with
113 * the arguments to the callback function. The identifier of the shared memory
114 * area is written to the command socket.
115 *
116 * The afs process accepts connections on the command socket and reads the
117 * shared memory id, attaches the corresponing area, calls the given handler to
118 * perform the desired action and to optionally compute a result.
119 *
120 * The result and a \p callback_result structure is then written to another
121 * shared memory area. The identifier for that area is written to the handler's
122 * command socket, so that the handler process can read the id, attach the
123 * shared memory area and use the result.
124 *
125 * \sa struct callback_result.
126 */
127 struct callback_query {
128 /** The function to be called. */
129 callback_function *handler;
130 /** The number of bytes of the query */
131 size_t query_size;
132 };
133
134 /**
135 * Structure embedded in the result of a callback.
136 *
137 * If the callback produced a result, an instance of that structure is embeeded
138 * into the shared memory area holding the result, mainly to let the command
139 * handler know the size of the result.
140 *
141 * \sa struct callback_query.
142 */
143 struct callback_result {
144 /** The number of bytes of the result. */
145 size_t result_size;
146 };
147
148 static int dispatch_result(int result_shmid, callback_result_handler *handler,
149 void *private_result_data)
150 {
151 struct osl_object result;
152 void *result_shm;
153 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
154 struct callback_result *cr = result_shm;
155
156 if (ret < 0) {
157 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
158 return ret;
159 }
160 result.size = cr->result_size;
161 result.data = result_shm + sizeof(*cr);
162 if (result.size) {
163 assert(handler);
164 ret = handler(&result, private_result_data);
165 if (ret < 0)
166 PARA_NOTICE_LOG("result handler error: %s\n",
167 para_strerror(-ret));
168 }
169 ret2 = shm_detach(result_shm);
170 if (ret2 < 0) {
171 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
172 if (ret >= 0)
173 ret = ret2;
174 }
175 return ret;
176 }
177
178 /**
179 * Ask the afs process to call a given function.
180 *
181 * \param f The function to be called.
182 * \param query Pointer to arbitrary data for the callback.
183 * \param result_handler Called for each shm area sent by the callback.
184 * \param private_result_data Passed verbatim to \a result_handler.
185 *
186 * This function creates a socket for communication with the afs process and a
187 * shared memory area (sma) to which the buffer pointed to by \a query is
188 * copied. It then notifies the afs process that the callback function \a f
189 * should be executed by sending the shared memory identifier (shmid) to the
190 * socket.
191
192 * If the callback produces a result, it sends any number of shared memory
193 * identifiers back via the socket. For each such identifier received, \a
194 * result_handler is called. The contents of the sma identified by the received
195 * shmid are passed to that function as an osl object. The private_result_data
196 * pointer is passed as the second argument to \a result_handler.
197 *
198 * \return Standard.
199 *
200 * \sa send_option_arg_callback_request(), send_standard_callback_request().
201 */
202 int send_callback_request(callback_function *f, struct osl_object *query,
203 callback_result_handler *result_handler,
204 void *private_result_data)
205 {
206 struct callback_query *cq;
207 int ret, fd = -1, query_shmid, result_shmid;
208 void *query_shm;
209 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
210 size_t query_shm_size = sizeof(*cq);
211 int dispatch_error = 0;
212
213 if (query)
214 query_shm_size += query->size;
215 ret = shm_new(query_shm_size);
216 if (ret < 0)
217 return ret;
218 query_shmid = ret;
219 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
220 if (ret < 0)
221 goto out;
222 cq = query_shm;
223 cq->handler = f;
224 cq->query_size = query_shm_size - sizeof(*cq);
225
226 if (query)
227 memcpy(query_shm + sizeof(*cq), query->data, query->size);
228 ret = shm_detach(query_shm);
229 if (ret < 0)
230 goto out;
231
232 *(uint32_t *) buf = afs_socket_cookie;
233 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
234
235 ret = create_remote_socket(conf.afs_socket_arg);
236 if (ret < 0)
237 goto out;
238 fd = ret;
239 ret = send_bin_buffer(fd, buf, sizeof(buf));
240 if (ret < 0)
241 goto out;
242 /*
243 * Read all shmids from afs.
244 *
245 * Even if the dispatcher returns an error we _must_ continue to read
246 * shmids from fd so that we can destroy all shared memory areas that
247 * have been created for us by the afs process.
248 */
249 for (;;) {
250 ret = recv_bin_buffer(fd, buf, sizeof(int));
251 if (ret <= 0)
252 goto out;
253 assert(ret == sizeof(int));
254 ret = *(int *) buf;
255 assert(ret > 0);
256 result_shmid = ret;
257 if (!dispatch_error) {
258 ret = dispatch_result(result_shmid, result_handler,
259 private_result_data);
260 if (ret < 0)
261 dispatch_error = 1;
262 }
263 ret = shm_destroy(result_shmid);
264 if (ret < 0)
265 PARA_CRIT_LOG("destroy result failed: %s\n",
266 para_strerror(-ret));
267 }
268 out:
269 if (shm_destroy(query_shmid) < 0)
270 PARA_CRIT_LOG("shm destroy error\n");
271 if (fd >= 0)
272 close(fd);
273 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
274 return ret;
275 }
276
277 /**
278 * Send a callback request passing an options structure and an argument vector.
279 *
280 * \param options pointer to an arbitrary data structure.
281 * \param argc Argument count.
282 * \param argv Standard argument vector.
283 * \param f The callback function.
284 * \param result_handler See \ref send_callback_request.
285 * \param private_result_data See \ref send_callback_request.
286 *
287 * Some commands have a couple of options that are parsed in child context for
288 * syntactic correctness and are stored in a special options structure for that
289 * command. This function allows to pass such a structure together with a list
290 * of further arguments (often a list of audio files) to the parent process.
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 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
471 ret = score_delete(aft_row);
472 if (ret < 0) {
473 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
474 goto no_admissible_files;
475 }
476 goto again;
477 }
478 shmid = ret;
479 if (!write_ok(server_socket)) {
480 ret = -E_AFS_SOCKET;
481 goto destroy;
482 }
483 *(uint32_t *)buf = NEXT_AUDIO_FILE;
484 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
485 ret = pass_afd(afd.fd, buf, 8);
486 close(afd.fd);
487 if (ret >= 0)
488 return ret;
489 destroy:
490 shm_destroy(shmid);
491 return ret;
492 no_admissible_files:
493 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
494 *(uint32_t *)(buf + 4) = (uint32_t)0;
495 return send_bin_buffer(server_socket, buf, 8);
496 }
497
498 /* Never fails if arg == NULL */
499 static int activate_mood_or_playlist(char *arg, int *num_admissible)
500 {
501 enum play_mode mode;
502 int ret;
503
504 if (!arg) {
505 ret = change_current_mood(NULL); /* always successful */
506 mode = PLAY_MODE_MOOD;
507 } else {
508 if (!strncmp(arg, "p/", 2)) {
509 ret = playlist_open(arg + 2);
510 mode = PLAY_MODE_PLAYLIST;
511 } else if (!strncmp(arg, "m/", 2)) {
512 ret = change_current_mood(arg + 2);
513 mode = PLAY_MODE_MOOD;
514 } else
515 return -E_AFS_SYNTAX;
516 if (ret < 0)
517 return ret;
518 }
519 if (num_admissible)
520 *num_admissible = ret;
521 current_play_mode = mode;
522 if (arg != current_mop) {
523 free(current_mop);
524 if (arg) {
525 current_mop = para_strdup(arg);
526 mutex_lock(mmd_mutex);
527 strncpy(mmd->afs_mode_string, arg,
528 sizeof(mmd->afs_mode_string));
529 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
530 mutex_unlock(mmd_mutex);
531 } else {
532 mutex_lock(mmd_mutex);
533 strcpy(mmd->afs_mode_string, "dummy");
534 mutex_unlock(mmd_mutex);
535 current_mop = NULL;
536 }
537 }
538 return 1;
539 }
540
541 static void com_select_callback(int fd, const struct osl_object *query)
542 {
543 struct para_buffer pb = {
544 .max_size = SHMMAX,
545 .private_data = &fd,
546 .max_size_handler = pass_buffer_as_shm
547 };
548 char *arg = query->data;
549 int num_admissible, ret, ret2;
550
551 ret = clear_score_table();
552 if (ret < 0) {
553 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
554 goto out;
555 }
556 if (current_play_mode == PLAY_MODE_MOOD)
557 close_current_mood();
558 else
559 playlist_close();
560 ret = activate_mood_or_playlist(arg, &num_admissible);
561 if (ret < 0) {
562 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
563 para_strerror(-ret), current_mop?
564 current_mop : "dummy");
565 ret = activate_mood_or_playlist(current_mop, &num_admissible);
566 if (ret < 0) {
567 if (ret2 >= 0)
568 ret2 = para_printf(&pb, "failed, switching to dummy\n");
569 activate_mood_or_playlist(NULL, &num_admissible);
570 }
571 } else
572 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
573 current_mop : "dummy mood", num_admissible);
574 out:
575 if (ret2 >= 0 && pb.offset)
576 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
577 free(pb.buf);
578 }
579
580 /**
581 * Result handler for sending data to the para_client process.
582 *
583 * \param result The data to be sent.
584 * \param private Pointer to rc4 context.
585 *
586 * \return The return value of the underlying call to rc4_send_bin_buffer().
587 *
588 * \sa \ref callback_result_handler, \ref rc4_send_bin_buffer().
589 */
590 int rc4_send_result(struct osl_object *result, void *private)
591 {
592 struct rc4_context *rc4c = private;
593
594 if (!result->size)
595 return 1;
596 return rc4_send_bin_buffer(rc4c, result->data, result->size);
597 }
598
599 int com_select(struct rc4_context *rc4c, int argc, char * const * const argv)
600 {
601 struct osl_object query;
602
603 if (argc != 2)
604 return -E_AFS_SYNTAX;
605 query.data = argv[1];
606 query.size = strlen(argv[1]) + 1;
607 return send_callback_request(com_select_callback, &query,
608 &rc4_send_result, rc4c);
609 }
610
611 static void init_admissible_files(char *arg)
612 {
613 if (activate_mood_or_playlist(arg, NULL) < 0)
614 activate_mood_or_playlist(NULL, NULL); /* always successful */
615 }
616
617 static int setup_command_socket_or_die(void)
618 {
619 int ret, socket_fd;
620 char *socket_name = conf.afs_socket_arg;
621 struct sockaddr_un unix_addr;
622
623 unlink(socket_name);
624 ret = create_local_socket(socket_name, &unix_addr,
625 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
626 if (ret < 0) {
627 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
628 exit(EXIT_FAILURE);
629 }
630 socket_fd = ret;
631 if (listen(socket_fd , 5) < 0) {
632 PARA_EMERG_LOG("can not listen on socket\n");
633 exit(EXIT_FAILURE);
634 }
635 ret = mark_fd_nonblocking(socket_fd);
636 if (ret < 0) {
637 close(socket_fd);
638 return ret;
639 }
640 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
641 socket_fd);
642 return socket_fd;
643 }
644
645 static void close_afs_tables(void)
646 {
647 int i;
648 PARA_NOTICE_LOG("closing afs_tables\n");
649 for (i = 0; i < NUM_AFS_TABLES; i++)
650 afs_tables[i].close();
651 }
652
653 static char *database_dir;
654
655 static void get_database_dir(void)
656 {
657 if (!database_dir) {
658 if (conf.afs_database_dir_given)
659 database_dir = para_strdup(conf.afs_database_dir_arg);
660 else {
661 char *home = para_homedir();
662 database_dir = make_message(
663 "%s/.paraslash/afs_database-0.4", home);
664 free(home);
665 }
666 }
667 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
668 }
669
670 static int make_database_dir(void)
671 {
672 int ret;
673
674 get_database_dir();
675 ret = para_mkdir(database_dir, 0777);
676 if (ret >= 0 || is_errno(-ret, EEXIST))
677 return 1;
678 return ret;
679 }
680
681 static int open_afs_tables(void)
682 {
683 int i, ret;
684
685 get_database_dir();
686 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
687 database_dir);
688 for (i = 0; i < NUM_AFS_TABLES; i++) {
689 ret = afs_tables[i].open(database_dir);
690 if (ret >= 0)
691 continue;
692 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
693 para_strerror(-ret));
694 break;
695 }
696 if (ret >= 0)
697 return ret;
698 while (i)
699 afs_tables[--i].close();
700 return ret;
701 }
702
703 static void signal_pre_select(struct sched *s, struct task *t)
704 {
705 struct signal_task *st = container_of(t, struct signal_task, task);
706 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
707 }
708
709 static void afs_signal_post_select(struct sched *s, struct task *t)
710 {
711 struct signal_task *st = container_of(t, struct signal_task, task);
712 if (getppid() == 1) {
713 PARA_EMERG_LOG("para_server died\n");
714 goto shutdown;
715 }
716 if (!FD_ISSET(st->fd, &s->rfds))
717 return;
718 st->signum = para_next_signal();
719 if (st->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", st->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(void)
845 {
846 char buf[8];
847 int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1);
848
849 if (ret <= 0) {
850 if (!ret)
851 ret = -ERRNO_TO_PARA_ERROR(ECONNRESET);
852 goto err;
853 }
854 buf[ret] = '\0';
855 PARA_DEBUG_LOG("received: %s\n", buf);
856 ret = -E_BAD_CMD;
857 if (strcmp(buf, "new"))
858 goto err;
859 ret = open_next_audio_file();
860 err:
861 return ret;
862 }
863
864 static void execute_afs_command(int fd, uint32_t expected_cookie)
865 {
866 uint32_t cookie;
867 int query_shmid;
868 char buf[sizeof(cookie) + sizeof(query_shmid)];
869 int ret = recv_bin_buffer(fd, buf, sizeof(buf));
870
871 if (ret < 0)
872 goto err;
873 if (ret != sizeof(buf)) {
874 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
875 ret, (long unsigned) sizeof(buf));
876 return;
877 }
878 cookie = *(uint32_t *)buf;
879 if (cookie != expected_cookie) {
880 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
881 (unsigned)cookie, (unsigned)expected_cookie);
882 return;
883 }
884 query_shmid = *(int *)(buf + sizeof(cookie));
885 if (query_shmid < 0) {
886 PARA_WARNING_LOG("received invalid query shmid %d)\n",
887 query_shmid);
888 return;
889 }
890 ret = call_callback(fd, query_shmid);
891 if (ret >= 0)
892 return;
893 err:
894 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
895 }
896
897 /** Shutdown connection if query has not arrived until this many seconds. */
898 #define AFS_CLIENT_TIMEOUT 3
899
900 static void command_post_select(struct sched *s, struct task *t)
901 {
902 struct command_task *ct = container_of(t, struct command_task, task);
903 struct sockaddr_un unix_addr;
904 struct afs_client *client, *tmp;
905 int fd, ret;
906
907 if (FD_ISSET(server_socket, &s->rfds)) {
908 ret = execute_server_command();
909 if (ret < 0) {
910 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
911 sched_shutdown();
912 return;
913 }
914 }
915
916 /* Check the list of connected clients. */
917 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
918 if (FD_ISSET(client->fd, &s->rfds))
919 execute_afs_command(client->fd, ct->cookie);
920 else { /* prevent bogus connection flooding */
921 struct timeval diff;
922 tv_diff(now, &client->connect_time, &diff);
923 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
924 continue;
925 PARA_WARNING_LOG("connection timeout\n");
926 }
927 close(client->fd);
928 list_del(&client->node);
929 free(client);
930 }
931 /* Accept connections on the local socket. */
932 if (!FD_ISSET(ct->fd, &s->rfds))
933 return;
934 ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
935 if (ret < 0) {
936 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
937 return;
938 }
939 fd = ret;
940 ret = mark_fd_nonblocking(fd);
941 if (ret < 0) {
942 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
943 close(fd);
944 return;
945 }
946 client = para_malloc(sizeof(*client));
947 client->fd = fd;
948 client->connect_time = *now;
949 para_list_add(&client->node, &afs_client_list);
950 }
951
952 static void register_command_task(uint32_t cookie)
953 {
954 struct command_task *ct = &command_task_struct;
955 ct->fd = setup_command_socket_or_die();
956 ct->cookie = cookie;
957
958 ct->task.pre_select = command_pre_select;
959 ct->task.post_select = command_post_select;
960 sprintf(ct->task.status, "command task");
961 register_task(&ct->task);
962 }
963
964 /**
965 * Initialize the audio file selector process.
966 *
967 * \param cookie The value used for "authentication".
968 * \param socket_fd File descriptor used for communication with the server.
969 */
970 __noreturn void afs_init(uint32_t cookie, int socket_fd)
971 {
972 static struct sched s;
973 int i, ret;
974
975 register_signal_task();
976 INIT_LIST_HEAD(&afs_client_list);
977 for (i = 0; i < NUM_AFS_TABLES; i++)
978 afs_tables[i].init(&afs_tables[i]);
979 ret = open_afs_tables();
980 if (ret < 0)
981 goto out;
982 server_socket = socket_fd;
983 ret = mark_fd_nonblocking(server_socket);
984 if (ret < 0)
985 goto out_close;
986 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
987 server_socket, (unsigned) cookie);
988 init_admissible_files(conf.afs_initial_mode_arg);
989 register_command_task(cookie);
990 s.default_timeout.tv_sec = 0;
991 s.default_timeout.tv_usec = 999 * 1000;
992 ret = schedule(&s);
993 out_close:
994 close_afs_tables();
995 out:
996 if (ret < 0)
997 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
998 exit(EXIT_FAILURE);
999 }
1000
1001 static void create_tables_callback(int fd, const struct osl_object *query)
1002 {
1003 uint32_t table_mask = *(uint32_t *)query->data;
1004 int i, ret;
1005 char *buf;
1006
1007 close_afs_tables();
1008 for (i = 0; i < NUM_AFS_TABLES; i++) {
1009 struct afs_table *t = &afs_tables[i];
1010
1011 if (!(table_mask & (1 << i)))
1012 continue;
1013 if (!t->create)
1014 continue;
1015 ret = t->create(database_dir);
1016 if (ret < 0)
1017 goto out;
1018 }
1019 ret = open_afs_tables();
1020 out:
1021 if (ret >= 0)
1022 buf = make_message("successfully created afs table(s)\n");
1023 else
1024 buf = make_message("%s\n", para_strerror(-ret));
1025 pass_buffer_as_shm(buf, strlen(buf), &fd);
1026 free(buf);
1027 }
1028
1029 int com_init(struct rc4_context *rc4c, int argc, char * const * const argv)
1030 {
1031 int i, j, ret;
1032 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1033 struct osl_object query = {.data = &table_mask,
1034 .size = sizeof(table_mask)};
1035
1036 ret = make_database_dir();
1037 if (ret < 0)
1038 return ret;
1039 if (argc != 1) {
1040 table_mask = 0;
1041 for (i = 1; i < argc; i++) {
1042 for (j = 0; j < NUM_AFS_TABLES; j++) {
1043 struct afs_table *t = &afs_tables[j];
1044
1045 if (strcmp(argv[i], t->name))
1046 continue;
1047 table_mask |= (1 << j);
1048 break;
1049 }
1050 if (j == NUM_AFS_TABLES)
1051 return -E_BAD_TABLE_NAME;
1052 }
1053 }
1054 ret = send_callback_request(create_tables_callback, &query,
1055 rc4_send_result, rc4c);
1056 if (ret < 0)
1057 return rc4_send_va_buffer(rc4c, "%s\n", para_strerror(-ret));
1058 return ret;
1059 }
1060
1061 /**
1062 * Flags for the check command.
1063 *
1064 * \sa com_check().
1065 */
1066 enum com_check_flags {
1067 /** Check the audio file table. */
1068 CHECK_AFT = 1,
1069 /** Check the mood table. */
1070 CHECK_MOODS = 2,
1071 /** Check the playlist table. */
1072 CHECK_PLAYLISTS = 4
1073 };
1074
1075 int com_check(struct rc4_context *rc4c, int argc, char * const * const argv)
1076 {
1077 unsigned flags = 0;
1078 int i, ret;
1079
1080 for (i = 1; i < argc; i++) {
1081 const char *arg = argv[i];
1082 if (arg[0] != '-')
1083 break;
1084 if (!strcmp(arg, "--")) {
1085 i++;
1086 break;
1087 }
1088 if (!strcmp(arg, "-a")) {
1089 flags |= CHECK_AFT;
1090 continue;
1091 }
1092 if (!strcmp(arg, "-p")) {
1093 flags |= CHECK_PLAYLISTS;
1094 continue;
1095 }
1096 if (!strcmp(arg, "-m")) {
1097 flags |= CHECK_MOODS;
1098 continue;
1099 }
1100 return -E_AFS_SYNTAX;
1101 }
1102 if (i < argc)
1103 return -E_AFS_SYNTAX;
1104 if (!flags)
1105 flags = ~0U;
1106 if (flags & CHECK_AFT) {
1107 ret = send_callback_request(aft_check_callback, NULL,
1108 rc4_send_result, rc4c);
1109 if (ret < 0)
1110 return ret;
1111 }
1112 if (flags & CHECK_PLAYLISTS) {
1113 ret = send_callback_request(playlist_check_callback,
1114 NULL, rc4_send_result, rc4c);
1115 if (ret < 0)
1116 return ret;
1117 }
1118 if (flags & CHECK_MOODS) {
1119 ret = send_callback_request(mood_check_callback, NULL,
1120 rc4_send_result, rc4c);
1121 if (ret < 0)
1122 return ret;
1123 }
1124 return 1;
1125 }
1126
1127 /**
1128 * The afs event dispatcher.
1129 *
1130 * \param event Type of the event.
1131 * \param pb May be \p NULL.
1132 * \param data Type depends on \a event.
1133 *
1134 * This function calls the table handlers of all tables and passes \a pb and \a
1135 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1136 */
1137 void afs_event(enum afs_events event, struct para_buffer *pb,
1138 void *data)
1139 {
1140 int i, ret;
1141
1142 for (i = 0; i < NUM_AFS_TABLES; i++) {
1143 struct afs_table *t = &afs_tables[i];
1144 if (!t->event_handler)
1145 continue;
1146 ret = t->event_handler(event, pb, data);
1147 if (ret < 0)
1148 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1149 event, para_strerror(-ret));
1150 }
1151 }
1152
1153 int images_event_handler(__a_unused enum afs_events event,
1154 __a_unused struct para_buffer *pb, __a_unused void *data)
1155 {
1156 return 1;
1157 }
1158
1159 int lyrics_event_handler(__a_unused enum afs_events event,
1160 __a_unused struct para_buffer *pb, __a_unused void *data)
1161 {
1162 return 1;
1163 }