Merge branch 't/setatt_fnmatch'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2013 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.c Paraslash's audio file selector. */
8
9 #include <regex.h>
10 #include <signal.h>
11 #include <fnmatch.h>
12 #include <osl.h>
13
14 #include "server.cmdline.h"
15 #include "para.h"
16 #include "error.h"
17 #include "crypt.h"
18 #include "string.h"
19 #include "afh.h"
20 #include "afs.h"
21 #include "server.h"
22 #include "net.h"
23 #include "ipc.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "signal.h"
27 #include "fd.h"
28 #include "mood.h"
29 #include "sideband.h"
30 #include "command.h"
31
32 /** The osl tables used by afs. \sa blob.c. */
33 enum afs_table_num {
34 /** Contains audio file information. See aft.c. */
35 TBLNUM_AUDIO_FILES,
36 /** The table for the paraslash attributes. See attribute.c. */
37 TBLNUM_ATTRIBUTES,
38 /**
39 * Paraslash's scoring system is based on Gaussian normal
40 * distributions, and the relevant data is stored in the rbtrees of an
41 * osl table containing only volatile columns. See score.c for
42 * details.
43 */
44 TBLNUM_SCORES,
45 /**
46 * A standard blob table containing the mood definitions. For details
47 * see mood.c.
48 */
49 TBLNUM_MOODS,
50 /** A blob table containing lyrics on a per-song basis. */
51 TBLNUM_LYRICS,
52 /** Another blob table for images (for example album cover art). */
53 TBLNUM_IMAGES,
54 /** Yet another blob table for storing standard playlists. */
55 TBLNUM_PLAYLIST,
56 /** How many tables are in use? */
57 NUM_AFS_TABLES
58 };
59
60 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
61 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
62 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
63 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
64 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
65 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
66 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
67 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
68 };
69
70 struct command_task {
71 /** The file descriptor for the local socket. */
72 int fd;
73 /**
74 * Value sent by the command handlers to identify themselves as
75 * children of the running para_server.
76 */
77 uint32_t cookie;
78 /** The associated task structure. */
79 struct task task;
80 };
81
82 extern int mmd_mutex;
83 extern struct misc_meta_data *mmd;
84
85 static int server_socket;
86 static struct command_task command_task_struct;
87 static struct signal_task signal_task_struct;
88
89 static enum play_mode current_play_mode;
90 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
91
92 /**
93 * A random number used to "authenticate" the connection.
94 *
95 * para_server picks this number by random before forking the afs process. The
96 * command handlers write this number together with the id of the shared memory
97 * area containing the query. This way, a malicious local user has to know this
98 * number to be able to cause the afs process to crash by sending fake queries.
99 */
100 extern uint32_t afs_socket_cookie;
101
102 /**
103 * Struct to let command handlers execute a callback in afs context.
104 *
105 * Commands that need to change the state of afs can't change the relevant data
106 * structures directly because commands are executed in a child process, i.e.
107 * they get their own virtual address space.
108 *
109 * This structure is used by \p send_callback_request() (executed from handler
110 * context) in order to let the afs process call the specified function. An
111 * instance of that structure is written to a shared memory area together with
112 * the arguments to the callback function. The identifier of the shared memory
113 * area is written to the command socket.
114 *
115 * The afs process accepts connections on the command socket and reads the
116 * shared memory id, attaches the corresponding area, calls the given handler to
117 * perform the desired action and to optionally compute a result.
118 *
119 * The result and a \p callback_result structure is then written to another
120 * shared memory area. The identifier for that area is written to the handler's
121 * command socket, so that the handler process can read the id, attach the
122 * shared memory area and use the result.
123 *
124 * \sa struct callback_result.
125 */
126 struct callback_query {
127 /** The function to be called. */
128 callback_function *handler;
129 /** The number of bytes of the query */
130 size_t query_size;
131 };
132
133 /**
134 * Structure embedded in the result of a callback.
135 *
136 * If the callback produced a result, an instance of that structure is embedded
137 * into the shared memory area holding the result, mainly to let the command
138 * handler know the size of the result.
139 *
140 * \sa struct callback_query.
141 */
142 struct callback_result {
143 /** The number of bytes of the result. */
144 size_t result_size;
145 /** The band designator (loglevel for the result). */
146 uint8_t band;
147 };
148
149 static int dispatch_result(int result_shmid, callback_result_handler *handler,
150 void *private_result_data)
151 {
152 struct osl_object result;
153 void *result_shm;
154 /* must attach r/w as result.data might get encrypted in-place. */
155 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
156 struct callback_result *cr = result_shm;
157
158 if (ret < 0) {
159 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
160 return ret;
161 }
162 result.size = cr->result_size;
163 result.data = result_shm + sizeof(*cr);
164 if (result.size) {
165 assert(handler);
166 ret = handler(&result, cr->band, private_result_data);
167 if (ret < 0)
168 PARA_NOTICE_LOG("result handler error: %s\n",
169 para_strerror(-ret));
170 }
171 ret2 = shm_detach(result_shm);
172 if (ret2 < 0) {
173 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
174 if (ret >= 0)
175 ret = ret2;
176 }
177 return ret;
178 }
179
180 /**
181 * Ask the afs process to call a given function.
182 *
183 * \param f The function to be called.
184 * \param query Pointer to arbitrary data for the callback.
185 * \param result_handler Called for each shm area sent by the callback.
186 * \param private_result_data Passed verbatim to \a result_handler.
187 *
188 * This function creates a socket for communication with the afs process and a
189 * shared memory area (sma) to which the buffer pointed to by \a query is
190 * copied. It then notifies the afs process that the callback function \a f
191 * should be executed by sending the shared memory identifier (shmid) to the
192 * socket.
193
194 * If the callback produces a result, it sends any number of shared memory
195 * identifiers back via the socket. For each such identifier received, \a
196 * result_handler is called. The contents of the sma identified by the received
197 * shmid are passed to that function as an osl object. The private_result_data
198 * pointer is passed as the second argument to \a result_handler.
199 *
200 * \return Number of shared memory areas dispatched on success, negative on errors.
201 *
202 * \sa send_option_arg_callback_request(), send_standard_callback_request().
203 */
204 int send_callback_request(callback_function *f, struct osl_object *query,
205 callback_result_handler *result_handler,
206 void *private_result_data)
207 {
208 struct callback_query *cq;
209 int ret, fd = -1, query_shmid, result_shmid;
210 void *query_shm;
211 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
212 size_t query_shm_size = sizeof(*cq);
213 int dispatch_error = 0, num_dispatched = 0;
214
215 if (query)
216 query_shm_size += query->size;
217 ret = shm_new(query_shm_size);
218 if (ret < 0)
219 return ret;
220 query_shmid = ret;
221 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
222 if (ret < 0)
223 goto out;
224 cq = query_shm;
225 cq->handler = f;
226 cq->query_size = query_shm_size - sizeof(*cq);
227
228 if (query)
229 memcpy(query_shm + sizeof(*cq), query->data, query->size);
230 ret = shm_detach(query_shm);
231 if (ret < 0)
232 goto out;
233
234 *(uint32_t *) buf = afs_socket_cookie;
235 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
236
237 ret = connect_local_socket(conf.afs_socket_arg);
238 if (ret < 0)
239 goto out;
240 fd = ret;
241 ret = write_all(fd, buf, sizeof(buf));
242 if (ret < 0)
243 goto out;
244 /*
245 * Read all shmids from afs.
246 *
247 * Even if the dispatcher returns an error we _must_ continue to read
248 * shmids from fd so that we can destroy all shared memory areas that
249 * have been created for us by the afs process.
250 */
251 for (;;) {
252 ret = recv_bin_buffer(fd, buf, sizeof(int));
253 if (ret <= 0)
254 goto out;
255 assert(ret == sizeof(int));
256 ret = *(int *) buf;
257 assert(ret > 0);
258 result_shmid = ret;
259 if (!dispatch_error) {
260 ret = dispatch_result(result_shmid, result_handler,
261 private_result_data);
262 if (ret < 0)
263 dispatch_error = 1;
264 }
265 ret = shm_destroy(result_shmid);
266 if (ret < 0)
267 PARA_CRIT_LOG("destroy result failed: %s\n",
268 para_strerror(-ret));
269 num_dispatched++;
270 }
271 out:
272 if (shm_destroy(query_shmid) < 0)
273 PARA_CRIT_LOG("shm destroy error\n");
274 if (fd >= 0)
275 close(fd);
276 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
277 return ret < 0? ret : num_dispatched;
278 }
279
280 /**
281 * Send a callback request passing an options structure and an argument vector.
282 *
283 * \param options pointer to an arbitrary data structure.
284 * \param argc Argument count.
285 * \param argv Standard argument vector.
286 * \param f The callback function.
287 * \param result_handler See \ref send_callback_request.
288 * \param private_result_data See \ref send_callback_request.
289 *
290 * Some commands have a couple of options that are parsed in child context for
291 * syntactic correctness and are stored in a special options structure for that
292 * command. This function allows to pass such a structure together with a list
293 * of further arguments (often a list of audio files) to the parent process.
294 *
295 * \return The return value of the underlying call to \ref
296 * send_callback_request().
297 *
298 * \sa send_standard_callback_request(), send_callback_request().
299 */
300 int send_option_arg_callback_request(struct osl_object *options,
301 int argc, char * const * const argv, callback_function *f,
302 callback_result_handler *result_handler,
303 void *private_result_data)
304 {
305 char *p;
306 int i, ret;
307 struct osl_object query = {.size = options? options->size : 0};
308
309 for (i = 0; i < argc; i++)
310 query.size += strlen(argv[i]) + 1;
311 query.data = para_malloc(query.size);
312 p = query.data;
313 if (options) {
314 memcpy(query.data, options->data, options->size);
315 p += options->size;
316 }
317 for (i = 0; i < argc; i++) {
318 strcpy(p, argv[i]); /* OK */
319 p += strlen(argv[i]) + 1;
320 }
321 ret = send_callback_request(f, &query, result_handler,
322 private_result_data);
323 free(query.data);
324 return ret;
325 }
326
327 /**
328 * Send a callback request with an argument vector only.
329 *
330 * \param argc The same meaning as in send_option_arg_callback_request().
331 * \param argv The same meaning as in send_option_arg_callback_request().
332 * \param f The same meaning as in send_option_arg_callback_request().
333 * \param result_handler See \ref send_callback_request.
334 * \param private_result_data See \ref send_callback_request.
335 *
336 * This is similar to send_option_arg_callback_request(), but no options buffer
337 * is passed to the parent process.
338 *
339 * \return The return value of the underlying call to
340 * send_option_arg_callback_request().
341 */
342 int send_standard_callback_request(int argc, char * const * const argv,
343 callback_function *f, callback_result_handler *result_handler,
344 void *private_result_data)
345 {
346 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
347 private_result_data);
348 }
349
350 static int action_if_pattern_matches(struct osl_row *row, void *data)
351 {
352 struct pattern_match_data *pmd = data;
353 struct osl_object name_obj;
354 const char *p, *name;
355 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
356 const char *pattern_txt = (const char *)pmd->patterns.data;
357
358 if (ret < 0)
359 return ret;
360 name = (char *)name_obj.data;
361 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
362 return 1;
363 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
364 return pmd->action(pmd->table, row, name, pmd->data);
365 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
366 p += strlen(p) + 1) {
367 ret = fnmatch(p, name, pmd->fnmatch_flags);
368 if (ret == FNM_NOMATCH)
369 continue;
370 if (ret)
371 return -E_FNMATCH;
372 ret = pmd->action(pmd->table, row, name, pmd->data);
373 if (ret >= 0)
374 pmd->num_matches++;
375 return ret;
376 }
377 return 1;
378 }
379
380 /**
381 * Execute the given function for each matching row.
382 *
383 * \param pmd Describes what to match and how.
384 *
385 * \return Standard.
386 */
387 int for_each_matching_row(struct pattern_match_data *pmd)
388 {
389 if (pmd->pm_flags & PM_REVERSE_LOOP)
390 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
391 action_if_pattern_matches));
392 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
393 action_if_pattern_matches));
394 }
395
396 /**
397 * Compare two osl objects of string type.
398 *
399 * \param obj1 Pointer to the first object.
400 * \param obj2 Pointer to the second object.
401 *
402 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
403 * are taken into account.
404 *
405 * \return It returns an integer less than, equal to, or greater than zero if
406 * \a obj1 is found, respectively, to be less than, to match, or be greater than
407 * obj2.
408 *
409 * \sa strcmp(3), strncmp(3), osl_compare_func.
410 */
411 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
412 {
413 const char *str1 = (const char *)obj1->data;
414 const char *str2 = (const char *)obj2->data;
415 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
416 }
417
418 static int pass_afd(int fd, char *buf, size_t size)
419 {
420 struct msghdr msg = {.msg_iov = NULL};
421 struct cmsghdr *cmsg;
422 char control[255];
423 int ret;
424 struct iovec iov;
425
426 iov.iov_base = buf;
427 iov.iov_len = size;
428
429 msg.msg_iov = &iov;
430 msg.msg_iovlen = 1;
431
432 msg.msg_control = control;
433 msg.msg_controllen = sizeof(control);
434
435 cmsg = CMSG_FIRSTHDR(&msg);
436 cmsg->cmsg_level = SOL_SOCKET;
437 cmsg->cmsg_type = SCM_RIGHTS;
438 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
439 *(int *)CMSG_DATA(cmsg) = fd;
440
441 /* Sum of the length of all control messages in the buffer */
442 msg.msg_controllen = cmsg->cmsg_len;
443 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
444 ret = sendmsg(server_socket, &msg, 0);
445 if (ret < 0) {
446 ret = -ERRNO_TO_PARA_ERROR(errno);
447 return ret;
448 }
449 return 1;
450 }
451
452 /**
453 * Open the audio file with highest score.
454 *
455 * This stores all information for streaming the "best" audio file in a shared
456 * memory area. The id of that area and an open file descriptor for the next
457 * audio file are passed to the server process.
458 *
459 * \return Standard.
460 *
461 * \sa open_and_update_audio_file().
462 */
463 static int open_next_audio_file(void)
464 {
465 struct osl_row *aft_row;
466 struct audio_file_data afd;
467 int ret, shmid;
468 char buf[8];
469 long score;
470 again:
471 PARA_NOTICE_LOG("getting next audio file\n");
472 ret = score_get_best(&aft_row, &score);
473 if (ret < 0) {
474 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
475 goto no_admissible_files;
476 }
477 ret = open_and_update_audio_file(aft_row, score, &afd);
478 if (ret < 0) {
479 ret = score_delete(aft_row);
480 if (ret < 0) {
481 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
482 goto no_admissible_files;
483 }
484 goto again;
485 }
486 shmid = ret;
487 if (!write_ok(server_socket)) {
488 ret = -E_AFS_SOCKET;
489 goto destroy;
490 }
491 *(uint32_t *)buf = NEXT_AUDIO_FILE;
492 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
493 ret = pass_afd(afd.fd, buf, 8);
494 close(afd.fd);
495 if (ret >= 0)
496 return ret;
497 destroy:
498 shm_destroy(shmid);
499 return ret;
500 no_admissible_files:
501 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
502 *(uint32_t *)(buf + 4) = (uint32_t)0;
503 return write_all(server_socket, buf, 8);
504 }
505
506 /* Never fails if arg == NULL */
507 static int activate_mood_or_playlist(char *arg, int *num_admissible)
508 {
509 enum play_mode mode;
510 int ret;
511
512 if (!arg) {
513 ret = change_current_mood(NULL); /* always successful */
514 mode = PLAY_MODE_MOOD;
515 } else {
516 if (!strncmp(arg, "p/", 2)) {
517 ret = playlist_open(arg + 2);
518 mode = PLAY_MODE_PLAYLIST;
519 } else if (!strncmp(arg, "m/", 2)) {
520 ret = change_current_mood(arg + 2);
521 mode = PLAY_MODE_MOOD;
522 } else
523 return -E_AFS_SYNTAX;
524 if (ret < 0)
525 return ret;
526 }
527 if (num_admissible)
528 *num_admissible = ret;
529 current_play_mode = mode;
530 if (arg != current_mop) {
531 free(current_mop);
532 if (arg) {
533 current_mop = para_strdup(arg);
534 mutex_lock(mmd_mutex);
535 strncpy(mmd->afs_mode_string, arg,
536 sizeof(mmd->afs_mode_string));
537 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
538 mutex_unlock(mmd_mutex);
539 } else {
540 mutex_lock(mmd_mutex);
541 strcpy(mmd->afs_mode_string, "dummy");
542 mutex_unlock(mmd_mutex);
543 current_mop = NULL;
544 }
545 }
546 return 1;
547 }
548
549 /**
550 * Result handler for sending data to the para_client process.
551 *
552 * \param result The data to be sent.
553 * \param band The band designator.
554 * \param private Pointer to the command context.
555 *
556 * \return The return value of the underlying call to \ref command.c::send_sb.
557 *
558 * \sa \ref callback_result_handler, \ref command.c::send_sb.
559 */
560 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
561 void *private)
562 {
563 struct command_context *cc = private;
564
565 assert(cc);
566 if (!result->size)
567 return 1;
568 return send_sb(&cc->scc, result->data, result->size, band, true);
569 }
570
571 static void com_select_callback(int fd, const struct osl_object *query)
572 {
573 struct para_buffer pb = {
574 .max_size = shm_get_shmmax(),
575 .private_data = &(struct afs_max_size_handler_data) {
576 .fd = fd,
577 .band = SBD_OUTPUT
578 },
579 .max_size_handler = afs_max_size_handler,
580 };
581 char *arg = query->data;
582 int num_admissible, ret, ret2;
583
584 ret = clear_score_table();
585 if (ret < 0) {
586 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
587 goto out;
588 }
589 if (current_play_mode == PLAY_MODE_MOOD)
590 close_current_mood();
591 else
592 playlist_close();
593 ret = activate_mood_or_playlist(arg, &num_admissible);
594 if (ret < 0) {
595 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
596 para_strerror(-ret), current_mop?
597 current_mop : "dummy");
598 ret = activate_mood_or_playlist(current_mop, &num_admissible);
599 if (ret < 0) {
600 if (ret2 >= 0)
601 ret2 = para_printf(&pb, "failed, switching to dummy\n");
602 activate_mood_or_playlist(NULL, &num_admissible);
603 }
604 } else
605 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
606 current_mop : "dummy mood", num_admissible);
607 out:
608 if (ret2 >= 0 && pb.offset)
609 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
610 free(pb.buf);
611 }
612
613 int com_select(struct command_context *cc)
614 {
615 struct osl_object query;
616
617 if (cc->argc != 2)
618 return -E_AFS_SYNTAX;
619 query.data = cc->argv[1];
620 query.size = strlen(cc->argv[1]) + 1;
621 return send_callback_request(com_select_callback, &query,
622 &afs_cb_result_handler, cc);
623 }
624
625 static void init_admissible_files(char *arg)
626 {
627 if (activate_mood_or_playlist(arg, NULL) < 0)
628 activate_mood_or_playlist(NULL, NULL); /* always successful */
629 }
630
631 static int setup_command_socket_or_die(void)
632 {
633 int ret, socket_fd;
634 char *socket_name = conf.afs_socket_arg;
635 struct sockaddr_un unix_addr;
636
637 unlink(socket_name);
638 ret = create_local_socket(socket_name, &unix_addr,
639 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
640 if (ret < 0) {
641 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
642 exit(EXIT_FAILURE);
643 }
644 socket_fd = ret;
645 if (listen(socket_fd , 5) < 0) {
646 PARA_EMERG_LOG("can not listen on socket\n");
647 exit(EXIT_FAILURE);
648 }
649 ret = mark_fd_nonblocking(socket_fd);
650 if (ret < 0) {
651 close(socket_fd);
652 return ret;
653 }
654 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
655 socket_fd);
656 return socket_fd;
657 }
658
659 static void close_afs_tables(void)
660 {
661 int i;
662 PARA_NOTICE_LOG("closing afs_tables\n");
663 for (i = 0; i < NUM_AFS_TABLES; i++)
664 afs_tables[i].close();
665 }
666
667 static char *database_dir;
668
669 static void get_database_dir(void)
670 {
671 if (!database_dir) {
672 if (conf.afs_database_dir_given)
673 database_dir = para_strdup(conf.afs_database_dir_arg);
674 else {
675 char *home = para_homedir();
676 database_dir = make_message(
677 "%s/.paraslash/afs_database-0.4", home);
678 free(home);
679 }
680 }
681 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
682 }
683
684 static int make_database_dir(void)
685 {
686 int ret;
687
688 get_database_dir();
689 ret = para_mkdir(database_dir, 0777);
690 if (ret >= 0 || is_errno(-ret, EEXIST))
691 return 1;
692 return ret;
693 }
694
695 static int open_afs_tables(void)
696 {
697 int i, ret;
698
699 get_database_dir();
700 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
701 database_dir);
702 for (i = 0; i < NUM_AFS_TABLES; i++) {
703 ret = afs_tables[i].open(database_dir);
704 if (ret >= 0)
705 continue;
706 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
707 para_strerror(-ret));
708 break;
709 }
710 if (ret >= 0)
711 return ret;
712 while (i)
713 afs_tables[--i].close();
714 return ret;
715 }
716
717 static void signal_pre_select(struct sched *s, struct task *t)
718 {
719 struct signal_task *st = container_of(t, struct signal_task, task);
720 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
721 }
722
723 static int afs_signal_post_select(struct sched *s, __a_unused struct task *t)
724 {
725 int signum, ret;
726
727 if (getppid() == 1) {
728 PARA_EMERG_LOG("para_server died\n");
729 goto shutdown;
730 }
731 signum = para_next_signal(&s->rfds);
732 if (signum == 0)
733 return 0;
734 if (signum == SIGHUP) {
735 close_afs_tables();
736 parse_config_or_die(1);
737 ret = open_afs_tables();
738 if (ret < 0)
739 return ret;
740 init_admissible_files(current_mop);
741 return 0;
742 }
743 PARA_EMERG_LOG("terminating on signal %d\n", signum);
744 shutdown:
745 task_notify_all(s, E_AFS_SIGNAL);
746 return -E_AFS_SIGNAL;
747 }
748
749 static void register_signal_task(struct sched *s)
750 {
751 struct signal_task *st = &signal_task_struct;
752
753 para_sigaction(SIGPIPE, SIG_IGN);
754 st->fd = para_signal_init();
755 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
756 para_install_sighandler(SIGINT);
757 para_install_sighandler(SIGTERM);
758 para_install_sighandler(SIGHUP);
759
760 st->task.pre_select = signal_pre_select;
761 st->task.post_select = afs_signal_post_select;
762 sprintf(st->task.status, "signal task");
763 register_task(s, &st->task);
764 }
765
766 static struct list_head afs_client_list;
767
768 /** Describes on connected afs client. */
769 struct afs_client {
770 /** Position in the afs client list. */
771 struct list_head node;
772 /** The socket file descriptor for this client. */
773 int fd;
774 /** The time the client connected. */
775 struct timeval connect_time;
776 };
777
778 static void command_pre_select(struct sched *s, struct task *t)
779 {
780 struct command_task *ct = container_of(t, struct command_task, task);
781 struct afs_client *client;
782
783 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
784 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
785 list_for_each_entry(client, &afs_client_list, node)
786 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
787 }
788
789 /**
790 * Send data as shared memory to a file descriptor.
791 *
792 * \param fd File descriptor to send the shmid to.
793 * \param band The band designator for this data.
794 * \param buf The buffer holding the data to be sent.
795 * \param size The size of \a buf.
796 *
797 * This function creates a shared memory area large enough to hold
798 * the content given by \a buf and \a size and sends the identifier
799 * of this area to the file descriptor \a fd.
800 *
801 * It is called by the AFS max_size handler as well as directly by the AFS
802 * command callbacks to send command output to the command handlers.
803 *
804 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
805 * and positive on success.
806 */
807 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
808 {
809 int ret, shmid;
810 void *shm;
811 struct callback_result *cr;
812
813 if (!buf || !size)
814 return 0;
815 ret = shm_new(size + sizeof(*cr));
816 if (ret < 0)
817 return ret;
818 shmid = ret;
819 ret = shm_attach(shmid, ATTACH_RW, &shm);
820 if (ret < 0)
821 goto err;
822 cr = shm;
823 cr->result_size = size;
824 cr->band = band;
825 memcpy(shm + sizeof(*cr), buf, size);
826 ret = shm_detach(shm);
827 if (ret < 0)
828 goto err;
829 ret = write_all(fd, (char *)&shmid, sizeof(int));
830 if (ret >= 0)
831 return ret;
832 err:
833 if (shm_destroy(shmid) < 0)
834 PARA_ERROR_LOG("destroy result failed\n");
835 return ret;
836 }
837
838 /*
839 * On errors, negative value is written to fd.
840 * On success: If query produced a result, the result_shmid is written to fd.
841 * Otherwise, zero is written.
842 */
843 static int call_callback(int fd, int query_shmid)
844 {
845 void *query_shm;
846 struct callback_query *cq;
847 struct osl_object query;
848 int ret;
849
850 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
851 if (ret < 0)
852 return ret;
853 cq = query_shm;
854 query.data = (char *)query_shm + sizeof(*cq);
855 query.size = cq->query_size;
856 cq->handler(fd, &query);
857 return shm_detach(query_shm);
858 }
859
860 static int execute_server_command(fd_set *rfds)
861 {
862 char buf[8];
863 size_t n;
864 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
865
866 if (ret < 0 || n == 0)
867 return ret;
868 buf[n] = '\0';
869 if (strcmp(buf, "new"))
870 return -E_BAD_CMD;
871 return open_next_audio_file();
872 }
873
874 /* returns 0 if no data available, 1 else */
875 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
876 {
877 uint32_t cookie;
878 int query_shmid;
879 char buf[sizeof(cookie) + sizeof(query_shmid)];
880 size_t n;
881 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
882
883 if (ret < 0)
884 goto err;
885 if (n == 0)
886 return 0;
887 if (n != sizeof(buf)) {
888 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
889 ret, (long unsigned) sizeof(buf));
890 return 1;
891 }
892 cookie = *(uint32_t *)buf;
893 if (cookie != expected_cookie) {
894 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
895 (unsigned)cookie, (unsigned)expected_cookie);
896 return 1;
897 }
898 query_shmid = *(int *)(buf + sizeof(cookie));
899 if (query_shmid < 0) {
900 PARA_WARNING_LOG("received invalid query shmid %d)\n",
901 query_shmid);
902 return 1;
903 }
904 ret = call_callback(fd, query_shmid);
905 if (ret >= 0)
906 return 1;
907 err:
908 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
909 return 1;
910 }
911
912 /** Shutdown connection if query has not arrived until this many seconds. */
913 #define AFS_CLIENT_TIMEOUT 3
914
915 static int command_post_select(struct sched *s, struct task *t)
916 {
917 struct command_task *ct = container_of(t, struct command_task, task);
918 struct sockaddr_un unix_addr;
919 struct afs_client *client, *tmp;
920 int fd, ret;
921
922 ret = task_get_notification(t);
923 if (ret < 0)
924 return ret;
925 ret = execute_server_command(&s->rfds);
926 if (ret < 0) {
927 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
928 task_notify_all(s, -ret);
929 return ret;
930 }
931 /* Check the list of connected clients. */
932 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
933 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
934 if (ret == 0) { /* prevent bogus connection flooding */
935 struct timeval diff;
936 tv_diff(now, &client->connect_time, &diff);
937 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
938 continue;
939 PARA_WARNING_LOG("connection timeout\n");
940 }
941 close(client->fd);
942 list_del(&client->node);
943 free(client);
944 }
945 /* Accept connections on the local socket. */
946 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
947 if (ret < 0)
948 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
949 if (ret <= 0)
950 return 0;
951 ret = mark_fd_nonblocking(fd);
952 if (ret < 0) {
953 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
954 close(fd);
955 return 0;
956 }
957 client = para_malloc(sizeof(*client));
958 client->fd = fd;
959 client->connect_time = *now;
960 para_list_add(&client->node, &afs_client_list);
961 return 0;
962 }
963
964 static void register_command_task(uint32_t cookie, struct sched *s)
965 {
966 struct command_task *ct = &command_task_struct;
967 ct->fd = setup_command_socket_or_die();
968 ct->cookie = cookie;
969
970 ct->task.pre_select = command_pre_select;
971 ct->task.post_select = command_post_select;
972 sprintf(ct->task.status, "afs command task");
973 register_task(s, &ct->task);
974 }
975
976 /**
977 * Initialize the audio file selector process.
978 *
979 * \param cookie The value used for "authentication".
980 * \param socket_fd File descriptor used for communication with the server.
981 */
982 __noreturn void afs_init(uint32_t cookie, int socket_fd)
983 {
984 static struct sched s;
985 int i, ret;
986
987 register_signal_task(&s);
988 INIT_LIST_HEAD(&afs_client_list);
989 for (i = 0; i < NUM_AFS_TABLES; i++)
990 afs_tables[i].init(&afs_tables[i]);
991 ret = open_afs_tables();
992 if (ret < 0)
993 goto out;
994 server_socket = socket_fd;
995 ret = mark_fd_nonblocking(server_socket);
996 if (ret < 0)
997 goto out_close;
998 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
999 server_socket, (unsigned) cookie);
1000 init_admissible_files(conf.afs_initial_mode_arg);
1001 register_command_task(cookie, &s);
1002 s.default_timeout.tv_sec = 0;
1003 s.default_timeout.tv_usec = 999 * 1000;
1004 ret = schedule(&s);
1005 out_close:
1006 close_afs_tables();
1007 out:
1008 if (ret < 0)
1009 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1010 exit(EXIT_FAILURE);
1011 }
1012
1013 static void create_tables_callback(int fd, const struct osl_object *query)
1014 {
1015 uint32_t table_mask = *(uint32_t *)query->data;
1016 int i, ret;
1017 struct para_buffer pb = {.buf = NULL};
1018
1019 close_afs_tables();
1020 for (i = 0; i < NUM_AFS_TABLES; i++) {
1021 struct afs_table *t = &afs_tables[i];
1022
1023 if (!(table_mask & (1 << i)))
1024 continue;
1025 if (!t->create)
1026 continue;
1027 ret = t->create(database_dir);
1028 if (ret < 0)
1029 goto out;
1030 para_printf(&pb, "successfully created %s table\n", t->name);
1031 }
1032 ret = open_afs_tables();
1033 out:
1034 if (ret < 0)
1035 para_printf(&pb, "%s\n", para_strerror(-ret));
1036 if (pb.buf)
1037 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
1038 free(pb.buf);
1039 }
1040
1041 int com_init(struct command_context *cc)
1042 {
1043 int i, j, ret;
1044 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1045 struct osl_object query = {.data = &table_mask,
1046 .size = sizeof(table_mask)};
1047
1048 ret = make_database_dir();
1049 if (ret < 0)
1050 return ret;
1051 if (cc->argc != 1) {
1052 table_mask = 0;
1053 for (i = 1; i < cc->argc; i++) {
1054 for (j = 0; j < NUM_AFS_TABLES; j++) {
1055 struct afs_table *t = &afs_tables[j];
1056
1057 if (strcmp(cc->argv[i], t->name))
1058 continue;
1059 table_mask |= (1 << j);
1060 break;
1061 }
1062 if (j == NUM_AFS_TABLES)
1063 return -E_BAD_TABLE_NAME;
1064 }
1065 }
1066 ret = send_callback_request(create_tables_callback, &query,
1067 afs_cb_result_handler, cc);
1068 return ret;
1069 }
1070
1071 /**
1072 * Flags for the check command.
1073 *
1074 * \sa com_check().
1075 */
1076 enum com_check_flags {
1077 /** Check the audio file table. */
1078 CHECK_AFT = 1,
1079 /** Check the mood table. */
1080 CHECK_MOODS = 2,
1081 /** Check the playlist table. */
1082 CHECK_PLAYLISTS = 4
1083 };
1084
1085 int com_check(struct command_context *cc)
1086 {
1087 unsigned flags = 0;
1088 int i, ret;
1089
1090 for (i = 1; i < cc->argc; i++) {
1091 const char *arg = cc->argv[i];
1092 if (arg[0] != '-')
1093 break;
1094 if (!strcmp(arg, "--")) {
1095 i++;
1096 break;
1097 }
1098 if (!strcmp(arg, "-a")) {
1099 flags |= CHECK_AFT;
1100 continue;
1101 }
1102 if (!strcmp(arg, "-p")) {
1103 flags |= CHECK_PLAYLISTS;
1104 continue;
1105 }
1106 if (!strcmp(arg, "-m")) {
1107 flags |= CHECK_MOODS;
1108 continue;
1109 }
1110 return -E_AFS_SYNTAX;
1111 }
1112 if (i < cc->argc)
1113 return -E_AFS_SYNTAX;
1114 if (!flags)
1115 flags = ~0U;
1116 if (flags & CHECK_AFT) {
1117 ret = send_callback_request(aft_check_callback, NULL,
1118 afs_cb_result_handler, cc);
1119 if (ret < 0)
1120 return ret;
1121 }
1122 if (flags & CHECK_PLAYLISTS) {
1123 ret = send_callback_request(playlist_check_callback,
1124 NULL, afs_cb_result_handler, cc);
1125 if (ret < 0)
1126 return ret;
1127 }
1128 if (flags & CHECK_MOODS) {
1129 ret = send_callback_request(mood_check_callback, NULL,
1130 afs_cb_result_handler, cc);
1131 if (ret < 0)
1132 return ret;
1133 }
1134 return 1;
1135 }
1136
1137 /**
1138 * The afs event dispatcher.
1139 *
1140 * \param event Type of the event.
1141 * \param pb May be \p NULL.
1142 * \param data Type depends on \a event.
1143 *
1144 * This function calls the table handlers of all tables and passes \a pb and \a
1145 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1146 */
1147 void afs_event(enum afs_events event, struct para_buffer *pb,
1148 void *data)
1149 {
1150 int i, ret;
1151
1152 for (i = 0; i < NUM_AFS_TABLES; i++) {
1153 struct afs_table *t = &afs_tables[i];
1154 if (!t->event_handler)
1155 continue;
1156 ret = t->event_handler(event, pb, data);
1157 if (ret < 0)
1158 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1159 event, para_strerror(-ret));
1160 }
1161 }
1162
1163 /**
1164 * Dummy event handler for the images table.
1165 *
1166 * \param event Unused.
1167 * \param pb Unused.
1168 * \param data Unused.
1169 *
1170 * \return The images table does not honor events, so this handler always
1171 * returns success.
1172 */
1173 __a_const int images_event_handler(__a_unused enum afs_events event,
1174 __a_unused struct para_buffer *pb, __a_unused void *data)
1175 {
1176 return 1;
1177 }
1178
1179 /**
1180 * Dummy event handler for the lyrics table.
1181 *
1182 * \param event Unused.
1183 * \param pb Unused.
1184 * \param data Unused.
1185 *
1186 * \return The lyrics table does not honor events, so this handler always
1187 * returns success.
1188 */
1189 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1190 __a_unused struct para_buffer *pb, __a_unused void *data)
1191 {
1192 return 1;
1193 }