afs signal task: Switch to the alternative post select method.
[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 static void com_select_callback(int fd, const struct osl_object *query)
550 {
551 struct para_buffer pb = {
552 .max_size = shm_get_shmmax(),
553 .private_data = &(struct afs_max_size_handler_data) {
554 .fd = fd,
555 .band = SBD_OUTPUT
556 },
557 .max_size_handler = afs_max_size_handler,
558 };
559 char *arg = query->data;
560 int num_admissible, ret, ret2;
561
562 ret = clear_score_table();
563 if (ret < 0) {
564 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
565 goto out;
566 }
567 if (current_play_mode == PLAY_MODE_MOOD)
568 close_current_mood();
569 else
570 playlist_close();
571 ret = activate_mood_or_playlist(arg, &num_admissible);
572 if (ret < 0) {
573 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
574 para_strerror(-ret), current_mop?
575 current_mop : "dummy");
576 ret = activate_mood_or_playlist(current_mop, &num_admissible);
577 if (ret < 0) {
578 if (ret2 >= 0)
579 ret2 = para_printf(&pb, "failed, switching to dummy\n");
580 activate_mood_or_playlist(NULL, &num_admissible);
581 }
582 } else
583 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
584 current_mop : "dummy mood", num_admissible);
585 out:
586 if (ret2 >= 0 && pb.offset)
587 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
588 free(pb.buf);
589 }
590
591 /**
592 * Result handler for sending data to the para_client process.
593 *
594 * \param result The data to be sent.
595 * \param band The band designator.
596 * \param private Pointer to the command context.
597 *
598 * \return The return value of the underlying call to \ref command.c::send_sb.
599 *
600 * \sa \ref callback_result_handler, \ref command.c::send_sb.
601 */
602 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
603 void *private)
604 {
605 struct command_context *cc = private;
606
607 assert(cc);
608 if (!result->size)
609 return 1;
610 if (cc->use_sideband)
611 return send_sb(&cc->scc, result->data, result->size, band,
612 true);
613 return sc_send_bin_buffer(&cc->scc, result->data, result->size);
614 }
615
616 int com_select(struct command_context *cc)
617 {
618 struct osl_object query;
619
620 if (cc->argc != 2)
621 return -E_AFS_SYNTAX;
622 query.data = cc->argv[1];
623 query.size = strlen(cc->argv[1]) + 1;
624 return send_callback_request(com_select_callback, &query,
625 &afs_cb_result_handler, cc);
626 }
627
628 static void init_admissible_files(char *arg)
629 {
630 if (activate_mood_or_playlist(arg, NULL) < 0)
631 activate_mood_or_playlist(NULL, NULL); /* always successful */
632 }
633
634 static int setup_command_socket_or_die(void)
635 {
636 int ret, socket_fd;
637 char *socket_name = conf.afs_socket_arg;
638 struct sockaddr_un unix_addr;
639
640 unlink(socket_name);
641 ret = create_local_socket(socket_name, &unix_addr,
642 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
643 if (ret < 0) {
644 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
645 exit(EXIT_FAILURE);
646 }
647 socket_fd = ret;
648 if (listen(socket_fd , 5) < 0) {
649 PARA_EMERG_LOG("can not listen on socket\n");
650 exit(EXIT_FAILURE);
651 }
652 ret = mark_fd_nonblocking(socket_fd);
653 if (ret < 0) {
654 close(socket_fd);
655 return ret;
656 }
657 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
658 socket_fd);
659 return socket_fd;
660 }
661
662 static void close_afs_tables(void)
663 {
664 int i;
665 PARA_NOTICE_LOG("closing afs_tables\n");
666 for (i = 0; i < NUM_AFS_TABLES; i++)
667 afs_tables[i].close();
668 }
669
670 static char *database_dir;
671
672 static void get_database_dir(void)
673 {
674 if (!database_dir) {
675 if (conf.afs_database_dir_given)
676 database_dir = para_strdup(conf.afs_database_dir_arg);
677 else {
678 char *home = para_homedir();
679 database_dir = make_message(
680 "%s/.paraslash/afs_database-0.4", home);
681 free(home);
682 }
683 }
684 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
685 }
686
687 static int make_database_dir(void)
688 {
689 int ret;
690
691 get_database_dir();
692 ret = para_mkdir(database_dir, 0777);
693 if (ret >= 0 || is_errno(-ret, EEXIST))
694 return 1;
695 return ret;
696 }
697
698 static int open_afs_tables(void)
699 {
700 int i, ret;
701
702 get_database_dir();
703 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
704 database_dir);
705 for (i = 0; i < NUM_AFS_TABLES; i++) {
706 ret = afs_tables[i].open(database_dir);
707 if (ret >= 0)
708 continue;
709 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
710 para_strerror(-ret));
711 break;
712 }
713 if (ret >= 0)
714 return ret;
715 while (i)
716 afs_tables[--i].close();
717 return ret;
718 }
719
720 static void signal_pre_select(struct sched *s, struct task *t)
721 {
722 struct signal_task *st = container_of(t, struct signal_task, task);
723 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
724 }
725
726 static int afs_signal_post_select(struct sched *s, __a_unused struct task *t)
727 {
728 int signum, ret;
729
730 if (getppid() == 1) {
731 PARA_EMERG_LOG("para_server died\n");
732 goto shutdown;
733 }
734 signum = para_next_signal(&s->rfds);
735 if (signum == 0)
736 return 0;
737 if (signum == SIGHUP) {
738 close_afs_tables();
739 parse_config_or_die(1);
740 ret = open_afs_tables();
741 if (ret < 0)
742 return ret;
743 init_admissible_files(current_mop);
744 return 0;
745 }
746 PARA_EMERG_LOG("terminating on signal %d\n", signum);
747 shutdown:
748 task_notify_all(s, E_AFS_SIGNAL);
749 return -E_AFS_SIGNAL;
750 }
751
752 static void register_signal_task(struct sched *s)
753 {
754 struct signal_task *st = &signal_task_struct;
755
756 para_sigaction(SIGPIPE, SIG_IGN);
757 st->fd = para_signal_init();
758 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
759 para_install_sighandler(SIGINT);
760 para_install_sighandler(SIGTERM);
761 para_install_sighandler(SIGHUP);
762
763 st->task.pre_select = signal_pre_select;
764 st->task.new_post_select = afs_signal_post_select;
765 st->task.post_select = NULL;
766 sprintf(st->task.status, "signal task");
767 register_task(s, &st->task);
768 }
769
770 static struct list_head afs_client_list;
771
772 /** Describes on connected afs client. */
773 struct afs_client {
774 /** Position in the afs client list. */
775 struct list_head node;
776 /** The socket file descriptor for this client. */
777 int fd;
778 /** The time the client connected. */
779 struct timeval connect_time;
780 };
781
782 static void command_pre_select(struct sched *s, struct task *t)
783 {
784 struct command_task *ct = container_of(t, struct command_task, task);
785 struct afs_client *client;
786
787 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
788 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
789 list_for_each_entry(client, &afs_client_list, node)
790 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
791 }
792
793 /**
794 * Send data as shared memory to a file descriptor.
795 *
796 * \param fd File descriptor to send the shmid to.
797 * \param band The band designator for this data.
798 * \param buf The buffer holding the data to be sent.
799 * \param size The size of \a buf.
800 *
801 * This function creates a shared memory area large enough to hold
802 * the content given by \a buf and \a size and sends the identifier
803 * of this area to the file descriptor \a fd.
804 *
805 * It is called by the AFS max_size handler as well as directly by the AFS
806 * command callbacks to send command output to the command handlers.
807 *
808 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
809 * and positive on success.
810 */
811 int pass_buffer_as_shm(int fd, uint8_t band, char *buf, size_t size)
812 {
813 int ret, shmid;
814 void *shm;
815 struct callback_result *cr;
816
817 if (!buf || !size)
818 return 0;
819 ret = shm_new(size + sizeof(*cr));
820 if (ret < 0)
821 return ret;
822 shmid = ret;
823 ret = shm_attach(shmid, ATTACH_RW, &shm);
824 if (ret < 0)
825 goto err;
826 cr = shm;
827 cr->result_size = size;
828 cr->band = band;
829 memcpy(shm + sizeof(*cr), buf, size);
830 ret = shm_detach(shm);
831 if (ret < 0)
832 goto err;
833 ret = write_all(fd, (char *)&shmid, sizeof(int));
834 if (ret >= 0)
835 return ret;
836 err:
837 if (shm_destroy(shmid) < 0)
838 PARA_ERROR_LOG("destroy result failed\n");
839 return ret;
840 }
841
842 /*
843 * On errors, negative value is written to fd.
844 * On success: If query produced a result, the result_shmid is written to fd.
845 * Otherwise, zero is written.
846 */
847 static int call_callback(int fd, int query_shmid)
848 {
849 void *query_shm;
850 struct callback_query *cq;
851 struct osl_object query;
852 int ret;
853
854 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
855 if (ret < 0)
856 return ret;
857 cq = query_shm;
858 query.data = (char *)query_shm + sizeof(*cq);
859 query.size = cq->query_size;
860 cq->handler(fd, &query);
861 return shm_detach(query_shm);
862 }
863
864 static int execute_server_command(fd_set *rfds)
865 {
866 char buf[8];
867 size_t n;
868 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
869
870 if (ret < 0 || n == 0)
871 return ret;
872 buf[n] = '\0';
873 if (strcmp(buf, "new"))
874 return -E_BAD_CMD;
875 return open_next_audio_file();
876 }
877
878 /* returns 0 if no data available, 1 else */
879 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
880 {
881 uint32_t cookie;
882 int query_shmid;
883 char buf[sizeof(cookie) + sizeof(query_shmid)];
884 size_t n;
885 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
886
887 if (ret < 0)
888 goto err;
889 if (n == 0)
890 return 0;
891 if (n != sizeof(buf)) {
892 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
893 ret, (long unsigned) sizeof(buf));
894 return 1;
895 }
896 cookie = *(uint32_t *)buf;
897 if (cookie != expected_cookie) {
898 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
899 (unsigned)cookie, (unsigned)expected_cookie);
900 return 1;
901 }
902 query_shmid = *(int *)(buf + sizeof(cookie));
903 if (query_shmid < 0) {
904 PARA_WARNING_LOG("received invalid query shmid %d)\n",
905 query_shmid);
906 return 1;
907 }
908 ret = call_callback(fd, query_shmid);
909 if (ret >= 0)
910 return 1;
911 err:
912 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
913 return 1;
914 }
915
916 /** Shutdown connection if query has not arrived until this many seconds. */
917 #define AFS_CLIENT_TIMEOUT 3
918
919 static void command_post_select(struct sched *s, struct task *t)
920 {
921 struct command_task *ct = container_of(t, struct command_task, task);
922 struct sockaddr_un unix_addr;
923 struct afs_client *client, *tmp;
924 int fd, ret;
925
926 ret = task_get_notification(t);
927 if (ret < 0) {
928 t->error = ret;
929 return;
930 }
931 ret = execute_server_command(&s->rfds);
932 if (ret < 0) {
933 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
934 task_notify_all(s, -ret);
935 t->error = ret;
936 return;
937 }
938 /* Check the list of connected clients. */
939 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
940 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
941 if (ret == 0) { /* prevent bogus connection flooding */
942 struct timeval diff;
943 tv_diff(now, &client->connect_time, &diff);
944 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
945 continue;
946 PARA_WARNING_LOG("connection timeout\n");
947 }
948 close(client->fd);
949 list_del(&client->node);
950 free(client);
951 }
952 /* Accept connections on the local socket. */
953 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
954 if (ret < 0)
955 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
956 if (ret <= 0)
957 return;
958 ret = mark_fd_nonblocking(fd);
959 if (ret < 0) {
960 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
961 close(fd);
962 return;
963 }
964 client = para_malloc(sizeof(*client));
965 client->fd = fd;
966 client->connect_time = *now;
967 para_list_add(&client->node, &afs_client_list);
968 }
969
970 static void register_command_task(uint32_t cookie, struct sched *s)
971 {
972 struct command_task *ct = &command_task_struct;
973 ct->fd = setup_command_socket_or_die();
974 ct->cookie = cookie;
975
976 ct->task.pre_select = command_pre_select;
977 ct->task.post_select = command_post_select;
978 sprintf(ct->task.status, "afs command task");
979 register_task(s, &ct->task);
980 }
981
982 /**
983 * Initialize the audio file selector process.
984 *
985 * \param cookie The value used for "authentication".
986 * \param socket_fd File descriptor used for communication with the server.
987 */
988 __noreturn void afs_init(uint32_t cookie, int socket_fd)
989 {
990 static struct sched s;
991 int i, ret;
992
993 register_signal_task(&s);
994 INIT_LIST_HEAD(&afs_client_list);
995 for (i = 0; i < NUM_AFS_TABLES; i++)
996 afs_tables[i].init(&afs_tables[i]);
997 ret = open_afs_tables();
998 if (ret < 0)
999 goto out;
1000 server_socket = socket_fd;
1001 ret = mark_fd_nonblocking(server_socket);
1002 if (ret < 0)
1003 goto out_close;
1004 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1005 server_socket, (unsigned) cookie);
1006 init_admissible_files(conf.afs_initial_mode_arg);
1007 register_command_task(cookie, &s);
1008 s.default_timeout.tv_sec = 0;
1009 s.default_timeout.tv_usec = 999 * 1000;
1010 ret = schedule(&s);
1011 out_close:
1012 close_afs_tables();
1013 out:
1014 if (ret < 0)
1015 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1016 exit(EXIT_FAILURE);
1017 }
1018
1019 static void create_tables_callback(int fd, const struct osl_object *query)
1020 {
1021 uint32_t table_mask = *(uint32_t *)query->data;
1022 int i, ret;
1023 struct para_buffer pb = {.buf = NULL};
1024
1025 close_afs_tables();
1026 for (i = 0; i < NUM_AFS_TABLES; i++) {
1027 struct afs_table *t = &afs_tables[i];
1028
1029 if (!(table_mask & (1 << i)))
1030 continue;
1031 if (!t->create)
1032 continue;
1033 ret = t->create(database_dir);
1034 if (ret < 0)
1035 goto out;
1036 para_printf(&pb, "successfully created %s table\n", t->name);
1037 }
1038 ret = open_afs_tables();
1039 out:
1040 if (ret < 0)
1041 para_printf(&pb, "%s\n", para_strerror(-ret));
1042 if (pb.buf)
1043 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
1044 free(pb.buf);
1045 }
1046
1047 int com_init(struct command_context *cc)
1048 {
1049 int i, j, ret;
1050 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1051 struct osl_object query = {.data = &table_mask,
1052 .size = sizeof(table_mask)};
1053
1054 ret = make_database_dir();
1055 if (ret < 0)
1056 return ret;
1057 if (cc->argc != 1) {
1058 table_mask = 0;
1059 for (i = 1; i < cc->argc; i++) {
1060 for (j = 0; j < NUM_AFS_TABLES; j++) {
1061 struct afs_table *t = &afs_tables[j];
1062
1063 if (strcmp(cc->argv[i], t->name))
1064 continue;
1065 table_mask |= (1 << j);
1066 break;
1067 }
1068 if (j == NUM_AFS_TABLES)
1069 return -E_BAD_TABLE_NAME;
1070 }
1071 }
1072 ret = send_callback_request(create_tables_callback, &query,
1073 afs_cb_result_handler, cc);
1074 if (ret < 0 && !cc->use_sideband)
1075 /* ignore return value */
1076 sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(-ret));
1077 return ret;
1078 }
1079
1080 /**
1081 * Flags for the check command.
1082 *
1083 * \sa com_check().
1084 */
1085 enum com_check_flags {
1086 /** Check the audio file table. */
1087 CHECK_AFT = 1,
1088 /** Check the mood table. */
1089 CHECK_MOODS = 2,
1090 /** Check the playlist table. */
1091 CHECK_PLAYLISTS = 4
1092 };
1093
1094 int com_check(struct command_context *cc)
1095 {
1096 unsigned flags = 0;
1097 int i, ret;
1098
1099 for (i = 1; i < cc->argc; i++) {
1100 const char *arg = cc->argv[i];
1101 if (arg[0] != '-')
1102 break;
1103 if (!strcmp(arg, "--")) {
1104 i++;
1105 break;
1106 }
1107 if (!strcmp(arg, "-a")) {
1108 flags |= CHECK_AFT;
1109 continue;
1110 }
1111 if (!strcmp(arg, "-p")) {
1112 flags |= CHECK_PLAYLISTS;
1113 continue;
1114 }
1115 if (!strcmp(arg, "-m")) {
1116 flags |= CHECK_MOODS;
1117 continue;
1118 }
1119 return -E_AFS_SYNTAX;
1120 }
1121 if (i < cc->argc)
1122 return -E_AFS_SYNTAX;
1123 if (!flags)
1124 flags = ~0U;
1125 if (flags & CHECK_AFT) {
1126 ret = send_callback_request(aft_check_callback, NULL,
1127 afs_cb_result_handler, cc);
1128 if (ret < 0)
1129 return ret;
1130 }
1131 if (flags & CHECK_PLAYLISTS) {
1132 ret = send_callback_request(playlist_check_callback,
1133 NULL, afs_cb_result_handler, cc);
1134 if (ret < 0)
1135 return ret;
1136 }
1137 if (flags & CHECK_MOODS) {
1138 ret = send_callback_request(mood_check_callback, NULL,
1139 afs_cb_result_handler, cc);
1140 if (ret < 0)
1141 return ret;
1142 }
1143 return 1;
1144 }
1145
1146 /**
1147 * The afs event dispatcher.
1148 *
1149 * \param event Type of the event.
1150 * \param pb May be \p NULL.
1151 * \param data Type depends on \a event.
1152 *
1153 * This function calls the table handlers of all tables and passes \a pb and \a
1154 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1155 */
1156 void afs_event(enum afs_events event, struct para_buffer *pb,
1157 void *data)
1158 {
1159 int i, ret;
1160
1161 for (i = 0; i < NUM_AFS_TABLES; i++) {
1162 struct afs_table *t = &afs_tables[i];
1163 if (!t->event_handler)
1164 continue;
1165 ret = t->event_handler(event, pb, data);
1166 if (ret < 0)
1167 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1168 event, para_strerror(-ret));
1169 }
1170 }
1171
1172 /**
1173 * Dummy event handler for the images table.
1174 *
1175 * \param event Unused.
1176 * \param pb Unused.
1177 * \param data Unused.
1178 *
1179 * \return The images table does not honor events, so this handler always
1180 * returns success.
1181 */
1182 __a_const int images_event_handler(__a_unused enum afs_events event,
1183 __a_unused struct para_buffer *pb, __a_unused void *data)
1184 {
1185 return 1;
1186 }
1187
1188 /**
1189 * Dummy event handler for the lyrics table.
1190 *
1191 * \param event Unused.
1192 * \param pb Unused.
1193 * \param data Unused.
1194 *
1195 * \return The lyrics table does not honor events, so this handler always
1196 * returns success.
1197 */
1198 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1199 __a_unused struct para_buffer *pb, __a_unused void *data)
1200 {
1201 return 1;
1202 }