Simplify pass_buffer_as_shm().
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007-2012 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.c Paraslash's audio file selector. */
8
9 #include <regex.h>
10 #include <signal.h>
11 #include <fnmatch.h>
12 #include <osl.h>
13
14 #include "server.cmdline.h"
15 #include "para.h"
16 #include "error.h"
17 #include "crypt.h"
18 #include "string.h"
19 #include "afh.h"
20 #include "afs.h"
21 #include "server.h"
22 #include "net.h"
23 #include "ipc.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "signal.h"
27 #include "fd.h"
28 #include "mood.h"
29 #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 mooe */
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 corresponing 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 embeeded
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 };
146
147 static int dispatch_result(int result_shmid, callback_result_handler *handler,
148 void *private_result_data)
149 {
150 struct osl_object result;
151 void *result_shm;
152 int ret2, ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
153 struct callback_result *cr = result_shm;
154
155 if (ret < 0) {
156 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
157 return ret;
158 }
159 result.size = cr->result_size;
160 result.data = result_shm + sizeof(*cr);
161 if (result.size) {
162 assert(handler);
163 ret = handler(&result, private_result_data);
164 if (ret < 0)
165 PARA_NOTICE_LOG("result handler error: %s\n",
166 para_strerror(-ret));
167 }
168 ret2 = shm_detach(result_shm);
169 if (ret2 < 0) {
170 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
171 if (ret >= 0)
172 ret = ret2;
173 }
174 return ret;
175 }
176
177 /**
178 * Ask the afs process to call a given function.
179 *
180 * \param f The function to be called.
181 * \param query Pointer to arbitrary data for the callback.
182 * \param result_handler Called for each shm area sent by the callback.
183 * \param private_result_data Passed verbatim to \a result_handler.
184 *
185 * This function creates a socket for communication with the afs process and a
186 * shared memory area (sma) to which the buffer pointed to by \a query is
187 * copied. It then notifies the afs process that the callback function \a f
188 * should be executed by sending the shared memory identifier (shmid) to the
189 * socket.
190
191 * If the callback produces a result, it sends any number of shared memory
192 * identifiers back via the socket. For each such identifier received, \a
193 * result_handler is called. The contents of the sma identified by the received
194 * shmid are passed to that function as an osl object. The private_result_data
195 * pointer is passed as the second argument to \a result_handler.
196 *
197 * \return Number of shared memory areas dispatched on success, negative on errors.
198 *
199 * \sa send_option_arg_callback_request(), send_standard_callback_request().
200 */
201 int send_callback_request(callback_function *f, struct osl_object *query,
202 callback_result_handler *result_handler,
203 void *private_result_data)
204 {
205 struct callback_query *cq;
206 int ret, fd = -1, query_shmid, result_shmid;
207 void *query_shm;
208 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
209 size_t query_shm_size = sizeof(*cq);
210 int dispatch_error = 0, num_dispatched = 0;
211
212 if (query)
213 query_shm_size += query->size;
214 ret = shm_new(query_shm_size);
215 if (ret < 0)
216 return ret;
217 query_shmid = ret;
218 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
219 if (ret < 0)
220 goto out;
221 cq = query_shm;
222 cq->handler = f;
223 cq->query_size = query_shm_size - sizeof(*cq);
224
225 if (query)
226 memcpy(query_shm + sizeof(*cq), query->data, query->size);
227 ret = shm_detach(query_shm);
228 if (ret < 0)
229 goto out;
230
231 *(uint32_t *) buf = afs_socket_cookie;
232 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
233
234 ret = connect_local_socket(conf.afs_socket_arg);
235 if (ret < 0)
236 goto out;
237 fd = ret;
238 ret = write_all(fd, buf, sizeof(buf));
239 if (ret < 0)
240 goto out;
241 /*
242 * Read all shmids from afs.
243 *
244 * Even if the dispatcher returns an error we _must_ continue to read
245 * shmids from fd so that we can destroy all shared memory areas that
246 * have been created for us by the afs process.
247 */
248 for (;;) {
249 ret = recv_bin_buffer(fd, buf, sizeof(int));
250 if (ret <= 0)
251 goto out;
252 assert(ret == sizeof(int));
253 ret = *(int *) buf;
254 assert(ret > 0);
255 result_shmid = ret;
256 if (!dispatch_error) {
257 ret = dispatch_result(result_shmid, result_handler,
258 private_result_data);
259 if (ret < 0)
260 dispatch_error = 1;
261 }
262 ret = shm_destroy(result_shmid);
263 if (ret < 0)
264 PARA_CRIT_LOG("destroy result failed: %s\n",
265 para_strerror(-ret));
266 num_dispatched++;
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 < 0? ret : num_dispatched;
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 * \return The return value of the underlying call to \ref
293 * send_callback_request().
294 *
295 * \sa send_standard_callback_request(), send_callback_request().
296 */
297 int send_option_arg_callback_request(struct osl_object *options,
298 int argc, char * const * const argv, callback_function *f,
299 callback_result_handler *result_handler,
300 void *private_result_data)
301 {
302 char *p;
303 int i, ret;
304 struct osl_object query = {.size = options? options->size : 0};
305
306 for (i = 0; i < argc; i++)
307 query.size += strlen(argv[i]) + 1;
308 query.data = para_malloc(query.size);
309 p = query.data;
310 if (options) {
311 memcpy(query.data, options->data, options->size);
312 p += options->size;
313 }
314 for (i = 0; i < argc; i++) {
315 strcpy(p, argv[i]); /* OK */
316 p += strlen(argv[i]) + 1;
317 }
318 ret = send_callback_request(f, &query, result_handler,
319 private_result_data);
320 free(query.data);
321 return ret;
322 }
323
324 /**
325 * Send a callback request with an argument vector only.
326 *
327 * \param argc The same meaning as in send_option_arg_callback_request().
328 * \param argv The same meaning as in send_option_arg_callback_request().
329 * \param f The same meaning as in send_option_arg_callback_request().
330 * \param result_handler See \ref send_callback_request.
331 * \param private_result_data See \ref send_callback_request.
332 *
333 * This is similar to send_option_arg_callback_request(), but no options buffer
334 * is passed to the parent process.
335 *
336 * \return The return value of the underlying call to
337 * send_option_arg_callback_request().
338 */
339 int send_standard_callback_request(int argc, char * const * const argv,
340 callback_function *f, callback_result_handler *result_handler,
341 void *private_result_data)
342 {
343 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
344 private_result_data);
345 }
346
347 static int action_if_pattern_matches(struct osl_row *row, void *data)
348 {
349 struct pattern_match_data *pmd = data;
350 struct osl_object name_obj;
351 const char *p, *name;
352 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
353 const char *pattern_txt = (const char *)pmd->patterns.data;
354
355 if (ret < 0)
356 return ret;
357 name = (char *)name_obj.data;
358 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
359 return 1;
360 if (!pmd->patterns.size && (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING))
361 return pmd->action(pmd->table, row, name, pmd->data);
362 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
363 p += strlen(p) + 1) {
364 ret = fnmatch(p, name, pmd->fnmatch_flags);
365 if (ret == FNM_NOMATCH)
366 continue;
367 if (ret)
368 return -E_FNMATCH;
369 ret = pmd->action(pmd->table, row, name, pmd->data);
370 if (ret >= 0)
371 pmd->num_matches++;
372 return ret;
373 }
374 return 1;
375 }
376
377 /**
378 * Execute the given function for each matching row.
379 *
380 * \param pmd Describes what to match and how.
381 *
382 * \return Standard.
383 */
384 int for_each_matching_row(struct pattern_match_data *pmd)
385 {
386 if (pmd->pm_flags & PM_REVERSE_LOOP)
387 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
388 action_if_pattern_matches));
389 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
390 action_if_pattern_matches));
391 }
392
393 /**
394 * Compare two osl objects of string type.
395 *
396 * \param obj1 Pointer to the first object.
397 * \param obj2 Pointer to the second object.
398 *
399 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
400 * are taken into account.
401 *
402 * \return It returns an integer less than, equal to, or greater than zero if
403 * \a obj1 is found, respectively, to be less than, to match, or be greater than
404 * obj2.
405 *
406 * \sa strcmp(3), strncmp(3), osl_compare_func.
407 */
408 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
409 {
410 const char *str1 = (const char *)obj1->data;
411 const char *str2 = (const char *)obj2->data;
412 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
413 }
414
415 static int pass_afd(int fd, char *buf, size_t size)
416 {
417 struct msghdr msg = {.msg_iov = NULL};
418 struct cmsghdr *cmsg;
419 char control[255];
420 int ret;
421 struct iovec iov;
422
423 iov.iov_base = buf;
424 iov.iov_len = size;
425
426 msg.msg_iov = &iov;
427 msg.msg_iovlen = 1;
428
429 msg.msg_control = control;
430 msg.msg_controllen = sizeof(control);
431
432 cmsg = CMSG_FIRSTHDR(&msg);
433 cmsg->cmsg_level = SOL_SOCKET;
434 cmsg->cmsg_type = SCM_RIGHTS;
435 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
436 *(int *)CMSG_DATA(cmsg) = fd;
437
438 /* Sum of the length of all control messages in the buffer */
439 msg.msg_controllen = cmsg->cmsg_len;
440 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
441 ret = sendmsg(server_socket, &msg, 0);
442 if (ret < 0) {
443 ret = -ERRNO_TO_PARA_ERROR(errno);
444 return ret;
445 }
446 return 1;
447 }
448
449 /**
450 * Open the audio file with highest score.
451 *
452 * This stores all information for streaming the "best" audio file in a shared
453 * memory area. The id of that area and an open file descriptor for the next
454 * audio file are passed to the server process.
455 *
456 * \return Standard.
457 *
458 * \sa open_and_update_audio_file().
459 */
460 static int open_next_audio_file(void)
461 {
462 struct osl_row *aft_row;
463 struct audio_file_data afd;
464 int ret, shmid;
465 char buf[8];
466 long score;
467 again:
468 PARA_NOTICE_LOG("getting next audio file\n");
469 ret = score_get_best(&aft_row, &score);
470 if (ret < 0) {
471 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
472 goto no_admissible_files;
473 }
474 ret = open_and_update_audio_file(aft_row, score, &afd);
475 if (ret < 0) {
476 ret = score_delete(aft_row);
477 if (ret < 0) {
478 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
479 goto no_admissible_files;
480 }
481 goto again;
482 }
483 shmid = ret;
484 if (!write_ok(server_socket)) {
485 ret = -E_AFS_SOCKET;
486 goto destroy;
487 }
488 *(uint32_t *)buf = NEXT_AUDIO_FILE;
489 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
490 ret = pass_afd(afd.fd, buf, 8);
491 close(afd.fd);
492 if (ret >= 0)
493 return ret;
494 destroy:
495 shm_destroy(shmid);
496 return ret;
497 no_admissible_files:
498 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
499 *(uint32_t *)(buf + 4) = (uint32_t)0;
500 return write_all(server_socket, buf, 8);
501 }
502
503 /* Never fails if arg == NULL */
504 static int activate_mood_or_playlist(char *arg, int *num_admissible)
505 {
506 enum play_mode mode;
507 int ret;
508
509 if (!arg) {
510 ret = change_current_mood(NULL); /* always successful */
511 mode = PLAY_MODE_MOOD;
512 } else {
513 if (!strncmp(arg, "p/", 2)) {
514 ret = playlist_open(arg + 2);
515 mode = PLAY_MODE_PLAYLIST;
516 } else if (!strncmp(arg, "m/", 2)) {
517 ret = change_current_mood(arg + 2);
518 mode = PLAY_MODE_MOOD;
519 } else
520 return -E_AFS_SYNTAX;
521 if (ret < 0)
522 return ret;
523 }
524 if (num_admissible)
525 *num_admissible = ret;
526 current_play_mode = mode;
527 if (arg != current_mop) {
528 free(current_mop);
529 if (arg) {
530 current_mop = para_strdup(arg);
531 mutex_lock(mmd_mutex);
532 strncpy(mmd->afs_mode_string, arg,
533 sizeof(mmd->afs_mode_string));
534 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
535 mutex_unlock(mmd_mutex);
536 } else {
537 mutex_lock(mmd_mutex);
538 strcpy(mmd->afs_mode_string, "dummy");
539 mutex_unlock(mmd_mutex);
540 current_mop = NULL;
541 }
542 }
543 return 1;
544 }
545
546 static void com_select_callback(int fd, const struct osl_object *query)
547 {
548 struct para_buffer pb = {
549 .max_size = shm_get_shmmax(),
550 .private_data = &(struct afs_max_size_handler_data) {
551 .fd = fd,
552 },
553 .max_size_handler = afs_max_size_handler,
554 };
555 char *arg = query->data;
556 int num_admissible, ret, ret2;
557
558 ret = clear_score_table();
559 if (ret < 0) {
560 ret2 = para_printf(&pb, "%s\n", para_strerror(-ret));
561 goto out;
562 }
563 if (current_play_mode == PLAY_MODE_MOOD)
564 close_current_mood();
565 else
566 playlist_close();
567 ret = activate_mood_or_playlist(arg, &num_admissible);
568 if (ret < 0) {
569 ret2 = para_printf(&pb, "%s\nswitching back to %s\n",
570 para_strerror(-ret), current_mop?
571 current_mop : "dummy");
572 ret = activate_mood_or_playlist(current_mop, &num_admissible);
573 if (ret < 0) {
574 if (ret2 >= 0)
575 ret2 = para_printf(&pb, "failed, switching to dummy\n");
576 activate_mood_or_playlist(NULL, &num_admissible);
577 }
578 } else
579 ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop?
580 current_mop : "dummy mood", num_admissible);
581 out:
582 if (ret2 >= 0 && pb.offset)
583 pass_buffer_as_shm(fd, pb.buf, pb.offset);
584 free(pb.buf);
585 }
586
587 /**
588 * Result handler for sending data to the para_client process.
589 *
590 * \param result The data to be sent.
591 * \param private Pointer to the context.
592 *
593 * \return The return value of the underlying call to sc_send_bin_buffer().
594 *
595 * \sa \ref callback_result_handler, \ref sc_send_bin_buffer().
596 */
597 int afs_cb_result_handler(struct osl_object *result, void *private)
598 {
599 struct command_context *cc = private;
600 int ret;
601
602 if (!result->size)
603 return 1;
604 ret = sc_send_bin_buffer(&cc->scc, result->data, result->size);
605 if (ret < 0 || ret == result->size)
606 return ret;
607 return -E_SHORT_WRITE;
608 }
609
610 int com_select(struct command_context *cc)
611 {
612 struct osl_object query;
613
614 if (cc->argc != 2)
615 return -E_AFS_SYNTAX;
616 query.data = cc->argv[1];
617 query.size = strlen(cc->argv[1]) + 1;
618 return send_callback_request(com_select_callback, &query,
619 &afs_cb_result_handler, cc);
620 }
621
622 static void init_admissible_files(char *arg)
623 {
624 if (activate_mood_or_playlist(arg, NULL) < 0)
625 activate_mood_or_playlist(NULL, NULL); /* always successful */
626 }
627
628 static int setup_command_socket_or_die(void)
629 {
630 int ret, socket_fd;
631 char *socket_name = conf.afs_socket_arg;
632 struct sockaddr_un unix_addr;
633
634 unlink(socket_name);
635 ret = create_local_socket(socket_name, &unix_addr,
636 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
637 if (ret < 0) {
638 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
639 exit(EXIT_FAILURE);
640 }
641 socket_fd = ret;
642 if (listen(socket_fd , 5) < 0) {
643 PARA_EMERG_LOG("can not listen on socket\n");
644 exit(EXIT_FAILURE);
645 }
646 ret = mark_fd_nonblocking(socket_fd);
647 if (ret < 0) {
648 close(socket_fd);
649 return ret;
650 }
651 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
652 socket_fd);
653 return socket_fd;
654 }
655
656 static void close_afs_tables(void)
657 {
658 int i;
659 PARA_NOTICE_LOG("closing afs_tables\n");
660 for (i = 0; i < NUM_AFS_TABLES; i++)
661 afs_tables[i].close();
662 }
663
664 static char *database_dir;
665
666 static void get_database_dir(void)
667 {
668 if (!database_dir) {
669 if (conf.afs_database_dir_given)
670 database_dir = para_strdup(conf.afs_database_dir_arg);
671 else {
672 char *home = para_homedir();
673 database_dir = make_message(
674 "%s/.paraslash/afs_database-0.4", home);
675 free(home);
676 }
677 }
678 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
679 }
680
681 static int make_database_dir(void)
682 {
683 int ret;
684
685 get_database_dir();
686 ret = para_mkdir(database_dir, 0777);
687 if (ret >= 0 || is_errno(-ret, EEXIST))
688 return 1;
689 return ret;
690 }
691
692 static int open_afs_tables(void)
693 {
694 int i, ret;
695
696 get_database_dir();
697 PARA_NOTICE_LOG("opening %u osl tables in %s\n", NUM_AFS_TABLES,
698 database_dir);
699 for (i = 0; i < NUM_AFS_TABLES; i++) {
700 ret = afs_tables[i].open(database_dir);
701 if (ret >= 0)
702 continue;
703 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
704 para_strerror(-ret));
705 break;
706 }
707 if (ret >= 0)
708 return ret;
709 while (i)
710 afs_tables[--i].close();
711 return ret;
712 }
713
714 static void signal_pre_select(struct sched *s, struct task *t)
715 {
716 struct signal_task *st = container_of(t, struct signal_task, task);
717 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
718 }
719
720 static void afs_signal_post_select(struct sched *s, struct task *t)
721 {
722 int signum;
723
724 if (getppid() == 1) {
725 PARA_EMERG_LOG("para_server died\n");
726 goto shutdown;
727 }
728 signum = para_next_signal(&s->rfds);
729 if (signum == 0)
730 return;
731 if (signum == SIGHUP) {
732 close_afs_tables();
733 parse_config_or_die(1);
734 t->error = open_afs_tables();
735 if (t->error < 0)
736 return;
737 init_admissible_files(current_mop);
738 return;
739 }
740 PARA_EMERG_LOG("terminating on signal %d\n", signum);
741 shutdown:
742 sched_shutdown(s);
743 t->error = -E_AFS_SIGNAL;
744 }
745
746 static void register_signal_task(struct sched *s)
747 {
748 struct signal_task *st = &signal_task_struct;
749
750 para_sigaction(SIGPIPE, SIG_IGN);
751 st->fd = para_signal_init();
752 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
753 para_install_sighandler(SIGINT);
754 para_install_sighandler(SIGTERM);
755 para_install_sighandler(SIGHUP);
756
757 st->task.pre_select = signal_pre_select;
758 st->task.post_select = afs_signal_post_select;
759 sprintf(st->task.status, "signal task");
760 register_task(s, &st->task);
761 }
762
763 static struct list_head afs_client_list;
764
765 /** Describes on connected afs client. */
766 struct afs_client {
767 /** Position in the afs client list. */
768 struct list_head node;
769 /** The socket file descriptor for this client. */
770 int fd;
771 /** The time the client connected. */
772 struct timeval connect_time;
773 };
774
775 static void command_pre_select(struct sched *s, struct task *t)
776 {
777 struct command_task *ct = container_of(t, struct command_task, task);
778 struct afs_client *client;
779
780 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
781 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
782 list_for_each_entry(client, &afs_client_list, node)
783 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
784 }
785
786 /**
787 * Send data as shared memory to a file descriptor.
788 *
789 * \param fd File descriptor to send the shmid to.
790 * \param buf The buffer holding the data to be sent.
791 * \param size The size of \a buf.
792 *
793 * This function creates a shared memory area large enough to hold
794 * the content given by \a buf and \a size and sends the identifier
795 * of this area to the file descriptor given by \a fd_ptr.
796 *
797 * It is called by the AFS max_size handler as well as directly by the AFS
798 * command callbacks to send command output to the command handlers.
799 *
800 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
801 * and positive on success.
802 */
803 int pass_buffer_as_shm(int fd, char *buf, size_t size)
804 {
805 int ret, shmid;
806 void *shm;
807 struct callback_result *cr;
808
809 if (!buf || !size)
810 return 0;
811 ret = shm_new(size + sizeof(struct callback_result));
812 if (ret < 0)
813 return ret;
814 shmid = ret;
815 ret = shm_attach(shmid, ATTACH_RW, &shm);
816 if (ret < 0)
817 goto err;
818 cr = shm;
819 cr->result_size = size;
820 memcpy(shm + sizeof(*cr), buf, size);
821 ret = shm_detach(shm);
822 if (ret < 0)
823 goto err;
824 ret = write_all(fd, (char *)&shmid, sizeof(int));
825 if (ret >= 0)
826 return ret;
827 err:
828 if (shm_destroy(shmid) < 0)
829 PARA_ERROR_LOG("destroy result failed\n");
830 return ret;
831 }
832
833 /*
834 * On errors, negative value is written to fd.
835 * On success: If query produced a result, the result_shmid is written to fd.
836 * Otherwise, zero is written.
837 */
838 static int call_callback(int fd, int query_shmid)
839 {
840 void *query_shm;
841 struct callback_query *cq;
842 struct osl_object query;
843 int ret;
844
845 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
846 if (ret < 0)
847 return ret;
848 cq = query_shm;
849 query.data = (char *)query_shm + sizeof(*cq);
850 query.size = cq->query_size;
851 cq->handler(fd, &query);
852 return shm_detach(query_shm);
853 }
854
855 static int execute_server_command(fd_set *rfds)
856 {
857 char buf[8];
858 size_t n;
859 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
860
861 if (ret < 0 || n == 0)
862 return ret;
863 buf[n] = '\0';
864 if (strcmp(buf, "new"))
865 return -E_BAD_CMD;
866 return open_next_audio_file();
867 }
868
869 /* returns 0 if no data available, 1 else */
870 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
871 {
872 uint32_t cookie;
873 int query_shmid;
874 char buf[sizeof(cookie) + sizeof(query_shmid)];
875 size_t n;
876 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
877
878 if (ret < 0)
879 goto err;
880 if (n == 0)
881 return 0;
882 if (n != sizeof(buf)) {
883 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
884 ret, (long unsigned) sizeof(buf));
885 return 1;
886 }
887 cookie = *(uint32_t *)buf;
888 if (cookie != expected_cookie) {
889 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
890 (unsigned)cookie, (unsigned)expected_cookie);
891 return 1;
892 }
893 query_shmid = *(int *)(buf + sizeof(cookie));
894 if (query_shmid < 0) {
895 PARA_WARNING_LOG("received invalid query shmid %d)\n",
896 query_shmid);
897 return 1;
898 }
899 ret = call_callback(fd, query_shmid);
900 if (ret >= 0)
901 return 1;
902 err:
903 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
904 return 1;
905 }
906
907 /** Shutdown connection if query has not arrived until this many seconds. */
908 #define AFS_CLIENT_TIMEOUT 3
909
910 static void command_post_select(struct sched *s, struct task *t)
911 {
912 struct command_task *ct = container_of(t, struct command_task, task);
913 struct sockaddr_un unix_addr;
914 struct afs_client *client, *tmp;
915 int fd, ret;
916
917 ret = execute_server_command(&s->rfds);
918 if (ret < 0) {
919 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
920 sched_shutdown(s);
921 return;
922 }
923 /* Check the list of connected clients. */
924 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
925 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
926 if (ret == 0) { /* prevent bogus connection flooding */
927 struct timeval diff;
928 tv_diff(now, &client->connect_time, &diff);
929 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
930 continue;
931 PARA_WARNING_LOG("connection timeout\n");
932 }
933 close(client->fd);
934 list_del(&client->node);
935 free(client);
936 }
937 /* Accept connections on the local socket. */
938 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
939 if (ret < 0)
940 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
941 if (ret <= 0)
942 return;
943 ret = mark_fd_nonblocking(fd);
944 if (ret < 0) {
945 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
946 close(fd);
947 return;
948 }
949 client = para_malloc(sizeof(*client));
950 client->fd = fd;
951 client->connect_time = *now;
952 para_list_add(&client->node, &afs_client_list);
953 }
954
955 static void register_command_task(uint32_t cookie, struct sched *s)
956 {
957 struct command_task *ct = &command_task_struct;
958 ct->fd = setup_command_socket_or_die();
959 ct->cookie = cookie;
960
961 ct->task.pre_select = command_pre_select;
962 ct->task.post_select = command_post_select;
963 sprintf(ct->task.status, "afs command task");
964 register_task(s, &ct->task);
965 }
966
967 /**
968 * Initialize the audio file selector process.
969 *
970 * \param cookie The value used for "authentication".
971 * \param socket_fd File descriptor used for communication with the server.
972 */
973 __noreturn void afs_init(uint32_t cookie, int socket_fd)
974 {
975 static struct sched s;
976 int i, ret;
977
978 register_signal_task(&s);
979 INIT_LIST_HEAD(&afs_client_list);
980 for (i = 0; i < NUM_AFS_TABLES; i++)
981 afs_tables[i].init(&afs_tables[i]);
982 ret = open_afs_tables();
983 if (ret < 0)
984 goto out;
985 server_socket = socket_fd;
986 ret = mark_fd_nonblocking(server_socket);
987 if (ret < 0)
988 goto out_close;
989 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
990 server_socket, (unsigned) cookie);
991 init_admissible_files(conf.afs_initial_mode_arg);
992 register_command_task(cookie, &s);
993 s.default_timeout.tv_sec = 0;
994 s.default_timeout.tv_usec = 999 * 1000;
995 ret = schedule(&s);
996 out_close:
997 close_afs_tables();
998 out:
999 if (ret < 0)
1000 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1001 exit(EXIT_FAILURE);
1002 }
1003
1004 static void create_tables_callback(int fd, const struct osl_object *query)
1005 {
1006 uint32_t table_mask = *(uint32_t *)query->data;
1007 int i, ret;
1008 struct para_buffer pb = {.buf = NULL};
1009
1010 close_afs_tables();
1011 for (i = 0; i < NUM_AFS_TABLES; i++) {
1012 struct afs_table *t = &afs_tables[i];
1013
1014 if (!(table_mask & (1 << i)))
1015 continue;
1016 if (!t->create)
1017 continue;
1018 ret = t->create(database_dir);
1019 if (ret < 0)
1020 goto out;
1021 para_printf(&pb, "successfully created %s table\n", t->name);
1022 }
1023 ret = open_afs_tables();
1024 out:
1025 if (ret < 0)
1026 para_printf(&pb, "%s\n", para_strerror(-ret));
1027 if (pb.buf)
1028 pass_buffer_as_shm(fd, pb.buf, pb.offset);
1029 free(pb.buf);
1030 }
1031
1032 int com_init(struct command_context *cc)
1033 {
1034 int i, j, ret;
1035 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1036 struct osl_object query = {.data = &table_mask,
1037 .size = sizeof(table_mask)};
1038
1039 ret = make_database_dir();
1040 if (ret < 0)
1041 return ret;
1042 if (cc->argc != 1) {
1043 table_mask = 0;
1044 for (i = 1; i < cc->argc; i++) {
1045 for (j = 0; j < NUM_AFS_TABLES; j++) {
1046 struct afs_table *t = &afs_tables[j];
1047
1048 if (strcmp(cc->argv[i], t->name))
1049 continue;
1050 table_mask |= (1 << j);
1051 break;
1052 }
1053 if (j == NUM_AFS_TABLES)
1054 return -E_BAD_TABLE_NAME;
1055 }
1056 }
1057 ret = send_callback_request(create_tables_callback, &query,
1058 afs_cb_result_handler, cc);
1059 if (ret < 0)
1060 /* ignore return value */
1061 sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(-ret));
1062 return ret;
1063 }
1064
1065 /**
1066 * Flags for the check command.
1067 *
1068 * \sa com_check().
1069 */
1070 enum com_check_flags {
1071 /** Check the audio file table. */
1072 CHECK_AFT = 1,
1073 /** Check the mood table. */
1074 CHECK_MOODS = 2,
1075 /** Check the playlist table. */
1076 CHECK_PLAYLISTS = 4
1077 };
1078
1079 int com_check(struct command_context *cc)
1080 {
1081 unsigned flags = 0;
1082 int i, ret;
1083
1084 for (i = 1; i < cc->argc; i++) {
1085 const char *arg = cc->argv[i];
1086 if (arg[0] != '-')
1087 break;
1088 if (!strcmp(arg, "--")) {
1089 i++;
1090 break;
1091 }
1092 if (!strcmp(arg, "-a")) {
1093 flags |= CHECK_AFT;
1094 continue;
1095 }
1096 if (!strcmp(arg, "-p")) {
1097 flags |= CHECK_PLAYLISTS;
1098 continue;
1099 }
1100 if (!strcmp(arg, "-m")) {
1101 flags |= CHECK_MOODS;
1102 continue;
1103 }
1104 return -E_AFS_SYNTAX;
1105 }
1106 if (i < cc->argc)
1107 return -E_AFS_SYNTAX;
1108 if (!flags)
1109 flags = ~0U;
1110 if (flags & CHECK_AFT) {
1111 ret = send_callback_request(aft_check_callback, NULL,
1112 afs_cb_result_handler, cc);
1113 if (ret < 0)
1114 return ret;
1115 }
1116 if (flags & CHECK_PLAYLISTS) {
1117 ret = send_callback_request(playlist_check_callback,
1118 NULL, afs_cb_result_handler, cc);
1119 if (ret < 0)
1120 return ret;
1121 }
1122 if (flags & CHECK_MOODS) {
1123 ret = send_callback_request(mood_check_callback, NULL,
1124 afs_cb_result_handler, cc);
1125 if (ret < 0)
1126 return ret;
1127 }
1128 return 1;
1129 }
1130
1131 /**
1132 * The afs event dispatcher.
1133 *
1134 * \param event Type of the event.
1135 * \param pb May be \p NULL.
1136 * \param data Type depends on \a event.
1137 *
1138 * This function calls the table handlers of all tables and passes \a pb and \a
1139 * data verbatim. It's up to the handlers to interpret the \a data pointer.
1140 */
1141 void afs_event(enum afs_events event, struct para_buffer *pb,
1142 void *data)
1143 {
1144 int i, ret;
1145
1146 for (i = 0; i < NUM_AFS_TABLES; i++) {
1147 struct afs_table *t = &afs_tables[i];
1148 if (!t->event_handler)
1149 continue;
1150 ret = t->event_handler(event, pb, data);
1151 if (ret < 0)
1152 PARA_CRIT_LOG("table %s, event %d: %s\n", t->name,
1153 event, para_strerror(-ret));
1154 }
1155 }
1156
1157 /**
1158 * Dummy event handler for the images table.
1159 *
1160 * \param event Unused.
1161 * \param pb Unused.
1162 * \param data Unused.
1163 *
1164 * \return The images table does not honor events, so this handler always
1165 * returns success.
1166 */
1167 __a_const int images_event_handler(__a_unused enum afs_events event,
1168 __a_unused struct para_buffer *pb, __a_unused void *data)
1169 {
1170 return 1;
1171 }
1172
1173 /**
1174 * Dummy event handler for the lyrics table.
1175 *
1176 * \param event Unused.
1177 * \param pb Unused.
1178 * \param data Unused.
1179 *
1180 * \return The lyrics table does not honor events, so this handler always
1181 * returns success.
1182 */
1183 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1184 __a_unused struct para_buffer *pb, __a_unused void *data)
1185 {
1186 return 1;
1187 }