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