Merge branch 'refs/heads/t/simple_error_codes'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
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 <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <arpa/inet.h>
16 #include <sys/un.h>
17 #include <netdb.h>
18
19 #include "server.cmdline.h"
20 #include "para.h"
21 #include "error.h"
22 #include "crypt.h"
23 #include "string.h"
24 #include "afh.h"
25 #include "afs.h"
26 #include "server.h"
27 #include "net.h"
28 #include "ipc.h"
29 #include "list.h"
30 #include "sched.h"
31 #include "fd.h"
32 #include "signal.h"
33 #include "mood.h"
34 #include "sideband.h"
35 #include "command.h"
36
37 /** The osl tables used by afs. \sa blob.c. */
38 enum afs_table_num {
39 /** Contains audio file information. See aft.c. */
40 TBLNUM_AUDIO_FILES,
41 /** The table for the paraslash attributes. See attribute.c. */
42 TBLNUM_ATTRIBUTES,
43 /**
44 * Paraslash's scoring system is based on Gaussian normal
45 * distributions, and the relevant data is stored in the rbtrees of an
46 * osl table containing only volatile columns. See score.c for
47 * details.
48 */
49 TBLNUM_SCORES,
50 /**
51 * A standard blob table containing the mood definitions. For details
52 * see mood.c.
53 */
54 TBLNUM_MOODS,
55 /** A blob table containing lyrics on a per-song basis. */
56 TBLNUM_LYRICS,
57 /** Another blob table for images (for example album cover art). */
58 TBLNUM_IMAGES,
59 /** Yet another blob table for storing standard playlists. */
60 TBLNUM_PLAYLIST,
61 /** How many tables are in use? */
62 NUM_AFS_TABLES
63 };
64
65 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
66 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
67 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
68 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
69 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
70 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
71 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
72 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
73 };
74
75 struct command_task {
76 /** The file descriptor for the local socket. */
77 int fd;
78 /**
79 * Value sent by the command handlers to identify themselves as
80 * children of the running para_server.
81 */
82 uint32_t cookie;
83 /** The associated task structure. */
84 struct task *task;
85 };
86
87 extern int mmd_mutex;
88 extern struct misc_meta_data *mmd;
89
90 static int server_socket;
91 static struct command_task command_task_struct;
92 static struct signal_task *signal_task;
93
94 static enum play_mode current_play_mode;
95 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
96
97 /**
98 * A random number used to "authenticate" the connection.
99 *
100 * para_server picks this number by random before it forks the afs process. The
101 * command handlers know this number as well and write it to the afs socket,
102 * together with the id of the shared memory area which contains the payload of
103 * the afs command. A local process has to know this number to abuse the afs
104 * service provided by the local socket.
105 */
106 extern uint32_t afs_socket_cookie;
107
108 /**
109 * Struct to let command handlers execute a callback in afs context.
110 *
111 * Commands that need to change the state of afs can't change the relevant data
112 * structures directly because commands are executed in a child process, i.e.
113 * they get their own virtual address space.
114 *
115 * This structure is used by \p send_callback_request() (executed from handler
116 * context) in order to let the afs process call the specified function. An
117 * instance of that structure is written to a shared memory area together with
118 * the arguments to the callback function. The identifier of the shared memory
119 * area is written to the command socket.
120 *
121 * The afs process accepts connections on the command socket and reads the
122 * shared memory id, attaches the corresponding area, calls the given handler to
123 * perform the desired action and to optionally compute a result.
124 *
125 * The result and a \p callback_result structure is then written to another
126 * shared memory area. The identifier for that area is written to the handler's
127 * command socket, so that the handler process can read the id, attach the
128 * shared memory area and use the result.
129 *
130 * \sa struct callback_result.
131 */
132 struct callback_query {
133 /** The function to be called. */
134 afs_callback *handler;
135 /** The number of bytes of the query */
136 size_t query_size;
137 };
138
139 /**
140 * Structure embedded in the result of a callback.
141 *
142 * If the callback produced a result, an instance of that structure is embedded
143 * into the shared memory area holding the result, mainly to let the command
144 * handler know the size of the result.
145 *
146 * \sa struct callback_query.
147 */
148 struct callback_result {
149 /** The number of bytes of the result. */
150 size_t result_size;
151 /** The band designator (loglevel for the result). */
152 uint8_t band;
153 };
154
155 static int dispatch_result(int result_shmid, callback_result_handler *handler,
156 void *private_result_data)
157 {
158 struct osl_object result;
159 void *result_shm;
160 /* must attach r/w as result.data might get encrypted in-place. */
161 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
162 struct callback_result *cr = result_shm;
163
164 if (ret < 0) {
165 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
166 return ret;
167 }
168 result.size = cr->result_size;
169 result.data = result_shm + sizeof(*cr);
170 assert(handler);
171 ret = handler(&result, cr->band, private_result_data);
172 ret2 = shm_detach(result_shm);
173 if (ret2 < 0) {
174 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
175 if (ret >= 0)
176 ret = ret2;
177 }
178 return ret;
179 }
180
181 /**
182 * Ask the afs process to call a given function.
183 *
184 * \param f The function to be called.
185 * \param query Pointer to arbitrary data for the callback.
186 * \param result_handler Called for each shm area sent by the callback.
187 * \param private_result_data Passed verbatim to \a result_handler.
188 *
189 * This function creates a socket for communication with the afs process and a
190 * shared memory area (sma) to which the buffer pointed to by \a query is
191 * copied. It then notifies the afs process that the callback function \a f
192 * should be executed by sending the shared memory identifier (shmid) to the
193 * socket.
194 *
195 * If the callback produces a result, it sends any number of shared memory
196 * identifiers back via the socket. For each such identifier received, \a
197 * result_handler is called. The contents of the sma identified by the received
198 * shmid are passed to that function as an osl object. The private_result_data
199 * pointer is passed as the second argument to \a result_handler.
200 *
201 * \return Number of shared memory areas dispatched on success, negative on errors.
202 *
203 * \sa send_option_arg_callback_request(), send_standard_callback_request().
204 */
205 int send_callback_request(afs_callback *f, struct osl_object *query,
206 callback_result_handler *result_handler,
207 void *private_result_data)
208 {
209 struct callback_query *cq;
210 int ret, fd = -1, query_shmid, result_shmid;
211 void *query_shm;
212 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
213 size_t query_shm_size = sizeof(*cq);
214 int dispatch_error = 0, num_dispatched = 0;
215
216 if (query)
217 query_shm_size += query->size;
218 ret = shm_new(query_shm_size);
219 if (ret < 0)
220 return ret;
221 query_shmid = ret;
222 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
223 if (ret < 0)
224 goto out;
225 cq = query_shm;
226 cq->handler = f;
227 cq->query_size = query_shm_size - sizeof(*cq);
228
229 if (query)
230 memcpy(query_shm + sizeof(*cq), query->data, query->size);
231 ret = shm_detach(query_shm);
232 if (ret < 0)
233 goto out;
234
235 *(uint32_t *)buf = afs_socket_cookie;
236 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
237
238 ret = connect_local_socket(conf.afs_socket_arg);
239 if (ret < 0)
240 goto out;
241 fd = ret;
242 ret = write_all(fd, buf, sizeof(buf));
243 if (ret < 0)
244 goto out;
245 /*
246 * Read all shmids from afs.
247 *
248 * Even if the dispatcher returns an error we _must_ continue to read
249 * shmids from fd so that we can destroy all shared memory areas that
250 * have been created for us by the afs process.
251 */
252 for (;;) {
253 ret = recv_bin_buffer(fd, buf, sizeof(int));
254 if (ret <= 0)
255 goto out;
256 assert(ret == sizeof(int));
257 ret = *(int *) buf;
258 assert(ret > 0);
259 result_shmid = ret;
260 ret = dispatch_result(result_shmid, result_handler,
261 private_result_data);
262 if (ret < 0 && dispatch_error >= 0)
263 dispatch_error = ret;
264 ret = shm_destroy(result_shmid);
265 if (ret < 0)
266 PARA_CRIT_LOG("destroy result failed: %s\n",
267 para_strerror(-ret));
268 num_dispatched++;
269 }
270 out:
271 if (shm_destroy(query_shmid) < 0)
272 PARA_CRIT_LOG("shm destroy error\n");
273 if (fd >= 0)
274 close(fd);
275 if (dispatch_error < 0)
276 return dispatch_error;
277 if (ret < 0)
278 return ret;
279 return num_dispatched;
280 }
281
282 /**
283 * Send a callback request passing an options structure and an argument vector.
284 *
285 * \param options pointer to an arbitrary data structure.
286 * \param argc Argument count.
287 * \param argv Standard argument vector.
288 * \param f The callback function.
289 * \param result_handler See \ref send_callback_request.
290 * \param private_result_data See \ref send_callback_request.
291 *
292 * Some command handlers pass command-specific options to a callback, together
293 * with a list of further arguments (often a list of audio files). This
294 * function allows to pass an arbitrary structure (given as an osl object) and
295 * a usual argument vector to the specified callback.
296 *
297 * \return The return value of the underlying call to \ref
298 * send_callback_request().
299 *
300 * \sa send_standard_callback_request(), send_callback_request().
301 */
302 int send_option_arg_callback_request(struct osl_object *options,
303 int argc, char * const * const argv, afs_callback *f,
304 callback_result_handler *result_handler,
305 void *private_result_data)
306 {
307 char *p;
308 int i, ret;
309 struct osl_object query = {.size = options? options->size : 0};
310
311 for (i = 0; i < argc; i++)
312 query.size += strlen(argv[i]) + 1;
313 query.data = para_malloc(query.size);
314 p = query.data;
315 if (options) {
316 memcpy(query.data, options->data, options->size);
317 p += options->size;
318 }
319 for (i = 0; i < argc; i++) {
320 strcpy(p, argv[i]); /* OK */
321 p += strlen(argv[i]) + 1;
322 }
323 ret = send_callback_request(f, &query, result_handler,
324 private_result_data);
325 free(query.data);
326 return ret;
327 }
328
329 /**
330 * Send a callback request with an argument vector only.
331 *
332 * \param argc The same meaning as in send_option_arg_callback_request().
333 * \param argv The same meaning as in send_option_arg_callback_request().
334 * \param f The same meaning as in send_option_arg_callback_request().
335 * \param result_handler See \ref send_callback_request.
336 * \param private_result_data See \ref send_callback_request.
337 *
338 * This is similar to send_option_arg_callback_request(), but no options buffer
339 * is passed to the parent process.
340 *
341 * \return The return value of the underlying call to
342 * send_option_arg_callback_request().
343 */
344 int send_standard_callback_request(int argc, char * const * const argv,
345 afs_callback *f, callback_result_handler *result_handler,
346 void *private_result_data)
347 {
348 return send_option_arg_callback_request(NULL, argc, argv, f, result_handler,
349 private_result_data);
350 }
351
352 static int action_if_pattern_matches(struct osl_row *row, void *data)
353 {
354 struct pattern_match_data *pmd = data;
355 struct osl_object name_obj;
356 const char *p, *name;
357 int ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num, &name_obj));
358 const char *pattern_txt = (const char *)pmd->patterns.data;
359
360 if (ret < 0)
361 return ret;
362 name = (char *)name_obj.data;
363 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
364 return 1;
365 if (pmd->patterns.size == 0 &&
366 (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING)) {
367 pmd->num_matches++;
368 return pmd->action(pmd->table, row, name, pmd->data);
369 }
370 for (p = pattern_txt; p < pattern_txt + pmd->patterns.size;
371 p += strlen(p) + 1) {
372 ret = fnmatch(p, name, pmd->fnmatch_flags);
373 if (ret == FNM_NOMATCH)
374 continue;
375 if (ret)
376 return -E_FNMATCH;
377 ret = pmd->action(pmd->table, row, name, pmd->data);
378 if (ret >= 0)
379 pmd->num_matches++;
380 return ret;
381 }
382 return 1;
383 }
384
385 /**
386 * Execute the given function for each matching row.
387 *
388 * \param pmd Describes what to match and how.
389 *
390 * \return Standard.
391 */
392 int for_each_matching_row(struct pattern_match_data *pmd)
393 {
394 if (pmd->pm_flags & PM_REVERSE_LOOP)
395 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
396 action_if_pattern_matches));
397 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
398 action_if_pattern_matches));
399 }
400
401 /**
402 * Compare two osl objects of string type.
403 *
404 * \param obj1 Pointer to the first object.
405 * \param obj2 Pointer to the second object.
406 *
407 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
408 * are taken into account.
409 *
410 * \return It returns an integer less than, equal to, or greater than zero if
411 * \a obj1 is found, respectively, to be less than, to match, or be greater than
412 * obj2.
413 *
414 * \sa strcmp(3), strncmp(3), osl_compare_func.
415 */
416 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
417 {
418 const char *str1 = (const char *)obj1->data;
419 const char *str2 = (const char *)obj2->data;
420 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
421 }
422
423 static int pass_afd(int fd, char *buf, size_t size)
424 {
425 struct msghdr msg = {.msg_iov = NULL};
426 struct cmsghdr *cmsg;
427 char control[255] __a_aligned(8);
428 int ret;
429 struct iovec iov;
430
431 iov.iov_base = buf;
432 iov.iov_len = size;
433
434 msg.msg_iov = &iov;
435 msg.msg_iovlen = 1;
436
437 msg.msg_control = control;
438 msg.msg_controllen = sizeof(control);
439
440 cmsg = CMSG_FIRSTHDR(&msg);
441 cmsg->cmsg_level = SOL_SOCKET;
442 cmsg->cmsg_type = SCM_RIGHTS;
443 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
444 *(int *)CMSG_DATA(cmsg) = fd;
445
446 /* Sum of the length of all control messages in the buffer */
447 msg.msg_controllen = cmsg->cmsg_len;
448 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
449 ret = sendmsg(server_socket, &msg, 0);
450 if (ret < 0) {
451 ret = -ERRNO_TO_PARA_ERROR(errno);
452 return ret;
453 }
454 return 1;
455 }
456
457 /**
458 * Pass the fd of the next audio file to the server process.
459 *
460 * This stores all information for streaming the "best" audio file in a shared
461 * memory area. The id of that area and an open file descriptor for the next
462 * audio file are passed to the server process.
463 *
464 * \return Standard.
465 *
466 * \sa open_and_update_audio_file().
467 */
468 static int open_next_audio_file(void)
469 {
470 struct audio_file_data afd;
471 int ret, shmid;
472 char buf[8];
473
474 ret = open_and_update_audio_file(&afd);
475 if (ret < 0) {
476 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
477 goto no_admissible_files;
478 }
479 shmid = ret;
480 if (!write_ok(server_socket)) {
481 ret = -E_AFS_SOCKET;
482 goto destroy;
483 }
484 *(uint32_t *)buf = NEXT_AUDIO_FILE;
485 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
486 ret = pass_afd(afd.fd, buf, 8);
487 close(afd.fd);
488 if (ret >= 0)
489 return ret;
490 destroy:
491 shm_destroy(shmid);
492 return ret;
493 no_admissible_files:
494 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
495 *(uint32_t *)(buf + 4) = (uint32_t)0;
496 return write_all(server_socket, buf, 8);
497 }
498
499 /* Never fails if arg == NULL */
500 static int activate_mood_or_playlist(const char *arg, int *num_admissible)
501 {
502 enum play_mode mode;
503 int ret;
504
505 if (!arg) {
506 ret = change_current_mood(NULL); /* always successful */
507 mode = PLAY_MODE_MOOD;
508 } else {
509 if (!strncmp(arg, "p/", 2)) {
510 ret = playlist_open(arg + 2);
511 mode = PLAY_MODE_PLAYLIST;
512 } else if (!strncmp(arg, "m/", 2)) {
513 ret = change_current_mood(arg + 2);
514 mode = PLAY_MODE_MOOD;
515 } else
516 return -E_AFS_SYNTAX;
517 if (ret < 0)
518 return ret;
519 }
520 if (num_admissible)
521 *num_admissible = ret;
522 current_play_mode = mode;
523 if (arg != current_mop) {
524 free(current_mop);
525 if (arg) {
526 current_mop = para_strdup(arg);
527 mutex_lock(mmd_mutex);
528 strncpy(mmd->afs_mode_string, arg,
529 sizeof(mmd->afs_mode_string));
530 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
531 mutex_unlock(mmd_mutex);
532 } else {
533 mutex_lock(mmd_mutex);
534 strcpy(mmd->afs_mode_string, "dummy");
535 mutex_unlock(mmd_mutex);
536 current_mop = NULL;
537 }
538 }
539 return 1;
540 }
541
542 /**
543 * Result handler for sending data to the para_client process.
544 *
545 * \param result The data to be sent.
546 * \param band The band designator.
547 * \param private Pointer to the command context.
548 *
549 * \return The return value of the underlying call to \ref command.c::send_sb.
550 *
551 * \sa \ref callback_result_handler, \ref command.c::send_sb.
552 */
553 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
554 void *private)
555 {
556 struct command_context *cc = private;
557
558 assert(cc);
559 switch (band) {
560 case SBD_OUTPUT:
561 case SBD_DEBUG_LOG:
562 case SBD_INFO_LOG:
563 case SBD_NOTICE_LOG:
564 case SBD_WARNING_LOG:
565 case SBD_ERROR_LOG:
566 case SBD_CRIT_LOG:
567 case SBD_EMERG_LOG:
568 assert(result->size > 0);
569 return send_sb(&cc->scc, result->data, result->size, band, true);
570 case SBD_AFS_CB_FAILURE:
571 return *(int *)(result->data);
572 default:
573 return -E_BAD_BAND;
574 }
575 }
576
577 static void flush_and_free_pb(struct para_buffer *pb)
578 {
579 int ret;
580 struct afs_max_size_handler_data *amshd = pb->private_data;
581
582 if (pb->buf && pb->size > 0) {
583 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
584 pb->offset);
585 if (ret < 0)
586 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
587 }
588 free(pb->buf);
589 }
590
591 static int com_select_callback(struct afs_callback_arg *aca)
592 {
593 const char *arg = aca->query.data;
594 int num_admissible, ret;
595
596 ret = clear_score_table();
597 if (ret < 0) {
598 para_printf(&aca->pbout, "could not clear score table: %s\n",
599 para_strerror(-ret));
600 return ret;
601 }
602 if (current_play_mode == PLAY_MODE_MOOD)
603 close_current_mood();
604 else
605 playlist_close();
606 ret = activate_mood_or_playlist(arg, &num_admissible);
607 if (ret >= 0)
608 goto out;
609 /* ignore subsequent errors (but log them) */
610 para_printf(&aca->pbout, "could not activate %s\n", arg);
611 if (current_mop) {
612 int ret2;
613 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
614 ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
615 if (ret2 >= 0)
616 goto out;
617 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
618 current_mop, para_strerror(-ret2));
619 }
620 para_printf(&aca->pbout, "activating dummy mood\n");
621 activate_mood_or_playlist(NULL, &num_admissible);
622 out:
623 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
624 current_mop? current_mop : "dummy mood", num_admissible);
625 return ret;
626 }
627
628 int com_select(struct command_context *cc)
629 {
630 struct osl_object query;
631
632 if (cc->argc != 2)
633 return -E_AFS_SYNTAX;
634 query.data = cc->argv[1];
635 query.size = strlen(cc->argv[1]) + 1;
636 return send_callback_request(com_select_callback, &query,
637 &afs_cb_result_handler, cc);
638 }
639
640 static void init_admissible_files(char *arg)
641 {
642 if (activate_mood_or_playlist(arg, NULL) < 0)
643 activate_mood_or_playlist(NULL, NULL); /* always successful */
644 }
645
646 static int setup_command_socket_or_die(void)
647 {
648 int ret, socket_fd;
649 char *socket_name = conf.afs_socket_arg;
650
651 unlink(socket_name);
652 ret = create_local_socket(socket_name, 0);
653 if (ret < 0) {
654 ret = create_local_socket(socket_name,
655 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IROTH);
656 if (ret < 0) {
657 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret),
658 socket_name);
659 exit(EXIT_FAILURE);
660 }
661 }
662 socket_fd = ret;
663 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
664 socket_fd);
665 return socket_fd;
666 }
667
668 static void close_afs_tables(void)
669 {
670 int i;
671 PARA_NOTICE_LOG("closing afs_tables\n");
672 for (i = 0; i < NUM_AFS_TABLES; i++)
673 afs_tables[i].close();
674 }
675
676 static char *database_dir;
677
678 static void get_database_dir(void)
679 {
680 if (!database_dir) {
681 if (conf.afs_database_dir_given)
682 database_dir = para_strdup(conf.afs_database_dir_arg);
683 else {
684 char *home = para_homedir();
685 database_dir = make_message(
686 "%s/.paraslash/afs_database-0.4", home);
687 free(home);
688 }
689 }
690 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
691 }
692
693 static int make_database_dir(void)
694 {
695 int ret;
696
697 get_database_dir();
698 ret = para_mkdir(database_dir, 0777);
699 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
700 return 1;
701 return ret;
702 }
703
704 static int open_afs_tables(void)
705 {
706 int i, ret;
707
708 get_database_dir();
709 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
710 database_dir);
711 for (i = 0; i < NUM_AFS_TABLES; i++) {
712 ret = afs_tables[i].open(database_dir);
713 if (ret >= 0)
714 continue;
715 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
716 para_strerror(-ret));
717 break;
718 }
719 if (ret >= 0)
720 return ret;
721 while (i)
722 afs_tables[--i].close();
723 return ret;
724 }
725
726 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
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 para_sigaction(SIGPIPE, SIG_IGN);
755 signal_task = signal_init_or_die();
756 para_install_sighandler(SIGINT);
757 para_install_sighandler(SIGTERM);
758 para_install_sighandler(SIGHUP);
759
760 signal_task->task = task_register(&(struct task_info) {
761 .name = "signal",
762 .pre_select = signal_pre_select,
763 .post_select = afs_signal_post_select,
764 .context = signal_task,
765
766 }, s);
767 }
768
769 static struct list_head afs_client_list;
770
771 /** Describes one connected afs client. */
772 struct afs_client {
773 /** Position in the afs client list. */
774 struct list_head node;
775 /** The socket file descriptor for this client. */
776 int fd;
777 /** The time the client connected. */
778 struct timeval connect_time;
779 };
780
781 static void command_pre_select(struct sched *s, void *context)
782 {
783 struct command_task *ct = context;
784 struct afs_client *client;
785
786 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
787 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
788 list_for_each_entry(client, &afs_client_list, node)
789 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
790 }
791
792 /**
793 * Send data as shared memory to a file descriptor.
794 *
795 * \param fd File descriptor to send the shmid to.
796 * \param band The band designator for this data.
797 * \param buf The buffer holding the data to be sent.
798 * \param size The size of \a buf.
799 *
800 * This function creates a shared memory area large enough to hold
801 * the content given by \a buf and \a size and sends the identifier
802 * of this area to the file descriptor \a fd.
803 *
804 * It is called by the AFS max_size handler as well as directly by the AFS
805 * command callbacks to send command output to the command handlers.
806 *
807 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
808 * and positive on success.
809 */
810 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
811 {
812 int ret, shmid;
813 void *shm;
814 struct callback_result *cr;
815
816 if (size == 0)
817 assert(band != SBD_OUTPUT);
818 ret = shm_new(size + sizeof(*cr));
819 if (ret < 0)
820 return ret;
821 shmid = ret;
822 ret = shm_attach(shmid, ATTACH_RW, &shm);
823 if (ret < 0)
824 goto err;
825 cr = shm;
826 cr->result_size = size;
827 cr->band = band;
828 if (size > 0)
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 static int call_callback(int fd, int query_shmid)
843 {
844 void *query_shm;
845 struct callback_query *cq;
846 int ret, ret2;
847 struct afs_callback_arg aca = {.fd = fd};
848
849 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
850 if (ret < 0)
851 return ret;
852 cq = query_shm;
853 aca.query.data = (char *)query_shm + sizeof(*cq);
854 aca.query.size = cq->query_size;
855 aca.pbout.max_size = shm_get_shmmax();
856 aca.pbout.max_size_handler = afs_max_size_handler;
857 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
858 .fd = fd,
859 .band = SBD_OUTPUT
860 };
861 ret = cq->handler(&aca);
862 ret2 = shm_detach(query_shm);
863 if (ret2 < 0) {
864 if (ret < 0) /* ignore (but log) detach error */
865 PARA_ERROR_LOG("could not detach sma: %s\n",
866 para_strerror(-ret2));
867 else
868 ret = ret2;
869 }
870 flush_and_free_pb(&aca.pbout);
871 if (ret < 0) {
872 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
873 (const char *)&ret, sizeof(ret));
874 if (ret2 < 0)
875 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
876 para_strerror(-ret));
877 }
878 return ret;
879 }
880
881 static int execute_server_command(fd_set *rfds)
882 {
883 char buf[8];
884 size_t n;
885 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
886
887 if (ret < 0 || n == 0)
888 return ret;
889 buf[n] = '\0';
890 if (strcmp(buf, "new"))
891 return -E_BAD_CMD;
892 return open_next_audio_file();
893 }
894
895 /* returns 0 if no data available, 1 else */
896 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
897 {
898 uint32_t cookie;
899 int query_shmid;
900 char buf[sizeof(cookie) + sizeof(query_shmid)];
901 size_t n;
902 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
903
904 if (ret < 0)
905 goto err;
906 if (n == 0)
907 return 0;
908 if (n != sizeof(buf)) {
909 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
910 ret, (long unsigned) sizeof(buf));
911 return 1;
912 }
913 cookie = *(uint32_t *)buf;
914 if (cookie != expected_cookie) {
915 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
916 (unsigned)cookie, (unsigned)expected_cookie);
917 return 1;
918 }
919 query_shmid = *(int *)(buf + sizeof(cookie));
920 if (query_shmid < 0) {
921 PARA_WARNING_LOG("received invalid query shmid %d)\n",
922 query_shmid);
923 return 1;
924 }
925 ret = call_callback(fd, query_shmid);
926 if (ret >= 0)
927 return 1;
928 err:
929 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
930 return 1;
931 }
932
933 /** Shutdown connection if query has not arrived until this many seconds. */
934 #define AFS_CLIENT_TIMEOUT 3
935
936 static int command_post_select(struct sched *s, void *context)
937 {
938 struct command_task *ct = context;
939 struct sockaddr_un unix_addr;
940 struct afs_client *client, *tmp;
941 int fd, ret;
942
943 ret = task_get_notification(ct->task);
944 if (ret < 0)
945 return ret;
946 ret = execute_server_command(&s->rfds);
947 if (ret < 0) {
948 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
949 task_notify_all(s, -ret);
950 return ret;
951 }
952 /* Check the list of connected clients. */
953 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
954 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
955 if (ret == 0) { /* prevent bogus connection flooding */
956 struct timeval diff;
957 tv_diff(now, &client->connect_time, &diff);
958 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
959 continue;
960 PARA_WARNING_LOG("connection timeout\n");
961 }
962 close(client->fd);
963 list_del(&client->node);
964 free(client);
965 }
966 /* Accept connections on the local socket. */
967 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
968 if (ret < 0)
969 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
970 if (ret <= 0)
971 return 0;
972 ret = mark_fd_nonblocking(fd);
973 if (ret < 0) {
974 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
975 close(fd);
976 return 0;
977 }
978 client = para_malloc(sizeof(*client));
979 client->fd = fd;
980 client->connect_time = *now;
981 para_list_add(&client->node, &afs_client_list);
982 return 0;
983 }
984
985 static void register_command_task(uint32_t cookie, struct sched *s)
986 {
987 struct command_task *ct = &command_task_struct;
988 ct->fd = setup_command_socket_or_die();
989 ct->cookie = cookie;
990
991 ct->task = task_register(&(struct task_info) {
992 .name = "afs command",
993 .pre_select = command_pre_select,
994 .post_select = command_post_select,
995 .context = ct,
996 }, s);
997 }
998
999 /**
1000 * Initialize the audio file selector process.
1001 *
1002 * \param cookie The value used for "authentication".
1003 * \param socket_fd File descriptor used for communication with the server.
1004 */
1005 __noreturn void afs_init(uint32_t cookie, int socket_fd)
1006 {
1007 static struct sched s;
1008 int i, ret;
1009
1010 register_signal_task(&s);
1011 INIT_LIST_HEAD(&afs_client_list);
1012 for (i = 0; i < NUM_AFS_TABLES; i++)
1013 afs_tables[i].init(&afs_tables[i]);
1014 ret = open_afs_tables();
1015 if (ret < 0)
1016 goto out;
1017 server_socket = socket_fd;
1018 ret = mark_fd_nonblocking(server_socket);
1019 if (ret < 0)
1020 goto out_close;
1021 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
1022 server_socket, (unsigned) cookie);
1023 init_admissible_files(conf.afs_initial_mode_arg);
1024 register_command_task(cookie, &s);
1025 s.default_timeout.tv_sec = 0;
1026 s.default_timeout.tv_usec = 999 * 1000;
1027 ret = write(socket_fd, "\0", 1);
1028 if (ret != 1) {
1029 if (ret == 0)
1030 errno = EINVAL;
1031 ret = -ERRNO_TO_PARA_ERROR(errno);
1032 goto out_close;
1033 }
1034 ret = schedule(&s);
1035 sched_shutdown(&s);
1036 out_close:
1037 close_afs_tables();
1038 out:
1039 if (ret < 0)
1040 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1041 exit(EXIT_FAILURE);
1042 }
1043
1044 static int com_init_callback(struct afs_callback_arg *aca)
1045 {
1046 uint32_t table_mask = *(uint32_t *)aca->query.data;
1047 int i, ret;
1048
1049 close_afs_tables();
1050 for (i = 0; i < NUM_AFS_TABLES; i++) {
1051 struct afs_table *t = &afs_tables[i];
1052
1053 if (!(table_mask & (1 << i)))
1054 continue;
1055 if (!t->create)
1056 continue;
1057 ret = t->create(database_dir);
1058 if (ret < 0) {
1059 para_printf(&aca->pbout, "cannot create table %s\n",
1060 t->name);
1061 goto out;
1062 }
1063 para_printf(&aca->pbout, "successfully created %s table\n",
1064 t->name);
1065 }
1066 ret = open_afs_tables();
1067 if (ret < 0)
1068 para_printf(&aca->pbout, "cannot open afs tables\n");
1069 out:
1070 return ret;
1071 }
1072
1073 int com_init(struct command_context *cc)
1074 {
1075 int i, j, ret;
1076 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1077 struct osl_object query = {.data = &table_mask,
1078 .size = sizeof(table_mask)};
1079
1080 ret = make_database_dir();
1081 if (ret < 0)
1082 return ret;
1083 if (cc->argc != 1) {
1084 table_mask = 0;
1085 for (i = 1; i < cc->argc; i++) {
1086 for (j = 0; j < NUM_AFS_TABLES; j++) {
1087 struct afs_table *t = &afs_tables[j];
1088
1089 if (strcmp(cc->argv[i], t->name))
1090 continue;
1091 table_mask |= (1 << j);
1092 break;
1093 }
1094 if (j == NUM_AFS_TABLES)
1095 return -E_BAD_TABLE_NAME;
1096 }
1097 }
1098 return send_callback_request(com_init_callback, &query,
1099 afs_cb_result_handler, cc);
1100 }
1101
1102 /**
1103 * Flags for the check command.
1104 *
1105 * \sa com_check().
1106 */
1107 enum com_check_flags {
1108 /** Check the audio file table. */
1109 CHECK_AFT = 1,
1110 /** Check the mood table. */
1111 CHECK_MOODS = 2,
1112 /** Check the playlist table. */
1113 CHECK_PLAYLISTS = 4,
1114 /** Check the attribute table against the audio file table. */
1115 CHECK_ATTS = 8
1116 };
1117
1118 int com_check(struct command_context *cc)
1119 {
1120 unsigned flags = 0;
1121 int i, ret;
1122
1123 for (i = 1; i < cc->argc; i++) {
1124 const char *arg = cc->argv[i];
1125 if (arg[0] != '-')
1126 break;
1127 if (!strcmp(arg, "--")) {
1128 i++;
1129 break;
1130 }
1131 if (!strcmp(arg, "-a")) {
1132 flags |= CHECK_AFT;
1133 continue;
1134 }
1135 if (!strcmp(arg, "-A")) {
1136 flags |= CHECK_ATTS;
1137 continue;
1138 }
1139 if (!strcmp(arg, "-p")) {
1140 flags |= CHECK_PLAYLISTS;
1141 continue;
1142 }
1143 if (!strcmp(arg, "-m")) {
1144 flags |= CHECK_MOODS;
1145 continue;
1146 }
1147 return -E_AFS_SYNTAX;
1148 }
1149 if (i < cc->argc)
1150 return -E_AFS_SYNTAX;
1151 if (!flags)
1152 flags = ~0U;
1153 if (flags & CHECK_AFT) {
1154 ret = send_callback_request(aft_check_callback, NULL,
1155 afs_cb_result_handler, cc);
1156 if (ret < 0)
1157 return ret;
1158 }
1159 if (flags & CHECK_ATTS) {
1160 ret = send_callback_request(attribute_check_callback, NULL,
1161 afs_cb_result_handler, cc);
1162 if (ret < 0)
1163 return ret;
1164 }
1165 if (flags & CHECK_PLAYLISTS) {
1166 ret = send_callback_request(playlist_check_callback,
1167 NULL, afs_cb_result_handler, cc);
1168 if (ret < 0)
1169 return ret;
1170 }
1171 if (flags & CHECK_MOODS) {
1172 ret = send_callback_request(mood_check_callback, NULL,
1173 afs_cb_result_handler, cc);
1174 if (ret < 0)
1175 return ret;
1176 }
1177 return 1;
1178 }
1179
1180 /**
1181 * The afs event dispatcher.
1182 *
1183 * \param event Type of the event.
1184 * \param pb May be \p NULL.
1185 * \param data Type depends on \a event.
1186 *
1187 * This function calls each table event handler, passing \a pb and \a data
1188 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1189 * handler returns negative, the loop is aborted.
1190 *
1191 * \return The (negative) error code of the first handler that failed, or non-negative
1192 * if all handlers succeeded.
1193 */
1194 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1195 void *data)
1196 {
1197 int i, ret;
1198
1199 for (i = 0; i < NUM_AFS_TABLES; i++) {
1200 struct afs_table *t = &afs_tables[i];
1201 if (!t->event_handler)
1202 continue;
1203 ret = t->event_handler(event, pb, data);
1204 if (ret < 0) {
1205 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1206 event, para_strerror(-ret));
1207 return ret;
1208 }
1209 }
1210 return 1;
1211 }
1212
1213 /**
1214 * Dummy event handler for the images table.
1215 *
1216 * \param event Unused.
1217 * \param pb Unused.
1218 * \param data Unused.
1219 *
1220 * \return The images table does not honor events, so this handler always
1221 * returns success.
1222 */
1223 __a_const int images_event_handler(__a_unused enum afs_events event,
1224 __a_unused struct para_buffer *pb, __a_unused void *data)
1225 {
1226 return 1;
1227 }
1228
1229 /**
1230 * Dummy event handler for the lyrics table.
1231 *
1232 * \param event Unused.
1233 * \param pb Unused.
1234 * \param data Unused.
1235 *
1236 * \return The lyrics table does not honor events, so this handler always
1237 * returns success.
1238 */
1239 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1240 __a_unused struct para_buffer *pb, __a_unused void *data)
1241 {
1242 return 1;
1243 }