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