2 * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file afs.c Paraslash's audio file selector. */
9 #include "server.cmdline.h"
14 #include <dirent.h> /* readdir() */
26 /** The osl tables used by afs. \sa blob.c. */
28 /** Contains audio file information. See aft.c. */
30 /** The table for the paraslash attributes. See attribute.c. */
33 * Paraslash's scoring system is based on Gaussian normal
34 * distributions, and the relevant data is stored in the rbtrees of an
35 * osl table containing only volatile columns. See score.c for
40 * A standard blob table containing the mood definitions. For details
44 /** A blob table containing lyrics on a per-song basis. */
46 /** Another blob table for images (for example album cover art). */
48 /** Yet another blob table for storing standard playlists. */
50 /** How many tables are in use? */
54 static struct table_info afs_tables[NUM_AFS_TABLES];
57 /** The file descriptor for the local socket. */
60 * Value sent by the command handlers to identify themselves as
61 * children of the running para_server.
64 /** The associated task structure. */
69 * A random number used to "authenticate" the connection.
71 * para_server picks this number by random before forking the afs process. The
72 * command handlers write this number together with the id of the shared memory
73 * area containing the query. This way, a malicious local user has to know this
74 * number to be able to cause the afs process to crash by sending fake queries.
76 extern uint32_t afs_socket_cookie;
79 * Struct to let command handlers execute a callback in afs context.
81 * Commands that need to change the state of afs can't change the relevant data
82 * structures directly because commands are executed in a child process, i.e.
83 * they get their own virtual address space.
85 * This structure is used by \p send_callback_request() (executed from handler
86 * context) in order to let the afs process call the specified function. An
87 * instance of that structure is written to a shared memory area together with
88 * the arguments to the callback function. The identifier of the shared memory
89 * area is written to the command socket.
91 * The afs process accepts connections on the command socket and reads the
92 * shared memory id, attaches the corresponing area, calls the given handler to
93 * perform the desired action and to optionally compute a result.
95 * The result and a \p callback_result structure is then written to another
96 * shared memory area. The identifier for that area is written to the handler's
97 * command socket, so that the handler process can read the id, attach the
98 * shared memory area and use the result.
100 * \sa struct callback_result.
102 struct callback_query {
103 /** The function to be called. */
104 callback_function *handler;
105 /** The number of bytes of the query */
110 * Structure embedded in the result of a callback.
112 * If the callback produced a result, an instance of that structure is embeeded
113 * into the shared memory area holding the result, mainly to let the command
114 * handler know the size of the result.
116 * \sa struct callback_query.
118 struct callback_result {
119 /** The number of bytes of the result. */
124 * Ask the parent process to call a given function.
126 * \param f The function to be called.
127 * \param query Pointer to arbitrary data for the callback.
128 * \param result Callback result will be stored here.
130 * This function creates a shared memory area, copies the buffer pointed to by
131 * \a buf to that area and notifies the afs process that \a f should be
134 * \return Negative, on errors, the return value of the callback function
137 * \sa send_option_arg_callback_request(), send_standard_callback_request().
139 int send_callback_request(callback_function *f, struct osl_object *query,
140 struct osl_object *result)
142 struct callback_query *cq;
143 struct callback_result *cr;
144 int ret, fd = -1, query_shmid, result_shmid;
145 void *query_shm, *result_shm;
146 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
147 // char *tmpsocket_name;
148 struct sockaddr_un unix_addr;
150 assert(query->data && query->size);
151 ret = shm_new(query->size + sizeof(*cq));
155 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
160 cq->query_size = query->size;
162 memcpy(query_shm + sizeof(*cq), query->data, query->size);
163 ret = shm_detach(query_shm);
167 *(uint32_t *) buf = afs_socket_cookie;
168 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
170 ret = get_stream_socket(PF_UNIX);
174 ret = init_unix_addr(&unix_addr, conf.afs_socket_arg);
178 if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) < 0) /* FIXME: Use para_connect() */
180 ret = send_bin_buffer(fd, buf, sizeof(buf));
181 PARA_NOTICE_LOG("bin buffer ret: %d\n", ret);
184 ret = recv_bin_buffer(fd, buf, sizeof(buf));
185 PARA_NOTICE_LOG("ret: %d\n", ret);
188 if (ret != sizeof(int)) {
193 PARA_NOTICE_LOG("result_shmid: %d\n", ret);
197 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
201 result->size = cr->result_size;
202 result->data = para_malloc(result->size);
203 memcpy(result->data, result_shm + sizeof(*cr), result->size);
204 ret = shm_detach(result_shm);
206 PARA_ERROR_LOG("can not detach result\n");
208 PARA_ERROR_LOG("attach result failed: %d\n", ret);
209 if (shm_destroy(result_shmid) < 0)
210 PARA_ERROR_LOG("destroy result failed\n");
213 if (shm_destroy(query_shmid) < 0)
214 PARA_ERROR_LOG("%s\n", "shm destroy error");
217 PARA_DEBUG_LOG("callback_ret: %d\n", ret);
222 * Send a callback request passing an options structure and an argument vector.
224 * \param options pointer to an arbitrary data structure.
225 * \param argc Argument count.
226 * \param argv Standard argument vector.
227 * \param f The callback function.
228 * \param result The result of the query is stored here.
230 * Some commands have a couple of options that are parsed in child context for
231 * syntactic correctness and are stored in a special options structure for that
232 * command. This function allows to pass such a structure together with a list
233 * of further arguments (often a list of audio files) to the parent process.
235 * \sa send_standard_callback_request(), send_callback_request().
237 int send_option_arg_callback_request(struct osl_object *options,
238 int argc, char * const * const argv, callback_function *f,
239 struct osl_object *result)
243 struct osl_object query = {.size = options? options->size : 0};
245 for (i = 0; i < argc; i++)
246 query.size += strlen(argv[i]) + 1;
247 query.data = para_malloc(query.size);
250 memcpy(query.data, options->data, options->size);
253 for (i = 0; i < argc; i++) {
254 strcpy(p, argv[i]); /* OK */
255 p += strlen(argv[i]) + 1;
257 ret = send_callback_request(f, &query, result);
263 * Send a callback request with an argument vector only.
265 * \param argc The same meaning as in send_option_arg_callback_request().
266 * \param argv The same meaning as in send_option_arg_callback_request().
267 * \param f The same meaning as in send_option_arg_callback_request().
268 * \param result The same meaning as in send_option_arg_callback_request().
270 * This is similar to send_option_arg_callback_request(), but no options buffer
271 * is passed to the parent process.
273 * \return The return value of the underlying call to
274 * send_option_arg_callback_request().
276 int send_standard_callback_request(int argc, char * const * const argv,
277 callback_function *f, struct osl_object *result)
279 return send_option_arg_callback_request(NULL, argc, argv, f, result);
283 * Compare two osl objects of string type.
285 * \param obj1 Pointer to the first object.
286 * \param obj2 Pointer to the second object.
288 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
289 * are taken into account.
291 * \return It returns an integer less than, equal to, or greater than zero if
292 * \a obj1 is found, respectively, to be less than, to match, or be greater than
295 * \sa strcmp(3), strncmp(3), osl_compare_func.
297 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
299 const char *str1 = (const char *)obj1->data;
300 const char *str2 = (const char *)obj2->data;
301 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
305 * A wrapper for strtol(3).
307 * \param str The string to be converted to a long integer.
308 * \param result The converted value is stored here.
310 * \return Positive on success, -E_ATOL on errors.
312 * \sa strtol(3), atoi(3).
314 int para_atol(const char *str, long *result)
320 errno = 0; /* To distinguish success/failure after call */
321 val = strtol(str, &endptr, base);
323 if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
324 goto out; /* overflow */
325 if (errno != 0 && val == 0)
326 goto out; /* other error */
328 goto out; /* No digits were found */
330 goto out; /* Further characters after number */
339 * write input from fd to dynamically allocated char array,
340 * but maximal max_size byte. Return size.
342 static int fd2buf(int fd, char **buf, int max_size)
344 const size_t chunk_size = 1024;
349 *buf = para_malloc(size * sizeof(char));
351 while ((ret = read(fd, p, chunk_size)) > 0) {
353 if ((p - *buf) + chunk_size >= size) {
357 if (size > max_size) {
358 ret = -E_INPUT_TOO_LARGE;
361 tmp = para_realloc(*buf, size);
362 p = (p - *buf) + tmp;
378 * Read from stdin, and send the result to the parent process.
380 * \param arg_obj Pointer to the arguments to \a f.
381 * \param f The callback function.
382 * \param max_len Don't read more than that many bytes from stdin.
383 * \param result The result of the query is stored here.
385 * This function is used by commands that wish to let para_server store
386 * arbitrary data specified by the user (for instance the add_blob family of
387 * commands). First, at most \a max_len bytes are read from stdin, the result
388 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
389 * is made available to the parent process via shared memory.
391 * \return Negative on errors, the return value of the underlying call to
392 * send_callback_request() otherwise.
394 int stdin_command(struct osl_object *arg_obj, callback_function *f,
395 unsigned max_len, struct osl_object *result)
399 struct osl_object query;
400 int ret = fd2buf(STDIN_FILENO, &stdin_buf, max_len);
405 query.size = arg_obj->size + stdin_len;
406 query.data = para_malloc(query.size);
407 memcpy(query.data, arg_obj->data, arg_obj->size);
408 memcpy((char *)query.data + arg_obj->size, stdin_buf, stdin_len);
410 ret = send_callback_request(f, &query, result);
416 * Open the audio file with highest score.
418 * \param afd Audio file data is returned here.
420 * This stores all information for streaming the "best" audio file
421 * in the \a afd structure.
423 * \return Positive on success, negative on errors.
425 * \sa close_audio_file(), open_and_update_audio_file().
427 int open_next_audio_file(struct audio_file_data *afd)
429 struct osl_row *aft_row;
432 ret = score_get_best(&aft_row, &afd->score);
435 ret = open_and_update_audio_file(aft_row, afd);
442 * Free all resources which were allocated by open_next_audio_file().
444 * \param afd The structure previously filled in by open_next_audio_file().
446 * \return The return value of the underlying call to para_munmap().
448 * \sa open_next_audio_file().
450 int close_audio_file(struct audio_file_data *afd)
452 free(afd->afhi.chunk_table);
453 return para_munmap(afd->map.data, afd->map.size);
457 static void play_loop(enum play_mode current_play_mode)
460 struct audio_file_data afd;
462 afd.current_play_mode = current_play_mode;
463 for (i = 0; i < 0; i++) {
464 ret = open_next_audio_file(&afd);
466 PARA_ERROR_LOG("failed to open next audio file: %d\n", ret);
469 PARA_NOTICE_LOG("next audio file: %s, score: %li\n", afd.path, afd.score);
471 close_audio_file(&afd);
477 static enum play_mode init_admissible_files(void)
480 char *given_mood, *given_playlist;
482 given_mood = "mood_that_was_given_at_the_command_line";
483 given_playlist = "given_playlist";
486 ret = mood_open(given_mood);
489 PARA_WARNING_LOG("ignoring playlist %s\n",
491 return PLAY_MODE_MOOD;
494 if (given_playlist) {
495 ret = playlist_open(given_playlist);
497 return PLAY_MODE_PLAYLIST;
499 ret = mood_open(NULL); /* open first available mood */
501 return PLAY_MODE_MOOD;
502 mood_open(""); /* open dummy mood, always successful */
503 return PLAY_MODE_MOOD;
506 static int setup_command_socket_or_die(void)
509 char *socket_name = conf.afs_socket_arg;
510 struct sockaddr_un unix_addr;
513 ret = create_local_socket(socket_name, &unix_addr,
514 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
517 if (listen(ret , 5) < 0) {
518 PARA_EMERG_LOG("%s", "can not listen on socket\n");
521 PARA_INFO_LOG("listening on command socket %s (fd %d)\n", socket_name,
526 static int server_socket;
527 static struct command_task command_task_struct;
528 static struct signal_task signal_task_struct;
530 static void unregister_tasks(void)
532 unregister_task(&command_task_struct.task);
533 unregister_task(&signal_task_struct.task);
536 static void afs_shutdown(enum osl_close_flags flags)
538 PARA_NOTICE_LOG("cleaning up\n");
539 score_shutdown(flags);
540 attribute_shutdown(flags);
543 moods_shutdown(flags);
544 playlists_shutdown(flags);
545 lyrics_shutdown(flags);
546 images_shutdown(flags);
550 static void signal_pre_select(struct sched *s, struct task *t)
552 struct signal_task *st = t->private_data;
554 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
557 static void signal_post_select(struct sched *s, struct task *t)
559 struct signal_task *st = t->private_data;
561 if (!FD_ISSET(st->fd, &s->rfds))
563 st->signum = para_next_signal();
564 PARA_NOTICE_LOG("caught signal %d\n", st->signum);
566 if (st->signum == SIGUSR1)
567 return; /* ignore SIGUSR1 */
568 t->ret = -E_SIGNAL_CAUGHT;
572 static void register_signal_task(void)
574 struct signal_task *st = &signal_task_struct;
575 st->fd = para_signal_init();
576 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
577 para_install_sighandler(SIGINT);
578 para_install_sighandler(SIGTERM);
579 para_install_sighandler(SIGPIPE);
581 st->task.pre_select = signal_pre_select;
582 st->task.post_select = signal_post_select;
583 st->task.private_data = st;
584 sprintf(st->task.status, "signal task");
585 register_task(&st->task);
588 static void command_pre_select(struct sched *s, struct task *t)
590 struct command_task *ct = t->private_data;
592 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
596 * On errors, negative value is written to fd.
597 * On success: If query produced a result, the result_shmid is written to fd.
598 * Otherwise, zero is written.
600 static int call_callback(int fd, int query_shmid)
602 void *query_shm, *result_shm;
603 struct callback_query *cq;
604 struct callback_result *cr;
605 struct osl_object query, result = {.data = NULL};
606 int result_shmid = -1, ret, ret2;
608 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
612 query.data = (char *)query_shm + sizeof(*cq);
613 query.size = cq->query_size;
614 ret = cq->handler(&query, &result);
615 ret2 = shm_detach(query_shm);
616 if (ret2 < 0 && ret >= 0)
621 if (!result.data || !result.size)
623 ret = shm_new(result.size + sizeof(struct callback_result));
627 ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
631 cr->result_size = result.size;
632 memcpy(result_shm + sizeof(*cr), result.data, result.size);
633 ret = shm_detach(result_shm);
639 ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int));
640 if (ret < 0 || ret2 < 0) {
641 if (result_shmid >= 0)
642 if (shm_destroy(result_shmid) < 0)
643 PARA_ERROR_LOG("destroy result failed\n");
650 static void command_post_select(struct sched *s, struct task *t)
652 struct command_task *ct = t->private_data;
653 struct sockaddr_un unix_addr;
654 char buf[sizeof(uint32_t) + sizeof(int)];
659 if (!FD_ISSET(ct->fd, &s->rfds))
661 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
665 * The following errors may be caused by a malicious local user. So do
666 * not return an error in this case as this would terminate para_afs
670 /* FIXME: This is easily dosable (peer doesn't send data) */
671 t->ret = recv_bin_buffer(fd, buf, sizeof(buf));
673 PARA_NOTICE_LOG("%s (%d)\n", PARA_STRERROR(-t->ret), t->ret);
677 if (t->ret != sizeof(buf)) {
678 PARA_NOTICE_LOG("short read (%d bytes, expected %u)\n",
679 t->ret, sizeof(buf));
683 cookie = *(uint32_t *)buf;
684 if (cookie != ct->cookie) {
685 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
686 (unsigned)cookie, (unsigned)ct->cookie);
690 query_shmid = *(int *)(buf + sizeof(cookie));
691 if (query_shmid < 0) {
692 PARA_WARNING_LOG("received invalid query shmid %d)\n",
697 t->ret = call_callback(fd, query_shmid);
699 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
707 static void register_command_task(uint32_t cookie)
709 struct command_task *ct = &command_task_struct;
710 ct->fd = setup_command_socket_or_die();
713 ct->task.pre_select = command_pre_select;
714 ct->task.post_select = command_post_select;
715 ct->task.private_data = ct;
716 sprintf(ct->task.status, "command task");
717 register_task(&ct->task);
720 void register_tasks(uint32_t cookie)
722 register_signal_task();
723 register_command_task(cookie);
726 static int open_afs_tables(void)
731 if (conf.afs_database_dir_given)
732 db = conf.afs_database_dir_arg;
734 char *home = para_homedir();
735 db = make_message("%s/.paraslash/afs_database", home);
738 PARA_INFO_LOG("afs_database dir %s\n", db);
739 ret = para_mkdir(db, 0777);
740 if (ret < 0 && ret != -E_EXIST)
742 ret = attribute_init(&afs_tables[TBLNUM_ATTRIBUTES], db);
745 ret = moods_init(&afs_tables[TBLNUM_MOODS], db);
747 goto moods_init_error;
748 ret = playlists_init(&afs_tables[TBLNUM_PLAYLIST], db);
750 goto playlists_init_error;
751 ret = lyrics_init(&afs_tables[TBLNUM_LYRICS], db);
753 goto lyrics_init_error;
754 ret = images_init(&afs_tables[TBLNUM_IMAGES], db);
756 goto images_init_error;
757 ret = score_init(&afs_tables[TBLNUM_SCORES], db);
759 goto score_init_error;
760 ret = aft_init(&afs_tables[TBLNUM_AUDIO_FILES], db);
763 if (!conf.afs_database_dir_given)
768 score_shutdown(OSL_MARK_CLEAN);
770 images_shutdown(OSL_MARK_CLEAN);
772 lyrics_shutdown(OSL_MARK_CLEAN);
774 playlists_shutdown(OSL_MARK_CLEAN);
775 playlists_init_error:
776 moods_shutdown(OSL_MARK_CLEAN);
778 attribute_shutdown(OSL_MARK_CLEAN);
780 if (!conf.afs_database_dir_given)
785 __noreturn int afs_init(uint32_t cookie, int socket_fd)
787 enum play_mode current_play_mode;
789 int ret = open_afs_tables();
792 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
795 server_socket = socket_fd;
796 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
797 server_socket, (unsigned) cookie);
798 current_play_mode = init_admissible_files();
799 register_tasks(cookie);
800 s.default_timeout.tv_sec = 0;
801 s.default_timeout.tv_usec = 99 * 1000;
804 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
805 afs_shutdown(OSL_MARK_CLEAN);
809 static int create_all_tables(void)
813 for (i = 0; i < NUM_AFS_TABLES; i++) {
814 struct table_info *ti = afs_tables + i;
816 if (ti->flags & TBLFLAG_SKIP_CREATE)
818 ret = osl_create_table(ti->desc);
825 int com_init(int fd, int argc, char * const * const argv)
830 ret = create_all_tables();
833 return open_afs_tables();
835 for (i = 1; i < argc; i++) {
836 for (j = 0; j < NUM_AFS_TABLES; j++) {
837 struct table_info *ti = afs_tables + j;
839 if (ti->flags & TBLFLAG_SKIP_CREATE)
841 if (strcmp(argv[i], ti->desc->name))
843 ret = send_va_buffer(fd, "creating table %s\n", argv[i]);
846 ret = osl_create_table(ti->desc);
851 if (j == NUM_AFS_TABLES)
852 return -E_BAD_TABLE_NAME;
854 return open_afs_tables();