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 struct sockaddr_un unix_addr;
148 size_t query_shm_size = sizeof(*cq);
151 query_shm_size += query->size;
152 ret = shm_new(query_shm_size);
156 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
161 cq->query_size = query_shm_size - sizeof(*cq);
164 memcpy(query_shm + sizeof(*cq), query->data, query->size);
165 ret = shm_detach(query_shm);
169 *(uint32_t *) buf = afs_socket_cookie;
170 *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid;
172 ret = get_stream_socket(PF_UNIX);
176 ret = init_unix_addr(&unix_addr, conf.afs_socket_arg);
179 ret = PARA_CONNECT(fd, &unix_addr);
182 ret = send_bin_buffer(fd, buf, sizeof(buf));
185 ret = recv_bin_buffer(fd, buf, sizeof(buf));
188 if (ret != sizeof(int)) {
196 ret = shm_attach(result_shmid, ATTACH_RO, &result_shm);
200 result->size = cr->result_size;
201 result->data = para_malloc(result->size);
202 memcpy(result->data, result_shm + sizeof(*cr), result->size);
203 ret = shm_detach(result_shm);
205 PARA_ERROR_LOG("can not detach result\n");
207 PARA_ERROR_LOG("attach result failed: %d\n", ret);
208 if (shm_destroy(result_shmid) < 0)
209 PARA_ERROR_LOG("destroy result failed\n");
212 if (shm_destroy(query_shmid) < 0)
213 PARA_ERROR_LOG("%s\n", "shm destroy error");
216 // PARA_DEBUG_LOG("callback_ret: %d\n", ret);
221 * Send a callback request passing an options structure and an argument vector.
223 * \param options pointer to an arbitrary data structure.
224 * \param argc Argument count.
225 * \param argv Standard argument vector.
226 * \param f The callback function.
227 * \param result The result of the query is stored here.
229 * Some commands have a couple of options that are parsed in child context for
230 * syntactic correctness and are stored in a special options structure for that
231 * command. This function allows to pass such a structure together with a list
232 * of further arguments (often a list of audio files) to the parent process.
234 * \sa send_standard_callback_request(), send_callback_request().
236 int send_option_arg_callback_request(struct osl_object *options,
237 int argc, char * const * const argv, callback_function *f,
238 struct osl_object *result)
242 struct osl_object query = {.size = options? options->size : 0};
244 for (i = 0; i < argc; i++)
245 query.size += strlen(argv[i]) + 1;
246 query.data = para_malloc(query.size);
249 memcpy(query.data, options->data, options->size);
252 for (i = 0; i < argc; i++) {
253 strcpy(p, argv[i]); /* OK */
254 p += strlen(argv[i]) + 1;
256 ret = send_callback_request(f, &query, result);
262 * Send a callback request with an argument vector only.
264 * \param argc The same meaning as in send_option_arg_callback_request().
265 * \param argv The same meaning as in send_option_arg_callback_request().
266 * \param f The same meaning as in send_option_arg_callback_request().
267 * \param result The same meaning as in send_option_arg_callback_request().
269 * This is similar to send_option_arg_callback_request(), but no options buffer
270 * is passed to the parent process.
272 * \return The return value of the underlying call to
273 * send_option_arg_callback_request().
275 int send_standard_callback_request(int argc, char * const * const argv,
276 callback_function *f, struct osl_object *result)
278 return send_option_arg_callback_request(NULL, argc, argv, f, result);
282 * Compare two osl objects of string type.
284 * \param obj1 Pointer to the first object.
285 * \param obj2 Pointer to the second object.
287 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
288 * are taken into account.
290 * \return It returns an integer less than, equal to, or greater than zero if
291 * \a obj1 is found, respectively, to be less than, to match, or be greater than
294 * \sa strcmp(3), strncmp(3), osl_compare_func.
296 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
298 const char *str1 = (const char *)obj1->data;
299 const char *str2 = (const char *)obj2->data;
300 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
304 * A wrapper for strtol(3).
306 * \param str The string to be converted to a long integer.
307 * \param result The converted value is stored here.
309 * \return Positive on success, -E_ATOL on errors.
311 * \sa strtol(3), atoi(3).
313 int para_atol(const char *str, long *result)
319 errno = 0; /* To distinguish success/failure after call */
320 val = strtol(str, &endptr, base);
322 if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
323 goto out; /* overflow */
324 if (errno != 0 && val == 0)
325 goto out; /* other error */
327 goto out; /* No digits were found */
329 goto out; /* Further characters after number */
338 * write input from fd to dynamically allocated buffer,
339 * but maximal max_size byte.
341 static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
343 const size_t chunk_size = 1024;
344 size_t size = 2048, received = 0;
346 char *buf = para_malloc(size);
349 ret = recv_bin_buffer(fd, buf + received, chunk_size);
353 if (received + chunk_size >= size) {
355 ret = -E_INPUT_TOO_LARGE;
358 buf = para_realloc(buf, size);
362 obj->size = received;
369 * Read data from a file descriptor, and send it to the afs process.
371 * \param fd File descriptor to read data from.
372 * \param arg_obj Pointer to the arguments to \a f.
373 * \param f The callback function.
374 * \param max_len Don't read more than that many bytes from stdin.
375 * \param result The result of the query is stored here.
377 * This function is used by commands that wish to let para_server store
378 * arbitrary data specified by the user (for instance the add_blob family of
379 * commands). First, at most \a max_len bytes are read from \a fd, the result
380 * is concatenated with the buffer given by \a arg_obj, and the combined buffer
381 * is made available to the parent process via shared memory.
383 * \return Negative on errors, the return value of the underlying call to
384 * send_callback_request() otherwise.
386 int stdin_command(int fd, struct osl_object *arg_obj, callback_function *f,
387 unsigned max_len, struct osl_object *result)
389 struct osl_object query, stdin_obj;
392 ret = send_buffer(fd, AWAITING_DATA_MSG);
395 ret = fd2buf(fd, max_len, &stdin_obj);
398 query.size = arg_obj->size + stdin_obj.size;
399 query.data = para_malloc(query.size);
400 memcpy(query.data, arg_obj->data, arg_obj->size);
401 memcpy((char *)query.data + arg_obj->size, stdin_obj.data, stdin_obj.size);
402 free(stdin_obj.data);
403 ret = send_callback_request(f, &query, result);
409 * Open the audio file with highest score.
411 * \param afd Audio file data is returned here.
413 * This stores all information for streaming the "best" audio file
414 * in the \a afd structure.
416 * \return Positive on success, negative on errors.
418 * \sa close_audio_file(), open_and_update_audio_file().
420 int open_next_audio_file(struct audio_file_data *afd)
422 struct osl_row *aft_row;
425 ret = score_get_best(&aft_row, &afd->score);
428 ret = open_and_update_audio_file(aft_row, afd);
435 * Free all resources which were allocated by open_next_audio_file().
437 * \param afd The structure previously filled in by open_next_audio_file().
439 * \return The return value of the underlying call to para_munmap().
441 * \sa open_next_audio_file().
443 int close_audio_file(struct audio_file_data *afd)
445 free(afd->afhi.chunk_table);
446 return para_munmap(afd->map.data, afd->map.size);
450 static void play_loop(enum play_mode current_play_mode)
453 struct audio_file_data afd;
455 afd.current_play_mode = current_play_mode;
456 for (i = 0; i < 0; i++) {
457 ret = open_next_audio_file(&afd);
459 PARA_ERROR_LOG("failed to open next audio file: %d\n", ret);
462 PARA_NOTICE_LOG("next audio file: %s, score: %li\n", afd.path, afd.score);
464 close_audio_file(&afd);
470 static enum play_mode init_admissible_files(void)
473 char *given_mood, *given_playlist;
475 given_mood = "mood_that_was_given_at_the_command_line";
476 given_playlist = "given_playlist";
479 ret = mood_open(given_mood);
482 PARA_WARNING_LOG("ignoring playlist %s\n",
484 return PLAY_MODE_MOOD;
487 if (given_playlist) {
488 ret = playlist_open(given_playlist);
490 return PLAY_MODE_PLAYLIST;
492 ret = mood_open(NULL); /* open first available mood */
494 return PLAY_MODE_MOOD;
495 mood_open(""); /* open dummy mood, always successful */
496 return PLAY_MODE_MOOD;
499 static int setup_command_socket_or_die(void)
502 char *socket_name = conf.afs_socket_arg;
503 struct sockaddr_un unix_addr;
506 ret = create_local_socket(socket_name, &unix_addr,
507 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
509 PARA_EMERG_LOG("%s: %s\n", PARA_STRERROR(-ret), socket_name);
512 if (listen(ret , 5) < 0) {
513 PARA_EMERG_LOG("%s", "can not listen on socket\n");
516 PARA_INFO_LOG("listening on command socket %s (fd %d)\n", socket_name,
521 static int server_socket;
522 static struct command_task command_task_struct;
523 static struct signal_task signal_task_struct;
525 static void unregister_tasks(void)
527 unregister_task(&command_task_struct.task);
528 unregister_task(&signal_task_struct.task);
531 static void close_afs_tables(enum osl_close_flags flags)
533 PARA_NOTICE_LOG("closing afs_tables\n");
534 score_shutdown(flags);
535 attribute_shutdown(flags);
538 moods_shutdown(flags);
539 playlists_shutdown(flags);
540 lyrics_shutdown(flags);
541 images_shutdown(flags);
545 static void signal_pre_select(struct sched *s, struct task *t)
547 struct signal_task *st = t->private_data;
549 para_fd_set(st->fd, &s->rfds, &s->max_fileno);
552 static void signal_post_select(struct sched *s, struct task *t)
554 struct signal_task *st = t->private_data;
556 if (!FD_ISSET(st->fd, &s->rfds))
558 st->signum = para_next_signal();
560 if (st->signum == SIGUSR1)
561 return; /* ignore SIGUSR1 */
562 PARA_NOTICE_LOG("caught signal %d\n", st->signum);
563 t->ret = -E_SIGNAL_CAUGHT;
567 static void register_signal_task(void)
569 struct signal_task *st = &signal_task_struct;
570 st->fd = para_signal_init();
571 PARA_INFO_LOG("signal pipe: fd %d\n", st->fd);
572 para_install_sighandler(SIGINT);
573 para_install_sighandler(SIGTERM);
574 para_install_sighandler(SIGPIPE);
576 st->task.pre_select = signal_pre_select;
577 st->task.post_select = signal_post_select;
578 st->task.private_data = st;
579 sprintf(st->task.status, "signal task");
580 register_task(&st->task);
583 static void command_pre_select(struct sched *s, struct task *t)
585 struct command_task *ct = t->private_data;
587 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
591 * On errors, negative value is written to fd.
592 * On success: If query produced a result, the result_shmid is written to fd.
593 * Otherwise, zero is written.
595 static int call_callback(int fd, int query_shmid)
597 void *query_shm, *result_shm;
598 struct callback_query *cq;
599 struct callback_result *cr;
600 struct osl_object query, result = {.data = NULL};
601 int result_shmid = -1, ret, ret2;
603 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
607 query.data = (char *)query_shm + sizeof(*cq);
608 query.size = cq->query_size;
609 ret = cq->handler(&query, &result);
610 ret2 = shm_detach(query_shm);
611 if (ret2 < 0 && ret >= 0)
616 if (!result.data || !result.size)
618 ret = shm_new(result.size + sizeof(struct callback_result));
622 ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
626 cr->result_size = result.size;
627 memcpy(result_shm + sizeof(*cr), result.data, result.size);
628 ret = shm_detach(result_shm);
634 ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int));
635 if (ret < 0 || ret2 < 0) {
636 if (result_shmid >= 0)
637 if (shm_destroy(result_shmid) < 0)
638 PARA_ERROR_LOG("destroy result failed\n");
645 static void command_post_select(struct sched *s, struct task *t)
647 struct command_task *ct = t->private_data;
648 struct sockaddr_un unix_addr;
649 char buf[sizeof(uint32_t) + sizeof(int)];
654 if (!FD_ISSET(ct->fd, &s->rfds))
656 t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr));
660 * The following errors may be caused by a malicious local user. So do
661 * not return an error in this case as this would terminate para_afs
665 /* FIXME: This is easily dosable (peer doesn't send data) */
666 t->ret = recv_bin_buffer(fd, buf, sizeof(buf));
668 PARA_NOTICE_LOG("%s (%d)\n", PARA_STRERROR(-t->ret), t->ret);
671 if (t->ret != sizeof(buf)) {
672 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
673 t->ret, (long unsigned) sizeof(buf));
676 cookie = *(uint32_t *)buf;
677 if (cookie != ct->cookie) {
678 PARA_NOTICE_LOG("received invalid cookie(got %u, expected %u)\n",
679 (unsigned)cookie, (unsigned)ct->cookie);
682 query_shmid = *(int *)(buf + sizeof(cookie));
683 if (query_shmid < 0) {
684 PARA_WARNING_LOG("received invalid query shmid %d)\n",
688 /* Ignore return value: Errors might be ok here. */
689 call_callback(fd, query_shmid);
695 static void register_command_task(uint32_t cookie)
697 struct command_task *ct = &command_task_struct;
698 ct->fd = setup_command_socket_or_die();
701 ct->task.pre_select = command_pre_select;
702 ct->task.post_select = command_post_select;
703 ct->task.private_data = ct;
704 sprintf(ct->task.status, "command task");
705 register_task(&ct->task);
708 void register_tasks(uint32_t cookie)
710 register_signal_task();
711 register_command_task(cookie);
714 static char *database_dir;
716 static int make_database_dir(void)
721 if (conf.afs_database_dir_given)
722 database_dir = para_strdup(conf.afs_database_dir_arg);
724 char *home = para_homedir();
725 database_dir = make_message(
726 "%s/.paraslash/afs_database", home);
730 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
731 ret = para_mkdir(database_dir, 0777);
732 if (ret >= 0 || ret == -E_EXIST)
739 static int open_afs_tables(void)
741 int ret = make_database_dir();
745 ret = attribute_init(&afs_tables[TBLNUM_ATTRIBUTES], database_dir);
748 ret = moods_init(&afs_tables[TBLNUM_MOODS], database_dir);
750 goto moods_init_error;
751 ret = playlists_init(&afs_tables[TBLNUM_PLAYLIST], database_dir);
753 goto playlists_init_error;
754 ret = lyrics_init(&afs_tables[TBLNUM_LYRICS], database_dir);
756 goto lyrics_init_error;
757 ret = images_init(&afs_tables[TBLNUM_IMAGES], database_dir);
759 goto images_init_error;
760 ret = score_init(&afs_tables[TBLNUM_SCORES], database_dir);
762 goto score_init_error;
763 ret = aft_init(&afs_tables[TBLNUM_AUDIO_FILES], database_dir);
769 score_shutdown(OSL_MARK_CLEAN);
771 images_shutdown(OSL_MARK_CLEAN);
773 lyrics_shutdown(OSL_MARK_CLEAN);
775 playlists_shutdown(OSL_MARK_CLEAN);
776 playlists_init_error:
777 moods_shutdown(OSL_MARK_CLEAN);
779 attribute_shutdown(OSL_MARK_CLEAN);
783 __noreturn int afs_init(uint32_t cookie, int socket_fd)
785 enum play_mode current_play_mode;
787 int ret = open_afs_tables();
790 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
793 server_socket = socket_fd;
794 ret = mark_fd_nonblock(server_socket);
797 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
798 server_socket, (unsigned) cookie);
799 current_play_mode = init_admissible_files();
800 register_tasks(cookie);
801 s.default_timeout.tv_sec = 0;
802 s.default_timeout.tv_usec = 99 * 1000;
805 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
806 close_afs_tables(OSL_MARK_CLEAN);
810 static int create_tables_callback(const struct osl_object *query,
811 __a_unused struct osl_object *result)
813 uint32_t table_mask = *(uint32_t *)query->data;
816 close_afs_tables(OSL_MARK_CLEAN);
817 for (i = 0; i < NUM_AFS_TABLES; i++) {
818 struct table_info *ti = afs_tables + i;
820 if (ti->flags & TBLFLAG_SKIP_CREATE)
822 if (!(table_mask & (1 << i)))
824 ret = osl_create_table(ti->desc);
828 ret = open_afs_tables();
829 return ret < 0? ret: 0;
832 int com_init(int fd, int argc, char * const * const argv)
835 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
836 struct osl_object query = {.data = &table_mask,
837 .size = sizeof(table_mask)};
841 for (i = 1; i < argc; i++) {
842 for (j = 0; j < NUM_AFS_TABLES; j++) {
843 struct table_info *ti = afs_tables + j;
845 if (ti->flags & TBLFLAG_SKIP_CREATE)
847 if (strcmp(argv[i], ti->desc->name))
849 table_mask |= (1 << j);
852 if (j == NUM_AFS_TABLES)
853 return -E_BAD_TABLE_NAME;
856 ret = send_callback_request(create_tables_callback, &query, NULL);
859 return send_va_buffer(fd, "successfully created afs table(s)\n");
862 enum com_check_flags {
868 int com_check(int fd, int argc, char * const * const argv)
872 struct osl_object result;
874 for (i = 1; i < argc; i++) {
875 const char *arg = argv[i];
878 if (!strcmp(arg, "--")) {
882 if (!strcmp(arg, "-a")) {
886 if (!strcmp(arg, "-p")) {
887 flags |= CHECK_PLAYLISTS;
890 if (!strcmp(arg, "-m")) {
891 flags |= CHECK_MOODS;
894 return -E_AFS_SYNTAX;
897 return -E_AFS_SYNTAX;
900 if (flags & CHECK_AFT) {
901 ret = send_callback_request(aft_check_callback, NULL, &result);
905 ret = send_buffer(fd, (char *) result.data);
911 if (flags & CHECK_PLAYLISTS) {
912 ret = send_callback_request(playlist_check_callback, NULL, &result);
916 ret = send_buffer(fd, (char *) result.data);