diff options
Diffstat (limited to 'mpd.c')
| -rw-r--r-- | mpd.c | 649 |
1 files changed, 0 insertions, 649 deletions
@@ -1,649 +0,0 @@ -// Copied from desktop-tools, should go to liberty if it proves useful -// XXX: changed: added a debugging callback instead of hardcoded print_debug - -// --- MPD client interface ---------------------------------------------------- - -// This is a rather thin MPD client interface intended for basic tasks - -#define MPD_SUBSYSTEM_TABLE(XX) \ - XX (DATABASE, 0, "database") \ - XX (UPDATE, 1, "update") \ - XX (STORED_PLAYLIST, 2, "stored_playlist") \ - XX (PLAYLIST, 3, "playlist") \ - XX (PLAYER, 4, "player") \ - XX (MIXER, 5, "mixer") \ - XX (OUTPUT, 6, "output") \ - XX (OPTIONS, 7, "options") \ - XX (STICKER, 8, "sticker") \ - XX (SUBSCRIPTION, 9, "subscription") \ - XX (MESSAGE, 10, "message") - -enum mpd_subsystem -{ -#define XX(a, b, c) MPD_SUBSYSTEM_ ## a = (1 << b), - MPD_SUBSYSTEM_TABLE (XX) -#undef XX - MPD_SUBSYSTEM_MAX -}; - -static const char *mpd_subsystem_names[] = -{ -#define XX(a, b, c) [b] = c, - MPD_SUBSYSTEM_TABLE (XX) -#undef XX -}; - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -enum mpd_client_state -{ - MPD_DISCONNECTED, ///< Not connected - MPD_CONNECTING, ///< Currently connecting - MPD_CONNECTED ///< Connected -}; - -struct mpd_response -{ - bool success; ///< OK or ACK - - // ACK-only fields: - - int error; ///< Numeric error value (ack.h) - int list_offset; ///< Offset of command in list - char *current_command; ///< Name of the erroring command - char *message_text; ///< Error message -}; - -/// Task completion callback -typedef void (*mpd_client_task_cb) (const struct mpd_response *response, - const struct str_vector *data, void *user_data); - -struct mpd_client_task -{ - LIST_HEADER (struct mpd_client_task) - - mpd_client_task_cb callback; ///< Callback on completion - void *user_data; ///< User data -}; - -struct mpd_client -{ - struct poller *poller; ///< Poller - - // Connection: - - enum mpd_client_state state; ///< Connection state - struct connector *connector; ///< Connection establisher - - int socket; ///< MPD socket - struct str read_buffer; ///< Input yet to be processed - struct str write_buffer; ///< Outut yet to be be sent out - struct poller_fd socket_event; ///< We can read from the socket - - struct poller_timer timeout_timer; ///< Connection seems to be dead - - // Protocol: - - bool got_hello; ///< Got the OK MPD hello message - - bool idling; ///< Sent idle as the last command - unsigned idling_subsystems; ///< Subsystems we're idling for - bool in_list; ///< We're inside a command list - - struct mpd_client_task *tasks; ///< Task queue - struct mpd_client_task *tasks_tail; ///< Tail of task queue - struct str_vector data; ///< Data from last command - - // User configuration: - - void *user_data; ///< User data for callbacks - - /// Callback after connection has been successfully established - void (*on_connected) (void *user_data); - - /// Callback for general failures or even normal disconnection; - /// the interface is reinitialized - void (*on_failure) (void *user_data); - - /// Callback to receive "idle" updates. - /// Remember to restart the idle if needed. - void (*on_event) (unsigned subsystems, void *user_data); - - /// Callback to trace protocol I/O - void (*on_io_hook) (void *user_data, bool outgoing, const char *line); -}; - -static void mpd_client_reset (struct mpd_client *self); -static void mpd_client_destroy_connector (struct mpd_client *self); - -static void -mpd_client_init (struct mpd_client *self, struct poller *poller) -{ - memset (self, 0, sizeof *self); - - self->poller = poller; - self->socket = -1; - - str_init (&self->read_buffer); - str_init (&self->write_buffer); - - str_vector_init (&self->data); - - poller_fd_init (&self->socket_event, poller, -1); - poller_timer_init (&self->timeout_timer, poller); -} - -static void -mpd_client_free (struct mpd_client *self) -{ - // So that we don't have to repeat most of the stuff - mpd_client_reset (self); - - str_free (&self->read_buffer); - str_free (&self->write_buffer); - - str_vector_free (&self->data); -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -/// Reinitialize the interface so that you can reconnect anew -static void -mpd_client_reset (struct mpd_client *self) -{ - if (self->state == MPD_CONNECTING) - mpd_client_destroy_connector (self); - - if (self->socket != -1) - xclose (self->socket); - self->socket = -1; - - self->socket_event.closed = true; - poller_fd_reset (&self->socket_event); - poller_timer_reset (&self->timeout_timer); - - str_reset (&self->read_buffer); - str_reset (&self->write_buffer); - - str_vector_reset (&self->data); - - self->got_hello = false; - self->idling = false; - self->idling_subsystems = 0; - self->in_list = false; - - LIST_FOR_EACH (struct mpd_client_task, iter, self->tasks) - free (iter); - self->tasks = self->tasks_tail = NULL; - - self->state = MPD_DISCONNECTED; -} - -static void -mpd_client_fail (struct mpd_client *self) -{ - mpd_client_reset (self); - if (self->on_failure) - self->on_failure (self->user_data); -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static bool -mpd_client_parse_response (const char *p, struct mpd_response *response) -{ - if (!strcmp (p, "OK")) - return response->success = true; - if (!strcmp (p, "list_OK")) - // TODO: either implement this or fail the connection properly - hard_assert (!"command_list_ok_begin not implemented"); - - char *end = NULL; - if (*p++ != 'A' || *p++ != 'C' || *p++ != 'K' || *p++ != ' ' || *p++ != '[') - return false; - - errno = 0; - response->error = strtoul (p, &end, 10); - if (errno != 0 || end == p) - return false; - p = end; - if (*p++ != '@') - return false; - - errno = 0; - response->list_offset = strtoul (p, &end, 10); - if (errno != 0 || end == p) - return false; - p = end; - if (*p++ != ']' || *p++ != ' ' || *p++ != '{' || !(end = strchr (p, '}'))) - return false; - - response->current_command = xstrndup (p, end - p); - p = end + 1; - - if (*p++ != ' ') - return false; - - response->message_text = xstrdup (p); - response->success = false; - return true; -} - -static void -mpd_client_dispatch (struct mpd_client *self, struct mpd_response *response) -{ - struct mpd_client_task *task; - if (!(task = self->tasks)) - return; - - if (task->callback) - task->callback (response, &self->data, task->user_data); - str_vector_reset (&self->data); - - LIST_UNLINK_WITH_TAIL (self->tasks, self->tasks_tail, task); - free (task); -} - -static bool -mpd_client_parse_hello (struct mpd_client *self, const char *line) -{ - const char hello[] = "OK MPD "; - if (strncmp (line, hello, sizeof hello - 1)) - { - print_debug ("invalid MPD hello message"); - return false; - } - - // TODO: call "on_connected" now. We should however also set up a timer - // so that we don't wait on this message forever. - return self->got_hello = true; -} - -static bool -mpd_client_parse_line (struct mpd_client *self, const char *line) -{ - if (self->on_io_hook) - self->on_io_hook (self->user_data, false, line); - - if (!self->got_hello) - return mpd_client_parse_hello (self, line); - - struct mpd_response response; - memset (&response, 0, sizeof response); - if (mpd_client_parse_response (line, &response)) - { - mpd_client_dispatch (self, &response); - free (response.current_command); - free (response.message_text); - } - else - str_vector_add (&self->data, line); - return true; -} - -/// All output from MPD commands seems to be in a trivial "key: value" format -static char * -mpd_client_parse_kv (char *line, char **value) -{ - char *sep; - if (!(sep = strstr (line, ": "))) - return NULL; - - *sep = 0; - *value = sep + 2; - return line; -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static void -mpd_client_update_poller (struct mpd_client *self) -{ - poller_fd_set (&self->socket_event, - self->write_buffer.len ? (POLLIN | POLLOUT) : POLLIN); -} - -static bool -mpd_client_process_input (struct mpd_client *self) -{ - // Split socket input at newlines and process them separately - struct str *rb = &self->read_buffer; - char *start = rb->str, *end = start + rb->len; - for (char *p = start; p < end; p++) - { - if (*p != '\n') - continue; - - *p = 0; - if (!mpd_client_parse_line (self, start)) - return false; - start = p + 1; - } - - str_remove_slice (rb, 0, start - rb->str); - return true; -} - -static void -mpd_client_on_ready (const struct pollfd *pfd, void *user_data) -{ - (void) pfd; - - struct mpd_client *self = user_data; - if (socket_io_try_read (self->socket, &self->read_buffer) != SOCKET_IO_OK - || !mpd_client_process_input (self) - || socket_io_try_write (self->socket, &self->write_buffer) != SOCKET_IO_OK) - mpd_client_fail (self); - else - mpd_client_update_poller (self); -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static bool -mpd_client_must_quote_char (char c) -{ - return (unsigned char) c <= ' ' || c == '"' || c == '\''; -} - -static bool -mpd_client_must_quote (const char *s) -{ - if (!*s) - return true; - for (; *s; s++) - if (mpd_client_must_quote_char (*s)) - return true; - return false; -} - -static void -mpd_client_quote (const char *s, struct str *output) -{ - str_append_c (output, '"'); - for (; *s; s++) - { - if (mpd_client_must_quote_char (*s)) - str_append_c (output, '\\'); - str_append_c (output, *s); - } - str_append_c (output, '"'); -} - -/// Beware that delivery of the event isn't deferred and you musn't make -/// changes to the interface while processing the event! -static void -mpd_client_add_task - (struct mpd_client *self, mpd_client_task_cb cb, void *user_data) -{ - // This only has meaning with command_list_ok_begin, and then it requires - // special handling (all in-list tasks need to be specially marked and - // later flushed if an early ACK or OK arrives). - hard_assert (!self->in_list); - - struct mpd_client_task *task = xcalloc (1, sizeof *self); - task->callback = cb; - task->user_data = user_data; - LIST_APPEND_WITH_TAIL (self->tasks, self->tasks_tail, task); -} - -/// Send a command. Remember to call mpd_client_add_task() to handle responses, -/// unless the command is being sent in a list. -static void mpd_client_send_command - (struct mpd_client *self, const char *command, ...) ATTRIBUTE_SENTINEL; - -static void -mpd_client_send_commandv (struct mpd_client *self, char **commands) -{ - // Automatically interrupt idle mode - if (self->idling) - { - poller_timer_reset (&self->timeout_timer); - - self->idling = false; - self->idling_subsystems = 0; - mpd_client_send_command (self, "noidle", NULL); - } - - struct str line; - str_init (&line); - - for (; *commands; commands++) - { - if (line.len) - str_append_c (&line, ' '); - - if (mpd_client_must_quote (*commands)) - mpd_client_quote (*commands, &line); - else - str_append (&line, *commands); - } - - if (self->on_io_hook) - self->on_io_hook (self->user_data, true, line.str); - - str_append_c (&line, '\n'); - str_append_str (&self->write_buffer, &line); - str_free (&line); - - mpd_client_update_poller (self); -} - -static void -mpd_client_send_command (struct mpd_client *self, const char *command, ...) -{ - struct str_vector v; - str_vector_init (&v); - - va_list ap; - va_start (ap, command); - for (; command; command = va_arg (ap, const char *)) - str_vector_add (&v, command); - va_end (ap); - - mpd_client_send_commandv (self, v.vector); - str_vector_free (&v); -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static void -mpd_client_list_begin (struct mpd_client *self) -{ - hard_assert (!self->in_list); - mpd_client_send_command (self, "command_list_begin", NULL); - self->in_list = true; -} - -/// End a list of commands. Remember to call mpd_client_add_task() -/// to handle the summary response. -static void -mpd_client_list_end (struct mpd_client *self) -{ - hard_assert (self->in_list); - mpd_client_send_command (self, "command_list_end", NULL); - self->in_list = false; -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static bool -mpd_resolve_subsystem (const char *name, unsigned *output) -{ - for (size_t i = 0; i < N_ELEMENTS (mpd_subsystem_names); i++) - if (!strcasecmp_ascii (name, mpd_subsystem_names[i])) - { - *output |= 1 << i; - return true; - } - return false; -} - -static void -mpd_client_on_idle_return (const struct mpd_response *response, - const struct str_vector *data, void *user_data) -{ - (void) response; - - struct mpd_client *self = user_data; - unsigned subsystems = 0; - for (size_t i = 0; i < data->len; i++) - { - char *value, *key; - if (!(key = mpd_client_parse_kv (data->vector[i], &value))) - print_debug ("%s: %s", "erroneous MPD output", data->vector[i]); - else if (strcasecmp_ascii (key, "changed")) - print_debug ("%s: %s", "unexpected idle key", key); - else if (!mpd_resolve_subsystem (value, &subsystems)) - print_debug ("%s: %s", "unknown subsystem", value); - } - - // Not resetting "idling" here, we may send an extra "noidle" no problem - if (self->on_event && subsystems) - self->on_event (subsystems, self->user_data); -} - -static void mpd_client_idle (struct mpd_client *self, unsigned subsystems); - -static void -mpd_client_on_timeout (void *user_data) -{ - struct mpd_client *self = user_data; - - // Abort and immediately restore the current idle so that MPD doesn't - // disconnect us, even though the documentation says this won't happen. - // Just sending this out should bring a dead connection down over TCP. - // TODO: set another timer to make sure we get a reply - mpd_client_idle (self, self->idling_subsystems); -} - -/// When not expecting to send any further commands, you should call this -/// in order to keep the connection alive. Or to receive updates. -static void -mpd_client_idle (struct mpd_client *self, unsigned subsystems) -{ - hard_assert (!self->in_list); - - struct str_vector v; - str_vector_init (&v); - - str_vector_add (&v, "idle"); - for (size_t i = 0; i < N_ELEMENTS (mpd_subsystem_names); i++) - if (subsystems & (1 << i)) - str_vector_add (&v, mpd_subsystem_names[i]); - - mpd_client_send_commandv (self, v.vector); - str_vector_free (&v); - - self->timeout_timer.dispatcher = mpd_client_on_timeout; - self->timeout_timer.user_data = self; - poller_timer_set (&self->timeout_timer, 5 * 60 * 1000); - - mpd_client_add_task (self, mpd_client_on_idle_return, self); - self->idling = true; - self->idling_subsystems = subsystems; -} - -// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -static void -mpd_client_finish_connection (struct mpd_client *self, int socket) -{ - set_blocking (socket, false); - self->socket = socket; - self->state = MPD_CONNECTED; - - poller_fd_init (&self->socket_event, self->poller, self->socket); - self->socket_event.dispatcher = mpd_client_on_ready; - self->socket_event.user_data = self; - - mpd_client_update_poller (self); - - if (self->on_connected) - self->on_connected (self->user_data); -} - -static void -mpd_client_destroy_connector (struct mpd_client *self) -{ - if (self->connector) - connector_free (self->connector); - free (self->connector); - self->connector = NULL; - - // Not connecting anymore - self->state = MPD_DISCONNECTED; -} - -static void -mpd_client_on_connector_failure (void *user_data) -{ - struct mpd_client *self = user_data; - mpd_client_destroy_connector (self); - mpd_client_fail (self); -} - -static void -mpd_client_on_connector_connected - (void *user_data, int socket, const char *host) -{ - (void) host; - - struct mpd_client *self = user_data; - mpd_client_destroy_connector (self); - mpd_client_finish_connection (self, socket); -} - -static bool -mpd_client_connect_unix (struct mpd_client *self, const char *address, - struct error **e) -{ - int fd = socket (AF_UNIX, SOCK_STREAM, 0); - if (fd == -1) - { - error_set (e, "%s: %s", "socket", strerror (errno)); - return false; - } - - // Expand tilde if needed - char *expanded = resolve_filename (address, xstrdup); - - struct sockaddr_un sun; - sun.sun_family = AF_UNIX; - strncpy (sun.sun_path, expanded, sizeof sun.sun_path); - sun.sun_path[sizeof sun.sun_path - 1] = 0; - - free (expanded); - - if (connect (fd, (struct sockaddr *) &sun, sizeof sun)) - { - error_set (e, "%s: %s", "connect", strerror (errno)); - return false; - } - - mpd_client_finish_connection (self, fd); - return true; -} - -static bool -mpd_client_connect (struct mpd_client *self, const char *address, - const char *service, struct error **e) -{ - hard_assert (self->state == MPD_DISCONNECTED); - - // If it looks like a path, assume it's a UNIX socket - if (strchr (address, '/')) - return mpd_client_connect_unix (self, address, e); - - struct connector *connector = xmalloc (sizeof *connector); - connector_init (connector, self->poller); - self->connector = connector; - - connector->user_data = self; - connector->on_connected = mpd_client_on_connector_connected; - connector->on_failure = mpd_client_on_connector_failure; - - connector_add_target (connector, address, service); - self->state = MPD_CONNECTING; - return true; -} |