mpd/src/command.c

/*
 * Copyright (C) 2003-2012 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "command.h"
#include "QueueCommands.hxx"
#include "PlayerCommands.hxx"
#include "PlaylistCommands.hxx"
#include "DatabaseCommands.hxx"
#include "OutputCommands.hxx"
#include "StickerCommands.hxx"
#include "MessageCommands.hxx"
#include "CommandError.h"
#include "protocol/argparser.h"
#include "protocol/result.h"
#include "time_print.h"
#include "ls.h"
#include "uri.h"
#include "decoder_print.h"
#include "directory.h"
#include "update.h"
#include "volume.h"
#include "stats.h"
#include "permission.h"
#include "tokenizer.h"
#include "stored_playlist.h"
#include "tag.h"
#include "client.h"
#include "client_idle.h"
#include "client_file.h"
#include "tag_print.h"
#include "idle.h"
#include "mapper.h"
#include "song.h"
#include "song_print.h"

#ifdef ENABLE_SQLITE
#include "sticker.h"
#endif

#include <assert.h>
#include <string.h>

/*
 * The most we ever use is for search/find, and that limits it to the
 * number of tags we can have.  Add one for the command, and one extra
 * to catch errors clients may send us
 */
#define COMMAND_ARGV_MAX	(2+(TAG_NUM_OF_ITEM_TYPES*2))

/* if min: -1 don't check args *
 * if max: -1 no max args      */
struct command {
	const char *cmd;
	unsigned permission;
	int min;
	int max;
	enum command_return (*handler)(struct client *client, int argc, char **argv);
};

static void
print_spl_list(struct client *client, GPtrArray *list)
{
	for (unsigned i = 0; i < list->len; ++i) {
		struct stored_playlist_info *playlist =
			g_ptr_array_index(list, i);

		client_printf(client, "playlist: %s\n", playlist->name);

		if (playlist->mtime > 0)
			time_print(client, "Last-Modified", playlist->mtime);
	}
}

static enum command_return
handle_urlhandlers(struct client *client,
		   G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	if (client_is_local(client))
		client_puts(client, "handler: file://\n");
	print_supported_uri_schemes(client);
	return COMMAND_RETURN_OK;
}

static enum command_return
handle_decoders(struct client *client,
		G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	decoder_list_print(client);
	return COMMAND_RETURN_OK;
}

static enum command_return
handle_tagtypes(struct client *client,
		G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	tag_print_types(client);
	return COMMAND_RETURN_OK;
}

static enum command_return
handle_kill(G_GNUC_UNUSED struct client *client,
	    G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	return COMMAND_RETURN_KILL;
}

static enum command_return
handle_close(G_GNUC_UNUSED struct client *client,
	     G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	return COMMAND_RETURN_CLOSE;
}

static enum command_return
handle_lsinfo(struct client *client, int argc, char *argv[])
{
	const char *uri;

	if (argc == 2)
		uri = argv[1];
	else
		/* default is root directory */
		uri = "";

	if (strncmp(uri, "file:///", 8) == 0) {
		/* print information about an arbitrary local file */
		const char *path = uri + 7;

		GError *error = NULL;
		if (!client_allow_file(client, path, &error))
			return print_error(client, error);

		struct song *song = song_file_load(path, NULL);
		if (song == NULL) {
			command_error(client, ACK_ERROR_NO_EXIST,
				      "No such file");
			return COMMAND_RETURN_ERROR;
		}

		song_print_info(client, song);
		song_free(song);
		return COMMAND_RETURN_OK;
	}

	enum command_return result = handle_lsinfo2(client, argc, argv);
	if (result != COMMAND_RETURN_OK)
		return result;

	if (isRootDirectory(uri)) {
		GPtrArray *list = spl_list(NULL);
		if (list != NULL) {
			print_spl_list(client, list);
			spl_list_free(list);
		}
	}

	return COMMAND_RETURN_OK;
}

static enum command_return
handle_update(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
{
	const char *path = NULL;
	unsigned ret;

	assert(argc <= 2);
	if (argc == 2) {
		path = argv[1];

		if (*path == 0 || strcmp(path, "/") == 0)
			/* backwards compatibility with MPD 0.15 */
			path = NULL;
		else if (!uri_safe_local(path)) {
			command_error(client, ACK_ERROR_ARG,
				      "Malformed path");
			return COMMAND_RETURN_ERROR;
		}
	}

	ret = update_enqueue(path, false);
	if (ret > 0) {
		client_printf(client, "updating_db: %i\n", ret);
		return COMMAND_RETURN_OK;
	} else {
		command_error(client, ACK_ERROR_UPDATE_ALREADY,
			      "already updating");
		return COMMAND_RETURN_ERROR;
	}
}

static enum command_return
handle_rescan(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
{
	const char *path = NULL;
	unsigned ret;

	assert(argc <= 2);
	if (argc == 2) {
		path = argv[1];

		if (!uri_safe_local(path)) {
			command_error(client, ACK_ERROR_ARG,
				      "Malformed path");
			return COMMAND_RETURN_ERROR;
		}
	}

	ret = update_enqueue(path, true);
	if (ret > 0) {
		client_printf(client, "updating_db: %i\n", ret);
		return COMMAND_RETURN_OK;
	} else {
		command_error(client, ACK_ERROR_UPDATE_ALREADY,
			      "already updating");
		return COMMAND_RETURN_ERROR;
	}
}

static enum command_return
handle_setvol(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
{
	unsigned level;
	bool success;

	if (!check_unsigned(client, &level, argv[1]))
		return COMMAND_RETURN_ERROR;

	if (level > 100) {
		command_error(client, ACK_ERROR_ARG, "Invalid volume value");
		return COMMAND_RETURN_ERROR;
	}

	success = volume_level_change(level);
	if (!success) {
		command_error(client, ACK_ERROR_SYSTEM,
			      "problems setting volume");
		return COMMAND_RETURN_ERROR;
	}

	return COMMAND_RETURN_OK;
}

static enum command_return
handle_stats(struct client *client,
	     G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	stats_print(client);
	return COMMAND_RETURN_OK;
}

static enum command_return
handle_ping(G_GNUC_UNUSED struct client *client,
	    G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	return COMMAND_RETURN_OK;
}

static enum command_return
handle_password(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
{
	unsigned permission = 0;

	if (getPermissionFromPassword(argv[1], &permission) < 0) {
		command_error(client, ACK_ERROR_PASSWORD, "incorrect password");
		return COMMAND_RETURN_ERROR;
	}

	client_set_permission(client, permission);

	return COMMAND_RETURN_OK;
}

/* don't be fooled, this is the command handler for "commands" command */
static enum command_return
handle_commands(struct client *client,
		G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[]);

static enum command_return
handle_not_commands(struct client *client,
		    G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[]);

static enum command_return
handle_config(struct client *client,
	      G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	if (!client_is_local(client)) {
		command_error(client, ACK_ERROR_PERMISSION,
			      "Command only permitted to local clients");
		return COMMAND_RETURN_ERROR;
	}

	const char *path = mapper_get_music_directory_utf8();
	if (path != NULL)
		client_printf(client, "music_directory: %s\n", path);

	return COMMAND_RETURN_OK;
}

static enum command_return
handle_idle(struct client *client,
	    G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
        unsigned flags = 0, j;
        int i;
        const char *const* idle_names;

        idle_names = idle_get_names();
        for (i = 1; i < argc; ++i) {
                if (!argv[i])
                        continue;

                for (j = 0; idle_names[j]; ++j) {
                        if (!g_ascii_strcasecmp(argv[i], idle_names[j])) {
                                flags |= (1 << j);
                        }
                }
        }

        /* No argument means that the client wants to receive everything */
        if (flags == 0)
                flags = ~0;

	/* enable "idle" mode on this client */
	client_idle_wait(client, flags);

	/* return value is "1" so the caller won't print "OK" */
	return 1;
}

/**
 * The command registry.
 *
 * This array must be sorted!
 */
static const struct command commands[] = {
	{ "add", PERMISSION_ADD, 1, 1, handle_add },
	{ "addid", PERMISSION_ADD, 1, 2, handle_addid },
	{ "channels", PERMISSION_READ, 0, 0, handle_channels },
	{ "clear", PERMISSION_CONTROL, 0, 0, handle_clear },
	{ "clearerror", PERMISSION_CONTROL, 0, 0, handle_clearerror },
	{ "close", PERMISSION_NONE, -1, -1, handle_close },
	{ "commands", PERMISSION_NONE, 0, 0, handle_commands },
	{ "config", PERMISSION_ADMIN, 0, 0, handle_config },
	{ "consume", PERMISSION_CONTROL, 1, 1, handle_consume },
	{ "count", PERMISSION_READ, 2, -1, handle_count },
	{ "crossfade", PERMISSION_CONTROL, 1, 1, handle_crossfade },
	{ "currentsong", PERMISSION_READ, 0, 0, handle_currentsong },
	{ "decoders", PERMISSION_READ, 0, 0, handle_decoders },
	{ "delete", PERMISSION_CONTROL, 1, 1, handle_delete },
	{ "deleteid", PERMISSION_CONTROL, 1, 1, handle_deleteid },
	{ "disableoutput", PERMISSION_ADMIN, 1, 1, handle_disableoutput },
	{ "enableoutput", PERMISSION_ADMIN, 1, 1, handle_enableoutput },
	{ "find", PERMISSION_READ, 2, -1, handle_find },
	{ "findadd", PERMISSION_READ, 2, -1, handle_findadd},
	{ "idle", PERMISSION_READ, 0, -1, handle_idle },
	{ "kill", PERMISSION_ADMIN, -1, -1, handle_kill },
	{ "list", PERMISSION_READ, 1, -1, handle_list },
	{ "listall", PERMISSION_READ, 0, 1, handle_listall },
	{ "listallinfo", PERMISSION_READ, 0, 1, handle_listallinfo },
	{ "listplaylist", PERMISSION_READ, 1, 1, handle_listplaylist },
	{ "listplaylistinfo", PERMISSION_READ, 1, 1, handle_listplaylistinfo },
	{ "listplaylists", PERMISSION_READ, 0, 0, handle_listplaylists },
	{ "load", PERMISSION_ADD, 1, 2, handle_load },
	{ "lsinfo", PERMISSION_READ, 0, 1, handle_lsinfo },
	{ "mixrampdb", PERMISSION_CONTROL, 1, 1, handle_mixrampdb },
	{ "mixrampdelay", PERMISSION_CONTROL, 1, 1, handle_mixrampdelay },
	{ "move", PERMISSION_CONTROL, 2, 2, handle_move },
	{ "moveid", PERMISSION_CONTROL, 2, 2, handle_moveid },
	{ "next", PERMISSION_CONTROL, 0, 0, handle_next },
	{ "notcommands", PERMISSION_NONE, 0, 0, handle_not_commands },
	{ "outputs", PERMISSION_READ, 0, 0, handle_devices },
	{ "password", PERMISSION_NONE, 1, 1, handle_password },
	{ "pause", PERMISSION_CONTROL, 0, 1, handle_pause },
	{ "ping", PERMISSION_NONE, 0, 0, handle_ping },
	{ "play", PERMISSION_CONTROL, 0, 1, handle_play },
	{ "playid", PERMISSION_CONTROL, 0, 1, handle_playid },
	{ "playlist", PERMISSION_READ, 0, 0, handle_playlist },
	{ "playlistadd", PERMISSION_CONTROL, 2, 2, handle_playlistadd },
	{ "playlistclear", PERMISSION_CONTROL, 1, 1, handle_playlistclear },
	{ "playlistdelete", PERMISSION_CONTROL, 2, 2, handle_playlistdelete },
	{ "playlistfind", PERMISSION_READ, 2, -1, handle_playlistfind },
	{ "playlistid", PERMISSION_READ, 0, 1, handle_playlistid },
	{ "playlistinfo", PERMISSION_READ, 0, 1, handle_playlistinfo },
	{ "playlistmove", PERMISSION_CONTROL, 3, 3, handle_playlistmove },
	{ "playlistsearch", PERMISSION_READ, 2, -1, handle_playlistsearch },
	{ "plchanges", PERMISSION_READ, 1, 1, handle_plchanges },
	{ "plchangesposid", PERMISSION_READ, 1, 1, handle_plchangesposid },
	{ "previous", PERMISSION_CONTROL, 0, 0, handle_previous },
	{ "prio", PERMISSION_CONTROL, 2, -1, handle_prio },
	{ "prioid", PERMISSION_CONTROL, 2, -1, handle_prioid },
	{ "random", PERMISSION_CONTROL, 1, 1, handle_random },
	{ "readmessages", PERMISSION_READ, 0, 0, handle_read_messages },
	{ "rename", PERMISSION_CONTROL, 2, 2, handle_rename },
	{ "repeat", PERMISSION_CONTROL, 1, 1, handle_repeat },
	{ "replay_gain_mode", PERMISSION_CONTROL, 1, 1,
	  handle_replay_gain_mode },
	{ "replay_gain_status", PERMISSION_READ, 0, 0,
	  handle_replay_gain_status },
	{ "rescan", PERMISSION_CONTROL, 0, 1, handle_rescan },
	{ "rm", PERMISSION_CONTROL, 1, 1, handle_rm },
	{ "save", PERMISSION_CONTROL, 1, 1, handle_save },
	{ "search", PERMISSION_READ, 2, -1, handle_search },
	{ "searchadd", PERMISSION_ADD, 2, -1, handle_searchadd },
	{ "searchaddpl", PERMISSION_CONTROL, 3, -1, handle_searchaddpl },
	{ "seek", PERMISSION_CONTROL, 2, 2, handle_seek },
	{ "seekcur", PERMISSION_CONTROL, 1, 1, handle_seekcur },
	{ "seekid", PERMISSION_CONTROL, 2, 2, handle_seekid },
	{ "sendmessage", PERMISSION_CONTROL, 2, 2, handle_send_message },
	{ "setvol", PERMISSION_CONTROL, 1, 1, handle_setvol },
	{ "shuffle", PERMISSION_CONTROL, 0, 1, handle_shuffle },
	{ "single", PERMISSION_CONTROL, 1, 1, handle_single },
	{ "stats", PERMISSION_READ, 0, 0, handle_stats },
	{ "status", PERMISSION_READ, 0, 0, handle_status },
#ifdef ENABLE_SQLITE
	{ "sticker", PERMISSION_ADMIN, 3, -1, handle_sticker },
#endif
	{ "stop", PERMISSION_CONTROL, 0, 0, handle_stop },
	{ "subscribe", PERMISSION_READ, 1, 1, handle_subscribe },
	{ "swap", PERMISSION_CONTROL, 2, 2, handle_swap },
	{ "swapid", PERMISSION_CONTROL, 2, 2, handle_swapid },
	{ "tagtypes", PERMISSION_READ, 0, 0, handle_tagtypes },
	{ "unsubscribe", PERMISSION_READ, 1, 1, handle_unsubscribe },
	{ "update", PERMISSION_CONTROL, 0, 1, handle_update },
	{ "urlhandlers", PERMISSION_READ, 0, 0, handle_urlhandlers },
};

static const unsigned num_commands = sizeof(commands) / sizeof(commands[0]);

static bool
command_available(G_GNUC_UNUSED const struct command *cmd)
{
#ifdef ENABLE_SQLITE
	if (strcmp(cmd->cmd, "sticker") == 0)
		return sticker_enabled();
#endif

	return true;
}

/* don't be fooled, this is the command handler for "commands" command */
static enum command_return
handle_commands(struct client *client,
		G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	const unsigned permission = client_get_permission(client);
	const struct command *cmd;

	for (unsigned i = 0; i < num_commands; ++i) {
		cmd = &commands[i];

		if (cmd->permission == (permission & cmd->permission) &&
		    command_available(cmd))
			client_printf(client, "command: %s\n", cmd->cmd);
	}

	return COMMAND_RETURN_OK;
}

static enum command_return
handle_not_commands(struct client *client,
		    G_GNUC_UNUSED int argc, G_GNUC_UNUSED char *argv[])
{
	const unsigned permission = client_get_permission(client);
	const struct command *cmd;

	for (unsigned i = 0; i < num_commands; ++i) {
		cmd = &commands[i];

		if (cmd->permission != (permission & cmd->permission))
			client_printf(client, "command: %s\n", cmd->cmd);
	}

	return COMMAND_RETURN_OK;
}

void command_init(void)
{
#ifndef NDEBUG
	/* ensure that the command list is sorted */
	for (unsigned i = 0; i < num_commands - 1; ++i)
		assert(strcmp(commands[i].cmd, commands[i + 1].cmd) < 0);
#endif
}

void command_finish(void)
{
}

static const struct command *
command_lookup(const char *name)
{
	unsigned a = 0, b = num_commands, i;
	int cmp;

	/* binary search */
	do {
		i = (a + b) / 2;

		cmp = strcmp(name, commands[i].cmd);
		if (cmp == 0)
			return &commands[i];
		else if (cmp < 0)
			b = i;
		else if (cmp > 0)
			a = i + 1;
	} while (a < b);

	return NULL;
}

static bool
command_check_request(const struct command *cmd, struct client *client,
		      unsigned permission, int argc, char *argv[])
{
	int min = cmd->min + 1;
	int max = cmd->max + 1;

	if (cmd->permission != (permission & cmd->permission)) {
		if (client != NULL)
			command_error(client, ACK_ERROR_PERMISSION,
				      "you don't have permission for \"%s\"",
				      cmd->cmd);
		return false;
	}

	if (min == 0)
		return true;

	if (min == max && max != argc) {
		if (client != NULL)
			command_error(client, ACK_ERROR_ARG,
				      "wrong number of arguments for \"%s\"",
				      argv[0]);
		return false;
	} else if (argc < min) {
		if (client != NULL)
			command_error(client, ACK_ERROR_ARG,
				      "too few arguments for \"%s\"", argv[0]);
		return false;
	} else if (argc > max && max /* != 0 */ ) {
		if (client != NULL)
			command_error(client, ACK_ERROR_ARG,
				      "too many arguments for \"%s\"", argv[0]);
		return false;
	} else
		return true;
}

static const struct command *
command_checked_lookup(struct client *client, unsigned permission,
		       int argc, char *argv[])
{
	const struct command *cmd;

	current_command = "";

	if (argc == 0)
		return NULL;

	cmd = command_lookup(argv[0]);
	if (cmd == NULL) {
		if (client != NULL)
			command_error(client, ACK_ERROR_UNKNOWN,
				      "unknown command \"%s\"", argv[0]);
		return NULL;
	}

	current_command = cmd->cmd;

	if (!command_check_request(cmd, client, permission, argc, argv))
		return NULL;

	return cmd;
}

enum command_return
command_process(struct client *client, unsigned num, char *line)
{
	GError *error = NULL;
	int argc;
	char *argv[COMMAND_ARGV_MAX] = { NULL };
	const struct command *cmd;
	enum command_return ret = COMMAND_RETURN_ERROR;

	command_list_num = num;

	/* get the command name (first word on the line) */

	argv[0] = tokenizer_next_word(&line, &error);
	if (argv[0] == NULL) {
		current_command = "";
		if (*line == 0)
			command_error(client, ACK_ERROR_UNKNOWN,
				      "No command given");
		else {
			command_error(client, ACK_ERROR_UNKNOWN,
				      "%s", error->message);
			g_error_free(error);
		}
		current_command = NULL;

		return COMMAND_RETURN_ERROR;
	}

	argc = 1;

	/* now parse the arguments (quoted or unquoted) */

	while (argc < (int)G_N_ELEMENTS(argv) &&
	       (argv[argc] =
		tokenizer_next_param(&line, &error)) != NULL)
		++argc;

	/* some error checks; we have to set current_command because
	   command_error() expects it to be set */

	current_command = argv[0];

	if (argc >= (int)G_N_ELEMENTS(argv)) {
		command_error(client, ACK_ERROR_ARG, "Too many arguments");
		current_command = NULL;
		return COMMAND_RETURN_ERROR;
	}

	if (*line != 0) {
		command_error(client, ACK_ERROR_ARG,
			      "%s", error->message);
		current_command = NULL;
		g_error_free(error);
		return COMMAND_RETURN_ERROR;
	}

	/* look up and invoke the command handler */

	cmd = command_checked_lookup(client, client_get_permission(client),
				     argc, argv);
	if (cmd)
		ret = cmd->handler(client, argc, argv);

	current_command = NULL;
	command_list_num = 0;

	return ret;
}