ctrl_iface_dbus.c

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/*
 * WPA Supplicant / dbus-based control interface
 * Copyright (c) 2006, Dan Williams <[e-mail]> and Red Hat, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include <dbus/dbus.h>

#include "common.h"
#include "eloop.h"
#include "wpa.h"
#include "wpa_supplicant.h"
#include "config.h"
#include "eapol_sm.h"
#include "wpa_supplicant_i.h"
#include "ctrl_iface_dbus.h"
#include "ctrl_iface_dbus_handlers.h"
#include "l2_packet.h"
#include "preauth.h"
#include "wpa_ctrl.h"
#include "eap.h"

#define DBUS_VERSION (DBUS_VERSION_MAJOR << 8 | DBUS_VERSION_MINOR)
#define DBUS_VER(major, minor) ((major) << 8 | (minor))

#if DBUS_VERSION < DBUS_VER(1,1)
#define dbus_watch_get_unix_fd dbus_watch_get_fd
#endif


struct ctrl_iface_dbus_priv {
	DBusConnection *con;
	int should_dispatch;
	struct wpa_global *global;

	u32 next_objid;
};


static void process_watch(struct ctrl_iface_dbus_priv *iface,
			  DBusWatch *watch, eloop_event_type type)
{
	dbus_connection_ref(iface->con);

	iface->should_dispatch = 0;

	if (type == EVENT_TYPE_READ)
		dbus_watch_handle(watch, DBUS_WATCH_READABLE);
	else if (type == EVENT_TYPE_WRITE)
		dbus_watch_handle(watch, DBUS_WATCH_WRITABLE);
	else if (type == EVENT_TYPE_EXCEPTION)
		dbus_watch_handle(watch, DBUS_WATCH_ERROR);

	if (iface->should_dispatch) {
		while (dbus_connection_get_dispatch_status(iface->con) ==
		       DBUS_DISPATCH_DATA_REMAINS)
			dbus_connection_dispatch(iface->con);
		iface->should_dispatch = 0;
	}

	dbus_connection_unref(iface->con);
}


static void process_watch_exception(int sock, void *eloop_ctx, void *sock_ctx)
{
	process_watch(eloop_ctx, sock_ctx, EVENT_TYPE_EXCEPTION);
}


static void process_watch_read(int sock, void *eloop_ctx, void *sock_ctx)
{
	process_watch(eloop_ctx, sock_ctx, EVENT_TYPE_READ);
}


static void process_watch_write(int sock, void *eloop_ctx, void *sock_ctx)
{
	process_watch(eloop_ctx, sock_ctx, EVENT_TYPE_WRITE);
}


static void connection_setup_add_watch(struct ctrl_iface_dbus_priv *iface,
				       DBusWatch *watch)
{
	unsigned int flags;
	int fd;

	if (!dbus_watch_get_enabled(watch))
		return;

	flags = dbus_watch_get_flags(watch);
	fd = dbus_watch_get_unix_fd(watch);

	eloop_register_sock(fd, EVENT_TYPE_EXCEPTION, process_watch_exception,
			    iface, watch);

	if (flags & DBUS_WATCH_READABLE) {
		eloop_register_sock(fd, EVENT_TYPE_READ, process_watch_read,
				    iface, watch);
	}
	if (flags & DBUS_WATCH_WRITABLE) {
		eloop_register_sock(fd, EVENT_TYPE_WRITE, process_watch_write,
				    iface, watch);
	}

	dbus_watch_set_data(watch, iface, NULL);
}


static void connection_setup_remove_watch(struct ctrl_iface_dbus_priv *iface,
					  DBusWatch *watch)
{
	unsigned int flags;
	int fd;

	flags = dbus_watch_get_flags(watch);
	fd = dbus_watch_get_unix_fd(watch);

	eloop_unregister_sock(fd, EVENT_TYPE_EXCEPTION);

	if (flags & DBUS_WATCH_READABLE)
		eloop_unregister_sock(fd, EVENT_TYPE_READ);
	if (flags & DBUS_WATCH_WRITABLE)
		eloop_unregister_sock(fd, EVENT_TYPE_WRITE);

	dbus_watch_set_data(watch, NULL, NULL);
}


static dbus_bool_t add_watch(DBusWatch *watch, void *data)
{
	connection_setup_add_watch(data, watch);
	return TRUE;
}


static void remove_watch(DBusWatch *watch, void *data)
{
	connection_setup_remove_watch(data, watch);
}


static void watch_toggled(DBusWatch *watch, void *data)
{
	if (dbus_watch_get_enabled(watch))
		add_watch(watch, data);
	else
		remove_watch(watch, data);
}


static void process_timeout(void *eloop_ctx, void *sock_ctx)
{
	DBusTimeout *timeout = sock_ctx;

	dbus_timeout_handle(timeout);
}


static void connection_setup_add_timeout(struct ctrl_iface_dbus_priv *iface,
					 DBusTimeout *timeout)
{
	if (!dbus_timeout_get_enabled(timeout))
		return;

	eloop_register_timeout(0, dbus_timeout_get_interval(timeout) * 1000,
			       process_timeout, iface, timeout);

	dbus_timeout_set_data(timeout, iface, NULL);
}


static void connection_setup_remove_timeout(struct ctrl_iface_dbus_priv *iface,
					    DBusTimeout *timeout)
{
	eloop_cancel_timeout(process_timeout, iface, timeout);
	dbus_timeout_set_data(timeout, NULL, NULL);
}


static dbus_bool_t add_timeout(DBusTimeout *timeout, void *data)
{
	if (!dbus_timeout_get_enabled(timeout))
		return TRUE;

	connection_setup_add_timeout(data, timeout);

	return TRUE;
}


static void remove_timeout(DBusTimeout *timeout, void *data)
{
	connection_setup_remove_timeout(data, timeout);
}


static void timeout_toggled(DBusTimeout *timeout, void *data)
{
	if (dbus_timeout_get_enabled(timeout))
		add_timeout(timeout, data);
	else
		remove_timeout(timeout, data);
}


static void process_wakeup_main(int sig, void *eloop_ctx, void *signal_ctx)
{
	struct ctrl_iface_dbus_priv *iface = signal_ctx;

	if (sig != SIGPOLL || !iface->con)
		return;

	if (dbus_connection_get_dispatch_status(iface->con) !=
	    DBUS_DISPATCH_DATA_REMAINS)
		return;

	/* Only dispatch once - we do not want to starve other events */
	dbus_connection_ref(iface->con);
	dbus_connection_dispatch(iface->con);
	dbus_connection_unref(iface->con);
}


/**
 * wakeup_main - Attempt to wake our mainloop up
 * @data: dbus control interface private data
 *
 * Try to wake up the main eloop so it will process
 * dbus events that may have happened.
 */
static void wakeup_main(void *data)
{
	struct ctrl_iface_dbus_priv *iface = data;

	/* Use SIGPOLL to break out of the eloop select() */
	raise(SIGPOLL);
	iface->should_dispatch = 1;
}


/**
 * connection_setup_wakeup_main - Tell dbus about our wakeup_main function
 * @iface: dbus control interface private data
 * Returns: 0 on success, -1 on failure
 *
 * Register our wakeup_main handler with dbus
 */
static int connection_setup_wakeup_main(struct ctrl_iface_dbus_priv *iface)
{
	if (eloop_register_signal(SIGPOLL, process_wakeup_main, iface))
		return -1;

	dbus_connection_set_wakeup_main_function(iface->con, wakeup_main,
						 iface, NULL);

	return 0;
}


/**
 * wpa_supplicant_dbus_next_objid - Return next available object id
 * @iface: dbus control interface private data
 * Returns: Object id
 */
u32 wpa_supplicant_dbus_next_objid (struct ctrl_iface_dbus_priv *iface)
{
	return iface->next_objid++;
}


/**
 * wpas_dbus_decompose_object_path - Decompose an interface object path into parts
 * @path: The dbus object path
 * @network: (out) the configured network this object path refers to, if any
 * @bssid: (out) the scanned bssid this object path refers to, if any
 * Returns: The object path of the network interface this path refers to
 *
 * For a given object path, decomposes the object path into object id, network,
 * and BSSID parts, if those parts exist.
 */
char * wpas_dbus_decompose_object_path(const char *path, char **network,
				       char **bssid)
{
	const unsigned int dev_path_prefix_len =
		strlen(WPAS_DBUS_PATH_INTERFACES "/");
	char *obj_path_only;
	char *next_sep;

	/* Be a bit paranoid about path */
	if (!path || strncmp(path, WPAS_DBUS_PATH_INTERFACES "/",
			     dev_path_prefix_len))
		return NULL;

	/* Ensure there's something at the end of the path */
	if ((path + dev_path_prefix_len)[0] == '\0')
		return NULL;

	obj_path_only = strdup(path);
	if (obj_path_only == NULL)
		return NULL;

	next_sep = strchr(obj_path_only + dev_path_prefix_len, '/');
	if (next_sep != NULL) {
		const char *net_part = strstr(next_sep,
					      WPAS_DBUS_NETWORKS_PART "/");
		const char *bssid_part = strstr(next_sep,
						WPAS_DBUS_BSSIDS_PART "/");

		if (network && net_part) {
			/* Deal with a request for a configured network */
			const char *net_name = net_part +
				strlen(WPAS_DBUS_NETWORKS_PART "/");
			*network = NULL;
			if (strlen(net_name))
				*network = strdup(net_name);
		} else if (bssid && bssid_part) {
			/* Deal with a request for a scanned BSSID */
			const char *bssid_name = bssid_part +
				strlen(WPAS_DBUS_BSSIDS_PART "/");
			if (strlen(bssid_name))
				*bssid = strdup(bssid_name);
			else
				*bssid = NULL;
		}

		/* Cut off interface object path before "/" */
		*next_sep = '\0';
	}

	return obj_path_only;
}


/**
 * wpas_dbus_new_invalid_iface_error - Return a new invalid interface error message
 * @message: Pointer to incoming dbus message this error refers to
 * Returns: A dbus error message
 *
 * Convenience function to create and return an invalid interface error
 */
DBusMessage * wpas_dbus_new_invalid_iface_error(DBusMessage *message)
{
	return dbus_message_new_error(message, WPAS_ERROR_INVALID_IFACE,
				      "wpa_supplicant knows nothing about "
				      "this interface.");
}


/**
 * wpas_dbus_new_invalid_network_error - Return a new invalid network error message
 * @message: Pointer to incoming dbus message this error refers to
 * Returns: a dbus error message
 *
 * Convenience function to create and return an invalid network error
 */
DBusMessage * wpas_dbus_new_invalid_network_error(DBusMessage *message)
{
	return dbus_message_new_error(message, WPAS_ERROR_INVALID_NETWORK,
				      "The requested network does not exist.");
}


/**
 * wpas_dbus_new_invalid_bssid_error - Return a new invalid bssid error message
 * @message: Pointer to incoming dbus message this error refers to
 * Returns: a dbus error message
 *
 * Convenience function to create and return an invalid bssid error
 */
static DBusMessage * wpas_dbus_new_invalid_bssid_error(DBusMessage *message)
{
	return dbus_message_new_error(message, WPAS_ERROR_INVALID_BSSID,
				      "The BSSID requested was invalid.");
}


/**
 * wpas_dispatch_network_method - dispatch messages for configured networks
 * @message: the incoming dbus message
 * @wpa_s: a network interface's data
 * @network_id: id of the configured network we're interested in
 * Returns: a reply dbus message, or a dbus error message
 *
 * This function dispatches all incoming dbus messages for configured networks.
 */
static DBusMessage * wpas_dispatch_network_method(DBusMessage *message,
						  struct wpa_supplicant *wpa_s,
						  int network_id)
{
	DBusMessage *reply = NULL;
	const char *method = dbus_message_get_member(message);
	struct wpa_ssid *ssid;

	ssid = wpa_config_get_network(wpa_s->conf, network_id);
	if (ssid == NULL)
		return wpas_dbus_new_invalid_network_error(message);

	if (!strcmp(method, "set"))
		reply = wpas_dbus_iface_set_network(message, wpa_s, ssid);
	else if (!strcmp(method, "enable"))
		reply = wpas_dbus_iface_enable_network(message, wpa_s, ssid);
	else if (!strcmp(method, "disable"))
		reply = wpas_dbus_iface_disable_network(message, wpa_s, ssid);

	return reply;
}


/**
 * wpas_dispatch_bssid_method - dispatch messages for scanned networks
 * @message: the incoming dbus message
 * @wpa_s: a network interface's data
 * @bssid: bssid of the scanned network we're interested in
 * Returns: a reply dbus message, or a dbus error message
 *
 * This function dispatches all incoming dbus messages for scanned networks.
 */
static DBusMessage * wpas_dispatch_bssid_method(DBusMessage *message,
						struct wpa_supplicant *wpa_s,
						const char *bssid)
{
	DBusMessage *reply = NULL;
	const char *method = dbus_message_get_member(message);
	struct wpa_scan_result * res = NULL;
	int i;

	/* Ensure we actually have scan data */
	if (wpa_s->scan_results == NULL &&
	    wpa_supplicant_get_scan_results(wpa_s) < 0) {
		reply = wpas_dbus_new_invalid_bssid_error(message);
		goto out;
	}

	/* Find the bssid's scan data */
	for (i = 0; i < wpa_s->num_scan_results; i++) {
		struct wpa_scan_result * search_res = &wpa_s->scan_results[i];
		char mac_str[18];

		memset(mac_str, 0, sizeof(mac_str));
		snprintf(mac_str, sizeof(mac_str) - 1, WPAS_DBUS_BSSID_FORMAT,
			 MAC2STR(search_res->bssid));
		if (!strcmp(bssid, mac_str)) {
			res = search_res;
		}
	}

	if (!res) {
		reply = wpas_dbus_new_invalid_bssid_error(message);
		goto out;
	}

	/* Dispatch the method call against the scanned bssid */
	if (!strcmp(method, "properties"))
		reply = wpas_dbus_bssid_properties(message, wpa_s, res);

out:
	return reply;
}


/**
 * wpas_iface_message_handler - Dispatch messages for interfaces or networks
 * @connection: Connection to the system message bus
 * @message: An incoming dbus message
 * @user_data: A pointer to a dbus control interface data structure
 * Returns: Whether or not the message was handled
 *
 * This function dispatches all incoming dbus messages for network interfaces,
 * or objects owned by them, such as scanned BSSIDs and configured networks.
 */
static DBusHandlerResult wpas_iface_message_handler(DBusConnection *connection,
						    DBusMessage *message,
						    void *user_data)
{
	struct wpa_supplicant *wpa_s = user_data;
	const char *method = dbus_message_get_member(message);
	const char *path = dbus_message_get_path(message);
	const char *msg_interface = dbus_message_get_interface(message);
	char *iface_obj_path = NULL;
	char *network = NULL;
	char *bssid = NULL;
	DBusMessage *reply = NULL;

	/* Caller must specify a message interface */
	if (!msg_interface)
		goto out;

	iface_obj_path = wpas_dbus_decompose_object_path(path, &network,
	                                                 &bssid);
	if (iface_obj_path == NULL) {
		reply = wpas_dbus_new_invalid_iface_error(message);
		goto out;
	}

	/* Make sure the message's object path actually refers to the
	 * wpa_supplicant structure it's supposed to (which is wpa_s)
	 */
	if (wpa_supplicant_get_iface_by_dbus_path(wpa_s->global,
	                                          iface_obj_path) != wpa_s) {
		reply = wpas_dbus_new_invalid_iface_error(message);
		goto out;
	}

	if (network && !strcmp(msg_interface, WPAS_DBUS_IFACE_NETWORK)) {
		/* A method for one of this interface's configured networks */
		int nid = strtoul(network, NULL, 10);
		if (errno != EINVAL)
			reply = wpas_dispatch_network_method(message, wpa_s,
							     nid);
		else
			reply = wpas_dbus_new_invalid_network_error(message);
	} else if (bssid && !strcmp(msg_interface, WPAS_DBUS_IFACE_BSSID)) {
		/* A method for one of this interface's scanned BSSIDs */
		reply = wpas_dispatch_bssid_method(message, wpa_s, bssid);
	} else if (!strcmp(msg_interface, WPAS_DBUS_IFACE_INTERFACE)) {
		/* A method for an interface only. */
		if (!strcmp(method, "scan"))
			reply = wpas_dbus_iface_scan(message, wpa_s);
		else if (!strcmp(method, "scanResults"))