Merge branch 'readme-errata'

[thirdparty/strongswan.git] / src / frontends / android / app / src / main / jni / libandroidbridge / backend / android_service.c

/*
 * Copyright (C) 2010-2017 Tobias Brunner
 * Copyright (C) 2012 Giuliano Grassi
 * Copyright (C) 2012 Ralf Sager
 * HSR Hochschule fuer Technik Rapperswil
 *
 * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * 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.
 */

#include <errno.h>
#include <unistd.h>

#include "android_service.h"
#include "android_dns_proxy.h"
#include "../charonservice.h"
#include "../vpnservice_builder.h"

#include <daemon.h>
#include <library.h>
#include <ipsec.h>
#include <processing/jobs/callback_job.h>
#include <threading/rwlock.h>
#include <threading/thread.h>

typedef struct private_android_service_t private_android_service_t;

/**
 * private data of Android service
 */
struct private_android_service_t {

	/**
	 * public interface
	 */
	android_service_t public;

	/**
	 * credential set
	 */
	android_creds_t *creds;

	/**
	 * current IKE_SA
	 */
	ike_sa_t *ike_sa;

	/**
	 * configuration setttings
	 */
	settings_t *settings;

	/**
	 * lock to safely access the TUN device fd
	 */
	rwlock_t *lock;

	/**
	 * TUN device file descriptor
	 */
	int tunfd;

	/**
	 * MTU of TUN device
	 */
	int mtu;

	/**
	 * DNS proxy
	 */
	android_dns_proxy_t *dns_proxy;

	/**
	 * Whether to use the DNS proxy or not
	 */
	bool use_dns_proxy;
};

/**
 * Outbound callback
 */
static void send_esp(void *data, esp_packet_t *packet)
{
	charon->sender->send_no_marker(charon->sender, (packet_t*)packet);
}

/**
 * Inbound callback
 */
static void deliver_plain(private_android_service_t *this,
						  ip_packet_t *packet)
{
	chunk_t encoding;
	ssize_t len;

	encoding = packet->get_encoding(packet);

	this->lock->read_lock(this->lock);
	if (this->tunfd < 0)
	{	/* the TUN device is already closed */
		this->lock->unlock(this->lock);
		packet->destroy(packet);
		return;
	}
	len = write(this->tunfd, encoding.ptr, encoding.len);
	this->lock->unlock(this->lock);

	if (len < 0 || len != encoding.len)
	{
		DBG1(DBG_DMN, "failed to write packet to TUN device: %s",
			 strerror(errno));
	}
	packet->destroy(packet);
}

/**
 * Receiver callback
 */
static void receiver_esp_cb(void *data, packet_t *packet)
{
	esp_packet_t *esp_packet;

	esp_packet = esp_packet_create_from_packet(packet);
	ipsec->processor->queue_inbound(ipsec->processor, esp_packet);
}

/**
 * Job handling outbound plaintext packets
 */
static job_requeue_t handle_plain(private_android_service_t *this)
{
	ip_packet_t *packet;
	chunk_t raw;
	fd_set set;
	ssize_t len;
	int tunfd;
	bool old, dns_proxy;
	timeval_t tv = {
		/* check every second if tunfd is still valid */
		.tv_sec = 1,
	};

	FD_ZERO(&set);

	this->lock->read_lock(this->lock);
	if (this->tunfd < 0)
	{	/* the TUN device is already closed */
		this->lock->unlock(this->lock);
		return JOB_REQUEUE_NONE;
	}
	tunfd = this->tunfd;
	FD_SET(tunfd, &set);
	/* cache this while we have the lock */
	dns_proxy = this->use_dns_proxy;
	this->lock->unlock(this->lock);

	old = thread_cancelability(TRUE);
	len = select(tunfd + 1, &set, NULL, NULL, &tv);
	thread_cancelability(old);

	if (len < 0)
	{
		if (errno == EBADF)
		{	/* the TUN device got closed just before calling select(), retry */
			return JOB_REQUEUE_FAIR;
		}
		DBG1(DBG_DMN, "select on TUN device failed: %s", strerror(errno));
		return JOB_REQUEUE_NONE;
	}
	else if (len == 0)
	{	/* timeout, check again right away */
		return JOB_REQUEUE_DIRECT;
	}

	raw = chunk_alloc(this->mtu);
	len = read(tunfd, raw.ptr, raw.len);
	if (len < 0)
	{
		DBG1(DBG_DMN, "reading from TUN device failed: %s", strerror(errno));
		chunk_free(&raw);
		return JOB_REQUEUE_FAIR;
	}
	raw.len = len;

	packet = ip_packet_create(raw);
	if (packet)
	{
		if (!dns_proxy || !this->dns_proxy->handle(this->dns_proxy, packet))
		{
			ipsec->processor->queue_outbound(ipsec->processor, packet);
		}
	}
	else
	{
		DBG1(DBG_DMN, "invalid IP packet read from TUN device");
	}
	return JOB_REQUEUE_DIRECT;
}

/**
 * Add a route to the TUN device builder
 */
static bool add_route(vpnservice_builder_t *builder, host_t *net,
					  uint8_t prefix)
{
	/* if route is 0.0.0.0/0, split it into two routes 0.0.0.0/1 and
	 * 128.0.0.0/1 because otherwise it would conflict with the current default
	 * route.  likewise for IPv6 with ::/0. */
	if (net->is_anyaddr(net) && prefix == 0)
	{
		bool success;

		success = add_route(builder, net, 1);
		if (net->get_family(net) == AF_INET)
		{
			net = host_create_from_string("128.0.0.0", 0);
		}
		else
		{
			net = host_create_from_string("8000::", 0);
		}
		success = success && add_route(builder, net, 1);
		net->destroy(net);
		return success;
	}
	return builder->add_route(builder, net, prefix);
}

/**
 * Generate and set routes from installed IPsec policies
 */
static bool add_routes(vpnservice_builder_t *builder, child_sa_t *child_sa)
{
	traffic_selector_t *src_ts, *dst_ts;
	enumerator_t *enumerator;
	bool success = TRUE;

	enumerator = child_sa->create_policy_enumerator(child_sa);
	while (success && enumerator->enumerate(enumerator, &src_ts, &dst_ts))
	{
		host_t *net;
		uint8_t prefix;

		dst_ts->to_subnet(dst_ts, &net, &prefix);
		success = add_route(builder, net, prefix);
		net->destroy(net);
	}
	enumerator->destroy(enumerator);
	return success;
}

/**
 * Setup a new TUN device for the supplied SAs, also queues a job that
 * reads packets from this device.
 * Additional information such as DNS servers are gathered in appropriate
 * listeners asynchronously.  To be sure every required bit of information is
 * available this should be called after the CHILD_SA has been established.
 */
static bool setup_tun_device(private_android_service_t *this,
							 ike_sa_t *ike_sa, child_sa_t *child_sa)
{
	vpnservice_builder_t *builder;
	enumerator_t *enumerator;
	bool vip_found = FALSE, already_registered = FALSE;
	host_t *vip;
	int tunfd;

	DBG1(DBG_DMN, "setting up TUN device for CHILD_SA %s{%u}",
		 child_sa->get_name(child_sa), child_sa->get_unique_id(child_sa));

	builder = charonservice->get_vpnservice_builder(charonservice);

	enumerator = ike_sa->create_virtual_ip_enumerator(ike_sa, TRUE);
	while (enumerator->enumerate(enumerator, &vip))
	{
		if (!vip->is_anyaddr(vip))
		{
			if (!builder->add_address(builder, vip))
			{
				break;
			}
			vip_found = TRUE;
		}
	}
	enumerator->destroy(enumerator);

	if (!vip_found)
	{
		DBG1(DBG_DMN, "setting up TUN device failed, no virtual IP found");
		return FALSE;
	}
	if (!add_routes(builder, child_sa) ||
		!builder->set_mtu(builder, this->mtu))
	{
		return FALSE;
	}

	tunfd = builder->establish(builder);
	if (tunfd == -1)
	{
		return FALSE;
	}

	this->lock->write_lock(this->lock);
	if (this->tunfd > 0)
	{	/* close previously opened TUN device */
		close(this->tunfd);
		already_registered = true;
	}
	this->tunfd = tunfd;
	this->lock->unlock(this->lock);

	DBG1(DBG_DMN, "successfully created TUN device");

	if (!already_registered)
	{
		charon->receiver->add_esp_cb(charon->receiver,
								(receiver_esp_cb_t)receiver_esp_cb, NULL);
		ipsec->processor->register_inbound(ipsec->processor,
									  (ipsec_inbound_cb_t)deliver_plain, this);
		ipsec->processor->register_outbound(ipsec->processor,
									   (ipsec_outbound_cb_t)send_esp, NULL);
		this->dns_proxy->register_cb(this->dns_proxy,
								(dns_proxy_response_cb_t)deliver_plain, this);

		lib->processor->queue_job(lib->processor,
			(job_t*)callback_job_create((callback_job_cb_t)handle_plain, this,
									NULL, (callback_job_cancel_t)return_false));
	}
	return TRUE;
}

/**
 * Setup a new TUN device based on the existing one, but without DNS server.
 */
static bool setup_tun_device_without_dns(private_android_service_t *this)
{
	vpnservice_builder_t *builder;
	int tunfd;

	DBG1(DBG_DMN, "setting up TUN device without DNS");

	builder = charonservice->get_vpnservice_builder(charonservice);

	tunfd = builder->establish_no_dns(builder);
	if (tunfd == -1)
	{
		return FALSE;
	}

	this->lock->write_lock(this->lock);
	if (this->tunfd > 0)
	{	/* close previously opened TUN device, this should always be the case */
		close(this->tunfd);
	}
	this->tunfd = tunfd;
	this->lock->unlock(this->lock);

	DBG1(DBG_DMN, "successfully created TUN device without DNS");
	return TRUE;
}

/**
 * Close the current tun device
 */
static void close_tun_device(private_android_service_t *this)
{
	int tunfd;

	this->lock->write_lock(this->lock);
	if (this->tunfd < 0)
	{	/* already closed (or never created) */
		this->lock->unlock(this->lock);
		return;
	}
	tunfd = this->tunfd;
	this->tunfd = -1;
	this->lock->unlock(this->lock);

	this->dns_proxy->unregister_cb(this->dns_proxy,
								(dns_proxy_response_cb_t)deliver_plain);
	ipsec->processor->unregister_outbound(ipsec->processor,
										 (ipsec_outbound_cb_t)send_esp);
	ipsec->processor->unregister_inbound(ipsec->processor,
										(ipsec_inbound_cb_t)deliver_plain);
	charon->receiver->del_esp_cb(charon->receiver,
								(receiver_esp_cb_t)receiver_esp_cb);
	close(tunfd);
}

/**
 * Terminate the IKE_SA with the given unique ID
 */
CALLBACK(terminate, job_requeue_t,
	uint32_t *id)
{
	charon->controller->terminate_ike(charon->controller, *id,
									  controller_cb_empty, NULL, 0);
	return JOB_REQUEUE_NONE;
}

/**
 * Reestablish the IKE_SA with the given unique ID
 */
CALLBACK(reestablish, job_requeue_t,
	uint32_t *id)
{
	ike_sa_t *ike_sa;

	ike_sa = charon->ike_sa_manager->checkout_by_id(charon->ike_sa_manager, *id);
	if (ike_sa)
	{
		if (ike_sa->reauth(ike_sa) == DESTROY_ME)
		{
			charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager,
														ike_sa);
		}
		else
		{
			charon->ike_sa_manager->checkin(charon->ike_sa_manager, ike_sa);
		}
	}
	return JOB_REQUEUE_NONE;
}

METHOD(listener_t, ike_updown, bool,
	private_android_service_t *this, ike_sa_t *ike_sa, bool up)
{
	/* this callback is only registered during initiation, so if the IKE_SA
	 * goes down we assume some kind of authentication error, more specific
	 * errors are caught in the alert() handler */
	if (this->ike_sa == ike_sa && !up)
	{
		charonservice->update_status(charonservice,
									 CHARONSERVICE_AUTH_ERROR);
		return FALSE;
	}
	return TRUE;
}

METHOD(listener_t, ike_rekey, bool,
	private_android_service_t *this, ike_sa_t *old, ike_sa_t *new)
{
	if (this->ike_sa == old)
	{
		this->ike_sa = new;
	}
	return TRUE;
}

METHOD(listener_t, ike_reestablish_post_redirect, bool,
	private_android_service_t *this, ike_sa_t *old, ike_sa_t *new,
	bool initiated)
{
	if (this->ike_sa == old && initiated)
	{	/* if we get redirected during IKE_AUTH we just migrate to the new SA,
		 * we don't have a TUN device yet, so reinstalling it without DNS would
		 * fail (and using the DNS proxy is not required anyway) */
		this->ike_sa = new;
	}
	return TRUE;
}

METHOD(listener_t, ike_reestablish_pre, bool,
	private_android_service_t *this, ike_sa_t *old, ike_sa_t *new)
{
	if (this->ike_sa == old)
	{
		/* enable DNS proxy so hosts are properly resolved while the TUN device
		 * is still active */
		this->lock->write_lock(this->lock);
		this->use_dns_proxy = TRUE;
		this->lock->unlock(this->lock);
		/* if DNS servers are installed that are only reachable through the VPN
		 * the DNS proxy doesn't help, so uninstall DNS servers */
		if (!setup_tun_device_without_dns(this))
		{
			DBG1(DBG_DMN, "failed to setup TUN device without DNS");
			charonservice->update_status(charonservice,
										 CHARONSERVICE_GENERIC_ERROR);
		}
	}
	return TRUE;
}

METHOD(listener_t, ike_reestablish_post, bool,
	private_android_service_t *this, ike_sa_t *old, ike_sa_t *new,
	bool initiated)
{
	if (this->ike_sa == old && initiated)
	{
		this->ike_sa = new;
		/* re-register hook to detect initiation failures */
		this->public.listener.ike_updown = _ike_updown;
		/* if the IKE_SA got deleted by the responder we get the child_down()
		 * event on the old IKE_SA after this hook has been called, so they
		 * get ignored and thus we trigger the event here */
		charonservice->update_status(charonservice,
									 CHARONSERVICE_CHILD_STATE_DOWN);
	}
	return TRUE;
}

METHOD(listener_t, child_updown, bool,
	private_android_service_t *this, ike_sa_t *ike_sa, child_sa_t *child_sa,
	bool up)
{
	if (this->ike_sa == ike_sa)
	{
		if (up)
		{
			/* disable the hooks registered to catch initiation failures */
			this->public.listener.ike_updown = NULL;
			/* enable hooks to handle reauthentications */
			this->public.listener.ike_reestablish_pre = _ike_reestablish_pre;
			this->public.listener.ike_reestablish_post = _ike_reestablish_post;
			/* CHILD_SA is up so we can disable the DNS proxy we enabled to
			 * reestablish the SA */
			this->lock->write_lock(this->lock);
			this->use_dns_proxy = FALSE;
			this->lock->unlock(this->lock);
			if (!setup_tun_device(this, ike_sa, child_sa))
			{
				DBG1(DBG_DMN, "failed to setup TUN device");
				charonservice->update_status(charonservice,
											 CHARONSERVICE_GENERIC_ERROR);
				return FALSE;

			}
			charonservice->update_status(charonservice,
										 CHARONSERVICE_CHILD_STATE_UP);
		}
		else
		{
			charonservice->update_status(charonservice,
										 CHARONSERVICE_CHILD_STATE_DOWN);
		}
	}
	return TRUE;
}

METHOD(listener_t, alert, bool,
	private_android_service_t *this, ike_sa_t *ike_sa, alert_t alert,
	va_list args)
{
	bool stay_registered = TRUE;

	if (this->ike_sa == ike_sa)
	{
		switch (alert)
		{
			case ALERT_PEER_ADDR_FAILED:
				charonservice->update_status(charonservice,
											 CHARONSERVICE_LOOKUP_ERROR);
				return FALSE;

			case ALERT_PEER_AUTH_FAILED:
				charonservice->update_status(charonservice,
											 CHARONSERVICE_PEER_AUTH_ERROR);
				return FALSE;

			case ALERT_KEEP_ON_CHILD_SA_FAILURE:
			{
				uint32_t *id = malloc_thing(uint32_t);

				/* because close_ike_on_child_failure is set this is only
				 * triggered when CHILD_SA rekeying failed. reestablish it in
				 * the hope that the initial setup works again. */
				*id = ike_sa->get_unique_id(ike_sa);
				lib->processor->queue_job(lib->processor,
					(job_t*)callback_job_create_with_prio(
						(callback_job_cb_t)reestablish, id, free,
						(callback_job_cancel_t)return_false, JOB_PRIO_HIGH));
				break;
			}
			case ALERT_PEER_INIT_UNREACHABLE:
				this->lock->read_lock(this->lock);
				if (this->tunfd < 0)
				{
					uint32_t *id = malloc_thing(uint32_t);

					/* always fail if we are not able to initiate the IKE_SA
					 * initially */
					charonservice->update_status(charonservice,
											CHARONSERVICE_UNREACHABLE_ERROR);
					/* terminate the IKE_SA so no further keying tries are
					 * attempted */
					*id = ike_sa->get_unique_id(ike_sa);
					lib->processor->queue_job(lib->processor,
						(job_t*)callback_job_create_with_prio(
							(callback_job_cb_t)terminate, id, free,
							(callback_job_cancel_t)return_false, JOB_PRIO_HIGH));
					stay_registered = FALSE;
				}
				else
				{
					peer_cfg_t *peer_cfg;
					uint32_t tries, try;

					/* when reestablishing and if keyingtries is not %forever
					 * the IKE_SA is destroyed after the set number of tries,
					 * so notify the GUI */
					peer_cfg = ike_sa->get_peer_cfg(ike_sa);
					tries = peer_cfg->get_keyingtries(peer_cfg);
					try = va_arg(args, uint32_t);
					if (tries != 0 && try == tries-1)
					{
						charonservice->update_status(charonservice,
											CHARONSERVICE_UNREACHABLE_ERROR);
						stay_registered = FALSE;
					}
				}
				this->lock->unlock(this->lock);
				break;
			default:
				break;
		}
	}
	return stay_registered;
}

static void add_auth_cfg_pw(private_android_service_t *this,
							peer_cfg_t *peer_cfg, bool byod)
{
	identification_t *user, *id = NULL;
	auth_cfg_t *auth;
	char *username, *password, *local_id;

	auth = auth_cfg_create();
	auth->add(auth, AUTH_RULE_AUTH_CLASS, AUTH_CLASS_EAP);
	if (byod)
	{	/* use EAP-TTLS if BYOD is enabled */
		auth->add(auth, AUTH_RULE_EAP_TYPE, EAP_TTLS);
	}

	username = this->settings->get_str(this->settings, "connection.username",
									   NULL);
	password = this->settings->get_str(this->settings, "connection.password",
									   NULL);
	local_id = this->settings->get_str(this->settings, "connection.local_id",
									   NULL);
	user = identification_create_from_string(username);
	auth->add(auth, AUTH_RULE_EAP_IDENTITY, user);
	if (local_id)
	{
		id = identification_create_from_string(local_id);
	}
	if (!id)
	{
		id = user->clone(user);
	}
	auth->add(auth, AUTH_RULE_IDENTITY, id);

	this->creds->add_username_password(this->creds, username, password);
	peer_cfg->add_auth_cfg(peer_cfg, auth, TRUE);
}

static bool add_auth_cfg_cert(private_android_service_t *this,
							  peer_cfg_t *peer_cfg)
{
	certificate_t *cert;
	identification_t *id = NULL;
	auth_cfg_t *auth;
	char *type, *local_id;

	cert = this->creds->load_user_certificate(this->creds);
	if (!cert)
	{
		return FALSE;
	}

	type = this->settings->get_str(this->settings, "connection.type", NULL);
	auth = auth_cfg_create();
	if (strpfx("ikev2-eap-tls", type))
	{
		auth->add(auth, AUTH_RULE_AUTH_CLASS, AUTH_CLASS_EAP);
		auth->add(auth, AUTH_RULE_EAP_TYPE, EAP_TLS);
		auth->add(auth, AUTH_RULE_AAA_IDENTITY,
				  identification_create_from_string("%any"));
	}
	else
	{
		auth->add(auth, AUTH_RULE_AUTH_CLASS, AUTH_CLASS_PUBKEY);
	}
	auth->add(auth, AUTH_RULE_SUBJECT_CERT, cert);

	local_id = this->settings->get_str(this->settings, "connection.local_id",
									   NULL);
	if (local_id)
	{
		id = identification_create_from_string(local_id);
	}
	if (!id)
	{
		id = cert->get_subject(cert);
		id = id->clone(id);
	}
	auth->add(auth, AUTH_RULE_IDENTITY, id);
	peer_cfg->add_auth_cfg(peer_cfg, auth, TRUE);
	return TRUE;
}

static proposal_t *parse_proposal(private_android_service_t *this,
								  protocol_id_t proto, char *opt)
{
	proposal_t *proposal = NULL;
	char *prop;

	prop = this->settings->get_str(this->settings, opt, NULL);
	if (!prop || !strlen(prop))
	{
		return NULL;
	}

	proposal = proposal_create_from_string(proto, prop);
	if (!proposal)
	{
		DBG1(DBG_CFG, "invalid %N proposal '%s', falling back to defaults",
			 protocol_id_names, proto, prop);
	}
	return proposal;
}

static job_requeue_t initiate(private_android_service_t *this)
{
	identification_t *gateway = NULL;
	ike_cfg_t *ike_cfg;
	peer_cfg_t *peer_cfg;
	child_cfg_t *child_cfg;
	traffic_selector_t *ts;
	proposal_t *proposal;
	ike_sa_t *ike_sa;
	auth_cfg_t *auth;
	peer_cfg_create_t peer = {
		.cert_policy = CERT_ALWAYS_SEND,
		.unique = UNIQUE_REPLACE,
		.rekey_time = 36000, /* 10h */
		.jitter_time = 600, /* 10min */
		.over_time = 600, /* 10min */
	};
	child_cfg_create_t child = {
		.lifetime = {
			.time = {
				.life = 3600, /* 1h */
				.rekey = 3000, /* 50min */
				.jitter = 300 /* 5min */
			},
		},
		.mode = MODE_TUNNEL,
		.dpd_action = ACTION_RESTART,
		.close_action = ACTION_RESTART,
	};
	char *type, *server, *remote_id;
	int port;
	bool certreq;

	server = this->settings->get_str(this->settings, "connection.server", NULL);
	port = this->settings->get_int(this->settings, "connection.port",
								   IKEV2_UDP_PORT);
	certreq = this->settings->get_bool(this->settings, "connection.certreq",
									   TRUE);
	ike_cfg = ike_cfg_create(IKEV2, certreq, TRUE, "0.0.0.0",
							 charon->socket->get_port(charon->socket, FALSE),
							 server, port, FRAGMENTATION_YES, 0);
	proposal = parse_proposal(this, PROTO_IKE, "connection.ike_proposal");
	if (proposal)
	{
		ike_cfg->add_proposal(ike_cfg, proposal);
	}
	else
	{
		ike_cfg->add_proposal(ike_cfg, proposal_create_default(PROTO_IKE));
		ike_cfg->add_proposal(ike_cfg, proposal_create_default_aead(PROTO_IKE));
	}

	peer_cfg = peer_cfg_create("android", ike_cfg, &peer);
	peer_cfg->add_virtual_ip(peer_cfg, host_create_any(AF_INET));
	peer_cfg->add_virtual_ip(peer_cfg, host_create_any(AF_INET6));

	type = this->settings->get_str(this->settings, "connection.type", NULL);
	/* local auth config */
	if (streq("ikev2-cert", type) ||
		streq("ikev2-cert-eap", type) ||
		streq("ikev2-eap-tls", type))
	{
		if (!add_auth_cfg_cert(this, peer_cfg))
		{
			peer_cfg->destroy(peer_cfg);
			charonservice->update_status(charonservice,
										 CHARONSERVICE_GENERIC_ERROR);
			return JOB_REQUEUE_NONE;
		}
	}
	if (streq("ikev2-eap", type) ||
		streq("ikev2-cert-eap", type) ||
		streq("ikev2-byod-eap", type))
	{
		add_auth_cfg_pw(this, peer_cfg, strpfx(type, "ikev2-byod"));
	}

	/* remote auth config */
	auth = auth_cfg_create();
	remote_id = this->settings->get_str(this->settings, "connection.remote_id",
										NULL);
	if (remote_id)
	{
		gateway = identification_create_from_string(remote_id);
	}
	if (!gateway || gateway->get_type(gateway) == ID_ANY)
	{
		DESTROY_IF(gateway);
		gateway = identification_create_from_string(server);
		/* only use this if remote ID was not configured explicitly */
		auth->add(auth, AUTH_RULE_IDENTITY_LOOSE, TRUE);
	}
	auth->add(auth, AUTH_RULE_IDENTITY, gateway);
	auth->add(auth, AUTH_RULE_AUTH_CLASS, AUTH_CLASS_PUBKEY);
	peer_cfg->add_auth_cfg(peer_cfg, auth, FALSE);

	child_cfg = child_cfg_create("android", &child);
	proposal = parse_proposal(this, PROTO_ESP, "connection.esp_proposal");
	if (proposal)
	{
		child_cfg->add_proposal(child_cfg, proposal);
	}
	else
	{	/* create ESP proposals with and without DH groups, let responder decide
		 * if PFS is used */
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128gcm16-aes256gcm16-chacha20poly1305-"
								"curve25519-ecp256-modp3072"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128-sha256-curve25519-ecp256-modp3072"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes256-sha384-ecp521-modp8192"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128-aes192-aes256-sha1-sha256-sha384-sha512-"
								"curve25519-ecp256-ecp384-ecp521-"
								"modp2048-modp3072-modp4096"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128gcm16-aes256gcm16-chacha20poly1305"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128-sha256"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes256-sha384"));
		child_cfg->add_proposal(child_cfg, proposal_create_from_string(PROTO_ESP,
								"aes128-aes192-aes256-sha1-sha256-sha384-sha512"));
	}
	ts = traffic_selector_create_from_cidr("0.0.0.0/0", 0, 0, 65535);
	child_cfg->add_traffic_selector(child_cfg, TRUE, ts);
	ts = traffic_selector_create_from_cidr("0.0.0.0/0", 0, 0, 65535);
	child_cfg->add_traffic_selector(child_cfg, FALSE, ts);
	ts = traffic_selector_create_from_cidr("::/0", 0, 0, 65535);
	child_cfg->add_traffic_selector(child_cfg, TRUE, ts);
	ts = traffic_selector_create_from_cidr("::/0", 0, 0, 65535);
	child_cfg->add_traffic_selector(child_cfg, FALSE, ts);
	peer_cfg->add_child_cfg(peer_cfg, child_cfg);

	/* get us an IKE_SA */
	ike_sa = charon->ike_sa_manager->checkout_by_config(charon->ike_sa_manager,
														peer_cfg);
	if (!ike_sa)
	{
		peer_cfg->destroy(peer_cfg);
		charonservice->update_status(charonservice,
									 CHARONSERVICE_GENERIC_ERROR);
		return JOB_REQUEUE_NONE;
	}
	if (!ike_sa->get_peer_cfg(ike_sa))
	{
		ike_sa->set_peer_cfg(ike_sa, peer_cfg);
	}
	peer_cfg->destroy(peer_cfg);

	/* store the IKE_SA so we can track its progress */
	this->ike_sa = ike_sa;

	/* get an additional reference because initiate consumes one */
	child_cfg->get_ref(child_cfg);
	if (ike_sa->initiate(ike_sa, child_cfg, 0, NULL, NULL) != SUCCESS)
	{
		DBG1(DBG_CFG, "failed to initiate tunnel");
		charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager,
			ike_sa);
		return JOB_REQUEUE_NONE;
	}
	charon->ike_sa_manager->checkin(charon->ike_sa_manager, ike_sa);
	return JOB_REQUEUE_NONE;
}

METHOD(android_service_t, destroy, void,
	private_android_service_t *this)
{
	charon->bus->remove_listener(charon->bus, &this->public.listener);
	/* make sure the tun device is actually closed */
	close_tun_device(this);
	this->dns_proxy->destroy(this->dns_proxy);
	this->lock->destroy(this->lock);
	this->settings->destroy(this->settings);
	free(this);
}

/**
 * See header
 */
android_service_t *android_service_create(android_creds_t *creds,
										  settings_t *settings)
{
	private_android_service_t *this;

	INIT(this,
		.public = {
			.listener = {
				.ike_rekey = _ike_rekey,
				.ike_reestablish_post = _ike_reestablish_post_redirect,
				.ike_updown = _ike_updown,
				.child_updown = _child_updown,
				.alert = _alert,
			},
			.destroy = _destroy,
		},
		.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
		.dns_proxy = android_dns_proxy_create(),
		.settings = settings,
		.creds = creds,
		.tunfd = -1,
		.mtu = settings->get_int(settings, "global.mtu", ANDROID_DEFAULT_MTU),
	);
	/* only allow queries for the VPN gateway */
	this->dns_proxy->add_hostname(this->dns_proxy,
			this->settings->get_str(this->settings, "connection.server", NULL));

	charon->bus->add_listener(charon->bus, &this->public.listener);

	lib->processor->queue_job(lib->processor,
		(job_t*)callback_job_create((callback_job_cb_t)initiate, this,
									NULL, NULL));
	return &this->public;
}