/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*

 * Copyright (C) 2003 Imendio HB

 * Copyright (C) 2003 Mikael Hallendal <micke@imendio.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this program; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#include <config.h>

#ifdef HAVE_GNUTLS

#include <gnutls/gnutls.h>

#endif

#include <string.h>

#include <unistd.h>

#include <sys/types.h>

#include <fcntl.h>

#include <errno.h>

#ifndef __WIN32__

  #include <netdb.h>

  #include <sys/socket.h>

  #include <netinet/in.h>

  #include <sys/time.h>

#else

  #include <winsock2.h>

#endif

#include "lm-debug.h"

#include "lm-error.h"

#include "lm-internals.h"

#include "lm-parser.h"

#include "lm-sha.h"

#include "lm-queue.h"

#include "lm-connection.h"

#define IN_BUFFER_SIZE 1024

typedef struct {

	LmHandlerPriority  priority;

	LmMessageHandler  *handler;

} HandlerData;

typedef struct {

	LmConnection *connection;

} LmIncomingSource;

struct _LmConnection {

	/* Parameters */

	gchar          *server;

	guint           port;

	char	        fingerprint[20];

#ifdef HAVE_GNUTLS

	gnutls_session  gnutls_session;

	gnutls_certificate_client_credentials gnutls_xcred;

#endif

	LmParser   *parser;

	gchar      *stream_id;

	GHashTable *id_handlers;

	GSList     *handlers[LM_MESSAGE_TYPE_UNKNOWN];

	/* Communication */

	GIOChannel *io_channel;

	guint       io_watch_in;

	guint       io_watch_err;

	guint       io_watch_hup;

	guint       fd;

	guint       open_id;

	LmCallback *open_cb;

	gboolean    cancel_open;

	LmCallback *close_cb;

	LmCallback *auth_cb;

	LmCallback *register_cb;

	LmCallback *disconnect_cb;

	LmSSLFunction  ssl_func;

	gpointer       ssl_func_data;

	gchar         *expected_fingerprint;

	LmQueue    *incoming_messages;

	GSource    *incoming_source;

	LmConnectionState state;

	gint        ref_count;

};

typedef enum {

	AUTH_TYPE_PLAIN  = 1,

	AUTH_TYPE_DIGEST = 2,

	AUTH_TYPE_0K     = 4

} AuthType;

static void     connection_free (LmConnection *connection);

static void     connection_handle_message    (LmConnection         *connection,

					      LmMessage            *message);

static void     connection_new_message_cb    (LmParser             *parser,

					      LmMessage            *message,

					      LmConnection         *connection);

static gboolean connection_do_open           (LmConnection         *connection,

					      GError              **error);

static void     connection_do_close           (LmConnection        *connection);

static gboolean connection_in_event          (GIOChannel   *source,

					      GIOCondition  condition,

					      LmConnection *connection);

static gboolean connection_error_event       (GIOChannel   *source,

					      GIOCondition  condition,

					      LmConnection *connection);

static gboolean connection_hup_event         (GIOChannel   *source,

					      GIOCondition  condition,

					      LmConnection *connection);

static gboolean connection_send              (LmConnection             *connection,

					      const gchar          *str,

					      gint                  len,

					      GError               **error);

static LmMessage *     connection_create_auth_req_msg (const gchar *username);

static LmMessage *     connection_create_auth_msg     (LmConnection *connection,

						       const gchar  *username,

						       const gchar  *password,

						       const gchar  *resource,

						       gint          auth_type);

static LmHandlerResult connection_auth_req_reply (LmMessageHandler *handler,

						  LmConnection     *connection,

						  LmMessage        *m,

						  gpointer          user_data);

static int connection_check_auth_type   (LmMessage           *auth_req_rpl);

static LmHandlerResult connection_auth_reply (LmMessageHandler    *handler,

					      LmConnection        *connection,

					      LmMessage           *m,

					      gpointer             user_data);

static void     connection_stream_received   (LmConnection             *connection, 

					      LmMessage                *m);

static gint     connection_handler_compare_func (HandlerData  *a,

						 HandlerData  *b);

static gboolean connection_incoming_prepare  (GSource         *source,

					      gint            *timeout);

static gboolean connection_incoming_check    (GSource         *source);

static gboolean connection_incoming_dispatch (GSource         *source,

					      GSourceFunc      callback,

					      gpointer           user_data);

static GSourceFuncs incoming_funcs = {

	connection_incoming_prepare,

	connection_incoming_check,

	connection_incoming_dispatch,

	NULL

};

static void

connection_free (LmConnection *connection)

{

	int i;

	g_free (connection->server);

	/* Unref handlers */

	for (i = 0; i < LM_MESSAGE_TYPE_UNKNOWN; ++i) {

		GSList *l;

		for (l = connection->handlers[i]; l; l = l->next) {

			HandlerData *hd = (HandlerData *) l->data;

			lm_message_handler_unref (hd->handler);

			g_free (hd);

		}

		g_slist_free (connection->handlers[i]);

	}

	g_hash_table_destroy (connection->id_handlers);

	if (lm_connection_is_open (connection)) {

		connection_do_close (connection);

	}

	g_free (connection);

}

static void

connection_handle_message (LmConnection *connection, LmMessage *m)

{

	LmMessageHandler *handler;

	GSList           *l;

	const gchar      *id;

	LmHandlerResult   result = LM_HANDLER_RESULT_ALLOW_MORE_HANDLERS;

	if (lm_message_get_type (m) == LM_MESSAGE_TYPE_STREAM) {

		connection_stream_received (connection, m);

		return;

	}

	id = lm_message_node_get_attribute (m->node, "id");

	if (id) {

		handler = g_hash_table_lookup (connection->id_handlers, id);

		if (handler) {

			result = _lm_message_handler_handle_message (handler, 

								     connection,

								     m);

			g_hash_table_remove (connection->id_handlers, id);

		}

	}

	if (result == LM_HANDLER_RESULT_REMOVE_MESSAGE) {

		return;

	}

	for (l = connection->handlers[lm_message_get_type (m)]; 

	     l && result == LM_HANDLER_RESULT_ALLOW_MORE_HANDLERS; 

	     l = l->next) {

		HandlerData *hd = (HandlerData *) l->data;

		result = _lm_message_handler_handle_message (hd->handler,

							     connection,

							     m);

	}

	return;

}

static void

connection_new_message_cb (LmParser     *parser,

			   LmMessage    *m,

			   LmConnection *connection)

{

	lm_message_ref (m);

	lm_verbose ("New message with type=\"%s\" from: %s\n",

		    _lm_message_type_to_string (lm_message_get_type (m)),

		    lm_message_node_get_attribute (m->node, "from"));

	lm_queue_push_tail (connection->incoming_messages, m);

}

#ifdef HAVE_GNUTLS

static gboolean

connection_verify_certificate (LmConnection *connection)

{

	int status;

	LmSSLFunction ssl_function = connection->ssl_func;

	/* This verification function uses the trusted CAs in the credentials

	 * structure. So you must have installed one or more CA certificates.

	 */

	status = gnutls_certificate_verify_peers (connection->gnutls_session);

	if (status == GNUTLS_E_NO_CERTIFICATE_FOUND)

		if (ssl_function (connection,

				   LM_SSL_STATUS_NO_CERT_FOUND,

				   connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

			return FALSE;

	if (status & GNUTLS_CERT_INVALID

	    || status & GNUTLS_CERT_NOT_TRUSTED

	    || status & GNUTLS_CERT_CORRUPTED

	    || status & GNUTLS_CERT_REVOKED)

		if (ssl_function (connection,

				   LM_SSL_STATUS_UNTRUSTED_CERT,

				   connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

			return FALSE;

	if (gnutls_certificate_expiration_time_peers (connection->gnutls_session) < time (0)) {

		if (ssl_function (connection,

				   LM_SSL_STATUS_CERT_EXPIRED,

				   connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

			return FALSE;

	}

	if (gnutls_certificate_activation_time_peers (connection->gnutls_session) > time (0)) {

		if (ssl_function (connection,

				  LM_SSL_STATUS_CERT_NOT_ACTIVATED,

				  connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

			return FALSE;

	}

	if (gnutls_certificate_type_get (connection->gnutls_session) == GNUTLS_CRT_X509) {

		const gnutls_datum* cert_list;

		int cert_list_size;

		int digest_size;

		cert_list = gnutls_certificate_get_peers (connection->gnutls_session, &cert_list_size);

		if (cert_list == NULL) {

			if (ssl_function (connection,

					   LM_SSL_STATUS_NO_CERT_FOUND,

					   connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

				return FALSE;

		}

		if (!gnutls_x509_check_certificates_hostname (&cert_list[0],

							      connection->server)) {

			if (ssl_function (connection,

					  LM_SSL_STATUS_CERT_HOSTNAME_MISMATCH,

					  connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

				return FALSE;

		}

		if (gnutls_x509_fingerprint (GNUTLS_DIG_MD5, &cert_list[0],

					     connection->fingerprint,

					     &digest_size) >= 0) {

			if (connection->expected_fingerprint &&

			    memcmp (connection->expected_fingerprint, connection->fingerprint,

				    digest_size) &&

			    ssl_function (connection,

					   LM_SSL_STATUS_CERT_FINGERPRINT_MISMATCH,

					   connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

				return FALSE;

		} else if (ssl_function (connection,

					  LM_SSL_STATUS_GENERIC_ERROR,

					  connection->ssl_func_data) != LM_SSL_RESPONSE_CONTINUE)

			return FALSE;

	}

	return TRUE;

}

#endif

static gboolean

{

	/* Need some way to report error/success */

	if (connection->cancel_open) {

		return FALSE;

	}

	/* FIXME: Handle error */

	if (!connection_begin_ssl (connection, NULL)) {

		connection->fd = -1;

		return FALSE;

	}

	g_io_channel_set_close_on_unref (connection->io_channel, TRUE);

	g_io_channel_set_encoding (connection->io_channel, NULL, NULL);

	g_io_channel_set_buffered (connection->io_channel, FALSE);

	g_io_channel_set_flags (connection->io_channel,

	connection->io_watch_in = g_io_add_watch (connection->io_channel,

						  G_IO_IN,

						  (GIOFunc) connection_in_event,

						  connection);