peer.c

Linux下的多协议即时通讯程序源代码

	/* Cancel this timer.  It'll be added again, if needed. */
	return FALSE;
}

/**
 * Try to establish the given PeerConnection using a defined
 * sequence of steps.
 */
void
peer_connection_trynext(PeerConnection *conn)
{
	PurpleAccount *account;

	account = purple_connection_get_account(conn->od->gc);

	/*
	 * Close any remnants of a previous failed connection attempt.
	 */
	peer_connection_close(conn);

	/*
	 * 1. Attempt to connect to the remote user using their verifiedip and clientip.
	 *    We try these at the same time and use whichever succeeds first, so we don't
	 *    have to wait for a timeout.
	 */
	if (!(conn->flags & PEER_CONNECTION_FLAG_TRIED_DIRECT) &&
		(conn->verifiedip != NULL) && (conn->port != 0) && (!conn->use_proxy))
	{
		conn->flags |= PEER_CONNECTION_FLAG_TRIED_DIRECT;

		if (conn->type == OSCAR_CAPABILITY_DIRECTIM)
		{
			gchar *tmp;
			PurpleConversation *conv;
			tmp = g_strdup_printf(_("Attempting to connect to %s:%hu."),
					conn->verifiedip, conn->port);
			conv = purple_conversation_new(PURPLE_CONV_TYPE_IM, account, conn->sn);
			purple_conversation_write(conv, NULL, tmp,
					PURPLE_MESSAGE_SYSTEM, time(NULL));
			g_free(tmp);
		}

		conn->verified_connect_data = purple_proxy_connect(NULL, account,
				conn->verifiedip, conn->port,
				peer_connection_verified_established_cb, conn);

		if ((conn->verifiedip == NULL) ||
			strcmp(conn->verifiedip, conn->clientip))
		{
			conn->client_connect_data = purple_proxy_connect(NULL, account,
					conn->clientip, conn->port,
					peer_connection_client_established_cb, conn);
		}

		if ((conn->verified_connect_data != NULL) ||
			(conn->client_connect_data != NULL))
		{
			/* Connecting... */
			conn->connect_timeout_timer = purple_timeout_add(5000,
					peer_connection_tooktoolong, conn);
			return;
		}
	}

	/*
	 * 2. Attempt to have the remote user connect to us (using both
	 *    our verifiedip and our clientip).
	 */
	if (!(conn->flags & PEER_CONNECTION_FLAG_TRIED_INCOMING) &&
		(!conn->use_proxy))
	{
		conn->flags |= PEER_CONNECTION_FLAG_TRIED_INCOMING;

		/*
		 * Remote user is connecting to us, so we'll need to verify
		 * that the user who connected is our friend.
		 */
		conn->flags |= PEER_CONNECTION_FLAG_IS_INCOMING;

		conn->listen_data = purple_network_listen_range(5190, 5290, SOCK_STREAM,
				peer_connection_establish_listener_cb, conn);
		if (conn->listen_data != NULL)
		{
			/* Opening listener socket... */
			return;
		}
	}

	/*
	 * 3. Attempt to have both users connect to an intermediate proxy
	 *    server.
	 */
	if (!(conn->flags & PEER_CONNECTION_FLAG_TRIED_PROXY))
	{
		conn->flags |= PEER_CONNECTION_FLAG_TRIED_PROXY;

		/*
		 * If we initiate the proxy connection, then the remote user
		 * could be anyone, so we need to verify that the user who
		 * connected is our friend.
		 */
		if (!conn->use_proxy)
			conn->flags |= PEER_CONNECTION_FLAG_IS_INCOMING;

		if (conn->type == OSCAR_CAPABILITY_DIRECTIM)
		{
			gchar *tmp;
			PurpleConversation *conv;
			tmp = g_strdup_printf(_("Attempting to connect via proxy server."));
			conv = purple_conversation_new(PURPLE_CONV_TYPE_IM, account, conn->sn);
			purple_conversation_write(conv, NULL, tmp,
					PURPLE_MESSAGE_SYSTEM, time(NULL));
			g_free(tmp);
		}

		conn->verified_connect_data = purple_proxy_connect(NULL, account,
				(conn->proxyip != NULL) ? conn->proxyip : PEER_PROXY_SERVER,
				PEER_PROXY_PORT,
				peer_proxy_connection_established_cb, conn);
		if (conn->verified_connect_data != NULL)
		{
			/* Connecting... */
			return;
		}
	}

	/* Give up! */
	peer_connection_destroy(conn, OSCAR_DISCONNECT_COULD_NOT_CONNECT, NULL);
}

/**
 * Initiate a peer connection with someone.
 */
void
peer_connection_propose(OscarData *od, OscarCapability type, const char *sn)
{
	PeerConnection *conn;

	if (type == OSCAR_CAPABILITY_DIRECTIM)
	{
		conn = peer_connection_find_by_type(od, sn, type);
		if (conn != NULL)
		{
			if (conn->ready)
			{
				PurpleAccount *account;
				PurpleConversation *conv;

				purple_debug_info("oscar", "Already have a direct IM "
						"session with %s.\n", sn);
				account = purple_connection_get_account(od->gc);
				conv = purple_find_conversation_with_account(PURPLE_CONV_TYPE_IM,
						sn, account);
				if (conv != NULL)
					purple_conversation_present(conv);
				return;
			}

			/* Cancel the old connection and try again */
			peer_connection_destroy(conn, OSCAR_DISCONNECT_RETRYING, NULL);
		}
	}

	conn = peer_connection_new(od, type, sn);
	conn->flags |= PEER_CONNECTION_FLAG_INITIATED_BY_ME;
	conn->flags |= PEER_CONNECTION_FLAG_APPROVED;
	aim_icbm_makecookie(conn->cookie);

	peer_connection_trynext(conn);
}

/**
 * Someone else wants to establish a peer connection with us,
 * and we said yes.
 */
static void
peer_connection_got_proposition_yes_cb(gpointer data, gint id)
{
	PeerConnection *conn;

	conn = data;

	conn->flags |= PEER_CONNECTION_FLAG_APPROVED;
	peer_connection_trynext(conn);
}

/**
 * Someone else wants to establish a peer connection with us,
 * and we said no.
 *
 * "Well, one time my friend asked me if I wanted to play the
 *  piccolo.  But I said no."
 */
static void
peer_connection_got_proposition_no_cb(gpointer data, gint id)
{
	PeerConnection *conn;

	conn = data;

	aim_im_denytransfer(conn->od, conn->sn, conn->cookie,
			AIM_TRANSFER_DENY_DECLINE);
	peer_connection_destroy(conn, OSCAR_DISCONNECT_LOCAL_CLOSED, NULL);
}

/**
 * Someone else wants to establish a peer connection with us.
 */
void
peer_connection_got_proposition(OscarData *od, const gchar *sn, const gchar *message, IcbmArgsCh2 *args)
{
	PurpleConnection *gc;
	PurpleAccount *account;
	PeerConnection *conn;
	gchar *buf;

	gc = od->gc;
	account = purple_connection_get_account(gc);

	/*
	 * If we have a connection with this same cookie then they are
	 * probably just telling us they weren't able to connect to us
	 * and we should try connecting to them, instead.  Or they want
	 * to go through a proxy.
	 */
	conn = peer_connection_find_by_cookie(od, sn, args->cookie);
	if ((conn != NULL) && (conn->type == args->type))
	{
		purple_debug_info("oscar", "Remote user wants to try a "
				"different connection method\n");
		g_free(conn->proxyip);
		g_free(conn->clientip);
		g_free(conn->verifiedip);
		if (args->use_proxy)
			conn->proxyip = g_strdup(args->proxyip);
		else
			conn->proxyip = NULL;
		conn->verifiedip = g_strdup(args->verifiedip);
		conn->clientip = g_strdup(args->clientip);
		conn->port = args->port;
		conn->use_proxy |= args->use_proxy;
		conn->lastrequestnumber++;
		peer_connection_trynext(conn);
		return;
	}

	/* If this is a direct IM, then close any existing session */
	if (args->type == OSCAR_CAPABILITY_DIRECTIM)
	{
		conn = peer_connection_find_by_type(od, sn, args->type);
		if (conn != NULL)
		{
			/* Close the old direct IM and start a new one */
			purple_debug_info("oscar", "Received new direct IM request "
				"from %s.  Destroying old connection.\n", sn);
			peer_connection_destroy(conn, OSCAR_DISCONNECT_REMOTE_CLOSED, NULL);
		}
	}

	/* Check for proper arguments */
	if (args->type == OSCAR_CAPABILITY_SENDFILE)
	{
		if ((args->info.sendfile.filename == NULL) ||
			(args->info.sendfile.totsize == 0) ||
			(args->info.sendfile.totfiles == 0))
		{
			purple_debug_warning("oscar",
					"%s tried to send you a file with incomplete "
					"information.\n", sn);
			return;
		}
	}

	conn = peer_connection_new(od, args->type, sn);
	memcpy(conn->cookie, args->cookie, 8);
	if (args->use_proxy)
		conn->proxyip = g_strdup(args->proxyip);
	conn->clientip = g_strdup(args->clientip);
	conn->verifiedip = g_strdup(args->verifiedip);
	conn->port = args->port;
	conn->use_proxy |= args->use_proxy;
	conn->lastrequestnumber++;

	if (args->type == OSCAR_CAPABILITY_DIRECTIM)
	{
		buf = g_strdup_printf(_("%s has just asked to directly connect to %s"),
				sn, purple_account_get_username(account));

		purple_request_action(conn, NULL, buf,
						_("This requires a direct connection between "
						  "the two computers and is necessary for IM "
						  "Images.  Because your IP address will be "
						  "revealed, this may be considered a privacy "
						  "risk."),
						PURPLE_DEFAULT_ACTION_NONE,
						account, sn, NULL,
						conn, 2,
						_("_Connect"), G_CALLBACK(peer_connection_got_proposition_yes_cb),
						_("Cancel"), G_CALLBACK(peer_connection_got_proposition_no_cb));
	}
	else if (args->type == OSCAR_CAPABILITY_SENDFILE)
	{
		gchar *filename;

		conn->xfer = purple_xfer_new(account, PURPLE_XFER_RECEIVE, sn);
		if (conn->xfer)
		{
			conn->xfer->data = conn;
			purple_xfer_ref(conn->xfer);
			purple_xfer_set_size(conn->xfer, args->info.sendfile.totsize);

			/* Set the file name */
			if (g_utf8_validate(args->info.sendfile.filename, -1, NULL))
				filename = g_strdup(args->info.sendfile.filename);
			else
				filename = purple_utf8_salvage(args->info.sendfile.filename);

			if (args->info.sendfile.subtype == AIM_OFT_SUBTYPE_SEND_DIR)
			{
				/*
				 * If they are sending us a directory then the last character
				 * of the file name will be an asterisk.  We don't want to
				 * save stuff to a directory named "*" so we remove the
				 * asterisk from the file name.
				 */
				char *tmp = strrchr(filename, '\\');
				if ((tmp != NULL) && (tmp[1] == '*'))
					tmp[0] = '\0';
			}
			purple_xfer_set_filename(conn->xfer, filename);
			g_free(filename);

			/*
			 * Set the message, unless this is the dummy message from an
			 * ICQ client or an empty message from an AIM client.
			 * TODO: Maybe we should strip HTML and then see if strlen>0?
			 */
			if ((message != NULL) &&
				(g_ascii_strncasecmp(message, "<ICQ_COOL_FT>", 13) != 0) &&
				(g_ascii_strcasecmp(message, "<HTML>") != 0))
			{
				purple_xfer_set_message(conn->xfer, message);
			}

			/* Setup our I/O op functions */
			purple_xfer_set_init_fnc(conn->xfer, peer_oft_recvcb_init);
			purple_xfer_set_end_fnc(conn->xfer, peer_oft_recvcb_end);
			purple_xfer_set_request_denied_fnc(conn->xfer, peer_oft_cb_generic_cancel);
			purple_xfer_set_cancel_recv_fnc(conn->xfer, peer_oft_cb_generic_cancel);
			purple_xfer_set_ack_fnc(conn->xfer, peer_oft_recvcb_ack_recv);

			/* Now perform the request */
			purple_xfer_request(conn->xfer);
		}
	}
}

/*******************************************************************/
/* End code for establishing a peer connection                     */
/*******************************************************************/