bind/lib/omapi/listener.c

/*
 * Copyright (C) 1996, 1997, 1998, 1999  Internet Software Consortium.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Subroutines that support the generic listener object.
 */
#include <stddef.h>		/* NULL */
#include <string.h>		/* memset */
#include <unistd.h>		/* close */

#include <isc/assertions.h>
#include <isc/bufferlist.h>
#include <isc/mem.h>

#include <omapi/private.h>

typedef struct omapi_listener_object {
	OMAPI_OBJECT_PREAMBLE;
	isc_task_t *task;
	isc_socket_t *socket;	/* Connection socket. */
	isc_sockaddr_t address;
} omapi_listener_object_t;

/*
 * Reader callback for a listener object.   Accept an incoming connection.
 */
static void
omapi_listener_accept(isc_task_t *task, isc_event_t *event) {
	isc_result_t result;
	isc_buffer_t *ibuffer, *obuffer;
	isc_task_t *connection_task = NULL;
	isc_socket_newconnev_t *incoming;
	omapi_connection_object_t *connection = NULL;
	omapi_object_t *listener;

	/*
	 * XXXDCL What are the meaningful things the listen/accept function
	 * can do if it fails to process an incoming connection because one
	 * of the functions it calls fails?
	 */

	/*
	 * Set up another listen task for the socket.
	 */
	isc_socket_accept(event->sender, task, omapi_listener_accept,
			  event->arg);

	/*
	 * Check for the validity of new connection event.
	 */
	incoming = (isc_socket_newconnev_t *)event;
	if (incoming->result != ISC_R_SUCCESS)
		/*
		 * The result is probably ISC_R_UNEXPECTED; what can really be
		 * done about this other than just flunking out of here?
		 */
		return;

	/*
	 * The new connection is good to go.  Allocate the buffers for it and
	 * prepare its own task.
	 */
	if (isc_task_create(omapi_taskmgr, NULL, 0, &connection_task) !=
	    ISC_R_SUCCESS)
		return;

	ibuffer = NULL;
	result = isc_buffer_allocate(omapi_mctx, &ibuffer, OMAPI_BUFFER_SIZE,
				     ISC_BUFFERTYPE_BINARY);
	if (result != ISC_R_SUCCESS)
		return;

	obuffer = NULL;
	result = isc_buffer_allocate(omapi_mctx, &obuffer, OMAPI_BUFFER_SIZE,
				     ISC_BUFFERTYPE_BINARY);
	if (result != ISC_R_SUCCESS)
		return;

	/*
	 * Create a new connection object.
	 */
	result = omapi_object_new((omapi_object_t **)&connection,
				  omapi_type_connection, sizeof(*connection));
	if (result != ISC_R_SUCCESS) {
		/* XXXDCL cleanup */
		isc_buffer_free(&obuffer);
		isc_buffer_free(&ibuffer);
		return;
	}

	connection->task = connection_task;
	connection->state = omapi_connection_connected;
	connection->socket = incoming->newsocket;

	ISC_LIST_INIT(connection->input_buffers);
	ISC_LIST_APPEND(connection->input_buffers, ibuffer, link);
	ISC_LIST_INIT(connection->output_buffers);
	ISC_LIST_APPEND(connection->output_buffers, obuffer, link);

	/*
	 * Point the connection's listener member at the listener object.
	 * XXXDCL but why is this needed?
	 */
	listener = event->arg;
	OBJECT_REF(&connection->listener, listener, "omapi_listener_accept");

	/*
	 * Notify the listener object that a connection was made.
	 */
	result = omapi_signal(listener, "connect", connection);
	if (result != ISC_R_SUCCESS)
		/*XXXDCL then what?!*/
		;

	/*
	 * Lose our reference to the connection, so it'll be gc'd when it's
	 * reaped.
	 * XXXDCL ... um, hmm?  this object only has one reference, so it
	 * is going to be reaped right here!  unless omapi_signal added
	 * a reference ...
	 */
	OBJECT_DEREF(&connection, "omapi_listener_accept");

	return;
}

isc_result_t
omapi_listener_listen(omapi_object_t *caller, int port, int max) {
	isc_result_t result;
	isc_task_t *task;
	omapi_listener_object_t *listener;
	struct in_addr inaddr;

	task = NULL;
	result = isc_task_create(omapi_taskmgr, NULL, 0, &task);
	if (result != ISC_R_SUCCESS)
		return (result);

#if 0 /*XXXDCL*/
	result = isc_task_onshutdown(task, omapi_listener_shutdown, NULL);
	if (result != ISC_R_SUCCESS)
		return (result);
#endif

	/*
	 * Get the handle.
	 */
	listener = isc_mem_get(omapi_mctx, sizeof(*listener));
	if (listener == NULL)
		return (ISC_R_NOMEMORY);
	memset(listener, 0, sizeof(*listener));
	listener->object_size = sizeof(*listener);
	listener->refcnt = 1;
	listener->task = task;
	listener->type = omapi_type_listener;

	/*
	 * Tie the listener object to the calling object.
	 */
	OBJECT_REF(&caller->outer, listener, "omapi_protocol_listen");
	OBJECT_REF(&listener->inner, caller, "omapi_protocol_listen");

	/*
	 * Create a socket on which to listen.
	 */
	listener->socket = NULL;
	result = isc_socket_create(omapi_socketmgr, PF_INET,
				   isc_sockettype_tcp, &listener->socket);
	if (result != ISC_R_SUCCESS) {
		/* XXXDCL this call and later will not free the listener
		 * because it has two refcnts, one for existing plus one
		 * for the tie to h->outer.  This does not seem right to me.
		 */
		OBJECT_DEREF(&listener, "omapi_listen");
		return (result);
	}
	
	/*
	 * Set up the address on which we will listen.
	 */
	inaddr.s_addr = INADDR_ANY;
	isc_sockaddr_fromin(&listener->address, &inaddr, port);

	/*
	 * Try to bind to the wildcard address using the port number
	 * we were given.
	 */
	result = isc_socket_bind(listener->socket, &listener->address);
	if (result != ISC_R_SUCCESS) {
		OBJECT_DEREF(&listener, "omapi_listen");
		return (result);
	}

	/*
	 * Now tell the kernel to listen for connections.
	 */
	result = isc_socket_listen(listener->socket, max);
	if (result != ISC_R_SUCCESS) {
		OBJECT_DEREF(&listener, "omapi_listen");
		return (result);
	}

	/*
	 * Queue up the first accept event.  The listener object
	 * will be passed to omapi_listener_accept() when it is called.
	 */
	result = isc_socket_accept(listener->socket, task,
				   omapi_listener_accept, listener);
	if (result != ISC_R_SUCCESS)
		OBJECT_DEREF(&listener, "omapi_listen");

	return (result);
}

isc_result_t
omapi_listener_setvalue(omapi_object_t *listener, omapi_object_t *id,
			omapi_data_string_t *name, omapi_typed_data_t *value)
{
	/*
	 * Nothing meaningful can be set in a listener object; just
	 * continue the call through the object chain.
	 */
	REQUIRE(listener != NULL && listener->type == omapi_type_listener);

	PASS_SETVALUE(listener);
}

isc_result_t
omapi_listener_getvalue(omapi_object_t *listener, omapi_object_t *id,
			omapi_data_string_t *name, omapi_value_t **value)
{
	/*
	 * Nothing meaningful can be fetched from a listener object; just
	 * continue the call through the object chain.
	 */
	REQUIRE(listener != NULL && listener->type == omapi_type_listener);
	
	PASS_GETVALUE(listener);
}

void
omapi_listener_destroy(omapi_object_t *object, const char *name) {
	omapi_listener_object_t *listener;

	REQUIRE(object != NULL && object->type == omapi_type_listener);

	(void)name;		/* Unused. */

	listener = (omapi_listener_object_t *)object;

	if (listener->socket != NULL) {
#if 0 /*XXXDCL*/
		isc_socket_cancel(listener->socket, NULL, ISC_SOCKCANCEL_ALL);
		isc_socket_shutdown(listener->socket, ISC_SOCKSHUT_ALL);
#else
		isc_task_shutdown(listener->task);
#endif
		listener->socket = NULL;
	}
}

isc_result_t
omapi_listener_signalhandler(omapi_object_t *listener, const char *name,
			      va_list ap)
{
	REQUIRE(listener != NULL && listener->type == omapi_type_listener);
	
	/*
	 * This function is reached when omapi_listener_accept does
	 * an omapi_signal of "connect" on the listener object.  Nothing
	 * need be done here, but the object that originally requested
	 * the listen needs to signalled that a connection was made.
	 *
	 * In the normal instance, the pass-through is to an object of type
 	 * omapi_type_protocol_listener, so the signal_handler that
	 * is getting called is omapi_protocol_listener_signal.
	 */
	PASS_SIGNAL(listener);
}

/*
 * Write all the published values associated with the object through the
 * specified connection.
 */
isc_result_t
omapi_listener_stuffvalues(omapi_object_t *connection, omapi_object_t *id,
			   omapi_object_t *listener)
{
	REQUIRE(listener != NULL && listener->type == omapi_type_listener);

	PASS_STUFFVALUES(listener);
}