interfacemgr.h

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/*
 * Copyright (C) 2004, 2005, 2007, 2011, 2013, 2014  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/* $Id: interfacemgr.h,v 1.35 2011/07/28 23:47:58 tbox Exp $ */

#ifndef NAMED_INTERFACEMGR_H
#define NAMED_INTERFACEMGR_H 1

/*****
 ***** Module Info
 *****/

/*! \file
 * \brief
 * The interface manager monitors the operating system's list
 * of network interfaces, creating and destroying listeners
 * as needed.
 *
 * Reliability:
 *\li   No impact expected.
 *
 * Resources:
 *
 * Security:
 * \li  The server will only be able to bind to the DNS port on
 *      newly discovered interfaces if it is running as root.
 *
 * Standards:
 *\li   The API for scanning varies greatly among operating systems.
 *      This module attempts to hide the differences.
 */

/***
 *** Imports
 ***/

#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/socket.h>

#include <dns/result.h>

#include <named/listenlist.h>
#include <named/types.h>

/***
 *** Types
 ***/

#define IFACE_MAGIC             ISC_MAGIC('I',':','-',')')
#define NS_INTERFACE_VALID(t)   ISC_MAGIC_VALID(t, IFACE_MAGIC)

#define NS_INTERFACEFLAG_ANYADDR        0x01U   /*%< bound to "any" address */
#define MAX_UDP_DISPATCH 128            /*%< Maximum number of UDP dispatchers
                                                     to start per interface */
/*% The nameserver interface structure */
struct ns_interface {
        unsigned int            magic;          /*%< Magic number. */
        ns_interfacemgr_t *     mgr;            /*%< Interface manager. */
        isc_mutex_t             lock;
        int                     references;     /*%< Locked */
        unsigned int            generation;     /*%< Generation number. */
        isc_sockaddr_t          addr;           /*%< Address and port. */
        unsigned int            flags;          /*%< Interface characteristics */
        char                    name[32];       /*%< Null terminated. */
        dns_dispatch_t *        udpdispatch[MAX_UDP_DISPATCH];
                                                /*%< UDP dispatchers. */
        isc_socket_t *          tcpsocket;      /*%< TCP socket. */
        isc_dscp_t              dscp;           /*%< "listen-on" DSCP value */
        int                     ntcptarget;     /*%< Desired number of concurrent
                                                     TCP accepts */
        int                     ntcpcurrent;    /*%< Current ditto, locked */
        int                     nudpdispatch;   /*%< Number of UDP dispatches */
        ns_clientmgr_t *        clientmgr;      /*%< Client manager. */
        ISC_LINK(ns_interface_t) link;
};

/***
 *** Functions
 ***/

isc_result_t
ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
                       isc_socketmgr_t *socketmgr,
                       dns_dispatchmgr_t *dispatchmgr,
                       isc_task_t *task, ns_interfacemgr_t **mgrp);
/*%
 * Create a new interface manager.
 *
 * Initially, the new manager will not listen on any interfaces.
 * Call ns_interfacemgr_setlistenon() and/or ns_interfacemgr_setlistenon6()
 * to set nonempty listen-on lists.
 */

void
ns_interfacemgr_attach(ns_interfacemgr_t *source, ns_interfacemgr_t **target);

void
ns_interfacemgr_detach(ns_interfacemgr_t **targetp);

void
ns_interfacemgr_shutdown(ns_interfacemgr_t *mgr);

isc_boolean_t
ns_interfacemgr_islistening(ns_interfacemgr_t *mgr);
/*%
 * Return if the manager is listening on any interface. It can be called
 * after a scan or adjust.
 */

isc_result_t
ns_interfacemgr_scan(ns_interfacemgr_t *mgr, isc_boolean_t verbose);
/*%
 * Scan the operatings system's list of network interfaces
 * and create listeners when new interfaces are discovered.
 * Shut down the sockets for interfaces that go away.
 *
 * This should be called once on server startup and then
 * periodically according to the 'interface-interval' option
 * in named.conf.
 */

isc_result_t
ns_interfacemgr_adjust(ns_interfacemgr_t *mgr, ns_listenlist_t *list,
                       isc_boolean_t verbose);
/*%
 * Similar to ns_interfacemgr_scan(), but this function also tries to see the
 * need for an explicit listen-on when a list element in 'list' is going to
 * override an already-listening a wildcard interface.
 *
 * This function does not update localhost and localnets ACLs.
 *
 * This should be called once on server startup, after configuring views and
 * zones.
 */

void
ns_interfacemgr_setlistenon4(ns_interfacemgr_t *mgr, ns_listenlist_t *value);
/*%
 * Set the IPv4 "listen-on" list of 'mgr' to 'value'.
 * The previous IPv4 listen-on list is freed.
 */

void
ns_interfacemgr_setlistenon6(ns_interfacemgr_t *mgr, ns_listenlist_t *value);
/*%
 * Set the IPv6 "listen-on" list of 'mgr' to 'value'.
 * The previous IPv6 listen-on list is freed.
 */

dns_aclenv_t *
ns_interfacemgr_getaclenv(ns_interfacemgr_t *mgr);

void
ns_interface_attach(ns_interface_t *source, ns_interface_t **target);

void
ns_interface_detach(ns_interface_t **targetp);

void
ns_interface_shutdown(ns_interface_t *ifp);
/*%
 * Stop listening for queries on interface 'ifp'.
 * May safely be called multiple times.
 */

void
ns_interfacemgr_dumprecursing(FILE *f, ns_interfacemgr_t *mgr);

isc_boolean_t
ns_interfacemgr_listeningon(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr);

#endif /* NAMED_INTERFACEMGR_H */

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