lwdclient.h

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/*
 * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  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: lwdclient.h,v 1.20 2009/01/17 23:47:42 tbox Exp $ */

#ifndef NAMED_LWDCLIENT_H
#define NAMED_LWDCLIENT_H 1

/*! \file */

#include <isc/event.h>
#include <isc/eventclass.h>
#include <isc/netaddr.h>
#include <isc/sockaddr.h>
#include <isc/types.h>

#include <dns/fixedname.h>
#include <dns/types.h>

#include <lwres/lwres.h>

#include <named/lwsearch.h>

#define LWRD_EVENTCLASS         ISC_EVENTCLASS(4242)

#define LWRD_SHUTDOWN           (LWRD_EVENTCLASS + 0x0001)

/*% Lightweight Resolver Daemon Client */
struct ns_lwdclient {
        isc_sockaddr_t          address;        /*%< where to reply */
        struct in6_pktinfo      pktinfo;
        isc_boolean_t           pktinfo_valid;
        ns_lwdclientmgr_t       *clientmgr;     /*%< our parent */
        ISC_LINK(ns_lwdclient_t) link;
        unsigned int            state;
        void                    *arg;           /*%< packet processing state */

        /*
         * Received data info.
         */
        unsigned char           buffer[LWRES_RECVLENGTH]; /*%< receive buffer */
        isc_uint32_t            recvlength;     /*%< length recv'd */
        lwres_lwpacket_t        pkt;

        /*%
         * Send data state.  If sendbuf != buffer (that is, the send buffer
         * isn't our receive buffer) it will be freed to the lwres_context_t.
         */
        unsigned char          *sendbuf;
        isc_uint32_t            sendlength;
        isc_buffer_t            recv_buffer;

        /*%
         * gabn (get address by name) state info.
         */
        dns_adbfind_t           *find;
        dns_adbfind_t           *v4find;
        dns_adbfind_t           *v6find;
        unsigned int            find_wanted;    /*%< Addresses we want */
        dns_fixedname_t         query_name;
        dns_fixedname_t         target_name;
        ns_lwsearchctx_t        searchctx;
        lwres_gabnresponse_t    gabn;

        /*%
         * gnba (get name by address) state info.
         */
        lwres_gnbaresponse_t    gnba;
        dns_byaddr_t           *byaddr;
        unsigned int            options;
        isc_netaddr_t           na;

        /*%
         * grbn (get rrset by name) state info.
         *
         * Note: this also uses target_name and searchctx.
         */
        lwres_grbnresponse_t    grbn;
        dns_lookup_t           *lookup;
        dns_rdatatype_t         rdtype;

        /*%
         * Alias and address info.  This is copied up to the gabn/gnba
         * structures eventually.
         *
         * XXXMLG We can keep all of this in a client since we only service
         * three packet types right now.  If we started handling more,
         * we'd need to use "arg" above and allocate/destroy things.
         */
        char                   *aliases[LWRES_MAX_ALIASES];
        isc_uint16_t            aliaslen[LWRES_MAX_ALIASES];
        lwres_addr_t            addrs[LWRES_MAX_ADDRS];
};

/*%
 * Client states.
 *
 * _IDLE        The client is not doing anything at all.
 *
 * _RECV        The client is waiting for data after issuing a socket recv().
 *
 * _RECVDONE    Data has been received, and is being processed.
 *
 * _FINDWAIT    An adb (or other) request was made that cannot be satisfied
 *              immediately.  An event will wake the client up.
 *
 * _SEND        All data for a response has completed, and a reply was
 *              sent via a socket send() call.
 *
 * Badly formatted state table:
 *
 *      IDLE -> RECV when client has a recv() queued.
 *
 *      RECV -> RECVDONE when recvdone event received.
 *
 *      RECVDONE -> SEND if the data for a reply is at hand.
 *      RECVDONE -> FINDWAIT if more searching is needed, and events will
 *              eventually wake us up again.
 *
 *      FINDWAIT -> SEND when enough data was received to reply.
 *
 *      SEND -> IDLE when a senddone event was received.
 *
 *      At any time -> IDLE on error.  Sometimes this will be -> SEND
 *      instead, if enough data is on hand to reply with a meaningful
 *      error.
 *
 *      Packets which are badly formatted may or may not get error returns.
 */
#define NS_LWDCLIENT_STATEIDLE          1
#define NS_LWDCLIENT_STATERECV          2
#define NS_LWDCLIENT_STATERECVDONE      3
#define NS_LWDCLIENT_STATEFINDWAIT      4
#define NS_LWDCLIENT_STATESEND          5
#define NS_LWDCLIENT_STATESENDDONE      6

#define NS_LWDCLIENT_ISIDLE(c)          \
                        ((c)->state == NS_LWDCLIENT_STATEIDLE)
#define NS_LWDCLIENT_ISRECV(c)          \
                        ((c)->state == NS_LWDCLIENT_STATERECV)
#define NS_LWDCLIENT_ISRECVDONE(c)      \
                        ((c)->state == NS_LWDCLIENT_STATERECVDONE)
#define NS_LWDCLIENT_ISFINDWAIT(c)      \
                        ((c)->state == NS_LWDCLIENT_STATEFINDWAIT)
#define NS_LWDCLIENT_ISSEND(c)          \
                        ((c)->state == NS_LWDCLIENT_STATESEND)

/*%
 * Overall magic test that means we're not idle.
 */
#define NS_LWDCLIENT_ISRUNNING(c)       (!NS_LWDCLIENT_ISIDLE(c))

#define NS_LWDCLIENT_SETIDLE(c)         \
                        ((c)->state = NS_LWDCLIENT_STATEIDLE)
#define NS_LWDCLIENT_SETRECV(c)         \
                        ((c)->state = NS_LWDCLIENT_STATERECV)
#define NS_LWDCLIENT_SETRECVDONE(c)     \
                        ((c)->state = NS_LWDCLIENT_STATERECVDONE)
#define NS_LWDCLIENT_SETFINDWAIT(c)     \
                        ((c)->state = NS_LWDCLIENT_STATEFINDWAIT)
#define NS_LWDCLIENT_SETSEND(c)         \
                        ((c)->state = NS_LWDCLIENT_STATESEND)
#define NS_LWDCLIENT_SETSENDDONE(c)     \
                        ((c)->state = NS_LWDCLIENT_STATESENDDONE)

/*% lightweight daemon client manager */
struct ns_lwdclientmgr {
        ns_lwreslistener_t     *listener;
        isc_mem_t              *mctx;
        isc_socket_t           *sock;           /*%< socket to use */
        dns_view_t             *view;
        lwres_context_t        *lwctx;          /*%< lightweight proto context */
        isc_task_t             *task;           /*%< owning task */
        unsigned int            flags;
        ISC_LINK(ns_lwdclientmgr_t)     link;
        ISC_LIST(ns_lwdclient_t)        idle;           /*%< idle client slots */
        ISC_LIST(ns_lwdclient_t)        running;        /*%< running clients */
};

#define NS_LWDCLIENTMGR_FLAGRECVPENDING         0x00000001
#define NS_LWDCLIENTMGR_FLAGSHUTTINGDOWN        0x00000002

isc_result_t
ns_lwdclientmgr_create(ns_lwreslistener_t *, unsigned int, isc_taskmgr_t *);

void
ns_lwdclient_initialize(ns_lwdclient_t *, ns_lwdclientmgr_t *);

isc_result_t
ns_lwdclient_startrecv(ns_lwdclientmgr_t *);

void
ns_lwdclient_stateidle(ns_lwdclient_t *);

void
ns_lwdclient_recv(isc_task_t *, isc_event_t *);

void
ns_lwdclient_shutdown(isc_task_t *, isc_event_t *);

void
ns_lwdclient_send(isc_task_t *, isc_event_t *);

isc_result_t
ns_lwdclient_sendreply(ns_lwdclient_t *client, isc_region_t *r);

/*
 * Processing functions of various types.
 */
void ns_lwdclient_processgabn(ns_lwdclient_t *, lwres_buffer_t *);
void ns_lwdclient_processgnba(ns_lwdclient_t *, lwres_buffer_t *);
void ns_lwdclient_processgrbn(ns_lwdclient_t *, lwres_buffer_t *);
void ns_lwdclient_processnoop(ns_lwdclient_t *, lwres_buffer_t *);

void ns_lwdclient_errorpktsend(ns_lwdclient_t *, isc_uint32_t);

void ns_lwdclient_log(int level, const char *format, ...)
     ISC_FORMAT_PRINTF(2, 3);

#endif /* NAMED_LWDCLIENT_H */

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