lwdgnba.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2008, 2014  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000-2002  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: lwdgnba.c,v 1.22 2008/01/14 23:46:56 tbox Exp $ */

/*! \file */

#include <config.h>

#include <isc/socket.h>
#include <isc/string.h>         /* Required for HP/UX (and others?) */
#include <isc/util.h>

#include <dns/adb.h>
#include <dns/byaddr.h>
#include <dns/result.h>

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

static void start_byaddr(ns_lwdclient_t *);

static void
byaddr_done(isc_task_t *task, isc_event_t *event) {
        ns_lwdclient_t *client;
        ns_lwdclientmgr_t *cm;
        dns_byaddrevent_t *bevent;
        int lwres;
        lwres_buffer_t lwb;
        dns_name_t *name;
        isc_result_t result;
        lwres_result_t lwresult;
        isc_region_t r;
        isc_buffer_t b;
        lwres_gnbaresponse_t *gnba;
        isc_uint16_t naliases;

        UNUSED(task);

        lwb.base = NULL;
        client = event->ev_arg;
        cm = client->clientmgr;
        INSIST(client->byaddr == (dns_byaddr_t *)event->ev_sender);

        bevent = (dns_byaddrevent_t *)event;
        gnba = &client->gnba;

        ns_lwdclient_log(50, "byaddr event result = %s",
                         isc_result_totext(bevent->result));

        result = bevent->result;
        if (result != ISC_R_SUCCESS) {
                dns_byaddr_destroy(&client->byaddr);
                isc_event_free(&event);
                bevent = NULL;

                if (client->na.family != AF_INET6 ||
                    (client->options & DNS_BYADDROPT_IPV6INT) != 0) {
                        if (result == DNS_R_NCACHENXDOMAIN ||
                            result == DNS_R_NCACHENXRRSET ||
                            result == DNS_R_NXDOMAIN ||
                            result == DNS_R_NXRRSET)
                                lwresult = LWRES_R_NOTFOUND;
                        else
                                lwresult = LWRES_R_FAILURE;
                        ns_lwdclient_errorpktsend(client, lwresult);
                        return;
                }

                /*
                 * Fall back to ip6.int reverse if the default ip6.arpa
                 * fails.
                 */
                client->options |= DNS_BYADDROPT_IPV6INT;

                start_byaddr(client);
                return;
        }

        for (name = ISC_LIST_HEAD(bevent->names);
             name != NULL;
             name = ISC_LIST_NEXT(name, link))
        {
                b = client->recv_buffer;

                result = dns_name_totext(name, ISC_TRUE, &client->recv_buffer);
                if (result != ISC_R_SUCCESS)
                        goto out;
                ns_lwdclient_log(50, "found name '%.*s'",
                                 (int)(client->recv_buffer.used - b.used),
                                 (char *)(b.base) + b.used);
                if (gnba->realname == NULL) {
                        gnba->realname = (char *)(b.base) + b.used;
                        gnba->realnamelen = client->recv_buffer.used - b.used;
                } else {
                        naliases = gnba->naliases;
                        if (naliases >= LWRES_MAX_ALIASES)
                                break;
                        gnba->aliases[naliases] = (char *)(b.base) + b.used;
                        gnba->aliaslen[naliases] =
                                client->recv_buffer.used - b.used;
                        gnba->naliases++;
                }
        }

        dns_byaddr_destroy(&client->byaddr);
        isc_event_free(&event);

        /*
         * Render the packet.
         */
        client->pkt.recvlength = LWRES_RECVLENGTH;
        client->pkt.authtype = 0; /* XXXMLG */
        client->pkt.authlength = 0;
        client->pkt.result = LWRES_R_SUCCESS;

        lwres = lwres_gnbaresponse_render(cm->lwctx,
                                          gnba, &client->pkt, &lwb);
        if (lwres != LWRES_R_SUCCESS)
                goto out;

        r.base = lwb.base;
        r.length = lwb.used;
        client->sendbuf = r.base;
        client->sendlength = r.length;
        result = ns_lwdclient_sendreply(client, &r);
        if (result != ISC_R_SUCCESS)
                goto out;

        NS_LWDCLIENT_SETSEND(client);

        return;

 out:
        if (client->byaddr != NULL)
                dns_byaddr_destroy(&client->byaddr);
        if (lwb.base != NULL)
                lwres_context_freemem(cm->lwctx,
                                      lwb.base, lwb.length);

        if (event != NULL)
                isc_event_free(&event);
}

static void
start_byaddr(ns_lwdclient_t *client) {
        isc_result_t result;
        ns_lwdclientmgr_t *cm;

        cm = client->clientmgr;

        INSIST(client->byaddr == NULL);

        result = dns_byaddr_create(cm->mctx, &client->na, cm->view,
                                   client->options, cm->task, byaddr_done,
                                   client, &client->byaddr);
        if (result != ISC_R_SUCCESS) {
                ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
                return;
        }
}

static void
init_gnba(ns_lwdclient_t *client) {
        int i;

        /*
         * Initialize the real name and alias arrays in the reply we're
         * going to build up.
         */
        for (i = 0; i < LWRES_MAX_ALIASES; i++) {
                client->aliases[i] = NULL;
                client->aliaslen[i] = 0;
        }
        for (i = 0; i < LWRES_MAX_ADDRS; i++) {
                client->addrs[i].family = 0;
                client->addrs[i].length = 0;
                memset(client->addrs[i].address, 0, LWRES_ADDR_MAXLEN);
                LWRES_LINK_INIT(&client->addrs[i], link);
        }

        client->gnba.naliases = 0;
        client->gnba.realname = NULL;
        client->gnba.aliases = client->aliases;
        client->gnba.realnamelen = 0;
        client->gnba.aliaslen = client->aliaslen;
        client->gnba.base = NULL;
        client->gnba.baselen = 0;
        isc_buffer_init(&client->recv_buffer, client->buffer, LWRES_RECVLENGTH);
}

void
ns_lwdclient_processgnba(ns_lwdclient_t *client, lwres_buffer_t *b) {
        lwres_gnbarequest_t *req;
        isc_result_t result;
        isc_sockaddr_t sa;
        ns_lwdclientmgr_t *cm;

        REQUIRE(NS_LWDCLIENT_ISRECVDONE(client));
        INSIST(client->byaddr == NULL);

        cm = client->clientmgr;
        req = NULL;

        result = lwres_gnbarequest_parse(cm->lwctx,
                                         b, &client->pkt, &req);
        if (result != LWRES_R_SUCCESS)
                goto out;

        client->options = 0;
        if (req->addr.family == LWRES_ADDRTYPE_V4) {
                client->na.family = AF_INET;
                if (req->addr.length != 4)
                        goto out;
                memmove(&client->na.type.in, req->addr.address, 4);
        } else if (req->addr.family == LWRES_ADDRTYPE_V6) {
                client->na.family = AF_INET6;
                if (req->addr.length != 16)
                        goto out;
                memmove(&client->na.type.in6, req->addr.address, 16);
        } else {
                goto out;
        }
        isc_sockaddr_fromnetaddr(&sa, &client->na, 53);

        ns_lwdclient_log(50, "client %p looking for addrtype %08x",
                         client, req->addr.family);

        /*
         * We no longer need to keep this around.
         */
        lwres_gnbarequest_free(cm->lwctx, &req);

        /*
         * Initialize the real name and alias arrays in the reply we're
         * going to build up.
         */
        init_gnba(client);
        client->options = 0;

        /*
         * Start the find.
         */
        start_byaddr(client);

        return;

        /*
         * We're screwed.  Return an error packet to our caller.
         */
 out:
        if (req != NULL)
                lwres_gnbarequest_free(cm->lwctx, &req);

        ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}

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