dighost.c

bind 9.3结合mysql数据库

			if (!success) {
				success = ISC_TRUE;
				lookup_counter++;
				lookup = requeue_lookup(query->lookup,
							ISC_FALSE);
				cancel_lookup(query->lookup);
				lookup->doing_xfr = ISC_FALSE;
				if (!lookup->trace_root &&
				    section == DNS_SECTION_ANSWER)
					lookup->trace = ISC_FALSE;
				else
					lookup->trace = query->lookup->trace;
				lookup->ns_search_only =
					query->lookup->ns_search_only;
				lookup->trace_root = ISC_FALSE;
			}
			srv = make_server(namestr);
			debug("adding server %s", srv->servername);
			ISC_LIST_APPEND(lookup->my_server_list, srv, link);
			dns_rdata_reset(&rdata);
		}
	}

	if (lookup == NULL &&
	    section == DNS_SECTION_ANSWER &&
	    (query->lookup->trace || query->lookup->ns_search_only))
		return (followup_lookup(msg, query, DNS_SECTION_AUTHORITY));

	return numLookups;
}

/*
 * Create and queue a new lookup using the next origin from the search
 * list, read in setup_system().
 *
 * Return ISC_TRUE iff there was another searchlist entry.
 */
static isc_boolean_t
next_origin(dns_message_t *msg, dig_query_t *query) {
	dig_lookup_t *lookup;

	UNUSED(msg);

	INSIST(!free_now);

	debug("next_origin()");
	debug("following up %s", query->lookup->textname);

	if (!usesearch)
		/*
		 * We're not using a search list, so don't even think
		 * about finding the next entry.
		 */
		return (ISC_FALSE);
	if (query->lookup->origin == NULL)
		/*
		 * Then we just did rootorg; there's nothing left.
		 */
		return (ISC_FALSE);
	lookup = requeue_lookup(query->lookup, ISC_TRUE);
	lookup->origin = ISC_LIST_NEXT(query->lookup->origin, link);
	cancel_lookup(query->lookup);
	return (ISC_TRUE);
}

/*
 * Insert an SOA record into the sendmessage in a lookup.  Used for
 * creating IXFR queries.
 */
static void
insert_soa(dig_lookup_t *lookup) {
	isc_result_t result;
	dns_rdata_soa_t soa;
	dns_rdata_t *rdata = NULL;
	dns_rdatalist_t *rdatalist = NULL;
	dns_rdataset_t *rdataset = NULL;
	dns_name_t *soaname = NULL;

	debug("insert_soa()");
	soa.mctx = mctx;
	soa.serial = lookup->ixfr_serial;
	soa.refresh = 0;
	soa.retry = 0;
	soa.expire = 0;
	soa.minimum = 0;
	soa.common.rdclass = lookup->rdclass;
	soa.common.rdtype = dns_rdatatype_soa;

	dns_name_init(&soa.origin, NULL);
	dns_name_init(&soa.contact, NULL);

	dns_name_clone(dns_rootname, &soa.origin);
	dns_name_clone(dns_rootname, &soa.contact);

	isc_buffer_init(&lookup->rdatabuf, lookup->rdatastore,
			sizeof(lookup->rdatastore));

	result = dns_message_gettemprdata(lookup->sendmsg, &rdata);
	check_result(result, "dns_message_gettemprdata");

	result = dns_rdata_fromstruct(rdata, lookup->rdclass,
				      dns_rdatatype_soa, &soa,
				      &lookup->rdatabuf);
	check_result(result, "isc_rdata_fromstruct");

	result = dns_message_gettemprdatalist(lookup->sendmsg, &rdatalist);
	check_result(result, "dns_message_gettemprdatalist");

	result = dns_message_gettemprdataset(lookup->sendmsg, &rdataset);
	check_result(result, "dns_message_gettemprdataset");

	dns_rdatalist_init(rdatalist);
	rdatalist->type = dns_rdatatype_soa;
	rdatalist->rdclass = lookup->rdclass;
	rdatalist->covers = 0;
	rdatalist->ttl = 0;
	ISC_LIST_INIT(rdatalist->rdata);
	ISC_LIST_APPEND(rdatalist->rdata, rdata, link);

	dns_rdataset_init(rdataset);
	dns_rdatalist_tordataset(rdatalist, rdataset);

	result = dns_message_gettempname(lookup->sendmsg, &soaname);
	check_result(result, "dns_message_gettempname");
	dns_name_init(soaname, NULL);
	dns_name_clone(lookup->name, soaname);
	ISC_LIST_INIT(soaname->list);
	ISC_LIST_APPEND(soaname->list, rdataset, link);
	dns_message_addname(lookup->sendmsg, soaname, DNS_SECTION_AUTHORITY);
}

/*
 * Setup the supplied lookup structure, making it ready to start sending
 * queries to servers.  Create and initialize the message to be sent as
 * well as the query structures and buffer space for the replies.  If the
 * server list is empty, clone it from the system default list.
 */
void
setup_lookup(dig_lookup_t *lookup) {
	isc_result_t result;
	isc_uint32_t id;
	int len;
	dig_server_t *serv;
	dig_query_t *query;
	isc_buffer_t b;
	dns_compress_t cctx;
	char store[MXNAME];

	REQUIRE(lookup != NULL);
	INSIST(!free_now);

	debug("setup_lookup(%p)", lookup);

	result = dns_message_create(mctx, DNS_MESSAGE_INTENTRENDER,
				    &lookup->sendmsg);
	check_result(result, "dns_message_create");

	if (lookup->new_search) {
		debug("resetting lookup counter.");
		lookup_counter = 0;
	}

	if (ISC_LIST_EMPTY(lookup->my_server_list)) {
		debug("cloning server list");
		clone_server_list(server_list, &lookup->my_server_list);
	}
	result = dns_message_gettempname(lookup->sendmsg, &lookup->name);
	check_result(result, "dns_message_gettempname");
	dns_name_init(lookup->name, NULL);

	isc_buffer_init(&lookup->namebuf, lookup->namespace,
			sizeof(lookup->namespace));
	isc_buffer_init(&lookup->onamebuf, lookup->onamespace,
			sizeof(lookup->onamespace));

	/*
	 * If the name has too many dots, force the origin to be NULL
	 * (which produces an absolute lookup).  Otherwise, take the origin
	 * we have if there's one in the struct already.  If it's NULL,
	 * take the first entry in the searchlist iff either usesearch
	 * is TRUE or we got a domain line in the resolv.conf file.
	 */
	/* XXX New search here? */
	if ((count_dots(lookup->textname) >= ndots) || !usesearch)
		lookup->origin = NULL; /* Force abs lookup */
	else if (lookup->origin == NULL && lookup->new_search && usesearch) {
		lookup->origin = ISC_LIST_HEAD(search_list);
	}
	if (lookup->origin != NULL) {
		debug("trying origin %s", lookup->origin->origin);
		result = dns_message_gettempname(lookup->sendmsg,
						 &lookup->oname);
		check_result(result, "dns_message_gettempname");
		dns_name_init(lookup->oname, NULL);
		/* XXX Helper funct to conv char* to name? */
		len = strlen(lookup->origin->origin);
		isc_buffer_init(&b, lookup->origin->origin, len);
		isc_buffer_add(&b, len);
		result = dns_name_fromtext(lookup->oname, &b, dns_rootname,
					   ISC_FALSE, &lookup->onamebuf);
		if (result != ISC_R_SUCCESS) {
			dns_message_puttempname(lookup->sendmsg,
						&lookup->name);
			dns_message_puttempname(lookup->sendmsg,
						&lookup->oname);
			fatal("'%s' is not in legal name syntax (%s)",
			      lookup->origin->origin,
			      isc_result_totext(result));
		}
		if (lookup->trace && lookup->trace_root) {
			dns_name_clone(dns_rootname, lookup->name);
		} else {
			len = strlen(lookup->textname);
			isc_buffer_init(&b, lookup->textname, len);
			isc_buffer_add(&b, len);
			result = dns_name_fromtext(lookup->name, &b,
						   lookup->oname, ISC_FALSE,
						   &lookup->namebuf);
		}
		if (result != ISC_R_SUCCESS) {
			dns_message_puttempname(lookup->sendmsg,
						&lookup->name);
			dns_message_puttempname(lookup->sendmsg,
						&lookup->oname);
			fatal("'%s' is not in legal name syntax (%s)",
			      lookup->textname, isc_result_totext(result));
		}
		dns_message_puttempname(lookup->sendmsg, &lookup->oname);
	} else {
		debug("using root origin");
		if (lookup->trace && lookup->trace_root)
			dns_name_clone(dns_rootname, lookup->name);
		else {
			len = strlen(lookup->textname);
			isc_buffer_init(&b, lookup->textname, len);
			isc_buffer_add(&b, len);
			result = dns_name_fromtext(lookup->name, &b,
						   dns_rootname,
						   ISC_FALSE,
						   &lookup->namebuf);
		}
		if (result != ISC_R_SUCCESS) {
			dns_message_puttempname(lookup->sendmsg,
						&lookup->name);
			isc_buffer_init(&b, store, MXNAME);
			fatal("'%s' is not a legal name "
			      "(%s)", lookup->textname,
			      isc_result_totext(result));
		}
	}
	dns_name_format(lookup->name, store, sizeof(store));
	trying(store, lookup);
	INSIST(dns_name_isabsolute(lookup->name));

	isc_random_get(&id);
	lookup->sendmsg->id = (unsigned short)id & 0xFFFF;
	lookup->sendmsg->opcode = dns_opcode_query;
	lookup->msgcounter = 0;
	/*
	 * If this is a trace request, completely disallow recursion, since
	 * it's meaningless for traces.
	 */
	if (lookup->trace || (lookup->ns_search_only && !lookup->trace_root))
		lookup->recurse = ISC_FALSE;

	if (lookup->recurse &&
	    lookup->rdtype != dns_rdatatype_axfr &&
	    lookup->rdtype != dns_rdatatype_ixfr) {
		debug("recursive query");
		lookup->sendmsg->flags |= DNS_MESSAGEFLAG_RD;
	}

	/* XXX aaflag */
	if (lookup->aaonly) {
		debug("AA query");
		lookup->sendmsg->flags |= DNS_MESSAGEFLAG_AA;
	}

	if (lookup->adflag) {
		debug("AD query");
		lookup->sendmsg->flags |= DNS_MESSAGEFLAG_AD;
	}

	if (lookup->cdflag) {
		debug("CD query");
		lookup->sendmsg->flags |= DNS_MESSAGEFLAG_CD;
	}

	dns_message_addname(lookup->sendmsg, lookup->name,
			    DNS_SECTION_QUESTION);

	if (lookup->trace && lookup->trace_root) {
		lookup->qrdtype = lookup->rdtype;
		lookup->rdtype = dns_rdatatype_ns;
	}

	if ((lookup->rdtype == dns_rdatatype_axfr) ||
	    (lookup->rdtype == dns_rdatatype_ixfr)) {
		lookup->doing_xfr = ISC_TRUE;
		/*
		 * Force TCP mode if we're doing an xfr.
		 * XXX UDP ixfr's would be useful
		 */
		lookup->tcp_mode = ISC_TRUE;
	}

	add_question(lookup->sendmsg, lookup->name, lookup->rdclass,
		     lookup->rdtype);

	/* add_soa */
	if (lookup->rdtype == dns_rdatatype_ixfr)
		insert_soa(lookup);

	/* XXX Insist this? */
	lookup->tsigctx = NULL;
	lookup->querysig = NULL;
	if (key != NULL) {
		debug("initializing keys");
		result = dns_message_settsigkey(lookup->sendmsg, key);
		check_result(result, "dns_message_settsigkey");
	}

	lookup->sendspace = isc_mempool_get(commctx);
	if (lookup->sendspace == NULL)
		fatal("memory allocation failure");

	result = dns_compress_init(&cctx, -1, mctx);
	check_result(result, "dns_compress_init");

	debug("starting to render the message");
	isc_buffer_init(&lookup->sendbuf, lookup->sendspace, COMMSIZE);
	result = dns_message_renderbegin(lookup->sendmsg, &cctx,
					 &lookup->sendbuf);
	check_result(result, "dns_message_renderbegin");
	if (lookup->udpsize > 0 || lookup->dnssec) {
		if (lookup->udpsize == 0)
			lookup->udpsize = 2048;
		add_opt(lookup->sendmsg, lookup->udpsize, lookup->dnssec);
	}

	result = dns_message_rendersection(lookup->sendmsg,
					   DNS_SECTION_QUESTION, 0);
	check_result(result, "dns_message_rendersection");
	result = dns_message_rendersection(lookup->sendmsg,
					   DNS_SECTION_AUTHORITY, 0);
	check_result(result, "dns_message_rendersection");
	result = dns_message_renderend(lookup->sendmsg);
	check_result(result, "dns_message_renderend");
	debug("done rendering");

	dns_compress_invalidate(&cctx);

	/*
	 * Force TCP mode if the request is larger than 512 bytes.
	 */
	if (isc_buffer_usedlength(&lookup->sendbuf) > 512)
		lookup->tcp_mode = ISC_TRUE;

	lookup->pending = ISC_FALSE;

	for (serv = ISC_LIST_HEAD(lookup->my_server_list);
	     serv != NULL;
	     serv = ISC_LIST_NEXT(serv, link)) {
		query = isc_mem_allocate(mctx, sizeof(dig_query_t));
		if (query == NULL)
			fatal("memory allocation failure in %s:%d",
			      __FILE__, __LINE__);
		debug("create query %p linked to lookup %p",
		       query, lookup);
		query->lookup = lookup;
		query->waiting_connect = ISC_FALSE;
		query->recv_made = ISC_FALSE;
		query->first_pass = ISC_TRUE;
		query->first_soa_rcvd = ISC_FALSE;
		query->second_rr_rcvd = ISC_FALSE;
		query->first_repeat_rcvd = ISC_FALSE;
		query->warn_id = ISC_TRUE;
		query->first_rr_serial = 0;
		query->second_rr_serial = 0;
		query->servname = serv->servername;
		query->rr_count = 0;
		query->msg_count = 0;
		ISC_LINK_INIT(query, link);
		ISC_LIST_INIT(query->recvlist);
		ISC_LIST_INIT(query->lengthlist);
		query->sock = NULL;
		query->recvspace = isc_mempool_get(commctx);
		if (query->recvspace == NULL)
			fatal("memory allocation failure");

		isc_buffer_init(&query->recvbuf, query->recvspace, COMMSIZE);
		isc_buffer_init(&query->lengthbuf, query->lengthspace, 2);
		isc_buffer_init(&query->slbuf, query->slspace, 2);

		ISC_LINK_INIT(query, link);
		ISC_LIST_ENQUEUE(lookup->q, query, link);
	}
	/* XXX qrflag, print_query, etc... */
	if (!ISC_LIST_EMPTY(lookup->q) && qr) {
		printmessage(ISC_LIST_HEAD(lookup->q), lookup->sendmsg,
			     ISC_TRUE);
	}
}

/*
 * Event handler for send completion.  Track send counter, and clear out
 * the query if the send was canceled.
 */
static void
send_done(isc_task_t *_task, isc_event_t *event) {
	REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);

	UNUSED(_task);

	LOCK_LOOKUP;

	isc_event_free(&event);

	debug("send_done()");
	sendcount--;
	debug("sendcount=%d", sendcount);
	INSIST(sendcount >= 0);
	check_if_done();
	UNLOCK_LOOKUP;
}

/*
 * Cancel a lookup, sending isc_socket_cancel() requests to all outstanding
 * IO sockets.  The cancel handlers should take care of cleaning up the
 * query and lookup structures
 */
static void
cancel_lookup(dig_lookup_t *lookup) {
	dig_query_t *query, *next;

	debug("cancel_lookup()");
	query = ISC_LIST_HEAD(lookup->q);
	while (query != NULL) {
		next = ISC_LIST_NEXT(query, link);
		if (query->sock != NULL) {
			isc_socket_cancel(query->sock, global_task,
					  ISC_SOCKCANCEL_ALL);
			check_if_done();
		} else {
			clear_query(query);
		}
		query = next;
	}
	if (lookup->timer != NULL)
		isc_timer_detach(&lookup->timer);
	lookup->pending = ISC_FALSE;
	lookup->retries = 0;
}

static void
bringup_timer(dig_query_t *query, unsigned int default_timeout) {
	dig_lookup_t *l;
	unsigned int local_timeout;
	isc_result_t result;

	debug("bringup_timer()");
	/*
	 * If the timer already exists, that means we're calling this
	 * a second time (for a retry).  Don't need to recreate it,
	 * just reset it.
	 */
	l = query->lookup;
	if (ISC_LIST_NEXT(query, link) != NULL)
		local_timeout = SERVER_TIMEOUT;
	else {
		if (timeout == 0) {
			local_timeout = default_timeout;
		} else
			local_timeout = timeout;