lwdgabn.c

bind 9.3结合mysql数据库

	/*
	 * Save this name away as the current real name.
	 */
	client->gabn.realname = (char *) b.base + b.used;
	client->gabn.realnamelen = client->recv_buffer.used - b.used;

	return (ISC_R_SUCCESS);
}

static void
process_gabn_finddone(isc_task_t *task, isc_event_t *ev) {
	ns_lwdclient_t *client = ev->ev_arg;
	isc_eventtype_t evtype;
	isc_boolean_t claimed;

	ns_lwdclient_log(50, "find done for task %p, client %p", task, client);

	evtype = ev->ev_type;
	isc_event_free(&ev);

	/*
	 * No more info to be had?  If so, we have all the good stuff
	 * right now, so we can render things.
	 */
	claimed = ISC_FALSE;
	if (evtype == DNS_EVENT_ADBNOMOREADDRESSES) {
		if (NEED_V4(client)) {
			client->v4find = client->find;
			claimed = ISC_TRUE;
		}
		if (NEED_V6(client)) {
			client->v6find = client->find;
			claimed = ISC_TRUE;
		}
		if (client->find != NULL) {
			if (claimed)
				client->find = NULL;
			else
				dns_adb_destroyfind(&client->find);

		}
		generate_reply(client);
		return;
	}

	/*
	 * We probably don't need this find anymore.  We're either going to
	 * reissue it, or an error occurred.  Either way, we're done with
	 * it.
	 */
	if ((client->find != client->v4find)
	    && (client->find != client->v6find)) {
		dns_adb_destroyfind(&client->find);
	} else {
		client->find = NULL;
	}

	/*
	 * We have some new information we can gather.  Run off and fetch
	 * it.
	 */
	if (evtype == DNS_EVENT_ADBMOREADDRESSES) {
		restart_find(client);
		return;
	}

	/*
	 * An error or other strangeness happened.  Drop this query.
	 */
	cleanup_gabn(client);
	ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}

static void
restart_find(ns_lwdclient_t *client) {
	unsigned int options;
	isc_result_t result;
	isc_boolean_t claimed;

	ns_lwdclient_log(50, "starting find for client %p", client);

	/*
	 * Issue a find for the name contained in the request.  We won't
	 * set the bit that says "anything is good enough" -- we want it
	 * all.
	 */
	options = 0;
	options |= DNS_ADBFIND_WANTEVENT;
	options |= DNS_ADBFIND_RETURNLAME;

	/*
	 * Set the bits up here to mark that we want this address family
	 * and that we do not currently have a find pending.  We will
	 * set that bit again below if it turns out we will get an event.
	 */
	if (NEED_V4(client))
		options |= DNS_ADBFIND_INET;
	if (NEED_V6(client))
		options |= DNS_ADBFIND_INET6;

 find_again:
	INSIST(client->find == NULL);
	result = dns_adb_createfind(client->clientmgr->view->adb,
				    client->clientmgr->task,
				    process_gabn_finddone, client,
				    dns_fixedname_name(&client->target_name),
				    dns_rootname, options, 0,
				    dns_fixedname_name(&client->target_name),
				    client->clientmgr->view->dstport,
				    &client->find);

	/*
	 * Did we get an alias?  If so, save it and re-issue the query.
	 */
	if (result == DNS_R_ALIAS) {
		ns_lwdclient_log(50, "found alias, restarting query");
		dns_adb_destroyfind(&client->find);
		cleanup_gabn(client);
		result = add_alias(client);
		if (result != ISC_R_SUCCESS) {
			ns_lwdclient_log(50,
					 "out of buffer space adding alias");
			ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
			return;
		}
		goto find_again;
	}

	ns_lwdclient_log(50, "find returned %d (%s)", result,
			 isc_result_totext(result));

	/*
	 * Did we get an error?
	 */
	if (result != ISC_R_SUCCESS) {
		if (client->find != NULL)
			dns_adb_destroyfind(&client->find);
		cleanup_gabn(client);
		ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
		return;
	}

	claimed = ISC_FALSE;

	/*
	 * Did we get our answer to V4 addresses?
	 */
	if (NEED_V4(client)
	    && ((client->find->query_pending & DNS_ADBFIND_INET) == 0)) {
		ns_lwdclient_log(50, "client %p ipv4 satisfied by find %p",
				 client, client->find);
		claimed = ISC_TRUE;
		client->v4find = client->find;
	}

	/*
	 * Did we get our answer to V6 addresses?
	 */
	if (NEED_V6(client)
	    && ((client->find->query_pending & DNS_ADBFIND_INET6) == 0)) {
		ns_lwdclient_log(50, "client %p ipv6 satisfied by find %p",
				 client, client->find);
		claimed = ISC_TRUE;
		client->v6find = client->find;
	}

	/*
	 * If we're going to get an event, set our internal pending flag
	 * and return.  When we get an event back we'll do the right
	 * thing, basically by calling this function again, perhaps with a
	 * new target name.
	 *
	 * If we have both v4 and v6, and we are still getting an event,
	 * we have a programming error, so die hard.
	 */
	if ((client->find->options & DNS_ADBFIND_WANTEVENT) != 0) {
		ns_lwdclient_log(50, "event will be sent");
		INSIST(client->v4find == NULL || client->v6find == NULL);
		return;
	}
	ns_lwdclient_log(50, "no event will be sent");
	if (claimed)
		client->find = NULL;
	else
		dns_adb_destroyfind(&client->find);

	/*
	 * We seem to have everything we asked for, or at least we are
	 * able to respond with things we've learned.
	 */

	generate_reply(client);
}

static isc_result_t
start_find(ns_lwdclient_t *client) {
	isc_result_t result;

	/*
	 * Initialize the real name and alias arrays in the reply we're
	 * going to build up.
	 */
	init_gabn(client);

	result = store_realname(client);
	if (result != ISC_R_SUCCESS)
		return (result);
	restart_find(client);
	return (ISC_R_SUCCESS);

}

static void
init_gabn(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->gabn.naliases = 0;
	client->gabn.naddrs = 0;
	client->gabn.realname = NULL;
	client->gabn.aliases = client->aliases;
	client->gabn.realnamelen = 0;
	client->gabn.aliaslen = client->aliaslen;
	LWRES_LIST_INIT(client->gabn.addrs);
	client->gabn.base = NULL;
	client->gabn.baselen = 0;

	/*
	 * Set up the internal buffer to point to the receive region.
	 */
	isc_buffer_init(&client->recv_buffer, client->buffer, LWRES_RECVLENGTH);
}

/*
 * When we are called, we can be assured that:
 *
 *	client->sockaddr contains the address we need to reply to,
 *
 *	client->pkt contains the packet header data,
 *
 *	the packet "checks out" overall -- any MD5 hashes or crypto
 *	bits have been verified,
 *
 *	"b" points to the remaining data after the packet header
 *	was parsed off.
 *
 *	We are in a the RECVDONE state.
 *
 * From this state we will enter the SEND state if we happen to have
 * everything we need or we need to return an error packet, or to the
 * FINDWAIT state if we need to look things up.
 */
void
ns_lwdclient_processgabn(ns_lwdclient_t *client, lwres_buffer_t *b) {
	isc_result_t result;
	lwres_gabnrequest_t *req;
	ns_lwdclientmgr_t *cm;
	isc_buffer_t namebuf;

	REQUIRE(NS_LWDCLIENT_ISRECVDONE(client));

	cm = client->clientmgr;
	req = NULL;

	result = lwres_gabnrequest_parse(client->clientmgr->lwctx,
					 b, &client->pkt, &req);
	if (result != LWRES_R_SUCCESS)
		goto out;
	if (req->name == NULL)
		goto out;

	isc_buffer_init(&namebuf, req->name, req->namelen);
	isc_buffer_add(&namebuf, req->namelen);

	dns_fixedname_init(&client->target_name);
	dns_fixedname_init(&client->query_name);
	result = dns_name_fromtext(dns_fixedname_name(&client->query_name),
				   &namebuf, NULL, ISC_FALSE, NULL);
	if (result != ISC_R_SUCCESS)
		goto out;
	ns_lwsearchctx_init(&client->searchctx,
			    cm->listener->manager->search,
			    dns_fixedname_name(&client->query_name),
			    cm->listener->manager->ndots);
	ns_lwsearchctx_first(&client->searchctx);

	client->find_wanted = req->addrtypes;
	ns_lwdclient_log(50, "client %p looking for addrtypes %08x",
			 client, client->find_wanted);

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

	/*
	 * Start the find.
	 */
	result = start_find(client);
	if (result != ISC_R_SUCCESS)
		goto out;

	return;

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

	ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}