lwdgabn.c

bind-3.2.

/*
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM 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: lwdgabn.c,v 1.13 2001/01/22 22:12:16 bwelling Exp $ */

#include <config.h>

#include <stdlib.h>

#include <isc/netaddr.h>
#include <isc/sockaddr.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/events.h>
#include <dns/result.h>

#include <named/types.h>
#include <named/lwaddr.h>
#include <named/lwdclient.h>
#include <named/lwresd.h>
#include <named/lwsearch.h>
#include <named/sortlist.h>

#define NEED_V4(c)	((((c)->find_wanted & LWRES_ADDRTYPE_V4) != 0) \
			 && ((c)->v4find == NULL))
#define NEED_V6(c)	((((c)->find_wanted & LWRES_ADDRTYPE_V6) != 0) \
			 && ((c)->v6find == NULL))

static isc_result_t start_find(ns_lwdclient_t *);
static void restart_find(ns_lwdclient_t *);
static void init_gabn(ns_lwdclient_t *);

/*
 * Destroy any finds.  This can be used to "start over from scratch" and
 * should only be called when events are _not_ being generated by the finds.
 */
static void
cleanup_gabn(ns_lwdclient_t *client) {
	ns_lwdclient_log(50, "cleaning up client %p", client);

	if (client->v6find != NULL) {
		if (client->v6find == client->v4find)
			client->v6find = NULL;
		else
			dns_adb_destroyfind(&client->v6find);
	}
	if (client->v4find != NULL)
		dns_adb_destroyfind(&client->v4find);
}

static void
setup_addresses(ns_lwdclient_t *client, dns_adbfind_t *find, unsigned int at) {
	dns_adbaddrinfo_t *ai;
	lwres_addr_t *addr;
	int af;
	const struct sockaddr *sa;
	isc_result_t result;

	if (at == DNS_ADBFIND_INET)
		af = AF_INET;
	else
		af = AF_INET6;

	ai = ISC_LIST_HEAD(find->list);
	while (ai != NULL && client->gabn.naddrs < LWRES_MAX_ADDRS) {
		sa = &ai->sockaddr.type.sa;
		if (sa->sa_family != af)
			goto next;

		addr = &client->addrs[client->gabn.naddrs];

		result = lwaddr_lwresaddr_fromsockaddr(addr, &ai->sockaddr);
		if (result != ISC_R_SUCCESS)
			goto next;

		ns_lwdclient_log(50, "adding address %p, family %d, length %d",
				 addr->address, addr->family, addr->length);

		client->gabn.naddrs++;
		REQUIRE(!LWRES_LINK_LINKED(addr, link));
		LWRES_LIST_APPEND(client->gabn.addrs, addr, link);

	next:
		ai = ISC_LIST_NEXT(ai, publink);
	}
}

typedef struct {
	isc_netaddr_t address;
	int rank;
} rankedaddress;

static int
addr_compare(const void *av, const void *bv) {
	const rankedaddress *a = (const rankedaddress *) av;
	const rankedaddress *b = (const rankedaddress *) bv;
	return (a->rank - b->rank);
}

static void
sort_addresses(ns_lwdclient_t *client) {
	unsigned int naddrs;
	rankedaddress *addrs;
	isc_netaddr_t remote;
	dns_addressorderfunc_t order;
	void *arg;
	ns_lwresd_t *lwresd = client->clientmgr->listener->manager;
	unsigned int i;
	isc_result_t result;

	naddrs = client->gabn.naddrs;

	if (naddrs <= 1 || lwresd->view->sortlist == NULL)
		return;

	addrs = isc_mem_get(lwresd->mctx, sizeof(rankedaddress) * naddrs);
	if (addrs == NULL)
		return;

	isc_netaddr_fromsockaddr(&remote, &client->address);
	ns_sortlist_byaddrsetup(lwresd->view->sortlist,
				&remote, &order, &arg);
	if (order == NULL) {
		isc_mem_put(lwresd->mctx, addrs,
			    sizeof(rankedaddress) * naddrs);
		return;
	}
	for (i = 0; i < naddrs; i++) {
		result = lwaddr_netaddr_fromlwresaddr(&addrs[i].address,
						      &client->addrs[i]);
		INSIST(result == ISC_R_SUCCESS);
		addrs[i].rank = (*order)(&addrs[i].address, arg);
	}
	qsort(addrs, naddrs, sizeof(rankedaddress), addr_compare);
	for (i = 0; i < naddrs; i++) {
		result = lwaddr_lwresaddr_fromnetaddr(&client->addrs[i],
						      &addrs[i].address);
		INSIST(result == ISC_R_SUCCESS);
	}

	isc_mem_put(lwresd->mctx, addrs, sizeof(rankedaddress) * naddrs);
}

static void
generate_reply(ns_lwdclient_t *client) {
	isc_result_t result;
	int lwres;
	isc_region_t r;
	lwres_buffer_t lwb;
	ns_lwdclientmgr_t *cm;

	cm = client->clientmgr;
	lwb.base = NULL;

	ns_lwdclient_log(50, "generating gabn reply for client %p", client);

	/*
	 * We must make certain the client->find is not still active.
	 * If it is either the v4 or v6 answer, just set it to NULL and
	 * let the cleanup code destroy it.  Otherwise, destroy it now.
	 */
	if (client->find == client->v4find || client->find == client->v6find)
		client->find = NULL;
	else
		if (client->find != NULL)
			dns_adb_destroyfind(&client->find);

	/*
	 * perhaps there are some here?
	 */
	if (NEED_V6(client) && client->v4find != NULL)
		client->v6find = client->v4find;

	/*
	 * Run through the finds we have and wire them up to the gabn
	 * structure.
	 */
	LWRES_LIST_INIT(client->gabn.addrs);
	if (client->v4find != NULL)
		setup_addresses(client, client->v4find, DNS_ADBFIND_INET);
	if (client->v6find != NULL)
		setup_addresses(client, client->v6find, DNS_ADBFIND_INET6);

	/*
	 * If there are no addresses, try the next element in the search
	 * path, if there are any more.  Otherwise, fall through into
	 * the error handling code below.
	 */
	if (client->gabn.naddrs == 0) {
		do {
			result = ns_lwsearchctx_next(&client->searchctx);
			if (result == ISC_R_SUCCESS) {
				cleanup_gabn(client);
				result = start_find(client);
				if (result == ISC_R_SUCCESS)
					return;
			}
		} while (result == ISC_R_SUCCESS);
	}

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

	/*
	 * If there are no addresses, return failure.
	 */
	if (client->gabn.naddrs != 0)
		client->pkt.result = LWRES_R_SUCCESS;
	else
		client->pkt.result = LWRES_R_NOTFOUND;

	sort_addresses(client);

	lwres = lwres_gabnresponse_render(cm->lwctx, &client->gabn,
					  &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);

	/*
	 * All done!
	 */
	cleanup_gabn(client);

	return;

 out:
	cleanup_gabn(client);

	if (lwb.base != NULL)
		lwres_context_freemem(client->clientmgr->lwctx,
				      lwb.base, lwb.length);

	ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}

/*
 * Take the current real name, move it to an alias slot (if any are
 * open) then put this new name in as the real name for the target.
 *
 * Return success if it can be rendered, otherwise failure.  Note that
 * not having enough alias slots open is NOT a failure.
 */
static isc_result_t
add_alias(ns_lwdclient_t *client) {
	isc_buffer_t b;
	isc_result_t result;
	isc_uint16_t naliases;

	b = client->recv_buffer;

	/*
	 * Render the new name to the buffer.
	 */
	result = dns_name_totext(dns_fixedname_name(&client->target_name),
				 ISC_TRUE, &client->recv_buffer);
	if (result != ISC_R_SUCCESS)
		return (result);

	/*
	 * Are there any open slots?
	 */
	naliases = client->gabn.naliases;
	if (naliases < LWRES_MAX_ALIASES) {
		client->gabn.aliases[naliases] = client->gabn.realname;
		client->gabn.aliaslen[naliases] = client->gabn.realnamelen;
		client->gabn.naliases++;
	}

	/*
	 * 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 isc_result_t
store_realname(ns_lwdclient_t *client) {
	isc_buffer_t b;
	isc_result_t result;
	dns_name_t *tname;

	b = client->recv_buffer;

	tname = dns_fixedname_name(&client->target_name);
	result = ns_lwsearchctx_current(&client->searchctx, tname);
	if (result != ISC_R_SUCCESS)
		return (result);

	/*
	 * Render the new name to the buffer.
	 */
	result = dns_name_totext(tname, ISC_TRUE, &client->recv_buffer);
	if (result != ISC_R_SUCCESS)
		return (result);