query.c revision 64a840af4969584d44d69e69b11f5da925981b43
/*
* Copyright (C) 1999 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.
*/
#include <config.h>
#include <isc/assertions.h>
#include <isc/buffer.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/result.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/event.h>
#include <dns/a6.h>
#include <dns/db.h>
#include <dns/dbtable.h>
#include <dns/dispatch.h>
#include <dns/events.h>
#include <dns/fixedname.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/resolver.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <dns/zt.h>
#include <named/client.h>
#include <named/globals.h>
#include <named/query.h>
#include <named/xfrout.h>
#include "../../isc/util.h" /* XXX */
#define PARTIALANSWER(c) (((c)->query.attributes & \
NS_QUERYATTR_PARTIALANSWER) != 0)
#define USECACHE(c) (((c)->query.attributes & \
NS_QUERYATTR_CACHEOK) != 0)
#define RECURSIONOK(c) (((c)->query.attributes & \
NS_QUERYATTR_RECURSIONOK) != 0)
#define RECURSING(c) (((c)->query.attributes & \
NS_QUERYATTR_RECURSING) != 0)
static isc_result_t
query_simplefind(void *arg, dns_name_t *name, dns_rdatatype_t type,
dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset);
static inline void
query_adda6rrset(void *arg, dns_name_t *name, dns_rdataset_t *rdataset,
dns_rdataset_t *sigrdataset);
static void
query_find(ns_client_t *client, dns_fetchevent_t *event);
static inline void
query_maybeputqname(ns_client_t *client) {
if (client->query.restarts > 0) {
/*
* client->query.qname was dynamically allocated.
*/
dns_message_puttempname(client->message,
&client->query.qname);
client->query.qname = NULL;
}
}
static inline void
query_reset(ns_client_t *client, isc_boolean_t everything) {
isc_buffer_t *dbuf, *dbuf_next;
ns_dbversion_t *dbversion, *dbversion_next;
unsigned int i;
/*
* Reset the query state of a client to its default state.
*/
/*
* Cancel the fetch if it's running.
*/
if (client->query.fetch != NULL) {
dns_resolver_cancelfetch(client->view->resolver,
client->query.fetch);
client->query.fetch = NULL;
}
/*
* Cleanup any active versions.
*/
for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
dbversion != NULL;
dbversion = dbversion_next) {
dbversion_next = ISC_LIST_NEXT(dbversion, link);
dns_db_closeversion(dbversion->db, &dbversion->version,
ISC_FALSE);
dns_db_detach(&dbversion->db);
ISC_LIST_APPEND(client->query.freeversions, dbversion, link);
}
ISC_LIST_INIT(client->query.activeversions);
/*
* Clean up free versions.
*/
for (dbversion = ISC_LIST_HEAD(client->query.freeversions), i = 0;
dbversion != NULL;
dbversion = dbversion_next, i++) {
dbversion_next = ISC_LIST_NEXT(dbversion, link);
/*
* If we're not freeing everything, we keep the first three
* dbversions structures around.
*/
if (i > 3 || everything) {
ISC_LIST_UNLINK(client->query.freeversions, dbversion,
link);
isc_mem_put(client->mctx, dbversion,
sizeof *dbversion);
}
}
for (dbuf = ISC_LIST_HEAD(client->query.namebufs);
dbuf != NULL;
dbuf = dbuf_next) {
dbuf_next = ISC_LIST_NEXT(dbuf, link);
if (dbuf_next != NULL || everything) {
ISC_LIST_UNLINK(client->query.namebufs, dbuf, link);
isc_buffer_free(&dbuf);
}
}
query_maybeputqname(client);
client->query.attributes = (NS_QUERYATTR_RECURSIONOK|
NS_QUERYATTR_CACHEOK);
client->query.restarts = 0;
client->query.origqname = NULL;
client->query.qname = NULL;
client->query.qrdataset = NULL;
client->query.dboptions = 0;
client->query.gluedb = NULL;
}
static void
query_next(ns_client_t *client, isc_result_t result) {
(void)result;
query_reset(client, ISC_FALSE);
}
void
ns_query_free(ns_client_t *client) {
query_reset(client, ISC_TRUE);
}
static inline isc_result_t
query_newnamebuf(ns_client_t *client) {
isc_buffer_t *dbuf;
isc_result_t result;
/*
* Allocate a name buffer.
*/
dbuf = NULL;
result = isc_buffer_allocate(client->mctx, &dbuf, 1024,
ISC_BUFFERTYPE_BINARY);
if (result != ISC_R_SUCCESS)
return (result);
ISC_LIST_APPEND(client->query.namebufs, dbuf, link);
return (ISC_R_SUCCESS);
}
static inline isc_buffer_t *
query_getnamebuf(ns_client_t *client) {
isc_buffer_t *dbuf;
isc_result_t result;
isc_region_t r;
/*
* Return a name buffer with space for a maximal name, allocating
* a new one if necessary.
*/
if (ISC_LIST_EMPTY(client->query.namebufs)) {
result = query_newnamebuf(client);
if (result != ISC_R_SUCCESS)
return (NULL);
}
dbuf = ISC_LIST_TAIL(client->query.namebufs);
INSIST(dbuf != NULL);
isc_buffer_available(dbuf, &r);
if (r.length < 255) {
result = query_newnamebuf(client);
if (result != ISC_R_SUCCESS)
return (NULL);
dbuf = ISC_LIST_TAIL(client->query.namebufs);
isc_buffer_available(dbuf, &r);
INSIST(r.length >= 255);
}
return (dbuf);
}
static inline void
query_keepname(ns_client_t *client, dns_name_t *name, isc_buffer_t *dbuf) {
isc_region_t r;
/*
* 'name' is using space in 'dbuf', but 'dbuf' has not yet been
* adjusted to take account of that. We do the adjustment.
*/
REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) != 0);
dns_name_toregion(name, &r);
isc_buffer_add(dbuf, r.length);
dns_name_setbuffer(name, NULL);
client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
}
static inline void
query_releasename(ns_client_t *client, dns_name_t **namep) {
dns_name_t *name = *namep;
/*
* 'name' is no longer needed. Return it to our pool of temporary
* names. If it is using a name buffer, relinquish its exclusive
* rights on the buffer.
*/
if (dns_name_hasbuffer(name)) {
INSIST((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED)
!= 0);
client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
}
dns_message_puttempname(client->message, namep);
}
static inline dns_name_t *
query_newname(ns_client_t *client, isc_buffer_t *dbuf,
isc_buffer_t *nbuf)
{
dns_name_t *name;
isc_region_t r;
isc_result_t result;
REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) == 0);
name = NULL;
result = dns_message_gettempname(client->message, &name);
if (result != ISC_R_SUCCESS)
return (NULL);
isc_buffer_available(dbuf, &r);
isc_buffer_init(nbuf, r.base, r.length, ISC_BUFFERTYPE_BINARY);
dns_name_init(name, NULL);
dns_name_setbuffer(name, nbuf);
client->query.attributes |= NS_QUERYATTR_NAMEBUFUSED;
return (name);
}
static inline dns_rdataset_t *
query_newrdataset(ns_client_t *client) {
dns_rdataset_t *rdataset;
isc_result_t result;
rdataset = NULL;
result = dns_message_gettemprdataset(client->message, &rdataset);
if (result != ISC_R_SUCCESS)
return (NULL);
dns_rdataset_init(rdataset);
return (rdataset);
}
static inline void
query_putrdataset(ns_client_t *client, dns_rdataset_t **rdatasetp) {
dns_rdataset_t *rdataset = *rdatasetp;
if (rdataset != NULL) {
if (rdataset->methods != NULL)
dns_rdataset_disassociate(rdataset);
dns_message_puttemprdataset(client->message, rdatasetp);
}
}
static inline isc_result_t
query_newdbversion(ns_client_t *client, unsigned int n) {
unsigned int i;
ns_dbversion_t *dbversion;
for (i = 0; i < n; i++) {
dbversion = isc_mem_get(client->mctx, sizeof *dbversion);
if (dbversion != NULL) {
dbversion->db = NULL;
dbversion->version = NULL;
ISC_LIST_APPEND(client->query.freeversions, dbversion,
link);
} else {
/*
* We only return ISC_R_NOMEMORY if we couldn't
* allocate anything.
*/
if (i == 0)
return (ISC_R_NOMEMORY);
else
return (ISC_R_SUCCESS);
}
}
return (ISC_R_SUCCESS);
}
static inline ns_dbversion_t *
query_getdbversion(ns_client_t *client) {
isc_result_t result;
ns_dbversion_t *dbversion;
if (ISC_LIST_EMPTY(client->query.freeversions)) {
result = query_newdbversion(client, 1);
if (result != ISC_R_SUCCESS)
return (NULL);
}
dbversion = ISC_LIST_HEAD(client->query.freeversions);
INSIST(dbversion != NULL);
ISC_LIST_UNLINK(client->query.freeversions, dbversion, link);
return (dbversion);
}
isc_result_t
ns_query_init(ns_client_t *client) {
isc_result_t result;
ISC_LIST_INIT(client->query.namebufs);
ISC_LIST_INIT(client->query.activeversions);
ISC_LIST_INIT(client->query.freeversions);
client->query.restarts = 0;
client->query.qname = NULL;
client->query.fetch = NULL;
query_reset(client, ISC_FALSE);
result = query_newdbversion(client, 3);
if (result != ISC_R_SUCCESS)
return (result);
dns_a6_init(&client->query.a6ctx, query_simplefind, query_adda6rrset,
NULL, NULL, client);
return (query_newnamebuf(client));
}
static inline dns_dbversion_t *
query_findversion(ns_client_t *client, dns_db_t *db) {
ns_dbversion_t *dbversion;
/*
* We may already have done a query related to this
* database. If so, we must be sure to make subsequent
* queries from the same version.
*/
for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
dbversion != NULL;
dbversion = ISC_LIST_NEXT(dbversion, link)) {
if (dbversion->db == db)
break;
}
if (dbversion == NULL) {
/*
* This is a new zone for this query. Add it to
* the active list.
*/
dbversion = query_getdbversion(client);
if (dbversion == NULL)
return (NULL);
dns_db_attach(db, &dbversion->db);
dns_db_currentversion(db, &dbversion->version);
ISC_LIST_APPEND(client->query.activeversions,
dbversion, link);
}
return (dbversion->version);
}
static isc_result_t
query_simplefind(void *arg, dns_name_t *name, dns_rdatatype_t type,
dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
ns_client_t *client = arg;
isc_result_t result;
dns_fixedname_t foundname;
dns_db_t *db;
dns_dbversion_t *version;
unsigned int dboptions;
isc_boolean_t is_zone;
dns_rdataset_t zrdataset, zsigrdataset;
dns_zone_t *zone;
REQUIRE(NS_CLIENT_VALID(client));
dns_rdataset_init(&zrdataset);
dns_rdataset_init(&zsigrdataset);
/*
* Find a database to answer the query.
*/
zone = NULL;
db = NULL;
result = dns_zt_find(client->view->zonetable, name, NULL, &zone);
if (result == DNS_R_SUCCESS || result == DNS_R_PARTIALMATCH)
result = dns_zone_getdb(zone, &db);
if (result == ISC_R_NOTFOUND && USECACHE(client))
dns_db_attach(client->view->cachedb, &db);
else if (result != DNS_R_SUCCESS)
goto cleanup;
/*
* Get the current version of this database.
*/
version = NULL;
is_zone = dns_db_iszone(db);
if (is_zone) {
version = query_findversion(client, db);
if (version == NULL)
goto cleanup;
}
db_find:
/*
* Now look for an answer in the database.
*/
dns_fixedname_init(&foundname);
dboptions = client->query.dboptions;
if (db == client->query.gluedb)
dboptions |= DNS_DBFIND_GLUEOK;
result = dns_db_find(db, name, version, type, dboptions,
client->requesttime, NULL,
dns_fixedname_name(&foundname),
rdataset, sigrdataset);
if (result == DNS_R_DELEGATION ||
result == DNS_R_NOTFOUND ||
result == DNS_R_NXGLUE) {
if (rdataset->methods != NULL)
dns_rdataset_disassociate(rdataset);
if (sigrdataset->methods != NULL)
dns_rdataset_disassociate(sigrdataset);
if (is_zone) {
if (USECACHE(client)) {
/*
* Either the answer is in the cache, or we
* don't know it.
*/
is_zone = ISC_FALSE;
version = NULL;
dns_db_detach(&db);
dns_db_attach(client->view->cachedb, &db);
goto db_find;
}
} else {
/*
* We don't have the data in the cache. If we've got
* glue from the zone, use it.
*/
if (zrdataset.methods != NULL) {
dns_rdataset_clone(&zrdataset, rdataset);
if (zsigrdataset.methods != NULL)
dns_rdataset_clone(&zsigrdataset,
sigrdataset);
result = ISC_R_SUCCESS;
goto cleanup;
}
}
/*
* We don't know the answer.
*/
result = DNS_R_NOTFOUND;
} else if (result == DNS_R_GLUE) {
if (USECACHE(client)) {
/*
* We found an answer, but the cache may be better.
* Remember what we've got and go look in the cache.
*/
is_zone = ISC_FALSE;
version = NULL;
dns_rdataset_clone(rdataset, &zrdataset);
dns_rdataset_disassociate(rdataset);
if (sigrdataset->methods != NULL) {
dns_rdataset_clone(sigrdataset, &zsigrdataset);
dns_rdataset_disassociate(sigrdataset);
}
dns_db_detach(&db);
dns_db_attach(client->view->cachedb, &db);
goto db_find;
}
/*
* Otherwise, the glue is the best answer.
*/
result = ISC_R_SUCCESS;
} else if (result != ISC_R_SUCCESS)
result = DNS_R_NOTFOUND;
cleanup:
if (zrdataset.methods != NULL) {
dns_rdataset_disassociate(&zrdataset);
if (zsigrdataset.methods != NULL)
dns_rdataset_disassociate(&zsigrdataset);
}
if (db != NULL)
dns_db_detach(&db);
if (zone != NULL)
dns_zone_detach(&zone);
return (result);
}
static inline isc_boolean_t
query_isduplicate(ns_client_t *client, dns_name_t *name,
dns_rdatatype_t type, dns_name_t **mnamep)
{
dns_section_t section;
dns_name_t *mname = NULL;
dns_result_t result;
for (section = DNS_SECTION_ANSWER;
section <= DNS_SECTION_ADDITIONAL;
section++) {
result = dns_message_findname(client->message, section,
name, type, 0, &mname, NULL);
if (result == ISC_R_SUCCESS) {
/*
* We've already got this RRset in the response.
*/
return (ISC_TRUE);
} else if (result == DNS_R_NXRDATASET) {
/*
* The name exists, but the rdataset does not.
*/
if (section == DNS_SECTION_ADDITIONAL)
break;
} else
RUNTIME_CHECK(result == DNS_R_NXDOMAIN);
mname = NULL;
}
/*
* If the dns_name_t we're lookup up is already in the message,
* we don't want to trigger the caller's name replacement logic.
*/
if (name == mname)
mname = NULL;
*mnamep = mname;
return (ISC_FALSE);
}
static isc_result_t
query_addadditional(void *arg, dns_name_t *name, dns_rdatatype_t type) {
ns_client_t *client = arg;
isc_result_t result, eresult;
dns_dbnode_t *node, *znode;
dns_db_t *db, *zdb;
dns_name_t *fname, *zfname, *mname;
dns_rdataset_t *rdataset, *sigrdataset, *a6rdataset;
dns_rdataset_t *zrdataset, *zsigrdataset;
isc_buffer_t *dbuf;
isc_buffer_t b;
dns_dbversion_t *version, *zversion;
unsigned int dboptions;
isc_boolean_t is_zone, added_something, need_addname;
dns_zone_t *zone;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(type != dns_rdatatype_any);
/* XXXRTH Other requirements. */
/*
* Initialization.
*/
eresult = ISC_R_SUCCESS;
fname = NULL;
zfname = NULL;
rdataset = NULL;
zrdataset = NULL;
sigrdataset = NULL;
zsigrdataset = NULL;
a6rdataset = NULL;
db = NULL;
zdb = NULL;
version = NULL;
zversion = NULL;
node = NULL;
znode = NULL;
added_something = ISC_FALSE;
need_addname = ISC_FALSE;
zone = NULL;
/*
* Find a database to answer the query.
*/
result = dns_zt_find(client->view->zonetable, name, NULL, &zone);
if (result == DNS_R_SUCCESS || result == DNS_R_PARTIALMATCH)
result = dns_zone_getdb(zone, &db);
if (result == ISC_R_NOTFOUND && USECACHE(client))
dns_db_attach(client->view->cachedb, &db);
else if (result != DNS_R_SUCCESS)
goto cleanup;
/*
* Get the current version of this database.
*/
is_zone = dns_db_iszone(db);
if (is_zone) {
version = query_findversion(client, db);
if (version == NULL)
goto cleanup;
}
db_find:
/*
* Get some resources...
*/
dbuf = query_getnamebuf(client);
if (dbuf == NULL)
goto cleanup;
fname = query_newname(client, dbuf, &b);
rdataset = query_newrdataset(client);
sigrdataset = query_newrdataset(client);
if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
goto cleanup;
/*
* Now look for an answer in the database.
*/
node = NULL;
dboptions = client->query.dboptions;
if (db == client->query.gluedb)
dboptions |= DNS_DBFIND_GLUEOK;
result = dns_db_find(db, name, version, type, dboptions,
client->requesttime, &node, fname, rdataset,
sigrdataset);
if (result == DNS_R_DELEGATION || result == DNS_R_NOTFOUND) {
if (is_zone) {
if (USECACHE(client)) {
/*
* Either the answer is in the cache, or we
* don't know it. Go look in the cache.
*/
query_releasename(client, &fname);
is_zone = ISC_FALSE;
version = NULL;
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
dns_db_detachnode(db, &node);
dns_db_detach(&db);
dns_db_attach(client->view->cachedb, &db);
goto db_find;
} else {
/*
* We don't know the answer.
*/
goto cleanup;
}
} else {
/*
* We don't have the data in the cache. If we've
* got glue from the zone, use it.
*/
if (zdb != NULL) {
query_releasename(client, &fname);
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (node != NULL)
dns_db_detachnode(db, &node);
dns_db_detach(&db);
db = zdb;
zdb = NULL;
fname = zfname;
dbuf = NULL;
node = znode;
version = zversion;
rdataset = zrdataset;
sigrdataset = zsigrdataset;
} else {
/*
* We don't know the answer.
*/
goto cleanup;
}
}
} else if (result == DNS_R_GLUE || result == DNS_R_NXGLUE) {
if (USECACHE(client)) {
/*
* We found an answer, but the cache may be
* better. Remember what we've got and go look in
* the cache.
*/
query_keepname(client, fname, dbuf);
zfname = fname;
zdb = db;
zversion = version;
znode = node;
zrdataset = rdataset;
zsigrdataset = sigrdataset;
version = NULL;
db = NULL;
dns_db_attach(client->view->cachedb, &db);
is_zone = ISC_FALSE;
goto db_find;
}
} else if (result != DNS_R_SUCCESS)
goto cleanup;
if (dbuf != NULL)
query_keepname(client, fname, dbuf);
mname = NULL;
if (rdataset->methods != NULL &&
!query_isduplicate(client, fname, type, &mname)) {
if (mname != NULL) {
query_releasename(client, &fname);
fname = mname;
} else
need_addname = ISC_TRUE;
ISC_LIST_APPEND(fname->list, rdataset, link);
rdataset = NULL;
added_something = ISC_TRUE;
/*
* Note: we only add SIGs if we've added the type they cover,
* so we do not need to check if the SIG rdataset is already
* in the response.
*/
if (sigrdataset->methods != NULL) {
ISC_LIST_APPEND(fname->list, sigrdataset, link);
sigrdataset = NULL;
}
}
if (type == dns_rdatatype_a) {
/*
* We treat type A additional section processing as if it
* were "any address type" additional section processing.
*
* We now go looking for A6 and AAAA records, along with
* their signatures.
*
* XXXRTH This code could be more efficient.
*/
if (rdataset != NULL) {
if (rdataset->methods != NULL)
dns_rdataset_disassociate(rdataset);
} else {
rdataset = query_newrdataset(client);
if (rdataset == NULL)
goto addname;
}
if (sigrdataset != NULL) {
if (sigrdataset->methods != NULL)
dns_rdataset_disassociate(sigrdataset);
} else {
sigrdataset = query_newrdataset(client);
if (sigrdataset == NULL)
goto addname;
}
result = dns_db_findrdataset(db, node, version,
dns_rdatatype_a6, 0,
client->requesttime, rdataset,
sigrdataset);
if (zdb != NULL && result == ISC_R_NOTFOUND) {
/*
* The cache doesn't have an A6, but we may have
* one in the zone's glue.
*/
result = dns_db_findrdataset(zdb, znode, zversion,
dns_rdatatype_a6, 0,
client->requesttime,
rdataset,
sigrdataset);
}
if (result == ISC_R_SUCCESS) {
mname = NULL;
if (!query_isduplicate(client, fname,
dns_rdatatype_a6, &mname)) {
if (mname != NULL) {
query_releasename(client, &fname);
fname = mname;
} else
need_addname = ISC_TRUE;
a6rdataset = rdataset;
ISC_LIST_APPEND(fname->list, rdataset, link);
added_something = ISC_TRUE;
if (sigrdataset->methods != NULL) {
ISC_LIST_APPEND(fname->list,
sigrdataset, link);
sigrdataset =
query_newrdataset(client);
}
rdataset = query_newrdataset(client);
if (rdataset == NULL || sigrdataset == NULL)
goto addname;
} else
dns_rdataset_disassociate(rdataset);
}
result = dns_db_findrdataset(db, node, version,
dns_rdatatype_aaaa, 0,
client->requesttime, rdataset,
sigrdataset);
if (zdb != NULL && result == ISC_R_NOTFOUND) {
/*
* The cache doesn't have an AAAA, but we may have
* one in the zone's glue.
*/
result = dns_db_findrdataset(zdb, znode, zversion,
dns_rdatatype_aaaa, 0,
client->requesttime,
rdataset,
sigrdataset);
}
if (result == ISC_R_SUCCESS) {
mname = NULL;
if (!query_isduplicate(client, fname,
dns_rdatatype_aaaa, &mname)) {
if (mname != NULL) {
query_releasename(client, &fname);
fname = mname;
} else
need_addname = ISC_TRUE;
ISC_LIST_APPEND(fname->list, rdataset, link);
added_something = ISC_TRUE;
if (sigrdataset->methods != NULL) {
ISC_LIST_APPEND(fname->list,
sigrdataset, link);
sigrdataset = NULL;
}
rdataset = NULL;
}
}
}
addname:
/*
* If we haven't added anything, then we're done.
*/
if (!added_something)
goto cleanup;
/*
* We may have added our rdatasets to an existing name, if so, then
* need_addname will be ISC_FALSE. Whether we used an existing name
* or a new one, we must set fname to NULL to prevent cleanup.
*/
if (need_addname)
dns_message_addname(client->message, fname,
DNS_SECTION_ADDITIONAL);
fname = NULL;
/*
* In a few cases, we want to add additional data for additional
* data. It's simpler to just deal with special cases here than
* to try to create a general purpose mechanism and allow the
* rdata implementations to do it themselves.
*
* This involves recursion, but the depth is limited. The
* most complex case is adding a SRV rdataset, which involves
* recursing to add address records, which in turn can cause
* recursion to add KEYs.
*/
if (type == dns_rdatatype_a || type == dns_rdatatype_aaaa) {
/*
* RFC 2535 section 3.5 says that when A or AAAA records are
* retrieved as additional data, any KEY RRs for the owner name
* should be added to the additional data section. Note: we
* do NOT include A6 in the list of types with such treatment
* in additional data because we'd have to do it for each A6
* in the A6 chain.
*
* XXXRTH We should lower the priority here. Alternatively,
* we could raise the priority of glue records.
*/
eresult = query_addadditional(client, name, dns_rdatatype_key);
} else if (type == dns_rdatatype_srv) {
/*
* If we're adding SRV records to the additional data
* section, it's helpful if we add the SRV additional data
* as well.
*/
eresult = dns_rdataset_additionaldata(rdataset,
query_addadditional,
client);
}
/*
* If we added an A6 rdataset, we should also add everything we
* know about the A6 chains. We wait until now to do this so that
* they'll come after any additional data added above.
*/
if (a6rdataset != NULL) {
dns_a6_reset(&client->query.a6ctx);
dns_a6_foreach(&client->query.a6ctx, a6rdataset);
}
cleanup:
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (fname != NULL)
query_releasename(client, &fname);
if (node != NULL)
dns_db_detachnode(db, &node);
if (db != NULL)
dns_db_detach(&db);
if (zone != NULL)
dns_zone_detach(&zone);
if (zdb != NULL) {
if (zfname != NULL)
query_releasename(client, &zfname);
query_putrdataset(client, &zrdataset);
query_putrdataset(client, &zsigrdataset);
if (znode != NULL)
dns_db_detachnode(zdb, &znode);
dns_db_detach(&zdb);
}
return (eresult);
}
static void
query_adda6rrset(void *arg, dns_name_t *name, dns_rdataset_t *rdataset,
dns_rdataset_t *sigrdataset)
{
ns_client_t *client = arg;
dns_rdataset_t *crdataset, *csigrdataset;
isc_buffer_t b, *dbuf;
dns_name_t *fname, *mname;
/*
* Add an rrset to the additional data section.
*/
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(rdataset->type == dns_rdatatype_a6);
/*
* Get some resources...
*/
fname = NULL;
crdataset = NULL;
csigrdataset = NULL;
dbuf = query_getnamebuf(client);
if (dbuf == NULL)
goto cleanup;
fname = query_newname(client, dbuf, &b);
crdataset = query_newrdataset(client);
csigrdataset = query_newrdataset(client);
if (fname == NULL || crdataset == NULL || csigrdataset == NULL)
goto cleanup;
if (dns_name_concatenate(name, NULL, fname, NULL) != ISC_R_SUCCESS)
goto cleanup;
dns_rdataset_clone(rdataset, crdataset);
if (sigrdataset->methods != NULL)
dns_rdataset_clone(sigrdataset, csigrdataset);
mname = NULL;
if (query_isduplicate(client, fname, crdataset->type, &mname))
goto cleanup;
if (mname != NULL) {
query_releasename(client, &fname);
fname = mname;
} else {
query_keepname(client, fname, dbuf);
dns_message_addname(client->message, fname,
DNS_SECTION_ADDITIONAL);
}
ISC_LIST_APPEND(fname->list, crdataset, link);
crdataset = NULL;
/*
* Note: we only add SIGs if we've added the type they cover, so
* we do not need to check if the SIG rdataset is already in the
* response.
*/
if (csigrdataset->methods != NULL) {
ISC_LIST_APPEND(fname->list, csigrdataset, link);
csigrdataset = NULL;
}
fname = NULL;
/*
* In spite of RFC 2535 section 3.5, we don't currently try to add
* KEY RRs for the A6 records. It's just too much work.
*/
cleanup:
query_putrdataset(client, &crdataset);
query_putrdataset(client, &csigrdataset);
if (fname != NULL)
query_releasename(client, &fname);
}
static inline void
query_addrdataset(ns_client_t *client, dns_name_t *fname,
dns_rdataset_t *rdataset)
{
dns_rdatatype_t type = rdataset->type;
ISC_LIST_APPEND(fname->list, rdataset, link);
/*
* Add additional data.
*
* We don't care if dns_a6_foreach or dns_rdataset_additionaldata()
* fail.
*/
if (type == dns_rdatatype_a6) {
dns_a6_reset(&client->query.a6ctx);
(void)dns_a6_foreach(&client->query.a6ctx, rdataset);
} else
(void)dns_rdataset_additionaldata(rdataset,
query_addadditional, client);
/*
* RFC 2535 section 3.5 says that when NS, SOA, A, or AAAA records
* are retrieved, any KEY RRs for the owner name should be added
* to the additional data section. We treat A6 records the same way.
*
* We don't care if query_additional() fails.
*/
if (type == dns_rdatatype_ns || type == dns_rdatatype_soa ||
type == dns_rdatatype_a || type == dns_rdatatype_aaaa ||
type == dns_rdatatype_a6) {
/*
* XXXRTH We should lower the priority here. Alternatively,
* we could raise the priority of glue records.
*/
(void)query_addadditional(client, fname, dns_rdatatype_key);
}
}
#define ANSWERED(rds) (((rds)->attributes & DNS_RDATASETATTR_ANSWERED) != 0)
static void
query_addrrset(ns_client_t *client, dns_name_t **namep,
dns_rdataset_t **rdatasetp, dns_rdataset_t **sigrdatasetp,
isc_buffer_t *dbuf, dns_section_t section)
{
dns_name_t *name, *mname;
dns_rdataset_t *rdataset, *mrdataset, *sigrdataset;
isc_result_t result;
name = *namep;
rdataset = *rdatasetp;
if (sigrdatasetp != NULL)
sigrdataset = *sigrdatasetp;
else
sigrdataset = NULL;
mname = NULL;
mrdataset = NULL;
result = dns_message_findname(client->message, section,
name, rdataset->type, rdataset->covers,
&mname, &mrdataset);
if (result == ISC_R_SUCCESS) {
/*
* We've already got an RRset of the given name and type.
* There's nothing else to do;
*/
return;
} else if (result == DNS_R_NXDOMAIN) {
/*
* The name doesn't exist.
*/
if (dbuf != NULL)
query_keepname(client, name, dbuf);
dns_message_addname(client->message, name, section);
*namep = NULL;
mname = name;
} else
RUNTIME_CHECK(result == DNS_R_NXRDATASET);
/*
* Note: we only add SIGs if we've added the type they cover, so
* we do not need to check if the SIG rdataset is already in the
* response.
*/
query_addrdataset(client, mname, rdataset);
*rdatasetp = NULL;
if (sigrdataset != NULL && sigrdataset->methods != NULL) {
/*
* We have a signature. Add it to the response.
*/
ISC_LIST_APPEND(mname->list, sigrdataset, link);
*sigrdatasetp = NULL;
}
}
static inline isc_result_t
query_addsoa(ns_client_t *client, dns_db_t *db) {
dns_name_t *name, *fname;
dns_dbnode_t *node;
isc_result_t result, eresult;
dns_fixedname_t foundname;
dns_rdataset_t *rdataset, *sigrdataset;
/*
* Initialization.
*/
eresult = ISC_R_SUCCESS;
name = NULL;
rdataset = NULL;
node = NULL;
dns_fixedname_init(&foundname);
fname = dns_fixedname_name(&foundname);
/*
* Get resources and make 'name' be the database origin.
*/
result = dns_message_gettempname(client->message, &name);
if (result != ISC_R_SUCCESS)
return (result);
dns_name_init(name, NULL);
dns_name_clone(dns_db_origin(db), name);
rdataset = query_newrdataset(client);
sigrdataset = query_newrdataset(client);
if (rdataset == NULL || sigrdataset == NULL) {
eresult = DNS_R_SERVFAIL;
goto cleanup;
}
/*
* Find the SOA.
*/
result = dns_db_find(db, name, NULL, dns_rdatatype_soa, 0, 0, &node,
fname, rdataset, sigrdataset);
if (result != ISC_R_SUCCESS) {
/*
* This is bad. We tried to get the SOA RR at the zone top
* and it didn't work!
*/
eresult = DNS_R_SERVFAIL;
} else {
query_addrrset(client, &name, &rdataset, &sigrdataset, NULL,
DNS_SECTION_AUTHORITY);
}
cleanup:
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (name != NULL)
query_releasename(client, &name);
if (node != NULL)
dns_db_detachnode(db, &node);
return (eresult);
}
static inline isc_result_t
query_addns(ns_client_t *client, dns_db_t *db) {
dns_name_t *name, *fname;
dns_dbnode_t *node;
isc_result_t result, eresult;
dns_fixedname_t foundname;
dns_rdataset_t *rdataset, *sigrdataset;
/*
* Initialization.
*/
eresult = ISC_R_SUCCESS;
name = NULL;
rdataset = NULL;
node = NULL;
dns_fixedname_init(&foundname);
fname = dns_fixedname_name(&foundname);
/*
* Get resources and make 'name' be the database origin.
*/
result = dns_message_gettempname(client->message, &name);
if (result != ISC_R_SUCCESS)
return (result);
dns_name_init(name, NULL);
dns_name_clone(dns_db_origin(db), name);
rdataset = query_newrdataset(client);
sigrdataset = query_newrdataset(client);
if (rdataset == NULL || sigrdataset == NULL) {
eresult = DNS_R_SERVFAIL;
goto cleanup;
}
/*
* Find the NS rdataset.
*/
result = dns_db_find(db, name, NULL, dns_rdatatype_ns, 0, 0, &node,
fname, rdataset, sigrdataset);
if (result != ISC_R_SUCCESS) {
/*
* This is bad. We tried to get the NS rdataset at the zone
* top and it didn't work!
*/
eresult = DNS_R_SERVFAIL;
} else {
query_addrrset(client, &name, &rdataset, &sigrdataset, NULL,
DNS_SECTION_AUTHORITY);
}
cleanup:
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (name != NULL)
query_releasename(client, &name);
if (node != NULL)
dns_db_detachnode(db, &node);
return (eresult);
}
static inline isc_result_t
query_addcname(ns_client_t *client, dns_name_t *qname, dns_name_t *tname,
dns_ttl_t ttl, dns_name_t **anamep)
{
dns_rdataset_t *rdataset;
dns_rdatalist_t *rdatalist;
dns_rdata_t *rdata;
isc_result_t result;
isc_region_t r;
/*
* We assume the name data referred to by qname and tname won't
* go away.
*/
REQUIRE(anamep != NULL);
rdatalist = NULL;
result = dns_message_gettemprdatalist(client->message, &rdatalist);
if (result != ISC_R_SUCCESS)
return (result);
rdata = NULL;
result = dns_message_gettemprdata(client->message, &rdata);
if (result != ISC_R_SUCCESS)
return (result);
rdataset = NULL;
result = dns_message_gettemprdataset(client->message, &rdataset);
if (result != ISC_R_SUCCESS)
return (result);
dns_rdataset_init(rdataset);
dns_name_clone(qname, *anamep);
rdatalist->type = dns_rdatatype_cname;
rdatalist->covers = 0;
rdatalist->rdclass = client->message->rdclass;
rdatalist->ttl = ttl;
dns_name_toregion(tname, &r);
rdata->data = r.base;
rdata->length = r.length;
ISC_LIST_INIT(rdatalist->rdata);
ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
dns_rdatalist_tordataset(rdatalist, rdataset);
query_addrrset(client, anamep, &rdataset, NULL, NULL,
DNS_SECTION_ANSWER);
if (rdataset != NULL) {
if (dns_rdataset_isassociated(rdataset))
dns_rdataset_disassociate(rdataset);
dns_message_puttemprdataset(client->message, &rdataset);
}
return (ISC_R_SUCCESS);
}
static void
query_addbestns(ns_client_t *client) {
dns_db_t *db, *zdb;
dns_dbnode_t *node;
dns_name_t *fname, *zfname;
dns_rdataset_t *rdataset, *sigrdataset, *zrdataset, *zsigrdataset;
isc_boolean_t is_zone, use_zone;
isc_buffer_t *dbuf;
isc_result_t result;
dns_dbversion_t *version;
dns_zone_t *zone;
isc_buffer_t b;
fname = NULL;
zfname = NULL;
rdataset = NULL;
zrdataset = NULL;
sigrdataset = NULL;
zsigrdataset = NULL;
node = NULL;
db = NULL;
zdb = NULL;
version = NULL;
zone = NULL;
use_zone = ISC_FALSE;
/*
* Find the right database.
*/
result = dns_zt_find(client->view->zonetable, client->query.qname,
NULL, &zone);
if (result == DNS_R_SUCCESS || result == DNS_R_PARTIALMATCH)
result = dns_zone_getdb(zone, &db);
if (result == ISC_R_NOTFOUND) {
/*
* We're not directly authoritative for this query name, nor
* is it a subdomain of any zone for which we're
* authoritative.
*/
if (!USECACHE(client))
goto cleanup;
INSIST(client->view->cachedb != NULL);
dns_db_attach(client->view->cachedb, &db);
} else if (result != ISC_R_SUCCESS) {
/*
* Something is broken.
*/
goto cleanup;
}
is_zone = dns_db_iszone(db);
if (is_zone) {
version = query_findversion(client, db);
if (version == NULL)
goto cleanup;
} else
version = NULL;
db_find:
/*
* We'll need some resources...
*/
dbuf = query_getnamebuf(client);
if (dbuf == NULL)
goto cleanup;
fname = query_newname(client, dbuf, &b);
rdataset = query_newrdataset(client);
sigrdataset = query_newrdataset(client);
if (fname == NULL || rdataset == NULL || sigrdataset == NULL)
goto cleanup;
/*
* Now look for the zonecut.
*/
if (is_zone) {
result = dns_db_find(db, client->query.qname, version,
dns_rdatatype_ns, 0,
client->requesttime, &node, fname,
rdataset, sigrdataset);
if (result != DNS_R_DELEGATION)
goto cleanup;
if (USECACHE(client)) {
query_keepname(client, fname, dbuf);
zdb = db;
zfname = fname;
zrdataset = rdataset;
zsigrdataset = sigrdataset;
dns_db_detachnode(db, &node);
version = NULL;
db = NULL;
dns_db_attach(client->view->cachedb, &db);
is_zone = ISC_FALSE;
goto db_find;
}
} else {
result = dns_db_findzonecut(db, client->query.qname, 0,
client->requesttime, &node, fname,
rdataset, sigrdataset);
if (result == ISC_R_SUCCESS) {
if (zfname != NULL &&
!dns_name_issubdomain(fname, zfname)) {
/*
* We found a zonecut in the cache, but our
* zone delegation is better.
*/
use_zone = ISC_TRUE;
}
} else if (result == ISC_R_NOTFOUND && zfname != NULL) {
/*
* We didn't find anything in the cache, but we
* have a zone delegation, so use it.
*/
use_zone = ISC_TRUE;
} else
goto cleanup;
}
if (use_zone) {
query_releasename(client, &fname);
fname = zfname;
zfname = NULL;
/*
* We've already done query_keepname() on
* zfname, so we must set dbuf to NULL to
* prevent query_addrrset() from trying to
* call query_keepname() again.
*/
dbuf = NULL;
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
rdataset = zrdataset;
zrdataset = NULL;
sigrdataset = zsigrdataset;
zsigrdataset = NULL;
}
query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
DNS_SECTION_AUTHORITY);
cleanup:
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (fname != NULL)
query_releasename(client, &fname);
if (node != NULL)
dns_db_detachnode(db, &node);
if (db != NULL)
dns_db_detach(&db);
if (zone != NULL)
dns_zone_detach(&zone);
if (zdb != NULL) {
query_putrdataset(client, &zrdataset);
query_putrdataset(client, &zsigrdataset);
if (zfname != NULL)
query_releasename(client, &zfname);
dns_db_detach(&zdb);
}
}
static inline isc_result_t
query_checktype(dns_rdatatype_t type) {
/*
* XXXRTH OPT still needs to be added.
* Should get help with this from rdata.c
*/
switch (type) {
case dns_rdatatype_tkey:
return (DNS_R_NOTIMP);
case dns_rdatatype_tsig:
return (DNS_R_FORMERR);
case dns_rdatatype_ixfr:
case dns_rdatatype_axfr:
case dns_rdatatype_mailb:
case dns_rdatatype_maila:
return (DNS_R_REFUSED);
default:
break;
}
return (ISC_R_SUCCESS);
}
static void
query_resume(isc_task_t *task, isc_event_t *event) {
dns_fetchevent_t *devent = (dns_fetchevent_t *)event;
ns_client_t *client;
isc_boolean_t want_find;
/*
* Resume a query after recursion.
*/
REQUIRE(event->type == DNS_EVENT_FETCHDONE);
client = devent->arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
REQUIRE(RECURSING(client));
if (devent->fetch == client->query.fetch) {
/*
* This is the fetch we've been waiting for.
*/
client->query.fetch = NULL;
want_find = ISC_TRUE;
} else {
/*
* This is a fetch completion event for a cancelled fetch.
* Clean up and don't resume the find.
*/
if (devent->node != NULL)
dns_db_detachnode(devent->db, &devent->node);
if (devent->db != NULL)
dns_db_detach(&devent->db);
query_putrdataset(client, &devent->rdataset);
query_putrdataset(client, &devent->sigrdataset);
want_find = ISC_FALSE;
}
client->query.attributes &= ~NS_QUERYATTR_RECURSING;
dns_resolver_destroyfetch(client->view->resolver, &devent->fetch);
client->waiting--;
/*
* XXXRTH If this client is shutting down, or this transaction
* has timed out, do not resume the find.
*
* We should probably have a "unwait" function that
* decrements waiting and tells us whether we should continue,
* do nothing, or reset the client (resetting would cause the
* client to continue with shutdown if it was in shutdown
* mode).
*/
if (want_find)
query_find(client, devent);
}
static isc_result_t
query_recurse(ns_client_t *client, dns_rdatatype_t qtype, dns_name_t *qdomain,
dns_rdataset_t *nameservers)
{
isc_result_t result;
dns_rdataset_t *rdataset, *sigrdataset;
/*
* Invoke the resolver.
*/
REQUIRE(nameservers->type == dns_rdatatype_ns);
REQUIRE(client->query.fetch == NULL);
rdataset = query_newrdataset(client);
if (rdataset == NULL)
return (ISC_R_NOMEMORY);
sigrdataset = query_newrdataset(client);
if (rdataset == NULL) {
query_putrdataset(client, &rdataset);
return (ISC_R_NOMEMORY);
}
result = dns_resolver_createfetch(client->view->resolver,
client->query.qname,
qtype, qdomain, nameservers,
NULL, 0, client->task, query_resume,
client, rdataset, sigrdataset,
&client->query.fetch);
if (result == ISC_R_SUCCESS) {
/*
* Record that we're waiting for an event. A client which
* is shutting down will not be destroyed until all the
* events have been received.
*/
client->waiting++;
} else {
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
}
return (result);
}
#define MAX_RESTARTS 16
#define QUERY_ERROR(r) \
do { \
eresult = r; \
want_restart = ISC_FALSE; \
} while (0)
static void
query_find(ns_client_t *client, dns_fetchevent_t *event) {
dns_db_t *db, *zdb;
dns_dbnode_t *node;
dns_rdatatype_t qtype, type;
dns_name_t *fname, *zfname, *tname, *prefix;
dns_rdataset_t *rdataset, *trdataset;
dns_rdataset_t *sigrdataset, *zrdataset, *zsigrdataset;
dns_rdata_t rdata;
dns_rdatasetiter_t *rdsiter;
isc_boolean_t want_restart, authoritative, is_zone, clear_fname;
unsigned int qcount, n, nlabels, nbits;
dns_namereln_t namereln;
int order;
isc_buffer_t *dbuf;
isc_region_t r;
isc_buffer_t b;
isc_result_t result, eresult;
dns_fixedname_t fixed;
dns_dbversion_t *version;
dns_zone_t *zone;
/*
* One-time initialization.
*
* It's especially important to initialize anything that the cleanup
* code might cleanup.
*/
eresult = ISC_R_SUCCESS;
fname = NULL;
zfname = NULL;
rdataset = NULL;
zrdataset = NULL;
sigrdataset = NULL;
zsigrdataset = NULL;
node = NULL;
db = NULL;
zdb = NULL;
version = NULL;
zone = NULL;
if (event != NULL) {
/*
* We're returning from recursion. Restore the query context
* and resume.
*/
want_restart = ISC_FALSE;
authoritative = ISC_FALSE;
clear_fname = ISC_FALSE;
is_zone = ISC_FALSE;
qtype = event->qtype;
if (qtype == dns_rdatatype_sig)
type = dns_rdatatype_any;
else
type = qtype;
db = event->db;
node = event->node;
rdataset = event->rdataset;
sigrdataset = event->sigrdataset;
/*
* We'll need some resources...
*/
dbuf = query_getnamebuf(client);
if (dbuf == NULL) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
fname = query_newname(client, dbuf, &b);
if (fname == NULL) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
tname = dns_fixedname_name(&event->foundname);
result = dns_name_concatenate(tname, NULL, fname, NULL);
if (result != ISC_R_SUCCESS) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
result = event->result;
goto resume;
} else
client->query.qrdataset = NULL;
restart:
want_restart = ISC_FALSE;
authoritative = ISC_FALSE;
clear_fname = ISC_FALSE;
/*
* First we must find the right database.
*/
result = dns_zt_find(client->view->zonetable, client->query.qname,
NULL, &zone);
if (result == DNS_R_SUCCESS || result == DNS_R_PARTIALMATCH)
result = dns_zone_getdb(zone, &db);
if (result == ISC_R_NOTFOUND) {
/*
* We're not directly authoritative for this query name, nor
* is it a subdomain of any zone for which we're
* authoritative.
*/
if (!USECACHE(client)) {
/*
* If we can't use the cache, either because we
* don't have one or because its use has been
* disallowed, there's no more progress we can make
* on this query.
*/
QUERY_ERROR(DNS_R_REFUSED);
goto cleanup;
}
INSIST(client->view->cachedb != NULL);
dns_db_attach(client->view->cachedb, &db);
} else if (result != ISC_R_SUCCESS) {
/*
* Something is broken.
*/
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
is_zone = dns_db_iszone(db);
if (is_zone) {
authoritative = ISC_TRUE;
/*
* Get the current version of this database.
*/
version = query_findversion(client, db);
if (version == NULL) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
} else
version = NULL;
/*
* Find the first unanswered type in the question section.
*/
qtype = 0;
qcount = 0;
client->query.qrdataset = NULL;
for (trdataset = ISC_LIST_HEAD(client->query.origqname->list);
trdataset != NULL;
trdataset = ISC_LIST_NEXT(trdataset, link)) {
if (!ANSWERED(trdataset)) {
if (client->query.qrdataset == NULL) {
client->query.qrdataset = trdataset;
qtype = trdataset->type;
}
qcount++;
}
}
/*
* We had better have found something!
*/
INSIST(client->query.qrdataset != NULL && qcount > 0);
/*
* If there's more than one question, we'll eventually retrieve the
* node and iterate it, trying to find answers. For now, we simply
* refuse requests with more than one question.
*/
if (qcount == 1)
type = qtype;
else {
QUERY_ERROR(DNS_R_REFUSED);
goto cleanup;
}
/*
* See if the type is OK.
*/
result = query_checktype(qtype);
if (result != ISC_R_SUCCESS) {
QUERY_ERROR(result);
goto cleanup;
}
/*
* If it's a SIG query, we'll iterate the node.
*/
if (qtype == dns_rdatatype_sig)
type = dns_rdatatype_any;
db_find:
/*
* We'll need some resources...
*/
dbuf = query_getnamebuf(client);
if (dbuf == NULL) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
fname = query_newname(client, dbuf, &b);
rdataset = query_newrdataset(client);
sigrdataset = query_newrdataset(client);
if (fname == NULL || rdataset == NULL || sigrdataset == NULL) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
/*
* Now look for an answer in the database.
*/
result = dns_db_find(db, client->query.qname, version, type, 0,
client->requesttime, &node, fname, rdataset,
sigrdataset);
resume:
switch (result) {
case DNS_R_SUCCESS:
/*
* This case is handled in the main line below.
*/
break;
case DNS_R_GLUE:
case DNS_R_ZONECUT:
/*
* These cases are handled in the main line below.
*/
INSIST(is_zone);
authoritative = ISC_FALSE;
break;
case DNS_R_NOTFOUND:
/*
* The cache doesn't even have the root NS. Get them from
* the hints DB.
*/
INSIST(!is_zone);
INSIST(client->view->hints != NULL);
dns_db_detach(&db);
dns_db_attach(client->view->hints, &db);
result = dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns,
0, client->requesttime, &node, fname,
rdataset, sigrdataset);
if (result != ISC_R_SUCCESS) {
/*
* We can't even find the hints for the root
* nameservers!
*/
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
/*
* XXXRTH We should trigger root server priming here.
*/
/* FALLTHROUGH */
case DNS_R_DELEGATION:
authoritative = ISC_FALSE;
if (is_zone) {
/*
* We're authoritative for an ancestor of QNAME.
*/
if (!USECACHE(client)) {
/*
* We don't have a cache, so this is the best
* answer.
*
* We enable the retrieval of glue for this
* database by setting client->query.gluedb.
*/
client->query.gluedb = db;
query_addrrset(client, &fname, &rdataset,
&sigrdataset, dbuf,
DNS_SECTION_AUTHORITY);
client->query.gluedb = NULL;
} else {
/*
* We might have a better answer or delegation
* in the cache. We'll remember the current
* values of fname, rdataset, and sigrdataset.
* We'll then go looking for QNAME in the
* cache. If we find something better, we'll
* use it instead.
*/
query_keepname(client, fname, dbuf);
zdb = db;
zfname = fname;
zrdataset = rdataset;
zsigrdataset = sigrdataset;
dns_db_detachnode(db, &node);
version = NULL;
db = NULL;
dns_db_attach(client->view->cachedb, &db);
is_zone = ISC_FALSE;
goto db_find;
}
} else {
if (zfname != NULL &&
!dns_name_issubdomain(fname, zfname)) {
/*
* We've already got a delegation from
* authoritative data, and it is better
* than what we found in the cache. Use
* it instead of the cache delegation.
*/
query_releasename(client, &fname);
fname = zfname;
zfname = NULL;
/*
* We've already done query_keepname() on
* zfname, so we must set dbuf to NULL to
* prevent query_addrrset() from trying to
* call query_keepname() again.
*/
dbuf = NULL;
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
rdataset = zrdataset;
zrdataset = NULL;
sigrdataset = zsigrdataset;
zsigrdataset = NULL;
/*
* We don't clean up zdb here because we
* may still need it. It will get cleaned
* up by the main cleanup code.
*/
}
if (RECURSIONOK(client)) {
/*
* Recurse!
*/
result = query_recurse(client, qtype, fname,
rdataset);
if (result == ISC_R_SUCCESS)
client->query.attributes |=
NS_QUERYATTR_RECURSING;
else
QUERY_ERROR(DNS_R_SERVFAIL);
} else {
/*
* This is the best answer.
*/
client->query.gluedb = zdb;
query_addrrset(client, &fname,
&rdataset, &sigrdataset,
dbuf, DNS_SECTION_AUTHORITY);
client->query.gluedb = NULL;
}
}
goto cleanup;
case DNS_R_NXRDATASET:
INSIST(is_zone);
if (dns_rdataset_isassociated(rdataset)) {
/*
* If we've got a NXT record, we need to save the
* name now because we're going call query_addsoa()
* below, and it needs to use the name buffer.
*/
query_keepname(client, fname, dbuf);
/*
* We don't want the cleanup code to try to release
* fname if we fail below, so we set it to NULL.
*/
tname = fname;
fname = NULL;
} else {
/*
* We're not going to use fname, and need to release
* our hold on the name buffer so query_addsoa()
* may use it.
*/
query_releasename(client, &fname);
}
/*
* Add SOA.
*/
result = query_addsoa(client, db);
if (result != ISC_R_SUCCESS) {
QUERY_ERROR(result);
goto cleanup;
}
/*
* Add NXT record if we found one.
*/
if (dns_rdataset_isassociated(rdataset))
query_addrrset(client, &tname, &rdataset, &sigrdataset,
NULL, DNS_SECTION_AUTHORITY);
goto cleanup;
case DNS_R_NXDOMAIN:
INSIST(is_zone);
if (client->query.restarts > 0) {
/*
* We hit a dead end following a CNAME or DNAME.
*/
goto cleanup;
}
if (dns_rdataset_isassociated(rdataset)) {
/*
* If we've got a NXT record, we need to save the
* name now because we're going call query_addsoa()
* below, and it needs to use the name buffer.
*/
query_keepname(client, fname, dbuf);
/*
* We don't want the cleanup code to try to release
* fname if we fail below, so we set it to NULL.
*/
tname = fname;
fname = NULL;
} else {
/*
* We're not going to use fname, and need to release
* our hold on the name buffer so query_addsoa()
* may use it.
*/
query_releasename(client, &fname);
}
/*
* Add SOA.
*/
result = query_addsoa(client, db);
if (result != ISC_R_SUCCESS) {
QUERY_ERROR(result);
goto cleanup;
}
/*
* Add NXT record if we found one.
*/
if (dns_rdataset_isassociated(rdataset))
query_addrrset(client, &tname, &rdataset, &sigrdataset,
NULL, DNS_SECTION_AUTHORITY);
/*
* Set message rcode.
*/
client->message->rcode = dns_rcode_nxdomain;
goto cleanup;
case DNS_R_NCACHENXDOMAIN:
case DNS_R_NCACHENXRRSET:
INSIST(!is_zone);
authoritative = ISC_FALSE;
/*
* Set message rcode, if required.
*/
if (result == DNS_R_NCACHENXDOMAIN)
client->message->rcode = dns_rcode_nxdomain;
/*
* We don't call query_addrrset() because we don't need any
* of its extra features (and things would probably break!).
*/
query_keepname(client, fname, dbuf);
dns_message_addname(client->message, fname,
DNS_SECTION_AUTHORITY);
ISC_LIST_APPEND(fname->list, rdataset, link);
fname = NULL;
rdataset = NULL;
goto cleanup;
case DNS_R_CNAME:
/*
* Keep a copy of the rdataset. We have to do this because
* query_addrrset may clear 'rdataset' (to prevent the
* cleanup code from cleaning it up).
*/
trdataset = rdataset;
/*
* Add the CNAME to the answer section.
*/
query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
DNS_SECTION_ANSWER);
/*
* We set the PARTIALANSWER attribute so that if anything goes
* wrong later on, we'll return what we've got so far.
*/
client->query.attributes |= NS_QUERYATTR_PARTIALANSWER;
/*
* Reset qname to be the target name of the CNAME and restart
* the query.
*/
tname = NULL;
result = dns_message_gettempname(client->message, &tname);
if (result != ISC_R_SUCCESS)
goto cleanup;
result = dns_rdataset_first(trdataset);
if (result != ISC_R_SUCCESS)
goto cleanup;
dns_rdataset_current(trdataset, &rdata);
r.base = rdata.data;
r.length = rdata.length;
dns_name_init(tname, NULL);
dns_name_fromregion(tname, &r);
query_maybeputqname(client);
client->query.qname = tname;
want_restart = ISC_TRUE;
goto addauth;
case DNS_R_DNAME:
/*
* Compare the current qname to the found name. We need
* to know how many labels and bits are in common because
* we're going to have to split qname later on.
*/
namereln = dns_name_fullcompare(client->query.qname, fname,
&order, &nlabels, &nbits);
INSIST(namereln == dns_namereln_subdomain);
/*
* Keep a copy of the rdataset. We have to do this because
* query_addrrset may clear 'rdataset' (to prevent the
* cleanup code from cleaning it up).
*/
trdataset = rdataset;
/*
* Add the DNAME to the answer section.
*/
query_addrrset(client, &fname, &rdataset, &sigrdataset, dbuf,
DNS_SECTION_ANSWER);
/*
* We set the PARTIALANSWER attribute so that if anything goes
* wrong later on, we'll return what we've got so far.
*/
client->query.attributes |= NS_QUERYATTR_PARTIALANSWER;
/*
* Get the target name of the DNAME.
*/
tname = NULL;
result = dns_message_gettempname(client->message, &tname);
if (result != ISC_R_SUCCESS)
goto cleanup;
result = dns_rdataset_first(trdataset);
if (result != ISC_R_SUCCESS)
goto cleanup;
dns_rdataset_current(trdataset, &rdata);
r.base = rdata.data;
r.length = rdata.length;
dns_name_init(tname, NULL);
dns_name_fromregion(tname, &r);
/*
* Construct the new qname.
*/
dns_fixedname_init(&fixed);
prefix = dns_fixedname_name(&fixed);
result = dns_name_split(client->query.qname, nlabels, nbits,
prefix, NULL);
if (result != ISC_R_SUCCESS)
goto cleanup;
if (fname != NULL)
query_releasename(client, &fname);
dbuf = query_getnamebuf(client);
if (dbuf == NULL)
goto cleanup;
fname = query_newname(client, dbuf, &b);
if (fname == NULL)
goto cleanup;
result = dns_name_concatenate(prefix, tname, fname, NULL);
if (result != ISC_R_SUCCESS) {
dns_message_puttempname(client->message, &tname);
if (result == ISC_R_NOSPACE) {
/*
* RFC 2672, section 4.1, subsection 3c says
* we should return YXDOMAIN if the constructed
* name would be too long.
*/
client->message->rcode = dns_rcode_yxdomain;
}
goto cleanup;
}
query_keepname(client, fname, dbuf);
/*
* Synthesize a CNAME for this DNAME.
*
* We want to synthesize a CNAME since if we don't
* then older software that doesn't understand DNAME
* will not chain like it should.
*
* We do not try to synthesize a signature because we hope
* that security aware servers will understand DNAME. Also,
* even if we had an online key, making a signature
* on-the-fly is costly, and not really legitimate anyway
* since the synthesized CNAME is NOT in the zone.
*/
dns_name_init(tname, NULL);
query_addcname(client, client->query.qname, fname,
trdataset->ttl, &tname);
if (tname != NULL)
dns_message_puttempname(client->message, &tname);
/*
* Switch to the new qname and restart.
*/
query_maybeputqname(client);
client->query.qname = fname;
fname = NULL;
want_restart = ISC_TRUE;
goto addauth;
default:
/*
* Something has gone wrong.
*/
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
if (type == dns_rdatatype_any) {
/*
* XXXRTH Need to handle zonecuts with special case
* code.
*/
n = 0;
rdsiter = NULL;
result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
if (result != ISC_R_SUCCESS) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
result = dns_rdatasetiter_first(rdsiter);
while (result == ISC_R_SUCCESS) {
dns_rdatasetiter_current(rdsiter, rdataset);
if ((qtype == dns_rdatatype_any ||
rdataset->type == qtype) && rdataset->type != 0) {
tname = fname;
query_addrrset(client, &tname, &rdataset, NULL,
dbuf, DNS_SECTION_ANSWER);
n++;
if (tname == NULL) {
clear_fname = ISC_TRUE;
/*
* We set dbuf to NULL because we only
* want the query_keepname() call in
* query_addrrset() to be called once.
*/
dbuf = NULL;
}
/*
* We shouldn't ever fail to add 'rdataset'
* because it's already in the answer.
*/
INSIST(rdataset == NULL);
rdataset = query_newrdataset(client);
if (rdataset == NULL)
break;
} else {
/*
* We're not interested in this rdataset.
*/
dns_rdataset_disassociate(rdataset);
}
result = dns_rdatasetiter_next(rdsiter);
}
if (n > 0) {
if (clear_fname)
fname = NULL;
} else {
/*
* We didn't match any rdatasets.
*/
if (qtype == dns_rdatatype_sig &&
result == DNS_R_NOMORE) {
/*
* XXXRTH If this is a secure zone and we
* didn't find any SIGs, we should generate
* an error unless we were searching for
* glue. Ugh.
*/
/*
* We were searching for SIG records in
* a nonsecure zone. Send a "no error,
* no data" response.
*
* First we must release fname.
*/
query_releasename(client, &fname);
/*
* Add SOA.
*/
result = query_addsoa(client, db);
if (result == ISC_R_SUCCESS)
result = DNS_R_NOMORE;
} else {
/*
* Something went wrong.
*/
result = DNS_R_SERVFAIL;
}
}
dns_rdatasetiter_destroy(&rdsiter);
if (result != DNS_R_NOMORE) {
QUERY_ERROR(DNS_R_SERVFAIL);
goto cleanup;
}
} else {
/*
* This is the "normal" case -- an ordinary question to which
* we know the answer.
*/
tname = fname;
query_addrrset(client, &tname, &rdataset, &sigrdataset, dbuf,
DNS_SECTION_ANSWER);
if (tname == NULL)
clear_fname = ISC_TRUE;
/*
* We shouldn't ever fail to add 'rdataset'
* because it's already in the answer.
*/
INSIST(rdataset == NULL);
/*
* Remember that we've answered this question.
*/
client->query.qrdataset->attributes |=
DNS_RDATASETATTR_ANSWERED;
if (clear_fname)
fname = NULL;
}
addauth:
/*
* Add NS records to the authority section (if we haven't already
* added them to the answer section).
*/
if (!want_restart) {
if (is_zone) {
if (!(qtype == dns_rdatatype_ns &&
dns_name_equal(client->query.qname,
dns_db_origin(db))))
query_addns(client, db);
} else if (qtype != dns_rdatatype_ns) {
if (fname != NULL)
query_releasename(client, &fname);
query_addbestns(client);
}
}
cleanup:
/*
* General cleanup.
*/
query_putrdataset(client, &rdataset);
query_putrdataset(client, &sigrdataset);
if (fname != NULL)
query_releasename(client, &fname);
if (node != NULL)
dns_db_detachnode(db, &node);
if (db != NULL)
dns_db_detach(&db);
if (zone != NULL)
dns_zone_detach(&zone);
if (zdb != NULL) {
query_putrdataset(client, &zrdataset);
query_putrdataset(client, &zsigrdataset);
if (zfname != NULL)
query_releasename(client, &zfname);
dns_db_detach(&zdb);
}
if (event != NULL)
isc_event_free((isc_event_t **)(&event));
/*
* AA bit.
*/
if (client->query.restarts == 0 && !authoritative) {
/*
* We're not authoritative, so we must ensure the AA bit
* isn't set.
*/
client->message->flags &= ~DNS_MESSAGEFLAG_AA;
}
/*
* Restart the query?
*/
if (want_restart && client->query.restarts < MAX_RESTARTS) {
client->query.restarts++;
goto restart;
}
if (eresult != ISC_R_SUCCESS && !PARTIALANSWER(client))
ns_client_error(client, eresult);
else if (!RECURSING(client))
ns_client_send(client);
}
/*
* XXXRTH Problem areas.
*
* If we're authoritative for both a parent and a child, the
* child is non-secure, and we are asked for the KEY of the
* nonsecure child, we need to get it from the parent.
* If we're not auth for the parent, then we have to go
* looking for it in the cache. How do we even know who
* the parent is? We probably won't find this KEY when doing
* additional data KEY retrievals, but that's probably OK,
* since it's a SHOULD not a MUST. We don't want to be doing
* tons of work just to fill out additional data.
*
* Similar problems occur with NXT queries, since there can
* be NXT records at a delegation point in both the parent
* and the child. RFC 2535 section 5.5 says that on explicit
* query we should return both, if available. That seems
* to imply we shouldn't recurse to get the missing one
* if only one is available. Is that right?
*/
void
ns_query_start(ns_client_t *client) {
isc_result_t result;
dns_message_t *message = client->message;
dns_rdataset_t *rdataset;
isc_boolean_t set_ra = ISC_TRUE;
/*
* Ensure that appropriate cleanups occur.
*/
client->next = query_next;
if (client->view->cachedb == NULL) {
/*
* We don't have a cache. Turn off cache support and
* recursion.
*/
client->query.attributes &=
~(NS_QUERYATTR_RECURSIONOK|NS_QUERYATTR_CACHEOK);
set_ra = ISC_FALSE;
} else if ((message->flags & DNS_MESSAGEFLAG_RD) == 0 ||
client->view->resolver == NULL) {
/*
* If the client doesn't want recursion, or we don't have
* a resolver, turn recursion off.
*/
client->query.attributes &= ~NS_QUERYATTR_RECURSIONOK;
set_ra = ISC_FALSE;
}
/*
* XXXRTH Deal with allow-query and allow-recursion here.
*/
/*
* RA flag.
*/
if (set_ra)
message->flags |= DNS_MESSAGEFLAG_RA;
/*
* Get the question name.
*/
result = dns_message_firstname(message, DNS_SECTION_QUESTION);
if (result != ISC_R_SUCCESS) {
ns_client_error(client, result);
return;
}
dns_message_currentname(message, DNS_SECTION_QUESTION,
&client->query.qname);
client->query.origqname = client->query.qname;
result = dns_message_nextname(message, DNS_SECTION_QUESTION);
if (result != ISC_R_NOMORE) {
if (result == ISC_R_SUCCESS) {
/*
* There's more than one QNAME in the question
* section.
*/
ns_client_error(client, DNS_R_FORMERR);
} else
ns_client_error(client, result);
return;
}
/*
* Check for illegal meta-classes and meta-types in
* multiple question queries (edns1 section 5.1).
*/
if (message->counts[DNS_SECTION_QUESTION] > 1) {
if (dns_rdataclass_ismeta(message->rdclass)) {
ns_client_error(client, DNS_R_FORMERR);
return;
}
for (rdataset = ISC_LIST_HEAD(client->query.qname->list);
rdataset != NULL;
rdataset = ISC_LIST_NEXT(rdataset, link)) {
if (dns_rdatatype_ismeta(rdataset->type)) {
ns_client_error(client, DNS_R_FORMERR);
return;
}
}
}
/*
* Check for meta-queries like IXFR and AXFR.
*/
if (message->counts[DNS_SECTION_QUESTION] == 1) {
rdataset = ISC_LIST_HEAD(client->query.qname->list);
INSIST(rdataset != NULL);
if (dns_rdatatype_ismeta(rdataset->type)) {
switch (rdataset->type) {
case dns_rdatatype_any:
break; /* Let query_find handle it. */
case dns_rdatatype_ixfr:
case dns_rdatatype_axfr:
ns_xfr_start(client, rdataset->type);
return;
case dns_rdatatype_maila:
case dns_rdatatype_mailb:
ns_client_error(client, DNS_R_NOTIMP);
return;
default: /* TSIG, etc. */
ns_client_error(client, DNS_R_FORMERR);
return;
}
}
}
/* This is an ordinary query. */
result = dns_message_reply(message, ISC_TRUE);
if (result != ISC_R_SUCCESS) {
ns_client_next(client, result);
return;
}
/*
* Assume authoritative response until it is known to be
* otherwise.
*/
message->flags |= DNS_MESSAGEFLAG_AA;
/*
* Set AD. We need only clear it if we add "pending" data to
* a response.
*
* Note: as currently written, the server does not return "pending"
* data even if a client says it's OK to do so.
*/
message->flags |= DNS_MESSAGEFLAG_AD;
query_find(client, NULL);
}