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bind/bin/named/query.c
Bob Halley d680c5e7d5 Do not free client->query.qname prematurely. 
Detach from our fetch as soon as it is done.  (Not doing this meant we
couldn't recurse again when restarting.)
Fix some bugs in the multiple question code that were causing qtype to be
set incorrectly when restarting after recursion.
1999-10-17 19:27:04 +00:00

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/*
* 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/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.
*/
/*
* If there is an active fetch for this client, cancel it.
*/
if (client->query.fetch != NULL) {
dns_resolver_destroyfetch(client->view->resolver,
&client->query.fetch);
}
/*
* 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, nxglue, 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;
nxglue = ISC_FALSE;
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);
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 (result == DNS_R_NXGLUE) {
/*
* XXXRTH Explain NXGLUE here.
*/
nxglue = ISC_TRUE;
}
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.
*
* 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. Note: we do NOT include A6 in the
* list of types with such treatment.
*
* 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 inline 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,
isc_boolean_t check_ad)
{
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;
} else if (check_ad && (section == DNS_SECTION_ANSWER ||
section == DNS_SECTION_AUTHORITY)) {
/*
* We just added nonauthenticated data to the answer
* section.
*/
client->message->flags &= ~DNS_MESSAGEFLAG_AD;
}
}
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, ISC_TRUE);
}
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, ISC_TRUE);
}
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_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 inline void
query_a6additional(ns_client_t *client, dns_db_t *db, dns_dbnode_t *node,
dns_dbversion_t *version, dns_name_t *name)
{
dns_name_t *fname, *tname;
dns_rdatatype_t type;
dns_rdataset_t *rdataset;
dns_rdatasetiter_t *rdsiter;
isc_result_t result;
/*
* Doing an A6 query causes type A and type AAAA additional section
* processing for QNAME, which we handle here.
*
* XXXRTH This will probably not be required in the next
* dns-lookups draft, and we'll remove it when the
* draft comes out.
*/
fname = NULL;
result = dns_message_gettempname(client->message, &fname);
if (result != ISC_R_SUCCESS)
return;
dns_name_init(fname, NULL);
dns_name_clone(name, fname);
rdsiter = NULL;
result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
if (result != ISC_R_SUCCESS)
return;
result = dns_rdatasetiter_first(rdsiter);
while (result == ISC_R_SUCCESS) {
rdataset = query_newrdataset(client);
if (rdataset == NULL)
break;
dns_rdatasetiter_current(rdsiter, rdataset);
type = rdataset->type;
if (type == dns_rdatatype_sig)
type = rdataset->covers;
if (type == dns_rdatatype_a || type == dns_rdatatype_aaaa) {
tname = fname;
query_addrrset(client, &tname, &rdataset, NULL,
NULL, DNS_SECTION_ADDITIONAL,
ISC_FALSE);
if (rdataset != NULL) {
/*
* We've already got this one.
*/
query_putrdataset(client, &rdataset);
}
} else {
/*
* We're not interested in this rdataset.
*/
query_putrdataset(client, &rdataset);
}
result = dns_rdatasetiter_next(rdsiter);
}
dns_rdatasetiter_destroy(&rdsiter);
}
static void
query_resume(isc_task_t *task, isc_event_t *event) {
dns_fetchevent_t *devent = (dns_fetchevent_t *)event;
ns_client_t *client;
/*
* 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));
client->query.attributes &= ~NS_QUERYATTR_RECURSING;
dns_resolver_destroyfetch(client->view->resolver,
&client->query.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).
*/
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;
}
}
/*
* 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,
ISC_TRUE);
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,
ISC_TRUE);
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, ISC_TRUE);
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, ISC_TRUE);
/*
* 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;
/*
* XXXRTH Deal with AD bit.
*/
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, ISC_TRUE);
/*
* 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, ISC_TRUE);
/*
* 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 and restart the query.
*/
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) {
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);
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) {
/*
* XXXRTH AD bit checking.
*/
tname = fname;
query_addrrset(client, &tname, &rdataset, NULL,
dbuf, DNS_SECTION_ANSWER,
ISC_FALSE);
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, ISC_TRUE);
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;
/*
* A6 records cause type A and AAAA additional
* section processign for the QNAME.
*
* XXXRTH This will probably not be required in the next
* dns-lookups draft, and we'll remove it when the
* draft comes out.
*/
if (qtype == dns_rdatatype_a6) {
if (!clear_fname) {
/*
* We haven't used fname yet, but we're going
* to need it now.
*/
query_keepname(client, fname, dbuf);
clear_fname = ISC_TRUE;
}
query_a6additional(client, db, node, version, fname);
}
if (clear_fname)
fname = NULL;
}
/*
* XXXRTH Handle additional questions above. Find all the question
* types we can from the node we found, and (if recursion is
* OK) launch queries for any types we don't have answers to.
*/
addauth:
/*
* Add NS records for the zone to the authority section (if we
* haven't already added them to the answer section).
*/
if (client->query.restarts == 0 &&
is_zone &&
!(qtype == dns_rdatatype_ns &&
dns_name_equal(client->query.qname, dns_db_origin(db))))
query_addns(client, db);
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;
#ifdef notyet
/*
* Assume authenticated response until it is known to be
* otherwise.
*/
message->flags |= DNS_MESSAGEFLAG_AD;
#endif
query_find(client, NULL);
}
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