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-rw-r--r--lib/dns/zt.c615
1 files changed, 615 insertions, 0 deletions
diff --git a/lib/dns/zt.c b/lib/dns/zt.c
new file mode 100644
index 0000000..a0c300a
--- /dev/null
+++ b/lib/dns/zt.c
@@ -0,0 +1,615 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/atomic.h>
+#include <isc/file.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/task.h>
+#include <isc/util.h>
+
+#include <dns/log.h>
+#include <dns/name.h>
+#include <dns/rbt.h>
+#include <dns/rdataclass.h>
+#include <dns/view.h>
+#include <dns/zone.h>
+#include <dns/zt.h>
+
+struct zt_load_params {
+ dns_zt_zoneloaded_t dl;
+ bool newonly;
+};
+
+struct dns_zt {
+ /* Unlocked. */
+ unsigned int magic;
+ isc_mem_t *mctx;
+ dns_rdataclass_t rdclass;
+ isc_rwlock_t rwlock;
+ dns_zt_allloaded_t loaddone;
+ void *loaddone_arg;
+ struct zt_load_params *loadparams;
+
+ /* Atomic */
+ atomic_bool flush;
+ isc_refcount_t references;
+ isc_refcount_t loads_pending;
+
+ /* Locked by lock. */
+ dns_rbt_t *table;
+};
+
+struct zt_freeze_params {
+ dns_view_t *view;
+ bool freeze;
+};
+
+#define ZTMAGIC ISC_MAGIC('Z', 'T', 'b', 'l')
+#define VALID_ZT(zt) ISC_MAGIC_VALID(zt, ZTMAGIC)
+
+static void
+auto_detach(void *, void *);
+
+static isc_result_t
+load(dns_zone_t *zone, void *uap);
+
+static isc_result_t
+asyncload(dns_zone_t *zone, void *callback);
+
+static isc_result_t
+freezezones(dns_zone_t *zone, void *uap);
+
+static isc_result_t
+doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task);
+
+isc_result_t
+dns_zt_create(isc_mem_t *mctx, dns_rdataclass_t rdclass, dns_zt_t **ztp) {
+ dns_zt_t *zt;
+ isc_result_t result;
+
+ REQUIRE(ztp != NULL && *ztp == NULL);
+
+ zt = isc_mem_get(mctx, sizeof(*zt));
+
+ zt->table = NULL;
+ result = dns_rbt_create(mctx, auto_detach, zt, &zt->table);
+ if (result != ISC_R_SUCCESS) {
+ goto cleanup_zt;
+ }
+
+ isc_rwlock_init(&zt->rwlock, 0, 0);
+ zt->mctx = NULL;
+ isc_mem_attach(mctx, &zt->mctx);
+ isc_refcount_init(&zt->references, 1);
+ atomic_init(&zt->flush, false);
+ zt->rdclass = rdclass;
+ zt->magic = ZTMAGIC;
+ zt->loaddone = NULL;
+ zt->loaddone_arg = NULL;
+ zt->loadparams = NULL;
+ isc_refcount_init(&zt->loads_pending, 0);
+ *ztp = zt;
+
+ return (ISC_R_SUCCESS);
+
+cleanup_zt:
+ isc_mem_put(mctx, zt, sizeof(*zt));
+
+ return (result);
+}
+
+isc_result_t
+dns_zt_mount(dns_zt_t *zt, dns_zone_t *zone) {
+ isc_result_t result;
+ dns_zone_t *dummy = NULL;
+ dns_name_t *name;
+
+ REQUIRE(VALID_ZT(zt));
+
+ name = dns_zone_getorigin(zone);
+
+ RWLOCK(&zt->rwlock, isc_rwlocktype_write);
+
+ result = dns_rbt_addname(zt->table, name, zone);
+ if (result == ISC_R_SUCCESS) {
+ dns_zone_attach(zone, &dummy);
+ }
+
+ RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
+
+ return (result);
+}
+
+isc_result_t
+dns_zt_unmount(dns_zt_t *zt, dns_zone_t *zone) {
+ isc_result_t result;
+ dns_name_t *name;
+
+ REQUIRE(VALID_ZT(zt));
+
+ name = dns_zone_getorigin(zone);
+
+ RWLOCK(&zt->rwlock, isc_rwlocktype_write);
+
+ result = dns_rbt_deletename(zt->table, name, false);
+
+ RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
+
+ return (result);
+}
+
+isc_result_t
+dns_zt_find(dns_zt_t *zt, const dns_name_t *name, unsigned int options,
+ dns_name_t *foundname, dns_zone_t **zonep) {
+ isc_result_t result;
+ dns_zone_t *dummy = NULL;
+ unsigned int rbtoptions = 0;
+
+ REQUIRE(VALID_ZT(zt));
+
+ if ((options & DNS_ZTFIND_NOEXACT) != 0) {
+ rbtoptions |= DNS_RBTFIND_NOEXACT;
+ }
+
+ RWLOCK(&zt->rwlock, isc_rwlocktype_read);
+
+ result = dns_rbt_findname(zt->table, name, rbtoptions, foundname,
+ (void **)(void *)&dummy);
+ if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
+ /*
+ * If DNS_ZTFIND_MIRROR is set and the zone which was
+ * determined to be the deepest match for the supplied name is
+ * a mirror zone which is expired or not yet loaded, treat it
+ * as non-existent. This will trigger a fallback to recursion
+ * instead of returning a SERVFAIL.
+ *
+ * Note that currently only the deepest match in the zone table
+ * is checked. Consider a server configured with two mirror
+ * zones: "bar" and its child, "foo.bar". If zone data is
+ * available for "bar" but not for "foo.bar", a query with
+ * QNAME equal to or below "foo.bar" will cause ISC_R_NOTFOUND
+ * to be returned, not DNS_R_PARTIALMATCH, despite zone data
+ * being available for "bar". This is considered to be an edge
+ * case, handling which more appropriately is possible, but
+ * arguably not worth the added complexity.
+ */
+ if ((options & DNS_ZTFIND_MIRROR) != 0 &&
+ dns_zone_gettype(dummy) == dns_zone_mirror &&
+ !dns_zone_isloaded(dummy))
+ {
+ result = ISC_R_NOTFOUND;
+ } else {
+ dns_zone_attach(dummy, zonep);
+ }
+ }
+
+ RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
+
+ return (result);
+}
+
+void
+dns_zt_attach(dns_zt_t *zt, dns_zt_t **ztp) {
+ REQUIRE(VALID_ZT(zt));
+ REQUIRE(ztp != NULL && *ztp == NULL);
+
+ isc_refcount_increment(&zt->references);
+
+ *ztp = zt;
+}
+
+static isc_result_t
+flush(dns_zone_t *zone, void *uap) {
+ UNUSED(uap);
+ return (dns_zone_flush(zone));
+}
+
+static void
+zt_destroy(dns_zt_t *zt) {
+ isc_refcount_destroy(&zt->references);
+ isc_refcount_destroy(&zt->loads_pending);
+
+ if (atomic_load_acquire(&zt->flush)) {
+ (void)dns_zt_apply(zt, isc_rwlocktype_none, false, NULL, flush,
+ NULL);
+ }
+
+ dns_rbt_destroy(&zt->table);
+ isc_rwlock_destroy(&zt->rwlock);
+ zt->magic = 0;
+ isc_mem_putanddetach(&zt->mctx, zt, sizeof(*zt));
+}
+
+void
+dns_zt_detach(dns_zt_t **ztp) {
+ dns_zt_t *zt;
+
+ REQUIRE(ztp != NULL && VALID_ZT(*ztp));
+
+ zt = *ztp;
+ *ztp = NULL;
+
+ if (isc_refcount_decrement(&zt->references) == 1) {
+ zt_destroy(zt);
+ }
+}
+
+void
+dns_zt_flush(dns_zt_t *zt) {
+ REQUIRE(VALID_ZT(zt));
+ atomic_store_release(&zt->flush, true);
+}
+
+isc_result_t
+dns_zt_load(dns_zt_t *zt, bool stop, bool newonly) {
+ isc_result_t result;
+ struct zt_load_params params;
+ REQUIRE(VALID_ZT(zt));
+ params.newonly = newonly;
+ result = dns_zt_apply(zt, isc_rwlocktype_read, stop, NULL, load,
+ &params);
+ return (result);
+}
+
+static isc_result_t
+load(dns_zone_t *zone, void *paramsv) {
+ isc_result_t result;
+ struct zt_load_params *params = (struct zt_load_params *)paramsv;
+ result = dns_zone_load(zone, params->newonly);
+ if (result == DNS_R_CONTINUE || result == DNS_R_UPTODATE ||
+ result == DNS_R_DYNAMIC)
+ {
+ result = ISC_R_SUCCESS;
+ }
+ return (result);
+}
+
+static void
+call_loaddone(dns_zt_t *zt) {
+ dns_zt_allloaded_t loaddone = zt->loaddone;
+ void *loaddone_arg = zt->loaddone_arg;
+
+ /*
+ * Set zt->loaddone, zt->loaddone_arg and zt->loadparams to NULL
+ * before calling loaddone.
+ */
+ zt->loaddone = NULL;
+ zt->loaddone_arg = NULL;
+
+ isc_mem_put(zt->mctx, zt->loadparams, sizeof(struct zt_load_params));
+ zt->loadparams = NULL;
+
+ /*
+ * Call the callback last.
+ */
+ if (loaddone != NULL) {
+ loaddone(loaddone_arg);
+ }
+}
+
+isc_result_t
+dns_zt_asyncload(dns_zt_t *zt, bool newonly, dns_zt_allloaded_t alldone,
+ void *arg) {
+ isc_result_t result;
+ uint_fast32_t loads_pending;
+
+ REQUIRE(VALID_ZT(zt));
+
+ /*
+ * Obtain a reference to zt->loads_pending so that asyncload can
+ * safely decrement both zt->references and zt->loads_pending
+ * without going to zero.
+ */
+ loads_pending = isc_refcount_increment0(&zt->loads_pending);
+ INSIST(loads_pending == 0);
+
+ /*
+ * Only one dns_zt_asyncload call at a time should be active so
+ * these pointers should be NULL. They are set back to NULL
+ * before the zt->loaddone (alldone) is called in call_loaddone.
+ */
+ INSIST(zt->loadparams == NULL);
+ INSIST(zt->loaddone == NULL);
+ INSIST(zt->loaddone_arg == NULL);
+
+ zt->loadparams = isc_mem_get(zt->mctx, sizeof(struct zt_load_params));
+ zt->loadparams->dl = doneloading;
+ zt->loadparams->newonly = newonly;
+ zt->loaddone = alldone;
+ zt->loaddone_arg = arg;
+
+ result = dns_zt_apply(zt, isc_rwlocktype_read, false, NULL, asyncload,
+ zt);
+
+ /*
+ * Have all the loads completed?
+ */
+ if (isc_refcount_decrement(&zt->loads_pending) == 1) {
+ call_loaddone(zt);
+ }
+
+ return (result);
+}
+
+/*
+ * Initiates asynchronous loading of zone 'zone'. 'callback' is a
+ * pointer to a function which will be used to inform the caller when
+ * the zone loading is complete.
+ */
+static isc_result_t
+asyncload(dns_zone_t *zone, void *zt_) {
+ isc_result_t result;
+ struct dns_zt *zt = (dns_zt_t *)zt_;
+ REQUIRE(zone != NULL);
+
+ isc_refcount_increment(&zt->references);
+ isc_refcount_increment(&zt->loads_pending);
+
+ result = dns_zone_asyncload(zone, zt->loadparams->newonly,
+ *zt->loadparams->dl, zt);
+ if (result != ISC_R_SUCCESS) {
+ /*
+ * Caller is holding a reference to zt->loads_pending
+ * and zt->references so these can't decrement to zero.
+ */
+ isc_refcount_decrement1(&zt->references);
+ isc_refcount_decrement1(&zt->loads_pending);
+ }
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+dns_zt_freezezones(dns_zt_t *zt, dns_view_t *view, bool freeze) {
+ isc_result_t result, tresult;
+ struct zt_freeze_params params = { view, freeze };
+
+ REQUIRE(VALID_ZT(zt));
+
+ result = dns_zt_apply(zt, isc_rwlocktype_read, false, &tresult,
+ freezezones, &params);
+ if (tresult == ISC_R_NOTFOUND) {
+ tresult = ISC_R_SUCCESS;
+ }
+ return ((result == ISC_R_SUCCESS) ? tresult : result);
+}
+
+static isc_result_t
+freezezones(dns_zone_t *zone, void *uap) {
+ struct zt_freeze_params *params = uap;
+ bool frozen;
+ isc_result_t result = ISC_R_SUCCESS;
+ char classstr[DNS_RDATACLASS_FORMATSIZE];
+ char zonename[DNS_NAME_FORMATSIZE];
+ dns_zone_t *raw = NULL;
+ dns_view_t *view;
+ const char *vname;
+ const char *sep;
+ int level;
+
+ dns_zone_getraw(zone, &raw);
+ if (raw != NULL) {
+ zone = raw;
+ }
+ if (params->view != dns_zone_getview(zone)) {
+ if (raw != NULL) {
+ dns_zone_detach(&raw);
+ }
+ return (ISC_R_SUCCESS);
+ }
+ if (dns_zone_gettype(zone) != dns_zone_primary) {
+ if (raw != NULL) {
+ dns_zone_detach(&raw);
+ }
+ return (ISC_R_SUCCESS);
+ }
+ if (!dns_zone_isdynamic(zone, true)) {
+ if (raw != NULL) {
+ dns_zone_detach(&raw);
+ }
+ return (ISC_R_SUCCESS);
+ }
+
+ frozen = dns_zone_getupdatedisabled(zone);
+ if (params->freeze) {
+ if (frozen) {
+ result = DNS_R_FROZEN;
+ }
+ if (result == ISC_R_SUCCESS) {
+ result = dns_zone_flush(zone);
+ }
+ if (result == ISC_R_SUCCESS) {
+ dns_zone_setupdatedisabled(zone, params->freeze);
+ }
+ } else {
+ if (frozen) {
+ result = dns_zone_loadandthaw(zone);
+ if (result == DNS_R_CONTINUE ||
+ result == DNS_R_UPTODATE)
+ {
+ result = ISC_R_SUCCESS;
+ }
+ }
+ }
+ view = dns_zone_getview(zone);
+ if (strcmp(view->name, "_bind") == 0 || strcmp(view->name, "_defaul"
+ "t") == 0)
+ {
+ vname = "";
+ sep = "";
+ } else {
+ vname = view->name;
+ sep = " ";
+ }
+ dns_rdataclass_format(dns_zone_getclass(zone), classstr,
+ sizeof(classstr));
+ dns_name_format(dns_zone_getorigin(zone), zonename, sizeof(zonename));
+ level = (result != ISC_R_SUCCESS) ? ISC_LOG_ERROR : ISC_LOG_DEBUG(1);
+ isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
+ level, "%s zone '%s/%s'%s%s: %s",
+ params->freeze ? "freezing" : "thawing", zonename,
+ classstr, sep, vname, isc_result_totext(result));
+ if (raw != NULL) {
+ dns_zone_detach(&raw);
+ }
+ return (result);
+}
+
+void
+dns_zt_setviewcommit(dns_zt_t *zt) {
+ dns_rbtnode_t *node;
+ dns_rbtnodechain_t chain;
+ isc_result_t result;
+
+ REQUIRE(VALID_ZT(zt));
+
+ RWLOCK(&zt->rwlock, isc_rwlocktype_read);
+ dns_rbtnodechain_init(&chain);
+
+ result = dns_rbtnodechain_first(&chain, zt->table, NULL, NULL);
+ while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
+ result = dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+ if (result == ISC_R_SUCCESS && node->data != NULL) {
+ dns_zone_setviewcommit(node->data);
+ }
+
+ result = dns_rbtnodechain_next(&chain, NULL, NULL);
+ }
+
+ dns_rbtnodechain_invalidate(&chain);
+ RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
+}
+
+void
+dns_zt_setviewrevert(dns_zt_t *zt) {
+ dns_rbtnode_t *node;
+ dns_rbtnodechain_t chain;
+ isc_result_t result;
+
+ REQUIRE(VALID_ZT(zt));
+
+ dns_rbtnodechain_init(&chain);
+
+ result = dns_rbtnodechain_first(&chain, zt->table, NULL, NULL);
+ while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
+ result = dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+ if (result == ISC_R_SUCCESS && node->data != NULL) {
+ dns_zone_setviewrevert(node->data);
+ }
+
+ result = dns_rbtnodechain_next(&chain, NULL, NULL);
+ }
+
+ dns_rbtnodechain_invalidate(&chain);
+}
+
+isc_result_t
+dns_zt_apply(dns_zt_t *zt, isc_rwlocktype_t lock, bool stop, isc_result_t *sub,
+ isc_result_t (*action)(dns_zone_t *, void *), void *uap) {
+ dns_rbtnode_t *node;
+ dns_rbtnodechain_t chain;
+ isc_result_t result, tresult = ISC_R_SUCCESS;
+ dns_zone_t *zone;
+
+ REQUIRE(VALID_ZT(zt));
+ REQUIRE(action != NULL);
+
+ if (lock != isc_rwlocktype_none) {
+ RWLOCK(&zt->rwlock, lock);
+ }
+
+ dns_rbtnodechain_init(&chain);
+ result = dns_rbtnodechain_first(&chain, zt->table, NULL, NULL);
+ if (result == ISC_R_NOTFOUND) {
+ /*
+ * The tree is empty.
+ */
+ tresult = result;
+ result = ISC_R_NOMORE;
+ }
+ while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
+ result = dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+ if (result == ISC_R_SUCCESS) {
+ zone = node->data;
+ if (zone != NULL) {
+ result = (action)(zone, uap);
+ }
+ if (result != ISC_R_SUCCESS && stop) {
+ tresult = result;
+ goto cleanup; /* don't break */
+ } else if (result != ISC_R_SUCCESS &&
+ tresult == ISC_R_SUCCESS)
+ {
+ tresult = result;
+ }
+ }
+ result = dns_rbtnodechain_next(&chain, NULL, NULL);
+ }
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+
+cleanup:
+ dns_rbtnodechain_invalidate(&chain);
+ if (sub != NULL) {
+ *sub = tresult;
+ }
+
+ if (lock != isc_rwlocktype_none) {
+ RWUNLOCK(&zt->rwlock, lock);
+ }
+
+ return (result);
+}
+
+/*
+ * Decrement the loads_pending counter; when counter reaches
+ * zero, call the loaddone callback that was initially set by
+ * dns_zt_asyncload().
+ */
+static isc_result_t
+doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task) {
+ UNUSED(zone);
+ UNUSED(task);
+
+ REQUIRE(VALID_ZT(zt));
+
+ if (isc_refcount_decrement(&zt->loads_pending) == 1) {
+ call_loaddone(zt);
+ }
+
+ if (isc_refcount_decrement(&zt->references) == 1) {
+ zt_destroy(zt);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+/***
+ *** Private
+ ***/
+
+static void
+auto_detach(void *data, void *arg) {
+ dns_zone_t *zone = data;
+
+ UNUSED(arg);
+ dns_zone_detach(&zone);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 17:56:46 +0000