/* $NetBSD: zt.c,v 1.4.4.1 2024/02/29 12:34:35 martin Exp $ */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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, ¶ms); 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, ¶ms); 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); }