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-rw-r--r--lib/dns/diff.c686
1 files changed, 686 insertions, 0 deletions
diff --git a/lib/dns/diff.c b/lib/dns/diff.c
new file mode 100644
index 0000000..52f5aca
--- /dev/null
+++ b/lib/dns/diff.c
@@ -0,0 +1,686 @@
+/*
+ * 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 <stdlib.h>
+
+#include <isc/buffer.h>
+#include <isc/file.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#include <dns/db.h>
+#include <dns/diff.h>
+#include <dns/log.h>
+#include <dns/rdataclass.h>
+#include <dns/rdatalist.h>
+#include <dns/rdataset.h>
+#include <dns/rdatastruct.h>
+#include <dns/rdatatype.h>
+#include <dns/time.h>
+
+#define CHECK(op) \
+ do { \
+ result = (op); \
+ if (result != ISC_R_SUCCESS) \
+ goto failure; \
+ } while (0)
+
+#define DIFF_COMMON_LOGARGS \
+ dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_DIFF
+
+static dns_rdatatype_t
+rdata_covers(dns_rdata_t *rdata) {
+ return (rdata->type == dns_rdatatype_rrsig ? dns_rdata_covers(rdata)
+ : 0);
+}
+
+isc_result_t
+dns_difftuple_create(isc_mem_t *mctx, dns_diffop_t op, const dns_name_t *name,
+ dns_ttl_t ttl, dns_rdata_t *rdata, dns_difftuple_t **tp) {
+ dns_difftuple_t *t;
+ unsigned int size;
+ unsigned char *datap;
+
+ REQUIRE(tp != NULL && *tp == NULL);
+
+ /*
+ * Create a new tuple. The variable-size wire-format name data and
+ * rdata immediately follow the dns_difftuple_t structure
+ * in memory.
+ */
+ size = sizeof(*t) + name->length + rdata->length;
+ t = isc_mem_allocate(mctx, size);
+ t->mctx = NULL;
+ isc_mem_attach(mctx, &t->mctx);
+ t->op = op;
+
+ datap = (unsigned char *)(t + 1);
+
+ memmove(datap, name->ndata, name->length);
+ dns_name_init(&t->name, NULL);
+ dns_name_clone(name, &t->name);
+ t->name.ndata = datap;
+ datap += name->length;
+
+ t->ttl = ttl;
+
+ dns_rdata_init(&t->rdata);
+ dns_rdata_clone(rdata, &t->rdata);
+ if (rdata->data != NULL) {
+ memmove(datap, rdata->data, rdata->length);
+ t->rdata.data = datap;
+ datap += rdata->length;
+ } else {
+ t->rdata.data = NULL;
+ INSIST(rdata->length == 0);
+ }
+
+ ISC_LINK_INIT(&t->rdata, link);
+ ISC_LINK_INIT(t, link);
+ t->magic = DNS_DIFFTUPLE_MAGIC;
+
+ INSIST(datap == (unsigned char *)t + size);
+
+ *tp = t;
+ return (ISC_R_SUCCESS);
+}
+
+void
+dns_difftuple_free(dns_difftuple_t **tp) {
+ dns_difftuple_t *t = *tp;
+ *tp = NULL;
+ isc_mem_t *mctx;
+
+ REQUIRE(DNS_DIFFTUPLE_VALID(t));
+
+ dns_name_invalidate(&t->name);
+ t->magic = 0;
+ mctx = t->mctx;
+ isc_mem_free(mctx, t);
+ isc_mem_detach(&mctx);
+}
+
+isc_result_t
+dns_difftuple_copy(dns_difftuple_t *orig, dns_difftuple_t **copyp) {
+ return (dns_difftuple_create(orig->mctx, orig->op, &orig->name,
+ orig->ttl, &orig->rdata, copyp));
+}
+
+void
+dns_diff_init(isc_mem_t *mctx, dns_diff_t *diff) {
+ diff->mctx = mctx;
+ ISC_LIST_INIT(diff->tuples);
+ diff->magic = DNS_DIFF_MAGIC;
+}
+
+void
+dns_diff_clear(dns_diff_t *diff) {
+ dns_difftuple_t *t;
+ REQUIRE(DNS_DIFF_VALID(diff));
+ while ((t = ISC_LIST_HEAD(diff->tuples)) != NULL) {
+ ISC_LIST_UNLINK(diff->tuples, t, link);
+ dns_difftuple_free(&t);
+ }
+ ENSURE(ISC_LIST_EMPTY(diff->tuples));
+}
+
+void
+dns_diff_append(dns_diff_t *diff, dns_difftuple_t **tuplep) {
+ ISC_LIST_APPEND(diff->tuples, *tuplep, link);
+ *tuplep = NULL;
+}
+
+/* XXX this is O(N) */
+
+void
+dns_diff_appendminimal(dns_diff_t *diff, dns_difftuple_t **tuplep) {
+ dns_difftuple_t *ot, *next_ot;
+
+ REQUIRE(DNS_DIFF_VALID(diff));
+ REQUIRE(DNS_DIFFTUPLE_VALID(*tuplep));
+
+ /*
+ * Look for an existing tuple with the same owner name,
+ * rdata, and TTL. If we are doing an addition and find a
+ * deletion or vice versa, remove both the old and the
+ * new tuple since they cancel each other out (assuming
+ * that we never delete nonexistent data or add existing
+ * data).
+ *
+ * If we find an old update of the same kind as
+ * the one we are doing, there must be a programming
+ * error. We report it but try to continue anyway.
+ */
+ for (ot = ISC_LIST_HEAD(diff->tuples); ot != NULL; ot = next_ot) {
+ next_ot = ISC_LIST_NEXT(ot, link);
+ if (dns_name_caseequal(&ot->name, &(*tuplep)->name) &&
+ dns_rdata_compare(&ot->rdata, &(*tuplep)->rdata) == 0 &&
+ ot->ttl == (*tuplep)->ttl)
+ {
+ ISC_LIST_UNLINK(diff->tuples, ot, link);
+ if ((*tuplep)->op == ot->op) {
+ UNEXPECTED_ERROR("unexpected non-minimal diff");
+ } else {
+ dns_difftuple_free(tuplep);
+ }
+ dns_difftuple_free(&ot);
+ break;
+ }
+ }
+
+ if (*tuplep != NULL) {
+ ISC_LIST_APPEND(diff->tuples, *tuplep, link);
+ *tuplep = NULL;
+ }
+}
+
+static isc_stdtime_t
+setresign(dns_rdataset_t *modified) {
+ dns_rdata_t rdata = DNS_RDATA_INIT;
+ dns_rdata_rrsig_t sig;
+ int64_t when;
+ isc_result_t result;
+
+ result = dns_rdataset_first(modified);
+ INSIST(result == ISC_R_SUCCESS);
+ dns_rdataset_current(modified, &rdata);
+ (void)dns_rdata_tostruct(&rdata, &sig, NULL);
+ if ((rdata.flags & DNS_RDATA_OFFLINE) != 0) {
+ when = 0;
+ } else {
+ when = dns_time64_from32(sig.timeexpire);
+ }
+ dns_rdata_reset(&rdata);
+
+ result = dns_rdataset_next(modified);
+ while (result == ISC_R_SUCCESS) {
+ dns_rdataset_current(modified, &rdata);
+ (void)dns_rdata_tostruct(&rdata, &sig, NULL);
+ if ((rdata.flags & DNS_RDATA_OFFLINE) != 0) {
+ goto next_rr;
+ }
+ if (when == 0 || dns_time64_from32(sig.timeexpire) < when) {
+ when = dns_time64_from32(sig.timeexpire);
+ }
+ next_rr:
+ dns_rdata_reset(&rdata);
+ result = dns_rdataset_next(modified);
+ }
+ INSIST(result == ISC_R_NOMORE);
+ return ((isc_stdtime_t)when);
+}
+
+static void
+getownercase(dns_rdataset_t *rdataset, dns_name_t *name) {
+ if (dns_rdataset_isassociated(rdataset)) {
+ dns_rdataset_getownercase(rdataset, name);
+ }
+}
+
+static void
+setownercase(dns_rdataset_t *rdataset, const dns_name_t *name) {
+ if (dns_rdataset_isassociated(rdataset)) {
+ dns_rdataset_setownercase(rdataset, name);
+ }
+}
+
+static isc_result_t
+diff_apply(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver, bool warn) {
+ dns_difftuple_t *t;
+ dns_dbnode_t *node = NULL;
+ isc_result_t result;
+ char namebuf[DNS_NAME_FORMATSIZE];
+ char typebuf[DNS_RDATATYPE_FORMATSIZE];
+ char classbuf[DNS_RDATACLASS_FORMATSIZE];
+
+ REQUIRE(DNS_DIFF_VALID(diff));
+ REQUIRE(DNS_DB_VALID(db));
+
+ t = ISC_LIST_HEAD(diff->tuples);
+ while (t != NULL) {
+ dns_name_t *name;
+
+ INSIST(node == NULL);
+ name = &t->name;
+ /*
+ * Find the node.
+ * We create the node if it does not exist.
+ * This will cause an empty node to be created if the diff
+ * contains a deletion of an RR at a nonexistent name,
+ * but such diffs should never be created in the first
+ * place.
+ */
+
+ while (t != NULL && dns_name_equal(&t->name, name)) {
+ dns_rdatatype_t type, covers;
+ dns_diffop_t op;
+ dns_rdatalist_t rdl;
+ dns_rdataset_t rds;
+ dns_rdataset_t ardataset;
+ unsigned int options;
+
+ op = t->op;
+ type = t->rdata.type;
+ covers = rdata_covers(&t->rdata);
+
+ /*
+ * Collect a contiguous set of updates with
+ * the same operation (add/delete) and RR type
+ * into a single rdatalist so that the
+ * database rrset merging/subtraction code
+ * can work more efficiently than if each
+ * RR were merged into / subtracted from
+ * the database separately.
+ *
+ * This is done by linking rdata structures from the
+ * diff into "rdatalist". This uses the rdata link
+ * field, not the diff link field, so the structure
+ * of the diff itself is not affected.
+ */
+
+ dns_rdatalist_init(&rdl);
+ rdl.type = type;
+ rdl.covers = covers;
+ rdl.rdclass = t->rdata.rdclass;
+ rdl.ttl = t->ttl;
+
+ node = NULL;
+ if (type != dns_rdatatype_nsec3 &&
+ covers != dns_rdatatype_nsec3)
+ {
+ CHECK(dns_db_findnode(db, name, true, &node));
+ } else {
+ CHECK(dns_db_findnsec3node(db, name, true,
+ &node));
+ }
+
+ while (t != NULL && dns_name_equal(&t->name, name) &&
+ t->op == op && t->rdata.type == type &&
+ rdata_covers(&t->rdata) == covers)
+ {
+ /*
+ * Remember the add name for
+ * dns_rdataset_setownercase.
+ */
+ name = &t->name;
+ if (t->ttl != rdl.ttl && warn) {
+ dns_name_format(name, namebuf,
+ sizeof(namebuf));
+ dns_rdatatype_format(t->rdata.type,
+ typebuf,
+ sizeof(typebuf));
+ dns_rdataclass_format(t->rdata.rdclass,
+ classbuf,
+ sizeof(classbuf));
+ isc_log_write(DIFF_COMMON_LOGARGS,
+ ISC_LOG_WARNING,
+ "'%s/%s/%s': TTL differs "
+ "in "
+ "rdataset, adjusting "
+ "%lu -> %lu",
+ namebuf, typebuf,
+ classbuf,
+ (unsigned long)t->ttl,
+ (unsigned long)rdl.ttl);
+ }
+ ISC_LIST_APPEND(rdl.rdata, &t->rdata, link);
+ t = ISC_LIST_NEXT(t, link);
+ }
+
+ /*
+ * Convert the rdatalist into a rdataset.
+ */
+ dns_rdataset_init(&rds);
+ dns_rdataset_init(&ardataset);
+ CHECK(dns_rdatalist_tordataset(&rdl, &rds));
+ rds.trust = dns_trust_ultimate;
+
+ /*
+ * Merge the rdataset into the database.
+ */
+ switch (op) {
+ case DNS_DIFFOP_ADD:
+ case DNS_DIFFOP_ADDRESIGN:
+ options = DNS_DBADD_MERGE | DNS_DBADD_EXACT |
+ DNS_DBADD_EXACTTTL;
+ result = dns_db_addrdataset(db, node, ver, 0,
+ &rds, options,
+ &ardataset);
+ break;
+ case DNS_DIFFOP_DEL:
+ case DNS_DIFFOP_DELRESIGN:
+ options = DNS_DBSUB_EXACT | DNS_DBSUB_WANTOLD;
+ result = dns_db_subtractrdataset(db, node, ver,
+ &rds, options,
+ &ardataset);
+ break;
+ default:
+ UNREACHABLE();
+ }
+
+ if (result == ISC_R_SUCCESS) {
+ if (rds.type == dns_rdatatype_rrsig &&
+ (op == DNS_DIFFOP_DELRESIGN ||
+ op == DNS_DIFFOP_ADDRESIGN))
+ {
+ isc_stdtime_t resign;
+ resign = setresign(&ardataset);
+ dns_db_setsigningtime(db, &ardataset,
+ resign);
+ }
+ if (op == DNS_DIFFOP_ADD ||
+ op == DNS_DIFFOP_ADDRESIGN)
+ {
+ setownercase(&ardataset, name);
+ }
+ if (op == DNS_DIFFOP_DEL ||
+ op == DNS_DIFFOP_DELRESIGN)
+ {
+ getownercase(&ardataset, name);
+ }
+ } else if (result == DNS_R_UNCHANGED) {
+ /*
+ * This will not happen when executing a
+ * dynamic update, because that code will
+ * generate strictly minimal diffs.
+ * It may happen when receiving an IXFR
+ * from a server that is not as careful.
+ * Issue a warning and continue.
+ */
+ if (warn) {
+ dns_name_format(dns_db_origin(db),
+ namebuf,
+ sizeof(namebuf));
+ dns_rdataclass_format(dns_db_class(db),
+ classbuf,
+ sizeof(classbuf));
+ isc_log_write(DIFF_COMMON_LOGARGS,
+ ISC_LOG_WARNING,
+ "%s/%s: dns_diff_apply: "
+ "update with no effect",
+ namebuf, classbuf);
+ }
+ if (op == DNS_DIFFOP_ADD ||
+ op == DNS_DIFFOP_ADDRESIGN)
+ {
+ setownercase(&ardataset, name);
+ }
+ if (op == DNS_DIFFOP_DEL ||
+ op == DNS_DIFFOP_DELRESIGN)
+ {
+ getownercase(&ardataset, name);
+ }
+ } else if (result == DNS_R_NXRRSET) {
+ /*
+ * OK.
+ */
+ if (op == DNS_DIFFOP_DEL ||
+ op == DNS_DIFFOP_DELRESIGN)
+ {
+ getownercase(&ardataset, name);
+ }
+ if (dns_rdataset_isassociated(&ardataset)) {
+ dns_rdataset_disassociate(&ardataset);
+ }
+ } else {
+ if (dns_rdataset_isassociated(&ardataset)) {
+ dns_rdataset_disassociate(&ardataset);
+ }
+ CHECK(result);
+ }
+ dns_db_detachnode(db, &node);
+ if (dns_rdataset_isassociated(&ardataset)) {
+ dns_rdataset_disassociate(&ardataset);
+ }
+ }
+ }
+ return (ISC_R_SUCCESS);
+
+failure:
+ if (node != NULL) {
+ dns_db_detachnode(db, &node);
+ }
+ return (result);
+}
+
+isc_result_t
+dns_diff_apply(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver) {
+ return (diff_apply(diff, db, ver, true));
+}
+
+isc_result_t
+dns_diff_applysilently(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver) {
+ return (diff_apply(diff, db, ver, false));
+}
+
+/* XXX this duplicates lots of code in diff_apply(). */
+
+isc_result_t
+dns_diff_load(dns_diff_t *diff, dns_addrdatasetfunc_t addfunc,
+ void *add_private) {
+ dns_difftuple_t *t;
+ isc_result_t result;
+
+ REQUIRE(DNS_DIFF_VALID(diff));
+
+ t = ISC_LIST_HEAD(diff->tuples);
+ while (t != NULL) {
+ dns_name_t *name;
+
+ name = &t->name;
+ while (t != NULL && dns_name_caseequal(&t->name, name)) {
+ dns_rdatatype_t type, covers;
+ dns_diffop_t op;
+ dns_rdatalist_t rdl;
+ dns_rdataset_t rds;
+
+ op = t->op;
+ type = t->rdata.type;
+ covers = rdata_covers(&t->rdata);
+
+ dns_rdatalist_init(&rdl);
+ rdl.type = type;
+ rdl.covers = covers;
+ rdl.rdclass = t->rdata.rdclass;
+ rdl.ttl = t->ttl;
+
+ while (t != NULL &&
+ dns_name_caseequal(&t->name, name) &&
+ t->op == op && t->rdata.type == type &&
+ rdata_covers(&t->rdata) == covers)
+ {
+ ISC_LIST_APPEND(rdl.rdata, &t->rdata, link);
+ t = ISC_LIST_NEXT(t, link);
+ }
+
+ /*
+ * Convert the rdatalist into a rdataset.
+ */
+ dns_rdataset_init(&rds);
+ CHECK(dns_rdatalist_tordataset(&rdl, &rds));
+ rds.trust = dns_trust_ultimate;
+
+ INSIST(op == DNS_DIFFOP_ADD);
+ result = (*addfunc)(add_private, name, &rds);
+ if (result == DNS_R_UNCHANGED) {
+ isc_log_write(DIFF_COMMON_LOGARGS,
+ ISC_LOG_WARNING,
+ "dns_diff_load: "
+ "update with no effect");
+ } else if (result == ISC_R_SUCCESS ||
+ result == DNS_R_NXRRSET)
+ {
+ /*
+ * OK.
+ */
+ } else {
+ CHECK(result);
+ }
+ }
+ }
+ result = ISC_R_SUCCESS;
+failure:
+ return (result);
+}
+
+/*
+ * XXX uses qsort(); a merge sort would be more natural for lists,
+ * and perhaps safer wrt thread stack overflow.
+ */
+isc_result_t
+dns_diff_sort(dns_diff_t *diff, dns_diff_compare_func *compare) {
+ unsigned int length = 0;
+ unsigned int i;
+ dns_difftuple_t **v;
+ dns_difftuple_t *p;
+ REQUIRE(DNS_DIFF_VALID(diff));
+
+ for (p = ISC_LIST_HEAD(diff->tuples); p != NULL;
+ p = ISC_LIST_NEXT(p, link))
+ {
+ length++;
+ }
+ if (length == 0) {
+ return (ISC_R_SUCCESS);
+ }
+ v = isc_mem_get(diff->mctx, length * sizeof(dns_difftuple_t *));
+ for (i = 0; i < length; i++) {
+ p = ISC_LIST_HEAD(diff->tuples);
+ v[i] = p;
+ ISC_LIST_UNLINK(diff->tuples, p, link);
+ }
+ INSIST(ISC_LIST_HEAD(diff->tuples) == NULL);
+ qsort(v, length, sizeof(v[0]), compare);
+ for (i = 0; i < length; i++) {
+ ISC_LIST_APPEND(diff->tuples, v[i], link);
+ }
+ isc_mem_put(diff->mctx, v, length * sizeof(dns_difftuple_t *));
+ return (ISC_R_SUCCESS);
+}
+
+/*
+ * Create an rdataset containing the single RR of the given
+ * tuple. The caller must allocate the rdata, rdataset and
+ * an rdatalist structure for it to refer to.
+ */
+
+static isc_result_t
+diff_tuple_tordataset(dns_difftuple_t *t, dns_rdata_t *rdata,
+ dns_rdatalist_t *rdl, dns_rdataset_t *rds) {
+ REQUIRE(DNS_DIFFTUPLE_VALID(t));
+ REQUIRE(rdl != NULL);
+ REQUIRE(rds != NULL);
+
+ dns_rdatalist_init(rdl);
+ rdl->type = t->rdata.type;
+ rdl->rdclass = t->rdata.rdclass;
+ rdl->ttl = t->ttl;
+ dns_rdataset_init(rds);
+ ISC_LINK_INIT(rdata, link);
+ dns_rdata_clone(&t->rdata, rdata);
+ ISC_LIST_APPEND(rdl->rdata, rdata, link);
+ return (dns_rdatalist_tordataset(rdl, rds));
+}
+
+isc_result_t
+dns_diff_print(dns_diff_t *diff, FILE *file) {
+ isc_result_t result;
+ dns_difftuple_t *t;
+ char *mem = NULL;
+ unsigned int size = 2048;
+ const char *op = NULL;
+
+ REQUIRE(DNS_DIFF_VALID(diff));
+
+ mem = isc_mem_get(diff->mctx, size);
+
+ for (t = ISC_LIST_HEAD(diff->tuples); t != NULL;
+ t = ISC_LIST_NEXT(t, link))
+ {
+ isc_buffer_t buf;
+ isc_region_t r;
+
+ dns_rdatalist_t rdl;
+ dns_rdataset_t rds;
+ dns_rdata_t rd = DNS_RDATA_INIT;
+
+ result = diff_tuple_tordataset(t, &rd, &rdl, &rds);
+ if (result != ISC_R_SUCCESS) {
+ UNEXPECTED_ERROR("diff_tuple_tordataset failed: %s",
+ isc_result_totext(result));
+ result = ISC_R_UNEXPECTED;
+ goto cleanup;
+ }
+ again:
+ isc_buffer_init(&buf, mem, size);
+ result = dns_rdataset_totext(&rds, &t->name, false, false,
+ &buf);
+
+ if (result == ISC_R_NOSPACE) {
+ isc_mem_put(diff->mctx, mem, size);
+ size += 1024;
+ mem = isc_mem_get(diff->mctx, size);
+ goto again;
+ }
+
+ if (result != ISC_R_SUCCESS) {
+ goto cleanup;
+ }
+ /*
+ * Get rid of final newline.
+ */
+ INSIST(buf.used >= 1 &&
+ ((char *)buf.base)[buf.used - 1] == '\n');
+ buf.used--;
+
+ isc_buffer_usedregion(&buf, &r);
+ switch (t->op) {
+ case DNS_DIFFOP_EXISTS:
+ op = "exists";
+ break;
+ case DNS_DIFFOP_ADD:
+ op = "add";
+ break;
+ case DNS_DIFFOP_DEL:
+ op = "del";
+ break;
+ case DNS_DIFFOP_ADDRESIGN:
+ op = "add re-sign";
+ break;
+ case DNS_DIFFOP_DELRESIGN:
+ op = "del re-sign";
+ break;
+ }
+ if (file != NULL) {
+ fprintf(file, "%s %.*s\n", op, (int)r.length,
+ (char *)r.base);
+ } else {
+ isc_log_write(DIFF_COMMON_LOGARGS, ISC_LOG_DEBUG(7),
+ "%s %.*s", op, (int)r.length,
+ (char *)r.base);
+ }
+ }
+ result = ISC_R_SUCCESS;
+cleanup:
+ if (mem != NULL) {
+ isc_mem_put(diff->mctx, mem, size);
+ }
+ return (result);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 03:53:05 +0000