/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC 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. */ /* $Id: diff.c,v 1.4 2020/01/09 13:47:12 florian Exp $ */ /*! \file */ #include <config.h> #include <stdlib.h> #include <isc/buffer.h> #include <isc/file.h> #include <isc/mem.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/result.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, 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); if (t == NULL) return (ISC_R_NOMEMORY); 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; 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); *tp = NULL; } 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_equal(&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(__FILE__, __LINE__, "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; } ENSURE(*tuplep == NULL); } static isc_stdtime_t setresign(dns_rdataset_t *modified) { dns_rdata_t rdata = DNS_RDATA_INIT; dns_rdata_rrsig_t sig; isc_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 isc_result_t diff_apply(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver, isc_boolean_t 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; dns_rdataset_t *modified = NULL; 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, ISC_TRUE, &node)); else CHECK(dns_db_findnsec3node(db, name, ISC_TRUE, &node)); while (t != NULL && dns_name_equal(&t->name, name) && t->op == op && t->rdata.type == type && rdata_covers(&t->rdata) == covers) { 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)); if (t->ttl != rdl.ttl && warn) 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); CHECK(dns_rdatalist_tordataset(&rdl, &rds)); if (rds.type == dns_rdatatype_rrsig) switch (op) { case DNS_DIFFOP_ADDRESIGN: case DNS_DIFFOP_DELRESIGN: modified = &ardataset; dns_rdataset_init(modified); break; default: break; } rds.trust = dns_trust_ultimate; /* * Merge the rdataset into the database. */ switch (op) { case DNS_DIFFOP_ADD: case DNS_DIFFOP_ADDRESIGN: result = dns_db_addrdataset(db, node, ver, 0, &rds, DNS_DBADD_MERGE| DNS_DBADD_EXACT| DNS_DBADD_EXACTTTL, modified); break; case DNS_DIFFOP_DEL: case DNS_DIFFOP_DELRESIGN: result = dns_db_subtractrdataset(db, node, ver, &rds, DNS_DBSUB_EXACT, modified); break; default: INSIST(0); } if (result == ISC_R_SUCCESS) { if (modified != NULL) { isc_stdtime_t resign; resign = setresign(modified); dns_db_setsigningtime(db, modified, resign); } } 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); } } else if (result == DNS_R_NXRRSET) { /* * OK. */ } else { if (modified != NULL && dns_rdataset_isassociated(modified)) dns_rdataset_disassociate(modified); CHECK(result); } dns_db_detachnode(db, &node); if (modified != NULL && dns_rdataset_isassociated(modified)) dns_rdataset_disassociate(modified); } } 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, ISC_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, ISC_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_equal(&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_equal(&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 *)); if (v == NULL) return (ISC_R_NOMEMORY); 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); if (mem == NULL) return (ISC_R_NOMEMORY); 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(__FILE__, __LINE__, "diff_tuple_tordataset failed: %s", dns_result_totext(result)); result = ISC_R_UNEXPECTED; goto cleanup; } again: isc_buffer_init(&buf, mem, size); result = dns_rdataset_totext(&rds, &t->name, ISC_FALSE, ISC_FALSE, &buf); if (result == ISC_R_NOSPACE) { isc_mem_put(diff->mctx, mem, size); size += 1024; mem = isc_mem_get(diff->mctx, size); if (mem == NULL) { result = ISC_R_NOMEMORY; goto cleanup; } 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); }