diff options
Diffstat (limited to 'lib/dns/diff.c')
| -rw-r--r-- | lib/dns/diff.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/lib/dns/diff.c b/lib/dns/diff.c new file mode 100644 index 0000000..850ca91 --- /dev/null +++ b/lib/dns/diff.c @@ -0,0 +1,638 @@ +/* + * Copyright (C) 2004, 2005, 2007, 2008 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 2000-2003 Internet Software Consortium. + * + * 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 1.18 2008/09/24 02:46:22 marka 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> + +#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 = mctx; + t->op = op; + + datap = (unsigned char *)(t + 1); + + memcpy(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; + + memcpy(datap, rdata->data, rdata->length); + dns_rdata_init(&t->rdata); + dns_rdata_clone(rdata, &t->rdata); + t->rdata.data = datap; + datap += rdata->length; + + 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; + REQUIRE(DNS_DIFFTUPLE_VALID(t)); + dns_name_invalidate(&t->name); + t->magic = 0; + isc_mem_free(t->mctx, t); + *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; + diff->resign = 0; + 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, isc_uint32_t delta) { + dns_rdata_t rdata = DNS_RDATA_INIT; + dns_rdata_rrsig_t sig; + isc_stdtime_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 = sig.timeexpire - delta; + 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 || sig.timeexpire - delta < when) + when = sig.timeexpire - delta; + next_rr: + dns_rdata_reset(&rdata); + result = dns_rdataset_next(modified); + } + INSIST(result == ISC_R_NOMORE); + return (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; + isc_boolean_t offline; + + 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. + */ + + rdl.type = type; + rdl.covers = covers; + rdl.rdclass = t->rdata.rdclass; + rdl.ttl = t->ttl; + ISC_LIST_INIT(rdl.rdata); + ISC_LINK_INIT(&rdl, link); + + 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)); + + offline = ISC_FALSE; + 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); + if (t->rdata.flags & DNS_RDATA_OFFLINE) + offline = ISC_TRUE; + 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, + diff->resign); + 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) + isc_log_write(DIFF_COMMON_LOGARGS, + ISC_LOG_WARNING, + "update with no effect"); + } 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); + + rdl.type = type; + rdl.covers = covers; + rdl.rdclass = t->rdata.rdclass; + rdl.ttl = t->ttl; + ISC_LIST_INIT(rdl.rdata); + ISC_LINK_INIT(&rdl, link); + + 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, + "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); + i = 0; + 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 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); + + rdl->type = t->rdata.type; + rdl->rdclass = t->rdata.rdclass; + rdl->ttl = t->ttl; + ISC_LIST_INIT(rdl->rdata); + ISC_LINK_INIT(rdl, link); + 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); +} |