diff options
Diffstat (limited to 'lib/dns/ssu.c')
-rw-r--r-- | lib/dns/ssu.c | 715 |
1 files changed, 715 insertions, 0 deletions
diff --git a/lib/dns/ssu.c b/lib/dns/ssu.c new file mode 100644 index 0000000..581cdcd --- /dev/null +++ b/lib/dns/ssu.c @@ -0,0 +1,715 @@ +/* + * 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 <stdbool.h> + +#include <isc/magic.h> +#include <isc/mem.h> +#include <isc/netaddr.h> +#include <isc/print.h> +#include <isc/refcount.h> +#include <isc/result.h> +#include <isc/string.h> +#include <isc/util.h> + +#include <dns/dlz.h> +#include <dns/fixedname.h> +#include <dns/name.h> +#include <dns/ssu.h> + +#include <dst/dst.h> +#include <dst/gssapi.h> + +#define SSUTABLEMAGIC ISC_MAGIC('S', 'S', 'U', 'T') +#define VALID_SSUTABLE(table) ISC_MAGIC_VALID(table, SSUTABLEMAGIC) + +#define SSURULEMAGIC ISC_MAGIC('S', 'S', 'U', 'R') +#define VALID_SSURULE(table) ISC_MAGIC_VALID(table, SSURULEMAGIC) + +struct dns_ssurule { + unsigned int magic; + bool grant; /*%< is this a grant or a deny? */ + dns_ssumatchtype_t matchtype; /*%< which type of pattern match? */ + dns_name_t *identity; /*%< the identity to match */ + dns_name_t *name; /*%< the name being updated */ + unsigned int ntypes; /*%< number of data types covered */ + dns_ssuruletype_t *types; /*%< the data types. Can include */ + /* ANY. if NULL, defaults to all */ + /* types except SIG, SOA, and NS */ + ISC_LINK(dns_ssurule_t) link; +}; + +struct dns_ssutable { + unsigned int magic; + isc_mem_t *mctx; + isc_refcount_t references; + dns_dlzdb_t *dlzdatabase; + ISC_LIST(dns_ssurule_t) rules; +}; + +void +dns_ssutable_create(isc_mem_t *mctx, dns_ssutable_t **tablep) { + dns_ssutable_t *table; + + REQUIRE(tablep != NULL && *tablep == NULL); + REQUIRE(mctx != NULL); + + table = isc_mem_get(mctx, sizeof(dns_ssutable_t)); + isc_refcount_init(&table->references, 1); + table->mctx = NULL; + isc_mem_attach(mctx, &table->mctx); + ISC_LIST_INIT(table->rules); + table->magic = SSUTABLEMAGIC; + *tablep = table; +} + +static void +destroy(dns_ssutable_t *table) { + isc_mem_t *mctx; + + REQUIRE(VALID_SSUTABLE(table)); + + mctx = table->mctx; + while (!ISC_LIST_EMPTY(table->rules)) { + dns_ssurule_t *rule = ISC_LIST_HEAD(table->rules); + if (rule->identity != NULL) { + dns_name_free(rule->identity, mctx); + isc_mem_put(mctx, rule->identity, + sizeof(*rule->identity)); + } + if (rule->name != NULL) { + dns_name_free(rule->name, mctx); + isc_mem_put(mctx, rule->name, sizeof(*rule->name)); + } + if (rule->types != NULL) { + isc_mem_put(mctx, rule->types, + rule->ntypes * sizeof(*rule->types)); + } + ISC_LIST_UNLINK(table->rules, rule, link); + rule->magic = 0; + isc_mem_put(mctx, rule, sizeof(dns_ssurule_t)); + } + isc_refcount_destroy(&table->references); + table->magic = 0; + isc_mem_putanddetach(&table->mctx, table, sizeof(dns_ssutable_t)); +} + +void +dns_ssutable_attach(dns_ssutable_t *source, dns_ssutable_t **targetp) { + REQUIRE(VALID_SSUTABLE(source)); + REQUIRE(targetp != NULL && *targetp == NULL); + + isc_refcount_increment(&source->references); + + *targetp = source; +} + +void +dns_ssutable_detach(dns_ssutable_t **tablep) { + dns_ssutable_t *table; + + REQUIRE(tablep != NULL); + table = *tablep; + *tablep = NULL; + REQUIRE(VALID_SSUTABLE(table)); + + if (isc_refcount_decrement(&table->references) == 1) { + destroy(table); + } +} + +void +dns_ssutable_addrule(dns_ssutable_t *table, bool grant, + const dns_name_t *identity, dns_ssumatchtype_t matchtype, + const dns_name_t *name, unsigned int ntypes, + dns_ssuruletype_t *types) { + dns_ssurule_t *rule; + isc_mem_t *mctx; + + REQUIRE(VALID_SSUTABLE(table)); + REQUIRE(dns_name_isabsolute(identity)); + REQUIRE(dns_name_isabsolute(name)); + REQUIRE(matchtype <= dns_ssumatchtype_max); + if (matchtype == dns_ssumatchtype_wildcard) { + REQUIRE(dns_name_iswildcard(name)); + } + if (ntypes > 0) { + REQUIRE(types != NULL); + } + + mctx = table->mctx; + rule = isc_mem_get(mctx, sizeof(*rule)); + + rule->identity = NULL; + rule->name = NULL; + rule->types = NULL; + + rule->grant = grant; + + rule->identity = isc_mem_get(mctx, sizeof(*rule->identity)); + dns_name_init(rule->identity, NULL); + dns_name_dup(identity, mctx, rule->identity); + + rule->name = isc_mem_get(mctx, sizeof(*rule->name)); + dns_name_init(rule->name, NULL); + dns_name_dup(name, mctx, rule->name); + + rule->matchtype = matchtype; + + rule->ntypes = ntypes; + if (ntypes > 0) { + rule->types = isc_mem_get(mctx, ntypes * sizeof(*rule->types)); + memmove(rule->types, types, ntypes * sizeof(*rule->types)); + } else { + rule->types = NULL; + } + + rule->magic = SSURULEMAGIC; + ISC_LIST_INITANDAPPEND(table->rules, rule, link); +} + +static bool +isusertype(dns_rdatatype_t type) { + return (type != dns_rdatatype_ns && type != dns_rdatatype_soa && + type != dns_rdatatype_rrsig); +} + +static void +reverse_from_address(dns_name_t *tcpself, const isc_netaddr_t *tcpaddr) { + char buf[16 * 4 + sizeof("IP6.ARPA.")]; + isc_result_t result; + const unsigned char *ap; + isc_buffer_t b; + unsigned long l; + + switch (tcpaddr->family) { + case AF_INET: + l = ntohl(tcpaddr->type.in.s_addr); + result = snprintf(buf, sizeof(buf), + "%lu.%lu.%lu.%lu.IN-ADDR.ARPA.", + (l >> 0) & 0xff, (l >> 8) & 0xff, + (l >> 16) & 0xff, (l >> 24) & 0xff); + RUNTIME_CHECK(result < sizeof(buf)); + break; + case AF_INET6: + ap = tcpaddr->type.in6.s6_addr; + result = snprintf( + buf, sizeof(buf), + "%x.%x.%x.%x.%x.%x.%x.%x." + "%x.%x.%x.%x.%x.%x.%x.%x." + "%x.%x.%x.%x.%x.%x.%x.%x." + "%x.%x.%x.%x.%x.%x.%x.%x." + "IP6.ARPA.", + ap[15] & 0x0f, (ap[15] >> 4) & 0x0f, ap[14] & 0x0f, + (ap[14] >> 4) & 0x0f, ap[13] & 0x0f, + (ap[13] >> 4) & 0x0f, ap[12] & 0x0f, + (ap[12] >> 4) & 0x0f, ap[11] & 0x0f, + (ap[11] >> 4) & 0x0f, ap[10] & 0x0f, + (ap[10] >> 4) & 0x0f, ap[9] & 0x0f, (ap[9] >> 4) & 0x0f, + ap[8] & 0x0f, (ap[8] >> 4) & 0x0f, ap[7] & 0x0f, + (ap[7] >> 4) & 0x0f, ap[6] & 0x0f, (ap[6] >> 4) & 0x0f, + ap[5] & 0x0f, (ap[5] >> 4) & 0x0f, ap[4] & 0x0f, + (ap[4] >> 4) & 0x0f, ap[3] & 0x0f, (ap[3] >> 4) & 0x0f, + ap[2] & 0x0f, (ap[2] >> 4) & 0x0f, ap[1] & 0x0f, + (ap[1] >> 4) & 0x0f, ap[0] & 0x0f, (ap[0] >> 4) & 0x0f); + RUNTIME_CHECK(result < sizeof(buf)); + break; + default: + UNREACHABLE(); + } + isc_buffer_init(&b, buf, strlen(buf)); + isc_buffer_add(&b, strlen(buf)); + result = dns_name_fromtext(tcpself, &b, dns_rootname, 0, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); +} + +static void +stf_from_address(dns_name_t *stfself, const isc_netaddr_t *tcpaddr) { + char buf[sizeof("X.X.X.X.Y.Y.Y.Y.2.0.0.2.IP6.ARPA.")]; + isc_result_t result; + const unsigned char *ap; + isc_buffer_t b; + unsigned long l; + + switch (tcpaddr->family) { + case AF_INET: + l = ntohl(tcpaddr->type.in.s_addr); + result = snprintf(buf, sizeof(buf), + "%lx.%lx.%lx.%lx.%lx.%lx.%lx.%lx" + "2.0.0.2.IP6.ARPA.", + l & 0xf, (l >> 4) & 0xf, (l >> 8) & 0xf, + (l >> 12) & 0xf, (l >> 16) & 0xf, + (l >> 20) & 0xf, (l >> 24) & 0xf, + (l >> 28) & 0xf); + RUNTIME_CHECK(result < sizeof(buf)); + break; + case AF_INET6: + ap = tcpaddr->type.in6.s6_addr; + result = snprintf( + buf, sizeof(buf), + "%x.%x.%x.%x.%x.%x.%x.%x." + "%x.%x.%x.%x.IP6.ARPA.", + ap[5] & 0x0f, (ap[5] >> 4) & 0x0f, ap[4] & 0x0f, + (ap[4] >> 4) & 0x0f, ap[3] & 0x0f, (ap[3] >> 4) & 0x0f, + ap[2] & 0x0f, (ap[2] >> 4) & 0x0f, ap[1] & 0x0f, + (ap[1] >> 4) & 0x0f, ap[0] & 0x0f, (ap[0] >> 4) & 0x0f); + RUNTIME_CHECK(result < sizeof(buf)); + break; + default: + UNREACHABLE(); + } + isc_buffer_init(&b, buf, strlen(buf)); + isc_buffer_add(&b, strlen(buf)); + result = dns_name_fromtext(stfself, &b, dns_rootname, 0, NULL); + RUNTIME_CHECK(result == ISC_R_SUCCESS); +} + +bool +dns_ssutable_checkrules(dns_ssutable_t *table, const dns_name_t *signer, + const dns_name_t *name, const isc_netaddr_t *addr, + bool tcp, dns_aclenv_t *env, dns_rdatatype_t type, + const dns_name_t *target, const dst_key_t *key, + const dns_ssurule_t **rulep) { + dns_fixedname_t fixed; + dns_name_t *stfself; + dns_name_t *tcpself; + dns_name_t *wildcard; + dns_ssurule_t *rule; + const dns_name_t *tname; + int match; + isc_result_t result; + unsigned int i; + + REQUIRE(VALID_SSUTABLE(table)); + REQUIRE(signer == NULL || dns_name_isabsolute(signer)); + REQUIRE(dns_name_isabsolute(name)); + REQUIRE(addr == NULL || env != NULL); + + if (signer == NULL && addr == NULL) { + return (false); + } + + for (rule = ISC_LIST_HEAD(table->rules); rule != NULL; + rule = ISC_LIST_NEXT(rule, link)) + { + switch (rule->matchtype) { + case dns_ssumatchtype_local: + case dns_ssumatchtype_name: + case dns_ssumatchtype_self: + case dns_ssumatchtype_selfsub: + case dns_ssumatchtype_selfwild: + case dns_ssumatchtype_subdomain: + case dns_ssumatchtype_wildcard: + if (signer == NULL) { + continue; + } + if (dns_name_iswildcard(rule->identity)) { + if (!dns_name_matcheswildcard(signer, + rule->identity)) + { + continue; + } + } else { + if (!dns_name_equal(signer, rule->identity)) { + continue; + } + } + break; + case dns_ssumatchtype_selfkrb5: + case dns_ssumatchtype_selfms: + case dns_ssumatchtype_selfsubkrb5: + case dns_ssumatchtype_selfsubms: + case dns_ssumatchtype_subdomainkrb5: + case dns_ssumatchtype_subdomainms: + case dns_ssumatchtype_subdomainselfkrb5rhs: + case dns_ssumatchtype_subdomainselfmsrhs: + if (signer == NULL) { + continue; + } + break; + case dns_ssumatchtype_tcpself: + case dns_ssumatchtype_6to4self: + if (!tcp || addr == NULL) { + continue; + } + break; + case dns_ssumatchtype_external: + case dns_ssumatchtype_dlz: + break; + } + + switch (rule->matchtype) { + case dns_ssumatchtype_name: + if (!dns_name_equal(name, rule->name)) { + continue; + } + break; + case dns_ssumatchtype_subdomain: + if (!dns_name_issubdomain(name, rule->name)) { + continue; + } + break; + case dns_ssumatchtype_local: + if (addr == NULL) { + continue; + } + if (!dns_name_issubdomain(name, rule->name)) { + continue; + } + RWLOCK(&env->rwlock, isc_rwlocktype_read); + dns_acl_match(addr, NULL, env->localhost, NULL, &match, + NULL); + RWUNLOCK(&env->rwlock, isc_rwlocktype_read); + if (match == 0) { + if (signer != NULL) { + isc_log_write(dns_lctx, + DNS_LOGCATEGORY_GENERAL, + DNS_LOGMODULE_SSU, + ISC_LOG_WARNING, + "update-policy local: " + "match on session " + "key not from " + "localhost"); + } + continue; + } + break; + case dns_ssumatchtype_wildcard: + if (!dns_name_matcheswildcard(name, rule->name)) { + continue; + } + break; + case dns_ssumatchtype_self: + if (!dns_name_equal(signer, name)) { + continue; + } + break; + case dns_ssumatchtype_selfsub: + if (!dns_name_issubdomain(name, signer)) { + continue; + } + break; + case dns_ssumatchtype_selfwild: + wildcard = dns_fixedname_initname(&fixed); + result = dns_name_concatenate(dns_wildcardname, signer, + wildcard, NULL); + if (result != ISC_R_SUCCESS) { + continue; + } + if (!dns_name_matcheswildcard(name, wildcard)) { + continue; + } + break; + case dns_ssumatchtype_selfkrb5: + if (dst_gssapi_identitymatchesrealmkrb5( + signer, name, rule->identity, false)) + { + break; + } + continue; + case dns_ssumatchtype_selfms: + if (dst_gssapi_identitymatchesrealmms( + signer, name, rule->identity, false)) + { + break; + } + continue; + case dns_ssumatchtype_selfsubkrb5: + if (dst_gssapi_identitymatchesrealmkrb5( + signer, name, rule->identity, true)) + { + break; + } + continue; + case dns_ssumatchtype_selfsubms: + if (dst_gssapi_identitymatchesrealmms( + signer, name, rule->identity, true)) + { + break; + } + continue; + case dns_ssumatchtype_subdomainkrb5: + case dns_ssumatchtype_subdomainselfkrb5rhs: + if (!dns_name_issubdomain(name, rule->name)) { + continue; + } + tname = NULL; + switch (rule->matchtype) { + case dns_ssumatchtype_subdomainselfkrb5rhs: + if (type == dns_rdatatype_ptr) { + tname = target; + } + if (type == dns_rdatatype_srv) { + tname = target; + } + break; + default: + break; + } + if (dst_gssapi_identitymatchesrealmkrb5( + signer, tname, rule->identity, false)) + { + break; + } + continue; + case dns_ssumatchtype_subdomainms: + case dns_ssumatchtype_subdomainselfmsrhs: + if (!dns_name_issubdomain(name, rule->name)) { + continue; + } + tname = NULL; + switch (rule->matchtype) { + case dns_ssumatchtype_subdomainselfmsrhs: + if (type == dns_rdatatype_ptr) { + tname = target; + } + if (type == dns_rdatatype_srv) { + tname = target; + } + break; + default: + break; + } + if (dst_gssapi_identitymatchesrealmms( + signer, tname, rule->identity, false)) + { + break; + } + continue; + case dns_ssumatchtype_tcpself: + tcpself = dns_fixedname_initname(&fixed); + reverse_from_address(tcpself, addr); + if (dns_name_iswildcard(rule->identity)) { + if (!dns_name_matcheswildcard(tcpself, + rule->identity)) + { + continue; + } + } else { + if (!dns_name_equal(tcpself, rule->identity)) { + continue; + } + } + if (!dns_name_equal(tcpself, name)) { + continue; + } + break; + case dns_ssumatchtype_6to4self: + stfself = dns_fixedname_initname(&fixed); + stf_from_address(stfself, addr); + if (dns_name_iswildcard(rule->identity)) { + if (!dns_name_matcheswildcard(stfself, + rule->identity)) + { + continue; + } + } else { + if (!dns_name_equal(stfself, rule->identity)) { + continue; + } + } + if (!dns_name_equal(stfself, name)) { + continue; + } + break; + case dns_ssumatchtype_external: + if (!dns_ssu_external_match(rule->identity, signer, + name, addr, type, key, + table->mctx)) + { + continue; + } + break; + case dns_ssumatchtype_dlz: + if (!dns_dlz_ssumatch(table->dlzdatabase, signer, name, + addr, type, key)) + { + continue; + } + break; + } + + if (rule->ntypes == 0) { + /* + * If this is a DLZ rule, then the DLZ ssu + * checks will have already checked the type. + */ + if (rule->matchtype != dns_ssumatchtype_dlz && + !isusertype(type)) + { + continue; + } + } else { + for (i = 0; i < rule->ntypes; i++) { + if (rule->types[i].type == dns_rdatatype_any || + rule->types[i].type == type) + { + break; + } + } + if (i == rule->ntypes) { + continue; + } + } + if (rule->grant && rulep != NULL) { + *rulep = rule; + } + return (rule->grant); + } + + return (false); +} + +bool +dns_ssurule_isgrant(const dns_ssurule_t *rule) { + REQUIRE(VALID_SSURULE(rule)); + return (rule->grant); +} + +dns_name_t * +dns_ssurule_identity(const dns_ssurule_t *rule) { + REQUIRE(VALID_SSURULE(rule)); + return (rule->identity); +} + +unsigned int +dns_ssurule_matchtype(const dns_ssurule_t *rule) { + REQUIRE(VALID_SSURULE(rule)); + return (rule->matchtype); +} + +dns_name_t * +dns_ssurule_name(const dns_ssurule_t *rule) { + REQUIRE(VALID_SSURULE(rule)); + return (rule->name); +} + +unsigned int +dns_ssurule_types(const dns_ssurule_t *rule, dns_ssuruletype_t **types) { + REQUIRE(VALID_SSURULE(rule)); + REQUIRE(types != NULL && *types != NULL); + *types = rule->types; + return (rule->ntypes); +} + +unsigned int +dns_ssurule_max(const dns_ssurule_t *rule, dns_rdatatype_t type) { + unsigned int i; + unsigned int max = 0; + + REQUIRE(VALID_SSURULE(rule)); + + for (i = 0; i < rule->ntypes; i++) { + if (rule->types[i].type == dns_rdatatype_any) { + max = rule->types[i].max; + } + if (rule->types[i].type == type) { + return (rule->types[i].max); + } + } + return (max); +} + +isc_result_t +dns_ssutable_firstrule(const dns_ssutable_t *table, dns_ssurule_t **rule) { + REQUIRE(VALID_SSUTABLE(table)); + REQUIRE(rule != NULL && *rule == NULL); + *rule = ISC_LIST_HEAD(table->rules); + return (*rule != NULL ? ISC_R_SUCCESS : ISC_R_NOMORE); +} + +isc_result_t +dns_ssutable_nextrule(dns_ssurule_t *rule, dns_ssurule_t **nextrule) { + REQUIRE(VALID_SSURULE(rule)); + REQUIRE(nextrule != NULL && *nextrule == NULL); + *nextrule = ISC_LIST_NEXT(rule, link); + return (*nextrule != NULL ? ISC_R_SUCCESS : ISC_R_NOMORE); +} + +/* + * Create a specialised SSU table that points at an external DLZ database + */ +void +dns_ssutable_createdlz(isc_mem_t *mctx, dns_ssutable_t **tablep, + dns_dlzdb_t *dlzdatabase) { + dns_ssurule_t *rule; + dns_ssutable_t *table = NULL; + + REQUIRE(tablep != NULL && *tablep == NULL); + + dns_ssutable_create(mctx, &table); + + table->dlzdatabase = dlzdatabase; + + rule = isc_mem_get(table->mctx, sizeof(dns_ssurule_t)); + + rule->identity = NULL; + rule->name = NULL; + rule->grant = true; + rule->matchtype = dns_ssumatchtype_dlz; + rule->ntypes = 0; + rule->types = NULL; + rule->magic = SSURULEMAGIC; + + ISC_LIST_INITANDAPPEND(table->rules, rule, link); + *tablep = table; +} + +isc_result_t +dns_ssu_mtypefromstring(const char *str, dns_ssumatchtype_t *mtype) { + REQUIRE(str != NULL); + REQUIRE(mtype != NULL); + + if (strcasecmp(str, "name") == 0) { + *mtype = dns_ssumatchtype_name; + } else if (strcasecmp(str, "subdomain") == 0) { + *mtype = dns_ssumatchtype_subdomain; + } else if (strcasecmp(str, "wildcard") == 0) { + *mtype = dns_ssumatchtype_wildcard; + } else if (strcasecmp(str, "self") == 0) { + *mtype = dns_ssumatchtype_self; + } else if (strcasecmp(str, "selfsub") == 0) { + *mtype = dns_ssumatchtype_selfsub; + } else if (strcasecmp(str, "selfwild") == 0) { + *mtype = dns_ssumatchtype_selfwild; + } else if (strcasecmp(str, "ms-self") == 0) { + *mtype = dns_ssumatchtype_selfms; + } else if (strcasecmp(str, "ms-selfsub") == 0) { + *mtype = dns_ssumatchtype_selfsubms; + } else if (strcasecmp(str, "krb5-self") == 0) { + *mtype = dns_ssumatchtype_selfkrb5; + } else if (strcasecmp(str, "krb5-selfsub") == 0) { + *mtype = dns_ssumatchtype_selfsubkrb5; + } else if (strcasecmp(str, "ms-subdomain") == 0) { + *mtype = dns_ssumatchtype_subdomainms; + } else if (strcasecmp(str, "ms-subdomain-self-rhs") == 0) { + *mtype = dns_ssumatchtype_subdomainselfmsrhs; + } else if (strcasecmp(str, "krb5-subdomain") == 0) { + *mtype = dns_ssumatchtype_subdomainkrb5; + } else if (strcasecmp(str, "krb5-subdomain-self-rhs") == 0) { + *mtype = dns_ssumatchtype_subdomainselfkrb5rhs; + } else if (strcasecmp(str, "tcp-self") == 0) { + *mtype = dns_ssumatchtype_tcpself; + } else if (strcasecmp(str, "6to4-self") == 0) { + *mtype = dns_ssumatchtype_6to4self; + } else if (strcasecmp(str, "zonesub") == 0) { + *mtype = dns_ssumatchtype_subdomain; + } else if (strcasecmp(str, "external") == 0) { + *mtype = dns_ssumatchtype_external; + } else { + return (ISC_R_NOTFOUND); + } + return (ISC_R_SUCCESS); +} |