diff options
Diffstat (limited to 'source4/dns_server/dlz_bind9.c')
| -rw-r--r-- | source4/dns_server/dlz_bind9.c | 2219 |
1 files changed, 2219 insertions, 0 deletions
diff --git a/source4/dns_server/dlz_bind9.c b/source4/dns_server/dlz_bind9.c new file mode 100644 index 0000000..7b73abd --- /dev/null +++ b/source4/dns_server/dlz_bind9.c @@ -0,0 +1,2219 @@ +/* + Unix SMB/CIFS implementation. + + bind9 dlz driver for Samba + + Copyright (C) 2010 Andrew Tridgell + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "talloc.h" +#include "param/param.h" +#include "lib/events/events.h" +#include "dsdb/samdb/samdb.h" +#include "dsdb/common/util.h" +#include "auth/auth.h" +#include "auth/session.h" +#include "auth/gensec/gensec.h" +#include "librpc/gen_ndr/security.h" +#include "auth/credentials/credentials.h" +#include "system/kerberos.h" +#include "auth/kerberos/kerberos.h" +#include "gen_ndr/ndr_dnsp.h" +#include "gen_ndr/server_id.h" +#include "messaging/messaging.h" +#include <popt.h> +#include "lib/util/dlinklist.h" +#include "dlz_minimal.h" +#include "dnsserver_common.h" +#include "lib/util/smb_strtox.h" +#include "lib/util/access.h" + +#undef strcasecmp + +struct b9_options { + const char *url; + const char *debug; +}; + +struct b9_zone { + char *name; + struct b9_zone *prev, *next; +}; + +struct dlz_bind9_data { + struct b9_options options; + struct ldb_context *samdb; + struct tevent_context *ev_ctx; + struct loadparm_context *lp; + int *transaction_token; + uint32_t soa_serial; + struct b9_zone *zonelist; + + /* Used for dynamic update */ + struct smb_krb5_context *smb_krb5_ctx; + struct auth4_context *auth_context; + struct auth_session_info *session_info; + char *update_name; + + /* helper functions from the dlz_dlopen driver */ + log_t *log; + dns_sdlz_putrr_t *putrr; + dns_sdlz_putnamedrr_t *putnamedrr; + dns_dlz_writeablezone_t *writeable_zone; +}; + +static struct dlz_bind9_data *dlz_bind9_state = NULL; +static int dlz_bind9_state_ref_count = 0; + +static const char *zone_prefixes[] = { + "CN=MicrosoftDNS,DC=DomainDnsZones", + "CN=MicrosoftDNS,DC=ForestDnsZones", + "CN=MicrosoftDNS,CN=System", + NULL +}; + +/* + * Get a printable string representation of an isc_result_t + */ +static const char *isc_result_str( const isc_result_t result) { + switch (result) { + case ISC_R_SUCCESS: + return "ISC_R_SUCCESS"; + case ISC_R_NOMEMORY: + return "ISC_R_NOMEMORY"; + case ISC_R_NOPERM: + return "ISC_R_NOPERM"; + case ISC_R_NOSPACE: + return "ISC_R_NOSPACE"; + case ISC_R_NOTFOUND: + return "ISC_R_NOTFOUND"; + case ISC_R_FAILURE: + return "ISC_R_FAILURE"; + case ISC_R_NOTIMPLEMENTED: + return "ISC_R_NOTIMPLEMENTED"; + case ISC_R_NOMORE: + return "ISC_R_NOMORE"; + case ISC_R_INVALIDFILE: + return "ISC_R_INVALIDFILE"; + case ISC_R_UNEXPECTED: + return "ISC_R_UNEXPECTED"; + case ISC_R_FILENOTFOUND: + return "ISC_R_FILENOTFOUND"; + default: + return "UNKNOWN"; + } +} + +/* + return the version of the API + */ +_PUBLIC_ int dlz_version(unsigned int *flags) +{ + return DLZ_DLOPEN_VERSION; +} + +/* + remember a helper function from the bind9 dlz_dlopen driver + */ +static void b9_add_helper(struct dlz_bind9_data *state, const char *helper_name, void *ptr) +{ + if (strcmp(helper_name, "log") == 0) { + state->log = ptr; + } + if (strcmp(helper_name, "putrr") == 0) { + state->putrr = ptr; + } + if (strcmp(helper_name, "putnamedrr") == 0) { + state->putnamedrr = ptr; + } + if (strcmp(helper_name, "writeable_zone") == 0) { + state->writeable_zone = ptr; + } +} + +/* + * Add a trailing '.' if it's missing + */ +static const char *b9_format_fqdn(TALLOC_CTX *mem_ctx, const char *str) +{ + size_t len; + const char *tmp; + + if (str == NULL || str[0] == '\0') { + return str; + } + + len = strlen(str); + if (str[len-1] != '.') { + tmp = talloc_asprintf(mem_ctx, "%s.", str); + } else { + tmp = str; + } + return tmp; +} + +/* + * Format a record for bind9. + * + * On failure/error returns false, OR sets *data to NULL. + * Callers should check for both! + */ +static bool b9_format(struct dlz_bind9_data *state, + TALLOC_CTX *mem_ctx, + struct dnsp_DnssrvRpcRecord *rec, + const char **type, const char **data) +{ + uint32_t i; + char *tmp; + const char *fqdn; + + switch (rec->wType) { + case DNS_TYPE_A: + *type = "a"; + *data = rec->data.ipv4; + break; + + case DNS_TYPE_AAAA: + *type = "aaaa"; + *data = rec->data.ipv6; + break; + + case DNS_TYPE_CNAME: + *type = "cname"; + *data = b9_format_fqdn(mem_ctx, rec->data.cname); + break; + + case DNS_TYPE_TXT: + *type = "txt"; + tmp = talloc_asprintf(mem_ctx, "\"%s\"", rec->data.txt.str[0]); + for (i=1; i<rec->data.txt.count; i++) { + tmp = talloc_asprintf_append(tmp, " \"%s\"", rec->data.txt.str[i]); + } + *data = tmp; + break; + + case DNS_TYPE_PTR: + *type = "ptr"; + *data = b9_format_fqdn(mem_ctx, rec->data.ptr); + break; + + case DNS_TYPE_SRV: + *type = "srv"; + fqdn = b9_format_fqdn(mem_ctx, rec->data.srv.nameTarget); + if (fqdn == NULL) { + return false; + } + *data = talloc_asprintf(mem_ctx, "%u %u %u %s", + rec->data.srv.wPriority, + rec->data.srv.wWeight, + rec->data.srv.wPort, + fqdn); + break; + + case DNS_TYPE_MX: + *type = "mx"; + fqdn = b9_format_fqdn(mem_ctx, rec->data.mx.nameTarget); + if (fqdn == NULL) { + return false; + } + *data = talloc_asprintf(mem_ctx, "%u %s", + rec->data.mx.wPriority, fqdn); + break; + + case DNS_TYPE_NS: + *type = "ns"; + *data = b9_format_fqdn(mem_ctx, rec->data.ns); + break; + + case DNS_TYPE_SOA: { + const char *mname; + *type = "soa"; + + /* we need to fake the authoritative nameserver to + * point at ourselves. This is how AD DNS servers + * force clients to send updates to the right local DC + */ + mname = talloc_asprintf(mem_ctx, "%s.%s.", + lpcfg_netbios_name(state->lp), + lpcfg_dnsdomain(state->lp)); + if (mname == NULL) { + return false; + } + mname = strlower_talloc(mem_ctx, mname); + if (mname == NULL) { + return false; + } + + fqdn = b9_format_fqdn(mem_ctx, rec->data.soa.rname); + if (fqdn == NULL) { + return false; + } + + state->soa_serial = rec->data.soa.serial; + + *data = talloc_asprintf(mem_ctx, "%s %s %u %u %u %u %u", + mname, fqdn, + rec->data.soa.serial, + rec->data.soa.refresh, + rec->data.soa.retry, + rec->data.soa.expire, + rec->data.soa.minimum); + break; + } + + default: + state->log(ISC_LOG_ERROR, "samba_dlz b9_format: unhandled record type %u", + rec->wType); + return false; + } + + return true; +} + +static const struct { + enum dns_record_type dns_type; + const char *typestr; + bool single_valued; +} dns_typemap[] = { + { DNS_TYPE_A, "A" , false}, + { DNS_TYPE_AAAA, "AAAA" , false}, + { DNS_TYPE_CNAME, "CNAME" , true}, + { DNS_TYPE_TXT, "TXT" , false}, + { DNS_TYPE_PTR, "PTR" , false}, + { DNS_TYPE_SRV, "SRV" , false}, + { DNS_TYPE_MX, "MX" , false}, + { DNS_TYPE_NS, "NS" , false}, + { DNS_TYPE_SOA, "SOA" , true}, +}; + + +/* + see if a DNS type is single valued + */ +static bool b9_single_valued(enum dns_record_type dns_type) +{ + int i; + for (i=0; i<ARRAY_SIZE(dns_typemap); i++) { + if (dns_typemap[i].dns_type == dns_type) { + return dns_typemap[i].single_valued; + } + } + return false; +} + +/* + get a DNS_TYPE_* value from the corresponding string + */ +static bool b9_dns_type(const char *type, enum dns_record_type *dtype) +{ + int i; + for (i=0; i<ARRAY_SIZE(dns_typemap); i++) { + if (strcasecmp(dns_typemap[i].typestr, type) == 0) { + *dtype = dns_typemap[i].dns_type; + return true; + } + } + return false; +} + + +#define DNS_PARSE_STR(ret, str, sep, saveptr) do { \ + (ret) = strtok_r(str, sep, &saveptr); \ + if ((ret) == NULL) return false; \ + } while (0) + +#define DNS_PARSE_UINT(ret, str, sep, saveptr) do { \ + char *istr = strtok_r(str, sep, &saveptr); \ + int error = 0;\ + if ((istr) == NULL) return false; \ + (ret) = smb_strtoul(istr, NULL, 10, &error, SMB_STR_STANDARD); \ + if (error != 0) {\ + return false;\ + }\ + } while (0) + +/* + parse a record from bind9 + */ +static bool b9_parse(struct dlz_bind9_data *state, + const char *rdatastr, + struct dnsp_DnssrvRpcRecord *rec) +{ + char *full_name, *dclass, *type; + char *str, *tmp, *saveptr=NULL; + int i; + + str = talloc_strdup(rec, rdatastr); + if (str == NULL) { + return false; + } + + /* parse the SDLZ string form */ + DNS_PARSE_STR(full_name, str, "\t", saveptr); + DNS_PARSE_UINT(rec->dwTtlSeconds, NULL, "\t", saveptr); + DNS_PARSE_STR(dclass, NULL, "\t", saveptr); + DNS_PARSE_STR(type, NULL, "\t", saveptr); + + /* construct the record */ + for (i=0; i<ARRAY_SIZE(dns_typemap); i++) { + if (strcasecmp(type, dns_typemap[i].typestr) == 0) { + rec->wType = dns_typemap[i].dns_type; + break; + } + } + if (i == ARRAY_SIZE(dns_typemap)) { + state->log(ISC_LOG_ERROR, "samba_dlz: unsupported record type '%s' for '%s'", + type, full_name); + return false; + } + + switch (rec->wType) { + case DNS_TYPE_A: + DNS_PARSE_STR(rec->data.ipv4, NULL, " ", saveptr); + break; + + case DNS_TYPE_AAAA: + DNS_PARSE_STR(rec->data.ipv6, NULL, " ", saveptr); + break; + + case DNS_TYPE_CNAME: + DNS_PARSE_STR(rec->data.cname, NULL, " ", saveptr); + break; + + case DNS_TYPE_TXT: + rec->data.txt.count = 0; + rec->data.txt.str = talloc_array(rec, const char *, rec->data.txt.count); + tmp = strtok_r(NULL, "\t", &saveptr); + while (tmp) { + rec->data.txt.str = talloc_realloc(rec, rec->data.txt.str, const char *, + rec->data.txt.count+1); + if (tmp[0] == '"') { + /* Strip quotes */ + rec->data.txt.str[rec->data.txt.count] = talloc_strndup(rec, &tmp[1], strlen(tmp)-2); + } else { + rec->data.txt.str[rec->data.txt.count] = talloc_strdup(rec, tmp); + } + rec->data.txt.count++; + tmp = strtok_r(NULL, " ", &saveptr); + } + break; + + case DNS_TYPE_PTR: + DNS_PARSE_STR(rec->data.ptr, NULL, " ", saveptr); + break; + + case DNS_TYPE_SRV: + DNS_PARSE_UINT(rec->data.srv.wPriority, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.srv.wWeight, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.srv.wPort, NULL, " ", saveptr); + DNS_PARSE_STR(rec->data.srv.nameTarget, NULL, " ", saveptr); + break; + + case DNS_TYPE_MX: + DNS_PARSE_UINT(rec->data.mx.wPriority, NULL, " ", saveptr); + DNS_PARSE_STR(rec->data.mx.nameTarget, NULL, " ", saveptr); + break; + + case DNS_TYPE_NS: + DNS_PARSE_STR(rec->data.ns, NULL, " ", saveptr); + break; + + case DNS_TYPE_SOA: + DNS_PARSE_STR(rec->data.soa.mname, NULL, " ", saveptr); + DNS_PARSE_STR(rec->data.soa.rname, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.soa.serial, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.soa.refresh, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.soa.retry, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.soa.expire, NULL, " ", saveptr); + DNS_PARSE_UINT(rec->data.soa.minimum, NULL, " ", saveptr); + break; + + default: + state->log(ISC_LOG_ERROR, "samba_dlz b9_parse: unhandled record type %u", + rec->wType); + return false; + } + + /* we should be at the end of the buffer now */ + if (strtok_r(NULL, "\t ", &saveptr) != NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz b9_parse: unexpected data at end of string for '%s'", + rdatastr); + return false; + } + + return true; +} + +/* + send a resource record to bind9 + */ +static isc_result_t b9_putrr(struct dlz_bind9_data *state, + void *handle, struct dnsp_DnssrvRpcRecord *rec, + const char **types) +{ + isc_result_t result; + const char *type, *data; + TALLOC_CTX *tmp_ctx = talloc_new(state); + + if (!b9_format(state, tmp_ctx, rec, &type, &data)) { + return ISC_R_FAILURE; + } + + if (data == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + if (types) { + int i; + for (i=0; types[i]; i++) { + if (strcmp(types[i], type) == 0) break; + } + if (types[i] == NULL) { + /* skip it */ + return ISC_R_SUCCESS; + } + } + + result = state->putrr(handle, type, rec->dwTtlSeconds, data); + if (result != ISC_R_SUCCESS) { + state->log(ISC_LOG_ERROR, "Failed to put rr"); + } + talloc_free(tmp_ctx); + return result; +} + + +/* + send a named resource record to bind9 + */ +static isc_result_t b9_putnamedrr(struct dlz_bind9_data *state, + void *handle, const char *name, + struct dnsp_DnssrvRpcRecord *rec) +{ + isc_result_t result; + const char *type, *data; + TALLOC_CTX *tmp_ctx = talloc_new(state); + + if (!b9_format(state, tmp_ctx, rec, &type, &data)) { + return ISC_R_FAILURE; + } + + if (data == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + result = state->putnamedrr(handle, name, type, rec->dwTtlSeconds, data); + if (result != ISC_R_SUCCESS) { + state->log(ISC_LOG_ERROR, "Failed to put named rr '%s'", name); + } + talloc_free(tmp_ctx); + return result; +} + +/* + parse options + */ +static isc_result_t parse_options(struct dlz_bind9_data *state, + unsigned int argc, const char **argv, + struct b9_options *options) +{ + int opt; + poptContext pc; + struct poptOption long_options[] = { + { "url", 'H', POPT_ARG_STRING, &options->url, 0, "database URL", "URL" }, + { "debug", 'd', POPT_ARG_STRING, &options->debug, 0, "debug level", "DEBUG" }, + {0} + }; + + pc = poptGetContext("dlz_bind9", argc, argv, long_options, + POPT_CONTEXT_KEEP_FIRST); + while ((opt = poptGetNextOpt(pc)) != -1) { + switch (opt) { + default: + state->log(ISC_LOG_ERROR, "dlz_bind9: Invalid option %s: %s", + poptBadOption(pc, 0), poptStrerror(opt)); + poptFreeContext(pc); + return ISC_R_FAILURE; + } + } + + poptFreeContext(pc); + return ISC_R_SUCCESS; +} + + +/* + * Create session info from PAC + * This is called as auth_context->generate_session_info_pac() + */ +static NTSTATUS b9_generate_session_info_pac(struct auth4_context *auth_context, + TALLOC_CTX *mem_ctx, + struct smb_krb5_context *smb_krb5_context, + DATA_BLOB *pac_blob, + const char *principal_name, + const struct tsocket_address *remote_addr, + uint32_t session_info_flags, + struct auth_session_info **session_info) +{ + NTSTATUS status; + struct auth_user_info_dc *user_info_dc; + TALLOC_CTX *tmp_ctx; + + tmp_ctx = talloc_new(mem_ctx); + NT_STATUS_HAVE_NO_MEMORY(tmp_ctx); + + status = kerberos_pac_blob_to_user_info_dc(tmp_ctx, + *pac_blob, + smb_krb5_context->krb5_context, + &user_info_dc, + NULL, + NULL); + if (!NT_STATUS_IS_OK(status)) { + talloc_free(tmp_ctx); + return status; + } + + if (user_info_dc->info->authenticated) { + session_info_flags |= AUTH_SESSION_INFO_AUTHENTICATED; + } + + session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES; + + status = auth_generate_session_info(mem_ctx, NULL, NULL, user_info_dc, + session_info_flags, session_info); + if (!NT_STATUS_IS_OK(status)) { + talloc_free(tmp_ctx); + return status; + } + + talloc_free(tmp_ctx); + return status; +} + +/* Callback for the DEBUG() system, to catch the remaining messages */ +static void b9_debug(void *private_ptr, int msg_level, const char *msg) +{ + static const int isc_log_map[] = { + ISC_LOG_CRITICAL, /* 0 */ + ISC_LOG_ERROR, /* 1 */ + ISC_LOG_WARNING, /* 2 */ + ISC_LOG_NOTICE /* 3 */ + }; + struct dlz_bind9_data *state = private_ptr; + int isc_log_level; + + if (msg_level >= ARRAY_SIZE(isc_log_map) || msg_level < 0) { + isc_log_level = ISC_LOG_INFO; + } else { + isc_log_level = isc_log_map[msg_level]; + } + state->log(isc_log_level, "samba_dlz: %s", msg); +} + +static int dlz_state_debug_unregister(struct dlz_bind9_data *state) +{ + /* Stop logging (to the bind9 logs) */ + debug_set_callback(NULL, NULL); + return 0; +} + +/* + called to initialise the driver + */ +_PUBLIC_ isc_result_t dlz_create(const char *dlzname, + unsigned int argc, const char **argv, + void **dbdata, ...) +{ + struct dlz_bind9_data *state; + const char *helper_name; + va_list ap; + isc_result_t result; + struct ldb_dn *dn; + NTSTATUS nt_status; + int ret; + char *errstring = NULL; + + if (dlz_bind9_state != NULL) { + dlz_bind9_state->log(ISC_LOG_ERROR, + "samba_dlz: dlz_create ignored, #refs=%d", + dlz_bind9_state_ref_count); + *dbdata = dlz_bind9_state; + dlz_bind9_state_ref_count++; + return ISC_R_SUCCESS; + } + + state = talloc_zero(NULL, struct dlz_bind9_data); + if (state == NULL) { + return ISC_R_NOMEMORY; + } + + talloc_set_destructor(state, dlz_state_debug_unregister); + + /* fill in the helper functions */ + va_start(ap, dbdata); + while ((helper_name = va_arg(ap, const char *)) != NULL) { + b9_add_helper(state, helper_name, va_arg(ap, void*)); + } + va_end(ap); + + /* Do not install samba signal handlers */ + fault_setup_disable(); + + /* Start logging (to the bind9 logs) */ + debug_set_callback(state, b9_debug); + + state->ev_ctx = s4_event_context_init(state); + if (state->ev_ctx == NULL) { + result = ISC_R_NOMEMORY; + goto failed; + } + + result = parse_options(state, argc, argv, &state->options); + if (result != ISC_R_SUCCESS) { + goto failed; + } + + state->lp = loadparm_init_global(true); + if (state->lp == NULL) { + result = ISC_R_NOMEMORY; + goto failed; + } + + if (state->options.debug) { + lpcfg_do_global_parameter(state->lp, "log level", state->options.debug); + } else { + lpcfg_do_global_parameter(state->lp, "log level", "0"); + } + + if (smb_krb5_init_context(state, state->lp, &state->smb_krb5_ctx) != 0) { + result = ISC_R_NOMEMORY; + goto failed; + } + + nt_status = gensec_init(); + if (!NT_STATUS_IS_OK(nt_status)) { + result = ISC_R_NOMEMORY; + goto failed; + } + + state->auth_context = talloc_zero(state, struct auth4_context); + if (state->auth_context == NULL) { + result = ISC_R_NOMEMORY; + goto failed; + } + + if (state->options.url == NULL) { + state->options.url = talloc_asprintf(state, + "%s/dns/sam.ldb", + lpcfg_binddns_dir(state->lp)); + if (state->options.url == NULL) { + result = ISC_R_NOMEMORY; + goto failed; + } + + if (!file_exist(state->options.url)) { + state->options.url = talloc_asprintf(state, + "%s/dns/sam.ldb", + lpcfg_private_dir(state->lp)); + if (state->options.url == NULL) { + result = ISC_R_NOMEMORY; + goto failed; + } + } + } + + ret = samdb_connect_url(state, + state->ev_ctx, + state->lp, + system_session(state->lp), + 0, + state->options.url, + NULL, + &state->samdb, + &errstring); + if (ret != LDB_SUCCESS) { + state->log(ISC_LOG_ERROR, + "samba_dlz: Failed to connect to %s: %s", + errstring, ldb_strerror(ret)); + result = ISC_R_FAILURE; + goto failed; + } + + dn = ldb_get_default_basedn(state->samdb); + if (dn == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: Unable to get basedn for %s - %s", + state->options.url, ldb_errstring(state->samdb)); + result = ISC_R_FAILURE; + goto failed; + } + + state->log(ISC_LOG_INFO, "samba_dlz: started for DN %s", + ldb_dn_get_linearized(dn)); + + state->auth_context->event_ctx = state->ev_ctx; + state->auth_context->lp_ctx = state->lp; + state->auth_context->sam_ctx = state->samdb; + state->auth_context->generate_session_info_pac = b9_generate_session_info_pac; + + *dbdata = state; + dlz_bind9_state = state; + dlz_bind9_state_ref_count++; + + return ISC_R_SUCCESS; + +failed: + state->log(ISC_LOG_INFO, + "samba_dlz: FAILED dlz_create call result=%d #refs=%d", + result, + dlz_bind9_state_ref_count); + talloc_free(state); + return result; +} + +/* + shutdown the backend + */ +_PUBLIC_ void dlz_destroy(void *dbdata) +{ + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + + dlz_bind9_state_ref_count--; + if (dlz_bind9_state_ref_count == 0) { + state->log(ISC_LOG_INFO, "samba_dlz: shutting down"); + talloc_unlink(state, state->samdb); + talloc_free(state); + dlz_bind9_state = NULL; + } else { + state->log(ISC_LOG_INFO, + "samba_dlz: dlz_destroy called. %d refs remaining.", + dlz_bind9_state_ref_count); + } +} + + +/* + return the base DN for a zone + */ +static isc_result_t b9_find_zone_dn(struct dlz_bind9_data *state, const char *zone_name, + TALLOC_CTX *mem_ctx, struct ldb_dn **zone_dn) +{ + int ret; + TALLOC_CTX *tmp_ctx = talloc_new(state); + const char *attrs[] = { NULL }; + int i; + + for (i=0; zone_prefixes[i]; i++) { + const char *casefold; + struct ldb_dn *dn; + struct ldb_result *res; + struct ldb_val zone_name_val + = data_blob_string_const(zone_name); + + dn = ldb_dn_copy(tmp_ctx, ldb_get_default_basedn(state->samdb)); + if (dn == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + /* + * This dance ensures that it is not possible to put + * (eg) an extra DC=x, into the DNS name being + * queried + */ + + if (!ldb_dn_add_child_fmt(dn, + "DC=X,%s", + zone_prefixes[i])) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + ret = ldb_dn_set_component(dn, + 0, + "DC", + zone_name_val); + if (ret != LDB_SUCCESS) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + /* + * Check if this is a plausibly valid DN early + * (time spent here will be saved during the + * search due to an internal cache) + */ + casefold = ldb_dn_get_casefold(dn); + + if (casefold == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOTFOUND; + } + + ret = ldb_search(state->samdb, tmp_ctx, &res, dn, LDB_SCOPE_BASE, attrs, "objectClass=dnsZone"); + if (ret == LDB_SUCCESS) { + if (zone_dn != NULL) { + *zone_dn = talloc_steal(mem_ctx, dn); + } + talloc_free(tmp_ctx); + return ISC_R_SUCCESS; + } + talloc_free(dn); + } + + talloc_free(tmp_ctx); + return ISC_R_NOTFOUND; +} + + +/* + return the DN for a name. The record does not need to exist, but the + zone must exist + */ +static isc_result_t b9_find_name_dn(struct dlz_bind9_data *state, const char *name, + TALLOC_CTX *mem_ctx, struct ldb_dn **dn) +{ + const char *p; + + /* work through the name piece by piece, until we find a zone */ + for (p=name; p; ) { + isc_result_t result; + result = b9_find_zone_dn(state, p, mem_ctx, dn); + if (result == ISC_R_SUCCESS) { + const char *casefold; + + /* we found a zone, now extend the DN to get + * the full DN + */ + bool ret; + if (p == name) { + ret = ldb_dn_add_child_fmt(*dn, "DC=@"); + if (ret == false) { + talloc_free(*dn); + return ISC_R_NOMEMORY; + } + } else { + struct ldb_val name_val + = data_blob_const(name, + (int)(p-name)-1); + + if (!ldb_dn_add_child_val(*dn, + "DC", + name_val)) { + talloc_free(*dn); + return ISC_R_NOMEMORY; + } + } + + /* + * Check if this is a plausibly valid DN early + * (time spent here will be saved during the + * search due to an internal cache) + */ + casefold = ldb_dn_get_casefold(*dn); + + if (casefold == NULL) { + return ISC_R_NOTFOUND; + } + + return ISC_R_SUCCESS; + } + p = strchr(p, '.'); + if (p == NULL) { + break; + } + p++; + } + return ISC_R_NOTFOUND; +} + + +/* + see if we handle a given zone + */ +_PUBLIC_ isc_result_t dlz_findzonedb(void *dbdata, const char *name, + dns_clientinfomethods_t *methods, + dns_clientinfo_t *clientinfo) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + isc_result_t result = ISC_R_SUCCESS; + + result = b9_find_zone_dn(state, name, NULL, NULL); + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + NULL, + name, + NULL); + return result; +} + + +/* + lookup one record + */ +static isc_result_t dlz_lookup_types(struct dlz_bind9_data *state, + const char *zone, const char *name, + dns_sdlzlookup_t *lookup, + const char **types) +{ + TALLOC_CTX *tmp_ctx = talloc_new(state); + struct ldb_dn *dn; + WERROR werr = WERR_DNS_ERROR_NAME_DOES_NOT_EXIST; + struct dnsp_DnssrvRpcRecord *records = NULL; + uint16_t num_records = 0, i; + struct ldb_val zone_name_val + = data_blob_string_const(zone); + struct ldb_val name_val + = data_blob_string_const(name); + + for (i=0; zone_prefixes[i]; i++) { + int ret; + const char *casefold; + dn = ldb_dn_copy(tmp_ctx, ldb_get_default_basedn(state->samdb)); + if (dn == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + /* + * This dance ensures that it is not possible to put + * (eg) an extra DC=x, into the DNS name being + * queried + */ + + if (!ldb_dn_add_child_fmt(dn, + "DC=X,DC=X,%s", + zone_prefixes[i])) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + ret = ldb_dn_set_component(dn, + 1, + "DC", + zone_name_val); + if (ret != LDB_SUCCESS) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + ret = ldb_dn_set_component(dn, + 0, + "DC", + name_val); + if (ret != LDB_SUCCESS) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + /* + * Check if this is a plausibly valid DN early + * (time spent here will be saved during the + * search due to an internal cache) + */ + casefold = ldb_dn_get_casefold(dn); + + if (casefold == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOTFOUND; + } + + werr = dns_common_wildcard_lookup(state->samdb, tmp_ctx, dn, + &records, &num_records); + if (W_ERROR_IS_OK(werr)) { + break; + } + } + if (!W_ERROR_IS_OK(werr)) { + talloc_free(tmp_ctx); + return ISC_R_NOTFOUND; + } + + for (i=0; i < num_records; i++) { + isc_result_t result; + + result = b9_putrr(state, lookup, &records[i], types); + if (result != ISC_R_SUCCESS) { + talloc_free(tmp_ctx); + return result; + } + } + + talloc_free(tmp_ctx); + return ISC_R_SUCCESS; +} + +/* + lookup one record + */ +_PUBLIC_ isc_result_t dlz_lookup(const char *zone, const char *name, + void *dbdata, dns_sdlzlookup_t *lookup, + dns_clientinfomethods_t *methods, + dns_clientinfo_t *clientinfo) +{ + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + isc_result_t result = ISC_R_SUCCESS; + struct timeval start = timeval_current(); + + result = dlz_lookup_types(state, zone, name, lookup, NULL); + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + zone, + name, + NULL); + + return result; +} + + +/* + see if a zone transfer is allowed + */ +_PUBLIC_ isc_result_t dlz_allowzonexfr(void *dbdata, const char *name, const char *client) +{ + struct dlz_bind9_data *state = talloc_get_type( + dbdata, struct dlz_bind9_data); + isc_result_t ret; + const char **authorized_clients, **denied_clients; + const char *cname=""; + + /* check that the zone is known */ + ret = b9_find_zone_dn(state, name, NULL, NULL); + if (ret != ISC_R_SUCCESS) { + return ret; + } + + /* default is to deny all transfers */ + + authorized_clients = lpcfg_dns_zone_transfer_clients_allow(state->lp); + denied_clients = lpcfg_dns_zone_transfer_clients_deny(state->lp); + + /* The logic of allow_access() when both allow and deny lists are given + * does not match our expectation here: it would allow clients thar are + * neither allowed nor denied. + * Here, we want to deny clients by default. + * Using the allow_access() function is still useful as it takes care of + * parsing IP adresses and subnets in a consistent way with other options + * from smb.conf. + * + * We will then check the deny list first, then the allow list, so that + * we accept only clients that are explicitely allowed AND not explicitely + * denied. + */ + if ((authorized_clients == NULL) && (denied_clients == NULL)) { + /* No "allow" or "deny" lists given. Deny by default. */ + return ISC_R_NOPERM; + } + + if (denied_clients != NULL) { + bool ok = allow_access(denied_clients, NULL, cname, client); + if (!ok) { + /* client on deny list. Deny. */ + return ISC_R_NOPERM; + } + } + + if (authorized_clients != NULL) { + bool ok = allow_access(NULL, authorized_clients, cname, client); + if (ok) { + /* + * client is not on deny list and is on allow list. + * This is the only place we should return "allow". + */ + return ISC_R_SUCCESS; + } + } + /* We shouldn't get here, but deny by default. */ + return ISC_R_NOPERM; +} + +/* + perform a zone transfer + */ +_PUBLIC_ isc_result_t dlz_allnodes(const char *zone, void *dbdata, + dns_sdlzallnodes_t *allnodes) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + const char *attrs[] = { "dnsRecord", NULL }; + int ret = LDB_ERR_NO_SUCH_OBJECT; + size_t i, j; + struct ldb_dn *dn = NULL; + struct ldb_result *res; + TALLOC_CTX *tmp_ctx = talloc_new(state); + struct ldb_val zone_name_val = data_blob_string_const(zone); + isc_result_t result = ISC_R_SUCCESS; + + for (i=0; zone_prefixes[i]; i++) { + const char *casefold; + + dn = ldb_dn_copy(tmp_ctx, ldb_get_default_basedn(state->samdb)); + if (dn == NULL) { + talloc_free(tmp_ctx); + result = ISC_R_NOMEMORY; + goto exit; + } + + /* + * This dance ensures that it is not possible to put + * (eg) an extra DC=x, into the DNS name being + * queried + */ + + if (!ldb_dn_add_child_fmt(dn, + "DC=X,%s", + zone_prefixes[i])) { + talloc_free(tmp_ctx); + result = ISC_R_NOMEMORY; + goto exit; + } + + ret = ldb_dn_set_component(dn, + 0, + "DC", + zone_name_val); + if (ret != LDB_SUCCESS) { + talloc_free(tmp_ctx); + result = ISC_R_NOMEMORY; + goto exit; + } + + /* + * Check if this is a plausibly valid DN early + * (time spent here will be saved during the + * search due to an internal cache) + */ + casefold = ldb_dn_get_casefold(dn); + + if (casefold == NULL) { + result = ISC_R_NOTFOUND; + goto exit; + } + + ret = ldb_search(state->samdb, tmp_ctx, &res, dn, LDB_SCOPE_SUBTREE, + attrs, "objectClass=dnsNode"); + if (ret == LDB_SUCCESS) { + break; + } + } + if (ret != LDB_SUCCESS || dn == NULL) { + talloc_free(tmp_ctx); + result = ISC_R_NOTFOUND; + goto exit; + } + + for (i=0; i<res->count; i++) { + struct ldb_message_element *el; + TALLOC_CTX *el_ctx = talloc_new(tmp_ctx); + const char *rdn, *name; + const struct ldb_val *v; + WERROR werr; + struct dnsp_DnssrvRpcRecord *recs = NULL; + uint16_t num_recs = 0; + + el = ldb_msg_find_element(res->msgs[i], "dnsRecord"); + if (el == NULL || el->num_values == 0) { + state->log(ISC_LOG_INFO, "failed to find dnsRecord for %s", + ldb_dn_get_linearized(dn)); + talloc_free(el_ctx); + continue; + } + + v = ldb_dn_get_rdn_val(res->msgs[i]->dn); + if (v == NULL) { + state->log(ISC_LOG_INFO, "failed to find RDN for %s", + ldb_dn_get_linearized(dn)); + talloc_free(el_ctx); + continue; + } + + rdn = talloc_strndup(el_ctx, (char *)v->data, v->length); + if (rdn == NULL) { + talloc_free(tmp_ctx); + result = ISC_R_NOMEMORY; + goto exit; + } + + if (strcmp(rdn, "@") == 0) { + name = zone; + } else { + name = talloc_asprintf(el_ctx, "%s.%s", rdn, zone); + } + name = b9_format_fqdn(el_ctx, name); + if (name == NULL) { + talloc_free(tmp_ctx); + result = ISC_R_NOMEMORY; + goto exit; + } + + werr = dns_common_extract(state->samdb, el, el_ctx, &recs, &num_recs); + if (!W_ERROR_IS_OK(werr)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to parse dnsRecord for %s, %s", + ldb_dn_get_linearized(dn), win_errstr(werr)); + talloc_free(el_ctx); + continue; + } + + for (j=0; j < num_recs; j++) { + isc_result_t rc; + + rc = b9_putnamedrr(state, allnodes, name, &recs[j]); + if (rc != ISC_R_SUCCESS) { + continue; + } + } + + talloc_free(el_ctx); + } + + talloc_free(tmp_ctx); +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + zone, + NULL, + NULL); + return result; +} + + +/* + start a transaction + */ +_PUBLIC_ isc_result_t dlz_newversion(const char *zone, void *dbdata, void **versionp) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + isc_result_t result = ISC_R_SUCCESS; + + state->log(ISC_LOG_INFO, "samba_dlz: starting transaction on zone %s", zone); + + if (state->transaction_token != NULL) { + state->log(ISC_LOG_INFO, "samba_dlz: transaction already started for zone %s", zone); + result = ISC_R_FAILURE; + goto exit; + } + + state->transaction_token = talloc_zero(state, int); + if (state->transaction_token == NULL) { + result = ISC_R_NOMEMORY; + goto exit; + } + + if (ldb_transaction_start(state->samdb) != LDB_SUCCESS) { + state->log(ISC_LOG_INFO, "samba_dlz: failed to start a transaction for zone %s", zone); + talloc_free(state->transaction_token); + state->transaction_token = NULL; + result = ISC_R_FAILURE; + goto exit; + } + + *versionp = (void *)state->transaction_token; +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + zone, + NULL, + NULL); + return result; +} + +/* + end a transaction + */ +_PUBLIC_ void dlz_closeversion(const char *zone, isc_boolean_t commit, + void *dbdata, void **versionp) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + const char *data = NULL; + + data = commit ? "commit" : "cancel"; + + if (state->transaction_token != (int *)*versionp) { + state->log(ISC_LOG_INFO, "samba_dlz: transaction not started for zone %s", zone); + goto exit; + } + + if (commit) { + if (ldb_transaction_commit(state->samdb) != LDB_SUCCESS) { + state->log(ISC_LOG_INFO, "samba_dlz: failed to commit a transaction for zone %s", zone); + goto exit; + } + state->log(ISC_LOG_INFO, "samba_dlz: committed transaction on zone %s", zone); + } else { + if (ldb_transaction_cancel(state->samdb) != LDB_SUCCESS) { + state->log(ISC_LOG_INFO, "samba_dlz: failed to cancel a transaction for zone %s", zone); + goto exit; + } + state->log(ISC_LOG_INFO, "samba_dlz: cancelling transaction on zone %s", zone); + } + + talloc_free(state->transaction_token); + state->transaction_token = NULL; + *versionp = NULL; + +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(ISC_R_SUCCESS), + &start, + zone, + NULL, + data); +} + + +/* + see if there is a SOA record for a zone + */ +static bool b9_has_soa(struct dlz_bind9_data *state, struct ldb_dn *dn, const char *zone) +{ + TALLOC_CTX *tmp_ctx = talloc_new(state); + WERROR werr; + struct dnsp_DnssrvRpcRecord *records = NULL; + uint16_t num_records = 0, i; + struct ldb_val zone_name_val + = data_blob_string_const(zone); + + /* + * This dance ensures that it is not possible to put + * (eg) an extra DC=x, into the DNS name being + * queried + */ + + if (!ldb_dn_add_child_val(dn, + "DC", + zone_name_val)) { + talloc_free(tmp_ctx); + return false; + } + + /* + * The SOA record is alwas stored under DC=@,DC=zonename + * This can probably be removed when dns_common_lookup makes a fallback + * lookup on @ pseudo record + */ + + if (!ldb_dn_add_child_fmt(dn,"DC=@")) { + talloc_free(tmp_ctx); + return false; + } + + werr = dns_common_lookup(state->samdb, tmp_ctx, dn, + &records, &num_records, NULL); + if (!W_ERROR_IS_OK(werr)) { + talloc_free(tmp_ctx); + return false; + } + + for (i=0; i < num_records; i++) { + if (records[i].wType == DNS_TYPE_SOA) { + talloc_free(tmp_ctx); + return true; + } + } + + talloc_free(tmp_ctx); + return false; +} + +static bool b9_zone_add(struct dlz_bind9_data *state, const char *name) +{ + struct b9_zone *zone; + + zone = talloc_zero(state, struct b9_zone); + if (zone == NULL) { + return false; + } + + zone->name = talloc_strdup(zone, name); + if (zone->name == NULL) { + talloc_free(zone); + return false; + } + + DLIST_ADD(state->zonelist, zone); + return true; +} + +static bool b9_zone_exists(struct dlz_bind9_data *state, const char *name) +{ + struct b9_zone *zone = state->zonelist; + bool found = false; + + while (zone != NULL) { + if (strcasecmp(name, zone->name) == 0) { + found = true; + break; + } + zone = zone->next; + } + + return found; +} + + +/* + configure a writeable zone + */ +_PUBLIC_ isc_result_t dlz_configure(dns_view_t *view, dns_dlzdb_t *dlzdb, + void *dbdata) +{ + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + TALLOC_CTX *tmp_ctx; + struct ldb_dn *dn; + int i; + + state->log(ISC_LOG_INFO, "samba_dlz: starting configure"); + if (state->writeable_zone == NULL) { + state->log(ISC_LOG_INFO, "samba_dlz: no writeable_zone method available"); + return ISC_R_FAILURE; + } + + tmp_ctx = talloc_new(state); + + for (i=0; zone_prefixes[i]; i++) { + const char *attrs[] = { "name", NULL }; + int j, ret; + struct ldb_result *res; + + dn = ldb_dn_copy(tmp_ctx, ldb_get_default_basedn(state->samdb)); + if (dn == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + if (!ldb_dn_add_child_fmt(dn, "%s", zone_prefixes[i])) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + ret = ldb_search(state->samdb, tmp_ctx, &res, dn, LDB_SCOPE_SUBTREE, + attrs, "objectClass=dnsZone"); + if (ret != LDB_SUCCESS) { + continue; + } + + for (j=0; j<res->count; j++) { + isc_result_t result; + const char *zone = ldb_msg_find_attr_as_string(res->msgs[j], "name", NULL); + struct ldb_dn *zone_dn; + + if (zone == NULL) { + continue; + } + /* Ignore zones that are not handled in BIND */ + if ((strcmp(zone, "RootDNSServers") == 0) || + (strcmp(zone, "..TrustAnchors") == 0)) { + continue; + } + zone_dn = ldb_dn_copy(tmp_ctx, dn); + if (zone_dn == NULL) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + if (!b9_has_soa(state, zone_dn, zone)) { + continue; + } + + if (b9_zone_exists(state, zone)) { + state->log(ISC_LOG_WARNING, "samba_dlz: Ignoring duplicate zone '%s' from '%s'", + zone, ldb_dn_get_linearized(zone_dn)); + continue; + } + + if (!b9_zone_add(state, zone)) { + talloc_free(tmp_ctx); + return ISC_R_NOMEMORY; + } + + result = state->writeable_zone(view, dlzdb, zone); + if (result != ISC_R_SUCCESS) { + state->log(ISC_LOG_ERROR, "samba_dlz: Failed to configure zone '%s'", + zone); + talloc_free(tmp_ctx); + return result; + } + state->log(ISC_LOG_INFO, "samba_dlz: configured writeable zone '%s'", zone); + } + } + + talloc_free(tmp_ctx); + return ISC_R_SUCCESS; +} + +/* + authorize a zone update + */ +_PUBLIC_ isc_boolean_t dlz_ssumatch(const char *signer, const char *name, const char *tcpaddr, + const char *type, const char *key, uint32_t keydatalen, uint8_t *keydata, + void *dbdata) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + TALLOC_CTX *tmp_ctx; + DATA_BLOB ap_req; + struct cli_credentials *server_credentials; + char *keytab_name; + char *keytab_file = NULL; + int ret; + int ldb_ret; + NTSTATUS nt_status; + struct gensec_security *gensec_ctx; + struct auth_session_info *session_info; + struct ldb_dn *dn; + isc_result_t rc; + struct ldb_result *res; + const char * attrs[] = { NULL }; + uint32_t access_mask; + struct gensec_settings *settings = NULL; + const struct gensec_security_ops **backends = NULL; + size_t idx = 0; + isc_boolean_t result = ISC_FALSE; + NTSTATUS status; + bool ok; + + /* Remove cached credentials, if any */ + if (state->session_info) { + talloc_free(state->session_info); + state->session_info = NULL; + } + if (state->update_name) { + talloc_free(state->update_name); + state->update_name = NULL; + } + + tmp_ctx = talloc_new(state); + if (tmp_ctx == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: no memory"); + result = ISC_FALSE; + goto exit; + } + + ap_req = data_blob_const(keydata, keydatalen); + server_credentials = cli_credentials_init(tmp_ctx); + if (!server_credentials) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to init server credentials"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + status = cli_credentials_set_krb5_context(server_credentials, + state->smb_krb5_ctx); + if (!NT_STATUS_IS_OK(status)) { + state->log(ISC_LOG_ERROR, + "samba_dlz: failed to set krb5 context"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + ok = cli_credentials_set_conf(server_credentials, state->lp); + if (!ok) { + state->log(ISC_LOG_ERROR, + "samba_dlz: failed to load smb.conf"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + keytab_file = talloc_asprintf(tmp_ctx, + "%s/dns.keytab", + lpcfg_binddns_dir(state->lp)); + if (keytab_file == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: Out of memory!"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + if (!file_exist(keytab_file)) { + keytab_file = talloc_asprintf(tmp_ctx, + "%s/dns.keytab", + lpcfg_private_dir(state->lp)); + if (keytab_file == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: Out of memory!"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + } + + keytab_name = talloc_asprintf(tmp_ctx, "FILE:%s", keytab_file); + if (keytab_name == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: Out of memory!"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + ret = cli_credentials_set_keytab_name(server_credentials, state->lp, keytab_name, + CRED_SPECIFIED); + if (ret != 0) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to obtain server credentials from %s", + keytab_name); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + talloc_free(keytab_name); + + settings = lpcfg_gensec_settings(tmp_ctx, state->lp); + if (settings == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: lpcfg_gensec_settings failed"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + backends = talloc_zero_array(settings, + const struct gensec_security_ops *, 3); + if (backends == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: talloc_zero_array gensec_security_ops failed"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + settings->backends = backends; + + gensec_init(); + + backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_KERBEROS5); + backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_SPNEGO); + + nt_status = gensec_server_start(tmp_ctx, settings, + state->auth_context, &gensec_ctx); + if (!NT_STATUS_IS_OK(nt_status)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to start gensec server"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + gensec_set_credentials(gensec_ctx, server_credentials); + + nt_status = gensec_start_mech_by_oid(gensec_ctx, GENSEC_OID_SPNEGO); + if (!NT_STATUS_IS_OK(nt_status)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to start spnego"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + /* + * We only allow SPNEGO/KRB5 and make sure the backend + * to is RPC/IPC free. + * + * See gensec_gssapi_update_internal() as + * GENSEC_SERVER. + * + * It allows gensec_update() not to block. + * + * If that changes in future we need to use + * gensec_update_send/recv here! + */ + nt_status = gensec_update(gensec_ctx, tmp_ctx, ap_req, &ap_req); + if (!NT_STATUS_IS_OK(nt_status)) { + state->log(ISC_LOG_ERROR, "samba_dlz: spnego update failed"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + nt_status = gensec_session_info(gensec_ctx, tmp_ctx, &session_info); + if (!NT_STATUS_IS_OK(nt_status)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to create session info"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + /* Get the DN from name */ + rc = b9_find_name_dn(state, name, tmp_ctx, &dn); + if (rc != ISC_R_SUCCESS) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to find name %s", name); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + /* make sure the dn exists, or find parent dn in case new object is being added */ + ldb_ret = ldb_search(state->samdb, tmp_ctx, &res, dn, LDB_SCOPE_BASE, + attrs, "objectClass=dnsNode"); + if (ldb_ret == LDB_ERR_NO_SUCH_OBJECT) { + ldb_dn_remove_child_components(dn, 1); + access_mask = SEC_ADS_CREATE_CHILD; + talloc_free(res); + } else if (ldb_ret == LDB_SUCCESS) { + access_mask = SEC_STD_REQUIRED | SEC_ADS_SELF_WRITE; + talloc_free(res); + } else { + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + /* Do ACL check */ + ldb_ret = dsdb_check_access_on_dn(state->samdb, tmp_ctx, dn, + session_info->security_token, + access_mask, NULL); + if (ldb_ret != LDB_SUCCESS) { + state->log(ISC_LOG_INFO, + "samba_dlz: disallowing update of signer=%s name=%s type=%s error=%s", + signer, name, type, ldb_strerror(ldb_ret)); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + + /* Cache session_info, so it can be used in the actual add/delete operation */ + state->update_name = talloc_strdup(state, name); + if (state->update_name == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: memory allocation error"); + talloc_free(tmp_ctx); + result = ISC_FALSE; + goto exit; + } + state->session_info = talloc_steal(state, session_info); + + state->log(ISC_LOG_INFO, "samba_dlz: allowing update of signer=%s name=%s tcpaddr=%s type=%s key=%s", + signer, name, tcpaddr, type, key); + + talloc_free(tmp_ctx); + result = ISC_TRUE; +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + NULL, + name, + NULL); + return result; +} + + +/* + see if two dns records match + */ +static bool b9_record_match(struct dnsp_DnssrvRpcRecord *rec1, + struct dnsp_DnssrvRpcRecord *rec2) +{ + if (rec1->wType != rec2->wType) { + return false; + } + /* see if this type is single valued */ + if (b9_single_valued(rec1->wType)) { + return true; + } + + return dns_record_match(rec1, rec2); +} + +/* + * Update session_info on samdb using the cached credentials + */ +static bool b9_set_session_info(struct dlz_bind9_data *state, const char *name) +{ + int ret; + + if (state->update_name == NULL || state->session_info == NULL) { + state->log(ISC_LOG_ERROR, "samba_dlz: invalid credentials"); + return false; + } + + /* Do not use client credentials, if we're not updating the client specified name */ + if (strcmp(state->update_name, name) != 0) { + return true; + } + + ret = ldb_set_opaque( + state->samdb, + DSDB_SESSION_INFO, + state->session_info); + if (ret != LDB_SUCCESS) { + state->log(ISC_LOG_ERROR, "samba_dlz: unable to set session info"); + return false; + } + + return true; +} + +/* + * Reset session_info on samdb as system session + */ +static void b9_reset_session_info(struct dlz_bind9_data *state) +{ + ldb_set_opaque( + state->samdb, + DSDB_SESSION_INFO, + system_session(state->lp)); +} + +/* + add or modify a rdataset + */ +_PUBLIC_ isc_result_t dlz_addrdataset(const char *name, const char *rdatastr, void *dbdata, void *version) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + struct dnsp_DnssrvRpcRecord *rec; + struct ldb_dn *dn; + isc_result_t result = ISC_R_SUCCESS; + bool tombstoned = false; + bool needs_add = false; + struct dnsp_DnssrvRpcRecord *recs = NULL; + uint16_t num_recs = 0; + uint16_t first = 0; + uint16_t i; + WERROR werr; + + if (state->transaction_token != (void*)version) { + state->log(ISC_LOG_INFO, "samba_dlz: bad transaction version"); + result = ISC_R_FAILURE; + goto exit; + } + + rec = talloc_zero(state, struct dnsp_DnssrvRpcRecord); + if (rec == NULL) { + result = ISC_R_NOMEMORY; + goto exit; + } + + rec->rank = DNS_RANK_ZONE; + + if (!b9_parse(state, rdatastr, rec)) { + state->log(ISC_LOG_INFO, "samba_dlz: failed to parse rdataset '%s'", rdatastr); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + /* find the DN of the record */ + result = b9_find_name_dn(state, name, rec, &dn); + if (result != ISC_R_SUCCESS) { + talloc_free(rec); + goto exit; + } + + /* get any existing records */ + werr = dns_common_lookup(state->samdb, rec, dn, + &recs, &num_recs, &tombstoned); + if (W_ERROR_EQUAL(werr, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) { + needs_add = true; + werr = WERR_OK; + } + if (!W_ERROR_IS_OK(werr)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to parse dnsRecord for %s, %s", + ldb_dn_get_linearized(dn), win_errstr(werr)); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + if (tombstoned) { + /* + * we need to keep the existing tombstone record + * and ignore it + */ + first = num_recs; + } + + /* there may be existing records. We need to see if this will + * replace a record or add to it + */ + for (i=first; i < num_recs; i++) { + if (b9_record_match(rec, &recs[i])) { + break; + } + } + if (i == UINT16_MAX) { + state->log(ISC_LOG_ERROR, + "samba_dlz: failed to find record to modify, and " + "there are already %u dnsRecord values for %s", + i, ldb_dn_get_linearized(dn)); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + if (i == num_recs) { + /* set dwTimeStamp before increasing num_recs */ + if (dns_name_is_static(recs, num_recs)) { + rec->dwTimeStamp = 0; + } else { + rec->dwTimeStamp = unix_to_dns_timestamp(time(NULL)); + } + /* adding space for a new value */ + recs = talloc_realloc(rec, recs, + struct dnsp_DnssrvRpcRecord, + num_recs + 1); + if (recs == NULL) { + talloc_free(rec); + result = ISC_R_NOMEMORY; + goto exit; + } + num_recs++; + } else { + /* + * We are updating a record. Depending on whether aging is + * enabled, and how old the old timestamp is, + * dns_common_replace() will work out whether to bump the + * timestamp or not. But to do that, we need to tell it the + * old timestamp. + */ + if (! dns_name_is_static(recs, num_recs)) { + rec->dwTimeStamp = recs[i].dwTimeStamp; + } + } + + recs[i] = *rec; + + if (!b9_set_session_info(state, name)) { + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + /* modify the record */ + werr = dns_common_replace(state->samdb, rec, dn, + needs_add, + state->soa_serial, + recs, num_recs); + b9_reset_session_info(state); + if (!W_ERROR_IS_OK(werr)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to %s %s - %s", + needs_add ? "add" : "modify", + ldb_dn_get_linearized(dn), win_errstr(werr)); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + state->log(ISC_LOG_INFO, "samba_dlz: added rdataset %s '%s'", name, rdatastr); + + talloc_free(rec); +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + NULL, + name, + rdatastr); + return result; +} + +/* + remove a rdataset + */ +_PUBLIC_ isc_result_t dlz_subrdataset(const char *name, const char *rdatastr, void *dbdata, void *version) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + struct dnsp_DnssrvRpcRecord *rec; + struct ldb_dn *dn; + isc_result_t result = ISC_R_SUCCESS; + struct dnsp_DnssrvRpcRecord *recs = NULL; + uint16_t num_recs = 0; + uint16_t i; + WERROR werr; + + if (state->transaction_token != (void*)version) { + state->log(ISC_LOG_ERROR, "samba_dlz: bad transaction version"); + result = ISC_R_FAILURE; + goto exit; + } + + rec = talloc_zero(state, struct dnsp_DnssrvRpcRecord); + if (rec == NULL) { + result = ISC_R_NOMEMORY; + goto exit; + } + + if (!b9_parse(state, rdatastr, rec)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to parse rdataset '%s'", rdatastr); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + /* find the DN of the record */ + result = b9_find_name_dn(state, name, rec, &dn); + if (result != ISC_R_SUCCESS) { + talloc_free(rec); + goto exit; + } + + /* get the existing records */ + werr = dns_common_lookup(state->samdb, rec, dn, + &recs, &num_recs, NULL); + if (!W_ERROR_IS_OK(werr)) { + talloc_free(rec); + result = ISC_R_NOTFOUND; + goto exit; + } + + for (i=0; i < num_recs; i++) { + if (b9_record_match(rec, &recs[i])) { + recs[i] = (struct dnsp_DnssrvRpcRecord) { + .wType = DNS_TYPE_TOMBSTONE, + }; + break; + } + } + if (i == num_recs) { + talloc_free(rec); + result = ISC_R_NOTFOUND; + goto exit; + } + + if (!b9_set_session_info(state, name)) { + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + /* modify the record */ + werr = dns_common_replace(state->samdb, rec, dn, + false,/* needs_add */ + state->soa_serial, + recs, num_recs); + b9_reset_session_info(state); + if (!W_ERROR_IS_OK(werr)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to modify %s - %s", + ldb_dn_get_linearized(dn), win_errstr(werr)); + talloc_free(rec); + result = ISC_R_FAILURE; + goto exit; + } + + state->log(ISC_LOG_INFO, "samba_dlz: subtracted rdataset %s '%s'", name, rdatastr); + + talloc_free(rec); +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + NULL, + name, + rdatastr); + return result; +} + + +/* + delete all records of the given type + */ +_PUBLIC_ isc_result_t dlz_delrdataset(const char *name, const char *type, void *dbdata, void *version) +{ + struct timeval start = timeval_current(); + struct dlz_bind9_data *state = talloc_get_type_abort(dbdata, struct dlz_bind9_data); + TALLOC_CTX *tmp_ctx; + struct ldb_dn *dn; + isc_result_t result = ISC_R_SUCCESS; + enum dns_record_type dns_type; + bool found = false; + struct dnsp_DnssrvRpcRecord *recs = NULL; + uint16_t num_recs = 0; + uint16_t ri = 0; + WERROR werr; + + if (state->transaction_token != (void*)version) { + state->log(ISC_LOG_ERROR, "samba_dlz: bad transaction version"); + result = ISC_R_FAILURE; + goto exit; + } + + if (!b9_dns_type(type, &dns_type)) { + state->log(ISC_LOG_ERROR, "samba_dlz: bad dns type %s in delete", type); + result = ISC_R_FAILURE; + goto exit; + } + + tmp_ctx = talloc_new(state); + + /* find the DN of the record */ + result = b9_find_name_dn(state, name, tmp_ctx, &dn); + if (result != ISC_R_SUCCESS) { + talloc_free(tmp_ctx); + goto exit; + } + + /* get the existing records */ + werr = dns_common_lookup(state->samdb, tmp_ctx, dn, + &recs, &num_recs, NULL); + if (!W_ERROR_IS_OK(werr)) { + talloc_free(tmp_ctx); + result = ISC_R_NOTFOUND; + goto exit; + } + + for (ri=0; ri < num_recs; ri++) { + if (dns_type != recs[ri].wType) { + continue; + } + + found = true; + recs[ri] = (struct dnsp_DnssrvRpcRecord) { + .wType = DNS_TYPE_TOMBSTONE, + }; + } + + if (!found) { + talloc_free(tmp_ctx); + result = ISC_R_FAILURE; + goto exit; + } + + if (!b9_set_session_info(state, name)) { + talloc_free(tmp_ctx); + result = ISC_R_FAILURE; + goto exit; + } + + /* modify the record */ + werr = dns_common_replace(state->samdb, tmp_ctx, dn, + false,/* needs_add */ + state->soa_serial, + recs, num_recs); + b9_reset_session_info(state); + if (!W_ERROR_IS_OK(werr)) { + state->log(ISC_LOG_ERROR, "samba_dlz: failed to modify %s - %s", + ldb_dn_get_linearized(dn), win_errstr(werr)); + talloc_free(tmp_ctx); + result = ISC_R_FAILURE; + goto exit; + } + + state->log(ISC_LOG_INFO, "samba_dlz: deleted rdataset %s of type %s", name, type); + + talloc_free(tmp_ctx); +exit: + DNS_COMMON_LOG_OPERATION( + isc_result_str(result), + &start, + NULL, + name, + type); + return result; +} |