1 files changed, 552 insertions, 0 deletions
diff --git a/bin/named/dlz_dlopen_driver.c b/bin/named/dlz_dlopen_driver.c
new file mode 100644
index 0000000..f636cd2
--- /dev/null
+++ b/bin/named/dlz_dlopen_driver.c
@@ -0,0 +1,552 @@
+/*
+ * 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.
+ */
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <uv.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/dlz_dlopen.h>
+#include <dns/log.h>
+
+#include <dlz/dlz_dlopen_driver.h>
+#include <named/globals.h>
+
+static dns_sdlzimplementation_t *dlz_dlopen = NULL;
+
+typedef struct dlopen_data {
+	isc_mem_t *mctx;
+	char *dl_path;
+	char *dlzname;
+	uv_lib_t dl_handle;
+	void *dbdata;
+	unsigned int flags;
+	isc_mutex_t lock;
+	int version;
+	bool in_configure;
+
+	dlz_dlopen_version_t *dlz_version;
+	dlz_dlopen_create_t *dlz_create;
+	dlz_dlopen_findzonedb_t *dlz_findzonedb;
+	dlz_dlopen_lookup_t *dlz_lookup;
+	dlz_dlopen_authority_t *dlz_authority;
+	dlz_dlopen_allnodes_t *dlz_allnodes;
+	dlz_dlopen_allowzonexfr_t *dlz_allowzonexfr;
+	dlz_dlopen_newversion_t *dlz_newversion;
+	dlz_dlopen_closeversion_t *dlz_closeversion;
+	dlz_dlopen_configure_t *dlz_configure;
+	dlz_dlopen_ssumatch_t *dlz_ssumatch;
+	dlz_dlopen_addrdataset_t *dlz_addrdataset;
+	dlz_dlopen_subrdataset_t *dlz_subrdataset;
+	dlz_dlopen_delrdataset_t *dlz_delrdataset;
+	dlz_dlopen_destroy_t *dlz_destroy;
+} dlopen_data_t;
+
+/* Modules can choose whether they are lock-safe or not. */
+#define MAYBE_LOCK(cd)                                            \
+	do {                                                      \
+		if ((cd->flags & DNS_SDLZFLAG_THREADSAFE) == 0 && \
+		    !cd->in_configure)                            \
+			LOCK(&cd->lock);                          \
+	} while (0)
+
+#define MAYBE_UNLOCK(cd)                                          \
+	do {                                                      \
+		if ((cd->flags & DNS_SDLZFLAG_THREADSAFE) == 0 && \
+		    !cd->in_configure)                            \
+			UNLOCK(&cd->lock);                        \
+	} while (0)
+
+/*
+ * Log a message at the given level.
+ */
+static void
+dlopen_log(int level, const char *fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DLZ,
+		       ISC_LOG_DEBUG(level), fmt, ap);
+	va_end(ap);
+}
+
+/*
+ * SDLZ methods
+ */
+
+static isc_result_t
+dlopen_dlz_allnodes(const char *zone, void *driverarg, void *dbdata,
+		    dns_sdlzallnodes_t *allnodes) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_allnodes == NULL) {
+		return (ISC_R_NOPERM);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_allnodes(zone, cd->dbdata, allnodes);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+static isc_result_t
+dlopen_dlz_allowzonexfr(void *driverarg, void *dbdata, const char *name,
+			const char *client) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_allowzonexfr == NULL) {
+		return (ISC_R_NOPERM);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_allowzonexfr(cd->dbdata, name, client);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+static isc_result_t
+dlopen_dlz_authority(const char *zone, void *driverarg, void *dbdata,
+		     dns_sdlzlookup_t *lookup) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_authority == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_authority(zone, cd->dbdata, lookup);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+static isc_result_t
+dlopen_dlz_findzonedb(void *driverarg, void *dbdata, const char *name,
+		      dns_clientinfomethods_t *methods,
+		      dns_clientinfo_t *clientinfo) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_findzonedb(cd->dbdata, name, methods, clientinfo);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+static isc_result_t
+dlopen_dlz_lookup(const char *zone, const char *name, void *driverarg,
+		  void *dbdata, dns_sdlzlookup_t *lookup,
+		  dns_clientinfomethods_t *methods,
+		  dns_clientinfo_t *clientinfo) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_lookup(zone, name, cd->dbdata, lookup, methods,
+				clientinfo);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+/*
+ * Load a symbol from the library
+ */
+static void *
+dl_load_symbol(dlopen_data_t *cd, const char *symbol, bool mandatory) {
+	void *ptr = NULL;
+	int r = uv_dlsym(&cd->dl_handle, symbol, &ptr);
+	if (r != 0) {
+		const char *errmsg = uv_dlerror(&cd->dl_handle);
+		if (errmsg == NULL) {
+			errmsg = "returned function pointer is NULL";
+		}
+		if (mandatory) {
+			dlopen_log(ISC_LOG_ERROR,
+				   "dlz_dlopen: library '%s' is missing "
+				   "required symbol '%s': %s",
+				   cd->dl_path, symbol, errmsg);
+		}
+	}
+
+	return (ptr);
+}
+
+static void
+dlopen_dlz_destroy(void *driverarg, void *dbdata);
+
+/*
+ * Called at startup for each dlopen zone in named.conf
+ */
+static isc_result_t
+dlopen_dlz_create(const char *dlzname, unsigned int argc, char *argv[],
+		  void *driverarg, void **dbdata) {
+	dlopen_data_t *cd;
+	isc_mem_t *mctx = NULL;
+	isc_result_t result = ISC_R_FAILURE;
+	int r;
+
+	UNUSED(driverarg);
+
+	if (argc < 2) {
+		dlopen_log(ISC_LOG_ERROR,
+			   "dlz_dlopen driver for '%s' needs a path to "
+			   "the shared library",
+			   dlzname);
+		return (ISC_R_FAILURE);
+	}
+
+	isc_mem_create(&mctx);
+	cd = isc_mem_get(mctx, sizeof(*cd));
+	memset(cd, 0, sizeof(*cd));
+
+	cd->mctx = mctx;
+
+	cd->dl_path = isc_mem_strdup(cd->mctx, argv[1]);
+	cd->dlzname = isc_mem_strdup(cd->mctx, dlzname);
+
+	/* Initialize the lock */
+	isc_mutex_init(&cd->lock);
+
+	r = uv_dlopen(cd->dl_path, &cd->dl_handle);
+	if (r != 0) {
+		const char *errmsg = uv_dlerror(&cd->dl_handle);
+		if (errmsg == NULL) {
+			errmsg = "unknown error";
+		}
+		dlopen_log(ISC_LOG_ERROR,
+			   "dlz_dlopen failed to open library '%s': %s",
+			   cd->dl_path, errmsg);
+		result = ISC_R_FAILURE;
+		goto failed;
+	}
+
+	/* Find the symbols */
+	cd->dlz_version =
+		(dlz_dlopen_version_t *)dl_load_symbol(cd, "dlz_version", true);
+	cd->dlz_create = (dlz_dlopen_create_t *)dl_load_symbol(cd, "dlz_create",
+							       true);
+	cd->dlz_lookup = (dlz_dlopen_lookup_t *)dl_load_symbol(cd, "dlz_lookup",
+							       true);
+	cd->dlz_findzonedb = (dlz_dlopen_findzonedb_t *)dl_load_symbol(
+		cd, "dlz_findzonedb", true);
+
+	if (cd->dlz_create == NULL || cd->dlz_version == NULL ||
+	    cd->dlz_lookup == NULL || cd->dlz_findzonedb == NULL)
+	{
+		/* We're missing a required symbol */
+		result = ISC_R_FAILURE;
+		goto failed;
+	}
+
+	cd->dlz_allowzonexfr = (dlz_dlopen_allowzonexfr_t *)dl_load_symbol(
+		cd, "dlz_allowzonexfr", false);
+	cd->dlz_allnodes = (dlz_dlopen_allnodes_t *)dl_load_symbol(
+		cd, "dlz_allnodes", (cd->dlz_allowzonexfr != NULL));
+	cd->dlz_authority = (dlz_dlopen_authority_t *)dl_load_symbol(
+		cd, "dlz_authority", false);
+	cd->dlz_newversion = (dlz_dlopen_newversion_t *)dl_load_symbol(
+		cd, "dlz_newversion", false);
+	cd->dlz_closeversion = (dlz_dlopen_closeversion_t *)dl_load_symbol(
+		cd, "dlz_closeversion", (cd->dlz_newversion != NULL));
+	cd->dlz_configure = (dlz_dlopen_configure_t *)dl_load_symbol(
+		cd, "dlz_configure", false);
+	cd->dlz_ssumatch = (dlz_dlopen_ssumatch_t *)dl_load_symbol(
+		cd, "dlz_ssumatch", false);
+	cd->dlz_addrdataset = (dlz_dlopen_addrdataset_t *)dl_load_symbol(
+		cd, "dlz_addrdataset", false);
+	cd->dlz_subrdataset = (dlz_dlopen_subrdataset_t *)dl_load_symbol(
+		cd, "dlz_subrdataset", false);
+	cd->dlz_delrdataset = (dlz_dlopen_delrdataset_t *)dl_load_symbol(
+		cd, "dlz_delrdataset", false);
+	cd->dlz_destroy = (dlz_dlopen_destroy_t *)dl_load_symbol(
+		cd, "dlz_destroy", false);
+
+	/* Check the version of the API is the same */
+	cd->version = cd->dlz_version(&cd->flags);
+	if (cd->version < (DLZ_DLOPEN_VERSION - DLZ_DLOPEN_AGE) ||
+	    cd->version > DLZ_DLOPEN_VERSION)
+	{
+		dlopen_log(ISC_LOG_ERROR,
+			   "dlz_dlopen: %s: incorrect driver API version %d, "
+			   "requires %d",
+			   cd->dl_path, cd->version, DLZ_DLOPEN_VERSION);
+		result = ISC_R_FAILURE;
+		goto failed;
+	}
+
+	/*
+	 * Call the library's create function. Note that this is an
+	 * extended version of dlz create, with the addition of
+	 * named function pointers for helper functions that the
+	 * driver will need. This avoids the need for the backend to
+	 * link the BIND9 libraries
+	 */
+	MAYBE_LOCK(cd);
+	result = cd->dlz_create(dlzname, argc - 1, argv + 1, &cd->dbdata, "log",
+				dlopen_log, "putrr", dns_sdlz_putrr,
+				"putnamedrr", dns_sdlz_putnamedrr,
+				"writeable_zone", dns_dlz_writeablezone, NULL);
+	MAYBE_UNLOCK(cd);
+	if (result != ISC_R_SUCCESS) {
+		goto failed;
+	}
+
+	*dbdata = cd;
+
+	return (ISC_R_SUCCESS);
+
+failed:
+	dlopen_log(ISC_LOG_ERROR, "dlz_dlopen of '%s' failed", dlzname);
+
+	dlopen_dlz_destroy(NULL, cd);
+
+	return (result);
+}
+
+/*
+ * Called when bind is shutting down
+ */
+static void
+dlopen_dlz_destroy(void *driverarg, void *dbdata) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_destroy && cd->dbdata) {
+		MAYBE_LOCK(cd);
+		cd->dlz_destroy(cd->dbdata);
+		MAYBE_UNLOCK(cd);
+	}
+
+	uv_dlclose(&cd->dl_handle);
+	isc_mutex_destroy(&cd->lock);
+	isc_mem_free(cd->mctx, cd->dl_path);
+	isc_mem_free(cd->mctx, cd->dlzname);
+	isc_mem_putanddetach(&cd->mctx, cd, sizeof(*cd));
+}
+
+/*
+ * Called to start a transaction
+ */
+static isc_result_t
+dlopen_dlz_newversion(const char *zone, void *driverarg, void *dbdata,
+		      void **versionp) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_newversion == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_newversion(zone, cd->dbdata, versionp);
+	MAYBE_UNLOCK(cd);
+	return (result);
+}
+
+/*
+ * Called to end a transaction
+ */
+static void
+dlopen_dlz_closeversion(const char *zone, bool commit, void *driverarg,
+			void *dbdata, void **versionp) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_newversion == NULL) {
+		*versionp = NULL;
+		return;
+	}
+
+	MAYBE_LOCK(cd);
+	cd->dlz_closeversion(zone, commit, cd->dbdata, versionp);
+	MAYBE_UNLOCK(cd);
+}
+
+/*
+ * Called on startup to configure any writeable zones
+ */
+static isc_result_t
+dlopen_dlz_configure(dns_view_t *view, dns_dlzdb_t *dlzdb, void *driverarg,
+		     void *dbdata) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_configure == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
+	MAYBE_LOCK(cd);
+	cd->in_configure = true;
+	result = cd->dlz_configure(view, dlzdb, cd->dbdata);
+	cd->in_configure = false;
+	MAYBE_UNLOCK(cd);
+
+	return (result);
+}
+
+/*
+ * Check for authority to change a name.
+ */
+static bool
+dlopen_dlz_ssumatch(const char *signer, const char *name, const char *tcpaddr,
+		    const char *type, const char *key, uint32_t keydatalen,
+		    unsigned char *keydata, void *driverarg, void *dbdata) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	bool ret;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_ssumatch == NULL) {
+		return (false);
+	}
+
+	MAYBE_LOCK(cd);
+	ret = cd->dlz_ssumatch(signer, name, tcpaddr, type, key, keydatalen,
+			       keydata, cd->dbdata);
+	MAYBE_UNLOCK(cd);
+
+	return (ret);
+}
+
+/*
+ * Add an rdataset.
+ */
+static isc_result_t
+dlopen_dlz_addrdataset(const char *name, const char *rdatastr, void *driverarg,
+		       void *dbdata, void *version) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_addrdataset == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_addrdataset(name, rdatastr, cd->dbdata, version);
+	MAYBE_UNLOCK(cd);
+
+	return (result);
+}
+
+/*
+ * Subtract an rdataset.
+ */
+static isc_result_t
+dlopen_dlz_subrdataset(const char *name, const char *rdatastr, void *driverarg,
+		       void *dbdata, void *version) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_subrdataset == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_subrdataset(name, rdatastr, cd->dbdata, version);
+	MAYBE_UNLOCK(cd);
+
+	return (result);
+}
+
+/*
+ * Delete a rdataset.
+ */
+static isc_result_t
+dlopen_dlz_delrdataset(const char *name, const char *type, void *driverarg,
+		       void *dbdata, void *version) {
+	dlopen_data_t *cd = (dlopen_data_t *)dbdata;
+	isc_result_t result;
+
+	UNUSED(driverarg);
+
+	if (cd->dlz_delrdataset == NULL) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	MAYBE_LOCK(cd);
+	result = cd->dlz_delrdataset(name, type, cd->dbdata, version);
+	MAYBE_UNLOCK(cd);
+
+	return (result);
+}
+
+static dns_sdlzmethods_t dlz_dlopen_methods = {
+	dlopen_dlz_create,	 dlopen_dlz_destroy,	dlopen_dlz_findzonedb,
+	dlopen_dlz_lookup,	 dlopen_dlz_authority,	dlopen_dlz_allnodes,
+	dlopen_dlz_allowzonexfr, dlopen_dlz_newversion, dlopen_dlz_closeversion,
+	dlopen_dlz_configure,	 dlopen_dlz_ssumatch,	dlopen_dlz_addrdataset,
+	dlopen_dlz_subrdataset,	 dlopen_dlz_delrdataset
+};
+
+/*
+ * Register driver with BIND
+ */
+isc_result_t
+dlz_dlopen_init(isc_mem_t *mctx) {
+	isc_result_t result;
+
+	dlopen_log(2, "Registering DLZ_dlopen driver");
+
+	result = dns_sdlzregister("dlopen", &dlz_dlopen_methods, NULL,
+				  DNS_SDLZFLAG_RELATIVEOWNER |
+					  DNS_SDLZFLAG_RELATIVERDATA |
+					  DNS_SDLZFLAG_THREADSAFE,
+				  mctx, &dlz_dlopen);
+
+	if (result != ISC_R_SUCCESS) {
+		UNEXPECTED_ERROR("dns_sdlzregister() failed: %s",
+				 isc_result_totext(result));
+		result = ISC_R_UNEXPECTED;
+	}
+
+	return (result);
+}
+
+/*
+ * Unregister the driver
+ */
+void
+dlz_dlopen_clear(void) {
+	dlopen_log(2, "Unregistering DLZ_dlopen driver");
+	if (dlz_dlopen != NULL) {
+		dns_sdlzunregister(&dlz_dlopen);
+	}
+}