Refactor the dns_name API to use ISC_THREAD_LOCAL

Previously, the dns_name API used isc_thread_key API for TLS, which is
fairly complicated and requires initialization of memory contexts, etc.
This part of code was refactored to use a ISC_THREAD_LOCAL pointer which
greatly simplifies the whole code related to storing TLS variables.

bin/check/named-checkconf.c

@@ -709,8 +709,6 @@ main(int argc, char **argv) {
 
 	cfg_parser_destroy(&parser);
 
-	dns_name_destroy();
-
 	isc_log_destroy(&logc);
 
 	isc_mem_destroy(&mctx);

bin/check/named-checkzone.c

@@ -85,9 +85,9 @@ usage(void) {
 
 static void
 destroy(void) {
-	if (zone != NULL)
+	if (zone != NULL) {
 		dns_zone_detach(&zone);
-	dns_name_destroy();
+	}
 }
 
 /*% main processing routine */

bin/dig/dighost.c

@@ -4252,7 +4252,6 @@ destroy_libs(void) {
 	result = dns_name_settotextfilter(NULL);
 	check_result(result, "dns_name_settotextfilter");
 #endif /* HAVE_LIBIDN2 */
-	dns_name_destroy();
 
 	if (commctx != NULL) {
 		debug("freeing commctx");

bin/dnssec/dnssec-dsfromkey.c

@@ -517,7 +517,6 @@ main(int argc, char **argv) {
 	}
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10) {
 		isc_mem_stats(mctx, stdout);
 	}

bin/dnssec/dnssec-importkey.c

@@ -439,7 +439,6 @@ main(int argc, char **argv) {
 		dns_rdataset_disassociate(&rdataset);
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10)
 		isc_mem_stats(mctx, stdout);
 	isc_mem_destroy(&mctx);

bin/dnssec/dnssec-keyfromlabel.c

@@ -694,7 +694,6 @@ main(int argc, char **argv) {
 
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10)
 		isc_mem_stats(mctx, stdout);
 	isc_mem_free(mctx, label);

bin/dnssec/dnssec-keygen.c

@@ -1222,7 +1222,6 @@ main(int argc, char **argv) {
 
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10)
 		isc_mem_stats(mctx, stdout);
 	isc_mem_destroy(&mctx);

bin/dnssec/dnssec-signzone.c

@@ -3922,7 +3922,6 @@ main(int argc, char *argv[]) {
 
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10)
 		isc_mem_stats(mctx, stdout);
 	isc_mem_destroy(&mctx);

bin/dnssec/dnssec-verify.c

@@ -335,7 +335,6 @@ main(int argc, char *argv[]) {
 
 	cleanup_logging(&log);
 	dst_lib_destroy();
-	dns_name_destroy();
 	if (verbose > 10)
 		isc_mem_stats(mctx, stdout);
 	isc_mem_destroy(&mctx);

bin/named/main.c

@@ -1329,8 +1329,6 @@ cleanup(void) {
 	dlz_dlopen_clear();
 #endif
 
-	dns_name_destroy();
-
 	isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
 		      NAMED_LOGMODULE_MAIN,
 		      ISC_LOG_NOTICE, "exiting");

bin/nsupdate/nsupdate.c

@@ -3210,9 +3210,6 @@ cleanup(void) {
 	ddebug("Shutting down timer manager");
 	isc_timermgr_destroy(&timermgr);
 
-	ddebug("Destroying name state");
-	dns_name_destroy();
-
 	ddebug("Removing log context");
 	isc_log_destroy(&glctx);
 

bin/rndc/rndc.c

@@ -1022,8 +1022,6 @@ main(int argc, char **argv) {
 	isc_mem_put(rndc_mctx, args, argslen);
 	isccc_ccmsg_invalidate(&ccmsg);
 
-	dns_name_destroy();
-
 	isc_buffer_free(&databuf);
 
 	if (show_final_mem)

bin/tests/system/rsabigexponent/bigkey.c

@@ -145,7 +145,6 @@ main(int argc, char **argv) {
 	isc_log_setcontext(NULL);
 	dns_log_setcontext(NULL);
 	dst_lib_destroy();
-	dns_name_destroy();
 	isc_mem_destroy(&mctx);
 	return (0);
 #else /* !USE_PKCS11 */

lib/dns/include/dns/name.h

@@ -197,8 +197,8 @@ LIBDNS_EXTERNAL_DATA extern const dns_name_t *dns_wildcardname;
  * 'target' is the buffer to be converted.  The region to be converted
  * is from 'buffer'->base + 'used_org' to the end of the used region.
  */
-typedef isc_result_t (*dns_name_totextfilter_t)(isc_buffer_t *target,
-						unsigned int used_org);
+typedef isc_result_t (dns_name_totextfilter_t)(isc_buffer_t *target,
+					       unsigned int used_org);
 
 /***
  *** Initialization
@@ -1217,7 +1217,7 @@ dns_name_fromstring2(dns_name_t *target, const char *src,
  */
 
 isc_result_t
-dns_name_settotextfilter(dns_name_totextfilter_t proc);
+dns_name_settotextfilter(dns_name_totextfilter_t *proc);
 /*%<
  * Set / clear a thread specific function 'proc' to be called at the
  * end of dns_name_totext().
@@ -1296,18 +1296,6 @@ dns_name_internalwildcard(const dns_name_t *name);
  * \li	'name' to be valid.
  */
 
-void
-dns_name_destroy(void);
-/*%<
- * Cleanup dns_name_settotextfilter() / dns_name_totext() state.
- *
- * This should be called as part of the final cleanup process.
- *
- * Note: dns_name_settotextfilter(NULL); should be called for all
- * threads which have called dns_name_settotextfilter() with a
- * non-NULL argument prior to calling dns_name_destroy();
- */
-
 bool
 dns_name_isdnssd(const dns_name_t *owner);
 /*%<

lib/dns/name.c

@@ -163,11 +163,7 @@ LIBDNS_EXTERNAL_DATA const dns_name_t *dns_wildcardname = &wild;
 /*
  * dns_name_t to text post-conversion procedure.
  */
-static int thread_key_initialized = 0;
-static isc_mutex_t thread_key_mutex;
-static isc_mem_t *thread_key_mctx = NULL;
-static isc_thread_key_t totext_filter_proc_key;
-static isc_once_t once = ISC_ONCE_INIT;
+ISC_THREAD_LOCAL dns_name_totextfilter_t *totext_filter_proc = NULL;
 
 static void
 set_offsets(const dns_name_t *name, unsigned char *offsets,
@@ -1272,52 +1268,6 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
 	return (ISC_R_SUCCESS);
 }
 
-static void
-free_specific(void *arg) {
-	dns_name_totextfilter_t *mem = arg;
-	isc_mem_put(thread_key_mctx, mem, sizeof(*mem));
-	/* Stop use being called again. */
-	(void)isc_thread_key_setspecific(totext_filter_proc_key, NULL);
-}
-
-static void
-thread_key_mutex_init(void) {
-	isc_mutex_init(&thread_key_mutex);
-}
-
-static isc_result_t
-totext_filter_proc_key_init(void) {
-	isc_result_t result;
-
-	/*
-	 * We need the call to isc_once_do() to support profiled mutex
-	 * otherwise thread_key_mutex could be initialized at compile time.
-	 */
-	result = isc_once_do(&once, thread_key_mutex_init);
-	if (result != ISC_R_SUCCESS)
-		return (result);
-
-	if (!thread_key_initialized) {
-		LOCK(&thread_key_mutex);
-		if (thread_key_mctx == NULL) {
-			isc_mem_create(&thread_key_mctx);
-		}
-		isc_mem_setname(thread_key_mctx, "threadkey", NULL);
-		isc_mem_setdestroycheck(thread_key_mctx, false);
-
-		if (!thread_key_initialized &&
-		     isc_thread_key_create(&totext_filter_proc_key,
-					   free_specific) != 0) {
-			result = ISC_R_FAILURE;
-			isc_mem_detach(&thread_key_mctx);
-		} else {
-			thread_key_initialized = 1;
-		}
-		UNLOCK(&thread_key_mutex);
-	}
-	return (result);
-}
-
 isc_result_t
 dns_name_totext(const dns_name_t *name, bool omit_final_dot,
 		isc_buffer_t *target)
@@ -1346,9 +1296,6 @@ dns_name_totext2(const dns_name_t *name, unsigned int options,
 	unsigned int labels;
 	bool saw_root = false;
 	unsigned int oused;
-	dns_name_totextfilter_t *mem;
-	dns_name_totextfilter_t totext_filter_proc = NULL;
-	isc_result_t result;
 	bool omit_final_dot = ((options & DNS_NAME_OMITFINALDOT) != 0);
 
 	/*
@@ -1360,9 +1307,6 @@ dns_name_totext2(const dns_name_t *name, unsigned int options,
 
 	oused = target->used;
 
-	result = totext_filter_proc_key_init();
-	if (result != ISC_R_SUCCESS)
-		return (result);
 	ndata = name->ndata;
 	nlen = name->length;
 	labels = name->labels;
@@ -1502,11 +1446,9 @@ dns_name_totext2(const dns_name_t *name, unsigned int options,
 	}
 	isc_buffer_add(target, tlen - trem);
 
-	mem = isc_thread_key_getspecific(totext_filter_proc_key);
-	if (mem != NULL)
-		totext_filter_proc = *mem;
-	if (totext_filter_proc != NULL)
-		return ((*totext_filter_proc)(target, oused));
+	if (totext_filter_proc != NULL) {
+		return ((totext_filter_proc)(target, oused));
+	}
 
 	return (ISC_R_SUCCESS);
 }
@@ -2320,40 +2262,23 @@ dns_name_print(const dns_name_t *name, FILE *stream) {
 }
 
 isc_result_t
-dns_name_settotextfilter(dns_name_totextfilter_t proc) {
-	isc_result_t result;
-	dns_name_totextfilter_t *mem;
-	int res;
-
-	result = totext_filter_proc_key_init();
-	if (result != ISC_R_SUCCESS)
-		return (result);
-
+dns_name_settotextfilter(dns_name_totextfilter_t *proc) {
 	/*
 	 * If we already have been here set / clear as appropriate.
-	 * Otherwise allocate memory.
 	 */
-	mem = isc_thread_key_getspecific(totext_filter_proc_key);
-	if (mem != NULL && proc != NULL) {
-		*mem = proc;
+	if (totext_filter_proc != NULL && proc != NULL) {
+		if (totext_filter_proc == proc) {
+			return (ISC_R_SUCCESS);
+		}
+	}
+	if (proc == NULL && totext_filter_proc != NULL) {
+		totext_filter_proc = NULL;
 		return (ISC_R_SUCCESS);
 	}
-	if (proc == NULL) {
-		if (mem != NULL)
-			isc_mem_put(thread_key_mctx, mem, sizeof(*mem));
-		res = isc_thread_key_setspecific(totext_filter_proc_key, NULL);
-		if (res != 0)
-			result = ISC_R_UNEXPECTED;
-		return (result);
-	}
 
-	mem = isc_mem_get(thread_key_mctx, sizeof(*mem));
-	*mem = proc;
-	if (isc_thread_key_setspecific(totext_filter_proc_key, mem) != 0) {
-		isc_mem_put(thread_key_mctx, mem, sizeof(*mem));
-		result = ISC_R_UNEXPECTED;
-	}
-	return (result);
+	totext_filter_proc = proc;
+
+	return (ISC_R_SUCCESS);
 }
 
 void
@@ -2511,21 +2436,6 @@ dns_name_copynf(const dns_name_t *source, dns_name_t *dest)
 	RUNTIME_CHECK(name_copy(source, dest, dest->buffer) == ISC_R_SUCCESS);
 }
 
-void
-dns_name_destroy(void) {
-	RUNTIME_CHECK(isc_once_do(&once, thread_key_mutex_init)
-				  == ISC_R_SUCCESS);
-
-	LOCK(&thread_key_mutex);
-	if (thread_key_initialized) {
-		isc_mem_detach(&thread_key_mctx);
-		isc_thread_key_delete(totext_filter_proc_key);
-		thread_key_initialized = 0;
-	}
-	UNLOCK(&thread_key_mutex);
-
-}
-
 /*
  * Service Discovery Prefixes RFC 6763.
  */

lib/dns/win32/libdns.def.in

@@ -584,7 +584,6 @@ dns_name_concatenate
 dns_name_copy
 dns_name_copynf
 dns_name_countlabels
-dns_name_destroy
 dns_name_digest
 dns_name_downcase
 dns_name_dup