Cachedb no store

cachedb/cachedb.c

@@ -815,6 +815,11 @@ cachedb_handle_response(struct module_qstate* qstate,
 		qstate->ext_state[id] = module_finished;
 		return;
 	}
+	if(qstate->env->cfg->cachedb_no_store) {
+		/* do not store the item in the external cache */
+		qstate->ext_state[id] = module_finished;
+		return;
+	}
 
 	/* store the item into the backend cache */
 	cachedb_extcache_store(qstate, ie);

doc/example.conf.in

@@ -1226,6 +1226,8 @@ remote-control:
 #     backend: "testframe"
 #     # secret seed string to calculate hashed keys
 #     secret-seed: "default"
+#     # if the backend should be read from, but not written to.
+#     cachedb-no-store: no
 #
 #     # For "redis" backend:
 #     # (to enable, use --with-libhiredis to configure before compiling)

doc/unbound.conf.5.in

@@ -2681,6 +2681,11 @@ operationally.
 If the backend database is shared by multiple Unbound instances,
 all instances must use the same secret seed.
 This option defaults to "default".
+.TP
+.B cachedb-no-store: \fI<yes or no>\fR
+If the backend should be read from, but not written to. This makes this
+instance not store dns messages in the backend. But if data is available it
+is retrieved. The default is no.
 .P
 The following
 .B cachedb

testdata/cachedb_no_store.tdir/cachedb_no_store.conf

@@ -0,0 +1,29 @@
+server:
+	verbosity: 4
+	interface: 127.0.0.1
+	port: @PORT@
+	use-syslog: no
+	directory: ""
+	pidfile: "unbound.pid"
+	chroot: ""
+	username: ""
+	module-config: "cachedb iterator"
+	do-not-query-localhost: no
+	qname-minimisation: no
+
+forward-zone:
+	name: "."
+	forward-addr: 127.0.0.1@@TOPORT@
+
+stub-zone:
+	name: "example.com"
+	stub-addr: 127.0.0.1@@TOPORT@
+
+remote-control:
+	control-enable: yes
+	control-interface: @CONTROL_PATH@/controlpipe.@CONTROL_PID@
+	control-use-cert: no
+
+cachedb:
+	backend: "testframe"
+	secret-seed: "testvalue"

testdata/cachedb_no_store.tdir/cachedb_no_store.dsc

@@ -0,0 +1,16 @@
+BaseName: cachedb_no_store
+Version: 1.0
+Description: cachedb test the cachedb-no-store option
+CreationDate: Wed 11 Oct 11:00:00 CEST 2023
+Maintainer: dr. W.C.A. Wijngaards
+Category: 
+Component:
+CmdDepends: 
+Depends: 
+Help:
+Pre: cachedb_no_store.pre
+Post: cachedb_no_store.post
+Test: cachedb_no_store.test
+AuxFiles: 
+Passed:
+Failure:

testdata/cachedb_no_store.tdir/cachedb_no_store.post

@@ -0,0 +1,21 @@
+# #-- cachedb_no_store.post --#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# source the test var file when it's there
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+#
+# do your teardown here
+PRE="../.."
+. ../common.sh
+if grep "define USE_CACHEDB 1" $PRE/config.h; then echo test enabled; else skip_test "test skipped"; fi
+
+echo "> cat logfiles"
+cat fwd.log 
+if test -f fwd2.log; then cat fwd2.log; else echo "no fwd2.log"; fi
+if test -f fwd3.log; then cat fwd3.log; else echo "no fwd3.log"; fi
+if test -f fwd4.log; then cat fwd4.log; else echo "no fwd4.log"; fi
+cat unbound.log
+if test -f unbound2.log; then cat unbound2.log; else echo "no unbound2.log"; fi
+kill_pid $FWD_PID
+kill_pid `cat unbound.pid`
+rm -f $CONTROL_PATH/controlpipe.$CONTROL_PID

testdata/cachedb_no_store.tdir/cachedb_no_store.pre

@@ -0,0 +1,36 @@
+# #-- cachedb_no_store.pre--#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# use .tpkg.var.test for in test variable passing
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+
+PRE="../.."
+. ../common.sh
+if grep "define USE_CACHEDB 1" $PRE/config.h; then echo test enabled; else skip_test "test skipped"; fi
+
+get_random_port 2
+UNBOUND_PORT=$RND_PORT
+FWD_PORT=$(($RND_PORT + 1))
+echo "UNBOUND_PORT=$UNBOUND_PORT" >> .tpkg.var.test
+echo "FWD_PORT=$FWD_PORT" >> .tpkg.var.test
+
+# start forwarder
+get_ldns_testns
+$LDNS_TESTNS -p $FWD_PORT cachedb_no_store.testns >fwd.log 2>&1 &
+FWD_PID=$!
+echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
+
+# make config file
+CONTROL_PATH=/tmp
+CONTROL_PID=$$
+sed -e 's/@PORT\@/'$UNBOUND_PORT'/' -e 's/@TOPORT\@/'$FWD_PORT'/' -e 's?@CONTROL_PATH\@?'$CONTROL_PATH'?' -e 's/@CONTROL_PID@/'$CONTROL_PID'/' < cachedb_no_store.conf > ub.conf
+# start unbound in the background
+$PRE/unbound -d -c ub.conf >unbound.log 2>&1 &
+UNBOUND_PID=$!
+echo "UNBOUND_PID=$UNBOUND_PID" >> .tpkg.var.test
+echo "CONTROL_PATH=$CONTROL_PATH" >> .tpkg.var.test
+echo "CONTROL_PID=$CONTROL_PID" >> .tpkg.var.test
+
+cat .tpkg.var.test
+wait_ldns_testns_up fwd.log
+wait_unbound_up unbound.log

testdata/cachedb_no_store.tdir/cachedb_no_store.servfail.testns

@@ -0,0 +1,8 @@
+ENTRY_BEGIN
+MATCH opcode
+ADJUST copy_id copy_query
+REPLY QR AA SERVFAIL
+SECTION QUESTION
+txt1.example.com. IN TXT
+SECTION ANSWER
+ENTRY_END

testdata/cachedb_no_store.tdir/cachedb_no_store.test

@@ -0,0 +1,133 @@
+# #-- cachedb_no_store.test --#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# use .tpkg.var.test for in test variable passing
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+
+PRE="../.."
+. ../common.sh
+if grep "define USE_CACHEDB 1" $PRE/config.h; then echo test enabled; else skip_test "test skipped"; fi
+
+# do the test
+get_ldns_testns
+
+# query for a text record that is stored by unbound's cache and cachedb
+# in the testframe cache.
+echo "> dig txt1.example.com."
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "example text message" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+# stop the forwarder with servfail, to check the answer came from the cache
+echo "> stop ldns-testns"
+kill_pid $FWD_PID
+echo "> start ldns-testns with servfails"
+$LDNS_TESTNS -p $FWD_PORT cachedb_no_store.servfail.testns >fwd2.log 2>&1 &
+FWD_PID=$!
+echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
+wait_ldns_testns_up fwd2.log
+
+echo "> dig txt1.example.com. from unbound cache"
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "example text message" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+# clear the cache of unbound, but not cachedb testframe cache
+echo "> unbound-control flush"
+$PRE/unbound-control -c ub.conf flush_type txt1.example.com. TXT
+if test $? -ne 0; then
+	echo "wrong exit value."
+	exit 1
+else
+	echo "exit value: OK"
+fi
+
+echo "> dig txt1.example.com. from cachedb"
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "example text message" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+# start the forwarder again.
+echo "> stop ldns-testns"
+kill_pid $FWD_PID
+echo "> start ldns-testns"
+$LDNS_TESTNS -p $FWD_PORT cachedb_no_store.testns >fwd3.log 2>&1 &
+FWD_PID=$!
+echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
+wait_ldns_testns_up fwd3.log
+
+# stop unbound to flush the cachedb cache
+echo "> stop unbound"
+kill_pid `cat unbound.pid`
+
+echo ""
+echo "> config unbound with cachedb-no-store: yes"
+echo "cachedb: cachedb-no-store: yes" >> ub.conf
+
+# start unbound again.
+echo "> start unbound"
+$PRE/unbound -d -c ub.conf >unbound2.log 2>&1 &
+UNBOUND_PID=$!
+echo "UNBOUND_PID=$UNBOUND_PID" >> .tpkg.var.test
+wait_unbound_up unbound2.log
+
+echo ""
+echo "> dig txt1.example.com."
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "example text message" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+# stop the forwarder with servfail, to check the answer came from the cache
+echo "> stop ldns-testns"
+kill_pid $FWD_PID
+echo "> start ldns-testns with servfails"
+$LDNS_TESTNS -p $FWD_PORT cachedb_no_store.servfail.testns >fwd4.log 2>&1 &
+FWD_PID=$!
+echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
+wait_ldns_testns_up fwd4.log
+
+echo "> dig txt1.example.com. from unbound cache"
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "example text message" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+# clear the cache of unbound, but not cachedb testframe cache
+echo "> unbound-control flush"
+$PRE/unbound-control -c ub.conf flush_type txt1.example.com. TXT
+if test $? -ne 0; then
+	echo "wrong exit value."
+	exit 1
+else
+	echo "exit value: OK"
+fi
+
+echo "> dig txt1.example.com. from cachedb, but that has no message stored"
+dig @localhost -p $UNBOUND_PORT txt1.example.com. TXT | tee outfile
+if grep "SERVFAIL" outfile; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+exit 0

testdata/cachedb_no_store.tdir/cachedb_no_store.testns

@@ -0,0 +1,9 @@
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR AA NOERROR
+SECTION QUESTION
+txt1.example.com. IN TXT
+SECTION ANSWER
+txt1.example.com. IN TXT "example text message"
+ENTRY_END

util/config_file.c

@@ -382,6 +382,7 @@ config_create(void)
 #ifdef USE_CACHEDB
 	if(!(cfg->cachedb_backend = strdup("testframe"))) goto error_exit;
 	if(!(cfg->cachedb_secret = strdup("default"))) goto error_exit;
+	cfg->cachedb_no_store = 0;
 #ifdef USE_REDIS
 	if(!(cfg->redis_server_host = strdup("127.0.0.1"))) goto error_exit;
 	cfg->redis_server_path = NULL;
@@ -822,6 +823,9 @@ int config_set_option(struct config_file* cfg, const char* opt,
 	{ IS_NUMBER_OR_ZERO; cfg->ipsecmod_max_ttl = atoi(val); }
 	else S_YNO("ipsecmod-strict:", ipsecmod_strict)
 #endif
+#ifdef USE_CACHEDB
+	else S_YNO("cachedb-no-store:", cachedb_no_store)
+#endif /* USE_CACHEDB */
 	else if(strcmp(opt, "define-tag:") ==0) {
 		return config_add_tag(cfg, val);
 	/* val_sig_skew_min, max and val_max_restart are copied into val_env
@@ -1310,6 +1314,7 @@ config_get_option(struct config_file* cfg, const char* opt,
 #ifdef USE_CACHEDB
 	else O_STR(opt, "backend", cachedb_backend)
 	else O_STR(opt, "secret-seed", cachedb_secret)
+	else O_YNO(opt, "cachedb-no-store", cachedb_no_store)
 #ifdef USE_REDIS
 	else O_STR(opt, "redis-server-host", redis_server_host)
 	else O_DEC(opt, "redis-server-port", redis_server_port)

util/config_file.h

@@ -701,6 +701,8 @@ struct config_file {
 	char* cachedb_backend;
 	/** secret seed for hash key calculation */
 	char* cachedb_secret;
+	/** cachedb that does not store, but only reads from database, if on */
+	int cachedb_no_store;
 #ifdef USE_REDIS
 	/** redis server's IP address or host name */
 	char* redis_server_host;

util/configlexer.lex

@@ -558,6 +558,7 @@ ipsecmod-strict{COLON}		{ YDVAR(1, VAR_IPSECMOD_STRICT) }
 cachedb{COLON}			{ YDVAR(0, VAR_CACHEDB) }
 backend{COLON}			{ YDVAR(1, VAR_CACHEDB_BACKEND) }
 secret-seed{COLON}		{ YDVAR(1, VAR_CACHEDB_SECRETSEED) }
+cachedb-no-store{COLON}		{ YDVAR(1, VAR_CACHEDB_NO_STORE) }
 redis-server-host{COLON}	{ YDVAR(1, VAR_CACHEDB_REDISHOST) }
 redis-server-port{COLON}	{ YDVAR(1, VAR_CACHEDB_REDISPORT) }
 redis-server-path{COLON}	{ YDVAR(1, VAR_CACHEDB_REDISPATH) }

util/configparser.y

@@ -199,7 +199,7 @@ extern struct config_parser_state* cfg_parser;
 %token VAR_INTERFACE_ACTION VAR_INTERFACE_VIEW VAR_INTERFACE_TAG
 %token VAR_INTERFACE_TAG_ACTION VAR_INTERFACE_TAG_DATA
 %token VAR_PROXY_PROTOCOL_PORT VAR_STATISTICS_INHIBIT_ZERO
-%token VAR_HARDEN_UNKNOWN_ADDITIONAL VAR_DISABLE_EDNS_DO
+%token VAR_HARDEN_UNKNOWN_ADDITIONAL VAR_DISABLE_EDNS_DO VAR_CACHEDB_NO_STORE
 
 %%
 toplevelvars: /* empty */ | toplevelvars toplevelvar ;
@@ -3712,7 +3712,7 @@ contents_cachedb: contents_cachedb content_cachedb
 content_cachedb: cachedb_backend_name | cachedb_secret_seed |
 	redis_server_host | redis_server_port | redis_timeout |
 	redis_expire_records | redis_server_path | redis_server_password |
-	redis_logical_db
+	cachedb_no_store | redis_logical_db
 	;
 cachedb_backend_name: VAR_CACHEDB_BACKEND STRING_ARG
 	{
@@ -3738,6 +3738,19 @@ cachedb_secret_seed: VAR_CACHEDB_SECRETSEED STRING_ARG
 	#endif
 	}
 	;
+cachedb_no_store: VAR_CACHEDB_NO_STORE STRING_ARG
+	{
+	#ifdef USE_CACHEDB
+		OUTYY(("P(cachedb_no_store:%s)\n", $2));
+		if(strcmp($2, "yes") != 0 && strcmp($2, "no") != 0)
+			yyerror("expected yes or no.");
+		else cfg_parser->cfg->cachedb_no_store = (strcmp($2, "yes")==0);
+	#else
+		OUTYY(("P(Compiled without cachedb, ignoring)\n"));
+	#endif
+		free($2);
+	}
+	;
 redis_server_host: VAR_CACHEDB_REDISHOST STRING_ARG
 	{
 	#if defined(USE_CACHEDB) && defined(USE_REDIS)