Unjostable queries for configured upstreams

services/mesh.c

@@ -43,6 +43,8 @@
  * send back to clients.
  */
 #include "config.h"
+#include "iterator/iter_hints.h"
+#include "iterator/iter_fwd.h"
 #include "services/mesh.h"
 #include "services/outbound_list.h"
 #include "services/cache/dns.h"
@@ -275,37 +277,60 @@ mesh_delete_all(struct mesh_area* mesh)
 int mesh_make_new_space(struct mesh_area* mesh, sldns_buffer* qbuf)
 {
 	struct mesh_state* m = mesh->jostle_first;
-	/* free space is available */
-	if(mesh->num_reply_states < mesh->max_reply_states)
+	if(mesh->num_reply_states < mesh->max_reply_states) {
+		/* free space is available */
 		return 1;
+	}
 	/* try to kick out a jostle-list item */
 	if(m && m->reply_list && m->list_select == mesh_jostle_list) {
-		/* how old is it? */
 		struct timeval age;
+		struct iter_hints_stub* stub = NULL;
+		struct delegpt* fwd = NULL;
+		/* how old is it? */
 		timeval_subtract(&age, mesh->env->now_tv,
 			&m->reply_list->start_time);
-		if(timeval_smaller(&mesh->jostle_max, &age)) {
-			/* its a goner */
-			log_nametypeclass(VERB_ALGO, "query jostled out to "
-				"make space for a new one",
-				m->s.qinfo.qname, m->s.qinfo.qtype,
-				m->s.qinfo.qclass);
-			/* backup the query */
-			if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
-			/* notify supers */
-			if(m->super_set.count > 0) {
-				verbose(VERB_ALGO, "notify supers of failure");
-				m->s.return_msg = NULL;
-				m->s.return_rcode = LDNS_RCODE_SERVFAIL;
-				mesh_walk_supers(mesh, m);
+		if(!timeval_smaller(&mesh->jostle_max, &age)
+			|| m->has_configured_upstream) {
+			/* can't jostle out; still fresh or has configured
+			 * upstreams */
+			return 0;
+		}
+		if((stub=hints_lookup_stub(mesh->env->hints,
+			m->s.qinfo.qname, m->s.qinfo.qclass, NULL, 0))
+			|| (fwd=forwards_find(mesh->env->fwds,
+			m->s.qinfo.qname, m->s.qinfo.qclass, 0))) {
+			/* can't jostle out; there is a configured upstream
+			 * for this */
+			m->has_configured_upstream = 1;
+			if(stub) {
+				lock_rw_unlock(&mesh->env->hints->lock);
 			}
-			mesh->stats_jostled ++;
-			mesh_state_delete(&m->s);
-			/* restore the query - note that the qinfo ptr to
-			 * the querybuffer is then correct again. */
-			if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
-			return 1;
+			if(fwd) {
+				lock_rw_unlock(&mesh->env->fwds->lock);
+			}
+			return 0;
 		}
+		/* its a goner; older than jostle-timeout and there are no
+		 * configured upstreams that could give it 'persistence' */
+		log_nametypeclass(VERB_ALGO, "query jostled out to "
+			"make space for a new one",
+			m->s.qinfo.qname, m->s.qinfo.qtype,
+			m->s.qinfo.qclass);
+		/* backup the query */
+		if(qbuf) sldns_buffer_copy(mesh->qbuf_bak, qbuf);
+		/* notify supers */
+		if(m->super_set.count > 0) {
+			verbose(VERB_ALGO, "notify supers of failure");
+			m->s.return_msg = NULL;
+			m->s.return_rcode = LDNS_RCODE_SERVFAIL;
+			mesh_walk_supers(mesh, m);
+		}
+		mesh->stats_jostled ++;
+		mesh_state_delete(&m->s);
+		/* restore the query - note that the qinfo ptr to
+		 * the querybuffer is then correct again. */
+		if(qbuf) sldns_buffer_copy(qbuf, mesh->qbuf_bak);
+		return 1;
 	}
 	/* no space for new item */
 	return 0;

services/mesh.h

@@ -206,6 +206,12 @@ struct mesh_state {
 	/** pointer to this state for uniqueness or NULL */
 	struct mesh_state* unique;
 
+	/** if the qname of this mesh state will go out to one of the
+	 *  configured upstreams (stub-zone or forward-zone).
+	 *  Only used when trying to make space (jostle) for new client
+	 *  queries. */
+	int has_configured_upstream;
+
 	/** true if replies have been sent out (at end for alignment) */
 	uint8_t replies_sent;
 };

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.conf

@@ -0,0 +1,27 @@
+server:
+        num-threads: 1
+	verbosity: 5
+	use-syslog: no
+	directory: ""
+	pidfile: "unbound.pid"
+	chroot: ""
+	username: ""
+	do-not-query-localhost: no
+	use-caps-for-id: no
+	port: @SERVER_PORT@
+	interface: 127.0.0.1
+
+        num-queries-per-thread: 2
+        infra-cache-min-rtt: 1000
+
+stub-zone:
+	name: "a.slow"
+	stub-addr: 127.0.0.1@@SLOW_STUB_PORT@
+
+stub-zone:
+	name: "b.slow"
+	stub-addr: 127.0.0.1@@SLOW_STUB_PORT@
+
+stub-zone:
+	name: "c.fast"
+	stub-addr: 127.0.0.1@@FAST_STUB_PORT@

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.dsc

@@ -0,0 +1,16 @@
+BaseName: mesh_jostle_priority
+Version: 1.0
+Description: Check that mesh items will not be jostled if there is a explicitly configured upstream
+CreationDate: Tue 3 Dec 11:00:00 CEST 2024
+Maintainer:
+Category:
+Component:
+CmdDepends:
+Depends:
+Help:
+Pre: mesh_jostle_priority.pre
+Post: mesh_jostle_priority.post
+Test: mesh_jostle_priority.test
+AuxFiles:
+Passed:
+Failure:

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.post

@@ -0,0 +1,12 @@
+# #-- mesh_jostle_priority.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
+. ../common.sh
+kill_from_pidfile "unbound.pid"
+kill_pid $SLOW_STUB_PID
+kill_pid $FAST_STUB_PID
+cat unbound.log

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.pre

@@ -0,0 +1,36 @@
+# #-- mesh_jostle_priority.pre--#
+PRE="../.."
+. ../common.sh
+
+get_random_port 3
+SERVER_PORT=$RND_PORT
+SLOW_STUB_PORT=$(($RND_PORT + 1))
+FAST_STUB_PORT=$(($RND_PORT + 2))
+echo "SERVER_PORT=$SERVER_PORT" >> .tpkg.var.test
+echo "SLOW_STUB_PORT=$SLOW_STUB_PORT" >> .tpkg.var.test
+echo "FAST_STUB_PORT=$FAST_STUB_PORT" >> .tpkg.var.test
+
+# start stub
+get_ldns_testns
+$LDNS_TESTNS -v -p $SLOW_STUB_PORT mesh_jostle_priority.testns >stub_slow.log 2>&1 &
+SLOW_STUB_PID=$!
+echo "SLOW_STUB_PID=$SLOW_STUB_PID" >> .tpkg.var.test
+
+$LDNS_TESTNS -v -p $FAST_STUB_PORT mesh_jostle_priority.testns >stub_fast.log 2>&1 &
+FAST_STUB_PID=$!
+echo "FAST_STUB_PID=$FAST_STUB_PID" >> .tpkg.var.test
+
+# make config file
+sed \
+	-e 's/@SERVER_PORT\@/'$SERVER_PORT'/' \
+	-e 's/@SLOW_STUB_PORT\@/'$SLOW_STUB_PORT'/' \
+	-e 's/@FAST_STUB_PORT\@/'$FAST_STUB_PORT'/' \
+	< mesh_jostle_priority.conf > ub.conf
+
+# start unbound in the background
+$PRE/unbound -d -c ub.conf > unbound.log 2>&1 &
+
+cat .tpkg.var.test
+wait_ldns_testns_up stub_slow.log
+wait_ldns_testns_up stub_fast.log
+wait_unbound_up unbound.log

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.test

@@ -0,0 +1,31 @@
+# #-- mesh_jostle_priority.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
+
+get_make
+(cd $PRE; $MAKE streamtcp)
+
+teststep "Fire up and forget the two slow queries"
+$PRE/streamtcp -f 127.0.0.1@$SERVER_PORT -u -n a.slow. A IN b.slow. A IN
+if test "$?" -ne 0
+then
+	echo "error with streamtcp"
+	exit 1
+fi
+
+teststep "Let time pass so that queries can be jostled based on time"
+sleep 1
+
+teststep "Check that the fast query is dropped because the slow ones have explicitly configured upstreams"
+dig @127.0.0.1 -p $SERVER_PORT +retry=0 +timeout=1 c.fast. > outfile
+if grep "10.20.30.40" outfile
+then
+	cat outfile
+	echo "Did not get a drop"
+	exit 1
+fi
+exit 0

testdata/mesh_jostle_priority.tdir/mesh_jostle_priority.testns

@@ -0,0 +1,35 @@
+$ORIGIN slow.
+$TTL 3600
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+REPLY QR AA NOERROR
+ADJUST copy_id sleep=5
+SECTION QUESTION
+a	IN	A
+SECTION ANSWER
+a	IN	A 1.1.1.1
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+REPLY QR AA NOERROR
+ADJUST copy_id sleep=5
+SECTION QUESTION
+b	IN	A
+SECTION ANSWER
+b	IN	A 2.2.2.2
+ENTRY_END
+
+$ORIGIN fast.
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+REPLY QR AA NOERROR
+ADJUST copy_id
+SECTION QUESTION
+c	IN	A
+SECTION ANSWER
+c	IN	A	10.20.30.40
+ENTRY_END
+