- Get ready for the DNS flag day: remove EDNS lame procedure, do not re-query

without EDNS after timeout.


git-svn-id: file:///svn/unbound/trunk@5037 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,3 +1,7 @@
+16 January 2018: Ralph
+	- Get ready for the DNS flag day: remove EDNS lame procedure, do not
+	  re-query without EDNS after timeout.
+
 15 January 2018: Wouter
 	- In the out of order processing, reset byte count for (potential)
 	  partial read.

services/outside_network.c

@@ -1506,7 +1506,6 @@ serviced_delete(struct serviced_query* sq)
 		/* clear up the pending query */
 		if(sq->status == serviced_query_UDP_EDNS ||
 			sq->status == serviced_query_UDP ||
-			sq->status == serviced_query_PROBE_EDNS ||
 			sq->status == serviced_query_UDP_EDNS_FRAG ||
 			sq->status == serviced_query_UDP_EDNS_fallback) {
 			struct pending* p = (struct pending*)sq->pending;
@@ -1633,15 +1632,7 @@ serviced_udp_send(struct serviced_query* sq, sldns_buffer* buff)
 	sq->last_rtt = rtt;
 	verbose(VERB_ALGO, "EDNS lookup known=%d vs=%d", edns_lame_known, vs);
 	if(sq->status == serviced_initial) {
-		if(edns_lame_known == 0 && rtt > 5000 && rtt < 10001) {
-			/* perform EDNS lame probe - check if server is
-			 * EDNS lame (EDNS queries to it are dropped) */
-			verbose(VERB_ALGO, "serviced query: send probe to see "
-				" if use of EDNS causes timeouts");
-			/* even 700 msec may be too small */
-			rtt = 1000;
-			sq->status = serviced_query_PROBE_EDNS;
-		} else if(vs != -1) {
+		if(vs != -1) {
 			sq->status = serviced_query_UDP_EDNS;
 		} else { 	
 			sq->status = serviced_query_UDP; 
@@ -1978,12 +1969,6 @@ serviced_udp_callback(struct comm_point* c, void* arg, int error,
 	sq->pending = NULL; /* removed after callback */
 	if(error == NETEVENT_TIMEOUT) {
 		int rto = 0;
-		if(sq->status == serviced_query_PROBE_EDNS) {
-			/* non-EDNS probe failed; we do not know its status,
-			 * keep trying with EDNS, timeout may not be caused
-			 * by EDNS. */
-			sq->status = serviced_query_UDP_EDNS;
-		}
 		if(sq->status == serviced_query_UDP_EDNS && sq->last_rtt < 5000) {
 			/* fallback to 1480/1280 */
 			sq->status = serviced_query_UDP_EDNS_FRAG;
@@ -2047,18 +2032,6 @@ serviced_udp_callback(struct comm_point* c, void* arg, int error,
 			serviced_callbacks(sq, NETEVENT_CLOSED, c, rep);
 		}
 		return 0;
-	    } else if(sq->status == serviced_query_PROBE_EDNS) {
-		/* probe without EDNS succeeds, so we conclude that this
-		 * host likely has EDNS packets dropped */
-		log_addr(VERB_DETAIL, "timeouts, concluded that connection to "
-			"host drops EDNS packets", &sq->addr, sq->addrlen);
-		/* only store noEDNS in cache if domain is noDNSSEC */
-		if(!sq->want_dnssec)
-		  if(!infra_edns_update(outnet->infra, &sq->addr, sq->addrlen,
-			sq->zone, sq->zonelen, -1, (time_t)now.tv_sec)) {
-			log_err("Out of memory caching no edns for host");
-		  }
-		sq->status = serviced_query_UDP;
 	    } else if(sq->status == serviced_query_UDP_EDNS && 
 		!sq->edns_lame_known) {
 		/* now we know that edns queries received answers store that */
@@ -2539,7 +2512,6 @@ serviced_get_mem(struct serviced_query* sq)
 		s += sizeof(*sb);
 	if(sq->status == serviced_query_UDP_EDNS ||
 		sq->status == serviced_query_UDP ||
-		sq->status == serviced_query_PROBE_EDNS ||
 		sq->status == serviced_query_UDP_EDNS_FRAG ||
 		sq->status == serviced_query_UDP_EDNS_fallback) {
 		s += sizeof(struct pending);

services/outside_network.h

@@ -359,8 +359,6 @@ struct serviced_query {
 		serviced_query_TCP_EDNS,
 		/** TCP without EDNS sent */
 		serviced_query_TCP,
-		/** probe to test EDNS lameness (EDNS is dropped) */
-		serviced_query_PROBE_EDNS,
 		/** probe to test noEDNS0 (EDNS gives FORMERRorNOTIMP) */
 		serviced_query_UDP_EDNS_fallback,
 		/** probe to test TCP noEDNS0 (EDNS gives FORMERRorNOTIMP) */

testdata/edns_cache.tdir/edns_cache.conf

@@ -12,9 +12,6 @@ server:
 stub-zone:
 	name: "example.net"
 	stub-addr: "127.0.0.1@@STUB2_PORT@"
-stub-zone:
-	name: "example.com"
-	stub-addr: "127.0.0.1@@STUB2_PORT@"
 # a k a root hints
 stub-zone:
 	name: "."

testdata/edns_cache.tdir/edns_cache.stub1

@@ -17,17 +17,6 @@ SECTION ADDITIONAL
 root.server.	IN	A	127.0.0.1
 ENTRY_END
 
-; referral to example.com
-ENTRY_BEGIN
-MATCH opcode subdomain
-REPLY QR NOERROR
-ADJUST copy_id copy_query
-SECTION QUESTION
-example.com.	IN	A
-SECTION AUTHORITY
-example.com.	IN 	NS	netdns.example.net.
-ENTRY_END
-
 ; referral to example.net
 ENTRY_BEGIN
 MATCH opcode subdomain

testdata/edns_cache.tdir/edns_cache.stub2

@@ -1,5 +1,5 @@
 ; nameserver test file
-$ORIGIN example.com.
+$ORIGIN example.net.
 $TTL 3600
 
 ENTRY_BEGIN
@@ -7,9 +7,9 @@ MATCH opcode qtype qname noedns
 REPLY QR AA NOERROR
 ADJUST copy_id
 SECTION QUESTION
-www.example.com.	IN	A
+www.example.net.	IN	A
 SECTION ANSWER
-www.example.com.	IN	A	10.20.30.40
+www.example.net.	IN	A	10.20.30.40
 ENTRY_END
 
 ENTRY_BEGIN

testdata/edns_cache.tdir/edns_cache.test

@@ -11,8 +11,8 @@ PRE="../.."
 # do the test
 echo "> dig netdns.example.net."
 dig @::1 -p $UNBOUND_PORT netdns.example.net. | tee outfile
-echo "> dig www.example.com."
-dig @::1 -p $UNBOUND_PORT www.example.com. | tee outfile
+echo "> dig www.example.net."
+dig @::1 -p $UNBOUND_PORT www.example.net. | tee outfile
 echo "> cat stub1.log"
 cat stub1.log 
 echo "> cat stub2.log"

testdata/edns_lame.tdir/edns_lame.conf

@@ -1,15 +0,0 @@
-server:
-	verbosity: 2
-	# num-threads: 1
-	interface: 127.0.0.1
-	port: @PORT@
-	use-syslog: no
-	directory: ""
-	pidfile: "unbound.pid"
-	chroot: ""
-	username: ""
-	do-not-query-localhost: no
-forward-zone:
-	name: "."
-	forward-addr: "127.0.0.1@@TOPORT@"
-

testdata/edns_lame.tdir/edns_lame.dsc

@@ -1,16 +0,0 @@
-BaseName: edns_lame
-Version: 1.0
-Description: Forward UDP but EDNS packets time out
-CreationDate: Mon Sep 29 16:39:15 CEST 2008
-Maintainer: dr. W.C.A. Wijngaards
-Category: 
-Component:
-CmdDepends: 
-Depends: 
-Help:
-Pre: edns_lame.pre
-Post: edns_lame.post
-Test: edns_lame.test
-AuxFiles: 
-Passed:
-Failure:

testdata/edns_lame.tdir/edns_lame.post

@@ -1,10 +0,0 @@
-# #-- edns_lame.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_pid $FWD_PID
-kill_pid $UNBOUND_PID

testdata/edns_lame.tdir/edns_lame.pre

@@ -1,30 +0,0 @@
-# #-- edns_lame.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
-
-. ../common.sh
-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 $FWD_PORT -v edns_lame.testns >fwd.log 2>&1 &
-FWD_PID=$!
-echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
-
-# make config file
-sed -e 's/@PORT\@/'$UNBOUND_PORT'/' -e 's/@TOPORT\@/'$FWD_PORT'/' < edns_lame.conf > ub.conf
-# start unbound in the background
-PRE="../.."
-$PRE/unbound -d -vvvv -c ub.conf >unbound.log 2>&1 &
-UNBOUND_PID=$!
-echo "UNBOUND_PID=$UNBOUND_PID" >> .tpkg.var.test
-
-cat .tpkg.var.test
-wait_ldns_testns_up fwd.log
-wait_unbound_up unbound.log

testdata/edns_lame.tdir/edns_lame.test

@@ -1,24 +0,0 @@
-# #-- edns_lame.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="../.."
-# do the test
-echo "> dig www.example.com."
-dig @localhost -p $UNBOUND_PORT www.example.com. | tee outfile
-echo "> dig www.example.com."
-dig @localhost -p $UNBOUND_PORT www.example.com. | tee outfile
-echo "> cat logfiles"
-cat fwd.log 
-cat unbound.log
-echo "> check answer"
-if grep "10.20.30.40" outfile; then
-	echo "OK"
-else
-	echo "Not OK"
-	exit 1
-fi
-
-exit 0

testdata/edns_lame.tdir/edns_lame.testns

@@ -1,14 +0,0 @@
-; nameserver test file
-$ORIGIN example.com.
-$TTL 3600
-
-ENTRY_BEGIN
-MATCH opcode qtype qname noedns
-REPLY QR AA NOERROR
-ADJUST copy_id
-SECTION QUESTION
-www	IN	A
-SECTION ANSWER
-www	IN	A	10.20.30.40
-ENTRY_END
-