- Fix to detect that no IPv6 support means that IPv6 addresses are

  useless for delegation point lookups.

diff --git a/daemon/cachedump.c b/daemon/cachedump.c
index b1ce53b596b66095d18dec20964d683af73a98a1..8a8694c4291d2679f028f1cbcfcbb2d60077485e 100644 (file)
--- a/daemon/cachedump.c
+++ b/daemon/cachedump.c
@@ -51,6 +51,7 @@
 #include "util/regional.h"
 #include "util/net_help.h"
 #include "util/data/dname.h"
+#include "util/config_file.h"
 #include "iterator/iterator.h"
 #include "iterator/iter_delegpt.h"
 #include "iterator/iter_utils.h"
@@ -854,7 +855,8 @@ int print_deleg_lookup(RES* ssl, struct worker* worker, uint8_t* nm,
                                "cache; goes to configured roots\n");
                }
                /* go up? */
-               if(iter_dp_is_useless(&qinfo, BIT_RD, dp)) {
+               if(iter_dp_is_useless(&qinfo, BIT_RD, dp,
+                       worker->env.cfg->do_ip4, worker->env.cfg->do_ip6)) {
                        print_dp_main(ssl, dp, msg);
                        print_dp_details(ssl, worker, dp);
                        if(!ssl_printf(ssl, "cache delegation was "

diff --git a/doc/Changelog b/doc/Changelog
index e0793c16db492f19cd2ec4ea7b06c11b077f85ac..b968383aa713ab6e97370dd140f6bd75f276a55f 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,7 @@
+25 February 2022: Wouter
+       - Fix to detect that no IPv6 support means that IPv6 addresses are
+         useless for delegation point lookups.
+
 18 February 2022: Wouter
        - Fix that address not available is squelched from the logs for
          udp connect failures. It is visible on verbosity 4 and more.

diff --git a/iterator/iter_utils.c b/iterator/iter_utils.c
index 2482a1f40f03f057073081af172c456f8ae98e28..f3bea46d6c95542a80e799e2c50edf00b27fd50d 100644 (file)
--- a/iterator/iter_utils.c
+++ b/iterator/iter_utils.c
@@ -743,9 +743,10 @@ iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
 
 int
 iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags,
-       struct delegpt* dp)
+       struct delegpt* dp, int supports_ipv4, int supports_ipv6)
 {
        struct delegpt_ns* ns;
+       struct delegpt_addr* a;
        /* check:
         *      o RD qflag is on.
         *      o no addresses are provided.
@@ -758,13 +759,24 @@ iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags,
         */
        if(!(qflags&BIT_RD))
                return 0;
-       /* either available or unused targets */
-       if(dp->usable_list || dp->result_list)
-               return 0;
+       /* either available or unused targets,
+        * if they exist, the dp is not useless. */
+       for(a = dp->usable_list; a; a = a->next_usable) {
+               if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4)
+                       return 0;
+               else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6)
+                       return 0;
+       }
+       for(a = dp->result_list; a; a = a->next_result) {
+               if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4)
+                       return 0;
+               else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6)
+                       return 0;
+       }
 
        /* see if query is for one of the nameservers, which is glue */
-       if( (qinfo->qtype == LDNS_RR_TYPE_A ||
-               qinfo->qtype == LDNS_RR_TYPE_AAAA) &&
+       if( ((qinfo->qtype == LDNS_RR_TYPE_A && supports_ipv4) ||
+               (qinfo->qtype == LDNS_RR_TYPE_AAAA && supports_ipv6)) &&
                dname_subdomain_c(qinfo->qname, dp->name) &&
                delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len))
                return 1;

diff --git a/iterator/iter_utils.h b/iterator/iter_utils.h
index 0a40916c0e0238fb672c7d545de7687b2b001442..c0e5181573f529424143fc07808a13adfcf21f7b 100644 (file)
--- a/iterator/iter_utils.h
+++ b/iterator/iter_utils.h
@@ -175,10 +175,14 @@ void iter_mark_pside_cycle_targets(struct module_qstate* qstate,
  * @param qinfo: query name and type
  * @param qflags: query flags with RD flag
  * @param dp: delegpt to check.
+ * @param supports_ipv4: if we support ipv4 for lookups to the target.
+ *     if not, then the IPv4 addresses are useless.
+ * @param supports_ipv6: if we support ipv6 for lookups to the target.
+ *     if not, then the IPv6 addresses are useless.
  * @return true if dp is useless.
  */
 int iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, 
-       struct delegpt* dp);
+       struct delegpt* dp, int supports_ipv4, int supports_ipv6);
 
 /**
  * See if qname has DNSSEC needs.  This is true if there is a trust anchor above

diff --git a/iterator/iterator.c b/iterator/iterator.c
index 320d2e8fc9f35706bdbb6ca5fdd66de6ba609329..cf4f1beac34a339f8b7778e7735b1730db013a69 100644 (file)
--- a/iterator/iterator.c
+++ b/iterator/iterator.c
@@ -1547,7 +1547,7 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
                 * same server reply) if useless-checked.
                 */
                if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, 
-                       iq->dp)) {
+                       iq->dp, ie->supports_ipv4, ie->supports_ipv6)) {
                        struct delegpt* retdp = NULL;
                        if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, iq->qchase.qclass, &retdp)) {
                                if(retdp) {

diff --git a/testdata/iter_dp_ip6useless.rpl b/testdata/iter_dp_ip6useless.rpl
new file mode 100644 (file)
index 0000000..9a7746e
--- /dev/null
+++ b/testdata/iter_dp_ip6useless.rpl
@@ -0,0 +1,168 @@
+; config options
+server:
+       do-ip6: no
+       target-fetch-policy: "0 0 0 0 0"
+       qname-minimisation: no
+stub-zone:
+       name: "."
+       stub-addr: 193.0.14.129         # K.ROOT-SERVERS.NET.
+CONFIG_END
+
+SCENARIO_BEGIN Test iterator when doip6 is no and dp is useless with only ip6
+
+; K.ROOT-SERVERS.NET.
+RANGE_BEGIN 0 100
+       ADDRESS 193.0.14.129 
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+. IN NS
+SECTION ANSWER
+. IN NS        K.ROOT-SERVERS.NET.
+SECTION ADDITIONAL
+K.ROOT-SERVERS.NET.    IN      A       193.0.14.129
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode subdomain
+ADJUST copy_id copy_query
+REPLY QR NOERROR
+SECTION QUESTION
+com. IN NS
+SECTION AUTHORITY
+com.   IN NS   a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.    IN      A       192.5.6.30
+ENTRY_END
+RANGE_END
+
+; a.gtld-servers.net.
+RANGE_BEGIN 0 100
+       ADDRESS 192.5.6.30
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+com. IN NS
+SECTION ANSWER
+com.   IN NS   a.gtld-servers.net.
+SECTION ADDITIONAL
+a.gtld-servers.net.    IN      A       192.5.6.30
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode subdomain
+ADJUST copy_id copy_query
+REPLY QR NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION AUTHORITY
+example.com.   IN NS   ns.example.com.
+SECTION ADDITIONAL
+; short TTL here, so it can expire
+ns.example.com.        1       IN      A       1.2.3.4
+ns.example.com.        100     IN      AAAA    ::53
+ENTRY_END
+RANGE_END
+
+; ns.example.com.
+RANGE_BEGIN 0 100
+       ADDRESS 1.2.3.4
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+example.com. IN NS
+SECTION ANSWER
+example.com.   IN NS   ns.example.com.
+SECTION ADDITIONAL
+; short TTL here, so it can expire
+ns.example.com.        1       IN      A       1.2.3.4
+ns.example.com.        100     IN      AAAA    ::53
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+ns.example.com. IN A
+SECTION ANSWER
+; short TTL
+ns.example.com.        1       IN      A       1.2.3.4
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+ns.example.com. IN AAAA
+SECTION ANSWER
+ns.example.com.                IN      AAAA    ::53
+ENTRY_END
+
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A  10.20.30.40
+ENTRY_END
+
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR NOERROR
+SECTION QUESTION
+mail.example.com. IN A
+SECTION ANSWER
+mail.example.com. IN A 10.20.30.50
+ENTRY_END
+RANGE_END
+
+STEP 1 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+www.example.com. IN A
+ENTRY_END
+
+; recursion happens here.
+STEP 10 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH all
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+www.example.com. IN A
+SECTION ANSWER
+www.example.com. IN A  10.20.30.40
+ENTRY_END
+
+STEP 20 TIME_PASSES ELAPSE 5.0
+
+STEP 30 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+mail.example.com. IN A
+ENTRY_END
+
+STEP 40 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH all
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+mail.example.com. IN A
+SECTION ANSWER
+mail.example.com. IN A 10.20.30.50
+ENTRY_END
+
+SCENARIO_END