- ttl-zero-cacherep, Responses in the last second of their cache TTL,

  get an extra second. That makes the TTL not 0, since they are from
  cache and can be cached by the client.

diff --git a/cachedb/cachedb.c b/cachedb/cachedb.c
index eca3b7cb75cd56a39278a035c5bdefd71537e2a9..24f458e8f54e4d9abd22c9c93052eb01cd08d185 100644 (file)
--- a/cachedb/cachedb.c
+++ b/cachedb/cachedb.c
@@ -419,7 +419,7 @@ prep_data(struct module_qstate* qstate, struct sldns_buffer* buf)
                        qstate->return_msg->rep);
        if(!reply_info_answer_encode(&qstate->return_msg->qinfo,
                qstate->return_msg->rep, 0, qstate->query_flags,
-               buf, 0, 1, qstate->env->scratch, 65535, &edns, 1, 0))
+               buf, 0, 1, qstate->env->scratch, 65535, &edns, 1, 0, 1))
                return 0;
 
        /* TTLs in the return_msg are relative to time(0) so we have to

diff --git a/daemon/worker.c b/daemon/worker.c
index 713de316373aedd018fae774d474cd6a32a28a74..7bce4d5a1b26ed653ad7da17e8180aaa6f93206d 100644 (file)
--- a/daemon/worker.c
+++ b/daemon/worker.c
@@ -564,7 +564,7 @@ answer_norec_from_cache(struct worker* worker, struct query_info* qinfo,
        }
        if(!reply_info_answer_encode(&msg->qinfo, msg->rep, id, flags,
                repinfo->c->buffer, 0, 1, worker->scratchpad,
-               udpsize, edns, (int)(edns->bits & EDNS_DO), secure)) {
+               udpsize, edns, (int)(edns->bits & EDNS_DO), secure, 1)) {
                if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, NULL,
                        LDNS_RCODE_SERVFAIL, edns, repinfo, worker->scratchpad,
                        worker->env.now_tv))
@@ -802,7 +802,7 @@ answer_from_cache(struct worker* worker, struct query_info* qinfo,
                if(!reply_info_answer_encode(qinfo, encode_rep, id, flags,
                        repinfo->c->buffer, timenow, 1, worker->scratchpad,
                        udpsize, edns, (int)(edns->bits & EDNS_DO),
-                       *is_secure_answer)) {
+                       *is_secure_answer, 1)) {
                        if(!inplace_cb_reply_servfail_call(&worker->env, qinfo,
                                NULL, NULL, LDNS_RCODE_SERVFAIL, edns, repinfo,
                                worker->scratchpad, worker->env.now_tv))

diff --git a/services/authzone.c b/services/authzone.c
index 6f6c55d4397dedbc6d1ccb8c916275d62a88945b..90a1e4cb2f2a648413322eb5818f7b35bc78cb7d 100644 (file)
--- a/services/authzone.c
+++ b/services/authzone.c
@@ -3542,7 +3542,7 @@ auth_answer_encode(struct query_info* qinfo, struct module_env* env,
                *(uint16_t*)sldns_buffer_begin(buf),
                sldns_buffer_read_u16_at(buf, 2),
                buf, 0, 0, temp, udpsize, edns,
-               (int)(edns->bits&EDNS_DO), 0)) {
+               (int)(edns->bits&EDNS_DO), 0, 0)) {
                error_encode(buf, (LDNS_RCODE_SERVFAIL|BIT_AA), qinfo,
                        *(uint16_t*)sldns_buffer_begin(buf),
                        sldns_buffer_read_u16_at(buf, 2), edns);

diff --git a/services/localzone.c b/services/localzone.c
index d21e0c48aedb8a72793487787de6ec3a42df51fb..5314319aaff4bd0247f2c52aab3dbfa15f0374d6 100644 (file)
--- a/services/localzone.c
+++ b/services/localzone.c
@@ -1322,7 +1322,7 @@ local_encode(struct query_info* qinfo, struct module_env* env,
        if(!inplace_cb_reply_local_call(env, qinfo, NULL, &rep, rcode, edns,
                repinfo, temp, env->now_tv) || !reply_info_answer_encode(qinfo, &rep,
                *(uint16_t*)sldns_buffer_begin(buf), sldns_buffer_read_u16_at(buf, 2),
-               buf, 0, 0, temp, udpsize, edns, (int)(edns->bits&EDNS_DO), 0)) {
+               buf, 0, 0, temp, udpsize, edns, (int)(edns->bits&EDNS_DO), 0, 0)) {
                error_encode(buf, (LDNS_RCODE_SERVFAIL|BIT_AA), qinfo,
                        *(uint16_t*)sldns_buffer_begin(buf),
                        sldns_buffer_read_u16_at(buf, 2), edns);

diff --git a/services/mesh.c b/services/mesh.c
index 156cde79198d5ba57eae7b67c4dc574d7d54f8f2..f864437b2d21dfd361cf02b18a3ee97fb1316bdd 100644 (file)
--- a/services/mesh.c
+++ b/services/mesh.c
@@ -1263,7 +1263,7 @@ mesh_do_callback(struct mesh_state* m, int rcode, struct reply_info* rep,
                        !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
                        r->qflags, r->buf, 0, 1,
                        m->s.env->scratch, udp_size, &r->edns,
-                       (int)(r->edns.bits & EDNS_DO), secure))
+                       (int)(r->edns.bits & EDNS_DO), secure, 0))
                {
                        fptr_ok(fptr_whitelist_mesh_cb(r->cb));
                        (*r->cb)(r->cb_arg, LDNS_RCODE_SERVFAIL, r->buf,
@@ -1451,7 +1451,7 @@ mesh_send_reply(struct mesh_state* m, int rcode, struct reply_info* rep,
                        !reply_info_answer_encode(&m->s.qinfo, rep, r->qid,
                        r->qflags, r_buffer, 0, 1, m->s.env->scratch,
                        udp_size, &r->edns, (int)(r->edns.bits & EDNS_DO),
-                       secure))
+                       secure, 0))
                {
                        if(!inplace_cb_reply_servfail_call(m->s.env, &m->s.qinfo, &m->s,
                        rep, LDNS_RCODE_SERVFAIL, &r->edns, &r->query_reply, m->s.region, &r->start_time))

diff --git a/services/rpz.c b/services/rpz.c
index 3b92ee53837e4a307d41480e22962054af8a5e21..162881c2face02d276facbcea840f7277705181c 100644 (file)
--- a/services/rpz.c
+++ b/services/rpz.c
@@ -1807,7 +1807,7 @@ rpz_local_encode(struct module_env* env, struct query_info* qinfo,
                repinfo, temp, env->now_tv) ||
          !reply_info_answer_encode(qinfo, &rep,
                *(uint16_t*)sldns_buffer_begin(buf), sldns_buffer_read_u16_at(buf, 2),
-               buf, 0, 0, temp, udpsize, edns, (int)(edns->bits&EDNS_DO), 0)) {
+               buf, 0, 0, temp, udpsize, edns, (int)(edns->bits&EDNS_DO), 0, 0)) {
                error_encode(buf, (LDNS_RCODE_SERVFAIL|BIT_AA), qinfo,
                        *(uint16_t*)sldns_buffer_begin(buf),
                        sldns_buffer_read_u16_at(buf, 2), edns);

diff --git a/testcode/unitmain.c b/testcode/unitmain.c
index 653d3efbe9040745d54bc000b87943755e244156..763c9385f72e22c901f22a4169b82a8db4f3e203 100644 (file)
--- a/testcode/unitmain.c
+++ b/testcode/unitmain.c
@@ -1110,7 +1110,7 @@ static void edns_ede_encode_encodedecode(struct query_info* qinfo,
        /* encode */
        unit_assert(
                reply_info_answer_encode(qinfo, rep, 1, rep->flags, pkt,
-               0, 0, region, 65535, edns, 0, 0));
+               0, 0, region, 65535, edns, 0, 0, 0));
        /* buffer ready for reading; skip after the question section */
        sldns_buffer_skip(pkt, LDNS_HEADER_SIZE);
        (void)query_dname_len(pkt);

diff --git a/testdata/serve_expired_client_timeout_no_prefetch.rpl b/testdata/serve_expired_client_timeout_no_prefetch.rpl
index aed397d9e9ae35d42862480d351ac5b8e499dd09..0177dd14af6a5e0d03f82b4da484f28ef3f7e434 100644 (file)
--- a/testdata/serve_expired_client_timeout_no_prefetch.rpl
+++ b/testdata/serve_expired_client_timeout_no_prefetch.rpl
@@ -98,11 +98,11 @@ ENTRY_BEGIN
        SECTION QUESTION
                example.com. IN A
        SECTION ANSWER
-               example.com.  0 IN A 5.6.7.8
+               example.com.  1 IN A 5.6.7.8
        SECTION AUTHORITY
-               example.com. 3590 IN NS ns.example.com.
+               example.com. 3591 IN NS ns.example.com.
        SECTION ADDITIONAL
-               ns.example.com. 3590 IN A 1.2.3.4
+               ns.example.com. 3591 IN A 1.2.3.4
 ENTRY_END
 
 ; If a prefetch triggers the test will fail with 'messages pending'.

diff --git a/util/data/msgencode.c b/util/data/msgencode.c
index 6d116fb52d6d29204fd9cdb553faa05d666ec5a0..3129018db90f0cf46fd155563f2cf671c46f4ba5 100644 (file)
--- a/util/data/msgencode.c
+++ b/util/data/msgencode.c
@@ -997,7 +997,7 @@ int
 reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep, 
        uint16_t id, uint16_t qflags, sldns_buffer* pkt, time_t timenow,
        int cached, struct regional* region, uint16_t udpsize, 
-       struct edns_data* edns, int dnssec, int secure)
+       struct edns_data* edns, int dnssec, int secure, int cached_ttl)
 {
        uint16_t flags;
        unsigned int attach_edns = 0;
@@ -1022,6 +1022,17 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
                flags &= ~BIT_AD;
        }
        log_assert(flags & BIT_QR); /* QR bit must be on in our replies */
+       if(cached_ttl && rep->ttl - timenow == 0) {
+               /* The last remaining second of the TTL for a cached response
+                * is replied. This makes a 0 in the protocol message. The
+                * response is valid for the cache, but the DNS TTL 0 item
+                * causes the received to drop the contents. Even though the
+                * contents are cachable, so the time used is decremented
+                * to change that into 1 second, and it can be cached, and
+                * used for expired response generation, and does not give
+                * repeated queries during that last second. */
+               timenow --;
+       }
        if(udpsize < LDNS_HEADER_SIZE)
                return 0;
        /* currently edns does not change during calculations;

diff --git a/util/data/msgencode.h b/util/data/msgencode.h
index 6aff06099ee97f9b950c0f77ab472ce24f9327ac..bff6f7a40bbf75fd12f2b821c011c440b9b23009 100644 (file)
--- a/util/data/msgencode.h
+++ b/util/data/msgencode.h
@@ -64,12 +64,16 @@ struct edns_data;
  *     or if edns_present = 0, it is not included.
  * @param dnssec: if 0 DNSSEC records are omitted from the answer.
  * @param secure: if 1, the AD bit is set in the reply.
+ * @param cached_ttl: the ttl is from a cache response. So that means it
+ *     was some value minus the current time, and not an authoritative
+ *     response with an autoritative TTL or a direct upstream response,
+ *     that could have upstream TTL 0 items.
  * @return: 0 on error (server failure).
  */
 int reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep, 
        uint16_t id, uint16_t qflags, struct sldns_buffer* dest, time_t timenow,
        int cached, struct regional* region, uint16_t udpsize, 
-       struct edns_data* edns, int dnssec, int secure);
+       struct edns_data* edns, int dnssec, int secure, int cached_ttl);
 
 /**
  * Regenerate the wireformat from the stored msg reply.