lib/layer: answer both m12n/full names from cache

previously only queried names were resolved from cache, this meant that if the target name was present in cache but a server on the search path dropped from it, it would refetch it - this is a problem when a loadbalancer with very short TTL was in search path

diff --git a/lib/layer/iterate.c b/lib/layer/iterate.c
index 11cd46638ba2199f472f237d4ad86a1387e33b90..963cb47a79d2edc3bd6f8b234bc95d424303367b 100644 (file)
--- a/lib/layer/iterate.c
+++ b/lib/layer/iterate.c
@@ -50,7 +50,7 @@ static const knot_dname_t *minimized_qname(struct kr_query *query, uint16_t *qty
 {
        /* Minimization disabled. */
        const knot_dname_t *qname = query->sname;
-       if (query->flags & QUERY_NO_MINIMIZE) {
+       if (query->flags & (QUERY_NO_MINIMIZE|QUERY_CACHED)) {
                return qname;
        }
 

diff --git a/lib/layer/pktcache.c b/lib/layer/pktcache.c
index 050aec156255e35320b7e1c11b12af6f0289cdd5..35522c8ff2626a8f2e93af73443eff09e3814fbc 100644 (file)
--- a/lib/layer/pktcache.c
+++ b/lib/layer/pktcache.c
@@ -54,10 +54,9 @@ static void adjust_ttl(knot_rrset_t *rr, uint32_t drift)
        }
 }
 
-static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, uint8_t tag, uint32_t timestamp)
+static int loot_cache_set(namedb_txn_t *txn, knot_pkt_t *pkt, uint8_t tag, const knot_dname_t *qname,
+                          uint16_t rrtype, uint32_t timestamp)
 {
-       const knot_dname_t *qname = knot_pkt_qname(pkt);
-       uint16_t rrtype = knot_pkt_qtype(pkt);
        struct kr_cache_entry *entry;
        entry = kr_cache_peek(txn, tag, qname, rrtype, &timestamp);
        if (!entry) { /* Not in the cache */
@@ -91,6 +90,24 @@ static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, uint8_t tag, uint32_t
        return ret;
 }
 
+static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, struct kr_query *qry, uint8_t tag)
+{
+       uint32_t timestamp = qry->timestamp.tv_sec;
+       /* Try direct match first */
+       const knot_dname_t *qname = qry->sname;
+       uint16_t rrtype = qry->stype;
+       int ret = loot_cache_set(txn, pkt, tag, qname, rrtype, timestamp);
+       if (ret == kr_error(ENOENT)) {
+               /* Try minimized name second */
+               qname = knot_pkt_qname(pkt);
+               rrtype = knot_pkt_qtype(pkt);
+               if (!knot_dname_is_equal(qname, qry->sname)) {
+                       ret = loot_cache_set(txn, pkt, tag, qname, rrtype, timestamp);
+               }
+       }
+       return ret;
+}
+
 static int peek(knot_layer_t *ctx, knot_pkt_t *pkt)
 {
        struct kr_request *req = ctx->data;
@@ -109,8 +126,7 @@ static int peek(knot_layer_t *ctx, knot_pkt_t *pkt)
        if (kr_cache_txn_begin(cache, &txn, NAMEDB_RDONLY) != 0) {
                return ctx->state;
        }
-       uint32_t timestamp = qry->timestamp.tv_sec;
-       if (loot_cache(&txn, pkt, get_tag(req->answer), timestamp) != 0) {
+       if (loot_cache(&txn, pkt, qry, get_tag(req->answer)) != 0) {
                kr_cache_txn_abort(&txn);
                return ctx->state;
        }

diff --git a/lib/layer/rrcache.c b/lib/layer/rrcache.c
index 2b23742ae290efffd81af18a5dbf05e3b5fb40ee..8edc48d9fe0e04e3411e0a1160893281aeadbc62 100644 (file)
--- a/lib/layer/rrcache.c
+++ b/lib/layer/rrcache.c
@@ -53,11 +53,9 @@ static int loot_rr(namedb_txn_t *txn, knot_pkt_t *pkt, const knot_dname_t *name,
        return kr_ok();
 }
 
-static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, uint32_t timestamp)
+static int loot_cache_set(namedb_txn_t *txn, knot_pkt_t *pkt, const knot_dname_t *qname,
+                          uint16_t rrclass, uint16_t rrtype, uint32_t timestamp)
 {
-       const knot_dname_t *qname = knot_pkt_qname(pkt);
-       uint16_t rrclass = knot_pkt_qclass(pkt);
-       uint16_t rrtype = knot_pkt_qtype(pkt);
        int ret = loot_rr(txn, pkt, qname, rrtype, rrclass, timestamp);
        if (ret == kr_error(ENOENT) && rrtype != KNOT_RRTYPE_CNAME) { /* Chase CNAME if no direct hit */
                ret = loot_rr(txn, pkt, qname, KNOT_RRTYPE_CNAME, rrclass, timestamp);
@@ -65,6 +63,25 @@ static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, uint32_t timestamp)
        return ret;
 }
 
+static int loot_cache(namedb_txn_t *txn, knot_pkt_t *pkt, struct kr_query *qry)
+{
+       uint32_t timestamp = qry->timestamp.tv_sec;
+       /* Try direct match first */
+       const knot_dname_t *qname = qry->sname;
+       uint16_t rrclass = qry->sclass;
+       uint16_t rrtype = qry->stype;
+       int ret = loot_cache_set(txn, pkt, qname, rrclass, rrtype, timestamp);
+       if (ret == kr_error(ENOENT)) {
+               /* Try minimized name second */
+               qname = knot_pkt_qname(pkt);
+               rrtype = knot_pkt_qtype(pkt);
+               if (!knot_dname_is_equal(qname, qry->sname)) {
+                       ret = loot_cache_set(txn, pkt, qname, rrclass, rrtype, timestamp);
+               }
+       }
+       return ret;
+}
+
 static int peek(knot_layer_t *ctx, knot_pkt_t *pkt)
 {
        struct kr_request *req = ctx->data;
@@ -84,8 +101,7 @@ static int peek(knot_layer_t *ctx, knot_pkt_t *pkt)
         * it may either be a CNAME chain or direct answer.
         * Only one step of the chain is resolved at a time.
         */
-       uint32_t timestamp = qry->timestamp.tv_sec;
-       int ret = loot_cache(&txn, pkt, timestamp);
+       int ret = loot_cache(&txn, pkt, qry);
        kr_cache_txn_abort(&txn);
        if (ret == 0) {
                DEBUG_MSG("=> satisfied from cache\n");