gc: handle the NS multi-entries much better

diff --git a/lib/cache/impl.h b/lib/cache/impl.h
index 2b18a4908f9b1fddaad1001dd6920b3584d92dd1..6afd389a46ee7baeda517e9b6aee699a5eb55906 100644 (file)
--- a/lib/cache/impl.h
+++ b/lib/cache/impl.h
@@ -237,7 +237,7 @@ int entry_h_splice(
        const struct kr_query *qry, struct kr_cache *cache, uint32_t timestamp);
 
 /** Parse an entry_apex into individual items.  @return error code. */
-int entry_list_parse(const knot_db_val_t val, entry_list_t list);
+KR_EXPORT int entry_list_parse(const knot_db_val_t val, entry_list_t list);
 
 static inline size_t to_even(size_t n)
 {

diff --git a/utils/cache_gc/db.c b/utils/cache_gc/db.c
index 57262df3da46e5932cfa10b6c36b760534a9ed8a..07fccf0a110daffd5445a9f2a6a0d2c755ac4ebb 100644 (file)
--- a/utils/cache_gc/db.c
+++ b/utils/cache_gc/db.c
@@ -144,6 +144,25 @@ void debug_printbin(const char *str, unsigned int len) {
 }
 #endif
 
+/** Return one entry_h reference from a cache DB value.  NULL if not consistent/suitable. */
+static const struct entry_h * val2entry(const knot_db_val_t val, uint16_t ktype)
+{
+       if (ktype != KNOT_RRTYPE_NS)
+               return entry_h_consistent(val, ktype);
+       /* Otherwise we have a multi-purpose entry.
+        * Well, for now we simply choose the most suitable entry;
+        * the only realistic collision is DNAME in apex where we'll prefer NS. */
+       entry_list_t el;
+       if (entry_list_parse(val, el))
+               return NULL;
+       for (int i = ENTRY_APEX_NSECS_CNT; i < EL_LENGTH; ++i) {
+               if (el[i].len)
+                       return entry_h_consistent(el[i], EL2RRTYPE(i));
+       }
+       /* Only NSEC* meta-data inside. */
+       return NULL;
+}
+
 int kr_gc_cache_iter(knot_db_t *knot_db, kr_gc_iter_callback callback, void *ctx)
 {
 #ifdef DEBUG
@@ -188,18 +207,23 @@ int kr_gc_cache_iter(knot_db_t *knot_db, kr_gc_iter_callback callback, void *ctx
                info.entry_size = key.len + val.len;
                info.valid = false;
                const uint16_t *entry_type = ret == KNOT_EOK ? kr_gc_key_consistent(key) : NULL;
-               struct entry_h *entry = NULL;
+               const struct entry_h *entry = NULL;
                if (entry_type != NULL) {
 #ifdef DEBUG
                        counter_gc_consistent++;
 #endif
-                       entry = entry_h_consistent(val, *entry_type);
-                       if (entry != NULL) {
-                               info.valid = true;
-                               info.rrtype = *entry_type;
-                               info.expires_in = entry->time + entry->ttl - now;
-                               info.no_labels = entry_labels(&key, *entry_type);
-                       }
+                       entry = val2entry(val, *entry_type);
+               }
+               /* TODO: perhaps improve some details around here:
+                *  - xNAME have .rrtype NS
+                *  - DNAME hidden on NS name will not be considered here
+                *  - if zone has NSEC* meta-data but no NS, it will be seen
+                *    here as kr_inconsistent */
+               if (entry != NULL) {
+                       info.valid = true;
+                       info.rrtype = *entry_type;
+                       info.expires_in = entry->time + entry->ttl - now;
+                       info.no_labels = entry_labels(&key, *entry_type);
                }
 #ifdef DEBUG
                counter_kr_consistent += info.valid;