summaryrefslogtreecommitdiffstats
path: root/lib/cache/entry_rr.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--lib/cache/entry_rr.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/lib/cache/entry_rr.c b/lib/cache/entry_rr.c
new file mode 100644
index 0000000..3239e7e
--- /dev/null
+++ b/lib/cache/entry_rr.c
@@ -0,0 +1,115 @@
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/** @file
+ * Implementation of RRset (de)materialization, i.e. (de)serialization to storage
+ * format used in cache (some repeated fields are omitted). Prototypes in ./impl.h
+ */
+
+#include "lib/cache/impl.h"
+
+void rdataset_dematerialize(const knot_rdataset_t *rds, uint8_t * restrict data)
+{
+ /* FIXME: either give up on even alignment and thus direct usability
+ * of rdatasets as they are in lmdb, or align inside cdb_* functions
+ * (request sizes one byte longer and shift iff on an odd address). */
+ //if ((size_t)data & 1) VERBOSE_MSG(NULL, "dematerialize: odd address\n");
+ //const uint8_t *data0 = data;
+ kr_require(data);
+ const uint16_t rr_count = rds ? rds->count : 0;
+ memcpy(data, &rr_count, sizeof(rr_count));
+ data += sizeof(rr_count);
+ if (rr_count) {
+ memcpy(data, rds->rdata, rds->size);
+ data += rds->size;
+ }
+ //VERBOSE_MSG(NULL, "dematerialized to %d B\n", (int)(data - data0));
+ (void)data; // silence analyzers
+}
+
+/** Materialize a knot_rdataset_t from cache with given TTL.
+ * Return the number of bytes consumed or an error code.
+ */
+static int rdataset_materialize(knot_rdataset_t * restrict rds, const uint8_t * const data,
+ const uint8_t *data_bound, knot_mm_t *pool)
+{
+ if (kr_fails_assert(rds && data && data_bound && data_bound > data && !rds->rdata
+ /*&& !((size_t)data & 1)*/))
+ return kr_error(EINVAL);
+ kr_assert(pool); /* not required, but that's our current usage; guard leaks */
+ const uint8_t *d = data; /* iterates over the cache data */
+ /* First sum up the sizes for wire format length. */
+ /* TODO: we might overrun here already, but we need to trust cache anyway...*/
+ rds->size = rdataset_dematerialized_size(d, &rds->count);
+ d += KR_CACHE_RR_COUNT_SIZE;
+ if (d + rds->size > data_bound) {
+ VERBOSE_MSG(NULL, "materialize: EILSEQ!\n");
+ return kr_error(EILSEQ);
+ }
+ if (!rds->count) { /* avoid mm_alloc(pool, 0); etc. */
+ rds->rdata = NULL;
+ return d - data;
+ }
+ rds->rdata = mm_alloc(pool, rds->size);
+ if (!rds->rdata) {
+ return kr_error(ENOMEM);
+ }
+ memcpy(rds->rdata, d, rds->size);
+ d += rds->size;
+ //VERBOSE_MSG(NULL, "materialized from %d B\n", (int)(d - data));
+ return d - data;
+}
+
+int kr_cache_materialize(knot_rdataset_t *dst, const struct kr_cache_p *ref,
+ knot_mm_t *pool)
+{
+ struct entry_h *eh = ref->raw_data;
+ return rdataset_materialize(dst, eh->data, ref->raw_bound, pool);
+}
+
+
+int entry2answer(struct answer *ans, int id,
+ const struct entry_h *eh, const uint8_t *eh_bound,
+ const knot_dname_t *owner, uint16_t type, uint32_t new_ttl)
+{
+ /* We assume it's zeroed. Do basic sanity check. */
+ const bool not_ok = ans->rrsets[id].set.rr || ans->rrsets[id].sig_rds.rdata
+ || (type == KNOT_RRTYPE_NSEC && ans->nsec_p.raw)
+ || (type == KNOT_RRTYPE_NSEC3 && !ans->nsec_p.raw);
+ if (kr_fails_assert(!not_ok))
+ return kr_error(EINVAL);
+ /* Materialize the base RRset. */
+ knot_rrset_t *rr = ans->rrsets[id].set.rr
+ = knot_rrset_new(owner, type, KNOT_CLASS_IN, new_ttl, ans->mm);
+ if (kr_fails_assert(rr))
+ return kr_error(ENOMEM);
+ int ret = rdataset_materialize(&rr->rrs, eh->data, eh_bound, ans->mm);
+ if (kr_fails_assert(ret >= 0)) goto fail;
+ size_t data_off = ret;
+ ans->rrsets[id].set.rank = eh->rank;
+ ans->rrsets[id].set.expiring = is_expiring(eh->ttl, new_ttl);
+ /* Materialize the RRSIG RRset for the answer in (pseudo-)packet. */
+ bool want_rrsigs = true; /* LATER(optim.): might be omitted in some cases. */
+ if (want_rrsigs) {
+ ret = rdataset_materialize(&ans->rrsets[id].sig_rds, eh->data + data_off,
+ eh_bound, ans->mm);
+ if (kr_fails_assert(ret >= 0)) goto fail;
+ /* Sanity check: we consumed exactly all data. */
+ int unused_bytes = eh_bound - (uint8_t *)eh->data - data_off - ret;
+ if (kr_fails_assert(unused_bytes == 0)) {
+ kr_log_error(CACHE, "entry2answer ERROR: unused bytes: %d\n",
+ unused_bytes);
+ ret = kr_error(EILSEQ);
+ goto fail; /* to be on the safe side */
+ }
+ }
+ return kr_ok();
+fail:
+ /* Cleanup the item that we might've (partially) written to. */
+ knot_rrset_free(ans->rrsets[id].set.rr, ans->mm);
+ knot_rdataset_clear(&ans->rrsets[id].sig_rds, ans->mm);
+ memset(&ans->rrsets[id], 0, sizeof(ans->rrsets[id]));
+ return kr_error(ret);
+}
+