diff options
Diffstat (limited to 'lib/cache/entry_rr.c')
| -rw-r--r-- | lib/cache/entry_rr.c | 115 |
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); +} + |