diff options
Diffstat (limited to 'lib/cache/api.c')
| -rw-r--r-- | lib/cache/api.c | 1029 |
1 files changed, 1029 insertions, 0 deletions
diff --git a/lib/cache/api.c b/lib/cache/api.c new file mode 100644 index 0000000..116d775 --- /dev/null +++ b/lib/cache/api.c @@ -0,0 +1,1029 @@ +/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz> + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#include <errno.h> +#include <limits.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <time.h> +#include <unistd.h> + +#include <libknot/descriptor.h> +#include <libknot/dname.h> +#include <libknot/errcode.h> +#include <libknot/rrtype/rrsig.h> + +#include <uv.h> + +#include "contrib/base32hex.h" +#include "contrib/cleanup.h" +#include "contrib/ucw/lib.h" +#include "lib/cache/api.h" +#include "lib/cache/cdb_lmdb.h" +#include "lib/defines.h" +#include "lib/dnssec/nsec3.h" +#include "lib/generic/trie.h" +#include "lib/resolve.h" +#include "lib/rplan.h" +#include "lib/utils.h" + +#include "lib/cache/impl.h" + +/* TODO: + * - Reconsider when RRSIGs are put in and retrieved from the cache. + * Currently it's always done, which _might_ be spurious, depending + * on how kresd will use the returned result. + * There's also the "problem" that kresd ATM does _not_ ask upstream + * with DO bit in some cases. + */ + + +/** Cache version */ +static const uint16_t CACHE_VERSION = 6; +/** Key size */ +#define KEY_HSIZE (sizeof(uint8_t) + sizeof(uint16_t)) +#define KEY_SIZE (KEY_HSIZE + KNOT_DNAME_MAXLEN) + + +/** @internal Forward declarations of the implementation details + * \param needs_pkt[out] optionally set *needs_pkt = true; + * We do that when some RRset wasn't stashed to aggressive cache, + * even though it might have taken part in a successful DNSSEC proof: + * 1. any opt-out NSEC3, as they typically aren't much use aggressively anyway + * 2. some kinds of minimal NSEC* ranges, as they'd seem more trouble than worth: + * - extremely short range of covered names limits the benefits severely + * - the type-set is often a lie, either a working lie, e.g. CloudFlare's + * black lies, or even a non-working lie, e.g. DVE-2018-0003 + * 3. some kinds of "weird" RRsets, to get at least some caching on them + */ +static ssize_t stash_rrset(struct kr_cache *cache, const struct kr_query *qry, + const knot_rrset_t *rr, const knot_rrset_t *rr_sigs, uint32_t timestamp, + uint8_t rank, trie_t *nsec_pmap, knot_mm_t *pool, bool *needs_pkt); +/** Preliminary checks before stash_rrset(). Don't call if returns <= 0. */ +static int stash_rrset_precond(const knot_rrset_t *rr, const struct kr_query *qry/*logs*/); + +/** @internal Ensure the cache version is right, possibly by clearing it. */ +static int assert_right_version(struct kr_cache *cache) +{ + /* Check cache ABI version. */ + /* CACHE_KEY_DEF: to avoid collisions with kr_cache_match(). */ + uint8_t key_str[4] = "VERS"; + knot_db_val_t key = { .data = key_str, .len = sizeof(key_str) }; + knot_db_val_t val = { NULL, 0 }; + int ret = cache_op(cache, read, &key, &val, 1); + if (ret == 0 && val.len == sizeof(CACHE_VERSION) + && memcmp(val.data, &CACHE_VERSION, sizeof(CACHE_VERSION)) == 0) { + ret = kr_ok(); + } else { + int oldret = ret; + /* Version doesn't match or we were unable to read it, possibly because DB is empty. + * Recreate cache and write version key. */ + ret = cache_op(cache, count); + if (ret != 0) { /* Log for non-empty cache to limit noise on fresh start. */ + kr_log_info(CACHE, "incompatible cache database detected, purging\n"); + if (oldret) { + kr_log_debug(CACHE, "reading version returned: %d\n", oldret); + } else if (val.len != sizeof(CACHE_VERSION)) { + kr_log_debug(CACHE, "version has bad length: %d\n", (int)val.len); + } else { + uint16_t ver; + memcpy(&ver, val.data, sizeof(ver)); + kr_log_debug(CACHE, "version has bad value: %d instead of %d\n", + (int)ver, (int)CACHE_VERSION); + } + } + ret = cache_op(cache, clear); + } + /* Rewrite the entry even if it isn't needed. Because of cache-size-changing + * possibility it's good to always perform some write during opening of cache. */ + if (ret == 0) { + /* Key/Val is invalidated by cache purge, recreate it */ + val.data = /*const-cast*/(void *)&CACHE_VERSION; + val.len = sizeof(CACHE_VERSION); + ret = cache_op(cache, write, &key, &val, 1); + } + kr_cache_commit(cache); + return ret; +} + +int kr_cache_open(struct kr_cache *cache, const struct kr_cdb_api *api, struct kr_cdb_opts *opts, knot_mm_t *mm) +{ + if (kr_fails_assert(cache)) + return kr_error(EINVAL); + memset(cache, 0, sizeof(*cache)); + /* Open cache */ + if (!api) + api = kr_cdb_lmdb(); + cache->api = api; + int ret = cache->api->open(&cache->db, &cache->stats, opts, mm); + if (ret == 0) { + ret = assert_right_version(cache); + // The included write also committed maxsize increase to the file. + } + if (ret == 0 && opts->maxsize) { + /* If some maxsize is requested and it's smaller than in-file maxsize, + * LMDB only restricts our env without changing the in-file maxsize. + * That is worked around by reopening (found no other reliable way). */ + cache->api->close(cache->db, &cache->stats); + struct kr_cdb_opts opts2; + memcpy(&opts2, opts, sizeof(opts2)); + opts2.maxsize = 0; + ret = cache->api->open(&cache->db, &cache->stats, &opts2, mm); + } + + char *fpath = kr_absolutize_path(opts->path, "data.mdb"); + if (kr_fails_assert(fpath)) { + /* non-critical, but still */ + fpath = "<ENOMEM>"; + } else { + kr_cache_emergency_file_to_remove = fpath; + } + + if (ret == 0 && opts->maxsize) { + size_t maxsize = cache->api->get_maxsize(cache->db); + if (maxsize > opts->maxsize) kr_log_warning(CACHE, + "Warning: real cache size is %zu instead of the requested %zu bytes." + " To reduce the size you need to remove the file '%s' by hand.\n", + maxsize, opts->maxsize, fpath); + } + if (ret != 0) + return ret; + cache->ttl_min = KR_CACHE_DEFAULT_TTL_MIN; + cache->ttl_max = KR_CACHE_DEFAULT_TTL_MAX; + kr_cache_make_checkpoint(cache); + return 0; +} + +const char *kr_cache_emergency_file_to_remove = NULL; + + +#define cache_isvalid(cache) ((cache) && (cache)->api && (cache)->db) + +void kr_cache_close(struct kr_cache *cache) +{ + kr_cache_check_health(cache, -1); + if (cache_isvalid(cache)) { + cache_op(cache, close); + cache->db = NULL; + } + free(/*const-cast*/(char*)kr_cache_emergency_file_to_remove); + kr_cache_emergency_file_to_remove = NULL; +} + +int kr_cache_commit(struct kr_cache *cache) +{ + if (!cache_isvalid(cache)) { + return kr_error(EINVAL); + } + if (cache->api->commit) { + return cache_op(cache, commit); + } + return kr_ok(); +} + +int kr_cache_clear(struct kr_cache *cache) +{ + if (!cache_isvalid(cache)) { + return kr_error(EINVAL); + } + int ret = cache_op(cache, clear); + if (ret == 0) { + kr_cache_make_checkpoint(cache); + ret = assert_right_version(cache); + } + return ret; +} + +/* When going stricter, BEWARE of breaking entry_h_consistent_NSEC() */ +struct entry_h * entry_h_consistent_E(knot_db_val_t data, uint16_t type) +{ + (void) type; /* unused, for now */ + if (!data.data) return NULL; + /* Length checks. */ + if (data.len < offsetof(struct entry_h, data)) + return NULL; + const struct entry_h *eh = data.data; + if (eh->is_packet) { + uint16_t pkt_len; + if (data.len < offsetof(struct entry_h, data) + sizeof(pkt_len)) { + return NULL; + } + memcpy(&pkt_len, eh->data, sizeof(pkt_len)); + if (data.len < offsetof(struct entry_h, data) + sizeof(pkt_len) + + pkt_len) { + return NULL; + } + } + + bool ok = true; + ok = ok && kr_rank_check(eh->rank); + ok = ok && (!kr_rank_test(eh->rank, KR_RANK_BOGUS) + || eh->is_packet); + ok = ok && (eh->is_packet || !eh->has_optout); + + return ok ? /*const-cast*/(struct entry_h *)eh : NULL; +} + +int32_t get_new_ttl(const struct entry_h *entry, const struct kr_query *qry, + const knot_dname_t *owner, uint16_t type, uint32_t now) +{ + int32_t diff = now - entry->time; + if (diff < 0) { + /* We may have obtained the record *after* the request started. */ + diff = 0; + } + int32_t res = entry->ttl - diff; + if (res < 0 && owner && qry && qry->stale_cb) { + /* Stale-serving decision, delegated to a callback. */ + int res_stale = qry->stale_cb(res, owner, type, qry); + if (res_stale >= 0) { + VERBOSE_MSG(qry, "responding with stale answer\n"); + /* LATER: Perhaps we could use a more specific Stale + * NXDOMAIN Answer code for applicable responses. */ + kr_request_set_extended_error(qry->request, KNOT_EDNS_EDE_STALE, "6Q6X"); + return res_stale; + } + } + return res; +} + +int32_t kr_cache_ttl(const struct kr_cache_p *peek, const struct kr_query *qry, + const knot_dname_t *name, uint16_t type) +{ + const struct entry_h *eh = peek->raw_data; + return get_new_ttl(eh, qry, name, type, qry->timestamp.tv_sec); +} + +/** Check that no label contains a zero character, incl. a log trace. + * + * We refuse to work with those, as LF and our cache keys might become ambiguous. + * Assuming uncompressed name, as usual. + * CACHE_KEY_DEF + */ +static bool check_dname_for_lf(const knot_dname_t *n, const struct kr_query *qry/*logging*/) +{ + const bool ret = knot_dname_size(n) == strlen((const char *)n) + 1; + if (!ret && kr_log_is_debug_qry(CACHE, qry)) { + auto_free char *n_str = kr_dname_text(n); + VERBOSE_MSG(qry, "=> skipping zero-containing name %s\n", n_str); + } + return ret; +} + +/** Return false on types to be ignored. Meant both for sname and direct cache requests. */ +static bool check_rrtype(uint16_t type, const struct kr_query *qry/*logging*/) +{ + const bool ret = !knot_rrtype_is_metatype(type) + && type != KNOT_RRTYPE_RRSIG; + if (!ret && kr_log_is_debug_qry(CACHE, qry)) { + auto_free char *type_str = kr_rrtype_text(type); + VERBOSE_MSG(qry, "=> skipping RR type %s\n", type_str); + } + return ret; +} + +/** Like key_exact_type() but omits a couple checks not holding for pkt cache. */ +knot_db_val_t key_exact_type_maypkt(struct key *k, uint16_t type) +{ + if (kr_fails_assert(check_rrtype(type, NULL))) + return (knot_db_val_t){ NULL, 0 }; + switch (type) { + case KNOT_RRTYPE_RRSIG: /* no RRSIG query caching, at least for now */ + kr_assert(false); + return (knot_db_val_t){ NULL, 0 }; + /* xNAME lumped into NS. */ + case KNOT_RRTYPE_CNAME: + case KNOT_RRTYPE_DNAME: + type = KNOT_RRTYPE_NS; + default: + break; + } + + int name_len = k->buf[0]; + k->buf[name_len + 1] = 0; /* make sure different names can never match */ + k->buf[name_len + 2] = 'E'; /* tag for exact name+type matches */ + memcpy(k->buf + name_len + 3, &type, 2); + k->type = type; + /* CACHE_KEY_DEF: key == dname_lf + '\0' + 'E' + RRTYPE */ + return (knot_db_val_t){ k->buf + 1, name_len + 4 }; +} + + +/** The inside for cache_peek(); implementation separated to ./peek.c */ +int peek_nosync(kr_layer_t *ctx, knot_pkt_t *pkt); +/** function for .produce phase */ +int cache_peek(kr_layer_t *ctx, knot_pkt_t *pkt) +{ + struct kr_request *req = ctx->req; + struct kr_query *qry = req->current_query; + /* We first check various exit-conditions and then call the _real function. */ + + if (!kr_cache_is_open(&req->ctx->cache) + || ctx->state & (KR_STATE_FAIL|KR_STATE_DONE) || qry->flags.NO_CACHE + || (qry->flags.CACHE_TRIED && !qry->stale_cb) + || !check_rrtype(qry->stype, qry) /* LATER: some other behavior for some of these? */ + || qry->sclass != KNOT_CLASS_IN) { + return ctx->state; /* Already resolved/failed or already tried, etc. */ + } + /* ATM cache only peeks for qry->sname and that would be useless + * to repeat on every iteration, so disable it from now on. + * LATER(optim.): assist with more precise QNAME minimization. */ + qry->flags.CACHE_TRIED = true; + + if (qry->stype == KNOT_RRTYPE_NSEC) { + VERBOSE_MSG(qry, "=> skipping stype NSEC\n"); + return ctx->state; + } + if (!check_dname_for_lf(qry->sname, qry)) { + return ctx->state; + } + + int ret = peek_nosync(ctx, pkt); + kr_cache_commit(&req->ctx->cache); + return ret; +} + + + +/** It's simply inside of cycle taken out to decrease indentation. \return error code. */ +static int stash_rrarray_entry(ranked_rr_array_t *arr, int arr_i, + const struct kr_query *qry, struct kr_cache *cache, + int *unauth_cnt, trie_t *nsec_pmap, bool *needs_pkt); +/** Stash a single nsec_p. \return 0 (errors are ignored). */ +static int stash_nsec_p(const knot_dname_t *dname, const char *nsec_p_v, + struct kr_cache *cache, uint32_t timestamp, knot_mm_t *pool, + const struct kr_query *qry/*logging*/); + +/** The whole .consume phase for the cache module. */ +int cache_stash(kr_layer_t *ctx, knot_pkt_t *pkt) +{ + struct kr_request *req = ctx->req; + struct kr_query *qry = req->current_query; + struct kr_cache *cache = &req->ctx->cache; + + /* Note: we cache even in KR_STATE_FAIL. For example, + * BOGUS answer can go to +cd cache even without +cd request. */ + if (!kr_cache_is_open(cache) || !qry + || qry->flags.CACHED || !check_rrtype(knot_pkt_qtype(pkt), qry) + || qry->sclass != KNOT_CLASS_IN) { + return ctx->state; + } + /* Do not cache truncated answers, at least for now. LATER */ + if (knot_wire_get_tc(pkt->wire)) { + return ctx->state; + } + int unauth_cnt = 0; + bool needs_pkt = false; + if (qry->flags.STUB) { + needs_pkt = true; + goto stash_packet; + } + + /* Stash individual records. */ + ranked_rr_array_t *selected[] = kr_request_selected(req); + trie_t *nsec_pmap = trie_create(&req->pool); + if (kr_fails_assert(nsec_pmap)) + goto finally; + for (int psec = KNOT_ANSWER; psec <= KNOT_ADDITIONAL; ++psec) { + ranked_rr_array_t *arr = selected[psec]; + /* uncached entries are located at the end */ + for (ssize_t i = arr->len - 1; i >= 0; --i) { + ranked_rr_array_entry_t *entry = arr->at[i]; + if (entry->qry_uid != qry->uid || entry->dont_cache) { + continue; + /* TODO: probably safe to break on uid mismatch but maybe not worth it */ + } + int ret = stash_rrarray_entry( + arr, i, qry, cache, &unauth_cnt, nsec_pmap, + /* ADDITIONAL RRs are considered non-essential + * in our (resolver) answers */ + (psec == KNOT_ADDITIONAL ? NULL : &needs_pkt)); + if (ret) { + VERBOSE_MSG(qry, "=> stashing RRs errored out\n"); + goto finally; + } + /* LATER(optim.): maybe filter out some type-rank combinations + * that won't be useful as separate RRsets. */ + } + } + + trie_it_t *it; + for (it = trie_it_begin(nsec_pmap); !trie_it_finished(it); trie_it_next(it)) { + stash_nsec_p((const knot_dname_t *)trie_it_key(it, NULL), + (const char *)*trie_it_val(it), + cache, qry->timestamp.tv_sec, &req->pool, req->current_query); + } + trie_it_free(it); + /* LATER(optim.): typically we also have corresponding NS record in the list, + * so we might save a cache operation. */ +stash_packet: + if (qry->flags.PKT_IS_SANE && check_dname_for_lf(knot_pkt_qname(pkt), qry)) { + stash_pkt(pkt, qry, req, needs_pkt); + } + +finally: + if (unauth_cnt) { + VERBOSE_MSG(qry, "=> stashed also %d nonauth RRsets\n", unauth_cnt); + }; + kr_cache_commit(cache); + return ctx->state; /* we ignore cache-stashing errors */ +} + +/** Preliminary checks before stash_rrset(). Don't call if returns <= 0. */ +static int stash_rrset_precond(const knot_rrset_t *rr, const struct kr_query *qry/*logs*/) +{ + if (kr_fails_assert(rr && rr->rclass == KNOT_CLASS_IN)) + return kr_error(EINVAL); + if (!check_rrtype(rr->type, qry)) + return kr_ok(); + if (!check_dname_for_lf(rr->owner, qry)) + return kr_ok(); + return 1/*proceed*/; +} + +/** Return true on some cases of NSEC* RRsets covering minimal ranges. + * Also include some abnormal RR cases; qry is just for logging. */ +static bool rrset_has_min_range_or_weird(const knot_rrset_t *rr, const struct kr_query *qry) +{ + if (rr->rrs.count != 1) { + kr_assert(rr->rrs.count > 0); + if (rr->type == KNOT_RRTYPE_NSEC || rr->type == KNOT_RRTYPE_NSEC3 + || rr->rrs.count == 0) { + return true; /*< weird */ + } + } + bool ret; /**< NOT used for the weird cases */ + if (rr->type == KNOT_RRTYPE_NSEC) { + if (!check_dname_for_lf(rr->owner, qry)) + return true; /*< weird, probably filtered even before this point */ + ret = !check_dname_for_lf(knot_nsec_next(rr->rrs.rdata), qry); + /* ^^ Zero inside the next-name label means it's probably a minimal range, + * and anyway it's problematic for our aggressive cache (comparisons). + * Real-life examples covered: + * NSEC: name -> \000.name (e.g. typical foobar.CloudFlare.net) + * NSEC: name -> name\000 (CloudFlare on delegations) + */ + } else if (rr->type == KNOT_RRTYPE_NSEC3) { + if (knot_nsec3_next_len(rr->rrs.rdata) != NSEC3_HASH_LEN + || *rr->owner != NSEC3_HASH_TXT_LEN) { + return true; /*< weird */ + } + /* Let's work on the binary hashes. Find if they "differ by one", + * by constructing the owner hash incremented by one and comparing. */ + uint8_t owner_hash[NSEC3_HASH_LEN]; + if (base32hex_decode(rr->owner + 1, NSEC3_HASH_TXT_LEN, + owner_hash, NSEC3_HASH_LEN) != NSEC3_HASH_LEN) { + return true; /*< weird */ + } + for (int i = NSEC3_HASH_LEN - 1; i >= 0; --i) { + if (++owner_hash[i] != 0) break; + } + const uint8_t *next_hash = knot_nsec3_next(rr->rrs.rdata); + ret = memcmp(owner_hash, next_hash, NSEC3_HASH_LEN) == 0; + } else { + return false; + } + if (ret) VERBOSE_MSG(qry, "=> minimized NSEC* range detected\n"); + return ret; +} + +static ssize_t stash_rrset(struct kr_cache *cache, const struct kr_query *qry, + const knot_rrset_t *rr, const knot_rrset_t *rr_sigs, uint32_t timestamp, + uint8_t rank, trie_t *nsec_pmap, knot_mm_t *pool, bool *needs_pkt) +{ + if (kr_rank_test(rank, KR_RANK_BOGUS)) { + WITH_VERBOSE(qry) { + auto_free char *type_str = kr_rrtype_text(rr->type); + VERBOSE_MSG(qry, "=> skipping bogus RR set %s\n", type_str); + } + return kr_ok(); + } + if (rr->type == KNOT_RRTYPE_NSEC3 && rr->rrs.count + && knot_nsec3_iters(rr->rrs.rdata) > KR_NSEC3_MAX_ITERATIONS) { + /* This shouldn't happen often, thanks to downgrades during validation. */ + VERBOSE_MSG(qry, "=> skipping NSEC3 with too many iterations\n"); + return kr_ok(); + } + if (kr_fails_assert(cache && stash_rrset_precond(rr, qry) > 0)) + return kr_error(EINVAL); + + int ret = kr_ok(); + if (rrset_has_min_range_or_weird(rr, qry)) + goto return_needs_pkt; + const int wild_labels = rr_sigs == NULL ? 0 : + knot_dname_labels(rr->owner, NULL) - knot_rrsig_labels(rr_sigs->rrs.rdata); + if (wild_labels < 0) + goto return_needs_pkt; + const knot_dname_t *encloser = rr->owner; /**< the closest encloser name */ + for (int i = 0; i < wild_labels; ++i) { + encloser = knot_wire_next_label(encloser, NULL); + } + + /* Construct the key under which RRs will be stored, + * and add corresponding nsec_pmap item (if necessary). */ + struct key k_storage, *k = &k_storage; + knot_db_val_t key; + switch (rr->type) { + case KNOT_RRTYPE_NSEC3: + /* Skip opt-out NSEC3 sets. */ + if (KNOT_NSEC3_FLAG_OPT_OUT & knot_nsec3_flags(rr->rrs.rdata)) + goto return_needs_pkt; + /* fall through */ + case KNOT_RRTYPE_NSEC: + /* Skip any NSEC*s that aren't validated or are suspicious. */ + if (!kr_rank_test(rank, KR_RANK_SECURE) || rr->rrs.count != 1) + goto return_needs_pkt; + if (kr_fails_assert(rr_sigs && rr_sigs->rrs.count && rr_sigs->rrs.rdata)) { + ret = kr_error(EINVAL); + goto return_needs_pkt; + } + const knot_dname_t *signer = knot_rrsig_signer_name(rr_sigs->rrs.rdata); + const int signer_size = knot_dname_size(signer); + k->zlf_len = signer_size - 1; + + void **npp = NULL; + if (nsec_pmap) { + npp = trie_get_ins(nsec_pmap, (const char *)signer, signer_size); + if (kr_fails_assert(npp)) + return kr_error(ENOMEM); + } + if (rr->type == KNOT_RRTYPE_NSEC) { + key = key_NSEC1(k, encloser, wild_labels); + break; + } + + kr_require(rr->type == KNOT_RRTYPE_NSEC3); + const knot_rdata_t * const rdata = rr->rrs.rdata; + if (rdata->len <= 4) { + ret = kr_error(EILSEQ); /*< data from outside; less trust */ + goto return_needs_pkt; + } + const int np_dlen = nsec_p_rdlen(rdata->data); + if (np_dlen > rdata->len) { + ret = kr_error(EILSEQ); + goto return_needs_pkt; + } + key = key_NSEC3(k, encloser, nsec_p_mkHash(rdata->data)); + if (npp && !*npp) { + *npp = mm_alloc(pool, np_dlen); + if (kr_fails_assert(*npp)) + break; + memcpy(*npp, rdata->data, np_dlen); + } + break; + default: + ret = kr_dname_lf(k->buf, encloser, wild_labels); + if (kr_fails_assert(ret == 0)) + goto return_needs_pkt; + key = key_exact_type(k, rr->type); + } + + /* Compute in-cache size for the new data. */ + const knot_rdataset_t *rds_sigs = rr_sigs ? &rr_sigs->rrs : NULL; + const int rr_ssize = rdataset_dematerialize_size(&rr->rrs); + if (kr_fails_assert(rr_ssize == to_even(rr_ssize))) + return kr_error(EINVAL); + knot_db_val_t val_new_entry = { + .data = NULL, + .len = offsetof(struct entry_h, data) + rr_ssize + + rdataset_dematerialize_size(rds_sigs), + }; + + /* Prepare raw memory for the new entry. */ + ret = entry_h_splice(&val_new_entry, rank, key, k->type, rr->type, + rr->owner, qry, cache, timestamp); + if (ret) return kr_ok(); /* some aren't really errors */ + if (kr_fails_assert(val_new_entry.data)) + return kr_error(EFAULT); + + /* Write the entry itself. */ + struct entry_h *eh = val_new_entry.data; + memset(eh, 0, offsetof(struct entry_h, data)); + eh->time = timestamp; + eh->ttl = rr->ttl; + eh->rank = rank; + rdataset_dematerialize(&rr->rrs, eh->data); + rdataset_dematerialize(rds_sigs, eh->data + rr_ssize); + if (kr_fails_assert(entry_h_consistent_E(val_new_entry, rr->type))) + return kr_error(EINVAL); + + #if 0 /* Occasionally useful when debugging some kinds of changes. */ + { + kr_cache_commit(cache); + knot_db_val_t val = { NULL, 0 }; + ret = cache_op(cache, read, &key, &val, 1); + if (ret != kr_error(ENOENT)) { // ENOENT might happen in some edge case, I guess + kr_assert(!ret); + entry_list_t el; + entry_list_parse(val, el); + } + } + #endif + + /* Verbose-log some not-too-common cases. */ + WITH_VERBOSE(qry) { if (kr_rank_test(rank, KR_RANK_AUTH) + || rr->type == KNOT_RRTYPE_NS) { + auto_free char *type_str = kr_rrtype_text(rr->type), + *encl_str = kr_dname_text(encloser); + VERBOSE_MSG(qry, "=> stashed %s%s %s, rank 0%.2o, " + "%d B total, incl. %d RRSIGs\n", + (wild_labels ? "*." : ""), encl_str, type_str, rank, + (int)val_new_entry.len, (rr_sigs ? rr_sigs->rrs.count : 0) + ); + } } + + return (ssize_t) val_new_entry.len; +return_needs_pkt: + if (needs_pkt) *needs_pkt = true; + return ret; +} + +static int stash_rrarray_entry(ranked_rr_array_t *arr, int arr_i, + const struct kr_query *qry, struct kr_cache *cache, + int *unauth_cnt, trie_t *nsec_pmap, bool *needs_pkt) +{ + ranked_rr_array_entry_t *entry = arr->at[arr_i]; + if (entry->cached) { + return kr_ok(); + } + const knot_rrset_t *rr = entry->rr; + if (rr->type == KNOT_RRTYPE_RRSIG) { + return kr_ok(); /* reduce verbose logging from the following call */ + } + int ret = stash_rrset_precond(rr, qry); + if (ret <= 0) { + return ret; + } + + /* Try to find corresponding signatures, always. LATER(optim.): speed. */ + ranked_rr_array_entry_t *entry_rrsigs = NULL; + const knot_rrset_t *rr_sigs = NULL; + for (ssize_t j = arr->len - 1; j >= 0; --j) { + /* TODO: ATM we assume that some properties are the same + * for all RRSIGs in the set (esp. label count). */ + ranked_rr_array_entry_t *e = arr->at[j]; + if (kr_fails_assert(!e->in_progress)) + return kr_error(EINVAL); + bool ok = e->qry_uid == qry->uid && !e->cached + && e->rr->type == KNOT_RRTYPE_RRSIG + && knot_rrsig_type_covered(e->rr->rrs.rdata) == rr->type + && knot_dname_is_equal(rr->owner, e->rr->owner); + if (!ok) continue; + entry_rrsigs = e; + rr_sigs = e->rr; + break; + } + + ssize_t written = stash_rrset(cache, qry, rr, rr_sigs, qry->timestamp.tv_sec, + entry->rank, nsec_pmap, &qry->request->pool, needs_pkt); + if (written < 0) { + kr_log_error(CACHE, "[%05u.%02u] stash failed, ret = %d\n", qry->request->uid, + qry->uid, ret); + return (int) written; + } + + if (written > 0) { + /* Mark entry as cached for the rest of the query processing */ + entry->cached = true; + if (entry_rrsigs) { + entry_rrsigs->cached = true; + } + if (!kr_rank_test(entry->rank, KR_RANK_AUTH) && rr->type != KNOT_RRTYPE_NS) { + *unauth_cnt += 1; + } + } + + return kr_ok(); +} + +static int stash_nsec_p(const knot_dname_t *dname, const char *nsec_p_v, + struct kr_cache *cache, uint32_t timestamp, knot_mm_t *pool, + const struct kr_query *qry/*logging*/) +{ + uint32_t valid_until = timestamp + cache->ttl_max; + /* LATER(optim.): be more precise here ^^ and reduce calls. */ + static const int32_t ttl_margin = 3600; + const uint8_t *nsec_p = (const uint8_t *)nsec_p_v; + int data_stride = sizeof(valid_until) + nsec_p_rdlen(nsec_p); + + unsigned int log_hash = 0xFeeeFeee; /* this type is simpler for printf args */ + auto_free char *log_dname = NULL; + WITH_VERBOSE(qry) { + log_hash = nsec_p_v ? nsec_p_mkHash((const uint8_t *)nsec_p_v) : 0; + log_dname = kr_dname_text(dname); + } + /* Find what's in the cache. */ + struct key k_storage, *k = &k_storage; + int ret = kr_dname_lf(k->buf, dname, false); + if (ret) return kr_error(ret); + knot_db_val_t key = key_exact_type(k, KNOT_RRTYPE_NS); + knot_db_val_t val_orig = { NULL, 0 }; + ret = cache_op(cache, read, &key, &val_orig, 1); + if (ret && ret != -ABS(ENOENT)) { + VERBOSE_MSG(qry, "=> EL read failed (ret: %d)\n", ret); + return kr_ok(); + } + /* Prepare new entry_list_t so we can just write at el[0]. */ + entry_list_t el; + int log_refresh_by = 0; + if (ret == -ABS(ENOENT)) { + memset(el, 0, sizeof(el)); + } else { + ret = entry_list_parse(val_orig, el); + if (ret) { + VERBOSE_MSG(qry, "=> EL parse failed (ret: %d)\n", ret); + return kr_error(0); + } + /* Find the index to replace. */ + int i_replace = ENTRY_APEX_NSECS_CNT - 1; + for (int i = 0; i < ENTRY_APEX_NSECS_CNT; ++i) { + if (el[i].len != data_stride) continue; + if (nsec_p && memcmp(nsec_p, (uint8_t *)el[i].data + sizeof(uint32_t), + data_stride - sizeof(uint32_t)) != 0) { + continue; + } + /* Save a cache operation if TTL extended only a little. */ + uint32_t valid_orig; + memcpy(&valid_orig, el[i].data, sizeof(valid_orig)); + const int32_t ttl_extended_by = valid_until - valid_orig; + if (ttl_extended_by < ttl_margin) { + VERBOSE_MSG(qry, + "=> nsec_p stash for %s skipped (extra TTL: %d, hash: %x)\n", + log_dname, ttl_extended_by, log_hash); + return kr_ok(); + } + i_replace = i; + log_refresh_by = ttl_extended_by; + break; + } + /* Shift the other indices: move the first `i_replace` blocks + * by one position. */ + if (i_replace) { + memmove(&el[1], &el[0], sizeof(el[0]) * i_replace); + } + } + /* Prepare old data into a buffer. See entry_h_splice() for why. LATER(optim.) */ + el[0].len = data_stride; + el[0].data = NULL; + knot_db_val_t val; + val.len = entry_list_serial_size(el), + val.data = mm_alloc(pool, val.len), + entry_list_memcpy(val.data, el); + /* Prepare the new data chunk */ + memcpy(el[0].data, &valid_until, sizeof(valid_until)); + if (nsec_p) { + memcpy((uint8_t *)el[0].data + sizeof(valid_until), nsec_p, + data_stride - sizeof(valid_until)); + } + /* Write it all to the cache */ + ret = cache_op(cache, write, &key, &val, 1); + mm_free(pool, val.data); + if (ret || !val.data) { + VERBOSE_MSG(qry, "=> EL write failed (ret: %d)\n", ret); + return kr_ok(); + } + if (log_refresh_by) { + VERBOSE_MSG(qry, "=> nsec_p stashed for %s (refresh by %d, hash: %x)\n", + log_dname, log_refresh_by, log_hash); + } else { + VERBOSE_MSG(qry, "=> nsec_p stashed for %s (new, hash: %x)\n", + log_dname, log_hash); + } + return kr_ok(); +} + +int kr_cache_insert_rr(struct kr_cache *cache, + const knot_rrset_t *rr, const knot_rrset_t *rrsig, + uint8_t rank, uint32_t timestamp, bool ins_nsec_p) +{ + int err = stash_rrset_precond(rr, NULL); + if (err <= 0) { + return kr_ok(); + } + + trie_t *nsec_pmap = NULL; + knot_mm_t *pool = NULL; + if (ins_nsec_p && (rr->type == KNOT_RRTYPE_NSEC || rr->type == KNOT_RRTYPE_NSEC3)) { + pool = mm_ctx_mempool2(4096); + nsec_pmap = trie_create(pool); + kr_assert(pool && nsec_pmap); + } + + ssize_t written = stash_rrset(cache, NULL, rr, rrsig, timestamp, rank, + nsec_pmap, pool, NULL); + + if (nsec_pmap) { + trie_it_t *it; + for (it = trie_it_begin(nsec_pmap); !trie_it_finished(it); trie_it_next(it)) { + stash_nsec_p((const knot_dname_t *)trie_it_key(it, NULL), + (const char *)*trie_it_val(it), + cache, timestamp, pool, NULL); + } + trie_it_free(it); + mm_ctx_delete(pool); + } + + if (written >= 0) { + return kr_ok(); + } + + return (int) written; +} + +static int peek_exact_real(struct kr_cache *cache, const knot_dname_t *name, uint16_t type, + struct kr_cache_p *peek) +{ + if (!check_rrtype(type, NULL) || !check_dname_for_lf(name, NULL)) { + return kr_error(ENOTSUP); + } + struct key k_storage, *k = &k_storage; + + int ret = kr_dname_lf(k->buf, name, false); + if (ret) return kr_error(ret); + + knot_db_val_t key = key_exact_type(k, type); + knot_db_val_t val = { NULL, 0 }; + ret = cache_op(cache, read, &key, &val, 1); + if (!ret) ret = entry_h_seek(&val, type); + if (ret) return kr_error(ret); + + const struct entry_h *eh = entry_h_consistent_E(val, type); + if (!eh || eh->is_packet) { + // TODO: no packets, but better get rid of whole kr_cache_peek_exact(). + return kr_error(ENOENT); + } + *peek = (struct kr_cache_p){ + .time = eh->time, + .ttl = eh->ttl, + .rank = eh->rank, + .raw_data = val.data, + .raw_bound = knot_db_val_bound(val), + }; + return kr_ok(); +} +int kr_cache_peek_exact(struct kr_cache *cache, const knot_dname_t *name, uint16_t type, + struct kr_cache_p *peek) +{ /* Just wrap with extra verbose logging. */ + const int ret = peek_exact_real(cache, name, type, peek); + if (false && kr_log_is_debug(CACHE, NULL)) { /* too noisy for usual --verbose */ + auto_free char *type_str = kr_rrtype_text(type), + *name_str = kr_dname_text(name); + const char *result_str = (ret == kr_ok() ? "hit" : + (ret == kr_error(ENOENT) ? "miss" : "error")); + VERBOSE_MSG(NULL, "_peek_exact: %s %s %s (ret: %d)", + type_str, name_str, result_str, ret); + } + return ret; +} + +int kr_cache_remove(struct kr_cache *cache, const knot_dname_t *name, uint16_t type) +{ + if (!cache_isvalid(cache)) { + return kr_error(EINVAL); + } + if (!cache->api->remove) { + return kr_error(ENOSYS); + } + struct key k_storage, *k = &k_storage; + int ret = kr_dname_lf(k->buf, name, false); + if (ret) return kr_error(ret); + + knot_db_val_t key = key_exact_type(k, type); + return cache_op(cache, remove, &key, 1); +} + +int kr_cache_match(struct kr_cache *cache, const knot_dname_t *name, + bool exact_name, knot_db_val_t keyval[][2], int maxcount) +{ + if (!cache_isvalid(cache)) { + return kr_error(EINVAL); + } + if (!cache->api->match) { + return kr_error(ENOSYS); + } + + struct key k_storage, *k = &k_storage; + + int ret = kr_dname_lf(k->buf, name, false); + if (ret) return kr_error(ret); + + // use a mock type + knot_db_val_t key = key_exact_type(k, KNOT_RRTYPE_A); + /* CACHE_KEY_DEF */ + key.len -= sizeof(uint16_t); /* the type */ + if (!exact_name) { + key.len -= 2; /* '\0' 'E' */ + if (name[0] == '\0') ++key.len; /* the root name is special ATM */ + } + return cache_op(cache, match, &key, keyval, maxcount); +} + +int kr_unpack_cache_key(knot_db_val_t key, knot_dname_t *buf, uint16_t *type) +{ + if (key.data == NULL || buf == NULL || type == NULL) { + return kr_error(EINVAL); + } + + int len = -1; + const char *tag, *key_data = key.data; + for (tag = key_data + 1; tag < key_data + key.len; ++tag) { + /* CACHE_KEY_DEF */ + if (tag[-1] == '\0' && (tag == key_data + 1 || tag[-2] == '\0')) { + if (tag[0] != 'E') return kr_error(EINVAL); + len = tag - 1 - key_data; + break; + } + } + + if (len == -1 || len > KNOT_DNAME_MAXLEN) { + return kr_error(EINVAL); + } + + int ret = knot_dname_lf2wire(buf, len, key.data); + if (ret < 0) { + return kr_error(ret); + } + + /* CACHE_KEY_DEF: jump over "\0 E/1" */ + memcpy(type, tag + 1, sizeof(uint16_t)); + + return kr_ok(); +} + + +int kr_cache_remove_subtree(struct kr_cache *cache, const knot_dname_t *name, + bool exact_name, int maxcount) +{ + if (!cache_isvalid(cache)) { + return kr_error(EINVAL); + } + + knot_db_val_t keyval[maxcount][2], keys[maxcount]; + int ret = kr_cache_match(cache, name, exact_name, keyval, maxcount); + if (ret <= 0) { /* ENOENT -> nothing to remove */ + return (ret == KNOT_ENOENT) ? 0 : ret; + } + const int count = ret; + /* Duplicate the key strings, as deletion may invalidate the pointers. */ + int i; + for (i = 0; i < count; ++i) { + keys[i].len = keyval[i][0].len; + keys[i].data = malloc(keys[i].len); + if (!keys[i].data) { + ret = kr_error(ENOMEM); + goto cleanup; + } + memcpy(keys[i].data, keyval[i][0].data, keys[i].len); + } + ret = cache_op(cache, remove, keys, count); +cleanup: + kr_cache_commit(cache); /* Sync even after just kr_cache_match(). */ + /* Free keys */ + while (--i >= 0) { + free(keys[i].data); + } + return ret; +} + +static void health_timer_cb(uv_timer_t *health_timer) +{ + struct kr_cache *cache = health_timer->data; + if (cache) + cache_op(cache, check_health); + /* We don't do anything with the return code. For example, in some situations + * the file may not exist (temporarily), and we just expect to be more lucky + * when the timer fires again. */ +} + +int kr_cache_check_health(struct kr_cache *cache, int interval) +{ + if (interval == 0) + return cache_op(cache, check_health); + if (interval < 0) { + if (!cache->health_timer) + return kr_ok(); // tolerate stopping a "stopped" timer + uv_close((uv_handle_t *)cache->health_timer, (uv_close_cb)free); + cache->health_timer->data = NULL; + cache->health_timer = NULL; + return kr_ok(); + } + + if (!cache->health_timer) { + /* We avoid depending on daemon's symbols by using uv_default_loop. */ + cache->health_timer = malloc(sizeof(*cache->health_timer)); + if (!cache->health_timer) return kr_error(ENOMEM); + uv_loop_t *loop = uv_default_loop(); + kr_require(loop); + int ret = uv_timer_init(loop, cache->health_timer); + if (ret) { + free(cache->health_timer); + cache->health_timer = NULL; + return kr_error(ret); + } + cache->health_timer->data = cache; + } + kr_assert(cache->health_timer->data); + return kr_error(uv_timer_start(cache->health_timer, health_timer_cb, interval, interval)); +} + |