--- /dev/null
- target = knot_wire_next_label(target, NULL);
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <ctype.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <arpa/inet.h>
+#include <libknot/rrtype/rdname.h>
+#include <libknot/descriptor.h>
+#include <ucw/mempool.h>
+#include <sys/socket.h>
+#include "lib/resolve.h"
+#include "lib/layer.h"
+#include "lib/rplan.h"
+#include "lib/layer/iterate.h"
+#include "lib/dnssec/ta.h"
+#include "lib/dnssec.h"
+
+#include "lib/resolve-impl.h"
+
+/** @internal Find layer id matching API. */
+static inline size_t layer_id(struct kr_request *req, const struct kr_layer_api *api) {
+ module_array_t *modules = req->ctx->modules;
+ for (size_t i = 0; i < modules->len; ++i) {
+ if (modules->at[i]->layer == api) {
+ return i;
+ }
+ }
+ return 0; /* Not found, try all. */
+}
+
+/* @internal We don't need to deal with locale here */
+KR_CONST static inline bool isletter(unsigned chr)
+{ return (chr | 0x20 /* tolower */) - 'a' <= 'z' - 'a'; }
+
+void randomized_qname_case(knot_dname_t * restrict qname, uint32_t secret)
+{
+ if (secret == 0)
+ return;
+ if (kr_fails_assert(qname))
+ return;
+ const int len = knot_dname_size(qname) - 2; /* Skip first, last label. First is length, last is always root */
+ for (int i = 0; i < len; ++i) {
+ /* Note: this relies on the fact that correct label lengths
+ * can't pass the isletter() test (by "luck"). */
+ if (isletter(*++qname)) {
+ *qname ^= ((secret >> (i & 31)) & 1) * 0x20;
+ }
+ }
+}
+
+/** This turns off QNAME minimisation if there is a non-terminal between current zone cut, and name target.
+ * It save several minimization steps, as the zone cut is likely final one.
+ */
+static void check_empty_nonterms(struct kr_query *qry, knot_pkt_t *pkt, struct kr_cache *cache, uint32_t timestamp)
+{
+ // FIXME cleanup, etc.
+#if 0
+ if (qry->flags.NO_MINIMIZE) {
+ return;
+ }
+
+ const knot_dname_t *target = qry->sname;
+ const knot_dname_t *cut_name = qry->zone_cut.name;
+ if (!target || !cut_name)
+ return;
+
+ struct kr_cache_entry *entry = NULL;
+ /* @note: The non-terminal must be direct child of zone cut (e.g. label distance <= 2),
+ * otherwise this would risk leaking information to parent if the NODATA TTD > zone cut TTD. */
+ int labels = knot_dname_labels(target, NULL) - knot_dname_labels(cut_name, NULL);
+ while (target[0] && labels > 2) {
- target = knot_wire_next_label(target, NULL);
++ target = knot_dname_next_label(target);
+ --labels;
+ }
+ for (int i = 0; i < labels; ++i) {
+ int ret = kr_cache_peek(cache, KR_CACHE_PKT, target, KNOT_RRTYPE_NS, &entry, ×tamp);
+ if (ret == 0) { /* Either NXDOMAIN or NODATA, start here. */
+ /* @todo We could stop resolution here for NXDOMAIN, but we can't because of broken CDNs */
+ qry->flags.NO_MINIMIZE = true;
+ kr_make_query(qry, pkt);
+ break;
+ }
+ kr_assert(target[0]);
- wanted_name = knot_wire_next_label(wanted_name, NULL);
++ target = knot_dname_next_label(target);
+ }
+ kr_cache_commit(cache);
+#endif
+}
+
+static int ns_fetch_cut(struct kr_query *qry, const knot_dname_t *requested_name,
+ struct kr_request *req, knot_pkt_t *pkt)
+{
+ /* It can occur that here parent query already have
+ * provably insecure zonecut which not in the cache yet. */
+ struct kr_qflags pflags;
+ if (qry->parent) {
+ pflags = qry->parent->flags;
+ }
+ const bool is_insecure = qry->parent != NULL
+ && !(pflags.AWAIT_IPV4 || pflags.AWAIT_IPV6)
+ && (pflags.DNSSEC_INSECURE || pflags.DNSSEC_NODS);
+
+ /* Want DNSSEC if it's possible to secure this name
+ * (e.g. is covered by any TA) */
+ if (is_insecure) {
+ /* If parent is insecure we don't want DNSSEC
+ * even if cut name is covered by TA. */
+ qry->flags.DNSSEC_WANT = false;
+ qry->flags.DNSSEC_INSECURE = true;
+ VERBOSE_MSG(qry, "=> going insecure because parent query is insecure\n");
+ } else if (kr_ta_closest(req->ctx, qry->zone_cut.name, KNOT_RRTYPE_NS)) {
+ qry->flags.DNSSEC_WANT = true;
+ } else {
+ qry->flags.DNSSEC_WANT = false;
+ VERBOSE_MSG(qry, "=> going insecure because there's no covering TA\n");
+ }
+
+ struct kr_zonecut cut_found;
+ kr_zonecut_init(&cut_found, requested_name, req->rplan.pool);
+ /* Cut that has been found can differs from cut that has been requested.
+ * So if not already insecure,
+ * try to fetch ta & keys even if initial cut name not covered by TA */
+ bool secure = !is_insecure;
+ int ret = kr_zonecut_find_cached(req->ctx, &cut_found, requested_name,
+ qry, &secure);
+ if (ret == kr_error(ENOENT)) {
+ /* No cached cut found, start from SBELT
+ * and issue priming query. */
+ kr_zonecut_deinit(&cut_found);
+ ret = kr_zonecut_set_sbelt(req->ctx, &qry->zone_cut);
+ if (ret != 0) {
+ return KR_STATE_FAIL;
+ }
+ VERBOSE_MSG(qry, "=> using root hints\n");
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_DONE;
+ } else if (ret != kr_ok()) {
+ kr_zonecut_deinit(&cut_found);
+ return KR_STATE_FAIL;
+ }
+
+ /* Find out security status.
+ * Go insecure if the zone cut is provably insecure */
+ if ((qry->flags.DNSSEC_WANT) && !secure) {
+ VERBOSE_MSG(qry, "=> NS is provably without DS, going insecure\n");
+ qry->flags.DNSSEC_WANT = false;
+ qry->flags.DNSSEC_INSECURE = true;
+ }
+ /* Zonecut name can change, check it again
+ * to prevent unnecessary DS & DNSKEY queries */
+ if (!(qry->flags.DNSSEC_INSECURE) &&
+ kr_ta_closest(req->ctx, cut_found.name, KNOT_RRTYPE_NS)) {
+ qry->flags.DNSSEC_WANT = true;
+ } else {
+ qry->flags.DNSSEC_WANT = false;
+ }
+ /* Check if any DNSKEY found for cached cut */
+ if (qry->flags.DNSSEC_WANT && cut_found.key == NULL &&
+ kr_zonecut_is_empty(&cut_found)) {
+ /* Cut found and there are no proofs of zone insecurity.
+ * But no DNSKEY found and no glue fetched.
+ * We have got circular dependency - must fetch A\AAAA
+ * from authoritative, but we have no key to verify it. */
+ kr_zonecut_deinit(&cut_found);
+ if (requested_name[0] != '\0' ) {
+ /* If not root - try next label */
+ return KR_STATE_CONSUME;
+ }
+ /* No cached cut & keys found, start from SBELT */
+ ret = kr_zonecut_set_sbelt(req->ctx, &qry->zone_cut);
+ if (ret != 0) {
+ return KR_STATE_FAIL;
+ }
+ VERBOSE_MSG(qry, "=> using root hints\n");
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_DONE;
+ }
+ /* Use the found zone cut. */
+ kr_zonecut_move(&qry->zone_cut, &cut_found);
+ /* Check if there's a non-terminal between target and current cut. */
+ struct kr_cache *cache = &req->ctx->cache;
+ check_empty_nonterms(qry, pkt, cache, qry->timestamp.tv_sec);
+ /* Cut found */
+ return KR_STATE_PRODUCE;
+}
+
+/** @internal Spawn subrequest in current zone cut (no minimization or lookup). */
+static struct kr_query *zone_cut_subreq(struct kr_rplan *rplan, struct kr_query *parent,
+ const knot_dname_t *qname, uint16_t qtype)
+{
+ struct kr_query *next = kr_rplan_push(rplan, parent, qname, parent->sclass, qtype);
+ if (!next) {
+ return NULL;
+ }
+ kr_zonecut_set(&next->zone_cut, parent->zone_cut.name);
+ if (kr_zonecut_copy(&next->zone_cut, &parent->zone_cut) != 0 ||
+ kr_zonecut_copy_trust(&next->zone_cut, &parent->zone_cut) != 0) {
+ return NULL;
+ }
+ next->flags.NO_MINIMIZE = true;
+ if (parent->flags.DNSSEC_WANT) {
+ next->flags.DNSSEC_WANT = true;
+ }
+ return next;
+}
+
+static int forward_trust_chain_check(struct kr_request *request, struct kr_query *qry, bool resume)
+{
+ struct kr_rplan *rplan = &request->rplan;
+ trie_t *trust_anchors = request->ctx->trust_anchors;
+ trie_t *negative_anchors = request->ctx->negative_anchors;
+
+ if (qry->parent != NULL &&
+ !(qry->forward_flags.CNAME) &&
+ !(qry->flags.DNS64_MARK) &&
+ knot_dname_in_bailiwick(qry->zone_cut.name, qry->parent->zone_cut.name) >= 0) {
+ return KR_STATE_PRODUCE;
+ }
+
+ if (kr_fails_assert(qry->flags.FORWARD))
+ return KR_STATE_FAIL;
+
+ if (!trust_anchors) {
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_PRODUCE;
+ }
+
+ if (qry->flags.DNSSEC_INSECURE) {
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_PRODUCE;
+ }
+
+ if (qry->forward_flags.NO_MINIMIZE) {
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_PRODUCE;
+ }
+
+ const knot_dname_t *start_name = qry->sname;
+ if ((qry->flags.AWAIT_CUT) && !resume) {
+ qry->flags.AWAIT_CUT = false;
+ const knot_dname_t *longest_ta = kr_ta_closest(request->ctx, qry->sname, qry->stype);
+ if (longest_ta) {
+ start_name = longest_ta;
+ qry->zone_cut.name = knot_dname_copy(start_name, qry->zone_cut.pool);
+ qry->flags.DNSSEC_WANT = true;
+ } else {
+ qry->flags.DNSSEC_WANT = false;
+ return KR_STATE_PRODUCE;
+ }
+ }
+
+ bool has_ta = (qry->zone_cut.trust_anchor != NULL);
+ knot_dname_t *ta_name = (has_ta ? qry->zone_cut.trust_anchor->owner : NULL);
+ bool refetch_ta = (!has_ta || !knot_dname_is_equal(qry->zone_cut.name, ta_name));
+ bool is_dnskey_subreq = kr_rplan_satisfies(qry, ta_name, KNOT_CLASS_IN, KNOT_RRTYPE_DNSKEY);
+ bool refetch_key = has_ta && (!qry->zone_cut.key || !knot_dname_is_equal(ta_name, qry->zone_cut.key->owner));
+ if (refetch_key && !is_dnskey_subreq) {
+ struct kr_query *next = zone_cut_subreq(rplan, qry, ta_name, KNOT_RRTYPE_DNSKEY);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ return KR_STATE_DONE;
+ }
+
+ int name_offset = 1;
+ const knot_dname_t *wanted_name;
+ bool nods, ds_req, ns_req, minimized, ns_exist;
+ do {
+ wanted_name = start_name;
+ ds_req = false;
+ ns_req = false;
+ ns_exist = true;
+
+ int cut_labels = knot_dname_labels(qry->zone_cut.name, NULL);
+ int wanted_name_labels = knot_dname_labels(wanted_name, NULL);
+ while (wanted_name[0] && wanted_name_labels > cut_labels + name_offset) {
- requested_name = knot_wire_next_label(parent, NULL);
++ wanted_name = knot_dname_next_label(wanted_name);
+ wanted_name_labels -= 1;
+ }
+ minimized = (wanted_name != qry->sname);
+
+ for (int i = 0; i < request->rplan.resolved.len; ++i) {
+ struct kr_query *q = request->rplan.resolved.at[i];
+ if (q->parent == qry &&
+ q->sclass == qry->sclass &&
+ (q->stype == KNOT_RRTYPE_DS || q->stype == KNOT_RRTYPE_NS) &&
+ knot_dname_is_equal(q->sname, wanted_name)) {
+ if (q->stype == KNOT_RRTYPE_DS) {
+ ds_req = true;
+ if (q->flags.CNAME) {
+ ns_exist = false;
+ } else if (!(q->flags.DNSSEC_OPTOUT)) {
+ int ret = kr_dnssec_matches_name_and_type(&request->auth_selected, q->uid,
+ wanted_name, KNOT_RRTYPE_NS);
+ ns_exist = (ret == kr_ok());
+ }
+ } else {
+ if (q->flags.CNAME) {
+ ns_exist = false;
+ }
+ ns_req = true;
+ }
+ }
+ }
+
+ if (ds_req && ns_exist && !ns_req && (minimized || resume)) {
+ struct kr_query *next = zone_cut_subreq(rplan, qry, wanted_name,
+ KNOT_RRTYPE_NS);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ return KR_STATE_DONE;
+ }
+
+ if (qry->parent == NULL && (qry->flags.CNAME) &&
+ ds_req && ns_req) {
+ return KR_STATE_PRODUCE;
+ }
+
+ /* set `nods` */
+ if ((qry->stype == KNOT_RRTYPE_DS) &&
+ knot_dname_is_equal(wanted_name, qry->sname)) {
+ nods = true;
+ } else if (resume && !ds_req) {
+ nods = false;
+ } else if (!minimized && qry->stype != KNOT_RRTYPE_DNSKEY) {
+ nods = true;
+ } else {
+ nods = ds_req;
+ }
+ name_offset += 1;
+ } while (ds_req && (ns_req || !ns_exist) && minimized);
+
+ /* Disable DNSSEC if it enters NTA. */
+ if (kr_ta_get(negative_anchors, wanted_name)){
+ VERBOSE_MSG(qry, ">< negative TA, going insecure\n");
+ qry->flags.DNSSEC_WANT = false;
+ }
+
+ /* Enable DNSSEC if enters a new island of trust. */
+ bool want_secure = (qry->flags.DNSSEC_WANT) &&
+ !knot_wire_get_cd(request->qsource.packet->wire);
+ if (!(qry->flags.DNSSEC_WANT) &&
+ !knot_wire_get_cd(request->qsource.packet->wire) &&
+ kr_ta_get(trust_anchors, wanted_name)) {
+ qry->flags.DNSSEC_WANT = true;
+ want_secure = true;
+ if (kr_log_is_debug_qry(RESOLVER, qry)) {
+ KR_DNAME_GET_STR(qname_str, wanted_name);
+ VERBOSE_MSG(qry, ">< TA: '%s'\n", qname_str);
+ }
+ }
+
+ if (want_secure && !qry->zone_cut.trust_anchor) {
+ knot_rrset_t *ta_rr = kr_ta_get(trust_anchors, wanted_name);
+ if (!ta_rr) {
+ char name[] = "\0";
+ ta_rr = kr_ta_get(trust_anchors, (knot_dname_t*)name);
+ }
+ if (ta_rr) {
+ qry->zone_cut.trust_anchor = knot_rrset_copy(ta_rr, qry->zone_cut.pool);
+ }
+ }
+
+ has_ta = (qry->zone_cut.trust_anchor != NULL);
+ ta_name = (has_ta ? qry->zone_cut.trust_anchor->owner : NULL);
+ refetch_ta = (!has_ta || !knot_dname_is_equal(wanted_name, ta_name));
+ if (!nods && want_secure && refetch_ta) {
+ struct kr_query *next = zone_cut_subreq(rplan, qry, wanted_name,
+ KNOT_RRTYPE_DS);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ return KR_STATE_DONE;
+ }
+
+ /* Try to fetch missing DNSKEY.
+ * Do not fetch if this is a DNSKEY subrequest to avoid circular dependency. */
+ is_dnskey_subreq = kr_rplan_satisfies(qry, ta_name, KNOT_CLASS_IN, KNOT_RRTYPE_DNSKEY);
+ refetch_key = has_ta && (!qry->zone_cut.key || !knot_dname_is_equal(ta_name, qry->zone_cut.key->owner));
+ if (want_secure && refetch_key && !is_dnskey_subreq) {
+ struct kr_query *next = zone_cut_subreq(rplan, qry, ta_name, KNOT_RRTYPE_DNSKEY);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ return KR_STATE_DONE;
+ }
+
+ return KR_STATE_PRODUCE;
+}
+
+/* @todo: Validator refactoring, keep this in driver for now. */
+static int trust_chain_check(struct kr_request *request, struct kr_query *qry)
+{
+ struct kr_rplan *rplan = &request->rplan;
+ trie_t *trust_anchors = request->ctx->trust_anchors;
+ trie_t *negative_anchors = request->ctx->negative_anchors;
+
+ /* Disable DNSSEC if it enters NTA. */
+ if (kr_ta_get(negative_anchors, qry->zone_cut.name)){
+ VERBOSE_MSG(qry, ">< negative TA, going insecure\n");
+ qry->flags.DNSSEC_WANT = false;
+ qry->flags.DNSSEC_INSECURE = true;
+ }
+ if (qry->flags.DNSSEC_NODS) {
+ /* This is the next query iteration with minimized qname.
+ * At previous iteration DS non-existence has been proven */
+ VERBOSE_MSG(qry, "<= DS doesn't exist, going insecure\n");
+ qry->flags.DNSSEC_NODS = false;
+ qry->flags.DNSSEC_WANT = false;
+ qry->flags.DNSSEC_INSECURE = true;
+ }
+ /* Enable DNSSEC if entering a new (or different) island of trust,
+ * and update the TA RRset if required. */
+ const bool has_cd = knot_wire_get_cd(request->qsource.packet->wire);
+ knot_rrset_t *ta_rr = kr_ta_get(trust_anchors, qry->zone_cut.name);
+ if (!has_cd && ta_rr) {
+ qry->flags.DNSSEC_WANT = true;
+ if (qry->zone_cut.trust_anchor == NULL
+ || !knot_dname_is_equal(qry->zone_cut.trust_anchor->owner, qry->zone_cut.name)) {
+ mm_free(qry->zone_cut.pool, qry->zone_cut.trust_anchor);
+ qry->zone_cut.trust_anchor = knot_rrset_copy(ta_rr, qry->zone_cut.pool);
+
+ if (kr_log_is_debug_qry(RESOLVER, qry)) {
+ KR_DNAME_GET_STR(qname_str, ta_rr->owner);
+ VERBOSE_MSG(qry, ">< TA: '%s'\n", qname_str);
+ }
+ }
+ }
+
+ /* Try to fetch missing DS (from above the cut). */
+ const bool has_ta = (qry->zone_cut.trust_anchor != NULL);
+ const knot_dname_t *ta_name = (has_ta ? qry->zone_cut.trust_anchor->owner : NULL);
+ const bool refetch_ta = !has_ta || !knot_dname_is_equal(qry->zone_cut.name, ta_name);
+ const bool want_secure = qry->flags.DNSSEC_WANT && !has_cd;
+ if (want_secure && refetch_ta) {
+ /* @todo we could fetch the information from the parent cut, but we don't remember that now */
+ struct kr_query *next = kr_rplan_push(rplan, qry, qry->zone_cut.name, qry->sclass, KNOT_RRTYPE_DS);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ next->flags.AWAIT_CUT = true;
+ next->flags.DNSSEC_WANT = true;
+ return KR_STATE_DONE;
+ }
+ /* Try to fetch missing DNSKEY (either missing or above current cut).
+ * Do not fetch if this is a DNSKEY subrequest to avoid circular dependency. */
+ const bool is_dnskey_subreq = kr_rplan_satisfies(qry, ta_name, KNOT_CLASS_IN, KNOT_RRTYPE_DNSKEY);
+ const bool refetch_key = has_ta && (!qry->zone_cut.key || !knot_dname_is_equal(ta_name, qry->zone_cut.key->owner));
+ if (want_secure && refetch_key && !is_dnskey_subreq) {
+ struct kr_query *next = zone_cut_subreq(rplan, qry, ta_name, KNOT_RRTYPE_DNSKEY);
+ if (!next) {
+ return KR_STATE_FAIL;
+ }
+ return KR_STATE_DONE;
+ }
+
+ return KR_STATE_PRODUCE;
+}
+
+/// Check current zone cut status and credibility, spawn subrequests if needed.
+/// \return KR_STATE_FAIL, KR_STATE_DONE, kr_ok()
+/// TODO: careful review might be nice
+static int zone_cut_check(struct kr_request *request, struct kr_query *qry, knot_pkt_t *packet)
+{
+ // Set up nameserver+cut if overridden by policy.
+ int ret = kr_rule_data_src_check(qry, packet);
+ if (ret) return KR_STATE_FAIL;
+
+ /* Stub mode, just forward and do not solve cut. */
+ if (qry->flags.STUB) {
+ return KR_STATE_PRODUCE;
+ }
+
+ /* Forwarding to upstream resolver mode.
+ * Since forwarding targets already are in qry->ns -
+ * cut fetching is not needed. */
+ if (qry->flags.FORWARD) {
+ return forward_trust_chain_check(request, qry, false);
+ }
+ if (!(qry->flags.AWAIT_CUT)) {
+ /* The query was resolved from cache.
+ * Spawn DS \ DNSKEY requests if needed and exit */
+ return trust_chain_check(request, qry);
+ }
+
+ /* The query wasn't resolved from cache,
+ * now it's the time to look up closest zone cut from cache. */
+ struct kr_cache *cache = &request->ctx->cache;
+ if (!kr_cache_is_open(cache)) {
+ ret = kr_zonecut_set_sbelt(request->ctx, &qry->zone_cut);
+ if (ret != 0) {
+ return KR_STATE_FAIL;
+ }
+ VERBOSE_MSG(qry, "=> no cache open, using root hints\n");
+ qry->flags.AWAIT_CUT = false;
+ return KR_STATE_DONE;
+ }
+
+ const knot_dname_t *requested_name = qry->sname;
+ /* If at/subdomain of parent zone cut, start from its encloser.
+ * This is for case when we get to a dead end
+ * (and need glue from parent), or DS refetch. */
+ if (qry->parent) {
+ const knot_dname_t *parent = qry->parent->zone_cut.name;
+ if (parent[0] != '\0'
+ && knot_dname_in_bailiwick(qry->sname, parent) >= 0) {
- } else if ((qry->stype == KNOT_RRTYPE_DS) && (qry->sname[0] != '\0')) {
++ requested_name = knot_dname_next_label(parent);
+ }
- requested_name = knot_wire_next_label(requested_name, NULL);
++ } else if ((qry->stype == KNOT_RRTYPE_DS) && (requested_name[0] != '\0')) {
+ /* If this is explicit DS query, start from encloser too. */
- requested_name = knot_wire_next_label(requested_name, NULL);
++ requested_name = knot_dname_next_label(requested_name);
+ }
+
+ int state = KR_STATE_FAIL;
+ do {
+ state = ns_fetch_cut(qry, requested_name, request, packet);
+ if (state == KR_STATE_DONE || (state & KR_STATE_FAIL)) {
+ return state;
+ } else if (state == KR_STATE_CONSUME) {
++ kr_require(requested_name[0] != '\0');
++ requested_name = knot_dname_next_label(requested_name);
+ }
+ } while (state == KR_STATE_CONSUME);
+
+ /* Update minimized QNAME if zone cut changed */
+ if (qry->zone_cut.name && qry->zone_cut.name[0] != '\0' && !(qry->flags.NO_MINIMIZE)) {
+ if (kr_make_query(qry, packet) != 0) {
+ return KR_STATE_FAIL;
+ }
+ }
+ qry->flags.AWAIT_CUT = false;
+
+ /* Check trust chain */
+ return trust_chain_check(request, qry);
+}
+
+
+static int ns_resolve_addr(struct kr_query *qry, struct kr_request *param, struct kr_transport *transport, uint16_t next_type)
+{
+ struct kr_rplan *rplan = ¶m->rplan;
+ struct kr_context *ctx = param->ctx;
+
+
+ /* Start NS queries from root, to avoid certain cases
+ * where a NS drops out of cache and the rest is unavailable,
+ * this would lead to dependency loop in current zone cut.
+ */
+
+ /* Bail out if the query is already pending or dependency loop. */
+ if (!next_type || kr_rplan_satisfies(qry->parent, transport->ns_name, KNOT_CLASS_IN, next_type)) {
+ /* Fall back to SBELT if root server query fails. */
+ if (!next_type && qry->zone_cut.name[0] == '\0') {
+ VERBOSE_MSG(qry, "=> fallback to root hints\n");
+ kr_zonecut_set_sbelt(ctx, &qry->zone_cut);
+ return kr_error(EAGAIN);
+ }
+ /* No IPv4 nor IPv6, flag server as unusable. */
+ VERBOSE_MSG(qry, "=> unresolvable NS address, bailing out\n");
+ kr_zonecut_del_all(&qry->zone_cut, transport->ns_name);
+ return kr_error(EHOSTUNREACH);
+ }
+ /* Push new query to the resolution plan */
+ struct kr_query *next =
+ kr_rplan_push(rplan, qry, transport->ns_name, KNOT_CLASS_IN, next_type);
+ if (!next) {
+ return kr_error(ENOMEM);
+ }
+ next->flags.NONAUTH = true;
+
+ /* At the root level with no NS addresses, add SBELT subrequest. */
+ int ret = 0;
+ if (qry->zone_cut.name[0] == '\0') {
+ ret = kr_zonecut_set_sbelt(ctx, &next->zone_cut);
+ if (ret == 0) { /* Copy TA and key since it's the same cut to avoid lookup. */
+ kr_zonecut_copy_trust(&next->zone_cut, &qry->zone_cut);
+ kr_zonecut_set_sbelt(ctx, &qry->zone_cut); /* Add SBELT to parent in case query fails. */
+ }
+ } else {
+ next->flags.AWAIT_CUT = true;
+ }
+
+ if (ret == 0) {
+ if (next_type == KNOT_RRTYPE_AAAA) {
+ qry->flags.AWAIT_IPV6 = true;
+ } else {
+ qry->flags.AWAIT_IPV4 = true;
+ }
+ }
+
+ return ret;
+}
+
+int kr_resolve_produce(struct kr_request *request, struct kr_transport **transport, knot_pkt_t *packet)
+{
+ kr_require(request && transport && packet);
+ struct kr_rplan *rplan = &request->rplan;
+
+ /* No query left for resolution */
+ if (kr_rplan_empty(rplan)) {
+ return KR_STATE_FAIL;
+ }
+
+ struct kr_query *qry = array_tail(rplan->pending);
+
+ /* If we have deferred answers, resume them. */
+ if (qry->deferred != NULL) {
+ /* @todo: Refactoring validator, check trust chain before resuming. */
+ int state = 0;
+ if (((qry->flags.FORWARD) == 0) ||
+ ((qry->stype == KNOT_RRTYPE_DS) && (qry->flags.CNAME))) {
+ state = trust_chain_check(request, qry);
+ } else {
+ state = forward_trust_chain_check(request, qry, true);
+ }
+
+ switch(state) {
+ case KR_STATE_FAIL: return KR_STATE_FAIL;
+ case KR_STATE_DONE: return KR_STATE_PRODUCE;
+ default: break;
+ }
+ VERBOSE_MSG(qry, "=> resuming yielded answer\n");
+ struct kr_layer_pickle *pickle = qry->deferred;
+ request->state = KR_STATE_YIELD;
+ set_yield(&request->answ_selected, qry->uid, false);
+ set_yield(&request->auth_selected, qry->uid, false);
+ RESUME_LAYERS(layer_id(request, pickle->api), request, qry, consume, pickle->pkt);
+ if (request->state != KR_STATE_YIELD) {
+ /* No new deferred answers, take the next */
+ qry->deferred = pickle->next;
+ }
+ } else {
+ /* Caller is interested in always tracking a zone cut, even if the answer is cached
+ * this is normally not required, and incurs another cache lookups for cached answer. */
+ if (qry->flags.ALWAYS_CUT) { // LATER: maybe the flag doesn't work well anymore
+ switch(zone_cut_check(request, qry, packet)) {
+ case KR_STATE_FAIL: return KR_STATE_FAIL;
+ case KR_STATE_DONE: return KR_STATE_PRODUCE;
+ default: break;
+ }
+ }
+ /* Resolve current query and produce dependent or finish */
+ request->state = KR_STATE_PRODUCE;
+ ITERATE_LAYERS(request, qry, produce, packet);
+ if (!(request->state & KR_STATE_FAIL) && knot_wire_get_qr(packet->wire)) {
+ /* Produced an answer from cache, consume it. */
+ kr_server_selection_cached(qry);
+ qry->secret = 0;
+ request->state = KR_STATE_CONSUME;
+ ITERATE_LAYERS(request, qry, consume, packet);
+ }
+ }
+ switch(request->state) {
+ case KR_STATE_FAIL: return request->state;
+ case KR_STATE_CONSUME: break;
+ case KR_STATE_DONE:
+ default: /* Current query is done */
+ if (qry->flags.RESOLVED && request->state != KR_STATE_YIELD) {
+ kr_rplan_pop(rplan, qry);
+ }
+ ITERATE_LAYERS(request, qry, reset);
+ return kr_rplan_empty(rplan) ? KR_STATE_DONE : KR_STATE_PRODUCE;
+ }
+ /* At this point we need to send a query upstream to proceed towards success. */
+
+ /* This query has RD=0 or is ANY, stop here. */
+ if (qry->stype == KNOT_RRTYPE_ANY ||
+ !knot_wire_get_rd(request->qsource.packet->wire)) {
+ VERBOSE_MSG(qry, "=> qtype is ANY or RD=0, bail out\n");
+ return KR_STATE_FAIL;
+ }
+
+ /* Update zone cut, spawn new subrequests. */
+ int state = zone_cut_check(request, qry, packet);
+ switch(state) {
+ case KR_STATE_FAIL: return KR_STATE_FAIL;
+ case KR_STATE_DONE: return KR_STATE_PRODUCE;
+ default: break;
+ }
+
+ const struct kr_qflags qflg = qry->flags;
+ const bool retry = qflg.TCP || qflg.BADCOOKIE_AGAIN;
+ if (!qflg.FORWARD && !qflg.STUB && !retry) { /* Keep NS when requerying/stub/badcookie. */
+ /* Root DNSKEY must be fetched from the hints to avoid chicken and egg problem. */
+ if (qry->sname[0] == '\0' && qry->stype == KNOT_RRTYPE_DNSKEY) {
+ kr_zonecut_set_sbelt(request->ctx, &qry->zone_cut);
+ }
+ }
+
+ qry->server_selection.choose_transport(qry, transport);
+
+ if (*transport == NULL) {
+ /* Properly signal to serve_stale module. */
+ if (qry->flags.NO_NS_FOUND) {
+ ITERATE_LAYERS(request, qry, reset);
+ kr_rplan_pop(rplan, qry);
+ return KR_STATE_FAIL;
+ } else {
+ /* FIXME: This is probably quite inefficient:
+ * we go through the whole qr_task_step loop just because of the serve_stale
+ * module which might not even be loaded. */
+ qry->flags.NO_NS_FOUND = true;
+ return KR_STATE_PRODUCE;
+ }
+ }
+
+ if ((*transport)->protocol == KR_TRANSPORT_RESOLVE_A || (*transport)->protocol == KR_TRANSPORT_RESOLVE_AAAA) {
+ uint16_t type = (*transport)->protocol == KR_TRANSPORT_RESOLVE_A ? KNOT_RRTYPE_A : KNOT_RRTYPE_AAAA;
+ ns_resolve_addr(qry, qry->request, *transport, type);
+ ITERATE_LAYERS(request, qry, reset);
+ return KR_STATE_PRODUCE;
+ }
+
+ /* Randomize query case (if not in not turned off) */
+ qry->secret = qry->flags.NO_0X20 ? 0 : kr_rand_bytes(sizeof(qry->secret));
+ knot_dname_t *qname_raw = kr_pkt_qname_raw(packet);
+ randomized_qname_case(qname_raw, qry->secret);
+
+ /*
+ * Additional query is going to be finalized when calling
+ * kr_resolve_checkout().
+ */
+ qry->timestamp_mono = kr_now();
+ return request->state;
+}
+
--- /dev/null
- --labels, apex = knot_wire_next_label(apex, NULL));
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "lib/rules/api.h"
+#include "lib/rules/impl.h"
+
+#include "lib/layer/iterate.h"
+#include "lib/resolve.h"
+
+static void setup_fwd_flags(struct kr_query *qry)
+{
+ if (qry->flags.FORWARD || qry->flags.STUB)
+ return; // someone else has set it unexpectedly - policy?
+ // TODO: disallow or restrict somehow?
+ //if (kr_fails_assert(!qry->flags.FORWARD && !qry->flags.STUB))
+
+ if (!qry->data_src.initialized) {
+ // no VAL_ZLAT_FORWARD -> standard iteration
+ qry->data_src.initialized = true;
+ qry->data_src.rule_depth = 0;
+ qry->data_src.flags.is_auth = true;
+ return;
+ }
+
+ const kr_rule_fwd_flags_t zf = qry->data_src.flags;
+
+ qry->flags.TCP |= zf.is_tcp;
+
+ if (!zf.is_auth && !zf.is_nods) { // mostly like policy.(TLS_)FORWARD
+ qry->flags.FORWARD = true;
+ qry->flags.NO_MINIMIZE = true;
+ // this ^^ probably won't be needed after moving iterator's produce
+ return;
+ }
+
+ if (!zf.is_auth && zf.is_nods) { // mostly like policy.STUB
+ qry->flags.STUB = true;
+ return;
+ }
+
+ if (zf.is_auth) {
+ return;
+ }
+
+ kr_require(false);
+}
+
+// Wrapper around rule_local_data_answer() to finish forwarding-related flags.
+int kr_rule_local_data_answer(struct kr_query *qry, knot_pkt_t *pkt)
+{
+ int ret = rule_local_data_answer(qry, pkt); // the main body of work
+ if (ret < 0)
+ kr_log_debug(RULES, "policy rules failed: %s\n", kr_strerror(ret));
+ // deal with setting up .FORWARD and .STUB, so that cache lookup knows
+ setup_fwd_flags(qry);
+ // unfortunately, changing flags can change this from iterator
+ if (ret == 0 && (qry->flags.FORWARD || qry->flags.STUB))
+ ret = kr_make_query(qry, pkt);
+
+ //kr_assert(qry->data_src.initialized); // TODO: broken by old policy.FORWARD, etc.
+ return ret;
+}
+
+int kr_rule_data_src_check(struct kr_query *qry, struct knot_pkt *pkt)
+{
+ if (qry->data_src.all_set)
+ return kr_ok(); // everything should be in order from before
+
+ if (/*kr_fails_assert!*/(!qry->data_src.initialized)) { // FIXME ci val_ad_qtype_ds
+ // fall back to standard iteration
+ goto fallback;
+ }
+
+ if (!qry->data_src.flags.is_auth && qry->data_src.targets_ptr.data) {
+ struct kr_request *req = qry->request;
+ // In old policy this used to be done by kr_forward_add_target()
+ // For TLS see policy.TLS_FORWARD() and net_tls_client()
+ // The mapping from address+port to parameters are in tls_client_param_t
+ kr_sockaddr_array_t *targets = &req->selection_context.forwarding_targets;
+ const size_t t_bytes = qry->data_src.targets_ptr.len;
+ kr_assert(t_bytes > 0 && t_bytes % sizeof(targets->at[0]) == 0);
+ targets->cap = targets->len = t_bytes / sizeof(targets->at[0]);
+ targets->at = mm_alloc(&req->pool, t_bytes);
+ memcpy(targets->at, qry->data_src.targets_ptr.data, t_bytes);
+ qry->data_src.all_set = true;
+
+ kr_server_selection_init(qry); // this assumes `forwarding_targets` was filled
+ return kr_ok();
+ }
+
+ if (qry->data_src.flags.is_auth) {
+ if (!qry->data_src.targets_ptr.data)
+ goto fallback; // default iteration falls here
+ const knot_dname_t *apex = qry->sname;
+ for (int labels = knot_dname_labels(apex, NULL);
+ labels > qry->data_src.rule_depth;
++ --labels, apex = knot_dname_next_label(apex));
+ kr_zonecut_set(&qry->zone_cut, apex);
+ qry->zone_cut.avoid_resolving = true;
+ knot_db_val_t targets = qry->data_src.targets_ptr;
+ kr_assert(targets.len > 0);
+ while (targets.len > 0) {
+ union kr_sockaddr target;
+ if (deserialize_fails_assert(&targets, &target))
+ goto fallback;
+ int ret = kr_zonecut_add(&qry->zone_cut,
+ (const knot_dname_t *)"\2ns\7invalid",
+ kr_inaddr(&target.ip), kr_inaddr_len(&target.ip));
+ if (kr_fails_assert(ret == 0))
+ goto fallback;
+ }
+ kr_assert(targets.len == 0);
+ qry->flags.AWAIT_CUT = false;
+ qry->data_src.all_set = true;
+ kr_server_selection_init(qry);
+ // unfortunately, zone cut depth might've changed
+ return kr_make_query(qry, pkt);
+ }
+
+ kr_assert(false);
+fallback:
+ qry->data_src.initialized = true;
+ qry->data_src.rule_depth = 0;
+ qry->data_src.all_set = true;
+ kr_server_selection_init(qry);
+ return kr_ok();
+}
+
+int kr_rule_forward(const knot_dname_t *apex, kr_rule_fwd_flags_t flags,
+ const struct sockaddr * targets[])
+{
+ ENSURE_the_rules;
+ const kr_rule_tags_t tags = KR_RULE_TAGS_ALL;
+ const val_zla_type_t ztype = VAL_ZLAT_FORWARD;
+
+ int count = 0;
+ if (targets) {
+ while (targets[count])
+ ++count;
+ }
+
+ uint8_t key_data[KEY_MAXLEN];
+ knot_db_val_t key = zla_key(apex, key_data);
+
+ // Prepare the data into a temporary buffer.
+ const int targets_len = count * sizeof(union kr_sockaddr);
+ const int val_len = sizeof(tags) + sizeof(ztype) + sizeof(flags) + targets_len;
+ uint8_t buf[val_len], *data = buf;
+ memcpy(data, &tags, sizeof(tags));
+ data += sizeof(tags);
+ memcpy(data, &ztype, sizeof(ztype));
+ data += sizeof(ztype);
+ memcpy(data, &flags, sizeof(flags));
+ data += sizeof(flags);
+ // targets[i] may be shorter than union kr_sockaddr, so we zero it in advance
+ memset(data, 0, targets_len);
+ for (int i = 0; i < count; ++i) {
+ // LATER: for is_auth we really drop anything but address (e.g. port!=53)
+ memcpy(data, targets[i], kr_sockaddr_len(targets[i]));
+ data += sizeof(union kr_sockaddr);
+ }
+ kr_require(data == buf + val_len);
+
+ // We don't allow combining forwarding rule with anything else
+ // on the same apex, including another forwarding rule (at least not yet).
+ int ret = ruledb_op(remove, &key, 1);
+ kr_assert(ret == 0 || ret == 1);
+ knot_db_val_t val = { .data = buf, .len = val_len };
+ ret = ruledb_op(write, &key, &val, 1);
+ // ENOSPC seems to be the only expectable error.
+ kr_assert(ret == 0 || ret == kr_error(ENOSPC));
+ return ret;
+}
projects / thirdparty / knot-resolver.git / commitdiff
