#define DEBUG_MSG(fmt, ...) fprintf(stderr, "[qiter] " fmt, ## __VA_ARGS__)
-/*! \brief Fetch NS record address from additionals. */
-static int glue_ns_addr(const knot_pkt_t *pkt, struct sockaddr_storage *addr, const knot_dname_t *name, uint16_t type)
-{
- const knot_pktsection_t *ar = knot_pkt_section(pkt, KNOT_ADDITIONAL);
- for (unsigned i = 0; i < ar->count; ++i) {
- const knot_rrset_t *rr = knot_pkt_rr(ar, i);
- if (rr->type == type && knot_dname_is_equal(name, rr->owner)) {
- return kr_rrset_to_addr(addr, rr);
- }
- }
-
- return KNOT_ENOENT;
-}
+/* Iterator often walks through packet section, this is an abstraction. */
+typedef int (*rr_callback_t)(const knot_rrset_t *, struct kr_layer_param *);
-static int set_zone_cut(struct kr_rplan *rplan, knot_pkt_t *pkt, const knot_rrset_t *rr)
+/*! \brief Return minimized QNAME/QTYPE for current zone cut. */
+static const knot_dname_t *minimized_qname(struct kr_query *query, uint16_t *qtype)
{
- static const uint16_t type_list[] = { KNOT_RRTYPE_A, KNOT_RRTYPE_AAAA };
-
- /* Set zone cut to given name server. */
- const knot_dname_t *ns_name = knot_ns_name(&rr->rrs, 0);
- kr_set_zone_cut(&rplan->zone_cut, rr->owner, ns_name);
-
- /* Check if we can find a valid address in glue / cache */
- for (unsigned i = 0; i < sizeof(type_list)/sizeof(uint16_t); ++i) {
+ /* Minimization disabled. */
+ const knot_dname_t *qname = query->sname;
+ if (query->flags & QUERY_NO_MINIMIZE) {
+ return qname;
+ }
- /* Find address in the additionals (optional). */
- int ret = glue_ns_addr(pkt, &rplan->zone_cut.addr, ns_name, type_list[i]);
- if (ret == KNOT_EOK) {
- return KNOT_EOK;
- }
+ /* Minimize name to contain current zone cut + 1 label. */
+ int cut_labels = knot_dname_labels(query->zone_cut.name, NULL);
+ int qname_labels = knot_dname_labels(qname, NULL);
+ while(qname_labels > cut_labels + 1) {
+ qname = knot_wire_next_label(qname, NULL);
+ qname_labels -= 1;
}
- /* Query for address records (if not glue). */
- for (unsigned i = 0; i < sizeof(type_list)/sizeof(uint16_t); ++i) {
- (void) kr_rplan_push(rplan, rplan->zone_cut.ns, KNOT_CLASS_IN, type_list[i]);
+ /* Hide QTYPE if minimized. */
+ if (qname != query->sname) {
+ *qtype = KNOT_RRTYPE_NS;
}
- return KNOT_EOK;
+ return qname;
+}
+
+/*! \brief Answer is paired to query. */
+static bool is_paired_to_query(const knot_pkt_t *answer, struct kr_query *query)
+{
+ uint16_t qtype = query->stype;
+ const knot_dname_t *qname = minimized_qname(query, &qtype);
+
+ return query->id == knot_wire_get_id(answer->wire) &&
+ query->sclass == knot_pkt_qclass(answer) &&
+ qtype == knot_pkt_qtype(answer) &&
+ knot_dname_is_equal(qname, knot_pkt_qname(answer));
}
static void follow_cname_chain(const knot_dname_t **cname, const knot_rrset_t *rr,
}
}
+static int update_nsaddr(const knot_rrset_t *rr, struct kr_query *query)
+{
+ if (rr->type == KNOT_RRTYPE_A || rr->type == KNOT_RRTYPE_AAAA) {
+ if (knot_dname_is_equal(query->zone_cut.ns, rr->owner)) {
+ int ret = kr_rrset_to_addr(&query->zone_cut.addr, rr);
+ if (ret == KNOT_EOK) {
+ return KNOT_NS_PROC_DONE;
+ }
+ }
+ }
+
+ return KNOT_NS_PROC_MORE;
+}
+
+static int update_parent(const knot_rrset_t *rr, struct kr_layer_param *param)
+{
+ return update_nsaddr(rr, kr_rplan_last(param->rplan));
+}
+
/*! \brief Result updates the original query response. */
-static int update_answer(knot_pkt_t *answer, const knot_rrset_t *rr)
+static int update_answer(const knot_rrset_t *rr, struct kr_layer_param *param)
{
+ knot_pkt_t *answer = param->answer;
knot_rrset_t *rr_copy = knot_rrset_copy(rr, &answer->mm);
if (rr_copy == NULL) {
- return KNOT_ENOMEM;
+ return KNOT_NS_PROC_FAIL;
}
/* Write copied RR to the result packet. */
if (ret != KNOT_EOK) {
knot_rrset_free(&rr_copy, &answer->mm);
knot_wire_set_tc(answer->wire);
+ return KNOT_NS_PROC_DONE;
}
/* Free just the allocated container. */
mm_free(&answer->mm, rr_copy);
- return KNOT_EOK;
+
+ /* Update parent query as well. */
+ return update_parent(rr, param);
}
-static int update_zone_cut(knot_pkt_t *pkt, struct kr_rplan *rplan, const knot_rrset_t *rr)
+static int update_nameserver(const knot_rrset_t *rr, struct kr_layer_param *param)
{
- int ret = KNOT_EOK;
+ struct kr_query *query = kr_rplan_current(param->rplan);
+ const knot_dname_t *ns_name = knot_ns_name(&rr->rrs, 0);
- if (rr->type == KNOT_RRTYPE_A || rr->type == KNOT_RRTYPE_AAAA) {
- if (knot_dname_is_equal(rplan->zone_cut.ns, rr->owner)) {
- ret = kr_rrset_to_addr(&rplan->zone_cut.addr, rr);
- }
- } else if (rr->type == KNOT_RRTYPE_NS) {
- /* Authority MUST be at/below the authority of the nameserver, otherwise
- * possible cache injection attempt. */
- if (!knot_dname_in(rplan->zone_cut.name, rr->owner)) {
- DEBUG_MSG("NS in query outside of its authority => rejecting\n");
- return KNOT_EMALF;
- }
- /* Set the first nameserver address, rest will be cached. */
- if (!knot_dname_is_equal(rr->owner, rplan->zone_cut.name)) {
- ret = set_zone_cut(rplan, pkt, rr);
- } else {
- /* Zone cut not updated, referral loop. */
- ret = KNOT_EINVAL;
- }
+ /* Authority MUST be at/below the authority of the nameserver, otherwise
+ * possible cache injection attempt. */
+ if (!knot_dname_in(query->zone_cut.name, rr->owner)) {
+ DEBUG_MSG("NS in query outside of its authority => rejecting\n");
+ return KNOT_NS_PROC_FAIL;
}
- return ret;
+ /* Ignore already resolved zone cut. */
+ if (knot_dname_is_equal(rr->owner, query->zone_cut.name)) {
+ return KNOT_NS_PROC_MORE;
+ }
+
+ /* Set zone cut to given name server. */
+ kr_set_zone_cut(&query->zone_cut, rr->owner, ns_name);
+ return KNOT_NS_PROC_DONE;
}
-static int resolve_referral(knot_pkt_t *pkt, struct kr_layer_param *param)
+static int update_glue(const knot_rrset_t *rr, struct kr_layer_param *param)
{
+ return update_nsaddr(rr, kr_rplan_current(param->rplan));
+}
+
+static int process_authority(knot_pkt_t *pkt, struct kr_layer_param *param)
+{
+ int state = KNOT_NS_PROC_MORE;
+
+ /* Answer declares AA, can't be referral. */
+ if (knot_wire_get_aa(pkt->wire)) {
+ return state;
+ }
+
/* Update current zone cut from NS records. */
const knot_pktsection_t *ns = knot_pkt_section(pkt, KNOT_AUTHORITY);
for (unsigned i = 0; i < ns->count; ++i) {
if (rr->type != KNOT_RRTYPE_NS) {
continue;
}
- int ret = update_zone_cut(pkt, param->rplan, rr);
- if (ret == KNOT_EOK) {
- return KNOT_NS_PROC_DONE;
+
+ state = update_nameserver(rr, param);
+ if (state != KNOT_NS_PROC_MORE) {
+ break;
}
}
- /* Dead end, either bogus or loop referral. */
- struct kr_query *cur = kr_rplan_current(param->rplan);
- if (cur != NULL) {
- kr_rplan_pop(param->rplan, cur);
+ return state;
+}
+
+static int process_additional(knot_pkt_t *pkt, struct kr_layer_param *param)
+{
+ struct kr_query *query = kr_rplan_current(param->rplan);
+
+ /* Attempt to find glue for current nameserver. */
+ const knot_pktsection_t *ar = knot_pkt_section(pkt, KNOT_ADDITIONAL);
+ for (unsigned i = 0; i < ar->count; ++i) {
+ const knot_rrset_t *rr = knot_pkt_rr(ar, i);
+ int state = update_glue(rr, param);
+ if (state != KNOT_NS_PROC_MORE) {
+ return state;
+ }
}
- return KNOT_NS_PROC_FAIL;
+ /* Glue not found => resolve NS address. */
+ (void) kr_rplan_push(param->rplan, query->zone_cut.ns, KNOT_CLASS_IN, KNOT_RRTYPE_AAAA);
+ (void) kr_rplan_push(param->rplan, query->zone_cut.ns, KNOT_CLASS_IN, KNOT_RRTYPE_A);
+
+ return KNOT_NS_PROC_DONE;
}
-static int resolve_auth(knot_pkt_t *pkt, struct kr_layer_param *param)
+static int process_answer(knot_pkt_t *pkt, struct kr_layer_param *param)
{
- knot_pkt_t *answer = param->answer;
- struct kr_query *cur = kr_rplan_current(param->rplan);
- if (cur == NULL) {
- return KNOT_NS_PROC_FAIL;
- }
+ struct kr_query *query = kr_rplan_current(param->rplan);
- /* Authoritative response for minimized QNAME.
+ /* Response for minimized QNAME.
* NODATA => may be empty non-terminal, retry (found zone cut)
* NOERROR => found zone cut, retry
* NXDOMAIN => parent is zone cut, terminate
*/
- const knot_pktsection_t *an = knot_pkt_section(pkt, KNOT_ANSWER);
- bool is_minimized = (!knot_dname_is_equal(knot_pkt_qname(pkt), cur->sname));
+ bool is_minimized = (!knot_dname_is_equal(knot_pkt_qname(pkt), query->sname));
bool is_noerror = (knot_wire_get_rcode(pkt->wire) == KNOT_RCODE_NOERROR);
if (is_minimized && is_noerror) {
- cur->flags |= QUERY_NO_MINIMIZE;
+ query->flags |= QUERY_NO_MINIMIZE;
return KNOT_NS_PROC_DONE;
}
- /* Is relevant for original query? */
- bool update_orig_answer = (cur == kr_rplan_last(param->rplan));
-
- /* Process answer records. */
- const knot_dname_t *cname = cur->sname;
+ /* Does this answer update the final response? */
+ struct kr_query *parent_query = kr_rplan_last(param->rplan);
+ rr_callback_t callback = &update_parent;
+ if (query == parent_query) {
+ knot_wire_set_rcode(param->answer->wire, knot_wire_get_rcode(pkt->wire));
+ callback = &update_answer;
+ }
+
+ /* Process answer section records. */
+ const knot_dname_t *cname = query->sname;
+ const knot_pktsection_t *an = knot_pkt_section(pkt, KNOT_ANSWER);
for (unsigned i = 0; i < an->count; ++i) {
const knot_rrset_t *rr = knot_pkt_rr(an, i);
-
- /* Update original answer or current zone cut. */
- if (update_orig_answer && knot_pkt_qtype(pkt) == cur->stype) {
- if (update_answer(answer, rr) != KNOT_EOK) {
- return KNOT_NS_PROC_FAIL;
- }
- } else {
- if (update_zone_cut(pkt, param->rplan, rr) != KNOT_EOK) {
- return KNOT_NS_PROC_FAIL;
- }
+ int state = callback(rr, param);
+ if (state == KNOT_NS_PROC_FAIL) {
+ return state;
}
-
- /* Check canonical name. */
- follow_cname_chain(&cname, rr, cur);
+ follow_cname_chain(&cname, rr, query);
}
+ /* This is either declares AA or not, either way it resolves current query. */
+ kr_rplan_pop(param->rplan, query);
+
/* Follow canonical name as next SNAME. */
- if (cname != cur->sname) {
- struct kr_query *next = kr_rplan_push(param->rplan, cname,
- cur->sclass, cur->stype);
- if (next == NULL) {
- return KNOT_NS_PROC_FAIL;
- }
- }
-
- kr_rplan_pop(param->rplan, cur);
-
- /* Authoritative answer to original response => DONE. */
- if (update_orig_answer) {
- knot_wire_set_rcode(answer->wire, knot_wire_get_rcode(pkt->wire));
- } else {
- /* Side-lookup, update authority. */
- /* TODO: store zone-cut in query for side lookups */
- cur = kr_rplan_current(param->rplan);
- namedb_txn_t *txn = kr_rplan_txn_acquire(param->rplan, NAMEDB_RDONLY);
- kr_find_zone_cut(¶m->rplan->zone_cut, cur->sname, txn, cur->timestamp.tv_sec);
+ if (cname != query->sname) {
+ (void) kr_rplan_push(param->rplan, cname, query->sclass, query->stype);
}
return KNOT_NS_PROC_DONE;
return KNOT_NS_PROC_FAIL;
}
-/*! \brief Return minimized QNAME/QTYPE for current zone cut. */
-static const knot_dname_t *minimized_qname(struct kr_query *query, struct kr_zonecut *cut, uint16_t *qtype)
-{
- /* Minimization disabled. */
- const knot_dname_t *qname = query->sname;
- if (query->flags & QUERY_NO_MINIMIZE) {
- return qname;
- }
-
- /* Minimize name to contain current zone cut + 1 label. */
- int cut_labels = knot_dname_labels(cut->name, NULL);
- int qname_labels = knot_dname_labels(qname, NULL);
- while(qname_labels > cut_labels + 1) {
- qname = knot_wire_next_label(qname, NULL);
- qname_labels -= 1;
- }
-
- /* Hide QTYPE if minimized. */
- if (qname != query->sname) {
- *qtype = KNOT_RRTYPE_NS;
- }
-
- return qname;
-}
-
-/*! \brief Answer is paired to query. */
-static bool is_answer_to_query(const knot_pkt_t *answer, struct kr_rplan *rplan)
-{
- struct kr_query *expect = kr_rplan_current(rplan);
- if (expect == NULL) {
- return -1;
- }
-
- uint16_t qtype = expect->stype;
- const knot_dname_t *qname = minimized_qname(expect, &rplan->zone_cut, &qtype);
-
- return expect->id == knot_wire_get_id(answer->wire) &&
- expect->sclass == knot_pkt_qclass(answer) &&
- qtype == knot_pkt_qtype(answer) &&
- knot_dname_is_equal(qname, knot_pkt_qname(answer));
-}
-
/* State-less single resolution iteration step, not needed. */
static int reset(knot_layer_t *ctx) { return KNOT_NS_PROC_FULL; }
static int finish(knot_layer_t *ctx) { return KNOT_NS_PROC_NOOP; }
{
assert(pkt && ctx);
struct kr_layer_param *param = ctx->data;
- struct kr_query *cur = kr_rplan_current(param->rplan);
- if (cur == NULL || ctx->state == KNOT_NS_PROC_DONE) {
+ struct kr_query *query = kr_rplan_current(param->rplan);
+ if (query == NULL || ctx->state == KNOT_NS_PROC_DONE) {
return ctx->state;
}
/* Minimize QNAME (if possible). */
- struct kr_zonecut *zone_cut = ¶m->rplan->zone_cut;
- uint16_t qtype = cur->stype;
- const knot_dname_t *qname = minimized_qname(cur, zone_cut, &qtype);
+ uint16_t qtype = query->stype;
+ const knot_dname_t *qname = minimized_qname(query, &qtype);
/* Form a query for the authoritative. */
knot_pkt_clear(pkt);
- int ret = knot_pkt_put_question(pkt, qname, cur->sclass, qtype);
+ int ret = knot_pkt_put_question(pkt, qname, query->sclass, qtype);
if (ret != KNOT_EOK) {
return KNOT_NS_PROC_FAIL;
}
- cur->id = knot_random_uint16_t();
- knot_wire_set_id(pkt->wire, cur->id);
+ query->id = knot_random_uint16_t();
+ knot_wire_set_id(pkt->wire, query->id);
/* Declare EDNS0 support. */
knot_rrset_t opt_rr;
#ifndef NDEBUG
char name_str[KNOT_DNAME_MAXLEN], zonecut_str[KNOT_DNAME_MAXLEN], ns_str[KNOT_DNAME_MAXLEN], type_str[16];
- knot_dname_to_str(ns_str, zone_cut->ns, sizeof(ns_str));
- knot_dname_to_str(zonecut_str, zone_cut->name, sizeof(zonecut_str));
+ knot_dname_to_str(ns_str, query->zone_cut.ns, sizeof(ns_str));
+ knot_dname_to_str(zonecut_str, query->zone_cut.name, sizeof(zonecut_str));
knot_dname_to_str(name_str, qname, sizeof(name_str));
knot_rrtype_to_string(qtype, type_str, sizeof(type_str));
DEBUG_MSG("query '%s %s' zone cut '%s' nameserver '%s'\n", name_str, type_str, zonecut_str, ns_str);
{
assert(pkt && ctx);
struct kr_layer_param *param = ctx->data;
- int state = ctx->state;
+ struct kr_query *query = kr_rplan_current(param->rplan);
+ if (query == NULL) {
+ return ctx->state;
+ }
/* Check for packet processing errors first. */
if (pkt->parsed < pkt->size) {
return resolve_error(pkt, param, KNOT_EMALF);
- }
-
- /* Is this the droid we're looking for? */
- if (!is_answer_to_query(pkt, param->rplan)) {
+ } else if (!is_paired_to_query(pkt, query)) {
DEBUG_MSG("ignoring mismatching response\n");
return KNOT_NS_PROC_MORE;
- }
-
- /* Truncated response. */
- if (knot_wire_get_tc(pkt->wire)) {
+ } else if (knot_wire_get_tc(pkt->wire)) {
DEBUG_MSG("truncated response, failover to TCP\n");
struct kr_query *cur = kr_rplan_current(param->rplan);
if (cur) {
+ /* Fail if already on TCP. */
+ if (cur->flags & QUERY_TCP) {
+ return resolve_error(pkt, param, KNOT_EMALF);
+ }
cur->flags |= QUERY_TCP;
}
return KNOT_NS_PROC_DONE;
}
- /* TODO: classify response type
- * 1. authoritative, noerror/nxdomain
- * cname chain => update current sname
- * qname is current ns => update ns address
- * qname is tail => original query
- * 2. referral, update current zone cut
- */
-
/* Check response code. */
switch(knot_wire_get_rcode(pkt->wire)) {
case KNOT_RCODE_NOERROR:
return resolve_error(pkt, param, KNOT_ERROR);
}
- /* Is the answer authoritative? */
- if (knot_wire_get_aa(pkt->wire)) {
- state = resolve_auth(pkt, param);
- } else {
- state = resolve_referral(pkt, param);
+ /* Resolve authority to see if it's referral or authoritative. */
+ int state = KNOT_NS_PROC_MORE;
+ state = process_authority(pkt, param);
+ switch(state) {
+ case KNOT_NS_PROC_MORE: /* Not referral, process answer. */
+ state = process_answer(pkt, param);
+ break;
+ case KNOT_NS_PROC_DONE: /* Referral, try to find glue. */
+ state = process_additional(pkt, param);
+ break;
+ default:
+ break;
}
return state;
projects / thirdparty / knot-resolver.git / commitdiff
