wownero/external/unbound/iterator/iterator.c
Erik de Castro Lopo a85b5759f3 Upgrade unbound library
These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
2017-06-17 23:04:00 +10:00

3432 lines
116 KiB
C

/*
* iterator/iterator.c - iterative resolver DNS query response module
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains a module that performs recusive iterative DNS query
* processing.
*/
#include "config.h"
#include "iterator/iterator.h"
#include "iterator/iter_utils.h"
#include "iterator/iter_hints.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_donotq.h"
#include "iterator/iter_delegpt.h"
#include "iterator/iter_resptype.h"
#include "iterator/iter_scrub.h"
#include "iterator/iter_priv.h"
#include "validator/val_neg.h"
#include "services/cache/dns.h"
#include "services/cache/infra.h"
#include "util/module.h"
#include "util/netevent.h"
#include "util/net_help.h"
#include "util/regional.h"
#include "util/data/dname.h"
#include "util/data/msgencode.h"
#include "util/fptr_wlist.h"
#include "util/config_file.h"
#include "util/random.h"
#include "sldns/rrdef.h"
#include "sldns/wire2str.h"
#include "sldns/str2wire.h"
#include "sldns/parseutil.h"
#include "sldns/sbuffer.h"
int
iter_init(struct module_env* env, int id)
{
struct iter_env* iter_env = (struct iter_env*)calloc(1,
sizeof(struct iter_env));
if(!iter_env) {
log_err("malloc failure");
return 0;
}
env->modinfo[id] = (void*)iter_env;
if(!iter_apply_cfg(iter_env, env->cfg)) {
log_err("iterator: could not apply configuration settings.");
return 0;
}
return 1;
}
/** delete caps_whitelist element */
static void
caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d))
{
if(n) {
free(((struct name_tree_node*)n)->name);
free(n);
}
}
void
iter_deinit(struct module_env* env, int id)
{
struct iter_env* iter_env;
if(!env || !env->modinfo[id])
return;
iter_env = (struct iter_env*)env->modinfo[id];
free(iter_env->target_fetch_policy);
priv_delete(iter_env->priv);
donotq_delete(iter_env->donotq);
if(iter_env->caps_white) {
traverse_postorder(iter_env->caps_white, caps_free, NULL);
free(iter_env->caps_white);
}
free(iter_env);
env->modinfo[id] = NULL;
}
/** new query for iterator */
static int
iter_new(struct module_qstate* qstate, int id)
{
struct iter_qstate* iq = (struct iter_qstate*)regional_alloc(
qstate->region, sizeof(struct iter_qstate));
qstate->minfo[id] = iq;
if(!iq)
return 0;
memset(iq, 0, sizeof(*iq));
iq->state = INIT_REQUEST_STATE;
iq->final_state = FINISHED_STATE;
iq->an_prepend_list = NULL;
iq->an_prepend_last = NULL;
iq->ns_prepend_list = NULL;
iq->ns_prepend_last = NULL;
iq->dp = NULL;
iq->depth = 0;
iq->num_target_queries = 0;
iq->num_current_queries = 0;
iq->query_restart_count = 0;
iq->referral_count = 0;
iq->sent_count = 0;
iq->ratelimit_ok = 0;
iq->target_count = NULL;
iq->wait_priming_stub = 0;
iq->refetch_glue = 0;
iq->dnssec_expected = 0;
iq->dnssec_lame_query = 0;
iq->chase_flags = qstate->query_flags;
/* Start with the (current) qname. */
iq->qchase = qstate->qinfo;
outbound_list_init(&iq->outlist);
iq->minimise_count = 0;
iq->minimise_timeout_count = 0;
if (qstate->env->cfg->qname_minimisation)
iq->minimisation_state = INIT_MINIMISE_STATE;
else
iq->minimisation_state = DONOT_MINIMISE_STATE;
memset(&iq->qinfo_out, 0, sizeof(struct query_info));
return 1;
}
/**
* Transition to the next state. This can be used to advance a currently
* processing event. It cannot be used to reactivate a forEvent.
*
* @param iq: iterator query state
* @param nextstate The state to transition to.
* @return true. This is so this can be called as the return value for the
* actual process*State() methods. (Transitioning to the next state
* implies further processing).
*/
static int
next_state(struct iter_qstate* iq, enum iter_state nextstate)
{
/* If transitioning to a "response" state, make sure that there is a
* response */
if(iter_state_is_responsestate(nextstate)) {
if(iq->response == NULL) {
log_err("transitioning to response state sans "
"response.");
}
}
iq->state = nextstate;
return 1;
}
/**
* Transition an event to its final state. Final states always either return
* a result up the module chain, or reactivate a dependent event. Which
* final state to transition to is set in the module state for the event when
* it was created, and depends on the original purpose of the event.
*
* The response is stored in the qstate->buf buffer.
*
* @param iq: iterator query state
* @return false. This is so this method can be used as the return value for
* the processState methods. (Transitioning to the final state
*/
static int
final_state(struct iter_qstate* iq)
{
return next_state(iq, iq->final_state);
}
/**
* Callback routine to handle errors in parent query states
* @param qstate: query state that failed.
* @param id: module id.
* @param super: super state.
*/
static void
error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
{
struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
/* mark address as failed. */
struct delegpt_ns* dpns = NULL;
super_iq->num_target_queries--;
if(super_iq->dp)
dpns = delegpt_find_ns(super_iq->dp,
qstate->qinfo.qname, qstate->qinfo.qname_len);
if(!dpns) {
/* not interested */
verbose(VERB_ALGO, "subq error, but not interested");
log_query_info(VERB_ALGO, "superq", &super->qinfo);
if(super_iq->dp)
delegpt_log(VERB_ALGO, super_iq->dp);
log_assert(0);
return;
} else {
/* see if the failure did get (parent-lame) info */
if(!cache_fill_missing(super->env, super_iq->qchase.qclass,
super->region, super_iq->dp))
log_err("out of memory adding missing");
}
dpns->resolved = 1; /* mark as failed */
}
if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
/* prime failed to get delegation */
super_iq->dp = NULL;
}
/* evaluate targets again */
super_iq->state = QUERYTARGETS_STATE;
/* super becomes runnable, and will process this change */
}
/**
* Return an error to the client
* @param qstate: our query state
* @param id: module id
* @param rcode: error code (DNS errcode).
* @return: 0 for use by caller, to make notation easy, like:
* return error_response(..).
*/
static int
error_response(struct module_qstate* qstate, int id, int rcode)
{
verbose(VERB_QUERY, "return error response %s",
sldns_lookup_by_id(sldns_rcodes, rcode)?
sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
qstate->return_rcode = rcode;
qstate->return_msg = NULL;
qstate->ext_state[id] = module_finished;
return 0;
}
/**
* Return an error to the client and cache the error code in the
* message cache (so per qname, qtype, qclass).
* @param qstate: our query state
* @param id: module id
* @param rcode: error code (DNS errcode).
* @return: 0 for use by caller, to make notation easy, like:
* return error_response(..).
*/
static int
error_response_cache(struct module_qstate* qstate, int id, int rcode)
{
if(!qstate->no_cache_store) {
/* store in cache */
struct reply_info err;
if(qstate->prefetch_leeway > NORR_TTL) {
verbose(VERB_ALGO, "error response for prefetch in cache");
/* attempt to adjust the cache entry prefetch */
if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,
NORR_TTL, qstate->query_flags))
return error_response(qstate, id, rcode);
/* if that fails (not in cache), fall through to store err */
}
memset(&err, 0, sizeof(err));
err.flags = (uint16_t)(BIT_QR | BIT_RA);
FLAGS_SET_RCODE(err.flags, rcode);
err.qdcount = 1;
err.ttl = NORR_TTL;
err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
/* do not waste time trying to validate this servfail */
err.security = sec_status_indeterminate;
verbose(VERB_ALGO, "store error response in message cache");
iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL,
qstate->query_flags);
}
return error_response(qstate, id, rcode);
}
/** check if prepend item is duplicate item */
static int
prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
struct ub_packed_rrset_key* dup)
{
size_t i;
for(i=0; i<to; i++) {
if(sets[i]->rk.type == dup->rk.type &&
sets[i]->rk.rrset_class == dup->rk.rrset_class &&
sets[i]->rk.dname_len == dup->rk.dname_len &&
query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
== 0)
return 1;
}
return 0;
}
/** prepend the prepend list in the answer and authority section of dns_msg */
static int
iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
struct regional* region)
{
struct iter_prep_list* p;
struct ub_packed_rrset_key** sets;
size_t num_an = 0, num_ns = 0;;
for(p = iq->an_prepend_list; p; p = p->next)
num_an++;
for(p = iq->ns_prepend_list; p; p = p->next)
num_ns++;
if(num_an + num_ns == 0)
return 1;
verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX ||
msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */
sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) *
sizeof(struct ub_packed_rrset_key*));
if(!sets)
return 0;
/* ANSWER section */
num_an = 0;
for(p = iq->an_prepend_list; p; p = p->next) {
sets[num_an++] = p->rrset;
}
memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
sizeof(struct ub_packed_rrset_key*));
/* AUTH section */
num_ns = 0;
for(p = iq->ns_prepend_list; p; p = p->next) {
if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
num_ns, p->rrset) || prepend_is_duplicate(
msg->rep->rrsets+msg->rep->an_numrrsets,
msg->rep->ns_numrrsets, p->rrset))
continue;
sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
}
memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
msg->rep->rrsets + msg->rep->an_numrrsets,
(msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
sizeof(struct ub_packed_rrset_key*));
/* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
* this is what recursors should give. */
msg->rep->rrset_count += num_an + num_ns;
msg->rep->an_numrrsets += num_an;
msg->rep->ns_numrrsets += num_ns;
msg->rep->rrsets = sets;
return 1;
}
/**
* Find rrset in ANSWER prepend list.
* to avoid duplicate DNAMEs when a DNAME is traversed twice.
* @param iq: iterator query state.
* @param rrset: rrset to add.
* @return false if not found
*/
static int
iter_find_rrset_in_prepend_answer(struct iter_qstate* iq,
struct ub_packed_rrset_key* rrset)
{
struct iter_prep_list* p = iq->an_prepend_list;
while(p) {
if(ub_rrset_compare(p->rrset, rrset) == 0 &&
rrsetdata_equal((struct packed_rrset_data*)p->rrset
->entry.data, (struct packed_rrset_data*)rrset
->entry.data))
return 1;
p = p->next;
}
return 0;
}
/**
* Add rrset to ANSWER prepend list
* @param qstate: query state.
* @param iq: iterator query state.
* @param rrset: rrset to add.
* @return false on failure (malloc).
*/
static int
iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq,
struct ub_packed_rrset_key* rrset)
{
struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
qstate->region, sizeof(struct iter_prep_list));
if(!p)
return 0;
p->rrset = rrset;
p->next = NULL;
/* add at end */
if(iq->an_prepend_last)
iq->an_prepend_last->next = p;
else iq->an_prepend_list = p;
iq->an_prepend_last = p;
return 1;
}
/**
* Add rrset to AUTHORITY prepend list
* @param qstate: query state.
* @param iq: iterator query state.
* @param rrset: rrset to add.
* @return false on failure (malloc).
*/
static int
iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq,
struct ub_packed_rrset_key* rrset)
{
struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
qstate->region, sizeof(struct iter_prep_list));
if(!p)
return 0;
p->rrset = rrset;
p->next = NULL;
/* add at end */
if(iq->ns_prepend_last)
iq->ns_prepend_last->next = p;
else iq->ns_prepend_list = p;
iq->ns_prepend_last = p;
return 1;
}
/**
* Given a CNAME response (defined as a response containing a CNAME or DNAME
* that does not answer the request), process the response, modifying the
* state as necessary. This follows the CNAME/DNAME chain and returns the
* final query name.
*
* sets the new query name, after following the CNAME/DNAME chain.
* @param qstate: query state.
* @param iq: iterator query state.
* @param msg: the response.
* @param mname: returned target new query name.
* @param mname_len: length of mname.
* @return false on (malloc) error.
*/
static int
handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
{
size_t i;
/* Start with the (current) qname. */
*mname = iq->qchase.qname;
*mname_len = iq->qchase.qname_len;
/* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
* DNAMES. */
for(i=0; i<msg->rep->an_numrrsets; i++) {
struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
/* If there is a (relevant) DNAME, add it to the list.
* We always expect there to be CNAME that was generated
* by this DNAME following, so we don't process the DNAME
* directly. */
if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
dname_strict_subdomain_c(*mname, r->rk.dname) &&
!iter_find_rrset_in_prepend_answer(iq, r)) {
if(!iter_add_prepend_answer(qstate, iq, r))
return 0;
continue;
}
if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
query_dname_compare(*mname, r->rk.dname) == 0 &&
!iter_find_rrset_in_prepend_answer(iq, r)) {
/* Add this relevant CNAME rrset to the prepend list.*/
if(!iter_add_prepend_answer(qstate, iq, r))
return 0;
get_cname_target(r, mname, mname_len);
}
/* Other rrsets in the section are ignored. */
}
/* add authority rrsets to authority prepend, for wildcarded CNAMEs */
for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
msg->rep->ns_numrrsets; i++) {
struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
/* only add NSEC/NSEC3, as they may be needed for validation */
if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
if(!iter_add_prepend_auth(qstate, iq, r))
return 0;
}
}
return 1;
}
/** see if target name is caps-for-id whitelisted */
static int
is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq)
{
if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */
return name_tree_lookup(ie->caps_white, iq->qchase.qname,
iq->qchase.qname_len, dname_count_labels(iq->qchase.qname),
iq->qchase.qclass) != NULL;
}
/** create target count structure for this query */
static void
target_count_create(struct iter_qstate* iq)
{
if(!iq->target_count) {
iq->target_count = (int*)calloc(2, sizeof(int));
/* if calloc fails we simply do not track this number */
if(iq->target_count)
iq->target_count[0] = 1;
}
}
static void
target_count_increase(struct iter_qstate* iq, int num)
{
target_count_create(iq);
if(iq->target_count)
iq->target_count[1] += num;
}
/**
* Generate a subrequest.
* Generate a local request event. Local events are tied to this module, and
* have a corresponding (first tier) event that is waiting for this event to
* resolve to continue.
*
* @param qname The query name for this request.
* @param qnamelen length of qname
* @param qtype The query type for this request.
* @param qclass The query class for this request.
* @param qstate The event that is generating this event.
* @param id: module id.
* @param iq: The iterator state that is generating this event.
* @param initial_state The initial response state (normally this
* is QUERY_RESP_STATE, unless it is known that the request won't
* need iterative processing
* @param finalstate The final state for the response to this request.
* @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
* not need initialisation.
* @param v: if true, validation is done on the subquery.
* @return false on error (malloc).
*/
static int
generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
uint16_t qclass, struct module_qstate* qstate, int id,
struct iter_qstate* iq, enum iter_state initial_state,
enum iter_state finalstate, struct module_qstate** subq_ret, int v)
{
struct module_qstate* subq = NULL;
struct iter_qstate* subiq = NULL;
uint16_t qflags = 0; /* OPCODE QUERY, no flags */
struct query_info qinf;
int prime = (finalstate == PRIME_RESP_STATE)?1:0;
int valrec = 0;
qinf.qname = qname;
qinf.qname_len = qnamelen;
qinf.qtype = qtype;
qinf.qclass = qclass;
qinf.local_alias = NULL;
/* RD should be set only when sending the query back through the INIT
* state. */
if(initial_state == INIT_REQUEST_STATE)
qflags |= BIT_RD;
/* We set the CD flag so we can send this through the "head" of
* the resolution chain, which might have a validator. We are
* uninterested in validating things not on the direct resolution
* path. */
if(!v) {
qflags |= BIT_CD;
valrec = 1;
}
/* attach subquery, lookup existing or make a new one */
fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, valrec,
&subq)) {
return 0;
}
*subq_ret = subq;
if(subq) {
/* initialise the new subquery */
subq->curmod = id;
subq->ext_state[id] = module_state_initial;
subq->minfo[id] = regional_alloc(subq->region,
sizeof(struct iter_qstate));
if(!subq->minfo[id]) {
log_err("init subq: out of memory");
fptr_ok(fptr_whitelist_modenv_kill_sub(
qstate->env->kill_sub));
(*qstate->env->kill_sub)(subq);
return 0;
}
subiq = (struct iter_qstate*)subq->minfo[id];
memset(subiq, 0, sizeof(*subiq));
subiq->num_target_queries = 0;
target_count_create(iq);
subiq->target_count = iq->target_count;
if(iq->target_count)
iq->target_count[0] ++; /* extra reference */
subiq->num_current_queries = 0;
subiq->depth = iq->depth+1;
outbound_list_init(&subiq->outlist);
subiq->state = initial_state;
subiq->final_state = finalstate;
subiq->qchase = subq->qinfo;
subiq->chase_flags = subq->query_flags;
subiq->refetch_glue = 0;
if(qstate->env->cfg->qname_minimisation)
subiq->minimisation_state = INIT_MINIMISE_STATE;
else
subiq->minimisation_state = DONOT_MINIMISE_STATE;
memset(&subiq->qinfo_out, 0, sizeof(struct query_info));
}
return 1;
}
/**
* Generate and send a root priming request.
* @param qstate: the qtstate that triggered the need to prime.
* @param iq: iterator query state.
* @param id: module id.
* @param qclass: the class to prime.
* @return 0 on failure
*/
static int
prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
uint16_t qclass)
{
struct delegpt* dp;
struct module_qstate* subq;
verbose(VERB_DETAIL, "priming . %s NS",
sldns_lookup_by_id(sldns_rr_classes, (int)qclass)?
sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??");
dp = hints_lookup_root(qstate->env->hints, qclass);
if(!dp) {
verbose(VERB_ALGO, "Cannot prime due to lack of hints");
return 0;
}
/* Priming requests start at the QUERYTARGETS state, skipping
* the normal INIT state logic (which would cause an infloop). */
if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
&subq, 0)) {
verbose(VERB_ALGO, "could not prime root");
return 0;
}
if(subq) {
struct iter_qstate* subiq =
(struct iter_qstate*)subq->minfo[id];
/* Set the initial delegation point to the hint.
* copy dp, it is now part of the root prime query.
* dp was part of in the fixed hints structure. */
subiq->dp = delegpt_copy(dp, subq->region);
if(!subiq->dp) {
log_err("out of memory priming root, copydp");
fptr_ok(fptr_whitelist_modenv_kill_sub(
qstate->env->kill_sub));
(*qstate->env->kill_sub)(subq);
return 0;
}
/* there should not be any target queries. */
subiq->num_target_queries = 0;
subiq->dnssec_expected = iter_indicates_dnssec(
qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
}
/* this module stops, our submodule starts, and does the query. */
qstate->ext_state[id] = module_wait_subquery;
return 1;
}
/**
* Generate and process a stub priming request. This method tests for the
* need to prime a stub zone, so it is safe to call for every request.
*
* @param qstate: the qtstate that triggered the need to prime.
* @param iq: iterator query state.
* @param id: module id.
* @param qname: request name.
* @param qclass: request class.
* @return true if a priming subrequest was made, false if not. The will only
* issue a priming request if it detects an unprimed stub.
* Uses value of 2 to signal during stub-prime in root-prime situation
* that a noprime-stub is available and resolution can continue.
*/
static int
prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id,
uint8_t* qname, uint16_t qclass)
{
/* Lookup the stub hint. This will return null if the stub doesn't
* need to be re-primed. */
struct iter_hints_stub* stub;
struct delegpt* stub_dp;
struct module_qstate* subq;
if(!qname) return 0;
stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
/* The stub (if there is one) does not need priming. */
if(!stub)
return 0;
stub_dp = stub->dp;
/* is it a noprime stub (always use) */
if(stub->noprime) {
int r = 0;
if(iq->dp == NULL) r = 2;
/* copy the dp out of the fixed hints structure, so that
* it can be changed when servicing this query */
iq->dp = delegpt_copy(stub_dp, qstate->region);
if(!iq->dp) {
log_err("out of memory priming stub");
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return 1; /* return 1 to make module stop, with error */
}
log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
LDNS_RR_TYPE_NS, qclass);
return r;
}
/* Otherwise, we need to (re)prime the stub. */
log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name,
LDNS_RR_TYPE_NS, qclass);
/* Stub priming events start at the QUERYTARGETS state to avoid the
* redundant INIT state processing. */
if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) {
verbose(VERB_ALGO, "could not prime stub");
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return 1; /* return 1 to make module stop, with error */
}
if(subq) {
struct iter_qstate* subiq =
(struct iter_qstate*)subq->minfo[id];
/* Set the initial delegation point to the hint. */
/* make copy to avoid use of stub dp by different qs/threads */
subiq->dp = delegpt_copy(stub_dp, subq->region);
if(!subiq->dp) {
log_err("out of memory priming stub, copydp");
fptr_ok(fptr_whitelist_modenv_kill_sub(
qstate->env->kill_sub));
(*qstate->env->kill_sub)(subq);
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return 1; /* return 1 to make module stop, with error */
}
/* there should not be any target queries -- although there
* wouldn't be anyway, since stub hints never have
* missing targets. */
subiq->num_target_queries = 0;
subiq->wait_priming_stub = 1;
subiq->dnssec_expected = iter_indicates_dnssec(
qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
}
/* this module stops, our submodule starts, and does the query. */
qstate->ext_state[id] = module_wait_subquery;
return 1;
}
/**
* Generate A and AAAA checks for glue that is in-zone for the referral
* we just got to obtain authoritative information on the adresses.
*
* @param qstate: the qtstate that triggered the need to prime.
* @param iq: iterator query state.
* @param id: module id.
*/
static void
generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
struct module_qstate* subq;
size_t i;
struct reply_info* rep = iq->response->rep;
struct ub_packed_rrset_key* s;
log_assert(iq->dp);
if(iq->depth == ie->max_dependency_depth)
return;
/* walk through additional, and check if in-zone,
* only relevant A, AAAA are left after scrub anyway */
for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
s = rep->rrsets[i];
/* check *ALL* addresses that are transmitted in additional*/
/* is it an address ? */
if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
continue;
}
/* is this query the same as the A/AAAA check for it */
if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
query_dname_compare(qstate->qinfo.qname,
s->rk.dname)==0 &&
(qstate->query_flags&BIT_RD) &&
!(qstate->query_flags&BIT_CD))
continue;
/* generate subrequest for it */
log_nametypeclass(VERB_ALGO, "schedule addr fetch",
s->rk.dname, ntohs(s->rk.type),
ntohs(s->rk.rrset_class));
if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
ntohs(s->rk.type), ntohs(s->rk.rrset_class),
qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
verbose(VERB_ALGO, "could not generate addr check");
return;
}
/* ignore subq - not need for more init */
}
}
/**
* Generate a NS check request to obtain authoritative information
* on an NS rrset.
*
* @param qstate: the qtstate that triggered the need to prime.
* @param iq: iterator query state.
* @param id: module id.
*/
static void
generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
{
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
struct module_qstate* subq;
log_assert(iq->dp);
if(iq->depth == ie->max_dependency_depth)
return;
/* is this query the same as the nscheck? */
if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
(qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
/* spawn off A, AAAA queries for in-zone glue to check */
generate_a_aaaa_check(qstate, iq, id);
return;
}
log_nametypeclass(VERB_ALGO, "schedule ns fetch",
iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
verbose(VERB_ALGO, "could not generate ns check");
return;
}
if(subq) {
struct iter_qstate* subiq =
(struct iter_qstate*)subq->minfo[id];
/* make copy to avoid use of stub dp by different qs/threads */
/* refetch glue to start higher up the tree */
subiq->refetch_glue = 1;
subiq->dp = delegpt_copy(iq->dp, subq->region);
if(!subiq->dp) {
log_err("out of memory generating ns check, copydp");
fptr_ok(fptr_whitelist_modenv_kill_sub(
qstate->env->kill_sub));
(*qstate->env->kill_sub)(subq);
return;
}
}
}
/**
* Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
* just got in a referral (where we have dnssec_expected, thus have trust
* anchors above it). Note that right after calling this routine the
* iterator detached subqueries (because of following the referral), and thus
* the DNSKEY query becomes detached, its return stored in the cache for
* later lookup by the validator. This cache lookup by the validator avoids
* the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
* performed at about the same time the original query is sent to the domain,
* thus the two answers are likely to be returned at about the same time,
* saving a roundtrip from the validated lookup.
*
* @param qstate: the qtstate that triggered the need to prime.
* @param iq: iterator query state.
* @param id: module id.
*/
static void
generate_dnskey_prefetch(struct module_qstate* qstate,
struct iter_qstate* iq, int id)
{
struct module_qstate* subq;
log_assert(iq->dp);
/* is this query the same as the prefetch? */
if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
(qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
return;
}
/* if the DNSKEY is in the cache this lookup will stop quickly */
log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
/* we'll be slower, but it'll work */
verbose(VERB_ALGO, "could not generate dnskey prefetch");
return;
}
if(subq) {
struct iter_qstate* subiq =
(struct iter_qstate*)subq->minfo[id];
/* this qstate has the right delegation for the dnskey lookup*/
/* make copy to avoid use of stub dp by different qs/threads */
subiq->dp = delegpt_copy(iq->dp, subq->region);
/* if !subiq->dp, it'll start from the cache, no problem */
}
}
/**
* See if the query needs forwarding.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @return true if the request is forwarded, false if not.
* If returns true but, iq->dp is NULL then a malloc failure occurred.
*/
static int
forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
{
struct delegpt* dp;
uint8_t* delname = iq->qchase.qname;
size_t delnamelen = iq->qchase.qname_len;
if(iq->refetch_glue) {
delname = iq->dp->name;
delnamelen = iq->dp->namelen;
}
/* strip one label off of DS query to lookup higher for it */
if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
&& !dname_is_root(iq->qchase.qname))
dname_remove_label(&delname, &delnamelen);
dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
if(!dp)
return 0;
/* send recursion desired to forward addr */
iq->chase_flags |= BIT_RD;
iq->dp = delegpt_copy(dp, qstate->region);
/* iq->dp checked by caller */
verbose(VERB_ALGO, "forwarding request");
return 1;
}
/**
* Process the initial part of the request handling. This state roughly
* corresponds to resolver algorithms steps 1 (find answer in cache) and 2
* (find the best servers to ask).
*
* Note that all requests start here, and query restarts revisit this state.
*
* This state either generates: 1) a response, from cache or error, 2) a
* priming event, or 3) forwards the request to the next state (init2,
* generally).
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param ie: iterator shared global environment.
* @param id: module id.
* @return true if the event needs more request processing immediately,
* false if not.
*/
static int
processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id)
{
uint8_t* delname;
size_t delnamelen;
struct dns_msg* msg = NULL;
log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
/* check effort */
/* We enforce a maximum number of query restarts. This is primarily a
* cheap way to prevent CNAME loops. */
if(iq->query_restart_count > MAX_RESTART_COUNT) {
verbose(VERB_QUERY, "request has exceeded the maximum number"
" of query restarts with %d", iq->query_restart_count);
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* We enforce a maximum recursion/dependency depth -- in general,
* this is unnecessary for dependency loops (although it will
* catch those), but it provides a sensible limit to the amount
* of work required to answer a given query. */
verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
if(iq->depth > ie->max_dependency_depth) {
verbose(VERB_QUERY, "request has exceeded the maximum "
"dependency depth with depth of %d", iq->depth);
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* If the request is qclass=ANY, setup to generate each class */
if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
iq->qchase.qclass = 0;
return next_state(iq, COLLECT_CLASS_STATE);
}
/* Resolver Algorithm Step 1 -- Look for the answer in local data. */
/* This either results in a query restart (CNAME cache response), a
* terminating response (ANSWER), or a cache miss (null). */
if(qstate->blacklist) {
/* if cache, or anything else, was blacklisted then
* getting older results from cache is a bad idea, no cache */
verbose(VERB_ALGO, "cache blacklisted, going to the network");
msg = NULL;
} else if(!qstate->no_cache_lookup) {
msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
iq->qchase.qname_len, iq->qchase.qtype,
iq->qchase.qclass, qstate->query_flags,
qstate->region, qstate->env->scratch);
if(!msg && qstate->env->neg_cache) {
/* lookup in negative cache; may result in
* NOERROR/NODATA or NXDOMAIN answers that need validation */
msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
qstate->region, qstate->env->rrset_cache,
qstate->env->scratch_buffer,
*qstate->env->now, 1/*add SOA*/, NULL);
}
/* item taken from cache does not match our query name, thus
* security needs to be re-examined later */
if(msg && query_dname_compare(qstate->qinfo.qname,
iq->qchase.qname) != 0)
msg->rep->security = sec_status_unchecked;
}
if(msg) {
/* handle positive cache response */
enum response_type type = response_type_from_cache(msg,
&iq->qchase);
if(verbosity >= VERB_ALGO) {
log_dns_msg("msg from cache lookup", &msg->qinfo,
msg->rep);
verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
(int)msg->rep->ttl,
(int)msg->rep->prefetch_ttl);
}
if(type == RESPONSE_TYPE_CNAME) {
uint8_t* sname = 0;
size_t slen = 0;
verbose(VERB_ALGO, "returning CNAME response from "
"cache");
if(!handle_cname_response(qstate, iq, msg,
&sname, &slen))
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
iq->qchase.qname = sname;
iq->qchase.qname_len = slen;
/* This *is* a query restart, even if it is a cheap
* one. */
iq->dp = NULL;
iq->refetch_glue = 0;
iq->query_restart_count++;
iq->sent_count = 0;
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
if(qstate->env->cfg->qname_minimisation)
iq->minimisation_state = INIT_MINIMISE_STATE;
return next_state(iq, INIT_REQUEST_STATE);
}
/* if from cache, NULL, else insert 'cache IP' len=0 */
if(qstate->reply_origin)
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
/* it is an answer, response, to final state */
verbose(VERB_ALGO, "returning answer from cache.");
iq->response = msg;
return final_state(iq);
}
/* attempt to forward the request */
if(forward_request(qstate, iq))
{
if(!iq->dp) {
log_err("alloc failure for forward dp");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
iq->refetch_glue = 0;
iq->minimisation_state = DONOT_MINIMISE_STATE;
/* the request has been forwarded.
* forwarded requests need to be immediately sent to the
* next state, QUERYTARGETS. */
return next_state(iq, QUERYTARGETS_STATE);
}
/* Resolver Algorithm Step 2 -- find the "best" servers. */
/* first, adjust for DS queries. To avoid the grandparent problem,
* we just look for the closest set of server to the parent of qname.
* When re-fetching glue we also need to ask the parent.
*/
if(iq->refetch_glue) {
if(!iq->dp) {
log_err("internal or malloc fail: no dp for refetch");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
delname = iq->dp->name;
delnamelen = iq->dp->namelen;
} else {
delname = iq->qchase.qname;
delnamelen = iq->qchase.qname_len;
}
if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
(iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) {
/* remove first label from delname, root goes to hints,
* but only to fetch glue, not for qtype=DS. */
/* also when prefetching an NS record, fetch it again from
* its parent, just as if it expired, so that you do not
* get stuck on an older nameserver that gives old NSrecords */
if(dname_is_root(delname) && (iq->refetch_glue ||
(iq->qchase.qtype == LDNS_RR_TYPE_NS &&
qstate->prefetch_leeway)))
delname = NULL; /* go to root priming */
else dname_remove_label(&delname, &delnamelen);
}
/* delname is the name to lookup a delegation for. If NULL rootprime */
while(1) {
/* Lookup the delegation in the cache. If null, then the
* cache needs to be primed for the qclass. */
if(delname)
iq->dp = dns_cache_find_delegation(qstate->env, delname,
delnamelen, iq->qchase.qtype, iq->qchase.qclass,
qstate->region, &iq->deleg_msg,
*qstate->env->now+qstate->prefetch_leeway);
else iq->dp = NULL;
/* If the cache has returned nothing, then we have a
* root priming situation. */
if(iq->dp == NULL) {
/* if there is a stub, then no root prime needed */
int r = prime_stub(qstate, iq, id, delname,
iq->qchase.qclass);
if(r == 2)
break; /* got noprime-stub-zone, continue */
else if(r)
return 0; /* stub prime request made */
if(forwards_lookup_root(qstate->env->fwds,
iq->qchase.qclass)) {
/* forward zone root, no root prime needed */
/* fill in some dp - safety belt */
iq->dp = hints_lookup_root(qstate->env->hints,
iq->qchase.qclass);
if(!iq->dp) {
log_err("internal error: no hints dp");
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
}
iq->dp = delegpt_copy(iq->dp, qstate->region);
if(!iq->dp) {
log_err("out of memory in safety belt");
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
}
return next_state(iq, INIT_REQUEST_2_STATE);
}
/* Note that the result of this will set a new
* DelegationPoint based on the result of priming. */
if(!prime_root(qstate, iq, id, iq->qchase.qclass))
return error_response(qstate, id,
LDNS_RCODE_REFUSED);
/* priming creates and sends a subordinate query, with
* this query as the parent. So further processing for
* this event will stop until reactivated by the
* results of priming. */
return 0;
}
if(!iq->ratelimit_ok && qstate->prefetch_leeway)
iq->ratelimit_ok = 1; /* allow prefetches, this keeps
otherwise valid data in the cache */
if(!iq->ratelimit_ok && infra_ratelimit_exceeded(
qstate->env->infra_cache, iq->dp->name,
iq->dp->namelen, *qstate->env->now)) {
/* and increment the rate, so that the rate for time
* now will also exceed the rate, keeping cache fresh */
(void)infra_ratelimit_inc(qstate->env->infra_cache,
iq->dp->name, iq->dp->namelen,
*qstate->env->now);
/* see if we are passed through with slip factor */
if(qstate->env->cfg->ratelimit_factor != 0 &&
ub_random_max(qstate->env->rnd,
qstate->env->cfg->ratelimit_factor) == 1) {
iq->ratelimit_ok = 1;
log_nametypeclass(VERB_ALGO, "ratelimit allowed through for "
"delegation point", iq->dp->name,
LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
} else {
log_nametypeclass(VERB_ALGO, "ratelimit exceeded with "
"delegation point", iq->dp->name,
LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
}
/* see if this dp not useless.
* It is useless if:
* o all NS items are required glue.
* or the query is for NS item that is required glue.
* o no addresses are provided.
* o RD qflag is on.
* Instead, go up one level, and try to get even further
* If the root was useless, use safety belt information.
* Only check cache returns, because replies for servers
* could be useless but lead to loops (bumping into the
* same server reply) if useless-checked.
*/
if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
iq->dp)) {
if(dname_is_root(iq->dp->name)) {
/* use safety belt */
verbose(VERB_QUERY, "Cache has root NS but "
"no addresses. Fallback to the safety belt.");
iq->dp = hints_lookup_root(qstate->env->hints,
iq->qchase.qclass);
/* note deleg_msg is from previous lookup,
* but RD is on, so it is not used */
if(!iq->dp) {
log_err("internal error: no hints dp");
return error_response(qstate, id,
LDNS_RCODE_REFUSED);
}
iq->dp = delegpt_copy(iq->dp, qstate->region);
if(!iq->dp) {
log_err("out of memory in safety belt");
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
}
break;
} else {
verbose(VERB_ALGO,
"cache delegation was useless:");
delegpt_log(VERB_ALGO, iq->dp);
/* go up */
delname = iq->dp->name;
delnamelen = iq->dp->namelen;
dname_remove_label(&delname, &delnamelen);
}
} else break;
}
verbose(VERB_ALGO, "cache delegation returns delegpt");
delegpt_log(VERB_ALGO, iq->dp);
/* Otherwise, set the current delegation point and move on to the
* next state. */
return next_state(iq, INIT_REQUEST_2_STATE);
}
/**
* Process the second part of the initial request handling. This state
* basically exists so that queries that generate root priming events have
* the same init processing as ones that do not. Request events that reach
* this state must have a valid currentDelegationPoint set.
*
* This part is primarly handling stub zone priming. Events that reach this
* state must have a current delegation point.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true if the event needs more request processing immediately,
* false if not.
*/
static int
processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
uint8_t* delname;
size_t delnamelen;
log_query_info(VERB_QUERY, "resolving (init part 2): ",
&qstate->qinfo);
if(iq->refetch_glue) {
if(!iq->dp) {
log_err("internal or malloc fail: no dp for refetch");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
delname = iq->dp->name;
delnamelen = iq->dp->namelen;
} else {
delname = iq->qchase.qname;
delnamelen = iq->qchase.qname_len;
}
if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
if(!dname_is_root(delname))
dname_remove_label(&delname, &delnamelen);
iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
}
/* Check to see if we need to prime a stub zone. */
if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
/* A priming sub request was made */
return 0;
}
/* most events just get forwarded to the next state. */
return next_state(iq, INIT_REQUEST_3_STATE);
}
/**
* Process the third part of the initial request handling. This state exists
* as a separate state so that queries that generate stub priming events
* will get the tail end of the init process but not repeat the stub priming
* check.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true, advancing the event to the QUERYTARGETS_STATE.
*/
static int
processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
log_query_info(VERB_QUERY, "resolving (init part 3): ",
&qstate->qinfo);
/* if the cache reply dp equals a validation anchor or msg has DS,
* then DNSSEC RRSIGs are expected in the reply */
iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
iq->deleg_msg, iq->qchase.qclass);
/* If the RD flag wasn't set, then we just finish with the
* cached referral as the response. */
if(!(qstate->query_flags & BIT_RD) && iq->deleg_msg) {
iq->response = iq->deleg_msg;
if(verbosity >= VERB_ALGO && iq->response)
log_dns_msg("no RD requested, using delegation msg",
&iq->response->qinfo, iq->response->rep);
if(qstate->reply_origin)
sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
return final_state(iq);
}
/* After this point, unset the RD flag -- this query is going to
* be sent to an auth. server. */
iq->chase_flags &= ~BIT_RD;
/* if dnssec expected, fetch key for the trust-anchor or cached-DS */
if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
!(qstate->query_flags&BIT_CD)) {
generate_dnskey_prefetch(qstate, iq, id);
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
}
/* Jump to the next state. */
return next_state(iq, QUERYTARGETS_STATE);
}
/**
* Given a basic query, generate a parent-side "target" query.
* These are subordinate queries for missing delegation point target addresses,
* for which only the parent of the delegation provides correct IP addresses.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @param name: target qname.
* @param namelen: target qname length.
* @param qtype: target qtype (either A or AAAA).
* @param qclass: target qclass.
* @return true on success, false on failure.
*/
static int
generate_parentside_target_query(struct module_qstate* qstate,
struct iter_qstate* iq, int id, uint8_t* name, size_t namelen,
uint16_t qtype, uint16_t qclass)
{
struct module_qstate* subq;
if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
return 0;
if(subq) {
struct iter_qstate* subiq =
(struct iter_qstate*)subq->minfo[id];
/* blacklist the cache - we want to fetch parent stuff */
sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
subiq->query_for_pside_glue = 1;
if(dname_subdomain_c(name, iq->dp->name)) {
subiq->dp = delegpt_copy(iq->dp, subq->region);
subiq->dnssec_expected = iter_indicates_dnssec(
qstate->env, subiq->dp, NULL,
subq->qinfo.qclass);
subiq->refetch_glue = 1;
} else {
subiq->dp = dns_cache_find_delegation(qstate->env,
name, namelen, qtype, qclass, subq->region,
&subiq->deleg_msg,
*qstate->env->now+subq->prefetch_leeway);
/* if no dp, then it's from root, refetch unneeded */
if(subiq->dp) {
subiq->dnssec_expected = iter_indicates_dnssec(
qstate->env, subiq->dp, NULL,
subq->qinfo.qclass);
subiq->refetch_glue = 1;
}
}
}
log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
return 1;
}
/**
* Given a basic query, generate a "target" query. These are subordinate
* queries for missing delegation point target addresses.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @param name: target qname.
* @param namelen: target qname length.
* @param qtype: target qtype (either A or AAAA).
* @param qclass: target qclass.
* @return true on success, false on failure.
*/
static int
generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
{
struct module_qstate* subq;
if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
return 0;
log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
return 1;
}
/**
* Given an event at a certain state, generate zero or more target queries
* for it's current delegation point.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param ie: iterator shared global environment.
* @param id: module id.
* @param maxtargets: The maximum number of targets to query for.
* if it is negative, there is no maximum number of targets.
* @param num: returns the number of queries generated and processed,
* which may be zero if there were no missing targets.
* @return false on error.
*/
static int
query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id, int maxtargets, int* num)
{
int query_count = 0;
struct delegpt_ns* ns;
int missing;
int toget = 0;
if(iq->depth == ie->max_dependency_depth)
return 0;
if(iq->depth > 0 && iq->target_count &&
iq->target_count[1] > MAX_TARGET_COUNT) {
char s[LDNS_MAX_DOMAINLEN+1];
dname_str(qstate->qinfo.qname, s);
verbose(VERB_QUERY, "request %s has exceeded the maximum "
"number of glue fetches %d", s, iq->target_count[1]);
return 0;
}
iter_mark_cycle_targets(qstate, iq->dp);
missing = (int)delegpt_count_missing_targets(iq->dp);
log_assert(maxtargets != 0); /* that would not be useful */
/* Generate target requests. Basically, any missing targets
* are queried for here, regardless if it is necessary to do
* so to continue processing. */
if(maxtargets < 0 || maxtargets > missing)
toget = missing;
else toget = maxtargets;
if(toget == 0) {
*num = 0;
return 1;
}
/* select 'toget' items from the total of 'missing' items */
log_assert(toget <= missing);
/* loop over missing targets */
for(ns = iq->dp->nslist; ns; ns = ns->next) {
if(ns->resolved)
continue;
/* randomly select this item with probability toget/missing */
if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
/* do not select this one, next; select toget number
* of items from a list one less in size */
missing --;
continue;
}
if(ie->supports_ipv6 && !ns->got6) {
/* Send the AAAA request. */
if(!generate_target_query(qstate, iq, id,
ns->name, ns->namelen,
LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
*num = query_count;
if(query_count > 0)
qstate->ext_state[id] = module_wait_subquery;
return 0;
}
query_count++;
}
/* Send the A request. */
if(ie->supports_ipv4 && !ns->got4) {
if(!generate_target_query(qstate, iq, id,
ns->name, ns->namelen,
LDNS_RR_TYPE_A, iq->qchase.qclass)) {
*num = query_count;
if(query_count > 0)
qstate->ext_state[id] = module_wait_subquery;
return 0;
}
query_count++;
}
/* mark this target as in progress. */
ns->resolved = 1;
missing--;
toget--;
if(toget == 0)
break;
}
*num = query_count;
if(query_count > 0)
qstate->ext_state[id] = module_wait_subquery;
return 1;
}
/** see if last resort is possible - does config allow queries to parent */
static int
can_have_last_resort(struct module_env* env, struct delegpt* dp,
struct iter_qstate* iq)
{
struct delegpt* fwddp;
struct iter_hints_stub* stub;
/* do not process a last resort (the parent side) if a stub
* or forward is configured, because we do not want to go 'above'
* the configured servers */
if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*)
name_tree_find(&env->hints->tree, dp->name, dp->namelen,
dp->namelabs, iq->qchase.qclass)) &&
/* has_parent side is turned off for stub_first, where we
* are allowed to go to the parent */
stub->dp->has_parent_side_NS) {
verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL");
return 0;
}
if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) &&
/* has_parent_side is turned off for forward_first, where
* we are allowed to go to the parent */
fwddp->has_parent_side_NS) {
verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL");
return 0;
}
return 1;
}
/**
* Called by processQueryTargets when it would like extra targets to query
* but it seems to be out of options. At last resort some less appealing
* options are explored. If there are no more options, the result is SERVFAIL
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param ie: iterator shared global environment.
* @param id: module id.
* @return true if the event requires more request processing immediately,
* false if not.
*/
static int
processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id)
{
struct delegpt_ns* ns;
int query_count = 0;
verbose(VERB_ALGO, "No more query targets, attempting last resort");
log_assert(iq->dp);
if(!can_have_last_resort(qstate->env, iq->dp, iq)) {
/* fail -- no more targets, no more hope of targets, no hope
* of a response. */
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
struct delegpt* p = hints_lookup_root(qstate->env->hints,
iq->qchase.qclass);
if(p) {
struct delegpt_ns* ns;
struct delegpt_addr* a;
iq->chase_flags &= ~BIT_RD; /* go to authorities */
for(ns = p->nslist; ns; ns=ns->next) {
(void)delegpt_add_ns(iq->dp, qstate->region,
ns->name, ns->lame);
}
for(a = p->target_list; a; a=a->next_target) {
(void)delegpt_add_addr(iq->dp, qstate->region,
&a->addr, a->addrlen, a->bogus,
a->lame);
}
}
iq->dp->has_parent_side_NS = 1;
} else if(!iq->dp->has_parent_side_NS) {
if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
qstate->region, &qstate->qinfo)
|| !iq->dp->has_parent_side_NS) {
/* if: malloc failure in lookup go up to try */
/* if: no parent NS in cache - go up one level */
verbose(VERB_ALGO, "try to grab parent NS");
iq->store_parent_NS = iq->dp;
iq->chase_flags &= ~BIT_RD; /* go to authorities */
iq->deleg_msg = NULL;
iq->refetch_glue = 1;
iq->query_restart_count++;
iq->sent_count = 0;
if(qstate->env->cfg->qname_minimisation)
iq->minimisation_state = INIT_MINIMISE_STATE;
return next_state(iq, INIT_REQUEST_STATE);
}
}
/* see if that makes new names available */
if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
qstate->region, iq->dp))
log_err("out of memory in cache_fill_missing");
if(iq->dp->usable_list) {
verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
return next_state(iq, QUERYTARGETS_STATE);
}
/* try to fill out parent glue from cache */
if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
qstate->region, &qstate->qinfo)) {
/* got parent stuff from cache, see if we can continue */
verbose(VERB_ALGO, "try parent-side glue from cache");
return next_state(iq, QUERYTARGETS_STATE);
}
/* query for an extra name added by the parent-NS record */
if(delegpt_count_missing_targets(iq->dp) > 0) {
int qs = 0;
verbose(VERB_ALGO, "try parent-side target name");
if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
iq->num_target_queries += qs;
target_count_increase(iq, qs);
if(qs != 0) {
qstate->ext_state[id] = module_wait_subquery;
return 0; /* and wait for them */
}
}
if(iq->depth == ie->max_dependency_depth) {
verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
if(iq->depth > 0 && iq->target_count &&
iq->target_count[1] > MAX_TARGET_COUNT) {
char s[LDNS_MAX_DOMAINLEN+1];
dname_str(qstate->qinfo.qname, s);
verbose(VERB_QUERY, "request %s has exceeded the maximum "
"number of glue fetches %d", s, iq->target_count[1]);
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* mark cycle targets for parent-side lookups */
iter_mark_pside_cycle_targets(qstate, iq->dp);
/* see if we can issue queries to get nameserver addresses */
/* this lookup is not randomized, but sequential. */
for(ns = iq->dp->nslist; ns; ns = ns->next) {
/* query for parent-side A and AAAA for nameservers */
if(ie->supports_ipv6 && !ns->done_pside6) {
/* Send the AAAA request. */
if(!generate_parentside_target_query(qstate, iq, id,
ns->name, ns->namelen,
LDNS_RR_TYPE_AAAA, iq->qchase.qclass))
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
ns->done_pside6 = 1;
query_count++;
}
if(ie->supports_ipv4 && !ns->done_pside4) {
/* Send the A request. */
if(!generate_parentside_target_query(qstate, iq, id,
ns->name, ns->namelen,
LDNS_RR_TYPE_A, iq->qchase.qclass))
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
ns->done_pside4 = 1;
query_count++;
}
if(query_count != 0) { /* suspend to await results */
verbose(VERB_ALGO, "try parent-side glue lookup");
iq->num_target_queries += query_count;
target_count_increase(iq, query_count);
qstate->ext_state[id] = module_wait_subquery;
return 0;
}
}
/* if this was a parent-side glue query itself, then store that
* failure in cache. */
if(!qstate->no_cache_store && iq->query_for_pside_glue
&& !iq->pside_glue)
iter_store_parentside_neg(qstate->env, &qstate->qinfo,
iq->deleg_msg?iq->deleg_msg->rep:
(iq->response?iq->response->rep:NULL));
verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
/* fail -- no more targets, no more hope of targets, no hope
* of a response. */
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
/**
* Try to find the NS record set that will resolve a qtype DS query. Due
* to grandparent/grandchild reasons we did not get a proper lookup right
* away. We need to create type NS queries until we get the right parent
* for this lookup. We remove labels from the query to find the right point.
* If we end up at the old dp name, then there is no solution.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true if the event requires more immediate processing, false if
* not. This is generally only true when forwarding the request to
* the final state (i.e., on answer).
*/
static int
processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
{
struct module_qstate* subq = NULL;
verbose(VERB_ALGO, "processDSNSFind");
if(!iq->dsns_point) {
/* initialize */
iq->dsns_point = iq->qchase.qname;
iq->dsns_point_len = iq->qchase.qname_len;
}
/* robustcheck for internal error: we are not underneath the dp */
if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* go up one (more) step, until we hit the dp, if so, end */
dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
/* there was no inbetween nameserver, use the old delegation
* point again. And this time, because dsns_point is nonNULL
* we are going to accept the (bad) result */
iq->state = QUERYTARGETS_STATE;
return 1;
}
iq->state = DSNS_FIND_STATE;
/* spawn NS lookup (validation not needed, this is for DS lookup) */
log_nametypeclass(VERB_ALGO, "fetch nameservers",
iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
return 0;
}
/**
* This is the request event state where the request will be sent to one of
* its current query targets. This state also handles issuing target lookup
* queries for missing target IP addresses. Queries typically iterate on
* this state, both when they are just trying different targets for a given
* delegation point, and when they change delegation points. This state
* roughly corresponds to RFC 1034 algorithm steps 3 and 4.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param ie: iterator shared global environment.
* @param id: module id.
* @return true if the event requires more request processing immediately,
* false if not. This state only returns true when it is generating
* a SERVFAIL response because the query has hit a dead end.
*/
static int
processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id)
{
int tf_policy;
struct delegpt_addr* target;
struct outbound_entry* outq;
/* NOTE: a request will encounter this state for each target it
* needs to send a query to. That is, at least one per referral,
* more if some targets timeout or return throwaway answers. */
log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
"currentqueries %d sentcount %d", iq->num_target_queries,
iq->num_current_queries, iq->sent_count);
/* Make sure that we haven't run away */
/* FIXME: is this check even necessary? */
if(iq->referral_count > MAX_REFERRAL_COUNT) {
verbose(VERB_QUERY, "request has exceeded the maximum "
"number of referrrals with %d", iq->referral_count);
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
if(iq->sent_count > MAX_SENT_COUNT) {
verbose(VERB_QUERY, "request has exceeded the maximum "
"number of sends with %d", iq->sent_count);
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* Make sure we have a delegation point, otherwise priming failed
* or another failure occurred */
if(!iq->dp) {
verbose(VERB_QUERY, "Failed to get a delegation, giving up");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
if(!ie->supports_ipv6)
delegpt_no_ipv6(iq->dp);
if(!ie->supports_ipv4)
delegpt_no_ipv4(iq->dp);
delegpt_log(VERB_ALGO, iq->dp);
if(iq->num_current_queries>0) {
/* already busy answering a query, this restart is because
* more delegpt addrs became available, wait for existing
* query. */
verbose(VERB_ALGO, "woke up, but wait for outstanding query");
qstate->ext_state[id] = module_wait_reply;
return 0;
}
tf_policy = 0;
/* < not <=, because although the array is large enough for <=, the
* generated query will immediately be discarded due to depth and
* that servfail is cached, which is not good as opportunism goes. */
if(iq->depth < ie->max_dependency_depth
&& iq->sent_count < TARGET_FETCH_STOP) {
tf_policy = ie->target_fetch_policy[iq->depth];
}
/* if in 0x20 fallback get as many targets as possible */
if(iq->caps_fallback) {
int extra = 0;
size_t naddr, nres, navail;
if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
iq->num_target_queries += extra;
target_count_increase(iq, extra);
if(iq->num_target_queries > 0) {
/* wait to get all targets, we want to try em */
verbose(VERB_ALGO, "wait for all targets for fallback");
qstate->ext_state[id] = module_wait_reply;
return 0;
}
/* did we do enough fallback queries already? */
delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
/* the current caps_server is the number of fallbacks sent.
* the original query is one that matched too, so we have
* caps_server+1 number of matching queries now */
if(iq->caps_server+1 >= naddr*3 ||
iq->caps_server*2+2 >= MAX_SENT_COUNT) {
/* *2 on sentcount check because ipv6 may fail */
/* we're done, process the response */
verbose(VERB_ALGO, "0x20 fallback had %d responses "
"match for %d wanted, done.",
(int)iq->caps_server+1, (int)naddr*3);
iq->response = iq->caps_response;
iq->caps_fallback = 0;
iter_dec_attempts(iq->dp, 3); /* space for fallback */
iq->num_current_queries++; /* RespState decrements it*/
iq->referral_count++; /* make sure we don't loop */
iq->sent_count = 0;
iq->state = QUERY_RESP_STATE;
return 1;
}
verbose(VERB_ALGO, "0x20 fallback number %d",
(int)iq->caps_server);
/* if there is a policy to fetch missing targets
* opportunistically, do it. we rely on the fact that once a
* query (or queries) for a missing name have been issued,
* they will not show up again. */
} else if(tf_policy != 0) {
int extra = 0;
verbose(VERB_ALGO, "attempt to get extra %d targets",
tf_policy);
(void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
/* errors ignored, these targets are not strictly necessary for
* this result, we do not have to reply with SERVFAIL */
iq->num_target_queries += extra;
target_count_increase(iq, extra);
}
/* Add the current set of unused targets to our queue. */
delegpt_add_unused_targets(iq->dp);
/* Select the next usable target, filtering out unsuitable targets. */
target = iter_server_selection(ie, qstate->env, iq->dp,
iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
&iq->dnssec_lame_query, &iq->chase_to_rd,
iq->num_target_queries, qstate->blacklist);
/* If no usable target was selected... */
if(!target) {
/* Here we distinguish between three states: generate a new
* target query, just wait, or quit (with a SERVFAIL).
* We have the following information: number of active
* target queries, number of active current queries,
* the presence of missing targets at this delegation
* point, and the given query target policy. */
/* Check for the wait condition. If this is true, then
* an action must be taken. */
if(iq->num_target_queries==0 && iq->num_current_queries==0) {
/* If there is nothing to wait for, then we need
* to distinguish between generating (a) new target
* query, or failing. */
if(delegpt_count_missing_targets(iq->dp) > 0) {
int qs = 0;
verbose(VERB_ALGO, "querying for next "
"missing target");
if(!query_for_targets(qstate, iq, ie, id,
1, &qs)) {
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
}
if(qs == 0 &&
delegpt_count_missing_targets(iq->dp) == 0){
/* it looked like there were missing
* targets, but they did not turn up.
* Try the bad choices again (if any),
* when we get back here missing==0,
* so this is not a loop. */
return 1;
}
iq->num_target_queries += qs;
target_count_increase(iq, qs);
}
/* Since a target query might have been made, we
* need to check again. */
if(iq->num_target_queries == 0) {
/* if in capsforid fallback, instead of last
* resort, we agree with the current reply
* we have (if any) (our count of addrs bad)*/
if(iq->caps_fallback && iq->caps_reply) {
/* we're done, process the response */
verbose(VERB_ALGO, "0x20 fallback had %d responses, "
"but no more servers except "
"last resort, done.",
(int)iq->caps_server+1);
iq->response = iq->caps_response;
iq->caps_fallback = 0;
iter_dec_attempts(iq->dp, 3); /* space for fallback */
iq->num_current_queries++; /* RespState decrements it*/
iq->referral_count++; /* make sure we don't loop */
iq->sent_count = 0;
iq->state = QUERY_RESP_STATE;
return 1;
}
return processLastResort(qstate, iq, ie, id);
}
}
/* otherwise, we have no current targets, so submerge
* until one of the target or direct queries return. */
if(iq->num_target_queries>0 && iq->num_current_queries>0) {
verbose(VERB_ALGO, "no current targets -- waiting "
"for %d targets to resolve or %d outstanding"
" queries to respond", iq->num_target_queries,
iq->num_current_queries);
qstate->ext_state[id] = module_wait_reply;
} else if(iq->num_target_queries>0) {
verbose(VERB_ALGO, "no current targets -- waiting "
"for %d targets to resolve.",
iq->num_target_queries);
qstate->ext_state[id] = module_wait_subquery;
} else {
verbose(VERB_ALGO, "no current targets -- waiting "
"for %d outstanding queries to respond.",
iq->num_current_queries);
qstate->ext_state[id] = module_wait_reply;
}
return 0;
}
/* if not forwarding, check ratelimits per delegationpoint name */
if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
if(!infra_ratelimit_inc(qstate->env->infra_cache, iq->dp->name,
iq->dp->namelen, *qstate->env->now)) {
verbose(VERB_ALGO, "query exceeded ratelimits");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
}
if(iq->minimisation_state == INIT_MINIMISE_STATE) {
/* (Re)set qinfo_out to (new) delegation point, except when
* qinfo_out is already a subdomain of dp. This happens when
* increasing by more than one label at once (QNAMEs with more
* than MAX_MINIMISE_COUNT labels). */
if(!(iq->qinfo_out.qname_len
&& dname_subdomain_c(iq->qchase.qname,
iq->qinfo_out.qname)
&& dname_subdomain_c(iq->qinfo_out.qname,
iq->dp->name))) {
iq->qinfo_out.qname = iq->dp->name;
iq->qinfo_out.qname_len = iq->dp->namelen;
iq->qinfo_out.qtype = LDNS_RR_TYPE_A;
iq->qinfo_out.qclass = iq->qchase.qclass;
iq->qinfo_out.local_alias = NULL;
iq->minimise_count = 0;
}
iq->minimisation_state = MINIMISE_STATE;
}
if(iq->minimisation_state == MINIMISE_STATE) {
int qchaselabs = dname_count_labels(iq->qchase.qname);
int labdiff = qchaselabs -
dname_count_labels(iq->qinfo_out.qname);
iq->qinfo_out.qname = iq->qchase.qname;
iq->qinfo_out.qname_len = iq->qchase.qname_len;
iq->minimise_count++;
iq->minimise_timeout_count = 0;
iter_dec_attempts(iq->dp, 1);
/* Limit number of iterations for QNAMEs with more
* than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB
* labels of QNAME always individually.
*/
if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 &&
iq->minimise_count > MINIMISE_ONE_LAB) {
if(iq->minimise_count < MAX_MINIMISE_COUNT) {
int multilabs = qchaselabs - 1 -
MINIMISE_ONE_LAB;
int extralabs = multilabs /
MINIMISE_MULTIPLE_LABS;
if (MAX_MINIMISE_COUNT - iq->minimise_count >=
multilabs % MINIMISE_MULTIPLE_LABS)
/* Default behaviour is to add 1 label
* every iteration. Therefore, decrement
* the extralabs by 1 */
extralabs--;
if (extralabs < labdiff)
labdiff -= extralabs;
else
labdiff = 1;
}
/* Last minimised iteration, send all labels with
* QTYPE=NS */
else
labdiff = 1;
}
if(labdiff > 1) {
verbose(VERB_QUERY, "removing %d labels", labdiff-1);
dname_remove_labels(&iq->qinfo_out.qname,
&iq->qinfo_out.qname_len,
labdiff-1);
}
if(labdiff < 1 || (labdiff < 2
&& (iq->qchase.qtype == LDNS_RR_TYPE_DS
|| iq->qchase.qtype == LDNS_RR_TYPE_A)))
/* Stop minimising this query, resolve "as usual" */
iq->minimisation_state = DONOT_MINIMISE_STATE;
else if(!qstate->no_cache_lookup) {
struct dns_msg* msg = dns_cache_lookup(qstate->env,
iq->qinfo_out.qname, iq->qinfo_out.qname_len,
iq->qinfo_out.qtype, iq->qinfo_out.qclass,
qstate->query_flags, qstate->region,
qstate->env->scratch);
if(msg && msg->rep->an_numrrsets == 0
&& FLAGS_GET_RCODE(msg->rep->flags) ==
LDNS_RCODE_NOERROR)
/* no need to send query if it is already
* cached as NOERROR/NODATA */
return 1;
}
}
if(iq->minimisation_state == SKIP_MINIMISE_STATE) {
iq->minimise_timeout_count++;
if(iq->minimise_timeout_count < MAX_MINIMISE_TIMEOUT_COUNT)
/* Do not increment qname, continue incrementing next
* iteration */
iq->minimisation_state = MINIMISE_STATE;
else if(!qstate->env->cfg->qname_minimisation_strict)
/* Too many time-outs detected for this QNAME and QTYPE.
* We give up, disable QNAME minimisation. */
iq->minimisation_state = DONOT_MINIMISE_STATE;
}
if(iq->minimisation_state == DONOT_MINIMISE_STATE)
iq->qinfo_out = iq->qchase;
/* We have a valid target. */
if(verbosity >= VERB_QUERY) {
log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out);
log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
&target->addr, target->addrlen);
verbose(VERB_ALGO, "dnssec status: %s%s",
iq->dnssec_expected?"expected": "not expected",
iq->dnssec_lame_query?" but lame_query anyway": "");
}
fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
outq = (*qstate->env->send_query)(&iq->qinfo_out,
iq->chase_flags | (iq->chase_to_rd?BIT_RD:0),
/* unset CD if to forwarder(RD set) and not dnssec retry
* (blacklist nonempty) and no trust-anchors are configured
* above the qname or on the first attempt when dnssec is on */
EDNS_DO| ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&&
!qstate->blacklist&&(!iter_indicates_dnssec_fwd(qstate->env,
&iq->qinfo_out)||target->attempts==1)?0:BIT_CD),
iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted(
ie, iq), &target->addr, target->addrlen,
iq->dp->name, iq->dp->namelen,
(iq->dp->ssl_upstream || qstate->env->cfg->ssl_upstream), qstate);
if(!outq) {
log_addr(VERB_DETAIL, "error sending query to auth server",
&target->addr, target->addrlen);
if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok)
infra_ratelimit_dec(qstate->env->infra_cache, iq->dp->name,
iq->dp->namelen, *qstate->env->now);
return next_state(iq, QUERYTARGETS_STATE);
}
outbound_list_insert(&iq->outlist, outq);
iq->num_current_queries++;
iq->sent_count++;
qstate->ext_state[id] = module_wait_reply;
return 0;
}
/** find NS rrset in given list */
static struct ub_packed_rrset_key*
find_NS(struct reply_info* rep, size_t from, size_t to)
{
size_t i;
for(i=from; i<to; i++) {
if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
return rep->rrsets[i];
}
return NULL;
}
/**
* Process the query response. All queries end up at this state first. This
* process generally consists of analyzing the response and routing the
* event to the next state (either bouncing it back to a request state, or
* terminating the processing for this event).
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true if the event requires more immediate processing, false if
* not. This is generally only true when forwarding the request to
* the final state (i.e., on answer).
*/
static int
processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
int dnsseclame = 0;
enum response_type type;
iq->num_current_queries--;
if(!inplace_cb_query_response_call(qstate->env, qstate, iq->response))
log_err("unable to call query_response callback");
if(iq->response == NULL) {
/* Don't increment qname when QNAME minimisation is enabled */
if(qstate->env->cfg->qname_minimisation)
iq->minimisation_state = SKIP_MINIMISE_STATE;
iq->chase_to_rd = 0;
iq->dnssec_lame_query = 0;
verbose(VERB_ALGO, "query response was timeout");
return next_state(iq, QUERYTARGETS_STATE);
}
type = response_type_from_server(
(int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
iq->response, &iq->qchase, iq->dp);
iq->chase_to_rd = 0;
if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) {
/* When forwarding (RD bit is set), we handle referrals
* differently. No queries should be sent elsewhere */
type = RESPONSE_TYPE_ANSWER;
}
if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected
&& !iq->dnssec_lame_query &&
!(iq->chase_flags&BIT_RD)
&& iq->sent_count < DNSSEC_LAME_DETECT_COUNT
&& type != RESPONSE_TYPE_LAME
&& type != RESPONSE_TYPE_REC_LAME
&& type != RESPONSE_TYPE_THROWAWAY
&& type != RESPONSE_TYPE_UNTYPED) {
/* a possible answer, see if it is missing DNSSEC */
/* but not when forwarding, so we dont mark fwder lame */
if(!iter_msg_has_dnssec(iq->response)) {
/* Mark this address as dnsseclame in this dp,
* because that will make serverselection disprefer
* it, but also, once it is the only final option,
* use dnssec-lame-bypass if it needs to query there.*/
if(qstate->reply) {
struct delegpt_addr* a = delegpt_find_addr(
iq->dp, &qstate->reply->addr,
qstate->reply->addrlen);
if(a) a->dnsseclame = 1;
}
/* test the answer is from the zone we expected,
* otherwise, (due to parent,child on same server), we
* might mark the server,zone lame inappropriately */
if(!iter_msg_from_zone(iq->response, iq->dp, type,
iq->qchase.qclass))
qstate->reply = NULL;
type = RESPONSE_TYPE_LAME;
dnsseclame = 1;
}
} else iq->dnssec_lame_query = 0;
/* see if referral brings us close to the target */
if(type == RESPONSE_TYPE_REFERRAL) {
struct ub_packed_rrset_key* ns = find_NS(
iq->response->rep, iq->response->rep->an_numrrsets,
iq->response->rep->an_numrrsets
+ iq->response->rep->ns_numrrsets);
if(!ns) ns = find_NS(iq->response->rep, 0,
iq->response->rep->an_numrrsets);
if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
|| !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
verbose(VERB_ALGO, "bad referral, throwaway");
type = RESPONSE_TYPE_THROWAWAY;
} else
iter_scrub_ds(iq->response, ns, iq->dp->name);
} else iter_scrub_ds(iq->response, NULL, NULL);
if(type == RESPONSE_TYPE_THROWAWAY &&
FLAGS_GET_RCODE(iq->response->rep->flags) == LDNS_RCODE_YXDOMAIN) {
/* YXDOMAIN is a permanent error, no need to retry */
type = RESPONSE_TYPE_ANSWER;
}
if(type == RESPONSE_TYPE_CNAME && iq->response->rep->an_numrrsets >= 1
&& ntohs(iq->response->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DNAME) {
uint8_t* sname = NULL;
size_t snamelen = 0;
get_cname_target(iq->response->rep->rrsets[0], &sname,
&snamelen);
if(snamelen && dname_subdomain_c(sname, iq->response->rep->rrsets[0]->rk.dname)) {
/* DNAME to a subdomain loop; do not recurse */
type = RESPONSE_TYPE_ANSWER;
}
}
/* handle each of the type cases */
if(type == RESPONSE_TYPE_ANSWER) {
/* ANSWER type responses terminate the query algorithm,
* so they sent on their */
if(verbosity >= VERB_DETAIL) {
verbose(VERB_DETAIL, "query response was %s",
FLAGS_GET_RCODE(iq->response->rep->flags)
==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
(iq->response->rep->an_numrrsets?"ANSWER":
"nodata ANSWER"));
}
/* if qtype is DS, check we have the right level of answer,
* like grandchild answer but we need the middle, reject it */
if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
&& !(iq->chase_flags&BIT_RD)
&& iter_ds_toolow(iq->response, iq->dp)
&& iter_dp_cangodown(&iq->qchase, iq->dp)) {
/* close down outstanding requests to be discarded */
outbound_list_clear(&iq->outlist);
iq->num_current_queries = 0;
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
iq->num_target_queries = 0;
return processDSNSFind(qstate, iq, id);
}
if(!qstate->no_cache_store)
iter_dns_store(qstate->env, &iq->response->qinfo,
iq->response->rep, 0, qstate->prefetch_leeway,
iq->dp&&iq->dp->has_parent_side_NS,
qstate->region, qstate->query_flags);
/* close down outstanding requests to be discarded */
outbound_list_clear(&iq->outlist);
iq->num_current_queries = 0;
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
iq->num_target_queries = 0;
if(qstate->reply)
sock_list_insert(&qstate->reply_origin,
&qstate->reply->addr, qstate->reply->addrlen,
qstate->region);
if(iq->minimisation_state != DONOT_MINIMISE_STATE) {
if(FLAGS_GET_RCODE(iq->response->rep->flags) !=
LDNS_RCODE_NOERROR) {
if(qstate->env->cfg->qname_minimisation_strict)
return final_state(iq);
/* Best effort qname-minimisation.
* Stop minimising and send full query when
* RCODE is not NOERROR. */
iq->minimisation_state = DONOT_MINIMISE_STATE;
}
if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
LDNS_RCODE_NXDOMAIN) {
/* Stop resolving when NXDOMAIN is DNSSEC
* signed. Based on assumption that namservers
* serving signed zones do not return NXDOMAIN
* for empty-non-terminals. */
if(iq->dnssec_expected)
return final_state(iq);
/* Make subrequest to validate intermediate
* NXDOMAIN if harden-below-nxdomain is
* enabled. */
if(qstate->env->cfg->harden_below_nxdomain) {
struct module_qstate* subq = NULL;
log_query_info(VERB_QUERY,
"schedule NXDOMAIN validation:",
&iq->response->qinfo);
if(!generate_sub_request(
iq->response->qinfo.qname,
iq->response->qinfo.qname_len,
iq->response->qinfo.qtype,
iq->response->qinfo.qclass,
qstate, id, iq,
INIT_REQUEST_STATE,
FINISHED_STATE, &subq, 1))
verbose(VERB_ALGO,
"could not validate NXDOMAIN "
"response");
}
}
return next_state(iq, QUERYTARGETS_STATE);
}
return final_state(iq);
} else if(type == RESPONSE_TYPE_REFERRAL) {
/* REFERRAL type responses get a reset of the
* delegation point, and back to the QUERYTARGETS_STATE. */
verbose(VERB_DETAIL, "query response was REFERRAL");
if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
/* we have a referral, no ratelimit, we can send
* our queries to the given name */
infra_ratelimit_dec(qstate->env->infra_cache,
iq->dp->name, iq->dp->namelen,
*qstate->env->now);
}
/* if hardened, only store referral if we asked for it */
if(!qstate->no_cache_store &&
(!qstate->env->cfg->harden_referral_path ||
( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
&& (qstate->query_flags&BIT_RD)
&& !(qstate->query_flags&BIT_CD)
/* we know that all other NS rrsets are scrubbed
* away, thus on referral only one is left.
* see if that equals the query name... */
&& ( /* auth section, but sometimes in answer section*/
reply_find_rrset_section_ns(iq->response->rep,
iq->qchase.qname, iq->qchase.qname_len,
LDNS_RR_TYPE_NS, iq->qchase.qclass)
|| reply_find_rrset_section_an(iq->response->rep,
iq->qchase.qname, iq->qchase.qname_len,
LDNS_RR_TYPE_NS, iq->qchase.qclass)
)
))) {
/* Store the referral under the current query */
/* no prefetch-leeway, since its not the answer */
iter_dns_store(qstate->env, &iq->response->qinfo,
iq->response->rep, 1, 0, 0, NULL, 0);
if(iq->store_parent_NS)
iter_store_parentside_NS(qstate->env,
iq->response->rep);
if(qstate->env->neg_cache)
val_neg_addreferral(qstate->env->neg_cache,
iq->response->rep, iq->dp->name);
}
/* store parent-side-in-zone-glue, if directly queried for */
if(!qstate->no_cache_store && iq->query_for_pside_glue
&& !iq->pside_glue) {
iq->pside_glue = reply_find_rrset(iq->response->rep,
iq->qchase.qname, iq->qchase.qname_len,
iq->qchase.qtype, iq->qchase.qclass);
if(iq->pside_glue) {
log_rrset_key(VERB_ALGO, "found parent-side "
"glue", iq->pside_glue);
iter_store_parentside_rrset(qstate->env,
iq->pside_glue);
}
}
/* Reset the event state, setting the current delegation
* point to the referral. */
iq->deleg_msg = iq->response;
iq->dp = delegpt_from_message(iq->response, qstate->region);
if (qstate->env->cfg->qname_minimisation)
iq->minimisation_state = INIT_MINIMISE_STATE;
if(!iq->dp)
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
qstate->region, iq->dp))
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
iq->store_parent_NS->name) == 0)
iter_merge_retry_counts(iq->dp, iq->store_parent_NS);
delegpt_log(VERB_ALGO, iq->dp);
/* Count this as a referral. */
iq->referral_count++;
iq->sent_count = 0;
/* see if the next dp is a trust anchor, or a DS was sent
* along, indicating dnssec is expected for next zone */
iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
iq->dp, iq->response, iq->qchase.qclass);
/* if dnssec, validating then also fetch the key for the DS */
if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
!(qstate->query_flags&BIT_CD))
generate_dnskey_prefetch(qstate, iq, id);
/* spawn off NS and addr to auth servers for the NS we just
* got in the referral. This gets authoritative answer
* (answer section trust level) rrset.
* right after, we detach the subs, answer goes to cache. */
if(qstate->env->cfg->harden_referral_path)
generate_ns_check(qstate, iq, id);
/* stop current outstanding queries.
* FIXME: should the outstanding queries be waited for and
* handled? Say by a subquery that inherits the outbound_entry.
*/
outbound_list_clear(&iq->outlist);
iq->num_current_queries = 0;
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
iq->num_target_queries = 0;
verbose(VERB_ALGO, "cleared outbound list for next round");
return next_state(iq, QUERYTARGETS_STATE);
} else if(type == RESPONSE_TYPE_CNAME) {
uint8_t* sname = NULL;
size_t snamelen = 0;
/* CNAME type responses get a query restart (i.e., get a
* reset of the query state and go back to INIT_REQUEST_STATE).
*/
verbose(VERB_DETAIL, "query response was CNAME");
if(verbosity >= VERB_ALGO)
log_dns_msg("cname msg", &iq->response->qinfo,
iq->response->rep);
/* if qtype is DS, check we have the right level of answer,
* like grandchild answer but we need the middle, reject it */
if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
&& !(iq->chase_flags&BIT_RD)
&& iter_ds_toolow(iq->response, iq->dp)
&& iter_dp_cangodown(&iq->qchase, iq->dp)) {
outbound_list_clear(&iq->outlist);
iq->num_current_queries = 0;
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
iq->num_target_queries = 0;
return processDSNSFind(qstate, iq, id);
}
/* Process the CNAME response. */
if(!handle_cname_response(qstate, iq, iq->response,
&sname, &snamelen))
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
/* cache the CNAME response under the current query */
/* NOTE : set referral=1, so that rrsets get stored but not
* the partial query answer (CNAME only). */
/* prefetchleeway applied because this updates answer parts */
if(!qstate->no_cache_store)
iter_dns_store(qstate->env, &iq->response->qinfo,
iq->response->rep, 1, qstate->prefetch_leeway,
iq->dp&&iq->dp->has_parent_side_NS, NULL,
qstate->query_flags);
/* set the current request's qname to the new value. */
iq->qchase.qname = sname;
iq->qchase.qname_len = snamelen;
if (qstate->env->cfg->qname_minimisation)
iq->minimisation_state = INIT_MINIMISE_STATE;
/* Clear the query state, since this is a query restart. */
iq->deleg_msg = NULL;
iq->dp = NULL;
iq->dsns_point = NULL;
/* Note the query restart. */
iq->query_restart_count++;
iq->sent_count = 0;
/* stop current outstanding queries.
* FIXME: should the outstanding queries be waited for and
* handled? Say by a subquery that inherits the outbound_entry.
*/
outbound_list_clear(&iq->outlist);
iq->num_current_queries = 0;
fptr_ok(fptr_whitelist_modenv_detach_subs(
qstate->env->detach_subs));
(*qstate->env->detach_subs)(qstate);
iq->num_target_queries = 0;
if(qstate->reply)
sock_list_insert(&qstate->reply_origin,
&qstate->reply->addr, qstate->reply->addrlen,
qstate->region);
verbose(VERB_ALGO, "cleared outbound list for query restart");
/* go to INIT_REQUEST_STATE for new qname. */
return next_state(iq, INIT_REQUEST_STATE);
} else if(type == RESPONSE_TYPE_LAME) {
/* Cache the LAMEness. */
verbose(VERB_DETAIL, "query response was %sLAME",
dnsseclame?"DNSSEC ":"");
if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
log_err("mark lame: mismatch in qname and dpname");
/* throwaway this reply below */
} else if(qstate->reply) {
/* need addr for lameness cache, but we may have
* gotten this from cache, so test to be sure */
if(!infra_set_lame(qstate->env->infra_cache,
&qstate->reply->addr, qstate->reply->addrlen,
iq->dp->name, iq->dp->namelen,
*qstate->env->now, dnsseclame, 0,
iq->qchase.qtype))
log_err("mark host lame: out of memory");
}
} else if(type == RESPONSE_TYPE_REC_LAME) {
/* Cache the LAMEness. */
verbose(VERB_DETAIL, "query response REC_LAME: "
"recursive but not authoritative server");
if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
log_err("mark rec_lame: mismatch in qname and dpname");
/* throwaway this reply below */
} else if(qstate->reply) {
/* need addr for lameness cache, but we may have
* gotten this from cache, so test to be sure */
verbose(VERB_DETAIL, "mark as REC_LAME");
if(!infra_set_lame(qstate->env->infra_cache,
&qstate->reply->addr, qstate->reply->addrlen,
iq->dp->name, iq->dp->namelen,
*qstate->env->now, 0, 1, iq->qchase.qtype))
log_err("mark host lame: out of memory");
}
} else if(type == RESPONSE_TYPE_THROWAWAY) {
/* LAME and THROWAWAY responses are handled the same way.
* In this case, the event is just sent directly back to
* the QUERYTARGETS_STATE without resetting anything,
* because, clearly, the next target must be tried. */
verbose(VERB_DETAIL, "query response was THROWAWAY");
} else {
log_warn("A query response came back with an unknown type: %d",
(int)type);
}
/* LAME, THROWAWAY and "unknown" all end up here.
* Recycle to the QUERYTARGETS state to hopefully try a
* different target. */
if (qstate->env->cfg->qname_minimisation &&
!qstate->env->cfg->qname_minimisation_strict)
iq->minimisation_state = DONOT_MINIMISE_STATE;
return next_state(iq, QUERYTARGETS_STATE);
}
/**
* Return priming query results to interested super querystates.
*
* Sets the delegation point and delegation message (not nonRD queries).
* This is a callback from walk_supers.
*
* @param qstate: priming query state that finished.
* @param id: module id.
* @param forq: the qstate for which priming has been done.
*/
static void
prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
{
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
struct delegpt* dp = NULL;
log_assert(qstate->is_priming || foriq->wait_priming_stub);
log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
/* Convert our response to a delegation point */
dp = delegpt_from_message(qstate->return_msg, forq->region);
if(!dp) {
/* if there is no convertable delegation point, then
* the ANSWER type was (presumably) a negative answer. */
verbose(VERB_ALGO, "prime response was not a positive "
"ANSWER; failing");
foriq->dp = NULL;
foriq->state = QUERYTARGETS_STATE;
return;
}
log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
delegpt_log(VERB_ALGO, dp);
foriq->dp = dp;
foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
if(!foriq->deleg_msg) {
log_err("copy prime response: out of memory");
foriq->dp = NULL;
foriq->state = QUERYTARGETS_STATE;
return;
}
/* root priming responses go to init stage 2, priming stub
* responses to to stage 3. */
if(foriq->wait_priming_stub) {
foriq->state = INIT_REQUEST_3_STATE;
foriq->wait_priming_stub = 0;
} else foriq->state = INIT_REQUEST_2_STATE;
/* because we are finished, the parent will be reactivated */
}
/**
* This handles the response to a priming query. This is used to handle both
* root and stub priming responses. This is basically the equivalent of the
* QUERY_RESP_STATE, but will not handle CNAME responses and will treat
* REFERRALs as ANSWERS. It will also update and reactivate the originating
* event.
*
* @param qstate: query state.
* @param id: module id.
* @return true if the event needs more immediate processing, false if not.
* This state always returns false.
*/
static int
processPrimeResponse(struct module_qstate* qstate, int id)
{
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
enum response_type type;
iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
type = response_type_from_server(
(int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
iq->response, &iq->qchase, iq->dp);
if(type == RESPONSE_TYPE_ANSWER) {
qstate->return_rcode = LDNS_RCODE_NOERROR;
qstate->return_msg = iq->response;
} else {
qstate->return_rcode = LDNS_RCODE_SERVFAIL;
qstate->return_msg = NULL;
}
/* validate the root or stub after priming (if enabled).
* This is the same query as the prime query, but with validation.
* Now that we are primed, the additional queries that validation
* may need can be resolved, such as DLV. */
if(qstate->env->cfg->harden_referral_path) {
struct module_qstate* subq = NULL;
log_nametypeclass(VERB_ALGO, "schedule prime validation",
qstate->qinfo.qname, qstate->qinfo.qtype,
qstate->qinfo.qclass);
if(!generate_sub_request(qstate->qinfo.qname,
qstate->qinfo.qname_len, qstate->qinfo.qtype,
qstate->qinfo.qclass, qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
verbose(VERB_ALGO, "could not generate prime check");
}
generate_a_aaaa_check(qstate, iq, id);
}
/* This event is finished. */
qstate->ext_state[id] = module_finished;
return 0;
}
/**
* Do final processing on responses to target queries. Events reach this
* state after the iterative resolution algorithm terminates. This state is
* responsible for reactiving the original event, and housekeeping related
* to received target responses (caching, updating the current delegation
* point, etc).
* Callback from walk_supers for every super state that is interested in
* the results from this query.
*
* @param qstate: query state.
* @param id: module id.
* @param forq: super query state.
*/
static void
processTargetResponse(struct module_qstate* qstate, int id,
struct module_qstate* forq)
{
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
struct ub_packed_rrset_key* rrset;
struct delegpt_ns* dpns;
log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
foriq->state = QUERYTARGETS_STATE;
log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
/* Tell the originating event that this target query has finished
* (regardless if it succeeded or not). */
foriq->num_target_queries--;
/* check to see if parent event is still interested (in orig name). */
if(!foriq->dp) {
verbose(VERB_ALGO, "subq: parent not interested, was reset");
return; /* not interested anymore */
}
dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
qstate->qinfo.qname_len);
if(!dpns) {
/* If not interested, just stop processing this event */
verbose(VERB_ALGO, "subq: parent not interested anymore");
/* could be because parent was jostled out of the cache,
and a new identical query arrived, that does not want it*/
return;
}
/* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
if(iq->pside_glue) {
/* if the pside_glue is NULL, then it could not be found,
* the done_pside is already set when created and a cache
* entry created in processFinished so nothing to do here */
log_rrset_key(VERB_ALGO, "add parentside glue to dp",
iq->pside_glue);
if(!delegpt_add_rrset(foriq->dp, forq->region,
iq->pside_glue, 1))
log_err("out of memory adding pside glue");
}
/* This response is relevant to the current query, so we
* add (attempt to add, anyway) this target(s) and reactivate
* the original event.
* NOTE: we could only look for the AnswerRRset if the
* response type was ANSWER. */
rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
if(rrset) {
/* if CNAMEs have been followed - add new NS to delegpt. */
/* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
rrset->rk.dname_len)) {
/* if dpns->lame then set newcname ns lame too */
if(!delegpt_add_ns(foriq->dp, forq->region,
rrset->rk.dname, dpns->lame))
log_err("out of memory adding cnamed-ns");
}
/* if dpns->lame then set the address(es) lame too */
if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
dpns->lame))
log_err("out of memory adding targets");
verbose(VERB_ALGO, "added target response");
delegpt_log(VERB_ALGO, foriq->dp);
} else {
verbose(VERB_ALGO, "iterator TargetResponse failed");
dpns->resolved = 1; /* fail the target */
}
}
/**
* Process response for DS NS Find queries, that attempt to find the delegation
* point where we ask the DS query from.
*
* @param qstate: query state.
* @param id: module id.
* @param forq: super query state.
*/
static void
processDSNSResponse(struct module_qstate* qstate, int id,
struct module_qstate* forq)
{
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
/* if the finished (iq->response) query has no NS set: continue
* up to look for the right dp; nothing to change, do DPNSstate */
if(qstate->return_rcode != LDNS_RCODE_NOERROR)
return; /* seek further */
/* find the NS RRset (without allowing CNAMEs) */
if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
qstate->qinfo.qclass)){
return; /* seek further */
}
/* else, store as DP and continue at querytargets */
foriq->state = QUERYTARGETS_STATE;
foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
if(!foriq->dp) {
log_err("out of memory in dsns dp alloc");
return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
}
/* success, go query the querytargets in the new dp (and go down) */
}
/**
* Process response for qclass=ANY queries for a particular class.
* Append to result or error-exit.
*
* @param qstate: query state.
* @param id: module id.
* @param forq: super query state.
*/
static void
processClassResponse(struct module_qstate* qstate, int id,
struct module_qstate* forq)
{
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
struct dns_msg* from = qstate->return_msg;
log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
/* cause servfail for qclass ANY query */
foriq->response = NULL;
foriq->state = FINISHED_STATE;
return;
}
/* append result */
if(!foriq->response) {
/* allocate the response: copy RCODE, sec_state */
foriq->response = dns_copy_msg(from, forq->region);
if(!foriq->response) {
log_err("malloc failed for qclass ANY response");
foriq->state = FINISHED_STATE;
return;
}
foriq->response->qinfo.qclass = forq->qinfo.qclass;
/* qclass ANY does not receive the AA flag on replies */
foriq->response->rep->authoritative = 0;
} else {
struct dns_msg* to = foriq->response;
/* add _from_ this response _to_ existing collection */
/* if there are records, copy RCODE */
/* lower sec_state if this message is lower */
if(from->rep->rrset_count != 0) {
size_t n = from->rep->rrset_count+to->rep->rrset_count;
struct ub_packed_rrset_key** dest, **d;
/* copy appropriate rcode */
to->rep->flags = from->rep->flags;
/* copy rrsets */
if(from->rep->rrset_count > RR_COUNT_MAX ||
to->rep->rrset_count > RR_COUNT_MAX) {
log_err("malloc failed (too many rrsets) in collect ANY");
foriq->state = FINISHED_STATE;
return; /* integer overflow protection */
}
dest = regional_alloc(forq->region, sizeof(dest[0])*n);
if(!dest) {
log_err("malloc failed in collect ANY");
foriq->state = FINISHED_STATE;
return;
}
d = dest;
/* copy AN */
memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
* sizeof(dest[0]));
dest += to->rep->an_numrrsets;
memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
* sizeof(dest[0]));
dest += from->rep->an_numrrsets;
/* copy NS */
memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
to->rep->ns_numrrsets * sizeof(dest[0]));
dest += to->rep->ns_numrrsets;
memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
from->rep->ns_numrrsets * sizeof(dest[0]));
dest += from->rep->ns_numrrsets;
/* copy AR */
memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
to->rep->ns_numrrsets,
to->rep->ar_numrrsets * sizeof(dest[0]));
dest += to->rep->ar_numrrsets;
memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
from->rep->ns_numrrsets,
from->rep->ar_numrrsets * sizeof(dest[0]));
/* update counts */
to->rep->rrsets = d;
to->rep->an_numrrsets += from->rep->an_numrrsets;
to->rep->ns_numrrsets += from->rep->ns_numrrsets;
to->rep->ar_numrrsets += from->rep->ar_numrrsets;
to->rep->rrset_count = n;
}
if(from->rep->security < to->rep->security) /* lowest sec */
to->rep->security = from->rep->security;
if(from->rep->qdcount != 0) /* insert qd if appropriate */
to->rep->qdcount = from->rep->qdcount;
if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
to->rep->ttl = from->rep->ttl;
if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
to->rep->prefetch_ttl = from->rep->prefetch_ttl;
}
/* are we done? */
foriq->num_current_queries --;
if(foriq->num_current_queries == 0)
foriq->state = FINISHED_STATE;
}
/**
* Collect class ANY responses and make them into one response. This
* state is started and it creates queries for all classes (that have
* root hints). The answers are then collected.
*
* @param qstate: query state.
* @param id: module id.
* @return true if the event needs more immediate processing, false if not.
*/
static int
processCollectClass(struct module_qstate* qstate, int id)
{
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
struct module_qstate* subq;
/* If qchase.qclass == 0 then send out queries for all classes.
* Otherwise, do nothing (wait for all answers to arrive and the
* processClassResponse to put them together, and that moves us
* towards the Finished state when done. */
if(iq->qchase.qclass == 0) {
uint16_t c = 0;
iq->qchase.qclass = LDNS_RR_CLASS_ANY;
while(iter_get_next_root(qstate->env->hints,
qstate->env->fwds, &c)) {
/* generate query for this class */
log_nametypeclass(VERB_ALGO, "spawn collect query",
qstate->qinfo.qname, qstate->qinfo.qtype, c);
if(!generate_sub_request(qstate->qinfo.qname,
qstate->qinfo.qname_len, qstate->qinfo.qtype,
c, qstate, id, iq, INIT_REQUEST_STATE,
FINISHED_STATE, &subq,
(int)!(qstate->query_flags&BIT_CD))) {
return error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
}
/* ignore subq, no special init required */
iq->num_current_queries ++;
if(c == 0xffff)
break;
else c++;
}
/* if no roots are configured at all, return */
if(iq->num_current_queries == 0) {
verbose(VERB_ALGO, "No root hints or fwds, giving up "
"on qclass ANY");
return error_response(qstate, id, LDNS_RCODE_REFUSED);
}
/* return false, wait for queries to return */
}
/* if woke up here because of an answer, wait for more answers */
return 0;
}
/**
* This handles the final state for first-tier responses (i.e., responses to
* externally generated queries).
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true if the event needs more processing, false if not. Since this
* is the final state for an event, it always returns false.
*/
static int
processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
log_query_info(VERB_QUERY, "finishing processing for",
&qstate->qinfo);
/* store negative cache element for parent side glue. */
if(!qstate->no_cache_store && iq->query_for_pside_glue
&& !iq->pside_glue)
iter_store_parentside_neg(qstate->env, &qstate->qinfo,
iq->deleg_msg?iq->deleg_msg->rep:
(iq->response?iq->response->rep:NULL));
if(!iq->response) {
verbose(VERB_ALGO, "No response is set, servfail");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* Make sure that the RA flag is set (since the presence of
* this module means that recursion is available) */
iq->response->rep->flags |= BIT_RA;
/* Clear the AA flag */
/* FIXME: does this action go here or in some other module? */
iq->response->rep->flags &= ~BIT_AA;
/* make sure QR flag is on */
iq->response->rep->flags |= BIT_QR;
/* we have finished processing this query */
qstate->ext_state[id] = module_finished;
/* TODO: we are using a private TTL, trim the response. */
/* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
/* prepend any items we have accumulated */
if(iq->an_prepend_list || iq->ns_prepend_list) {
if(!iter_prepend(iq, iq->response, qstate->region)) {
log_err("prepend rrsets: out of memory");
return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
/* reset the query name back */
iq->response->qinfo = qstate->qinfo;
/* the security state depends on the combination */
iq->response->rep->security = sec_status_unchecked;
/* store message with the finished prepended items,
* but only if we did recursion. The nonrecursion referral
* from cache does not need to be stored in the msg cache. */
if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) {
iter_dns_store(qstate->env, &qstate->qinfo,
iq->response->rep, 0, qstate->prefetch_leeway,
iq->dp&&iq->dp->has_parent_side_NS,
qstate->region, qstate->query_flags);
}
}
qstate->return_rcode = LDNS_RCODE_NOERROR;
qstate->return_msg = iq->response;
return 0;
}
/*
* Return priming query results to interestes super querystates.
*
* Sets the delegation point and delegation message (not nonRD queries).
* This is a callback from walk_supers.
*
* @param qstate: query state that finished.
* @param id: module id.
* @param super: the qstate to inform.
*/
void
iter_inform_super(struct module_qstate* qstate, int id,
struct module_qstate* super)
{
if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
processClassResponse(qstate, id, super);
else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
super->minfo[id])->state == DSNS_FIND_STATE)
processDSNSResponse(qstate, id, super);
else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
error_supers(qstate, id, super);
else if(qstate->is_priming)
prime_supers(qstate, id, super);
else processTargetResponse(qstate, id, super);
}
/**
* Handle iterator state.
* Handle events. This is the real processing loop for events, responsible
* for moving events through the various states. If a processing method
* returns true, then it will be advanced to the next state. If false, then
* processing will stop.
*
* @param qstate: query state.
* @param ie: iterator shared global environment.
* @param iq: iterator query state.
* @param id: module id.
*/
static void
iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id)
{
int cont = 1;
while(cont) {
verbose(VERB_ALGO, "iter_handle processing q with state %s",
iter_state_to_string(iq->state));
switch(iq->state) {
case INIT_REQUEST_STATE:
cont = processInitRequest(qstate, iq, ie, id);
break;
case INIT_REQUEST_2_STATE:
cont = processInitRequest2(qstate, iq, id);
break;
case INIT_REQUEST_3_STATE:
cont = processInitRequest3(qstate, iq, id);
break;
case QUERYTARGETS_STATE:
cont = processQueryTargets(qstate, iq, ie, id);
break;
case QUERY_RESP_STATE:
cont = processQueryResponse(qstate, iq, id);
break;
case PRIME_RESP_STATE:
cont = processPrimeResponse(qstate, id);
break;
case COLLECT_CLASS_STATE:
cont = processCollectClass(qstate, id);
break;
case DSNS_FIND_STATE:
cont = processDSNSFind(qstate, iq, id);
break;
case FINISHED_STATE:
cont = processFinished(qstate, iq, id);
break;
default:
log_warn("iterator: invalid state: %d",
iq->state);
cont = 0;
break;
}
}
}
/**
* This is the primary entry point for processing request events. Note that
* this method should only be used by external modules.
* @param qstate: query state.
* @param ie: iterator shared global environment.
* @param iq: iterator query state.
* @param id: module id.
*/
static void
process_request(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id)
{
/* external requests start in the INIT state, and finish using the
* FINISHED state. */
iq->state = INIT_REQUEST_STATE;
iq->final_state = FINISHED_STATE;
verbose(VERB_ALGO, "process_request: new external request event");
iter_handle(qstate, iq, ie, id);
}
/** process authoritative server reply */
static void
process_response(struct module_qstate* qstate, struct iter_qstate* iq,
struct iter_env* ie, int id, struct outbound_entry* outbound,
enum module_ev event)
{
struct msg_parse* prs;
struct edns_data edns;
sldns_buffer* pkt;
verbose(VERB_ALGO, "process_response: new external response event");
iq->response = NULL;
iq->state = QUERY_RESP_STATE;
if(event == module_event_noreply || event == module_event_error) {
if(event == module_event_noreply && iq->sent_count >= 3 &&
qstate->env->cfg->use_caps_bits_for_id &&
!iq->caps_fallback) {
/* start fallback */
iq->caps_fallback = 1;
iq->caps_server = 0;
iq->caps_reply = NULL;
iq->caps_response = NULL;
iq->state = QUERYTARGETS_STATE;
iq->num_current_queries--;
/* need fresh attempts for the 0x20 fallback, if
* that was the cause for the failure */
iter_dec_attempts(iq->dp, 3);
verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback");
goto handle_it;
}
goto handle_it;
}
if( (event != module_event_reply && event != module_event_capsfail)
|| !qstate->reply) {
log_err("Bad event combined with response");
outbound_list_remove(&iq->outlist, outbound);
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return;
}
/* parse message */
prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
sizeof(struct msg_parse));
if(!prs) {
log_err("out of memory on incoming message");
/* like packet got dropped */
goto handle_it;
}
memset(prs, 0, sizeof(*prs));
memset(&edns, 0, sizeof(edns));
pkt = qstate->reply->c->buffer;
sldns_buffer_set_position(pkt, 0);
if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
verbose(VERB_ALGO, "parse error on reply packet");
goto handle_it;
}
/* edns is not examined, but removed from message to help cache */
if(parse_extract_edns(prs, &edns, qstate->env->scratch) !=
LDNS_RCODE_NOERROR)
goto handle_it;
/* Copy the edns options we may got from the back end */
if(edns.opt_list) {
qstate->edns_opts_back_in = edns_opt_copy_region(edns.opt_list,
qstate->region);
if(!qstate->edns_opts_back_in) {
log_err("out of memory on incoming message");
/* like packet got dropped */
goto handle_it;
}
if(!inplace_cb_edns_back_parsed_call(qstate->env, qstate)) {
log_err("unable to call edns_back_parsed callback");
goto handle_it;
}
}
/* remove CD-bit, we asked for in case we handle validation ourself */
prs->flags &= ~BIT_CD;
/* normalize and sanitize: easy to delete items from linked lists */
if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name,
qstate->env->scratch, qstate->env, ie)) {
/* if 0x20 enabled, start fallback, but we have no message */
if(event == module_event_capsfail && !iq->caps_fallback) {
iq->caps_fallback = 1;
iq->caps_server = 0;
iq->caps_reply = NULL;
iq->caps_response = NULL;
iq->state = QUERYTARGETS_STATE;
iq->num_current_queries--;
verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response");
}
goto handle_it;
}
/* allocate response dns_msg in region */
iq->response = dns_alloc_msg(pkt, prs, qstate->region);
if(!iq->response)
goto handle_it;
log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
&qstate->reply->addr, qstate->reply->addrlen);
if(verbosity >= VERB_ALGO)
log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
iq->response->rep);
if(event == module_event_capsfail || iq->caps_fallback) {
/* for fallback we care about main answer, not additionals */
/* removing that makes comparison more likely to succeed */
caps_strip_reply(iq->response->rep);
if(!iq->caps_fallback) {
/* start fallback */
iq->caps_fallback = 1;
iq->caps_server = 0;
iq->caps_reply = iq->response->rep;
iq->caps_response = iq->response;
iq->state = QUERYTARGETS_STATE;
iq->num_current_queries--;
verbose(VERB_DETAIL, "Capsforid: starting fallback");
goto handle_it;
} else {
/* check if reply is the same, otherwise, fail */
if(!iq->caps_reply) {
iq->caps_reply = iq->response->rep;
iq->caps_response = iq->response;
iq->caps_server = -1; /*become zero at ++,
so that we start the full set of trials */
} else if(caps_failed_rcode(iq->caps_reply) &&
!caps_failed_rcode(iq->response->rep)) {
/* prefer to upgrade to non-SERVFAIL */
iq->caps_reply = iq->response->rep;
iq->caps_response = iq->response;
} else if(!caps_failed_rcode(iq->caps_reply) &&
caps_failed_rcode(iq->response->rep)) {
/* if we have non-SERVFAIL as answer then
* we can ignore SERVFAILs for the equality
* comparison */
/* no instructions here, skip other else */
} else if(caps_failed_rcode(iq->caps_reply) &&
caps_failed_rcode(iq->response->rep)) {
/* failure is same as other failure in fallbk*/
/* no instructions here, skip other else */
} else if(!reply_equal(iq->response->rep, iq->caps_reply,
qstate->env->scratch)) {
verbose(VERB_DETAIL, "Capsforid fallback: "
"getting different replies, failed");
outbound_list_remove(&iq->outlist, outbound);
(void)error_response(qstate, id,
LDNS_RCODE_SERVFAIL);
return;
}
/* continue the fallback procedure at next server */
iq->caps_server++;
iq->state = QUERYTARGETS_STATE;
iq->num_current_queries--;
verbose(VERB_DETAIL, "Capsforid: reply is equal. "
"go to next fallback");
goto handle_it;
}
}
iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
handle_it:
outbound_list_remove(&iq->outlist, outbound);
iter_handle(qstate, iq, ie, id);
}
void
iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
struct outbound_entry* outbound)
{
struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
id, strextstate(qstate->ext_state[id]), strmodulevent(event));
if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
&qstate->qinfo);
if(iq && qstate->qinfo.qname != iq->qchase.qname)
log_query_info(VERB_QUERY, "iterator operate: chased to",
&iq->qchase);
/* perform iterator state machine */
if((event == module_event_new || event == module_event_pass) &&
iq == NULL) {
if(!iter_new(qstate, id)) {
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return;
}
iq = (struct iter_qstate*)qstate->minfo[id];
process_request(qstate, iq, ie, id);
return;
}
if(iq && event == module_event_pass) {
iter_handle(qstate, iq, ie, id);
return;
}
if(iq && outbound) {
process_response(qstate, iq, ie, id, outbound, event);
return;
}
if(event == module_event_error) {
verbose(VERB_ALGO, "got called with event error, giving up");
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
return;
}
log_err("bad event for iterator");
(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
}
void
iter_clear(struct module_qstate* qstate, int id)
{
struct iter_qstate* iq;
if(!qstate)
return;
iq = (struct iter_qstate*)qstate->minfo[id];
if(iq) {
outbound_list_clear(&iq->outlist);
if(iq->target_count && --iq->target_count[0] == 0)
free(iq->target_count);
iq->num_current_queries = 0;
}
qstate->minfo[id] = NULL;
}
size_t
iter_get_mem(struct module_env* env, int id)
{
struct iter_env* ie = (struct iter_env*)env->modinfo[id];
if(!ie)
return 0;
return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
+ donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
}
/**
* The iterator function block
*/
static struct module_func_block iter_block = {
"iterator",
&iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
&iter_clear, &iter_get_mem
};
struct module_func_block*
iter_get_funcblock(void)
{
return &iter_block;
}
const char*
iter_state_to_string(enum iter_state state)
{
switch (state)
{
case INIT_REQUEST_STATE :
return "INIT REQUEST STATE";
case INIT_REQUEST_2_STATE :
return "INIT REQUEST STATE (stage 2)";
case INIT_REQUEST_3_STATE:
return "INIT REQUEST STATE (stage 3)";
case QUERYTARGETS_STATE :
return "QUERY TARGETS STATE";
case PRIME_RESP_STATE :
return "PRIME RESPONSE STATE";
case COLLECT_CLASS_STATE :
return "COLLECT CLASS STATE";
case DSNS_FIND_STATE :
return "DSNS FIND STATE";
case QUERY_RESP_STATE :
return "QUERY RESPONSE STATE";
case FINISHED_STATE :
return "FINISHED RESPONSE STATE";
default :
return "UNKNOWN ITER STATE";
}
}
int
iter_state_is_responsestate(enum iter_state s)
{
switch(s) {
case INIT_REQUEST_STATE :
case INIT_REQUEST_2_STATE :
case INIT_REQUEST_3_STATE :
case QUERYTARGETS_STATE :
case COLLECT_CLASS_STATE :
return 0;
default:
break;
}
return 1;
}