monero/external/unbound/services/cache/dns.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

911 lines
29 KiB
C

/*
* services/cache/dns.c - Cache services for DNS using msg and rrset caches.
*
* 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 the DNS cache.
*/
#include "config.h"
#include "iterator/iter_delegpt.h"
#include "validator/val_nsec.h"
#include "services/cache/dns.h"
#include "services/cache/rrset.h"
#include "util/data/msgreply.h"
#include "util/data/packed_rrset.h"
#include "util/data/dname.h"
#include "util/module.h"
#include "util/net_help.h"
#include "util/regional.h"
#include "util/config_file.h"
#include "sldns/sbuffer.h"
/** store rrsets in the rrset cache.
* @param env: module environment with caches.
* @param rep: contains list of rrsets to store.
* @param now: current time.
* @param leeway: during prefetch how much leeway to update TTLs.
* This makes rrsets (other than type NS) timeout sooner so they get
* updated with a new full TTL.
* Type NS does not get this, because it must not be refreshed from the
* child domain, but keep counting down properly.
* @param pside: if from parentside discovered NS, so that its NS is okay
* in a prefetch situation to be updated (without becoming sticky).
* @param qrep: update rrsets here if cache is better
* @param region: for qrep allocs.
*/
static void
store_rrsets(struct module_env* env, struct reply_info* rep, time_t now,
time_t leeway, int pside, struct reply_info* qrep,
struct regional* region)
{
size_t i;
/* see if rrset already exists in cache, if not insert it. */
for(i=0; i<rep->rrset_count; i++) {
rep->ref[i].key = rep->rrsets[i];
rep->ref[i].id = rep->rrsets[i]->id;
/* update ref if it was in the cache */
switch(rrset_cache_update(env->rrset_cache, &rep->ref[i],
env->alloc, now + ((ntohs(rep->ref[i].key->rk.type)==
LDNS_RR_TYPE_NS && !pside)?0:leeway))) {
case 0: /* ref unchanged, item inserted */
break;
case 2: /* ref updated, cache is superior */
if(region) {
struct ub_packed_rrset_key* ck;
lock_rw_rdlock(&rep->ref[i].key->entry.lock);
/* if deleted rrset, do not copy it */
if(rep->ref[i].key->id == 0)
ck = NULL;
else ck = packed_rrset_copy_region(
rep->ref[i].key, region, now);
lock_rw_unlock(&rep->ref[i].key->entry.lock);
if(ck) {
/* use cached copy if memory allows */
qrep->rrsets[i] = ck;
}
}
/* no break: also copy key item */
case 1: /* ref updated, item inserted */
rep->rrsets[i] = rep->ref[i].key;
}
}
}
void
dns_cache_store_msg(struct module_env* env, struct query_info* qinfo,
hashvalue_type hash, struct reply_info* rep, time_t leeway, int pside,
struct reply_info* qrep, struct regional* region)
{
struct msgreply_entry* e;
time_t ttl = rep->ttl;
size_t i;
/* store RRsets */
for(i=0; i<rep->rrset_count; i++) {
rep->ref[i].key = rep->rrsets[i];
rep->ref[i].id = rep->rrsets[i]->id;
}
/* there was a reply_info_sortref(rep) here but it seems to be
* unnecessary, because the cache gets locked per rrset. */
reply_info_set_ttls(rep, *env->now);
store_rrsets(env, rep, *env->now, leeway, pside, qrep, region);
if(ttl == 0) {
/* we do not store the message, but we did store the RRs,
* which could be useful for delegation information */
verbose(VERB_ALGO, "TTL 0: dropped msg from cache");
free(rep);
return;
}
/* store msg in the cache */
reply_info_sortref(rep);
if(!(e = query_info_entrysetup(qinfo, rep, hash))) {
log_err("store_msg: malloc failed");
return;
}
slabhash_insert(env->msg_cache, hash, &e->entry, rep, env->alloc);
}
/** find closest NS or DNAME and returns the rrset (locked) */
static struct ub_packed_rrset_key*
find_closest_of_type(struct module_env* env, uint8_t* qname, size_t qnamelen,
uint16_t qclass, time_t now, uint16_t searchtype, int stripfront)
{
struct ub_packed_rrset_key *rrset;
uint8_t lablen;
if(stripfront) {
/* strip off so that DNAMEs have strict subdomain match */
lablen = *qname;
qname += lablen + 1;
qnamelen -= lablen + 1;
}
/* snip off front part of qname until the type is found */
while(qnamelen > 0) {
if((rrset = rrset_cache_lookup(env->rrset_cache, qname,
qnamelen, searchtype, qclass, 0, now, 0)))
return rrset;
/* snip off front label */
lablen = *qname;
qname += lablen + 1;
qnamelen -= lablen + 1;
}
return NULL;
}
/** add addr to additional section */
static void
addr_to_additional(struct ub_packed_rrset_key* rrset, struct regional* region,
struct dns_msg* msg, time_t now)
{
if((msg->rep->rrsets[msg->rep->rrset_count] =
packed_rrset_copy_region(rrset, region, now))) {
msg->rep->ar_numrrsets++;
msg->rep->rrset_count++;
}
}
/** lookup message in message cache */
static struct msgreply_entry*
msg_cache_lookup(struct module_env* env, uint8_t* qname, size_t qnamelen,
uint16_t qtype, uint16_t qclass, uint16_t flags, time_t now, int wr)
{
struct lruhash_entry* e;
struct query_info k;
hashvalue_type h;
k.qname = qname;
k.qname_len = qnamelen;
k.qtype = qtype;
k.qclass = qclass;
k.local_alias = NULL;
h = query_info_hash(&k, flags);
e = slabhash_lookup(env->msg_cache, h, &k, wr);
if(!e) return NULL;
if( now > ((struct reply_info*)e->data)->ttl ) {
lock_rw_unlock(&e->lock);
return NULL;
}
return (struct msgreply_entry*)e->key;
}
/** find and add A and AAAA records for nameservers in delegpt */
static int
find_add_addrs(struct module_env* env, uint16_t qclass,
struct regional* region, struct delegpt* dp, time_t now,
struct dns_msg** msg)
{
struct delegpt_ns* ns;
struct msgreply_entry* neg;
struct ub_packed_rrset_key* akey;
for(ns = dp->nslist; ns; ns = ns->next) {
akey = rrset_cache_lookup(env->rrset_cache, ns->name,
ns->namelen, LDNS_RR_TYPE_A, qclass, 0, now, 0);
if(akey) {
if(!delegpt_add_rrset_A(dp, region, akey, 0)) {
lock_rw_unlock(&akey->entry.lock);
return 0;
}
if(msg)
addr_to_additional(akey, region, *msg, now);
lock_rw_unlock(&akey->entry.lock);
} else {
/* BIT_CD on false because delegpt lookup does
* not use dns64 translation */
neg = msg_cache_lookup(env, ns->name, ns->namelen,
LDNS_RR_TYPE_A, qclass, 0, now, 0);
if(neg) {
delegpt_add_neg_msg(dp, neg);
lock_rw_unlock(&neg->entry.lock);
}
}
akey = rrset_cache_lookup(env->rrset_cache, ns->name,
ns->namelen, LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
if(akey) {
if(!delegpt_add_rrset_AAAA(dp, region, akey, 0)) {
lock_rw_unlock(&akey->entry.lock);
return 0;
}
if(msg)
addr_to_additional(akey, region, *msg, now);
lock_rw_unlock(&akey->entry.lock);
} else {
/* BIT_CD on false because delegpt lookup does
* not use dns64 translation */
neg = msg_cache_lookup(env, ns->name, ns->namelen,
LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
if(neg) {
delegpt_add_neg_msg(dp, neg);
lock_rw_unlock(&neg->entry.lock);
}
}
}
return 1;
}
/** find and add A and AAAA records for missing nameservers in delegpt */
int
cache_fill_missing(struct module_env* env, uint16_t qclass,
struct regional* region, struct delegpt* dp)
{
struct delegpt_ns* ns;
struct msgreply_entry* neg;
struct ub_packed_rrset_key* akey;
time_t now = *env->now;
for(ns = dp->nslist; ns; ns = ns->next) {
akey = rrset_cache_lookup(env->rrset_cache, ns->name,
ns->namelen, LDNS_RR_TYPE_A, qclass, 0, now, 0);
if(akey) {
if(!delegpt_add_rrset_A(dp, region, akey, ns->lame)) {
lock_rw_unlock(&akey->entry.lock);
return 0;
}
log_nametypeclass(VERB_ALGO, "found in cache",
ns->name, LDNS_RR_TYPE_A, qclass);
lock_rw_unlock(&akey->entry.lock);
} else {
/* BIT_CD on false because delegpt lookup does
* not use dns64 translation */
neg = msg_cache_lookup(env, ns->name, ns->namelen,
LDNS_RR_TYPE_A, qclass, 0, now, 0);
if(neg) {
delegpt_add_neg_msg(dp, neg);
lock_rw_unlock(&neg->entry.lock);
}
}
akey = rrset_cache_lookup(env->rrset_cache, ns->name,
ns->namelen, LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
if(akey) {
if(!delegpt_add_rrset_AAAA(dp, region, akey, ns->lame)) {
lock_rw_unlock(&akey->entry.lock);
return 0;
}
log_nametypeclass(VERB_ALGO, "found in cache",
ns->name, LDNS_RR_TYPE_AAAA, qclass);
lock_rw_unlock(&akey->entry.lock);
} else {
/* BIT_CD on false because delegpt lookup does
* not use dns64 translation */
neg = msg_cache_lookup(env, ns->name, ns->namelen,
LDNS_RR_TYPE_AAAA, qclass, 0, now, 0);
if(neg) {
delegpt_add_neg_msg(dp, neg);
lock_rw_unlock(&neg->entry.lock);
}
}
}
return 1;
}
/** find and add DS or NSEC to delegation msg */
static void
find_add_ds(struct module_env* env, struct regional* region,
struct dns_msg* msg, struct delegpt* dp, time_t now)
{
/* Lookup the DS or NSEC at the delegation point. */
struct ub_packed_rrset_key* rrset = rrset_cache_lookup(
env->rrset_cache, dp->name, dp->namelen, LDNS_RR_TYPE_DS,
msg->qinfo.qclass, 0, now, 0);
if(!rrset) {
/* NOTE: this won't work for alternate NSEC schemes
* (opt-in, NSEC3) */
rrset = rrset_cache_lookup(env->rrset_cache, dp->name,
dp->namelen, LDNS_RR_TYPE_NSEC, msg->qinfo.qclass,
0, now, 0);
/* Note: the PACKED_RRSET_NSEC_AT_APEX flag is not used.
* since this is a referral, we need the NSEC at the parent
* side of the zone cut, not the NSEC at apex side. */
if(rrset && nsec_has_type(rrset, LDNS_RR_TYPE_DS)) {
lock_rw_unlock(&rrset->entry.lock);
rrset = NULL; /* discard wrong NSEC */
}
}
if(rrset) {
/* add it to auth section. This is the second rrset. */
if((msg->rep->rrsets[msg->rep->rrset_count] =
packed_rrset_copy_region(rrset, region, now))) {
msg->rep->ns_numrrsets++;
msg->rep->rrset_count++;
}
lock_rw_unlock(&rrset->entry.lock);
}
}
struct dns_msg*
dns_msg_create(uint8_t* qname, size_t qnamelen, uint16_t qtype,
uint16_t qclass, struct regional* region, size_t capacity)
{
struct dns_msg* msg = (struct dns_msg*)regional_alloc(region,
sizeof(struct dns_msg));
if(!msg)
return NULL;
msg->qinfo.qname = regional_alloc_init(region, qname, qnamelen);
if(!msg->qinfo.qname)
return NULL;
msg->qinfo.qname_len = qnamelen;
msg->qinfo.qtype = qtype;
msg->qinfo.qclass = qclass;
msg->qinfo.local_alias = NULL;
/* non-packed reply_info, because it needs to grow the array */
msg->rep = (struct reply_info*)regional_alloc_zero(region,
sizeof(struct reply_info)-sizeof(struct rrset_ref));
if(!msg->rep)
return NULL;
if(capacity > RR_COUNT_MAX)
return NULL; /* integer overflow protection */
msg->rep->flags = BIT_QR; /* with QR, no AA */
msg->rep->qdcount = 1;
msg->rep->rrsets = (struct ub_packed_rrset_key**)
regional_alloc(region,
capacity*sizeof(struct ub_packed_rrset_key*));
if(!msg->rep->rrsets)
return NULL;
return msg;
}
int
dns_msg_authadd(struct dns_msg* msg, struct regional* region,
struct ub_packed_rrset_key* rrset, time_t now)
{
if(!(msg->rep->rrsets[msg->rep->rrset_count++] =
packed_rrset_copy_region(rrset, region, now)))
return 0;
msg->rep->ns_numrrsets++;
return 1;
}
/** add rrset to answer section */
static int
dns_msg_ansadd(struct dns_msg* msg, struct regional* region,
struct ub_packed_rrset_key* rrset, time_t now)
{
if(!(msg->rep->rrsets[msg->rep->rrset_count++] =
packed_rrset_copy_region(rrset, region, now)))
return 0;
msg->rep->an_numrrsets++;
return 1;
}
struct delegpt*
dns_cache_find_delegation(struct module_env* env, uint8_t* qname,
size_t qnamelen, uint16_t qtype, uint16_t qclass,
struct regional* region, struct dns_msg** msg, time_t now)
{
/* try to find closest NS rrset */
struct ub_packed_rrset_key* nskey;
struct packed_rrset_data* nsdata;
struct delegpt* dp;
nskey = find_closest_of_type(env, qname, qnamelen, qclass, now,
LDNS_RR_TYPE_NS, 0);
if(!nskey) /* hope the caller has hints to prime or something */
return NULL;
nsdata = (struct packed_rrset_data*)nskey->entry.data;
/* got the NS key, create delegation point */
dp = delegpt_create(region);
if(!dp || !delegpt_set_name(dp, region, nskey->rk.dname)) {
lock_rw_unlock(&nskey->entry.lock);
log_err("find_delegation: out of memory");
return NULL;
}
/* create referral message */
if(msg) {
/* allocate the array to as much as we could need:
* NS rrset + DS/NSEC rrset +
* A rrset for every NS RR
* AAAA rrset for every NS RR
*/
*msg = dns_msg_create(qname, qnamelen, qtype, qclass, region,
2 + nsdata->count*2);
if(!*msg || !dns_msg_authadd(*msg, region, nskey, now)) {
lock_rw_unlock(&nskey->entry.lock);
log_err("find_delegation: out of memory");
return NULL;
}
}
if(!delegpt_rrset_add_ns(dp, region, nskey, 0))
log_err("find_delegation: addns out of memory");
lock_rw_unlock(&nskey->entry.lock); /* first unlock before next lookup*/
/* find and add DS/NSEC (if any) */
if(msg)
find_add_ds(env, region, *msg, dp, now);
/* find and add A entries */
if(!find_add_addrs(env, qclass, region, dp, now, msg))
log_err("find_delegation: addrs out of memory");
return dp;
}
/** allocate dns_msg from query_info and reply_info */
static struct dns_msg*
gen_dns_msg(struct regional* region, struct query_info* q, size_t num)
{
struct dns_msg* msg = (struct dns_msg*)regional_alloc(region,
sizeof(struct dns_msg));
if(!msg)
return NULL;
memcpy(&msg->qinfo, q, sizeof(struct query_info));
msg->qinfo.qname = regional_alloc_init(region, q->qname, q->qname_len);
if(!msg->qinfo.qname)
return NULL;
/* allocate replyinfo struct and rrset key array separately */
msg->rep = (struct reply_info*)regional_alloc(region,
sizeof(struct reply_info) - sizeof(struct rrset_ref));
if(!msg->rep)
return NULL;
if(num > RR_COUNT_MAX)
return NULL; /* integer overflow protection */
msg->rep->rrsets = (struct ub_packed_rrset_key**)
regional_alloc(region,
num * sizeof(struct ub_packed_rrset_key*));
if(!msg->rep->rrsets)
return NULL;
return msg;
}
struct dns_msg*
tomsg(struct module_env* env, struct query_info* q, struct reply_info* r,
struct regional* region, time_t now, struct regional* scratch)
{
struct dns_msg* msg;
size_t i;
if(now > r->ttl)
return NULL;
msg = gen_dns_msg(region, q, r->rrset_count);
if(!msg)
return NULL;
msg->rep->flags = r->flags;
msg->rep->qdcount = r->qdcount;
msg->rep->ttl = r->ttl - now;
if(r->prefetch_ttl > now)
msg->rep->prefetch_ttl = r->prefetch_ttl - now;
else msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
msg->rep->security = r->security;
msg->rep->an_numrrsets = r->an_numrrsets;
msg->rep->ns_numrrsets = r->ns_numrrsets;
msg->rep->ar_numrrsets = r->ar_numrrsets;
msg->rep->rrset_count = r->rrset_count;
msg->rep->authoritative = r->authoritative;
if(!rrset_array_lock(r->ref, r->rrset_count, now))
return NULL;
if(r->an_numrrsets > 0 && (r->rrsets[0]->rk.type == htons(
LDNS_RR_TYPE_CNAME) || r->rrsets[0]->rk.type == htons(
LDNS_RR_TYPE_DNAME)) && !reply_check_cname_chain(q, r)) {
/* cname chain is now invalid, reconstruct msg */
rrset_array_unlock(r->ref, r->rrset_count);
return NULL;
}
if(r->security == sec_status_secure && !reply_all_rrsets_secure(r)) {
/* message rrsets have changed status, revalidate */
rrset_array_unlock(r->ref, r->rrset_count);
return NULL;
}
for(i=0; i<msg->rep->rrset_count; i++) {
msg->rep->rrsets[i] = packed_rrset_copy_region(r->rrsets[i],
region, now);
if(!msg->rep->rrsets[i]) {
rrset_array_unlock(r->ref, r->rrset_count);
return NULL;
}
}
if(env)
rrset_array_unlock_touch(env->rrset_cache, scratch, r->ref,
r->rrset_count);
else
rrset_array_unlock(r->ref, r->rrset_count);
return msg;
}
/** synthesize RRset-only response from cached RRset item */
static struct dns_msg*
rrset_msg(struct ub_packed_rrset_key* rrset, struct regional* region,
time_t now, struct query_info* q)
{
struct dns_msg* msg;
struct packed_rrset_data* d = (struct packed_rrset_data*)
rrset->entry.data;
if(now > d->ttl)
return NULL;
msg = gen_dns_msg(region, q, 1); /* only the CNAME (or other) RRset */
if(!msg)
return NULL;
msg->rep->flags = BIT_QR; /* reply, no AA, no error */
msg->rep->authoritative = 0; /* reply stored in cache can't be authoritative */
msg->rep->qdcount = 1;
msg->rep->ttl = d->ttl - now;
msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
msg->rep->security = sec_status_unchecked;
msg->rep->an_numrrsets = 1;
msg->rep->ns_numrrsets = 0;
msg->rep->ar_numrrsets = 0;
msg->rep->rrset_count = 1;
msg->rep->rrsets[0] = packed_rrset_copy_region(rrset, region, now);
if(!msg->rep->rrsets[0]) /* copy CNAME */
return NULL;
return msg;
}
/** synthesize DNAME+CNAME response from cached DNAME item */
static struct dns_msg*
synth_dname_msg(struct ub_packed_rrset_key* rrset, struct regional* region,
time_t now, struct query_info* q)
{
struct dns_msg* msg;
struct ub_packed_rrset_key* ck;
struct packed_rrset_data* newd, *d = (struct packed_rrset_data*)
rrset->entry.data;
uint8_t* newname, *dtarg = NULL;
size_t newlen, dtarglen;
if(now > d->ttl)
return NULL;
/* only allow validated (with DNSSEC) DNAMEs used from cache
* for insecure DNAMEs, query again. */
if(d->security != sec_status_secure)
return NULL;
msg = gen_dns_msg(region, q, 2); /* DNAME + CNAME RRset */
if(!msg)
return NULL;
msg->rep->flags = BIT_QR; /* reply, no AA, no error */
msg->rep->authoritative = 0; /* reply stored in cache can't be authoritative */
msg->rep->qdcount = 1;
msg->rep->ttl = d->ttl - now;
msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl);
msg->rep->security = sec_status_unchecked;
msg->rep->an_numrrsets = 1;
msg->rep->ns_numrrsets = 0;
msg->rep->ar_numrrsets = 0;
msg->rep->rrset_count = 1;
msg->rep->rrsets[0] = packed_rrset_copy_region(rrset, region, now);
if(!msg->rep->rrsets[0]) /* copy DNAME */
return NULL;
/* synth CNAME rrset */
get_cname_target(rrset, &dtarg, &dtarglen);
if(!dtarg)
return NULL;
newlen = q->qname_len + dtarglen - rrset->rk.dname_len;
if(newlen > LDNS_MAX_DOMAINLEN) {
msg->rep->flags |= LDNS_RCODE_YXDOMAIN;
return msg;
}
newname = (uint8_t*)regional_alloc(region, newlen);
if(!newname)
return NULL;
/* new name is concatenation of qname front (without DNAME owner)
* and DNAME target name */
memcpy(newname, q->qname, q->qname_len-rrset->rk.dname_len);
memmove(newname+(q->qname_len-rrset->rk.dname_len), dtarg, dtarglen);
/* create rest of CNAME rrset */
ck = (struct ub_packed_rrset_key*)regional_alloc(region,
sizeof(struct ub_packed_rrset_key));
if(!ck)
return NULL;
memset(&ck->entry, 0, sizeof(ck->entry));
msg->rep->rrsets[1] = ck;
ck->entry.key = ck;
ck->rk.type = htons(LDNS_RR_TYPE_CNAME);
ck->rk.rrset_class = rrset->rk.rrset_class;
ck->rk.flags = 0;
ck->rk.dname = regional_alloc_init(region, q->qname, q->qname_len);
if(!ck->rk.dname)
return NULL;
ck->rk.dname_len = q->qname_len;
ck->entry.hash = rrset_key_hash(&ck->rk);
newd = (struct packed_rrset_data*)regional_alloc_zero(region,
sizeof(struct packed_rrset_data) + sizeof(size_t) +
sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)
+ newlen);
if(!newd)
return NULL;
ck->entry.data = newd;
newd->ttl = 0; /* 0 for synthesized CNAME TTL */
newd->count = 1;
newd->rrsig_count = 0;
newd->trust = rrset_trust_ans_noAA;
newd->rr_len = (size_t*)((uint8_t*)newd +
sizeof(struct packed_rrset_data));
newd->rr_len[0] = newlen + sizeof(uint16_t);
packed_rrset_ptr_fixup(newd);
newd->rr_ttl[0] = newd->ttl;
msg->rep->ttl = newd->ttl;
msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(newd->ttl);
sldns_write_uint16(newd->rr_data[0], newlen);
memmove(newd->rr_data[0] + sizeof(uint16_t), newname, newlen);
msg->rep->an_numrrsets ++;
msg->rep->rrset_count ++;
return msg;
}
/** Fill TYPE_ANY response with some data from cache */
static struct dns_msg*
fill_any(struct module_env* env,
uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass,
struct regional* region)
{
time_t now = *env->now;
struct dns_msg* msg = NULL;
uint16_t lookup[] = {LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA,
LDNS_RR_TYPE_MX, LDNS_RR_TYPE_SOA, LDNS_RR_TYPE_NS,
LDNS_RR_TYPE_DNAME, 0};
int i, num=6; /* number of RR types to look up */
log_assert(lookup[num] == 0);
for(i=0; i<num; i++) {
/* look up this RR for inclusion in type ANY response */
struct ub_packed_rrset_key* rrset = rrset_cache_lookup(
env->rrset_cache, qname, qnamelen, lookup[i],
qclass, 0, now, 0);
struct packed_rrset_data *d;
if(!rrset)
continue;
/* only if rrset from answer section */
d = (struct packed_rrset_data*)rrset->entry.data;
if(d->trust == rrset_trust_add_noAA ||
d->trust == rrset_trust_auth_noAA ||
d->trust == rrset_trust_add_AA ||
d->trust == rrset_trust_auth_AA) {
lock_rw_unlock(&rrset->entry.lock);
continue;
}
/* create msg if none */
if(!msg) {
msg = dns_msg_create(qname, qnamelen, qtype, qclass,
region, (size_t)(num-i));
if(!msg) {
lock_rw_unlock(&rrset->entry.lock);
return NULL;
}
}
/* add RRset to response */
if(!dns_msg_ansadd(msg, region, rrset, now)) {
lock_rw_unlock(&rrset->entry.lock);
return NULL;
}
lock_rw_unlock(&rrset->entry.lock);
}
return msg;
}
struct dns_msg*
dns_cache_lookup(struct module_env* env,
uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass,
uint16_t flags, struct regional* region, struct regional* scratch)
{
struct lruhash_entry* e;
struct query_info k;
hashvalue_type h;
time_t now = *env->now;
struct ub_packed_rrset_key* rrset;
/* lookup first, this has both NXdomains and ANSWER responses */
k.qname = qname;
k.qname_len = qnamelen;
k.qtype = qtype;
k.qclass = qclass;
k.local_alias = NULL;
h = query_info_hash(&k, flags);
e = slabhash_lookup(env->msg_cache, h, &k, 0);
if(e) {
struct msgreply_entry* key = (struct msgreply_entry*)e->key;
struct reply_info* data = (struct reply_info*)e->data;
struct dns_msg* msg = tomsg(env, &key->key, data, region, now,
scratch);
if(msg) {
lock_rw_unlock(&e->lock);
return msg;
}
/* could be msg==NULL; due to TTL or not all rrsets available */
lock_rw_unlock(&e->lock);
}
/* see if a DNAME exists. Checked for first, to enforce that DNAMEs
* are more important, the CNAME is resynthesized and thus
* consistent with the DNAME */
if( (rrset=find_closest_of_type(env, qname, qnamelen, qclass, now,
LDNS_RR_TYPE_DNAME, 1))) {
/* synthesize a DNAME+CNAME message based on this */
struct dns_msg* msg = synth_dname_msg(rrset, region, now, &k);
if(msg) {
lock_rw_unlock(&rrset->entry.lock);
return msg;
}
lock_rw_unlock(&rrset->entry.lock);
}
/* see if we have CNAME for this domain,
* but not for DS records (which are part of the parent) */
if( qtype != LDNS_RR_TYPE_DS &&
(rrset=rrset_cache_lookup(env->rrset_cache, qname, qnamelen,
LDNS_RR_TYPE_CNAME, qclass, 0, now, 0))) {
struct dns_msg* msg = rrset_msg(rrset, region, now, &k);
if(msg) {
lock_rw_unlock(&rrset->entry.lock);
return msg;
}
lock_rw_unlock(&rrset->entry.lock);
}
/* construct DS, DNSKEY, DLV messages from rrset cache. */
if((qtype == LDNS_RR_TYPE_DS || qtype == LDNS_RR_TYPE_DNSKEY ||
qtype == LDNS_RR_TYPE_DLV) &&
(rrset=rrset_cache_lookup(env->rrset_cache, qname, qnamelen,
qtype, qclass, 0, now, 0))) {
/* if the rrset is from the additional section, and the
* signatures have fallen off, then do not synthesize a msg
* instead, allow a full query for signed results to happen.
* Forego all rrset data from additional section, because
* some signatures may not be present and cause validation
* failure.
*/
struct packed_rrset_data *d = (struct packed_rrset_data*)
rrset->entry.data;
if(d->trust != rrset_trust_add_noAA &&
d->trust != rrset_trust_add_AA &&
(qtype == LDNS_RR_TYPE_DS ||
(d->trust != rrset_trust_auth_noAA
&& d->trust != rrset_trust_auth_AA) )) {
struct dns_msg* msg = rrset_msg(rrset, region, now, &k);
if(msg) {
lock_rw_unlock(&rrset->entry.lock);
return msg;
}
}
lock_rw_unlock(&rrset->entry.lock);
}
/* stop downwards cache search on NXDOMAIN.
* Empty nonterminals are NOERROR, so an NXDOMAIN for foo
* means bla.foo also does not exist. The DNSSEC proofs are
* the same. We search upwards for NXDOMAINs. */
if(env->cfg->harden_below_nxdomain)
while(!dname_is_root(k.qname)) {
dname_remove_label(&k.qname, &k.qname_len);
h = query_info_hash(&k, flags);
e = slabhash_lookup(env->msg_cache, h, &k, 0);
if(!e && k.qtype != LDNS_RR_TYPE_A &&
env->cfg->qname_minimisation) {
k.qtype = LDNS_RR_TYPE_A;
h = query_info_hash(&k, flags);
e = slabhash_lookup(env->msg_cache, h, &k, 0);
}
if(e) {
struct reply_info* data = (struct reply_info*)e->data;
struct dns_msg* msg;
if(FLAGS_GET_RCODE(data->flags) == LDNS_RCODE_NXDOMAIN
&& data->security == sec_status_secure
&& (msg=tomsg(env, &k, data, region, now, scratch))){
lock_rw_unlock(&e->lock);
msg->qinfo.qname=qname;
msg->qinfo.qname_len=qnamelen;
/* check that DNSSEC really works out */
msg->rep->security = sec_status_unchecked;
return msg;
}
lock_rw_unlock(&e->lock);
}
k.qtype = qtype;
}
/* fill common RR types for ANY response to avoid requery */
if(qtype == LDNS_RR_TYPE_ANY) {
return fill_any(env, qname, qnamelen, qtype, qclass, region);
}
return NULL;
}
int
dns_cache_store(struct module_env* env, struct query_info* msgqinf,
struct reply_info* msgrep, int is_referral, time_t leeway, int pside,
struct regional* region, uint16_t flags)
{
struct reply_info* rep = NULL;
/* alloc, malloc properly (not in region, like msg is) */
rep = reply_info_copy(msgrep, env->alloc, NULL);
if(!rep)
return 0;
/* ttl must be relative ;i.e. 0..86400 not time(0)+86400.
* the env->now is added to message and RRsets in this routine. */
/* the leeway is used to invalidate other rrsets earlier */
if(is_referral) {
/* store rrsets */
struct rrset_ref ref;
size_t i;
for(i=0; i<rep->rrset_count; i++) {
packed_rrset_ttl_add((struct packed_rrset_data*)
rep->rrsets[i]->entry.data, *env->now);
ref.key = rep->rrsets[i];
ref.id = rep->rrsets[i]->id;
/*ignore ret: it was in the cache, ref updated */
/* no leeway for typeNS */
(void)rrset_cache_update(env->rrset_cache, &ref,
env->alloc, *env->now +
((ntohs(ref.key->rk.type)==LDNS_RR_TYPE_NS
&& !pside) ? 0:leeway));
}
free(rep);
return 1;
} else {
/* store msg, and rrsets */
struct query_info qinf;
hashvalue_type h;
qinf = *msgqinf;
qinf.qname = memdup(msgqinf->qname, msgqinf->qname_len);
if(!qinf.qname) {
reply_info_parsedelete(rep, env->alloc);
return 0;
}
/* fixup flags to be sensible for a reply based on the cache */
/* this module means that RA is available. It is an answer QR.
* Not AA from cache. Not CD in cache (depends on client bit). */
rep->flags |= (BIT_RA | BIT_QR);
rep->flags &= ~(BIT_AA | BIT_CD);
h = query_info_hash(&qinf, flags);
dns_cache_store_msg(env, &qinf, h, rep, leeway, pside, msgrep,
region);
/* qname is used inside query_info_entrysetup, and set to
* NULL. If it has not been used, free it. free(0) is safe. */
free(qinf.qname);
}
return 1;
}
int
dns_cache_prefetch_adjust(struct module_env* env, struct query_info* qinfo,
time_t adjust, uint16_t flags)
{
struct msgreply_entry* msg;
msg = msg_cache_lookup(env, qinfo->qname, qinfo->qname_len,
qinfo->qtype, qinfo->qclass, flags, *env->now, 1);
if(msg) {
struct reply_info* rep = (struct reply_info*)msg->entry.data;
if(rep) {
rep->prefetch_ttl += adjust;
lock_rw_unlock(&msg->entry.lock);
return 1;
}
lock_rw_unlock(&msg->entry.lock);
}
return 0;
}