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/*
* services/cache/infra.c - infrastructure cache, server rtt and capabilities
*
* 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 infrastructure cache.
*/
#include "config.h"
#include "sldns/rrdef.h"
#include "sldns/str2wire.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "services/cache/infra.h"
#include "util/storage/slabhash.h"
#include "util/storage/lookup3.h"
#include "util/data/dname.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/config_file.h"
#include "iterator/iterator.h"
/** Timeout when only a single probe query per IP is allowed. */
#define PROBE_MAXRTO 12000 /* in msec */
/** number of timeouts for a type when the domain can be blocked ;
* even if another type has completely rtt maxed it, the different type
* can do this number of packets (until those all timeout too) */
#define TIMEOUT_COUNT_MAX 3
/** ratelimit value for delegation point */
int infra_dp_ratelimit = 0;
/** ratelimit value for client ip addresses,
* in queries per second. */
int infra_ip_ratelimit = 0;
size_t
infra_sizefunc(void* k, void* ATTR_UNUSED(d))
{
struct infra_key* key = (struct infra_key*)k;
return sizeof(*key) + sizeof(struct infra_data) + key->namelen
+ lock_get_mem(&key->entry.lock);
}
int
infra_compfunc(void* key1, void* key2)
{
struct infra_key* k1 = (struct infra_key*)key1;
struct infra_key* k2 = (struct infra_key*)key2;
int r = sockaddr_cmp(&k1->addr, k1->addrlen, &k2->addr, k2->addrlen);
if(r != 0)
return r;
if(k1->namelen != k2->namelen) {
if(k1->namelen < k2->namelen)
return -1;
return 1;
}
return query_dname_compare(k1->zonename, k2->zonename);
}
void
infra_delkeyfunc(void* k, void* ATTR_UNUSED(arg))
{
struct infra_key* key = (struct infra_key*)k;
if(!key)
return;
lock_rw_destroy(&key->entry.lock);
free(key->zonename);
free(key);
}
void
infra_deldatafunc(void* d, void* ATTR_UNUSED(arg))
{
struct infra_data* data = (struct infra_data*)d;
free(data);
}
size_t
rate_sizefunc(void* k, void* ATTR_UNUSED(d))
{
struct rate_key* key = (struct rate_key*)k;
return sizeof(*key) + sizeof(struct rate_data) + key->namelen
+ lock_get_mem(&key->entry.lock);
}
int
rate_compfunc(void* key1, void* key2)
{
struct rate_key* k1 = (struct rate_key*)key1;
struct rate_key* k2 = (struct rate_key*)key2;
if(k1->namelen != k2->namelen) {
if(k1->namelen < k2->namelen)
return -1;
return 1;
}
return query_dname_compare(k1->name, k2->name);
}
void
rate_delkeyfunc(void* k, void* ATTR_UNUSED(arg))
{
struct rate_key* key = (struct rate_key*)k;
if(!key)
return;
lock_rw_destroy(&key->entry.lock);
free(key->name);
free(key);
}
void
rate_deldatafunc(void* d, void* ATTR_UNUSED(arg))
{
struct rate_data* data = (struct rate_data*)d;
free(data);
}
/** find or create element in domainlimit tree */
static struct domain_limit_data* domain_limit_findcreate(
struct infra_cache* infra, char* name)
{
uint8_t* nm;
int labs;
size_t nmlen;
struct domain_limit_data* d;
/* parse name */
nm = sldns_str2wire_dname(name, &nmlen);
if(!nm) {
log_err("could not parse %s", name);
return NULL;
}
labs = dname_count_labels(nm);
/* can we find it? */
d = (struct domain_limit_data*)name_tree_find(&infra->domain_limits,
nm, nmlen, labs, LDNS_RR_CLASS_IN);
if(d) {
free(nm);
return d;
}
/* create it */
d = (struct domain_limit_data*)calloc(1, sizeof(*d));
if(!d) {
free(nm);
return NULL;
}
d->node.node.key = &d->node;
d->node.name = nm;
d->node.len = nmlen;
d->node.labs = labs;
d->node.dclass = LDNS_RR_CLASS_IN;
d->lim = -1;
d->below = -1;
if(!name_tree_insert(&infra->domain_limits, &d->node, nm, nmlen,
labs, LDNS_RR_CLASS_IN)) {
log_err("duplicate element in domainlimit tree");
free(nm);
free(d);
return NULL;
}
return d;
}
/** insert rate limit configuration into lookup tree */
static int infra_ratelimit_cfg_insert(struct infra_cache* infra,
struct config_file* cfg)
{
struct config_str2list* p;
struct domain_limit_data* d;
for(p = cfg->ratelimit_for_domain; p; p = p->next) {
d = domain_limit_findcreate(infra, p->str);
if(!d)
return 0;
d->lim = atoi(p->str2);
}
for(p = cfg->ratelimit_below_domain; p; p = p->next) {
d = domain_limit_findcreate(infra, p->str);
if(!d)
return 0;
d->below = atoi(p->str2);
}
return 1;
}
/** setup domain limits tree (0 on failure) */
static int
setup_domain_limits(struct infra_cache* infra, struct config_file* cfg)
{
name_tree_init(&infra->domain_limits);
if(!infra_ratelimit_cfg_insert(infra, cfg)) {
return 0;
}
name_tree_init_parents(&infra->domain_limits);
return 1;
}
struct infra_cache*
infra_create(struct config_file* cfg)
{
struct infra_cache* infra = (struct infra_cache*)calloc(1,
sizeof(struct infra_cache));
size_t maxmem = cfg->infra_cache_numhosts * (sizeof(struct infra_key)+
sizeof(struct infra_data)+INFRA_BYTES_NAME);
infra->hosts = slabhash_create(cfg->infra_cache_slabs,
INFRA_HOST_STARTSIZE, maxmem, &infra_sizefunc, &infra_compfunc,
&infra_delkeyfunc, &infra_deldatafunc, NULL);
if(!infra->hosts) {
free(infra);
return NULL;
}
infra->host_ttl = cfg->host_ttl;
infra_dp_ratelimit = cfg->ratelimit;
infra->domain_rates = slabhash_create(cfg->ratelimit_slabs,
INFRA_HOST_STARTSIZE, cfg->ratelimit_size,
&rate_sizefunc, &rate_compfunc, &rate_delkeyfunc,
&rate_deldatafunc, NULL);
if(!infra->domain_rates) {
infra_delete(infra);
return NULL;
}
/* insert config data into ratelimits */
if(!setup_domain_limits(infra, cfg)) {
infra_delete(infra);
return NULL;
}
infra_ip_ratelimit = cfg->ip_ratelimit;
infra->client_ip_rates = slabhash_create(cfg->ip_ratelimit_slabs,
INFRA_HOST_STARTSIZE, cfg->ip_ratelimit_size, &ip_rate_sizefunc,
&ip_rate_compfunc, &ip_rate_delkeyfunc, &ip_rate_deldatafunc, NULL);
if(!infra->client_ip_rates) {
infra_delete(infra);
return NULL;
}
return infra;
}
/** delete domain_limit entries */
static void domain_limit_free(rbnode_type* n, void* ATTR_UNUSED(arg))
{
if(n) {
free(((struct domain_limit_data*)n)->node.name);
free(n);
}
}
void
infra_delete(struct infra_cache* infra)
{
if(!infra)
return;
slabhash_delete(infra->hosts);
slabhash_delete(infra->domain_rates);
traverse_postorder(&infra->domain_limits, domain_limit_free, NULL);
slabhash_delete(infra->client_ip_rates);
free(infra);
}
struct infra_cache*
infra_adjust(struct infra_cache* infra, struct config_file* cfg)
{
size_t maxmem;
if(!infra)
return infra_create(cfg);
infra->host_ttl = cfg->host_ttl;
infra_dp_ratelimit = cfg->ratelimit;
infra_ip_ratelimit = cfg->ip_ratelimit;
maxmem = cfg->infra_cache_numhosts * (sizeof(struct infra_key)+
sizeof(struct infra_data)+INFRA_BYTES_NAME);
/* divide cachesize by slabs and multiply by slabs, because if the
* cachesize is not an even multiple of slabs, that is the resulting
* size of the slabhash */
if(!slabhash_is_size(infra->hosts, maxmem, cfg->infra_cache_slabs) ||
!slabhash_is_size(infra->domain_rates, cfg->ratelimit_size,
cfg->ratelimit_slabs) ||
!slabhash_is_size(infra->client_ip_rates, cfg->ip_ratelimit_size,
cfg->ip_ratelimit_slabs)) {
infra_delete(infra);
infra = infra_create(cfg);
} else {
/* reapply domain limits */
traverse_postorder(&infra->domain_limits, domain_limit_free,
NULL);
if(!setup_domain_limits(infra, cfg)) {
infra_delete(infra);
return NULL;
}
}
return infra;
}
/** calculate the hash value for a host key
* set use_port to a non-0 number to use the port in
* the hash calculation; 0 to ignore the port.*/
static hashvalue_type
hash_addr(struct sockaddr_storage* addr, socklen_t addrlen,
int use_port)
{
hashvalue_type h = 0xab;
/* select the pieces to hash, some OS have changing data inside */
if(addr_is_ip6(addr, addrlen)) {
struct sockaddr_in6* in6 = (struct sockaddr_in6*)addr;
h = hashlittle(&in6->sin6_family, sizeof(in6->sin6_family), h);
if(use_port){
h = hashlittle(&in6->sin6_port, sizeof(in6->sin6_port), h);
}
h = hashlittle(&in6->sin6_addr, INET6_SIZE, h);
} else {
struct sockaddr_in* in = (struct sockaddr_in*)addr;
h = hashlittle(&in->sin_family, sizeof(in->sin_family), h);
if(use_port){
h = hashlittle(&in->sin_port, sizeof(in->sin_port), h);
}
h = hashlittle(&in->sin_addr, INET_SIZE, h);
}
return h;
}
/** calculate infra hash for a key */
static hashvalue_type
hash_infra(struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name)
{
return dname_query_hash(name, hash_addr(addr, addrlen, 1));
}
/** lookup version that does not check host ttl (you check it) */
struct lruhash_entry*
infra_lookup_nottl(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* name, size_t namelen, int wr)
{
struct infra_key k;
k.addrlen = addrlen;
memcpy(&k.addr, addr, addrlen);
k.namelen = namelen;
k.zonename = name;
k.entry.hash = hash_infra(addr, addrlen, name);
k.entry.key = (void*)&k;
k.entry.data = NULL;
return slabhash_lookup(infra->hosts, k.entry.hash, &k, wr);
}
/** init the data elements */
static void
data_entry_init(struct infra_cache* infra, struct lruhash_entry* e,
time_t timenow)
{
struct infra_data* data = (struct infra_data*)e->data;
data->ttl = timenow + infra->host_ttl;
rtt_init(&data->rtt);
data->edns_version = 0;
data->edns_lame_known = 0;
data->probedelay = 0;
data->isdnsseclame = 0;
data->rec_lame = 0;
data->lame_type_A = 0;
data->lame_other = 0;
data->timeout_A = 0;
data->timeout_AAAA = 0;
data->timeout_other = 0;
}
/**
* Create and init a new entry for a host
* @param infra: infra structure with config parameters.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: name of zone
* @param namelen: length of name.
* @param tm: time now.
* @return: the new entry or NULL on malloc failure.
*/
static struct lruhash_entry*
new_entry(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* name, size_t namelen, time_t tm)
{
struct infra_data* data;
struct infra_key* key = (struct infra_key*)malloc(sizeof(*key));
if(!key)
return NULL;
data = (struct infra_data*)malloc(sizeof(struct infra_data));
if(!data) {
free(key);
return NULL;
}
key->zonename = memdup(name, namelen);
if(!key->zonename) {
free(key);
free(data);
return NULL;
}
key->namelen = namelen;
lock_rw_init(&key->entry.lock);
key->entry.hash = hash_infra(addr, addrlen, name);
key->entry.key = (void*)key;
key->entry.data = (void*)data;
key->addrlen = addrlen;
memcpy(&key->addr, addr, addrlen);
data_entry_init(infra, &key->entry, tm);
return &key->entry;
}
int
infra_host(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* nm, size_t nmlen, time_t timenow,
int* edns_vs, uint8_t* edns_lame_known, int* to)
{
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
nm, nmlen, 0);
struct infra_data* data;
int wr = 0;
if(e && ((struct infra_data*)e->data)->ttl < timenow) {
/* it expired, try to reuse existing entry */
int old = ((struct infra_data*)e->data)->rtt.rto;
uint8_t tA = ((struct infra_data*)e->data)->timeout_A;
uint8_t tAAAA = ((struct infra_data*)e->data)->timeout_AAAA;
uint8_t tother = ((struct infra_data*)e->data)->timeout_other;
lock_rw_unlock(&e->lock);
e = infra_lookup_nottl(infra, addr, addrlen, nm, nmlen, 1);
if(e) {
/* if its still there we have a writelock, init */
/* re-initialise */
/* do not touch lameness, it may be valid still */
data_entry_init(infra, e, timenow);
wr = 1;
/* TOP_TIMEOUT remains on reuse */
if(old >= USEFUL_SERVER_TOP_TIMEOUT) {
((struct infra_data*)e->data)->rtt.rto
= USEFUL_SERVER_TOP_TIMEOUT;
((struct infra_data*)e->data)->timeout_A = tA;
((struct infra_data*)e->data)->timeout_AAAA = tAAAA;
((struct infra_data*)e->data)->timeout_other = tother;
}
}
}
if(!e) {
/* insert new entry */
if(!(e = new_entry(infra, addr, addrlen, nm, nmlen, timenow)))
return 0;
data = (struct infra_data*)e->data;
*edns_vs = data->edns_version;
*edns_lame_known = data->edns_lame_known;
*to = rtt_timeout(&data->rtt);
slabhash_insert(infra->hosts, e->hash, e, data, NULL);
return 1;
}
/* use existing entry */
data = (struct infra_data*)e->data;
*edns_vs = data->edns_version;
*edns_lame_known = data->edns_lame_known;
*to = rtt_timeout(&data->rtt);
if(*to >= PROBE_MAXRTO && rtt_notimeout(&data->rtt)*4 <= *to) {
/* delay other queries, this is the probe query */
if(!wr) {
lock_rw_unlock(&e->lock);
e = infra_lookup_nottl(infra, addr,addrlen,nm,nmlen, 1);
if(!e) { /* flushed from cache real fast, no use to
allocate just for the probedelay */
return 1;
}
data = (struct infra_data*)e->data;
}
/* add 999 to round up the timeout value from msec to sec,
* then add a whole second so it is certain that this probe
* has timed out before the next is allowed */
data->probedelay = timenow + ((*to)+1999)/1000;
}
lock_rw_unlock(&e->lock);
return 1;
}
int
infra_set_lame(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* nm, size_t nmlen, time_t timenow,
int dnsseclame, int reclame, uint16_t qtype)
{
struct infra_data* data;
struct lruhash_entry* e;
int needtoinsert = 0;
e = infra_lookup_nottl(infra, addr, addrlen, nm, nmlen, 1);
if(!e) {
/* insert it */
if(!(e = new_entry(infra, addr, addrlen, nm, nmlen, timenow))) {
log_err("set_lame: malloc failure");
return 0;
}
needtoinsert = 1;
} else if( ((struct infra_data*)e->data)->ttl < timenow) {
/* expired, reuse existing entry */
data_entry_init(infra, e, timenow);
}
/* got an entry, now set the zone lame */
data = (struct infra_data*)e->data;
/* merge data (if any) */
if(dnsseclame)
data->isdnsseclame = 1;
if(reclame)
data->rec_lame = 1;
if(!dnsseclame && !reclame && qtype == LDNS_RR_TYPE_A)
data->lame_type_A = 1;
if(!dnsseclame && !reclame && qtype != LDNS_RR_TYPE_A)
data->lame_other = 1;
/* done */
if(needtoinsert)
slabhash_insert(infra->hosts, e->hash, e, e->data, NULL);
else { lock_rw_unlock(&e->lock); }
return 1;
}
void
infra_update_tcp_works(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* nm,
size_t nmlen)
{
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
nm, nmlen, 1);
struct infra_data* data;
if(!e)
return; /* doesn't exist */
data = (struct infra_data*)e->data;
if(data->rtt.rto >= RTT_MAX_TIMEOUT)
/* do not disqualify this server altogether, it is better
* than nothing */
data->rtt.rto = RTT_MAX_TIMEOUT-1000;
lock_rw_unlock(&e->lock);
}
int
infra_rtt_update(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* nm, size_t nmlen, int qtype,
int roundtrip, int orig_rtt, time_t timenow)
{
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
nm, nmlen, 1);
struct infra_data* data;
int needtoinsert = 0;
int rto = 1;
if(!e) {
if(!(e = new_entry(infra, addr, addrlen, nm, nmlen, timenow)))
return 0;
needtoinsert = 1;
} else if(((struct infra_data*)e->data)->ttl < timenow) {
data_entry_init(infra, e, timenow);
}
/* have an entry, update the rtt */
data = (struct infra_data*)e->data;
if(roundtrip == -1) {
rtt_lost(&data->rtt, orig_rtt);
if(qtype == LDNS_RR_TYPE_A) {
if(data->timeout_A < TIMEOUT_COUNT_MAX)
data->timeout_A++;
} else if(qtype == LDNS_RR_TYPE_AAAA) {
if(data->timeout_AAAA < TIMEOUT_COUNT_MAX)
data->timeout_AAAA++;
} else {
if(data->timeout_other < TIMEOUT_COUNT_MAX)
data->timeout_other++;
}
} else {
/* if we got a reply, but the old timeout was above server
* selection height, delete the timeout so the server is
* fully available again */
if(rtt_unclamped(&data->rtt) >= USEFUL_SERVER_TOP_TIMEOUT)
rtt_init(&data->rtt);
rtt_update(&data->rtt, roundtrip);
data->probedelay = 0;
if(qtype == LDNS_RR_TYPE_A)
data->timeout_A = 0;
else if(qtype == LDNS_RR_TYPE_AAAA)
data->timeout_AAAA = 0;
else data->timeout_other = 0;
}
if(data->rtt.rto > 0)
rto = data->rtt.rto;
if(needtoinsert)
slabhash_insert(infra->hosts, e->hash, e, e->data, NULL);
else { lock_rw_unlock(&e->lock); }
return rto;
}
long long infra_get_host_rto(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* nm,
size_t nmlen, struct rtt_info* rtt, int* delay, time_t timenow,
int* tA, int* tAAAA, int* tother)
{
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
nm, nmlen, 0);
struct infra_data* data;
long long ttl = -2;
if(!e) return -1;
data = (struct infra_data*)e->data;
if(data->ttl >= timenow) {
ttl = (long long)(data->ttl - timenow);
memmove(rtt, &data->rtt, sizeof(*rtt));
if(timenow < data->probedelay)
*delay = (int)(data->probedelay - timenow);
else *delay = 0;
}
*tA = (int)data->timeout_A;
*tAAAA = (int)data->timeout_AAAA;
*tother = (int)data->timeout_other;
lock_rw_unlock(&e->lock);
return ttl;
}
int
infra_edns_update(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* nm, size_t nmlen, int edns_version,
time_t timenow)
{
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
nm, nmlen, 1);
struct infra_data* data;
int needtoinsert = 0;
if(!e) {
if(!(e = new_entry(infra, addr, addrlen, nm, nmlen, timenow)))
return 0;
needtoinsert = 1;
} else if(((struct infra_data*)e->data)->ttl < timenow) {
data_entry_init(infra, e, timenow);
}
/* have an entry, update the rtt, and the ttl */
data = (struct infra_data*)e->data;
/* do not update if noEDNS and stored is yesEDNS */
if(!(edns_version == -1 && (data->edns_version != -1 &&
data->edns_lame_known))) {
data->edns_version = edns_version;
data->edns_lame_known = 1;
}
if(needtoinsert)
slabhash_insert(infra->hosts, e->hash, e, e->data, NULL);
else { lock_rw_unlock(&e->lock); }
return 1;
}
int
infra_get_lame_rtt(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen,
uint8_t* name, size_t namelen, uint16_t qtype,
int* lame, int* dnsseclame, int* reclame, int* rtt, time_t timenow)
{
struct infra_data* host;
struct lruhash_entry* e = infra_lookup_nottl(infra, addr, addrlen,
name, namelen, 0);
if(!e)
return 0;
host = (struct infra_data*)e->data;
*rtt = rtt_unclamped(&host->rtt);
if(host->rtt.rto >= PROBE_MAXRTO && timenow < host->probedelay
&& rtt_notimeout(&host->rtt)*4 <= host->rtt.rto) {
/* single probe for this domain, and we are not probing */
/* unless the query type allows a probe to happen */
if(qtype == LDNS_RR_TYPE_A) {
if(host->timeout_A >= TIMEOUT_COUNT_MAX)
*rtt = USEFUL_SERVER_TOP_TIMEOUT;
else *rtt = USEFUL_SERVER_TOP_TIMEOUT-1000;
} else if(qtype == LDNS_RR_TYPE_AAAA) {
if(host->timeout_AAAA >= TIMEOUT_COUNT_MAX)
*rtt = USEFUL_SERVER_TOP_TIMEOUT;
else *rtt = USEFUL_SERVER_TOP_TIMEOUT-1000;
} else {
if(host->timeout_other >= TIMEOUT_COUNT_MAX)
*rtt = USEFUL_SERVER_TOP_TIMEOUT;
else *rtt = USEFUL_SERVER_TOP_TIMEOUT-1000;
}
}
if(timenow > host->ttl) {
/* expired entry */
/* see if this can be a re-probe of an unresponsive server */
/* minus 1000 because that is outside of the RTTBAND, so
* blacklisted servers stay blacklisted if this is chosen */
if(host->rtt.rto >= USEFUL_SERVER_TOP_TIMEOUT) {
lock_rw_unlock(&e->lock);
*rtt = USEFUL_SERVER_TOP_TIMEOUT-1000;
*lame = 0;
*dnsseclame = 0;
*reclame = 0;
return 1;
}
lock_rw_unlock(&e->lock);
return 0;
}
/* check lameness first */
if(host->lame_type_A && qtype == LDNS_RR_TYPE_A) {
lock_rw_unlock(&e->lock);
*lame = 1;
*dnsseclame = 0;
*reclame = 0;
return 1;
} else if(host->lame_other && qtype != LDNS_RR_TYPE_A) {
lock_rw_unlock(&e->lock);
*lame = 1;
*dnsseclame = 0;
*reclame = 0;
return 1;
} else if(host->isdnsseclame) {
lock_rw_unlock(&e->lock);
*lame = 0;
*dnsseclame = 1;
*reclame = 0;
return 1;
} else if(host->rec_lame) {
lock_rw_unlock(&e->lock);
*lame = 0;
*dnsseclame = 0;
*reclame = 1;
return 1;
}
/* no lameness for this type of query */
lock_rw_unlock(&e->lock);
*lame = 0;
*dnsseclame = 0;
*reclame = 0;
return 1;
}
int infra_find_ratelimit(struct infra_cache* infra, uint8_t* name,
size_t namelen)
{
int labs = dname_count_labels(name);
struct domain_limit_data* d = (struct domain_limit_data*)
name_tree_lookup(&infra->domain_limits, name, namelen, labs,
LDNS_RR_CLASS_IN);
if(!d) return infra_dp_ratelimit;
if(d->node.labs == labs && d->lim != -1)
return d->lim; /* exact match */
/* find 'below match' */
if(d->node.labs == labs)
d = (struct domain_limit_data*)d->node.parent;
while(d) {
if(d->below != -1)
return d->below;
d = (struct domain_limit_data*)d->node.parent;
}
return infra_dp_ratelimit;
}
size_t ip_rate_sizefunc(void* k, void* ATTR_UNUSED(d))
{
struct ip_rate_key* key = (struct ip_rate_key*)k;
return sizeof(*key) + sizeof(struct ip_rate_data)
+ lock_get_mem(&key->entry.lock);
}
int ip_rate_compfunc(void* key1, void* key2)
{
struct ip_rate_key* k1 = (struct ip_rate_key*)key1;
struct ip_rate_key* k2 = (struct ip_rate_key*)key2;
return sockaddr_cmp_addr(&k1->addr, k1->addrlen,
&k2->addr, k2->addrlen);
}
void ip_rate_delkeyfunc(void* k, void* ATTR_UNUSED(arg))
{
struct ip_rate_key* key = (struct ip_rate_key*)k;
if(!key)
return;
lock_rw_destroy(&key->entry.lock);
free(key);
}
/** find data item in array, for write access, caller unlocks */
static struct lruhash_entry* infra_find_ratedata(struct infra_cache* infra,
uint8_t* name, size_t namelen, int wr)
{
struct rate_key key;
hashvalue_type h = dname_query_hash(name, 0xab);
memset(&key, 0, sizeof(key));
key.name = name;
key.namelen = namelen;
key.entry.hash = h;
return slabhash_lookup(infra->domain_rates, h, &key, wr);
}
/** find data item in array for ip addresses */
static struct lruhash_entry* infra_find_ip_ratedata(struct infra_cache* infra,
struct comm_reply* repinfo, int wr)
{
struct ip_rate_key key;
hashvalue_type h = hash_addr(&(repinfo->addr),
repinfo->addrlen, 0);
memset(&key, 0, sizeof(key));
key.addr = repinfo->addr;
key.addrlen = repinfo->addrlen;
key.entry.hash = h;
return slabhash_lookup(infra->client_ip_rates, h, &key, wr);
}
/** create rate data item for name, number 1 in now */
static void infra_create_ratedata(struct infra_cache* infra,
uint8_t* name, size_t namelen, time_t timenow)
{
hashvalue_type h = dname_query_hash(name, 0xab);
struct rate_key* k = (struct rate_key*)calloc(1, sizeof(*k));
struct rate_data* d = (struct rate_data*)calloc(1, sizeof(*d));
if(!k || !d) {
free(k);
free(d);
return; /* alloc failure */
}
k->namelen = namelen;
k->name = memdup(name, namelen);
if(!k->name) {
free(k);
free(d);
return; /* alloc failure */
}
lock_rw_init(&k->entry.lock);
k->entry.hash = h;
k->entry.key = k;
k->entry.data = d;
d->qps[0] = 1;
d->timestamp[0] = timenow;
slabhash_insert(infra->domain_rates, h, &k->entry, d, NULL);
}
/** create rate data item for ip address */
static void infra_ip_create_ratedata(struct infra_cache* infra,
struct comm_reply* repinfo, time_t timenow)
{
hashvalue_type h = hash_addr(&(repinfo->addr),
repinfo->addrlen, 0);
struct ip_rate_key* k = (struct ip_rate_key*)calloc(1, sizeof(*k));
struct ip_rate_data* d = (struct ip_rate_data*)calloc(1, sizeof(*d));
if(!k || !d) {
free(k);
free(d);
return; /* alloc failure */
}
k->addr = repinfo->addr;
k->addrlen = repinfo->addrlen;
lock_rw_init(&k->entry.lock);
k->entry.hash = h;
k->entry.key = k;
k->entry.data = d;
d->qps[0] = 1;
d->timestamp[0] = timenow;
slabhash_insert(infra->client_ip_rates, h, &k->entry, d, NULL);
}
/** find the second and return its rate counter, if none, remove oldest */
static int* infra_rate_find_second(void* data, time_t t)
{
struct rate_data* d = (struct rate_data*)data;
int i, oldest;
for(i=0; i<RATE_WINDOW; i++) {
if(d->timestamp[i] == t)
return &(d->qps[i]);
}
/* remove oldest timestamp, and insert it at t with 0 qps */
oldest = 0;
for(i=0; i<RATE_WINDOW; i++) {
if(d->timestamp[i] < d->timestamp[oldest])
oldest = i;
}
d->timestamp[oldest] = t;
d->qps[oldest] = 0;
return &(d->qps[oldest]);
}
int infra_rate_max(void* data, time_t now)
{
struct rate_data* d = (struct rate_data*)data;
int i, max = 0;
for(i=0; i<RATE_WINDOW; i++) {
if(now-d->timestamp[i] <= RATE_WINDOW) {
if(d->qps[i] > max)
max = d->qps[i];
}
}
return max;
}
int infra_ratelimit_inc(struct infra_cache* infra, uint8_t* name,
size_t namelen, time_t timenow, struct query_info* qinfo,
struct comm_reply* replylist)
{
int lim, max;
struct lruhash_entry* entry;
if(!infra_dp_ratelimit)
return 1; /* not enabled */
/* find ratelimit */
lim = infra_find_ratelimit(infra, name, namelen);
if(!lim)
return 1; /* disabled for this domain */
/* find or insert ratedata */
entry = infra_find_ratedata(infra, name, namelen, 1);
if(entry) {
int premax = infra_rate_max(entry->data, timenow);
int* cur = infra_rate_find_second(entry->data, timenow);
(*cur)++;
max = infra_rate_max(entry->data, timenow);
lock_rw_unlock(&entry->lock);
if(premax < lim && max >= lim) {
char buf[257], qnm[257], ts[12], cs[12], ip[128];
dname_str(name, buf);
dname_str(qinfo->qname, qnm);
sldns_wire2str_type_buf(qinfo->qtype, ts, sizeof(ts));
sldns_wire2str_class_buf(qinfo->qclass, cs, sizeof(cs));
ip[0]=0;
if(replylist) {
addr_to_str((struct sockaddr_storage *)&replylist->addr,
replylist->addrlen, ip, sizeof(ip));
verbose(VERB_OPS, "ratelimit exceeded %s %d query %s %s %s from %s", buf, lim, qnm, cs, ts, ip);
} else {
verbose(VERB_OPS, "ratelimit exceeded %s %d query %s %s %s", buf, lim, qnm, cs, ts);
}
}
return (max < lim);
}
/* create */
infra_create_ratedata(infra, name, namelen, timenow);
return (1 < lim);
}
void infra_ratelimit_dec(struct infra_cache* infra, uint8_t* name,
size_t namelen, time_t timenow)
{
struct lruhash_entry* entry;
int* cur;
if(!infra_dp_ratelimit)
return; /* not enabled */
entry = infra_find_ratedata(infra, name, namelen, 1);
if(!entry) return; /* not cached */
cur = infra_rate_find_second(entry->data, timenow);
if((*cur) > 0)
(*cur)--;
lock_rw_unlock(&entry->lock);
}
int infra_ratelimit_exceeded(struct infra_cache* infra, uint8_t* name,
size_t namelen, time_t timenow)
{
struct lruhash_entry* entry;
int lim, max;
if(!infra_dp_ratelimit)
return 0; /* not enabled */
/* find ratelimit */
lim = infra_find_ratelimit(infra, name, namelen);
if(!lim)
return 0; /* disabled for this domain */
/* find current rate */
entry = infra_find_ratedata(infra, name, namelen, 0);
if(!entry)
return 0; /* not cached */
max = infra_rate_max(entry->data, timenow);
lock_rw_unlock(&entry->lock);
return (max >= lim);
}
size_t
infra_get_mem(struct infra_cache* infra)
{
size_t s = sizeof(*infra) + slabhash_get_mem(infra->hosts);
if(infra->domain_rates) s += slabhash_get_mem(infra->domain_rates);
if(infra->client_ip_rates) s += slabhash_get_mem(infra->client_ip_rates);
/* ignore domain_limits because walk through tree is big */
return s;
}
int infra_ip_ratelimit_inc(struct infra_cache* infra,
struct comm_reply* repinfo, time_t timenow, struct sldns_buffer* buffer)
{
int max;
struct lruhash_entry* entry;
/* not enabled */
if(!infra_ip_ratelimit) {
return 1;
}
/* find or insert ratedata */
entry = infra_find_ip_ratedata(infra, repinfo, 1);
if(entry) {
int premax = infra_rate_max(entry->data, timenow);
int* cur = infra_rate_find_second(entry->data, timenow);
(*cur)++;
max = infra_rate_max(entry->data, timenow);
lock_rw_unlock(&entry->lock);
if(premax < infra_ip_ratelimit && max >= infra_ip_ratelimit) {
char client_ip[128], qnm[LDNS_MAX_DOMAINLEN+1+12+12];
addr_to_str((struct sockaddr_storage *)&repinfo->addr,
repinfo->addrlen, client_ip, sizeof(client_ip));
qnm[0]=0;
if(sldns_buffer_limit(buffer)>LDNS_HEADER_SIZE &&
LDNS_QDCOUNT(sldns_buffer_begin(buffer))!=0) {
(void)sldns_wire2str_rrquestion_buf(
sldns_buffer_at(buffer, LDNS_HEADER_SIZE),
sldns_buffer_limit(buffer)-LDNS_HEADER_SIZE,
qnm, sizeof(qnm));
if(strlen(qnm)>0 && qnm[strlen(qnm)-1]=='\n')
qnm[strlen(qnm)-1] = 0; /*remove newline*/
if(strchr(qnm, '\t'))
*strchr(qnm, '\t') = ' ';
if(strchr(qnm, '\t'))
*strchr(qnm, '\t') = ' ';
verbose(VERB_OPS, "ip_ratelimit exceeded %s %d %s",
client_ip, infra_ip_ratelimit, qnm);
} else {
verbose(VERB_OPS, "ip_ratelimit exceeded %s %d (no query name)",
client_ip, infra_ip_ratelimit);
}
}
return (max <= infra_ip_ratelimit);
}
/* create */
infra_ip_create_ratedata(infra, repinfo, timenow);
return 1;
}
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