monero/external/unbound/services/cache/infra.c
2014-10-05 23:44:31 +02:00

569 lines
17 KiB
C

/*
* 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 "ldns/rrdef.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
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);
}
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;
return infra;
}
void
infra_delete(struct infra_cache* infra)
{
if(!infra)
return;
slabhash_delete(infra->hosts);
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;
maxmem = cfg->infra_cache_numhosts * (sizeof(struct infra_key)+
sizeof(struct infra_data)+INFRA_BYTES_NAME);
if(maxmem != slabhash_get_size(infra->hosts) ||
cfg->infra_cache_slabs != infra->hosts->size) {
infra_delete(infra);
infra = infra_create(cfg);
}
return infra;
}
/** calculate the hash value for a host key */
static hashvalue_t
hash_addr(struct sockaddr_storage* addr, socklen_t addrlen)
{
hashvalue_t 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);
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);
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_t
hash_infra(struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name)
{
return dname_query_hash(name, hash_addr(addr, addrlen));
}
/** 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;
}
size_t
infra_get_mem(struct infra_cache* infra)
{
return sizeof(*infra) + slabhash_get_mem(infra->hosts);
}