monero/external/unbound/services/cache/infra.h

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2014-10-05 21:44:31 +00:00
/*
* services/cache/infra.h - 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.
*/
#ifndef SERVICES_CACHE_INFRA_H
#define SERVICES_CACHE_INFRA_H
#include "util/storage/lruhash.h"
#include "util/rtt.h"
struct slabhash;
struct config_file;
/**
* Host information kept for every server, per zone.
*/
struct infra_key {
/** the host address. */
struct sockaddr_storage addr;
/** length of addr. */
socklen_t addrlen;
/** zone name in wireformat */
uint8_t* zonename;
/** length of zonename */
size_t namelen;
/** hash table entry, data of type infra_data. */
struct lruhash_entry entry;
};
/**
* Host information encompasses host capabilities and retransmission timeouts.
* And lameness information (notAuthoritative, noEDNS, Recursive)
*/
struct infra_data {
/** TTL value for this entry. absolute time. */
time_t ttl;
/** time in seconds (absolute) when probing re-commences, 0 disabled */
time_t probedelay;
/** round trip times for timeout calculation */
struct rtt_info rtt;
/** edns version that the host supports, -1 means no EDNS */
int edns_version;
/** if the EDNS lameness is already known or not.
* EDNS lame is when EDNS queries or replies are dropped,
* and cause a timeout */
uint8_t edns_lame_known;
/** is the host lame (does not serve the zone authoritatively),
* or is the host dnssec lame (does not serve DNSSEC data) */
uint8_t isdnsseclame;
/** is the host recursion lame (not AA, but RA) */
uint8_t rec_lame;
/** the host is lame (not authoritative) for A records */
uint8_t lame_type_A;
/** the host is lame (not authoritative) for other query types */
uint8_t lame_other;
/** timeouts counter for type A */
uint8_t timeout_A;
/** timeouts counter for type AAAA */
uint8_t timeout_AAAA;
/** timeouts counter for others */
uint8_t timeout_other;
};
/**
* Infra cache
*/
struct infra_cache {
/** The hash table with hosts */
struct slabhash* hosts;
/** TTL value for host information, in seconds */
int host_ttl;
};
/** infra host cache default hash lookup size */
#define INFRA_HOST_STARTSIZE 32
/** bytes per zonename reserved in the hostcache, dnamelen(zonename.com.) */
#define INFRA_BYTES_NAME 14
/**
* Create infra cache.
* @param cfg: config parameters or NULL for defaults.
* @return: new infra cache, or NULL.
*/
struct infra_cache* infra_create(struct config_file* cfg);
/**
* Delete infra cache.
* @param infra: infrastructure cache to delete.
*/
void infra_delete(struct infra_cache* infra);
/**
* Adjust infra cache to use updated configuration settings.
* This may clean the cache. Operates a bit like realloc.
* There may be no threading or use by other threads.
* @param infra: existing cache. If NULL a new infra cache is returned.
* @param cfg: config options.
* @return the new infra cache pointer or NULL on error.
*/
struct infra_cache* infra_adjust(struct infra_cache* infra,
struct config_file* cfg);
/**
* Plain find infra data function (used by the the other functions)
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: domain name of zone.
* @param namelen: length of domain name.
* @param wr: if true, writelock, else readlock.
* @return the entry, could be expired (this is not checked) or NULL.
*/
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);
/**
* Find host information to send a packet. Creates new entry if not found.
* Lameness is empty. EDNS is 0 (try with first), and rtt is returned for
* the first message to it.
* Use this to send a packet only, because it also locks out others when
* probing is restricted.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: domain name of zone.
* @param namelen: length of domain name.
* @param timenow: what time it is now.
* @param edns_vs: edns version it supports, is returned.
* @param edns_lame_known: if EDNS lame (EDNS is dropped in transit) has
* already been probed, is returned.
* @param to: timeout to use, is returned.
* @return: 0 on error.
*/
int infra_host(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* name, size_t namelen,
time_t timenow, int* edns_vs, uint8_t* edns_lame_known, int* to);
/**
* Set a host to be lame for the given zone.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: domain name of zone apex.
* @param namelen: length of domain name.
* @param timenow: what time it is now.
* @param dnsseclame: if true the host is set dnssec lame.
* if false, the host is marked lame (not serving the zone).
* @param reclame: if true host is a recursor not AA server.
* if false, dnsseclame or marked lame.
* @param qtype: the query type for which it is lame.
* @return: 0 on error.
*/
int infra_set_lame(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen,
uint8_t* name, size_t namelen, time_t timenow, int dnsseclame,
int reclame, uint16_t qtype);
/**
* Update rtt information for the host.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: zone name
* @param namelen: zone name length
* @param qtype: query type.
* @param roundtrip: estimate of roundtrip time in milliseconds or -1 for
* timeout.
* @param orig_rtt: original rtt for the query that timed out (roundtrip==-1).
* ignored if roundtrip != -1.
* @param timenow: what time it is now.
* @return: 0 on error. new rto otherwise.
*/
int infra_rtt_update(struct infra_cache* infra, struct sockaddr_storage* addr,
socklen_t addrlen, uint8_t* name, size_t namelen, int qtype,
int roundtrip, int orig_rtt, time_t timenow);
/**
* Update information for the host, store that a TCP transaction works.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: name of zone
* @param namelen: length of name
*/
void infra_update_tcp_works(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen,
uint8_t* name, size_t namelen);
/**
* Update edns information for the host.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: name of zone
* @param namelen: length of name
* @param edns_version: the version that it publishes.
* If it is known to support EDNS then no-EDNS is not stored over it.
* @param timenow: what time it is now.
* @return: 0 on error.
*/
int infra_edns_update(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen,
uint8_t* name, size_t namelen, int edns_version, time_t timenow);
/**
* Get Lameness information and average RTT if host is in the cache.
* This information is to be used for server selection.
* @param infra: infrastructure cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: zone name.
* @param namelen: zone name length.
* @param qtype: the query to be made.
* @param lame: if function returns true, this returns lameness of the zone.
* @param dnsseclame: if function returns true, this returns if the zone
* is dnssec-lame.
* @param reclame: if function returns true, this is if it is recursion lame.
* @param rtt: if function returns true, this returns avg rtt of the server.
* The rtt value is unclamped and reflects recent timeouts.
* @param timenow: what time it is now.
* @return if found in cache, or false if not (or TTL bad).
*/
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);
/**
* Get additional (debug) info on timing.
* @param infra: infra cache.
* @param addr: host address.
* @param addrlen: length of addr.
* @param name: zone name
* @param namelen: zone name length
* @param rtt: the rtt_info is copied into here (caller alloced return struct).
* @param delay: probe delay (if any).
* @param timenow: what time it is now.
* @param tA: timeout counter on type A.
* @param tAAAA: timeout counter on type AAAA.
* @param tother: timeout counter on type other.
* @return TTL the infra host element is valid for. If -1: not found in cache.
* TTL -2: found but expired.
*/
long long infra_get_host_rto(struct infra_cache* infra,
struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* name,
size_t namelen, struct rtt_info* rtt, int* delay, time_t timenow,
int* tA, int* tAAAA, int* tother);
/**
* Get memory used by the infra cache.
* @param infra: infrastructure cache.
* @return memory in use in bytes.
*/
size_t infra_get_mem(struct infra_cache* infra);
/** calculate size for the hashtable, does not count size of lameness,
* so the hashtable is a fixed number of items */
size_t infra_sizefunc(void* k, void* d);
/** compare two addresses, returns -1, 0, or +1 */
int infra_compfunc(void* key1, void* key2);
/** delete key, and destroy the lock */
void infra_delkeyfunc(void* k, void* arg);
/** delete data and destroy the lameness hashtable */
void infra_deldatafunc(void* d, void* arg);
#endif /* SERVICES_CACHE_INFRA_H */