This file contains the infrastructure cache, as well as rate limiting. More...

#include "util/storage/lruhash.h"
#include "util/storage/dnstree.h"
#include "util/rtt.h"
#include "util/netevent.h"
#include "util/data/msgreply.h"

Data Structures
struct	infra_key
	Host information kept for every server, per zone. More...

struct	infra_data
	Host information encompasses host capabilities and retransmission timeouts. More...

struct	infra_cache
	Infra cache. More...

struct	domain_limit_data
	ratelimit settings for domains More...

struct	rate_key
	key for ratelimit lookups, a domain name More...

struct	ip_rate_key
	key for ip_ratelimit lookups, a source IP. More...

struct	rate_data
	Data for ratelimits per domain name It is incremented when a non-cache-lookup happens for that domain name. More...

Macros
#define	RATE_WINDOW 2
	number of seconds to track qps rate

#define	ip_rate_data rate_data

#define	INFRA_HOST_STARTSIZE 32
	infra host cache default hash lookup size

#define	INFRA_BYTES_NAME 14
	bytes per zonename reserved in the hostcache, dnamelen(zonename.com.)

#define	ip_rate_deldatafunc rate_deldatafunc

Functions
struct infra_cache *	infra_create (struct config_file *cfg)
	Create infra cache. More...

void	infra_delete (struct infra_cache *infra)
	Delete infra cache. More...

struct infra_cache *	infra_adjust (struct infra_cache infra, struct config_file cfg)
	Adjust infra cache to use updated configuration settings. More...

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)
	Plain find infra data function (used by the the other functions) More...

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)
	Find host information to send a packet. More...

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)
	Set a host to be lame for the given zone. More...

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 rtt information for the host. More...

void	infra_update_tcp_works (struct infra_cache infra, struct sockaddr_storage addr, socklen_t addrlen, uint8_t *name, size_t namelen)
	Update information for the host, store that a TCP transaction works. More...

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)
	Update edns information for the host. More...

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 Lameness information and average RTT if host is in the cache. More...

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 additional (debug) info on timing. More...

int	infra_ratelimit_inc (struct infra_cache infra, uint8_t name, size_t namelen, time_t timenow, int backoff, struct query_info qinfo, struct comm_reply replylist)
	Increment the query rate counter for a delegation point. More...

void	infra_ratelimit_dec (struct infra_cache infra, uint8_t name, size_t namelen, time_t timenow)
	Decrement the query rate counter for a delegation point. More...

int	infra_ratelimit_exceeded (struct infra_cache infra, uint8_t name, size_t namelen, time_t timenow, int backoff)
	See if the query rate counter for a delegation point is exceeded. More...

int	infra_rate_max (void *data, time_t now, int backoff)
	find the maximum rate stored. More...

int	infra_find_ratelimit (struct infra_cache infra, uint8_t name, size_t namelen)
	find the ratelimit in qps for a domain. More...

int	infra_ip_ratelimit_inc (struct infra_cache infra, struct sockaddr_storage addr, socklen_t addrlen, time_t timenow, int has_cookie, int backoff, struct sldns_buffer *buffer)
	Update query ratelimit hash and decide whether or not a query should be dropped. More...

size_t	infra_get_mem (struct infra_cache *infra)
	Get memory used by the infra cache. More...

size_t	infra_sizefunc (void k, void d)
	calculate size for the hashtable, does not count size of lameness, so the hashtable is a fixed number of items

int	infra_compfunc (void key1, void key2)
	compare two addresses, returns -1, 0, or +1

void	infra_delkeyfunc (void k, void arg)
	delete key, and destroy the lock

void	infra_deldatafunc (void d, void arg)
	delete data and destroy the lameness hashtable

size_t	rate_sizefunc (void k, void d)
	calculate size for the hashtable

int	rate_compfunc (void key1, void key2)
	compare two names, returns -1, 0, or +1

void	rate_delkeyfunc (void k, void arg)
	delete key, and destroy the lock

void	rate_deldatafunc (void d, void arg)
	delete data

size_t	ip_rate_sizefunc (void k, void d)

int	ip_rate_compfunc (void key1, void key2)

void	ip_rate_delkeyfunc (void d, void arg)

Variables
int	infra_dp_ratelimit
	ratelimit, unless overridden by domain_limits, 0 is off More...

int	infra_ip_ratelimit
	ip ratelimit, 0 is off More...

int	infra_ip_ratelimit_cookie
	ip ratelimit for DNS Cookie clients, 0 is off More...

Detailed Description

This file contains the infrastructure cache, as well as rate limiting.

Note that there are two sorts of rate-limiting here:

Pre-cache, per-query rate limiting (query ratelimits)
Post-cache, per-domain name rate limiting (infra-ratelimits)

Function Documentation

◆ infra_create()

struct infra_cache* infra_create ( struct config_file * cfg )

Create infra cache.

Parameters

cfg	config parameters or NULL for defaults.

Returns: : new infra cache, or NULL.

References infra_cache::client_ip_rates, infra_cache::domain_rates, infra_cache::host_ttl, config_file::host_ttl, infra_cache::hosts, INFRA_BYTES_NAME, config_file::infra_cache_numhosts, config_file::infra_cache_slabs, infra_compfunc(), infra_deldatafunc(), infra_delete(), infra_delkeyfunc(), infra_dp_ratelimit, INFRA_HOST_STARTSIZE, infra_ip_ratelimit, infra_cache::infra_keep_probing, config_file::infra_keep_probing, infra_sizefunc(), config_file::ip_ratelimit, config_file::ip_ratelimit_size, config_file::ip_ratelimit_slabs, rate_compfunc(), rate_deldatafunc(), rate_delkeyfunc(), rate_sizefunc(), config_file::ratelimit, config_file::ratelimit_size, config_file::ratelimit_slabs, setup_domain_limits(), and slabhash_create().

Referenced by infra_adjust().

◆ infra_delete()

void infra_delete ( struct infra_cache * infra )

Delete infra cache.

Parameters

infra infrastructure cache to delete.

References infra_cache::client_ip_rates, domain_limit_free(), infra_cache::domain_limits, infra_cache::domain_rates, infra_cache::hosts, slabhash_delete(), and traverse_postorder().

Referenced by daemon_delete(), infra_adjust(), and infra_create().

◆ infra_adjust()

struct infra_cache* infra_adjust	(	struct infra_cache *	infra,
		struct config_file *	cfg
	)

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.

Parameters

infra	existing cache. If NULL a new infra cache is returned.
cfg	config options.

Returns: the new infra cache pointer or NULL on error.

References infra_cache::client_ip_rates, domain_limit_free(), infra_cache::domain_limits, infra_cache::domain_rates, infra_cache::host_ttl, config_file::host_ttl, infra_cache::hosts, INFRA_BYTES_NAME, config_file::infra_cache_numhosts, config_file::infra_cache_slabs, infra_create(), infra_delete(), infra_dp_ratelimit, infra_ip_ratelimit, infra_cache::infra_keep_probing, config_file::infra_keep_probing, config_file::ip_ratelimit, config_file::ip_ratelimit_size, config_file::ip_ratelimit_slabs, config_file::ratelimit, config_file::ratelimit_size, config_file::ratelimit_slabs, setup_domain_limits(), slabhash_is_size(), and traverse_postorder().

Referenced by context_finalize().

◆ infra_lookup_nottl()

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
	)

Plain find infra data function (used by the the other functions)

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	domain name of zone.
namelen	length of domain name.
wr	if true, writelock, else readlock.

Returns: the entry, could be expired (this is not checked) or NULL.

Plain find infra data function (used by the the other functions)

References infra_key::addr, infra_key::addrlen, lruhash_entry::data, infra_key::entry, lruhash_entry::hash, hash_infra(), infra_cache::hosts, lruhash_entry::key, infra_key::namelen, slabhash_lookup(), and infra_key::zonename.

Referenced by infra_edns_update(), infra_get_host_rto(), infra_get_lame_rtt(), infra_host(), infra_rtt_update(), infra_set_lame(), and infra_update_tcp_works().

◆ infra_host()

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
	)

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.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	domain name of zone.
namelen	length of domain name.
timenow	what time it is now.
edns_vs	edns version it supports, is returned.
edns_lame_known	if EDNS lame (EDNS is dropped in transit) has already been probed, is returned.
to	timeout to use, is returned.

Returns: : 0 on error.

References lruhash_entry::data, data_entry_init(), infra_data::edns_lame_known, infra_data::edns_version, lruhash_entry::hash, infra_cache::hosts, infra_cache::infra_keep_probing, infra_lookup_nottl(), lruhash_entry::lock, new_entry(), PROBE_MAXRTO, infra_data::probedelay, rtt_info::rto, infra_data::rtt, rtt_notimeout(), rtt_timeout(), slabhash_insert(), and USEFUL_SERVER_TOP_TIMEOUT.

Referenced by expon_timeout_backoff(), print_dp_details(), serviced_tcp_send(), and serviced_udp_send().

◆ infra_set_lame()

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
	)

Set a host to be lame for the given zone.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	domain name of zone apex.
namelen	length of domain name.
timenow	what time it is now.
dnsseclame	if true the host is set dnssec lame. if false, the host is marked lame (not serving the zone).
reclame	if true host is a recursor not AA server. if false, dnsseclame or marked lame.
qtype	the query type for which it is lame.

Returns: : 0 on error.

References lruhash_entry::data, data_entry_init(), lruhash_entry::hash, infra_cache::hosts, infra_lookup_nottl(), infra_data::isdnsseclame, infra_data::lame_other, infra_data::lame_type_A, LDNS_RR_TYPE_A, lruhash_entry::lock, log_err(), new_entry(), infra_data::rec_lame, and slabhash_insert().

◆ infra_rtt_update()

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 rtt information for the host.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	zone name
namelen	zone name length
qtype	query type.
roundtrip	estimate of roundtrip time in milliseconds or -1 for timeout.
orig_rtt	original rtt for the query that timed out (roundtrip==-1). ignored if roundtrip != -1.
timenow	what time it is now.

Returns: : 0 on error. new rto otherwise.

References lruhash_entry::data, data_entry_init(), lruhash_entry::hash, infra_cache::hosts, infra_lookup_nottl(), LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, lruhash_entry::lock, new_entry(), infra_data::probedelay, rtt_info::rto, infra_data::rtt, rtt_init(), rtt_lost(), rtt_unclamped(), rtt_update(), slabhash_insert(), infra_data::timeout_A, infra_data::timeout_AAAA, TIMEOUT_COUNT_MAX, infra_data::timeout_other, and USEFUL_SERVER_TOP_TIMEOUT.

Referenced by expon_timeout_backoff().

◆ infra_update_tcp_works()

void infra_update_tcp_works	(	struct infra_cache *	infra,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		uint8_t *	name,
		size_t	namelen
	)

Update information for the host, store that a TCP transaction works.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	name of zone
namelen	length of name

References lruhash_entry::data, infra_lookup_nottl(), lruhash_entry::lock, rtt_info::rto, infra_data::rtt, and RTT_MAX_TIMEOUT.

Referenced by serviced_tcp_callback().

◆ infra_edns_update()

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
	)

Update edns information for the host.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	name of zone
namelen	length of name
edns_version	the version that it publishes. If it is known to support EDNS then no-EDNS is not stored over it.
timenow	what time it is now.

Returns: : 0 on error.

References lruhash_entry::data, data_entry_init(), infra_data::edns_lame_known, infra_data::edns_version, lruhash_entry::hash, infra_cache::hosts, infra_lookup_nottl(), lruhash_entry::lock, new_entry(), and slabhash_insert().

◆ infra_get_lame_rtt()

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 Lameness information and average RTT if host is in the cache.

This information is to be used for server selection.

Parameters

infra	infrastructure cache.
addr	host address.
addrlen	length of addr.
name	zone name.
namelen	zone name length.
qtype	the query to be made.
lame	if function returns true, this returns lameness of the zone.
dnsseclame	if function returns true, this returns if the zone is dnssec-lame.
reclame	if function returns true, this is if it is recursion lame.
rtt	if function returns true, this returns avg rtt of the server. The rtt value is unclamped and reflects recent timeouts.
timenow	what time it is now.

Returns: if found in cache, or false if not (or TTL bad).

References lruhash_entry::data, infra_cache::infra_keep_probing, infra_lookup_nottl(), infra_data::isdnsseclame, infra_data::lame_other, infra_data::lame_type_A, LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, lruhash_entry::lock, PROBE_MAXRTO, infra_data::probedelay, infra_data::rec_lame, rtt_info::rto, infra_data::rtt, rtt_notimeout(), rtt_unclamped(), infra_data::timeout_A, infra_data::timeout_AAAA, TIMEOUT_COUNT_MAX, infra_data::timeout_other, infra_data::ttl, and USEFUL_SERVER_TOP_TIMEOUT.

Referenced by iter_filter_unsuitable(), and print_dp_details().

◆ infra_get_host_rto()

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 additional (debug) info on timing.

Parameters

infra	infra cache.
addr	host address.
addrlen	length of addr.
name	zone name
namelen	zone name length
rtt	the rtt_info is copied into here (caller alloced return struct).
delay	probe delay (if any).
timenow	what time it is now.
tA	timeout counter on type A.
tAAAA	timeout counter on type AAAA.
tother	timeout counter on type other.

Returns: TTL the infra host element is valid for. If -1: not found in cache. TTL -2: found but expired.

References lruhash_entry::data, infra_lookup_nottl(), lruhash_entry::lock, infra_data::probedelay, infra_data::rtt, infra_data::timeout_A, infra_data::timeout_AAAA, infra_data::timeout_other, and infra_data::ttl.

Referenced by print_dp_details().

◆ infra_ratelimit_inc()

int infra_ratelimit_inc	(	struct infra_cache *	infra,
		uint8_t *	name,
		size_t	namelen,
		time_t	timenow,
		int	backoff,
		struct query_info *	qinfo,
		struct comm_reply *	replylist
	)

Increment the query rate counter for a delegation point.

Parameters

infra	infra cache.
name	zone name
namelen	zone name length
timenow	what time it is now.
backoff	if backoff is enabled.
qinfo	for logging, query name.
replylist	for logging, querier's address (if any).

Returns: 1 if it could be incremented. 0 if the increment overshot the ratelimit or if in the previous second the ratelimit was exceeded. Failures like alloc failures are not returned (probably as 1).

References addr_to_str(), dname_str(), infra_create_ratedata(), infra_dp_ratelimit, infra_find_ratedata(), infra_find_ratelimit(), infra_rate_give_second(), infra_rate_max(), query_info::qclass, query_info::qname, query_info::qtype, comm_reply::remote_addr, comm_reply::remote_addrlen, sldns_wire2str_class_buf(), sldns_wire2str_type_buf(), VERB_OPS, and verbose().

Referenced by outnet_serviced_query().

◆ infra_ratelimit_dec()

void infra_ratelimit_dec	(	struct infra_cache *	infra,
		uint8_t *	name,
		size_t	namelen,
		time_t	timenow
	)

Decrement the query rate counter for a delegation point.

Because the reply received for the delegation point was pleasant, we do not charge this delegation point with it (i.e. it was a referral). Should call it with same second as when inc() was called.

Parameters

infra	infra cache.
name	zone name
namelen	zone name length
timenow	what time it is now.

References infra_dp_ratelimit, infra_find_ratedata(), and infra_rate_get_second().

Referenced by outnet_serviced_query().

◆ infra_ratelimit_exceeded()

int infra_ratelimit_exceeded	(	struct infra_cache *	infra,
		uint8_t *	name,
		size_t	namelen,
		time_t	timenow,
		int	backoff
	)

See if the query rate counter for a delegation point is exceeded.

So, no queries are going to be allowed.

Parameters

infra	infra cache.
name	zone name
namelen	zone name length
timenow	what time it is now.
backoff	if backoff is enabled.

Returns: true if exceeded.

References infra_dp_ratelimit, infra_find_ratedata(), infra_find_ratelimit(), and infra_rate_max().

◆ infra_rate_max()

int infra_rate_max	(	void *	data,
		time_t	now,
		int	backoff
	)

find the maximum rate stored.

0 if no information. When backoff is enabled look for the maximum in the whole RATE_WINDOW.

References rate_data::qps, RATE_WINDOW, and rate_data::timestamp.

Referenced by infra_ip_ratelimit_inc(), infra_ratelimit_exceeded(), infra_ratelimit_inc(), and rate_list().

◆ infra_find_ratelimit()

int infra_find_ratelimit	(	struct infra_cache *	infra,
		uint8_t *	name,
		size_t	namelen
	)

find the ratelimit in qps for a domain.

0 if no limit for domain.

References domain_limit_data::below, dname_count_labels(), infra_cache::domain_limits, infra_dp_ratelimit, name_tree_node::labs, LDNS_RR_CLASS_IN, domain_limit_data::lim, name_tree_lookup(), domain_limit_data::node, and name_tree_node::parent.

Referenced by infra_ratelimit_exceeded(), infra_ratelimit_inc(), and rate_list().

◆ infra_ip_ratelimit_inc()

int infra_ip_ratelimit_inc	(	struct infra_cache *	infra,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		time_t	timenow,
		int	has_cookie,
		int	backoff,
		struct sldns_buffer *	buffer
	)

Update query ratelimit hash and decide whether or not a query should be dropped.

Parameters

infra	infra cache
addr	client address
addrlen	client address length
timenow	what time it is now.
has_cookie	if the request came with a DNS Cookie.
backoff	if backoff is enabled.
buffer	with query for logging.

Returns: 1 if it could be incremented. 0 if the increment overshot the ratelimit and the query should be dropped.

References infra_find_ip_ratedata(), infra_ip_ratelimit, infra_rate_give_second(), and infra_rate_max().

◆ infra_get_mem()

size_t infra_get_mem ( struct infra_cache * infra )

Get memory used by the infra cache.

Parameters

infra infrastructure cache.

Returns: memory in use in bytes.

References infra_cache::client_ip_rates, infra_cache::domain_rates, infra_cache::hosts, and slabhash_get_mem().

Variable Documentation

◆ infra_dp_ratelimit

int infra_dp_ratelimit

extern

ratelimit, unless overridden by domain_limits, 0 is off

Referenced by config_set_option(), do_ratelimit_list(), infra_adjust(), infra_create(), infra_find_ratelimit(), infra_ratelimit_dec(), infra_ratelimit_exceeded(), and infra_ratelimit_inc().

◆ infra_ip_ratelimit

int infra_ip_ratelimit

extern

ip ratelimit, 0 is off

Referenced by config_set_option(), infra_adjust(), infra_create(), and infra_ip_ratelimit_inc().

◆ infra_ip_ratelimit_cookie

int infra_ip_ratelimit_cookie

extern

ip ratelimit for DNS Cookie clients, 0 is off

For clients with a valid DNS Cookie.

Referenced by config_set_option().

Data Structures

Macros

Functions

Variables

Detailed Description

Function Documentation

◆ infra_create()

◆ infra_delete()

◆ infra_adjust()

◆ infra_lookup_nottl()

◆ infra_host()

◆ infra_set_lame()

◆ infra_rtt_update()

◆ infra_update_tcp_works()

◆ infra_edns_update()

◆ infra_get_lame_rtt()

◆ infra_get_host_rto()

◆ infra_ratelimit_inc()

◆ infra_ratelimit_dec()

◆ infra_ratelimit_exceeded()

◆ infra_rate_max()

◆ infra_find_ratelimit()

◆ infra_ip_ratelimit_inc()

◆ infra_get_mem()

Variable Documentation

◆ infra_dp_ratelimit

◆ infra_ip_ratelimit

◆ infra_ip_ratelimit_cookie