worker.c File Reference

This file implements the worker that handles callbacks on events, for pending requests. More...

#include "config.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/random.h"
#include "daemon/worker.h"
#include "daemon/daemon.h"
#include "daemon/remote.h"
#include "daemon/acl_list.h"
#include "util/netevent.h"
#include "util/config_file.h"
#include "util/module.h"
#include "util/regional.h"
#include "util/storage/slabhash.h"
#include "services/listen_dnsport.h"
#include "services/outside_network.h"
#include "services/outbound_list.h"
#include "services/cache/rrset.h"
#include "services/cache/infra.h"
#include "services/cache/dns.h"
#include "services/authzone.h"
#include "services/mesh.h"
#include "services/localzone.h"
#include "services/rpz.h"
#include "util/data/msgparse.h"
#include "util/data/msgencode.h"
#include "util/data/dname.h"
#include "util/fptr_wlist.h"
#include "util/proxy_protocol.h"
#include "util/tube.h"
#include "util/edns.h"
#include "util/timeval_func.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_hints.h"
#include "iterator/iter_utils.h"
#include "validator/autotrust.h"
#include "validator/val_anchor.h"
#include "respip/respip.h"
#include "libunbound/context.h"
#include "libunbound/libworker.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "util/shm_side/shm_main.h"
#include "dnscrypt/dnscrypt.h"
#include "dnstap/dtstream.h"
#include <signal.h>

Data Structures
struct	check_request_result
	Structure holding the result of the worker_check_request function. More...

Macros
#define	NORMAL_UDP_SIZE   512 /* bytes */
	Size of an UDP datagram.
#define	ERROR_RATELIMIT   100 /* qps */
	ratelimit for error responses
#define	PREFETCH_EXPIRY_ADD   60
	seconds to add to prefetch leeway. More...
#define	TA_RESPONSE_MAX_TXT   16 /* max number of TXT records */
#define	TA_RESPONSE_MAX_TAGS   32 /* max number of tags printed per zone */

Functions
static void	worker_mem_report (struct worker *ATTR_UNUSED(worker), struct serviced_query *ATTR_UNUSED(cur_serv))
	Report on memory usage by this thread and global.
void	worker_send_cmd (struct worker *worker, enum worker_commands cmd)
	Send a command to a worker. More...
int	worker_handle_service_reply (struct comm_point *c, void *arg, int error, struct comm_reply *reply_info)
	process incoming serviced query replies from the network
static int	worker_err_ratelimit (struct worker *worker, int err)
	ratelimit error replies More...
static void	worker_check_request (sldns_buffer *pkt, struct worker *worker, struct check_request_result *out)
	check request sanity. More...
void	worker_handle_control_cmd (struct tube *ATTR_UNUSED(tube), uint8_t *msg, size_t len, int error, void *arg)
static enum sec_status	check_delegation_secure (struct reply_info *rep)
	check if a delegation is secure
static void	deleg_remove_nonsecure_additional (struct reply_info *rep)
	remove nonsecure from a delegation referral additional section
static int	answer_norec_from_cache (struct worker *worker, struct query_info *qinfo, uint16_t id, uint16_t flags, struct comm_reply *repinfo, struct edns_data *edns)
	answer nonrecursive query from the cache
static int	apply_respip_action (struct worker *worker, const struct query_info *qinfo, struct respip_client_info *cinfo, struct reply_info *rep, struct sockaddr_storage *addr, socklen_t addrlen, struct ub_packed_rrset_key **alias_rrset, struct reply_info **encode_repp, struct auth_zones *az)
	Apply, if applicable, a response IP action to a cached answer. More...
static int	answer_from_cache (struct worker *worker, struct query_info *qinfo, struct respip_client_info *cinfo, int *need_drop, int *is_expired_answer, int *is_secure_answer, struct ub_packed_rrset_key **alias_rrset, struct reply_info **partial_repp, struct reply_info *rep, uint16_t id, uint16_t flags, struct comm_reply *repinfo, struct edns_data *edns)
	answer query from the cache. More...
static void	reply_and_prefetch (struct worker *worker, struct query_info *qinfo, uint16_t flags, struct comm_reply *repinfo, time_t leeway, int noreply, int rpz_passthru, struct edns_option *opt_list)
	Reply to client and perform prefetch to keep cache up to date.
static void	chaos_replystr (sldns_buffer *pkt, char **str, int num, struct edns_data *edns, struct worker *worker, struct comm_reply *repinfo)
	Fill CH class answer into buffer. More...
static void	chaos_replyonestr (sldns_buffer *pkt, const char *str, struct edns_data *edns, struct worker *worker, struct comm_reply *repinfo)
	Reply with one string.
static void	chaos_trustanchor (sldns_buffer *pkt, struct edns_data *edns, struct worker *w, struct comm_reply *repinfo)
	Create CH class trustanchor answer. More...
static int	answer_chaos (struct worker *w, struct query_info *qinfo, struct edns_data *edns, struct comm_reply *repinfo, sldns_buffer *pkt)
	Answer CH class queries. More...
static void	answer_notify (struct worker *w, struct query_info *qinfo, struct edns_data *edns, sldns_buffer *pkt, struct sockaddr_storage *addr, socklen_t addrlen)
	Answer notify queries. More...
static int	deny_refuse (struct comm_point *c, enum acl_access acl, enum acl_access deny, enum acl_access refuse, struct worker *worker, struct comm_reply *repinfo, struct acl_addr *acladdr, int ede, struct check_request_result *check_result)
static int	deny_refuse_all (struct comm_point *c, enum acl_access *acl, struct worker *worker, struct comm_reply *repinfo, struct acl_addr **acladdr, int ede, int check_proxy, struct check_request_result *check_result)
static int	deny_refuse_non_local (struct comm_point *c, enum acl_access acl, struct worker *worker, struct comm_reply *repinfo, struct acl_addr *acladdr, int ede, struct check_request_result *check_result)
static int	check_ip_ratelimit (struct worker *worker, struct sockaddr_storage *addr, socklen_t addrlen, int has_cookie, sldns_buffer *pkt)
int	worker_handle_request (struct comm_point *c, void *arg, int error, struct comm_reply *repinfo)
	handles callbacks from listening event interface
void	worker_sighandler (int sig, void *arg)
	Worker signal handler function. More...
static void	worker_restart_timer (struct worker *worker)
	restart statistics timer for worker, if enabled
void	worker_stat_timer_cb (void *arg)
	statistics timer callback handler
void	worker_probe_timer_cb (void *arg)
	probe timer callback handler
struct worker *	worker_create (struct daemon *daemon, int id, int *ports, int n)
	Create the worker structure. More...
int	worker_init (struct worker *worker, struct config_file *cfg, struct listen_port *ports, int do_sigs)
	Initialize worker. More...
void	worker_work (struct worker *worker)
	Make worker work.
void	worker_delete (struct worker *worker)
	Delete worker.
struct outbound_entry *	worker_send_query (struct query_info *qinfo, uint16_t flags, int dnssec, int want_dnssec, int nocaps, int check_ratelimit, struct sockaddr_storage *addr, socklen_t addrlen, uint8_t *zone, size_t zonelen, int tcp_upstream, int ssl_upstream, char *tls_auth_name, struct module_qstate *q, int *was_ratelimited)
	Worker service routine to send serviced queries to authoritative servers. More...
void	worker_alloc_cleanup (void *arg)
	cleanup the cache to remove all rrset IDs from it, arg is worker
void	worker_stats_clear (struct worker *worker)
	Init worker stats - includes server_stats_init, outside network and mesh. More...
void	worker_start_accept (void *arg)
	start accept callback handler
void	worker_stop_accept (void *arg)
	stop accept callback handler
struct outbound_entry *	libworker_send_query (struct query_info *ATTR_UNUSED(qinfo), uint16_t ATTR_UNUSED(flags), int ATTR_UNUSED(dnssec), int ATTR_UNUSED(want_dnssec), int ATTR_UNUSED(nocaps), int ATTR_UNUSED(check_ratelimit), struct sockaddr_storage *ATTR_UNUSED(addr), socklen_t ATTR_UNUSED(addrlen), uint8_t *ATTR_UNUSED(zone), size_t ATTR_UNUSED(zonelen), int ATTR_UNUSED(tcp_upstream), int ATTR_UNUSED(ssl_upstream), char *ATTR_UNUSED(tls_auth_name), struct module_qstate *ATTR_UNUSED(q), int *ATTR_UNUSED(was_ratelimited))
int	libworker_handle_service_reply (struct comm_point *ATTR_UNUSED(c), void *ATTR_UNUSED(arg), int ATTR_UNUSED(error), struct comm_reply *ATTR_UNUSED(reply_info))
void	libworker_handle_control_cmd (struct tube *ATTR_UNUSED(tube), uint8_t *ATTR_UNUSED(buffer), size_t ATTR_UNUSED(len), int ATTR_UNUSED(error), void *ATTR_UNUSED(arg))
void	libworker_fg_done_cb (void *ATTR_UNUSED(arg), int ATTR_UNUSED(rcode), sldns_buffer *ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s), char *ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
void	libworker_bg_done_cb (void *ATTR_UNUSED(arg), int ATTR_UNUSED(rcode), sldns_buffer *ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s), char *ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
void	libworker_event_done_cb (void *ATTR_UNUSED(arg), int ATTR_UNUSED(rcode), sldns_buffer *ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s), char *ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
int	context_query_cmp (const void *ATTR_UNUSED(a), const void *ATTR_UNUSED(b))
int	order_lock_cmp (const void *ATTR_UNUSED(e1), const void *ATTR_UNUSED(e2))
int	codeline_cmp (const void *ATTR_UNUSED(a), const void *ATTR_UNUSED(b))

Detailed Description

This file implements the worker that handles callbacks on events, for pending requests.

Macro Definition Documentation

PREFETCH_EXPIRY_ADD

#define PREFETCH_EXPIRY_ADD   60

seconds to add to prefetch leeway.

This is a TTL that expires old rrsets earlier than they should in order to put the new update into the cache. This additional value is to make sure that if not all TTLs are equal in the message to be updated(and replaced), that rrsets with up to this much extra TTL are also replaced. This means that the resulting new message will have (most likely) this TTL at least, avoiding very small 'split second' TTLs due to operators choosing relative primes for TTLs (or so). Also has to be at least one to break ties (and overwrite cached entry).

Function Documentation

worker_send_cmd()

void worker_send_cmd	(	struct worker *	worker,
		enum worker_commands	cmd
	)

Send a command to a worker.

Uses blocking writes.

Parameters

worker	worker to send command to.
cmd	command to send.

References worker::cmd, log_err(), and tube_write_msg().

Referenced by daemon_stop_others(), distribute_cmd(), and server_stats_obtain().

worker_err_ratelimit()

static int worker_err_ratelimit ( struct worker *  worker, int  err  )

static

ratelimit error replies

Parameters

worker	the worker struct with ratelimit counter
err	error code that would be wanted.

Returns

value of err if okay, or -1 if it should be discarded instead.

References worker::env, worker::err_limit_count, worker::err_limit_time, ERROR_RATELIMIT, and module_env::now.

worker_check_request()

static void worker_check_request ( sldns_buffer *  pkt, struct worker *  worker, struct check_request_result *  out  )

static

check request sanity.

Parameters

pkt	the wire packet to examine for sanity.
worker	parameters for checking.
out	struct to update with the result.

References sldns_buffer_limit().

apply_respip_action()

static int apply_respip_action ( struct worker *  worker, const struct query_info *  qinfo, struct respip_client_info *  cinfo, struct reply_info *  rep, struct sockaddr_storage *  addr, socklen_t  addrlen, struct ub_packed_rrset_key **  alias_rrset, struct reply_info **  encode_repp, struct auth_zones *  az  )

static

Apply, if applicable, a response IP action to a cached answer.

If the answer is rewritten as a result of an action, '*encode_repp' will point to the reply info containing the modified answer. '*encode_repp' will be intact otherwise. It returns 1 on success, 0 otherwise.

References ub_server_stats::extended, LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, LDNS_RR_TYPE_ANY, query_info::local_alias, query_info::qclass, query_info::qname, query_info::qtype, respip_always_deny, respip_deny, respip_inform_deny, respip_inform_print(), respip_none, respip_rewrite_reply(), ub_server_stats::rpz_action, worker::scratchpad, and worker::stats.

Referenced by mesh_serve_expired_callback().

answer_from_cache()

static int answer_from_cache ( struct worker *  worker, struct query_info *  qinfo, struct respip_client_info *  cinfo, int *  need_drop, int *  is_expired_answer, int *  is_secure_answer, struct ub_packed_rrset_key **  alias_rrset, struct reply_info **  partial_repp, struct reply_info *  rep, uint16_t  id, uint16_t  flags, struct comm_reply *  repinfo, struct edns_data *  edns  )

static

answer query from the cache.

Normally, the answer message will be built in repinfo->c->buffer; if the answer is supposed to be suppressed or the answer is supposed to be an incomplete CNAME chain, the buffer is explicitly cleared to signal the caller as such. In the latter case *partial_rep will point to the incomplete reply, and this function is (possibly) supposed to be called again with that *partial_rep value to complete the chain. In addition, if the query should be completely dropped, '*need_drop' will be set to 1.

References BIT_CD, module_env::cfg, worker::env, reply_info::flags, FLAGS_GET_RCODE, config_file::ignore_cd, module_env::need_to_validate, module_env::now, config_file::serve_expired, config_file::serve_expired_client_timeout, config_file::serve_expired_ttl, reply_info::serve_expired_ttl, reply_info::ttl, and edns_data::udp_size.

chaos_replystr()

static void chaos_replystr ( sldns_buffer *  pkt, char **  str, int  num, struct edns_data *  edns, struct worker *  worker, struct comm_reply *  repinfo  )

static

Fill CH class answer into buffer.

Keeps query.

Parameters

pkt	buffer
str	string to put into text record (<255). array of strings, every string becomes a text record.
num	number of strings in array.
edns	edns reply information.
worker	worker with scratch region.
repinfo	reply information for a communication point.

chaos_trustanchor()

static void chaos_trustanchor ( sldns_buffer *  pkt, struct edns_data *  edns, struct worker *  w, struct comm_reply *  repinfo  )

static

Create CH class trustanchor answer.

Parameters

pkt	buffer
edns	edns reply information.
w	worker with scratch region.
repinfo	reply information for a communication point.

Referenced by answer_chaos().

answer_chaos()

static int answer_chaos ( struct worker *  w, struct query_info *  qinfo, struct edns_data *  edns, struct comm_reply *  repinfo, sldns_buffer *  pkt  )

static

Answer CH class queries.

Parameters

w	worker
qinfo	query info. Pointer into packet buffer.
edns	edns info from query.
repinfo	reply information for a communication point.
pkt	packet buffer.

Returns

: true if a reply is to be sent.

References module_env::cfg, chaos_replyonestr(), chaos_trustanchor(), worker::env, config_file::hide_identity, config_file::hide_trustanchor, config_file::hide_version, config_file::identity, LDNS_RR_TYPE_ANY, LDNS_RR_TYPE_TXT, log_err(), query_info::qname, query_info::qtype, query_dname_compare(), and config_file::version.

answer_notify()

static void answer_notify ( struct worker *  w, struct query_info *  qinfo, struct edns_data *  edns, sldns_buffer *  pkt, struct sockaddr_storage *  addr, socklen_t  addrlen  )

static

Answer notify queries.

These are notifies for authoritative zones, the reply is an ack that the notify has been received. We need to check access permission here.

Parameters

w	worker
qinfo	query info. Pointer into packet buffer.
edns	edns info from query.
addr	client address.
addrlen	client address length.
pkt	packet buffer.

worker_sighandler()

void worker_sighandler	(	int	sig,
		void *	arg
	)

Worker signal handler function.

User argument is the worker itself.

Parameters

sig	signal number.
arg	the worker (main worker) that handles signals.

References worker::base, comm_base_exit(), and worker::need_to_exit.

Referenced by fptr_whitelist_comm_signal(), and signal_handling_playback().

worker_create()

struct worker* worker_create	(	struct daemon *	daemon,
		int	id,
		int *	ports,
		int	n
	)

Create the worker structure.

Bare bones version, zeroed struct, with backpointers only. Use worker_init on it later.

Parameters

daemon	the daemon that this worker thread is part of.
id	the thread number from 0.. numthreads-1.
ports	the ports it is allowed to use, array.
n	the number of ports.

Returns

: the new worker or NULL on alloc failure.

References worker::cmd, worker::daemon, log_err(), memdup(), worker::numports, worker::ports, daemon::rand, worker::rndstate, worker::thread_num, tube_create(), tube_delete(), and ub_initstate().

worker_init()

int worker_init	(	struct worker *	worker,
		struct config_file *	cfg,
		struct listen_port *	ports,
		int	do_sigs
	)

Initialize worker.

Allocates event base, listens to ports

Parameters

worker	worker to initialize, created with worker_create.
cfg	configuration settings.
ports	list of shared query ports.
do_sigs	if true, worker installs signal handlers.

Returns

: false on error.

References worker::base, and worker::need_to_exit.

Referenced by thread_start().

worker_send_query()

struct outbound_entry* worker_send_query	(	struct query_info *	qinfo,
		uint16_t	flags,
		int	dnssec,
		int	want_dnssec,
		int	nocaps,
		int	check_ratelimit,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		uint8_t *	zone,
		size_t	zonelen,
		int	tcp_upstream,
		int	ssl_upstream,
		char *	tls_auth_name,
		struct module_qstate *	q,
		int *	was_ratelimited
	)

Worker service routine to send serviced queries to authoritative servers.

Parameters

qinfo	query info.
flags	host order flags word, with opcode and CD bit.
dnssec	if set, EDNS record will have DO bit set.
want_dnssec	signatures needed.
nocaps	ignore capsforid(if in config), do not perturb qname.
check_ratelimit	if set, will check ratelimit before sending out.
addr	where to.
addrlen	length of addr.
zone	wireformat dname of the zone.
zonelen	length of zone name.
tcp_upstream	use TCP for upstream queries.
ssl_upstream	use SSL for upstream queries.
tls_auth_name	if ssl_upstream, use this name with TLS authentication.
q	which query state to reactivate upon return.
was_ratelimited	it will signal back if the query failed to pass the ratelimit check.

Returns

: false on failure (memory or socket related). no query was sent.

References worker::back, module_qstate::env, outnet_serviced_query(), outbound_entry::qsent, outbound_entry::qstate, module_qstate::region, regional_alloc(), outside_network::udp_buff, module_env::worker, and worker_handle_service_reply().

Referenced by fptr_whitelist_modenv_send_query().

worker_stats_clear()

void worker_stats_clear

(

struct worker *

worker

)

Init worker stats - includes server_stats_init, outside network and mesh.

Parameters

worker

the worker to init

References worker::back, module_env::cfg, worker::env, module_env::mesh, mesh_stats_clear(), outside_network::num_tcp_outgoing, outside_network::num_udp_outgoing, server_stats_init(), worker::stats, and outside_network::unwanted_replies.

Referenced by do_flush_stats().