libworker.c File Reference

This file contains the worker process or thread that performs the DNS resolving and validation. More...

#include "config.h"
#include "libunbound/libworker.h"
#include "libunbound/context.h"
#include "libunbound/unbound.h"
#include "services/outside_network.h"
#include "services/mesh.h"
#include "services/localzone.h"
#include "services/cache/rrset.h"
#include "services/outbound_list.h"
#include "util/module.h"
#include "util/regional.h"
#include "util/random.h"
#include "util/config_file.h"
#include "util/netevent.h"
#include "util/storage/slabhash.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "util/data/msgreply.h"
#include "util/data/msgencode.h"

Functions
static void	handle_newq (struct libworker *w, uint8_t *buf, uint32_t len)
	handle new query command for bg worker
static void	libworker_delete (struct libworker *w)
	delete libworker struct
static struct libworker *	libworker_setup (struct ub_ctx *ctx, int is_bg)
	setup fresh libworker struct
static void	handle_cancel (struct libworker *w, uint8_t *buf, uint32_t len)
	handle cancel command for bg worker
static void	libworker_do_cmd (struct libworker *w, uint8_t *msg, uint32_t len)
	do control command coming into bg server
int	libworker_handle_control_cmd (struct comm_point *c, void *arg, int err, struct comm_reply *rep)
	handle control command coming into server
int	libworker_handle_result_write (struct comm_point *c, void *arg, int err, struct comm_reply *rep)
	handle opportunity to write result back
static void *	libworker_dobg (void *arg)
	the background thread func
int	libworker_bg (struct ub_ctx *ctx)
	Create a background worker.
static struct reply_info *	parse_reply (ldns_buffer *pkt, struct regional *region, struct query_info *qi)
	get msg reply struct (in temp region)
static int	fill_canon (struct ub_result *res, uint8_t *s)
	insert canonname
static int	fill_res (struct ub_result *res, struct ub_packed_rrset_key *answer, uint8_t *finalcname, struct query_info *rq)
	fill data into result
void	libworker_enter_result (struct ub_result *res, ldns_buffer *buf, struct regional *temp, enum sec_status msg_security)
	fill result from parsed message, on error fills servfail
static void	libworker_fillup_fg (struct ctx_query *q, int rcode, ldns_buffer *buf, enum sec_status s)
	fillup fg results
static void	libworker_fg_done_cb (void *arg, int rcode, ldns_buffer *buf, enum sec_status s)
	callback with fg results
static int	setup_qinfo_edns (struct libworker *w, struct ctx_query *q, struct query_info *qinfo, struct edns_data *edns)
	setup qinfo and edns
int	libworker_fg (struct ub_ctx *ctx, struct ctx_query *q)
	Create a foreground worker.
static void	add_bg_result (struct libworker *w, struct ctx_query *q, ldns_buffer *pkt, int err)
	add result to the bg worker result queue
static void	libworker_bg_done_cb (void *arg, int rcode, ldns_buffer *buf, enum sec_status s)
	callback with bg results
void	libworker_alloc_cleanup (void *arg)
	cleanup the cache to remove all rrset IDs from it, arg is libworker
int	libworker_send_packet (ldns_buffer *pkt, struct sockaddr_storage *addr, socklen_t addrlen, int timeout, struct module_qstate *q, int use_tcp)
	Worker service routine to send udp messages for modules.
static int	outbound_entry_compare (void *a, void *b)
	compare outbound entry qstates
struct outbound_entry *	libworker_send_query (uint8_t *qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, uint16_t flags, int dnssec, struct sockaddr_storage *addr, socklen_t addrlen, struct module_qstate *q)
	Worker service routine to send serviced queries to authoritative servers.
int	libworker_handle_reply (struct comm_point *c, void *arg, int error, struct comm_reply *reply_info)
	process incoming replies from the network
int	libworker_handle_service_reply (struct comm_point *c, void *arg, int error, struct comm_reply *reply_info)
	process incoming serviced query replies from the network
int	libworker_write_msg (int fd, uint8_t *buf, uint32_t len, int nonblock)
	Write length bytes followed by message.
int	libworker_read_msg (int fd, uint8_t **buf, uint32_t *len, int nonblock)
	Read length bytes followed by message.
int	worker_handle_control_cmd (struct comm_point *c, void *arg, int error, struct comm_reply *reply_info)
	process control messages from the main thread.
int	worker_handle_request (struct comm_point *c, void *arg, int error, struct comm_reply *repinfo)
	handles callbacks from listening event interface
int	worker_handle_reply (struct comm_point *c, void *arg, int error, struct comm_reply *reply_info)
	process incoming replies from the network
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
void	worker_sighandler (int sig, void *arg)
	Worker signal handler function.
int	worker_send_packet (ldns_buffer *pkt, struct sockaddr_storage *addr, socklen_t addrlen, int timeout, struct module_qstate *q, int use_tcp)
	Worker service routine to send udp messages for modules.
struct outbound_entry *	worker_send_query (uint8_t *qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, uint16_t flags, int dnssec, struct sockaddr_storage *addr, socklen_t addrlen, struct module_qstate *q)
	Worker service routine to send serviced queries to authoritative servers.
void	worker_alloc_cleanup (void *arg)
	cleanup the cache to remove all rrset IDs from it, arg is worker
int	acl_list_cmp (const void *k1, const void *k2)
	compare two acl list entries
void	worker_stat_timer_cb (void *arg)
	statistics timer callback handler
int	order_lock_cmp (const void *e1, const void *e2)
	Due to module breakage by fptr wlist, these test app declarations are presented here.
int	codeline_cmp (const void *a, const void *b)
	compare two codeline structs for rbtree from memstats test app

---

Detailed Description

This file contains the worker process or thread that performs the DNS resolving and validation.

The worker is called by a procedure and if in the background continues until exit, if in the foreground returns from the procedure when done.

---

Function Documentation

int libworker_bg

(

struct ub_ctx *

ctx

)

Create a background worker.

Parameters:

ctx,:

is updated with pid/tid of the background worker. a new allocation cache is obtained from ctx. It contains the threadnumber and unique id for further (shared) cache insertions.

Returns:

0 if OK, else error. Further communication is done via the pipes in ctx.

References ub_ctx::bg_pid, ub_ctx::bg_tid, ub_ctx::cfglock, ub_ctx::dothread, fatal_exit(), libworker::is_bg_thread, libworker_dobg(), libworker_setup(), ub_ctx::qqpipe, ub_ctx::rrpipe, libworker::thread_num, UB_FORKFAIL, UB_NOERROR, and UB_NOMEM.

Referenced by ub_resolve_async().

void libworker_enter_result	(	struct ub_result *	res,
		ldns_buffer *	buf,
		struct regional *	temp,
		enum sec_status	msg_security
	)

fill result from parsed message, on error fills servfail

Parameters:

	res,:	is clear at start, filled in at end.
	buf,:	contains DNS message.
	temp,:	temporary buffer for parse.
	msg_security,:	security status of the DNS message. On error, the res may contain a different status (out of memory is not secure, not bogus).

References ub_result::bogus, ub_result::data, fill_res(), reply_info::flags, FLAGS_GET_RCODE, ub_result::havedata, log_err(), ub_result::nxdomain, parse_reply(), ub_result::rcode, reply_find_answer_rrset(), reply_find_final_cname_target(), sec_status_bogus, sec_status_secure, and ub_result::secure.

Referenced by libworker_fillup_fg(), and process_answer_detail().

int libworker_fg	(	struct ub_ctx *	ctx,
		struct ctx_query *	q
	)

Create a foreground worker.

This worker will join the threadpool of resolver threads. It exits when the query answer has been obtained (or error). This routine blocks until the worker is finished.

Parameters:

	ctx,:	new allocation cache obtained and returned to it.
	q,:	query (result is stored in here).

Returns:

0 if finished OK, else error.

References libworker::back, libworker::base, BIT_RD, comm_base_dispatch(), libworker::env, libworker_delete(), libworker_fg_done_cb(), libworker_fillup_fg(), libworker_setup(), ub_ctx::local_zones, local_zones_answer(), module_env::mesh, mesh_new_callback(), query_info::qname, module_env::scratch, sec_status_insecure, setup_qinfo_edns(), UB_INITFAIL, UB_NOERROR, UB_NOMEM, UB_SYNTAX, outside_network::udp_buff, and ctx_query::w.

Referenced by ub_resolve().

int libworker_send_packet	(	ldns_buffer *	pkt,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		int	timeout,
		struct module_qstate *	q,
		int	use_tcp
	)

Worker service routine to send udp messages for modules.

Parameters:

	pkt,:	packet to send.
	addr,:	where to.
	addrlen,:	length of addr.
	timeout,:	seconds to wait until timeout.
	q,:	wich query state to reactivate upon return.
	use_tcp,:	true to use TCP, false for UDP.

Returns:

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

References libworker::back, module_qstate::env, libworker_handle_reply(), pending_tcp_query(), pending_udp_query(), and module_env::worker.

struct outbound_entry* libworker_send_query	(	uint8_t *	qname,
		size_t	qnamelen,
		uint16_t	qtype,
		uint16_t	qclass,
		uint16_t	flags,
		int	dnssec,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		struct module_qstate *	q
	)			[read]

Worker service routine to send serviced queries to authoritative servers.

Parameters:

	qname,:	query name. (host order)
	qnamelen,:	length in bytes of qname, including trailing 0.
	qtype,:	query type. (host order)
	qclass,:	query class. (host order)
	flags,:	host order flags word, with opcode and CD bit.
	dnssec,:	if set, EDNS record will have DO bit set.
	addr,:	where to.
	addrlen,:	length of addr.
	q,:	wich query state to reactivate upon return.

Returns:

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

References libworker::back, module_qstate::env, libworker_handle_service_reply(), outbound_entry_compare(), outnet_serviced_query(), module_qstate::region, regional_alloc(), outside_network::udp_buff, and module_env::worker.

int libworker_write_msg	(	int	fd,
		uint8_t *	buf,
		uint32_t	len,
		int	nonblock
	)

Write length bytes followed by message.

Parameters:

	fd,:	the socket to write on. Is nonblocking. Set to blocking by the function, and back to non-blocking at exit of function.
	buf,:	the message.
	len,:	length of message.
	nonblock,:	if set to true, the first write is nonblocking. If the first write fails the function returns -1. If set false, the first write is blocking.

Returns:

: all remainder writes are nonblocking. return 0 on error, in that case blocking/nonblocking of socket is unknown. return 1 if all OK.

References fd_set_block(), fd_set_nonblock(), and log_err().

Referenced by libworker_dobg(), ub_cancel(), ub_ctx_delete(), and ub_resolve_async().

int libworker_read_msg	(	int	fd,
		uint8_t **	buf,
		uint32_t *	len,
		int	nonblock
	)

Read length bytes followed by message.

Parameters:

	fd,:	the socket to write on. Is nonblocking. Set to blocking by the function, and back to non-blocking at exit of function.
	buf,:	the message, malloced.
	len,:	length of message, returned.
	nonblock,:	if set to true, the first read is nonblocking. If the first read fails the function returns -1. If set false, the first read is blocking.

Returns:

: all remainder reads are nonblocking. return 0 on error, in that case blocking/nonblocking of socket is unknown. On EOF 0 is returned. return 1 if all OK.

References fd_set_block(), fd_set_nonblock(), and log_err().

Referenced by ub_ctx_delete(), ub_process(), and ub_wait().

int worker_handle_control_cmd	(	struct comm_point *	c,
		void *	arg,
		int	error,
		struct comm_reply *	reply_info
	)

process control messages from the main thread.

Parameters:

	c,:	comm point to read from.
	arg,:	worker.
	error,:	error status of comm point.
	reply_info,:	not used.

References log_assert.

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 log_assert.

int worker_send_packet	(	ldns_buffer *	pkt,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		int	timeout,
		struct module_qstate *	q,
		int	use_tcp
	)

Worker service routine to send udp messages for modules.

Parameters:

	pkt,:	packet to send.
	addr,:	where to.
	addrlen,:	length of addr.
	timeout,:	seconds to wait until timeout.
	q,:	wich query state to reactivate upon return.
	use_tcp,:	true to use TCP, false for UDP.

Returns:

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

References log_assert.

struct outbound_entry* worker_send_query	(	uint8_t *	qname,
		size_t	qnamelen,
		uint16_t	qtype,
		uint16_t	qclass,
		uint16_t	flags,
		int	dnssec,
		struct sockaddr_storage *	addr,
		socklen_t	addrlen,
		struct module_qstate *	q
	)			[read]

Worker service routine to send serviced queries to authoritative servers.

Parameters:

	qname,:	query name. (host order)
	qnamelen,:	length in bytes of qname, including trailing 0.
	qtype,:	query type. (host order)
	qclass,:	query class. (host order)
	flags,:	host order flags word, with opcode and CD bit.
	dnssec,:	if set, EDNS record will have DO bit set.
	addr,:	where to.
	addrlen,:	length of addr.
	q,:	wich query state to reactivate upon return.

Returns:

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

References log_assert.

int order_lock_cmp	(	const void *	e1,
		const void *	e2
	)

Due to module breakage by fptr wlist, these test app declarations are presented here.

compare two order_ids from lock-verify test app

Parameters:

	e1,:	first order_id
	e2,:	second order_id

Returns:

compare code -1, 0, +1 (like memcmp).

References log_assert.

int codeline_cmp	(	const void *	a,
		const void *	b
	)

compare two codeline structs for rbtree from memstats test app

Parameters:

	a,:	codeline
	b,:	codeline

Returns:

compare code -1, 0, +1 (like memcmp).

References log_assert.