dtstream.h File Reference

An implementation of the Frame Streams data transport protocol for the Unbound DNSTAP message logging facility. More...

#include "util/locks.h"

Data Structures
struct	dt_msg_queue
	A message buffer with dnstap messages queued up. More...
struct	dt_msg_entry
	An entry in the dt_msg_queue. More...
struct	dt_frame_read_buf
	Containing buffer and counter for reading DNSTAP frames. More...
struct	dt_io_thread
	IO thread that reads from the queues and writes them. More...
struct	dt_io_list_item
	IO thread list of queues list item lists a worker queue that should be looked at and sent to the log server. More...

Functions
struct dt_msg_queue *	dt_msg_queue_create (struct comm_base *base)
	Create new (empty) worker message queue. More...
void	dt_msg_queue_delete (struct dt_msg_queue *mq)
	Delete a worker message queue. More...
void	dt_msg_queue_submit (struct dt_msg_queue *mq, void *buf, size_t len)
	Submit a message to the queue. More...
void	mq_wakeup_cb (void *arg)
	timer callback to wakeup dtio thread to process messages
struct dt_io_thread *	dt_io_thread_create (void)
	Create IO thread. More...
void	dt_io_thread_delete (struct dt_io_thread *dtio)
	Delete the IO thread structure. More...
int	dt_io_thread_apply_cfg (struct dt_io_thread *dtio, struct config_file *cfg)
	Apply config to the dtio thread. More...
int	dt_io_thread_register_queue (struct dt_io_thread *dtio, struct dt_msg_queue *mq)
	Register a msg queue to the io thread. More...
void	dt_io_thread_unregister_queue (struct dt_io_thread *dtio, struct dt_msg_queue *mq)
	Unregister queue from io thread. More...
int	dt_io_thread_start (struct dt_io_thread *dtio, void *event_base_nothr, int numworkers)
	Start the io thread. More...
void	dt_io_thread_stop (struct dt_io_thread *dtio)
	Stop the io thread. More...
void	dtio_reconnect_timeout_cb (int fd, short bits, void *arg)
	callback for the dnstap reconnect, to start reconnecting to output
void	dtio_output_cb (int fd, short bits, void *arg)
	callback for the dnstap events, to write to the output
void	dtio_cmd_cb (int fd, short bits, void *arg)
	callback for the dnstap commandpipe, to stop the dnstap IO
void	dtio_stop_timer_cb (int fd, short bits, void *arg)
	callback for the timer when the thread stops and wants to finish up
void	dtio_stop_ev_cb (int fd, short bits, void *arg)
	callback for the output when the thread stops and wants to finish up
void	dtio_tap_callback (int fd, short bits, void *arg)
	callback for unbound-dnstap-socket
void	dtio_mainfdcallback (int fd, short bits, void *arg)
	callback for unbound-dnstap-socket

Detailed Description

An implementation of the Frame Streams data transport protocol for the Unbound DNSTAP message logging facility.

Function Documentation

dt_msg_queue_create()

struct dt_msg_queue* dt_msg_queue_create

(

struct comm_base *

base

)

Create new (empty) worker message queue.

Limit set to default on max.

Parameters

base	event base for wakeup timer.

Returns

NULL on malloc failure or a new queue (not locked).

References comm_timer_create(), dt_msg_queue::lock, dt_msg_queue::maxsize, mq_wakeup_cb(), and dt_msg_queue::wakeup_timer.

dt_msg_queue_delete()

void dt_msg_queue_delete

(

struct dt_msg_queue *

mq

)

Delete a worker message queue.

It has to be unlinked from access, so it can be deleted without lock worries. The queue is emptied (deleted).

Parameters

mq	message queue.

References comm_timer_delete(), dt_msg_queue_clear(), dt_msg_queue::lock, and dt_msg_queue::wakeup_timer.

dt_msg_queue_submit()

void dt_msg_queue_submit	(	struct dt_msg_queue *	mq,
		void *	buf,
		size_t	len
	)

Submit a message to the queue.

The queue is locked by the routine, the message is inserted, and then the queue is unlocked so the message can be picked up by the writer thread.

Parameters

mq	message queue.
buf	buffer with message (dnstap contents). The buffer must have been malloced by caller. It is linked in the queue, and is free()d after use. If the routine fails the buffer is freed as well (and nothing happens, the item could not be logged).
len	length of buffer.

References dt_msg_entry::buf, dt_msg_queue::cursize, dt_msg_queue_start_timer(), DTIO_MSG_FOR_WAKEUP, dt_msg_queue::first, dt_msg_entry::len, dt_msg_queue::lock, log_err(), dt_msg_queue::maxsize, dt_msg_queue::msgcount, dt_msg_entry::next, and entry::next.

dt_io_thread_create()

struct dt_io_thread* dt_io_thread_create

(

void

)

Create IO thread.

Returns

new io thread object. not yet started. or NULL malloc failure.

References dt_io_thread::wakeup_timer_enabled, and dt_io_thread::wakeup_timer_lock.

dt_io_thread_delete()

void dt_io_thread_delete

(

struct dt_io_thread *

dtio

)

Delete the IO thread structure.

Parameters

dtio	the io thread that is deleted. It must not be running.

References dt_io_thread::client_cert_file, dt_io_thread::client_key_file, dt_io_thread::io_list, dt_io_thread::ip_str, dt_io_list_item::next, dt_io_thread::socket_path, dt_io_thread::ssl_ctx, dt_io_thread::tls_server_name, and dt_io_thread::wakeup_timer_lock.

dt_io_thread_apply_cfg()

int dt_io_thread_apply_cfg	(	struct dt_io_thread *	dtio,
		struct config_file *	cfg
	)

Apply config to the dtio thread.

Parameters

dtio	io thread, not yet started.
cfg	config file struct.

Returns

false on malloc failure.

References check_auth_name_for_ssl(), config_file::chrootdir, dt_io_thread::client_cert_file, dt_io_thread::client_key_file, connect_sslctx_create(), config_file::dnstap, config_file::dnstap_bidirectional, config_file::dnstap_ip, config_file::dnstap_socket_path, config_file::dnstap_tls, config_file::dnstap_tls_cert_bundle, config_file::dnstap_tls_client_cert_file, config_file::dnstap_tls_client_key_file, config_file::dnstap_tls_server_name, dt_io_thread::ip_str, dt_io_thread::is_bidirectional, log_err(), log_warn(), dt_io_thread::socket_path, dt_io_thread::ssl_ctx, config_file::tls_cert_bundle, dt_io_thread::tls_server_name, dt_io_thread::tls_use_sni, config_file::tls_use_sni, config_file::tls_win_cert, dt_io_thread::upstream_is_tcp, dt_io_thread::upstream_is_tls, dt_io_thread::upstream_is_unix, and dt_io_thread::use_client_certs.

dt_io_thread_register_queue()

int dt_io_thread_register_queue	(	struct dt_io_thread *	dtio,
		struct dt_msg_queue *	mq
	)

Register a msg queue to the io thread.

It will be polled to see if there are messages and those then get removed and sent, when the thread is running.

Parameters

dtio	the io thread.
mq	message queue to register.

Returns

false on failure (malloc failure).

References dt_msg_queue::dtio, dt_io_thread::io_list, dt_io_thread::io_list_iter, dt_msg_queue::lock, dt_io_list_item::next, and dt_io_list_item::queue.

dt_io_thread_unregister_queue()

void dt_io_thread_unregister_queue	(	struct dt_io_thread *	dtio,
		struct dt_msg_queue *	mq
	)

Unregister queue from io thread.

Parameters

dtio	the io thread.
mq	message queue.

References dt_msg_queue::dtio, dt_io_thread::io_list, dt_io_thread::io_list_iter, dt_msg_queue::lock, dt_io_list_item::next, and dt_io_list_item::queue.

dt_io_thread_start()

int dt_io_thread_start	(	struct dt_io_thread *	dtio,
		void *	event_base_nothr,
		int	numworkers
	)

Start the io thread.

Parameters

dtio	the io thread.
event_base_nothr	the event base to attach the events to, in case we are running without threads. With threads, this is ignored and a thread is started to process the dnstap log messages.
numworkers	number of worker threads. The dnstap io thread is that number +1 as the threadnumber (in logs).

Returns

false on failure.

References dt_io_thread::commandpipe, dnstap_io(), dtio_setup_on_base(), dt_io_thread::event_base, log_err(), dt_io_thread::started, dt_io_thread::threadnum, and dt_io_thread::tid.

dt_io_thread_stop()

void dt_io_thread_stop

(

struct dt_io_thread *

dtio

)

Stop the io thread.

Parameters

dtio	the io thread.

References dt_io_thread::commandpipe, DTIO_COMMAND_STOP, dtio_desetup(), log_err(), sock_strerror(), dt_io_thread::started, dt_io_thread::tid, VERB_ALGO, verbose(), and dt_io_thread::want_to_exit.

Referenced by worker_delete().